Energy Conservation Program: Test Procedures for Walk-In Coolers and Walk-In Freezers, 28780-28871 [2023-08128]
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DEPARTMENT OF ENERGY
10 CFR Parts 429 and 431
RIN 1904–AD78
Energy Conservation Program: Test
Procedures for Walk-In Coolers and
Walk-In Freezers
Office of Energy Efficiency and
Renewable Energy, Department of
Energy.
ACTION: Final rule.
AGENCY:
The U.S. Department of
Energy (DOE) is amending the test
procedures for walk-in coolers and
walk-in freezers to harmonize with
updated industry standards, revise
certain definitions, revise the test
methods to more accurately represent
field energy use, and to accommodate a
wider range of walk-in cooler and walkin freezer component equipment
designs.
DATES: The effective date of this rule is
June 5, 2023. The amendments will be
mandatory for product testing starting
October 31, 2023. Manufacturers will be
required to use the amended test
procedures until the compliance date of
any final rule establishing amended
energy conservation standards based on
the newly established test procedures.
At such time, manufacturers will be
required to begin using the newly
established test procedures.
The incorporation by reference of
certain materials listed in the rule is
approved by the Director of the Federal
Register on June 5, 2023. The
incorporation by reference of certain
other material listed in the rule was
approved by the Director of the Federal
Register on January 27, 2017.
ADDRESSES: The docket, which includes
Federal Register notices, public meeting
attendee lists and transcripts,
comments, and other supporting
documents/materials, is available for
review at www.regulations.gov. All
documents in the docket are listed in
the www.regulations.gov index.
However, not all documents listed in
the index may be publicly available,
such as those containing information
that is exempt from public disclosure.
A link to the docket web page can be
found at www.regulations.gov/docket/
EERE-2017-BT-TP-0010. The docket
web page contains instructions on how
to access all documents, including
public comments, in the docket.
For further information on how to
review the docket contact the Appliance
and Equipment Standards Program staff
at (202) 287–1445 or by email:
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SUMMARY:
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Ms.
Catherine Rivest, U.S. Department of
Energy, Office of Energy Efficiency and
Renewable Energy, Building
Technologies Office, EE–5B, 1000
Independence Avenue SW, Washington,
DC 20585–0121. Telephone: (202) 586–
7335. Email: ApplianceStandards
Questions@ee.doe.gov.
Mr. Matthew Schneider, U.S.
Department of Energy, Office of the
General Counsel, GC–33, 1000
Independence Avenue SW, Washington,
DC 20585–0121. Telephone: (240) 597–
6265. Email: matthew.schneider@
hq.doe.gov.
SUPPLEMENTARY INFORMATION: DOE
maintains a previously approved
incorporation by reference and
incorporates by reference the following
industry standards into part 431:
AHRI Standard 1250–2020, ‘‘2020
Standard for Performance Rating of
Walk-in Coolers and Freezers.’’
Copies of AHRI 1250–2020 can be
obtained from the Air-Conditioning,
Heating, and Refrigeration Institute,
2111 Wilson Blvd., Suite 400, Arlington,
VA 22201 or at www.ahrinet.org.
ANSI/ASHRAE 16–2016, ‘‘Method of
Testing for Rating Room Air
Conditioners, Packaged Terminal Air
Conditioners, and Packaged Terminal
Heat Pumps for Cooling and Heating
Capacity’’.
ANSI/ASHRAE 23.1–2010, ‘‘Methods
of Testing for Rating the Performance of
Positive Displacement Refrigerant
Compressors and Condensing Units that
Operate at Subcritical Temperatures of
the Refrigerant’’.
ANSI/ASHRAE 37–2009, ‘‘Methods of
Testing for Rating Electrically Driven
Unitary Air-Conditioning and HeatPump Equipment’’.
ANSI/ASHRAE 41.1–2013, ‘‘Standard
Method for Temperature Measurement’’.
ANSI/ASHRAE 41.3–2014, ‘‘Standard
Methods for Pressure Measurement’’.
ANSI/ASHRAE 41.6–2014, ‘‘Standard
Method for Humidity Measurement’’.
ANSI/ASHRAE 41.10–2013,
‘‘Standard Methods for Refrigerant Mass
Flow Measurement Using Flowmeters’’.
Copies of ANSI/ASHRAE 16–2016,
ANSI/ASHRAE 23.1–2010, ANSI/
ASHRAE 37–2009, ANSI/ASHRAE
41.1–2013, ANSI/ASHRAE 41.3–2014,
ANSI/ASHRAE 41.6–2014, and ANSI/
ASHRAE 41.10–2013, can be obtained
from the American Society of Heating,
Refrigerating and Air-Conditioning
Engineers, 180 Technology Parkway
NW, Peachtree Corners, GA 30092, or at
www.ashrae.org.
ASTM C518–17, ‘‘Standard Test
Method for Steady-State Thermal
FOR FURTHER INFORMATION CONTACT:
[EERE–2017–BT–TP–0010]
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Transmission Properties by Means of
the Heat Flow Meter Apparatus’’.
ASTM C1199–14, ‘‘Standard Test
Method for Measuring the Steady-State
Thermal Transmittance of Fenestration
Systems Using Hot Box Methods.’’
Copies of ASTM C518–17 and ASTM
C1199–14 can be obtained from ASTM
International, 100 Barr Harbor Drive,
P.O. Box C700, West Conshohocken, PA
19428–2959, or at www.astm.org.
NFRC 102–2020 [E0A0], ‘‘Procedure
for Measuring the Steady-State Thermal
Transmittance of Fenestration Systems’’
Copies of NFRC 102–2020 can be
obtained from the National Fenestration
Rating Council, 6305 Ivy Lane, Suite
140, Greenbelt, MD 20770, or at
www.nfrc.org.
See section IV.N of this document for
a further discussion of these standards.
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope and Definitions
1. Scope
2. Definitions
B. Updates to Industry Standards
1. Industry Standards for Determining
Thermal Transmittance (U-factor)
2. Industry Standard for Determining RValue
3. Industry Standards for Determining
AWEF
C. Amendments to Appendix A for Doors
1. Reference to NFRC 102–2020 in Place of
NFRC 100–2010 and Alternative
Efficiency Determination Methods for
Doors
2. Additional Definitions
3. Electrical Door Components
4. Percent Time Off Values
5. Energy Efficiency Ratio Values
6. Air Infiltration Reduction
D. Amendments to Appendix A for Display
Panels
E. Amendments to the Appendix B for
Panels and Non-Display Doors
1. 24-Hour Testing Window
2. Total Insulation and Test Specimen
Thickness
3. Parallelism and Flatness
4. Insulation Aging
5. Overall Thermal Transmittance of NonDisplay Panels
F. Amendments to Appendix C for
Refrigeration Systems
1. Refrigeration Test Room Conditioning
2. Temperature Measurement
Requirements
3. Hierarchy of Installation Instruction and
Specified Refrigerant Conditions for
Refrigerant Charging and Setting
Refrigerant Conditions
4. Subcooling Requirement for Mass Flow
Meters
5. Instrument Accuracy and Test
Tolerances
6. CO2 Unit Coolers
7. High-Temperature Unit Coolers
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G. Establishing Appendix C1 for
Refrigeration Systems
1. Off-Cycle Power Consumption
2. Single-Packaged Dedicated Systems
3. Detachable Single-Packaged Dedicated
Systems
4. Attached Split Systems
5. Systems for High-Temperature Freezer
Applications
6. Systems for High-Temperature
Applications
7. Variable-, Two-, and Multiple-Capacity
Systems
8. Defrost
9. Refrigerant Glide
10. Refrigerant Temperature and Pressure
Instrumentation Locations
11. Updates to Default Values for Unit
Cooler Parameters
12. Calculations and Rounding
H. Alternative Efficiency Determination
Methods for Refrigeration Systems
I. Sampling Plan for Enforcement Testing
J. Organizational Changes
K. Test Procedure Costs and Impact
1. Doors
2. Panels
3. Refrigeration Systems
L. Effective and Compliance Dates
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866
and 13563
B. Review Under the Regulatory Flexibility
Act
C. Review Under the Paperwork Reduction
Act of 1995
D. Review Under the National
Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates
Reform Act of 1995
H. Review Under the Treasury and General
Government Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General
Government Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal
Energy Administration Act of 1974
M. Congressional Notification
N. Description of Materials Incorporated by
Reference
V. Approval of the Office of the Secretary
I. Authority and Background
Walk-in coolers and walk-in freezers
(collectively ‘‘WICFs’’ or ‘‘walk-ins’’) are
included in the list of ‘‘covered
equipment’’ for which the U.S.
Department of Energy (DOE) is
authorized to establish and amend
energy conservation standards and test
procedures. (42 U.S.C. 6311(1)(G))
DOE’s energy conservation standards
and test procedures for WICFs are
currently prescribed at subpart R of part
431 of title 10 of the Code of Federal
Regulations (CFR). The following
sections discuss DOE’s authority to
establish test procedures for WICFs and
relevant background information
regarding DOE’s consideration of test
procedures for this equipment.
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A. Authority
The Energy Policy and Conservation
Act, Public Law 94–163, as amended
(‘‘EPCA’’),1 authorizes DOE to regulate
the energy efficiency of a number of
consumer products and certain
industrial equipment. (42 U.S.C. 6291–
6317) Title III, Part C of EPCA 2
established the Energy Conservation
Program for Certain Industrial
Equipment, which sets forth a variety of
provisions designed to improve energy
efficiency. This equipment includes
WICFs, the subject of this document. (42
U.S.C. 6311(1)(G))
The energy conservation program
under EPCA consists essentially of four
parts: (1) testing, (2) labeling, (3) Federal
energy conservation standards, and (4)
certification and enforcement
procedures. Relevant provisions of
EPCA include definitions (42 U.S.C.
6311), test procedures (42 U.S.C. 6314),
labeling provisions (42 U.S.C. 6315),
energy conservation standards (42
U.S.C. 6313), and the authority to
require information and reports from
manufacturers (42 U.S.C. 6316).
The Federal testing requirements
consist of test procedures that
manufacturers of covered equipment
must use as the basis for: (1) certifying
to DOE that their equipment complies
with the applicable energy conservation
standards adopted pursuant to EPCA (42
U.S.C. 6316(a); 42 U.S.C. 6295(s)), and
(2) making other representations about
the efficiency of that equipment (42
U.S.C. 6314(d)). Similarly, DOE must
use these test procedures to determine
whether the equipment complies with
relevant standards promulgated under
EPCA. (42 U.S.C. 6316(a); 42 U.S.C.
6295(s))
Federal energy efficiency
requirements for covered equipment
established under EPCA generally
supersede State laws and regulations
concerning energy conservation testing,
labeling, and standards. (42 U.S.C.
6316(a) and 42 U.S.C. 6316(b); 42 U.S.C.
6297) DOE may, however, grant waivers
of Federal preemption for particular
State laws or regulations, in accordance
with the procedures and other
provisions of EPCA. (42 U.S.C.
6316(b)(2)(D))
Under 42 U.S.C. 6314, EPCA sets forth
the criteria and procedures DOE must
follow when prescribing or amending
test procedures for covered equipment.
1 All references to EPCA in this document refer
to the statute as amended through the Energy Act
of 2020, Public Law 116–260 (Dec. 27, 2020), which
reflect the last statutory amendments that impact
Parts A and A–1 of EPCA.
2 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
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EPCA requires that any test procedures
prescribed or amended under this
section must be reasonably designed to
produce test results that reflect energy
efficiency, energy use, or estimated
annual operating cost of a given type of
covered equipment during a
representative average use cycle (as
determined by the Secretary) and
requires that test procedures not be
unduly burdensome to conduct. (42
U.S.C. 6314(a)(2))
EPCA also requires that, at least once
every 7 years, DOE evaluate test
procedures for each type of covered
equipment, including WICFs, to
determine whether amended test
procedures would more accurately or
fully comply with the requirements for
the test procedures to not be unduly
burdensome to conduct and be
reasonably designed to produce test
results that reflect energy efficiency,
energy use, and estimated operating
costs during a representative average
use cycle. (42 U.S.C. 6314(a)(1)) DOE
considers this rulemaking to be in
satisfaction of the 7-year review
requirement specified in EPCA.
In addition, if the Secretary
determines that a test procedure
amendment is warranted, the Secretary
must publish proposed test procedures
in the Federal Register, and afford
interested persons an opportunity (of
not less than 45 days duration) to
present oral and written data, views,
and arguments on the proposed test
procedures. (42 U.S.C. 6314(b)) If DOE
determines that test procedure revisions
are not appropriate, DOE must publish
its determination not to amend the test
procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
B. Background
For measuring walk-in energy use,
DOE has established separate test
procedures for the principal
components that may comprise a walkin (i.e., doors, panels, and refrigeration
systems), with separate test metrics for
each component. (10 CFR 431.304(b))
For walk-in doors and display panels,
the efficiency metric is daily energy
consumption, measured in kilowatthours per day (kWh/day), which
accounts for the thermal conduction
through the door or display panel and
the direct and indirect electricity use of
any electrical components associated
with the door. See 10 CFR
431.304(b)(1)–(2) and 10 CFR part 431,
subpart R, appendix A, ‘‘Uniform Test
Method for the Measurement of Energy
Consumption of the Components of
Envelopes of Walk-in Coolers and Walkin Freezers’’ (appendix A). The thermal
transmittance through the door, which
inputs into the calculation of thermal
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conduction, is determined using
National Fenestration Rating Council
(NFRC) 100–2010, ‘‘Procedure for
Determining Fenestration U-factors’’
(NFRC 100–2010), which is
incorporated by reference at 10 CFR
431.303.
For walk-in non-display panels and
non-display doors, in the final rule
published on April 15, 2011, DOE
codified in the CFR the standards
established in EPCA based on the Rvalue metric,3 expressed in units of (hft2-°F/Btu),4 which is calculated as the
thickness of the panel in inches (in.)
divided by the K-factor.5 See 10 CFR
431.304(b)(3) and 10 CFR part 431,
subpart R, appendix B, ‘‘Uniform Test
Method for the Measurement of R-Value
for Envelope Components of Walk-in
Coolers and Walk-in Freezers’’
(appendix B). (See also 42 U.S.C.
6314(a)(9)(A)) The K-factor is calculated
based on ASTM International (ASTM)
C518, ‘‘Standard Test Method for
Steady-State Thermal Transmission
Properties by Means of the Heat Flow
Meter Apparatus’’ (ASTM C518), which
is incorporated by reference at 10 CFR
431.303. Id.
For walk-in refrigeration systems, the
efficiency metric is the annual walk-in
energy factor (‘‘AWEF’’), which is the
ratio of the total heat, not including the
heat generated by the operation of
refrigeration systems, removed, in Btu,
from a walk-in box during a one-year
period of usage for refrigeration to the
total energy input of refrigeration
systems, in watt-hours, during the same
period. AWEF is determined by
conducting the test procedure set forth
in American National Standards
Institute (ANSI)/Air-Conditioning,
Heating, and Refrigeration Institute
(AHRI) Standard 1250 (I–P), ‘‘2009
Standard for Performance Rating of
Walk-in Coolers and Freezers’’ (AHRI
1250–2009), which is incorporated by
reference in 10 CFR 431.303 with
certain adjustments specified in the
CFR. See 10 CFR 431.304(b)(4) and 10
CFR part 431, subpart R, appendix C,
‘‘Uniform Test Method for the
Measurement of Net Capacity and
AWEF of Walk-in Cooler and Walk-in
Freezer Refrigeration Systems’’
(appendix C). A manufacturer may also
determine AWEF using an alternative
efficiency determination method
(AEDM). 10 CFR 429.53(a)(2)(iii). An
AEDM enables a manufacturer to utilize
computer-based or mathematical models
for purposes of determining an
equipment’s energy use or energy
efficiency performance in lieu of testing,
provided certain prerequisites have
been met. 10 CFR 429.70(f).
On August 5, 2015, DOE published its
intention to establish a working group
under the Appliance Standards and
Rulemaking Federal Advisory
Committee (ASRAC) to negotiate energy
conservation standards to replace the
standards established in the final rule
published on June 3, 2014 (79 FR 32050,
‘‘June 2014 ECS Final Rule’’). 80 FR
46521. The established working group
(ASRAC Working Group) assembled its
recommendations into a term sheet 6
(Docket No. EERE–2015–BT–STD–0016,
No. 56) that was presented to and
approved by ASRAC on December 18,
2015 (ASRAC Term Sheet).
The ASRAC Term Sheet provided
recommendations for energy
conservation standards to replace
standards vacated by the United States
Court of Appeals for the Fifth Circuit in
a controlling order issued August 10,
2015. It also included recommendations
regarding definitions for a number of
terms related to the WICF regulations, as
well as recommendations to amend the
test procedure that the ASRAC Working
Group viewed as necessary to properly
implement the energy conservation
standards recommendations.
Consequently, in 2016 DOE initiated
both an energy conservation standards
rulemaking and a test procedure
rulemaking to implement these
recommendations. The ASRAC Term
Sheet also included recommendations
for future amendments to the test
procedures intended to make DOE’s test
procedures more fully representative of
walk-in energy use.
On December 28, 2016, DOE
published a final rule amending the
WICF test procedures (‘‘December 2016
Final Rule’’), consistent with the
ASRAC Term Sheet recommendations
and including provisions to facilitate
implementation of energy conservation
standards for walk-in components. 81
FR 95758.
In 2020, AHRI published an updated
industry test standard for walk-in
refrigeration systems, ‘‘2020 Standard
for Performance Rating of Walk-in
Coolers and Freezers,’’ (AHRI 1250–
2020) updating the existing AHRI
standard ‘‘AHRI 1250P (I–P)-2009.’’ This
new test procedure included updated
calculations for the determination of
default values for equipment with
electric defrost and hot gas defrost. DOE
published a final rule for hot gas defrost
unit coolers on March 26, 2021 (March
2021 Final Rule), that amended the test
procedure to rate hot gas defrost unit
coolers using the modified default
values for energy use and heat load
contributions in AHRI 1250–2020.
These amendments ensure that ratings
for hot gas defrost unit coolers are
consistent with those of electric defrost
unit coolers. 86 FR 16027.
Under 10 CFR 431.401, any interested
person may submit a petition for waiver
from DOE’s test procedure
requirements. DOE will grant a waiver
from the test procedure requirements if
DOE determines either the basic model
for which the waiver was requested
contains a design characteristic that
prevents testing of the basic model
according to the prescribed test
procedures, or the prescribed test
procedures evaluate the basic model in
a manner so unrepresentative of its true
energy consumption characteristics as to
provide materially inaccurate
comparative data. 10 CFR 431.401(f)(2).
DOE may grant the waiver subject to
conditions, including adherence to
alternate test procedures specified by
DOE. Id. DOE has granted interim
waivers and/or waivers to the
manufacturers listed in Table I.1.
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TABLE I.1—MANUFACTURERS WHO RECEIVED A TEST PROCEDURE WAIVER/INTERIM WAIVER FROM DOE
Manufacturer
Subject
Jamison Door Company ...............................................
HH Technologies ..........................................................
Percent Time Off (PTO) for Door Motors .....................
PTO for Door Motors ....................................................
3 The R-value is the thermal resistance, or the
capacity of an insulated material to resist heat flow.
See section 3.3.3 of ASTM C518. See 42 U.S.C.
6313(f)(1)(C) for the EPCA R-value requirements for
non-display panels and doors.
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4 These symbols represent the following units of
measurement—h: hour; ft2: square foot; °F: degrees
Fahrenheit; Btu: British thermal unit.
5 The K-factor represents the thermal conductivity
of a material, or its ability to conduct heat, in units
of Btu-in/(h-ft2-°F). See section 3.3.1 of ASTM
C518.
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Case No.
2017–009
2018–001
Waiver from
appendix
A
A
6 Appliance Standards and Rulemaking Federal
Advisory Committee Refrigeration Systems Walk-in
Coolers and Freezers Term Sheet, available at
www.regulations.gov/document/EERE-2015-BTSTD-0016-0056.
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TABLE I.1—MANUFACTURERS WHO RECEIVED A TEST PROCEDURE WAIVER/INTERIM WAIVER FROM DOE—Continued
Manufacturer
Subject
Senneca Holdings ........................................................
Hercules ........................................................................
Heat Transfer Products Group, LLC (HTPG) ...............
Hussmann Corporation (Hussmann) ............................
KeepRite Refrigeration, Inc. (KeepRite) .......................
RefPlus, Inc. .................................................................
Refrigerated Solutions Group (RSG) ...........................
Store It Cold .................................................................
CellarPro .......................................................................
Air Innovations ..............................................................
Vinotheque ....................................................................
Vinotemp .......................................................................
LRC Coil Company (LRC Coil) ....................................
PTO for Door Motors ....................................................
PTO for Door Motors ....................................................
CO2 Unit Coolers ..........................................................
CO2 Unit Coolers ..........................................................
CO2 Unit Coolers ..........................................................
CO2 Unit Coolers ..........................................................
Multi-Circuit Single-Package Dedicated Systems ........
Single-Packaged Dedicated Systems ..........................
Wine Cellar Refrigeration Systems ..............................
Wine Cellar Refrigeration Systems ..............................
Wine Cellar Refrigeration Systems ..............................
Wine Cellar Refrigeration Systems ..............................
Wine Cellar Refrigeration Systems ..............................
On June 17, 2021, DOE published a
request for information (RFI) to initiate
a test procedure rulemaking for walk-ins
(June 2021 RFI). 86 FR 32332. DOE
published a notice of proposed
rulemaking (NOPR) on April 21, 2022
(April 2022 NOPR), responding to
comments received in response to the
June 2021 RFI and presenting DOE’s
proposals to amend the WICFs test
procedure—including amendments to
eliminate the need for existing test
procedure waivers—and establish a new
test procedure at 10 CFR part 431,
subpart R, appendix C1 (appendix C1),
that would establish a new energy
Case No.
Waiver from
appendix
2020–002
2020–013
2020–009
2020–010
2020–014
2021–006
2022–004
2018–002
2019–009
2019–010
2019–011
2020–005
2020–024
A
A
C
C
C
C
C
C
C
C
C
C
C
efficiency metric, AWEF2. 87 FR 23920.
DOE held a public meeting related to
the April 2022 NOPR on May 9, 2022.
DOE received comments in response
to the April 2022 NOPR from the
interested parties listed in Table I.2.
TABLE I.2—LIST OF COMMENTERS WITH WRITTEN SUBMISSIONS IN RESPONSE TO THE APRIL 2022 NOPR
Reference in this Final Rule
Air-Conditioning, Heating, & Refrigeration Institute ..................
Air-Conditioning, Heating, & Refrigeration Institute ..................
Anthony International ................................................................
Appliance Standards Awareness Project, American Council
for an Energy-Efficient Economy, Natural Resources Defense Council, Northwest Energy Efficiency Alliance.
Bally Refrigerated Boxes, Inc ...................................................
Heat Transfer Products Group, LLC .........................................
Hussmann Corporation .............................................................
KeepRite Refrigeration, Inc .......................................................
Lennox International Inc ...........................................................
National Refrigeration & Air Conditioning Canada Corp ..........
North American Association of Food Equipment .....................
Pacific Gas and Electric Company, San Diego Gas & Electric,
and Southern California Edison; collectively, the California
Investor-Owned Utilities.
Refrigerated Solutions Group ...................................................
Senneca Holdings .....................................................................
AHRI 7 .....................................
AHRI-Wine 8 ............................
Anthony ...................................
Efficiency Advocates ...............
30
30
31
37
Bally ........................................
HTPG ......................................
Hussmann ...............................
KeepRite .................................
Lennox ....................................
National Refrigeration .............
NAFEM ...................................
CA IOUs ..................................
40
32
34, 38
36
35
39
33
42
RSG ........................................
Senneca ..................................
41
26
Aparenthetical reference at the end of
a comment quotation or paraphrase
provides the location of the item in the
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Comment No.
in the docket
Commenter(s)
7 AHRI submitted two comment documents to the
docket. The first document in the docket includes
AHRI’s comments for traditional walk-in
manufacturers (i.e., medium- and low-temperature
walk-in components). The associated file name in
the docket is: AHRI Comments WICF NOPR EERE–
2017–BT–TP–0010. These comments are referenced
in this document as ‘‘AHRI’’ comments.
8 AHRI submitted two comment documents to the
docket. The second document in the docket
includes AHRI’s comments supporting wine cellar
manufacturers (i.e., high-temperature walk-in
refrigeration systems). The associated file name in
the docket is: Comments WICF NOPR EERE–2017–
BT–TP–0010 Wine. These comments are referenced
in this document as ‘‘AHRI-Wine’’ comments.
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public record.9 To the extent that
interested parties have provided written
comments that are substantively
consistent with any oral comments
provided during the May 2022 public
meeting, DOE cites the written
comments throughout this final rule.
In response to the April 2022 NOPR,
NAFEM commented that while the
April 2022 NOPR was not inconsistent
9 The parenthetical reference provides a reference
for information located in the docket of DOE’s
rulemaking to develop test procedures for walk-ins
(Docket No. EERE–2017–BT–TP–0010, maintained
at www.regulations.gov). The references are
arranged as follows: (commenter name, comment
docket ID number, page of that document).
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Commenter type
Trade Association.
Trade Association.
Manufacturer.
Efficiency Organizations.
Manufacturer.
Manufacturer.
Manufacturer.
Manufacturer.
Manufacturer.
Manufacturer.
Trade Association.
Utility Association.
Manufacturer.
Manufacturer.
with DOE’s Process Rule,10 NAFEM
supports the U.S. Small Business
Administration Office of Advocacy
request 11 that DOE reopen public
comment on the 2021 Process Rule and
10 The term ‘‘Process Rule’’ refers to DOE’s
Procedures, Interpretations, and Policies for
Consideration of New or Revised Energy
Conservation Standards and Test Procedures for
Consumer Products and Certain Commercial/
Industrial Equipment at 10 CFR part 430, subpart
C, appendix A.
11 The U.S. Small Business Administration Office
of Advocacy request is available at
cdn.advocacy.sba.gov/wp-content/uploads/2022/
05/13104422/Comment-Letter-DOE-Process-RuleLetter_5-13-22.pdf.
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concurrent proposed rulemaking.12
(NAFEM, No. 33 at p. 2) The request
referenced by NAFEM specifically refers
to a National Academies of Sciences
(‘‘NAS’’) report entitled ‘‘Review of
Methods Used by the U.S. Department
of Energy in Setting Appliance and
Equipment Standards.’’ Given that the
recommendations in the NAS report
pertain to the processes by which DOE
analyzes energy conservation standards,
DOE will consider this comment in a
separate rulemaking that includes all
product categories.
II. Synopsis of the Final Rule
In this final rule, DOE is expanding
the scope of its walk-in coolers and
freezers test procedure to include
carbon dioxide (CO2) unit coolers,
multi-circuit single-packaged dedicated
systems, and ducted fan coil units. DOE
has also determined that liquid-cooled
refrigeration systems are within the
scope of DOE coverage authority for
walk-ins but is not adding an applicable
test procedure at this time.
In this final rule, DOE is amending
the definitions of walk-in cooler and
walk-in freezer, door, door surface area,
and single-packaged dedicated systems.
DOE is also adding new definitions for
door leaf, hinged vertical door, nondisplay door, roll-up door, sliding door,
high-temperature refrigeration systems,
ducted fan coil units, multi-circuit
single-packaged dedicated systems,
ducted multi-circuit single-packaged
dedicated systems, attached split
systems, detachable single-packaged
dedicated systems, and CO2 unit
coolers.
In this final rule, DOE is revising
appendix A as follows: (1) incorporate
by reference NFRC 102–2020 as the
applicable test procedure to determine
door ‘‘U-factor’’ in place of NFRC 100–
2010; 13 (2) provide further detail on and
distinguish the area to be used for
calculating a thermal load from U-factor
and determining compliance with
standards; (3) establish a percent time
off (‘‘PTO’’) specific to door motors; and
(4) reorganize appendix A so it is easier
to follow.
Additionally, DOE is modifying
appendix B to improve test
representativeness and repeatability.
Specifically, DOE is revising appendix B
as follows: (1) reference the updated
industry standard ASTM C518–17; (2)
include more detailed provisions for
determining measuring insulation
thickness and test specimen thickness;
(3) provide additional specifications for
determining parallelism and flatness of
a test specimen; and (4) reorganize
appendix B as a step-by-step procedure
to improve readability.
DOE is also including walk-in doors
and walk-in panels in the list of covered
equipment in the same sampling plan
for enforcement testing that is used for
walk-in refrigeration systems. (See 10
CFR 429.110(e)(2))
In this final rule, DOE is making two
sets of changes to the refrigeration
system test procedure. One set of
changes is grouped into revisions to
appendix C, and the other set of changes
is included in a new appendix C1. DOE
has determined that the changes to
appendix C will not affect AWEF ratings
and therefore will not require any
retesting or recertification. These
changes will be required starting 180
days after the test procedure final rule
is published. DOE is also establishing a
new metric, AWEF2, in the new
appendix C1, which will require
retesting and recertification. Use of
appendix C1 will not be required until
the compliance date of amended energy
conservation standards for WICFs that
DOE may ultimately adopt as part of a
separate rulemaking.
DOE is revising appendix C, as
follows:
(1) Specify refrigeration test room
conditions.
(2) Provide for a temperature probe
exception for small diameter refrigerant
lines.
(3) Incorporate a test setup hierarchy
of installation instructions for
laboratories to follow when setting up a
unit for test.
(4) Allow active cooling of the liquid
line in order to achieve the required 3
°F subcooling at a refrigerant mass flow
meter.
(5) Modify instrument accuracy and
test tolerances.
(6) Address current test procedure
waivers for CO2 unit coolers tested
alone and high-temperature unit coolers
tested alone by incorporating
amendments appropriate for this
equipment.
The new appendix C1 includes these
changes to appendix C, as well as the
following additional changes:
(1) Adopt AHRI 1250–2020.
(2) Provide for testing single-packaged
dedicated systems, detachable singlepackaged dedicated systems; attached
split systems; CO2, variable-, two-, and
multiple-capacity dedicated condensing
units; indoor variable-, two-, and
multiple-capacity matched pairs;
matched refrigeration systems for hightemperature applications; and multicircuit single-packaged dedicated
systems.
(3) Add a single-packaged dedicated
system refrigerant enthalpy test
procedure.
(4) Add a new energy efficiency
metric, AWEF2, to reflect the changes in
the test procedure that would result in
a significant change to energy use values
compared to the AWEF metric in
appendix C.
Table II.1 summarizes the current
DOE test procedure, DOE’s changes to
the test procedure, the attribution for
each proposed change, and the relevant
test procedure appendix.
TABLE II.1—SUMMARY OF CHANGES IN TEST PROCEDURE RELATIVE TO CURRENT TEST PROCEDURE
ddrumheller on DSK120RN23PROD with RULES2
WICF component(s)
DOE test procedure prior to
amendment
Doors and Display Panels.
Incorporates by reference NFRC
100–2010 for determining Ufactor as part of determining
energy consumption.
Doors and Display Panels.
Uses surface area of the door or
display panel external to the
walk-in to convert U-factor into
a conduction load.
12 DOE published a NOPR and request for
comment on July 7, 2021, proposing changes to the
Process Rule. 86 FR 35668.
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Amended test procedure
Attribution
Relevant
appendix
Incorporates by reference NFRC
102–2020 for determining Ufactor and allows AEDMs to be
used for determining energy
consumption.
Requires that area of the aperture or surface area used to
determine U-factor be used to
convert U-factor into a conduction load.
Reduce test burden .....................
A
Improve representative values .....
A
13 As discussed further in section III.C.1.b of this
final rule, DOE is also adopting AEDM provisions
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for doors in 10 CFR 429.53 to allow calculation of
door energy use representations.
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28785
TABLE II.1—SUMMARY OF CHANGES IN TEST PROCEDURE RELATIVE TO CURRENT TEST PROCEDURE—Continued
WICF component(s)
DOE test procedure prior to
amendment
Amended test procedure
Doors ............................
Uses a PTO value of 25 percent
for door motors (as they are
considered ‘‘other electricityconsuming devices’’).
Incorporates by reference ASTM
C518–04.
Does not include detailed provisions for determining and
measuring total insulation thickness and test specimen thickness.
Requires that the test specimen
meet a parallelism and flatness
tolerance of ±0.03 inches but
provides no guidance on measurement.
Does not include guidance on
test room conditioning.
Does not include an allowance
for measuring refrigerant temperatures with surface-mounted
measuring instruments.
Establishes a PTO value of 97
percent specific to door motors.
Improve representative values
and address inconsistent values across waivers granted.
A
Incorporates by reference ASTM
C518–17.
Includes detailed provisions for
determining and measuring
total insulation thickness and
test specimen thickness.
Update applicable industry test
procedures.
Ensure test repeatability ..............
B
Provides specifications for determining parallelism and flatness
of the test specimen.
Ensure test repeatability ..............
B
Includes guidance on test room
conditioning.
Includes an allowance for measuring refrigerant temperatures
with surface-mounted measuring instruments for small diameter tubes.
Includes guidance for unit charging and a setup condition hierarchy.
Includes provisions for testing
CO2 unit coolers.
Includes provisions for testing
high-temperature unit coolers
alone.
Incorporates by reference AHRI
1250–2020, ASHRAE 37–2009,
and ASHRAE 16–2016.
Includes multiple methods for
testing single-packaged dedicated systems.
Ensure test repeatability ..............
C
Reduce test burden .....................
C
Ensure test repeatability ..............
C
Improve representative values .....
C
Improve representative values .....
C
Update applicable industry test
procedures.
C1
Improve representative values .....
C1
Improve representative values .....
C1
Improve representative values .....
C1
Improve representative values .....
C1
Improve representative values .....
C1
Improve representative values .....
C1
Non-display Doors and
Panels.
Non-display Doors and
Panels.
Non-display Doors and
Panels.
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
Refrigeration Systems ..
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Refrigeration Systems ..
Does not include guidance for
unit charging or a setup condition hierarchy.
Does not include provisions for
testing CO2 unit coolers.
Does not include provisions for
testing high-temperature unit
coolers alone.
Incorporates by reference AHRI
1250–2009, ASHRAE 23.1–
2010, and AHRI 420–2008.
Tests single-packaged dedicated
systems using the refrigerant
enthalpy method for matched
pairs.
Does not include provisions for
testing attached split systems
or detachable single-packaged
dedicated systems.
Does not include provisions for
testing multi-circuit single-packaged dedicated systems.
Does not include provisions for
testing ducted fan coil units.
Does not include provisions for
testing high-temperature
matched-pair and single-packaged dedicated systems.
Does not include provisions for
testing of variable- and multiple-capacity dedicated condensing units nor variable- and
multiple-capacity outdoor
matched pairs.
DOE has determined that the
amendments described in section III.C
and III.E of this final rule would not
alter the measured energy consumption
of walk-in doors without motors or the
R-value of walk-in non-display doors
and non-display panels. Therefore,
retesting or recertification would not be
required solely as a result of DOE’s
adoption of the amendments to the test
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Includes provisions for testing attached split systems or detachable single-packaged dedicated
systems.
Includes provisions for testing
multi-circuit single-packaged
dedicated systems.
Includes provisions for testing
ducted fan coil units.
Includes provisions for testing
high-temperature matched-pair
and single-packaged dedicated
systems.
Includes provisions for testing of
variable, two-, and multiple-capacity dedicated condensing
units and variable, two-, and
multiple-capacity outdoor
matched pairs.
procedures. Additionally, DOE has
determined that the amendments would
not increase the cost of testing.
For walk-in doors with motors, DOE
has determined that the amendments
described in section III of this final rule
would either not change the measured
energy consumption or would result in
a lower measured energy consumption
and therefore, would not require
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Attribution
Relevant
appendix
B
retesting or recertification as a result of
DOE’s adoption of the amendments to
the test procedures. New testing is only
required if the manufacturer wishes to
make claims using the new, more
efficient rating. Additionally, DOE has
determined the amendments would not
increase the cost of testing for doors
with motors.
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DOE has also determined that the
amendments to appendix C, described
in section III.F of this final rule would
not alter the measured efficiency of
walk-in refrigeration systems and would
not require retesting or recertification as
a result of DOE’s adoption of the
amendments to the test procedures.
Additionally, DOE has determined that
the amendments would not increase the
cost of testing.
Finally, DOE has determined that the
provisions of the new appendix C1
described in section III.G of this final
rule would alter the measured efficiency
of walk-in refrigeration systems, in part
because the amended test procedure
adopts a different energy efficiency
metric than in the current test
procedure. However, the use of
appendix C1 is not required for use
until the compliance date of any
amended energy conservation standards
based on the test procedure in appendix
C1. Additionally, DOE has determined
that the provisions in appendix C1 will
increase the cost of testing. DOE’s
estimation of costs is discussed in
section III.K of this document.
The effective date for the amended
test procedures adopted in this final
rule is 30 days after publication of this
document in the Federal Register.
Representations of energy use or energy
efficiency must be based on testing in
accordance with the amended
appendices A, B, and C test procedures
beginning 180 days after the publication
of this final rule. Manufacturers will be
required to certify compliance using the
new appendix C1 test procedures
beginning on the compliance date of any
final rule establishing amended energy
conservation standards for walk-in
refrigeration systems that are published
after the effective date of this final rule.
III. Discussion
A. Scope and Definitions
This final rule applies to the test
procedures for ‘‘walk-in coolers and
walk-in freezers.’’ The following
sections discuss DOE’s consideration of
the scope of the test procedures and
relevant definitions.
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1. Scope
The following sections discuss
considerations and adopted changes
regarding the scope of equipment
covered by DOE’s test procedures for
walk-ins.
a. Liquid-Cooled Refrigeration Systems
A liquid-cooled refrigeration system
rejects heat during the condensing
process to a liquid, and the liquid
transports the heat to a remote location.
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This contrasts with an air-cooled
system, which rejects heat to ambient
air during the condensing process. The
current DOE test procedure for walk-in
refrigeration systems, which
incorporates by reference AHRI 1250–
2009, does not address how to test
liquid-cooled systems. Additionally,
liquid-cooled dedicated condensing
units are outside the scope of AHRI
1250–2020, being specifically excluded
in Section 2.2.4. In the April 2022
NOPR, DOE tentatively determined that
liquid-cooled refrigeration systems
represent a small portion of the walk-in
market, and thus DOE did not propose
to amend its test procedures to include
liquid-cooled refrigeration systems. 87
FR 23920, 23927.
In response to the April 2022 NOPR,
the Efficiency Advocates and CA IOUs
encouraged DOE to develop a test
procedure for liquid-cooled refrigeration
systems. (Efficiency Advocates, No. 37
at p. 3; CA IOUs, No. 42 at p. 5)
DOE recognizes the potential benefit
of a test procedure for liquid-cooled
walk-ins and the value that a reliable
test procedure can provide to facilitate
comparable representations of energy
use for consumers. However, DOE
maintains that liquid-cooled
refrigeration systems represent a small
portion of the walk-in market, and the
potential for energy savings that could
be realized through the development of
a test procedure and corresponding
energy conservation standards is likely
limited at this time. Additionally, DOE
is not aware of an industry test standard
for liquid cooled walk-in refrigeration
systems. Therefore, although liquidcooled refrigeration systems are covered
within the scope of the walk-in coolers
and walk-in freezers definition, DOE is
not adopting provisions specific to
liquid-cooled refrigeration systems in its
test procedure at this time.
b. Carbon Dioxide Systems
Currently, the DOE test procedure for
walk-in refrigeration systems does not
explicitly define scope based on
refrigerant. See 10 CFR 431.301 and
431.304 and appendix C. DOE
understands that the current test
procedure, which is based on AHRI
1250–2009 (incorporated by reference,
10 CFR 431.303(b)), specifies test
conditions that may not be consistent
with the design and operation of carbon
dioxide (‘‘CO2’’) refrigeration systems
(i.e., although AHRI 1250–2009 does not
specifically exclude CO2 systems, the
test method is not designed to
accommodate such systems).14
14 The DOE test procedure for unit coolers
requires testing with a liquid inlet saturation
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As a result, DOE has granted waivers
or interim waivers to manufacturers
from appendix C, for specific basic
models of CO2 unit coolers.15 The
alternate test procedure granted in these
waivers and DOE’s amendments with
respect to refrigeration systems utilizing
CO2 as a refrigerant are further
discussed in section III.F.6 of this
document.
In the April 2022 NOPR, DOE
tentatively determined that walk-in
refrigeration equipment utilizing CO2 as
a refrigerant meets the definition of a
walk-in refrigeration system. In the
April 2022 NOPR, DOE proposed test
procedure provisions specific to (1)
single-packaged dedicated systems and
(2) unit cooler variants of CO2
refrigeration systems. DOE did not
propose test procedure provisions
specific to CO2-dedicated condensing
units.16
In response to the April 2022 NOPR,
the CA IOUs and HTPG stated that CO2dedicated condensing units are
available on the market in the United
States. (CA IOUs, No. 42 at p. 4; HTPG,
No. 32 at p. 2) The CA IOUs, HTPG, and
the Efficiency Advocates encouraged
DOE to develop a test procedure for
CO2-dedicated condensing units. (CA
IOUs, No. 42 at p. 4; HTPG, No. 32 at
p. 2; Efficiency Advocates, No. 37 at p.
2)
DOE has conducted additional market
research and determined that while CO2
dedicated condensing units are
currently available in the United States
the market is small. In addition, due to
COVID supply constraints, DOE has not
been able to procure a CO2 dedicated
condensing unit to evaluate for testing.
Therefore, DOE is not adopting a test
procedure for CO2 dedicated condensing
units at this time. The test procedures
for CO2 unit coolers and singlepackaged dedicated systems that use
CO2 as a refrigerant are discussed in
temperature of 105 °F and a liquid inlet subcooling
temperature of 9 °F, as specified by Tables 15 and
16 of AHRI 1250–2009. However, CO2 has a critical
temperature of 87.8 °F; therefore, it does not coexist
as saturated liquid and gas above this temperature.
The liquid inlet saturation temperature of 105 °F
and the liquid inlet subcooling temperature of 9 °F
specified in appendix C, are not achievable by CO2
unit coolers.
15 HTPG Decision and Order, 86 FR 14887 (Mar.
19, 2021); Hussmann Decision and Order, 86 FR
24606 (May 7, 2021); KeepRite Decision and Order,
86 FR 24603 (May 7, 2021); RefPlus Interim Waiver,
86 FR 43633 (Aug. 10, 2021).
16 As discussed in the April 2022 NOPR, DOE
preliminarily found that, in the North American
market, CO2 is primarily used in large rack systems,
and there do not appear to be any CO2 dedicated
condensing units available. Hence, DOE tentatively
found that adopting a test procedure for CO2
dedicated condensing units is currently not
warranted. 87 FR 23920, 23928.
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more detail in sections III.F.6 and
III.G.2.g of this document, respectively.
c. Multi-Circuit Single-Packaged
Dedicated Systems
DOE published an interim test
procedure waiver for Refrigerated
Solutions Group (RSG) on July 22, 2022.
87 FR 43808. In its petition for waiver
and interim waiver, RSG stated that the
current walk-in test procedure does not
address multiple refrigeration circuits
enclosed in a single unit. DOE has
determined that refrigeration systems
with multiple refrigeration circuits that
share a single evaporator and a single
condenser and that are used in walk-in
applications meet the definition of
‘‘walk-in cooler and walk-in freezer.’’
Thus, DOE is adding a definition for
‘‘multi-circuit single-packaged
dedicated system,’’ as discussed in
section III.A.2.e of this document, and
adopting a test procedure for such
systems, as discussed in section III.G.2.f
of this document.
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d. Ducted Units
As discussed in the April 2022 NOPR,
DOE is aware that some walk-in
evaporators and/or dedicated
condensing units are sold with
provisions to be installed with ducting
to circulate air between the walk-in and
the refrigeration system; however, unit
cooler and single-packaged systems sold
for ducted installation are not addressed
by either the definition for ‘‘singlepackaged dedicated system’’ or ‘‘unit
cooler.’’ 87 FR 23920, 23928. The
current definition of ‘‘single-packaged
dedicated system’’ specifies that such
systems do not have ‘‘any element
external to the system imposing
resistance to flow of the refrigerated
air,’’ and the definition of ‘‘unit cooler’’
specifies that such equipment does not
have ‘‘any element external to the cooler
imposing air resistance.’’ 10 CFR
431.302. As such, unit coolers and
single-packaged dedicated systems sold
for ducted installation are not addressed
by either definition. In addition, the
current test procedure does not include
provisions for the setup of ductwork.
While the definition of ‘‘condensing
unit’’ does not exclude systems
intended for ducted installation, the
current test procedure also does not
include provisions for setup of
ductwork for these components.
DOE has granted waivers from the test
procedure in appendix C, to CellarPro,
Air Innovations, Vinotheque, and
Vinotemp, and an interim waiver to LRC
Coil, for walk-ins marketed for use as
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wine cellar refrigeration systems.17
Relevant to the present discussion of
scope, the specific basic models for
which waivers have been granted
include equipment sold as ducted units.
In this final rule, DOE is revising the
single-packaged dedicated system
definition to clarify that such systems
may have provisions for ducted
installation. DOE is adding a definition
for ‘‘ducted fan coil unit,’’ the ducted
equivalent of a unit cooler, as discussed
in section III.A.2.d of this document. In
doing so, DOE preserves the industry
standard definition of a unit cooler
while expanding the scope of the test
procedure to ducted units. DOE is also
adding provisions in the test procedures
to address setup of ductwork and the
external static pressure that it imposes
on refrigeration system fans—all to
improve the representativeness of the
test procedure for ducted units. These
test procedure revisions are addressed
in section III.G.6 of this document.
2. Definitions
a. Walk-In Cooler and Walk-In Freezer
DOE currently defines the term
‘‘walk-in cooler and walk-in freezer’’ as
an enclosed storage space refrigerated to
temperatures, respectively, above, and
at or below 32 degrees Fahrenheit, that
can be walked into, and has a total
chilled storage area of less than 3,000
square feet; however, the term does not
include products designed and
marketed exclusively for medical,
scientific, or research purposes. 10 CFR
431.302. (See also 42 U.S.C. 6311(20))
To align the definition of walk-in
cooler and walk-in freezer with the
regulatory scheme adopted by DOE—
which establishes separate test
procedures and energy conservation
standards for the principal components
that make up a walk-in: panels, doors,
and refrigeration systems—in the April
2022 NOPR, DOE proposed to amend
the definition to specify that a walk-in
may comprise these principal
components. DOE requested comment
on this proposed change. 87 FR 23920,
23928.
AHRI, Anthony, RSG, HTPG,
KeepRite, Lennox, and National
Refrigeration agreed with DOE’s
proposed changes to the definition of
walk-in cooler and walk-in freezer.
(AHRI, No. 30 at p. 2; Anthony, No. 31
at p. 1; RSG, No. 41 at p. 1; HTPG, No.
32 at p. 2; KeepRite, No. 36 at p. 1;
17 CellarPro Decision and Order, 86 FR 26496
(May 14, 2021); Air Innovations Decision and
Order, 86 FR 23702 (May 4, 2021); Vinotheque
Decision and Order, 86 FR 26504 (May 14, 2021);
Vinotemp Decision and Order, 86 FR 36732 (July
13, 2021); LRC Coil Interim Waiver, 86 FR 47631
(Aug. 26, 2021).
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28787
Lennox, No. 35 at p. 2; National
Refrigeration, No. 39 at p. 1) For the
reasons discussed in the previous
paragraph and the April 2022 NOPR,
DOE is adopting the definition proposed
in the April 2022 NOPR that ‘‘walk-in
cooler and walk-in freezer’’ means an
enclosed storage space, including but
not limited to panels, doors, and
refrigeration systems, refrigerated to
temperatures, respectively, above, and
at or below 32 degrees Fahrenheit that
can be walked into, and has a total
chilled storage area of less than 3,000
square feet; however, the terms do not
include products designed and
marketed exclusively for medical,
scientific, or research purposes.
The Efficiency Advocates commented
that refrigerated shipping containers
should be within the scope of the walkin test procedures. (Efficiency
Advocates, No. 37 at p. 4) DOE notes
that based on its initial research, neither
the previous definition of walk-in cooler
and walk-in freezer nor the amended
definition adopted in this final rule
would specifically exclude refrigerated
shipping containers. However, DOE has
not evaluated refrigerated shipping
containers to determine if current walkin test procedures would produce test
results that reflect energy efficiency,
energy use, or estimated operating costs
during a representative average use
cycle, without being unduly
burdensome to conduct. Therefore, DOE
has determined that refrigerated
shipping containers are not currently
subject to the DOE test procedure or
energy conservation standards for
WICFs. DOE may consider whether test
procedures and energy conservation
standards should be applied to
refrigerated shipping containers in
future rulemakings.
b. Doors
With respect to walk-ins, DOE defines
a ‘‘door’’ as an assembly installed in an
opening on an interior or exterior wall
that is used to allow access or close off
the opening and that is movable in a
sliding, pivoting, hinged, or revolving
manner of movement. For walk-in
coolers and walk-in freezers, a door
includes the door panel, glass, framing
materials, door plug, mullions, and any
other elements that form the door or
part of its connection to the wall. 10
CFR 431.302.
(1) Door, Door Leaf, and Door Plug
In the April 2022 NOPR, DOE
discussed that the current definition of
‘‘door’’ does not explicitly address that
walk-in door assemblies may contain
multiple door openings within one
frame. 87 FR 23920, 23929. DOE also
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noted that NFRC 100–2010 includes
several defined terms relating to door
components (e.g., door leaf), which
differ from the terms used in DOE’s
definition of ‘‘door.’’ Id. Additionally,
certain stakeholders commented that
they are unfamiliar with the term ‘‘door
plug,’’ whereas others used it to
describe different components of the
door assembly. Id.18
In the April 2022 NOPR, DOE
proposed to amend the definition of
‘‘door’’ to address doors with multiple
openings within one frame, to include
terminology that generally aligns with
that used by the industry, and to remove
use of the term ‘‘door plug.’’ Id.
Specifically, DOE proposed to define
‘‘door’’ as an assembly installed in an
opening on an interior or exterior wall
that is used to allow access or close off
the opening and that is movable in a
sliding, pivoting, hinged, or revolving
manner of movement. For walk-in
coolers and walk-in freezers, a door
includes the frame (including mullions),
the door leaf or multiple door leaves
(including glass) within the frame, and
any other elements that form the
assembly or part of its connection to the
wall. DOE also proposed to define the
term ‘‘door leaf’’ to mean the pivoting,
rolling, sliding, or swinging portion of a
door. Id.
Regarding the proposed definition of
‘‘door,’’ Senneca considered the
proposed definition of ‘‘door’’ to refer to
the door system (i.e., includes the door
leaf, frame, casings, header, tracks, and
all necessary components and
hardware). (Senneca, No. 26 at p. 1)
AHRI commented that its members find
DOE’s current definition unclear and
recommended that DOE not use what
AHRI referred to as the ‘‘single door’’
interpretation. (AHRI, No. 30 at p. 2)
DOE interprets AHRI’s comment to
mean that a door with multiple
openings within a single frame should
not be treated as a single basic model.
DOE notes that the proposed definition
of ‘‘door’’ is consistent with Senneca’s
understanding. Additionally, DOE notes
that the proposed definition intends to
clarify the definition of ‘‘door’’,
particularly, that a ‘‘door’’ consists of a
single frame and includes all parts of
the door assembly attached to the single
frame, including multiple door openings
where applicable.
18 In
response to the June 2021 RFI, Anthony and
AHRI stated that they were unfamiliar with the term
‘‘door plug.’’ (Anthony, No. 8 at pp. 1–2; AHRI, No.
11 at pp. 2–3) In response to the June 2021 RFI,
Imperial Brown and Hussmann commented that
they used the term ‘‘door plug’’ to describe different
components of the door assembly. (Imperial Brown,
No. 15 at p. 1; Hussmann, No. 18 at p. 3)
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Anthony stated that the definition of
‘‘door’’ does not accurately reflect the
use of the term ‘‘door’’ in the 2014 final
rule engineering analysis spreadsheet.19
(Anthony, No. 31 at pp. 1–3)
Specifically, Anthony commented that
when applying the same formula to a
single door with multiple openings,
there is a 20 to 30 percent reduction in
energy allowance per door. Id. DOE
notes that this comment refers to the
representative units used to evaluate
and adopt energy conservation
standards in a final rule published on
June 3, 2014 (79 FR 32050). DOE has
determined that the representative units
used in 2014 met the definition of
‘‘door’’ at the time of the analysis and
would continue to meet the definition of
‘‘door’’ as amended by this final rule.—
The amended definition of ‘‘door’’
adopted in this final rule provides
additional clarity that a door contains a
single frame with one or multiple door
openings. Regarding the energy impacts
of doors with multiple openings, DOE
recommends that stakeholders provide
feedback on the representative unit
characteristics in response to the
ongoing energy conservation standards
rulemaking which is the appropriate
venue to address such concerns (see
docket EERE–2017–BT–STD–0009).
For the reasons discussed in the
preceding paragraphs and the April
2022 NOPR, this final rule adopts the
revised definition of ‘‘door’’ as
proposed.
Bally agreed with the term ‘‘door leaf’’
and stated that the term as defined
would be easily understood. (Bally, No.
40 at p. 1) AHRI stated that DOE’s
proposed definition of ‘‘door leaf’’ is
clear. (AHRI, No. 30 at p. 2) Senneca
commented that it considers ‘‘door leaf’’
to be a movable, insulated portion of the
assembly. (Senneca, No. 26 at p. 10)
DOE has concluded that Senneca’s
comment is consistent with the
proposed definition of ‘‘door leaf.’’ This
final rule adopts the definition of ‘‘door
leaf’’ as proposed in the April 2022
NOPR. 87 FR 23920, 23929.
DOE did not receive any comments
regarding its proposal to remove use of
the term ‘‘door plug.’’ For the reasons
discussed in the April 2022 NOPR, this
final rule removes the term ‘‘door plug’’
as proposed. Id.
(2) Non-Display Door
DOE also proposed to define the term
‘‘non-display door’’ in the April 2022
NOPR. 87 FR 23920, 23930. Although
19 Anthony
is referring to the engineering analysis
for display doors as part of the June 2014 ECS Final
Rule, which can be found at regulations.gov under
docket number EERE–2008–BT–STD–0015–0084.
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the test procedures outlined in 10 CFR
431.304 and appendices A and B use the
term ‘‘non-display door,’’ it is not
currently defined. DOE proposed to
define a ‘‘non-display door’’ as a door
that is not a display door.20
In response to the April 2022 NOPR
discussion of non-display doors,
Hussmann stated that although its
Heavy Duty Door products and ABC
Beer Cave sliding door products are
made largely of glass, it does not believe
these doors meet the display door
definition because they are designed to
be used as passage doors (i.e., passage of
people). (Hussmann, No. 34 at p. 2) In
response, DOE notes that the display
door definition references the physical
characteristics of the door (i.e., the
portion of surface area composed of
glass or another transparent material),
and is not contingent on door
application. Any door(s) that meets this
criteria is considered a display door,
even those not necessarily designed for
product display.
In this final rule, DOE is adopting the
definition of ‘‘non-display door’’ as
proposed in the April 2022 NOPR.
(3) Hinged Vertical Door, Roll-Up Door,
and Sliding Door
In the April 2022 NOPR, DOE
tentatively determined that
differentiating walk-in doors based on
opening characteristics would better
align with industry terminology and
proposed to define three terms to further
differentiate all walk-in doors
(including both display and non-display
doors): ‘‘hinged vertical door,’’ ‘‘roll-up
door,’’ and ‘‘sliding door.’’ 87 FR 23920,
23930.
DOE proposed to define ‘‘hinged
vertical door’’ as a door with a door leaf
(or leaves) with a hinge (or hinges)
connecting one vertical edge of the door
leaf (or leaves) to a frame or mullion of
the door. This includes doors that swing
open in one direction (i.e., into or out
of the walk-in) and free-swinging doors
that open both into and out of the walkin. 87 FR 23920, 23991.
DOE proposed to define ‘‘roll-up
door’’ as a door that bi-directionally
rolls open and closed in a vertical and
horizontal manner and may include
vertical jamb tracks. Id.
DOE proposed to define ‘‘sliding
door’’ as a door having one or more
manually operated or motorized door
leaves within a common frame that slide
horizontally or vertically. Id.
20 DOE defines ‘‘display door’’ as a door that (1)
is designed for product display; or (2) has 75
percent or more of its surface area composed of
glass or another transparent material. 10 CFR
431.302.
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In the April 2022 NOPR, DOE
requested feedback on the proposed
definitions for ‘‘hinged vertical door,’’
‘‘roll-up door,’’ and ‘‘sliding door.’’ Id.
Senneca and AHRI agreed with DOE’s
proposed definitions. (Senneca, No. 26
at p. 1; AHRI, No. 30 at p. 2)
DOE recognizes that these definitions
are not used in the adopted test
procedure amendments. In the
preliminary analysis for the walk-in
standards energy conservation
rulemaking, DOE stated that it was
interested in differentiating its analysis
by door opening characteristics. See
page ES–36 of the preliminary analysis
technical support document (EERE–
2017–BT–STD–0009–0024). DOE is not
adopting definitions for the terms
‘‘hinged vertical door,’’ ‘‘roll-up door,’’
and ‘‘sliding door’’ and will consider
the potential adoption of these terms in
the ongoing energy conservation
standards rulemaking for WICFs.
As discussed in the April 2022 NOPR,
DOE currently differentiates nondisplay doors by whether they are
passage doors or freight doors. 87 FR
23920, 23929. A ‘‘freight door’’ is a door
that is not a display door and is equal
to or larger than 4 feet wide and 8 feet
tall. 10 CFR 431.302. A ‘‘passage door’’
is a door that is not a freight or display
door. Id. After reviewing comments
submitted in response to the June 2021
RFI, DOE did not propose to amend the
definition of freight door or passage
door. DOE again received comments,
however, on the definitions of freight
and passage doors. 87 FR 23920, 23930.
Bally commented that specifying the
way a door leaf is moved would not aid
in defining a door nor clarify whether a
non-display door is a passage or a
freight door. (Bally, No. 40 at p. 1)
Additionally, Bally disagreed with the
current distinction of freight doors by
size, stating that it manufactures doors
with a width greater than or equal to 4
feet that are often the only door in the
WICF; therefore, it considers these doors
to be passage doors rather than freight
doors. Id. Senneca stated that it views
opening size as a determinant to
whether a non-display door is
designated as a passage or freight door
and reiterated that a freight door has a
width-in clear 21 (‘‘WIC’’) greater than or
equal to 4 feet and a height-in-clear 22
21 In their comment in response to the June 2021
RFI, Imperial Brown defined WIC as the clear
opening width, typically from left frame jamb to
right frame jamb. See EERE–2017–BT–TP–0010–
0015 at p. 1.
22 In their comment in response to the June 2021
RFI, Imperial Brown defined HIC as the clear
opening height, typically from door sill to frame
header. See EERE–2017–BT–TP–0010–0015 at p. 1.
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(‘‘HIC’’) greater than or equal to 8 feet.
(Senneca, No. 26 at p. 1)
DOE acknowledges that stakeholder
comments demonstrate that factors
other than size may be used to
differentiate between a passage and
freight door. However, DOE concludes
that size is currently the most suitable
way to differentiate between a passage
door and a freight door. Therefore, DOE
is not amending these definitions.
c. High-Temperature Refrigeration
System
As mentioned previously, DOE has
granted several manufacturers waivers
and interim waivers from the current
test procedure in appendix C for basic
models of refrigeration systems
marketed as wine cellar refrigeration
systems (see section III.A.1.d of this
document). These manufacturers stated
that walk-ins used for wine storage are
intended to operate at a temperature
range of 45 to 65 °F and 50 to 70 percent
relative humidity, rather than the 35 °F
and less than 50 percent relative
humidity test conditions prescribed in
appendix C.
In the April 2022 NOPR, DOE
proposed to define ‘‘high-temperature
refrigeration system’’ as a walk-in
refrigeration system that is not designed
to operate below 45 °F. 87 FR 23920,
23930. DOE did not receive any
feedback from stakeholders on the
proposed definition; however, the CA
IOUs commented that they support DOE
including a test method for hightemperature unit coolers (CA IOUs, No.
42 at p. 6). DOE is adopting the
definition for ‘‘high-temperature
refrigeration system’’ as proposed in the
April 2022 NOPR. Section III.G.6
provides further details of the
corresponding test procedure
provisions.
d. Ducted Fan Coil Unit and Ducted
Single-Packaged Dedicated System
As discussed in the April 2022 NOPR,
the definitions for single-packaged
dedicated systems and unit coolers
currently exclude ducted units. 87 FR
23920, 23931. As a part of the hightemperature refrigeration system
waivers discussed in section III.A.2.c,
DOE has granted waivers to Air
Innovations, Vinotheque, CellarPro, and
Vinotemp, and an interim waiver to LRC
Coil, for walk-ins that are marketed as
wine cellar refrigeration systems that are
designed and marketed as ducted units.
To clarify that refrigeration systems
with provision for ducted installation
are included in the DOE test procedure,
DOE proposed to adopt the new term
‘‘ducted fan-coil unit,’’ defined as an
assembly including means for forced air
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circulation capable of moving air against
both internal and non-zero external flow
resistance and elements by which heat
is transferred from air to refrigerant to
cool the air, with provision for ducted
installation. 87 FR 23920, 23931. DOE
also proposed to revise the current
‘‘single-packaged dedicated system’’
definition to mean a refrigeration system
(as defined in 10 CFR 431.302) that is
a single-packaged assembly that
includes one or more compressors, a
condenser, a means for forced
circulation of refrigerated air, and
elements by which heat is transferred
from air to refrigerant. Id.
In the April 2022 NOPR, DOE
requested comment on its proposed
definition for ‘‘ducted fan coil unit’’ and
on the proposed modification to the
definition of ‘‘single-packaged dedicated
system.’’ Id. RSG agreed with the
proposed definitions. (RSG, No. 41 at p.
1) AHRI and HTPG suggested separate
definitions for ducted and non-ducted
single-packaged dedicated systems.
(AHRI, No. 30 at pp. 2–3; HTPG, No. 32
at p. 2)
After consideration of stakeholder
comments, and to maintain consistency
with industry terminology, DOE is
adopting a separate definition for
‘‘ducted single-packaged dedicated
system’’ that means a refrigeration
system (as defined in 10 CFR 431.302)
that is a single-packaged assembly
designed for use with ducts, that
includes one or more compressors, a
condenser, a means for forced
circulation of refrigerated air, and
elements by which heat is transferred
from air to refrigerant. As such, DOE is
maintaining its current definition of a
‘‘single-packaged dedicated system,’’
and clarifying that it describes nonducted units.
DOE received no feedback from
stakeholders on the proposed definition
for the new term ‘‘ducted fan coil unit.’’
DOE is adopting the definition for
‘‘ducted fan coil unit’’ as proposed in
the April 2022 NOPR.
e. Multi-Circuit Single-Packaged
Dedicated System
In the April 2022 NOPR, DOE
proposed to define a ‘‘multi-circuit
single-packaged dedicated system’’ as a
single-packaged dedicated system (as
defined in 10 CFR 431.302) that
contains two or more refrigeration
circuits that refrigerate a single stream
of circulated air. DOE requested
comment on this proposed definition.
87 FR 23920, 23931.
RSG agreed with the proposed
definition. (RSG, No. 41 at p. 1) AHRI
and HTPG suggested that the proposed
definition is too specific and should be
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broader. (AHRI, No. 30 at p. 3; HTPG,
No. 32 at p. 3) However, AHRI and
HTPG did not provide alternative
definitions or other additional
information that might support
broadening the definition.
In this final rule, DOE is adopting the
definition for ‘‘multi-circuit singlepackaged dedicated refrigeration
system’’ as proposed in the April 2022
NOPR.
As discussed in section III.A.2.d, DOE
proposed to adopt the new term ‘‘ducted
fan-coil unit’’ to clarify that refrigeration
systems with provision for ducted
installation are included in the DOE test
procedure. 87 FR 23920, 23931. In
response to the April 2022 NOPR,
several stakeholders suggested creating
separate definitions for ducted and nonducted single-packaged dedicated
systems. (AHRI, No. 30 at pp. 2–3;
HTPG, No. 32 at p. 2) DOE’s current
definition for a ‘‘single-packaged
dedicated system’’ applies only to nonducted units. As discussed in section
III.A.2.d, after consideration of
stakeholder comments, and to maintain
consistency with industry terminology,
DOE is adopting a definition for ducted
single-packaged dedicated systems
Since ducted multi-circuit singlepackaged dedicated systems are a
derivative of ducted single-packaged
dedicated systems, DOE is also defining
‘‘ducted multi-circuit single-packaged
dedicated systems’’ to mean a ducted
single-packaged dedicated system that
contains two or more refrigeration
circuits that refrigerate a single stream
of circulated air. DOE believes these
amendments are consistent with the
intent of proposed changes in the April
2022 NOPR while being responsive to
stakeholder feedback.
f. Attached Split System
As discussed in the April 2022 NOPR,
DOE is aware of some refrigeration
systems that are sold as matched pairs
in which the dedicated condensing unit
and unit cooler are permanently
attached to each other with structural
beams. 87 FR 23920, 23931. The DOE
test procedure does not currently define
such systems, nor does it provide any
unique test provisions for them, thereby
affecting the ability of manufacturers to
provide test results reflecting the energy
efficiency of this equipment during a
representative average use cycle. DOE
proposed to define ‘‘attached split
system’’ as a matched-pair refrigeration
system designed to be installed with the
evaporator entirely inside the walk-in
enclosure and the condenser entirely
outside the walk-in enclosure, and the
evaporator and condenser are
permanently connected with structural
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members extending through the walk-in
wall. Id.
In the April 2022 NOPR, DOE
requested comment on the proposed
definition for ‘‘attached split system.’’
Id. AHRI, HTPG, Hussmann, and
Lennox agreed with the proposed
definition. (AHRI, No. 30 at p. 3; HTPG,
No. 32 at p. 3; Hussmann, No. 38 at p.
2; Lennox, No. 35 at p. 2)
In this final rule, DOE is adopting the
proposed definition for ‘‘attached split
system.’’ The provisions for testing such
units are discussed in section III.G.4 of
this document.
g. Detachable Single-Packaged System
As discussed in the April 2022 NOPR,
DOE had tentatively determined that
detachable single-packaged systems are
a type of single-packaged dedicated
system, and proposed to define
‘‘detachable single-packaged system’’ as
a system consisting of a dedicated
condensing unit and an insulated
evaporator section in which the
evaporator section is designed to be
installed external to the walk-in
enclosure and circulating air through
the enclosure wall, and the condensing
unit is designed to be installed either
attached to the evaporator section or
mounted remotely with a set of
refrigerant lines connecting the two
components. 87 FR 23920, 23931. The
current DOE test procedure does not
define such systems or provide testing
provisions specific to this configuration.
In the April 2022 NOPR, DOE
requested comment on the proposed
definition for ‘‘detachable singlepackaged dedicated system.’’ Id. AHRI,
HTPG, Lennox, and RSG agreed with
the proposed definition. (AHRI, No. 30
at p. 3; HTPG, No. 32 at p. 3; Lennox,
No. 35 at p. 2; RSG, No. 41 at p. 1)
In this final rule, DOE is adopting the
definition for ‘‘detachable singlepackaged dedicated system’’ as
proposed in the April 2022 NOPR.
h. CO2 Unit Cooler
In the April 2022 NOPR, DOE
proposed a test procedure for CO2 unit
coolers. 87 FR 23920, 23952. To clarify
the scope of the proposed CO2 unit
cooler test procedure, DOE proposed to
define a ‘‘CO2 unit cooler’’ as one that
includes a nameplate listing only CO2 as
an approved refrigerant. 87 FR 23920,
23932.
In the April 2022 NOPR, DOE
requested comment on the proposed
definition of CO2 unit coolers. Id. AHRI,
HTPG, Hussmann, Lennox, National
Refrigeration, and RSG agreed with the
proposed definition. (AHRI, No. 30 at p.
3; HTPG, No. 32 at p. 3; Hussmann, No.
38 at p. 2; Lennox, No. 35 at p. 2;
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National Refrigeration, No. 39 at p. 1;
RSG, No. 41 at p. 1)
DOE also requested comment on
whether any distinguishing features of
CO2 unit coolers exist that could
reliably be used as an alternative
approach to differentiate them from
those unit coolers intended for use with
conventional refrigerants. 87 FR 23920,
23932.
AHRI, HTPG, Lennox, and National
Refrigeration all stated that they were
not aware of any features that
distinguish CO2 unit coolers from those
that use traditional refrigerants. (AHRI,
No. 30 at p. 3; HTPG, No. 32 at p. 3;
Lennox, No. 35 at p. 2; National
Refrigeration, No. 39 at p. 1)
Given that stakeholders are not aware
of any features that distinguish CO2 unit
coolers from those that use traditional
refrigerants, this information must be
provided on the unit in some way.
Therefore, DOE is adopting the ‘‘CO2
unit cooler’’ definition proposed in the
April 2022 NOPR which requires a
nameplate listing only CO2 as an
approved refrigerant for this equipment.
i. Hot Gas Defrost
In the April 2022 NOPR, DOE
proposed that manufacturers of
equipment with hot gas defrost installed
at the factory may make market
representations of performance with hot
gas defrost activated, in addition to the
current required calculation-based
approach using default electric defrost
parameters, and proposed a definition
for ‘‘hot gas defrost’’ to clarify the scope
of the voluntary representation. 87 FR
23920, 23932.
AHRI, HTPG, KeepRite, Lennox,
National Refrigeration, and RSG all
recommended changes to the definition
as proposed. (AHRI, No. 30 at p. 3;
HTPG, No. 32 at p. 3; KeepRite, No. 36
at p. 1; Lennox, No. 35 at p. 2; National
Refrigeration, No. 39 at p. 1; RSG, No.
41 at p. 4) In particular, AHRI, HTPG,
and Lennox stated that not all hot gas
defrost systems are factory installed.
(AHRI, No. 30 at pp. 3–4; HTPG, No. 32
at p. 3; Lennox, No. 35 at p. 2)
DOE intended for the voluntary hot
gas defrost representation provisions
proposed in the April 2022 NOPR to
apply only to factory-installed hot gas
defrost systems. 87 FR 23920, 23970.
Considering the comments received,
DOE recognizes that the proposed
provisions would not apply to many hot
gas defrost applications, thus negating
the purpose and intent of DOE’s
proposal. Therefore, DOE has
determined not to adopt provisions
allowing representations of performance
with hot gas defrost activated at this
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time and consequently is not adopting
a definition for ‘‘hot gas defrost.’’
B. Updates to Industry Standards
The current DOE test procedures for
walk-in coolers and freezers incorporate
the following industry test standards:
NFRC 100–2010 into appendix A;
ASTM C518–04 into appendix B; and
AHRI 1250–2009, AHRI 420–2008,23
and ASHRAE 23.1–2010 24 into
appendix C. The following sections
discuss the industry standards DOE is
incorporating by reference in this final
rule and the relevant provisions of those
industry standards that DOE is
adopting.
1. Industry Standards for Determining
Thermal Transmittance (U-Factor)
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As discussed in the April 2022 NOPR,
appendix A to subpart R of part 431
references NFRC 100–2010 as the
method for determining the U-factor of
doors and display panels, which
references NFRC 102–2010. 87 FR
23920, 23932. NFRC has published
updates to NFRC 102–2010, the most
recent being NFRC 102–2020, which
contains the following substantive
changes from NFRC 102–2010:
1. Added a list of required
calibrations for primary measurement
equipment;
2. Added metering box wall
transducer and surround panel flanking
loss characterization and annual
verification procedure;
3. Incorporated a calibration transfer
standard continuous characterization
procedure; and
4. Revised the provisions regarding air
velocity distribution to be more specific
to the type of fans used.
DOE proposed to adopt by reference
in appendix A the following sections of
NFRC 102–2020 in place of NFRC 100–
2010 for determining U-factor:
• 2. Referenced Documents
• 3. Terminology
• 5. Apparatus
• 6. Calibration
• 7. Experimental Procedure (excluding
7.3. Test Conditions)
• 8. Calculation of Thermal
Transmittance
• 9. Calculation of Standardized
Thermal Transmittance
• Annex A1. Calibration Transfer
Standard Design
23 AHRI 420–2008, ‘‘Performance Rating of
Forced-Circulation Free-Delivery Unit Coolers for
Refrigeration’’ (‘‘AHRI 420–2008’’).
24 ANSI/ASHRAE 23.1–2010, ‘‘Methods of
Testing for Rating the Performance of Positive
Displacement Refrigerant Compressors and
Condensing Units that Operate at Subcritical
Temperatures of the Refrigerant’’ (‘‘ASHRAE 23.1–
2010’’).
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• Annex A2. Radiation Heat Transfer
Calculation Procedure
• Annex A4. Garage Panel and Rolling
Door Installation
87 FR 23920, 23932.
DOE also proposed to incorporate by
reference ASTM C1199–14, as it is
referenced in NFRC 102–2020.
Specifically, in the appendix A test
procedure, DOE proposed to reference
the following sections of ASTM C1199–
14 as referenced through NFRC 102–
2020: sections 2, 3, 5, 6, 7 (excluding
7.3), 8, 9, and annexes A1 and A2. DOE
did not propose to reference any other
sections of NFRC 102–2020 or ASTM
C1199–14, as either they do not apply
or they are in direct conflict with other
test procedure provisions included in
appendix A.
In this final rule, DOE is incorporating
by reference NFRC 102–2020 and ASTM
C1199–14 in appendix A as proposed in
the April 2020 NOPR. DOE further
discusses the reference to NFRC 102–
2020 in place of NFRC 100–2010 and
addresses stakeholder comments in
section III.C.1 of this document.
2. Industry Standard for Determining RValue
As discussed in the April 2022 NOPR,
section 4.2 of appendix B to subpart R
of part 431 references ASTM C518–04 25
to determine the thermal conductivity,
or K-factor, of panel insulation. 87 FR
23920, 23932. ASTM published a
revision of ASTM C518 in July 2017
(‘‘ASTM C518–17’’). Id.
In the April 2022 NOPR, DOE
tentatively determined that the updates
in ASTM C518–17 do not substantively
change the test method and do not
impact test burden compared to ASTM
C518–04. Therefore, DOE proposed to
amend its test procedure for
determining insulation R-value for nondisplay doors and panels by
incorporating by reference ASTM C518–
17. Specifically, in the test procedure in
appendix B, DOE proposed to reference
the following sections of ASTM C518–
17:
• 2. Referenced Documents
• 3. Terminology
• 5. Apparatus
• 6. Calibration
• 7. Test Procedures (excluding 7.3.
Specimen Conditioning)
• 8. Calculation
• Annex A1. Equipment Design
87 FR 23920, 23933.
DOE did not propose to reference any
other sections of ASTM C518–17, as
either they do not apply or they are in
25 ASTM C518–04 is the version of the industry
test procedure specified by EPCA as the basis for
calculating the K-factor.
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direct conflict with other test procedure
provisions included in appendix B.
Because ASTM C518–17 is an updated
version of ASTM C518–04, DOE stated
in the April 2022 NOPR that the test
procedure for determining the K-factor
would effectively remain based on
ASTM C518–04 as specified by EPCA
(42 U.S.C. 6314(a)(9)(A)(ii)).
In response to the April 2022 NOPR,
Anthony supported the proposal to
reference the latest version of the
industry test procedure, ASTM C518–
17. (Anthony, No. 31 at p. 3)
In this final rule, DOE is incorporating
by reference the sections of ASTM
C518–17 as proposed in the April 2022
NOPR.
3. Industry Standards for Determining
AWEF
DOE’s current test procedure for
WICF refrigeration systems is codified
in appendix C to subpart R of part 431
and incorporates by reference AHRI
1250–2009, AHRI 420–2008, and
ASHRAE 23.1–2010. AHRI 1250–2009 is
the industry test standard for walk-in
cooler and freezer refrigeration systems,
including unit coolers and dedicated
condensing units sold separately, as
well as matched pairs. 81 FR 95758,
95798.26 The procedure describes the
method for measuring the refrigeration
capacity and the electrical energy
consumption for a condensing unit and
a unit cooler, including off-cycle fan
and defrost subsystem contributions.
Using the refrigeration capacity and
electrical energy consumption, AHRI
1250–2009 provides a calculation
methodology to compute AWEF, the
applicable energy performance metric
for refrigeration systems.
The DOE test procedure for walk-in
refrigeration systems incorporates by
reference the test procedure in AHRI
1250–2009 (excluding Tables 15 and
16), with certain enumerated
modifications. See appendix C to
subpart R of part 431.
In April 2020, AHRI published AHRI
1250–2020, which incorporates many of
the modifications and additions to AHRI
1250–2009 that DOE currently
prescribes in its test procedure at
appendix C. It also includes test
methods for unit coolers and dedicated
condensing units tested alone, rather
than incorporating by reference updated
versions of AHRI 420–2008 and/or
ASHRAE 23.1–2010. AHRI 1250–2020
also includes test methods for singlepackaged dedicated systems.
The following sections discuss the
amendments being adopted in appendix
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C and appendix C1 with respect to the
aforementioned industry test methods.
a. Appendix C
In the April 2022 NOPR, DOE
proposed minor modifications to
appendix C that improve test procedure
accuracy and repeatability, while
maintaining equivalent measurements
of AWEF. 87 FR 23920, 23933. As
discussed further in the section that
follows, DOE also proposed to establish
a new appendix C1 to subpart R that
would incorporate substantive changes
that would result in different measured
values of efficiency, AWEF2, compared
to appendix C. DOE proposed that the
use of appendix C with the proposed
amendments would be required 180
days after this test procedure final rule
is published and would remain required
for use until the compliance date of any
future amended energy conservation
standards based on appendix C1.
Within appendix C, DOE proposed to
maintain reference to AHRI 1250–2009.
DOE proposed to adopt certain
instrument accuracy and test tolerances
from AHRI 1250–2020 that would not
change the measured AWEF value, as
discussed further in section III.F.5 of
this document.
DOE received no comments on its
proposal to maintain appendix C, with
modification, until the compliance date
of any future amended energy
conservation standards based on
appendix C1.
In this final rule, DOE maintains the
required use of appendix C, as amended
by this final rule, including the
incorporation by reference of AHRI
1250–2009, until the compliance date of
any future amended energy
conservation standards based on
appendix C1.
b. Appendix C1
As discussed, in the April 2022
NOPR, DOE proposed to establish a new
appendix C1 to subpart R that
incorporates by reference AHRI 1250–
2020. 87 FR 23920, 23933. DOE
tentatively determined that the changes
proposed in appendix C1 through the
incorporation of AHRI 1250–2020
would increase the representativeness of
the DOE test procedure for walk-ins.
DOE also tentatively determined that
several of the changes in AHRI 1250–
2020 would change the measured AWEF
value. These changes can be grouped
into five categories: off-cycle tests,
single-packaged dedicated systems,
defrost calculations, variable capacity,
and default unit cooler parameters.
These changes and the comments
received on these proposed changes are
discussed in detail in section III.G.
Since these changes would result in a
change to measured AWEF, DOE
proposed to establish a new metric
called ‘‘AWEF2.’’
In the April 2022 NOPR, DOE
proposed to incorporate AHRI 1250–
2020 for use in appendix C1, with the
following exclusions:
• Section 1 Purpose
• Section 2 Scope
• Section 9 Minimum Data
Requirements for Published Ratings
• Section 10 Marking and Nameplate
Data
• Section 11 Conformance Conditions
• Section C10.2.1.1 Test Room
Conditioning Equipment under
section C10—Defrost Calculation and
Test Methods
87 FR 23920, 23933.
DOE proposed to exclude these
sections of AHRI 1250–2020 because
they either do not apply or conflict with
other test procedure provisions
included in appendix C1.
Further, DOE proposed to reference
ASHRAE 16–2016 in appendix C1, as it
is referenced in AHRI 1250–2020, with
the following exclusions:
• Section 1 Purpose
• Section 2 Scope
• Section 4 Classifications
• Normative Appendices E–M
• Informative Appendices N–R
87 FR 23920, 23934.
DOE did not propose to reference
these sections of ASHRAE 16–2016, as
either they do not apply or they conflict
with other test procedure provisions
that are included as part of appendix
C1.
Similarly, DOE proposed to reference
ASHRAE 37–2009 in appendix C1, as it
is referenced in AHRI 1250–2020, with
the following exclusions:
• Section 1 Purpose
• Section 2 Scope
• Section 4 Classifications
• Informative Appendix A
Classifications of Unitary Airconditioners and Heat Pumps
Id.
DOE did not propose to reference
these sections of ASHRAE 37–2009, as
either they do not apply, or they conflict
with other test procedure provisions
that are included as part of appendix
C1.
As discussed in the April 2022 NOPR,
AHRI 1250–2020 incorporates many of
the modifications and additions to AHRI
1250–2009 that DOE currently
prescribes in its appendix C test
procedure. Id. Since DOE proposed to
adopt AHRI 1250–2020, DOE did not
propose to carry over the sections listed
in Table III.1 from appendix C to
appendix C1.
TABLE III.1—LIST OF SECTIONS IN APPENDIX C NOT PROPOSED TO BE INCLUDED IN APPENDIX C1
Appendix C
Summary
Section 3.1.1 ...................................
Section 3.1.2 ...................................
Section 3.1.3 ...................................
Modifies Table 1 (Instrumentation Accuracy) in AHRI 1250–2009.
Provides guidance on electrical power frequency tolerances.
States that in Table 2 of AHRI 1250–2009, the test operating tolerances and test condition tolerances for
air leaving temperatures shall be deleted.
States that in Tables 2 through 14 in AHRI 1250–2009, the test condition outdoor wet-bulb temperature requirement and its associated tolerance apply only to units with evaporative cooling.
Provides tables to use in place of AHRI 1250–2009 Tables 15 and 16, which are excluded from the reference in 10 CFR 431.303.
Provides specific guidance on how to measure refrigerant temperature.
Removes the requirement to perform a refrigerant composition and oil concentration analysis.
Provides insulation and configuration requirements for liquid and suction lines used for testing.
Gives direction for how to test and rate unit coolers tested alone.
Clarifies that the 2008 version of AHRI Standard 420 should be used for unit coolers tested alone.
Modifies the allowable reduction in fan speed for off-cycle evaporator testing.
Specifies that the 2010 version of ASHRAE 23.1 should be used and that ‘‘suction A’’ condition test points
should be used when testing dedicated condensing units.
Provides instruction on how to calculate AWEF and net capacity for dedicated condensing units.
Provides guidance on how to rate refrigeration systems with hot gas defrost.
Section 3.1.4 ...................................
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Section 3.1.5 ...................................
Section
Section
Section
Section
Section
Section
Section
3.2.1
3.2.2
3.2.5
3.3.1
3.3.2
3.3.3
3.4.1
...................................
...................................
...................................
...................................
...................................
...................................
...................................
Section 3.4.2 ...................................
Section 3.5 ......................................
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AHRI 1250–2020 does not incorporate
all the modifications and additions to
AHRI 1250–2009 that DOE currently
prescribes in its test procedure.
Therefore, DOE proposed that the
modifications in sections 3.2.3, 3.3.4,
3.3.5, and 3.3.7 of appendix C be
incorporated into appendix C1.
In response to the April 2022 NOPR,
DOE received several general comments
about the incorporation of AHRI 1250–
2020 for use in appendix C1. AHRI and
National Refrigeration commented that
they disagreed with DOE aligning
appendix C1 with AHRI 1250–2020 and
requested further clarification on the
proposal. (AHRI, No. 30 at p. 7; National
Refrigeration, No. 39 at p. 2) Neither
AHRI nor National Refrigeration
provided detail about what specifically
they disagreed with, or which aspects of
DOE’s proposal required further
clarification.
In response to the April 2022 NOPR,
HTPG requested details on the changes
in the new appendix C1 that may
impact the determination of AWEF for
unit coolers and variable-capacity
systems. (HTPG, No. 32 at p. 2) These
topics are discussed in detail in sections
III.G.7 and III.G.11 of this document,
respectively.
As discussed in this section and in
more detail in section III.G, DOE has
concluded that the changes in AHRI
1250–2020 improve the
representativeness of the walk-in
refrigeration systems test procedure.
Therefore, DOE is incorporating AHRI
1250–2020, ASHRAE 37–2009,
ASHRAE 16–2016 for use in appendix
C1 as proposed in the April 2022 NOPR.
c. Additional Amendments
AHRI 1250–2020 includes additional
amendments that are inconsistent with
AHRI 1250–2009 but are either not
referenced in the DOE test procedure or
serve to make aspects of the test
procedure more explicit or clear. None
of these changes impact measured
AWEF. These additional amendments
are discussed in the paragraphs below.
AHRI 1250–2020 added exclusions for
liquid-cooled condensing systems in
section 2.2.4 and excludes systems that
use carbon dioxide, glycol, or ammonia
as refrigerants in section 2.2.5. As
mentioned previously, DOE is not
incorporating section 2 of AHRI 1250–
2020 into appendix C1.
AHRI 1250–2020 includes an updated
list of references and the applicable
versions of certain test standards in
appendix A, ‘‘References—Normative.’’
DOE does not expect these changes to
impact measured AWEF apart from
ways discussed in section III.G. AHRI
1250–2020 added specifications for
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refrigerant temperature measurement
locations for unit coolers tested alone,
matched pairs, and dedicated
condensing systems tested alone in
sections C3.1.3.1, C3.1.3.2, and C3.1.3.3.
DOE has determined that these
specifications will not affect measured
AWEF.
AHRI 1250–2020 revised section
C7.5.1 to provide more detailed
instructions for calculating system
capacity beginning with measured
temperatures and pressures instead of
calculated enthalpies, which is what
was done in AHRI 1250–2009. Section
C7.5.1 also includes the determination
of capacity from enthalpy calculation
results. The addition of these sections
provides clarity and further instruction
but does not affect measured AWEF.
AHRI 1250–2009 included section
C12, ‘‘Method of Testing Condensing
Units for Walk-in Cooler and Freezer
Systems for Use in Mix-Match System
Ratings,’’ which referenced ASHRAE
23.1–2010. AHRI 1250–2020 now
provides specific methods for testing
dedicated condensing units tested
alone. DOE has determined that the test
procedure incorporated into AHRI
1250–2020 is the same as that in
ASHRAE 23.1–2010 and therefore does
not impact measured AWEF.
Section C13 of AHRI 1250–2009,
‘‘Method of Testing Unit Coolers for
Walk-in Cooler and Freezer Systems for
Use in Mix-Match System Ratings,’’
referenced AHRI 420–2008. AHRI 1250–
2020 no longer references AHRI 420–
2008 and instead outlines a method for
unit coolers tested alone. DOE has
determined that the test procedure
incorporated into AHRI 1250–2020 is
the same as that in ASHRAE AHRI 420–
2008 and therefore does not impact
measured AWEF. As a result, DOE is not
incorporating by reference AHRI 420–
2008 in new appendix C1.
C. Amendments to Appendix A for
Doors
Appendix A provides test procedures
for measuring walk-in envelope
component energy consumption.
Specifically, appendix A provides the
test procedures to determine the Ufactor, conduction load, and energy use
of walk-in display panels and to
determine the energy use of walk-in
display doors and non-display doors
(see section III.D for discussion of
display panels).
In the April 2022 NOPR, DOE
proposed several changes to appendix A
specific to display doors and nondisplay doors. 87 FR 23920, 23936–
23943. DOE determined that these
changes would improve test
representativeness and repeatability.
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DOE stated in the April 2022 NOPR that
it did not expect the changes it
proposed to have a substantive impact
on measured energy consumption
calculations for display doors or nondisplay doors, except in the case of
testing doors with motors.
The following sections describe the
modifications that DOE proposed to
appendix A with respect to walk-in
display and non-display doors.
1. Reference to NFRC 102–2020 in Place
of NFRC 100–2010 and Alternative
Efficiency Determination Methods for
Doors
a. NFRC 102–2020 in Place of NFRC
100–2010
Appendix A references NFRC 100–
2010 as the method for determining the
U-factor of doors and display panels.
NFRC 100–2010 allows for
computational determination of U-factor
by simulating U-factor using Lawrence
Berkeley National Lab’s (LBNL)
WINDOW and THERM software,
provided that the simulated value for
the baseline product in a product line is
validated with a physical test of that
baseline product and the simulated
value is within the accepted agreement
with the physical test value as specified
in section 4.7.1 of NFRC 100–2010.27
As discussed in the April 2022 NOPR,
DOE is aware there has been limited
success using the computational method
in NFRC 100–2010 to simulate U-factors
of non-display doors. 87 FR 23920,
23936–23937. Thus, DOE proposed to
remove reference to NFRC 100–2010
(i.e., the computational method) and
instead reference NFRC 102–2020 (i.e.,
the physical test method) for
determining U-factor. Id. Consistent
with that proposal, and with
stakeholder concerns regarding test
burden given the highly customizable
nature of the walk-in door market, DOE
also proposed to allow use of alternative
efficiency determination methods
(AEDMs) to determine the represented
value of energy consumption of walk-in
doors at 10 CFR 429.53(a)(3). 87 FR
23920, 23972.
In response, Bally stated that it looks
forward to using AEDMs to rate its
walk-in doors. (Bally, No. 40 at p. 5)
RSG also agreed with the proposal to
allow for AEDMs. (RSG, No. 41 at p. 2)
27 Section 4.7.1 of NFRC 100–2010 requires that
the accepted difference between the tested U-factor
and the simulated U-factor be (a) 0.03 Btu/(h-ft2-°F)
for simulated U-factors that are 0.3 Btu/(h-ft2-°F) or
less, or (b) 10 percent of the simulated U-factor for
simulated U-factors greater than 0.3 Btu/(h-ft2-°F).
This agreement must match for the baseline product
in a product line. Per NFRC 100, the baseline
product is the individual product selected for
validation; it is not synonymous with ‘‘basic
model’’ as defined in 10 CFR 431.302.
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Hussmann noted that, although it is
‘‘not pleased’’ with the current NFRC
100–2010 test method, it does not
support use of an AEDM because it
believes rating with an AEDM creates an
opportunity for ‘‘approved noncompliance.’’ (Hussmann, No. 34 at pp.
3–4)
DOE acknowledges Hussmann’s
concern but notes that rating a basic
model with an AEDM does not excuse
a manufacturer from complying with the
relevant energy conservation standards.
DOE has several requirements
pertaining to AEDM records retention;
the ability to provide analyses, conduct
simulations, or conduct certification
testing of basic models rated with the
AEDM at DOE’s request; and
verification testing of an AEDM by DOE.
These requirements can be found in 10
CFR 429.70(f)(3) through (5). DOE
enforces all these requirements.
DOE notes that despite the limited
success historically with using the
computational method in NFRC 100–
2010, to the extent that manufacturers
have successfully used the simulation
method in NFRC 100–2010 to produce
accurate results, such results would be
acceptable as an AEDM. AEDMs and the
specific provisions DOE is adopting
pertaining to AEDMs for doors are
explained and discussed in the
following section.
b. Alternative Efficiency Determination
Methods for Doors
Pursuant to the requirements of 10
CFR 429.70, DOE may permit use of an
AEDM in lieu of testing equipment for
which testing burden may be
considerable and for which that
equipment’s energy efficiency
performance may be well predicted by
such alternative methods. Although
specific requirements vary by product or
equipment, use of an AEDM entails
development of a mathematical model
that estimates energy efficiency or
energy consumption characteristics of
the basic model, as would be measured
by the applicable DOE test procedure.
The AEDM must be based on
engineering or statistical analysis,
computer simulation or modeling, or
other analytic evaluation of performance
data. A manufacturer must perform
validation of an AEDM by
demonstrating that the performance, as
predicted by the AEDM, agrees with the
performance as measured by actual
testing in accordance with the
applicable DOE test procedure. The
validation procedure and requirements,
including the statistical tolerance,
number of basic models, and number of
units tested vary by product or
equipment.
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Once developed and validated, an
AEDM may be used to rate and certify
the performance of untested basic
models in lieu of physical testing. Use
of an AEDM for any basic model is
always at the option of the
manufacturer. One potential advantage
of AEDM use is that it may free a
manufacturer from the burden of
physical testing. One potential risk is
that the AEDM may not perfectly
predict performance, and the
manufacturer could be found
responsible for having an invalid rating
for the equipment in question or for
having distributed a noncompliant basic
model. The manufacturer, by using an
AEDM, bears the responsibility and risk
of the validity of the ratings.
For walk-ins, DOE currently permits
the use of AEDMs for refrigeration
systems only. 10 CFR 429.70(f). As
discussed previously, DOE proposed to
allow the use of AEDMs for rating walkin doors in the April 2022 NOPR. 87 FR
23920, 23972. Concurrent with this
proposal, DOE proposed a number of
provisions specific to the validation and
use of an AEDM. First, DOE proposed to
include walk-in door validation classes
at 10 CFR 429.70(f)(2)(iv) and to require
that two basic models per validation
class be tested using the proposed test
procedure in appendix A, which is
consistent with the number of basic
models required to be tested per
validation class for walk-in refrigeration
systems. Id.
Second, DOE proposed to include a 5
percent individual model tolerance,
which aligns with the individual model
tolerance applicable to walk-in
refrigeration systems, to validate the
measured energy consumption result of
an AEDM with the appendix A test
result at 10 CFR 429.70(f)(2)(ii). Id. The
individual model tolerance is used to
validate the AEDM. This means that
when validating the AEDM for use, the
predicted daily energy consumption for
each model calculated by applying the
AEDM may not be more than 5 percent
less than the daily energy consumption
determined from the corresponding test
of the model.
DOE also proposed that an AEDM for
doors can only simulate or model
characteristics of the door that are
required to be tested by the DOE test
procedure—i.e., for the doors test
procedure, the AEDM would be used to
simulate or model the U-factor, which is
the only part of the appendix A test
procedure that is not a calculation. The
AEDM cannot be used to simulate or
model the energy consumption due to
conduction thermal load, or the direct
and indirect electrical energy
consumption of electricity-consuming
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devices sited on the door—those must
be calculated using the appendix A test
procedure. However, when validating
the AEDM, the comparison between a
door that has been physically tested
versus a door that has been modeled or
simulated must be done using the
complete metric (i.e., total daily energy
consumption). In other words, the
AEDM can only be used to determine
the U-factor, but the total daily energy
consumption using an AEDM must be
carried out using the calculations in
appendix A for the energy consumption
due to conduction thermal load, and the
direct and indirect electrical energy
consumption. Then, the validation of an
AEDM would compare the energy
consumption calculated using a
simulated U-factor with the energy
consumption calculated using a tested
U-factor.
Lastly, DOE proposed to include a 5
percent tolerance applicable to the
maximum daily energy consumption
metric for AEDM verification testing
conducted by DOE at 10 CFR
429.70(f)(5)(vi), which aligns with the
tolerance applicable to AWEF of walkin refrigeration systems. Id. DOE may
randomly select and test a single unit of
a basic model to assess whether a basic
model is in compliance with the
applicable energy conservation
standards pursuant to 10 CFR 429.104,
which extends to all DOE covered
products and equipment, including
those certified using an AEDM. As part
of the AEDM requirements, DOE may
use the test data from an assessment test
for a given model to verify the certified
rating determined by an AEDM. This is
called verification testing. See 10 CFR
429.70(f)(5). For doors using an energy
consumption metric, the result from a
DOE verification test must be less than
or equal to the certified rating
multiplied by (1 plus the applicable
tolerance); i.e., the DOE verification test
result must be less than or equal to 105
percent of the certified rating.
In the April 2022 NOPR, DOE
requested comment on the specific
proposals pertaining to the validation
and use of AEDMs for doors. Id. RSG
agreed with the proposals. (RSG, No. 41
at p. 2)
Anthony disagreed with DOE
removing the reference to NFRC 100–
2010 for NFRC 102–2020 and allowing
AEDMs because it believes an AEDM
would require more testing and result in
an increased financial and physical
burden on manufacturers without
achieving an additional energy benefit.
(Anthony, No. 31 at pp. 3, 8–9)
Additionally, Anthony stated that if
NFRC 100–2010 is able to be used as an
AEDM, the application of the 5 percent
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tolerance on the energy consumption
metric, Edd, would conflict with the
NFRC 100–2010 standard without
achieving an additional energy benefit.
Id. AHRI commented that the AEDM
strategy with respect to U-factor is
unclear and requested clarification of
what the proposed 5 percent model
tolerance applies to. (AHRI, No. 30 at p.
11)
DOE is clarifying that to use an
AEDM, the manufacturer must first
validate the AEDM. To validate the
AEDM, the manufacturer must select at
least the minimum number of basic
models for each validation class
(specified in table 1 to 10 CFR
429.70(f)(2)(iv)(A)) and physically test a
single unit of each basic model. Thus,
for a single validation class, where DOE
proposed two basic models be tested per
validation class, only two physical tests
would be required, although more
testing may be conducted at the
manufacturer’s discretion. The
manufacturer would be required to
conduct the physical U-factor tests
according to NFRC 102–2020 referenced
by appendix A and carry out the energy
consumption calculations as done in
appendix A. For the AEDM, the
manufacturer would model or simulate
the U-factor using a method of their
choice, and then carry out the energy
consumption calculations as done for
the physical test, only deviating by
using the simulated U-factor in the
calculations. All other parts of the
energy consumption calculations shall
be done according to appendix A and
may not be modeled. To validate the
AEDM, the energy consumption output
using the physical test must be
compared with the energy consumption
output using the AEDM for each basic
model used for validation. If the output
using the AEDM is lower than the
physical test output by more than the
individual model tolerance (i.e., 5
percent), then the AEDM is not valid. If
the output using the AEDM is greater
than or equal to 95 percent of the output
using physical testing and meets the
standard for at least two basic models,
then the AEDM has been validated for
that validation class.
To illustrate the minimum number of
physical tests required, consider an
example of a display door manufacturer
that produces models in two validation
classes: medium-temperature and lowtemperature. This manufacturer would
need to, at a minimum, physically test
the U-factor and calculate the energy
consumption of two basic models per
validation class, thus requiring a total of
four physical tests: two for the mediumtemperature display door validation
class and two for the low-temperature
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display door validation class. The
manufacturer would use the U-factor
test results to calculate the total daily
energy consumption each door. Then,
the manufacturer would use their
AEDM to model or simulate the U-factor
of each door and calculate each door’s
total daily energy consumption. Each
basic model’s simulated and tested total
daily energy consumption results would
be compared using the tolerance of 5
percent in order to validate the AEDM.
DOE stresses that this 5 percent
tolerance used to validate the AEDM
would only apply to the comparison of
tested and simulated energy
consumption for the minimum number
of models physically tested for
validation of the AEDM. If the AEDM is
validated, the manufacturer could then
use the AEDM to rate the remainder of
the basic models it manufacturers in
those validation classes. The 5 percent
tolerance would not be used for any
models simulated without a physical
test because the AEDM was validated
and thus no physical test would be
further required.
DOE emphasizes that allowing use of
an AEDM would provide manufacturers
with the flexibility to use an alternative
method (i.e., besides NFRC 100–2010)
that yields the best agreement with a
physical test for their doors.
Additionally, DOE notes that the change
in test burden associated with the use of
an AEDM is dependent on a
manufacturer’s product offerings. If a
manufacturer does not have success
with NFRC 100–2010 and is currently
required to physically test all basic
models, the AEDM option may reduce
the test burden by requiring only two
basic models per validation class to be
tested. DOE is aware there has been
limited success using the computational
method in NFRC 100–2010 to simulate
U-factors of non-display doors.
Therefore, DOE expects a reduction of
test burden across the industry since
allowing AEDMs generally provides
manufacturers, particularly those that
manufacture non-display doors, the
flexibility to use an alternate method
that works best for them and meets the
AEDM criteria established by DOE.
However, if a manufacturer currently
has success using NFRC 100–2010, there
could be an increase in test burden, but
only if the manufacturer currently
validates the use of the simulation
method with less than two basic models
per validation class. Test burden and
costs are discussed further in section
III.K.1 of this document. The inclusion
of AEDM provisions would enable
manufacturers to continue using NFRC
100–2010, provided that manufacturers
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meet the AEDM requirements in 10 CFR
429.53 and 429.70(f). Therefore, DOE is
removing reference to NFRC 100–2010
from its test procedure and is instead
referencing NFRC 102–2020 and
adopting provisions that allow
manufacturers to use an AEDM, as
proposed in the April 2022 NOPR.
c. Exceptions to the Industry Test
Method for Determining U-Factor
Section 5.3 of appendix A references
NFRC 100–2010 for determining Ufactor, and section 5.3(a) of appendix A
specifies four exceptions to that
industry standard. The first exception
implements a tolerance on the surface
heat transfer coefficients (no such
tolerance is specified in NFRC 100–
2010); specifically, that the average
surface heat transfer coefficients during
a test must be within ± 5 percent of the
values specified through NFRC 100–
2010 in ASTM C1199. The second and
third exceptions modify the cold and
warm-side conditions from the standard
conditions prescribed in NFRC 100–
2010. The fourth exception specifies the
direct solar irradiance be 0 Btu/(h-ft2).
Sections 6.2.3 and 6.2.4 of ASTM
C1199 specify the standardized heat
transfer coefficients and their tolerances
as part of the procedure to set the
surface heat transfer conditions of the
test facility using the Calibration
Transfer Standard (‘‘CTS’’) test. The
warm-side surface heat transfer
coefficient must be within ± 5 percent
of the standardized warm-side value of
1.36 Btu/(h-ft2-°F), and the cold-side
surface heat transfer coefficient must be
within ± 10 percent of the standardized
cold-side value of 5.3 Btu/(h-ft2-°F)
during the CTS test (ASTM C1199,
sections 6.2.3 and 6.2.4). ASTM C1199
does not require that the measured
surface heat transfer coefficients match
or be within a certain tolerance of
standardized values during the official
sample test—although test facility
operational (e.g., cold-side fan settings)
conditions would remain identical to
those set during the CTS test. ASTM
C1199 also does not require
measurement of the warm-side surface
temperature of the door. Rather, this
value is calculated based on the
radiative and convective heat flows
from the test specimen’s surface to the
surroundings, which are driven by
values determined from the calibration
of the hot box using the CTS test (e.g.,
the convection coefficient). See ASTM
C1199, section 9.2.1.
As discussed in the April 2022 NOPR,
DOE has found that obtaining the
standardized heat transfer values within
the ± 5 percent tolerance specified in
section 5.3(a)(1) of appendix A on the
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warm side and cold side may not be
achievable depending on the thermal
transmittance through the door. 87 FR
23920, 23937. In the April 2022 NOPR,
DOE proposed to remove the exceptions
specified in section 5.3(a)(1) of
appendix A regarding the surface heat
transfer coefficients and the tolerances
on them during testing.
DOE did not receive any comments on
its proposal to remove the exceptions
specified in section 5.3(a)(1) of
appendix A.
For the reasons discussed in the
preceding paragraphs and the April
2022 NOPR, DOE is removing the
exceptions listed in section 5.3(a)(1) of
appendix A regarding the surface heat
transfer coefficients and the tolerances
on them during testing. 87 FR 23920,
23937–23938. By removing these
exceptions, the requirements pertaining
to the surface heat transfer coefficients
would apply as they are specified in the
referenced industry standards.
Relatedly, Anthony commented on
the specific values used to define the
surface heat transfer coefficients.
Specifically, Anthony commented that
it disagrees with the current surface heat
transfer coefficient applied to the cold
side during testing and simulation of Ufactors for display doors. (Anthony, No.
31 at pp. 4–5) Anthony presented data
from field testing at several different
public locations showing that the actual
measured wind speed is on average 84
percent less than specified in NFRC
102–2020 and NFRC 100–2010, as well
as a measured wind speed from their
test cell showing an average of 1.1 miles
per hour (‘‘mph’’). Anthony
recommended that DOE adopt a coldside heat transfer coefficient
corresponding to a conservative wind
speed value of 5 mph. Id.
DOE notes that deviating from the
existing surface heat transfer
coefficients would require test labs to
change their test chamber calibration
procedures and would require
manufacturers to retest and rerate all
envelope components subject to the
energy consumption test procedure in
appendix A. DOE has evaluated the data
and information provided by Anthony
but is unable to establish at this time
whether such changes to the heat
transfer coefficient would be nationally
representative, nor the extent to which
any such improvement in
representativeness of the test result
would outweigh the test burden
associated with changing the heat
transfer coefficient value. DOE has
therefore determined it is not
appropriate to amend the heat transfer
coefficients in this final rule.
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Additionally, section 5.3(a)(1) of
appendix A currently specifies a direct
solar irradiance 28 of 0 Btu/h-ft2.
Consistent with DOE’s removal of its
reference to NFRC 100–2010, DOE is
removing the requirement of direct solar
irradiance of 0 Btu/h-ft2 in section
5.3(a)(4) of appendix A. DOE received
no comment on solar irradiance in
response to the April 2022 NOPR and
notes that the removal of this
requirement would not affect measured
values. 87 FR 23920, 23938.
2. Additional Definitions
a. Surface Area for Determining
Compliance With Standards
Surface area of a door is used in two
ways in the regulations at subpart R of
10 CFR431: (1) to convert the tested Ufactor of the door into a conduction load
as part of the energy consumption test
procedure, and (2) to determine
compliance with the maximum energy
consumption standards. As currently
defined in section 3.4 of appendix A,
surface area means the area of the
surface of the walk-in component that
would be external to the walk-in cooler
or walk-in freezer as appropriate. The
definition does not provide detail on
how to determine the boundaries of the
walk-in door from which height and
width are determined to calculate
surface area. Additionally, the
definition does not specify if these
measurements are to be strictly in-plane
with the surface of the wall or panel that
the walk-in door would be affixed to, or
if troughs and other design features on
the exterior surface of the walk-in door
should be included in the measured
surface area.
In the April 2022 NOPR, DOE
proposed that the surface area bounds of
both display doors and non-display
doors be the outer edge of the frame. 87
FR 23920, 23939. DOE proposed to
change the term from ‘‘surface area’’ to
‘‘door surface area,’’ and to define the
term as meaning the product of the
height and width of a walk-in door
measured external to the walk-in. Id.
Under this definition, the height and
width dimensions would be
perpendicular to each other and parallel
to the wall or panel of the walk-in to
which the door is affixed, the height and
width measurements would extend to
the edge of the frame and frame flange
(as applicable) to which the door leaf is
affixed, and the surface area of a display
door and non-display door would be
represented as Add and And, respectively.
28 Solar irradiance is the power per unit area
received from the sun in the form of
electromagnetic radiation.
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In addition, DOE proposed to move
the defined term from the test procedure
in appendix A to the definition section
in 10 CFR 431.302 with the other
definitions that are broadly applicable
to subpart R. Id. DOE proposed this
move because, as revised and in light of
the following section III.C.2.b of this
document, this term would no longer be
used to convert the tested U-factor of the
door into a conduction load as part of
the energy consumption test procedure
and is only relevant for determining
compliance with the energy
conservation standards. Id.
Anthony agreed with the proposed
revision of using the external frame
dimensions, which includes the flange,
for determining Add and for determining
the maximum energy consumption
standard. (Anthony, No. 31 at p. 5)
Bally suggested that the surface area
definition should include electrical
conduit and pressure relief vents, not
pieces of the door with low
conductivity. (Bally, No. 40 at pp. 1–2)
Bally also commented that it disagrees
with DOE’s discussion in the April 2022
NOPR that if the surface area of a door
is measured without the frame, then it
should be considered a panel. (Id.)
Senneca stated that the outside
dimensions of the frame should not be
included in the surface area
measurement because the frame mounts
directly to the insulated panel and,
therefore, the backside of the frame is
not exposed directly to the cold-side
temperature. (Senneca, No. 26 at p. 2)
Additionally, Senneca described that a
door with a longer track would require
a longer frame and therefore would have
a larger surface area; however, it stated
that the larger frame would have no
bearing on the energy consumption
because, as mentioned, the backside of
the frame is not exposed directly to the
cold-side temperature. (Id.)
Senneca also stated that with the
proposal for the door frame to be
included in the surface area, it believes
there is ambiguity in measuring sliding
doors that have a track extending past
the door frame. (Id.) DOE has
considered Senneca’s comment specific
to sliding doors and acknowledges that
the track of a horizontal sliding door
may extend significantly beyond the
width of the door leaf and door frame
or casings and attach to the panels
adjacent to the door, which would result
in a significant increase in ‘‘door surface
area’’ if the track width were to be
included in the area measurement.
Therefore, DOE has concluded that the
portion of the track that extends beyond
the external width (for a horizontal
sliding door) or external height (for a
vertical sliding door) of the door leaf or
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leaves and its frame or casings should
be excluded from the surface area
measurement used to determine
compliance with the standards. DOE
notes that given the equipment it is
aware of on the market, this additional
instruction will likely only impact the
bounds of sliding non-display doors.
DOE notes that sliding display doors
typically have tracks that are integrated
completely into the frame of the entire
door system, thus the entire track is
expected to be included in the
determination of surface area.
DOE has considered stakeholder
opposition to including the frame in the
door surface area measurement but has
determined that the definition of ‘‘door’’
includes the frame for consistent
comparison across door products
offered. DOE recognizes that nondisplay doors may have variations in the
frames used, where some look similar to
panels but tend to have electrical
components wired through them, while
others look more like casings used in
replacement installations. DOE also
recognizes that non-display doors may
have variations in the installation of
doors, where parts of the door frame
may or may not be in direct contact with
the cold side of the walk-in. However,
DOE intends to consistently evaluate
different products and sees a need to
have consistent instructions on
determining the bounds of surface area
for all walk-in doors. DOE has
determined that all parts of the door that
impact the operation of the door shall be
included in the determination of the
surface area, with the exception of
extended track area for sliding doors as
discussed previously. Therefore, the
bounds of the ‘‘door surface area’’
dimensions also include the frame.
As proposed in the April 2022 NOPR,
in this final rule, DOE is defining ‘‘door
surface area’’ as the product of the
height and width of a walk-in door
measured external to the walk-in. The
height and width dimensions shall be
perpendicular to each other and parallel
to the wall or panel of the walk-in to
which the door is affixed. The height
and width measurements shall extend to
the edge of the frame and frame flange
(as applicable) to which the door is
affixed. For sliding doors, the height
and width measurements shall include
the track; however, the width (for
horizontal sliding doors) or the height
(for vertical sliding doors) shall be
truncated to the external width or height
of the door leaf or leaves and its frame
or casings. The surface area of a display
door is represented as Add, and the
surface area of a non-display door is
represented as And.
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b. Surface Area for Determining UFactor
As stated previously, appendix A
currently references NFRC 100–2010,
which in turn references NFRC 102 for
the determination of U-factor through a
physical test. When conducting physical
testing, the U-factor (Us) is calculated
using projected surface area (As) and
then converted to the final standardized
U-factor (UST). See ASTM C1199,
sections 8.1.3 and 9.2.7, as referenced
through NFRC 102. Projected surface
area (As) is defined as ‘‘the projected
area of test specimen (same as test
specimen aperture in surround panel).’’
See ASTM C1199, section 3.3, as
referenced through NFRC 102.
Currently, equations 4–19 and 4–28 of
appendix A specify that surface area of
display doors (Add) and non-display
doors (And), respectively, are used to
convert a door’s U-factor into a
conduction load. This conduction load
represents the amount of heat that is
transferred from the exterior to the
interior of the walk-in.
As discussed in section III.C.2.a, DOE
is amending the definitions of And and
Add to be specific to the exterior
dimensions of the door, including the
frame and frame flange as appropriate.
Defining the bounds of the door through
this definition is inconsistent with the
defined area (As) used to calculate Ufactor in NFRC 102–2020.
In the April 2022 NOPR, DOE
proposed to specify that the projected
area of the test specimen, As, as defined
in ASTM C1199, or the area used to
determine U-factor is the area used for
converting the standardized tested Ufactor, UST, into a conduction load in
appendix A. 87 FR 23920, 23940. DOE
recognizes that this may not change
ratings for some doors, where As is
equivalent to And or Add, but it may
result in slightly lower ratings of energy
consumption for other doors, where As
is less than And or Add. DOE expects that
since this proposed detail would either
result in a reduced measured energy
consumption or have no impact, there
will likely be no need for manufacturers
to retest or rerate. Additional details on
how this detail impacts retesting and
rerating are further discussed in section
III.K.1 of this document.
Anthony commented that it agrees
with the proposed revision to use the
area of the test specimen, As, to
calculate the conduction load.
(Anthony, No. 31 at p. 6) Bally
reiterated comments from AHRI,
Hussmann, and Imperial Brown in
response to the June 2021 RFI which
suggested they did not see a distinction
that warranted changing the definition.
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(Bally, No. 40 at p. 1) See summary of
these comments at 87 FR 23920, 23939.
DOE reiterates that the door surface
area defined in section III.C.2.a differs
from the surface area used to calculate
U-factor in NFRC 102–2020. Thus,
despite stakeholder comments, DOE
sees a need to resolve this discrepancy.
Otherwise, the conduction load
determined from the physical U-factor
test may inflate the actual conduction
load.
In the April 2022 NOPR, DOE also
proposed to specify in appendix A that
the physical U-factor test should
include all components of the door that
aid in the operation of the door,
including the frame, rather than just the
door leaf, to improve consistency in
application of the test procedure across
all walk-in doors. 87 FR 23920, 23940.
Bally commented that it does not
believe the frame of the door should be
included in the U-factor test and
suggested that including the frame in
the U-factor test was minimal in
comparison to the electrical
components. (Bally, No. 40 at pp. 2–3)
As stated in the April 2022 NOPR,
DOE’s testing of non-display doors has
demonstrated that including the frame
in the U-factor test has a measurable
impact on the thermal performance of
the door assembly relative to the
increase in the total area, and so DOE is
adopting the specification that the
physical U-factor test should include
the door frame.
3. Electrical Door Components
Sections 4.4.2 and 4.5.2 of appendix
A currently include provisions for
calculating the direct energy
consumption of electrical components
of display doors and non-display doors,
respectively. Electrical components
associated with doors could include, for
example, heater wire (for anti-sweat or
anti-freeze applications), lights
(including display door lighting
systems), control system units, or
sensors. For each electricity consuming
component, the calculation of energy
consumption is based on the
component’s ‘‘rated power’’ rather than
a measurement of its power draw.
Section 3.5 of appendix A defines
‘‘rated power’’ as the electricity
consuming device’s power as specified
(1) on the device’s nameplate or (2) on
the device’s product data sheet if the
device does not have a nameplate or
such nameplate does not list the
device’s power.
As discussed in the April 2022 NOPR,
DOE has observed issues that make
calculating a door’s total energy
consumption a challenge. 87 FR 23920,
23940. These issues include using a
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single nameplate for all door electrical
components rather than individual
nameplates for all electricity-consuming
devices, specification of voltage and
amperage rather than wattage on the
nameplate, and no specification of
whether the nameplate represents the
maximum or steady-state operating
conditions. DOE is aware that
measuring direct power consumption of
each electrical component could
alleviate some of these issues. In
response to the April 2022 NOPR, the
Efficiency Advocates stated that they
support an option for direct
measurement of door component
electrical power in the test procedure
(Efficiency Advocates, No. 37 at p. 4).
DOE acknowledges the comment but
has concluded that additional
investigation is needed to develop a test
procedure for such measurements.
Therefore, DOE is not adopting
provisions requiring measurement of
power consumption of each electrical
door component in appendix A.
Furthermore, DOE has observed that
some manufacturers may be certifying
door motor power as the output power
rating of the motor, rather than the input
power of the motor. Thus, DOE
proposed in the April 2022 NOPR to
specify in appendix A that the rated
power of each electrical component,
Prated,u,t, would be the rated input power
of each component because the input
power represents power consumption.
The Efficiency Advocates also
supported the clarification that the
certified door motor power should be
the input power. Id.
Additionally, DOE has observed
through testing that the measured power
of some walk-in door electrical
components exceeds either the certified
or nameplate power values of these
electrical components. In the April 2022
NOPR, DOE proposed that for the
purposes of enforcement testing, in 10
CFR 429.134(q), DOE may validate the
certified or nameplate power values of
an electrical component by measuring
the power when the device is energized
using a power supply that provides
power within the allowable voltage
range listed on the nameplate. If the
measured input power is more than 10
percent higher than the power listed on
the nameplate or the rated input power
in a manufacturer’s certification, then
the measured input power would be
used in the energy consumption
calculation. For electrical components
with controls, the maximum input
wattage observed while energizing the
device and activating the control would
be considered the measured input
power. Anthony agreed with the
proposal to use nameplate values for
determining energy consumption unless
physical testing results in a power value
that exceeds what is depicted on the
nameplate. (Anthony, No. 31 at p. 6)
Bally stated that adjusting nameplate
values based on measurement results
requires door manufacturers to be
responsible for the quality assurance of
their vendors. (Bally, No. 40 at p. 3) In
response, DOE notes that the door
manufacturer is ultimately responsible
for certifying that the walk-in door,
when outfitted with all necessary
components, meets the applicable DOE
energy conservation standards.
Given DOE’s observations during
testing, DOE sees a need to provide a
way to calculate energy consumption
using a measured value of electrical
component power. DOE recognizes that
there may be minor variations in
measured power as compared to the
rated power and has determined that a
tolerance of 10 percent accounts for
such variation. DOE is adopting this
provision at 10 CFR 429.134(q)(4) only
for the purposes of enforcement testing
to aid the Department in determining
non-compliance with energy
conservation standards.
4. Percent Time Off Values
The current test procedure assigns
percent time off (‘‘PTO’’) values to
various walk-in door components to
reflect the hours in a day that an
electricity-consuming device operates at
its full rated or certified power. PTO
values are not incorporated in the rated
or certified power of an electricityconsuming device. Table III.2 lists the
PTO values in the current DOE test
procedure for walk-in door components.
TABLE III.2—ASSIGNED PTO VALUES FOR WALK-IN DOOR COMPONENTS
Percent time
Off (PTO)
(%)
Component type
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Lights without timers, control system, or other demand-based control ..............................................................................................
Lights with timers, control system, or other demand-based control ...................................................................................................
Anti-sweat heaters without timers, control system, or other demand-based control ..........................................................................
Anti-sweat heaters on walk-in cooler doors with timers, control system, or other demand-based control ........................................
Anti-sweat heaters on walk-in freezer doors with timers, control system, or other demand-based control .......................................
All other electricity-consuming devices without timers, control system, or other auto-shut-off system .............................................
All other electricity-consuming devices for which it can be demonstrated that the device is controlled by a preinstalled timer,
control system, or auto-shut-off system ...........................................................................................................................................
As mentioned in the April 2022
NOPR, DOE has granted waivers to
several door manufacturers with
motorized door openers, allowing the
use of a different PTO for motors.29 87
FR 23920, 23941. DOE proposed a single
PTO for use with door motors to create
consistency in the test procedure among
doors with motors. 87 FR 23920, 23941–
23942. DOE calculated an average PTO
value based on the information in the
29 See HH Technologies, 83 FR 53457; Jamison
Door Company, 83 FR 53460; Senneca Holdings, 86
FR 75; Hercules, 86 FR 17801.
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waivers to determine a single
representative PTO value. Considering
the waivers and its calculations, DOE
proposed to adopt a door motor PTO
value of 97 percent for all walk-in doors
with motors. Id. Senneca and the
Efficiency Advocates agreed with the
proposed PTO. (Senneca, No. 26 at p. 2;
Efficiency Advocates, No. 37 at p. 2)
Bally suggested that the power
consumption of the motor be completely
removed from the energy consumption
calculation, but ultimately supported
the proposed PTO value. (Bally, No. 40
at p. 3) DOE has determined that motor
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50
0
75
50
0
25
power consumption contributes to
direct and total energy consumption of
the door and aids in the operation of the
door. Therefore, the motor power
should be included in the determination
of energy consumption. Additionally,
pursuant to its waiver regulations, as
soon as practicable after the granting of
any waiver, DOE will publish in the
Federal Register a notice of proposed
rulemaking to amend its regulations to
eliminate any need for the continuation
of such waiver. 10 CFR 431.401(l). For
the reasons stated above, DOE is
adopting the PTO value of 97 percent
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for door motors in appendix A. DOE
notes that the adoption of this PTO
value would not require retesting or
recertification because calculated daily
energy consumption will be equal to or
lower than currently certified values.
New testing would only be required if
the manufacturer wishes to make claims
using the new, more efficient rating.
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5. Energy Efficiency Ratio Values
As discussed in the April 2022 NOPR,
the energy efficiency ratio (‘‘EER’’)
values used in appendix A differ from
the EER values in appendix C. 87 FR
23920, 23942. The values in appendix A
are used to calculate the daily energy
consumption associated with heat loss
through a walk-in door, and the values
in appendix C correspond to adjusted
dew point temperature when testing
refrigeration systems of walk-in unit
coolers alone. In the July 2021 RFI, DOE
requested comment on the difference in
EER values used in appendices A and C
and based on stakeholder feedback, DOE
concluded in the April 2022 NOPR that
there is no advantage to harmonizing
the two values. Id. As discussed in the
April 2022 NOPR, an envelope
component manufacturer cannot control
what refrigeration equipment is
installed and the EER values are
intended to provide a nominal means of
comparison rather than reflect an actual
walk-in installation. Additionally, the
difference between the EER values used
in appendix A for doors and those used
in appendix C for unit coolers is seven
percent for coolers and five percent for
freezers; however, changing the EER
values would require manufacturers to
retest and rerate energy consumption
without necessarily providing a more
representative test procedure. Id.
Therefore, in the April 2022 NOPR, DOE
did not propose to harmonize the EER
values between appendices A and C.
In response to the April 2022 NOPR,
Anthony suggested that DOE adopt the
EER values specified in AHRI 1250 to
align all components of a WICF and
stated that the modification of EER
values would not require additional
testing, as these values are only used in
the mathematical energy calculations.
(Anthony, No. 31 at pp. 6–7) DOE notes
that Anthony’s suggested approach
would require recalculation and
recertification of every basic model and
would do so without necessarily
providing a more representative test
procedure. As such, DOE has
determined that changing the reference
EER values in either appendix A or C
would be unduly burdensome.
Therefore, DOE is not harmonizing the
EER values in appendices A and C.
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6. Air Infiltration Reduction
As discussed in the April 2022 NOPR,
EPCA includes prescriptive
requirements for doors used in walk-in
applications intended to reduce air
infiltration. 87 FR 23902, 23943.
Specifically, walk-ins must have (A)
automatic door closers that firmly close
all walk-in doors that have been closed
to within 1 inch of full closure
(excluding doors wider than 3 feet 9
inches or taller than 7 feet), and (B) strip
doors, spring-hinged doors, or other
method of minimizing infiltration when
doors are open. (42 U.S.C. 6313(f)(1)(A)–
(B)) DOE previously proposed methods
for determining the thermal energy
leakage due to steady-state infiltration
through the seals of a closed door and
door opening infiltration. 75 FR 186,
196–197; 75 FR 55068, 55084–55085.
DOE did not ultimately adopt these
methods as part of the final test
procedure because DOE concluded that
steady state infiltration was primarily
influenced by on-site assembly practices
rather than the performance of
individual components. 76 FR 21580,
21594–21595 (April 15, 2011).
Similarly, DOE stated that, based on its
experience with the door manufacturing
industry, door opening infiltration is
primarily reduced by incorporating a
separate infiltration reduction device at
the assembly stage of the complete
walk-in. Id.
In the April 2022 NOPR, DOE did not
propose to include air infiltration in the
test procedure. 87 FR 23920, 23943.
However, the Efficiency Advocates
encouraged DOE to incorporate a
measurement of air infiltration for walkin doors because it would improve the
representativeness and encourage the
development and deployment of
technologies that can save energy.
(Efficiency Advocates, No. 37 at p. 4)
DOE did not receive any data or
recommendations for how to
incorporate the measurement of air
infiltration for walk-in doors into the
test procedure in response to either the
June 2021 RFI or the April 2022 NOPR.
DOE has concluded that additional
investigation is needed to adopt a test
procedure that considers air infiltration
for walk-in doors and thus is not
adopting provisions pertaining to air
infiltration at this time. DOE intends to
consider data on the magnitude of air
infiltration for walk-ins as it becomes
available for appropriate evaluation of
the representativeness of including it in
the test procedure for walk-in doors.
As previously mentioned, EPCA
requires air infiltration limiting devices
on all doors. (42 U.S.C. 6313(f)(1)(A)–
(B)) Even though air infiltration is not
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currently evaluated as part of the
current test procedure and thus not part
of the performance standard, all walk-in
doors are subject to the prescriptive
requirements in the energy conservation
standard pertaining to air infiltration
limiting devices. (10 CFR 431.306(a)(1)–
(2))
D. Amendments to Appendix A for
Display Panels
Appendix A specifies the test
procedure to determine energy
consumption of walk-in display panels,
which are not currently subject to any
daily energy consumption performance
standards but are subject to the
prescriptive requirements at 10 CFR
431.306. The existing test procedure for
walk-in display panels is very similar to
that of walk-in doors in that it requires
a U-factor test using NFRC 100–2010,
which is used to determine the thermal
conduction through the display panel
and ultimately the total daily energy
consumption. The existing display
panel test procedure differs, however,
from that of walk-in doors in that direct
and indirect electrical energy
consumption are not included in the
test procedure.
In the April 2022 NOPR, DOE
proposed to apply all the test
requirements proposed for determining
display door conduction load and
energy consumption to determining
display panel conduction load and
energy consumption, except for the
provisions applicable to electrical
components and PTO values. 87 FR
23920, 23943.
Anthony agreed that the test
procedure for display panels should be
similar to the test procedure for display
doors, but it disagreed with DOE’s
proposal that provisions applicable to
electrical components and PTO values
should be excluded from the test
procedure for display panels. (Anthony,
No. 31 at p. 7) Anthony stated that
display panels can have heaters and
lights. (Id.)
DOE acknowledges Anthony’s
feedback regarding display panels;
however, DOE does not currently have
sufficient information on display panel
electrical components and PTO values
to adopt provisions for electrical
components for display panels. DOE
may do so in a future rulemaking,
however at this time, DOE is adopting
the changes to section III.C of appendix
A for determining display panel
conduction load and energy
consumption as proposed in the April
2022 NOPR.
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E. Amendments to Appendix B for
Panels and Non-Display Doors
The insulation R-value of walk-in
non-display panels and non-display
doors is determined using appendix B.
In the April 2022 NOPR, DOE proposed
to modify appendix B to improve test
representativeness and repeatability. 87
FR 23920, 23943. Specifically, DOE
proposed to make the following
revisions to appendix B: (1) reference
the updated industry standard ASTM
C518–17; (2) include more detailed
provisions on measuring insulation
thickness and test sample thickness; (3)
provide additional guidance on
determining parallelism and flatness of
test specimen; and (4) reorganize
appendix B so it is easier for
stakeholders to follow as a step-by-step
test procedure. Id.
In response to the appendix B
proposals, Bally commented that the
proposed regulations will be
burdensome for laboratories to conduct.
(Bally, No. 40 at p. 4) DOE
acknowledges Bally’s comment;
however, DOE has concluded that the
proposed amendments would not be
unduly burdensome and would improve
test representativeness and repeatability
as discussed in sections III.E.1 through
III.E.5 of this document. Test procedure
costs and impacts because of the
adopted changes are further discussed
in section III.K.2 of this document. DOE
does not expect that the adopted
changes to appendix B, discussed
further, will alter measured R-values;
therefore, no retesting or recertification
is required.
Additionally, AHRI commented
generally that they would like to
understand if display doors, nondisplay doors, and panels use the same
calculation. (AHRI, No. 30 at p. 4) DOE
defines each of these components
separately (see subpart R of 10 CFR
431.302) and their respective test
procedures are described in appendix A,
and appendix B. The procedure for
determining energy consumption of
display doors begins at section 4.4 of
appendix A. The procedure for
determining energy consumption of
non-display doors begins at section 4.5
of appendix A. Sections 4.4 and 4.5 of
appendix A follow the same
methodology of accounting for thermal
conduction through the door
(represented in the form of additional
refrigeration system energy), the direct
electrical energy consumption of
electricity-consuming devices sited on
the door, and the indirect electrical
energy consumption of electricityconsuming devices represented in the
form of additional refrigeration system
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energy consumption. Panels not
classified as display panels follow the
test procedure in appendix B, which
determines the R-value of insulation for
only the foam of the panel.
Furthermore, DOE clarifies that in the
following sections, the changes
discussed are specifically in the context
of walk-in panels; however, DOE notes
that non-display doors are also subject
to the prescriptive R-value requirement
at 10 CFR 431.306(a)(3) and that the Rvalue for walk-in door insulation is
determined using appendix B. The
following sections describe the
modifications that DOE is adopting in
appendix B.
hours of extraction from the panel.
Given the existing technology on the
market today, DOE believes 24 hours is
an appropriate limit that balances Kfactor representativeness with test
burden, and therefore DOE is
maintaining the current requirement
that testing be completed within 24
hours of cutting a test specimen from
the envelope component.
Correspondingly, DOE is not referencing
Section 7.3 of ASTM C518–17 regarding
specimen conditioning as part of its
update to appendix B.
1. 24-Hour Testing Window
As mentioned in the April 2022
NOPR, DOE is aware that the test
specimen and conditioning instruction
and example given in section 7.3 of
ASTM C518–04 and ASTM C518–17
conflict with the provision in section
4.5 of the DOE test procedure at
appendix B. The DOE test procedure
requires testing be completed within 24
hours of specimens being cut for the
purpose of testing, while ASTM C518–
04 and ASTM C518–17 require that
specimens be conditioned prior to
testing based on material specifications,
which could be longer than 24 hours. 87
FR 23920, 23942.
Bally commented that a cut sample
should not be exposed to air for longer
than 8 hours because foam samples
become irreversibly de-conditioned
once removed from a panel. (Bally, No.
40 at pp. 3–4) Bally included a technical
bulletin from 1984 that states that, in
general, a 1-inch cut section of foam can
increase in K-factor about 5 to 10
percent in a few days. (Bally, No. 40,
Attachment 2) 30
It is DOE’s understanding that since
the technical bulletin referenced by
Bally was published, there have been
changes to the blowing agents used in
polyurethane foam, the most common
foam insulation type used in walk-in
panels. Additionally, no specific data on
the change in K-factor beyond 8 hours
was provided. Recent tests conducted
by DOE demonstrate that there is no
measurable difference in K-factor for
specimens tested immediately after
extraction from the complete panel as
compared to specimens tested 24 hours
after extraction from the complete
panel. DOE has not evaluated changes to
K-factor of a test specimen beyond 24
Section 4.5 of appendix B currently
requires that K-factor of a 1 ± 0.1-inch
sample of insulation be determined
according to ASTM C518–04.
To make the test procedure in
appendix B more repeatable, DOE
proposed in the April 2022 NOPR to
include instructions for determining
both the total insulation thickness as
well as the test specimen insulation
thickness prior to conducting the test to
determine K-factor using ASTM C518–
17, which is substantively the same as
determining the K-factor according to
ASTM C518–04. 87 FR 23920, 23944.
DOE also proposed step-by-step
instructions for specimen preparation,
including detailed instructions of the
number and locations of thickness and
area measurements and from where the
test specimen should be removed from
the overall envelope component. Id.
DOE proposed to require the following
for determining the total thickness of
the foam, tfoam, from which the final Rvalue is calculated:
• The thickness around the perimeter
of the envelope component is
determined as the average of at least 8
measurements taken around the
perimeter that avoid the edge region.31
• The area of the entire envelope
component is calculated as the width by
the height of the envelope component.
• A sample is cut from the center of
the envelope component relative to the
envelope component’s width and
height. The specimen to be tested using
ASTM C518–17 will be cut from the
center sample.
• The thickness of the sample cut and
removed from the center of the envelope
component is determined as the average
of at least 8 measurements, with at least
2 measurements taken in each quadrant.
30 The Bally comment included two supplemental
attachments: Attachment 1, ‘‘Solid and Opaque
Eval,’’ and Attachment 2, ‘‘BTB—Aging of Foam.’’
DOE will reference as ‘‘Attachment 1’’ and
‘‘Attachment 2’’ throughout this document. Both
attachments are available on the docket.
31 Edge region means a region of the panel that
is wide enough to encompass any framing members.
If the panel contains framing members (e.g., a wood
frame), then the width of the edge region must be
as wide as any framing member plus an additional
2 in. ± 0.25 in. See section 3.1 of appendix B.
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• The area of the sample cut and
removed from the center of the envelope
component is determined as the width
by the height of the cut sample.
• Any facers on the sample cut from
the envelope component shall be
removed while minimally disturbing the
foam, and the thickness of each facer
shall be the average of at least 4
measurements.
• The average total thickness of the
foam shall then be determined by
calculating an area-weighted average
thickness of the complete envelope
component less the thickness of the
facers.
Id.
For preparing and determining the
thickness of the 1-inch test specimen,
DOE proposed the following:
• A 1 ± 0.1-inch-thick specimen shall
be cut from the center of the cut
envelope sample removed from the
center of the envelope component.
• Prior to testing, the average of at
least 9 thickness measurements at
evenly spaced intervals around the test
specimen shall be the thickness of the
test specimen, L.
Id.
In the April 2022 NOPR, DOE
requested feedback on the proposed
provisions relating to test specimen and
total insulation thickness and test
specimen preparation prior to
conducting the ASTM C518–17 test.
Anthony agreed with both of the
proposals. (Anthony, No. 31 at p. 7)
Bally referenced the EPCA calculation
for R-value and recommended that Rvalue remain calculated with that
formula. (Bally, No. 40 at p. 3) Bally
commented that it believes the tolerance
of 1 ± 0.1 inch is not necessary because
the sample preparation process would
need to be restarted, but a smaller
sample could have been used to
determine K-factor. (Bally, No. 40 at p.
4)
In response to Bally’s comment, DOE
is not adopting any changes to the Rvalue formula; rather, DOE is providing
additional instruction so that the inputs
to the R-value formula, namely the Kfactor, are determined in a consistent
and more repeatable manner. At this
time, DOE has determined that the 1 ±
0.1 inch tolerance is still necessary to
appropriately and consistently measure
K-factor. Therefore, DOE is adopting the
provisions outlined in the April 2022
NOPR for determining test specimen
and total thickness of insulation in
appendix B.
3. Parallelism and Flatness
The test procedure for determining Rvalue requires that the two surfaces of
the tested sample that contact the hot
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plate assemblies (as defined in ASTM
C518–04 and ASTM C518–17) maintain
a flatness tolerance of ±0.03 inches and
maintain parallelism of one another
with a tolerance of ±0.03 inches.32 See
section 4.5 of appendix B. As discussed
in the April 2022 NOPR, the current test
procedure does not provide direction to
measure or calculate flatness and
parallelism. DOE believes, however, that
accurate and repeatable determination
of a specimen’s R-value requires the
specimen under test to be both flat and
parallel. 87 FR 23920, 23944.
In the April 2022 NOPR, DOE
proposed to include several steps for
determining the parallelism and flatness
of the test specimen in appendix B:
• Prior to determining the specimen
thickness, the specimen would be
placed on a flat surface and gravity used
determine the specimen’s position on
the surface. As specified previously, a
minimum of nine thickness
measurements would be taken at
equidistant positions on the specimen.
These measurements would be
associated with side 1 of the specimen.
• The least squares plane of side 1 is
determined based on the height
measurements taken. The theoretical
height of the least squares plane is
determined at each measurement
location in the x and y (length and
width) direction of the specimen.
• The difference at each measurement
location between actual height
measurement and theoretical height
measurement based on the least squares
plane is calculated. The maximum value
minus the minimum value is the
flatness associated with this side (side
1). For each side of the specimen to be
considered flat, this value would need
to be less than or equal to 0.03 inches.
• Flip the specimen so that side 1 is
now on the flat surface and let gravity
determine the specimen position on the
surface. Repeat the steps above for side
2 of the specimen.
• To determine if each side of the
specimen is parallel, the theoretical
height at the four corners (i.e., at points
(0,0), (0,12), (12,0), and (12,12)) of the
specimen must be calculated using the
least squares plane. The difference in
the maximum and minimum heights
would represent the parallelism of one
side and would need to be less than or
32 Maintaining a flatness tolerance means that no
part of a given surface is more distant than the
tolerance from the ‘‘best-fit perfectly flat plane’’
representing the surface. Maintaining parallelism
tolerance means that the range of distances between
the best-fit perfectly flat planes representing the two
surfaces are no more than twice the tolerance (e.g.,
for square surfaces, the distance between the most
distant corners of the perfectly flat planes minus the
distance between the closest corners is no more
than twice the tolerance).
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equal to 0.03 inches for the specimen to
be considered parallel.
87 FR 23920, 23945.
AHRI and Anthony agreed with the
proposed provisions relating to
determining parallelism and flatness of
the test specimen. (AHRI, No. 30 at p.
4; Anthony, No. 31 at p. 8) Bally stated
that commercial devices used to
measure K-factor using ASTM C518
have an internal check on flatness and
parallelism so a sample that is out of
tolerance will be flagged. (Bally, No. 40
at pp. 4–5)
DOE acknowledges Bally’s comment,
however, it is DOE’s understanding that
not all manufacturers or laboratories use
the same commercial device to measure
K-factor. Regardless of the device used,
a consistent procedure for determining
parallelism and flatness is necessary.
DOE is adopting the method for
determining parallelism and flatness in
appendix B as described in the April
2022 NOPR. 87 FR 23920, 23945.
4. Insulation Aging
The current test procedure for
determining panel R-value does not
account for insulation aging. ‘‘Aging’’ of
foam insulation refers to how diffusion
of blowing agents out of the foam and
diffusion of air into the foam impacts
thermal resistance of insulation
materials. The gaseous blowing agents
contained in the foam provide it with
much of its insulating performance,
represented by the R-value of the foam
material. Because air has a lower
insulating value than the blowing agents
used in foam insulation, the increased
ratio of air to blowing agent reduces the
foam insulation performance, which
reduces the R-value of the foam material
over time. The building industry uses
long-term thermal resistance (‘‘LTTR’’)
to represent the R-value of foam
material over its lifetime by describing
the insulating performance changes due
to diffusion over time. The presence of
impermeable facers on a foam structure
may delay the rate of aging or reduce the
decrease in R-value when compared to
a foam structure that is unfaced or has
permeable facers. Blowing agents and
temperature and humidity conditions
may also affect the amount or rate of
aging that occurs in a foam structure.
In the April 2022 NOPR, DOE
discussed its previous adoption and
subsequent removal of a test procedure
that considered aging of foam
insulation. 87 FR 23920, 23945–23946.
DOE rescinded the method that
evaluated aging because of stakeholder
concerns regarding test burden and the
availability of laboratories to conduct
the adopted test procedure. 79 FR
23788, 27405–27406. As such, DOE did
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not propose to add test procedure
provisions regarding aging in the April
2022 NOPR. 87 FR 23920, 23945–23946.
DOE also did not propose to consider
the effects of aging in assessment and
enforcement testing because a recent
study at Oak Ridge National Laboratory
(‘‘ORNL’’) found the effects of foam
insulation aging for panels sold with
facers to be minimal when panel facers
remain attached to the foam (i.e., when
the panel remains intact).33 Id. In the
April 2022 NOPR, DOE requested
comment on other comparable data or
studies of foam panel aging that are
representative of the foam insulation,
blowing agents, and panel construction
currently used in the manufacture of
walk-in panels. Id. DOE also requested
comment on whether manufacturers
have been certifying R-value at time of
manufacture or after a period of aging.
Id.
In response, AHRI suggested that any
aging criteria should be based on the
conditioning requirements in ASTM
C518. (AHRI, No. 30 at p. 4) AHRI also
stated that typical aging periods to
ensure dimensional stability of finished
foam has been reached vary between 14
and 28 days. Id. Bally stated that it tests
its foam without aging. (Bally, No. 40 at
p. 5) RSG commented that it would like
to limit the time between manufacture
and testing as much as possible. (RSG,
No. 41 at pp. 1, 11) RSG stated that it
has conducted its own test, where it
calculated R-value every 2 weeks for 6
months after manufacture; it found that
R-value drops sharply at the beginning,
followed by a slower rate of decline.
(Id.)
In response to AHRI’s suggestion
regarding aging criteria, DOE testing has
shown that there is no measurable
difference in K-factor for specimens
tested immediately after extraction from
the complete panel as compared to
specimens tested 24 hours after
extraction from the complete panel,
even though it would be expected that
aging of a thinner sample without facers
would be more significant than a fully
intact panel. Therefore, DOE expects the
aging of an intact panel to be negligible
after 24 hours.
Bally’s and RSG’s comments suggest
that manufacturers are rating R-value
33 A presentation on ORNL’s study can be found
online at www.osti.gov/biblio/1844325-impactthermal-bridging-imperfections-agingeffectivevalue-walk-cooler-freezer-panels. DOE
acknowledges that panels are shipped for assembly
in walk-ins with the foam already in final chemical
form between facers. Thus, the most applicable
evaluation of change in insulation R-value over
time is demonstrated by the red data points (labeled
‘‘2’’) for the foam that remained intact with the
facers on slides 26 through 30 of ORNL’s
presentation.
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without considering the effects of aging
and would prefer to limit the amount of
time between manufacture and test. As
stated previously, DOE has found that
there are minimal effects of foam
insulation aging for panels sold with
facers when panel facers remain
attached to the foam. For assessment
and enforcement testing conducted to
support the enforcement of DOE’s
energy conservation standards, DOE is
generally able to test samples within
one to three months after receipt. The
time lag from when the panel is
manufactured and when testing is
conducted at a laboratory is typically
significantly shorter than that evaluated
in the ORNL study. Therefore, DOE
expects any reduction in R-value to be
minimal from date of manufacture to
assessment or enforcement test date.
Additionally, walk-in panels received
by DOE for assessment and enforcement
testing are evaluated upon arrival to
ensure that they are received intact (i.e.,
with facers) and undamaged, and testing
of the specimen is completed within 24
hours of sample removal from the panel,
as specified in section 4.5 of the DOE
test procedure in appendix B. DOE does
not expect any reduction in R-value
within 24 hours of the sample being cut
from the panel. Therefore, at this time,
DOE will not consider insulation aging
in the test procedure nor in the
Department’s assessment and
enforcement testing based on the
available data. DOE may consider
additional data on this issue as it
becomes available.
5. Overall Thermal Transmittance of
Non-Display Panels
The current test procedure for nondisplay panels does not measure the
overall thermal transmittance of a walkin panel. 87 FR 23920, 23946. DOE
previously adopted a test method for
measuring overall thermal transmittance
of a walk-in panel, including the
impacts of thermal bridges 34 and edge
effects (e.g., due to structural materials
and fixtures used to mount cam locks).
76 FR 21580. However, after receiving
comments concerning test and cost
burden and the lack of availability of
laboratories to conduct the test
procedure, DOE rescinded this portion
of the walk-in panel test procedure. 79
FR 27388, 27405–27406. Based on past
concerns, DOE did not propose any
provisions to evaluate overall thermal
transmittance of non-display panels in
34 Thermal bridging occurs when a more
conductive material allows an easy pathway for
heat flow across a thermal barrier.
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the April 2022 NOPR. 87 FR 23920,
23946.
In response, the Efficiency Advocates
encouraged DOE to investigate
appropriate methods to capture the
overall thermal transmittance of walk-in
panels. (Efficiency Advocates, No. 37 at
p. 4) DOE did not receive any other
feedback on its proposal or specific
suggestions on how to implement a
procedure that would measure overall
thermal transmittance while minimizing
the test cost burdens previously
identified.
DOE continues to have the same
concerns regarding test burden and lack
of availability of test facilities to
conduct any potential overall thermal
transmittance testing of walk-in panels.
Therefore, DOE is not including a test
procedure in appendix B for
determining overall thermal
transmittance of non-display panels at
this time.
F. Amendments to Appendix C for
Refrigeration Systems
Appendix C provides test procedures
to determine the AWEF and net capacity
of walk-in refrigeration systems. DOE
does not expect that the adopted
changes to appendix C will alter
measured capacity values or AWEF.
Therefore, DOE expects no retesting or
recertification will be required. Rather,
the revisions for appendix C address
repeatability issues that DOE has
observed through its testing of walk-in
refrigeration systems.
The following sections describe the
modifications that DOE is making to
appendix C, in this final rule.
1. Refrigeration Test Room Conditioning
The DOE test procedure for walk-in
refrigeration systems specifies
temperature and/or humidity conditions
for the test chambers. (See, e.g., Tables
3 through 16 of AHRI 1250–2009, which
is incorporated by reference in the DOE
test procedure.) Section C6.2 of AHRI
1250–2009 requires that the
environmental chambers ‘‘be equipped
with essential air handling units and
controllers to process and maintain the
enclosed air to any required test
conditions.’’ This requirement is also in
section C5.2.2 of AHRI 1250–2020.
However, DOE is aware that some test
facilities may rely on the test unit to
cool and dehumidify the test room.
When the test unit is used to cool and
dehumidify the test room, frost
accumulation on the test unit’s coils
during pretest conditioning is possible
and can affect the results of the capacity
test. 87 FR 23920, 23947. Section C5.1
of AHRI 1250–2020 states that the unit
cooler under test may be used to aid in
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achieving the required test chamber
ambient temperatures prior to beginning
a steady-state test but requires the unit
under test to be free from frost before
initiating steady-state testing. In the
April 2022 NOPR, DOE proposed to
specify that for applicable system
configurations (matched pairs, singlepackaged systems, and unit coolers
tested alone), the unit under test may be
used to help achieve the required test
chamber conditions prior to beginning
any steady-state test. 87 FR 23920,
23947. Additionally, DOE proposed to
require a visual inspection of the test
unit coils for frost before the steadystate test begins. Id. 87 FR 23920, 23947.
DOE requested comment on the
proposed pretest coil inspection
requirement and asked for feedback on
current chamber conditioning practices
within the industry. 87 FR 23920,
23947.
AHRI, HTPG, Hussmann, KeepRite,
Lennox, and National Refrigeration
disagreed with allowing the unit under
test to condition the test room because
it cannot sufficiently remove humidity
from the room. (AHRI, No. 30 at p. 4;
HTPG, No. 32 at p. 4; Hussmann, No. 38
at p. 3; KeepRite, No. 36 at p. 1; Lennox,
No. 35 at pp. 2–3; National
Refrigeration, No. 39 at p. 1) The same
group of commenters also stated that the
requirement for the unit to be ‘‘free from
frost’’ is too subjective. (Id.) Hussmann
mentioned that defrost could reduce the
frost present, but that would result in a
frosted-coil test instead of a dry-coil
test. (Hussmann, No. 38 at p. 3) AHRI
and Hussmann suggested that, if the
unit under test is used to condition the
test chamber, the unit’s capacity be
tested both before and after the test to
ensure that the unit’s capacity is not
decreasing due to frost load. (AHRI, No.
30 at pp. 4–5; Hussmann, No. 38 at p.
3) Lennox recommended that
environmental chambers be equipped
with air handlers to maintain test
conditions. (Lennox, No. 35 at pp. 2–3)
RSG agreed with the DOE’s proposed
inspection requirement. (RSG, No. 41 at
p. 1)
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2. DOE notes that the proposed test
procedure allows the unit under test to
aid in achieving the required test
chamber conditions This implies that
other conditioning equipment may be
necessary and that the unit under test
should never be the sole conditioner. In
addition, DOE notes that the
amendments to test procedure are in
alignment with section C5 of AHRI
1250–2020, the most current industry
test procedure. DOE has determined that
a visual inspection is the most practical
way to confirm that coils are free from
frost and that while such an inspection
may include subjective judgement about
the presence of frost, it is better than no
inspection at all. DOE has therefore
determined that a visual inspection of
the coils is sufficient. DOE also notes
that the operating tolerances discussed
in section III.F.5 of this document,
appendix C to subpart R of 10 CFR part
431, and AHRI 420–2007 ensure that
any significant impact of frost collection
during a test would invalidate the test
unless the unit capacity remains steady
throughout a test.35 These requirements
make the pre- and post-test
measurement of capacity unnecessary.
Therefore, DOE is adopting the test
procedure as proposed in the April 2022
NOPR. DOE is adding the new
requirement to appendix C, which also
carries over to appendix C1.
Temperature Measurement
Requirements
a. Suction Line Temperature
Measurement
The current DOE test procedure
requires measuring refrigerant
temperature entering or leaving the unit
cooler using either thermometer wells or
immersed sensors to determine
refrigerant enthalpy as part of the
capacity measurement for matched pairs
and unit coolers tested alone (see 10
CFR part 431, subpart R, appendix C,
section 3.2.1). The capacity
determination for dedicated condensing
units tested alone is based on the
refrigerant conditions leaving the
condensing unit and standardized
conditions leaving the unit cooler, as
specified in section 3.4.2.1 of appendix
35 For dedicated condensing units and matched
pairs, new mass flow operating tolerances are
adopted as discussed in section III.F.5, and existing
refrigerant temperature tolerances are specified in
section 3.1.1 of appendix C to subpart R of 10 CFR
part 431. These two measurements would drift out
of tolerance during a test if frost conditions were
significantly affecting capacity measurements for
such systems. Similarly, table C3 of AHRI 420–2007
includes a refrigerant mass flow tolerance and table
C4 of AHRI 420–2007 includes inlet and outlet
saturation temperature operating tolerances. These
measurements would drift out of tolerance during
a test if frost conditions were significantly affecting
capacity measurements of unit coolers tested alone.
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C. In the April 2022 NOPR, DOE
proposed to clarify that, when testing
dedicated condensing units,
thermometer wells or immersed sensors
can be used only at the condensing unit
liquid outlet and are not required to be
used for the suction line. 87 FR 23920,
23947.
AHRI, KeepRite, Lennox, National
Refrigeration, and HTPG all commented
that they do not support the proposal to
forgo temperature measuring
requirements for the suction line when
testing dedicated condensing units.
(AHRI, No. 30 at p. 5; KeepRite, No. 36
at p. 1; Lennox, No. 35 at p. 3; National
Refrigeration, No. 39 at p. 1; HTPG, No.
32 at p. 4) AHRI also stated that legacy
calculation and simulation systems use
existing temperature measurements of
the suction discharge. (AHRI, No. 30 at
p. 5)
DOE acknowledges that existing
systems and calculations may depend
on suction line temperature
measurements. For this reason, DOE
retracts its proposal from the April 2022
NOPR and in this final rule maintains
the requirements for thermometer wells
or immersed sensors for both the
suction and liquid lines when testing
dedicated condensing units alone.
AHRI-Wine also commented that
wine cellar manufacturers are
concerned that the wells are not large
enough for temperature measurements.
(AHRI-Wine, No. 30 at p. 2) DOE notes
that thermometer wells are required in
the current DOE test procedure for
temperature measurement. DOE
addresses these concerns in the
remainder of this section.
b. Surface-Mount Temperature
Measurement Allowances for Small
Diameter Tubing
As mentioned in the April 2022
NOPR, DOE has found that
implementing the current thermometer
well requirement for refrigerant lines
with an outer diameter of 1–2 inch or
less can restrict the refrigerant flow and
thus affect temperature measurements.
To rectify this issue and to ensure that
all walk-in refrigeration systems can be
tested according to the DOE test
procedure, DOE proposed allowing an
alternative approach when the
refrigerant line tubing diameter is 1–2
inch or less, in which the temperature
measurement would be made using two
surface-mounted measuring instruments
with a minimum accuracy of ±0.5 °F,
which would be averaged to obtain the
reading. Additionally, DOE proposed
that the two measuring instruments
must be mounted on the pipe separated
by 180 degrees around the refrigerant
tube circumference. To ensure
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measurements are not affected by
changes in ambient temperature, DOE
proposed requiring use of 1-inch-thick
insulation around the measuring
instruments that extends 6 inches upand downstream of the measurement
locations. Where this technique is used
to measure temperature at the expansion
valve inlet, DOE proposed to require
that the measurement be within 6
inches of the device.
With respect to tube surface
measurements, AHRI and KeepRite
stated that the temperature
measurements on the tube surface are
not accurate enough, and that this
measurement is too critical to allow
this. (AHRI, No. 30 at p. 5; KeepRite,
No. 36 at p. 1) AHRI and KeepRite also
stated that a low-temperature reading
resulting from surface-mounted
temperature measurement devices could
lead to bubbling upstream of the
expansion valve, resulting in inflated
AWEF values. (AHRI, No. 30 at p. 5;
KeepRite, No. 36 at p. 2) Lennox
supported DOE’s proposal to allow
surface-mounted temperature sensors
but encouraged DOE to work with
industry to ensure the full scope of
applications can be covered with these
requirements. (Lennox, No. 35 at p. 3)
Additionally, AHRI and KeepRite
suggested allowing transition to a pipe
large enough for a thermometer well. Id.
National Refrigeration also
recommended maintaining the
thermometer well requirement for small
diameter tubing and allowing for larger
diameter tubing to accommodate
thermometer wells. (National
Refrigeration, No. 39 at p. 1) Regarding
location of the temperature
measurement, AHRI and KeepRite
agreed with the allowance to locate the
temperature sensor within 6 inches;
however, they suggested that the test
procedure should further clarify if the
measurement is from the body of the
expansion valve or the joint with the
liquid line. (AHRI, No. 30 at p. 5;
KeepRite, No. 36 at p. 2) KeepRite
further suggested allowing the dual
liquid temperature measurements to be
further upstream in a thermometer well
with a secondary surface measurement
6 inches from the expansion valve and
with sufficient insulation such that the
surface temperature reading does not
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differ by more than 2 °F from the
thermometer well measurements.
(KeepRite, No. 36 at p. 2)
Specific to the liquid line temperature
measurement location, DOE clarifies
that the measurement is from the center
of the body of the expansion valve.
AHRI-Wine and HTPG agreed with
the proposal to allow two external
temperature measurements for small
diameter tubing. (AHRI-Wine, No. 30 at
p. 2; HTPG, No. 32 at p. 4)
DOE acknowledges the concerns from
stakeholders regarding the use of surface
measurements and will consider data
from industry on this issue in future
rulemakings. DOE has conducted testing
using the approach proposed in the
April 2022 NOPR and has determined
that the approach provides
representative measurements and
prevents bubbling. Therefore, DOE is
adopting the surface mount temperature
measurement test provisions as
proposed in the April 2022 NOPR.
These requirements will be added to
appendix C, and will also carry over to
appendix C1.
3. Hierarchy of Installation Instruction
and Specified Refrigerant Conditions for
Refrigerant Charging and Setting
Refrigerant Conditions
As discussed in the April 2022 NOPR,
DOE is aware that sometimes multiple
installation instructions may be
available for a unit, and different test
results could be obtained based on
which instructions are used. 87 FR
23920, 23948. DOE proposed a
hierarchy for installation instructions
and setup of refrigerant conditions to
improve test repeatability by indicating
which manufacturer-specified
conditions would be prioritized during
setup.
Setup conditions or instructions may
be stamped on the unit nameplate or
otherwise affixed to the unit, shipped
with the unit, or available online. DOE
has encountered walk-in refrigeration
units for which these three sources of
instruction provide different values or
conflicting directions. To ensure
consistent setup during testing, DOE
proposed in the April 2022 NOPR that
instructions or conditions stamped on
or adhered to a test unit take
precedence, followed by instructions
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shipped with the unit. Id. Because
online instructions can be easily
revised, DOE proposed that instructions
or other setup information found online
would not be used to set up the unit for
testing.
Furthermore, setting of refrigerant
charge level or refrigerant conditions is
a key aspect of setup of refrigeration
systems, whether for field use or testing.
In the April 2022 NOPR, DOE proposed
that units be charged and set up at
operating conditions specified in the
test procedure (for outdoor refrigeration
systems, DOE proposed use of operating
condition A) based on the installation
instructions, using the proposed
hierarchy (i.e., prioritizing instructions
stamped or adhered to unit over
instructions included in a manual
shipped with the unit). Id. In cases
where instructions for refrigerant
charging or refrigerant conditions are
provided only online or not at all, DOE
proposed that a generic charging
approach be used instead. If the
installation instructions specify
operating conditions to set up the
refrigerant charge or refrigerant
conditions, those conditions would be
used rather than the conditions
specified in the test procedure. Id.
DOE determined that in some cases, a
manufacturer specifies a range of
conditions for superheat,36 subcooling,
and/or refrigerant pressure. In these
instances, DOE proposed to treat the
midpoint of that range as the target
temperature/pressure, and a test
condition tolerance would be applied to
the parameter that is equal to half the
range. For example, if a manufacturer
specifies a target superheat of 5 to 10 °F,
the target for test would be 7.5 °F and
the average value during operation at
the setup operating conditions would
have to be 7.5 °F ± 2.5 °F. Alternatively,
installation instructions may specify a
refrigerant condition value without a
range or without indicated tolerances. In
such cases, DOE proposed that
standardized tolerances be applied as
indicated in Table III.3. These
tolerances depend on the kind of
refrigerant expansion device used.
36 Superheat is the difference between vaporphase refrigerant temperature and the dew point
corresponding to the pressure level.
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TABLE III.3—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF
REFRIGERANT CONDITIONS
Fixed orifice or capillary tube
Priority
Method
Tolerance
Priority
Method
Tolerance
1 .......................
Superheat .......................
±2.0 °F ............................
1 .....................
Subcooling ......................
2 .......................
±4.0 psi or ±1.0 °F .........
2 .....................
±2.0 psi or ±0.8 °F .........
3 .....................
High Side Pressure or
Saturation Temperature.
Superheat .......................
4 .......................
High Side Pressure or
Saturation Temperature.
Low Side or Saturation
Temperature.
Low Side Temperature ...
10% of the target value;
no less than ±0.5 °F,
no more than ±2.0 °F.
±4.0 psi or ±1.0 °F.
±2.0 °F ............................
4 .....................
5 .......................
6 .......................
High Side Temperature ..
Charge Weight ...............
±2.0 °F ............................
±2.0 oz. ..........................
5 .....................
6 .....................
3 .......................
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Expansion valve
DOE also notes that zeotropic 37
refrigerants have become more common.
When charging with such refrigerants
(i.e., any 400 series refrigerant), DOE
proposed that the refrigerant charged
into the system must be in liquid form.
87 FR 23920, 23948. Charging a system
in liquid form is standard practice for
charging of such refrigerants because the
concentrations of the components of the
blend present in the vapor phase of the
charging cylinder are often skewed from
the intended concentrations of the
refrigerant blend.
If the installation instructions on the
label affixed to (or shipped with) the
unit do not provide instructions for
setting subcooling or otherwise how to
charge with refrigerant for a condensing
unit tested alone or as part of a matched
pair, DOE proposed requiring testing the
unit in a way that is consistent with the
DOE test procedure and the installation
instructions and that also does not cause
the unit to stop operating during testing,
e.g., by shutoff by the high-pressure
switch. DOE believes that such
installation would be most
representative of the way a technician
would set up a system in the field if
there were no refrigerant charge or
subcooling instructions. 87 FR 23920,
23948.
AHRI and Lennox commented that
they agree with the hierarchy of
charging methods, however, they
recommended that DOE allow use of
online documentation. (AHRI, No. 30 at
p. 6; Lennox, No. 35 at p. 3) HTPG also
suggested that electronic instructions be
allowed in addition to paper. (HTPG,
No. 32 at p. 5)
37 A zeotropic refrigerant is a blend of two or
more refrigerants that have different boiling points.
Each refrigerant will evaporate and condense at
different temperatures.
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Low Side Pressure or
Saturation Temperature.
Approach Temperature ..
Charge Weight ...............
As discussed previously, DOE
proposed in the April 2022 NOPR not to
permit online instruction manuals in
part because they can be easily revised.
In consideration of these stakeholder
comments, DOE has determined to
allow use of online instruction manuals,
with certain restrictions. Firstly, online
instructions can be used only if no
instructions or conditions are stamped
on or adhered to a test unit or shipped
with the unit. Secondly, to prevent
revision to online documentation once a
unit has been shipped by the
manufacturer, online instruction
manuals must include a version number
or version date on the unit label or in
the documents that are packaged with
the unit.
In this final rule, DOE is amending
the test procedure such that setup
instructions or conditions stamped on
or adhered to a test unit take
precedence, followed by instructions
shipped with the unit, followed by
online instructions if the version
number or date of the online instruction
manual is referenced on the unit label
or is included in documents that are
packaged with the unit.
AHRI and Lennox recommended that
outdoor units should be charged for
condition C, not condition A. (AHRI,
No. 30 at p. 6; Lennox, No. 35 at p. 4)
DOE has considered the commentors’
recommendations and validated this
charging procedure through testing.
DOE is therefore amending the test
procedure such that units be charged
and set up at operating conditions
specified in the test procedure (for
outdoor refrigeration systems, operating
condition C) based on the installation
instructions, using the hierarchy
summarized in Table III.3 of this
document. DOE notes that many
outdoor condensing units achieve head
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±2.0 °F.
±2.0 psi or ±0.8 °F.
±1.0 °F.
0.5% or 1.0 oz., whichever is greater.
pressure control that uses valves to
‘‘flood’’ the condenser with liquid
refrigerant to maintain sufficiently high
condensing temperature when outdoor
air is cold. If such a condensing unit has
insufficient charge, it will be more
obvious during operation in condition C
(where head pressure control is
generally active) since more charge
would be in the condenser during such
operation under head pressure control.
Hence, DOE concludes that charging in
the C condition rather than the A
condition is appropriate for dedicated
condensing systems (dedicated
condensing units, matched systems, and
single-packaged dedicated systems) that
use a flooded condenser design. DOE
has encountered units that, when
charged at the C condition, will not
operate at the A condition with the
same charge weight due to high pressure
cut out. This suggests the possibility
that following the charging instructions
may lead to two different charge weights
depending on the condition used for
charging. DOE maintains that it is not
representative of field operation to use
different refrigerant charge weights for
the two test conditions, since it is not
expected that refrigerant charge would
be adjusted as ambient temperature rises
and falls for a dedicated condensing
system in the field. As such, DOE is
adopting test provisions such that if a
dedicated condensing system is charged
at the C condition but does not operate
at the A condition due to excess charge
causing high pressure cut out, then
refrigerant charge shall be adjusted to
the highest charge that allows operation
at the A condition. To limit the test
burden of determining this highest
charge, the determination shall be
subject to a stepwise charge adjustment.
Specifically, refrigerant would be
removed in increments of 4 ounces or 5
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percent of the system’s receiver
capacity, whichever is larger, until
operation at the A condition is possible.
All tests, including those at condition C,
will then be performed with this
refrigerant charge.
DOE notes that when conducting the
C condition test for a dedicated
condensing system for which this
charge removal has occurred as
described above, it is possible that the
refrigerant leaving the system no longer
has measurable subcooling. If the
measured subcooling of the refrigerant
leaving the condenser is less than 0 °F,
its state cannot accurately be
determined based on the measurement.
The most direct way to determine the
state of the refrigerant would be to
provide additional cooling to the liquid
line after it leaves the condensing unit
using a flow of a fluid such as water
such that the water mass flow and
temperature rise would be measured
and such that the refrigerant is
subcooled downstream of this heat
exchange. Such an approach would
allow determination of the enthalpy at
the condensing unit exit as the enthalpy
of its subcooled downstream state plus
the additional cooling provided divided
by the mass flow. However, DOE has
determined that such an approach
would require a chilled water, a
refrigerant water heat exchanger, a water
flow meter, temperature sensors, and
provisions for flow and temperature
measurements to be captured by the
data acquisition system. DOE has
determined that this additional
equipment and time required to set up
the additional equipment represent an
inappropriate increase in test burden.
DOE has finalized the test procedure
requiring that if the calculated
subcooling at the condensing unit exit is
less than 0 °F, the liquid at this location
will be assumed to be at saturated liquid
conditions. DOE has determined that
the departure from saturated conditions
is likely to be small. Additionally, this
change in calculation method would
only take place at one of the three test
points. These two factors would lead to
very little, or no, influence over the final
measured AWEF. Further, this would
only be necessary when testing units
using refrigerant enthalpy-based test
methods.
DOE notes that it is also possible for
dedicated condensing systems to
maintain condensing temperature for
low ambient operating conditions using
fan controls rather than condenser
flooding. Units that use fan control to
maintain condenser temperature would
not require significantly more
refrigerant charge when operating at the
C condition compared to the A
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condition. However, the fan controls of
these systems may cause instability in
refrigerant conditions at the lower
ambient temperatures at the C test
condition. As such, DOE has
determined that, for dedicated
condensing systems that exclusively use
fan controls to maintain condensing
temperature at low ambient
temperatures, charging at the A
condition is more appropriate than
charging such units at C condition. The
refrigerant charging proposals in the
April 2022 NOPR sought to minimize
test burden while ensuring the
repeatability and representativeness of
walk-in refrigeration system testing.
Stakeholders correctly pointed out that
charging at the A test condition would
not be representative for systems with
flooded-condenser head pressure
control. Thus, the change to charging at
the C test condition was necessary.
However, DOE has determined through
testing that it is possible that when such
a system is charged under test condition
C, it could fail to operate due to high
pressure cutout when operating under
test condition A. Therefore, in order to
ensure that a valid test can be
conducted, DOE is adding the
additional provisions. DOE believes
these amendments are consistent with
the intent of proposed changes in the
April 2022 NOPR while being
responsive to stakeholder feedback.
Hence, DOE concludes that charging in
the C condition rather than the A
condition is appropriate.
HTPG stated that it agrees that the
unit under test should be set up
according to a hierarchy of conditions.
HTPG further stated, however, that it
was unclear on the rationale for the
inclusion and priority of ‘‘High Side
Pressure or Saturation Temperature,’’
‘‘Low Side Pressure or Saturation
Temperature,’’ ‘‘Approach
Temperature,’’ and ‘‘Charge Weight’’ in
Table III.3. (HTPG, No. 32 at p. 5) HTPG
did not provide detail on why these
parameters should not be included, or
otherwise reprioritized, in the
hierarchy. DOE has developed the
hierarchy summarized in Table III.3
based on its own testing experience and
has observed that these parameters are
specified operating conditions for
certain units. Through that testing DOE
has determined that the priority and
inclusion of the methods listed in Table
III.3 are appropriate.
Lennox stated that hierarchies in
tables 1 and 19 should specify dew vs.
bubble point to remove confusion with
high-glide refrigerants. (Lennox, No. 35
at p. 4) DOE interprets Lennox’s
comment to be in reference to Table III.3
in this document, which in the
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proposed regulatory text was table 1 of
appendix C (see 87 FR 23290, 24000–
24001) and table 19 of appendix C1,
respectively (see 87 FR 23920, 24021).
DOE acknowledges that the proposed
test procedure hierarchy did not clarify
whether the dew or the bubble point
should be used when the saturation
point is specified. However, this should
be addressed in the manufacturer’s
installation instructions, not specified
by the test procedure. To clarify the
intent in the hierarchy, DOE is adding
a note in table 1 of appendix C and table
19 of appendix C1 to indicate that
saturation temperature can refer to
either bubble or dew point calculated
based on a measured pressure, or a coil
measurement, as specified by the
installation instructions. DOE is
adopting this clarification in this final
rule.
AHRI, on behalf of wine cellar
manufacturers, KeepRite, and National
Refrigeration agreed with the charging
hierarchy. (AHRI-Wine, No. 30 at p. 2;
KeepRite, No. 36 at p. 2; National
Refrigeration, No. 39 at p. 1)
DOE received no comment on the
remaining proposals discussed in this
section. In this final rule, DOE is
adopting the testing hierarchy
instructions proposed in the April 2022
NOPR into appendix C, and will also
carry these provisions over to appendix
C1.
a. Dedicated Condensing Unit Charging
Instructions
For dedicated condensing units tested
alone, subcooling is the primary setup
condition. In the April 2022 NOPR, DOE
proposed that if the dedicated
condensing unit includes a receiver and
the subcooling target leaving the
condensing unit provided in the
installation instructions cannot be met
without fully filling the receiver, the
subcooling target would be ignored. 87
FR 23920, 23948. Likewise, if the
dedicated condensing unit does not
include a receiver and the subcooling
target leaving the condensing unit
cannot be met without the unit cycling
off on high pressure, the subcooling
target would be ignored. Also, if no
instructions for charging or for setting
subcooling leaving the condensing unit
are provided in the installation
instructions, DOE proposed that the
refrigeration system would be set up
with a charge quantity and/or exit
subcooling such that the unit operates
during testing without shutdown (e.g.,
on a high-pressure switch) and
operation of the unit is otherwise
consistent with the requirements of the
test procedure and the installation
instructions.
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DOE received no comments in
response to the proposals discussed in
this section. In this final rule, DOE is
adopting the dedicated condensing unit
charging instructions proposed in the
April 2022 NOPR into appendix C, and
will also carry these provisions over to
appendix C1.
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b. Unit Cooler Setup Instructions
For unit coolers tested alone,
superheat is the primary setup
condition. Most WICF refrigeration
systems use either thermostatic or
electronic expansion valves (‘‘EEVs’’)
that respond either mechanically or
through a controller to adjust valve
position to control for superheat leaving
the unit cooler. If the unit under test is
shipped with an adjustable expansion
device, DOE proposed in the April 2022
NOPR that this would be the primary
method to adjust superheat. 87 FR
23920, 23948. However, DOE has
encountered units with expansion
devices that are not adjustable or where
the expansion device does not provide
a sufficient adjustment range to achieve
the superheat target. If the expansion
valve associated with the unit under test
reaches its limit before the superheat
target is met, the specified superheat
may not be met within the specified
tolerance. In this case, DOE proposed in
the April 2022 NOPR that the expansion
valve should be adjusted to obtain the
closest match to the superheat target. Id.
DOE has also encountered unit coolers
with inappropriate expansion devices.
When this occurs, DOE proposed in the
April 2022 NOPR that any expansion
device specified for use with the unit
cooler in manufacturer literature may be
used for the purposes of DOE testing. Id.
In the April 2022 NOPR, DOE also
proposed that an operating tolerance
would not apply to superheat. Hence, if
the system expansion valve control
fluctuates (i.e., if so-called ‘‘hunting’’
occurs, in which the valve position,
temperatures, and/or pressures are
unsteady), it would not invalidate a test.
87 FR 23920, 23948–23949. However, if
the fluctuation is so great that a valid
test cannot be performed (i.e., any
individual measurement of superheat
during the test is zero or less), or if the
operating tolerances for measurements
that would be affected by expansion
device hunting are exceeded (mass flow,
pressure at the unit cooler exit,
evaporator temperature difference),38
the test procedure would allow for
deviation from the installation
38 Evaporator temperature difference (TD) is the
difference in temperature between the entering air
and the refrigerant dew point of the exiting
refrigerant.
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instructions. DOE proposed in the April
2022 NOPR that deviation from the
installation instructions would be at the
discretion of the test laboratory and
could include replacing the expansion
device with a different expansion device
that does not need to be listed in
installation instructions, adjusting the
expansion device to provide an average
superheat that is greater than the target
superheat, or both. 87 FR 23920, 23949.
If the unit’s installation instructions
do not include setting superheat for a
unit cooler tested alone or as part of a
matched pair, DOE proposed in the
April 2022 NOPR that the target
superheat would be 6.5 °F, the same
value required in such circumstances in
AHRI 1250–2020 (see Tables 16 and 17
of AHRI 1250–2020). Id.
AHRI commented that unit cooler
charging should be done based on the
expansion valve controlled by the room,
not the supplied expansion valve.
(AHRI, No. 30 at p. 6) Lennox stated that
it is industry practice to test unit coolers
with EEVs, because use of these valves
eliminates ‘‘hunting’’ and is more
reliable. (Lennox, No. 35 at p. 4) HTPG
stated that it disagrees with the proposal
in the April 2022 NOPR that operating
tolerance would not apply to superheat
and believes it conflicts with AHRI
1250–2020, as well as Table III.3.
(HTPG, No. 32 at p. 5) 39
After consideration, DOE has
determined that using the expansion
valve supplied with the unit cooler is
most appropriate for testing because it
most closely represents field
performance. DOE notes that the
expansion device provided with the
unit cooler or specified in the unit
cooler installation instructions may
result in hunting behavior and may
fluctuate outside the specified
tolerances for superheat. Nevertheless,
these results are expected to be more
representative of field performance than
using a laboratory controlled EEV that
provides steady operation. As discussed
in the preceding paragraphs, the
amended test procedure provides test
laboratories with alternatives if the
expansion devices shipped with the
unit, or specified in the installation
instructions, result in hunting that
interferes with test measurement
tolerances.
DOE is aware that industry test
practices are not currently consistent
with this approach. As such, DOE
recognizes that testing unit coolers with
the expansion device shipped with the
unit may require manufacturers to retest
39 DOE held an ex parte meeting with Lennox and
HTPG to clarify these comments. See Docket No.
EERE–2017–BT–TP–0010–0043.
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28807
and recertify their unit cooler basic
models. DOE is therefore not adopting
the unit cooler expansion device
requirements proposed in the April
2022 NOPR in appendix C. DOE is
instead adopting those provisions only
in appendix C1, which would be
required for demonstrating compliance
with any future amended WICF energy
conservation standards. Manufacturers
would therefore have additional time to
retest and recertify unit cooler basic
models impacted by these requirements.
c. Single-Packaged Dedicated System
Setup and Charging Instructions
DOE has identified multiple setup
issues while testing single-packaged
dedicated systems. Compared to split
refrigeration systems,40 single-packaged
dedicated systems have less adjustment
flexibility due to lack of controls.
Additionally, while many singlepackaged dedicated systems are
marketed as ‘‘fully charged,’’ DOE has
found that many of its test units were
undercharged.
In the April 2022 NOPR, DOE
proposed that one or more pressure
gauges (depending on the number of
conditions that require a pressure
measurement for validation) should be
installed during setup according to the
manufacturer’s installation instructions
to evaluate the charge of the unit under
test and to accurately measure setup
conditions. 87 FR 23920, 23949. The
location of the pressure gauge(s) would
depend on the test setup conditions
given in the installation instructions. If
charging is based on subcooling or
liquid pressure, DOE proposed that the
pressure gauge(s) would be installed at
the service valve of the liquid line. If
charging is based on superheat, low side
pressure, or a corresponding saturation
temperature or dew point temperature,
DOE proposed that the pressure gauge(s)
would be placed in the suction line. 87
FR 23920, 23949.
DOE is aware that installation
instructions for some single-packaged
dedicated systems recommend against
installing charging ports; however, DOE
has observed through testing that some
such units that recommend against
installing charging ports do not operate
once installed due to high- or lowpressure compressor cut off, which is
often a symptom of under- or overcharging or refrigerant loss. These units
are representative of what a contractor
40 ‘‘Split refrigeration systems’’ refer to systems
made up of a condensing unit and a unit cooler that
are connected by refrigerant lines and are not
contained in a single housing. Split refrigeration
systems could be field-matched condensing units
and unit coolers or condensing units and unit
coolers sold as matched pairs.
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would encounter when installing a
walk-in single-packaged dedicated
system in the field. Therefore, in cases
where a unit under test is not operating
due to high- or low-pressure compressor
cut off, DOE proposed in the April 2022
NOPR that a charging port should be
installed, the unit should be evacuated,
and the nameplate charge should be
added. 87 FR 23920, 23949. This
approach would eliminate under- or
over-charging of the unit which would
address compressor cut off.
DOE received no comments in
response to the proposals in this
section. In this final rule, DOE is
adopting the single-packaged dedicated
system setup instructions proposed in
the April 2022 NOPR into appendix C,
and will also carry these provisions over
to appendix C1.
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d. Hierarchy of Setup Conditions if
Manufacturer-Specified Setup
Conditions Cannot Be Met
In DOE’s experience, even when all
the previously discussed measures are
implemented during test setup, some
manufacturer-specified setup conditions
may not be met. In this case, DOE
proposed in the April 2022 NOPR that
the unit under test be set up according
to a hierarchy of conditions like those
used for central air-conditioning
systems and heat pumps. 87 FR 23920,
23949. First, the installation instruction
hierarchy previously discussed in
section III.F.3 would be applied.
Specifically, if a refrigerant-related
setup instruction in the installation
instructions affixed to the unit and a
different instruction in the installation
instructions shipped with the unit
cannot both be achieved within
tolerance, the instruction on the label
takes precedence. Further, if multiple
instructions within the relevant
installation instructions cannot be met,
the proposed hierarchy outlined in
Table III.3 would be applied. The
highest priority condition that can be
satisfied, based on Table III.3, would
need to be met, depending on what kind
of expansion device the system uses.
This approach would ensure that units
are set up consistently across testing
facilities, ensuring more consistent
results.
DOE received no comments in
response to this proposal. In this final
rule, DOE is adopting the hierarchy of
setup conditions proposed in the April
2022 NOPR into appendix C, and will
also carry these provisions over to
appendix C1.
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4. Subcooling Requirement for Mass
Flow Meters
Section C3.4.5 of AHRI 1250–2009
requires that refrigerant be subcooled to
at least 3 °F and that bubbles should not
be visible in a sight glass immediately
downstream of the mass flow meter.
Section 3.2.3 of appendix C allows use
of the sight glass and a temperature
sensor located on the tube surface under
the insulation to verify sufficient
subcooling. DOE testing has shown that
even when the subcooling requirement
is met downstream of the mass flow
meter, the liquid temperature can be
warmer upstream. This difference
results in less subcooling, and mass
flow measurements may not provide
capacity within the required tolerances
(i.e., within 5 percent of each other 41 as
required by section C8.5.3 of AHRI
1250–2009). 87 FR 23920, 23950. In the
April 2022 NOPR, DOE proposed to
include additional instruction to section
3.2.3 of appendix C, to ensure fully
liquid flow at the mass flow meter. Id.
First, DOE proposed that the 3 °F
subcooling requirement be applied at a
location dependent on the location of
the liquid-line mass flow meters. Id.
Specifically, the proposed requirement
applies downstream of any mass flow
meter located in the chamber that
contains the condensing unit under test,
consistent with AHRI 1250–2009.
However, for mass flow meters located
in the chamber that contains the unit
cooler under test, subcooling would
need to be verified upstream. In the
April 2022 NOPR, DOE requested
comments on its proposal to clarify the
location where the 3 °F subcooling
requirement would apply. Id.
AHRI stated that the proposal to
clarify the location where the 3 °F
subcooling applies may be sufficient in
most, but not all, cases. (AHRI, No. 30
at p. 6) AHRI, KeepRite, and National
Refrigeration recommended measuring
temperature before and after the mass
flow meter and calculating subcooling
using the higher of the two temperatures
with the pressure downstream of the
meter to guarantee fully liquid flow.
(AHRI, No. 30 at p. 6; KeepRite, No. 36
at p. 2; National Refrigeration, No. 39 at
p. 2)
HTPG recommended insulating the
flow meter and line set to guarantee
fully liquid flow. (HTPG, No. 32 at p. 5)
41 Section C8.5.3 of AHRI 1250–2009 requires that
the two refrigerant-side gross capacities calculated
based on the two sets of independent temperature,
pressure, and mass flow measurements are within
5 percent of each other to ensure adequate
subcooling. In the absence of adequate subcooling,
the two refrigerant-side gross capacities may not be
within 5 percent of each other due to disagreement
in the mass flow readings.
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HTPG also recommended that for
dedicated condensing unit testing, the
temperature measurement should be
made before the flow meter inlet and for
unit cooler testing, temperature
measurement should be taken after the
flow meter outlet. Id.
Lennox and RSG agreed with DOE’s
proposal to clarify the subcooling
condition measurement location.
(Lennox, No. 35 at p. 4; RSG, No. 41 at
p. 2)
DOE notes that, assuming the mass
flow meters are in the same room as the
dedicated condensing unit, insulating
the flow meter and line set may or may
not help ensure fully liquid flow,
depending on whether the temperature
surrounding the line set and flow meter
are higher or lower than the liquid
temperature. DOE agrees that HTPG’s
recommendation for measuring the
subcooling before and after the mass
flow meters may provide a more
rigorous approach for ensuring adequate
subcooling throughout the flow meter
than the procedure proposed by DOE in
the April 2022 NOPR. However, during
testing, DOE has found that the
subcooling measurement locations
proposed in the April 2022 NOPR
ensure adequate subcooling through the
mass flow meters with reduced test
burden. Therefore, DOE is adopting the
subcooling measurement locations as
proposed in the April 2022 NOPR. DOE
is adding the new requirements to
appendix C, and will also carry these
provisions over to appendix C1.
Second, DOE proposed that active
cooling of the liquid line may be used
to achieve the required subcooling,
because the subcooling at the mass flow
meter outlet may not meet the 3 °F
requirement when the subcooling at the
condensing unit exit is within tolerance
of its target. However, DOE also
proposed requiring that if active cooling
is done when testing a matched pair
(not including single-packaged
dedicated systems), the temperature also
must be measured upstream of the
location where cooling is provided, and
the temperature used to calculate the
enthalpy of the refrigerant entering the
unit cooler be increased by the
difference between the upstream and
downstream measurements. DOE
proposed this adjustment so that active
cooling of the liquid to obtain a mass
flow measurement does not provide a
non-representative boost in calculated
cooling capacity.
In the April 2022 NOPR, DOE sought
comment on its active subcooling and
capacity calculation adjustment
proposals. 87 FR 23920, 23950. In
response, AHRI and KeepRite
recommended adjusting test results for
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active cooling based on suction pressure
when testing matched pairs. (AHRI, No.
30 at p. 6; KeepRite, No. 36 at p. 2)
KeepRite additionally stated that active
subcooling should be constrained to
prevent excessive subcooling and to
obtain consistent results. (KeepRite, No.
36 at p. 2) KeepRite also recommended
additional testing to determine best
practices for an active subcooling
system and presented some possible
best practices. (KeepRite, No. 36 at p. 3)
RSG agreed with DOE’s proposal to
require adjustment of the measured unit
cooler for active cooling. (RSG, No. 41
at p. 2)
DOE acknowledges these comments
and is making the following adjustments
to the final test procedure to address
stakeholder concerns. Instead of
requiring an enthalpy adjustment if
active subcooling is used, DOE is
requiring that, if active subcooling is
used, the line must be reheated such
that the refrigerant is at the same
temperature as it was upstream of the
active subcooling device. This approach
allows recording of an accurate mass
flow measurement with no impact on
the measured capacity of the unit under
test. DOE is adopting the rest of the test
procedures allowing active subcooling
as proposed in the April 2022 NOPR.
DOE is adding the new requirements to
appendix C, and will also carry these
provisions over to appendix C1.
5. Instrument Accuracy and Test
Tolerances
The current DOE test procedure
references AHRI 1250–2009 for
instrument accuracy and test tolerances
with some modifications (see 10 CFR
part 431, subpart R, appendix C, section
3.1). As discussed in the April 2022
NOPR, some tolerances and
instrumentation accuracy requirements
in AHRI 1250–2020 are not consistent
with the current DOE test procedure. 87
FR 23920, 23950. Specifically, DOE
proposed to adopt the following changes
from AHRI 1250–2020 into appendix C:
• Change the measurement accuracy
for the temperature of air entering or
leaving either the evaporator or
condenser from ± 0.25 °F.
• Replacing the ASHRAE 23.1
refrigerant mass flow operating
tolerance of ± 1 percent of the quantity
measured with an operating tolerance of
3 pounds per hour (‘‘lb/h’’) or 2 percent
of the reading (whichever is greater).
DOE did not receive comment on
these proposals in the April 2022 NOPR.
In this final rule, DOE is adopting the
proposed changes from AHRI 1250–
2020 into appendix C. These changes
are not expected to impact measured
values. DOE is adding the new
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requirements to appendix C, and will
also carry these provisions over to
appendix C1.
28809
on the appropriateness of traditional
refrigerant compressor EER values for
use in CO2 unit cooler AWEF
calculations. Id.
AHRI, HTPG, Hussmann, Lennox, and
National Refrigeration all agreed with
the proposal. (AHRI, No. 30 at p. 7;
HTPG, No. 32 at p. 5; Hussmann, No. 38
at p. 6; Lennox, No. 35 at p. 4; National
Refrigeration, No. 39 at p. 2) DOE is
adopting the test procedure as proposed
in the April 2022 NOPR for CO2 unit
coolers and adding the new
requirements to appendix C, and will
also carry these provisions over to
appendix C1.
6. CO2 Unit Coolers
As discussed in the April 2022 NOPR,
CO2 behaves differently than other
refrigerants, as it has a critical
temperature of 87.8 °F.42 Ambient
temperatures greater than 87.8 °F are
common, and the performance of many
refrigeration and air-conditioning
systems are tested using a 95 °F ambient
temperature, as indicated by the A test
condition in Section 5 of AHRI 1250–
2009 (and AHRI 1250–2020). At
temperatures greater than the critical
temperature, the CO2 refrigerant is in a
supercritical state. Since useful cooling
is provided below the critical
temperature, CO2 cycles are said to be
transcritical.
DOE has granted test procedure
waivers to the manufacturers listed in
Table III.1 of this document for certain
basic models of walk-in refrigeration
systems that use CO2 as a refrigerant.
Manufacturers requesting a waiver from
the DOE test procedure for CO2 unit
coolers stated that the test conditions
described in Tables 15 and 16 of AHRI
1250–2009, as incorporated by appendix
C, with modification, cannot be
achieved by, and are not consistent with
the operation of, CO2 direct expansion
unit coolers. The alternate test
procedure provided in these waivers
modifies the test condition values to
reflect typical operating conditions for a
transcritical 43 CO2 booster system.
Specifically, the waiver test procedures
require that CO2 unit cooler testing is
conducted at a liquid inlet saturation
temperature of 38 °F and a liquid inlet
subcooling temperature of 5 °F.
In the April 2022 NOPR, DOE
proposed to adopt in appendix C (and
also in appendix C1), the alternate test
conditions specified in the waivers that
DOE granted for CO2 transcritical unit
coolers for all CO2 unit coolers. Also,
consistent with the waiver alternate test
procedure, DOE proposed that the EER
values in Table 17 of AHRI 1250–2009
(or Table 18 of AHRI 1250–2020 for
appendix C1) be used to determine the
AWEF of all CO2 unit coolers. 87 FR
23920, 23952. DOE requested comment
7. High-Temperature Unit Coolers
As discussed in the April 2022 NOPR,
DOE is aware of wine cellar (hightemperature) refrigeration systems that
fall within the definition of ‘‘walk-in’’
but are unable to be tested under the
current version of the walk-in test
procedure due to their operation at a
temperature range of 45 °F to 65 °F. 87
FR 23920, 23952. Most of the hightemperature refrigeration systems that
DOE is aware of are either singlepackaged dedicated systems or matched
pairs. However, DOE has granted an
interim waiver for high-temperature
unit coolers that are distributed into
commerce without a paired condensing
system.44
Under the current test procedure,
these unit cooler-only models would be
tested according to the provisions in the
test procedure for unit coolers tested
alone, for which the AWEF calculation
requires an appropriate EER. DOE has
determined that the EER values for
medium- and low-temperature unit
coolers tested alone are not appropriate
for high-temperature applications
because this equipment operates with a
different suction dew point temperature,
and the dedicated condensing units
typically paired with medium- and lowtemperature units likely use different
compressor designs, which would have
different efficiencies.
As discussed in the April 2022 NOPR,
DOE calculated representative
compressor EER levels for wine cellar
walk-in unit coolers based on
compressor performance data collected
by DOE. 87 FR 23920, 23953. DOE used
42 All refrigerants have a ‘‘critical pressure’’ and
an associated ‘‘critical temperature’’ above which
liquid and vapor phases cannot coexist. Above this
critical point, the refrigerant will be a gas and its
temperature will increase or decrease as heat is
added or removed.
43 CO refrigeration systems are transcritical
2
because the high-temperature refrigerant that is
cooled by ambient air is in a supercritical state,
above the 87.8 °F critical point temperature, above
which the refrigerant cannot exist as separate vapor
and liquid phases.
44 DOE granted an interim waiver to LRC Coil
Company for specific basic models of unit cooleronly walk-in wine cellar refrigeration systems on
August 26, 2021. 86 FR 47631. (See also EERE–
2020–BT–WAV–0040, No. 1.) In reviewing another
petition for waiver and interim waiver from
Vinotheque for single-packaged system and
matched pair system basic models (Vinotheque,
EERE–2019–BT–WAV–0038, No. 6), DOE noted that
the manufacturer also offered unit cooler-only
systems distributed without a paired condensing
system.
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the calculated compressor EER levels to
develop different functions of EER for
three distinct capacities, as summarized
in Table III.4.
TABLE III.4—EER VALUES FOR HIGHTEMPERATURE COMPRESSORS AS A
FUNCTION OF CAPACITY FOR HIGHTEMPERATURE REFRIGERATION SYSTEMS
Capacity
(Btu/hr)
EER
(Btu/(W-h))
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<10,000 ...............
10,000–19,999 ....
20,000–36,000 ....
11.
(0.0007 × Capacity) + 4.
18.
The LRC Coil interim waiver includes
additional test procedure provisions to
obtain representations that are
representative for high-temperature unit
coolers, including both testing
requirements and AWEF calculation
requirements. 86 FR 47631. These
include provisions for testing ducted fan
coil unit evaporator systems. 86 FR
47631, 47635.
In the April 2022 NOPR, DOE
proposed to include provisions for
testing high-temperature unit coolers in
appendix C. 87 FR 23920, 23953. These
provisions, consistent with the LRC Coil
interim waiver, would include
conditions for testing these unit coolers
at high-temperature refrigeration
conditions, as well as the EER values in
Table III.4 for calculation of AWEF.
DOE also proposed to include these
provisions in appendix C1 in the April
2022 NOPR. Id. AHRI-Wine agreed with
DOE’s inclusion of high-temperature
unit cooler; however, they are
concerned with the suitability of the test
provisions and AWEF criteria. (AHRIWine, No. 30 at p. 2)
DOE notes that high-temperature unit
coolers have the same function as
medium- and low-temperature unit
coolers, however, their suction dew
point temperature differs, and
counterpart-dedicated condensing units
may use high-temperature compressors
designed for higher temperatures.
Therefore, DOE has concluded that the
same test procedure can be used for
low-, medium- and high- temperature
unit coolers, as long as the EER values
presented in Table III.4 are used for
high-temperature operation. After
consideration of stakeholder comments,
DOE is adopting the test procedure
provisions for high-temperature unit
coolers as proposed in the April 2022
NOPR. DOE is adding the new
requirements to appendix C, and will
also carry these provisions over to
appendix C1.
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AHRI also stated that rating hightemperature unit coolers alone without
a method to rate high-temperature
dedicated condensing units
disadvantages matched pairs and singlepackaged dedicated systems. (AHRI, No.
30 at p. 2) DOE will evaluate standards
for high-temperature equipment,
including any appropriate equipment
classes, in the ongoing walk-in energy
conservation standards rule making.
DOE’s evaluation of the wine cellar
market indicates that specific hightemperature dedicated condensing units
are rarely, if ever, sold outside of
matched-pair configurations. The
dedicated condensing units DOE has
encountered that are sold outside of a
matched-pair configuration and that
may be used in high-temperature
applications are general-purpose
condensing units often marketed for
medium- and high-temperature, or only
medium-temperature applications.
Based on the definition of walk-in
coolers (i.e., medium-temperature
refrigeration systems; see 10 CFR
431.302), DOE has determined that the
dedicated condensing units used for
high-temperature applications are
medium-temperature dedicated
condensing units. As such, these units
do not need to be certified for hightemperature applications but do need to
be certified for medium-temperature
applications.
G. Establishing Appendix C1 for
Refrigeration Systems
In the April 2022 NOPR, DOE
proposed to establish a new appendix
C1 to subpart R of part 431, which
would be required to demonstrate
compliance coincident with the
compliance date of any amended energy
conservation standards that DOE may
promulgate as part of a separate
standards rulemaking. 87 FR 23920,
23953.
As the changes included in appendix
C1 are expected to change measured
values for walk-ins, DOE is establishing
a new annual walk-in efficiency factor
metric, AWEF2, that will replace the
current metric, AWEF, once appendix
C1 is required for use. In many cases,
AWEF2 of a given refrigeration system
will not be the same as AWEF. For any
amended energy conservation standards
that DOE may promulgate as part of a
separate standards rulemaking, the
standards will be set based on AWEF2.
While AHRI 1250–2009 provides a
method for determining off-cycle fan
power, AHRI 1250–2020 includes offcycle power measurement for additional
auxiliary components (e.g., crankcase
heaters, pan heaters, and controls).
AHRI 1250–2020 also adds test
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procedures that allow for the testing of
single-packaged dedicated systems and
account for the thermal loss of these
systems. Taking into consideration the
additions just described, DOE has
determined that AHRI 1250–2020
improves representativeness and
expands the applicability of the walk-in
refrigeration system test procedure.
Additionally, DOE test procedures strive
to be consistent with industry test
methods. As AHRI 1250–2020 is the
most recent revision to the industry test
procedure for walk-in refrigeration
systems, it is the best representation of
current industry testing practices.
Therefore, DOE is incorporating AHRI
1250–2020 by reference into its test
procedure at appendix C1 for walk-in
refrigeration systems.
The test procedure changes that DOE
is adopting as a part of appendix C1 are
discussed in the following sections.
1. Off-Cycle Power Consumption
For walk-in refrigeration systems, the
term ‘‘off-cycle’’ refers to the period
when the compressor is not running and
defrost (if applicable) is not active.
During off-cycle, unit cooler fans and
other auxiliary equipment (crankcase
heater, receiver heater, etc.) 45 may
typically run or cycle on and off,
consuming energy. The DOE test
procedure currently accounts for only
unit cooler fan energy use during the
off-cycle period. 10 CFR part 431,
subpart R, appendix C, section 3.3.3.
Specifically, the current test procedure
requires manufacturers to measure the
integrated average off-cycle fan
wattage 46 for matched pairs and unit
coolers tested alone. Dedicated
condensing units tested alone use
default fan energy values rather than
tested values. 10 CFR part 431, subpart
R, appendix C, section 3.4.2.2. When
calculating AWEF, the unit cooler fans
are assumed to run at this average
integrated wattage throughout the entire
off-cycle duration. Id.
In the April 2022 NOPR, DOE
discussed the recommendation of the
ASRAC Working Group (Docket No.
45 A crankcase heater prevents refrigerant
migration and mixing with the crankcase oil when
the compressor is off by heating the crankcase of the
compressor. A receiver heater warms refrigerant in
the receiver to prevent flooded starts of the
compressor and cycling on low pressure to reduce
the potential for compressor damage. Both heaters
are used for outdoor dedicated condensing units in
colder climates.
46 Fans using periodic stir cycles are tested at the
greater of a 50 percent duty cycle or the
manufacturer’s default. Fans with two-, multi-, or
adjustable-speed controls are tested at the greater of
50% fan speed or the manufacturer’s default fan
speed. Fans with no controls are tested at their
single operating point. (See 10 CFR part 431,
subpart R, appendix C, section 3.3.3.)
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EERE–2015–BT–STD–0016, No. 56,47
Recommendation #6) to revise the offcycle test procedure to account for all
other components that consume energy
during the off-cycle, such as pan
heaters, crankcase heaters, and controls.
87 FR 23920, 23953. DOE noted that
AHRI 1250–2020 includes a method for
determining energy consumption during
off-cycle for many of these components.
Id.
DOE is adopting the off-cycle
procedure in sections C3.5, C4.2, and
Table C3 in AHRI 1250–2020 with some
modifications. The following sections
describe DOE’s modifications to the offcycle test method and metric in more
detail.
a. Off-Cycle Test Duration and
Repetition
The current DOE test procedure
references the 30-minute off-cycle test
duration prescribed in section C3.6 of
AHRI 1250–2009. AHRI 1250–2020 was
updated to include two off-cycle test
durations: (1) 30 minutes for evaporator
fans and ancillary equipment with
controls that are time-varying or
respond to ambient or refrigerant
temperatures (e.g., a crankcase heater or
fan cycling control), and (2) 5 minutes
for evaporator fans and ancillary
equipment without such controls.
DOE has concluded that these
durations balance the need to minimize
test burden with the need for an
accurate and representative test method.
In the April 2022 NOPR, DOE proposed
to reference these test durations. 87 FR
23920, 23954.
AHRI 1250–2020 also added two sets
of test repetition requirements: one for
evaporator fans and ancillary equipment
with controls that are time-varying or
respond to ambient or refrigerant
temperatures (e.g., a crankcase heater or
fan cycling control), and one for
evaporator fans and ancillary equipment
without such controls. For the former,
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AHRI 1250–2020 requires that the offcycle test for each applicable load
point 48 consists of three initial test
cycles, with the potential for three
supplemental cycles. As discussed in
the April 2022 NOPR, AHRI 1250–2020
only requires the three supplemental
tests if the integrated power of the first
three cycles is not within 2 percent of
the average of the first three cycles. 87
FR 23920, 23954. If the same variation
occurs for the supplemental test cycles,
then AHRI 1250–2020 requires that offcycle power be reported as the
maximum value of all six integrated
power readings. Alternatively, for
equipment lacking evaporator fans and
ancillary equipment controls, AHRI
1250–2020 requires measuring
integrated power over a single cycle. A
summary of test durations and fan
settings based on fan control
configuration and ancillary equipment
control configuration is listed in Table
III.5.
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TABLE III.5—OFF-CYCLE TEST SETTINGS AND DURATIONS
Fan control configuration
Ancillary equipment control
configuration
Fan setting for test
No Control ...........................
No Control ...........................
User-Adjustable Speed Controls.
User-Adjustable Speed Controls.
User-Adjustable Stir Cycles
No Control .........................
With Control .......................
No Control .........................
Non-User Adjustable Controls.
With or Without Control .....
Default setting, as shipped ............................................
Default setting, as shipped ............................................
The greater of 50% fan speed or the manufacturer’s
default fan speed.
The greater of 50% fan speed or the manufacturer’s
default fan speed.
The greater of a 50% duty cycle or the manufacturer
default..
Default setting, as shipped ............................................
With Control .......................
With or Without Control .....
Test duration
5 minutes.
30 minutes.
5 minutes.
30 minutes.
The greater of 30 minutes
or three full ‘‘stir cycles.’’
30 minutes.
DOE has concluded that the repetition
requirements specified by AHRI 1250–
2020 are adequate and not overly
burdensome. If the variance is small
among the first three cycles, then the
testing burden is reduced by not
requiring any more cycles. If variance
exceeds 2 percent of the average when
three additional cycles are taken, then
the conservative approach is taken by
reporting the maximum integrated
power reading, and test burden is
reduced by not requiring additional
tests. In the April 2022 NOPR, DOE
proposed to adopt the repetition
requirements included in AHRI 1250–
2020. 87 FR 23920, 23954.
In response to the off-cycle test
durations and repetitions proposed in
the April 2022 NOPR, the Efficiency
Advocates stated that they supported
updating off-cycle testing to include a
unit’s total input wattage. (Efficiency
Advocates, No. 37 at p. 1) Lennox
supported DOE proposals regarding offcycle test duration and repetition.
(Lennox, No. 35 at pp. 4–5) In this final
rule, DOE is adopting the off-cycle test
duration and repetition test procedures
as proposed.
In the April 2022 NOPR, DOE
proposed to adopt Section C3.5 of AHRI
1250–2020 to establish off-cycle data
collection requirements in the DOE test
procedure. 87 FR 23920, 23955. AHRI
1250–2020 excludes the first 10 minutes
that follow the termination of the
compressor on-cycle interval from the
general operating tolerances (indoor/
outdoor temperatures and power
readings) established for the on-cycle
steady state test because during this
time period, the test room conditioning
equipment is transitioning from steady
state on-cycle operation into off-cycle
operation.
Additionally, AHRI 1250–2020
requires that the minimum data
collection rate be increased (with
respect to steady-state requirements)
from 30 to 60 test readings per hour for
temperature measurements and
condensing unit electric power
measurements, and from 3 to 60 test
readings per hour for unit cooler electric
power measurements. AHRI 1250–2020
also requires that off-cycle power
measurements be integrated and
averaged over the recording interval
with a sampling rate of no less than 1
second unless an integrating watt/hour
meter is used.
In response to the April 2022 NOPR,
Lennox commented that it supports
DOE’s off-cycle power measurement
proposals but requested clarification on
47 Appliance Standards and Rulemaking Federal
Advisory Committee Refrigeration Systems Walk-in
Coolers and Freezers Term Sheet, available at
www.regulations.gov/document/EERE-2015-BTSTD-0016-0056.
48 Off-cycle load points are discussed later in this
section.
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b. Off-Cycle Operating Tolerances and
Data Collection Rates
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unit cooler ‘‘steady-state ambient
conditions,’’ specifically whether 35 °F
and –10 °F for unit cooler refers to air
entering dry-bulb in Tables 16 and 17 of
AHRI 1250–2020. (Lennox, No. 35 at pp.
4–5) DOE clarifies that the unit cooler
‘‘steady-state ambient conditions’’ of
35 °F and –10 °F refer to the entering air
dry-bulb temperatures of mediumtemperature and low-temperature unit
coolers, respectively. DOE did not
receive any additional comments on this
topic and is adopting section C3.5 of
AHRI 1250–2020 for off-cycle operating
tolerances and data collection
requirements, as proposed.
c. Off-Cycle Load Points
Currently, the DOE test procedure
specifies measuring off-cycle evaporator
fan power and provides no ambient
condition detail; however, DOE expects
that the integrated power of ancillary
equipment may vary with ambient
conditions depending on the
refrigeration system design.
Consequently, in the April 2022 NOPR,
DOE proposed that the off-cycle power
test described in section III.G.1.a of this
document be run at each steady-state
ambient test condition as specified in
Tables 4 through 17 of AHRI 1250–2020.
87 FR 23920, 23955. Accordingly, DOE
proposed that refrigeration systems with
dedicated condensing units located
indoors would evaluate off-cycle power
at a single outdoor ambient condition
(90 °F dry-bulb), while systems with
dedicated condensing units located
outdoors would determine off-cycle
power at three ambient conditions
(95 °F, 59 °F, and 35 °F dry-bulb). The
measured integrated off-cycle power
results would then be used to calculate
AWEF2, as described in the following
section.
In response to the April 2022 NOPR,
KeepRite commented that the benefit
from additional off-cycle power tests is
minimal, capturing less than 1 percent
of total system energy. (KeepRite, No. 36
at p. 3) DOE acknowledges that off-cycle
power tests account for significantly less
energy consumption than on-cycle tests.
However, DOE’s testing using the three
ambient temperature off-cycle load
points in AHRI 1250–2020 has
measured up to 60 percent more offcycle power use than the off-cycle
power measurements in the current test
procedure. This result indicates that the
current test procedure does not fully
represent off-cycle power use for walkin refrigeration systems.
HTPG disagreed with the additional
off-cycle testing requirement proposed
in the April 2022 NOPR (HTPG, No. 32
at p. 6) and stated that it would increase
test burden. (HTPG, No. 32 at p. 8)
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AHRI-Wine stated that they expect the
change related to off-cycle power
measurement requirements will increase
test burden. (AHRI-Wine, No. 30 at p. 3)
DOE acknowledges that adopting the
off-cycle power measurements in AHRI
1250–2020 may incrementally increase
test time. However, in its testing, DOE
has found that conducting off-cycle
power measurements accounts for less
than 10 percent of the overall setup and
test duration for walk-in refrigeration
systems.
Lennox stated that using a single
condition to measure off-cycle power
may not be sufficient for indoor
matched systems. (Lennox, No. 35 at p.
5) Lennox also recommended working
with industry to establish running
conditions for equipment that is not part
of a matched pair. Id. DOE notes that the
number and specified conditions of offcycle tests correspond to the number
and specified conditions of the
refrigeration capacity tests that are run
for each unit. Outdoor units have three
capacity tests and three ambient
conditions to represent the three
ambient conditions that the unit would
be exposed to, therefore they have three
off-cycle tests. Indoor units have one
capacity test at one ambient condition
that the unit would be exposed to,
therefore they have one off-cycle test.
The ambient conditions inside the walkin box do not fluctuate and therefore
one ambient condition is representative
for both on-cycle and off-cycle tests.
DOE has concluded that this is the most
appropriate approach to balance test
procedure consistency and test burden.
DOE is adopting the off-cycle test
points for (1) the A test specified in
AHRI 1250–2020 for fixed-capacity
refrigerator and freezer matched-pair
and dedicated condensing units located
indoors, (2) the A, B, and C tests
specified in AHRI 1250–2020 for
refrigerator and freezer matched-pair
and dedicated condensing units located
outdoors, and (3) the A test specified in
AHRI 1250–2020 for refrigerator and
freezer unit coolers. DOE clarifies that a
single off-cycle test is representative for
both split-system unit coolers and
indoor matched systems.
d. AWEF2 Calculations
In the April 2022 NOPR, DOE
proposed to adopt the off-cycle
calculations in AHRI 1250–2020, which
replace integrated off-cycle evaporator
fan power with the combined integrated
off-cycle power from the unit cooler and
condensing unit in each equation. 87 FR
23920, 23955. Additionally, DOE
proposed to adopt the off-cycle
calculations in AHRI 1250–2020, which
replace integrated off-cycle fan power
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with integrated off-cycle power in the
unit cooler equation. Id. This aspect of
the unit cooler test method is consistent
with the current method specified in
appendix C to subpart R of 10 CFR part
431.
For outdoor refrigeration systems,
DOE proposed to deviate from the AHRI
1250–2020 calculations for off-cycle
energy use in the April 2022 NOPR. 87
FR 23920, 23955. DOE notes that the
AHRI 1250–2020 equations for average
refrigeration system total power input
for bin temperature Tj, (e.g., Equation
13), do not appear to use off-cycle
power values for the unit cooler and/or
the condensing unit that vary with Tj. In
fact, there are no equations providing
the off-cycle power for either
component as a function of Tj in section
7 of AHRI 1250–2020, such as there are
for net capacity and on-cycle power
input (e.g., Equations 14 through 17).
Since the off-cycle power may vary as
a function of outdoor temperature as
discussed previously, DOE proposed in
the April 2022 NOPR to adopt
instructions for calculating off-cycle
power as a function of outdoor
temperature based on the measurements
made at the three outdoor test condition
temperatures. 87 FR 23920, 23955–
23956.
For condensing unit off-cycle power,
DOE proposed in the April 2022 NOPR
to require that off-cycle power for Tj less
than or equal to 35 °F would be equal to
the power measured for the test
condition C off-cycle power test. 87 FR
23920, 23956. For Tj higher than 95 °F,
DOE proposed that that off-cycle power
would be equal to the power measured
for the test condition A off-cycle power
test. Id. Between these two
temperatures, DOE proposed that
condensing unit off-cycle power would
be determined based on the test
condition B and C measurements when
Tj is below 59 °F, and based on the A
and B measurements when it is above
59 °F, similar to Equations 14 through
17 for on-cycle capacity and power in
AHRI 1250–2020. Id.
For unit cooler off-cycle power, DOE
proposed in the April 2022 NOPR that
the three unit cooler off-cycle power
measurements taken when testing a
matched-pair or single-packaged
dedicated system would be averaged,
and that the resulting average, with no
dependence on Tj, would be used in the
AWEF2 calculations. Id.
DOE requested comment on its
proposals to align the test procedures
for appendix C1 with AHRI 1250–2020,
except for the use of off-cycle power
measurements in the AWEF2
calculations for dedicated condensing
units, matched pairs, and single-
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packaged dedicated systems intended
for outdoor installation. Id. DOE also
requested comment on its proposals to
use three sets of unit cooler and outdoor
dedicated condensing unit off-cycle
measurements in the AWEF
calculations. Id.
In response, KeepRite stated that the
AWEF2 calculations could be nonrepresentative depending on what
temperature the crankcase heater turns
on and recommended an option for
constant crankcase heater power below
the 35 °F test bins. (KeepRite, No. 36 at
p. 3) DOE notes that the proposed
AWEF2 calculations are incorporated
from AHRI 1250–2020. DOE notes that
industry agreed to these calculations
during the development of AHRI 1250–
2020; therefore, DOE will not consider
alternative calculations for representing
off-cycle dedicated condensing unit
power at this time.
RSG recommended that DOE further
define off-cycle unit cooler fan speed as
either 50 percent of full speed or the
factory low speed setting (if the lowspeed setting is less than 50 percent and
not adjustable by the end user). (RSG,
No. 41 at p. 5) DOE notes that section
4.2 of Appendix C to AHRI 1250–2020
states that for variable-speed unit cooler
fan controls, the greater of 50 percent
fan speed or the manufacturer’s default
fan speed shall be used for measuring
off-cycle fan energy. Since this is the
test practice agreed on by industry, DOE
is not allowing fan speeds of less than
50 percent for off-cycle unit cooler
testing in this final rule.
Lennox stated that the test procedure
requires three measurements at different
ambient conditions for matched-pair
and single-packaged dedicated systems
but does not explicitly state what to do
for split-system unit coolers. (Lennox,
No. 35, at p. 5) Additionally, Lennox
stated that a single test condition may
not be sufficient for split-system unit
coolers. Id. DOE clarifies that for
matched-pair and single-packaged
dedicated systems located outdoors,
there are three ambient conditions at
which the dedicated condensing system
is tested, therefore there are three
corresponding off-cycle unit cooler
power measurements. These off-cycle
test conditions are specified in Tables 5
and 9 of AHRI 1250–2020 for fixedcapacity matched pairs. AWEF2 is
calculated as the average of these three
measurements since these
measurements should not vary with
ambient temperature. For split-system
unit coolers tested alone, there is no
component exposed to outdoor ambient
conditions, therefore there is only one
condition at which the unit cooler is
tested and one corresponding off-cycle
power measurement. These conditions
are listed in Tables 16 and 17 of AHRI
1250–2020. As there is only one
ambient condition at which the unit
cooler is tested, DOE believes that the
single off-cycle measurement is
sufficient for split-system unit coolers.
In this final rule, DOE is adopting the
procedures as proposed in the April
2022 NOPR into appendix C1.
2. Single-Packaged Dedicated Systems
a. AHRI 1250–2020 Methods for Testing
As discussed in the April 2022 NOPR,
the Direct Expansion (‘‘DX’’) dual
instrumentation method is impractical
for testing single-packaged dedicated
systems. 87 FR 23920, 23958. AHRI
1250–2020 expanded methods of test for
single-packaged dedicated systems to
include air enthalpy, calorimetry, and
compressor calibration. Specifically,
AHRI 1250–2020 incorporates the
following test procedures by reference:
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(1) Air enthalpy method: ASHRAE
37–2009, ‘‘Methods of Testing for Rating
Electrically Driven Unitary AirConditioning and Heat-Pump
Equipment,’’ and ANSI/ASHRAE 41.6–
2014, ‘‘Standard Method for Humidity
Measurement’’;
(2) Calorimeter methods: ASHRAE
16–2016, ‘‘Method of Testing for Rating
Room Air Conditioners, Packaged
Terminal Air Conditioners, and
Packaged Terminal Heat Pumps for
Cooling and Heating Capacity’’; and
(3) Compressor calibration methods:
ASHRAE 37–2009, ‘‘Methods of Testing
for Rating Electrically Driven Unitary
Air-Conditioning and Heat-Pump
Equipment,’’ and ANSI/ASHRAE 23.12010, ‘‘Methods of Testing for Rating the
Performance of Positive Displacement
Refrigerant Compressors and
Condensing Units that Operate at
Subcritical Temperatures of the
Refrigerant.’’
AHRI 1250–2020 requires two
simultaneous measurements of system
capacity (i.e., a primary and a secondary
method) for single-packaged dedicated
systems, and section C9.2.1 of AHRI
1250–2020 requires that the
measurements agree within 6 percent.
Table C4 in AHRI 1250–2020 specifies
which test methods (calorimeter, air
enthalpy, compressor calibration)
qualify as primary and/or secondary
methods. However, as summarized in
Table III.6, DOE is adopting the method
of test and the test hierarchy table in
AHRI 1250–2020 with one
modification—the addition of a singlepackaged refrigerant enthalpy method.
DOE is adopting this change to support
testing of multi-circuit single-packaged
dedicated systems, which is discussed
in detail in section III.G.2.f of this
document.
TABLE III.6—SINGLE-PACKAGED SYSTEM TEST METHODS AND TEST HIERARCHY
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Method of test
Test hierarchy
Balanced Ambient Indoor Calorimeter ............................................................................................
Balanced Ambient Outdoor Calorimeter .........................................................................................
Indoor Air Enthalpy ..........................................................................................................................
Indoor Room Calorimeter ................................................................................................................
Single-packaged Refrigerant Enthalpy 49 ........................................................................................
Outdoor Room Calorimeter .............................................................................................................
Outdoor Air Enthalpy .......................................................................................................................
Compressor Calibration ...................................................................................................................
Primary.
Primary or Secondary.
Primary or Secondary.
Primary or Secondary.
Secondary.
Secondary.
Secondary.
Secondary.
b. Waivers
As discussed in the April 2022 NOPR,
DOE granted a waiver to Store It Cold
for single-packaged dedicated systems
single-packaged dedicated systems.50
The alternate test methods included in
each of these waivers require the
49 As
described in section III.G.2.f of this
document, this method of test does not apply to
CO2 single-packaged units.
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on August 9, 2019. 87 FR 23920, 23956.
DOE also granted waivers to Air
Innovations, CellarPro, Vinotemp, and
Vinotheque for walk-in refrigeration
systems used in wine cellar
applications, where some of the basic
models included in these waivers were
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50 Table III.1 lists the manufacturers that have
received a test procedure waiver or interim waiver
for walk-in refrigeration systems designed for wine
cellar applications.
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specified basic models to be tested in
accordance with the air enthalpy
methods specified in ASHRAE 37–2009
for testing single-packaged dedicated
systems, which is now referenced by
AHRI 1250–2020. Additionally, DOE
granted an interim waiver to RSG for
multi-circuit single-packaged dedicated
systems (‘‘the RSG waiver’’). 87 FR
43808. The alternate test method
included in that waiver is further
discussed in sections III.G.2.d through
III.G.2.f of this document.
In appendix C1, DOE is referencing
the methods of test for single-packaged
dedicated systems from section C9 of
AHRI 1250–2020, with some
modifications. Since appendix C1 will
be required on the compliance date of
any amended energy conservation
standards, were such standards to be
adopted, the current test procedure
waivers for specified single-packaged
basic models will expire on the
compliance date of appendix C1.
c. Suitability of the Single-Packaged
Test Methods in AHRI 1250–2020
In the April 2022 NOPR, DOE
discussed the suitability of the AHRI
1250–2020 test methods for singlepackaged dedicated systems. 87 FR
23920, 23957. Specifically, DOE
discussed stakeholder feedback from the
June 2021 RFI that freezing of the
calorimetry loop and the need for a
pressure equalizing device on the test
chamber are potential issues with the
ASHRAE 16–2016 calorimeter method.
DOE has tested multiple singlepackaged dedicated systems at multiple
labs and did not observe freezing of the
calorimetry loop. Therefore, DOE has
determined that the ASHRAE 16–2016
calorimetry methods are suitable for
testing single-packaged dedicated
systems. Furthermore, DOE concluded
that the equalizer device for calorimeter
room testing, which is required in
ASHRAE 16–2016, is not necessary for
the testing of single-packaged dedicated
systems. As a result, DOE did not
propose to require an equalizer device
for calorimeter room testing in the April
2022 NOPR. Id. Therefore, in the April
2022 NOPR, DOE proposed to adopt the
ASHRAE 16–2016 methods of test as
referenced in AHRI 1250–2020 to
provide flexibility to manufacturers.
DOE further discussed in the April
2022 NOPR that its testing on singlepackaged dedicated systems using the
room calorimeter and air enthalpy
methods as described in AHRI 1250–
2020 appropriately accounted for the
thermal losses that are typical for this
equipment. Id. DOE additionally noted
that while there may not be extensive
experience applying these test methods
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to walk-in refrigeration systems, all the
proposed test methods have been
evaluated and are used extensively for
testing other heating, ventilation, and
air-conditioning (‘‘HVAC’’) equipment.
Id. Therefore, in the April 2022 NOPR,
DOE tentatively determined that these
methods are representative of singlepackaged dedicated system energy use
and proposed to adopt the singlepackaged dedicated system test
procedure in AHRI 1250–2020 with the
modifications outlined in sections
III.G.2.d and III.G.2.e of this document.
Id.
In response to the April 2022 NOPR,
the CA IOUs commented that they
support DOE including a test method for
single-packaged dedicated systems. (CA
IOUs, No. 42 at p. 6) Based on DOE’s
experience testing this equipment and
the comments received, DOE is adopting
the test procedures for single-packaged
dedicated systems in AHRI 1250–2020
as proposed in the April 2022 NOPR
into appendix C1.
d. Single-Packaged Refrigerant Enthalpy
Method
In the April 2022 NOPR, DOE
proposed to adopt a single-packaged
refrigerant method similar to the
alternate test procedure outlined in
RSG’s waiver request. 87 FR 23920,
23958. On July 22, 2022, DOE issued an
interim waiver to RSG for testing singlepackaged dedicated systems with
multiple refrigeration circuits using a
modified refrigerant enthalpy method.
87 FR 43808.
As previously discussed, AHRI 1250–
2020 includes four potential primary
and six potential secondary test
methods for testing single-packaged
dedicated systems (see Table C4 in
AHRI 1250–2020). The refrigerant
enthalpy method is not included in
these lists. The procedure that DOE
proposed to adopt in the April 2022
NOPR uses the refrigerant-side
measurements of the DX calibrated box
method in section C8 of AHRI 1250–
2020 while simultaneously using one of
the ‘‘primary’’ methods listed in Table
C4 in AHRI 1250–2020 for singlepackaged methods of test as an air-side
measurement. The details of the primary
test methods were discussed in the
April 2022 NOPR. 87 FR 23920, 23958.
In the April 2022 NOPR, DOE
requested comment on its proposed
procedure for testing single-packaged
dedicated systems. AHRI recommended
allowing DX dual instrumentation
testing, since requiring air-side enthalpy
testing would impose considerable test
burden on test labs that do not have airside measurement capacity. (AHRI, No.
30 at p. 7) Lennox stated that it can
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support the proposed refrigerant
enthalpy approach as a secondary
approach but recommended that the DX
dual instrumentation method be
maintained as an option. (Lennox, No.
35 at p. 5) Lennox also commented that
requiring the air enthalpy test method
would impose significant test burden.
Id. In response to the recommendation
by Lennox to maintain the DX dual
instrumentation method, DOE’s testing,
in addition to the information received
in the waivers for testing of singlepackaged dedicated systems, indicates
that the DX dual instrumentation
method is inappropriate for singlepackaged units because the internal
volume of the added liquid line and
mass flow meters adds substantially to
the required refrigerant charge, and the
entire assembly adds substantial
pressure drop.51 However, DOE notes
that the DX dual instrumentation
method continues to be an accurate test
method for dedicated condensing units
tested alone. Additionally, in response
to Lennox’s comment regarding the
burden associated with the air enthalpy
method, DOE has determined that the
representativeness achieved through
this method outweighs the additional
burden.
AHRI and Lennox commented that
piercing a refrigeration system to use the
refrigerant enthalpy as a secondary
check may not duplicate the primary
result. (AHRI, No. 30 at p. 7; Lennox,
No. 35 at p. 5) HTPG disagreed with the
proposal to use the refrigerant enthalpy
test for single-packaged dedicated units,
as they are critically charged and
piercing their lines could affect
measured capacity. (HTPG, No. 32 at p.
6) The proposed procedure requires a
primary test to be completed before the
system is pierced. The capacity
measured from the primary test would
be compared to the capacity measured
from the secondary test to ensure that
the capacity is not affected from
piercing the refrigeration system. Based
on its testing, DOE has determined that
a secondary test that does not materially
alter the system operation would
duplicate, and serve as a check for, the
primary test. DOE also notes that there
are secondary test options provided in
Table C4 of AHRI 1250–2020 that do not
require piercing of the refrigerant lines.
Lennox also stated that the refrigerant
enthalpy test should be allowed to
penetrate the system for the primary test
since the secondary test would require
the system to be penetrated. (Lennox,
No. 35 at p. 5) DOE interprets this
comment to be a request to allow the DX
51 See Store It Cold Decision and Order, 84 FR
39286, 39287 (Aug. 9, 2019).
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dual instrumentation test, or other
refrigerant enthalpy tests, as a primary
test for single-packaged dedicated
systems. As discussed previously, DOE
has concluded that the DX dual
instrumentation test is not
representative for single-packaged
dedicated systems because it does not
account for thermal losses. DOE
reiterates that the purpose of the
primary test, conducted prior to
penetration of the refrigerant system, is
to compare the primary and secondary
results to ensure that the system is not
affected from penetrating the liquid
lines.
AHRI-Wine stated that they do not
support the proposed refrigerant
enthalpy test procedure because they do
not see an advantage unless the method
is used in parallel with others. (AHRIWine, No. 30 at p. 3) DOE notes that the
single-packaged refrigerant enthalpy test
procedure would be used only as a
secondary test when paired with one of
the primary options provided in Table
C4 of AHRI 1250–2020.
RSG agreed with DOE’s proposed test
procedure. (RSG, No. 41 at p. 2) DOE is
adopting the single-packaged refrigerant
enthalpy test method as a secondary test
as proposed in the April 2022 NOPR
into appendix C1.
e. Calibrated Box Method for SinglePackaged Dedicated Systems
In the RSG waiver DOE allowed RSG
to use a modified version of the
calibrated box method. 87 FR 43808,
43813–43814. As discussed in the
notification of interim waiver, the
modified calibrated box method
involves mounting the system on the
calibrated box, like its installation on a
walk-in for field use and exchanging air
with the box interior to cool it. 87 FR
43808, 43812. The exterior of the
calibrated box would be conditioned
such that the air conditions entering the
single-packaged dedicated system
condenser match the specified targets.
The warm condensing unit portion of
the single-packaged dedicated system
and its condenser discharge air may in
some cases add to the thermal load
imposed on the calibrated box. The
interim waiver therefore provided
additional optional test methods to
quantify this additional thermal load on
the calibrated box, and to adjust for it
in the determination of system capacity.
Determining the additional thermal load
requires temperature sensors mounted
on the box exterior surface for box
calibration and box load determination,
rather than measuring air temperature
just outside the box (the approach
described for the calibrated box method
in section C8 of AHRI 1250–2020).
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Since the modified calibrated box
method accounts for the thermal losses
associated with single-packaged
dedicated systems and is very similar to
the indoor room calorimeter method,
DOE tentatively determined in the RSG
waiver that it would be appropriate for
the calibrated box method to be a
primary test method (i.e., the capacity
determined from this method would be
used for rating purposes) 87 FR 43808,
43812. DOE proposed to adopt the
method described in the RSG waiver in
the April 2022 NOPR. Id. A full
discussion of the test procedures
proposed by RSG are discussed in the
interim waiver notification. Id.
As mentioned previously, DOE
received no stakeholder comments on
the RSG waiver. Therefore, DOE is
adopting the test provisions outlined in
the RSG waiver in addition to the test
provisions for single-packaged
dedicated systems proposed in the April
2022 NOPR.
f. Multi-Circuit Single-Packaged
Dedicated Systems
As discussed in the April 2022 NOPR,
neither the current DOE test procedure
nor AHRI 1250–2020 provides a method
for testing single-packaged dedicated
systems with multiple refrigeration
circuits. As previously discussed, DOE
granted RSG an interim waiver for
testing multi-circuit single-packaged
dedicated systems. 87 FR 43808. This
test procedure is based on the singlepackaged refrigerant enthalpy method
discussed in section III.G.2.d of this
document. The procedure is duplicated
for each refrigeration circuit contained
in the unit such that each circuit returns
mass flow, enthalpy in, and enthalpy
out values. The resultant mass flow and
enthalpy values are used to calculate the
gross refrigeration capacity for each
circuit. Each circuit’s gross capacity is
then summed to determine the total
capacity of the system.
In the April 2022 NOPR, DOE
tentatively determined that the alternate
approach would provide a reasonable
method for determining the capacity of
multi-circuit single-packaged dedicated
systems. 87 FR 23920, 23958. However,
DOE had also determined the approach
may not adequately capture the heat
loss associated with single-packaged
dedicated systems; therefore, DOE
proposed to adopt the test procedures in
section C8 of AHRI 1250–2020 for
testing single-packaged dedicated
systems, with the additional
requirement that the primary test would
be an indoor air refrigeration capacity
test where the allowable refrigeration
capacity heat balance is 6 percent. Id.
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In response to the April 2022 NOPR,
HTPG commented that it agreed with
DOE’s proposal for testing multi-circuit
single-packaged dedicated systems.
(HTPG, No. 32 at p. 6) DOE is adopting
the test procedure as proposed in the
April 2022 NOPR into appendix C1.
g. CO2 Single-Packaged Dedicated
Systems
As discussed in the April 2022 NOPR,
the current DOE test procedure for
single-packaged dedicated systems does
not provide representative values for
single-packaged dedicated systems that
use CO2 as a refrigerant. 87 FR 23920,
23959. However, the single-packaged
dedicated system test methods in AHRI
1250–2020 use air enthalpy
measurements and do not require any
refrigerant mass flow measurements. In
the April 2022 NOPR, DOE proposed
that single-packaged dedicated systems
that use CO2 as a refrigerant be tested
using the test methods for singlepackaged dedicated systems outlined in
AHRI 1250–2020. Id.
In response, HTPG stated that it
agreed with DOE’s proposal for the air
enthalpy test procedure for CO2 singlepackaged dedicated systems. (HTPG,
No. 32 at p. 6) DOE is adopting the test
as proposed in the April 2022 NOPR
into appendix C1.
3. Detachable Single-Packaged
Dedicated Systems
As discussed in section III.A.2.g, DOE
is aware of refrigeration systems that are
installed with the evaporator unit
exchanging air through the wall or
ceiling of the walk-in, but with the
condensing unit installed remotely and
connected to the evaporator with
refrigerant lines. DOE has defined this
equipment as a ‘‘detachable singlepackaged dedicated system.’’ Neither
appendix C nor AHRI 1250–2020
contain provisions for testing detachable
single-packaged dedicated systems. DOE
is aware that, currently, detachable
single-packaged dedicated systems may
be tested either with the condensing
unit and unit cooler housings separated
or mounted adjacent to each other, the
latter of which is the more common
arrangement for single-packaged
dedicated systems. Testing in the latter
arrangement would account for the heat
loss of the evaporator installation, and
any additional heat loss from the
condensing unit being mounted to the
evaporator unit; therefore, in the April
2022 NOPR, DOE proposed as part of
the new appendix C1 and 10 CFR
429.53(a)(2)(i)(C) that detachable singlepackaged dedicated systems would be
tested using the test procedure for
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single-packaged dedicated systems. 87
FR 23920, 23959.
HTPG and Lennox agreed with the
proposal. (HTPG, No. 32 at p. 6; Lennox,
No. 35 at p. 5) AHRI, on behalf of wine
cellar manufacturers stated that the
proposal is sufficient. (AHRI-Wine, No.
30 at p. 4) RSG agreed with the proposal
if the calibrated box method is included
in allowable test methods. (RSG, No. 41
at p. 2) As discussed in section III.G.2.e,
DOE is adopting the test provisions
outlined in the interim waiver granted
to RSG in July 2022. These include a
calibrated box test procedure for singlepackaged dedicated systems.
AHRI stated that the current test
procedure is sufficient. (AHRI, No. 30 at
p. 8) DOE interprets this comment as
AHRI stating that the DX dual
instrumentation method is sufficient for
detachable single-packaged dedicated
units. As discussed in section III.G.2.d,
DOE’s testing, in addition to
information received in waivers for
testing of single-packaged dedicated
systems, indicates that the DX dual
instrumentation method is
inappropriate for single-packaged units.
Since detachable single-packaged
dedicated systems have thermal losses
similar to those for single-packaged
dedicated systems, DOE is adopting the
test procedure for detachable singlepackaged dedicated systems as
proposed in the April 2022 NOPR (87
FR 23920, 23959) into appendix C1.
AHRI-Wine also requested
clarification for whether wine cellar
manufacturers must test all
configurations or the most common if
multiple configurations apply to a single
system. (AHRI-Wine, No. 30 at p. 2) The
definition of ‘‘detachable singlepackaged dedicated system’’ that DOE is
adopting in this final rule states that it
is a system that can be configured as
either a split system or as a singlepackaged dedicated system. Based on
the procedure DOE is adopting, such a
system would be tested as a singlepackaged dedicated system.
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4. Attached Split Systems
As discussed in section III.A.2.f, DOE
is aware of refrigeration systems that are
sold as matched systems and
permanently attached to each other with
beams. In this final rule, DOE is
defining these systems as ‘‘attached split
systems.’’ DOE has confirmed through
testing that these systems still
experience some heat leakage when
compared to traditionally installed
systems that have the dedicated
condensing unit and the unit cooler in
separate housings. However, this heat
leakage has not been studied extensively
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and DOE is aware that it may be
difficult to calculate.
DOE proposed in the April 2022
NOPR testing attached split systems as
a matched pair using refrigerant
enthalpy methods. 87 FR 23920, 23959.
HTPG agreed with the proposal. (HTPG,
No. 32 at p. 7) In this final rule, DOE
is adopting the test procedure as
proposed in the April 2022 NOPR into
appendix C1 and 10 CFR
429.53(a)(2)(i)(D).
5. Systems for High-Temperature
Freezer Applications
As discussed in the April 2022 NOPR,
DOE recognizes that testing hightemperature freezer refrigeration
systems at a consistent test condition is
important to ensure test procedure
consistency and to provide comparable
performance values in the market. 87 FR
23920, 23961. DOE acknowledges that
testing high-temperature freezer
refrigeration systems at a temperature
less than 35 °F would be more
representative of their actual energy use;
however, it is not clear if the potential
additional test burden justifies
including an additional test condition
for walk-in cooler refrigeration systems.
Therefore, in the April 2022 NOPR, DOE
determined that medium-temperature
dedicated condensing units used in
high-temperature freezer applications
would continue to be tested according
to appendix C. Id.
In response to the April 2022 NOPR,
HTPG stated that it agreed with DOE
continuing to test high-temperature
freezers in accordance with appendix C.
(HTPG, No. 32 at p. 7) The Efficiency
Advocates encouraged DOE to establish
a standardized rating temperature for
high-temperature freezers that is below
35 °F, since it is more characteristic of
the temperature that these products
operate between. (Efficiency Advocates,
No. 37 at p. 3) As discussed in the April
2022 NOPR, DOE acknowledges that
testing high-temperature freezer
refrigeration systems at a temperature
less than 35 °F would be more
representative of their actual energy use;
however, doing so would require an
additional test condition. At this time,
DOE does not think the relatively small
gain in representativeness that this
additional test condition would provide
justifies the additional test burden for
evaluating the performance of walk-in
cooler refrigeration systems. Therefore,
DOE is maintaining its determination to
keep testing systems for hightemperature freezer applications as
medium-temperature systems.
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6. Systems for High-Temperature
Applications
As discussed previously in section
III.A.2.c, DOE is aware of wine cellar
(high-temperature) refrigeration systems
that fall within the definition of ‘‘walkin’’ but operate at a temperature range
of 45 °F to 65 °F and, therefore, are
incapable of being tested in a manner
that would yield a representative
average use cycle under the current
version of the walk-in test procedure.
DOE has granted waivers or interim
waivers to the manufacturers listed in
Table I.1 for an alternate test procedure
for specific basic models of singlepackaged dedicated systems, matched
pair, and unit cooler-only hightemperature refrigeration systems.
In the April 2022 NOPR, DOE
proposed to include provisions for
testing and rating high-temperature
matched-pair systems that specify an air
entering dry-bulb temperature of 55 °F.
87 FR 23920, 23961. DOE also proposed
to test high-temperature refrigeration
systems that are single-packaged
dedicated systems using one of the
following methods, as specified in Table
C4 of AHRI 1250–2020: indoor air
enthalpy, outdoor air enthalpy,
compressor calibration, indoor room
calorimeter, outdoor room calorimeter,
balanced ambient indoor calorimeter, or
balanced ambient outdoor calorimeter.
Id.
In response to the April 2022 NOPR,
the Efficiency Advocates commented
that they support adding unique test
procedures for high-temperature walkins. (Efficiency Advocates, No. 37 at p.
2)
The alternate test approach in the
waivers requires that testing of ducted
units be conducted at 50 percent of the
maximum external static pressure
(‘‘ESP’’), subject to a tolerance of ¥0.00/
+0.05 in. wc.52 Consistent with the
waivers that DOE has granted for hightemperature refrigeration systems, in the
April 2022 NOPR DOE proposed that
testing for ducted systems be conducted
with ducts fitted and at 50 percent of
the unit’s maximum ESP, subject to a
tolerance of ¥0.00/+0.05 in. wc. Id.
DOE proposed to include this provision
for all ducted units (i.e., any ducted
low-temperature, medium-temperature,
or high-temperature refrigeration
system). Id. DOE also proposed
clarifying that if testing using either the
indoor or outdoor air enthalpy method,
which includes a measurement of the
air volume rate, the airflow
measurement apparatus fan would be
52 Inches of water column (‘‘in. wc’’) is a unit of
pressure conventionally used for measurement of
pressure differentials.
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adjusted to set the ESP—otherwise, the
ESP could be set by symmetrically
restricting the outlet of the test duct. Id.
If the ESP is not provided, DOE
proposed that it would be set such that
the air volume rate for the test is equal
to two-thirds of the value that is
measured for zero ESP operation. Id.
AHRI-Wine stated that wine cellar
manufacturers agree with the proposed
ESP requirements for ducted units;
however, they commented that the
proposed procedure for when ESP is not
provided represents an unrealistic
reduction in airflow. (AHRI-Wine, No.
30 at p. 4) AHRI-Wine provided no data
or alternative recommendation for a
procedure when ESP is not provided.
DOE has determined that the two-thirds
air volume rate is an appropriate value
to use when no maximum ESP is
provided. DOE notes that manufacturers
can provide maximum ESP to avoid
testing using the two-thirds air volume
rate.
AHRI-Wine also commented that
wine cellar manufacturers seek
clarification about whether the air
surrounding the ducted evaporator or
ducted condenser must be at the
required 90 °F indoor temperature.
(AHRI-Wine, No. 30 at p. 3)
Furthermore, wine cellar manufacturers
recommended that all wine cellar units,
regardless of specified condenser
location, be tested only at 90 °F to
clarify the test procedure and reduce
test burden. Id. DOE incorporates by
reference section 7.3.3.3 of ASHRAE
37–2009, which includes provisions for
testing ducted units and accounting for
duct losses; therefore, DOE has
determined that the ambient
temperature surrounding ducts should
not affect the test results. Consistent
with appendix C and the wine cellar test
procedure waivers, DOE is requiring in
appendix C1 that dedicated condensing
units located outdoors to be tested at
three temperatures—35 °F, 59 °F, and
95 °F—while dedicated condensing
units located indoors must be tested at
90 °F.
7. Variable-, Two-, and MultipleCapacity Systems
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a. Dedicated Condensing Units
In the April 2022 NOPR, DOE
proposed test procedures for variable-,
two-, and multiple-capacity condensing
units. The proposals addressed
numerous aspects of how such systems
would be tested, including (a) test
conditions (saturated suction
temperature and suction temperature)
for part-load operation, (b) compressor
operating levels for part-load testing, (c)
default unit cooler fan wattage to use in
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AWEF2 calculations as a function of
compressor operating level, and (d)
calculation of AWEF2 using multiple
levels of compressor operation. 87 FR
23920, 23962–23967.
(1) Need for Test Procedures for
Variable-, Two- and Multiple-Capacity
Condensing Units
In response to the DOE’s proposal,
some comments addressed the need for
test procedures for multi-/variablecapacity condensing units and the
potential utility and cost-effectiveness
of such systems. Specifically, AHRI and
KeepRite commented that the market for
such systems is very small, and that the
small market size is not driven by lack
of test method. AHRI and KeepRite
further stated that variable-capacity
system purchases are driven by
temperature operating tolerance
requirements rather than energy savings
and suggested that energy cost savings
would not offset upfront purchase and
installation costs. (AHRI, No. 30 at p. 8;
KeepRite, No. 36 at p. 3) National
Refrigeration commented that there is
no need for multi-/variable-capacity test
procedures at this time, indicating also
that there is limited to no evidence that
variable-capacity units are more
efficient. (National Refrigeration, No. 39
at p. 2) In response, DOE notes that the
DOE test procedures already include
test methods for variable-, two-, and
multi-capacity matched-pair
refrigeration systems through
incorporation by reference of AHRI
1250–2009. With the proposal and this
final rule, DOE is extending this test
method to dedicated condensing units
tested alone, which was included in the
ASRAC Term Sheet. (Docket EERE–
2015–BT–STD–0016, No. 56 at p. 3,
recommendation #6)
Despite questions about the need for
test procedures for variable-, two-, and
multi-capacity condensing units, AHRI
and KeepRite did indicate that the
proposal was reasonable. (AHRI, No. 30
at p. 8; KeepRite, No. 36 at p. 4) Other
commenters’ overall comments were
generally supportive regarding DOE’s
proposed test methods. (RSG, No. 41 at
p. 2; CA IOUs, No. 42 at p. 1; Efficiency
Advocates, No. 37 at p. 2)
(2) Unit Cooler Fan
DOE requested comment on its
assumptions regarding the unit cooler
with which a two-, multi-, or variablecapacity condensing unit rated alone
would be paired in the field, including
whether the unit cooler fan(s) would
have a full speed and a half-speed, the
compressor operating level at which the
unit cooler fan(s) would switch to half-
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28817
speed, and the half-speed wattage of the
fan(s). 87 FR 23920, 23966.
AHRI and KeepRite commented that a
calculation method should be allowed
for unit cooler fan power rather than
just high or low speed, indicating that
some variable compressor systems
would reduce capacity only to 75
percent of full capacity and would not
realize a gain from unit cooler fan
power. (AHRI, No. 30 at pp. 8–9;
KeepRite, No. 36 at p. 4) DOE
understands this comment to mean that
there would be limited efficiency gain
for a variable-speed compressor whose
lowest capacity is no lower than 75
percent of full capacity, and that it
would be important to consider
optimization of unit cooler fan speed.
National Refrigeration commented that
requiring a variable-speed or two-speed
unit cooler fan would be ideal, but the
effectiveness is unknown and more
research is necessary to determine how
to handle it. (National Refrigeration, No.
24 at p. 2) Lennox commented that unit
coolers with which two-, multi-, and
variable-capacity dedicated condensing
units are paired may use technology in
addition to two-speed fans, such as
electronic expansion valves (‘‘EEVs’’),
dampers, or other electronic control
valves. (Lennox, No. 35 at p. 6)
In response, DOE notes that if a
manufacturer decides to optimize unit
cooler fan operation or other design
details for a given condensing unit’s
compressor technology, the
manufacturer has the option of
certifying the two components together
as a matched pair—this is already an
established part of the test procedure for
outdoor matched pairs, and DOE is
extending the approach to indoor
matched pairs in this document (see
section III.G.7.b of this document).
DOE notes that the test method under
consideration applies to dedicated
condensing units tested alone—these
units would be paired with a unit cooler
in the field, so it is not clear what
technology the paired unit cooler might
have. For this reason, DOE developed
the proposal for two-, multi-, and
variable-capacity dedicated condensing
units based on the assumption of
limited unit cooler technology options.
DOE’s analysis suggests that use of partload compressor operation has limited
to no efficiency benefit when the unit
cooler fan(s) run at full speed. However,
DOE is aware that many unit coolers are
now sold with two-speed fan motors to
meet the current energy conservation
standards. (No. 44 at p. 2) Hence, DOE
determined that it is reasonable to
assume that field matches of dedicated
condensing units tested alone would
involve, at minimum, a unit cooler with
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a two-speed fan. DOE does not have
information that would suggest that unit
coolers sold alone would typically have
fully variable-speed fans, EEVs,
dampers, or other electronic control
valves. For this reason, DOE does not
believe it is appropriate to establish a
test procedure for dedicated condensing
units tested alone, assuming such
technology is available in a field-paired
unit cooler, therefore DOE has not
modified the test procedure to reflect
the potential benefits of these
technologies.
Some commenters indicated that,
although unit cooler fans may have two
speeds, the low speed may be triggered
by the off-cycle rather than by on-cycle
compressor operation. (AHRI, No. 30 at
p. 8; Lennox, No. 35 at p. 6; National
Refrigeration, No. 39 at p. 2) As
mentioned, DOE concluded that
running unit cooler fans at full speed
during part-load operation significantly
limits the part-load efficiency benefits.
Given the prevalence of unit coolers
being sold with two-speed fans, DOE
concludes it is reasonable to assume
that such unit coolers would be
controlled to allow two-speed fan
operation during part-load when fieldmatched with a two-, multi-, or variablespeed dedicated condensing unit.
DOE requested comment on its
assumptions regarding the compressor
operating level at which the unit cooler
fan(s) would switch from full- to halfspeed operation. 87 FR 23920, 23966.
AHRI commented that no change was
needed, and National Refrigeration was
supportive. (AHRI, No. 30 at p. 9;
National Refrigeration, No. 39 at p. 2)
No commenters suggested that
switching to half-speed operation
should occur at different compressor
operating levels. Hence, DOE is
finalizing the test procedure using the
same 65 percent compressor operating
level below which the unit cooler fan(s)
would be assumed to operate at halfspeed.
DOE requested comment on the
proposal that the unit cooler fan halfspeed power input would be 20 percent
of full speed power. 87 FR 23920,
23966. Several commenters agreed with
this approach. (AHRI, No. 30 at p. 9;
National Refrigeration, No. 39 at p. 2;
Lennox, No. 35 at p. 6) DOE is finalizing
its test procedure using the 20 percent
half-speed power level.
(3) Part-Load Test Conditions
DOE requested comment on the
compressor part-load operating levels
for multi- and variable-speed dedicated
condensing units tested alone. 87 FR
23920, 23966. Lennox, AHRI, and
National Refrigeration supported the
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proposed levels. (Lennox, No. 35 at p.
6; AHRI, No. 30 at p. 9, National
Refrigeration, No. 39 at p. 2) DOE is
finalizing the test procedure using the
compressor part-load operating levels
proposed in the April 2022 NOPR.
Regarding the test conditions
proposed for part-load operation of
variable-, two-, or multiple-capacity
dedicated condensing units, several
commenters suggested that the differing
refrigerant conditions specified for the
different tests were excessively complex
and should be simplified. (AHRI, No. 30
at p. 9; Lennox, No. 35 at p. 6; National
Refrigeration, No. 39 at p. 2) In response
to DOE’s specific question about
whether a tabular method for specifying
test operating conditions or a
correlation-based approach should be
used, Lennox expressed a clear
preference for a tabular approach,
indicating that the correlation approach
may provide more flexibility but would
require more data collection and should
be evaluated for accuracy. (Lennox, No.
35 at p. 6) Other commenters did not
express a clear position. For example,
AHRI commented that, while the
correlation approach may provide more
flexibility, it should be used only if it is
shown to be more accurate. (AHRI, No.
30 at p. 9)
DOE’s intent in allowing different
suction conditions for testing was to
make the test method more
representative of actual operation, in
which unit cooler effectiveness would
improve at part load, suction line
pressure drop would decrease, and
suction line heat transfer would be more
effective. These factors would combine
generally to raise the dedicated
condensing unit inlet pressure
(specified as saturated suction
temperature in the test procedures) and
also the suction temperature. 87 FR
23920, 23964.
Some commenters indicated that
these variations would make little
impact in test results. (Lennox, No. 35
at p. 6) DOE analyzed the proposed test
conditions to evaluate this statement for
outdoor refrigeration systems using R–
448A, calculating the impact on
compressor EER 53 and isolating the
impact of the change in suction
conditions as compared with the fullload test conditions,54 and not including
the potential benefits of improved
condenser effectiveness at part load nor
the potential change in the compressor’s
compression efficiency for different
53 Evaporator
capacity divided by compressor
input power.
54 23 °F saturated suction temperature and 41 °F
temperature for medium-temperature systems;
¥22 °F saturated suction temperature and 5 °F
temperature for low-temperature systems.
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operating conditions. The analysis
showed that, for medium-temperature
dedicated condensing units, the impact
of the modified suction conditions
ranged from ¥2.3 percent (a decrease)
to 7.7 percent, with an average of 2.8
percent. For low-temperature
condensing units, the range of impact
was from ¥3.0 percent to 2.4 percent,
with an average of ¥0.2 percent. This
analysis shows that an increase in
saturated suction temperature improves
compressor EER, while an increase in
suction temperature reduces compressor
EER. These factors appear to balance out
on average for low-temperature systems,
while for medium-temperature systems,
the improvement associated with the
saturated suction temperature increase
makes more impact than the suction
temperature increase. In addition, the
results do not change significantly when
considering other refrigerants
commonly used in WICF refrigeration
systems, e.g. R–404A and R–407A. For
indoor medium-temperature
refrigeration systems, the overall impact
of the changes is less pronounced, since
testing only with the A conditions using
90 °F condenser ambient air increases
the impact of the refrigerant temperature
rise in the suction line. For outdoor
medium-temperature systems, DOE
found that raising the saturated suction
temperature 1 °F for all part-load
conditions to 24 °F and leaving the
suction temperature unchanged at 41 °F
provided the best overall agreement in
compressor EER compared with the
average EER impact of the different
proposed test conditions. Consequently,
DOE is finalizing the specification of
suction conditions for testing variable-,
two-, and multiple-capacity dedicated
condensing units with the following
simplifications: For low-temperature
and indoor medium-temperature
dedicated condensing units, the
required part-load test conditions will
match the full-capacity conditions. For
outdoor medium-temperature dedicated
condensing units, the part-load
saturated suction temperature will be
raised 1 °F to 24 °F, without changing
the 41 °F suction temperature
requirement. DOE believes this
approach provides the best balance
between test procedure simplicity and
providing some adjustment of operating
conditions to represent the impacts of
changes in unit cooler and suction line
response to part load.
b. Indoor Matched Pair and SinglePackaged Units
DOE proposed in the April 2022
NOPR to establish test procedures for
indoor matched-pair and single-
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packaged dedicated systems. 87 FR
23920, 23966.
National Refrigeration stated that
indoor matched pairs have less potential
for part-load energy savings than their
outdoor counterparts due to their
constant condensing inlet temperature.
(National Refrigeration, No. 39 at p. 2)
KeepRite stated that the proposed
approach for indoor matched pairs is
acceptable, even though these units
have even less potential for part-load
energy savings due to the constant
condenser inlet temperature. (KeepRite,
No. 36 at p. 4) DOE understands that
these commenters were referring to
constant condenser air inlet
temperature, which would result in
constant condensing temperature.
Lennox supported the proposal to
establish test methods for indoor two-,
multi-, or variable-capacity condensing
units tested alone. (Lennox, No. 35 at
p.6) No commenters indicated that DOE
should not establish test methods for
such systems. Hence, DOE is adopting
the test method as proposed.
ddrumheller on DSK120RN23PROD with RULES2
c. Revision to EER Calculation for
Outdoor Variable-Capacity and
Multiple-Capacity Refrigeration Systems
In the April 2022 NOPR, DOE
proposed to revise the EER calculations
for outdoor variable-capacity and
multiple-capacity refrigeration systems
to use a piecewise linear calculation
approach rather than the parabolic
equation provided in AHRI 1250–2020.
87 FR 23920, 23966. DOE did not
receive any comments specifically
addressing this proposal and is
finalizing the test procedure with the
revisions as proposed.
d. Digital Compressors
In the April 2022 NOPR, DOE
discussed specific proposals associated
with digital compressors. To clarify the
test procedure for digital compressors,
DOE proposed to define ‘‘digital
compressor’’ as a compressor that uses
mechanical means for disengaging
active compression on a cyclic basis to
provide a reduced average refrigerant
flow rate in response to an input signal.
87 FR 23920, 23967. DOE received no
comments specifically addressing the
digital compressor definition and will
adopt the definition as proposed.
As discussed in the April 2022 NOPR,
DOE had conducted testing and found
that the refrigerant enthalpy method for
measuring capacity is accurate if the
liquid subcooling at the mass flow meter
is sufficiently low, as required in
section C3.4.5 of AHRI 1250–2020. Id.
DOE proposed that testing refrigeration
equipment with digital compressors
operating at part load may use the
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refrigerant enthalpy method as a
secondary test method, with the
following provisions and adjustments:
(1) pressure and temperature
measurement would be at a frequency of
once per second or faster, (2) the
operating tolerances for pressure and
temperature at both the inlet and outlet
connections and for mass flow would
not apply, and (3) enthalpies
determined for the capacity calculation
would be based on test-period-average
pressure and temperature values. Id.
DOE also proposed that the selection
of the primary test method for
measuring capacity would depend on
the refrigeration system configuration.
Id. For single-packaged dedicated
systems, the test methods adopted as
primary methods for any singlepackaged dedicated system would be
used, as discussed in section III.G.2 of
this document. Matched pairs would
use the same primary methods used for
single-packaged dedicated systems. For
dedicated condensing units, the primary
methods include outdoor air enthalpy
method, balanced ambient outdoor
calorimeter, and outdoor room
calorimeter measurements.
Lennox supported the proposals for
the part-load test procedure for
refrigeration systems with digital
compressors. (AHRI, No. 30 at p. 10;
Lennox, No. 35 at p. 7) KeepRite and
AHRI commented that the refrigerant
enthalpy method may be unreliable for
digital compressors because they cannot
achieve steady state. However, these
commenters did not provide evidence
that the method would be unreliable.
(KeepRite, No. 36 at p. 4; AHRI, No. 30
at p. 9) KeepRite and AHRI also
indicated that 1-second intervals for
power measurements would not be
sufficient for energy measurement of
digital compressors and that integrating
power meters must be used. Id.
However, AHRI also stated that the partload test procedure for refrigeration
systems with digital compressors is
sufficient as written. (AHRI, No. 30 at p.
9) AHRI provided further specific
comments, including (a) wider
refrigerant pressure and mass flow
tolerances look acceptable, (b) the 1second or higher data acquisition rate
looks acceptable, but that industry-wide
ability to sample at this rate should be
assessed, (c) that when using the
refrigerant enthalpy method with singlepackage systems with digital
compressors, the existing primary
methods look acceptable, and (d)–(e)
when using the refrigerant enthalpy
method to test matched pairs or
condensing units alone with digital
compressors, the existing dual
instrumentation method should be an
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28819
acceptable primary method for
measuring capacity. (AHRI, No. 30 at
pp. 9, 10)
DOE notes that the industry standard,
AHRI 1250–2020, already has a
requirement that energy measurements
be made using an integrating watt-hour
meter and that power measurements be
made with a sampling rate of no less
than 1 per second (see section C10.2.1.4
of AHRI 1250–2020)—thus, through
incorporation by reference of AHRI
1250–2020, the proposal is already
consistent with the KeepRite and AHRI
comments regarding use of an
integrating power meter for energy
measurements and already adopts 1second intervals for data acquisition. It
is DOE’s understanding that test
laboratories already use data acquisition
systems with this level of capability. As
indicated, the commenters did not
provide data countering the cited DOE
evidence that the refrigerant enthalpy
method measurement is accurate. Given
the limited data available on this issue,
DOE is not deviating from its proposal
that the refrigerant enthalpy method
only be used as a secondary capacity
measurement, i.e., the test procedure as
finalized in this document does not
allow it to be used as a primary capacity
measurement as recommended by AHRI
for matched pairs and dedicated
condensing units tested alone.
Therefore, DOE is adopting the
proposals for digital compressor systems
as stated in the April 2022 NOPR.
8. Defrost
The current test procedure references
section C11 of AHRI 1250–2009 to
measure defrost. In section C11 of AHRI
1250–2009, the moisture to provide a
frost load is introduced through the
infiltration of air at a 75.2 °F dry-bulb
temperature and a 64.4 °F wet-bulb
temperature into the walk-in freezer at
a constant airflow rate that depends on
the refrigeration capacity of the tested
freezer unit (Equations C11 and C12 in
section C11.1.1 of AHRI 1250–2009). A
key issue with this approach is the
difficulty in ensuring repeatable frost
development on the unit under test,
despite specifying the infiltration air
dry-bulb and wet-bulb temperatures. For
example, in addition to frost
accumulating on the evaporator of the
unit under test, frost may also
accumulate on the evaporator of other
cooling equipment used to condition the
room, which could subsequently affect
the rate of frost accumulation on the
unit under test by affecting the amount
of moisture remaining in the air.
Since there are recognized limitations
to the defrost test procedure in section
C11 of AHRI 1250–2009, AHRI 1250–
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2020 does not include a frosted-coil test
but does include provisions for a drycoil defrost test.55 Industry is currently
evaluating how to create and validate
consistent evaporator coil frost loads;
therefore, in the April 2022 NOPR, DOE
proposed to maintain the current
calculation-based approach for
estimating defrost energy consumption.
Specifically, DOE proposed to
incorporate by reference section C10 of
AHRI 1250–2020 for unit coolers with
either electric or hot gas defrost, except
for section C10.2.1.1, ‘‘Test Room
Conditioning Equipment.’’ At this time,
DOE does not have sufficient data to
fully evaluate how the test room
condition requirements in section
C10.2.1.1 of AHRI 1250–2020 would
impact the representativeness of the test
procedure during the dry-coil defrost
test relative to potential additional test
burden.
In response to the April 2022 NOPR,
HTPG commented that it agreed with
the proposal to incorporate the entirety
of Section C10 of AHRI 1250–2020,
except for section C10.2.1.1. (HTPG, No.
32 at p. 7) HTPG also agreed that all
systems would use the same default
calculated values to rate defrost power.
Id.
The CA IOUs stated that they support
DOE adopting a test method for
measuring defrost energy use in a future
test procedure and that if DOE adopts a
test method, DOE should reconsider the
frequency at which defrost is used. (CA
IOUs, No. 42 at p. 2) DOE will continue
to evaluate defrost energy use and may
address defrost energy in a future test
procedure rulemaking. In this final rule,
DOE is adopting the procedures as
proposed in the April 2022 NOPR in
appendix C1.
a. Adaptive Defrost
Adaptive defrost refers to a factoryinstalled defrost control system that
reduces defrost frequency by initiating
defrosts or adjusting the number of
defrosts per day in response to operating
conditions, rather than initiating defrost
strictly based on compressor run time or
clock time. 10 CFR 431.303. In the April
2022 NOPR, DOE proposed to maintain
its current requirements for adaptive
defrost. 87 FR 23920, 23969. DOE
received no comments on its proposal.
In this final rule, DOE is maintaining
the current regulatory approach to
55 AHRI 1250–2020 includes an adaptive defrost
challenge test in appendix E (Appendix E) and a hot
gas defrost challenge test in appendix F (Appendix
F) that require a frosted-coil. The tests in both of
these appendices are labeled as ‘‘informative,’’ and
were designed to evaluate adaptive defrost or hot
gas defrost functionality, respectively, rather than to
quantify defrost energy use.
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include the optional representation
strategy for adaptive defrost.
b. Hot Gas Defrost
In the April 2022 NOPR, DOE
proposed that manufacturers may
account for a unit’s potential improved
performance with hot gas defrost in its
market representations. 87 FR 23920,
23970. DOE proposed that this hot gas
defrost ‘‘credit’’ may be used in
marketing materials for all refrigeration
system varieties sold with hot gas
defrost (i.e., matched pairs, standalone
unit coolers, and standalone condensing
units). Id.
However, due to the variation of hot
gas defrost applications across the
refrigeration systems market, and a lack
of consensus on the definition of ‘‘hot
gas defrost’’ systems (see discussion in
section III.A.2.i of this document), DOE
is not adopting a hot gas defrost ‘‘credit’’
for representation purposes.
9. Refrigerant Glide
Refrigerant glide refers to the increase
in temperature at a fixed pressure as
liquid refrigerant vaporizes during its
conversion from saturated liquid (at its
bubble point) to saturated vapor (at its
dew point). R–404A—a common walkin refrigerant—has very little glide,
while R–407A—another common walkin refrigerant—can exhibit glide of up to
8 °F.
The current DOE test procedure
specifies unit cooler test conditions
based on the dew point at the
evaporator exit. For zero-glide
refrigerants, the average evaporator
temperature will typically be equivalent
to the specified dew point. However, for
high-glide refrigerants, the average
evaporator temperature will be
significantly lower than the dew point
since the refrigerant temperature will
increase (up to the dew point) as it
travels through the evaporator. As a
result, two identical unit coolers, one
charged with R–404A and one with R–
407A, will be tested at different
evaporator-to-air temperature
differences (‘‘TD’’), but with the same
evaporator airflow. Measured capacity is
directly correlated with the product of
TD and airflow; therefore, the high-glide
R–407A unit cooler would achieve a
higher rated capacity than the R–404A
unit cooler. However, this capacity
difference is an artifact of the test
procedure, which requires that unit
coolers and dedicated condensing units
be tested alone. In the field, a unit
cooler will be paired with a dedicated
condensing unit, and R–407A unit
coolers will not actually provide
additional capacity when compared to
their R–404A counterparts. For these
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reasons, the current test procedure is
not refrigerant-neutral.
In the April 2022 NOPR, DOE
discussed how the current test
procedure is not refrigerant-neutral in
terms of high-glide and zero-glide
refrigerants because it uses dewpoint
throughout the test procedure. 87 FR
23920, 23970. DOE also discussed the
modified midpoint approach, which is
more refrigerant-neutral. The modified
midpoint approach attempts to
standardize the average evaporator
temperature, rather than standardizing
the evaporator dew point. In doing so,
identical unit coolers using zero- and
high-glide refrigerants would exhibit
identical TDs, thus alleviating concerns
of overstated capacity.
While a modified midpoint approach
may be more refrigerant-neutral, DOE
notes that the AHRI 1250–2020, which
DOE is referencing in appendix C1, uses
a dewpoint rather than a modified
midpoint approach. DOE does not have
enough information at this time to
justify the use of a modified midpoint
approach. As a result, in the April 2022
NOPR, DOE proposed to continue to use
dew point throughout the test
procedure. Id.
In response to the April 2022 NOPR,
HTPG commented that it disagrees with
the midpoint approach and suggested
maintaining the dew point approach.
(HTPG, No. 32 at p. 7) DOE is adopting
the proposal from the April 2022 NOPR
and continuing to specify refrigerant
conditions using dew point.
10. Refrigerant Temperature and
Pressure Instrumentation Locations
As discussed in the April 2022 NOPR,
the specified superheat in AHRI 1250–
2020 differs from the current DOE test
procedure for dedicated condensing
unit efficiency calculations, but there is
no effective difference in where the
required pressure and temperature
measurements should be taken on the
equipment under test. 87 FR 23920,
23971. However, Figure C2 in AHRI
1250–2020 suggests that the use of a
suction line mass flow meter for these
measurements is not allowed. In the
April 2022 NOPR, DOE proposed to
clarify that a second mass flow meter in
the suction line would be allowed with
the adoption of AHRI 1250–2020. Id.
Specifically, DOE clarified that the
second mass flow measurement for the
DX dual instrumentation method may
be in the suction line upstream of the
inlet to the condensing unit, as shown
in Figure C1 of AHRI 1250–2009. AHRI,
HTPG, Lennox, Hussmann, and RSG
agreed with the proposal. (AHRI, No. 30
at p. 10; HTPG, No. 32 at p. 7; Lennox,
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No. 35 at p. 7; Hussmann, No. 38 at p.
10; RSG, No. 41 at p. 2)
AHRI also commented that DOE
should only reference AHRI 1250–2020,
not both AHRI 1250–2020 and AHRI
1250–2009, for the location of flow
meters. (AHRI, No. 30 at p. 10) DOE is
clarifying that only AHRI 1250–2020
will be referenced in appendix C1, and
that AHRI 1250–2009 is mentioned in
this discussion only to explain the
intention of the proposal. Therefore,
DOE is adopting the test procedure as
proposed in the April 2022 NOPR.
ddrumheller on DSK120RN23PROD with RULES2
11. Updates to Default Values for Unit
Cooler Parameters
As discussed in section III.B.3.c,
Sections 7.9.1 and 7.9.2 of AHRI 1250–
2020 add new equations to calculate oncycle evaporator fan power when testing
a dedicated condensing unit alone.
These equations are different from those
in the current test procedure in
appendix C, which calculates on-cycle
evaporator fan power based on the
cooling capacity of the condensing unit.
The equations in AHRI 1250–2020 are
based on more test data and analysis
than those currently in appendix C. In
the April 2022 NOPR, DOE proposed to
adopt the calculations for on-cycle
evaporator fan power for dedicated
condensing units tested alone as
prescribed in AHRI 1250–2020. 87 FR
23920, 23971–23972.
AHRI, HTPG, Lennox, and RSG
agreed with the proposed on-cycle
evaporator fan power calculations.
(AHRI, No. 30 at p. 10; HTPG, No. 32
at p. 7; Lennox, No. 35 at p. 7; RSG, No.
41 at p. 2) DOE is adopting the test
procedure as proposed in the April 2020
NOPR.
12. Calculations and Rounding
In the April 2022 NOPR, DOE
proposed new rounding requirements
for AWEF and capacity to ensure greater
test procedure consistency. 87 FR
23920, 23972. DOE clarifies here that
the rounding requirements proposed in
the April 2022 NOPR should have been
for AWEF2 and not AWEF, which
means that any rounding requirements
would become effective when appendix
C1 becomes effective.
DOE recognizes that the way values
are rounded can affect the resulting
capacity and AWEF2 values. To ensure
consistency in calculating capacity and
AWEF2 values, DOE proposed in the
April 2022 NOPR that raw measured
data be used in all capacity and AWEF2
calculations. Id. DOE’s current
standards specify a minimum AWEF2
value in Btu/(W-h) to the hundredths
place. DOE proposed rounding AWEF2
values to the nearest 0.05 Btu/(W-h). Id.
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To round capacity, DOE proposed to
round to the nearest multiple as
specified in Table III.7. The proposed
capacity bins and multiples are
consistent with other HVAC test
procedures.56
28821
validation of an AEDM by
demonstrating that the performance, as
predicted by the AEDM, agrees with the
performance as measured by actual
testing in accordance with the
applicable DOE test procedure. The
validation procedure and requirements,
TABLE III.7—REFRIGERATION CAPAC- including the statistical tolerance,
ITY RATING RANGES AND THEIR number of basic models, and number of
units tested vary by product or
ROUNDING MULTIPLES
equipment.
Once developed, an AEDM may be
Refrigeration capacity
Multiples,
used to rate and certify the performance
ratings, 1,000 Btu/h
Btu/h
of untested basic models in lieu of
<20 ........................................
100 physical testing. However, use of an
≥20 and <38 .........................
200 AEDM for any basic model is always at
≥38 and <65 .........................
500
the option of the manufacturer. One
≥65 ........................................
1,000
potential advantage of AEDM use is that
it may free a manufacturer from the
AHRI, HTPG, KeepRite, Lennox, and
burden of physical testing. One
National Refrigeration recommended
potential risk is that the AEDM may not
that AWEF2 values be rounded to the
perfectly predict performance, and the
nearest 0.01 Btu/(W-h), as current
manufacturer could be found
standards are taken to that precision.
responsible for having an invalid rating
(AHRI, No. 30 at pp. 10–11; HTPG, No.
for the equipment in question or for
32 at p. 8; KeepRite, No. 36 at p. 4;
having distributed a noncompliant basic
Lennox, No. 35 at p. 7; National
Refrigeration, No. 39 at p. 2) DOE agrees model. The manufacturer, by using an
AEDM, bears the responsibility and risk
that rounding to the nearest 0.05 Btu/
(W-h) as proposed may cause confusion. of the validity of the ratings. For walkTherefore, DOE is requiring that AWEF2 ins, DOE currently permits the use of
AEDMs for refrigeration systems only.
values be rounded to the nearest 0.01
10 CFR 429.70(f).
Btu/(W-h).
In a final rule published on May 13,
AHRI, AHRI-Wine, and RSG agreed
2014, DOE established that AEDMs can
with the proposed capacity ranges and
be used by walk-in refrigeration
respective rounding requirements.
manufacturers, once certain
(AHRI, No. 30 at p. 10; AHRI-Wine, No.
qualifications are met, to certify
30 at p. 4; RSG, No. 41 at p. 2) DOE is
compliance and report ratings. 79 FR
adopting the capacity rounding
27388, 27389. That rule established a
requirements as proposed in the April
uniform, systematic, and fair approach
2022 NOPR and summarized in Table
to the use of these types of modeling
III.7.
techniques that has enabled DOE to
H. Alternative Efficiency Determination ensure that products in the marketplace
are correctly rated—irrespective of
Methods for Refrigeration Systems
whether they are subject to actual
Pursuant to the requirements of 10
physical testing or are rated using
CFR 429.70, DOE may permit use of an
modeling—without unnecessarily
AEDM in lieu of testing equipment for
burdening regulated entities. Id. A
which testing burden may be
minimum of two distinct models must
considerable and for which that
be tested to validate an AEDM for each
equipment’s energy efficiency
validation class.
performance may be well predicted by
DOE is adopting new test procedures
such alternative methods. Although
for single-packaged dedicated systems,
specific requirements vary by product or high-temperature refrigeration systems,
equipment, use of an AEDM entails
and CO2 unit coolers. Application
development of a mathematical model
design temperature of the refrigerated
that estimates energy efficiency or
environment has a significant impact on
energy consumption characteristics of
equipment performance; therefore, in
the basic model, as would be measured
the April 2022 NOPR, DOE proposed to
by the applicable DOE test procedure.
incorporate new AEDM validation
The AEDM must be based on
classes for all high-temperature
engineering or statistical analysis,
refrigeration systems (single-packaged
computer simulation or modeling, or
dedicated systems and matched-pair
other analytic evaluation of performance systems). 87 FR 23920, 23973.
data. A manufacturer must perform
Additionally, single-packaged units are
expected to perform differently than
56 A version of Table III.14 can be found in AHRI
dedicated condensing units under the
Standard 390 I–P (2021), ‘‘Performance Rating of
test procedure which incorporates
Single-Package Vertical Air-conditioners and Heat
Pumps.’’
thermal losses. Therefore, in the April
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2022 NOPR, DOE proposed to create
new validation classes for lowtemperature, medium-temperature, and
high-temperature single-packaged
dedicated systems. Id. To ensure that
walk-in validation classes are consistent
with DOE’s current walk-in
terminology, DOE proposed to rename
the ‘‘unit cooler connected to a
multiplex condensing unit’’ validation
classes to ‘‘unit cooler’’ at either
medium- or low-temperature; however,
the AEDM requirements for these
classes remain the same. Id. Finally,
DOE proposed to remove the medium/low-temperature indoor/outdoor
condensing unit validation classes, as
these are redundant with the medium/low-temperature indoor/outdoor
dedicated condensing unit validation
classes. Id.
Implementation of appendix C1 will
require that all AEDMs for singlepackaged dedicated systems are
amended to be consistent with the test
procedure proposed in appendix C1.
The AEDM validation classes for
walk-in refrigeration equipment DOE
proposed in the April 2022 NOPR are as
follows:
• Dedicated Condensing Unit, MediumTemperature, Indoor System
• Dedicated Condensing Unit, MediumTemperature, Outdoor System
• Dedicated Condensing Unit, LowTemperature, Indoor System
• Dedicated Condensing Unit, LowTemperature, Outdoor System
• Single-packaged Dedicated System,
High-Temperature, Indoor System
• Single-packaged Dedicated System,
High-Temperature, Outdoor System
• Single-packaged Dedicated System,
Medium-Temperature, Indoor System
• Single-packaged Dedicated System,
Medium-Temperature, Outdoor
System
• Single-packaged Dedicated System,
Low-Temperature, Indoor System
• Single-packaged Dedicated System,
Low-Temperature, Outdoor System
• Matched Pair, High-Temperature,
Indoor Condensing Unit
• Matched Pair, High-Temperature,
Outdoor Condensing Unit
• Matched Pair, Medium-Temperature,
Indoor Condensing Unit
• Matched Pair, Medium-Temperature,
Outdoor Condensing Unit
• Matched Pair, Low-Temperature,
Indoor Condensing Unit
• Matched Pair, Low-Temperature,
Outdoor Condensing Unit
• Unit Cooler, High-Temperature
• Unit Cooler, Medium-Temperature
• Unit Cooler, Low-Temperature
Additionally, DOE proposed in the
April 2022 NOPR to maintain the
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provision that outdoor models within a
given validation class may be used to
determine represented values for the
corresponding indoor class, and
additional validation testing is not
required. 87 FR 23920, 23973. For
example, two medium-temperature
outdoor dedicated condensing units
may be used to validate an AEDM for
both the ‘‘Dedicated Condensing Unit,
Medium-Temperature, Outdoor System’’
class and the ‘‘Dedicated Condensing
Units, Medium-Temperature, Indoor
System’’ class. If indoor models that fall
within a given validation class are
tested and used to validate an indoor
AEDM, however, that test data may not
be used to validate the equivalent
outdoor validation class.
In the April 2022 NOPR, DOE
proposed no additional modifications to
the walk-in specific AEDM provisions
within 10 CFR 429.70(f). Id. In the April
2022 NOPR, DOE requested comment
on its proposal to modify and extend its
AEDM validation classes. Id.
AHRI, Lennox, National Refrigeration,
and RSG agreed with the proposed
AEDM validation classes. (AHRI, No. 30
at p. 11; Lennox, No. 35 at p. 8; National
Refrigeration, No. 39 at p. 2; RSG, No.
41 at p. 3) HTPG agreed with DOE’s
proposals to (1) add single-packaged
dedicated system validation classes, (2)
to rename ‘‘unit cooler connected to a
multiplex condensing unit’’ validation
classes to ‘‘unit cooler,’’ and (3) to
remove medium-/low-temperature
indoor/outdoor condensing unit
validation classes to eliminate
redundancy. (HTPG, No. 32 at p. 8)
AHRI-Wine agreed with the proposed
validation classes. (AHRI-Wine, No. 30
at p. 4)
AHRI-Wine requested clarification on
whether there are AEDM validation
classes for high-temperature dedicated
condensing units. Id. DOE is clarifying
that there are no AEDM validation
classes for high-temperature dedicated
condensing units. As discussed in
section III.F.7, DOE has found that the
wine cellar industry seems to use
general-purpose dedicated condensing
units, which must meet the mediumtemperature dedicated condensing unit
energy conservation standard and
should be certified as such. These
general-purpose dedicated condensing
units would fall into the ‘‘Dedicated
Condensing Unit, Medium-Temperature
Outdoor System’’ or ‘‘Dedicated
Condensing Unit, Medium-Temperature
Indoor System’’ AEDM validation class.
DOE is adopting the AEDM validation
classes for refrigeration systems as
proposed in the April 2022 NOPR.
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I. Sampling Plan for Enforcement
Testing
As discussed in the April 2022 NOPR,
DOE uses appendix B to subpart C of 10
CFR part 429 to assess compliance for
walk-in refrigeration systems, which is
specifically intended for use for covered
equipment and certain low-volume
covered products. 87 FR 23920, 23973.
DOE does not specifically reference
which appendix in subpart C of 10 CFR
part 429 it uses for determination of
compliance for walk-in doors or walk-in
panels. In an Enforcement NOPR
published on August 31, 2020 (‘‘August
2020 Enforcement NOPR’’), DOE
proposed to add walk-in cooler and
freezer doors and walk-in panels to the
list of equipment subject to the lowvolume enforcement sampling
procedures in appendix B to subpart C
of 10 CFR part 429. 85 FR 53691, 53696.
DOE noted that this equipment is not
currently included within DOE’s list
because when the current regulations
were drafted, walk-in doors and walk-in
panels did not have applicable
performance standards, only design
standards, and therefore sampling
provisions were not necessary at the
time. In the April 2022 NOPR, DOE
proposed to include walk-in doors and
walk-in panels in the list of covered
equipment and certain low-volume
products at 10 CFR 429.110(e)(2). 87 FR
23920, 23973.
AHRI, Hussmann, Bally, and RSG all
requested clarification on the definition
of ‘‘low-volume.’’ (AHRI, No. 30 at p.
11; Hussmann, No. 34 at p. 4; Bally, No.
40 at p. 5; RSG, No. 41 at p. 3)
DOE does not define a numerical
threshold for ‘‘low-volume’’ or ‘‘highvolume’’ products and equipment, and
for some products and equipment the
Department may consider volume on a
case-by-case basis. DOE created the
‘‘low-volume’’ designation to separate
built-to-order equipment from premanufactured, off the shelf products,
providing built-to-order equipment a
longer time period to ship a basic
model. 76 FR 12421, 12435. In the
context of enforcement, 10 CFR
429.110(e)(1) states that DOE will use a
sample size of not more than 21 units
and follow the sampling plans in
appendix A to subpart C of 10 CFR part
429 to determine compliance with the
applicable DOE standards for highvolume equipment, while DOE will use
a sample size of not more than 4 units
and follow the sampling plans in
appendix B to subpart C of 10 CFR part
429 to determine compliance with the
applicable DOE standards for lowvolume equipment. As specified in 10
CFR 429.110(b), units selected for
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enforcement evaluation are provided by
the manufacturer. DOE notes that walkin refrigeration systems are currently
included in the list of covered
equipment and certain low-volume
products at 10 CFR 429.110(e)(2).
Including walk-in door and panels
ensures all walk-in components are
similarly evaluated. DOE is including
walk-in doors and panels in the list of
covered equipment and certain lowvolume covered products at 10 CFR
429.110(e)(2) and thus will use the
sampling plan in appendix B to subpart
C of 10 CFR part 429.
DOE is adopting the enforcement
sampling plan as proposed in the April
2022 NOPR.
Bally also asked for clarification
regarding how the low-volume sampling
procedures work when coupled with
new section 5.4.3 of appendix B to
subpart R of 10 CFR part 431. (Bally, No.
40 at p. 5) Bally asked whether
appendix B to subpart C of 10 CFR part
429 is a restatement of 10 CFR
429.53(a)(3)(ii)(B)(2). Id. DOE notes that
the sampling plan provisions in
appendix B to subpart C of 10 CFR part
429 are strictly for the Department’s
evaluation of compliance when
conducting enforcement testing. The
provisions at 10 CFR
429.53(a)(3)(ii)(B)(2) are the
requirements that manufacturers are
required to follow when determining
the represented value certified to DOE.
DOE did not propose to make changes
to the certification language in the April
2022 NOPR. The provisions in the new
section 5.4.3 of appendix B to subpart
R of 10 CFR part 431 are intended to
allow manufacturers to use K-factor test
results from a set of test samples to
determine R-value of envelope
components with varying foam
thicknesses as long as the foam
throughout the panel is of the same final
chemical form and the test was
completed at the same test conditions as
other envelope components. In other
words, if a manufacturer offers 4-inch
and 5-inch cooler panels, the
manufacturer may use the K-factor
results of a single series of tests to
determine the R-value for both the 4inch and 5-inch cooler panels.
J. Organizational Changes
In the April 2020 NOPR, DOE
proposed a number of non-substantive
organizational changes. 87 FR 23920,
23977. As discussed previously, DOE
proposed to reorganize appendices A
and B so that they are easier for
stakeholders to follow as a step-by-step
test procedure. Additionally, DOE
proposed to remove the specifications at
10 CFR 429.53(a)(2)(i) regarding specific
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test procedure provisions and instead
include these provisions in the uniform
test method section at 10 CFR 431.304.
The intent of this proposed change was
to move provisions of the applicable test
procedure to the appropriate place in
subpart R, rather than keeping them
under the provisions for determining
represented values for certification.
However, DOE proposed to keep the
additional detail regarding the
represented values of various
configurations of refrigeration systems
(e.g., outdoor and indoor dedicated
condensing units, matched refrigeration
systems, etc.) at 10 CFR 429.53(a)(2)(i).
DOE received no comment on these
proposals regarding organizational
changes and therefore is adopting them
as proposed in the April 2022 NOPR.
K. Test Procedure Costs and Impact
EPCA requires that test procedures
proposed by DOE be reasonably
designed to produce test results which
reflect energy efficiency and energy use
of a type of industrial equipment during
a representative average use cycle and
not be unduly burdensome to conduct.
(42 U.S.C. 6314(a)(2)) The following
sections discuss DOE’s evaluation of the
estimated costs and savings associated
with the amendments in this final rule.
1. Doors
In this document, DOE is adopting the
following amendments to the test
procedures in appendix A for walk-in
cooler and freezer doors:
• Referencing NFRC 102–2020 for the
determination of U-factor;
• Including AEDM provisions for
manufacturers to alternately determine
the total energy consumption of display
and non-display doors;
• Providing additional detail for
determining the area used to convert Ufactor into conduction load, As, to
differentiate it from the area used to
determine compliance with the
standards, Add or And;
• Specifying a PTO value of 97
percent for door motors.
The first and third amendments,
referencing NFRC 102–2020 and
additional detail on the area used to
convert U-factor into a conduction load,
improve the consistency,
reproducibility, and representativeness
of test procedure results. The second
amendment, including AEDM
provisions, intends to provide
manufacturers with the flexibility to use
an alternative method to testing that
provides good agreement for their doors.
The fourth amendment, including a
PTO value of 97 percent, intends to
provide a more representative and
consistent means for comparison of
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walk-in door performance for doors
with motors.
DOE has determined that these
proposed amendments would improve
the representativeness, accuracy, and
reproducibility of the test results, and
would not be unduly burdensome for
door manufacturers to conduct. DOE has
also determined that these proposed
amendments would not increase testing
costs per basic model relative to the
current DOE test procedure in appendix
A, which DOE estimates to be $10,000
for third-party labs to determine energy
consumption of a walk-in door,
including physical U-factor testing per
NFRC 102–2020.57 Finally, DOE has
determined that manufacturers would
not be required to redesign any of the
covered equipment or change how the
equipment is manufactured solely as a
result of these amendments.
The cost impact to manufacturers as
a result of the reference to NFRC 102–
2020 and inclusion of AEDM provisions
is dependent on the agreement between
tested and simulated values as specified
in section 4.7.1 of NFRC 100–2010 58
and as referenced in the current test
procedure. For manufacturers of doors
that have been able to achieve the
specified agreement between U-factors
simulated using the method in NFRC
100–2010 and U-factors tested using
NFRC 102–2020, after physically
conducting testing to validate the
AEDM, manufacturers would be able to
continue using the simulation method
in NFRC 100–2010 provided it meets
the basic requirements proposed for an
AEDM in 10 CFR 429.53 and 429.70(f).
For manufacturers of doors that have
not been able to achieve the specified
agreement between U-factors simulated
using the method in NFRC 100–2010
and U-factors tested using NFRC 102–
2020, DOE estimates that the test burden
would decrease. Under the current
requirements, manufacturers may be
required to determine U-factor through
physical testing of every basic model.
With the new test procedure,
57 DOE estimates the cost of one test to determine
energy consumption of a walk-in door, including
one physical U-factor test per NFRC 102–2020, to
be $5,000. Per the sampling requirements specified
at 10 CFR 429.53(a)(3)(ii) and 429.11(b),
manufacturers are required to test at least two units
to determine the rating for a basic model, except
where only one unit of the basic model is produced.
58 Section 4.7.1 of NFRC 100–2010 requires that
the accepted difference between the tested U-factor
and the simulated U-factor be (a) 0.03 Btu/(h-ft2-°F)
for simulated U-factors that are 0.3 Btu/(h-ft2-°F) or
less, or (b) 10 percent of the simulated U-factor for
simulated U-factors greater than 0.3 Btu/(h-ft2-°F).
This agreement must match for the baseline product
in a product line. Per NFRC 100–2010, the baseline
product is the individual product selected for
validation; it is not synonymous with ‘‘basic
model’’ as defined in 10 CFR 431.302.
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manufacturers who would have
otherwise been required to physically
test every walk-in door basic model
could develop an AEDM for rating their
basic models of walk-in doors consistent
with the proposed provisions in 10 CFR
429.53 and 429.70(f). DOE estimates the
per-manufacturer cost to develop and
validate an AEDM for a single validation
class of walk-in doors to be $11,100.
DOE estimates an additional cost to
determine energy consumption of a
walk-in door using an AEDM to be $46
per basic model.59
DOE expects that the additional detail
provided for determining the area used
to convert U-factor into conduction
load, As, would either result in reduced
energy consumption or have no impact.
To the extent that this change to the test
procedure would amend the energy
consumption attributable to a door, such
changes would either not change the
calculated energy consumption or result
in a lower energy consumption value as
compared to how manufacturers may
currently be rating, given that the
current test procedure does not provide
specific details on measurement of Add
and And. As such, DOE expects that
manufacturers would be able to rely on
data generated under the current test
procedure. While manufacturers must
submit a report annually to certify a
basic model’s represented values, basic
models do not need to be retested
annually. The initial test results used to
generate a certified rating for a basic
model remain valid if the basic model
has not been modified from the tested
design in a way that makes it less
efficient or more consumptive, which
would require a change to the certified
rating. If a manufacturer has modified a
basic model in a way that makes it more
efficient or less consumptive, new
testing is only required if the
manufacturer wishes to make claims
using the new, more efficient rating.60
For doors without motors, DOE has
concluded that the proposed test
procedure would not change energy
consumption ratings, which would not
require rerating solely as result of DOE’s
adoption of this amendment to the test
59 DOE estimated initial costs to validate an
AEDM assuming 24 hours of general time to
develop and validate an AEDM based on existing
simulation tools. DOE estimated the cost of an
engineering calibration technician fully burdened
wage of $46 per hour plus the cost of third-party
physical testing of two basic models per proposed
validation class. DOE estimated the additional per
basic model cost to determine efficiency using an
AEDM assuming 1 hour per basic model at the cost
of an engineering calibration technician wage of $46
per hour.
60 See guidance issued by DOE at
www1.eere.energy.gov/buildings/appliance_
standards/pdfs/cert_faq_2012-04-17.pdf.
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procedure. Therefore, DOE has
determined all proposed amendments
either decrease or result in no additional
testing costs to manufacturers of walkin doors.
To the extent that changes to the test
procedure would amend the energy
consumption attributable to a door
motor, such changes would either not
change the calculated energy
consumption or result in a lower energy
consumption value as compared to the
currently granted waivers addressing
door motors. As such, DOE expects that
manufacturers would be able to rely on
data generated under the current test
procedure and current waivers. While
manufacturers must submit a report
annually to certify a basic model’s
represented values, basic models do not
need to be retested annually. The initial
test results used to generate a certified
rating for a basic model remain valid if
the basic model has not been modified
from the tested design in a way that
makes it less efficient or more
consumptive, which would require a
change to the certified rating. If a
manufacturer has modified a basic
model in a way that makes it more
efficient or less consumptive, new
testing is only required if the
manufacturer wishes to make claims
using the new, more efficient rating.
In the April 2022 NOPR, DOE
requested comment on its
understanding of the impact of the test
procedure proposals for appendix A. 87
FR 23920, 23979.
AHRI stated that it is unable to
determine or comment on impact until
it understands the AEDM for doors.
(AHRI, No. 30 at p. 11) DOE has
provided additional detail regarding
AEDMs in section III.C.1 of this
document and estimates that the test
burden would decrease for the industry
as a whole.
Bally commented that the $11,000
estimated cost for U-factor testing
doesn’t consider the cost of materials.
(Bally, No. 40 at p. 5) DOE has
determined that the DOE test procedure
for walk-in doors is non-destructive and
that units can therefore be recovered
after testing. For this reason, DOE does
not include the cost of the unit under
test.
While stakeholders did not
specifically recommend including
freight costs in the test cost estimates for
walk-in doors, they did recommend
including freight costs in the test cost
estimates for walk-in refrigeration
systems (discussed in section III.K.3 of
this document). DOE acknowledges that
freight costs are an additional expense
associated with third-party testing.
Therefore, to be consistent with the
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estimates provided for refrigeration
system testing, DOE has estimated the
cost of round-trip freight. DOE estimates
that the shipping cost for a walk-in box
from a manufacturing facility to a test
lab can range from $800 to $2,500
depending on the relative locations of
the two facilities, the weight and size of
the unit being shipped, and the
discounts associated with shipping
multiple units at one time. Thus, DOE
estimates the round-trip freight costs as
ranging from $1,600 to $5,000.
2. Panels
In this final rule, DOE is amending
the existing test procedure in appendix
B for measuring the R-value of
insulation of panels by:
• Incorporating by reference the
updated version of the applicable
industry test method, ASTM C518–17;
• Including provisions specific to
measurement of test specimen and total
insulation thickness; and
• Providing a method for determining
the parallelism and flatness of the test
specimen.
The first amendment incorporates by
reference the most up-to-date version of
the industry standards currently
referenced in the DOE test procedure.
The second and third amendments
include additional instructions intended
to improve consistency and
reproducibility of test procedure results.
DOE has determined that these
proposed amendments would improve
the accuracy and reproducibility of the
test results and would not be unduly
burdensome for manufacturers to
conduct, nor would they be expected to
increase the testing burden.
DOE expects that the proposed test
procedure in appendix B for measuring
the R-value of insulation would not
increase testing costs per basic model
relative to the current DOE test
procedure, which DOE estimates to be
$1,200 for third-party laboratory
testing.61 Additionally, DOE has
determined that the test procedure in
appendix B would not result in
manufacturers having to redesign any of
the covered equipment or change how
the equipment is manufactured.
In the April 2022 NOPR, DOE
requested comment on its
understanding of the impact of the test
procedure proposals for appendix B. 87
FR 23920, 23975.
AHRI agreed with DOE’s
understanding of the impact of the test
61 DOE estimates the cost of one test to determine
R-value to be $600. Per the sampling requirements
specified at 10 CFR 429.53(a)(3)(ii) and 429.11(b),
manufacturers are required to test at least two units
to determine the rating for a basic model, except
where only one unit of the basic model is produced.
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procedure. (AHRI, No. 30 at p. 12) Bally
commented that the increased
measurement and complex calculations
involving least squares regression for
parallelism and flatness are overly
burdensome and that it anticipates
difficulty finding laboratories capable of
doing the calculations. (Bally, No. 40 at
p. 6) In response to Bally’s comment,
DOE reiterates that the measurement
and calculations for parallelism and
flatness are necessary to improve the
accuracy and reproducibility of the test
results. Additionally, what Bally has
identified as increased measurement are
generally measurements that are already
being taken by third party laboratories,
but which have not been specified in
the DOE test procedure. With respect to
the complexity of the calculations, DOE
notes that third party laboratories
typically use templates to run
calculations which would be repeated
for multiple tests conducted and that,
while a laboratory may need to initially
update the template they use, the
calculations would not be overly
complex and burdensome on an ongoing
basis for testing. DOE was also able to
find laboratories capable of doing the
additional measurements and
calculations. Thus, DOE has determined
that the procedure is not overly
burdensome.
Because the test procedure for walkin panels is destructive and that units
cannot be recovered after testing, DOE is
including in its evaluation the cost of
the unit under test. DOE estimates the
cost of a walk-in panel to range from
$90 to $300, depending on size and
materials used, and when testing a
minimum of two units of a basic model
as required by 10 CFR 429.53(a)(1), a
total cost of $180 to $600 per basic
model.
DOE acknowledges that freight costs
are an additional expense associated
with third-party testing. Therefore, DOE
has estimated the cost of freight to the
test facility. DOE estimates that the
shipping cost for one walk-in box from
a manufacturing facility to a test
laboratory can range from $800 to
$2,500 depending on the relative
locations of the two facilities, the weight
and size of the unit being shipped, and
the discounts associated with shipping
multiple units at one time.
3. Refrigeration Systems
DOE is adopting certain changes to
appendix C that DOE has determined
will improve the accuracy and
reproducibility of the test results and
would not be unduly burdensome for
manufacturers to conduct. DOE has
further determined that these changes
will not impact testing cost.
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Additionally, the amended, appendix C
measures AWEF per AHRI 1250–2009,
and therefore does not contain any
changes that will require retesting or
rerating. The current testing costs which
DOE have determined will be equivalent
to the amended appendix C testing costs
are summarized in this section. DOE’s
assessment of the impacts of the
amendments of appendix C to include
new test procedures for hightemperature refrigeration systems and
CO2 unit coolers are discussed in more
detail in this section.
In response to the April 2022 NOPR,
HTPG agreed that proposals to appendix
C will not be unduly burdensome or
impact cost. (HTPG, No. 32 at p. 8)
DOE is also adopting certain changes
in the new appendix C1 that will amend
the existing test procedure for walk-in
coolers and freezers by:
• Expanding the off-cycle
refrigeration system power
measurements;
• Adding methods of test for singlepackaged dedicated systems; and
• Including a method for testing
ducted systems.
DOE has determined that these
amendments will improve the
representativeness, accuracy, and
reproducibility of the test results, and
will not be unduly burdensome for
manufacturers to conduct. DOE has also
determined that these amendments will
impact testing costs by equipment type.
DOE does not anticipate that the
remainder of the amendments adopted
in this final rule would impact test costs
or test burden. DOE estimates thirdparty costs for testing to the current
DOE test procedure to be:
• $10,000 for outdoor lowtemperature and medium-temperature
dedicated condensing units tested
alone;
• $6,500 for indoor low-temperature
and medium-temperature dedicated
condensing units tested alone;
• $6,500 for low-temperature unit
coolers tested alone;
• $6,000 for medium-temperature
unit coolers tested alone;
• $10,000 for single-packaged
dedicated systems; and
• $10,000 for high-temperature
matched pairs.
As discussed previously in section
III.G.1 of this document, DOE is
adopting off-cycle test provisions in
AHRI 1250–2020 for walk-in cooler and
freezer refrigeration systems. The
current test procedure requires off-cycle
power to be measured at a single
ambient condition (i.e., 90 °F). The new
test procedure requires off-cycle to be
measured at three different ambient
conditions (i.e., 95 °F, 59 °F, and 35 °F)
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for outdoor dedicated condensing units,
outdoor matched pair systems, and
outdoor dedicated systems. The
matched-pair and single-packaged
dedicated systems include hightemperature refrigeration systems. When
the waivers for these high-temperature
refrigeration systems were granted, only
one off-cycle test was required;
therefore, manufacturers with waivers
would be required to conduct additional
testing compared to the alternate test
procedure currently required. DOE
estimates that measuring off-cycle
power at these additional ambient
conditions may increase third-party lab
test cost by $1,000 per unit to a total
cost of $11,000 per unit for outdoor
dedicated condensing units, outdoor
matched-pair systems, and outdoor
single-packaged dedicated systems.
Manufacturers are not required to
perform laboratory testing on all basic
models. In accordance with 10 CFR
429.53, WICF refrigeration system
manufacturers may elect to use AEDMs.
DOE estimates the per-manufacturer
cost to develop and validate an AEDM
for outdoor dedicated condensing units
and outdoor matched-pair systems to be
$24,600.62 DOE estimates an additional
cost of approximately $46 per basic
model 63 for determining energy
efficiency of a given basic model using
the validated AEDM.
As discussed previously in section
III.G.2, DOE is adopting the singlepackaged dedicated system test
procedure for walk-ins in AHRI 1250–
2020. The procedure requires air
enthalpy tests to be used as the primary
test method. In the current test
procedure, single-packaged dedicated
systems use refrigerant enthalpy as the
primary test method. DOE does not
estimate a difference in physical testing
costs between air and refrigerant
enthalpy testing of single-packaged
units. DOE estimates the per-unit thirdparty lab test cost to be $11,000 for
outdoor single-packaged dedicated
62 Outdoor single-packaged systems are also
impacted by the proposed adoption of the AHRI
1250–2020 single-packaged test procedure for walkin cooler and freezer refrigeration systems. The
combined potential cost increase for outdoor singlepackaged systems is presented in the next
paragraph.
63 DOE estimated initial costs to validate an
AEDM assuming 40 hours of general time to
develop an AEDM based on existing simulation
tools and 16 hours to validate two basic models
within that AEDM at the cost of an engineering
calibration technician fully burdened wage of $46
per hour plus the cost of third-party physical testing
of two units per validation class (as required in 10
CFR 429.70(c)(2)(iv)). DOE estimated the additional
per basic model cost to determine efficiency using
an AEDM assuming 1 hour per basic model at the
cost of an engineering calibration technician wage
of $46 per hour.
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systems and $6,500 for indoor singlepackaged dedicated systems. However,
should a manufacturer choose to use an
AEDM, it may incur additional costs
regarding the development and
validation of new AEDMs for singlepackaged dedicated systems. DOE
estimates the per-manufacturer cost to
develop and validate an AEDM to be
$24,600 for outdoor single-packaged
units and $15,600 for indoor singlepackaged units. DOE estimates an
additional cost of approximately $46 per
basic model 64 for determining energy
efficiency using the validated AEDM.
As discussed in sections III.F.6 and
III.G.6, DOE is adopting test procedures
for CO2 unit coolers and hightemperature refrigeration systems. DOE
estimates that the average third-party
lab per unit test cost would be $11,000
for a high-temperature matched-pair or
single-packaged dedicated system,
$6,000 for a high-temperature unit
cooler tested alone, $6,500 for a lowtemperature CO2 unit cooler, and $6,000
for a medium-temperature CO2 unit
cooler. As discussed previously, DOE
has granted waivers to certain
manufacturers for both hightemperature refrigeration systems and
CO2 unit coolers. The test procedures
being adopted are consistent with the
alternate test procedures included in the
granted waivers. For those
manufacturers who have been granted a
test procedure waiver for this
equipment, DOE expects that there
would be no additional test burden.
However, DOE expects that there would
be additional testing costs for any
manufacturers of these products who
have not submitted or been granted a
test procedure waiver at the time this
test procedure is finalized. Such
companies may incur an additional per
unit test cost of:
• $11,000 for a high-temperature
matched-pair or single-packaged system;
• $6,000 for a high-temperature unit
cooler tested alone;
• $6,500 for a low-temperature CO2
unit cooler tested alone; and
• $6,000 for a medium-temperature
CO2 unit cooler tested alone.
In the April 2022 NOPR, DOE
requested comment on its
64 DOE estimated initial costs to validate an
AEDM assuming 40 hours of general time to
develop an AEDM based on existing simulation
tools and 16 hours to validate two basic models
within that AEDM at the cost of an engineering
calibration technician fully burdened wage of $46
per hour plus the cost of third-party physical testing
of two units per validation class (as required in 10
CFR 429.70(c)(2)(iv)). DOE estimated the additional
per basic model cost to determine efficiency using
an AEDM assuming 1 hour per basic model at the
cost of an engineering calibration technician wage
of $46 per hour.
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understanding of the impact of the test
procedure proposals for refrigeration
systems. 87 FR 23920, 23976.
AHRI commented that a third-party
lab test of a low-temperature unit cooler
would be two to three times more
expensive than DOE’s $6,500 estimate.
(AHRI, No. 30 at p. 12) Lennox stated
that, in general, DOE’s amendments
increase work content of the test and
therefore increase test costs. (Lennox,
No. 35 at p. 8) Lennox also stated that
the costs of their third-party lab tests
have been at least double DOE’s
estimates. Id. RSG commented that it
considers DOE’s estimates to be very
low and stated that there are few outside
labs capable of testing to the degree that
DOE requires. (RSG, No. 41 at p. 3)
AHRI-Wine stated that they believe the
estimated testing burden is reasonable
and consistent. (AHRI-Wine, No. 30 at
p. 4) DOE notes that the estimated test
costs were based on actual lab quotes,
which DOE has determined are
representative of the pricing available to
the industry as a whole. Additionally,
DOE is aware of third-party labs that
have the capability to test to the current
DOE test procedure.
HTPG disagreed with DOE’s test cost
estimates for AEDMs and stated that 40
hours of labor per refrigerant is more
accurate and therefore test costs would
be multiplied by the number of
refrigerants. (HTPG, No. 32 at p. 8)
HTPG also stated that more validation
would be done by manufacturers than
what was estimated to ensure an AEDM
applies across a basic model family. Id.
DOE notes that the estimated AEDM
cost is per AEDM and does not make
assumptions about the number of
AEDMs needed based on the refrigerants
used by a given manufacturer. DOE used
the minimum number of tests (two)
needed to validate an AEDM. While
manufacturers may choose to test more
units to validate an AEDM, testing more
than two is not required.
AHRI stated that small original
equipment manufacturers (‘‘OEMs’’)
represent a significant amount of the
market and will be negatively impacted
by added complexity and costs. (AHRI,
No. 30 at p. 12) NAFEM encouraged
DOE to consider the limitation of lab
capacity and the financial impacts on
small businesses. (NAFEM, No. 33 at p.
2) DOE specifically discusses the test
procedure burden imposed on small
businesses in section IV.B of this
document.
AHRI stated that EPA and DOE
regulations will impact small
refrigeration OEMs in a relatively
immediate time frame. (AHRI, No. 30 at
p. 12) NAFEM also commented that
DOE should evaluate how various EPA
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rulemakings may impact energy
efficiency improvements in the WICF
manufacturing process and available
products. (NAFEM, No. 33 at p. 2) DOE
acknowledges that while there are other
regulations that impact walk-in
equipment, DOE will take cumulative
regulatory burden into account in the
ongoing energy conservation standards
rulemaking as part of its manufacturer
impact analysis.
AHRI and Lennox commented that
the test cost estimates should include
freight cost, unit cost, and cost of a unit
to run the test. (AHRI, No. 30 at p. 12;
Lennox, No. 35 at p. 8) DOE
acknowledges that freight costs are an
additional expense associated with
third-party testing. DOE has determined
that the DOE test procedure is nondestructive and that units can therefore
be recovered after testing. For this
reason, DOE has estimated the cost of
round-trip freight, but does not include
the cost of the unit under test.
Additionally, DOE notes that the test
procedure does not specifically require
use of the unit matched to the unit
under test (i.e., a dedicated condensing
unit matched to a unit cooler under test,
or a unit cooler matched to a dedicated
condensing unit under test).
DOE estimates that the shipping cost
for one walk-in unit from a
manufacturing facility to a test
laboratory can range from $250 to
$1,000 depending on the relative
locations of the two facilities, the weight
and size of the unit being shipped, and
the discounts associated with shipping
multiple units at one time. Thus, DOE
estimates the round-trip freight costs as
ranging from $500 to $2,000.
DOE additionally notes that it has
used third-party laboratory test costs for
its estimate of test costs. DOE
understands that most walk-in
refrigeration system manufacturers have
their own test chambers. In these cases,
DOE expects that its estimate for test
and freight costs is conservative.
L. Effective and Compliance Dates
The effective date for the adopted test
procedure amendment will be 30 days
after publication of this final rule in the
Federal Register. EPCA prescribes that
all representations of energy efficiency
and energy use, including those made
on marketing materials and product
labels, must be made in accordance with
an amended test procedure, beginning
180 days after publication of the final
rule in the Federal Register. (42 U.S.C.
6314(d)(1)) EPCA provides an allowance
for individual manufacturers to petition
DOE for an extension of the 180-day
period if the manufacturer may
experience undue hardship in meeting
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the deadline. (42 U.S.C. 6314(d)(2)) To
receive such an extension, petitions
must be filed with DOE no later than 60
days before the end of the 180-day
period and must detail how the
manufacturer will experience undue
hardship. Id. To the extent the modified
test procedure adopted in this final rule
is required only for the evaluation and
issuance of updated efficiency
standards, compliance with the
amended test procedure does not
require use of such modified test
procedure provisions until the
compliance date of updated standards.
Upon the compliance date of test
procedure provisions in this final rule,
any waivers that had been previously
issued and are in effect that pertain to
issues addressed by such provisions are
terminated. 10 CFR 431.404(h)(3).
Recipients of any such waivers are
required to test the products subject to
the waiver according to the amended
test procedure as of the compliance date
of the amended test procedure. The
amendments adopted in this document
pertain to issues addressed by waivers
granted to the manufacturers listed in
Table III.8.
TABLE III.8—MANUFACTURERS GRANTED WAIVERS AND INTERIM WAIVERS
Manufacturer
Subject
Jamison Door Company ...............
HH Technologies ...........................
Senneca Holdings .........................
Hercules ........................................
HTPG ............................................
Hussmann .....................................
KeepRite ........................................
RefPlus, Inc ...................................
RSG ...............................................
PTO for Door Motors ...................
PTO for Door Motors ...................
PTO for Door Motors ...................
PTO for Door Motors ...................
CO2 Unit Coolers .........................
CO2 Unit Coolers .........................
CO2 Unit Coolers .........................
CO2 Unit Coolers .........................
Multi-Circuit
Single-Package
Dedicated Systems.
Wine Cellar Refrigeration Systems.
Single-Packaged Dedicated Systems.
Wine Cellar Refrigeration Systems.
Wine Cellar Refrigeration Systems.
Wine Cellar Refrigeration Systems.
Wine Cellar Refrigeration Systems.
LRC Coil ........................................
Store It Cold ..................................
CellarPro .......................................
Air Innovations ..............................
Vinotheque ....................................
Vinotemp .......................................
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IV. Procedural Issues and Regulatory
Review
A. Review Under Executive Orders
12866 and 13563
Executive Order (‘‘E.O.’’) 12866,
‘‘Regulatory Planning and Review,’’ as
supplemented and reaffirmed by E.O.
13563, ‘‘Improving Regulation and
Regulatory Review,’’ 76 FR 3821 (Jan.
21, 2011), requires agencies, to the
extent permitted by law, to (1) propose
or adopt a regulation only upon a
reasoned determination that its benefits
justify its costs (recognizing that some
benefits and costs are difficult to
quantify); (2) tailor regulations to
impose the least burden on society,
consistent with obtaining regulatory
objectives, taking into account, among
other things, and to the extent
practicable, the costs of cumulative
regulations; (3) select, in choosing
among alternative regulatory
approaches, those approaches that
maximize net benefits (including
potential economic, environmental,
65 DOE notes that Table III.15 in the April 2022
NOPR should have listed appendix C instead of
appendix C1 as the relevant test procedure for the
LRC Coil waiver. 87 FR 23920, 23977.
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Relevant test
procedure
Case No.
2017–009
2018–001
2020–002
2020–013
2020–009
2020–010
2020–014
2021–006
2022–004
Appendix
Appendix
Appendix
Appendix
Appendix
Appendix
Appendix
Appendix
Appendix
.............
.............
.............
.............
.............
.............
.............
.............
.............
10/31/2023.
10/31/2023.
10/31/2023.
10/31/2023.
10/31/2023.
10/31/2023.
10/31/2023.
10/31/2023.
10/31/2023.
2020–024
Appendix C 65 .........
10/31/2023.
2018–002
Appendix C1 ...........
2019–009
Appendix C1 ...........
2019–010
Appendix C1 ...........
2019–011
Appendix C1 ...........
2020–005
Appendix C1 ...........
Compliance
standards.
Compliance
standards.
Compliance
standards.
Compliance
standards.
Compliance
standards.
public health and safety, and other
advantages; distributive impacts; and
equity); (4) to the extent feasible, specify
performance objectives, rather than
specifying the behavior or manner of
compliance that regulated entities must
adopt; and (5) identify and assess
available alternatives to direct
regulation, including providing
economic incentives to encourage the
desired behavior, such as user fees or
marketable permits, or providing
information upon which choices can be
made by the public. DOE emphasizes as
well that E.O. 13563 requires agencies to
use the best available techniques to
quantify anticipated present and future
benefits and costs as accurately as
possible. In its guidance, the Office of
Information and Regulatory Affairs
(‘‘OIRA’’) in the Office of Management
and Budget (‘‘OMB’’) has emphasized
that such techniques may include
identifying changing future compliance
costs that might result from
technological innovation or anticipated
behavioral changes. For the reasons
stated in the preamble, this final
regulatory action is consistent with
these principles.
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A
A
A
A
C
C
C
C
C
Proposed test procedure
compliance date
date
of
updated
date
of
updated
date
of
updated
date
of
updated
date
of
updated
Section 6(a) of E.O. 12866 also
requires agencies to submit ‘‘significant
regulatory actions’’ to OIRA for review.
OIRA has determined that this final
regulatory action does not constitute a
‘‘significant regulatory action’’ under
section 3(f) of E.O. 12866. Accordingly,
this action was not submitted to OIRA
for review under E.O. 12866.
B. Review Under the Regulatory
Flexibility Act
The Regulatory Flexibility Act (5
U.S.C. 601 et seq.) requires preparation
of a final regulatory flexibility analysis
(‘‘FRFA’’) for any final rule where the
agency was first required by law to
publish a proposed rule for public
comment, unless the agency certifies
that the rule, if promulgated, will not
have a significant economic impact on
a substantial number of small entities.
As required by Executive Order 13272,
‘‘Proper Consideration of Small Entities
in Agency Rulemaking,’’ 67 FR 53461
(August 16, 2002), DOE published
procedures and policies on February 19,
2003, to ensure that the potential
impacts of its rules on small entities are
properly considered during the DOE
rulemaking process. 68 FR 7990. DOE
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ddrumheller on DSK120RN23PROD with RULES2
has made its procedures and policies
available on the Office of the General
Counsel’s website: www.energy.gov/gc/
office-general-counsel. DOE reviewed
this final rule under the provisions of
the Regulatory Flexibility Act and the
procedures and policies published on
February 19, 2003.
The Energy Policy and Conservation
Act, Public Law 94–163, as amended
(‘‘EPCA’’),66 authorizes DOE to regulate
the energy efficiency of a number of
consumer products and certain
industrial equipment. (42 U.S.C. 6291–
6317) Title III, Part C 67 of EPCA, added
by Public Law 95–619, Title IV, section
441(a), established the Energy
Conservation Program for Certain
Industrial Equipment, which sets forth a
variety of provisions designed to
improve energy efficiency. This
equipment includes walk-in coolers and
walk-in freezers (collectively ‘‘WICFs’’
or ‘‘walk-ins’’), the subject of this
document. (42 U.S.C. 6311(1)(G)) DOE is
publishing this final rule in satisfaction
of the 7-year review requirement
specified in EPCA. (42 U.S.C.
6314(b)(1))
DOE has conducted a focused inquiry
into small business manufacturers of the
equipment covered by this rulemaking.
DOE used the Small Business
Administration’s small business size
standards to determine whether any
small entities would be subject to the
requirements of the rule. The size
standards are listed by North American
Industry Classification System
(‘‘NAICS’’) code as well as by industry
description and are available at
www.sba.gov/document/support-tablesize-standards. Manufacturing WICFs is
classified under NAICS 333415, ‘‘AirConditioning and Warm Air Heating
Equipment and Commercial and
Industrial Refrigeration Equipment
Manufacturing.’’ The SBA sets a
threshold of 1,250 employees or fewer
for an entity to be considered as a small
business for this category.68 DOE used
publicly available information to
identify potential small businesses that
manufacture WICFs covered in this
rulemaking. DOE reviewed its
Certification Compliance Database
(‘‘CCD’’) 69 and the California Energy
66 All references to EPCA in this document refer
to the statute as amended through the Energy Act
of 2020, Public Law 116–260 (Dec. 27, 2020), which
reflect the last statutory amendments that impact
Parts A and A–1 of EPCA.
67 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
68 The size standards are listed by NAICS code
and industry description and are available at:
www.sba.gov/document/support-table-sizestandards. (Last accessed Oct. 11, 2022.)
69 U.S. Department of Energy Compliance
Certification Database, available at
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Commission’s Modernized Appliance
Efficiency Database System
(‘‘MAEDbS’’) 70 to identify
manufacturers. DOE also used
subscription-based business information
tools (e.g., reports from Dun &
Bradstreet 71) to determine headcount
and revenue of the small businesses.
Using these data sources, DOE
identified 78 original equipment
manufacturers (‘‘OEMs’’) of WICFs that
could be potentially affected by this
rulemaking. DOE screened out
companies that do not meet the
definition of a ‘‘small business’’ or are
foreign-owned and operated. Of these 78
OEMs, 57 are small, domestic
manufacturers. DOE notes that some
manufacturers may produce more than
one of the principal components of
WICFs: doors, panels, and refrigeration
systems. Forty-one of the small,
domestic OEMs manufacture doors; 35
of the small, domestic OEMs
manufacture panels; and 18 of the small,
domestic OEMs manufacture
refrigeration systems.
In response to the Initial Regulatory
Flexibility Analysis published as part of
the April 2022 NOPR, AHRI noted that
while they are unsure of the exact
number of small OEMs of WICF panels,
doors, and refrigeration systems, they
acknowledge that small OEMs represent
a significant portion of the WICF
market. AHRI asserted that small OEMs
would be negatively impacted by what
AHRI characterized as the added
complexity and related costs. AHRI also
noted that EPA and DOE regulatory
actions that are not yet fully resolved
have impact in a relatively immediate
timeframe. (AHRI, No. 30 at p. 12)
DOE agrees with AHRI that small
businesses account for the majority of
WICF component OEMs operating in the
United States. Regarding AHRI’s
concerns about complexity, DOE
evaluates test procedures for each type
of covered equipment, including WICFs,
to determine whether amended test
procedures would more accurately or
fully comply with the requirements for
the test procedures to not be unduly
burdensome to conduct and be
reasonably designed to produce test
results that reflect energy efficiency,
energy use, and estimated operating
costs during a representative average
use cycle. (42 U.S.C. 6314(a)(1)) DOE
www.regulations.doe.gov/certification-data/
#q=Product_Group_s%3A*. (Last accessed March
16, 2022.)
70 California Energy Commission’s Modernized
Appliance Efficiency Database System, available at
cacertappliances.energy.ca.gov/Pages/Search/
AdvancedSearch.aspx. (Last accessed Nov. 1, 2021.)
71 D&B Hoovers reports are available at
app.dnbhoovers.com. (Last accessed Oct. 12, 2022.)
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has determined that the amendments in
this final rule would improve the
accuracy, reproducibility, and
representativeness of test procedure
results, and will not be unduly
burdensome for manufacturers to
conduct. DOE has determined that the
amendments outlined in this final rule
will not require retesting or rerating of
units.
Regarding the impact of EPA
refrigerant regulation and other DOE
rulemaking actions on small businesses,
DOE would consider the impact on
manufacturers of multiple product/
equipment-specific regulatory actions
pursuant to section 13(g) in appendix A
to subpart C of part 430, in any
subsequent energy conservation
standards rulemaking analysis for
WICFs.
RSG commented that it considers
DOE’s door, panel, and refrigeration
system cost estimates to be very low.
For refrigeration systems, RSG further
stated that there are few outside labs
capable of testing to the degree that DOE
requires. (RSG, No. 41 at p. 3) DOE
notes that the estimated test costs were
based on actual laboratory quotes,
which DOE has determined are
representative of the pricing available to
the industry as a whole. Additionally,
DOE is aware of third-party laboratories
that have the capability to test to the
current DOE test procedure.
Doors
DOE has determined that retesting
and recertification would not be
required for walk-in cooler and freezer
doors as a result of this rulemaking.
DOE is adopting the following
amendments to appendix A for walk-in
cooler and freezer doors:
1. Referencing NFRC 102–2020 for the
determination of U-factor;
2. Including AEDM provisions for
manufacturers to alternately determine
the total energy consumption of display
and non-display doors;
3. Providing additional detail for
determining the area used to convert Ufactor into conduction load, As, to
differentiate it from the area used to
determine compliance with the
standards, Add or And; and
4. Specifying a PTO value of 97
percent for door motors.
DOE has determined that these
amendments would not increase testing
costs per basic model relative to the
current DOE test procedure in appendix
A.72 Items 1 and 3, referencing NFRC
72 DOE estimates the cost of one test to determine
energy consumption of a walk-in door, including
one physical U-factor test per NFRC 102–2020, to
be $5,000. Per the sampling requirements specified
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102–2020 and additional detail on the
area used to convert U-factor into a
conduction load, improves the
consistency, reproducibility, and
representativeness of test procedure
results. Item 2, including AEDM
provisions, intends to provide
manufacturers with the flexibility to use
an alternative method that gives the best
agreement for their doors. Item 4, by
including a PTO value of 97 percent,
intends to provide a more representative
and consistent means for comparison of
walk-in door performance for doors
with motors.
DOE expects certification costs for
door manufacturers would either remain
the same or be reduced, depending on
whether manufacturers have been able
to achieve the agreement between Ufactors simulated using the method in
NFRC 100 and U-factors tested using
NFRC 102. Manufacturers of doors that
have been able to achieve the specified
agreement 73 between U-factors
simulated using the method in NFRC
100 and U-factors tested using NFRC
102 would be able to continue using the
simulation method in NFRC 100,
provided that the simulation method
also meets the basic requirements
proposed for an AEDM in 10 CFR
429.53 and 429.70(f). For manufacturers
of doors that have not been able to
achieve the specified agreement
between U-factors simulated using the
method in NFRC 100 and U-factors
tested using NFRC 102, DOE estimates
that the test burden would decrease.
With the new test procedure,
manufacturers who would have
otherwise been required to physically
test every walk-in door basic model
could develop an AEDM for rating their
basic models of walk-in doors consistent
with the proposed provisions in 10 CFR
429.53 and 429.70(f). DOE estimates the
per-manufacturer cost to develop and
validate an AEDM for a single validation
class of walk-in doors to be $11,100, in
addition to an estimated $1,600 to
$5,000 in shipping costs.74 DOE
estimates an additional cost to
determine energy consumption of a
walk-in door using an AEDM to be $46
per basic model.75
DOE expects that the additional detail
provided for determining the area used
to convert U-factor into conduction
load, As, would not result in changes
that require manufacturers to re-certify
equipment. Manufacturers would be
able to rely on data generated under the
current test procedure for equipment
already certified.
For walk-in doors with motors, DOE
has determined that the amendments
described in section III of this final rule
would either not change the measured
energy consumption or would result in
a lower measured energy consumption
and therefore, would not require
retesting or recertification as a result of
DOE’s adoption of the amendments to
the test procedures. New testing is only
required if the manufacturer wishes to
make claims using the new, more
efficient rating. Additionally, DOE has
determined the amendments would not
increase the cost of testing for doors
with motors.
DOE concludes that manufacturers of
WICF doors, including small
manufacturers, will not incur retesting
and recertification costs as a result of
this final rule.
at 10 CFR 429.53(a)(3)(ii) and 429.11(b),
manufacturers are required to test at least two units
to determine the rating for a basic model, except
where only one unit of the basic model is produced.
73 Section 4.7.1 of NFRC 100 requires that the
accepted difference between the tested U-factor and
the simulated U-factor be (a) 0.03 Btu/(h-ft2 °F) for
simulated U-factors that are 0.3 Btu/(h-ft2 °F) or
less, or (b) 10 percent of the simulated U-factor for
simulated U-factors greater than 0.3 Btu/(h-ft2 °F).
This agreement must match for the baseline product
in a product line. Per NFRC 100, the baseline
product is the individual product selected for
validation; it is not synonymous with ‘‘basic
model’’ as defined in 10 CFR 431.302.
74 DOE estimates that the shipping cost for a
walk-in box, typically made up of multiple panels
and a door, from a manufacturing facility to a test
lab can range from $800 to $2,500 depending on the
relative locations of the two facilities, the weight
and size of the unit being shipped, and the
discounts associated with shipping multiple units
at one time. This means that each estimated test
cost would increase from $1,600 to $5,000 dollars
when shipping a unit for test to and from a thirdparty lab.
75 DOE estimated initial costs to validate an
AEDM assuming 24 hours of general time to
develop and validate an AEDM based on existing
simulation tools. DOE estimated the cost of an
engineering calibration technician fully burdened
wage of $46 per hour plus the cost of third-party
physical testing of two basic models per proposed
validation class. DOE estimated the additional per
basic model cost to determine efficiency using an
AEDM assuming 1 hour per basic model at the cost
of an engineering calibration technician wage of $46
per hour.
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Panels
In this final rule, DOE is amending
the existing test procedure in appendix
B for measuring the R-value of
insulation of panels by:
1. Incorporating by reference the
updated version of the applicable
industry test method, ASTM C518–17;
2. Including provisions specific to
measurement of test specimen and total
insulation thickness; and
3. Providing specifications for
determining the parallelism and flatness
of the test specimen.
The first item incorporates by
reference the most up-to-date version of
the industry standards currently
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28829
referenced in the DOE test procedure.
Items 2 and 3 include additional
instructions intended to improve
consistency and reproducibility of test
procedure results.
DOE has concluded that the
amendments will not change efficiency
ratings for walk-in panels, and therefore
will not require rerating as result of
DOE’s adoption of this amendment to
the test procedure. Therefore, DOE has
determined that these amendments will
not add any additional testing costs to
small business manufacturers of WICF
panels.
Refrigeration Systems
In this final rule, DOE is adopting
changes to appendix C that DOE has
determined would improve the accuracy
and reproducibility of the test results
and would not be unduly burdensome
for manufacturers to conduct. DOE has
determined that these changes would
not impact testing cost. Additionally,
the amended appendix C, measuring
AWEF per AHRI 1250–2009, does not
contain any changes that would require
retesting or rerating.
DOE is also adopting, through
incorporations by reference, certain
provisions of AHRI 1250–2020 in
appendix C1 that will amend the
existing test procedure for walk-in
cooler and freezer refrigeration systems.
DOE notes that the new appendix C1,
which establishes new energy efficiency
metric AWEF2, would increase testing
costs for certain refrigeration system
equipment types. This final rule does
not require manufacturers to rate
equipment using appendix C1. If DOE
were to adopt a future energy
conservation standard using the AWEF2
metric, that energy conversation
standard will cause manufacturers to
incur costs for retesting and
recertification at the time when the
amended standards take effect. The cost
of retesting and recertification based on
appendix C1 would be incorporated into
the analysis of the energy conservation
standard adopting the AWEF2 metric,
should DOE choose to establish
standard using that metric.
Although this test procedure final rule
does not require the use of appendix C1
and manufacturers, including small
manufacturers, will not incur retesting
or recertification costs based on the
AWEF2 metric at this time, DOE
discusses the potential impacts of
adopting certain changes in the new
appendix C1 in this section.
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As discussed previously in this final
rule, DOE is adopting off-cycle test
provisions in AHRI 1250–2020 for walkin refrigeration systems. The current test
procedure requires off-cycle power to be
measured at the 95 °F ambient
condition. The new test procedure
requires off-cycle to be measured at
95 °F, 59 °F, and 35 °F ambient
conditions for outdoor dedicated
condensing units, outdoor matched pair
systems, and outdoor dedicated
systems. The matched pair and singlepackaged dedicated systems include
high-temperature refrigeration systems.
When the waivers for these hightemperature refrigeration systems were
granted, only one off-cycle test was
required; therefore, manufacturers with
waivers would be required to conduct
additional testing as compared to the
alternate test procedure currently
required. DOE estimates that measuring
off-cycle power at these additional
ambient conditions may increase thirdparty lab test cost by $1,000 per unit to
a total cost of $11,000 per unit for
outdoor dedicated condensing units,
outdoor matched pair systems, and
outdoor single-packaged dedicated
systems. The physical testing cost
would be $22,000 per basic model for
outdoor dedicated condensing units,
outdoor matched pair systems, and
outdoor single-packaged dedicated
systems, in addition to an estimated
$1,000 to $4,000 in round trip shipping
costs.76
However, manufacturers are not
required to perform laboratory testing
on all basic models. In accordance with
10 CFR 429.53, WICF refrigeration
system manufacturers may elect to use
AEDMs. DOE estimates the permanufacturer cost to develop and
validate an AEDM for outdoor dedicated
condensing units and outdoor matched
pair systems to be approximately
$24,581,77 in addition to an estimated
$1,000 to $4,000 in round trip shipping
costs.78 DOE estimates an additional
cost of approximately $46 per basic
model 79 for determining energy
efficiency of a given basic model using
the validated AEDM.
DOE estimated the range of potential
costs for the five small OEMs that
manufacture outdoor dedicated
condensing units, outdoor matched pair
systems, and outdoor single-packaged
dedicated systems. When developing
cost estimates for the small OEMs, DOE
considers the cost to update the existing
AEDM simulation tool, the costs to
validate the AEDM through physical
testing (including shipping costs to and
from the third-party laboratory), and the
cost to rate basic models using the
AEDM. DOE assumes a high-cost
scenario where manufacturers would be
required to develop AEDMs for six
validation classes.
DOE estimates the impacts based on
basic model counts and company
revenue. Table IV.1 summarizes DOE’s
estimates for the five identified small
businesses. On average, testing costs
represent less than 1 percent of annual
revenue for a typical small business.
As previously discussed, the
procedure in appendix C1 would only
require retesting or recertification when
and if a future energy conservation
standard takes effect.
TABLE IV.1—POTENTIAL SMALL BUSINESS RE-RATING COSTS (2022$) AS A RESULT OF OFF-CYCLE REFRIGERATION
SYSTEM POWER REQUIREMENTS
Re-rating
estimate
($MM)
Small domestic OEM
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Manufacturer
Manufacturer
Manufacturer
Manufacturer
Manufacturer
1
2
3
4
5
.........................................................................................................................................
.........................................................................................................................................
.........................................................................................................................................
.........................................................................................................................................
.........................................................................................................................................
0.16
0.16
0.23
0.16
0.16
Estimated
annual
revenue
($MM)
12.0
110.3
88.7
116.2
156.3
Percent of
annual
revenue
1.4
0.1
0.3
0.1
0.1
As also discussed in the final rule,
DOE is adopting the single-packaged
dedicated system test procedure for
walk-ins in AHRI 1250–2020. The
procedure requires air enthalpy tests to
be used as the primary test method. In
the current test procedure, singlepackaged dedicated systems use
refrigerant enthalpy as the primary test
method. DOE does not estimate a
difference in physical testing costs
between air and refrigerant enthalpy
testing of single-packaged dedicated
systems. DOE estimates the per-unit
third party lab test cost to be $11,000 for
outdoor single-packaged units and
$6,500 for indoor single-packaged units.
The physical testing cost would be
$22,000 per basic model for outdoor
single-packaged dedicated systems and
$13,000 per basic model for indoor
package systems, in addition to an
estimated $1,000 to $4,000 in round trip
shipping costs for each class.80
However, should a manufacturer
choose to use an AEDM, it may incur
additional costs regarding the
development and validation of new
AEDMs for single-packaged dedicated
systems. DOE estimates the per
manufacturer cost to develop and
validate an AEDM to be $24,580 for
outdoor single-packaged units and
$15,580 for indoor single-packaged
units, in addition to an estimated $1,000
to $4,000 in round trip shipping costs.81
DOE estimates an additional cost of
76 The cost to test one unit is $11,000, plus an
estimated $500 to $2,000 for shipping the
refrigeration system to and from the third-party lab.
Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 429.11(b), manufacturers are
required to test at least two units to determine the
rating for a basic model, except where only one unit
of the basic model is produced.
77 Outdoor single-packaged systems are also
impacted by the proposed adoption of AHRI 1250–
2020 single-packaged test procedure for walk-in
cooler and freezer refrigeration systems. The
combined potential cost increase for outdoor single-
packaged systems is presented in the next
paragraph.
78 Shipping costs associated with third-party
physical testing of two units per validation class (as
required in 10 CFR 429.70(c)(2)(iv)).
79 DOE estimated initial costs to validate an
AEDM assuming 40 hours of general time to
develop an AEDM based on existing simulation
tools and 16 hours to validate two basic models
within that AEDM at the cost of an engineering
calibration technician fully burdened wage of $46
per hour plus the cost of third-party physical testing
of two units per validation class (as required in 10
CFR 429.70(c)(2)(iv)). DOE estimated the additional
per basic model cost to determine efficiency using
an AEDM assuming 1 hour per basic model at the
cost of an engineering calibration technician wage
of $46 per hour.
80 Per the sampling requirements specified at 10
CFR 429.53(a)(2)(ii) and 429.11(b), manufacturers
are required to test at least two units to determine
the rating for a basic model, except where only one
unit of the basic model is produced.
81 Shipping costs associated with third-party
physical testing of two units per validation class (as
required in 10 CFR 429.70(c)(2)(iv)).
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approximately $46 per basic model 82
for determining energy efficiency using
the validated AEDM.
DOE estimated the range of potential
costs for the two domestic, small OEMs
that manufacture single-packaged
dedicated systems. When developing
cost estimates for the small OEMs, DOE
considered the cost to update the
existing AEDM simulation tool, the
costs to validate the AEDM through
physical testing (including shipping
costs to and from the third-party
laboratory), and the cost to rate basic
models using the AEDM.
Both small businesses manufacture
indoor and outdoor, low- and mediumtemperature, single-packaged dedicated
systems. One small business
manufactures 28 basic models of singlepackaged dedicated systems with an
estimated annual revenue of $110
million. Therefore, DOE estimates the
associated re-rating costs for this
manufacturer to be approximately
$91,250 when making use of AEDMs.
The cost for this manufacturer
represents less than 1 percent of annual
revenue.
The second small business
manufactures 38 basic models of singlepackaged dedicated systems with an
estimated annual revenue of $156
million. Therefore, DOE estimates the
associated re-rating costs for this
manufacturer to be approximately
$91,700 when making use of AEDMs.
The cost for this manufacturer
represents less than 1 percent of annual
revenue.
As previously discussed, the
procedure in appendix C1 would only
require retesting or recertification when
and if a future energy conservation
standard takes effect.
As also discussed in this final rule,
DOE is adopting test procedures for CO2
unit coolers and high-temperature
refrigeration systems. DOE estimates
that the average third-party lab per unit
test cost would be $11,000 for a hightemperature matched pair or singlepackaged dedicated system, $6,000 for a
high-temperature unit cooler tested
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81 Shipping costs associated with third-party
physical testing of two units per validation class (as
required in 10 CFR 429.70(c)(2)(iv)).
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alone, $6,500 for a low-temperature CO2
unit cooler, and $6,000 for a mediumtemperature CO2 unit cooler. As
discussed previously, DOE has granted
waivers to certain manufacturers for
both high-temperature refrigeration
systems and CO2 unit coolers. The test
procedures being adopted are consistent
with the alternate test procedures
included in the granted waivers. For
those manufacturers who have been
granted a test procedure waiver for this
equipment, DOE expects that there
would be no additional test burden.
However, DOE expects that there would
be additional testing costs for any
manufacturers of these products who
have not submitted or been granted a
test procedure waiver at the time this
test procedure is finalized. DOE
estimates these manufacturers may
incur rating expenses up to the
following estimates, in addition to an
estimated $5,000 to $2,000 in shipping
costs for each class.83
• $22,000 per basic model for a hightemperature matched pair or singlepackaged dedicated system; 84
• $12,000 per basic model for a hightemperature unit cooler tested alone; 85
• $13,000 per basic model for a lowtemperature CO2 unit cooler; 86 and
• $12,000 per basic model for a
medium-temperature CO2 unit cooler.87
However, manufacturers are not
required to perform laboratory testing
on all basic models. In accordance with
10 CFR 429.53, WICF refrigeration
system manufacturers may elect to use
AEDMs. DOE estimates the per82 DOE estimated initial costs to validate an
AEDM assuming 40 hours of general time to
develop an AEDM based on existing simulation
tools and 16 hours to validate two basic models
within that AEDM at the cost of an engineering
calibration technician fully burdened wage of $46
per hour plus the cost of third-party physical testing
of two units per validation class (as required in 10
CFR 429.70(c)(2)(iv)). DOE estimated the additional
per basic model cost to determine efficiency using
an AEDM assuming 1 hour per basic model at the
cost of an engineering calibration technician wage
of $46 per hour.
83 The cost to ship one unit to and from the thirdparty lab is approximately $500 to $2,000. Per the
sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 429.11(b), manufacturers are
required to test at least two units to determine the
rating for a basic model, except where only one unit
of the basic model is produced.
84 Per the sampling requirements specified at 10
CFR 429.53(a)(2)(ii) and 429.11(b), manufacturers
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28831
manufacturer cost to develop and
validate an AEDM for high-temperature
systems and low- and mediumtemperature CO2 unit coolers to be
$24,580 per validation class, in addition
to an estimated $1,000 to $4,000 in
round trip shipping costs.88 DOE
estimates an additional cost of
approximately $46 per basic model 89 for
determining energy efficiency using the
validated AEDM.
DOE estimated the potential costs to
manufacturers of high-temperature units
as a result of off-cycle requirements
using an AEDM. Specifically, DOE
estimated the range of potential costs for
the five identified domestic, small
OEMs that manufacture hightemperature units. When developing
cost estimates for the small OEMs, DOE
considers the cost to develop the AEDM
simulation tool, the costs to validate the
AEDM through physical testing
(including shipping costs to and from
the third-party laboratory), and the cost
to rate basic models using the AEDM.
DOE assumes a scenario where
manufacturers would be required to
develop AEDMs for three validation
classes.
DOE estimated the impacts based on
basic model counts and company
revenue. Table IV.2 summarizes DOE’s
estimates for the five identified small
businesses. On average, testing costs
represent approximately 1.3 percent of
annual revenue for a typical small
business.
As previously discussed, the
procedure in appendix C1 would only
require retesting or recertification when
and if a future energy conservation
standard takes effect.
88 Shipping costs associated with third-party
physical testing of two units per validation class (as
required in 10 CFR 429.70(c)(2)(iv)).
89 DOE estimated initial costs to validate an
AEDM assuming 40 hours of general time to
develop an AEDM based on existing simulation
tools and 16 hours to validate two basic models
within that AEDM at the cost of an engineering
calibration technician fully burdened wage of $46
per hour plus the cost of third-party physical testing
of two units per validation class (as required in 10
CFR 429.70(c)(2)(iv)). DOE estimated the additional
per basic model cost to determine efficiency using
an AEDM assuming 1 hour per basic model at the
cost of an engineering calibration technician wage
of $46 per hour.
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TABLE IV.2—POTENTIAL SMALL BUSINESS RE-RATING COSTS (2022$) FOR HIGH-TEMPERATURE REFRIGERATION
SYSTEMS
Re-rating
estimate
($MM)
Small domestic OEM
Manufacturer
Manufacturer
Manufacturer
Manufacturer
Manufacturer
A
B
C
D
E
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
Manufacturers of CO2 unit coolers
may also choose to utilize an AEDM.
Furthermore, AEDM unit cooler
validation classes do not distinguish
between CO2 unit coolers and non-CO2
unit coolers. Therefore, manufacturers
of CO2 unit coolers may use the same
validation classes as non-CO2 unit
coolers.
On the basis that the adopted test
procedure changes will not require
retesting and recertification, DOE
certifies that this final rule does not
have a ‘‘significant economic impact on
a substantial number of small entities,’’
and that the preparation of a FRFA is
not warranted. DOE will transmit a
certification and supporting statement
of factual basis to the Chief Counsel for
Advocacy of the Small Business
Administration for review under 5
U.S.C. 605(b).
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C. Review Under the Paperwork
Reduction Act of 1995
Manufacturers of walk-ins must
certify to DOE that their products
comply with any applicable energy
conservation standards. To certify
compliance, manufacturers must first
obtain test data for their products
according to the DOE test procedures,
including any amendments adopted for
those test procedures. DOE has
established regulations for the
certification and recordkeeping
requirements for all covered consumer
products and commercial equipment,
walk-ins. (See generally 10 CFR part
429.) The collection-of-information
requirement for the certification and
recordkeeping is subject to review and
approval by OMB under the Paperwork
Reduction Act (PRA). This requirement
has been approved by OMB under OMB
Control Number 1910–1400. Public
reporting burden for the certification is
estimated to average 35 hours per
response, including the time for
reviewing instructions, searching
existing data sources, gathering and
maintaining the data needed, and
completing and reviewing the collection
of information.
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DOE is not amending the certification
or reporting requirements for walk-ins
in this final rule. Instead, DOE may
consider proposals to amend the
certification requirements and reporting
for walk-ins under a separate
rulemaking regarding appliance and
equipment certification. DOE will
address changes to OMB Control
Number 1910–1400 at that time, as
necessary.
Notwithstanding any other provision
of the law, no person is required to
respond to, nor shall any person be
subject to a penalty for failure to comply
with, a collection of information subject
to the requirements of the PRA, unless
that collection of information displays a
currently valid OMB Control Number.
D. Review Under the National
Environmental Policy Act of 1969
In this final rule, DOE establishes test
procedure amendments that it expects
will be used to develop and implement
future energy conservation standards for
walk-ins. DOE has determined that this
rule falls into a class of actions that are
categorically excluded from review
under the National Environmental
Policy Act of 1969 (42 U.S.C. 4321 et
seq.) and DOE’s implementing
regulations at 10 CFR part 1021.
Specifically, DOE has determined that
adopting test procedures for measuring
energy efficiency of consumer products
and industrial equipment is consistent
with activities identified in 10 CFR part
1021, appendix A to subpart D, A5 and
A6. Accordingly, neither an
environmental assessment nor an
environmental impact statement is
required.
E. Review Under Executive Order 13132
Executive Order 13132, ‘‘Federalism,’’
64 FR 43255 (August 4, 1999), imposes
certain requirements on agencies
formulating and implementing policies
or regulations that preempt State law or
that have federalism implications. The
Executive order requires agencies to
examine the constitutional and statutory
authority supporting any action that
would limit the policymaking discretion
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0.089
0.088
0.089
0.091
0.089
Estimated
annual
revenue
($MM)
3.9
3.6
11.5
10.8
208.0
Percent of
annual
revenue
2.3
2.5
0.8
0.8
0.0
of the States and to carefully assess the
necessity for such actions. The
Executive order also requires agencies to
have an accountable process to ensure
meaningful and timely input by State
and local officials in the development of
regulatory policies that have Federalism
implications. On March 14, 2000, DOE
published a statement of policy
describing the intergovernmental
consultation process it will follow in the
development of such regulations. 65 FR
13735. DOE examined this final rule
and determined that it will not have a
substantial direct effect on the States, on
the relationship between the National
Government and the States, or on the
distribution of power and
responsibilities among the various
levels of government. EPCA governs and
prescribes Federal preemption of State
regulations as to energy conservation for
the equipment that are the subject of
this final rule. States can petition DOE
for exemption from such preemption to
the extent, and based on criteria, set
forth in EPCA. (42 U.S.C. 6297(d)) No
further action is required by Executive
Order 13132.
F. Review Under Executive Order 12988
Regarding the review of existing
regulations and the promulgation of
new regulations, section 3(a) of
Executive Order 12988, ‘‘Civil Justice
Reform,’’ 61 FR 4729 (Feb. 7, 1996),
imposes on Federal agencies the general
duty to adhere to the following
requirements: (1) eliminate drafting
errors and ambiguity; (2) write
regulations to minimize litigation; (3)
provide a clear legal standard for
affected conduct rather than a general
standard; and (4) promote simplification
and burden reduction. Section 3(b) of
Executive Order 12988 specifically
requires that Executive agencies make
every reasonable effort to ensure that the
regulation (1) clearly specifies the
preemptive effect, if any; (2) clearly
specifies any effect on existing Federal
law or regulation; (3) provides a clear
legal standard for affected conduct
while promoting simplification and
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burden reduction; (4) specifies the
retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses
other important issues affecting clarity
and general draftsmanship under any
guidelines issued by the Attorney
General. Section 3(c) of Executive Order
12988 requires Executive agencies to
review regulations in light of applicable
standards in sections 3(a) and 3(b) to
determine whether they are met or it is
unreasonable to meet one or more of
them. DOE has completed the required
review and determined that, to the
extent permitted by law, this final rule
meets the relevant standards of
Executive Order 12988.
G. Review Under the Unfunded
Mandates Reform Act of 1995
Title II of the Unfunded Mandates
Reform Act of 1995 (‘‘UMRA’’) requires
each Federal agency to assess the effects
of Federal regulatory actions on State,
local, and Tribal governments and the
private sector. Public Law 104–4, sec.
201 (codified at 2 U.S.C. 1531). For a
regulatory action resulting in a rule that
may cause the expenditure by State,
local, and Tribal governments, in the
aggregate, or by the private sector of
$100 million or more in any one year
(adjusted annually for inflation), section
202 of UMRA requires a Federal agency
to publish a written statement that
estimates the resulting costs, benefits,
and other effects on the national
economy. (2 U.S.C. 1532(a), (b)) The
UMRA also requires a Federal agency to
develop an effective process to permit
timely input by elected officers of State,
local, and Tribal governments on a
proposed ‘‘significant intergovernmental
mandate,’’ and requires an agency plan
for giving notice and opportunity for
timely input to potentially affected
small governments before establishing
any requirements that might
significantly or uniquely affect small
governments. On March 18, 1997, DOE
published a statement of policy on its
process for intergovernmental
consultation under UMRA. 62 FR
12820; also available at
www.energy.gov/gc/office-generalcounsel. DOE examined this final rule
according to UMRA and its statement of
policy and determined that the rule
contains neither an intergovernmental
mandate, nor a mandate that may result
in the expenditure of $100 million or
more in any year, so these requirements
do not apply.
H. Review Under the Treasury and
General Government Appropriations
Act, 1999
Section 654 of the Treasury and
General Government Appropriations
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Act, 1999 (Pub. L. 105–277) requires
Federal agencies to issue a Family
Policymaking Assessment for any rule
that may affect family well-being. This
final rule will not have any impact on
the autonomy or integrity of the family
as an institution. Accordingly, DOE has
concluded that it is not necessary to
prepare a Family Policymaking
Assessment.
I. Review Under Executive Order 12630
DOE has determined, under Executive
Order 12630, ‘‘Governmental Actions
and Interference with Constitutionally
Protected Property Rights,’’ 53 FR 8859
(March 18, 1988), that this regulation
will not result in any takings that might
require compensation under the Fifth
Amendment to the U.S. Constitution.
J. Review Under Treasury and General
Government Appropriations Act, 2001
Section 515 of the Treasury and
General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides
for agencies to review most
disseminations of information to the
public under guidelines established by
each agency pursuant to general
guidelines issued by OMB. OMB’s
guidelines were published at 67 FR
8452 (Feb. 22, 2002), and DOE’s
guidelines were published at 67 FR
62446 (Oct. 7, 2002). Pursuant to OMB
Memorandum M–19–15, Improving
Implementation of the Information
Quality Act (April 24, 2019), DOE
published updated guidelines which are
available at www.energy.gov/sites/prod/
files/2019/12/f70/
DOE%20Final%20Updated%20IQA
%20Guidelines%20Dec%202019.pdf.
DOE has reviewed this final rule under
the OMB and DOE guidelines and has
concluded that it is consistent with
applicable policies in those guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ‘‘Actions
Concerning Regulations That
Significantly Affect Energy Supply,
Distribution, or Use,’’ 66 FR 28355 (May
22, 2001), requires Federal agencies to
prepare and submit to OMB, a
Statement of Energy Effects for any
significant energy action. A ‘‘significant
energy action’’ is defined as any action
by an agency that promulgated or is
expected to lead to promulgation of a
final rule, and that (1) is a significant
regulatory action under Executive Order
12866, or any successor order; and (2)
is likely to have a significant adverse
effect on the supply, distribution, or use
of energy; or (3) is designated by the
Administrator of OIRA as a significant
energy action. For any significant energy
action, the agency must give a detailed
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28833
statement of any adverse effects on
energy supply, distribution, or use if the
regulation is implemented, and of
reasonable alternatives to the action and
their expected benefits on energy
supply, distribution, and use.
This regulatory action is not a
significant regulatory action under
Executive Order 12866. Moreover, it
would not have a significant adverse
effect on the supply, distribution, or use
of energy, nor has it been designated as
a significant energy action by the
Administrator of OIRA. Therefore, it is
not a significant energy action, and,
accordingly, DOE has not prepared a
Statement of Energy Effects.
L. Review Under Section 32 of the
Federal Energy Administration Act of
1974
Under section 301 of the Department
of Energy Organization Act (Pub. L. 95–
91; 42 U.S.C. 7101), DOE must comply
with section 32 of the Federal Energy
Administration Act of 1974, as amended
by the Federal Energy Administration
Authorization Act of 1977. (15 U.S.C.
788; ‘‘FEAA’’) Section 32 essentially
provides in relevant part that, where a
rule authorizes or requires use of
commercial standards, the rulemaking
must inform the public of the use and
background of such standards. In
addition, section 32(c) requires DOE to
consult with the Attorney General and
the Chairman of the Federal Trade
Commission (‘‘FTC’’) concerning the
impact of the commercial or industry
standards on competition.
The modifications to the test
procedure for walk-ins adopted in this
final rule incorporates testing methods
contained in certain sections of the
following commercial standards: NFRC
102–2020, ASTM C1199–14, ASTM
C518–17, AHRI 1250–2020, AHRI 1250–
2020, ANSI/ASHRAE 37–2009, and
ANSI/ASHRAE 16–2016. DOE has
evaluated these standards and is unable
to conclude whether it fully complies
with the requirements of section 32(b) of
the FEAA (i.e., whether it was
developed in a manner that fully
provides for public participation,
comment, and review). DOE has
consulted with both the Attorney
General and the Chairman of the FTC
about the impact on competition of
using the methods contained in these
standards.
M. Congressional Notification
As required by 5 U.S.C. 801, DOE will
report to Congress on the promulgation
of this rule before its effective date. The
report will state that it has been
determined that the rule is not a ‘‘major
rule’’ as defined by 5 U.S.C. 804(2).
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N. Description of Materials Incorporated
by Reference
AHRI Standard 1250 (I–P)-2009 is an
industry-accepted test procedure for
measuring the performance of walk-in
cooler and walk-in freezer refrigeration
systems. Specifically, the test procedure
codified by this final rule references
AHRI 1250–2009 for testing walk-in
refrigeration units. AHRI 1250–2009 is
reasonably available on AHRI’s website
at www.ahrinet.org/standards/searchstandards.
AHRI Standard 1250–2020 is an
industry-accepted test procedure for
measuring the performance of walk-in
cooler and walk-in freezer refrigeration
systems. Specifically, the test procedure
codified by this final rule references
AHRI 1250–2020 for testing walk-in
refrigeration units. AHRI 1250–2020 is
reasonably available on AHRI’s website
at www.ahrinet.org/standards/searchstandards.
ANSI/AHRI Standard 420–2008 is an
industry-accepted test procedure for
rating the performance of forcedcirculation free-delivery unit coolers for
refrigeration and is referenced by AHRI
1250–2009. Specifically, the test
procedure codified by this final rule
references AHRI 420–2008 for the
information that should be recorded
when testing unit coolers. AHRI 420–
2008 is reasonably available on AHRI’s
website at www.ahrinet.org/standards/
search-standards.
ANSI/ASHRAE Standard 16–2016 is
an industry-accepted test procedure for
measuring cooling and heating capacity
of room air conditioners, packaged
terminal air conditioners, and packaged
terminal heat pumps and is referenced
by AHRI 1250–2020. Specifically, the
test procedure codified by this final rule
references ANSI/ASHRAE 16–2016 for
test provisions related the capacity
measurement of single-packaged
dedicated systems for the appendix C1
test procedure. ANSI/ASHRAE 16–2016
is reasonably available on ASHRAE’s
website at www.ashrae.org.
ANSI/ASHRAE Standard 23.1–2010 is
an industry-accepted test procedure for
rating the performance of positive
displacement refrigerant compressors
and condensing units that operate at
refrigerant subcritical temperatures and
is referenced by AHRI 1250–2009 and
AHRI 1250–2020. Specifically, the test
procedure codified by this final rule
references ANSI/ASHRAE 23.1–2010 for
test provisions related to capacity
measurement of condensing units using
the compressor calibration method.
ANSI/ASHRAE 23.1–2010 is reasonably
available on ASHRAE’s website at
www.ashrae.org.
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ANSI/ASHRAE Standard 37–2009 is
an industry-accepted test procedure for
testing and rating air-conditioning and
heat pump equipment and is referenced
by AHRI 1250–2020. Specifically, the
test procedure codified by this final rule
references ANSI/ASHRAE 37–2009 for
test provisions related to capacity
measurement of single-packaged
dedicated systems for the appendix C1
test procedure. ANSI/ASHRAE 37–2009
is reasonably available on ASHRAE’s
website at www.ashrae.org.
ANSI/ASHRAE Standard 41.1–2013 is
an industry-accepted test procedure for
measuring temperature and is
referenced by AHRI 1250–2020.
Specifically, the test procedure codified
by this final rule references ANSI/
ASHRAE 41.1–2013 for temperature
measurements for all refrigeration unit
tests. ANSI/ASHRAE 41.1–2013 is
reasonably available on ASHRAE’s
website at www.ashrae.org.
ANSI/ASHRAE Standard 41.3–2014 is
an industry-accepted test procedure for
measuring pressure and is referenced by
AHRI 1250–2020. Specifically, the test
procedure codified by this final rule
references ANSI/ASHRAE 41.3–2014 for
pressure measurements for all
refrigeration unit tests. ANSI/ASHRAE
41.3–12014 is reasonably available on
ASHRAE’s website at www.ashrae.org.
ANSI/ASHRAE Standard 41.6–2014 is
an industry-accepted test procedure for
measuring humidity and is referenced
by AHRI 1250–2020. Specifically, the
test procedure codified by this final rule
references ANSI/ASHRAE 41.6–2014 for
test provisions related to capacity
measurement of single-packaged
dedicated systems for the appendix C1
test procedure. ANSI/ASHRAE 41.6–
2014 is reasonably available on
ASHRAE’s website at www.ashrae.org.
ANSI/ASHRAE Standard 41.10–2013
is an industry-accepted test procedure
for measuring the mass flow of volatile
refrigerants with flowmeter test methods
and is referenced by AHRI 1250–2020.
Specifically, the test procedure codified
by this final rule references ANSI/
ASHRAE 41.10–2013 for measuring the
flow rates of volatile refrigerants with
flow meters for all refrigeration unit
tests. ANSI/ASHRAE 41.10–2013 is
reasonably available on ASHRAE’s
website at www.ashrae.org.
ASTM C518–17 is an industryaccepted test procedure for measuring
thermal transmission properties using a
heat flow meter apparatus. Specifically,
the test procedure codified by this final
rule references ASTM C518–17 for
testing walk-in envelope components.
ASTM C518–17 is reasonably available
on ASTM’s website at www.astm.org.
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ASTM C1199–14 is an industryaccepted test procedure for measuring
the steady state thermal transmittance of
fenestration systems and is referenced
by NFRC 102–2020. Specifically, the
test procedure codified by this final rule
references ASTM C1199–14 for testing
walk-in envelope components. ASTM
C1199–14 is reasonably available on
ASTM’s website at www.astm.org.
NFRC 102–2020 [E0A0], is an
industry-accepted test procedure for
measuring the steady state thermal
transmittance of fenestration systems.
Specifically, the test procedure codified
by this final rule references NFRC 102–
2020 for testing walk-in envelope
components. NFRC 102–2020 is
reasonably available on NFRC’s website
at www.nfrc.org.
V. Approval of the Office of the
Secretary
The Secretary of Energy has approved
publication of this final rule.
List of Subjects
10 CFR Part 429
Administrative practice and
procedure, Confidential business
information, Energy conservation,
Household appliances, Imports,
Intergovernmental relations, Reporting
and recordkeeping requirements, Small
businesses.
10 CFR Part 431
Administrative practice and
procedure, Confidential business
information, Energy conservation test
procedures, Incorporation by reference,
Reporting and recordkeeping
requirements.
Signing Authority
This document of the Department of
Energy was signed on April 12, 2023, by
Francisco Alejandro Moreno, Acting
Assistant Secretary for Energy Efficiency
and Renewable Energy, pursuant to
delegated authority from the Secretary
of Energy. That document with the
original signature and date is
maintained by DOE. For administrative
purposes only, and in compliance with
requirements of the Office of the Federal
Register, the undersigned DOE Federal
Register Liaison Officer has been
authorized to sign and submit the
document in electronic format for
publication, as an official document of
the Department of Energy. This
administrative process in no way alters
the legal effect of this document upon
publication in the Federal Register.
E:\FR\FM\04MYR2.SGM
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Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
1. The authority citation for part 429
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317; 28 U.S.C.
2461 note.
2. Amend § 429.53 by revising
paragraphs (a)(2)(i) and (a)(3) and
adding paragraph (a)(4) to read as
follows:
■
ddrumheller on DSK120RN23PROD with RULES2
§ 429.53 Walk-in coolers and walk-in
freezers.
(a) * * *
(2) * * *
(i) Applicable test procedure. If AWEF
or AWEF2 is determined by testing, test
according to the applicable provisions
of § 431.304(b) of this chapter with the
following equipment-specific
provisions.
(A) Dedicated condensing units.
Outdoor dedicated condensing
refrigeration systems that are also
designated for use in indoor
applications must be tested and rated as
both an outdoor dedicated condensing
refrigeration system and an indoor
dedicated refrigeration system.
(B) Matched refrigeration systems. A
matched refrigeration system is not
required to be rated if the constituent
unit cooler(s) and dedicated condensing
unit have been tested as specified in
§ 431.304(b)(4) of this chapter. However,
if a manufacturer wishes to represent
the efficiency of the matched
refrigeration system as distinct from the
efficiency of either constituent
component, or if the manufacturer
cannot rate one or both of the
constituent components using the
specified method, the manufacturer
must test and rate the matched
refrigeration system as specified in
§ 431.304(b)(4) of this chapter.
(C) Detachable single-packaged
dedicated systems. Detachable singlepackaged dedicated systems must be
tested and rated as a single-packaged
dedicated systems using the test
procedure in § 431.304(b)(4) of this
chapter.
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Equation 3 to Paragraph (a)(3)(ii)(A)
And x¯ is the sample mean, n is the
number of samples, and x¯i is the ith
sample; or,
(B) The upper 95 percent confidence
limit (UCL) of the true mean divided by
1.05, where:
Equation 4 to Paragraph (a)(3)(ii)(B)
And x¯ is the sample mean, s is the
sample standard deviation; n is the
number of samples, and t¥0.95 is the
statistic for a 95 percent one-tailed
confidence interval with n-1 degrees of
freedom (from appendix A to this
subpart).
(4) For each basic model of walk-in
cooler and walk-in freezer panel and
non-display door, the R-value must be
determined by testing, in accordance
with § 431.304 of this chapter and the
provisions of this section.
(i) Applicable test procedure. Prior to
October 31, 2023, use the test procedure
for walk-ins in 10 CFR part 431, subpart
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Equation 5 to Paragraph (a)(4)(ii)(A)
And x¯ is the sample mean, n is the
number of samples, and x¯i is the ith
sample; or,
(B) The lower 95 percent confidence
limit (LCL) of the true mean divided by
0.95, where:
Equation 6 to Paragraph (a)(4)(ii)(B)
And x¯ is the sample mean, s is the
sample standard deviation; n is the
number of samples, and t¥0.95 is the
statistic for a 95 percent one-tailed
confidence interval with n–1 degree of
freedom (from appendix A to this
subpart).
*
*
*
*
*
■ 3. Amend § 429.70 by:
■ a. Adding a heading for the table in
paragraph (c)(5)(viii)(A);
■ b. Renumbering tables 7 and 8 in
paragraphs (m)(5)(vi) and (m)(5)(viii)(A),
respectively, as tables 9 and 10;
■ c. Revising the heading to paragraph
(f) and paragraphs (f)(2)(ii)(A) and (B);
■ d. Adding paragraphs (f)(2)(ii)(C) and
(f)(2)(iii)(E);
■ e. Revising paragraphs (f)(2)(iv) and
(f)(5)(vi); and
■ f. Adding a heading for the table in
paragraph (h)(2)(iv).
The revisions and additions read as
follows:
§ 429.70 Alternative methods for
determining energy efficiency and energy
use.
*
*
*
(c) * * *
(5) * * *
(viii) * * *
(A) * * *
*
*
Table 3 to Paragraph (c)(5)(viii)(A)
*
*
*
*
*
(f) Alternative efficiency
determination method (AEDM) for walk-
E:\FR\FM\04MYR2.SGM
04MYR2
ER04MY23.003</GPH>
PART 429—CERTIFICATION,
COMPLIANCE, AND ENFORCEMENT
FOR CONSUMER PRODUCTS AND
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
R, appendix B, revised as of January 1,
2022, to determine R-value. Beginning
October 31, 2023, use the test procedure
in appendix B to subpart R of part 431
of this chapter to determine R-value.
(ii) Units to be tested. For each basic
model, a sample of sufficient size shall
be randomly selected and tested to
ensure that any represented value of Rvalue or other measure of efficiency of
a basic model for which consumers
would favor higher values shall be less
than or equal to the lower of:
(A) The mean of the sample, where:
ER04MY23.001</GPH> ER04MY23.002</GPH>
For the reasons stated in the
preamble, DOE is amending parts 429
and 431 of chapter II of title 10, Code
of Federal Regulations as set forth
below:
(D) Attached split systems. Attached
split systems must be tested and rated
as dedicated condensing units and unit
coolers using the test procedure in
§ 431.304(b)(4) of this chapter.
*
*
*
*
*
(3) For each basic model of walk-in
cooler and walk-in freezer display and
non-display door, the daily energy
consumption must be determined by
testing, in accordance with § 431.304 of
this chapter and the provisions of this
section, or by application of an AEDM
that meets the requirements of § 429.70
and the provisions of this section.
(i) Applicable test procedure. Prior to
October 31, 2023 use the test procedure
for walk-ins in 10 CFR part 431, subpart
R, appendix A, revised as of January 1,
2022, to determine daily energy
consumption. Beginning October 31,
2023, use the test procedure in part 431,
subpart R, appendix A of this chapter to
determine daily energy consumption.
(ii) Units to be tested. For each basic
model, a sample of sufficient size shall
be randomly selected and tested to
ensure that any represented value of
daily energy consumption of a basic
model or other measure of energy use
for which consumers would favor lower
values shall be greater than or equal to
the higher of:
(A) The mean of the sample, where:
ER04MY23.000</GPH>
Signed in Washington, DC, on April 12,
2023.
Treena V. Garrett,
Federal Register Liaison Officer, U.S.
Department of Energy.
28835
28836
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
in refrigeration systems and doors—
* * *
(2) * * *
(ii) * * *
(A) For refrigeration systems, which
are subject to an energy efficiency
metric, the predicted efficiency for each
model calculated by applying the AEDM
may not be more than five percent
greater than the efficiency determined
from the corresponding test of the
model.
(B) For doors, which are subject to an
energy consumption metric the
predicted daily energy consumption for
each model calculated by applying the
AEDM may not be more than five
percent less than the daily energy
consumption determined from the
corresponding test of the model.
(C) The predicted energy efficiency or
energy consumption for each model
calculated by applying the AEDM must
meet or exceed the applicable federal
energy conservation standard.
(iii) * * *
(E) For rating doors, an AEDM may
not simulate or model components of
the door that are not required to be
tested by the DOE test procedure. That
is, if the test results used to validate the
AEDM are for the U-factor test of the
door, the AEDM must estimate the daily
energy consumption, specifically the
conduction thermal load, and the direct
and indirect electrical energy
consumption, using the nominal values
and calculation procedure specified in
the DOE test procedure.
(iv) WICF validation classes—(A)
Doors.
TABLE 4 TO PARAGRAPH (f)(2)(iv)(A)
Minimum number of distinct models that must
be tested
Validation class
Display Doors, Medium Temperature .............................................................................................
Display Doors, Low Temperature ...................................................................................................
Non-display Doors, Medium Temperature ......................................................................................
Non-display Doors, Low Temperature ............................................................................................
(B) Refrigeration systems. (1) For
representations made prior to the
compliance date of revised energy
conservation standards for walk-in
cooler and walk-in freezer refrigeration
2
2
2
2
Basic
Basic
Basic
Basic
Models.
Models.
Models.
Models.
systems, use the following validation
classes.
TABLE 5 TO PARAGRAPH (f)(2)(iv)(B)(1)
Minimum number of distinct models that must
be tested
Validation class
Dedicated Condensing, Medium Temperature, Matched Pair Indoor System ...............................
Dedicated Condensing, Medium Temperature, Matched Pair Outdoor System 1 ..........................
Dedicated Condensing, Low Temperature, Matched Pair Indoor System .....................................
Dedicated Condensing, Low Temperature, Matched Pair Outdoor System 1 ................................
Unit Cooler, High-temperature ........................................................................................................
Unit Cooler, Medium Temperature ..................................................................................................
Unit Cooler, Low Temperature ........................................................................................................
Medium Temperature, Indoor Condensing Unit ..............................................................................
Medium Temperature, Outdoor Condensing Unit 1 .........................................................................
Low Temperature, Indoor Condensing Unit ....................................................................................
Low Temperature, Outdoor Condensing Unit 1 ...............................................................................
2
2
2
2
2
2
2
2
2
2
2
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
1 AEDMs validated for an outdoor class by testing only outdoor models of that class may be used to determine representative values for the
corresponding indoor class, and additional validation testing is not required. AEDMs validated only for a given indoor class by testing indoor
models or a mix of indoor and outdoor models may not be used to determine representative values for the corresponding outdoor class.
(2) For representations made on or
after the compliance date of revised
energy conservation standards for walkin cooler and walk-in freezer
refrigeration systems, use the following
validation classes.
TABLE 6 TO PARAGRAPH (f)(2)(iv)(B)(2)
Minimum number of distinct models that must
be tested
ddrumheller on DSK120RN23PROD with RULES2
Validation class
Dedicated Condensing Unit, Medium Temperature, Indoor System ..............................................
Dedicated Condensing Unit, Medium Temperature, Outdoor System 1 .........................................
Dedicated Condensing Unit, Low Temperature, Indoor System ....................................................
Dedicated Condensing Unit, Low Temperature, Outdoor System 1 ...............................................
Single-packaged Dedicated Condensing, High-temperature, Indoor System ................................
Single-packaged Dedicated Condensing, High-temperature, Outdoor System 1 ...........................
Single-packaged Dedicated Condensing, Medium Temperature, Indoor System ..........................
Single-packaged Dedicated Condensing, Medium Temperature, Outdoor System 1 .....................
Single-packaged Dedicated Condensing, Low Temperature, Indoor System ................................
Single-packaged Dedicated Condensing, Low Temperature, Indoor System 1 ..............................
Matched Pair, High-temperature, Indoor Condensing Unit .............................................................
Matched Pair, High-temperature, Outdoor Condensing Unit 1 ........................................................
Matched Pair, Medium Temperature, Indoor Condensing Unit ......................................................
Matched Pair, Medium Temperature, Outdoor Condensing Unit 1 .................................................
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2
2
2
2
2
2
2
2
2
2
2
2
2
2
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
E:\FR\FM\04MYR2.SGM
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
04MYR2
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
28837
TABLE 6 TO PARAGRAPH (f)(2)(iv)(B)(2)—Continued
Minimum number of distinct models that must
be tested
Validation class
Matched Pair, Low Temperature, Indoor Condensing Unit ............................................................
Matched Pair, Low Temperature, Outdoor Condensing Unit 1 .......................................................
Unit Cooler, High-temperature ........................................................................................................
Unit Cooler, Medium Temperature ..................................................................................................
Unit Cooler, Low Temperature ........................................................................................................
2
2
2
2
2
Basic
Basic
Basic
Basic
Basic
Models.
Models.
Models.
Models.
Models.
1 AEDMs validated for an outdoor class by testing only outdoor models of that class may be used to determine representative values for the
corresponding indoor class, and additional validation testing is not required. AEDMs validated only for a given indoor class by testing indoor
models or a mix of indoor and outdoor models may not be used to determine representative values for the corresponding outdoor class.
*
*
*
*
*
(5) * * *
(vi) Tolerances. For efficiency
metrics, the result from a DOE
verification test must be greater than or
equal to the certified rating × (1¥the
applicable tolerance). For energy
consumption metrics, the result from a
DOE verification test must be less than
or equal to the certified rating × (1 + the
applicable tolerance).
TABLE 7 TO PARAGRAPH (f)(5)(iv)
Equipment
Metric
Refrigeration systems (including components) ............................................................
Doors ............................................................................................................................
AWEF/AWEF2 ..........................................
Daily Energy Consumption .......................
*
*
*
(h) * * *
(2) * * *
(iv) * * *
*
*
Table 8 to Paragraph (h)(2)(iv)
*
*
*
*
*
■ 4. Amend § 429.110 by revising
paragraph (e)(2) to read as follows:
§ 429.110
Enforcement testing.
ddrumheller on DSK120RN23PROD with RULES2
*
*
*
*
*
(e) * * *
(2) For automatic commercial ice
makers; commercial refrigerators,
freezers, and refrigerator-freezers;
refrigerated bottled or canned vending
machines; commercial air conditioners
and heat pumps; commercial packaged
boilers; commercial warm air furnaces;
commercial water heating equipment;
and walk-in cooler and walk-in freezer
doors, panels, and refrigeration systems,
DOE will use an initial sample size of
not more than four units and follow the
sampling plans in appendix B to this
subpart.
*
*
*
*
*
■ 5. Amend § 429.134 by adding
introductory text to paragraph (q) and
revising paragraphs (q)(2) and (4) to read
as follows:
§ 429.134 Product-specific enforcement
provisions.
*
*
*
*
*
(q) * * * Prior to October 31, 2023,
the provisions in 10 CFR 429.134,
revised as of January 1, 2022, are
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20:49 May 03, 2023
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applicable. On and after October 31,
2023, the following provisions apply.
*
*
*
*
*
(2) Verification of refrigeration system
net capacity. The net capacity of the
refrigeration system basic model will be
measured pursuant to the test
requirements of part 431, subpart R,
appendix C of this chapter for each unit
tested on and after October 31, 2023, but
before the compliance date of revised
energy conservation standards for walkin cooler and walk-in freezer
refrigeration systems. The net capacity
of the refrigeration system basic model
will be measured pursuant to the test
requirements of part 431, subpart R,
appendix C1 of this chapter for each
unit tested on and after the compliance
date of revised energy conservation
standards for walk-in cooler and walkin freezer refrigeration systems. The
results of the measurement(s) will be
averaged and compared to the value of
net capacity certified by the
manufacturer. The certified net capacity
will be considered valid only if the
average measured net capacity is within
plus or minus five percent of the
certified net capacity.
*
*
*
*
*
(4) Verification of door electricityconsuming device power. For each basic
model of walk-in cooler and walk-in
freezer door, DOE will calculate the
door’s energy consumption using the
input power listed on the nameplate of
each electricity-consuming device
shipped with the door. If an electricityconsuming device shipped with a walk-
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Applicable
tolerance
(%)
5
5
in door does not have a nameplate or
the nameplate does not list the device’s
input power, then DOE will use the
device’s rated input power included in
the door’s certification report. If the
door is not certified or if the
certification does not include a rated
input power for an electricityconsuming device shipped with a walkin door, DOE will use the measured
input power. DOE also may validate the
power listed on the nameplate or the
rated input power by measuring it when
energized using a power supply that
provides power within the allowable
voltage range listed on the component
nameplate or the door nameplate,
whichever is available. If the measured
input power is more than 10 percent
higher than the input power listed on
the nameplate or the rated input power,
as appropriate, then the measured input
power shall be used in the door’s energy
consumption calculation.
(i) For electricity-consuming devices
with controls, the maximum input
wattage observed while energizing the
device and activating the control shall
be considered the measured input
power. For anti-sweat heaters that are
controlled based on humidity levels, the
control may be activated by increasing
relative humidity in the region of the
controls without damaging the sensor.
For lighting fixtures that are controlled
with motion sensors, the control may be
activated by simulating motion in the
vicinity of the sensor. Other kinds of
controls may be activated based on the
functions of their sensor.
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28838
*
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
(ii) [Reserved]
*
*
*
*
PART 431—ENERGY EFFICIENCY
PROGRAM FOR CERTAIN
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
6. The authority citation for part 431
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317; 28 U.S.C.
2461 note.
7. Amend § 431.302 by:
a. Adding, in alphabetical order,
definitions for ‘‘Attached split system,’’
‘‘CO2 unit cooler,’’ and ‘‘Detachable
single-packaged dedicated system’’;
■ b. Revising the definition for ‘‘Door’’;
■ c. Adding, in alphabetical order,
definitions for ‘‘Door leaf,’’ ‘‘Door
surface area,’’ ‘‘Ducted fan coil unit,’’
‘‘Ducted multi-circuit single-packaged
dedicated system,’’ ‘‘Ducted singlepackaged dedicated system,’’ ‘‘Hightemperature refrigeration system,’’
‘‘Multi-circuit single-packaged
dedicated system,’’ and ‘‘Non-display
door’’; and
■ d. Revising the definition of ‘‘Walk-in
cooler and walk-in freezer’’.
The additions and revisions read as
follows:
■
■
§ 431.302 Definitions concerning walk-in
coolers and walk-in freezers.
*
*
*
*
*
Attached split system means a
matched pair refrigeration system which
is designed to be installed with the
evaporator entirely inside the walk-in
enclosure and the condenser entirely
outside the walk-in enclosure, and the
evaporator and condenser are
permanently connected with structural
members extending through the walk-in
wall.
*
*
*
*
*
CO2 unit cooler means a unit cooler
that includes a nameplate listing only
CO2 as an approved refrigerant.
*
*
*
*
*
ddrumheller on DSK120RN23PROD with RULES2
*
*
*
*
*
Detachable single-packaged dedicated
system means a system consisting of a
dedicated condensing unit and an
insulated evaporator section in which
the evaporator section is designed to be
installed external to the walk-in
enclosure and circulating air through
the enclosure wall, and the condensing
unit is designed to be installed either
attached to the evaporator section or
mounted remotely with a set of
refrigerant lines connecting the two
components.
*
*
*
*
*
Door means an assembly installed in
an opening on an interior or exterior
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Jkt 259001
wall that is used to allow access or close
off the opening and that is movable in
a sliding, pivoting, hinged, or revolving
manner of movement. For walk-in
coolers and walk-in freezers, a door
includes the frame (including mullions),
the door leaf or multiple leaves
(including glass) within the frame, and
any other elements that form the
assembly or part of its connection to the
wall.
Door leaf means the pivoting, rolling,
sliding, or swinging portion of a door.
Door surface area means the product
of the height and width of a walk-in
door measured external to the walk-in.
The height and width dimensions shall
be perpendicular to each other and
parallel to the wall or panel of the walkin to which the door is affixed. The
height and width measurements shall
extend to the edge of the frame and
frame flange (as applicable) to which the
door is affixed. For sliding doors, the
height and width measurements shall
include the track; however, the width
(for horizontal sliding doors) or the
height (for vertical sliding doors) shall
be truncated to the external width or
height of the door leaf or leaves and its
frame or casings. The surface area of a
display door is represented as Add and
the surface area of a non-display door is
represented as And.
Ducted fan coil unit means an
assembly, including means for forced air
circulation capable of moving air against
both internal and non-zero external flow
resistance, and elements by which heat
is transferred from air to refrigerant to
cool the air, with provision for ducted
installation.
Ducted multi-circuit single-packaged
dedicated system means a ducted
single-packaged dedicated system or a
ducted single-packaged dedicated
system (as defined in this section) that
contains two or more refrigeration
circuits that refrigerate a single stream
of circulated air.
Ducted single-packaged dedicated
system means a refrigeration system (as
defined in this section) that is a singlepackaged assembly designed for use
with ducts, that includes one or more
compressors, a condenser, a means for
forced circulation of refrigerated air, and
elements by which heat is transferred
from air to refrigerant.
*
*
*
*
*
High-temperature refrigeration system
means a refrigeration system which is
not designed to operate below 45 °F.
*
*
*
*
*
Multi-circuit single-packaged
dedicated system means a singlepackaged dedicated system or a ducted
single-packaged dedicated system (as
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defined in this section) that contains
two or more refrigeration circuits that
refrigerate a single stream of circulated
air.
Non-display door means a door that is
not a display door.
*
*
*
*
*
Walk-in cooler and walk-in freezer
means an enclosed storage space
including, but not limited to, panels,
doors, and refrigeration system,
refrigerated to temperatures,
respectively, above, and at or below 32
degrees Fahrenheit that can be walked
into, and has a total chilled storage area
of less than 3,000 square feet; however,
the terms do not include products
designed and marketed exclusively for
medical, scientific, or research
purposes.
*
*
*
*
*
■ 8. Revise § 431.303 as follows:
§ 431.303 Materials incorporated by
reference.
(a) Certain material is incorporated by
reference into this subpart with the
approval of the Director of the Federal
Register in accordance with 5 U.S.C.
552(a) and 1 CFR part 51. To enforce
any edition other than that specified in
this section, the U.S. Department of
Energy (DOE) must publish a document
in the Federal Register and the material
must be available to the public. All
approved incorporation by reference
(IBR) material is available for inspection
at DOE, and at the National Archives
and Records Administration (NARA).
Contact DOE at: the U.S. Department of
Energy, Office of Energy Efficiency and
Renewable Energy, Building
Technologies Program, Sixth Floor, 950
L’Enfant Plaza SW, Washington, DC
20024, (202) 586–9127, Buildings@
ee.doe.gov, www.energy.gov/eere/
buildings/building-technologies-office.
For information on the availability of
this material at NARA, email:
fr.inspection@nara.gov, or go to:
www.archives.gov/federal-register/cfr/
ibr-locations.html. The material may be
obtained from the sources in the
following paragraphs of this section.
(b) AHRI. Air-Conditioning, Heating,
and Refrigeration Institute, 2111 Wilson
Boulevard, Suite 500, Arlington, VA
22201; (703) 600–0366;
www.ahrinet.org.
(1) ANSI/AHRI Standard 420–2008
(‘‘AHRI 420–2008’’), Performance
Rating of Forced-Circulation FreeDelivery Unit Coolers for Refrigeration,
Copyright 2008; IBR approved for
appendix C to subpart R.
(2) AHRI Standard 1250P (I–P)–2009
(‘‘AHRI 1250–2009’’), Standard for
Performance Rating of Walk-in Coolers
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Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
and Freezers, (including Errata sheet
dated December 2015), copyright 2009,
except Table 15 and Table 16; IBR
approved for appendix C to subpart R.
(3) AHRI Standard 1250 (‘‘AHRI
1250–2020’’), Standard for Performance
Rating of Walk-in Coolers and Freezers,
copyright 2020; IBR approved for
appendix C1 to subpart R.
(c) ASHRAE. American Society of
Heating, Refrigerating and AirConditioning Engineers, 180
Technology Parkway, Peachtree
Corners, GA 30092; (404) 636–8400;
www.ashrae.org.
(1) ANSI/ASHRAE Standard 16–2016
(‘‘ANSI/ASHRAE 16’’), Method of
Testing for Rating Room Air
Conditioners, Packaged Terminal Air
Conditioners, and Packaged Terminal
Heat Pumps for Cooling and Heating
Capacity, ANSI-approved November 1,
2016; IBR approved for appendix C1 to
subpart R.
(2) ANSI/ASHRAE Standard 23.1–
2010 (‘‘ASHRAE 23.1–2010’’), Methods
of Testing for Rating the Performance of
Positive Displacement Refrigerant
Compressors and Condensing Units that
Operate at Subcritical Temperatures of
the Refrigerant, ANSI-approved January
28, 2010; IBR approved for appendices
C and C1 to subpart R.
(3) ANSI/ASHRAE Standard 37–2009
(‘‘ANSI/ASHRAE 37’’), Methods of
Testing for Rating Electrically Driven
Unitary Air-Conditioning and Heat
Pump Equipment, ASHRAE-approved
June 24, 2009; IBR approved for
appendices C and C1 to subpart R.
(4) ANSI/ASHRAE Standard 41.1–
2013 (‘‘ANSI/ASHRAE 41.1’’), Standard
Method for Temperature Measurement,
ANSI-approved January 30, 2013; IBR
approved for appendix C1 to subpart R.
(5) ANSI/ASHRAE Standard 41.3–
2014 (‘‘ANSI/ASHRAE 41.3’’), Standard
Methods for Pressure Measurement,
ANSI-approved July 3, 2014; IBR
approved for appendix C1 to subpart R.
(6) ANSI/ASHRAE Standard 41.6–
2014 (‘‘ANSI/ASHRAE 41.6’’), Standard
Method for Humidity Measurement,
ANSI-approved July 3, 2014; IBR
approved for appendix C1 to subpart R.
(7) ANSI/ASHRAE Standard 41.10–
2013 (‘‘ANSI/ASHRAE 41.10’’),
Standard Methods for Refrigerant Mass
Flow Measurement Using Flowmeters,
ANSI-approved June 27, 2013; IBR
approved for appendix C1 to subpart R.
(d) ASTM. ASTM, International, 100
Barr Harbor Drive, West Conshohocken,
PA 19428–2959; (610) 832–9500;
www.astm.org.
(1) ASTM C518–17, Standard Test
Method for Steady-State Thermal
Transmission Properties by Means of the
Heat Flow Meter Apparatus, approved
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May 1, 2017; IBR approved for appendix
B to subpart R.
(2) ASTM C1199–14, Standard Test
Method for Measuring the Steady-State
Thermal Transmittance of Fenestration
Systems Using Hot Box Methods,
approved February 1, 2014; IBR
approved for appendix A to subpart R.
(e) NFRC. National Fenestration
Rating Council, 6305 Ivy Lane, Ste. 140,
Greenbelt, MD 20770; (301) 589–1776;
www.nfrc.org/.
(1) NFRC 102–2020 [E0A0] (‘‘NFRC
102–2020’’), Procedure for Measuring
the Steady-State Thermal
Transmittance of Fenestration Systems,
copyright 2013; IBR approved for
appendix A to subpart R.
(2) [Reserved]
■ 9. Amend § 431.304 by revising
paragraph (b) to read as follows:
§ 431.304 Uniform test method for the
measurement of energy consumption of
walk-in coolers and walk-in freezers.
*
*
*
*
*
(b) Testing and calculations.
Determine the energy efficiency and/or
energy consumption of the specified
walk-in cooler and walk-in freezer
components by conducting the
appropriate test procedure as follows:
(1) Display panels. Determine the
energy use of walk-in cooler and walkin freezer display panels by conducting
the test procedure set forth in appendix
A to this subpart.
(2) Display doors and non-display
doors. Determine the energy use of
walk-in cooler and walk-in freezer
display doors and non-display doors by
conducting the test procedure set forth
in appendix A to this subpart.
(3) Non-display panels and nondisplay doors. Determine the R-value of
insulation of walk-in cooler and walk-in
freezer non-display panels and nondisplay doors by conducting the test
procedure set forth in appendix B to this
subpart.
(4) Refrigeration systems. Determine
the AWEF and net capacity of walk-in
cooler and walk-in freezer refrigeration
systems by conducting the test
procedures set forth in appendix C or C1
to this subpart, as applicable. Refer to
the notes at the beginning of those
appendices to determine the applicable
appendix to use for testing.
(i) For unit coolers: follow the general
testing provisions in sections 3.1 and
3.2, and the equipment-specific
provisions in section 3.3 of appendix C
or sections 4.5 through 4.8 of appendix
C1.
(ii) For dedicated condensing units:
follow the general testing provisions in
sections 3.1 and 3.2, and the productspecific provisions in section 3.4 of
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appendix C or sections 4.5 through 4.8
of appendix C1.
(iii) For single-packaged dedicated
systems: follow the general testing
provisions in sections 3.1 and 3.2, and
the product-specific provisions in
section 3.3 of appendix C or sections 4.5
through 4.8 of appendix C1.
■ 10. Revise appendix A to subpart R of
part 431 to read as follows:
Appendix A to Subpart R of Part 431—
Uniform Test Method for the
Measurement of Energy Consumption of
the Components of Envelopes of WalkIn Coolers and Walk-In Freezers
Note: Prior to October 31, 2023,
representations with respect to the energy
use of envelope components of walk-in
coolers and walk-in freezers, including
compliance certifications, must be based on
testing conducted in accordance with the
applicable provisions of 10 CFR part 431,
subpart R, appendix A, revised as of January
1, 2022. Beginning October 31, 2023,
representations with respect to energy use of
envelope components of walk-in coolers and
walk-in freezers, including compliance
certifications, must be based on testing
conducted in accordance with this appendix.
0. Incorporation by Reference
DOE incorporated by reference in § 431.303
the entire standard for ASTM C1199–14 and
NFRC 102–2020. However, certain
enumerated provisions of these standards, as
set forth in sections 0.1 and 0.2 of this
appendix are inapplicable. To the extent that
there is a conflict between the terms or
provisions of a referenced industry standard
and the CFR, the CFR provisions control.
0.1 ASTM C1199–14
(a) Section 1 Scope, is inapplicable,
(b) Section 4 Significance and Use is
inapplicable,
(c) Section 7.3 Test Conditions, is
inapplicable,
(d) Section 10 Report, is inapplicable,
and
(e) Section 11 Precision and Bias, is
inapplicable.
0.2 NFRC 102–2020
(a) Section 1 Scope, is inapplicable,
(b) Section 4 Significance and Use, is
inapplicable,
(c) Section 7.3 Test Conditions, is
inapplicable,
(d) Section 10 Report, is inapplicable,
(e) Section 11 Precision and Bias, is
inapplicable,
(f) Annex A3 Standard Test Method for
Determining the Thermal Transmittance of
Tubular Daylighting Devices, is inapplicable,
and
(g) Annex A5 Tables and Figures, is
inapplicable.
1. General. The following sections of this
appendix provide additional instructions for
testing. In cases where there is a conflict, the
language of this appendix takes highest
precedence, followed by NFRC 102–2020,
followed by ASTM C1199–14. Any
subsequent amendment to a referenced
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3. Definitions
The definitions contained in § 431.302 are
applicable to this appendix.
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4. Additional Definitions
4.1 Automatic door opener/closer means
a device or control system that
‘‘automatically’’ opens and closes doors
without direct user contact, such as a motion
sensor that senses when a forklift is
approaching the entrance to a door and opens
it, and then closes the door after the forklift
has passed.
4.2 Percent time off (PTO) means the
percent of time that an electrical device is
assumed to be off.4.3 Rated power means the
input power of an electricity-consuming
TABLE A.1—TEMPERATURE
CONDITIONS
Internal Temperatures (cooled space within
the envelope)
Cooler Dry-Bulb Temperature ..
Freezer Dry-Bulb Temperature
35 °F
¥10 °F
External Temperatures (space external to
the envelope)
Freezer and Cooler Dry-Bulb
Temperatures ........................
75 °F
5. Test Methods and Measurements
5.1 U-Factor Test of Doors and Display
Panels
Determine the U-factor of the entire door
or display panel, including the frame, in
accordance with the specified sections of
NFRC 102–2020 and ASTM C1199–14 at the
temperature conditions listed in table A.1 of
this appendix.
5.2 Required Test Measurements
2.1 For display doors and display panels,
thermal transmittance, Udd or Udp,
respectively, shall be the standardized
thermal transmittance, UST, determined per
section 5.1.1 of this appendix.
5.2.2 For non-display doors, thermal
transmittance, Und, shall be the standardized
thermal transmittance, UST, determined per
section 5.1 of this appendix.
5.2.3 Projected area of the test specimen,
As, in ft2, as referenced in ASTM C1199–14.
6. Calculations
6.1 Display Panels
6.1.1 Determine the U-factor of the
display panel in accordance with section 5.1
of this appendix, in units of Btu/(h-ft2-°F).
6.1.2 Calculate the temperature
differential, DTdp, °F, for the display panel, as
follows:
Where:
TDB,ext,dp = dry-bulb air external temperature,
°F, as prescribed in table A.1 of this
appendix; and
TDB,int,dp = dry-bulb air temperature internal
to the cooler or freezer, °F, as prescribed
in table A.1 of this appendix.
6.1.3 Calculate the conduction load
through the display panel, Qcond-dp, Btu/h, as
follows:
Where:
As = projected area of the test specimen
(same as the test specimen aperture in
the surround panel) or the area used to
determine the U-factor in section 5.1 of
this appendix, ft2;
DTdp = temperature differential between
refrigerated and adjacent zones, °F; and
Udp = thermal transmittance, U-factor, of the
display panel in accordance with section
5.1 of this appendix, Btu/(h-ft2-°F).
6.1.4 Calculate the total daily energy
consumption, Edp, kWh/day, as follows:
Where:
Qcond,dp = the conduction load through the
display panel, Btu/h; and
EER = Energy Efficiency Ratio of walk-in
(cooler or freezer), Btu/W-h. For coolers,
use EER = 12.4 Btu/W-h. For freezers,
use EER = 6.3 Btu/W-h.
6.2
6.2.1.2 Calculate the temperature
differential, DTdd, °F, for the display door as
follows:
Where:
TDB,ext,dd = dry-bulb air temperature external
to the display door, °F, as prescribed in
table A.1 of this appendix; and
TDB,int,dd = dry-bulb air temperature internal
to the display door, °F, as prescribed in
table A.1 of this appendix.
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6.2.1
Display Doors
Conduction Through Display Doors
6.2.1.1 Determine the U-factor of the
display door in accordance with section 5.1
of this appendix, in units of Btu/(h-ft2-°F).
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6.2.1.3 Calculate the conduction load
through the display doors, Qcond,dd, Btu/h, as
follows:
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2. Scope
This appendix covers the test requirements
used to measure the energy consumption of
the components that make up the envelope
of a walk-in cooler or walk-in freezer.
device as specified on the device’s
nameplate. If the device does not have a
nameplate or such nameplate does not list
the device’s input power, then the rated
power must be determined from the device’s
product data sheet, literature, or installation
instructions that come with the device or are
available online.
4.4 Rating conditions means, unless
explicitly stated otherwise, all conditions
shown in table A.1 of this appendix.
ER04MY23.005</GPH> ER04MY23.006</GPH>
document by the standard-setting
organization will not affect the test procedure
in this appendix, unless and until the test
procedure is amended by DOE. Material is
incorporated as it exists on the date of the
approval, and a notification of any change in
the incorporation will be published in the
Federal Register.
ER04MY23.004</GPH>
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Where:
As = projected area of the test specimen
(same as the test specimen aperture in
the surround panel) or the area used to
determine the U-factor in section 5.1 of
this appendix, ft2;
Where:
Qcond,dd = the conduction load through the
display door, Btu/h; and
EER = EER of walk-in (cooler or freezer), Btu/
W-h. For coolers, use EER = 12.4 Btu/(W-
DTdd = temperature differential between
refrigerated and adjacent zones, °F; and
Udd = thermal transmittance, U-factor of the
door, in accordance with section 5.1 of
this appendix, Btu/(h-ft2-°F).
h). For freezers, use EER = 6.3 Btu/(Wh).
6.2.2 Direct Energy Consumption of
Electrical Component(s) of Display Doors
Electrical components associated with
display doors could include but are not
28841
6.2.1.4 Calculate the total daily energy
consumption due to conduction thermal
load, Edd,thermal, kWh/day, as follows:
limited to: heater wire (for anti-sweat or antifreeze application); lights; door motors;
control system units; and sensors.
6.2.2.1 Select the required value for
percent time off (PTO) for each type of
electricity-consuming device per table A.2 of
this appendix, PTOt (%).
TABLE A.2—PERCENT TIME OFF VALUES
Device
Temperature
condition
Controls, timer, or
other auto-shut-off
system
Lights .........................................................................................................................
All ............................
Anti-sweat heaters .....................................................................................................
All ............................
Coolers ...................
Freezers .................
All ............................
All ............................
Without ...................
With ........................
Without ...................
With ........................
With ........................
.................................
Without ...................
With ........................
Door motors ...............................................................................................................
All other electricity-consuming devices .....................................................................
Percent time
off value
(%)
25
50
0
75
50
97
0
25
Pdd,comp,int,t = the energy usage for an
electricity-consuming device sited on the
interior facing side of or in the display
door, of type t, kWh/day; and
Pdd,comp,ext,t = the energy usage for an
electricity-consuming device sited on the
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external facing side of the display door,
of type t, kWh/day. 6.2.2.4 Calculate the
total electrical energy consumption,
Pdd,tot, (kWh/day), as follows:
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ER04MY23.012</GPH>
Where:
t = index for each type of electricityconsuming device with identical rated
input power;
Prated,u,t = rated input power of each
component, of type t, kW;
PTOu,t = percent time off, for device of type
t, %; and
nu,t = number of devices at the rated input
power of type t, unitless. 6.2.2.3
Calculate the total electrical energy
consumption for interior and exterior
power, Pdd,tot,int (kWh/day) and Pdd,tot,ext
(kWh/day), respectively, as follows:
ER04MY23.011</GPH>
index is represented by u = ext. If the
electrical component is both on the
interior and exterior side of the display
door then use u = int. For anti-sweat
heaters sited anywhere in the display
door, 75 percent of the total power is be
attributed to u = int and 25 percent of the
total power is attributed to u = ext;
t = index for each type of electricityconsuming device with identical rated
power;
ER04MY23.009</GPH> ER04MY23.010</GPH>
Where:
u = the index for each of type of electricityconsuming device located on either (1)
the interior facing side of the display
door or within the inside portion of the
display door, (2) the exterior facing side
of the display door, or (3) any
combination of (1) and (2). For purposes
of this calculation, the interior index is
represented by u = int and the exterior
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6.2.2.2 Calculate the power usage for each
type of electricity-consuming device,
Pdd,comp,u,t, kWh/day, as follows:
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Where:
Pdd,tot,int = the total interior electrical energy
usage for the display door, kWh/day; and
Pdd,tot,ext = the total exterior electrical energy
usage for the display door, kWh/day.
6.2.3 Total Indirect Electricity Consumption
Due to Electrical Devices
from electrical components sited inside the
display door, Cdd,load, kWh/day, as follows:
Where:
Pdd,tot,int = The total internal electrical energy
consumption due for the display door,
kWh/day; and
EER = EER of walk-in cooler or walk-in
freezer, Btu/W-h. For coolers, use EER =
12.4 Btu/(W-h). For freezers, use EER =
6.3 Btu/(W-h).
6.2.4 Total Display Door Energy
Consumption
Where:
Edd,thermal = the total daily energy
consumption due to thermal load for the
display door, kWh/day;
Pdd,tot = the total electrical load, kWh/day;
and
Cdd,load = additional refrigeration load due to
thermal output from electrical
components contained within the
display door, kWh/day.
6.3 Non-Display Doors
6.3.1.2 Calculate the temperature
differential of the non-display door, DTnd, °F,
as follows:
Where:
TDB,ext,nd = dry-bulb air external temperature,
°F, as prescribed by table A.1 of this
appendix; and
TDB,int,nd = dry-bulb air internal temperature,
°F, as prescribed by table A.1 of this
appendix. If the component spans both
cooler and freezer spaces, the freezer
temperature must be used.
6.3.1.3 Calculate the conduction load
through the non-display door: Qcond,nd, Btu/h,
Where:
As = projected area of the test specimen
(same as the test specimen aperture in
the surround panel) or the area used to
determine the U-factor in section 5.1 of
this appendix, ft2;
DTnd = temperature differential across the
non-display door, °F; and
Und = thermal transmittance, U-factor of the
door, in accordance with section 5.1 of
this appendix, Btu/(h-ft2-°F).
6.3.1.4 Calculate the total daily energy
consumption due to thermal load, End,thermal,
kWh/day, as follows:
Where:
Qcond,nd = the conduction load through the
non-display door, Btu/h; and
EER = EER of walk-in (cooler or freezer), Btu/
W-h. For coolers, use EER = 12.4 Btu/(Wh). For freezers, use EER = 6.3 Btu/(Wh).
6.3.2 Direct Energy Consumption of
Electrical Components of Non-Display Doors
Electrical components associated with nondisplay doors comprise could include, but
are not limited to: heater wire (for anti-sweat
or anti-freeze application), lights, door
motors, control system units, and sensors.
6.3.2.1 Select the required value for
percent time off for each type of electricityconsuming device per table A.2 of this
appendix, PTOt (%).
6.3.2.2 Calculate the power usage for each
type of electricity-consuming device,
Pnd,comp,u,t, kWh/day, as follows:
Calculate the additional refrigeration
energy consumption due to thermal output
Calculate the total energy, Edd,tot, kWh/day,
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ER04MY23.016</GPH>
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6.3.1 Conduction Through Non-Display
Doors
6.3.1.1 Determine the U-factor of the nondisplay door in accordance with section 5.1
of this appendix, in units of Btu/(h-ft2-°F).
28843
Where:
u = the index for each of type of electricityconsuming device located on either (1)
the interior facing side of the nondisplay door or within the inside portion
of the non-display door, (2) the exterior
facing side of the non-display door, or (3)
any combination of (1) and (2). For
purposes of this calculation, the interior
index is represented by u = int and the
exterior index is represented by u = ext.
If the electrical component is both on the
interior and exterior side of the nondisplay door then use u = int. For antisweat heaters sited anywhere in the nondisplay door, 75 percent of the total
power is be attributed to u = int and 25
percent of the total power is attributed to
u = ext;
t = index for each type of electricityconsuming device with identical rated
input power;
Prated,u,t = rated input power of each
component, of type t, kW;
PTOu,t = percent time off, for device of type
t, %; and
nu,t = number of devices at the rated input
power of type t, unitless.
6.3.2.3 Calculate the total electrical
energy consumption for interior and exterior
power, Pnd,tot,int, kWh/day, and Pnd,tot,ext, kWh/
day, respectively, as follows:
Where:
t = index for each type of electricityconsuming device with identical rated
input power;
Pnd,comp,int,t = the energy usage for an
electricity-consuming device sited on the
internal facing side or internal to the
non-display door, of type t, kWh/day;
and
Pnd,comp,ext,t = the energy usage for an
electricity-consuming device sited on the
external facing side of the non-display
door, of type t, kWh/day. For anti-sweat
heaters,
6.3.2.4 Calculate the total electrical
energy consumption, Pnd,tot, kWh/day, as
follows:
Where:
Pnd,tot,int = the total interior electrical energy
usage for the non-display door, of type
t, kWh/day; and
Pnd,tot,ext = the total exterior electrical energy
usage for the non-display door, of type
t, kWh/day.
6.3.3 Total Indirect Electricity Consumption
Due to Electrical Devices
the non-display door, Cnd,load, kWh/day, as
follows:
Where:
Pnd,tot,int = the total interior electrical energy
consumption for the non-display door,
kWh/day; and
EER = EER of walk-in cooler or freezer, Btu/
W-h. For coolers, use EER = 12.4 Btu/(Wh). For freezers, use EER = 6.3 Btu/(Wh).
6.3.4 Total Non-Display Door Energy
Consumption
Calculate the total energy, End,tot, kWh/day,
as follows:
Where:
End,thermal = the total daily energy
consumption due to thermal load for the
non-display door, kWh/day;
Pnd,tot = the total electrical energy
consumption, kWh/day; and
Cnd,load = additional refrigeration load due to
thermal output from electrical
components contained on the inside face
of the non-display door, kWh/day.
Appendix B to Subpart R of Part 431—
Uniform Test Method for the
Measurement of R-Value of Insulation
for Envelope Components of Walk-In
Coolers and Walk-In Freezers
0. Incorporation by Reference
DOE incorporated by reference in § 431.303
the entire standard for ASTM C518–17.
However, certain enumerated provisions of
ASTM C518–17, as set forth in paragraph 0.1
of this appendix, are inapplicable. To the
extent there is a conflict between the terms
or provisions of a referenced industry
standard and the CFR, the CFR provisions
control.
0.1 ASTM C518–17
(a) Section 1 Scope, is inapplicable,
(b) Section 4 Significance and Use, is
inapplicable,
(c) Section 7.3 Specimen Conditioning, is
inapplicable,
(d) Section 9 Report, is inapplicable,
(e) Section 10 Precision and Bias, is
inapplicable,
(f) Section 11 Keywords, is inapplicable,
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ER04MY23.024</GPH>
ER04MY23.023</GPH>
Note: Prior to October 31, 2023,
representations with respect to the R-value
for insulation of envelope components of
walk-in coolers and walk-in freezers,
including compliance certifications, must be
based on testing conducted in accordance
with the applicable provisions of 10 CFR part
431, subpart R, appendix B, revised as of
January 1, 2022. Beginning October 31, 2023,
representations with respect to R-value for
insulation of envelope components of walkin coolers and walk-in freezers, including
compliance certifications, must be based on
testing conducted in accordance with this
appendix.
ER04MY23.021</GPH> ER04MY23.022</GPH>
11. Revise appendix B to subpart R of
part 431 to read as follows:
■
Calculate the additional refrigeration
energy consumption due to thermal output
from electrical components associated with
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1. General
The following sections of this appendix
provide additional instructions for testing. In
cases where there is a conflict, the language
of this appendix takes highest precedence,
followed by ASTM C518–17. Any subsequent
amendment to a referenced document by the
standard-setting organization will not affect
the test procedure in this appendix, unless
and until the test procedure is amended by
DOE. Material is incorporated as it exists on
the date of the approval, and a notification
of any change in the incorporation will be
published in the Federal Register.
3. Definitions
The definitions contained in § 431.302
apply to this appendix.
4. Additional Definitions
4.1 Edge region means a region of the
envelope component that is wide enough to
encompass any framing members. If the
envelope component contains framing
members (e.g., a wood frame) then the width
of the edge region must be as wide as any
framing member plus an additional 2 in. ±
0.25 in.
materials during testing in accordance with
ASTM C518–17. When preparing the
specimen for test, a high-speed bandsaw or
a meat slicer are two types of recommended
cutting tools. Hot wire cutters or other heated
tools shall not be used for cutting foam test
specimens.
5.2
Specimen Preparation
2. Scope
This appendix covers the test requirements
used to measure the R-value of non-display
panels and non-display doors of a walk-in
cooler or walk-in freezer.
5. Test Methods, Measurements, and
Calculations
5.1 General. Foam shall be tested after it
is produced in its final chemical form. For
foam produced inside of an envelope
component (‘‘foam-in-place’’), ‘‘final
chemical form’’ means the foam is cured as
intended and ready for use as a finished
envelope component. For foam produced as
board stock (e.g., polystyrene), ‘‘final
chemical form’’ means after extrusion and
ready for assembly into an envelope
component or after assembly into an
envelope component. Foam must not include
any structural members or non-foam
5.2.1 Determining the thickness around
the perimeter of the envelope component, tp.
The full thickness of an envelope component
around the perimeter, which may include
facers on one or both sides, shall be
determined as follows:
5.2.1.1 At least 8 thickness measurements
shall be taken around the perimeter of the
envelope component, at least 2 inches from
the edge region, and avoiding any regions
with hardware or fixtures.
5.2.1.2 The average of the thickness
measurements taken around the perimeter of
the envelope component shall be the
thickness around the perimeter of the
envelope component, tp.
5.2.1.3 Measure and record the width, wp,
and height, hp, of the envelope component.
The surface area of the envelope component,
Ap, shall be determined as follows:
Where:
wp = width of the envelope component, in.;
and
hp = height of the envelope component, in.
5.2.2. Removing the sample from the
envelope component.
5.2.2.1. Determine the center of the
envelope component relative to its height
and its width.
5.2.2.2. Cut a sample from the envelope
component that is at least the length and
width dimensions of the heat flow meter, and
where the marked center of the sample is at
least 3 inches from any cut edge.
5.2.2.3. If the center of the envelope
component contains any non-foam
components (excluding facers), additional
samples may be cut adjacent to the previous
cut that is at least the length and width
dimensions of the heat flow meter and is
greater than 12 inches from the edge region.
5.2.3. Determining the thickness at the
center of the envelope component, tc. The full
thickness of an envelope component at the
center, which may include facers on one or
both sides, shall be determined as follows:
5.2.3.1. At least 2 thickness measurements
shall be taken in each quadrant of the cut
sample removed from the envelope
component per section 5.2.2 of this
appendix, for a total of at least 8
measurements.
5.2.3.2. The average of the thickness
measurements of the cut sample removed
from the envelope component shall be the
overall thickness of the cut sample, tc.
5.2.3.3. Measure and record the width and
height of the cut sample removed from the
envelope component. The surface area of the
cut sample removed from the envelope
component, Ac., shall be determined as
follows:
Where:
wc = width of the cut sample removed from
the envelope component, in.; and
hc = height of the cut sample removed from
the envelope component, in.
5.2.4. Determining the total thickness of
the foam within the envelope component,
tfoam. The average total thickness of the foam
sample, without facers, shall be determined
as follows:
5.2.4.1. Remove the facers on the envelope
component sample, while minimally
disturbing the foam.
5.2.4.2. Measure the thickness of each facer
in 4 locations for a total of 4 measurements
if 1 facer is removed, and a total of 8
measurements if 2 facers are removed. The
average of all facer measurements shall be the
thickness of the facers, tfacers, in.
5.2.4.3. The average total thickness of the
foam, tfoam, in., shall be determined as
follows:
Where:
tc = the average thickness of the center of the
envelope component, in., as determined
per sections 5.2.3.1 and 5.2.3.2 of this
appendix;
Ac = the surface area of the center of the
envelope component, in2., as determined
per section 5.2.3.3 of this appendix;
tp = the average thickness of the perimeter of
the envelope component, in., as
determined per sections 5.2.1.1 and
5.2.1.2 of this appendix;
Ap = the average thickness of the center of the
envelope component, in2, as determined
per section 5.2.1.3 of this appendix;
tfacers = the average thickness of the facers of
the envelope component, in., as
determined per section 5.2.4.2 of this
appendix.
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ER04MY23.026</GPH> ER04MY23.027</GPH>
(g) Annex A2 Equipment Error Analysis,
is inapplicable,
(h) Appendix X1 is inapplicable,
(i) Appendix X2 Response of Heat Flux
Transducers, is inapplicable, and
(j) Appendix X3 Proven Performance of a
Heat Flow Apparatus, is inapplicable.
0.2 [Reserved]
ER04MY23.025</GPH>
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5.2.5. Cutting, measuring, and determining
parallelism and flatness of a 1-inch-thick
specimen for test from the center of the cut
envelope component sample.
5.2.5.1. Cut a 1 ± 0.1-inch-thick specimen
from the center of the cut envelope sample.
The 1-inch-thick test specimen shall be cut
from the point that is equidistant from both
edges of the sample (i.e., shall be cut from the
center point that would be directly between
the interior and exterior space of the walkin).
5.2.5.2. Document through measurement or
photographs with measurement indicators
that the specimen was taken from the center
of the sample.
5.2.5.3 After the 1-inch specimen has
been cut, and prior to testing, place the
specimen on a flat surface and allow gravity
to determine the specimen’s position on the
surface. This will be side 1.
5.2.5.4 To determine the flatness of side
1, take at least nine height measurements at
equidistant positions on the specimen (i.e.,
the specimen would be divided into 9
regions and height measurements taken at the
center of each of these nine regions). Contact
with the measurement indicator shall not
indent the foam surface. From the height
measurements taken, determine the least
squares plane for side 1. For each
measurement location, calculate the
theoretical height from the least squares
plane for side 1. Then, calculate the
difference between the measured height and
the theoretical least squares plane height at
each location. The maximum difference
minus the minimum difference out of the
nine measurement locations is the flatness of
side 1. For side 1 of the specimen to be
considered flat, this shall be less than or
equal to 0.03 inches.
5.2.5.5 To determine the flatness of side
2, turn the specimen over and allow gravity
to determine the specimen’s position on the
surface. Repeat section 5.2.5.4 to determine
the flatness of side 2.
5.2.5.6 To determine the parallelism of
the specimen for side 1, calculate the
theoretical height of the least squares plane
at the furthest corners (i.e., at points (0,0),
(0,12), (12,0), and (12,12)) of the 12-inch by
12-inch test specimen. The difference
between the maximum theoretical height and
the minimum theoretical height shall be less
than or equal to 0.03 inches for each side in
order for side 1 to be considered parallel.
5.2.5.7 To determine the parallelism of
the specimen for side 2, repeat section
5.2.5.8 The average thickness of the test
specimen, L, shall be 1 ± 0.1-inches
determined using a minimum of 18 thickness
measurements (i.e., a minimum of 9
measurements on side 1 of the specimen and
a minimum of 9 on side 2 of the specimen).
This average thickness shall be used to
determine the thermal conductivity, or Kfactor.
5.3 K-factor Test. Determine the thermal
conductivity, or K-factor, of the 1-inch-thick
specimen in accordance with the specified
sections of ASTM C518–17.
5.3.1 Test Conditions.
5.3.1.1 For freezer envelope components,
the K-factor of the specimen shall be
determined at an average specimen
temperature of 20 ± 1 degrees Fahrenheit.
5.3.1.2 For cooler envelope components,
the K-factor of the specimen shall be
determined at an average specimen
temperature of 55 ± 1 degrees Fahrenheit.
5.4 R-value Calculation.
5.4.1 For envelope components
consisting of one homogeneous layer of
insulation, calculate the R-value, h-ft2-°F/
Btu, as follows:
Where:
tfoam = the total thickness of the foam, in., as
determined in section 5.2.4 of this
appendix; and
l = K-factor, Btu-in/(h-ft2-°F), as determined
in section 5.3 of this appendix.
5.4.2 For envelope components
consisting of two or more layers of dissimilar
insulating materials (excluding facers or
protective skins), determine the K-factor of
each material as described in sections 5.1
through 5.3 of this appendix. For an envelope
component with N layers of insulating
material, the overall R-value shall be
calculated as follows:
Where:
ti is the thickness of the ith material that
appears in the envelope component,
inches, as determined in section 5.2.4 of
this appendix;
li is the k-factor of the ith material, Btu-in/
(h-ft2-°F), as determined in section 5.3 of
this appendix; and
N is the total number of material layers that
appears in the envelope component.
5.4.3 K-factor test results from a test
sample 1 ± 0.1-inches in thickness may be
used to determine the R-value of envelope
components with various foam thicknesses as
long as the foam throughout the panel depth
is of the same final chemical form and the
test was completed at the same test
conditions that the other envelope
components would be used at. For example,
a K-factor test result conducted at cooler
conditions cannot be used to determine Rvalue of a freezer envelope component.
■
e. Adding sections 3.2.6, 3.2.6.1,
3.2.6.1.1, 3.2.6.1.2, 3.2.6.2, 3.2.6.3,
3.2.6.4, 3.2.7, 3.2.7.1, 3.2.7.2, and 3.2.8;
■ f. Revising sections 3.3.1 and 3.3.3;
■ g. Adding sections 3.3.3.1, 3.3.3.2,
3.3.3.3, 3.3.3.3.1, and 3.3.3.3.2;
■ h. Revising sections 3.3.7, 3.3.7.1, and
3.3.7.2;
■ i. Adding sections 3.3.7.3, 3.3.7.3.1,
and 3.3.7.3.2; and
■ j. Revising section 3.4.2.1.
The additions and revisions read as
follows:
subpart R, appendix C, revised as of January
1, 2022. Beginning October 31, 2023,
representations with respect to energy use of
refrigeration components of walk-in coolers
and walk-in freezers, including compliance
certifications, must be based on testing
conducted in accordance with this appendix.
For any amended standards for walk-in
coolers and freezers published after January
1, 2022, manufacturers must use the results
of testing under appendix C1 to this subpart
to determine compliance. Representations
related to energy consumption must be made
in accordance with appendix C1 when
determining compliance with the relevant
standard. Manufacturers may also use
appendix C1 to certify compliance with any
amended standards prior to the applicable
compliance date for those standards.
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Note: Prior to October 31, 2023,
representations with respect to the energy
use of refrigeration components of walk-in
coolers and walk-in freezers, including
compliance certifications, must be based on
testing conducted in accordance with the
applicable provisions of 10 CFR part 431,
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*
*
*
2.0
Definitions
*
*
The definitions contained in § 431.302 and
AHRI 1250–2009 (incorporated by reference;
see § 431.303) apply to this appendix. When
definitions contained in the standards DOE
has incorporated by reference are in conflict
or when they conflict with this section, the
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ER04MY23.029</GPH>
12. Amend appendix C to subpart R of
part 431 by:
■ a. Adding an introductory note;
■ b. Revising sections 2.0 and 3.1.1;
■ c. Adding sections 3.1.6 and 3.1.7;
■ d. Revising sections 3.2.1 and 3.2.3;
■
Appendix C to Subpart R of Part 431—
Uniform Test Method for the
Measurement of Net Capacity and
AWEF of Walk-In Cooler and Walk-In
Freezer Refrigeration Systems
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hierarchy of precedence shall be in the
following order: § 431.302, AHRI 1250–2009,
and then either AHRI 420–2008
(incorporated by reference; see § 431.303) for
unit coolers or ASHRAE 23.1–2010
(incorporated by reference; see § 431.303) for
dedicated condensing units.
The term ‘‘unit cooler’’ used in AHRI
1250–2009, AHRI 420–2008, and this subpart
shall be considered to address both ‘‘unit
coolers’’ and ‘‘ducted fan coil units,’’ as
appropriate.
3.0
* * *
3.1. * * *
measurements shall be accurate to within
+/¥1.0 °F.
3.1.1. In Table 1, Instrumentation
Accuracy, refrigerant temperature
measurements shall have an accuracy of
+/¥0.5 °F for unit cooler in/out. When
testing high-temperature refrigeration
systems, measurements used to determine
temperature or water vapor content of the air
(i.e., wet-bulb or dew point) shall be accurate
to within +/¥0.25 °F; all other temperature
3.1.6. Test Operating Conditions for CO2 Unit
Coolers
For medium-temperature CO2 unit coolers,
conduct tests using the test conditions
specified in table 17 of this appendix. For
low-temperature CO2 unit coolers, conduct
tests using the test conditions specified in
table 18 of this appendix.
*
*
*
*
*
TABLE 17—TEST OPERATING CONDITIONS FOR MEDIUM-TEMPERATURE CO2 UNIT COOLERS
Unit
cooler
air entering
dry-bulb,
°F
Unit
cooler
air
entering
relative
humidity,
%
Off-Cycle Power .............................
35
Refrigeration Capacity,
Condition A.
35
Test description
Ambient
Suction
dew
point
temp, °F
Liquid inlet
bubble point
temperature
°F
Liquid
inlet
subcooling,
°F
Compressor
capacity
Test objective
<50
..................
......................
......................
Compressor On ....
<50
25
38
5
Compressor Off ....
Measure fan input power during
compressor off-cycle.
Determine Net Refrigeration Capacity of Unit Cooler.
Notes:
1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used.
TABLE 18—TEST OPERATING CONDITIONS FOR LOW-TEMPERATURE CO2 UNIT COOLERS
Unit
cooler
air entering
dry-bulb,
°F
Unit
cooler
air
entering
relative
humidity,
%
Off-Cycle Power .............................
¥10
Refrigeration Capacity, Ambient
Condition A.
Defrost ............................................
Test description
Suction
dew
point
temp, °F
Liquid inlet
bubble point
temperature
°F
Liquid
inlet
subcooling,
°F
Compressor
capacity
Test objective
<50
..................
......................
......................
Compressor Off ....
¥10
<50
¥20
38
5
Compressor On ....
¥10
<50
..................
......................
......................
Compressor Off ....
Measure fan input power during
compressor off cycle.
Determine Net Refrigeration Capacity of Unit Cooler.
Test according to Appendix C
Section C11 of AHRI 1250–
2009.
1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used.
3.1.7. Test Operating Conditions for HighTemperature Unit Coolers
For high-temperature cooler unit coolers,
conduct tests using the test conditions
specified in table 19 of this appendix.
TABLE 19—TEST OPERATING CONDITIONS FOR HIGH-TEMPERATURE UNIT COOLERS
Test description
ddrumheller on DSK120RN23PROD with RULES2
Off-Cycle .........................................
Refrigeration Capacity Suction A ...
Unit
cooler
air entering
dry-bulb,
°F
Unit
cooler
air
entering
relative
humidity,
%1
Suction
dew
point
temp, °F 2 3
55
55
55
55
..................
38
Liquid inlet
bubble point
temperature
°F
105
105
Liquid
inlet
subcooling,
°F
9
9
Compressor
capacity
Test objective
Compressor Off ....
Compressor On ....
Measure fan input power.
Determine Net Refrigeration Capacity of Unit Cooler.
Notes:
1 The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%.
2 Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used.
3 Suction Dew Point shall be measured at the Unit Cooler Exit.
3.2. * * *
3.2.1. Refrigerant Temperature Measurements
In AHRI 1250–2009 appendix C, section
C3.1.6, any refrigerant temperature
measurements entering and leaving the unit
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cooler may use sheathed sensors immersed in
the flowing refrigerant instead of
thermometer wells. When testing a
condensing unit alone, measure refrigerant
liquid temperature leaving the condensing
unit using thermometer wells as described in
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AHRI 1250–2009 appendix C, section C3.1.6
or sheathed sensors immersed in the flowing
refrigerant. For all of these cases, if the
refrigerant tube outer diameter is less than 1⁄2
inch, the refrigerant temperature may be
measured using the average of two
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temperature measuring instruments with a
minimum accuracy of ±0.5 °F placed on
opposite sides of the refrigerant tube
surface—resulting in a total of up to 8
temperature measurement devices used for
the DX Dual Instrumentation method. In this
case, the refrigerant tube shall be insulated
with 1-inch thick insulation from a point 6
inches upstream of the measurement location
to a point 6 inches downstream of the
measurement location. Also, to comply with
this requirement, the unit cooler entering
measurement location may be moved to a
location 6 inches upstream of the expansion
device and, when testing a condensing unit
alone, the entering and leaving measurement
locations may be moved to locations 6 inches
from the respective service valves.
*
*
*
*
*
3.2.3. Subcooling at Refrigerant Mass Flow
Meter
In appendix C, section C3.4.5 of AHRI
1250–2009 (incorporated by reference; see
§ 431.303), and in section 7.1.2 of ASHRAE
23.1–2010 (incorporated by reference; see
§ 431.303) when verifying subcooling at the
mass flow meters, only the sight glass and a
temperature sensor located on the tube
surface under the insulation are required.
Subcooling shall be verified to be within the
3 °F requirement downstream of flow meters
located in the same chamber as a condensing
unit under test and upstream of flow meters
located in the same chamber as a unit cooler
under test, rather than always downstream as
indicated in AHRI 1250–2009, section C3.4.5
or always upstream as indicated in section
7.1.2 of ASHRAE 23.1–2010. If the
subcooling is less than 3 °F, cool the line
between the condensing unit outlet and this
location to achieve the required subcooling.
When providing such cooling while testing a
matched pair, (a) set up the line-cooling
system and also set up apparatus to heat the
liquid line between the mass flow meters and
the unit cooler, (b) when the system has
achieved steady state without activation of
the heating and cooling systems, measure the
liquid temperature entering the expansion
valve for a period of at least 30 minutes, (c)
activate the cooling system to provide the
required subcooling at the mass flow meters,
(d) if necessary, apply heat such that the
temperature entering the expansion valve is
within 0.5 0F of the temperature measured
during step (b), and (e) proceed with
measurements once condition (d) has been
verified.
*
*
*
*
*
3.2.6. Installation Instructions
Manufacturer installation instructions refer
to the instructions that are applied to the unit
(i.e., as a label) or that come packaged with
the unit. Online installation instructions are
acceptable only if the version number or date
of publication is referenced on the unit label
or in the documents that are packaged with
the unit.
3.2.6.1 Installation Instruction Hierarchy
when available installation instructions are
in conflict
3.2.6.1.1 If a manufacturer installation
instruction provided on the label(s) applied
to the unit conflicts with the manufacturer
installation instructions that are shipped
with the unit, the instructions on the unit’s
label take precedence.
3.2.6.1.2 Manufacturer installation
instructions provided in any documents that
are packaged with the unit take precedence
over any manufacturer installation
instructions provided online.
3.2.6.2 For testing of attached split
systems, the manufacturer installation
instructions for the dedicated condensing
unit shall take precedence over the
manufacturer installation instructions for the
unit cooler.
3.2.6.3 Unit setup shall be in accordance
with the manufacturer installation
instructions (laboratory installation
instructions shall not be used).
3.2.6.4 Achieving test conditions shall
always take precedence over installation
instructions.
3.2.7. Refrigerant Charging and Adjustment
of Superheat and Subcooling.
All dedicated condensing systems
(dedicated condensing units tested alone,
matched pairs, and single packaged
dedicated systems) that use flooding of the
condenser for head pressure control during
low-ambient-temperature conditions shall be
charged, and superheat and/or subcooling
shall be set, at Refrigeration C test conditions
unless otherwise specified in the installation
instructions.
If after being charged at Refrigeration C
condition the unit under test does not
28847
operate at the Refrigeration A condition due
to high pressure cut out, refrigerant shall be
removed in increments of 4 ounces or 5
percent of the test unit’s receiver capacity,
whichever quantity is larger, until the unit
operates at the Refrigeration A condition. All
tests shall be run at this final refrigerant
charge. If less than 0 °F of subcooling is
measured for the refrigerant leaving the
condensing unit when testing at B or C
condition, calculate the refrigerant-enthalpybased capacity (i.e., when using the DX dual
instrumentation, the DX calibrated box, or
single-packaged unit refrigerant enthalpy
method) assuming that the refrigerant is at
saturated liquid conditions at the condensing
unit exit.
All dedicated condensing systems that do
not use a flooded condenser design shall be
charged at Refrigeration A test conditions
unless otherwise specified in the installation
instructions.
If the installation instructions give a
specified range for superheat, sub-cooling, or
refrigerant pressure, the average of the range
shall be used as the refrigerant charging
parameter target and the test condition
tolerance shall be ±50 percent of the range.
Perform charging of near-azeotropic and
zeotropic refrigerants only with refrigerant in
the liquid state. Once the correct refrigerant
charge is determined, all tests shall run until
completion without further modification.
3.2.7.1. When charging or adjusting
superheat/subcooling, use all pertinent
instructions contained in the installation
instructions to achieve charging parameters
within the tolerances. However, in the event
of conflicting charging information between
installation instructions, follow the
installation instruction hierarchy listed in
section 3.2.6. of this appendix. Conflicting
information is defined as multiple conditions
given for charge adjustment where all
conditions specified cannot be met. In the
event of conflicting information within the
same set of charging instructions (e.g., the
installation instructions shipped with the
dedicated condensing unit), follow the
hierarchy in table 1 of this section for
priority. Unless the installation instructions
specify a different charging tolerance, the
tolerances identified in table 1 of this section
shall be used.
TABLE 1—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF REFRIGERANT
CONDITIONS
Fixed orifice
ddrumheller on DSK120RN23PROD with RULES2
Priority
Expansion valve
Parameter with installation
instruction target
Tolerance
Parameter with installation
instruction target
1 ........
Superheat ..................................
±2.0 °F ......................................
Subcooling ................................
2 ........
±4.0 psi or ±1.0 °F ....................
High Side Pressure or Saturation Temperature.
Superheat ..................................
4 ........
High Side Pressure or Saturation Temperature.
Low Side Pressure or Saturation Temperature.
Low Side Temperature .............
±2.0 °F ......................................
5 ........
High Side Temperature .............
±2.0 °F ......................................
3 ........
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±2.0 psi or ±0.8 °F ....................
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Low Side Pressure or Saturation Temperature.
Approach Temperature .............
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E:\FR\FM\04MYR2.SGM
Tolerance
10% of the Target Value; No
less than ±0.5 °F, No more
than ±2.0 °F.
±4.0 psi or ±1.0 °F.
±2.0 °F.
±2.0 psi or ±0.8 °F.
±1.0 °F.
04MYR2
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TABLE 1—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF REFRIGERANT
CONDITIONS—Continued
Fixed orifice
Priority
6 ........
Parameter with installation
instruction target
Tolerance
Parameter with installation
instruction target
Charge Weight ..........................
±2.0 oz ......................................
Charge Weight ..........................
3.2.7.2. Dedicated Condensing Unit. If the
Dedicated Condensing Unit includes a
receiver and the subcooling target leaving the
condensing unit provided in installation
instructions cannot be met without fully
filling the receiver, the subcooling target
shall be ignored. Likewise, if the Dedicated
Condensing unit does not include a receiver
and the subcooling target leaving the
condensing unit cannot be met without the
unit cycling off on high pressure, the
subcooling target can be ignored. Also, if no
instructions for charging or for setting
subcooling leaving the condensing unit are
provided in the installation instructions, the
refrigeration system shall be set up with a
charge quantity and/or exit subcooling such
that the unit operates during testing without
shutdown (e.g., on a high-pressure switch)
and operation of the unit is otherwise
consistent with the requirements of the test
procedure of this appendix and the
installation instructions.
3.2.8. Chamber Conditioning using the Unit
Under Test.
In appendix C, section C6.2 of AHRI 1250–
2009, for applicable system configurations
(matched pairs, single-packaged refrigeration
systems, and standalone unit coolers), the
unit under test may be used to aid in
achieving the required test chamber
conditions prior to beginning any steady state
test. However, the unit under test must be
inspected and confirmed to be free from frost
before initiating steady state testing.
*
*
*
*
*
3.3. * * *
3.3.1. For unit coolers tested alone, use test
procedures described in AHRI 1250–2009 for
testing unit coolers for use in mix-match
system ratings, except that for the test
conditions in tables 15 and 16 of this
appendix, use the Suction A saturation
condition test points only. Also, for unit
coolers tested alone, other than hightemperature unit coolers, use the calculations
in section 7.9 of AHRI 1250–2009 to
determine AWEF and net capacity described
in AHRI 1250–2009 for unit coolers matched
to parallel rack systems.
*
*
*
*
*
3.3.3. Evaporator Fan Power.
3.3.3.1. Ducted Evaporator Air.
ddrumheller on DSK120RN23PROD with RULES2
Expansion valve
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For ducted fan coil units with ducted
evaporator air, or that can be installed with
or without ducted evaporator air: Connect
ductwork on both the inlet and outlet
connections and determine external static
pressure as described in ASHRAE 37
(incorporated by reference; see § 431.303),
sections 6.4 and 6.5. Use pressure
measurement instrumentation as described in
ASHRAE 37, section 5.3.2. Test at the fan
speed specified in manufacturer installation
instructions—if there is more than one fan
speed setting and the installation instructions
do not specify which speed to use, test at the
highest speed. Conduct tests with the
external static pressure equal to 50 percent of
the maximum external static pressure
allowed by the manufacturer for system
installation within a tolerance of ¥0.00/
+0.05 in. wc. Set the external static pressure
by symmetrically restricting the outlet of the
test duct. Alternatively, if using the indoor
air enthalpy method to measure capacity, set
external static pressure by adjusting the fan
of the airflow measurement apparatus. In
case of conflict, these requirements for
setting evaporator airflow take precedence
over airflow values specified in manufacturer
installation instructions or product literature.
3.3.3.2. Unit Coolers or Single-Packaged
Systems that are not High-Temperature
Refrigeration Systems.
Use appendix C, section C10 of AHRI
1250–2009 for off-cycle evaporator fan
testing, with the exception that evaporator
fan controls using periodic stir cycles shall
be adjusted so that the greater of a 50 percent
duty cycle (rather than a 25 percent duty
cycle) or the manufacturer default is used for
measuring off-cycle fan energy. For
adjustable-speed controls, the greater of 50
percent fan speed (rather than 25 percent fan
speed) or the manufacturer’s default fan
speed shall be used for measuring off-cycle
fan energy. Also, a two-speed or multi-speed
fan control may be used as the qualifying
evaporator fan control. For such a control, a
fan speed no less than 50 percent of the
speed used in the maximum capacity tests
shall be used for measuring off-cycle fan
energy.
3.3.3.3. High-Temperature Refrigeration
Systems.
3.3.3.3.1. The evaporator fan power
consumption shall be measured in
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Tolerance
0.5% or 1.0 oz, whichever is
greater.
accordance with the requirements in section
C3.5 of AHRI 1250–2009. This measurement
shall be made with the fan operating at full
speed, either measuring unit cooler or total
system power input upon the completion of
the steady state test when the compressor
and the condenser fan of the walk-in system
are turned off, or by submetered
measurement of the evaporator fan power
during the steady state test.
Section C3.5 of AHRI 1250–2009 is revised
to read:
Evaporator Fan Power Measurement.
The following shall be measured and
recorded during a fan power test.
EFcomp,on Total electrical power input to fan
motor(s) of Unit Cooler, W
FS Fan speed(s), rpm
N Number of motors
Pb Barometric pressure, in. Hg
Tdb Dry-bulb temperature of air at inlet, °F
Twb Wet-bulb temperature of air at inlet, °F
V Voltage of each phase
For a given motor winding configuration,
the total power input shall be measured at
the highest nameplate voltage. For threephase power, voltage imbalance shall be no
more than 2%.
3.3.3.3.2. Evaporator fan power for the offcycle is equal to the on-cycle evaporator fan
power with a run time of 10 percent of the
off-cycle time.
EFcomp,off = 0.1 × EFcomp,on
*
*
*
*
*
3.3.7. Calculations for Unit Coolers Tested
Alone.
3.3.7.1. Unit Coolers that are not HighTemperature Unit Coolers.
Calculate the AWEF and net capacity using
the calculations in AHRI 1250–2009, section
7.9.
3.3.7.2 High-Temperature Unit Coolers.
Calculate AWEF on the basis that walk-in
box load is equal to half of the system net
capacity, without variation according to high
and low load periods, and with EER set
according to tested evaporator capacity, as
follows:
The net capacity, q˙mix,evap, is determined
from the test data for the unit cooler at the
38 °F suction dewpoint.
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enthalpy entering the unit cooler. The
temperature measurement requirements of
appendix C, section C3.1.6 of AHRI 1250–
2009 and modified by section 3.2.1 of this
appendix shall apply only to the condensing
unit exit rather than to the unit cooler inlet
and outlet, and they shall be applied for two
measurements when using the DX Dual
Instrumentation test method.
determine compliance. Representations
related to energy consumption must be made
in accordance with this appendix when
determining compliance with the relevant
standard. Manufacturers may also use this
appendix to certify compliance with any
amended standards prior to the applicable
compliance date for those standards.
*
0. Incorporation by Reference
*
*
*
*
■ 13. Add appendix C1 to subpart R of
part 431 to read as follows:
Appendix C1 to Subpart R of Part 431—
Uniform Test Method for the
Measurement of Net Capacity and
AWEF2 of Walk-In Cooler and Walk-In
Freezer Refrigeration Systems
Note: Prior to October 31, 2023,
representations with respect to the energy
use of refrigeration components of walk-in
coolers and walk-in freezers, including
compliance certifications, must be based on
testing conducted in accordance with the
applicable provisions for 10 CFR part 431,
subpart R, appendix C, revised as of January
1, 2022. Beginning October 31, 2023,
representations with respect to energy use of
refrigeration components of walk-in coolers
and walk-in freezers, including compliance
certifications, must be based on testing
conducted in accordance with appendix C to
this subpart.
For any amended standards for walk-in
coolers and walk-in freezers published after
January 1, 2022, manufacturers must use the
results of testing under this appendix to
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DOE incorporated by reference in
§ 431.303, the entire standard for AHRI 1250–
2020, ANSI/ASHRAE 16, ANSI/ASHRAE
23.1–2010, ANSI/ASHRAE 37, ANSI/
ASHRAE 41.1, ANSI/ASHRAE 41.3, ANSI/
ASHRAE 41.6, and ANSI/ASHRAE 41.10.
However, certain enumerated provisions of
these standards, as set forth in sections 0.1
through 0.8 of this appendix are inapplicable.
To the extent there is a conflict between the
terms or provisions of a referenced industry
standard and the CFR, the CFR provisions
control. To the extent there is a conflict
between the terms or provisions of AHRI
1250–2020, ANSI/ASHRAE 16, ANSI/
ASHRAE 23.1–2010, ANSI/ASHRAE 37,
ANSI/ASHRAE 41.1, ANSI/ASHRAE 41.3,
ANSI/ASHRAE 41.6, and ANSI/ASHRAE
41.10, the AHRI 1250–2020 provisions
control.
0.1 AHRI 1250–2020
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 9 Minimum Data Requirements
for Published Rating, is inapplicable
(d) Section 10 Marking and Nameplate
Data, is inapplicable
E:\FR\FM\04MYR2.SGM
04MYR2
ER04MY23.031</GPH>
Where:
B˙L is the non-equipment-related box load;
LF is the load factor; and
Other symbols are as defined in section 8 of
AHRI 1250–2009.
3.3.7.3. If the unit cooler has variablespeed evaporator fans that vary fan speed in
response to load, then:
3.3.7.3.1. When testing to certify
compliance with the energy conservation
standards in § 431.306, fans shall operate at
full speed during on-cycle operation. Do not
conduct the calculations in AHRI 1250–2009,
section 7.9.3. Instead, use AHRI 1250–2009,
section 7.9.2 to determine the system’s
AWEF.
3.3.7.3.2. When calculating the benefit for
the inclusion of variable-speed evaporator
fans that modulate fan speed in response to
load for the purpose of making
representations of efficiency, use AHRI 1250–
2009, section 7.9.3 to determine the system
AWEF.
3.4. * * *
3.4.2. * * *
3.4.2.1. For calculating enthalpy leaving
the unit cooler to calculate gross capacity, (a)
the saturated refrigerant temperature (dew
point) at the unit cooler coil exit, Tevap, shall
be 25 °F for medium-temperature systems
(coolers) and ¥20 °F for low-temperature
systems (freezers), and (b) the refrigerant
temperature at the unit cooler exit shall be
35 °F for medium-temperature systems
(coolers) and ¥14 °F for low-temperature
systems (freezers). For calculating gross
capacity, the measured enthalpy at the
condensing unit exit shall be used as the
ER04MY23.030</GPH>
ddrumheller on DSK120RN23PROD with RULES2
Where:
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(e) Section 11 Conformance Conditions, is
inapplicable
0.2 ANSI/ASHRAE 16
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Normative Appendices E–M, are
inapplicable
(e) Informative Appendices N–R, are
inapplicable
0.3 ANSI/ASHRAE 23.1–2010
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
0.4 ANSI/ASHRAE 37
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Informative Appendix A Classifications
of Unitary Air-conditioners and Heat
Pumps, is inapplicable.
0.5 ANSI/ASHRAE 41.1
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 9 Test Report, is inapplicable
(e) Informative Appendices A–C, are
inapplicable
0.6 ANSI/ASHRAE 41.3
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 6 Instrument Types
(informative), is inapplicable
(e) Section 8 Test Report, is inapplicable
(f) Informative Annexes A–D, are
inapplicable
0.7 ANSI/ASHRAE 41.6
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 9 Test Report, is inapplicable
(e) Informative Appendices A–D, are
inapplicable
0.8 ANSI/ASHRAE 41.10
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 10 Test Report, is inapplicable
(e) Informative Annexes A–D, are
inapplicable
ddrumheller on DSK120RN23PROD with RULES2
1. Scope
This appendix covers the test requirements
used to determine the net capacity and the
AWEF2 of the refrigeration system of a walkin cooler or walk-in freezer.
2. Definitions
2.1. Applicable Definitions
The definitions contained in § 431.302,
AHRI 1250–2020, ANSI/ASHRAE 37, and
ANSI/ASHRAE 16 apply to this appendix.
When definitions in standards incorporated
by reference are in conflict or when they
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conflict with this section, the hierarchy of
precedence shall be in the following order:
§ 431.302, AHRI 1250–2020, and then either
ANSI/ASHRAE 37 or ANSI/ASHRAE 16.
The term ‘‘unit cooler’’ used in AHRI
1250–2020 and this subpart shall be
considered to address both ‘‘unit coolers’’
and ‘‘ducted fan coil units,’’ as appropriate.
2.2. Additional Definitions
2.2.1. Digital Compressor means a
compressor that uses mechanical means for
disengaging active compression on a cyclic
basis to provide a reduced average refrigerant
flow rate in response to a control system
input signal.
2.2.2. Displacement Ratio, applicable to
staged positive displacement compressor
systems, means the swept volume rate, e.g. in
cubic centimeters per second, of a given
stage, divided by the swept volume rate at
full capacity.
2.2.3. Duty Cycle, applicable to digital
compressors, means the fraction of time that
the compressor is engaged and actively
compressing refrigerant.
2.2.4. Maximum Speed, applicable to
variable-speed compressors, means the
maximum speed at which the compressor
will operate under the control of the
dedicated condensing system control system
for extended periods of time, i.e. not
including short-duration boost-mode
operation.
2.2.5. Minimum Speed, applicable to
variable-speed compressors, means the
minimum compressor speed at which the
compressor will operate under the control of
the dedicated condensing system control
system.
2.2.6. Multiple-Capacity, applicable for
describing a refrigeration system, indicates
that it has three or more stages (levels) of
capacity.
2.2.7. Speed Ratio, applicable to variablespeed compressors, means the ratio of
operating speed to the maximum speed.
3. Test Methods, Measurements, and
Calculations
Determine the Annual Walk-in Energy
Factor (AWEF2) and net capacity of walk-in
cooler and walk-in freezer refrigeration
systems by conducting the test procedure set
forth in AHRI 1250–2020, with the
modifications to that test procedure provided
in this section. However, certain sections of
AHRI 1250–2020, ANSI/ASHRAE 37, and
ANSI/ASHRAE 16 are not applicable, as set
forth in sections 0.1, 0.2, and 0.3 of this
appendix. Round AWEF2 measurements to
the nearest 0.01 Btu/Wh. Round net capacity
measurements as indicated in table 1 of this
appendix.
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TABLE 1—ROUNDING OF REFRIGERATION SYSTEM NET CAPACITY
Net capacity range, Btu/h
<20,000 ...................................................
≥20,000 and <38,000 ..............................
≥38,000 and <65,000 ..............................
≥65,000 ...................................................
Rounding
multiple,
Btu/h
100
200
500
1,000
The following sections of this appendix
provide additional instructions for testing. In
cases where there is a conflict, the language
of this appendix takes highest precedence,
followed by AHRI 1250–2020, then ANSI/
ASHRAE 37 or ANSI/ASHRAE 16. Any
subsequent amendment to a referenced
document by the standard-setting
organization will not affect the test procedure
in this appendix, unless and until the test
procedure is amended by DOE. Material is
incorporated as it exists on the date of the
approval, and a notification of any change in
the incorporation will be published in the
Federal Register.
3.1. Instrumentation Accuracy and Test
Tolerances
Use measuring instruments as described in
section 4.1 of AHRI 1250–2020, with the
following additional requirement.
3.1.1. Electrical Energy Input measured in
Wh with a minimum accuracy of ±0.5% of
reading (for Off-Cycle tests per footnote 5 of
Table C3 in section C3.6.2 of AHRI 1250–
2020).
3.2. Test Operating Conditions
Test conditions used to determine AWEF2
shall be as specified in Tables 4 through 17
of AHRI 1250–2020. Tables 7 and 11 of AHRI
1250–2020, labeled to apply to variablespeed outdoor matched-pair refrigeration
systems, shall also be used for testing
variable-capacity single-packaged outdoor
refrigeration systems, and also for testing
multiple-capacity matched-pair or singlepackaged outdoor refrigeration systems. Test
conditions used to determine AWEF2 for
refrigeration systems not specifically
identified in AHRI 1250–2020 are as
enumerated in sections 3.5.1 through 3.5.6 of
this appendix.
3.2.1 Test Operating Conditions for HighTemperature Refrigeration Systems
For fixed-capacity high-temperature
matched-pair or single-packaged refrigeration
systems with indoor condensing units,
conduct tests using the test conditions
specified in table 2 of this appendix. For
fixed-capacity high-temperature matchedpair or single-packaged refrigeration systems
with outdoor condensing units, conduct tests
using the test conditions specified in table 3
of this appendix. For high-temperature unit
coolers tested alone, conduct tests using the
test conditions specified in table 4 of this
appendix.
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TABLE 2—TEST OPERATING CONDITIONS FOR FIXED-CAPACITY HIGH-TEMPERATURE INDOOR MATCHED PAIR OR SINGLEPACKAGED REFRIGERATION SYSTEMS
Unit cooler
air entering
dry-bulb, °F
Unit cooler
air entering
relative
humidity,
%1
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb,
°F
Compressor
status
Test objective
Off-Cycle Power .......................
55
55
....................
....................
Compressor Off ...
Refrigeration Capacity A ..........
55
55
90
3 75, 4 65
Compressor On ...
Measure total input wattage during compressor off˙ Fcomp,off).2
˙ cu,off + E
cycle, (E
Determine Net Refrigeration Capacity of Unit Cooler, input power, and EER at Test Condition.
Test description
Notes:
1 The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%.
2 Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250–2020.
3 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
4 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is located in
the outdoor room.
TABLE 3—TEST OPERATING CONDITIONS FOR FIXED-CAPACITY HIGH-TEMPERATURE OUTDOOR MATCHED-PAIR OR
SINGLE-PACKAGED REFRIGERATION SYSTEMS
Test description
Unit cooler
air entering
dry-bulb, °F
Unit cooler
air entering
relative
humidity,
%1
Condenser
air entering
dry-bulb, °F
55
55
95
Refrigeration Capacity A ..........
Off-Cycle Power, Capacity
A5
55
55
Condenser
air entering
wet-bulb,
°F
Compressor
status
Test objective
3 75, 4 68
Compressor On ...
95
3 75, 4 68
Compressor Off ...
Compressor On ...
Determine Net Refrigeration Capacity of Unit Cooler, input power, and EER at Test Condition.
Measure total input wattage during compressor off˙ Fcomp,off).2
˙ cu,off + E
cycle, (E
Determine Net Refrigeration Capacity of Unit Cooler and system input power at moderate condition.
Measure total input wattage during compressor off˙ Fcomp,off).2
˙ cu,off + E
cycle, (E
Determine Net Refrigeration Capacity of Unit Cooler and system input power at cold condition.
Measure total input wattage during compressor off˙ Fcomp,off).2
˙ cu,off + E
cycle, (E
Refrigeration Capacity B ..........
55
55
59
3 54, 4 46
Off-Cycle Power, Capacity B 5
55
55
59
3 54, 4 46
Compressor Off ...
35
3 34, 4 29
Compressor On ...
35
3 34, 4 29
Compressor Off ...
Refrigeration Capacity C ..........
Off-Cycle Power, Capacity
55
C5
55
55
55
Notes:
1 The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%.
2 Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250–2020.
3 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
4 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is located in
the outdoor room.
TABLE 4—TEST OPERATING CONDITIONS FOR HIGH-TEMPERATURE UNIT COOLERS
Unit cooler
air entering
dry-bulb, °F
Unit cooler
air entering
relative
humidity,
%1
Off-Cycle ........................
55
55
....................
105
Refrigeration Capacity ...
55
55
38
105
Test description
Suction
dew point
temp, °F 3 4
Liquid inlet
bubble point
temperature,
°F
Liquid inlet
subcooling,
°F
Compressor
status
Test objective
9
Compressor Off ...
9
Compressor On ...
Measure unit cooler input wattage during
compressor off-cycle, E˙Fcomp,off.2
Determine Net Refrigeration Capacity of
Unit Cooler, input power, and EER at
Test Condition.
Notes:
1 The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%.
2 Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250–2020.
3 Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used.
4 Suction Dew Point shall be measured at the Unit Cooler Exit.
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3.2.2 Test Operating Conditions for CO2
Unit Coolers
For medium-temperature CO2 Unit Coolers,
conduct tests using the test conditions
specified in table 5 of this appendix. For lowtemperature CO2 Unit Coolers, conduct tests
using the test conditions specified in table 6
of this appendix.
TABLE 5—TEST OPERATING CONDITIONS FOR MEDIUM-TEMPERATURE CO2 UNIT COOLERS
Test title
Unit cooler
air entering
dry-bulb, °F
Unit cooler
air entering
relative
humidity, %
35
<50
Off-Cycle Power ............
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Suction
dew point
temp,3 °F
Liquid inlet
bubble point
temperature,
°F
Liquid inlet
subcooling,
°F
Compressor
operating mode
Test objective
....................
........................
....................
Compressor On ...
Measure unit cooler input wattage during
compressor off-cycle, E˙Fcomp,off.2
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TABLE 5—TEST OPERATING CONDITIONS FOR MEDIUM-TEMPERATURE CO2 UNIT COOLERS—Continued
Test title
Unit cooler
air entering
dry-bulb, °F
Unit cooler
air entering
relative
humidity, %
35
<50
Refrigeration Capacity,
Ambient Condition A.
Suction
dew point
temp,3 °F
Liquid inlet
bubble point
temperature,
°F
25
Liquid inlet
subcooling,
°F
38
5
Compressor
operating mode
Test objective
Compressor Off ...
Determine Net Refrigeration Capacity of
Unit Cooler, q˙mix,rack.
Notes:
1 Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used.
2 Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250–2020.
3 Suction Dew Point shall be measured at the Unit Cooler Exit conditions.
TABLE 6—TEST OPERATING CONDITIONS FOR LOW-TEMPERATURE CO2 UNIT COOLERS
Suction
dew point
temp,2 °F
Liquid inlet
bubble point
temperature,
°F
Liquid inlet
subcooling,
°F
Compressor
operating mode
Test objective
<50
....................
........................
....................
Compressor Off ...
¥10
<50
¥20
38
5
Compressor On ...
¥10
<50
....................
........................
....................
Compressor Off ...
Measure unit cooler input wattage during
compressor off-cycle, E˙Fcomp,off.2
Determine Net Refrigeration Capacity of
Unit Cooler, q˙mix,rack.
Test according to Appendix C Section
˙ DF.
˙ F,Q
C10 of AHRI 1250–2020, D
Unit cooler
air entering
dry-bulb, °F
Unit cooler
air entering
relative
humidity, %
Off-Cycle Power ............
¥10
Refrigeration Capacity,
Ambient Condition A.
Defrost ...........................
Test title
Notes:
1 Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used.
2 Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250–2020.
3 Suction Dew Point shall be measured at the Unit Cooler Exit conditions.
3.2.3 Test Operating Conditions for TwoCapacity Condensing Units Tested Alone
For two-capacity medium-temperature
outdoor condensing units tested alone,
conduct tests using the test conditions
specified in table 7 of this appendix. For twocapacity medium-temperature indoor
condensing units tested alone, conduct tests
using the test conditions specified in table 8
of this appendix. For two-capacity lowtemperature outdoor condensing units tested
alone, conduct tests using the test conditions
specified in table 9 of this appendix. For twocapacity low-temperature indoor condensing
units tested alone, conduct tests using the
test conditions specified in table 10 of this
appendix.
TABLE 7—TEST OPERATING CONDITIONS FOR TWO-CAPACITY MEDIUM-TEMPERATURE OUTDOOR DEDICATED CONDENSING
UNITS
Test description
Suction
dew point, °F
Return gas, °F
Capacity, Condition A, Low Capacity ................
Capacity, Condition A, High Capacity ...............
Off-Cycle, Condition A .......................................
Capacity, Condition B, Low Capacity ................
Capacity, Condition B, High Capacity ...............
Off-Cycle, Condition B .......................................
Capacity, Condition C, Low Capacity ................
Capacity, Condition C, High Capacity ...............
Off-Cycle, Condition C .......................................
24
23
........................
24
23
........................
24
23
........................
41
41
........................
41
........................
........................
41
41
........................
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F 1
95
95
95
59
59
59
35
35
35
75
75
75
54
54
54
34
34
34
Compressor status
Low Capacity, k=1.
High Capacity, k=2.
Off.
Low Capacity, k=1.
High Capacity, k=2.
Off.
Low Capacity, k=1.
High Capacity, k=2.
Off.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
ddrumheller on DSK120RN23PROD with RULES2
TABLE 8—TEST OPERATING CONDITIONS FOR TWO-CAPACITY MEDIUM-TEMPERATURE INDOOR DEDICATED CONDENSING
UNITS
Test description
Suction
dew point, °F
Return gas, °F
Capacity, Condition A, Low Capacity
Capacity, Condition A, High Capacity
Off-Cycle, Condition A ......................
24
23
........................
41
41
........................
Condenser
air entering
dry-bulb, °F
90
90
90
Condenser
air entering
wet-bulb, °F 1
75
75
75
Compressor status
Low Capacity, k=1.
High Capacity, k=2.
Off.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
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28853
TABLE 9—TEST OPERATING CONDITIONS FOR TWO-CAPACITY LOW-TEMPERATURE OUTDOOR DEDICATED CONDENSING
UNITS
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F 1
Test title
Suction dew
point, °F
Return gas, °F
Capacity, Condition A, Low Capacity
Capacity, Condition A, High Capacity
Off-Cycle, Condition A ......................
Capacity, Condition B, Low Capacity
Capacity, Condition B, High Capacity
Off-Cycle, Condition B ......................
Capacity, Condition C, Low Capacity
Capacity, Condition C, High Capacity.
Off-Cycle, Condition C ......................
¥22
¥22
........................
¥22
¥22
........................
¥22
¥22
5
5
........................
5
5
........................
5
5
95
95
95
59
59
59
35
35
75
75
75
54
54
54
34
34
Low Capacity, k=1.
High Capacity, k=2.
Compressor Off.
Low Capacity, k=1.
High Capacity, k=2.
Compressor Off.
Low Capacity, k=1.
Maximum Capacity, k=2.
........................
........................
35
34
Compressor Off.
Compressor operating mode
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
TABLE 10—TEST OPERATING CONDITIONS FOR TWO-CAPACITY LOW-TEMPERATURE INDOOR DEDICATED CONDENSING
UNITS
Test title
Suction
dew point, °F
Return gas, °F
Capacity, Condition A, Low Capacity
Capacity, Condition A, High Capacity
Off-Cycle, Condition A ......................
¥22
¥22
........................
5
5
........................
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F 1
90
90
90
75
75
75
Compressor operating mode
Low Capacity, k=1.
High Capacity, k=2.
Compressor Off.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
3.2.4 Test Operating Conditions for
Variable- or Multiple-Capacity Condensing
Units Tested Alone
For variable-capacity or multiple-capacity
outdoor medium-temperature condensing
units tested alone, conduct tests using the
test conditions specified in table 11 of this
appendix. For variable-capacity or multiplecapacity indoor medium-temperature
condensing units tested alone, conduct tests
using the test conditions specified in table 12
of this appendix. For variable-capacity or
multiple-capacity outdoor low-temperature
condensing units tested alone, conduct tests
using the test conditions specified in table 13
of this appendix. For variable-capacity or
multiple-capacity indoor low-temperature
condensing units tested alone, conduct tests
using the test conditions specified in table 14
of this appendix.
TABLE 11—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY MEDIUM-TEMPERATURE OUTDOOR
DEDICATED CONDENSING UNITS
Suction
dew point, °F
ddrumheller on DSK120RN23PROD with RULES2
Test description
Capacity, Condition A, Minimum Capacity.
Capacity, Condition A, Intermediate
Capacity.
Capacity, Condition A, Maximum Capacity.
Off-Cycle, Condition A ......................
Capacity, Condition B, Minimum Capacity.
Capacity, Condition B, Intermediate
Capacity.
Capacity, Condition B, Maximum Capacity.
Off-Cycle, Condition B ......................
Capacity, Condition C, Minimum Capacity.
Capacity, Condition C, Intermediate
Capacity.
Capacity, Condition C, Maximum
Capacity.
Off-Cycle, Condition C ......................
Return gas, °F
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F 1
Compressor status
24
41
95
75
Minimum Capacity, k=1.
24
41
95
75
Intermediate Capacity, k=i.
23
41
95
75
Maximum Capacity, k=2
........................
24
........................
41
95
59
75
54
Off.
Minimum Capacity, k=1.
24
41
59
54
Intermediate Capacity, k=i.
23
41
59
54
Maximum Capacity, k=2.
........................
24
........................
41
59
35
54
34
Off.
Minimum Capacity, k=1.
24
41
35
34
Intermediate Capacity, k=i.
23
41
35
34
Maximum Capacity, k=2.
........................
........................
35
34
Off.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
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TABLE 12—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY MEDIUM-TEMPERATURE INDOOR
DEDICATED CONDENSING UNITS
Suction
dew point, °F
Test description
Capacity, Condition A, Minimum Capacity.
Capacity, Condition A, Intermediate
Capacity.
Capacity, Condition A, Maximum Capacity.
Off-Cycle, Condition A ......................
Return gas, °F
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F 1
Compressor status
24
41
90
75
Minimum Capacity, k=1.
24
41
90
75
Intermediate Capacity, k=i.
23
41
90
75
Maximum Capacity, k=2.
........................
........................
90
75
Off.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
TABLE 13—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE OUTDOOR
DEDICATED CONDENSING UNITS
Suction
dew point, °F
Test title
Capacity, Condition A, Minimum Capacity.
Capacity, Condition A, Intermediate
Capacity.
Capacity, Condition A, Maximum Capacity.
Off-Cycle, Condition A ......................
Capacity, Condition B, Minimum Capacity.
Capacity, Condition B, Intermediate
Capacity.
Capacity, Condition B, Maximum Capacity.
Off-Cycle, Condition B ......................
Capacity, Condition C, Minimum Capacity.
Capacity, Condition C, Intermediate
Capacity.
Capacity, Condition C, Maximum
Capacity.
Off-Cycle, Condition C ......................
Return gas, °F
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F 1
Compressor operating mode
¥22
5
95
75
Minimum Capacity, k=1.
¥22
5
95
75
Minimum Capacity, k=i.
¥22
5
95
75
Maximum Capacity, k=2.
........................
¥22
........................
5
95
59
75
54
Compressor Off.
Minimum Capacity, k=1.
¥22
5
59
54
Minimum Capacity, k=i.
¥22
5
59
54
Maximum Capacity, k=2.
........................
¥22
........................
5
59
35
54
34
Compressor Off.
Minimum Capacity, k=1.
¥22
5
35
34
Minimum Capacity, k=i.
¥22
5
35
34
Maximum Capacity, k=2
........................
........................
35
34
Compressor Off.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
TABLE 14—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE INDOOR
DEDICATED CONDENSING UNITS
Suction
dew point, °F
Test title
Capacity, Condition A, Minimum Capacity.
Capacity, Condition A, Intermediate
Capacity.
Capacity, Condition A, Maximum Capacity.
Off-Cycle, Condition A ......................
Return gas, °F
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F 1
Compressor operating mode
¥22
5
90
75
Minimum Capacity, k=1.
¥22
5
90
75
Minimum Capacity, k=i.
¥22
5
90
75
Maximum Capacity, k=2.
........................
........................
90
75
Compressor Off.
ddrumheller on DSK120RN23PROD with RULES2
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
3.2.5 Test Operating Conditions for TwoCapacity Indoor Matched-Pair or SinglePackaged Refrigeration Systems
For two-capacity indoor mediumtemperature matched-pair or single-packaged
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refrigeration systems, conduct tests using the
test conditions specified in table 15 of this
appendix. For two-capacity indoor lowtemperature matched-pair or single-packaged
refrigeration systems, conduct tests using the
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TABLE 15—TEST OPERATING CONDITIONS FOR TWO-CAPACITY MEDIUM-TEMPERATURE INDOOR MATCHED-PAIR OR
SINGLE-PACKAGED REFRIGERATION SYSTEMS
Unit cooler
air entering
relative
humidity, %
Unit cooler
air entering
dry-bulb, °F
Test description
Capacity, Condition A, Low Capacity
Capacity, Condition A, High Capacity
Off-Cycle, Condition A ......................
35
35
35
Condenser
air entering
dry-bulb, °F
<50
<50
<50
Condenser
air entering
wet-bulb, °F
1 75, 2 65
90
90
90
1 75, 2 65
1 75, 2 65
Compressor status
Low Capacity.
High Capacity.
Off.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
equipment is located in the outdoor room.
TABLE 16—TEST OPERATING CONDITIONS FOR TWO CAPACITY LOW-TEMPERATURE INDOOR MATCHED-PAIR OR SINGLEPACKAGED REFRIGERATION SYSTEMS
Unit cooler
air entering
relative
humidity, %
Unit cooler
air entering
dry-bulb, °F
Test description
¥10
¥10
¥10
¥10
Capacity, Condition A, Low Capacity
Capacity, Condition A, High Capacity
Off-Cycle, Condition A ......................
Defrost ...............................................
<50
<50
<50
<50
Condenser
air entering
dry-bulb, °F
90
90
90
........................
Maximum
condenser
air entering
wet-bulb, °F
1 75, 265
1 75, 2 65
1 75, 2 65
........................
Compressor status
Low Capacity.
High Capacity.
Off.
System Dependent.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
equipment is located in the outdoor room.
3.2.6 Test Conditions for Variable- or
Multiple-Capacity Indoor Matched Pair or
Single-Packaged Refrigeration Systems
For variable- or multiple-capacity indoor
medium-temperature matched-pair or single-
packaged refrigeration systems, conduct tests
using the test conditions specified in table 17
of this appendix. For variable- or multiplecapacity indoor low-temperature matchedpair or single-packaged refrigeration systems,
conduct tests using the test conditions
specified in table 18 of this appendix.
TABLE 17—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY MEDIUM-TEMPERATURE INDOOR
MATCHED-PAIR OR SINGLE-PACKAGED REFRIGERATION SYSTEMS
Unit cooler
air entering
relative
humidity, %
Unit cooler
air entering
dry-bulb, °F
Test description
Capacity, Condition A, Minimum Capacity.
Capacity, Condition A, Intermediate
Capacity.
Capacity, Condition A, High Capacity
Off-Cycle, Condition A ......................
Condenser
air entering
dry-bulb, °F
Condenser
air entering
wet-bulb, °F
Compressor status
35
<50
90
1 75, 2 65
Minimum Capacity.
35
<50
90
1 75, 2 65
Intermediate Capacity.
35
35
<50
<50
90
90
1 75, 1 65
Maximum Capacity.
Off.
1 75, 2 65
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
equipment is located in the outdoor room.
TABLE 18—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE INDOOR
MATCHED-PAIR OR SINGLE-PACKAGED REFRIGERATION SYSTEMS
ddrumheller on DSK120RN23PROD with RULES2
Capacity, Condition A, Minimum Capacity.
Capacity, Condition A, Intermediate
Capacity.
Capacity, Condition A, Maximum Capacity.
Off-Cycle, Condition A ......................
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Unit cooler
air entering
relative
humidity, %
Unit cooler
air entering
dry-bulb, °F
Test description
Jkt 259001
Condenser
air entering
dry-bulb, °F
Maximum condenser
air entering
wet-bulb, °F
Compressor status
¥10
<50
90
1 75, 2 65
Minimum Capacity.
¥10
<50
90
1 75, 2 65
Intermediate Capacity.
¥10
<50
90
1 75, 2 65
Maximum Capacity.
¥10
<50
90
1 75, 2 65
Off.
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TABLE 18—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE INDOOR
MATCHED-PAIR OR SINGLE-PACKAGED REFRIGERATION SYSTEMS—Continued
Unit cooler
air entering
relative
humidity, %
Unit cooler
air entering
dry-bulb, °F
Test description
¥10
Defrost ...............................................
<50
Condenser
air entering
dry-bulb, °F
Maximum condenser
air entering
wet-bulb, °F
........................
........................
Compressor status
System Dependent.
Notes:
1 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
equipment is located in the outdoor room.
3.3 Calculation for Walk-in Box Load
3.3.1 For medium- and low-temperature
refrigeration systems with indoor condensing
units, calculate walk-in box loads for high
and low load periods as a function of net
capacity as described in section 6.2.1 of
AHRI 1250–2020.
3.3.2 For medium- and low-temperature
refrigeration systems with outdoor
condensing units, calculate walk-in box loads
for high and low load periods as a function
of net capacity and outdoor temperature as
described in section 6.2.2 of AHRI 1250–
2020.
3.3.3 For high-temperature refrigeration
systems, calculate walk-in box load as
follows.
B˙L = 0.5 · q˙ss,A
Where q˙ss,A is the measured net capacity for
Test Condition A.
3.4 Calculation for Annual Walk-in Energy
Factor (AWEF2)
Calculations used to determine AWEF2
based on performance data obtained for
E˙cu,off is the condensing unit off-cycle power
input, measured as described in section
C3.5 of AHRI 1250–2020.
If the low load period box load, BL˙L, plus
˙ DF, (only
defrost heat contribution, Q
applicable for freezers) is greater than the
minimum net capacity q˙ssk=1:
ER04MY23.033</GPH>
For freezer refrigeration systems, calculate
˙ DF in Btu/h and
defrost heat contribution Q
˙ F in
the defrost average power consumption D
W as a function of steady-state maximum
˙ grossk=2, as
gross refrigeration capacity Q
specified in section C10.2.2 of Appendix C of
AHRI 1250–2020.
3.4.1.3 Net Capacity
Calculate steady-state maximum net
capacity, q˙ssk=2, and minimum net capacity,
q˙ssk=1 as follows:
˙ grossk=2 ¥ 3412 · E˙Fcomp,on
q˙ssk=2 = Q
˙ grossk=1 ¥ 3412 · 0.2 · E˙Fcomp,on
q˙ssk=1 = Q
Where:
˙ grossk=2 and Q
˙ grossk=1 represent gross
Q
refrigeration capacity at maximum and
minimum capacity, respectively.
3.4.1.4 Calculate average power input
during the low load period as follows.
If the low load period box load, BL˙L, plus
˙ DF (only
defrost heat contribution, Q
applicable for freezers), is less than the
minimum net capacity q˙ssk=1:
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ddrumheller on DSK120RN23PROD with RULES2
Where:
E˙ssk=1 is the steady state condensing unit
power input for minimum-capacity
operation.
testing shall be as specified in section 7 of
AHRI 1250–2020 with modifications as
indicated in sections 3.4.7 through 3.4.10 of
this appendix. Calculations used to
determine AWEF2 for refrigeration systems
not specifically identified in sections 7.1.1
through 7.1.6 of AHRI 1250–2020 are
enumerated in sections 3.4.1 through 3.4.6
and 3.4.11 through 3.4.14 of this appendix.
3.4.1 Two-Capacity Condensing Units
Tested Alone, Indoor
3.4.1.1 Unit Cooler Power
Calculate maximum-capacity unit cooler
power during the compressor on period
˙EFcomp,on, in Watts, using Equation 130 of
AHRI 1250–2020 for medium-temperature
refrigeration systems and using Equation 173
of AHRI 1250–2020 for low-temperature
refrigeration systems.
Calculate unit cooler power during the
compressor off period E˙Fcomp,off, in Watts, as
20 percent of the maximum-capacity unit
cooler power during the compressor on
period.
3.4.1.2 Defrost
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
28857
3.4.1.5 Calculate average power input
during the high load period as follows.
3.4.1.6
Calculate the AWEF2 as follows:
3.4.2.3 Net Capacity
Calculate steady-state maximum net
capacity, q˙ssk=2, intermediate net capacity,
q˙ssk=i, and minimum net capacity, q˙ssk=1 as
follows:
˙ grossk=2 ¥ 3412 · E˙Fcomp,on
q˙ssk=2 = Q
˙ grossk=2 ¥ 3412 · Kf · E˙Fcomp,on
q˙ssk=2 = Q
˙ grossk=1 ¥ 3412 · 0.2 · E˙Fcomp,on
q˙ssk=1 = Q
Where:
˙ grossk=2, Q
˙ grossk=i, Q
˙ gross,k=1, and represent
Q
gross refrigeration capacity at maximum,
intermediate, and minimum capacity,
respectively.
Kf is the unit cooler power coefficient for
intermediate capacity operation, set equal to
0.2 to represent low-speed fan operation if
the Duty Cycle for a Digital Compressor, the
Speed Ratio for a Variable-Speed
Compressor, or the Displacement Ratio for a
Multi-Stage Compressor at Intermediate
Capacity is 65% or less, and otherwise set
equal to 1.0.
3.4.2.4 Calculate average power input
during the low load period as follows.
If the low load period box load, BL˙L, plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is less than the
minimum net capacity q˙ssk=1:
Where E˙cu,off, in W, is the condensing unit
off-mode power consumption, measured as
described in section C3.5 of AHRI 1250–
2020.
If the low load period box load BL˙L plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is greater than the
minimum net capacity q˙ssk=1 and less than
the intermediate net capacity q˙ssk=i:
Where:
EERk=1 is the minimum-capacity energy
efficiency ratio, equal to q˙ssk=1 divided by
E˙ssk=1 + 0.2 · E˙Fcomp,on; and
EERk=i is the intermediate-capacity energy
efficiency ratio, equal to q˙ssk=i divided by
E˙ssk=i + Kf · E˙Fcomp,on.
3.4.2.5 Calculate average power input
during the high load period as follows:
If the high load period box load, BL˙H, plus
˙ DF (only
defrost heat contribution, Q
applicable for freezers), is greater than the
minimum net capacity q˙ssk=1 and less than
the intermediate net capacity q˙ssk=i:
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3.4.2 Variable-Capacity or Multistage
Condensing Units Tested Alone, Indoor
3.4.2.1 Unit Cooler Power
Calculate maximum-capacity unit cooler
power during the compressor on period
E˙Fcomp,on as described in section 3.4.1.1 of
this appendix.
Calculate unit cooler power during the
compressor off period E˙Fcomp,off, in Watts, as
20 percent of the maximum-capacity unit
cooler power during the compressor on
period.
3.4.2.2 Defrost
Calculate Defrost parameters as described
in section 4.4.1.2 of this appendix.
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
If the high load period box load, BL˙H, plus
˙ DF (only
defrost heat contribution, Q
applicable for freezers), is greater than the
intermediate net capacity, q˙ssk=i, and less than
the maximum net capacity, q˙ssk=2:
Where:
EERk=2 is the maximum-capacity energy
efficiency ratio, equal to q˙ssk=2 divided by
E˙ssk=2 + E˙Fcomp,on
3.4.3 Two-Capacity Condensing Units
Tested Alone, Outdoor
3.4.3.1 Unit Cooler Power
Calculate maximum-capacity unit cooler
power during the compressor on period
E˙Fcomp,on, in Watts, using Equation 153 of
AHRI 1250–2020 for medium-temperature
refrigeration systems and using Equation 196
of AHRI 1250–2020 for low-temperature
refrigeration systems.
Calculate unit cooler power during the
compressor off period E˙Fcomp,off, in Watts, as
20 percent of the maximum-capacity unit
cooler power during the compressor on
period.
3.4.3.2 Defrost
Calculate Defrost parameters as described
in section 3.4.1.2 of this appendix.
3.4.3.3 Condensing Unit Off-Cycle Power
Calculate Condensing Unit Off-Cycle
Power for temperature tj as follows.
Where E˙cu,off,A and E˙cu,off,C are the Condensing
Unit off-cycle power measurements for
test conditions A and C, respectively,
measured as described in section C3.5 of
AHRI 1250–2020. If tj is greater than 35
°F and less than 59 °F, use Equation 157
of AHRI 1250–2020, and if tj is greater
than or equal to 59 °F and less than 95
°F, use Equation 159 of AHRI 1250–2020.
3.4.3.4 Net Capacity and Condensing Unit
Power Input
Calculate steady-state maximum net
capacity, q˙ssk=2(tj), and minimum net
capacity, q˙ssk=1(tj), and corresponding
condensing unit power input levels E˙ssk=2(tj)
and E˙ssk=1(tj) as a function of outdoor
temperature tj as follows:
If tj ≤ 59 °F:
ER04MY23.042</GPH>
Calculate the AWEF2 as follows.
ER04MY23.039</GPH> ER04MY23.040</GPH>
ER04MY23.041</GPH>
3.4.2.6
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28858
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
28859
E˙ss,Xk=2 and E˙ss,Xk=1 represent condensing unit
power input at maximum and minimum
capacity, respectively for test condition
X.
3.4.3.5 Calculate average power input
during the low load period as follows.
Calculate the temperature, tIL, in the
following equation which the low load
Where E˙cu,off(tj), in W, is the condensing
unit off-mode power consumption for
temperature tj, determined as indicated in
section 3.4.3.3 of this appendix.
3.4.3.6 Calculate average power input
during the high load period as follows.
Calculate the temperature, tIH, in the
following equation which the high load
period box load, BL˙H(tj), plus defrost heat
˙ DF (only applicable for
contribution, Q
freezers), is less than the minimum net
capacity, q˙ssk=1(tj) , by solving the following
equation for tIH:
˙ DF = q˙ssk=1(tIH)
BL˙H(tIH) + Q
Calculate the temperature, tIIH, in the
following equation which the high load
period box load BL˙H(tj) plus defrost heat
period box load, BL˙L(tj), plus defrost heat
˙ DF (only applicable for
contribution, Q
freezers), is less than the minimum net
capacity, q˙ssk=1(tj), by solving the following
equation for tIL:
˙ DF = q˙ssk=1(tIL)
BL˙L(tIL) + Q
For tj < tIL:
For tj ≥ tIL:
˙ DF (only applicable for
contribution Q
freezers) is less than the maximum net
capacity q˙ssk=2(tj), by solving the following
equation for tIIH:
˙ DF = q˙ssk=1(tIIH)
BL˙H(tIIH) + Q
For tj < tIH:
ER04MY23.044</GPH> ER04MY23.045</GPH>
Where:
The capacity level k can equal 1 or 2;
˙ gross,Xk=2 and Q
˙ gross,Xk=1 represent gross
Q
refrigeration capacity at maximum and
minimum capacity, respectively, for test
condition X, which can take on values A,
B, or C;
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If 59 °F < tj:
28860
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
For tIH ≤ tj < tIIH:
For tIIH ≤ tj:
E˙H(tj) = (E˙ssk=2(tj) + E˙Fcomp,on)
3.4.3.7
3.4.4 Variable-Capacity or Multistage
Condensing Units Tested Alone, Outdoor
20 percent of the maximum-capacity unit
cooler power during the compressor on
period.
3.4.4.2 Defrost
Calculate Defrost parameters as described
in section 3.4.1.2 of this appendix.
3.4.4.3 Condensing Unit Off-Cycle Power
Calculate Condensing Unit Off-Cycle
Power for temperature, tj, as described in
section 3.4.3.3 of this appendix.
3.4.4.4 Net Capacity and Condensing Unit
Power Input
Calculate steady-state maximum net
capacity, q˙ssk=2(tj), intermediate net capacity,
q˙ssk=i(tj) , and minimum net capacity, q˙ssk=1(tj),
and corresponding condensing unit power
input levels E˙ssk=2(tj), E˙ssk=i(tj), E˙ssk=1(tj) and as
a function of outdoor temperature, tj, as
follows:
If tj ≤ 59 °F:
ER04MY23.047</GPH> ER04MY23.048</GPH>
If 59 °F < tj:
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3.4.4.1 Unit Cooler Power
Calculate maximum-capacity unit cooler
power during the compressor on period
E˙Fcomp,on as described in section 3.4.1.1 of
this appendix.
Calculate unit cooler power during the
compressor off period E˙Fcomp,on, in Watts, as
Calculate the AWEF2 as follows:
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
operation if the Duty Cycle for a Digital
Compressor, the Speed Ratio for a
Variable-Speed Compressor, or the
Displacement Ratio for a Multi-Stage
Compressor at Intermediate Capacity is
65% or less, and otherwise set equal to
1.0.
3.4.4.5 Calculate average power input
during the low load period as follows.
Calculate the temperature, tIL, in the
following equation which the low load
period box load BL˙L(tj) plus defrost heat
˙ DF (only applicable for
contribution, Q
freezers), is less than the minimum net
Where, E˙cu,off(tj) in W, is the condensing
unit off-mode power consumption for
temperature, tj, determined as indicated in
section 3.4.3.3 of this appendix.
capacity, q˙ssk=1(tj), by solving the following
equation for tIL:
˙ DF = q˙ssk=1(tIL)
BL˙L(tIL) + Q
Calculate the temperature, tVL, in the
following equation which the low load
period box load, BL˙L(tj), plus defrost heat
˙ DF (only applicable for
contribution, Q
freezers), is less than the intermediate net
capacity, q˙ssk=i(tj), by solving the following
equation for tVL:
˙ DF = q˙ssk=i(tVL)
BL˙L(tVL) + Q
For tj < tIL:
For tIL ≤ tj < tVL:
ER04MY23.053</GPH>
Where:
The capacity level k can equal 1, i, or 2;
˙ gross,Xk=2, Q
˙ gross,Xk=i and Q
˙ gross,Xk=1 represent
Q
gross refrigeration capacity at maximum,
intermediate, and minimum capacity,
respectively, for test condition X, which
can take on values A, B, or C;
E˙ss,Xk=2 and E˙ss,Xk=1 represent condensing unit
power input at maximum and minimum
capacity, respectively for test condition
X; and
Kf is the unit cooler power coefficient for
intermediate capacity operation, set
equal to 0.2 to represent low-speed fan
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For tVL ≤ tj:
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28861
28862
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
Where:
EERk=2(tj) is the minimum-capacity energy
efficiency ratio, equal to q˙ssk=1(tj) divided
by E˙ssk=1(tj) + 0.2 E˙Fcomp,on;
EERk=i(tj) is the intermediate-capacity energy
efficiency ratio, equal to q˙ssk=i(tj) divided
by E˙ssk=i(tj) + Kf · E˙Fcomp,on; and
EERk=2(tj) is the maximum-capacity energy
efficiency ratio, equal to q˙ssk=2(tj) divided
by E˙ssk=2(tj) + E˙Fcomp,on
3.4.4.6 Calculate average power input
during the high load period as follows.
Calculate the temperature tVH in the
following equation which the high load
period box load BL˙H(tj) plus defrost heat
˙ DF (only applicable for
contribution Q
freezers) is less than the intermediate net
capacity q˙ssk=i(tj), by solving the following
equation for tVH:
˙ DF = q˙ssk=i(tVH)
BL˙H(tVH) + Q
Calculate the temperature tIIH in the
following equation which the high load
period box load BL˙H(tj) plus defrost heat
˙ DF (only applicable for
contribution Q
freezers) is less than the maximum net
capacity q˙ssk=2(tj), by solving the following
equation for tIIH:
˙ DF = q˙ssk=2(tIIH)
BL˙H(tIIH) + Q
For tj < tVH:
For tVH ≤ tj < tIIH:
For tIIH ≤ tj:
E˙H(tj) = (E˙ssk=2 (tj) + E˙Fcomp,on)
3.4.4.7
3.4.5 Two-Capacity Indoor Matched Pairs or
Single-Packaged Refrigeration Systems Other
Than High-Temperature
Defrost
For freezer refrigeration systems, defrost
˙ DF in Btu/h and the
heat contribution Q
defrost average power consumption D˙F in W
shall be as measured in accordance with
section C10.2.1 of Appendix C of AHRI
1250–2020.
3.4.5.2 Calculate average power input
during the low load period as follows.
If the low load period box load BL˙L plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is less than the
minimum net capacity q˙ssk=1:
operation, measured as described in
AHRI 1250–2020.
E˙Fcomp,off and E˙cu,off, both in W, are the unit
cooler and condensing unit, respectively,
off-mode power consumption, measured
as described in section C3.5 of AHRI
1250–2020.
If the low load period box load BL˙L plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is greater than the
minimum net capacity q˙ssk=1:
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Where:
q˙ssk=1 and E˙ssk=1 are the steady state
refrigeration system minimum net
capacity, in Btu/h, and associated
refrigeration system power input, in W,
respectively, for minimum-capacity
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3.4.5.1
Calculate the AWEF2 as follows:
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
Where q˙ssk=2 and E˙ssk=2 are the steady state
refrigeration system maximum net
capacity, in Btu/h, and associated
refrigeration system power input, in W,
For freezer refrigeration systems, defrost
˙ DF in Btu/h and the
heat contribution Q
defrost average power consumption D˙F in W
shall be as measured in accordance with
section C10.2.1 of Appendix C of AHRI
1250–2020.
3.4.6.2 Calculate average power input
during the low load period as follows.
If the low load period box load BL˙L plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is less than the
minimum net capacity q˙ssk=1:
operation, measured as described in
AHRI 1250–2020; and
E˙Fcomp,off and E˙cu,off, both in W, are the unit
cooler and condensing unit, respectively,
off-mode power consumption, measured
as described in section C3.5 of AHRI
1250–2020.
If the low load period box load BL˙L plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is greater than the
minimum net capacity and less than the
intermediate net capacity q˙ssk=i:
ER04MY23.062</GPH>
Defrost
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ER04MY23.059</GPH> ER04MY23.060</GPH>
Where:
q˙ssk=1 and E˙ssk=1 are the steady state
refrigeration system minimum net
capacity, in Btu/h, and associated
refrigeration system power input, in W,
respectively, for minimum-capacity
ddrumheller on DSK120RN23PROD with RULES2
3.4.5.3 Calculate average power input
during the high load period as follows.
Calculate the AWEF2 as follows:
3.4.6 Variable-Capacity or Multistage
Indoor Matched Pairs or Single-Packaged
Refrigeration Systems Other Than HighTemperature
3.4.6.1
respectively, for maximum-capacity
operation, measured as described in
AHRI 1250–2020.
ER04MY23.061</GPH>
3.4.5.4
28863
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
Where:
EERk=1 is the minimum-capacity energy
efficiency ratio, equal to q˙ssk=1divided by
E˙ssk=1;
q˙ssk=i and E˙ssk=i are the steady state
refrigeration system intermediate net
capacity, in Btu/h, and associated
refrigeration system power input, in W,
respectively, for intermediate-capacity
operation, measured as described in
AHRI 1250–2020.
EERk=i is the intermediate-capacity energy
efficiency ratio, equal to q˙ssk=i divided by
E˙ssk=i.
If the high load period box load BL˙H plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is greater than the
intermediate net capacity q˙ssk=i and less than
the maximum net capacity q˙ssk=2:
Where:
q˙ssk=2 and E˙ssk=2 are the steady state
refrigeration system maximum net
capacity, in Btu/h, and associated
refrigeration system power input, in W,
respectively, for maximum-capacity
operation, measured as described in
AHRI 1250–2020; and
3.4.3.3 of this appendix. Replace the constant
value E˙CU,off in Equations 55 and 70 of AHRI
1250–2020 with the values E˙CU,off(tj), which
vary with outdoor temperature tj.
3.4.7.2 Unit Cooler Off-Cycle Power
Set unit cooler Off-Cycle power E˙Fcomp,off
equal to the average of the unit cooler offcycle power measurements made for test
conditions A, B, and C.
EERk=2 is the maximum-capacity energy
efficiency ratio, equal to q˙ssk=2 divided by
E˙ssk=2.
3.4.6.4 Calculate the AWEF2 as follows.
3.4.7.3 Average Power During the Low
Load Period
Calculate average power for intermediatecapacity compressor operation during the
low load period E˙ss,Lk=v(tj) as described in
section 7.6 of AHRI 1250–2020, except that,
instead of calculating intermediate-capacity
compressor EER using Equation 77 of AHRI
1250–2020, calculate EER as follows.
For tj < tVL:
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For tVL ≤ tj:
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ER04MY23.066</GPH>
3.4.7 Variable-Capacity or Multistage
Outdoor Matched Pairs or Single-Packaged
Refrigeration Systems Other Than HighTemperature
Calculate AWEF2 as described in section
7.6 of AHRI 1250–2020, with the following
revisions.
3.4.7.1 Condensing Unit Off-Cycle Power
Calculate condensing unit off-cycle power
for temperature tj as indicated in section
3.4.6.3 Calculate average power input
during the high load period as follows.
If the high load period box load BL˙H plus
˙ DF (only
defrost heat contribution Q
applicable for freezers) is greater than the
minimum net capacity q˙ssk=1 and less than
the intermediate net capacity q˙ssk=i:
ER04MY23.067</GPH>
28864
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
Where:
EERk=1(tj) is the minimum-capacity energy
efficiency ratio, equal to q˙ssk=1(tj) divided
by E˙ssk=1(tj);
EERk=i(tj) is the intermediate-capacity energy
efficiency ratio, equal to q˙ssk=i (tj) divided
by E˙ssk=i(tj); and
28865
EERk=2(tj) is the maximum-capacity energy
efficiency ratio, equal to q˙ssk=2(tj) divided
by E˙ssk=2(tj)
3.4.7.4 Average Power During the High
Load Period
Calculate average power for intermediatecapacity compressor operation during the
high load period E˙ss,Hk=v(tj) as described in
section 7.6 of AHRI 1250–2020, except that,
instead of calculating intermediate-capacity
compressor EER using Equation 61 of AHRI
1250–2020, calculate EER as follows:
For tj < tVH:
3.4.9 Single-Capacity Outdoor Matched
Pairs or Single-Packaged Refrigeration
Systems Other Than High-Temperature
3.4.10 Single-Capacity Condensing Units,
Outdoor
For tVH ≤ tj:
Where:
B˙L, in Btu/h is the non-equipment-related
box load calculated as described in
section 3.3.3 of this appendix;
E˙Fcomp,off, in W, is the unit cooler off-cycle
power consumption, equal to 0.1 times
the unit cooler on-cycle power
consumption; and
Calculate AWEF2 as described in section
7.9 of AHRI 1250–2020, with the following
revision for Condensing Unit Off-Cycle
Power. Calculate condensing unit off-cycle
power for temperature tj as indicated in
section 3.4.3.3 of this appendix rather than
as indicated in Equations 157, 159, 202, and
204 of AHRI 1250–2020.
3.4.11 High-Temperature Matched Pairs or
Single-Packaged Refrigeration Systems,
Indoor
3.4.11.1
follows:
Calculate Load Factor LF as
q˙ss,A, in Btu/h is the measured net capacity
for test condition A.
3.4.11.2 Calculate the AWEF2 as follows:
ER04MY23.072</GPH>
Calculate AWEF2 as described in section
7.4 of AHRI 1250–2020, with the following
revision for Condensing Unit Off-Cycle
Power and Unit Cooler Off-cycle Power.
Calculate condensing unit off-cycle power for
temperature tj as indicated in section 3.4.3.3
of this appendix. Replace the constant value
E˙CU,off in Equations 13 of AHRI 1250–2020
with the values E˙CU,off(tj), which vary with
outdoor temperature tj. Set unit cooler OffCycle power E˙Fcomp,off equal to the average of
the unit cooler off-cycle power measurements
made for test conditions A, B, and C.
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2020.
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3.4.12 High-Temperature Matched Pairs or
Single-Packaged Refrigeration Systems,
Outdoor
3.4.12.1 Calculate Load Factor LF(tj) for
outdoor temperature tj as follows:
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ER04MY23.069</GPH> ER04MY23.070</GPH>
Where:
E˙ss,A, in W, is the measured system power
input for test condition A; and
E˙cu,off, in W, is the condensing unit off-cycle
power consumption, measured as
ER04MY23.068</GPH>
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3.4.8 Two-Capacity Outdoor Matched Pairs
or Single-Packaged Refrigeration Systems
Other Than High-Temperature
Calculate AWEF2 as described in section
7.5 of AHRI 1250–2020, with the following
revisions for Condensing Unit Off-Cycle
Power and Unit Cooler Off-Cycle Power.
Calculate condensing unit off-cycle power for
temperature tj as indicated in section 3.4.3.3
of this appendix. Replace the constant value
E˙CU,off in Equations 13 and 29 of AHRI 1250–
2020 with the values E˙CU,off(tj), which vary
with outdoor temperature tj. Set unit cooler
Off-Cycle power E˙Fcomp,off equal to the
average of the unit cooler off-cycle power
measurements made for test conditions A, B,
and C.
28866
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
Where:
B˙L, in Btu/h, is the non-equipment-related
box load calculated as described in
section 3.3.3 of this appendix;
E˙Fcomp,off, in W, is the unit cooler off-cycle
power consumption, equal to 0.1 times
the unit cooler on-cycle power
consumption; and
q˙ss(tj), in Btu/h, is the net capacity for
outdoor temperature tj, calculated as
described in section 7.4.2 of AHRI 1250–
2020.
3.4.12.2 Calculate the AWEF2 as follows:
Where:
E˙ss(tj), in W, is the system power input for
temperature tj, calculated as described in
section 7.4.2 of AHRI 1250–2020;
E˙cu,off, in W, is the condensing unit off-cycle
power consumption, measured as
described in section C3.5 of AHRI 1250–
2020; and
nj are the hours for temperature bin j.
3.4.13 High-Temperature Unit Coolers
Tested Alone
Where:
q˙mix,evap, in W, is the net evaporator capacity,
measured as described in AHRI 1250–
2020;
E˙Fcomp,on, in W, is the unit cooler on-cycle
power consumption; and
EER, in W, equals
3.4.13.2
follows:
3.4.13.1 Calculate Refrigeration System
Power Input as follows:
Calculate the load factor LF as
Where:
B˙L, in Btu/h, is the non-equipment-related
box load calculated as described in
section 3.3.3 of this appendix; and
E˙Fcomp,off, in W, is the unit cooler off-cycle
power consumption, equal to 0.1 times
the unit cooler on-cycle power
consumption.
3.4.14
3.5.1 Chamber Conditioning Using the Unit
Under Test
3.5.2 General Modification: Methods of
Testing
In Appendix C, section C5.2.2 of AHRI
1250–2020, for applicable system
configurations (matched pairs, singlepackaged refrigeration systems, and
standalone unit coolers), the unit under test
may be used to aid in achieving the required
test chamber conditions prior to beginning
any steady state test. However, the unit under
test must be inspected and confirmed to be
free from frost before initiating steady state
testing.
3.5.2.1 Refrigerant Temperature
Measurements
When testing a condensing unit alone,
measure refrigerant liquid temperature
leaving the condensing unit, and the
refrigerant vapor temperature entering the
condensing unit as required in section
C7.5.1.1.2 of Appendix C of AHRI 1250–2020
using the same measurement approach
specified for the unit cooler in section C3.1.3
of Appendix C of AHRI 1250–2020. In all
cases in which thermometer wells or
immersed sheathed sensors are prescribed, if
the refrigerant tube outer diameter is less
Calculate AWEF2 as follows:
3.5
Test Method
Test the Refrigeration System in
accordance with AHRI 1250–2020 to
determine refrigeration capacity and power
input for the specified test conditions, with
revisions and additions as described in this
section.
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ddrumheller on DSK120RN23PROD with RULES2
Calculate AWEF2 for CO2 Unit Coolers
Tested Alone using the calculations specified
in in section 7.8 of AHRI 1250–2020 for
calculation of AWEF2 for Unit Cooler Tested
Alone.
ER04MY23.073</GPH>
CO2 Unit Coolers Tested Alone
ER04MY23.076</GPH>
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3.4.13.3
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
than 1⁄2 inch, the refrigerant temperature may
be measured using the average of two
temperature measuring instruments with a
minimum accuracy of ±0.5 °F placed on
opposite sides of the refrigerant tube
surface—resulting in a total of up to 8
temperature measurement devices used for
the DX Dual Instrumentation method. In this
case, the refrigerant tube shall be insulated
with 1-inch thick insulation from a point 6
inches upstream of the measurement location
to a point 6 inches downstream of the
measurement location. Also, to comply with
this requirement, the unit cooler/evaporator
entering measurement location may be
moved to a location 6 inches upstream of the
expansion device and, when testing a
condensing unit alone, the entering and
leaving measurement locations may be
moved to locations 6 inches from the
respective service valves.
3.5.2.2 Mass Flow Meter Location
When using the DX Dual Instrumentation
test method of AHRI 1250–2020, applicable
for unit coolers, dedicated condensing units,
and matched pairs, the second mass flow
meter may be installed in the suction line as
shown in Figure C1 of AHRI 1250–2020.
3.5.2.3 Subcooling at Refrigerant Mass
Flow Meter
In section C3.4.5 of Appendix C of AHRI
1250–2020, when verifying subcooling at the
mass flow meters, only the sight glass and a
temperature sensor located on the tube
surface under the insulation are required.
Subcooling shall be verified to be within the
3 °F requirement downstream of flow meters
located in the same chamber as a condensing
unit under test and upstream of flow meters
located in the same chamber as a unit cooler
under test, rather than always downstream as
indicated in AHRI 1250–2009, section C3.4.5.
If the subcooling is less than 3 °F when
testing a unit cooler, dedicated condensing
unit, or matched pair (not a single-packaged
system), cool the line between the
condensing unit outlet and this location to
achieve the required subcooling. When
providing such cooling while testing a
matched pair (a) set up the line-cooling
system and also set up apparatus to heat the
liquid line between the mass flow meters and
the unit cooler, (b) when the system has
achieved steady state without activation of
the heating and cooling systems, measure the
liquid temperature entering the expansion
valve for a period of at least 30 minutes, (c)
activate the cooling system to provide the
required subcooling at the mass flow meters,
(d) if necessary, apply heat such that the
temperature entering the expansion valve is
within 0.5 °F of the temperature measured
during step (b), and (e) proceed with
measurements once condition (d) has been
verified.
3.5.2.4 Installation Instructions
Manufacturer installation instructions or
installation instructions described in this
section refer to the instructions that come
packaged with or appear on the labels
applied to the unit. This does not include
online manuals.
Installation Instruction Hierarchy: If a
given installation instruction provided on the
label(s) applied to the unit conflicts with the
installation instructions that are shipped
with the unit, the label takes precedence. For
testing of matched pairs, the installation
instructions for the dedicated condensing
unit shall take precedence. Setup shall be in
accordance with the field installation
instructions (laboratory installation
instructions shall not be used). Achieving
test conditions shall always take precedence
over installation instructions.
3.5.2.5. Refrigerant Charging and
Adjustment of Superheat and Subcooling.
All dedicated condensing systems
(dedicated condensing units tested alone,
matched pairs, and single packaged
dedicated systems) that use flooding of the
condenser for head pressure control during
low-ambient-temperature conditions shall be
charged, and superheat and/or subcooling
shall be set, at Refrigeration C test conditions
unless otherwise specified in the installation
instructions.
If after being charged at Refrigeration C
condition the unit under test does not
operate at the Refrigeration A condition due
to high pressure cut out, refrigerant shall be
removed in increments of 4 ounces or 5
28867
percent of the test unit’s receiver capacity,
whichever quantity is larger, until the unit
operates at the Refrigeration A condition. All
tests shall be run at this final refrigerant
charge. If less than 0 °F of subcooling is
measured for the refrigerant leaving the
condensing unit when testing at B or C
condition, calculate the refrigerant-enthalpybased capacity (i.e., when using the DX dual
instrumentation, the DX calibrated box, or
single-packaged unit refrigerant enthalpy
method) assuming that the refrigerant is at
saturated liquid conditions at the condensing
unit exit.
All dedicated condensing systems that do
not use a flooded condenser design shall be
charged at Refrigeration A test conditions
unless otherwise specified in the installation
instructions.
If the installation instructions give a
specified range for superheat, sub-cooling, or
refrigerant pressure, the average of the range
shall be used as the refrigerant charging
parameter target and the test condition
tolerance shall be ±50 percent of the range.
Perform charging of near-azeotropic and
zeotropic refrigerants only with refrigerant in
the liquid state. Once the correct refrigerant
charge is determined, all tests shall run until
completion without further modification.
3.5.2.5.1. When charging or adjusting
superheat/subcooling, use all pertinent
instructions contained in the installation
instructions to achieve charging parameters
within the tolerances. However, in the event
of conflicting charging information between
installation instructions, follow the
installation instruction hierarchy listed in
section 3.5.2.4. Conflicting information is
defined as multiple conditions given for
charge adjustment where all conditions
specified cannot be met. In the event of
conflicting information within the same set
of charging instructions (e.g., the installation
instructions shipped with the dedicated
condensing unit), follow the hierarchy in
Table 19 for priority. Unless the installation
instructions specify a different charging
tolerance, the tolerances identified in table
19 of this appendix shall be used.
TABLE 19—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF REFRIGERANT
CONDITIONS
Fixed orifice
Priority
Parameter with installation
instruction target
Tolerance
Parameter with installation
instruction target
Tolerance
1 ........
Superheat ........................................
±2.0 °F ..................
Subcooling .......................................
2 ........
±4.0 psi or ±1.0 °F
High Side Pressure or Saturation
Temperature*.
Superheat ........................................
4 ........
High Side Pressure or Saturation
Temperature*.
Low Side Pressure or Saturation
Temperature*.
Low Side Temperature ....................
10% of the Target Value; No less
than ±0.5 °F, No more than ±2.0
°F
±4.0 psi or
±1.0 °F
±2.0 °F
±2.0 °F ..................
5 ........
6 ........
High Side Temperature ...................
Charge Weight .................................
±2.0 °F ..................
±2.0 oz ..................
Low Side Pressure or Saturation
Temperature *.
Approach Temperature ....................
Charge Weight .................................
±2.0 psi or
±0.8 °F
±1.0 °F
0.5% or 1.0 oz, whichever is greater
3 ........
ddrumheller on DSK120RN23PROD with RULES2
Expansion Valve
±2.0 psi or ±0.8 °F
* Saturation temperature can refer to either bubble or dew point calculated based on a measured pressure, or a coil temperature measurement, as specified by the installation instructions.
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Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
3.5.2.5.2. Dedicated Condensing Unit.
If the Dedicated Condensing Unit includes
a receiver and the subcooling target leaving
the condensing unit provided in installation
instructions cannot be met without fully
filling the receiver, the subcooling target
shall be ignored. Likewise, if the Dedicated
Condensing unit does not include a receiver
and the subcooling target leaving the
condensing unit cannot be met without the
unit cycling off on high pressure, the
subcooling target can be ignored. Also, if no
instructions for charging or for setting
subcooling leaving the condensing unit are
provided in the installation instructions, the
refrigeration system shall be set up with a
charge quantity and/or exit subcooling such
that the unit operates during testing without
shutdown (e.g., on a high-pressure switch)
and operation of the unit is otherwise
consistent with the requirements of the test
procedure of this appendix and the
installation instructions.
3.5.2.5.3. Unit Cooler. Use the shipped
expansion device for testing. Otherwise, use
the expansion device specified in the
installation instructions. If the installation
instructions specify multiple options for the
expansion device, any specified expansion
device may be used. The supplied expansion
device shall be adjusted until either the
superheat target is met, or the device reaches
the end of its adjustable range. In the event
the device reaches the end of its adjustable
range and the super heat target is not met,
test with the adjustment at the end of its
range providing the closest match to the
superheat target, and the test condition
tolerance for super heat target shall be
ignored. The measured superheat is not
subject to a test operating tolerance.
However, if the evaporator exit condition is
used to determine capacity using the DX dual
instrumentation method or the refrigerant
enthalpy method, individual superheat value
measurements may not be equal to or less
than zero. If this occurs, or if the operating
tolerances of measurements affected by
expansion device fluctuation are exceeded,
the expansion device shall be replaced,
operated at an average superheat value higher
than the target, or both, in order to avoid
individual superheat value measurements
less than zero and/or to meet the required
operating tolerances.
3.5.2.5.4. Single-Packaged Unit. Unless
otherwise directed by the installation
instructions, install one or more refrigerant
line pressure gauges during the setup of the
unit, located depending on the parameters
used to verify or set charge, as described in
this section:
3.5.2.5.4.1. Install a pressure gauge in the
liquid line if charging is on the basis of
subcooling, or high side pressure or
corresponding saturation or dew point
temperature.
3.5.2.5.4.2. Install a pressure gauge in the
suction line if charging is on the basis of
superheat, or low side pressure or
corresponding saturation or dew point
temperature. Install this gauge as close to the
evaporator as allowable by the installation
instructions and the physical constraints of
the unit. Use methods for installing pressure
gauge(s) at the required location(s) as
indicated in the installation instructions if
specified.
3.5.2.5.4.3. If the installation instructions
indicate that refrigerant line pressure gauges
should not be installed and the unit fails to
operate due to high-pressure or low-pressure
compressor cut off, then a charging port shall
be installed, and the unit shall be evacuated
of refrigerant and charged to the nameplate
charge.
3.5.2.6 Ducted Units
For systems with ducted evaporator air, or
that can be installed with or without ducted
evaporator air: Connect ductwork on both the
inlet and outlet connections and determine
external static pressure (ESP) as described in
sections 6.4 and 6.5 of ANSI/ASHRAE 37.
Use pressure measurement instrumentation
as described in section 5.3.2 of ANSI/
ASHRAE 37. Test at the fan speed specified
in the installation instructions—if there is
more than one fan speed setting and the
installation instructions do not specify which
speed to use, test at the highest speed.
Conduct tests with the ESP equal to 50% of
the maximum ESP allowed in the installation
instructions, within a tolerance of ¥0.00/
+0.05 inches of water column. If the
installation instructions do not provide the
maximum ESP, the ESP shall be set for
testing such that the air volume rate is 2⁄3 of
the air volume rate measured when the ESP
is 0.00 inches of water column within a
tolerance of ¥0.00/+0.05 inches of water
column.
If testing using either the indoor or outdoor
air enthalpy method to measure the air
volume rate, adjust the airflow measurement
apparatus fan to set the external static
pressure—otherwise, set the external static
pressure by symmetrically restricting the
outlet of the test duct. In case of conflict,
these requirements for setting airflow take
precedence over airflow values specified in
manufacturer installation instructions or
product literature.
3.5.2.7. Two-Speed or Multiple-Speed
Evaporator Fans. Two-Speed or MultipleSpeed evaporator fans shall be considered to
meet the qualifying control requirements of
section C4.2 of Appendix C of AHRI 1250–
2020 for measuring off-cycle fan energy if
they use a fan speed no less than 50% of the
speed used in the maximum capacity tests.
3.5.2.8. Defrost
Use section C10.2.1 of Appendix C of AHRI
1250–2020 for defrost testing. The Test Room
Conditioning Equipment requirement of
section C10.2.1.1 of Appendix C of AHRI
1250–2020 does not apply.
3.5.2.8.1 Adaptive Defrost
When testing to certify compliance to the
energy conservation standards, use NDF = 4,
as instructed in section C10.2.1.7 or C10.2.2.1
of AHRI 1250–2020. When determining the
represented value of the calculated benefit
for the inclusion of adaptive defrost, use NDF
= 2.5, as instructed in section C10.2.1.7 or
C10.2.2.1 of AHRI 1250–2020.
3.5.2.8.2 Hot Gas Defrost
When testing to certify compliance to the
energy conservation standards, remove the
hot gas defrost mechanical components and
disconnect all such components from
electrical power. Test the units as if they are
electric defrost units, but do not conduct the
defrost tests described in section C10.2.1 of
AHRI 1250–2020. Use the defrost heat and
power consumption values as described in
section C10.2.2 of AHRI 1250–2020 for the
AWEF2 calculations.
3.5.2.9 Dedicated condensing units that
are not matched for testing and are not
single-packaged dedicated systems.
The temperature measurement
requirements of sections C3.1.3 and C4.1.3.1
appendix C of AHRI 1250–2020 shall apply
only to the condensing unit exit rather than
to the unit cooler inlet and outlet, and they
shall be applied for two measurements when
using the DX Dual Instrumentation test
method.
3.5.2.10. Single-packaged dedicated
systems
Use the test method in section C9 of
appendix C of AHRI 1250–2020 (including
the applicable provisions of ASHRAE 16–
2016, ASHRAE 23.1–2010, ASHRAE 37–
2009, and ASHRAE 41.6–2014, as referenced
in section C9.1 of AHRI 1250–2020) as the
method of test for single-packaged dedicated
systems, with modifications as described in
this section. Use two test methods listed in
table 20 of this appendix to calculate the net
capacity and power consumption. The test
method listed with a lower ‘‘Hierarchy
Number’’ and that has ‘‘Primary’’ as an
allowable use in table 20 of this appendix
shall be considered the primary measurement
and used as the net capacity.
TABLE 20—SINGLE-PACKAGED METHODS OF TEST AND HIERARCHY
ddrumheller on DSK120RN23PROD with RULES2
Hierarchy number
1
2
3
4
5
6
7
8
...........................................
...........................................
...........................................
...........................................
...........................................
...........................................
...........................................
...........................................
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Method of test
Test hierarchy
Balanced Ambient Indoor Calorimeter ............................
Indoor Air Enthalpy .........................................................
Indoor Room Calorimeter ................................................
Calibrated Box .................................................................
Balanced Ambient Outdoor Calorimeter .........................
Outdoor Air Enthalpy .......................................................
Outdoor Room Calorimeter .............................................
Single-Packaged Refrigerant Enthalpy 1 .........................
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Primary.
Primary or Secondary.
Primary or Secondary.
Primary or Secondary.
Secondary.
Secondary.
Secondary.
Secondary.
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Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
28869
TABLE 20—SINGLE-PACKAGED METHODS OF TEST AND HIERARCHY—Continued
Hierarchy number
Method of test
Test hierarchy
9 ...........................................
Compressor Calibration ..................................................
Secondary.
ddrumheller on DSK120RN23PROD with RULES2
Notes:
1 See description of the single-packaged refrigerant enthalpy method in section 3.5.2.10.1 of this appendix.
3.5.2.10.1 Single-Packaged Refrigerant
Enthalpy Method
The single-packaged refrigerant enthalpy
method shall follow the test procedure of the
DX Calibrated Box method in AHRI 1250–
2020, appendix C, section C8 for refrigerantside measurements with the following
modifications:
3.5.2.10.1.1 Air-side measurements shall
follow the requirements of the primary
single-packaged method listed in table 20 of
this appendix. The air-side measurements
and refrigerant-side measurements shall be
collected over the same intervals.
3.5.2.10.1.2 A preliminary test at Test
Rating Condition A is required using the
primary method prior to any modification
necessary to install the refrigerant-side
measuring instruments. Install surface mount
temperature sensors on the evaporator and
condenser coils at locations not affected by
liquid subcooling or vapor superheat (i.e.,
near the midpoint of the coil at a return
bend), entering and leaving the compressor,
and entering the expansion device. These
temperature sensors shall be included in the
regularly recorded data.
3.5.2.10.1.3 After the preliminary test is
completed, the refrigerant shall be removed
from the equipment and the refrigerant-side
measuring instruments shall be installed. The
equipment shall then be evacuated and
recharged with refrigerant. Once the
equipment is operating at Test Condition A,
the refrigerant charge shall be adjusted until,
as compared to the average values from the
preliminary test, the following conditions are
achieved:
(a) Each on-coil temperature sensor
indicates a reading that is within ±1.0 °F of
the measurement in the initial test,
(b) The temperatures of the refrigerant
entering and leaving the compressor are
within ±4 °F, and
(c) The refrigerant temperature entering the
expansion device is within ±1 °F.
3.5.2.10.1.4 Once these conditions have
been achieved over an interval of at least 10
minutes, refrigerant charging equipment shall
be removed and the official tests shall be
conducted.
3.5.2.10.1.5 The lengths of liquid line to
be added shall be 5 feet maximum, not
including the requisite flow meter. This
maximum length applies to each circuit
separately.
3.5.2.10.1.6 Use section C9.2 of appendix
C of AHRI 1250–2020 for allowable
refrigeration capacity heat balance. Calculate
the single-packaged refrigerant enthalpy
(secondary) method test net capacity
˙ net,secondary as follows: Q
˙ net,secondary =
Q
˙ ref-3.412·E˙Fcomp,on¥Q
˙ sploss
Q
Where:
˙ ref is the gross capacity;
Q
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E˙Fcomp,on is the evaporator compartment oncycle power, including evaporator fan
power; and
˙ sploss is a duct loss calculation applied to the
Q
evaporator compartment of the singlepackaged systems, which is calculated as
indicated in the following equation.
˙ sploss = UAcond × (Tevapside ¥ Tcondside) +
Q
UAamb × (Tevapside ¥ Tamb)
Where:
UAcond and UAamb are, for the condenser/
evaporator partition and the evaporator
compartment walls exposed to ambient air,
respectively, the product of the overall heat
transfer coefficient and surface area of the
unit as manufactured, i.e. without external
insulation that might have been added during
the test. The areas shall be calculated based
on measurements, and the thermal resistance
values shall be based on insulation thickness
and insulation material;
Tevapside is the air temperature in the
evaporator compartment—the measured
evaporator air inlet temperature may be used;
Tcondside is the air temperature in the
condenser compartment—the measured
chamber ambient temperature may be used,
or a measurement may be made using a
temperature sensor placed inside the
condenser box at least 6 inches distant from
any part of the refrigeration system; and
Tamb is the air temperature outside the
single-packaged system.
3.5.2.10.1.7 For multi-circuit singlepackaged systems utilizing the singlepackaged refrigerant enthalpy method, apply
the test method separately for each circuit
and sum the separately-calculated
refrigerant-side gross refrigeration capacities.
3.5.2.10.2 Calibrated Box Test Procedure
3.5.2.10.2.1 Measurements. Refer to
section C3 of AHRI 1250–2020 (including the
applicable provisions of ASHRAE 41.1–2013,
ASHRAE 41.3–2014, and ASHRAE 41.10–
2013, as referenced in section C3 of AHRI
1250–2020) for requirements of air-side and
refrigerant-side measurements.
3.5.2.10.2.2 Apparatus setup for
Calibrated Box Calibration and Test. Refer to
section C5 of AHRI 1250–2020 and section
C8 of AHRI 1250–2020 for specific test setup.
3.5.2.10.2.3 The calibrated box shall be
installed in a temperature-controlled
enclosure in which the temperature can be
maintained at a constant level. When using
the calibrated box method for SinglePackaged Dedicated Systems, the enclosure
air temperature shall be maintained such that
the condenser air entering conditions are as
specified for the test.
3.5.2.10.2. The temperature-controlled
enclosure shall be of a size that will provide
clearances of not less than 18 in at all sides,
top and bottom, except that clearance of any
one surface may be reduced to not less than
5.5 inches.
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3.5.2.10.2.5 The heat leakage of the
calibrated box shall be noted in the test
report.
3.5.2.10.2.6 Refrigerant lines within the
calibrated box shall be well insulated to
avoid appreciable heat loss or gain.
3.5.2.10.2.7 Instruments for measuring
the temperature around the outside of the
calibrated box to represent the enclosure
temperature Ten shall be located at the center
of each wall, ceiling, and floor. Exception: in
the case where a clearance around the
outside of the calibrated box, as indicated in
section 3.5.2.10.2.4 of this appendix, is
reduced to less than 18 inches, the number
of temperature measuring devices on the
outside of that surface shall be increased to
six, which shall be treated as a single
temperature to be averaged with the
temperature of each of the other five surfaces.
The six temperature measuring instruments
shall be located at the center of six
rectangular sections of equal area. If the
refrigeration system is mounted at the
location that would cover the center of the
face on which it is mounted, up to four
temperature measurements shall be used on
that face to represent its temperature. Each
sensor shall be aligned with the center of the
face’s nearest outer edge and centered on the
distance between that edge and the singlepackaged unit (this is illustrated in figure C5
of this section when using surface
temperature sensors), and they shall be
treated as a single temperature to be averaged
with the temperature of each of the other five
surfaces. However, any of these sensors shall
be omitted if either (a) the distance between
the outer edge and the single-packaged unit
is less than one foot or (b) if the sensor
location would be within two feet of any of
the foot square surfaces discussed in section
3.5.2.10.2.8 of this appendix representing a
warm discharge air impingement area. In this
case, the remaining sensors shall be used to
represent the average temperature for the
surface.
3.5.2.10.2.8 One of the following two
approaches shall be used for the box external
temperature measurement. Box calibration
and system capacity measurement shall both
be done using the same one of these
approaches. 1: Air temperature sensors. Each
temperature sensor shall be at a distance of
6 inches from the calibrated box. If the
clearance from a surface of the box (allowed
for one surface only) is less than 12 inches,
the temperature measuring instruments shall
be located midway between the outer wall of
the calibrated box and the adjacent surface.
2: Surface temperature sensors. Surface
temperature sensors shall be mounted on the
calibrated box surfaces to represent the
enclosure temperature, Ten.
3.5.2.10.2.9 Additional surface
temperature sensors may be used to measure
external hot spots during refrigeration system
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04MYR2
testing. If this is done, two temperature
sensors shall be used to measure the average
temperature of the calibrated box surface
covered by the condensing section—they
shall be located centered on equal-area
rectangles comprising the covered calibrated
box surface whose common sides span the
short dimension of this surface. Additional
surface temperature sensors may be used to
measure box surfaces on which warm
condenser discharge air impinges. A pattern
of square surfaces measuring one foot square
shall be mapped out to represent the hot spot
upon which the warm condenser air
impinges. One temperature sensor shall be
used to measure surface temperature at the
center of each square (see figure C5 of this
section). A drawing showing this pattern and
identifying the surface temperature sensors
shall be provided in the test report. The
average surface temperature of the overall
calibrated box outer surface during testing
shall be calculated as follows.
Where:
Ai is the surface area of the ith of the six
calibrated box surfaces;
Ti is the average temperature measured for
the ith surface;
Aj is half of the surface area of the calibrated
box covered by the condensing section;
T’j is the jth of the two temperature
measurements underneath the
condensing section;
T1 is the average temperature of the four or
fewer measurements representing the
temperature of the face on which the
single-packaged system is mounted,
prior to adjustments associated with hot
spots based on measurements Tj and/or
Tk;
Ak is the area of the kth of n 1-square-foot
surfaces used to measure the condenser
discharge impingement area hot spot;
and,
T’’k is the kth of the n temperature
measurements of the condenser
discharge impingement area hot spot.
Figure C5: Illustration of Layout of Surface
Temperature Sensors on Face of Calibrated
Box on which Single-Packaged Dedicated
System is Mounted when Using Section
3.5.2.10.2.7 of Appendix C to this
Part.3.5.2.10.2.10 Heating means inside the
calibrated box shall be shielded or
installed in a manner to avoid radiation to
the Single-Packaged Dedicated System, the
temperature measuring instruments, and to
the walls of the box. The heating means
shall be constructed to avoid stratification
of temperature, and suitable means shall be
provided for distributing the temperature
uniformly.
3.5.2.10.2.11 The average air dry-bulb
temperature in the calibrated box during
Single-Packaged Dedicated System tests and
calibrated box heat leakage tests shall be the
average of eight temperatures measured at the
corners of the box at a distance of 2 inches
to 4 inches from the walls. The instruments
shall be shielded from any cold or warm
surfaces except that they shall not be
shielded from the adjacent walls of the box.
The Single-Packaged Dedicated System
under test shall be mounted such that the
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28871
temperature instruments are not in the direct
air stream from the discharge of the SinglePackaged Dedicated System.
3.5.2.10.2.12 Calibration of the Calibrated
Box. Calibration of the Calibrated Box shall
occur prior to installation of the SinglePackaged Dedicated System. This shall be
done either (a) prior to cutting the opening
needed to install the Single-Packaged
Dedicated System, or (b) with an insulating
panel with the same thickness and thermal
resistance as the box wall installed in the
opening intended for the Single-Packaged
Dedicated System installation. Care shall be
taken to avoid thermal shorts in the location
of the opening either during calibration or
during subsequent installation of the SinglePackaged Dedicated System. A calibration
test shall be made for air movements
comparable to those expected for Single-
Packaged Dedicated System capacity
measurement, i.e., with air volume flow rate
within 10 percent of the air volume flow rate
of the Single-Packaged Dedicated System
evaporator.
3.5.2.10.2.13 The heat input shall be
adjusted to maintain an average box
temperature not less than 25.0 °F above the
test enclosure temperature.
3.5.2.10.2.14 The average dry-bulb
temperature inside the calibrated box shall
not vary more than 1.0 °F over the course of
the calibration test.
3.5.2.10.2.15 A calibration test shall be
the average of 11 consecutive hourly readings
when the box has reached a steady-state
temperature condition.
3.5.2.10.2.16 The box temperature shall
be the average of all readings after a steady-
state temperature condition has been
reached.
3.5.2.10.2.17 The calibrated box has
reached a steady-state temperature condition
when: The average box temperature is not
less than 25 °F above the test enclosure
temperature. Temperature variations do not
exceed 5.0 °F between temperature
measuring stations. Temperatures do not vary
by more than 2 °F at any one temperaturemeasuring station.
3.5.2.10.2.18 Data to be Measured and
Recorded. Refer to Table C5 in section C6.2
of AHRI 1250–2020 for the required data that
need to measured and recorded.
3.5.2.10.2.19 Refrigeration Capacity
Calculation.
The heat leakage coefficient of the
calibrated box is calculated by
For each Dry Rating Condition, calculate
the Net Capacity:
q˙ss = Kcb (Ten¥Tcb) + 3.412 × E˙c
3.5.2.10.3 Detachable single-packaged
systems shall be tested as single-packaged
dedicated refrigeration systems.
3.5.2.11 Variable-Capacity and MultipleCapacity Dedicated Condensing Refrigeration
Systems
3.5.2.11.1 Manufacturer-Provided
Equipment Overrides
Where needed, the manufacturer must
provide a means for overriding the controls
of the test unit so that the compressor(s)
operates at the specified speed or capacity
and the indoor blower operates at the speed
consistent with the compressor operating
level as would occur without override.
3.5.2.11.2 Compressor Operating Levels
For variable-capacity and multiplecapacity compressor systems, the minimum
capacity for testing shall be the minimum
capacity that the system control would
operate the compressor in normal operation.
Likewise, the maximum capacity for testing
shall be the maximum capacity that the
system control would operate the compressor
in normal operation. For variable-speed
compressor systems, the intermediate speed
for testing shall be the average of the
minimum and maximum speeds. For digital
compressor systems, the intermediate duty
cycle shall be the average of the minimum
and maximum duty cycles. For multiplecapacity compressor systems with three
capacity levels, the intermediate operating
level for testing shall be the middle capacity
level. For multiple-capacity compressor
systems with more than three capacity levels,
the intermediate operating level for testing
shall be the level whose displacement ratio
is closest to the average of the maximum and
minimum displacement ratios.
3.5.2.11.3 Refrigeration Systems with
Digital Compressor(s)
Use the test methods described in section
3.5.2.10.1 of this appendix as the secondary
method of test for refrigeration systems with
digital compressor(s) with modifications as
described in this section. The Test Operating
tolerance for refrigerant mass flow rate and
suction pressure in Table 2 of AHRI 1250–
2020 shall be ignored. Temperature and
pressure measurements used to calculate
shall be recorded at a frequency of once per
second or faster and based on average values
measured over the 30-minute test period.
3.5.2.11.3.1 For Matched pair (not
including single-packaged systems) and
Dedicated Condensing Unit refrigeration
systems, the preliminary test in sections
3.5.2.10.1.2 and 3.5.2.10.1.3 of this appendix
is not required. The liquid line and suction
line shall be 25 feet ± 3 inches, not including
the requisite flow meters. Also, the term in
the equation to calculate net capacity shall be
set equal to zero.
3.5.2.11.3.2 For Dedicated Condensing
Unit refrigeration systems, the primary
capacity measurement method shall be
balanced ambient outdoor calorimeter,
outdoor air enthalpy, or outdoor room
calorimeter.
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Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules and Regulations
]]>Agencies
[Federal Register Volume 88, Number 86 (Thursday, May 4, 2023)]
[Rules and Regulations]
[Pages 28780-28871]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-08128]
[[Page 28779]]
Vol. 88
Thursday,
No. 86
May 4, 2023
Part III
Department of Energy
-----------------------------------------------------------------------
10 CFR Parts 429 and 431
Energy Conservation Program: Test Procedures for Walk-In Coolers and
Walk-In Freezers; Final Rule
Federal Register / Vol. 88, No. 86 / Thursday, May 4, 2023 / Rules
and Regulations
[[Page 28780]]
-----------------------------------------------------------------------
DEPARTMENT OF ENERGY
10 CFR Parts 429 and 431
[EERE-2017-BT-TP-0010]
RIN 1904-AD78
Energy Conservation Program: Test Procedures for Walk-In Coolers
and Walk-In Freezers
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The U.S. Department of Energy (DOE) is amending the test
procedures for walk-in coolers and walk-in freezers to harmonize with
updated industry standards, revise certain definitions, revise the test
methods to more accurately represent field energy use, and to
accommodate a wider range of walk-in cooler and walk-in freezer
component equipment designs.
DATES: The effective date of this rule is June 5, 2023. The amendments
will be mandatory for product testing starting October 31, 2023.
Manufacturers will be required to use the amended test procedures until
the compliance date of any final rule establishing amended energy
conservation standards based on the newly established test procedures.
At such time, manufacturers will be required to begin using the newly
established test procedures.
The incorporation by reference of certain materials listed in the
rule is approved by the Director of the Federal Register on June 5,
2023. The incorporation by reference of certain other material listed
in the rule was approved by the Director of the Federal Register on
January 27, 2017.
ADDRESSES: The docket, which includes Federal Register notices, public
meeting attendee lists and transcripts, comments, and other supporting
documents/materials, is available for review at www.regulations.gov.
All documents in the docket are listed in the www.regulations.gov
index. However, not all documents listed in the index may be publicly
available, such as those containing information that is exempt from
public disclosure.
A link to the docket web page can be found at www.regulations.gov/docket/EERE-2017-BT-TP-0010. The docket web page contains instructions
on how to access all documents, including public comments, in the
docket.
For further information on how to review the docket contact the
Appliance and Equipment Standards Program staff at (202) 287-1445 or by
email: [email protected].
FOR FURTHER INFORMATION CONTACT: Ms. Catherine Rivest, U.S. Department
of Energy, Office of Energy Efficiency and Renewable Energy, Building
Technologies Office, EE-5B, 1000 Independence Avenue SW, Washington, DC
20585-0121. Telephone: (202) 586-7335. Email:
[email protected].
Mr. Matthew Schneider, U.S. Department of Energy, Office of the
General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC
20585-0121. Telephone: (240) 597-6265. Email:
[email protected].
SUPPLEMENTARY INFORMATION: DOE maintains a previously approved
incorporation by reference and incorporates by reference the following
industry standards into part 431:
AHRI Standard 1250-2020, ``2020 Standard for Performance Rating of
Walk-in Coolers and Freezers.''
Copies of AHRI 1250-2020 can be obtained from the Air-Conditioning,
Heating, and Refrigeration Institute, 2111 Wilson Blvd., Suite 400,
Arlington, VA 22201 or at www.ahrinet.org.
ANSI/ASHRAE 16-2016, ``Method of Testing for Rating Room Air
Conditioners, Packaged Terminal Air Conditioners, and Packaged Terminal
Heat Pumps for Cooling and Heating Capacity''.
ANSI/ASHRAE 23.1-2010, ``Methods of Testing for Rating the
Performance of Positive Displacement Refrigerant Compressors and
Condensing Units that Operate at Subcritical Temperatures of the
Refrigerant''.
ANSI/ASHRAE 37-2009, ``Methods of Testing for Rating Electrically
Driven Unitary Air-Conditioning and Heat-Pump Equipment''.
ANSI/ASHRAE 41.1-2013, ``Standard Method for Temperature
Measurement''.
ANSI/ASHRAE 41.3-2014, ``Standard Methods for Pressure
Measurement''.
ANSI/ASHRAE 41.6-2014, ``Standard Method for Humidity
Measurement''.
ANSI/ASHRAE 41.10-2013, ``Standard Methods for Refrigerant Mass
Flow Measurement Using Flowmeters''.
Copies of ANSI/ASHRAE 16-2016, ANSI/ASHRAE 23.1-2010, ANSI/ASHRAE
37-2009, ANSI/ASHRAE 41.1-2013, ANSI/ASHRAE 41.3-2014, ANSI/ASHRAE
41.6-2014, and ANSI/ASHRAE 41.10-2013, can be obtained from the
American Society of Heating, Refrigerating and Air-Conditioning
Engineers, 180 Technology Parkway NW, Peachtree Corners, GA 30092, or
at www.ashrae.org.
ASTM C518-17, ``Standard Test Method for Steady-State Thermal
Transmission Properties by Means of the Heat Flow Meter Apparatus''.
ASTM C1199-14, ``Standard Test Method for Measuring the Steady-
State Thermal Transmittance of Fenestration Systems Using Hot Box
Methods.''
Copies of ASTM C518-17 and ASTM C1199-14 can be obtained from ASTM
International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken,
PA 19428-2959, or at www.astm.org.
NFRC 102-2020 [E0A0], ``Procedure for Measuring the Steady-State
Thermal Transmittance of Fenestration Systems''
Copies of NFRC 102-2020 can be obtained from the National
Fenestration Rating Council, 6305 Ivy Lane, Suite 140, Greenbelt, MD
20770, or at www.nfrc.org.
See section IV.N of this document for a further discussion of these
standards.
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope and Definitions
1. Scope
2. Definitions
B. Updates to Industry Standards
1. Industry Standards for Determining Thermal Transmittance (U-
factor)
2. Industry Standard for Determining R-Value
3. Industry Standards for Determining AWEF
C. Amendments to Appendix A for Doors
1. Reference to NFRC 102-2020 in Place of NFRC 100-2010 and
Alternative Efficiency Determination Methods for Doors
2. Additional Definitions
3. Electrical Door Components
4. Percent Time Off Values
5. Energy Efficiency Ratio Values
6. Air Infiltration Reduction
D. Amendments to Appendix A for Display Panels
E. Amendments to the Appendix B for Panels and Non-Display Doors
1. 24-Hour Testing Window
2. Total Insulation and Test Specimen Thickness
3. Parallelism and Flatness
4. Insulation Aging
5. Overall Thermal Transmittance of Non-Display Panels
F. Amendments to Appendix C for Refrigeration Systems
1. Refrigeration Test Room Conditioning
2. Temperature Measurement Requirements
3. Hierarchy of Installation Instruction and Specified
Refrigerant Conditions for Refrigerant Charging and Setting
Refrigerant Conditions
4. Subcooling Requirement for Mass Flow Meters
5. Instrument Accuracy and Test Tolerances
6. CO2 Unit Coolers
7. High-Temperature Unit Coolers
[[Page 28781]]
G. Establishing Appendix C1 for Refrigeration Systems
1. Off-Cycle Power Consumption
2. Single-Packaged Dedicated Systems
3. Detachable Single-Packaged Dedicated Systems
4. Attached Split Systems
5. Systems for High-Temperature Freezer Applications
6. Systems for High-Temperature Applications
7. Variable-, Two-, and Multiple-Capacity Systems
8. Defrost
9. Refrigerant Glide
10. Refrigerant Temperature and Pressure Instrumentation
Locations
11. Updates to Default Values for Unit Cooler Parameters
12. Calculations and Rounding
H. Alternative Efficiency Determination Methods for
Refrigeration Systems
I. Sampling Plan for Enforcement Testing
J. Organizational Changes
K. Test Procedure Costs and Impact
1. Doors
2. Panels
3. Refrigeration Systems
L. Effective and Compliance Dates
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866 and 13563
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
M. Congressional Notification
N. Description of Materials Incorporated by Reference
V. Approval of the Office of the Secretary
I. Authority and Background
Walk-in coolers and walk-in freezers (collectively ``WICFs'' or
``walk-ins'') are included in the list of ``covered equipment'' for
which the U.S. Department of Energy (DOE) is authorized to establish
and amend energy conservation standards and test procedures. (42 U.S.C.
6311(1)(G)) DOE's energy conservation standards and test procedures for
WICFs are currently prescribed at subpart R of part 431 of title 10 of
the Code of Federal Regulations (CFR). The following sections discuss
DOE's authority to establish test procedures for WICFs and relevant
background information regarding DOE's consideration of test procedures
for this equipment.
A. Authority
The Energy Policy and Conservation Act, Public Law 94-163, as
amended (``EPCA''),\1\ authorizes DOE to regulate the energy efficiency
of a number of consumer products and certain industrial equipment. (42
U.S.C. 6291-6317) Title III, Part C of EPCA \2\ established the Energy
Conservation Program for Certain Industrial Equipment, which sets forth
a variety of provisions designed to improve energy efficiency. This
equipment includes WICFs, the subject of this document. (42 U.S.C.
6311(1)(G))
---------------------------------------------------------------------------
\1\ All references to EPCA in this document refer to the statute
as amended through the Energy Act of 2020, Public Law 116-260 (Dec.
27, 2020), which reflect the last statutory amendments that impact
Parts A and A-1 of EPCA.
\2\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
The energy conservation program under EPCA consists essentially of
four parts: (1) testing, (2) labeling, (3) Federal energy conservation
standards, and (4) certification and enforcement procedures. Relevant
provisions of EPCA include definitions (42 U.S.C. 6311), test
procedures (42 U.S.C. 6314), labeling provisions (42 U.S.C. 6315),
energy conservation standards (42 U.S.C. 6313), and the authority to
require information and reports from manufacturers (42 U.S.C. 6316).
The Federal testing requirements consist of test procedures that
manufacturers of covered equipment must use as the basis for: (1)
certifying to DOE that their equipment complies with the applicable
energy conservation standards adopted pursuant to EPCA (42 U.S.C.
6316(a); 42 U.S.C. 6295(s)), and (2) making other representations about
the efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE
must use these test procedures to determine whether the equipment
complies with relevant standards promulgated under EPCA. (42 U.S.C.
6316(a); 42 U.S.C. 6295(s))
Federal energy efficiency requirements for covered equipment
established under EPCA generally supersede State laws and regulations
concerning energy conservation testing, labeling, and standards. (42
U.S.C. 6316(a) and 42 U.S.C. 6316(b); 42 U.S.C. 6297) DOE may, however,
grant waivers of Federal preemption for particular State laws or
regulations, in accordance with the procedures and other provisions of
EPCA. (42 U.S.C. 6316(b)(2)(D))
Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered equipment. EPCA requires that any test procedures prescribed or
amended under this section must be reasonably designed to produce test
results that reflect energy efficiency, energy use, or estimated annual
operating cost of a given type of covered equipment during a
representative average use cycle (as determined by the Secretary) and
requires that test procedures not be unduly burdensome to conduct. (42
U.S.C. 6314(a)(2))
EPCA also requires that, at least once every 7 years, DOE evaluate
test procedures for each type of covered equipment, including WICFs, to
determine whether amended test procedures would more accurately or
fully comply with the requirements for the test procedures to not be
unduly burdensome to conduct and be reasonably designed to produce test
results that reflect energy efficiency, energy use, and estimated
operating costs during a representative average use cycle. (42 U.S.C.
6314(a)(1)) DOE considers this rulemaking to be in satisfaction of the
7-year review requirement specified in EPCA.
In addition, if the Secretary determines that a test procedure
amendment is warranted, the Secretary must publish proposed test
procedures in the Federal Register, and afford interested persons an
opportunity (of not less than 45 days duration) to present oral and
written data, views, and arguments on the proposed test procedures. (42
U.S.C. 6314(b)) If DOE determines that test procedure revisions are not
appropriate, DOE must publish its determination not to amend the test
procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
B. Background
For measuring walk-in energy use, DOE has established separate test
procedures for the principal components that may comprise a walk-in
(i.e., doors, panels, and refrigeration systems), with separate test
metrics for each component. (10 CFR 431.304(b)) For walk-in doors and
display panels, the efficiency metric is daily energy consumption,
measured in kilowatt-hours per day (kWh/day), which accounts for the
thermal conduction through the door or display panel and the direct and
indirect electricity use of any electrical components associated with
the door. See 10 CFR 431.304(b)(1)-(2) and 10 CFR part 431, subpart R,
appendix A, ``Uniform Test Method for the Measurement of Energy
Consumption of the Components of Envelopes of Walk-in Coolers and Walk-
in Freezers'' (appendix A). The thermal transmittance through the door,
which inputs into the calculation of thermal
[[Page 28782]]
conduction, is determined using National Fenestration Rating Council
(NFRC) 100-2010, ``Procedure for Determining Fenestration U-factors''
(NFRC 100-2010), which is incorporated by reference at 10 CFR 431.303.
For walk-in non-display panels and non-display doors, in the final
rule published on April 15, 2011, DOE codified in the CFR the standards
established in EPCA based on the R-value metric,\3\ expressed in units
of (h-ft\2\-[deg]F/Btu),\4\ which is calculated as the thickness of the
panel in inches (in.) divided by the K-factor.\5\ See 10 CFR
431.304(b)(3) and 10 CFR part 431, subpart R, appendix B, ``Uniform
Test Method for the Measurement of R-Value for Envelope Components of
Walk-in Coolers and Walk-in Freezers'' (appendix B). (See also 42
U.S.C. 6314(a)(9)(A)) The K-factor is calculated based on ASTM
International (ASTM) C518, ``Standard Test Method for Steady-State
Thermal Transmission Properties by Means of the Heat Flow Meter
Apparatus'' (ASTM C518), which is incorporated by reference at 10 CFR
431.303. Id.
---------------------------------------------------------------------------
\3\ The R-value is the thermal resistance, or the capacity of an
insulated material to resist heat flow. See section 3.3.3 of ASTM
C518. See 42 U.S.C. 6313(f)(1)(C) for the EPCA R-value requirements
for non-display panels and doors.
\4\ These symbols represent the following units of measurement--
h: hour; ft\2\: square foot; [deg]F: degrees Fahrenheit; Btu:
British thermal unit.
\5\ The K-factor represents the thermal conductivity of a
material, or its ability to conduct heat, in units of Btu-in/(h-
ft\2\-[deg]F). See section 3.3.1 of ASTM C518.
---------------------------------------------------------------------------
For walk-in refrigeration systems, the efficiency metric is the
annual walk-in energy factor (``AWEF''), which is the ratio of the
total heat, not including the heat generated by the operation of
refrigeration systems, removed, in Btu, from a walk-in box during a
one-year period of usage for refrigeration to the total energy input of
refrigeration systems, in watt-hours, during the same period. AWEF is
determined by conducting the test procedure set forth in American
National Standards Institute (ANSI)/Air-Conditioning, Heating, and
Refrigeration Institute (AHRI) Standard 1250 (I-P), ``2009 Standard for
Performance Rating of Walk-in Coolers and Freezers'' (AHRI 1250-2009),
which is incorporated by reference in 10 CFR 431.303 with certain
adjustments specified in the CFR. See 10 CFR 431.304(b)(4) and 10 CFR
part 431, subpart R, appendix C, ``Uniform Test Method for the
Measurement of Net Capacity and AWEF of Walk-in Cooler and Walk-in
Freezer Refrigeration Systems'' (appendix C). A manufacturer may also
determine AWEF using an alternative efficiency determination method
(AEDM). 10 CFR 429.53(a)(2)(iii). An AEDM enables a manufacturer to
utilize computer-based or mathematical models for purposes of
determining an equipment's energy use or energy efficiency performance
in lieu of testing, provided certain prerequisites have been met. 10
CFR 429.70(f).
On August 5, 2015, DOE published its intention to establish a
working group under the Appliance Standards and Rulemaking Federal
Advisory Committee (ASRAC) to negotiate energy conservation standards
to replace the standards established in the final rule published on
June 3, 2014 (79 FR 32050, ``June 2014 ECS Final Rule''). 80 FR 46521.
The established working group (ASRAC Working Group) assembled its
recommendations into a term sheet \6\ (Docket No. EERE-2015-BT-STD-
0016, No. 56) that was presented to and approved by ASRAC on December
18, 2015 (ASRAC Term Sheet).
---------------------------------------------------------------------------
\6\ Appliance Standards and Rulemaking Federal Advisory
Committee Refrigeration Systems Walk-in Coolers and Freezers Term
Sheet, available at www.regulations.gov/document/EERE-2015-BT-STD-
0016-0056.
---------------------------------------------------------------------------
The ASRAC Term Sheet provided recommendations for energy
conservation standards to replace standards vacated by the United
States Court of Appeals for the Fifth Circuit in a controlling order
issued August 10, 2015. It also included recommendations regarding
definitions for a number of terms related to the WICF regulations, as
well as recommendations to amend the test procedure that the ASRAC
Working Group viewed as necessary to properly implement the energy
conservation standards recommendations. Consequently, in 2016 DOE
initiated both an energy conservation standards rulemaking and a test
procedure rulemaking to implement these recommendations. The ASRAC Term
Sheet also included recommendations for future amendments to the test
procedures intended to make DOE's test procedures more fully
representative of walk-in energy use.
On December 28, 2016, DOE published a final rule amending the WICF
test procedures (``December 2016 Final Rule''), consistent with the
ASRAC Term Sheet recommendations and including provisions to facilitate
implementation of energy conservation standards for walk-in components.
81 FR 95758.
In 2020, AHRI published an updated industry test standard for walk-
in refrigeration systems, ``2020 Standard for Performance Rating of
Walk-in Coolers and Freezers,'' (AHRI 1250-2020) updating the existing
AHRI standard ``AHRI 1250P (I-P)-2009.'' This new test procedure
included updated calculations for the determination of default values
for equipment with electric defrost and hot gas defrost. DOE published
a final rule for hot gas defrost unit coolers on March 26, 2021 (March
2021 Final Rule), that amended the test procedure to rate hot gas
defrost unit coolers using the modified default values for energy use
and heat load contributions in AHRI 1250-2020. These amendments ensure
that ratings for hot gas defrost unit coolers are consistent with those
of electric defrost unit coolers. 86 FR 16027.
Under 10 CFR 431.401, any interested person may submit a petition
for waiver from DOE's test procedure requirements. DOE will grant a
waiver from the test procedure requirements if DOE determines either
the basic model for which the waiver was requested contains a design
characteristic that prevents testing of the basic model according to
the prescribed test procedures, or the prescribed test procedures
evaluate the basic model in a manner so unrepresentative of its true
energy consumption characteristics as to provide materially inaccurate
comparative data. 10 CFR 431.401(f)(2). DOE may grant the waiver
subject to conditions, including adherence to alternate test procedures
specified by DOE. Id. DOE has granted interim waivers and/or waivers to
the manufacturers listed in Table I.1.
Table I.1--Manufacturers Who Received a Test Procedure Waiver/Interim Waiver From DOE
----------------------------------------------------------------------------------------------------------------
Waiver from
Manufacturer Subject Case No. appendix
----------------------------------------------------------------------------------------------------------------
Jamison Door Company......................... Percent Time Off (PTO) for Door 2017-009 A
Motors.
HH Technologies.............................. PTO for Door Motors............. 2018-001 A
[[Page 28783]]
Senneca Holdings............................. PTO for Door Motors............. 2020-002 A
Hercules..................................... PTO for Door Motors............. 2020-013 A
Heat Transfer Products Group, LLC (HTPG)..... CO2 Unit Coolers................ 2020-009 C
Hussmann Corporation (Hussmann).............. CO2 Unit Coolers................ 2020-010 C
KeepRite Refrigeration, Inc. (KeepRite)...... CO2 Unit Coolers................ 2020-014 C
RefPlus, Inc................................. CO2 Unit Coolers................ 2021-006 C
Refrigerated Solutions Group (RSG)........... Multi-Circuit Single-Package 2022-004 C
Dedicated Systems.
Store It Cold................................ Single-Packaged Dedicated 2018-002 C
Systems.
CellarPro.................................... Wine Cellar Refrigeration 2019-009 C
Systems.
Air Innovations.............................. Wine Cellar Refrigeration 2019-010 C
Systems.
Vinotheque................................... Wine Cellar Refrigeration 2019-011 C
Systems.
Vinotemp..................................... Wine Cellar Refrigeration 2020-005 C
Systems.
LRC Coil Company (LRC Coil).................. Wine Cellar Refrigeration 2020-024 C
Systems.
----------------------------------------------------------------------------------------------------------------
On June 17, 2021, DOE published a request for information (RFI) to
initiate a test procedure rulemaking for walk-ins (June 2021 RFI). 86
FR 32332. DOE published a notice of proposed rulemaking (NOPR) on April
21, 2022 (April 2022 NOPR), responding to comments received in response
to the June 2021 RFI and presenting DOE's proposals to amend the WICFs
test procedure--including amendments to eliminate the need for existing
test procedure waivers--and establish a new test procedure at 10 CFR
part 431, subpart R, appendix C1 (appendix C1), that would establish a
new energy efficiency metric, AWEF2. 87 FR 23920. DOE held a public
meeting related to the April 2022 NOPR on May 9, 2022.
DOE received comments in response to the April 2022 NOPR from the
interested parties listed in Table I.2.
Table I.2--List of Commenters With Written Submissions in Response to the April 2022 NOPR
----------------------------------------------------------------------------------------------------------------
Reference in this Final Comment No. in
Commenter(s) Rule the docket Commenter type
----------------------------------------------------------------------------------------------------------------
Air-Conditioning, Heating, & AHRI \7\.................. 30 Trade Association.
Refrigeration Institute.
Air-Conditioning, Heating, & AHRI-Wine \8\............. 30 Trade Association.
Refrigeration Institute.
Anthony International................... Anthony................... 31 Manufacturer.
Appliance Standards Awareness Project, Efficiency Advocates...... 37 Efficiency Organizations.
American Council for an Energy-
Efficient Economy, Natural Resources
Defense Council, Northwest Energy
Efficiency Alliance.
Bally Refrigerated Boxes, Inc........... Bally..................... 40 Manufacturer.
Heat Transfer Products Group, LLC....... HTPG...................... 32 Manufacturer.
Hussmann Corporation.................... Hussmann.................. 34, 38 Manufacturer.
KeepRite Refrigeration, Inc............. KeepRite.................. 36 Manufacturer.
Lennox International Inc................ Lennox.................... 35 Manufacturer.
National Refrigeration & Air National Refrigeration.... 39 Manufacturer.
Conditioning Canada Corp.
North American Association of Food NAFEM..................... 33 Trade Association.
Equipment.
Pacific Gas and Electric Company, San CA IOUs................... 42 Utility Association.
Diego Gas & Electric, and Southern
California Edison; collectively, the
California Investor-Owned Utilities.
Refrigerated Solutions Group............ RSG....................... 41 Manufacturer.
Senneca Holdings........................ Senneca................... 26 Manufacturer.
----------------------------------------------------------------------------------------------------------------
A parenthetical reference at the end of a comment quotation or
paraphrase provides the location of the item in the public record.\9\
To the extent that interested parties have provided written comments
that are substantively consistent with any oral comments provided
during the May 2022 public meeting, DOE cites the written comments
throughout this final rule.
---------------------------------------------------------------------------
\7\ AHRI submitted two comment documents to the docket. The
first document in the docket includes AHRI's comments for
traditional walk-in manufacturers (i.e., medium- and low-temperature
walk-in components). The associated file name in the docket is: AHRI
Comments WICF NOPR EERE-2017-BT-TP-0010. These comments are
referenced in this document as ``AHRI'' comments.
\8\ AHRI submitted two comment documents to the docket. The
second document in the docket includes AHRI's comments supporting
wine cellar manufacturers (i.e., high-temperature walk-in
refrigeration systems). The associated file name in the docket is:
Comments WICF NOPR EERE-2017-BT-TP-0010 Wine. These comments are
referenced in this document as ``AHRI-Wine'' comments.
\9\ The parenthetical reference provides a reference for
information located in the docket of DOE's rulemaking to develop
test procedures for walk-ins (Docket No. EERE-2017-BT-TP-0010,
maintained at www.regulations.gov). The references are arranged as
follows: (commenter name, comment docket ID number, page of that
document).
---------------------------------------------------------------------------
In response to the April 2022 NOPR, NAFEM commented that while the
April 2022 NOPR was not inconsistent with DOE's Process Rule,\10\ NAFEM
supports the U.S. Small Business Administration Office of Advocacy
request \11\ that DOE reopen public comment on the 2021 Process Rule
and
[[Page 28784]]
concurrent proposed rulemaking.\12\ (NAFEM, No. 33 at p. 2) The request
referenced by NAFEM specifically refers to a National Academies of
Sciences (``NAS'') report entitled ``Review of Methods Used by the U.S.
Department of Energy in Setting Appliance and Equipment Standards.''
Given that the recommendations in the NAS report pertain to the
processes by which DOE analyzes energy conservation standards, DOE will
consider this comment in a separate rulemaking that includes all
product categories.
---------------------------------------------------------------------------
\10\ The term ``Process Rule'' refers to DOE's Procedures,
Interpretations, and Policies for Consideration of New or Revised
Energy Conservation Standards and Test Procedures for Consumer
Products and Certain Commercial/Industrial Equipment at 10 CFR part
430, subpart C, appendix A.
\11\ The U.S. Small Business Administration Office of Advocacy
request is available at cdn.advocacy.sba.gov/wp-content/uploads/2022/05/13104422/Comment-Letter-DOE-Process-Rule-Letter_5-13-22.pdf.
\12\ DOE published a NOPR and request for comment on July 7,
2021, proposing changes to the Process Rule. 86 FR 35668.
---------------------------------------------------------------------------
II. Synopsis of the Final Rule
In this final rule, DOE is expanding the scope of its walk-in
coolers and freezers test procedure to include carbon dioxide
(CO2) unit coolers, multi-circuit single-packaged dedicated
systems, and ducted fan coil units. DOE has also determined that
liquid-cooled refrigeration systems are within the scope of DOE
coverage authority for walk-ins but is not adding an applicable test
procedure at this time.
In this final rule, DOE is amending the definitions of walk-in
cooler and walk-in freezer, door, door surface area, and single-
packaged dedicated systems. DOE is also adding new definitions for door
leaf, hinged vertical door, non-display door, roll-up door, sliding
door, high-temperature refrigeration systems, ducted fan coil units,
multi-circuit single-packaged dedicated systems, ducted multi-circuit
single-packaged dedicated systems, attached split systems, detachable
single-packaged dedicated systems, and CO2 unit coolers.
In this final rule, DOE is revising appendix A as follows: (1)
incorporate by reference NFRC 102-2020 as the applicable test procedure
to determine door ``U-factor'' in place of NFRC 100-2010; \13\ (2)
provide further detail on and distinguish the area to be used for
calculating a thermal load from U-factor and determining compliance
with standards; (3) establish a percent time off (``PTO'') specific to
door motors; and (4) reorganize appendix A so it is easier to follow.
---------------------------------------------------------------------------
\13\ As discussed further in section III.C.1.b of this final
rule, DOE is also adopting AEDM provisions for doors in 10 CFR
429.53 to allow calculation of door energy use representations.
---------------------------------------------------------------------------
Additionally, DOE is modifying appendix B to improve test
representativeness and repeatability. Specifically, DOE is revising
appendix B as follows: (1) reference the updated industry standard ASTM
C518-17; (2) include more detailed provisions for determining measuring
insulation thickness and test specimen thickness; (3) provide
additional specifications for determining parallelism and flatness of a
test specimen; and (4) reorganize appendix B as a step-by-step
procedure to improve readability.
DOE is also including walk-in doors and walk-in panels in the list
of covered equipment in the same sampling plan for enforcement testing
that is used for walk-in refrigeration systems. (See 10 CFR
429.110(e)(2))
In this final rule, DOE is making two sets of changes to the
refrigeration system test procedure. One set of changes is grouped into
revisions to appendix C, and the other set of changes is included in a
new appendix C1. DOE has determined that the changes to appendix C will
not affect AWEF ratings and therefore will not require any retesting or
recertification. These changes will be required starting 180 days after
the test procedure final rule is published. DOE is also establishing a
new metric, AWEF2, in the new appendix C1, which will require retesting
and recertification. Use of appendix C1 will not be required until the
compliance date of amended energy conservation standards for WICFs that
DOE may ultimately adopt as part of a separate rulemaking.
DOE is revising appendix C, as follows:
(1) Specify refrigeration test room conditions.
(2) Provide for a temperature probe exception for small diameter
refrigerant lines.
(3) Incorporate a test setup hierarchy of installation instructions
for laboratories to follow when setting up a unit for test.
(4) Allow active cooling of the liquid line in order to achieve the
required 3 [deg]F subcooling at a refrigerant mass flow meter.
(5) Modify instrument accuracy and test tolerances.
(6) Address current test procedure waivers for CO2 unit
coolers tested alone and high-temperature unit coolers tested alone by
incorporating amendments appropriate for this equipment.
The new appendix C1 includes these changes to appendix C, as well
as the following additional changes:
(1) Adopt AHRI 1250-2020.
(2) Provide for testing single-packaged dedicated systems,
detachable single-packaged dedicated systems; attached split systems;
CO2, variable-, two-, and multiple-capacity dedicated
condensing units; indoor variable-, two-, and multiple-capacity matched
pairs; matched refrigeration systems for high-temperature applications;
and multi-circuit single-packaged dedicated systems.
(3) Add a single-packaged dedicated system refrigerant enthalpy
test procedure.
(4) Add a new energy efficiency metric, AWEF2, to reflect the
changes in the test procedure that would result in a significant change
to energy use values compared to the AWEF metric in appendix C.
Table II.1 summarizes the current DOE test procedure, DOE's changes
to the test procedure, the attribution for each proposed change, and
the relevant test procedure appendix.
Table II.1--Summary of Changes in Test Procedure Relative to Current Test Procedure
----------------------------------------------------------------------------------------------------------------
DOE test procedure Amended test Relevant
WICF component(s) prior to amendment procedure Attribution appendix
----------------------------------------------------------------------------------------------------------------
Doors and Display Panels.......... Incorporates by Incorporates by Reduce test burden.. A
reference NFRC 100- reference NFRC 102-
2010 for 2020 for
determining U- determining U-
factor as part of factor and allows
determining energy AEDMs to be used
consumption. for determining
energy consumption.
Doors and Display Panels.......... Uses surface area of Requires that area Improve A
the door or display of the aperture or representative
panel external to surface area used values.
the walk-in to to determine U-
convert U-factor factor be used to
into a conduction convert U-factor
load. into a conduction
load.
[[Page 28785]]
Doors............................. Uses a PTO value of Establishes a PTO Improve A
25 percent for door value of 97 percent representative
motors (as they are specific to door values and address
considered ``other motors. inconsistent values
electricity- across waivers
consuming granted.
devices'').
Non-display Doors and Panels...... Incorporates by Incorporates by Update applicable B
reference ASTM C518- reference ASTM C518- industry test
04. 17. procedures.
Non-display Doors and Panels...... Does not include Includes detailed Ensure test B
detailed provisions provisions for repeatability.
for determining and determining and
measuring total measuring total
insulation insulation
thickness and test thickness and test
specimen thickness. specimen thickness.
Non-display Doors and Panels...... Requires that the Provides Ensure test B
test specimen meet specifications for repeatability.
a parallelism and determining
flatness tolerance parallelism and
of 0.03 flatness of the
inches but provides test specimen.
no guidance on
measurement.
Refrigeration Systems............. Does not include Includes guidance on Ensure test C
guidance on test test room repeatability.
room conditioning. conditioning.
Refrigeration Systems............. Does not include an Includes an Reduce test burden.. C
allowance for allowance for
measuring measuring
refrigerant refrigerant
temperatures with temperatures with
surface-mounted surface-mounted
measuring measuring
instruments. instruments for
small diameter
tubes.
Refrigeration Systems............. Does not include Includes guidance Ensure test C
guidance for unit for unit charging repeatability.
charging or a setup and a setup
condition hierarchy. condition hierarchy.
Refrigeration Systems............. Does not include Includes provisions Improve C
provisions for for testing CO2 representative
testing CO2 unit unit coolers. values.
coolers.
Refrigeration Systems............. Does not include Includes provisions Improve C
provisions for for testing high- representative
testing high- temperature unit values.
temperature unit coolers alone.
coolers alone.
Refrigeration Systems............. Incorporates by Incorporates by Update applicable C1
reference AHRI 1250- reference AHRI 1250- industry test
2009, ASHRAE 23.1- 2020, ASHRAE 37- procedures.
2010, and AHRI 420- 2009, and ASHRAE 16-
2008. 2016.
Refrigeration Systems............. Tests single- Includes multiple Improve C1
packaged dedicated methods for testing representative
systems using the single-packaged values.
refrigerant dedicated systems.
enthalpy method for
matched pairs.
Refrigeration Systems............. Does not include Includes provisions Improve C1
provisions for for testing representative
testing attached attached split values.
split systems or systems or
detachable single- detachable single-
packaged dedicated packaged dedicated
systems. systems.
Refrigeration Systems............. Does not include Includes provisions Improve C1
provisions for for testing multi- representative
testing multi- circuit single- values.
circuit single- packaged dedicated
packaged dedicated systems.
systems.
Refrigeration Systems............. Does not include Includes provisions Improve C1
provisions for for testing ducted representative
testing ducted fan fan coil units. values.
coil units.
Refrigeration Systems............. Does not include Includes provisions Improve C1
provisions for for testing high- representative
testing high- temperature matched- values.
temperature matched- pair and single-
pair and single- packaged dedicated
packaged dedicated systems.
systems.
Refrigeration Systems............. Does not include Includes provisions Improve C1
provisions for for testing of representative
testing of variable- variable, two-, and values.
and multiple- multiple-capacity
capacity dedicated dedicated
condensing units condensing units
nor variable- and and variable, two-,
multiple-capacity and multiple-
outdoor matched capacity outdoor
pairs. matched pairs.
----------------------------------------------------------------------------------------------------------------
DOE has determined that the amendments described in section III.C
and III.E of this final rule would not alter the measured energy
consumption of walk-in doors without motors or the R-value of walk-in
non-display doors and non-display panels. Therefore, retesting or
recertification would not be required solely as a result of DOE's
adoption of the amendments to the test procedures. Additionally, DOE
has determined that the amendments would not increase the cost of
testing.
For walk-in doors with motors, DOE has determined that the
amendments described in section III of this final rule would either not
change the measured energy consumption or would result in a lower
measured energy consumption and therefore, would not require retesting
or recertification as a result of DOE's adoption of the amendments to
the test procedures. New testing is only required if the manufacturer
wishes to make claims using the new, more efficient rating.
Additionally, DOE has determined the amendments would not increase the
cost of testing for doors with motors.
[[Page 28786]]
DOE has also determined that the amendments to appendix C,
described in section III.F of this final rule would not alter the
measured efficiency of walk-in refrigeration systems and would not
require retesting or recertification as a result of DOE's adoption of
the amendments to the test procedures. Additionally, DOE has determined
that the amendments would not increase the cost of testing.
Finally, DOE has determined that the provisions of the new appendix
C1 described in section III.G of this final rule would alter the
measured efficiency of walk-in refrigeration systems, in part because
the amended test procedure adopts a different energy efficiency metric
than in the current test procedure. However, the use of appendix C1 is
not required for use until the compliance date of any amended energy
conservation standards based on the test procedure in appendix C1.
Additionally, DOE has determined that the provisions in appendix C1
will increase the cost of testing. DOE's estimation of costs is
discussed in section III.K of this document.
The effective date for the amended test procedures adopted in this
final rule is 30 days after publication of this document in the Federal
Register. Representations of energy use or energy efficiency must be
based on testing in accordance with the amended appendices A, B, and C
test procedures beginning 180 days after the publication of this final
rule. Manufacturers will be required to certify compliance using the
new appendix C1 test procedures beginning on the compliance date of any
final rule establishing amended energy conservation standards for walk-
in refrigeration systems that are published after the effective date of
this final rule.
III. Discussion
A. Scope and Definitions
This final rule applies to the test procedures for ``walk-in
coolers and walk-in freezers.'' The following sections discuss DOE's
consideration of the scope of the test procedures and relevant
definitions.
1. Scope
The following sections discuss considerations and adopted changes
regarding the scope of equipment covered by DOE's test procedures for
walk-ins.
a. Liquid-Cooled Refrigeration Systems
A liquid-cooled refrigeration system rejects heat during the
condensing process to a liquid, and the liquid transports the heat to a
remote location. This contrasts with an air-cooled system, which
rejects heat to ambient air during the condensing process. The current
DOE test procedure for walk-in refrigeration systems, which
incorporates by reference AHRI 1250-2009, does not address how to test
liquid-cooled systems. Additionally, liquid-cooled dedicated condensing
units are outside the scope of AHRI 1250-2020, being specifically
excluded in Section 2.2.4. In the April 2022 NOPR, DOE tentatively
determined that liquid-cooled refrigeration systems represent a small
portion of the walk-in market, and thus DOE did not propose to amend
its test procedures to include liquid-cooled refrigeration systems. 87
FR 23920, 23927.
In response to the April 2022 NOPR, the Efficiency Advocates and CA
IOUs encouraged DOE to develop a test procedure for liquid-cooled
refrigeration systems. (Efficiency Advocates, No. 37 at p. 3; CA IOUs,
No. 42 at p. 5)
DOE recognizes the potential benefit of a test procedure for
liquid-cooled walk-ins and the value that a reliable test procedure can
provide to facilitate comparable representations of energy use for
consumers. However, DOE maintains that liquid-cooled refrigeration
systems represent a small portion of the walk-in market, and the
potential for energy savings that could be realized through the
development of a test procedure and corresponding energy conservation
standards is likely limited at this time. Additionally, DOE is not
aware of an industry test standard for liquid cooled walk-in
refrigeration systems. Therefore, although liquid-cooled refrigeration
systems are covered within the scope of the walk-in coolers and walk-in
freezers definition, DOE is not adopting provisions specific to liquid-
cooled refrigeration systems in its test procedure at this time.
b. Carbon Dioxide Systems
Currently, the DOE test procedure for walk-in refrigeration systems
does not explicitly define scope based on refrigerant. See 10 CFR
431.301 and 431.304 and appendix C. DOE understands that the current
test procedure, which is based on AHRI 1250-2009 (incorporated by
reference, 10 CFR 431.303(b)), specifies test conditions that may not
be consistent with the design and operation of carbon dioxide
(``CO2'') refrigeration systems (i.e., although AHRI 1250-
2009 does not specifically exclude CO2 systems, the test
method is not designed to accommodate such systems).\14\
---------------------------------------------------------------------------
\14\ The DOE test procedure for unit coolers requires testing
with a liquid inlet saturation temperature of 105 [deg]F and a
liquid inlet subcooling temperature of 9 [deg]F, as specified by
Tables 15 and 16 of AHRI 1250-2009. However, CO2 has a
critical temperature of 87.8 [deg]F; therefore, it does not coexist
as saturated liquid and gas above this temperature. The liquid inlet
saturation temperature of 105 [deg]F and the liquid inlet subcooling
temperature of 9 [deg]F specified in appendix C, are not achievable
by CO2 unit coolers.
---------------------------------------------------------------------------
As a result, DOE has granted waivers or interim waivers to
manufacturers from appendix C, for specific basic models of
CO2 unit coolers.\15\ The alternate test procedure granted
in these waivers and DOE's amendments with respect to refrigeration
systems utilizing CO2 as a refrigerant are further discussed
in section III.F.6 of this document.
---------------------------------------------------------------------------
\15\ HTPG Decision and Order, 86 FR 14887 (Mar. 19, 2021);
Hussmann Decision and Order, 86 FR 24606 (May 7, 2021); KeepRite
Decision and Order, 86 FR 24603 (May 7, 2021); RefPlus Interim
Waiver, 86 FR 43633 (Aug. 10, 2021).
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE tentatively determined that walk-in
refrigeration equipment utilizing CO2 as a refrigerant meets
the definition of a walk-in refrigeration system. In the April 2022
NOPR, DOE proposed test procedure provisions specific to (1) single-
packaged dedicated systems and (2) unit cooler variants of
CO2 refrigeration systems. DOE did not propose test
procedure provisions specific to CO2-dedicated condensing
units.\16\
---------------------------------------------------------------------------
\16\ As discussed in the April 2022 NOPR, DOE preliminarily
found that, in the North American market, CO2 is
primarily used in large rack systems, and there do not appear to be
any CO2 dedicated condensing units available. Hence, DOE
tentatively found that adopting a test procedure for CO2
dedicated condensing units is currently not warranted. 87 FR 23920,
23928.
---------------------------------------------------------------------------
In response to the April 2022 NOPR, the CA IOUs and HTPG stated
that CO2-dedicated condensing units are available on the
market in the United States. (CA IOUs, No. 42 at p. 4; HTPG, No. 32 at
p. 2) The CA IOUs, HTPG, and the Efficiency Advocates encouraged DOE to
develop a test procedure for CO2-dedicated condensing units.
(CA IOUs, No. 42 at p. 4; HTPG, No. 32 at p. 2; Efficiency Advocates,
No. 37 at p. 2)
DOE has conducted additional market research and determined that
while CO2 dedicated condensing units are currently available
in the United States the market is small. In addition, due to COVID
supply constraints, DOE has not been able to procure a CO2
dedicated condensing unit to evaluate for testing. Therefore, DOE is
not adopting a test procedure for CO2 dedicated condensing
units at this time. The test procedures for CO2 unit coolers
and single-packaged dedicated systems that use CO2 as a
refrigerant are discussed in
[[Page 28787]]
more detail in sections III.F.6 and III.G.2.g of this document,
respectively.
c. Multi-Circuit Single-Packaged Dedicated Systems
DOE published an interim test procedure waiver for Refrigerated
Solutions Group (RSG) on July 22, 2022. 87 FR 43808. In its petition
for waiver and interim waiver, RSG stated that the current walk-in test
procedure does not address multiple refrigeration circuits enclosed in
a single unit. DOE has determined that refrigeration systems with
multiple refrigeration circuits that share a single evaporator and a
single condenser and that are used in walk-in applications meet the
definition of ``walk-in cooler and walk-in freezer.'' Thus, DOE is
adding a definition for ``multi-circuit single-packaged dedicated
system,'' as discussed in section III.A.2.e of this document, and
adopting a test procedure for such systems, as discussed in section
III.G.2.f of this document.
d. Ducted Units
As discussed in the April 2022 NOPR, DOE is aware that some walk-in
evaporators and/or dedicated condensing units are sold with provisions
to be installed with ducting to circulate air between the walk-in and
the refrigeration system; however, unit cooler and single-packaged
systems sold for ducted installation are not addressed by either the
definition for ``single-packaged dedicated system'' or ``unit cooler.''
87 FR 23920, 23928. The current definition of ``single-packaged
dedicated system'' specifies that such systems do not have ``any
element external to the system imposing resistance to flow of the
refrigerated air,'' and the definition of ``unit cooler'' specifies
that such equipment does not have ``any element external to the cooler
imposing air resistance.'' 10 CFR 431.302. As such, unit coolers and
single-packaged dedicated systems sold for ducted installation are not
addressed by either definition. In addition, the current test procedure
does not include provisions for the setup of ductwork. While the
definition of ``condensing unit'' does not exclude systems intended for
ducted installation, the current test procedure also does not include
provisions for setup of ductwork for these components.
DOE has granted waivers from the test procedure in appendix C, to
CellarPro, Air Innovations, Vinotheque, and Vinotemp, and an interim
waiver to LRC Coil, for walk-ins marketed for use as wine cellar
refrigeration systems.\17\ Relevant to the present discussion of scope,
the specific basic models for which waivers have been granted include
equipment sold as ducted units.
---------------------------------------------------------------------------
\17\ CellarPro Decision and Order, 86 FR 26496 (May 14, 2021);
Air Innovations Decision and Order, 86 FR 23702 (May 4, 2021);
Vinotheque Decision and Order, 86 FR 26504 (May 14, 2021); Vinotemp
Decision and Order, 86 FR 36732 (July 13, 2021); LRC Coil Interim
Waiver, 86 FR 47631 (Aug. 26, 2021).
---------------------------------------------------------------------------
In this final rule, DOE is revising the single-packaged dedicated
system definition to clarify that such systems may have provisions for
ducted installation. DOE is adding a definition for ``ducted fan coil
unit,'' the ducted equivalent of a unit cooler, as discussed in section
III.A.2.d of this document. In doing so, DOE preserves the industry
standard definition of a unit cooler while expanding the scope of the
test procedure to ducted units. DOE is also adding provisions in the
test procedures to address setup of ductwork and the external static
pressure that it imposes on refrigeration system fans--all to improve
the representativeness of the test procedure for ducted units. These
test procedure revisions are addressed in section III.G.6 of this
document.
2. Definitions
a. Walk-In Cooler and Walk-In Freezer
DOE currently defines the term ``walk-in cooler and walk-in
freezer'' as an enclosed storage space refrigerated to temperatures,
respectively, above, and at or below 32 degrees Fahrenheit, that can be
walked into, and has a total chilled storage area of less than 3,000
square feet; however, the term does not include products designed and
marketed exclusively for medical, scientific, or research purposes. 10
CFR 431.302. (See also 42 U.S.C. 6311(20))
To align the definition of walk-in cooler and walk-in freezer with
the regulatory scheme adopted by DOE--which establishes separate test
procedures and energy conservation standards for the principal
components that make up a walk-in: panels, doors, and refrigeration
systems--in the April 2022 NOPR, DOE proposed to amend the definition
to specify that a walk-in may comprise these principal components. DOE
requested comment on this proposed change. 87 FR 23920, 23928.
AHRI, Anthony, RSG, HTPG, KeepRite, Lennox, and National
Refrigeration agreed with DOE's proposed changes to the definition of
walk-in cooler and walk-in freezer. (AHRI, No. 30 at p. 2; Anthony, No.
31 at p. 1; RSG, No. 41 at p. 1; HTPG, No. 32 at p. 2; KeepRite, No. 36
at p. 1; Lennox, No. 35 at p. 2; National Refrigeration, No. 39 at p.
1) For the reasons discussed in the previous paragraph and the April
2022 NOPR, DOE is adopting the definition proposed in the April 2022
NOPR that ``walk-in cooler and walk-in freezer'' means an enclosed
storage space, including but not limited to panels, doors, and
refrigeration systems, refrigerated to temperatures, respectively,
above, and at or below 32 degrees Fahrenheit that can be walked into,
and has a total chilled storage area of less than 3,000 square feet;
however, the terms do not include products designed and marketed
exclusively for medical, scientific, or research purposes.
The Efficiency Advocates commented that refrigerated shipping
containers should be within the scope of the walk-in test procedures.
(Efficiency Advocates, No. 37 at p. 4) DOE notes that based on its
initial research, neither the previous definition of walk-in cooler and
walk-in freezer nor the amended definition adopted in this final rule
would specifically exclude refrigerated shipping containers. However,
DOE has not evaluated refrigerated shipping containers to determine if
current walk-in test procedures would produce test results that reflect
energy efficiency, energy use, or estimated operating costs during a
representative average use cycle, without being unduly burdensome to
conduct. Therefore, DOE has determined that refrigerated shipping
containers are not currently subject to the DOE test procedure or
energy conservation standards for WICFs. DOE may consider whether test
procedures and energy conservation standards should be applied to
refrigerated shipping containers in future rulemakings.
b. Doors
With respect to walk-ins, DOE defines a ``door'' as an assembly
installed in an opening on an interior or exterior wall that is used to
allow access or close off the opening and that is movable in a sliding,
pivoting, hinged, or revolving manner of movement. For walk-in coolers
and walk-in freezers, a door includes the door panel, glass, framing
materials, door plug, mullions, and any other elements that form the
door or part of its connection to the wall. 10 CFR 431.302.
(1) Door, Door Leaf, and Door Plug
In the April 2022 NOPR, DOE discussed that the current definition
of ``door'' does not explicitly address that walk-in door assemblies
may contain multiple door openings within one frame. 87 FR 23920,
23929. DOE also
[[Page 28788]]
noted that NFRC 100-2010 includes several defined terms relating to
door components (e.g., door leaf), which differ from the terms used in
DOE's definition of ``door.'' Id. Additionally, certain stakeholders
commented that they are unfamiliar with the term ``door plug,'' whereas
others used it to describe different components of the door assembly.
Id.\18\
---------------------------------------------------------------------------
\18\ In response to the June 2021 RFI, Anthony and AHRI stated
that they were unfamiliar with the term ``door plug.'' (Anthony, No.
8 at pp. 1-2; AHRI, No. 11 at pp. 2-3) In response to the June 2021
RFI, Imperial Brown and Hussmann commented that they used the term
``door plug'' to describe different components of the door assembly.
(Imperial Brown, No. 15 at p. 1; Hussmann, No. 18 at p. 3)
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE proposed to amend the definition of
``door'' to address doors with multiple openings within one frame, to
include terminology that generally aligns with that used by the
industry, and to remove use of the term ``door plug.'' Id.
Specifically, DOE proposed to define ``door'' as an assembly installed
in an opening on an interior or exterior wall that is used to allow
access or close off the opening and that is movable in a sliding,
pivoting, hinged, or revolving manner of movement. For walk-in coolers
and walk-in freezers, a door includes the frame (including mullions),
the door leaf or multiple door leaves (including glass) within the
frame, and any other elements that form the assembly or part of its
connection to the wall. DOE also proposed to define the term ``door
leaf'' to mean the pivoting, rolling, sliding, or swinging portion of a
door. Id.
Regarding the proposed definition of ``door,'' Senneca considered
the proposed definition of ``door'' to refer to the door system (i.e.,
includes the door leaf, frame, casings, header, tracks, and all
necessary components and hardware). (Senneca, No. 26 at p. 1) AHRI
commented that its members find DOE's current definition unclear and
recommended that DOE not use what AHRI referred to as the ``single
door'' interpretation. (AHRI, No. 30 at p. 2) DOE interprets AHRI's
comment to mean that a door with multiple openings within a single
frame should not be treated as a single basic model. DOE notes that the
proposed definition of ``door'' is consistent with Senneca's
understanding. Additionally, DOE notes that the proposed definition
intends to clarify the definition of ``door'', particularly, that a
``door'' consists of a single frame and includes all parts of the door
assembly attached to the single frame, including multiple door openings
where applicable.
Anthony stated that the definition of ``door'' does not accurately
reflect the use of the term ``door'' in the 2014 final rule engineering
analysis spreadsheet.\19\ (Anthony, No. 31 at pp. 1-3) Specifically,
Anthony commented that when applying the same formula to a single door
with multiple openings, there is a 20 to 30 percent reduction in energy
allowance per door. Id. DOE notes that this comment refers to the
representative units used to evaluate and adopt energy conservation
standards in a final rule published on June 3, 2014 (79 FR 32050). DOE
has determined that the representative units used in 2014 met the
definition of ``door'' at the time of the analysis and would continue
to meet the definition of ``door'' as amended by this final rule.-- The
amended definition of ``door'' adopted in this final rule provides
additional clarity that a door contains a single frame with one or
multiple door openings. Regarding the energy impacts of doors with
multiple openings, DOE recommends that stakeholders provide feedback on
the representative unit characteristics in response to the ongoing
energy conservation standards rulemaking which is the appropriate venue
to address such concerns (see docket EERE-2017-BT-STD-0009).
---------------------------------------------------------------------------
\19\ Anthony is referring to the engineering analysis for
display doors as part of the June 2014 ECS Final Rule, which can be
found at regulations.gov under docket number EERE-2008-BT-STD-0015-
0084.
---------------------------------------------------------------------------
For the reasons discussed in the preceding paragraphs and the April
2022 NOPR, this final rule adopts the revised definition of ``door'' as
proposed.
Bally agreed with the term ``door leaf'' and stated that the term
as defined would be easily understood. (Bally, No. 40 at p. 1) AHRI
stated that DOE's proposed definition of ``door leaf'' is clear. (AHRI,
No. 30 at p. 2) Senneca commented that it considers ``door leaf'' to be
a movable, insulated portion of the assembly. (Senneca, No. 26 at p.
10) DOE has concluded that Senneca's comment is consistent with the
proposed definition of ``door leaf.'' This final rule adopts the
definition of ``door leaf'' as proposed in the April 2022 NOPR. 87 FR
23920, 23929.
DOE did not receive any comments regarding its proposal to remove
use of the term ``door plug.'' For the reasons discussed in the April
2022 NOPR, this final rule removes the term ``door plug'' as proposed.
Id.
(2) Non-Display Door
DOE also proposed to define the term ``non-display door'' in the
April 2022 NOPR. 87 FR 23920, 23930. Although the test procedures
outlined in 10 CFR 431.304 and appendices A and B use the term ``non-
display door,'' it is not currently defined. DOE proposed to define a
``non-display door'' as a door that is not a display door.\20\
---------------------------------------------------------------------------
\20\ DOE defines ``display door'' as a door that (1) is designed
for product display; or (2) has 75 percent or more of its surface
area composed of glass or another transparent material. 10 CFR
431.302.
---------------------------------------------------------------------------
In response to the April 2022 NOPR discussion of non-display doors,
Hussmann stated that although its Heavy Duty Door products and ABC Beer
Cave sliding door products are made largely of glass, it does not
believe these doors meet the display door definition because they are
designed to be used as passage doors (i.e., passage of people).
(Hussmann, No. 34 at p. 2) In response, DOE notes that the display door
definition references the physical characteristics of the door (i.e.,
the portion of surface area composed of glass or another transparent
material), and is not contingent on door application. Any door(s) that
meets this criteria is considered a display door, even those not
necessarily designed for product display.
In this final rule, DOE is adopting the definition of ``non-display
door'' as proposed in the April 2022 NOPR.
(3) Hinged Vertical Door, Roll-Up Door, and Sliding Door
In the April 2022 NOPR, DOE tentatively determined that
differentiating walk-in doors based on opening characteristics would
better align with industry terminology and proposed to define three
terms to further differentiate all walk-in doors (including both
display and non-display doors): ``hinged vertical door,'' ``roll-up
door,'' and ``sliding door.'' 87 FR 23920, 23930.
DOE proposed to define ``hinged vertical door'' as a door with a
door leaf (or leaves) with a hinge (or hinges) connecting one vertical
edge of the door leaf (or leaves) to a frame or mullion of the door.
This includes doors that swing open in one direction (i.e., into or out
of the walk-in) and free-swinging doors that open both into and out of
the walk-in. 87 FR 23920, 23991.
DOE proposed to define ``roll-up door'' as a door that bi-
directionally rolls open and closed in a vertical and horizontal manner
and may include vertical jamb tracks. Id.
DOE proposed to define ``sliding door'' as a door having one or
more manually operated or motorized door leaves within a common frame
that slide horizontally or vertically. Id.
[[Page 28789]]
In the April 2022 NOPR, DOE requested feedback on the proposed
definitions for ``hinged vertical door,'' ``roll-up door,'' and
``sliding door.'' Id. Senneca and AHRI agreed with DOE's proposed
definitions. (Senneca, No. 26 at p. 1; AHRI, No. 30 at p. 2)
DOE recognizes that these definitions are not used in the adopted
test procedure amendments. In the preliminary analysis for the walk-in
standards energy conservation rulemaking, DOE stated that it was
interested in differentiating its analysis by door opening
characteristics. See page ES-36 of the preliminary analysis technical
support document (EERE-2017-BT-STD-0009-0024). DOE is not adopting
definitions for the terms ``hinged vertical door,'' ``roll-up door,''
and ``sliding door'' and will consider the potential adoption of these
terms in the ongoing energy conservation standards rulemaking for
WICFs.
As discussed in the April 2022 NOPR, DOE currently differentiates
non-display doors by whether they are passage doors or freight doors.
87 FR 23920, 23929. A ``freight door'' is a door that is not a display
door and is equal to or larger than 4 feet wide and 8 feet tall. 10 CFR
431.302. A ``passage door'' is a door that is not a freight or display
door. Id. After reviewing comments submitted in response to the June
2021 RFI, DOE did not propose to amend the definition of freight door
or passage door. DOE again received comments, however, on the
definitions of freight and passage doors. 87 FR 23920, 23930.
Bally commented that specifying the way a door leaf is moved would
not aid in defining a door nor clarify whether a non-display door is a
passage or a freight door. (Bally, No. 40 at p. 1) Additionally, Bally
disagreed with the current distinction of freight doors by size,
stating that it manufactures doors with a width greater than or equal
to 4 feet that are often the only door in the WICF; therefore, it
considers these doors to be passage doors rather than freight doors.
Id. Senneca stated that it views opening size as a determinant to
whether a non-display door is designated as a passage or freight door
and reiterated that a freight door has a width-in clear \21\ (``WIC'')
greater than or equal to 4 feet and a height-in-clear \22\ (``HIC'')
greater than or equal to 8 feet. (Senneca, No. 26 at p. 1)
---------------------------------------------------------------------------
\21\ In their comment in response to the June 2021 RFI, Imperial
Brown defined WIC as the clear opening width, typically from left
frame jamb to right frame jamb. See EERE-2017-BT-TP-0010-0015 at p.
1.
\22\ In their comment in response to the June 2021 RFI, Imperial
Brown defined HIC as the clear opening height, typically from door
sill to frame header. See EERE-2017-BT-TP-0010-0015 at p. 1.
---------------------------------------------------------------------------
DOE acknowledges that stakeholder comments demonstrate that factors
other than size may be used to differentiate between a passage and
freight door. However, DOE concludes that size is currently the most
suitable way to differentiate between a passage door and a freight
door. Therefore, DOE is not amending these definitions.
c. High-Temperature Refrigeration System
As mentioned previously, DOE has granted several manufacturers
waivers and interim waivers from the current test procedure in appendix
C for basic models of refrigeration systems marketed as wine cellar
refrigeration systems (see section III.A.1.d of this document). These
manufacturers stated that walk-ins used for wine storage are intended
to operate at a temperature range of 45 to 65 [deg]F and 50 to 70
percent relative humidity, rather than the 35 [deg]F and less than 50
percent relative humidity test conditions prescribed in appendix C.
In the April 2022 NOPR, DOE proposed to define ``high-temperature
refrigeration system'' as a walk-in refrigeration system that is not
designed to operate below 45 [deg]F. 87 FR 23920, 23930. DOE did not
receive any feedback from stakeholders on the proposed definition;
however, the CA IOUs commented that they support DOE including a test
method for high-temperature unit coolers (CA IOUs, No. 42 at p. 6). DOE
is adopting the definition for ``high-temperature refrigeration
system'' as proposed in the April 2022 NOPR. Section III.G.6 provides
further details of the corresponding test procedure provisions.
d. Ducted Fan Coil Unit and Ducted Single-Packaged Dedicated System
As discussed in the April 2022 NOPR, the definitions for single-
packaged dedicated systems and unit coolers currently exclude ducted
units. 87 FR 23920, 23931. As a part of the high-temperature
refrigeration system waivers discussed in section III.A.2.c, DOE has
granted waivers to Air Innovations, Vinotheque, CellarPro, and
Vinotemp, and an interim waiver to LRC Coil, for walk-ins that are
marketed as wine cellar refrigeration systems that are designed and
marketed as ducted units.
To clarify that refrigeration systems with provision for ducted
installation are included in the DOE test procedure, DOE proposed to
adopt the new term ``ducted fan-coil unit,'' defined as an assembly
including means for forced air circulation capable of moving air
against both internal and non-zero external flow resistance and
elements by which heat is transferred from air to refrigerant to cool
the air, with provision for ducted installation. 87 FR 23920, 23931.
DOE also proposed to revise the current ``single-packaged dedicated
system'' definition to mean a refrigeration system (as defined in 10
CFR 431.302) that is a single-packaged assembly that includes one or
more compressors, a condenser, a means for forced circulation of
refrigerated air, and elements by which heat is transferred from air to
refrigerant. Id.
In the April 2022 NOPR, DOE requested comment on its proposed
definition for ``ducted fan coil unit'' and on the proposed
modification to the definition of ``single-packaged dedicated system.''
Id. RSG agreed with the proposed definitions. (RSG, No. 41 at p. 1)
AHRI and HTPG suggested separate definitions for ducted and non-ducted
single-packaged dedicated systems. (AHRI, No. 30 at pp. 2-3; HTPG, No.
32 at p. 2)
After consideration of stakeholder comments, and to maintain
consistency with industry terminology, DOE is adopting a separate
definition for ``ducted single-packaged dedicated system'' that means a
refrigeration system (as defined in 10 CFR 431.302) that is a single-
packaged assembly designed for use with ducts, that includes one or
more compressors, a condenser, a means for forced circulation of
refrigerated air, and elements by which heat is transferred from air to
refrigerant. As such, DOE is maintaining its current definition of a
``single-packaged dedicated system,'' and clarifying that it describes
non-ducted units.
DOE received no feedback from stakeholders on the proposed
definition for the new term ``ducted fan coil unit.'' DOE is adopting
the definition for ``ducted fan coil unit'' as proposed in the April
2022 NOPR.
e. Multi-Circuit Single-Packaged Dedicated System
In the April 2022 NOPR, DOE proposed to define a ``multi-circuit
single-packaged dedicated system'' as a single-packaged dedicated
system (as defined in 10 CFR 431.302) that contains two or more
refrigeration circuits that refrigerate a single stream of circulated
air. DOE requested comment on this proposed definition. 87 FR 23920,
23931.
RSG agreed with the proposed definition. (RSG, No. 41 at p. 1) AHRI
and HTPG suggested that the proposed definition is too specific and
should be
[[Page 28790]]
broader. (AHRI, No. 30 at p. 3; HTPG, No. 32 at p. 3) However, AHRI and
HTPG did not provide alternative definitions or other additional
information that might support broadening the definition.
In this final rule, DOE is adopting the definition for ``multi-
circuit single-packaged dedicated refrigeration system'' as proposed in
the April 2022 NOPR.
As discussed in section III.A.2.d, DOE proposed to adopt the new
term ``ducted fan-coil unit'' to clarify that refrigeration systems
with provision for ducted installation are included in the DOE test
procedure. 87 FR 23920, 23931. In response to the April 2022 NOPR,
several stakeholders suggested creating separate definitions for ducted
and non-ducted single-packaged dedicated systems. (AHRI, No. 30 at pp.
2-3; HTPG, No. 32 at p. 2) DOE's current definition for a ``single-
packaged dedicated system'' applies only to non-ducted units. As
discussed in section III.A.2.d, after consideration of stakeholder
comments, and to maintain consistency with industry terminology, DOE is
adopting a definition for ducted single-packaged dedicated systems
Since ducted multi-circuit single-packaged dedicated systems are a
derivative of ducted single-packaged dedicated systems, DOE is also
defining ``ducted multi-circuit single-packaged dedicated systems'' to
mean a ducted single-packaged dedicated system that contains two or
more refrigeration circuits that refrigerate a single stream of
circulated air. DOE believes these amendments are consistent with the
intent of proposed changes in the April 2022 NOPR while being
responsive to stakeholder feedback.
f. Attached Split System
As discussed in the April 2022 NOPR, DOE is aware of some
refrigeration systems that are sold as matched pairs in which the
dedicated condensing unit and unit cooler are permanently attached to
each other with structural beams. 87 FR 23920, 23931. The DOE test
procedure does not currently define such systems, nor does it provide
any unique test provisions for them, thereby affecting the ability of
manufacturers to provide test results reflecting the energy efficiency
of this equipment during a representative average use cycle. DOE
proposed to define ``attached split system'' as a matched-pair
refrigeration system designed to be installed with the evaporator
entirely inside the walk-in enclosure and the condenser entirely
outside the walk-in enclosure, and the evaporator and condenser are
permanently connected with structural members extending through the
walk-in wall. Id.
In the April 2022 NOPR, DOE requested comment on the proposed
definition for ``attached split system.'' Id. AHRI, HTPG, Hussmann, and
Lennox agreed with the proposed definition. (AHRI, No. 30 at p. 3;
HTPG, No. 32 at p. 3; Hussmann, No. 38 at p. 2; Lennox, No. 35 at p. 2)
In this final rule, DOE is adopting the proposed definition for
``attached split system.'' The provisions for testing such units are
discussed in section III.G.4 of this document.
g. Detachable Single-Packaged System
As discussed in the April 2022 NOPR, DOE had tentatively determined
that detachable single-packaged systems are a type of single-packaged
dedicated system, and proposed to define ``detachable single-packaged
system'' as a system consisting of a dedicated condensing unit and an
insulated evaporator section in which the evaporator section is
designed to be installed external to the walk-in enclosure and
circulating air through the enclosure wall, and the condensing unit is
designed to be installed either attached to the evaporator section or
mounted remotely with a set of refrigerant lines connecting the two
components. 87 FR 23920, 23931. The current DOE test procedure does not
define such systems or provide testing provisions specific to this
configuration.
In the April 2022 NOPR, DOE requested comment on the proposed
definition for ``detachable single-packaged dedicated system.'' Id.
AHRI, HTPG, Lennox, and RSG agreed with the proposed definition. (AHRI,
No. 30 at p. 3; HTPG, No. 32 at p. 3; Lennox, No. 35 at p. 2; RSG, No.
41 at p. 1)
In this final rule, DOE is adopting the definition for ``detachable
single-packaged dedicated system'' as proposed in the April 2022 NOPR.
h. CO2 Unit Cooler
In the April 2022 NOPR, DOE proposed a test procedure for
CO2 unit coolers. 87 FR 23920, 23952. To clarify the scope
of the proposed CO2 unit cooler test procedure, DOE proposed
to define a ``CO2 unit cooler'' as one that includes a
nameplate listing only CO2 as an approved refrigerant. 87 FR
23920, 23932.
In the April 2022 NOPR, DOE requested comment on the proposed
definition of CO2 unit coolers. Id. AHRI, HTPG, Hussmann,
Lennox, National Refrigeration, and RSG agreed with the proposed
definition. (AHRI, No. 30 at p. 3; HTPG, No. 32 at p. 3; Hussmann, No.
38 at p. 2; Lennox, No. 35 at p. 2; National Refrigeration, No. 39 at
p. 1; RSG, No. 41 at p. 1)
DOE also requested comment on whether any distinguishing features
of CO2 unit coolers exist that could reliably be used as an
alternative approach to differentiate them from those unit coolers
intended for use with conventional refrigerants. 87 FR 23920, 23932.
AHRI, HTPG, Lennox, and National Refrigeration all stated that they
were not aware of any features that distinguish CO2 unit
coolers from those that use traditional refrigerants. (AHRI, No. 30 at
p. 3; HTPG, No. 32 at p. 3; Lennox, No. 35 at p. 2; National
Refrigeration, No. 39 at p. 1)
Given that stakeholders are not aware of any features that
distinguish CO2 unit coolers from those that use traditional
refrigerants, this information must be provided on the unit in some
way. Therefore, DOE is adopting the ``CO2 unit cooler''
definition proposed in the April 2022 NOPR which requires a nameplate
listing only CO2 as an approved refrigerant for this
equipment.
i. Hot Gas Defrost
In the April 2022 NOPR, DOE proposed that manufacturers of
equipment with hot gas defrost installed at the factory may make market
representations of performance with hot gas defrost activated, in
addition to the current required calculation-based approach using
default electric defrost parameters, and proposed a definition for
``hot gas defrost'' to clarify the scope of the voluntary
representation. 87 FR 23920, 23932.
AHRI, HTPG, KeepRite, Lennox, National Refrigeration, and RSG all
recommended changes to the definition as proposed. (AHRI, No. 30 at p.
3; HTPG, No. 32 at p. 3; KeepRite, No. 36 at p. 1; Lennox, No. 35 at p.
2; National Refrigeration, No. 39 at p. 1; RSG, No. 41 at p. 4) In
particular, AHRI, HTPG, and Lennox stated that not all hot gas defrost
systems are factory installed. (AHRI, No. 30 at pp. 3-4; HTPG, No. 32
at p. 3; Lennox, No. 35 at p. 2)
DOE intended for the voluntary hot gas defrost representation
provisions proposed in the April 2022 NOPR to apply only to factory-
installed hot gas defrost systems. 87 FR 23920, 23970. Considering the
comments received, DOE recognizes that the proposed provisions would
not apply to many hot gas defrost applications, thus negating the
purpose and intent of DOE's proposal. Therefore, DOE has determined not
to adopt provisions allowing representations of performance with hot
gas defrost activated at this
[[Page 28791]]
time and consequently is not adopting a definition for ``hot gas
defrost.''
B. Updates to Industry Standards
The current DOE test procedures for walk-in coolers and freezers
incorporate the following industry test standards: NFRC 100-2010 into
appendix A; ASTM C518-04 into appendix B; and AHRI 1250-2009, AHRI 420-
2008,\23\ and ASHRAE 23.1-2010 \24\ into appendix C. The following
sections discuss the industry standards DOE is incorporating by
reference in this final rule and the relevant provisions of those
industry standards that DOE is adopting.
---------------------------------------------------------------------------
\23\ AHRI 420-2008, ``Performance Rating of Forced-Circulation
Free-Delivery Unit Coolers for Refrigeration'' (``AHRI 420-2008'').
\24\ ANSI/ASHRAE 23.1-2010, ``Methods of Testing for Rating the
Performance of Positive Displacement Refrigerant Compressors and
Condensing Units that Operate at Subcritical Temperatures of the
Refrigerant'' (``ASHRAE 23.1-2010'').
---------------------------------------------------------------------------
1. Industry Standards for Determining Thermal Transmittance (U-Factor)
As discussed in the April 2022 NOPR, appendix A to subpart R of
part 431 references NFRC 100-2010 as the method for determining the U-
factor of doors and display panels, which references NFRC 102-2010. 87
FR 23920, 23932. NFRC has published updates to NFRC 102-2010, the most
recent being NFRC 102-2020, which contains the following substantive
changes from NFRC 102-2010:
1. Added a list of required calibrations for primary measurement
equipment;
2. Added metering box wall transducer and surround panel flanking
loss characterization and annual verification procedure;
3. Incorporated a calibration transfer standard continuous
characterization procedure; and
4. Revised the provisions regarding air velocity distribution to be
more specific to the type of fans used.
DOE proposed to adopt by reference in appendix A the following
sections of NFRC 102-2020 in place of NFRC 100-2010 for determining U-
factor:
2. Referenced Documents
3. Terminology
5. Apparatus
6. Calibration
7. Experimental Procedure (excluding 7.3. Test Conditions)
8. Calculation of Thermal Transmittance
9. Calculation of Standardized Thermal Transmittance
Annex A1. Calibration Transfer Standard Design
Annex A2. Radiation Heat Transfer Calculation Procedure
Annex A4. Garage Panel and Rolling Door Installation
87 FR 23920, 23932.
DOE also proposed to incorporate by reference ASTM C1199-14, as it
is referenced in NFRC 102-2020. Specifically, in the appendix A test
procedure, DOE proposed to reference the following sections of ASTM
C1199-14 as referenced through NFRC 102-2020: sections 2, 3, 5, 6, 7
(excluding 7.3), 8, 9, and annexes A1 and A2. DOE did not propose to
reference any other sections of NFRC 102-2020 or ASTM C1199-14, as
either they do not apply or they are in direct conflict with other test
procedure provisions included in appendix A.
In this final rule, DOE is incorporating by reference NFRC 102-2020
and ASTM C1199-14 in appendix A as proposed in the April 2020 NOPR. DOE
further discusses the reference to NFRC 102-2020 in place of NFRC 100-
2010 and addresses stakeholder comments in section III.C.1 of this
document.
2. Industry Standard for Determining R-Value
As discussed in the April 2022 NOPR, section 4.2 of appendix B to
subpart R of part 431 references ASTM C518-04 \25\ to determine the
thermal conductivity, or K-factor, of panel insulation. 87 FR 23920,
23932. ASTM published a revision of ASTM C518 in July 2017 (``ASTM
C518-17''). Id.
---------------------------------------------------------------------------
\25\ ASTM C518-04 is the version of the industry test procedure
specified by EPCA as the basis for calculating the K-factor.
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE tentatively determined that the updates
in ASTM C518-17 do not substantively change the test method and do not
impact test burden compared to ASTM C518-04. Therefore, DOE proposed to
amend its test procedure for determining insulation R-value for non-
display doors and panels by incorporating by reference ASTM C518-17.
Specifically, in the test procedure in appendix B, DOE proposed to
reference the following sections of ASTM C518-17:
2. Referenced Documents
3. Terminology
5. Apparatus
6. Calibration
7. Test Procedures (excluding 7.3. Specimen Conditioning)
8. Calculation
Annex A1. Equipment Design
87 FR 23920, 23933.
DOE did not propose to reference any other sections of ASTM C518-
17, as either they do not apply or they are in direct conflict with
other test procedure provisions included in appendix B. Because ASTM
C518-17 is an updated version of ASTM C518-04, DOE stated in the April
2022 NOPR that the test procedure for determining the K-factor would
effectively remain based on ASTM C518-04 as specified by EPCA (42
U.S.C. 6314(a)(9)(A)(ii)).
In response to the April 2022 NOPR, Anthony supported the proposal
to reference the latest version of the industry test procedure, ASTM
C518-17. (Anthony, No. 31 at p. 3)
In this final rule, DOE is incorporating by reference the sections
of ASTM C518-17 as proposed in the April 2022 NOPR.
3. Industry Standards for Determining AWEF
DOE's current test procedure for WICF refrigeration systems is
codified in appendix C to subpart R of part 431 and incorporates by
reference AHRI 1250-2009, AHRI 420-2008, and ASHRAE 23.1-2010. AHRI
1250-2009 is the industry test standard for walk-in cooler and freezer
refrigeration systems, including unit coolers and dedicated condensing
units sold separately, as well as matched pairs. 81 FR 95758,
95798.\26\ The procedure describes the method for measuring the
refrigeration capacity and the electrical energy consumption for a
condensing unit and a unit cooler, including off-cycle fan and defrost
subsystem contributions. Using the refrigeration capacity and
electrical energy consumption, AHRI 1250-2009 provides a calculation
methodology to compute AWEF, the applicable energy performance metric
for refrigeration systems.
---------------------------------------------------------------------------
\26\ Available at www.ahrinet.org.
---------------------------------------------------------------------------
The DOE test procedure for walk-in refrigeration systems
incorporates by reference the test procedure in AHRI 1250-2009
(excluding Tables 15 and 16), with certain enumerated modifications.
See appendix C to subpart R of part 431.
In April 2020, AHRI published AHRI 1250-2020, which incorporates
many of the modifications and additions to AHRI 1250-2009 that DOE
currently prescribes in its test procedure at appendix C. It also
includes test methods for unit coolers and dedicated condensing units
tested alone, rather than incorporating by reference updated versions
of AHRI 420-2008 and/or ASHRAE 23.1-2010. AHRI 1250-2020 also includes
test methods for single-packaged dedicated systems.
The following sections discuss the amendments being adopted in
appendix
[[Page 28792]]
C and appendix C1 with respect to the aforementioned industry test
methods.
a. Appendix C
In the April 2022 NOPR, DOE proposed minor modifications to
appendix C that improve test procedure accuracy and repeatability,
while maintaining equivalent measurements of AWEF. 87 FR 23920, 23933.
As discussed further in the section that follows, DOE also proposed to
establish a new appendix C1 to subpart R that would incorporate
substantive changes that would result in different measured values of
efficiency, AWEF2, compared to appendix C. DOE proposed that the use of
appendix C with the proposed amendments would be required 180 days
after this test procedure final rule is published and would remain
required for use until the compliance date of any future amended energy
conservation standards based on appendix C1.
Within appendix C, DOE proposed to maintain reference to AHRI 1250-
2009. DOE proposed to adopt certain instrument accuracy and test
tolerances from AHRI 1250-2020 that would not change the measured AWEF
value, as discussed further in section III.F.5 of this document.
DOE received no comments on its proposal to maintain appendix C,
with modification, until the compliance date of any future amended
energy conservation standards based on appendix C1.
In this final rule, DOE maintains the required use of appendix C,
as amended by this final rule, including the incorporation by reference
of AHRI 1250-2009, until the compliance date of any future amended
energy conservation standards based on appendix C1.
b. Appendix C1
As discussed, in the April 2022 NOPR, DOE proposed to establish a
new appendix C1 to subpart R that incorporates by reference AHRI 1250-
2020. 87 FR 23920, 23933. DOE tentatively determined that the changes
proposed in appendix C1 through the incorporation of AHRI 1250-2020
would increase the representativeness of the DOE test procedure for
walk-ins. DOE also tentatively determined that several of the changes
in AHRI 1250-2020 would change the measured AWEF value. These changes
can be grouped into five categories: off-cycle tests, single-packaged
dedicated systems, defrost calculations, variable capacity, and default
unit cooler parameters. These changes and the comments received on
these proposed changes are discussed in detail in section III.G. Since
these changes would result in a change to measured AWEF, DOE proposed
to establish a new metric called ``AWEF2.''
In the April 2022 NOPR, DOE proposed to incorporate AHRI 1250-2020
for use in appendix C1, with the following exclusions:
Section 1 Purpose
Section 2 Scope
Section 9 Minimum Data Requirements for Published Ratings
Section 10 Marking and Nameplate Data
Section 11 Conformance Conditions
Section C10.2.1.1 Test Room Conditioning Equipment under
section C10--Defrost Calculation and Test Methods
87 FR 23920, 23933.
DOE proposed to exclude these sections of AHRI 1250-2020 because
they either do not apply or conflict with other test procedure
provisions included in appendix C1.
Further, DOE proposed to reference ASHRAE 16-2016 in appendix C1,
as it is referenced in AHRI 1250-2020, with the following exclusions:
Section 1 Purpose
Section 2 Scope
Section 4 Classifications
Normative Appendices E-M
Informative Appendices N-R
87 FR 23920, 23934.
DOE did not propose to reference these sections of ASHRAE 16-2016,
as either they do not apply or they conflict with other test procedure
provisions that are included as part of appendix C1.
Similarly, DOE proposed to reference ASHRAE 37-2009 in appendix C1,
as it is referenced in AHRI 1250-2020, with the following exclusions:
Section 1 Purpose
Section 2 Scope
Section 4 Classifications
Informative Appendix A Classifications of Unitary Air-
conditioners and Heat Pumps
Id.
DOE did not propose to reference these sections of ASHRAE 37-2009,
as either they do not apply, or they conflict with other test procedure
provisions that are included as part of appendix C1.
As discussed in the April 2022 NOPR, AHRI 1250-2020 incorporates
many of the modifications and additions to AHRI 1250-2009 that DOE
currently prescribes in its appendix C test procedure. Id. Since DOE
proposed to adopt AHRI 1250-2020, DOE did not propose to carry over the
sections listed in Table III.1 from appendix C to appendix C1.
Table III.1--List of Sections in Appendix C Not Proposed To Be Included
in Appendix C1
------------------------------------------------------------------------
Appendix C Summary
------------------------------------------------------------------------
Section 3.1.1..................... Modifies Table 1 (Instrumentation
Accuracy) in AHRI 1250-2009.
Section 3.1.2..................... Provides guidance on electrical
power frequency tolerances.
Section 3.1.3..................... States that in Table 2 of AHRI 1250-
2009, the test operating tolerances
and test condition tolerances for
air leaving temperatures shall be
deleted.
Section 3.1.4..................... States that in Tables 2 through 14
in AHRI 1250-2009, the test
condition outdoor wet-bulb
temperature requirement and its
associated tolerance apply only to
units with evaporative cooling.
Section 3.1.5..................... Provides tables to use in place of
AHRI 1250-2009 Tables 15 and 16,
which are excluded from the
reference in 10 CFR 431.303.
Section 3.2.1..................... Provides specific guidance on how to
measure refrigerant temperature.
Section 3.2.2..................... Removes the requirement to perform a
refrigerant composition and oil
concentration analysis.
Section 3.2.5..................... Provides insulation and
configuration requirements for
liquid and suction lines used for
testing.
Section 3.3.1..................... Gives direction for how to test and
rate unit coolers tested alone.
Section 3.3.2..................... Clarifies that the 2008 version of
AHRI Standard 420 should be used
for unit coolers tested alone.
Section 3.3.3..................... Modifies the allowable reduction in
fan speed for off-cycle evaporator
testing.
Section 3.4.1..................... Specifies that the 2010 version of
ASHRAE 23.1 should be used and that
``suction A'' condition test points
should be used when testing
dedicated condensing units.
Section 3.4.2..................... Provides instruction on how to
calculate AWEF and net capacity for
dedicated condensing units.
Section 3.5....................... Provides guidance on how to rate
refrigeration systems with hot gas
defrost.
------------------------------------------------------------------------
[[Page 28793]]
AHRI 1250-2020 does not incorporate all the modifications and
additions to AHRI 1250-2009 that DOE currently prescribes in its test
procedure. Therefore, DOE proposed that the modifications in sections
3.2.3, 3.3.4, 3.3.5, and 3.3.7 of appendix C be incorporated into
appendix C1.
In response to the April 2022 NOPR, DOE received several general
comments about the incorporation of AHRI 1250-2020 for use in appendix
C1. AHRI and National Refrigeration commented that they disagreed with
DOE aligning appendix C1 with AHRI 1250-2020 and requested further
clarification on the proposal. (AHRI, No. 30 at p. 7; National
Refrigeration, No. 39 at p. 2) Neither AHRI nor National Refrigeration
provided detail about what specifically they disagreed with, or which
aspects of DOE's proposal required further clarification.
In response to the April 2022 NOPR, HTPG requested details on the
changes in the new appendix C1 that may impact the determination of
AWEF for unit coolers and variable-capacity systems. (HTPG, No. 32 at
p. 2) These topics are discussed in detail in sections III.G.7 and
III.G.11 of this document, respectively.
As discussed in this section and in more detail in section III.G,
DOE has concluded that the changes in AHRI 1250-2020 improve the
representativeness of the walk-in refrigeration systems test procedure.
Therefore, DOE is incorporating AHRI 1250-2020, ASHRAE 37-2009, ASHRAE
16-2016 for use in appendix C1 as proposed in the April 2022 NOPR.
c. Additional Amendments
AHRI 1250-2020 includes additional amendments that are inconsistent
with AHRI 1250-2009 but are either not referenced in the DOE test
procedure or serve to make aspects of the test procedure more explicit
or clear. None of these changes impact measured AWEF. These additional
amendments are discussed in the paragraphs below.
AHRI 1250-2020 added exclusions for liquid-cooled condensing
systems in section 2.2.4 and excludes systems that use carbon dioxide,
glycol, or ammonia as refrigerants in section 2.2.5. As mentioned
previously, DOE is not incorporating section 2 of AHRI 1250-2020 into
appendix C1.
AHRI 1250-2020 includes an updated list of references and the
applicable versions of certain test standards in appendix A,
``References--Normative.'' DOE does not expect these changes to impact
measured AWEF apart from ways discussed in section III.G. AHRI 1250-
2020 added specifications for refrigerant temperature measurement
locations for unit coolers tested alone, matched pairs, and dedicated
condensing systems tested alone in sections C3.1.3.1, C3.1.3.2, and
C3.1.3.3. DOE has determined that these specifications will not affect
measured AWEF.
AHRI 1250-2020 revised section C7.5.1 to provide more detailed
instructions for calculating system capacity beginning with measured
temperatures and pressures instead of calculated enthalpies, which is
what was done in AHRI 1250-2009. Section C7.5.1 also includes the
determination of capacity from enthalpy calculation results. The
addition of these sections provides clarity and further instruction but
does not affect measured AWEF.
AHRI 1250-2009 included section C12, ``Method of Testing Condensing
Units for Walk-in Cooler and Freezer Systems for Use in Mix-Match
System Ratings,'' which referenced ASHRAE 23.1-2010. AHRI 1250-2020 now
provides specific methods for testing dedicated condensing units tested
alone. DOE has determined that the test procedure incorporated into
AHRI 1250-2020 is the same as that in ASHRAE 23.1-2010 and therefore
does not impact measured AWEF.
Section C13 of AHRI 1250-2009, ``Method of Testing Unit Coolers for
Walk-in Cooler and Freezer Systems for Use in Mix-Match System
Ratings,'' referenced AHRI 420-2008. AHRI 1250-2020 no longer
references AHRI 420-2008 and instead outlines a method for unit coolers
tested alone. DOE has determined that the test procedure incorporated
into AHRI 1250-2020 is the same as that in ASHRAE AHRI 420-2008 and
therefore does not impact measured AWEF. As a result, DOE is not
incorporating by reference AHRI 420-2008 in new appendix C1.
C. Amendments to Appendix A for Doors
Appendix A provides test procedures for measuring walk-in envelope
component energy consumption. Specifically, appendix A provides the
test procedures to determine the U-factor, conduction load, and energy
use of walk-in display panels and to determine the energy use of walk-
in display doors and non-display doors (see section III.D for
discussion of display panels).
In the April 2022 NOPR, DOE proposed several changes to appendix A
specific to display doors and non-display doors. 87 FR 23920, 23936-
23943. DOE determined that these changes would improve test
representativeness and repeatability. DOE stated in the April 2022 NOPR
that it did not expect the changes it proposed to have a substantive
impact on measured energy consumption calculations for display doors or
non-display doors, except in the case of testing doors with motors.
The following sections describe the modifications that DOE proposed
to appendix A with respect to walk-in display and non-display doors.
1. Reference to NFRC 102-2020 in Place of NFRC 100-2010 and Alternative
Efficiency Determination Methods for Doors
a. NFRC 102-2020 in Place of NFRC 100-2010
Appendix A references NFRC 100-2010 as the method for determining
the U-factor of doors and display panels. NFRC 100-2010 allows for
computational determination of U-factor by simulating U-factor using
Lawrence Berkeley National Lab's (LBNL) WINDOW and THERM software,
provided that the simulated value for the baseline product in a product
line is validated with a physical test of that baseline product and the
simulated value is within the accepted agreement with the physical test
value as specified in section 4.7.1 of NFRC 100-2010.\27\
---------------------------------------------------------------------------
\27\ Section 4.7.1 of NFRC 100-2010 requires that the accepted
difference between the tested U-factor and the simulated U-factor be
(a) 0.03 Btu/(h-ft\2\-[deg]F) for simulated U-factors that are 0.3
Btu/(h-ft\2\-[deg]F) or less, or (b) 10 percent of the simulated U-
factor for simulated U-factors greater than 0.3 Btu/(h-ft\2\-
[deg]F). This agreement must match for the baseline product in a
product line. Per NFRC 100, the baseline product is the individual
product selected for validation; it is not synonymous with ``basic
model'' as defined in 10 CFR 431.302.
---------------------------------------------------------------------------
As discussed in the April 2022 NOPR, DOE is aware there has been
limited success using the computational method in NFRC 100-2010 to
simulate U-factors of non-display doors. 87 FR 23920, 23936-23937.
Thus, DOE proposed to remove reference to NFRC 100-2010 (i.e., the
computational method) and instead reference NFRC 102-2020 (i.e., the
physical test method) for determining U-factor. Id. Consistent with
that proposal, and with stakeholder concerns regarding test burden
given the highly customizable nature of the walk-in door market, DOE
also proposed to allow use of alternative efficiency determination
methods (AEDMs) to determine the represented value of energy
consumption of walk-in doors at 10 CFR 429.53(a)(3). 87 FR 23920,
23972.
In response, Bally stated that it looks forward to using AEDMs to
rate its walk-in doors. (Bally, No. 40 at p. 5) RSG also agreed with
the proposal to allow for AEDMs. (RSG, No. 41 at p. 2)
[[Page 28794]]
Hussmann noted that, although it is ``not pleased'' with the
current NFRC 100-2010 test method, it does not support use of an AEDM
because it believes rating with an AEDM creates an opportunity for
``approved non-compliance.'' (Hussmann, No. 34 at pp. 3-4)
DOE acknowledges Hussmann's concern but notes that rating a basic
model with an AEDM does not excuse a manufacturer from complying with
the relevant energy conservation standards. DOE has several
requirements pertaining to AEDM records retention; the ability to
provide analyses, conduct simulations, or conduct certification testing
of basic models rated with the AEDM at DOE's request; and verification
testing of an AEDM by DOE. These requirements can be found in 10 CFR
429.70(f)(3) through (5). DOE enforces all these requirements.
DOE notes that despite the limited success historically with using
the computational method in NFRC 100-2010, to the extent that
manufacturers have successfully used the simulation method in NFRC 100-
2010 to produce accurate results, such results would be acceptable as
an AEDM. AEDMs and the specific provisions DOE is adopting pertaining
to AEDMs for doors are explained and discussed in the following
section.
b. Alternative Efficiency Determination Methods for Doors
Pursuant to the requirements of 10 CFR 429.70, DOE may permit use
of an AEDM in lieu of testing equipment for which testing burden may be
considerable and for which that equipment's energy efficiency
performance may be well predicted by such alternative methods. Although
specific requirements vary by product or equipment, use of an AEDM
entails development of a mathematical model that estimates energy
efficiency or energy consumption characteristics of the basic model, as
would be measured by the applicable DOE test procedure. The AEDM must
be based on engineering or statistical analysis, computer simulation or
modeling, or other analytic evaluation of performance data. A
manufacturer must perform validation of an AEDM by demonstrating that
the performance, as predicted by the AEDM, agrees with the performance
as measured by actual testing in accordance with the applicable DOE
test procedure. The validation procedure and requirements, including
the statistical tolerance, number of basic models, and number of units
tested vary by product or equipment.
Once developed and validated, an AEDM may be used to rate and
certify the performance of untested basic models in lieu of physical
testing. Use of an AEDM for any basic model is always at the option of
the manufacturer. One potential advantage of AEDM use is that it may
free a manufacturer from the burden of physical testing. One potential
risk is that the AEDM may not perfectly predict performance, and the
manufacturer could be found responsible for having an invalid rating
for the equipment in question or for having distributed a noncompliant
basic model. The manufacturer, by using an AEDM, bears the
responsibility and risk of the validity of the ratings.
For walk-ins, DOE currently permits the use of AEDMs for
refrigeration systems only. 10 CFR 429.70(f). As discussed previously,
DOE proposed to allow the use of AEDMs for rating walk-in doors in the
April 2022 NOPR. 87 FR 23920, 23972. Concurrent with this proposal, DOE
proposed a number of provisions specific to the validation and use of
an AEDM. First, DOE proposed to include walk-in door validation classes
at 10 CFR 429.70(f)(2)(iv) and to require that two basic models per
validation class be tested using the proposed test procedure in
appendix A, which is consistent with the number of basic models
required to be tested per validation class for walk-in refrigeration
systems. Id.
Second, DOE proposed to include a 5 percent individual model
tolerance, which aligns with the individual model tolerance applicable
to walk-in refrigeration systems, to validate the measured energy
consumption result of an AEDM with the appendix A test result at 10 CFR
429.70(f)(2)(ii). Id. The individual model tolerance is used to
validate the AEDM. This means that when validating the AEDM for use,
the predicted daily energy consumption for each model calculated by
applying the AEDM may not be more than 5 percent less than the daily
energy consumption determined from the corresponding test of the model.
DOE also proposed that an AEDM for doors can only simulate or model
characteristics of the door that are required to be tested by the DOE
test procedure--i.e., for the doors test procedure, the AEDM would be
used to simulate or model the U-factor, which is the only part of the
appendix A test procedure that is not a calculation. The AEDM cannot be
used to simulate or model the energy consumption due to conduction
thermal load, or the direct and indirect electrical energy consumption
of electricity-consuming devices sited on the door--those must be
calculated using the appendix A test procedure. However, when
validating the AEDM, the comparison between a door that has been
physically tested versus a door that has been modeled or simulated must
be done using the complete metric (i.e., total daily energy
consumption). In other words, the AEDM can only be used to determine
the U-factor, but the total daily energy consumption using an AEDM must
be carried out using the calculations in appendix A for the energy
consumption due to conduction thermal load, and the direct and indirect
electrical energy consumption. Then, the validation of an AEDM would
compare the energy consumption calculated using a simulated U-factor
with the energy consumption calculated using a tested U-factor.
Lastly, DOE proposed to include a 5 percent tolerance applicable to
the maximum daily energy consumption metric for AEDM verification
testing conducted by DOE at 10 CFR 429.70(f)(5)(vi), which aligns with
the tolerance applicable to AWEF of walk-in refrigeration systems. Id.
DOE may randomly select and test a single unit of a basic model to
assess whether a basic model is in compliance with the applicable
energy conservation standards pursuant to 10 CFR 429.104, which extends
to all DOE covered products and equipment, including those certified
using an AEDM. As part of the AEDM requirements, DOE may use the test
data from an assessment test for a given model to verify the certified
rating determined by an AEDM. This is called verification testing. See
10 CFR 429.70(f)(5). For doors using an energy consumption metric, the
result from a DOE verification test must be less than or equal to the
certified rating multiplied by (1 plus the applicable tolerance); i.e.,
the DOE verification test result must be less than or equal to 105
percent of the certified rating.
In the April 2022 NOPR, DOE requested comment on the specific
proposals pertaining to the validation and use of AEDMs for doors. Id.
RSG agreed with the proposals. (RSG, No. 41 at p. 2)
Anthony disagreed with DOE removing the reference to NFRC 100-2010
for NFRC 102-2020 and allowing AEDMs because it believes an AEDM would
require more testing and result in an increased financial and physical
burden on manufacturers without achieving an additional energy benefit.
(Anthony, No. 31 at pp. 3, 8-9) Additionally, Anthony stated that if
NFRC 100-2010 is able to be used as an AEDM, the application of the 5
percent
[[Page 28795]]
tolerance on the energy consumption metric, Edd, would
conflict with the NFRC 100-2010 standard without achieving an
additional energy benefit. Id. AHRI commented that the AEDM strategy
with respect to U-factor is unclear and requested clarification of what
the proposed 5 percent model tolerance applies to. (AHRI, No. 30 at p.
11)
DOE is clarifying that to use an AEDM, the manufacturer must first
validate the AEDM. To validate the AEDM, the manufacturer must select
at least the minimum number of basic models for each validation class
(specified in table 1 to 10 CFR 429.70(f)(2)(iv)(A)) and physically
test a single unit of each basic model. Thus, for a single validation
class, where DOE proposed two basic models be tested per validation
class, only two physical tests would be required, although more testing
may be conducted at the manufacturer's discretion. The manufacturer
would be required to conduct the physical U-factor tests according to
NFRC 102-2020 referenced by appendix A and carry out the energy
consumption calculations as done in appendix A. For the AEDM, the
manufacturer would model or simulate the U-factor using a method of
their choice, and then carry out the energy consumption calculations as
done for the physical test, only deviating by using the simulated U-
factor in the calculations. All other parts of the energy consumption
calculations shall be done according to appendix A and may not be
modeled. To validate the AEDM, the energy consumption output using the
physical test must be compared with the energy consumption output using
the AEDM for each basic model used for validation. If the output using
the AEDM is lower than the physical test output by more than the
individual model tolerance (i.e., 5 percent), then the AEDM is not
valid. If the output using the AEDM is greater than or equal to 95
percent of the output using physical testing and meets the standard for
at least two basic models, then the AEDM has been validated for that
validation class.
To illustrate the minimum number of physical tests required,
consider an example of a display door manufacturer that produces models
in two validation classes: medium-temperature and low-temperature. This
manufacturer would need to, at a minimum, physically test the U-factor
and calculate the energy consumption of two basic models per validation
class, thus requiring a total of four physical tests: two for the
medium-temperature display door validation class and two for the low-
temperature display door validation class. The manufacturer would use
the U-factor test results to calculate the total daily energy
consumption each door. Then, the manufacturer would use their AEDM to
model or simulate the U-factor of each door and calculate each door's
total daily energy consumption. Each basic model's simulated and tested
total daily energy consumption results would be compared using the
tolerance of 5 percent in order to validate the AEDM. DOE stresses that
this 5 percent tolerance used to validate the AEDM would only apply to
the comparison of tested and simulated energy consumption for the
minimum number of models physically tested for validation of the AEDM.
If the AEDM is validated, the manufacturer could then use the AEDM to
rate the remainder of the basic models it manufacturers in those
validation classes. The 5 percent tolerance would not be used for any
models simulated without a physical test because the AEDM was validated
and thus no physical test would be further required.
DOE emphasizes that allowing use of an AEDM would provide
manufacturers with the flexibility to use an alternative method (i.e.,
besides NFRC 100-2010) that yields the best agreement with a physical
test for their doors. Additionally, DOE notes that the change in test
burden associated with the use of an AEDM is dependent on a
manufacturer's product offerings. If a manufacturer does not have
success with NFRC 100-2010 and is currently required to physically test
all basic models, the AEDM option may reduce the test burden by
requiring only two basic models per validation class to be tested. DOE
is aware there has been limited success using the computational method
in NFRC 100-2010 to simulate U-factors of non-display doors. Therefore,
DOE expects a reduction of test burden across the industry since
allowing AEDMs generally provides manufacturers, particularly those
that manufacture non-display doors, the flexibility to use an alternate
method that works best for them and meets the AEDM criteria established
by DOE. However, if a manufacturer currently has success using NFRC
100-2010, there could be an increase in test burden, but only if the
manufacturer currently validates the use of the simulation method with
less than two basic models per validation class. Test burden and costs
are discussed further in section III.K.1 of this document. The
inclusion of AEDM provisions would enable manufacturers to continue
using NFRC 100-2010, provided that manufacturers meet the AEDM
requirements in 10 CFR 429.53 and 429.70(f). Therefore, DOE is removing
reference to NFRC 100-2010 from its test procedure and is instead
referencing NFRC 102-2020 and adopting provisions that allow
manufacturers to use an AEDM, as proposed in the April 2022 NOPR.
c. Exceptions to the Industry Test Method for Determining U-Factor
Section 5.3 of appendix A references NFRC 100-2010 for determining
U-factor, and section 5.3(a) of appendix A specifies four exceptions to
that industry standard. The first exception implements a tolerance on
the surface heat transfer coefficients (no such tolerance is specified
in NFRC 100-2010); specifically, that the average surface heat transfer
coefficients during a test must be within 5 percent of the
values specified through NFRC 100-2010 in ASTM C1199. The second and
third exceptions modify the cold and warm-side conditions from the
standard conditions prescribed in NFRC 100-2010. The fourth exception
specifies the direct solar irradiance be 0 Btu/(h-ft\2\).
Sections 6.2.3 and 6.2.4 of ASTM C1199 specify the standardized
heat transfer coefficients and their tolerances as part of the
procedure to set the surface heat transfer conditions of the test
facility using the Calibration Transfer Standard (``CTS'') test. The
warm-side surface heat transfer coefficient must be within
5 percent of the standardized warm-side value of 1.36 Btu/(h-ft\2\-
[deg]F), and the cold-side surface heat transfer coefficient must be
within 10 percent of the standardized cold-side value of
5.3 Btu/(h-ft\2\-[deg]F) during the CTS test (ASTM C1199, sections
6.2.3 and 6.2.4). ASTM C1199 does not require that the measured surface
heat transfer coefficients match or be within a certain tolerance of
standardized values during the official sample test--although test
facility operational (e.g., cold-side fan settings) conditions would
remain identical to those set during the CTS test. ASTM C1199 also does
not require measurement of the warm-side surface temperature of the
door. Rather, this value is calculated based on the radiative and
convective heat flows from the test specimen's surface to the
surroundings, which are driven by values determined from the
calibration of the hot box using the CTS test (e.g., the convection
coefficient). See ASTM C1199, section 9.2.1.
As discussed in the April 2022 NOPR, DOE has found that obtaining
the standardized heat transfer values within the 5 percent
tolerance specified in section 5.3(a)(1) of appendix A on the
[[Page 28796]]
warm side and cold side may not be achievable depending on the thermal
transmittance through the door. 87 FR 23920, 23937. In the April 2022
NOPR, DOE proposed to remove the exceptions specified in section
5.3(a)(1) of appendix A regarding the surface heat transfer
coefficients and the tolerances on them during testing.
DOE did not receive any comments on its proposal to remove the
exceptions specified in section 5.3(a)(1) of appendix A.
For the reasons discussed in the preceding paragraphs and the April
2022 NOPR, DOE is removing the exceptions listed in section 5.3(a)(1)
of appendix A regarding the surface heat transfer coefficients and the
tolerances on them during testing. 87 FR 23920, 23937-23938. By
removing these exceptions, the requirements pertaining to the surface
heat transfer coefficients would apply as they are specified in the
referenced industry standards.
Relatedly, Anthony commented on the specific values used to define
the surface heat transfer coefficients. Specifically, Anthony commented
that it disagrees with the current surface heat transfer coefficient
applied to the cold side during testing and simulation of U-factors for
display doors. (Anthony, No. 31 at pp. 4-5) Anthony presented data from
field testing at several different public locations showing that the
actual measured wind speed is on average 84 percent less than specified
in NFRC 102-2020 and NFRC 100-2010, as well as a measured wind speed
from their test cell showing an average of 1.1 miles per hour
(``mph''). Anthony recommended that DOE adopt a cold-side heat transfer
coefficient corresponding to a conservative wind speed value of 5 mph.
Id.
DOE notes that deviating from the existing surface heat transfer
coefficients would require test labs to change their test chamber
calibration procedures and would require manufacturers to retest and
rerate all envelope components subject to the energy consumption test
procedure in appendix A. DOE has evaluated the data and information
provided by Anthony but is unable to establish at this time whether
such changes to the heat transfer coefficient would be nationally
representative, nor the extent to which any such improvement in
representativeness of the test result would outweigh the test burden
associated with changing the heat transfer coefficient value. DOE has
therefore determined it is not appropriate to amend the heat transfer
coefficients in this final rule.
Additionally, section 5.3(a)(1) of appendix A currently specifies a
direct solar irradiance \28\ of 0 Btu/h-ft\2\. Consistent with DOE's
removal of its reference to NFRC 100-2010, DOE is removing the
requirement of direct solar irradiance of 0 Btu/h-ft\2\ in section
5.3(a)(4) of appendix A. DOE received no comment on solar irradiance in
response to the April 2022 NOPR and notes that the removal of this
requirement would not affect measured values. 87 FR 23920, 23938.
---------------------------------------------------------------------------
\28\ Solar irradiance is the power per unit area received from
the sun in the form of electromagnetic radiation.
---------------------------------------------------------------------------
2. Additional Definitions
a. Surface Area for Determining Compliance With Standards
Surface area of a door is used in two ways in the regulations at
subpart R of 10 CFR431: (1) to convert the tested U-factor of the door
into a conduction load as part of the energy consumption test
procedure, and (2) to determine compliance with the maximum energy
consumption standards. As currently defined in section 3.4 of appendix
A, surface area means the area of the surface of the walk-in component
that would be external to the walk-in cooler or walk-in freezer as
appropriate. The definition does not provide detail on how to determine
the boundaries of the walk-in door from which height and width are
determined to calculate surface area. Additionally, the definition does
not specify if these measurements are to be strictly in-plane with the
surface of the wall or panel that the walk-in door would be affixed to,
or if troughs and other design features on the exterior surface of the
walk-in door should be included in the measured surface area.
In the April 2022 NOPR, DOE proposed that the surface area bounds
of both display doors and non-display doors be the outer edge of the
frame. 87 FR 23920, 23939. DOE proposed to change the term from
``surface area'' to ``door surface area,'' and to define the term as
meaning the product of the height and width of a walk-in door measured
external to the walk-in. Id. Under this definition, the height and
width dimensions would be perpendicular to each other and parallel to
the wall or panel of the walk-in to which the door is affixed, the
height and width measurements would extend to the edge of the frame and
frame flange (as applicable) to which the door leaf is affixed, and the
surface area of a display door and non-display door would be
represented as Add and And, respectively.
In addition, DOE proposed to move the defined term from the test
procedure in appendix A to the definition section in 10 CFR 431.302
with the other definitions that are broadly applicable to subpart R.
Id. DOE proposed this move because, as revised and in light of the
following section III.C.2.b of this document, this term would no longer
be used to convert the tested U-factor of the door into a conduction
load as part of the energy consumption test procedure and is only
relevant for determining compliance with the energy conservation
standards. Id.
Anthony agreed with the proposed revision of using the external
frame dimensions, which includes the flange, for determining
Add and for determining the maximum energy consumption
standard. (Anthony, No. 31 at p. 5)
Bally suggested that the surface area definition should include
electrical conduit and pressure relief vents, not pieces of the door
with low conductivity. (Bally, No. 40 at pp. 1-2) Bally also commented
that it disagrees with DOE's discussion in the April 2022 NOPR that if
the surface area of a door is measured without the frame, then it
should be considered a panel. (Id.) Senneca stated that the outside
dimensions of the frame should not be included in the surface area
measurement because the frame mounts directly to the insulated panel
and, therefore, the backside of the frame is not exposed directly to
the cold-side temperature. (Senneca, No. 26 at p. 2) Additionally,
Senneca described that a door with a longer track would require a
longer frame and therefore would have a larger surface area; however,
it stated that the larger frame would have no bearing on the energy
consumption because, as mentioned, the backside of the frame is not
exposed directly to the cold-side temperature. (Id.)
Senneca also stated that with the proposal for the door frame to be
included in the surface area, it believes there is ambiguity in
measuring sliding doors that have a track extending past the door
frame. (Id.) DOE has considered Senneca's comment specific to sliding
doors and acknowledges that the track of a horizontal sliding door may
extend significantly beyond the width of the door leaf and door frame
or casings and attach to the panels adjacent to the door, which would
result in a significant increase in ``door surface area'' if the track
width were to be included in the area measurement. Therefore, DOE has
concluded that the portion of the track that extends beyond the
external width (for a horizontal sliding door) or external height (for
a vertical sliding door) of the door leaf or
[[Page 28797]]
leaves and its frame or casings should be excluded from the surface
area measurement used to determine compliance with the standards. DOE
notes that given the equipment it is aware of on the market, this
additional instruction will likely only impact the bounds of sliding
non-display doors. DOE notes that sliding display doors typically have
tracks that are integrated completely into the frame of the entire door
system, thus the entire track is expected to be included in the
determination of surface area.
DOE has considered stakeholder opposition to including the frame in
the door surface area measurement but has determined that the
definition of ``door'' includes the frame for consistent comparison
across door products offered. DOE recognizes that non-display doors may
have variations in the frames used, where some look similar to panels
but tend to have electrical components wired through them, while others
look more like casings used in replacement installations. DOE also
recognizes that non-display doors may have variations in the
installation of doors, where parts of the door frame may or may not be
in direct contact with the cold side of the walk-in. However, DOE
intends to consistently evaluate different products and sees a need to
have consistent instructions on determining the bounds of surface area
for all walk-in doors. DOE has determined that all parts of the door
that impact the operation of the door shall be included in the
determination of the surface area, with the exception of extended track
area for sliding doors as discussed previously. Therefore, the bounds
of the ``door surface area'' dimensions also include the frame.
As proposed in the April 2022 NOPR, in this final rule, DOE is
defining ``door surface area'' as the product of the height and width
of a walk-in door measured external to the walk-in. The height and
width dimensions shall be perpendicular to each other and parallel to
the wall or panel of the walk-in to which the door is affixed. The
height and width measurements shall extend to the edge of the frame and
frame flange (as applicable) to which the door is affixed. For sliding
doors, the height and width measurements shall include the track;
however, the width (for horizontal sliding doors) or the height (for
vertical sliding doors) shall be truncated to the external width or
height of the door leaf or leaves and its frame or casings. The surface
area of a display door is represented as Add, and the
surface area of a non-display door is represented as And.
b. Surface Area for Determining U-Factor
As stated previously, appendix A currently references NFRC 100-
2010, which in turn references NFRC 102 for the determination of U-
factor through a physical test. When conducting physical testing, the
U-factor (Us) is calculated using projected surface area
(As) and then converted to the final standardized U-factor
(UST). See ASTM C1199, sections 8.1.3 and 9.2.7, as
referenced through NFRC 102. Projected surface area (As) is
defined as ``the projected area of test specimen (same as test specimen
aperture in surround panel).'' See ASTM C1199, section 3.3, as
referenced through NFRC 102.
Currently, equations 4-19 and 4-28 of appendix A specify that
surface area of display doors (Add) and non-display doors
(And), respectively, are used to convert a door's U-factor
into a conduction load. This conduction load represents the amount of
heat that is transferred from the exterior to the interior of the walk-
in.
As discussed in section III.C.2.a, DOE is amending the definitions
of And and Add to be specific to the exterior
dimensions of the door, including the frame and frame flange as
appropriate. Defining the bounds of the door through this definition is
inconsistent with the defined area (As) used to calculate U-
factor in NFRC 102-2020.
In the April 2022 NOPR, DOE proposed to specify that the projected
area of the test specimen, As, as defined in ASTM C1199, or
the area used to determine U-factor is the area used for converting the
standardized tested U-factor, UST, into a conduction load in
appendix A. 87 FR 23920, 23940. DOE recognizes that this may not change
ratings for some doors, where As is equivalent to
And or Add, but it may result in slightly lower
ratings of energy consumption for other doors, where As is
less than And or Add. DOE expects that since this
proposed detail would either result in a reduced measured energy
consumption or have no impact, there will likely be no need for
manufacturers to retest or rerate. Additional details on how this
detail impacts retesting and rerating are further discussed in section
III.K.1 of this document.
Anthony commented that it agrees with the proposed revision to use
the area of the test specimen, As, to calculate the
conduction load. (Anthony, No. 31 at p. 6) Bally reiterated comments
from AHRI, Hussmann, and Imperial Brown in response to the June 2021
RFI which suggested they did not see a distinction that warranted
changing the definition. (Bally, No. 40 at p. 1) See summary of these
comments at 87 FR 23920, 23939.
DOE reiterates that the door surface area defined in section
III.C.2.a differs from the surface area used to calculate U-factor in
NFRC 102-2020. Thus, despite stakeholder comments, DOE sees a need to
resolve this discrepancy. Otherwise, the conduction load determined
from the physical U-factor test may inflate the actual conduction load.
In the April 2022 NOPR, DOE also proposed to specify in appendix A
that the physical U-factor test should include all components of the
door that aid in the operation of the door, including the frame, rather
than just the door leaf, to improve consistency in application of the
test procedure across all walk-in doors. 87 FR 23920, 23940. Bally
commented that it does not believe the frame of the door should be
included in the U-factor test and suggested that including the frame in
the U-factor test was minimal in comparison to the electrical
components. (Bally, No. 40 at pp. 2-3) As stated in the April 2022
NOPR, DOE's testing of non-display doors has demonstrated that
including the frame in the U-factor test has a measurable impact on the
thermal performance of the door assembly relative to the increase in
the total area, and so DOE is adopting the specification that the
physical U-factor test should include the door frame.
3. Electrical Door Components
Sections 4.4.2 and 4.5.2 of appendix A currently include provisions
for calculating the direct energy consumption of electrical components
of display doors and non-display doors, respectively. Electrical
components associated with doors could include, for example, heater
wire (for anti-sweat or anti-freeze applications), lights (including
display door lighting systems), control system units, or sensors. For
each electricity consuming component, the calculation of energy
consumption is based on the component's ``rated power'' rather than a
measurement of its power draw. Section 3.5 of appendix A defines
``rated power'' as the electricity consuming device's power as
specified (1) on the device's nameplate or (2) on the device's product
data sheet if the device does not have a nameplate or such nameplate
does not list the device's power.
As discussed in the April 2022 NOPR, DOE has observed issues that
make calculating a door's total energy consumption a challenge. 87 FR
23920, 23940. These issues include using a
[[Page 28798]]
single nameplate for all door electrical components rather than
individual nameplates for all electricity-consuming devices,
specification of voltage and amperage rather than wattage on the
nameplate, and no specification of whether the nameplate represents the
maximum or steady-state operating conditions. DOE is aware that
measuring direct power consumption of each electrical component could
alleviate some of these issues. In response to the April 2022 NOPR, the
Efficiency Advocates stated that they support an option for direct
measurement of door component electrical power in the test procedure
(Efficiency Advocates, No. 37 at p. 4). DOE acknowledges the comment
but has concluded that additional investigation is needed to develop a
test procedure for such measurements. Therefore, DOE is not adopting
provisions requiring measurement of power consumption of each
electrical door component in appendix A.
Furthermore, DOE has observed that some manufacturers may be
certifying door motor power as the output power rating of the motor,
rather than the input power of the motor. Thus, DOE proposed in the
April 2022 NOPR to specify in appendix A that the rated power of each
electrical component, Prated,u,t, would be the rated input
power of each component because the input power represents power
consumption. The Efficiency Advocates also supported the clarification
that the certified door motor power should be the input power. Id.
Additionally, DOE has observed through testing that the measured
power of some walk-in door electrical components exceeds either the
certified or nameplate power values of these electrical components. In
the April 2022 NOPR, DOE proposed that for the purposes of enforcement
testing, in 10 CFR 429.134(q), DOE may validate the certified or
nameplate power values of an electrical component by measuring the
power when the device is energized using a power supply that provides
power within the allowable voltage range listed on the nameplate. If
the measured input power is more than 10 percent higher than the power
listed on the nameplate or the rated input power in a manufacturer's
certification, then the measured input power would be used in the
energy consumption calculation. For electrical components with
controls, the maximum input wattage observed while energizing the
device and activating the control would be considered the measured
input power. Anthony agreed with the proposal to use nameplate values
for determining energy consumption unless physical testing results in a
power value that exceeds what is depicted on the nameplate. (Anthony,
No. 31 at p. 6) Bally stated that adjusting nameplate values based on
measurement results requires door manufacturers to be responsible for
the quality assurance of their vendors. (Bally, No. 40 at p. 3) In
response, DOE notes that the door manufacturer is ultimately
responsible for certifying that the walk-in door, when outfitted with
all necessary components, meets the applicable DOE energy conservation
standards.
Given DOE's observations during testing, DOE sees a need to provide
a way to calculate energy consumption using a measured value of
electrical component power. DOE recognizes that there may be minor
variations in measured power as compared to the rated power and has
determined that a tolerance of 10 percent accounts for such variation.
DOE is adopting this provision at 10 CFR 429.134(q)(4) only for the
purposes of enforcement testing to aid the Department in determining
non-compliance with energy conservation standards.
4. Percent Time Off Values
The current test procedure assigns percent time off (``PTO'')
values to various walk-in door components to reflect the hours in a day
that an electricity-consuming device operates at its full rated or
certified power. PTO values are not incorporated in the rated or
certified power of an electricity-consuming device. Table III.2 lists
the PTO values in the current DOE test procedure for walk-in door
components.
Table III.2--Assigned PTO Values for Walk-In Door Components
------------------------------------------------------------------------
Percent time
Component type Off (PTO) (%)
------------------------------------------------------------------------
Lights without timers, control system, or other demand- 25
based control..........................................
Lights with timers, control system, or other demand- 50
based control..........................................
Anti-sweat heaters without timers, control system, or 0
other demand-based control.............................
Anti-sweat heaters on walk-in cooler doors with timers, 75
control system, or other demand-based control..........
Anti-sweat heaters on walk-in freezer doors with timers, 50
control system, or other demand-based control..........
All other electricity-consuming devices without timers, 0
control system, or other auto-shut-off system..........
All other electricity-consuming devices for which it can 25
be demonstrated that the device is controlled by a
preinstalled timer, control system, or auto-shut-off
system.................................................
------------------------------------------------------------------------
As mentioned in the April 2022 NOPR, DOE has granted waivers to
several door manufacturers with motorized door openers, allowing the
use of a different PTO for motors.\29\ 87 FR 23920, 23941. DOE proposed
a single PTO for use with door motors to create consistency in the test
procedure among doors with motors. 87 FR 23920, 23941-23942. DOE
calculated an average PTO value based on the information in the waivers
to determine a single representative PTO value. Considering the waivers
and its calculations, DOE proposed to adopt a door motor PTO value of
97 percent for all walk-in doors with motors. Id. Senneca and the
Efficiency Advocates agreed with the proposed PTO. (Senneca, No. 26 at
p. 2; Efficiency Advocates, No. 37 at p. 2) Bally suggested that the
power consumption of the motor be completely removed from the energy
consumption calculation, but ultimately supported the proposed PTO
value. (Bally, No. 40 at p. 3) DOE has determined that motor power
consumption contributes to direct and total energy consumption of the
door and aids in the operation of the door. Therefore, the motor power
should be included in the determination of energy consumption.
Additionally, pursuant to its waiver regulations, as soon as
practicable after the granting of any waiver, DOE will publish in the
Federal Register a notice of proposed rulemaking to amend its
regulations to eliminate any need for the continuation of such waiver.
10 CFR 431.401(l). For the reasons stated above, DOE is adopting the
PTO value of 97 percent
[[Page 28799]]
for door motors in appendix A. DOE notes that the adoption of this PTO
value would not require retesting or recertification because calculated
daily energy consumption will be equal to or lower than currently
certified values. New testing would only be required if the
manufacturer wishes to make claims using the new, more efficient
rating.
---------------------------------------------------------------------------
\29\ See HH Technologies, 83 FR 53457; Jamison Door Company, 83
FR 53460; Senneca Holdings, 86 FR 75; Hercules, 86 FR 17801.
---------------------------------------------------------------------------
5. Energy Efficiency Ratio Values
As discussed in the April 2022 NOPR, the energy efficiency ratio
(``EER'') values used in appendix A differ from the EER values in
appendix C. 87 FR 23920, 23942. The values in appendix A are used to
calculate the daily energy consumption associated with heat loss
through a walk-in door, and the values in appendix C correspond to
adjusted dew point temperature when testing refrigeration systems of
walk-in unit coolers alone. In the July 2021 RFI, DOE requested comment
on the difference in EER values used in appendices A and C and based on
stakeholder feedback, DOE concluded in the April 2022 NOPR that there
is no advantage to harmonizing the two values. Id. As discussed in the
April 2022 NOPR, an envelope component manufacturer cannot control what
refrigeration equipment is installed and the EER values are intended to
provide a nominal means of comparison rather than reflect an actual
walk-in installation. Additionally, the difference between the EER
values used in appendix A for doors and those used in appendix C for
unit coolers is seven percent for coolers and five percent for
freezers; however, changing the EER values would require manufacturers
to retest and rerate energy consumption without necessarily providing a
more representative test procedure. Id. Therefore, in the April 2022
NOPR, DOE did not propose to harmonize the EER values between
appendices A and C.
In response to the April 2022 NOPR, Anthony suggested that DOE
adopt the EER values specified in AHRI 1250 to align all components of
a WICF and stated that the modification of EER values would not require
additional testing, as these values are only used in the mathematical
energy calculations. (Anthony, No. 31 at pp. 6-7) DOE notes that
Anthony's suggested approach would require recalculation and
recertification of every basic model and would do so without
necessarily providing a more representative test procedure. As such,
DOE has determined that changing the reference EER values in either
appendix A or C would be unduly burdensome. Therefore, DOE is not
harmonizing the EER values in appendices A and C.
6. Air Infiltration Reduction
As discussed in the April 2022 NOPR, EPCA includes prescriptive
requirements for doors used in walk-in applications intended to reduce
air infiltration. 87 FR 23902, 23943. Specifically, walk-ins must have
(A) automatic door closers that firmly close all walk-in doors that
have been closed to within 1 inch of full closure (excluding doors
wider than 3 feet 9 inches or taller than 7 feet), and (B) strip doors,
spring-hinged doors, or other method of minimizing infiltration when
doors are open. (42 U.S.C. 6313(f)(1)(A)-(B)) DOE previously proposed
methods for determining the thermal energy leakage due to steady-state
infiltration through the seals of a closed door and door opening
infiltration. 75 FR 186, 196-197; 75 FR 55068, 55084-55085. DOE did not
ultimately adopt these methods as part of the final test procedure
because DOE concluded that steady state infiltration was primarily
influenced by on-site assembly practices rather than the performance of
individual components. 76 FR 21580, 21594-21595 (April 15, 2011).
Similarly, DOE stated that, based on its experience with the door
manufacturing industry, door opening infiltration is primarily reduced
by incorporating a separate infiltration reduction device at the
assembly stage of the complete walk-in. Id.
In the April 2022 NOPR, DOE did not propose to include air
infiltration in the test procedure. 87 FR 23920, 23943. However, the
Efficiency Advocates encouraged DOE to incorporate a measurement of air
infiltration for walk-in doors because it would improve the
representativeness and encourage the development and deployment of
technologies that can save energy. (Efficiency Advocates, No. 37 at p.
4) DOE did not receive any data or recommendations for how to
incorporate the measurement of air infiltration for walk-in doors into
the test procedure in response to either the June 2021 RFI or the April
2022 NOPR. DOE has concluded that additional investigation is needed to
adopt a test procedure that considers air infiltration for walk-in
doors and thus is not adopting provisions pertaining to air
infiltration at this time. DOE intends to consider data on the
magnitude of air infiltration for walk-ins as it becomes available for
appropriate evaluation of the representativeness of including it in the
test procedure for walk-in doors.
As previously mentioned, EPCA requires air infiltration limiting
devices on all doors. (42 U.S.C. 6313(f)(1)(A)-(B)) Even though air
infiltration is not currently evaluated as part of the current test
procedure and thus not part of the performance standard, all walk-in
doors are subject to the prescriptive requirements in the energy
conservation standard pertaining to air infiltration limiting devices.
(10 CFR 431.306(a)(1)-(2))
D. Amendments to Appendix A for Display Panels
Appendix A specifies the test procedure to determine energy
consumption of walk-in display panels, which are not currently subject
to any daily energy consumption performance standards but are subject
to the prescriptive requirements at 10 CFR 431.306. The existing test
procedure for walk-in display panels is very similar to that of walk-in
doors in that it requires a U-factor test using NFRC 100-2010, which is
used to determine the thermal conduction through the display panel and
ultimately the total daily energy consumption. The existing display
panel test procedure differs, however, from that of walk-in doors in
that direct and indirect electrical energy consumption are not included
in the test procedure.
In the April 2022 NOPR, DOE proposed to apply all the test
requirements proposed for determining display door conduction load and
energy consumption to determining display panel conduction load and
energy consumption, except for the provisions applicable to electrical
components and PTO values. 87 FR 23920, 23943.
Anthony agreed that the test procedure for display panels should be
similar to the test procedure for display doors, but it disagreed with
DOE's proposal that provisions applicable to electrical components and
PTO values should be excluded from the test procedure for display
panels. (Anthony, No. 31 at p. 7) Anthony stated that display panels
can have heaters and lights. (Id.)
DOE acknowledges Anthony's feedback regarding display panels;
however, DOE does not currently have sufficient information on display
panel electrical components and PTO values to adopt provisions for
electrical components for display panels. DOE may do so in a future
rulemaking, however at this time, DOE is adopting the changes to
section III.C of appendix A for determining display panel conduction
load and energy consumption as proposed in the April 2022 NOPR.
[[Page 28800]]
E. Amendments to Appendix B for Panels and Non-Display Doors
The insulation R-value of walk-in non-display panels and non-
display doors is determined using appendix B. In the April 2022 NOPR,
DOE proposed to modify appendix B to improve test representativeness
and repeatability. 87 FR 23920, 23943. Specifically, DOE proposed to
make the following revisions to appendix B: (1) reference the updated
industry standard ASTM C518-17; (2) include more detailed provisions on
measuring insulation thickness and test sample thickness; (3) provide
additional guidance on determining parallelism and flatness of test
specimen; and (4) reorganize appendix B so it is easier for
stakeholders to follow as a step-by-step test procedure. Id.
In response to the appendix B proposals, Bally commented that the
proposed regulations will be burdensome for laboratories to conduct.
(Bally, No. 40 at p. 4) DOE acknowledges Bally's comment; however, DOE
has concluded that the proposed amendments would not be unduly
burdensome and would improve test representativeness and repeatability
as discussed in sections III.E.1 through III.E.5 of this document. Test
procedure costs and impacts because of the adopted changes are further
discussed in section III.K.2 of this document. DOE does not expect that
the adopted changes to appendix B, discussed further, will alter
measured R-values; therefore, no retesting or recertification is
required.
Additionally, AHRI commented generally that they would like to
understand if display doors, non-display doors, and panels use the same
calculation. (AHRI, No. 30 at p. 4) DOE defines each of these
components separately (see subpart R of 10 CFR 431.302) and their
respective test procedures are described in appendix A, and appendix B.
The procedure for determining energy consumption of display doors
begins at section 4.4 of appendix A. The procedure for determining
energy consumption of non-display doors begins at section 4.5 of
appendix A. Sections 4.4 and 4.5 of appendix A follow the same
methodology of accounting for thermal conduction through the door
(represented in the form of additional refrigeration system energy),
the direct electrical energy consumption of electricity-consuming
devices sited on the door, and the indirect electrical energy
consumption of electricity-consuming devices represented in the form of
additional refrigeration system energy consumption. Panels not
classified as display panels follow the test procedure in appendix B,
which determines the R-value of insulation for only the foam of the
panel.
Furthermore, DOE clarifies that in the following sections, the
changes discussed are specifically in the context of walk-in panels;
however, DOE notes that non-display doors are also subject to the
prescriptive R-value requirement at 10 CFR 431.306(a)(3) and that the
R-value for walk-in door insulation is determined using appendix B. The
following sections describe the modifications that DOE is adopting in
appendix B.
1. 24-Hour Testing Window
As mentioned in the April 2022 NOPR, DOE is aware that the test
specimen and conditioning instruction and example given in section 7.3
of ASTM C518-04 and ASTM C518-17 conflict with the provision in section
4.5 of the DOE test procedure at appendix B. The DOE test procedure
requires testing be completed within 24 hours of specimens being cut
for the purpose of testing, while ASTM C518-04 and ASTM C518-17 require
that specimens be conditioned prior to testing based on material
specifications, which could be longer than 24 hours. 87 FR 23920,
23942.
Bally commented that a cut sample should not be exposed to air for
longer than 8 hours because foam samples become irreversibly de-
conditioned once removed from a panel. (Bally, No. 40 at pp. 3-4) Bally
included a technical bulletin from 1984 that states that, in general, a
1-inch cut section of foam can increase in K-factor about 5 to 10
percent in a few days. (Bally, No. 40, Attachment 2) \30\
---------------------------------------------------------------------------
\30\ The Bally comment included two supplemental attachments:
Attachment 1, ``Solid and Opaque Eval,'' and Attachment 2, ``BTB--
Aging of Foam.'' DOE will reference as ``Attachment 1'' and
``Attachment 2'' throughout this document. Both attachments are
available on the docket.
---------------------------------------------------------------------------
It is DOE's understanding that since the technical bulletin
referenced by Bally was published, there have been changes to the
blowing agents used in polyurethane foam, the most common foam
insulation type used in walk-in panels. Additionally, no specific data
on the change in K-factor beyond 8 hours was provided. Recent tests
conducted by DOE demonstrate that there is no measurable difference in
K-factor for specimens tested immediately after extraction from the
complete panel as compared to specimens tested 24 hours after
extraction from the complete panel. DOE has not evaluated changes to K-
factor of a test specimen beyond 24 hours of extraction from the panel.
Given the existing technology on the market today, DOE believes 24
hours is an appropriate limit that balances K-factor representativeness
with test burden, and therefore DOE is maintaining the current
requirement that testing be completed within 24 hours of cutting a test
specimen from the envelope component. Correspondingly, DOE is not
referencing Section 7.3 of ASTM C518-17 regarding specimen conditioning
as part of its update to appendix B.
2. Total Insulation and Test Specimen Thickness
Section 4.5 of appendix B currently requires that K-factor of a 1
0.1-inch sample of insulation be determined according to
ASTM C518-04.
To make the test procedure in appendix B more repeatable, DOE
proposed in the April 2022 NOPR to include instructions for determining
both the total insulation thickness as well as the test specimen
insulation thickness prior to conducting the test to determine K-factor
using ASTM C518-17, which is substantively the same as determining the
K-factor according to ASTM C518-04. 87 FR 23920, 23944. DOE also
proposed step-by-step instructions for specimen preparation, including
detailed instructions of the number and locations of thickness and area
measurements and from where the test specimen should be removed from
the overall envelope component. Id. DOE proposed to require the
following for determining the total thickness of the foam,
tfoam, from which the final R-value is calculated:
The thickness around the perimeter of the envelope
component is determined as the average of at least 8 measurements taken
around the perimeter that avoid the edge region.\31\
---------------------------------------------------------------------------
\31\ Edge region means a region of the panel that is wide enough
to encompass any framing members. If the panel contains framing
members (e.g., a wood frame), then the width of the edge region must
be as wide as any framing member plus an additional 2 in. 0.25 in. See section 3.1 of appendix B.
---------------------------------------------------------------------------
The area of the entire envelope component is calculated as
the width by the height of the envelope component.
A sample is cut from the center of the envelope component
relative to the envelope component's width and height. The specimen to
be tested using ASTM C518-17 will be cut from the center sample.
The thickness of the sample cut and removed from the
center of the envelope component is determined as the average of at
least 8 measurements, with at least 2 measurements taken in each
quadrant.
[[Page 28801]]
The area of the sample cut and removed from the center of
the envelope component is determined as the width by the height of the
cut sample.
Any facers on the sample cut from the envelope component
shall be removed while minimally disturbing the foam, and the thickness
of each facer shall be the average of at least 4 measurements.
The average total thickness of the foam shall then be
determined by calculating an area-weighted average thickness of the
complete envelope component less the thickness of the facers.
Id.
For preparing and determining the thickness of the 1-inch test
specimen, DOE proposed the following:
A 1 0.1-inch-thick specimen shall be cut from
the center of the cut envelope sample removed from the center of the
envelope component.
Prior to testing, the average of at least 9 thickness
measurements at evenly spaced intervals around the test specimen shall
be the thickness of the test specimen, L.
Id.
In the April 2022 NOPR, DOE requested feedback on the proposed
provisions relating to test specimen and total insulation thickness and
test specimen preparation prior to conducting the ASTM C518-17 test.
Anthony agreed with both of the proposals. (Anthony, No. 31 at p. 7)
Bally referenced the EPCA calculation for R-value and recommended that
R-value remain calculated with that formula. (Bally, No. 40 at p. 3)
Bally commented that it believes the tolerance of 1 0.1
inch is not necessary because the sample preparation process would need
to be restarted, but a smaller sample could have been used to determine
K-factor. (Bally, No. 40 at p. 4)
In response to Bally's comment, DOE is not adopting any changes to
the R-value formula; rather, DOE is providing additional instruction so
that the inputs to the R-value formula, namely the K-factor, are
determined in a consistent and more repeatable manner. At this time,
DOE has determined that the 1 0.1 inch tolerance is still
necessary to appropriately and consistently measure K-factor.
Therefore, DOE is adopting the provisions outlined in the April 2022
NOPR for determining test specimen and total thickness of insulation in
appendix B.
3. Parallelism and Flatness
The test procedure for determining R-value requires that the two
surfaces of the tested sample that contact the hot plate assemblies (as
defined in ASTM C518-04 and ASTM C518-17) maintain a flatness tolerance
of 0.03 inches and maintain parallelism of one another with
a tolerance of 0.03 inches.\32\ See section 4.5 of appendix
B. As discussed in the April 2022 NOPR, the current test procedure does
not provide direction to measure or calculate flatness and parallelism.
DOE believes, however, that accurate and repeatable determination of a
specimen's R-value requires the specimen under test to be both flat and
parallel. 87 FR 23920, 23944.
---------------------------------------------------------------------------
\32\ Maintaining a flatness tolerance means that no part of a
given surface is more distant than the tolerance from the ``best-fit
perfectly flat plane'' representing the surface. Maintaining
parallelism tolerance means that the range of distances between the
best-fit perfectly flat planes representing the two surfaces are no
more than twice the tolerance (e.g., for square surfaces, the
distance between the most distant corners of the perfectly flat
planes minus the distance between the closest corners is no more
than twice the tolerance).
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE proposed to include several steps for
determining the parallelism and flatness of the test specimen in
appendix B:
Prior to determining the specimen thickness, the specimen
would be placed on a flat surface and gravity used determine the
specimen's position on the surface. As specified previously, a minimum
of nine thickness measurements would be taken at equidistant positions
on the specimen. These measurements would be associated with side 1 of
the specimen.
The least squares plane of side 1 is determined based on
the height measurements taken. The theoretical height of the least
squares plane is determined at each measurement location in the x and y
(length and width) direction of the specimen.
The difference at each measurement location between actual
height measurement and theoretical height measurement based on the
least squares plane is calculated. The maximum value minus the minimum
value is the flatness associated with this side (side 1). For each side
of the specimen to be considered flat, this value would need to be less
than or equal to 0.03 inches.
Flip the specimen so that side 1 is now on the flat
surface and let gravity determine the specimen position on the surface.
Repeat the steps above for side 2 of the specimen.
To determine if each side of the specimen is parallel, the
theoretical height at the four corners (i.e., at points (0,0), (0,12),
(12,0), and (12,12)) of the specimen must be calculated using the least
squares plane. The difference in the maximum and minimum heights would
represent the parallelism of one side and would need to be less than or
equal to 0.03 inches for the specimen to be considered parallel.
87 FR 23920, 23945.
AHRI and Anthony agreed with the proposed provisions relating to
determining parallelism and flatness of the test specimen. (AHRI, No.
30 at p. 4; Anthony, No. 31 at p. 8) Bally stated that commercial
devices used to measure K-factor using ASTM C518 have an internal check
on flatness and parallelism so a sample that is out of tolerance will
be flagged. (Bally, No. 40 at pp. 4-5)
DOE acknowledges Bally's comment, however, it is DOE's
understanding that not all manufacturers or laboratories use the same
commercial device to measure K-factor. Regardless of the device used, a
consistent procedure for determining parallelism and flatness is
necessary. DOE is adopting the method for determining parallelism and
flatness in appendix B as described in the April 2022 NOPR. 87 FR
23920, 23945.
4. Insulation Aging
The current test procedure for determining panel R-value does not
account for insulation aging. ``Aging'' of foam insulation refers to
how diffusion of blowing agents out of the foam and diffusion of air
into the foam impacts thermal resistance of insulation materials. The
gaseous blowing agents contained in the foam provide it with much of
its insulating performance, represented by the R-value of the foam
material. Because air has a lower insulating value than the blowing
agents used in foam insulation, the increased ratio of air to blowing
agent reduces the foam insulation performance, which reduces the R-
value of the foam material over time. The building industry uses long-
term thermal resistance (``LTTR'') to represent the R-value of foam
material over its lifetime by describing the insulating performance
changes due to diffusion over time. The presence of impermeable facers
on a foam structure may delay the rate of aging or reduce the decrease
in R-value when compared to a foam structure that is unfaced or has
permeable facers. Blowing agents and temperature and humidity
conditions may also affect the amount or rate of aging that occurs in a
foam structure.
In the April 2022 NOPR, DOE discussed its previous adoption and
subsequent removal of a test procedure that considered aging of foam
insulation. 87 FR 23920, 23945-23946. DOE rescinded the method that
evaluated aging because of stakeholder concerns regarding test burden
and the availability of laboratories to conduct the adopted test
procedure. 79 FR 23788, 27405-27406. As such, DOE did
[[Page 28802]]
not propose to add test procedure provisions regarding aging in the
April 2022 NOPR. 87 FR 23920, 23945-23946. DOE also did not propose to
consider the effects of aging in assessment and enforcement testing
because a recent study at Oak Ridge National Laboratory (``ORNL'')
found the effects of foam insulation aging for panels sold with facers
to be minimal when panel facers remain attached to the foam (i.e., when
the panel remains intact).\33\ Id. In the April 2022 NOPR, DOE
requested comment on other comparable data or studies of foam panel
aging that are representative of the foam insulation, blowing agents,
and panel construction currently used in the manufacture of walk-in
panels. Id. DOE also requested comment on whether manufacturers have
been certifying R-value at time of manufacture or after a period of
aging. Id.
---------------------------------------------------------------------------
\33\ A presentation on ORNL's study can be found online at
www.osti.gov/biblio/1844325-impact-thermal-bridging-imperfections-agingeffective-value-walk-cooler-freezer-panels. DOE acknowledges
that panels are shipped for assembly in walk-ins with the foam
already in final chemical form between facers. Thus, the most
applicable evaluation of change in insulation R-value over time is
demonstrated by the red data points (labeled ``2'') for the foam
that remained intact with the facers on slides 26 through 30 of
ORNL's presentation.
---------------------------------------------------------------------------
In response, AHRI suggested that any aging criteria should be based
on the conditioning requirements in ASTM C518. (AHRI, No. 30 at p. 4)
AHRI also stated that typical aging periods to ensure dimensional
stability of finished foam has been reached vary between 14 and 28
days. Id. Bally stated that it tests its foam without aging. (Bally,
No. 40 at p. 5) RSG commented that it would like to limit the time
between manufacture and testing as much as possible. (RSG, No. 41 at
pp. 1, 11) RSG stated that it has conducted its own test, where it
calculated R-value every 2 weeks for 6 months after manufacture; it
found that R-value drops sharply at the beginning, followed by a slower
rate of decline. (Id.)
In response to AHRI's suggestion regarding aging criteria, DOE
testing has shown that there is no measurable difference in K-factor
for specimens tested immediately after extraction from the complete
panel as compared to specimens tested 24 hours after extraction from
the complete panel, even though it would be expected that aging of a
thinner sample without facers would be more significant than a fully
intact panel. Therefore, DOE expects the aging of an intact panel to be
negligible after 24 hours.
Bally's and RSG's comments suggest that manufacturers are rating R-
value without considering the effects of aging and would prefer to
limit the amount of time between manufacture and test. As stated
previously, DOE has found that there are minimal effects of foam
insulation aging for panels sold with facers when panel facers remain
attached to the foam. For assessment and enforcement testing conducted
to support the enforcement of DOE's energy conservation standards, DOE
is generally able to test samples within one to three months after
receipt. The time lag from when the panel is manufactured and when
testing is conducted at a laboratory is typically significantly shorter
than that evaluated in the ORNL study. Therefore, DOE expects any
reduction in R-value to be minimal from date of manufacture to
assessment or enforcement test date. Additionally, walk-in panels
received by DOE for assessment and enforcement testing are evaluated
upon arrival to ensure that they are received intact (i.e., with
facers) and undamaged, and testing of the specimen is completed within
24 hours of sample removal from the panel, as specified in section 4.5
of the DOE test procedure in appendix B. DOE does not expect any
reduction in R-value within 24 hours of the sample being cut from the
panel. Therefore, at this time, DOE will not consider insulation aging
in the test procedure nor in the Department's assessment and
enforcement testing based on the available data. DOE may consider
additional data on this issue as it becomes available.
5. Overall Thermal Transmittance of Non-Display Panels
The current test procedure for non-display panels does not measure
the overall thermal transmittance of a walk-in panel. 87 FR 23920,
23946. DOE previously adopted a test method for measuring overall
thermal transmittance of a walk-in panel, including the impacts of
thermal bridges \34\ and edge effects (e.g., due to structural
materials and fixtures used to mount cam locks). 76 FR 21580. However,
after receiving comments concerning test and cost burden and the lack
of availability of laboratories to conduct the test procedure, DOE
rescinded this portion of the walk-in panel test procedure. 79 FR
27388, 27405-27406. Based on past concerns, DOE did not propose any
provisions to evaluate overall thermal transmittance of non-display
panels in the April 2022 NOPR. 87 FR 23920, 23946.
---------------------------------------------------------------------------
\34\ Thermal bridging occurs when a more conductive material
allows an easy pathway for heat flow across a thermal barrier.
---------------------------------------------------------------------------
In response, the Efficiency Advocates encouraged DOE to investigate
appropriate methods to capture the overall thermal transmittance of
walk-in panels. (Efficiency Advocates, No. 37 at p. 4) DOE did not
receive any other feedback on its proposal or specific suggestions on
how to implement a procedure that would measure overall thermal
transmittance while minimizing the test cost burdens previously
identified.
DOE continues to have the same concerns regarding test burden and
lack of availability of test facilities to conduct any potential
overall thermal transmittance testing of walk-in panels. Therefore, DOE
is not including a test procedure in appendix B for determining overall
thermal transmittance of non-display panels at this time.
F. Amendments to Appendix C for Refrigeration Systems
Appendix C provides test procedures to determine the AWEF and net
capacity of walk-in refrigeration systems. DOE does not expect that the
adopted changes to appendix C will alter measured capacity values or
AWEF. Therefore, DOE expects no retesting or recertification will be
required. Rather, the revisions for appendix C address repeatability
issues that DOE has observed through its testing of walk-in
refrigeration systems.
The following sections describe the modifications that DOE is
making to appendix C, in this final rule.
1. Refrigeration Test Room Conditioning
The DOE test procedure for walk-in refrigeration systems specifies
temperature and/or humidity conditions for the test chambers. (See,
e.g., Tables 3 through 16 of AHRI 1250-2009, which is incorporated by
reference in the DOE test procedure.) Section C6.2 of AHRI 1250-2009
requires that the environmental chambers ``be equipped with essential
air handling units and controllers to process and maintain the enclosed
air to any required test conditions.'' This requirement is also in
section C5.2.2 of AHRI 1250-2020. However, DOE is aware that some test
facilities may rely on the test unit to cool and dehumidify the test
room. When the test unit is used to cool and dehumidify the test room,
frost accumulation on the test unit's coils during pretest conditioning
is possible and can affect the results of the capacity test. 87 FR
23920, 23947. Section C5.1 of AHRI 1250-2020 states that the unit
cooler under test may be used to aid in
[[Page 28803]]
achieving the required test chamber ambient temperatures prior to
beginning a steady-state test but requires the unit under test to be
free from frost before initiating steady-state testing. In the April
2022 NOPR, DOE proposed to specify that for applicable system
configurations (matched pairs, single-packaged systems, and unit
coolers tested alone), the unit under test may be used to help achieve
the required test chamber conditions prior to beginning any steady-
state test. 87 FR 23920, 23947. Additionally, DOE proposed to require a
visual inspection of the test unit coils for frost before the steady-
state test begins. Id. 87 FR 23920, 23947. DOE requested comment on the
proposed pretest coil inspection requirement and asked for feedback on
current chamber conditioning practices within the industry. 87 FR
23920, 23947.
AHRI, HTPG, Hussmann, KeepRite, Lennox, and National Refrigeration
disagreed with allowing the unit under test to condition the test room
because it cannot sufficiently remove humidity from the room. (AHRI,
No. 30 at p. 4; HTPG, No. 32 at p. 4; Hussmann, No. 38 at p. 3;
KeepRite, No. 36 at p. 1; Lennox, No. 35 at pp. 2-3; National
Refrigeration, No. 39 at p. 1) The same group of commenters also stated
that the requirement for the unit to be ``free from frost'' is too
subjective. (Id.) Hussmann mentioned that defrost could reduce the
frost present, but that would result in a frosted-coil test instead of
a dry-coil test. (Hussmann, No. 38 at p. 3) AHRI and Hussmann suggested
that, if the unit under test is used to condition the test chamber, the
unit's capacity be tested both before and after the test to ensure that
the unit's capacity is not decreasing due to frost load. (AHRI, No. 30
at pp. 4-5; Hussmann, No. 38 at p. 3) Lennox recommended that
environmental chambers be equipped with air handlers to maintain test
conditions. (Lennox, No. 35 at pp. 2-3) RSG agreed with the DOE's
proposed inspection requirement. (RSG, No. 41 at p. 1)
2. DOE notes that the proposed test procedure allows the unit under
test to aid in achieving the required test chamber conditions This
implies that other conditioning equipment may be necessary and that the
unit under test should never be the sole conditioner. In addition, DOE
notes that the amendments to test procedure are in alignment with
section C5 of AHRI 1250-2020, the most current industry test procedure.
DOE has determined that a visual inspection is the most practical way
to confirm that coils are free from frost and that while such an
inspection may include subjective judgement about the presence of
frost, it is better than no inspection at all. DOE has therefore
determined that a visual inspection of the coils is sufficient. DOE
also notes that the operating tolerances discussed in section III.F.5
of this document, appendix C to subpart R of 10 CFR part 431, and AHRI
420-2007 ensure that any significant impact of frost collection during
a test would invalidate the test unless the unit capacity remains
steady throughout a test.\35\ These requirements make the pre- and
post-test measurement of capacity unnecessary. Therefore, DOE is
adopting the test procedure as proposed in the April 2022 NOPR. DOE is
adding the new requirement to appendix C, which also carries over to
appendix C1. Temperature Measurement Requirements
---------------------------------------------------------------------------
\35\ For dedicated condensing units and matched pairs, new mass
flow operating tolerances are adopted as discussed in section
III.F.5, and existing refrigerant temperature tolerances are
specified in section 3.1.1 of appendix C to subpart R of 10 CFR part
431. These two measurements would drift out of tolerance during a
test if frost conditions were significantly affecting capacity
measurements for such systems. Similarly, table C3 of AHRI 420-2007
includes a refrigerant mass flow tolerance and table C4 of AHRI 420-
2007 includes inlet and outlet saturation temperature operating
tolerances. These measurements would drift out of tolerance during a
test if frost conditions were significantly affecting capacity
measurements of unit coolers tested alone.
---------------------------------------------------------------------------
a. Suction Line Temperature Measurement
The current DOE test procedure requires measuring refrigerant
temperature entering or leaving the unit cooler using either
thermometer wells or immersed sensors to determine refrigerant enthalpy
as part of the capacity measurement for matched pairs and unit coolers
tested alone (see 10 CFR part 431, subpart R, appendix C, section
3.2.1). The capacity determination for dedicated condensing units
tested alone is based on the refrigerant conditions leaving the
condensing unit and standardized conditions leaving the unit cooler, as
specified in section 3.4.2.1 of appendix C. In the April 2022 NOPR, DOE
proposed to clarify that, when testing dedicated condensing units,
thermometer wells or immersed sensors can be used only at the
condensing unit liquid outlet and are not required to be used for the
suction line. 87 FR 23920, 23947.
AHRI, KeepRite, Lennox, National Refrigeration, and HTPG all
commented that they do not support the proposal to forgo temperature
measuring requirements for the suction line when testing dedicated
condensing units. (AHRI, No. 30 at p. 5; KeepRite, No. 36 at p. 1;
Lennox, No. 35 at p. 3; National Refrigeration, No. 39 at p. 1; HTPG,
No. 32 at p. 4) AHRI also stated that legacy calculation and simulation
systems use existing temperature measurements of the suction discharge.
(AHRI, No. 30 at p. 5)
DOE acknowledges that existing systems and calculations may depend
on suction line temperature measurements. For this reason, DOE retracts
its proposal from the April 2022 NOPR and in this final rule maintains
the requirements for thermometer wells or immersed sensors for both the
suction and liquid lines when testing dedicated condensing units alone.
AHRI-Wine also commented that wine cellar manufacturers are
concerned that the wells are not large enough for temperature
measurements. (AHRI-Wine, No. 30 at p. 2) DOE notes that thermometer
wells are required in the current DOE test procedure for temperature
measurement. DOE addresses these concerns in the remainder of this
section.
b. Surface-Mount Temperature Measurement Allowances for Small Diameter
Tubing
As mentioned in the April 2022 NOPR, DOE has found that
implementing the current thermometer well requirement for refrigerant
lines with an outer diameter of 1-2 inch or less can restrict the
refrigerant flow and thus affect temperature measurements. To rectify
this issue and to ensure that all walk-in refrigeration systems can be
tested according to the DOE test procedure, DOE proposed allowing an
alternative approach when the refrigerant line tubing diameter is 1-2
inch or less, in which the temperature measurement would be made using
two surface-mounted measuring instruments with a minimum accuracy of
0.5 [deg]F, which would be averaged to obtain the reading.
Additionally, DOE proposed that the two measuring instruments must be
mounted on the pipe separated by 180 degrees around the refrigerant
tube circumference. To ensure
[[Page 28804]]
measurements are not affected by changes in ambient temperature, DOE
proposed requiring use of 1-inch-thick insulation around the measuring
instruments that extends 6 inches up- and downstream of the measurement
locations. Where this technique is used to measure temperature at the
expansion valve inlet, DOE proposed to require that the measurement be
within 6 inches of the device.
With respect to tube surface measurements, AHRI and KeepRite stated
that the temperature measurements on the tube surface are not accurate
enough, and that this measurement is too critical to allow this. (AHRI,
No. 30 at p. 5; KeepRite, No. 36 at p. 1) AHRI and KeepRite also stated
that a low-temperature reading resulting from surface-mounted
temperature measurement devices could lead to bubbling upstream of the
expansion valve, resulting in inflated AWEF values. (AHRI, No. 30 at p.
5; KeepRite, No. 36 at p. 2) Lennox supported DOE's proposal to allow
surface-mounted temperature sensors but encouraged DOE to work with
industry to ensure the full scope of applications can be covered with
these requirements. (Lennox, No. 35 at p. 3) Additionally, AHRI and
KeepRite suggested allowing transition to a pipe large enough for a
thermometer well. Id. National Refrigeration also recommended
maintaining the thermometer well requirement for small diameter tubing
and allowing for larger diameter tubing to accommodate thermometer
wells. (National Refrigeration, No. 39 at p. 1) Regarding location of
the temperature measurement, AHRI and KeepRite agreed with the
allowance to locate the temperature sensor within 6 inches; however,
they suggested that the test procedure should further clarify if the
measurement is from the body of the expansion valve or the joint with
the liquid line. (AHRI, No. 30 at p. 5; KeepRite, No. 36 at p. 2)
KeepRite further suggested allowing the dual liquid temperature
measurements to be further upstream in a thermometer well with a
secondary surface measurement 6 inches from the expansion valve and
with sufficient insulation such that the surface temperature reading
does not differ by more than 2 [deg]F from the thermometer well
measurements. (KeepRite, No. 36 at p. 2)
Specific to the liquid line temperature measurement location, DOE
clarifies that the measurement is from the center of the body of the
expansion valve.
AHRI-Wine and HTPG agreed with the proposal to allow two external
temperature measurements for small diameter tubing. (AHRI-Wine, No. 30
at p. 2; HTPG, No. 32 at p. 4)
DOE acknowledges the concerns from stakeholders regarding the use
of surface measurements and will consider data from industry on this
issue in future rulemakings. DOE has conducted testing using the
approach proposed in the April 2022 NOPR and has determined that the
approach provides representative measurements and prevents bubbling.
Therefore, DOE is adopting the surface mount temperature measurement
test provisions as proposed in the April 2022 NOPR. These requirements
will be added to appendix C, and will also carry over to appendix C1.
3. Hierarchy of Installation Instruction and Specified Refrigerant
Conditions for Refrigerant Charging and Setting Refrigerant Conditions
As discussed in the April 2022 NOPR, DOE is aware that sometimes
multiple installation instructions may be available for a unit, and
different test results could be obtained based on which instructions
are used. 87 FR 23920, 23948. DOE proposed a hierarchy for installation
instructions and setup of refrigerant conditions to improve test
repeatability by indicating which manufacturer-specified conditions
would be prioritized during setup.
Setup conditions or instructions may be stamped on the unit
nameplate or otherwise affixed to the unit, shipped with the unit, or
available online. DOE has encountered walk-in refrigeration units for
which these three sources of instruction provide different values or
conflicting directions. To ensure consistent setup during testing, DOE
proposed in the April 2022 NOPR that instructions or conditions stamped
on or adhered to a test unit take precedence, followed by instructions
shipped with the unit. Id. Because online instructions can be easily
revised, DOE proposed that instructions or other setup information
found online would not be used to set up the unit for testing.
Furthermore, setting of refrigerant charge level or refrigerant
conditions is a key aspect of setup of refrigeration systems, whether
for field use or testing. In the April 2022 NOPR, DOE proposed that
units be charged and set up at operating conditions specified in the
test procedure (for outdoor refrigeration systems, DOE proposed use of
operating condition A) based on the installation instructions, using
the proposed hierarchy (i.e., prioritizing instructions stamped or
adhered to unit over instructions included in a manual shipped with the
unit). Id. In cases where instructions for refrigerant charging or
refrigerant conditions are provided only online or not at all, DOE
proposed that a generic charging approach be used instead. If the
installation instructions specify operating conditions to set up the
refrigerant charge or refrigerant conditions, those conditions would be
used rather than the conditions specified in the test procedure. Id.
DOE determined that in some cases, a manufacturer specifies a range
of conditions for superheat,\36\ subcooling, and/or refrigerant
pressure. In these instances, DOE proposed to treat the midpoint of
that range as the target temperature/pressure, and a test condition
tolerance would be applied to the parameter that is equal to half the
range. For example, if a manufacturer specifies a target superheat of 5
to 10 [deg]F, the target for test would be 7.5 [deg]F and the average
value during operation at the setup operating conditions would have to
be 7.5 [deg]F 2.5 [deg]F. Alternatively, installation
instructions may specify a refrigerant condition value without a range
or without indicated tolerances. In such cases, DOE proposed that
standardized tolerances be applied as indicated in Table III.3. These
tolerances depend on the kind of refrigerant expansion device used.
---------------------------------------------------------------------------
\36\ Superheat is the difference between vapor-phase refrigerant
temperature and the dew point corresponding to the pressure level.
[[Page 28805]]
Table III.3--Test Condition Tolerances and Hierarchy for Refrigerant Charging and Setting of Refrigerant
Conditions
----------------------------------------------------------------------------------------------------------------
Fixed orifice or capillary tube Expansion valve
----------------------------------------------------------------------------------------------------------------
Priority Method Tolerance Priority Method Tolerance
----------------------------------------------------------------------------------------------------------------
1.................. Superheat....... 2.0 1.................. Subcooling...... 10% of the
[deg]F. target value;
no less than
0.5
[deg]F, no more
than 2.0
[deg]F.
2.................. High Side 4.0 2.................. High Side 4.0
Pressure or psi or 1.0 Saturation minus>1.0
Temperature. [deg]F. Temperature. [deg]F.
3.................. Low Side or 2.0 3.................. Superheat....... 2.0
Saturation psi or 0.8
[deg]F.
4.................. Low Side 2.0 4.................. Low Side 2.0
Temperature. [deg]F. Pressure or psi or 0.8
Temperature. [deg]F.
5.................. High Side 2.0 5.................. Approach 1.0
Temperature. [deg]F. Temperature. [deg]F.
6.................. Charge Weight... 2.0 6.................. Charge Weight... 0.5% or 1.0 oz.,
oz.. whichever is
greater.
----------------------------------------------------------------------------------------------------------------
DOE also notes that zeotropic \37\ refrigerants have become more
common. When charging with such refrigerants (i.e., any 400 series
refrigerant), DOE proposed that the refrigerant charged into the system
must be in liquid form. 87 FR 23920, 23948. Charging a system in liquid
form is standard practice for charging of such refrigerants because the
concentrations of the components of the blend present in the vapor
phase of the charging cylinder are often skewed from the intended
concentrations of the refrigerant blend.
---------------------------------------------------------------------------
\37\ A zeotropic refrigerant is a blend of two or more
refrigerants that have different boiling points. Each refrigerant
will evaporate and condense at different temperatures.
---------------------------------------------------------------------------
If the installation instructions on the label affixed to (or
shipped with) the unit do not provide instructions for setting
subcooling or otherwise how to charge with refrigerant for a condensing
unit tested alone or as part of a matched pair, DOE proposed requiring
testing the unit in a way that is consistent with the DOE test
procedure and the installation instructions and that also does not
cause the unit to stop operating during testing, e.g., by shutoff by
the high-pressure switch. DOE believes that such installation would be
most representative of the way a technician would set up a system in
the field if there were no refrigerant charge or subcooling
instructions. 87 FR 23920, 23948.
AHRI and Lennox commented that they agree with the hierarchy of
charging methods, however, they recommended that DOE allow use of
online documentation. (AHRI, No. 30 at p. 6; Lennox, No. 35 at p. 3)
HTPG also suggested that electronic instructions be allowed in addition
to paper. (HTPG, No. 32 at p. 5)
As discussed previously, DOE proposed in the April 2022 NOPR not to
permit online instruction manuals in part because they can be easily
revised. In consideration of these stakeholder comments, DOE has
determined to allow use of online instruction manuals, with certain
restrictions. Firstly, online instructions can be used only if no
instructions or conditions are stamped on or adhered to a test unit or
shipped with the unit. Secondly, to prevent revision to online
documentation once a unit has been shipped by the manufacturer, online
instruction manuals must include a version number or version date on
the unit label or in the documents that are packaged with the unit.
In this final rule, DOE is amending the test procedure such that
setup instructions or conditions stamped on or adhered to a test unit
take precedence, followed by instructions shipped with the unit,
followed by online instructions if the version number or date of the
online instruction manual is referenced on the unit label or is
included in documents that are packaged with the unit.
AHRI and Lennox recommended that outdoor units should be charged
for condition C, not condition A. (AHRI, No. 30 at p. 6; Lennox, No. 35
at p. 4) DOE has considered the commentors' recommendations and
validated this charging procedure through testing. DOE is therefore
amending the test procedure such that units be charged and set up at
operating conditions specified in the test procedure (for outdoor
refrigeration systems, operating condition C) based on the installation
instructions, using the hierarchy summarized in Table III.3 of this
document. DOE notes that many outdoor condensing units achieve head
pressure control that uses valves to ``flood'' the condenser with
liquid refrigerant to maintain sufficiently high condensing temperature
when outdoor air is cold. If such a condensing unit has insufficient
charge, it will be more obvious during operation in condition C (where
head pressure control is generally active) since more charge would be
in the condenser during such operation under head pressure control.
Hence, DOE concludes that charging in the C condition rather than the A
condition is appropriate for dedicated condensing systems (dedicated
condensing units, matched systems, and single-packaged dedicated
systems) that use a flooded condenser design. DOE has encountered units
that, when charged at the C condition, will not operate at the A
condition with the same charge weight due to high pressure cut out.
This suggests the possibility that following the charging instructions
may lead to two different charge weights depending on the condition
used for charging. DOE maintains that it is not representative of field
operation to use different refrigerant charge weights for the two test
conditions, since it is not expected that refrigerant charge would be
adjusted as ambient temperature rises and falls for a dedicated
condensing system in the field. As such, DOE is adopting test
provisions such that if a dedicated condensing system is charged at the
C condition but does not operate at the A condition due to excess
charge causing high pressure cut out, then refrigerant charge shall be
adjusted to the highest charge that allows operation at the A
condition. To limit the test burden of determining this highest charge,
the determination shall be subject to a stepwise charge adjustment.
Specifically, refrigerant would be removed in increments of 4 ounces or
5
[[Page 28806]]
percent of the system's receiver capacity, whichever is larger, until
operation at the A condition is possible. All tests, including those at
condition C, will then be performed with this refrigerant charge.
DOE notes that when conducting the C condition test for a dedicated
condensing system for which this charge removal has occurred as
described above, it is possible that the refrigerant leaving the system
no longer has measurable subcooling. If the measured subcooling of the
refrigerant leaving the condenser is less than 0 [deg]F, its state
cannot accurately be determined based on the measurement. The most
direct way to determine the state of the refrigerant would be to
provide additional cooling to the liquid line after it leaves the
condensing unit using a flow of a fluid such as water such that the
water mass flow and temperature rise would be measured and such that
the refrigerant is subcooled downstream of this heat exchange. Such an
approach would allow determination of the enthalpy at the condensing
unit exit as the enthalpy of its subcooled downstream state plus the
additional cooling provided divided by the mass flow. However, DOE has
determined that such an approach would require a chilled water, a
refrigerant water heat exchanger, a water flow meter, temperature
sensors, and provisions for flow and temperature measurements to be
captured by the data acquisition system. DOE has determined that this
additional equipment and time required to set up the additional
equipment represent an inappropriate increase in test burden. DOE has
finalized the test procedure requiring that if the calculated
subcooling at the condensing unit exit is less than 0 [deg]F, the
liquid at this location will be assumed to be at saturated liquid
conditions. DOE has determined that the departure from saturated
conditions is likely to be small. Additionally, this change in
calculation method would only take place at one of the three test
points. These two factors would lead to very little, or no, influence
over the final measured AWEF. Further, this would only be necessary
when testing units using refrigerant enthalpy-based test methods.
DOE notes that it is also possible for dedicated condensing systems
to maintain condensing temperature for low ambient operating conditions
using fan controls rather than condenser flooding. Units that use fan
control to maintain condenser temperature would not require
significantly more refrigerant charge when operating at the C condition
compared to the A condition. However, the fan controls of these systems
may cause instability in refrigerant conditions at the lower ambient
temperatures at the C test condition. As such, DOE has determined that,
for dedicated condensing systems that exclusively use fan controls to
maintain condensing temperature at low ambient temperatures, charging
at the A condition is more appropriate than charging such units at C
condition. The refrigerant charging proposals in the April 2022 NOPR
sought to minimize test burden while ensuring the repeatability and
representativeness of walk-in refrigeration system testing.
Stakeholders correctly pointed out that charging at the A test
condition would not be representative for systems with flooded-
condenser head pressure control. Thus, the change to charging at the C
test condition was necessary. However, DOE has determined through
testing that it is possible that when such a system is charged under
test condition C, it could fail to operate due to high pressure cutout
when operating under test condition A. Therefore, in order to ensure
that a valid test can be conducted, DOE is adding the additional
provisions. DOE believes these amendments are consistent with the
intent of proposed changes in the April 2022 NOPR while being
responsive to stakeholder feedback. Hence, DOE concludes that charging
in the C condition rather than the A condition is appropriate.
HTPG stated that it agrees that the unit under test should be set
up according to a hierarchy of conditions. HTPG further stated,
however, that it was unclear on the rationale for the inclusion and
priority of ``High Side Pressure or Saturation Temperature,'' ``Low
Side Pressure or Saturation Temperature,'' ``Approach Temperature,''
and ``Charge Weight'' in Table III.3. (HTPG, No. 32 at p. 5) HTPG did
not provide detail on why these parameters should not be included, or
otherwise reprioritized, in the hierarchy. DOE has developed the
hierarchy summarized in Table III.3 based on its own testing experience
and has observed that these parameters are specified operating
conditions for certain units. Through that testing DOE has determined
that the priority and inclusion of the methods listed in Table III.3
are appropriate.
Lennox stated that hierarchies in tables 1 and 19 should specify
dew vs. bubble point to remove confusion with high-glide refrigerants.
(Lennox, No. 35 at p. 4) DOE interprets Lennox's comment to be in
reference to Table III.3 in this document, which in the proposed
regulatory text was table 1 of appendix C (see 87 FR 23290, 24000-
24001) and table 19 of appendix C1, respectively (see 87 FR 23920,
24021). DOE acknowledges that the proposed test procedure hierarchy did
not clarify whether the dew or the bubble point should be used when the
saturation point is specified. However, this should be addressed in the
manufacturer's installation instructions, not specified by the test
procedure. To clarify the intent in the hierarchy, DOE is adding a note
in table 1 of appendix C and table 19 of appendix C1 to indicate that
saturation temperature can refer to either bubble or dew point
calculated based on a measured pressure, or a coil measurement, as
specified by the installation instructions. DOE is adopting this
clarification in this final rule.
AHRI, on behalf of wine cellar manufacturers, KeepRite, and
National Refrigeration agreed with the charging hierarchy. (AHRI-Wine,
No. 30 at p. 2; KeepRite, No. 36 at p. 2; National Refrigeration, No.
39 at p. 1)
DOE received no comment on the remaining proposals discussed in
this section. In this final rule, DOE is adopting the testing hierarchy
instructions proposed in the April 2022 NOPR into appendix C, and will
also carry these provisions over to appendix C1.
a. Dedicated Condensing Unit Charging Instructions
For dedicated condensing units tested alone, subcooling is the
primary setup condition. In the April 2022 NOPR, DOE proposed that if
the dedicated condensing unit includes a receiver and the subcooling
target leaving the condensing unit provided in the installation
instructions cannot be met without fully filling the receiver, the
subcooling target would be ignored. 87 FR 23920, 23948. Likewise, if
the dedicated condensing unit does not include a receiver and the
subcooling target leaving the condensing unit cannot be met without the
unit cycling off on high pressure, the subcooling target would be
ignored. Also, if no instructions for charging or for setting
subcooling leaving the condensing unit are provided in the installation
instructions, DOE proposed that the refrigeration system would be set
up with a charge quantity and/or exit subcooling such that the unit
operates during testing without shutdown (e.g., on a high-pressure
switch) and operation of the unit is otherwise consistent with the
requirements of the test procedure and the installation instructions.
[[Page 28807]]
DOE received no comments in response to the proposals discussed in
this section. In this final rule, DOE is adopting the dedicated
condensing unit charging instructions proposed in the April 2022 NOPR
into appendix C, and will also carry these provisions over to appendix
C1.
b. Unit Cooler Setup Instructions
For unit coolers tested alone, superheat is the primary setup
condition. Most WICF refrigeration systems use either thermostatic or
electronic expansion valves (``EEVs'') that respond either mechanically
or through a controller to adjust valve position to control for
superheat leaving the unit cooler. If the unit under test is shipped
with an adjustable expansion device, DOE proposed in the April 2022
NOPR that this would be the primary method to adjust superheat. 87 FR
23920, 23948. However, DOE has encountered units with expansion devices
that are not adjustable or where the expansion device does not provide
a sufficient adjustment range to achieve the superheat target. If the
expansion valve associated with the unit under test reaches its limit
before the superheat target is met, the specified superheat may not be
met within the specified tolerance. In this case, DOE proposed in the
April 2022 NOPR that the expansion valve should be adjusted to obtain
the closest match to the superheat target. Id. DOE has also encountered
unit coolers with inappropriate expansion devices. When this occurs,
DOE proposed in the April 2022 NOPR that any expansion device specified
for use with the unit cooler in manufacturer literature may be used for
the purposes of DOE testing. Id.
In the April 2022 NOPR, DOE also proposed that an operating
tolerance would not apply to superheat. Hence, if the system expansion
valve control fluctuates (i.e., if so-called ``hunting'' occurs, in
which the valve position, temperatures, and/or pressures are unsteady),
it would not invalidate a test. 87 FR 23920, 23948-23949. However, if
the fluctuation is so great that a valid test cannot be performed
(i.e., any individual measurement of superheat during the test is zero
or less), or if the operating tolerances for measurements that would be
affected by expansion device hunting are exceeded (mass flow, pressure
at the unit cooler exit, evaporator temperature difference),\38\ the
test procedure would allow for deviation from the installation
instructions. DOE proposed in the April 2022 NOPR that deviation from
the installation instructions would be at the discretion of the test
laboratory and could include replacing the expansion device with a
different expansion device that does not need to be listed in
installation instructions, adjusting the expansion device to provide an
average superheat that is greater than the target superheat, or both.
87 FR 23920, 23949.
---------------------------------------------------------------------------
\38\ Evaporator temperature difference (TD) is the difference in
temperature between the entering air and the refrigerant dew point
of the exiting refrigerant.
---------------------------------------------------------------------------
If the unit's installation instructions do not include setting
superheat for a unit cooler tested alone or as part of a matched pair,
DOE proposed in the April 2022 NOPR that the target superheat would be
6.5 [deg]F, the same value required in such circumstances in AHRI 1250-
2020 (see Tables 16 and 17 of AHRI 1250-2020). Id.
AHRI commented that unit cooler charging should be done based on
the expansion valve controlled by the room, not the supplied expansion
valve. (AHRI, No. 30 at p. 6) Lennox stated that it is industry
practice to test unit coolers with EEVs, because use of these valves
eliminates ``hunting'' and is more reliable. (Lennox, No. 35 at p. 4)
HTPG stated that it disagrees with the proposal in the April 2022 NOPR
that operating tolerance would not apply to superheat and believes it
conflicts with AHRI 1250-2020, as well as Table III.3. (HTPG, No. 32 at
p. 5) \39\
---------------------------------------------------------------------------
\39\ DOE held an ex parte meeting with Lennox and HTPG to
clarify these comments. See Docket No. EERE-2017-BT-TP-0010-0043.
---------------------------------------------------------------------------
After consideration, DOE has determined that using the expansion
valve supplied with the unit cooler is most appropriate for testing
because it most closely represents field performance. DOE notes that
the expansion device provided with the unit cooler or specified in the
unit cooler installation instructions may result in hunting behavior
and may fluctuate outside the specified tolerances for superheat.
Nevertheless, these results are expected to be more representative of
field performance than using a laboratory controlled EEV that provides
steady operation. As discussed in the preceding paragraphs, the amended
test procedure provides test laboratories with alternatives if the
expansion devices shipped with the unit, or specified in the
installation instructions, result in hunting that interferes with test
measurement tolerances.
DOE is aware that industry test practices are not currently
consistent with this approach. As such, DOE recognizes that testing
unit coolers with the expansion device shipped with the unit may
require manufacturers to retest and recertify their unit cooler basic
models. DOE is therefore not adopting the unit cooler expansion device
requirements proposed in the April 2022 NOPR in appendix C. DOE is
instead adopting those provisions only in appendix C1, which would be
required for demonstrating compliance with any future amended WICF
energy conservation standards. Manufacturers would therefore have
additional time to retest and recertify unit cooler basic models
impacted by these requirements.
c. Single-Packaged Dedicated System Setup and Charging Instructions
DOE has identified multiple setup issues while testing single-
packaged dedicated systems. Compared to split refrigeration
systems,\40\ single-packaged dedicated systems have less adjustment
flexibility due to lack of controls. Additionally, while many single-
packaged dedicated systems are marketed as ``fully charged,'' DOE has
found that many of its test units were undercharged.
---------------------------------------------------------------------------
\40\ ``Split refrigeration systems'' refer to systems made up of
a condensing unit and a unit cooler that are connected by
refrigerant lines and are not contained in a single housing. Split
refrigeration systems could be field-matched condensing units and
unit coolers or condensing units and unit coolers sold as matched
pairs.
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE proposed that one or more pressure
gauges (depending on the number of conditions that require a pressure
measurement for validation) should be installed during setup according
to the manufacturer's installation instructions to evaluate the charge
of the unit under test and to accurately measure setup conditions. 87
FR 23920, 23949. The location of the pressure gauge(s) would depend on
the test setup conditions given in the installation instructions. If
charging is based on subcooling or liquid pressure, DOE proposed that
the pressure gauge(s) would be installed at the service valve of the
liquid line. If charging is based on superheat, low side pressure, or a
corresponding saturation temperature or dew point temperature, DOE
proposed that the pressure gauge(s) would be placed in the suction
line. 87 FR 23920, 23949.
DOE is aware that installation instructions for some single-
packaged dedicated systems recommend against installing charging ports;
however, DOE has observed through testing that some such units that
recommend against installing charging ports do not operate once
installed due to high- or low-pressure compressor cut off, which is
often a symptom of under- or over-charging or refrigerant loss. These
units are representative of what a contractor
[[Page 28808]]
would encounter when installing a walk-in single-packaged dedicated
system in the field. Therefore, in cases where a unit under test is not
operating due to high- or low-pressure compressor cut off, DOE proposed
in the April 2022 NOPR that a charging port should be installed, the
unit should be evacuated, and the nameplate charge should be added. 87
FR 23920, 23949. This approach would eliminate under- or over-charging
of the unit which would address compressor cut off.
DOE received no comments in response to the proposals in this
section. In this final rule, DOE is adopting the single-packaged
dedicated system setup instructions proposed in the April 2022 NOPR
into appendix C, and will also carry these provisions over to appendix
C1.
d. Hierarchy of Setup Conditions if Manufacturer-Specified Setup
Conditions Cannot Be Met
In DOE's experience, even when all the previously discussed
measures are implemented during test setup, some manufacturer-specified
setup conditions may not be met. In this case, DOE proposed in the
April 2022 NOPR that the unit under test be set up according to a
hierarchy of conditions like those used for central air-conditioning
systems and heat pumps. 87 FR 23920, 23949. First, the installation
instruction hierarchy previously discussed in section III.F.3 would be
applied. Specifically, if a refrigerant-related setup instruction in
the installation instructions affixed to the unit and a different
instruction in the installation instructions shipped with the unit
cannot both be achieved within tolerance, the instruction on the label
takes precedence. Further, if multiple instructions within the relevant
installation instructions cannot be met, the proposed hierarchy
outlined in Table III.3 would be applied. The highest priority
condition that can be satisfied, based on Table III.3, would need to be
met, depending on what kind of expansion device the system uses. This
approach would ensure that units are set up consistently across testing
facilities, ensuring more consistent results.
DOE received no comments in response to this proposal. In this
final rule, DOE is adopting the hierarchy of setup conditions proposed
in the April 2022 NOPR into appendix C, and will also carry these
provisions over to appendix C1.
4. Subcooling Requirement for Mass Flow Meters
Section C3.4.5 of AHRI 1250-2009 requires that refrigerant be
subcooled to at least 3 [deg]F and that bubbles should not be visible
in a sight glass immediately downstream of the mass flow meter. Section
3.2.3 of appendix C allows use of the sight glass and a temperature
sensor located on the tube surface under the insulation to verify
sufficient subcooling. DOE testing has shown that even when the
subcooling requirement is met downstream of the mass flow meter, the
liquid temperature can be warmer upstream. This difference results in
less subcooling, and mass flow measurements may not provide capacity
within the required tolerances (i.e., within 5 percent of each other
\41\ as required by section C8.5.3 of AHRI 1250-2009). 87 FR 23920,
23950. In the April 2022 NOPR, DOE proposed to include additional
instruction to section 3.2.3 of appendix C, to ensure fully liquid flow
at the mass flow meter. Id.
---------------------------------------------------------------------------
\41\ Section C8.5.3 of AHRI 1250-2009 requires that the two
refrigerant-side gross capacities calculated based on the two sets
of independent temperature, pressure, and mass flow measurements are
within 5 percent of each other to ensure adequate subcooling. In the
absence of adequate subcooling, the two refrigerant-side gross
capacities may not be within 5 percent of each other due to
disagreement in the mass flow readings.
---------------------------------------------------------------------------
First, DOE proposed that the 3 [deg]F subcooling requirement be
applied at a location dependent on the location of the liquid-line mass
flow meters. Id. Specifically, the proposed requirement applies
downstream of any mass flow meter located in the chamber that contains
the condensing unit under test, consistent with AHRI 1250-2009.
However, for mass flow meters located in the chamber that contains the
unit cooler under test, subcooling would need to be verified upstream.
In the April 2022 NOPR, DOE requested comments on its proposal to
clarify the location where the 3 [deg]F subcooling requirement would
apply. Id.
AHRI stated that the proposal to clarify the location where the 3
[deg]F subcooling applies may be sufficient in most, but not all,
cases. (AHRI, No. 30 at p. 6) AHRI, KeepRite, and National
Refrigeration recommended measuring temperature before and after the
mass flow meter and calculating subcooling using the higher of the two
temperatures with the pressure downstream of the meter to guarantee
fully liquid flow. (AHRI, No. 30 at p. 6; KeepRite, No. 36 at p. 2;
National Refrigeration, No. 39 at p. 2)
HTPG recommended insulating the flow meter and line set to
guarantee fully liquid flow. (HTPG, No. 32 at p. 5) HTPG also
recommended that for dedicated condensing unit testing, the temperature
measurement should be made before the flow meter inlet and for unit
cooler testing, temperature measurement should be taken after the flow
meter outlet. Id.
Lennox and RSG agreed with DOE's proposal to clarify the subcooling
condition measurement location. (Lennox, No. 35 at p. 4; RSG, No. 41 at
p. 2)
DOE notes that, assuming the mass flow meters are in the same room
as the dedicated condensing unit, insulating the flow meter and line
set may or may not help ensure fully liquid flow, depending on whether
the temperature surrounding the line set and flow meter are higher or
lower than the liquid temperature. DOE agrees that HTPG's
recommendation for measuring the subcooling before and after the mass
flow meters may provide a more rigorous approach for ensuring adequate
subcooling throughout the flow meter than the procedure proposed by DOE
in the April 2022 NOPR. However, during testing, DOE has found that the
subcooling measurement locations proposed in the April 2022 NOPR ensure
adequate subcooling through the mass flow meters with reduced test
burden. Therefore, DOE is adopting the subcooling measurement locations
as proposed in the April 2022 NOPR. DOE is adding the new requirements
to appendix C, and will also carry these provisions over to appendix
C1.
Second, DOE proposed that active cooling of the liquid line may be
used to achieve the required subcooling, because the subcooling at the
mass flow meter outlet may not meet the 3 [deg]F requirement when the
subcooling at the condensing unit exit is within tolerance of its
target. However, DOE also proposed requiring that if active cooling is
done when testing a matched pair (not including single-packaged
dedicated systems), the temperature also must be measured upstream of
the location where cooling is provided, and the temperature used to
calculate the enthalpy of the refrigerant entering the unit cooler be
increased by the difference between the upstream and downstream
measurements. DOE proposed this adjustment so that active cooling of
the liquid to obtain a mass flow measurement does not provide a non-
representative boost in calculated cooling capacity.
In the April 2022 NOPR, DOE sought comment on its active subcooling
and capacity calculation adjustment proposals. 87 FR 23920, 23950. In
response, AHRI and KeepRite recommended adjusting test results for
[[Page 28809]]
active cooling based on suction pressure when testing matched pairs.
(AHRI, No. 30 at p. 6; KeepRite, No. 36 at p. 2) KeepRite additionally
stated that active subcooling should be constrained to prevent
excessive subcooling and to obtain consistent results. (KeepRite, No.
36 at p. 2) KeepRite also recommended additional testing to determine
best practices for an active subcooling system and presented some
possible best practices. (KeepRite, No. 36 at p. 3) RSG agreed with
DOE's proposal to require adjustment of the measured unit cooler for
active cooling. (RSG, No. 41 at p. 2)
DOE acknowledges these comments and is making the following
adjustments to the final test procedure to address stakeholder
concerns. Instead of requiring an enthalpy adjustment if active
subcooling is used, DOE is requiring that, if active subcooling is
used, the line must be reheated such that the refrigerant is at the
same temperature as it was upstream of the active subcooling device.
This approach allows recording of an accurate mass flow measurement
with no impact on the measured capacity of the unit under test. DOE is
adopting the rest of the test procedures allowing active subcooling as
proposed in the April 2022 NOPR. DOE is adding the new requirements to
appendix C, and will also carry these provisions over to appendix C1.
5. Instrument Accuracy and Test Tolerances
The current DOE test procedure references AHRI 1250-2009 for
instrument accuracy and test tolerances with some modifications (see 10
CFR part 431, subpart R, appendix C, section 3.1). As discussed in the
April 2022 NOPR, some tolerances and instrumentation accuracy
requirements in AHRI 1250-2020 are not consistent with the current DOE
test procedure. 87 FR 23920, 23950. Specifically, DOE proposed to adopt
the following changes from AHRI 1250-2020 into appendix C:
Change the measurement accuracy for the temperature of air
entering or leaving either the evaporator or condenser from 0.25 [deg]F.
Replacing the ASHRAE 23.1 refrigerant mass flow operating
tolerance of 1 percent of the quantity measured with an
operating tolerance of 3 pounds per hour (``lb/h'') or 2 percent of the
reading (whichever is greater).
DOE did not receive comment on these proposals in the April 2022
NOPR. In this final rule, DOE is adopting the proposed changes from
AHRI 1250-2020 into appendix C. These changes are not expected to
impact measured values. DOE is adding the new requirements to appendix
C, and will also carry these provisions over to appendix C1.
6. CO2 Unit Coolers
As discussed in the April 2022 NOPR, CO2 behaves
differently than other refrigerants, as it has a critical temperature
of 87.8 [deg]F.\42\ Ambient temperatures greater than 87.8 [deg]F are
common, and the performance of many refrigeration and air-conditioning
systems are tested using a 95 [deg]F ambient temperature, as indicated
by the A test condition in Section 5 of AHRI 1250-2009 (and AHRI 1250-
2020). At temperatures greater than the critical temperature, the
CO2 refrigerant is in a supercritical state. Since useful
cooling is provided below the critical temperature, CO2
cycles are said to be transcritical.
---------------------------------------------------------------------------
\42\ All refrigerants have a ``critical pressure'' and an
associated ``critical temperature'' above which liquid and vapor
phases cannot coexist. Above this critical point, the refrigerant
will be a gas and its temperature will increase or decrease as heat
is added or removed.
---------------------------------------------------------------------------
DOE has granted test procedure waivers to the manufacturers listed
in Table III.1 of this document for certain basic models of walk-in
refrigeration systems that use CO2 as a refrigerant.
Manufacturers requesting a waiver from the DOE test procedure for
CO2 unit coolers stated that the test conditions described
in Tables 15 and 16 of AHRI 1250-2009, as incorporated by appendix C,
with modification, cannot be achieved by, and are not consistent with
the operation of, CO2 direct expansion unit coolers. The
alternate test procedure provided in these waivers modifies the test
condition values to reflect typical operating conditions for a
transcritical \43\ CO2 booster system. Specifically, the
waiver test procedures require that CO2 unit cooler testing
is conducted at a liquid inlet saturation temperature of 38 [deg]F and
a liquid inlet subcooling temperature of 5 [deg]F.
---------------------------------------------------------------------------
\43\ CO2 refrigeration systems are transcritical
because the high-temperature refrigerant that is cooled by ambient
air is in a supercritical state, above the 87.8 [deg]F critical
point temperature, above which the refrigerant cannot exist as
separate vapor and liquid phases.
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE proposed to adopt in appendix C (and
also in appendix C1), the alternate test conditions specified in the
waivers that DOE granted for CO2 transcritical unit coolers
for all CO2 unit coolers. Also, consistent with the waiver
alternate test procedure, DOE proposed that the EER values in Table 17
of AHRI 1250-2009 (or Table 18 of AHRI 1250-2020 for appendix C1) be
used to determine the AWEF of all CO2 unit coolers. 87 FR
23920, 23952. DOE requested comment on the appropriateness of
traditional refrigerant compressor EER values for use in CO2
unit cooler AWEF calculations. Id.
AHRI, HTPG, Hussmann, Lennox, and National Refrigeration all agreed
with the proposal. (AHRI, No. 30 at p. 7; HTPG, No. 32 at p. 5;
Hussmann, No. 38 at p. 6; Lennox, No. 35 at p. 4; National
Refrigeration, No. 39 at p. 2) DOE is adopting the test procedure as
proposed in the April 2022 NOPR for CO2 unit coolers and
adding the new requirements to appendix C, and will also carry these
provisions over to appendix C1.
7. High-Temperature Unit Coolers
As discussed in the April 2022 NOPR, DOE is aware of wine cellar
(high-temperature) refrigeration systems that fall within the
definition of ``walk-in'' but are unable to be tested under the current
version of the walk-in test procedure due to their operation at a
temperature range of 45 [deg]F to 65 [deg]F. 87 FR 23920, 23952. Most
of the high-temperature refrigeration systems that DOE is aware of are
either single-packaged dedicated systems or matched pairs. However, DOE
has granted an interim waiver for high-temperature unit coolers that
are distributed into commerce without a paired condensing system.\44\
---------------------------------------------------------------------------
\44\ DOE granted an interim waiver to LRC Coil Company for
specific basic models of unit cooler-only walk-in wine cellar
refrigeration systems on August 26, 2021. 86 FR 47631. (See also
EERE-2020-BT-WAV-0040, No. 1.) In reviewing another petition for
waiver and interim waiver from Vinotheque for single-packaged system
and matched pair system basic models (Vinotheque, EERE-2019-BT-WAV-
0038, No. 6), DOE noted that the manufacturer also offered unit
cooler-only systems distributed without a paired condensing system.
---------------------------------------------------------------------------
Under the current test procedure, these unit cooler-only models
would be tested according to the provisions in the test procedure for
unit coolers tested alone, for which the AWEF calculation requires an
appropriate EER. DOE has determined that the EER values for medium- and
low-temperature unit coolers tested alone are not appropriate for high-
temperature applications because this equipment operates with a
different suction dew point temperature, and the dedicated condensing
units typically paired with medium- and low-temperature units likely
use different compressor designs, which would have different
efficiencies.
As discussed in the April 2022 NOPR, DOE calculated representative
compressor EER levels for wine cellar walk-in unit coolers based on
compressor performance data collected by DOE. 87 FR 23920, 23953. DOE
used
[[Page 28810]]
the calculated compressor EER levels to develop different functions of
EER for three distinct capacities, as summarized in Table III.4.
Table III.4--EER Values for High-Temperature Compressors as a Function
of Capacity for High-Temperature Refrigeration Systems
------------------------------------------------------------------------
Capacity (Btu/hr) EER (Btu/(W-h))
------------------------------------------------------------------------
<10,000................................... 11.
10,000-19,999............................. (0.0007 x Capacity) + 4.
20,000-36,000............................. 18.
------------------------------------------------------------------------
The LRC Coil interim waiver includes additional test procedure
provisions to obtain representations that are representative for high-
temperature unit coolers, including both testing requirements and AWEF
calculation requirements. 86 FR 47631. These include provisions for
testing ducted fan coil unit evaporator systems. 86 FR 47631, 47635.
In the April 2022 NOPR, DOE proposed to include provisions for
testing high-temperature unit coolers in appendix C. 87 FR 23920,
23953. These provisions, consistent with the LRC Coil interim waiver,
would include conditions for testing these unit coolers at high-
temperature refrigeration conditions, as well as the EER values in
Table III.4 for calculation of AWEF. DOE also proposed to include these
provisions in appendix C1 in the April 2022 NOPR. Id. AHRI-Wine agreed
with DOE's inclusion of high-temperature unit cooler; however, they are
concerned with the suitability of the test provisions and AWEF
criteria. (AHRI-Wine, No. 30 at p. 2)
DOE notes that high-temperature unit coolers have the same function
as medium- and low-temperature unit coolers, however, their suction dew
point temperature differs, and counterpart-dedicated condensing units
may use high-temperature compressors designed for higher temperatures.
Therefore, DOE has concluded that the same test procedure can be used
for low-, medium- and high- temperature unit coolers, as long as the
EER values presented in Table III.4 are used for high-temperature
operation. After consideration of stakeholder comments, DOE is adopting
the test procedure provisions for high-temperature unit coolers as
proposed in the April 2022 NOPR. DOE is adding the new requirements to
appendix C, and will also carry these provisions over to appendix C1.
AHRI also stated that rating high-temperature unit coolers alone
without a method to rate high-temperature dedicated condensing units
disadvantages matched pairs and single-packaged dedicated systems.
(AHRI, No. 30 at p. 2) DOE will evaluate standards for high-temperature
equipment, including any appropriate equipment classes, in the ongoing
walk-in energy conservation standards rule making. DOE's evaluation of
the wine cellar market indicates that specific high-temperature
dedicated condensing units are rarely, if ever, sold outside of
matched-pair configurations. The dedicated condensing units DOE has
encountered that are sold outside of a matched-pair configuration and
that may be used in high-temperature applications are general-purpose
condensing units often marketed for medium- and high-temperature, or
only medium-temperature applications. Based on the definition of walk-
in coolers (i.e., medium-temperature refrigeration systems; see 10 CFR
431.302), DOE has determined that the dedicated condensing units used
for high-temperature applications are medium-temperature dedicated
condensing units. As such, these units do not need to be certified for
high-temperature applications but do need to be certified for medium-
temperature applications.
G. Establishing Appendix C1 for Refrigeration Systems
In the April 2022 NOPR, DOE proposed to establish a new appendix C1
to subpart R of part 431, which would be required to demonstrate
compliance coincident with the compliance date of any amended energy
conservation standards that DOE may promulgate as part of a separate
standards rulemaking. 87 FR 23920, 23953.
As the changes included in appendix C1 are expected to change
measured values for walk-ins, DOE is establishing a new annual walk-in
efficiency factor metric, AWEF2, that will replace the current metric,
AWEF, once appendix C1 is required for use. In many cases, AWEF2 of a
given refrigeration system will not be the same as AWEF. For any
amended energy conservation standards that DOE may promulgate as part
of a separate standards rulemaking, the standards will be set based on
AWEF2.
While AHRI 1250-2009 provides a method for determining off-cycle
fan power, AHRI 1250-2020 includes off-cycle power measurement for
additional auxiliary components (e.g., crankcase heaters, pan heaters,
and controls). AHRI 1250-2020 also adds test procedures that allow for
the testing of single-packaged dedicated systems and account for the
thermal loss of these systems. Taking into consideration the additions
just described, DOE has determined that AHRI 1250-2020 improves
representativeness and expands the applicability of the walk-in
refrigeration system test procedure. Additionally, DOE test procedures
strive to be consistent with industry test methods. As AHRI 1250-2020
is the most recent revision to the industry test procedure for walk-in
refrigeration systems, it is the best representation of current
industry testing practices. Therefore, DOE is incorporating AHRI 1250-
2020 by reference into its test procedure at appendix C1 for walk-in
refrigeration systems.
The test procedure changes that DOE is adopting as a part of
appendix C1 are discussed in the following sections.
1. Off-Cycle Power Consumption
For walk-in refrigeration systems, the term ``off-cycle'' refers to
the period when the compressor is not running and defrost (if
applicable) is not active. During off-cycle, unit cooler fans and other
auxiliary equipment (crankcase heater, receiver heater, etc.) \45\ may
typically run or cycle on and off, consuming energy. The DOE test
procedure currently accounts for only unit cooler fan energy use during
the off-cycle period. 10 CFR part 431, subpart R, appendix C, section
3.3.3. Specifically, the current test procedure requires manufacturers
to measure the integrated average off-cycle fan wattage \46\ for
matched pairs and unit coolers tested alone. Dedicated condensing units
tested alone use default fan energy values rather than tested values.
10 CFR part 431, subpart R, appendix C, section 3.4.2.2. When
calculating AWEF, the unit cooler fans are assumed to run at this
average integrated wattage throughout the entire off-cycle duration.
Id.
---------------------------------------------------------------------------
\45\ A crankcase heater prevents refrigerant migration and
mixing with the crankcase oil when the compressor is off by heating
the crankcase of the compressor. A receiver heater warms refrigerant
in the receiver to prevent flooded starts of the compressor and
cycling on low pressure to reduce the potential for compressor
damage. Both heaters are used for outdoor dedicated condensing units
in colder climates.
\46\ Fans using periodic stir cycles are tested at the greater
of a 50 percent duty cycle or the manufacturer's default. Fans with
two-, multi-, or adjustable-speed controls are tested at the greater
of 50% fan speed or the manufacturer's default fan speed. Fans with
no controls are tested at their single operating point. (See 10 CFR
part 431, subpart R, appendix C, section 3.3.3.)
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE discussed the recommendation of the
ASRAC Working Group (Docket No.
[[Page 28811]]
EERE-2015-BT-STD-0016, No. 56,\47\ Recommendation #6) to revise the
off-cycle test procedure to account for all other components that
consume energy during the off-cycle, such as pan heaters, crankcase
heaters, and controls. 87 FR 23920, 23953. DOE noted that AHRI 1250-
2020 includes a method for determining energy consumption during off-
cycle for many of these components. Id.
---------------------------------------------------------------------------
\47\ Appliance Standards and Rulemaking Federal Advisory
Committee Refrigeration Systems Walk-in Coolers and Freezers Term
Sheet, available at www.regulations.gov/document/EERE-2015-BT-STD-
0016-0056.
---------------------------------------------------------------------------
DOE is adopting the off-cycle procedure in sections C3.5, C4.2, and
Table C3 in AHRI 1250-2020 with some modifications. The following
sections describe DOE's modifications to the off-cycle test method and
metric in more detail.
a. Off-Cycle Test Duration and Repetition
The current DOE test procedure references the 30-minute off-cycle
test duration prescribed in section C3.6 of AHRI 1250-2009. AHRI 1250-
2020 was updated to include two off-cycle test durations: (1) 30
minutes for evaporator fans and ancillary equipment with controls that
are time-varying or respond to ambient or refrigerant temperatures
(e.g., a crankcase heater or fan cycling control), and (2) 5 minutes
for evaporator fans and ancillary equipment without such controls.
DOE has concluded that these durations balance the need to minimize
test burden with the need for an accurate and representative test
method. In the April 2022 NOPR, DOE proposed to reference these test
durations. 87 FR 23920, 23954.
AHRI 1250-2020 also added two sets of test repetition requirements:
one for evaporator fans and ancillary equipment with controls that are
time-varying or respond to ambient or refrigerant temperatures (e.g., a
crankcase heater or fan cycling control), and one for evaporator fans
and ancillary equipment without such controls. For the former, AHRI
1250-2020 requires that the off-cycle test for each applicable load
point \48\ consists of three initial test cycles, with the potential
for three supplemental cycles. As discussed in the April 2022 NOPR,
AHRI 1250-2020 only requires the three supplemental tests if the
integrated power of the first three cycles is not within 2 percent of
the average of the first three cycles. 87 FR 23920, 23954. If the same
variation occurs for the supplemental test cycles, then AHRI 1250-2020
requires that off-cycle power be reported as the maximum value of all
six integrated power readings. Alternatively, for equipment lacking
evaporator fans and ancillary equipment controls, AHRI 1250-2020
requires measuring integrated power over a single cycle. A summary of
test durations and fan settings based on fan control configuration and
ancillary equipment control configuration is listed in Table III.5.
---------------------------------------------------------------------------
\48\ Off-cycle load points are discussed later in this section.
Table III.5--Off-Cycle Test Settings and Durations
----------------------------------------------------------------------------------------------------------------
Ancillary equipment
Fan control configuration control configuration Fan setting for test Test duration
----------------------------------------------------------------------------------------------------------------
No Control......................... No Control............ Default setting, as shipped 5 minutes.
No Control......................... With Control.......... Default setting, as shipped 30 minutes.
User-Adjustable Speed Controls..... No Control............ The greater of 50% fan 5 minutes.
speed or the
manufacturer's default fan
speed.
User-Adjustable Speed Controls..... With Control.......... The greater of 50% fan 30 minutes.
speed or the
manufacturer's default fan
speed.
User-Adjustable Stir Cycles........ With or Without The greater of a 50% duty The greater of 30
Control. cycle or the manufacturer minutes or three full
default.. ``stir cycles.''
Non-User Adjustable Controls....... With or Without Default setting, as shipped 30 minutes.
Control.
----------------------------------------------------------------------------------------------------------------
DOE has concluded that the repetition requirements specified by
AHRI 1250-2020 are adequate and not overly burdensome. If the variance
is small among the first three cycles, then the testing burden is
reduced by not requiring any more cycles. If variance exceeds 2 percent
of the average when three additional cycles are taken, then the
conservative approach is taken by reporting the maximum integrated
power reading, and test burden is reduced by not requiring additional
tests. In the April 2022 NOPR, DOE proposed to adopt the repetition
requirements included in AHRI 1250-2020. 87 FR 23920, 23954.
In response to the off-cycle test durations and repetitions
proposed in the April 2022 NOPR, the Efficiency Advocates stated that
they supported updating off-cycle testing to include a unit's total
input wattage. (Efficiency Advocates, No. 37 at p. 1) Lennox supported
DOE proposals regarding off-cycle test duration and repetition.
(Lennox, No. 35 at pp. 4-5) In this final rule, DOE is adopting the
off-cycle test duration and repetition test procedures as proposed.
b. Off-Cycle Operating Tolerances and Data Collection Rates
In the April 2022 NOPR, DOE proposed to adopt Section C3.5 of AHRI
1250-2020 to establish off-cycle data collection requirements in the
DOE test procedure. 87 FR 23920, 23955. AHRI 1250-2020 excludes the
first 10 minutes that follow the termination of the compressor on-cycle
interval from the general operating tolerances (indoor/outdoor
temperatures and power readings) established for the on-cycle steady
state test because during this time period, the test room conditioning
equipment is transitioning from steady state on-cycle operation into
off-cycle operation.
Additionally, AHRI 1250-2020 requires that the minimum data
collection rate be increased (with respect to steady-state
requirements) from 30 to 60 test readings per hour for temperature
measurements and condensing unit electric power measurements, and from
3 to 60 test readings per hour for unit cooler electric power
measurements. AHRI 1250-2020 also requires that off-cycle power
measurements be integrated and averaged over the recording interval
with a sampling rate of no less than 1 second unless an integrating
watt/hour meter is used.
In response to the April 2022 NOPR, Lennox commented that it
supports DOE's off-cycle power measurement proposals but requested
clarification on
[[Page 28812]]
unit cooler ``steady-state ambient conditions,'' specifically whether
35 [deg]F and -10 [deg]F for unit cooler refers to air entering dry-
bulb in Tables 16 and 17 of AHRI 1250-2020. (Lennox, No. 35 at pp. 4-5)
DOE clarifies that the unit cooler ``steady-state ambient conditions''
of 35 [deg]F and -10 [deg]F refer to the entering air dry-bulb
temperatures of medium-temperature and low-temperature unit coolers,
respectively. DOE did not receive any additional comments on this topic
and is adopting section C3.5 of AHRI 1250-2020 for off-cycle operating
tolerances and data collection requirements, as proposed.
c. Off-Cycle Load Points
Currently, the DOE test procedure specifies measuring off-cycle
evaporator fan power and provides no ambient condition detail; however,
DOE expects that the integrated power of ancillary equipment may vary
with ambient conditions depending on the refrigeration system design.
Consequently, in the April 2022 NOPR, DOE proposed that the off-cycle
power test described in section III.G.1.a of this document be run at
each steady-state ambient test condition as specified in Tables 4
through 17 of AHRI 1250-2020. 87 FR 23920, 23955. Accordingly, DOE
proposed that refrigeration systems with dedicated condensing units
located indoors would evaluate off-cycle power at a single outdoor
ambient condition (90 [deg]F dry-bulb), while systems with dedicated
condensing units located outdoors would determine off-cycle power at
three ambient conditions (95 [deg]F, 59 [deg]F, and 35 [deg]F dry-
bulb). The measured integrated off-cycle power results would then be
used to calculate AWEF2, as described in the following section.
In response to the April 2022 NOPR, KeepRite commented that the
benefit from additional off-cycle power tests is minimal, capturing
less than 1 percent of total system energy. (KeepRite, No. 36 at p. 3)
DOE acknowledges that off-cycle power tests account for significantly
less energy consumption than on-cycle tests. However, DOE's testing
using the three ambient temperature off-cycle load points in AHRI 1250-
2020 has measured up to 60 percent more off-cycle power use than the
off-cycle power measurements in the current test procedure. This result
indicates that the current test procedure does not fully represent off-
cycle power use for walk-in refrigeration systems.
HTPG disagreed with the additional off-cycle testing requirement
proposed in the April 2022 NOPR (HTPG, No. 32 at p. 6) and stated that
it would increase test burden. (HTPG, No. 32 at p. 8) AHRI-Wine stated
that they expect the change related to off-cycle power measurement
requirements will increase test burden. (AHRI-Wine, No. 30 at p. 3) DOE
acknowledges that adopting the off-cycle power measurements in AHRI
1250-2020 may incrementally increase test time. However, in its
testing, DOE has found that conducting off-cycle power measurements
accounts for less than 10 percent of the overall setup and test
duration for walk-in refrigeration systems.
Lennox stated that using a single condition to measure off-cycle
power may not be sufficient for indoor matched systems. (Lennox, No. 35
at p. 5) Lennox also recommended working with industry to establish
running conditions for equipment that is not part of a matched pair.
Id. DOE notes that the number and specified conditions of off-cycle
tests correspond to the number and specified conditions of the
refrigeration capacity tests that are run for each unit. Outdoor units
have three capacity tests and three ambient conditions to represent the
three ambient conditions that the unit would be exposed to, therefore
they have three off-cycle tests. Indoor units have one capacity test at
one ambient condition that the unit would be exposed to, therefore they
have one off-cycle test. The ambient conditions inside the walk-in box
do not fluctuate and therefore one ambient condition is representative
for both on-cycle and off-cycle tests. DOE has concluded that this is
the most appropriate approach to balance test procedure consistency and
test burden.
DOE is adopting the off-cycle test points for (1) the A test
specified in AHRI 1250-2020 for fixed-capacity refrigerator and freezer
matched-pair and dedicated condensing units located indoors, (2) the A,
B, and C tests specified in AHRI 1250-2020 for refrigerator and freezer
matched-pair and dedicated condensing units located outdoors, and (3)
the A test specified in AHRI 1250-2020 for refrigerator and freezer
unit coolers. DOE clarifies that a single off-cycle test is
representative for both split-system unit coolers and indoor matched
systems.
d. AWEF2 Calculations
In the April 2022 NOPR, DOE proposed to adopt the off-cycle
calculations in AHRI 1250-2020, which replace integrated off-cycle
evaporator fan power with the combined integrated off-cycle power from
the unit cooler and condensing unit in each equation. 87 FR 23920,
23955. Additionally, DOE proposed to adopt the off-cycle calculations
in AHRI 1250-2020, which replace integrated off-cycle fan power with
integrated off-cycle power in the unit cooler equation. Id. This aspect
of the unit cooler test method is consistent with the current method
specified in appendix C to subpart R of 10 CFR part 431.
For outdoor refrigeration systems, DOE proposed to deviate from the
AHRI 1250-2020 calculations for off-cycle energy use in the April 2022
NOPR. 87 FR 23920, 23955. DOE notes that the AHRI 1250-2020 equations
for average refrigeration system total power input for bin temperature
Tj, (e.g., Equation 13), do not appear to use off-cycle
power values for the unit cooler and/or the condensing unit that vary
with Tj. In fact, there are no equations providing the off-
cycle power for either component as a function of Tj in
section 7 of AHRI 1250-2020, such as there are for net capacity and on-
cycle power input (e.g., Equations 14 through 17). Since the off-cycle
power may vary as a function of outdoor temperature as discussed
previously, DOE proposed in the April 2022 NOPR to adopt instructions
for calculating off-cycle power as a function of outdoor temperature
based on the measurements made at the three outdoor test condition
temperatures. 87 FR 23920, 23955-23956.
For condensing unit off-cycle power, DOE proposed in the April 2022
NOPR to require that off-cycle power for Tj less than or
equal to 35 [deg]F would be equal to the power measured for the test
condition C off-cycle power test. 87 FR 23920, 23956. For Tj
higher than 95 [deg]F, DOE proposed that that off-cycle power would be
equal to the power measured for the test condition A off-cycle power
test. Id. Between these two temperatures, DOE proposed that condensing
unit off-cycle power would be determined based on the test condition B
and C measurements when Tj is below 59 [deg]F, and based on
the A and B measurements when it is above 59 [deg]F, similar to
Equations 14 through 17 for on-cycle capacity and power in AHRI 1250-
2020. Id.
For unit cooler off-cycle power, DOE proposed in the April 2022
NOPR that the three unit cooler off-cycle power measurements taken when
testing a matched-pair or single-packaged dedicated system would be
averaged, and that the resulting average, with no dependence on
Tj, would be used in the AWEF2 calculations. Id.
DOE requested comment on its proposals to align the test procedures
for appendix C1 with AHRI 1250-2020, except for the use of off-cycle
power measurements in the AWEF2 calculations for dedicated condensing
units, matched pairs, and single-
[[Page 28813]]
packaged dedicated systems intended for outdoor installation. Id. DOE
also requested comment on its proposals to use three sets of unit
cooler and outdoor dedicated condensing unit off-cycle measurements in
the AWEF calculations. Id.
In response, KeepRite stated that the AWEF2 calculations could be
non-representative depending on what temperature the crankcase heater
turns on and recommended an option for constant crankcase heater power
below the 35 [deg]F test bins. (KeepRite, No. 36 at p. 3) DOE notes
that the proposed AWEF2 calculations are incorporated from AHRI 1250-
2020. DOE notes that industry agreed to these calculations during the
development of AHRI 1250-2020; therefore, DOE will not consider
alternative calculations for representing off-cycle dedicated
condensing unit power at this time.
RSG recommended that DOE further define off-cycle unit cooler fan
speed as either 50 percent of full speed or the factory low speed
setting (if the low-speed setting is less than 50 percent and not
adjustable by the end user). (RSG, No. 41 at p. 5) DOE notes that
section 4.2 of Appendix C to AHRI 1250-2020 states that for variable-
speed unit cooler fan controls, the greater of 50 percent fan speed or
the manufacturer's default fan speed shall be used for measuring off-
cycle fan energy. Since this is the test practice agreed on by
industry, DOE is not allowing fan speeds of less than 50 percent for
off-cycle unit cooler testing in this final rule.
Lennox stated that the test procedure requires three measurements
at different ambient conditions for matched-pair and single-packaged
dedicated systems but does not explicitly state what to do for split-
system unit coolers. (Lennox, No. 35, at p. 5) Additionally, Lennox
stated that a single test condition may not be sufficient for split-
system unit coolers. Id. DOE clarifies that for matched-pair and
single-packaged dedicated systems located outdoors, there are three
ambient conditions at which the dedicated condensing system is tested,
therefore there are three corresponding off-cycle unit cooler power
measurements. These off-cycle test conditions are specified in Tables 5
and 9 of AHRI 1250-2020 for fixed-capacity matched pairs. AWEF2 is
calculated as the average of these three measurements since these
measurements should not vary with ambient temperature. For split-system
unit coolers tested alone, there is no component exposed to outdoor
ambient conditions, therefore there is only one condition at which the
unit cooler is tested and one corresponding off-cycle power
measurement. These conditions are listed in Tables 16 and 17 of AHRI
1250-2020. As there is only one ambient condition at which the unit
cooler is tested, DOE believes that the single off-cycle measurement is
sufficient for split-system unit coolers.
In this final rule, DOE is adopting the procedures as proposed in
the April 2022 NOPR into appendix C1.
2. Single-Packaged Dedicated Systems
a. AHRI 1250-2020 Methods for Testing
As discussed in the April 2022 NOPR, the Direct Expansion (``DX'')
dual instrumentation method is impractical for testing single-packaged
dedicated systems. 87 FR 23920, 23958. AHRI 1250-2020 expanded methods
of test for single-packaged dedicated systems to include air enthalpy,
calorimetry, and compressor calibration. Specifically, AHRI 1250-2020
incorporates the following test procedures by reference:
(1) Air enthalpy method: ASHRAE 37-2009, ``Methods of Testing for
Rating Electrically Driven Unitary Air-Conditioning and Heat-Pump
Equipment,'' and ANSI/ASHRAE 41.6-2014, ``Standard Method for Humidity
Measurement'';
(2) Calorimeter methods: ASHRAE 16-2016, ``Method of Testing for
Rating Room Air Conditioners, Packaged Terminal Air Conditioners, and
Packaged Terminal Heat Pumps for Cooling and Heating Capacity''; and
(3) Compressor calibration methods: ASHRAE 37-2009, ``Methods of
Testing for Rating Electrically Driven Unitary Air-Conditioning and
Heat-Pump Equipment,'' and ANSI/ASHRAE 23.1- 2010, ``Methods of Testing
for Rating the Performance of Positive Displacement Refrigerant
Compressors and Condensing Units that Operate at Subcritical
Temperatures of the Refrigerant.''
AHRI 1250-2020 requires two simultaneous measurements of system
capacity (i.e., a primary and a secondary method) for single-packaged
dedicated systems, and section C9.2.1 of AHRI 1250-2020 requires that
the measurements agree within 6 percent. Table C4 in AHRI 1250-2020
specifies which test methods (calorimeter, air enthalpy, compressor
calibration) qualify as primary and/or secondary methods. However, as
summarized in Table III.6, DOE is adopting the method of test and the
test hierarchy table in AHRI 1250-2020 with one modification--the
addition of a single-packaged refrigerant enthalpy method. DOE is
adopting this change to support testing of multi-circuit single-
packaged dedicated systems, which is discussed in detail in section
III.G.2.f of this document.
Table III.6--Single-Packaged System Test Methods and Test Hierarchy
------------------------------------------------------------------------
Method of test Test hierarchy
------------------------------------------------------------------------
Balanced Ambient Indoor Calorimeter........ Primary.
Balanced Ambient Outdoor Calorimeter....... Primary or Secondary.
Indoor Air Enthalpy........................ Primary or Secondary.
Indoor Room Calorimeter.................... Primary or Secondary.
Single-packaged Refrigerant Enthalpy \49\.. Secondary.
Outdoor Room Calorimeter................... Secondary.
Outdoor Air Enthalpy....................... Secondary.
Compressor Calibration..................... Secondary.
------------------------------------------------------------------------
b. Waivers
---------------------------------------------------------------------------
\49\ As described in section III.G.2.f of this document, this
method of test does not apply to CO2 single-packaged
units.
---------------------------------------------------------------------------
As discussed in the April 2022 NOPR, DOE granted a waiver to Store
It Cold for single-packaged dedicated systems on August 9, 2019. 87 FR
23920, 23956. DOE also granted waivers to Air Innovations, CellarPro,
Vinotemp, and Vinotheque for walk-in refrigeration systems used in wine
cellar applications, where some of the basic models included in these
waivers were single-packaged dedicated systems.\50\ The alternate test
methods included in each of these waivers require the
[[Page 28814]]
specified basic models to be tested in accordance with the air enthalpy
methods specified in ASHRAE 37-2009 for testing single-packaged
dedicated systems, which is now referenced by AHRI 1250-2020.
Additionally, DOE granted an interim waiver to RSG for multi-circuit
single-packaged dedicated systems (``the RSG waiver''). 87 FR 43808.
The alternate test method included in that waiver is further discussed
in sections III.G.2.d through III.G.2.f of this document.
---------------------------------------------------------------------------
\50\ Table III.1 lists the manufacturers that have received a
test procedure waiver or interim waiver for walk-in refrigeration
systems designed for wine cellar applications.
---------------------------------------------------------------------------
In appendix C1, DOE is referencing the methods of test for single-
packaged dedicated systems from section C9 of AHRI 1250-2020, with some
modifications. Since appendix C1 will be required on the compliance
date of any amended energy conservation standards, were such standards
to be adopted, the current test procedure waivers for specified single-
packaged basic models will expire on the compliance date of appendix
C1.
c. Suitability of the Single-Packaged Test Methods in AHRI 1250-2020
In the April 2022 NOPR, DOE discussed the suitability of the AHRI
1250-2020 test methods for single-packaged dedicated systems. 87 FR
23920, 23957. Specifically, DOE discussed stakeholder feedback from the
June 2021 RFI that freezing of the calorimetry loop and the need for a
pressure equalizing device on the test chamber are potential issues
with the ASHRAE 16-2016 calorimeter method. DOE has tested multiple
single-packaged dedicated systems at multiple labs and did not observe
freezing of the calorimetry loop. Therefore, DOE has determined that
the ASHRAE 16-2016 calorimetry methods are suitable for testing single-
packaged dedicated systems. Furthermore, DOE concluded that the
equalizer device for calorimeter room testing, which is required in
ASHRAE 16-2016, is not necessary for the testing of single-packaged
dedicated systems. As a result, DOE did not propose to require an
equalizer device for calorimeter room testing in the April 2022 NOPR.
Id. Therefore, in the April 2022 NOPR, DOE proposed to adopt the ASHRAE
16-2016 methods of test as referenced in AHRI 1250-2020 to provide
flexibility to manufacturers.
DOE further discussed in the April 2022 NOPR that its testing on
single-packaged dedicated systems using the room calorimeter and air
enthalpy methods as described in AHRI 1250-2020 appropriately accounted
for the thermal losses that are typical for this equipment. Id. DOE
additionally noted that while there may not be extensive experience
applying these test methods to walk-in refrigeration systems, all the
proposed test methods have been evaluated and are used extensively for
testing other heating, ventilation, and air-conditioning (``HVAC'')
equipment. Id. Therefore, in the April 2022 NOPR, DOE tentatively
determined that these methods are representative of single-packaged
dedicated system energy use and proposed to adopt the single-packaged
dedicated system test procedure in AHRI 1250-2020 with the
modifications outlined in sections III.G.2.d and III.G.2.e of this
document. Id.
In response to the April 2022 NOPR, the CA IOUs commented that they
support DOE including a test method for single-packaged dedicated
systems. (CA IOUs, No. 42 at p. 6) Based on DOE's experience testing
this equipment and the comments received, DOE is adopting the test
procedures for single-packaged dedicated systems in AHRI 1250-2020 as
proposed in the April 2022 NOPR into appendix C1.
d. Single-Packaged Refrigerant Enthalpy Method
In the April 2022 NOPR, DOE proposed to adopt a single-packaged
refrigerant method similar to the alternate test procedure outlined in
RSG's waiver request. 87 FR 23920, 23958. On July 22, 2022, DOE issued
an interim waiver to RSG for testing single-packaged dedicated systems
with multiple refrigeration circuits using a modified refrigerant
enthalpy method. 87 FR 43808.
As previously discussed, AHRI 1250-2020 includes four potential
primary and six potential secondary test methods for testing single-
packaged dedicated systems (see Table C4 in AHRI 1250-2020). The
refrigerant enthalpy method is not included in these lists. The
procedure that DOE proposed to adopt in the April 2022 NOPR uses the
refrigerant-side measurements of the DX calibrated box method in
section C8 of AHRI 1250-2020 while simultaneously using one of the
``primary'' methods listed in Table C4 in AHRI 1250-2020 for single-
packaged methods of test as an air-side measurement. The details of the
primary test methods were discussed in the April 2022 NOPR. 87 FR
23920, 23958.
In the April 2022 NOPR, DOE requested comment on its proposed
procedure for testing single-packaged dedicated systems. AHRI
recommended allowing DX dual instrumentation testing, since requiring
air-side enthalpy testing would impose considerable test burden on test
labs that do not have air-side measurement capacity. (AHRI, No. 30 at
p. 7) Lennox stated that it can support the proposed refrigerant
enthalpy approach as a secondary approach but recommended that the DX
dual instrumentation method be maintained as an option. (Lennox, No. 35
at p. 5) Lennox also commented that requiring the air enthalpy test
method would impose significant test burden. Id. In response to the
recommendation by Lennox to maintain the DX dual instrumentation
method, DOE's testing, in addition to the information received in the
waivers for testing of single-packaged dedicated systems, indicates
that the DX dual instrumentation method is inappropriate for single-
packaged units because the internal volume of the added liquid line and
mass flow meters adds substantially to the required refrigerant charge,
and the entire assembly adds substantial pressure drop.\51\ However,
DOE notes that the DX dual instrumentation method continues to be an
accurate test method for dedicated condensing units tested alone.
Additionally, in response to Lennox's comment regarding the burden
associated with the air enthalpy method, DOE has determined that the
representativeness achieved through this method outweighs the
additional burden.
---------------------------------------------------------------------------
\51\ See Store It Cold Decision and Order, 84 FR 39286, 39287
(Aug. 9, 2019).
---------------------------------------------------------------------------
AHRI and Lennox commented that piercing a refrigeration system to
use the refrigerant enthalpy as a secondary check may not duplicate the
primary result. (AHRI, No. 30 at p. 7; Lennox, No. 35 at p. 5) HTPG
disagreed with the proposal to use the refrigerant enthalpy test for
single-packaged dedicated units, as they are critically charged and
piercing their lines could affect measured capacity. (HTPG, No. 32 at
p. 6) The proposed procedure requires a primary test to be completed
before the system is pierced. The capacity measured from the primary
test would be compared to the capacity measured from the secondary test
to ensure that the capacity is not affected from piercing the
refrigeration system. Based on its testing, DOE has determined that a
secondary test that does not materially alter the system operation
would duplicate, and serve as a check for, the primary test. DOE also
notes that there are secondary test options provided in Table C4 of
AHRI 1250-2020 that do not require piercing of the refrigerant lines.
Lennox also stated that the refrigerant enthalpy test should be
allowed to penetrate the system for the primary test since the
secondary test would require the system to be penetrated. (Lennox, No.
35 at p. 5) DOE interprets this comment to be a request to allow the DX
[[Page 28815]]
dual instrumentation test, or other refrigerant enthalpy tests, as a
primary test for single-packaged dedicated systems. As discussed
previously, DOE has concluded that the DX dual instrumentation test is
not representative for single-packaged dedicated systems because it
does not account for thermal losses. DOE reiterates that the purpose of
the primary test, conducted prior to penetration of the refrigerant
system, is to compare the primary and secondary results to ensure that
the system is not affected from penetrating the liquid lines.
AHRI-Wine stated that they do not support the proposed refrigerant
enthalpy test procedure because they do not see an advantage unless the
method is used in parallel with others. (AHRI-Wine, No. 30 at p. 3) DOE
notes that the single-packaged refrigerant enthalpy test procedure
would be used only as a secondary test when paired with one of the
primary options provided in Table C4 of AHRI 1250-2020.
RSG agreed with DOE's proposed test procedure. (RSG, No. 41 at p.
2) DOE is adopting the single-packaged refrigerant enthalpy test method
as a secondary test as proposed in the April 2022 NOPR into appendix
C1.
e. Calibrated Box Method for Single-Packaged Dedicated Systems
In the RSG waiver DOE allowed RSG to use a modified version of the
calibrated box method. 87 FR 43808, 43813-43814. As discussed in the
notification of interim waiver, the modified calibrated box method
involves mounting the system on the calibrated box, like its
installation on a walk-in for field use and exchanging air with the box
interior to cool it. 87 FR 43808, 43812. The exterior of the calibrated
box would be conditioned such that the air conditions entering the
single-packaged dedicated system condenser match the specified targets.
The warm condensing unit portion of the single-packaged dedicated
system and its condenser discharge air may in some cases add to the
thermal load imposed on the calibrated box. The interim waiver
therefore provided additional optional test methods to quantify this
additional thermal load on the calibrated box, and to adjust for it in
the determination of system capacity. Determining the additional
thermal load requires temperature sensors mounted on the box exterior
surface for box calibration and box load determination, rather than
measuring air temperature just outside the box (the approach described
for the calibrated box method in section C8 of AHRI 1250-2020). Since
the modified calibrated box method accounts for the thermal losses
associated with single-packaged dedicated systems and is very similar
to the indoor room calorimeter method, DOE tentatively determined in
the RSG waiver that it would be appropriate for the calibrated box
method to be a primary test method (i.e., the capacity determined from
this method would be used for rating purposes) 87 FR 43808, 43812. DOE
proposed to adopt the method described in the RSG waiver in the April
2022 NOPR. Id. A full discussion of the test procedures proposed by RSG
are discussed in the interim waiver notification. Id.
As mentioned previously, DOE received no stakeholder comments on
the RSG waiver. Therefore, DOE is adopting the test provisions outlined
in the RSG waiver in addition to the test provisions for single-
packaged dedicated systems proposed in the April 2022 NOPR.
f. Multi-Circuit Single-Packaged Dedicated Systems
As discussed in the April 2022 NOPR, neither the current DOE test
procedure nor AHRI 1250-2020 provides a method for testing single-
packaged dedicated systems with multiple refrigeration circuits. As
previously discussed, DOE granted RSG an interim waiver for testing
multi-circuit single-packaged dedicated systems. 87 FR 43808. This test
procedure is based on the single-packaged refrigerant enthalpy method
discussed in section III.G.2.d of this document. The procedure is
duplicated for each refrigeration circuit contained in the unit such
that each circuit returns mass flow, enthalpy in, and enthalpy out
values. The resultant mass flow and enthalpy values are used to
calculate the gross refrigeration capacity for each circuit. Each
circuit's gross capacity is then summed to determine the total capacity
of the system.
In the April 2022 NOPR, DOE tentatively determined that the
alternate approach would provide a reasonable method for determining
the capacity of multi-circuit single-packaged dedicated systems. 87 FR
23920, 23958. However, DOE had also determined the approach may not
adequately capture the heat loss associated with single-packaged
dedicated systems; therefore, DOE proposed to adopt the test procedures
in section C8 of AHRI 1250-2020 for testing single-packaged dedicated
systems, with the additional requirement that the primary test would be
an indoor air refrigeration capacity test where the allowable
refrigeration capacity heat balance is 6 percent. Id.
In response to the April 2022 NOPR, HTPG commented that it agreed
with DOE's proposal for testing multi-circuit single-packaged dedicated
systems. (HTPG, No. 32 at p. 6) DOE is adopting the test procedure as
proposed in the April 2022 NOPR into appendix C1.
g. CO2 Single-Packaged Dedicated Systems
As discussed in the April 2022 NOPR, the current DOE test procedure
for single-packaged dedicated systems does not provide representative
values for single-packaged dedicated systems that use CO2 as
a refrigerant. 87 FR 23920, 23959. However, the single-packaged
dedicated system test methods in AHRI 1250-2020 use air enthalpy
measurements and do not require any refrigerant mass flow measurements.
In the April 2022 NOPR, DOE proposed that single-packaged dedicated
systems that use CO2 as a refrigerant be tested using the
test methods for single-packaged dedicated systems outlined in AHRI
1250-2020. Id.
In response, HTPG stated that it agreed with DOE's proposal for the
air enthalpy test procedure for CO2 single-packaged
dedicated systems. (HTPG, No. 32 at p. 6) DOE is adopting the test as
proposed in the April 2022 NOPR into appendix C1.
3. Detachable Single-Packaged Dedicated Systems
As discussed in section III.A.2.g, DOE is aware of refrigeration
systems that are installed with the evaporator unit exchanging air
through the wall or ceiling of the walk-in, but with the condensing
unit installed remotely and connected to the evaporator with
refrigerant lines. DOE has defined this equipment as a ``detachable
single-packaged dedicated system.'' Neither appendix C nor AHRI 1250-
2020 contain provisions for testing detachable single-packaged
dedicated systems. DOE is aware that, currently, detachable single-
packaged dedicated systems may be tested either with the condensing
unit and unit cooler housings separated or mounted adjacent to each
other, the latter of which is the more common arrangement for single-
packaged dedicated systems. Testing in the latter arrangement would
account for the heat loss of the evaporator installation, and any
additional heat loss from the condensing unit being mounted to the
evaporator unit; therefore, in the April 2022 NOPR, DOE proposed as
part of the new appendix C1 and 10 CFR 429.53(a)(2)(i)(C) that
detachable single-packaged dedicated systems would be tested using the
test procedure for
[[Page 28816]]
single-packaged dedicated systems. 87 FR 23920, 23959.
HTPG and Lennox agreed with the proposal. (HTPG, No. 32 at p. 6;
Lennox, No. 35 at p. 5) AHRI, on behalf of wine cellar manufacturers
stated that the proposal is sufficient. (AHRI-Wine, No. 30 at p. 4) RSG
agreed with the proposal if the calibrated box method is included in
allowable test methods. (RSG, No. 41 at p. 2) As discussed in section
III.G.2.e, DOE is adopting the test provisions outlined in the interim
waiver granted to RSG in July 2022. These include a calibrated box test
procedure for single-packaged dedicated systems.
AHRI stated that the current test procedure is sufficient. (AHRI,
No. 30 at p. 8) DOE interprets this comment as AHRI stating that the DX
dual instrumentation method is sufficient for detachable single-
packaged dedicated units. As discussed in section III.G.2.d, DOE's
testing, in addition to information received in waivers for testing of
single-packaged dedicated systems, indicates that the DX dual
instrumentation method is inappropriate for single-packaged units.
Since detachable single-packaged dedicated systems have thermal
losses similar to those for single-packaged dedicated systems, DOE is
adopting the test procedure for detachable single-packaged dedicated
systems as proposed in the April 2022 NOPR (87 FR 23920, 23959) into
appendix C1.
AHRI-Wine also requested clarification for whether wine cellar
manufacturers must test all configurations or the most common if
multiple configurations apply to a single system. (AHRI-Wine, No. 30 at
p. 2) The definition of ``detachable single-packaged dedicated system''
that DOE is adopting in this final rule states that it is a system that
can be configured as either a split system or as a single-packaged
dedicated system. Based on the procedure DOE is adopting, such a system
would be tested as a single-packaged dedicated system.
4. Attached Split Systems
As discussed in section III.A.2.f, DOE is aware of refrigeration
systems that are sold as matched systems and permanently attached to
each other with beams. In this final rule, DOE is defining these
systems as ``attached split systems.'' DOE has confirmed through
testing that these systems still experience some heat leakage when
compared to traditionally installed systems that have the dedicated
condensing unit and the unit cooler in separate housings. However, this
heat leakage has not been studied extensively and DOE is aware that it
may be difficult to calculate.
DOE proposed in the April 2022 NOPR testing attached split systems
as a matched pair using refrigerant enthalpy methods. 87 FR 23920,
23959. HTPG agreed with the proposal. (HTPG, No. 32 at p. 7) In this
final rule, DOE is adopting the test procedure as proposed in the April
2022 NOPR into appendix C1 and 10 CFR 429.53(a)(2)(i)(D).
5. Systems for High-Temperature Freezer Applications
As discussed in the April 2022 NOPR, DOE recognizes that testing
high-temperature freezer refrigeration systems at a consistent test
condition is important to ensure test procedure consistency and to
provide comparable performance values in the market. 87 FR 23920,
23961. DOE acknowledges that testing high-temperature freezer
refrigeration systems at a temperature less than 35 [deg]F would be
more representative of their actual energy use; however, it is not
clear if the potential additional test burden justifies including an
additional test condition for walk-in cooler refrigeration systems.
Therefore, in the April 2022 NOPR, DOE determined that medium-
temperature dedicated condensing units used in high-temperature freezer
applications would continue to be tested according to appendix C. Id.
In response to the April 2022 NOPR, HTPG stated that it agreed with
DOE continuing to test high-temperature freezers in accordance with
appendix C. (HTPG, No. 32 at p. 7) The Efficiency Advocates encouraged
DOE to establish a standardized rating temperature for high-temperature
freezers that is below 35 [deg]F, since it is more characteristic of
the temperature that these products operate between. (Efficiency
Advocates, No. 37 at p. 3) As discussed in the April 2022 NOPR, DOE
acknowledges that testing high-temperature freezer refrigeration
systems at a temperature less than 35 [deg]F would be more
representative of their actual energy use; however, doing so would
require an additional test condition. At this time, DOE does not think
the relatively small gain in representativeness that this additional
test condition would provide justifies the additional test burden for
evaluating the performance of walk-in cooler refrigeration systems.
Therefore, DOE is maintaining its determination to keep testing systems
for high-temperature freezer applications as medium-temperature
systems.
6. Systems for High-Temperature Applications
As discussed previously in section III.A.2.c, DOE is aware of wine
cellar (high-temperature) refrigeration systems that fall within the
definition of ``walk-in'' but operate at a temperature range of 45
[deg]F to 65 [deg]F and, therefore, are incapable of being tested in a
manner that would yield a representative average use cycle under the
current version of the walk-in test procedure. DOE has granted waivers
or interim waivers to the manufacturers listed in Table I.1 for an
alternate test procedure for specific basic models of single-packaged
dedicated systems, matched pair, and unit cooler-only high-temperature
refrigeration systems.
In the April 2022 NOPR, DOE proposed to include provisions for
testing and rating high-temperature matched-pair systems that specify
an air entering dry-bulb temperature of 55 [deg]F. 87 FR 23920, 23961.
DOE also proposed to test high-temperature refrigeration systems that
are single-packaged dedicated systems using one of the following
methods, as specified in Table C4 of AHRI 1250-2020: indoor air
enthalpy, outdoor air enthalpy, compressor calibration, indoor room
calorimeter, outdoor room calorimeter, balanced ambient indoor
calorimeter, or balanced ambient outdoor calorimeter. Id.
In response to the April 2022 NOPR, the Efficiency Advocates
commented that they support adding unique test procedures for high-
temperature walk-ins. (Efficiency Advocates, No. 37 at p. 2)
The alternate test approach in the waivers requires that testing of
ducted units be conducted at 50 percent of the maximum external static
pressure (``ESP''), subject to a tolerance of -0.00/+0.05 in. wc.\52\
Consistent with the waivers that DOE has granted for high-temperature
refrigeration systems, in the April 2022 NOPR DOE proposed that testing
for ducted systems be conducted with ducts fitted and at 50 percent of
the unit's maximum ESP, subject to a tolerance of -0.00/+0.05 in. wc.
Id. DOE proposed to include this provision for all ducted units (i.e.,
any ducted low-temperature, medium-temperature, or high-temperature
refrigeration system). Id. DOE also proposed clarifying that if testing
using either the indoor or outdoor air enthalpy method, which includes
a measurement of the air volume rate, the airflow measurement apparatus
fan would be
[[Page 28817]]
adjusted to set the ESP--otherwise, the ESP could be set by
symmetrically restricting the outlet of the test duct. Id. If the ESP
is not provided, DOE proposed that it would be set such that the air
volume rate for the test is equal to two-thirds of the value that is
measured for zero ESP operation. Id.
---------------------------------------------------------------------------
\52\ Inches of water column (``in. wc'') is a unit of pressure
conventionally used for measurement of pressure differentials.
---------------------------------------------------------------------------
AHRI-Wine stated that wine cellar manufacturers agree with the
proposed ESP requirements for ducted units; however, they commented
that the proposed procedure for when ESP is not provided represents an
unrealistic reduction in airflow. (AHRI-Wine, No. 30 at p. 4) AHRI-Wine
provided no data or alternative recommendation for a procedure when ESP
is not provided. DOE has determined that the two-thirds air volume rate
is an appropriate value to use when no maximum ESP is provided. DOE
notes that manufacturers can provide maximum ESP to avoid testing using
the two-thirds air volume rate.
AHRI-Wine also commented that wine cellar manufacturers seek
clarification about whether the air surrounding the ducted evaporator
or ducted condenser must be at the required 90 [deg]F indoor
temperature. (AHRI-Wine, No. 30 at p. 3) Furthermore, wine cellar
manufacturers recommended that all wine cellar units, regardless of
specified condenser location, be tested only at 90 [deg]F to clarify
the test procedure and reduce test burden. Id. DOE incorporates by
reference section 7.3.3.3 of ASHRAE 37-2009, which includes provisions
for testing ducted units and accounting for duct losses; therefore, DOE
has determined that the ambient temperature surrounding ducts should
not affect the test results. Consistent with appendix C and the wine
cellar test procedure waivers, DOE is requiring in appendix C1 that
dedicated condensing units located outdoors to be tested at three
temperatures--35 [deg]F, 59 [deg]F, and 95 [deg]F--while dedicated
condensing units located indoors must be tested at 90 [deg]F.
7. Variable-, Two-, and Multiple-Capacity Systems
a. Dedicated Condensing Units
In the April 2022 NOPR, DOE proposed test procedures for variable-,
two-, and multiple-capacity condensing units. The proposals addressed
numerous aspects of how such systems would be tested, including (a)
test conditions (saturated suction temperature and suction temperature)
for part-load operation, (b) compressor operating levels for part-load
testing, (c) default unit cooler fan wattage to use in AWEF2
calculations as a function of compressor operating level, and (d)
calculation of AWEF2 using multiple levels of compressor operation. 87
FR 23920, 23962-23967.
(1) Need for Test Procedures for Variable-, Two- and Multiple-Capacity
Condensing Units
In response to the DOE's proposal, some comments addressed the need
for test procedures for multi-/variable-capacity condensing units and
the potential utility and cost-effectiveness of such systems.
Specifically, AHRI and KeepRite commented that the market for such
systems is very small, and that the small market size is not driven by
lack of test method. AHRI and KeepRite further stated that variable-
capacity system purchases are driven by temperature operating tolerance
requirements rather than energy savings and suggested that energy cost
savings would not offset upfront purchase and installation costs.
(AHRI, No. 30 at p. 8; KeepRite, No. 36 at p. 3) National Refrigeration
commented that there is no need for multi-/variable-capacity test
procedures at this time, indicating also that there is limited to no
evidence that variable-capacity units are more efficient. (National
Refrigeration, No. 39 at p. 2) In response, DOE notes that the DOE test
procedures already include test methods for variable-, two-, and multi-
capacity matched-pair refrigeration systems through incorporation by
reference of AHRI 1250-2009. With the proposal and this final rule, DOE
is extending this test method to dedicated condensing units tested
alone, which was included in the ASRAC Term Sheet. (Docket EERE-2015-
BT-STD-0016, No. 56 at p. 3, recommendation #6)
Despite questions about the need for test procedures for variable-,
two-, and multi-capacity condensing units, AHRI and KeepRite did
indicate that the proposal was reasonable. (AHRI, No. 30 at p. 8;
KeepRite, No. 36 at p. 4) Other commenters' overall comments were
generally supportive regarding DOE's proposed test methods. (RSG, No.
41 at p. 2; CA IOUs, No. 42 at p. 1; Efficiency Advocates, No. 37 at p.
2)
(2) Unit Cooler Fan
DOE requested comment on its assumptions regarding the unit cooler
with which a two-, multi-, or variable-capacity condensing unit rated
alone would be paired in the field, including whether the unit cooler
fan(s) would have a full speed and a half-speed, the compressor
operating level at which the unit cooler fan(s) would switch to half-
speed, and the half-speed wattage of the fan(s). 87 FR 23920, 23966.
AHRI and KeepRite commented that a calculation method should be
allowed for unit cooler fan power rather than just high or low speed,
indicating that some variable compressor systems would reduce capacity
only to 75 percent of full capacity and would not realize a gain from
unit cooler fan power. (AHRI, No. 30 at pp. 8-9; KeepRite, No. 36 at p.
4) DOE understands this comment to mean that there would be limited
efficiency gain for a variable-speed compressor whose lowest capacity
is no lower than 75 percent of full capacity, and that it would be
important to consider optimization of unit cooler fan speed. National
Refrigeration commented that requiring a variable-speed or two-speed
unit cooler fan would be ideal, but the effectiveness is unknown and
more research is necessary to determine how to handle it. (National
Refrigeration, No. 24 at p. 2) Lennox commented that unit coolers with
which two-, multi-, and variable-capacity dedicated condensing units
are paired may use technology in addition to two-speed fans, such as
electronic expansion valves (``EEVs''), dampers, or other electronic
control valves. (Lennox, No. 35 at p. 6)
In response, DOE notes that if a manufacturer decides to optimize
unit cooler fan operation or other design details for a given
condensing unit's compressor technology, the manufacturer has the
option of certifying the two components together as a matched pair--
this is already an established part of the test procedure for outdoor
matched pairs, and DOE is extending the approach to indoor matched
pairs in this document (see section III.G.7.b of this document).
DOE notes that the test method under consideration applies to
dedicated condensing units tested alone--these units would be paired
with a unit cooler in the field, so it is not clear what technology the
paired unit cooler might have. For this reason, DOE developed the
proposal for two-, multi-, and variable-capacity dedicated condensing
units based on the assumption of limited unit cooler technology
options. DOE's analysis suggests that use of part-load compressor
operation has limited to no efficiency benefit when the unit cooler
fan(s) run at full speed. However, DOE is aware that many unit coolers
are now sold with two-speed fan motors to meet the current energy
conservation standards. (No. 44 at p. 2) Hence, DOE determined that it
is reasonable to assume that field matches of dedicated condensing
units tested alone would involve, at minimum, a unit cooler with
[[Page 28818]]
a two-speed fan. DOE does not have information that would suggest that
unit coolers sold alone would typically have fully variable-speed fans,
EEVs, dampers, or other electronic control valves. For this reason, DOE
does not believe it is appropriate to establish a test procedure for
dedicated condensing units tested alone, assuming such technology is
available in a field-paired unit cooler, therefore DOE has not modified
the test procedure to reflect the potential benefits of these
technologies.
Some commenters indicated that, although unit cooler fans may have
two speeds, the low speed may be triggered by the off-cycle rather than
by on-cycle compressor operation. (AHRI, No. 30 at p. 8; Lennox, No. 35
at p. 6; National Refrigeration, No. 39 at p. 2) As mentioned, DOE
concluded that running unit cooler fans at full speed during part-load
operation significantly limits the part-load efficiency benefits. Given
the prevalence of unit coolers being sold with two-speed fans, DOE
concludes it is reasonable to assume that such unit coolers would be
controlled to allow two-speed fan operation during part-load when
field-matched with a two-, multi-, or variable-speed dedicated
condensing unit.
DOE requested comment on its assumptions regarding the compressor
operating level at which the unit cooler fan(s) would switch from full-
to half-speed operation. 87 FR 23920, 23966. AHRI commented that no
change was needed, and National Refrigeration was supportive. (AHRI,
No. 30 at p. 9; National Refrigeration, No. 39 at p. 2) No commenters
suggested that switching to half-speed operation should occur at
different compressor operating levels. Hence, DOE is finalizing the
test procedure using the same 65 percent compressor operating level
below which the unit cooler fan(s) would be assumed to operate at half-
speed.
DOE requested comment on the proposal that the unit cooler fan
half-speed power input would be 20 percent of full speed power. 87 FR
23920, 23966. Several commenters agreed with this approach. (AHRI, No.
30 at p. 9; National Refrigeration, No. 39 at p. 2; Lennox, No. 35 at
p. 6) DOE is finalizing its test procedure using the 20 percent half-
speed power level.
(3) Part-Load Test Conditions
DOE requested comment on the compressor part-load operating levels
for multi- and variable-speed dedicated condensing units tested alone.
87 FR 23920, 23966. Lennox, AHRI, and National Refrigeration supported
the proposed levels. (Lennox, No. 35 at p. 6; AHRI, No. 30 at p. 9,
National Refrigeration, No. 39 at p. 2) DOE is finalizing the test
procedure using the compressor part-load operating levels proposed in
the April 2022 NOPR.
Regarding the test conditions proposed for part-load operation of
variable-, two-, or multiple-capacity dedicated condensing units,
several commenters suggested that the differing refrigerant conditions
specified for the different tests were excessively complex and should
be simplified. (AHRI, No. 30 at p. 9; Lennox, No. 35 at p. 6; National
Refrigeration, No. 39 at p. 2) In response to DOE's specific question
about whether a tabular method for specifying test operating conditions
or a correlation-based approach should be used, Lennox expressed a
clear preference for a tabular approach, indicating that the
correlation approach may provide more flexibility but would require
more data collection and should be evaluated for accuracy. (Lennox, No.
35 at p. 6) Other commenters did not express a clear position. For
example, AHRI commented that, while the correlation approach may
provide more flexibility, it should be used only if it is shown to be
more accurate. (AHRI, No. 30 at p. 9)
DOE's intent in allowing different suction conditions for testing
was to make the test method more representative of actual operation, in
which unit cooler effectiveness would improve at part load, suction
line pressure drop would decrease, and suction line heat transfer would
be more effective. These factors would combine generally to raise the
dedicated condensing unit inlet pressure (specified as saturated
suction temperature in the test procedures) and also the suction
temperature. 87 FR 23920, 23964.
Some commenters indicated that these variations would make little
impact in test results. (Lennox, No. 35 at p. 6) DOE analyzed the
proposed test conditions to evaluate this statement for outdoor
refrigeration systems using R-448A, calculating the impact on
compressor EER \53\ and isolating the impact of the change in suction
conditions as compared with the full-load test conditions,\54\ and not
including the potential benefits of improved condenser effectiveness at
part load nor the potential change in the compressor's compression
efficiency for different operating conditions. The analysis showed
that, for medium-temperature dedicated condensing units, the impact of
the modified suction conditions ranged from -2.3 percent (a decrease)
to 7.7 percent, with an average of 2.8 percent. For low-temperature
condensing units, the range of impact was from -3.0 percent to 2.4
percent, with an average of -0.2 percent. This analysis shows that an
increase in saturated suction temperature improves compressor EER,
while an increase in suction temperature reduces compressor EER. These
factors appear to balance out on average for low-temperature systems,
while for medium-temperature systems, the improvement associated with
the saturated suction temperature increase makes more impact than the
suction temperature increase. In addition, the results do not change
significantly when considering other refrigerants commonly used in WICF
refrigeration systems, e.g. R-404A and R-407A. For indoor medium-
temperature refrigeration systems, the overall impact of the changes is
less pronounced, since testing only with the A conditions using 90
[deg]F condenser ambient air increases the impact of the refrigerant
temperature rise in the suction line. For outdoor medium-temperature
systems, DOE found that raising the saturated suction temperature 1
[deg]F for all part-load conditions to 24 [deg]F and leaving the
suction temperature unchanged at 41 [deg]F provided the best overall
agreement in compressor EER compared with the average EER impact of the
different proposed test conditions. Consequently, DOE is finalizing the
specification of suction conditions for testing variable-, two-, and
multiple-capacity dedicated condensing units with the following
simplifications: For low-temperature and indoor medium-temperature
dedicated condensing units, the required part-load test conditions will
match the full-capacity conditions. For outdoor medium-temperature
dedicated condensing units, the part-load saturated suction temperature
will be raised 1 [deg]F to 24 [deg]F, without changing the 41 [deg]F
suction temperature requirement. DOE believes this approach provides
the best balance between test procedure simplicity and providing some
adjustment of operating conditions to represent the impacts of changes
in unit cooler and suction line response to part load.
---------------------------------------------------------------------------
\53\ Evaporator capacity divided by compressor input power.
\54\ 23 [deg]F saturated suction temperature and 41 [deg]F
temperature for medium-temperature systems; -22 [deg]F saturated
suction temperature and 5 [deg]F temperature for low-temperature
systems.
---------------------------------------------------------------------------
b. Indoor Matched Pair and Single-Packaged Units
DOE proposed in the April 2022 NOPR to establish test procedures
for indoor matched-pair and single-
[[Page 28819]]
packaged dedicated systems. 87 FR 23920, 23966.
National Refrigeration stated that indoor matched pairs have less
potential for part-load energy savings than their outdoor counterparts
due to their constant condensing inlet temperature. (National
Refrigeration, No. 39 at p. 2) KeepRite stated that the proposed
approach for indoor matched pairs is acceptable, even though these
units have even less potential for part-load energy savings due to the
constant condenser inlet temperature. (KeepRite, No. 36 at p. 4) DOE
understands that these commenters were referring to constant condenser
air inlet temperature, which would result in constant condensing
temperature. Lennox supported the proposal to establish test methods
for indoor two-, multi-, or variable-capacity condensing units tested
alone. (Lennox, No. 35 at p.6) No commenters indicated that DOE should
not establish test methods for such systems. Hence, DOE is adopting the
test method as proposed.
c. Revision to EER Calculation for Outdoor Variable-Capacity and
Multiple-Capacity Refrigeration Systems
In the April 2022 NOPR, DOE proposed to revise the EER calculations
for outdoor variable-capacity and multiple-capacity refrigeration
systems to use a piecewise linear calculation approach rather than the
parabolic equation provided in AHRI 1250-2020. 87 FR 23920, 23966. DOE
did not receive any comments specifically addressing this proposal and
is finalizing the test procedure with the revisions as proposed.
d. Digital Compressors
In the April 2022 NOPR, DOE discussed specific proposals associated
with digital compressors. To clarify the test procedure for digital
compressors, DOE proposed to define ``digital compressor'' as a
compressor that uses mechanical means for disengaging active
compression on a cyclic basis to provide a reduced average refrigerant
flow rate in response to an input signal. 87 FR 23920, 23967. DOE
received no comments specifically addressing the digital compressor
definition and will adopt the definition as proposed.
As discussed in the April 2022 NOPR, DOE had conducted testing and
found that the refrigerant enthalpy method for measuring capacity is
accurate if the liquid subcooling at the mass flow meter is
sufficiently low, as required in section C3.4.5 of AHRI 1250-2020. Id.
DOE proposed that testing refrigeration equipment with digital
compressors operating at part load may use the refrigerant enthalpy
method as a secondary test method, with the following provisions and
adjustments: (1) pressure and temperature measurement would be at a
frequency of once per second or faster, (2) the operating tolerances
for pressure and temperature at both the inlet and outlet connections
and for mass flow would not apply, and (3) enthalpies determined for
the capacity calculation would be based on test-period-average pressure
and temperature values. Id.
DOE also proposed that the selection of the primary test method for
measuring capacity would depend on the refrigeration system
configuration. Id. For single-packaged dedicated systems, the test
methods adopted as primary methods for any single-packaged dedicated
system would be used, as discussed in section III.G.2 of this document.
Matched pairs would use the same primary methods used for single-
packaged dedicated systems. For dedicated condensing units, the primary
methods include outdoor air enthalpy method, balanced ambient outdoor
calorimeter, and outdoor room calorimeter measurements.
Lennox supported the proposals for the part-load test procedure for
refrigeration systems with digital compressors. (AHRI, No. 30 at p. 10;
Lennox, No. 35 at p. 7) KeepRite and AHRI commented that the
refrigerant enthalpy method may be unreliable for digital compressors
because they cannot achieve steady state. However, these commenters did
not provide evidence that the method would be unreliable. (KeepRite,
No. 36 at p. 4; AHRI, No. 30 at p. 9) KeepRite and AHRI also indicated
that 1-second intervals for power measurements would not be sufficient
for energy measurement of digital compressors and that integrating
power meters must be used. Id. However, AHRI also stated that the part-
load test procedure for refrigeration systems with digital compressors
is sufficient as written. (AHRI, No. 30 at p. 9) AHRI provided further
specific comments, including (a) wider refrigerant pressure and mass
flow tolerances look acceptable, (b) the 1-second or higher data
acquisition rate looks acceptable, but that industry-wide ability to
sample at this rate should be assessed, (c) that when using the
refrigerant enthalpy method with single-package systems with digital
compressors, the existing primary methods look acceptable, and (d)-(e)
when using the refrigerant enthalpy method to test matched pairs or
condensing units alone with digital compressors, the existing dual
instrumentation method should be an acceptable primary method for
measuring capacity. (AHRI, No. 30 at pp. 9, 10)
DOE notes that the industry standard, AHRI 1250-2020, already has a
requirement that energy measurements be made using an integrating watt-
hour meter and that power measurements be made with a sampling rate of
no less than 1 per second (see section C10.2.1.4 of AHRI 1250-2020)--
thus, through incorporation by reference of AHRI 1250-2020, the
proposal is already consistent with the KeepRite and AHRI comments
regarding use of an integrating power meter for energy measurements and
already adopts 1-second intervals for data acquisition. It is DOE's
understanding that test laboratories already use data acquisition
systems with this level of capability. As indicated, the commenters did
not provide data countering the cited DOE evidence that the refrigerant
enthalpy method measurement is accurate. Given the limited data
available on this issue, DOE is not deviating from its proposal that
the refrigerant enthalpy method only be used as a secondary capacity
measurement, i.e., the test procedure as finalized in this document
does not allow it to be used as a primary capacity measurement as
recommended by AHRI for matched pairs and dedicated condensing units
tested alone. Therefore, DOE is adopting the proposals for digital
compressor systems as stated in the April 2022 NOPR.
8. Defrost
The current test procedure references section C11 of AHRI 1250-2009
to measure defrost. In section C11 of AHRI 1250-2009, the moisture to
provide a frost load is introduced through the infiltration of air at a
75.2 [deg]F dry-bulb temperature and a 64.4 [deg]F wet-bulb temperature
into the walk-in freezer at a constant airflow rate that depends on the
refrigeration capacity of the tested freezer unit (Equations C11 and
C12 in section C11.1.1 of AHRI 1250-2009). A key issue with this
approach is the difficulty in ensuring repeatable frost development on
the unit under test, despite specifying the infiltration air dry-bulb
and wet-bulb temperatures. For example, in addition to frost
accumulating on the evaporator of the unit under test, frost may also
accumulate on the evaporator of other cooling equipment used to
condition the room, which could subsequently affect the rate of frost
accumulation on the unit under test by affecting the amount of moisture
remaining in the air.
Since there are recognized limitations to the defrost test
procedure in section C11 of AHRI 1250-2009, AHRI 1250-
[[Page 28820]]
2020 does not include a frosted-coil test but does include provisions
for a dry-coil defrost test.\55\ Industry is currently evaluating how
to create and validate consistent evaporator coil frost loads;
therefore, in the April 2022 NOPR, DOE proposed to maintain the current
calculation-based approach for estimating defrost energy consumption.
Specifically, DOE proposed to incorporate by reference section C10 of
AHRI 1250-2020 for unit coolers with either electric or hot gas
defrost, except for section C10.2.1.1, ``Test Room Conditioning
Equipment.'' At this time, DOE does not have sufficient data to fully
evaluate how the test room condition requirements in section C10.2.1.1
of AHRI 1250-2020 would impact the representativeness of the test
procedure during the dry-coil defrost test relative to potential
additional test burden.
---------------------------------------------------------------------------
\55\ AHRI 1250-2020 includes an adaptive defrost challenge test
in appendix E (Appendix E) and a hot gas defrost challenge test in
appendix F (Appendix F) that require a frosted-coil. The tests in
both of these appendices are labeled as ``informative,'' and were
designed to evaluate adaptive defrost or hot gas defrost
functionality, respectively, rather than to quantify defrost energy
use.
---------------------------------------------------------------------------
In response to the April 2022 NOPR, HTPG commented that it agreed
with the proposal to incorporate the entirety of Section C10 of AHRI
1250-2020, except for section C10.2.1.1. (HTPG, No. 32 at p. 7) HTPG
also agreed that all systems would use the same default calculated
values to rate defrost power. Id.
The CA IOUs stated that they support DOE adopting a test method for
measuring defrost energy use in a future test procedure and that if DOE
adopts a test method, DOE should reconsider the frequency at which
defrost is used. (CA IOUs, No. 42 at p. 2) DOE will continue to
evaluate defrost energy use and may address defrost energy in a future
test procedure rulemaking. In this final rule, DOE is adopting the
procedures as proposed in the April 2022 NOPR in appendix C1.
a. Adaptive Defrost
Adaptive defrost refers to a factory-installed defrost control
system that reduces defrost frequency by initiating defrosts or
adjusting the number of defrosts per day in response to operating
conditions, rather than initiating defrost strictly based on compressor
run time or clock time. 10 CFR 431.303. In the April 2022 NOPR, DOE
proposed to maintain its current requirements for adaptive defrost. 87
FR 23920, 23969. DOE received no comments on its proposal. In this
final rule, DOE is maintaining the current regulatory approach to
include the optional representation strategy for adaptive defrost.
b. Hot Gas Defrost
In the April 2022 NOPR, DOE proposed that manufacturers may account
for a unit's potential improved performance with hot gas defrost in its
market representations. 87 FR 23920, 23970. DOE proposed that this hot
gas defrost ``credit'' may be used in marketing materials for all
refrigeration system varieties sold with hot gas defrost (i.e., matched
pairs, standalone unit coolers, and standalone condensing units). Id.
However, due to the variation of hot gas defrost applications
across the refrigeration systems market, and a lack of consensus on the
definition of ``hot gas defrost'' systems (see discussion in section
III.A.2.i of this document), DOE is not adopting a hot gas defrost
``credit'' for representation purposes.
9. Refrigerant Glide
Refrigerant glide refers to the increase in temperature at a fixed
pressure as liquid refrigerant vaporizes during its conversion from
saturated liquid (at its bubble point) to saturated vapor (at its dew
point). R-404A--a common walk-in refrigerant--has very little glide,
while R-407A--another common walk-in refrigerant--can exhibit glide of
up to 8 [deg]F.
The current DOE test procedure specifies unit cooler test
conditions based on the dew point at the evaporator exit. For zero-
glide refrigerants, the average evaporator temperature will typically
be equivalent to the specified dew point. However, for high-glide
refrigerants, the average evaporator temperature will be significantly
lower than the dew point since the refrigerant temperature will
increase (up to the dew point) as it travels through the evaporator. As
a result, two identical unit coolers, one charged with R-404A and one
with R-407A, will be tested at different evaporator-to-air temperature
differences (``TD''), but with the same evaporator airflow. Measured
capacity is directly correlated with the product of TD and airflow;
therefore, the high-glide R-407A unit cooler would achieve a higher
rated capacity than the R-404A unit cooler. However, this capacity
difference is an artifact of the test procedure, which requires that
unit coolers and dedicated condensing units be tested alone. In the
field, a unit cooler will be paired with a dedicated condensing unit,
and R-407A unit coolers will not actually provide additional capacity
when compared to their R-404A counterparts. For these reasons, the
current test procedure is not refrigerant-neutral.
In the April 2022 NOPR, DOE discussed how the current test
procedure is not refrigerant-neutral in terms of high-glide and zero-
glide refrigerants because it uses dewpoint throughout the test
procedure. 87 FR 23920, 23970. DOE also discussed the modified midpoint
approach, which is more refrigerant-neutral. The modified midpoint
approach attempts to standardize the average evaporator temperature,
rather than standardizing the evaporator dew point. In doing so,
identical unit coolers using zero- and high-glide refrigerants would
exhibit identical TDs, thus alleviating concerns of overstated
capacity.
While a modified midpoint approach may be more refrigerant-neutral,
DOE notes that the AHRI 1250-2020, which DOE is referencing in appendix
C1, uses a dewpoint rather than a modified midpoint approach. DOE does
not have enough information at this time to justify the use of a
modified midpoint approach. As a result, in the April 2022 NOPR, DOE
proposed to continue to use dew point throughout the test procedure.
Id.
In response to the April 2022 NOPR, HTPG commented that it
disagrees with the midpoint approach and suggested maintaining the dew
point approach. (HTPG, No. 32 at p. 7) DOE is adopting the proposal
from the April 2022 NOPR and continuing to specify refrigerant
conditions using dew point.
10. Refrigerant Temperature and Pressure Instrumentation Locations
As discussed in the April 2022 NOPR, the specified superheat in
AHRI 1250-2020 differs from the current DOE test procedure for
dedicated condensing unit efficiency calculations, but there is no
effective difference in where the required pressure and temperature
measurements should be taken on the equipment under test. 87 FR 23920,
23971. However, Figure C2 in AHRI 1250-2020 suggests that the use of a
suction line mass flow meter for these measurements is not allowed. In
the April 2022 NOPR, DOE proposed to clarify that a second mass flow
meter in the suction line would be allowed with the adoption of AHRI
1250-2020. Id. Specifically, DOE clarified that the second mass flow
measurement for the DX dual instrumentation method may be in the
suction line upstream of the inlet to the condensing unit, as shown in
Figure C1 of AHRI 1250-2009. AHRI, HTPG, Lennox, Hussmann, and RSG
agreed with the proposal. (AHRI, No. 30 at p. 10; HTPG, No. 32 at p. 7;
Lennox,
[[Page 28821]]
No. 35 at p. 7; Hussmann, No. 38 at p. 10; RSG, No. 41 at p. 2)
AHRI also commented that DOE should only reference AHRI 1250-2020,
not both AHRI 1250-2020 and AHRI 1250-2009, for the location of flow
meters. (AHRI, No. 30 at p. 10) DOE is clarifying that only AHRI 1250-
2020 will be referenced in appendix C1, and that AHRI 1250-2009 is
mentioned in this discussion only to explain the intention of the
proposal. Therefore, DOE is adopting the test procedure as proposed in
the April 2022 NOPR.
11. Updates to Default Values for Unit Cooler Parameters
As discussed in section III.B.3.c, Sections 7.9.1 and 7.9.2 of AHRI
1250-2020 add new equations to calculate on-cycle evaporator fan power
when testing a dedicated condensing unit alone. These equations are
different from those in the current test procedure in appendix C, which
calculates on-cycle evaporator fan power based on the cooling capacity
of the condensing unit. The equations in AHRI 1250-2020 are based on
more test data and analysis than those currently in appendix C. In the
April 2022 NOPR, DOE proposed to adopt the calculations for on-cycle
evaporator fan power for dedicated condensing units tested alone as
prescribed in AHRI 1250-2020. 87 FR 23920, 23971-23972.
AHRI, HTPG, Lennox, and RSG agreed with the proposed on-cycle
evaporator fan power calculations. (AHRI, No. 30 at p. 10; HTPG, No. 32
at p. 7; Lennox, No. 35 at p. 7; RSG, No. 41 at p. 2) DOE is adopting
the test procedure as proposed in the April 2020 NOPR.
12. Calculations and Rounding
In the April 2022 NOPR, DOE proposed new rounding requirements for
AWEF and capacity to ensure greater test procedure consistency. 87 FR
23920, 23972. DOE clarifies here that the rounding requirements
proposed in the April 2022 NOPR should have been for AWEF2 and not
AWEF, which means that any rounding requirements would become effective
when appendix C1 becomes effective.
DOE recognizes that the way values are rounded can affect the
resulting capacity and AWEF2 values. To ensure consistency in
calculating capacity and AWEF2 values, DOE proposed in the April 2022
NOPR that raw measured data be used in all capacity and AWEF2
calculations. Id. DOE's current standards specify a minimum AWEF2 value
in Btu/(W-h) to the hundredths place. DOE proposed rounding AWEF2
values to the nearest 0.05 Btu/(W-h). Id. To round capacity, DOE
proposed to round to the nearest multiple as specified in Table III.7.
The proposed capacity bins and multiples are consistent with other HVAC
test procedures.\56\
---------------------------------------------------------------------------
\56\ A version of Table III.14 can be found in AHRI Standard 390
I-P (2021), ``Performance Rating of Single-Package Vertical Air-
conditioners and Heat Pumps.''
Table III.7--Refrigeration Capacity Rating Ranges and Their Rounding
Multiples
------------------------------------------------------------------------
Multiples, Btu/
Refrigeration capacity ratings, 1,000 Btu/h h
------------------------------------------------------------------------
<20..................................................... 100
>=20 and <38............................................ 200
>=38 and <65............................................ 500
>=65.................................................... 1,000
------------------------------------------------------------------------
AHRI, HTPG, KeepRite, Lennox, and National Refrigeration
recommended that AWEF2 values be rounded to the nearest 0.01 Btu/(W-h),
as current standards are taken to that precision. (AHRI, No. 30 at pp.
10-11; HTPG, No. 32 at p. 8; KeepRite, No. 36 at p. 4; Lennox, No. 35
at p. 7; National Refrigeration, No. 39 at p. 2) DOE agrees that
rounding to the nearest 0.05 Btu/(W-h) as proposed may cause confusion.
Therefore, DOE is requiring that AWEF2 values be rounded to the nearest
0.01 Btu/(W-h).
AHRI, AHRI-Wine, and RSG agreed with the proposed capacity ranges
and respective rounding requirements. (AHRI, No. 30 at p. 10; AHRI-
Wine, No. 30 at p. 4; RSG, No. 41 at p. 2) DOE is adopting the capacity
rounding requirements as proposed in the April 2022 NOPR and summarized
in Table III.7.
H. Alternative Efficiency Determination Methods for Refrigeration
Systems
Pursuant to the requirements of 10 CFR 429.70, DOE may permit use
of an AEDM in lieu of testing equipment for which testing burden may be
considerable and for which that equipment's energy efficiency
performance may be well predicted by such alternative methods. Although
specific requirements vary by product or equipment, use of an AEDM
entails development of a mathematical model that estimates energy
efficiency or energy consumption characteristics of the basic model, as
would be measured by the applicable DOE test procedure. The AEDM must
be based on engineering or statistical analysis, computer simulation or
modeling, or other analytic evaluation of performance data. A
manufacturer must perform validation of an AEDM by demonstrating that
the performance, as predicted by the AEDM, agrees with the performance
as measured by actual testing in accordance with the applicable DOE
test procedure. The validation procedure and requirements, including
the statistical tolerance, number of basic models, and number of units
tested vary by product or equipment.
Once developed, an AEDM may be used to rate and certify the
performance of untested basic models in lieu of physical testing.
However, use of an AEDM for any basic model is always at the option of
the manufacturer. One potential advantage of AEDM use is that it may
free a manufacturer from the burden of physical testing. One potential
risk is that the AEDM may not perfectly predict performance, and the
manufacturer could be found responsible for having an invalid rating
for the equipment in question or for having distributed a noncompliant
basic model. The manufacturer, by using an AEDM, bears the
responsibility and risk of the validity of the ratings. For walk-ins,
DOE currently permits the use of AEDMs for refrigeration systems only.
10 CFR 429.70(f).
In a final rule published on May 13, 2014, DOE established that
AEDMs can be used by walk-in refrigeration manufacturers, once certain
qualifications are met, to certify compliance and report ratings. 79 FR
27388, 27389. That rule established a uniform, systematic, and fair
approach to the use of these types of modeling techniques that has
enabled DOE to ensure that products in the marketplace are correctly
rated--irrespective of whether they are subject to actual physical
testing or are rated using modeling--without unnecessarily burdening
regulated entities. Id. A minimum of two distinct models must be tested
to validate an AEDM for each validation class.
DOE is adopting new test procedures for single-packaged dedicated
systems, high-temperature refrigeration systems, and CO2
unit coolers. Application design temperature of the refrigerated
environment has a significant impact on equipment performance;
therefore, in the April 2022 NOPR, DOE proposed to incorporate new AEDM
validation classes for all high-temperature refrigeration systems
(single-packaged dedicated systems and matched-pair systems). 87 FR
23920, 23973. Additionally, single-packaged units are expected to
perform differently than dedicated condensing units under the test
procedure which incorporates thermal losses. Therefore, in the April
[[Page 28822]]
2022 NOPR, DOE proposed to create new validation classes for low-
temperature, medium-temperature, and high-temperature single-packaged
dedicated systems. Id. To ensure that walk-in validation classes are
consistent with DOE's current walk-in terminology, DOE proposed to
rename the ``unit cooler connected to a multiplex condensing unit''
validation classes to ``unit cooler'' at either medium- or low-
temperature; however, the AEDM requirements for these classes remain
the same. Id. Finally, DOE proposed to remove the medium-/low-
temperature indoor/outdoor condensing unit validation classes, as these
are redundant with the medium-/low-temperature indoor/outdoor dedicated
condensing unit validation classes. Id.
Implementation of appendix C1 will require that all AEDMs for
single-packaged dedicated systems are amended to be consistent with the
test procedure proposed in appendix C1.
The AEDM validation classes for walk-in refrigeration equipment DOE
proposed in the April 2022 NOPR are as follows:
Dedicated Condensing Unit, Medium-Temperature, Indoor System
Dedicated Condensing Unit, Medium-Temperature, Outdoor System
Dedicated Condensing Unit, Low-Temperature, Indoor System
Dedicated Condensing Unit, Low-Temperature, Outdoor System
Single-packaged Dedicated System, High-Temperature, Indoor
System
Single-packaged Dedicated System, High-Temperature, Outdoor
System
Single-packaged Dedicated System, Medium-Temperature, Indoor
System
Single-packaged Dedicated System, Medium-Temperature, Outdoor
System
Single-packaged Dedicated System, Low-Temperature, Indoor
System
Single-packaged Dedicated System, Low-Temperature, Outdoor
System
Matched Pair, High-Temperature, Indoor Condensing Unit
Matched Pair, High-Temperature, Outdoor Condensing Unit
Matched Pair, Medium-Temperature, Indoor Condensing Unit
Matched Pair, Medium-Temperature, Outdoor Condensing Unit
Matched Pair, Low-Temperature, Indoor Condensing Unit
Matched Pair, Low-Temperature, Outdoor Condensing Unit
Unit Cooler, High-Temperature
Unit Cooler, Medium-Temperature
Unit Cooler, Low-Temperature
Additionally, DOE proposed in the April 2022 NOPR to maintain the
provision that outdoor models within a given validation class may be
used to determine represented values for the corresponding indoor
class, and additional validation testing is not required. 87 FR 23920,
23973. For example, two medium-temperature outdoor dedicated condensing
units may be used to validate an AEDM for both the ``Dedicated
Condensing Unit, Medium-Temperature, Outdoor System'' class and the
``Dedicated Condensing Units, Medium-Temperature, Indoor System''
class. If indoor models that fall within a given validation class are
tested and used to validate an indoor AEDM, however, that test data may
not be used to validate the equivalent outdoor validation class.
In the April 2022 NOPR, DOE proposed no additional modifications to
the walk-in specific AEDM provisions within 10 CFR 429.70(f). Id. In
the April 2022 NOPR, DOE requested comment on its proposal to modify
and extend its AEDM validation classes. Id.
AHRI, Lennox, National Refrigeration, and RSG agreed with the
proposed AEDM validation classes. (AHRI, No. 30 at p. 11; Lennox, No.
35 at p. 8; National Refrigeration, No. 39 at p. 2; RSG, No. 41 at p.
3) HTPG agreed with DOE's proposals to (1) add single-packaged
dedicated system validation classes, (2) to rename ``unit cooler
connected to a multiplex condensing unit'' validation classes to ``unit
cooler,'' and (3) to remove medium-/low-temperature indoor/outdoor
condensing unit validation classes to eliminate redundancy. (HTPG, No.
32 at p. 8) AHRI-Wine agreed with the proposed validation classes.
(AHRI-Wine, No. 30 at p. 4)
AHRI-Wine requested clarification on whether there are AEDM
validation classes for high-temperature dedicated condensing units. Id.
DOE is clarifying that there are no AEDM validation classes for high-
temperature dedicated condensing units. As discussed in section
III.F.7, DOE has found that the wine cellar industry seems to use
general-purpose dedicated condensing units, which must meet the medium-
temperature dedicated condensing unit energy conservation standard and
should be certified as such. These general-purpose dedicated condensing
units would fall into the ``Dedicated Condensing Unit, Medium-
Temperature Outdoor System'' or ``Dedicated Condensing Unit, Medium-
Temperature Indoor System'' AEDM validation class.
DOE is adopting the AEDM validation classes for refrigeration
systems as proposed in the April 2022 NOPR.
I. Sampling Plan for Enforcement Testing
As discussed in the April 2022 NOPR, DOE uses appendix B to subpart
C of 10 CFR part 429 to assess compliance for walk-in refrigeration
systems, which is specifically intended for use for covered equipment
and certain low-volume covered products. 87 FR 23920, 23973. DOE does
not specifically reference which appendix in subpart C of 10 CFR part
429 it uses for determination of compliance for walk-in doors or walk-
in panels. In an Enforcement NOPR published on August 31, 2020
(``August 2020 Enforcement NOPR''), DOE proposed to add walk-in cooler
and freezer doors and walk-in panels to the list of equipment subject
to the low-volume enforcement sampling procedures in appendix B to
subpart C of 10 CFR part 429. 85 FR 53691, 53696. DOE noted that this
equipment is not currently included within DOE's list because when the
current regulations were drafted, walk-in doors and walk-in panels did
not have applicable performance standards, only design standards, and
therefore sampling provisions were not necessary at the time. In the
April 2022 NOPR, DOE proposed to include walk-in doors and walk-in
panels in the list of covered equipment and certain low-volume products
at 10 CFR 429.110(e)(2). 87 FR 23920, 23973.
AHRI, Hussmann, Bally, and RSG all requested clarification on the
definition of ``low-volume.'' (AHRI, No. 30 at p. 11; Hussmann, No. 34
at p. 4; Bally, No. 40 at p. 5; RSG, No. 41 at p. 3)
DOE does not define a numerical threshold for ``low-volume'' or
``high-volume'' products and equipment, and for some products and
equipment the Department may consider volume on a case-by-case basis.
DOE created the ``low-volume'' designation to separate built-to-order
equipment from pre-manufactured, off the shelf products, providing
built-to-order equipment a longer time period to ship a basic model. 76
FR 12421, 12435. In the context of enforcement, 10 CFR 429.110(e)(1)
states that DOE will use a sample size of not more than 21 units and
follow the sampling plans in appendix A to subpart C of 10 CFR part 429
to determine compliance with the applicable DOE standards for high-
volume equipment, while DOE will use a sample size of not more than 4
units and follow the sampling plans in appendix B to subpart C of 10
CFR part 429 to determine compliance with the applicable DOE standards
for low-volume equipment. As specified in 10 CFR 429.110(b), units
selected for
[[Page 28823]]
enforcement evaluation are provided by the manufacturer. DOE notes that
walk-in refrigeration systems are currently included in the list of
covered equipment and certain low-volume products at 10 CFR
429.110(e)(2). Including walk-in door and panels ensures all walk-in
components are similarly evaluated. DOE is including walk-in doors and
panels in the list of covered equipment and certain low-volume covered
products at 10 CFR 429.110(e)(2) and thus will use the sampling plan in
appendix B to subpart C of 10 CFR part 429.
DOE is adopting the enforcement sampling plan as proposed in the
April 2022 NOPR.
Bally also asked for clarification regarding how the low-volume
sampling procedures work when coupled with new section 5.4.3 of
appendix B to subpart R of 10 CFR part 431. (Bally, No. 40 at p. 5)
Bally asked whether appendix B to subpart C of 10 CFR part 429 is a
restatement of 10 CFR 429.53(a)(3)(ii)(B)(2). Id. DOE notes that the
sampling plan provisions in appendix B to subpart C of 10 CFR part 429
are strictly for the Department's evaluation of compliance when
conducting enforcement testing. The provisions at 10 CFR
429.53(a)(3)(ii)(B)(2) are the requirements that manufacturers are
required to follow when determining the represented value certified to
DOE. DOE did not propose to make changes to the certification language
in the April 2022 NOPR. The provisions in the new section 5.4.3 of
appendix B to subpart R of 10 CFR part 431 are intended to allow
manufacturers to use K-factor test results from a set of test samples
to determine R-value of envelope components with varying foam
thicknesses as long as the foam throughout the panel is of the same
final chemical form and the test was completed at the same test
conditions as other envelope components. In other words, if a
manufacturer offers 4-inch and 5-inch cooler panels, the manufacturer
may use the K-factor results of a single series of tests to determine
the R-value for both the 4-inch and 5-inch cooler panels.
J. Organizational Changes
In the April 2020 NOPR, DOE proposed a number of non-substantive
organizational changes. 87 FR 23920, 23977. As discussed previously,
DOE proposed to reorganize appendices A and B so that they are easier
for stakeholders to follow as a step-by-step test procedure.
Additionally, DOE proposed to remove the specifications at 10 CFR
429.53(a)(2)(i) regarding specific test procedure provisions and
instead include these provisions in the uniform test method section at
10 CFR 431.304. The intent of this proposed change was to move
provisions of the applicable test procedure to the appropriate place in
subpart R, rather than keeping them under the provisions for
determining represented values for certification. However, DOE proposed
to keep the additional detail regarding the represented values of
various configurations of refrigeration systems (e.g., outdoor and
indoor dedicated condensing units, matched refrigeration systems, etc.)
at 10 CFR 429.53(a)(2)(i).
DOE received no comment on these proposals regarding organizational
changes and therefore is adopting them as proposed in the April 2022
NOPR.
K. Test Procedure Costs and Impact
EPCA requires that test procedures proposed by DOE be reasonably
designed to produce test results which reflect energy efficiency and
energy use of a type of industrial equipment during a representative
average use cycle and not be unduly burdensome to conduct. (42 U.S.C.
6314(a)(2)) The following sections discuss DOE's evaluation of the
estimated costs and savings associated with the amendments in this
final rule.
1. Doors
In this document, DOE is adopting the following amendments to the
test procedures in appendix A for walk-in cooler and freezer doors:
Referencing NFRC 102-2020 for the determination of U-
factor;
Including AEDM provisions for manufacturers to alternately
determine the total energy consumption of display and non-display
doors;
Providing additional detail for determining the area used
to convert U-factor into conduction load, As, to
differentiate it from the area used to determine compliance with the
standards, Add or And;
Specifying a PTO value of 97 percent for door motors.
The first and third amendments, referencing NFRC 102-2020 and
additional detail on the area used to convert U-factor into a
conduction load, improve the consistency, reproducibility, and
representativeness of test procedure results. The second amendment,
including AEDM provisions, intends to provide manufacturers with the
flexibility to use an alternative method to testing that provides good
agreement for their doors. The fourth amendment, including a PTO value
of 97 percent, intends to provide a more representative and consistent
means for comparison of walk-in door performance for doors with motors.
DOE has determined that these proposed amendments would improve the
representativeness, accuracy, and reproducibility of the test results,
and would not be unduly burdensome for door manufacturers to conduct.
DOE has also determined that these proposed amendments would not
increase testing costs per basic model relative to the current DOE test
procedure in appendix A, which DOE estimates to be $10,000 for third-
party labs to determine energy consumption of a walk-in door, including
physical U-factor testing per NFRC 102-2020.\57\ Finally, DOE has
determined that manufacturers would not be required to redesign any of
the covered equipment or change how the equipment is manufactured
solely as a result of these amendments.
---------------------------------------------------------------------------
\57\ DOE estimates the cost of one test to determine energy
consumption of a walk-in door, including one physical U-factor test
per NFRC 102-2020, to be $5,000. Per the sampling requirements
specified at 10 CFR 429.53(a)(3)(ii) and 429.11(b), manufacturers
are required to test at least two units to determine the rating for
a basic model, except where only one unit of the basic model is
produced.
---------------------------------------------------------------------------
The cost impact to manufacturers as a result of the reference to
NFRC 102-2020 and inclusion of AEDM provisions is dependent on the
agreement between tested and simulated values as specified in section
4.7.1 of NFRC 100-2010 \58\ and as referenced in the current test
procedure. For manufacturers of doors that have been able to achieve
the specified agreement between U-factors simulated using the method in
NFRC 100-2010 and U-factors tested using NFRC 102-2020, after
physically conducting testing to validate the AEDM, manufacturers would
be able to continue using the simulation method in NFRC 100-2010
provided it meets the basic requirements proposed for an AEDM in 10 CFR
429.53 and 429.70(f).
---------------------------------------------------------------------------
\58\ Section 4.7.1 of NFRC 100-2010 requires that the accepted
difference between the tested U-factor and the simulated U-factor be
(a) 0.03 Btu/(h-ft\2\-[deg]F) for simulated U-factors that are 0.3
Btu/(h-ft\2\-[deg]F) or less, or (b) 10 percent of the simulated U-
factor for simulated U-factors greater than 0.3 Btu/(h-ft\2\-
[deg]F). This agreement must match for the baseline product in a
product line. Per NFRC 100-2010, the baseline product is the
individual product selected for validation; it is not synonymous
with ``basic model'' as defined in 10 CFR 431.302.
---------------------------------------------------------------------------
For manufacturers of doors that have not been able to achieve the
specified agreement between U-factors simulated using the method in
NFRC 100-2010 and U-factors tested using NFRC 102-2020, DOE estimates
that the test burden would decrease. Under the current requirements,
manufacturers may be required to determine U-factor through physical
testing of every basic model. With the new test procedure,
[[Page 28824]]
manufacturers who would have otherwise been required to physically test
every walk-in door basic model could develop an AEDM for rating their
basic models of walk-in doors consistent with the proposed provisions
in 10 CFR 429.53 and 429.70(f). DOE estimates the per-manufacturer cost
to develop and validate an AEDM for a single validation class of walk-
in doors to be $11,100. DOE estimates an additional cost to determine
energy consumption of a walk-in door using an AEDM to be $46 per basic
model.\59\
---------------------------------------------------------------------------
\59\ DOE estimated initial costs to validate an AEDM assuming 24
hours of general time to develop and validate an AEDM based on
existing simulation tools. DOE estimated the cost of an engineering
calibration technician fully burdened wage of $46 per hour plus the
cost of third-party physical testing of two basic models per
proposed validation class. DOE estimated the additional per basic
model cost to determine efficiency using an AEDM assuming 1 hour per
basic model at the cost of an engineering calibration technician
wage of $46 per hour.
---------------------------------------------------------------------------
DOE expects that the additional detail provided for determining the
area used to convert U-factor into conduction load, As,
would either result in reduced energy consumption or have no impact. To
the extent that this change to the test procedure would amend the
energy consumption attributable to a door, such changes would either
not change the calculated energy consumption or result in a lower
energy consumption value as compared to how manufacturers may currently
be rating, given that the current test procedure does not provide
specific details on measurement of Add and And.
As such, DOE expects that manufacturers would be able to rely on data
generated under the current test procedure. While manufacturers must
submit a report annually to certify a basic model's represented values,
basic models do not need to be retested annually. The initial test
results used to generate a certified rating for a basic model remain
valid if the basic model has not been modified from the tested design
in a way that makes it less efficient or more consumptive, which would
require a change to the certified rating. If a manufacturer has
modified a basic model in a way that makes it more efficient or less
consumptive, new testing is only required if the manufacturer wishes to
make claims using the new, more efficient rating.\60\
---------------------------------------------------------------------------
\60\ See guidance issued by DOE at www1.eere.energy.gov/buildings/appliance_standards/pdfs/cert_faq_2012-04-17.pdf.
---------------------------------------------------------------------------
For doors without motors, DOE has concluded that the proposed test
procedure would not change energy consumption ratings, which would not
require rerating solely as result of DOE's adoption of this amendment
to the test procedure. Therefore, DOE has determined all proposed
amendments either decrease or result in no additional testing costs to
manufacturers of walk-in doors.
To the extent that changes to the test procedure would amend the
energy consumption attributable to a door motor, such changes would
either not change the calculated energy consumption or result in a
lower energy consumption value as compared to the currently granted
waivers addressing door motors. As such, DOE expects that manufacturers
would be able to rely on data generated under the current test
procedure and current waivers. While manufacturers must submit a report
annually to certify a basic model's represented values, basic models do
not need to be retested annually. The initial test results used to
generate a certified rating for a basic model remain valid if the basic
model has not been modified from the tested design in a way that makes
it less efficient or more consumptive, which would require a change to
the certified rating. If a manufacturer has modified a basic model in a
way that makes it more efficient or less consumptive, new testing is
only required if the manufacturer wishes to make claims using the new,
more efficient rating.
In the April 2022 NOPR, DOE requested comment on its understanding
of the impact of the test procedure proposals for appendix A. 87 FR
23920, 23979.
AHRI stated that it is unable to determine or comment on impact
until it understands the AEDM for doors. (AHRI, No. 30 at p. 11) DOE
has provided additional detail regarding AEDMs in section III.C.1 of
this document and estimates that the test burden would decrease for the
industry as a whole.
Bally commented that the $11,000 estimated cost for U-factor
testing doesn't consider the cost of materials. (Bally, No. 40 at p. 5)
DOE has determined that the DOE test procedure for walk-in doors is
non-destructive and that units can therefore be recovered after
testing. For this reason, DOE does not include the cost of the unit
under test.
While stakeholders did not specifically recommend including freight
costs in the test cost estimates for walk-in doors, they did recommend
including freight costs in the test cost estimates for walk-in
refrigeration systems (discussed in section III.K.3 of this document).
DOE acknowledges that freight costs are an additional expense
associated with third-party testing. Therefore, to be consistent with
the estimates provided for refrigeration system testing, DOE has
estimated the cost of round-trip freight. DOE estimates that the
shipping cost for a walk-in box from a manufacturing facility to a test
lab can range from $800 to $2,500 depending on the relative locations
of the two facilities, the weight and size of the unit being shipped,
and the discounts associated with shipping multiple units at one time.
Thus, DOE estimates the round-trip freight costs as ranging from $1,600
to $5,000.
2. Panels
In this final rule, DOE is amending the existing test procedure in
appendix B for measuring the R-value of insulation of panels by:
Incorporating by reference the updated version of the
applicable industry test method, ASTM C518-17;
Including provisions specific to measurement of test
specimen and total insulation thickness; and
Providing a method for determining the parallelism and
flatness of the test specimen.
The first amendment incorporates by reference the most up-to-date
version of the industry standards currently referenced in the DOE test
procedure. The second and third amendments include additional
instructions intended to improve consistency and reproducibility of
test procedure results.
DOE has determined that these proposed amendments would improve the
accuracy and reproducibility of the test results and would not be
unduly burdensome for manufacturers to conduct, nor would they be
expected to increase the testing burden.
DOE expects that the proposed test procedure in appendix B for
measuring the R-value of insulation would not increase testing costs
per basic model relative to the current DOE test procedure, which DOE
estimates to be $1,200 for third-party laboratory testing.\61\
Additionally, DOE has determined that the test procedure in appendix B
would not result in manufacturers having to redesign any of the covered
equipment or change how the equipment is manufactured.
---------------------------------------------------------------------------
\61\ DOE estimates the cost of one test to determine R-value to
be $600. Per the sampling requirements specified at 10 CFR
429.53(a)(3)(ii) and 429.11(b), manufacturers are required to test
at least two units to determine the rating for a basic model, except
where only one unit of the basic model is produced.
---------------------------------------------------------------------------
In the April 2022 NOPR, DOE requested comment on its understanding
of the impact of the test procedure proposals for appendix B. 87 FR
23920, 23975.
AHRI agreed with DOE's understanding of the impact of the test
[[Page 28825]]
procedure. (AHRI, No. 30 at p. 12) Bally commented that the increased
measurement and complex calculations involving least squares regression
for parallelism and flatness are overly burdensome and that it
anticipates difficulty finding laboratories capable of doing the
calculations. (Bally, No. 40 at p. 6) In response to Bally's comment,
DOE reiterates that the measurement and calculations for parallelism
and flatness are necessary to improve the accuracy and reproducibility
of the test results. Additionally, what Bally has identified as
increased measurement are generally measurements that are already being
taken by third party laboratories, but which have not been specified in
the DOE test procedure. With respect to the complexity of the
calculations, DOE notes that third party laboratories typically use
templates to run calculations which would be repeated for multiple
tests conducted and that, while a laboratory may need to initially
update the template they use, the calculations would not be overly
complex and burdensome on an ongoing basis for testing. DOE was also
able to find laboratories capable of doing the additional measurements
and calculations. Thus, DOE has determined that the procedure is not
overly burdensome.
Because the test procedure for walk-in panels is destructive and
that units cannot be recovered after testing, DOE is including in its
evaluation the cost of the unit under test. DOE estimates the cost of a
walk-in panel to range from $90 to $300, depending on size and
materials used, and when testing a minimum of two units of a basic
model as required by 10 CFR 429.53(a)(1), a total cost of $180 to $600
per basic model.
DOE acknowledges that freight costs are an additional expense
associated with third-party testing. Therefore, DOE has estimated the
cost of freight to the test facility. DOE estimates that the shipping
cost for one walk-in box from a manufacturing facility to a test
laboratory can range from $800 to $2,500 depending on the relative
locations of the two facilities, the weight and size of the unit being
shipped, and the discounts associated with shipping multiple units at
one time.
3. Refrigeration Systems
DOE is adopting certain changes to appendix C that DOE has
determined will improve the accuracy and reproducibility of the test
results and would not be unduly burdensome for manufacturers to
conduct. DOE has further determined that these changes will not impact
testing cost. Additionally, the amended, appendix C measures AWEF per
AHRI 1250-2009, and therefore does not contain any changes that will
require retesting or rerating. The current testing costs which DOE have
determined will be equivalent to the amended appendix C testing costs
are summarized in this section. DOE's assessment of the impacts of the
amendments of appendix C to include new test procedures for high-
temperature refrigeration systems and CO2 unit coolers are
discussed in more detail in this section.
In response to the April 2022 NOPR, HTPG agreed that proposals to
appendix C will not be unduly burdensome or impact cost. (HTPG, No. 32
at p. 8)
DOE is also adopting certain changes in the new appendix C1 that
will amend the existing test procedure for walk-in coolers and freezers
by:
Expanding the off-cycle refrigeration system power
measurements;
Adding methods of test for single-packaged dedicated
systems; and
Including a method for testing ducted systems.
DOE has determined that these amendments will improve the
representativeness, accuracy, and reproducibility of the test results,
and will not be unduly burdensome for manufacturers to conduct. DOE has
also determined that these amendments will impact testing costs by
equipment type. DOE does not anticipate that the remainder of the
amendments adopted in this final rule would impact test costs or test
burden. DOE estimates third-party costs for testing to the current DOE
test procedure to be:
$10,000 for outdoor low-temperature and medium-temperature
dedicated condensing units tested alone;
$6,500 for indoor low-temperature and medium-temperature
dedicated condensing units tested alone;
$6,500 for low-temperature unit coolers tested alone;
$6,000 for medium-temperature unit coolers tested alone;
$10,000 for single-packaged dedicated systems; and
$10,000 for high-temperature matched pairs.
As discussed previously in section III.G.1 of this document, DOE is
adopting off-cycle test provisions in AHRI 1250-2020 for walk-in cooler
and freezer refrigeration systems. The current test procedure requires
off-cycle power to be measured at a single ambient condition (i.e., 90
[deg]F). The new test procedure requires off-cycle to be measured at
three different ambient conditions (i.e., 95 [deg]F, 59 [deg]F, and 35
[deg]F) for outdoor dedicated condensing units, outdoor matched pair
systems, and outdoor dedicated systems. The matched-pair and single-
packaged dedicated systems include high-temperature refrigeration
systems. When the waivers for these high-temperature refrigeration
systems were granted, only one off-cycle test was required; therefore,
manufacturers with waivers would be required to conduct additional
testing compared to the alternate test procedure currently required.
DOE estimates that measuring off-cycle power at these additional
ambient conditions may increase third-party lab test cost by $1,000 per
unit to a total cost of $11,000 per unit for outdoor dedicated
condensing units, outdoor matched-pair systems, and outdoor single-
packaged dedicated systems.
Manufacturers are not required to perform laboratory testing on all
basic models. In accordance with 10 CFR 429.53, WICF refrigeration
system manufacturers may elect to use AEDMs. DOE estimates the per-
manufacturer cost to develop and validate an AEDM for outdoor dedicated
condensing units and outdoor matched-pair systems to be $24,600.\62\
DOE estimates an additional cost of approximately $46 per basic model
\63\ for determining energy efficiency of a given basic model using the
validated AEDM.
---------------------------------------------------------------------------
\62\ Outdoor single-packaged systems are also impacted by the
proposed adoption of the AHRI 1250-2020 single-packaged test
procedure for walk-in cooler and freezer refrigeration systems. The
combined potential cost increase for outdoor single-packaged systems
is presented in the next paragraph.
\63\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
As discussed previously in section III.G.2, DOE is adopting the
single-packaged dedicated system test procedure for walk-ins in AHRI
1250-2020. The procedure requires air enthalpy tests to be used as the
primary test method. In the current test procedure, single-packaged
dedicated systems use refrigerant enthalpy as the primary test method.
DOE does not estimate a difference in physical testing costs between
air and refrigerant enthalpy testing of single-packaged units. DOE
estimates the per-unit third-party lab test cost to be $11,000 for
outdoor single-packaged dedicated
[[Page 28826]]
systems and $6,500 for indoor single-packaged dedicated systems.
However, should a manufacturer choose to use an AEDM, it may incur
additional costs regarding the development and validation of new AEDMs
for single-packaged dedicated systems. DOE estimates the per-
manufacturer cost to develop and validate an AEDM to be $24,600 for
outdoor single-packaged units and $15,600 for indoor single-packaged
units. DOE estimates an additional cost of approximately $46 per basic
model \64\ for determining energy efficiency using the validated AEDM.
---------------------------------------------------------------------------
\64\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
As discussed in sections III.F.6 and III.G.6, DOE is adopting test
procedures for CO2 unit coolers and high-temperature
refrigeration systems. DOE estimates that the average third-party lab
per unit test cost would be $11,000 for a high-temperature matched-pair
or single-packaged dedicated system, $6,000 for a high-temperature unit
cooler tested alone, $6,500 for a low-temperature CO2 unit
cooler, and $6,000 for a medium-temperature CO2 unit cooler.
As discussed previously, DOE has granted waivers to certain
manufacturers for both high-temperature refrigeration systems and
CO2 unit coolers. The test procedures being adopted are
consistent with the alternate test procedures included in the granted
waivers. For those manufacturers who have been granted a test procedure
waiver for this equipment, DOE expects that there would be no
additional test burden. However, DOE expects that there would be
additional testing costs for any manufacturers of these products who
have not submitted or been granted a test procedure waiver at the time
this test procedure is finalized. Such companies may incur an
additional per unit test cost of:
$11,000 for a high-temperature matched-pair or single-
packaged system;
$6,000 for a high-temperature unit cooler tested alone;
$6,500 for a low-temperature CO2 unit cooler
tested alone; and
$6,000 for a medium-temperature CO2 unit cooler
tested alone.
In the April 2022 NOPR, DOE requested comment on its understanding
of the impact of the test procedure proposals for refrigeration
systems. 87 FR 23920, 23976.
AHRI commented that a third-party lab test of a low-temperature
unit cooler would be two to three times more expensive than DOE's
$6,500 estimate. (AHRI, No. 30 at p. 12) Lennox stated that, in
general, DOE's amendments increase work content of the test and
therefore increase test costs. (Lennox, No. 35 at p. 8) Lennox also
stated that the costs of their third-party lab tests have been at least
double DOE's estimates. Id. RSG commented that it considers DOE's
estimates to be very low and stated that there are few outside labs
capable of testing to the degree that DOE requires. (RSG, No. 41 at p.
3) AHRI-Wine stated that they believe the estimated testing burden is
reasonable and consistent. (AHRI-Wine, No. 30 at p. 4) DOE notes that
the estimated test costs were based on actual lab quotes, which DOE has
determined are representative of the pricing available to the industry
as a whole. Additionally, DOE is aware of third-party labs that have
the capability to test to the current DOE test procedure.
HTPG disagreed with DOE's test cost estimates for AEDMs and stated
that 40 hours of labor per refrigerant is more accurate and therefore
test costs would be multiplied by the number of refrigerants. (HTPG,
No. 32 at p. 8) HTPG also stated that more validation would be done by
manufacturers than what was estimated to ensure an AEDM applies across
a basic model family. Id.
DOE notes that the estimated AEDM cost is per AEDM and does not
make assumptions about the number of AEDMs needed based on the
refrigerants used by a given manufacturer. DOE used the minimum number
of tests (two) needed to validate an AEDM. While manufacturers may
choose to test more units to validate an AEDM, testing more than two is
not required.
AHRI stated that small original equipment manufacturers (``OEMs'')
represent a significant amount of the market and will be negatively
impacted by added complexity and costs. (AHRI, No. 30 at p. 12) NAFEM
encouraged DOE to consider the limitation of lab capacity and the
financial impacts on small businesses. (NAFEM, No. 33 at p. 2) DOE
specifically discusses the test procedure burden imposed on small
businesses in section IV.B of this document.
AHRI stated that EPA and DOE regulations will impact small
refrigeration OEMs in a relatively immediate time frame. (AHRI, No. 30
at p. 12) NAFEM also commented that DOE should evaluate how various EPA
rulemakings may impact energy efficiency improvements in the WICF
manufacturing process and available products. (NAFEM, No. 33 at p. 2)
DOE acknowledges that while there are other regulations that impact
walk-in equipment, DOE will take cumulative regulatory burden into
account in the ongoing energy conservation standards rulemaking as part
of its manufacturer impact analysis.
AHRI and Lennox commented that the test cost estimates should
include freight cost, unit cost, and cost of a unit to run the test.
(AHRI, No. 30 at p. 12; Lennox, No. 35 at p. 8) DOE acknowledges that
freight costs are an additional expense associated with third-party
testing. DOE has determined that the DOE test procedure is non-
destructive and that units can therefore be recovered after testing.
For this reason, DOE has estimated the cost of round-trip freight, but
does not include the cost of the unit under test. Additionally, DOE
notes that the test procedure does not specifically require use of the
unit matched to the unit under test (i.e., a dedicated condensing unit
matched to a unit cooler under test, or a unit cooler matched to a
dedicated condensing unit under test).
DOE estimates that the shipping cost for one walk-in unit from a
manufacturing facility to a test laboratory can range from $250 to
$1,000 depending on the relative locations of the two facilities, the
weight and size of the unit being shipped, and the discounts associated
with shipping multiple units at one time. Thus, DOE estimates the
round-trip freight costs as ranging from $500 to $2,000.
DOE additionally notes that it has used third-party laboratory test
costs for its estimate of test costs. DOE understands that most walk-in
refrigeration system manufacturers have their own test chambers. In
these cases, DOE expects that its estimate for test and freight costs
is conservative.
L. Effective and Compliance Dates
The effective date for the adopted test procedure amendment will be
30 days after publication of this final rule in the Federal Register.
EPCA prescribes that all representations of energy efficiency and
energy use, including those made on marketing materials and product
labels, must be made in accordance with an amended test procedure,
beginning 180 days after publication of the final rule in the Federal
Register. (42 U.S.C. 6314(d)(1)) EPCA provides an allowance for
individual manufacturers to petition DOE for an extension of the 180-
day period if the manufacturer may experience undue hardship in meeting
[[Page 28827]]
the deadline. (42 U.S.C. 6314(d)(2)) To receive such an extension,
petitions must be filed with DOE no later than 60 days before the end
of the 180-day period and must detail how the manufacturer will
experience undue hardship. Id. To the extent the modified test
procedure adopted in this final rule is required only for the
evaluation and issuance of updated efficiency standards, compliance
with the amended test procedure does not require use of such modified
test procedure provisions until the compliance date of updated
standards.
Upon the compliance date of test procedure provisions in this final
rule, any waivers that had been previously issued and are in effect
that pertain to issues addressed by such provisions are terminated. 10
CFR 431.404(h)(3). Recipients of any such waivers are required to test
the products subject to the waiver according to the amended test
procedure as of the compliance date of the amended test procedure. The
amendments adopted in this document pertain to issues addressed by
waivers granted to the manufacturers listed in Table III.8.
Table III.8--Manufacturers Granted Waivers and Interim Waivers
----------------------------------------------------------------------------------------------------------------
Proposed test
Manufacturer Subject Case No. Relevant test procedure compliance
procedure date
----------------------------------------------------------------------------------------------------------------
Jamison Door Company............. PTO for Door Motors. 2017-009 Appendix A.......... 10/31/2023.
HH Technologies.................. PTO for Door Motors. 2018-001 Appendix A.......... 10/31/2023.
Senneca Holdings................. PTO for Door Motors. 2020-002 Appendix A.......... 10/31/2023.
Hercules......................... PTO for Door Motors. 2020-013 Appendix A.......... 10/31/2023.
HTPG............................. CO2 Unit Coolers.... 2020-009 Appendix C.......... 10/31/2023.
Hussmann......................... CO2 Unit Coolers.... 2020-010 Appendix C.......... 10/31/2023.
KeepRite......................... CO2 Unit Coolers.... 2020-014 Appendix C.......... 10/31/2023.
RefPlus, Inc..................... CO2 Unit Coolers.... 2021-006 Appendix C.......... 10/31/2023.
RSG.............................. Multi-Circuit Single- 2022-004 Appendix C.......... 10/31/2023.
Package Dedicated
Systems.
LRC Coil......................... Wine Cellar 2020-024 Appendix C \65\..... 10/31/2023.
Refrigeration
Systems.
Store It Cold.................... Single-Packaged 2018-002 Appendix C1......... Compliance date of
Dedicated Systems. updated standards.
CellarPro........................ Wine Cellar 2019-009 Appendix C1......... Compliance date of
Refrigeration updated standards.
Systems.
Air Innovations.................. Wine Cellar 2019-010 Appendix C1......... Compliance date of
Refrigeration updated standards.
Systems.
Vinotheque....................... Wine Cellar 2019-011 Appendix C1......... Compliance date of
Refrigeration updated standards.
Systems.
Vinotemp......................... Wine Cellar 2020-005 Appendix C1......... Compliance date of
Refrigeration updated standards.
Systems.
----------------------------------------------------------------------------------------------------------------
IV. Procedural Issues and Regulatory Review
---------------------------------------------------------------------------
\65\ DOE notes that Table III.15 in the April 2022 NOPR should
have listed appendix C instead of appendix C1 as the relevant test
procedure for the LRC Coil waiver. 87 FR 23920, 23977.
---------------------------------------------------------------------------
A. Review Under Executive Orders 12866 and 13563
Executive Order (``E.O.'') 12866, ``Regulatory Planning and
Review,'' as supplemented and reaffirmed by E.O. 13563, ``Improving
Regulation and Regulatory Review,'' 76 FR 3821 (Jan. 21, 2011),
requires agencies, to the extent permitted by law, to (1) propose or
adopt a regulation only upon a reasoned determination that its benefits
justify its costs (recognizing that some benefits and costs are
difficult to quantify); (2) tailor regulations to impose the least
burden on society, consistent with obtaining regulatory objectives,
taking into account, among other things, and to the extent practicable,
the costs of cumulative regulations; (3) select, in choosing among
alternative regulatory approaches, those approaches that maximize net
benefits (including potential economic, environmental, public health
and safety, and other advantages; distributive impacts; and equity);
(4) to the extent feasible, specify performance objectives, rather than
specifying the behavior or manner of compliance that regulated entities
must adopt; and (5) identify and assess available alternatives to
direct regulation, including providing economic incentives to encourage
the desired behavior, such as user fees or marketable permits, or
providing information upon which choices can be made by the public. DOE
emphasizes as well that E.O. 13563 requires agencies to use the best
available techniques to quantify anticipated present and future
benefits and costs as accurately as possible. In its guidance, the
Office of Information and Regulatory Affairs (``OIRA'') in the Office
of Management and Budget (``OMB'') has emphasized that such techniques
may include identifying changing future compliance costs that might
result from technological innovation or anticipated behavioral changes.
For the reasons stated in the preamble, this final regulatory action is
consistent with these principles.
Section 6(a) of E.O. 12866 also requires agencies to submit
``significant regulatory actions'' to OIRA for review. OIRA has
determined that this final regulatory action does not constitute a
``significant regulatory action'' under section 3(f) of E.O. 12866.
Accordingly, this action was not submitted to OIRA for review under
E.O. 12866.
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires
preparation of a final regulatory flexibility analysis (``FRFA'') for
any final rule where the agency was first required by law to publish a
proposed rule for public comment, unless the agency certifies that the
rule, if promulgated, will not have a significant economic impact on a
substantial number of small entities. As required by Executive Order
13272, ``Proper Consideration of Small Entities in Agency Rulemaking,''
67 FR 53461 (August 16, 2002), DOE published procedures and policies on
February 19, 2003, to ensure that the potential impacts of its rules on
small entities are properly considered during the DOE rulemaking
process. 68 FR 7990. DOE
[[Page 28828]]
has made its procedures and policies available on the Office of the
General Counsel's website: www.energy.gov/gc/office-general-counsel.
DOE reviewed this final rule under the provisions of the Regulatory
Flexibility Act and the procedures and policies published on February
19, 2003.
The Energy Policy and Conservation Act, Public Law 94-163, as
amended (``EPCA''),\66\ authorizes DOE to regulate the energy
efficiency of a number of consumer products and certain industrial
equipment. (42 U.S.C. 6291-6317) Title III, Part C \67\ of EPCA, added
by Public Law 95-619, Title IV, section 441(a), established the Energy
Conservation Program for Certain Industrial Equipment, which sets forth
a variety of provisions designed to improve energy efficiency. This
equipment includes walk-in coolers and walk-in freezers (collectively
``WICFs'' or ``walk-ins''), the subject of this document. (42 U.S.C.
6311(1)(G)) DOE is publishing this final rule in satisfaction of the 7-
year review requirement specified in EPCA. (42 U.S.C. 6314(b)(1))
---------------------------------------------------------------------------
\66\ All references to EPCA in this document refer to the
statute as amended through the Energy Act of 2020, Public Law 116-
260 (Dec. 27, 2020), which reflect the last statutory amendments
that impact Parts A and A-1 of EPCA.
\67\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
DOE has conducted a focused inquiry into small business
manufacturers of the equipment covered by this rulemaking. DOE used the
Small Business Administration's small business size standards to
determine whether any small entities would be subject to the
requirements of the rule. The size standards are listed by North
American Industry Classification System (``NAICS'') code as well as by
industry description and are available at www.sba.gov/document/support-table-size-standards. Manufacturing WICFs is classified under NAICS
333415, ``Air-Conditioning and Warm Air Heating Equipment and
Commercial and Industrial Refrigeration Equipment Manufacturing.'' The
SBA sets a threshold of 1,250 employees or fewer for an entity to be
considered as a small business for this category.\68\ DOE used publicly
available information to identify potential small businesses that
manufacture WICFs covered in this rulemaking. DOE reviewed its
Certification Compliance Database (``CCD'') \69\ and the California
Energy Commission's Modernized Appliance Efficiency Database System
(``MAEDbS'') \70\ to identify manufacturers. DOE also used
subscription-based business information tools (e.g., reports from Dun &
Bradstreet \71\) to determine headcount and revenue of the small
businesses.
---------------------------------------------------------------------------
\68\ The size standards are listed by NAICS code and industry
description and are available at: www.sba.gov/document/support-table-size-standards. (Last accessed Oct. 11, 2022.)
\69\ U.S. Department of Energy Compliance Certification
Database, available at www.regulations.doe.gov/certification-data/#q=Product_Group_s%3A*. (Last accessed March 16, 2022.)
\70\ California Energy Commission's Modernized Appliance
Efficiency Database System, available at
cacertappliances.energy.ca.gov/Pages/Search/AdvancedSearch.aspx.
(Last accessed Nov. 1, 2021.)
\71\ D&B Hoovers reports are available at app.dnbhoovers.com.
(Last accessed Oct. 12, 2022.)
---------------------------------------------------------------------------
Using these data sources, DOE identified 78 original equipment
manufacturers (``OEMs'') of WICFs that could be potentially affected by
this rulemaking. DOE screened out companies that do not meet the
definition of a ``small business'' or are foreign-owned and operated.
Of these 78 OEMs, 57 are small, domestic manufacturers. DOE notes that
some manufacturers may produce more than one of the principal
components of WICFs: doors, panels, and refrigeration systems. Forty-
one of the small, domestic OEMs manufacture doors; 35 of the small,
domestic OEMs manufacture panels; and 18 of the small, domestic OEMs
manufacture refrigeration systems.
In response to the Initial Regulatory Flexibility Analysis
published as part of the April 2022 NOPR, AHRI noted that while they
are unsure of the exact number of small OEMs of WICF panels, doors, and
refrigeration systems, they acknowledge that small OEMs represent a
significant portion of the WICF market. AHRI asserted that small OEMs
would be negatively impacted by what AHRI characterized as the added
complexity and related costs. AHRI also noted that EPA and DOE
regulatory actions that are not yet fully resolved have impact in a
relatively immediate timeframe. (AHRI, No. 30 at p. 12)
DOE agrees with AHRI that small businesses account for the majority
of WICF component OEMs operating in the United States. Regarding AHRI's
concerns about complexity, DOE evaluates test procedures for each type
of covered equipment, including WICFs, to determine whether amended
test procedures would more accurately or fully comply with the
requirements for the test procedures to not be unduly burdensome to
conduct and be reasonably designed to produce test results that reflect
energy efficiency, energy use, and estimated operating costs during a
representative average use cycle. (42 U.S.C. 6314(a)(1)) DOE has
determined that the amendments in this final rule would improve the
accuracy, reproducibility, and representativeness of test procedure
results, and will not be unduly burdensome for manufacturers to
conduct. DOE has determined that the amendments outlined in this final
rule will not require retesting or rerating of units.
Regarding the impact of EPA refrigerant regulation and other DOE
rulemaking actions on small businesses, DOE would consider the impact
on manufacturers of multiple product/equipment-specific regulatory
actions pursuant to section 13(g) in appendix A to subpart C of part
430, in any subsequent energy conservation standards rulemaking
analysis for WICFs.
RSG commented that it considers DOE's door, panel, and
refrigeration system cost estimates to be very low. For refrigeration
systems, RSG further stated that there are few outside labs capable of
testing to the degree that DOE requires. (RSG, No. 41 at p. 3) DOE
notes that the estimated test costs were based on actual laboratory
quotes, which DOE has determined are representative of the pricing
available to the industry as a whole. Additionally, DOE is aware of
third-party laboratories that have the capability to test to the
current DOE test procedure.
Doors
DOE has determined that retesting and recertification would not be
required for walk-in cooler and freezer doors as a result of this
rulemaking. DOE is adopting the following amendments to appendix A for
walk-in cooler and freezer doors:
1. Referencing NFRC 102-2020 for the determination of U-factor;
2. Including AEDM provisions for manufacturers to alternately
determine the total energy consumption of display and non-display
doors;
3. Providing additional detail for determining the area used to
convert U-factor into conduction load, As, to differentiate
it from the area used to determine compliance with the standards,
Add or And; and
4. Specifying a PTO value of 97 percent for door motors.
DOE has determined that these amendments would not increase testing
costs per basic model relative to the current DOE test procedure in
appendix A.\72\ Items 1 and 3, referencing NFRC
[[Page 28829]]
102-2020 and additional detail on the area used to convert U-factor
into a conduction load, improves the consistency, reproducibility, and
representativeness of test procedure results. Item 2, including AEDM
provisions, intends to provide manufacturers with the flexibility to
use an alternative method that gives the best agreement for their
doors. Item 4, by including a PTO value of 97 percent, intends to
provide a more representative and consistent means for comparison of
walk-in door performance for doors with motors.
---------------------------------------------------------------------------
\72\ DOE estimates the cost of one test to determine energy
consumption of a walk-in door, including one physical U-factor test
per NFRC 102-2020, to be $5,000. Per the sampling requirements
specified at 10 CFR 429.53(a)(3)(ii) and 429.11(b), manufacturers
are required to test at least two units to determine the rating for
a basic model, except where only one unit of the basic model is
produced.
---------------------------------------------------------------------------
DOE expects certification costs for door manufacturers would either
remain the same or be reduced, depending on whether manufacturers have
been able to achieve the agreement between U-factors simulated using
the method in NFRC 100 and U-factors tested using NFRC 102.
Manufacturers of doors that have been able to achieve the specified
agreement \73\ between U-factors simulated using the method in NFRC 100
and U-factors tested using NFRC 102 would be able to continue using the
simulation method in NFRC 100, provided that the simulation method also
meets the basic requirements proposed for an AEDM in 10 CFR 429.53 and
429.70(f). For manufacturers of doors that have not been able to
achieve the specified agreement between U-factors simulated using the
method in NFRC 100 and U-factors tested using NFRC 102, DOE estimates
that the test burden would decrease. With the new test procedure,
manufacturers who would have otherwise been required to physically test
every walk-in door basic model could develop an AEDM for rating their
basic models of walk-in doors consistent with the proposed provisions
in 10 CFR 429.53 and 429.70(f). DOE estimates the per-manufacturer cost
to develop and validate an AEDM for a single validation class of walk-
in doors to be $11,100, in addition to an estimated $1,600 to $5,000 in
shipping costs.\74\ DOE estimates an additional cost to determine
energy consumption of a walk-in door using an AEDM to be $46 per basic
model.\75\
---------------------------------------------------------------------------
\73\ Section 4.7.1 of NFRC 100 requires that the accepted
difference between the tested U-factor and the simulated U-factor be
(a) 0.03 Btu/(h-ft2 [deg]F) for simulated U-factors that are 0.3
Btu/(h-ft2 [deg]F) or less, or (b) 10 percent of the simulated U-
factor for simulated U-factors greater than 0.3 Btu/(h-ft2 [deg]F).
This agreement must match for the baseline product in a product
line. Per NFRC 100, the baseline product is the individual product
selected for validation; it is not synonymous with ``basic model''
as defined in 10 CFR 431.302.
\74\ DOE estimates that the shipping cost for a walk-in box,
typically made up of multiple panels and a door, from a
manufacturing facility to a test lab can range from $800 to $2,500
depending on the relative locations of the two facilities, the
weight and size of the unit being shipped, and the discounts
associated with shipping multiple units at one time. This means that
each estimated test cost would increase from $1,600 to $5,000
dollars when shipping a unit for test to and from a third-party lab.
\75\ DOE estimated initial costs to validate an AEDM assuming 24
hours of general time to develop and validate an AEDM based on
existing simulation tools. DOE estimated the cost of an engineering
calibration technician fully burdened wage of $46 per hour plus the
cost of third-party physical testing of two basic models per
proposed validation class. DOE estimated the additional per basic
model cost to determine efficiency using an AEDM assuming 1 hour per
basic model at the cost of an engineering calibration technician
wage of $46 per hour.
---------------------------------------------------------------------------
DOE expects that the additional detail provided for determining the
area used to convert U-factor into conduction load, As,
would not result in changes that require manufacturers to re-certify
equipment. Manufacturers would be able to rely on data generated under
the current test procedure for equipment already certified.
For walk-in doors with motors, DOE has determined that the
amendments described in section III of this final rule would either not
change the measured energy consumption or would result in a lower
measured energy consumption and therefore, would not require retesting
or recertification as a result of DOE's adoption of the amendments to
the test procedures. New testing is only required if the manufacturer
wishes to make claims using the new, more efficient rating.
Additionally, DOE has determined the amendments would not increase the
cost of testing for doors with motors.
DOE concludes that manufacturers of WICF doors, including small
manufacturers, will not incur retesting and recertification costs as a
result of this final rule.
Panels
In this final rule, DOE is amending the existing test procedure in
appendix B for measuring the R-value of insulation of panels by:
1. Incorporating by reference the updated version of the applicable
industry test method, ASTM C518-17;
2. Including provisions specific to measurement of test specimen
and total insulation thickness; and
3. Providing specifications for determining the parallelism and
flatness of the test specimen.
The first item incorporates by reference the most up-to-date
version of the industry standards currently referenced in the DOE test
procedure. Items 2 and 3 include additional instructions intended to
improve consistency and reproducibility of test procedure results.
DOE has concluded that the amendments will not change efficiency
ratings for walk-in panels, and therefore will not require rerating as
result of DOE's adoption of this amendment to the test procedure.
Therefore, DOE has determined that these amendments will not add any
additional testing costs to small business manufacturers of WICF
panels.
Refrigeration Systems
In this final rule, DOE is adopting changes to appendix C that DOE
has determined would improve the accuracy and reproducibility of the
test results and would not be unduly burdensome for manufacturers to
conduct. DOE has determined that these changes would not impact testing
cost. Additionally, the amended appendix C, measuring AWEF per AHRI
1250-2009, does not contain any changes that would require retesting or
rerating.
DOE is also adopting, through incorporations by reference, certain
provisions of AHRI 1250-2020 in appendix C1 that will amend the
existing test procedure for walk-in cooler and freezer refrigeration
systems. DOE notes that the new appendix C1, which establishes new
energy efficiency metric AWEF2, would increase testing costs for
certain refrigeration system equipment types. This final rule does not
require manufacturers to rate equipment using appendix C1. If DOE were
to adopt a future energy conservation standard using the AWEF2 metric,
that energy conversation standard will cause manufacturers to incur
costs for retesting and recertification at the time when the amended
standards take effect. The cost of retesting and recertification based
on appendix C1 would be incorporated into the analysis of the energy
conservation standard adopting the AWEF2 metric, should DOE choose to
establish standard using that metric.
Although this test procedure final rule does not require the use of
appendix C1 and manufacturers, including small manufacturers, will not
incur retesting or recertification costs based on the AWEF2 metric at
this time, DOE discusses the potential impacts of adopting certain
changes in the new appendix C1 in this section.
[[Page 28830]]
As discussed previously in this final rule, DOE is adopting off-
cycle test provisions in AHRI 1250-2020 for walk-in refrigeration
systems. The current test procedure requires off-cycle power to be
measured at the 95 [deg]F ambient condition. The new test procedure
requires off-cycle to be measured at 95 [deg]F, 59 [deg]F, and 35
[deg]F ambient conditions for outdoor dedicated condensing units,
outdoor matched pair systems, and outdoor dedicated systems. The
matched pair and single-packaged dedicated systems include high-
temperature refrigeration systems. When the waivers for these high-
temperature refrigeration systems were granted, only one off-cycle test
was required; therefore, manufacturers with waivers would be required
to conduct additional testing as compared to the alternate test
procedure currently required. DOE estimates that measuring off-cycle
power at these additional ambient conditions may increase third-party
lab test cost by $1,000 per unit to a total cost of $11,000 per unit
for outdoor dedicated condensing units, outdoor matched pair systems,
and outdoor single-packaged dedicated systems. The physical testing
cost would be $22,000 per basic model for outdoor dedicated condensing
units, outdoor matched pair systems, and outdoor single-packaged
dedicated systems, in addition to an estimated $1,000 to $4,000 in
round trip shipping costs.\76\
---------------------------------------------------------------------------
\76\ The cost to test one unit is $11,000, plus an estimated
$500 to $2,000 for shipping the refrigeration system to and from the
third-party lab. Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 429.11(b), manufacturers are required to test
at least two units to determine the rating for a basic model, except
where only one unit of the basic model is produced.
---------------------------------------------------------------------------
However, manufacturers are not required to perform laboratory
testing on all basic models. In accordance with 10 CFR 429.53, WICF
refrigeration system manufacturers may elect to use AEDMs. DOE
estimates the per-manufacturer cost to develop and validate an AEDM for
outdoor dedicated condensing units and outdoor matched pair systems to
be approximately $24,581,\77\ in addition to an estimated $1,000 to
$4,000 in round trip shipping costs.\78\ DOE estimates an additional
cost of approximately $46 per basic model \79\ for determining energy
efficiency of a given basic model using the validated AEDM.
---------------------------------------------------------------------------
\77\ Outdoor single-packaged systems are also impacted by the
proposed adoption of AHRI 1250-2020 single-packaged test procedure
for walk-in cooler and freezer refrigeration systems. The combined
potential cost increase for outdoor single-packaged systems is
presented in the next paragraph.
\78\ Shipping costs associated with third-party physical testing
of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)).
\79\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
DOE estimated the range of potential costs for the five small OEMs
that manufacture outdoor dedicated condensing units, outdoor matched
pair systems, and outdoor single-packaged dedicated systems. When
developing cost estimates for the small OEMs, DOE considers the cost to
update the existing AEDM simulation tool, the costs to validate the
AEDM through physical testing (including shipping costs to and from the
third-party laboratory), and the cost to rate basic models using the
AEDM. DOE assumes a high-cost scenario where manufacturers would be
required to develop AEDMs for six validation classes.
DOE estimates the impacts based on basic model counts and company
revenue. Table IV.1 summarizes DOE's estimates for the five identified
small businesses. On average, testing costs represent less than 1
percent of annual revenue for a typical small business.
As previously discussed, the procedure in appendix C1 would only
require retesting or recertification when and if a future energy
conservation standard takes effect.
Table IV.1--Potential Small Business Re-Rating Costs (2022$) as a Result
of Off-Cycle Refrigeration System Power Requirements
------------------------------------------------------------------------
Estimated
Re-rating annual Percent of
Small domestic OEM estimate revenue annual
($MM) ($MM) revenue
------------------------------------------------------------------------
Manufacturer 1................... 0.16 12.0 1.4
Manufacturer 2................... 0.16 110.3 0.1
Manufacturer 3................... 0.23 88.7 0.3
Manufacturer 4................... 0.16 116.2 0.1
Manufacturer 5................... 0.16 156.3 0.1
------------------------------------------------------------------------
As also discussed in the final rule, DOE is adopting the single-
packaged dedicated system test procedure for walk-ins in AHRI 1250-
2020. The procedure requires air enthalpy tests to be used as the
primary test method. In the current test procedure, single-packaged
dedicated systems use refrigerant enthalpy as the primary test method.
DOE does not estimate a difference in physical testing costs between
air and refrigerant enthalpy testing of single-packaged dedicated
systems. DOE estimates the per-unit third party lab test cost to be
$11,000 for outdoor single-packaged units and $6,500 for indoor single-
packaged units. The physical testing cost would be $22,000 per basic
model for outdoor single-packaged dedicated systems and $13,000 per
basic model for indoor package systems, in addition to an estimated
$1,000 to $4,000 in round trip shipping costs for each class.\80\
---------------------------------------------------------------------------
\80\ Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 429.11(b), manufacturers are required to test
at least two units to determine the rating for a basic model, except
where only one unit of the basic model is produced.
---------------------------------------------------------------------------
However, should a manufacturer choose to use an AEDM, it may incur
additional costs regarding the development and validation of new AEDMs
for single-packaged dedicated systems. DOE estimates the per
manufacturer cost to develop and validate an AEDM to be $24,580 for
outdoor single-packaged units and $15,580 for indoor single-packaged
units, in addition to an estimated $1,000 to $4,000 in round trip
shipping costs.\81\ DOE estimates an additional cost of
[[Page 28831]]
approximately $46 per basic model \82\ for determining energy
efficiency using the validated AEDM.
---------------------------------------------------------------------------
\81\ Shipping costs associated with third-party physical testing
of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)).
\82\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
DOE estimated the range of potential costs for the two domestic,
small OEMs that manufacture single-packaged dedicated systems. When
developing cost estimates for the small OEMs, DOE considered the cost
to update the existing AEDM simulation tool, the costs to validate the
AEDM through physical testing (including shipping costs to and from the
third-party laboratory), and the cost to rate basic models using the
AEDM.
Both small businesses manufacture indoor and outdoor, low- and
medium-temperature, single-packaged dedicated systems. One small
business manufactures 28 basic models of single-packaged dedicated
systems with an estimated annual revenue of $110 million. Therefore,
DOE estimates the associated re-rating costs for this manufacturer to
be approximately $91,250 when making use of AEDMs. The cost for this
manufacturer represents less than 1 percent of annual revenue.
The second small business manufactures 38 basic models of single-
packaged dedicated systems with an estimated annual revenue of $156
million. Therefore, DOE estimates the associated re-rating costs for
this manufacturer to be approximately $91,700 when making use of AEDMs.
The cost for this manufacturer represents less than 1 percent of annual
revenue.
As previously discussed, the procedure in appendix C1 would only
require retesting or recertification when and if a future energy
conservation standard takes effect.
As also discussed in this final rule, DOE is adopting test
procedures for CO2 unit coolers and high-temperature
refrigeration systems. DOE estimates that the average third-party lab
per unit test cost would be $11,000 for a high-temperature matched pair
or single-packaged dedicated system, $6,000 for a high-temperature unit
cooler tested alone, $6,500 for a low-temperature CO2 unit
cooler, and $6,000 for a medium-temperature CO2 unit cooler.
As discussed previously, DOE has granted waivers to certain
manufacturers for both high-temperature refrigeration systems and
CO2 unit coolers. The test procedures being adopted are
consistent with the alternate test procedures included in the granted
waivers. For those manufacturers who have been granted a test procedure
waiver for this equipment, DOE expects that there would be no
additional test burden. However, DOE expects that there would be
additional testing costs for any manufacturers of these products who
have not submitted or been granted a test procedure waiver at the time
this test procedure is finalized. DOE estimates these manufacturers may
incur rating expenses up to the following estimates, in addition to an
estimated $5,000 to $2,000 in shipping costs for each class.\83\
---------------------------------------------------------------------------
\83\ The cost to ship one unit to and from the third-party lab
is approximately $500 to $2,000. Per the sampling requirements
specified at 10 CFR 429.53(a)(2)(ii) and 429.11(b), manufacturers
are required to test at least two units to determine the rating for
a basic model, except where only one unit of the basic model is
produced.
---------------------------------------------------------------------------
$22,000 per basic model for a high-temperature matched
pair or single-packaged dedicated system; \84\
---------------------------------------------------------------------------
\84\ Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 429.11(b), manufacturers are required to test
at least two units to determine the rating for a basic model, except
where only one unit of the basic model is produced.
---------------------------------------------------------------------------
$12,000 per basic model for a high-temperature unit cooler
tested alone; \85\
---------------------------------------------------------------------------
\85\ Id.
---------------------------------------------------------------------------
$13,000 per basic model for a low-temperature
CO2 unit cooler; \86\ and
---------------------------------------------------------------------------
\86\ Id.
---------------------------------------------------------------------------
$12,000 per basic model for a medium-temperature
CO2 unit cooler.\87\
---------------------------------------------------------------------------
\87\ Id.
---------------------------------------------------------------------------
However, manufacturers are not required to perform laboratory
testing on all basic models. In accordance with 10 CFR 429.53, WICF
refrigeration system manufacturers may elect to use AEDMs. DOE
estimates the per-manufacturer cost to develop and validate an AEDM for
high-temperature systems and low- and medium-temperature CO2
unit coolers to be $24,580 per validation class, in addition to an
estimated $1,000 to $4,000 in round trip shipping costs.\88\ DOE
estimates an additional cost of approximately $46 per basic model \89\
for determining energy efficiency using the validated AEDM.
---------------------------------------------------------------------------
\88\ Shipping costs associated with third-party physical testing
of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)).
\89\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
DOE estimated the potential costs to manufacturers of high-
temperature units as a result of off-cycle requirements using an AEDM.
Specifically, DOE estimated the range of potential costs for the five
identified domestic, small OEMs that manufacture high-temperature
units. When developing cost estimates for the small OEMs, DOE considers
the cost to develop the AEDM simulation tool, the costs to validate the
AEDM through physical testing (including shipping costs to and from the
third-party laboratory), and the cost to rate basic models using the
AEDM. DOE assumes a scenario where manufacturers would be required to
develop AEDMs for three validation classes.
DOE estimated the impacts based on basic model counts and company
revenue. Table IV.2 summarizes DOE's estimates for the five identified
small businesses. On average, testing costs represent approximately 1.3
percent of annual revenue for a typical small business.
As previously discussed, the procedure in appendix C1 would only
require retesting or recertification when and if a future energy
conservation standard takes effect.
[[Page 28832]]
Table IV.2--Potential Small Business Re-Rating Costs (2022$) for High-
Temperature Refrigeration Systems
------------------------------------------------------------------------
Estimated
Re-rating annual Percent of
Small domestic OEM estimate revenue annual
($MM) ($MM) revenue
------------------------------------------------------------------------
Manufacturer A................... 0.089 3.9 2.3
Manufacturer B................... 0.088 3.6 2.5
Manufacturer C................... 0.089 11.5 0.8
Manufacturer D................... 0.091 10.8 0.8
Manufacturer E................... 0.089 208.0 0.0
------------------------------------------------------------------------
Manufacturers of CO2 unit coolers may also choose to
utilize an AEDM. Furthermore, AEDM unit cooler validation classes do
not distinguish between CO2 unit coolers and non-
CO2 unit coolers. Therefore, manufacturers of CO2
unit coolers may use the same validation classes as non-CO2
unit coolers.
On the basis that the adopted test procedure changes will not
require retesting and recertification, DOE certifies that this final
rule does not have a ``significant economic impact on a substantial
number of small entities,'' and that the preparation of a FRFA is not
warranted. DOE will transmit a certification and supporting statement
of factual basis to the Chief Counsel for Advocacy of the Small
Business Administration for review under 5 U.S.C. 605(b).
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of walk-ins must certify to DOE that their products
comply with any applicable energy conservation standards. To certify
compliance, manufacturers must first obtain test data for their
products according to the DOE test procedures, including any amendments
adopted for those test procedures. DOE has established regulations for
the certification and recordkeeping requirements for all covered
consumer products and commercial equipment, walk-ins. (See generally 10
CFR part 429.) The collection-of-information requirement for the
certification and recordkeeping is subject to review and approval by
OMB under the Paperwork Reduction Act (PRA). This requirement has been
approved by OMB under OMB Control Number 1910-1400. Public reporting
burden for the certification is estimated to average 35 hours per
response, including the time for reviewing instructions, searching
existing data sources, gathering and maintaining the data needed, and
completing and reviewing the collection of information.
DOE is not amending the certification or reporting requirements for
walk-ins in this final rule. Instead, DOE may consider proposals to
amend the certification requirements and reporting for walk-ins under a
separate rulemaking regarding appliance and equipment certification.
DOE will address changes to OMB Control Number 1910-1400 at that time,
as necessary.
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
D. Review Under the National Environmental Policy Act of 1969
In this final rule, DOE establishes test procedure amendments that
it expects will be used to develop and implement future energy
conservation standards for walk-ins. DOE has determined that this rule
falls into a class of actions that are categorically excluded from
review under the National Environmental Policy Act of 1969 (42 U.S.C.
4321 et seq.) and DOE's implementing regulations at 10 CFR part 1021.
Specifically, DOE has determined that adopting test procedures for
measuring energy efficiency of consumer products and industrial
equipment is consistent with activities identified in 10 CFR part 1021,
appendix A to subpart D, A5 and A6. Accordingly, neither an
environmental assessment nor an environmental impact statement is
required.
E. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 4,
1999), imposes certain requirements on agencies formulating and
implementing policies or regulations that preempt State law or that
have federalism implications. The Executive order requires agencies to
examine the constitutional and statutory authority supporting any
action that would limit the policymaking discretion of the States and
to carefully assess the necessity for such actions. The Executive order
also requires agencies to have an accountable process to ensure
meaningful and timely input by State and local officials in the
development of regulatory policies that have Federalism implications.
On March 14, 2000, DOE published a statement of policy describing the
intergovernmental consultation process it will follow in the
development of such regulations. 65 FR 13735. DOE examined this final
rule and determined that it will not have a substantial direct effect
on the States, on the relationship between the National Government and
the States, or on the distribution of power and responsibilities among
the various levels of government. EPCA governs and prescribes Federal
preemption of State regulations as to energy conservation for the
equipment that are the subject of this final rule. States can petition
DOE for exemption from such preemption to the extent, and based on
criteria, set forth in EPCA. (42 U.S.C. 6297(d)) No further action is
required by Executive Order 13132.
F. Review Under Executive Order 12988
Regarding the review of existing regulations and the promulgation
of new regulations, section 3(a) of Executive Order 12988, ``Civil
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal
agencies the general duty to adhere to the following requirements: (1)
eliminate drafting errors and ambiguity; (2) write regulations to
minimize litigation; (3) provide a clear legal standard for affected
conduct rather than a general standard; and (4) promote simplification
and burden reduction. Section 3(b) of Executive Order 12988
specifically requires that Executive agencies make every reasonable
effort to ensure that the regulation (1) clearly specifies the
preemptive effect, if any; (2) clearly specifies any effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct while promoting simplification and
[[Page 28833]]
burden reduction; (4) specifies the retroactive effect, if any; (5)
adequately defines key terms; and (6) addresses other important issues
affecting clarity and general draftsmanship under any guidelines issued
by the Attorney General. Section 3(c) of Executive Order 12988 requires
Executive agencies to review regulations in light of applicable
standards in sections 3(a) and 3(b) to determine whether they are met
or it is unreasonable to meet one or more of them. DOE has completed
the required review and determined that, to the extent permitted by
law, this final rule meets the relevant standards of Executive Order
12988.
G. Review Under the Unfunded Mandates Reform Act of 1995
Title II of the Unfunded Mandates Reform Act of 1995 (``UMRA'')
requires each Federal agency to assess the effects of Federal
regulatory actions on State, local, and Tribal governments and the
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531).
For a regulatory action resulting in a rule that may cause the
expenditure by State, local, and Tribal governments, in the aggregate,
or by the private sector of $100 million or more in any one year
(adjusted annually for inflation), section 202 of UMRA requires a
Federal agency to publish a written statement that estimates the
resulting costs, benefits, and other effects on the national economy.
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to
develop an effective process to permit timely input by elected officers
of State, local, and Tribal governments on a proposed ``significant
intergovernmental mandate,'' and requires an agency plan for giving
notice and opportunity for timely input to potentially affected small
governments before establishing any requirements that might
significantly or uniquely affect small governments. On March 18, 1997,
DOE published a statement of policy on its process for
intergovernmental consultation under UMRA. 62 FR 12820; also available
at www.energy.gov/gc/office-general-counsel. DOE examined this final
rule according to UMRA and its statement of policy and determined that
the rule contains neither an intergovernmental mandate, nor a mandate
that may result in the expenditure of $100 million or more in any year,
so these requirements do not apply.
H. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family
Policymaking Assessment for any rule that may affect family well-being.
This final rule will not have any impact on the autonomy or integrity
of the family as an institution. Accordingly, DOE has concluded that it
is not necessary to prepare a Family Policymaking Assessment.
I. Review Under Executive Order 12630
DOE has determined, under Executive Order 12630, ``Governmental
Actions and Interference with Constitutionally Protected Property
Rights,'' 53 FR 8859 (March 18, 1988), that this regulation will not
result in any takings that might require compensation under the Fifth
Amendment to the U.S. Constitution.
J. Review Under Treasury and General Government Appropriations Act,
2001
Section 515 of the Treasury and General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most
disseminations of information to the public under guidelines
established by each agency pursuant to general guidelines issued by
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). Pursuant
to OMB Memorandum M-19-15, Improving Implementation of the Information
Quality Act (April 24, 2019), DOE published updated guidelines which
are available at www.energy.gov/sites/prod/files/2019/12/f70/DOE%20Final%20Updated%20IQA%20Guidelines%20Dec%202019.pdf. DOE has
reviewed this final rule under the OMB and DOE guidelines and has
concluded that it is consistent with applicable policies in those
guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355
(May 22, 2001), requires Federal agencies to prepare and submit to OMB,
a Statement of Energy Effects for any significant energy action. A
``significant energy action'' is defined as any action by an agency
that promulgated or is expected to lead to promulgation of a final
rule, and that (1) is a significant regulatory action under Executive
Order 12866, or any successor order; and (2) is likely to have a
significant adverse effect on the supply, distribution, or use of
energy; or (3) is designated by the Administrator of OIRA as a
significant energy action. For any significant energy action, the
agency must give a detailed statement of any adverse effects on energy
supply, distribution, or use if the regulation is implemented, and of
reasonable alternatives to the action and their expected benefits on
energy supply, distribution, and use.
This regulatory action is not a significant regulatory action under
Executive Order 12866. Moreover, it would not have a significant
adverse effect on the supply, distribution, or use of energy, nor has
it been designated as a significant energy action by the Administrator
of OIRA. Therefore, it is not a significant energy action, and,
accordingly, DOE has not prepared a Statement of Energy Effects.
L. Review Under Section 32 of the Federal Energy Administration Act of
1974
Under section 301 of the Department of Energy Organization Act
(Pub. L. 95-91; 42 U.S.C. 7101), DOE must comply with section 32 of the
Federal Energy Administration Act of 1974, as amended by the Federal
Energy Administration Authorization Act of 1977. (15 U.S.C. 788;
``FEAA'') Section 32 essentially provides in relevant part that, where
a rule authorizes or requires use of commercial standards, the
rulemaking must inform the public of the use and background of such
standards. In addition, section 32(c) requires DOE to consult with the
Attorney General and the Chairman of the Federal Trade Commission
(``FTC'') concerning the impact of the commercial or industry standards
on competition.
The modifications to the test procedure for walk-ins adopted in
this final rule incorporates testing methods contained in certain
sections of the following commercial standards: NFRC 102-2020, ASTM
C1199-14, ASTM C518-17, AHRI 1250-2020, AHRI 1250-2020, ANSI/ASHRAE 37-
2009, and ANSI/ASHRAE 16-2016. DOE has evaluated these standards and is
unable to conclude whether it fully complies with the requirements of
section 32(b) of the FEAA (i.e., whether it was developed in a manner
that fully provides for public participation, comment, and review). DOE
has consulted with both the Attorney General and the Chairman of the
FTC about the impact on competition of using the methods contained in
these standards.
M. Congressional Notification
As required by 5 U.S.C. 801, DOE will report to Congress on the
promulgation of this rule before its effective date. The report will
state that it has been determined that the rule is not a ``major rule''
as defined by 5 U.S.C. 804(2).
[[Page 28834]]
N. Description of Materials Incorporated by Reference
AHRI Standard 1250 (I-P)-2009 is an industry-accepted test
procedure for measuring the performance of walk-in cooler and walk-in
freezer refrigeration systems. Specifically, the test procedure
codified by this final rule references AHRI 1250-2009 for testing walk-
in refrigeration units. AHRI 1250-2009 is reasonably available on
AHRI's website at www.ahrinet.org/standards/search-standards.
AHRI Standard 1250-2020 is an industry-accepted test procedure for
measuring the performance of walk-in cooler and walk-in freezer
refrigeration systems. Specifically, the test procedure codified by
this final rule references AHRI 1250-2020 for testing walk-in
refrigeration units. AHRI 1250-2020 is reasonably available on AHRI's
website at www.ahrinet.org/standards/search-standards.
ANSI/AHRI Standard 420-2008 is an industry-accepted test procedure
for rating the performance of forced-circulation free-delivery unit
coolers for refrigeration and is referenced by AHRI 1250-2009.
Specifically, the test procedure codified by this final rule references
AHRI 420-2008 for the information that should be recorded when testing
unit coolers. AHRI 420-2008 is reasonably available on AHRI's website
at www.ahrinet.org/standards/search-standards.
ANSI/ASHRAE Standard 16-2016 is an industry-accepted test procedure
for measuring cooling and heating capacity of room air conditioners,
packaged terminal air conditioners, and packaged terminal heat pumps
and is referenced by AHRI 1250-2020. Specifically, the test procedure
codified by this final rule references ANSI/ASHRAE 16-2016 for test
provisions related the capacity measurement of single-packaged
dedicated systems for the appendix C1 test procedure. ANSI/ASHRAE 16-
2016 is reasonably available on ASHRAE's website at www.ashrae.org.
ANSI/ASHRAE Standard 23.1-2010 is an industry-accepted test
procedure for rating the performance of positive displacement
refrigerant compressors and condensing units that operate at
refrigerant subcritical temperatures and is referenced by AHRI 1250-
2009 and AHRI 1250-2020. Specifically, the test procedure codified by
this final rule references ANSI/ASHRAE 23.1-2010 for test provisions
related to capacity measurement of condensing units using the
compressor calibration method. ANSI/ASHRAE 23.1-2010 is reasonably
available on ASHRAE's website at www.ashrae.org.
ANSI/ASHRAE Standard 37-2009 is an industry-accepted test procedure
for testing and rating air-conditioning and heat pump equipment and is
referenced by AHRI 1250-2020. Specifically, the test procedure codified
by this final rule references ANSI/ASHRAE 37-2009 for test provisions
related to capacity measurement of single-packaged dedicated systems
for the appendix C1 test procedure. ANSI/ASHRAE 37-2009 is reasonably
available on ASHRAE's website at www.ashrae.org.
ANSI/ASHRAE Standard 41.1-2013 is an industry-accepted test
procedure for measuring temperature and is referenced by AHRI 1250-
2020. Specifically, the test procedure codified by this final rule
references ANSI/ASHRAE 41.1-2013 for temperature measurements for all
refrigeration unit tests. ANSI/ASHRAE 41.1-2013 is reasonably available
on ASHRAE's website at www.ashrae.org.
ANSI/ASHRAE Standard 41.3-2014 is an industry-accepted test
procedure for measuring pressure and is referenced by AHRI 1250-2020.
Specifically, the test procedure codified by this final rule references
ANSI/ASHRAE 41.3-2014 for pressure measurements for all refrigeration
unit tests. ANSI/ASHRAE 41.3-12014 is reasonably available on ASHRAE's
website at www.ashrae.org.
ANSI/ASHRAE Standard 41.6-2014 is an industry-accepted test
procedure for measuring humidity and is referenced by AHRI 1250-2020.
Specifically, the test procedure codified by this final rule references
ANSI/ASHRAE 41.6-2014 for test provisions related to capacity
measurement of single-packaged dedicated systems for the appendix C1
test procedure. ANSI/ASHRAE 41.6-2014 is reasonably available on
ASHRAE's website at www.ashrae.org.
ANSI/ASHRAE Standard 41.10-2013 is an industry-accepted test
procedure for measuring the mass flow of volatile refrigerants with
flowmeter test methods and is referenced by AHRI 1250-2020.
Specifically, the test procedure codified by this final rule references
ANSI/ASHRAE 41.10-2013 for measuring the flow rates of volatile
refrigerants with flow meters for all refrigeration unit tests. ANSI/
ASHRAE 41.10-2013 is reasonably available on ASHRAE's website at
www.ashrae.org.
ASTM C518-17 is an industry-accepted test procedure for measuring
thermal transmission properties using a heat flow meter apparatus.
Specifically, the test procedure codified by this final rule references
ASTM C518-17 for testing walk-in envelope components. ASTM C518-17 is
reasonably available on ASTM's website at www.astm.org.
ASTM C1199-14 is an industry-accepted test procedure for measuring
the steady state thermal transmittance of fenestration systems and is
referenced by NFRC 102-2020. Specifically, the test procedure codified
by this final rule references ASTM C1199-14 for testing walk-in
envelope components. ASTM C1199-14 is reasonably available on ASTM's
website at www.astm.org.
NFRC 102-2020 [E0A0], is an industry-accepted test procedure for
measuring the steady state thermal transmittance of fenestration
systems. Specifically, the test procedure codified by this final rule
references NFRC 102-2020 for testing walk-in envelope components. NFRC
102-2020 is reasonably available on NFRC's website at www.nfrc.org.
V. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this final
rule.
List of Subjects
10 CFR Part 429
Administrative practice and procedure, Confidential business
information, Energy conservation, Household appliances, Imports,
Intergovernmental relations, Reporting and recordkeeping requirements,
Small businesses.
10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Energy conservation test procedures, Incorporation by
reference, Reporting and recordkeeping requirements.
Signing Authority
This document of the Department of Energy was signed on April 12,
2023, by Francisco Alejandro Moreno, Acting Assistant Secretary for
Energy Efficiency and Renewable Energy, pursuant to delegated authority
from the Secretary of Energy. That document with the original signature
and date is maintained by DOE. For administrative purposes only, and in
compliance with requirements of the Office of the Federal Register, the
undersigned DOE Federal Register Liaison Officer has been authorized to
sign and submit the document in electronic format for publication, as
an official document of the Department of Energy. This administrative
process in no way alters the legal effect of this document upon
publication in the Federal Register.
[[Page 28835]]
Signed in Washington, DC, on April 12, 2023.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
For the reasons stated in the preamble, DOE is amending parts 429
and 431 of chapter II of title 10, Code of Federal Regulations as set
forth below:
PART 429--CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER
PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT
0
1. The authority citation for part 429 continues to read as follows:
Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.
0
2. Amend Sec. 429.53 by revising paragraphs (a)(2)(i) and (a)(3) and
adding paragraph (a)(4) to read as follows:
Sec. 429.53 Walk-in coolers and walk-in freezers.
(a) * * *
(2) * * *
(i) Applicable test procedure. If AWEF or AWEF2 is determined by
testing, test according to the applicable provisions of Sec.
431.304(b) of this chapter with the following equipment-specific
provisions.
(A) Dedicated condensing units. Outdoor dedicated condensing
refrigeration systems that are also designated for use in indoor
applications must be tested and rated as both an outdoor dedicated
condensing refrigeration system and an indoor dedicated refrigeration
system.
(B) Matched refrigeration systems. A matched refrigeration system
is not required to be rated if the constituent unit cooler(s) and
dedicated condensing unit have been tested as specified in Sec.
431.304(b)(4) of this chapter. However, if a manufacturer wishes to
represent the efficiency of the matched refrigeration system as
distinct from the efficiency of either constituent component, or if the
manufacturer cannot rate one or both of the constituent components
using the specified method, the manufacturer must test and rate the
matched refrigeration system as specified in Sec. 431.304(b)(4) of
this chapter.
(C) Detachable single-packaged dedicated systems. Detachable
single-packaged dedicated systems must be tested and rated as a single-
packaged dedicated systems using the test procedure in Sec.
431.304(b)(4) of this chapter.
(D) Attached split systems. Attached split systems must be tested
and rated as dedicated condensing units and unit coolers using the test
procedure in Sec. 431.304(b)(4) of this chapter.
* * * * *
(3) For each basic model of walk-in cooler and walk-in freezer
display and non-display door, the daily energy consumption must be
determined by testing, in accordance with Sec. 431.304 of this chapter
and the provisions of this section, or by application of an AEDM that
meets the requirements of Sec. 429.70 and the provisions of this
section.
(i) Applicable test procedure. Prior to October 31, 2023 use the
test procedure for walk-ins in 10 CFR part 431, subpart R, appendix A,
revised as of January 1, 2022, to determine daily energy consumption.
Beginning October 31, 2023, use the test procedure in part 431, subpart
R, appendix A of this chapter to determine daily energy consumption.
(ii) Units to be tested. For each basic model, a sample of
sufficient size shall be randomly selected and tested to ensure that
any represented value of daily energy consumption of a basic model or
other measure of energy use for which consumers would favor lower
values shall be greater than or equal to the higher of:
(A) The mean of the sample, where:
Equation 3 to Paragraph (a)(3)(ii)(A)
[GRAPHIC] [TIFF OMITTED] TR04MY23.000
And x is the sample mean, n is the number of samples, and
xi is the ith sample; or,
(B) The upper 95 percent confidence limit (UCL) of the true mean
divided by 1.05, where:
Equation 4 to Paragraph (a)(3)(ii)(B)
[GRAPHIC] [TIFF OMITTED] TR04MY23.001
And x is the sample mean, s is the sample standard deviation; n is
the number of samples, and t-0.95 is the statistic for a 95
percent one-tailed confidence interval with n-1 degrees of freedom
(from appendix A to this subpart).
(4) For each basic model of walk-in cooler and walk-in freezer
panel and non-display door, the R-value must be determined by testing,
in accordance with Sec. 431.304 of this chapter and the provisions of
this section.
(i) Applicable test procedure. Prior to October 31, 2023, use the
test procedure for walk-ins in 10 CFR part 431, subpart R, appendix B,
revised as of January 1, 2022, to determine R-value. Beginning October
31, 2023, use the test procedure in appendix B to subpart R of part 431
of this chapter to determine R-value.
(ii) Units to be tested. For each basic model, a sample of
sufficient size shall be randomly selected and tested to ensure that
any represented value of R-value or other measure of efficiency of a
basic model for which consumers would favor higher values shall be less
than or equal to the lower of:
(A) The mean of the sample, where:
Equation 5 to Paragraph (a)(4)(ii)(A)
[GRAPHIC] [TIFF OMITTED] TR04MY23.002
And x is the sample mean, n is the number of samples, and
xi is the ith sample; or,
(B) The lower 95 percent confidence limit (LCL) of the true mean
divided by 0.95, where:
Equation 6 to Paragraph (a)(4)(ii)(B)
[GRAPHIC] [TIFF OMITTED] TR04MY23.003
And x is the sample mean, s is the sample standard deviation; n is
the number of samples, and t-0.95 is the statistic for a 95
percent one-tailed confidence interval with n-1 degree of freedom (from
appendix A to this subpart).
* * * * *
0
3. Amend Sec. 429.70 by:
0
a. Adding a heading for the table in paragraph (c)(5)(viii)(A);
0
b. Renumbering tables 7 and 8 in paragraphs (m)(5)(vi) and
(m)(5)(viii)(A), respectively, as tables 9 and 10;
0
c. Revising the heading to paragraph (f) and paragraphs (f)(2)(ii)(A)
and (B);
0
d. Adding paragraphs (f)(2)(ii)(C) and (f)(2)(iii)(E);
0
e. Revising paragraphs (f)(2)(iv) and (f)(5)(vi); and
0
f. Adding a heading for the table in paragraph (h)(2)(iv).
The revisions and additions read as follows:
Sec. 429.70 Alternative methods for determining energy efficiency and
energy use.
* * * * *
(c) * * *
(5) * * *
(viii) * * *
(A) * * *
Table 3 to Paragraph (c)(5)(viii)(A)
* * * * *
(f) Alternative efficiency determination method (AEDM) for walk-
[[Page 28836]]
in refrigeration systems and doors-- * * *
(2) * * *
(ii) * * *
(A) For refrigeration systems, which are subject to an energy
efficiency metric, the predicted efficiency for each model calculated
by applying the AEDM may not be more than five percent greater than the
efficiency determined from the corresponding test of the model.
(B) For doors, which are subject to an energy consumption metric
the predicted daily energy consumption for each model calculated by
applying the AEDM may not be more than five percent less than the daily
energy consumption determined from the corresponding test of the model.
(C) The predicted energy efficiency or energy consumption for each
model calculated by applying the AEDM must meet or exceed the
applicable federal energy conservation standard.
(iii) * * *
(E) For rating doors, an AEDM may not simulate or model components
of the door that are not required to be tested by the DOE test
procedure. That is, if the test results used to validate the AEDM are
for the U-factor test of the door, the AEDM must estimate the daily
energy consumption, specifically the conduction thermal load, and the
direct and indirect electrical energy consumption, using the nominal
values and calculation procedure specified in the DOE test procedure.
(iv) WICF validation classes--(A) Doors.
Table 4 to Paragraph (f)(2)(iv)(A)
------------------------------------------------------------------------
Minimum number of
Validation class distinct models that must
be tested
------------------------------------------------------------------------
Display Doors, Medium Temperature............ 2 Basic Models.
Display Doors, Low Temperature............... 2 Basic Models.
Non-display Doors, Medium Temperature........ 2 Basic Models.
Non-display Doors, Low Temperature........... 2 Basic Models.
------------------------------------------------------------------------
(B) Refrigeration systems. (1) For representations made prior to
the compliance date of revised energy conservation standards for walk-
in cooler and walk-in freezer refrigeration systems, use the following
validation classes.
Table 5 to Paragraph (f)(2)(iv)(B)(1)
------------------------------------------------------------------------
Minimum number of
Validation class distinct models that must
be tested
------------------------------------------------------------------------
Dedicated Condensing, Medium Temperature, 2 Basic Models.
Matched Pair Indoor System.
Dedicated Condensing, Medium Temperature, 2 Basic Models.
Matched Pair Outdoor System \1\.
Dedicated Condensing, Low Temperature, 2 Basic Models.
Matched Pair Indoor System.
Dedicated Condensing, Low Temperature, 2 Basic Models.
Matched Pair Outdoor System \1\.
Unit Cooler, High-temperature................ 2 Basic Models.
Unit Cooler, Medium Temperature.............. 2 Basic Models.
Unit Cooler, Low Temperature................. 2 Basic Models.
Medium Temperature, Indoor Condensing Unit... 2 Basic Models.
Medium Temperature, Outdoor Condensing Unit 2 Basic Models.
\1\.
Low Temperature, Indoor Condensing Unit...... 2 Basic Models.
Low Temperature, Outdoor Condensing Unit \1\. 2 Basic Models.
------------------------------------------------------------------------
\1\ AEDMs validated for an outdoor class by testing only outdoor models
of that class may be used to determine representative values for the
corresponding indoor class, and additional validation testing is not
required. AEDMs validated only for a given indoor class by testing
indoor models or a mix of indoor and outdoor models may not be used to
determine representative values for the corresponding outdoor class.
(2) For representations made on or after the compliance date of
revised energy conservation standards for walk-in cooler and walk-in
freezer refrigeration systems, use the following validation classes.
Table 6 to Paragraph (f)(2)(iv)(B)(2)
------------------------------------------------------------------------
Minimum number of
Validation class distinct models that must
be tested
------------------------------------------------------------------------
Dedicated Condensing Unit, Medium 2 Basic Models.
Temperature, Indoor System.
Dedicated Condensing Unit, Medium 2 Basic Models.
Temperature, Outdoor System \1\.
Dedicated Condensing Unit, Low Temperature, 2 Basic Models.
Indoor System.
Dedicated Condensing Unit, Low Temperature, 2 Basic Models.
Outdoor System \1\.
Single-packaged Dedicated Condensing, High- 2 Basic Models.
temperature, Indoor System.
Single-packaged Dedicated Condensing, High- 2 Basic Models.
temperature, Outdoor System \1\.
Single-packaged Dedicated Condensing, Medium 2 Basic Models.
Temperature, Indoor System.
Single-packaged Dedicated Condensing, Medium 2 Basic Models.
Temperature, Outdoor System \1\.
Single-packaged Dedicated Condensing, Low 2 Basic Models.
Temperature, Indoor System.
Single-packaged Dedicated Condensing, Low 2 Basic Models.
Temperature, Indoor System \1\.
Matched Pair, High-temperature, Indoor 2 Basic Models.
Condensing Unit.
Matched Pair, High-temperature, Outdoor 2 Basic Models.
Condensing Unit \1\.
Matched Pair, Medium Temperature, Indoor 2 Basic Models.
Condensing Unit.
Matched Pair, Medium Temperature, Outdoor 2 Basic Models.
Condensing Unit \1\.
[[Page 28837]]
Matched Pair, Low Temperature, Indoor 2 Basic Models.
Condensing Unit.
Matched Pair, Low Temperature, Outdoor 2 Basic Models.
Condensing Unit \1\.
Unit Cooler, High-temperature................ 2 Basic Models.
Unit Cooler, Medium Temperature.............. 2 Basic Models.
Unit Cooler, Low Temperature................. 2 Basic Models.
------------------------------------------------------------------------
\1\ AEDMs validated for an outdoor class by testing only outdoor models
of that class may be used to determine representative values for the
corresponding indoor class, and additional validation testing is not
required. AEDMs validated only for a given indoor class by testing
indoor models or a mix of indoor and outdoor models may not be used to
determine representative values for the corresponding outdoor class.
* * * * *
(5) * * *
(vi) Tolerances. For efficiency metrics, the result from a DOE
verification test must be greater than or equal to the certified rating
x (1-the applicable tolerance). For energy consumption metrics, the
result from a DOE verification test must be less than or equal to the
certified rating x (1 + the applicable tolerance).
Table 7 to Paragraph (f)(5)(iv)
------------------------------------------------------------------------
Applicable
Equipment Metric tolerance (%)
------------------------------------------------------------------------
Refrigeration systems (including AWEF/AWEF2.......... 5
components).
Doors............................. Daily Energy 5
Consumption.
------------------------------------------------------------------------
* * * * *
(h) * * *
(2) * * *
(iv) * * *
Table 8 to Paragraph (h)(2)(iv)
* * * * *
0
4. Amend Sec. 429.110 by revising paragraph (e)(2) to read as follows:
Sec. 429.110 Enforcement testing.
* * * * *
(e) * * *
(2) For automatic commercial ice makers; commercial refrigerators,
freezers, and refrigerator-freezers; refrigerated bottled or canned
vending machines; commercial air conditioners and heat pumps;
commercial packaged boilers; commercial warm air furnaces; commercial
water heating equipment; and walk-in cooler and walk-in freezer doors,
panels, and refrigeration systems, DOE will use an initial sample size
of not more than four units and follow the sampling plans in appendix B
to this subpart.
* * * * *
0
5. Amend Sec. 429.134 by adding introductory text to paragraph (q) and
revising paragraphs (q)(2) and (4) to read as follows:
Sec. 429.134 Product-specific enforcement provisions.
* * * * *
(q) * * * Prior to October 31, 2023, the provisions in 10 CFR
429.134, revised as of January 1, 2022, are applicable. On and after
October 31, 2023, the following provisions apply.
* * * * *
(2) Verification of refrigeration system net capacity. The net
capacity of the refrigeration system basic model will be measured
pursuant to the test requirements of part 431, subpart R, appendix C of
this chapter for each unit tested on and after October 31, 2023, but
before the compliance date of revised energy conservation standards for
walk-in cooler and walk-in freezer refrigeration systems. The net
capacity of the refrigeration system basic model will be measured
pursuant to the test requirements of part 431, subpart R, appendix C1
of this chapter for each unit tested on and after the compliance date
of revised energy conservation standards for walk-in cooler and walk-in
freezer refrigeration systems. The results of the measurement(s) will
be averaged and compared to the value of net capacity certified by the
manufacturer. The certified net capacity will be considered valid only
if the average measured net capacity is within plus or minus five
percent of the certified net capacity.
* * * * *
(4) Verification of door electricity-consuming device power. For
each basic model of walk-in cooler and walk-in freezer door, DOE will
calculate the door's energy consumption using the input power listed on
the nameplate of each electricity-consuming device shipped with the
door. If an electricity-consuming device shipped with a walk-in door
does not have a nameplate or the nameplate does not list the device's
input power, then DOE will use the device's rated input power included
in the door's certification report. If the door is not certified or if
the certification does not include a rated input power for an
electricity-consuming device shipped with a walk-in door, DOE will use
the measured input power. DOE also may validate the power listed on the
nameplate or the rated input power by measuring it when energized using
a power supply that provides power within the allowable voltage range
listed on the component nameplate or the door nameplate, whichever is
available. If the measured input power is more than 10 percent higher
than the input power listed on the nameplate or the rated input power,
as appropriate, then the measured input power shall be used in the
door's energy consumption calculation.
(i) For electricity-consuming devices with controls, the maximum
input wattage observed while energizing the device and activating the
control shall be considered the measured input power. For anti-sweat
heaters that are controlled based on humidity levels, the control may
be activated by increasing relative humidity in the region of the
controls without damaging the sensor. For lighting fixtures that are
controlled with motion sensors, the control may be activated by
simulating motion in the vicinity of the sensor. Other kinds of
controls may be activated based on the functions of their sensor.
[[Page 28838]]
(ii) [Reserved]
* * * * *
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
6. The authority citation for part 431 continues to read as follows:
Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.
0
7. Amend Sec. 431.302 by:
0
a. Adding, in alphabetical order, definitions for ``Attached split
system,'' ``CO2 unit cooler,'' and ``Detachable single-
packaged dedicated system'';
0
b. Revising the definition for ``Door'';
0
c. Adding, in alphabetical order, definitions for ``Door leaf,'' ``Door
surface area,'' ``Ducted fan coil unit,'' ``Ducted multi-circuit
single-packaged dedicated system,'' ``Ducted single-packaged dedicated
system,'' ``High-temperature refrigeration system,'' ``Multi-circuit
single-packaged dedicated system,'' and ``Non-display door''; and
0
d. Revising the definition of ``Walk-in cooler and walk-in freezer''.
The additions and revisions read as follows:
Sec. 431.302 Definitions concerning walk-in coolers and walk-in
freezers.
* * * * *
Attached split system means a matched pair refrigeration system
which is designed to be installed with the evaporator entirely inside
the walk-in enclosure and the condenser entirely outside the walk-in
enclosure, and the evaporator and condenser are permanently connected
with structural members extending through the walk-in wall.
* * * * *
CO2 unit cooler means a unit cooler that includes a
nameplate listing only CO2 as an approved refrigerant.
* * * * *
* * * * *
Detachable single-packaged dedicated system means a system
consisting of a dedicated condensing unit and an insulated evaporator
section in which the evaporator section is designed to be installed
external to the walk-in enclosure and circulating air through the
enclosure wall, and the condensing unit is designed to be installed
either attached to the evaporator section or mounted remotely with a
set of refrigerant lines connecting the two components.
* * * * *
Door means an assembly installed in an opening on an interior or
exterior wall that is used to allow access or close off the opening and
that is movable in a sliding, pivoting, hinged, or revolving manner of
movement. For walk-in coolers and walk-in freezers, a door includes the
frame (including mullions), the door leaf or multiple leaves (including
glass) within the frame, and any other elements that form the assembly
or part of its connection to the wall.
Door leaf means the pivoting, rolling, sliding, or swinging portion
of a door.
Door surface area means the product of the height and width of a
walk-in door measured external to the walk-in. The height and width
dimensions shall be perpendicular to each other and parallel to the
wall or panel of the walk-in to which the door is affixed. The height
and width measurements shall extend to the edge of the frame and frame
flange (as applicable) to which the door is affixed. For sliding doors,
the height and width measurements shall include the track; however, the
width (for horizontal sliding doors) or the height (for vertical
sliding doors) shall be truncated to the external width or height of
the door leaf or leaves and its frame or casings. The surface area of a
display door is represented as Add and the surface area of a non-
display door is represented as And.
Ducted fan coil unit means an assembly, including means for forced
air circulation capable of moving air against both internal and non-
zero external flow resistance, and elements by which heat is
transferred from air to refrigerant to cool the air, with provision for
ducted installation.
Ducted multi-circuit single-packaged dedicated system means a
ducted single-packaged dedicated system or a ducted single-packaged
dedicated system (as defined in this section) that contains two or more
refrigeration circuits that refrigerate a single stream of circulated
air.
Ducted single-packaged dedicated system means a refrigeration
system (as defined in this section) that is a single-packaged assembly
designed for use with ducts, that includes one or more compressors, a
condenser, a means for forced circulation of refrigerated air, and
elements by which heat is transferred from air to refrigerant.
* * * * *
High-temperature refrigeration system means a refrigeration system
which is not designed to operate below 45 [deg]F.
* * * * *
Multi-circuit single-packaged dedicated system means a single-
packaged dedicated system or a ducted single-packaged dedicated system
(as defined in this section) that contains two or more refrigeration
circuits that refrigerate a single stream of circulated air.
Non-display door means a door that is not a display door.
* * * * *
Walk-in cooler and walk-in freezer means an enclosed storage space
including, but not limited to, panels, doors, and refrigeration system,
refrigerated to temperatures, respectively, above, and at or below 32
degrees Fahrenheit that can be walked into, and has a total chilled
storage area of less than 3,000 square feet; however, the terms do not
include products designed and marketed exclusively for medical,
scientific, or research purposes.
* * * * *
0
8. Revise Sec. 431.303 as follows:
Sec. 431.303 Materials incorporated by reference.
(a) Certain material is incorporated by reference into this subpart
with the approval of the Director of the Federal Register in accordance
with 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other
than that specified in this section, the U.S. Department of Energy
(DOE) must publish a document in the Federal Register and the material
must be available to the public. All approved incorporation by
reference (IBR) material is available for inspection at DOE, and at the
National Archives and Records Administration (NARA). Contact DOE at:
the U.S. Department of Energy, Office of Energy Efficiency and
Renewable Energy, Building Technologies Program, Sixth Floor, 950
L'Enfant Plaza SW, Washington, DC 20024, (202) 586-9127,
[email protected], www.energy.gov/eere/buildings/building-technologies-office. For information on the availability of this
material at NARA, email: [email protected], or go to:
www.archives.gov/federal-register/cfr/ibr-locations.html. The material
may be obtained from the sources in the following paragraphs of this
section.
(b) AHRI. Air-Conditioning, Heating, and Refrigeration Institute,
2111 Wilson Boulevard, Suite 500, Arlington, VA 22201; (703) 600-0366;
www.ahrinet.org.
(1) ANSI/AHRI Standard 420-2008 (``AHRI 420-2008''), Performance
Rating of Forced-Circulation Free-Delivery Unit Coolers for
Refrigeration, Copyright 2008; IBR approved for appendix C to subpart
R.
(2) AHRI Standard 1250P (I-P)-2009 (``AHRI 1250-2009''), Standard
for Performance Rating of Walk-in Coolers
[[Page 28839]]
and Freezers, (including Errata sheet dated December 2015), copyright
2009, except Table 15 and Table 16; IBR approved for appendix C to
subpart R.
(3) AHRI Standard 1250 (``AHRI 1250-2020''), Standard for
Performance Rating of Walk-in Coolers and Freezers, copyright 2020; IBR
approved for appendix C1 to subpart R.
(c) ASHRAE. American Society of Heating, Refrigerating and Air-
Conditioning Engineers, 180 Technology Parkway, Peachtree Corners, GA
30092; (404) 636-8400; www.ashrae.org.
(1) ANSI/ASHRAE Standard 16-2016 (``ANSI/ASHRAE 16''), Method of
Testing for Rating Room Air Conditioners, Packaged Terminal Air
Conditioners, and Packaged Terminal Heat Pumps for Cooling and Heating
Capacity, ANSI-approved November 1, 2016; IBR approved for appendix C1
to subpart R.
(2) ANSI/ASHRAE Standard 23.1-2010 (``ASHRAE 23.1-2010''), Methods
of Testing for Rating the Performance of Positive Displacement
Refrigerant Compressors and Condensing Units that Operate at
Subcritical Temperatures of the Refrigerant, ANSI-approved January 28,
2010; IBR approved for appendices C and C1 to subpart R.
(3) ANSI/ASHRAE Standard 37-2009 (``ANSI/ASHRAE 37''), Methods of
Testing for Rating Electrically Driven Unitary Air-Conditioning and
Heat Pump Equipment, ASHRAE-approved June 24, 2009; IBR approved for
appendices C and C1 to subpart R.
(4) ANSI/ASHRAE Standard 41.1-2013 (``ANSI/ASHRAE 41.1''), Standard
Method for Temperature Measurement, ANSI-approved January 30, 2013; IBR
approved for appendix C1 to subpart R.
(5) ANSI/ASHRAE Standard 41.3-2014 (``ANSI/ASHRAE 41.3''), Standard
Methods for Pressure Measurement, ANSI-approved July 3, 2014; IBR
approved for appendix C1 to subpart R.
(6) ANSI/ASHRAE Standard 41.6-2014 (``ANSI/ASHRAE 41.6''), Standard
Method for Humidity Measurement, ANSI-approved July 3, 2014; IBR
approved for appendix C1 to subpart R.
(7) ANSI/ASHRAE Standard 41.10-2013 (``ANSI/ASHRAE 41.10''),
Standard Methods for Refrigerant Mass Flow Measurement Using
Flowmeters, ANSI-approved June 27, 2013; IBR approved for appendix C1
to subpart R.
(d) ASTM. ASTM, International, 100 Barr Harbor Drive, West
Conshohocken, PA 19428-2959; (610) 832-9500; www.astm.org.
(1) ASTM C518-17, Standard Test Method for Steady-State Thermal
Transmission Properties by Means of the Heat Flow Meter Apparatus,
approved May 1, 2017; IBR approved for appendix B to subpart R.
(2) ASTM C1199-14, Standard Test Method for Measuring the Steady-
State Thermal Transmittance of Fenestration Systems Using Hot Box
Methods, approved February 1, 2014; IBR approved for appendix A to
subpart R.
(e) NFRC. National Fenestration Rating Council, 6305 Ivy Lane, Ste.
140, Greenbelt, MD 20770; (301) 589-1776; www.nfrc.org/.
(1) NFRC 102-2020 [E0A0] (``NFRC 102-2020''), Procedure for
Measuring the Steady-State Thermal Transmittance of Fenestration
Systems, copyright 2013; IBR approved for appendix A to subpart R.
(2) [Reserved]
0
9. Amend Sec. 431.304 by revising paragraph (b) to read as follows:
Sec. 431.304 Uniform test method for the measurement of energy
consumption of walk-in coolers and walk-in freezers.
* * * * *
(b) Testing and calculations. Determine the energy efficiency and/
or energy consumption of the specified walk-in cooler and walk-in
freezer components by conducting the appropriate test procedure as
follows:
(1) Display panels. Determine the energy use of walk-in cooler and
walk-in freezer display panels by conducting the test procedure set
forth in appendix A to this subpart.
(2) Display doors and non-display doors. Determine the energy use
of walk-in cooler and walk-in freezer display doors and non-display
doors by conducting the test procedure set forth in appendix A to this
subpart.
(3) Non-display panels and non-display doors. Determine the R-value
of insulation of walk-in cooler and walk-in freezer non-display panels
and non-display doors by conducting the test procedure set forth in
appendix B to this subpart.
(4) Refrigeration systems. Determine the AWEF and net capacity of
walk-in cooler and walk-in freezer refrigeration systems by conducting
the test procedures set forth in appendix C or C1 to this subpart, as
applicable. Refer to the notes at the beginning of those appendices to
determine the applicable appendix to use for testing.
(i) For unit coolers: follow the general testing provisions in
sections 3.1 and 3.2, and the equipment-specific provisions in section
3.3 of appendix C or sections 4.5 through 4.8 of appendix C1.
(ii) For dedicated condensing units: follow the general testing
provisions in sections 3.1 and 3.2, and the product-specific provisions
in section 3.4 of appendix C or sections 4.5 through 4.8 of appendix
C1.
(iii) For single-packaged dedicated systems: follow the general
testing provisions in sections 3.1 and 3.2, and the product-specific
provisions in section 3.3 of appendix C or sections 4.5 through 4.8 of
appendix C1.
0
10. Revise appendix A to subpart R of part 431 to read as follows:
Appendix A to Subpart R of Part 431--Uniform Test Method for the
Measurement of Energy Consumption of the Components of Envelopes of
Walk-In Coolers and Walk-In Freezers
Note: Prior to October 31, 2023, representations with respect to
the energy use of envelope components of walk-in coolers and walk-in
freezers, including compliance certifications, must be based on
testing conducted in accordance with the applicable provisions of 10
CFR part 431, subpart R, appendix A, revised as of January 1, 2022.
Beginning October 31, 2023, representations with respect to energy
use of envelope components of walk-in coolers and walk-in freezers,
including compliance certifications, must be based on testing
conducted in accordance with this appendix.
0. Incorporation by Reference
DOE incorporated by reference in Sec. 431.303 the entire
standard for ASTM C1199-14 and NFRC 102-2020. However, certain
enumerated provisions of these standards, as set forth in sections
0.1 and 0.2 of this appendix are inapplicable. To the extent that
there is a conflict between the terms or provisions of a referenced
industry standard and the CFR, the CFR provisions control.
0.1 ASTM C1199-14
(a) Section 1 Scope, is inapplicable,
(b) Section 4 Significance and Use is inapplicable,
(c) Section 7.3 Test Conditions, is inapplicable,
(d) Section 10 Report, is inapplicable, and
(e) Section 11 Precision and Bias, is inapplicable.
0.2 NFRC 102-2020
(a) Section 1 Scope, is inapplicable,
(b) Section 4 Significance and Use, is inapplicable,
(c) Section 7.3 Test Conditions, is inapplicable,
(d) Section 10 Report, is inapplicable,
(e) Section 11 Precision and Bias, is inapplicable,
(f) Annex A3 Standard Test Method for Determining the Thermal
Transmittance of Tubular Daylighting Devices, is inapplicable, and
(g) Annex A5 Tables and Figures, is inapplicable.
1. General. The following sections of this appendix provide
additional instructions for testing. In cases where there is a
conflict, the language of this appendix takes highest precedence,
followed by NFRC 102-2020, followed by ASTM C1199-14. Any subsequent
amendment to a referenced
[[Page 28840]]
document by the standard-setting organization will not affect the
test procedure in this appendix, unless and until the test procedure
is amended by DOE. Material is incorporated as it exists on the date
of the approval, and a notification of any change in the
incorporation will be published in the Federal Register.
2. Scope
This appendix covers the test requirements used to measure the
energy consumption of the components that make up the envelope of a
walk-in cooler or walk-in freezer.
3. Definitions
The definitions contained in Sec. 431.302 are applicable to
this appendix.
4. Additional Definitions
4.1 Automatic door opener/closer means a device or control
system that ``automatically'' opens and closes doors without direct
user contact, such as a motion sensor that senses when a forklift is
approaching the entrance to a door and opens it, and then closes the
door after the forklift has passed.
4.2 Percent time off (PTO) means the percent of time that an
electrical device is assumed to be off.4.3 Rated power means the
input power of an electricity-consuming device as specified on the
device's nameplate. If the device does not have a nameplate or such
nameplate does not list the device's input power, then the rated
power must be determined from the device's product data sheet,
literature, or installation instructions that come with the device
or are available online.
4.4 Rating conditions means, unless explicitly stated otherwise,
all conditions shown in table A.1 of this appendix.
Table A.1--Temperature Conditions
------------------------------------------------------------------------
------------------------------------------------------------------------
Internal Temperatures (cooled space within the envelope)
------------------------------------------------------------------------
Cooler Dry-Bulb Temperature................................ 35 [deg]F
Freezer Dry-Bulb Temperature............................... -10 [deg]F
------------------------------------------------------------------------
External Temperatures (space external to the envelope)
------------------------------------------------------------------------
Freezer and Cooler Dry-Bulb Temperatures................... 75 [deg]F
------------------------------------------------------------------------
5. Test Methods and Measurements
5.1 U-Factor Test of Doors and Display Panels
Determine the U-factor of the entire door or display panel,
including the frame, in accordance with the specified sections of
NFRC 102-2020 and ASTM C1199-14 at the temperature conditions listed
in table A.1 of this appendix.
5.2 Required Test Measurements
2.1 For display doors and display panels, thermal transmittance,
Udd or Udp, respectively, shall be the
standardized thermal transmittance, UST, determined per
section 5.1.1 of this appendix.
5.2.2 For non-display doors, thermal transmittance,
Und, shall be the standardized thermal transmittance,
UST, determined per section 5.1 of this appendix.
5.2.3 Projected area of the test specimen, As, in ft\2\, as
referenced in ASTM C1199-14.
6. Calculations
6.1 Display Panels
6.1.1 Determine the U-factor of the display panel in accordance
with section 5.1 of this appendix, in units of Btu/(h-ft\2\-[deg]F).
6.1.2 Calculate the temperature differential,
[Delta]Tdp, [deg]F, for the display panel, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.004
Where:
TDB,ext,dp = dry-bulb air external temperature, [deg]F,
as prescribed in table A.1 of this appendix; and
TDB,int,dp = dry-bulb air temperature internal to the
cooler or freezer, [deg]F, as prescribed in table A.1 of this
appendix.
6.1.3 Calculate the conduction load through the display panel,
Qcond-dp, Btu/h, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.005
Where:
As = projected area of the test specimen (same as the
test specimen aperture in the surround panel) or the area used to
determine the U-factor in section 5.1 of this appendix, ft\2\;
[Delta]Tdp = temperature differential between
refrigerated and adjacent zones, [deg]F; and
Udp = thermal transmittance, U-factor, of the display
panel in accordance with section 5.1 of this appendix, Btu/(h-ft\2\-
[deg]F).
6.1.4 Calculate the total daily energy consumption,
Edp, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.006
Where:
Qcond,dp = the conduction load through the display panel,
Btu/h; and
EER = Energy Efficiency Ratio of walk-in (cooler or freezer), Btu/W-
h. For coolers, use EER = 12.4 Btu/W-h. For freezers, use EER = 6.3
Btu/W-h.
6.2 Display Doors
6.2.1 Conduction Through Display Doors
6.2.1.1 Determine the U-factor of the display door in accordance
with section 5.1 of this appendix, in units of Btu/(h-ft\2\-[deg]F).
6.2.1.2 Calculate the temperature differential,
[Delta]Tdd, [deg]F, for the display door as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.007
Where:
TDB,ext,dd = dry-bulb air temperature external to the
display door, [deg]F, as prescribed in table A.1 of this appendix;
and
TDB,int,dd = dry-bulb air temperature internal to the
display door, [deg]F, as prescribed in table A.1 of this appendix.
6.2.1.3 Calculate the conduction load through the display doors,
Qcond,dd, Btu/h, as follows:
[[Page 28841]]
[GRAPHIC] [TIFF OMITTED] TR04MY23.008
Where:
As = projected area of the test specimen (same as the
test specimen aperture in the surround panel) or the area used to
determine the U-factor in section 5.1 of this appendix, ft\2\;
[Delta]Tdd = temperature differential between
refrigerated and adjacent zones, [deg]F; and
Udd = thermal transmittance, U-factor of the door, in
accordance with section 5.1 of this appendix, Btu/(h-ft\2\-[deg]F).
6.2.1.4 Calculate the total daily energy consumption due to
conduction thermal load, Edd,thermal, kWh/day, as
follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.009
Where:
Qcond,dd = the conduction load through the display door,
Btu/h; and
EER = EER of walk-in (cooler or freezer), Btu/W-h. For coolers, use
EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/(W-h).
6.2.2 Direct Energy Consumption of Electrical Component(s) of Display
Doors
Electrical components associated with display doors could
include but are not limited to: heater wire (for anti-sweat or anti-
freeze application); lights; door motors; control system units; and
sensors.
6.2.2.1 Select the required value for percent time off (PTO) for
each type of electricity-consuming device per table A.2 of this
appendix, PTOt (%).
Table A.2--Percent Time Off Values
----------------------------------------------------------------------------------------------------------------
Controls, timer, or other Percent time
Device Temperature condition auto-shut-off system off value (%)
----------------------------------------------------------------------------------------------------------------
Lights.................................. All....................... Without................... 25
With...................... 50
Anti-sweat heaters...................... All....................... Without................... 0
Coolers................... With...................... 75
Freezers.................. With...................... 50
Door motors............................. All....................... .......................... 97
All other electricity-consuming devices. All....................... Without................... 0
With...................... 25
----------------------------------------------------------------------------------------------------------------
6.2.2.2 Calculate the power usage for each type of electricity-
consuming device, Pdd,comp,u,t, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.010
Where:
u = the index for each of type of electricity-consuming device
located on either (1) the interior facing side of the display door
or within the inside portion of the display door, (2) the exterior
facing side of the display door, or (3) any combination of (1) and
(2). For purposes of this calculation, the interior index is
represented by u = int and the exterior index is represented by u =
ext. If the electrical component is both on the interior and
exterior side of the display door then use u = int. For anti-sweat
heaters sited anywhere in the display door, 75 percent of the total
power is be attributed to u = int and 25 percent of the total power
is attributed to u = ext;
t = index for each type of electricity-consuming device with
identical rated power;
Prated,u,t = rated input power of each component, of type
t, kW;
PTOu,t = percent time off, for device of type t, %; and
nu,t = number of devices at the rated input power of type
t, unitless. 6.2.2.3 Calculate the total electrical energy
consumption for interior and exterior power, Pdd,tot,int
(kWh/day) and Pdd,tot,ext (kWh/day), respectively, as
follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.011
[GRAPHIC] [TIFF OMITTED] TR04MY23.012
Where:
t = index for each type of electricity-consuming device with
identical rated input power;
Pdd,comp,int,t = the energy usage for an electricity-
consuming device sited on the interior facing side of or in the
display door, of type t, kWh/day; and
Pdd,comp,ext,t = the energy usage for an electricity-
consuming device sited on the external facing side of the display
door, of type t, kWh/day. 6.2.2.4 Calculate the total electrical
energy consumption, Pdd,tot, (kWh/day), as follows:
[[Page 28842]]
[GRAPHIC] [TIFF OMITTED] TR04MY23.013
Where:
Pdd,tot,int = the total interior electrical energy usage
for the display door, kWh/day; and
Pdd,tot,ext = the total exterior electrical energy usage
for the display door, kWh/day.
6.2.3 Total Indirect Electricity Consumption Due to Electrical Devices
Calculate the additional refrigeration energy consumption due to
thermal output from electrical components sited inside the display
door, Cdd,load, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.014
Where:
Pdd,tot,int = The total internal electrical energy
consumption due for the display door, kWh/day; and
EER = EER of walk-in cooler or walk-in freezer, Btu/W-h. For
coolers, use EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/
(W-h).
6.2.4 Total Display Door Energy Consumption
Calculate the total energy, Edd,tot, kWh/day,
[GRAPHIC] [TIFF OMITTED] TR04MY23.015
Where:
Edd,thermal = the total daily energy consumption due to
thermal load for the display door, kWh/day;
Pdd,tot = the total electrical load, kWh/day; and
Cdd,load = additional refrigeration load due to thermal
output from electrical components contained within the display door,
kWh/day.
6.3 Non-Display Doors
6.3.1 Conduction Through Non-Display Doors
6.3.1.1 Determine the U-factor of the non-display door in
accordance with section 5.1 of this appendix, in units of Btu/(h-
ft\2\-[deg]F).
6.3.1.2 Calculate the temperature differential of the non-
display door, [Delta]Tnd, [deg]F, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.016
Where:
TDB,ext,nd = dry-bulb air external temperature, [deg]F,
as prescribed by table A.1 of this appendix; and
TDB,int,nd = dry-bulb air internal temperature, [deg]F,
as prescribed by table A.1 of this appendix. If the component spans
both cooler and freezer spaces, the freezer temperature must be
used.
6.3.1.3 Calculate the conduction load through the non-display
door: Qcond,nd, Btu/h,
[GRAPHIC] [TIFF OMITTED] TR04MY23.017
Where:
As = projected area of the test specimen (same as the
test specimen aperture in the surround panel) or the area used to
determine the U-factor in section 5.1 of this appendix, ft\2\;
[Delta]Tnd = temperature differential across the non-
display door, [deg]F; and
Und = thermal transmittance, U-factor of the door, in
accordance with section 5.1 of this appendix, Btu/(h-ft\2\-[deg]F).
6.3.1.4 Calculate the total daily energy consumption due to
thermal load, End,thermal, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.018
Where:
Qcond,nd = the conduction load through the non-display
door, Btu/h; and
EER = EER of walk-in (cooler or freezer), Btu/W-h. For coolers, use
EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/(W-h).
6.3.2 Direct Energy Consumption of Electrical Components of Non-Display
Doors
Electrical components associated with non-display doors comprise
could include, but are not limited to: heater wire (for anti-sweat
or anti-freeze application), lights, door motors, control system
units, and sensors.
6.3.2.1 Select the required value for percent time off for each
type of electricity-consuming device per table A.2 of this appendix,
PTOt (%).
6.3.2.2 Calculate the power usage for each type of electricity-
consuming device, Pnd,comp,u,t, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.019
[[Page 28843]]
Where:
u = the index for each of type of electricity-consuming device
located on either (1) the interior facing side of the non-display
door or within the inside portion of the non-display door, (2) the
exterior facing side of the non-display door, or (3) any combination
of (1) and (2). For purposes of this calculation, the interior index
is represented by u = int and the exterior index is represented by u
= ext. If the electrical component is both on the interior and
exterior side of the non-display door then use u = int. For anti-
sweat heaters sited anywhere in the non-display door, 75 percent of
the total power is be attributed to u = int and 25 percent of the
total power is attributed to u = ext;
t = index for each type of electricity-consuming device with
identical rated input power;
Prated,u,t = rated input power of each component, of type
t, kW;
PTOu,t = percent time off, for device of type t, %; and
nu,t = number of devices at the rated input power of type
t, unitless.
6.3.2.3 Calculate the total electrical energy consumption for
interior and exterior power, Pnd,tot,int, kWh/day, and
Pnd,tot,ext, kWh/day, respectively, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.020
[GRAPHIC] [TIFF OMITTED] TR04MY23.021
Where:
t = index for each type of electricity-consuming device with
identical rated input power;
Pnd,comp,int,t = the energy usage for an electricity-
consuming device sited on the internal facing side or internal to
the non-display door, of type t, kWh/day; and
Pnd,comp,ext,t = the energy usage for an electricity-
consuming device sited on the external facing side of the non-
display door, of type t, kWh/day. For anti-sweat heaters,
6.3.2.4 Calculate the total electrical energy consumption,
Pnd,tot, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.022
Where:
Pnd,tot,int = the total interior electrical energy usage
for the non-display door, of type t, kWh/day; and
Pnd,tot,ext = the total exterior electrical energy usage
for the non-display door, of type t, kWh/day.
6.3.3 Total Indirect Electricity Consumption Due to Electrical Devices
Calculate the additional refrigeration energy consumption due to
thermal output from electrical components associated with the non-
display door, Cnd,load, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.023
Where:
Pnd,tot,int = the total interior electrical energy
consumption for the non-display door, kWh/day; and
EER = EER of walk-in cooler or freezer, Btu/W-h. For coolers, use
EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/(W-h).
6.3.4 Total Non-Display Door Energy Consumption
Calculate the total energy, End,tot, kWh/day, as
follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.024
Where:
End,thermal = the total daily energy consumption due to
thermal load for the non-display door, kWh/day;
Pnd,tot = the total electrical energy consumption, kWh/
day; and
Cnd,load = additional refrigeration load due to thermal
output from electrical components contained on the inside face of
the non-display door, kWh/day.
0
11. Revise appendix B to subpart R of part 431 to read as follows:
Appendix B to Subpart R of Part 431--Uniform Test Method for the
Measurement of R-Value of Insulation for Envelope Components of Walk-In
Coolers and Walk-In Freezers
Note: Prior to October 31, 2023, representations with respect
to the R-value for insulation of envelope components of walk-in
coolers and walk-in freezers, including compliance certifications,
must be based on testing conducted in accordance with the applicable
provisions of 10 CFR part 431, subpart R, appendix B, revised as of
January 1, 2022. Beginning October 31, 2023, representations with
respect to R-value for insulation of envelope components of walk-in
coolers and walk-in freezers, including compliance certifications,
must be based on testing conducted in accordance with this appendix.
0. Incorporation by Reference
DOE incorporated by reference in Sec. 431.303 the entire
standard for ASTM C518-17. However, certain enumerated provisions of
ASTM C518-17, as set forth in paragraph 0.1 of this appendix, are
inapplicable. To the extent there is a conflict between the terms or
provisions of a referenced industry standard and the CFR, the CFR
provisions control.
0.1 ASTM C518-17
(a) Section 1 Scope, is inapplicable,
(b) Section 4 Significance and Use, is inapplicable,
(c) Section 7.3 Specimen Conditioning, is inapplicable,
(d) Section 9 Report, is inapplicable,
(e) Section 10 Precision and Bias, is inapplicable,
(f) Section 11 Keywords, is inapplicable,
[[Page 28844]]
(g) Annex A2 Equipment Error Analysis, is inapplicable,
(h) Appendix X1 is inapplicable,
(i) Appendix X2 Response of Heat Flux Transducers, is
inapplicable, and
(j) Appendix X3 Proven Performance of a Heat Flow Apparatus, is
inapplicable.
0.2 [Reserved]
1. General
The following sections of this appendix provide additional
instructions for testing. In cases where there is a conflict, the
language of this appendix takes highest precedence, followed by ASTM
C518-17. Any subsequent amendment to a referenced document by the
standard-setting organization will not affect the test procedure in
this appendix, unless and until the test procedure is amended by
DOE. Material is incorporated as it exists on the date of the
approval, and a notification of any change in the incorporation will
be published in the Federal Register.
2. Scope
This appendix covers the test requirements used to measure the
R-value of non-display panels and non-display doors of a walk-in
cooler or walk-in freezer.
3. Definitions
The definitions contained in Sec. 431.302 apply to this
appendix.
4. Additional Definitions
4.1 Edge region means a region of the envelope component that is
wide enough to encompass any framing members. If the envelope
component contains framing members (e.g., a wood frame) then the
width of the edge region must be as wide as any framing member plus
an additional 2 in. 0.25 in.
5. Test Methods, Measurements, and Calculations
5.1 General. Foam shall be tested after it is produced in its
final chemical form. For foam produced inside of an envelope
component (``foam-in-place''), ``final chemical form'' means the
foam is cured as intended and ready for use as a finished envelope
component. For foam produced as board stock (e.g., polystyrene),
``final chemical form'' means after extrusion and ready for assembly
into an envelope component or after assembly into an envelope
component. Foam must not include any structural members or non-foam
materials during testing in accordance with ASTM C518-17. When
preparing the specimen for test, a high-speed bandsaw or a meat
slicer are two types of recommended cutting tools. Hot wire cutters
or other heated tools shall not be used for cutting foam test
specimens.
5.2 Specimen Preparation
5.2.1 Determining the thickness around the perimeter of the
envelope component, tp. The full thickness of an envelope component
around the perimeter, which may include facers on one or both sides,
shall be determined as follows:
5.2.1.1 At least 8 thickness measurements shall be taken around
the perimeter of the envelope component, at least 2 inches from the
edge region, and avoiding any regions with hardware or fixtures.
5.2.1.2 The average of the thickness measurements taken around
the perimeter of the envelope component shall be the thickness
around the perimeter of the envelope component, tp.
5.2.1.3 Measure and record the width, wp, and height, hp, of the
envelope component. The surface area of the envelope component, Ap,
shall be determined as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.025
Where:
wp = width of the envelope component, in.; and
hp = height of the envelope component, in.
5.2.2. Removing the sample from the envelope component.
5.2.2.1. Determine the center of the envelope component relative
to its height and its width.
5.2.2.2. Cut a sample from the envelope component that is at
least the length and width dimensions of the heat flow meter, and
where the marked center of the sample is at least 3 inches from any
cut edge.
5.2.2.3. If the center of the envelope component contains any
non-foam components (excluding facers), additional samples may be
cut adjacent to the previous cut that is at least the length and
width dimensions of the heat flow meter and is greater than 12
inches from the edge region.
5.2.3. Determining the thickness at the center of the envelope
component, tc. The full thickness of an envelope component at the
center, which may include facers on one or both sides, shall be
determined as follows:
5.2.3.1. At least 2 thickness measurements shall be taken in
each quadrant of the cut sample removed from the envelope component
per section 5.2.2 of this appendix, for a total of at least 8
measurements.
5.2.3.2. The average of the thickness measurements of the cut
sample removed from the envelope component shall be the overall
thickness of the cut sample, tc.
5.2.3.3. Measure and record the width and height of the cut
sample removed from the envelope component. The surface area of the
cut sample removed from the envelope component, Ac., shall be
determined as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.026
Where:
wc = width of the cut sample removed from the envelope component,
in.; and
hc = height of the cut sample removed from the envelope component,
in.
5.2.4. Determining the total thickness of the foam within the
envelope component, tfoam. The average total thickness of the foam
sample, without facers, shall be determined as follows:
5.2.4.1. Remove the facers on the envelope component sample,
while minimally disturbing the foam.
5.2.4.2. Measure the thickness of each facer in 4 locations for
a total of 4 measurements if 1 facer is removed, and a total of 8
measurements if 2 facers are removed. The average of all facer
measurements shall be the thickness of the facers, tfacers, in.
5.2.4.3. The average total thickness of the foam, tfoam, in.,
shall be determined as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.027
Where:
tc = the average thickness of the center of the envelope component,
in., as determined per sections 5.2.3.1 and 5.2.3.2 of this
appendix;
Ac = the surface area of the center of the envelope component,
in\2\., as determined per section 5.2.3.3 of this appendix;
tp = the average thickness of the perimeter of the envelope
component, in., as determined per sections 5.2.1.1 and 5.2.1.2 of
this appendix;
Ap = the average thickness of the center of the envelope component,
in\2\, as determined per section 5.2.1.3 of this appendix;
tfacers = the average thickness of the facers of the envelope
component, in., as determined per section 5.2.4.2 of this appendix.
[[Page 28845]]
5.2.5. Cutting, measuring, and determining parallelism and
flatness of a 1-inch-thick specimen for test from the center of the
cut envelope component sample.
5.2.5.1. Cut a 1 0.1-inch-thick specimen from the
center of the cut envelope sample. The 1-inch-thick test specimen
shall be cut from the point that is equidistant from both edges of
the sample (i.e., shall be cut from the center point that would be
directly between the interior and exterior space of the walk-in).
5.2.5.2. Document through measurement or photographs with
measurement indicators that the specimen was taken from the center
of the sample.
5.2.5.3 After the 1-inch specimen has been cut, and prior to
testing, place the specimen on a flat surface and allow gravity to
determine the specimen's position on the surface. This will be side
1.
5.2.5.4 To determine the flatness of side 1, take at least nine
height measurements at equidistant positions on the specimen (i.e.,
the specimen would be divided into 9 regions and height measurements
taken at the center of each of these nine regions). Contact with the
measurement indicator shall not indent the foam surface. From the
height measurements taken, determine the least squares plane for
side 1. For each measurement location, calculate the theoretical
height from the least squares plane for side 1. Then, calculate the
difference between the measured height and the theoretical least
squares plane height at each location. The maximum difference minus
the minimum difference out of the nine measurement locations is the
flatness of side 1. For side 1 of the specimen to be considered
flat, this shall be less than or equal to 0.03 inches.
5.2.5.5 To determine the flatness of side 2, turn the specimen
over and allow gravity to determine the specimen's position on the
surface. Repeat section 5.2.5.4 to determine the flatness of side 2.
5.2.5.6 To determine the parallelism of the specimen for side 1,
calculate the theoretical height of the least squares plane at the
furthest corners (i.e., at points (0,0), (0,12), (12,0), and
(12,12)) of the 12-inch by 12-inch test specimen. The difference
between the maximum theoretical height and the minimum theoretical
height shall be less than or equal to 0.03 inches for each side in
order for side 1 to be considered parallel.
5.2.5.7 To determine the parallelism of the specimen for side 2,
repeat section
5.2.5.8 The average thickness of the test specimen, L, shall be
1 0.1-inches determined using a minimum of 18 thickness
measurements (i.e., a minimum of 9 measurements on side 1 of the
specimen and a minimum of 9 on side 2 of the specimen). This average
thickness shall be used to determine the thermal conductivity, or K-
factor.
5.3 K-factor Test. Determine the thermal conductivity, or K-
factor, of the 1-inch-thick specimen in accordance with the
specified sections of ASTM C518-17.
5.3.1 Test Conditions.
5.3.1.1 For freezer envelope components, the K-factor of the
specimen shall be determined at an average specimen temperature of
20 1 degrees Fahrenheit.
5.3.1.2 For cooler envelope components, the K-factor of the
specimen shall be determined at an average specimen temperature of
55 1 degrees Fahrenheit.
5.4 R-value Calculation.
5.4.1 For envelope components consisting of one homogeneous
layer of insulation, calculate the R-value, h-ft\2\-[deg]F/Btu, as
follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.028
Where:
tfoam = the total thickness of the foam, in., as determined in
section 5.2.4 of this appendix; and
[lgr] = K-factor, Btu-in/(h-ft\2\-[deg]F), as determined in section
5.3 of this appendix.
5.4.2 For envelope components consisting of two or more layers
of dissimilar insulating materials (excluding facers or protective
skins), determine the K-factor of each material as described in
sections 5.1 through 5.3 of this appendix. For an envelope component
with N layers of insulating material, the overall R-value shall be
calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.029
Where:
ti is the thickness of the ith material that appears in the envelope
component, inches, as determined in section 5.2.4 of this appendix;
[lgr]i is the k-factor of the ith material, Btu-in/(h-
ft\2\-[deg]F), as determined in section 5.3 of this appendix; and
N is the total number of material layers that appears in the
envelope component.
5.4.3 K-factor test results from a test sample 1
0.1-inches in thickness may be used to determine the R-value of
envelope components with various foam thicknesses as long as the
foam throughout the panel depth is of the same final chemical form
and the test was completed at the same test conditions that the
other envelope components would be used at. For example, a K-factor
test result conducted at cooler conditions cannot be used to
determine R-value of a freezer envelope component.
0
12. Amend appendix C to subpart R of part 431 by:
0
a. Adding an introductory note;
0
b. Revising sections 2.0 and 3.1.1;
0
c. Adding sections 3.1.6 and 3.1.7;
0
d. Revising sections 3.2.1 and 3.2.3;
0
e. Adding sections 3.2.6, 3.2.6.1, 3.2.6.1.1, 3.2.6.1.2, 3.2.6.2,
3.2.6.3, 3.2.6.4, 3.2.7, 3.2.7.1, 3.2.7.2, and 3.2.8;
0
f. Revising sections 3.3.1 and 3.3.3;
0
g. Adding sections 3.3.3.1, 3.3.3.2, 3.3.3.3, 3.3.3.3.1, and 3.3.3.3.2;
0
h. Revising sections 3.3.7, 3.3.7.1, and 3.3.7.2;
0
i. Adding sections 3.3.7.3, 3.3.7.3.1, and 3.3.7.3.2; and
0
j. Revising section 3.4.2.1.
The additions and revisions read as follows:
Appendix C to Subpart R of Part 431--Uniform Test Method for the
Measurement of Net Capacity and AWEF of Walk-In Cooler and Walk-In
Freezer Refrigeration Systems
Note: Prior to October 31, 2023, representations with respect to
the energy use of refrigeration components of walk-in coolers and
walk-in freezers, including compliance certifications, must be based
on testing conducted in accordance with the applicable provisions of
10 CFR part 431, subpart R, appendix C, revised as of January 1,
2022. Beginning October 31, 2023, representations with respect to
energy use of refrigeration components of walk-in coolers and walk-
in freezers, including compliance certifications, must be based on
testing conducted in accordance with this appendix.
For any amended standards for walk-in coolers and freezers
published after January 1, 2022, manufacturers must use the results
of testing under appendix C1 to this subpart to determine
compliance. Representations related to energy consumption must be
made in accordance with appendix C1 when determining compliance with
the relevant standard. Manufacturers may also use appendix C1 to
certify compliance with any amended standards prior to the
applicable compliance date for those standards.
* * * * *
2.0 Definitions
The definitions contained in Sec. 431.302 and AHRI 1250-2009
(incorporated by reference; see Sec. 431.303) apply to this
appendix. When definitions contained in the standards DOE has
incorporated by reference are in conflict or when they conflict with
this section, the
[[Page 28846]]
hierarchy of precedence shall be in the following order: Sec.
431.302, AHRI 1250-2009, and then either AHRI 420-2008 (incorporated
by reference; see Sec. 431.303) for unit coolers or ASHRAE 23.1-
2010 (incorporated by reference; see Sec. 431.303) for dedicated
condensing units.
The term ``unit cooler'' used in AHRI 1250-2009, AHRI 420-2008,
and this subpart shall be considered to address both ``unit
coolers'' and ``ducted fan coil units,'' as appropriate.
3.0 * * *
3.1. * * *
3.1.1. In Table 1, Instrumentation Accuracy, refrigerant
temperature measurements shall have an accuracy of +/-0.5 [deg]F for
unit cooler in/out. When testing high-temperature refrigeration
systems, measurements used to determine temperature or water vapor
content of the air (i.e., wet-bulb or dew point) shall be accurate
to within +/-0.25 [deg]F; all other temperature measurements shall
be accurate to within +/-1.0 [deg]F.
* * * * *
3.1.6. Test Operating Conditions for CO2 Unit Coolers
For medium-temperature CO2 unit coolers, conduct
tests using the test conditions specified in table 17 of this
appendix. For low-temperature CO2 unit coolers, conduct
tests using the test conditions specified in table 18 of this
appendix.
Table 17--Test Operating Conditions for Medium-Temperature CO2 Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit
Unit cooler
cooler air Suction Liquid inlet Liquid
Test description air entering dew point bubble point inlet Compressor capacity Test objective
entering relative temp, temperature subcooling,
dry-bulb, humidity, [deg]F [deg]F [deg]F
[deg]F %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power..................... 35 <50 .......... ............ ............ Compressor On.............. Measure fan input
power during
compressor off-cycle.
Refrigeration Capacity, Ambient 35 <50 25 38 5 Compressor Off............. Determine Net
Condition A. Refrigeration
Capacity of Unit
Cooler.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
Table 18--Test Operating Conditions for Low-Temperature CO2 Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit
Unit cooler
cooler air Suction Liquid inlet Liquid
Test description air entering dew point bubble point inlet Compressor capacity Test objective
entering relative temp, temperature subcooling,
dry-bulb, humidity, [deg]F [deg]F [deg]F
[deg]F %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power..................... -10 <50 .......... ............ ............ Compressor Off............. Measure fan input
power during
compressor off cycle.
Refrigeration Capacity, Ambient -10 <50 -20 38 5 Compressor On.............. Determine Net
Condition A. Refrigeration
Capacity of Unit
Cooler.
Defrost............................. -10 <50 .......... ............ ............ Compressor Off............. Test according to
Appendix C Section
C11 of AHRI 1250-
2009.
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
3.1.7. Test Operating Conditions for High-Temperature Unit Coolers
For high-temperature cooler unit coolers, conduct tests using
the test conditions specified in table 19 of this appendix.
Table 19--Test Operating Conditions for High-Temperature Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit
Unit cooler Suction
cooler air dew point Liquid inlet Liquid
Test description air entering temp, bubble point inlet Compressor capacity Test objective
entering relative [deg]F \2\ temperature subcooling,
dry-bulb, humidity, \3\ [deg]F [deg]F
[deg]F % \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle........................... 55 55 .......... 105 9 Compressor Off............. Measure fan input
power.
Refrigeration Capacity Suction A.... 55 55 38 105 9 Compressor On.............. Determine Net
Refrigeration
Capacity of Unit
Cooler.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative
humidity is 3%.
\2\ Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
\3\ Suction Dew Point shall be measured at the Unit Cooler Exit.
3.2. * * *
3.2.1. Refrigerant Temperature Measurements
In AHRI 1250-2009 appendix C, section C3.1.6, any refrigerant
temperature measurements entering and leaving the unit cooler may
use sheathed sensors immersed in the flowing refrigerant instead of
thermometer wells. When testing a condensing unit alone, measure
refrigerant liquid temperature leaving the condensing unit using
thermometer wells as described in AHRI 1250-2009 appendix C, section
C3.1.6 or sheathed sensors immersed in the flowing refrigerant. For
all of these cases, if the refrigerant tube outer diameter is less
than \1/2\ inch, the refrigerant temperature may be measured using
the average of two
[[Page 28847]]
temperature measuring instruments with a minimum accuracy of 0.5 [deg]F placed on opposite sides of the refrigerant tube
surface--resulting in a total of up to 8 temperature measurement
devices used for the DX Dual Instrumentation method. In this case,
the refrigerant tube shall be insulated with 1-inch thick insulation
from a point 6 inches upstream of the measurement location to a
point 6 inches downstream of the measurement location. Also, to
comply with this requirement, the unit cooler entering measurement
location may be moved to a location 6 inches upstream of the
expansion device and, when testing a condensing unit alone, the
entering and leaving measurement locations may be moved to locations
6 inches from the respective service valves.
* * * * *
3.2.3. Subcooling at Refrigerant Mass Flow Meter
In appendix C, section C3.4.5 of AHRI 1250-2009 (incorporated by
reference; see Sec. 431.303), and in section 7.1.2 of ASHRAE 23.1-
2010 (incorporated by reference; see Sec. 431.303) when verifying
subcooling at the mass flow meters, only the sight glass and a
temperature sensor located on the tube surface under the insulation
are required. Subcooling shall be verified to be within the 3 [deg]F
requirement downstream of flow meters located in the same chamber as
a condensing unit under test and upstream of flow meters located in
the same chamber as a unit cooler under test, rather than always
downstream as indicated in AHRI 1250-2009, section C3.4.5 or always
upstream as indicated in section 7.1.2 of ASHRAE 23.1-2010. If the
subcooling is less than 3 [deg]F, cool the line between the
condensing unit outlet and this location to achieve the required
subcooling. When providing such cooling while testing a matched
pair, (a) set up the line-cooling system and also set up apparatus
to heat the liquid line between the mass flow meters and the unit
cooler, (b) when the system has achieved steady state without
activation of the heating and cooling systems, measure the liquid
temperature entering the expansion valve for a period of at least 30
minutes, (c) activate the cooling system to provide the required
subcooling at the mass flow meters, (d) if necessary, apply heat
such that the temperature entering the expansion valve is within 0.5
\0\F of the temperature measured during step (b), and (e) proceed
with measurements once condition (d) has been verified.
* * * * *
3.2.6. Installation Instructions
Manufacturer installation instructions refer to the instructions
that are applied to the unit (i.e., as a label) or that come
packaged with the unit. Online installation instructions are
acceptable only if the version number or date of publication is
referenced on the unit label or in the documents that are packaged
with the unit.
3.2.6.1 Installation Instruction Hierarchy when available
installation instructions are in conflict
3.2.6.1.1 If a manufacturer installation instruction provided on
the label(s) applied to the unit conflicts with the manufacturer
installation instructions that are shipped with the unit, the
instructions on the unit's label take precedence.
3.2.6.1.2 Manufacturer installation instructions provided in any
documents that are packaged with the unit take precedence over any
manufacturer installation instructions provided online.
3.2.6.2 For testing of attached split systems, the manufacturer
installation instructions for the dedicated condensing unit shall
take precedence over the manufacturer installation instructions for
the unit cooler.
3.2.6.3 Unit setup shall be in accordance with the manufacturer
installation instructions (laboratory installation instructions
shall not be used).
3.2.6.4 Achieving test conditions shall always take precedence
over installation instructions.
3.2.7. Refrigerant Charging and Adjustment of Superheat and
Subcooling.
All dedicated condensing systems (dedicated condensing units
tested alone, matched pairs, and single packaged dedicated systems)
that use flooding of the condenser for head pressure control during
low-ambient-temperature conditions shall be charged, and superheat
and/or subcooling shall be set, at Refrigeration C test conditions
unless otherwise specified in the installation instructions.
If after being charged at Refrigeration C condition the unit
under test does not operate at the Refrigeration A condition due to
high pressure cut out, refrigerant shall be removed in increments of
4 ounces or 5 percent of the test unit's receiver capacity,
whichever quantity is larger, until the unit operates at the
Refrigeration A condition. All tests shall be run at this final
refrigerant charge. If less than 0 [deg]F of subcooling is measured
for the refrigerant leaving the condensing unit when testing at B or
C condition, calculate the refrigerant-enthalpy-based capacity
(i.e., when using the DX dual instrumentation, the DX calibrated
box, or single-packaged unit refrigerant enthalpy method) assuming
that the refrigerant is at saturated liquid conditions at the
condensing unit exit.
All dedicated condensing systems that do not use a flooded
condenser design shall be charged at Refrigeration A test conditions
unless otherwise specified in the installation instructions.
If the installation instructions give a specified range for
superheat, sub-cooling, or refrigerant pressure, the average of the
range shall be used as the refrigerant charging parameter target and
the test condition tolerance shall be 50 percent of the
range. Perform charging of near-azeotropic and zeotropic
refrigerants only with refrigerant in the liquid state. Once the
correct refrigerant charge is determined, all tests shall run until
completion without further modification.
3.2.7.1. When charging or adjusting superheat/subcooling, use
all pertinent instructions contained in the installation
instructions to achieve charging parameters within the tolerances.
However, in the event of conflicting charging information between
installation instructions, follow the installation instruction
hierarchy listed in section 3.2.6. of this appendix. Conflicting
information is defined as multiple conditions given for charge
adjustment where all conditions specified cannot be met. In the
event of conflicting information within the same set of charging
instructions (e.g., the installation instructions shipped with the
dedicated condensing unit), follow the hierarchy in table 1 of this
section for priority. Unless the installation instructions specify a
different charging tolerance, the tolerances identified in table 1
of this section shall be used.
Table 1--Test Condition Tolerances and Hierarchy for Refrigerant Charging and Setting of Refrigerant Conditions
----------------------------------------------------------------------------------------------------------------
Fixed orifice Expansion valve
-----------------------------------------------------------------------------------------------
Priority Parameter with Parameter with
installation Tolerance installation Tolerance
instruction target instruction target
----------------------------------------------------------------------------------------------------------------
1............... Superheat............. 2.0 [deg]F Subcooling............ 10% of the Target
Value; No less than
0.5
[deg]F, No more than
2.0
[deg]F.
2............... High Side Pressure or 4.0 psi or High Side Pressure or 4.0 psi or
Saturation 1.0 Saturation 1.0
Temperature. [deg]F. Temperature. [deg]F.
3............... Low Side Pressure or 2.0 psi or Superheat............. 2.0
Saturation 0.8 [deg]F.
Temperature. [deg]F.
4............... Low Side Temperature.. 2.0 [deg]F Low Side Pressure or 2.0 psi or
Saturation 0.8
Temperature. [deg]F.
5............... High Side Temperature. 2.0 [deg]F Approach Temperature.. 1.0
[deg]F.
[[Page 28848]]
6............... Charge Weight......... 2.0 oz.... Charge Weight......... 0.5% or 1.0 oz,
whichever is greater.
----------------------------------------------------------------------------------------------------------------
3.2.7.2. Dedicated Condensing Unit. If the Dedicated Condensing
Unit includes a receiver and the subcooling target leaving the
condensing unit provided in installation instructions cannot be met
without fully filling the receiver, the subcooling target shall be
ignored. Likewise, if the Dedicated Condensing unit does not include
a receiver and the subcooling target leaving the condensing unit
cannot be met without the unit cycling off on high pressure, the
subcooling target can be ignored. Also, if no instructions for
charging or for setting subcooling leaving the condensing unit are
provided in the installation instructions, the refrigeration system
shall be set up with a charge quantity and/or exit subcooling such
that the unit operates during testing without shutdown (e.g., on a
high-pressure switch) and operation of the unit is otherwise
consistent with the requirements of the test procedure of this
appendix and the installation instructions.
3.2.8. Chamber Conditioning using the Unit Under Test.
In appendix C, section C6.2 of AHRI 1250-2009, for applicable
system configurations (matched pairs, single-packaged refrigeration
systems, and standalone unit coolers), the unit under test may be
used to aid in achieving the required test chamber conditions prior
to beginning any steady state test. However, the unit under test
must be inspected and confirmed to be free from frost before
initiating steady state testing.
* * * * *
3.3. * * *
3.3.1. For unit coolers tested alone, use test procedures
described in AHRI 1250-2009 for testing unit coolers for use in mix-
match system ratings, except that for the test conditions in tables
15 and 16 of this appendix, use the Suction A saturation condition
test points only. Also, for unit coolers tested alone, other than
high-temperature unit coolers, use the calculations in section 7.9
of AHRI 1250-2009 to determine AWEF and net capacity described in
AHRI 1250-2009 for unit coolers matched to parallel rack systems.
* * * * *
3.3.3. Evaporator Fan Power.
3.3.3.1. Ducted Evaporator Air.
For ducted fan coil units with ducted evaporator air, or that
can be installed with or without ducted evaporator air: Connect
ductwork on both the inlet and outlet connections and determine
external static pressure as described in ASHRAE 37 (incorporated by
reference; see Sec. 431.303), sections 6.4 and 6.5. Use pressure
measurement instrumentation as described in ASHRAE 37, section
5.3.2. Test at the fan speed specified in manufacturer installation
instructions--if there is more than one fan speed setting and the
installation instructions do not specify which speed to use, test at
the highest speed. Conduct tests with the external static pressure
equal to 50 percent of the maximum external static pressure allowed
by the manufacturer for system installation within a tolerance of -
0.00/+0.05 in. wc. Set the external static pressure by symmetrically
restricting the outlet of the test duct. Alternatively, if using the
indoor air enthalpy method to measure capacity, set external static
pressure by adjusting the fan of the airflow measurement apparatus.
In case of conflict, these requirements for setting evaporator
airflow take precedence over airflow values specified in
manufacturer installation instructions or product literature.
3.3.3.2. Unit Coolers or Single-Packaged Systems that are not
High-Temperature Refrigeration Systems.
Use appendix C, section C10 of AHRI 1250-2009 for off-cycle
evaporator fan testing, with the exception that evaporator fan
controls using periodic stir cycles shall be adjusted so that the
greater of a 50 percent duty cycle (rather than a 25 percent duty
cycle) or the manufacturer default is used for measuring off-cycle
fan energy. For adjustable-speed controls, the greater of 50 percent
fan speed (rather than 25 percent fan speed) or the manufacturer's
default fan speed shall be used for measuring off-cycle fan energy.
Also, a two-speed or multi-speed fan control may be used as the
qualifying evaporator fan control. For such a control, a fan speed
no less than 50 percent of the speed used in the maximum capacity
tests shall be used for measuring off-cycle fan energy.
3.3.3.3. High-Temperature Refrigeration Systems.
3.3.3.3.1. The evaporator fan power consumption shall be
measured in accordance with the requirements in section C3.5 of AHRI
1250-2009. This measurement shall be made with the fan operating at
full speed, either measuring unit cooler or total system power input
upon the completion of the steady state test when the compressor and
the condenser fan of the walk-in system are turned off, or by
submetered measurement of the evaporator fan power during the steady
state test.
Section C3.5 of AHRI 1250-2009 is revised to read:
Evaporator Fan Power Measurement.
The following shall be measured and recorded during a fan power
test.
EFcomp,on Total electrical power input to fan motor(s) of
Unit Cooler, W
FS Fan speed(s), rpm
N Number of motors
Pb Barometric pressure, in. Hg
Tdb Dry-bulb temperature of air at inlet, [deg]F
Twb Wet-bulb temperature of air at inlet, [deg]F
V Voltage of each phase
For a given motor winding configuration, the total power input
shall be measured at the highest nameplate voltage. For three-phase
power, voltage imbalance shall be no more than 2%.
3.3.3.3.2. Evaporator fan power for the off-cycle is equal to
the on-cycle evaporator fan power with a run time of 10 percent of
the off-cycle time.
EFcomp,off = 0.1 x EFcomp,on
* * * * *
3.3.7. Calculations for Unit Coolers Tested Alone.
3.3.7.1. Unit Coolers that are not High-Temperature Unit
Coolers.
Calculate the AWEF and net capacity using the calculations in
AHRI 1250-2009, section 7.9.
3.3.7.2 High-Temperature Unit Coolers.
Calculate AWEF on the basis that walk-in box load is equal to
half of the system net capacity, without variation according to high
and low load periods, and with EER set according to tested
evaporator capacity, as follows:
The net capacity, qmix,evap, is determined from the test data
for the unit cooler at the 38 [deg]F suction dewpoint.
[[Page 28849]]
[GRAPHIC] [TIFF OMITTED] TR04MY23.030
Where:
[GRAPHIC] [TIFF OMITTED] TR04MY23.031
Where:
BL is the non-equipment-related box load;
LF is the load factor; and
Other symbols are as defined in section 8 of AHRI 1250-2009.
3.3.7.3. If the unit cooler has variable-speed evaporator fans
that vary fan speed in response to load, then:
3.3.7.3.1. When testing to certify compliance with the energy
conservation standards in Sec. 431.306, fans shall operate at full
speed during on-cycle operation. Do not conduct the calculations in
AHRI 1250-2009, section 7.9.3. Instead, use AHRI 1250-2009, section
7.9.2 to determine the system's AWEF.
3.3.7.3.2. When calculating the benefit for the inclusion of
variable-speed evaporator fans that modulate fan speed in response
to load for the purpose of making representations of efficiency, use
AHRI 1250-2009, section 7.9.3 to determine the system AWEF.
3.4. * * *
3.4.2. * * *
3.4.2.1. For calculating enthalpy leaving the unit cooler to
calculate gross capacity, (a) the saturated refrigerant temperature
(dew point) at the unit cooler coil exit, Tevap, shall be
25 [deg]F for medium-temperature systems (coolers) and -20 [deg]F
for low-temperature systems (freezers), and (b) the refrigerant
temperature at the unit cooler exit shall be 35 [deg]F for medium-
temperature systems (coolers) and -14 [deg]F for low-temperature
systems (freezers). For calculating gross capacity, the measured
enthalpy at the condensing unit exit shall be used as the enthalpy
entering the unit cooler. The temperature measurement requirements
of appendix C, section C3.1.6 of AHRI 1250-2009 and modified by
section 3.2.1 of this appendix shall apply only to the condensing
unit exit rather than to the unit cooler inlet and outlet, and they
shall be applied for two measurements when using the DX Dual
Instrumentation test method.
* * * * *
0
13. Add appendix C1 to subpart R of part 431 to read as follows:
Appendix C1 to Subpart R of Part 431--Uniform Test Method for the
Measurement of Net Capacity and AWEF2 of Walk-In Cooler and Walk-In
Freezer Refrigeration Systems
Note: Prior to October 31, 2023, representations with respect to
the energy use of refrigeration components of walk-in coolers and
walk-in freezers, including compliance certifications, must be based
on testing conducted in accordance with the applicable provisions
for 10 CFR part 431, subpart R, appendix C, revised as of January 1,
2022. Beginning October 31, 2023, representations with respect to
energy use of refrigeration components of walk-in coolers and walk-
in freezers, including compliance certifications, must be based on
testing conducted in accordance with appendix C to this subpart.
For any amended standards for walk-in coolers and walk-in
freezers published after January 1, 2022, manufacturers must use the
results of testing under this appendix to determine compliance.
Representations related to energy consumption must be made in
accordance with this appendix when determining compliance with the
relevant standard. Manufacturers may also use this appendix to
certify compliance with any amended standards prior to the
applicable compliance date for those standards.
0. Incorporation by Reference
DOE incorporated by reference in Sec. 431.303, the entire
standard for AHRI 1250-2020, ANSI/ASHRAE 16, ANSI/ASHRAE 23.1-2010,
ANSI/ASHRAE 37, ANSI/ASHRAE 41.1, ANSI/ASHRAE 41.3, ANSI/ASHRAE
41.6, and ANSI/ASHRAE 41.10. However, certain enumerated provisions
of these standards, as set forth in sections 0.1 through 0.8 of this
appendix are inapplicable. To the extent there is a conflict between
the terms or provisions of a referenced industry standard and the
CFR, the CFR provisions control. To the extent there is a conflict
between the terms or provisions of AHRI 1250-2020, ANSI/ASHRAE 16,
ANSI/ASHRAE 23.1-2010, ANSI/ASHRAE 37, ANSI/ASHRAE 41.1, ANSI/ASHRAE
41.3, ANSI/ASHRAE 41.6, and ANSI/ASHRAE 41.10, the AHRI 1250-2020
provisions control.
0.1 AHRI 1250-2020
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 9 Minimum Data Requirements for Published Rating, is
inapplicable
(d) Section 10 Marking and Nameplate Data, is inapplicable
[[Page 28850]]
(e) Section 11 Conformance Conditions, is inapplicable
0.2 ANSI/ASHRAE 16
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Normative Appendices E-M, are inapplicable
(e) Informative Appendices N-R, are inapplicable
0.3 ANSI/ASHRAE 23.1-2010
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
0.4 ANSI/ASHRAE 37
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Informative Appendix A Classifications of Unitary Air-
conditioners and Heat Pumps, is inapplicable.
0.5 ANSI/ASHRAE 41.1
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 9 Test Report, is inapplicable
(e) Informative Appendices A-C, are inapplicable
0.6 ANSI/ASHRAE 41.3
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 6 Instrument Types (informative), is inapplicable
(e) Section 8 Test Report, is inapplicable
(f) Informative Annexes A-D, are inapplicable
0.7 ANSI/ASHRAE 41.6
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 9 Test Report, is inapplicable
(e) Informative Appendices A-D, are inapplicable
0.8 ANSI/ASHRAE 41.10
(a) Section 1 Purpose, is inapplicable
(b) Section 2 Scope, is inapplicable
(c) Section 4 Classifications, is inapplicable
(d) Section 10 Test Report, is inapplicable
(e) Informative Annexes A-D, are inapplicable
1. Scope
This appendix covers the test requirements used to determine the
net capacity and the AWEF2 of the refrigeration system of a walk-in
cooler or walk-in freezer.
2. Definitions
2.1. Applicable Definitions
The definitions contained in Sec. 431.302, AHRI 1250-2020,
ANSI/ASHRAE 37, and ANSI/ASHRAE 16 apply to this appendix. When
definitions in standards incorporated by reference are in conflict
or when they conflict with this section, the hierarchy of precedence
shall be in the following order: Sec. 431.302, AHRI 1250-2020, and
then either ANSI/ASHRAE 37 or ANSI/ASHRAE 16.
The term ``unit cooler'' used in AHRI 1250-2020 and this subpart
shall be considered to address both ``unit coolers'' and ``ducted
fan coil units,'' as appropriate.
2.2. Additional Definitions
2.2.1. Digital Compressor means a compressor that uses
mechanical means for disengaging active compression on a cyclic
basis to provide a reduced average refrigerant flow rate in response
to a control system input signal.
2.2.2. Displacement Ratio, applicable to staged positive
displacement compressor systems, means the swept volume rate, e.g.
in cubic centimeters per second, of a given stage, divided by the
swept volume rate at full capacity.
2.2.3. Duty Cycle, applicable to digital compressors, means the
fraction of time that the compressor is engaged and actively
compressing refrigerant.
2.2.4. Maximum Speed, applicable to variable-speed compressors,
means the maximum speed at which the compressor will operate under
the control of the dedicated condensing system control system for
extended periods of time, i.e. not including short-duration boost-
mode operation.
2.2.5. Minimum Speed, applicable to variable-speed compressors,
means the minimum compressor speed at which the compressor will
operate under the control of the dedicated condensing system control
system.
2.2.6. Multiple-Capacity, applicable for describing a
refrigeration system, indicates that it has three or more stages
(levels) of capacity.
2.2.7. Speed Ratio, applicable to variable-speed compressors,
means the ratio of operating speed to the maximum speed.
3. Test Methods, Measurements, and Calculations
Determine the Annual Walk-in Energy Factor (AWEF2) and net
capacity of walk-in cooler and walk-in freezer refrigeration systems
by conducting the test procedure set forth in AHRI 1250-2020, with
the modifications to that test procedure provided in this section.
However, certain sections of AHRI 1250-2020, ANSI/ASHRAE 37, and
ANSI/ASHRAE 16 are not applicable, as set forth in sections 0.1,
0.2, and 0.3 of this appendix. Round AWEF2 measurements to the
nearest 0.01 Btu/Wh. Round net capacity measurements as indicated in
table 1 of this appendix.
Table 1--Rounding of Refrigeration System Net Capacity
------------------------------------------------------------------------
Rounding
Net capacity range, Btu/h multiple,
Btu/h
------------------------------------------------------------------------
<20,000...................................................... 100
>=20,000 and <38,000......................................... 200
>=38,000 and <65,000......................................... 500
>=65,000..................................................... 1,000
------------------------------------------------------------------------
The following sections of this appendix provide additional
instructions for testing. In cases where there is a conflict, the
language of this appendix takes highest precedence, followed by AHRI
1250-2020, then ANSI/ASHRAE 37 or ANSI/ASHRAE 16. Any subsequent
amendment to a referenced document by the standard-setting
organization will not affect the test procedure in this appendix,
unless and until the test procedure is amended by DOE. Material is
incorporated as it exists on the date of the approval, and a
notification of any change in the incorporation will be published in
the Federal Register.
3.1. Instrumentation Accuracy and Test Tolerances
Use measuring instruments as described in section 4.1 of AHRI
1250-2020, with the following additional requirement.
3.1.1. Electrical Energy Input measured in Wh with a minimum
accuracy of 0.5% of reading (for Off-Cycle tests per
footnote 5 of Table C3 in section C3.6.2 of AHRI 1250-2020).
3.2. Test Operating Conditions
Test conditions used to determine AWEF2 shall be as specified in
Tables 4 through 17 of AHRI 1250-2020. Tables 7 and 11 of AHRI 1250-
2020, labeled to apply to variable-speed outdoor matched-pair
refrigeration systems, shall also be used for testing variable-
capacity single-packaged outdoor refrigeration systems, and also for
testing multiple-capacity matched-pair or single-packaged outdoor
refrigeration systems. Test conditions used to determine AWEF2 for
refrigeration systems not specifically identified in AHRI 1250-2020
are as enumerated in sections 3.5.1 through 3.5.6 of this appendix.
3.2.1 Test Operating Conditions for High-Temperature Refrigeration
Systems
For fixed-capacity high-temperature matched-pair or single-
packaged refrigeration systems with indoor condensing units, conduct
tests using the test conditions specified in table 2 of this
appendix. For fixed-capacity high-temperature matched-pair or
single-packaged refrigeration systems with outdoor condensing units,
conduct tests using the test conditions specified in table 3 of this
appendix. For high-temperature unit coolers tested alone, conduct
tests using the test conditions specified in table 4 of this
appendix.
[[Page 28851]]
Table 2--Test Operating Conditions for Fixed-Capacity High-Temperature Indoor Matched Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler
Unit cooler air Condenser Condenser
air entering air air
Test description entering relative entering entering Compressor status Test objective
dry-bulb, humidity, % dry-bulb, wet-bulb,
[deg]F \1\ [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power......................... 55 55 ........... ........... Compressor Off................ Measure total input
wattage during compressor
off-cycle, (Ecu,off +
EFcomp,off).\2\
Refrigeration Capacity A................ 55 55 90 \3\ 75, \4\ Compressor On................. Determine Net
65 Refrigeration Capacity of
Unit Cooler, input power,
and EER at Test
Condition.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative
humidity is 3%.
\2\ Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250-2020.
\3\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\4\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
Table 3--Test Operating Conditions for Fixed-Capacity High-Temperature Outdoor Matched-Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler
Unit cooler air Condenser Condenser
air entering air air
Test description entering relative entering entering Compressor status Test objective
dry-bulb, humidity, % dry-bulb, wet-bulb,
[deg]F \1\ [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Refrigeration Capacity A................ 55 55 95 \3\ 75, \4\ Compressor On................. Determine Net
68 Refrigeration Capacity of
Unit Cooler, input power,
and EER at Test
Condition.
Off-Cycle Power, Capacity A \5\......... 55 55 95 \3\ 75, \4\ Compressor Off................ Measure total input
68 wattage during compressor
off-cycle, (Ecu,off +
EFcomp,off).\2\
Refrigeration Capacity B................ 55 55 59 \3\ 54, \4\ Compressor On................. Determine Net
46 Refrigeration Capacity of
Unit Cooler and system
input power at moderate
condition.
Off-Cycle Power, Capacity B \5\......... 55 55 59 \3\ 54, \4\ Compressor Off................ Measure total input
46 wattage during compressor
off-cycle, (Ecu,off +
EFcomp,off).\2\
Refrigeration Capacity C................ 55 55 35 \3\ 34, \4\ Compressor On................. Determine Net
29 Refrigeration Capacity of
Unit Cooler and system
input power at cold
condition.
Off-Cycle Power, Capacity C \5\......... 55 55 35 \3\ 34, \4\ Compressor Off................ Measure total input
29 wattage during compressor
off-cycle, (Ecu,off +
EFcomp,off).\2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative
humidity is 3%.
\2\ Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250-2020.
\3\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\4\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
Table 4--Test Operating Conditions for High-Temperature Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler
Unit cooler air Suction dew Liquid inlet Liquid
air entering point temp, bubble point inlet
Test description entering relative [deg]F \3\ temperature, subcooling, Compressor status Test objective
dry-bulb, humidity, % \4\ [deg]F [deg]F
[deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle......................... 55 55 ........... 105 9 Compressor Off........... Measure unit cooler
input wattage during
compressor off-
cycle, EF.\2\
Refrigeration Capacity............ 55 55 38 105 9 Compressor On............ Determine Net
Refrigeration
Capacity of Unit
Cooler, input power,
and EER at Test
Condition.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative
humidity is 3%.
\2\ Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250-2020.
\3\ Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
\4\ Suction Dew Point shall be measured at the Unit Cooler Exit.
3.2.2 Test Operating Conditions for CO2 Unit Coolers
For medium-temperature CO2 Unit Coolers, conduct
tests using the test conditions specified in table 5 of this
appendix. For low-temperature CO2 Unit Coolers, conduct
tests using the test conditions specified in table 6 of this
appendix.
Table 5--Test Operating Conditions for Medium-Temperature CO2 Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air air Suction dew Liquid inlet Liquid
Test title entering entering point bubble point inlet Compressor operating mode Test objective
dry-bulb, relative temp,\3\ temperature, subcooling,
[deg]F humidity, % [deg]F [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power................... 35 <50 ........... .............. ........... Compressor On............ Measure unit cooler
input wattage during
compressor off-
cycle, EF.\2\
[[Page 28852]]
Refrigeration Capacity, Ambient 35 <50 25 38 5 Compressor Off........... Determine Net
Condition A. Refrigeration
Capacity of Unit
Cooler, q.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
\2\ Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250-2020.
\3\ Suction Dew Point shall be measured at the Unit Cooler Exit conditions.
Table 6--Test Operating Conditions for Low-Temperature CO2 Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air air Suction dew Liquid inlet Liquid
Test title entering entering point bubble point inlet Compressor operating mode Test objective
dry-bulb, relative temp,\2\ temperature, subcooling,
[deg]F humidity, % [deg]F [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power................... -10 <50 ........... .............. ........... Compressor Off........... Measure unit cooler
input wattage during
compressor off-
cycle, EF.\2\
Refrigeration Capacity, Ambient -10 <50 -20 38 5 Compressor On............ Determine Net
Condition A. Refrigeration
Capacity of Unit
Cooler, q.
Defrost........................... -10 <50 ........... .............. ........... Compressor Off........... Test according to
Appendix C Section
C10 of AHRI 1250-
2020, DF,Q.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
\2\ Measure off-cycle power as described in sections C3 and C4.2 of AHRI 1250-2020.
\3\ Suction Dew Point shall be measured at the Unit Cooler Exit conditions.
3.2.3 Test Operating Conditions for Two-Capacity Condensing Units
Tested Alone
For two-capacity medium-temperature outdoor condensing units
tested alone, conduct tests using the test conditions specified in
table 7 of this appendix. For two-capacity medium-temperature indoor
condensing units tested alone, conduct tests using the test
conditions specified in table 8 of this appendix. For two-capacity
low-temperature outdoor condensing units tested alone, conduct tests
using the test conditions specified in table 9 of this appendix. For
two-capacity low-temperature indoor condensing units tested alone,
conduct tests using the test conditions specified in table 10 of
this appendix.
Table 7--Test Operating Conditions for Two-Capacity Medium-Temperature Outdoor Dedicated Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test description point, [deg]F [deg]F entering dry- bulb, [deg]F status
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low 24 41 95 75 Low Capacity,
Capacity. k=1.
Capacity, Condition A, High 23 41 95 75 High Capacity,
Capacity. k=2.
Off-Cycle, Condition A........ .............. .............. 95 75 Off.
Capacity, Condition B, Low 24 41 59 54 Low Capacity,
Capacity. k=1.
Capacity, Condition B, High 23 .............. 59 54 High Capacity,
Capacity. k=2.
Off-Cycle, Condition B........ .............. .............. 59 54 Off.
Capacity, Condition C, Low 24 41 35 34 Low Capacity,
Capacity. k=1.
Capacity, Condition C, High 23 41 35 34 High Capacity,
Capacity. k=2.
Off-Cycle, Condition C........ .............. .............. 35 34 Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
Table 8--Test Operating Conditions for Two-Capacity Medium-Temperature Indoor Dedicated Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test description point, [deg]F [deg]F entering dry- bulb, [deg]F status
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low 24 41 90 75 Low Capacity,
Capacity. k=1.
Capacity, Condition A, High 23 41 90 75 High Capacity,
Capacity. k=2.
Off-Cycle, Condition A........ .............. .............. 90 75 Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
[[Page 28853]]
Table 9--Test Operating Conditions for Two-Capacity Low-Temperature Outdoor Dedicated Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test title point, [deg]F [deg]F entering dry- bulb, [deg]F operating mode
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low -22 5 95 75 Low Capacity,
Capacity. k=1.
Capacity, Condition A, High -22 5 95 75 High Capacity,
Capacity. k=2.
Off-Cycle, Condition A........ .............. .............. 95 75 Compressor Off.
Capacity, Condition B, Low -22 5 59 54 Low Capacity,
Capacity. k=1.
Capacity, Condition B, High -22 5 59 54 High Capacity,
Capacity. k=2.
Off-Cycle, Condition B........ .............. .............. 59 54 Compressor Off.
Capacity, Condition C, Low -22 5 35 34 Low Capacity,
Capacity. k=1.
Capacity, Condition C, High -22 5 35 34 Maximum
Capacity. Capacity, k=2.
Off-Cycle, Condition C........ .............. .............. 35 34 Compressor Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
Table 10--Test Operating Conditions for Two-Capacity Low-Temperature Indoor Dedicated Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test title point, [deg]F [deg]F entering dry- bulb, [deg]F operating mode
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low -22 5 90 75 Low Capacity,
Capacity. k=1.
Capacity, Condition A, High -22 5 90 75 High Capacity,
Capacity. k=2.
Off-Cycle, Condition A........ .............. .............. 90 75 Compressor Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
3.2.4 Test Operating Conditions for Variable- or Multiple-Capacity
Condensing Units Tested Alone
For variable-capacity or multiple-capacity outdoor medium-
temperature condensing units tested alone, conduct tests using the
test conditions specified in table 11 of this appendix. For
variable-capacity or multiple-capacity indoor medium-temperature
condensing units tested alone, conduct tests using the test
conditions specified in table 12 of this appendix. For variable-
capacity or multiple-capacity outdoor low-temperature condensing
units tested alone, conduct tests using the test conditions
specified in table 13 of this appendix. For variable-capacity or
multiple-capacity indoor low-temperature condensing units tested
alone, conduct tests using the test conditions specified in table 14
of this appendix.
Table 11--Test Operating Conditions for Variable- or Multiple-Capacity Medium-Temperature Outdoor Dedicated
Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test description point, [deg]F [deg]F entering dry- bulb, [deg]F status
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum 24 41 95 75 Minimum
Capacity. Capacity, k=1.
Capacity, Condition A, 24 41 95 75 Intermediate
Intermediate Capacity. Capacity, k=i.
Capacity, Condition A, Maximum 23 41 95 75 Maximum
Capacity. Capacity, k=2
Off-Cycle, Condition A........ .............. .............. 95 75 Off.
Capacity, Condition B, Minimum 24 41 59 54 Minimum
Capacity. Capacity, k=1.
Capacity, Condition B, 24 41 59 54 Intermediate
Intermediate Capacity. Capacity, k=i.
Capacity, Condition B, Maximum 23 41 59 54 Maximum
Capacity. Capacity, k=2.
Off-Cycle, Condition B........ .............. .............. 59 54 Off.
Capacity, Condition C, Minimum 24 41 35 34 Minimum
Capacity. Capacity, k=1.
Capacity, Condition C, 24 41 35 34 Intermediate
Intermediate Capacity. Capacity, k=i.
Capacity, Condition C, Maximum 23 41 35 34 Maximum
Capacity. Capacity, k=2.
Off-Cycle, Condition C........ .............. .............. 35 34 Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
[[Page 28854]]
Table 12--Test Operating Conditions for Variable- or Multiple-Capacity Medium-Temperature Indoor Dedicated
Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test description point, [deg]F [deg]F entering dry- bulb, [deg]F status
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum 24 41 90 75 Minimum
Capacity. Capacity, k=1.
Capacity, Condition A, 24 41 90 75 Intermediate
Intermediate Capacity. Capacity, k=i.
Capacity, Condition A, Maximum 23 41 90 75 Maximum
Capacity. Capacity, k=2.
Off-Cycle, Condition A........ .............. .............. 90 75 Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
Table 13--Test Operating Conditions for Variable- or Multiple-Capacity Low-Temperature Outdoor Dedicated
Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test title point, [deg]F [deg]F entering dry- bulb, [deg]F operating mode
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum -22 5 95 75 Minimum
Capacity. Capacity, k=1.
Capacity, Condition A, -22 5 95 75 Minimum
Intermediate Capacity. Capacity, k=i.
Capacity, Condition A, Maximum -22 5 95 75 Maximum
Capacity. Capacity, k=2.
Off-Cycle, Condition A........ .............. .............. 95 75 Compressor Off.
Capacity, Condition B, Minimum -22 5 59 54 Minimum
Capacity. Capacity, k=1.
Capacity, Condition B, -22 5 59 54 Minimum
Intermediate Capacity. Capacity, k=i.
Capacity, Condition B, Maximum -22 5 59 54 Maximum
Capacity. Capacity, k=2.
Off-Cycle, Condition B........ .............. .............. 59 54 Compressor Off.
Capacity, Condition C, Minimum -22 5 35 34 Minimum
Capacity. Capacity, k=1.
Capacity, Condition C, -22 5 35 34 Minimum
Intermediate Capacity. Capacity, k=i.
Capacity, Condition C, Maximum -22 5 35 34 Maximum
Capacity. Capacity, k=2
Off-Cycle, Condition C........ .............. .............. 35 34 Compressor Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
Table 14--Test Operating Conditions for Variable- or Multiple-Capacity Low-Temperature Indoor Dedicated
Condensing Units
----------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew Return gas, Condenser air entering wet- Compressor
Test title point, [deg]F [deg]F entering dry- bulb, [deg]F operating mode
bulb, [deg]F \1\
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum -22 5 90 75 Minimum
Capacity. Capacity, k=1.
Capacity, Condition A, -22 5 90 75 Minimum
Intermediate Capacity. Capacity, k=i.
Capacity, Condition A, Maximum -22 5 90 75 Maximum
Capacity. Capacity, k=2.
Off-Cycle, Condition A........ .............. .............. 90 75 Compressor Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
3.2.5 Test Operating Conditions for Two-Capacity Indoor Matched-Pair or
Single-Packaged Refrigeration Systems
For two-capacity indoor medium-temperature matched-pair or
single-packaged refrigeration systems, conduct tests using the test
conditions specified in table 15 of this appendix. For two-capacity
indoor low-temperature matched-pair or single-packaged refrigeration
systems, conduct tests using the test conditions specified in table
16 of this appendix.
[[Page 28855]]
Table 15--Test Operating Conditions for Two-Capacity Medium-Temperature Indoor Matched-Pair or Single-Packaged
Refrigeration Systems
----------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air entering air entering Condenser air Condenser air Compressor
Test description dry-bulb, relative entering dry- entering wet- status
[deg]F humidity, % bulb, [deg]F bulb, [deg]F
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low 35 <50 90 \1\ 75, \2\ 65 Low Capacity.
Capacity.
Capacity, Condition A, High 35 <50 90 \1\ 75, \2\ 65 High Capacity.
Capacity.
Off-Cycle, Condition A........ 35 <50 90 \1\ 75, \2\ 65 Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units,
where all or part of the equipment is located in the outdoor room.
Table 16--Test Operating Conditions for Two Capacity Low-Temperature Indoor Matched-Pair or Single-Packaged
Refrigeration Systems
----------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Maximum
air entering air entering Condenser air condenser air Compressor
Test description dry-bulb, relative entering dry- entering wet- status
[deg]F humidity, % bulb, [deg]F bulb, [deg]F
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low -10 <50 90 \1\ 75, \2\65 Low Capacity.
Capacity.
Capacity, Condition A, High -10 <50 90 \1\ 75, \2\ 65 High Capacity.
Capacity.
Off-Cycle, Condition A........ -10 <50 90 \1\ 75, \2\ 65 Off.
Defrost....................... -10 <50 .............. .............. System
Dependent.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units,
where all or part of the equipment is located in the outdoor room.
3.2.6 Test Conditions for Variable- or Multiple-Capacity Indoor Matched
Pair or Single-Packaged Refrigeration Systems
For variable- or multiple-capacity indoor medium-temperature
matched-pair or single-packaged refrigeration systems, conduct tests
using the test conditions specified in table 17 of this appendix.
For variable- or multiple-capacity indoor low-temperature matched-
pair or single-packaged refrigeration systems, conduct tests using
the test conditions specified in table 18 of this appendix.
Table 17--Test Operating Conditions for Variable- or Multiple-Capacity Medium-Temperature Indoor Matched-Pair or
Single-Packaged Refrigeration Systems
----------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air entering air entering Condenser air Condenser air Compressor
Test description dry-bulb, relative entering dry- entering wet- status
[deg]F humidity, % bulb, [deg]F bulb, [deg]F
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum 35 <50 90 \1\ 75, \2\ 65 Minimum
Capacity. Capacity.
Capacity, Condition A, 35 <50 90 \1\ 75, \2\ 65 Intermediate
Intermediate Capacity. Capacity.
Capacity, Condition A, High 35 <50 90 \1\ 75, \1\ 65 Maximum
Capacity. Capacity.
Off-Cycle, Condition A........ 35 <50 90 \1\ 75, \2\ 65 Off.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units,
where all or part of the equipment is located in the outdoor room.
Table 18--Test Operating Conditions for Variable- or Multiple-Capacity Low-Temperature Indoor Matched-Pair or
Single-Packaged Refrigeration Systems
----------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Maximum
air entering air entering Condenser air condenser air Compressor
Test description dry-bulb, relative entering dry- entering wet- status
[deg]F humidity, % bulb, [deg]F bulb, [deg]F
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum -10 <50 90 \1\ 75, \2\ 65 Minimum
Capacity. Capacity.
Capacity, Condition A, -10 <50 90 \1\ 75, \2\ 65 Intermediate
Intermediate Capacity. Capacity.
Capacity, Condition A, Maximum -10 <50 90 \1\ 75, \2\ 65 Maximum
Capacity. Capacity.
Off-Cycle, Condition A........ -10 <50 90 \1\ 75, \2\ 65 Off.
[[Page 28856]]
Defrost....................... -10 <50 .............. .............. System
Dependent.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units,
where all or part of the equipment is located in the outdoor room.
3.3 Calculation for Walk-in Box Load
3.3.1 For medium- and low-temperature refrigeration systems with
indoor condensing units, calculate walk-in box loads for high and
low load periods as a function of net capacity as described in
section 6.2.1 of AHRI 1250-2020.
3.3.2 For medium- and low-temperature refrigeration systems with
outdoor condensing units, calculate walk-in box loads for high and
low load periods as a function of net capacity and outdoor
temperature as described in section 6.2.2 of AHRI 1250-2020.
3.3.3 For high-temperature refrigeration systems, calculate
walk-in box load as follows.
BL = 0.5 [middot] qss,A
Where qss,A is the measured net capacity for Test Condition A.
3.4 Calculation for Annual Walk-in Energy Factor (AWEF2)
Calculations used to determine AWEF2 based on performance data
obtained for testing shall be as specified in section 7 of AHRI
1250-2020 with modifications as indicated in sections 3.4.7 through
3.4.10 of this appendix. Calculations used to determine AWEF2 for
refrigeration systems not specifically identified in sections 7.1.1
through 7.1.6 of AHRI 1250-2020 are enumerated in sections 3.4.1
through 3.4.6 and 3.4.11 through 3.4.14 of this appendix.
3.4.1 Two-Capacity Condensing Units Tested Alone, Indoor
3.4.1.1 Unit Cooler Power
Calculate maximum-capacity unit cooler power during the
compressor on period EFcomp,on, in Watts, using Equation 130 of AHRI
1250-2020 for medium-temperature refrigeration systems and using
Equation 173 of AHRI 1250-2020 for low-temperature refrigeration
systems.
Calculate unit cooler power during the compressor off period
EFcomp,off, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
3.4.1.2 Defrost
For freezer refrigeration systems, calculate defrost heat
contribution QDF in Btu/h and the defrost average power consumption
DF in W as a function of steady-state maximum gross refrigeration
capacity Qgrossk=2, as specified in section C10.2.2 of
Appendix C of AHRI 1250-2020.
3.4.1.3 Net Capacity
Calculate steady-state maximum net capacity, qssk=2,
and minimum net capacity, qssk=1 as follows:
qssk=2 = Qgrossk=2 - 3412 [middot] EFcomp,on
qssk=1 = Qgrossk=1 - 3412 [middot] 0.2
[middot] EFcomp,on
Where:
Qgrossk=2 and Qgrossk=1 represent gross
refrigeration capacity at maximum and minimum capacity,
respectively.
3.4.1.4 Calculate average power input during the low load period
as follows.
If the low load period box load, BLL, plus defrost heat
contribution, QDF (only applicable for freezers), is less than the
minimum net capacity qssk=1:
[GRAPHIC] [TIFF OMITTED] TR04MY23.032
Where:
Essk=1 is the steady state condensing unit power input
for minimum-capacity operation.
Ecu,off is the condensing unit off-cycle power input, measured as
described in section C3.5 of AHRI 1250-2020.
If the low load period box load, BLL, plus defrost heat
contribution, QDF, (only applicable for freezers) is greater than
the minimum net capacity qssk=1:
[GRAPHIC] [TIFF OMITTED] TR04MY23.033
[[Page 28857]]
3.4.1.5 Calculate average power input during the high load
period as follows.
[GRAPHIC] [TIFF OMITTED] TR04MY23.034
3.4.1.6 Calculate the AWEF2 as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.035
3.4.2 Variable-Capacity or Multistage Condensing Units Tested Alone,
Indoor
3.4.2.1 Unit Cooler Power
Calculate maximum-capacity unit cooler power during the
compressor on period EFcomp,on as described in section 3.4.1.1 of
this appendix.
Calculate unit cooler power during the compressor off period
EFcomp,off, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
3.4.2.2 Defrost
Calculate Defrost parameters as described in section 4.4.1.2 of
this appendix.
3.4.2.3 Net Capacity
Calculate steady-state maximum net capacity, qssk=2,
intermediate net capacity, qssk=i, and minimum net capacity,
qssk=1 as follows:
qssk=2 = Qgrossk=2 - 3412 [middot] EFcomp,on
qssk=2 = Qgrossk=2 - 3412 [middot] Kf [middot]
EFcomp,on
qssk=1 = Qgrossk=1 - 3412 [middot] 0.2
[middot] EFcomp,on
Where:
Qgrossk=2, Qgrossk=i, Qgross,k=1, and
represent gross refrigeration capacity at maximum, intermediate, and
minimum capacity, respectively.
Kf is the unit cooler power coefficient for
intermediate capacity operation, set equal to 0.2 to represent low-
speed fan operation if the Duty Cycle for a Digital Compressor, the
Speed Ratio for a Variable-Speed Compressor, or the Displacement
Ratio for a Multi-Stage Compressor at Intermediate Capacity is 65%
or less, and otherwise set equal to 1.0.
3.4.2.4 Calculate average power input during the low load period
as follows.
If the low load period box load, BLL, plus defrost heat
contribution QDF (only applicable for freezers) is less than the
minimum net capacity qssk=1:
[GRAPHIC] [TIFF OMITTED] TR04MY23.036
Where Ecu,off, in W, is the condensing unit off-mode power
consumption, measured as described in section C3.5 of AHRI 1250-
2020.
If the low load period box load BLL plus defrost heat
contribution QDF (only applicable for freezers) is greater than the
minimum net capacity qssk=1 and less than the
intermediate net capacity qssk=i:
[GRAPHIC] [TIFF OMITTED] TR04MY23.037
Where:
EERk=1 is the minimum-capacity energy efficiency ratio,
equal to qssk=1 divided by Essk=1 + 0.2
[middot] EFcomp,on; and
EERk=i is the intermediate-capacity energy efficiency
ratio, equal to qssk=i divided by Essk=i + Kf [middot] EFcomp,on.
3.4.2.5 Calculate average power input during the high load
period as follows:
If the high load period box load, BLH, plus defrost heat
contribution, QDF (only applicable for freezers), is greater than
the minimum net capacity qssk=1 and less than the
intermediate net capacity qssk=i:
[[Page 28858]]
[GRAPHIC] [TIFF OMITTED] TR04MY23.038
If the high load period box load, BLH, plus defrost heat
contribution, QDF (only applicable for freezers), is greater than
the intermediate net capacity, qssk=i, and less than the
maximum net capacity, qssk=2:
[GRAPHIC] [TIFF OMITTED] TR04MY23.039
Where:
EERk=2 is the maximum-capacity energy efficiency ratio, equal to
qssk=2 divided by Essk=2 + EFcomp,on
3.4.2.6 Calculate the AWEF2 as follows.
[GRAPHIC] [TIFF OMITTED] TR04MY23.040
3.4.3 Two-Capacity Condensing Units Tested Alone, Outdoor
3.4.3.1 Unit Cooler Power
Calculate maximum-capacity unit cooler power during the
compressor on period EFcomp,on, in Watts, using Equation 153 of AHRI
1250-2020 for medium-temperature refrigeration systems and using
Equation 196 of AHRI 1250-2020 for low-temperature refrigeration
systems.
Calculate unit cooler power during the compressor off period
EFcomp,off, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
3.4.3.2 Defrost
Calculate Defrost parameters as described in section 3.4.1.2 of
this appendix.
3.4.3.3 Condensing Unit Off-Cycle Power
Calculate Condensing Unit Off-Cycle Power for temperature
tj as follows.
[GRAPHIC] [TIFF OMITTED] TR04MY23.041
Where Ecu,off,A and Ecu,off,C are the Condensing Unit off-cycle
power measurements for test conditions A and C, respectively,
measured as described in section C3.5 of AHRI 1250-2020. If
tj is greater than 35 [deg]F and less than 59 [deg]F, use
Equation 157 of AHRI 1250-2020, and if tj is greater than
or equal to 59 [deg]F and less than 95 [deg]F, use Equation 159 of
AHRI 1250-2020.
3.4.3.4 Net Capacity and Condensing Unit Power Input
Calculate steady-state maximum net capacity,
qssk=2(tj), and minimum net capacity,
qssk=1(tj), and corresponding condensing unit power input
levels Essk=2(tj) and Essk=1(tj) as a function
of outdoor temperature tj as follows:
If tj <= 59 [deg]F:
[GRAPHIC] [TIFF OMITTED] TR04MY23.042
[[Page 28859]]
If 59 [deg]F < tj:
[GRAPHIC] [TIFF OMITTED] TR04MY23.043
Where:
The capacity level k can equal 1 or 2;
Qgross,Xk=2 and Qgross,Xk=1 represent gross
refrigeration capacity at maximum and minimum capacity,
respectively, for test condition X, which can take on values A, B,
or C;
Ess,Xk=2 and Ess,Xk=1 represent condensing
unit power input at maximum and minimum capacity, respectively for
test condition X.
3.4.3.5 Calculate average power input during the low load period
as follows.
Calculate the temperature, tIL, in the following
equation which the low load period box load, BLL(tj), plus defrost
heat contribution, QDF (only applicable for freezers), is less than
the minimum net capacity, qssk=1(tj), by solving the
following equation for tIL:
BLL(tIL) + QDF = qssk=1(tIL)
For tj < tIL:
[GRAPHIC] [TIFF OMITTED] TR04MY23.044
Where Ecu,off(tj), in W, is the condensing unit off-mode power
consumption for temperature tj, determined as indicated
in section 3.4.3.3 of this appendix.
For tj >= tIL:
[GRAPHIC] [TIFF OMITTED] TR04MY23.045
3.4.3.6 Calculate average power input during the high load
period as follows.
Calculate the temperature, tIH, in the following
equation which the high load period box load, BLH(tj), plus defrost
heat contribution, QDF (only applicable for freezers), is less than
the minimum net capacity, qssk=1(tj) , by solving the
following equation for tIH:
BLH(tIH) + QDF = qssk=1(tIH)
Calculate the temperature, tIIH, in the following
equation which the high load period box load BLH(tj) plus defrost
heat contribution QDF (only applicable for freezers) is less than
the maximum net capacity qssk=2(tj), by solving the
following equation for tIIH:
BLH(tIIH) + QDF = qssk=1(tIIH)
For tj < tIH:
[[Page 28860]]
[GRAPHIC] [TIFF OMITTED] TR04MY23.046
For tIH <= tj < tIIH:
[GRAPHIC] [TIFF OMITTED] TR04MY23.047
For tIIH <= tj:
EH(tj) = (Essk=2(tj) + EFcomp,on)
3.4.3.7 Calculate the AWEF2 as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.048
3.4.4 Variable-Capacity or Multistage Condensing Units Tested Alone,
Outdoor
3.4.4.1 Unit Cooler Power
Calculate maximum-capacity unit cooler power during the
compressor on period EFcomp,on as described in section 3.4.1.1 of
this appendix.
Calculate unit cooler power during the compressor off period
EFcomp,on, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
3.4.4.2 Defrost
Calculate Defrost parameters as described in section 3.4.1.2 of
this appendix.
3.4.4.3 Condensing Unit Off-Cycle Power
Calculate Condensing Unit Off-Cycle Power for temperature,
tj, as described in section 3.4.3.3 of this appendix.
3.4.4.4 Net Capacity and Condensing Unit Power Input
Calculate steady-state maximum net capacity,
qssk=2(tj), intermediate net capacity,
qssk=i(tj) , and minimum net capacity,
qssk=1(tj), and corresponding condensing unit power input
levels Essk=2(tj), Essk=i(tj),
Essk=1(tj) and as a function of outdoor temperature,
tj, as follows:
If tj <= 59 [deg]F:
[GRAPHIC] [TIFF OMITTED] TR04MY23.049
If 59 [deg]F < tj:
[[Page 28861]]
[GRAPHIC] [TIFF OMITTED] TR04MY23.050
Where:
The capacity level k can equal 1, i, or 2;
Qgross,Xk=2, Qgross,Xk=i and Qgross,Xk=1
represent gross refrigeration capacity at maximum, intermediate, and
minimum capacity, respectively, for test condition X, which can take
on values A, B, or C;
Ess,Xk=2 and Ess,Xk=1 represent condensing
unit power input at maximum and minimum capacity, respectively for
test condition X; and
Kf is the unit cooler power coefficient for intermediate
capacity operation, set equal to 0.2 to represent low-speed fan
operation if the Duty Cycle for a Digital Compressor, the Speed
Ratio for a Variable-Speed Compressor, or the Displacement Ratio for
a Multi-Stage Compressor at Intermediate Capacity is 65% or less,
and otherwise set equal to 1.0.
3.4.4.5 Calculate average power input during the low load period
as follows.
Calculate the temperature, tIL, in the following
equation which the low load period box load BLL(tj) plus defrost
heat contribution, QDF (only applicable for freezers), is less than
the minimum net capacity, qssk=1(tj), by solving the
following equation for tIL:
BLL(tIL) + QDF = qssk=1(tIL)
Calculate the temperature, tVL, in the following
equation which the low load period box load, BLL(tj), plus defrost
heat contribution, QDF (only applicable for freezers), is less than
the intermediate net capacity, qssk=i(tj), by solving the
following equation for tVL:
BLL(tVL) + QDF = qssk=i(tVL)
For tj < tIL:
[GRAPHIC] [TIFF OMITTED] TR04MY23.051
Where, Ecu,off(tj) in W, is the condensing unit off-mode power
consumption for temperature, tj, determined as indicated
in section 3.4.3.3 of this appendix.
For tIL <= tj < tVL:
[GRAPHIC] [TIFF OMITTED] TR04MY23.052
For tVL <= tj:
[GRAPHIC] [TIFF OMITTED] TR04MY23.053
[[Page 28862]]
Where:
EERk=2(tj) is the minimum-capacity energy efficiency
ratio, equal to qssk=1(tj) divided by
Essk=1(tj) + 0.2 EFcomp,on;
EER\k=i\(tj) is the intermediate-capacity energy
efficiency ratio, equal to qssk=i(tj) divided by
Essk=i(tj) + Kf [middot] EFcomp,on; and
EER\k=2\(tj) is the maximum-capacity energy efficiency
ratio, equal to qssk=2(tj) divided by
Essk=2(tj) + EFcomp,on
3.4.4.6 Calculate average power input during the high load
period as follows.
Calculate the temperature tVH in the following
equation which the high load period box load BLH(tj) plus defrost
heat contribution QDF (only applicable for freezers) is less than
the intermediate net capacity qssk=i(tj), by solving the
following equation for tVH:
BLH(tVH) + QDF = qssk=i(tVH)
Calculate the temperature tIIH in the following
equation which the high load period box load BLH(tj) plus defrost
heat contribution QDF (only applicable for freezers) is less than
the maximum net capacity qssk=2(tj), by solving the
following equation for tIIH:
BLH(tIIH) + QDF = qssk=2(tIIH)
For tj < tVH:
[GRAPHIC] [TIFF OMITTED] TR04MY23.054
For tVH <= tj < tIIH:
[GRAPHIC] [TIFF OMITTED] TR04MY23.055
For tIIH <= tj:
EH(tj) = (Essk=2 (tj) + EFcomp,on)
3.4.4.7 Calculate the AWEF2 as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.056
3.4.5 Two-Capacity Indoor Matched Pairs or Single-Packaged
Refrigeration Systems Other Than High-Temperature
3.4.5.1 Defrost
For freezer refrigeration systems, defrost heat contribution QDF
in Btu/h and the defrost average power consumption DF in W shall be
as measured in accordance with section C10.2.1 of Appendix C of AHRI
1250-2020.
3.4.5.2 Calculate average power input during the low load period
as follows.
If the low load period box load BLL plus defrost heat
contribution QDF (only applicable for freezers) is less than the
minimum net capacity qssk=1:
[GRAPHIC] [TIFF OMITTED] TR04MY23.057
Where:
qssk=1 and Essk=1 are the steady state
refrigeration system minimum net capacity, in Btu/h, and associated
refrigeration system power input, in W, respectively, for minimum-
capacity operation, measured as described in AHRI 1250-2020.
EFcomp,off and Ecu,off, both in W, are the unit cooler and
condensing unit, respectively, off-mode power consumption, measured
as described in section C3.5 of AHRI 1250-2020.
If the low load period box load BLL plus defrost heat
contribution QDF (only applicable for freezers) is greater than the
minimum net capacity qssk=1:
[[Page 28863]]
[GRAPHIC] [TIFF OMITTED] TR04MY23.058
Where qssk=2 and Essk=2 are the steady state
refrigeration system maximum net capacity, in Btu/h, and associated
refrigeration system power input, in W, respectively, for maximum-
capacity operation, measured as described in AHRI 1250-2020.
3.4.5.3 Calculate average power input during the high load
period as follows.
[GRAPHIC] [TIFF OMITTED] TR04MY23.059
3.4.5.4 Calculate the AWEF2 as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.060
3.4.6 Variable-Capacity or Multistage Indoor Matched Pairs or Single-
Packaged Refrigeration Systems Other Than High-Temperature
3.4.6.1 Defrost
For freezer refrigeration systems, defrost heat contribution QDF
in Btu/h and the defrost average power consumption DF in W shall be
as measured in accordance with section C10.2.1 of Appendix C of AHRI
1250-2020.
3.4.6.2 Calculate average power input during the low load period
as follows.
If the low load period box load BLL plus defrost heat
contribution QDF (only applicable for freezers) is less than the
minimum net capacity qssk=1:
[GRAPHIC] [TIFF OMITTED] TR04MY23.061
Where:
qssk=1 and Essk=1 are the steady state
refrigeration system minimum net capacity, in Btu/h, and associated
refrigeration system power input, in W, respectively, for minimum-
capacity operation, measured as described in AHRI 1250-2020; and
EFcomp,off and Ecu,off, both in W, are the unit cooler and
condensing unit, respectively, off-mode power consumption, measured
as described in section C3.5 of AHRI 1250-2020.
If the low load period box load BLL plus defrost heat
contribution QDF (only applicable for freezers) is greater than the
minimum net capacity and less than the intermediate net capacity
qssk=i:
[GRAPHIC] [TIFF OMITTED] TR04MY23.062
[[Page 28864]]
Where:
EERk=1 is the minimum-capacity energy efficiency ratio,
equal to qssk=1divided by Essk=1;
qssk=i and Essk=i are the steady state refrigeration system
intermediate net capacity, in Btu/h, and associated refrigeration
system power input, in W, respectively, for intermediate-capacity
operation, measured as described in AHRI 1250-2020.
EERk=i is the intermediate-capacity energy efficiency
ratio, equal to qssk=i divided by Essk=i.
3.4.6.3 Calculate average power input during the high load
period as follows.
If the high load period box load BLH plus defrost heat
contribution QDF (only applicable for freezers) is greater than the
minimum net capacity qssk=1 and less than the
intermediate net capacity qssk=i:
[GRAPHIC] [TIFF OMITTED] TR04MY23.063
If the high load period box load BLH plus defrost heat
contribution QDF (only applicable for freezers) is greater than the
intermediate net capacity qssk=i and less than the maximum net
capacity qssk=2:
[GRAPHIC] [TIFF OMITTED] TR04MY23.064
Where:
qssk=2 and Essk=2 are the steady state
refrigeration system maximum net capacity, in Btu/h, and associated
refrigeration system power input, in W, respectively, for maximum-
capacity operation, measured as described in AHRI 1250-2020; and
EER\k=2\ is the maximum-capacity energy efficiency ratio, equal to
qssk=2 divided by Essk=2.
3.4.6.4 Calculate the AWEF2 as follows.
[GRAPHIC] [TIFF OMITTED] TR04MY23.065
3.4.7 Variable-Capacity or Multistage Outdoor Matched Pairs or Single-
Packaged Refrigeration Systems Other Than High-Temperature
Calculate AWEF2 as described in section 7.6 of AHRI 1250-2020,
with the following revisions.
3.4.7.1 Condensing Unit Off-Cycle Power
Calculate condensing unit off-cycle power for temperature
tj as indicated in section 3.4.3.3 of this appendix.
Replace the constant value ECU,off in Equations 55 and 70 of AHRI
1250-2020 with the values ECU,off(tj), which vary with outdoor
temperature tj.
3.4.7.2 Unit Cooler Off-Cycle Power
Set unit cooler Off-Cycle power EFcomp,off equal to the average
of the unit cooler off-cycle power measurements made for test
conditions A, B, and C.
3.4.7.3 Average Power During the Low Load Period
Calculate average power for intermediate-capacity compressor
operation during the low load period Ess,Lk=v(tj) as described in
section 7.6 of AHRI 1250-2020, except that, instead of calculating
intermediate-capacity compressor EER using Equation 77 of AHRI 1250-
2020, calculate EER as follows.
For tj < tVL:
[GRAPHIC] [TIFF OMITTED] TR04MY23.066
For tVL <= tj:
[GRAPHIC] [TIFF OMITTED] TR04MY23.067
[[Page 28865]]
Where:
EERk=1(tj) is the minimum-capacity energy
efficiency ratio, equal to qssk=1(tj) divided by
Essk=1(tj);
EERk=i(tj) is the intermediate-capacity energy
efficiency ratio, equal to qssk=i (tj) divided by Essk=i(tj); and
EERk=2(tj) is the maximum-capacity energy
efficiency ratio, equal to qssk=2(tj) divided by
Essk=2(tj)
3.4.7.4 Average Power During the High Load Period
Calculate average power for intermediate-capacity compressor
operation during the high load period Ess,Hk=v(tj) as described in
section 7.6 of AHRI 1250-2020, except that, instead of calculating
intermediate-capacity compressor EER using Equation 61 of AHRI 1250-
2020, calculate EER as follows:
For tj < tVH:
[GRAPHIC] [TIFF OMITTED] TR04MY23.068
For tVH <= tj:
[GRAPHIC] [TIFF OMITTED] TR04MY23.069
3.4.8 Two-Capacity Outdoor Matched Pairs or Single-Packaged
Refrigeration Systems Other Than High-Temperature
Calculate AWEF2 as described in section 7.5 of AHRI 1250-2020,
with the following revisions for Condensing Unit Off-Cycle Power and
Unit Cooler Off-Cycle Power. Calculate condensing unit off-cycle
power for temperature tj as indicated in section 3.4.3.3
of this appendix. Replace the constant value ECU,off in Equations 13
and 29 of AHRI 1250-2020 with the values ECU,off(tj), which vary
with outdoor temperature tj. Set unit cooler Off-Cycle
power EFcomp,off equal to the average of the unit cooler off-cycle
power measurements made for test conditions A, B, and C.
3.4.9 Single-Capacity Outdoor Matched Pairs or Single-Packaged
Refrigeration Systems Other Than High-Temperature
Calculate AWEF2 as described in section 7.4 of AHRI 1250-2020,
with the following revision for Condensing Unit Off-Cycle Power and
Unit Cooler Off-cycle Power. Calculate condensing unit off-cycle
power for temperature tj as indicated in section 3.4.3.3
of this appendix. Replace the constant value ECU,off in Equations 13
of AHRI 1250-2020 with the values ECU,off(tj), which vary with
outdoor temperature tj. Set unit cooler Off-Cycle power
EFcomp,off equal to the average of the unit cooler off-cycle power
measurements made for test conditions A, B, and C.
3.4.10 Single-Capacity Condensing Units, Outdoor
Calculate AWEF2 as described in section 7.9 of AHRI 1250-2020,
with the following revision for Condensing Unit Off-Cycle Power.
Calculate condensing unit off-cycle power for temperature
tj as indicated in section 3.4.3.3 of this appendix
rather than as indicated in Equations 157, 159, 202, and 204 of AHRI
1250-2020.
3.4.11 High-Temperature Matched Pairs or Single-Packaged Refrigeration
Systems, Indoor
3.4.11.1 Calculate Load Factor LF as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.070
Where:
BL, in Btu/h is the non-equipment-related box load calculated as
described in section 3.3.3 of this appendix;
EFcomp,off, in W, is the unit cooler off-cycle power consumption,
equal to 0.1 times the unit cooler on-cycle power consumption; and
qss,A, in Btu/h is the measured net capacity for test condition A.
3.4.11.2 Calculate the AWEF2 as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.071
Where:
Ess,A, in W, is the measured system power input for test condition
A; and
Ecu,off, in W, is the condensing unit off-cycle power consumption,
measured as described in section C3.5 of AHRI 1250-2020.
3.4.12 High-Temperature Matched Pairs or Single-Packaged Refrigeration
Systems, Outdoor
3.4.12.1 Calculate Load Factor LF(tj) for outdoor
temperature tj as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.072
[[Page 28866]]
Where:
BL, in Btu/h, is the non-equipment-related box load calculated as
described in section 3.3.3 of this appendix;
EFcomp,off, in W, is the unit cooler off-cycle power consumption,
equal to 0.1 times the unit cooler on-cycle power consumption; and
qss(tj), in Btu/h, is the net capacity for outdoor temperature
tj, calculated as described in section 7.4.2 of AHRI
1250-2020.
3.4.12.2 Calculate the AWEF2 as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.073
Where:
Ess(tj), in W, is the system power input for temperature
tj, calculated as described in section 7.4.2 of AHRI
1250-2020;
Ecu,off, in W, is the condensing unit off-cycle power consumption,
measured as described in section C3.5 of AHRI 1250-2020; and
nj are the hours for temperature bin j.
3.4.13 High-Temperature Unit Coolers Tested Alone
3.4.13.1 Calculate Refrigeration System Power Input as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.074
Where:
qmix,evap, in W, is the net evaporator capacity, measured as
described in AHRI 1250-2020;
EFcomp,on, in W, is the unit cooler on-cycle power consumption; and
EER, in W, equals
[GRAPHIC] [TIFF OMITTED] TR04MY23.075
3.4.13.2 Calculate the load factor LF as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.076
Where:
BL, in Btu/h, is the non-equipment-related box load calculated as
described in section 3.3.3 of this appendix; and
EFcomp,off, in W, is the unit cooler off-cycle power consumption,
equal to 0.1 times the unit cooler on-cycle power consumption.
3.4.13.3 Calculate AWEF2 as follows:
[GRAPHIC] [TIFF OMITTED] TR04MY23.077
3.4.14 CO2 Unit Coolers Tested Alone
Calculate AWEF2 for CO2 Unit Coolers Tested Alone
using the calculations specified in in section 7.8 of AHRI 1250-2020
for calculation of AWEF2 for Unit Cooler Tested Alone.
3.5 Test Method
Test the Refrigeration System in accordance with AHRI 1250-2020
to determine refrigeration capacity and power input for the
specified test conditions, with revisions and additions as described
in this section.
3.5.1 Chamber Conditioning Using the Unit Under Test
In Appendix C, section C5.2.2 of AHRI 1250-2020, for applicable
system configurations (matched pairs, single-packaged refrigeration
systems, and standalone unit coolers), the unit under test may be
used to aid in achieving the required test chamber conditions prior
to beginning any steady state test. However, the unit under test
must be inspected and confirmed to be free from frost before
initiating steady state testing.
3.5.2 General Modification: Methods of Testing
3.5.2.1 Refrigerant Temperature Measurements
When testing a condensing unit alone, measure refrigerant liquid
temperature leaving the condensing unit, and the refrigerant vapor
temperature entering the condensing unit as required in section
C7.5.1.1.2 of Appendix C of AHRI 1250-2020 using the same
measurement approach specified for the unit cooler in section C3.1.3
of Appendix C of AHRI 1250-2020. In all cases in which thermometer
wells or immersed sheathed sensors are prescribed, if the
refrigerant tube outer diameter is less
[[Page 28867]]
than \1/2\ inch, the refrigerant temperature may be measured using
the average of two temperature measuring instruments with a minimum
accuracy of 0.5 [deg]F placed on opposite sides of the
refrigerant tube surface--resulting in a total of up to 8
temperature measurement devices used for the DX Dual Instrumentation
method. In this case, the refrigerant tube shall be insulated with
1-inch thick insulation from a point 6 inches upstream of the
measurement location to a point 6 inches downstream of the
measurement location. Also, to comply with this requirement, the
unit cooler/evaporator entering measurement location may be moved to
a location 6 inches upstream of the expansion device and, when
testing a condensing unit alone, the entering and leaving
measurement locations may be moved to locations 6 inches from the
respective service valves.
3.5.2.2 Mass Flow Meter Location
When using the DX Dual Instrumentation test method of AHRI 1250-
2020, applicable for unit coolers, dedicated condensing units, and
matched pairs, the second mass flow meter may be installed in the
suction line as shown in Figure C1 of AHRI 1250-2020.
3.5.2.3 Subcooling at Refrigerant Mass Flow Meter
In section C3.4.5 of Appendix C of AHRI 1250-2020, when
verifying subcooling at the mass flow meters, only the sight glass
and a temperature sensor located on the tube surface under the
insulation are required. Subcooling shall be verified to be within
the 3 [deg]F requirement downstream of flow meters located in the
same chamber as a condensing unit under test and upstream of flow
meters located in the same chamber as a unit cooler under test,
rather than always downstream as indicated in AHRI 1250-2009,
section C3.4.5. If the subcooling is less than 3 [deg]F when testing
a unit cooler, dedicated condensing unit, or matched pair (not a
single-packaged system), cool the line between the condensing unit
outlet and this location to achieve the required subcooling. When
providing such cooling while testing a matched pair (a) set up the
line-cooling system and also set up apparatus to heat the liquid
line between the mass flow meters and the unit cooler, (b) when the
system has achieved steady state without activation of the heating
and cooling systems, measure the liquid temperature entering the
expansion valve for a period of at least 30 minutes, (c) activate
the cooling system to provide the required subcooling at the mass
flow meters, (d) if necessary, apply heat such that the temperature
entering the expansion valve is within 0.5 [deg]F of the temperature
measured during step (b), and (e) proceed with measurements once
condition (d) has been verified.
3.5.2.4 Installation Instructions
Manufacturer installation instructions or installation
instructions described in this section refer to the instructions
that come packaged with or appear on the labels applied to the unit.
This does not include online manuals.
Installation Instruction Hierarchy: If a given installation
instruction provided on the label(s) applied to the unit conflicts
with the installation instructions that are shipped with the unit,
the label takes precedence. For testing of matched pairs, the
installation instructions for the dedicated condensing unit shall
take precedence. Setup shall be in accordance with the field
installation instructions (laboratory installation instructions
shall not be used). Achieving test conditions shall always take
precedence over installation instructions.
3.5.2.5. Refrigerant Charging and Adjustment of Superheat and
Subcooling.
All dedicated condensing systems (dedicated condensing units
tested alone, matched pairs, and single packaged dedicated systems)
that use flooding of the condenser for head pressure control during
low-ambient-temperature conditions shall be charged, and superheat
and/or subcooling shall be set, at Refrigeration C test conditions
unless otherwise specified in the installation instructions.
If after being charged at Refrigeration C condition the unit
under test does not operate at the Refrigeration A condition due to
high pressure cut out, refrigerant shall be removed in increments of
4 ounces or 5 percent of the test unit's receiver capacity,
whichever quantity is larger, until the unit operates at the
Refrigeration A condition. All tests shall be run at this final
refrigerant charge. If less than 0 [deg]F of subcooling is measured
for the refrigerant leaving the condensing unit when testing at B or
C condition, calculate the refrigerant-enthalpy-based capacity
(i.e., when using the DX dual instrumentation, the DX calibrated
box, or single-packaged unit refrigerant enthalpy method) assuming
that the refrigerant is at saturated liquid conditions at the
condensing unit exit.
All dedicated condensing systems that do not use a flooded
condenser design shall be charged at Refrigeration A test conditions
unless otherwise specified in the installation instructions.
If the installation instructions give a specified range for
superheat, sub-cooling, or refrigerant pressure, the average of the
range shall be used as the refrigerant charging parameter target and
the test condition tolerance shall be 50 percent of the
range. Perform charging of near-azeotropic and zeotropic
refrigerants only with refrigerant in the liquid state. Once the
correct refrigerant charge is determined, all tests shall run until
completion without further modification.
3.5.2.5.1. When charging or adjusting superheat/subcooling, use
all pertinent instructions contained in the installation
instructions to achieve charging parameters within the tolerances.
However, in the event of conflicting charging information between
installation instructions, follow the installation instruction
hierarchy listed in section 3.5.2.4. Conflicting information is
defined as multiple conditions given for charge adjustment where all
conditions specified cannot be met. In the event of conflicting
information within the same set of charging instructions (e.g., the
installation instructions shipped with the dedicated condensing
unit), follow the hierarchy in Table 19 for priority. Unless the
installation instructions specify a different charging tolerance,
the tolerances identified in table 19 of this appendix shall be
used.
Table 19--Test Condition Tolerances and Hierarchy for Refrigerant Charging and Setting of Refrigerant Conditions
----------------------------------------------------------------------------------------------------------------
Fixed orifice Expansion Valve
-------------------------------------------------------------------------------------------------
Priority Parameter with Parameter with
installation Tolerance installation Tolerance
instruction target instruction target
----------------------------------------------------------------------------------------------------------------
1............. Superheat............ 2.0 [deg]F....... Subcooling.......... 10% of the Target
Value; No less than
0.5
[deg]F, No more
than 2.0 [deg]F
2............. High Side Pressure or 4.0 psi or 4.0 psi
Saturation minus>1.0 [deg]F. or Saturation or
Temperature*. Temperature*. 1.0
[deg]F
3............. Low Side Pressure or 2.0 psi or 2.0
Saturation minus>0.8 [deg]F. [deg]F
Temperature*.
4............. Low Side Temperature. 2.0 [deg]F....... Low Side Pressure or 2.0 psi
Saturation or
Temperature *. 0.8
[deg]F
5............. High Side Temperature 2.0 [deg]F....... Approach Temperature 1.0
[deg]F
6............. Charge Weight........ 2.0 oz........... Charge Weight....... 0.5% or 1.0 oz,
whichever is
greater
----------------------------------------------------------------------------------------------------------------
* Saturation temperature can refer to either bubble or dew point calculated based on a measured pressure, or a
coil temperature measurement, as specified by the installation instructions.
[[Page 28868]]
3.5.2.5.2. Dedicated Condensing Unit.
If the Dedicated Condensing Unit includes a receiver and the
subcooling target leaving the condensing unit provided in
installation instructions cannot be met without fully filling the
receiver, the subcooling target shall be ignored. Likewise, if the
Dedicated Condensing unit does not include a receiver and the
subcooling target leaving the condensing unit cannot be met without
the unit cycling off on high pressure, the subcooling target can be
ignored. Also, if no instructions for charging or for setting
subcooling leaving the condensing unit are provided in the
installation instructions, the refrigeration system shall be set up
with a charge quantity and/or exit subcooling such that the unit
operates during testing without shutdown (e.g., on a high-pressure
switch) and operation of the unit is otherwise consistent with the
requirements of the test procedure of this appendix and the
installation instructions.
3.5.2.5.3. Unit Cooler. Use the shipped expansion device for
testing. Otherwise, use the expansion device specified in the
installation instructions. If the installation instructions specify
multiple options for the expansion device, any specified expansion
device may be used. The supplied expansion device shall be adjusted
until either the superheat target is met, or the device reaches the
end of its adjustable range. In the event the device reaches the end
of its adjustable range and the super heat target is not met, test
with the adjustment at the end of its range providing the closest
match to the superheat target, and the test condition tolerance for
super heat target shall be ignored. The measured superheat is not
subject to a test operating tolerance. However, if the evaporator
exit condition is used to determine capacity using the DX dual
instrumentation method or the refrigerant enthalpy method,
individual superheat value measurements may not be equal to or less
than zero. If this occurs, or if the operating tolerances of
measurements affected by expansion device fluctuation are exceeded,
the expansion device shall be replaced, operated at an average
superheat value higher than the target, or both, in order to avoid
individual superheat value measurements less than zero and/or to
meet the required operating tolerances.
3.5.2.5.4. Single-Packaged Unit. Unless otherwise directed by
the installation instructions, install one or more refrigerant line
pressure gauges during the setup of the unit, located depending on
the parameters used to verify or set charge, as described in this
section:
3.5.2.5.4.1. Install a pressure gauge in the liquid line if
charging is on the basis of subcooling, or high side pressure or
corresponding saturation or dew point temperature.
3.5.2.5.4.2. Install a pressure gauge in the suction line if
charging is on the basis of superheat, or low side pressure or
corresponding saturation or dew point temperature. Install this
gauge as close to the evaporator as allowable by the installation
instructions and the physical constraints of the unit. Use methods
for installing pressure gauge(s) at the required location(s) as
indicated in the installation instructions if specified.
3.5.2.5.4.3. If the installation instructions indicate that
refrigerant line pressure gauges should not be installed and the
unit fails to operate due to high-pressure or low-pressure
compressor cut off, then a charging port shall be installed, and the
unit shall be evacuated of refrigerant and charged to the nameplate
charge.
3.5.2.6 Ducted Units
For systems with ducted evaporator air, or that can be installed
with or without ducted evaporator air: Connect ductwork on both the
inlet and outlet connections and determine external static pressure
(ESP) as described in sections 6.4 and 6.5 of ANSI/ASHRAE 37. Use
pressure measurement instrumentation as described in section 5.3.2
of ANSI/ASHRAE 37. Test at the fan speed specified in the
installation instructions--if there is more than one fan speed
setting and the installation instructions do not specify which speed
to use, test at the highest speed. Conduct tests with the ESP equal
to 50% of the maximum ESP allowed in the installation instructions,
within a tolerance of -0.00/+0.05 inches of water column. If the
installation instructions do not provide the maximum ESP, the ESP
shall be set for testing such that the air volume rate is \2/3\ of
the air volume rate measured when the ESP is 0.00 inches of water
column within a tolerance of -0.00/+0.05 inches of water column.
If testing using either the indoor or outdoor air enthalpy
method to measure the air volume rate, adjust the airflow
measurement apparatus fan to set the external static pressure--
otherwise, set the external static pressure by symmetrically
restricting the outlet of the test duct. In case of conflict, these
requirements for setting airflow take precedence over airflow values
specified in manufacturer installation instructions or product
literature.
3.5.2.7. Two-Speed or Multiple-Speed Evaporator Fans. Two-Speed
or Multiple-Speed evaporator fans shall be considered to meet the
qualifying control requirements of section C4.2 of Appendix C of
AHRI 1250-2020 for measuring off-cycle fan energy if they use a fan
speed no less than 50% of the speed used in the maximum capacity
tests.
3.5.2.8. Defrost
Use section C10.2.1 of Appendix C of AHRI 1250-2020 for defrost
testing. The Test Room Conditioning Equipment requirement of section
C10.2.1.1 of Appendix C of AHRI 1250-2020 does not apply.
3.5.2.8.1 Adaptive Defrost
When testing to certify compliance to the energy conservation
standards, use NDF = 4, as instructed in section
C10.2.1.7 or C10.2.2.1 of AHRI 1250-2020. When determining the
represented value of the calculated benefit for the inclusion of
adaptive defrost, use NDF = 2.5, as instructed in section
C10.2.1.7 or C10.2.2.1 of AHRI 1250-2020.
3.5.2.8.2 Hot Gas Defrost
When testing to certify compliance to the energy conservation
standards, remove the hot gas defrost mechanical components and
disconnect all such components from electrical power. Test the units
as if they are electric defrost units, but do not conduct the
defrost tests described in section C10.2.1 of AHRI 1250-2020. Use
the defrost heat and power consumption values as described in
section C10.2.2 of AHRI 1250-2020 for the AWEF2 calculations.
3.5.2.9 Dedicated condensing units that are not matched for
testing and are not single-packaged dedicated systems.
The temperature measurement requirements of sections C3.1.3 and
C4.1.3.1 appendix C of AHRI 1250-2020 shall apply only to the
condensing unit exit rather than to the unit cooler inlet and
outlet, and they shall be applied for two measurements when using
the DX Dual Instrumentation test method.
3.5.2.10. Single-packaged dedicated systems
Use the test method in section C9 of appendix C of AHRI 1250-
2020 (including the applicable provisions of ASHRAE 16-2016, ASHRAE
23.1-2010, ASHRAE 37-2009, and ASHRAE 41.6-2014, as referenced in
section C9.1 of AHRI 1250-2020) as the method of test for single-
packaged dedicated systems, with modifications as described in this
section. Use two test methods listed in table 20 of this appendix to
calculate the net capacity and power consumption. The test method
listed with a lower ``Hierarchy Number'' and that has ``Primary'' as
an allowable use in table 20 of this appendix shall be considered
the primary measurement and used as the net capacity.
Table 20--Single-Packaged Methods of Test and Hierarchy
------------------------------------------------------------------------
Hierarchy number Method of test Test hierarchy
------------------------------------------------------------------------
1........................... Balanced Ambient Primary.
Indoor Calorimeter.
2........................... Indoor Air Enthalpy. Primary or
Secondary.
3........................... Indoor Room Primary or
Calorimeter. Secondary.
4........................... Calibrated Box...... Primary or
Secondary.
5........................... Balanced Ambient Secondary.
Outdoor Calorimeter.
6........................... Outdoor Air Enthalpy Secondary.
7........................... Outdoor Room Secondary.
Calorimeter.
8........................... Single-Packaged Secondary.
Refrigerant
Enthalpy \1\.
[[Page 28869]]
9........................... Compressor Secondary.
Calibration.
------------------------------------------------------------------------
Notes:
\1\ See description of the single-packaged refrigerant enthalpy method
in section 3.5.2.10.1 of this appendix.
3.5.2.10.1 Single-Packaged Refrigerant Enthalpy Method
The single-packaged refrigerant enthalpy method shall follow the
test procedure of the DX Calibrated Box method in AHRI 1250-2020,
appendix C, section C8 for refrigerant-side measurements with the
following modifications:
3.5.2.10.1.1 Air-side measurements shall follow the requirements
of the primary single-packaged method listed in table 20 of this
appendix. The air-side measurements and refrigerant-side
measurements shall be collected over the same intervals.
3.5.2.10.1.2 A preliminary test at Test Rating Condition A is
required using the primary method prior to any modification
necessary to install the refrigerant-side measuring instruments.
Install surface mount temperature sensors on the evaporator and
condenser coils at locations not affected by liquid subcooling or
vapor superheat (i.e., near the midpoint of the coil at a return
bend), entering and leaving the compressor, and entering the
expansion device. These temperature sensors shall be included in the
regularly recorded data.
3.5.2.10.1.3 After the preliminary test is completed, the
refrigerant shall be removed from the equipment and the refrigerant-
side measuring instruments shall be installed. The equipment shall
then be evacuated and recharged with refrigerant. Once the equipment
is operating at Test Condition A, the refrigerant charge shall be
adjusted until, as compared to the average values from the
preliminary test, the following conditions are achieved:
(a) Each on-coil temperature sensor indicates a reading that is
within 1.0 [deg]F of the measurement in the initial
test,
(b) The temperatures of the refrigerant entering and leaving the
compressor are within 4 [deg]F, and
(c) The refrigerant temperature entering the expansion device is
within 1 [deg]F.
3.5.2.10.1.4 Once these conditions have been achieved over an
interval of at least 10 minutes, refrigerant charging equipment
shall be removed and the official tests shall be conducted.
3.5.2.10.1.5 The lengths of liquid line to be added shall be 5
feet maximum, not including the requisite flow meter. This maximum
length applies to each circuit separately.
3.5.2.10.1.6 Use section C9.2 of appendix C of AHRI 1250-2020
for allowable refrigeration capacity heat balance. Calculate the
single-packaged refrigerant enthalpy (secondary) method test net
capacity
Qnet,secondary as follows: Qnet,secondary = Qref-
3.412[middot]EFcomp,on-Qsploss
Where:
Qref is the gross capacity;
EFcomp,on is the evaporator compartment on-cycle power, including
evaporator fan power; and
Qsploss is a duct loss calculation applied to the evaporator
compartment of the single-packaged systems, which is calculated as
indicated in the following equation.
Qsploss = UAcond x (Tevapside - Tcondside) + UAamb x (Tevapside -
Tamb)
Where:
UAcond and UAamb are, for the condenser/
evaporator partition and the evaporator compartment walls exposed to
ambient air, respectively, the product of the overall heat transfer
coefficient and surface area of the unit as manufactured, i.e.
without external insulation that might have been added during the
test. The areas shall be calculated based on measurements, and the
thermal resistance values shall be based on insulation thickness and
insulation material;
Tevapside is the air temperature in the evaporator
compartment--the measured evaporator air inlet temperature may be
used;
Tcondside is the air temperature in the condenser
compartment--the measured chamber ambient temperature may be used,
or a measurement may be made using a temperature sensor placed
inside the condenser box at least 6 inches distant from any part of
the refrigeration system; and
Tamb is the air temperature outside the single-
packaged system.
3.5.2.10.1.7 For multi-circuit single-packaged systems utilizing
the single-packaged refrigerant enthalpy method, apply the test
method separately for each circuit and sum the separately-calculated
refrigerant-side gross refrigeration capacities.
3.5.2.10.2 Calibrated Box Test Procedure
3.5.2.10.2.1 Measurements. Refer to section C3 of AHRI 1250-2020
(including the applicable provisions of ASHRAE 41.1-2013, ASHRAE
41.3-2014, and ASHRAE 41.10-2013, as referenced in section C3 of
AHRI 1250-2020) for requirements of air-side and refrigerant-side
measurements.
3.5.2.10.2.2 Apparatus setup for Calibrated Box Calibration and
Test. Refer to section C5 of AHRI 1250-2020 and section C8 of AHRI
1250-2020 for specific test setup.
3.5.2.10.2.3 The calibrated box shall be installed in a
temperature-controlled enclosure in which the temperature can be
maintained at a constant level. When using the calibrated box method
for Single-Packaged Dedicated Systems, the enclosure air temperature
shall be maintained such that the condenser air entering conditions
are as specified for the test.
3.5.2.10.2. The temperature-controlled enclosure shall be of a
size that will provide clearances of not less than 18 in at all
sides, top and bottom, except that clearance of any one surface may
be reduced to not less than 5.5 inches.
3.5.2.10.2.5 The heat leakage of the calibrated box shall be
noted in the test report.
3.5.2.10.2.6 Refrigerant lines within the calibrated box shall
be well insulated to avoid appreciable heat loss or gain.
3.5.2.10.2.7 Instruments for measuring the temperature around
the outside of the calibrated box to represent the enclosure
temperature Ten shall be located at the center of each
wall, ceiling, and floor. Exception: in the case where a clearance
around the outside of the calibrated box, as indicated in section
3.5.2.10.2.4 of this appendix, is reduced to less than 18 inches,
the number of temperature measuring devices on the outside of that
surface shall be increased to six, which shall be treated as a
single temperature to be averaged with the temperature of each of
the other five surfaces. The six temperature measuring instruments
shall be located at the center of six rectangular sections of equal
area. If the refrigeration system is mounted at the location that
would cover the center of the face on which it is mounted, up to
four temperature measurements shall be used on that face to
represent its temperature. Each sensor shall be aligned with the
center of the face's nearest outer edge and centered on the distance
between that edge and the single-packaged unit (this is illustrated
in figure C5 of this section when using surface temperature
sensors), and they shall be treated as a single temperature to be
averaged with the temperature of each of the other five surfaces.
However, any of these sensors shall be omitted if either (a) the
distance between the outer edge and the single-packaged unit is less
than one foot or (b) if the sensor location would be within two feet
of any of the foot square surfaces discussed in section 3.5.2.10.2.8
of this appendix representing a warm discharge air impingement area.
In this case, the remaining sensors shall be used to represent the
average temperature for the surface.
3.5.2.10.2.8 One of the following two approaches shall be used
for the box external temperature measurement. Box calibration and
system capacity measurement shall both be done using the same one of
these approaches. 1: Air temperature sensors. Each temperature
sensor shall be at a distance of 6 inches from the calibrated box.
If the clearance from a surface of the box (allowed for one surface
only) is less than 12 inches, the temperature measuring instruments
shall be located midway between the outer wall of the calibrated box
and the adjacent surface. 2: Surface temperature sensors. Surface
temperature sensors shall be mounted on the calibrated box surfaces
to represent the enclosure temperature, Ten.
3.5.2.10.2.9 Additional surface temperature sensors may be used
to measure external hot spots during refrigeration system
[[Page 28870]]
testing. If this is done, two temperature sensors shall be used to
measure the average temperature of the calibrated box surface
covered by the condensing section--they shall be located centered on
equal-area rectangles comprising the covered calibrated box surface
whose common sides span the short dimension of this surface.
Additional surface temperature sensors may be used to measure box
surfaces on which warm condenser discharge air impinges. A pattern
of square surfaces measuring one foot square shall be mapped out to
represent the hot spot upon which the warm condenser air impinges.
One temperature sensor shall be used to measure surface temperature
at the center of each square (see figure C5 of this section). A
drawing showing this pattern and identifying the surface temperature
sensors shall be provided in the test report. The average surface
temperature of the overall calibrated box outer surface during
testing shall be calculated as follows.
[GRAPHIC] [TIFF OMITTED] TR04MY23.078
Where:
Ai is the surface area of the ith of the six calibrated box
surfaces;
Ti is the average temperature measured for the ith surface;
Aj is half of the surface area of the calibrated box covered by the
condensing section;
T'j is the jth of the two temperature measurements underneath the
condensing section;
T1 is the average temperature of the four or fewer measurements
representing the temperature of the face on which the single-
packaged system is mounted, prior to adjustments associated with hot
spots based on measurements Tj and/or Tk;
Ak is the area of the kth of n 1-square-foot surfaces used to
measure the condenser discharge impingement area hot spot; and,
T''k is the kth of the n temperature measurements of the condenser
discharge impingement area hot spot.
[GRAPHIC] [TIFF OMITTED] TR04MY23.079
Figure C5: Illustration of Layout of Surface Temperature Sensors on
Face of Calibrated Box on which Single-Packaged Dedicated System is
Mounted when Using Section 3.5.2.10.2.7 of Appendix C to this
Part.3.5.2.10.2.10 Heating means inside the calibrated box shall be
shielded or installed in a manner to avoid radiation to the Single-
Packaged Dedicated System, the temperature measuring instruments,
and to the walls of the box. The heating means shall be constructed
to avoid stratification of temperature, and suitable means shall be
provided for distributing the temperature uniformly.
3.5.2.10.2.11 The average air dry-bulb temperature in the
calibrated box during Single-Packaged Dedicated System tests and
calibrated box heat leakage tests shall be the average of eight
temperatures measured at the corners of the box at a distance of 2
inches to 4 inches from the walls. The instruments shall be shielded
from any cold or warm surfaces except that they shall not be
shielded from the adjacent walls of the box. The Single-Packaged
Dedicated System under test shall be mounted such that the
[[Page 28871]]
temperature instruments are not in the direct air stream from the
discharge of the Single-Packaged Dedicated System.
3.5.2.10.2.12 Calibration of the Calibrated Box. Calibration of
the Calibrated Box shall occur prior to installation of the Single-
Packaged Dedicated System. This shall be done either (a) prior to
cutting the opening needed to install the Single-Packaged Dedicated
System, or (b) with an insulating panel with the same thickness and
thermal resistance as the box wall installed in the opening intended
for the Single-Packaged Dedicated System installation. Care shall be
taken to avoid thermal shorts in the location of the opening either
during calibration or during subsequent installation of the Single-
Packaged Dedicated System. A calibration test shall be made for air
movements comparable to those expected for Single-Packaged Dedicated
System capacity measurement, i.e., with air volume flow rate within
10 percent of the air volume flow rate of the Single-Packaged
Dedicated System evaporator.
3.5.2.10.2.13 The heat input shall be adjusted to maintain an
average box temperature not less than 25.0 [deg]F above the test
enclosure temperature.
3.5.2.10.2.14 The average dry-bulb temperature inside the
calibrated box shall not vary more than 1.0 [deg]F over the course
of the calibration test.
3.5.2.10.2.15 A calibration test shall be the average of 11
consecutive hourly readings when the box has reached a steady-state
temperature condition.
3.5.2.10.2.16 The box temperature shall be the average of all
readings after a steady-state temperature condition has been
reached.
3.5.2.10.2.17 The calibrated box has reached a steady-state
temperature condition when: The average box temperature is not less
than 25 [deg]F above the test enclosure temperature. Temperature
variations do not exceed 5.0 [deg]F between temperature measuring
stations. Temperatures do not vary by more than 2 [deg]F at any one
temperature- measuring station.
3.5.2.10.2.18 Data to be Measured and Recorded. Refer to Table
C5 in section C6.2 of AHRI 1250-2020 for the required data that need
to measured and recorded.
3.5.2.10.2.19 Refrigeration Capacity Calculation.
The heat leakage coefficient of the calibrated box is calculated
by
[GRAPHIC] [TIFF OMITTED] TR04MY23.080
For each Dry Rating Condition, calculate the Net Capacity:
qss = Kcb (Ten-Tcb) + 3.412 x Ec
3.5.2.10.3 Detachable single-packaged systems shall be tested as
single-packaged dedicated refrigeration systems.
3.5.2.11 Variable-Capacity and Multiple-Capacity Dedicated
Condensing Refrigeration Systems
3.5.2.11.1 Manufacturer-Provided Equipment Overrides
Where needed, the manufacturer must provide a means for
overriding the controls of the test unit so that the compressor(s)
operates at the specified speed or capacity and the indoor blower
operates at the speed consistent with the compressor operating level
as would occur without override.
3.5.2.11.2 Compressor Operating Levels
For variable-capacity and multiple-capacity compressor systems,
the minimum capacity for testing shall be the minimum capacity that
the system control would operate the compressor in normal operation.
Likewise, the maximum capacity for testing shall be the maximum
capacity that the system control would operate the compressor in
normal operation. For variable-speed compressor systems, the
intermediate speed for testing shall be the average of the minimum
and maximum speeds. For digital compressor systems, the intermediate
duty cycle shall be the average of the minimum and maximum duty
cycles. For multiple-capacity compressor systems with three capacity
levels, the intermediate operating level for testing shall be the
middle capacity level. For multiple-capacity compressor systems with
more than three capacity levels, the intermediate operating level
for testing shall be the level whose displacement ratio is closest
to the average of the maximum and minimum displacement ratios.
3.5.2.11.3 Refrigeration Systems with Digital Compressor(s)
Use the test methods described in section 3.5.2.10.1 of this
appendix as the secondary method of test for refrigeration systems
with digital compressor(s) with modifications as described in this
section. The Test Operating tolerance for refrigerant mass flow rate
and suction pressure in Table 2 of AHRI 1250-2020 shall be ignored.
Temperature and pressure measurements used to calculate shall be
recorded at a frequency of once per second or faster and based on
average values measured over the 30-minute test period.
3.5.2.11.3.1 For Matched pair (not including single-packaged
systems) and Dedicated Condensing Unit refrigeration systems, the
preliminary test in sections 3.5.2.10.1.2 and 3.5.2.10.1.3 of this
appendix is not required. The liquid line and suction line shall be
25 feet 3 inches, not including the requisite flow
meters. Also, the term in the equation to calculate net capacity
shall be set equal to zero.
3.5.2.11.3.2 For Dedicated Condensing Unit refrigeration
systems, the primary capacity measurement method shall be balanced
ambient outdoor calorimeter, outdoor air enthalpy, or outdoor room
calorimeter.
[FR Doc. 2023-08128 Filed 5-3-23; 8:45 am]
BILLING CODE 6450-01-P
