Energy Conservation Program: Test Procedure for Dehumidifying Direct Expansion-Dedicated Outdoor Air Systems, 36018-36060 [2021-13773]
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Federal Register / Vol. 86, No. 127 / Wednesday, July 7, 2021 / Proposed Rules
DEPARTMENT OF ENERGY
10 CFR Parts 429 and 431
[EERE–2017–BT–TP–0018]
RIN 1904–AD93
Energy Conservation Program: Test
Procedure for Dehumidifying Direct
Expansion-Dedicated Outdoor Air
Systems
Office of Energy Efficiency and
Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking
and request for comment.
AGENCY:
The U.S. Department of
Energy (DOE) is proposing to establish
definitions for ‘‘direct expansiondedicated outdoor air systems’’ (DX–
DOAS or DX–DOASes) and
‘‘dehumidifying direct expansiondedicated outdoor air systems’’ (DDX–
DOAS or DDX–DOASes). DX–DOASes
are a category of small, large, and very
large commercial package air
conditioning and heating equipment
under the Energy Policy and
Conservation Act (EPCA), as amended.
In addition, DOE is proposing to
establish a test procedure to measure the
energy efficiency of DDX–DOASes,
which aligns with the most recent
version of the relevant industry
consensus test standards for DDX–
DOASes, with certain minor
modifications. Lastly, DOE is proposing
to add supporting definitions, energy
efficiency metrics for dehumidification
and heating modes, and provisions
governing public representations as part
of this rulemaking. DOE welcomes
written comment from the public on any
subject within the scope of this
document (including topics not
specifically raised in this proposal), as
well as the submission of data and other
relevant information.
DATES: Comments: DOE will accept
written comments, data, and
information regarding this notice of
proposed rulemaking (NOPR) on or
before September 7, 2021. See section V,
‘‘Public Participation,’’ for details.
Meeting: DOE will hold a webinar on
Monday, August 2, 2021 from 10:00 a.m.
to 4:00 p.m. See section V, ‘‘Public
Participation,’’ for webinar registration
information, participant instructions,
and information about the capabilities
available to webinar participants.
ADDRESSES: Interested persons are
encouraged to submit comments using
the Federal eRulemaking Portal at
www.regulations.gov. Follow the
instructions for submitting comments.
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SUMMARY:
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Alternatively, interested persons may
submit comments, identified by docket
number EERE–2017–BT–TP–0018, by
any of the following methods:
1. Federal eRulemaking Portal:
www.regulations.gov.
2. Email: to CommACHeatingEquip
Cat2017TP0018@ee.doe.gov. Include
docket number EERE–2017–BT–TP–
0018 in the subject line of the message.
No telefacsimiles (faxes) will be
accepted. For detailed instructions on
submitting comments and additional
information on this process, see section
V of this document (Public
Participation).
Although DOE has routinely accepted
public comment submissions through a
variety of mechanisms, including postal
mail and hand delivery/courier, the
Department has found it necessary to
make temporary modifications to the
comment submission process in light of
the ongoing Covid–19 pandemic. DOE is
currently accepting only electronic
submissions at this time. If a commenter
finds that this change poses an undue
hardship, please contact Appliance
Standards Program staff at (202) 586–
1445 to discuss the need for alternative
arrangements. Once the Covid–19
pandemic health emergency is resolved,
DOE anticipates resuming all of its
regular options for public comment
submission, including postal mail and
hand delivery/courier.
Docket: The docket, which includes
Federal Register notices, public
meeting/webinar 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,
some documents listed in the index,
such as those containing information
that is exempt from public disclosure,
may not be publicly available.
The docket web page can be found at:
www.regulations.gov/
#docketDetail;D=EERE-2017-BT-TP0018. The docket web page contains
instructions on how to access all
documents, including public comments,
in the docket. See section V (Public
Participation) for information on how to
submit comments through
www.regulations.gov.
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.
FOR FURTHER INFORMATION CONTACT:
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Mr. Eric Stas, U.S. Department of
Energy, Office of the General Counsel,
GC–33, 1000 Independence Avenue SW,
Washington, DC 20585. Telephone:
(202) 586–5827. Email: Eric.Stas@
hq.doe.gov.
For further information on how to
submit a comment, review other public
comments and the docket, or participate
in the webinar, contact the Appliance
and Equipment Standards Program staff
at (202) 287–1445 or by email:
ApplianceStandardsQuestions@
ee.doe.gov.
DOE
proposes to incorporate by reference the
following industry standards into title
10 of the Code of Federal Regulations
(CFR) part 431:
Air-Conditioning, Heating, and
Refrigeration Institute (AHRI)
Standard 920–2020 (I–P), ‘‘2020
Standard for Performance Rating of
Direct Expansion-Dedicated Outdoor
Air System Units,’’ approved
February 4, 2020.
American National Standards Institute
(ANSI)/AHRI Standard 1060–2018,
‘‘2018 Standard for Performance
Rating of Air-to-Air Exchangers for
Energy Recovery Ventilation
Equipment,’’ approved 2018.
Copies of AHRI Standard 920–2020
(I–P), and ANSI/AHRI Standard 1060–
2018 can be obtained from the Airconditioning, Heating, and Refrigeration
Institute, 2311 Wilson Blvd., Suite 400,
Arlington, VA 22201, (703) 524–8800, or
online at: www.ahrinet.org.
ANSI/American Society of Heating,
Refrigerating and Air-Conditioning
Engineers (ASHRAE) Standard 37–
2009, ‘‘Methods of Testing for Rating
Electrically Driven Unitary AirConditioning and Heat Pump
Equipment,’’ ASHRAE approved June
24, 2009.
ANSI/ASHRAE Standard 41.1–2013,
‘‘Standard Method for Temperature
Measurement,’’ ANSI approved
January 30, 2013.
ANSI/ASHRAE Standard 41.6–2014,
‘‘Standard Method for Humidity
Measurement,’’ ANSI approved July 3,
2014.
ANSI/ASHRAE Standard 198–2013,
‘‘Method of Test for Rating DXDedicated Outdoor Air Systems for
Moisture Removal Capacity and
Moisture Removal Efficiency,’’ ANSI
approved January 30, 2013.
Copies of ANSI/ASHRAE Standard
37–2009, ANSI/ASHRAE Standard
41.1–2013, ANSI/ASHRAE Standard
41.6–2014, and ANSI/ASHRAE
Standard 198–2013 can be obtained
from the American Society of Heating,
SUPPLEMENTARY INFORMATION:
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Refrigerating and Air-Conditioning
Engineers, 180 Technology Parkway,
Peachtree Corners, GA 30092, (404)
636–8400, or online at: www.ashrae.org.
See section IV.M of this document for
a further discussion of these standards.
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Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Notice of Proposed
Rulemaking
III. Discussion
A. Scope of Applicability
1. Equipment Coverage
2. Scope of Test Procedure
3. Capacity Limit
4. Industry Terminology
B. Test Procedure for Dehumidifying
Dedicated Outdoor Air Systems
1. Industry Consensus Test Standards
2. Efficiency Metrics
a. Dehumidification Metric
b. Heating Metric
c. ISMRE2 and ISCOP2 Weighting Factors
3. Test Method
a. Definitions
b. Break-In Period
c. Airflow-Measuring Apparatus
d. Test Operating Conditions
i. Target Supply and Return Airflow Rates
ii. Units With Cycle Reheat Functions
iii. Target Supply Air Dry-Bulb
Temperature
iv. Target Supply Air Dew-Point
Temperature
v. Units With Staged Capacity Control
e. Water-Cooled and Water-Source Heat
Pump DX–DOAS Equipment
i. Test Conditions for Multiple-Inlet Water
Sources
ii. Condenser Liquid Flow Rate
iii. Water Pump Effect
iv. Energy Consumption of Heat Rejection
Fans and Chillers
v. Chilled Water Coil Exclusion
f. Defrost Energy Use for Air-Source Heat
Pump
g. General Control Setting Requirements
h. Ventilation Energy Recovery Systems
i. Exhaust Air Transfer and Leakage
ii. Purge Angle Setting
iii. Return Air External Static Pressure
Requirements
iv. Target Return Airflow Rate
i. Demand-Controlled Ventilation
j. Tolerances for Supply and Return
Airflow and External Static Pressure
k. Secondary Dehumidification and
Heating Capacity Tests
l. Corrections
i. Calculation of the Degradation
Coefficient
ii. Non-Standard Low-Static Motor
iii. Calculation of Supplementary Heat
Penalty
4. Determination of Represented Values
a. Basic Model
b. Sampling Plan Requirements
c. Multiple Refrigerants
d. Alternative Energy-Efficiency
Determination Methods
e. Rounding
5. Configuration of Unit Under Test
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C. Other Comments
D. Test Procedure Costs, Harmonization,
and Other Topics
1. Test Procedure Costs and Impact
2. Harmonization With Industry Standards
3. Other Test Procedure Topics
E. Compliance Date
IV. Procedural Issues and Regulatory
Review
A. Review Under Executive Order 12866
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. Description of Materials Incorporated
by Reference
V. Public Participation
A. Participation in the Webinar
B. Procedure for Submitting Prepared
General Statements for Distribution
C. Conduct of the Webinar
D. Submission of Comments
E. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary
I. Authority and Background
Small, large, and very large
commercial package air conditioning
and heating equipment are included in
the list of ‘‘covered equipment’’ for
which DOE is authorized to establish
and amend energy conservation
standards and test procedures. (42
U.S.C. 6311(1)(B)–(D)) As defined by the
Energy Policy and Conservation Act, as
amended (EPCA), ‘‘commercial package
air conditioning and heating
equipment’’ means air-cooled, watercooled, evaporatively-cooled, or watersource (not including ground-watersource) electrically operated, unitary
central air conditioners and central air
conditioning heat pumps for
commercial application. (42 U.S.C.
6311(8)(A)) Industry standards generally
describe unitary central air conditioning
equipment as one or more factory-made
assemblies that normally include an
evaporator or cooling coil and a
compressor and condenser combination.
Units equipped to also perform a
heating function are included as well.1
Direct expansion-dedicated outdoor air
systems (DX–DOASes) provide
1 See American Society of Heating, Refrigerating
and Air-Conditioning Engineers (ASHRAE)
Standard 90.1, ‘‘Energy Standard for Buildings
Except Low-Rise Residential Buildings.’’
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conditioning of outdoor ventilation air
using a refrigeration cycle consisting of
a compressor, condenser, expansion
valve, and evaporator,2 and therefore,
DOE has initially concluded that DX–
DOASes are a category of commercial
package air conditioning and heating
equipment subject to EPCA. An industry
consensus test standard has been
established for a subset of DX–DOASes
(i.e., dehumidifying DX–DOASes (DDX–
DOASes)), which are the subject of this
test procedure proposal. The following
sections discuss DOE’s authority to
establish test procedures for DDX–
DOASes, as well as relevant background
information regarding DOE’s proposed
adoption of the industry consensus test
standard, and proposed clarifications to
the industry test procedure for this
equipment.
A. Authority
EPCA,3 as amended, among other
things, authorizes DOE to regulate the
energy efficiency of a number of
consumer products and certain
industrial equipment. Title III, Part C 4
of EPCA, Public Law 94–163 (42 U.S.C.
6311–6317, as codified), added by
Public Law 95–619, Title IV, § 441(a),
established the Energy Conservation
Program for Certain Industrial
Equipment, which sets forth a variety of
provisions designed to improve energy
efficiency. This covered equipment
includes small, large, and very large
commercial package air conditioning
and heating equipment. (42 U.S.C.
6311(1)(B)–(D)) DOE has initially
determined that commercial package air
conditioning and heating equipment
includes DX–DOASes. As discussed in
section I.B of this document, DX–
DOASes had not previously been
addressed in DOE rulemakings and are
not currently subject to Federal test
procedures or energy conservation
standards.
Under EPCA, DOE’s energy
conservation program consists
essentially of four parts: (1) Testing, (2)
labeling, (3) Federal energy conservation
standards, and (4) certification and
enforcement procedures. Relevant
provisions of EPCA specifically include
definitions (42 U.S.C. 6311), energy
conservation standards (42 U.S.C. 6313),
test procedures (42 U.S.C. 6314),
2 Other types of dedicated outdoor air systems are
available that do not utilize direct expansion (e.g.,
units that use chilled water, rather than refrigerant,
as the heat transfer medium); these are discussed
in section III.B.3.e.v. of this document.
3 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).
4 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
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labeling provisions (42 U.S.C. 6315),
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(b); 42 U.S.C. 6296), and (2)
making representations about the
efficiency of that equipment (42 U.S.C.
6314(d)). Similarly, DOE uses these test
procedures to determine whether the
equipment complies with relevant
standards promulgated under EPCA.
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 (b); 42 U.S.C. 6297) DOE
may, however, grant waivers of Federal
preemption in limited circumstances 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, the statute also
sets forth the criteria and procedures
DOE is required to follow when
prescribing or amending test procedures
for covered equipment. Specifically,
EPCA requires that any test procedure
prescribed or amended shall be
reasonably designed to produce test
results which measure energy
efficiency, energy use, or estimated
annual operating cost of covered
equipment during a representative
average use cycle and requires that test
procedures not be unduly burdensome
to conduct. (42 U.S.C. 6314(a)(2))
EPCA requires that the test
procedures for commercial package air
conditioning and heating equipment be
those generally accepted industry
testing procedures or rating procedures
developed or recognized by the AirConditioning, Heating, and Refrigeration
Institute (AHRI) or by the American
Society of Heating, Refrigerating and
Air-Conditioning Engineers (ASHRAE),
as referenced in ASHRAE Standard
90.1, ‘‘Energy Standard for Buildings
Except Low-Rise Residential Buildings’’
(ASHRAE Standard 90.1). (42 U.S.C.
6314(a)(4)(A)) Further, if such an
industry test procedure is amended,
DOE must update its test procedure to
be consistent with the amended
industry test procedure, unless DOE
determines, by rule published in the
Federal Register and supported by clear
and convincing evidence, that such
amended test procedure would not meet
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the requirements in 42 U.S.C. 6314(a)(2)
and (3), related to representative use
and test burden. (42 U.S.C.
6314(a)(4)(B))
EPCA also requires that, at least once
every seven years, DOE evaluate test
procedures for each type of covered
equipment, including commercial
package air conditioning and heating
equipment to determine whether
amended test procedures would more
accurately or fully comply with the
requirements for the test procedures not
to 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)–(3)) In
addition, if DOE determines that a test
procedure amendment is warranted, it
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
in the Federal Register its
determination not to amend the test
procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
As discussed in section I.B of this
document, a test procedure for a subset
of DX–DOASes (i.e., DDX–DOASes),
was first specified by ASHRAE Standard
90.1 in the 2016 edition (ASHRAE
Standard 90.1–2016). Pursuant to 42
U.S.C. 6314(a)(4)(B), and following
updates to the relevant test procedures
which were referenced in ASHRAE
Standard 90.1, DOE is publishing this
NOPR proposing to establish a test
procedure for DDX–DOASes in
satisfaction of its aforementioned
obligations under EPCA.
B. Background
From a functional perspective, DX–
DOASes operate similarly to other
categories of commercial package air
conditioning and heat pump equipment,
in that they provide conditioning using
a refrigeration cycle consisting of a
compressor, condenser, expansion
valve, and evaporator. DX–DOASes
provide ventilation and conditioning of
100-percent outdoor air to the
conditioned space, whereas for typical
commercial package air conditioners
that are central air conditioners, outdoor
air makes up only a small portion of the
total airflow (usually less than 50
percent). DX–DOASes are typically
installed in addition to a local, primary
cooling or heating system (e.g.,
commercial unitary air conditioner,
variable refrigerant flow system, chilled
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water system, water-source heat
pumps)—the DX–DOAS conditions the
outdoor ventilation air, while the
primary system provides cooling or
heating to balance building shell and
interior loads and solar heat gain.
According to ASHRAE, a well-designed
system using a DX–DOAS can ventilate
a building at lower installed cost,
reduce overall annual building energy
use, and improve indoor environmental
quality.5
On October 26, 2016, ASHRAE
published ASHRAE Standard 90.1–
2016, which for the first time specified
a test standard and efficiency standards
for DX–DOASes. ASHRAE Standard
90.1–2016 (and the subsequent 2019
edition) defines DX–DOAS as a type of
air-cooled, water-cooled, or watersource factory assembled product that
dehumidifies 100% outdoor air to a low
dew point and includes reheat that is
capable of controlling the supply drybulb temperature of the dehumidified
air to the designed supply air
temperature. This conditioned outdoor
air is then delivered directly or
indirectly to the conditioned spaces. It
may precondition outdoor air by
containing an enthalpy wheel, sensible
wheel, desiccant wheel, plate heat
exchanger, heat pipes, or other heat or
mass transfer apparatus.
Although ASHRAE Standard 90.1–
2016 uses the term ‘‘DX–DOAS,’’ the
definition of this term provided therein
describes a subset of DX–DOASes,
specifically DDX–DOASes. The
ASHRAE definition of ‘‘DX–DOAS’’ is
generally equivalent to the equipment
DOE is proposing to define as DDX–
DOAS and for which DOE is proposing
to adopt the industry consensus
standard. DDX–DOASes dehumidify air
to a low dew point. When operating in
humid conditions, the dehumidification
load from the outdoor ventilation air is
a much larger percentage of the total
cooling load for a DDX–DOAS than for
a typical commercial air conditioner.
Additionally, compared to a typical
commercial air conditioner, the amount
of total cooling (both sensible and
latent) is much greater per pound of air
for a DDX–DOAS at design conditions
(i.e., the warmest/most humid expected
summer conditions), and a DDX–DOAS
is designed to accommodate greater
variation in entering air temperature
and humidity (i.e., a typical commercial
air conditioner would not be able to
dehumidify 100-percent outdoor
ventilation air to the levels achieved by
5 From the June 2018 ASHRAE eSociety
Newsletter (Available at: www.ashrae.org/news/
esociety/what-s-new-in-doas-and-refrigerantresearch) (Last accessed May 24, 2021).
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a DDX–DOAS). Not all DX–DOASes
have this dehumidification capability,
which is why DOE is proposing a
separate definition. (See section III.B.2.a
of this NOPR for further details.)
The amendment to ASHRAE Standard
90.1 to specify an industry test standard
for equipment that DOE calls DDX–
DOAS triggered DOE’s obligations vis-a`vis test procedures under 42 U.S.C.
6314(a)(4)(B), as outlined previously.
On July 25, 2017, DOE published a
request for information (RFI) (the July
2017 ASHRAE TP RFI) in the Federal
Register to collect information and data
to consider new and amended DOE test
procedures for commercial package air
conditioning and heating equipment,
given the test procedure updates
included in ASHRAE Standard 90.1–
2016. 82 FR 34427. As part of the July
2017 ASHRAE TP RFI, DOE requested
comment on several aspects regarding
test procedures for DDX–DOASes in
consideration of adopting a new DOE
test procedure for this equipment,
including: Incorporation by reference of
the relevant industry test standard(s);
efficiency metrics and calculations, and
additional topics that may inform DOE’s
decisions in a future test procedure
rulemaking.6 82 FR 34427, 34435–34439
(July 25, 2017). On October 25, 2019,
ASHRAE published an updated version
of ASHRAE Standard 90.1 (i.e.,
ASHRAE Standards 90.1–2019), which
36021
maintained the DDX–DOAS provisions
as first introduced in ASHRAE Standard
90.1–2016 without revisions.
DOE received a number of comments
from interested parties in response to
the July 2017 ASHRAE TP RFI, which
covered multiple categories of
equipment. Table I–1 lists the
commenters relevant to DDX–DOASes,
along with each commenter’s
abbreviated name used throughout this
NOPR. DOE considered these comments
in the preparation of this NOPR.
Discussion of the relevant comments,
and DOE’s responses, are provided in
the appropriate sections of this
document.
TABLE I–1—INTERESTED PARTIES PROVIDING DX–DOAS-RELATED COMMENTS ON THE JULY 2017 ASHRAE TEST
PROCEDURE RFI
Type 1
Name
Abbreviation
Air-Conditioning, Heating, and Refrigeration Institute .............................................................................
Appliance Standards Awareness Project (ASAP), Alliance to Save Energy (ASE), American Council
for an Energy-Efficient Economy (ACEEE), Northwest Energy Efficiency Alliance (NEEA), and
Northwest Power and Conservation Council (NPCC).
Carrier Corporation, part of United Technologies Climate, Controls & Security (CCS) business ..........
Goodman Global, Inc ..............................................................................................................................
The Greenheck Group .............................................................................................................................
Ingersoll Rand .........................................................................................................................................
Lennox International, Inc .........................................................................................................................
Mitsubishi Electric Cooling & Heating 2 ...................................................................................................
National Comfort Institute ........................................................................................................................
Pacific Gas and Electric Company (PG&E), Southern California Gas Company (SoCalGas), San
Diego Gas and Electric (SDG&E), and Southern California Edison (SCE), collectively referred to
as California Investor-Owned Utilities (CA IOUs).
AHRI ............................................
Joint Advocates ...........................
IR
EA
Carrier .........................................
Goodman .....................................
Greenheck ...................................
Ingersoll Rand .............................
Lennox .........................................
Mitsubishi ....................................
NCI ..............................................
CA IOUs ......................................
M
M
M
M
M
M
IR
U
1 EA:
Efficiency/Environmental Advocate; IR: Industry Representative; M: Manufacturer; U: Utility.
commented that it fully supports all of the comments submitted by AHRI on DX–DOAS issues.
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2 Mitsubishi
On February 14, 2020, DOE published
a final rule updating its procedures for
consideration of new and amended
energy conservation standards at 10 CFR
part 430, subpart C, appendix A,
‘‘Procedures, Interpretations, and
Policies for Consideration of New or
Revised Energy Conservation Standards
and Test Procedures for Consumer
Products and Certain Commercial/
Industrial Equipment’’ (the Process
Rule). 85 FR 8626. As part of the update,
the Process Rule now applies explicitly
to commercial and industrial
equipment. 10 CFR 431.4. The updated
Process Rule also includes provisions
specific to the consideration of new and
amended energy conservation standards
and test procedures for covered
equipment subject to the ASHRAE
provisions of EPCA. See Process Rule,
10 CFR part 430, subpart C, appendix A,
sections 2 and 9.
With respect to DOE’s consideration
of changes to the relevant industry
consensus test procedure(s) for covered
ASHRAE equipment, the Process Rule
now provides that DOE will do so only
if it can meet a very high bar to
demonstrate the ‘‘clear and convincing
evidence’’ threshold. 10 CFR part 430,
subpart C, appendix A, section 9(b).
Clear and convincing evidence would
exist only where the specific facts and
data made available to DOE regarding a
particular ASHRAE amendment
demonstrates that there is no substantial
doubt that that the industry test
procedure does not meet the EPCA
requirements. Id. DOE will make this
determination only after seeking data
and information from interested parties
and the public to help inform DOE’s
views. DOE will seek from interested
stakeholders and the public data and
information to assist in making this
determination, prior to publishing a
proposed rule to adopt a different test
procedure. Id.
II. Synopsis of the Notice of Proposed
Rulemaking
In this NOPR, DOE is proposing to
establish a definition for DX–DOAS as
a category of commercial package air
conditioning and heating equipment
and adopt a new test procedure for a
subset of DX–DOASes (i.e., DDX–
DOASes), consistent with the industry
consensus test standard as specified in
ASHRAE Standard 90.1–2019. The
proposed test procedure applies to all
DDX–DOASes for which ASHRAE 90.1–
2019 specifies standards, with the
exception of ground-water-source DDX–
DOASes, as discussed in section III.A.1
of this NOPR. More specifically, DOE
proposes to update 10 CFR 431.96,
‘‘Uniform test method for the
measurement of energy efficiency of
commercial air conditioners and heat
pumps,’’ to adopt a new test procedure
for DDX–DOASes as follows: (1)
Incorporate by reference AHRI Standard
920–2020 (I–P), ‘‘Performance Rating of
6 In the July 2017 ASHRAE TP RFI, DOE referred
to DDX–DOASes simply as ‘‘DOASes.’’
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Direct Expansion-Dedicated Outdoor
Air System Units’’ (AHRI 920–2020), the
most recent version of the test
procedure recognized by ASHRAE
Standard 90.1 for DDX–DOASes, and
the relevant industry standards
referenced therein; (2) establish the
scope of coverage for the DDX–DOAS
test procedure; (3) add definitions for
DX–DOASes and DDX–DOASes, as well
as additional terminology required by
the test procedure; (4) adopt the
integrated seasonal moisture removal
efficiency, as measured according to the
most recent applicable industry
standard (ISMRE2), and integrated
seasonal coefficient of performance
(ISCOP2), as measured according to the
most recent applicable industry
standard, as energy efficiency
descriptors for dehumidification and
heating mode, respectively; and (5)
establish representation requirements.
DOE proposes to add a new Appendix
B to Subpart F of Part 431, titled
‘‘Uniform test method for measuring the
energy consumption of dehumidifying
direct expansion-dedicated outdoor air
systems,’’ (Appendix B) that would
include the new test procedure
requirements for DDX–DOASes. In
conjunction, DOE proposes to amend
Table 1 in 10 CFR 431.96 to identify the
newly added Appendix B as the
applicable test procedure for testing
DDX–DOASes. DOE has tentatively
determined that the proposed test
procedure would not be unduly
burdensome to conduct.
DOE’s proposed actions are
summarized in Table II.1 and addressed
in detail in section III of this document.
TABLE II.1—SUMMARY OF PROPOSED TEST PROCEDURE FOR DDX–DOASES
Proposed test procedure
Attribution
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Incorporates by reference AHRI 920–2020 and other relevant industry test standards referenced by that
standard. AHRI 920–2020 includes:
—test methods for DDX–DOAS with and without ventilation energy recovery systems (VERS);
—test operating conditions, including Standard Rating Conditions, simulated ventilation air conditions
for optional test methods for DDX–DOASes with VERS, supply air target conditions, supply and return airflow rates, and external static pressure;
—testing instrumentation and apparatus instructions;
—test operating and condition tolerances 7;
—a list of components that must be present for testing; and
—provisions for testing units with certain optional features.
Defines DX–DOASes as covered equipment which meet the EPCA definition for small, large, or very-large
commercial package air conditioning and heating equipment.
Defines the scope of coverage of the test procedure, including defining DDX–DOASes to distinguish them
from other kinds of equipment and a capacity limit based on moisture removal capacity (MRC).
Adopts ISMRE2 and ISCOP2 as the seasonal efficiency descriptors for dehumidification and heating mode,
respectively, as specified in AHRI 920–2020.
Provides minor corrections and additional instruction consistent with AHRI 920–2020 by:
—specifying the external head pressure requirements for DDX–DOASes with integral water pumps;
—specifying general control setting requirements;
—correcting a typographical error in the calculation of the degradation coefficient; and
—providing a missing definition necessary for the interpretation of the airflow setting instructions.
Specifies representation requirements, including a basic model definition, sampling plan requirements, and
use of alternative energy-efficiency determination methods (AEDMs).
III. Discussion
The following sections discuss DOE’s
proposal to define DX–DOASes as a
category of small, large and extra-large
commercial package air conditioning
and heating equipment and to adopt a
new test procedure for DDX–DOASes, a
subset of DX–DOASes, and address
relevant comments received in response
to specific issues DOE raised in the July
2017 ASHRAE TP RFI. Commenters’
references to ‘‘DX–DOASes’’ or
‘‘DOASes’’ have been changed to ‘‘DDX–
DOASes’’ where DOE understands the
commenters to be specifically
discussing DX–DOASes that would
meet the dehumidification performance
criterion as proposed.
7 ‘‘Test operating tolerance’’ refers to the
maximum permissible range that a measurement
may vary over a specified test interval. ‘‘Test
condition tolerance’’ refers to the maximum
permissible difference between the average value of
the measured test parameter and the specified test
condition.
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A. Scope of Applicability
1. Equipment Coverage
As discussed, DOE has initially
determined that DX–DOASes are a
category of small, large, and very large
commercial package air conditioning
and heating equipment and, therefore,
are covered equipment under EPCA. (42
U.S.C. 6311(1)(B)–(D)) DX–DOASes
operate similarly to more typical
commercial package air conditioning
equipment in that they provide
conditioning of outdoor ventilation air
using a refrigeration cycle consisting of
a compressor, condenser, expansion
valve, and evaporator. However, DX–
DOASes are designed to provide
ventilation and conditioning of 100percent outdoor air, while outdoor air
makes up only a small portion of the
total airflow for typical commercial
package air conditioning and heating
equipment (e.g., usually less than 50
percent).
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Adopt industry test procedure.
Establish equipment coverage.
Clarify scope of test procedure.
Adopt industry test procedure.
Clarify instructions in the industry
test procedure.
Provide for representations of energy efficiency consistent with
other commercial air conditioner/
heat pump equipment.
As discussed further in section III.A.4
of this document, industry provides
several definitions for DX–DOASes, but
DOE notes that the industry definitions
for ‘‘DX–DOAS’’ specifically refer to the
DDX–DOASes that are covered by the
scope of those industry test standards,
which does not include nondehumidifying (i.e., sensible-only) DX–
DOASes that exist on the market.
In this NOPR, DOE is proposing to
define ‘‘direct expansion-dedicated
outdoor air system, or DX–DOAS,’’ as a
category of small, large, or very large
commercial package air conditioning
and heating equipment which is capable
of providing ventilation and
conditioning of 100-percent outdoor air
or marketed in materials (including but
not limited to, specification sheets,
insert sheets, and online materials) as
having such capability. This proposed
definition is based, in part, on the
definition in section 3.6 of AHRI 920–
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2020, as discussed in section III.A.4 of
this document.
The proposed definition of DX–DOAS
would include all air-cooled, air-source
heat pump, and water-cooled equipment
subcategories specified in ASHRAE
Standard 90.1. For water-source heat
pump equipment, ASHRAE Standard
90.1 includes three configurations—
ground-source, closed loop; groundwater-source; and water-source. The
EPCA definition for ‘‘commercial
package air conditioning and heating
equipment’’ specifically excludes
ground-water-source equipment (42
U.S.C. 6311(8)(A)), so in proposing to
define (at 10 CFR 431.92) DX–DOAS as
a category of small, large, or very large
commercial package air conditioning
and heating equipment, ground-watersource DX–DOASes would be excluded
from coverage under EPCA.
Issue–1: DOE requests comment on
the proposed definition for ‘‘direct
expansion-dedicated outdoor air
system.’’ DOE also requests comment on
any additional characteristics not yet
considered that could help to
distinguish DX–DOASes from other
commercial package air conditioning
and heating equipment.
2. Scope of Test Procedure
DOE is proposing to establish a test
procedure for a subset of DX–DOASes
(i.e., DDX–DOASes). When operating in
humid conditions, the dehumidification
load is a much larger percentage of the
total cooling load for a DDX–DOAS than
for a typical commercial package air
conditioning system. DDX–DOASes in
particular handle a significantly higher
amount of total cooling (both sensible
and latent) per pound of air at design
conditions (i.e., the warmest or most
humid expected summer conditions),
and a DDX–DOAS is designed to
accommodate greater variation in
entering air temperature and humidity,
because outdoor conditions can vary
much more than typical indoor
conditions. As discussed, not all DX–
DOASes are designed to dehumidify
outdoor air at the most humid expected
summer conditions to a level consistent
with comfortable indoor conditions,
such as a dew point temperature less
than 55 °F (e.g., sensible-only cooling 8
DX–DOASes). AHRI stated that sensibleonly 100-percent outdoor air units
should not be covered by ANSI/AHRI
920–2015 because they are not intended
to dehumidify the ventilation air.
(AHRI, No. 11 at pp. 10–11) 9
8 ‘‘Sensible cooling’’ refers to the process of
cooling air by reducing its dry bulb temperature
without changing its moisture content.
9 A notation in the form ‘‘AHRI, No. 11 at pp. 10–
11’’ identifies a written comment: (1) Made by
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Because DOE is aware of sensibleonly DX–DOASes, DOE aims to further
delineate those DX–DOASes that would
be subject to the proposed test
procedure (i.e., DDX–DOASes). Section
2.2 of AHRI 920–2020 explicitly
excludes ‘‘Sensible-only 100% Outdoor
Air Units’’ from the scope of its test
standard. Accordingly, DOE proposes to
define DDX–DOASes (the subject of this
proposed test procedure) in 10 CFR
431.92 as those DX–DOASes specifically
having the capability to dehumidify air
to a dew point of 55 °F when operating
under Standard Rating Condition A as
specified in Table 4 or Table 5 of AHRI
920–2020 with a barometric pressure of
29.92 in Hg. The 55 °F dew point is
specified in ANSI/AHRI 920–2015 and
AHRI 920–2020 as the maximum dew
point temperature for the supply air for
the dehumidification mode tests.10 This
maximum dew point temperature
requirement for DDX–DOASes provides
a key differentiator from other DX–
DOASes, which typically cannot
dehumidify 100-percent outdoor air to a
dew point this low. This element is
consistent with the definition in AHRI
920–2020.
AHRI 920–2020 does not specify at
what airflow the dehumidification
element is to be evaluated. DOE
proposes to include within the proposed
definition of DDX–DOAS that the DDX–
DOAS be capable of providing the
specified dehumidification capability
for any portion of the range of air flow
rates advertised in manufacturer
materials. This provision would provide
additional specificity to the definition
found in AHRI 920–2020 to account for
manufacturers that may specify a range
of airflows for a given model.
As proposed, the test procedure
would apply to DDX–DOASes within
the capacity limits as discussed in the
following section.
Issue–1: DOE requests comment on
the proposed definition for
‘‘dehumidifying direct expansiondedicated outdoor air system.’’
Specifically, DOE requests comment on
AHRI; (2) recorded in document number 11 that is
filed in the docket of this test procedure rulemaking
(Docket No. EERE–2017–BT–TP–0018) and
available for review at www.regulations.gov; and (3)
which appears on pages 10 through 11 of document
number 11.
10 AHRI 920–2020 acknowledges the influence of
barometric pressure on humidity ratio for the inlet
air conditions specified in terms of dry bulb and
wet bulb temperature, allowing an upward
adjustment of the maximum supply air dew point
temperature that must be achieved, such that the
moisture removal rate matches that which would
occur at standard barometric pressure when
supplying 55 °F dew-point supply air—this
maximum supply air dew point increases linearly
as barometric pressure decreases, up to 57.3 °F at
the minimum-allowed 13.7 psia test pressure.
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36023
the proposed criteria for distinguishing
a ‘‘dehumidifying direct expansiondedicated outdoor air system’’ from a
‘‘direct expansion-dedicated outdoor air
system’’ more generally. DOE also
requests comment on any additional
characteristics not yet considered that
could help to distinguish DDX–DOASes
from DX–DOASes more generally.
3. Capacity Limit
As stated, EPCA defines as covered
equipment small, large, and very large
commercial package air conditioning
and heating equipment. (42 U.S.C.
6311(1)(B)–(D)) EPCA defines ‘‘small
commercial package air conditioning
and heating equipment’’ as commercial
package air conditioning and heating
equipment that is rated below 135,000
Btu per hour (cooling capacity). (42
U.S.C. 6311(8)(B)) The term ‘‘large
commercial package air conditioning
and heating equipment’’ means
commercial package air conditioning
and heating equipment that is rated—(i)
at or above 135,000 Btu per hour; and
(ii) below 240,000 Btu per hour (cooling
capacity). (42 U.S.C. 6311(8)(C)) The
term ‘‘very large commercial package air
conditioning and heating equipment’’
means commercial package air
conditioning and heating equipment
that is rated—(i) at or above 240,000 Btu
per hour; and (ii) below 760,000 Btu per
hour (cooling capacity). (42 U.S.C.
6311(8)(D))
In response to the July 2017 ASHRAE
TP RFI, AHRI commented that DOE’s
regulations for DDX–DOASes should be
capped at a reasonable capacity, similar
to the 760,000 Btu/h limit for
commercial packaged air conditioning
equipment. AHRI stated that laboratory
limitations may limit testing using
ANSI/AHRI 920–2015 to 300 lbs. of
moisture per hour at Standard Rating
Condition A and to units not physically
larger than more typical commercial
package air conditioning and heating
equipment with a capacity of 760,000
Btu/h. The commenter also stated that
the market for these larger, typical
commercial package air conditioning
equipment and DDX–DOAS units (with
a capacity greater than 760,000 Btu/h, or
equivalent) is very small and
customized. AHRI stated that the
customization helps customers
minimize energy consumption for their
application. (AHRI, No. 11 at p. 20)
As discussed, DOE has tentatively
concluded that DX–DOASes meet the
EPCA definition for ‘‘commercial
package air conditioning and heating
equipment,’’ and, thus, are to be
considered as a category of that covered
equipment. (42 U.S.C. 6311(8)(A)) The
upper capacity limit of commercial
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package air conditioning subject to the
DOE test procedures is 760,000 Btu per
hour, based on the definition of ‘‘very
large commercial package air
conditioning and heating equipment.’’
(42 U.S.C. 6311(8)(D))
For DDX–DOASes specifically, AHRI
920–2020 does not provide a method for
determining capacity in terms of Btu per
hour, but instead, it specifies a
determination of capacity in terms of
moisture removal capacity (MRC). DOE
proposes to translate the upper capacity
for coverage of commercial package air
conditioning and heating units
established in EPCA (i.e., 760,000 Btu
per hour) from Btu per hour to MRC for
DDX–DOASes. Specifically, DOE is
proposing, consistent with section 6 of
AHRI 920–2020, to translate the upper
limit from Btu per hour to MRC of the
DDX–DOAS when delivering
dehumidified supply air at a 55 °F dew
point. Manufacturers would use their
tested value of MRC to determine if a
DDX–DOAS is subject to the test
procedure.
To translate Btu per hour to MRC,
DOE calculated the maximum airflow
that could be supplied at a 55 °F
dewpoint for Standard Rating Condition
A as specified in Table 4 and Table 5
of AHRI 920–2020 by cooling and
dehumidifying it with an evaporator
with a refrigeration capacity of 760,000
Btu per hour. DOE calculated this based
on air entering the evaporator at
Standard Rating Condition A (95 °F drybulb temperature and 78 °F wet-bulb
temperature) and air exiting the
evaporator at 55 °F dew point and 95percent relative humidity at a standard
barometric pressure of 29.92 in Hg. DOE
then calculated the MRC that
corresponds to those conditions. Based
on these calculations, DOE is proposing
to limit the scope of this proposed test
procedure to DDX–DOAS units with a
MRC less than 324 lbs. per hour based
on Standard Rating Condition A as
specified in Table 4 or Table 5 of AHRI
920–2020.
Issue–2: DOE seeks comment on its
translation of Btu per hour to MRC and
specifically its proposal to translate the
upper capacity limit for DDX–DOASes
such that a model would be considered
in scope if it has an MRC less than 324
lbs. per hour.
4. Industry Terminology
As stated, DOE is proposing
definitions for DX–DOAS and DDX–
DOAS following a review of industry
standards and consistent with the
applicability of the relevant industry
testing standard. Both ANSI/AHRI 920–
2015 and ANSI/ASHRAE 198–2013
include definitions for ‘‘DX-Dedicated
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Outdoor Air System Units.’’ Section 3.3
of ANSI/AHRI 920–2015 defines ‘‘DXDedicated Outdoor Air System Units’’ as
a type of air-cooled, water-cooled, or
water-source factory assembled product
which dehumidifies 100-percent
outdoor air to a low dew point, and
includes reheat that is capable of
controlling the supply dry-bulb
temperature of the dehumidified air to
the designed supply air 11 temperature.
This conditioned outdoor air is then
delivered directly or indirectly to the
conditioned space(s). It may precondition outdoor air by containing an
enthalpy wheel, sensible wheel,
desiccant wheel, plate heat exchanger,
heat pipes, or other heat or mass transfer
apparatus. This is the same definition
used in ASHRAE Standard 90.1–2019.
Section 3 of ANSI/ASHRAE 198–2013
defines a ‘‘DX Dedicated Outdoor Air
Systems Unit (DX–DOAS)’’ as a type of
air-cooled, water-cooled, or watersource factory-assembled product that is
capable of dehumidifying 100-percent
outdoor air to a low dew point and may
be capable of controlling the dry-bulb
temperature of the dehumidified air to
the designed supply air temperature.
This conditioned outdoor air may be
delivered directly or indirectly to the
conditioned space(s). It may precondition outdoor air prior to direct
expansion cooling by incorporating an
enthalpy wheel, sensible wheel,
desiccant wheel, plate heat exchanger,
heat pipes, or other heat or mass transfer
apparatus. The product may also
include a supplementary heating system
for use when outdoor air requires
heating beyond the capability of the
refrigeration system and/or other heat
transfer apparatus.
As part of the July 2017 ASHRAE TP
RFI, DOE requested comment on certain
aspects of these two industry definitions
of dedicated outdoor air systems. 82 FR
34427, 34435–34436 (July 25, 2017). On
February 4, 2020, AHRI published AHRI
920–2020, which made changes to the
definition of ‘‘Dedicated Outdoor Air
System Unit’’ as compared to the
definition in ANSI/AHRI 920–2015 (and
ASHRAE Standard 90.1–2019). Section
3.6 of AHRI 920–2020 defines
‘‘Dedicated Outdoor Air System Unit’’
as a type of air-cooled, evaporativelycooled, or water-cooled air-conditioner,
or an air-source or water source heat
pump, that is a factory assembled
product designed and marketed and
sold to provide ventilation and
dehumidification of 100% outdoor air,
is capable of dehumidifying air to a
11 ‘‘Supply air’’ for a DDX–DOAS refers to
conditioned air that is supplied to the conditioned
space.
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55 °F dew point when operating under
Standard Rating Condition A as
specified in Table 4 or Table 5 of this
test standard with a barometric pressure
of 29.92 in Hg, and may include reheat.
It may include pre-conditioning of
outdoor air using an enthalpy wheel,
sensible wheel, desiccant wheel, plate
heat exchanger, heat pipes, or other heat
or mass transfer apparatus. Heating
components are optional and may
include electrical resistance, steam, hot
water, or gas heat. In addition, it may
provide for air cleaning or may include
mixing box or economizer dampers to
allow return air to be intermittently
used as allowed by the controls.
Both ANSI/AHRI 920–2015 and
ANSI/ASHRAE 198–2013 address
equipment that dehumidifies (or is
capable of dehumidifying) 100-percent
outdoor air to a low dew point. As
discussed, in its review of available
equipment, DOE found units marketed
as ‘‘dedicated outdoor air systems,’’ and
other units marketed for ‘‘100-percent
outdoor air’’ applications, both of which
can also operate with less than 100percent outdoor air. Such units have a
return air damper that allows
modulating the amount of return air that
is recirculated from the conditioned
space and mixed with the incoming
outdoor air before the mixed air is
conditioned. More typical commercial
package air conditioning equipment also
often incorporates a similar damper to
mix return air and outdoor air.
Additionally, like the industry
definitions for dedicated outdoor air
systems, which DOE notes would be
DDX–DOASes as that term is proposed
to be defined, some categories of
commercial package air conditioning
equipment can dehumidify 100-percent
outdoor air, although typically not to a
dew point as low as the industry
specification for DDX–DOASes.
As part of the July 2017 ASHRAE TP
RFI, DOE requested information on the
range of the maximum percentage of
return air intake relative to total airflow
of models of equipment that DOE
generally referred to as ‘‘DOASes’’ in
order to determine whether the
maximum return air percentage is an
important distinguishing feature of
DDX–DOASes. DOE also requested
information on the difference in
dehumidification capabilities of more
typical commercial package air
conditioning equipment and equipment
that DOE referred to as DOASes when
operating with 100-percent outdoor air.
82 FR 34427, 34435 (July 25, 2017).
Ingersoll Rand and Carrier
commented that there are not one or two
features or criteria that definitively
distinguish DDX–DOASes from more
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typical commercial package air
conditioning equipment. (Ingersoll
Rand, No. 12 at p. 2; Carrier, No. 6 at
p. 2) AHRI and Carrier commented that
there may be several potential
applications for DDX–DOASes, some of
which may not be 100-percent outdoor
air. (AHRI, No. 11 at p. 9; Carrier, No.
6 at p. 2) AHRI and Ingersoll Rand
stated, for example, that DDX–DOASes
may be supplied with recirculation
dampers that allow them to efficiently
dehumidify recirculated air when the
building is unoccupied. AHRI stated
that, as a result, it is not possible to
select a specific crossover percentage of
return air intake relative to total airflow
that would differentiate DDX–DOASes
from more typical commercial package
air conditioning equipment. (AHRI, No.
11 at p. 9; Ingersoll Rand, No. 12 at p.
2) Goodman supported AHRI’s position,
adding that when the return air intake
relative to the total airflow is less than
10–30 percent, ANSI/AHRI 920–2015 is
more appropriate than ANSI/AHRI 340/
360 12 in non-western climates.
(Goodman, No. 14 at p. 2)
As discussed, not all DX–DOASes are
designed to provide dehumidification
(to a low dew point) over larger
variation in entering air temperature
and humidity. As such, DOE is
proposing to define DDX–DOAS to
distinguish such equipment from DX–
DOAS more generally, as provided in
the previous sections. The DDX–DOAS
definition is consistent with the
definition in section 3.6 of AHRI 920–
2020 for the equipment subject to the
scope of that industry test standard.
DOE noted in the July 2017 ASHRAE
TP RFI that one difference between the
definitions in ANSI/ASHRAE 198–2013
and ANSI/AHRI 920–2015 (and now
AHRI 920–2020) is related to reheat.
ANSI/AHRI 920–2015 specifies that a
Direct Expansion-Dedicated Outdoor
Air System Unit includes reheat, which
is used to raise the temperature of
cooled and dehumidified air to a design
supply air temperature. The ANSI/
ASHRAE 198–2013 definition provides
that a DX Dedicated Outdoor Air
Systems Unit, as defined by that
industry standard, may have reheat but
does not require reheat. DOE requested
comment on whether and how reheating
functionality should be included in the
DDX–DOAS definition. 82 FR 34427,
34435–34436 (July 25, 2017).
In response to the July 2017 ASHRAE
TP RFI, AHRI and Greenheck
commented that while capturing reheat
12 ANSI/AHRI Standard 340/360, ‘‘Performance
Rating of Commercial and Industrial Unitary Airconditioning and Heat Pump Equipment’’
(Available at: www.ahrinet.org/) (Last accessed
April 19, 2021).
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performance in the test procedure for
DDX–DOAS equipment is an important
aspect to many installations, some
building HVAC designs incorporating
DDX–DOAS equipment operate without
any reheat capabilities. AHRI and
Greenheck suggested that the definition
of DDX–DOAS should not require
reheat, as it is important for owners and
designers to be able to select 100percent outdoor air units with varying
amounts of reheat or no reheat. (AHRI,
No. 11 at pp. 10–11, 20–21; Greenheck,
No. 13 at p. 2) AHRI further commented
that DDX–DOAS design and optimum
efficiency varies with climate and
application, and that the design is often
customized to accommodate the
different needs of different applications.
AHRI asserted that regulations must
allow for these differences to avoid
increasing energy consumption for a
given project. (AHRI, No. 11 at p. 20–
21) Greenheck commented that the
supplementary heat penalty included in
ANSI/AHRI 920–2015 unfairly
penalizes units without reheat, and
Greenheck suggested two options for
rating units without reheat. (Greenheck,
No. 13 at pp. 2–3). Carrier also
commented that reheat functionality is
an application issue and is not
applicable to the definition in a test
standard. (Carrier, No. 6 at p. 3)
DOE recognizes that the optimumefficiency DDX–DOAS design varies
with climate and application. DOE also
understands that the supplementary
heat penalty in ANSI/AHRI 920–2015 is
not representative of the way that units
without reheat are used in the field. As
is discussed in section III.B.2.a of this
document, as part of AHRI 920–2020,
AHRI modified the ISMRE metric to
remove the supplementary heat penalty
in recognition that some installation
conditions may not require reheating.
As is discussed in section III.B.1 of this
document, this metric was re-designated
in AHRI 920–2020 as ISMRE2. AHRI
920–2020 also includes a separate
application rating metric, ISMRE270, to
account for installations where
reheating is required. Moreover, the
updated definition in AHRI 920–2020
recognizes that there are units without
reheat. As such, DOE is not proposing
to include a reheat requirement in the
DX–DOAS or DDX–DOAS definition,
consistent with AHRI 920–2020.
Because of the difference in
terminology between the proposed DOE
test procedure and the relevant industry
standards, DOE proposes to include a
section 2.3(a) in its proposed Appendix
B indicating that the different
synonymous terms all refer to
dehumidifying direct expansion-
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36025
dedicated outdoor air system as defined
in 10 CFR 431.92.
Issue–3: DOE requests comment on its
proposal to clarify what terms are
synonymous with DDX–DOAS.
B. Test Procedure for Dehumidifying
Dedicated Outdoor Air Systems
Pursuant to EPCA, in response to the
DDX–DOAS-related updates to ASHRAE
90.1–2016 (maintained in ASHRAE
90.1–2019) and updates to the industry
test standard referenced in ASHRAE
90.1, DOE proposes to adopt a test
procedure for DDX–DOASes that
incorporates by reference the latest
applicable industry consensus test
standards.
In the following sections, DOE
presents analysis and discussion of
several test procedure issues and
proposes a test procedure for DDX–
DOASes. As discussed in more detail in
the following sections, DOE has initially
determined that the proposed test
procedure for DDX–DOASes would be
representative of an average use cycle
and not be unduly burdensome to
conduct.
DOE is adopting the generally
accepted industry testing procedures for
DDX–DOASes developed by AHRI (i.e.,
AHRI 920–2020) and referenced by
ASHRAE Standard 90.1, with the
following modifications as discussed in
this NOPR:
D Using the nomenclature DDX–
DOAS, rather than DX–DOAS, to define
the equipment subject to the test
procedure;
D Defining an upper limit of capacity
consistent with EPCA’s definition of
very large commercial package air
conditioning and heating equipment;
D Defining ‘‘non-standard low-static
fan motor,’’ in order to determine the
appropriate airflow setting procedure;
D Specifying the external head
pressure requirements for testing DDX–
DOASes with integral water pumps;
D Requiring that control settings
remain unchanged for all Standard
Rating Conditions once system set-up
has been completed prior to testing;
D Specifying requirements for testing
equipment available with multiple
refrigerant options; and
D Correcting a typographical error
within one of the equations.
1. Industry Consensus Test Standards
As first established in ASHRAE 90.1–
2016, ASHRAE Standard 90.1–2019
specifies separate equipment classes for
DDX–DOASes 13 and sets minimum
13 As discussed, the term DX–DOAS as defined by
ASHRAE 90.1–2019 is equivalent to the term DDX–
DOAS as defined by DOE in this NOPR.
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efficiency levels using the integrated
seasonal moisture removal efficiency
(ISMRE) metric for all DDX–DOAS
classes and also the integrated seasonal
coefficient of performance (ISCOP)
metric for air-source heat pump and
water-source heat pump DDX–DOAS
classes. ASHRAE Standard 90.1–2019
specifies that both metrics are to be
measured in accordance with ANSI/
AHRI Standard 920–2015, ‘‘Performance
Rating of DX-Dedicated Outdoor Air
System Units’’ (ANSI/AHRI 920–2015).
ANSI/AHRI 920–2015 specifies the
method for testing DDX–DOASes, in
part, through a reference to ANSI/
ASHRAE Standard 198–2013, ‘‘Method
of Test for Rating DX-Dedicated Outdoor
Air Systems for Moisture Removal
Capacity and Moisture Removal
Efficiency’’ (ANSI/ASHRAE 198–2013).
ANSI/AHRI 920–2015 specifies
Standard Rating Conditions (i.e.,
instructions on setting air and liquid
flow rates, and equations for calculating
ISMRE and ISCOP). Table 2 and Table
3 of ANSI/AHRI 920–2015 provide
outdoor and return air conditions for
four Standard Rating Conditions for the
dehumidification test and two Standard
Rating Conditions for the heating test for
heat pump DDX–DOASes. These tables
also provide condenser cooling water
temperatures (for both cooling tower
and chilled water condensers) for watercooled (cooling-only) DDX–DOASes and
water temperatures for water-source,
ground-source closed-loop, and groundwater source 14 heat pump DDX–
DOASes.
ANSI/ASHRAE 198–2013 includes
requirements on instrumentation, test
set-up, tolerances, method of test, and
calculations for moisture removal
capacity (MRC), moisture removal
efficiency (MRE), heating capacity (qhp)
and heating coefficient of performance
(COP). The MRE for the
dehumidification test is calculated for
Standard Rating Conditions 15 A, B, C,
and D of Table 2 or Table 3 of ANSI/
AHRI 920–2015 for air-cooled, watercooled, and water-source heat pump
14 As discussed in section III.A.1 of this NOPR,
the EPCA definition for ‘‘commercial package air
conditioning and heating equipment’’ specifically
excludes ground-water-source equipment (42 U.S.C.
6311(8)(A)). Accordingly, DOE is proposing to
exclude this equipment from the scope of
applicability of the test procedure.
15 Standard Rating Conditions in the AHRI 920
test procedure represent full-load and part-load
operating conditions for testing DX–DOASes.
Standard Rating Condition A represents full-load
operation in dehumidification mode, whereas
Standard Rating Conditions B–D represent part-load
operation in dehumidification mode. Standard
Rating Condition F represents full-load operation in
heat pump mode at low temperatures, and Standard
Rating Condition E represents full-load operation in
heat pump mode at high temperatures.
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DDX–DOASes. Similarly, COP is
calculated for the heating mode test for
Standard Rating Conditions E and F of
Table 2 or Table 3 of ANSI/AHRI 920–
2015 for heat pump DDX–DOASes. The
MRE and COP values are subsequently
used to calculate ISMRE and ISCOP
using weights that correspond to
temperature bin data for representative
cities in the United States.
DOE notes that AHRI recently revised
AHRI 920 and published an updated
version on February 4, 2020, AHRI
Standard 920–2020 (I–P), ‘‘Performance
Rating of Direct Expansion Dedicated
Outdoor Air System Units’’ (AHRI 920–
2020). AHRI 920–2020, which continues
to reference ANSI/ASHRAE 198–2013,
includes revisions that DOE has initially
determined improve the
representativeness, repeatability, and
reproducibility of the test methods
while also reducing test burden. These
revisions include, among other things,
the following: (1) Expanded scope of
coverage of the test procedure by no
longer imposing an upper limit of 97
lbs/hr on DDX–DOAS MRC, thereby
making the test procedure applicable to
all DDX–DOASes subject to standards
under ASHRAE Standard 90.1; (2)
revised outdoor air dry-bulb
temperature conditions, external static
pressures, humidity conditions, and
weighting factors for ISMRE and ISCOP,
which were redesignated as ISMRE2
and ISCOP2, respectively; (3) revised
calculations for achieving the target
supply air conditions for units with
staged capacity control; (4) added a
supplementary cooling penalty when
the supply air dry-bulb temperature is
greater than 75 °F in dehumidification
mode; (5) removed a supplementary
heat penalty for the efficiency metric
ISMRE2 when the supply air dry-bulb
temperature is less than 70 °F in
dehumidification mode; 16 (6) revised
condenser water conditions for watercooled and water-source heat pump
DDX–DOASes; (7) added requirements
for supply air dew point temperature; 17
(8) added requirements for outdoor coil
liquid flow rate; (9) provided additional
test unit, test facility, instrumentation,
16 As discussed in section III.B.3.a of this NOPR,
AHRI 920–2020 additionally provides a method for
calculating ISMRE270, an application metric for the
dehumidification efficiency with the inclusion of
the supplementary heat penalty. The subscript ‘‘70’’
indicates the inclusion of energy use from any
supplementary heat that is required to raise the
supply air dry bulb temperature to 70 °F.
17 Dew point is the temperature below which
water begins to condense from the water vapor state
in humid air into liquid water droplets. Dew point
varies with humidity (e.g., a low dew point
indicates low humidity and vice versa) and is,
therefore, used to specify the humidity of the
supply air.
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and apparatus set-up provisions; (10)
revised test methods for DDX–DOASes
equipped with VERS; (11) added
requirements for relief-air-cooled DDX–
DOASes and DDX–DOASes equipped
with desiccant wheels; and (12)
included requirements for secondary
capacity tests.
DOE carefully reviewed both ANSI/
AHRI 920–2015 and ANSI/ASHRAE
198–2013, as well as the latest changes
in AHRI 920–2020, in consideration of
this NOPR. In the following sections,
DOE discusses the proposed definition
for DDX–DOASes, scope of the test
procedure, efficiency metrics, test
methods (including the updates to AHRI
920 in the 2020 version listed in the
prior paragraph), and sampling
requirements. Generally, DOE
incorporates industry standards into the
regulations by reference to the standard.
In this NOPR, DOE has proposed to
incorporate by reference AHRI 920–
2020.
DOE is also proposing to incorporate
by reference several industry standards
that are referenced by AHRI 920–2020,
as shown in Table III–1.
TABLE III–1—ADDITIONAL INDUSTRY
STANDARDS PROPOSED TO BE INCORPORATED BY REFERENCE
Industry standard
ANSI/ASHRAE
2013.
ANSI/ASHRAE
2009.
ANSI/ASHRAE
2018.
ANSI/ASHRAE
2013.
ANSI/ASHRAE
2014.
198–
Section(s) in
AHRI 920–2020
that reference this
industry standard
1060–
Section 5; Section 6;
Appendix C.
Section 5; Section 6;
Appendix C.
Section C4.
41.1–
Section C3.3.1.
41.6–
Section C3.1.3.2.
37–
In response to the July 2017 ASHRAE
TP RFI, AHRI commented that the
ISMRE and ISCOP levels specified for
DDX–DOASes in ASHRAE 90.1–2016
will need adjustment if changes to the
test procedure negatively impact these
values (AHRI, No. 11 at p. 20).
This NOPR proposes to incorporate by
reference the latest version of the
industry test procedure for DDX–
DOASes which is recognized by
ASHRAE Standard 90.1: AHRI 920 (the
latest version being AHRI 920–2020).
When the test procedures referenced in
ASHRAE Standard 90.1 are updated,
EPCA requires DOE to amend the
Federal test procedures for such covered
ASHRAE equipment (which
manufacturers are required to use in
order to certify compliance with energy
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conservation standards mandated under
EPCA) to be consistent with the
amended industry consensus test
procedure. (42 U.S.C. 6314(a)(4)(B))
The energy efficiency standards
specified in ASHRAE Standard 90.1 are
based on ANSI/AHRI 920–2015 and
ANSI/ASHRAE 198–2013. However, the
amendments adopted in AHRI 920–2020
result in changes to the measured
efficiency metrics as compared to the
results under ANSI/AHRI 920–2015. As
discussed, DOE has not established in
its regulations energy conservation
standards specifically for DDX–DOASes.
DOE will address any potential
differences in the measured energy
efficiency under the most recent
industry test procedure as compared to
the industry test procedure on which
the ASHRAE Standard 90.1 levels are
based at such time as DOE evaluates the
ASHRAE Standard 90.1 levels for DDX–
DOASes (i.e., by developing an
appropriate crosswalk, as necessary).
Specifically, DOE intends to request that
DDX–DOAS manufacturers provide any
data and/or analysis that indicates
whether and how much the measured
rating of DDX–DOASes would be
expected to change under the most
recent version of the industry consensus
test standard.
Issue–4: DOE requests comment and
data on the development of a crosswalk
from the efficiency levels in ASHRAE
Standard 90.1 based on ANSI/AHRI
920–2015 to efficiency levels based on
AHRI 920–2020. DOE is specifically
seeking data on how dehumidification
and heating efficiency ratings for a given
DDX–DOAS model are impacted when
measured using AHRI 920–2020 as
compared to ANSI/AHRI 920–2015.
2. Efficiency Metrics
khammond on DSKJM1Z7X2PROD with PROPOSALS3
a. Dehumidification Metric
ASHRAE 90.1–2016 adopted a
dehumidification efficiency metric for
DDX–DOASes. Specifically, ASHRAE
90.1–2016 uses ISMRE, as presented in
section 3.10 of ANSI/AHRI 920–2015, as
a seasonal efficiency metric calculated
as a weighted average of MRE for four
different dehumidification rating
conditions. MRE for each test condition
is the MRC for that condition divided by
electric power input, including
consideration of electric resistance
reheat if needed to raise supply air
temperature to 70 °F (i.e.,
‘‘supplementary heat’’). MRC represents
the rate at which the DDX–DOAS
removes humidity from the air in
pounds of moisture per hour. As
discussed further in section III.B.2.c of
this document, AHRI indicated that the
seasonal weighting factors for
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determining ISMRE, as specified in
ANSI/AHRI 920–2015, were developed
based on climate data from a sample of
twelve cities chosen to be representative
of a wide range of climatic data in the
United States.
The primary function of DDX–
DOASes is to provide conditioned
(cooled and dehumidified, or heated)
outdoor air. In the cooling/
dehumidifying season, these units
provide sensible cooling that reduces
the temperature of the outdoor air in
addition to dehumidifying. DOE noted
in the July 2017 ASHRAE TP RFI that
the ISMRE metric specified in ANSI/
AHRI 920–2015 does not include any
provisions to measure the sensible
cooling contribution provided by the
DDX–DOAS. 82 FR 34427, 34436 (July
25, 2017). For Standard Rating
Conditions A and B in Table 2 and
Table 3 of ANSI/AHRI 920–2015,
conditioning the air to a space
temperature (70 °F) requires sensible
cooling as well as latent cooling. In the
July 2017 ASHRAE TP RFI, DOE
requested comment on whether the
DDX–DOAS efficiency metric should
account for this sensible cooling. 82 FR
34427, 34436 (July 25, 2017).
In response to the July 2017 ASHRAE
TP RFI, AHRI commented that DDX–
DOASes operate with a separate,
sensible-cooling-only interior cooling
system, and that adding sensible cooling
to the metric for DDX–DOAS would
skew efficiency values toward the nonprimary function of the DDX–DOAS.
AHRI also stated that the capacity for
sensible cooling varies between DDX–
DOAS designs, so the use of spaceneutral air 18 gives a worst-case
efficiency to be used as comparison.
(AHRI, No. 11 at p. 12) Carrier
expressed concern that the current
metric focuses on latent capacity and
that a shortcoming of the test procedure
is that it does not consider sensible
capacity. Carrier also stated that
considering only latent capacity would
be acceptable if the unit delivers spaceneutral air, but some DDX–DOASes can
provide sensible cooling. (Carrier, No. 6
at p. 3)
As discussed in section III.B.2.c of
this NOPR, DOE proposes to incorporate
by reference the dehumidification
metrics contained in the updated
version of the industry consensus
standard, AHRI 920–2020. DOE notes
that the revised dehumidification metric
in AHRI 920–2020, ISMRE2, does not
include provisions to determine the
air, or neutral air, refers to air
leaving an air conditioner being at the target
conditions for the occupied space in the building
(without the need for subsequent sensible or latent
cooling).
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36027
sensible cooling contribution in the
metric. However, as discussed in section
III.B.1 of this document, the ISMRE2
metric, which is specified in AHRI 920–
2020 as the required rating metric for
dehumidification efficiency, removes
the supplementary heat penalty to avoid
penalizing DDX–DOAS units that
provide sensible cooling below 70 °F.
DOE recognizes that the sensible
cooling provided by a DDX–DOAS unit
may be valuable in many applications
because it reduces the cooling that must
be provided by interior cooling systems,
especially at high outdoor temperatures.
However, for certain applications it may
be important to reheat the supply air to
balance the building’s sensible cooling
load.19 DOE may consider in a future
rulemaking whether the efficiency
metric should be revised to include
sensible cooling, if information is made
available to support such a change.
ASHRAE Standard 90.1–2016 uses
ISMRE (using ANSI/AHRI 920–2015) as
the metric for the specified minimum
efficiencies for DDX–DOAS. As
discussed in section III.B.1 of this
NOPR, DOE is aware that updates to the
industry test procedure in AHRI 920–
2020 using ISMRE2 could impact the
measured efficiencies of DDX–DOASes
as compared to ISMRE measured in
accordance with ANSI/AHRI 920–2015,
thereby necessitating use of an
appropriate crosswalk analysis.
Therefore, DOE will address these
potential impacts on the measured
efficiencies in a separate standards
rulemaking.
b. Heating Metric
ASHRAE 90.1–2016 adopted ISCOP,
as presented in ANSI/AHRI 920–2015,
as the heating efficiency metric, and it
also set minimum ISCOP efficiency
levels for both air-source and watersource heat pump DDX–DOASes. ISCOP
is a seasonal energy efficiency metric
and is calculated as the seasonal
weighted average of heating COPs
determined for two heating Standard
Rating Conditions specified in Table 2
and Table 3 of ANSI/AHRI 920–2015.
In the July 2017 ASHRAE TP RFI,
DOE noted that although the
Department has identified air-source
heat pump DDX–DOASes available on
the market, section 3.9 of ANSI/AHRI
920–2015 defines ISCOP as an energy
efficiency metric only for water-source
heat pump DDX–DOASes. 82 FR 34427,
34436 (July 25, 2017). DOE also noted
19 As discussed in section III.B.1 of this
document, AHRI 920–2020 include separate
application metrics (i.e., ISMRE270) to be used for
additional representations and that are calculated
with a supplementary heat penalty based on raising
the supply air dry-bulb temperature up to 70 °F.
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in the July 2017 ASHRAE TP RFI that
equations in section 10.9 of ANSI/
ASHRAE 198–2013 for calculating the
COP are labeled for application to
water-source heat pump DDX–DOASes,
although DOE once again noted that
they could be applied to air-source heat
pump DDX–DOASes. Id. As part of the
July 2017 ASHRAE TP RFI, DOE
requested comment on the calculation
procedure for COP for air-source heat
pumps, including whether the equations
in ANSI/ASHRAE 198–2013 are
applicable to air-source heat pumps. Id.
DOE did not receive any comments on
this topic. Because ASHRAE Standard
90.1–2016 specifies minimum efficiency
levels for both air-source and watersource heat pump DDX–DOASes using
ANSI/AHRI 920–2015, DOE considers
the ISCOP and COP calculations to be
applicable to the minimum efficiency
levels in ASHRAE Standard 90.1–2016
for both equipment classes.
In further clarification, AHRI 920–
2020 revised the definition of ‘‘Direct
Expansion-Dedicated Outdoor Air
System Units’’ and the heating
efficiency metric (designated as ISCOP2)
to include both air-source and watersource heat pump DDX–DOASes. The
ISCOP2 metric specified in section 3.13
of AHRI 920–2020 also includes
revisions to the outdoor air conditions,
weighting factors, and treatment of
heating capacity calculations. DOE is
proposing to adopt ISCOP2 as the
heating efficiency metric for DDX–
DOASes under the DOE test procedure,
expressed in Watts (W) of heating
capacity per W of power input. As
discussed in section III.B.1 of this
NOPR, updates to the industry
consensus test procedure in AHRI 920–
2020 using ISCOP2 could impact the
measured heating efficiencies of DDX–
DOASes as compared to ISCOP
measured in accordance with ANSI/
AHRI 920–2015, thereby necessitating
use of an appropriate crosswalk
analysis. Therefore, DOE will address
these potential impacts on the measured
heating efficiencies in a separate
standards rulemaking.
ISCOP2 is calculated using
COPISCOP values for Standard Rating
Conditions E and F that apply a
supplementary heat penalty to the total
power input if the supply air dry-bulb
temperature is less 70 °F. Section 6.11 of
AHRI 920–2020 includes additional
application rating heating metrics,
COPfull and COPDX–DOAS, for additional
representations. COPDX–DOAS is
calculated without a supplementary
heat penalty, while COPfull is used for
manufacturer-specified outdoor
conditions. DOE is proposing in section
2.2.2 of Appendix B to allow COPfull and
COPDX–DOAS to be used by
manufacturers for voluntary
representations.
c. ISMRE2 and ISCOP2 Weighting
Factors
As part of the July 2017 ASHRAE TP
RFI, DOE requested information about
analysis of climate data relevant to the
development of the ISMRE and ISCOP
test conditions and weighting factors. 82
FR 34427, 34436 (July 25, 2017). AHRI
commented that the values and
weightings for both the
dehumidification and heating points in
ANSI/AHRI 920–2015 were developed
based on climatic data for a sample of
twelve cities 20 chosen to be
representative of a wide range of
climatic conditions in the United States.
According to AHRI, the climatic bin
data were based on 24-hour operation
per day due to the variety of
applications where DDX–DOASes are
installed and provide a reasonable
standard for assessing the part-load
situations that will be encountered.
(AHRI, No. 11 at p. 12) DOE notes that
these test conditions in ANSI/AHRI
920–2015 were established to represent
specific regions of the psychrometric
chart, as shown in the following Table
III–2 and Table III–3.
In the development of AHRI 920–
2020, DOE provided input on weather
data, and AHRI also reviewed Typical
Meteorological Year (TMY) 2 21 weather
data from the National Renewable
Energy Laboratory. Based, in part, on
this input and data, AHRI 920–2020
specifies the ISMRE2 and ISCOP2 test
conditions and weighting factors, which
represent the number of hours per year
for each test condition. Accordingly,
Table III–2 and Table III–3 also show
the Standard Rating Conditions and
weighting factors included in sections
6.1, 6.12, and 6.13 of AHRI 920–2020.
DOE is proposing to adopt the weighting
factors for the ISMRE2 (including the
test conditions specific for ISMRE270)
and ISCOP2 metrics, as specified in
AHRI 920–2020.
TABLE III–2—ANSI/AHRI 920–2015 AND AHRI 920–2020 DEHUMIDIFICATION MODE STANDARD RATING CONDITIONS AND
ISMRE/ISMRE2/ISMRE270 WEIGHTING FACTORS
ANSI/AHRI 920–2015
Standard
rating
condition
A ..............
B ..............
C ..............
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D ..............
Representative
condition
(dry-bulb temperature/
wet-bulb temperature)
Above 55 °F dew point, Above 75 °F wet-bulb ....
Above 55 °F dew point, >69 °F and ≤75 °F wetbulb.
Above 55 °F dew point, >62 °F and ≤69 °F wetbulb.
Above 55 °F dew point, >56 °F and ≤62 °F wetbulb.
95 °F/78 °F ....................
80 °F/73 °F ....................
12
28
95 °F/78 °F ....................
80 °F/73 °F ....................
14
34
68 °F/66 °F ....................
36
70 °F/66 °F ....................
39
60 °F/58 °F ....................
24
63 °F/59 °F ....................
13
18:50 Jul 06, 2021
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ISMRE
weighting
factor
21 TMY stands for ‘‘typical meteorological year’’
and is a widely used type of data available through
the National Solar Radiation Database. TMYs
contain one year of hourly data that best represents
median weather conditions over a multiyear period.
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Representative
condition
(dry-bulb temperature/
wet-bulb temperature)
ISMRE2
and
ISMRE270
weighting
factor
Psychrometric chart region represented
20 The sample of 12 cities analyzed were: New
York City, Atlanta, Chicago, El Paso, Houston,
Kansas City, Miami, Minneapolis, Nashville, New
Orleans, Norfolk, and Tucson.
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AHRI 920–2020
The datasets have been updated occasionally, thus
TMY, TMY2, and TMY3 data are available. See
nsrdb.nrel.gov/about/tmy.html (last accessed 4/28/
21).
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TABLE III–3—ANSI/AHRI 920–2015 AND AHRI 920–2020 HEATING MODE STANDARD RATING CONDITIONS AND ISCOP/
ISCOP2 WEIGHTING FACTORS
ANSI/AHRI 920–2015
Standard
rating
condition
E ..............
F ..............
Psychrometric chart region represented
Representative
condition
(dry-bulb temperature/
wet-bulb temperature)
Below 55 °F dew point, >23 °F and ≤64 °F drybulb.
Below 55 °F dew point, ≤23 °F dry-bulb ..............
35 °F/29 °F ....................
77
47 °F/43 °F ....................
91
16 °F/12 °F ....................
23
17 °F/15 °F ....................
9
3. Test Method
This section discusses the various
issues that DOE identified in the
industry consensus test standards
applicable to DDX–DOASes, including
those raised in the July 2017 ASHRAE
TP RFI and considered as part of DOE’s
review of AHRI 920–2020. These issues
include: (1) Definitions for certain terms
used in the DDX–DOAS test procedure;
(2) optional break-in period for DDX–
DOASes; (3) test facility,
instrumentation, and apparatus set-up
issues; (4) DDX–DOAS unit set-up; (5)
test operating conditions; (6)
requirements for water-cooled and
water-source heat pump DDX–DOASes;
(7) defrost energy use; (8) test methods
for DDX–DOASes equipped with VERS;
(9) tolerances; and (10) secondary
verification tests for dehumidification
and heating tests.
Table 1 to 10 CFR 431.96 specifies the
applicable industry test procedure for
each category of commercial package air
conditioning and heating equipment
and specifies any additional testing
requirements that may also apply. In
this NOPR, DOE is proposing to add test
procedure requirements for DDX–
DOASes in a separate appendix in
subpart F to 10 CFR part 431 (i.e.,
proposed Appendix B). Accordingly,
DOE proposes to include DDX–DOASes
in Table 1 to 10 CFR 431.96 and to
reference Appendix B for the DDX–
DOASes test procedure.
khammond on DSKJM1Z7X2PROD with PROPOSALS3
a. Definitions
Section 3 of AHRI 920–2020 and
section 3 of ANSI/ASHRAE 198–2013
define terms used in the industry
consensus test standards for DDX–
DOASes. DOE reviewed these sections
and is proposing generally to adopt the
definitions in section 3 of AHRI 920–
2020 (as enumerated in section 2.2.1(a)
of proposed Appendix B). As discussed,
DOE is proposing definitions in the test
procedure provisions for ‘‘direct
expansion-dedicated outdoor air system,
or DX–DOAS’’ as a category of
commercial package air conditioning
and heating equipment, and
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ISCOP
weighting
factor
‘‘dehumidifying direct expansiondedicated outdoor air system, or DDX–
DOAS,’’ as a subset of DX–DOAS.
As discussed in the following
paragraphs DOE is also proposing to
define ‘‘integrated seasonal coefficient
of performance 2, or ISCOP2,’’
‘‘integrated seasonal moisture removal
efficiency 2, or ISMRE2,’’ and
‘‘ventilation energy recovery system, or
VERS.’’ In section 1.1 of Appendix B,
DOE proposes to provide that where any
definitions conflict between AHRI 920–
2020 (or any of the industry standards
referenced) and the CFR, the CFR
provisions control.
DOE notes that 10 CFR 431.92
includes definitions for the efficiency
metrics used for commercial package air
conditioners and heat pumps.
Consistent with this approach, DOE is
proposing definitions at 10 CFR 431.92
for ‘‘integrated seasonal coefficient of
performance 2, or ISCOP2’’ and
‘‘integrated seasonal moisture removal
efficiency 2, or ISMRE2’’ that are
consistent with the definitions for these
metrics defined in sections 3.12 and
3.13 of AHRI 920–2020 and that
specifically reference the DDX–DOAS
test procedure in proposed Appendix B.
A ‘‘ventilation energy recovery
system’’ (VERS) pre-conditions the
outdoor air before it enters the
conditioning coil, thereby reducing the
cooling, dehumidification, or heating
load on the refrigeration system of the
DDX–DOAS. ASHRAE Standard 90.1–
2019 specifies separate equipment
classes and minimum efficiency levels
for DDX–DOASes with VERS
equipment. DOE notes that neither a
definition for a VERS nor a different
term for this system is included in the
previous test standards ANSI/AHRI
920–2015 and ANSI/ASHRAE 198–
2013. However, AHRI 920–2020 does
include a definition for VERS. DOE
proposes, consistent with AHRI 920–
2020, to define a VERS as a system that
preconditions outdoor ventilation air
entering the equipment through direct
or indirect thermal and/or moisture
exchange with the exhaust air, which is
defined as the building air being
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Representative
condition
(dry-bulb temperature/
wet-bulb temperature)
ISCOP2
weighting
factor
exhausted to the outside from the
equipment.
A VERS may also be used by
commercial air-conditioning equipment
other than DDX–DOASes. However, for
commercial air-conditioning equipment
other than DDX–DOASes, neither
ASHRAE Standard 90.1–2019 nor the
DOE energy conservation standards
establish equipment classes based on
the presence of VERS. Under the DOE
test procedures for commercial package
air conditioners and heat pump
equipment other than DDX–DOASes,
VERS is a feature that is not installed for
testing. Because an understanding of
VERS may be relevant to commercial
package air conditioners and heat
pumps other than the proposed DDX–
DOAS category of equipment, DOE is
proposing to establish a definition of
VERS, consistent with AHRI 920–2020,
in 10 CFR 431.92 so that it is broadly
applicable when used in reference to
both DDX–DOASes as well as other
commercial package air conditioning
and heat pump equipment.
Additionally, DOE is proposing to
amend the definition of ‘‘commercial
HVAC & WH product’’ at 10 CFR 431.2
to explicitly include DDX–DOAS.
Issue–5: DOE requests comment on
the terminology DOE proposes to use for
DDX–DOASes, including ‘‘integrated
seasonal coefficient of performance 2, or
ISCOP2;’’ ‘‘integrated seasonal moisture
removal efficiency 2, or ISMRE2;’’ and
‘‘ventilation energy recovery system, or
VERS.’’
In the July 2017 ASHRAE TP RFI,
DOE sought clarification on the
difference between a reheat system and
supplementary heat in ANSI/AHRI 920–
2015 and ANSI/ASHRAE 198–2013. 82
FR 34427, 34436 (July 25, 2017). The
definition for supplementary heat
provided in section 3.21 of ANSI/AHRI
920–2015 does not state whether it
includes heat provided by reheat
systems such as wrap-around heat pipes
and wrap-around vapor compression
systems.
In response to the July 2017 ASHRAE
TP RFI, AHRI suggested a revised
definition for ‘‘supplementary heat’’ that
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excludes heat provided by the vapor
compression cycle or a sub-system that
transfers heat from one part of the unit
to another (e.g., wrap-around heat pipe,
wrap-around vapor compression
system). (AHRI, No. 11 at p. 11)
DOE notes that section 3.25 of AHRI
920–2020 has clarified this issue by
defining ‘‘supplementary heat’’ to
exclude a system that transfers heat
from the outdoor air to the supply air.
The AHRI 920–2020 definition
distinguishes reheat provided by a
vapor compression cycle that is driving
the dehumidification process from
common supplementary heat options
such as fuel-fired heating, steam or hot
water heating coils, and electric
resistance. Further, section 3.25 of AHRI
920–2020 also states that reheat
provided by secondary heat pumps,
wrap around heat pumps, or wrap
around heat pipes are not considered as
supplementary heat. As discussed, DOE
proposes to adopt the definition for
‘‘supplementary heat’’ provided in
section 3.25 of AHRI 920–2020, as
enumerated in section 2.2.1(a) of the
proposed Appendix B, which references
section 3 of AHRI 920–2020.
b. Break-In Period
As part of the DOE test procedures for
other commercial package air
conditioners and heat pumps, DOE
provides the option for a ‘‘break-in’’
period, not to exceed 20 hours, with no
ambient temperature requirements,
prior to performing a test. See 10 CFR
431.96(c). This is intended to allow the
unit to achieve optimal performance
prior to the test. Neither ANSI/AHRI
920–2015 nor ANSI/ASHRAE 198–2013
specify a break-in period for testing
DDX–DOASes. In response to the July
2017 ASHRAE TP RFI, AHRI
commented that proper compressor
break-in must be allowed to provide a
fair and accurate test. AHRI also stated
that it had previously submitted
comments that 16 hours is not
sufficient. (AHRI, No. 11 at p. 20)
DOE addressed comments previously
submitted by AHRI that DOE should
require a minimum 16-hour break-in
period for all commercial air
conditioning equipment as part of the
rulemaking finalized in a May 16, 2012
final rule for energy conservation
standards and test procedures for
commercial heating, air-conditioning,
and water-heating equipment. 77 FR
28928, 28943. As part of that final rule,
DOE determined that adopting a
minimum break-in period of 16 hours
would unnecessarily increase testing
costs for manufacturers of equipment
that can achieve stability in less than 16
hours. In recognition that different
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equipment will require different
amounts of break-in time to achieve
optimal performance and that break-in
periods of longer than 16 hours may be
required for some equipment, DOE
adopted an optional break-in period up
to a maximum period of 20 hours to
allow the unit to achieve optimal
performance before testing for
commercial air conditioning and
heating equipment. 77 FR 28928,
28943–28944 (May 16, 2012). Section
5.6 of AHRI 920–2020 incorporates the
same break-in period provision, not to
exceed 20 hours. Therefore, DOE
proposes to adopt the optional break-in
period up to a maximum of 20 hours for
DDX–DOASes specified in AHRI 920–
2020 (section 5.6 Break-in), as
enumerated in section 2.2.1(b) of the
proposed Appendix B, which references
section 5 of AHRI 920–2020.
c. Airflow-Measuring Apparatus
Figures 1 and 2 of ANSI/ASHRAE
198–2013 present the typical test set-up
for DDX–DOASes with and without
energy recovery. The figures show
airflow and condition measuring
apparatus at both the inlet and the
outlet ends of each airflow path (i.e., the
outdoor/supply and return/exhaust
paths). DOE stated in the July 2017
ASHRAE TP RFI that it is not clear
whether airflow-measuring apparatus
are required for both entering and
leaving air of each airflow path. 82 FR
34427, 34439 (July 25, 2017). DOE
requested comment on whether it is
beneficial or necessary to use two
airflow-measuring apparatus per
airstream when testing DDX–DOAS
equipment. Id.
AHRI and Carrier both commented
that using two airflow devices per
airstream would be difficult and costly
due to challenges with space
constraints, additional physical barriers
that can increase temperature
stratification in the test chamber, and
issues associated with meeting the
specified design conditions due to fan
reheat energy in the airflow measuring
stations. (AHRI, No. 11 at p. 19; Carrier,
No. 6 at p. 7) AHRI further commented
that while additional airflow measuring
stations have the benefit of monitoring
cross-leakage or general leakage in the
cabinet, it makes testing difficult, if not
impossible, to perform. (AHRI, No. 11 at
p. 19) None of the commenters
indicated that use of two airflowmeasuring apparatus per airflow path is
necessary to obtain accurate
measurements.
Based on comments from AHRI and
Carrier, DOE tentatively concludes that
requiring two airflow-measuring
apparatus per airflow path may be
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unduly burdensome for certain
manufacturers. However, DOE also
recognizes that the additional
measurements may provide an
indication of crossflow and/or leakage.
DOE has tentatively concluded that
AHRI 920–2020 offers a more suitable
approach to airflow measurement, for
the reasons that follow. Section C2.2 of
AHRI 920–2020 requires just one
airflow-measuring apparatus per airflow
path. To provide a check for general
cabinet leakage, section C5.1 of AHRI
920–2020 specifies a methodology for
performing a secondary capacity
measurement that does not require a
second airflow-measuring apparatus
(rather, the methodology for verifying
dehumidification capacity is based on a
measurement of the weight of collected
condensate). The requirement for just
one airflow-measuring apparatus per
airflow path is consistent with the DOE
test procedures for all other commercial
and residential air-conditioning and
heating systems and limits the testing
costs and burden on manufacturers.
Regarding the commenters’ concern
that the fan heat of the airflowmeasuring apparatus might affect the
controlled air conditions, DOE
recognizes that this could affect the
temperature of the return air entering
the DDX–DOAS under test. A similar
issue could occur when duct-inlet
booster fans are used for moving
outdoor air either to the outdoor
ventilation air inlet from a separate
room, or when moving desiccant
regeneration air from another room. On
this topic, section C3.2.2 of AHRI 920–
2020 specifies that in such
circumstances, the air conditions are to
be measured downstream of the fan and
that the sampled air used for the air
condition measurement be returned: (a)
To a location between the flow nozzles
and the fan of a return airflowmeasuring apparatus, or (b) to the
separate room from which air is drawn
when a boost fan is used in the inlet
duct. Accordingly, in this NOPR, DOE is
proposing to adopt the provisions for
the airflow-measuring apparatus
specified in AHRI 920–2020 section
C2.2, ‘‘Use of a Single Airflow Rate
Measuring Apparatus per Airflow Path’’
in Appendix C of AHRI 920–2020
(rather than the dual measurement
apparatus specifications in Figures 1
and 2 of ANSI/ASHRAE 198–2013), as
enumerated in section 2.2.1(f) of the
proposed Appendix B, which references
Appendix C of AHRI 920–2020.
d. Test Operating Conditions
Through incorporation by reference of
AHRI 920–2020, DOE is proposing to
adopt the test operating conditions
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specified in AHRI 920–2020 for DDX–
DOAS units. These include: (1)
Standard Rating Conditions (Tables 4
and 5 of section 6 of AHRI 920–2020, as
enumerated in section 2.2.1(c) of the
proposed Appendix B, which references
section 6 of AHRI 920–2020 omitting
sections 6.1.2 and 6.6.1); (2) simulated
ventilation air conditions for testing
under Option 2 for DDX–DOASes with
VERS (section 5 of AHRI 920–2020
(which includes section 5.4.1.2 Option
2), as enumerated in section 2.2.1(b) of
the proposed Appendix B, which
references section 5 of AHRI 920–2020);
(3) atmospheric pressure (section 5 of
AHRI 920–2020 (which includes section
5.10 Atmospheric Pressure), as
enumerated in section 2.2.1(b) of the
proposed Appendix B); (4) target supply
air conditions (section 6 of AHRI 920–
2020 (which includes section 6.1.3
Supply Air Dewpoint Temperature and
section 6.1.4 Supply Air Dry Bulb
Temperature), as enumerated in section
2.2.1(c) of the proposed Appendix B);
(5) external static pressure (section 6 of
AHRI 920–2020 (which includes section
6.1.5.6 External Static Pressure), as
enumerated in section 2.2.1(c) of the
proposed Appendix B); and (6) target
supply and return airflow rates (section
6 of AHRI 920–2020 (which includes
section 6.1.5 Supply and Return Airflow
Rates), as enumerated in section 2.2.1(c)
of the proposed Appendix B).
DOE received comments from
interested parties regarding target
supply and return airflow rates and
target supply air conditions in response
to the July 2017 ASHRAE TP RFI, and
the following section discusses these
specific issues.
khammond on DSKJM1Z7X2PROD with PROPOSALS3
i. Target Supply and Return Airflow
Rates
Section 5.2.2 of ANSI/AHRI 920–2015
and section 8.1 of ANSI/ASHRAE 198–
2013 require the supply airflow rate to
be set in accordance with manufacturer
specifications. In the July 2017 ASHRAE
TP RFI, DOE observed that many DDX–
DOAS models are capable of operating
over a range of airflow rates. 82 FR
34427, 34437 (July 25, 2017). DOE
expects these models to have supply air
fans that can be configured with a range
of speeds to accommodate the airflow
range and the variation in duct length in
field installations. Id. The performance
of these models may also vary
significantly from the low end to the
high end of the specified airflow range.
As part of the July 2017 ASHRAE TP
RFI, DOE sought comments on how
manufacturers select the airflow rate for
testing, given the large range of airflows
that are typical of DDX–DOAS units. Id.
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In response to this issue, AHRI
commented that the optimum-efficiency
airflow varies with each application and
that the manufacturer should specify the
design airflow rate as long as it achieves
the 55 °F dew point temperature. (AHRI,
No. 11 at pp. 13–14) The approach
described by AHRI is consistent with
the approach of AHRI 920–2020, which
stipulates the use of the manufacturerspecified airflow in section 6.1.5 of that
document. This section of AHRI 920–
2020 also addresses how to set the
airflow when it is not specified by the
manufacturer and the case where the
dehumidification provided is not
consistent with DDX–DOAS
performance (i.e., provision of supply
air at 55 °F or lower dew point, when
using the manufacturer-specified
airflow).22
As discussed, DOE is proposing to
adopt the provisions in section 6.1.3
and 6.1.5 of AHRI 920–2020, which
specify that the target supply airflow
rate be the manufacturer-specified
airflow rate and that, for Standard
Rating Condition A, achieves
dehumidification consistent with
providing a 55 °F dew point temperature
in standard atmospheric pressure
conditions. In cases where supply
airflow is not specified by the
manufacturer, or supply air dew point
exceeds the maximum when using the
manufacturer-specified airflow, AHRI
920–2020 requires setting airflow for
Standard Rating Condition A such that
the supply air dew point does not
exceed the maximum.
ii. Units With Cycle Reheat Functions
As part of the July 2017 RFI, DOE
noted that provisions regarding reheat
and the supplementary heat penalty
specified in ANSI/AHRI 920–2015 and
ANSI/ASHRAE 198–2013 were unclear.
82 FR 34427, 34436 (July 25, 2017).
Most of the DDX–DOAS models that are
equipped with the capability to reheat
dehumidified air to space-neutral
conditions use hot refrigerant gas
discharged by the compressor to reheat
the dehumidified air leaving the
evaporator coil. Other approaches can
also be used to transfer heat from one
part of the DDX–DOAS to another.
(Section 3.21.1 of AHRI 920–2020
defines all of these methods as ‘‘cycle
reheat.’’) Reheat may also be provided
by supplementary heat sources, such as
a gas furnace or an electric resistance
heater, but these are not considered
cycle reheat. A discussion of cycle
22 Section 6.1.3 of AHRI 920–2020 includes an
adjustment for maximum supply air dew point
temperature to increase linearly as barometric
pressure decreases, up to 57.3 °F at the minimumallowed 13.7 psia test pressure.
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36031
reheat capability with respect to the
scope of this test procedure is provided
in section III.A.4 of this document, and
a discussion of the supplementary heat
penalty is provided in section III.B.3.a
of this document.
ANSI/AHRI 920–2015 requires that
supply air dew point temperature be
55 °F or lower, which generally means
(i.e., for a DDX–DOAS that removes
moisture by latent cooling without the
use of desiccants) that the air must be
cooled to a temperature that is, at most,
a few degrees above 55 °F. Section 6 of
ANSI/AHRI 920–2015 does not
explicitly require testing with reheat
turned on, but note 3 to Table 2 and
note 3 to Table 3 of that industry
standard require the DDX–DOAS to
condition supply air to a minimum drybulb temperature of 70 °F for all
dehumidification and heating tests—
and this would have to be accomplished
with active reheat (as discussed in the
following paragraphs). Further, for units
unable to meet this minimum threshold,
section 6.1.3.1 of ANSI/AHRI 920–2015
specifies the application of a
supplementary heat penalty to represent
the power input that would be required
to heat the supply air to the 70 °F target
using electric resistance heating.
DOE noted in the July 2017 RFI that
ANSI/ASHRAE 198–2013 includes two
dehumidification tests, one with cycle
reheat functions turned on and the other
with cycle reheat functions turned off
(sections 8.3.1.1 and 8.3.1.2,
respectively). DOE further noted that
ANSI/AHRI 920–2015 does not,
however, specify which of these values
is used in the calculation of ISMRE. 82
FR 34427, 34436 (July 25, 2017).
As part of the July 2017 ASHRAE TP
RFI, DOE requested comment on
whether the dehumidification test with
cycle reheat on or off should be used to
calculate ISMRE, and how and when the
supplementary heat penalty is applied.
82 FR 34427, 34436 (July 25, 2017).
AHRI commented that the
dehumidification efficiency metrics
specified in ANSI/AHRI 920–2015 are
based on supply air at a dry-bulb
temperature of 70 °F, and if the unit
requires reheat to be on (as described in
ANSI/ASHRAE 198–2013) for supply air
temperature control, then this reheat-on
test is needed to determine
dehumidification capacity and
efficiency. (AHRI, No. 11 at p. 11) DOE
understands AHRI’s comment to mean
that ANSI/AHRI 920–2015 effectively
requires cycle reheat to be activated
during dehumidification tests in order
to meet both the supply air dew point
and dry-bulb temperature requirements.
In contrast to ANSI/AHRI 920–2015,
AHRI 920–2020 more explicitly
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addresses the use of cycle reheat for
dehumidification tests and provides
more information on when the
supplementary heat penalty should be
used. As discussed in section III.B.2.a of
this NOPR, DOE is proposing to adopt
the revised MRE and ISMRE2 metrics
specified in AHRI 920–2020, which do
not include a supplementary heat
penalty. Section 6.1.4.2 of AHRI 920–
2020 specifies that when determining
MRE and ISMRE2, the manufacturer
shall specify whether cycle reheat is to
be activated for the test. As discussed in
section III.B.2.a of this document, AHRI
920–2020 provides separate application
metrics (i.e., MRE70 and ISMRE270)
which may be used for representations
and which require a supply air dry-bulb
temperature above 70 °F (and below
75 °F). For these separate application
metrics, if cycle reheat cannot achieve
70 °F, a supplementary heat penalty is
applied based on raising the supply air
dry-bulb temperature up to 70 °F (see
section 6.1.4.1 of AHRI 920–2020). DOE
has tentatively determined that these
provisions in AHRI 920–2020 clarify the
requirements for cycle reheat and the
supplementary heat penalty, so the
Department is proposing to adopt these
provisions in this NOPR (section 6 of
AHRI 920–2020, as enumerated in
section 2.2.1(c) of the proposed
Appendix B).
khammond on DSKJM1Z7X2PROD with PROPOSALS3
iii. Target Supply Air Dry-Bulb
Temperature
As discussed, in the July 2017
ASHRAE TP RFI, DOE noted that ANSI/
AHRI 920–2015 includes a requirement
of minimum supply air temperature of
70.0 °F for all Standard Rating
Conditions and a maximum dew-point
temperature of 55.0 °F for Standard
Rating Conditions for dehumidification.
In that document, DOE further noted
that ANSI/ASHRAE 198–2013 requires a
supply air temperature of 75.2 °F or as
close to this value as the controls will
allow during testing. As part of the July
2017 ASHRAE TP RFI, DOE requested
comment on the difference in target
supply air temperature requirements
between ANSI/AHRI 920–2015 and
ANSI/ASHRAE 198–2013, and the
appropriate supply air temperature for
use in the DOE test procedure for DDX–
DOASes. 82 FR 34427, 34438 (July 25,
2017).
AHRI and Goodman commented that
the minimum supply air temperature
should be 70 °F. AHRI added that ANSI/
ASHRAE 198–2013, which was
developed based on previous versions of
AHRI 920 that required a supply air
temperature of 75 °F, is being updated to
reflect the new value of 70 °F. (AHRI,
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No. 11 at p. 17; Goodman, No. 14 at p.
2)
As discussed in the previous
subsection, DOE proposes to incorporate
by reference the provisions in section
6.1.4 of AHRI 920–2020, which specifies
setting the supply air dry-bulb
temperature to within a range of 70–
75 °F for tests to determine
dehumidification metrics. For all
dehumidification tests, 75 °F represents
the maximum supply air dry-bulb
temperature above which a
supplementary cooling penalty must be
applied. As noted in section III.B.3.d.ii
of this NOPR, a supplementary heat
penalty must be applied for ISCOP2
calculations when the minimum supply
air dry-bulb temperature of 70 °F cannot
be met in heating mode.
iv. Target Supply Air Dew-Point
Temperature
Note 5 to Table 2 and note 6 to Table
3 in ANSI/AHRI 920–2015 state that the
maximum dew point for Standard
Rating Conditions A through D shall be
55.0 °F. The industry consensus
standard does not specify whether these
conditions apply to the outdoor air,
supply air, or return air. DOE interprets
these requirements to apply to the
supply air because the humidity levels
for outdoor air and return air are already
specified in the same tables.
Furthermore, although ANSI/AHRI
920–2015 specifies a maximum dew
point temperature, the industry test
standard does not include requirements
to ensure that the dew-point
temperature is maintained at the same
level while testing at the different
Standard Rating Conditions specified in
ANSI/AHRI 920–2015. Many DDX–
DOASes are equipped with modulating/
variable capacity compressors, thereby
allowing control for a given supply air
dew point temperature. Allowing a
lower dew point temperature for
Standard Rating Conditions B, C, and D
specified in ANSI/AHRI 920–2015
could give a better MRE rating for those
test points, but the unit would use more
energy to the extent it provides
unnecessary excess dehumidification if
operated in that manner. DOE also
recognizes that the conditioned space
latent cooling requirements for Standard
Rating Condition A specified in ANSI/
AHRI 920–2015 represent the worst-case
scenario, so there would be no need to
deliver a lower dew point (i.e., excess
dehumidification) for Standard Rating
Conditions B, C, and D. AHRI 920–2020
revises the supply air dew point
requirements. Section 6.1.3 of AHRI
920–2020 requires that the average
supply air dew point for Standard
Rating Condition B, C, and D must be
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within 0.3 °F of the Standard Rating
Condition A dew point value.
Accordingly, in this NOPR, DOE
proposes to adopt the relevant
provisions found in section 6.1.3 in
AHRI 920–2020, which explicitly state
that the supply air dew point
temperature shall be 55.0 °F or below for
all Standard Rating Conditions A
through D when operated at a
barometric pressure of 29.92 in Hg, and
that the supply air dew point
temperature for Standard Rating
Conditions B, C, and D must be within
0.3 °F of the measured supply air dew
point temperature for Standard Rating
Condition A, as noted above.
v. Units With Staged Capacity Control
During testing, DDX–DOAS units with
modulating compressors may be able to
achieve supply air conditions within the
proposed tolerances of the target
conditions for Standard Rating
Conditions B, C, and D. However, units
with staged capacity will not likely be
able to do this because they control
capacity in larger increments. DDX–
DOAS units with staged capacity or
reheat control unable to maintain stable
operation at the proposed dry-bulb and
dew-point temperature targets within
proposed tolerances would have to
cycle between two stages (or cycle
between the compressor(s) being on and
off) to deliver average conditioning
consistent with the target.
Neither ANSI/AHRI 920–2015 nor
ANSI/ASHRAE 198–2013 have
provisions to address units that cycle. In
response to the July 2017 ASHRAE TP
RFI, AHRI commented that the time
average testing method suggested by
DOE in its initial review section 6.6 of
ANSI/AHRI 920–2015 would prevent
credit for over-dehumidifying at
Standard Rating Conditions B, C, and D,
but is excessively complex. Instead,
AHRI recommended a calculated
adjustment that does not credit moisture
removal in excess of the Standard
Rating Condition A design dew-point
temperature. (AHRI, No. 11 at p. 20)
This issue has now largely been
addressed in AHRI 920–2020.
Specifically, section 6 of AHRI 920–
2020 prescribes a method to address
DDX–DOASes with staged capacity
control that is consistent with the
aforementioned method of DOE’s initial
review. It differs from DOE’s suggested
method in that it applies the weighted
averaging on the basis of the supply air
humidity ratio rather than the dew
point, and that it applies any applicable
supplementary cooling or heat penalty
to operation at each particular stage
rather than after determination of a
weighted average supply air dry-bulb
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temperature. Given the development of
defined test requirements and equations
addressing over-dehumidification, DOE
initially concludes that the method in
AHRI 920–2020 is not excessively
complex. AHRI 920–2020 requires that
when testing DDX–DOASes with staged
capacity control in a dehumidification
test condition having a supply condition
dew point target (e.g., Conditions B, C,
or D), if the dew point temperature
cannot be controlled within the
specified test tolerances for a given partload condition, a weighted average of
the results of two tests that bracket the
target dew point temperature will be
used. In this NOPR, DOE is proposing
to adopt the provisions in section 6 of
AHRI 920–2020 for achieving the target
supply air conditions for units with
staged capacity control.
Staging of compressor capacity may
also affect operation in heating mode.
Section 6 of AHRI 920–2020 prescribes
methods for determining COP to
account for cycling between compressor
stages, or for operation when the lowestcapacity compressor stage provides
more capacity than required to heat the
supply air to 75 °F. These methods are
similar to the AHRI 920–2020 method
for addressing staged compressor
capacity for dehumidification.
Accordingly, DOE proposes to adopt the
provisions in AHRI 920–2020 for staged
capacity heat pump DDX–DOASes in
heating mode.
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e. Water-Cooled and Water-Source Heat
Pump DX–DOAS Equipment
i. Test Conditions for Multiple-Inlet
Water Sources
As discussed in the July 2017
ASHRAE TP RFI, the inlet water
temperatures in ANSI/AHRI 920–2015
Table 2 for testing water-cooled DDX–
DOASes differ from the water-source
heat pump inlet temperature conditions
specified in Table 3 for water-source
heat pump DDX–DOASes tested using
the ‘‘water source’’ test conditions. DOE
requested comment on the need for
different dehumidification test
conditions for a water-cooled DDX–
DOAS as compared to a water-source
heat pump DDX–DOAS using the closed
water loop test conditions. 82 FR 34427,
34438 (July 25, 2017). In the July 2017
ASHRAE TP RFI, DOE also pointed out
that Tables 2 and 3 in ANSI/AHRI 920–
2015 include two application
configurations 23 for water-cooled DDX–
DOASes and three application
configurations for water-source heat
23 In the context of ANSI/AHRI 920–2015, an
application configuration specifies test conditions
based on the expected application of the DDX–
DOAS.
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pump DDX–DOASes. Id. DOE notes that
ASHRAE 90.1–2016 established
different standards for each of these five
application configurations.
In response to the July 2017 ASHRAE
TP RFI on this issue, AHRI commented
that the two sets of water temperatures
for water-cooled DDX–DOASes and
water-source heat pump DDX–DOASes
should be identical and that the
differences would be resolved in an
update to ANSI/AHRI 920–2015. (AHRI,
No. 11 at p. 17) AHRI also commented
that in almost all cases, a single design
is used for water-cooled equipment used
with cooling tower water and chilled
water, and, similarly, a single design is
used for all of the water-source
applications, adding that for each of
these cases, a single set of water
conditions can be used for testing. AHRI
recommended that the various entering
water and inlet fluid conditions remain
as presented in the ANSI/AHRI 920–
2015 standard, but any regulated
products are to be tested to the ‘‘Chilled
Water Entering Condenser
Temperature’’ column values in Table 2
and the ‘‘Water Source Heat Pumps’’
column values in Table 3. (AHRI, No. 11
at p. 17)
In response, DOE notes that AHRI
920–2020 still provides separate inlet
fluid rating conditions for the different
water-cooled and water-source heat
pump DDX–DOAS applications but now
identifies some as optional application
rating conditions. In light of the
retention of these separate inlet fluid
rating conditions in AHRI 920–2020,
DOE surmises that AHRI’s and
industry’s original position on these
conditions, as set forth in the comments
in response to the July 2017 ASHRAE
TP RFI, changed during the course of
developing that industry consensus
standard. Table 4 of AHRI 920–2020
continues to include separate inlet fluid
rating conditions for water-cooled
cooling tower and water-cooled chilled
water DDX–DOASes, but Note 3 to
Table 4 of AHRI 920–2020 indicates that
the water-cooled chilled water
condition is the optional application
rating condition, contrary to AHRI’s
recommendation in response to the July
2017 ASHRAE TP RFI. Table 5 of AHRI
920–2020 includes separate inlet fluid
rating conditions for water-source and
ground-source closed-loop heat pump
DDX–DOASes but identifies the groundsource closed-loop conditions as the
optional application rating condition.
Tables 4 and 5 of AHRI 920–2020 also
revise the inlet temperatures of the
rating conditions for water-cooled
cooling tower, water-source heat pump,
and water-source ground-source closedloop heat pump DDX–DOASes. In this
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NOPR, DOE is proposing to adopt the
water/fluid rating conditions provided
in AHRI 920–2020 (section 6 of AHRI
920–2020, which includes Table 4 and
Table 5, as enumerated in section
2.2.1(c) and 2.2.2 of the proposed
Appendix B), including the chilled
water and ground-source closed-loop
conditions specified as optional in
AHRI 920–2020 so as to allow for
voluntary representations for those
applications. In any future energy
conservation standards rulemaking for
DDX–DOASes, DOE would consider
establishing standards and the
corresponding certification
requirements in the context of the inlet
fluid temperature conditions specific for
water-cooled cooling towers and for
water-source heat pumps provided in
Table 4 and Table 5 of AHRI 920–2020,
respectively.
ii. Condenser Liquid Flow Rate
In the July 2017 ASHRAE TP RFI,
DOE noted that ANSI/AHRI 920–2015
provides instructions for setting the
condenser liquid flow rate in section
6.1.4 and condenser liquid entering
temperature in Tables 2 and 3 when
conducting the dehumidification test for
water-cooled and water-source heat
pump DDX–DOASes. 82 FR 34427,
34437 (July 25, 2017). Section 6.1.4 of
ANSI/AHRI 920–2015 indicates to use
the liquid flow rates ‘‘specified by the
manufacturer.’’ The manufacturer must
specify a single liquid flow rate for tests
at all Standard Rating Conditions as
defined in ANSI/AHRI 920–2015, unless
the unit is equipped with automatic
control of the liquid flow rate.
In the July 2017 ASHRAE TP RFI,
DOE noted that ANSI/AHRI 340/360–
2007 and ANSI/AHRI 210/240–2008,
which are incorporated by reference as
DOE’s test procedures for rating watercooled commercial air-conditioning
equipment, specify inlet and outlet
water temperature requirements rather
than relying on manufacturers to
determine water flow rate. Further, both
of these industry consensus standards
specify that the full-load water flow rate
determined for the Standard Rating
Conditions should also be used for partload rating conditions. DOE further
stated in the July 2017 ASHRAE TP RFI
that these test methods reflect the
typical design temperature differential
for cooling towers serving water-cooled
equipment, and they are very common
for control of condenser water pumps;
hence, it is not clear to DOE why the
same test method would not be adopted
for water-cooled DDX–DOAS. 82 FR
34427, 34437 (July 25 2017). As part of
the July 2017 ASHRAE TP RFI, DOE
requested information on how
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condenser water flow rates are set in the
field, how they are controlled at partload, and whether the relevant
provisions in ANSI/AHRI 920–2015
provide sufficient guidance regarding
how to set up water flow for DDX–
DOASes with automatic water flow
control systems. Id.
AHRI and Carrier commented that the
condenser water flow rates should be set
by the manufacturer or the installation
instructions, consistent with ANSI/
AHRI 920–2015. (AHRI, No. 11 at p. 15;
Carrier, No. 6 at p. 5) Carrier added that
for part-load conditions, setting the
condenser water flow rate will depend
on what is needed for head pressure
control, and that this should be defined
in the installation instructions and
followed for the test. Carrier stated that
some equipment may require no control
and that others may use head pressure
flow regulating valves. (Carrier, No. 6 at
p. 5) AHRI argued that any variation in
flow rate that occurs automatically
based on the operation and the
equipment design will be measured
during testing, with the pressure drop at
that flow rate also being measured.
AHRI indicated that the pumping
penalty accounts for different
manufacturer specifications of flow
rates and pressure drop at each of the
test conditions. (AHRI, No. 11 at p. 15)
As part of its update to the industry
consensus test standard for DDX–
DOASes, AHRI added additional
requirements for liquid flow rate. More
specifically, while section 6.1.6.1 of
AHRI 920–2020 continues to provide
that the water flow rate be specified by
the manufacturer, the test method now
adds that it must deliver a liquid
temperature rise no less than 8 °F when
testing under Standard Rating Condition
A. Section 6.1.6.2 of AHRI 920–2020
requires that the flow rate set under
Standard Rating Condition A be used for
testing at the remaining Standard Rating
Conditions (B through F), unless
automatic adjustment of the liquid flow
rate is provided by the equipment.
Section 6.1.6.2 of AHRI 920–2020 also
requires that if condenser water flow
rate is modulated under part-load
conditions, the flow rate must not
exceed the flow rate set for Condition A.
DOE has tentatively concluded that
the addition of a minimum temperature
differential in AHRI 920–2020 better
reflects control strategies for cooling
towers serving water-cooled equipment
and for condenser water pumps while
still leaving flexibility for manufacturers
to specify full-load flow rate and to
implement options for modulating flow
rate at part-load conditions. The
Department notes that the provision
allowing for automatic adjustment of the
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liquid flow rate for part-load tests
accounts for manufacturer control
strategies, such as condenser head
pressure control, and is also accounted
for in the water pump effect (discussed
in the following section). DOE has
tentatively concluded that these
provisions would be representative of
flow rates during an average use cycle
and would not be unduly burdensome
to conduct. Therefore, DOE is proposing
to adopt the liquid flow requirements in
AHRI 920–2020 for water-cooled and
water-source heat pump DDX–DOASes
(section 6 of AHRI 920–2020, which
includes section 6.1.6 Liquid Flow Rates
for Water-Cooled, Water-Source Heat
Pump, and Ground-Source Heat Pump),
as enumerated in section 2.2.1(c) of the
proposed Appendix B.
iii. Water Pump Effect
As part of the July 2017 ASHRAE TP
RFI, DOE noted that ANSI/AHRI 920–
2015 includes an equation for
calculating the ‘‘water pump effect,’’
which is an estimate of the energy
consumption of non-integral water
pumps (i.e., pumps that are not part of
the DDX–DOAS unit and whose power
consumption would, therefore, not
already be part of the measured power).
82 FR 34427, 34438 (July 25 2017). DOE
noted that section 6.1.3 of ANSI/AHRI
920–2015 implies that this calculation
applies solely to water pumps serving
refrigerant-to-liquid heat recovery
devices—no indication is given whether
the equation also applies for pumps
serving water-source or water-cooled
condensers—although it is possible that
the term ‘‘refrigerant-to-liquid heat
recovery device’’ refers to the condenser
of a water-source heat pump DDX–
DOAS. Id.
In the July 2017 ASHRAE TP RFI,
DOE requested confirmation that the
‘‘refrigerant-to-liquid heat recovery
device’’ cited in section 6.1.3 of ANSI/
AHRI 920–2015 is intended to include
heat exchangers used for heat rejection
during the dehumidification cycle, and
comment on whether Equation 1 of this
section for estimating the energy use of
water pumps is appropriate for DDX–
DOASes with water-cooled condensers.
Id. In its comments, AHRI confirmed
that the term ‘‘refrigerant-to-liquid heat
recovery device’’ is intended to include
liquid-to-refrigerant heat exchangers
used in the dehumidification cycle and
heating cycle. (AHRI, No. 11 at p. 16)
The revisions to the industry
consensus testing standard in AHRI
920–2020 clarify this matter and are
consistent with the public comments
received. Section 6.1.6.4 of AHRI 920–
2020 provides the water pump effect
equation, and section 11.1 of AHRI 920–
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2020 states within the definition of
symbol PE,x that the water pump effect
applies to all water-cooled and watersource units without integral water
pumps. Thus, DOE is proposing to
adopt the water pump effect provisions
in sections 6.1.6.4 and 11.1 of AHRI
920–2020 to account for the energy use
of water pumps for water-cooled
condensers, as enumerated in section
2.2.1(c) and section 2.2.1(d) of the
proposed Appendix B, which reference
sections 6 and 11 of AHRI 920–2020,
respectively.
In further clarification, the total pump
effect does not need to be calculated for
pumps that are integral to the DDX–
DOAS, because the power for these
pumps would be measured as part of the
main DDX–DOAS power measurement.
Currently, the number of DDX–DOAS
models on the market with integral
pumps is very limited. However, AHRI
920–2020 does not explicitly state the
amount of external head pressure 24 to
use when testing DDX–DOASes with
integral pumps, a necessary parameter.
DOE notes that the calculation of the
water pump effect for DDX–DOASes
without integral pumps specified AHRI
920–2020 includes a fixed adder of 25
Watts per gallon per minute based on 20
feet of water column of external head
pressure, a value which the Department
reasons could be suitably applied to
DDX–DOASes with integral pumps.
Accordingly, DOE is proposing to
include additional specifications in
section 2.2.1(c)(ii) of proposed
Appendix B that DDX–DOASes with
integral pumps be configured with an
external head pressure equal to 20 feet
of water column (i.e., the same level of
external head pressure used in the
calculation of the pump effect for DDX–
DOASes without integral pumps).
DOE has initially determined that the
proposal to specify the same external
head pressure for integral pumps as the
external head pressure used in the
calculation of the pump effect for DDX–
DOASes without integral pumps is
consistent with the industry consensus
test procedure. The proposed
requirement would provide additional
direction for treatment of integral
pumps consistent with the treatment of
non-integral pumps and would provide
for the representative comparability of
results between DDX–DOASes with and
without integral pumps. To the extent
the industry test procedure does not
specify an external head pressure for
DDX–DOASes with an integral pump,
24 ‘‘External head pressure’’ reflects the pump
power output, in that it represents the height to
which the pump can raise the water if the water
were being moved opposite the force of gravity.
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the industry test procedure would not
ensure that measured results are
comparative, and due to the potential
variation resulting from the absence of
the specification, the industry test
procedure would not ensure that the
results reflect the equipment’s
representative average energy efficiency
or energy use. As such, DOE has
initially determined, supported by clear
and convincing evidence, that in the
absence of a specification for the
external head pressure for an integrated
pump, the industry test procedure
would not meet the statutory
requirements of 42 U.S.C. 6314(a)(2)–(3)
and is, therefore, proposing the
supplemental specification.
In addition, DOE is proposing a
condition tolerance of up to 1 foot of
water column greater than the 20-foot
requirement (which equates to 5
percent), which is equivalent to the
condition tolerance on air side external
static pressure in Table 9 of AHRI 920–
2020 (Test Operating and Test
Condition Tolerances); namely, the
provision in that table provides for up
to 0.05 inch of water column greater
than the target external static pressure,
which is around 1 inch of water
column. Similarly, DOE is proposing an
operating tolerance of up to 1 foot of
water column, which is equivalent to
the operating tolerance on air side
external static pressure in Table 9 of
AHRI 920–2020; namely, the provision
in that table provides for 0.05 inch of
water column. To the extent the
industry test procedure does not specify
a condition tolerance and operating
tolerance for the water column, the
industry test procedure would not
ensure consistent and comparable
results and would not ensure that the
results reflect the equipment’s
representative average energy efficiency
or energy use. As such, DOE has
initially determined, supported by clear
and convincing evidence, in the that
absence of such tolerances for the water
column, the industry test procedure
would not meet the statutory
requirements of 42 U.S.C. 6314(a)(2)–(3)
and is, therefore, proposing the
supplemental specification.
Issue–6: DOE requests comment on
the proposal to require that watercooled and water-source DDX–DOASes
with integral pumps be set up with an
external pressure rise equal to 20 feet of
water column with a condition
tolerance of ¥0/+1 foot and an
operating tolerance of 1 foot.
iv. Energy Consumption of Heat
Rejection Fans and Chillers
Neither ANSI/AHRI 920–2015 nor
ANSI/ASHRAE 198–2013 address
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accounting for the energy consumption
of heat rejection fans (e.g., cooling tower
fans) for water loops serving the
condensers of water-cooled DDX–
DOASes. 82 FR 34427, 34438 (July 25,
2017). DOE noted that section 6.1 of
AHRI 340/360–2007, which is used for
rating certain water-cooled commercial
package air conditioning and heat pump
equipment, provides a power
consumption adjustment for both the
cooling tower fan and the circulating
water pump (it is assumed that the
pump is external to the air conditioning
equipment). Id. In addition, neither
ANSI/AHRI 920–2015 nor ANSI/
ASHRAE 198–2013 address accounting
for the energy consumption of chiller
systems used to provide chilled water to
DDX–DOASes with chilled-watercooled condensers. In the July 2017
ASHRAE TP RFI, DOE requested
comment on accounting for the energy
consumption for heat-rejection fans and
chiller systems employed in watercooled or water-loop DDX–DOASes. Id.
AHRI commented that the AHRI test
standard for certain commercial package
air conditioning and heat pump
equipment includes the cooling tower
fan and pump energy as part of a flat
rate adjustment, but that the
International Organization for
Standardization (ISO) test standard for
water-source heat pumps does not
account for cooling tower fan energy use
at this time. AHRI stated that the
minimum efficiency values for DDX–
DOASes specified in ASHRAE 90.1–
2016 were based on the current ANSI/
AHRI 920–2015 standard that does not
account for the energy consumption of
heat-rejection fans or the chiller system,
although it does account for the
additional water pumping energy (see
the discussion of the water pump effect
in section III.B.3.e.iii of this document).
AHRI stated that, as a result, DOE
should not account for this energy in the
efficiency metric for DDX–DOASes
because doing so introduces unknown
impacts on the design and costs
associated with meeting the minimum
efficiency requirements. (AHRI, No. 11
at pp. 16–17) Carrier also commented
that heat-rejection fans are not part of a
water-cooled unit but are part of the
cooling tower rating and are covered by
Table 6.8.1.7 in ASHRAE 90.1–2016.
(Carrier, No. 6 at p. 5) Carrier
commented that chiller system energy
use should not be included in the
efficiency metric because this is not a
system rating and is only a component
rating method for the DDX–DOAS itself.
(Carrier, No. 6 at p. 6)
The revised AHRI 920–2020 also does
not include energy use of the heatrejection fans and chiller systems
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employed in water-cooled or water-loop
DDX–DOASes. DOE observes that
accounting for this energy use is not a
consistent industry practice, as
evidenced by the differences between
the AHRI 340/360–2007 approach for
more typical commercial package air
conditioning equipment and the ISO
approach for water-source heat pumps.
The heat rejection fan addition for more
typical water-cooled commercial
package air conditioning equipment is a
modest energy adder (around 10 percent
of unit power).25 Furthermore,
including the energy of the heat
rejection fan and chiller systems would
not help to distinguish between models
of different efficiency, since the adder
would be identical for two samecapacity models with different
efficiencies. For these reasons, and
consistent with AHRI 920–2020, DOE is
not proposing in this NOPR to include
any energy consumption associated
with heat rejection fans, cooling towers,
or chiller systems used to cool the water
loops of water-cooled or water-source
DDX–DOASes.
v. Chilled Water Coil Exclusion
In the July 2017 ASHRAE TP RFI,
DOE noted that section 2 of ANSI/
ASHRAE 198–2013 specifically
excludes equipment with water coils
that are supplied by a chiller located
outside of the unit. 82 FR 34427, 34438
(July 25 2017). However, Table 2 in
ANSI/AHRI 920–2015 includes
operating conditions for which a watercooled condenser is supplied with
chilled water, and ASHRAE 90.1–2016
established standard levels for DDX–
DOASes that operate with chilled water
as the condenser cooling fluid. As part
of the July 2017 ASHRAE TP RFI, DOE
requested confirmation that the ANSI/
ASHRAE 198–2013 chiller exclusion
applies to cooling coils rather than
condenser coils. Id.
In response to the July 2017 ASHRAE
TP RFI, AHRI commented that both
ANSI/AHRI 920–2015 and ANSI/
ASHRAE 198–2013 were designed for
units that contain vapor compression
cycle-based cooling and
dehumidification with direct expansion
coils. AHRI stated that direct
application of chilled water coils to cool
and dehumidify is outside the scope of
the standard, as the energy for cooling
is expended at an external source of
chilled water. (AHRI, No. 11 at p. 18)
Carrier commented that chillers should
25 For example, for a minimally-compliant
120,000 Btu/h water-cooled unit with gas heat
having a 12.5 EER (see 10 CFR 431.97 Table 1), the
total electricity use is 120,000 Btu/h ÷ 11.9 Btu/Wh
= 10,084 W, and the heat rejection fan adder is
120,000 Btu/h × (10 W per 1,000 Btu/h) = 1,200 W.
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only be used for cooling coils and not
for condenser heat rejection unless there
is heat reclaim, and that this should be
addressed through a building efficiency
standard such as ASHRAE 90.1.
(Carrier, No. 6 at p. 7)
AHRI 920–2020 did not make a
change to the exclusion of DOASes with
water coils that are supplied by a chiller
located outside of the unit; AHRI’s
comment explains that the exclusion
exists because chilled water coil units
that use the chilled water for cooling are
not DX units, and the industry test
procedures are only for DOASes with
DX cooling. ASHRAE Standard 90.1
does not include standards for non-DX
DOASes such as those with chilled
water coils used for cooling. Based on
AHRI 920–2020, and ANSI/ASHRAE
198–2013 as referenced, and the
comments received, DOE did not
consider DOAS units that use chilled
water coils directly for cooling and
dehumidifying. However, the comments
provided in response to the July 2017
ASHRAE TP RFI, as discussed in
section III.B.3.e.i of this document,
indicate that DX–DOASes and DDX–
DOASes may still use chilled water for
condenser coils. (AHRI, No. 11 at p. 17)
f. Defrost Energy Use for Air-Source
Heat Pump
In the July 2017 ASHRAE TP RFI,
DOE noted that tests conducted at 35 °F
dry-bulb temperature for consumer
central air conditioning heat pumps
(which are air-source) consider the
impacts of defrosting of the outdoor coil
in the energy use measurement (see
section 3.9 of 10 CFR part 430, subpart
B, appendix M), while defrost is not
addressed in ANSI/ASHRAE 198–2013.
82 FR 34427, 34436 (July 25 2017). DOE
stated that defrost has a real impact on
efficiency because of energy use
associated with defrost and because a
system cannot continue to provide
heating during defrost operation,
thereby reducing time-averaged
capacity. Id. Hence, DOE noted that
consideration of defrost could provide a
more field-representative measurement
of performance. DOE requested
comment on whether testing for test
condition E of ANSI/AHRI 920–2015
Table 2 (i.e., 35 °F dry-bulb/29 °F wetbulb) should consider energy use
associated with defrost. Id.
On this issue, AHRI commented that,
due to the constant volume nature of the
airflow in DDX–DOASes, the addition of
defrost to DDX–DOASes presents
challenges, and it is not in a position to
present a proper solution at this time.
AHRI also stated that it is aware of
manufacturers that disable the heat
pump operation in cold temperatures to
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avoid this issue. (AHRI, No. 11 at p. 13)
The Joint Advocates, Goodman, and
Carrier commented that defrost should
be accounted for in the test procedure
to provide a more representative
measurement of field energy use. (Joint
Advocates, No. 9 at p. 4; Goodman, No.
14 at p. 2; Carrier, No. 6 at p. 4) Carrier
added that DOE should use the T-test 26
defined in ANSI/AHRI 340/360 and
ANSI/AHRI 210/240. (Carrier, No. 6 at
p. 4) Goodman indicated that it will be
very difficult to precisely capture
defrost in the DDX–DOASes test
procedure. (Goodman, No. 14 at p. 2)
DOE understands that AHRI is
referring to challenges in field operation
defrosting for air-source heat pump
DDX–DOASes. Preventing cold outdoor
air from being brought into the supply
air stream during a defrosting sequence
(when the DDX–DOAS cannot operate
as a heat pump) would require
interruptions to the supply airflow,
which is inconsistent with building
code requirements to provide a
continuous supply of ventilation air for
most DDX–DOAS applications. DOE is
aware of only a limited number of airsource heat pump DDX–DOAS units.
DOE understands that these units may
not continue heat pump operation
during potential frosting conditions as a
result of these challenges in field
operation. Given these factors, DOE is
not aware of test data (e.g., from T-tests)
for such heat pumps during extended
heating mode operation to understand
better the level of frost accumulation
and associated defrost energy
expenditure. DOE also notes that AHRI
920–2020 does not include any
provisions for testing or calculating the
defrost energy of DDX–DOAS air-source
heat pumps. However, AHRI 920–2020
arguably addresses this issue in another
fashion, namely by providing in section
5.5 that defrost control settings specified
by the manufacturer in installation
instructions may be set prior to heating
mode tests in order to achieve steadystate conditions during the heating
mode tests. As discussed in section
III.B.3.d of this document, DOE is
proposing to adopt the provisions of
AHRI 920–2020 section 5.5, Defrost
Controls for Air-Source Heat Pump
during Heating Mode, as enumerated in
section 2.2.1(b) of the proposed
Appendix B. If these settings fail to
prevent frost accumulation during the
heating mode tests (resulting in
unsteady conditions), then the
26 The T-test is a non-steady-state (transient) test
that includes measurement of both the heating
energy use as the outdoor coil accumulates frost
and the defrost energy use as the unit undergoes
multiple defrost cycles, as referenced in section
8.8.3 of ANSI/ASHRAE 37–2009.
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manufacturer would need to seek a
waiver from the test procedure to obtain
an alternate method of test from DOE
pursuant to 10 CFR 431.401. However,
section 5.5 of AHRI 920–2020 also
specifies that the Standard Rating
Condition F heating mode test (which
represents low temperature
environmental conditions where
frosting is likely) is optional to conduct,
and if the Standard Rating Condition F
test is not conducted, a default COP of
1.0 (corresponding to electric resistance
heating) is assigned at this rating point
instead. Therefore, the manufacturer
may choose to not conduct a test at
Standard Rating Condition F instead of
seeking a waiver. DOE has tentatively
concluded that the test method set forth
in section 5.5 of AHRI 920–2020 for
defrost controls for air-source heat
pump DDX–DOASes during heating
mode offers a reasonable and workable
approach, so the Department proposes
to adopt such approach into the Federal
test procedure.
Due to the lack of sufficient
information on how air-source heat
pump DDX–DOAS units operate under
frosting conditions, DOE is not
proposing to include any provisions for
including the defrost energy of DDX–
DOAS air-source heat pumps.
g. General Control Setting Requirements
Requirements for adjustment of unit
controls during set-up for testing of a
DDX–DOAS are addressed in specific
sections of AHRI 920–2020. Some
examples include the following. Section
5.2, ‘‘Equipment Installation,’’ requires
that units be installed per
manufacturer’s installation instructions
(MII). Section 5.4.3, ‘‘Deactivation of
VERS,’’ indicates that operation of the
VERS may be deactivated for Standard
Rating Conditions C or D if the VERS is
capable of being deactivated. Section
5.5, ‘‘Defrost Controls for Air-Source
Heat Pump during Heating Mode,’’
provides instructions for setting of
defrost controls.
However, DOE notes that the test
standard provides no general
requirements indicating whether control
settings can be adjusted as the test
transitions through the four Standard
Rating Conditions used for testing.
Manual readjustment of control settings
would not generally occur in field
operation of DDX–DOASes as outdoor
air conditions change (i.e., in the field,
controls are configured at the time of
installation and would not be actively
adjusted on an ongoing basis in
response to changes in outdoor
temperature or humidity). Hence, to
further ensure the representativeness of
the test procedure, DOE is proposing
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inclusion of a general requirement that
control settings remain fixed and that
there be no further manual adjustment
thereof, once set initially for the first of
the Standard Rating Conditions
(Standard Rating Condition A). Absent
such instruction, the controls could be
adjusted as the test transitions through
the four Standard Rating Conditions
used for testing, which as discussed,
would not be representative of the
operation of the unit in the field. As
such, DOE has initially determined,
supported by clear and convincing
evidence, that absent instruction for the
control settings to be fixed during
testing, the industry test procedure
would not meet the statutory
requirements of 42 U.S.C. 6314(a)(2)–(3)
and is, therefore, proposing such
instruction.
Notwithstanding this proposal, DOE
recognizes that some manual
intervention, as permitted by AHRI 920–
2020, and as specified in supplemental
test instructions (STI),27 may be
necessary as the test transitions through
Standard Rating Conditions. However,
such manual interventions are only
permitted in limited and specific
instances as identified in the test
standard or STI. An example of such an
allowed intervention is the use of the
manual setting of compressor capacity
staging for tests using the ‘‘Weighted
average method,’’ as described in
section 6.9.1 of AHRI 920–2020. In field
operation, a DDX–DOAS set per the
manufacturer’s installation instructions
would attempt to achieve the target
supply air dew point over the average of
a time period with cycling (unsteady)
operation between two compressor
stages; to address this, the test standard
calls for manual intervention, using two
steady-state tests, one using each stage,
and calculating a weighted average of
the results. (This provision is discussed
in depth in section III.B.3.d.v of this
NOPR.)
Thus, DOE is proposing to require
that all control settings are to remain
unchanged for all Standard Rating
Conditions once system set-up has been
27 ‘‘STI’’ is defined in AHRI 920–2020 as
additional instructions provide by the manufacturer
and certified to the U.S. DOE. As explained in
section III.C.1 of this document, this NOPR does not
propose certification requirements for DDX–
DOAS—such requirements will instead be proposed
in a separate Energy Conservation Standard
rulemaking. Consistent with certification provisions
for other commercial packaged air-conditioning and
heating equipment, manufacturers include STI as
part of the certification (see 10 CFR 429.43(b)(4)).
DOE is proposing that manufacturers must adhere
to the provisions of this test procedure starting on
the compliance date for the related energy
conservation standard rulemaking. Hence, this
approach does not require that STI exist earlier than
the date it must be certified to DOE.
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completed, and component operation
shall be controlled by the unit under
test once the provisions in section 6 of
AHRI 920–2020 (Rating Requirements)
are met, except as specifically allowed
by the test standard or STI (see section
2.2.1(b)(i) of the proposed Appendix B).
Issue–7: DOE requests comment on
the proposed general control setting
requirement for DDX–DOASes.
h. Ventilation Energy Recovery Systems
As discussed in section III.A.1 of this
NOPR, the industry definition of ‘‘DXDedicated Outdoor Air System Units’’ is
inclusive of units that provide preconditioning of outdoor air by direct or
indirect transfer with return/exhaust air
using an enthalpy wheel, sensible
wheel, desiccant wheel, plate heat
exchanger, heat pipes, or other heat or
mass transfer apparatus. These preconditioning features are broadly
referred to as ventilation energy
recovery systems (‘‘VERS’’, or ‘‘energy
recovery’’). ASHRAE Standard 90.1–
2016 defines separate equipment classes
and efficiency levels for DDX–DOASes
with VERS.
Section 5.4 of AHRI 920–2020
specifies testing requirements for DDX–
DOASes equipped with VERS. Section
5.4.1 of AHRI 920–2020 specifies that
units equipped with VERS can be tested
using either one of two options: ‘‘Option
1’’ or ‘‘Option 2’’. Option 1 requires
operating the DDX–DOAS unit with
VERS as it would operate in the field,
maintaining the appropriate return air
and outdoor air conditions for airflows
entering the unit, and operating the
VERS to provide energy recovery during
the test (see section 5.4.1.1 of AHRI
920–2020).28 In addition to specifying
the outdoor air dry-bulb temperature
and humidity conditions, Table 4 and
Table 5 of AHRI 920–2020 specify
return air inlet conditions that are
applicable to DDX–DOASes with VERS.
Section C2.4 in Appendix C of AHRI
920–2020 also specifies that the return
air be ducted into the unit from a
separate test room maintaining the
required return air inlet conditions.
Option 2 involves setting the
conditions of the air entering the unit so
as to simulate the conditions that would
be provided by the VERS in operation
(see section 5.4.1.2 of AHRI 920–2020).
Option 2 uses energy recovery device
performance ratings based on ANSI/
28 The Option 1 test method includes additional
specificity to the test room configuration for testing
DDX–DOAS with energy recovery by allowing use
of the three-chamber approach in addition to the
example configuration provided in the current
industry consensus test standard, in which the
outdoor room is conditioned to both the required
outdoor dry-bulb and humidity conditions.
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AHRI 1060–2018 to calculate the air
dry-bulb temperature and humidity
conditions that would be provided by
the energy recovery device. ANSI/AHRI
1060–2018 references ANSI/ASHRAE
84–2013, ‘‘Method of Testing Air-to-Air
Heat/Energy Exchangers,’’ (ANSI/
ASHRAE 84–2013) (approved by
ASHRAE on January 26, 2013) for
conducting the test. These industry test
standards provide a method for rating
the performance of VERS in terms of
sensible and latent effectiveness. DOE
also notes that the performance ratings
for energy recovery devices certified
using ANSI/AHRI 1060–2018 are listed
in AHRI’s directory of certified product
performance.29
The operating conditions specified in
ANSI/AHRI 1060–2018 may be different
than the operating conditions specified
for testing DDX–DOAS (i.e., airflow rate,
which subsequently affects factors such
as transfer/leakage airflow 30). Hence,
section C4 of AHRI 920–2020 provides
methods to adjust, for the DDX–DOAS
operating conditions, the effectiveness
values for sensible and latent transfer
measured using ANSI/AHRI 1060–2018.
Section C4 of AHRI 920–2020 also
provides default values for sensible
effectiveness and latent effectiveness.
These can be used in cases where
performance rating information based
on ANSI/AHRI 1060–2018 is not
available for a VERS, or the rotational
speed for an energy recovery wheel has
been changed from the speed used to
determine performance ratings using
ANSI/AHRI 1060–2018.
The Option 2 approach would reduce
test burden for most test laboratories by
reducing the number of test rooms
required as compared to conducting
tests using Option 1. Because the
outdoor ventilation air and return air
would be maintained at the same
conditions, there would be no transfer
of heat or moisture in the VERS, nor any
change of VERS-outlet supply air
conditions associated with transfer or
leakage of return air to the supply air
plenum. In addition, testing using
Option 2 is conducted with all
components operating (e.g., with an
energy recovery wheel rotating, or with
the pump of a glycol-water runaround
loop activated), such that all
measurements would be representative
29 AHRI’s directory of certified product
performance for air-to-air energy recovery
ventilators can be found at www.ahridirectory.org/
ahridirectory/pages/erv/defaultSearch.aspx.
30 As discussed in section III.B.4.g.i of this NOPR,
DDX–DOASes with energy recovery wheel VERS
may experience air transfer and leakage from the
outdoor air path to the exhaust air (outdoor air
transfer and leakage) and return air to the supply
air (return air transfer and leakage).
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of the pressure drops and power
consumption associated with the VERS.
This approach avoids separate testing to
measure power input of auxiliary
components or of the exhaust air fan.
Option 2 is applicable for DDX–
DOASes for which a VERS provides the
initial outdoor ventilation air treatment.
DDX–DOAS units with VERS that
provide conditioning downstream of the
conditioning coil could not be tested
using Option 2, since this option
addresses VERS pre-conditioning only
upstream of the conditioning coil. Such
units would need to be tested using
Option 1.
In response to the July 2017 ASHRAE
TP RFI, AHRI commented that testing of
DDX–DOAS units with VERS would
generally require a facility with three
adjacent test chambers, which is not
available in the known stock of existing
laboratory spaces. (AHRI, No. 11 at p.
14) AHRI stated that the test facility
arrangement for testing of DDX–DOASes
with energy recovery presented in
ANSI/ASHRAE 198–2013,31 as
referenced by AHRI 920–2020, is not
adequate because laboratories cannot
maintain both the required dry-bulb
temperature and high humidity
conditions in the outdoor room, since
removing the high condenser heat load
using a conventional conditioning
system also excessively dehumidifies
the chamber. The commenter also
argued that capacity and stratification
are significant issues with the existing
test arrangement. AHRI surmised that a
separate, third test room to provide
conditioned outdoor air for the entering
air to the energy recovery device would
be required to provide adequate stability
for testing. AHRI further asserted that
because it is not feasible to adequately
test units with VERS, DOE should limit
the scope of the Federal test procedure
at this time to DDX–DOAS units
without VERS. (AHRI, No. 11 at p. 15)
Based on DOE’s review of the test
requirements and equipment available
on the market, DOE is aware of test
facilities capable of testing using Option
1 for smaller DDX–DOAS units. Test
facilities with similar configurations
used for testing variable refrigerant flow
multi-split air-conditioning and heat
pump equipment would be large enough
and equipped with enough controlled
test rooms to meet the DDX–DOAS test
procedure requirements. DDX–DOAS
units with physical dimensions under
10 feet by 10 feet (typically less than
100 lbs. per hour MRC at Standard
Rating Condition A), which represent
more than 50 percent of equipment
31 See section 6.1.1.2 and Figure 2 of ANSI/
ASHRAE 198–2013.
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models available on the market, could
be tested in these existing test facilities.
Option 2 allows existing test facilities
to test all DDX–DOAS units, including
units larger than those that can be tested
using Option 1. As discussed, Option 2
requires neither a separate third test
room to condition the outdoor
ventilation air to the required
temperature and humidity conditions,
nor that the outdoor room in which the
unit is located be conditioned to both
the required dry-bulb and humidity
conditions, because it does not require
use of an air stream at outdoor air
conditions. Aside from the chamber in
which the test unit is installed, it
requires only a second chamber at the
simulated conditions. The inclusion of
Option 2 in AHRI 920–2020 reduces
testing burden compared to the ANSI/
AHRI 920–2015, which only provides
test set-up and provisions that are
mostly equivalent to the Option 1
method in AHRI 920–2020 discussed
previously. For these reasons, DOE
tentatively concludes that existing test
facilities would be capable of using the
proposed test procedure for testing
DDX–DOASes both with and without
VERS.
DOE is required under EPCA to adopt
a Federal test procedure that is
consistent with the applicable test
procedure specified in the amended
ASHRAE Standard 90.1 unless DOE
determines, supported by clear and
convincing evidence, that to do so
would result in a test procedure that is
not designed to produce test results
which reflect the energy efficiency of
DDX–DOASes in a representative
average-use cycle or would be unduly
burdensome to conduct. (42 U.S.C.
6314(a)(4)(B); 42 U.S.C. 6314(a)(2) and
(3)) In this NOPR, DOE is proposing to
adopt the two options (i.e., Option 1 and
Option 2) for testing DDX–DOASes with
energy recovery, as provided in section
5.4.1 of AHRI 920–2020 (as enumerated
in section 2.2.1(b) of the proposed
Appendix B). As discussed further in
section III.B.3.a of this NOPR, DOE is
proposing to define a ‘‘ventilation
energy recovery system’’ as a feature
that provides pre-conditioning of
outdoor ventilation air entering the
equipment through direct or indirect
thermal and/or moisture exchange with
the exhaust air leaving the unit.
In addition, DOE notes that the
relevant industry test standards (AHRI
920–2020 and ASHRAE 198–2013) in
some cases use synonymous but
different terms to denote VERS. DOE
proposes to include a section 2.3(b) in
its proposed Appendix B indicating that
the different synonymous terms all refer
to VERS as defined in 10 CFR 431.92.
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The following subsections address
specific aspects of the proposed test
procedure pertaining to DDX–DOASes
with VERS.
i. Exhaust Air Transfer and Leakage
DOE is aware that DDX–DOASes with
energy recovery wheel VERS may
experience air transfer and leakage from
the outdoor air path to the exhaust air
(outdoor air transfer and leakage) and
return air to the supply air (return air
transfer and leakage). Some of this air is
leakage past the diametral seals that
separate the outdoor and exhaust
plenums on one side of the wheel and
the return and supply plenums on the
other side. Additional leakage from
outdoor to exhaust or return to supply
could be due to loose cabinet
construction of the DDX–DOAS itself.
Depending on the geometry of the
energy recovery wheel media (e.g.,
whether the sheets of media making up
the energy recovery wheel core are
oriented parallel to this leakage flow
direction), the air may pass through a
portion of the media near the diametral
seal. In addition, as a portion of the
wheel passes from one side of the seal
to the other, the air within that portion
reverses direction—this represents
either return air transferred to the
supply side or outdoor air transferred to
the exhaust side. The exhaust air
transfer ratio (EATR) is defined in
section 3.8 of AHRI 920–2020 as the
fraction of airflow leaving the VERS that
transfers or leaks from the return air
inlet rather than passing through the
VERS from the outdoor air inlet.
The return air that transfers and leaks
to the supply air side of an energy
recovery wheel did not enter the DDX–
DOAS as outdoor ventilation air.
Therefore, the amount of fresh outdoor
air delivered by the DDX–DOAS is less
than the supply airflow and is equal to
the supply airflow multiplied by the
factor (1–EATR). In addition, the return
air is already at neutral space
conditions. Hence, the energy recovery
wheel does not provide any meaningful
conditioning for this air. When
calculating MRC for a DDX–DOAS with
an energy recovery wheel, section 10.5
of ANSI/ASHRAE 198–2013 indicates
that the calculation is based on the full
supply airflow. DOE notes that any
transfer or leakage air would increase
the apparent dehumidification provided
by the DDX–DOAS unit, since this air is
already at space-neutral conditions—
thus, a high EATR would boost the
efficiency rating without providing any
real benefit (for VERS other than energy
recovery wheels, the EATR is
considered to be equal to 0, under the
assumption that cabinet air leakage
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through the VERS is negligible, so this
issue would not affect these other
VERS). ANSI/AHRI 920–2015 includes
tracer gas tests for measuring EATR in
its standard rating requirements (see
section 5.1). As part of the July 2017
ASHRAE TP RFI, DOE raised this issue,
while recognizing that such leakage may
be low enough in most energy recovery
wheels that the EATR measurement
could represent an unnecessary addition
to test burden. 82 FR 34427, 34437 (July
25 2017). DOE requested comment on
whether EATR should be included in
the test procedure for DDX–DOASes
and, if so, how it should be used in
determining DX–DOAS ratings. Id.
In response to the RFI, on this issue,
AHRI commented that the intent of the
DOE test procedure for DDX–DOASes
should not be to quantify energy
recovery performance. AHRI pointed
out that the AHRI certification directory
publishes EATR values based on AHRI
1060. (AHRI, No. 11 at p. 15) In
addition, AHRI argued that test
laboratories of sufficient size for testing
DDX–DOASes are not currently
equipped with tracer gas test
equipment, as specified in ANSI/
ASHRAE 84–2013. (AHRI, No. 11 at p.
14) No other comments were received
on this issue.
Since the July 2017 ASHRAE TP RFI,
further refinements were made to the
industry consensus test standard which
have bearing on this matter.
Specifically, sections 6 and C4 of AHRI
920–2020 were revised to include
methods to estimate EATR without
requiring a tracer gas measurement, and
to account for EATR’s impact on DDX–
DOAS performance, using calculations
tailored for testing under either Option
1 or Option 2. These include using an
EATR value that is based on testing in
accordance with ANSI/AHRI 1060–2018
with zero purge angle,32 zero return-tosupply pressure differential, and 100percent of nominal energy recovery
wheel supply airflow, and adjusting the
EATR value for the DDX–DOAS supply
airflow rate based on an assumption that
the leakage/transfer flow is not affected
by the supply and return air flow rates.
The adjusted value of EATR is then
used in the calculation of DDX–DOAS
performance. Specifically, the MRC
calculations in section 6.9 of AHRI 920–
2020 take into account the conditioning
32 A purge mechanism cleans the portion of the
wheel that has had contact with return air before
it is used to precondition outdoor air. The cleaning
is provided by outdoor air that passes through this
portion of the wheel and is diverted into the return
plenum to be discharged through the exhaust
blower. Most purge mechanisms allow adjustment
of the angle of the wheel sector that is subject to
this cleaning function. At zero purge angle, there is
no purge cleaning provided.
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of the air that leaked or transferred from
the return plenum to the supply plenum
(equal to adjusted EATR multiplied by
supply airflow) only from return
conditions to supply conditions to
reflect the fact that this air did not enter
the DDX–DOAS unit at outdoor air
conditions. In cases where EATR rating
information based on ANSI/AHRI 1060–
2018 is not available, or if, for an energy
recovery wheel, the rotational speed has
been changed from the speed used to
determine performance ratings using
ANSI/AHRI 1060–2018, sections 6.5 and
C4 of AHRI 920–2020 provide a default
value of EATR that would be used to
rate the DDX–DOAS.
DOE has tentatively determined that
the use of default or certified values for
EATR in AHRI 920–2020 (instead of
tracer gas tests) has addressed AHRI’s
comments on quantifying energy
recovery performance. Accordingly,
DOE is proposing to adopt these
changes made by AHRI 920–2020
(section 6.5 Determination of EATR), as
enumerated in section 2.2.1(c) of the
proposed Appendix B; and Appendix C
of AHRI 920–2020 (which includes
section C4 Simulated Ventilation Air
Conditions for Testing Under Option 2),
as enumerated in section 2.2.1(f) of the
proposed Appendix B).
ii. Purge Angle Setting
Section 6.6 of ANSI/ASHRAE 198–
2013 requires that for any DDX–DOAS
equipped with an energy recovery
wheel, the purge angle of such feature
must be set to zero when testing the
DDX–DOAS unit. As part of the July
2017 ASHRAE TP RFI, DOE requested
comment on whether all purge devices
are adjustable to zero purge and whether
it is always clear how to set them to zero
purge. 82 FR 34427, 34439 (July 25,
2017). DOE also requested comment on
whether it is appropriate to set purge to
zero or whether it would be more
appropriate to set purge to its highest
setting or to some other standard setting.
Id.
None of the comments on the RFI
indicated that there are purge devices
that are not adjustable to zero angle, nor
that it is unclear how to adjust purge
angle to zero. Carrier commented that
for the short period of time required for
a performance test, it should not be a
problem to set the purge angle to zero.
(Carrier, No. 6 at p. 8) As discussed
previously, AHRI stated that there are
no independent laboratories capable of
testing DDX–DOAS units with VERS. As
a result, AHRI argued that this issue
does not need to be addressed at this
time. However, AHRI stated, if in the
future laboratories are able to test DDX–
DOASes equipped with VERS, then
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manufacturers should be allowed to
specify the purge setting for testing, as
is done in AHRI 1060. (AHRI, No. 11 at
p. 20)
DOE has tentatively concluded that a
zero purge angle aligns with the
selection that manufacturers would
generally make (i.e., a zero purge angle),
because non-zero purge prevents the
purge portion of the wheel from
contributing to energy recovery
effectiveness (since outdoor ventilation
air passing through it is ejected out of
the unit to the exhaust rather than
becoming part of the supply airflow).
Also, the purge section restricts the flow
area for the remaining outdoor air that
becomes supply air, thus increasing
pressure drop and fan power. For these
reasons, energy recovery wheel
performance (and likewise DDX–DOAS
performance and efficiency) will be
reduced when operating with a non-zero
purge angle. Furthermore, basing DDX–
DOAS performance ratings on a zero
purge angle provides greater consistency
in testing. DOE notes that section C4.1
of AHRI 920–2020—the industry
consensus test standard—includes a
requirement for testing DDX–DOAS
units using zero purge angle, whether
testing using Option 1 or Option 2
(through inclusion of EATR0, which is
defined in section 11 of AHRI 920–2020
as being determined using zero purge
angle). For these reasons, DOE is
proposing to adopt the requirement in
AHRI 920–2020 to use a zero purge
angle for testing DDX–DOAS with
energy recovery wheels (section C4.1 of
Appendix C of AHRI 920–2020), as
enumerated in section 2.2.1(f) of the
proposed Appendix B.
iii. Return Air External Static Pressure
Requirements
ANSI/ASHRAE 198–2013 specifies
testing DDX–DOASes with VERS with
return air passing into the unit and
exiting at the exhaust air connection.
DOE noted in the July 2017 ASHRAE TP
RFI that ANSI/AHRI 920–2015 does not
address setting the external static
pressure (ESP) for the return airflow. 82
FR 34427, 34437 (July 25, 2017). DDX–
DOAS units are typically installed and
operated in the field with return air
ducting. Therefore, when in operation,
the return air fans consume additional
energy to overcome the static pressure
imposed by the return air ducts. As part
of the July 2017 ASHRAE TP RFI, DOE
requested comment on the ESP levels
that should be used for return airflow.
Id.
In response, AHRI stated that Table 4
of ANSI/AHRI 920–2015 was intended
to represent ESP of both supply and
return airflow. AHRI also stated that
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revisions to ANSI/AHRI 920–2015 will
refer to the same table for return airflow
ESP. (AHRI, No. 11 at p. 15) DOE
received no other comments on this
issue.
Consistent with the AHRI comment,
section 6.1.5.6 of AHRI 920–2020 does
include different ESP requirements for
supply and return airflow, thereby
resolving the identified issue.
Accordingly, DOE is proposing to adopt
the ESP requirements set forth in AHRI
920–2020 (section 6.1.5 Supply and
Return Airflow Rates), as enumerated in
section 2.2.1(c) of the proposed
Appendix B).
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iv. Target Return Airflow Rate
In the July 2017 ASHRAE TP RFI,
DOE noted that for testing DDX–DOAS
units equipped with VERS, Tables 2 and
3 in ANSI/AHRI 920–2015 provide
return airflow temperature conditions
and indicate that the temperature
conditions apply to units with energy
recovery at balanced airflow. 82 FR
34427, 34437 (July 25, 2017). It is
unclear from ANSI/AHRI 920–2015
what airflow streams should be
balanced, how to determine if they are
balanced, and within what tolerances
they should be balanced. In the July
2017 ASHRAE TP RFI, DOE requested
comments on which airflow streams
should be balanced and whether
balanced airflow is representative of
field use. Id.
On this topic, AHRI raised a number
of issues with testing DDX–DOAS
equipped with VERS generally, as
previously discussed. AHRI also stated
that using balanced airflows is
consistent with the test procedure for
rating VERS described in ANSI/AHRI
1060–2018. AHRI further commented
that in field operation, unbalanced
flows may be needed to maintain
positive building pressure; however,
most equipment selection is done at or
near balanced airflows. (AHRI, No. 11 at
pp. 14–15)
Subsequent updates to the industry
consensus test standard at AHRI 920–
2020 shed further light on this issue.
Specifically, section 6.1.5 of AHRI 920–
2020 specifies the return airflow rate
must be within 3 percent of the
measured supply airflow rate. Based on
DOE’s review of DDX–DOAS product
literature and consideration of the AHRI
comment, it has become apparent that
there is no clear optimal ratio of supply
airflow to return airflow for DDX–DOAS
testing to be representative of field use.
Therefore, DOE has tentatively
concluded that the provision in AHRI
920–2020 is appropriate.
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i. Demand-Controlled Ventilation
DDX–DOAS units are often used in
demand-controlled ventilation (DCV)
operation, which regulates the building
ventilation requirement based on
parameters such as building occupancy.
Typically, a DCV system monitors the
concentration of carbon dioxide (CO2) in
the return air or in the building and
regulates the supply airflow rate
accordingly. During periods of nonoccupancy, which could represent a
significant portion of field-use, the DCV
system controls the unit to operate at a
low airflow rate, thereby reducing the
unit’s overall energy use. DDX–DOASes
using DCV systems are typically
equipped with variable-speed supply
fans that can be adjusted to meet
changing ventilation needs. In the July
2017 ASHRAE TP RFI, DOE sought
comments on whether to include
operation under DCV conditions (i.e.,
low supply airflow conditions) to be
included as part of DOE’s test
procedure. 82 FR 34427, 34437 (July 25,
2017).
In response to this issue, the Joint
Advocates encouraged DOE to adopt an
efficiency metric that captures the
benefits of DCV. The Joint Advocates
stated that adopting such a metric could
provide more field-representative
equipment ratings and better inform
consumers when purchasing equipment.
Further, the Joint Advocates argued that
capturing the benefits of DCV would
promote adoption of variable speed
fans, provide more flexibility in
building operation, and reduce energy
use. (Joint Advocates, No. 9 at p. 2, 4)
AHRI and Carrier commented that the
performance of the DX–DOAS under
DCV operation must be characterized
prior to developing a test procedure and
that adopting provisions to address DCV
operation could significantly increase
the cost and complexity of testing. AHRI
further stated that DCV operation is
primarily controlled by building
operators. Carrier stated that
performance would depend highly on
the building type, occupancy, and site
requirements for demand ventilation.
(AHRI, No. 11 at p. 14; Carrier, No. 6 at
p. 4)
DOE reviewed the comments and
considered whether to adopt testing
conditions to account for the energy use
profiles of models with low supply
airflow rates that are typically
experienced by units with DCV.
Incorporation of the airflow modulation
that would be enabled by DCV might
provide more representative efficiency
ratings, help in consumer decision
making, and potentially promote the
market penetration of variable speed
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fans. However, DOE is not aware of
representative field data regarding the
typical DDX–DOAS duty cycle when
operating with DCV and, thus, agrees
with the comments of AHRI and Carrier
that characterization of DCV
performance would be an important first
step in integrating this control feature
into the test procedure. DOE further
agrees that adopting additional testing
requirements to capture the effect of
DCV could significantly increase testing
cost and complexity, as noted in
comments provided by AHRI and
Carrier. Given the lack of data on infield performance and the anticipated
additional testing burden of such a test,
DOE has tentatively decided not to
include performance under DCV
operation in its proposed test procedure
for DDX–DOASes at this time.
j. Tolerances for Supply and Return
Airflow and External Static Pressure
DOE noted in the July 2017 ASHRAE
TP RFI that Table 1 of ANSI/ASHRAE
198–2013 includes operating and
condition tolerances of 5 percent for
airflow rate. 82 FR 34427, 34439 (July
25, 2017). It includes a test operating
tolerance for ESP equal to 0.05 in H2O
and a test condition tolerance for ESP of
0.02 in H2O. As provided in section
5.2.2 of ANSI/AHRI 920–2015, the
airflow rate and ESPs are set at Standard
Rating Condition C dry-bulb
temperatures without the refrigeration
systems and energy recovery (if
applicable) in operation. ANSI/AHRI
920–2015 states in section 5.2.2.4 that
once the airflow rate is set, the fan
speeds shall not be adjusted for the
remaining tests. DDX–DOAS units that
are for use with air ducting are required
by the industry test standard to be set
up with ESP requirements in Table 4 of
ANSI/AHRI 920–2015, and units tested
as if they would be installed without
ducts are tested with 0 in H2O ESP.
DOE notes that while operating in
dehumidification mode, the airflow
rates and ESPs may fluctuate more than
for ‘‘dry’’ operation as condensate
accumulates and then drains from the
cooling coil. In addition, for
dehumidification and heating tests, the
density of supply air may be different,
which may change fan performance,
and, thus, the ESP. These factors could
cause the supply air ESP to fluctuate
more than the operating tolerances
specified in Table 1 of ANSI/ASHRAE
198–2013, and/or to deviate from the
specified ESP by more than the test
condition tolerance. Likewise, the
airflow rates could fluctuate more than
the specified operating tolerances, and
the average airflows could deviate by
more than the test condition tolerances
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from their target values. If this occurs,
it is not clear how manufacturers would
correct the issue without being able to
adjust the fan speed and ESP, since such
action is precluded by section 5.2.2.4 of
ANSI/AHRI 920–2015.
In the July 2017 ASHRAE TP RFI,
DOE noted that the 5-percent condition
tolerance on airflow rate is less stringent
than the 3-percent condition tolerance
adopted in DOE’s test procedure for
more typical commercial package air
equipment. 82 FR 344271, 34439 (July
25, 2017). On August 6, 2015, DOE
published a test procedure NOPR that
proposed to apply a ±5-percent
condition tolerance on cooling full-load
indoor airflow rate for more typical
commercial package air conditioning
equipment. 80 FR 46870, 46873. In
response to the proposed tolerance for
more typical commercial package air
conditioning equipment, DOE received
several comments suggesting that a 5percent tolerance would result in too
much variation in the measurement of
energy efficiency ratio and cooling
capacity. After considering stakeholder
comments, DOE adopted a 3-percent
tolerance in a final rule published on
December 23, 2015. 80 FR 79655,
79659–79660. As part of the July 2017
ASHRAE TP RFI, DOE expressed
concern that that the 5-percent
condition tolerance on airflow in ANSI/
ASHRAE 198–2013 may result in too
much test variability for DDX–DOASes
and requested comment on whether this
airflow tolerance is acceptable. 82 FR
34427, 34439 (July 25, 2017).
AHRI commented in response to the
July 2017 ASHRAE TP RFI that
manufacturers who have performed
testing have stated that meeting the
tolerances specified in ANSI/AHRI 920–
2015 and ASHRAE 198–2013 is not
feasible due to how the testing is
performed. Once the refrigeration
system is engaged for determining
ISMRE and ISCOP ratings, changes in
moisture present on the cooling coil and
air density affect the standard airflow
and associated ESP. AHRI
recommended that the ±0.05 in H2O ESP
tolerance and a 3-percent airflow
tolerance be observed during the airflow
and fan speed setting at Standard Rating
Condition C without the refrigeration
system operating. AHRI also stated that
during the Standard Rating Condition
tests, the DDX–DOAS fan speeds and
airflow-measuring apparatus fan speeds
shall not be adjusted, consistent with
airflow setting and operation in the
field. Nevertheless, AHRI stated that the
average measured airflows should be
required to be within 5 percent of the
manufacturer’s rated standard airflow
during all rating tests and that the
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average measured ESPs should be
within 15 percent of the required ESP to
indicate a valid test, but the commenter
did not indicate whether the fans of the
test unit or the airflow-measuring
apparatus should be adjusted to
maintain these tolerances. (AHRI, No.
11 at p. 18)
DOE notes that AHRI 920–2020
revised the test condition and operating
tolerances for airflow and ESP. Section
6.1.5 of AHRI 920–2020 specifies
airflow test condition tolerances of ±3
percent of the manufacturer-provided
airflow rate for all DDX–DOASes when
setting the airflow, provided that this
airflow rate meets the supply air dew
point temperature requirement, as
discussed in section III.B.4.d.i of this
NOPR. For setting the return airflow
rate, section 6.1.5 of AHRI 920–2020
specifies the same test condition
tolerances as for supply airflow rate,
except that for return airflow rate, the
target is equal to the measured supply
airflow rate. This specification ensures
that supply and return airflows remain
balanced, as discussed in section
III.B.3.h.iv of this NOPR. These test
condition tolerances for airflow and ESP
are only required when setting the
airflow. Once the airflow rate is set, the
dehumidification and heating tests are
then conducted without further
adjustments to the supply fan, return
fan, or airflow measuring apparatus.
Section 6.1.5 and Table 9 of AHRI 920–
2020 indicate that the supply and return
airflow and ESP condition tolerances
are not required to be maintained during
the dehumidification and heating tests.
While these provisions are contrary to
AHRI’s recommendation in response to
the July 2017 ASHRAE TP RFI to
impose a 5-percent airflow condition
tolerance and a 15-percent ESP
condition tolerance during
dehumidification and heating tests, DOE
believes these changes in AHRI 920–
2020 address AHRI’s concerns about
testing problems associated with the
tolerances in ANSI/AHRI 920–2015 and
ASHRAE 198–2013.
AHRI 920–2020 additionally includes
a list of test operating tolerances,
including those for external static
pressure and airflow nozzle differential
pressure. AHRI 920–2020 does not
include changes to the test operating
tolerance for ESP (0.05 in H2O total
observed range, specified in Table 9 of
AHRI 920–2020). Whereas ANSI/
ASHRAE 198–2013 provides a 5-percent
operating tolerance directly on the
airflow rate, Table 9 of AHRI 920–2020
provides a 5-percent operating tolerance
for airflow rate in the form of airflow
nozzle differential pressure. DOE has
initially determined that the airflow
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operating tolerance approach in AHRI
920–2020 is preferable because the
airflow nozzle differential pressure
provides a more direct indication of the
airflow variation, since airflow is
calculated based on this value.
Additionally, other industry test
standards such as ANSI/ASHRAE 37–
2009 include an operating tolerance on
the nozzle pressure drop rather than
directly on airflow. DOE believes that
these operating tolerances, in addition
to the condition tolerances for setting
airflow, would maintain repeatable and
reproducible results while ensuring that
testing is representative of field use.
Accordingly, DOE is proposing to adopt
the test condition and operating
tolerances for airflow and ESP specified
in AHRI 920–2020 (section 6.1.5 Supply
and Return Airflow Rates and section
6.6.2 Test Measurement Tolerances,
which contains Table 9), as enumerated
in section 2.2.1(c) of the proposed
Appendix B).
k. Secondary Dehumidification and
Heating Capacity Tests
Commercial package air-conditioners
and heat pumps with cooling capacity
less than 135,000 Btu/h are required to
undergo a secondary test to verify the
cooling or heating capacity and energy
efficiency results (see, e.g., ANSI/
ASHRAE 37–2009 section 7.2.1, which
is referenced by appendix A to subpart
F of 10 CFR part 431). Neither ANSI/
AHRI 920–2015 nor ANSI/ASHRAE
198–2013 specify a secondary test
method for verifying the
dehumidification and heating capacity
of DDX–DOAS, but section 6.7 of AHRI
920–2020 does specify secondary tests.
The measurement of dehumidification
and heating performance of DDX–
DOASes is based on measurements of
airflow rate, temperature, and humidity,
which have uncertainties associated
with them. Thus, a secondary test
method may be essential to confirm the
accuracy of the primary test method.
As part of the July 2017 ASHRAE TP
RFI, DOE requested comment on the
need for a secondary test method
requirement for DDX–DOAS testing. 82
FR 34427, 34439 (July 25, 2017). AHRI
commented that condensate
measurement would be appropriate as a
secondary method, if energy recovery
units are excluded from the test
procedure. (AHRI, No. 11 at p. 19)
Section C5.1 of AHRI 920–2020
includes a condensate-based test
method as a secondary measure of
dehumidification capacity. The method
measures the weight of the condensate
(i.e., water vapor in the outdoor
ventilation air that condenses on the
conditioning coil and is removed from
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the air) collected during the
dehumidification test and uses it to
calculate a secondary measure of MRC.
This secondary measure of MRC is then
compared to the primary MRC
measurement, which is based on supply
and outdoor ventilation airflow and air
condition measurements.
AHRI 920–2020 requires this
secondary measure of MRC for all
dehumidification tests, and comparison
to the primary measure of MRC at
Standard Rating Condition A. This
requirement is for all DDX–DOAS units
that: (a) Do not use condensate collected
from the dehumidification coil to
enhance condenser cooling or include a
secondary dehumidification process for
which the moisture removed from the
supply air stream is not collectable in
liquid form, and (b) either are not
equipped with VERS or are equipped
with VERS and tested using Option 2
(see section C5.1 of AHRI 920–2020).
AHRI 920–2020 does not require a
secondary dehumidification capacity
measurement for DDX–DOAS units
equipped with VERS that are tested
using Option 1. DOE understands that
this is because: (a) No viable method has
been developed and validated that
appropriately accounts for the water
vapor that transfers between air streams
of an energy recovery wheel, and (b) the
test burden of accounting for moisture
in the exhaust air stream would be
excessive. DOE is proposing to adopt
the secondary capacity test
measurements specified in AHRI 920–
2020 (section C5.1 Dehumidification
Capacity Verification), as enumerated in
section 2.2.1(f) of the proposed
Appendix B), including the cooling
condensate secondary test measurement
discussed previously.
For DDX–DOAS units with energy
recovery tested using Option 2, as
discussed in section III.B.3.h of this
NOPR, the test is conducted by setting
the conditions of the air entering the
unit (at both the outdoor air inlet and
return air inlet) to simulate the
conditions that would be provided by
the energy recovery device in operation.
As a result, the moisture removal (in
dehumidification mode) or heating (in
heating mode for heat pump DDX–
DOAS) measured during the Option 2
primary and secondary capacity tests
reflects only the moisture removed or
heating by the conditioning coil. The
MRC or qhp for the DDX–DOAS is
calculated by adjusting the measured
moisture removal or heating for the
primary test to account for the total
moisture removal or heating by the
energy recovery device and the
conditioning coil. Because the moisture
removal or heating capacity measured
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for the primary and secondary tests are
based on the simulated test conditions,
sections 6.9 and 6.10 of AHRI 920–2020
use these measured values for the
secondary capacity verification under
Option 2. DOE is proposing to adopt
these requirements specified in AHRI
920–2020 (section 6.9 Moisture Removal
Efficiency Ratings and section 6.10
Heating Capacity), as enumerated in
section 2.2.1(c) of the proposed
Appendix B).
a. Corrections
In addition to substantive changes,
AHRI 920–2020 also provides minor
corrections to instructions in ANSI/
AHRI 920–2015. However, in its review
of AHRI 920–2020, DOE identified an
error and an omission in the latest
industry test procedure. Specifically,
DOE notes that section 6.9.2 of AHRI
920–2020 provides erroneous
instruction for the calculation of the
degradation coefficient, and sections
6.1.5.2.3 and 6.1.5.2.4 of AHRI 920–
2020 refer to the term ‘‘non-standard
low-static motor’’ without providing a
definition or explanation of this term.
DOE proposes to correct the calculation
instruction and define the term ‘‘nonstandard low-static motor,’’ as discussed
further in the following paragraphs.
DOE also notes a correction made by
AHRI 920–2020 to address an error in
the calculation of supplementary heat
penalty in ANSI/AHRI 920–2015.
i. Calculation of the Degradation
Coefficient
As mentioned in section III.B.3.d.v of
this NOPR, AHRI 920–2020 includes
provisions for cases where the unit
provides excess dehumidification or
heating capacity when operating at its
lowest-capacity compressor stage. A
degradation coefficient is applied to the
MRE and MRE70 when the supply air
dew point temperature measured when
operating the unit at its lowest-capacity
compressor stage is lower than the target
supply air dew point temperature in
excess of the specified test condition
tolerance. This degradation coefficient
accounts for the re-evaporation of
condensate which occurs during cycling
operation (i.e., when the compressor
cycles on and off to achieve the target
supply air dew point temperature). DOE
understands that the degradation is
more pronounced for DDX–DOASes
equipped with VERS for latent energy
recovery (or total energy recovery), and,
thus, the degradation coefficient should
be greater for DDX–DOASes operating
total energy recovery VERS. Equation 20
in section 6.9.2 of AHRI 920–2020
appears to incorrectly attribute the
lower degradation coefficient to DDX–
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DOASes operating with VERS. As such,
DOE has initially determined, supported
by clear and convincing evidence, that
absent a correction, the degradation
coefficient as applied in AHRI 920–2020
would not meet the statutory
requirements of 42 U.S.C. 6314(a)(2)–(3)
because it would not produce
representative results. DOE proposes to
correct Equation 20 by specifying that it
is to be used for DDX–DOASes ‘‘without
VERS, with deactivated VERS (see
section 5.4.3 of AHRI 920–2020), or
with sensible-only VERS tested under
Standard Rating Conditions other than
D’’ (emphasis added) because DDX–
DOASes with total energy recovery
VERS or with sensible-only VERS tested
under Standard Rating Condition D are
considered separately in Equation 21,
which calculates a greater degradation
coefficient. This correction would be
implemented in section 2.2.1(c)(iii) of
proposed Appendix B.
ii. Non-Standard Low-Static Motor
As mentioned in section III.B.3.d.i of
this NOPR, section 6.1.5 of AHRI 920–
2020 includes instructions for setting
the supply airflow rate for testing. In
particular, sections 6.1.5.2.1 through
6.1.5.2.5 of AHRI 920–2020 provide
directions for adjusting the fans should
an initial attempt at setting the airflow
be unsuccessful.
Section 6.1.5.2.3 of AHRI 920–2020
specifies that if a fan’s maximum speed
is too low to satisfy the airflow and
external static pressure requirements
within tolerance (i.e., the motor speed is
at the highest setting, a larger
compatible off-the-shelf sheave is not
available, or increased speed would
overload the motor or motor drive) and
the motor is not a ‘‘non-standard lowstatic motor,’’ the tests are to be
conducted at the fan’s maximum speed
with the external static pressure
satisfying the requirements in Table 7.
However, if the motor is a ‘‘nonstandard low-static motor,’’ section
6.1.5.2.4 of AHRI 920–2020 specifies
that the maximum available speed
should be used but the supply and
return airflow rates should satisfy
aforementioned tolerance requirements
(implying that the external static
pressure requirements in Table 7 need
not be met). AHRI 920–2020 does not
define ‘‘non-standard low-static motor’’
in order to determine which of the two
methods is appropriate. Without a
definition of ‘‘non-standard low-static
motor,’’ manufacturers may not apply
the ‘‘maximum speed’’ provisions
consistently, and the potential for
variation risks results that do not reflect
the equipment’s representative average
energy efficiency or energy use. As
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such, DOE has initially determined,
supported by clear and convincing
evidence, that in the absence of a
definition of ‘‘non-standard low-static
motor,’’ the industry test procedure
would not meet the statutory
requirements of 42 U.S.C. 6314(a)(2)–
(3).
DOE understands that a non-standard
low-static fan motor may be used for
DDX–DOASes where the application
requires less ductwork, which results in
a lower external static pressure when
operating at the same nominal supply or
return airflow rate. This motor would be
distributed in commerce as part of an
individual model within the same basic
model of DDX–DOAS that is also
distributed in commerce with a motor
that can meet the external static
pressure required by AHRI 920–2020. A
parallel situation occurs for Commercial
and Industrial Unitary Air-conditioning
and Heat Pump Equipment, for which
section D3 in Appendix D of AHRI Test
Standard 340/360–2019, ‘‘Performance
Rating of Commercial and Industrial
Unitary Air-conditioning and Heat
Pump Equipment’’ (AHRI 340/360–
2019) defines ‘‘non-standard motor’’ as
an indoor fan motor that is not the
standard indoor fan motor and that is
distributed in commerce as part of an
individual model within the same Basic
Model. The same section D3 defines
‘‘standard indoor fan motor’’ as the
motor specified by the manufacturer for
testing and shall be distributed in
commerce as part of a particular model.
In both cases, the non-standard motor
has a horsepower level that is not
compatible with the external static
pressure rating condition—for DDX–
DOAS, the issue arises when the nonstandard motor does not have sufficient
power to deliver the required external
static pressure. Therefore, in the
proposed Appendix B in section
2.2.1(a)(i), DOE is proposing to define
‘‘non-standard low-static fan motor’’ as
a supply fan motor that cannot maintain
external static pressure as high as
specified in Table 7 of AHRI 920–2020
when operating at a manufacturerspecified airflow rate and that is
distributed in commerce as part of an
individual model within the same basic
model of a DDX–DOAS that is
distributed in commerce with a different
motor specified for testing that can
maintain the required external static
pressure.
Issue–8: DOE is requesting comment
on the proposed definition of ‘‘nonstandard low-static fan motor’’ and
whether the proposed definition reflects
stakeholder understanding of the term.
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iii. Calculation of Supplementary Heat
Penalty
Section 6.1.3.1 of ANSI/AHRI 920–
2015 includes a supplementary heat
penalty for units that are unable to
achieve the minimum supply air drybulb temperature of 70 °F while testing
at each Standard Rating Condition
specified in Table 2 and Table 3 of
ANSI/AHRI 920–2015. The
supplementary heat penalty calculates
the difference in enthalpy from the
delivered supply air and air at the
minimum supply air temperature
(70 °F). After reviewing the equations,
DOE noted in the July 2017 ASHRAE TP
RFI that the term for supply airflow rate
is missing from the supplementary heat
penalty equations. 82 FR 34427, 34436
(July 25, 2017).
In response to the July 2017 ASHRAE
TP RFI, AHRI confirmed that the
supplementary heat formula in ANSI/
AHRI 920–2015 is missing the airflow
term, QSA, in section 6.1.3.1, and the
organization committed to include such
term in the next revision of the test
standard. (AHRI, No. 11 at p. 11) DOE
notes that this change has been included
in AHRI 920–2020, thereby resolving
the problem. Accordingly, DOE
proposes to adopt the revised
supplementary heat penalty equation
contained in AHRI 920–2020 that
includes the supply airflow rate term
(section 6.1.3.1 Initial Standard Rating
Condition A Dehumidification Test), as
enumerated in section 2.2.1(c) of the
proposed Appendix B).
In the July 2017 ASHRAE TP RFI,
DOE further noted that section 6.1.3.1 of
ANSI/AHRI 920–2015 calls for a
supplementary heat penalty if the
supply air temperature is less than
70 °F, but the incorporation of this
penalty into the MRE and COP
equations is not clearly described. DOE
also noted that it is not clear whether
the ANSI/ASHRAE 198–2013 test
method considers this penalty. 82 FR
34427, 34436–34437 (July 25, 2017).
AHRI commented that the
supplementary heat penalty should be
added if the minimum 70 °F
temperature is not met, and that this
value is added to the measured power
input, which is represented as PT in
section 10.6 of ANSI/ASHRAE 198–
2013. (AHRI, No. 11 at p. 11) DOE notes
that this clarification is included in
section 6.9 of AHRI 920–2020 in the
calculation of MRE70, which
incorporates the energy impact of
heating the supply air to 70 °F. As
discussed in section III.B.2 of this
NOPR, DOE is proposing to adopt the
ISMRE2 metric specified in section 6.13
of AHRI 920–2020 that does not include
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the supplementary heat penalty as the
regulated metric for DDX–DOAS, while
the MRE70 (and ISMRE270) metric that
incorporates the supplementary heat
penalty may be used for representations.
As a result, the supplementary heat
penalty would only be added to the total
power input for the calculation of the
optional MRE70 ratings.
With regards to the COP calculation,
AHRI commented that the intent was
that the supplementary heat penalty
would be added to the numerator as
additional heat capacity and the
denominator as additional power
consumed to calculate a COP indicative
of running an electric heater to meet a
supply air temperature of 70 °F. (AHRI,
No. 11 at p. 13) DOE notes that this
clarification was included in section
6.11.2 of AHRI 920–2020 in the
renamed COPISCOP metric, and
accordingly, DOE is proposing to adopt
the revised COPISCOP calculation
(section 6.11.2 of AHRI 920–2020), as
enumerated in section 2.2.1(c) of the
proposed Appendix B).
2. Determination of Represented Values
a. Basic Model
To determine the energy efficiency of
a basic model, DOE’s certification
requirements generally require
manufacturers to test a sample of units
of that basic model to represent its
performance. (10 CFR 429.11) The basic
model may include multiple individual
models having similar performance
features and characteristics. Typically,
DOE provides a definition of a basic
model for each type of covered
equipment. In this NOPR, DOE proposes
a definition for DDX–DOAS basic model
derived from the basic model definition
for other commercial packaged air
conditioning and heating equipment set
forth at 10 CFR 431.92. Specifically,
DOE replaced the criterion to have
common nominal cooling capacity with
common nominal MRC. DOE is also
proposing to include the common
nominal MRC in the definition of a
basic model for small, large and very
large air-cooled or water-cooled
commercial package air conditioning
and heating equipment, which includes
DDX–DOASes. The proposed definition
of basic model of a DDX–DOAS also
specifies that a basic model must
include units with similar VERS
equipment. DOE is proposing in this
specification to reflect that ASHRAE
Standard 90.1 delineates DDX–DOAS
equipment classes, in part, based on
VERS, and the proposed test procedure
considers the conditioning contribution
of the VERS equipment.
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DOE is proposing that a basic model
for a DDX–DOAS means all units
manufactured by one manufacturer
within a single equipment class; with
the same or comparably performing
compressor(s), heat exchangers,
ventilation energy recovery system(s) (if
present), and air moving system(s), and
with a common ‘‘nominal’’ moisture
removal capacity. This proposed
definition of a basic model of a DDX–
DOAS would be included in the
regulatory text in 10 CFR 431.92.
Issue–9: DOE seeks comment on the
proposed definition of basic model of a
DDX–DOAS.
b. Sampling Plan Requirements
DOE is proposing sampling
requirements to determine the
represented values for DDX–DOAS (i.e.,
dehumidification and heating
efficiencies and MRC). More
specifically, by proposing to define (at
10 CFR 431.92) DDX–DOAS as a subset
of DX–DOAS, and to define DX–DOAS
as a category of small, large, or very
large commercial package air
conditioning and heating equipment,
the proposal would apply the same
sampling requirements to DDX–DOASes
as applicable to other commercial
package air conditioning and heating
equipment under 10 CFR 429.43,
Commercial heating, ventilating, air
conditioning (HVAC) equipment.
In response to DOE’s request for
general comment on issues associated
with adopting the industry test
procedures for certain commercial
package air conditioning and heat pump
equipment in the July 2017 ASHRAE TP
RFI (82 FR 34427, 34445 (July 25,
2017)), Lennox recommended that DOE
harmonize the certification criteria for
commercial HVAC equipment in 10 CFR
429.43 with those for central air
conditioners, a consumer product, in 10
CFR 429.16. In particular, Lennox stated
that commercial equipment currently
has a more stringent confidence limit of
95 percent, but the commenter argued
that current testing technology does not
support this level of precision. (Lennox,
No. 8 at p. 6) As DOE is proposing to
apply the sampling requirements of 10
CFR 431.43 to DDX–DOASes, Lennox’s
comment regarding the confidence limit
for represented values of energy
efficiency, energy consumption, and
capacity is relevant to DDX–DOASes.
Other manufacturers did not raise
concerns regarding the confidence limit
required for sampling more typical
commercial package air conditioning
and heat pump equipment, and Lennox
has not provided data regarding
variability of units in production and
testing. Absent more specific
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information or data regarding the
stringency of the confidence level, DOE
is not proposing a change.33
Issue–10: DOE requests comment on
the sampling plan proposed for DDX–
DOASes. DOE specifically requests
information and data regarding the
proposed confidence level and whether
variability of testing of DDX–DOASes
would require a less stringent level, and
if so, what that level should be.
c. Multiple Refrigerants
DOE recognizes that some commercial
package air conditioning and heating
equipment may be sold with more than
one refrigerant option (e.g., R–410A or
R–407C). Typically, manufacturers
specify a single refrigerant in their
literature for each unique model, but in
its review, DOE has identified at least
one commercial package air
conditioning and heating equipment
manufacturer that provides two
refrigerant options under the same
model number. The refrigerant chosen
by the customer in the field installation
may impact the energy efficiency of a
unit. For this reason, DOE is proposing
representation requirements specific for
models approved for use with multiple
refrigerants.
Use of a refrigerant that requires
different hardware (such as R–407C as
compared to R–410A) would represent a
different basic model, and according to
the current CFR, separate
representations of energy efficiency are
required for each basic model. On the
other hand, some refrigerants (such as
R–422D and R–427A) would not require
different hardware, and a manufacturer
may consider them to be the same basic
model. In the latter case of multiple
refrigerant options, DOE proposes to
add a new paragraph at 10 CFR
429.43(a)(3) specifying that a
manufacturer must determine the
represented values for that basic model
based on the refrigerant(s)—among all
refrigerants listed on the unit’s
nameplate—that result in the lowest
ISMRE2 and ISCOP2 efficiencies,
respectively. For example, the
dehumidification performance metric
ISMRE2 must be based on the
refrigerant yielding the lowest ISMRE2,
and the heating performance metric
ISCOP2 (if the unit is a heat pump
DDX–DOAS) must be based on the
33 DOE notes that it has previously requested data
regarding the variability of units of small, large, and
very large air-cooled commercial package air
conditioning and heating equipment in production
and testing to enable DOE to review and make any
necessary adjustments to the specified confidence
levels. See 80 FR 79655, 79659 (Dec. 23, 2015).
However, DOE did not receive any relevant data in
response to that request.
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refrigerant yielding the lowest ISCOP2.
These represented values would apply
to the basic model for all refrigerants
specified by the manufacturer as
appropriate for use, regardless of which
one may actually be used in the field,
where only one set of values is reported.
DOE notes that this proposal reflects
the proposed definition of basic model
for DDX–DOASes as discussed in
section III.B.4.a of this NOPR. Units
within a basic model of DDX–DOAS
must have the same or comparably
performing compressor(s), heat
exchangers, ventilation energy recovery
system(s) (if present), and air moving
system(s), and with a common
‘‘nominal’’ moisture removal capacity.
Issue–11: DOE requests comment on
its proposal regarding representations
for models approved for use with
multiple refrigerants.
d. Alternative Energy-Efficiency
Determination Methods
DOE proposes to allow DDX–DOAS
manufacturers to use alternative energyefficiency determination methods
(AEDMs) for determining the ISMRE2
and ISCOP2 (if applicable) in
accordance with 10 CFR 429.70. By
proposing to define (at 10 CFR 431.92)
DDX–DOAS as a subset of DX–DOAS,
and to define DX–DOAS as a category of
small, large, or very large commercial
package air conditioning and heating
equipment, the provisions of 10 CFR
429.43 authorizing use of an AEDM for
commercial HVAC equipment would
apply to DDX–DOAS. DOE notes that
the proposed requirements for use of
AEDMs to determine DDX–DOAS
represented values are consistent with
AEDM requirements for all other
categories of commercial package airconditioning and heating equipment.
DOE proposes to create four
validation classes of DDX–DOASes
within the Validation classes table at 10
CFR 429.70(c)(2)(iv): Air-cooled/airsource and water-cooled/water-source,
each with and without VERS. The
separation into air-cooled/air-source
and water-cooled/water source
validation classes is the same approach
used for other categories of commercial
package air-conditioning and heating
equipment. For DDX–DOASes, the
additional class separation by presence
of energy recovery reflects ASHRAE
Standard 90.1 delineating equipment
classes, in part, based on the presence
of VERS and the significant differences
in the test methods required with energy
recovery. These differences in the test
procedures include the potential need
for a third test chamber for the Option
1 approach for testing DDX–DOASes
with energy recovery, and the
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requirement to account for the
performance of the energy recovery
device for the Option 2 approach (see
section III.B.3.g of this NOPR).
DOE proposes to require testing of
two basic models to validate the AEDMs
for each validation class—this is
identical to the requirements for other
categories of commercial package airconditioning and heating equipment.
Finally, DOE proposes to specify in the
table at 10 CFR 429.70(c)(5)(vi) a
tolerance of 10 percent for DDX–DOAS
verification tests for ISMRE2 and
ISCOP2 when comparing test results
with certified ratings. Again, this is
identical to the tolerances for
‘‘integrated’’ ratings for other categories
of commercial package air-conditioning
and heating equipment.
Issue–12: DOE requests comment on
its proposals for AEDM requirements for
DDX–DOAS equipment. DOE requests
comment specifically on whether the
proposed 10-percent tolerance for
comparison of test results with rated
values is appropriate. If the 10-percent
tolerance is not appropriate, DOE
requests comment on why it is not
appropriate, as well as comment
indicating an appropriate tolerance.
e. Rounding
Sections 6.1.2.1 through 6.1.2.8 of
AHRI 920–2020 specify rounding for
DDX–DOAS performance metrics. DOE
proposes to adopt these rounding
requirements as part of the DOE test
procedure, as enumerated in section
2.2.1(c)(iv) of the proposed Appendix B.
Issue–13: DOE requests comment on
its proposal to adopt the rounding
requirements for key metrics as
specified in sections 6.1.2.1 through
6.1.2.8 of AHRI 920–2020.
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3. Configuration of Unit Under Test
DOE recognizes that DDX–DOASes
are distributed in commerce in a variety
of configurations consisting of different
combinations of components. DOE
proposes in section 2.2.1(g) of Appendix
B to adopt the requirements of appendix
F to AHRI 920–2020, which includes a
list of components that must be present
for testing DDX–DOASes and a list of
components that are optional for testing.
Appendix F in AHRI 920–2020 also
includes explicit instructions on how
representations can be made for
equipment that include these optional
components. AHRI 920–2020 specifies
the following list of components that
must be present for testing:
• Supply air filter(s);
• Compressor(s);
• Outdoor coil(s) or heat
exchanger(s);
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• Outdoor coil fan(s)/motor(s) (for aircooled and air-source systems only);
• Conditioning coil(s);
• Refrigerant expansion device(s);
• Supply/outdoor ventilation fan(s)/
motor(s), and
• System controls.
AHRI 920–2020 also specifies that for
supply air filters, the filter shall have a
‘‘minimum efficiency reporting value’’
(MERV) specification no less than
MERV 8. For individual models that use
filters with efficiency higher than MERV
8 (which generally have higher pressure
drop and could reduce relative tested
efficiency), section F2.4 of AHRI 920–
2020 allows manufacturers the option of
testing these individual models as a
separate basic model or combined into
a basic model with other individual
models that meet the basic model
definition and are tested with a MERV
8 filter. Adopting Appendix F of AHRI
920–2020 without changes would allow
manufacturers to provide efficiency
representations based on either testing
option for individual models that use
filters with efficiency higher than MERV
8.
DOE notes that the list of components
that are optional for testing specified in
section F2.4 of AHRI 920–2020 includes
features that may reduce tested
efficiency but may also in certain
applications: (a) Maintain or improve
field efficiency or (b) be required for
safety. Given the potential benefits, DOE
does not want to penalize equipment
with such components, because that
might disincentivize their adoption. By
proposing to adopt Appendix F of AHRI
920–2020 without changes, the
following instructions from AHRI 920–
2020 would specify how to make
representations for individual models of
equipment that include these optional
features:
• Individual models with features
designated as ‘‘optional’’ may be
represented separately as a unique basic
model or certified within the same basic
model as otherwise identical individual
models without the feature pursuant to
the definition of ‘‘basic model’’ in
§ 431.92.
• If an otherwise identical model
(within the same basic model) without
the feature is distributed in commerce,
test the otherwise identical model.
• If an otherwise identical model
(within the same basic model) without
the feature is not distributed in
commerce, conduct tests with the
feature present but configured and deactivated so as to minimize (partially or
totally) the impact on the results of the
test. Alternatively, the manufacturer
may indicate in the supplemental
testing instructions that the test shall be
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conducted using a specially-built
otherwise identical unit that is not
distributed in commerce and does not
have the feature.
This approach ensures that equipment
distributed in commerce with additional
components outside the list of required
components are still within the scope of
the test procedure. The proposed
approach also provides instruction on
how to make representations for all
component combinations (including
those with optional components). In
addition, this approach allows
manufacturers the flexibility to make
representations of equipment with
components designated as ‘‘optional’’
based on testing otherwise identical
individual models without the feature.
C. Other Comments
In response to the July 2017 ASHRAE
TP RFI, DOE received several general
comments not specific to any one
equipment category or test procedure.
This section addresses those comments.
NCI recommended that DOE follow
the development of ASHRAE 221P,
‘‘Test Method to Measure and Score the
Operating Performance of an Installed
Constant Volume Unitary HVAC
System,’’ and consider where it may be
appropriately applied within EPCA test
procedures. (NCI, No. 4 at pp. 1–2) NCI
stated that it has collected data
indicating that typical split systems and
packaged units serving residential and
small commercial buildings typically
deliver 50 percent to 60 percent of the
rated capacity to the occupied zone,
thereby making laboratory tests
unrepresentative of field performance.
(Id.)
As noted in section I.A of this
document, EPCA prescribes that the test
procedures for commercial package air
conditioning and heating equipment
must be those generally accepted
industry testing procedures or rating
procedures developed or recognized by
industry as referenced in ASHRAE
Standard 90.1. (42 U.S.C. 6314(a)(4)(A))
DOE notes that ASHRAE Standard 90.1
does not reference ANSI/ASHRAE
Standard 221–2020, ‘‘Test Method to
Field-Measure and Score the Cooling
and Heating Performance of an Installed
Unitary HVAC System’’ 34 (ASHRAE
221–2020) as the applicable test
procedure corresponding to industry
standards. NCI also did not provide data
on field performance or any correlations
between field performance and
laboratory test performance for DX–
DOASes or DDX–DOASes for DOE to
34 Available at: webstore.ansi.org/tandards/
ASHRAE/ANSIASHRAEStandard2212020 (Last
accessed April 19, 2021).
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consider. Furthermore, ASHRAE 221–
2020 does not provide a method to
determine the dehumidification
efficiency and heating efficiency of
DDX–DOASes, as AHRI 920–2020 does.
As discussed in section II of this
document, DOE is proposing to
incorporate by reference AHRI 920–
2020 (i.e., the test procedure recognized
by ASHRAE Standard 90.1 for DDX–
DOASes) and the relevant industry
standards referenced therein, consistent
with EPCA requirements.
The CA IOUs commented that while
the July 2017 ASHRAE TP RFI
expressed interest in reducing burden to
manufacturers, DOE already took steps
to reduce burden by allowing alternative
energy efficiency or energy use
determination methods (AEDMs). (CA
IOUs, No. 7 at pp. 1–2) The CA IOUs
stated that there are no further
opportunities to streamline test
procedures to limit testing burden. (Id.)
Additionally, the CA IOUs emphasized
the importance of accurate efficiency
ratings for its incentive programs and
customer knowledge, pointing to the
statutory provision that test procedures
must produce results that are
representative of the product’s energy
efficiency. (Id.)
Lennox stated that it generally
supports DOE meeting the statutory
requirements to design test procedures
to measure energy efficiency during an
average use cycle but requested that
DOE also consider overall impacts to
consumers and manufacturers. (Lennox,
No. 8 at pp. 1–2) The commenter stated
that in commercial applications,
predicting actual energy use from a
single metric is difficult and that a
metric better serves as a point of
comparison. (Id.) Lennox suggested that
DOE strike a balance between evaluating
equipment in a meaningful way without
introducing regulatory burden from
overly complex test procedures or
calculations that provide little value to
consumers. (Id.)
In response to the CA IOUs and
Lennox, DOE notes that its approach to
test procedures is largely dictated by the
requirements of EPCA. As discussed,
EPCA prescribes that the test procedures
for commercial package air conditioning
and heating equipment must be those
generally accepted industry testing
procedures or rating procedures
developed or recognized by industry as
referenced in ASHRAE Standard 90.1.
(42 U.S.C. 6314(a)(4)(A)) If such relevant
industry test procedure is amended,
DOE must update its test procedure to
be consistent with the amended
industry consensus test procedure,
unless DOE determines, by rule
published in the Federal Register and
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would be representative of an average
use cycle and would not be unduly
burdensome for manufacturers to
conduct. To the extent that DOE is
proposing modifications to the industry
consensus test procedure, DOE has
tentatively determined that the
proposed modifications are consistent
with the industry consensus standard,
and as explained in the prior sections,
they are supported by clear and
convincing evidence, because absent
such modifications, the industry test
procedure would not meet the
requirements in 42 U.S.C. 6314(a)(2)
and (3) related to representative use and
test burden. (42 U.S.C. 6314(a)(4)(B) and
(C)). Further, DOE has tentatively
determined that the proposed
modifications would be unlikely to
significantly increase burden, given that
DOE is referencing the prevailing
industry test procedure. So, presuming
widespread usage of that test standard,
its adoption as part of the Federal test
procedure would be expected to result
in little additional cost, even with the
minor modifications proposed here.
DOE has tentatively determined that the
test procedure, if finalized as proposed,
would not require manufacturers to
redesign any of the covered equipment,
would not require changes to how the
D. Test Procedure Costs, Harmonization, equipment is manufactured, and would
not impact the utility of the equipment.
and Other Topics
When the industry test procedure or
1. Test Procedure Costs and Impact
rating procedure for a category of small,
large, and very large commercial
EPCA requires DOE to adopt test
package air conditioning and heating
procedures for small, large and very
equipment recognized in ASHRAE
large commercial package air
Standard 90.1 is amended, DOE is
conditioning and heating equipment
required to amend the Federal test
consistent with the amended industry
test procedures developed or recognized procedure for the relevant category of
small, large, and very large commercial
AHRI as referenced in ASHRAE
package air conditioning and heating
Standard 90.1, unless the Secretary
determines that, supported by clear and equipment consistent with the industry
convincing evidence, to do so would not update, unless DOE determines by clear
and convincing evidence that to do so
meet the requirements for test
procedures to be reasonably designed to would result in a test procedure that
does not meet the EPCA requirements
produce results that reflect energy
regarding representativeness and testing
efficiency, energy use, and estimated
burden. (42 U.S.C. 6314(a)(4)(B)) As
operating costs during a representative
discussed, ASHRAE Standard 90.1–
average use cycle and not be unduly
2016 established energy efficiency
burdensome to conduct. (42 U.S.C.
levels for DDX–DOASes (but written as
6314(a)(4)(B)) In this NOPR, DOE
‘‘DX–DOASes’’ in ASHRAE Standard
proposes to establish a test procedure
90.1) as a category of commercial
for DDX–DOASes, which belong to a
package air conditioning and heating
category of small, large, and very large
equipment and recognized ANSI/AHRI
commercial package air conditioning
920–2015 as the industry test procedure
and heating equipment. DOE is
for these equipment. Subsequent to the
proposing to establish a test procedure
establishment of standards and a test
that incorporates by reference the
procedure for DDX–DOASes in
applicable industry consensus test
ASHRAE Standard 90.1–2016, ANSI/
methods (including the energy
AHRI 920–2015 was updated. The 2020
efficiency descriptors) and that
establishes representation requirements. version of AHRI 920 (i.e., AHRI 920–
2020) is the most recent version of the
DOE has tentatively determined that
industry test procedure for DDX–
these proposed new test procedures
supported by clear and convincing
evidence, that the amended test
procedure would not meet the
requirements in 42 U.S.C. 6314(a)(2)
and (3) related to representative use and
test burden. (42 U.S.C. 6314(a)(4)(B) and
(C)) In establishing or amending its test
procedures, DOE must develop test
procedures that are reasonably designed
to produce test results which reflect
energy efficiency, energy use, and
estimated operating costs of a type of
industrial equipment during a
representative average use cycle and
that are not unduly burdensome to
conduct. (42 U.S.C. 6314(a)(2)) DOE’s
considerations of these requirements in
relation to individual test method issues
are discussed within the relevant
sections of this NOPR.
The Joint Advocates stated that there
are a number of ambiguities in industry
test procedures and that DOE should
address these ambiguities in order to
provide a level playing field for
manufacturers and to ensure that any
verification or enforcement testing is
consistent with manufacturers’ own
testing. (Joint Advocates, No. 9 at p. 2)
In the context of a test procedure for
DDX–DOASes, DOE addresses the
potential for ambiguity as applicable, in
the previous sections of this document.
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DOASes (still referred to in AHRI 920–
2020 as simply ‘‘DX–DOASes’’).
DOE is proposing to incorporate by
reference the revised industry test
standard, AHRI 920–2020, with certain
modifications that are consistent with
the industry test standard. DOE has
tentatively concluded that the proposed
test procedure in this NOPR would not
add undue industry test burden, and
that the proposed test procedure for this
equipment is consistent with the
industry test procedure update. Further
discussion of the cost impacts of the
proposed test procedure are presented
in the following paragraphs.
As noted previously, currently DOE
does not prescribe test procedures for
DDX–DOASes, and AHRI 920–2020 is
the most recent version of the industry
test procedure applicable to DDX–
DOASes. DOE has tentatively
determined that the proposal to
incorporate by reference AHRI 920–
2020 is consistent with current industry
practice, and, therefore, manufacturers
would not be expected to incur any
additional costs if the proposal were
finalized. Importantly, the proposals in
this NOPR, if finalized, would not
require manufacturers to certify ratings
to DOE. DOE would address
certification as part of any rulemaking to
address energy conservation standards
for DDX–DOASes.
With that said, DOE is proposing to
define ‘‘dehumidifying direct
expansion-dedicated outdoor air
system’’ (DDX–DOAS) based on the
definition provided in AHRI 920–2020.
The differences in the proposed
definition as compared to the definition
in AHRI 920–2020 are to provide clarity
and use terminology consistent with
DOE’s test procedures for other
categories of commercial package air
conditioning and heating equipment.
DOE is proposing to limit the
applicability of the proposed test
procedure to DDX–DOASes with any
MRC less than 324 lbs. of moisture per
hour, whereas the scope of AHRI 920–
2020 is not limited based on MRC. In a
comment provided in response to the
July 2017 ASHRAE TP RFI, AHRI stated
that laboratory limitations may limit
testing using ANSI/AHRI 920–2015 to
300 lbs. of moisture per hour at
Standard Rating Condition A and to
units not physically larger than more
typical commercial package air
conditioning equipment with a capacity
of 760,000 Btu per hour. (AHRI, No. 11
at p. 20) As discussed in section III.A.3
of this document, DOE’s proposal to
limit the coverage of DDX–DOASes to
324 lbs. of moisture per hour in the
DDX–DOAS definition is a direct
conversion from the maximum cooling
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capacity limit of 760,000 Btu per hour
(which AHRI notes would be the upper
limit for laboratory capabilities), and it
is similar to the suggestion made by
AHRI. Hence the definitional
modifications to the industry standard
will not change the scope of coverage of
the proposed test procedure as
compared to the industry standard, and
if made final, would not result in any
increase in test burden as compared to
AHRI 920–2020.
AHRI 920–2020 does not explicitly
state the amount of external head
pressure to use when testing watercooled and water-source DDX–DOASes
with integral pumps. As noted, there are
a very limited number of DDX–DOAS
models with integral pumps on the
market. DOE is proposing to require
such units be tested with an external
head pressure equal to 20 ¥0/+1 feet of
water column, which is the same level
of external head pressure used in the
calculation of the pump effect for DDX–
DOASes without integral pumps. As
such, DOE considers this proposal to be
consistent with industry test procedure
because it ensures that integral pumps
are treated in the same way as nonintegral pumps, and as such would not
increase testing burden as compared to
current industry practice.
AHRI 920–2020 also does not
explicitly provide directions for setting
up the unit’s control settings at each
Standard Rating Condition. As
discussed in section III.B.3.g of this
document, DOE is proposing a general
requirement for all control settings to
remain unchanged for all Standard
Rating Conditions once system set up
has been completed, and that
component operation shall be controlled
by the unit under test once the
provisions for rating requirements are
met. This is likely how DDX–DOASes
would be tested as per the existing
instructions in AHRI 920–2020, but
DOE is providing the additional
specificity in order to ensure that the
results of the testing are representative,
repeatable, and reproducible, and as
such would not increase testing burden
as compared to current industry
practice.
AHRI 920–2020 incorrectly indicates
that Equation 20 should be used to
calculate the degradation coefficient for
DDX–DOASes with VERS (because
Equation 21 is indicated to apply for
DDX–DOASes with VERS). This is
discussed in further detail in section
III.B.3.l.ii of this document. DOE is
proposing to correct this statement to
instead use this equation for DDX–
DOASes without VERS, with
deactivated VERS, or with sensible-only
VERS tested under Standard Rating
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Conditions other than D. DOE considers
this proposal to be consistent with the
intent of the industry test procedure and
would not increase testing burden as
compared to AHRI 920–2020.
DOE’s proposal to provide a
definition for ‘‘non-standard low-static
fan motor’’ also serves to provide clarity
to the instructions present in AHRI 920–
2020 without affecting the scope of
coverage or testing burden. Absent this
definition, as discussed in section
III.B.3.l.iii of this document, it is not
possible to determine the appropriate
airflow setting procedure in section
6.1.5.2 of AHRI 920–2020.
AHRI 920–2020 does not provide
instruction for testing a DDX–DOAS for
which a manufacturer recommends
more than one refrigerant option. DOE
is proposing to require testing of such a
unit with each recommended refrigerant
if the different refrigerants require
different hardware. This proposal is
consistent with the treatment of basic
models of commercial packaged air
conditioners and heating equipment
under 10 CFR 430.92, and, as such, it
would be reflective of industry practice
for commercial packaged air conditioner
and heating equipment generally.
Therefore, this proposed addition to the
procedure laid out by AHRI 920–2020
would not increase testing burden as
compared current industry practice.
DOE is also proposing sampling
requirements for making representations
of ISMRE2 and ISCOP2, as applicable.
AHRI 920–2020 does not contain
comparable provisions. The sampling
requirements proposed are consistent
with the DOE sampling requirements
generally for commercial packaged air
conditioners and heating equipment,
and, if made final, would be reflective
of industry practice. Therefore, the
proposed sampling requirements, if
made final, would not increase testing
burden as compared to the current
industry practice.
Issue–14: DOE requests comment on
its understanding of the impact of the
test procedure proposals in this NOPR,
specifically DOE’s initial conclusion
that manufacturers would not incur any
additional costs due to this proposal, if
finalized, compared to current industry
practice, as indicated by AHRI 920–
2020.
4. Harmonization With Industry
Standards
DOE proposes to incorporate by
reference the provisions in AHRI 920–
2020, including definitions, test
methods, and rating requirements, with
certain modifications previously
discussed. Throughout this NOPR, DOE
discusses adopting this most recent
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relevant industry consensus testing
standard for DDX–DOAS equipment, as
required in 42 U.S.C. 6314 and
discussed in section III.B of this NOPR.
Issue–15: DOE seeks comment on the
degree to which the DOE test procedure
should consider and be harmonized
further with the most recent relevant
industry consensus testing standards for
DDX–DOASes and whether there could
be modifications to the industry test
method that would provide additional
benefits to the public. DOE also requests
comment on the benefits and burdens of
adopting any industry/voluntary
consensus-based or other appropriate
test procedure, without modification.
5. Other Test Procedure Topics
In addition to the issues identified
earlier in this document, DOE welcomes
comment on any other aspect of the
proposed test procedures for DDX–
DOASes not already addressed by the
specific areas identified in this
document. DOE particularly seeks
information that would ensure that the
test procedure measures energy
efficiency during a representative
average use cycle, as well as information
that would help DOE create a procedure
that is not unduly burdensome to
conduct.
E. Compliance Date
EPCA prescribes that, if DOE amends
a test procedure, all representations of
energy efficiency and energy use,
including those made in the context of
certification and on marketing materials
and product labels, must be made in
accordance with that amended test
procedure, beginning 360 days after
publication of such a test procedure
final rule in the Federal Register. (42
U.S.C. 6314(d)(1))
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IV. Procedural Issues and Regulatory
Review
A. Review Under Executive Order 12866
The Office of Management and Budget
(OMB) has determined that this test
procedure rulemaking does not
constitute a ‘‘significant regulatory
actions’’ under section 3(f) of Executive
Order 12866, ‘‘Regulatory Planning and
Review,’’ 58 FR 51735 (Oct. 4, 1993).
Accordingly, this action was not subject
to review under the Executive Order by
the Office of Information and Regulatory
Affairs (OIRA) in OMB.
B. Review Under the Regulatory
Flexibility Act
The Regulatory Flexibility Act (5
U.S.C. 601 et seq.) requires preparation
of an initial regulatory flexibility
analysis (‘‘IRFA’’) for any rule that by
law must be proposed for public
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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
has made its procedures and policies
available on the Office of the General
Counsel’s website at: energy.gov/gc/
office-general-counsel. DOE reviewed
this proposed rule under the provisions
of the Regulatory Flexibility Act and the
policies and procedures published on
February 19, 2003.
The following sections detail DOE’s
IRFA for this test procedure rulemaking.
1. Description of Reasons Why Action Is
Being Considered
DOE is undertaking this test
procedure rulemaking to establish a
DOE test procedure for DDX–DOASes in
response to updates to the relevant
industry consensus standard, American
Society of Heating, Refrigerating and
Air-Conditioning Engineers (ASHRAE)
Standard 90.1, Energy Standard for
Buildings Except Low-Rise Residential
Buildings, which, with its 2016
publication, both added efficiency
standards and specified a test procedure
for this equipment (i.e., AHRI 920–
2015). Subsequently, the AirConditioning, Heating, and Refrigeration
Institute (AHRI) updated its test
procedure with the publication of AHRI
920–2020. The Energy Policy and
Conservation Act (EPCA) 35 requires that
each time the test procedure referenced
by ASHRAE Standard 90.1 is updated,
DOE must update the Federal test
procedure consistent with the industry
update, unless there is clear and
convincing evidence that the update
would not be representative of an
average use cycle or would be unduly
burdensome to conduct.
2. Objectives of, and Legal Basis for,
Rule
EPCA, as amended, among other
things, authorizes DOE to regulate the
energy efficiency of a number of
consumer products and certain
industrial equipment. Title III, Part C 36
of EPCA, Public Law 94–163 (42 U.S.C.
6311–6317, as codified), added by
35 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).
36 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
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Public Law 95–619, Title IV, § 441(a),
established the Energy Conservation
Program for Certain Industrial
Equipment, which sets forth a variety of
provisions designed to improve energy
efficiency. This covered equipment
includes small, large, and very large
commercial package air conditioning
and heating equipment. (42 U.S.C.
6311(1)(B)–(D)) DOE has initially
determined that commercial package air
conditioning and heating equipment
includes DX–DOASes. As discussed in
section I.B of the NOPR document, DX–
DOASes had not previously been
addressed in DOE rulemakings and are
not currently subject to Federal test
procedures or energy conservation
standards.
Under EPCA, DOE’s energy
conservation program consists
essentially of four parts: (1) Testing, (2)
labeling, (3) Federal energy conservation
standards, and (4) certification and
enforcement procedures. Relevant
provisions of EPCA specifically include
definitions (42 U.S.C. 6311), energy
conservation standards (42 U.S.C. 6313),
test procedures (42 U.S.C. 6314),
labeling provisions (42 U.S.C. 6315),
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(b); 42 U.S.C. 6296), and (2)
making representations about the
efficiency of that equipment (42 U.S.C.
6314(d)). Similarly, DOE uses these test
procedures to determine whether the
equipment complies with relevant
standards promulgated under EPCA.
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 (b); 42 U.S.C. 6297) DOE
may, however, grant waivers of Federal
preemption in limited circumstances 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, the statute also
sets forth the criteria and procedures
DOE is required to follow when
prescribing or amending test procedures
for covered equipment. Specifically,
EPCA requires that any test procedure
prescribed or amended shall be
reasonably designed to produce test
results which measure energy
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efficiency, energy use, or estimated
annual operating cost of covered
equipment during a representative
average use cycle and requires that test
procedures not be unduly burdensome
to conduct. (42 U.S.C. 6314(a)(2))
EPCA requires that the test
procedures for commercial package air
conditioning and heating equipment be
those generally accepted industry
testing procedures or rating procedures
developed or recognized by the AirConditioning, Heating, and Refrigeration
Institute (AHRI) or by the American
Society of Heating, Refrigerating and
Air-Conditioning Engineers (ASHRAE),
as referenced in ASHRAE Standard
90.1, ‘‘Energy Standard for Buildings
Except Low-Rise Residential Buildings’’
(ASHRAE Standard 90.1). (42 U.S.C.
6314(a)(4)(A)) Further, if such an
industry test procedure is amended,
DOE must update its test procedure to
be consistent with the amended
industry test procedure, unless DOE
determines, by rule published in the
Federal Register and supported by clear
and convincing evidence, that such
amended test procedure would not meet
the requirements in 42 U.S.C. 6314(a)(2)
and (3), related to representative use
and test burden. (42 U.S.C.
6314(a)(4)(B))
EPCA also requires that, at least once
every seven years, DOE evaluate test
procedures for each type of covered
equipment, including commercial
package air conditioning and heating
equipment to determine whether
amended test procedures would more
accurately or fully comply with the
requirements for the test procedures not
to 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)–(3)) In
addition, if DOE determines that a test
procedure amendment is warranted, it
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
in the Federal Register its
determination not to amend the test
procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
A test procedure for a subset of DX–
DOASes (i.e., DDX–DOASes), was first
specified by ASHRAE Standard 90.1 in
the 2016 edition (ASHRAE Standard
90.1–2016). Pursuant to 42 U.S.C.
6314(a)(4)(B), and following updates to
the relevant test procedures which were
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referenced in ASHRAE Standard 90.1,
DOE is publishing this NOPR proposing
to establish a test procedure for DDX–
DOASes in satisfaction of its
aforementioned obligations under
EPCA.
3. Description and Estimate of Small
Entities Regulated
For manufacturers of small, large, and
very large air-conditioning and heating
equipment (including DDX–DOASes),
commercial warm-air furnaces, and
commercial water heaters, the Small
Business Administration (SBA) has set a
size threshold which defines those
entities classified as ‘‘small businesses’’
for the purposes of the statute. DOE
used the SBA’s small business size
standards to determine whether any
small entities would be subject to the
requirements of this rule. See 13 CFR
part 121. The equipment covered by this
rule are classified under North
American Industry Classification
System (‘‘NAICS’’) code 333415,37 ‘‘AirConditioning and Warm Air Heating
Equipment and Commercial and
Industrial Refrigeration Equipment
Manufacturing.’’ In 13 CFR 121.201, the
SBA sets a threshold of 1,250 employees
or fewer for an entity to be considered
as a small business for this category.
In reviewing the DDX–DOAS market,
DOE used company websites, marketing
research tools, product catalogues, and
other public information to identify
companies that manufacture DDX–
DOASes. DOE identified 16
manufacturers of DDX–DOASes affected
by this rulemaking. Out of these 16
manufacturers, DOE determined that
three are domestic small businesses.
DOE used subscription-based business
information tools to determine
headcount and revenue of the small
businesses.
Issue–16: DOE invites comment on
the number of domestic small
businesses producing DDX–DOASes for
the U.S. market.
4. Description and Estimate of
Compliance Requirements
EPCA requires DOE to adopt test
procedures for small, large, and very
large commercial package air
conditioning and heating equipment
consistent with the amended industry
test procedures developed or recognized
by AHRI as referenced in ASHRAE
Standard 90.1, unless the Secretary
determines that, supported by clear and
convincing evidence, to do so would not
meet the requirements for test
37 The size standards are listed by NAICS code
and industry description and are available at
www.sba.gov/document/support--table-sizestandards (Last accessed on April 20, 2021).
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procedures to be reasonably designed to
produce results that reflect energy
efficiency, energy use, and estimated
operating costs during a representative
average use cycle and not be unduly
burdensome to conduct. (42 U.S.C.
6314(a)(4)(B)) In this NOPR, DOE
proposes to establish a test procedure
for DDX–DOASes, which belong to a
category of small, large, and very large
commercial package air conditioning
and heating equipment. DOE is
proposing to establish a test procedure
that incorporates by reference the
applicable industry consensus test
methods (including the energy
efficiency descriptors) and that
establishes representation requirements.
Although AHRI 920–2020 is not yet
referenced as the applicable test
procedure in ASHRAE Standard 90.1, it
provides revised test methods that
update ANSI/AHRI 920–2015, which is
the referenced industry test standard.
For these reasons, DOE has tentatively
concluded that the methods in AHRI
920–2020 reflect the intention for
prevalent industry practice: It is likely
that manufacturers will use AHRI 920–
2020 in the future.
In its review of AHRI 920–2020, DOE
estimated the cost for third-party lab
testing of basic models to range from
$10,000 to $23,500 depending on
validation class, equipment capacity,
and equipment configuration. However,
manufactures are not required to
perform laboratory testing on all basic
models. DOE proposes to allow DDX–
DOAS manufacturers to use alternative
energy-efficiency determination
methods (AEDMs) for determining the
ISMRE2 and ISCOP2 (if applicable) in
accordance with 10 CFR 429.70. An
AEDM is a computer modeling or
mathematical tool that predicts the
performance of non-tested basic models.
These computer modeling and
mathematical tools, when properly
developed, can provide a relatively
straight-forward and reasonably
accurate means to predict the energy
usage or efficiency characteristics of a
basic model of a given covered product
or equipment and reduce the burden
and cost associated with testing.
DOE researched manufacturer DDX–
DOAS offerings and estimated the cost
to rate basic models according to the
proposed DOE test procedure (which is
not expected to have any additional cost
over AHRI 920–2020 38). Using
38 DOE has tentatively determined that the
proposed modifications to AHRI 920–2020 would
be unlikely to significantly increase burden, given
that DOE is referencing the prevailing industry test
procedure. So, presuming widespread usage of
AHRI 920–2020, its adoption as part of the Federal
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information collected on small business
equipment offerings and the upper
threshold of third-party testing costs,
DOE estimates an average expense of
approximately $200,000 per small
manufacturer. These testing expenses
would be less than 1% of revenue for
each small business. DOE tentatively
concludes that the estimate costs would
not present a significant burden to small
manufacturers.
The testing of DDX–DOASes would
not be required until such time as DOE
establishes DDX–DOAS energy
conservation standards and
manufacturers are required to comply
with those energy conservation
standards. As such, small manufacturers
will have a substantial timeframe to
prepare for the testing detailed in this
NOPR. Additionally, small
manufacturers already testing to AHRI
920–2020 would incur no additional
costs as a result of this proposed test
procedure.
Issue–17: DOE invites comment on
the testing costs and timing of testing
costs described in this IRFA.
5. Duplication, Overlap, and Conflict
With Other Rules and Regulations
DOE is not aware of any rules or
regulations that duplicate, overlap, or
conflict with the proposed rule being
considered in this action.
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6. Significant Alternatives to the Rule
DOE proposes to reduce burden on
manufacturers, including small
businesses, by allowing alternative
energy efficiency or energy use
determination methods (AEDMs) in lieu
of physical testing all basic models. An
AEDM is a computer modeling or
mathematical tool that predicts the
performance of non-tested basic models.
The use of computer modeling is more
time-efficient than physical testing.
Without AEDMs, the average cost to rate
all basic models would exceed $29
million per small manufacturer, as
compared to the $200,000 per small
manufacturer in the current proposal.
Additionally, DOE considered
alternative test methods and
modifications to the test procedure for
DDX–DOASes, and the Department has
tentatively determined that there are no
better alternatives than the
modifications and test procedures
proposed in this NOPR, in terms of both
meeting the agency’s objectives and
reducing burden. DOE examined
relevant industry test standards, and the
Department incorporated these
test procedure would be expected to result in little
additional cost, even with the minor modifications
proposed by DOE.
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standards in the proposed test
procedures whenever appropriate to
reduce test burden to manufacturers.
Specifically, this NOPR proposes that
DOE establish a test procedure for DDX–
DOASes through incorporation by
reference of AHRI 920–2020 with
modifications that are not expected to
increase test burden.
In addition, individual manufacturers
may petition for a waiver of the
applicable test procedure. (See 10 CFR
431.401.) Also, Section 504 of the
Department of Energy Organization Act,
42 U.S.C. 7194, provides authority for
the Secretary to adjust a rule issued
under EPCA in order to prevent ‘‘special
hardship, inequity, or unfair
distribution of burdens’’ that may be
imposed on that manufacturer as a
result of such rule. Manufacturers
should refer to 10 CFR part 1003 for
additional details.
C. Review Under the Paperwork
Reduction Act of 1995
Manufacturers of certain commercial
package air condition and heating
equipment 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/industrial equipment,
including commercial package air
condition and heating equipment. (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.
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.
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D. Review Under the National
Environmental Policy Act of 1969
DOE is analyzing this proposed
regulation in accordance with the
National Environmental Policy Act of
1969 (NEPA) and DOE’s NEPA
implementing regulations (10 CFR part
1021). DOE anticipates that this
rulemaking qualifies for categorical
exclusion A6 because it is a procedural
rulemaking and meets the requirements
for application of a categorical
exclusion. 10 CFR part 1021, subpart D,
Appendix A, section A6; See 10 CFR
1021.410. DOE will complete its NEPA
review before issuing the final rule.
E. Review Under Executive Order 13132
Executive Order 13132, ‘‘Federalism,’’
64 FR 43255 (August 4, 1999), imposes
certain requirements on Federal
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 has
examined this proposed rule and has
tentatively determined that it would 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 products that are the subject of this
proposed 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
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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
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, the proposed
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
proposed regulatory action likely to
result 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
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UMRA. 62 FR 12820; also available at
energy.gov/gc/office-general-counsel.
DOE examined this proposed 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
proposed rule would 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 proposed
regulation would 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). DOE has reviewed
this proposed 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
proposed significant energy action. A
‘‘significant energy action’’ is defined as
any action by an agency that
promulgated or is expected to lead to
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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 proposed significant energy action,
the agency must give a detailed
statement of any adverse effects on
energy supply, distribution, or use
should the proposal be implemented,
and of reasonable alternatives to the
action and their expected benefits on
energy supply, distribution, and use.
The proposed regulatory action to
adopt a test procedure for measuring the
energy efficiency of DDX–DOASes 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
proposed rule authorizes or requires use
of commercial standards, the notice of
proposed 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 proposed test procedure for
DDX–DOASes incorporate the following
applicable industry consensus
standards: AHRI 920–2020, ANSI/AHRI
1060–2018, ANSI/ASHRAE 37–2009,
ANSI/ASHRAE 41.1–2013, ANSI/
ASHRAE 41.6–2014, and ANSI/
ASHRAE 198–2013. DOE has evaluated
these standards and is unable to
conclude whether they fully comply
with the requirements of section 32(b) of
the FEAA (i.e., whether they were
developed in a manner that fully
provides for public participation,
comment, and review). DOE will
consult with both the Attorney General
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and the Chairman of the FTC
concerning the impact of these test
procedures on competition, prior to
prescribing a final rule.
M. Description of Materials
Incorporated by Reference
In this NOPR, DOE proposes to
incorporate by reference the following
test standards:
(1) The test standard published by
AHRI, titled ‘‘2020 Standard for
Performance Rating of DX-Dedicated
Outdoor Air System Units,’’ AHRI
Standard 920–2020 (I–P). AHRI
Standard 920–2020 (I–P) is an industryaccepted test procedure for measuring
the performance of DX-dedicated
outdoor air system units. AHRI
Standard 920–2020 (I–P) is available on
AHRI’s website at: www.ahrinet.org/
App_Content/ahri/files/STANDARDS/
AHRI/AHRI_Standard_920_I-P_
2020.pdf.
(2) The test standard published by
AHRI, titled ‘‘2018 Standard for
Performance Rating of Air-to-Air
Exchangers for Energy Recovery
Ventilation Equipment,’’ ANSI/AHRI
Standard 1060–2018. ANSI/AHRI
Standard 1060–2018 is an industryaccepted test procedure for measuring
the performance of air-to-air exchangers
for energy recovery ventilation
equipment. ANSI/AHRI Standard 1060–
2018 is available on AHRI’s website at:
www.ahrinet.org/App_Content/ahri/
files/STANDARDS/AHRI/AHRI_
Standard_1060_I-P_2018.pdf.
(3) The test standard test standard
published by ASHRAE, titled ‘‘Methods
of Testing for Rating Electrically Driven
Unitary Air-Conditioning and Heat
Pump Equipment,’’ ANSI/ASHRAE
Standard 37–2009. ANSI/ASHRAE
Standard 37–2009 is an industryaccepted test procedure for measuring
the performance of electrically driven
unitary air-conditioning and heat pump
equipment. ANSI/ASHRAE Standard
37–2009 is available on ASHRAE’s
website (in partnership with Techstreet)
at: www.techstreet.com/ashrae/
standards/ashrae-37-2009?product_
id=1650947.
(4) The test standard published by
ASHRAE, titled ‘‘Standard Method for
Temperature Measurement,’’ ANSI/
ASHRAE Standard 41.1–2013. ANSI/
AHRAE Standard 41.1–2013 is an
industry-accepted test procedure for
measuring temperature. ANSI/ASHRAE
Standard 41.1–2013 is available on
ASHRAE’s website (in partnership with
Techstreet) at: www.techstreet.com/
ashrae/standards/ashrae-41-12013?product_id=1853241.
(5) The test standard published by
ASHRAE, titled ‘‘Standard Method for
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Humidity Measurement,’’ ANSI/
ASHRAE Standard 41.6–2014. ANSI/
AHRAE Standard 41.6–2014 is an
industry-accepted test procedure for
measuring humidity. ANSI/ASHRAE
Standard 41.6–2014 is available on
ASHRAE’s website (in partnership with
Techstreet) at: www.techstreet.com/
ashrae/standards/ashrae-41-62014?product_id=1881840.
(6) The test standard published by
ASHRAE, titled ‘‘Method for Test for
Rating DX-Dedicated Outdoor Air
Systems for Moisture Removal Capacity
and Moisture Removal Efficiency,’’
ANSI/ASHRAE Standard 198–2013.
ANSI/ASHRAE Standard 198–2013 is
an industry-accepted test procedure for
measuring the performance of DXdedicated outdoor air system units.
ANSI/ASHRAE Standard 198–2013 is
available on ASHRAE’s website (in
partnership with Techstreet) at:
www.techstreet.com/ashrae/standards/
ashrae-198-2013?product_id=1852612.
V. Public Participation
A. Participation in the Webinar
The time and date of the webinar are
listed in the DATES section at the
beginning of this document. Webinar
registration information, participant
instructions, and information about the
capabilities available to webinar
participants will be published on DOE’s
website: www.energy.gov/eere/
buildings/public-meetings-andcomment-deadlines. Participants are
responsible for ensuring their systems
are compatible with the webinar
software. Additionally, you may request
an in-person meeting to be held prior to
the close of the request period provided
in the DATES section of this document.
Requests for an in-person meeting may
be made by contacting Appliance and
Equipment Standards Program staff at
(202) 287–1445 or by email: Appliance_
Standards_Public_Meetings@ee.doe.gov.
B. Procedure for Submitting Prepared
General Statements for Distribution
Any person who has an interest in the
topics addressed in this notice, or who
is representative of a group or class of
persons that has an interest in these
issues, may request an opportunity to
make an oral presentation at the
webinar/public meeting. Such persons
may submit requests to speak via email
to the Appliance and Equipment
Standards Program at:
ApplianceStandardsQuestions@
ee.doe.gov. Persons who wish to speak
should include with their request a
computer file in WordPerfect, Microsoft
Word, PDF, or text (ASCII) file format
that briefly describes the nature of their
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interest in this rulemaking and the
topics they wish to discuss. Such
persons should also provide a daytime
telephone number where they can be
reached.
Persons requesting to speak should
briefly describe the nature of their
interest in this rulemaking and provide
a telephone number for contact. DOE
requests persons selected to make an
oral presentation to submit an advance
copy of their statements at least two
weeks before the webinar/public
meeting. At its discretion, DOE may
permit persons who cannot supply an
advance copy of their statement to
participate, if those persons have made
advance alternative arrangements with
the Building Technologies Office. As
necessary, requests to give an oral
presentation should ask for such
alternative arrangements.
C. Conduct of the Webinar
DOE will designate a DOE official to
preside at the webinar meeting and may
also use a professional facilitator to aid
discussion. The meeting will not be a
judicial or evidentiary-type public
hearing, but DOE will conduct it in
accordance with section 336 of EPCA
(42 U.S.C. 6306). A court reporter will
be present to record the proceedings and
prepare a transcript. DOE reserves the
right to schedule the order of
presentations and to establish the
procedures governing the conduct of the
webinar/public meeting. There shall not
be discussion of proprietary
information, costs or prices, market
share, or other commercial matters
regulated by U.S. anti-trust laws. After
the webinar/public meeting and until
the end of the comment period,
interested parties may submit further
comments on the proceedings and any
aspect of the rulemaking.
The webinar/public meeting will be
conducted in an informal, conference
style. DOE will present summaries of
comments received before the webinar/
public meeting, allow time for prepared
general statements by participants, and
encourage all interested parties to share
their views on issues affecting this
rulemaking. Each participant will be
allowed to make a general statement
(within time limits determined by DOE),
before the discussion of specific topics.
DOE will permit, as time permits, other
participants to comment briefly on any
general statements.
At the end of all prepared statements
on a topic, DOE will permit participants
to clarify their statements briefly and
comment on statements made by others.
Participants should be prepared to
answer questions by DOE and by other
participants concerning these issues.
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DOE representatives may also ask
questions of participants concerning
other matters relevant to this
rulemaking. The official conducting the
webinar/public meeting will accept
additional comments or questions from
those attending, as time permits. The
presiding official will announce any
further procedural rules or modification
of the above procedures that may be
needed for the proper conduct of the
webinar/public meeting.
A transcript of the webinar/public
meeting will be included in the docket,
which can be viewed as described in the
Docket section at the beginning of this
NOPR. In addition, any person may buy
a copy of the transcript from the
transcribing reporter.
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D. Submission of Comments
DOE will accept comments, data, and
information regarding this proposed
rule no later than the date provided in
the DATES section at the beginning of
this proposed rule.39 Interested parties
may submit comments using any of the
methods described in the ADDRESSES
section at the beginning of this
document.
Submitting comments via
www.regulations.gov. The
www.regulations.gov web page will
require you to provide your name and
contact information. Your contact
information will be viewable to DOE
Building Technologies staff only. Your
contact information will not be publicly
viewable except for your first and last
names, organization name (if any), and
submitter representative name (if any).
If your comment is not processed
properly because of technical
difficulties, DOE will use this
information to contact you. If DOE
cannot read your comment due to
technical difficulties and cannot contact
39 DOE has historically provided a 75-day
comment period for test procedure NOPRs pursuant
to the North American Free Trade Agreement, U.S.Canada-Mexico (‘‘NAFTA’’), Dec. 17, 1992, 32
I.L.M. 289 (1993); the North American Free Trade
Agreement Implementation Act, Public Law 103–
182, 107 Stat. 2057 (1993) (codified as amended at
10 U.S.C.A. 2576) (1993) (‘‘NAFTA Implementation
Act’’); and Executive Order 12889, ‘‘Implementation
of the North American Free Trade Agreement,’’ 58
FR 69681 (Dec. 30, 1993). However, on July 1, 2020,
the Agreement between the United States of
America, the United Mexican States, and the United
Canadian States (‘‘USMCA’’), Nov. 30, 2018, 134
Stat. 11 (i.e., the successor to NAFTA), went into
effect, and Congress’s action in replacing NAFTA
through the USMCA Implementation Act, 19 U.S.C.
4501 et seq. (2020), implies the repeal of E.O. 12889
and its 75-day comment period requirement for
technical regulations. Thus, the controlling laws are
EPCA and the USMCA Implementation Act.
Consistent with EPCA’s public comment period
requirements for consumer products, the USMCA
only requires a minimum comment period of 60
days. Consequently, DOE now provides a 60-day
public comment period for test procedure NOPRs.
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you for clarification, DOE may not be
able to consider your comment.
However, your contact information
will be publicly viewable if you include
it in the comment or in any documents
attached to your comment. Any
information that you do not want to be
publicly viewable should not be
included in your comment, nor in any
document attached to your comment.
Persons viewing comments will see only
first and last names, organization
names, correspondence containing
comments, and any documents
submitted with the comments.
Do not submit to www.regulations.gov
information for which disclosure is
restricted by statute, such as trade
secrets and commercial or financial
information (hereinafter referred to as
Confidential Business Information
(CBI)). Comments submitted through
www.regulations.gov cannot be claimed
as CBI. Comments received through the
website will waive any CBI claims for
the information submitted. For
information on submitting CBI, see the
Confidential Business Information
section.
DOE processes submissions made
through www.regulations.gov before
posting. Normally, comments will be
posted within a few days of being
submitted. However, if large volumes of
comments are being processed
simultaneously, your comment may not
be viewable for up to several weeks.
Please keep the comment tracking
number that www.regulations.gov
provides after you have successfully
uploaded your comment.
Submitting comments via email.
Comments and documents submitted
via email also will be posted to
www.regulations.gov. If you do not want
your personal contact information to be
publicly viewable, do not include it in
your comment or any accompanying
documents. Instead, provide your
contact information in a cover letter.
Include your first and last names, email
address, telephone number, and
optional mailing address. The cover
letter will not be publicly viewable as
long as it does not include any
comments.
Include contact information each time
you submit comments, data, documents,
and other information to DOE. No
telefacsimiles (faxes) will be accepted.
Comments, data, and other
information submitted to DOE
electronically should be provided in
PDF (preferred), Microsoft Word or
Excel, WordPerfect, or text (ASCII) file
format. Provide documents that are not
secured, written in English, and free of
any defects or viruses. Documents
should not contain special characters or
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any form of encryption, and, if possible,
they should carry the electronic
signature of the author.
Campaign form letters. Please submit
campaign form letters by the originating
organization in batches of between 50 to
500 form letters per PDF or as one form
letter with a list of supporters’ names
compiled into one or more PDFs. This
reduces comment processing and
posting time.
Confidential Business Information.
Pursuant to 10 CFR 1004.11, any person
submitting information that he or she
believes to be confidential and exempt
by law from public disclosure should
submit via email two well-marked
copies: One copy of the document
marked ‘‘confidential’’ including all the
information believed to be confidential,
and one copy of the document marked
‘‘non-confidential’’ with the information
believed to be confidential deleted. DOE
will make its own determination about
the confidential status of the
information and treat it according to its
determination.
It is DOE’s policy that all comments
may be included in the public docket,
without change and as received,
including any personal information
provided in the comments (except
information deemed to be exempt from
public disclosure).
E. Issues on Which DOE Seeks Comment
Although DOE welcomes comments
on any aspect of this proposal, DOE is
particularly interested in receiving
comments and views of interested
parties concerning the following issues:
Issue–1: DOE requests comment on
the proposed definition for ‘‘direct
expansion-dedicated outdoor air
system.’’ DOE also requests comment on
any additional characteristics not yet
considered that could help to
distinguish DX–DOASes from other
commercial package air conditioning
and heating equipment.
Issue–2: DOE requests comment on
the proposed definition for
‘‘dehumidifying direct expansiondedicated outdoor air system.’’
Specifically, DOE requests comment on
the proposed criteria for distinguishing
a ‘‘dehumidifying direct expansiondedicated outdoor air system’’ from a
‘‘direct expansion-dedicated outdoor air
system’’ more generally. DOE also
requests comment on any additional
characteristics not yet considered that
could help to distinguish DDX–DOASes
from DX–DOASes more generally.
Issue–3: DOE seeks comment on its
translation of Btu per hour to MRC and
specifically its proposal to translate the
upper capacity limit for DDX–DOASes
such that a model would be considered
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in scope if it has an MRC less than 324
lbs. per hour.
Issue–4: DOE requests comment on its
proposal to clarify what terms are
synonymous with DDX–DOAS.
Issue–5: DOE requests comment and
data on the development of a crosswalk
from the efficiency levels in ASHRAE
Standard 90.1 based on ANSI/AHRI
920–2015 to efficiency levels based on
AHRI 920–2020. DOE is specifically
seeking data on how dehumidification
and heating efficiency ratings for a given
DDX–DOAS model are impacted when
measured using AHRI 920–2020 as
compared to ANSI/AHRI 920–2015.
Issue–6: DOE requests comment on
the terminology DOE proposes to use for
DDX–DOASes, including ‘‘integrated
seasonal coefficient of performance 2, or
ISCOP2;’’ ‘‘integrated seasonal moisture
removal efficiency 2, or ISMRE2;’’ and
‘‘ventilation energy recovery system, or
VERS.’’
Issue–7: DOE requests comment on
the proposal to require that watercooled and water-source DDX–DOASes
with integral pumps be set up with an
external pressure rise equal to 20 feet of
water column with a condition
tolerance of ¥0/+1 foot and an
operating tolerance of 1 foot.
Issue–8: DOE requests comment on
the proposed general control setting
requirement for DDX–DOASes.
Issue–9: DOE is requesting comment
on the proposed definition of ‘‘nonstandard low-static fan motor’’ and
whether the proposed definition reflects
stakeholder understanding of the term.
Issue–10: DOE seeks comment on the
proposed definition of basic model of a
DDX–DOAS.
Issue–11: DOE requests comment on
the sampling plan proposed for DDX–
DOASes. DOE specifically requests
information and data regarding the
proposed confidence level and whether
variability of testing of DDX–DOASes
would require a less stringent level, and
if so, what that level should be.
Issue–12: DOE requests comment on
its proposal regarding representations
for models approved for use with
multiple refrigerants.
Issue–13: DOE requests comment on
its proposals for AEDM requirements for
DDX–DOAS equipment. DOE requests
comment specifically on whether the
proposed 10-percent tolerance for
comparison of test results with rated
values is appropriate. If the 10-percent
tolerance is not appropriate, DOE
requests comment on why it is not
appropriate, as well as comment
indicating an appropriate tolerance.
Issue–14: DOE requests comment on
its proposal to adopt the rounding
requirements for key metrics as
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specified in sections 6.1.2.1 through
6.1.2.8 of AHRI 920–2020.
Issue–15: DOE requests comment on
its understanding of the impact of the
test procedure proposals in this NOPR,
specifically DOE’s initial conclusion
that manufacturers would not incur any
additional costs due to this proposal, if
finalized, compared to current industry
practice, as indicated by AHRI 920–
2020.
Issue–16: DOE seeks comment on the
degree to which the DOE test procedure
should consider and be harmonized
further with the most recent relevant
industry consensus testing standards for
DDX–DOASes and whether there could
be modifications to the industry test
method that would provide additional
benefits to the public. DOE also requests
comment on the benefits and burdens of
adopting any industry/voluntary
consensus-based or other appropriate
test procedure, without modification.
Issue–17: DOE invites comment on
the number of domestic small
businesses producing DDX–DOASes for
the U.S. market.
Issue–18: DOE invites comment on
the testing costs and timing of testing
costs described in this IRFA.
VI. Approval of the Office of the
Secretary
The Secretary of Energy has approved
publication of this proposed rule.
List of Subjects
10 CFR Part 429
Administrative practice and
procedure, Confidential business
information, Energy conservation,
Household appliances, Imports,
Incorporation by reference,
Intergovernmental relations, Reporting
and recordkeeping requirements, Small
businesses.
10 CFR Part 431
Administrative practice and
procedure, Confidential business
information, Energy conservation,
Incorporation by reference, Reporting
and recordkeeping requirements.
Signing Authority
This document of the Department of
Energy was signed on June 23, 2021, by
Kelly Speakes-Backman, Principal
Deputy Assistant Secretary and 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
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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.
Signed in Washington, DC, on June 23,
2021.
Treena V. Garrett,
Federal Register Liaison Officer, U.S.
Department of Energy.
For the reasons stated in the
preamble, DOE is proposing to amend
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
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 § 429.43 by adding
paragraph (a)(3) to read as follows:
■
§ 429.43 Commercial heating, ventilating,
air conditioning (HVAC) equipment.
(a) * * *
(3) Refrigerants: For dehumidifying
direct expansion-dedicated outdoor air
systems (DDX–DOASes), if a basic
model is distributed in commerce for
which the manufacturer specifies the
use of more than one refrigerant option,
the ISMRE2 and ISCOP2, as applicable,
are determined for that basic model
using the refrigerant that results in the
lowest ISMRE2 and the refrigerant that
results in the lowest ISCOP2, as
applicable. For example, the
dehumidification performance metric
ISMRE2 must be based on the
refrigerant yielding the lowest ISMRE2,
and the heating performance metric
ISCOP2 (if the unit is a heat pump
DDX–DOAS) must be based on the
refrigerant yielding the lowest ISCOP2.
A refrigerant is considered approved for
use if it is listed on the nameplate of the
single package unit or outdoor unit.
Pursuant to the definition of ‘‘basic
model’’ in § 431.92 of this chapter,
specification of an additional refrigerant
option that requires use of different
hardware (i.e., compressors, heat
exchangers, or air moving systems that
are not the same or comparably
performing), results in a different basic
model.
*
*
*
*
*
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3. Amend § 429.70 by revising the
tables in paragraphs (c)(2)(iv) and
(c)(5)(vi)(B) to read as follows:
■
§ 429.70 Alternative methods for
determining energy efficiency and energy
use.
*
*
*
*
*
(c) * * *
(2) * * *
(iv) * * *
Minimum number of
distinct models that
must be tested per
AEDM
Validation class
Air-Cooled, Split and Packaged Air Conditioners (ACs) and Heat Pumps (HPs) less than 65,000 Btu/h Cooling Capacity
(3-Phase).
2 Basic Models.
(A) Commercial HVAC Validation Classes
Air-Cooled, Split and Packaged ACs and HPs greater than or equal to 65,000 Btu/h Cooling Capacity and Less than
760,000 Btu/h Cooling Capacity.
Water-Cooled, Split and Packaged ACs and HPs, All Cooling Capacities ............................................................................
Evaporatively-Cooled, Split and Packaged ACs and HPs, All Capacities ..............................................................................
Water-Source HPs, All Capacities ...........................................................................................................................................
Single Package Vertical ACs and HPs ...................................................................................................................................
Packaged Terminal ACs and HPs ...........................................................................................................................................
Air-Cooled, Variable Refrigerant Flow ACs and HPs ..............................................................................................................
Water-Cooled, Variable Refrigerant Flow ACs and HPs ........................................................................................................
Computer Room Air Conditioners, Air Cooled ........................................................................................................................
Computer Room Air Conditioners, Water-Cooled ...................................................................................................................
Dehumidifying Direct Expansion-Dedicated Outdoor Air Systems, Air-cooled or Air-source Heat Pump, Without Ventilation Energy Recovery Systems.
Dehumidifying Direct Expansion-Dedicated Outdoor Air Systems, Air-cooled or Air-source Heat Pump, With Ventilation
Energy Recovery Systems.
Dehumidifying Direct Expansion-Dedicated Outdoor Air Systems, Water-cooled, Water-source Heat Pump, or Ground
Source Closed-loop Heat Pump, Without Ventilation Energy Recovery Systems.
Dehumidifying Direct Expansion-Dedicated Outdoor Air Systems, Water-cooled, Water-source Heat Pump, or Ground
Source Closed-loop Heat Pump, With Ventilation Energy Recovery Systems.
2 Basic Models.
2
2
2
2
2
2
2
2
2
2
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
2 Basic Models.
2 Basic Models.
2 Basic Models.
(B) Commercial Water Heater Validation Classes
Gas-fired Water Heaters and Hot Water Supply Boilers Less than 10 Gallons .....................................................................
Gas-fired Water Heaters and Hot Water Supply Boilers Greater than or Equal to 10 Gallons .............................................
Oil-fired Water Heaters and Hot Water Supply Boilers Less than 10 Gallons .......................................................................
Oil-fired Water Heaters and Hot Water Supply Boilers Greater than or Equal to 10 Gallons ...............................................
Electric Water Heaters .............................................................................................................................................................
Heat Pump Water Heaters ......................................................................................................................................................
Unfired Hot Water Storage Tanks ...........................................................................................................................................
2
2
2
2
2
2
2
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Models.
Models.
Models.
Models.
Models.
Models.
Models.
2
2
2
2
2
2
Basic
Basic
Basic
Basic
Basic
Basic
Models.
Models.
Models.
Models.
Models.
Models.
(C) Commercial Packaged Boilers Validation Classes
Gas-fired, Hot Water Only Commercial Packaged Boilers .....................................................................................................
Gas-fired, Steam Only Commercial Packaged Boilers ...........................................................................................................
Gas-fired Hot Water/Steam Commercial Packaged Boilers ...................................................................................................
Oil-fired, Hot Water Only Commercial Packaged Boilers .......................................................................................................
Oil-fired, Steam Only Commercial Packaged Boilers .............................................................................................................
Oil-fired Hot Water/Steam Commercial Packaged Boilers ......................................................................................................
(D) Commercial Furnace Validation Classes
Gas-fired Furnaces ..................................................................................................................................................................
Oil-fired Furnaces ....................................................................................................................................................................
2 Basic Models.
2 Basic Models.
khammond on DSKJM1Z7X2PROD with PROPOSALS3
(E) Commercial Refrigeration Equipment Validation Classes 1
Self-Contained Open Refrigerators .........................................................................................................................................
Self-Contained Open Freezers ................................................................................................................................................
Remote Condensing Open Refrigerators ................................................................................................................................
Remote Condensing Open Freezers .......................................................................................................................................
Self-Contained Closed Refrigerators .......................................................................................................................................
Self-Contained Closed Freezers .............................................................................................................................................
Remote Condensing Closed Refrigerators ..............................................................................................................................
Remote Condensing Closed Freezers ....................................................................................................................................
2
2
2
2
2
2
2
2
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Basic
Models.
Models.
Models.
Models.
Models.
Models.
Models.
Models.
1 The minimum number of tests indicated above must be comprised of a transparent model, a solid model, a vertical model, a semi-vertical
model, a horizontal model, and a service-over-the counter model, as applicable based on the equipment offering. However, manufacturers do not
need to include all types of these models if it will increase the minimum number of tests that need to be conducted.
*
*
*
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*
*
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(5) * * *
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(B) * * *
Metric
Commercial Packaged Boilers .....................................................................................
Combustion Efficiency ..............................
Thermal Efficiency ....................................
Thermal Efficiency ....................................
Standby Loss ............................................
R-Value .....................................................
Seasonal Energy-Efficiency Ratio ............
5% (0.05)
5% (0.05)
5% (0.05)
10% (0.1)
10% (0.1)
5% (0.05)
Heating Season Performance Factor .......
Energy Efficiency Ratio ............................
Energy Efficiency Ratio ............................
5% (0.05)
10% (0.1)
5% (0.05)
Coefficient of Performance .......................
Integrated Energy Efficiency Ratio ...........
Energy Efficiency Ratio ............................
Coefficient of Performance .......................
Integrated Energy Efficiency Ratio ...........
Energy Efficiency Ratio ............................
Coefficient of Performance .......................
Integrated Energy Efficiency Ratio ...........
Energy Efficiency Ratio ............................
Coefficient of Performance .......................
Integrated Energy Efficiency Ratio ...........
Energy Efficiency Ratio ............................
Coefficient of Performance .......................
Energy Efficiency Ratio ............................
Coefficient of Performance .......................
Energy Efficiency Ratio ............................
Coefficient of Performance .......................
Integrated Energy Efficiency Ratio ...........
Net Sensible Coefficient of Performance
Integrated Seasonal Coefficient of Performance 2.
Integrated Seasonal Moisture Removal
Efficiency 2.
Thermal Efficiency ....................................
Daily Energy Consumption .......................
5%
10% (0.1)
5% (0.05)
5% (0.05)
10% (0.1)
5% (0.05)
5% (0.05)
10% (0.1)
5% (0.05)
5% (0.05)
10% (0.1)
5% (0.05)
5% (0.05)
5% (0.05)
5% (0.05)
5% (0.05)
5% (0.05)
10% (0.1)
5% (0.05)
10% (0.1)
Commercial Water Heaters or Hot Water Supply Boilers ...........................................
Unfired Storage Tanks .................................................................................................
Air-Cooled, Split and Packaged ACs and HPs less than 65,000 Btu/h Cooling Capacity (3-Phase).
Air-Cooled, Split and Packaged ACs and HPs greater than or equal to 65,000 Btu/h
Cooling Capacity and Less than 760,000 Btu/h Cooling Capacity.
Water-Cooled, Split and Packaged ACs and HPs, All Cooling Capacities .................
Evaporatively-Cooled, Split and Packaged ACs and HPs, All Capacities ..................
Water-Source HPs, All Capacities ...............................................................................
Single Package Vertical ACs and HPs ........................................................................
Packaged Terminal ACs and HPs ...............................................................................
Variable Refrigerant Flow ACs and HPs .....................................................................
Computer Room Air Conditioners ................................................................................
Dehumidifying Direct Expansion-Dedicated Outdoor Air Systems ..............................
Commercial Warm-Air Furnaces ..................................................................................
Commercial Refrigeration Equipment ..........................................................................
*
*
*
*
*
PART 431—ENERGY EFFICIENCY
PROGRAM FOR CERTAIN
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
4. The authority citation for part 431
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317; 28 U.S.C.
2461 note.
5. Amend § 431.2 by revising the
definition of ‘‘Commercial HVAC & WH
product’’ to read as follows:
■
§ 431.2
Definitions.
*
khammond on DSKJM1Z7X2PROD with PROPOSALS3
Applicable
tolerance
Equipment
*
*
*
*
Commercial HVAC & WH product
means any small, large, or very large
commercial package air-conditioning
and heating equipment (as defined in
§ 431.92), packaged terminal air
conditioner (as defined in § 431.92),
packaged terminal heat pump (as
defined in § 431.92), single package
vertical air conditioner (as defined in
§ 431.92), single package vertical heat
pump (as defined in § 431.92), computer
room air conditioner (as defined in
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§ 431.92), variable refrigerant flow
multi-split air conditioner (as defined in
§ 431.92), variable refrigerant flow
multi-split heat pump (as defined in
§ 431.92), direct expansion-dedicated
outdoor air system (as defined in
§ 431.92), commercial packaged boiler
(as defined in § 431.82), hot water
supply boiler (as defined in § 431.102),
commercial warm air furnace (as
defined in § 431.72), instantaneous
water heater (as defined in § 431.102),
storage water heater (as defined in
§ 431.102), or unfired hot water storage
tank (as defined in § 431.102).
*
*
*
*
*
■ 6. Amend § 431.92 by:
■ a. Revising the definition of ‘‘Basic
model’’; and
■ b. Adding, in alphabetical order, the
definitions for ‘‘Dehumidifying direct
expansion-dedicated outdoor air system,
or DDX–DOAS,’’ ‘‘Direct expansiondedicated outdoor air system, or DX–
DOAS,’’ ‘‘Integrated seasonal coefficient
of performance 2, or ISCOP2,’’
‘‘Integrated seasonal moisture removal
efficiency 2, or ISMRE2,’’ and
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10% (0.1)
5% (0.05)
5% (0.05)
‘‘Ventilation energy recovery system, or
VERS’’.
The revision and additions read as
follows:
§ 431.92 Definitions concerning
commercial air conditioners and heat
pumps.
*
*
*
*
*
Basic model includes:
(1) Computer room air conditioners
means all units manufactured by one
manufacturer within a single equipment
class, having the same primary energy
source (e.g., electric or gas), and which
have the same or comparably
performing compressor(s), heat
exchangers, and air moving system(s)
that have a common ‘‘nominal’’ cooling
capacity.
(2) Dehumidifying direct expansiondedicated outdoor air system means all
units manufactured by one
manufacturer, having the same primary
energy source (e.g., electric or gas),
within a single equipment class; with
the same or comparably performing
compressor(s), heat exchangers,
ventilation energy recovery system(s) (if
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present), and air moving system(s) that
have a common ‘‘nominal’’ moisture
removal capacity.
(3) Packaged terminal air conditioner
(PTAC) or packaged terminal heat
pump (PTHP) means all units
manufactured by one manufacturer
within a single equipment class, having
the same primary energy source (e.g.,
electric or gas), and which have the
same or comparable compressors, same
or comparable heat exchangers, and
same or comparable air moving systems
that have a cooling capacity within 300
Btu/h of one another.
(4) Single package vertical units
means all units manufactured by one
manufacturer within a single equipment
class, having the same primary energy
source (e.g., electric or gas), and which
have the same or comparably
performing compressor(s), heat
exchangers, and air moving system(s)
that have a rated cooling capacity
within 1500 Btu/h of one another.
(5) Small, large, and very large aircooled or water-cooled commercial
package air conditioning and heating
equipment means all units
manufactured by one manufacturer
within a single equipment class, having
the same or comparably performing
compressor(s), heat exchangers, and air
moving system(s) that have a common
‘‘nominal’’ cooling capacity.
(6) Small, large, and very large water
source heat pump means all units
manufactured by one manufacturer
within a single equipment class, having
the same primary energy source (e.g.,
electric or gas), and which have the
same or comparable compressors, same
or comparable heat exchangers, and
same or comparable ‘‘nominal’’
capacity.
(7) Variable refrigerant flow systems
means all units manufactured by one
manufacturer within a single equipment
class, having the same primary energy
source (e.g., electric or gas), and which
have the same or comparably
performing compressor(s) that have a
common ‘‘nominal’’ cooling capacity
and the same heat rejection medium
(e.g., air or water) (includes VRF water
source heat pumps).
*
*
*
*
*
Dehumidifying direct expansiondedicated outdoor air system, or DDX–
DOAS, means a direct expansiondedicated outdoor air system that is
capable of dehumidifying air to a 55 °F
dew point—when operating under
Standard Rating Condition A as
specified in Table 4 or Table 5 of AHRI
920–2020 (incorporated by reference,
see § 431.95) with a barometric pressure
of 29.92 in Hg—for any part of the range
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of airflow rates advertised in
manufacturer materials, and has a
moisture removal capacity of less than
324 lb/h.
Direct expansion-dedicated outdoor
air system, or DX–DOAS, means a
category of small, large, or very large
commercial package air-conditioning
and heating equipment which is capable
of providing ventilation and
conditioning of 100-percent outdoor air
or marketed in materials (including but
not limited to, specification sheets,
insert sheets, and online materials) as
having such capability.
*
*
*
*
*
Integrated seasonal coefficient of
performance 2, or ISCOP2, means a
seasonal weighted-average heating
efficiency for heat pump dedicated
outdoor air systems, expressed in W/W,
as measured according to appendix B of
this subpart.
Integrated seasonal moisture removal
efficiency 2, or ISMRE2, means a
seasonal weighted average
dehumidification efficiency for
dedicated outdoor air systems,
expressed in lbs. of moisture/kWh, as
measured according to appendix B of
this subpart.
*
*
*
*
*
Ventilation energy recovery system, or
VERS, means a system that preconditions outdoor ventilation air
entering the equipment through direct
or indirect thermal and/or moisture
exchange with the exhaust air, which is
defined as the building air being
exhausted to the outside from the
equipment.
*
*
*
*
*
■ 7. Section 431.95 is amended by:
■ a. Revising paragraph (a) and the
introductory text to paragraph (b);
■ b. Redesignating paragraphs (b)(6) and
(7) as (b)(8) and (9);
■ c. Adding new paragraphs (b)(6) and
(7);
■ d. Revising the introductory text to
paragraph (c) and paragraph (c)(2);
■ e. Redesignating paragraphs (c)(3) and
(4) as (c)(5) and (6); and
■ f. Adding new paragraphs (c)(3) and
(4), and paragraph (c)(7).
The revisions and additions read as
follows:
§ 431.95 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, DOE must publish a
document in the Federal Register and
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36057
the material must be available to the
public. All approved material is
available for inspection at the U.S.
Department of Energy, Office of Energy
Efficiency and Renewable Energy,
Building Technologies Program, 6th
Floor, 950 L’Enfant Plaza SW,
Washington, DC 20024, (202) 586–1445,
or go to: www.energy.gov/eere/
buildings/appliance-and-equipmentstandards-program, and may be
obtained from the other sources in this
section. It is also available for
inspection at the National Archives and
Records Administration (NARA). For
information on the availability of this
material at NARA, email: fedreg.legal@
nara.gov, or go to: www.archives.gov/
federal-register/cfr/ibr-locations.html.
(b) AHRI. Air-Conditioning, Heating,
and Refrigeration Institute, 2311 Wilson
Blvd., Suite 400, Arlington, VA 22201,
(703) 524–8800, or go to:
www.ahrinet.org.
*
*
*
*
*
(6) AHRI Standard 920–2020 (I–P),
(‘‘AHRI 920–2020’’), ‘‘2020 Standard for
Performance Rating of DX-Dedicated
Outdoor Air System Units,’’ approved
February 4, 2020, IBR approved for
appendix B to this subpart.
(7) AHRI Standard 1060–2018,
(‘‘ANSI/AHRI 1060–2018’’), ‘‘2018
Standard for Performance Rating of Airto-Air Exchangers for Energy Recovery
Ventilation Equipment,’’ approved
2018, (ANSI/AHRI 1060–2018), IBR
approved for appendix B to this subpart.
(c) ASHRAE. American Society of
Heating, Refrigerating and AirConditioning Engineers, 180
Technology Parkway, Peachtree
Corners, Georgia 30092, (404) 636–8400,
or go to: www.ashrae.org.
*
*
*
*
*
(2) ANSI/ASHRAE Standard 37–2009,
(‘‘ANSI/ASHRAE 37’’ or ‘‘ANSI/
ASHRAE 37–2009’’), ‘‘Methods of
Testing for Rating Electrically Driven
Unitary Air-Conditioning and Heat
Pump Equipment,’’ ASHRAE approved
June 24, 2009, IBR approved for § 431.96
and appendices A and B to this subpart.
(3) ANSI/ASHRAE Standard 41.1–
2013, (‘‘ANSI/ASHRAE 41.1–2013’’),
‘‘Standard Method for Temperature
Measurement,’’ ANSI approved January
30, 2013, IBR approved for appendix B
to this subpart.
(4) ANSI/ASHRAE Standard 41.6–
2014, (‘‘ANSI/ASHRAE 41.6–2014’’),
‘‘Standard Method for Humidity
Measurement,’’ ANSI approved July 3,
2014, IBR approved for appendix B to
this subpart.
*
*
*
*
*
(7) ANSI/ASHRAE Standard 198–
2013, (‘‘ANSI/ASHRAE 198–2013’’),
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‘‘Method of Test for Rating DXDedicated Outdoor Air Systems for
Moisture Removal Capacity and
Moisture Removal Efficiency,’’
approved by ANSI on January 30, 2013,
IBR approved for appendix B to this
subpart.
*
*
*
*
*
■ 8. Amend § 431.96 by:
■ a. Revising paragraph (a) and Table 1
in paragraph (b)(2); and
b. Designating the table in paragraph
(d) as Table 2 to paragraph (d).
The revisions read as follows:
■
§ 431.96 Uniform test method for the
measurement of energy efficiency of
commercial air conditioners and heat
pumps.
(a) Scope. This section contains test
procedures for measuring, pursuant to
EPCA, the energy efficiency of any
small, large, or very large commercial
package air-conditioning and heating
equipment, packaged terminal air
conditioners and packaged terminal
heat pumps, computer room air
conditioners, variable refrigerant flow
systems, single package vertical air
conditioners and single package vertical
heat pumps, and dehumidifying direct
expansion-dedicated outdoor air
systems.
(b) * * *
(2) * * *
TABLE 1 TO PARAGRAPH (b)—TEST PROCEDURES FOR COMMERCIAL AIR CONDITIONERS AND HEAT PUMPS
Energy efficiency
descriptor
Air-Cooled, 3-Phase,
AC and HP.
<65,000 Btu/h ...........
SEER and HSPF ......
AHRI 210/240–2008
(omit section 6.5).
Paragraphs (c) and
(e).
Air-Cooled AC and
HP.
Water-Cooled and
EvaporativelyCooled AC.
≥65,000 Btu/h and
<135,000 Btu/h.
<65,000 Btu/h ...........
EER, IEER, and COP
Appendix A to this
subpart.
AHRI 210/240–2008
(omit section 6.5).
None.
EER ...........................
Water-Source HP ......
≥65,000 Btu/h and
<135,000 Btu/h.
<135,000 Btu/h .........
Air-Cooled AC and
HP.
≥135,000 Btu/h and
<240,000 Btu/h.
EER, IEER and COP
Water-Cooled and
EvaporativelyCooled AC.
Air-Cooled AC and
HP.
≥135,000 Btu/h and
<240,000 Btu/h.
Equipment type
Small Commercial
Package Air-Conditioning and Heating
Equipment.
Large Commercial
Package Air-Conditioning and Heating
Equipment.
Very Large Commercial Package AirConditioning and
Heating Equipment.
Packaged Terminal Air
Conditioners and
Heat Pumps.
Computer Room Air
Conditioners.
Variable Refrigerant
Flow Multi-split Systems.
khammond on DSKJM1Z7X2PROD with PROPOSALS3
Variable Refrigerant
Flow Multi-split Systems, Air-cooled.
Variable Refrigerant
Flow Multi-split Systems, Water-source.
Single Package
Vertical Air Conditioners and Single
Package Vertical
Heat Pumps.
VerDate Sep<11>2014
Additional test
procedure provisions
as indicated in the
listed paragraphs of
this section
Cooling capacity or
moisture removal
capacity
Category
EER ...........................
Use tests, conditions,
and procedures 1 in
Paragraphs (c) and
(e).
AHRI 340/360–2007
(omit section 6.3).
ISO Standard 13256–
1 (1998).
Appendix A to this
subpart.
Paragraphs (c) and
(e).
Paragraph (e).
EER ...........................
AHRI 340/360–2007
(omit section 6.3).
Paragraphs (c) and
(e).
≥240,000 Btu/h and
<760,000 Btu/h.
EER, IEER and COP
Appendix A to this
subpart.
None.
Water-Cooled and
EvaporativelyCooled AC.
AC and HP ................
≥240,000 Btu/h and
<760,000 Btu/h.
EER ...........................
AHRI 340/360–2007
(omit section 6.3).
Paragraphs (c) and
(e).
<760,000 Btu/h .........
EER and COP ..........
Paragraph (g) of this
section.
Paragraphs (c), (e),
and (g).
AC .............................
<65,000 Btu/h ...........
SCOP ........................
≥65,000 Btu/h and
<760,000 Btu/h.
<65,000 Btu/h (3phase).
SCOP ........................
Paragraphs (c) and
(e).
Paragraphs (c) and
(e).
Paragraphs (c), (d),
(e), and (f).
≥65,000 Btu/h and
<760,000 Btu/h.
EER ...........................
<65,000 Btu/h (3phase).
SEER and HSPF ......
≥65,000 Btu/h and
<760,000 Btu/h.
EER and COP ..........
HP .............................
<760,000 Btu/h .........
EER and COP ..........
AC and HP ................
<760,000 Btu/h .........
EER and COP ..........
ASHRAE 127–2007
(omit section 5.11).
ASHRAE 127–2007
(omit section 5.11).
AHRI 1230–2010
(omit sections 5.1.2
and 6.6).
AHRI 1230–2010
(omit sections 5.1.2
and 6.6).
AHRI 1230–2010
(omit sections 5.1.2
and 6.6).
AHRI 1230–2010
(omit sections 5.1.2
and 6.6).
AHRI 1230–2010
(omit sections 5.1.2
and 6.6).
AHRI 390–2003 (omit
section 6.4).
AC .............................
HP .............................
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EER and COP ..........
SEER ........................
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None.
Paragraphs (c), (d),
(e), and (f).
Paragraphs (c), (d),
(e), and (f).
Paragraphs (c), (d),
(e), and (f).
Paragraphs (c), (d),
(e), and (f).
Paragraphs (c) and
(e).
36059
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TABLE 1 TO PARAGRAPH (b)—TEST PROCEDURES FOR COMMERCIAL AIR CONDITIONERS AND HEAT PUMPS—Continued
Equipment type
Dehumidifying Direct
Expansion-Dedicated Outdoor Air
Systems.
Cooling capacity or
moisture removal
capacity
Energy efficiency
descriptor
<324 lbs. of moisture
removal/hr.
ISMRE2 and ISCOP2
Category
All ..............................
Use tests, conditions,
and procedures 1 in
Appendix B of this
subpart.
Additional test
procedure provisions
as indicated in the
listed paragraphs of
this section
None.
1 Incorporated
2 Moisture
by reference; see § 431.95.
removal capacity is determined according to appendix B of this subpart.
*
*
*
*
*
9. Add Appendix B to subpart F of
part 431 to read as follows:
■
khammond on DSKJM1Z7X2PROD with PROPOSALS3
Appendix B to Subpart F of Part 431—
Uniform Test Method for Measuring the
Energy Consumption of Dehumidifying
Direct Expansion-Dedicated Outdoor
Air Systems
Note: Beginning [date 360 days after
publication of a test procedure final rule],
representations with respect to energy use or
efficiency of dehumidifying direct
expansion-dedicated outdoor air systems
must be based on testing conducted in
accordance with this appendix.
Manufacturers may elect to use this appendix
early.
1. Referenced materials.
1.1. Incorporation by reference.
DOE incorporated by reference in § 431.95,
the entire standard for AHRI 920–2020,
ANSI/AHRI 1060–2018; ANSI/ASHRAE 37–
2009, ANSI/ASHRAE 41.1–2013, ANSI/
ASHRAE 41.6–2014, and ANSI/ASHRAE
198–2013. However, only enumerated
provisions of AHRI 920–2020, ANSI/
ASHRAE 37–2009, ANSI/ASHRAE 41.6–
2014, and ANSI/ASHRAE 198–2013, as set
forth in paragraphs (a) through (d) of this
section are applicable. To the extent there is
a conflict between the terms or provisions of
a referenced industry standard and the CFR,
the CFR provisions control.
(a) AHRI 920–2020:
(i) Section 3—Definitions, as specified in
section 2.2.1(a) of this appendix;
(ii) Section 5—Test Requirements, as
specified in section 2.2.1(b) of this appendix;
(iii) Section 6—Rating Requirements, as
specified in section 2.2.1(c) of this appendix,
omitting section 6.1.2 (but retaining sections
6.1.2.1–6.1.2.8) and 6.6.1;
(iv) Section 11—Symbols and Subscripts,
as specified in section 2.2.1(d) of this
appendix;
(v) Appendix A—References—Normative,
as specified in section 2.2.1(e) of this
appendix;
(vi) Appendix C—ANSI/ASHRAE Standard
198 and ANSI/ASHRAE Standard 37
Additions, Clarifications and Exceptions—
Normative, as specified in section 2.2.1(f) of
this appendix, and
(vii) Appendix F—Unit Configuration for
Standard Efficiency Determination—
Normative, as specified in section 2.2.1(g) of
this appendix.
(b) ANSI/ASHRAE 37–2009:
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Jkt 253001
(i) Section 5.1—Temperature Measuring
Instruments (excluding sections 5.1.1 and
5.1.2), as specified in sections 2.2.1(b) and (f)
of this appendix;
(ii) Section 5.2—Refrigerant, Liquid, and
Barometric Pressure Measuring Instruments,
as specified in section 2.2.1(b) of this
appendix;
(iii) Sections 5.3—Air Differential Pressure
and Airflow Measurements, as specified in
section 2.2.1(b) of this appendix;
(iv) Sections 5.5(b)—Volatile Refrigerant
Measurement, as specified in section 2.2.1(b)
of this appendix;
(v) Section 6.1—Enthalpy Apparatus
(excluding 6.1.1 and 6.1.3 through 6.1.6), as
specified in section 2.2.1(b) of this appendix;
(vi) Section 6.2—Nozzle Airflow
Measuring Apparatus, as specified in section
2.2.1(b) of this appendix;
(vii) Section 6.3—Nozzles, as specified in
section 2.2.1(b) of this appendix;
(viii) Section 6.4—External Static Pressure
Measurements, as specified in section
2.2.1(b) of this appendix;
(ix) Section 6.5—Recommended Practices
for Static Pressure Measurements, as
specified in section 2.2.1(f) of this appendix;
(x) Section 7.3—Indoor and Outdoor Air
Enthalpy Methods, as specified in section
2.2.1(f) of this appendix;
(xi) Section 7.4—Compressor Calibration
Method, as specified in section 2.2.1(f) of this
appendix;
(xii) Section 7.5—Refrigerant Enthalpy
Method, as specified in section 2.2.1(f) of this
appendix;
(xiii) Section 7.6—Outdoor Liquid Coil
Method, as specified in section 2.2.1(f) of this
appendix;
(xiv) Section 7.7—Airflow Rate
Measurement (excluding sections 7.7.1.2,
7.7.3, and 7.7.4), as specified in section
2.2.1(b) of this appendix;
(xv) Table 1—Applicable Test Methods, as
specified in section 2.2.1(f) of this appendix;
(xvi) Section 8.6—Additional
Requirements for the Outdoor Air Enthalpy
Method, as specified in section 2.2.1(f) of this
appendix;
(xvii) Table 2b—Test Tolerances (I–P
Units), as specified in sections 2.2.1(c) and
2.2(f) of this appendix; and
(xviii) Errata sheet issued on October 3,
2016, as specified in section 2.2.1(f) of this
appendix.
(c) ANSI/ASHRAE 41.6–2014:
(i) Section 4—Classifications, as specified
in section 2.2.1(f) of this appendix;
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(ii) Section 5—Requirements, as specified
in section 2.2.1(f) of this appendix;
(iii) Section 6—Instruments and
Calibration, as specified in section 2.2.1(f) of
this appendix;
(iv) Section 7.1—Standard Method Using
the Cooled-Surface Condensation Hygrometer
as specified in section 2.2.1(f) of this
appendix; and
(v) Section 7.4—Electronic and Other
Humidity Instruments. as specified in section
2.2.1(f) of this appendix.
(d) ANSI/ASHRAE 198–2013:
(i) Section 4.4—Temperature Measuring
Instrument, as specified in section 2.2.1(b) of
this appendix;
(ii) Section 4.5—Electrical Instruments, as
specified in section 2.2.1(b) of this appendix;
(iii) Section 4.6—Liquid Flow
Measurement, as specified in section 2.2.1(b)
of this appendix;
(iv) Section 4.7—Time and Mass
Measurements, as specified in section
2.2.1(b) of this appendix;
(v) Section 6.1—Test Room Requirements,
as specified in section 2.2.1(b) of this
appendix;
(vi) Section 6.6—Unit Preparation, as
specified in section 2.2.1(b) of this appendix;
(vii) Section 7.1—Preparation of the Test
Room(s), as specified in section 2.2.1(b) of
this appendix;
(viii) Section 7.2—Equipment Installation,
as specified in section 2.2.1(b) of this
appendix;
(ix) Section 8.2—Equilibrium, as specified
in section 2.2.1(b) of this appendix, and
(x) Section 8.4—Test Duration and
Measurement Frequency, as specified in
section 2.2.1(b) of this appendix.
1.2. Informational materials.
DOE refers to the following provision of
AHRI 920–2020, for informational purposes
only:
(a) Appendix E—Typical Test Unit
Installations—Informative, as specified in
section 2.2.1(g) of this appendix.
(b) Reserved.
2. Test Method.
2.1. Capacity.
Moisture removal capacity (in pounds per
hour) and supply airflow rate (in standard
cubic feet per minute) are determined
according to AHRI 920–2020 (incorporated
by reference; see § 431.95) as specified in
section 2.2 of this appendix.
2.2. Efficiency.
2.2.1. Determine the ISMRE2 for all DDX–
DOASes and the ISCOP2 for all heat pump
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DDX–DOASes in accordance with the
following sections of AHRI 920–2020.
(a) Section 3—Definitions, including the
references to ANSI/AHRI 1060–2018
(incorporated by reference; see § 431.95);
(i) Non-standard Low-static Fan Motor. A
supply fan motor that cannot maintain
external static pressure as high as specified
in Table 7 of AHRI 920–2020 when operating
at a manufacturer-specified airflow rate and
that is distributed in commerce as part of an
individual model within the same basic
model of a DDX–DOAS that is distributed in
commerce with a different motor specified
for testing that can maintain the required
external static pressure.
(b) Section 5—Test Requirements,
including the references to sections 5.1, 5.2,
5.3, 5.5, 6.1, 6.2, 6.3, 6.4, and 7.7 (not
including sections 7.7.1.2, 7.7.3, and 7.7.4) of
ANSI/ASHRAE 37–2009 (incorporated by
reference; see § 431.95), and sections 4.4, 4.5,
4.6, 4.7, 5.1, 6.1, 6.6, 7.1, 7.2, 8.2, and 8.4 of
ANSI/ASHRAE 198–2013 (incorporated by
reference; see § 431.95);
(i) All control settings are to remain
unchanged for all Standard Rating
Conditions once system set up has been
completed, except as explicitly allowed or
required by AHRI 920–2020 or as indicated
in the supplementary test instructions (STI).
Component operation shall be controlled by
the unit under test once the provisions in
section 2.2.1(c) of this appendix are met.
(c) Section 6—Rating Requirements
(omitting sections 6.1.2 and 6.6.1), including
the references to Table 2b of ANSI/ASHRAE
37–2009, and ANSI/ASHRAE 198–2013.
(i) For water-cooled DDX–DOASes, the
‘‘Condenser Water Entering Temperature,
Cooling Tower Water’’ conditions specified
in Table 4 of AHRI 920–2020 shall be used.
For water-source heat pump DDX–DOASes,
the ‘‘Water-Source Heat Pumps’’ conditions
VerDate Sep<11>2014
18:50 Jul 06, 2021
Jkt 253001
specified in Table 5 of AHRI 920–2020 shall
be used.
(ii) For water-cooled or water-source DDX–
DOASes with integral pumps, set the external
head pressure to 20 ft. of water column, with
a ¥0/+1 ft. condition tolerance and a 1 ft.
operating tolerance.
(iii) When using the degradation coefficient
method as specified in section 6.9.2 of AHRI
920–2020, Equation 20 applies to DDX–
DOAS without VERS, with deactivated VERS
(see section 5.4.3 of AHRI 920–2020), or
sensible-only VERS tested under Standard
Rating Conditions other than D.
(iv) Rounding requirements for
representations are to be followed as stated
in sections 6.1.2.1 through 6.1.2.8 of AHRI
920–2020;
(d) Section 11—Symbols and Subscripts,
including references to ANSI/ASHRAE 1060–
2018;
(e) Appendix A—References—Normative;
(f) Appendix C—ANSI/ASHRAE 198–2013
and ANSI/ASHRAE 37 Additions,
Clarifications and Exceptions—Normative,
including references to sections 5.1, 6.5, 7.3,
7.4, 7.5, 7.6, 8.6, Table 1, Table 2b, and the
errata sheet of ANSI/ASHRAE 37–2009,
ANSI/ASHRAE 41.1–2013 (incorporated by
reference; see § 431.95), sections 4, 5, 6, 7.1,
and 7.4 of ANSI/ASHRAE 41.6–2014
(incorporated by reference; see § 431.95), and
ANSI/ASHRAE 1060–2018;
(g) Appendix E—Typical Test Unit
Installations—Informative, for information
only;
(h) Appendix F—Unit Configuration for
Standard Efficiency Determination—
Normative.
2.2.2. Optional Representations. Test
provisions for the determination of the
metrics indicated in paragraphs (a) through
(d) of this section are optional and are
determined according to the applicable
provisions in section 2.2.1 of this appendix.
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For water-cooled DDX–DOASes, these
optional representations may be determined
using either the ‘‘Condenser Water Entering
Temperature, Cooling Tower’’ or the
‘‘Condenser Water Entering Temperature,
Chilled Water’’ conditions specified in Table
4 of AHRI 920–2020. For water-source heat
pump DDX–DOASes, these optional
representations may be determined using
either the ‘‘Water-Source Heat Pumps’’ or
‘‘Water-Source Heat Pump, Ground-Source
Closed Loop’’ conditions specified in Table
5 of AHRI 920–2020. The following metrics
in AHRI 920–2020 are optional:
(a) ISMRE70;
(b) COPFull,x:
(c) COPDOAS,x: and
(d) ISMRE2 and ISCOP2 for water-cooled
DDX–DOASes using the ‘‘Condenser Water
Entering Temperature, Chilled Water’’
conditions specified in Table 4 of AHRI 920–
2020 and for water-source heat pump DDX–
DOASes using the ‘‘Water-Source Heat
Pump, Ground-Source Closed Loop’’
conditions specified in Table 5 of AHRI 920–
2020.
2.3. Synonymous terms.
(a) Any references to Dedicated Outdoor
Air System Unit (DOAS Unit), Dedicated
Outdoor Air System (DOAS), and Direct
Expansion Dedicated Outdoor Air System
(DX–DOAS) in AHRI 920–2020 and ANSI/
ASHRAE 198–2013 shall be considered
synonymous with Dehumidifying Direct
Expansion-Dedicated Outdoor Air System
(DDX–DOAS) as defined in § 431.92.
(b) Any references to energy recovery or
energy recovery ventilator (ERV) in AHRI
920–2020 and ANSI/ASHRAE 198–2013
shall be considered synonymous with
ventilation energy recovery system (VERS) as
defined in § 431.92.
[FR Doc. 2021–13773 Filed 7–6–21; 8:45 am]
BILLING CODE 6450–01–P
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Agencies
[Federal Register Volume 86, Number 127 (Wednesday, July 7, 2021)]
[Proposed Rules]
[Pages 36018-36060]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-13773]
[[Page 36017]]
Vol. 86
Wednesday,
No. 127
July 7, 2021
Part III
Department of Energy
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10 CFR Parts 429 and 431
Energy Conservation Program: Test Procedure for Dehumidifying Direct
Expansion-Dedicated Outdoor Air Systems; Proposed Rule
Federal Register / Vol. 86 , No. 127 / Wednesday, July 7, 2021 /
Proposed Rules
[[Page 36018]]
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DEPARTMENT OF ENERGY
10 CFR Parts 429 and 431
[EERE-2017-BT-TP-0018]
RIN 1904-AD93
Energy Conservation Program: Test Procedure for Dehumidifying
Direct Expansion-Dedicated Outdoor Air Systems
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking and request for comment.
-----------------------------------------------------------------------
SUMMARY: The U.S. Department of Energy (DOE) is proposing to establish
definitions for ``direct expansion-dedicated outdoor air systems'' (DX-
DOAS or DX-DOASes) and ``dehumidifying direct expansion-dedicated
outdoor air systems'' (DDX-DOAS or DDX-DOASes). DX-DOASes are a
category of small, large, and very large commercial package air
conditioning and heating equipment under the Energy Policy and
Conservation Act (EPCA), as amended. In addition, DOE is proposing to
establish a test procedure to measure the energy efficiency of DDX-
DOASes, which aligns with the most recent version of the relevant
industry consensus test standards for DDX-DOASes, with certain minor
modifications. Lastly, DOE is proposing to add supporting definitions,
energy efficiency metrics for dehumidification and heating modes, and
provisions governing public representations as part of this rulemaking.
DOE welcomes written comment from the public on any subject within the
scope of this document (including topics not specifically raised in
this proposal), as well as the submission of data and other relevant
information.
DATES: Comments: DOE will accept written comments, data, and
information regarding this notice of proposed rulemaking (NOPR) on or
before September 7, 2021. See section V, ``Public Participation,'' for
details.
Meeting: DOE will hold a webinar on Monday, August 2, 2021 from
10:00 a.m. to 4:00 p.m. See section V, ``Public Participation,'' for
webinar registration information, participant instructions, and
information about the capabilities available to webinar participants.
ADDRESSES: Interested persons are encouraged to submit comments using
the Federal eRulemaking Portal at www.regulations.gov. Follow the
instructions for submitting comments.
Alternatively, interested persons may submit comments, identified
by docket number EERE-2017-BT-TP-0018, by any of the following methods:
1. Federal eRulemaking Portal: www.regulations.gov.
2. Email: to [email protected]. Include
docket number EERE-2017-BT-TP-0018 in the subject line of the message.
No telefacsimiles (faxes) will be accepted. For detailed
instructions on submitting comments and additional information on this
process, see section V of this document (Public Participation).
Although DOE has routinely accepted public comment submissions
through a variety of mechanisms, including postal mail and hand
delivery/courier, the Department has found it necessary to make
temporary modifications to the comment submission process in light of
the ongoing Covid-19 pandemic. DOE is currently accepting only
electronic submissions at this time. If a commenter finds that this
change poses an undue hardship, please contact Appliance Standards
Program staff at (202) 586-1445 to discuss the need for alternative
arrangements. Once the Covid-19 pandemic health emergency is resolved,
DOE anticipates resuming all of its regular options for public comment
submission, including postal mail and hand delivery/courier.
Docket: The docket, which includes Federal Register notices, public
meeting/webinar 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, some documents listed in the index,
such as those containing information that is exempt from public
disclosure, may not be publicly available.
The docket web page can be found at: www.regulations.gov/#docketDetail;D=EERE-2017-BT-TP-0018. The docket web page contains
instructions on how to access all documents, including public comments,
in the docket. See section V (Public Participation) for information on
how to submit comments through www.regulations.gov.
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. Eric Stas, U.S. Department of Energy, Office of the General
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585.
Telephone: (202) 586-5827. Email: [email protected]v.
For further information on how to submit a comment, review other
public comments and the docket, or participate in the webinar, contact
the Appliance and Equipment Standards Program staff at (202) 287-1445
or by email: [email protected].
SUPPLEMENTARY INFORMATION: DOE proposes to incorporate by reference the
following industry standards into title 10 of the Code of Federal
Regulations (CFR) part 431:
Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Standard
920-2020 (I-P), ``2020 Standard for Performance Rating of Direct
Expansion-Dedicated Outdoor Air System Units,'' approved February 4,
2020.
American National Standards Institute (ANSI)/AHRI Standard 1060-2018,
``2018 Standard for Performance Rating of Air-to-Air Exchangers for
Energy Recovery Ventilation Equipment,'' approved 2018.
Copies of AHRI Standard 920-2020 (I-P), and ANSI/AHRI Standard
1060-2018 can be obtained from the Air-conditioning, Heating, and
Refrigeration Institute, 2311 Wilson Blvd., Suite 400, Arlington, VA
22201, (703) 524-8800, or online at: www.ahrinet.org.
ANSI/American Society of Heating, Refrigerating and Air-Conditioning
Engineers (ASHRAE) Standard 37-2009, ``Methods of Testing for Rating
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment,''
ASHRAE approved June 24, 2009.
ANSI/ASHRAE Standard 41.1-2013, ``Standard Method for Temperature
Measurement,'' ANSI approved January 30, 2013.
ANSI/ASHRAE Standard 41.6-2014, ``Standard Method for Humidity
Measurement,'' ANSI approved July 3, 2014.
ANSI/ASHRAE Standard 198-2013, ``Method of Test for Rating DX-Dedicated
Outdoor Air Systems for Moisture Removal Capacity and Moisture Removal
Efficiency,'' ANSI approved January 30, 2013.
Copies of ANSI/ASHRAE Standard 37-2009, ANSI/ASHRAE Standard 41.1-
2013, ANSI/ASHRAE Standard 41.6-2014, and ANSI/ASHRAE Standard 198-2013
can be obtained from the American Society of Heating,
[[Page 36019]]
Refrigerating and Air-Conditioning Engineers, 180 Technology Parkway,
Peachtree Corners, GA 30092, (404) 636-8400, or online at:
www.ashrae.org.
See section IV.M 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 Notice of Proposed Rulemaking
III. Discussion
A. Scope of Applicability
1. Equipment Coverage
2. Scope of Test Procedure
3. Capacity Limit
4. Industry Terminology
B. Test Procedure for Dehumidifying Dedicated Outdoor Air
Systems
1. Industry Consensus Test Standards
2. Efficiency Metrics
a. Dehumidification Metric
b. Heating Metric
c. ISMRE2 and ISCOP2 Weighting Factors
3. Test Method
a. Definitions
b. Break-In Period
c. Airflow-Measuring Apparatus
d. Test Operating Conditions
i. Target Supply and Return Airflow Rates
ii. Units With Cycle Reheat Functions
iii. Target Supply Air Dry-Bulb Temperature
iv. Target Supply Air Dew-Point Temperature
v. Units With Staged Capacity Control
e. Water-Cooled and Water-Source Heat Pump DX-DOAS Equipment
i. Test Conditions for Multiple-Inlet Water Sources
ii. Condenser Liquid Flow Rate
iii. Water Pump Effect
iv. Energy Consumption of Heat Rejection Fans and Chillers
v. Chilled Water Coil Exclusion
f. Defrost Energy Use for Air-Source Heat Pump
g. General Control Setting Requirements
h. Ventilation Energy Recovery Systems
i. Exhaust Air Transfer and Leakage
ii. Purge Angle Setting
iii. Return Air External Static Pressure Requirements
iv. Target Return Airflow Rate
i. Demand-Controlled Ventilation
j. Tolerances for Supply and Return Airflow and External Static
Pressure
k. Secondary Dehumidification and Heating Capacity Tests
l. Corrections
i. Calculation of the Degradation Coefficient
ii. Non-Standard Low-Static Motor
iii. Calculation of Supplementary Heat Penalty
4. Determination of Represented Values
a. Basic Model
b. Sampling Plan Requirements
c. Multiple Refrigerants
d. Alternative Energy-Efficiency Determination Methods
e. Rounding
5. Configuration of Unit Under Test
C. Other Comments
D. Test Procedure Costs, Harmonization, and Other Topics
1. Test Procedure Costs and Impact
2. Harmonization With Industry Standards
3. Other Test Procedure Topics
E. Compliance Date
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
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. Description of Materials Incorporated by Reference
V. Public Participation
A. Participation in the Webinar
B. Procedure for Submitting Prepared General Statements for
Distribution
C. Conduct of the Webinar
D. Submission of Comments
E. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary
I. Authority and Background
Small, large, and very large commercial package air conditioning
and heating equipment are included in the list of ``covered equipment''
for which DOE is authorized to establish and amend energy conservation
standards and test procedures. (42 U.S.C. 6311(1)(B)-(D)) As defined by
the Energy Policy and Conservation Act, as amended (EPCA), ``commercial
package air conditioning and heating equipment'' means air-cooled,
water-cooled, evaporatively-cooled, or water-source (not including
ground-water-source) electrically operated, unitary central air
conditioners and central air conditioning heat pumps for commercial
application. (42 U.S.C. 6311(8)(A)) Industry standards generally
describe unitary central air conditioning equipment as one or more
factory-made assemblies that normally include an evaporator or cooling
coil and a compressor and condenser combination. Units equipped to also
perform a heating function are included as well.\1\ Direct expansion-
dedicated outdoor air systems (DX-DOASes) provide conditioning of
outdoor ventilation air using a refrigeration cycle consisting of a
compressor, condenser, expansion valve, and evaporator,\2\ and
therefore, DOE has initially concluded that DX-DOASes are a category of
commercial package air conditioning and heating equipment subject to
EPCA. An industry consensus test standard has been established for a
subset of DX-DOASes (i.e., dehumidifying DX-DOASes (DDX-DOASes)), which
are the subject of this test procedure proposal. The following sections
discuss DOE's authority to establish test procedures for DDX-DOASes, as
well as relevant background information regarding DOE's proposed
adoption of the industry consensus test standard, and proposed
clarifications to the industry test procedure for this equipment.
---------------------------------------------------------------------------
\1\ See American Society of Heating, Refrigerating and Air-
Conditioning Engineers (ASHRAE) Standard 90.1, ``Energy Standard for
Buildings Except Low-Rise Residential Buildings.''
\2\ Other types of dedicated outdoor air systems are available
that do not utilize direct expansion (e.g., units that use chilled
water, rather than refrigerant, as the heat transfer medium); these
are discussed in section III.B.3.e.v. of this document.
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A. Authority
EPCA,\3\ as amended, among other things, authorizes DOE to regulate
the energy efficiency of a number of consumer products and certain
industrial equipment. Title III, Part C \4\ of EPCA, Public Law 94-163
(42 U.S.C. 6311-6317, as codified), added by Public Law 95-619, Title
IV, Sec. 441(a), established the Energy Conservation Program for
Certain Industrial Equipment, which sets forth a variety of provisions
designed to improve energy efficiency. This covered equipment includes
small, large, and very large commercial package air conditioning and
heating equipment. (42 U.S.C. 6311(1)(B)-(D)) DOE has initially
determined that commercial package air conditioning and heating
equipment includes DX-DOASes. As discussed in section I.B of this
document, DX-DOASes had not previously been addressed in DOE
rulemakings and are not currently subject to Federal test procedures or
energy conservation standards.
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\3\ 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).
\4\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
Under EPCA, DOE's energy conservation program consists essentially
of four parts: (1) Testing, (2) labeling, (3) Federal energy
conservation standards, and (4) certification and enforcement
procedures. Relevant provisions of EPCA specifically include
definitions (42 U.S.C. 6311), energy conservation standards (42 U.S.C.
6313), test procedures (42 U.S.C. 6314),
[[Page 36020]]
labeling provisions (42 U.S.C. 6315), 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(b); 42 U.S.C. 6296), and (2) making representations about the
efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE uses
these test procedures to determine whether the equipment complies with
relevant standards promulgated under EPCA.
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 (b); 42 U.S.C. 6297) DOE may, however, grant waivers
of Federal preemption in limited circumstances 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, the statute also sets forth the criteria and
procedures DOE is required to follow when prescribing or amending test
procedures for covered equipment. Specifically, EPCA requires that any
test procedure prescribed or amended shall be reasonably designed to
produce test results which measure energy efficiency, energy use, or
estimated annual operating cost of covered equipment during a
representative average use cycle and requires that test procedures not
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2))
EPCA requires that the test procedures for commercial package air
conditioning and heating equipment be those generally accepted industry
testing procedures or rating procedures developed or recognized by the
Air-Conditioning, Heating, and Refrigeration Institute (AHRI) or by the
American Society of Heating, Refrigerating and Air-Conditioning
Engineers (ASHRAE), as referenced in ASHRAE Standard 90.1, ``Energy
Standard for Buildings Except Low-Rise Residential Buildings'' (ASHRAE
Standard 90.1). (42 U.S.C. 6314(a)(4)(A)) Further, if such an industry
test procedure is amended, DOE must update its test procedure to be
consistent with the amended industry test procedure, unless DOE
determines, by rule published in the Federal Register and supported by
clear and convincing evidence, that such amended test procedure would
not meet the requirements in 42 U.S.C. 6314(a)(2) and (3), related to
representative use and test burden. (42 U.S.C. 6314(a)(4)(B))
EPCA also requires that, at least once every seven years, DOE
evaluate test procedures for each type of covered equipment, including
commercial package air conditioning and heating equipment to determine
whether amended test procedures would more accurately or fully comply
with the requirements for the test procedures not to 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)-(3)) In addition, if DOE determines that a test procedure
amendment is warranted, it 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 in the Federal Register its determination not to amend the
test procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
As discussed in section I.B of this document, a test procedure for
a subset of DX-DOASes (i.e., DDX-DOASes), was first specified by ASHRAE
Standard 90.1 in the 2016 edition (ASHRAE Standard 90.1-2016). Pursuant
to 42 U.S.C. 6314(a)(4)(B), and following updates to the relevant test
procedures which were referenced in ASHRAE Standard 90.1, DOE is
publishing this NOPR proposing to establish a test procedure for DDX-
DOASes in satisfaction of its aforementioned obligations under EPCA.
B. Background
From a functional perspective, DX-DOASes operate similarly to other
categories of commercial package air conditioning and heat pump
equipment, in that they provide conditioning using a refrigeration
cycle consisting of a compressor, condenser, expansion valve, and
evaporator. DX-DOASes provide ventilation and conditioning of 100-
percent outdoor air to the conditioned space, whereas for typical
commercial package air conditioners that are central air conditioners,
outdoor air makes up only a small portion of the total airflow (usually
less than 50 percent). DX-DOASes are typically installed in addition to
a local, primary cooling or heating system (e.g., commercial unitary
air conditioner, variable refrigerant flow system, chilled water
system, water-source heat pumps)--the DX-DOAS conditions the outdoor
ventilation air, while the primary system provides cooling or heating
to balance building shell and interior loads and solar heat gain.
According to ASHRAE, a well-designed system using a DX-DOAS can
ventilate a building at lower installed cost, reduce overall annual
building energy use, and improve indoor environmental quality.\5\
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\5\ From the June 2018 ASHRAE eSociety Newsletter (Available at:
www.ashrae.org/news/esociety/what-s-new-in-doas-and-refrigerant-research) (Last accessed May 24, 2021).
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On October 26, 2016, ASHRAE published ASHRAE Standard 90.1-2016,
which for the first time specified a test standard and efficiency
standards for DX-DOASes. ASHRAE Standard 90.1-2016 (and the subsequent
2019 edition) defines DX-DOAS as a type of air-cooled, water-cooled, or
water-source factory assembled product that dehumidifies 100% outdoor
air to a low dew point and includes reheat that is capable of
controlling the supply dry-bulb temperature of the dehumidified air to
the designed supply air temperature. This conditioned outdoor air is
then delivered directly or indirectly to the conditioned spaces. It may
precondition outdoor air by containing an enthalpy wheel, sensible
wheel, desiccant wheel, plate heat exchanger, heat pipes, or other heat
or mass transfer apparatus.
Although ASHRAE Standard 90.1-2016 uses the term ``DX-DOAS,'' the
definition of this term provided therein describes a subset of DX-
DOASes, specifically DDX-DOASes. The ASHRAE definition of ``DX-DOAS''
is generally equivalent to the equipment DOE is proposing to define as
DDX-DOAS and for which DOE is proposing to adopt the industry consensus
standard. DDX-DOASes dehumidify air to a low dew point. When operating
in humid conditions, the dehumidification load from the outdoor
ventilation air is a much larger percentage of the total cooling load
for a DDX-DOAS than for a typical commercial air conditioner.
Additionally, compared to a typical commercial air conditioner, the
amount of total cooling (both sensible and latent) is much greater per
pound of air for a DDX-DOAS at design conditions (i.e., the warmest/
most humid expected summer conditions), and a DDX-DOAS is designed to
accommodate greater variation in entering air temperature and humidity
(i.e., a typical commercial air conditioner would not be able to
dehumidify 100-percent outdoor ventilation air to the levels achieved
by
[[Page 36021]]
a DDX-DOAS). Not all DX-DOASes have this dehumidification capability,
which is why DOE is proposing a separate definition. (See section
III.B.2.a of this NOPR for further details.)
The amendment to ASHRAE Standard 90.1 to specify an industry test
standard for equipment that DOE calls DDX-DOAS triggered DOE's
obligations vis-[agrave]-vis test procedures under 42 U.S.C.
6314(a)(4)(B), as outlined previously. On July 25, 2017, DOE published
a request for information (RFI) (the July 2017 ASHRAE TP RFI) in the
Federal Register to collect information and data to consider new and
amended DOE test procedures for commercial package air conditioning and
heating equipment, given the test procedure updates included in ASHRAE
Standard 90.1-2016. 82 FR 34427. As part of the July 2017 ASHRAE TP
RFI, DOE requested comment on several aspects regarding test procedures
for DDX-DOASes in consideration of adopting a new DOE test procedure
for this equipment, including: Incorporation by reference of the
relevant industry test standard(s); efficiency metrics and
calculations, and additional topics that may inform DOE's decisions in
a future test procedure rulemaking.\6\ 82 FR 34427, 34435-34439 (July
25, 2017). On October 25, 2019, ASHRAE published an updated version of
ASHRAE Standard 90.1 (i.e., ASHRAE Standards 90.1-2019), which
maintained the DDX-DOAS provisions as first introduced in ASHRAE
Standard 90.1-2016 without revisions.
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\6\ In the July 2017 ASHRAE TP RFI, DOE referred to DDX-DOASes
simply as ``DOASes.''
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DOE received a number of comments from interested parties in
response to the July 2017 ASHRAE TP RFI, which covered multiple
categories of equipment. Table I-1 lists the commenters relevant to
DDX-DOASes, along with each commenter's abbreviated name used
throughout this NOPR. DOE considered these comments in the preparation
of this NOPR. Discussion of the relevant comments, and DOE's responses,
are provided in the appropriate sections of this document.
Table I-1--Interested Parties Providing DX-DOAS-Related Comments on the
July 2017 ASHRAE Test Procedure RFI
------------------------------------------------------------------------
Name Abbreviation Type \1\
------------------------------------------------------------------------
Air-Conditioning, Heating, and AHRI................. IR
Refrigeration Institute.
Appliance Standards Awareness Project Joint Advocates...... EA
(ASAP), Alliance to Save Energy
(ASE), American Council for an
Energy-Efficient Economy (ACEEE),
Northwest Energy Efficiency Alliance
(NEEA), and Northwest Power and
Conservation Council (NPCC).
Carrier Corporation, part of United Carrier.............. M
Technologies Climate, Controls &
Security (CCS) business.
Goodman Global, Inc.................. Goodman.............. M
The Greenheck Group.................. Greenheck............ M
Ingersoll Rand....................... Ingersoll Rand....... M
Lennox International, Inc............ Lennox............... M
Mitsubishi Electric Cooling & Heating Mitsubishi........... M
\2\.
National Comfort Institute........... NCI.................. IR
Pacific Gas and Electric Company CA IOUs.............. U
(PG&E), Southern California Gas
Company (SoCalGas), San Diego Gas
and Electric (SDG&E), and Southern
California Edison (SCE),
collectively referred to as
California Investor-Owned Utilities
(CA IOUs).
------------------------------------------------------------------------
\1\ EA: Efficiency/Environmental Advocate; IR: Industry Representative;
M: Manufacturer; U: Utility.
\2\ Mitsubishi commented that it fully supports all of the comments
submitted by AHRI on DX-DOAS issues.
On February 14, 2020, DOE published a final rule updating its
procedures for consideration of new and amended energy conservation
standards at 10 CFR part 430, subpart C, appendix A, ``Procedures,
Interpretations, and Policies for Consideration of New or Revised
Energy Conservation Standards and Test Procedures for Consumer Products
and Certain Commercial/Industrial Equipment'' (the Process Rule). 85 FR
8626. As part of the update, the Process Rule now applies explicitly to
commercial and industrial equipment. 10 CFR 431.4. The updated Process
Rule also includes provisions specific to the consideration of new and
amended energy conservation standards and test procedures for covered
equipment subject to the ASHRAE provisions of EPCA. See Process Rule,
10 CFR part 430, subpart C, appendix A, sections 2 and 9.
With respect to DOE's consideration of changes to the relevant
industry consensus test procedure(s) for covered ASHRAE equipment, the
Process Rule now provides that DOE will do so only if it can meet a
very high bar to demonstrate the ``clear and convincing evidence''
threshold. 10 CFR part 430, subpart C, appendix A, section 9(b). Clear
and convincing evidence would exist only where the specific facts and
data made available to DOE regarding a particular ASHRAE amendment
demonstrates that there is no substantial doubt that that the industry
test procedure does not meet the EPCA requirements. Id. DOE will make
this determination only after seeking data and information from
interested parties and the public to help inform DOE's views. DOE will
seek from interested stakeholders and the public data and information
to assist in making this determination, prior to publishing a proposed
rule to adopt a different test procedure. Id.
II. Synopsis of the Notice of Proposed Rulemaking
In this NOPR, DOE is proposing to establish a definition for DX-
DOAS as a category of commercial package air conditioning and heating
equipment and adopt a new test procedure for a subset of DX-DOASes
(i.e., DDX-DOASes), consistent with the industry consensus test
standard as specified in ASHRAE Standard 90.1-2019. The proposed test
procedure applies to all DDX-DOASes for which ASHRAE 90.1-2019
specifies standards, with the exception of ground-water-source DDX-
DOASes, as discussed in section III.A.1 of this NOPR. More
specifically, DOE proposes to update 10 CFR 431.96, ``Uniform test
method for the measurement of energy efficiency of commercial air
conditioners and heat pumps,'' to adopt a new test procedure for DDX-
DOASes as follows: (1) Incorporate by reference AHRI Standard 920-2020
(I-P), ``Performance Rating of
[[Page 36022]]
Direct Expansion-Dedicated Outdoor Air System Units'' (AHRI 920-2020),
the most recent version of the test procedure recognized by ASHRAE
Standard 90.1 for DDX-DOASes, and the relevant industry standards
referenced therein; (2) establish the scope of coverage for the DDX-
DOAS test procedure; (3) add definitions for DX-DOASes and DDX-DOASes,
as well as additional terminology required by the test procedure; (4)
adopt the integrated seasonal moisture removal efficiency, as measured
according to the most recent applicable industry standard (ISMRE2), and
integrated seasonal coefficient of performance (ISCOP2), as measured
according to the most recent applicable industry standard, as energy
efficiency descriptors for dehumidification and heating mode,
respectively; and (5) establish representation requirements. DOE
proposes to add a new Appendix B to Subpart F of Part 431, titled
``Uniform test method for measuring the energy consumption of
dehumidifying direct expansion-dedicated outdoor air systems,''
(Appendix B) that would include the new test procedure requirements for
DDX-DOASes. In conjunction, DOE proposes to amend Table 1 in 10 CFR
431.96 to identify the newly added Appendix B as the applicable test
procedure for testing DDX-DOASes. DOE has tentatively determined that
the proposed test procedure would not be unduly burdensome to conduct.
DOE's proposed actions are summarized in Table II.1 and addressed
in detail in section III of this document.
Table II.1--Summary of Proposed Test Procedure for DDX-DOASes
------------------------------------------------------------------------
Proposed test procedure Attribution
------------------------------------------------------------------------
Incorporates by reference AHRI 920-2020 and Adopt industry test
other relevant industry test standards procedure.
referenced by that standard. AHRI 920-2020
includes:
--test methods for DDX-DOAS with and
without ventilation energy recovery
systems (VERS);
--test operating conditions, including
Standard Rating Conditions, simulated
ventilation air conditions for
optional test methods for DDX-DOASes
with VERS, supply air target
conditions, supply and return airflow
rates, and external static pressure;
--testing instrumentation and apparatus
instructions;
--test operating and condition
tolerances \7\;
--a list of components that must be
present for testing; and
--provisions for testing units with
certain optional features.
Defines DX-DOASes as covered equipment Establish equipment
which meet the EPCA definition for small, coverage.
large, or very-large commercial package
air conditioning and heating equipment.
Defines the scope of coverage of the test Clarify scope of test
procedure, including defining DDX-DOASes procedure.
to distinguish them from other kinds of
equipment and a capacity limit based on
moisture removal capacity (MRC).
Adopts ISMRE2 and ISCOP2 as the seasonal Adopt industry test
efficiency descriptors for procedure.
dehumidification and heating mode,
respectively, as specified in AHRI 920-
2020.
Provides minor corrections and additional Clarify instructions in the
instruction consistent with AHRI 920-2020 industry test procedure.
by:
--specifying the external head pressure
requirements for DDX-DOASes with integral
water pumps;
--specifying general control setting
requirements;
--correcting a typographical error in
the calculation of the degradation
coefficient; and
--providing a missing definition
necessary for the interpretation of
the airflow setting instructions.
Specifies representation requirements, Provide for representations
including a basic model definition, of energy efficiency
sampling plan requirements, and use of consistent with other
alternative energy-efficiency commercial air conditioner/
determination methods (AEDMs). heat pump equipment.
------------------------------------------------------------------------
III. Discussion
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\7\ ``Test operating tolerance'' refers to the maximum
permissible range that a measurement may vary over a specified test
interval. ``Test condition tolerance'' refers to the maximum
permissible difference between the average value of the measured
test parameter and the specified test condition.
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The following sections discuss DOE's proposal to define DX-DOASes
as a category of small, large and extra-large commercial package air
conditioning and heating equipment and to adopt a new test procedure
for DDX-DOASes, a subset of DX-DOASes, and address relevant comments
received in response to specific issues DOE raised in the July 2017
ASHRAE TP RFI. Commenters' references to ``DX-DOASes'' or ``DOASes''
have been changed to ``DDX-DOASes'' where DOE understands the
commenters to be specifically discussing DX-DOASes that would meet the
dehumidification performance criterion as proposed.
A. Scope of Applicability
1. Equipment Coverage
As discussed, DOE has initially determined that DX-DOASes are a
category of small, large, and very large commercial package air
conditioning and heating equipment and, therefore, are covered
equipment under EPCA. (42 U.S.C. 6311(1)(B)-(D)) DX-DOASes operate
similarly to more typical commercial package air conditioning equipment
in that they provide conditioning of outdoor ventilation air using a
refrigeration cycle consisting of a compressor, condenser, expansion
valve, and evaporator. However, DX-DOASes are designed to provide
ventilation and conditioning of 100-percent outdoor air, while outdoor
air makes up only a small portion of the total airflow for typical
commercial package air conditioning and heating equipment (e.g.,
usually less than 50 percent).
As discussed further in section III.A.4 of this document, industry
provides several definitions for DX-DOASes, but DOE notes that the
industry definitions for ``DX-DOAS'' specifically refer to the DDX-
DOASes that are covered by the scope of those industry test standards,
which does not include non-dehumidifying (i.e., sensible-only) DX-
DOASes that exist on the market.
In this NOPR, DOE is proposing to define ``direct expansion-
dedicated outdoor air system, or DX-DOAS,'' as a category of small,
large, or very large commercial package air conditioning and heating
equipment which is capable of providing ventilation and conditioning of
100-percent outdoor air or marketed in materials (including but not
limited to, specification sheets, insert sheets, and online materials)
as having such capability. This proposed definition is based, in part,
on the definition in section 3.6 of AHRI 920-
[[Page 36023]]
2020, as discussed in section III.A.4 of this document.
The proposed definition of DX-DOAS would include all air-cooled,
air-source heat pump, and water-cooled equipment subcategories
specified in ASHRAE Standard 90.1. For water-source heat pump
equipment, ASHRAE Standard 90.1 includes three configurations--ground-
source, closed loop; ground-water-source; and water-source. The EPCA
definition for ``commercial package air conditioning and heating
equipment'' specifically excludes ground-water-source equipment (42
U.S.C. 6311(8)(A)), so in proposing to define (at 10 CFR 431.92) DX-
DOAS as a category of small, large, or very large commercial package
air conditioning and heating equipment, ground-water-source DX-DOASes
would be excluded from coverage under EPCA.
Issue-1: DOE requests comment on the proposed definition for
``direct expansion-dedicated outdoor air system.'' DOE also requests
comment on any additional characteristics not yet considered that could
help to distinguish DX-DOASes from other commercial package air
conditioning and heating equipment.
2. Scope of Test Procedure
DOE is proposing to establish a test procedure for a subset of DX-
DOASes (i.e., DDX-DOASes). When operating in humid conditions, the
dehumidification load is a much larger percentage of the total cooling
load for a DDX-DOAS than for a typical commercial package air
conditioning system. DDX-DOASes in particular handle a significantly
higher amount of total cooling (both sensible and latent) per pound of
air at design conditions (i.e., the warmest or most humid expected
summer conditions), and a DDX-DOAS is designed to accommodate greater
variation in entering air temperature and humidity, because outdoor
conditions can vary much more than typical indoor conditions. As
discussed, not all DX-DOASes are designed to dehumidify outdoor air at
the most humid expected summer conditions to a level consistent with
comfortable indoor conditions, such as a dew point temperature less
than 55 [deg]F (e.g., sensible-only cooling \8\ DX-DOASes). AHRI stated
that sensible-only 100-percent outdoor air units should not be covered
by ANSI/AHRI 920-2015 because they are not intended to dehumidify the
ventilation air. (AHRI, No. 11 at pp. 10-11) \9\
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\8\ ``Sensible cooling'' refers to the process of cooling air by
reducing its dry bulb temperature without changing its moisture
content.
\9\ A notation in the form ``AHRI, No. 11 at pp. 10-11''
identifies a written comment: (1) Made by AHRI; (2) recorded in
document number 11 that is filed in the docket of this test
procedure rulemaking (Docket No. EERE-2017-BT-TP-0018) and available
for review at www.regulations.gov; and (3) which appears on pages 10
through 11 of document number 11.
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Because DOE is aware of sensible-only DX-DOASes, DOE aims to
further delineate those DX-DOASes that would be subject to the proposed
test procedure (i.e., DDX-DOASes). Section 2.2 of AHRI 920-2020
explicitly excludes ``Sensible-only 100% Outdoor Air Units'' from the
scope of its test standard. Accordingly, DOE proposes to define DDX-
DOASes (the subject of this proposed test procedure) in 10 CFR 431.92
as those DX-DOASes specifically having the capability to dehumidify air
to a dew point of 55 [deg]F when operating under Standard Rating
Condition A as specified in Table 4 or Table 5 of AHRI 920-2020 with a
barometric pressure of 29.92 in Hg. The 55 [deg]F dew point is
specified in ANSI/AHRI 920-2015 and AHRI 920-2020 as the maximum dew
point temperature for the supply air for the dehumidification mode
tests.\10\ This maximum dew point temperature requirement for DDX-
DOASes provides a key differentiator from other DX-DOASes, which
typically cannot dehumidify 100-percent outdoor air to a dew point this
low. This element is consistent with the definition in AHRI 920-2020.
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\10\ AHRI 920-2020 acknowledges the influence of barometric
pressure on humidity ratio for the inlet air conditions specified in
terms of dry bulb and wet bulb temperature, allowing an upward
adjustment of the maximum supply air dew point temperature that must
be achieved, such that the moisture removal rate matches that which
would occur at standard barometric pressure when supplying 55 [deg]F
dew-point supply air--this maximum supply air dew point increases
linearly as barometric pressure decreases, up to 57.3 [deg]F at the
minimum-allowed 13.7 psia test pressure.
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AHRI 920-2020 does not specify at what airflow the dehumidification
element is to be evaluated. DOE proposes to include within the proposed
definition of DDX-DOAS that the DDX-DOAS be capable of providing the
specified dehumidification capability for any portion of the range of
air flow rates advertised in manufacturer materials. This provision
would provide additional specificity to the definition found in AHRI
920-2020 to account for manufacturers that may specify a range of
airflows for a given model.
As proposed, the test procedure would apply to DDX-DOASes within
the capacity limits as discussed in the following section.
Issue-1: DOE requests comment on the proposed definition for
``dehumidifying direct expansion-dedicated outdoor air system.''
Specifically, DOE requests comment on the proposed criteria for
distinguishing a ``dehumidifying direct expansion-dedicated outdoor air
system'' from a ``direct expansion-dedicated outdoor air system'' more
generally. DOE also requests comment on any additional characteristics
not yet considered that could help to distinguish DDX-DOASes from DX-
DOASes more generally.
3. Capacity Limit
As stated, EPCA defines as covered equipment small, large, and very
large commercial package air conditioning and heating equipment. (42
U.S.C. 6311(1)(B)-(D)) EPCA defines ``small commercial package air
conditioning and heating equipment'' as commercial package air
conditioning and heating equipment that is rated below 135,000 Btu per
hour (cooling capacity). (42 U.S.C. 6311(8)(B)) The term ``large
commercial package air conditioning and heating equipment'' means
commercial package air conditioning and heating equipment that is
rated--(i) at or above 135,000 Btu per hour; and (ii) below 240,000 Btu
per hour (cooling capacity). (42 U.S.C. 6311(8)(C)) The term ``very
large commercial package air conditioning and heating equipment'' means
commercial package air conditioning and heating equipment that is
rated--(i) at or above 240,000 Btu per hour; and (ii) below 760,000 Btu
per hour (cooling capacity). (42 U.S.C. 6311(8)(D))
In response to the July 2017 ASHRAE TP RFI, AHRI commented that
DOE's regulations for DDX-DOASes should be capped at a reasonable
capacity, similar to the 760,000 Btu/h limit for commercial packaged
air conditioning equipment. AHRI stated that laboratory limitations may
limit testing using ANSI/AHRI 920-2015 to 300 lbs. of moisture per hour
at Standard Rating Condition A and to units not physically larger than
more typical commercial package air conditioning and heating equipment
with a capacity of 760,000 Btu/h. The commenter also stated that the
market for these larger, typical commercial package air conditioning
equipment and DDX-DOAS units (with a capacity greater than 760,000 Btu/
h, or equivalent) is very small and customized. AHRI stated that the
customization helps customers minimize energy consumption for their
application. (AHRI, No. 11 at p. 20)
As discussed, DOE has tentatively concluded that DX-DOASes meet the
EPCA definition for ``commercial package air conditioning and heating
equipment,'' and, thus, are to be considered as a category of that
covered equipment. (42 U.S.C. 6311(8)(A)) The upper capacity limit of
commercial
[[Page 36024]]
package air conditioning subject to the DOE test procedures is 760,000
Btu per hour, based on the definition of ``very large commercial
package air conditioning and heating equipment.'' (42 U.S.C.
6311(8)(D))
For DDX-DOASes specifically, AHRI 920-2020 does not provide a
method for determining capacity in terms of Btu per hour, but instead,
it specifies a determination of capacity in terms of moisture removal
capacity (MRC). DOE proposes to translate the upper capacity for
coverage of commercial package air conditioning and heating units
established in EPCA (i.e., 760,000 Btu per hour) from Btu per hour to
MRC for DDX-DOASes. Specifically, DOE is proposing, consistent with
section 6 of AHRI 920-2020, to translate the upper limit from Btu per
hour to MRC of the DDX-DOAS when delivering dehumidified supply air at
a 55 [deg]F dew point. Manufacturers would use their tested value of
MRC to determine if a DDX-DOAS is subject to the test procedure.
To translate Btu per hour to MRC, DOE calculated the maximum
airflow that could be supplied at a 55 [deg]F dewpoint for Standard
Rating Condition A as specified in Table 4 and Table 5 of AHRI 920-2020
by cooling and dehumidifying it with an evaporator with a refrigeration
capacity of 760,000 Btu per hour. DOE calculated this based on air
entering the evaporator at Standard Rating Condition A (95 [deg]F dry-
bulb temperature and 78 [deg]F wet-bulb temperature) and air exiting
the evaporator at 55 [deg]F dew point and 95-percent relative humidity
at a standard barometric pressure of 29.92 in Hg. DOE then calculated
the MRC that corresponds to those conditions. Based on these
calculations, DOE is proposing to limit the scope of this proposed test
procedure to DDX-DOAS units with a MRC less than 324 lbs. per hour
based on Standard Rating Condition A as specified in Table 4 or Table 5
of AHRI 920-2020.
Issue-2: DOE seeks comment on its translation of Btu per hour to
MRC and specifically its proposal to translate the upper capacity limit
for DDX-DOASes such that a model would be considered in scope if it has
an MRC less than 324 lbs. per hour.
4. Industry Terminology
As stated, DOE is proposing definitions for DX-DOAS and DDX-DOAS
following a review of industry standards and consistent with the
applicability of the relevant industry testing standard. Both ANSI/AHRI
920-2015 and ANSI/ASHRAE 198-2013 include definitions for ``DX-
Dedicated Outdoor Air System Units.'' Section 3.3 of ANSI/AHRI 920-2015
defines ``DX-Dedicated Outdoor Air System Units'' as a type of air-
cooled, water-cooled, or water-source factory assembled product which
dehumidifies 100-percent outdoor air to a low dew point, and includes
reheat that is capable of controlling the supply dry-bulb temperature
of the dehumidified air to the designed supply air \11\ temperature.
This conditioned outdoor air is then delivered directly or indirectly
to the conditioned space(s). It may pre-condition outdoor air by
containing an enthalpy wheel, sensible wheel, desiccant wheel, plate
heat exchanger, heat pipes, or other heat or mass transfer apparatus.
This is the same definition used in ASHRAE Standard 90.1-2019.
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\11\ ``Supply air'' for a DDX-DOAS refers to conditioned air
that is supplied to the conditioned space.
---------------------------------------------------------------------------
Section 3 of ANSI/ASHRAE 198-2013 defines a ``DX Dedicated Outdoor
Air Systems Unit (DX-DOAS)'' as a type of air-cooled, water-cooled, or
water-source factory-assembled product that is capable of dehumidifying
100-percent outdoor air to a low dew point and may be capable of
controlling the dry-bulb temperature of the dehumidified air to the
designed supply air temperature. This conditioned outdoor air may be
delivered directly or indirectly to the conditioned space(s). It may
pre-condition outdoor air prior to direct expansion cooling by
incorporating an enthalpy wheel, sensible wheel, desiccant wheel, plate
heat exchanger, heat pipes, or other heat or mass transfer apparatus.
The product may also include a supplementary heating system for use
when outdoor air requires heating beyond the capability of the
refrigeration system and/or other heat transfer apparatus.
As part of the July 2017 ASHRAE TP RFI, DOE requested comment on
certain aspects of these two industry definitions of dedicated outdoor
air systems. 82 FR 34427, 34435-34436 (July 25, 2017). On February 4,
2020, AHRI published AHRI 920-2020, which made changes to the
definition of ``Dedicated Outdoor Air System Unit'' as compared to the
definition in ANSI/AHRI 920-2015 (and ASHRAE Standard 90.1-2019).
Section 3.6 of AHRI 920-2020 defines ``Dedicated Outdoor Air System
Unit'' as a type of air-cooled, evaporatively-cooled, or water-cooled
air-conditioner, or an air-source or water source heat pump, that is a
factory assembled product designed and marketed and sold to provide
ventilation and dehumidification of 100% outdoor air, is capable of
dehumidifying air to a 55 [deg]F dew point when operating under
Standard Rating Condition A as specified in Table 4 or Table 5 of this
test standard with a barometric pressure of 29.92 in Hg, and may
include reheat. It may include pre-conditioning of outdoor air using an
enthalpy wheel, sensible wheel, desiccant wheel, plate heat exchanger,
heat pipes, or other heat or mass transfer apparatus. Heating
components are optional and may include electrical resistance, steam,
hot water, or gas heat. In addition, it may provide for air cleaning or
may include mixing box or economizer dampers to allow return air to be
intermittently used as allowed by the controls.
Both ANSI/AHRI 920-2015 and ANSI/ASHRAE 198-2013 address equipment
that dehumidifies (or is capable of dehumidifying) 100-percent outdoor
air to a low dew point. As discussed, in its review of available
equipment, DOE found units marketed as ``dedicated outdoor air
systems,'' and other units marketed for ``100-percent outdoor air''
applications, both of which can also operate with less than 100-percent
outdoor air. Such units have a return air damper that allows modulating
the amount of return air that is recirculated from the conditioned
space and mixed with the incoming outdoor air before the mixed air is
conditioned. More typical commercial package air conditioning equipment
also often incorporates a similar damper to mix return air and outdoor
air. Additionally, like the industry definitions for dedicated outdoor
air systems, which DOE notes would be DDX-DOASes as that term is
proposed to be defined, some categories of commercial package air
conditioning equipment can dehumidify 100-percent outdoor air, although
typically not to a dew point as low as the industry specification for
DDX-DOASes.
As part of the July 2017 ASHRAE TP RFI, DOE requested information
on the range of the maximum percentage of return air intake relative to
total airflow of models of equipment that DOE generally referred to as
``DOASes'' in order to determine whether the maximum return air
percentage is an important distinguishing feature of DDX-DOASes. DOE
also requested information on the difference in dehumidification
capabilities of more typical commercial package air conditioning
equipment and equipment that DOE referred to as DOASes when operating
with 100-percent outdoor air. 82 FR 34427, 34435 (July 25, 2017).
Ingersoll Rand and Carrier commented that there are not one or two
features or criteria that definitively distinguish DDX-DOASes from more
[[Page 36025]]
typical commercial package air conditioning equipment. (Ingersoll Rand,
No. 12 at p. 2; Carrier, No. 6 at p. 2) AHRI and Carrier commented that
there may be several potential applications for DDX-DOASes, some of
which may not be 100-percent outdoor air. (AHRI, No. 11 at p. 9;
Carrier, No. 6 at p. 2) AHRI and Ingersoll Rand stated, for example,
that DDX-DOASes may be supplied with recirculation dampers that allow
them to efficiently dehumidify recirculated air when the building is
unoccupied. AHRI stated that, as a result, it is not possible to select
a specific crossover percentage of return air intake relative to total
airflow that would differentiate DDX-DOASes from more typical
commercial package air conditioning equipment. (AHRI, No. 11 at p. 9;
Ingersoll Rand, No. 12 at p. 2) Goodman supported AHRI's position,
adding that when the return air intake relative to the total airflow is
less than 10-30 percent, ANSI/AHRI 920-2015 is more appropriate than
ANSI/AHRI 340/360 \12\ in non-western climates. (Goodman, No. 14 at p.
2)
---------------------------------------------------------------------------
\12\ ANSI/AHRI Standard 340/360, ``Performance Rating of
Commercial and Industrial Unitary Air-conditioning and Heat Pump
Equipment'' (Available at: www.ahrinet.org/) (Last accessed April
19, 2021).
---------------------------------------------------------------------------
As discussed, not all DX-DOASes are designed to provide
dehumidification (to a low dew point) over larger variation in entering
air temperature and humidity. As such, DOE is proposing to define DDX-
DOAS to distinguish such equipment from DX-DOAS more generally, as
provided in the previous sections. The DDX-DOAS definition is
consistent with the definition in section 3.6 of AHRI 920-2020 for the
equipment subject to the scope of that industry test standard.
DOE noted in the July 2017 ASHRAE TP RFI that one difference
between the definitions in ANSI/ASHRAE 198-2013 and ANSI/AHRI 920-2015
(and now AHRI 920-2020) is related to reheat. ANSI/AHRI 920-2015
specifies that a Direct Expansion-Dedicated Outdoor Air System Unit
includes reheat, which is used to raise the temperature of cooled and
dehumidified air to a design supply air temperature. The ANSI/ASHRAE
198-2013 definition provides that a DX Dedicated Outdoor Air Systems
Unit, as defined by that industry standard, may have reheat but does
not require reheat. DOE requested comment on whether and how reheating
functionality should be included in the DDX-DOAS definition. 82 FR
34427, 34435-34436 (July 25, 2017).
In response to the July 2017 ASHRAE TP RFI, AHRI and Greenheck
commented that while capturing reheat performance in the test procedure
for DDX-DOAS equipment is an important aspect to many installations,
some building HVAC designs incorporating DDX-DOAS equipment operate
without any reheat capabilities. AHRI and Greenheck suggested that the
definition of DDX-DOAS should not require reheat, as it is important
for owners and designers to be able to select 100-percent outdoor air
units with varying amounts of reheat or no reheat. (AHRI, No. 11 at pp.
10-11, 20-21; Greenheck, No. 13 at p. 2) AHRI further commented that
DDX-DOAS design and optimum efficiency varies with climate and
application, and that the design is often customized to accommodate the
different needs of different applications. AHRI asserted that
regulations must allow for these differences to avoid increasing energy
consumption for a given project. (AHRI, No. 11 at p. 20-21) Greenheck
commented that the supplementary heat penalty included in ANSI/AHRI
920-2015 unfairly penalizes units without reheat, and Greenheck
suggested two options for rating units without reheat. (Greenheck, No.
13 at pp. 2-3). Carrier also commented that reheat functionality is an
application issue and is not applicable to the definition in a test
standard. (Carrier, No. 6 at p. 3)
DOE recognizes that the optimum-efficiency DDX-DOAS design varies
with climate and application. DOE also understands that the
supplementary heat penalty in ANSI/AHRI 920-2015 is not representative
of the way that units without reheat are used in the field. As is
discussed in section III.B.2.a of this document, as part of AHRI 920-
2020, AHRI modified the ISMRE metric to remove the supplementary heat
penalty in recognition that some installation conditions may not
require reheating. As is discussed in section III.B.1 of this document,
this metric was re-designated in AHRI 920-2020 as ISMRE2. AHRI 920-2020
also includes a separate application rating metric, ISMRE270, to
account for installations where reheating is required. Moreover, the
updated definition in AHRI 920-2020 recognizes that there are units
without reheat. As such, DOE is not proposing to include a reheat
requirement in the DX-DOAS or DDX-DOAS definition, consistent with AHRI
920-2020.
Because of the difference in terminology between the proposed DOE
test procedure and the relevant industry standards, DOE proposes to
include a section 2.3(a) in its proposed Appendix B indicating that the
different synonymous terms all refer to dehumidifying direct expansion-
dedicated outdoor air system as defined in 10 CFR 431.92.
Issue-3: DOE requests comment on its proposal to clarify what terms
are synonymous with DDX-DOAS.
B. Test Procedure for Dehumidifying Dedicated Outdoor Air Systems
Pursuant to EPCA, in response to the DDX-DOAS-related updates to
ASHRAE 90.1-2016 (maintained in ASHRAE 90.1-2019) and updates to the
industry test standard referenced in ASHRAE 90.1, DOE proposes to adopt
a test procedure for DDX-DOASes that incorporates by reference the
latest applicable industry consensus test standards.
In the following sections, DOE presents analysis and discussion of
several test procedure issues and proposes a test procedure for DDX-
DOASes. As discussed in more detail in the following sections, DOE has
initially determined that the proposed test procedure for DDX-DOASes
would be representative of an average use cycle and not be unduly
burdensome to conduct.
DOE is adopting the generally accepted industry testing procedures
for DDX-DOASes developed by AHRI (i.e., AHRI 920-2020) and referenced
by ASHRAE Standard 90.1, with the following modifications as discussed
in this NOPR:
[ssquf] Using the nomenclature DDX-DOAS, rather than DX-DOAS, to
define the equipment subject to the test procedure;
[ssquf] Defining an upper limit of capacity consistent with EPCA's
definition of very large commercial package air conditioning and
heating equipment;
[ssquf] Defining ``non-standard low-static fan motor,'' in order to
determine the appropriate airflow setting procedure;
[ssquf] Specifying the external head pressure requirements for
testing DDX-DOASes with integral water pumps;
[ssquf] Requiring that control settings remain unchanged for all
Standard Rating Conditions once system set-up has been completed prior
to testing;
[ssquf] Specifying requirements for testing equipment available
with multiple refrigerant options; and
[ssquf] Correcting a typographical error within one of the
equations.
1. Industry Consensus Test Standards
As first established in ASHRAE 90.1-2016, ASHRAE Standard 90.1-2019
specifies separate equipment classes for DDX-DOASes \13\ and sets
minimum
[[Page 36026]]
efficiency levels using the integrated seasonal moisture removal
efficiency (ISMRE) metric for all DDX-DOAS classes and also the
integrated seasonal coefficient of performance (ISCOP) metric for air-
source heat pump and water-source heat pump DDX-DOAS classes. ASHRAE
Standard 90.1-2019 specifies that both metrics are to be measured in
accordance with ANSI/AHRI Standard 920-2015, ``Performance Rating of
DX-Dedicated Outdoor Air System Units'' (ANSI/AHRI 920-2015). ANSI/AHRI
920-2015 specifies the method for testing DDX-DOASes, in part, through
a reference to ANSI/ASHRAE Standard 198-2013, ``Method of Test for
Rating DX-Dedicated Outdoor Air Systems for Moisture Removal Capacity
and Moisture Removal Efficiency'' (ANSI/ASHRAE 198-2013).
---------------------------------------------------------------------------
\13\ As discussed, the term DX-DOAS as defined by ASHRAE 90.1-
2019 is equivalent to the term DDX-DOAS as defined by DOE in this
NOPR.
---------------------------------------------------------------------------
ANSI/AHRI 920-2015 specifies Standard Rating Conditions (i.e.,
instructions on setting air and liquid flow rates, and equations for
calculating ISMRE and ISCOP). Table 2 and Table 3 of ANSI/AHRI 920-2015
provide outdoor and return air conditions for four Standard Rating
Conditions for the dehumidification test and two Standard Rating
Conditions for the heating test for heat pump DDX-DOASes. These tables
also provide condenser cooling water temperatures (for both cooling
tower and chilled water condensers) for water-cooled (cooling-only)
DDX-DOASes and water temperatures for water-source, ground-source
closed-loop, and ground-water source \14\ heat pump DDX-DOASes.
---------------------------------------------------------------------------
\14\ As discussed in section III.A.1 of this NOPR, the EPCA
definition for ``commercial package air conditioning and heating
equipment'' specifically excludes ground-water-source equipment (42
U.S.C. 6311(8)(A)). Accordingly, DOE is proposing to exclude this
equipment from the scope of applicability of the test procedure.
---------------------------------------------------------------------------
ANSI/ASHRAE 198-2013 includes requirements on instrumentation, test
set-up, tolerances, method of test, and calculations for moisture
removal capacity (MRC), moisture removal efficiency (MRE), heating
capacity (qhp) and heating coefficient of performance (COP). The MRE
for the dehumidification test is calculated for Standard Rating
Conditions \15\ A, B, C, and D of Table 2 or Table 3 of ANSI/AHRI 920-
2015 for air-cooled, water-cooled, and water-source heat pump DDX-
DOASes. Similarly, COP is calculated for the heating mode test for
Standard Rating Conditions E and F of Table 2 or Table 3 of ANSI/AHRI
920-2015 for heat pump DDX-DOASes. The MRE and COP values are
subsequently used to calculate ISMRE and ISCOP using weights that
correspond to temperature bin data for representative cities in the
United States.
---------------------------------------------------------------------------
\15\ Standard Rating Conditions in the AHRI 920 test procedure
represent full-load and part-load operating conditions for testing
DX-DOASes. Standard Rating Condition A represents full-load
operation in dehumidification mode, whereas Standard Rating
Conditions B-D represent part-load operation in dehumidification
mode. Standard Rating Condition F represents full-load operation in
heat pump mode at low temperatures, and Standard Rating Condition E
represents full-load operation in heat pump mode at high
temperatures.
---------------------------------------------------------------------------
DOE notes that AHRI recently revised AHRI 920 and published an
updated version on February 4, 2020, AHRI Standard 920-2020 (I-P),
``Performance Rating of Direct Expansion Dedicated Outdoor Air System
Units'' (AHRI 920-2020). AHRI 920-2020, which continues to reference
ANSI/ASHRAE 198-2013, includes revisions that DOE has initially
determined improve the representativeness, repeatability, and
reproducibility of the test methods while also reducing test burden.
These revisions include, among other things, the following: (1)
Expanded scope of coverage of the test procedure by no longer imposing
an upper limit of 97 lbs/hr on DDX-DOAS MRC, thereby making the test
procedure applicable to all DDX-DOASes subject to standards under
ASHRAE Standard 90.1; (2) revised outdoor air dry-bulb temperature
conditions, external static pressures, humidity conditions, and
weighting factors for ISMRE and ISCOP, which were redesignated as
ISMRE2 and ISCOP2, respectively; (3) revised calculations for achieving
the target supply air conditions for units with staged capacity
control; (4) added a supplementary cooling penalty when the supply air
dry-bulb temperature is greater than 75 [deg]F in dehumidification
mode; (5) removed a supplementary heat penalty for the efficiency
metric ISMRE2 when the supply air dry-bulb temperature is less than 70
[deg]F in dehumidification mode; \16\ (6) revised condenser water
conditions for water-cooled and water-source heat pump DDX-DOASes; (7)
added requirements for supply air dew point temperature; \17\ (8) added
requirements for outdoor coil liquid flow rate; (9) provided additional
test unit, test facility, instrumentation, and apparatus set-up
provisions; (10) revised test methods for DDX-DOASes equipped with
VERS; (11) added requirements for relief-air-cooled DDX-DOASes and DDX-
DOASes equipped with desiccant wheels; and (12) included requirements
for secondary capacity tests.
---------------------------------------------------------------------------
\16\ As discussed in section III.B.3.a of this NOPR, AHRI 920-
2020 additionally provides a method for calculating
ISMRE270, an application metric for the dehumidification
efficiency with the inclusion of the supplementary heat penalty. The
subscript ``70'' indicates the inclusion of energy use from any
supplementary heat that is required to raise the supply air dry bulb
temperature to 70 [deg]F.
\17\ Dew point is the temperature below which water begins to
condense from the water vapor state in humid air into liquid water
droplets. Dew point varies with humidity (e.g., a low dew point
indicates low humidity and vice versa) and is, therefore, used to
specify the humidity of the supply air.
---------------------------------------------------------------------------
DOE carefully reviewed both ANSI/AHRI 920-2015 and ANSI/ASHRAE 198-
2013, as well as the latest changes in AHRI 920-2020, in consideration
of this NOPR. In the following sections, DOE discusses the proposed
definition for DDX-DOASes, scope of the test procedure, efficiency
metrics, test methods (including the updates to AHRI 920 in the 2020
version listed in the prior paragraph), and sampling requirements.
Generally, DOE incorporates industry standards into the regulations by
reference to the standard. In this NOPR, DOE has proposed to
incorporate by reference AHRI 920-2020.
DOE is also proposing to incorporate by reference several industry
standards that are referenced by AHRI 920-2020, as shown in Table III-
1.
Table III-1--Additional Industry Standards Proposed To Be Incorporated
by Reference
------------------------------------------------------------------------
Section(s) in AHRI 920-2020
Industry standard that reference this industry
standard
------------------------------------------------------------------------
ANSI/ASHRAE 198-2013...................... Section 5; Section 6;
Appendix C.
ANSI/ASHRAE 37-2009....................... Section 5; Section 6;
Appendix C.
ANSI/ASHRAE 1060-2018..................... Section C4.
ANSI/ASHRAE 41.1-2013..................... Section C3.3.1.
ANSI/ASHRAE 41.6-2014..................... Section C3.1.3.2.
------------------------------------------------------------------------
In response to the July 2017 ASHRAE TP RFI, AHRI commented that the
ISMRE and ISCOP levels specified for DDX-DOASes in ASHRAE 90.1-2016
will need adjustment if changes to the test procedure negatively impact
these values (AHRI, No. 11 at p. 20).
This NOPR proposes to incorporate by reference the latest version
of the industry test procedure for DDX-DOASes which is recognized by
ASHRAE Standard 90.1: AHRI 920 (the latest version being AHRI 920-
2020). When the test procedures referenced in ASHRAE Standard 90.1 are
updated, EPCA requires DOE to amend the Federal test procedures for
such covered ASHRAE equipment (which manufacturers are required to use
in order to certify compliance with energy
[[Page 36027]]
conservation standards mandated under EPCA) to be consistent with the
amended industry consensus test procedure. (42 U.S.C. 6314(a)(4)(B))
The energy efficiency standards specified in ASHRAE Standard 90.1
are based on ANSI/AHRI 920-2015 and ANSI/ASHRAE 198-2013. However, the
amendments adopted in AHRI 920-2020 result in changes to the measured
efficiency metrics as compared to the results under ANSI/AHRI 920-2015.
As discussed, DOE has not established in its regulations energy
conservation standards specifically for DDX-DOASes. DOE will address
any potential differences in the measured energy efficiency under the
most recent industry test procedure as compared to the industry test
procedure on which the ASHRAE Standard 90.1 levels are based at such
time as DOE evaluates the ASHRAE Standard 90.1 levels for DDX-DOASes
(i.e., by developing an appropriate crosswalk, as necessary).
Specifically, DOE intends to request that DDX-DOAS manufacturers
provide any data and/or analysis that indicates whether and how much
the measured rating of DDX-DOASes would be expected to change under the
most recent version of the industry consensus test standard.
Issue-4: DOE requests comment and data on the development of a
crosswalk from the efficiency levels in ASHRAE Standard 90.1 based on
ANSI/AHRI 920-2015 to efficiency levels based on AHRI 920-2020. DOE is
specifically seeking data on how dehumidification and heating
efficiency ratings for a given DDX-DOAS model are impacted when
measured using AHRI 920-2020 as compared to ANSI/AHRI 920-2015.
2. Efficiency Metrics
a. Dehumidification Metric
ASHRAE 90.1-2016 adopted a dehumidification efficiency metric for
DDX-DOASes. Specifically, ASHRAE 90.1-2016 uses ISMRE, as presented in
section 3.10 of ANSI/AHRI 920-2015, as a seasonal efficiency metric
calculated as a weighted average of MRE for four different
dehumidification rating conditions. MRE for each test condition is the
MRC for that condition divided by electric power input, including
consideration of electric resistance reheat if needed to raise supply
air temperature to 70 [deg]F (i.e., ``supplementary heat''). MRC
represents the rate at which the DDX-DOAS removes humidity from the air
in pounds of moisture per hour. As discussed further in section
III.B.2.c of this document, AHRI indicated that the seasonal weighting
factors for determining ISMRE, as specified in ANSI/AHRI 920-2015, were
developed based on climate data from a sample of twelve cities chosen
to be representative of a wide range of climatic data in the United
States.
The primary function of DDX-DOASes is to provide conditioned
(cooled and dehumidified, or heated) outdoor air. In the cooling/
dehumidifying season, these units provide sensible cooling that reduces
the temperature of the outdoor air in addition to dehumidifying. DOE
noted in the July 2017 ASHRAE TP RFI that the ISMRE metric specified in
ANSI/AHRI 920-2015 does not include any provisions to measure the
sensible cooling contribution provided by the DDX-DOAS. 82 FR 34427,
34436 (July 25, 2017). For Standard Rating Conditions A and B in Table
2 and Table 3 of ANSI/AHRI 920-2015, conditioning the air to a space
temperature (70 [deg]F) requires sensible cooling as well as latent
cooling. In the July 2017 ASHRAE TP RFI, DOE requested comment on
whether the DDX-DOAS efficiency metric should account for this sensible
cooling. 82 FR 34427, 34436 (July 25, 2017).
In response to the July 2017 ASHRAE TP RFI, AHRI commented that
DDX-DOASes operate with a separate, sensible-cooling-only interior
cooling system, and that adding sensible cooling to the metric for DDX-
DOAS would skew efficiency values toward the non-primary function of
the DDX-DOAS. AHRI also stated that the capacity for sensible cooling
varies between DDX-DOAS designs, so the use of space-neutral air \18\
gives a worst-case efficiency to be used as comparison. (AHRI, No. 11
at p. 12) Carrier expressed concern that the current metric focuses on
latent capacity and that a shortcoming of the test procedure is that it
does not consider sensible capacity. Carrier also stated that
considering only latent capacity would be acceptable if the unit
delivers space-neutral air, but some DDX-DOASes can provide sensible
cooling. (Carrier, No. 6 at p. 3)
---------------------------------------------------------------------------
\18\ Space-neutral air, or neutral air, refers to air leaving an
air conditioner being at the target conditions for the occupied
space in the building (without the need for subsequent sensible or
latent cooling).
---------------------------------------------------------------------------
As discussed in section III.B.2.c of this NOPR, DOE proposes to
incorporate by reference the dehumidification metrics contained in the
updated version of the industry consensus standard, AHRI 920-2020. DOE
notes that the revised dehumidification metric in AHRI 920-2020,
ISMRE2, does not include provisions to determine the sensible cooling
contribution in the metric. However, as discussed in section III.B.1 of
this document, the ISMRE2 metric, which is specified in AHRI 920-2020
as the required rating metric for dehumidification efficiency, removes
the supplementary heat penalty to avoid penalizing DDX-DOAS units that
provide sensible cooling below 70 [deg]F.
DOE recognizes that the sensible cooling provided by a DDX-DOAS
unit may be valuable in many applications because it reduces the
cooling that must be provided by interior cooling systems, especially
at high outdoor temperatures. However, for certain applications it may
be important to reheat the supply air to balance the building's
sensible cooling load.\19\ DOE may consider in a future rulemaking
whether the efficiency metric should be revised to include sensible
cooling, if information is made available to support such a change.
---------------------------------------------------------------------------
\19\ As discussed in section III.B.1 of this document, AHRI 920-
2020 include separate application metrics (i.e., ISMRE270) to be
used for additional representations and that are calculated with a
supplementary heat penalty based on raising the supply air dry-bulb
temperature up to 70 [deg]F.
---------------------------------------------------------------------------
ASHRAE Standard 90.1-2016 uses ISMRE (using ANSI/AHRI 920-2015) as
the metric for the specified minimum efficiencies for DDX-DOAS. As
discussed in section III.B.1 of this NOPR, DOE is aware that updates to
the industry test procedure in AHRI 920-2020 using ISMRE2 could impact
the measured efficiencies of DDX-DOASes as compared to ISMRE measured
in accordance with ANSI/AHRI 920-2015, thereby necessitating use of an
appropriate crosswalk analysis. Therefore, DOE will address these
potential impacts on the measured efficiencies in a separate standards
rulemaking.
b. Heating Metric
ASHRAE 90.1-2016 adopted ISCOP, as presented in ANSI/AHRI 920-2015,
as the heating efficiency metric, and it also set minimum ISCOP
efficiency levels for both air-source and water-source heat pump DDX-
DOASes. ISCOP is a seasonal energy efficiency metric and is calculated
as the seasonal weighted average of heating COPs determined for two
heating Standard Rating Conditions specified in Table 2 and Table 3 of
ANSI/AHRI 920-2015.
In the July 2017 ASHRAE TP RFI, DOE noted that although the
Department has identified air-source heat pump DDX-DOASes available on
the market, section 3.9 of ANSI/AHRI 920-2015 defines ISCOP as an
energy efficiency metric only for water-source heat pump DDX-DOASes. 82
FR 34427, 34436 (July 25, 2017). DOE also noted
[[Page 36028]]
in the July 2017 ASHRAE TP RFI that equations in section 10.9 of ANSI/
ASHRAE 198-2013 for calculating the COP are labeled for application to
water-source heat pump DDX-DOASes, although DOE once again noted that
they could be applied to air-source heat pump DDX-DOASes. Id. As part
of the July 2017 ASHRAE TP RFI, DOE requested comment on the
calculation procedure for COP for air-source heat pumps, including
whether the equations in ANSI/ASHRAE 198-2013 are applicable to air-
source heat pumps. Id. DOE did not receive any comments on this topic.
Because ASHRAE Standard 90.1-2016 specifies minimum efficiency levels
for both air-source and water-source heat pump DDX-DOASes using ANSI/
AHRI 920-2015, DOE considers the ISCOP and COP calculations to be
applicable to the minimum efficiency levels in ASHRAE Standard 90.1-
2016 for both equipment classes.
In further clarification, AHRI 920-2020 revised the definition of
``Direct Expansion-Dedicated Outdoor Air System Units'' and the heating
efficiency metric (designated as ISCOP2) to include both air-source and
water-source heat pump DDX-DOASes. The ISCOP2 metric specified in
section 3.13 of AHRI 920-2020 also includes revisions to the outdoor
air conditions, weighting factors, and treatment of heating capacity
calculations. DOE is proposing to adopt ISCOP2 as the heating
efficiency metric for DDX-DOASes under the DOE test procedure,
expressed in Watts (W) of heating capacity per W of power input. As
discussed in section III.B.1 of this NOPR, updates to the industry
consensus test procedure in AHRI 920-2020 using ISCOP2 could impact the
measured heating efficiencies of DDX-DOASes as compared to ISCOP
measured in accordance with ANSI/AHRI 920-2015, thereby necessitating
use of an appropriate crosswalk analysis. Therefore, DOE will address
these potential impacts on the measured heating efficiencies in a
separate standards rulemaking.
ISCOP2 is calculated using COPISCOP values for Standard Rating
Conditions E and F that apply a supplementary heat penalty to the total
power input if the supply air dry-bulb temperature is less 70 [deg]F.
Section 6.11 of AHRI 920-2020 includes additional application rating
heating metrics, COPfull and COPDX-DOAS, for
additional representations. COPDX-DOAS is calculated without
a supplementary heat penalty, while COPfull is used for
manufacturer-specified outdoor conditions. DOE is proposing in section
2.2.2 of Appendix B to allow COPfull and
COPDX-DOAS to be used by manufacturers for voluntary
representations.
c. ISMRE2 and ISCOP2 Weighting Factors
As part of the July 2017 ASHRAE TP RFI, DOE requested information
about analysis of climate data relevant to the development of the ISMRE
and ISCOP test conditions and weighting factors. 82 FR 34427, 34436
(July 25, 2017). AHRI commented that the values and weightings for both
the dehumidification and heating points in ANSI/AHRI 920-2015 were
developed based on climatic data for a sample of twelve cities \20\
chosen to be representative of a wide range of climatic conditions in
the United States. According to AHRI, the climatic bin data were based
on 24-hour operation per day due to the variety of applications where
DDX-DOASes are installed and provide a reasonable standard for
assessing the part-load situations that will be encountered. (AHRI, No.
11 at p. 12) DOE notes that these test conditions in ANSI/AHRI 920-2015
were established to represent specific regions of the psychrometric
chart, as shown in the following Table III-2 and Table III-3.
---------------------------------------------------------------------------
\20\ The sample of 12 cities analyzed were: New York City,
Atlanta, Chicago, El Paso, Houston, Kansas City, Miami, Minneapolis,
Nashville, New Orleans, Norfolk, and Tucson.
---------------------------------------------------------------------------
In the development of AHRI 920-2020, DOE provided input on weather
data, and AHRI also reviewed Typical Meteorological Year (TMY) 2 \21\
weather data from the National Renewable Energy Laboratory. Based, in
part, on this input and data, AHRI 920-2020 specifies the ISMRE2 and
ISCOP2 test conditions and weighting factors, which represent the
number of hours per year for each test condition. Accordingly, Table
III-2 and Table III-3 also show the Standard Rating Conditions and
weighting factors included in sections 6.1, 6.12, and 6.13 of AHRI 920-
2020. DOE is proposing to adopt the weighting factors for the ISMRE2
(including the test conditions specific for ISMRE270) and
ISCOP2 metrics, as specified in AHRI 920-2020.
---------------------------------------------------------------------------
\21\ TMY stands for ``typical meteorological year'' and is a
widely used type of data available through the National Solar
Radiation Database. TMYs contain one year of hourly data that best
represents median weather conditions over a multiyear period. The
datasets have been updated occasionally, thus TMY, TMY2, and TMY3
data are available. See nsrdb.nrel.gov/about/tmy.html (last accessed
4/28/21).
Table III-2--ANSI/AHRI 920-2015 and AHRI 920-2020 Dehumidification Mode Standard Rating Conditions and ISMRE/
ISMRE2/ISMRE270 Weighting Factors
----------------------------------------------------------------------------------------------------------------
ANSI/AHRI 920-2015 AHRI 920-2020
--------------------------------------------------------------------
Standard rating Psychrometric chart Representative Representative ISMRE2 and
condition region represented condition (dry-bulb ISMRE condition (dry-bulb ISMRE270
temperature/ wet- weighting temperature/ wet- weighting
bulb temperature) factor bulb temperature) factor
----------------------------------------------------------------------------------------------------------------
A................ Above 55 [deg]F dew 95 [deg]F/78 [deg]F 12 95 [deg]F/78 [deg]F 14
point, Above 75 [deg]F
wet-bulb.
B................ Above 55 [deg]F dew 80 [deg]F/73 [deg]F 28 80 [deg]F/73 [deg]F 34
point, >69 [deg]F and
<=75 [deg]F wet-bulb.
C................ Above 55 [deg]F dew 68 [deg]F/66 [deg]F 36 70 [deg]F/66 [deg]F 39
point, >62 [deg]F and
<=69 [deg]F wet-bulb.
D................ Above 55 [deg]F dew 60 [deg]F/58 [deg]F 24 63 [deg]F/59 [deg]F 13
point, >56 [deg]F and
<=62 [deg]F wet-bulb.
----------------------------------------------------------------------------------------------------------------
[[Page 36029]]
Table III-3--ANSI/AHRI 920-2015 and AHRI 920-2020 Heating Mode Standard Rating Conditions and ISCOP/ISCOP2
Weighting Factors
----------------------------------------------------------------------------------------------------------------
ANSI/AHRI 920-2015 AHRI 920-2020
-------------------------------------------------------------------
Standard rating Psychrometric chart Representative Representative
condition region represented condition (dry-bulb ISCOP condition (dry-bulb ISCOP2
temperature/ wet- weighting temperature/ wet- weighting
bulb temperature) factor bulb temperature) factor
----------------------------------------------------------------------------------------------------------------
E................. Below 55 [deg]F dew 35 [deg]F/29 [deg]F 77 47 [deg]F/43 [deg]F 91
point, >23 [deg]F and
<=64 [deg]F dry-bulb.
F................. Below 55 [deg]F dew 16 [deg]F/12 [deg]F 23 17 [deg]F/15 [deg]F 9
point, <=23 [deg]F dry-
bulb.
----------------------------------------------------------------------------------------------------------------
3. Test Method
This section discusses the various issues that DOE identified in
the industry consensus test standards applicable to DDX-DOASes,
including those raised in the July 2017 ASHRAE TP RFI and considered as
part of DOE's review of AHRI 920-2020. These issues include: (1)
Definitions for certain terms used in the DDX-DOAS test procedure; (2)
optional break-in period for DDX-DOASes; (3) test facility,
instrumentation, and apparatus set-up issues; (4) DDX-DOAS unit set-up;
(5) test operating conditions; (6) requirements for water-cooled and
water-source heat pump DDX-DOASes; (7) defrost energy use; (8) test
methods for DDX-DOASes equipped with VERS; (9) tolerances; and (10)
secondary verification tests for dehumidification and heating tests.
Table 1 to 10 CFR 431.96 specifies the applicable industry test
procedure for each category of commercial package air conditioning and
heating equipment and specifies any additional testing requirements
that may also apply. In this NOPR, DOE is proposing to add test
procedure requirements for DDX-DOASes in a separate appendix in subpart
F to 10 CFR part 431 (i.e., proposed Appendix B). Accordingly, DOE
proposes to include DDX-DOASes in Table 1 to 10 CFR 431.96 and to
reference Appendix B for the DDX-DOASes test procedure.
a. Definitions
Section 3 of AHRI 920-2020 and section 3 of ANSI/ASHRAE 198-2013
define terms used in the industry consensus test standards for DDX-
DOASes. DOE reviewed these sections and is proposing generally to adopt
the definitions in section 3 of AHRI 920-2020 (as enumerated in section
2.2.1(a) of proposed Appendix B). As discussed, DOE is proposing
definitions in the test procedure provisions for ``direct expansion-
dedicated outdoor air system, or DX-DOAS'' as a category of commercial
package air conditioning and heating equipment, and ``dehumidifying
direct expansion-dedicated outdoor air system, or DDX-DOAS,'' as a
subset of DX-DOAS.
As discussed in the following paragraphs DOE is also proposing to
define ``integrated seasonal coefficient of performance 2, or ISCOP2,''
``integrated seasonal moisture removal efficiency 2, or ISMRE2,'' and
``ventilation energy recovery system, or VERS.'' In section 1.1 of
Appendix B, DOE proposes to provide that where any definitions conflict
between AHRI 920-2020 (or any of the industry standards referenced) and
the CFR, the CFR provisions control.
DOE notes that 10 CFR 431.92 includes definitions for the
efficiency metrics used for commercial package air conditioners and
heat pumps. Consistent with this approach, DOE is proposing definitions
at 10 CFR 431.92 for ``integrated seasonal coefficient of performance
2, or ISCOP2'' and ``integrated seasonal moisture removal efficiency 2,
or ISMRE2'' that are consistent with the definitions for these metrics
defined in sections 3.12 and 3.13 of AHRI 920-2020 and that
specifically reference the DDX-DOAS test procedure in proposed Appendix
B.
A ``ventilation energy recovery system'' (VERS) pre-conditions the
outdoor air before it enters the conditioning coil, thereby reducing
the cooling, dehumidification, or heating load on the refrigeration
system of the DDX-DOAS. ASHRAE Standard 90.1-2019 specifies separate
equipment classes and minimum efficiency levels for DDX-DOASes with
VERS equipment. DOE notes that neither a definition for a VERS nor a
different term for this system is included in the previous test
standards ANSI/AHRI 920-2015 and ANSI/ASHRAE 198-2013. However, AHRI
920-2020 does include a definition for VERS. DOE proposes, consistent
with AHRI 920-2020, to define a VERS as a system that preconditions
outdoor ventilation air entering the equipment through direct or
indirect thermal and/or moisture exchange with the exhaust air, which
is defined as the building air being exhausted to the outside from the
equipment.
A VERS may also be used by commercial air-conditioning equipment
other than DDX-DOASes. However, for commercial air-conditioning
equipment other than DDX-DOASes, neither ASHRAE Standard 90.1-2019 nor
the DOE energy conservation standards establish equipment classes based
on the presence of VERS. Under the DOE test procedures for commercial
package air conditioners and heat pump equipment other than DDX-DOASes,
VERS is a feature that is not installed for testing. Because an
understanding of VERS may be relevant to commercial package air
conditioners and heat pumps other than the proposed DDX-DOAS category
of equipment, DOE is proposing to establish a definition of VERS,
consistent with AHRI 920-2020, in 10 CFR 431.92 so that it is broadly
applicable when used in reference to both DDX-DOASes as well as other
commercial package air conditioning and heat pump equipment.
Additionally, DOE is proposing to amend the definition of
``commercial HVAC & WH product'' at 10 CFR 431.2 to explicitly include
DDX-DOAS.
Issue-5: DOE requests comment on the terminology DOE proposes to
use for DDX-DOASes, including ``integrated seasonal coefficient of
performance 2, or ISCOP2;'' ``integrated seasonal moisture removal
efficiency 2, or ISMRE2;'' and ``ventilation energy recovery system, or
VERS.''
In the July 2017 ASHRAE TP RFI, DOE sought clarification on the
difference between a reheat system and supplementary heat in ANSI/AHRI
920-2015 and ANSI/ASHRAE 198-2013. 82 FR 34427, 34436 (July 25, 2017).
The definition for supplementary heat provided in section 3.21 of ANSI/
AHRI 920-2015 does not state whether it includes heat provided by
reheat systems such as wrap-around heat pipes and wrap-around vapor
compression systems.
In response to the July 2017 ASHRAE TP RFI, AHRI suggested a
revised definition for ``supplementary heat'' that
[[Page 36030]]
excludes heat provided by the vapor compression cycle or a sub-system
that transfers heat from one part of the unit to another (e.g., wrap-
around heat pipe, wrap-around vapor compression system). (AHRI, No. 11
at p. 11)
DOE notes that section 3.25 of AHRI 920-2020 has clarified this
issue by defining ``supplementary heat'' to exclude a system that
transfers heat from the outdoor air to the supply air. The AHRI 920-
2020 definition distinguishes reheat provided by a vapor compression
cycle that is driving the dehumidification process from common
supplementary heat options such as fuel-fired heating, steam or hot
water heating coils, and electric resistance. Further, section 3.25 of
AHRI 920-2020 also states that reheat provided by secondary heat pumps,
wrap around heat pumps, or wrap around heat pipes are not considered as
supplementary heat. As discussed, DOE proposes to adopt the definition
for ``supplementary heat'' provided in section 3.25 of AHRI 920-2020,
as enumerated in section 2.2.1(a) of the proposed Appendix B, which
references section 3 of AHRI 920-2020.
b. Break-In Period
As part of the DOE test procedures for other commercial package air
conditioners and heat pumps, DOE provides the option for a ``break-in''
period, not to exceed 20 hours, with no ambient temperature
requirements, prior to performing a test. See 10 CFR 431.96(c). This is
intended to allow the unit to achieve optimal performance prior to the
test. Neither ANSI/AHRI 920-2015 nor ANSI/ASHRAE 198-2013 specify a
break-in period for testing DDX-DOASes. In response to the July 2017
ASHRAE TP RFI, AHRI commented that proper compressor break-in must be
allowed to provide a fair and accurate test. AHRI also stated that it
had previously submitted comments that 16 hours is not sufficient.
(AHRI, No. 11 at p. 20)
DOE addressed comments previously submitted by AHRI that DOE should
require a minimum 16-hour break-in period for all commercial air
conditioning equipment as part of the rulemaking finalized in a May 16,
2012 final rule for energy conservation standards and test procedures
for commercial heating, air-conditioning, and water-heating equipment.
77 FR 28928, 28943. As part of that final rule, DOE determined that
adopting a minimum break-in period of 16 hours would unnecessarily
increase testing costs for manufacturers of equipment that can achieve
stability in less than 16 hours. In recognition that different
equipment will require different amounts of break-in time to achieve
optimal performance and that break-in periods of longer than 16 hours
may be required for some equipment, DOE adopted an optional break-in
period up to a maximum period of 20 hours to allow the unit to achieve
optimal performance before testing for commercial air conditioning and
heating equipment. 77 FR 28928, 28943-28944 (May 16, 2012). Section 5.6
of AHRI 920-2020 incorporates the same break-in period provision, not
to exceed 20 hours. Therefore, DOE proposes to adopt the optional
break-in period up to a maximum of 20 hours for DDX-DOASes specified in
AHRI 920-2020 (section 5.6 Break-in), as enumerated in section 2.2.1(b)
of the proposed Appendix B, which references section 5 of AHRI 920-
2020.
c. Airflow-Measuring Apparatus
Figures 1 and 2 of ANSI/ASHRAE 198-2013 present the typical test
set-up for DDX-DOASes with and without energy recovery. The figures
show airflow and condition measuring apparatus at both the inlet and
the outlet ends of each airflow path (i.e., the outdoor/supply and
return/exhaust paths). DOE stated in the July 2017 ASHRAE TP RFI that
it is not clear whether airflow-measuring apparatus are required for
both entering and leaving air of each airflow path. 82 FR 34427, 34439
(July 25, 2017). DOE requested comment on whether it is beneficial or
necessary to use two airflow-measuring apparatus per airstream when
testing DDX-DOAS equipment. Id.
AHRI and Carrier both commented that using two airflow devices per
airstream would be difficult and costly due to challenges with space
constraints, additional physical barriers that can increase temperature
stratification in the test chamber, and issues associated with meeting
the specified design conditions due to fan reheat energy in the airflow
measuring stations. (AHRI, No. 11 at p. 19; Carrier, No. 6 at p. 7)
AHRI further commented that while additional airflow measuring stations
have the benefit of monitoring cross-leakage or general leakage in the
cabinet, it makes testing difficult, if not impossible, to perform.
(AHRI, No. 11 at p. 19) None of the commenters indicated that use of
two airflow-measuring apparatus per airflow path is necessary to obtain
accurate measurements.
Based on comments from AHRI and Carrier, DOE tentatively concludes
that requiring two airflow-measuring apparatus per airflow path may be
unduly burdensome for certain manufacturers. However, DOE also
recognizes that the additional measurements may provide an indication
of crossflow and/or leakage. DOE has tentatively concluded that AHRI
920-2020 offers a more suitable approach to airflow measurement, for
the reasons that follow. Section C2.2 of AHRI 920-2020 requires just
one airflow-measuring apparatus per airflow path. To provide a check
for general cabinet leakage, section C5.1 of AHRI 920-2020 specifies a
methodology for performing a secondary capacity measurement that does
not require a second airflow-measuring apparatus (rather, the
methodology for verifying dehumidification capacity is based on a
measurement of the weight of collected condensate). The requirement for
just one airflow-measuring apparatus per airflow path is consistent
with the DOE test procedures for all other commercial and residential
air-conditioning and heating systems and limits the testing costs and
burden on manufacturers.
Regarding the commenters' concern that the fan heat of the airflow-
measuring apparatus might affect the controlled air conditions, DOE
recognizes that this could affect the temperature of the return air
entering the DDX-DOAS under test. A similar issue could occur when
duct-inlet booster fans are used for moving outdoor air either to the
outdoor ventilation air inlet from a separate room, or when moving
desiccant regeneration air from another room. On this topic, section
C3.2.2 of AHRI 920-2020 specifies that in such circumstances, the air
conditions are to be measured downstream of the fan and that the
sampled air used for the air condition measurement be returned: (a) To
a location between the flow nozzles and the fan of a return airflow-
measuring apparatus, or (b) to the separate room from which air is
drawn when a boost fan is used in the inlet duct. Accordingly, in this
NOPR, DOE is proposing to adopt the provisions for the airflow-
measuring apparatus specified in AHRI 920-2020 section C2.2, ``Use of a
Single Airflow Rate Measuring Apparatus per Airflow Path'' in Appendix
C of AHRI 920-2020 (rather than the dual measurement apparatus
specifications in Figures 1 and 2 of ANSI/ASHRAE 198-2013), as
enumerated in section 2.2.1(f) of the proposed Appendix B, which
references Appendix C of AHRI 920-2020.
d. Test Operating Conditions
Through incorporation by reference of AHRI 920-2020, DOE is
proposing to adopt the test operating conditions
[[Page 36031]]
specified in AHRI 920-2020 for DDX-DOAS units. These include: (1)
Standard Rating Conditions (Tables 4 and 5 of section 6 of AHRI 920-
2020, as enumerated in section 2.2.1(c) of the proposed Appendix B,
which references section 6 of AHRI 920-2020 omitting sections 6.1.2 and
6.6.1); (2) simulated ventilation air conditions for testing under
Option 2 for DDX-DOASes with VERS (section 5 of AHRI 920-2020 (which
includes section 5.4.1.2 Option 2), as enumerated in section 2.2.1(b)
of the proposed Appendix B, which references section 5 of AHRI 920-
2020); (3) atmospheric pressure (section 5 of AHRI 920-2020 (which
includes section 5.10 Atmospheric Pressure), as enumerated in section
2.2.1(b) of the proposed Appendix B); (4) target supply air conditions
(section 6 of AHRI 920-2020 (which includes section 6.1.3 Supply Air
Dewpoint Temperature and section 6.1.4 Supply Air Dry Bulb
Temperature), as enumerated in section 2.2.1(c) of the proposed
Appendix B); (5) external static pressure (section 6 of AHRI 920-2020
(which includes section 6.1.5.6 External Static Pressure), as
enumerated in section 2.2.1(c) of the proposed Appendix B); and (6)
target supply and return airflow rates (section 6 of AHRI 920-2020
(which includes section 6.1.5 Supply and Return Airflow Rates), as
enumerated in section 2.2.1(c) of the proposed Appendix B).
DOE received comments from interested parties regarding target
supply and return airflow rates and target supply air conditions in
response to the July 2017 ASHRAE TP RFI, and the following section
discusses these specific issues.
i. Target Supply and Return Airflow Rates
Section 5.2.2 of ANSI/AHRI 920-2015 and section 8.1 of ANSI/ASHRAE
198-2013 require the supply airflow rate to be set in accordance with
manufacturer specifications. In the July 2017 ASHRAE TP RFI, DOE
observed that many DDX-DOAS models are capable of operating over a
range of airflow rates. 82 FR 34427, 34437 (July 25, 2017). DOE expects
these models to have supply air fans that can be configured with a
range of speeds to accommodate the airflow range and the variation in
duct length in field installations. Id. The performance of these models
may also vary significantly from the low end to the high end of the
specified airflow range. As part of the July 2017 ASHRAE TP RFI, DOE
sought comments on how manufacturers select the airflow rate for
testing, given the large range of airflows that are typical of DDX-DOAS
units. Id.
In response to this issue, AHRI commented that the optimum-
efficiency airflow varies with each application and that the
manufacturer should specify the design airflow rate as long as it
achieves the 55 [deg]F dew point temperature. (AHRI, No. 11 at pp. 13-
14) The approach described by AHRI is consistent with the approach of
AHRI 920-2020, which stipulates the use of the manufacturer-specified
airflow in section 6.1.5 of that document. This section of AHRI 920-
2020 also addresses how to set the airflow when it is not specified by
the manufacturer and the case where the dehumidification provided is
not consistent with DDX-DOAS performance (i.e., provision of supply air
at 55 [deg]F or lower dew point, when using the manufacturer-specified
airflow).\22\
---------------------------------------------------------------------------
\22\ Section 6.1.3 of AHRI 920-2020 includes an adjustment for
maximum supply air dew point temperature to increase linearly as
barometric pressure decreases, up to 57.3 [deg]F at the minimum-
allowed 13.7 psia test pressure.
---------------------------------------------------------------------------
As discussed, DOE is proposing to adopt the provisions in section
6.1.3 and 6.1.5 of AHRI 920-2020, which specify that the target supply
airflow rate be the manufacturer-specified airflow rate and that, for
Standard Rating Condition A, achieves dehumidification consistent with
providing a 55 [deg]F dew point temperature in standard atmospheric
pressure conditions. In cases where supply airflow is not specified by
the manufacturer, or supply air dew point exceeds the maximum when
using the manufacturer-specified airflow, AHRI 920-2020 requires
setting airflow for Standard Rating Condition A such that the supply
air dew point does not exceed the maximum.
ii. Units With Cycle Reheat Functions
As part of the July 2017 RFI, DOE noted that provisions regarding
reheat and the supplementary heat penalty specified in ANSI/AHRI 920-
2015 and ANSI/ASHRAE 198-2013 were unclear. 82 FR 34427, 34436 (July
25, 2017). Most of the DDX-DOAS models that are equipped with the
capability to reheat dehumidified air to space-neutral conditions use
hot refrigerant gas discharged by the compressor to reheat the
dehumidified air leaving the evaporator coil. Other approaches can also
be used to transfer heat from one part of the DDX-DOAS to another.
(Section 3.21.1 of AHRI 920-2020 defines all of these methods as
``cycle reheat.'') Reheat may also be provided by supplementary heat
sources, such as a gas furnace or an electric resistance heater, but
these are not considered cycle reheat. A discussion of cycle reheat
capability with respect to the scope of this test procedure is provided
in section III.A.4 of this document, and a discussion of the
supplementary heat penalty is provided in section III.B.3.a of this
document.
ANSI/AHRI 920-2015 requires that supply air dew point temperature
be 55 [deg]F or lower, which generally means (i.e., for a DDX-DOAS that
removes moisture by latent cooling without the use of desiccants) that
the air must be cooled to a temperature that is, at most, a few degrees
above 55 [deg]F. Section 6 of ANSI/AHRI 920-2015 does not explicitly
require testing with reheat turned on, but note 3 to Table 2 and note 3
to Table 3 of that industry standard require the DDX-DOAS to condition
supply air to a minimum dry-bulb temperature of 70 [deg]F for all
dehumidification and heating tests--and this would have to be
accomplished with active reheat (as discussed in the following
paragraphs). Further, for units unable to meet this minimum threshold,
section 6.1.3.1 of ANSI/AHRI 920-2015 specifies the application of a
supplementary heat penalty to represent the power input that would be
required to heat the supply air to the 70 [deg]F target using electric
resistance heating.
DOE noted in the July 2017 RFI that ANSI/ASHRAE 198-2013 includes
two dehumidification tests, one with cycle reheat functions turned on
and the other with cycle reheat functions turned off (sections 8.3.1.1
and 8.3.1.2, respectively). DOE further noted that ANSI/AHRI 920-2015
does not, however, specify which of these values is used in the
calculation of ISMRE. 82 FR 34427, 34436 (July 25, 2017).
As part of the July 2017 ASHRAE TP RFI, DOE requested comment on
whether the dehumidification test with cycle reheat on or off should be
used to calculate ISMRE, and how and when the supplementary heat
penalty is applied. 82 FR 34427, 34436 (July 25, 2017). AHRI commented
that the dehumidification efficiency metrics specified in ANSI/AHRI
920-2015 are based on supply air at a dry-bulb temperature of 70
[deg]F, and if the unit requires reheat to be on (as described in ANSI/
ASHRAE 198-2013) for supply air temperature control, then this reheat-
on test is needed to determine dehumidification capacity and
efficiency. (AHRI, No. 11 at p. 11) DOE understands AHRI's comment to
mean that ANSI/AHRI 920-2015 effectively requires cycle reheat to be
activated during dehumidification tests in order to meet both the
supply air dew point and dry-bulb temperature requirements.
In contrast to ANSI/AHRI 920-2015, AHRI 920-2020 more explicitly
[[Page 36032]]
addresses the use of cycle reheat for dehumidification tests and
provides more information on when the supplementary heat penalty should
be used. As discussed in section III.B.2.a of this NOPR, DOE is
proposing to adopt the revised MRE and ISMRE2 metrics specified in AHRI
920-2020, which do not include a supplementary heat penalty. Section
6.1.4.2 of AHRI 920-2020 specifies that when determining MRE and
ISMRE2, the manufacturer shall specify whether cycle reheat is to be
activated for the test. As discussed in section III.B.2.a of this
document, AHRI 920-2020 provides separate application metrics (i.e.,
MRE70 and ISMRE270) which may be used for
representations and which require a supply air dry-bulb temperature
above 70 [deg]F (and below 75 [deg]F). For these separate application
metrics, if cycle reheat cannot achieve 70 [deg]F, a supplementary heat
penalty is applied based on raising the supply air dry-bulb temperature
up to 70 [deg]F (see section 6.1.4.1 of AHRI 920-2020). DOE has
tentatively determined that these provisions in AHRI 920-2020 clarify
the requirements for cycle reheat and the supplementary heat penalty,
so the Department is proposing to adopt these provisions in this NOPR
(section 6 of AHRI 920-2020, as enumerated in section 2.2.1(c) of the
proposed Appendix B).
iii. Target Supply Air Dry-Bulb Temperature
As discussed, in the July 2017 ASHRAE TP RFI, DOE noted that ANSI/
AHRI 920-2015 includes a requirement of minimum supply air temperature
of 70.0 [deg]F for all Standard Rating Conditions and a maximum dew-
point temperature of 55.0 [deg]F for Standard Rating Conditions for
dehumidification. In that document, DOE further noted that ANSI/ASHRAE
198-2013 requires a supply air temperature of 75.2 [deg]F or as close
to this value as the controls will allow during testing. As part of the
July 2017 ASHRAE TP RFI, DOE requested comment on the difference in
target supply air temperature requirements between ANSI/AHRI 920-2015
and ANSI/ASHRAE 198-2013, and the appropriate supply air temperature
for use in the DOE test procedure for DDX-DOASes. 82 FR 34427, 34438
(July 25, 2017).
AHRI and Goodman commented that the minimum supply air temperature
should be 70 [deg]F. AHRI added that ANSI/ASHRAE 198-2013, which was
developed based on previous versions of AHRI 920 that required a supply
air temperature of 75 [deg]F, is being updated to reflect the new value
of 70 [deg]F. (AHRI, No. 11 at p. 17; Goodman, No. 14 at p. 2)
As discussed in the previous subsection, DOE proposes to
incorporate by reference the provisions in section 6.1.4 of AHRI 920-
2020, which specifies setting the supply air dry-bulb temperature to
within a range of 70-75 [deg]F for tests to determine dehumidification
metrics. For all dehumidification tests, 75 [deg]F represents the
maximum supply air dry-bulb temperature above which a supplementary
cooling penalty must be applied. As noted in section III.B.3.d.ii of
this NOPR, a supplementary heat penalty must be applied for ISCOP2
calculations when the minimum supply air dry-bulb temperature of 70
[deg]F cannot be met in heating mode.
iv. Target Supply Air Dew-Point Temperature
Note 5 to Table 2 and note 6 to Table 3 in ANSI/AHRI 920-2015 state
that the maximum dew point for Standard Rating Conditions A through D
shall be 55.0 [deg]F. The industry consensus standard does not specify
whether these conditions apply to the outdoor air, supply air, or
return air. DOE interprets these requirements to apply to the supply
air because the humidity levels for outdoor air and return air are
already specified in the same tables.
Furthermore, although ANSI/AHRI 920-2015 specifies a maximum dew
point temperature, the industry test standard does not include
requirements to ensure that the dew-point temperature is maintained at
the same level while testing at the different Standard Rating
Conditions specified in ANSI/AHRI 920-2015. Many DDX-DOASes are
equipped with modulating/variable capacity compressors, thereby
allowing control for a given supply air dew point temperature. Allowing
a lower dew point temperature for Standard Rating Conditions B, C, and
D specified in ANSI/AHRI 920-2015 could give a better MRE rating for
those test points, but the unit would use more energy to the extent it
provides unnecessary excess dehumidification if operated in that
manner. DOE also recognizes that the conditioned space latent cooling
requirements for Standard Rating Condition A specified in ANSI/AHRI
920-2015 represent the worst-case scenario, so there would be no need
to deliver a lower dew point (i.e., excess dehumidification) for
Standard Rating Conditions B, C, and D. AHRI 920-2020 revises the
supply air dew point requirements. Section 6.1.3 of AHRI 920-2020
requires that the average supply air dew point for Standard Rating
Condition B, C, and D must be within 0.3 [deg]F of the Standard Rating
Condition A dew point value.
Accordingly, in this NOPR, DOE proposes to adopt the relevant
provisions found in section 6.1.3 in AHRI 920-2020, which explicitly
state that the supply air dew point temperature shall be 55.0 [deg]F or
below for all Standard Rating Conditions A through D when operated at a
barometric pressure of 29.92 in Hg, and that the supply air dew point
temperature for Standard Rating Conditions B, C, and D must be within
0.3 [deg]F of the measured supply air dew point temperature for
Standard Rating Condition A, as noted above.
v. Units With Staged Capacity Control
During testing, DDX-DOAS units with modulating compressors may be
able to achieve supply air conditions within the proposed tolerances of
the target conditions for Standard Rating Conditions B, C, and D.
However, units with staged capacity will not likely be able to do this
because they control capacity in larger increments. DDX-DOAS units with
staged capacity or reheat control unable to maintain stable operation
at the proposed dry-bulb and dew-point temperature targets within
proposed tolerances would have to cycle between two stages (or cycle
between the compressor(s) being on and off) to deliver average
conditioning consistent with the target.
Neither ANSI/AHRI 920-2015 nor ANSI/ASHRAE 198-2013 have provisions
to address units that cycle. In response to the July 2017 ASHRAE TP
RFI, AHRI commented that the time average testing method suggested by
DOE in its initial review section 6.6 of ANSI/AHRI 920-2015 would
prevent credit for over-dehumidifying at Standard Rating Conditions B,
C, and D, but is excessively complex. Instead, AHRI recommended a
calculated adjustment that does not credit moisture removal in excess
of the Standard Rating Condition A design dew-point temperature. (AHRI,
No. 11 at p. 20)
This issue has now largely been addressed in AHRI 920-2020.
Specifically, section 6 of AHRI 920-2020 prescribes a method to address
DDX-DOASes with staged capacity control that is consistent with the
aforementioned method of DOE's initial review. It differs from DOE's
suggested method in that it applies the weighted averaging on the basis
of the supply air humidity ratio rather than the dew point, and that it
applies any applicable supplementary cooling or heat penalty to
operation at each particular stage rather than after determination of a
weighted average supply air dry-bulb
[[Page 36033]]
temperature. Given the development of defined test requirements and
equations addressing over-dehumidification, DOE initially concludes
that the method in AHRI 920-2020 is not excessively complex. AHRI 920-
2020 requires that when testing DDX-DOASes with staged capacity control
in a dehumidification test condition having a supply condition dew
point target (e.g., Conditions B, C, or D), if the dew point
temperature cannot be controlled within the specified test tolerances
for a given part-load condition, a weighted average of the results of
two tests that bracket the target dew point temperature will be used.
In this NOPR, DOE is proposing to adopt the provisions in section 6 of
AHRI 920-2020 for achieving the target supply air conditions for units
with staged capacity control.
Staging of compressor capacity may also affect operation in heating
mode. Section 6 of AHRI 920-2020 prescribes methods for determining COP
to account for cycling between compressor stages, or for operation when
the lowest-capacity compressor stage provides more capacity than
required to heat the supply air to 75 [deg]F. These methods are similar
to the AHRI 920-2020 method for addressing staged compressor capacity
for dehumidification. Accordingly, DOE proposes to adopt the provisions
in AHRI 920-2020 for staged capacity heat pump DDX-DOASes in heating
mode.
e. Water-Cooled and Water-Source Heat Pump DX-DOAS Equipment
i. Test Conditions for Multiple-Inlet Water Sources
As discussed in the July 2017 ASHRAE TP RFI, the inlet water
temperatures in ANSI/AHRI 920-2015 Table 2 for testing water-cooled
DDX-DOASes differ from the water-source heat pump inlet temperature
conditions specified in Table 3 for water-source heat pump DDX-DOASes
tested using the ``water source'' test conditions. DOE requested
comment on the need for different dehumidification test conditions for
a water-cooled DDX-DOAS as compared to a water-source heat pump DDX-
DOAS using the closed water loop test conditions. 82 FR 34427, 34438
(July 25, 2017). In the July 2017 ASHRAE TP RFI, DOE also pointed out
that Tables 2 and 3 in ANSI/AHRI 920-2015 include two application
configurations \23\ for water-cooled DDX-DOASes and three application
configurations for water-source heat pump DDX-DOASes. Id. DOE notes
that ASHRAE 90.1-2016 established different standards for each of these
five application configurations.
---------------------------------------------------------------------------
\23\ In the context of ANSI/AHRI 920-2015, an application
configuration specifies test conditions based on the expected
application of the DDX-DOAS.
---------------------------------------------------------------------------
In response to the July 2017 ASHRAE TP RFI on this issue, AHRI
commented that the two sets of water temperatures for water-cooled DDX-
DOASes and water-source heat pump DDX-DOASes should be identical and
that the differences would be resolved in an update to ANSI/AHRI 920-
2015. (AHRI, No. 11 at p. 17) AHRI also commented that in almost all
cases, a single design is used for water-cooled equipment used with
cooling tower water and chilled water, and, similarly, a single design
is used for all of the water-source applications, adding that for each
of these cases, a single set of water conditions can be used for
testing. AHRI recommended that the various entering water and inlet
fluid conditions remain as presented in the ANSI/AHRI 920-2015
standard, but any regulated products are to be tested to the ``Chilled
Water Entering Condenser Temperature'' column values in Table 2 and the
``Water Source Heat Pumps'' column values in Table 3. (AHRI, No. 11 at
p. 17)
In response, DOE notes that AHRI 920-2020 still provides separate
inlet fluid rating conditions for the different water-cooled and water-
source heat pump DDX-DOAS applications but now identifies some as
optional application rating conditions. In light of the retention of
these separate inlet fluid rating conditions in AHRI 920-2020, DOE
surmises that AHRI's and industry's original position on these
conditions, as set forth in the comments in response to the July 2017
ASHRAE TP RFI, changed during the course of developing that industry
consensus standard. Table 4 of AHRI 920-2020 continues to include
separate inlet fluid rating conditions for water-cooled cooling tower
and water-cooled chilled water DDX-DOASes, but Note 3 to Table 4 of
AHRI 920-2020 indicates that the water-cooled chilled water condition
is the optional application rating condition, contrary to AHRI's
recommendation in response to the July 2017 ASHRAE TP RFI. Table 5 of
AHRI 920-2020 includes separate inlet fluid rating conditions for
water-source and ground-source closed-loop heat pump DDX-DOASes but
identifies the ground-source closed-loop conditions as the optional
application rating condition. Tables 4 and 5 of AHRI 920-2020 also
revise the inlet temperatures of the rating conditions for water-cooled
cooling tower, water-source heat pump, and water-source ground-source
closed-loop heat pump DDX-DOASes. In this NOPR, DOE is proposing to
adopt the water/fluid rating conditions provided in AHRI 920-2020
(section 6 of AHRI 920-2020, which includes Table 4 and Table 5, as
enumerated in section 2.2.1(c) and 2.2.2 of the proposed Appendix B),
including the chilled water and ground-source closed-loop conditions
specified as optional in AHRI 920-2020 so as to allow for voluntary
representations for those applications. In any future energy
conservation standards rulemaking for DDX-DOASes, DOE would consider
establishing standards and the corresponding certification requirements
in the context of the inlet fluid temperature conditions specific for
water-cooled cooling towers and for water-source heat pumps provided in
Table 4 and Table 5 of AHRI 920-2020, respectively.
ii. Condenser Liquid Flow Rate
In the July 2017 ASHRAE TP RFI, DOE noted that ANSI/AHRI 920-2015
provides instructions for setting the condenser liquid flow rate in
section 6.1.4 and condenser liquid entering temperature in Tables 2 and
3 when conducting the dehumidification test for water-cooled and water-
source heat pump DDX-DOASes. 82 FR 34427, 34437 (July 25, 2017).
Section 6.1.4 of ANSI/AHRI 920-2015 indicates to use the liquid flow
rates ``specified by the manufacturer.'' The manufacturer must specify
a single liquid flow rate for tests at all Standard Rating Conditions
as defined in ANSI/AHRI 920-2015, unless the unit is equipped with
automatic control of the liquid flow rate.
In the July 2017 ASHRAE TP RFI, DOE noted that ANSI/AHRI 340/360-
2007 and ANSI/AHRI 210/240-2008, which are incorporated by reference as
DOE's test procedures for rating water-cooled commercial air-
conditioning equipment, specify inlet and outlet water temperature
requirements rather than relying on manufacturers to determine water
flow rate. Further, both of these industry consensus standards specify
that the full-load water flow rate determined for the Standard Rating
Conditions should also be used for part-load rating conditions. DOE
further stated in the July 2017 ASHRAE TP RFI that these test methods
reflect the typical design temperature differential for cooling towers
serving water-cooled equipment, and they are very common for control of
condenser water pumps; hence, it is not clear to DOE why the same test
method would not be adopted for water-cooled DDX-DOAS. 82 FR 34427,
34437 (July 25 2017). As part of the July 2017 ASHRAE TP RFI, DOE
requested information on how
[[Page 36034]]
condenser water flow rates are set in the field, how they are
controlled at part-load, and whether the relevant provisions in ANSI/
AHRI 920-2015 provide sufficient guidance regarding how to set up water
flow for DDX-DOASes with automatic water flow control systems. Id.
AHRI and Carrier commented that the condenser water flow rates
should be set by the manufacturer or the installation instructions,
consistent with ANSI/AHRI 920-2015. (AHRI, No. 11 at p. 15; Carrier,
No. 6 at p. 5) Carrier added that for part-load conditions, setting the
condenser water flow rate will depend on what is needed for head
pressure control, and that this should be defined in the installation
instructions and followed for the test. Carrier stated that some
equipment may require no control and that others may use head pressure
flow regulating valves. (Carrier, No. 6 at p. 5) AHRI argued that any
variation in flow rate that occurs automatically based on the operation
and the equipment design will be measured during testing, with the
pressure drop at that flow rate also being measured. AHRI indicated
that the pumping penalty accounts for different manufacturer
specifications of flow rates and pressure drop at each of the test
conditions. (AHRI, No. 11 at p. 15)
As part of its update to the industry consensus test standard for
DDX-DOASes, AHRI added additional requirements for liquid flow rate.
More specifically, while section 6.1.6.1 of AHRI 920-2020 continues to
provide that the water flow rate be specified by the manufacturer, the
test method now adds that it must deliver a liquid temperature rise no
less than 8 [deg]F when testing under Standard Rating Condition A.
Section 6.1.6.2 of AHRI 920-2020 requires that the flow rate set under
Standard Rating Condition A be used for testing at the remaining
Standard Rating Conditions (B through F), unless automatic adjustment
of the liquid flow rate is provided by the equipment. Section 6.1.6.2
of AHRI 920-2020 also requires that if condenser water flow rate is
modulated under part-load conditions, the flow rate must not exceed the
flow rate set for Condition A.
DOE has tentatively concluded that the addition of a minimum
temperature differential in AHRI 920-2020 better reflects control
strategies for cooling towers serving water-cooled equipment and for
condenser water pumps while still leaving flexibility for manufacturers
to specify full-load flow rate and to implement options for modulating
flow rate at part-load conditions. The Department notes that the
provision allowing for automatic adjustment of the liquid flow rate for
part-load tests accounts for manufacturer control strategies, such as
condenser head pressure control, and is also accounted for in the water
pump effect (discussed in the following section). DOE has tentatively
concluded that these provisions would be representative of flow rates
during an average use cycle and would not be unduly burdensome to
conduct. Therefore, DOE is proposing to adopt the liquid flow
requirements in AHRI 920-2020 for water-cooled and water-source heat
pump DDX-DOASes (section 6 of AHRI 920-2020, which includes section
6.1.6 Liquid Flow Rates for Water-Cooled, Water-Source Heat Pump, and
Ground-Source Heat Pump), as enumerated in section 2.2.1(c) of the
proposed Appendix B.
iii. Water Pump Effect
As part of the July 2017 ASHRAE TP RFI, DOE noted that ANSI/AHRI
920-2015 includes an equation for calculating the ``water pump
effect,'' which is an estimate of the energy consumption of non-
integral water pumps (i.e., pumps that are not part of the DDX-DOAS
unit and whose power consumption would, therefore, not already be part
of the measured power). 82 FR 34427, 34438 (July 25 2017). DOE noted
that section 6.1.3 of ANSI/AHRI 920-2015 implies that this calculation
applies solely to water pumps serving refrigerant-to-liquid heat
recovery devices--no indication is given whether the equation also
applies for pumps serving water-source or water-cooled condensers--
although it is possible that the term ``refrigerant-to-liquid heat
recovery device'' refers to the condenser of a water-source heat pump
DDX-DOAS. Id.
In the July 2017 ASHRAE TP RFI, DOE requested confirmation that the
``refrigerant-to-liquid heat recovery device'' cited in section 6.1.3
of ANSI/AHRI 920-2015 is intended to include heat exchangers used for
heat rejection during the dehumidification cycle, and comment on
whether Equation 1 of this section for estimating the energy use of
water pumps is appropriate for DDX-DOASes with water-cooled condensers.
Id. In its comments, AHRI confirmed that the term ``refrigerant-to-
liquid heat recovery device'' is intended to include liquid-to-
refrigerant heat exchangers used in the dehumidification cycle and
heating cycle. (AHRI, No. 11 at p. 16)
The revisions to the industry consensus testing standard in AHRI
920-2020 clarify this matter and are consistent with the public
comments received. Section 6.1.6.4 of AHRI 920-2020 provides the water
pump effect equation, and section 11.1 of AHRI 920-2020 states within
the definition of symbol PE,x that the water pump effect
applies to all water-cooled and water-source units without integral
water pumps. Thus, DOE is proposing to adopt the water pump effect
provisions in sections 6.1.6.4 and 11.1 of AHRI 920-2020 to account for
the energy use of water pumps for water-cooled condensers, as
enumerated in section 2.2.1(c) and section 2.2.1(d) of the proposed
Appendix B, which reference sections 6 and 11 of AHRI 920-2020,
respectively.
In further clarification, the total pump effect does not need to be
calculated for pumps that are integral to the DDX-DOAS, because the
power for these pumps would be measured as part of the main DDX-DOAS
power measurement. Currently, the number of DDX-DOAS models on the
market with integral pumps is very limited. However, AHRI 920-2020 does
not explicitly state the amount of external head pressure \24\ to use
when testing DDX-DOASes with integral pumps, a necessary parameter. DOE
notes that the calculation of the water pump effect for DDX-DOASes
without integral pumps specified AHRI 920-2020 includes a fixed adder
of 25 Watts per gallon per minute based on 20 feet of water column of
external head pressure, a value which the Department reasons could be
suitably applied to DDX-DOASes with integral pumps. Accordingly, DOE is
proposing to include additional specifications in section 2.2.1(c)(ii)
of proposed Appendix B that DDX-DOASes with integral pumps be
configured with an external head pressure equal to 20 feet of water
column (i.e., the same level of external head pressure used in the
calculation of the pump effect for DDX-DOASes without integral pumps).
---------------------------------------------------------------------------
\24\ ``External head pressure'' reflects the pump power output,
in that it represents the height to which the pump can raise the
water if the water were being moved opposite the force of gravity.
---------------------------------------------------------------------------
DOE has initially determined that the proposal to specify the same
external head pressure for integral pumps as the external head pressure
used in the calculation of the pump effect for DDX-DOASes without
integral pumps is consistent with the industry consensus test
procedure. The proposed requirement would provide additional direction
for treatment of integral pumps consistent with the treatment of non-
integral pumps and would provide for the representative comparability
of results between DDX-DOASes with and without integral pumps. To the
extent the industry test procedure does not specify an external head
pressure for DDX-DOASes with an integral pump,
[[Page 36035]]
the industry test procedure would not ensure that measured results are
comparative, and due to the potential variation resulting from the
absence of the specification, the industry test procedure would not
ensure that the results reflect the equipment's representative average
energy efficiency or energy use. As such, DOE has initially determined,
supported by clear and convincing evidence, that in the absence of a
specification for the external head pressure for an integrated pump,
the industry test procedure would not meet the statutory requirements
of 42 U.S.C. 6314(a)(2)-(3) and is, therefore, proposing the
supplemental specification.
In addition, DOE is proposing a condition tolerance of up to 1 foot
of water column greater than the 20-foot requirement (which equates to
5 percent), which is equivalent to the condition tolerance on air side
external static pressure in Table 9 of AHRI 920-2020 (Test Operating
and Test Condition Tolerances); namely, the provision in that table
provides for up to 0.05 inch of water column greater than the target
external static pressure, which is around 1 inch of water column.
Similarly, DOE is proposing an operating tolerance of up to 1 foot of
water column, which is equivalent to the operating tolerance on air
side external static pressure in Table 9 of AHRI 920-2020; namely, the
provision in that table provides for 0.05 inch of water column. To the
extent the industry test procedure does not specify a condition
tolerance and operating tolerance for the water column, the industry
test procedure would not ensure consistent and comparable results and
would not ensure that the results reflect the equipment's
representative average energy efficiency or energy use. As such, DOE
has initially determined, supported by clear and convincing evidence,
in the that absence of such tolerances for the water column, the
industry test procedure would not meet the statutory requirements of 42
U.S.C. 6314(a)(2)-(3) and is, therefore, proposing the supplemental
specification.
Issue-6: DOE requests comment on the proposal to require that
water-cooled and water-source DDX-DOASes with integral pumps be set up
with an external pressure rise equal to 20 feet of water column with a
condition tolerance of -0/+1 foot and an operating tolerance of 1 foot.
iv. Energy Consumption of Heat Rejection Fans and Chillers
Neither ANSI/AHRI 920-2015 nor ANSI/ASHRAE 198-2013 address
accounting for the energy consumption of heat rejection fans (e.g.,
cooling tower fans) for water loops serving the condensers of water-
cooled DDX-DOASes. 82 FR 34427, 34438 (July 25, 2017). DOE noted that
section 6.1 of AHRI 340/360-2007, which is used for rating certain
water-cooled commercial package air conditioning and heat pump
equipment, provides a power consumption adjustment for both the cooling
tower fan and the circulating water pump (it is assumed that the pump
is external to the air conditioning equipment). Id. In addition,
neither ANSI/AHRI 920-2015 nor ANSI/ASHRAE 198-2013 address accounting
for the energy consumption of chiller systems used to provide chilled
water to DDX-DOASes with chilled-water-cooled condensers. In the July
2017 ASHRAE TP RFI, DOE requested comment on accounting for the energy
consumption for heat-rejection fans and chiller systems employed in
water-cooled or water-loop DDX-DOASes. Id.
AHRI commented that the AHRI test standard for certain commercial
package air conditioning and heat pump equipment includes the cooling
tower fan and pump energy as part of a flat rate adjustment, but that
the International Organization for Standardization (ISO) test standard
for water-source heat pumps does not account for cooling tower fan
energy use at this time. AHRI stated that the minimum efficiency values
for DDX-DOASes specified in ASHRAE 90.1-2016 were based on the current
ANSI/AHRI 920-2015 standard that does not account for the energy
consumption of heat-rejection fans or the chiller system, although it
does account for the additional water pumping energy (see the
discussion of the water pump effect in section III.B.3.e.iii of this
document). AHRI stated that, as a result, DOE should not account for
this energy in the efficiency metric for DDX-DOASes because doing so
introduces unknown impacts on the design and costs associated with
meeting the minimum efficiency requirements. (AHRI, No. 11 at pp. 16-
17) Carrier also commented that heat-rejection fans are not part of a
water-cooled unit but are part of the cooling tower rating and are
covered by Table 6.8.1.7 in ASHRAE 90.1-2016. (Carrier, No. 6 at p. 5)
Carrier commented that chiller system energy use should not be included
in the efficiency metric because this is not a system rating and is
only a component rating method for the DDX-DOAS itself. (Carrier, No. 6
at p. 6)
The revised AHRI 920-2020 also does not include energy use of the
heat-rejection fans and chiller systems employed in water-cooled or
water-loop DDX-DOASes. DOE observes that accounting for this energy use
is not a consistent industry practice, as evidenced by the differences
between the AHRI 340/360-2007 approach for more typical commercial
package air conditioning equipment and the ISO approach for water-
source heat pumps. The heat rejection fan addition for more typical
water-cooled commercial package air conditioning equipment is a modest
energy adder (around 10 percent of unit power).\25\ Furthermore,
including the energy of the heat rejection fan and chiller systems
would not help to distinguish between models of different efficiency,
since the adder would be identical for two same-capacity models with
different efficiencies. For these reasons, and consistent with AHRI
920-2020, DOE is not proposing in this NOPR to include any energy
consumption associated with heat rejection fans, cooling towers, or
chiller systems used to cool the water loops of water-cooled or water-
source DDX-DOASes.
---------------------------------------------------------------------------
\25\ For example, for a minimally-compliant 120,000 Btu/h water-
cooled unit with gas heat having a 12.5 EER (see 10 CFR 431.97 Table
1), the total electricity use is 120,000 Btu/h / 11.9 Btu/Wh =
10,084 W, and the heat rejection fan adder is 120,000 Btu/h x (10 W
per 1,000 Btu/h) = 1,200 W.
---------------------------------------------------------------------------
v. Chilled Water Coil Exclusion
In the July 2017 ASHRAE TP RFI, DOE noted that section 2 of ANSI/
ASHRAE 198-2013 specifically excludes equipment with water coils that
are supplied by a chiller located outside of the unit. 82 FR 34427,
34438 (July 25 2017). However, Table 2 in ANSI/AHRI 920-2015 includes
operating conditions for which a water-cooled condenser is supplied
with chilled water, and ASHRAE 90.1-2016 established standard levels
for DDX-DOASes that operate with chilled water as the condenser cooling
fluid. As part of the July 2017 ASHRAE TP RFI, DOE requested
confirmation that the ANSI/ASHRAE 198-2013 chiller exclusion applies to
cooling coils rather than condenser coils. Id.
In response to the July 2017 ASHRAE TP RFI, AHRI commented that
both ANSI/AHRI 920-2015 and ANSI/ASHRAE 198-2013 were designed for
units that contain vapor compression cycle-based cooling and
dehumidification with direct expansion coils. AHRI stated that direct
application of chilled water coils to cool and dehumidify is outside
the scope of the standard, as the energy for cooling is expended at an
external source of chilled water. (AHRI, No. 11 at p. 18) Carrier
commented that chillers should
[[Page 36036]]
only be used for cooling coils and not for condenser heat rejection
unless there is heat reclaim, and that this should be addressed through
a building efficiency standard such as ASHRAE 90.1. (Carrier, No. 6 at
p. 7)
AHRI 920-2020 did not make a change to the exclusion of DOASes with
water coils that are supplied by a chiller located outside of the unit;
AHRI's comment explains that the exclusion exists because chilled water
coil units that use the chilled water for cooling are not DX units, and
the industry test procedures are only for DOASes with DX cooling.
ASHRAE Standard 90.1 does not include standards for non-DX DOASes such
as those with chilled water coils used for cooling. Based on AHRI 920-
2020, and ANSI/ASHRAE 198-2013 as referenced, and the comments
received, DOE did not consider DOAS units that use chilled water coils
directly for cooling and dehumidifying. However, the comments provided
in response to the July 2017 ASHRAE TP RFI, as discussed in section
III.B.3.e.i of this document, indicate that DX-DOASes and DDX-DOASes
may still use chilled water for condenser coils. (AHRI, No. 11 at p.
17)
f. Defrost Energy Use for Air-Source Heat Pump
In the July 2017 ASHRAE TP RFI, DOE noted that tests conducted at
35 [deg]F dry-bulb temperature for consumer central air conditioning
heat pumps (which are air-source) consider the impacts of defrosting of
the outdoor coil in the energy use measurement (see section 3.9 of 10
CFR part 430, subpart B, appendix M), while defrost is not addressed in
ANSI/ASHRAE 198-2013. 82 FR 34427, 34436 (July 25 2017). DOE stated
that defrost has a real impact on efficiency because of energy use
associated with defrost and because a system cannot continue to provide
heating during defrost operation, thereby reducing time-averaged
capacity. Id. Hence, DOE noted that consideration of defrost could
provide a more field-representative measurement of performance. DOE
requested comment on whether testing for test condition E of ANSI/AHRI
920-2015 Table 2 (i.e., 35 [deg]F dry-bulb/29 [deg]F wet-bulb) should
consider energy use associated with defrost. Id.
On this issue, AHRI commented that, due to the constant volume
nature of the airflow in DDX-DOASes, the addition of defrost to DDX-
DOASes presents challenges, and it is not in a position to present a
proper solution at this time. AHRI also stated that it is aware of
manufacturers that disable the heat pump operation in cold temperatures
to avoid this issue. (AHRI, No. 11 at p. 13) The Joint Advocates,
Goodman, and Carrier commented that defrost should be accounted for in
the test procedure to provide a more representative measurement of
field energy use. (Joint Advocates, No. 9 at p. 4; Goodman, No. 14 at
p. 2; Carrier, No. 6 at p. 4) Carrier added that DOE should use the T-
test \26\ defined in ANSI/AHRI 340/360 and ANSI/AHRI 210/240. (Carrier,
No. 6 at p. 4) Goodman indicated that it will be very difficult to
precisely capture defrost in the DDX-DOASes test procedure. (Goodman,
No. 14 at p. 2)
---------------------------------------------------------------------------
\26\ The T-test is a non-steady-state (transient) test that
includes measurement of both the heating energy use as the outdoor
coil accumulates frost and the defrost energy use as the unit
undergoes multiple defrost cycles, as referenced in section 8.8.3 of
ANSI/ASHRAE 37-2009.
---------------------------------------------------------------------------
DOE understands that AHRI is referring to challenges in field
operation defrosting for air-source heat pump DDX-DOASes. Preventing
cold outdoor air from being brought into the supply air stream during a
defrosting sequence (when the DDX-DOAS cannot operate as a heat pump)
would require interruptions to the supply airflow, which is
inconsistent with building code requirements to provide a continuous
supply of ventilation air for most DDX-DOAS applications. DOE is aware
of only a limited number of air-source heat pump DDX-DOAS units. DOE
understands that these units may not continue heat pump operation
during potential frosting conditions as a result of these challenges in
field operation. Given these factors, DOE is not aware of test data
(e.g., from T-tests) for such heat pumps during extended heating mode
operation to understand better the level of frost accumulation and
associated defrost energy expenditure. DOE also notes that AHRI 920-
2020 does not include any provisions for testing or calculating the
defrost energy of DDX-DOAS air-source heat pumps. However, AHRI 920-
2020 arguably addresses this issue in another fashion, namely by
providing in section 5.5 that defrost control settings specified by the
manufacturer in installation instructions may be set prior to heating
mode tests in order to achieve steady-state conditions during the
heating mode tests. As discussed in section III.B.3.d of this document,
DOE is proposing to adopt the provisions of AHRI 920-2020 section 5.5,
Defrost Controls for Air-Source Heat Pump during Heating Mode, as
enumerated in section 2.2.1(b) of the proposed Appendix B. If these
settings fail to prevent frost accumulation during the heating mode
tests (resulting in unsteady conditions), then the manufacturer would
need to seek a waiver from the test procedure to obtain an alternate
method of test from DOE pursuant to 10 CFR 431.401. However, section
5.5 of AHRI 920-2020 also specifies that the Standard Rating Condition
F heating mode test (which represents low temperature environmental
conditions where frosting is likely) is optional to conduct, and if the
Standard Rating Condition F test is not conducted, a default COP of 1.0
(corresponding to electric resistance heating) is assigned at this
rating point instead. Therefore, the manufacturer may choose to not
conduct a test at Standard Rating Condition F instead of seeking a
waiver. DOE has tentatively concluded that the test method set forth in
section 5.5 of AHRI 920-2020 for defrost controls for air-source heat
pump DDX-DOASes during heating mode offers a reasonable and workable
approach, so the Department proposes to adopt such approach into the
Federal test procedure.
Due to the lack of sufficient information on how air-source heat
pump DDX-DOAS units operate under frosting conditions, DOE is not
proposing to include any provisions for including the defrost energy of
DDX-DOAS air-source heat pumps.
g. General Control Setting Requirements
Requirements for adjustment of unit controls during set-up for
testing of a DDX-DOAS are addressed in specific sections of AHRI 920-
2020. Some examples include the following. Section 5.2, ``Equipment
Installation,'' requires that units be installed per manufacturer's
installation instructions (MII). Section 5.4.3, ``Deactivation of
VERS,'' indicates that operation of the VERS may be deactivated for
Standard Rating Conditions C or D if the VERS is capable of being
deactivated. Section 5.5, ``Defrost Controls for Air-Source Heat Pump
during Heating Mode,'' provides instructions for setting of defrost
controls.
However, DOE notes that the test standard provides no general
requirements indicating whether control settings can be adjusted as the
test transitions through the four Standard Rating Conditions used for
testing. Manual readjustment of control settings would not generally
occur in field operation of DDX-DOASes as outdoor air conditions change
(i.e., in the field, controls are configured at the time of
installation and would not be actively adjusted on an ongoing basis in
response to changes in outdoor temperature or humidity). Hence, to
further ensure the representativeness of the test procedure, DOE is
proposing
[[Page 36037]]
inclusion of a general requirement that control settings remain fixed
and that there be no further manual adjustment thereof, once set
initially for the first of the Standard Rating Conditions (Standard
Rating Condition A). Absent such instruction, the controls could be
adjusted as the test transitions through the four Standard Rating
Conditions used for testing, which as discussed, would not be
representative of the operation of the unit in the field. As such, DOE
has initially determined, supported by clear and convincing evidence,
that absent instruction for the control settings to be fixed during
testing, the industry test procedure would not meet the statutory
requirements of 42 U.S.C. 6314(a)(2)-(3) and is, therefore, proposing
such instruction.
Notwithstanding this proposal, DOE recognizes that some manual
intervention, as permitted by AHRI 920-2020, and as specified in
supplemental test instructions (STI),\27\ may be necessary as the test
transitions through Standard Rating Conditions. However, such manual
interventions are only permitted in limited and specific instances as
identified in the test standard or STI. An example of such an allowed
intervention is the use of the manual setting of compressor capacity
staging for tests using the ``Weighted average method,'' as described
in section 6.9.1 of AHRI 920-2020. In field operation, a DDX-DOAS set
per the manufacturer's installation instructions would attempt to
achieve the target supply air dew point over the average of a time
period with cycling (unsteady) operation between two compressor stages;
to address this, the test standard calls for manual intervention, using
two steady-state tests, one using each stage, and calculating a
weighted average of the results. (This provision is discussed in depth
in section III.B.3.d.v of this NOPR.)
---------------------------------------------------------------------------
\27\ ``STI'' is defined in AHRI 920-2020 as additional
instructions provide by the manufacturer and certified to the U.S.
DOE. As explained in section III.C.1 of this document, this NOPR
does not propose certification requirements for DDX-DOAS--such
requirements will instead be proposed in a separate Energy
Conservation Standard rulemaking. Consistent with certification
provisions for other commercial packaged air-conditioning and
heating equipment, manufacturers include STI as part of the
certification (see 10 CFR 429.43(b)(4)). DOE is proposing that
manufacturers must adhere to the provisions of this test procedure
starting on the compliance date for the related energy conservation
standard rulemaking. Hence, this approach does not require that STI
exist earlier than the date it must be certified to DOE.
---------------------------------------------------------------------------
Thus, DOE is proposing to require that all control settings are to
remain unchanged for all Standard Rating Conditions once system set-up
has been completed, and component operation shall be controlled by the
unit under test once the provisions in section 6 of AHRI 920-2020
(Rating Requirements) are met, except as specifically allowed by the
test standard or STI (see section 2.2.1(b)(i) of the proposed Appendix
B).
Issue-7: DOE requests comment on the proposed general control
setting requirement for DDX-DOASes.
h. Ventilation Energy Recovery Systems
As discussed in section III.A.1 of this NOPR, the industry
definition of ``DX-Dedicated Outdoor Air System Units'' is inclusive of
units that provide pre-conditioning of outdoor air by direct or
indirect transfer with return/exhaust air using an enthalpy wheel,
sensible wheel, desiccant wheel, plate heat exchanger, heat pipes, or
other heat or mass transfer apparatus. These pre-conditioning features
are broadly referred to as ventilation energy recovery systems
(``VERS'', or ``energy recovery''). ASHRAE Standard 90.1-2016 defines
separate equipment classes and efficiency levels for DDX-DOASes with
VERS.
Section 5.4 of AHRI 920-2020 specifies testing requirements for
DDX-DOASes equipped with VERS. Section 5.4.1 of AHRI 920-2020 specifies
that units equipped with VERS can be tested using either one of two
options: ``Option 1'' or ``Option 2''. Option 1 requires operating the
DDX-DOAS unit with VERS as it would operate in the field, maintaining
the appropriate return air and outdoor air conditions for airflows
entering the unit, and operating the VERS to provide energy recovery
during the test (see section 5.4.1.1 of AHRI 920-2020).\28\ In addition
to specifying the outdoor air dry-bulb temperature and humidity
conditions, Table 4 and Table 5 of AHRI 920-2020 specify return air
inlet conditions that are applicable to DDX-DOASes with VERS. Section
C2.4 in Appendix C of AHRI 920-2020 also specifies that the return air
be ducted into the unit from a separate test room maintaining the
required return air inlet conditions.
---------------------------------------------------------------------------
\28\ The Option 1 test method includes additional specificity to
the test room configuration for testing DDX-DOAS with energy
recovery by allowing use of the three-chamber approach in addition
to the example configuration provided in the current industry
consensus test standard, in which the outdoor room is conditioned to
both the required outdoor dry-bulb and humidity conditions.
---------------------------------------------------------------------------
Option 2 involves setting the conditions of the air entering the
unit so as to simulate the conditions that would be provided by the
VERS in operation (see section 5.4.1.2 of AHRI 920-2020). Option 2 uses
energy recovery device performance ratings based on ANSI/AHRI 1060-2018
to calculate the air dry-bulb temperature and humidity conditions that
would be provided by the energy recovery device. ANSI/AHRI 1060-2018
references ANSI/ASHRAE 84-2013, ``Method of Testing Air-to-Air Heat/
Energy Exchangers,'' (ANSI/ASHRAE 84-2013) (approved by ASHRAE on
January 26, 2013) for conducting the test. These industry test
standards provide a method for rating the performance of VERS in terms
of sensible and latent effectiveness. DOE also notes that the
performance ratings for energy recovery devices certified using ANSI/
AHRI 1060-2018 are listed in AHRI's directory of certified product
performance.\29\
---------------------------------------------------------------------------
\29\ AHRI's directory of certified product performance for air-
to-air energy recovery ventilators can be found at
www.ahridirectory.org/ahridirectory/pages/erv/defaultSearch.aspx.
---------------------------------------------------------------------------
The operating conditions specified in ANSI/AHRI 1060-2018 may be
different than the operating conditions specified for testing DDX-DOAS
(i.e., airflow rate, which subsequently affects factors such as
transfer/leakage airflow \30\). Hence, section C4 of AHRI 920-2020
provides methods to adjust, for the DDX-DOAS operating conditions, the
effectiveness values for sensible and latent transfer measured using
ANSI/AHRI 1060-2018. Section C4 of AHRI 920-2020 also provides default
values for sensible effectiveness and latent effectiveness. These can
be used in cases where performance rating information based on ANSI/
AHRI 1060-2018 is not available for a VERS, or the rotational speed for
an energy recovery wheel has been changed from the speed used to
determine performance ratings using ANSI/AHRI 1060-2018.
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\30\ As discussed in section III.B.4.g.i of this NOPR, DDX-
DOASes with energy recovery wheel VERS may experience air transfer
and leakage from the outdoor air path to the exhaust air (outdoor
air transfer and leakage) and return air to the supply air (return
air transfer and leakage).
---------------------------------------------------------------------------
The Option 2 approach would reduce test burden for most test
laboratories by reducing the number of test rooms required as compared
to conducting tests using Option 1. Because the outdoor ventilation air
and return air would be maintained at the same conditions, there would
be no transfer of heat or moisture in the VERS, nor any change of VERS-
outlet supply air conditions associated with transfer or leakage of
return air to the supply air plenum. In addition, testing using Option
2 is conducted with all components operating (e.g., with an energy
recovery wheel rotating, or with the pump of a glycol-water runaround
loop activated), such that all measurements would be representative
[[Page 36038]]
of the pressure drops and power consumption associated with the VERS.
This approach avoids separate testing to measure power input of
auxiliary components or of the exhaust air fan.
Option 2 is applicable for DDX-DOASes for which a VERS provides the
initial outdoor ventilation air treatment. DDX-DOAS units with VERS
that provide conditioning downstream of the conditioning coil could not
be tested using Option 2, since this option addresses VERS pre-
conditioning only upstream of the conditioning coil. Such units would
need to be tested using Option 1.
In response to the July 2017 ASHRAE TP RFI, AHRI commented that
testing of DDX-DOAS units with VERS would generally require a facility
with three adjacent test chambers, which is not available in the known
stock of existing laboratory spaces. (AHRI, No. 11 at p. 14) AHRI
stated that the test facility arrangement for testing of DDX-DOASes
with energy recovery presented in ANSI/ASHRAE 198-2013,\31\ as
referenced by AHRI 920-2020, is not adequate because laboratories
cannot maintain both the required dry-bulb temperature and high
humidity conditions in the outdoor room, since removing the high
condenser heat load using a conventional conditioning system also
excessively dehumidifies the chamber. The commenter also argued that
capacity and stratification are significant issues with the existing
test arrangement. AHRI surmised that a separate, third test room to
provide conditioned outdoor air for the entering air to the energy
recovery device would be required to provide adequate stability for
testing. AHRI further asserted that because it is not feasible to
adequately test units with VERS, DOE should limit the scope of the
Federal test procedure at this time to DDX-DOAS units without VERS.
(AHRI, No. 11 at p. 15)
---------------------------------------------------------------------------
\31\ See section 6.1.1.2 and Figure 2 of ANSI/ASHRAE 198-2013.
---------------------------------------------------------------------------
Based on DOE's review of the test requirements and equipment
available on the market, DOE is aware of test facilities capable of
testing using Option 1 for smaller DDX-DOAS units. Test facilities with
similar configurations used for testing variable refrigerant flow
multi-split air-conditioning and heat pump equipment would be large
enough and equipped with enough controlled test rooms to meet the DDX-
DOAS test procedure requirements. DDX-DOAS units with physical
dimensions under 10 feet by 10 feet (typically less than 100 lbs. per
hour MRC at Standard Rating Condition A), which represent more than 50
percent of equipment models available on the market, could be tested in
these existing test facilities.
Option 2 allows existing test facilities to test all DDX-DOAS
units, including units larger than those that can be tested using
Option 1. As discussed, Option 2 requires neither a separate third test
room to condition the outdoor ventilation air to the required
temperature and humidity conditions, nor that the outdoor room in which
the unit is located be conditioned to both the required dry-bulb and
humidity conditions, because it does not require use of an air stream
at outdoor air conditions. Aside from the chamber in which the test
unit is installed, it requires only a second chamber at the simulated
conditions. The inclusion of Option 2 in AHRI 920-2020 reduces testing
burden compared to the ANSI/AHRI 920-2015, which only provides test
set-up and provisions that are mostly equivalent to the Option 1 method
in AHRI 920-2020 discussed previously. For these reasons, DOE
tentatively concludes that existing test facilities would be capable of
using the proposed test procedure for testing DDX-DOASes both with and
without VERS.
DOE is required under EPCA to adopt a Federal test procedure that
is consistent with the applicable test procedure specified in the
amended ASHRAE Standard 90.1 unless DOE determines, supported by clear
and convincing evidence, that to do so would result in a test procedure
that is not designed to produce test results which reflect the energy
efficiency of DDX-DOASes in a representative average-use cycle or would
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(4)(B); 42 U.S.C.
6314(a)(2) and (3)) In this NOPR, DOE is proposing to adopt the two
options (i.e., Option 1 and Option 2) for testing DDX-DOASes with
energy recovery, as provided in section 5.4.1 of AHRI 920-2020 (as
enumerated in section 2.2.1(b) of the proposed Appendix B). As
discussed further in section III.B.3.a of this NOPR, DOE is proposing
to define a ``ventilation energy recovery system'' as a feature that
provides pre-conditioning of outdoor ventilation air entering the
equipment through direct or indirect thermal and/or moisture exchange
with the exhaust air leaving the unit.
In addition, DOE notes that the relevant industry test standards
(AHRI 920-2020 and ASHRAE 198-2013) in some cases use synonymous but
different terms to denote VERS. DOE proposes to include a section
2.3(b) in its proposed Appendix B indicating that the different
synonymous terms all refer to VERS as defined in 10 CFR 431.92.
The following subsections address specific aspects of the proposed
test procedure pertaining to DDX-DOASes with VERS.
i. Exhaust Air Transfer and Leakage
DOE is aware that DDX-DOASes with energy recovery wheel VERS may
experience air transfer and leakage from the outdoor air path to the
exhaust air (outdoor air transfer and leakage) and return air to the
supply air (return air transfer and leakage). Some of this air is
leakage past the diametral seals that separate the outdoor and exhaust
plenums on one side of the wheel and the return and supply plenums on
the other side. Additional leakage from outdoor to exhaust or return to
supply could be due to loose cabinet construction of the DDX-DOAS
itself. Depending on the geometry of the energy recovery wheel media
(e.g., whether the sheets of media making up the energy recovery wheel
core are oriented parallel to this leakage flow direction), the air may
pass through a portion of the media near the diametral seal. In
addition, as a portion of the wheel passes from one side of the seal to
the other, the air within that portion reverses direction--this
represents either return air transferred to the supply side or outdoor
air transferred to the exhaust side. The exhaust air transfer ratio
(EATR) is defined in section 3.8 of AHRI 920-2020 as the fraction of
airflow leaving the VERS that transfers or leaks from the return air
inlet rather than passing through the VERS from the outdoor air inlet.
The return air that transfers and leaks to the supply air side of
an energy recovery wheel did not enter the DDX-DOAS as outdoor
ventilation air. Therefore, the amount of fresh outdoor air delivered
by the DDX-DOAS is less than the supply airflow and is equal to the
supply airflow multiplied by the factor (1-EATR). In addition, the
return air is already at neutral space conditions. Hence, the energy
recovery wheel does not provide any meaningful conditioning for this
air. When calculating MRC for a DDX-DOAS with an energy recovery wheel,
section 10.5 of ANSI/ASHRAE 198-2013 indicates that the calculation is
based on the full supply airflow. DOE notes that any transfer or
leakage air would increase the apparent dehumidification provided by
the DDX-DOAS unit, since this air is already at space-neutral
conditions--thus, a high EATR would boost the efficiency rating without
providing any real benefit (for VERS other than energy recovery wheels,
the EATR is considered to be equal to 0, under the assumption that
cabinet air leakage
[[Page 36039]]
through the VERS is negligible, so this issue would not affect these
other VERS). ANSI/AHRI 920-2015 includes tracer gas tests for measuring
EATR in its standard rating requirements (see section 5.1). As part of
the July 2017 ASHRAE TP RFI, DOE raised this issue, while recognizing
that such leakage may be low enough in most energy recovery wheels that
the EATR measurement could represent an unnecessary addition to test
burden. 82 FR 34427, 34437 (July 25 2017). DOE requested comment on
whether EATR should be included in the test procedure for DDX-DOASes
and, if so, how it should be used in determining DX-DOAS ratings. Id.
In response to the RFI, on this issue, AHRI commented that the
intent of the DOE test procedure for DDX-DOASes should not be to
quantify energy recovery performance. AHRI pointed out that the AHRI
certification directory publishes EATR values based on AHRI 1060.
(AHRI, No. 11 at p. 15) In addition, AHRI argued that test laboratories
of sufficient size for testing DDX-DOASes are not currently equipped
with tracer gas test equipment, as specified in ANSI/ASHRAE 84-2013.
(AHRI, No. 11 at p. 14) No other comments were received on this issue.
Since the July 2017 ASHRAE TP RFI, further refinements were made to
the industry consensus test standard which have bearing on this matter.
Specifically, sections 6 and C4 of AHRI 920-2020 were revised to
include methods to estimate EATR without requiring a tracer gas
measurement, and to account for EATR's impact on DDX-DOAS performance,
using calculations tailored for testing under either Option 1 or Option
2. These include using an EATR value that is based on testing in
accordance with ANSI/AHRI 1060-2018 with zero purge angle,\32\ zero
return-to-supply pressure differential, and 100-percent of nominal
energy recovery wheel supply airflow, and adjusting the EATR value for
the DDX-DOAS supply airflow rate based on an assumption that the
leakage/transfer flow is not affected by the supply and return air flow
rates. The adjusted value of EATR is then used in the calculation of
DDX-DOAS performance. Specifically, the MRC calculations in section 6.9
of AHRI 920-2020 take into account the conditioning of the air that
leaked or transferred from the return plenum to the supply plenum
(equal to adjusted EATR multiplied by supply airflow) only from return
conditions to supply conditions to reflect the fact that this air did
not enter the DDX-DOAS unit at outdoor air conditions. In cases where
EATR rating information based on ANSI/AHRI 1060-2018 is not available,
or if, for an energy recovery wheel, the rotational speed has been
changed from the speed used to determine performance ratings using
ANSI/AHRI 1060-2018, sections 6.5 and C4 of AHRI 920-2020 provide a
default value of EATR that would be used to rate the DDX-DOAS.
---------------------------------------------------------------------------
\32\ A purge mechanism cleans the portion of the wheel that has
had contact with return air before it is used to precondition
outdoor air. The cleaning is provided by outdoor air that passes
through this portion of the wheel and is diverted into the return
plenum to be discharged through the exhaust blower. Most purge
mechanisms allow adjustment of the angle of the wheel sector that is
subject to this cleaning function. At zero purge angle, there is no
purge cleaning provided.
---------------------------------------------------------------------------
DOE has tentatively determined that the use of default or certified
values for EATR in AHRI 920-2020 (instead of tracer gas tests) has
addressed AHRI's comments on quantifying energy recovery performance.
Accordingly, DOE is proposing to adopt these changes made by AHRI 920-
2020 (section 6.5 Determination of EATR), as enumerated in section
2.2.1(c) of the proposed Appendix B; and Appendix C of AHRI 920-2020
(which includes section C4 Simulated Ventilation Air Conditions for
Testing Under Option 2), as enumerated in section 2.2.1(f) of the
proposed Appendix B).
ii. Purge Angle Setting
Section 6.6 of ANSI/ASHRAE 198-2013 requires that for any DDX-DOAS
equipped with an energy recovery wheel, the purge angle of such feature
must be set to zero when testing the DDX-DOAS unit. As part of the July
2017 ASHRAE TP RFI, DOE requested comment on whether all purge devices
are adjustable to zero purge and whether it is always clear how to set
them to zero purge. 82 FR 34427, 34439 (July 25, 2017). DOE also
requested comment on whether it is appropriate to set purge to zero or
whether it would be more appropriate to set purge to its highest
setting or to some other standard setting. Id.
None of the comments on the RFI indicated that there are purge
devices that are not adjustable to zero angle, nor that it is unclear
how to adjust purge angle to zero. Carrier commented that for the short
period of time required for a performance test, it should not be a
problem to set the purge angle to zero. (Carrier, No. 6 at p. 8) As
discussed previously, AHRI stated that there are no independent
laboratories capable of testing DDX-DOAS units with VERS. As a result,
AHRI argued that this issue does not need to be addressed at this time.
However, AHRI stated, if in the future laboratories are able to test
DDX-DOASes equipped with VERS, then manufacturers should be allowed to
specify the purge setting for testing, as is done in AHRI 1060. (AHRI,
No. 11 at p. 20)
DOE has tentatively concluded that a zero purge angle aligns with
the selection that manufacturers would generally make (i.e., a zero
purge angle), because non-zero purge prevents the purge portion of the
wheel from contributing to energy recovery effectiveness (since outdoor
ventilation air passing through it is ejected out of the unit to the
exhaust rather than becoming part of the supply airflow). Also, the
purge section restricts the flow area for the remaining outdoor air
that becomes supply air, thus increasing pressure drop and fan power.
For these reasons, energy recovery wheel performance (and likewise DDX-
DOAS performance and efficiency) will be reduced when operating with a
non-zero purge angle. Furthermore, basing DDX-DOAS performance ratings
on a zero purge angle provides greater consistency in testing. DOE
notes that section C4.1 of AHRI 920-2020--the industry consensus test
standard--includes a requirement for testing DDX-DOAS units using zero
purge angle, whether testing using Option 1 or Option 2 (through
inclusion of EATR0, which is defined in section 11 of AHRI
920-2020 as being determined using zero purge angle). For these
reasons, DOE is proposing to adopt the requirement in AHRI 920-2020 to
use a zero purge angle for testing DDX-DOAS with energy recovery wheels
(section C4.1 of Appendix C of AHRI 920-2020), as enumerated in section
2.2.1(f) of the proposed Appendix B.
iii. Return Air External Static Pressure Requirements
ANSI/ASHRAE 198-2013 specifies testing DDX-DOASes with VERS with
return air passing into the unit and exiting at the exhaust air
connection. DOE noted in the July 2017 ASHRAE TP RFI that ANSI/AHRI
920-2015 does not address setting the external static pressure (ESP)
for the return airflow. 82 FR 34427, 34437 (July 25, 2017). DDX-DOAS
units are typically installed and operated in the field with return air
ducting. Therefore, when in operation, the return air fans consume
additional energy to overcome the static pressure imposed by the return
air ducts. As part of the July 2017 ASHRAE TP RFI, DOE requested
comment on the ESP levels that should be used for return airflow. Id.
In response, AHRI stated that Table 4 of ANSI/AHRI 920-2015 was
intended to represent ESP of both supply and return airflow. AHRI also
stated that
[[Page 36040]]
revisions to ANSI/AHRI 920-2015 will refer to the same table for return
airflow ESP. (AHRI, No. 11 at p. 15) DOE received no other comments on
this issue.
Consistent with the AHRI comment, section 6.1.5.6 of AHRI 920-2020
does include different ESP requirements for supply and return airflow,
thereby resolving the identified issue. Accordingly, DOE is proposing
to adopt the ESP requirements set forth in AHRI 920-2020 (section 6.1.5
Supply and Return Airflow Rates), as enumerated in section 2.2.1(c) of
the proposed Appendix B).
iv. Target Return Airflow Rate
In the July 2017 ASHRAE TP RFI, DOE noted that for testing DDX-DOAS
units equipped with VERS, Tables 2 and 3 in ANSI/AHRI 920-2015 provide
return airflow temperature conditions and indicate that the temperature
conditions apply to units with energy recovery at balanced airflow. 82
FR 34427, 34437 (July 25, 2017). It is unclear from ANSI/AHRI 920-2015
what airflow streams should be balanced, how to determine if they are
balanced, and within what tolerances they should be balanced. In the
July 2017 ASHRAE TP RFI, DOE requested comments on which airflow
streams should be balanced and whether balanced airflow is
representative of field use. Id.
On this topic, AHRI raised a number of issues with testing DDX-DOAS
equipped with VERS generally, as previously discussed. AHRI also stated
that using balanced airflows is consistent with the test procedure for
rating VERS described in ANSI/AHRI 1060-2018. AHRI further commented
that in field operation, unbalanced flows may be needed to maintain
positive building pressure; however, most equipment selection is done
at or near balanced airflows. (AHRI, No. 11 at pp. 14-15)
Subsequent updates to the industry consensus test standard at AHRI
920-2020 shed further light on this issue. Specifically, section 6.1.5
of AHRI 920-2020 specifies the return airflow rate must be within 3
percent of the measured supply airflow rate. Based on DOE's review of
DDX-DOAS product literature and consideration of the AHRI comment, it
has become apparent that there is no clear optimal ratio of supply
airflow to return airflow for DDX-DOAS testing to be representative of
field use. Therefore, DOE has tentatively concluded that the provision
in AHRI 920-2020 is appropriate.
i. Demand-Controlled Ventilation
DDX-DOAS units are often used in demand-controlled ventilation
(DCV) operation, which regulates the building ventilation requirement
based on parameters such as building occupancy. Typically, a DCV system
monitors the concentration of carbon dioxide (CO2) in the
return air or in the building and regulates the supply airflow rate
accordingly. During periods of non-occupancy, which could represent a
significant portion of field-use, the DCV system controls the unit to
operate at a low airflow rate, thereby reducing the unit's overall
energy use. DDX-DOASes using DCV systems are typically equipped with
variable-speed supply fans that can be adjusted to meet changing
ventilation needs. In the July 2017 ASHRAE TP RFI, DOE sought comments
on whether to include operation under DCV conditions (i.e., low supply
airflow conditions) to be included as part of DOE's test procedure. 82
FR 34427, 34437 (July 25, 2017).
In response to this issue, the Joint Advocates encouraged DOE to
adopt an efficiency metric that captures the benefits of DCV. The Joint
Advocates stated that adopting such a metric could provide more field-
representative equipment ratings and better inform consumers when
purchasing equipment. Further, the Joint Advocates argued that
capturing the benefits of DCV would promote adoption of variable speed
fans, provide more flexibility in building operation, and reduce energy
use. (Joint Advocates, No. 9 at p. 2, 4) AHRI and Carrier commented
that the performance of the DX-DOAS under DCV operation must be
characterized prior to developing a test procedure and that adopting
provisions to address DCV operation could significantly increase the
cost and complexity of testing. AHRI further stated that DCV operation
is primarily controlled by building operators. Carrier stated that
performance would depend highly on the building type, occupancy, and
site requirements for demand ventilation. (AHRI, No. 11 at p. 14;
Carrier, No. 6 at p. 4)
DOE reviewed the comments and considered whether to adopt testing
conditions to account for the energy use profiles of models with low
supply airflow rates that are typically experienced by units with DCV.
Incorporation of the airflow modulation that would be enabled by DCV
might provide more representative efficiency ratings, help in consumer
decision making, and potentially promote the market penetration of
variable speed fans. However, DOE is not aware of representative field
data regarding the typical DDX-DOAS duty cycle when operating with DCV
and, thus, agrees with the comments of AHRI and Carrier that
characterization of DCV performance would be an important first step in
integrating this control feature into the test procedure. DOE further
agrees that adopting additional testing requirements to capture the
effect of DCV could significantly increase testing cost and complexity,
as noted in comments provided by AHRI and Carrier. Given the lack of
data on in-field performance and the anticipated additional testing
burden of such a test, DOE has tentatively decided not to include
performance under DCV operation in its proposed test procedure for DDX-
DOASes at this time.
j. Tolerances for Supply and Return Airflow and External Static
Pressure
DOE noted in the July 2017 ASHRAE TP RFI that Table 1 of ANSI/
ASHRAE 198-2013 includes operating and condition tolerances of 5
percent for airflow rate. 82 FR 34427, 34439 (July 25, 2017). It
includes a test operating tolerance for ESP equal to 0.05 in
H2O and a test condition tolerance for ESP of 0.02 in
H2O. As provided in section 5.2.2 of ANSI/AHRI 920-2015, the
airflow rate and ESPs are set at Standard Rating Condition C dry-bulb
temperatures without the refrigeration systems and energy recovery (if
applicable) in operation. ANSI/AHRI 920-2015 states in section 5.2.2.4
that once the airflow rate is set, the fan speeds shall not be adjusted
for the remaining tests. DDX-DOAS units that are for use with air
ducting are required by the industry test standard to be set up with
ESP requirements in Table 4 of ANSI/AHRI 920-2015, and units tested as
if they would be installed without ducts are tested with 0 in
H2O ESP.
DOE notes that while operating in dehumidification mode, the
airflow rates and ESPs may fluctuate more than for ``dry'' operation as
condensate accumulates and then drains from the cooling coil. In
addition, for dehumidification and heating tests, the density of supply
air may be different, which may change fan performance, and, thus, the
ESP. These factors could cause the supply air ESP to fluctuate more
than the operating tolerances specified in Table 1 of ANSI/ASHRAE 198-
2013, and/or to deviate from the specified ESP by more than the test
condition tolerance. Likewise, the airflow rates could fluctuate more
than the specified operating tolerances, and the average airflows could
deviate by more than the test condition tolerances
[[Page 36041]]
from their target values. If this occurs, it is not clear how
manufacturers would correct the issue without being able to adjust the
fan speed and ESP, since such action is precluded by section 5.2.2.4 of
ANSI/AHRI 920-2015.
In the July 2017 ASHRAE TP RFI, DOE noted that the 5-percent
condition tolerance on airflow rate is less stringent than the 3-
percent condition tolerance adopted in DOE's test procedure for more
typical commercial package air equipment. 82 FR 344271, 34439 (July 25,
2017). On August 6, 2015, DOE published a test procedure NOPR that
proposed to apply a 5-percent condition tolerance on
cooling full-load indoor airflow rate for more typical commercial
package air conditioning equipment. 80 FR 46870, 46873. In response to
the proposed tolerance for more typical commercial package air
conditioning equipment, DOE received several comments suggesting that a
5-percent tolerance would result in too much variation in the
measurement of energy efficiency ratio and cooling capacity. After
considering stakeholder comments, DOE adopted a 3-percent tolerance in
a final rule published on December 23, 2015. 80 FR 79655, 79659-79660.
As part of the July 2017 ASHRAE TP RFI, DOE expressed concern that that
the 5-percent condition tolerance on airflow in ANSI/ASHRAE 198-2013
may result in too much test variability for DDX-DOASes and requested
comment on whether this airflow tolerance is acceptable. 82 FR 34427,
34439 (July 25, 2017).
AHRI commented in response to the July 2017 ASHRAE TP RFI that
manufacturers who have performed testing have stated that meeting the
tolerances specified in ANSI/AHRI 920-2015 and ASHRAE 198-2013 is not
feasible due to how the testing is performed. Once the refrigeration
system is engaged for determining ISMRE and ISCOP ratings, changes in
moisture present on the cooling coil and air density affect the
standard airflow and associated ESP. AHRI recommended that the 0.05 in H2O ESP tolerance and a 3-percent airflow
tolerance be observed during the airflow and fan speed setting at
Standard Rating Condition C without the refrigeration system operating.
AHRI also stated that during the Standard Rating Condition tests, the
DDX-DOAS fan speeds and airflow-measuring apparatus fan speeds shall
not be adjusted, consistent with airflow setting and operation in the
field. Nevertheless, AHRI stated that the average measured airflows
should be required to be within 5 percent of the manufacturer's rated
standard airflow during all rating tests and that the average measured
ESPs should be within 15 percent of the required ESP to indicate a
valid test, but the commenter did not indicate whether the fans of the
test unit or the airflow-measuring apparatus should be adjusted to
maintain these tolerances. (AHRI, No. 11 at p. 18)
DOE notes that AHRI 920-2020 revised the test condition and
operating tolerances for airflow and ESP. Section 6.1.5 of AHRI 920-
2020 specifies airflow test condition tolerances of 3
percent of the manufacturer-provided airflow rate for all DDX-DOASes
when setting the airflow, provided that this airflow rate meets the
supply air dew point temperature requirement, as discussed in section
III.B.4.d.i of this NOPR. For setting the return airflow rate, section
6.1.5 of AHRI 920-2020 specifies the same test condition tolerances as
for supply airflow rate, except that for return airflow rate, the
target is equal to the measured supply airflow rate. This specification
ensures that supply and return airflows remain balanced, as discussed
in section III.B.3.h.iv of this NOPR. These test condition tolerances
for airflow and ESP are only required when setting the airflow. Once
the airflow rate is set, the dehumidification and heating tests are
then conducted without further adjustments to the supply fan, return
fan, or airflow measuring apparatus. Section 6.1.5 and Table 9 of AHRI
920-2020 indicate that the supply and return airflow and ESP condition
tolerances are not required to be maintained during the
dehumidification and heating tests. While these provisions are contrary
to AHRI's recommendation in response to the July 2017 ASHRAE TP RFI to
impose a 5-percent airflow condition tolerance and a 15-percent ESP
condition tolerance during dehumidification and heating tests, DOE
believes these changes in AHRI 920-2020 address AHRI's concerns about
testing problems associated with the tolerances in ANSI/AHRI 920-2015
and ASHRAE 198-2013.
AHRI 920-2020 additionally includes a list of test operating
tolerances, including those for external static pressure and airflow
nozzle differential pressure. AHRI 920-2020 does not include changes to
the test operating tolerance for ESP (0.05 in H2O total observed range,
specified in Table 9 of AHRI 920-2020). Whereas ANSI/ASHRAE 198-2013
provides a 5-percent operating tolerance directly on the airflow rate,
Table 9 of AHRI 920-2020 provides a 5-percent operating tolerance for
airflow rate in the form of airflow nozzle differential pressure. DOE
has initially determined that the airflow operating tolerance approach
in AHRI 920-2020 is preferable because the airflow nozzle differential
pressure provides a more direct indication of the airflow variation,
since airflow is calculated based on this value. Additionally, other
industry test standards such as ANSI/ASHRAE 37-2009 include an
operating tolerance on the nozzle pressure drop rather than directly on
airflow. DOE believes that these operating tolerances, in addition to
the condition tolerances for setting airflow, would maintain repeatable
and reproducible results while ensuring that testing is representative
of field use. Accordingly, DOE is proposing to adopt the test condition
and operating tolerances for airflow and ESP specified in AHRI 920-2020
(section 6.1.5 Supply and Return Airflow Rates and section 6.6.2 Test
Measurement Tolerances, which contains Table 9), as enumerated in
section 2.2.1(c) of the proposed Appendix B).
k. Secondary Dehumidification and Heating Capacity Tests
Commercial package air-conditioners and heat pumps with cooling
capacity less than 135,000 Btu/h are required to undergo a secondary
test to verify the cooling or heating capacity and energy efficiency
results (see, e.g., ANSI/ASHRAE 37-2009 section 7.2.1, which is
referenced by appendix A to subpart F of 10 CFR part 431). Neither
ANSI/AHRI 920-2015 nor ANSI/ASHRAE 198-2013 specify a secondary test
method for verifying the dehumidification and heating capacity of DDX-
DOAS, but section 6.7 of AHRI 920-2020 does specify secondary tests.
The measurement of dehumidification and heating performance of DDX-
DOASes is based on measurements of airflow rate, temperature, and
humidity, which have uncertainties associated with them. Thus, a
secondary test method may be essential to confirm the accuracy of the
primary test method.
As part of the July 2017 ASHRAE TP RFI, DOE requested comment on
the need for a secondary test method requirement for DDX-DOAS testing.
82 FR 34427, 34439 (July 25, 2017). AHRI commented that condensate
measurement would be appropriate as a secondary method, if energy
recovery units are excluded from the test procedure. (AHRI, No. 11 at
p. 19)
Section C5.1 of AHRI 920-2020 includes a condensate-based test
method as a secondary measure of dehumidification capacity. The method
measures the weight of the condensate (i.e., water vapor in the outdoor
ventilation air that condenses on the conditioning coil and is removed
from
[[Page 36042]]
the air) collected during the dehumidification test and uses it to
calculate a secondary measure of MRC. This secondary measure of MRC is
then compared to the primary MRC measurement, which is based on supply
and outdoor ventilation airflow and air condition measurements.
AHRI 920-2020 requires this secondary measure of MRC for all
dehumidification tests, and comparison to the primary measure of MRC at
Standard Rating Condition A. This requirement is for all DDX-DOAS units
that: (a) Do not use condensate collected from the dehumidification
coil to enhance condenser cooling or include a secondary
dehumidification process for which the moisture removed from the supply
air stream is not collectable in liquid form, and (b) either are not
equipped with VERS or are equipped with VERS and tested using Option 2
(see section C5.1 of AHRI 920-2020). AHRI 920-2020 does not require a
secondary dehumidification capacity measurement for DDX-DOAS units
equipped with VERS that are tested using Option 1. DOE understands that
this is because: (a) No viable method has been developed and validated
that appropriately accounts for the water vapor that transfers between
air streams of an energy recovery wheel, and (b) the test burden of
accounting for moisture in the exhaust air stream would be excessive.
DOE is proposing to adopt the secondary capacity test measurements
specified in AHRI 920-2020 (section C5.1 Dehumidification Capacity
Verification), as enumerated in section 2.2.1(f) of the proposed
Appendix B), including the cooling condensate secondary test
measurement discussed previously.
For DDX-DOAS units with energy recovery tested using Option 2, as
discussed in section III.B.3.h of this NOPR, the test is conducted by
setting the conditions of the air entering the unit (at both the
outdoor air inlet and return air inlet) to simulate the conditions that
would be provided by the energy recovery device in operation. As a
result, the moisture removal (in dehumidification mode) or heating (in
heating mode for heat pump DDX-DOAS) measured during the Option 2
primary and secondary capacity tests reflects only the moisture removed
or heating by the conditioning coil. The MRC or qhp for the DDX-DOAS is
calculated by adjusting the measured moisture removal or heating for
the primary test to account for the total moisture removal or heating
by the energy recovery device and the conditioning coil. Because the
moisture removal or heating capacity measured for the primary and
secondary tests are based on the simulated test conditions, sections
6.9 and 6.10 of AHRI 920-2020 use these measured values for the
secondary capacity verification under Option 2. DOE is proposing to
adopt these requirements specified in AHRI 920-2020 (section 6.9
Moisture Removal Efficiency Ratings and section 6.10 Heating Capacity),
as enumerated in section 2.2.1(c) of the proposed Appendix B).
a. Corrections
In addition to substantive changes, AHRI 920-2020 also provides
minor corrections to instructions in ANSI/AHRI 920-2015. However, in
its review of AHRI 920-2020, DOE identified an error and an omission in
the latest industry test procedure. Specifically, DOE notes that
section 6.9.2 of AHRI 920-2020 provides erroneous instruction for the
calculation of the degradation coefficient, and sections 6.1.5.2.3 and
6.1.5.2.4 of AHRI 920-2020 refer to the term ``non-standard low-static
motor'' without providing a definition or explanation of this term. DOE
proposes to correct the calculation instruction and define the term
``non-standard low-static motor,'' as discussed further in the
following paragraphs. DOE also notes a correction made by AHRI 920-2020
to address an error in the calculation of supplementary heat penalty in
ANSI/AHRI 920-2015.
i. Calculation of the Degradation Coefficient
As mentioned in section III.B.3.d.v of this NOPR, AHRI 920-2020
includes provisions for cases where the unit provides excess
dehumidification or heating capacity when operating at its lowest-
capacity compressor stage. A degradation coefficient is applied to the
MRE and MRE70 when the supply air dew point temperature
measured when operating the unit at its lowest-capacity compressor
stage is lower than the target supply air dew point temperature in
excess of the specified test condition tolerance. This degradation
coefficient accounts for the re-evaporation of condensate which occurs
during cycling operation (i.e., when the compressor cycles on and off
to achieve the target supply air dew point temperature). DOE
understands that the degradation is more pronounced for DDX-DOASes
equipped with VERS for latent energy recovery (or total energy
recovery), and, thus, the degradation coefficient should be greater for
DDX-DOASes operating total energy recovery VERS. Equation 20 in section
6.9.2 of AHRI 920-2020 appears to incorrectly attribute the lower
degradation coefficient to DDX-DOASes operating with VERS. As such, DOE
has initially determined, supported by clear and convincing evidence,
that absent a correction, the degradation coefficient as applied in
AHRI 920-2020 would not meet the statutory requirements of 42 U.S.C.
6314(a)(2)-(3) because it would not produce representative results. DOE
proposes to correct Equation 20 by specifying that it is to be used for
DDX-DOASes ``without VERS, with deactivated VERS (see section 5.4.3 of
AHRI 920-2020), or with sensible-only VERS tested under Standard Rating
Conditions other than D'' (emphasis added) because DDX-DOASes with
total energy recovery VERS or with sensible-only VERS tested under
Standard Rating Condition D are considered separately in Equation 21,
which calculates a greater degradation coefficient. This correction
would be implemented in section 2.2.1(c)(iii) of proposed Appendix B.
ii. Non-Standard Low-Static Motor
As mentioned in section III.B.3.d.i of this NOPR, section 6.1.5 of
AHRI 920-2020 includes instructions for setting the supply airflow rate
for testing. In particular, sections 6.1.5.2.1 through 6.1.5.2.5 of
AHRI 920-2020 provide directions for adjusting the fans should an
initial attempt at setting the airflow be unsuccessful.
Section 6.1.5.2.3 of AHRI 920-2020 specifies that if a fan's
maximum speed is too low to satisfy the airflow and external static
pressure requirements within tolerance (i.e., the motor speed is at the
highest setting, a larger compatible off-the-shelf sheave is not
available, or increased speed would overload the motor or motor drive)
and the motor is not a ``non-standard low-static motor,'' the tests are
to be conducted at the fan's maximum speed with the external static
pressure satisfying the requirements in Table 7. However, if the motor
is a ``non-standard low-static motor,'' section 6.1.5.2.4 of AHRI 920-
2020 specifies that the maximum available speed should be used but the
supply and return airflow rates should satisfy aforementioned tolerance
requirements (implying that the external static pressure requirements
in Table 7 need not be met). AHRI 920-2020 does not define ``non-
standard low-static motor'' in order to determine which of the two
methods is appropriate. Without a definition of ``non-standard low-
static motor,'' manufacturers may not apply the ``maximum speed''
provisions consistently, and the potential for variation risks results
that do not reflect the equipment's representative average energy
efficiency or energy use. As
[[Page 36043]]
such, DOE has initially determined, supported by clear and convincing
evidence, that in the absence of a definition of ``non-standard low-
static motor,'' the industry test procedure would not meet the
statutory requirements of 42 U.S.C. 6314(a)(2)-(3).
DOE understands that a non-standard low-static fan motor may be
used for DDX-DOASes where the application requires less ductwork, which
results in a lower external static pressure when operating at the same
nominal supply or return airflow rate. This motor would be distributed
in commerce as part of an individual model within the same basic model
of DDX-DOAS that is also distributed in commerce with a motor that can
meet the external static pressure required by AHRI 920-2020. A parallel
situation occurs for Commercial and Industrial Unitary Air-conditioning
and Heat Pump Equipment, for which section D3 in Appendix D of AHRI
Test Standard 340/360-2019, ``Performance Rating of Commercial and
Industrial Unitary Air-conditioning and Heat Pump Equipment'' (AHRI
340/360-2019) defines ``non-standard motor'' as an indoor fan motor
that is not the standard indoor fan motor and that is distributed in
commerce as part of an individual model within the same Basic Model.
The same section D3 defines ``standard indoor fan motor'' as the motor
specified by the manufacturer for testing and shall be distributed in
commerce as part of a particular model. In both cases, the non-standard
motor has a horsepower level that is not compatible with the external
static pressure rating condition--for DDX-DOAS, the issue arises when
the non-standard motor does not have sufficient power to deliver the
required external static pressure. Therefore, in the proposed Appendix
B in section 2.2.1(a)(i), DOE is proposing to define ``non-standard
low-static fan motor'' as a supply fan motor that cannot maintain
external static pressure as high as specified in Table 7 of AHRI 920-
2020 when operating at a manufacturer-specified airflow rate and that
is distributed in commerce as part of an individual model within the
same basic model of a DDX-DOAS that is distributed in commerce with a
different motor specified for testing that can maintain the required
external static pressure.
Issue-8: DOE is requesting comment on the proposed definition of
``non-standard low-static fan motor'' and whether the proposed
definition reflects stakeholder understanding of the term.
iii. Calculation of Supplementary Heat Penalty
Section 6.1.3.1 of ANSI/AHRI 920-2015 includes a supplementary heat
penalty for units that are unable to achieve the minimum supply air
dry-bulb temperature of 70 [deg]F while testing at each Standard Rating
Condition specified in Table 2 and Table 3 of ANSI/AHRI 920-2015. The
supplementary heat penalty calculates the difference in enthalpy from
the delivered supply air and air at the minimum supply air temperature
(70 [deg]F). After reviewing the equations, DOE noted in the July 2017
ASHRAE TP RFI that the term for supply airflow rate is missing from the
supplementary heat penalty equations. 82 FR 34427, 34436 (July 25,
2017).
In response to the July 2017 ASHRAE TP RFI, AHRI confirmed that the
supplementary heat formula in ANSI/AHRI 920-2015 is missing the airflow
term, QSA, in section 6.1.3.1, and the organization committed to
include such term in the next revision of the test standard. (AHRI, No.
11 at p. 11) DOE notes that this change has been included in AHRI 920-
2020, thereby resolving the problem. Accordingly, DOE proposes to adopt
the revised supplementary heat penalty equation contained in AHRI 920-
2020 that includes the supply airflow rate term (section 6.1.3.1
Initial Standard Rating Condition A Dehumidification Test), as
enumerated in section 2.2.1(c) of the proposed Appendix B).
In the July 2017 ASHRAE TP RFI, DOE further noted that section
6.1.3.1 of ANSI/AHRI 920-2015 calls for a supplementary heat penalty if
the supply air temperature is less than 70 [deg]F, but the
incorporation of this penalty into the MRE and COP equations is not
clearly described. DOE also noted that it is not clear whether the
ANSI/ASHRAE 198-2013 test method considers this penalty. 82 FR 34427,
34436-34437 (July 25, 2017).
AHRI commented that the supplementary heat penalty should be added
if the minimum 70 [deg]F temperature is not met, and that this value is
added to the measured power input, which is represented as PT in
section 10.6 of ANSI/ASHRAE 198-2013. (AHRI, No. 11 at p. 11) DOE notes
that this clarification is included in section 6.9 of AHRI 920-2020 in
the calculation of MRE70, which incorporates the energy
impact of heating the supply air to 70 [deg]F. As discussed in section
III.B.2 of this NOPR, DOE is proposing to adopt the ISMRE2 metric
specified in section 6.13 of AHRI 920-2020 that does not include the
supplementary heat penalty as the regulated metric for DDX-DOAS, while
the MRE70 (and ISMRE270) metric that incorporates
the supplementary heat penalty may be used for representations. As a
result, the supplementary heat penalty would only be added to the total
power input for the calculation of the optional MRE70
ratings.
With regards to the COP calculation, AHRI commented that the intent
was that the supplementary heat penalty would be added to the numerator
as additional heat capacity and the denominator as additional power
consumed to calculate a COP indicative of running an electric heater to
meet a supply air temperature of 70 [deg]F. (AHRI, No. 11 at p. 13) DOE
notes that this clarification was included in section 6.11.2 of AHRI
920-2020 in the renamed COPISCOP metric, and accordingly, DOE is
proposing to adopt the revised COPISCOP calculation (section 6.11.2 of
AHRI 920-2020), as enumerated in section 2.2.1(c) of the proposed
Appendix B).
2. Determination of Represented Values
a. Basic Model
To determine the energy efficiency of a basic model, DOE's
certification requirements generally require manufacturers to test a
sample of units of that basic model to represent its performance. (10
CFR 429.11) The basic model may include multiple individual models
having similar performance features and characteristics. Typically, DOE
provides a definition of a basic model for each type of covered
equipment. In this NOPR, DOE proposes a definition for DDX-DOAS basic
model derived from the basic model definition for other commercial
packaged air conditioning and heating equipment set forth at 10 CFR
431.92. Specifically, DOE replaced the criterion to have common nominal
cooling capacity with common nominal MRC. DOE is also proposing to
include the common nominal MRC in the definition of a basic model for
small, large and very large air-cooled or water-cooled commercial
package air conditioning and heating equipment, which includes DDX-
DOASes. The proposed definition of basic model of a DDX-DOAS also
specifies that a basic model must include units with similar VERS
equipment. DOE is proposing in this specification to reflect that
ASHRAE Standard 90.1 delineates DDX-DOAS equipment classes, in part,
based on VERS, and the proposed test procedure considers the
conditioning contribution of the VERS equipment.
[[Page 36044]]
DOE is proposing that a basic model for a DDX-DOAS means all units
manufactured by one manufacturer within a single equipment class; with
the same or comparably performing compressor(s), heat exchangers,
ventilation energy recovery system(s) (if present), and air moving
system(s), and with a common ``nominal'' moisture removal capacity.
This proposed definition of a basic model of a DDX-DOAS would be
included in the regulatory text in 10 CFR 431.92.
Issue-9: DOE seeks comment on the proposed definition of basic
model of a DDX-DOAS.
b. Sampling Plan Requirements
DOE is proposing sampling requirements to determine the represented
values for DDX-DOAS (i.e., dehumidification and heating efficiencies
and MRC). More specifically, by proposing to define (at 10 CFR 431.92)
DDX-DOAS as a subset of DX-DOAS, and to define DX-DOAS as a category of
small, large, or very large commercial package air conditioning and
heating equipment, the proposal would apply the same sampling
requirements to DDX-DOASes as applicable to other commercial package
air conditioning and heating equipment under 10 CFR 429.43, Commercial
heating, ventilating, air conditioning (HVAC) equipment.
In response to DOE's request for general comment on issues
associated with adopting the industry test procedures for certain
commercial package air conditioning and heat pump equipment in the July
2017 ASHRAE TP RFI (82 FR 34427, 34445 (July 25, 2017)), Lennox
recommended that DOE harmonize the certification criteria for
commercial HVAC equipment in 10 CFR 429.43 with those for central air
conditioners, a consumer product, in 10 CFR 429.16. In particular,
Lennox stated that commercial equipment currently has a more stringent
confidence limit of 95 percent, but the commenter argued that current
testing technology does not support this level of precision. (Lennox,
No. 8 at p. 6) As DOE is proposing to apply the sampling requirements
of 10 CFR 431.43 to DDX-DOASes, Lennox's comment regarding the
confidence limit for represented values of energy efficiency, energy
consumption, and capacity is relevant to DDX-DOASes.
Other manufacturers did not raise concerns regarding the confidence
limit required for sampling more typical commercial package air
conditioning and heat pump equipment, and Lennox has not provided data
regarding variability of units in production and testing. Absent more
specific information or data regarding the stringency of the confidence
level, DOE is not proposing a change.\33\
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\33\ DOE notes that it has previously requested data regarding
the variability of units of small, large, and very large air-cooled
commercial package air conditioning and heating equipment in
production and testing to enable DOE to review and make any
necessary adjustments to the specified confidence levels. See 80 FR
79655, 79659 (Dec. 23, 2015). However, DOE did not receive any
relevant data in response to that request.
---------------------------------------------------------------------------
Issue-10: DOE requests comment on the sampling plan proposed for
DDX-DOASes. DOE specifically requests information and data regarding
the proposed confidence level and whether variability of testing of
DDX-DOASes would require a less stringent level, and if so, what that
level should be.
c. Multiple Refrigerants
DOE recognizes that some commercial package air conditioning and
heating equipment may be sold with more than one refrigerant option
(e.g., R-410A or R-407C). Typically, manufacturers specify a single
refrigerant in their literature for each unique model, but in its
review, DOE has identified at least one commercial package air
conditioning and heating equipment manufacturer that provides two
refrigerant options under the same model number. The refrigerant chosen
by the customer in the field installation may impact the energy
efficiency of a unit. For this reason, DOE is proposing representation
requirements specific for models approved for use with multiple
refrigerants.
Use of a refrigerant that requires different hardware (such as R-
407C as compared to R-410A) would represent a different basic model,
and according to the current CFR, separate representations of energy
efficiency are required for each basic model. On the other hand, some
refrigerants (such as R-422D and R-427A) would not require different
hardware, and a manufacturer may consider them to be the same basic
model. In the latter case of multiple refrigerant options, DOE proposes
to add a new paragraph at 10 CFR 429.43(a)(3) specifying that a
manufacturer must determine the represented values for that basic model
based on the refrigerant(s)--among all refrigerants listed on the
unit's nameplate--that result in the lowest ISMRE2 and ISCOP2
efficiencies, respectively. For example, the dehumidification
performance metric ISMRE2 must be based on the refrigerant yielding the
lowest ISMRE2, and the heating performance metric ISCOP2 (if the unit
is a heat pump DDX-DOAS) must be based on the refrigerant yielding the
lowest ISCOP2. These represented values would apply to the basic model
for all refrigerants specified by the manufacturer as appropriate for
use, regardless of which one may actually be used in the field, where
only one set of values is reported.
DOE notes that this proposal reflects the proposed definition of
basic model for DDX-DOASes as discussed in section III.B.4.a of this
NOPR. Units within a basic model of DDX-DOAS must have the same or
comparably performing compressor(s), heat exchangers, ventilation
energy recovery system(s) (if present), and air moving system(s), and
with a common ``nominal'' moisture removal capacity.
Issue-11: DOE requests comment on its proposal regarding
representations for models approved for use with multiple refrigerants.
d. Alternative Energy-Efficiency Determination Methods
DOE proposes to allow DDX-DOAS manufacturers to use alternative
energy-efficiency determination methods (AEDMs) for determining the
ISMRE2 and ISCOP2 (if applicable) in accordance with 10 CFR 429.70. By
proposing to define (at 10 CFR 431.92) DDX-DOAS as a subset of DX-DOAS,
and to define DX-DOAS as a category of small, large, or very large
commercial package air conditioning and heating equipment, the
provisions of 10 CFR 429.43 authorizing use of an AEDM for commercial
HVAC equipment would apply to DDX-DOAS. DOE notes that the proposed
requirements for use of AEDMs to determine DDX-DOAS represented values
are consistent with AEDM requirements for all other categories of
commercial package air-conditioning and heating equipment.
DOE proposes to create four validation classes of DDX-DOASes within
the Validation classes table at 10 CFR 429.70(c)(2)(iv): Air-cooled/
air-source and water-cooled/water-source, each with and without VERS.
The separation into air-cooled/air-source and water-cooled/water source
validation classes is the same approach used for other categories of
commercial package air-conditioning and heating equipment. For DDX-
DOASes, the additional class separation by presence of energy recovery
reflects ASHRAE Standard 90.1 delineating equipment classes, in part,
based on the presence of VERS and the significant differences in the
test methods required with energy recovery. These differences in the
test procedures include the potential need for a third test chamber for
the Option 1 approach for testing DDX-DOASes with energy recovery, and
the
[[Page 36045]]
requirement to account for the performance of the energy recovery
device for the Option 2 approach (see section III.B.3.g of this NOPR).
DOE proposes to require testing of two basic models to validate the
AEDMs for each validation class--this is identical to the requirements
for other categories of commercial package air-conditioning and heating
equipment. Finally, DOE proposes to specify in the table at 10 CFR
429.70(c)(5)(vi) a tolerance of 10 percent for DDX-DOAS verification
tests for ISMRE2 and ISCOP2 when comparing test results with certified
ratings. Again, this is identical to the tolerances for ``integrated''
ratings for other categories of commercial package air-conditioning and
heating equipment.
Issue-12: DOE requests comment on its proposals for AEDM
requirements for DDX-DOAS equipment. DOE requests comment specifically
on whether the proposed 10-percent tolerance for comparison of test
results with rated values is appropriate. If the 10-percent tolerance
is not appropriate, DOE requests comment on why it is not appropriate,
as well as comment indicating an appropriate tolerance.
e. Rounding
Sections 6.1.2.1 through 6.1.2.8 of AHRI 920-2020 specify rounding
for DDX-DOAS performance metrics. DOE proposes to adopt these rounding
requirements as part of the DOE test procedure, as enumerated in
section 2.2.1(c)(iv) of the proposed Appendix B.
Issue-13: DOE requests comment on its proposal to adopt the
rounding requirements for key metrics as specified in sections 6.1.2.1
through 6.1.2.8 of AHRI 920-2020.
3. Configuration of Unit Under Test
DOE recognizes that DDX-DOASes are distributed in commerce in a
variety of configurations consisting of different combinations of
components. DOE proposes in section 2.2.1(g) of Appendix B to adopt the
requirements of appendix F to AHRI 920-2020, which includes a list of
components that must be present for testing DDX-DOASes and a list of
components that are optional for testing. Appendix F in AHRI 920-2020
also includes explicit instructions on how representations can be made
for equipment that include these optional components. AHRI 920-2020
specifies the following list of components that must be present for
testing:
Supply air filter(s);
Compressor(s);
Outdoor coil(s) or heat exchanger(s);
Outdoor coil fan(s)/motor(s) (for air-cooled and air-
source systems only);
Conditioning coil(s);
Refrigerant expansion device(s);
Supply/outdoor ventilation fan(s)/motor(s), and
System controls.
AHRI 920-2020 also specifies that for supply air filters, the
filter shall have a ``minimum efficiency reporting value'' (MERV)
specification no less than MERV 8. For individual models that use
filters with efficiency higher than MERV 8 (which generally have higher
pressure drop and could reduce relative tested efficiency), section
F2.4 of AHRI 920-2020 allows manufacturers the option of testing these
individual models as a separate basic model or combined into a basic
model with other individual models that meet the basic model definition
and are tested with a MERV 8 filter. Adopting Appendix F of AHRI 920-
2020 without changes would allow manufacturers to provide efficiency
representations based on either testing option for individual models
that use filters with efficiency higher than MERV 8.
DOE notes that the list of components that are optional for testing
specified in section F2.4 of AHRI 920-2020 includes features that may
reduce tested efficiency but may also in certain applications: (a)
Maintain or improve field efficiency or (b) be required for safety.
Given the potential benefits, DOE does not want to penalize equipment
with such components, because that might disincentivize their adoption.
By proposing to adopt Appendix F of AHRI 920-2020 without changes, the
following instructions from AHRI 920-2020 would specify how to make
representations for individual models of equipment that include these
optional features:
Individual models with features designated as ``optional''
may be represented separately as a unique basic model or certified
within the same basic model as otherwise identical individual models
without the feature pursuant to the definition of ``basic model'' in
Sec. 431.92.
If an otherwise identical model (within the same basic
model) without the feature is distributed in commerce, test the
otherwise identical model.
If an otherwise identical model (within the same basic
model) without the feature is not distributed in commerce, conduct
tests with the feature present but configured and de-activated so as to
minimize (partially or totally) the impact on the results of the test.
Alternatively, the manufacturer may indicate in the supplemental
testing instructions that the test shall be conducted using a
specially-built otherwise identical unit that is not distributed in
commerce and does not have the feature.
This approach ensures that equipment distributed in commerce with
additional components outside the list of required components are still
within the scope of the test procedure. The proposed approach also
provides instruction on how to make representations for all component
combinations (including those with optional components). In addition,
this approach allows manufacturers the flexibility to make
representations of equipment with components designated as ``optional''
based on testing otherwise identical individual models without the
feature.
C. Other Comments
In response to the July 2017 ASHRAE TP RFI, DOE received several
general comments not specific to any one equipment category or test
procedure. This section addresses those comments.
NCI recommended that DOE follow the development of ASHRAE 221P,
``Test Method to Measure and Score the Operating Performance of an
Installed Constant Volume Unitary HVAC System,'' and consider where it
may be appropriately applied within EPCA test procedures. (NCI, No. 4
at pp. 1-2) NCI stated that it has collected data indicating that
typical split systems and packaged units serving residential and small
commercial buildings typically deliver 50 percent to 60 percent of the
rated capacity to the occupied zone, thereby making laboratory tests
unrepresentative of field performance. (Id.)
As noted in section I.A of this document, EPCA prescribes that the
test procedures for commercial package air conditioning and heating
equipment must be those generally accepted industry testing procedures
or rating procedures developed or recognized by industry as referenced
in ASHRAE Standard 90.1. (42 U.S.C. 6314(a)(4)(A)) DOE notes that
ASHRAE Standard 90.1 does not reference ANSI/ASHRAE Standard 221-2020,
``Test Method to Field-Measure and Score the Cooling and Heating
Performance of an Installed Unitary HVAC System'' \34\ (ASHRAE 221-
2020) as the applicable test procedure corresponding to industry
standards. NCI also did not provide data on field performance or any
correlations between field performance and laboratory test performance
for DX-DOASes or DDX-DOASes for DOE to
[[Page 36046]]
consider. Furthermore, ASHRAE 221-2020 does not provide a method to
determine the dehumidification efficiency and heating efficiency of
DDX-DOASes, as AHRI 920-2020 does. As discussed in section II of this
document, DOE is proposing to incorporate by reference AHRI 920-2020
(i.e., the test procedure recognized by ASHRAE Standard 90.1 for DDX-
DOASes) and the relevant industry standards referenced therein,
consistent with EPCA requirements.
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\34\ Available at: webstore.ansi.org/tandards/ASHRAE/ANSIASHRAEStandard2212020 (Last accessed April 19, 2021).
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The CA IOUs commented that while the July 2017 ASHRAE TP RFI
expressed interest in reducing burden to manufacturers, DOE already
took steps to reduce burden by allowing alternative energy efficiency
or energy use determination methods (AEDMs). (CA IOUs, No. 7 at pp. 1-
2) The CA IOUs stated that there are no further opportunities to
streamline test procedures to limit testing burden. (Id.) Additionally,
the CA IOUs emphasized the importance of accurate efficiency ratings
for its incentive programs and customer knowledge, pointing to the
statutory provision that test procedures must produce results that are
representative of the product's energy efficiency. (Id.)
Lennox stated that it generally supports DOE meeting the statutory
requirements to design test procedures to measure energy efficiency
during an average use cycle but requested that DOE also consider
overall impacts to consumers and manufacturers. (Lennox, No. 8 at pp.
1-2) The commenter stated that in commercial applications, predicting
actual energy use from a single metric is difficult and that a metric
better serves as a point of comparison. (Id.) Lennox suggested that DOE
strike a balance between evaluating equipment in a meaningful way
without introducing regulatory burden from overly complex test
procedures or calculations that provide little value to consumers.
(Id.)
In response to the CA IOUs and Lennox, DOE notes that its approach
to test procedures is largely dictated by the requirements of EPCA. As
discussed, EPCA prescribes that the test procedures for commercial
package air conditioning and heating equipment must be those generally
accepted industry testing procedures or rating procedures developed or
recognized by industry as referenced in ASHRAE Standard 90.1. (42
U.S.C. 6314(a)(4)(A)) If such relevant industry test procedure is
amended, DOE must update its test procedure to be consistent with the
amended industry consensus test procedure, unless DOE determines, by
rule published in the Federal Register and supported by clear and
convincing evidence, that the amended test procedure would not meet the
requirements in 42 U.S.C. 6314(a)(2) and (3) related to representative
use and test burden. (42 U.S.C. 6314(a)(4)(B) and (C)) In establishing
or amending its test procedures, DOE must develop test procedures that
are reasonably designed to produce test results which reflect energy
efficiency, energy use, and estimated operating costs of a type of
industrial equipment during a representative average use cycle and that
are not unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)) DOE's
considerations of these requirements in relation to individual test
method issues are discussed within the relevant sections of this NOPR.
The Joint Advocates stated that there are a number of ambiguities
in industry test procedures and that DOE should address these
ambiguities in order to provide a level playing field for manufacturers
and to ensure that any verification or enforcement testing is
consistent with manufacturers' own testing. (Joint Advocates, No. 9 at
p. 2) In the context of a test procedure for DDX-DOASes, DOE addresses
the potential for ambiguity as applicable, in the previous sections of
this document.
D. Test Procedure Costs, Harmonization, and Other Topics
1. Test Procedure Costs and Impact
EPCA requires DOE to adopt test procedures for small, large and
very large commercial package air conditioning and heating equipment
consistent with the amended industry test procedures developed or
recognized AHRI as referenced in ASHRAE Standard 90.1, unless the
Secretary determines that, supported by clear and convincing evidence,
to do so would not meet the requirements for test procedures to be
reasonably designed to produce results that reflect energy efficiency,
energy use, and estimated operating costs during a representative
average use cycle and not be unduly burdensome to conduct. (42 U.S.C.
6314(a)(4)(B)) In this NOPR, DOE proposes to establish a test procedure
for DDX-DOASes, which belong to a category of small, large, and very
large commercial package air conditioning and heating equipment. DOE is
proposing to establish a test procedure that incorporates by reference
the applicable industry consensus test methods (including the energy
efficiency descriptors) and that establishes representation
requirements. DOE has tentatively determined that these proposed new
test procedures would be representative of an average use cycle and
would not be unduly burdensome for manufacturers to conduct. To the
extent that DOE is proposing modifications to the industry consensus
test procedure, DOE has tentatively determined that the proposed
modifications are consistent with the industry consensus standard, and
as explained in the prior sections, they are supported by clear and
convincing evidence, because absent such modifications, the industry
test procedure would not meet the requirements in 42 U.S.C. 6314(a)(2)
and (3) related to representative use and test burden. (42 U.S.C.
6314(a)(4)(B) and (C)). Further, DOE has tentatively determined that
the proposed modifications would be unlikely to significantly increase
burden, given that DOE is referencing the prevailing industry test
procedure. So, presuming widespread usage of that test standard, its
adoption as part of the Federal test procedure would be expected to
result in little additional cost, even with the minor modifications
proposed here. DOE has tentatively determined that the test procedure,
if finalized as proposed, would not require manufacturers to redesign
any of the covered equipment, would not require changes to how the
equipment is manufactured, and would not impact the utility of the
equipment.
When the industry test procedure or rating procedure for a category
of small, large, and very large commercial package air conditioning and
heating equipment recognized in ASHRAE Standard 90.1 is amended, DOE is
required to amend the Federal test procedure for the relevant category
of small, large, and very large commercial package air conditioning and
heating equipment consistent with the industry update, unless DOE
determines by clear and convincing evidence that to do so would result
in a test procedure that does not meet the EPCA requirements regarding
representativeness and testing burden. (42 U.S.C. 6314(a)(4)(B)) As
discussed, ASHRAE Standard 90.1-2016 established energy efficiency
levels for DDX-DOASes (but written as ``DX-DOASes'' in ASHRAE Standard
90.1) as a category of commercial package air conditioning and heating
equipment and recognized ANSI/AHRI 920-2015 as the industry test
procedure for these equipment. Subsequent to the establishment of
standards and a test procedure for DDX-DOASes in ASHRAE Standard 90.1-
2016, ANSI/AHRI 920-2015 was updated. The 2020 version of AHRI 920
(i.e., AHRI 920-2020) is the most recent version of the industry test
procedure for DDX-
[[Page 36047]]
DOASes (still referred to in AHRI 920-2020 as simply ``DX-DOASes'').
DOE is proposing to incorporate by reference the revised industry
test standard, AHRI 920-2020, with certain modifications that are
consistent with the industry test standard. DOE has tentatively
concluded that the proposed test procedure in this NOPR would not add
undue industry test burden, and that the proposed test procedure for
this equipment is consistent with the industry test procedure update.
Further discussion of the cost impacts of the proposed test procedure
are presented in the following paragraphs.
As noted previously, currently DOE does not prescribe test
procedures for DDX-DOASes, and AHRI 920-2020 is the most recent version
of the industry test procedure applicable to DDX-DOASes. DOE has
tentatively determined that the proposal to incorporate by reference
AHRI 920-2020 is consistent with current industry practice, and,
therefore, manufacturers would not be expected to incur any additional
costs if the proposal were finalized. Importantly, the proposals in
this NOPR, if finalized, would not require manufacturers to certify
ratings to DOE. DOE would address certification as part of any
rulemaking to address energy conservation standards for DDX-DOASes.
With that said, DOE is proposing to define ``dehumidifying direct
expansion-dedicated outdoor air system'' (DDX-DOAS) based on the
definition provided in AHRI 920-2020. The differences in the proposed
definition as compared to the definition in AHRI 920-2020 are to
provide clarity and use terminology consistent with DOE's test
procedures for other categories of commercial package air conditioning
and heating equipment.
DOE is proposing to limit the applicability of the proposed test
procedure to DDX-DOASes with any MRC less than 324 lbs. of moisture per
hour, whereas the scope of AHRI 920-2020 is not limited based on MRC.
In a comment provided in response to the July 2017 ASHRAE TP RFI, AHRI
stated that laboratory limitations may limit testing using ANSI/AHRI
920-2015 to 300 lbs. of moisture per hour at Standard Rating Condition
A and to units not physically larger than more typical commercial
package air conditioning equipment with a capacity of 760,000 Btu per
hour. (AHRI, No. 11 at p. 20) As discussed in section III.A.3 of this
document, DOE's proposal to limit the coverage of DDX-DOASes to 324
lbs. of moisture per hour in the DDX-DOAS definition is a direct
conversion from the maximum cooling capacity limit of 760,000 Btu per
hour (which AHRI notes would be the upper limit for laboratory
capabilities), and it is similar to the suggestion made by AHRI. Hence
the definitional modifications to the industry standard will not change
the scope of coverage of the proposed test procedure as compared to the
industry standard, and if made final, would not result in any increase
in test burden as compared to AHRI 920-2020.
AHRI 920-2020 does not explicitly state the amount of external head
pressure to use when testing water-cooled and water-source DDX-DOASes
with integral pumps. As noted, there are a very limited number of DDX-
DOAS models with integral pumps on the market. DOE is proposing to
require such units be tested with an external head pressure equal to 20
-0/+1 feet of water column, which is the same level of external head
pressure used in the calculation of the pump effect for DDX-DOASes
without integral pumps. As such, DOE considers this proposal to be
consistent with industry test procedure because it ensures that
integral pumps are treated in the same way as non-integral pumps, and
as such would not increase testing burden as compared to current
industry practice.
AHRI 920-2020 also does not explicitly provide directions for
setting up the unit's control settings at each Standard Rating
Condition. As discussed in section III.B.3.g of this document, DOE is
proposing a general requirement for all control settings to remain
unchanged for all Standard Rating Conditions once system set up has
been completed, and that component operation shall be controlled by the
unit under test once the provisions for rating requirements are met.
This is likely how DDX-DOASes would be tested as per the existing
instructions in AHRI 920-2020, but DOE is providing the additional
specificity in order to ensure that the results of the testing are
representative, repeatable, and reproducible, and as such would not
increase testing burden as compared to current industry practice.
AHRI 920-2020 incorrectly indicates that Equation 20 should be used
to calculate the degradation coefficient for DDX-DOASes with VERS
(because Equation 21 is indicated to apply for DDX-DOASes with VERS).
This is discussed in further detail in section III.B.3.l.ii of this
document. DOE is proposing to correct this statement to instead use
this equation for DDX-DOASes without VERS, with deactivated VERS, or
with sensible-only VERS tested under Standard Rating Conditions other
than D. DOE considers this proposal to be consistent with the intent of
the industry test procedure and would not increase testing burden as
compared to AHRI 920-2020.
DOE's proposal to provide a definition for ``non-standard low-
static fan motor'' also serves to provide clarity to the instructions
present in AHRI 920-2020 without affecting the scope of coverage or
testing burden. Absent this definition, as discussed in section
III.B.3.l.iii of this document, it is not possible to determine the
appropriate airflow setting procedure in section 6.1.5.2 of AHRI 920-
2020.
AHRI 920-2020 does not provide instruction for testing a DDX-DOAS
for which a manufacturer recommends more than one refrigerant option.
DOE is proposing to require testing of such a unit with each
recommended refrigerant if the different refrigerants require different
hardware. This proposal is consistent with the treatment of basic
models of commercial packaged air conditioners and heating equipment
under 10 CFR 430.92, and, as such, it would be reflective of industry
practice for commercial packaged air conditioner and heating equipment
generally. Therefore, this proposed addition to the procedure laid out
by AHRI 920-2020 would not increase testing burden as compared current
industry practice.
DOE is also proposing sampling requirements for making
representations of ISMRE2 and ISCOP2, as applicable. AHRI 920-2020 does
not contain comparable provisions. The sampling requirements proposed
are consistent with the DOE sampling requirements generally for
commercial packaged air conditioners and heating equipment, and, if
made final, would be reflective of industry practice. Therefore, the
proposed sampling requirements, if made final, would not increase
testing burden as compared to the current industry practice.
Issue-14: DOE requests comment on its understanding of the impact
of the test procedure proposals in this NOPR, specifically DOE's
initial conclusion that manufacturers would not incur any additional
costs due to this proposal, if finalized, compared to current industry
practice, as indicated by AHRI 920-2020.
4. Harmonization With Industry Standards
DOE proposes to incorporate by reference the provisions in AHRI
920-2020, including definitions, test methods, and rating requirements,
with certain modifications previously discussed. Throughout this NOPR,
DOE discusses adopting this most recent
[[Page 36048]]
relevant industry consensus testing standard for DDX-DOAS equipment, as
required in 42 U.S.C. 6314 and discussed in section III.B of this NOPR.
Issue-15: DOE seeks comment on the degree to which the DOE test
procedure should consider and be harmonized further with the most
recent relevant industry consensus testing standards for DDX-DOASes and
whether there could be modifications to the industry test method that
would provide additional benefits to the public. DOE also requests
comment on the benefits and burdens of adopting any industry/voluntary
consensus-based or other appropriate test procedure, without
modification.
5. Other Test Procedure Topics
In addition to the issues identified earlier in this document, DOE
welcomes comment on any other aspect of the proposed test procedures
for DDX-DOASes not already addressed by the specific areas identified
in this document. DOE particularly seeks information that would ensure
that the test procedure measures energy efficiency during a
representative average use cycle, as well as information that would
help DOE create a procedure that is not unduly burdensome to conduct.
E. Compliance Date
EPCA prescribes that, if DOE amends a test procedure, all
representations of energy efficiency and energy use, including those
made in the context of certification and on marketing materials and
product labels, must be made in accordance with that amended test
procedure, beginning 360 days after publication of such a test
procedure final rule in the Federal Register. (42 U.S.C. 6314(d)(1))
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
The Office of Management and Budget (OMB) has determined that this
test procedure rulemaking does not constitute a ``significant
regulatory actions'' under section 3(f) of Executive Order 12866,
``Regulatory Planning and Review,'' 58 FR 51735 (Oct. 4, 1993).
Accordingly, this action was not subject to review under the Executive
Order by the Office of Information and Regulatory Affairs (OIRA) in
OMB.
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires
preparation of an initial regulatory flexibility analysis (``IRFA'')
for any rule that by law must be proposed 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 has made
its procedures and policies available on the Office of the General
Counsel's website at: energy.gov/gc/office-general-counsel. DOE
reviewed this proposed rule under the provisions of the Regulatory
Flexibility Act and the policies and procedures published on February
19, 2003.
The following sections detail DOE's IRFA for this test procedure
rulemaking.
1. Description of Reasons Why Action Is Being Considered
DOE is undertaking this test procedure rulemaking to establish a
DOE test procedure for DDX-DOASes in response to updates to the
relevant industry consensus standard, American Society of Heating,
Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 90.1,
Energy Standard for Buildings Except Low-Rise Residential Buildings,
which, with its 2016 publication, both added efficiency standards and
specified a test procedure for this equipment (i.e., AHRI 920-2015).
Subsequently, the Air-Conditioning, Heating, and Refrigeration
Institute (AHRI) updated its test procedure with the publication of
AHRI 920-2020. The Energy Policy and Conservation Act (EPCA) \35\
requires that each time the test procedure referenced by ASHRAE
Standard 90.1 is updated, DOE must update the Federal test procedure
consistent with the industry update, unless there is clear and
convincing evidence that the update would not be representative of an
average use cycle or would be unduly burdensome to conduct.
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\35\ 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).
---------------------------------------------------------------------------
2. Objectives of, and Legal Basis for, Rule
EPCA, as amended, among other things, authorizes DOE to regulate
the energy efficiency of a number of consumer products and certain
industrial equipment. Title III, Part C \36\ of EPCA, Public Law 94-163
(42 U.S.C. 6311-6317, as codified), added by Public Law 95-619, Title
IV, Sec. 441(a), established the Energy Conservation Program for
Certain Industrial Equipment, which sets forth a variety of provisions
designed to improve energy efficiency. This covered equipment includes
small, large, and very large commercial package air conditioning and
heating equipment. (42 U.S.C. 6311(1)(B)-(D)) DOE has initially
determined that commercial package air conditioning and heating
equipment includes DX-DOASes. As discussed in section I.B of the NOPR
document, DX-DOASes had not previously been addressed in DOE
rulemakings and are not currently subject to Federal test procedures or
energy conservation standards.
---------------------------------------------------------------------------
\36\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
Under EPCA, DOE's energy conservation program consists essentially
of four parts: (1) Testing, (2) labeling, (3) Federal energy
conservation standards, and (4) certification and enforcement
procedures. Relevant provisions of EPCA specifically include
definitions (42 U.S.C. 6311), energy conservation standards (42 U.S.C.
6313), test procedures (42 U.S.C. 6314), labeling provisions (42 U.S.C.
6315), 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(b); 42 U.S.C. 6296), and (2) making representations about the
efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE uses
these test procedures to determine whether the equipment complies with
relevant standards promulgated under EPCA.
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 (b); 42 U.S.C. 6297) DOE may, however, grant waivers
of Federal preemption in limited circumstances 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, the statute also sets forth the criteria and
procedures DOE is required to follow when prescribing or amending test
procedures for covered equipment. Specifically, EPCA requires that any
test procedure prescribed or amended shall be reasonably designed to
produce test results which measure energy
[[Page 36049]]
efficiency, energy use, or estimated annual operating cost of covered
equipment during a representative average use cycle and requires that
test procedures not be unduly burdensome to conduct. (42 U.S.C.
6314(a)(2))
EPCA requires that the test procedures for commercial package air
conditioning and heating equipment be those generally accepted industry
testing procedures or rating procedures developed or recognized by the
Air-Conditioning, Heating, and Refrigeration Institute (AHRI) or by the
American Society of Heating, Refrigerating and Air-Conditioning
Engineers (ASHRAE), as referenced in ASHRAE Standard 90.1, ``Energy
Standard for Buildings Except Low-Rise Residential Buildings'' (ASHRAE
Standard 90.1). (42 U.S.C. 6314(a)(4)(A)) Further, if such an industry
test procedure is amended, DOE must update its test procedure to be
consistent with the amended industry test procedure, unless DOE
determines, by rule published in the Federal Register and supported by
clear and convincing evidence, that such amended test procedure would
not meet the requirements in 42 U.S.C. 6314(a)(2) and (3), related to
representative use and test burden. (42 U.S.C. 6314(a)(4)(B))
EPCA also requires that, at least once every seven years, DOE
evaluate test procedures for each type of covered equipment, including
commercial package air conditioning and heating equipment to determine
whether amended test procedures would more accurately or fully comply
with the requirements for the test procedures not to 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)-(3)) In addition, if DOE determines that a test procedure
amendment is warranted, it 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 in the Federal Register its determination not to amend the
test procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
A test procedure for a subset of DX-DOASes (i.e., DDX-DOASes), was
first specified by ASHRAE Standard 90.1 in the 2016 edition (ASHRAE
Standard 90.1-2016). Pursuant to 42 U.S.C. 6314(a)(4)(B), and following
updates to the relevant test procedures which were referenced in ASHRAE
Standard 90.1, DOE is publishing this NOPR proposing to establish a
test procedure for DDX-DOASes in satisfaction of its aforementioned
obligations under EPCA.
3. Description and Estimate of Small Entities Regulated
For manufacturers of small, large, and very large air-conditioning
and heating equipment (including DDX-DOASes), commercial warm-air
furnaces, and commercial water heaters, the Small Business
Administration (SBA) has set a size threshold which defines those
entities classified as ``small businesses'' for the purposes of the
statute. DOE used the SBA's small business size standards to determine
whether any small entities would be subject to the requirements of this
rule. See 13 CFR part 121. The equipment covered by this rule are
classified under North American Industry Classification System
(``NAICS'') code 333415,\37\ ``Air-Conditioning and Warm Air Heating
Equipment and Commercial and Industrial Refrigeration Equipment
Manufacturing.'' In 13 CFR 121.201, the SBA sets a threshold of 1,250
employees or fewer for an entity to be considered as a small business
for this category.
---------------------------------------------------------------------------
\37\ 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 on April 20, 2021).
---------------------------------------------------------------------------
In reviewing the DDX-DOAS market, DOE used company websites,
marketing research tools, product catalogues, and other public
information to identify companies that manufacture DDX-DOASes. DOE
identified 16 manufacturers of DDX-DOASes affected by this rulemaking.
Out of these 16 manufacturers, DOE determined that three are domestic
small businesses. DOE used subscription-based business information
tools to determine headcount and revenue of the small businesses.
Issue-16: DOE invites comment on the number of domestic small
businesses producing DDX-DOASes for the U.S. market.
4. Description and Estimate of Compliance Requirements
EPCA requires DOE to adopt test procedures for small, large, and
very large commercial package air conditioning and heating equipment
consistent with the amended industry test procedures developed or
recognized by AHRI as referenced in ASHRAE Standard 90.1, unless the
Secretary determines that, supported by clear and convincing evidence,
to do so would not meet the requirements for test procedures to be
reasonably designed to produce results that reflect energy efficiency,
energy use, and estimated operating costs during a representative
average use cycle and not be unduly burdensome to conduct. (42 U.S.C.
6314(a)(4)(B)) In this NOPR, DOE proposes to establish a test procedure
for DDX-DOASes, which belong to a category of small, large, and very
large commercial package air conditioning and heating equipment. DOE is
proposing to establish a test procedure that incorporates by reference
the applicable industry consensus test methods (including the energy
efficiency descriptors) and that establishes representation
requirements. Although AHRI 920-2020 is not yet referenced as the
applicable test procedure in ASHRAE Standard 90.1, it provides revised
test methods that update ANSI/AHRI 920-2015, which is the referenced
industry test standard. For these reasons, DOE has tentatively
concluded that the methods in AHRI 920-2020 reflect the intention for
prevalent industry practice: It is likely that manufacturers will use
AHRI 920-2020 in the future.
In its review of AHRI 920-2020, DOE estimated the cost for third-
party lab testing of basic models to range from $10,000 to $23,500
depending on validation class, equipment capacity, and equipment
configuration. However, manufactures are not required to perform
laboratory testing on all basic models. DOE proposes to allow DDX-DOAS
manufacturers to use alternative energy-efficiency determination
methods (AEDMs) for determining the ISMRE2 and ISCOP2 (if applicable)
in accordance with 10 CFR 429.70. An AEDM is a computer modeling or
mathematical tool that predicts the performance of non-tested basic
models. These computer modeling and mathematical tools, when properly
developed, can provide a relatively straight-forward and reasonably
accurate means to predict the energy usage or efficiency
characteristics of a basic model of a given covered product or
equipment and reduce the burden and cost associated with testing.
DOE researched manufacturer DDX-DOAS offerings and estimated the
cost to rate basic models according to the proposed DOE test procedure
(which is not expected to have any additional cost over AHRI 920-2020
\38\). Using
[[Page 36050]]
information collected on small business equipment offerings and the
upper threshold of third-party testing costs, DOE estimates an average
expense of approximately $200,000 per small manufacturer. These testing
expenses would be less than 1% of revenue for each small business. DOE
tentatively concludes that the estimate costs would not present a
significant burden to small manufacturers.
---------------------------------------------------------------------------
\38\ DOE has tentatively determined that the proposed
modifications to AHRI 920-2020 would be unlikely to significantly
increase burden, given that DOE is referencing the prevailing
industry test procedure. So, presuming widespread usage of AHRI 920-
2020, its adoption as part of the Federal test procedure would be
expected to result in little additional cost, even with the minor
modifications proposed by DOE.
---------------------------------------------------------------------------
The testing of DDX-DOASes would not be required until such time as
DOE establishes DDX-DOAS energy conservation standards and
manufacturers are required to comply with those energy conservation
standards. As such, small manufacturers will have a substantial
timeframe to prepare for the testing detailed in this NOPR.
Additionally, small manufacturers already testing to AHRI 920-2020
would incur no additional costs as a result of this proposed test
procedure.
Issue-17: DOE invites comment on the testing costs and timing of
testing costs described in this IRFA.
5. Duplication, Overlap, and Conflict With Other Rules and Regulations
DOE is not aware of any rules or regulations that duplicate,
overlap, or conflict with the proposed rule being considered in this
action.
6. Significant Alternatives to the Rule
DOE proposes to reduce burden on manufacturers, including small
businesses, by allowing alternative energy efficiency or energy use
determination methods (AEDMs) in lieu of physical testing all basic
models. An AEDM is a computer modeling or mathematical tool that
predicts the performance of non-tested basic models. The use of
computer modeling is more time-efficient than physical testing. Without
AEDMs, the average cost to rate all basic models would exceed $29
million per small manufacturer, as compared to the $200,000 per small
manufacturer in the current proposal.
Additionally, DOE considered alternative test methods and
modifications to the test procedure for DDX-DOASes, and the Department
has tentatively determined that there are no better alternatives than
the modifications and test procedures proposed in this NOPR, in terms
of both meeting the agency's objectives and reducing burden. DOE
examined relevant industry test standards, and the Department
incorporated these standards in the proposed test procedures whenever
appropriate to reduce test burden to manufacturers. Specifically, this
NOPR proposes that DOE establish a test procedure for DDX-DOASes
through incorporation by reference of AHRI 920-2020 with modifications
that are not expected to increase test burden.
In addition, individual manufacturers may petition for a waiver of
the applicable test procedure. (See 10 CFR 431.401.) Also, Section 504
of the Department of Energy Organization Act, 42 U.S.C. 7194, provides
authority for the Secretary to adjust a rule issued under EPCA in order
to prevent ``special hardship, inequity, or unfair distribution of
burdens'' that may be imposed on that manufacturer as a result of such
rule. Manufacturers should refer to 10 CFR part 1003 for additional
details.
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of certain commercial package air condition and
heating equipment 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/industrial equipment, including commercial package air
condition and heating equipment. (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.
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
DOE is analyzing this proposed regulation in accordance with the
National Environmental Policy Act of 1969 (NEPA) and DOE's NEPA
implementing regulations (10 CFR part 1021). DOE anticipates that this
rulemaking qualifies for categorical exclusion A6 because it is a
procedural rulemaking and meets the requirements for application of a
categorical exclusion. 10 CFR part 1021, subpart D, Appendix A, section
A6; See 10 CFR 1021.410. DOE will complete its NEPA review before
issuing the final rule.
E. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 4,
1999), imposes certain requirements on Federal 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 has examined this
proposed rule and has tentatively determined that it would 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 products that are the subject of this
proposed 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
[[Page 36051]]
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 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, the proposed 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 proposed regulatory action likely to result 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 energy.gov/gc/office-general-counsel. DOE examined this proposed
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 proposed rule would 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 proposed regulation
would 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). DOE has
reviewed this proposed 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 proposed 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 proposed significant energy action,
the agency must give a detailed statement of any adverse effects on
energy supply, distribution, or use should the proposal be implemented,
and of reasonable alternatives to the action and their expected
benefits on energy supply, distribution, and use.
The proposed regulatory action to adopt a test procedure for
measuring the energy efficiency of DDX-DOASes 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 proposed
rule authorizes or requires use of commercial standards, the notice of
proposed 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 proposed test procedure for DDX-DOASes incorporate the
following applicable industry consensus standards: AHRI 920-2020, ANSI/
AHRI 1060-2018, ANSI/ASHRAE 37-2009, ANSI/ASHRAE 41.1-2013, ANSI/ASHRAE
41.6-2014, and ANSI/ASHRAE 198-2013. DOE has evaluated these standards
and is unable to conclude whether they fully comply with the
requirements of section 32(b) of the FEAA (i.e., whether they were
developed in a manner that fully provides for public participation,
comment, and review). DOE will consult with both the Attorney General
[[Page 36052]]
and the Chairman of the FTC concerning the impact of these test
procedures on competition, prior to prescribing a final rule.
M. Description of Materials Incorporated by Reference
In this NOPR, DOE proposes to incorporate by reference the
following test standards:
(1) The test standard published by AHRI, titled ``2020 Standard for
Performance Rating of DX-Dedicated Outdoor Air System Units,'' AHRI
Standard 920-2020 (I-P). AHRI Standard 920-2020 (I-P) is an industry-
accepted test procedure for measuring the performance of DX-dedicated
outdoor air system units. AHRI Standard 920-2020 (I-P) is available on
AHRI's website at: www.ahrinet.org/App_Content/ahri/files/STANDARDS/AHRI/AHRI_Standard_920_I-P_2020.pdf.
(2) The test standard published by AHRI, titled ``2018 Standard for
Performance Rating of Air-to-Air Exchangers for Energy Recovery
Ventilation Equipment,'' ANSI/AHRI Standard 1060-2018. ANSI/AHRI
Standard 1060-2018 is an industry-accepted test procedure for measuring
the performance of air-to-air exchangers for energy recovery
ventilation equipment. ANSI/AHRI Standard 1060-2018 is available on
AHRI's website at: www.ahrinet.org/App_Content/ahri/files/STANDARDS/AHRI/AHRI_Standard_1060_I-P_2018.pdf.
(3) The test standard test standard published by ASHRAE, titled
``Methods of Testing for Rating Electrically Driven Unitary Air-
Conditioning and Heat Pump Equipment,'' ANSI/ASHRAE Standard 37-2009.
ANSI/ASHRAE Standard 37-2009 is an industry-accepted test procedure for
measuring the performance of electrically driven unitary air-
conditioning and heat pump equipment. ANSI/ASHRAE Standard 37-2009 is
available on ASHRAE's website (in partnership with Techstreet) at:
www.techstreet.com/ashrae/standards/ashrae-37-2009?product_id=1650947.
(4) The test standard published by ASHRAE, titled ``Standard Method
for Temperature Measurement,'' ANSI/ASHRAE Standard 41.1-2013. ANSI/
AHRAE Standard 41.1-2013 is an industry-accepted test procedure for
measuring temperature. ANSI/ASHRAE Standard 41.1-2013 is available on
ASHRAE's website (in partnership with Techstreet) at:
www.techstreet.com/ashrae/standards/ashrae-41-1-2013?product_id=1853241.
(5) The test standard published by ASHRAE, titled ``Standard Method
for Humidity Measurement,'' ANSI/ASHRAE Standard 41.6-2014. ANSI/AHRAE
Standard 41.6-2014 is an industry-accepted test procedure for measuring
humidity. ANSI/ASHRAE Standard 41.6-2014 is available on ASHRAE's
website (in partnership with Techstreet) at: www.techstreet.com/ashrae/standards/ashrae-41-6-2014?product_id=1881840.
(6) The test standard published by ASHRAE, titled ``Method for Test
for Rating DX-Dedicated Outdoor Air Systems for Moisture Removal
Capacity and Moisture Removal Efficiency,'' ANSI/ASHRAE Standard 198-
2013. ANSI/ASHRAE Standard 198-2013 is an industry-accepted test
procedure for measuring the performance of DX-dedicated outdoor air
system units. ANSI/ASHRAE Standard 198-2013 is available on ASHRAE's
website (in partnership with Techstreet) at: www.techstreet.com/ashrae/standards/ashrae-198-2013?product_id=1852612.
V. Public Participation
A. Participation in the Webinar
The time and date of the webinar are listed in the DATES section at
the beginning of this document. Webinar registration information,
participant instructions, and information about the capabilities
available to webinar participants will be published on DOE's website:
www.energy.gov/eere/buildings/public-meetings-and-comment-deadlines.
Participants are responsible for ensuring their systems are compatible
with the webinar software. Additionally, you may request an in-person
meeting to be held prior to the close of the request period provided in
the DATES section of this document. Requests for an in-person meeting
may be made by contacting Appliance and Equipment Standards Program
staff at (202) 287-1445 or by email:
[email protected].
B. Procedure for Submitting Prepared General Statements for
Distribution
Any person who has an interest in the topics addressed in this
notice, or who is representative of a group or class of persons that
has an interest in these issues, may request an opportunity to make an
oral presentation at the webinar/public meeting. Such persons may
submit requests to speak via email to the Appliance and Equipment
Standards Program at: [email protected]. Persons
who wish to speak should include with their request a computer file in
WordPerfect, Microsoft Word, PDF, or text (ASCII) file format that
briefly describes the nature of their interest in this rulemaking and
the topics they wish to discuss. Such persons should also provide a
daytime telephone number where they can be reached.
Persons requesting to speak should briefly describe the nature of
their interest in this rulemaking and provide a telephone number for
contact. DOE requests persons selected to make an oral presentation to
submit an advance copy of their statements at least two weeks before
the webinar/public meeting. At its discretion, DOE may permit persons
who cannot supply an advance copy of their statement to participate, if
those persons have made advance alternative arrangements with the
Building Technologies Office. As necessary, requests to give an oral
presentation should ask for such alternative arrangements.
C. Conduct of the Webinar
DOE will designate a DOE official to preside at the webinar meeting
and may also use a professional facilitator to aid discussion. The
meeting will not be a judicial or evidentiary-type public hearing, but
DOE will conduct it in accordance with section 336 of EPCA (42 U.S.C.
6306). A court reporter will be present to record the proceedings and
prepare a transcript. DOE reserves the right to schedule the order of
presentations and to establish the procedures governing the conduct of
the webinar/public meeting. There shall not be discussion of
proprietary information, costs or prices, market share, or other
commercial matters regulated by U.S. anti-trust laws. After the
webinar/public meeting and until the end of the comment period,
interested parties may submit further comments on the proceedings and
any aspect of the rulemaking.
The webinar/public meeting will be conducted in an informal,
conference style. DOE will present summaries of comments received
before the webinar/public meeting, allow time for prepared general
statements by participants, and encourage all interested parties to
share their views on issues affecting this rulemaking. Each participant
will be allowed to make a general statement (within time limits
determined by DOE), before the discussion of specific topics. DOE will
permit, as time permits, other participants to comment briefly on any
general statements.
At the end of all prepared statements on a topic, DOE will permit
participants to clarify their statements briefly and comment on
statements made by others. Participants should be prepared to answer
questions by DOE and by other participants concerning these issues.
[[Page 36053]]
DOE representatives may also ask questions of participants concerning
other matters relevant to this rulemaking. The official conducting the
webinar/public meeting will accept additional comments or questions
from those attending, as time permits. The presiding official will
announce any further procedural rules or modification of the above
procedures that may be needed for the proper conduct of the webinar/
public meeting.
A transcript of the webinar/public meeting will be included in the
docket, which can be viewed as described in the Docket section at the
beginning of this NOPR. In addition, any person may buy a copy of the
transcript from the transcribing reporter.
D. Submission of Comments
DOE will accept comments, data, and information regarding this
proposed rule no later than the date provided in the DATES section at
the beginning of this proposed rule.\39\ Interested parties may submit
comments using any of the methods described in the ADDRESSES section at
the beginning of this document.
---------------------------------------------------------------------------
\39\ DOE has historically provided a 75-day comment period for
test procedure NOPRs pursuant to the North American Free Trade
Agreement, U.S.-Canada-Mexico (``NAFTA''), Dec. 17, 1992, 32 I.L.M.
289 (1993); the North American Free Trade Agreement Implementation
Act, Public Law 103-182, 107 Stat. 2057 (1993) (codified as amended
at 10 U.S.C.A. 2576) (1993) (``NAFTA Implementation Act''); and
Executive Order 12889, ``Implementation of the North American Free
Trade Agreement,'' 58 FR 69681 (Dec. 30, 1993). However, on July 1,
2020, the Agreement between the United States of America, the United
Mexican States, and the United Canadian States (``USMCA''), Nov. 30,
2018, 134 Stat. 11 (i.e., the successor to NAFTA), went into effect,
and Congress's action in replacing NAFTA through the USMCA
Implementation Act, 19 U.S.C. 4501 et seq. (2020), implies the
repeal of E.O. 12889 and its 75-day comment period requirement for
technical regulations. Thus, the controlling laws are EPCA and the
USMCA Implementation Act. Consistent with EPCA's public comment
period requirements for consumer products, the USMCA only requires a
minimum comment period of 60 days. Consequently, DOE now provides a
60-day public comment period for test procedure NOPRs.
---------------------------------------------------------------------------
Submitting comments via www.regulations.gov. The
www.regulations.gov web page will require you to provide your name and
contact information. Your contact information will be viewable to DOE
Building Technologies staff only. Your contact information will not be
publicly viewable except for your first and last names, organization
name (if any), and submitter representative name (if any). If your
comment is not processed properly because of technical difficulties,
DOE will use this information to contact you. If DOE cannot read your
comment due to technical difficulties and cannot contact you for
clarification, DOE may not be able to consider your comment.
However, your contact information will be publicly viewable if you
include it in the comment or in any documents attached to your comment.
Any information that you do not want to be publicly viewable should not
be included in your comment, nor in any document attached to your
comment. Persons viewing comments will see only first and last names,
organization names, correspondence containing comments, and any
documents submitted with the comments.
Do not submit to www.regulations.gov information for which
disclosure is restricted by statute, such as trade secrets and
commercial or financial information (hereinafter referred to as
Confidential Business Information (CBI)). Comments submitted through
www.regulations.gov cannot be claimed as CBI. Comments received through
the website will waive any CBI claims for the information submitted.
For information on submitting CBI, see the Confidential Business
Information section.
DOE processes submissions made through www.regulations.gov before
posting. Normally, comments will be posted within a few days of being
submitted. However, if large volumes of comments are being processed
simultaneously, your comment may not be viewable for up to several
weeks. Please keep the comment tracking number that www.regulations.gov
provides after you have successfully uploaded your comment.
Submitting comments via email. Comments and documents submitted via
email also will be posted to www.regulations.gov. If you do not want
your personal contact information to be publicly viewable, do not
include it in your comment or any accompanying documents. Instead,
provide your contact information in a cover letter. Include your first
and last names, email address, telephone number, and optional mailing
address. The cover letter will not be publicly viewable as long as it
does not include any comments.
Include contact information each time you submit comments, data,
documents, and other information to DOE. No telefacsimiles (faxes) will
be accepted.
Comments, data, and other information submitted to DOE
electronically should be provided in PDF (preferred), Microsoft Word or
Excel, WordPerfect, or text (ASCII) file format. Provide documents that
are not secured, written in English, and free of any defects or
viruses. Documents should not contain special characters or any form of
encryption, and, if possible, they should carry the electronic
signature of the author.
Campaign form letters. Please submit campaign form letters by the
originating organization in batches of between 50 to 500 form letters
per PDF or as one form letter with a list of supporters' names compiled
into one or more PDFs. This reduces comment processing and posting
time.
Confidential Business Information. Pursuant to 10 CFR 1004.11, any
person submitting information that he or she believes to be
confidential and exempt by law from public disclosure should submit via
email two well-marked copies: One copy of the document marked
``confidential'' including all the information believed to be
confidential, and one copy of the document marked ``non-confidential''
with the information believed to be confidential deleted. DOE will make
its own determination about the confidential status of the information
and treat it according to its determination.
It is DOE's policy that all comments may be included in the public
docket, without change and as received, including any personal
information provided in the comments (except information deemed to be
exempt from public disclosure).
E. Issues on Which DOE Seeks Comment
Although DOE welcomes comments on any aspect of this proposal, DOE
is particularly interested in receiving comments and views of
interested parties concerning the following issues:
Issue-1: DOE requests comment on the proposed definition for
``direct expansion-dedicated outdoor air system.'' DOE also requests
comment on any additional characteristics not yet considered that could
help to distinguish DX-DOASes from other commercial package air
conditioning and heating equipment.
Issue-2: DOE requests comment on the proposed definition for
``dehumidifying direct expansion-dedicated outdoor air system.''
Specifically, DOE requests comment on the proposed criteria for
distinguishing a ``dehumidifying direct expansion-dedicated outdoor air
system'' from a ``direct expansion-dedicated outdoor air system'' more
generally. DOE also requests comment on any additional characteristics
not yet considered that could help to distinguish DDX-DOASes from DX-
DOASes more generally.
Issue-3: DOE seeks comment on its translation of Btu per hour to
MRC and specifically its proposal to translate the upper capacity limit
for DDX-DOASes such that a model would be considered
[[Page 36054]]
in scope if it has an MRC less than 324 lbs. per hour.
Issue-4: DOE requests comment on its proposal to clarify what terms
are synonymous with DDX-DOAS.
Issue-5: DOE requests comment and data on the development of a
crosswalk from the efficiency levels in ASHRAE Standard 90.1 based on
ANSI/AHRI 920-2015 to efficiency levels based on AHRI 920-2020. DOE is
specifically seeking data on how dehumidification and heating
efficiency ratings for a given DDX-DOAS model are impacted when
measured using AHRI 920-2020 as compared to ANSI/AHRI 920-2015.
Issue-6: DOE requests comment on the terminology DOE proposes to
use for DDX-DOASes, including ``integrated seasonal coefficient of
performance 2, or ISCOP2;'' ``integrated seasonal moisture removal
efficiency 2, or ISMRE2;'' and ``ventilation energy recovery system, or
VERS.''
Issue-7: DOE requests comment on the proposal to require that
water-cooled and water-source DDX-DOASes with integral pumps be set up
with an external pressure rise equal to 20 feet of water column with a
condition tolerance of -0/+1 foot and an operating tolerance of 1 foot.
Issue-8: DOE requests comment on the proposed general control
setting requirement for DDX-DOASes.
Issue-9: DOE is requesting comment on the proposed definition of
``non-standard low-static fan motor'' and whether the proposed
definition reflects stakeholder understanding of the term.
Issue-10: DOE seeks comment on the proposed definition of basic
model of a DDX-DOAS.
Issue-11: DOE requests comment on the sampling plan proposed for
DDX-DOASes. DOE specifically requests information and data regarding
the proposed confidence level and whether variability of testing of
DDX-DOASes would require a less stringent level, and if so, what that
level should be.
Issue-12: DOE requests comment on its proposal regarding
representations for models approved for use with multiple refrigerants.
Issue-13: DOE requests comment on its proposals for AEDM
requirements for DDX-DOAS equipment. DOE requests comment specifically
on whether the proposed 10-percent tolerance for comparison of test
results with rated values is appropriate. If the 10-percent tolerance
is not appropriate, DOE requests comment on why it is not appropriate,
as well as comment indicating an appropriate tolerance.
Issue-14: DOE requests comment on its proposal to adopt the
rounding requirements for key metrics as specified in sections 6.1.2.1
through 6.1.2.8 of AHRI 920-2020.
Issue-15: DOE requests comment on its understanding of the impact
of the test procedure proposals in this NOPR, specifically DOE's
initial conclusion that manufacturers would not incur any additional
costs due to this proposal, if finalized, compared to current industry
practice, as indicated by AHRI 920-2020.
Issue-16: DOE seeks comment on the degree to which the DOE test
procedure should consider and be harmonized further with the most
recent relevant industry consensus testing standards for DDX-DOASes and
whether there could be modifications to the industry test method that
would provide additional benefits to the public. DOE also requests
comment on the benefits and burdens of adopting any industry/voluntary
consensus-based or other appropriate test procedure, without
modification.
Issue-17: DOE invites comment on the number of domestic small
businesses producing DDX-DOASes for the U.S. market.
Issue-18: DOE invites comment on the testing costs and timing of
testing costs described in this IRFA.
VI. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this proposed
rule.
List of Subjects
10 CFR Part 429
Administrative practice and procedure, Confidential business
information, Energy conservation, Household appliances, Imports,
Incorporation by reference, Intergovernmental relations, Reporting and
recordkeeping requirements, Small businesses.
10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Energy conservation, Incorporation by reference, Reporting
and recordkeeping requirements.
Signing Authority
This document of the Department of Energy was signed on June 23,
2021, by Kelly Speakes-Backman, Principal Deputy Assistant Secretary
and 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.
Signed in Washington, DC, on June 23, 2021.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
For the reasons stated in the preamble, DOE is proposing to amend
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. 429.43 by adding paragraph (a)(3) to read as follows:
Sec. 429.43 Commercial heating, ventilating, air conditioning (HVAC)
equipment.
(a) * * *
(3) Refrigerants: For dehumidifying direct expansion-dedicated
outdoor air systems (DDX-DOASes), if a basic model is distributed in
commerce for which the manufacturer specifies the use of more than one
refrigerant option, the ISMRE2 and ISCOP2, as applicable, are
determined for that basic model using the refrigerant that results in
the lowest ISMRE2 and the refrigerant that results in the lowest
ISCOP2, as applicable. For example, the dehumidification performance
metric ISMRE2 must be based on the refrigerant yielding the lowest
ISMRE2, and the heating performance metric ISCOP2 (if the unit is a
heat pump DDX-DOAS) must be based on the refrigerant yielding the
lowest ISCOP2. A refrigerant is considered approved for use if it is
listed on the nameplate of the single package unit or outdoor unit.
Pursuant to the definition of ``basic model'' in Sec. 431.92 of this
chapter, specification of an additional refrigerant option that
requires use of different hardware (i.e., compressors, heat exchangers,
or air moving systems that are not the same or comparably performing),
results in a different basic model.
* * * * *
[[Page 36055]]
0
3. Amend Sec. 429.70 by revising the tables in paragraphs (c)(2)(iv)
and (c)(5)(vi)(B) to read as follows:
Sec. 429.70 Alternative methods for determining energy efficiency and
energy use.
* * * * *
(c) * * *
(2) * * *
(iv) * * *
------------------------------------------------------------------------
Minimum number of distinct models
Validation class that must be tested per AEDM
------------------------------------------------------------------------
Air-Cooled, Split and Packaged Air 2 Basic Models.
Conditioners (ACs) and Heat Pumps
(HPs) less than 65,000 Btu/h
Cooling Capacity (3-Phase).
------------------------------------------------------------------------
(A) Commercial HVAC Validation Classes
------------------------------------------------------------------------
Air-Cooled, Split and Packaged ACs 2 Basic Models.
and HPs greater than or equal to
65,000 Btu/h Cooling Capacity and
Less than 760,000 Btu/h Cooling
Capacity.
Water-Cooled, Split and Packaged ACs 2 Basic Models.
and HPs, All Cooling Capacities.
Evaporatively-Cooled, Split and 2 Basic Models.
Packaged ACs and HPs, All
Capacities.
Water-Source HPs, All Capacities.... 2 Basic Models.
Single Package Vertical ACs and HPs. 2 Basic Models.
Packaged Terminal ACs and HPs....... 2 Basic Models.
Air-Cooled, Variable Refrigerant 2 Basic Models.
Flow ACs and HPs.
Water-Cooled, Variable Refrigerant 2 Basic Models.
Flow ACs and HPs.
Computer Room Air Conditioners, Air 2 Basic Models.
Cooled.
Computer Room Air Conditioners, 2 Basic Models.
Water-Cooled.
Dehumidifying Direct Expansion- 2 Basic Models.
Dedicated Outdoor Air Systems, Air-
cooled or Air-source Heat Pump,
Without Ventilation Energy Recovery
Systems.
Dehumidifying Direct Expansion- 2 Basic Models.
Dedicated Outdoor Air Systems, Air-
cooled or Air-source Heat Pump,
With Ventilation Energy Recovery
Systems.
Dehumidifying Direct Expansion- 2 Basic Models.
Dedicated Outdoor Air Systems,
Water-cooled, Water-source Heat
Pump, or Ground Source Closed-loop
Heat Pump, Without Ventilation
Energy Recovery Systems.
Dehumidifying Direct Expansion- 2 Basic Models.
Dedicated Outdoor Air Systems,
Water-cooled, Water-source Heat
Pump, or Ground Source Closed-loop
Heat Pump, With Ventilation Energy
Recovery Systems.
------------------------------------------------------------------------
(B) Commercial Water Heater Validation Classes
------------------------------------------------------------------------
Gas-fired Water Heaters and Hot 2 Basic Models.
Water Supply Boilers Less than 10
Gallons.
Gas-fired Water Heaters and Hot 2 Basic Models.
Water Supply Boilers Greater than
or Equal to 10 Gallons.
Oil-fired Water Heaters and Hot 2 Basic Models.
Water Supply Boilers Less than 10
Gallons.
Oil-fired Water Heaters and Hot 2 Basic Models.
Water Supply Boilers Greater than
or Equal to 10 Gallons.
Electric Water Heaters.............. 2 Basic Models.
Heat Pump Water Heaters............. 2 Basic Models.
Unfired Hot Water Storage Tanks..... 2 Basic Models.
------------------------------------------------------------------------
(C) Commercial Packaged Boilers Validation Classes
------------------------------------------------------------------------
Gas-fired, Hot Water Only Commercial 2 Basic Models.
Packaged Boilers.
Gas-fired, Steam Only Commercial 2 Basic Models.
Packaged Boilers.
Gas-fired Hot Water/Steam Commercial 2 Basic Models.
Packaged Boilers.
Oil-fired, Hot Water Only Commercial 2 Basic Models.
Packaged Boilers.
Oil-fired, Steam Only Commercial 2 Basic Models.
Packaged Boilers.
Oil-fired Hot Water/Steam Commercial 2 Basic Models.
Packaged Boilers.
------------------------------------------------------------------------
(D) Commercial Furnace Validation Classes
------------------------------------------------------------------------
Gas-fired Furnaces.................. 2 Basic Models.
Oil-fired Furnaces.................. 2 Basic Models.
------------------------------------------------------------------------
(E) Commercial Refrigeration Equipment Validation Classes
------------------------------------------------------------------------
Self-Contained Open Refrigerators... 2 Basic Models.
Self-Contained Open Freezers........ 2 Basic Models.
Remote Condensing Open Refrigerators 2 Basic Models.
Remote Condensing Open Freezers..... 2 Basic Models.
Self-Contained Closed Refrigerators. 2 Basic Models.
Self-Contained Closed Freezers...... 2 Basic Models.
Remote Condensing Closed 2 Basic Models.
Refrigerators.
Remote Condensing Closed Freezers... 2 Basic Models.
------------------------------------------------------------------------
\1\ The minimum number of tests indicated above must be comprised of a
transparent model, a solid model, a vertical model, a semi-vertical
model, a horizontal model, and a service-over-the counter model, as
applicable based on the equipment offering. However, manufacturers do
not need to include all types of these models if it will increase the
minimum number of tests that need to be conducted.
* * * * *
(5) * * *
(vi) * * *
[[Page 36056]]
(B) * * *
------------------------------------------------------------------------
Applicable
Equipment Metric tolerance
------------------------------------------------------------------------
Commercial Packaged Boilers....... Combustion 5% (0.05)
Efficiency. 5% (0.05)
Thermal Efficiency..
Commercial Water Heaters or Hot Thermal Efficiency.. 5% (0.05)
Water Supply Boilers.
Standby Loss........ 10% (0.1)
Unfired Storage Tanks............. R-Value............. 10% (0.1)
Air-Cooled, Split and Packaged ACs Seasonal Energy- 5% (0.05)
and HPs less than 65,000 Btu/h Efficiency Ratio.
Cooling Capacity (3-Phase).
Heating Season 5% (0.05)
Performance Factor.
Energy Efficiency 10% (0.1)
Ratio.
Air-Cooled, Split and Packaged ACs Energy Efficiency 5% (0.05)
and HPs greater than or equal to Ratio.
65,000 Btu/h Cooling Capacity and
Less than 760,000 Btu/h Cooling
Capacity.
Coefficient of 5%
Performance.
Integrated Energy 10% (0.1)
Efficiency Ratio.
Water-Cooled, Split and Packaged Energy Efficiency 5% (0.05)
ACs and HPs, All Cooling Ratio.
Capacities.
Coefficient of 5% (0.05)
Performance.
Integrated Energy 10% (0.1)
Efficiency Ratio.
Evaporatively-Cooled, Split and Energy Efficiency 5% (0.05)
Packaged ACs and HPs, All Ratio.
Capacities.
Coefficient of 5% (0.05)
Performance.
Integrated Energy 10% (0.1)
Efficiency Ratio.
Water-Source HPs, All Capacities.. Energy Efficiency 5% (0.05)
Ratio.
Coefficient of 5% (0.05)
Performance.
Integrated Energy 10% (0.1)
Efficiency Ratio.
Single Package Vertical ACs and Energy Efficiency 5% (0.05)
HPs. Ratio.
Coefficient of 5% (0.05)
Performance.
Packaged Terminal ACs and HPs..... Energy Efficiency 5% (0.05)
Ratio.
Coefficient of 5% (0.05)
Performance.
Variable Refrigerant Flow ACs and Energy Efficiency 5% (0.05)
HPs. Ratio.
Coefficient of 5% (0.05)
Performance.
Integrated Energy 10% (0.1)
Efficiency Ratio.
Computer Room Air Conditioners.... Net Sensible 5% (0.05)
Coefficient of
Performance.
Dehumidifying Direct Expansion- Integrated Seasonal 10% (0.1)
Dedicated Outdoor Air Systems. Coefficient of
Performance 2.
Integrated Seasonal 10% (0.1)
Moisture Removal
Efficiency 2.
Commercial Warm-Air Furnaces...... Thermal Efficiency.. 5% (0.05)
Commercial Refrigeration Equipment Daily Energy 5% (0.05)
Consumption.
------------------------------------------------------------------------
* * * * *
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
4. 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
5. Amend Sec. 431.2 by revising the definition of ``Commercial HVAC &
WH product'' to read as follows:
Sec. 431.2 Definitions.
* * * * *
Commercial HVAC & WH product means any small, large, or very large
commercial package air-conditioning and heating equipment (as defined
in Sec. 431.92), packaged terminal air conditioner (as defined in
Sec. 431.92), packaged terminal heat pump (as defined in Sec.
431.92), single package vertical air conditioner (as defined in Sec.
431.92), single package vertical heat pump (as defined in Sec.
431.92), computer room air conditioner (as defined in Sec. 431.92),
variable refrigerant flow multi-split air conditioner (as defined in
Sec. 431.92), variable refrigerant flow multi-split heat pump (as
defined in Sec. 431.92), direct expansion-dedicated outdoor air system
(as defined in Sec. 431.92), commercial packaged boiler (as defined in
Sec. 431.82), hot water supply boiler (as defined in Sec. 431.102),
commercial warm air furnace (as defined in Sec. 431.72), instantaneous
water heater (as defined in Sec. 431.102), storage water heater (as
defined in Sec. 431.102), or unfired hot water storage tank (as
defined in Sec. 431.102).
* * * * *
0
6. Amend Sec. 431.92 by:
0
a. Revising the definition of ``Basic model''; and
0
b. Adding, in alphabetical order, the definitions for ``Dehumidifying
direct expansion-dedicated outdoor air system, or DDX-DOAS,'' ``Direct
expansion-dedicated outdoor air system, or DX-DOAS,'' ``Integrated
seasonal coefficient of performance 2, or ISCOP2,'' ``Integrated
seasonal moisture removal efficiency 2, or ISMRE2,'' and ``Ventilation
energy recovery system, or VERS''.
The revision and additions read as follows:
Sec. 431.92 Definitions concerning commercial air conditioners and
heat pumps.
* * * * *
Basic model includes:
(1) Computer room air conditioners means all units manufactured by
one manufacturer within a single equipment class, having the same
primary energy source (e.g., electric or gas), and which have the same
or comparably performing compressor(s), heat exchangers, and air moving
system(s) that have a common ``nominal'' cooling capacity.
(2) Dehumidifying direct expansion-dedicated outdoor air system
means all units manufactured by one manufacturer, having the same
primary energy source (e.g., electric or gas), within a single
equipment class; with the same or comparably performing compressor(s),
heat exchangers, ventilation energy recovery system(s) (if
[[Page 36057]]
present), and air moving system(s) that have a common ``nominal''
moisture removal capacity.
(3) Packaged terminal air conditioner (PTAC) or packaged terminal
heat pump (PTHP) means all units manufactured by one manufacturer
within a single equipment class, having the same primary energy source
(e.g., electric or gas), and which have the same or comparable
compressors, same or comparable heat exchangers, and same or comparable
air moving systems that have a cooling capacity within 300 Btu/h of one
another.
(4) Single package vertical units means all units manufactured by
one manufacturer within a single equipment class, having the same
primary energy source (e.g., electric or gas), and which have the same
or comparably performing compressor(s), heat exchangers, and air moving
system(s) that have a rated cooling capacity within 1500 Btu/h of one
another.
(5) Small, large, and very large air-cooled or water-cooled
commercial package air conditioning and heating equipment means all
units manufactured by one manufacturer within a single equipment class,
having the same or comparably performing compressor(s), heat
exchangers, and air moving system(s) that have a common ``nominal''
cooling capacity.
(6) Small, large, and very large water source heat pump means all
units manufactured by one manufacturer within a single equipment class,
having the same primary energy source (e.g., electric or gas), and
which have the same or comparable compressors, same or comparable heat
exchangers, and same or comparable ``nominal'' capacity.
(7) Variable refrigerant flow systems means all units manufactured
by one manufacturer within a single equipment class, having the same
primary energy source (e.g., electric or gas), and which have the same
or comparably performing compressor(s) that have a common ``nominal''
cooling capacity and the same heat rejection medium (e.g., air or
water) (includes VRF water source heat pumps).
* * * * *
Dehumidifying direct expansion-dedicated outdoor air system, or
DDX-DOAS, means a direct expansion-dedicated outdoor air system that is
capable of dehumidifying air to a 55 [deg]F dew point--when operating
under Standard Rating Condition A as specified in Table 4 or Table 5 of
AHRI 920-2020 (incorporated by reference, see Sec. 431.95) with a
barometric pressure of 29.92 in Hg--for any part of the range of
airflow rates advertised in manufacturer materials, and has a moisture
removal capacity of less than 324 lb/h.
Direct expansion-dedicated outdoor air system, or DX-DOAS, means a
category of small, large, or very large commercial package air-
conditioning and heating equipment which is capable of providing
ventilation and conditioning of 100-percent outdoor air or marketed in
materials (including but not limited to, specification sheets, insert
sheets, and online materials) as having such capability.
* * * * *
Integrated seasonal coefficient of performance 2, or ISCOP2, means
a seasonal weighted-average heating efficiency for heat pump dedicated
outdoor air systems, expressed in W/W, as measured according to
appendix B of this subpart.
Integrated seasonal moisture removal efficiency 2, or ISMRE2, means
a seasonal weighted average dehumidification efficiency for dedicated
outdoor air systems, expressed in lbs. of moisture/kWh, as measured
according to appendix B of this subpart.
* * * * *
Ventilation energy recovery system, or VERS, means a system that
pre-conditions outdoor ventilation air entering the equipment through
direct or indirect thermal and/or moisture exchange with the exhaust
air, which is defined as the building air being exhausted to the
outside from the equipment.
* * * * *
0
7. Section 431.95 is amended by:
0
a. Revising paragraph (a) and the introductory text to paragraph (b);
0
b. Redesignating paragraphs (b)(6) and (7) as (b)(8) and (9);
0
c. Adding new paragraphs (b)(6) and (7);
0
d. Revising the introductory text to paragraph (c) and paragraph
(c)(2);
0
e. Redesignating paragraphs (c)(3) and (4) as (c)(5) and (6); and
0
f. Adding new paragraphs (c)(3) and (4), and paragraph (c)(7).
The revisions and additions read as follows:
Sec. 431.95 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, DOE must publish a document in the
Federal Register and the material must be available to the public. All
approved material is available for inspection at the U.S. Department of
Energy, Office of Energy Efficiency and Renewable Energy, Building
Technologies Program, 6th Floor, 950 L'Enfant Plaza SW, Washington, DC
20024, (202) 586-1445, or go to: www.energy.gov/eere/buildings/appliance-and-equipment-standards-program, and may be obtained from the
other sources in this section. It is also available for inspection at
the National Archives and Records Administration (NARA). 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.
(b) AHRI. Air-Conditioning, Heating, and Refrigeration Institute,
2311 Wilson Blvd., Suite 400, Arlington, VA 22201, (703) 524-8800, or
go to: www.ahrinet.org.
* * * * *
(6) AHRI Standard 920-2020 (I-P), (``AHRI 920-2020''), ``2020
Standard for Performance Rating of DX-Dedicated Outdoor Air System
Units,'' approved February 4, 2020, IBR approved for appendix B to this
subpart.
(7) AHRI Standard 1060-2018, (``ANSI/AHRI 1060-2018''), ``2018
Standard for Performance Rating of Air-to-Air Exchangers for Energy
Recovery Ventilation Equipment,'' approved 2018, (ANSI/AHRI 1060-2018),
IBR approved for appendix B to this subpart.
(c) ASHRAE. American Society of Heating, Refrigerating and Air-
Conditioning Engineers, 180 Technology Parkway, Peachtree Corners,
Georgia 30092, (404) 636-8400, or go to: www.ashrae.org.
* * * * *
(2) ANSI/ASHRAE Standard 37-2009, (``ANSI/ASHRAE 37'' or ``ANSI/
ASHRAE 37-2009''), ``Methods of Testing for Rating Electrically Driven
Unitary Air-Conditioning and Heat Pump Equipment,'' ASHRAE approved
June 24, 2009, IBR approved for Sec. 431.96 and appendices A and B to
this subpart.
(3) ANSI/ASHRAE Standard 41.1-2013, (``ANSI/ASHRAE 41.1-2013''),
``Standard Method for Temperature Measurement,'' ANSI approved January
30, 2013, IBR approved for appendix B to this subpart.
(4) ANSI/ASHRAE Standard 41.6-2014, (``ANSI/ASHRAE 41.6-2014''),
``Standard Method for Humidity Measurement,'' ANSI approved July 3,
2014, IBR approved for appendix B to this subpart.
* * * * *
(7) ANSI/ASHRAE Standard 198-2013, (``ANSI/ASHRAE 198-2013''),
[[Page 36058]]
``Method of Test for Rating DX-Dedicated Outdoor Air Systems for
Moisture Removal Capacity and Moisture Removal Efficiency,'' approved
by ANSI on January 30, 2013, IBR approved for appendix B to this
subpart.
* * * * *
0
8. Amend Sec. 431.96 by:
0
a. Revising paragraph (a) and Table 1 in paragraph (b)(2); and
0
b. Designating the table in paragraph (d) as Table 2 to paragraph (d).
The revisions read as follows:
Sec. 431.96 Uniform test method for the measurement of energy
efficiency of commercial air conditioners and heat pumps.
(a) Scope. This section contains test procedures for measuring,
pursuant to EPCA, the energy efficiency of any small, large, or very
large commercial package air-conditioning and heating equipment,
packaged terminal air conditioners and packaged terminal heat pumps,
computer room air conditioners, variable refrigerant flow systems,
single package vertical air conditioners and single package vertical
heat pumps, and dehumidifying direct expansion-dedicated outdoor air
systems.
(b) * * *
(2) * * *
Table 1 to Paragraph (b)--Test Procedures for Commercial Air Conditioners and Heat Pumps
--------------------------------------------------------------------------------------------------------------------------------------------------------
Additional test
Cooling capacity or Use tests, procedure provisions
Equipment type Category moisture removal Energy efficiency conditions, and as indicated in the
capacity descriptor procedures \1\ in listed paragraphs of
this section
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small Commercial Package Air- Air-Cooled, 3-Phase, <65,000 Btu/h......... SEER and HSPF........ AHRI 210/240-2008 Paragraphs (c) and
Conditioning and Heating Equipment. AC and HP. (omit section 6.5). (e).
Air-Cooled AC and HP.. >=65,000 Btu/h and EER, IEER, and COP... Appendix A to this None.
<135,000 Btu/h. subpart.
Water-Cooled and <65,000 Btu/h......... EER.................. AHRI 210/240-2008 Paragraphs (c) and
Evaporatively-Cooled (omit section 6.5). (e).
AC.
>=65,000 Btu/h and EER.................. AHRI 340/360-2007 Paragraphs (c) and
<135,000 Btu/h. (omit section 6.3). (e).
Water-Source HP....... <135,000 Btu/h........ EER and COP.......... ISO Standard 13256-1 Paragraph (e).
(1998).
Large Commercial Package Air- Air-Cooled AC and HP.. >=135,000 Btu/h and EER, IEER and COP.... Appendix A to this None.
Conditioning and Heating Equipment. <240,000 Btu/h. subpart.
Water-Cooled and >=135,000 Btu/h and EER.................. AHRI 340/360-2007 Paragraphs (c) and
Evaporatively-Cooled <240,000 Btu/h. (omit section 6.3). (e).
AC.
Very Large Commercial Package Air- Air-Cooled AC and HP.. >=240,000 Btu/h and EER, IEER and COP.... Appendix A to this None.
Conditioning and Heating Equipment. <760,000 Btu/h. subpart.
Water-Cooled and >=240,000 Btu/h and EER.................. AHRI 340/360-2007 Paragraphs (c) and
Evaporatively-Cooled <760,000 Btu/h. (omit section 6.3). (e).
AC.
Packaged Terminal Air Conditioners AC and HP............. <760,000 Btu/h........ EER and COP.......... Paragraph (g) of this Paragraphs (c), (e),
and Heat Pumps. section. and (g).
Computer Room Air Conditioners..... AC.................... <65,000 Btu/h......... SCOP................. ASHRAE 127-2007 (omit Paragraphs (c) and
section 5.11). (e).
>=65,000 Btu/h and SCOP................. ASHRAE 127-2007 (omit Paragraphs (c) and
<760,000 Btu/h. section 5.11). (e).
Variable Refrigerant Flow Multi- AC.................... <65,000 Btu/h (3- SEER................. AHRI 1230-2010 (omit Paragraphs (c), (d),
split Systems. phase). sections 5.1.2 and (e), and (f).
6.6).
>=65,000 Btu/h and EER.................. AHRI 1230-2010 (omit Paragraphs (c), (d),
<760,000 Btu/h. sections 5.1.2 and (e), and (f).
6.6).
Variable Refrigerant Flow Multi- HP.................... <65,000 Btu/h (3- SEER and HSPF........ AHRI 1230-2010 (omit Paragraphs (c), (d),
split Systems, Air-cooled. phase). sections 5.1.2 and (e), and (f).
6.6).
>=65,000 Btu/h and EER and COP.......... AHRI 1230-2010 (omit Paragraphs (c), (d),
<760,000 Btu/h. sections 5.1.2 and (e), and (f).
6.6).
Variable Refrigerant Flow Multi- HP.................... <760,000 Btu/h........ EER and COP.......... AHRI 1230-2010 (omit Paragraphs (c), (d),
split Systems, Water-source. sections 5.1.2 and (e), and (f).
6.6).
Single Package Vertical Air AC and HP............. <760,000 Btu/h........ EER and COP.......... AHRI 390-2003 (omit Paragraphs (c) and
Conditioners and Single Package section 6.4). (e).
Vertical Heat Pumps.
[[Page 36059]]
Dehumidifying Direct Expansion- All................... <324 lbs. of moisture ISMRE2 and ISCOP2.... Appendix B of this None.
Dedicated Outdoor Air Systems. removal/hr. subpart.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Incorporated by reference; see Sec. 431.95.
\2\ Moisture removal capacity is determined according to appendix B of this subpart.
* * * * *
0
9. Add Appendix B to subpart F of part 431 to read as follows:
Appendix B to Subpart F of Part 431--Uniform Test Method for Measuring
the Energy Consumption of Dehumidifying Direct Expansion-Dedicated
Outdoor Air Systems
Note: Beginning [date 360 days after publication of a test
procedure final rule], representations with respect to energy use or
efficiency of dehumidifying direct expansion-dedicated outdoor air
systems must be based on testing conducted in accordance with this
appendix. Manufacturers may elect to use this appendix early.
1. Referenced materials.
1.1. Incorporation by reference.
DOE incorporated by reference in Sec. 431.95, the entire
standard for AHRI 920-2020, ANSI/AHRI 1060-2018; ANSI/ASHRAE 37-
2009, ANSI/ASHRAE 41.1-2013, ANSI/ASHRAE 41.6-2014, and ANSI/ASHRAE
198-2013. However, only enumerated provisions of AHRI 920-2020,
ANSI/ASHRAE 37-2009, ANSI/ASHRAE 41.6-2014, and ANSI/ASHRAE 198-
2013, as set forth in paragraphs (a) through (d) of this section are
applicable. To the extent there is a conflict between the terms or
provisions of a referenced industry standard and the CFR, the CFR
provisions control.
(a) AHRI 920-2020:
(i) Section 3--Definitions, as specified in section 2.2.1(a) of
this appendix;
(ii) Section 5--Test Requirements, as specified in section
2.2.1(b) of this appendix;
(iii) Section 6--Rating Requirements, as specified in section
2.2.1(c) of this appendix, omitting section 6.1.2 (but retaining
sections 6.1.2.1-6.1.2.8) and 6.6.1;
(iv) Section 11--Symbols and Subscripts, as specified in section
2.2.1(d) of this appendix;
(v) Appendix A--References--Normative, as specified in section
2.2.1(e) of this appendix;
(vi) Appendix C--ANSI/ASHRAE Standard 198 and ANSI/ASHRAE
Standard 37 Additions, Clarifications and Exceptions--Normative, as
specified in section 2.2.1(f) of this appendix, and
(vii) Appendix F--Unit Configuration for Standard Efficiency
Determination--Normative, as specified in section 2.2.1(g) of this
appendix.
(b) ANSI/ASHRAE 37-2009:
(i) Section 5.1--Temperature Measuring Instruments (excluding
sections 5.1.1 and 5.1.2), as specified in sections 2.2.1(b) and (f)
of this appendix;
(ii) Section 5.2--Refrigerant, Liquid, and Barometric Pressure
Measuring Instruments, as specified in section 2.2.1(b) of this
appendix;
(iii) Sections 5.3--Air Differential Pressure and Airflow
Measurements, as specified in section 2.2.1(b) of this appendix;
(iv) Sections 5.5(b)--Volatile Refrigerant Measurement, as
specified in section 2.2.1(b) of this appendix;
(v) Section 6.1--Enthalpy Apparatus (excluding 6.1.1 and 6.1.3
through 6.1.6), as specified in section 2.2.1(b) of this appendix;
(vi) Section 6.2--Nozzle Airflow Measuring Apparatus, as
specified in section 2.2.1(b) of this appendix;
(vii) Section 6.3--Nozzles, as specified in section 2.2.1(b) of
this appendix;
(viii) Section 6.4--External Static Pressure Measurements, as
specified in section 2.2.1(b) of this appendix;
(ix) Section 6.5--Recommended Practices for Static Pressure
Measurements, as specified in section 2.2.1(f) of this appendix;
(x) Section 7.3--Indoor and Outdoor Air Enthalpy Methods, as
specified in section 2.2.1(f) of this appendix;
(xi) Section 7.4--Compressor Calibration Method, as specified in
section 2.2.1(f) of this appendix;
(xii) Section 7.5--Refrigerant Enthalpy Method, as specified in
section 2.2.1(f) of this appendix;
(xiii) Section 7.6--Outdoor Liquid Coil Method, as specified in
section 2.2.1(f) of this appendix;
(xiv) Section 7.7--Airflow Rate Measurement (excluding sections
7.7.1.2, 7.7.3, and 7.7.4), as specified in section 2.2.1(b) of this
appendix;
(xv) Table 1--Applicable Test Methods, as specified in section
2.2.1(f) of this appendix;
(xvi) Section 8.6--Additional Requirements for the Outdoor Air
Enthalpy Method, as specified in section 2.2.1(f) of this appendix;
(xvii) Table 2b--Test Tolerances (I-P Units), as specified in
sections 2.2.1(c) and 2.2(f) of this appendix; and
(xviii) Errata sheet issued on October 3, 2016, as specified in
section 2.2.1(f) of this appendix.
(c) ANSI/ASHRAE 41.6-2014:
(i) Section 4--Classifications, as specified in section 2.2.1(f)
of this appendix;
(ii) Section 5--Requirements, as specified in section 2.2.1(f)
of this appendix;
(iii) Section 6--Instruments and Calibration, as specified in
section 2.2.1(f) of this appendix;
(iv) Section 7.1--Standard Method Using the Cooled-Surface
Condensation Hygrometer as specified in section 2.2.1(f) of this
appendix; and
(v) Section 7.4--Electronic and Other Humidity Instruments. as
specified in section 2.2.1(f) of this appendix.
(d) ANSI/ASHRAE 198-2013:
(i) Section 4.4--Temperature Measuring Instrument, as specified
in section 2.2.1(b) of this appendix;
(ii) Section 4.5--Electrical Instruments, as specified in
section 2.2.1(b) of this appendix;
(iii) Section 4.6--Liquid Flow Measurement, as specified in
section 2.2.1(b) of this appendix;
(iv) Section 4.7--Time and Mass Measurements, as specified in
section 2.2.1(b) of this appendix;
(v) Section 6.1--Test Room Requirements, as specified in section
2.2.1(b) of this appendix;
(vi) Section 6.6--Unit Preparation, as specified in section
2.2.1(b) of this appendix;
(vii) Section 7.1--Preparation of the Test Room(s), as specified
in section 2.2.1(b) of this appendix;
(viii) Section 7.2--Equipment Installation, as specified in
section 2.2.1(b) of this appendix;
(ix) Section 8.2--Equilibrium, as specified in section 2.2.1(b)
of this appendix, and
(x) Section 8.4--Test Duration and Measurement Frequency, as
specified in section 2.2.1(b) of this appendix.
1.2. Informational materials.
DOE refers to the following provision of AHRI 920-2020, for
informational purposes only:
(a) Appendix E--Typical Test Unit Installations--Informative, as
specified in section 2.2.1(g) of this appendix.
(b) Reserved.
2. Test Method.
2.1. Capacity.
Moisture removal capacity (in pounds per hour) and supply
airflow rate (in standard cubic feet per minute) are determined
according to AHRI 920-2020 (incorporated by reference; see Sec.
431.95) as specified in section 2.2 of this appendix.
2.2. Efficiency.
2.2.1. Determine the ISMRE2 for all DDX-DOASes and the ISCOP2
for all heat pump
[[Page 36060]]
DDX-DOASes in accordance with the following sections of AHRI 920-
2020.
(a) Section 3--Definitions, including the references to ANSI/
AHRI 1060-2018 (incorporated by reference; see Sec. 431.95);
(i) Non-standard Low-static Fan Motor. A supply fan motor that
cannot maintain external static pressure as high as specified in
Table 7 of AHRI 920-2020 when operating at a manufacturer-specified
airflow rate and that is distributed in commerce as part of an
individual model within the same basic model of a DDX-DOAS that is
distributed in commerce with a different motor specified for testing
that can maintain the required external static pressure.
(b) Section 5--Test Requirements, including the references to
sections 5.1, 5.2, 5.3, 5.5, 6.1, 6.2, 6.3, 6.4, and 7.7 (not
including sections 7.7.1.2, 7.7.3, and 7.7.4) of ANSI/ASHRAE 37-2009
(incorporated by reference; see Sec. 431.95), and sections 4.4,
4.5, 4.6, 4.7, 5.1, 6.1, 6.6, 7.1, 7.2, 8.2, and 8.4 of ANSI/ASHRAE
198-2013 (incorporated by reference; see Sec. 431.95);
(i) All control settings are to remain unchanged for all
Standard Rating Conditions once system set up has been completed,
except as explicitly allowed or required by AHRI 920-2020 or as
indicated in the supplementary test instructions (STI). Component
operation shall be controlled by the unit under test once the
provisions in section 2.2.1(c) of this appendix are met.
(c) Section 6--Rating Requirements (omitting sections 6.1.2 and
6.6.1), including the references to Table 2b of ANSI/ASHRAE 37-2009,
and ANSI/ASHRAE 198-2013.
(i) For water-cooled DDX-DOASes, the ``Condenser Water Entering
Temperature, Cooling Tower Water'' conditions specified in Table 4
of AHRI 920-2020 shall be used. For water-source heat pump DDX-
DOASes, the ``Water-Source Heat Pumps'' conditions specified in
Table 5 of AHRI 920-2020 shall be used.
(ii) For water-cooled or water-source DDX-DOASes with integral
pumps, set the external head pressure to 20 ft. of water column,
with a -0/+1 ft. condition tolerance and a 1 ft. operating
tolerance.
(iii) When using the degradation coefficient method as specified
in section 6.9.2 of AHRI 920-2020, Equation 20 applies to DDX-DOAS
without VERS, with deactivated VERS (see section 5.4.3 of AHRI 920-
2020), or sensible-only VERS tested under Standard Rating Conditions
other than D.
(iv) Rounding requirements for representations are to be
followed as stated in sections 6.1.2.1 through 6.1.2.8 of AHRI 920-
2020;
(d) Section 11--Symbols and Subscripts, including references to
ANSI/ASHRAE 1060-2018;
(e) Appendix A--References--Normative;
(f) Appendix C--ANSI/ASHRAE 198-2013 and ANSI/ASHRAE 37
Additions, Clarifications and Exceptions--Normative, including
references to sections 5.1, 6.5, 7.3, 7.4, 7.5, 7.6, 8.6, Table 1,
Table 2b, and the errata sheet of ANSI/ASHRAE 37-2009, ANSI/ASHRAE
41.1-2013 (incorporated by reference; see Sec. 431.95), sections 4,
5, 6, 7.1, and 7.4 of ANSI/ASHRAE 41.6-2014 (incorporated by
reference; see Sec. 431.95), and ANSI/ASHRAE 1060-2018;
(g) Appendix E--Typical Test Unit Installations--Informative,
for information only;
(h) Appendix F--Unit Configuration for Standard Efficiency
Determination--Normative.
2.2.2. Optional Representations. Test provisions for the
determination of the metrics indicated in paragraphs (a) through (d)
of this section are optional and are determined according to the
applicable provisions in section 2.2.1 of this appendix. For water-
cooled DDX-DOASes, these optional representations may be determined
using either the ``Condenser Water Entering Temperature, Cooling
Tower'' or the ``Condenser Water Entering Temperature, Chilled
Water'' conditions specified in Table 4 of AHRI 920-2020. For water-
source heat pump DDX-DOASes, these optional representations may be
determined using either the ``Water-Source Heat Pumps'' or ``Water-
Source Heat Pump, Ground-Source Closed Loop'' conditions specified
in Table 5 of AHRI 920-2020. The following metrics in AHRI 920-2020
are optional:
(a) ISMRE70;
(b) COPFull,x:
(c) COPDOAS,x: and
(d) ISMRE2 and ISCOP2 for water-cooled DDX-DOASes using the
``Condenser Water Entering Temperature, Chilled Water'' conditions
specified in Table 4 of AHRI 920-2020 and for water-source heat pump
DDX-DOASes using the ``Water-Source Heat Pump, Ground-Source Closed
Loop'' conditions specified in Table 5 of AHRI 920-2020.
2.3. Synonymous terms.
(a) Any references to Dedicated Outdoor Air System Unit (DOAS
Unit), Dedicated Outdoor Air System (DOAS), and Direct Expansion
Dedicated Outdoor Air System (DX-DOAS) in AHRI 920-2020 and ANSI/
ASHRAE 198-2013 shall be considered synonymous with Dehumidifying
Direct Expansion-Dedicated Outdoor Air System (DDX-DOAS) as defined
in Sec. 431.92.
(b) Any references to energy recovery or energy recovery
ventilator (ERV) in AHRI 920-2020 and ANSI/ASHRAE 198-2013 shall be
considered synonymous with ventilation energy recovery system (VERS)
as defined in Sec. 431.92.
[FR Doc. 2021-13773 Filed 7-6-21; 8:45 am]
BILLING CODE 6450-01-P