Energy Conservation Program: Test Procedure for Water-Source Heat Pumps, 84188-84232 [2023-25921]
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Federal Register / Vol. 88, No. 231 / Monday, December 4, 2023 / Rules and Regulations
FOR FURTHER INFORMATION CONTACT:
DEPARTMENT OF ENERGY
10 CFR Parts 429 and 431
[EERE–2017–BT–TP–0029]
RIN 1904–AE05
Energy Conservation Program: Test
Procedure for Water-Source Heat
Pumps
Office of Energy Efficiency and
Renewable Energy, Department of
Energy.
ACTION: Final rule.
AGENCY:
The U.S. Department of
Energy (‘‘DOE’’) is amending its test
procedure for water-source heat pumps
to expand the scope of applicability of
the test procedure, incorporate by
reference a new industry consensus test
standard for water-source heat pumps,
adopt a seasonal cooling efficiency
metric, and specify more representative
test conditions used for measuring
heating performance. DOE has
determined that the amended test
procedure will produce results that are
more representative of an average use
cycle and be more consistent with
current industry practice without being
unduly burdensome to conduct.
Additionally, DOE is adopting
provisions governing public
representations of efficiency for this
equipment.
DATES: The effective date of this rule is
January 3, 2024. The amendments will
be mandatory for product testing
starting November 29, 2024.
The incorporation by reference of
certain material listed in the rule is
approved by the Director of the Federal
Register on January 3, 2024.
ADDRESSES: The docket, which includes
Federal Register notices, public meeting
attendee lists and transcripts,
comments, and other supporting
documents/materials, is available for
review at www.regulations.gov. All
documents in the docket are listed in
the www.regulations.gov index.
However, not all documents listed in
the index may be publicly available,
such as those containing information
that is exempt from public disclosure.
A link to the docket web page can be
found at www.regulations.gov/docket/
EERE-2017-BT-TP-0029. The docket
web page contains instructions on how
to access all documents, including
public comments, in the docket.
For further information on how to
review the docket contact the Appliance
and Equipment Standards Program staff
at (202) 287–1445 or by email:
ApplianceStandardsQuestions@
ee.doe.gov.
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SUMMARY:
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Mr. Troy Watson, 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: (240) 449–
9387. Email:
ApplianceStandardsQuestions@
ee.doe.gov.
Ms. Kristin Koernig, U.S. Department
of Energy, Office of the General Counsel,
GC–33, 1000 Independence Avenue SW,
Washington, DC 20585–0121.
Telephone: (202) 586–3593. Email:
Kristin.Koernig@hq.doe.gov.
SUPPLEMENTARY INFORMATION: DOE
incorporates by reference the following
material into 10 CFR parts 429 and 431:
AHRI Standard 600–2023 (I–P), 2023
Standard for Performance Rating of
Water/Brine to Air Heat Pump
Equipment, approved September
11, 2023 (‘‘AHRI 600–2023’’).
ANSI/ASHRAE Standard 37–2009,
Methods of Testing for Rating
Electrically Driven Unitary AirConditioning and Heat Pump
Equipment, ASHRAE-approved
June 24, 2009 (‘‘ANSI/ASHRAE 37–
2009’’).
Errata sheet for ANSI/ASHRAE
Standard 37–2009, Methods of
Testing for Rating Electrically
Driven Unitary Air-Conditioning
and Heat Pump Equipment, March
27, 2019.
ISO Standard 13256–1:1998, Watersource heat pumps—Testing and
rating for performance—Part 1:
Water-to-air and brine-to-air heat
pumps, approved 1998 (‘‘ISO
13256–1:1998’’).
Properties of Secondary Working Fluids
for Indirect Systems, including
Section 2.3 Errata Sheet, Melinder,
published 2010 (‘‘Melinder 2010’’).
Copies of AHRI 600–2023 are
available from the Air-Conditioning,
Heating, and Refrigeration Institute
(‘‘AHRI’’), 2311 Wilson Blvd., Suite 400,
Arlington, VA 22201, (703) 524–8800, or
by going to www.ahrinet.org.
Copies of ANSI/ASHRAE 37–2009
and Errata sheet for ANSI/ASHRAE
Standard 37–2009 are available from the
American Society of Heating,
Refrigerating, and Air-Conditioning
Engineers (‘‘ASHRAE’’), 180 Technology
Parkway NW, Peachtree Corners, GA
30092, (404) 636–8400, or by going to
www.ashrae.org. (ASHRAE standards
are co-published with American
National Standards Institute (‘‘ANSI’’)).
Copies of ISO Standard 13256–1:1998
can be obtained from the International
Organization for Standardization
(‘‘ISO’’), Chemin de Blandonnet 8 CP
PO 00000
Frm 00002
Fmt 4701
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401, 1214 Vernier, Geneva, Switzerland,
+41 22 749 01 11, or online at:
www.iso.org/store.html.
Copies of Melinder 2010 are available
from the International Institute of
Refrigeration (‘‘IIR’’), 177 Boulevard
Malesherbes 75017 Paris, France; +33
(0)1 42 27 32 35; www.iifiir.org.
See section IV.N of this document for
further discussion of these standards.
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope of Applicability
1. WSHPs With Cooling Capacity Greater
Than or Equal to 135,000 Btu/h
2. Representations for Residential
Applications
B. Definition
C. Organization of the Amended DOE Test
Procedures
D. Updates to Industry Standards
1. Comments Regarding DOE’s Authority
2. Comments Regarding DOE’s Test
Procedure Development Process
3. Comments Supporting the Adoption of
AHRI 340/360–2022
4. Comments Opposing the Adoption of
AHRI 340/360–2022
5. Comments Encouraging the Adoption of
AHRI 600
6. Finalized DOE Test Procedure
E. Efficiency Metrics
1. IEER
2. ACOP
3. Optional Representations
4. Entering Air Conditions
F. Test Method
1. Airflow and External Static Pressure
2. Capacity Measurement
3. Pump Power Adjustment and Liquid
External Static Pressure
4. Test Liquid and Specific Heat Capacity
5. Liquid Flow Rate
6. Refrigerant Line Losses
7. Airflow Measurement
8. Air Condition Measurement
9. Duct Losses
10. Refrigerant Charging
11. Voltage
12. Non-Standard Low-Static Indoor Fan
Motors
G. Configuration of Unit Under Test
1. Background and Summary
2. General Comments Received
3. Approach for Exclusion of Certain
Components
H. Represented Values and Enforcement
1. Cooling Capacity
2. Enforcement of IEER
I. Test Procedure Costs
J. Effective and Compliance Dates
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866,
13563, and 14094
B. Review Under the Regulatory Flexibility
Act
1. Description and Estimate of Small
Entities Regulated
2. Description and Estimate of Compliance
Requirements
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3. Certification Statement
C. Review Under the Paperwork Reduction
Act of 1995
D. Review Under the National
Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates
Reform Act of 1995
H. Review Under the Treasury and General
Government Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General
Government Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal
Energy Administration Act of 1974
M. Congressional Notification
N. Description of Materials Incorporated by
Reference
V. Approval of the Office of the Secretary
I. Authority and Background
Water-source heat pumps (‘‘WSHPs’’)
are a category of small, large, and very
large commercial package airconditioning and heating equipment,1
which 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);
6313(a)(1)(G)–(I)) DOE’s test procedure
for WSHPs is currently prescribed at
title 10 of the Code of Federal
Regulations (‘‘CFR’’) part 431.96. The
following sections discuss DOE’s
authority to establish and amend a test
procedure for WSHPs and relevant
background information regarding
DOE’s consideration of a test procedure
for this equipment.
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A. Authority
The Energy Policy and Conservation
Act, Public Law 94–163, as amended
(‘‘EPCA’’),2 authorizes DOE to regulate
1 The Energy Policy and Conservation Act, as
amended (‘‘EPCA’’) defines ‘‘commercial package
air conditioning and heating equipment’’ as aircooled, 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))
EPCA further 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); ‘‘large commercial package air
conditioning and heating equipment’’ as
commercial package air conditioning and heating
equipment that is rated at or above 135,000 Btu per
hour and below 240,000 Btu per hour (cooling
capacity); and ‘‘very large commercial package air
conditioning and heating equipment’’ as
commercial package air conditioning and heating
equipment that is rated at or above 240,000 Btu per
hour and below 760,000 Btu per hour (cooling
capacity). (42 U.S.C. 6311(8)(B)–(D))
2 All references to EPCA in this document refer
to the statute as amended through the Energy Act
of 2020, Public Law 116–260 (Dec. 27, 2020), which
reflect the last statutory amendments that impact
Parts A and A–1 of EPCA.
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the energy efficiency of a number of
consumer products and certain
industrial equipment. (42 U.S.C. 6291–
6317) Title III, Part C of EPCA,3 added
by Public Law 95–619, Title IV, section
441(a), established the Energy
Conservation Program for Certain
Industrial Equipment, which sets forth a
variety of provisions designed to
improve energy efficiency. This
equipment includes WSHPs, the subject
of this document. (42 U.S.C. 6311(1)(B)–
(D))
The energy conservation program
under EPCA consists essentially of four
parts: (1) testing, (2) labeling, (3) Federal
energy conservation standards, and (4)
certification and enforcement
procedures. Relevant provisions of
EPCA include definitions (42 U.S.C.
6311), test procedures (42 U.S.C. 6314),
labeling provisions (42 U.S.C. 6315),
energy conservation standards (42
U.S.C. 6313), and the authority to
require information and reports from
manufacturers (42 U.S.C. 6316; 42
U.S.C. 6296).
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 other 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 42 U.S.C. 6316(b); 42 U.S.C.
6297) DOE may, however, grant waivers
of Federal preemption for particular
State laws or regulations, in accordance
with the procedures and other
provisions of EPCA. (42 U.S.C.
6316(b)(2)(D))
Under 42 U.S.C. 6314, EPCA sets forth
the criteria and procedures DOE must
follow when prescribing or amending
test procedures for covered equipment.
EPCA requires that any test procedures
prescribed or amended under this
section must be reasonably designed to
produce test results which reflect energy
efficiency, energy use or estimated
annual operating cost of a given type of
covered equipment during a
representative average use cycle (as
3 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
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determined by the Secretary) 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
90.1, ‘‘Energy Standard for Buildings
Except Low-Rise Residential Buildings’’
(‘‘ASHRAE 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 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 7 years, DOE evaluate test
procedures for each type of covered
equipment, including WSHPs, to
determine whether amended test
procedures would more accurately or
fully comply with the requirements for
the test procedures to not be unduly
burdensome to conduct and be
reasonably designed to produce test
results that reflect energy efficiency,
energy use, and estimated operating
costs during a representative average
use cycle. (42 U.S.C. 6314(a)(1)
In addition, if the Secretary
determines that a test procedure
amendment is warranted, the Secretary
must publish proposed test procedures
in the Federal Register and afford
interested persons an opportunity (of
not less than 45 days’ duration) to
present oral and written data, views,
and arguments on the proposed test
procedures. (42 U.S.C. 6314(b)) If DOE
determines that test procedure revisions
are not appropriate, DOE must publish
in the Federal Register its
determination not to amend the test
procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
DOE undertook this rulemaking in
satisfaction of the 7-year-lookback
obligations under EPCA. (42 U.S.C.
6314(a)(1)). As discussed previously in
this document, WSHPs are a category of
commercial package air conditioning
and heating equipment. EPCA requires
the DOE test procedures for commercial
package air conditioning and heating
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equipment to be the generally accepted
industry testing procedure developed or
recognized by AHRI or by ASHRAE, as
referenced in ASHRAE 90.1. (42 U.S.C.
6314(a)(4)(A)) EPCA further requires
that each time the referenced industry
test procedure is amended in ASHRAE
90.1, DOE must amend its test
procedure to be consistent with the
industry update, unless DOE determines
in a rulemaking that there is clear and
convincing evidence that the updated
update industry test procedure would
not be representative of an average use
cycle or would be unduly burdensome
to conduct. (42 U.S.C. 6314(a)(4)(B)(C))
However, under the 7-year-lookback
obligations, there is no ‘‘clear and
convincing evidence’’ required in EPCA.
Rather, EPCA only requires that DOE
determine whether the amended test
procedure would more accurately or
fully comply with the requirements for
the test procedure to not be unduly
burdensome to conduct and be
reasonably designed to produce test
results that reflect energy efficiency,
energy use, and estimated operating
costs during a representative average
use cycle. (42 U.S.C. 6314(a)(1))
DOE is publishing this final rule in
satisfaction of its statutory obligations
under EPCA. (42 U.S.C. 6314(a)(1)(A))
B. Background
DOE’s existing test procedure for
WSHPs is specified at 10 CFR 431.96
(‘‘Uniform test method for the
measurement of energy efficiency of
commercial air conditioners and heat
pumps’’). The Federal test procedure
currently incorporates by reference
International Organization for
Standardization (‘‘ISO’’) Standard
13256–1 (1998), ‘‘Water-source heat
pumps—Testing and rating for
performance—Part 1: Water-to-air and
brine-to-air heat pumps,’’ (‘‘ISO 13256–
1:1998’’).
DOE initially incorporated ISO
13256–1:1998 as the referenced test
procedure for WSHPs on October 21,
2004 (69 FR 61962), and DOE last
reviewed the test procedure for WSHPs
as part of a final rule for commercial
package air conditioners and heat
pumps published in the Federal
Register on May 16, 2012 (‘‘May 2012
Final Rule’’; 77 FR 28928). In the May
2012 Final Rule, DOE retained the
reference to ISO 13256–1:1998 but
adopted additional provisions for
equipment setup at 10 CFR 431.96(e),
which provide specifications for
addressing key information typically
found in the installation and operation
manuals. 77 FR 28928, 28991.
On June 22, 2018, DOE published a
request for information (‘‘RFI’’) to
collect information and data to consider
amendments to DOE’s test procedure for
WSHPs (‘‘June 2018 RFI’’). 83 FR
29048.4 Subsequently, on August 30,
2022, DOE published a notice of
proposed rulemaking (‘‘NOPR’’) in
which DOE responded to stakeholders’
comments on the June 2018 RFI and
proposed amendments to its test
procedure for WSHPs (‘‘August 2022
NOPR’’) 87 FR 53302. In the August
2022 NOPR, DOE proposed to amend
the test procedures for WSHPs to
incorporate by reference AHRI Standard
340/360–2022 (I–P), ‘‘2022 Standard for
Performance Rating of Commercial and
Industrial Unitary Air-conditioning and
Heat Pump Equipment’’ (‘‘AHRI 340/
360–2022’’) and ANSI/ASHRAE
Standard 37–2009, ‘‘Methods of Testing
for Rating Electrically Driven Unitary
Air-Conditioning and Heat Pump
Equipment’’ (‘‘ANSI/ASHRAE 37–
2009’’). Id. at 87 FR 53348. Specifically,
DOE proposed to implement these
changes by adding new appendices C
and C1 to subpart F of part 431, both
titled ‘‘Uniform Test Method for
Measuring the Energy Consumption of
Water-Source Heat Pumps.’’ (‘‘appendix
C’’ and ‘‘appendix C1,’’ respectively). Id.
at 87 FR 53351–52252. The current DOE
test procedure for WSHPs would be
relocated to appendix C without change,
and the new test procedure adopting
AHRI 340/360–2022 and ANSI/
ASHRAE 37–2009 and any other
amendments would be set forth in
proposed appendix C1 for determining
IEER. Id. at 87 FR 53352–53353. DOE
held a public meeting on September 14,
2022 (‘‘NOPR public meeting’’) to
present the key proposals from the
August 2022 NOPR.
DOE received comments in response
to the August 2022 NOPR from the
interested parties listed in Table I.1.
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TABLE I.1—LIST OF COMMENTERS WITH WRITTEN SUBMISSIONS IN RESPONSE TO THE AUGUST 2022 NOPR
Comment No.
in the docket
Commenter(s)
Reference in this final rule
Commenter type
Air-Conditioning, Heating and Refrigeration Institute ............
Appliance Standards Awareness Project, American Council
for an Energy-Efficient Economy.
Northwest Energy Efficiency Alliance ....................................
New York State Energy Research and Development Authority.
ClimateMaster, Inc .................................................................
WaterFurnace International ...................................................
Enertech Global, LLC ............................................................
Florida Heat Pump Manufacturing ........................................
The Geothermal Exchange Organization ..............................
Madison Indoor Air Quality ....................................................
Trane Technologies ...............................................................
AHRI ......................................
Joint Commenters .................
24
27
Trade Association.
Efficiency Organizations.
NEEA .....................................
NYSERDA .............................
25
21
Efficiency Organization.
State Agency.
ClimateMaster .......................
WaterFurnace ........................
Enertech ................................
FHP .......................................
GeoExchange ........................
MIAQ .....................................
Trane .....................................
22
20
19
26
29
23
28
Manufacturer.
Manufacturer.
Manufacturer.
Manufacturer.
Trade Association.
Manufacturer.
Manufacturer.
A parenthetical reference at the end of
a comment quotation or paraphrase
provides the location of the item in the
public record.5 In addition to the
comments listed in Table I.1, DOE also
received 2 comments from anonymous
individuals, which were considered in
the development of this final rule, but
not cited individually. To the extent
that interested parties have provided
written comments that are substantively
consistent with any oral comments
provided during the NOPR public
meeting, DOE cites the written
comments throughout this final rule.
4 An extension of the comment period for the
June 2018 RFI was published July 9, 2018. 83 FR
31704.
5 The parenthetical reference provides a reference
for information located in the docket of DOE’s
rulemaking to develop an amended test procedure
for WSHPs. (Docket No. EERE–2017–BT–TP–0029,
which is maintained at www.regulations.gov). The
references are arranged as follows: (commenter
name, comment docket ID number, page of that
document).
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Any oral comments provided during the
webinar that are not substantively
addressed by written comments are
summarized and cited separately
throughout this final rule.
In May 2021, ISO published an
updated version of Standard 13256–1,
ISO Standard 13256–1 (2021), ‘‘Watersource heat pumps—Testing and rating
for performance—Part 1: Water-to-air
and brine-to-air heat pumps,’’ (‘‘ISO
13256–1:2021’’). In January 2023,
ASHRAE published ASHRAE 90.1–
2022. ASHRAE 90.1–2022 did not
update the referenced test procedure for
WSHPs.6
On September 11, 2023, AHRI
published a new industry test standard
for WSHPs, titled AHRI Standard 600,
‘‘Standard for Performance Rating of
Water/Brine to Air Heat Pump
Equipment’’ (‘‘AHRI 600–2023’’). DOE
worked with stakeholders (including
WSHP manufacturers and efficiency
advocates) as part of the AHRI
Geothermal and WSHP standards
technical committee (‘‘STC’’) to develop
AHRI 600–2023, which addresses many
of the issues in the current WSHP test
procedure that DOE raised in the August
2022 NOPR. The intent of the
Geothermal and WSHP STC was for
AHRI 600–2023 to be used for testing
WSHPs instead of any versions of ISO
Standards 13256–1.
II. Synopsis of the Final Rule
In this final rule DOE is establishing
new appendices C and C1 to subpart F
of part 431. The current DOE test
procedure for WSHPs is relocated to
appendix C without change. The
amended test procedure for WSHPs is
established in a new appendix C1,
which includes the following amended
test procedure requirements for WSHPs
for measuring the updated efficiency
metrics: (1) integrated energy efficiency
ratio (‘‘IEER’’) for WSHPs using AHRI
600–2023; and (2) applied coefficient of
performance (‘‘ACOP’’) using AHRI
600–2023. Use of the amended test
procedure in appendix C1 will not be
required until such time as compliance
is required with amended energy
conservation standards for WSHPs
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denominated in terms of IEER, should
DOE adopt such standards.
Additionally, DOE is expanding the
scope of the test procedure to include
WSHPs with capacities between 135,000
and 760,000 British thermal units per
hour (‘‘Btu/h’’), as well as specifying the
components that must be present for
testing and amending certain provisions
related to representations and
enforcement in 10 CFR part 429.
As discussed in this final rule, DOE
has concluded that the amended test
procedure in appendix C1
(incorporating by reference the most
recent industry consensus test standard
for WSHPs, AHRI 600–2023) provides
more representative results and more
fully complies with the requirements of
42 U.S.C. 6314(a)(2) than testing with
the current Federal test procedure
(based on ISO 13256–1:1998).
The adopted amendments are
summarized in Table II.1 and compared
to the test procedure provisions in place
prior to the amendment, as well as the
reason for the adopted change.
TABLE II.1—SUMMARY OF CHANGES IN THE AMENDED TEST PROCEDURE
Current DOE test procedure
Amended test procedure
Located in 10 CFR 431.96 ..........................................
Current test procedure moved to appendix C to 10
CFR 431.96 and amended test procedure established in appendix C1 to 10 CFR 431.96.
Expands the scope of the test procedure to additionally include units with a cooling capacity greater than or equal to 135,000 Btu/h and less than
760,000 Btu/h in 10 CFR 431.96.
Incorporates by reference AHRI 600–2023 into appendix C1.
Includes provisions for determining IEER by incorporating by reference AHRI 600–2023 into appendix C1.
Changes the test condition for ACOP to 50 °F, by
incorporating by reference AHRI 600–2023 into
appendix C1.
Includes provisions in 10 CFR 429.43 specific to
WSHPs for determining represented values.
Scope is limited to units with a cooling capacity less
than 135,000 Btu/h.
Incorporates by reference ISO 13256–1:1998 ...........
Includes provisions for determining EER metric .........
Specifies test condition of 68 °F for measuring coefficient of performance (‘‘COP’’).
Does not include WSHP-specific provisions for determination of represented values in 10 CFR 429.43.
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Does not include WSHP-specific enforcement provisions in 10 CFR 429.134.
Attribution
Adopts product-specific enforcement provisions for
WSHPs regarding verification of cooling capacity,
testing of systems with specific components, and
IEER testing conducted by DOE.
Readability of test procedure.
Harmonize with scope of test procedure for water-cooled commercial unitary air conditioners.
Improve representativeness of test
procedure.
Improve representativeness of test
procedure.
Improve representativeness of test
procedure.
Establish WSHP-specific provisions for determination of represented values.
Establish enforcement provisions
for DOE testing of WSHPs.
DOE has determined that the test
procedure in appendix C, as described
in section III of this final rule regarding
the establishment of appendix C, does
not alter the measured efficiency of
WSHPs or require retesting solely as a
result of the establishment of appendix
C. Additionally, DOE has determined
that the establishment of appendix C
will not increase the cost of testing.
DOE has determined that the
amended test procedure adopted in
appendix C1 does alter the measured
efficiency of WSHPs and would increase
the cost of testing relative to the current
Federal test procedure, as discussed
further in section III.I of this document.
However, as stated, use of appendix C1
will not be required until the
compliance date of any amended
standards denominated in terms of
IEER, should DOE adopt such standards.
DOE has also determined that the
amended test procedure will not be
unduly burdensome to conduct.
For units with cooling capacity
greater than or equal to 135,000 Btu/h
and less than 760,000 Btu/h newly
added within scope of the WSHP test
procedure, testing according to the
established test procedure for purposes
of certifications of compliance will not
6 ASHRAE 90.1–2022 lists ANSI/AHRI/ASHRAE
13256–1: 1998 (2021) as the test procedure for
WSHPs. However, DOE believes ASHRAE intended
to include ‘‘2012’’ in the parentheses as that was the
most recent year in which the 1998 version of
13256–1 was redesignated.
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be required until the compliance date of
any energy conservation standards for
such equipment, should DOE adopt
such standards. However, if a
manufacturer chooses to make
representations of the energy efficiency
or energy use of such equipment,
beginning 360 days after publication of
the final rule in the Federal Register,
the manufacturer will be required to
base such representations on the DOE
test procedure. (42 U.S.C. 6314(d)(1))
The effective date for the amended
test procedure adopted in this final rule
is 30 days after publication of this
document in the Federal Register.
Discussion of DOE’s actions are
addressed in detail in section III of this
document.
III. Discussion
A. Scope of Applicability
This rulemaking applies to WSHPs,
which are a category of small, large, and
very large commercial package airconditioning and heating equipment.
(See 42 U.S.C. 6311(1)(B)–(D)) In its
regulations, DOE defines WSHP as ‘‘a
single-phase or three-phase reversecycle heat pump that uses a circulating
water loop as the heat source for heating
and as the heat sink for cooling. The
main components are a compressor,
refrigerant-to-water heat exchanger,
refrigerant-to-air heat exchanger,
refrigerant expansion devices,
refrigerant reversing valve, and indoor
fan. Such equipment includes, but is not
limited to, water-to-air water-loop heat
pumps.’’ 10 CFR 431.92.
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1. WSHPs With a Cooling Capacity
Greater Than or Equal to 135,000
Btu/h
The current Federal WSHP test
procedure and energy conservation
standards apply to WSHPs with a rated
cooling capacity below 135,000 Btu/h.
10 CFR 431.96, Table 1 and 10 CFR
431.97, Table 3. In the August 2022
NOPR, DOE proposed to expand the
scope of applicability of the test
procedure to include WSHPs with a
cooling capacity between 135,000 and
760,000 Btu/h. 87 FR 53302, 53307.
Specifically, DOE proposed to update
Table 1 to 10 CFR 431.96 to include
WSHPs with a cooling capacity greater
than or equal to 135,000 Btu/h and less
than 240,000 Btu/h under Large
Commercial Package Air-Conditioning
and Heating Equipment; and to include
WSHPs with a cooling capacity greater
than or equal to 240,000 Btu/h and less
than 760,000 Btu/h under Very Large
Commercial Package Air-Conditioning
and Heating Equipment. Id. In the
August 2022 NOPR, DOE tentatively
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determined that, based on the presence
on the market of units over 135,000 Btu/
h with efficiency ratings and the
identification of laboratories capable of
testing such units, such testing would
not be unduly burdensome. Id. at 87 FR
53306. Additionally, DOE stated that
expanding the scope of DOE’s test
procedure for WSHPs to include
equipment with a cooling capacity
between 135,000 Btu/h and 760,000
Btu/h would ensure that representations
for all WSHPs are made using the same
test procedure and that ratings for
equipment in this cooling capacity
range are appropriately representative.
Id. at 87 FR 53306–53307. DOE
requested comments on the proposed
expansion of the scope of applicability
of the Federal test procedure to include
WSHPs with a cooling capacity between
135,000 and 760,000 Btu/h. Id. at 87 FR
53307.
In response to the June 2022 NOPR,
some commenters expressed concern
with the proposal to expand the scope
of the test procedure. AHRI commented
that it is concerned with DOE’s proposal
to expand testing coverage and update
test procedures without taking steps to
measure the impact on manufacturers
and third-party test labs. (AHRI, No. 24
at pp. 2–3) AHRI asserted that the
August 2022 NOPR does not show
evidence of DOE’s participation in the
critical consensus process required for
developing test procedures and
improving efficiency for ASHRAE 90.1,
which involves conversations regarding
lab capabilities, product availability,
and product efficiencies. (Id.)
AHRI further commented that the
impact on manufacturers of DOE’s
proposed test coverage expansion has
not been quantified. (Id. at p. 3) AHRI
stated that it expects third-party test
labs will not be able to accommodate
the expanded scope to include
equipment up to 760,000 Btu/h, as such
an expansion of scope would require
test labs to increase their testing
capacity from 3 gallons per minute
(‘‘GPM’’) per ton (‘‘GPM/ton’’) at 50 °F to
nearly 200 GPM. (Id.) AHRI commented
that the additional constraints placed on
test labs would cause delays in testing
other equipment as well as WSHPs. (Id.)
Similarly, ClimateMaster opposed
DOE’s proposal to include WSHP
equipment with capacities greater than
135,000 Btu/h within the scope of the
test procedure due to the cost burden
that ClimateMaster asserted would be
imposed on manufacturers and
consumers. (ClimateMaster, No. 22 at p.
2) ClimateMaster stated that these larger
model sizes account for only 0.4 percent
of its overall market volume from 2019
to 2021. (Id.) ClimateMaster presented
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data showing that adding the highercapacity models to the scope of the test
procedure would increase the
certification cost by $184,000 per year to
accommodate testing and equipment
costs. (Id.) ClimateMaster further
commented that third-party compliance
labs are unable to test equipment above
420,000 Btu/h, which would render
DOE’s proposal to test WSHPs that
reach 760,000 Btu/h impossible. (Id.)
ClimateMaster noted that the increased
cost burden needed to accommodate
such a small percentage of affected
equipment would negatively affect
consumers as well as manufacturers.
(Id.) ClimateMaster recommended that
DOE maintain the scope of applicability
of the Federal test procedure to only
include WSHPs with cooling capacity
below 135,000 Btu/h. (Id. at p. 3)
FHP commented that its main concern
regarding DOE’s proposal to expand the
scope of applicability is lab availability.
(FHP, No. 26 at p. 2) FHP stated that it
has found only a limited supply of
WSHP testing facilities, none of which
have a capacity to test equipment over
480,000 Btu/h. (Id.) FHP recommended
that DOE provide a list of testing
facilities for WSHPs with a cooling
capacity greater than 135,000 Btu/h,
stating that multiple testing facilities
must be available to ensure that an
increased demand for large unit testing
does not also cause spikes in testing
costs due to supply and demand
pressures. (Id.) FHP further commented
that WSHPs with capacities above
135,000 Btu/h account for less than 1
percent of the market share. (Id.)
MIAQ commented that it is concerned
DOE has not quantified the impact on
manufacturers and third-party labs of
expanding the scope of coverage to
larger equipment. (MIAQ, No. 23 at p.
3) MIAQ stated that conversations
regarding lab capabilities and product
availability and efficiency occur during
the consensus process required for
developing test procedures in ASHRAE
90.1. (Id.) MIAQ stated that the water
volume required for testing larger
capacities up to 760,000 Btu/h may
limit testing. (Id.) More specifically,
MIAQ stated that testing a 760,000 Btu/
h WSHP would require approximately
200 GPM of 50 °F water, which MIAQ
stated would require large chillers to
maintain the water at the correct
temperature. (Id.) MIAQ also noted that
due to the increased need for larger
spaces capable of testing such
equipment, there could be bottlenecks at
third-party test labs, which also test
other categories of commercial package
air conditioning and heating equipment.
(Id.)
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WaterFurnace stated that there are no
known WSHP products with a cooling
capacity above approximately 360,000
Btu/h nor any test facilities capable of
testing such WSHPs at the required
conditions for IEER. (WaterFurnace, No.
20 at p. 6) WaterFurnace commented
that DOE did not justify regulating this
larger equipment and that doing so
would be a burden on the industry and
testing facilities. (Id.)
Other commenters supported the
proposal to expand the scope of the
WSHP test procedure. The Joint
Commenters, NEEA, and NYSERDA
supported DOE’s proposal to include
WSHPs with cooling capacities between
135,000 and 760,000 Btu/h in the scope
of the test procedure. (Joint
Commenters, No. 27 at p. 1; NEEA, No.
25 at p. 2; NYSERDA, No. 21 at p. 2)
The Joint Commenters stated that they
believe it is important that equipment in
this capacity range be testing using a
standardized test procedure and that
expanding the scope of the test
procedure would bring it into alignment
with test procedures for other
commercial package air-conditioning
and heating equipment. (Joint
Commenters, No. 27 at p. 1)
NEEA commented that, while this
size range may account for relatively
few annual sales, expanding the test
procedure to larger capacity equipment
would ensure that large equipment is
fairly rated and regulated and held to
the same standards as smaller
equipment of the same type. (NEEA, No.
25 at p. 2)
NYSERDA asserted that expanding
the scope is a feasible and necessary
change to ensure that WSHPs of varying
sizes are consistently tested according to
industry standards, which will
demonstrate to customers that WSHPs—
especially geothermal WSHPs—are
reliable and thus enable WSHP market
growth. (NYSERDA, No. 21 at p. 2)
As discussed in the August 2022
NOPR, DOE has identified numerous
model lines of WSHPs with a cooling
capacity over 135,000 Btu/h from a wide
variety of manufacturers. 87 FR 53302,
53306. The manufacturer literature for
all identified model lines includes
efficiency representations that are
explicitly based on ISO 13256–1:1998,
the current industry standard,
indicating efficiency representations can
be made for these models using an
industry consensus test procedure for
WSHPs. Id.
In response to comments from AHRI,
Climate Master, and WaterFurnace, as
discussed in the August 2022 NOPR,
DOE is aware of several independent
test labs that have the capability to test
WSHPs with a cooling capacity over
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135,000 Btu/h. Id. DOE conducted
investigative testing on multiple WSHP
models with a cooling capacity over
135,000 Btu/h at one such independent
test lab and did not encounter any
difficulties specific to units in this
capacity range. Id. Regarding comments
by ClimateMaster and FHP stating that
test labs cannot test units greater than
420,000 Btu/h and 480,000 Btu/h,
respectively, comments submitted by
WaterFurnace indicate that the largest
models currently available on the
market are 360,000 Btu/h, which DOE
research corroborates. As such, any
capacity limitations for testing as
asserted by ClimateMaster and FHP
would not impact any models currently
on the market.
Further, DOE notes that AHRI 600–
2023 includes provisions for testing
units with capacities over 135,000 Btu/
h. Both ASHRAE 90.1 and DOE
regulations cover other categories of
commercial air conditioning and
heating equipment, including watercooled commercial unitary air
conditioners (‘‘WCUACs’’), with a
cooling capacity up to 760,000 Btu/h.
As discussed in the August 2022 NOPR,
DOE has determined that testing WSHPs
with a cooling capacity over 135,000
Btu/h would be of comparable burden to
testing other commercial air
conditioning and heating equipment of
similar capacity, such as WCUACs. Id.
Regarding comments on the potential
burden of testing such units, EPCA does
not require DOE to consider only
burden-reducing options, but rather
requires only that the test procedure
must not be unduly burdensome to
conduct. Expanding the scope of the test
procedure to include larger equipment
would not necessitate certification
unless DOE were to establish standards
for such equipment. Until such a time,
an expansion of scope for the test
procedure would require only that if
manufacturers choose to make optional
representations of efficiency for WSHPs
with a cooling capacity over 135,000
Btu/h, that such optional
representations be made in accordance
with the DOE test procedure. Further,
DOE notes that representations for
WSHPs can be made either based on
testing (in accordance with 10 CFR
429.43(a)(1)) or based on alternative
efficiency determination methods
(‘‘AEDMs’’) (in accordance with 10 CFR
429.43(a)(2)). 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 means to
predict the energy usage or efficiency
characteristics of a basic model of a
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84193
given covered product or equipment
and reduce the burden and cost
associated with testing. Whereas DOE
requires at least two units to be tested
per basic model when represented
values are determined through testing,
DOE requires each AEDM to be
validated by tests of only two WSHP
basic models of any capacity (in
accordance with 10 CFR 429.70(c)(2)).
Based on DOE’s observation of the
prevalence of use of AEDMs for WSHP
and similar equipment for which energy
conservation standards currently apply
(i.e., for equipment with a cooling
capacity no greater than 135,000 Btu/h),
DOE expects that representations of
efficiency could be determined through
the use of AEDMs for the majority of
models with a cooling capacity over
135,000 Btu/h. As such, DOE expects an
expansion of scope for the DOE test
procedure to include equipment with a
cooling capacity over 135,000 Btu/h
would not necessitate the testing of
many such larger units. Therefore,
testing would not be as burdensome as
noted by commenters.
Based on the presence on the market
of units over 135,000 Btu/h, the
identification of laboratories capable of
testing such units, DOE’s observation
that representations of efficiency for
such equipment are currently being
made, and the inclusion of units over
135,000 Btu/h within the scope of the
most recent industry consensus test
standard for WSHPs (AHRI 600–2023),
DOE has determined that testing units
with a cooling capacity over 135,000
Btu/h is feasible and would not be
unduly burdensome. As discussed,
expanding the scope of DOE’s test
procedure for WSHPs to include
equipment with a cooling capacity
between 135,000 Btu/h and 760,000
Btu/h would ensure that representations
for all WSHPs are made using the same
test procedure and that ratings for
equipment in this cooling capacity
range are appropriately representative.
For the reasons discussed in the
proceeding paragraphs and in the
August 2022 NOPR, DOE is expanding
the scope of applicability of the WSHP
test procedure to include WSHPs with
a cooling capacity between 135,000 and
760,000 Btu/h consistent with the scope
of AHRI 600–2023. Specifically, DOE is
updating Table 1 to 10 CFR 431.96 to
include WSHPs with a cooling capacity
greater than or equal to 135,000 Btu/h
and less than 240,000 Btu/h under Large
Commercial Package Air-Conditioning
and Heating Equipment and to include
WSHPs with a cooling capacity greater
than or equal to 240,000 Btu/h and less
than 760,000 Btu/h under Very Large
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Commercial Package Air-Conditioning
and Heating Equipment.
As previously discussed, DOE does
not currently specify energy
conservation standards for WSHPs with
a cooling capacity over 135,000 Btu/h.
DOE would consider any future
standards applicable to WSHPs over
135,000 Btu/h in a separate energy
conservation standards rulemaking.
Manufacturers of WSHPs with a cooling
capacity over 135,000 Btu/h would not
be required to test WSHPs with a
cooling capacity over 135,000 Btu/h
until such time as compliance with
standards for this equipment were
required, should DOE adopt such
standards. DOE notes, however, that
beginning 360 days after this final rule
publishes in the Federal Register, any
voluntary representations with respect
to energy use or efficiency must be
based on the test procedure in appendix
C, and any voluntary representations of
IEER or ACOP must be based on the test
procedure in appendix C1.
ddrumheller on DSK120RN23PROD with RULES2
2. Representations for Residential
Applications
Sections 6.5 and 6.6 of AHRI 600–
2023 state that provisions for
determination of residential cooling
capacity and efficiency are to be added
in a future revision. In the August 2022
NOPR, DOE proposed to allow optional
energy efficiency ratio (‘‘EER’’) and COP
representations at the full-load and partload EWT conditions specified in Table
1 of ISO 13256–1:1998 per the DOE test
procedure proposed in appendix C1. 87
FR 53302, 53313. DOE notes that the
residential representations discussed in
AHRI 600–2023 are separate from the
proposed optional representations from
the August 2022 NOPR, as test
provisions in AHRI 600–2023 specify
separate air and liquid external static
pressures to be used during testing to
develop ratings for residential
applications. However, the residential
representations have not yet been fully
developed for WSHPs, as indicated in
sections 6.5 and 6.6 of AHRI 600–2023.
Therefore, DOE is not adding any
provisions regarding residential
representations in this final rule but will
continue to work with the AHRI 600
committee to develop such provisions.
B. Definition
As discussed, WSHPs are a category
of commercial package air-conditioning
and heating equipment. The current
definition for ‘‘water-source heat pump’’
does not explicitly state that it is
‘‘commercial package air-conditioning
and heating equipment.’’ This is
inconsistent with the definitions of most
other categories of commercial package
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air-conditioning and heating equipment
(e.g., computer room air conditioner,
single package vertical air conditioner,
variable refrigerant flow multi-split air
conditioner). See 10 CFR 431.92.
To provide consistency with other
definitions of specific categories of
commercial package air-conditioning
and heating equipment, DOE proposed
in the August 2022 NOPR to amend the
definition of ‘‘water-source heat pump’’
to explicitly indicate that WSHPs are a
category of commercial package airconditioning and heating equipment. 87
FR 53302, 53307. This proposed
clarification to the ‘‘water-source heat
pump’’ definition would not change the
scope of equipment covered by the
definition.
In addition, the current definition for
WSHPs lists the main components of a
WSHP and it includes ‘‘indoor fan’’ on
that list. See 10 CFR 431.92. DOE
discussed in the August 2022 NOPR that
it has identified coil-only WSHPs on the
market that rely on a separately
installed furnace or modular blower for
indoor air movement. 87 FR 53302,
53307. To clarify that coil-only WSHPs
are covered under the WSHP definition,
DOE proposed to amend the WSHP
definition to make clear that an indoor
fan is not an included component for
coil-only WSHPs. Id. Specifically, DOE
proposed to include the parenthesized
statement ‘‘except that coil-only units
do not include an indoor fan’’ in the
sentence listing the main components in
the proposed WSHP definition. Id.
DOE requested comment on the
proposed change to the definition of
WSHP to explicitly indicate that WSHP
is a category of commercial package airconditioning and heating equipment
and to clarify that the presence of an
indoor fan does not apply to coil-only
units. Id.
ClimateMaster generally agreed with
DOE’s proposed definition of WSHP,
but requested clarity on what
constitutes a commercial system.
(ClimateMaster, No. 22 at p. 3)
ClimateMaster commented that other
industry test programs clearly
demarcate the difference between
systems through listed capacity. (Id.)
ClimateMaster noted that the current
definition includes only packaged
systems but that DOE’s proposed
amendments in the August 2022 NOPR
specified procedures for testing split
systems. (Id.) ClimateMaster stated that
it is not able to determine with the
current definition what exact products
would fall under the certification
program and how DOE would enforce
which products are covered by the
applicable standards. (Id.)
ClimateMaster also stated that there
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were non-reversible WSHP products
that operate as either cooling only units
or utilize a hydronic coil that are not
covered by the current definition.
ClimateMaster stated that provisions
should be made for this equipment type.
(Id.)
WaterFurnace questioned whether it
would be necessary to change the
definition of WSHP if DOE were to
maintain the method of test based on
ISO 13256 and AHRI 600.
(WaterFurnace, No. 20 at p. 6)
WaterFurnace recommended using the
term ‘‘heat pump’’ in lieu of ‘‘air
conditioner and heating equipment,’’
which WaterFurnace asserted is
technically inaccurate. (Id.)
Regarding ClimateMaster’s request for
clarity regarding the definition, DOE
notes that all products that meet the
WSHP definition, with sizes less than
760,000 Btu/h cooling capacity (see
discussion in section III.A of this final
rule), would be considered a WSHP,
regardless of whether the models are
marketed and distributed in commerce
for commercial or residential
applications. The definition of WSHPs
includes both single-package and splitsystem equipment.
Regarding WaterFurnace’s comment
on whether it would be necessary to
change the definition of WSHP if DOE
were to maintain the method of test
based on ISO 13256 and AHRI 600, the
DOE definition of WSHP serves to
specify models that are within the scope
of coverage of DOE’s regulations and is
independent of the test procedure being
used for WSHPs. DOE also notes in
response to WaterFurnace’s comment
that the definition of WSHP already
uses the term ‘‘heat pump’’ to define
WSHP and that the term ‘‘commercial
package air-conditioning and heating
equipment’’ is being added to the
definition only to indicate the larger
type of equipment, as defined in the
EPCA, of which WSHPs are a category.
Regarding ClimateMaster’s comment
that the current definition does not
cover units that are not reversible, DOE
considers water-source heat pumps to
include only models with reverse-cycle
heating; therefore, DOE is not removing
the ‘‘reverse-cycle’’ provision from the
WSHP definition.
For the reasons discussed, DOE is
adopting an amended definition of
WSHP that is identical to the definition
proposed in the August 2022 NOPR, as
follows:
Water-source heat pump means
commercial package air-conditioning
and heating equipment that is a singlephase or three-phase reverse-cycle heat
pump that uses a circulating water loop
as the heat source for heating and as the
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heat sink for cooling. The main
components are a compressor,
refrigerant-to-water heat exchanger,
refrigerant-to-air heat exchanger,
refrigerant expansion devices,
refrigerant reversing valve, and indoor
fan (except that coil-only units do not
include an indoor fan). Such equipment
includes, but is not limited to, water-toair water-loop heat pumps.
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C. Organization of the Amended DOE
Test Procedures
In this final rule, DOE is relocating
and centralizing the current test
procedure for WSHPs to a new
appendix C to subpart F of part 431 and
establishing an amended test procedure
for WSHPs in a new appendix C1 to
subpart F of part 431. Appendix C
maintains the substance of the current
test procedure and continues to
reference ISO 13256–1:1998 and
provide for determining EER and COP.
Appendix C also includes the additional
test provisions for equipment set-up
currently codified at 10 CFR 431.96(e).
As discussed, WSHPs are required to be
tested according to appendix C until
such time as compliance is required
with an amended energy conservation
standard based on the amended test
procedure in appendix C1, should DOE
adopt such a standard.
DOE is also establishing an amended
test procedure for WSHPs in a new
appendix C1 to subpart F of part 431
that includes provisions for determining
IEER and ACOP by incorporating by
reference AHRI 600–2023, as discussed
further throughout this document.
WSHPs are not required to be tested
according to appendix C1 until such
time as compliance is required with an
amended energy conservation standard
denominated in terms of the IEER
metric, should DOE adopt such a
standard; although, any voluntary
representations of IEER prior to the
compliance date of any such standard
must be based on testing according to
appendix C1.
D. Updates to Industry Standards
As noted in section I.B. of this
document, the DOE test procedure
currently incorporates by reference ISO
13256–1:1998 and includes additional
provisions for equipment set-up at 10
CFR 431.96(e), which provide
specifications for addressing key
information typically found in the
installation and operation manuals. In
the August 2022 NOPR, DOE proposed
to adopt an amended test procedure for
WSHPs in a new appendix C1 that
would incorporate by reference AHRI
340/360–2022 for measuring efficiency
using IEER. 87 FR 53302, 53311.
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Because AHRI 340/360–2022 references
ANSI/ASHRAE 37–2009 for test
provisions, DOE also proposed to
incorporate by reference relevant
sections of ANSI/ASHRAE 37–2009 in
its amended test procedure for WSHPs.
Id. at 87 FR 53312. Compared to the
current test procedure, the key
substantive changes that would result
from DOE adopting the proposed test
procedure included the following:
(1) A new energy efficiency
descriptor, IEER, which incorporates
part-load cooling performance;
(2) Modified test conditions for
determining COP;
(3) Minimum external static pressure
(‘‘ESP’’) requirements, instructions for
setting airflow and ESP, and tolerances
for airflow and ESP, and
(4) Specified liquid ESP requirements
for units with integral pumps and a
method to account for total pumping
effect for units without integral pumps.
Id. at 87 FR 53305.
In response to this proposal, DOE
received multiple comments
(summarized in the following subsections) urging DOE not to incorporate
by reference AHRI 340/360–2022 as the
test procedure for WSHPs, to continue
to collaborate with industry on
finalizing AHRI 600, and to instead
adopt the revised industry test standard
resulting from work on AHRI 600. As
previously noted, after publication of
the August 2022 NOPR, DOE worked
with the AHRI Geothermal and WSHP
STC to develop a revised version of
AHRI 600 (AHRI 600–2023) to address
the issues DOE raised in the August
2022 NOPR. As discussed further
throughout this section, AHRI 600–2023
includes a method to determine IEER for
WSHPs similar to that proposed in the
August 2022 NOPR and addresses many
of the concerns expressed by
commenters in response to the August
2022 NOPR. As discussed, AHRI 600–
2023 is intended to serve as the primary
industry test procedure for WSHPs
going forward and it does not reference
any versions of ISO Standard 13256–1.
Instead, AHRI 600–2023 references
ANSI/ASHRAE 37–2009 and includes
sufficient provisions for testing WSHPs
that references to test provisions in ISO
Standard 13256–1 or AHRI 340/360–
2022 are not needed.
As discussed further throughout this
section, in this final rule, DOE is
adopting an amended test procedure
that incorporates by reference AHRI
600–2023, with minor differences as
explained further throughout the
following sections of this document.
In the following sections, DOE
summarizes comments received in
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response to the August 2022 NOPR with
regard to industry standards.
1. Comments Regarding DOE’s
Authority
As discussed previously in this
document, with respect to small, large,
and very large commercial package air
conditioning and heating equipment (of
which WSHPs are a category), EPCA
directs that when the generally accepted
industry testing procedures or rating
procedures developed or recognized by
AHRI or by ASHRAE, as referenced in
ASHRAE 90.1, are amended, the
Secretary shall amend the DOE test
procedure consistent with the amended
industry test procedure or rating
procedure unless the Secretary
determines, by clear and convincing
evidence, that to do so would not meet
the requirements for test procedures to
produce results representative of an
average use cycle and is not unduly
burdensome to conduct. (42 U.S.C.
6314(a)(4)(A)–(B))
In response to the August 2022 NOPR,
AHRI, MIAQ, and WaterFurnace
expressed concern with DOE’s proposal
to adopt a test procedure different from
the industry standard (i.e., ISO 13256–
1:1998 and the not yet published AHRI
600 standard), and the procedure cited
in ASHRAE 90.1. (AHRI, No. 24 at pp.
1–2; MIAQ, No. 23 at pp. 1–2;
WaterFurnace, No. 20 at p. 1) AHRI,
MIAQ, and WaterFurnace noted that
EPCA explicitly directs DOE to adopt
the industry consensus test procedure
cited in ASHRAE 90.1 and asserted that
EPCA precludes DOE from adopting as
a national standard a wholly different
test procedure from that cited in
ASHRAE 90.1. (Id.) These commenters
urged DOE to adopt a revised test
method only after it has been published
by AHRI and adopted by ASHRAE in
ASHRAE 90.1. (Id.)
MIAQ asserted further that EPCA
requires DOE to justify by clear and
convincing evidence each amendment
or difference between AHRI 340/360–
2022 and ISO 13256–1:1998. (MIAQ,
No. 23 at p. 2) MIAQ commented that
DOE has determined in past
rulemakings that ISO 13256–1 is cost
effective and representative of energy
use. (Id.) MIAQ stated that any
deviation from ASHRAE 90.1 requires
quantification of the burden and that
only modifications that reduce testing
burden on manufacturers can be
considered. (Id. at p. 3)
AHRI and MIAQ commented that
DOE and outside stakeholders have
been developing a consensus-based
revision to the test procedure for
commercial packaged air conditioners
and heat pumps (‘‘CUAC/HPs’’). (AHRI,
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No. 24 at p. 2; MIAQ, No. 23 at p. 2)
AHRI and MIAQ further stated that after
AHRI 600 has been finalized and
adopted, AHRI will introduce the new
test procedure to ASHRAE 90.1 to begin
the procedural process for updates.
(AHRI, No. 24 at p. 3; MIAQ, No. 23 at
p. 2) AHRI and MIAQ commented that
waiting to harmonize standards would
establish consistent energy efficiency
levels and design requirements between
industry and Federal requirements, as
well as comparable metrics and scope.
(AHRI, No. 24 at p. 3; MIAQ, No. 23 at
pp. 2–3) AHRI and MIAQ recommended
that DOE continue to work with AHRI
and other stakeholders to finalize AHRI
600 and support a proposed amendment
to ASHRAE 90.1, which DOE could
adopt as the national test procedure
during the next rulemaking. (AHRI, No.
24 at p. 4; MIAQ, No. 23 at pp. 3, 9)
ClimateMaster commented that DOE
has not followed a cooperative approach
to improve the test methods as proposed
in the August 2022 NOPR.
(ClimateMaster, No. 22 at p. 1)
ClimateMaster asserted that this seems
to violate EPCA, which requires DOE to
adopt the test procedure cited in
ASHRAE 90.1. (Id.)
With regard to comments asserting
that DOE does not have the authority to
adopt a test procedure prior to its
inclusion in ASHRAE 90.1, EPCA
provides DOE with authority to adopt
an amended test procedure in
satisfaction of EPCA’s 7-year-lookback
review requirement for test procedures.
(42 U.S.C. 6314(a)(1)(A)). Under its 7year-lookback review, DOE must ensure
that test procedures established are
reasonably designed to produce test
results which reflect energy efficiency,
energy use, and estimated operating
costs during a representative average
use cycle and are not unduly
burdensome to conduct. (42 U.S.C.
6314(a)(2)) During its 7-year lookback
review, DOE is directed by EPCA to
evaluate whether an amended test
procedure would more accurately or
fully comply with those requirements,
and if DOE determines an amended test
procedure would do so, then DOE is
required to prescribe such test
procedures for the equipment class. (42
U.S.C. 6314(a)(1)(A)) It is important to
note that under the 7-year lookback DOE
does not need clear and convincing
evidence that an amended test
procedure would more accurately or
fully comply with EPCA’s requirements.
(Id.) Rather, DOE must show that the
amended test procedure is reasonably
designed to produce test results which
reflect energy efficiency, energy use,
and estimated operating costs during a
representative average use cycle and are
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not unduly burdensome to conduct. (42
U.S.C. 6314(a)(2)) For example, a test
procedure referenced by ASHRAE 90.1
may not be reasonably representative
because more representative test
procedures are available. And a test
procedure that was reasonably
representative in the past may become
unreasonably representative when
newly available test procedures allow
for better, more complete
measurements. DOE’s 7-year-lookback
review under EPCA ensures that DOE is
not bound to an industry test procedure
that has not been updated and is no
longer representative of current
equipment.
DOE notes that submitted comments
from AHRI, WaterFurnace,
ClimateMaster, and MIAQ do not
mention DOE’s 7-year-lookback review
and therefore only engaged with the
review process under 42 U.S.C.
6314(a)(4)(A). AHRI stated in its written
comment that DOE is mandated to adopt
an industry test procedure only after
that test procedure is adopted in
ASHRAE 90.1 but identified no such
mandate within the statute itself. It is
important to note that the 7-yearlookback review language at issue here
was added to EPCA in EISA 2007, well
after the relevant ASHRAE 90.1 test
procedure language was added in 1992.
(Compare Sec. 302 of EISA 2007, Pub.
L. 110–140, 121 STAT. 1552 (Dec. 19,
2007) with Sec. 121 of the Energy Policy
Act of 1992, Pub. L. 106–486, 106
STAT. 2808 (Oct. 24, 1992)). Therefore,
the most natural reading of the two
provisions together is that Congress
intended to add the 7-year-lookback
review to those triggers for review of test
procedures that already existed. The
language of the 7-year-lookback review
applies generally to all covered
equipment. Rather than restrict DOE to
an outdated test procedure in the
manner the industry commenters
suggest, EPCA instead compels DOE to
use due diligence to review the totality
of relevant and available information
before settling on appropriate energy
conservation standards and test
procedures.
As a result, it is appropriate for DOE
to consider in its 7-year-lookback
whether amendments to the test
procedure would more accurately
produce test results which reflect energy
efficiency, energy use, and estimated
operating costs during a representative
average use cycle and would not be
unduly burdensome to conduct even
without an update to AHSRAE 90–1.
DOE finds here that the test procedure
provided in the updated industry
consensus test standard for WSHPs
(AHRI 600–2023), and therefore the test
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procedure specified in the regulatory
text of this final rule, is more
representative without incurring undue
burden, as discussed below, thereby
satisfying EPCA’s requirements.
DOE acknowledges that DOE has
previously stated that it will only
consider an update to ASHRAE 90.1
that modifies the referenced industry
test procedure to be a trigger under that
provision of the statute, as opposed to
an update of just the industry test
procedure itself. (See e.g., 86 FR 35668,
35676 (July 7, 2021)). DOE stands by
that position regarding what constitutes
a triggering event in the context of
ASHRAE equipment and does not
consider the provisions in 42 U.S.C.
6314(a)(4) to have been triggered.
However, that does not preclude DOE
from considering an amended test
procedure when reviewing DOE’s test
procedures under EPCA’s 7-yearlookback provision. Not only does DOE
have discretion to do so, but it has a
statutory duty to do so, to ensure that
its test procedures produce results that
are representative of an average use
cycle and are not unduly burdensome to
conduct.
DOE has determined that the test
procedure adopted in this final rule for
WSHPs would improve the
representativeness of the current
Federal test procedure for WSHPs and
would not be unduly burdensome.
Specifically, DOE has concluded that
testing WSHPs in accordance with AHRI
600–2023 would provide more
representative results and more fully
comply with the requirements of
paragraph (2) of 42 U.S.C. 6314(a) than
testing in accordance with the currently
referenced standard ISO 13256–1:1998,
as discussed in more detail in section
III.D.6 of this final rule. And while clear
and convincing evidence is not needed
when amending a test procedure under
the 7-year-lookback, DOE finds that the
test procedure amendments adopted
here are supported by clear and
convincing evidence as outlined in this
final rule. DOE discusses the specific
test procedure updates included in
appendix C1, resulting from the
incorporation by reference of AHRI 600–
2023, in sections III.E and III.F of this
final rule. Therefore, DOE is adopting an
amended test procedure for WSHPs that
incorporates by reference AHRI 600–
2023, with minor deviations. With
regard to the assertion by AHRI and
MIAQ that any deviation from ASHRAE
90.1 requires quantification of the
burden, and MIAQ’s assertion that only
modifications that reduce testing burden
on manufacturers can be considered,
DOE does not agree that EPCA requires
DOE to consider only deviations that
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would reduce burden. Rather, EPCA
requires only that DOE ensure that test
procedures established are not unduly
burdensome to conduct. (42 U.S.C.
6314(a)(2))
With regard to the assertion by AHRI
and MIAQ that EPCA requires DOE to
justify by clear and convincing evidence
each amendment or difference from the
industry test procedure referenced by
ASHRAE 90.1, DOE does not agree that
EPCA requires such a line-by-line
assessment of an amended test
procedure. First, as stated previously,
there is no requirement for clear and
convincing evidence in EPCA for a test
procedure amendment under the 7-yearlookback. Additionally, if DOE were
amending a test procedure pursuant to
the ASHRAE trigger, EPCA requires
only that DOE shall amend the test
procedure for the product as necessary
to be consistent with the amended
industry test procedure or rating
procedure unless it determines,
supported by clear and convincing
evidence, that to do so would not meet
the requirements of EPCA (42 U.S.C.
6314 (a)(4)(B)). If DOE makes such a
determination, DOE may establish an
amended test procedure, but there is no
requirement for DOE to show, by clear
and convincing evidence, that DOE’s
amended test procedure is reasonably
designed to produce test results which
reflect energy efficiency, energy use,
and estimated operating costs during a
representative average use cycle and are
not unduly burdensome to conduct.
(See 42 U.S.C. 6314(a)(2)). Additionally,
if DOE does not make such a
determination, there is no requirement
that DOE show, by clear and convincing
evidence, that an amended test
procedure, which is consistent with the
industry test procedure, is reasonably
designed to produce test results which
reflect energy efficiency, energy use,
and estimated operating costs during a
representative average use cycle and are
not unduly burdensome to conduct.
2. Comments Regarding DOE’s Test
Procedure Development Process
In response to the June 2022 NOPR,
DOE received comments regarding its
rulemaking development process. AHRI
recommended that DOE follow a
transparent, cooperative, or consensusbased regulatory development process.
(AHRI, No. 24 at p. 4) AHRI commented
that, in the past, DOE has had difficulty
duplicating test results without the help
and guidance of manufacturers and
AHRI testing facilities and that the
complex controls and operational
characteristics of WSHP equipment
require manufacturer and testing facility
experience to test properly. (Id.) AHRI
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acknowledged that DOE has tested 15
units from the WSHP industry but
stated that DOE did not release the data
and results of the testing. (Id.) AHRI
expressed further concern that the
testing cited in the August 2022 NOPR
was not shared with the relevant AHRI
committee and requested that DOE
share the results of its findings with
stakeholders in order to allow for
validation and review. (Id. at pp. 2, 4)
AHRI recommended that DOE work
with industry on finalizing AHRI 600,
conduct any necessary testing or
calculations to develop a document
agreed upon by DOE and relevant
stakeholders, and follow the proper
procedures to introduce the finalized
test procedure and updated efficiency
standards in ASHRAE 90.1. (Id.) AHRI
commented that it will support the
necessary updates to the Federal
procedure and metrics after DOE takes
the aforementioned steps. (Id.)
ClimateMaster commented that DOE
did not follow a cooperative process to
improve the test methods for WSHPs
and that neither AHRI nor the WSHP
industry was consulted in a working
group setting with other stakeholders,
which was inconsistent with past and
current industry approaches.
(ClimateMaster, No. 22 at p. 1)
WaterFurnace commented that it
believed a more transparent and
consensus-based development process
is warranted before DOE implements
new WSHP test procedures and that
DOE should seek industry and AHRI
input in order to validate and review the
testing results. (WaterFurnace, No. 20 p.
2) WaterFurnace recommended that
DOE implement an Appliance
Standards and Rulemaking Federal
Advisory Committee (‘‘ASRAC’’)
Working Group for all future
undertakings to propose substantial
changes in regulatory policy so as to
work out complex issues in a common
forum with industry and AHRI. (Id.)
With respect to the comments from
AHRI, ClimateMaster, and
WaterFurnace, DOE notes that it may
establish a negotiated rulemaking
working group under ASRAC in
accordance with the Federal Advisory
Committee Act (‘‘FACA’’) and the
Negotiated Rulemaking Act (‘‘NRA’’) (5
U.S.C. 561–570, Pub. L. 104–320) to
negotiate proposed test procedures and
amended energy conservation standards
if DOE determines that the use of the
negotiated rulemaking process is in the
public interest according to the
requirements of FACA and in a manner
consistent with the requirements of the
NRA. However, in this rulemaking, DOE
is following the traditional rulemaking
notice-and-comment process.
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DOE recognizes the benefits of
developing test procedures through a
consensus-based process and notes that
DOE has participated in the AHRI
process and has worked with the AHRI
Geothermal and WSHP STC in
developing AHRI 600–2023, which is
incorporated by reference in this final
rule. As noted in the August 2022
NOPR, DOE has participated in AHRI
committee meetings working to develop
AHRI 600 since 2019. See 87 FR 53302,
53308–53309. In particular, DOE
brought up many of the concerns raised
in August 2022 NOPR in ISO 13256–1
and AHRI 600 meetings for several years
prior to the publication of the August
2022 NOPR, but the committees
declined to address these issues in the
draft industry test procedures at that
time. At the time of drafting of the
August 2022 NOPR, AHRI 600 was still
in development and had not yet
published. In the August 2022 NOPR,
DOE outlined its understanding that the
intent of AHRI 600 would be to provide
a method for calculation of IEER for
WSHPs based on testing conducted
according to ISO 13256–1:1998. Id. at 87
FR 53309. In the August 2022 NOPR,
DOE tentatively concluded that the
general methodology in AHRI 600 for
determining IEER is appropriate. Id.
However, DOE identified several aspects
of the methodology that warrant further
modifications. Id. In the August 2022
NOPR, DOE noted that it could not
speculate as to the substantive outputs
of the ISO 13256–1 National deviation
and the AHRI 600 committee’s efforts.
Id. Consistent with DOE’s procedure for
notice-and-comment rulemakings, DOE
also conducted the NOPR public
meeting that provided opportunity for
stakeholders to provide feedback on
DOE’s proposals. The feedback DOE
received in both NOPR public meeting
comments and written comments was
considered in subsequent AHRI 600
committee meetings and drafting of this
final rule.
Since the publication of the August
2022 NOPR, DOE continued to work
with industry in AHRI 600 committee,
as recommended by commenters, to
address the test procedure concerns
DOE raised in the August 2022 NOPR
with the intent that a revised industry
test procedure specific to WSHPs could
be adopted in a final rule. Rather than
continue to simultaneously modify and
maintain ISO 13256–1 and AHRI–600,
the committee members voted to merge
them into a comprehensive unified test
procedure, AHRI 600. More specifically,
the methodology specified in ISO
13256–1 has been incorporated into
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AHRI 600–2023. Therefore, AHRI 600–
2023 does not reference ISO 13256–1.
Regarding AHRI’s comment about
sharing data, DOE presented the results
of its testing in the August 2022 NOPR.
Id. at 87 FR 53314–53317. Based on
participation in AHRI 600 committee
meetings following the August 2022
NOPR, additional data from DOE’s
investigative testing was not needed for
the committee to reach resolution on the
content of AHRI 600–2023.
On September 11, 2023, AHRI 600–
2023 was published. DOE notes that the
statutory deadline for publishing a test
procedure final rule for WSHPs was
May 16, 2019. (42 U.S.C. 6314(a)(1))
Given EPCA’s statutory requirement to
review the appropriate test procedures
for WSHPs every seven years, DOE has
concluded that it would be neither
appropriate nor permissible to delay the
current rulemaking for the WSHP test
procedure until after ASHRAE 90.1
adopts AHRI 600–2023 as the test
procedure for WSHPs. To avoid any
further delay, DOE is adopting a test
procedure for WSHPs that incorporates
by reference AHRI 600–2023, with
minor deviations.
3. Comments Supporting the Adoption
of AHRI 340/360–2022
In response to the June 2022 NOPR,
some commenters supported adopting
AHRI 340/360–2022 in the WSHP test
procedure. NEEA generally supported
DOE’s efforts to align the WSHP test
procedure with other water-cooled
unitary systems, including by
integrating fan energy into the test
procedure for ducted WSHPs. (NEEA,
No. 25 at p. 1) In particular, NEEA
supported DOE’s proposal to align the
WSHP test procedure with AHRI 340/
360–2022 and ANSI/ASHRAE 37–2009.
(Id. at p. 2) NEEA stated that aligning
the testing of WSHPs with ANSI/
ASHRAE 37–2009 would ensure that
WSHP ratings will be consistent with
other water-cooled and direct expansion
cooling systems. (Id.) NEEA also
supported the introduction of an IEER
metric rather than rating only with EER.
(Id.) NEEA stated that the proposed test
procedure would impact the current
modeling approach for WSHP standard
reference systems used to determine
total system performance ratio in the
2018 Washington State Energy Code, but
NEEA acknowledged that potential
advancements to the test procedure and
ratings metric would provide an
important improvement in
representativeness for this equipment.
(Id. at p. 1)
NYSERDA generally supported DOE’s
proposed amendments for the WSHP
test procedure and concurred with
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DOE’s tentative determination that the
changes would improve the
representativeness of the WSHP test
procedure. (NYSERDA, No. 21 at pp. 1–
2) NYSERDA asserted that this would
spur growth in the market for WSHPs,
including geothermal heat pumps. (Id.
at p.2)
As discussed previously, in this final
rule, DOE is incorporating by reference
AHRI 600–2023 into appendix C1 in
lieu of incorporating by reference AHRI
340/360–2022 as proposed in the
August 2022 NOPR. DOE notes,
however, that the majority of the
technical content from the proposed test
procedure in the August 2022 NOPR
remains consistent in the test procedure
finalized in this final rule. Any changes
to technical provisions from the August
2022 NOPR proposal were due to
industry consensus culminating in the
AHRI 600–2023 standard. Throughout
this final rule, DOE discusses in detail
the technical differences between the
test procedure proposed in the August
2022 NOPR and the version finalized in
this final rule.
4. Comments Opposing the Adoption of
AHRI 340/360–2022
Other commenters opposed the
proposal in the August 2022 NOPR to
adopt AHRI 340/360–2022 in the WSHP
test procedure. AHRI and MIAQ
expressed concern that the impact on
manufacturers of DOE’s proposal to
update the WSHP test procedure has not
been quantified. (AHRI, No. 24 at p. 2;
MIAQ, No. 23 at p. 3) AHRI and MIAQ
stated that the capability of testing
WSHPs to AHRI 340/360–2022 has not
been assessed by third-part test labs.
(Id.)
AHRI and MIAQ noted that an
ASRAC Working Group has been
formed in an effort to negotiate test
procedures and energy efficiency
standards for CUAC/HPs, the scope of
which stands to result in significant
modifications to AHRI 340/360–2022
and the efficiency measures for such
equipment. (AHRI, No. 24, at p. 2;
MIAQ, No. 23 at p. 2) AHRI and MIAQ
further noted, however, that WSHPs are
outside the scope of these efforts,
potentially leaving a significant gap in
ratings (i.e., were WSHPs to be rated
using AHRI 340/360). (Id.)
WaterFurnace expressed concern
regarding DOE’s sampling and testing
procedure for modifying AHRI 340/360,
especially considering the complexity of
the product’s controls and operational
characteristics and taking into account
past instances in which DOE has
struggled to duplicate test results
without manufacturer and AHRI testing
support. (WaterFurnace, No. 20 at p. 2)
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WaterFurnace agreed with AHRI’s
concerns that the impact on
manufacturers of DOE’s proposal to
update test procedures has not been
adequately quantified, nor was it clear
whether third-party test labs have the
capability to accommodate the proposed
changes. (Id. at p. 2)
WaterFurnace, ClimateMaster,
Enertech, and FHP all expressed
concern that DOE’s proposal to test
WSHPs using AHRI 340/360–2022
would require manufacturers to test
WSHPs to two different test standards
because geothermal applications for
WSHPs would still require testing to
ISO 13256–1. (WaterFurnace, No. 20 at
p. 3; ClimateMaster, No. 22 at p. 1;
Enertech, No. 19 at p. 1; FHP, No. 26 at
p. 3) WaterFurnace noted that ISO
13256–1 is already referenced in several
Federal, State, and local codes.
(WaterFurnace, No. 20 at p. 3)
WaterFurnace and ClimateMaster stated
that implementing a dual certification
process would be burdensome for
manufacturers. (WaterFurnace, No. 20 at
p. 3; ClimateMaster, No. 22 p. 1)
Enertech also noted that Federal and
State tax credits specifically reference
ISO/AHRI 13256–1:1998 for efficiency
ratings and that the ENERGY STAR
specifications directly reference the ISO
13256–1:1998 standard for the ENERGY
STAR Tier 3 efficiency requirements.
(Enertech, No. 19 at p. 1)
WaterFurnace asserted that DOE
underestimated the significance and the
burden that the proposed changes to the
WSHP test procedure would impose
upon manufacturers and industry
players. (WaterFurnace, No. 20 at p. 3)
WaterFurnace identified the following
assumptions and shortcomings in AHRI
340/360–2022 that it stated were not
appropriately addressed in the August
2022 NOPR:
(1) While the August 2022 NOPR
stated that IEER can be calculated and
an interpolation can be performed using
existing data from ISO 13256–1,
WaterFurnace determined that the
entering air, water flow, external static
and airflow conditions differ from AHRI
340/360–2022, which will therefore
require additional testing by the
manufacturer and the implementation of
a new certification program;
(2) Currently, performance mapping
capability is available across a wide
range of entering water temperatures
(‘‘EWT’’) used in modeling software
such as EQuest and DOE’s EnergyPlus,
and all of this detail would be lost with
the implementation of AHRI 340/360–
2022 because it only presents a single
IEER cooling metric and a single heating
point;
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(3) Provisions should be added under
AHRI 340/360–2022 for hybrid heat
pumps, which are unique in their
capability for refrigerant cooling with
other non-refrigerant heating capability;
(4) Provisions should be added under
AHRI 340/360–2022 for split
configurations, which are offered for
smaller WSHPs;
(5) Provisions should be added under
AHRI 340/360–2022 for small WSHPs
with non-ducted applications (e.g.,
console units), along with language that
takes into account the fact that many of
these units are installed into residential
buildings with substantial heating that
would not fit the AHRI 340/360–2022
conditions;
(6) While DOE proposed to adopt
heating test conditions for WSHPs that
are not specified in AHRI 340/360–
2022, this overlooks other testing
requirements and language that would
need to be addressed (e.g., minimum
and maximum operating conditions) in
order to adequately add heating tests to
a cooling-only standard;
(7) Provisions should be added under
AHRI 340/360–2022 for antifreeze
blends and their fluid characteristics
(i.e., alcohols, salts, and glycols);
(8) Test procedures would need to be
modified to account for smaller WSHP
units, as AHRI 340/360–2022 requires
an airflow tolerance of less than 3
percent and is thus designed around
larger product designs with drives and
adjustable sheaves that accommodate
this airflow capability;
(9) Although AHRI 340/360–2022 is
primarily an air-source standard that
utilizes air and refrigerant enthalpy test
methods, water-source equipment is
more consistently and accurately tested
with a liquid enthalpy test method and
would need to use air or refrigerant
enthalpy only as secondary methods—
and, furthermore, this process would be
inconsistent with part load
measurements under AHRI 340/360–
2022;
(10) Manufacturer-specified liquid
flow rate is preferred over the AHRI
340/360–2022 method of setting liquid
flow rate using a 10 °F temperature rise
to establish flow rates;
(11) Continuous 24/7 fan operation is
an outdated idea according to ASHRAE
90.1; and
(12) Issues addressed by Working
Groups under ASRAC will likely result
in massive changes to AHRI 340/360
regarding air-side measurements and
will take focus away from necessary
modifications to provisions for watercooled units and, thus, changes for
water-cooled units to AHRI 340/360 will
likely be of secondary importance to the
ASRAC committee. (Id. at pp. 3–4)
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WaterFurnace also commented that
because AHRI 340/360–2022 is
primarily an air-source standard, AHRI
340/360–2022’s comparatively small
water-cooled section is used to certify
approximately 1,000 units per year in
contrast to the 200,000 unit sales per
year under the AHRI/ISO 13256
certification programs. (Id. at p. 5)
Therefore, WaterFurnace noted that
moving testing of WSHPs (with much
higher shipments) to the smaller watercooled section of AHRI 340/360–2022
would not be logical considering the
noted changes required. (Id.)
WaterFurnace commented that
changing to a different AHRI 340/360–
2022 standard and separating out
geothermal applications to ISO 13256
would be disruptive to both the watersource and geothermal industries at a
time when the use of heat pumps is
being encouraged by national, state, and
local regulations as a carbon-reduction
solution. (Id.) WaterFurnace stated that
tax credits and rebates based upon
AHRI/ISO 13256 performance have been
legislatively codified and will be
difficult to change, and further noted
that the Inflation Reduction Act
references ASHRAE 90.1 and AHRI/ISO
13256 as a measurement of
performance. (Id. at p. 6) WaterFurnace
stated that other governmental programs
such as ENERGY STAR have
specifications and benefits based on
AHRI/ISO 13256 performance
certification and that decarbonization
policy programs by utilities, cities, and
states rely on such certification as well.
(Id.)
ClimateMaster commented that DOE
would need to address the following
issues with AHRI 340/360–2022:
(1) AHRI 340/360–2022 needs to be
updated to include the appendix C1
additions, a process that will likely be
delayed by a current ASRAC working
group undertaking to amend the current
AHRI 340/360–2022 test procedures
with a focus on air-source equipment;
(2) AHRI 340/360–2022 does not
include test requirements for watersource heating;
(3) AHRI 340/360–2022 does not
include test provisions for non-ducted
equipment;
(4) The airflow setting and tolerance
specified by AHRI 340/360–2022 does
not cover or is incompatible with
current WSHP equipment;
(5) AHRI 340/360–2022 does not
include a pump power adder for all
equipment sizes, nor is DOE’s proposal
to utilize the pump power adder in
AHRI 920 representative of installed
WSHP systems;
(6) AHRI 340/360–2022 does not
include glycols or antifreeze solutions
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in the method of test, and the
recommended solution is not
representative of the fluids used for
WSHPs in the field or test laboratories
currently used in the development,
qualification, and compliance processes;
and
(7) The refrigerant charging
requirements included in AHRI 340/
360–2022 are not applicable, accurate,
or relevant to WSHP systems.
(ClimateMaster, No. 22 at pp. 1–2)
Enertech commented that AHRI 340/
360–2022 lacks testing parameters for
water source heating, testing parameters
for non-ducted equipment, testing
methods utilizing antifreeze blends, and
parameters for pump power adder for
small equipment. (Enertech, No. 19 at p.
1) Enertech noted that AHRI 340/360–
2022 requires a ±3 percent airflow
tolerance during testing, which Enertech
asserted is unrealistic for small-capacity
equipment. (Id.) For these reasons,
Enertech disagreed that new efficiency
ratings could be interpolated from
conditions common to the WSHP
industry and asserted that new testing
would be required for all products
offered by any manufacturer. (Id.)
Enertech stated that adopting AHRI 340/
360–2022 as the DOE test procedure for
WSHPs would result in long-term
disruptions to the geothermal and
WSHP industries. (Id. at p. 2)
FHP commented that adopting test
methods per AHRI 340/360–2022 would
require additional testing effort, time,
and resources, and would result in
additional costs to the industry. (FHP,
No. 26 at p. 3) FHP commented further
that AHRI 340/360–2022 contains
differences in standard test conditions
that would require additional testing as
well as changes to (1) the design of the
units to ensure 10 °F temperature rise on
the water side and (2) the fan/motor
selections and programs to maintain the
proper air flow at defined static
pressures and airflow tolerances. (Id.)
FHP stated that the use of two standards
may split the current WSHP product
designs, thereby adding permanent
design burden to current product
offerings. (Id.)
FHP stated that the proposed changes
to the WSHP test procedure could be the
most impactful regulatory issue for the
WSHP industry and that the industry’s
resources are completely dedicated to
the development of equipment that uses
low-global warming potential
refrigerants through January 1, 2025.
(FHP, No. 26 at p. 5) FHP expressed
concern about the impact of moving to
an entirely new test procedure that
would require re-testing, re-designing,
and potentially re-certifying most of its
basic model groups. (Id.) FHP also
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expressed concerns about the additional
resources and maintenance potentially
required by having two separate product
designs and validations for WSHPs. (Id.)
FHP also stated that current AEDMs
are based on the leading industry
standard for these types of equipment.
(Id. at p. 2) More specifically, FHP
stated that its current AEDM is based on
the ISO 13256–1:1998 test standard and
that DOE’s proposal to reference AHRI
340/360–2022 as the test procedure for
WSHPs would require additional testing
and new AEDMs. (Id.) FHP commented
that even reduced testing to validate
AEDMs would be unduly burdensome
for such a small market. (Id.)
During the public meeting, AAON
commented that the amount of testing in
the proposed test procedure was rather
extreme and asked DOE to share the
testing burden assessment. (Public
Meeting Transcript, No. 17 at p. 60)
GeoExchange commented that
manufacturers of geothermal heat
pumps have significant concerns with
the August 2022 NOPR as written and
believe it will subject WSHPs and
geothermal heat pumps to competing
and inconsistent certification standards.
(GeoExchange, No. 29 at p. 1)
GeoExchange commented that these
issues will complicate production of
these products and increase costs for
consumers. (Id.) GeoExchange stated
that the timing of the August 2022
NOPR coincides with efforts by the
industry to complete work on its
development of a standard that
recognizes the overlap between different
applications of heat pump technology
and minimizes unnecessary disruptions
for manufacturers. (Id.)
DOE appreciates these comments
regarding the proposal to adopt AHRI
340/360–2022 in the WSHP test
procedure. As discussed, in this final
rule, DOE is no longer adopting AHRI
340–360–2022 and is adopting instead
an amended test procedure for WSHPs
that incorporates by reference AHRI
600–2023. Because AHRI 600–2023 was
developed through an industry
consensus process subsequent to the
timing of the August 2022 NOPR
comment period, DOE surmises that the
testing approach specified in AHRI 600–
2023 represents the prevailing industry
consensus regarding the most
appropriate method of testing WSHPs
and addresses the issues raised by
commenters regarding DOE’s proposal
to adopt AHRI 340/360–2022 as the test
procedure for WSHPs. See sections III.E
and III.F of this final rule for discussion
of specific test procedure topics raised
by interested parties in response to the
August 2022 NOPR.
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Further, in response to the test burden
comments, DOE did quantify per-test
burden of the proposed test procedure
in the August 2022 NOPR and found
that the proposed test procedure was
not unduly burdensome to conduct. 87
FR 53302, 53340. A similar analysis is
presented in this final rule (see section
III.I of this document for details), and
the same conclusion is reached.
Additionally, as discussed in this
document, DOE is adopting a test
procedure incorporating by reference
the industry consensus test standard,
AHRI 600–2023. Therefore, DOE has
determined that the amended test
procedure will not increase burden as
compared to the latest draft industry
consensus test standard.
5. Comments Encouraging the Adoption
of AHRI 600
Numerous commenters encouraged
DOE to adopt AHRI 600 in an amended
WSHP test procedure in response to the
August 2022 NOPR. AHRI
recommended that DOE refrain from
adopting AHRI 340/360–2022 for
WSHPs in favor of continuing to
collaborate with industry on finalizing
AHRI 600. (AHRI, No. 24 at p. 4) AHRI
commented that AHRI 600 has been
under development for several years
and that, despite some delays, is
steadily progressing. (Id.) AHRI
commented that during the discussions
for the development of AHRI 600, the
committee considered applying AHRI
340/360–2022 to calculate IEER. (Id.)
AHRI commented that it continues to
improve AHRI 600 test procedures (e.g.,
by resolving issues to fan power,
external static pressure, water
temperature, and subsequent efficiency
levels) and that AHRI will continue
committing to frequent meetings to
satisfactorily resolve the issues raised in
August 2022 NOPR. (Id.)
WaterFurnace stated that AHRI 600
draft standard was released in October
2022 and achieves the objectives of the
August 2022 NOPR without industry
distractions. (WaterFurnace, No. 20 p. 5)
WaterFurnace commented that AHRI
600 standard is on track for committee
review by October 31, 2023. (Id.)
WaterFurnace stated that the quickest
way to implement appropriate changes
to WSHP test procedures would be to
adopt versions of AHRI 600 and ISO
13256–1, as modifying test procedures
to comply with AHRI 340/360–2022
would entail substantial changes that
will delay the implementation process.
(Id. at p. 4)
WaterFurnace commented that it
supports development of AHRI 600 test
procedure and recommended that the
DOE test procedure reference it directly
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instead of AHRI 340/360–2022. (Id. at p.
5) WaterFurnace stated that the AHRI
600 standard can resolve most of the
issues DOE identified in the August
2022 NOPR regarding the current WSHP
test procedure. (Id.) WaterFurnace
recommended that DOE re-evaluate the
August 2022 NOPR proposal and
support WaterFurnace’s proposal to
quickly adopt AHRI 600 and the
national deviation updates to AHRI/ISO
13256. (Id. at p. 11) WaterFurnace
commented that doing so will help
industry achieve DOE’s desired goals
faster and with less disruption. (Id.)
WaterFurnace commented that it
supports implementation of an updated
AHRI/ISO 13256:1998 with a targeted
national deviation and revised annexes.
(Id. at p. 5) WaterFurnace commented
that an updated AHRI/ISO 13256:1998
with a targeted national deviation can
solve specific issues mentioned in the
August 2022 NOPR regarding AHRI/ISO
13256 with changes that would not be
substantial, stating that the method of
testing WaterFurnace follows aligns
with the August 2022 NOPR. (Id.)
WaterFurnace commented that many of
the issues raised by DOE center on
specific issues and test methods
currently in use that can be documented
and solved with a national deviation
from AHRI/ISO 13256. (Id.)
WaterFurnace stated that it has
developed a draft of this national
deviation that will address the noted
shortcomings and can be completed in
a similar time frame as AHRI 600
approval. (Id.)
ClimateMaster commented that DOE’s
proposal to move WSHPs to AHRI 340/
360–2022 would create too significant a
change in the industry and instead
recommended considering AHRI 600,
which uses existing ISO/AHRI 13256–1
certified data to mathematically
calculate the system IEER.
(ClimateMaster, No. 22 at p. 1)
ClimateMaster further commented that
DOE should consider updating the ISO/
AHRI 13256–1:1998 standard to include
national deviations to address specific
issues such as: (1) modifying refrigerant
charging and airflow/ESP requirements;
and (2) the need to include a reference
to ASHRAE 37 and provisions for air
sampling for air-side capacity
measurements. (Id. at p. 2)
Enertech suggested adopting AHRI
600 for calculating IEER rather than the
AHRI 340/360–2022 method. (Enertech,
No. 19 at p. 2)
MIAQ recommended that DOE work
with industry to finalize AHRI Standard
600, conduct any necessary testing/
calculations to develop a crosswalk, and
follow proper procedures to introduce
the finalized procedure and updated
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efficiency standards in ASHRAE 90.1.
(MIAQ, No. 23 at p. 9)
Trane recommended that DOE move
from a full-load metric and test
procedure to one that is more
representative of an energy use cycle,
such as a part-load test procedure.
(Trane, No. 28 at p. 3) Trane commented
that the most accurate and
representative test procedure is AHRI
600, not AHRI 340/360–2022 as
proposed in the August 2022 NOPR.
(Id.) Trane noted that AHRI 600 draft is
now published and seeking public
comments for the final version. (Id. at p.
2)
As discussed, in this final rule, DOE
is adopting an amended test procedure
for WSHPs incorporating by reference
AHRI 600–2023. As noted in the
previous discussion, the methodology
specified in ISO 13256–1 has been
incorporated into the AHRI 600–2023,
which represents the latest industry
consensus test standard for WSHPs and
moves away from using ISO 13256–1,
thus rendering unnecessary a national
deviation to ISO 13256–1. Having been
developed through an industry
consensus process subsequent to the
timing of the August 2022 NOPR
comment period, DOE surmises that the
testing approach specified in AHRI 600–
2023 represents the prevailing industry
consensus regarding the most
appropriate method of testing WSHPs.
6. Finalized DOE Test Procedure
In summary, DOE is adopting an
amended test procedure for WSHPs that
incorporates by reference AHRI 600–
2023, with minor deviations, in this
final rule. DOE has determined that the
test methods specified in AHRI 600–
2023 (which are largely consistent with
the provisions adopted in appendix C1
of this final rule) would produce test
results that better reflect energy
efficiency of WSHPs during a
representative average use cycle than
the current DOE test procedure and ISO
13256–1:1998. DOE notes that the IEER
metric is representative of cooling
efficiency for WSHPs on an annual basis
and is more representative than the
current EER metric, which captures the
system performance at a single, full-load
operating point. DOE also notes that the
other test procedure amendments
incorporated in this final rule better
ensure accurate and repeatable
measurements and ensure that
representative test conditions are
maintained during testing. These
changes include:
(1) Minimum ESP requirements,
instructions for setting airflow and ESP,
and tolerances for airflow and ESP;
(2) Operating tolerance for voltage;
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(3) Different indoor air conditions for
testing;
(4) Refrigerant charging instructions
for cases where they are not provided by
the manufacturer;
(5) Use of the primary capacity
measurement (i.e., indoor air enthalpy
method) as the value for capacity, and
different provisions for required
agreement between primary and
secondary capacity measurements;
(6) Provisions for split systems, such
as accounting for compressor heat and
refrigerant line losses;
(7) Measurement of duct losses for
ducted units;
(8) Standardized heat capacity of
water and brine; and
(9) A calculation for discharge
coefficients.
The subsequent sections of this final
rule discuss aspects of the finalized test
procedure that differ from the proposal
in the August 2022 NOPR. DOE has
determined that these updates improve
the representativeness of the test
procedure for WSHPs. These include
but are not limited to:
(1) Updated pump power adder,
developed during the AHRI 600–2023
process;
(2) ESP requirements for large units
>65,000 Btu/h consistent with levels
from the December 2022 term sheet of
recommendations regarding test
procedures for air-cooled commercial
unitary air conditioners and heat pumps
(‘‘ACUACs and ACUHPs’’), referred to
hereafter as ‘‘the ACUAC and ACUHP
Working Group TP Term Sheet’’ (See
Document No. 65 in Docket No. EERE–
2022–BT–STD–0015);
(3) No option to physically test at the
IEER conditions and to instead require
testing at all three ISO 13256–1:1998
conditions;
(4) Updated part-load EWT;
(5) Specifying a maximum water flow
rate instead of fixed inlet and outlet
water conditions;
(6) Different test provisions for coilonly units, including adjustments to
default fan power;
(7) Different required fluid—a
methanol solution—and different fluid
properties specified;
(8) Some changes to airflow
provisions, which are consistent with
DOE’s test procedure for central air
conditioners and heat pumps at
appendix M1 to subpart B of 10 CFR
part 430 instead of AHRI 340/360–2022;
(9) IEER cyclic degradation equation
that does not assume continuous fan
operation; and
(10) Heating test temperature of 50 °F
instead of 55 °F.
As discussed, DOE recognizes that the
test method in AHRI 600–2023 and
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incorporated by reference into appendix
C1 represents an industry consensus test
procedure that is likely to be considered
for future updates to ASHRAE 90.1.
Accordingly, for the foregoing reasons
and those discussed in the subsequent
sections of this final rule, DOE is
incorporating by reference AHRI 600–
2023 into the amended Federal test
procedure for WSHPs. DOE has
determined that the amended test
procedure is reasonably designed to
produce results that are representative
of the energy efficiency of that covered
equipment during an average use cycle
and is not unduly burdensome to
conduct. DOE notes also that use of
appendix C1 will not be required until
the compliance date of any amended
standards denominated in terms of
IEER, should DOE adopt such standards.
E. Efficiency Metrics
1. IEER
As discussed previously, DOE’s
current test procedure for WSHPs
measures cooling-mode performance in
terms of the EER metric, the current
regulatory metric. 10 CFR 431.96. EER
captures WSHP performance at a single,
full-load operating point in cooling
mode (i.e., a single EWT) and does not
provide a seasonal or load-weighted
measure of energy efficiency. A seasonal
metric is a weighted average of the
performance of cooling or heating
systems at different outdoor conditions
intended to represent average efficiency
over a full cooling or heating season.
Several categories of commercial
package air-conditioning and heating
equipment are rated using a seasonal or
part-load metric, such as IEER. IEER is
a weighted average of efficiency at four
load levels representing 100, 75, 50, and
25 percent of full-load capacity, each
measured at a specified outdoor
condition that is representative of field
operation at the given load level. In
general, the IEER metric provides a
more representative measure of field
performance than EER by weighting the
full-load and part-load efficiencies by
the average amount of time equipment
spends operating at each load level.
Table 1 of ISO 13256–1:1998, the
industry test standard incorporated by
reference into DOE’s current WSHP test
procedure, and Table 2 of ISO 13256–
1:2021 both specify EWT conditions to
be used for developing part-load ratings
of EER for WSHPs with capacity control
(tested at minimum compressor speed).
However, part-load EER ratings are not
addressed in the current DOE test
procedure. Further, each part-load
rating captures operation only at a
single compressor speed and EWT
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condition rather than operation across a
range of temperatures and compressor
speeds, as would be captured by an
IEER metric. Neither ISO 13256–1:1998
nor ISO 13256–1:2021 include seasonal
metrics.
In the August 2022 NOPR, DOE
tentatively determined that use of a
seasonal efficiency metric would be
more representative of the average use
cycle of a unit as compared to the
current EER metric. 87 FR 53302, 53313.
Accordingly, DOE proposed to adopt
certain provisions of AHRI 340/360–
2022 and use the IEER metric specified
in section 6.2 of AHRI 340/360–2022 for
WSHPs. Id. Specifically, DOE proposed
that IEER for WSHPs be calculated
based on the EWT conditions specified
in Table 9 of AHRI 340/360–2022 (i.e.,
85 °F, 73.5 °F, 62 °F, and 55 °F). Id. DOE
referred to the approach of testing at
these AHRI 340/360–2022 EWTs as
‘‘option 1’’ in the August 2022 NOPR.
Id. at 87 FR 53316.
In addition, DOE acknowledged in the
August 2022 NOPR that adopting the
IEER metric for WSHPs would increase
the number of required cooling-mode
tests from one to four. Id. at 87 FR
53313. DOE also discussed its
understanding that the future updated
version of AHRI 600 would provide for
calculating IEER from test results
measured at the EWTs specified in
Table 1 of ISO 13256–1:1998. Id. DOE
stated that determining IEER via
interpolation and extrapolation from
testing at the ISO 13256–1:1998 EWTs,
rather than from additional testing at the
IEER EWTs specified in AHRI 340/360–
2022, may reduce overall testing burden
for manufacturers. Id. at 87 FR 53314.
Consistent with this approach, DOE also
proposed to allow determination of
IEER via interpolation and extrapolation
(‘‘option 2’’) based on testing at the fullload and part-load EWT conditions
specified in Table 1 of ISO 13256–
1:1998 (i.e., 86 °F, 77 °F, and 59 °F for
full-load tests and 86 °F, 68 °F, and 59 °F
for part-load tests). Id. at 87 FR 53316.
DOE proposed that the tests for option
2 would be performed using the same
test provisions (aside from the EWTs)
from AHRI 340/360–2022, ANSI/
ASHRAE 37–2009, and sections 2
through 4 and 7 of proposed appendix
C1 as the tests for option 1. Id.
In the August 2022 NOPR, DOE
presented test data that indicated that
determining EER by interpolating/
extrapolating cooling capacity and total
power would result in closer agreement
to tested values than directly
interpolating/extrapolating EER. Id. at
87 FR 53314–53315. Based on these
findings, DOE proposed to specify
interpolation/extrapolation using the
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cooling capacity and total power as
opposed to EER directly. Id. at 87 FR
53316. DOE also presented data in the
August 2022 NOPR indicating that for
variable-speed WSHPs with higher (i.e.,
better) EER performance at intermediate
compressor speeds than at maximum or
minimum compressor speeds, the
proposed interpolation and
extrapolation method would result in a
lower (i.e., worse) calculated IEER than
testing at the IEER conditions specified
in AHRI 340/360–2022. Id. at 87 FR
53315–53316. DOE discussed its
understanding from participation in
AHRI 600 committee meetings that
many manufacturers would prefer the
option to use the interpolation and
extrapolation method for variable-speed
WSHPs, even if it results in lower IEER
ratings, because it would result in less
overall testing burden than testing at
each of the AHRI 340/360–2022
conditions. Id. at 87 FR 53316.
DOE also proposed that if represented
values for a basic model are determined
with an AEDM, the AEDM could use
either option 1 or option 2 for
determining IEER per the proposed test
procedure in appendix C1. Id.
DOE requested comment on the
proposal to allow determination of IEER
using two different methods: (1) testing
in accordance with AHRI 340/360–2022;
or (2) interpolation and extrapolation of
cooling capacity and power values
based on testing in accordance with the
proposed test procedure at the EWTs
specified in Table 1 of ISO 13256–
1:1998. Id. DOE sought feedback on the
proposed method for calculating IEER
via interpolation and extrapolation, and
on whether this approach would serve
as a potential burden-reducing option as
compared to testing at the AHRI 340/
360–2022 conditions. Id. DOE also
requested comment on whether the
proposed methodology to determine
IEER based on interpolation and
extrapolation is appropriate for variablespeed units. Id. DOE noted it would
consider requiring variable-speed
equipment be tested only according to
AHRI 340/360–2022 and, thus, testing
physically at the IEER EWTs, if
suggested by commenters. Id. Finally,
DOE sought feedback on whether the
proposed interpolation and
extrapolation method should be based
on testing at the ISO 13256–1:2021
EWTs (which differ from the ISO
13256–1:1998 EWTs for certain test
points). Id.
Some commenters opposed DOE’s
proposals regarding the IEER metric in
the August 2022 NOPR. ClimateMaster,
MIAQ, and WaterFurnace recommended
that DOE adopt the test methods
specified in AHRI 600 instead of AHRI
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340/360–2022 for calculating the IEER
of WSHPs. (ClimateMaster, No. 22 at pp.
3–5; MIAQ, No. 23 at p. 4;
Waterfurnace, No. 20 at pp. 6–7) MIAQ
stated that AHRI 600 will provide a
method for calculating a seasonal
cooling efficiency metric for WSHPs
(i.e., IEER) based on testing conducted
according to ISO 13256–1:1998. (MIAQ,
No. 23 at p. 4) MIAQ stated that that the
estimated AHRI 600 approval date of
October 1, 2023 would meet DOE’s
timeline for adopting the standard. (Id.)
ClimateMaster commented that
adopting the test methods specified in
AHRI 340/360–2022 would require
manufacturers to certify products under
two programs (i.e., AHRI 340–360 and
ISO/AHRI 13256), which is
unprecedented in the industry, and
would pose challenges for
manufacturers, third-party labs, and
partners to test and maintain two
certification programs. (ClimateMaster,
No. 22 at p. 3)
ClimateMaster recommended that
DOE utilize data created through ISO
13256–1:1998 to interpolate per the
procedure provided in AHRI 600.
(ClimateMaster, No. 22 at p. 4)
ClimateMaster disagreed with DOE’s
proposal for ‘‘option 2’’ to interpolate
and extrapolate cooling capacity and
total power instead of directly
interpolating/extrapolating EER and
argued that the method in the draft
AHRI 600 at the time should be used,
which is based on directly
interpolating/extrapolating EER. (Id.)
ClimateMaster further argued that the
difference between the two
methodologies is within the uncertainty
of measurement for testing WSHPs and,
therefore, that DOE’s proposed
deviation from the methodology in
AHRI 600 (at the time) is unnecessary.
(Id.) ClimateMaster further commented
that their analysis of a random sample
of performance data for five systems
tested in their labs showed that, on
average, interpolating/extrapolating
based on EER resulted in slightly more
accurate numbers than interpolating/
extrapolating based on capacity and
power. (Id. at pp. 4–5)
ClimateMaster recommended that
DOE maintain the existing ISO 13256–
1:1998 standard until the WSHP
industry adopts the updated standard
and suggested that DOE adopting a
national deviation of ISO 13256–1:2021
would be practical as long
manufacturers are given significant time
to adopt the new test procedure.
(ClimateMaster, No. 22 at p. 5)
ClimateMaster commented that there are
several changes introduced in ISO
13256–1:2021 that it believes provide a
more effective performance map for a
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WSHP system, but that this standard has
not yet been adopted by the WSHP
industry. (Id.) ClimateMaster further
commented that the EWTs utilized for
determining IEER via interpolation/
extrapolation are irrelevant as long as
DOE requires that the entering air
temperatures and other items are
inconsistent from the current ISO
13256–1:1998 test program. (Id.)
Regarding DOE’s request for comment
on variable-speed unit testing,
ClimateMaster commented that DOE’s
test results from the units sampled and
tested at a third-party lab should be
shared with stakeholders for review and
comment—particularly regarding
variable speed units, as most of these
require hardware and software from the
manufacturer to allow for proper testing,
and test instructions were not provided
to DOE for the department’s testing of
variable-speed units as would be done
for normal certification testing.
(ClimateMaster, No. 22 at p. 4)
MIAQ commented that the proposed
interpolation and extrapolation method
should be based on testing at the ISO
13256–1:2021 EWTs. (MIAQ, NO. 23 at
p. 4) Regarding the proposed ‘‘option 2’’
approach for determining IEER via
interpolation/extrapolation for variablespeed units, MIAQ recommended DOE
use the latest edition of ISO 13256–
1:2021 as the test procedure and
continue to use AHRI 340/360–2022 for
IEER calculations. (Id.)
Other commenters supported DOE’s
proposals regarding the IEER metric in
the August 2022 NOPR. The Joint
Commenters supported adopting a partload metric to measure cooling
efficiency performance, stating that
WSHPs, like many other commercial air
conditioners and heat pumps, operate a
significant percent of the time at partload conditions, and that a part-load
metric could incentivize designs that
reduce annual energy consumption.
(Joint Commenters, No. 27 at pp. 1–2)
The Joint Commenters recommended
DOE ensure that an adopted part-load
metric reflects the total cooling
provided divided by the total energy
consumed and noted that they have
previously commented that the IEER
metric likely does not reflect the total
cooling provided divided by the total
energy consumed, and instead weights
efficiencies calculated at different loadpoints. (Id.)
NEEA supported DOE’s proposed
transition from regulating WSHP
efficiency based on a full-load EER
metric to a multi-capacity IEER metric.
(NEEA, No. 25 at p. 2) NEEA
commented that an IEER metric is more
representative of overall equipment
performance, and that optimizing part-
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load efficiencies is beneficial to both
consumers and utilities because
heating/cooling equipment operates at
peak capacity for a small number of
hours. (Id.) NEEA recommended that
DOE move to the IEER metric for
regulatory purposes while still
encouraging manufacturers to also
publish full-load EER data, given the
importance of EER data for peak load
performance and planning for utilities.
(Id.) NEEA commented that it is
encouraged by DOE’s monitoring of the
development of the AHRI Standard 600
and stated that this standard will allow
for even more representative ratings of
regional seasonal heating and cooling
efficiencies. (Id.)
NYSERDA supported DOE’s proposal
to adopt for WSHPs the testing methods
specified in AHRI 340/360–2022 for
calculating IEER, stating that a seasonal
efficiency metric is more representative
of the part-load operation and varying
temperature conditions seen in actual
field performance of WSHPs.
(NYSERDA, No. 21 at p. 2)
As discussed in section III.D, DOE is
incorporating by reference AHRI 600–
2023 into its amended WSHP test
procedure. Section 6.3 of AHRI 600–
2023 uses a method for determining
IEER that is similar to the interpolation
method proposed in the August 2022
NOPR, including tests at three EWTs,
interpolating from those EWTs to the
IEER EWTs specified in AHRI 340/360–
2022, and adjusting the efficiency from
the tested and interpolated load
percentages to the IEER load
percentages.
With regards to ClimateMaster’s
comment on the interpolation
methodology (i.e., interpolating the
capacity and power vs. interpolating
EER directly), DOE discussed this issue
with stakeholders in AHRI 600 meetings
after publication of the August 2022
NOPR, and section 6.3.4 of AHRI 600–
2023 includes interpolation of capacity
and power, consistent with the
approach proposed in the August 2022
NOPR.7 Having been developed through
an industry consensus process
subsequent to the timing of the August
2022 NOPR comment period, DOE
surmises that the interpolation approach
specified in AHRI 600–2023 represents
the prevailing industry consensus
regarding the most appropriate method
of performing the interpolation of
capacity and power and addresses the
issues raised by commenters regarding
DOE’s proposed methodology for the
7 As discussed later in this section, the lowest
EWT in AHRI 600–2023 is 50 °F, which is lower
than the lowest IEER EWT (55 °F), such that the
AHRI 600–2023 approach does not require
extrapolation for determining IEER.
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interpolation method in the August
2022 NOPR.
With regards to the comment from the
Joint Commenters recommending that
DOE adopt a part-load metric that
reflects the total cooling provided
divided by the total energy consumed,
DOE notes that no industry test
procedures for WSHPs include a metric
using such an equation format instead of
the equation format for IEER (which is
a weighted average of EERs at four
different EWTs) and the Joint
Commenters did not provide sufficient
information to support development of
such an equation format for WSHPs.
Therefore, at this time, DOE has
concluded that it lacks the necessary
information to adopt an integrated
metric other than IEER for WSHPs.
While much of the methodology to
determine IEER adopted in this final
rule is consistent technically with the
proposal from the August 2022 NOPR,
DOE notes the following differences
between the approach adopted in this
final rule (consistent with AHRI 600–
2023) and the proposals in the August
2022 NOPR:
(1) Removal of option for testing
directly at IEER EWTs. In this final rule,
DOE is not adopting the proposed
option 1 methodology of directly testing
at the IEER EWTs (i.e., 85 °F, 73.5 °F,
62 °F, 55 °F). Rather, consistent with
section 6.3 of AHRI 600–2023, the test
procedure adopted in this final rule
specifies that IEER is determined via
interpolation from tests at ISO 13256–1
EWTs, which is similar to option 2 as
proposed in the August 2022 NOPR.
With regards to NYSERDA’s comment
supporting adopting AHRI 340/360–
2022 to calculate IEER, DOE notes that
the methodology specified in AHRI
600–2023 is very similar and produces
near identical results to the
methodology of AHRI 340/360–2022, as
demonstrated through DOE’s data
presented in the August 2022 NOPR.
See 87 FR 53302, 53316.
(2) Change in full-load test EWTs. The
full-load test temperatures used for
interpolation in section 6.2.1 of AHRI
600–2023 are consistent with ISO
13256–1:2021 (i.e., 86 °F, 68 °F, 50 °F)
instead of ISO 13256–1:1998 (i.e., 86 °F,
77 °F, 59 °F), which was proposed in the
August 2022 NOPR. This is also
consistent with the comment from
MIAQ that encouraged the use of ISO
13256–1:2021 EWTs.
(3) Change in part-load test EWTs.
The part-load test EWTs used for
interpolation in section 6.3.2 of AHRI
600–2023 are the same as the full-load
EWTs (i.e., 86 °F, 68 °F, 50 °F). This
differs from the approach in the August
2022 NOPR, which proposed to align
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with the EWTs specified in ISO 13256–
1:1998 (i.e., 86 °F, 77 °F, and 59 °F for
full-load tests; 86 °F, 68 °F, and 59 °F for
part-load tests). MIAQ encouraged the
use of ISO 13256–1:2021, which
specifies part-load test EWTs of 77 °F,
59 °F, and 41 °F. The part-load EWTs in
section 6.3.2 of AHRI 600–2023 (86 °F,
68 °F, 50 °F) are not consistent with
either the 1998 or 2021 versions of ISO
13256–1, and instead reflect the
conclusion of discussions in AHRI 600
committee meetings that conducting
part-load tests at the same EWTs as fullload tests would reduce testing burden
(by reducing the number of times the
water temperature would need to be
reconditioned between tests) and better
align with the IEER methodology in
AHRI 340/360–2022. DOE surmises that
the part-load EWTs specified in section
6.3.2 of AHRI 600–2023 represent the
prevailing industry consensus regarding
the most appropriate EWTs for testing
WSHPs. In addition, as compared to the
part-load EWTs proposed in the August
2022 NOPR (the lowest of which was
59 °F), the lowest part-load EWT in
AHRI 600–2023 (50 °F) is lower than the
lowest IEER EWT (55 °F). Therefore, use
of the part-load EWTs in AHRI 600–
2023 means that all IEER EWTs can be
interpolated from the tested EWTs,
instead of requiring any extrapolation.
As a result, in this final rule DOE is
adopting the part-load EWTs as outlined
in the AHRI 600–2023 through
incorporation by reference.
(4) Updated provisions for variable
speed units. The approach for
determining IEER for variable-speed
WSHPs specified in AHRI 600–2023
differs from the approach proposed in
the August 2022 NOPR in that
additional tests are required at
intermediate compressor speeds.
Specifically, section 6.3.2 of AHRI 600–
2023 requires that three tests be
performed at each EWT, at the three
following compressor speeds: (1)
maximum compressor speed (i.e., fullload test); (2) minimum compressor
speed; and (3) an intermediate
compressor speed that reflects the
compressor stage with a capacity closest
to half-way between the capacities
measured at the minimum and
maximum compressor speeds. This
third test reduces the range of
compressor speeds over which
interpolation must be conducted (i.e.,
interpolating between intermediate
compressor speed and maximum or
minimum compressor speeds, instead of
between maximum compressor speed
and minimum compressor speed), thus
reducing the extent to which
interpolated results might differ from
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unit performance at the IEER EWTs.
DOE surmises that the approach for
variable speed units specified in section
6.3.2 of AHRI 600–2023 represents the
prevailing industry consensus regarding
the most appropriate method. Therefore,
in this final rule, DOE is adopting the
IEER determination method for variablespeed units from AHRI 600–2023
through incorporation by reference into
appendix C1 of section 6.3.2.
Additionally, DOE presumes this
updated methodology resolves
Climatemaster’s request for DOE’s
variable speed test data, as DOE is
adopting the industry consensus
methodology.8
(5) Change in cyclic degradation
equation. See section III.E.1.a of this
document for detailed discussion.
Finally, DOE is defining ‘‘IEER’’ in 10
CFR 431.92 as a weighted average
calculation of mechanical cooling EERs
determined for four load levels and
corresponding rating conditions,
expressed in Btu/watt-hour and that
IEER is measured per appendix C1 to
subpart F of part 431 for water-source
heat pumps.
a. Cyclic Degradation
In the August 2022 NOPR, DOE
proposed to adopt specific sections of
AHRI 340/360–2022 in its amended test
procedure for WSHPs, including section
6.2.3.2. 87 FR 53302, 53327. Equation 4
in section 6.2.3.2 of AHRI 340/360–2022
is used to calculate part-load EER for a
unit that needs to cycle in order to meet
the 75-percent, 50-percent, and/or 25percent load conditions required for the
IEER metric. Id. Cycling is the term used
to describe the process in which a unit’s
compressor is repeatedly turned off and
on in order to meet a load that is lower
than the unit’s capacity at its lowest
compressor stage. Id. Equation 4 of
AHRI 340/360–2022 multiplies only the
compressor power and condenser
section power by the load factor and the
coefficient of degradation, while the
indoor fan power and controls power
are not multiplied by these variables. Id.
This means that equation 4 of AHRI
340/360–2022 assumes that the indoor
fan continues to operate when the
compressor cycles off. Id.
DOE requested comment on the
proposal to adopt the cyclic degradation
equation specified in section 6.2.3.2 of
8 Section 6.3.2.4 of AHRI 600–2023 further
specifies that if the continuous capacities of two
compressor modulation levels allowed by the
controls at a single set of operating conditions are
equidistant from the arithmetic mean of the
capacities from the minimum and maximum
compressor modulation levels at the same set of
operating conditions, the intermediate compressor
modulation level used for testing is the compressor
modulation level with the lower capacity.
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AHRI 340/360–2022 for WSHPs, which
assumes continuous indoor fan
operation when the compressor cycles
off. Id. at 87 FR 53328.
ClimateMaster commented that the
assumption of continuous fan operation
in the AHRI 340/360 IEER calculations
is neither representative of field
operation nor is it in alignment with
guidance provided by ASHRAE 90.1.
(ClimateMaster, No. 22 at p. 3)
ClimateMaster stated that, according to
data it collected through consumer
surveys, 16 percent of installed systems
cycle fan operation with the
compressor, 52 percent operate the fan
continuously while a building is
occupied but cycle the fan with the
compressor when unoccupied, and only
14 percent of installed WSHPs run the
fan continuously regardless of
occupancy and compressor operation,
while the remaining 18 percent
responded that they were unaware of
how their WSHP system cycles
operated. (Id. at p. 3) ClimateMaster
recommended that DOE instead use
AHRI 600 method that does not assume
continuous fan operation. (Id. at p. 8)
ClimateMaster commented that, for
WSHPs that are installed to operate the
fan continuously, models with a multispeed motor will operate at the cooling
fan speed, while variable-speed models
have an option to adjust the continuous
fan speed to a lower value. (Id.)
WaterFurnace commented that
supporting ISO 13256 and AHRI 600
would solve the issue. (WaterFurnace,
No. 20 at p. 8) WaterFurnace stated that
continuous indoor fan operation is not
the most appropriate logic in coolingdominated environments and
recommended demand controls
ventilation as a better use of energy that
improves latent moisture removal. (Id.)
In response to these comments, DOE
notes that section 6.3.6.4 of AHRI 600–
2023 has an equation similar to equation
4 of AHRI 340/360–2022, but the
equation in AHRI 600–2023 assumes
that the indoor fan stops operating
whenever the compressor cycles off.
The data provided by ClimateMaster
suggest that the vast majority of
installed WSHPs do not operate the fan
continuously in all operating modes, but
that many installed WSHPs do operate
the fan continuously during occupied
hours (i.e., regardless of whether the
compressor is cycled on or off). At the
time of publication of the August 2022
NOPR, there were no WSHP industry
consensus test procedures that included
IEER. However, at this time, DOE
surmises that the method in section
6.3.6.4 of AHRI 600–2023, which
assumes the fan does not run when the
compressor is cycled off, represents
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industry consensus on the appropriate
method for determining IEER for
WSHPs. At this time, DOE has
concluded that it lacks sufficient
information to justify deviating from the
approach in AHRI 600–2023 regarding
fan operation. DOE is therefore
incorporated by reference the cyclic
degradation equation from section
6.3.6.4 of AHRI 600–2023 into its
amended test procedure in this final
rule.
2. ACOP
DOE’s current test procedure for
WSHPs measures heating-mode
performance in terms of the COP metric.
COP is a full-load heating efficiency
metric for WSHP water-loop
applications, meaning that it represents
the heating efficiency for a WSHP
operating at its maximum capacity at an
EWT that is typical of heating operation
in water-loop applications. DOE’s
current test procedure specifies an EWT
of 68 °F for measuring COP. 10 CFR
431.96.
In the August 2022 NOPR, DOE
discussed its understanding that while
in the past water-loop temperatures
were maintained at temperatures above
60 °F via heat provided by a system
boiler, in current practice WSHP
installations are typically controlled to
allow water-loop temperatures to drop
to temperatures closer to 50 °F. 87 FR
53302, 53316. Therefore, while the
current EWT of 68 °F for the COP metric
may have been more representative of
how WSHP systems were controlled in
the past (i.e., with a boiler maintaining
water-loop temperatures above 60 °F),
DOE tentatively determined in the
August 2022 NOPR that the EWT
specified for determining COP should
be no higher than the lowest EWT used
in the IEER metric, which is 55 °F (for
the 25-percent load point). Id.
Therefore, DOE tentatively concluded in
the August 2022 NOPR that the COP
metric would be more representative of
water-loop WSHP applications if based
on an EWT of 55 °F. Id. at 87 FR 53317.
Accordingly, in the August 2022 NOPR,
DOE proposed use an EWT of 55 °F for
the COP metric in appendix C1. Id.
DOE also considered whether an EWT
below 55 °F, specifically 50 °F, might be
more representative for determining
COP, depending upon typical heating
conditions for water-loop WSHPs. Id.
However, DOE noted in the August 2022
NOPR that it lacked data or evidence
indicating that 50 °F would be a more
representative heating EWT than 55 °F
for WSHPs. Id.
Additionally, DOE proposed to
include an alternate method in
appendix C1 that would allow
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manufacturers to determine COP at the
proposed EWT of 55 °F by interpolation
from results of testing at the EWTs
specified in Table 2 of ISO 13256–
1:1998 (i.e., 50 °F and 68 °F). Id. In the
August 2022 NOPR, DOE presented the
results of investigative testing
demonstrating that COP calculated from
interpolated values of cooling capacity
and total power differed from measured
COP by an average of less than 1
percent. Id. Based on these test results,
DOE tentatively concluded that
determining COP at 55 °F via
interpolation from testing at the ISO
13256–1:1998 EWTs (in accordance
with DOE’s proposed test procedure)
would provide appropriately
representative results that are
comparable to testing at 55 °F. Id.
In summary, DOE proposed in section
6.2 of the proposed appendix C1 to
allow that COP for WSHPs can be
calculated from either of two methods:
(1) ‘‘option A’’—testing at 55 °F; or (2)
‘‘option B’’—interpolation of heating
capacity and power values based on
testing in accordance with the proposed
test procedure at EWTs of 50 °F and
68 °F. Id.
DOE sought comment and data on the
representativeness of 55 °F as the EWT
condition for determining COP. Id.
Specifically, DOE requested feedback
and data on whether a lower EWT, such
as 50 °F, would be more representative
of heating operation of WSHPs. Id. DOE
stated that it would further consider any
alternate EWT suggested by comments
in developing any final rule. Id. DOE
also requested comment on the proposal
to allow determination of COP using the
two different methods. Id. Specifically,
DOE sought feedback on the proposed
method for calculating COP via
interpolation and on whether this
approach would serve as a potential
burden reducing option as compared to
testing at 55 °F. Id.
In response to the August 2022 NOPR,
ClimateMaster recommended that DOE
maintain use of the ISO 13256–1:1998
EWT of 68 °F as the basis for the
regulated metric, asserting that this
would take into account the fact that
building designers select and simulate
system equipment and performance
based upon data published by
manufacturers. (ClimateMaster, No. 22
at p. 5) ClimateMaster stated that the
EWT used for heating operation in a
WSHP is dependent on many factors
(e.g., building design, location, system
design, system operation, and building
occupancy or use) and that, due to these
factors, there are no data available to
determine the representativeness of
55 °F as the EWT condition in contrast
to a lower or higher EWT. (Id.)
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Regarding DOE’s proposal to allow
two different options for determining
COP, ClimateMaster stated that it
disagreed with both proposed options
for allowing determination of COP,
stating that neither option would
provide a reduction in burden
considering DOE’s proposal to change
entering air temperatures. (Id.)
ClimateMaster further commented that
the proposed changes would require the
industry to test under multiple
standards to meet both certification
programs. (Id. at pp. 5–6)
MIAQ recommended aligning the
EWT conditions with the latest edition
of ISO standard EWT conditions.
(MIAQ, No. 23 at p. 4)
WaterFurnace commented that nonexpansion valve products typically
cannot operate below an EWT of 60 °F
and that a percentage of the market has
always had limited water temperature
range capability. (WaterFurnace, No. 20
at p. 7) WaterFurnace also commented
that adopting ISO 13256–1 and AHRI
600 would solve the issue of COP test
temperature. (Id.)
Regarding considerations for selecting
the EWT condition for determining
COP, FHP commented that the use of
higher EWTs is focused on water loop
condition only and the move to
electrification for commercial buildings
will shift commercial designs for water
source products toward ground coupled
systems, driving temperatures closer to
ISO 13256–1 ground loops conditions
(e.g., 32 °F entering water). (FHP, No. 26
at p. 4)
NYSERDA agreed with DOE’s
proposal to adopt an EWT of 55 °F or
lower, stating that geothermal
technology research and development
undertaken by NYSERDA and the
Cleaner, Greener Communities Program
in Syracuse revealed the average EWT
for the average mixed-use building was
48 °F when heating. (NYSERDA, No. 21
at p. 3) NYSERDA commented that it
had collected data supporting that the
average building consistently uses
EWTs of 55 °F or lower and presented
these data in a table that suggested the
current EWT test condition of 68 °F is
unrepresentatively high. (Id. at pp. 3–4)
In response to WaterFurnace’s
comment that some products cannot
operate below 60 °F, DOE notes that the
heating temperatures in section 6.2.1 of
AHRI 600–2023 include temperatures
below 60 °F, at 50 °F and 32 °F.
Inclusion of these EWTs in the updated
industry standard suggests that there is
industry agreement that WSHPs can
generally operate below 60 °F. DOE is
not aware of any WSHPs that cannot
operate in heating mode at 50 °F and
notes that the issue was not raised in
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AHRI 600 committee meetings after the
August 2022 NOPR. As discussed earlier
in this section, comments from other
interested parties also supported the use
of a lower temperature.
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023. Section 6.2.1
of AHRI 600–2023 includes EWTs of
68 °F, 50 °F, and 32 °F for measuring
COP. Additionally included in section
6.4.5 of AHRI 600–2023 is a new metric,
ACOP, which is only measured at 50 °F.
This new metric is similar to COP but
includes provisions accounting for
system pump power, which better
accounts for total energy use of WSHPs
and aligns with changes made to the
cooling efficiency metric (see section
III.F.3 of this document for more
details). Further, ACOP is included in
section 7.1 of AHRI 600–2023 as a
minimum requirement for published
ratings. Therefore, ACOP, measured at
50 °F, is the heating metric required for
WSHPs according to AHRI 600–2023.
Having been developed through an
industry consensus process subsequent
to the timing of the August 2022 NOPR
comment period, DOE surmises that
ACOP tested at an EWT of 50 °F
specified in AHRI 600–2023 represents
the prevailing industry consensus
regarding the most appropriate metric
for measuring heating performance.
Therefore, in this final rule, DOE is
incorporating by reference sections 6.2.1
and 6.4.5 of AHRI 600–2023 into
appendix C1 adopting the ACOP metric,
tested at an EWT of 50 °F.
DOE notes that no heating EWT of
55 °F is included in section 6.2.1 of
AHRI 600–2023 and, instead, Table 8 of
the document maintains the same
heating test temperatures as ISO 13256–
1:1998 (68 °F, 50 °F, and 32 °F).
Therefore, due to the lack of support of
a test temperature at 55 °F, the exclusion
of that temperature in AHRI 600–2023,
and the support for aligning with ISO
13256–1:1998 test temperatures (which
include 50 °F), DOE is finalizing the
ACOP metric based on a test at 50 °F,
consistent with AHRI 600–2023.
As discussed, use of the amended test
procedure in appendix C1 and rating to
ACOP at 50 °F are not required until the
compliance date of amended standards
denominated in terms of ACOP, should
DOE adopt such standards. DOE is
defining ‘‘ACOP’’ in 10 CFR 431.92 as
the ratio of the heating capacity to the
power input, including system pump
power, for water-source heat pumps and
that ACOP is expressed in watts per
watt and determined according to
appendix C1 of subpart F of part 431.
Because AHRI 600–2023 requires a
heating test at 50 °F, there is no need for
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an interpolation method to determine
ACOP at an EWT different from the
tested EWT, and, therefore, AHRI 600–
2023 includes no such interpolation
method for ACOP. Correspondingly,
because DOE is incorporating by
reference AHRI 600–2023 into appendix
C1 to require a heating test be
conducted at 50 °F and to adopt the
ACOP metric based on the same EWT,
the COP interpolation method proposed
in the August 2022 NOPR is no longer
applicable. Therefore, DOE is not
adopting an interpolation method for
determining ACOP in this final rule.
3. Optional Representations
In the August 2022 NOPR, DOE
proposed provisions to allow for
optional representations of EER
conducted per the proposed test
procedure (sections 2 through 4 and 7
of proposed appendix C1) at the fullload and part-load EWT conditions
specified in Table 1 of ISO 13256–
1:1998 (i.e., full load tests at 86 °F, 77 °F,
and 59 °F and part-load tests at 86 °F,
68 °F, and 59 °F). 87 FR 53302, 53314.
Additionally, DOE proposed provisions
to provide for optional representations
of COP based on testing conducted per
the proposed test procedure (sections 2
through 4 and 7 of proposed appendix
C1) at the full-load and part-load EWT
conditions specified in Table 2 of ISO
13256–1:1998 (i.e., 68 °F, 50 °F, 41 °F,
and 32 °F). Id. at 87 FR 53317.
AHRI 600–2023 includes provisions
allowing for optional representations of
EER and COP in sections 6.3.12 and
6.4.7, respectively. Optional
representations can be made at any of
the cooling and heating full-load and
part-load EWT conditions in Table 8 of
AHRI 600–2023. DOE notes that the
AHRI 600–2023 includes new metrics
applied energy efficiency ratio
(‘‘AEER’’) and ACOP (see section III.E.2
of this final rule for more details about
ACOP). Each of these metrics include a
power adder representing system pumps
and the adder for AEER also includes
cooling tower power. DOE notes that
AHRI 600–2023 does not have
provisions for optional representations
of these metrics and instead requires
them to be published. The optional
representations of EER and COP allowed
for by AHRI 600–2023 do not include
the power adder for system pumps and
cooling tower power.
As discussed in section III.E.1 and
III.E.2 of this final rule, DOE is
incorporating by reference AHRI 600–
2023 for IEER and ACOP into appendix
C1 as the cooling and heating metrics
for WSHPs. The IEER metric as
determined according to AHRI 600–
2023 includes a power adder for system
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pumps and cooling tower power. DOE
notes that the metrics it is adopting are
intended to best reflect WSHP
performance, using representative EWTs
and including power for all components
that are needed for operation of WSHP
systems in a representative application
(i.e., external pumps and cooling
towers). Optional representations of EER
and COP are intended to provide more
information to consumers across a range
of temperature conditions such that
performance can be assessed for specific
applications. DOE is adopting the
provisions for optional representations
of EER and COP from sections 6.3.12
and 6.4.7 from AHRI 600–2023 by
incorporating by reference AHRI 600–
2023 into appendix C1. These
provisions allow optional
representations to be made consistent
with AHRI 600–2023 at full-load or partload at any of the standard rating
conditions for WSHPs (i.e., 86 °F, 68 °F,
and 50 °F for cooling and 68 °F, 50 °F,
and 32 °F for heating). DOE notes that
these temperatures vary slightly from
the proposals in the August 2022 NOPR
for optional representations, but
represent the same intent of allowing for
optional representations of a range of
operating conditions. Having been
developed through an industry
consensus process subsequent to the
timing of the August 2022 NOPR
comment period, DOE has determined
that the EWTs specified in AHRI 600–
2023 represent the prevailing industry
consensus regarding the most
appropriate EWTs for optional
performance test points.
4. Entering Air Conditions
The current DOE WSHP test
procedure references ISO 13256–1:1998,
which specifies in Table 1 that EER is
measured with entering air at 27 °C
(80.6 °F) dry-bulb temperature and 19 °C
(66.2 °F) wet-bulb temperature and in
Table 2 that COP is measured with
entering air at 20 °C (68 °F) dry-bulb
temperature and 15 °C (59 °F) wet-bulb
temperature.
In the August 2022 NOPR, DOE
proposed to use the entering air
conditions in Table 6 of AHRI 340/360–
2022, which specify that cooling tests
are measured with entering air at 80 °F
dry-bulb temperature and 67 °F wet-bulb
temperature heating tests are measured
with entering air at 70 °F dry-bulb
temperature and a maximum of 60 °F
wet-bulb temperature. 87 FR 53302,
53318. DOE discussed in the August
2022 NOPR that the entering air
conditions specified in AHRI 340/360–
2022 are similar to the conditions
specified in ISO 13256–1:1998 and ISO
13256–1:2021, differing for cooling by
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0.6 °F for dry-bulb temperature and
0.8 °F for wet-bulb temperature and for
heating by 2 °F for dry-bulb temperature
and 1 °F for wet-bulb temperature. Id.
DOE surmised that these differences are
likely due to the conditions in ISO
13256–1 (1998 and 2021 versions) being
specified in terms of degrees Celsius,
whereas the conditions in AHRI 340/
360–2022 are specified in degrees
Fahrenheit. Id. DOE also noted that the
entering air conditions specified in
AHRI 340/360–2022 are the same as in
previous versions of AHRI 340/360,
including AHRI 340/360–2007, which is
referenced in the current DOE test
procedure for CUAC/HP equipment. Id.
Further, the most common application
for WSHPs (and the application DOE
understands that the WSHP industry is
intending to represent via use of the
IEER metric in AHRI 600) is commercial
buildings, similar to CUAC/HP
equipment. Id. Therefore, DOE
tentatively determined in the August
2022 NOPR that the entering air
conditions in AHRI 340/360–2022 are
appropriately representative of the
average conditions in which WSHPs
operate in the field. Id.
DOE requested comment on its
proposal to specify use of the cooling
entering air conditions from AHRI 340/
360–2022 (i.e., 80 °F dry-bulb
temperature and 67 °F wet-bulb
temperature) and the heating entering
air conditions from AHRI 340/360–2022
(i.e., 70 °F dry-bulb temperature and a
maximum of 60 °F wet-bulb
temperature). Id.
In response to the August 2022 NOPR,
ClimateMaster recommended that DOE
keep the existing entering air
temperature conditions for both heating
and cooling tests from ISO 13256–
1:1998 to avoid the requirement to test
equipment under two separate
certification programs. (ClimateMaster,
No. 22 at p. 6) ClimateMaster stated that
the use of 80.6 °F and 66.2 °F entering
air conditions for cooling would be
more conservative (i.e., result in lower
efficiency ratings) than those at 80 °F
and 67 °F as specified in AHRI 340/360–
2022. (Id.)
WaterFurnace commented that
adopting ISO 13256 and AHRI 600
would solve the issue of which entering
air conditions to use. (WaterFurnace,
No. 20 at p. 7) WaterFurnace further
commented that DOE’s proposal would
essentially require all new testing due to
the different entering air conditions.
(Id.) WaterFurnace stated that the
existing entering air conditions of
AHRI/ISO 13256 could be used and
would result in a more conservative
performance prediction. (Id.)
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MIAQ commented that it generally
agrees with DOE’s proposal to adopt the
entering air conditions in AHRI 340/
360–2022. (MIAQ, No. 23 at p. 5)
As discussed, DOE is adopting
provisions for determining IEER and
ACOP by incorporating by reference
AHRI 600–2023 into appendix C1. The
entering air conditions in section 6.2.1
of AHRI 600–2023 align with the
entering air conditions specified in
AHRI 340/360–2022 (and therefore align
with DOE’s August 2022 NOPR
proposal). DOE surmises that inclusion
of the AHRI 340/360–2022 entering air
conditions in AHRI 600–2023 indicates
industry consensus with these test
conditions. Therefore, DOE is adopting
provisions for determining IEER and
ACOP consistent with AHRI 600–2023,
including entering air conditions of
80 °F dry bulb and 67 °F wet bulb for
cooling tests and 70 °F dry bulb and a
maximum of 60 °F wet bulb for heating
tests, in this final rule, by incorporating
by reference into appendix C1 section
6.2.1 of AHRI 600–2023.
F. Test Method
1. Airflow and External Static Pressure
a. Fan Power Adjustment and Required
Air External Static Pressures
For ducted units, the current DOE
WSHP test procedure, which
incorporates by reference ISO 13256–
1:1998, specifies a fan power adjustment
calculation that does not account for fan
power used for overcoming external
resistance. As a result, the calculation of
efficiency includes only the fan power
required to overcome the internal
resistance of the unit. In addition, ISO
13256–1:1998 does not specify ESP
requirements for ducted equipment,
instead allowing manufacturers to
specify a rated ESP. In the August 2022
NOPR, DOE proposed provisions to
reflect fan power to overcome a
representative ESP when calculating
efficiency for ducted units to account
for the impacts of ESP typically
encountered in the field. 87 FR 53302,
53321. DOE determined that, to best
reflect field operation, ducted WSHPs
should be tested with minimum ESPs,
the power for overcoming ESP should
be included in efficiency calculations,
and all equipment should be tested with
an ESP upper tolerance. Id. DOE
determined that the method in AHRI
340/360–2022 is more representative of
field energy use than the methods used
in ISO 13256–1:1998 for WSHPs. Id.
DOE proposed to adopt AHRI 340/360–
2022 for WSHPs, including section
6.1.3.3 and Table 7 of AHRI 340/360–
2022, which specify minimum ESPs for
ducted units, a tolerance on ESP of
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¥0.00/+0.05 in H2O, and no fan power
adjustment. Id. DOE requested comment
on the proposal to adopt provisions
from AHRI 340/360–2022 such that for
ducted units testing would be
conducted within tolerance of the AHRI
340/360–2022 minimum ESP
requirements, and efficiency ratings
would include the fan power measured
to overcome the tested ESP. Id. at 87 FR
53322.
In response to the August 2022 NOPR,
ClimateMaster recommended that DOE
keep the existing ISO 13256–1:1998
standard and develop an IEER rating per
AHRI 600 that offers provisions for
complying with the required minimum
external pressure as given in AHRI 340/
360–2022. (ClimateMaster, No. 22 at p.
6) ClimateMaster stated that there are
multiple reasons why the current ISO
13256–1:1998 standard excludes
external static pressure, including that
the methodology was created to rate
different motor options for varying static
requirements in the market space,
which is especially problematic with
non-variable speed motors as they are
limited in output capability over a
narrow static range. (Id.) MIAQ
recommended DOE reference the ESP
requirements in the latest edition of ISO
13256–1. (MIAQ, No. 23 at p. 5)
WaterFurnace commented that
supporting ISO 13256 and AHRI 600
would solve the issue and that it
believes the required information can be
calculated from AHRI/ISO 13256 data
without retesting. (WaterFurnace, No.
20 at p. 7) WaterFurnace additionally
commented that the minimum ESP
requirements specified in AHRI 340/360
are adequate for most commercial
WSHPs because most are installed with
common plenum returns with little to
no return ductwork. (Id.)
FHP recommended that instead of
requiring testing at minimum ESP
requirements, DOE develop a revised
fan power adjustment that incorporates
accurate fan efficiencies and allows
testing at a range of ESPs but adjusts fan
performance to reflect performance at
the minimum ESPs specified in AHRI
340/360–2022. (FHP, No. 26 at pp. 3–4)
FHP asserted that such a revised fan
power adjustment would allow for
variations in tested ESP to achieve rated
airflow to account for limitations of the
fan-motor combination and variation in
manufacturing tolerances, while still
ensuring ratings are based on an ESP
more representative than zero ESP. (Id.)
The Joint Commenters supported
DOE’s proposal that WSHPs be tested at
the ESPs specified in the proposed test
procedure. (Joint Commenters, No. 27 at
p. 2) The Joint Commenters stated that
maintaining the current test procedure,
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which applies a correction factor that
adjusts fan power measured at the
manufacturer-specified ESP is adjusted
down to reflect fan power at zero ESP
and incentivizes testing with higherthan-representative ESPs, would be
inconsistent with the recommendation
in the ASRAC Fans and Blowers
Working Group term sheet to capture
fan energy more fully across commercial
HVAC product categories. (Id.)
NEEA supported DOE’s proposal to
include additional fan energy in the
WSHP efficiency metric, but also
encouraged DOE to consider increasing
the proposed ESP requirements to be
more representative of current industry
practice. (NEEA, No. 25 at pp. 2–3)
NEEA stated that during the 2015
CUAC/HP energy conservation standard
ASRAC negotiations, DOE’s energy use
analysis used ESP values 2 to 3 times
higher than the ESP requirements in the
current test procedure because DOE
found the values to be more realistic
and representative of field conditions.
(Id. at p. 3) NEEA further recommended
that DOE consider aligning WSHP ESP
requirements with the updated CUAC/
HP ESP requirements when they are
finalized by the ASRAC Working Group.
(Id.)
With regards to these comments, DOE
notes that section 5.5.1 of AHRI 600–
2023 includes ESPs to be used for
testing for ducted units. The ESPs are
equivalent to those outlined in AHRI
340/360–2022 for units less than 75,000
Btu/h cooling capacity, but the ESPs for
units above 75,000 Btu/h cooling
capacity (i.e., 0.75 in. H2O for units from
75,000 Btu/h to 134,000 Btu/h; 1.00 in.
H2O for units from 135,000 Btu/h to
280,000 Btu/h; and 1.50 in. H2O for
units greater than 280,000 Btu/h) are
significantly higher than those in AHRI
340/360–2022 and align with the ESP
requirements recommended in the
ACUAC and ACUHP Working Group TP
Term Sheet. (See Document No. 65 in
Docket No. EERE–2022–BT–STD–0015)
Section 5.7 of AHRI 600–2023 also
includes a tolerance of ESP of ¥0.00/
+0.05 in H2O and sections 6.3 and 6.4
of AHRI 600–2023 include no fan power
adjustment. DOE notes also that the
approach set forth in AHRI 600–2023 is
mostly consistent with the approach
proposed in the August 2022 NOPR,
with the only difference being higher
ESP requirements for units greater than
75,000 Btu/h in cooling capacity. DOE
has determined that the inclusion of
ESP requirements, an ESP tolerance,
and no fan power adjustment in AHRI
600–2023 represents industry consensus
that these provisions provide the most
appropriate and representative method
for testing WSHPs. As discussed in
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section III.D of this final rule, DOE is
incorporating by reference AHRI 600–
2023 into appendix C1, including these
ESP provisions. DOE notes that
including these provisions is consistent
with commenters’ suggestions to adopt
AHRI 600.
Regarding the higher ESP
requirements for units with a cooling
capacity greater than 75,000 Btu/h,
adopting these values is consistent with
NEEA’s recommendation to align with
the recommendations from the ASRAC
Working Group for test procedures for
CUAC/HPs. These ESP requirements
were developed as part of a joint effort
between manufacturers, efficiency
advocates, utilities, and DOE to create a
more representative efficiency metric for
CUACs/HPs. DOE understands that
WSHPs greater than 75,000 Btu/h are
installed in similar applications to
CUACs/HPs and, as such, DOE finds the
AHRI 600–2023 ESP requirements to be
representative for WSHPs with a cooling
capacity greater than 75,000 Btu/h.
DOE notes that the ACUAC and
ACUHP Working Group TP Term Sheet
recommends an ESP requirement of 0.75
in. H2O for units with a cooling capacity
between 65,000 to 135,000 Btu/h, while
the lower capacity limit for this
requirement in section 5.5.1 of AHRI
600–2023 is 75,000 Btu/h. Based on
discussions in AHRI 600 committee
meetings, DOE understands that there
are WSHP model lines that span up to
6 tons that typically use fan/motor
combinations that are designed for
lower ESP applications and cannot
operate at the rated airflow at an ESP as
high as 0.75 in. H2O. Therefore, AHRI
600–2023 specifies a lower capacity
limit for this ESP requirement of 75,000
Btu/h rather than 65,000 Btu/h so that
these 6-ton models are tested with a
more representative ESP. DOE
understands this issue to be unique to
WSHPs and does not apply to ACUACs
and ACUHPs, for which models with a
cooling capacity between 65,000 Btu/h
and 75,000 Btu/h typically have
different designs than three-phase
ACUACs and ACUHPs (which typically
have comparable designs to CAC/HPs)
and are typically designed for
installations for which an ESP of 0.75
in. H2O is representative. Therefore, in
this final rule, DOE is incorporating by
reference the requirements specified in
Table 7 of section 5.5.1 of AHRI 600–
2023 for all WSHPs with a cooling
capacity less than 760,000 Btu/h.
With regard to comments from
ClimateMaster and FHP expressing
concern over ability of different fan/
motor combinations to test at an ESP
requirement at the rated airflow, DOE
notes that this issue is addressed by the
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provisions for (1) non-standard highstatic indoor fan motors and fan/motor
combinations proposed in the August
2022 NOPR, included in section D4 of
AHRI 600–2023 (discussed in section
III.G.3 of this final rule); and (2) nonstandard low-static motors included in
sections 3.2.30 and 5.7.4.3 of AHRI 600–
2023 (discussed in section III.F.12 of
this final rule). DOE has concluded that
the inclusion of ESP requirements and
provisions in AHRI 600–2023 for (1)
non-standard high-static indoor fan
motors and fan/motor combinations and
(2) non-standard low-static motors
reflect industry consensus that these
provisions provide an appropriate
method for testing and rating WSHPs.
DOE notes that section 5.5.1.2 of
AHRI 600–2023 specifies a minimum
ESP of 0.5 in. H2O for residential
representations, but that the residential
representations have not yet been fully
developed for WSHPs (see section
III.A.2 of this document for more
details). DOE will continue to work with
AHRI 600 committee to develop
provisions for determining such ratings.
b. Setting Airflow and ESP
DOE’s current WSHP test procedure
does not include provisions on how to
simultaneously set airflow and ESP
because there are no required ESPs for
testing. Because DOE proposed to
include minimum ESPs in its test
procedure in the August 2022 NOPR, it
also proposed provisions to address
how to simultaneously set airflow and
ESP. 87 FR 53302, 53322–53324. The
proposals were broken into three
groups:
(1) For ducted units with
continuously variable speed fans, DOE
proposed to use relevant provisions
from AHRI 340/360–2022 in sections
6.1.3.3 through 6.1.3.5.
(2) For ducted units with discrete step
fans, DOE proposed instructions for
setting the fan speed in the scenario in
which: (1) tolerances for airflow and
ESP could not be met simultaneously,
and (2) adjacent fan control settings
result in airflow or ESP too low at the
lower fan control setting and too high at
the higher fan control setting.
(3) For non-ducted units, DOE
proposed units to be tested with a target
ESP of 0.00 in H2O within a tolerance
of ¥0.00/+0.05 in H2O.
Id.
For all three types of units, the
proposed airflow tolerance was 3
percent. Id.
DOE requested comment on the
proposed adoption of provisions from
AHRI 340/360–2022 for setting airflow
and ESP for testing WSHP units with
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continuously variable speed fans. Id. at
87 FR 53323. DOE also requested
comment on its proposed instructions
(distinct from provisions in AHRI 340/
360–2022) for setting airflow and ESP
for ducted WSHP units with discretestep fans. Id. Finally, DOE requested
comment on its proposal for setting
airflow and ESP for non-ducted WSHP
units. Id. at 87 FR 53324.
In response to the August 2022 NOPR,
ClimateMaster recommended that DOE
work with industry to create a national
deviation of ISO 13256–1:1998 that
adopts the applicable parts of AHRI
340/360 for fully variable-speed motor
systems and systems with adjustable
sheaves, while still providing separate
provisions for setting airflow for fan
motor systems that are not continuously
variable. (ClimateMaster, No. 22 at p. 7)
ClimateMaster stated that it disagrees
with the use of AHRI 340/360–2022 for
all indoor blower systems, arguing that
these provisions were developed to
accommodate only continuously
variable-speed blower systems and
asserted that the proposed 3 percent
tolerance would not be feasible for
larger WSHP systems without
continuously variable motors or WSHPs
with discrete-step or constant volume
fan motors. (Id. at p. 6) ClimateMaster
stated that Table B1 of the AHRI WSHP
Operations Manual 9 specifies a 5
percent airflow tolerance for discretestep motors. (Id. at p. 7) ClimateMaster
further commented that the provisions
for setting airflow in AHRI 210/240–
2023 are more appropriate for the fan
motors utilized in most WSHP systems
(i.e., not continuously variable), stating
that the AHRI 210/240–2023 provisions
use manufacturer-specified fan motor
settings and allow airflow to decrease to
10 percent below the target airflow. (Id.
at p. 7)
FHP commented that the combination
of a minimum ESP requirement and a 3
percent airflow tolerance would require
additional testing and significant design
constraints and changes at the
component level for WSHPs with directdrive motors and questioned whether a
3 percent airflow tolerance at a
minimum ESP requirement is
technologically feasible. (FHP, No. 26 at
p. 4) FHP further commented that units
with constant-torque direct-drive fan
motors (e.g., permanent split capacitor
(‘‘PSC’’) motors, electrically
commutated motors (‘‘ECMs’’)) do not
allow for adjustments to airflow without
adjustments to ESP, making it difficult
9 DOE notes that the AHRI WSHP Certification
Operations Manual is available at: https://
www.ahrinet.org/sites/default/files/2022-06/WSHP_
OM.pdf (Last accessed April 25, 2023).
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to consistently hit the airflow target
within 3 percent. (Id.) FHP also noted
that the AHRI WSHP Operations
Manual allows for adjustments to ESP to
meet a 5-percent airflow tolerance for
these systems. (Id.)
WaterFurnace commented that
adopting ISO 13256 and AHRI 600
would solve the issue. (WaterFurnace,
No. 20 at p. 8) WaterFurnace stated that
a test procedure for models fans with
ECMs would have to be added to AHRI
340/360 because the standard does not
address setting airflow and ESP for such
models, which it stated are typical for
smaller WSHPs. (Id.) MIAQ
recommended DOE reference the latest
edition of ISO 13256–1, stating that this
standard is the industry test procedure
currently used by manufacturers and
laboratories for WSHP testing. (MIAQ,
No. 23 at p. 5)
ClimateMaster stated that the WSHP
Operations Manual covers available
provisions with what they consider to
be a proper allowance for airflow
variation and that non-ducted WSHPs
are available with motors that have
multiple set speeds either through
software or by utilizing a tapped motor
winding. (ClimateMaster, No. 22 at p. 7)
ClimateMaster stated that these
provisions are slightly different from
those proposed in the August 2022
NOPR and requested further
clarification to the meaning of ‘‘as close
as possible’’. (Id.) ClimateMaster noted
that they expect that the speed tap
specified by the manufacturer would be
utilized and that, if this is the case, then
there should not be any concern if the
airflow is ‘‘as close as possible’’ to the
rated point. (Id.)
In response to the comment from
ClimateMaster, DOE notes that the ‘‘as
close to the target as possible’’ language
in the August 2022 NOPR is used in
situations when the airflow and ESP
requirements cannot be simultaneously
met. Specifically, for non-ducted units,
the August 2022 NOPR provisions
specify that if airflow and ESP
requirements cannot be met
simultaneously, the ESP requirement
takes precedence (i.e., ESP must be
maintained within tolerance) and the
airflow is maintained as close as
possible to the target airflow (but
outside of tolerance). Section 5.8 of
AHRI 600–2023 similarly specifies that
in this situation the ESP must be
maintained within tolerance and that
there is no condition tolerance for
airflow.
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. This includes sections 5.7 and 5.8
of AHRI 600–2023. This language
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includes provisions generally consistent
with provisions outlined in the August
2022 NOPR, specifically a tolerance of
3 percent for setting airflow, separate
provisions for continuously variable
speed fans and discrete-step fans, and a
method for non-ducted units. Section
5.7 of AHRI 600–2023 also includes
provisions for setting airflow and ESP
for constant-volume fans, but DOE notes
that these provisions were not proposed
in the August 2022 NOPR and are
consistent with provisions in appendix
M1 for central air conditioners and heat
pumps.
Regarding commenter’s concerns
about models with non-continuouslyvariable fan motors, the comments
received suggest that the commenters
interpreted DOE’s proposal to be
adopting the provisions for setting
airflow and ESP in AHRI 340/360–2022
without modification. However, as
discussed in the August 2022 NOPR,
DOE proposed additional provisions to
allow a larger airflow tolerance for
models with non-continuously-variable
fan motors that align more closely with
the provisions for setting airflow in
AHRI 210/240–2023 (as recommended
by ClimateMaster). See 87 FR 53302,
53323. Similar provisions are included
in AHRI 600–2023. DOE has concluded
that these provisions, along with the
previously mentioned provisions for
constant-volume fans, provide an
appropriate method for setting airflow
and ESP for WSHPs of all fan motor
types.
DOE has determined that
incorporating by reference AHRI 600–
2023 for setting airflow and ESP
addresses commenters’ concerns. DOE
surmises that the inclusion of these
provisions for setting airflow and ESP in
AHRI 600–2023 indicates industry
consensus that these provisions provide
an appropriate method for testing
WSHPs. Therefore, in this final rule,
DOE is incorporating by reference into
appendix C1 sections 5.7 and 5.8 of
AHRI 600–2023 for setting airflow and
ESP.
c. Coil-Only Units
For units without integral fans (i.e.,
coil-only units), section 4.1.3.1 of ISO
13256–1:1998, which is referenced in
the current DOE WSHP test procedure,
specifies that a fan power adjustment be
added to the total power of the unit, and
that this value be added to the heating
capacity and subtracted from the
cooling capacity. The fan power
adjustment equation to determine fan
power estimates fan power to overcome
internal pressure drop within the unit,
using a similar methodology to the fan
power adjustment equation used for
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units with integral fans to subtract out
the fan power to overcome ESP. As
discussed in section III.F.1.a of this final
rule, the amended test procedure
adopted in appendix C1 (incorporating
by reference AHRI 600–2023) does not
use a fan power adjustment for units
with integral fans and requires testing at
representative minimum external static
pressures and ratings reflect
performance at the tested ESP.
As part of DOE’s proposal to adopt
AHRI 340/360–2022, in the August 2022
NOPR, DOE proposed to adopt sections
6.1.1.6, 6.1.3.3 and 6.1.3.4 of AHRI 340/
360–2022, which contain provisions for
how to test coil-only units. 87 FR 53302,
53322. In particular, section 6.1.3.3.4
specifies that coil-only units shall not
have a pressure drop exceeding 0.30 in
H2O for the full load cooling test.
Section 6.1.3.4.6 outlines that coil-only
units are to be tested at manufacturer
specified airflow rates, not exceeding
450 standard cubic feet per minute
(‘‘scfm’’) per ton of cooling capacity and
if there is no manufacturer specified
airflow rate, they are to be tested at 400
scfm per ton of rated cooling capacity.
Finally, section 6.1.1.6 specifies that
1,250 Btu/h per 1,000 scfm is to be
removed from the measured cooling
capacity and 365 Watts (‘‘W’’) per 1,000
scfm is to be added to the measured
power for ducted coil-only units.
AHRI 600–2023 includes provisions
for coil-only units, which are defined as
units without an indoor fan or separate
designated air mover. The provisions
are nearly identical to those proposed in
the August 2022 NOPR. Section 5.5.2
specifies that coil-only units shall not
have a pressure drop exceeding 0.30 in
H2O for the full-load cooling test.
Section 5.6.3 outlines that coil-only
units are to be tested at manufacturer
specified airflow rates, not exceeding
450 scfm per ton of cooling capacity and
if there is no manufacturer specified
airflow rate, they are to be tested at 400
scfm per ton of rated cooling capacity.
Finally, sections 6.3.3.4 and 6.4.3.4
specify that for ducted coil-only units,
measured capacity is adjusted by 1,245
Btu/h per 1,000 scfm (subtracted from
cooling capacity and added to heating
capacity) and measured power is
adjusted by adding 365 W per 1,000
scfm. Additionally, AHRI 600–2023
includes provisions for non-ducted coil
only units—for these, the values are 940
Btu/h per 1,000 scfm for capacity
adjustment and 275 W per 1,000 scfm
for power adder respectively.
DOE notes that the provisions
outlined in AHRI 600–2023 are
consistent with those proposed in the
August 2022 NOPR except for a minor
deviation in the capacity reduction for
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ducted coil-only units and the inclusion
of provisions for non-ducted coil-only
units. Based on discussion in AHRI 600
committee meetings, DOE understands
that non-ducted coil-only WSHP models
exist on the market, and therefore, DOE
has determined that the addition of
provisions for testing such units is
warranted. As discussed in section III.D
of this final rule, DOE is incorporating
by reference AHRI 600–2023 into
appendix C1. This includes section
5.5.2, 5.6.3, and 6.3.3.4 of AHRI 600–
2023. DOE notes the inclusion of these
provisions in AHRI 600–2023 indicates
industry consensus with these
provisions and provides an appropriate
method for testing coil-only WSHPs.
Therefore, DOE is incorporating by
reference into appendix C1 the
provisions for coil-only units from AHRI
600–2023 in this final rule.
2. Capacity Measurement
The current DOE WSHP test
procedure, through adoption of section
6.1 of ISO 13256–1:1998, specifies that
total cooling and heating capacities are
to be determined by averaging the
results obtained using two test methods:
the liquid enthalpy test method for the
liquid side tests and the indoor air
enthalpy test method for the air side
tests. 10 CFR 431.96. For non-ducted
equipment, section 6.1 of ISO 13256–
1:1998 includes an option for
conducting the air-side tests using the
calorimeter room test method instead of
the air enthalpy test method. Section 6.1
of ISO 13256–1:1998 also specifies that,
for a test to be valid, the results obtained
by the two methods used must agree
within 5 percent. ANSI/ASHRAE 37–
2009 is similar to the test method in ISO
13256–1:1998. ANSI/ASHRAE 37–2009
requires two capacity measurements for
units with cooling capacity less than
135,000 Btu/h; the first method of
measurement (i.e., the primary method)
is used as the determination of the
unit’s capacity, while the second
measurement (i.e., the secondary
method) is used to confirm rather than
to be averaged with the primary
measurement (see section 10.1 and
Table 1 of ANSI/ASHRAE 37–2009).
In the August 2022 NOPR, DOE
proposed to adopt specific sections of
AHRI 340/360–2022 for use in the
WSHP test procedure, including section
E6, which specifies test methods for
capacity measurement. 87 FR 53302,
53325–53327. Section E6.1 of AHRI
340/360–2022 requires use of the indoor
air enthalpy method specified in section
7.3 of ANSI/ASHRAE 37–2009 as the
primary method for capacity
measurement. This is the measurement
used to determine capacity, as required
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in section 10.1.2 of ANSI/ASHRAE 37–
2009. Section E6.2.2 of AHRI 340/360–
2022 requires use of one of the
applicable ‘‘Group B’’ methods specified
in Table 1 of ANSI/ASHRAE 37–2009 as
a secondary method for capacity
measurement. The group B methods that
are applicable to WSHPs are the outdoor
liquid coil method (similar to the liquid
enthalpy method included in the 1998
and 2021 versions of ISO 13256–1), the
refrigerant enthalpy method, and the
compressor calibration method. Section
E6.4.2 of AHRI 340/360–2022 requires
that the primary and secondary
measurements match for full-load
cooling and heating tests, within 6
percent of the primary measurement. No
match is required between primary and
secondary measurements for part-load
cooling tests. DOE proposed to adopt all
of these provisions by incorporating by
reference AHRI 340/360–2022. Id. at 87
FR 53325. DOE requested comment on
this approach to adopt the provisions in
AHRI 340/360–2022 and ANSI/
ASHRAE 37–2009 regarding primary
and secondary capacity measurements.
Id. at 87 FR 53326.
In response to the August 2022 NOPR,
ClimateMaster commented that it agrees
with the intent of DOE’s proposed
approach but disagrees with some
specifics and recommended that DOE
work with industry to create a national
deviation of ISO 13256–1:1998 that
adopts the provisions of ANSI/ASHRAE
37–2009 for primary and secondary
capacity measurements, with certain
modifications. (ClimateMaster, No. 22 at
pp. 7–8) ClimateMaster commented
additionally that it disagrees with the
provisions in AHRI 340/360–2022 that
only require agreement between the
primary and secondary capacity
measurements for full-load tests. (Id. at
p. 8) ClimateMaster noted that the
current ISO standard allows for a 5
percent tolerance between the two
measurements, and that in its internal
testing ClimateMaster strives for
agreement within 3–4 percent, stating
that anything over that limit indicates
an issue in equipment setup and/or the
measurement system. (Id.)
ClimateMaster commented that
neglecting to include a match
requirement for part-load tests could
lead to inaccurate representations of
system performance. (Id.)
ClimateMaster further commented
that the uncertainty of measurement for
the liquid coil method is lower than for
the indoor air enthalpy method, and
that the WSHP industry considers the
liquid coil method to be the more
accurate measurement method. (Id.)
ClimateMaster also stated that the liquid
coil method does not include the
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limitations regarding refrigerant subcooling that are specified for the
refrigerant enthalpy method (in section
7.5.1.3 of ANSI/ASHRAE 37–2009), and
stated that low values of refrigerant
subcooling are typically seen in partload tests. (Id.) ClimateMaster
commented that it disagrees with
section 7.6.1.2 of ANSI/ASHRAE 37–
2009 because this provision specifies
that the outdoor liquid coil method
cannot be used for outdoor compressor
systems, and therefore makes the
refrigerant enthalpy method necessary
as the secondary capacity measurement
method for such systems. (Id.)
ClimateMaster stated that while it agrees
in theory that the compressor and
associated refrigerant lines will lose
heat when an uninsulated compressor
section is installed outdoors, requiring
the use of the refrigerant enthalpy
method is not representative of installed
outdoor compressor systems because for
testing the outdoor section of a split
WSHP system is installed in the same
psychrometric room as the indoor air
handler. (Id.) ClimateMaster added that
there are currently no specified outdoor
conditions or requirements for
placement of the outdoor unit in a
differently conditioned room and that
the difference between the current
liquid coil method and the proposed
refrigerant enthalpy method is
negligible without specifying conditions
more thoroughly. (Id.) ClimateMaster
further commented that the insulation
requirements in ANSI/ASHRAE 37–
2009 only specify 1 inch of fiberglass
insulation and do not specify a
minimum R-value for the insulation.
(Id.)
In summary, ClimateMaster
recommended that DOE adopt the
indoor air enthalpy method for the
primary capacity measurement, and that
the outdoor coil liquid method be used
for the secondary capacity measurement
if the unit either (1) meets the
requirements of section 7.6.1.2 of ANSI/
ASHRAE 37–2009 using fiberglass
insulation or an equivalent material
with an R-value of 8.0, or (2) is an
outdoor unit installed in the same test
chamber as the indoor coil. (Id.)
ClimateMaster further recommended a
requirement for agreement within 5
percent between primary and secondary
capacity measurements for full-load and
part-load tests. (Id.)
MIAQ commented that DOE’s
proposed approach in the August 2022
NOPR of adopting the provisions in
AHRI 340/360 and ANSI/ASHRAE 37–
2009 regarding primary and secondary
capacity measurements deviates from
the industry test procedure ISO 13256–
1 and therefore will require
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manufactures to retest their products,
resulting in increased burden. (MIAQ,
No. 23 at p. 6)
WaterFurnace commented that
adopting ISO 13256 and AHRI 600
would solve the issue and that the
liquid enthalpy test method is widely
accepted as the most accurate method
for capacity measurement for WSHPs.
(WaterFurnace, No. 20 at p. 8)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into
Appendix C1, including provisions in
Section 5.2 of AHRI 600–2023 regarding
primary and secondary capacity
measurement methods. Specifically,
Section 5.2 states that the indoor air
enthalpy method be used as the primary
measurement of capacity, and that
secondary capacity measurements be
conducting using one of the following
methods: outdoor liquid coil method,
refrigerant enthalpy method, or
compressor calibration method. Section
5.2.2 of AHRI 600–2023 also states that,
when using the outdoor liquid coil
method, the secondary measurement
must agree within 6 percent of the
primary measurement of capacity on all
tests, including part-load tests.
Incorporating by reference this language
addresses comments in response to the
August 2022 NOPR that DOE should
adopt AHRI 600. The provisions in
AHRI 600–2023 also address
ClimateMaster’s concerns about not
having a match for part-load tests
because AHRI 600–2023 does require a
match between primary and secondary
capacity measurements for part-load
tests if the outdoor liquid coil method
is used.
Regarding agreement between primary
and secondary measurements, DOE has
concluded that the requirement in AHRI
600–2023 that secondary capacity
measurements agree within 6 percent of
primary capacity measurements
(consistent with AHRI 340/360–2022,
which DOE proposed to reference in the
August 2022 NOPR) provides a
representative measure of efficiency for
WSHPs.
Regarding ClimateMaster’s concerns
about the outdoor liquid coil method
provisions in ANSI/ASHRAE 37–2009,
DOE notes that section 5.2.2.1.1 of AHRI
600–2023 specifies to follow all
requirements in section 7.6 of ANSI/
ASHRAE 37–2009 when using the
outdoor liquid coil method and does not
include any provisions that deviate from
ANSI/ASHRAE 37–2009 with regard to
outdoor compressor systems or
insulation R-value. Regarding
ClimateMaster’s concern that ANSI/
ASHRAE 37–2009 requires use of the
refrigerant enthalpy method for
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secondary capacity measurements for
systems in which the compressor is
located outdoors, DOE further notes that
for a split system WSHP with the
compressor and liquid coil contained in
the outdoor unit intended for outdoor
installation, shell losses from the
compressor could impact capacity
measurements using the outdoor liquid
coil method but would not impact
capacity measurements using the
refrigerant enthalpy method. Therefore,
at this time, DOE does not have
sufficient evidence or justification to
deviate from the provisions in AHRI
600–2023 regarding the outdoor liquid
coil method and has concluded that
these provisions provide for appropriate
and representative measurements of
efficiency for WSHPs.
Additionally, AHRI 600–2023 was
developed through an industry
consensus process subsequent to the
timing of the August 2022 NOPR
comment period, and DOE surmises that
the capacity measurement approach
specified in section 5.2 of AHRI 600–
2023 sufficiently addresses the concerns
raised in comments to the August 2022
NOPR. Consequently, DOE is
incorporating by reference into
appendix C1 section 5.2 of AHRI 600–
2023 regarding primary and secondary
capacity measurements in this final
rule.
3. Pump Power Adjustment and Liquid
External Static Pressure
ISO 13256–1:1998 does not reflect the
pump power needed to overcome liquid
ESP from the water loop that pipes
water to and from the WSHP. Instead,
section 4.1.4 of ISO 13256–1:1998
includes a pump power adjustment
(which assumes a pump efficiency of
0.3 for all units) to be applied such that
only the pump power required to
overcome the liquid internal static
pressure of the unit is included in
calculation of efficiency ratings. ISO
13256–1:1998 also does not specify any
liquid ESP requirements for testing. The
exclusion of pump power to overcome
ESP from system water loop piping in
ISO 13256–1:1998 ratings results in
higher efficiency ratings than would be
measured if ratings reflected pump
power to overcome ESP. ISO 13256–
1:1998 also does not specify a minimum
liquid ESP during testing for units with
integral pumps. For units without
integral pumps, the pump power
adjustment in ISO 13256–1:1998
estimates pump power at zero liquid
external static pressure.
As discussed previously, ISO 13256–
1:1998 was updated. However, the
pump power and liquid ESP provisions
in sections 5.1.4 and 5.1.6 of ISO
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13256–1:2021 are the same as those in
sections 4.1.4 and 4.1.6 of ISO 13256–
1:1998.
In the August 2022 NOPR, DOE
proposed to adopt provisions for
WSHPs in appendix C1 that align with
the recently adopted provisions for
water-source dedicated outdoor air
systems (‘‘DOASes’’). 87 FR 53302,
53328–53329. The proposed provisions
would require that all WSHPs with an
integral pump be tested with a liquid
ESP of 20 ft of water column, with a
¥0/+1 ft condition tolerance and a 1 ft
operating tolerance. Id. at 87 FR 53328.
For units without integral pumps, DOE
proposed to require that a ‘‘total
pumping effect’’ (calculated using the
same equation as in section 6.1.6.4 of
AHRI 920–2020) be added to the unit’s
measured power to account for the
pump power to overcome the internal
static pressure of the unit and a liquid
ESP of 20 ft of water column. Id. at 87
FR 53328–53329. Further, DOE
proposed to require that the measured
pump power or the pump effect
addition, as applicable, be included in
the condenser section power for units of
all capacities when performing cyclic
degradation during calculation of IEER.
Id. at 87 FR 53329. DOE requested
commented on the proposed provisions
to account for pump power to overcome
both internal pressure drop and a
representative level of liquid ESP for
WSHPs with and without integral
pumps. Id. DOE specifically requested
comment on the representativeness of
20 ft of water column as the liquid ESP
for WSHPs. Id.
In response to the August 20222
NOPR, ClimateMaster disagreed with
DOE’s proposed values for the liquid
ESP for WSHPs, arguing that the
pumping and cooling tower fan power
adder specified in AHRI 920–2020 is
incorrect. (ClimateMaster, No. 22 at p. 8)
ClimateMaster commented that,
according to a 2014 study conducted by
S. Kavanaugh and K. Rafferty, pumping
power for a closed loop ground-source
heat pump (‘‘GSHP’’) system can reach
3.75 W/kBtu/h but not exceed 10 W/
1kBtu/h, and that the values given in
AHRI 920 are much higher than these
values and are thus not representative of
an installed system. (Id. at pp. 8–9)
ClimateMaster recommended that DOE
use the approach in AHRI 600, which
includes pumping power for the
internal pressure drop and adds a
representative value for building pump
and cooling tower operation. (Id. at p. 9)
ClimateMaster commented that this
AHRI 600 power adder for building
pump and cooling tower energy
consumption is based on the results of
an analysis conducted of typical closed
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loop systems during the development of
the AHRI 600 standard, which resulted
in calculated power adders of 5.5 W/
kBtu/h for full-load conditions and 1 W/
kBtu/h for part-load conditions. (Id.)
FHP commented that the work done
by the AHRI 600 working group took a
more accurate approach to today’s
systems that allows for varying the fans
and pumping energy required during
part-load conditions. (FHP, No. 26 at p.
5) FHP recommended that DOE review
the values assigned to tower/pump
penalty in AHRI 600 for guidance on
this topic, stating that a single-head
pressure as a means of estimating the
pumping penalty does not allow for the
variations expected at part-load
conditions. (Id.) WaterFurnace
commented that adopting ISO 13256
and AHRI 600 would solve the issue,
noting that the pump power is
accounted for in AHRI 600.
(WaterFurnace, No. 20 at p.8)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. AHRI 600–2023 includes provisions
to separately account for pump power to
overcome liquid internal and external
static pressure.
Sections 6.3.3 and 6.4.3 of AHRI 600–
2023 specify to include pump power to
overcome the liquid internal static
pressure of the WSHP in all cooling and
heating ratings. The calculation for
pump power adjustment to account for
liquid internal static pressure uses a
similar methodology to ISO 13256–
1:1998, but uses a higher pump
efficiency of 75% (as compared to 30%
in ISO 13256–1:1998) to better represent
the efficiency of system pumps in
commercial water-loop installations.
Specifically, for units without integral
pumps, the AHRI 600–2023 approach
adds pump power to overcome liquid
internal static pressure. For units with
integral pumps, section 5.4.13 of AHRI
600–2023 specifies a liquid ESP value of
zero to use when testing WSHPs with an
integral pump for commercial ratings
and specifies to test at the minimum
liquid ESP if the minimum is higher
than zero ESP. In the case of testing a
unit with an integral pump at a liquid
ESP above zero, sections 6.3.3 and 6.4.3
of AHRI 600–2023 specify to subtract
pump power to overcome liquid ESP
using a similar methodology to the
approach for calculating pump power
adjustment for units without integral
pumps.
Sections 6.3.7 (for IEER), 6.3.11 (for
AEER), and 6.4.4 (for ACOP) of AHRI
600–2023 specify to include power to
account for power required for a system
pump to overcome liquid ESP
representative of a commercial water-
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loop installations. As discussed in
section III.E.3 of this final rule, AHRI
600–2023 specifies these provisions to
account for system pump power for
calculation of AEER, IEER, and ACOP,
but not for optional representations of
EER and COP.
The provisions for accounting for
pump power (to overcome liquid
internal and external static pressure)
were developed in AHRI 600 committee
meetings after publication of the August
2022 NOPR. While the AHRI 600–2023
approach is not the same as that
proposed in the August 2022 NOPR in
that it uses a different calculation
method and assumes a different liquid
ESP, it is consistent with the August
2022 NOPR proposal to include power
to represent power consumed by pumps
to overcome both liquid internal and
external static pressure. The AHRI 600–
2023 pump power adders are different
than those suggested by ClimateMaster.
However, having been developed
through an industry consensus process
subsequent to the timing of the August
2022 NOPR comment period, DOE
surmises that the pump power approach
specified in AHRI 600–2023 represents
the prevailing industry consensus
regarding the most appropriate method
for addressing pump power. Further,
DOE has concluded based on discussion
in AHRI 600 committee meetings that
the AHRI 600–2023 pump power
approach is representative of typical
water-loop WSHP applications. As a
result, in this final rule, DOE is
incorporating by reference into
appendix C1 the methods specified in
AHRI 600–2023 for accounting for
pump power.
DOE notes that section 5.4.13.2 of
AHRI 600–2023 specifies a minimum
liquid ESP of 7.0 psi for residential
representations. However, the
residential representations have not yet
been fully developed for WSHPs (see
section III.A.2 of this document for more
details). DOE will continue to work with
the AHRI 600 committee to develop
provisions for determining such ratings.
4. Test Liquid and Specific Heat
Capacity
The current DOE WSHP test
procedure, through adoption of section
4.1.9 of ISO 13256–1:1998, requires the
test liquid for water-loop heat pumps
and ground-water heat pumps to be
water, and the test liquid for groundloop heat pumps to be a 15 percent
solution by mass of sodium chloride in
water (i.e., brine). 10 CFR 431.96.
Further, the liquid enthalpy test method
in Annex C of ISO 13256–1:1998, which
is included in the current DOE WSHP
test procedure, requires the use of the
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specific heat capacity of the test liquid
for calculating cooling and heating
capacity but does not specify a value or
method for calculating the specific heat
capacity.
Section 5.1.7 of ISO 13256–1:2021
requires that the test liquid for the low
temperature heating test (i.e., EWT of
32 °F) must be a brine of the
manufacturer’s specification, while the
test liquid for all other tests may be
water or a brine of a composition and
concentration specified by the
manufacturer. ISO 13256–1:2021 does
not specify a value or method for
calculating the specific heat capacity of
any test liquids.
In the August 2022 NOPR, DOE
proposed in section 4.1 of proposed
appendix C1 that the test liquid for all
tests other than the proposed optional
‘‘HFL3’’ 10 low temperature heating test
(i.e., EWT of 32 °F) must be water,
unless the manufacturer specifies to use
a brine of 15-percent solution by mass
of sodium chloride in water. 87 FR
53302, 53329. DOE also proposed in
section 4.1 of proposed appendix C1
that the test liquid for the optional HFL3
low temperature heating test must be a
brine of 15-percent solution by mass of
sodium chloride in water. Id. Groundloop applications of WSHPs typically
use brine in the liquid loop because, in
cold weather, the liquid temperature
can reach 32 °F (i.e., the temperature at
which water freezes) in places. A 15percent solution by mass of sodium
chloride in water can withstand
temperatures as low as 14 °F before
freezing. Allowing the use of brine for
testing would provide manufacturers
the flexibility of providing ratings more
representative of ground-loop
applications. Therefore, DOE proposed
to require brine as the liquid for the
optional HFL3 low temperature heating
test (conducted with an EWT of 32 °F),
consistent with section 4.1.9 of ISO
13256–1:1998 and section 5.1.7 of ISO
13256–1:2021, to avoid the liquid
freezing during the test. Id.
In the August 2022 NOPR, DOE
tentatively concluded that a 15-percent
solution by mass of sodium chloride, as
specified in section 4.1.9.2 of ISO
13256–1:1998, is a representative brine
composition and concentration for
applications needing brine (e.g., groundloop), and that consumers can make
more representative comparisons
between models when all models are
rated with the same brine composition
and concentration. Id.
10 ‘‘HFL3’’ is the nomenclature used to define the
32 °F full-load heating test that DOE proposed to
add in appendix C1.
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As discussed in section III.D.2 of the
August 2022 NOPR, DOE proposed to
adopt specific sections of AHRI 340/
360–2022 in its test procedure for
WSHPs. Id. AHRI 340/360–2022 in turn
references the test method in ANSI/
ASHRAE 37–2009, in which section
12.2.1 requires that thermodynamic
properties of liquids be obtained from
the ASHRAE Handbook—
Fundamentals.11 The ASHRAE
Handbook—Fundamentals specifies
specific heat capacity values for water
and for a brine of 15 percent solution by
mass of sodium chloride at multiple
temperatures. The absence of provisions
in ISO 13256–1:1998 for how to
determine specific heat capacity for test
liquids creates the potential for
variation in measured values based on
how specific heat capacity is
determined. Therefore, to minimize any
such variation, DOE instead proposed in
the August 2022 NOPR to adopt relevant
provisions of ANSI/ASHRAE 37–2009.
Id. DOE tentatively determined that the
specifications in ANSI/ASHRAE 37–
2009 would be appropriate for testing
WSHPs because they are the generally
accepted industry method used for
testing similar equipment, such as
WCUACs. Id.
In the August 2022 NOPR, DOE
requested comment on the proposed
requirements for using water or a brine
of 15-percent solution by mass of
sodium chloride as the test liquid. Id.
DOE also requested comment on the
representativeness and test burden
associated with permitting the use of
different liquids for different tests. Id.
Finally, DOE requested comments on
the proposal to utilize the
thermodynamic properties specified in
ANSI/ASHRAE 37–2009 through DOE’s
proposed incorporation by reference of
AHRI 340/360–2022. Id.
In response to the August 2022 NOPR,
MIAQ commented that sodium chloride
is not a common anti-freeze and that
propylene and ethylene glycol are more
common. (MIAQ No. 23 at p. 6) MIAQ
commented that it is unsure if
nationally recognized testing
laboratories 12 are equipped to deal with
15-percent solution by mass of sodium
chloride as the test liquid. (Id.) MIAQ
stated that specifying a particular
antifreeze rather than relevant thermal
properties for the test fluid hinders
innovation and generates a heavy
burden to develop and test with the
11 The ASHRAE Handbook—Fundamentals is
available at: https://www.ashrae.org/technicalresources/ashrae-handbook.
12 MIAQ used the abbreviation NRL, but DOE
expects that the intended term was NRTL, the
acronym for nationally recognized testing
laboratory.
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specified medium. (Id.) MIAQ argued
that specifying sodium chloride as the
test liquid may require redesign of the
units to avoid corrosion. (Id.)
WaterFurnace commented that
supporting ISO 13256 and AHRI 600
would solve the issue. (WaterFurnace
No. 20 at p. 8) WaterFurnace stated that
it prefers to use methanol or ethanol as
the test liquid because sodium chloride
can damage lab equipment. (Id.)
ClimateMaster supported DOE’s
proposal to make provisions for low
temperature testing but disagreed with
the proposed fluid for testing.
(ClimateMaster, No. 22 at p. 9)
ClimateMaster stated that sodium
chloride is not representative of a brine
solution used in water-source
applications in the field and is a
carryover from a test liquid used in
older standards such as AHRI 330–98,
which was corrosive to test lab facilities
and caused premature wear of hydronic
components. (Id.) ClimateMaster
recommended that DOE work with
industry to create a national deviation of
13256–1:1998 that includes provisions
for the use of a 15-percent solution by
mass of methanol in water involving a
specific gravity of methanol at 0.976
with a solution temperature of 68 °F.
(Id.) ClimateMaster stated that this fluid
is commonly used in the industry and
has been an available option in the
AHRI 13256–1:1998 certification
program since its inception, and if DOE
does not select this solution, an
alternative option would be a 20-percent
solution of propylene glycol, which is
also commonly used in the industry.
(Id.)
ClimateMaster supported DOE’s
proposal to require a standard set of
properties for consistent performance
calculations but disagreed that the only
reference allowed for sink or source
liquids can be the 2001 ASHRAE
Handbook, stating that it does not
include properties for alternative testing
fluids, such as methanol in water, and
therefore limits the available options for
testable brine solutions. (Id.)
ClimateMaster recommended that DOE
provide provisions under a national
deviation of ISO 13256–1:1998 while
allowing for the use of other established
property databases in addition to the
2001 ASHRAE handbook, such as the
published data from Melinder 2010.13
(Id.) WaterFurnace agreed with the need
for a specified source of properties and
commented that supporting ISO 13256
13 Properties of Secondary Working Fluids for
Indirect Systems, Melinder, 2010 (‘‘Melinder
2010’’).
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and AHRI 600 would solve the issue.
(WaterFurnace, No. 20 at p. 8)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 in appendix
C1. Section 5.4.14 of AHRI 600–2023
specifies that all cooling and heating
tests be conducted with a 15 percent
solution by mass of methanol in water,
with a tolerance of 2 percentage points
on the solution concentration and
requires that the concentration be
verified prior to and after completion of
all standard rating tests. Section 5.4.14
of AHRI 600–2023 also specifies to use
Melinder 2010 as the source for all
thermodynamic properties of the test
liquid. Finally, sections 6.3.3.2 and
6.4.3.2 of AHRI 600–2023 include
provisions to remove any influence of
the methanol solution on efficiency
ratings, so that values are similar to
those that would result from testing
using pure water, which is the most
common liquid used in non-geothermal
installations of WSHPs. Specifically,
these provisions specify to multiply all
measured capacity values by 1.01 and to
multiply all measured cooling total
power values by 0.99.
DOE has concluded that the
provisions in AHRI 600–2023 regarding
test liquid and specific heat capacity
provide a representative and repeatable
method for testing WSHPs. Comments
received in response to the August 2022
NOPR and discussion in AHRI 600
committee meetings indicate that a
methanol solution is a more
representative test liquid than sodium
chloride brine and is more practical for
testing as it is not corrosive to laboratory
equipment. Further, the AHRI 600–2023
requirement to use methanol solution
for all tests ensures repeatable results
and minimizes test burden by avoiding
a need to change test liquid between
tests. By specifying use of Melinder
2010 as the source for thermodynamic
properties, AHRI 600–2023 also ensures
that thermodynamic properties for the
test fluid are applied consistently.
Additionally, the provisions in sections
6.3.3.2 and 6.4.3.2 of AHRI 600–2023
adjust measured values to be more
representative of WSHP operation in
non-geothermal applications (which do
not encounter freezing temperatures),
without the need to change test liquids
to use water for higher temperature tests
and methanol for low-temperature
heating tests. DOE also considers the
inclusions of these provisions in AHRI
600–2023 to represent industry
consensus on the most appropriate
method for testing WSHPs. Therefore,
for the reasons discussed, DOE is
incorporating by reference into
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appendix C1 the test liquid provisions
from AHRI 600–2023 in this final rule.
5. Liquid Flow Rate
The current DOE test procedure,
through adoption of section 4.1.6.2 of
ISO 13256–1:1998, requires units with
an integral liquid pump to be tested at
the liquid flow rates specified by the
manufacturer or those obtained at zero
ESP difference, whichever provides the
lower liquid flow rate. 10 CFR 431.96.
Section 4.1.6.3 of ISO 13256–1:1998
requires that units without an integral
liquid pump be tested at a liquid flow
rate specified by the manufacturer.
In contrast to ISO 13256–1:1998, DOE
noted in the June 2018 RFI that AHRI
340/360–2022 does not use a
manufacturer-specified liquid flow rate,
and instead specifies inlet and outlet
water temperatures for WCUACs to be
85 °F and 95 °F, respectively, for
standard-rating full-capacity operation.
The temperature difference between
inlet and outlet determines the liquid
flow rate for the test. 83 FR 29048,
29054.
In the August 2022 NOPR, DOE
proposed to incorporate by reference
specific sections of AHRI 340/360–2022
in its test procedure for WSHPs,
including Table 6. 87 FR 53302, 53330.
Table 6 of AHRI 340/360–2022 specifies
inlet and outlet liquid temperatures of
85 °F and 95 °F, respectively, for
standard-rating cooling full-capacity
operation. Id. This requires that liquid
flow rate for the full-load cooling test is
set at a level that results in a 10 °F
temperature rise from the 85 °F inlet to
the 95 °F outlet temperature. Id. Also,
DOE proposed to adopt table 9 of AHRI
340/360–2022, which specifies use of
manufacturer-specified part-load water
flow rates for part-load tests. Id. at 87 FR
53331. In addition, DOE proposed that
section E7 of AHRI 340/360 2022, which
addresses units with condenser head
pressure control stating that part-load
liquid flow rate shall not exceed the
liquid flow rate used for the full-load
tests, be adopted in sections 5.1.1 and
5.1.2.1.2 of proposed appendix C1. Id.
For heating tests, DOE proposed to
specify in section 6.1 of proposed
appendix C1 that if IEER is determined
using option 1 in section 5.1 of
proposed appendix C1, the liquid flow
rate determined from the ‘‘Standard
Rating Conditions Cooling’’ test for
water-cooled equipment, as defined in
Table 6 of AHRI 340/360–2022, must be
used for all heating tests. Id. If IEER is
determined using option 2 in section 5.1
of proposed appendix C1, DOE
proposed in section 5.1.2.1.1 of
proposed appendix C1 to use the liquid
flow rate determined from the CFL3
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high temperature cooling test for all
heating tests. Id. Lastly, relating to
tolerances, DOE proposed to require a
condition tolerance of 1 percent for
liquid flow rate, consistent with the
condition tolerance specified in Table 9
of ISO 13256–1:1998 and adopt Table 11
of AHRI 340/360–2022, which specifies
an operating tolerance of 2 percent for
liquid flow rate. Id.
DOE requested commented on its
proposal to adopt the AHRI 340/360–
2022 approach for setting liquid flow
rate for the full-load cooling test,
namely by specifying inlet and outlet
liquid temperature conditions rather
than using a manufacturer-specified
flow rate. Id. Additionally, DOE
requested feedback on its proposals to
use manufacturer-specified part-load
liquid flow rates for part-load tests, that
the part-load flow rate be no higher than
the full-load flow rate, and to use the
full-load liquid flow rate if no part-load
liquid flow rate is specified. Id. In
relation to heating tests, DOE requested
comment on its proposal to use the
liquid flow rate determined from the
full-load cooling test for all heating
tests. Id. Lastly, DOE requested
comment on its proposal to specify an
operating tolerance of 2 percent and a
condition tolerance of 1 percent for
liquid flow rate in all tests with a target
liquid flow rate. Id. at 87 FR 53331–
53332.
In response to the August 2022 NOPR,
ClimateMaster and WaterFurnace stated
that they disagree with the proposal to
adopt the AHRI 340/360 approach for
setting liquid flow rate because it moves
the test standard along a prescriptive
path that would discourage innovation
for improvements in pressure drop and
flow rate in heat exchanger design.
(ClimateMaster, No. 22 at pp. 9–10;
WaterFurnace, No. 20 at pp. 8–9)
ClimateMaster recommended that DOE
allow manufacturers to specify a given
flow rate for full-load cooling tests.
(ClimateMaster, No. 22 at p. 10)
ClimateMaster also commented that
DOE should also specify a maximum
limit of 3.5 GPM/ton, which
ClimateMaster stated aligns with DOE’s
statements in the August 2022 NOPR
that 3 GPM/ton is a typical water flow
rate for WSHPs that results in a
temperature rise of approximately a
10 °F. (Id. at pp. 9–10) ClimateMaster
commented that while flowrate is
typically used and specified when
testing WSHP equipment, this is not the
case for temperature rise. (Id. p. 10)
MIAQ recommended that DOE continue
to support ISO 13256–1. (MIAQ, No. 23
at p. 7)
Regarding the part-load liquid flow
rates, ClimateMaster supported DOE’s
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proposal to use manufacturer-specified
part-load liquid flow rates for part-load
tests. (ClimateMaster, No. 22 at p. 10)
ClimateMaster recommended that the
full-load liquid flow rate should be used
for part-load tests if the system does not
automatically reduce the liquid flow
rate in part-load operation to the partload flow rate when installed. (Id.)
WaterFurnace agreed with DOE’s
proposal to use manufacturer-specified
part-load liquid flow rates for part-load
tests and commented that supporting
ISO 13256/AHRI 600 would solve the
issue. (WaterFurnace, No. 20 at p. 9)
Regarding liquid flow rate for heating
tests, ClimateMaster supported DOE’s
proposal to use the full-load cooling
liquid flow rate for all full-load heating
tests. (ClimateMaster, No. 22 at p. 10)
MIAQ commented that using the liquid
flow rate determined from the full-load
cooling test for all heating tests could be
a problem in conditions where the
saturated suction temperature is too
high, overloading the compressor.
(MIAQ, No. 23 at p. 7) MIAQ stated that
this may not be an issue with a low
enough EWT. (Id.) MIAQ commented
that systems with inverter-driven
compressors and active head pressure
control may present challenges to
fulfilling these tests. (Id.) WaterFurnace
commented that supporting ISO 13256
and AHRI 600 would solve the issue.
(WaterFurnace, No. 20 at p. 9)
WaterFurnace commented that most
standards have abandoned the
prescriptive approach of determining
liquid flow rate from the full-load
cooling test to allow innovation and
efficiency improvement. (Id.)
WaterFurnace stated that using
manufacturer-specified flow rate is
preferred. (Id.)
Regarding tolerances liquid flow rates,
ClimateMaster, WaterFurnace, and
MIAQ commented in support of DOE’s
proposal to specify an operating
tolerance of 2 percent and a condition
tolerance of 1 percent for liquid flow
rate in all tests with a target liquid flow
rate. (ClimateMaster, No. 22 at p. 10;
WaterFurnace, No. 20 at p. 9; MIAQ, No.
23 at p. 7)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. Section 5.4.15 of AHRI 600–2023
includes provisions regarding liquid
flow rate. Specifically, this section
specifies use of a manufacturerspecified flow rate rather than a fixed
temperature rise (as recommended by
commenters), but, similar to
ClimateMaster’s recommendation,
section 5.4.15 also provides a maximum
flow rate of 0.275 GPM per kBtu/h
(which is equivalent to 3.3 GPM/ton,
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slightly lower than the 3.5 GPM/ton
limit recommended in ClimateMaster’s
comment). Section 5.4.14 also specifies
that a single manufacturer-specified
flow rate be used for all tests, unless the
equipment automatic adjusts flow rate
or the liquid flow rate is reduced for
operation at low EWTs for head
pressure control, per section 5.9 of
AHRI 600–2023. Further, section 5.4.15
specifies that if there is not a specified
liquid flow rate and that the system
does not provide automatic adjustment
of the liquid flow that a liquid flow rate
of 0.25 GPM per kBtu/h is used for all
tests. It also specifies a liquid flow rate
condition tolerance of 1 percent.
DOE has concluded that the approach
for liquid flow rate specified in AHRI
600–2023 provides a representative and
appropriate approach for testing
WSHPs. The use of manufacturerspecified flow rate provides flexibility
to manufacturers while the maximum
liquid flow rate limit prevents
manufacturer specification of
unrepresentatively high flow rates for
testing. With regards to MIAQ’s concern
that using the liquid flow rate
determined from the full-load cooling
test for all heating tests could be a
problem in conditions where the
saturated suction temperature is too
high, overloading the compressor, DOE
notes that the provisions specified in
AHRI 600–2023 and incorporated by
reference in this final rule allow
manufacturers to specify different flow
rates for tests other than the full-load
cooling test so long as the specified flow
rates for other tests are (a) below the
maximum flow rate of 0.275 GPM per
kBtu/h; and (b) achieved via automatic
adjustment of the liquid flow rate by the
equipment under test. Therefore, a
manufacturer would have the ability to
set different liquid flow rates for tests
other than full-load cooling tests to
ensure operation representative of how
the equipment would operate under
such conditions in field installations.
DOE also considers the inclusions of
these provisions in AHRI 600–2023 to
represent industry consensus on the
most appropriate method for testing
WSHPs. Therefore, for the reasons
discussed, DOE is incorporating by
reference into appendix C1 the liquid
flow rate provisions from AHRI 600–
2023 in this final rule.
6. Refrigerant Line Losses
Split-system WSHPs have refrigerant
lines that can transfer heat to and from
their surroundings, which can
incrementally affect measured capacity.
To account for this transfer of heat
(referred to as ‘‘line losses’’), the current
DOE WSHP test procedure, through
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adoption of ISO 13256–1:1998, provides
that if line loss corrections are to be
made, they shall be included in the
capacity calculations (in section B4.2 for
the indoor air enthalpy method and in
section C3.3 for the liquid enthalpy test
method of ISO 13256–1:1998). 10 CFR
431.96. ISO 13256–1:1998 does not
specify the circumstances that require
line loss corrections nor the method to
use to determine an appropriate
correction.
Section 7.3.3.4 of ANSI/ASHRAE 37–
2009, the method of test referenced in
AHRI 340/360–2022, specifies more
detailed provisions to account for line
losses of split systems in the outdoor air
enthalpy method, and section 7.6.7.1 of
ANSI/ASHRAE 37–2009 specifies to use
the same provisions for the outdoor
liquid coil method.
In the August 2022 NOPR, DOE
proposed to incorporate by reference
specific sections of AHRI 340/360–2022.
87 FR 53302, 53332. AHRI 340/360–
2022 in turn references sections 7.6.7.1
and 7.3.3.4 of ANSI/ASHRAE 37–2009.
Id. Sections 7.6.7.1 and 7.3.3.4 of ANSI/
ASHRAE 37–2009 specify calculations
for determining the line losses for bare
copper or insulated lines. Id. DOE
requested comment on the proposal to
adopt the provisions for line loss
adjustments included in sections 7.6.7.1
and 7.3.3.4 of ANSI/ASHRAE 37–2009
through incorporation by reference of
AHRI 340/360–2022. Id.
In response to the August 2022 NOPR,
ClimateMaster commented that
adopting the line loss adjustments in
ASHRAE 37–2009 is acceptable, as it is
an industry best practice, but
ClimateMaster stated it does not
produce any split system heat pumps
for use in commercial applications.
(ClimateMaster, No. 22 at p.10)
ClimateMaster recommended that DOE
work with industry to create a national
deviation of ISO 13256–1:1998 that
adopts the provisions of ANSI/ASHRAE
37–2009. (Id.) WaterFurnace agreed
with DOE’s proposal. (WaterFurnace,
No. 20 at p. 9)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. This includes section 5.1 of AHRI
600–2023. This section in turn
references sections 7.6.7.1 and 7.3.3.4 of
ANSI/ASHRAE 37–2009, which is
consistent with the proposal from the
August 2022 NOPR. DOE considers the
inclusion of these provisions in the
AHRI 600–2023 to represent industry
consensus that these provisions provide
an appropriate method for testing
WSHPs. As a result, DOE is
incorporating by reference into
appendix C1 the methods from AHRI
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adjustments in this final rule.
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7. Airflow Measurement
The current DOE WSHP test
procedure, through adoption of section
D.1 of ISO 13256–1:1998, requires
airflow measurements to be made in
accordance with the provisions
specified in several different industry
test standards, ‘‘as appropriate.’’ 14 10
CFR 431.96. However, ISO 13256–
1:1998 is not explicit regarding the
circumstances under which the different
airflow measurement approaches
included in these industry test
standards should be used.
Section F8 of ISO 13256–1:1998
specifies the requirements for the nozzle
apparatus used to measure airflow. This
device determines airflow by measuring
the change in pressure across a nozzle
of known geometry. Airflow derivations
using this approach often include a
discharge coefficient (i.e., the ratio of
actual discharge air to theoretical
discharge air) to account for factors that
reduce the actual discharge air, such as
nozzle resistance and airflow
turbulence. In general, as the nozzle
throat diameter decreases, nozzle
resistance increases, thereby reducing
actual discharge which is characterized
by a lower discharge coefficient.
Turbulent airflow (as characterized by
Reynolds numbers 15) and temperature
also impact the discharge coefficient.
Section F8.9 of ISO 13256–1:1998
specifies that it is preferable to calibrate
the nozzles in the nozzle apparatus, but
that nozzles of a specific geometry may
be used without calibration and by
using the appropriate discharge
coefficient specified in a lookup table in
section F8.9 of ISO 13256–1:1998. ISO
13256–1:1998 does not specify the
method that should be applied,
however, to determine the coefficient of
discharge for conditions that do not
exactly match the values provided in
the look-up table.
Elsewhere, sections 6.2 and 6.3 of
ANSI/ASHRAE 37–2009 includes
14 The cited industry test standards include: ISO
3966:1977, ‘‘Measurement of fluid flow in closed
conduits—Velocity area method using Pitot static
tubes;’’ ISO 5167–1:1991, ‘‘Measurement of fluid
flow by means of pressure differential devices—Part
1: Orifice plates, nozzles and Venturi tubes inserted
in circular cross-section conduits running full;’’ and
ISO 5221:1984, ‘‘Air Distribution and air
diffusion—Rules to methods of measuring airflow
rate in an air handling duct.’’ These standards can
be purchased from the ISO store at https://
www.iso.org/store.html.
15 ‘‘Reynolds number’’ is a dimensionless number
that characterizes the flow properties of a fluid.
Section F8.9 of ISO 13256–1:1998 includes an
equation for calculating Reynolds number that
depends on a temperature factor, air velocity, and
throat diameter.
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provisions regarding the nozzle airflow
measuring apparatus that are identical
to the provisions in section F8 of ISO
13256–1:1998, except for the method
used to determine the coefficient of
discharge. Section 6.3.3 of ANSI/
ASHRAE 37–2009 uses a calculation in
place of the look-up table used in ISO
13256–1:1998, thereby allowing
determination of the coefficient of
discharge at any point within the
specified range.
In the August 2022 NOPR, DOE
proposed to incorporate by reference
specific sections of AHRI 340/360–2022.
87 FR 53302, 53333. AHRI 340/360–
2022 in turn references the test method
in ANSI/ASHRAE 37–2009. Id. Sections
6.2 and 6.3 of ANSI/ASHRAE 37–2009
include provisions regarding the nozzle
airflow measuring apparatus that are
identical to the provisions in section F8
of ISO 13256–1:1998, except for the
method used to determine the
coefficient of discharge. Id. Section 6.3.3
of ANSI/ASHRAE 37–2009 uses a
calculation to determine the coefficient
of discharge, thereby allowing
determination of the coefficient of
discharge at any point within the
specified range. Id. DOE requested
comment on the proposal to adopt the
calculation of discharge coefficients and
air measurement apparatus
requirements as specified in ANSI/
ASHRAE 37–2009. Id.
In response to the August 2022 NOPR,
ClimateMaster supported DOE’s
proposal to adopt the calculation of
discharge coefficients and air
measurement apparatus requirements of
ANSI/ASHRAE 37–2009, as it is an
industry best practice, and
recommended that DOE work with
industry to create a national deviation of
ISO 13256–1:1998 that includes the
provisions of ANSI/ASHRAE 37–2009.
(ClimateMaster No. 22 at p. 10)
WaterFurnace agreed with DOE’s
proposal. (WaterFurnace, No. 20 at p. 9)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. This includes section 5.1 of AHRI
600–2023. This section in turn
references the test method in ANSI/
ASHRAE 37–2009, which is consistent
with the proposal from the August 2022
NOPR. DOE considers the inclusion of
these provisions in AHRI 600–2023 to
represent industry consensus that these
provisions provide an appropriate
method for testing WSHPs. As a result,
DOE is incorporating by reference into
appendix C1 the methods from AHRI
600–2023 for measuring airflow in this
final rule.
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8. Air Condition Measurement
Indoor air temperature and humidity
are key parameters that affect WSHP
performance, and for this reason, ISO
13256–1:1998 requires accurate indoor
air condition measurements. However,
informative annexes E and F of ISO
13256–1:1998 specify few requirements
for the methods used to measure indoor
air temperature and humidity.
In the August 2022 NOPR, DOE
proposed to incorporate by reference
appendix C of AHRI 340/360–2022. 87
FR 53302, 53333. Appendix C of AHRI
340/360–2022 provides detailed
specifications for the measurement of
air conditions (including indoor air),
including aspirating psychrometer
requirements in section C3.2.1 of AHRI
340/360–2022 and sampling
requirements in section C3.3 of AHRI
340/360–2022. Id. DOE requested
commented on the proposal to adopt the
air condition measurement provisions
in appendix C of AHRI 340/360–2022.
Id.
In response to the August 2022 NOPR,
ClimateMaster supported DOE’s
proposal to adopt the air condition
measurement provisions in appendix C
of AHRI 340/360–2022, as it is industry
best practice, and recommended that
DOE work with industry to create a
national deviation of ISO 13256–1:1998
that includes similar air condition
measurement provisions.
(ClimateMaster No. 22 at p. 11)
WaterFurnace agreed with DOE’s
proposal. (WaterFurnace No. 20 at p. 9)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. This includes appendix C of AHRI
600–2023. This language is consistent
with appendix C of AHRI 340/360–
2022, as proposed in the August 2022
NOPR, and addresses comments that
DOE should adopt AHRI 600. DOE
considers the air condition
measurement approach specified in
AHRI 600–2023 to represent industry
consensus regarding the most
appropriate method for measuring air
conditions for WSHPs. As a result, DOE
is incorporating by reference into
appendix C1 the methods from AHRI
600–2023 for measuring air conditions
in this final rule.
9. Duct Losses
In the calculations for cooling and
heating capacities for the indoor air
enthalpy test method of ISO 13256–
1:1998, the test standard includes a
footnote in sections B3 and B4 of annex
B stating that the equations do not
provide allowances for heat leakage in
the test equipment (i.e., duct losses). In
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contrast, section 7.3.3.3 of ANSI/
ASHRAE 37–2009 requires adjustments
for such heat leakages and specifies
methods to calculate appropriate values
for the adjustments.
In the August 2022 NOPR, DOE
proposed to incorporate by reference
specific sections of AHRI 340/360–2022.
87 FR 53302, 53334. AHRI 340/360–
2022 in turn references section 7.3.3.3 of
ASHRAE 37–2009, which requires and
provides equations for duct loss
adjustments. Id. DOE requested
comment on whether the duct loss
adjustments as described in section
7.3.3.3 of ANSI/ASHRAE 37–2009 or
any other duct loss adjustments are used
to adjust capacity measured using the
indoor air enthalpy method when
testing WSHPs. Id.
In response to the August 2022 NOPR,
ClimateMaster supported DOE’s
proposal to adopt the duct loss
provisions as it is an industry best
practice for companies that produce
split-system heat pumps for use in
commercial applications.
(ClimateMaster, No. 22 at p. 11)
ClimateMaster recommended that DOE
work with industry to create a national
deviation of ISO 13256–1:1998 that
includes these provisions of ANSI/
ASHRAE 37–2009. (Id.) WaterFurnace
agreed with DOE’s proposal.
(WaterFurnace, No. 20 at pp. 9)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. This includes section 5.1 of AHRI
600–2023. This section in turn
references ANSI/ASHRAE 37–2009,
including section 7.3.3.3, which is
consistent with the proposal from the
August 2022 NOPR. DOE considers the
inclusion of these provisions in AHRI
600–2023 to represent industry
consensus that these provisions provide
an appropriate method for testing
WSHPs. Therefore, DOE is incorporating
by reference into appendix C1 the
equations for duct loss adjustments from
section 5.1 of AHRI 600–2023 in this
final rule. Regarding the comment from
ClimateMaster, DOE notes that these
provisions for calculating duct losses
apply to testing all WSHPs, not just split
systems.
10. Refrigerant Charging
The amount of refrigerant can have a
significant impact on the system
performance of air conditioners and
heat pumps. DOE’s current test
procedure for WSHPs requires that units
be set up for test in accordance with the
manufacturer installation and operation
manuals. 10 CFR 431.96(e). In addition,
the current DOE test procedure states
that if the manufacturer specifies a
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range of superheat, sub-cooling, and/or
refrigerant pressures in the installation
and operation manual, any value within
that range may be used to determine
refrigerant charge or mass of refrigerant,
unless the manufacturer clearly
specifies a rating value in its installation
or operation manual, in which case the
specified rating value shall be used. 10
CFR 431.96(e)(1) However, the current
DOE test procedure for WSHPs does not
provide charging instructions to be used
if the manufacturer does not provide
instructions in the manual that is
shipped with the unit or if the provided
instructions are unclear or incomplete.
In addition, ISO 13256–1:1998 does not
provide any specific guidance on setting
and verifying the refrigerant charge of a
unit aside from stating in section A2.3
of that standard that equipment shall be
evacuated and charged with the type
and amount of refrigerant specified in
the manufacturer’s instructions, where
necessary.
In the August 2022 NOPR, DOE
proposed to incorporate by reference
section 5.8 of AHRI 340/360–2022. 87
FR 53302, 53334. This section specifies
refrigerant charging parameters,
including specifying which set of
installation instructions to use for
charging, explaining what to do if no
instructions are provided, specifying
that target values of parameters are the
centers of the ranges allowed by
installation instructions, and specifying
tolerances for the measured values. Id.
The approach also requires that
refrigerant line pressure gauges be
installed for single-package units, unless
otherwise specified in manufacturer
instructions. Id. DOE requested
comment on the proposal to adopt the
refrigerant charging requirements in
section 5.8 of AHRI 340/360–2022. Id. at
87 FR 53335.
In response to the August 2022 NOPR,
ClimateMaster commented that while
all commercially single package WSHP
units are developed with specific
factory system charge weights, the only
provision DOE proposed for a charge
weight tolerance is in Table 4 of section
5.8.3 of AHRI 340/360–2022, which
specifies a tolerance of ±2 oz.
(ClimateMaster, No. 22 at p. 11)
ClimateMaster commented that it
considers this tolerance unacceptable,
as 2 oz can be upwards of 10 percent of
the overall system charge on small
capacity heat pumps. (Id.)
ClimateMaster further stated that the
procedures for charging that DOE
provided in sections 5.8.4.1 and 5.8.4.2
of AHRI 340/360–2022 are not
applicable as most single package
systems do not contain a liquid line
service connection. (Id.) ClimateMaster
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commented that the tolerances that DOE
provided in Table 4 of section 5.8.3 of
AHRI 340/360–2022 reference items
related to outdoor air conditions, which
are not applicable to WSHPs. (Id.)
ClimateMaster commented that DOE’s
proposal lacks provisions for the
possibility that the operating mode of
the system could set the charge. (Id.) For
these reasons, ClimateMaster
recommended that DOE work with
industry to create a national deviation of
ISO 13256–1:1998 that allows the
WSHP industry to develop a list of
charging provisions that meet the intent
of those found in AHRI 340/360–2022.
(Id.) WaterFurnace agreed with DOE’s
proposal regarding refrigerant charging.
(WaterFurnace, No. 20 at p. 9)
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. This includes section 5.4.11 of AHRI
600–2023. This language is consistent
with section 5.8 of AHRI 340/360–2022,
as proposed for use in the August 2022
NOPR, and addresses commenters’
concerns that DOE should adopt AHRI
600. With regards to the comment from
ClimateMaster regarding the refrigerant
charging proposals in the August 2022
NOPR (which are consistent with the
provisions in AHRI 600–2023), DOE
notes that these provisions are used
only if the manufacturer’s charging
instructions do not specify a tighter
charging tolerance (as specified in
section 5.4.11.4 of AHRI 600–2023).
Therefore, these provisions provide
flexibility to manufacturers to specify
charging instructions appropriate to
their models and serve mainly to
address cases in which manufacturer’s
instructions provide inadequate,
incomplete, or conflicting charging
instructions. Specifically, these
provisions allow manufacturers to
specify tighter tolerances and/or to
specify charging based on whatever
method is most appropriate for a given
model.
DOE considers the inclusion of these
provisions in AHRI 600–2023 to
represent industry consensus that these
provisions provide an appropriate
method for testing WSHPs. Therefore,
DOE is incorporating by reference into
appendix C1 the refrigerant charging
requirements from section 5.4.11 of
AHRI 600–2023 in this final rule.
11. Voltage
Operating voltage can affect the
measured efficiency of air conditioners
and heat pumps. The current DOE
WSHP test procedure, through adoption
of Tables 1 and 2 of ISO 13256–1:1998,
requires units rated with dual
nameplate voltages to be tested at both
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voltages or at the lower voltage if only
a single rating is to be published. 10
CFR 431.96.
In the August 2022 NOPR, DOE
proposed to incorporate by reference
section 6.1.3.1 of AHRI 340/360–2022.
87 FR 53302, 53335. Section 6.1.3.1 of
AHRI 340/360–2022 specifies that units
with dual nameplate voltage ratings
must be tested at the lower of the two
voltages if only a single standard rating
is to be published, or at both voltages if
two standard ratings are to be
published. Id. This approach is
equivalent to the approach for dual
nameplate voltages specified in tables 1
and 2 of ISO 13256–1:1998 and tables 2
and 3 of ISO 13256–1:2021. Id. DOE
requested commented on the proposal
to adopt the voltage provisions in
section 6.1.3.1 of AHRI 340/360–2022.
Id.
In response to the August 2022 NOPR,
ClimateMaster supported DOE’s
proposal to adopt the voltage provisions
in section 6.1.3.1 of AHRI 340/360–2022
because it is industry best practice and
recommended that DOE work with
industry to create a national deviation of
ISO 13256–1:1998 that includes the
proposed language. (ClimateMaster, No.
22 at pp. 11–12) WaterFurnace agreed
with DOE’s proposal. (WaterFurnace,
No. 20 at p. 9).
As discussed in section III.D of this
final rule, DOE is incorporating by
reference AHRI 600–2023 into appendix
C1. This includes section 6.2.2 of AHRI
600–2023. This language is consistent
with section 6.1.3.1 of AHRI 340/360–
2022, which was proposed in the
August 2022 NOPR, as well as with
tables 1 and 2 of ISO 13256–1:1998 and
tables 2 and 3 of ISO 13256–1:2021.
DOE considers the inclusion of these
voltage provisions in AHRI 600–2023 to
represent industry consensus that these
provisions provide an appropriate
method for testing WSHPs. As a result,
DOE is incorporating by reference into
appendix C1 the voltage provisions from
AHRI 600–2023 in this final rule.
12. Non-Standard Low-Static Indoor Fan
Motors
As discussed in section III.F.1.a of
this document, DOE is adopting higher
ESPs for WSHPs with a cooling capacity
greater than or equal to 75,000 Btu/h
that are included in section 5.5.1.1 of
AHRI 600–2023 and are consistent with
the ESP levels recommended in the
ACUAC and ACUHP Working Group TP
Term Sheet. However, individual
models of WSHPs in this capacity range
with indoor fan motors intended for
installation in applications with a low
ESP may not be able to operate at the
proposed full-load ESP requirements at
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the full-load indoor rated airflow. To
address this situation, section 3.2.30 of
AHRI 600–2023 defines ‘‘non-standard
low-static indoor fan motors’’ as motors
in units with cooling capacity greater
than or equal to 75,000 Btu/h which
cannot maintain ESP as high as
specified in the test procedure when
operating at the full-load rated indoor
airflow and that are distributed in
commerce as part of an individual
model within the same basic model that
is distributed in commerce with a
different motor specified for testing that
can maintain the required ESP. Section
5.7.4.3 of AHRI 600–2023 includes test
provisions for WSHPs with nonstandard low-static indoor fan motors
that cannot reach the ESP within
tolerance during testing, which require
using the maximum available fan speed
that does not overload the motor or
motor drive, adjusting the airflowmeasuring apparatus to maintain airflow
within tolerance, and operating with an
ESP as close as possible to the minimum
ESP requirements for testing. This
approach is consistent with the industry
test standard referenced by the DOE test
procedure for DX–DOASes (AHRI 920–
2020, section 6.5.2.5). See appendix B to
10 CFR 431.96.
As discussed in section III.G.3 of this
document, DOE is clarifying that
representations for a WSHP basic model
must be based on the least efficient
individual model(s) distributed in
commerce within the basic model (with
the exception specified in 10 CFR
429.43(a)(3)(v)(A) for certain individual
models with the components listed in
Table 6 to 10 CFR 429.43(a)(3)). DOE
has concluded that the combination of
(1) the provisions in AHRI 600–2023 for
testing models with ‘‘non-standard lowstatic indoor fan motors’’ with (2) the
requirement that basic models be rated
based on the least efficient individual
model (with certain exceptions, as
discussed) provides an appropriate
approach for handling WSHP models
with these motors because if an
individual model with a non-standard
low-static indoor fan motor is tested, the
test would be conducted at an indoor
airflow representative for that model.
But because testing at the rated airflow
for such an individual model would
result in testing at an ESP lower than the
requirement and thus a lower indoor fan
power, the representations for that basic
model will be required to be based on
an individual model with an indoor fan
motor that can achieve the ESP
requirements at the rated airflow.
Consistent with incorporating by
reference AHRI 600–2023 into appendix
C1, in this final rule, DOE is adopting
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the AHRI 600–2023 provisions for
testing models with non-standard lowstatic indoor fan motors.
G. Configuration of Unit Under Test
1. Background and Summary
WSHPs are sold with a wide variety
of components, including many that can
optionally be installed on or within the
unit both in the factory and in the field.
In all cases, these components are
distributed in commerce with the WSHP
but can be packaged or shipped in
different ways from the point of
manufacturer for ease of transportation.
Each optional component may or may
not affect a model’s measured efficiency
when tested to the DOE test procedure
adopted in this final rule. For certain
components not directly addressed in
the DOE test procedure, DOE proposed
to adopt more specific instructions on
how each component should be handled
for the purposes of making
representations in 10 CFR part 429 in
the August 2022 NOPR. 87 FR 53302,
53335. Specifically, the proposed
instructions provide manufacturers
clarity on how components should be
treated and how to group individual
models with and without optional
components for the purposes of
representations to reduce burden. Id.
As proposed in the August 2022
NOPR, DOE is handling WSHP
components in two distinct ways in this
final rule to help manufacturers better
understand their options for developing
representations for their differing
product offerings. Id. First, as proposed
in the August 2022 NOPR, the treatment
of some components is specified by the
test procedure to limit their impact on
measured efficiency. Id. For example, a
fresh air damper must be set in the
closed position and sealed during
testing, resulting in a measured
efficiency that would be similar or
identical to the measured efficiency for
a unit without a fresh air damper. Id.
Second, for certain components not
directly addressed in the DOE test
procedure, this final rule adopts the
specific instructions proposed in the
August 2022 NOPR on how each
component should be handled for the
purposes of making representations in
10 CFR part 429. See Id. at 87 FR
53335–53336. Specifically, these
instructions provide manufacturers
clarity on how components should be
treated and how to group individual
models with and without optional
components for the purposes of
representations, in order to reduce
burden. DOE is adopting these
provisions in 10 CFR part 429 to allow
for testing of certain individual models
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that can be used as a proxy to represent
the performance of equipment with
multiple combinations of components.
DOE is adopting provisions expressly
allowing certain models to be grouped
together for the purposes of making
representations and allowing the
performance of a model without certain
optional components to be used as a
proxy for models with any combinations
of the specified components, even if
such components would impact the
measured efficiency of a model. Steam/
hydronic heat coils are an example of
such a component. The efficiency
representation for a model with a steam/
hydronic heat coil is based on the
measured performance of the WSHP as
tested without the component installed
because the steam/hydronic heat coil is
not easily removed from the WSHP for
testing.16 Id.
In this final rule, DOE is adopting
these provisions in 10 CFR part 429 as
proposed to allow for testing of certain
individual models that can be used as
a proxy to represent the performance of
equipment with multiple combinations
of components, though DOE is also
adopting provisions that address
additional components not included in
the August 2022 NOPR, reflecting
comments received in response to the
August 2022 NOPR and provisions in
AHRI 600–2023.
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2. Components Addressed Through Test
Provisions of 10 CFR Part 431, Subpart
F, Appendix C1
In the August 2022 NOPR, DOE
proposed test provisions for specific
components, including all of the
components listed in section D3 of
AHRI 340/360–2022 for which there is
a test procedure action which limits the
impacts on measured efficiency (i.e.,
test procedure provisions specific to the
component that are not addressed by
general provisions in AHRI 340/360–
2022 that negates the component’s
impact on performance). Id. at 87 FR
53336. These provisions specified how
to test a unit with such a component
(e.g., for a unit with hail guards, remove
hail guards for testing). Id. The
proposed test provisions were
consistent with the provision in section
D3 of AHRI 340/360–2022 but included
revisions for further clarity and
specificity (e.g., adding clarifying
provisions for how to test units with
modular economizers as opposed to
units shipped with economizers
installed). Id. Specifically, DOE
16 Note
that in certain cases, as explained further
in section III.G.3.c of this document, the
representation may have to be based on an
individual model with a steam/hydronic coil.
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proposed to require in appendix C1 that
steps be taken during unit set-up and
testing to limit the impacts on the
measurement of these components:
• Desiccant Dehumidification
Components
• Air Economizers
• Fresh Air Dampers
• Power Correction Capacitors
• Ventilation Energy Recovery Systems
(VERS)
• Barometric Relief Dampers
• UV Lights
• Steam/Hydronic Coils
• Refrigerant Reheat
• Fire/Smoke/Isolation Dampers
• Process Heat Recovery/Reclaim Coils/
Thermal Storage.
Id. at 87 FR 53336–53337.
As DOE did not receive any
comments regarding this proposal in
response to the August 2022 NOPR, it is
adopting the provisions as proposed in
this final rule.
3. Components Addressed Through
Representation Provisions of 10 CFR
429.43
In the August 2022 NOPR, consistent
with the Commercial HVAC Term Sheet
and the Commercial HVAC Enforcement
Policy, DOE proposed provisions that
explicitly allow representations for
individual models with certain
components to be based on testing for
individual models without those
components and proposed a table
(‘‘Table 6 to Paragraph (a)(3)(v)(A)’’) 17
at 10 CFR 429.43(a)(3) listing the
components for which these provisions
would apply. Id. at 87 FR 53337. There
are three components specified
explicitly for WSHPs in the Commercial
HVAC Enforcement Policy that are not
included in section D3 of AHRI 340/
360–2022: (1) Condenser Pumps/Valves/
Fittings; (2) Condenser Water Reheat;
and (3) Electric Resistance Heaters. Id.
DOE tentatively concluded that the
inclusion of these components as
optional components for WSHPs is
appropriate, except for electric
resistance heaters. Id. DOE tentatively
determined that electric resistance
heaters would have a negligible effect
on tested efficiency as they would be
turned off for test and not impose a
significant pressure drop. Id. DOE
proposed the following components be
listed in Table 6 to Paragraph
(a)(3)(v)(A):
• Desiccant Dehumidification
Components,
17 DOE notes that in the August 2022 NOPR, DOE
referred to this table as ‘‘Table 1 to Paragraph
(a)(3)(ii)(A) .’’ Due to the publication of other
regulatory documents, DOE is now referring to this
Table as ‘‘Table 6 to Paragraph (a)(3)(v)(A).’’
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• Air Economizers,
• Ventilation Energy Recovery Systems
(VERS),
• Steam/Hydronic Heat Coils,
• Refrigerant Reheat, Fire/Smoke/
Isolation Dampers,
• Powered Exhaust/Powered Return Air
Fans,
• Sound Traps/Sound Attenuators,
• Process Heat Recovery/Reclaim Coils/
Thermal Storage,
• Indirect/Direct Evaporative Cooling of
Ventilation Air,
• Condenser Pumps/Valves/Fittings,
• Condenser Water Reheat,
• Grill Options,
• Non-Standard Indoor Fan Motors.
Id.
Additionally, DOE proposed to
specify that the basic model
representation must be based on the
least efficient individual model that is a
part of the basic model and clarified
how this long-standing basic model
provision interacts with the component
treatment in 10 CFR 429.43 that was
proposed. Id. DOE proposed clarifying
instructions for instances when
individual models within a basic model
may have more than one of the specified
components and there may be no
individual model without any of the
specified components. Id. DOE
proposed the concept of an ‘‘otherwise
comparable model group’’ (‘‘OCMG’’).
Id.
As discussed in the August 2022
NOPR, an OCMG is a group of
individual models within the basic
model that do not differ in components
that affect energy consumption as
measured according to the applicable
test procedure other than the specific
components listed in Table 6 to
Paragraph (a)(3)(v)(A) but may include
individual models with any
combination of such specified
components. Id. Therefore, a basic
model can be composed of multiple
OCMGs, each representing a unique
combination of components that affect
energy consumption as measured
according to the applicable test
procedure, other than the specified
excluded components listed in Table 6
to Paragraph (a)(3)(v)(A). Id. For
example, a manufacturer might include
two tiers of control system within the
same basic model, in which one of the
control systems has sophisticated
diagnostics capabilities that require a
more powerful control board with a
higher wattage input. Id. WSHP
individual models with the ‘‘standard’’
control system would be part of OCMG
A, while individual models with the
‘‘premium’’ control system would be
part of a different OCMG B, because the
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control system is not one of the
specified exempt components listed in
Table 6 to Paragraph (a)(3)(v)(A). Id.
However, both OCMGs may include
different combinations of specified
exempt components. Id. Also, both
OCMGs may include any combination
of characteristics that do not affect the
efficiency measurement, such as paint
color. Id.
Further discussed in the August 2022
NOPR, an OCMG is used to determine
which individual models are used to
determine a represented value. Id.
Specifically, when identifying the
individual model within an OCMG for
the purpose of determining a
representation for the basic model, only
the individual model(s) with the least
number (which could be zero) of the
specific components listed in Table 6 to
Paragraph (a)(3)(v)(A) is considered. Id.
This clarifies which individual models
are exempted from consideration for
determination of represented values in
the case of an OCMG with multiple
specified components and no individual
models with zero specific components
listed in Table 6 to (a)(3)(v)(A) (i.e.,
models with a number of specific
components listed in Table 6 to
(a)(3)(v)(A) greater than the least
number in the OCMG are exempted). Id.
In the case that the OCMG includes an
individual model with no specific
components listed in Table 6 to
Paragraph (a)(3)(v)(A), then all
individual models in the OCMG with
specified components would be
exempted from consideration. Id. The
least-efficient individual model across
the OCMGs within a basic model would
be used to determine the representation
of the basic model. Id. In the case where
there are multiple individual models
within a single OCMG with the same
non-zero least number of specified
components, the least efficient of these
would be considered. Id.
In the August 2022 NOPR, DOE relied
on the term ‘‘comparable’’ as opposed to
‘‘identical’’ to indicate that for the
purpose of representations, the
components that impact energy
consumption as measured by the
applicable test procedure are the
relevant components to consider. Id. In
other words, differences that do not
impact energy consumption, such as
unit color and presence of utility
outlets, would not warrant separate
OCMGs. Id.
The use of the OCMG concept results
in the represented values of
performance that are representative of
the individual model(s) with the lowest
efficiency found within the basic model,
excluding certain individual models
with the specific components listed in
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Table 6 to Paragraph (a)(3)(v)(A). Id. at
87 FR 53337–53338. Further, the
approach, as proposed, was structured
to more explicitly address individual
models with more than one of the
specific components listed in Table 6 to
Paragraph (a)(3)(v)(A), as well as
instances in which there is no
comparable model without any of the
specified components. Id. at 87 FR
53338. DOE developed a document of
examples to illustrate the approach
proposed in the August 2022 NOPR for
determining represented values for
WSHPs with specific components, and
in particular the OCMG concept. See
EERE–2017–BT–TP–0029; 87 FR 53302,
53338.
In the August 2022 NOPR, DOE
proposed provisions in 10 CFR
429.43(a)(3)(v)(A) that included each of
the components specified in section D3
of AHRI 340/360–2022 for which the
test provisions for testing a unit with
these components may result in
differences in ratings compared to
testing a unit without these
components, except for the following
features: (1) Evaporative Pre-cooling of
Condenser Intake Air; (2) Non-Standard
Ducted Condenser Fans; and (3) Coated
Coils. 87 FR 53302, 53338–53339.
In response to the August 2022 NOPR,
ClimateMaster commented that it agrees
with DOE’s several proposals on this
issue, but it believes that Table 6 in
paragraph (a)(3) should include
additional components, specifically
water-side economizers and high
effectiveness filters. (ClimateMaster, No.
22 at p. 12) ClimateMaster
recommended that DOE create a
national deviation of ISO 13256–1:1998
that adopts the proposed language with
modifications to include water-side
economizers and high effectiveness
indoor filters. (Id.) WaterFurnace
commented that the proposals may
work for large motors but noted that the
small volume of these larger motors
would not justify regulation efforts and
AHRI 340/360 omits smaller motors.
(WaterFurnace, No. 20 at p. 10)
With regards to the comment from
ClimateMaster that waterside
economizers and high effectiveness
filters should be included in Table 6 to
Paragraph (a)(3)(v)(A), DOE notes that
the impact of high effectiveness filters
can be entirely mitigated by testing with
a standard filter, which is required by
section 5.4.5 of AHRI 600–2023.
Therefore, DOE has concluded that
treatment as specific components in
representation provisions in 10 CFR
429.43 is not warranted for high
effectiveness filters. With regards to
waterside economizers, DOE has
included waterside economizers and
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desuperheaters in the updated Table 6
to Paragraph (a)(3)(v)(A) adopted in this
final rule, as DOE has determined that
it is appropriate to make representations
for WSHPs without these components
present, consistent with the inclusion of
these components in section D3 of AHRI
600–2023.
With regard to the comment from
WaterFurnace that only a small portion
of the market has larger motors and
therefore that they are not worth
regulating, DOE notes that the approach
for non-standard high-static indoor fan
motors (as proposed in the August 2022
NOPR and included in AHRI 600–2023)
does not expand the scope of
regulations to cover equipment with
higher-static motors. Equipment that
meets the DOE definition of WSHP is
covered equipment, regardless of the
size of indoor fan motor. The adopted
approach reduces burden to
manufacturers by allowing grouping of
WSHP individual models with nonstandard high-static indoor fan motors
in the same basic model as
corresponding individual models with
standard indoor fan motors (and thus
rating all individual models in the basic
model based on performance with the
standard indoor fan motor), as long as
the non-standard high-static indoor fan
motor has the same or better relative
efficiency performance as the standard
motor included in the individual model
with the standard indoor fan motor.
4. Enforcement Provisions of 10 CFR
429.134
In the August 2022 NOPR, consistent
with the Commercial HVAC Term Sheet
and the Commercial HVAC Enforcement
Policy, DOE proposed provisions in 10
CFR 429.134(dd)(2) 18 regarding how
DOE would assess compliance for basic
models that include individual models
distributed in commerce if DOE cannot
obtain for testing individual models
without the components that are the
basis of representation. 87 FR 53302,
53339. Specifically, DOE proposed that
if a basic model includes individual
models with components listed at Table
6 to Paragraph (a)(3)(v)(A) and DOE is
not able to obtain an individual model
with the least number of those
components within an OCMG (as
defined in 10 CFR 429.43(a)(3) and
discussed in section III.G.3.b of this
final rule), DOE may test any individual
model within the OCMG. Id.
In response to the August 2022 NOPR,
ClimateMaster stated that it disagrees
18 DOE notes that in the August 2022 NOPR, DOE
referred to this section as ‘‘10 CFR 429.134(t)(2).’’
Due to the publication of other regulatory
documents, DOE is now referring to this section as
‘‘10 CFR 429.134(dd)(2).’’
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with the provisions proposed in 10 CFR
429.134(dd)(2) in the August 2022
NOPR, stating that most WSHPs are
built for specific orders based on given
configurations or options.
(ClimateMaster, No. 22 at p. 12)
ClimateMaster commented that if DOE
requires an individual model with the
lowest number of specific components,
it may not be available to test, and that
the proposal would allow DOE testing
with a model that includes the specific
component. (Id.) ClimateMaster
recommended that DOE instead allow a
manufacturer to provide an individual
model with the least number of specific
components within a specific and
agreed-upon timeframe (i.e., rather than
testing a model that includes a specific
component). (Id.)
With regards to the comment from
ClimateMaster, the provisions proposed
in the August 2022 NOPR at 10 CFR
429.134(dd)(2) specify that DOE may
test any individual model within the
otherwise comparable model group if
DOE is not able to obtain an individual
model with the least number (which
could be zero) of those components
within the otherwise comparable model
group. DOE will attempt to obtain a
model with the least number of those
components of specific components
listed at Table 6 to Paragraph
(a)(3)(v)(A). However, if DOE is unable
to obtain such a model, DOE must retain
the option to conduct assessment testing
on an available model, and thus, in this
final rule, DOE is adopting the
provisions from the NOPR as proposed,
at 10 CFR 429.134(dd)(2).
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H. Represented Values and Enforcement
1. Cooling Capacity
For WSHPs, cooling capacity
determines equipment class, which in
turn determines the applicable energy
conservation standard. 10 CFR 431.97.
In the August 2022 NOPR, DOE noted
that while cooling capacity is a required
represented value for WSHPs, DOE does
not currently specify provisions for
WSHPs regarding how close the
represented value of cooling capacity
must be to the tested or AEDMsimulated cooling capacity, or whether
DOE will use measured or certified
cooling capacity to determine
equipment class for enforcement testing.
87 FR 53302, 53339. DOE proposed to
add the following provisions regarding
cooling capacity for WSHPs: (1) a
requirement that the represented
cooling capacity be between 95 percent
and 100 percent of the tested or AEDMsimulated cooling capacity; and (2) an
enforcement provision stating that DOE
would use the mean of measured
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cooling capacity values from testing,
rather than the certified cooling
capacity, to determine the applicable
standards. Id.
In response to the August 2022 NOPR,
ClimateMaster commented that it
supports DOE’s proposal for the
published capacity to fall within 95
percent to 100 percent of the tested
value or the value found through the
AEDM. (ClimateMaster, No. 22 at p. 12)
WaterFurnace commented that it saw no
problem with DOE’s proposal.
(WaterFurnace, No. 20 at p. 10) MIAQ
commented that it supports the
tolerance of 5 percent below the rated/
marked capacity, but not with the 100percent limit. (MIAQ, No. 23 at p. 8)
MIAQ stated that manufacturers must
account for many tolerances in their
system, causing them to rate their units
conservatively, and this conservative
rating will not impact customers
because the unit will perform better
than advertised. (Id.)
In response to the comment from
MIAQ, DOE notes that the proposed
cooling capacity provisions specify that
the represented cooling capacity be
between 95 percent and 100 percent of
the tested or AEDM-simulated cooling
capacity, which allows for conservative
rating up to 5 percent—i.e., the
represented cooling capacity may be 5
percent lower than the tested or AEDMsimulated cooling capacity. MIAQ’s
comment suggests MIAQ interpreted the
proposal to mean the tested or
simulated capacity cannot exceed 100
percent of represented capacity, which
would not allow conservative ratings.
However, DOE has concluded that
MIAQ’s concern that conservative rating
should be allowed is addressed in the
proposed provisions because the cooling
capacity provisions explicitly allow
conservative ratings up to 5 percent.
Therefore, for the reasons discussed in
the August 2022 NOPR and previously
in this section, DOE is adopting the
cooling capacity representation and
enforcement provisions as proposed at
10 CFR 429.43(a)(3)(v)(B) and 10 CFR
429.134(dd)(1), respectively.
2. Enforcement of IEER
In the August 2022 NOPR, DOE
proposed two options for determination
of IEER—‘‘option 1’’ based on testing at
the EWTs specified in AHRI 340/360–
2022 for determining IEER, and ‘‘option
2’’ based on testing at the EWTs
specified in ISO 13256–1:1998 and
interpolating/extrapolating performance
to the EWTs specified in AHRI 340/360–
2022. 87 FR 53302, 53339. For
assessment or enforcement testing, DOE
proposed provisions in 10 CFR
429.134(t)(3) specifying that that the
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Department would determine IEER
according to the ‘‘Option 1’’ approach,
unless the manufacturer has specified
that the ‘‘Option 2’’ approach should be
used for the purposes of enforcement, in
which case the Department would
determine IEER according to the
‘‘Option 2’’ approach. Id.
As discussed in section III.E.1 of this
final rule, DOE is not adopting two
methods for determining IEER, and is
instead adopting a single method for
determining IEER by incorporating by
reference AHRI 600–2023 into appendix
C1. Because this final rule includes only
one method for determining IEER, the
proposed enforcement provisions for the
method of determination of IEER are no
longer applicable, and DOE is not
adopting the proposed provisions.
I. Test Procedure Costs
EPCA requires that the test
procedures for commercial package air
conditioning and heating equipment,
including WSHPs, be those generally
accepted industry testing procedures or
rating procedures developed or
recognized by either AHRI or ASHRAE,
as referenced in ASHRAE 90.1. (42
U.S.C. 6314(a)(4)(A)) Further, if such an
industry test procedure is amended,
DOE must amend 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 an
amended test procedure would not meet
the requirements in 42 U.S.C.
6314(a)(2)–(3) related to representative
use and test burden. (42 U.S.C.
6314(a)(4)(B)) EPCA also requires that,
at least once every 7 years, DOE
evaluate test procedures for each type of
covered equipment, including WSHPs,
to determine whether amended test
procedures would more accurately or
fully comply with the requirements for
the test procedures to not be unduly
burdensome to conduct and be
reasonably designed to produce test
results that reflect energy efficiency,
energy use, and estimated operating
costs during a representative average
use cycle. (42 U.S.C. 6314(a)(1)
In the August 2022 NOPR, DOE
proposed to reorganize the current test
procedure in proposed appendix C and
to adopt generally through
incorporation by reference the industry
standard AHRI 340/360–2022 in
proposed appendix C1. 87 FR 53302,
53340. The proposed amended test
procedure in the proposed appendix C1
would rely on the IEER metric. Id. DOE
tentatively determined that the
proposed amended test procedure for
WSHPs in appendix C1 would be
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representative of an average use cycle
and would not be unduly burdensome
for manufacturers to conduct. Id. DOE
also proposed to increase the scope of
applicability of the test procedure to
include all WSHPs with full-load
cooling capacity between 135,000 Btu/h
and 760,000 Btu/h. Id. As part of the
August 2022 NOPR, DOE presented
estimates of the test costs associated
with these proposals. Id. DOE requested
comment on its understanding of the
impact of the test procedure proposals
in this NOPR. Id.
In response to the August 2022 NOPR,
ClimateMaster commented that it
qualifies as a small business under the
Small Business Administration (‘‘SBA’’)
guidelines and that the extra burden to
rate through two programs, as would be
required under AHRI 340/360–2022, is
too costly for small businesses.
(ClimateMaster, No. 22 at pp. 13–14)
ClimateMaster recommended that DOE
should instead use data created through
the national deviation to ISO 13256–
1:1998 to interpolate per the procedure
given in AHRI 600. (Id. at p. 14)
WaterFurnace commented that that
the test procedure proposed in the
August 2022 NOPR referencing AHRI
340/360 (including changes to ESP
requirements, flows, and entering air
conditions) would approximately
double its testing and certification
management labor and costs.
(WaterFurnace, No. 20 at p.10)
In this final rule DOE is relocating the
current DOE test procedure for WSHPs
to appendix C without change. The test
procedure adopted in appendix C for
measuring EER and COP will result in
no change in testing practices or burden.
As discussed in section III.D of this
final rule, DOE is incorporating by
referencing AHRI 600–2023 into
appendix C1 for measuring the IEER and
ACOP metrics. DOE has determined that
the amended test procedure is
reasonably designed to produce results
that are representative of the energy
efficiency of that covered equipment
during an average use cycle and is not
unduly burdensome to conduct. The use
of appendix C1 will not be required
until the compliance date of any
amended standards denominated in
terms of IEER and ACOP, should DOE
adopt such standards. DOE has
concluded that the incorporation by
reference AHRI 600–2023, the latest
industry consensus test procedure for
WSHPs, renders moot any expressed
concerns related to the costs with rating
to AHRI 340/360.
In this final rule, DOE estimates that
the cost for units less than 135,000 Btu/
h for third-party laboratory testing
according to appendix C1 for measuring
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IEER and ACOP to be $3,700 for single
speed units, $5,950 for two stage units,
and $8,200 for variable speed units. The
difference in test cost is attributable to
the varying number of tests (i.e. 3, 6, or
9) required to determine IEER for units
with different compressor types.
Additionally, DOE is increasing the
scope of applicability of the test
procedure to include all WSHPs with
full-load cooling capacity between
135,000 Btu/h and 760,000 Btu/h. DOE
estimates the cost for third-party lab
testing of large and very large WSHPs
according to the test procedure adopted
in appendix C1 for measuring IEER and
ACOP to be $10,100 for single speed
units, $15,500 for two stage units, and
$20,900 for variable speed units. DOE
estimates a substantially higher cost for
larger WSHPs because they are generally
more difficult to set up due to size and
larger units typically would need to be
set up in larger test chambers with more
limited availability.
As discussed in the August 2022
NOPR, in accordance with 10 CFR
429.70, WSHP manufacturers may elect
to use AEDMs. 87 FR 53302, 53340. 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 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. In the August
2022 NOPR, DOE sought specific
feedback on the estimated costs to rate
WSHP models with an AEDM. Id.
In response to the August 2022 NOPR,
MIAQ agreed that AEDMs must be
acceptable but stated that the need for
AEDMs to be representative requires a
lot of testing by manufacturers. (MIAQ,
No. 23 at p. 9) MIAQ commented that
DOE’s proposal to include WSHP’s with
cooling capacities up to 760,000 Btu/h
in scope increases the time and cost
associated with the testing required to
validate the AEDM. (Id.) MIAQ
recommended that if an AEDM-rated
unit were to fail a validation test, that
only the failed unit should be derated
rather than the entire AEDM-rated
series. (Id.) MIAQ stated that the cost to
test a full 30-ton WSHP qualification is
around $50,000-$60,000 per basic model
group, and that developing an AEDM
model with sufficient trust would
require as much as $1 million in capital
investment. (Id.)
DOE estimates the per-manufacturer
cost to develop and validate an AEDM
to be used for all WSHP equipment with
a cooling capacity less than 135,000
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Btu/h would be $12,050 for single stage
units, $14,300 for two stage units, and
$16,550 for variable speed units. DOE
estimates the per-manufacturer cost to
develop and validate an AEDM to be
used for all WSHPs with a cooling
capacity between 135,000 Btu/h and
760,000 Btu/h would be $26,000 for
single stage units, $31,400 for two stage
units, and $36,800 for variable speed
units. DOE estimates an additional cost
of approximately $41 per basic model
for determining energy efficiency using
the validated AEDM.19
DOE disagrees with MIAQ’s claims on
the burden of AEDM development for
WSHPs with a cooling capacity greater
than 135,000 Btu/h. As discussed, based
on quotes from third-party test
laboratories, DOE estimates a per-unit
test cost to the amended test procedure
adopted in appendix C1 of $10,000–
$21,000 for WSHPs with a cooling
capacity greater than 135,000 Btu/h. Per
10 CFR 429.70(c)(2), validation of an
AEDM requires testing a minimum of
only two basic models. Based on DOE’s
observation of the prevalence of use of
AEDMs for WSHP and similar
equipment for which energy
conservation standards currently apply
(i.e., for equipment with a cooling
capacity no greater than 135,000 Btu/h),
DOE expects most WSHP manufacturers
already have AEDMs for simulating
WSHP performance. Further, as
discussed in section III.A.1 of this final
rule, the manufacturer literature for all
identified model lines of WSHPs with a
cooling capacity greater than 135,000
Btu/h includes efficiency
representations that are explicitly based
on ISO 13256–1:1998, indicating that all
manufacturers of this equipment already
have the capability to generate
efficiency representations for this
equipment consistent with an industry
consensus test procedure for WSHPs.
Regarding the outcomes of failed DOE
verification testing, in this final rule,
DOE is not amending its regulations for
AEDM verification, which are
applicable to all equipment categories
that may use AEDMs. DOE notes that 10
CFR 429.70(c)(5)(viii) outlines required
manufacturer actions with regard to
AEDM use if basic models certified with
AEDMs are determined to have invalid
19 DOE estimated initial costs to validate an
AEDM assuming 80 hours of general time to
develop an AEDM based on existing simulation
tools and 16 hours to validate two basic models
within that AEDM at the cost of an engineering
technician wage of $41 per hour plus the cost of
third-party physical testing of two units per
validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per
basic model cost to determine efficiency using an
AEDM assuming 1 hour per basic model at the cost
of an engineering technician wage of $41 per hour.
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ratings. Given that most WSHP
manufacturers are AHRI members and
that DOE is incorporating by reference
the prevailing industry test procedure
that was established for use in AHRI’s
certification program, DOE expects that
manufacturers will already be testing
using AHRI 600–2023 in the timeframe
of any potential future energy
conservation standards in terms of IEER
and ACOP. Based on this, DOE has
determined that the test procedure
amendments adopted in this final rule
are not expected to increase the testing
burden on WSHP manufacturers that are
AHRI members. For the minority of
WSHP manufacturers that are not
members of AHRI, the test procedure
amendments may have costs associated
with model re-rating, to the extent that
the manufacturers would not already be
testing to the updated industry test
procedure. Additionally, DOE has
determined that the test procedure
amendments will not require
manufacturers to redesign any of the
covered equipment, will not require
changes to how the equipment is
manufactured, and will not impact the
utility of the equipment.
J. Effective and Compliance Dates
The effective date for the adopted test
procedure amendments will be 30 days
after publication of this final rule in the
Federal Register. EPCA prescribes that,
for the equipment at issue, all
representations of energy efficiency and
energy use, including those made on
marketing materials and product labels,
must be made in accordance with an
amended test procedure, beginning 360
days after publication of this final rule
in the Federal Register. (42 U.S.C.
6314(d)(1))
Starting 360 days after publication of
a test procedure final rule in the Federal
Register, and prior to the compliance
date of amended standards for WSHPs
that rely on IEER and ACOP,
representations must be based on the
test procedure in appendix C. WSHPs
are not required to be tested according
to the test procedure in appendix C1
(resulting in the IEER and ACOP
metrics) until the compliance date of
amended energy conservation standards
denominated in terms of the IEER and
ACOP metrics, should DOE adopt such
standards.
Any voluntary representations of IEER
and ACOP made prior to the compliance
date of amended standards for WSHPs
that rely on IEER and ACOP must be
based on the test procedure in appendix
C1 starting 360 days after publication of
such a test procedure final rule in the
Federal Register, and manufacturers
may use appendix C1 to certify
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compliance with any amended
standards based on IEER and ACOP, if
adopted, prior to the applicable
compliance date for those energy
conservation standards.
IV. Procedural Issues and Regulatory
Review
A. Review Under Executive Orders
12866, 13563, and 14094
Executive Order (‘‘E.O.’’) 12866,
‘‘Regulatory Planning and Review,’’ 58
FR 51735 (Oct. 4, 1993), as
supplemented and reaffirmed by E.O.
13563, ‘‘Improving Regulation and
Regulatory Review,’’ 76 FR 3821 (Jan.
21, 2011) and amended by E.O. 14094,
‘‘Modernizing Regulatory Review,’’ 88
FR 21879 (April 11, 2023), requires
agencies, to the extent permitted by law,
to: (1) propose or adopt a regulation
only upon a reasoned determination
that its benefits justify its costs
(recognizing that some benefits and
costs are difficult to quantify); (2) tailor
regulations to impose the least burden
on society, consistent with obtaining
regulatory objectives, taking into
account, among other things, and to the
extent practicable, the costs of
cumulative regulations; (3) select, in
choosing among alternative regulatory
approaches, those approaches that
maximize net benefits (including
potential economic, environmental,
public health and safety, and other
advantages; distributive impacts; and
equity); (4) to the extent feasible, specify
performance objectives, rather than
specifying the behavior or manner of
compliance that regulated entities must
adopt; and (5) identify and assess
available alternatives to direct
regulation, including providing
economic incentives to encourage the
desired behavior, such as user fees or
marketable permits, or providing
information upon which choices can be
made by the public. DOE emphasizes as
well that E.O. 13563 requires agencies to
use the best available techniques to
quantify anticipated present and future
benefits and costs as accurately as
possible. In its guidance, the Office of
Information and Regulatory Affairs
(‘‘OIRA’’) in the Office of Management
and Budget (‘‘OMB’’) has emphasized
that such techniques may include
identifying changing future compliance
costs that might result from
technological innovation or anticipated
behavioral changes. For the reasons
stated in this preamble, this final
regulatory action is consistent with
these principles.
Section 6(a) of E.O. 12866 also
requires agencies to submit ‘‘significant
regulatory actions’’ to OIRA for review.
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OIRA has determined that this final
regulatory action does not constitute a
‘‘significant regulatory action’’ under
section 3(f) of E.O. 12866. Accordingly,
this action was not submitted to OIRA
for review under E.O. 12866.
B. Review Under the Regulatory
Flexibility Act
The Regulatory Flexibility Act
(‘‘RFA’’) (5 U.S.C. 601 et seq.) requires
preparation of a final regulatory
flexibility analysis (‘‘FRFA’’) 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 E.O. 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: www.energy.gov/gc/
office-general-counsel. DOE reviewed
this final rule to amend the test
procedure for WSHPs under the
provisions of the RFA and the policies
and procedures published on February
19, 2003.
As part of the August 2022 NOPR,
DOE conducted its initial regulatory
flexibility analysis (‘‘IRFA’’). The
following sections outline DOE’s
determination that this final rule does
not have a ‘‘significant economic impact
on a substantial number of small
entities,’’ and that the preparation of a
FRFA is not warranted.
DOE is amending the test procedure
for WSHPs to satisfy its statutory
obligations under EPCA. (42 U.S.C.
6314(a)(1)(A))
In this final rule, DOE is establishing
new appendices C and C1 to subpart F
of part 431. The current DOE test
procedure for WSHPs is relocated to
appendix C without change. The
amended test procedure for WSHPs is
established in a new appendix C1,
which includes the following amended
test procedure requirements for WSHPs
for measuring the updated efficiency
metrics: (1) IEER for WSHPs using the
methods from AHRI 600–2023; and (2)
ACOP using the methods specified in
AHRI 600–2023. Use of the amended
test procedure in appendix C1 will not
be required until such time as
compliance is required with amended
energy conservation standards for
WSHPs denominated in terms of IEER
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and ACOP, should DOE adopt such
standards.
Additionally, DOE is expanding the
scope of the test procedure to include
WSHPs with capacities between 135,000
and 760,000 Btu/h, as well as specifying
the components that must be present for
testing and amending certain provisions
related to representations and
enforcement in 10 CFR part 429.
DOE uses the Small Business
Administration (‘‘SBA’’) small business
size standards to determine whether
manufacturers qualify as ‘‘small
businesses,’’ which are listed by the
North American Industry Classification
System (‘‘NAICS’’).20 The SBA
considers a business entity to be small
business if, together with its affiliates, it
employs less than a threshold number of
workers specified in 13 CFR part 121.
WSHP manufacturers, who produce the
equipment covered by this rule, are
classified under NAICS code 333415,
‘‘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.
This employee threshold includes all
employees in a business’s parent
company and any other subsidiaries.
DOE utilized the California Energy
Commission’s Modernized Appliance
Efficiency Database System
(‘‘MAEDbS’’) 21 and the DOE’s
Certification Compliance Database
(‘‘CCD’’) 22 in identifying manufacturers.
DOE screened out private labelers
because original equipment
manufacturers (‘‘OEMs’’) would likely
be responsible for any costs associated
with testing to the amended test
procedure. As a result of this inquiry,
DOE identified a total of 25 OEMs of
WSHPs in the United States affected by
this rulemaking. DOE screened out
companies that do not meet the
definition of a ‘‘small business’’ or are
foreign owned without substantive
domestic operations. DOE used
subscription-based business information
tools to determine headcount and
revenue of each business. Of the 25
OEMs of WSHPs, DOE identified 6 as
small, domestic manufacturers.
20 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 July 16, 2021).
21 MAEDbS is available at
www.cacertappliances.energy.ca.gov/Pages/Search/
AdvancedSearch.aspx (Last accessed Dec. 1, 2021).
22 Certified equipment in the CCD are listed by
product class and can be accessed at
www.regulations.doe.gov/certification-data/ (Last
accessed May 1, 2023).
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Of the 6 small, domestic
manufacturers identified, all certify
their WSHP models in the AHRI
Certification Directory for WSHPs.
AHRI has published a new industry
test standard for WSHPs, titled AHRI
Standard 600, ‘‘2023 Standard for
Performance Rating of Water/Brine to
Air Heat Pump Equipment’’ (‘‘AHRI
600–2023’’). DOE presumes AHRI’s
certification program will require rating
based on AHRI 600–2023 to develop the
IEER and ACOP metrics. As a result, the
test procedure amendments adopted in
this final rule will not add any
additional testing burden to
manufacturers that already certify
WSHPs to AHRI’s certification program.
Accordingly, DOE does not expect that
the identified small business
manufacturers, all of whom participate
in AHRI’s certification program, would
see increased testing costs as a result of
this rulemaking.
Additionally, DOE notes these test
procedure amendments will only affect
voluntary representations. There is no
existing energy conservation standard
that requires manufacturer to certify to
WSHP efficiency in terms of IEER and
ACOP to DOE. Certification based on
IEER and ACOP would only be required
if and when DOE establishes energy
conservation standards based on those
metrics for WSHPs.
Therefore, for the reasons stated in the
preceding paragraphs, DOE concludes
and certifies that the cost effects
accruing from this test procedure final
rule would not have a ‘‘significant
economic impact on a substantial
number of small entities,’’ and that the
preparation of a FRFA is not warranted.
DOE has submitted a certification and
supporting statement of factual basis to
the Chief Counsel for Advocacy of the
Small Business Administration for
review under 5 U.S.C. 605(b).
C. Review Under the Paperwork
Reduction Act of 1995
Manufacturers of WSHPs must certify
to DOE that their products comply with
any applicable energy conservation
standards. To certify compliance,
manufacturers must first obtain test data
for their products according to the DOE
test procedures, including any
amendments adopted for those test
procedures. DOE has established
regulations for the certification and
recordkeeping requirements for all
covered consumer products and
commercial equipment, including
WSHPs. (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
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Reduction Act (‘‘PRA’’). This
requirement has been approved by OMB
under OMB control number 1910–1400.
Public reporting burden for the
certification is estimated to average 35
hours per response, including the time
for reviewing instructions, searching
existing data sources, gathering and
maintaining the data needed, and
completing and reviewing the collection
of information.
DOE is not amending the certification
or reporting requirements for WSHPs in
this final rule. Instead, DOE may
consider proposals to amend the
certification requirements and reporting
for WSHPs under a separate rulemaking
regarding appliance and equipment
certification. DOE will address changes
to OMB Control Number 1910–1400 at
that time, as necessary.
Notwithstanding any other provision
of the law, no person is required to
respond to, nor shall any person be
subject to a penalty for failure to comply
with, a collection of information subject
to the requirements of the PRA, unless
that collection of information displays a
currently valid OMB Control Number.
D. Review Under the National
Environmental Policy Act of 1969
In this final rule, DOE establishes test
procedure amendments that it expects
will be used to develop and implement
future energy conservation standards for
WSHPs. DOE has determined that this
rule falls into a class of actions that are
categorically excluded from review
under the National Environmental
Policy Act of 1969 (42 U.S.C. 4321 et
seq.) and DOE’s implementing
regulations at 10 CFR part 1021.
Specifically, DOE has determined that
adopting test procedures for measuring
energy efficiency of consumer products
and industrial equipment is consistent
with activities identified in 10 CFR part
1021, appendix A to subpart D, A5 and
A6. Accordingly, neither an
environmental assessment nor an
environmental impact statement is
required.
E. Review Under Executive Order 13132
Executive Order 13132, ‘‘Federalism,’’
64 FR 43255 (August 4, 1999), imposes
certain requirements on agencies
formulating and implementing policies
or regulations that preempt State law or
that have federalism implications. The
Executive order requires agencies to
examine the constitutional and statutory
authority supporting any action that
would limit the policymaking discretion
of the States and to carefully assess the
necessity for such actions. The
Executive order also requires agencies to
have an accountable process to ensure
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meaningful and timely input by State
and local officials in the development of
regulatory policies that have federalism
implications. On March 14, 2000, DOE
published a statement of policy
describing the intergovernmental
consultation process it will follow in the
development of such regulations. 65 FR
13735. DOE examined this final rule
and determined that it will not have a
substantial direct effect on the States, on
the relationship between the national
government and the States, or on the
distribution of power and
responsibilities among the various
levels of government. EPCA governs and
prescribes Federal preemption of State
regulations as to energy conservation for
the products that are the subject of this
final rule. States can petition DOE for
exemption from such preemption to the
extent, and based on criteria, set forth in
EPCA. (42 U.S.C. 6316(a) and 42 U.S.C.
6316(b); 42 U.S.C. 6297(d)) No further
action is required by Executive Order
13132.
ddrumheller on DSK120RN23PROD with RULES2
F. Review Under Executive Order 12988
Regarding the review of existing
regulations and the promulgation of
new regulations, section 3(a) of
Executive Order 12988, ‘‘Civil Justice
Reform,’’ 61 FR 4729 (Feb. 7, 1996),
imposes on Federal agencies the general
duty to adhere to the following
requirements: (1) eliminate drafting
errors and ambiguity; (2) write
regulations to minimize litigation; (3)
provide a clear legal standard for
affected conduct rather than a general
standard; and (4) promote simplification
and burden reduction. Section 3(b) of
Executive Order 12988 specifically
requires that Executive agencies make
every reasonable effort to ensure that the
regulation (1) clearly specifies the
preemptive effect, if any; (2) clearly
specifies any effect on existing Federal
law or regulation; (3) provides a clear
legal standard for affected conduct
while promoting simplification and
burden reduction; (4) specifies the
retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses
other important issues affecting clarity
and general draftsmanship under any
guidelines issued by the Attorney
General. Section 3(c) of Executive Order
12988 requires Executive agencies to
review regulations in light of applicable
standards in sections 3(a) and 3(b) to
determine whether they are met or it is
unreasonable to meet one or more of
them. DOE has completed the required
review and determined that, to the
extent permitted by law, this final rule
meets the relevant standards of
Executive Order 12988.
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G. Review Under the Unfunded
Mandates Reform Act of 1995
Title II of the Unfunded Mandates
Reform Act of 1995 (‘‘UMRA’’) requires
each Federal agency to assess the effects
of Federal regulatory actions on State,
local, and Tribal governments and the
private sector. Public Law 104–4, sec.
201 (codified at 2 U.S.C. 1531). For a
regulatory action resulting in a rule that
may cause the expenditure by State,
local, and Tribal governments, in the
aggregate, or by the private sector of
$100 million or more in any one year
(adjusted annually for inflation), section
202 of UMRA requires a Federal agency
to publish a written statement that
estimates the resulting costs, benefits,
and other effects on the national
economy. (2 U.S.C. 1532(a), (b)) The
UMRA also requires a Federal agency to
develop an effective process to permit
timely input by elected officers of State,
local, and Tribal governments on a
proposed ‘‘significant intergovernmental
mandate,’’ and requires an agency plan
for giving notice and opportunity for
timely input to potentially affected
small governments before establishing
any requirements that might
significantly or uniquely affect small
governments. On March 18, 1997, DOE
published a statement of policy on its
process for intergovernmental
consultation under UMRA. 62 FR
12820; also available at
www.energy.gov/gc/office-generalcounsel. DOE examined this final rule
according to UMRA and its statement of
policy and determined that the rule
contains neither an intergovernmental
mandate, nor a mandate that may result
in the expenditure of $100 million or
more in any year, so these requirements
do not apply.
H. Review Under the Treasury and
General Government Appropriations
Act, 1999
Section 654 of the Treasury and
General Government Appropriations
Act, 1999 (Pub. L. 105–277) requires
Federal agencies to issue a Family
Policymaking Assessment for any rule
that may affect family well-being. This
final rule will not have any impact on
the autonomy or integrity of the family
as an institution. Accordingly, DOE has
concluded that it is not necessary to
prepare a Family Policymaking
Assessment.
I. Review Under Executive Order 12630
DOE has determined, under Executive
Order 12630, ‘‘Governmental Actions
and Interference with Constitutionally
Protected Property Rights’’ 53 FR 8859
(March 18, 1988), that this regulation
PO 00000
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84225
will not result in any takings that might
require compensation under the Fifth
Amendment to the U.S. Constitution.
J. Review Under Treasury and General
Government Appropriations Act, 2001
Section 515 of the Treasury and
General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides
for agencies to review most
disseminations of information to the
public under guidelines established by
each agency pursuant to general
guidelines issued by OMB. OMB’s
guidelines were published at 67 FR
8452 (Feb. 22, 2002), and DOE’s
guidelines were published at 67 FR
62446 (Oct. 7, 2002). Pursuant to OMB
Memorandum M–19–15, Improving
Implementation of the Information
Quality Act (April 24, 2019), DOE
published updated guidelines which are
available at www.energy.gov/sites/prod/
files/2019/12/f70/DOE%20Final
%20Updated%20IQA%
20Guidelines%20Dec%202019.pdf.
DOE has reviewed this final rule under
the OMB and DOE guidelines and has
concluded that it is consistent with
applicable policies in those guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ‘‘Actions
Concerning Regulations That
Significantly Affect Energy Supply,
Distribution, or Use,’’ 66 FR 28355 (May
22, 2001), requires Federal agencies to
prepare and submit to OMB, a
Statement of Energy Effects for any
significant energy action. A ‘‘significant
energy action’’ is defined as any action
by an agency that promulgated or is
expected to lead to promulgation of a
final rule, and that (1) is a significant
regulatory action under Executive Order
12866, or any successor order; and (2)
is likely to have a significant adverse
effect on the supply, distribution, or use
of energy; or (3) is designated by the
Administrator of OIRA as a significant
energy action. For any significant energy
action, the agency must give a detailed
statement of any adverse effects on
energy supply, distribution, or use if the
regulation is implemented, and of
reasonable alternatives to the action and
their expected benefits on energy
supply, distribution, and use.
This regulatory action is not a
significant regulatory action under
Executive Order 12866. Moreover, it
would not have a significant adverse
effect on the supply, distribution, or use
of energy, nor has it been designated as
a significant energy action by the
Administrator of OIRA. Therefore, it is
not a significant energy action, and,
accordingly, DOE has not prepared a
Statement of Energy Effects.
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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 modifications to the test
procedure for WSHPs adopted in this
final rule incorporates testing methods
contained in certain sections of the
following commercial standards: AHRI
600–2023, ANSI/ASHRAE 37–2009, ISO
13256–1:1998, and Melinder 2010. DOE
has evaluated these standards and is
unable to conclude whether the
standards 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 has
consulted with both the Attorney
General and the Chairman of the FTC
about the impact on competition of
using the methods contained in these
standards and has received no
comments objecting to their use.
M. Congressional Notification
As required by 5 U.S.C. 801, DOE will
report to Congress on the promulgation
of this rule before its effective date. The
report will state that it has been
determined that the rule is not a ‘‘major
rule’’ as defined by 5 U.S.C. 804(2).
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N. Description of Materials Incorporated
by Reference
In this final rule, DOE incorporates by
reference the following test standards
and reference document:
AHRI 600–2023 is an industry
accepted test procedure for measuring
the performance of water source heat
pumps. AHRI 600–2023 is available on
AHRI’s website at: https://
www.ahrinet.org/search-standards/ahri600-i-p-performance-rating-waterbrineair-heat-pump-equipment.
ANSI/ASHRAE 37–2009 is an
industry-accepted test procedure for
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measuring the performance of
electrically driven unitary airconditioning and heat pump equipment.
ANSI/ASHRAE 37–2009 is available on
ANSI’s website at: webstore.ansi.org/
RecordDetail.aspx?sku=ANSI%2FA
SHRAE+Standard+37-2009.
Errata sheet for ANSI/ASHRAE
Standard 37–2009 dated March 27,
2019, specifies all of the corrections to
ANSI/ASHRAE 37–2009 identified from
the date of publication through March
27, 2019. Errata sheet for ANSI/
ASHRAE Standard 37–2009 is available
on ASHRAE’s website at: https://
www.ashrae.org/technical-resources/
standards-and-guidelines/standardserrata.
Melinder 2010 is a reference booklet
with properties of secondary working
fluids for indirect heating and cooling
systems used in air conditioning, heat
pumps, and other applications.
Melinder 2010 is available from the
International Institute of Refrigeration
website at: www.iifiir.org.
ISO 13256–1:1998 is an industryaccepted test procedure for measuring
the performance of specific water-source
heat pump equipment. ISO 13256–
1:1998 is available on ISO’s website at:
www.iso.org/store.html.
The following standards are currently
approved for the sections in which they
appear in this final rule: AHRI 210/240–
2008 and AHRI 340/360–2007.
V. Approval of the Office of the
Secretary
The Secretary of Energy has approved
publication of this final rule.
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 test
procedures, Incorporation by reference,
Reporting and recordkeeping
requirements.
Signing Authority
This document of the Department of
Energy was signed on November 17,
2023, by Jeffrey Marootian, Principal
Deputy Assistant Secretary for Energy
Efficiency and Renewable Energy,
pursuant to delegated authority from the
Secretary of Energy. That document
Frm 00040
Fmt 4701
Signed in Washington, DC, on November
20, 2023.
Treena V. Garrett,
Federal Register Liaison Officer, U.S.
Department of Energy.
For the reasons stated in the
preamble, DOE amends 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 § 429.4 by:
a. Redesignating paragraphs (c)(4)
through (6) as paragraphs (c)(5) through
(7); and
■ b. Adding new paragraph (c)(4).
The addition reads as follows:
■
■
§ 429.4 Materials incorporated by
reference.
List of Subjects
PO 00000
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.
Sfmt 4700
*
*
*
*
*
(c) * * *
(4) AHRI Standard 600–2023 (I–P)
(‘‘AHRI 600–2023’’), 2023 Standard for
Performance Rating of Water/Brine to
Air Heat Pump Equipment, approved
September 11, 2023; IBR approved for
§ 429.43.
*
*
*
*
*
■ 3. Amend § 429.43 by adding
paragraph (a)(3)(v) to read as follows:
§ 429.43 Commercial heating, ventilating,
air conditioning (HVAC) equipment.
(a) * * *
(3) * * *
(v) Water-Source Heat Pumps. When
certifying to standards in terms of IEER
and ACOP, the following provisions
apply.
(A) Individual model selection:
(1) Representations for a basic model
must be based on the least efficient
individual model(s) distributed in
commerce among all otherwise
comparable model groups comprising
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the basic model, except as provided in
paragraph (a)(3)(v)(A)(2) of this section
for individual models that include
components listed in table 6 to
paragraph (a)(3)(v)(A) of this section.
For the purpose of this paragraph
(a)(3)(v)(A)(1), ‘‘otherwise comparable
model group’’ means a group of
individual models distributed in
commerce within the basic model that
do not differ in components that affect
energy consumption as measured
according to the applicable test
procedure specified at 10 CFR 431.96
other than those listed in table 6 to
paragraph (a)(3)(v)(A) of this section. An
otherwise comparable model group may
include individual models distributed
in commerce with any combination of
the components listed in table 6 (or
none of the components listed in table
6) to paragraph (a)(3)(v)(A) of this
section. An otherwise comparable
model group may consist of only one
individual model.
(2) For a basic model that includes
individual models distributed in
commerce with components listed in
table 6 to paragraph (a)(3)(v)(A) of this
84227
section, the requirements for
determining representations apply only
to the individual model(s) of a specific
otherwise comparable model group
distributed in commerce with the least
number (which could be zero) of
components listed in table 6 to
paragraph (a)(3)(v)(A) of this section
included in individual models of the
group. Testing under this paragraph
shall be consistent with any componentspecific test provisions specified in
section 3 of appendix C1 to subpart F
of 10 CFR part 431.
TABLE 6 TO PARAGRAPH (a)(3)(v)(A)—SPECIFIC COMPONENTS FOR WATER SOURCE HEAT PUMPS
Component
Description
Air Economizers ..............................
An automatic system that enables a cooling system to supply outdoor air to reduce or eliminate the need
for mechanical cooling during mild or cold weather.
Additional components in the water circuit for water control or filtering.
A heat exchanger located downstream of the indoor coil that heats the supply air during cooling operation
using water from the condenser coil in order to increase the ratio of moisture removal to cooling capacity
provided by the equipment.
An assembly that reduces the moisture content of the supply air through moisture transfer with solid or liquid desiccants.
A heat exchanger located downstream of the compressor on the high-pressure vapor line that moves heat
to an external source, such as potable water.
A damper assembly including means to open and close the damper mounted at the supply or return duct
opening of the equipment.
Special grills used to direct airflow in unique applications (such as up and away from a rear wall).
Water is used indirectly or directly to cool ventilation air. In a direct system the water is introduced directly
into the ventilation air and in an indirect system the water is evaporated in secondary air stream and the
heat is removed through a heat exchanger.
The standard indoor fan motor is the motor specified in the manufacturer’s installation instructions for testing and shall be distributed in commerce as part of a particular model. A non-standard high-static motor
is 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.
For a non-standard high-static indoor fan motor(s) to be considered a specific component for a basic
model (and thus subject to the provisions of paragraph (a)(3)(v)(A)(2) of this section), the following 2
provisions must be met:
1. Non-standard high-static indoor fan motor(s) must meet the minimum allowable efficiency determined
per section D.4.1 of AHRI 600–2023 (incorporated by reference, see § 429.4) for non-standard high-static indoor fan motors, or per section D.4.2 of AHRI 600–2023 for non-standard high-static indoor integrated fan and motor combinations.
2. If the standard indoor fan motor can vary fan speed through control system adjustment of motor speed,
all non-standard high-static indoor fan motors must also allow speed control (including with the use of a
variable-frequency drive).
A powered exhaust fan is a fan that transfers directly to the outside a portion of the building air that is returning to the unit, rather than allowing it to recirculate to the indoor coil and back to the building. A powered return fan is a fan that draws building air into the equipment.
A heat exchanger located inside the unit that conditions the equipment’s supply air using energy transferred from an external source using a vapor, gas, or liquid.
A heat exchanger located downstream of the indoor coil that heats the supply air during cooling operation
using high-pressure refrigerant in order to increase the ratio of moisture removal to cooling capacity provided by the equipment.
An assembly of structures through which the supply air passes before leaving the equipment or through
which the return air from the building passes immediately after entering the equipment for which the
sound insertion loss is at least 6 dB for the 125 Hz octave band frequency range.
Coils used to provide supplemental heating.
An assembly that preconditions outdoor 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 heat exchanger located upstream of the indoor coil that conditions the supply air when system water
loop conditions are favorable so as not to utilize compressor operation.
Condenser Pumps/Valves/Fittings ..
Condenser Water Reheat ...............
Desiccant Dehumidification Components.
Desuperheater ................................
Fire/Smoke/Isolation Dampers ........
Grill Options ....................................
Indirect/Direct Evaporative Cooling
of Ventilation Air.
Non-Standard High-Static Indoor
Fan Motors.
Powered Exhaust/Powered Return
Air Fans.
Process Heat Recovery/Reclaim
Coils/Thermal Storage.
Refrigerant Reheat Coils ................
Sound Traps/Sound Attenuators ....
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Steam/Hydronic Heat Coils .............
Ventilation Energy Recovery System (VERS).
Waterside Economizer ....................
(B) The represented value of cooling
capacity must be between 95 percent
and 100 percent of the mean of the
cooling capacities measured for the
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units in the sample selected as
described in paragraph (a)(1)(ii) of this
section, or between 95 percent and 100
percent of the cooling capacity output
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simulated by the AEDM as described in
paragraph (a)(2) of this section.
*
*
*
*
*
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4. Amend § 429.134 by adding
paragraph (dd) to read as follows:
■
§ 429.134 Product-specific enforcement
provisions.
*
*
*
*
*
(dd) Water-Source Heat Pumps. The
following provisions apply for
assessment and enforcement testing of
models subject to standards in terms of
IEER and ACOP.
(1) Verification of Cooling Capacity.
The cooling capacity of each tested unit
of the basic model will be measured
pursuant to the test requirements of
appendix C1 to subpart F of 10 CFR part
431. The mean of the measurements will
be used to determine the applicable
standards for purposes of compliance.
(2) Specific Components. If a basic
model includes individual models with
components listed at table 6 to
§ 429.43(a)(3)(v)(A) and DOE is not able
to obtain an individual model with the
least number (which could be zero) of
those components within an otherwise
comparable model group (as defined in
§ 429.43(a)(3)(v)(A)(1)), DOE may test
any individual model within the
otherwise comparable model group.
PART 431—ENERGY EFFICIENCY
PROGRAM FOR CERTAIN
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
5. The authority citation for part 431
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317; 28 U.S.C.
2461 note.
6. Amend § 431.92 by:
a. Adding in alphabetical order a
definition of ‘‘Applied Coefficient of
performance, or ACOP’’; and
■ b. Revising the definitions of
‘‘Integrated energy efficiency ratio, or
IEER,’’ and ‘‘Water-source heat pump’’.
The addition and revisions read as
follows:
■
■
§ 431.92 Definitions concerning
commercial air conditioners and heat
pumps.
*
*
*
*
*
Applied Coefficient of performance,
or ACOP means the ratio of the heating
capacity to the power input, including
system pump power, for water-source
heat pumps. ACOP is expressed in watts
per watt and determined according to
appendix C1 of this subpart.
*
*
*
*
*
Integrated energy efficiency ratio, or
IEER, means a weighted average
calculation of mechanical cooling EERs
determined for four load levels and
corresponding rating conditions,
expressed in Btu/watt-hour. IEER is
measured:
(1) Per appendix A to this subpart for
air-cooled small (≥65,000 Btu/h), large,
and very large commercial package air
conditioning and heating equipment;
(2) Per appendix C1 to this subpart for
water-source heat pumps;
(3) Per appendix D1 to this subpart for
variable refrigerant flow multi-split air
conditioners and heat pumps (other
than air-cooled with rated cooling
capacity less than 65,000 Btu/h); and
(4) Per appendix G1 to this subpart for
single package vertical air conditioners
and single package vertical heat pumps.
*
*
*
*
*
Water-source heat pump means
commercial package air-conditioning
and heating equipment that is a singlephase or three-phase reverse-cycle heat
pump that uses a circulating water loop
as the heat source for heating and as the
heat sink for cooling. The main
components are a compressor,
refrigerant-to-water heat exchanger,
refrigerant-to-air heat exchanger,
refrigerant expansion devices,
refrigerant reversing valve, and indoor
fan (except that coil-only units do not
include an indoor fan). Such equipment
includes, but is not limited to, water-toair water-loop heat pumps.
■ 7. Amend § 431.95 by:
■ a. Redesignating paragraphs (b)(6)
through (10) as paragraphs (b)(7)
through (11);
■ b. Adding new paragraph (b)(6);
■ c. In paragraph (c)(2), removing the
text ‘‘B, D1’’ and adding, in its place, the
text ‘‘B, C1, D1’’;
d. In paragraph (c)(3), removing the
text ‘‘appendix D1’’ and adding, in its
place, the text ‘‘appendices C1 and D1’’;
■ e. Revising paragraph (d); and
■ f. Adding paragraph (e).
The additions and revision read as
follows:
■
§ 431.95 Materials incorporated by
reference.
*
*
*
*
*
(b) * * *
(6) AHRI Standard 600–2023 (I–P)
(‘‘AHRI 600–2023’’), 2023 Standard for
Performance Rating of Water/Brine to
Air Heat Pump Equipment, AHRIapproved September 11, 2023; IBR
approved for appendix C1 to this
subpart.
*
*
*
*
*
(d) IIR. International Institute of
Refrigeration, 177 Boulevard
Malesherbes 75017 Paris, France; +33
(0)1 42 27 32 35; www.iifiir.org.
(1) Properties of Secondary Working
Fluids for Indirect Systems, including
Section 2.3 Errata Sheet, Melinder,
published 2010 (‘‘Melinder 2010’’), IBR
approved for appendix C1 to this
subpart.
(2) [Reserved]
(e) ISO. International Organization for
Standardization, Chemin de Blandonnet
8, CP 401, 1214 Vernier, Geneva,
Switzerland; +41 22 749 01 11;
www.iso.org/store.html.
(1) ISO Standard 13256–1 (‘‘ISO
13256–1:1998’’), ‘‘Water-source heat
pumps—Testing and rating for
performance—Part 1: Water-to-air and
brine-to-air heat pumps,’’ approved
1998; IBR approved for appendix C to
this subpart.
(2) [Reserved]
*
*
*
*
*
■ 8. Amend § 431.96 by revising table 1
to paragraph (b) to read as follows:
§ 431.96 Uniform test method for the
measurement of energy efficiency of
commercial air conditioners and heat
pumps.
*
*
*
(b) * * *
*
*
TABLE 1 TO PARAGRAPH (b)—TEST PROCEDURES FOR COMMERCIAL AIR CONDITIONERS AND HEAT PUMPS
ddrumheller on DSK120RN23PROD with RULES2
Equipment type
Small Commercial
Package Air-Conditioning and Heating
Equipment.
VerDate Sep<11>2014
Cooling capacity or
moisture removal
capacity 2
Energy efficiency
descriptor
<65,000 Btu/h .............
SEER and HSPF ........
Category
Air-Cooled, 3-Phase,
AC and HP.
19:35 Dec 01, 2023
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Frm 00042
Fmt 4701
Sfmt 4700
Use tests, conditions,
and procedures in
Appendix F to this
subpart 3.
E:\FR\FM\04DER2.SGM
04DER2
Additional test
procedure
provisions as
indicated in the
listed
paragraphs
of this section
None.
Federal Register / Vol. 88, No. 231 / Monday, December 4, 2023 / Rules and Regulations
84229
TABLE 1 TO PARAGRAPH (b)—TEST PROCEDURES FOR COMMERCIAL AIR CONDITIONERS AND HEAT PUMPS—Continued
Equipment type
Cooling capacity or
moisture removal
capacity 2
Category
Energy efficiency
descriptor
SEER2 and HSPF2 ....
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
EER ............................
EER ............................
Large Commercial
Package Air-Conditioning and Heating
Equipment.
IEER and ACOP .........
Air-Cooled AC and HP
≥135,000 Btu/h and
<240,000 Btu/h.
EER, IEER and COP ..
Water-Cooled and
EvaporativelyCooled AC.
Water-Source HP .......
≥135,000 Btu/h and
<240,000 Btu/h.
EER ............................
AHRI 340/360–2007 1
(omit section 6.3).
Paragraphs (c)
and (e).
≥135,000 Btu/h and
<240,000 Btu/h.
≥135,000 Btu/h and
<240,000 Btu/h.
≥240,000 Btu/h and
<760,000 Btu/h.
EER and COP ............
Appendix C to this
subpart 3.
Appendix C1 to this
subpart 3.
Appendix A to this
subpart.
None.
≥240,000 Btu/h and
<760,000 Btu/h.
EER ............................
AHRI 340/360–2007 1
(omit section 6.3).
Paragraphs (c)
and (e).
EER and COP ............
Appendix C to this
subpart 3.
Appendix C1 to this
subpart 3.
Paragraph (g) of this
section.
None.
AC and HP .................
≥240,000 Btu/h and
<760,000 Btu/h.
≥240,000 Btu/h and
<760,000 Btu/h.
<760,000 Btu/h ...........
AC ...............................
<760,000 Btu/h ...........
SCOP ..........................
<760,000 Btu/h or
<930,000 Btu/h 4.
<65,000 Btu/h (3phase).
NSenCOP ...................
Air-Cooled AC and HP
AC ...............................
IEER and ACOP .........
EER, IEER and COP ..
IEER and ACOP .........
EER and COP ............
SEER ..........................
HP ...............................
<65,000 Btu/h (3phase).
SEER and HSPF ........
AC and HP .................
≥65,000 Btu/h and
<760,000 Btu/h.
EER and COP ............
ddrumheller on DSK120RN23PROD with RULES2
IEER and COP ...........
Variable Refrigerant
Flow Multi-split Systems, Water-source.
HP ...............................
<760,000 Btu/h ...........
EER and COP ............
IEER and COP ...........
Single Package Vertical
Air Conditioners and
Single Package
Vertical Heat Pumps.
VerDate Sep<11>2014
Paragraphs (c)
and (e).
None.
<135,000 Btu/h ...........
SEER2 and HSPF2 ....
Variable Refrigerant
Flow Multi-split Systems, Air-cooled.
Paragraphs (c)
and (e).
Water-Source HP .......
SEER2 ........................
Variable Refrigerant
Flow Multi-split Systems, Air-cooled.
None.
EER and COP ............
Water-Source HP .......
Variable Refrigerant
Flow Multi-split Systems.
AHRI 340/360–2007 1
(omit section 6.3).
Appendix C to this
subpart 3.
Appendix C1 to this
subpart 3.
Appendix A to this
subpart.
None.
<135,000 Btu/h ...........
Water-Cooled and
EvaporativelyCooled AC.
Water-Source HP .......
Packaged Terminal Air
Conditioners and
Heat Pumps.
Computer Room Air
Conditioners.
Appendix F1 to this
subpart 3.
Appendix A to this
subpart.
AHRI 210/240–2008 1
(omit section 6.5).
Water-Source HP .......
Water-Source HP .......
Very Large Commercial
Package Air-Conditioning and Heating
Equipment.
Use tests, conditions,
and procedures in
Additional test
procedure
provisions as
indicated in the
listed
paragraphs
of this section
AC and HP .................
19:35 Dec 01, 2023
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<760,000 Btu/h ...........
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EER and COP ............
Sfmt 4700
None.
None.
None.
None.
None.
Paragraphs (c),
(e), and (g).
Appendix E to this
subpart 3.
Appendix E1 to this
subpart 3.
Appendix F to this
subpart 3.
None.
Appendix F1 to this
subpart 3.
Appendix F to this
subpart 3.
None.
Appendix F1 to this
subpart 3.
Appendix D to this
subpart 3.
None.
Appendix D1 to this
subpart 3.
Appendix D to this
subpart 3.
None.
Appendix D1 to this
subpart 3.
Appendix G to this
subpart 3.
None.
E:\FR\FM\04DER2.SGM
04DER2
None.
None.
None.
None.
None.
None.
84230
Federal Register / Vol. 88, No. 231 / Monday, December 4, 2023 / Rules and Regulations
TABLE 1 TO PARAGRAPH (b)—TEST PROCEDURES FOR COMMERCIAL AIR CONDITIONERS AND HEAT PUMPS—Continued
Equipment type
Cooling capacity or
moisture removal
capacity 2
Category
Energy efficiency
descriptor
Use tests, conditions,
and procedures in
EER, IEER, and COP
Direct Expansion-Dedicated Outdoor Air
Systems.
All ................................
<324 lbs. of moisture
removal/hr.
ISMRE2 and ISCOP2
Appendix G1 to this
subpart 3.
Appendix B to this
subpart.
Additional test
procedure
provisions as
indicated in the
listed
paragraphs
of this section
None.
None.
1 Incorporated
by reference; see § 431.95.
removal capacity applies only to direct expansion-dedicated outdoor air systems.
3 For equipment with multiple appendices listed in this Table 1, consult the notes at the beginning of those appendices to determine the applicable appendix to use for testing.
4 For upflow ducted and downflow floor-mounted computer room air conditioners, the test procedure in appendix E1 of this subpart applies to
equipment with net sensible cooling capacity less than 930,000 Btu/h. For all other configurations of computer room air conditioners, the test procedure in appendix E1 applies to equipment with net sensible cooling capacity less than 760,000 Btu/h.
2 Moisture
*
*
*
*
*
9. Add appendix C to subpart F of part
431 to read as follows:
■
ddrumheller on DSK120RN23PROD with RULES2
Appendix C to Subpart F of Part 431—
Uniform Test Method for Measuring the
Energy Consumption of Water-Source
Heat Pumps
Note: Manufacturers must use the results of
testing under this appendix to determine
compliance with the relevant standard at
§ 431.97 as that standard appeared in the
January 1, 2023 edition of 10 CFR parts 200–
499. Specifically, representations must be
based on testing according to either this
appendix or 10 CFR 431.96 as it appeared in
the 10 CFR parts 200–499 edition revised as
of January 1, 2023.
Starting on November 29, 2024, voluntary
representations with respect to energy use or
efficiency of water-source heat pumps with
cooling capacity greater than or equal to
135,000 Btu/h and less than 760,000 Btu/h
must be based on testing according to this
appendix. Manufacturers may also use this
appendix to make voluntary representations
with respect to energy use or efficiency prior
to November 29, 2024.
Starting on November 29, 2024, voluntary
representations with respect to the integrated
energy efficiency ratio (IEER) and applied
coefficient of performance (ACOP) of watersource heat pumps must be based on testing
according to appendix C1 of this subpart.
Manufacturers may also use appendix C1 to
make voluntary representations with respect
to IEER and ACOP prior to November 29,
2024.
Starting on the compliance date for any
amended energy conservation standards for
water-source heat pumps based on IEER and
ACOP, any representations, including
compliance certifications, made with respect
to the energy use or energy efficiency of
water-source heat pumps must be based on
testing according to appendix C1 of this
subpart.
Manufacturers may also certify compliance
with any amended energy conservation
standards for water-source heat pumps based
on IEER and ACOP prior to the applicable
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19:35 Dec 01, 2023
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compliance date for those standards, and
those compliance certifications must be
based on testing according to appendix C1 of
this subpart.
1. Incorporation by Reference
DOE incorporated by reference in
§ 431.95, the entire standard for ISO
13256–1:1998. To the extent there is a
conflict between the terms or provisions
of a referenced industry standard and
this appendix, the appendix provisions
control.
2. General
Determine the energy efficiency ratio
(EER) and coefficient of performance
(COP) in accordance with ISO 13256–
1:1998.
Section 3 of this appendix provides
additional instructions for determining
EER and COP.
3. Additional Provisions for Equipment
Set-Up
The only additional specifications
that may be used in setting up the basic
model for testing are those set forth in
the installation and operation manual
shipped with the unit. Each unit should
be set up for test in accordance with the
manufacturer installation and operation
manuals. Sections 3.1 through 3.2 of
this appendix provide specifications for
addressing key information typically
found in the installation and operation
manuals.
3.1. If a manufacturer specifies a range
of superheat, sub-cooling, and/or
refrigerant pressure in its installation
and operation manual for a given basic
model, any value(s) within that range
may be used to determine refrigerant
charge or mass of refrigerant, unless the
manufacturer clearly specifies a rating
value in its installation and operation
manual, in which case the specified
rating value must be used.
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3.2. The airflow rate used for testing
must be that set forth in the installation
and operation manuals being shipped to
the commercial customer with the basic
model and clearly identified as that
used to generate the DOE performance
ratings. If a rated airflow value for
testing is not clearly identified, a value
of 400 standard cubic feet per minute
(scfm) per ton must be used.
10. Add appendix C1 to subpart F of
part 431 to read as follows:
■
Appendix C1 to Subpart F of Part 431—
Uniform Test Method for Measuring the
Energy Consumption of Water-Source
Heat Pumps
Note: Prior to the compliance date of
amended standards for water-source heat
pumps that rely on integrated energy
efficiency ratio (IEER) and applied coefficient
of performance (ACOP) published after
January 1, 2023, representations with respect
to the energy use or energy efficiency of
water-source heat pumps, including
compliance certifications, must be based on
testing according to appendix C of this
subpart.
Starting on November 29, 2024, voluntary
representations with respect to the IEER and
ACOP of water-source heat pumps must be
based on testing according to this appendix.
Manufacturers may also use this appendix to
make voluntary representations with respect
to IEER and ACOP prior to November 29,
2024.
Starting on the compliance date for any
amended energy conservation standards for
water-source heat pumps based on IEER and
ACOP, any representations, including
compliance certifications, made with respect
to the energy use or energy efficiency of
water-source heat pumps must be based on
testing according to this appendix.
Manufacturers may also certify compliance
with any amended energy conservation
standards for water-source heat pumps based
on IEER and ACOP prior to the applicable
compliance date for those standards, and
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Federal Register / Vol. 88, No. 231 / Monday, December 4, 2023 / Rules and Regulations
those compliance certifications must be
based on testing according to this appendix.
1. Incorporation by Reference
DOE incorporated by reference in
§ 431.95 the entire standards for AHRI
600–2023, ANSI/ASHRAE 37–2009 (as
corrected by the Errata sheet for ANSI/
ASHRAE 37–2009), and Melinder 2010.
However, certain enumerated provisions
of AHRI 600–2023 and ASHRAE 37–
2009, as listed in this section 1, are
inapplicable.
To the extent there is a conflict
between the terms or provisions of a
referenced industry standard and the
CFR, the CFR provisions control.
1.1. AHRI 600–2023
(a) Section 1 Purpose is inapplicable,
(b) Section 2 Scope is inapplicable,
(c) The following subsections of
section 3 Definitions are inapplicable:
(1) 3.2.1 (Air Economizer),
(2) 3.2.3 (Barometric Relief Dampers),
(3) 3.2.4 (Basic Model),
(4) 3.2.5 (Coated Coils),
(5) 3.2.6 (Coefficients of Performance),
(6) 3.2.9 (Condenser Pump/Valves/
Fittings),
(7) 3.2.10 (Condenser Water Reheat),
(8) 3.2.13 (Desiccant
Dehumidification Components),
(9) 3.2.14 (Desuperheater),
(10) 3.2.15.1 (Energy Efficiency Ratio),
(11) 3.2.16 (Evaporative Cooling of
Ventilation Air),
(12) 3.2.17 (Fire/Smoke/Isolation
Dampers),
(13) 3.2.19 (Fresh Air Dampers),
(14) 3.2.21 (Grill Options),
(15) 3.2.23 (High-effectiveness Indoor
Air Filtration),
(16) 3.2.24 (Hot Gas Bypass),
(17) 3.2.27 (Integrated Energy
Efficiency Ratio),
(18) 3.2.28 (Low-static Heat Pump),
(19) 3.2.35 (Power Correction
Capacitors),
(20) 3.2.36 (Powered Exhaust Air
Fan),
(21) 3.2.37 (Powered Return Air Fan),
(22) 3.2.38 (Process Heat Recovery/
Reclaim Coils/Thermal Storage),
(23) 3.2.40 (Published Rating),
(24) 3.2.42 (Refrigerant Reheat Coils),
(25) 3.2.43 (Single Package Heat
Pumps),
(26) 3.2.44 (Sound Traps/Sound
Attenuators),
(27) 3.2.45 (Split System Heat Pump),
(28) 3.2.51 (Steam/Hydronic Heat
Coils),
(29) 3.2.53 (UV Lights),
(30) 3.2.54 (Ventilation Energy
Recovery System),
(31) 3.2.55 (Water/Brine to Air Heat
Pump Equipment), and
(32) 3.2.56 (Waterside Economizer),
(d) The following subsections of
section 6 Rating Requirements are
inapplicable:
(1) 6.5 (Residential Cooling Capacity
and Efficiency),
(2) 6.6 (Residential Heating Capacity
and Efficiency),
(3) 6.7 (Test Data vs Computer
Simulation),
(4) 6.8 (Rounding and Precision),
(5) 6.9 (Uncertainty), and
(6) 6.10 (Verification Testing),
(e) Section 7 Minimum Data
Requirements for Published Ratings is
inapplicable
(f) Section 8 Operating Requirements
is inapplicable,
(g) Section 9 Marking and Nameplate
Data is inapplicable,
(h) Section 10 Conformance
Conditions is inapplicable,
(i) Appendix B References—
Informative is inapplicable,
(j) Sections D.1 (Purpose), D.2
(Configuration Requirements), and D.3
(Optional System Features) of Appendix
D Unit Configuration For Standard
Efficiency Determination—Normative
are inapplicable, and
84231
(k) Appendix F Example of
Determination of Fan and Motor
Efficiency for Non-standard Integrated
Indoor Fan and Motors—Informative is
inapplicable.
1.2. ANSI/ASHRAE 37–2009 (Even if
Corrected by the Errata Sheet)
(a) Section 1 Purpose is inapplicable.
(b) Section 2 Scope is inapplicable.
(c) Section 4 Classification is
inapplicable.
2. General
Determine integrated energy
efficiency ratio (IEER) and heating
applied coefficient of performance
(ACOP) in accordance with this
appendix and the applicable sections of
AHRI 600–2023, ANSI/ASHRAE 37–
2009, and Melinder 2010.
Representations of AEER, EER, and COP
may optionally be made.
Section 3 of this appendix provides
additional instructions for testing. In
cases where there is a conflict, the
language of this appendix takes highest
precedence, followed by AHRI 600–
2023, followed by ANSI/ASHRAE 37–
2009. Any subsequent amendment to a
referenced document by the standardsetting organization will not affect the
test procedure in this appendix, unless
and until the test procedure is amended
by DOE. Material is incorporated as it
exists on the date of the approval, and
a notification of any change in the
incorporation must be published in the
Federal Register.
3. Setup and Test Provisions for Specific
Components
When testing a water-source heat
pump that includes any of the features
listed in table 1 to this appendix, test in
accordance with the setup and test
provisions specified in table 1 to this
appendix.
ddrumheller on DSK120RN23PROD with RULES2
TABLE 1 TO APPENDIX C1—SETUP AND TEST PROVISIONS FOR SPECIFIC COMPONENTS
Component
Description
Setup and test provisions
Air Economizers ...................
An automatic system that enables a cooling system to
supply outdoor air to reduce or eliminate the need for
mechanical cooling during mild or cold weather.
Barometric Relief Dampers ..
An assembly with dampers and means to automatically
set the damper position in a closed position and one
or more open positions to allow venting directly to the
outside a portion of the building air that is returning
to the unit, rather than allowing it to recirculate to the
indoor coil and back to the building.
An assembly that reduces the moisture content of the
supply air through moisture transfer with solid or liquid desiccants.
For any air economizer that is factory-installed, place
the economizer in the 100 percent return position
and close and seal the outside air dampers for testing. For any modular air economizer shipped with the
unit but not factory-installed, do not install the economizer for testing.
For any barometric relief dampers that are factory-installed, close and seal the dampers for testing. For
any modular barometric relief dampers shipped with
the unit but not factory-installed, do not install the
dampers for testing.
Desiccant Dehumidification
Components.
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Disable desiccant dehumidification components for testing.
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84232
Federal Register / Vol. 88, No. 231 / Monday, December 4, 2023 / Rules and Regulations
TABLE 1 TO APPENDIX C1—SETUP AND TEST PROVISIONS FOR SPECIFIC COMPONENTS—Continued
Component
Description
Setup and test provisions
Fire/Smoke/Isolation
Dampers.
A damper assembly including means to open and close
the damper mounted at the supply or return duct
opening of the equipment.
Fresh Air Dampers ...............
An assembly with dampers and means to set the
damper position in a closed and one open position to
allow air to be drawn into the equipment when the indoor fan is operating.
Power Correction Capacitors
A capacitor that increases the power factor measured
at the line connection to the equipment.
A heat exchanger located inside the unit that conditions
the equipment’s supply air using energy transferred
from an external source using a vapor, gas, or liquid.
A heat exchanger located downstream of the indoor
coil that heats the supply air during cooling operation
using high-pressure refrigerant in order to increase
the ratio of moisture removal to cooling capacity provided by the equipment.
Coils used to provide supplemental heating ...................
For any fire/smoke/isolation dampers that are factoryinstalled, set the dampers in the fully open position
for testing. For any modular fire/smoke/isolation
dampers shipped with the unit but not factory-installed, do not install the dampers for testing.
For any fresh air dampers that are factory-installed,
close and seal the dampers for testing. For any modular fresh air dampers shipped with the unit but not
factory-installed, do not install the dampers for testing.
Remove power correction capacitors for testing.
Process Heat recovery/Reclaim Coils/Thermal Storage.
Refrigerant Reheat Coils .....
Steam/Hydronic Heat Coils ..
UV Lights .............................
Ventilation Energy Recovery
System (VERS).
A lighting fixture and lamp mounted so that it shines
light on the indoor coil, that emits ultraviolet light to
inhibit growth of organisms on the indoor coil surfaces, the condensate drip pan, and/other locations
within the equipment.
An assembly that preconditions outdoor 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.
Disconnect the heat exchanger from its heat source for
testing.
De-activate refrigerant reheat coils for testing so as to
provide the minimum (none if possible) reheat
achievable by the system controls.
Test with steam/hydronic heat coils in place but providing no heat.
Turn off UV lights for testing.
For any VERS that is factory-installed, place the VERS
in the 100 percent return position and close and seal
the outside air dampers and exhaust air dampers for
testing, and do not energize any VERS subcomponents (e.g., energy recovery wheel motors). For any
VERS module shipped with the unit but not factoryinstalled, do not install the VERS for testing.
[FR Doc. 2023–25921 Filed 12–1–23; 8:45 am]
ddrumheller on DSK120RN23PROD with RULES2
BILLING CODE 6450–01–P
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]]>Agencies
[Federal Register Volume 88, Number 231 (Monday, December 4, 2023)]
[Rules and Regulations]
[Pages 84188-84232]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-25921]
[[Page 84187]]
Vol. 88
Monday,
No. 231
December 4, 2023
Part II
Department of Energy
-----------------------------------------------------------------------
10 CFR Parts 429 and 431
Energy Conservation Program: Test Procedure for Water-Source Heat
Pumps; Final Rule
Federal Register / Vol. 88 , No. 231 / Monday, December 4, 2023 /
Rules and Regulations
[[Page 84188]]
-----------------------------------------------------------------------
DEPARTMENT OF ENERGY
10 CFR Parts 429 and 431
[EERE-2017-BT-TP-0029]
RIN 1904-AE05
Energy Conservation Program: Test Procedure for Water-Source Heat
Pumps
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The U.S. Department of Energy (``DOE'') is amending its test
procedure for water-source heat pumps to expand the scope of
applicability of the test procedure, incorporate by reference a new
industry consensus test standard for water-source heat pumps, adopt a
seasonal cooling efficiency metric, and specify more representative
test conditions used for measuring heating performance. DOE has
determined that the amended test procedure will produce results that
are more representative of an average use cycle and be more consistent
with current industry practice without being unduly burdensome to
conduct. Additionally, DOE is adopting provisions governing public
representations of efficiency for this equipment.
DATES: The effective date of this rule is January 3, 2024. The
amendments will be mandatory for product testing starting November 29,
2024.
The incorporation by reference of certain material listed in the
rule is approved by the Director of the Federal Register on January 3,
2024.
ADDRESSES: The docket, which includes Federal Register notices, public
meeting attendee lists and transcripts, comments, and other supporting
documents/materials, is available for review at www.regulations.gov.
All documents in the docket are listed in the www.regulations.gov
index. However, not all documents listed in the index may be publicly
available, such as those containing information that is exempt from
public disclosure.
A link to the docket web page can be found at www.regulations.gov/docket/EERE-2017-BT-TP-0029. The docket web page contains instructions
on how to access all documents, including public comments, in the
docket.
For further information on how to review the docket contact the
Appliance and Equipment Standards Program staff at (202) 287-1445 or by
email: [email protected].
FOR FURTHER INFORMATION CONTACT:
Mr. Troy Watson, 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:
(240) 449-9387. Email: [email protected].
Ms. Kristin Koernig, U.S. Department of Energy, Office of the
General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC
20585-0121. Telephone: (202) 586-3593. Email:
[email protected].
SUPPLEMENTARY INFORMATION: DOE incorporates by reference the following
material into 10 CFR parts 429 and 431:
AHRI Standard 600-2023 (I-P), 2023 Standard for Performance Rating of
Water/Brine to Air Heat Pump Equipment, approved September 11, 2023
(``AHRI 600-2023'').
ANSI/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 37-2009'').
Errata sheet for ANSI/ASHRAE Standard 37-2009, Methods of Testing for
Rating Electrically Driven Unitary Air-Conditioning and Heat Pump
Equipment, March 27, 2019.
ISO Standard 13256-1:1998, Water-source heat pumps--Testing and rating
for performance--Part 1: Water-to-air and brine-to-air heat pumps,
approved 1998 (``ISO 13256-1:1998'').
Properties of Secondary Working Fluids for Indirect Systems, including
Section 2.3 Errata Sheet, Melinder, published 2010 (``Melinder 2010'').
Copies of AHRI 600-2023 are available from the Air-Conditioning,
Heating, and Refrigeration Institute (``AHRI''), 2311 Wilson Blvd.,
Suite 400, Arlington, VA 22201, (703) 524-8800, or by going to
www.ahrinet.org.
Copies of ANSI/ASHRAE 37-2009 and Errata sheet for ANSI/ASHRAE
Standard 37-2009 are available from the American Society of Heating,
Refrigerating, and Air-Conditioning Engineers (``ASHRAE''), 180
Technology Parkway NW, Peachtree Corners, GA 30092, (404) 636-8400, or
by going to www.ashrae.org. (ASHRAE standards are co-published with
American National Standards Institute (``ANSI'')).
Copies of ISO Standard 13256-1:1998 can be obtained from the
International Organization for Standardization (``ISO''), Chemin de
Blandonnet 8 CP 401, 1214 Vernier, Geneva, Switzerland, +41 22 749 01
11, or online at: www.iso.org/store.html.
Copies of Melinder 2010 are available from the International
Institute of Refrigeration (``IIR''), 177 Boulevard Malesherbes 75017
Paris, France; +33 (0)1 42 27 32 35; www.iifiir.org.
See section IV.N of this document for further discussion of these
standards.
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope of Applicability
1. WSHPs With Cooling Capacity Greater Than or Equal to 135,000
Btu/h
2. Representations for Residential Applications
B. Definition
C. Organization of the Amended DOE Test Procedures
D. Updates to Industry Standards
1. Comments Regarding DOE's Authority
2. Comments Regarding DOE's Test Procedure Development Process
3. Comments Supporting the Adoption of AHRI 340/360-2022
4. Comments Opposing the Adoption of AHRI 340/360-2022
5. Comments Encouraging the Adoption of AHRI 600
6. Finalized DOE Test Procedure
E. Efficiency Metrics
1. IEER
2. ACOP
3. Optional Representations
4. Entering Air Conditions
F. Test Method
1. Airflow and External Static Pressure
2. Capacity Measurement
3. Pump Power Adjustment and Liquid External Static Pressure
4. Test Liquid and Specific Heat Capacity
5. Liquid Flow Rate
6. Refrigerant Line Losses
7. Airflow Measurement
8. Air Condition Measurement
9. Duct Losses
10. Refrigerant Charging
11. Voltage
12. Non-Standard Low-Static Indoor Fan Motors
G. Configuration of Unit Under Test
1. Background and Summary
2. General Comments Received
3. Approach for Exclusion of Certain Components
H. Represented Values and Enforcement
1. Cooling Capacity
2. Enforcement of IEER
I. Test Procedure Costs
J. Effective and Compliance Dates
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866, 13563, and 14094
B. Review Under the Regulatory Flexibility Act
1. Description and Estimate of Small Entities Regulated
2. Description and Estimate of Compliance Requirements
[[Page 84189]]
3. Certification Statement
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
M. Congressional Notification
N. Description of Materials Incorporated by Reference
V. Approval of the Office of the Secretary
I. Authority and Background
Water-source heat pumps (``WSHPs'') are a category of small, large,
and very large commercial package air-conditioning and heating
equipment,\1\ which 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);
6313(a)(1)(G)-(I)) DOE's test procedure for WSHPs is currently
prescribed at title 10 of the Code of Federal Regulations (``CFR'')
part 431.96. The following sections discuss DOE's authority to
establish and amend a test procedure for WSHPs and relevant background
information regarding DOE's consideration of a test procedure for this
equipment.
---------------------------------------------------------------------------
\1\ The Energy Policy and Conservation Act, as amended
(``EPCA'') defines ``commercial package air conditioning and heating
equipment'' as 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)) EPCA further 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); ``large commercial package air
conditioning and heating equipment'' as commercial package air
conditioning and heating equipment that is rated at or above 135,000
Btu per hour and below 240,000 Btu per hour (cooling capacity); and
``very large commercial package air conditioning and heating
equipment'' as commercial package air conditioning and heating
equipment that is rated at or above 240,000 Btu per hour and below
760,000 Btu per hour (cooling capacity). (42 U.S.C. 6311(8)(B)-(D))
---------------------------------------------------------------------------
A. Authority
The Energy Policy and Conservation Act, Public Law 94-163, as
amended (``EPCA''),\2\ authorizes DOE to regulate the energy efficiency
of a number of consumer products and certain industrial equipment. (42
U.S.C. 6291-6317) Title III, Part C of EPCA,\3\ added by Public Law 95-
619, Title IV, section 441(a), established the Energy Conservation
Program for Certain Industrial Equipment, which sets forth a variety of
provisions designed to improve energy efficiency. This equipment
includes WSHPs, the subject of this document. (42 U.S.C. 6311(1)(B)-
(D))
---------------------------------------------------------------------------
\2\ All references to EPCA in this document refer to the statute
as amended through the Energy Act of 2020, Public Law 116-260 (Dec.
27, 2020), which reflect the last statutory amendments that impact
Parts A and A-1 of EPCA.
\3\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
The energy conservation program under EPCA consists essentially of
four parts: (1) testing, (2) labeling, (3) Federal energy conservation
standards, and (4) certification and enforcement procedures. Relevant
provisions of EPCA include definitions (42 U.S.C. 6311), test
procedures (42 U.S.C. 6314), labeling provisions (42 U.S.C. 6315),
energy conservation standards (42 U.S.C. 6313), and the authority to
require information and reports from manufacturers (42 U.S.C. 6316; 42
U.S.C. 6296).
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 other 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 42 U.S.C. 6316(b); 42 U.S.C. 6297) DOE may, however,
grant waivers of Federal preemption for particular State laws or
regulations, in accordance with the procedures and other provisions of
EPCA. (42 U.S.C. 6316(b)(2)(D))
Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered equipment. EPCA requires that any test procedures prescribed or
amended under this section must be reasonably designed to produce test
results which reflect energy efficiency, energy use or estimated annual
operating cost of a given type of covered equipment during a
representative average use cycle (as determined by the Secretary) and
requires that test procedures not be unduly burdensome to conduct. (42
U.S.C. 6314(a)(2))
EPCA 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 90.1, ``Energy Standard
for Buildings Except Low-Rise Residential Buildings'' (``ASHRAE
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 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 7 years, DOE evaluate
test procedures for each type of covered equipment, including WSHPs, to
determine whether amended test procedures would more accurately or
fully comply with the requirements for the test procedures to not be
unduly burdensome to conduct and be reasonably designed to produce test
results that reflect energy efficiency, energy use, and estimated
operating costs during a representative average use cycle. (42 U.S.C.
6314(a)(1)
In addition, if the Secretary determines that a test procedure
amendment is warranted, the Secretary must publish proposed test
procedures in the Federal Register and afford interested persons an
opportunity (of not less than 45 days' duration) to present oral and
written data, views, and arguments on the proposed test procedures. (42
U.S.C. 6314(b)) If DOE determines that test procedure revisions are not
appropriate, DOE must publish in the Federal Register its determination
not to amend the test procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
DOE undertook this rulemaking in satisfaction of the 7-year-
lookback obligations under EPCA. (42 U.S.C. 6314(a)(1)). As discussed
previously in this document, WSHPs are a category of commercial package
air conditioning and heating equipment. EPCA requires the DOE test
procedures for commercial package air conditioning and heating
[[Page 84190]]
equipment to be the generally accepted industry testing procedure
developed or recognized by AHRI or by ASHRAE, as referenced in ASHRAE
90.1. (42 U.S.C. 6314(a)(4)(A)) EPCA further requires that each time
the referenced industry test procedure is amended in ASHRAE 90.1, DOE
must amend its test procedure to be consistent with the industry
update, unless DOE determines in a rulemaking that there is clear and
convincing evidence that the updated update industry test procedure
would not be representative of an average use cycle or would be unduly
burdensome to conduct. (42 U.S.C. 6314(a)(4)(B)(C)) However, under the
7-year-lookback obligations, there is no ``clear and convincing
evidence'' required in EPCA. Rather, EPCA only requires that DOE
determine whether the amended test procedure would more accurately or
fully comply with the requirements for the test procedure to not be
unduly burdensome to conduct and be reasonably designed to produce test
results that reflect energy efficiency, energy use, and estimated
operating costs during a representative average use cycle. (42 U.S.C.
6314(a)(1))
DOE is publishing this final rule in satisfaction of its statutory
obligations under EPCA. (42 U.S.C. 6314(a)(1)(A))
B. Background
DOE's existing test procedure for WSHPs is specified at 10 CFR
431.96 (``Uniform test method for the measurement of energy efficiency
of commercial air conditioners and heat pumps''). The Federal test
procedure currently incorporates by reference International
Organization for Standardization (``ISO'') Standard 13256-1 (1998),
``Water-source heat pumps--Testing and rating for performance--Part 1:
Water-to-air and brine-to-air heat pumps,'' (``ISO 13256-1:1998'').
DOE initially incorporated ISO 13256-1:1998 as the referenced test
procedure for WSHPs on October 21, 2004 (69 FR 61962), and DOE last
reviewed the test procedure for WSHPs as part of a final rule for
commercial package air conditioners and heat pumps published in the
Federal Register on May 16, 2012 (``May 2012 Final Rule''; 77 FR
28928). In the May 2012 Final Rule, DOE retained the reference to ISO
13256-1:1998 but adopted additional provisions for equipment setup at
10 CFR 431.96(e), which provide specifications for addressing key
information typically found in the installation and operation manuals.
77 FR 28928, 28991.
On June 22, 2018, DOE published a request for information (``RFI'')
to collect information and data to consider amendments to DOE's test
procedure for WSHPs (``June 2018 RFI''). 83 FR 29048.\4\ Subsequently,
on August 30, 2022, DOE published a notice of proposed rulemaking
(``NOPR'') in which DOE responded to stakeholders' comments on the June
2018 RFI and proposed amendments to its test procedure for WSHPs
(``August 2022 NOPR'') 87 FR 53302. In the August 2022 NOPR, DOE
proposed to amend the test procedures for WSHPs to incorporate by
reference AHRI Standard 340/360-2022 (I-P), ``2022 Standard for
Performance Rating of Commercial and Industrial Unitary Air-
conditioning and Heat Pump Equipment'' (``AHRI 340/360-2022'') and
ANSI/ASHRAE Standard 37-2009, ``Methods of Testing for Rating
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment''
(``ANSI/ASHRAE 37-2009''). Id. at 87 FR 53348. Specifically, DOE
proposed to implement these changes by adding new appendices C and C1
to subpart F of part 431, both titled ``Uniform Test Method for
Measuring the Energy Consumption of Water-Source Heat Pumps.''
(``appendix C'' and ``appendix C1,'' respectively). Id. at 87 FR 53351-
52252. The current DOE test procedure for WSHPs would be relocated to
appendix C without change, and the new test procedure adopting AHRI
340/360-2022 and ANSI/ASHRAE 37-2009 and any other amendments would be
set forth in proposed appendix C1 for determining IEER. Id. at 87 FR
53352-53353. DOE held a public meeting on September 14, 2022 (``NOPR
public meeting'') to present the key proposals from the August 2022
NOPR.
---------------------------------------------------------------------------
\4\ An extension of the comment period for the June 2018 RFI was
published July 9, 2018. 83 FR 31704.
---------------------------------------------------------------------------
DOE received comments in response to the August 2022 NOPR from the
interested parties listed in Table I.1.
Table I.1--List of Commenters With Written Submissions in Response to the August 2022 NOPR
----------------------------------------------------------------------------------------------------------------
Reference in this final Comment No. in
Commenter(s) rule the docket Commenter type
----------------------------------------------------------------------------------------------------------------
Air-Conditioning, Heating and AHRI..................... 24 Trade Association.
Refrigeration Institute.
Appliance Standards Awareness Project, Joint Commenters......... 27 Efficiency Organizations.
American Council for an Energy-
Efficient Economy.
Northwest Energy Efficiency Alliance... NEEA..................... 25 Efficiency Organization.
New York State Energy Research and NYSERDA.................. 21 State Agency.
Development Authority.
ClimateMaster, Inc..................... ClimateMaster............ 22 Manufacturer.
WaterFurnace International............. WaterFurnace............. 20 Manufacturer.
Enertech Global, LLC................... Enertech................. 19 Manufacturer.
Florida Heat Pump Manufacturing........ FHP...................... 26 Manufacturer.
The Geothermal Exchange Organization... GeoExchange.............. 29 Trade Association.
Madison Indoor Air Quality............. MIAQ..................... 23 Manufacturer.
Trane Technologies..................... Trane.................... 28 Manufacturer.
----------------------------------------------------------------------------------------------------------------
A parenthetical reference at the end of a comment quotation or
paraphrase provides the location of the item in the public record.\5\
In addition to the comments listed in Table I.1, DOE also received 2
comments from anonymous individuals, which were considered in the
development of this final rule, but not cited individually. To the
extent that interested parties have provided written comments that are
substantively consistent with any oral comments provided during the
NOPR public meeting, DOE cites the written comments throughout this
final rule.
[[Page 84191]]
Any oral comments provided during the webinar that are not
substantively addressed by written comments are summarized and cited
separately throughout this final rule.
---------------------------------------------------------------------------
\5\ The parenthetical reference provides a reference for
information located in the docket of DOE's rulemaking to develop an
amended test procedure for WSHPs. (Docket No. EERE-2017-BT-TP-0029,
which is maintained at www.regulations.gov). The references are
arranged as follows: (commenter name, comment docket ID number, page
of that document).
---------------------------------------------------------------------------
In May 2021, ISO published an updated version of Standard 13256-1,
ISO Standard 13256-1 (2021), ``Water-source heat pumps--Testing and
rating for performance--Part 1: Water-to-air and brine-to-air heat
pumps,'' (``ISO 13256-1:2021''). In January 2023, ASHRAE published
ASHRAE 90.1-2022. ASHRAE 90.1-2022 did not update the referenced test
procedure for WSHPs.\6\
---------------------------------------------------------------------------
\6\ ASHRAE 90.1-2022 lists ANSI/AHRI/ASHRAE 13256-1: 1998 (2021)
as the test procedure for WSHPs. However, DOE believes ASHRAE
intended to include ``2012'' in the parentheses as that was the most
recent year in which the 1998 version of 13256-1 was redesignated.
---------------------------------------------------------------------------
On September 11, 2023, AHRI published a new industry test standard
for WSHPs, titled AHRI Standard 600, ``Standard for Performance Rating
of Water/Brine to Air Heat Pump Equipment'' (``AHRI 600-2023''). DOE
worked with stakeholders (including WSHP manufacturers and efficiency
advocates) as part of the AHRI Geothermal and WSHP standards technical
committee (``STC'') to develop AHRI 600-2023, which addresses many of
the issues in the current WSHP test procedure that DOE raised in the
August 2022 NOPR. The intent of the Geothermal and WSHP STC was for
AHRI 600-2023 to be used for testing WSHPs instead of any versions of
ISO Standards 13256-1.
II. Synopsis of the Final Rule
In this final rule DOE is establishing new appendices C and C1 to
subpart F of part 431. The current DOE test procedure for WSHPs is
relocated to appendix C without change. The amended test procedure for
WSHPs is established in a new appendix C1, which includes the following
amended test procedure requirements for WSHPs for measuring the updated
efficiency metrics: (1) integrated energy efficiency ratio (``IEER'')
for WSHPs using AHRI 600-2023; and (2) applied coefficient of
performance (``ACOP'') using AHRI 600-2023. Use of the amended test
procedure in appendix C1 will not be required until such time as
compliance is required with amended energy conservation standards for
WSHPs denominated in terms of IEER, should DOE adopt such standards.
Additionally, DOE is expanding the scope of the test procedure to
include WSHPs with capacities between 135,000 and 760,000 British
thermal units per hour (``Btu/h''), as well as specifying the
components that must be present for testing and amending certain
provisions related to representations and enforcement in 10 CFR part
429.
As discussed in this final rule, DOE has concluded that the amended
test procedure in appendix C1 (incorporating by reference the most
recent industry consensus test standard for WSHPs, AHRI 600-2023)
provides more representative results and more fully complies with the
requirements of 42 U.S.C. 6314(a)(2) than testing with the current
Federal test procedure (based on ISO 13256-1:1998).
The adopted amendments are summarized in Table II.1 and compared to
the test procedure provisions in place prior to the amendment, as well
as the reason for the adopted change.
Table II.1--Summary of Changes in the Amended Test Procedure
------------------------------------------------------------------------
Amended test
Current DOE test procedure procedure Attribution
------------------------------------------------------------------------
Located in 10 CFR 431.96........ Current test Readability of
procedure moved test procedure.
to appendix C to
10 CFR 431.96 and
amended test
procedure
established in
appendix C1 to 10
CFR 431.96.
Scope is limited to units with a Expands the scope Harmonize with
cooling capacity less than of the test scope of test
135,000 Btu/h. procedure to procedure for
additionally water-cooled
include units commercial
with a cooling unitary air
capacity greater conditioners.
than or equal to
135,000 Btu/h and
less than 760,000
Btu/h in 10 CFR
431.96.
Incorporates by reference ISO Incorporates by Improve
13256-1:1998. reference AHRI representativenes
600-2023 into s of test
appendix C1. procedure.
Includes provisions for Includes Improve
determining EER metric. provisions for representativenes
determining IEER s of test
by incorporating procedure.
by reference AHRI
600-2023 into
appendix C1.
Specifies test condition of 68 Changes the test Improve
[deg]F for measuring condition for representativenes
coefficient of performance ACOP to 50 s of test
(``COP''). [deg]F, by procedure.
incorporating by
reference AHRI
600-2023 into
appendix C1.
Does not include WSHP-specific Includes Establish WSHP-
provisions for determination of provisions in 10 specific
represented values in 10 CFR CFR 429.43 provisions for
429.43. specific to WSHPs determination of
for determining represented
represented values.
values.
Does not include WSHP-specific Adopts product- Establish
enforcement provisions in 10 specific enforcement
CFR 429.134. enforcement provisions for
provisions for DOE testing of
WSHPs regarding WSHPs.
verification of
cooling capacity,
testing of
systems with
specific
components, and
IEER testing
conducted by DOE.
------------------------------------------------------------------------
DOE has determined that the test procedure in appendix C, as
described in section III of this final rule regarding the establishment
of appendix C, does not alter the measured efficiency of WSHPs or
require retesting solely as a result of the establishment of appendix
C. Additionally, DOE has determined that the establishment of appendix
C will not increase the cost of testing.
DOE has determined that the amended test procedure adopted in
appendix C1 does alter the measured efficiency of WSHPs and would
increase the cost of testing relative to the current Federal test
procedure, as discussed further in section III.I of this document.
However, as stated, use of appendix C1 will not be required until the
compliance date of any amended standards denominated in terms of IEER,
should DOE adopt such standards. DOE has also determined that the
amended test procedure will not be unduly burdensome to conduct.
For units with cooling capacity greater than or equal to 135,000
Btu/h and less than 760,000 Btu/h newly added within scope of the WSHP
test procedure, testing according to the established test procedure for
purposes of certifications of compliance will not
[[Page 84192]]
be required until the compliance date of any energy conservation
standards for such equipment, should DOE adopt such standards. However,
if a manufacturer chooses to make representations of the energy
efficiency or energy use of such equipment, beginning 360 days after
publication of the final rule in the Federal Register, the manufacturer
will be required to base such representations on the DOE test
procedure. (42 U.S.C. 6314(d)(1))
The effective date for the amended test procedure adopted in this
final rule is 30 days after publication of this document in the Federal
Register. Discussion of DOE's actions are addressed in detail in
section III of this document.
III. Discussion
A. Scope of Applicability
This rulemaking applies to WSHPs, which are a category of small,
large, and very large commercial package air-conditioning and heating
equipment. (See 42 U.S.C. 6311(1)(B)-(D)) In its regulations, DOE
defines WSHP as ``a single-phase or three-phase reverse-cycle heat pump
that uses a circulating water loop as the heat source for heating and
as the heat sink for cooling. The main components are a compressor,
refrigerant-to-water heat exchanger, refrigerant-to-air heat exchanger,
refrigerant expansion devices, refrigerant reversing valve, and indoor
fan. Such equipment includes, but is not limited to, water-to-air
water-loop heat pumps.'' 10 CFR 431.92.
1. WSHPs With a Cooling Capacity Greater Than or Equal to 135,000 Btu/h
The current Federal WSHP test procedure and energy conservation
standards apply to WSHPs with a rated cooling capacity below 135,000
Btu/h. 10 CFR 431.96, Table 1 and 10 CFR 431.97, Table 3. In the August
2022 NOPR, DOE proposed to expand the scope of applicability of the
test procedure to include WSHPs with a cooling capacity between 135,000
and 760,000 Btu/h. 87 FR 53302, 53307. Specifically, DOE proposed to
update Table 1 to 10 CFR 431.96 to include WSHPs with a cooling
capacity greater than or equal to 135,000 Btu/h and less than 240,000
Btu/h under Large Commercial Package Air-Conditioning and Heating
Equipment; and to include WSHPs with a cooling capacity greater than or
equal to 240,000 Btu/h and less than 760,000 Btu/h under Very Large
Commercial Package Air-Conditioning and Heating Equipment. Id. In the
August 2022 NOPR, DOE tentatively determined that, based on the
presence on the market of units over 135,000 Btu/h with efficiency
ratings and the identification of laboratories capable of testing such
units, such testing would not be unduly burdensome. Id. at 87 FR 53306.
Additionally, DOE stated that expanding the scope of DOE's test
procedure for WSHPs to include equipment with a cooling capacity
between 135,000 Btu/h and 760,000 Btu/h would ensure that
representations for all WSHPs are made using the same test procedure
and that ratings for equipment in this cooling capacity range are
appropriately representative. Id. at 87 FR 53306-53307. DOE requested
comments on the proposed expansion of the scope of applicability of the
Federal test procedure to include WSHPs with a cooling capacity between
135,000 and 760,000 Btu/h. Id. at 87 FR 53307.
In response to the June 2022 NOPR, some commenters expressed
concern with the proposal to expand the scope of the test procedure.
AHRI commented that it is concerned with DOE's proposal to expand
testing coverage and update test procedures without taking steps to
measure the impact on manufacturers and third-party test labs. (AHRI,
No. 24 at pp. 2-3) AHRI asserted that the August 2022 NOPR does not
show evidence of DOE's participation in the critical consensus process
required for developing test procedures and improving efficiency for
ASHRAE 90.1, which involves conversations regarding lab capabilities,
product availability, and product efficiencies. (Id.)
AHRI further commented that the impact on manufacturers of DOE's
proposed test coverage expansion has not been quantified. (Id. at p. 3)
AHRI stated that it expects third-party test labs will not be able to
accommodate the expanded scope to include equipment up to 760,000 Btu/
h, as such an expansion of scope would require test labs to increase
their testing capacity from 3 gallons per minute (``GPM'') per ton
(``GPM/ton'') at 50 [deg]F to nearly 200 GPM. (Id.) AHRI commented that
the additional constraints placed on test labs would cause delays in
testing other equipment as well as WSHPs. (Id.)
Similarly, ClimateMaster opposed DOE's proposal to include WSHP
equipment with capacities greater than 135,000 Btu/h within the scope
of the test procedure due to the cost burden that ClimateMaster
asserted would be imposed on manufacturers and consumers.
(ClimateMaster, No. 22 at p. 2) ClimateMaster stated that these larger
model sizes account for only 0.4 percent of its overall market volume
from 2019 to 2021. (Id.) ClimateMaster presented data showing that
adding the higher-capacity models to the scope of the test procedure
would increase the certification cost by $184,000 per year to
accommodate testing and equipment costs. (Id.) ClimateMaster further
commented that third-party compliance labs are unable to test equipment
above 420,000 Btu/h, which would render DOE's proposal to test WSHPs
that reach 760,000 Btu/h impossible. (Id.) ClimateMaster noted that the
increased cost burden needed to accommodate such a small percentage of
affected equipment would negatively affect consumers as well as
manufacturers. (Id.) ClimateMaster recommended that DOE maintain the
scope of applicability of the Federal test procedure to only include
WSHPs with cooling capacity below 135,000 Btu/h. (Id. at p. 3)
FHP commented that its main concern regarding DOE's proposal to
expand the scope of applicability is lab availability. (FHP, No. 26 at
p. 2) FHP stated that it has found only a limited supply of WSHP
testing facilities, none of which have a capacity to test equipment
over 480,000 Btu/h. (Id.) FHP recommended that DOE provide a list of
testing facilities for WSHPs with a cooling capacity greater than
135,000 Btu/h, stating that multiple testing facilities must be
available to ensure that an increased demand for large unit testing
does not also cause spikes in testing costs due to supply and demand
pressures. (Id.) FHP further commented that WSHPs with capacities above
135,000 Btu/h account for less than 1 percent of the market share.
(Id.)
MIAQ commented that it is concerned DOE has not quantified the
impact on manufacturers and third-party labs of expanding the scope of
coverage to larger equipment. (MIAQ, No. 23 at p. 3) MIAQ stated that
conversations regarding lab capabilities and product availability and
efficiency occur during the consensus process required for developing
test procedures in ASHRAE 90.1. (Id.) MIAQ stated that the water volume
required for testing larger capacities up to 760,000 Btu/h may limit
testing. (Id.) More specifically, MIAQ stated that testing a 760,000
Btu/h WSHP would require approximately 200 GPM of 50 [deg]F water,
which MIAQ stated would require large chillers to maintain the water at
the correct temperature. (Id.) MIAQ also noted that due to the
increased need for larger spaces capable of testing such equipment,
there could be bottlenecks at third-party test labs, which also test
other categories of commercial package air conditioning and heating
equipment. (Id.)
[[Page 84193]]
WaterFurnace stated that there are no known WSHP products with a
cooling capacity above approximately 360,000 Btu/h nor any test
facilities capable of testing such WSHPs at the required conditions for
IEER. (WaterFurnace, No. 20 at p. 6) WaterFurnace commented that DOE
did not justify regulating this larger equipment and that doing so
would be a burden on the industry and testing facilities. (Id.)
Other commenters supported the proposal to expand the scope of the
WSHP test procedure. The Joint Commenters, NEEA, and NYSERDA supported
DOE's proposal to include WSHPs with cooling capacities between 135,000
and 760,000 Btu/h in the scope of the test procedure. (Joint
Commenters, No. 27 at p. 1; NEEA, No. 25 at p. 2; NYSERDA, No. 21 at p.
2) The Joint Commenters stated that they believe it is important that
equipment in this capacity range be testing using a standardized test
procedure and that expanding the scope of the test procedure would
bring it into alignment with test procedures for other commercial
package air-conditioning and heating equipment. (Joint Commenters, No.
27 at p. 1)
NEEA commented that, while this size range may account for
relatively few annual sales, expanding the test procedure to larger
capacity equipment would ensure that large equipment is fairly rated
and regulated and held to the same standards as smaller equipment of
the same type. (NEEA, No. 25 at p. 2)
NYSERDA asserted that expanding the scope is a feasible and
necessary change to ensure that WSHPs of varying sizes are consistently
tested according to industry standards, which will demonstrate to
customers that WSHPs--especially geothermal WSHPs--are reliable and
thus enable WSHP market growth. (NYSERDA, No. 21 at p. 2)
As discussed in the August 2022 NOPR, DOE has identified numerous
model lines of WSHPs with a cooling capacity over 135,000 Btu/h from a
wide variety of manufacturers. 87 FR 53302, 53306. The manufacturer
literature for all identified model lines includes efficiency
representations that are explicitly based on ISO 13256-1:1998, the
current industry standard, indicating efficiency representations can be
made for these models using an industry consensus test procedure for
WSHPs. Id.
In response to comments from AHRI, Climate Master, and
WaterFurnace, as discussed in the August 2022 NOPR, DOE is aware of
several independent test labs that have the capability to test WSHPs
with a cooling capacity over 135,000 Btu/h. Id. DOE conducted
investigative testing on multiple WSHP models with a cooling capacity
over 135,000 Btu/h at one such independent test lab and did not
encounter any difficulties specific to units in this capacity range.
Id. Regarding comments by ClimateMaster and FHP stating that test labs
cannot test units greater than 420,000 Btu/h and 480,000 Btu/h,
respectively, comments submitted by WaterFurnace indicate that the
largest models currently available on the market are 360,000 Btu/h,
which DOE research corroborates. As such, any capacity limitations for
testing as asserted by ClimateMaster and FHP would not impact any
models currently on the market.
Further, DOE notes that AHRI 600-2023 includes provisions for
testing units with capacities over 135,000 Btu/h. Both ASHRAE 90.1 and
DOE regulations cover other categories of commercial air conditioning
and heating equipment, including water-cooled commercial unitary air
conditioners (``WCUACs''), with a cooling capacity up to 760,000 Btu/h.
As discussed in the August 2022 NOPR, DOE has determined that testing
WSHPs with a cooling capacity over 135,000 Btu/h would be of comparable
burden to testing other commercial air conditioning and heating
equipment of similar capacity, such as WCUACs. Id.
Regarding comments on the potential burden of testing such units,
EPCA does not require DOE to consider only burden-reducing options, but
rather requires only that the test procedure must not be unduly
burdensome to conduct. Expanding the scope of the test procedure to
include larger equipment would not necessitate certification unless DOE
were to establish standards for such equipment. Until such a time, an
expansion of scope for the test procedure would require only that if
manufacturers choose to make optional representations of efficiency for
WSHPs with a cooling capacity over 135,000 Btu/h, that such optional
representations be made in accordance with the DOE test procedure.
Further, DOE notes that representations for WSHPs can be made either
based on testing (in accordance with 10 CFR 429.43(a)(1)) or based on
alternative efficiency determination methods (``AEDMs'') (in accordance
with 10 CFR 429.43(a)(2)). 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 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.
Whereas DOE requires at least two units to be tested per basic model
when represented values are determined through testing, DOE requires
each AEDM to be validated by tests of only two WSHP basic models of any
capacity (in accordance with 10 CFR 429.70(c)(2)). Based on DOE's
observation of the prevalence of use of AEDMs for WSHP and similar
equipment for which energy conservation standards currently apply
(i.e., for equipment with a cooling capacity no greater than 135,000
Btu/h), DOE expects that representations of efficiency could be
determined through the use of AEDMs for the majority of models with a
cooling capacity over 135,000 Btu/h. As such, DOE expects an expansion
of scope for the DOE test procedure to include equipment with a cooling
capacity over 135,000 Btu/h would not necessitate the testing of many
such larger units. Therefore, testing would not be as burdensome as
noted by commenters.
Based on the presence on the market of units over 135,000 Btu/h,
the identification of laboratories capable of testing such units, DOE's
observation that representations of efficiency for such equipment are
currently being made, and the inclusion of units over 135,000 Btu/h
within the scope of the most recent industry consensus test standard
for WSHPs (AHRI 600-2023), DOE has determined that testing units with a
cooling capacity over 135,000 Btu/h is feasible and would not be unduly
burdensome. As discussed, expanding the scope of DOE's test procedure
for WSHPs to include equipment with a cooling capacity between 135,000
Btu/h and 760,000 Btu/h would ensure that representations for all WSHPs
are made using the same test procedure and that ratings for equipment
in this cooling capacity range are appropriately representative.
For the reasons discussed in the proceeding paragraphs and in the
August 2022 NOPR, DOE is expanding the scope of applicability of the
WSHP test procedure to include WSHPs with a cooling capacity between
135,000 and 760,000 Btu/h consistent with the scope of AHRI 600-2023.
Specifically, DOE is updating Table 1 to 10 CFR 431.96 to include WSHPs
with a cooling capacity greater than or equal to 135,000 Btu/h and less
than 240,000 Btu/h under Large Commercial Package Air-Conditioning and
Heating Equipment and to include WSHPs with a cooling capacity greater
than or equal to 240,000 Btu/h and less than 760,000 Btu/h under Very
Large
[[Page 84194]]
Commercial Package Air-Conditioning and Heating Equipment.
As previously discussed, DOE does not currently specify energy
conservation standards for WSHPs with a cooling capacity over 135,000
Btu/h. DOE would consider any future standards applicable to WSHPs over
135,000 Btu/h in a separate energy conservation standards rulemaking.
Manufacturers of WSHPs with a cooling capacity over 135,000 Btu/h would
not be required to test WSHPs with a cooling capacity over 135,000 Btu/
h until such time as compliance with standards for this equipment were
required, should DOE adopt such standards. DOE notes, however, that
beginning 360 days after this final rule publishes in the Federal
Register, any voluntary representations with respect to energy use or
efficiency must be based on the test procedure in appendix C, and any
voluntary representations of IEER or ACOP must be based on the test
procedure in appendix C1.
2. Representations for Residential Applications
Sections 6.5 and 6.6 of AHRI 600-2023 state that provisions for
determination of residential cooling capacity and efficiency are to be
added in a future revision. In the August 2022 NOPR, DOE proposed to
allow optional energy efficiency ratio (``EER'') and COP
representations at the full-load and part-load EWT conditions specified
in Table 1 of ISO 13256-1:1998 per the DOE test procedure proposed in
appendix C1. 87 FR 53302, 53313. DOE notes that the residential
representations discussed in AHRI 600-2023 are separate from the
proposed optional representations from the August 2022 NOPR, as test
provisions in AHRI 600-2023 specify separate air and liquid external
static pressures to be used during testing to develop ratings for
residential applications. However, the residential representations have
not yet been fully developed for WSHPs, as indicated in sections 6.5
and 6.6 of AHRI 600-2023. Therefore, DOE is not adding any provisions
regarding residential representations in this final rule but will
continue to work with the AHRI 600 committee to develop such
provisions.
B. Definition
As discussed, WSHPs are a category of commercial package air-
conditioning and heating equipment. The current definition for ``water-
source heat pump'' does not explicitly state that it is ``commercial
package air-conditioning and heating equipment.'' This is inconsistent
with the definitions of most other categories of commercial package
air-conditioning and heating equipment (e.g., computer room air
conditioner, single package vertical air conditioner, variable
refrigerant flow multi-split air conditioner). See 10 CFR 431.92.
To provide consistency with other definitions of specific
categories of commercial package air-conditioning and heating
equipment, DOE proposed in the August 2022 NOPR to amend the definition
of ``water-source heat pump'' to explicitly indicate that WSHPs are a
category of commercial package air-conditioning and heating equipment.
87 FR 53302, 53307. This proposed clarification to the ``water-source
heat pump'' definition would not change the scope of equipment covered
by the definition.
In addition, the current definition for WSHPs lists the main
components of a WSHP and it includes ``indoor fan'' on that list. See
10 CFR 431.92. DOE discussed in the August 2022 NOPR that it has
identified coil-only WSHPs on the market that rely on a separately
installed furnace or modular blower for indoor air movement. 87 FR
53302, 53307. To clarify that coil-only WSHPs are covered under the
WSHP definition, DOE proposed to amend the WSHP definition to make
clear that an indoor fan is not an included component for coil-only
WSHPs. Id. Specifically, DOE proposed to include the parenthesized
statement ``except that coil-only units do not include an indoor fan''
in the sentence listing the main components in the proposed WSHP
definition. Id.
DOE requested comment on the proposed change to the definition of
WSHP to explicitly indicate that WSHP is a category of commercial
package air-conditioning and heating equipment and to clarify that the
presence of an indoor fan does not apply to coil-only units. Id.
ClimateMaster generally agreed with DOE's proposed definition of
WSHP, but requested clarity on what constitutes a commercial system.
(ClimateMaster, No. 22 at p. 3) ClimateMaster commented that other
industry test programs clearly demarcate the difference between systems
through listed capacity. (Id.) ClimateMaster noted that the current
definition includes only packaged systems but that DOE's proposed
amendments in the August 2022 NOPR specified procedures for testing
split systems. (Id.) ClimateMaster stated that it is not able to
determine with the current definition what exact products would fall
under the certification program and how DOE would enforce which
products are covered by the applicable standards. (Id.) ClimateMaster
also stated that there were non-reversible WSHP products that operate
as either cooling only units or utilize a hydronic coil that are not
covered by the current definition. ClimateMaster stated that provisions
should be made for this equipment type. (Id.)
WaterFurnace questioned whether it would be necessary to change the
definition of WSHP if DOE were to maintain the method of test based on
ISO 13256 and AHRI 600. (WaterFurnace, No. 20 at p. 6) WaterFurnace
recommended using the term ``heat pump'' in lieu of ``air conditioner
and heating equipment,'' which WaterFurnace asserted is technically
inaccurate. (Id.)
Regarding ClimateMaster's request for clarity regarding the
definition, DOE notes that all products that meet the WSHP definition,
with sizes less than 760,000 Btu/h cooling capacity (see discussion in
section III.A of this final rule), would be considered a WSHP,
regardless of whether the models are marketed and distributed in
commerce for commercial or residential applications. The definition of
WSHPs includes both single-package and split-system equipment.
Regarding WaterFurnace's comment on whether it would be necessary
to change the definition of WSHP if DOE were to maintain the method of
test based on ISO 13256 and AHRI 600, the DOE definition of WSHP serves
to specify models that are within the scope of coverage of DOE's
regulations and is independent of the test procedure being used for
WSHPs. DOE also notes in response to WaterFurnace's comment that the
definition of WSHP already uses the term ``heat pump'' to define WSHP
and that the term ``commercial package air-conditioning and heating
equipment'' is being added to the definition only to indicate the
larger type of equipment, as defined in the EPCA, of which WSHPs are a
category.
Regarding ClimateMaster's comment that the current definition does
not cover units that are not reversible, DOE considers water-source
heat pumps to include only models with reverse-cycle heating;
therefore, DOE is not removing the ``reverse-cycle'' provision from the
WSHP definition.
For the reasons discussed, DOE is adopting an amended definition of
WSHP that is identical to the definition proposed in the August 2022
NOPR, as follows:
Water-source heat pump means commercial package air-conditioning
and heating equipment that is a single-phase or three-phase reverse-
cycle heat pump that uses a circulating water loop as the heat source
for heating and as the
[[Page 84195]]
heat sink for cooling. The main components are a compressor,
refrigerant-to-water heat exchanger, refrigerant-to-air heat exchanger,
refrigerant expansion devices, refrigerant reversing valve, and indoor
fan (except that coil-only units do not include an indoor fan). Such
equipment includes, but is not limited to, water-to-air water-loop heat
pumps.
C. Organization of the Amended DOE Test Procedures
In this final rule, DOE is relocating and centralizing the current
test procedure for WSHPs to a new appendix C to subpart F of part 431
and establishing an amended test procedure for WSHPs in a new appendix
C1 to subpart F of part 431. Appendix C maintains the substance of the
current test procedure and continues to reference ISO 13256-1:1998 and
provide for determining EER and COP. Appendix C also includes the
additional test provisions for equipment set-up currently codified at
10 CFR 431.96(e). As discussed, WSHPs are required to be tested
according to appendix C until such time as compliance is required with
an amended energy conservation standard based on the amended test
procedure in appendix C1, should DOE adopt such a standard.
DOE is also establishing an amended test procedure for WSHPs in a
new appendix C1 to subpart F of part 431 that includes provisions for
determining IEER and ACOP by incorporating by reference AHRI 600-2023,
as discussed further throughout this document. WSHPs are not required
to be tested according to appendix C1 until such time as compliance is
required with an amended energy conservation standard denominated in
terms of the IEER metric, should DOE adopt such a standard; although,
any voluntary representations of IEER prior to the compliance date of
any such standard must be based on testing according to appendix C1.
D. Updates to Industry Standards
As noted in section I.B. of this document, the DOE test procedure
currently incorporates by reference ISO 13256-1:1998 and includes
additional provisions for equipment set-up at 10 CFR 431.96(e), which
provide specifications for addressing key information typically found
in the installation and operation manuals. In the August 2022 NOPR, DOE
proposed to adopt an amended test procedure for WSHPs in a new appendix
C1 that would incorporate by reference AHRI 340/360-2022 for measuring
efficiency using IEER. 87 FR 53302, 53311. Because AHRI 340/360-2022
references ANSI/ASHRAE 37-2009 for test provisions, DOE also proposed
to incorporate by reference relevant sections of ANSI/ASHRAE 37-2009 in
its amended test procedure for WSHPs. Id. at 87 FR 53312. Compared to
the current test procedure, the key substantive changes that would
result from DOE adopting the proposed test procedure included the
following:
(1) A new energy efficiency descriptor, IEER, which incorporates
part-load cooling performance;
(2) Modified test conditions for determining COP;
(3) Minimum external static pressure (``ESP'') requirements,
instructions for setting airflow and ESP, and tolerances for airflow
and ESP, and
(4) Specified liquid ESP requirements for units with integral pumps
and a method to account for total pumping effect for units without
integral pumps. Id. at 87 FR 53305.
In response to this proposal, DOE received multiple comments
(summarized in the following sub-sections) urging DOE not to
incorporate by reference AHRI 340/360-2022 as the test procedure for
WSHPs, to continue to collaborate with industry on finalizing AHRI 600,
and to instead adopt the revised industry test standard resulting from
work on AHRI 600. As previously noted, after publication of the August
2022 NOPR, DOE worked with the AHRI Geothermal and WSHP STC to develop
a revised version of AHRI 600 (AHRI 600-2023) to address the issues DOE
raised in the August 2022 NOPR. As discussed further throughout this
section, AHRI 600-2023 includes a method to determine IEER for WSHPs
similar to that proposed in the August 2022 NOPR and addresses many of
the concerns expressed by commenters in response to the August 2022
NOPR. As discussed, AHRI 600-2023 is intended to serve as the primary
industry test procedure for WSHPs going forward and it does not
reference any versions of ISO Standard 13256-1. Instead, AHRI 600-2023
references ANSI/ASHRAE 37-2009 and includes sufficient provisions for
testing WSHPs that references to test provisions in ISO Standard 13256-
1 or AHRI 340/360-2022 are not needed.
As discussed further throughout this section, in this final rule,
DOE is adopting an amended test procedure that incorporates by
reference AHRI 600-2023, with minor differences as explained further
throughout the following sections of this document.
In the following sections, DOE summarizes comments received in
response to the August 2022 NOPR with regard to industry standards.
1. Comments Regarding DOE's Authority
As discussed previously in this document, with respect to small,
large, and very large commercial package air conditioning and heating
equipment (of which WSHPs are a category), EPCA directs that when the
generally accepted industry testing procedures or rating procedures
developed or recognized by AHRI or by ASHRAE, as referenced in ASHRAE
90.1, are amended, the Secretary shall amend the DOE test procedure
consistent with the amended industry test procedure or rating procedure
unless the Secretary determines, by clear and convincing evidence, that
to do so would not meet the requirements for test procedures to produce
results representative of an average use cycle and is not unduly
burdensome to conduct. (42 U.S.C. 6314(a)(4)(A)-(B))
In response to the August 2022 NOPR, AHRI, MIAQ, and WaterFurnace
expressed concern with DOE's proposal to adopt a test procedure
different from the industry standard (i.e., ISO 13256-1:1998 and the
not yet published AHRI 600 standard), and the procedure cited in ASHRAE
90.1. (AHRI, No. 24 at pp. 1-2; MIAQ, No. 23 at pp. 1-2; WaterFurnace,
No. 20 at p. 1) AHRI, MIAQ, and WaterFurnace noted that EPCA explicitly
directs DOE to adopt the industry consensus test procedure cited in
ASHRAE 90.1 and asserted that EPCA precludes DOE from adopting as a
national standard a wholly different test procedure from that cited in
ASHRAE 90.1. (Id.) These commenters urged DOE to adopt a revised test
method only after it has been published by AHRI and adopted by ASHRAE
in ASHRAE 90.1. (Id.)
MIAQ asserted further that EPCA requires DOE to justify by clear
and convincing evidence each amendment or difference between AHRI 340/
360-2022 and ISO 13256-1:1998. (MIAQ, No. 23 at p. 2) MIAQ commented
that DOE has determined in past rulemakings that ISO 13256-1 is cost
effective and representative of energy use. (Id.) MIAQ stated that any
deviation from ASHRAE 90.1 requires quantification of the burden and
that only modifications that reduce testing burden on manufacturers can
be considered. (Id. at p. 3)
AHRI and MIAQ commented that DOE and outside stakeholders have been
developing a consensus-based revision to the test procedure for
commercial packaged air conditioners and heat pumps (``CUAC/HPs'').
(AHRI,
[[Page 84196]]
No. 24 at p. 2; MIAQ, No. 23 at p. 2) AHRI and MIAQ further stated that
after AHRI 600 has been finalized and adopted, AHRI will introduce the
new test procedure to ASHRAE 90.1 to begin the procedural process for
updates. (AHRI, No. 24 at p. 3; MIAQ, No. 23 at p. 2) AHRI and MIAQ
commented that waiting to harmonize standards would establish
consistent energy efficiency levels and design requirements between
industry and Federal requirements, as well as comparable metrics and
scope. (AHRI, No. 24 at p. 3; MIAQ, No. 23 at pp. 2-3) AHRI and MIAQ
recommended that DOE continue to work with AHRI and other stakeholders
to finalize AHRI 600 and support a proposed amendment to ASHRAE 90.1,
which DOE could adopt as the national test procedure during the next
rulemaking. (AHRI, No. 24 at p. 4; MIAQ, No. 23 at pp. 3, 9)
ClimateMaster commented that DOE has not followed a cooperative
approach to improve the test methods as proposed in the August 2022
NOPR. (ClimateMaster, No. 22 at p. 1) ClimateMaster asserted that this
seems to violate EPCA, which requires DOE to adopt the test procedure
cited in ASHRAE 90.1. (Id.)
With regard to comments asserting that DOE does not have the
authority to adopt a test procedure prior to its inclusion in ASHRAE
90.1, EPCA provides DOE with authority to adopt an amended test
procedure in satisfaction of EPCA's 7-year-lookback review requirement
for test procedures. (42 U.S.C. 6314(a)(1)(A)). Under its 7-year-
lookback review, DOE must ensure that test procedures established are
reasonably designed to produce test results which reflect energy
efficiency, energy use, and estimated operating costs during a
representative average use cycle and are not unduly burdensome to
conduct. (42 U.S.C. 6314(a)(2)) During its 7-year lookback review, DOE
is directed by EPCA to evaluate whether an amended test procedure would
more accurately or fully comply with those requirements, and if DOE
determines an amended test procedure would do so, then DOE is required
to prescribe such test procedures for the equipment class. (42 U.S.C.
6314(a)(1)(A)) It is important to note that under the 7-year lookback
DOE does not need clear and convincing evidence that an amended test
procedure would more accurately or fully comply with EPCA's
requirements. (Id.) Rather, DOE must show that the amended test
procedure is reasonably designed to produce test results which reflect
energy efficiency, energy use, and estimated operating costs during a
representative average use cycle and are not unduly burdensome to
conduct. (42 U.S.C. 6314(a)(2)) For example, a test procedure
referenced by ASHRAE 90.1 may not be reasonably representative because
more representative test procedures are available. And a test procedure
that was reasonably representative in the past may become unreasonably
representative when newly available test procedures allow for better,
more complete measurements. DOE's 7-year-lookback review under EPCA
ensures that DOE is not bound to an industry test procedure that has
not been updated and is no longer representative of current equipment.
DOE notes that submitted comments from AHRI, WaterFurnace,
ClimateMaster, and MIAQ do not mention DOE's 7-year-lookback review and
therefore only engaged with the review process under 42 U.S.C.
6314(a)(4)(A). AHRI stated in its written comment that DOE is mandated
to adopt an industry test procedure only after that test procedure is
adopted in ASHRAE 90.1 but identified no such mandate within the
statute itself. It is important to note that the 7-year-lookback review
language at issue here was added to EPCA in EISA 2007, well after the
relevant ASHRAE 90.1 test procedure language was added in 1992.
(Compare Sec. 302 of EISA 2007, Pub. L. 110-140, 121 STAT. 1552 (Dec.
19, 2007) with Sec. 121 of the Energy Policy Act of 1992, Pub. L. 106-
486, 106 STAT. 2808 (Oct. 24, 1992)). Therefore, the most natural
reading of the two provisions together is that Congress intended to add
the 7-year-lookback review to those triggers for review of test
procedures that already existed. The language of the 7-year-lookback
review applies generally to all covered equipment. Rather than restrict
DOE to an outdated test procedure in the manner the industry commenters
suggest, EPCA instead compels DOE to use due diligence to review the
totality of relevant and available information before settling on
appropriate energy conservation standards and test procedures.
As a result, it is appropriate for DOE to consider in its 7-year-
lookback whether amendments to the test procedure would more accurately
produce test results which reflect energy efficiency, energy use, and
estimated operating costs during a representative average use cycle and
would not be unduly burdensome to conduct even without an update to
AHSRAE 90-1. DOE finds here that the test procedure provided in the
updated industry consensus test standard for WSHPs (AHRI 600-2023), and
therefore the test procedure specified in the regulatory text of this
final rule, is more representative without incurring undue burden, as
discussed below, thereby satisfying EPCA's requirements.
DOE acknowledges that DOE has previously stated that it will only
consider an update to ASHRAE 90.1 that modifies the referenced industry
test procedure to be a trigger under that provision of the statute, as
opposed to an update of just the industry test procedure itself. (See
e.g., 86 FR 35668, 35676 (July 7, 2021)). DOE stands by that position
regarding what constitutes a triggering event in the context of ASHRAE
equipment and does not consider the provisions in 42 U.S.C. 6314(a)(4)
to have been triggered. However, that does not preclude DOE from
considering an amended test procedure when reviewing DOE's test
procedures under EPCA's 7-year-lookback provision. Not only does DOE
have discretion to do so, but it has a statutory duty to do so, to
ensure that its test procedures produce results that are representative
of an average use cycle and are not unduly burdensome to conduct.
DOE has determined that the test procedure adopted in this final
rule for WSHPs would improve the representativeness of the current
Federal test procedure for WSHPs and would not be unduly burdensome.
Specifically, DOE has concluded that testing WSHPs in accordance with
AHRI 600-2023 would provide more representative results and more fully
comply with the requirements of paragraph (2) of 42 U.S.C. 6314(a) than
testing in accordance with the currently referenced standard ISO 13256-
1:1998, as discussed in more detail in section III.D.6 of this final
rule. And while clear and convincing evidence is not needed when
amending a test procedure under the 7-year-lookback, DOE finds that the
test procedure amendments adopted here are supported by clear and
convincing evidence as outlined in this final rule. DOE discusses the
specific test procedure updates included in appendix C1, resulting from
the incorporation by reference of AHRI 600-2023, in sections III.E and
III.F of this final rule. Therefore, DOE is adopting an amended test
procedure for WSHPs that incorporates by reference AHRI 600-2023, with
minor deviations. With regard to the assertion by AHRI and MIAQ that
any deviation from ASHRAE 90.1 requires quantification of the burden,
and MIAQ's assertion that only modifications that reduce testing burden
on manufacturers can be considered, DOE does not agree that EPCA
requires DOE to consider only deviations that
[[Page 84197]]
would reduce burden. Rather, EPCA requires only that DOE ensure that
test procedures established are not unduly burdensome to conduct. (42
U.S.C. 6314(a)(2))
With regard to the assertion by AHRI and MIAQ that EPCA requires
DOE to justify by clear and convincing evidence each amendment or
difference from the industry test procedure referenced by ASHRAE 90.1,
DOE does not agree that EPCA requires such a line-by-line assessment of
an amended test procedure. First, as stated previously, there is no
requirement for clear and convincing evidence in EPCA for a test
procedure amendment under the 7-year-lookback. Additionally, if DOE
were amending a test procedure pursuant to the ASHRAE trigger, EPCA
requires only that DOE shall amend the test procedure for the product
as necessary to be consistent with the amended industry test procedure
or rating procedure unless it determines, supported by clear and
convincing evidence, that to do so would not meet the requirements of
EPCA (42 U.S.C. 6314 (a)(4)(B)). If DOE makes such a determination, DOE
may establish an amended test procedure, but there is no requirement
for DOE to show, by clear and convincing evidence, that DOE's amended
test procedure is reasonably designed to produce test results which
reflect energy efficiency, energy use, and estimated operating costs
during a representative average use cycle and are not unduly burdensome
to conduct. (See 42 U.S.C. 6314(a)(2)). Additionally, if DOE does not
make such a determination, there is no requirement that DOE show, by
clear and convincing evidence, that an amended test procedure, which is
consistent with the industry test procedure, is reasonably designed to
produce test results which reflect energy efficiency, energy use, and
estimated operating costs during a representative average use cycle and
are not unduly burdensome to conduct.
2. Comments Regarding DOE's Test Procedure Development Process
In response to the June 2022 NOPR, DOE received comments regarding
its rulemaking development process. AHRI recommended that DOE follow a
transparent, cooperative, or consensus-based regulatory development
process. (AHRI, No. 24 at p. 4) AHRI commented that, in the past, DOE
has had difficulty duplicating test results without the help and
guidance of manufacturers and AHRI testing facilities and that the
complex controls and operational characteristics of WSHP equipment
require manufacturer and testing facility experience to test properly.
(Id.) AHRI acknowledged that DOE has tested 15 units from the WSHP
industry but stated that DOE did not release the data and results of
the testing. (Id.) AHRI expressed further concern that the testing
cited in the August 2022 NOPR was not shared with the relevant AHRI
committee and requested that DOE share the results of its findings with
stakeholders in order to allow for validation and review. (Id. at pp.
2, 4)
AHRI recommended that DOE work with industry on finalizing AHRI
600, conduct any necessary testing or calculations to develop a
document agreed upon by DOE and relevant stakeholders, and follow the
proper procedures to introduce the finalized test procedure and updated
efficiency standards in ASHRAE 90.1. (Id.) AHRI commented that it will
support the necessary updates to the Federal procedure and metrics
after DOE takes the aforementioned steps. (Id.)
ClimateMaster commented that DOE did not follow a cooperative
process to improve the test methods for WSHPs and that neither AHRI nor
the WSHP industry was consulted in a working group setting with other
stakeholders, which was inconsistent with past and current industry
approaches. (ClimateMaster, No. 22 at p. 1)
WaterFurnace commented that it believed a more transparent and
consensus-based development process is warranted before DOE implements
new WSHP test procedures and that DOE should seek industry and AHRI
input in order to validate and review the testing results.
(WaterFurnace, No. 20 p. 2) WaterFurnace recommended that DOE implement
an Appliance Standards and Rulemaking Federal Advisory Committee
(``ASRAC'') Working Group for all future undertakings to propose
substantial changes in regulatory policy so as to work out complex
issues in a common forum with industry and AHRI. (Id.)
With respect to the comments from AHRI, ClimateMaster, and
WaterFurnace, DOE notes that it may establish a negotiated rulemaking
working group under ASRAC in accordance with the Federal Advisory
Committee Act (``FACA'') and the Negotiated Rulemaking Act (``NRA'') (5
U.S.C. 561-570, Pub. L. 104-320) to negotiate proposed test procedures
and amended energy conservation standards if DOE determines that the
use of the negotiated rulemaking process is in the public interest
according to the requirements of FACA and in a manner consistent with
the requirements of the NRA. However, in this rulemaking, DOE is
following the traditional rulemaking notice-and-comment process.
DOE recognizes the benefits of developing test procedures through a
consensus-based process and notes that DOE has participated in the AHRI
process and has worked with the AHRI Geothermal and WSHP STC in
developing AHRI 600-2023, which is incorporated by reference in this
final rule. As noted in the August 2022 NOPR, DOE has participated in
AHRI committee meetings working to develop AHRI 600 since 2019. See 87
FR 53302, 53308-53309. In particular, DOE brought up many of the
concerns raised in August 2022 NOPR in ISO 13256-1 and AHRI 600
meetings for several years prior to the publication of the August 2022
NOPR, but the committees declined to address these issues in the draft
industry test procedures at that time. At the time of drafting of the
August 2022 NOPR, AHRI 600 was still in development and had not yet
published. In the August 2022 NOPR, DOE outlined its understanding that
the intent of AHRI 600 would be to provide a method for calculation of
IEER for WSHPs based on testing conducted according to ISO 13256-
1:1998. Id. at 87 FR 53309. In the August 2022 NOPR, DOE tentatively
concluded that the general methodology in AHRI 600 for determining IEER
is appropriate. Id. However, DOE identified several aspects of the
methodology that warrant further modifications. Id. In the August 2022
NOPR, DOE noted that it could not speculate as to the substantive
outputs of the ISO 13256-1 National deviation and the AHRI 600
committee's efforts. Id. Consistent with DOE's procedure for notice-
and-comment rulemakings, DOE also conducted the NOPR public meeting
that provided opportunity for stakeholders to provide feedback on DOE's
proposals. The feedback DOE received in both NOPR public meeting
comments and written comments was considered in subsequent AHRI 600
committee meetings and drafting of this final rule.
Since the publication of the August 2022 NOPR, DOE continued to
work with industry in AHRI 600 committee, as recommended by commenters,
to address the test procedure concerns DOE raised in the August 2022
NOPR with the intent that a revised industry test procedure specific to
WSHPs could be adopted in a final rule. Rather than continue to
simultaneously modify and maintain ISO 13256-1 and AHRI-600, the
committee members voted to merge them into a comprehensive unified test
procedure, AHRI 600. More specifically, the methodology specified in
ISO 13256-1 has been incorporated into
[[Page 84198]]
AHRI 600-2023. Therefore, AHRI 600-2023 does not reference ISO 13256-1.
Regarding AHRI's comment about sharing data, DOE presented the
results of its testing in the August 2022 NOPR. Id. at 87 FR 53314-
53317. Based on participation in AHRI 600 committee meetings following
the August 2022 NOPR, additional data from DOE's investigative testing
was not needed for the committee to reach resolution on the content of
AHRI 600-2023.
On September 11, 2023, AHRI 600-2023 was published. DOE notes that
the statutory deadline for publishing a test procedure final rule for
WSHPs was May 16, 2019. (42 U.S.C. 6314(a)(1)) Given EPCA's statutory
requirement to review the appropriate test procedures for WSHPs every
seven years, DOE has concluded that it would be neither appropriate nor
permissible to delay the current rulemaking for the WSHP test procedure
until after ASHRAE 90.1 adopts AHRI 600-2023 as the test procedure for
WSHPs. To avoid any further delay, DOE is adopting a test procedure for
WSHPs that incorporates by reference AHRI 600-2023, with minor
deviations.
3. Comments Supporting the Adoption of AHRI 340/360-2022
In response to the June 2022 NOPR, some commenters supported
adopting AHRI 340/360-2022 in the WSHP test procedure. NEEA generally
supported DOE's efforts to align the WSHP test procedure with other
water-cooled unitary systems, including by integrating fan energy into
the test procedure for ducted WSHPs. (NEEA, No. 25 at p. 1) In
particular, NEEA supported DOE's proposal to align the WSHP test
procedure with AHRI 340/360-2022 and ANSI/ASHRAE 37-2009. (Id. at p. 2)
NEEA stated that aligning the testing of WSHPs with ANSI/ASHRAE 37-2009
would ensure that WSHP ratings will be consistent with other water-
cooled and direct expansion cooling systems. (Id.) NEEA also supported
the introduction of an IEER metric rather than rating only with EER.
(Id.) NEEA stated that the proposed test procedure would impact the
current modeling approach for WSHP standard reference systems used to
determine total system performance ratio in the 2018 Washington State
Energy Code, but NEEA acknowledged that potential advancements to the
test procedure and ratings metric would provide an important
improvement in representativeness for this equipment. (Id. at p. 1)
NYSERDA generally supported DOE's proposed amendments for the WSHP
test procedure and concurred with DOE's tentative determination that
the changes would improve the representativeness of the WSHP test
procedure. (NYSERDA, No. 21 at pp. 1-2) NYSERDA asserted that this
would spur growth in the market for WSHPs, including geothermal heat
pumps. (Id. at p.2)
As discussed previously, in this final rule, DOE is incorporating
by reference AHRI 600-2023 into appendix C1 in lieu of incorporating by
reference AHRI 340/360-2022 as proposed in the August 2022 NOPR. DOE
notes, however, that the majority of the technical content from the
proposed test procedure in the August 2022 NOPR remains consistent in
the test procedure finalized in this final rule. Any changes to
technical provisions from the August 2022 NOPR proposal were due to
industry consensus culminating in the AHRI 600-2023 standard.
Throughout this final rule, DOE discusses in detail the technical
differences between the test procedure proposed in the August 2022 NOPR
and the version finalized in this final rule.
4. Comments Opposing the Adoption of AHRI 340/360-2022
Other commenters opposed the proposal in the August 2022 NOPR to
adopt AHRI 340/360-2022 in the WSHP test procedure. AHRI and MIAQ
expressed concern that the impact on manufacturers of DOE's proposal to
update the WSHP test procedure has not been quantified. (AHRI, No. 24
at p. 2; MIAQ, No. 23 at p. 3) AHRI and MIAQ stated that the capability
of testing WSHPs to AHRI 340/360-2022 has not been assessed by third-
part test labs. (Id.)
AHRI and MIAQ noted that an ASRAC Working Group has been formed in
an effort to negotiate test procedures and energy efficiency standards
for CUAC/HPs, the scope of which stands to result in significant
modifications to AHRI 340/360-2022 and the efficiency measures for such
equipment. (AHRI, No. 24, at p. 2; MIAQ, No. 23 at p. 2) AHRI and MIAQ
further noted, however, that WSHPs are outside the scope of these
efforts, potentially leaving a significant gap in ratings (i.e., were
WSHPs to be rated using AHRI 340/360). (Id.)
WaterFurnace expressed concern regarding DOE's sampling and testing
procedure for modifying AHRI 340/360, especially considering the
complexity of the product's controls and operational characteristics
and taking into account past instances in which DOE has struggled to
duplicate test results without manufacturer and AHRI testing support.
(WaterFurnace, No. 20 at p. 2)
WaterFurnace agreed with AHRI's concerns that the impact on
manufacturers of DOE's proposal to update test procedures has not been
adequately quantified, nor was it clear whether third-party test labs
have the capability to accommodate the proposed changes. (Id. at p. 2)
WaterFurnace, ClimateMaster, Enertech, and FHP all expressed
concern that DOE's proposal to test WSHPs using AHRI 340/360-2022 would
require manufacturers to test WSHPs to two different test standards
because geothermal applications for WSHPs would still require testing
to ISO 13256-1. (WaterFurnace, No. 20 at p. 3; ClimateMaster, No. 22 at
p. 1; Enertech, No. 19 at p. 1; FHP, No. 26 at p. 3) WaterFurnace noted
that ISO 13256-1 is already referenced in several Federal, State, and
local codes. (WaterFurnace, No. 20 at p. 3) WaterFurnace and
ClimateMaster stated that implementing a dual certification process
would be burdensome for manufacturers. (WaterFurnace, No. 20 at p. 3;
ClimateMaster, No. 22 p. 1) Enertech also noted that Federal and State
tax credits specifically reference ISO/AHRI 13256-1:1998 for efficiency
ratings and that the ENERGY STAR specifications directly reference the
ISO 13256-1:1998 standard for the ENERGY STAR Tier 3 efficiency
requirements. (Enertech, No. 19 at p. 1)
WaterFurnace asserted that DOE underestimated the significance and
the burden that the proposed changes to the WSHP test procedure would
impose upon manufacturers and industry players. (WaterFurnace, No. 20
at p. 3) WaterFurnace identified the following assumptions and
shortcomings in AHRI 340/360-2022 that it stated were not appropriately
addressed in the August 2022 NOPR:
(1) While the August 2022 NOPR stated that IEER can be calculated
and an interpolation can be performed using existing data from ISO
13256-1, WaterFurnace determined that the entering air, water flow,
external static and airflow conditions differ from AHRI 340/360-2022,
which will therefore require additional testing by the manufacturer and
the implementation of a new certification program;
(2) Currently, performance mapping capability is available across a
wide range of entering water temperatures (``EWT'') used in modeling
software such as EQuest and DOE's EnergyPlus, and all of this detail
would be lost with the implementation of AHRI 340/360-2022 because it
only presents a single IEER cooling metric and a single heating point;
[[Page 84199]]
(3) Provisions should be added under AHRI 340/360-2022 for hybrid
heat pumps, which are unique in their capability for refrigerant
cooling with other non-refrigerant heating capability;
(4) Provisions should be added under AHRI 340/360-2022 for split
configurations, which are offered for smaller WSHPs;
(5) Provisions should be added under AHRI 340/360-2022 for small
WSHPs with non-ducted applications (e.g., console units), along with
language that takes into account the fact that many of these units are
installed into residential buildings with substantial heating that
would not fit the AHRI 340/360-2022 conditions;
(6) While DOE proposed to adopt heating test conditions for WSHPs
that are not specified in AHRI 340/360-2022, this overlooks other
testing requirements and language that would need to be addressed
(e.g., minimum and maximum operating conditions) in order to adequately
add heating tests to a cooling-only standard;
(7) Provisions should be added under AHRI 340/360-2022 for
antifreeze blends and their fluid characteristics (i.e., alcohols,
salts, and glycols);
(8) Test procedures would need to be modified to account for
smaller WSHP units, as AHRI 340/360-2022 requires an airflow tolerance
of less than 3 percent and is thus designed around larger product
designs with drives and adjustable sheaves that accommodate this
airflow capability;
(9) Although AHRI 340/360-2022 is primarily an air-source standard
that utilizes air and refrigerant enthalpy test methods, water-source
equipment is more consistently and accurately tested with a liquid
enthalpy test method and would need to use air or refrigerant enthalpy
only as secondary methods--and, furthermore, this process would be
inconsistent with part load measurements under AHRI 340/360-2022;
(10) Manufacturer-specified liquid flow rate is preferred over the
AHRI 340/360-2022 method of setting liquid flow rate using a 10 [deg]F
temperature rise to establish flow rates;
(11) Continuous 24/7 fan operation is an outdated idea according to
ASHRAE 90.1; and
(12) Issues addressed by Working Groups under ASRAC will likely
result in massive changes to AHRI 340/360 regarding air-side
measurements and will take focus away from necessary modifications to
provisions for water-cooled units and, thus, changes for water-cooled
units to AHRI 340/360 will likely be of secondary importance to the
ASRAC committee. (Id. at pp. 3-4)
WaterFurnace also commented that because AHRI 340/360-2022 is
primarily an air-source standard, AHRI 340/360-2022's comparatively
small water-cooled section is used to certify approximately 1,000 units
per year in contrast to the 200,000 unit sales per year under the AHRI/
ISO 13256 certification programs. (Id. at p. 5) Therefore, WaterFurnace
noted that moving testing of WSHPs (with much higher shipments) to the
smaller water-cooled section of AHRI 340/360-2022 would not be logical
considering the noted changes required. (Id.)
WaterFurnace commented that changing to a different AHRI 340/360-
2022 standard and separating out geothermal applications to ISO 13256
would be disruptive to both the water-source and geothermal industries
at a time when the use of heat pumps is being encouraged by national,
state, and local regulations as a carbon-reduction solution. (Id.)
WaterFurnace stated that tax credits and rebates based upon AHRI/ISO
13256 performance have been legislatively codified and will be
difficult to change, and further noted that the Inflation Reduction Act
references ASHRAE 90.1 and AHRI/ISO 13256 as a measurement of
performance. (Id. at p. 6) WaterFurnace stated that other governmental
programs such as ENERGY STAR have specifications and benefits based on
AHRI/ISO 13256 performance certification and that decarbonization
policy programs by utilities, cities, and states rely on such
certification as well. (Id.)
ClimateMaster commented that DOE would need to address the
following issues with AHRI 340/360-2022:
(1) AHRI 340/360-2022 needs to be updated to include the appendix
C1 additions, a process that will likely be delayed by a current ASRAC
working group undertaking to amend the current AHRI 340/360-2022 test
procedures with a focus on air-source equipment;
(2) AHRI 340/360-2022 does not include test requirements for water-
source heating;
(3) AHRI 340/360-2022 does not include test provisions for non-
ducted equipment;
(4) The airflow setting and tolerance specified by AHRI 340/360-
2022 does not cover or is incompatible with current WSHP equipment;
(5) AHRI 340/360-2022 does not include a pump power adder for all
equipment sizes, nor is DOE's proposal to utilize the pump power adder
in AHRI 920 representative of installed WSHP systems;
(6) AHRI 340/360-2022 does not include glycols or antifreeze
solutions in the method of test, and the recommended solution is not
representative of the fluids used for WSHPs in the field or test
laboratories currently used in the development, qualification, and
compliance processes; and
(7) The refrigerant charging requirements included in AHRI 340/360-
2022 are not applicable, accurate, or relevant to WSHP systems.
(ClimateMaster, No. 22 at pp. 1-2)
Enertech commented that AHRI 340/360-2022 lacks testing parameters
for water source heating, testing parameters for non-ducted equipment,
testing methods utilizing antifreeze blends, and parameters for pump
power adder for small equipment. (Enertech, No. 19 at p. 1) Enertech
noted that AHRI 340/360-2022 requires a 3 percent airflow
tolerance during testing, which Enertech asserted is unrealistic for
small-capacity equipment. (Id.) For these reasons, Enertech disagreed
that new efficiency ratings could be interpolated from conditions
common to the WSHP industry and asserted that new testing would be
required for all products offered by any manufacturer. (Id.) Enertech
stated that adopting AHRI 340/360-2022 as the DOE test procedure for
WSHPs would result in long-term disruptions to the geothermal and WSHP
industries. (Id. at p. 2)
FHP commented that adopting test methods per AHRI 340/360-2022
would require additional testing effort, time, and resources, and would
result in additional costs to the industry. (FHP, No. 26 at p. 3) FHP
commented further that AHRI 340/360-2022 contains differences in
standard test conditions that would require additional testing as well
as changes to (1) the design of the units to ensure 10 [deg]F
temperature rise on the water side and (2) the fan/motor selections and
programs to maintain the proper air flow at defined static pressures
and airflow tolerances. (Id.) FHP stated that the use of two standards
may split the current WSHP product designs, thereby adding permanent
design burden to current product offerings. (Id.)
FHP stated that the proposed changes to the WSHP test procedure
could be the most impactful regulatory issue for the WSHP industry and
that the industry's resources are completely dedicated to the
development of equipment that uses low-global warming potential
refrigerants through January 1, 2025. (FHP, No. 26 at p. 5) FHP
expressed concern about the impact of moving to an entirely new test
procedure that would require re-testing, re-designing, and potentially
re-certifying most of its basic model groups. (Id.) FHP also
[[Page 84200]]
expressed concerns about the additional resources and maintenance
potentially required by having two separate product designs and
validations for WSHPs. (Id.)
FHP also stated that current AEDMs are based on the leading
industry standard for these types of equipment. (Id. at p. 2) More
specifically, FHP stated that its current AEDM is based on the ISO
13256-1:1998 test standard and that DOE's proposal to reference AHRI
340/360-2022 as the test procedure for WSHPs would require additional
testing and new AEDMs. (Id.) FHP commented that even reduced testing to
validate AEDMs would be unduly burdensome for such a small market.
(Id.)
During the public meeting, AAON commented that the amount of
testing in the proposed test procedure was rather extreme and asked DOE
to share the testing burden assessment. (Public Meeting Transcript, No.
17 at p. 60)
GeoExchange commented that manufacturers of geothermal heat pumps
have significant concerns with the August 2022 NOPR as written and
believe it will subject WSHPs and geothermal heat pumps to competing
and inconsistent certification standards. (GeoExchange, No. 29 at p. 1)
GeoExchange commented that these issues will complicate production of
these products and increase costs for consumers. (Id.) GeoExchange
stated that the timing of the August 2022 NOPR coincides with efforts
by the industry to complete work on its development of a standard that
recognizes the overlap between different applications of heat pump
technology and minimizes unnecessary disruptions for manufacturers.
(Id.)
DOE appreciates these comments regarding the proposal to adopt AHRI
340/360-2022 in the WSHP test procedure. As discussed, in this final
rule, DOE is no longer adopting AHRI 340-360-2022 and is adopting
instead an amended test procedure for WSHPs that incorporates by
reference AHRI 600-2023. Because AHRI 600-2023 was developed through an
industry consensus process subsequent to the timing of the August 2022
NOPR comment period, DOE surmises that the testing approach specified
in AHRI 600-2023 represents the prevailing industry consensus regarding
the most appropriate method of testing WSHPs and addresses the issues
raised by commenters regarding DOE's proposal to adopt AHRI 340/360-
2022 as the test procedure for WSHPs. See sections III.E and III.F of
this final rule for discussion of specific test procedure topics raised
by interested parties in response to the August 2022 NOPR.
Further, in response to the test burden comments, DOE did quantify
per-test burden of the proposed test procedure in the August 2022 NOPR
and found that the proposed test procedure was not unduly burdensome to
conduct. 87 FR 53302, 53340. A similar analysis is presented in this
final rule (see section III.I of this document for details), and the
same conclusion is reached. Additionally, as discussed in this
document, DOE is adopting a test procedure incorporating by reference
the industry consensus test standard, AHRI 600-2023. Therefore, DOE has
determined that the amended test procedure will not increase burden as
compared to the latest draft industry consensus test standard.
5. Comments Encouraging the Adoption of AHRI 600
Numerous commenters encouraged DOE to adopt AHRI 600 in an amended
WSHP test procedure in response to the August 2022 NOPR. AHRI
recommended that DOE refrain from adopting AHRI 340/360-2022 for WSHPs
in favor of continuing to collaborate with industry on finalizing AHRI
600. (AHRI, No. 24 at p. 4) AHRI commented that AHRI 600 has been under
development for several years and that, despite some delays, is
steadily progressing. (Id.) AHRI commented that during the discussions
for the development of AHRI 600, the committee considered applying AHRI
340/360-2022 to calculate IEER. (Id.) AHRI commented that it continues
to improve AHRI 600 test procedures (e.g., by resolving issues to fan
power, external static pressure, water temperature, and subsequent
efficiency levels) and that AHRI will continue committing to frequent
meetings to satisfactorily resolve the issues raised in August 2022
NOPR. (Id.)
WaterFurnace stated that AHRI 600 draft standard was released in
October 2022 and achieves the objectives of the August 2022 NOPR
without industry distractions. (WaterFurnace, No. 20 p. 5) WaterFurnace
commented that AHRI 600 standard is on track for committee review by
October 31, 2023. (Id.)
WaterFurnace stated that the quickest way to implement appropriate
changes to WSHP test procedures would be to adopt versions of AHRI 600
and ISO 13256-1, as modifying test procedures to comply with AHRI 340/
360-2022 would entail substantial changes that will delay the
implementation process. (Id. at p. 4)
WaterFurnace commented that it supports development of AHRI 600
test procedure and recommended that the DOE test procedure reference it
directly instead of AHRI 340/360-2022. (Id. at p. 5) WaterFurnace
stated that the AHRI 600 standard can resolve most of the issues DOE
identified in the August 2022 NOPR regarding the current WSHP test
procedure. (Id.) WaterFurnace recommended that DOE re-evaluate the
August 2022 NOPR proposal and support WaterFurnace's proposal to
quickly adopt AHRI 600 and the national deviation updates to AHRI/ISO
13256. (Id. at p. 11) WaterFurnace commented that doing so will help
industry achieve DOE's desired goals faster and with less disruption.
(Id.)
WaterFurnace commented that it supports implementation of an
updated AHRI/ISO 13256:1998 with a targeted national deviation and
revised annexes. (Id. at p. 5) WaterFurnace commented that an updated
AHRI/ISO 13256:1998 with a targeted national deviation can solve
specific issues mentioned in the August 2022 NOPR regarding AHRI/ISO
13256 with changes that would not be substantial, stating that the
method of testing WaterFurnace follows aligns with the August 2022
NOPR. (Id.) WaterFurnace commented that many of the issues raised by
DOE center on specific issues and test methods currently in use that
can be documented and solved with a national deviation from AHRI/ISO
13256. (Id.) WaterFurnace stated that it has developed a draft of this
national deviation that will address the noted shortcomings and can be
completed in a similar time frame as AHRI 600 approval. (Id.)
ClimateMaster commented that DOE's proposal to move WSHPs to AHRI
340/360-2022 would create too significant a change in the industry and
instead recommended considering AHRI 600, which uses existing ISO/AHRI
13256-1 certified data to mathematically calculate the system IEER.
(ClimateMaster, No. 22 at p. 1) ClimateMaster further commented that
DOE should consider updating the ISO/AHRI 13256-1:1998 standard to
include national deviations to address specific issues such as: (1)
modifying refrigerant charging and airflow/ESP requirements; and (2)
the need to include a reference to ASHRAE 37 and provisions for air
sampling for air-side capacity measurements. (Id. at p. 2)
Enertech suggested adopting AHRI 600 for calculating IEER rather
than the AHRI 340/360-2022 method. (Enertech, No. 19 at p. 2)
MIAQ recommended that DOE work with industry to finalize AHRI
Standard 600, conduct any necessary testing/calculations to develop a
crosswalk, and follow proper procedures to introduce the finalized
procedure and updated
[[Page 84201]]
efficiency standards in ASHRAE 90.1. (MIAQ, No. 23 at p. 9)
Trane recommended that DOE move from a full-load metric and test
procedure to one that is more representative of an energy use cycle,
such as a part-load test procedure. (Trane, No. 28 at p. 3) Trane
commented that the most accurate and representative test procedure is
AHRI 600, not AHRI 340/360-2022 as proposed in the August 2022 NOPR.
(Id.) Trane noted that AHRI 600 draft is now published and seeking
public comments for the final version. (Id. at p. 2)
As discussed, in this final rule, DOE is adopting an amended test
procedure for WSHPs incorporating by reference AHRI 600-2023. As noted
in the previous discussion, the methodology specified in ISO 13256-1
has been incorporated into the AHRI 600-2023, which represents the
latest industry consensus test standard for WSHPs and moves away from
using ISO 13256-1, thus rendering unnecessary a national deviation to
ISO 13256-1. Having been developed through an industry consensus
process subsequent to the timing of the August 2022 NOPR comment
period, DOE surmises that the testing approach specified in AHRI 600-
2023 represents the prevailing industry consensus regarding the most
appropriate method of testing WSHPs.
6. Finalized DOE Test Procedure
In summary, DOE is adopting an amended test procedure for WSHPs
that incorporates by reference AHRI 600-2023, with minor deviations, in
this final rule. DOE has determined that the test methods specified in
AHRI 600-2023 (which are largely consistent with the provisions adopted
in appendix C1 of this final rule) would produce test results that
better reflect energy efficiency of WSHPs during a representative
average use cycle than the current DOE test procedure and ISO 13256-
1:1998. DOE notes that the IEER metric is representative of cooling
efficiency for WSHPs on an annual basis and is more representative than
the current EER metric, which captures the system performance at a
single, full-load operating point. DOE also notes that the other test
procedure amendments incorporated in this final rule better ensure
accurate and repeatable measurements and ensure that representative
test conditions are maintained during testing. These changes include:
(1) Minimum ESP requirements, instructions for setting airflow and
ESP, and tolerances for airflow and ESP;
(2) Operating tolerance for voltage;
(3) Different indoor air conditions for testing;
(4) Refrigerant charging instructions for cases where they are not
provided by the manufacturer;
(5) Use of the primary capacity measurement (i.e., indoor air
enthalpy method) as the value for capacity, and different provisions
for required agreement between primary and secondary capacity
measurements;
(6) Provisions for split systems, such as accounting for compressor
heat and refrigerant line losses;
(7) Measurement of duct losses for ducted units;
(8) Standardized heat capacity of water and brine; and
(9) A calculation for discharge coefficients.
The subsequent sections of this final rule discuss aspects of the
finalized test procedure that differ from the proposal in the August
2022 NOPR. DOE has determined that these updates improve the
representativeness of the test procedure for WSHPs. These include but
are not limited to:
(1) Updated pump power adder, developed during the AHRI 600-2023
process;
(2) ESP requirements for large units >65,000 Btu/h consistent with
levels from the December 2022 term sheet of recommendations regarding
test procedures for air-cooled commercial unitary air conditioners and
heat pumps (``ACUACs and ACUHPs''), referred to hereafter as ``the
ACUAC and ACUHP Working Group TP Term Sheet'' (See Document No. 65 in
Docket No. EERE-2022-BT-STD-0015);
(3) No option to physically test at the IEER conditions and to
instead require testing at all three ISO 13256-1:1998 conditions;
(4) Updated part-load EWT;
(5) Specifying a maximum water flow rate instead of fixed inlet and
outlet water conditions;
(6) Different test provisions for coil-only units, including
adjustments to default fan power;
(7) Different required fluid--a methanol solution--and different
fluid properties specified;
(8) Some changes to airflow provisions, which are consistent with
DOE's test procedure for central air conditioners and heat pumps at
appendix M1 to subpart B of 10 CFR part 430 instead of AHRI 340/360-
2022;
(9) IEER cyclic degradation equation that does not assume
continuous fan operation; and
(10) Heating test temperature of 50 [deg]F instead of 55 [deg]F.
As discussed, DOE recognizes that the test method in AHRI 600-2023
and incorporated by reference into appendix C1 represents an industry
consensus test procedure that is likely to be considered for future
updates to ASHRAE 90.1.
Accordingly, for the foregoing reasons and those discussed in the
subsequent sections of this final rule, DOE is incorporating by
reference AHRI 600-2023 into the amended Federal test procedure for
WSHPs. DOE has determined that the amended test procedure is reasonably
designed to produce results that are representative of the energy
efficiency of that covered equipment during an average use cycle and is
not unduly burdensome to conduct. DOE notes also that use of appendix
C1 will not be required until the compliance date of any amended
standards denominated in terms of IEER, should DOE adopt such
standards.
E. Efficiency Metrics
1. IEER
As discussed previously, DOE's current test procedure for WSHPs
measures cooling-mode performance in terms of the EER metric, the
current regulatory metric. 10 CFR 431.96. EER captures WSHP performance
at a single, full-load operating point in cooling mode (i.e., a single
EWT) and does not provide a seasonal or load-weighted measure of energy
efficiency. A seasonal metric is a weighted average of the performance
of cooling or heating systems at different outdoor conditions intended
to represent average efficiency over a full cooling or heating season.
Several categories of commercial package air-conditioning and heating
equipment are rated using a seasonal or part-load metric, such as IEER.
IEER is a weighted average of efficiency at four load levels
representing 100, 75, 50, and 25 percent of full-load capacity, each
measured at a specified outdoor condition that is representative of
field operation at the given load level. In general, the IEER metric
provides a more representative measure of field performance than EER by
weighting the full-load and part-load efficiencies by the average
amount of time equipment spends operating at each load level. Table 1
of ISO 13256-1:1998, the industry test standard incorporated by
reference into DOE's current WSHP test procedure, and Table 2 of ISO
13256-1:2021 both specify EWT conditions to be used for developing
part-load ratings of EER for WSHPs with capacity control (tested at
minimum compressor speed). However, part-load EER ratings are not
addressed in the current DOE test procedure. Further, each part-load
rating captures operation only at a single compressor speed and EWT
[[Page 84202]]
condition rather than operation across a range of temperatures and
compressor speeds, as would be captured by an IEER metric. Neither ISO
13256-1:1998 nor ISO 13256-1:2021 include seasonal metrics.
In the August 2022 NOPR, DOE tentatively determined that use of a
seasonal efficiency metric would be more representative of the average
use cycle of a unit as compared to the current EER metric. 87 FR 53302,
53313. Accordingly, DOE proposed to adopt certain provisions of AHRI
340/360-2022 and use the IEER metric specified in section 6.2 of AHRI
340/360-2022 for WSHPs. Id. Specifically, DOE proposed that IEER for
WSHPs be calculated based on the EWT conditions specified in Table 9 of
AHRI 340/360-2022 (i.e., 85 [deg]F, 73.5 [deg]F, 62 [deg]F, and 55
[deg]F). Id. DOE referred to the approach of testing at these AHRI 340/
360-2022 EWTs as ``option 1'' in the August 2022 NOPR. Id. at 87 FR
53316.
In addition, DOE acknowledged in the August 2022 NOPR that adopting
the IEER metric for WSHPs would increase the number of required
cooling-mode tests from one to four. Id. at 87 FR 53313. DOE also
discussed its understanding that the future updated version of AHRI 600
would provide for calculating IEER from test results measured at the
EWTs specified in Table 1 of ISO 13256-1:1998. Id. DOE stated that
determining IEER via interpolation and extrapolation from testing at
the ISO 13256-1:1998 EWTs, rather than from additional testing at the
IEER EWTs specified in AHRI 340/360-2022, may reduce overall testing
burden for manufacturers. Id. at 87 FR 53314. Consistent with this
approach, DOE also proposed to allow determination of IEER via
interpolation and extrapolation (``option 2'') based on testing at the
full-load and part-load EWT conditions specified in Table 1 of ISO
13256-1:1998 (i.e., 86 [deg]F, 77 [deg]F, and 59 [deg]F for full-load
tests and 86 [deg]F, 68 [deg]F, and 59 [deg]F for part-load tests). Id.
at 87 FR 53316. DOE proposed that the tests for option 2 would be
performed using the same test provisions (aside from the EWTs) from
AHRI 340/360-2022, ANSI/ASHRAE 37-2009, and sections 2 through 4 and 7
of proposed appendix C1 as the tests for option 1. Id.
In the August 2022 NOPR, DOE presented test data that indicated
that determining EER by interpolating/extrapolating cooling capacity
and total power would result in closer agreement to tested values than
directly interpolating/extrapolating EER. Id. at 87 FR 53314-53315.
Based on these findings, DOE proposed to specify interpolation/
extrapolation using the cooling capacity and total power as opposed to
EER directly. Id. at 87 FR 53316. DOE also presented data in the August
2022 NOPR indicating that for variable-speed WSHPs with higher (i.e.,
better) EER performance at intermediate compressor speeds than at
maximum or minimum compressor speeds, the proposed interpolation and
extrapolation method would result in a lower (i.e., worse) calculated
IEER than testing at the IEER conditions specified in AHRI 340/360-
2022. Id. at 87 FR 53315-53316. DOE discussed its understanding from
participation in AHRI 600 committee meetings that many manufacturers
would prefer the option to use the interpolation and extrapolation
method for variable-speed WSHPs, even if it results in lower IEER
ratings, because it would result in less overall testing burden than
testing at each of the AHRI 340/360-2022 conditions. Id. at 87 FR
53316.
DOE also proposed that if represented values for a basic model are
determined with an AEDM, the AEDM could use either option 1 or option 2
for determining IEER per the proposed test procedure in appendix C1.
Id.
DOE requested comment on the proposal to allow determination of
IEER using two different methods: (1) testing in accordance with AHRI
340/360-2022; or (2) interpolation and extrapolation of cooling
capacity and power values based on testing in accordance with the
proposed test procedure at the EWTs specified in Table 1 of ISO 13256-
1:1998. Id. DOE sought feedback on the proposed method for calculating
IEER via interpolation and extrapolation, and on whether this approach
would serve as a potential burden-reducing option as compared to
testing at the AHRI 340/360-2022 conditions. Id. DOE also requested
comment on whether the proposed methodology to determine IEER based on
interpolation and extrapolation is appropriate for variable-speed
units. Id. DOE noted it would consider requiring variable-speed
equipment be tested only according to AHRI 340/360-2022 and, thus,
testing physically at the IEER EWTs, if suggested by commenters. Id.
Finally, DOE sought feedback on whether the proposed interpolation and
extrapolation method should be based on testing at the ISO 13256-1:2021
EWTs (which differ from the ISO 13256-1:1998 EWTs for certain test
points). Id.
Some commenters opposed DOE's proposals regarding the IEER metric
in the August 2022 NOPR. ClimateMaster, MIAQ, and WaterFurnace
recommended that DOE adopt the test methods specified in AHRI 600
instead of AHRI 340/360-2022 for calculating the IEER of WSHPs.
(ClimateMaster, No. 22 at pp. 3-5; MIAQ, No. 23 at p. 4; Waterfurnace,
No. 20 at pp. 6-7) MIAQ stated that AHRI 600 will provide a method for
calculating a seasonal cooling efficiency metric for WSHPs (i.e., IEER)
based on testing conducted according to ISO 13256-1:1998. (MIAQ, No. 23
at p. 4) MIAQ stated that that the estimated AHRI 600 approval date of
October 1, 2023 would meet DOE's timeline for adopting the standard.
(Id.) ClimateMaster commented that adopting the test methods specified
in AHRI 340/360-2022 would require manufacturers to certify products
under two programs (i.e., AHRI 340-360 and ISO/AHRI 13256), which is
unprecedented in the industry, and would pose challenges for
manufacturers, third-party labs, and partners to test and maintain two
certification programs. (ClimateMaster, No. 22 at p. 3)
ClimateMaster recommended that DOE utilize data created through ISO
13256-1:1998 to interpolate per the procedure provided in AHRI 600.
(ClimateMaster, No. 22 at p. 4) ClimateMaster disagreed with DOE's
proposal for ``option 2'' to interpolate and extrapolate cooling
capacity and total power instead of directly interpolating/
extrapolating EER and argued that the method in the draft AHRI 600 at
the time should be used, which is based on directly interpolating/
extrapolating EER. (Id.) ClimateMaster further argued that the
difference between the two methodologies is within the uncertainty of
measurement for testing WSHPs and, therefore, that DOE's proposed
deviation from the methodology in AHRI 600 (at the time) is
unnecessary. (Id.) ClimateMaster further commented that their analysis
of a random sample of performance data for five systems tested in their
labs showed that, on average, interpolating/extrapolating based on EER
resulted in slightly more accurate numbers than interpolating/
extrapolating based on capacity and power. (Id. at pp. 4-5)
ClimateMaster recommended that DOE maintain the existing ISO 13256-
1:1998 standard until the WSHP industry adopts the updated standard and
suggested that DOE adopting a national deviation of ISO 13256-1:2021
would be practical as long manufacturers are given significant time to
adopt the new test procedure. (ClimateMaster, No. 22 at p. 5)
ClimateMaster commented that there are several changes introduced in
ISO 13256-1:2021 that it believes provide a more effective performance
map for a
[[Page 84203]]
WSHP system, but that this standard has not yet been adopted by the
WSHP industry. (Id.) ClimateMaster further commented that the EWTs
utilized for determining IEER via interpolation/extrapolation are
irrelevant as long as DOE requires that the entering air temperatures
and other items are inconsistent from the current ISO 13256-1:1998 test
program. (Id.)
Regarding DOE's request for comment on variable-speed unit testing,
ClimateMaster commented that DOE's test results from the units sampled
and tested at a third-party lab should be shared with stakeholders for
review and comment--particularly regarding variable speed units, as
most of these require hardware and software from the manufacturer to
allow for proper testing, and test instructions were not provided to
DOE for the department's testing of variable-speed units as would be
done for normal certification testing. (ClimateMaster, No. 22 at p. 4)
MIAQ commented that the proposed interpolation and extrapolation
method should be based on testing at the ISO 13256-1:2021 EWTs. (MIAQ,
NO. 23 at p. 4) Regarding the proposed ``option 2'' approach for
determining IEER via interpolation/extrapolation for variable-speed
units, MIAQ recommended DOE use the latest edition of ISO 13256-1:2021
as the test procedure and continue to use AHRI 340/360-2022 for IEER
calculations. (Id.)
Other commenters supported DOE's proposals regarding the IEER
metric in the August 2022 NOPR. The Joint Commenters supported adopting
a part-load metric to measure cooling efficiency performance, stating
that WSHPs, like many other commercial air conditioners and heat pumps,
operate a significant percent of the time at part-load conditions, and
that a part-load metric could incentivize designs that reduce annual
energy consumption. (Joint Commenters, No. 27 at pp. 1-2) The Joint
Commenters recommended DOE ensure that an adopted part-load metric
reflects the total cooling provided divided by the total energy
consumed and noted that they have previously commented that the IEER
metric likely does not reflect the total cooling provided divided by
the total energy consumed, and instead weights efficiencies calculated
at different load-points. (Id.)
NEEA supported DOE's proposed transition from regulating WSHP
efficiency based on a full-load EER metric to a multi-capacity IEER
metric. (NEEA, No. 25 at p. 2) NEEA commented that an IEER metric is
more representative of overall equipment performance, and that
optimizing part-load efficiencies is beneficial to both consumers and
utilities because heating/cooling equipment operates at peak capacity
for a small number of hours. (Id.) NEEA recommended that DOE move to
the IEER metric for regulatory purposes while still encouraging
manufacturers to also publish full-load EER data, given the importance
of EER data for peak load performance and planning for utilities. (Id.)
NEEA commented that it is encouraged by DOE's monitoring of the
development of the AHRI Standard 600 and stated that this standard will
allow for even more representative ratings of regional seasonal heating
and cooling efficiencies. (Id.)
NYSERDA supported DOE's proposal to adopt for WSHPs the testing
methods specified in AHRI 340/360-2022 for calculating IEER, stating
that a seasonal efficiency metric is more representative of the part-
load operation and varying temperature conditions seen in actual field
performance of WSHPs. (NYSERDA, No. 21 at p. 2)
As discussed in section III.D, DOE is incorporating by reference
AHRI 600-2023 into its amended WSHP test procedure. Section 6.3 of AHRI
600-2023 uses a method for determining IEER that is similar to the
interpolation method proposed in the August 2022 NOPR, including tests
at three EWTs, interpolating from those EWTs to the IEER EWTs specified
in AHRI 340/360-2022, and adjusting the efficiency from the tested and
interpolated load percentages to the IEER load percentages.
With regards to ClimateMaster's comment on the interpolation
methodology (i.e., interpolating the capacity and power vs.
interpolating EER directly), DOE discussed this issue with stakeholders
in AHRI 600 meetings after publication of the August 2022 NOPR, and
section 6.3.4 of AHRI 600-2023 includes interpolation of capacity and
power, consistent with the approach proposed in the August 2022
NOPR.\7\ Having been developed through an industry consensus process
subsequent to the timing of the August 2022 NOPR comment period, DOE
surmises that the interpolation approach specified in AHRI 600-2023
represents the prevailing industry consensus regarding the most
appropriate method of performing the interpolation of capacity and
power and addresses the issues raised by commenters regarding DOE's
proposed methodology for the interpolation method in the August 2022
NOPR.
---------------------------------------------------------------------------
\7\ As discussed later in this section, the lowest EWT in AHRI
600-2023 is 50 [deg]F, which is lower than the lowest IEER EWT (55
[deg]F), such that the AHRI 600-2023 approach does not require
extrapolation for determining IEER.
---------------------------------------------------------------------------
With regards to the comment from the Joint Commenters recommending
that DOE adopt a part-load metric that reflects the total cooling
provided divided by the total energy consumed, DOE notes that no
industry test procedures for WSHPs include a metric using such an
equation format instead of the equation format for IEER (which is a
weighted average of EERs at four different EWTs) and the Joint
Commenters did not provide sufficient information to support
development of such an equation format for WSHPs. Therefore, at this
time, DOE has concluded that it lacks the necessary information to
adopt an integrated metric other than IEER for WSHPs.
While much of the methodology to determine IEER adopted in this
final rule is consistent technically with the proposal from the August
2022 NOPR, DOE notes the following differences between the approach
adopted in this final rule (consistent with AHRI 600-2023) and the
proposals in the August 2022 NOPR:
(1) Removal of option for testing directly at IEER EWTs. In this
final rule, DOE is not adopting the proposed option 1 methodology of
directly testing at the IEER EWTs (i.e., 85 [deg]F, 73.5 [deg]F, 62
[deg]F, 55 [deg]F). Rather, consistent with section 6.3 of AHRI 600-
2023, the test procedure adopted in this final rule specifies that IEER
is determined via interpolation from tests at ISO 13256-1 EWTs, which
is similar to option 2 as proposed in the August 2022 NOPR. With
regards to NYSERDA's comment supporting adopting AHRI 340/360-2022 to
calculate IEER, DOE notes that the methodology specified in AHRI 600-
2023 is very similar and produces near identical results to the
methodology of AHRI 340/360-2022, as demonstrated through DOE's data
presented in the August 2022 NOPR. See 87 FR 53302, 53316.
(2) Change in full-load test EWTs. The full-load test temperatures
used for interpolation in section 6.2.1 of AHRI 600-2023 are consistent
with ISO 13256-1:2021 (i.e., 86 [deg]F, 68 [deg]F, 50 [deg]F) instead
of ISO 13256-1:1998 (i.e., 86 [deg]F, 77 [deg]F, 59 [deg]F), which was
proposed in the August 2022 NOPR. This is also consistent with the
comment from MIAQ that encouraged the use of ISO 13256-1:2021 EWTs.
(3) Change in part-load test EWTs. The part-load test EWTs used for
interpolation in section 6.3.2 of AHRI 600-2023 are the same as the
full-load EWTs (i.e., 86 [deg]F, 68 [deg]F, 50 [deg]F). This differs
from the approach in the August 2022 NOPR, which proposed to align
[[Page 84204]]
with the EWTs specified in ISO 13256-1:1998 (i.e., 86 [deg]F, 77
[deg]F, and 59 [deg]F for full-load tests; 86 [deg]F, 68 [deg]F, and 59
[deg]F for part-load tests). MIAQ encouraged the use of ISO 13256-
1:2021, which specifies part-load test EWTs of 77 [deg]F, 59 [deg]F,
and 41 [deg]F. The part-load EWTs in section 6.3.2 of AHRI 600-2023 (86
[deg]F, 68 [deg]F, 50 [deg]F) are not consistent with either the 1998
or 2021 versions of ISO 13256-1, and instead reflect the conclusion of
discussions in AHRI 600 committee meetings that conducting part-load
tests at the same EWTs as full-load tests would reduce testing burden
(by reducing the number of times the water temperature would need to be
reconditioned between tests) and better align with the IEER methodology
in AHRI 340/360-2022. DOE surmises that the part-load EWTs specified in
section 6.3.2 of AHRI 600-2023 represent the prevailing industry
consensus regarding the most appropriate EWTs for testing WSHPs. In
addition, as compared to the part-load EWTs proposed in the August 2022
NOPR (the lowest of which was 59 [deg]F), the lowest part-load EWT in
AHRI 600-2023 (50 [deg]F) is lower than the lowest IEER EWT (55
[deg]F). Therefore, use of the part-load EWTs in AHRI 600-2023 means
that all IEER EWTs can be interpolated from the tested EWTs, instead of
requiring any extrapolation. As a result, in this final rule DOE is
adopting the part-load EWTs as outlined in the AHRI 600-2023 through
incorporation by reference.
(4) Updated provisions for variable speed units. The approach for
determining IEER for variable-speed WSHPs specified in AHRI 600-2023
differs from the approach proposed in the August 2022 NOPR in that
additional tests are required at intermediate compressor speeds.
Specifically, section 6.3.2 of AHRI 600-2023 requires that three tests
be performed at each EWT, at the three following compressor speeds: (1)
maximum compressor speed (i.e., full-load test); (2) minimum compressor
speed; and (3) an intermediate compressor speed that reflects the
compressor stage with a capacity closest to half-way between the
capacities measured at the minimum and maximum compressor speeds. This
third test reduces the range of compressor speeds over which
interpolation must be conducted (i.e., interpolating between
intermediate compressor speed and maximum or minimum compressor speeds,
instead of between maximum compressor speed and minimum compressor
speed), thus reducing the extent to which interpolated results might
differ from unit performance at the IEER EWTs. DOE surmises that the
approach for variable speed units specified in section 6.3.2 of AHRI
600-2023 represents the prevailing industry consensus regarding the
most appropriate method. Therefore, in this final rule, DOE is adopting
the IEER determination method for variable-speed units from AHRI 600-
2023 through incorporation by reference into appendix C1 of section
6.3.2. Additionally, DOE presumes this updated methodology resolves
Climatemaster's request for DOE's variable speed test data, as DOE is
adopting the industry consensus methodology.\8\
---------------------------------------------------------------------------
\8\ Section 6.3.2.4 of AHRI 600-2023 further specifies that if
the continuous capacities of two compressor modulation levels
allowed by the controls at a single set of operating conditions are
equidistant from the arithmetic mean of the capacities from the
minimum and maximum compressor modulation levels at the same set of
operating conditions, the intermediate compressor modulation level
used for testing is the compressor modulation level with the lower
capacity.
---------------------------------------------------------------------------
(5) Change in cyclic degradation equation. See section III.E.1.a of
this document for detailed discussion.
Finally, DOE is defining ``IEER'' in 10 CFR 431.92 as a weighted
average calculation of mechanical cooling EERs determined for four load
levels and corresponding rating conditions, expressed in Btu/watt-hour
and that IEER is measured per appendix C1 to subpart F of part 431 for
water-source heat pumps.
a. Cyclic Degradation
In the August 2022 NOPR, DOE proposed to adopt specific sections of
AHRI 340/360-2022 in its amended test procedure for WSHPs, including
section 6.2.3.2. 87 FR 53302, 53327. Equation 4 in section 6.2.3.2 of
AHRI 340/360-2022 is used to calculate part-load EER for a unit that
needs to cycle in order to meet the 75-percent, 50-percent, and/or 25-
percent load conditions required for the IEER metric. Id. Cycling is
the term used to describe the process in which a unit's compressor is
repeatedly turned off and on in order to meet a load that is lower than
the unit's capacity at its lowest compressor stage. Id. Equation 4 of
AHRI 340/360-2022 multiplies only the compressor power and condenser
section power by the load factor and the coefficient of degradation,
while the indoor fan power and controls power are not multiplied by
these variables. Id. This means that equation 4 of AHRI 340/360-2022
assumes that the indoor fan continues to operate when the compressor
cycles off. Id.
DOE requested comment on the proposal to adopt the cyclic
degradation equation specified in section 6.2.3.2 of AHRI 340/360-2022
for WSHPs, which assumes continuous indoor fan operation when the
compressor cycles off. Id. at 87 FR 53328.
ClimateMaster commented that the assumption of continuous fan
operation in the AHRI 340/360 IEER calculations is neither
representative of field operation nor is it in alignment with guidance
provided by ASHRAE 90.1. (ClimateMaster, No. 22 at p. 3) ClimateMaster
stated that, according to data it collected through consumer surveys,
16 percent of installed systems cycle fan operation with the
compressor, 52 percent operate the fan continuously while a building is
occupied but cycle the fan with the compressor when unoccupied, and
only 14 percent of installed WSHPs run the fan continuously regardless
of occupancy and compressor operation, while the remaining 18 percent
responded that they were unaware of how their WSHP system cycles
operated. (Id. at p. 3) ClimateMaster recommended that DOE instead use
AHRI 600 method that does not assume continuous fan operation. (Id. at
p. 8) ClimateMaster commented that, for WSHPs that are installed to
operate the fan continuously, models with a multi-speed motor will
operate at the cooling fan speed, while variable-speed models have an
option to adjust the continuous fan speed to a lower value. (Id.)
WaterFurnace commented that supporting ISO 13256 and AHRI 600 would
solve the issue. (WaterFurnace, No. 20 at p. 8) WaterFurnace stated
that continuous indoor fan operation is not the most appropriate logic
in cooling-dominated environments and recommended demand controls
ventilation as a better use of energy that improves latent moisture
removal. (Id.)
In response to these comments, DOE notes that section 6.3.6.4 of
AHRI 600-2023 has an equation similar to equation 4 of AHRI 340/360-
2022, but the equation in AHRI 600-2023 assumes that the indoor fan
stops operating whenever the compressor cycles off. The data provided
by ClimateMaster suggest that the vast majority of installed WSHPs do
not operate the fan continuously in all operating modes, but that many
installed WSHPs do operate the fan continuously during occupied hours
(i.e., regardless of whether the compressor is cycled on or off). At
the time of publication of the August 2022 NOPR, there were no WSHP
industry consensus test procedures that included IEER. However, at this
time, DOE surmises that the method in section 6.3.6.4 of AHRI 600-2023,
which assumes the fan does not run when the compressor is cycled off,
represents
[[Page 84205]]
industry consensus on the appropriate method for determining IEER for
WSHPs. At this time, DOE has concluded that it lacks sufficient
information to justify deviating from the approach in AHRI 600-2023
regarding fan operation. DOE is therefore incorporated by reference the
cyclic degradation equation from section 6.3.6.4 of AHRI 600-2023 into
its amended test procedure in this final rule.
2. ACOP
DOE's current test procedure for WSHPs measures heating-mode
performance in terms of the COP metric. COP is a full-load heating
efficiency metric for WSHP water-loop applications, meaning that it
represents the heating efficiency for a WSHP operating at its maximum
capacity at an EWT that is typical of heating operation in water-loop
applications. DOE's current test procedure specifies an EWT of 68
[deg]F for measuring COP. 10 CFR 431.96.
In the August 2022 NOPR, DOE discussed its understanding that while
in the past water-loop temperatures were maintained at temperatures
above 60 [deg]F via heat provided by a system boiler, in current
practice WSHP installations are typically controlled to allow water-
loop temperatures to drop to temperatures closer to 50 [deg]F. 87 FR
53302, 53316. Therefore, while the current EWT of 68 [deg]F for the COP
metric may have been more representative of how WSHP systems were
controlled in the past (i.e., with a boiler maintaining water-loop
temperatures above 60 [deg]F), DOE tentatively determined in the August
2022 NOPR that the EWT specified for determining COP should be no
higher than the lowest EWT used in the IEER metric, which is 55 [deg]F
(for the 25-percent load point). Id. Therefore, DOE tentatively
concluded in the August 2022 NOPR that the COP metric would be more
representative of water-loop WSHP applications if based on an EWT of 55
[deg]F. Id. at 87 FR 53317. Accordingly, in the August 2022 NOPR, DOE
proposed use an EWT of 55 [deg]F for the COP metric in appendix C1. Id.
DOE also considered whether an EWT below 55 [deg]F, specifically 50
[deg]F, might be more representative for determining COP, depending
upon typical heating conditions for water-loop WSHPs. Id. However, DOE
noted in the August 2022 NOPR that it lacked data or evidence
indicating that 50 [deg]F would be a more representative heating EWT
than 55 [deg]F for WSHPs. Id.
Additionally, DOE proposed to include an alternate method in
appendix C1 that would allow manufacturers to determine COP at the
proposed EWT of 55 [deg]F by interpolation from results of testing at
the EWTs specified in Table 2 of ISO 13256-1:1998 (i.e., 50 [deg]F and
68 [deg]F). Id. In the August 2022 NOPR, DOE presented the results of
investigative testing demonstrating that COP calculated from
interpolated values of cooling capacity and total power differed from
measured COP by an average of less than 1 percent. Id. Based on these
test results, DOE tentatively concluded that determining COP at 55
[deg]F via interpolation from testing at the ISO 13256-1:1998 EWTs (in
accordance with DOE's proposed test procedure) would provide
appropriately representative results that are comparable to testing at
55 [deg]F. Id.
In summary, DOE proposed in section 6.2 of the proposed appendix C1
to allow that COP for WSHPs can be calculated from either of two
methods: (1) ``option A''--testing at 55 [deg]F; or (2) ``option B''--
interpolation of heating capacity and power values based on testing in
accordance with the proposed test procedure at EWTs of 50 [deg]F and 68
[deg]F. Id.
DOE sought comment and data on the representativeness of 55 [deg]F
as the EWT condition for determining COP. Id. Specifically, DOE
requested feedback and data on whether a lower EWT, such as 50 [deg]F,
would be more representative of heating operation of WSHPs. Id. DOE
stated that it would further consider any alternate EWT suggested by
comments in developing any final rule. Id. DOE also requested comment
on the proposal to allow determination of COP using the two different
methods. Id. Specifically, DOE sought feedback on the proposed method
for calculating COP via interpolation and on whether this approach
would serve as a potential burden reducing option as compared to
testing at 55 [deg]F. Id.
In response to the August 2022 NOPR, ClimateMaster recommended that
DOE maintain use of the ISO 13256-1:1998 EWT of 68 [deg]F as the basis
for the regulated metric, asserting that this would take into account
the fact that building designers select and simulate system equipment
and performance based upon data published by manufacturers.
(ClimateMaster, No. 22 at p. 5) ClimateMaster stated that the EWT used
for heating operation in a WSHP is dependent on many factors (e.g.,
building design, location, system design, system operation, and
building occupancy or use) and that, due to these factors, there are no
data available to determine the representativeness of 55 [deg]F as the
EWT condition in contrast to a lower or higher EWT. (Id.)
Regarding DOE's proposal to allow two different options for
determining COP, ClimateMaster stated that it disagreed with both
proposed options for allowing determination of COP, stating that
neither option would provide a reduction in burden considering DOE's
proposal to change entering air temperatures. (Id.) ClimateMaster
further commented that the proposed changes would require the industry
to test under multiple standards to meet both certification programs.
(Id. at pp. 5-6)
MIAQ recommended aligning the EWT conditions with the latest
edition of ISO standard EWT conditions. (MIAQ, No. 23 at p. 4)
WaterFurnace commented that non-expansion valve products typically
cannot operate below an EWT of 60 [deg]F and that a percentage of the
market has always had limited water temperature range capability.
(WaterFurnace, No. 20 at p. 7) WaterFurnace also commented that
adopting ISO 13256-1 and AHRI 600 would solve the issue of COP test
temperature. (Id.)
Regarding considerations for selecting the EWT condition for
determining COP, FHP commented that the use of higher EWTs is focused
on water loop condition only and the move to electrification for
commercial buildings will shift commercial designs for water source
products toward ground coupled systems, driving temperatures closer to
ISO 13256-1 ground loops conditions (e.g., 32 [deg]F entering water).
(FHP, No. 26 at p. 4)
NYSERDA agreed with DOE's proposal to adopt an EWT of 55 [deg]F or
lower, stating that geothermal technology research and development
undertaken by NYSERDA and the Cleaner, Greener Communities Program in
Syracuse revealed the average EWT for the average mixed-use building
was 48 [deg]F when heating. (NYSERDA, No. 21 at p. 3) NYSERDA commented
that it had collected data supporting that the average building
consistently uses EWTs of 55 [deg]F or lower and presented these data
in a table that suggested the current EWT test condition of 68 [deg]F
is unrepresentatively high. (Id. at pp. 3-4)
In response to WaterFurnace's comment that some products cannot
operate below 60 [deg]F, DOE notes that the heating temperatures in
section 6.2.1 of AHRI 600-2023 include temperatures below 60 [deg]F, at
50 [deg]F and 32 [deg]F. Inclusion of these EWTs in the updated
industry standard suggests that there is industry agreement that WSHPs
can generally operate below 60 [deg]F. DOE is not aware of any WSHPs
that cannot operate in heating mode at 50 [deg]F and notes that the
issue was not raised in
[[Page 84206]]
AHRI 600 committee meetings after the August 2022 NOPR. As discussed
earlier in this section, comments from other interested parties also
supported the use of a lower temperature.
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023. Section 6.2.1 of AHRI 600-
2023 includes EWTs of 68 [deg]F, 50 [deg]F, and 32 [deg]F for measuring
COP. Additionally included in section 6.4.5 of AHRI 600-2023 is a new
metric, ACOP, which is only measured at 50 [deg]F. This new metric is
similar to COP but includes provisions accounting for system pump
power, which better accounts for total energy use of WSHPs and aligns
with changes made to the cooling efficiency metric (see section III.F.3
of this document for more details). Further, ACOP is included in
section 7.1 of AHRI 600-2023 as a minimum requirement for published
ratings. Therefore, ACOP, measured at 50 [deg]F, is the heating metric
required for WSHPs according to AHRI 600-2023. Having been developed
through an industry consensus process subsequent to the timing of the
August 2022 NOPR comment period, DOE surmises that ACOP tested at an
EWT of 50 [deg]F specified in AHRI 600-2023 represents the prevailing
industry consensus regarding the most appropriate metric for measuring
heating performance. Therefore, in this final rule, DOE is
incorporating by reference sections 6.2.1 and 6.4.5 of AHRI 600-2023
into appendix C1 adopting the ACOP metric, tested at an EWT of 50
[deg]F.
DOE notes that no heating EWT of 55 [deg]F is included in section
6.2.1 of AHRI 600-2023 and, instead, Table 8 of the document maintains
the same heating test temperatures as ISO 13256-1:1998 (68 [deg]F, 50
[deg]F, and 32 [deg]F). Therefore, due to the lack of support of a test
temperature at 55 [deg]F, the exclusion of that temperature in AHRI
600-2023, and the support for aligning with ISO 13256-1:1998 test
temperatures (which include 50 [deg]F), DOE is finalizing the ACOP
metric based on a test at 50 [deg]F, consistent with AHRI 600-2023.
As discussed, use of the amended test procedure in appendix C1 and
rating to ACOP at 50 [deg]F are not required until the compliance date
of amended standards denominated in terms of ACOP, should DOE adopt
such standards. DOE is defining ``ACOP'' in 10 CFR 431.92 as the ratio
of the heating capacity to the power input, including system pump
power, for water-source heat pumps and that ACOP is expressed in watts
per watt and determined according to appendix C1 of subpart F of part
431.
Because AHRI 600-2023 requires a heating test at 50 [deg]F, there
is no need for an interpolation method to determine ACOP at an EWT
different from the tested EWT, and, therefore, AHRI 600-2023 includes
no such interpolation method for ACOP. Correspondingly, because DOE is
incorporating by reference AHRI 600-2023 into appendix C1 to require a
heating test be conducted at 50 [deg]F and to adopt the ACOP metric
based on the same EWT, the COP interpolation method proposed in the
August 2022 NOPR is no longer applicable. Therefore, DOE is not
adopting an interpolation method for determining ACOP in this final
rule.
3. Optional Representations
In the August 2022 NOPR, DOE proposed provisions to allow for
optional representations of EER conducted per the proposed test
procedure (sections 2 through 4 and 7 of proposed appendix C1) at the
full-load and part-load EWT conditions specified in Table 1 of ISO
13256-1:1998 (i.e., full load tests at 86 [deg]F, 77 [deg]F, and 59
[deg]F and part-load tests at 86 [deg]F, 68 [deg]F, and 59 [deg]F). 87
FR 53302, 53314. Additionally, DOE proposed provisions to provide for
optional representations of COP based on testing conducted per the
proposed test procedure (sections 2 through 4 and 7 of proposed
appendix C1) at the full-load and part-load EWT conditions specified in
Table 2 of ISO 13256-1:1998 (i.e., 68 [deg]F, 50 [deg]F, 41 [deg]F, and
32 [deg]F). Id. at 87 FR 53317.
AHRI 600-2023 includes provisions allowing for optional
representations of EER and COP in sections 6.3.12 and 6.4.7,
respectively. Optional representations can be made at any of the
cooling and heating full-load and part-load EWT conditions in Table 8
of AHRI 600-2023. DOE notes that the AHRI 600-2023 includes new metrics
applied energy efficiency ratio (``AEER'') and ACOP (see section
III.E.2 of this final rule for more details about ACOP). Each of these
metrics include a power adder representing system pumps and the adder
for AEER also includes cooling tower power. DOE notes that AHRI 600-
2023 does not have provisions for optional representations of these
metrics and instead requires them to be published. The optional
representations of EER and COP allowed for by AHRI 600-2023 do not
include the power adder for system pumps and cooling tower power.
As discussed in section III.E.1 and III.E.2 of this final rule, DOE
is incorporating by reference AHRI 600-2023 for IEER and ACOP into
appendix C1 as the cooling and heating metrics for WSHPs. The IEER
metric as determined according to AHRI 600-2023 includes a power adder
for system pumps and cooling tower power. DOE notes that the metrics it
is adopting are intended to best reflect WSHP performance, using
representative EWTs and including power for all components that are
needed for operation of WSHP systems in a representative application
(i.e., external pumps and cooling towers). Optional representations of
EER and COP are intended to provide more information to consumers
across a range of temperature conditions such that performance can be
assessed for specific applications. DOE is adopting the provisions for
optional representations of EER and COP from sections 6.3.12 and 6.4.7
from AHRI 600-2023 by incorporating by reference AHRI 600-2023 into
appendix C1. These provisions allow optional representations to be made
consistent with AHRI 600-2023 at full-load or part-load at any of the
standard rating conditions for WSHPs (i.e., 86 [deg]F, 68 [deg]F, and
50 [deg]F for cooling and 68 [deg]F, 50 [deg]F, and 32 [deg]F for
heating). DOE notes that these temperatures vary slightly from the
proposals in the August 2022 NOPR for optional representations, but
represent the same intent of allowing for optional representations of a
range of operating conditions. Having been developed through an
industry consensus process subsequent to the timing of the August 2022
NOPR comment period, DOE has determined that the EWTs specified in AHRI
600-2023 represent the prevailing industry consensus regarding the most
appropriate EWTs for optional performance test points.
4. Entering Air Conditions
The current DOE WSHP test procedure references ISO 13256-1:1998,
which specifies in Table 1 that EER is measured with entering air at 27
[deg]C (80.6 [deg]F) dry-bulb temperature and 19 [deg]C (66.2 [deg]F)
wet-bulb temperature and in Table 2 that COP is measured with entering
air at 20 [deg]C (68 [deg]F) dry-bulb temperature and 15 [deg]C (59
[deg]F) wet-bulb temperature.
In the August 2022 NOPR, DOE proposed to use the entering air
conditions in Table 6 of AHRI 340/360-2022, which specify that cooling
tests are measured with entering air at 80 [deg]F dry-bulb temperature
and 67 [deg]F wet-bulb temperature heating tests are measured with
entering air at 70 [deg]F dry-bulb temperature and a maximum of 60
[deg]F wet-bulb temperature. 87 FR 53302, 53318. DOE discussed in the
August 2022 NOPR that the entering air conditions specified in AHRI
340/360-2022 are similar to the conditions specified in ISO 13256-
1:1998 and ISO 13256-1:2021, differing for cooling by
[[Page 84207]]
0.6 [deg]F for dry-bulb temperature and 0.8 [deg]F for wet-bulb
temperature and for heating by 2 [deg]F for dry-bulb temperature and 1
[deg]F for wet-bulb temperature. Id. DOE surmised that these
differences are likely due to the conditions in ISO 13256-1 (1998 and
2021 versions) being specified in terms of degrees Celsius, whereas the
conditions in AHRI 340/360-2022 are specified in degrees Fahrenheit.
Id. DOE also noted that the entering air conditions specified in AHRI
340/360-2022 are the same as in previous versions of AHRI 340/360,
including AHRI 340/360-2007, which is referenced in the current DOE
test procedure for CUAC/HP equipment. Id. Further, the most common
application for WSHPs (and the application DOE understands that the
WSHP industry is intending to represent via use of the IEER metric in
AHRI 600) is commercial buildings, similar to CUAC/HP equipment. Id.
Therefore, DOE tentatively determined in the August 2022 NOPR that the
entering air conditions in AHRI 340/360-2022 are appropriately
representative of the average conditions in which WSHPs operate in the
field. Id.
DOE requested comment on its proposal to specify use of the cooling
entering air conditions from AHRI 340/360-2022 (i.e., 80 [deg]F dry-
bulb temperature and 67 [deg]F wet-bulb temperature) and the heating
entering air conditions from AHRI 340/360-2022 (i.e., 70 [deg]F dry-
bulb temperature and a maximum of 60 [deg]F wet-bulb temperature). Id.
In response to the August 2022 NOPR, ClimateMaster recommended that
DOE keep the existing entering air temperature conditions for both
heating and cooling tests from ISO 13256-1:1998 to avoid the
requirement to test equipment under two separate certification
programs. (ClimateMaster, No. 22 at p. 6) ClimateMaster stated that the
use of 80.6 [deg]F and 66.2 [deg]F entering air conditions for cooling
would be more conservative (i.e., result in lower efficiency ratings)
than those at 80 [deg]F and 67 [deg]F as specified in AHRI 340/360-
2022. (Id.)
WaterFurnace commented that adopting ISO 13256 and AHRI 600 would
solve the issue of which entering air conditions to use. (WaterFurnace,
No. 20 at p. 7) WaterFurnace further commented that DOE's proposal
would essentially require all new testing due to the different entering
air conditions. (Id.) WaterFurnace stated that the existing entering
air conditions of AHRI/ISO 13256 could be used and would result in a
more conservative performance prediction. (Id.)
MIAQ commented that it generally agrees with DOE's proposal to
adopt the entering air conditions in AHRI 340/360-2022. (MIAQ, No. 23
at p. 5)
As discussed, DOE is adopting provisions for determining IEER and
ACOP by incorporating by reference AHRI 600-2023 into appendix C1. The
entering air conditions in section 6.2.1 of AHRI 600-2023 align with
the entering air conditions specified in AHRI 340/360-2022 (and
therefore align with DOE's August 2022 NOPR proposal). DOE surmises
that inclusion of the AHRI 340/360-2022 entering air conditions in AHRI
600-2023 indicates industry consensus with these test conditions.
Therefore, DOE is adopting provisions for determining IEER and ACOP
consistent with AHRI 600-2023, including entering air conditions of 80
[deg]F dry bulb and 67 [deg]F wet bulb for cooling tests and 70 [deg]F
dry bulb and a maximum of 60 [deg]F wet bulb for heating tests, in this
final rule, by incorporating by reference into appendix C1 section
6.2.1 of AHRI 600-2023.
F. Test Method
1. Airflow and External Static Pressure
a. Fan Power Adjustment and Required Air External Static Pressures
For ducted units, the current DOE WSHP test procedure, which
incorporates by reference ISO 13256-1:1998, specifies a fan power
adjustment calculation that does not account for fan power used for
overcoming external resistance. As a result, the calculation of
efficiency includes only the fan power required to overcome the
internal resistance of the unit. In addition, ISO 13256-1:1998 does not
specify ESP requirements for ducted equipment, instead allowing
manufacturers to specify a rated ESP. In the August 2022 NOPR, DOE
proposed provisions to reflect fan power to overcome a representative
ESP when calculating efficiency for ducted units to account for the
impacts of ESP typically encountered in the field. 87 FR 53302, 53321.
DOE determined that, to best reflect field operation, ducted WSHPs
should be tested with minimum ESPs, the power for overcoming ESP should
be included in efficiency calculations, and all equipment should be
tested with an ESP upper tolerance. Id. DOE determined that the method
in AHRI 340/360-2022 is more representative of field energy use than
the methods used in ISO 13256-1:1998 for WSHPs. Id. DOE proposed to
adopt AHRI 340/360-2022 for WSHPs, including section 6.1.3.3 and Table
7 of AHRI 340/360-2022, which specify minimum ESPs for ducted units, a
tolerance on ESP of -0.00/+0.05 in H2O, and no fan power
adjustment. Id. DOE requested comment on the proposal to adopt
provisions from AHRI 340/360-2022 such that for ducted units testing
would be conducted within tolerance of the AHRI 340/360-2022 minimum
ESP requirements, and efficiency ratings would include the fan power
measured to overcome the tested ESP. Id. at 87 FR 53322.
In response to the August 2022 NOPR, ClimateMaster recommended that
DOE keep the existing ISO 13256-1:1998 standard and develop an IEER
rating per AHRI 600 that offers provisions for complying with the
required minimum external pressure as given in AHRI 340/360-2022.
(ClimateMaster, No. 22 at p. 6) ClimateMaster stated that there are
multiple reasons why the current ISO 13256-1:1998 standard excludes
external static pressure, including that the methodology was created to
rate different motor options for varying static requirements in the
market space, which is especially problematic with non-variable speed
motors as they are limited in output capability over a narrow static
range. (Id.) MIAQ recommended DOE reference the ESP requirements in the
latest edition of ISO 13256-1. (MIAQ, No. 23 at p. 5) WaterFurnace
commented that supporting ISO 13256 and AHRI 600 would solve the issue
and that it believes the required information can be calculated from
AHRI/ISO 13256 data without retesting. (WaterFurnace, No. 20 at p. 7)
WaterFurnace additionally commented that the minimum ESP requirements
specified in AHRI 340/360 are adequate for most commercial WSHPs
because most are installed with common plenum returns with little to no
return ductwork. (Id.)
FHP recommended that instead of requiring testing at minimum ESP
requirements, DOE develop a revised fan power adjustment that
incorporates accurate fan efficiencies and allows testing at a range of
ESPs but adjusts fan performance to reflect performance at the minimum
ESPs specified in AHRI 340/360-2022. (FHP, No. 26 at pp. 3-4) FHP
asserted that such a revised fan power adjustment would allow for
variations in tested ESP to achieve rated airflow to account for
limitations of the fan-motor combination and variation in manufacturing
tolerances, while still ensuring ratings are based on an ESP more
representative than zero ESP. (Id.)
The Joint Commenters supported DOE's proposal that WSHPs be tested
at the ESPs specified in the proposed test procedure. (Joint
Commenters, No. 27 at p. 2) The Joint Commenters stated that
maintaining the current test procedure,
[[Page 84208]]
which applies a correction factor that adjusts fan power measured at
the manufacturer-specified ESP is adjusted down to reflect fan power at
zero ESP and incentivizes testing with higher-than-representative ESPs,
would be inconsistent with the recommendation in the ASRAC Fans and
Blowers Working Group term sheet to capture fan energy more fully
across commercial HVAC product categories. (Id.)
NEEA supported DOE's proposal to include additional fan energy in
the WSHP efficiency metric, but also encouraged DOE to consider
increasing the proposed ESP requirements to be more representative of
current industry practice. (NEEA, No. 25 at pp. 2-3) NEEA stated that
during the 2015 CUAC/HP energy conservation standard ASRAC
negotiations, DOE's energy use analysis used ESP values 2 to 3 times
higher than the ESP requirements in the current test procedure because
DOE found the values to be more realistic and representative of field
conditions. (Id. at p. 3) NEEA further recommended that DOE consider
aligning WSHP ESP requirements with the updated CUAC/HP ESP
requirements when they are finalized by the ASRAC Working Group. (Id.)
With regards to these comments, DOE notes that section 5.5.1 of
AHRI 600-2023 includes ESPs to be used for testing for ducted units.
The ESPs are equivalent to those outlined in AHRI 340/360-2022 for
units less than 75,000 Btu/h cooling capacity, but the ESPs for units
above 75,000 Btu/h cooling capacity (i.e., 0.75 in. H2O for
units from 75,000 Btu/h to 134,000 Btu/h; 1.00 in. H2O for
units from 135,000 Btu/h to 280,000 Btu/h; and 1.50 in. H2O
for units greater than 280,000 Btu/h) are significantly higher than
those in AHRI 340/360-2022 and align with the ESP requirements
recommended in the ACUAC and ACUHP Working Group TP Term Sheet. (See
Document No. 65 in Docket No. EERE-2022-BT-STD-0015) Section 5.7 of
AHRI 600-2023 also includes a tolerance of ESP of -0.00/+0.05 in
H2O and sections 6.3 and 6.4 of AHRI 600-2023 include no fan
power adjustment. DOE notes also that the approach set forth in AHRI
600-2023 is mostly consistent with the approach proposed in the August
2022 NOPR, with the only difference being higher ESP requirements for
units greater than 75,000 Btu/h in cooling capacity. DOE has determined
that the inclusion of ESP requirements, an ESP tolerance, and no fan
power adjustment in AHRI 600-2023 represents industry consensus that
these provisions provide the most appropriate and representative method
for testing WSHPs. As discussed in section III.D of this final rule,
DOE is incorporating by reference AHRI 600-2023 into appendix C1,
including these ESP provisions. DOE notes that including these
provisions is consistent with commenters' suggestions to adopt AHRI
600.
Regarding the higher ESP requirements for units with a cooling
capacity greater than 75,000 Btu/h, adopting these values is consistent
with NEEA's recommendation to align with the recommendations from the
ASRAC Working Group for test procedures for CUAC/HPs. These ESP
requirements were developed as part of a joint effort between
manufacturers, efficiency advocates, utilities, and DOE to create a
more representative efficiency metric for CUACs/HPs. DOE understands
that WSHPs greater than 75,000 Btu/h are installed in similar
applications to CUACs/HPs and, as such, DOE finds the AHRI 600-2023 ESP
requirements to be representative for WSHPs with a cooling capacity
greater than 75,000 Btu/h.
DOE notes that the ACUAC and ACUHP Working Group TP Term Sheet
recommends an ESP requirement of 0.75 in. H2O for units with
a cooling capacity between 65,000 to 135,000 Btu/h, while the lower
capacity limit for this requirement in section 5.5.1 of AHRI 600-2023
is 75,000 Btu/h. Based on discussions in AHRI 600 committee meetings,
DOE understands that there are WSHP model lines that span up to 6 tons
that typically use fan/motor combinations that are designed for lower
ESP applications and cannot operate at the rated airflow at an ESP as
high as 0.75 in. H2O. Therefore, AHRI 600-2023 specifies a
lower capacity limit for this ESP requirement of 75,000 Btu/h rather
than 65,000 Btu/h so that these 6-ton models are tested with a more
representative ESP. DOE understands this issue to be unique to WSHPs
and does not apply to ACUACs and ACUHPs, for which models with a
cooling capacity between 65,000 Btu/h and 75,000 Btu/h typically have
different designs than three-phase ACUACs and ACUHPs (which typically
have comparable designs to CAC/HPs) and are typically designed for
installations for which an ESP of 0.75 in. H2O is
representative. Therefore, in this final rule, DOE is incorporating by
reference the requirements specified in Table 7 of section 5.5.1 of
AHRI 600-2023 for all WSHPs with a cooling capacity less than 760,000
Btu/h.
With regard to comments from ClimateMaster and FHP expressing
concern over ability of different fan/motor combinations to test at an
ESP requirement at the rated airflow, DOE notes that this issue is
addressed by the provisions for (1) non-standard high-static indoor fan
motors and fan/motor combinations proposed in the August 2022 NOPR,
included in section D4 of AHRI 600-2023 (discussed in section III.G.3
of this final rule); and (2) non-standard low-static motors included in
sections 3.2.30 and 5.7.4.3 of AHRI 600-2023 (discussed in section
III.F.12 of this final rule). DOE has concluded that the inclusion of
ESP requirements and provisions in AHRI 600-2023 for (1) non-standard
high-static indoor fan motors and fan/motor combinations and (2) non-
standard low-static motors reflect industry consensus that these
provisions provide an appropriate method for testing and rating WSHPs.
DOE notes that section 5.5.1.2 of AHRI 600-2023 specifies a minimum
ESP of 0.5 in. H2O for residential representations, but that
the residential representations have not yet been fully developed for
WSHPs (see section III.A.2 of this document for more details). DOE will
continue to work with AHRI 600 committee to develop provisions for
determining such ratings.
b. Setting Airflow and ESP
DOE's current WSHP test procedure does not include provisions on
how to simultaneously set airflow and ESP because there are no required
ESPs for testing. Because DOE proposed to include minimum ESPs in its
test procedure in the August 2022 NOPR, it also proposed provisions to
address how to simultaneously set airflow and ESP. 87 FR 53302, 53322-
53324. The proposals were broken into three groups:
(1) For ducted units with continuously variable speed fans, DOE
proposed to use relevant provisions from AHRI 340/360-2022 in sections
6.1.3.3 through 6.1.3.5.
(2) For ducted units with discrete step fans, DOE proposed
instructions for setting the fan speed in the scenario in which: (1)
tolerances for airflow and ESP could not be met simultaneously, and (2)
adjacent fan control settings result in airflow or ESP too low at the
lower fan control setting and too high at the higher fan control
setting.
(3) For non-ducted units, DOE proposed units to be tested with a
target ESP of 0.00 in H2O within a tolerance of -0.00/+0.05
in H2O.
Id.
For all three types of units, the proposed airflow tolerance was 3
percent. Id.
DOE requested comment on the proposed adoption of provisions from
AHRI 340/360-2022 for setting airflow and ESP for testing WSHP units
with
[[Page 84209]]
continuously variable speed fans. Id. at 87 FR 53323. DOE also
requested comment on its proposed instructions (distinct from
provisions in AHRI 340/360-2022) for setting airflow and ESP for ducted
WSHP units with discrete-step fans. Id. Finally, DOE requested comment
on its proposal for setting airflow and ESP for non-ducted WSHP units.
Id. at 87 FR 53324.
In response to the August 2022 NOPR, ClimateMaster recommended that
DOE work with industry to create a national deviation of ISO 13256-
1:1998 that adopts the applicable parts of AHRI 340/360 for fully
variable-speed motor systems and systems with adjustable sheaves, while
still providing separate provisions for setting airflow for fan motor
systems that are not continuously variable. (ClimateMaster, No. 22 at
p. 7) ClimateMaster stated that it disagrees with the use of AHRI 340/
360-2022 for all indoor blower systems, arguing that these provisions
were developed to accommodate only continuously variable-speed blower
systems and asserted that the proposed 3 percent tolerance would not be
feasible for larger WSHP systems without continuously variable motors
or WSHPs with discrete-step or constant volume fan motors. (Id. at p.
6) ClimateMaster stated that Table B1 of the AHRI WSHP Operations
Manual \9\ specifies a 5 percent airflow tolerance for discrete-step
motors. (Id. at p. 7) ClimateMaster further commented that the
provisions for setting airflow in AHRI 210/240-2023 are more
appropriate for the fan motors utilized in most WSHP systems (i.e., not
continuously variable), stating that the AHRI 210/240-2023 provisions
use manufacturer-specified fan motor settings and allow airflow to
decrease to 10 percent below the target airflow. (Id. at p. 7)
---------------------------------------------------------------------------
\9\ DOE notes that the AHRI WSHP Certification Operations Manual
is available at: https://www.ahrinet.org/sites/default/files/2022-06/WSHP_OM.pdf (Last accessed April 25, 2023).
---------------------------------------------------------------------------
FHP commented that the combination of a minimum ESP requirement and
a 3 percent airflow tolerance would require additional testing and
significant design constraints and changes at the component level for
WSHPs with direct-drive motors and questioned whether a 3 percent
airflow tolerance at a minimum ESP requirement is technologically
feasible. (FHP, No. 26 at p. 4) FHP further commented that units with
constant-torque direct-drive fan motors (e.g., permanent split
capacitor (``PSC'') motors, electrically commutated motors (``ECMs''))
do not allow for adjustments to airflow without adjustments to ESP,
making it difficult to consistently hit the airflow target within 3
percent. (Id.) FHP also noted that the AHRI WSHP Operations Manual
allows for adjustments to ESP to meet a 5-percent airflow tolerance for
these systems. (Id.)
WaterFurnace commented that adopting ISO 13256 and AHRI 600 would
solve the issue. (WaterFurnace, No. 20 at p. 8) WaterFurnace stated
that a test procedure for models fans with ECMs would have to be added
to AHRI 340/360 because the standard does not address setting airflow
and ESP for such models, which it stated are typical for smaller WSHPs.
(Id.) MIAQ recommended DOE reference the latest edition of ISO 13256-1,
stating that this standard is the industry test procedure currently
used by manufacturers and laboratories for WSHP testing. (MIAQ, No. 23
at p. 5)
ClimateMaster stated that the WSHP Operations Manual covers
available provisions with what they consider to be a proper allowance
for airflow variation and that non-ducted WSHPs are available with
motors that have multiple set speeds either through software or by
utilizing a tapped motor winding. (ClimateMaster, No. 22 at p. 7)
ClimateMaster stated that these provisions are slightly different from
those proposed in the August 2022 NOPR and requested further
clarification to the meaning of ``as close as possible''. (Id.)
ClimateMaster noted that they expect that the speed tap specified by
the manufacturer would be utilized and that, if this is the case, then
there should not be any concern if the airflow is ``as close as
possible'' to the rated point. (Id.)
In response to the comment from ClimateMaster, DOE notes that the
``as close to the target as possible'' language in the August 2022 NOPR
is used in situations when the airflow and ESP requirements cannot be
simultaneously met. Specifically, for non-ducted units, the August 2022
NOPR provisions specify that if airflow and ESP requirements cannot be
met simultaneously, the ESP requirement takes precedence (i.e., ESP
must be maintained within tolerance) and the airflow is maintained as
close as possible to the target airflow (but outside of tolerance).
Section 5.8 of AHRI 600-2023 similarly specifies that in this situation
the ESP must be maintained within tolerance and that there is no
condition tolerance for airflow.
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes sections 5.7 and 5.8 of AHRI 600-2023. This language includes
provisions generally consistent with provisions outlined in the August
2022 NOPR, specifically a tolerance of 3 percent for setting airflow,
separate provisions for continuously variable speed fans and discrete-
step fans, and a method for non-ducted units. Section 5.7 of AHRI 600-
2023 also includes provisions for setting airflow and ESP for constant-
volume fans, but DOE notes that these provisions were not proposed in
the August 2022 NOPR and are consistent with provisions in appendix M1
for central air conditioners and heat pumps.
Regarding commenter's concerns about models with non-continuously-
variable fan motors, the comments received suggest that the commenters
interpreted DOE's proposal to be adopting the provisions for setting
airflow and ESP in AHRI 340/360-2022 without modification. However, as
discussed in the August 2022 NOPR, DOE proposed additional provisions
to allow a larger airflow tolerance for models with non-continuously-
variable fan motors that align more closely with the provisions for
setting airflow in AHRI 210/240-2023 (as recommended by ClimateMaster).
See 87 FR 53302, 53323. Similar provisions are included in AHRI 600-
2023. DOE has concluded that these provisions, along with the
previously mentioned provisions for constant-volume fans, provide an
appropriate method for setting airflow and ESP for WSHPs of all fan
motor types.
DOE has determined that incorporating by reference AHRI 600-2023
for setting airflow and ESP addresses commenters' concerns. DOE
surmises that the inclusion of these provisions for setting airflow and
ESP in AHRI 600-2023 indicates industry consensus that these provisions
provide an appropriate method for testing WSHPs. Therefore, in this
final rule, DOE is incorporating by reference into appendix C1 sections
5.7 and 5.8 of AHRI 600-2023 for setting airflow and ESP.
c. Coil-Only Units
For units without integral fans (i.e., coil-only units), section
4.1.3.1 of ISO 13256-1:1998, which is referenced in the current DOE
WSHP test procedure, specifies that a fan power adjustment be added to
the total power of the unit, and that this value be added to the
heating capacity and subtracted from the cooling capacity. The fan
power adjustment equation to determine fan power estimates fan power to
overcome internal pressure drop within the unit, using a similar
methodology to the fan power adjustment equation used for
[[Page 84210]]
units with integral fans to subtract out the fan power to overcome ESP.
As discussed in section III.F.1.a of this final rule, the amended test
procedure adopted in appendix C1 (incorporating by reference AHRI 600-
2023) does not use a fan power adjustment for units with integral fans
and requires testing at representative minimum external static
pressures and ratings reflect performance at the tested ESP.
As part of DOE's proposal to adopt AHRI 340/360-2022, in the August
2022 NOPR, DOE proposed to adopt sections 6.1.1.6, 6.1.3.3 and 6.1.3.4
of AHRI 340/360-2022, which contain provisions for how to test coil-
only units. 87 FR 53302, 53322. In particular, section 6.1.3.3.4
specifies that coil-only units shall not have a pressure drop exceeding
0.30 in H2O for the full load cooling test. Section
6.1.3.4.6 outlines that coil-only units are to be tested at
manufacturer specified airflow rates, not exceeding 450 standard cubic
feet per minute (``scfm'') per ton of cooling capacity and if there is
no manufacturer specified airflow rate, they are to be tested at 400
scfm per ton of rated cooling capacity. Finally, section 6.1.1.6
specifies that 1,250 Btu/h per 1,000 scfm is to be removed from the
measured cooling capacity and 365 Watts (``W'') per 1,000 scfm is to be
added to the measured power for ducted coil-only units.
AHRI 600-2023 includes provisions for coil-only units, which are
defined as units without an indoor fan or separate designated air
mover. The provisions are nearly identical to those proposed in the
August 2022 NOPR. Section 5.5.2 specifies that coil-only units shall
not have a pressure drop exceeding 0.30 in H2O for the full-
load cooling test. Section 5.6.3 outlines that coil-only units are to
be tested at manufacturer specified airflow rates, not exceeding 450
scfm per ton of cooling capacity and if there is no manufacturer
specified airflow rate, they are to be tested at 400 scfm per ton of
rated cooling capacity. Finally, sections 6.3.3.4 and 6.4.3.4 specify
that for ducted coil-only units, measured capacity is adjusted by 1,245
Btu/h per 1,000 scfm (subtracted from cooling capacity and added to
heating capacity) and measured power is adjusted by adding 365 W per
1,000 scfm. Additionally, AHRI 600-2023 includes provisions for non-
ducted coil only units--for these, the values are 940 Btu/h per 1,000
scfm for capacity adjustment and 275 W per 1,000 scfm for power adder
respectively.
DOE notes that the provisions outlined in AHRI 600-2023 are
consistent with those proposed in the August 2022 NOPR except for a
minor deviation in the capacity reduction for ducted coil-only units
and the inclusion of provisions for non-ducted coil-only units. Based
on discussion in AHRI 600 committee meetings, DOE understands that non-
ducted coil-only WSHP models exist on the market, and therefore, DOE
has determined that the addition of provisions for testing such units
is warranted. As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes section 5.5.2, 5.6.3, and 6.3.3.4 of AHRI 600-2023. DOE notes
the inclusion of these provisions in AHRI 600-2023 indicates industry
consensus with these provisions and provides an appropriate method for
testing coil-only WSHPs. Therefore, DOE is incorporating by reference
into appendix C1 the provisions for coil-only units from AHRI 600-2023
in this final rule.
2. Capacity Measurement
The current DOE WSHP test procedure, through adoption of section
6.1 of ISO 13256-1:1998, specifies that total cooling and heating
capacities are to be determined by averaging the results obtained using
two test methods: the liquid enthalpy test method for the liquid side
tests and the indoor air enthalpy test method for the air side tests.
10 CFR 431.96. For non-ducted equipment, section 6.1 of ISO 13256-
1:1998 includes an option for conducting the air-side tests using the
calorimeter room test method instead of the air enthalpy test method.
Section 6.1 of ISO 13256-1:1998 also specifies that, for a test to be
valid, the results obtained by the two methods used must agree within 5
percent. ANSI/ASHRAE 37-2009 is similar to the test method in ISO
13256-1:1998. ANSI/ASHRAE 37-2009 requires two capacity measurements
for units with cooling capacity less than 135,000 Btu/h; the first
method of measurement (i.e., the primary method) is used as the
determination of the unit's capacity, while the second measurement
(i.e., the secondary method) is used to confirm rather than to be
averaged with the primary measurement (see section 10.1 and Table 1 of
ANSI/ASHRAE 37-2009).
In the August 2022 NOPR, DOE proposed to adopt specific sections of
AHRI 340/360-2022 for use in the WSHP test procedure, including section
E6, which specifies test methods for capacity measurement. 87 FR 53302,
53325-53327. Section E6.1 of AHRI 340/360-2022 requires use of the
indoor air enthalpy method specified in section 7.3 of ANSI/ASHRAE 37-
2009 as the primary method for capacity measurement. This is the
measurement used to determine capacity, as required in section 10.1.2
of ANSI/ASHRAE 37-2009. Section E6.2.2 of AHRI 340/360-2022 requires
use of one of the applicable ``Group B'' methods specified in Table 1
of ANSI/ASHRAE 37-2009 as a secondary method for capacity measurement.
The group B methods that are applicable to WSHPs are the outdoor liquid
coil method (similar to the liquid enthalpy method included in the 1998
and 2021 versions of ISO 13256-1), the refrigerant enthalpy method, and
the compressor calibration method. Section E6.4.2 of AHRI 340/360-2022
requires that the primary and secondary measurements match for full-
load cooling and heating tests, within 6 percent of the primary
measurement. No match is required between primary and secondary
measurements for part-load cooling tests. DOE proposed to adopt all of
these provisions by incorporating by reference AHRI 340/360-2022. Id.
at 87 FR 53325. DOE requested comment on this approach to adopt the
provisions in AHRI 340/360-2022 and ANSI/ASHRAE 37-2009 regarding
primary and secondary capacity measurements. Id. at 87 FR 53326.
In response to the August 2022 NOPR, ClimateMaster commented that
it agrees with the intent of DOE's proposed approach but disagrees with
some specifics and recommended that DOE work with industry to create a
national deviation of ISO 13256-1:1998 that adopts the provisions of
ANSI/ASHRAE 37-2009 for primary and secondary capacity measurements,
with certain modifications. (ClimateMaster, No. 22 at pp. 7-8)
ClimateMaster commented additionally that it disagrees with the
provisions in AHRI 340/360-2022 that only require agreement between the
primary and secondary capacity measurements for full-load tests. (Id.
at p. 8) ClimateMaster noted that the current ISO standard allows for a
5 percent tolerance between the two measurements, and that in its
internal testing ClimateMaster strives for agreement within 3-4
percent, stating that anything over that limit indicates an issue in
equipment setup and/or the measurement system. (Id.) ClimateMaster
commented that neglecting to include a match requirement for part-load
tests could lead to inaccurate representations of system performance.
(Id.)
ClimateMaster further commented that the uncertainty of measurement
for the liquid coil method is lower than for the indoor air enthalpy
method, and that the WSHP industry considers the liquid coil method to
be the more accurate measurement method. (Id.) ClimateMaster also
stated that the liquid coil method does not include the
[[Page 84211]]
limitations regarding refrigerant sub-cooling that are specified for
the refrigerant enthalpy method (in section 7.5.1.3 of ANSI/ASHRAE 37-
2009), and stated that low values of refrigerant subcooling are
typically seen in part-load tests. (Id.) ClimateMaster commented that
it disagrees with section 7.6.1.2 of ANSI/ASHRAE 37-2009 because this
provision specifies that the outdoor liquid coil method cannot be used
for outdoor compressor systems, and therefore makes the refrigerant
enthalpy method necessary as the secondary capacity measurement method
for such systems. (Id.) ClimateMaster stated that while it agrees in
theory that the compressor and associated refrigerant lines will lose
heat when an uninsulated compressor section is installed outdoors,
requiring the use of the refrigerant enthalpy method is not
representative of installed outdoor compressor systems because for
testing the outdoor section of a split WSHP system is installed in the
same psychrometric room as the indoor air handler. (Id.) ClimateMaster
added that there are currently no specified outdoor conditions or
requirements for placement of the outdoor unit in a differently
conditioned room and that the difference between the current liquid
coil method and the proposed refrigerant enthalpy method is negligible
without specifying conditions more thoroughly. (Id.) ClimateMaster
further commented that the insulation requirements in ANSI/ASHRAE 37-
2009 only specify 1 inch of fiberglass insulation and do not specify a
minimum R-value for the insulation. (Id.)
In summary, ClimateMaster recommended that DOE adopt the indoor air
enthalpy method for the primary capacity measurement, and that the
outdoor coil liquid method be used for the secondary capacity
measurement if the unit either (1) meets the requirements of section
7.6.1.2 of ANSI/ASHRAE 37-2009 using fiberglass insulation or an
equivalent material with an R-value of 8.0, or (2) is an outdoor unit
installed in the same test chamber as the indoor coil. (Id.)
ClimateMaster further recommended a requirement for agreement within 5
percent between primary and secondary capacity measurements for full-
load and part-load tests. (Id.)
MIAQ commented that DOE's proposed approach in the August 2022 NOPR
of adopting the provisions in AHRI 340/360 and ANSI/ASHRAE 37-2009
regarding primary and secondary capacity measurements deviates from the
industry test procedure ISO 13256-1 and therefore will require
manufactures to retest their products, resulting in increased burden.
(MIAQ, No. 23 at p. 6)
WaterFurnace commented that adopting ISO 13256 and AHRI 600 would
solve the issue and that the liquid enthalpy test method is widely
accepted as the most accurate method for capacity measurement for
WSHPs. (WaterFurnace, No. 20 at p. 8)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into Appendix C1, including
provisions in Section 5.2 of AHRI 600-2023 regarding primary and
secondary capacity measurement methods. Specifically, Section 5.2
states that the indoor air enthalpy method be used as the primary
measurement of capacity, and that secondary capacity measurements be
conducting using one of the following methods: outdoor liquid coil
method, refrigerant enthalpy method, or compressor calibration method.
Section 5.2.2 of AHRI 600-2023 also states that, when using the outdoor
liquid coil method, the secondary measurement must agree within 6
percent of the primary measurement of capacity on all tests, including
part-load tests. Incorporating by reference this language addresses
comments in response to the August 2022 NOPR that DOE should adopt AHRI
600. The provisions in AHRI 600-2023 also address ClimateMaster's
concerns about not having a match for part-load tests because AHRI 600-
2023 does require a match between primary and secondary capacity
measurements for part-load tests if the outdoor liquid coil method is
used.
Regarding agreement between primary and secondary measurements, DOE
has concluded that the requirement in AHRI 600-2023 that secondary
capacity measurements agree within 6 percent of primary capacity
measurements (consistent with AHRI 340/360-2022, which DOE proposed to
reference in the August 2022 NOPR) provides a representative measure of
efficiency for WSHPs.
Regarding ClimateMaster's concerns about the outdoor liquid coil
method provisions in ANSI/ASHRAE 37-2009, DOE notes that section
5.2.2.1.1 of AHRI 600-2023 specifies to follow all requirements in
section 7.6 of ANSI/ASHRAE 37-2009 when using the outdoor liquid coil
method and does not include any provisions that deviate from ANSI/
ASHRAE 37-2009 with regard to outdoor compressor systems or insulation
R-value. Regarding ClimateMaster's concern that ANSI/ASHRAE 37-2009
requires use of the refrigerant enthalpy method for secondary capacity
measurements for systems in which the compressor is located outdoors,
DOE further notes that for a split system WSHP with the compressor and
liquid coil contained in the outdoor unit intended for outdoor
installation, shell losses from the compressor could impact capacity
measurements using the outdoor liquid coil method but would not impact
capacity measurements using the refrigerant enthalpy method. Therefore,
at this time, DOE does not have sufficient evidence or justification to
deviate from the provisions in AHRI 600-2023 regarding the outdoor
liquid coil method and has concluded that these provisions provide for
appropriate and representative measurements of efficiency for WSHPs.
Additionally, AHRI 600-2023 was developed through an industry
consensus process subsequent to the timing of the August 2022 NOPR
comment period, and DOE surmises that the capacity measurement approach
specified in section 5.2 of AHRI 600-2023 sufficiently addresses the
concerns raised in comments to the August 2022 NOPR. Consequently, DOE
is incorporating by reference into appendix C1 section 5.2 of AHRI 600-
2023 regarding primary and secondary capacity measurements in this
final rule.
3. Pump Power Adjustment and Liquid External Static Pressure
ISO 13256-1:1998 does not reflect the pump power needed to overcome
liquid ESP from the water loop that pipes water to and from the WSHP.
Instead, section 4.1.4 of ISO 13256-1:1998 includes a pump power
adjustment (which assumes a pump efficiency of 0.3 for all units) to be
applied such that only the pump power required to overcome the liquid
internal static pressure of the unit is included in calculation of
efficiency ratings. ISO 13256-1:1998 also does not specify any liquid
ESP requirements for testing. The exclusion of pump power to overcome
ESP from system water loop piping in ISO 13256-1:1998 ratings results
in higher efficiency ratings than would be measured if ratings
reflected pump power to overcome ESP. ISO 13256-1:1998 also does not
specify a minimum liquid ESP during testing for units with integral
pumps. For units without integral pumps, the pump power adjustment in
ISO 13256-1:1998 estimates pump power at zero liquid external static
pressure.
As discussed previously, ISO 13256-1:1998 was updated. However, the
pump power and liquid ESP provisions in sections 5.1.4 and 5.1.6 of ISO
[[Page 84212]]
13256-1:2021 are the same as those in sections 4.1.4 and 4.1.6 of ISO
13256-1:1998.
In the August 2022 NOPR, DOE proposed to adopt provisions for WSHPs
in appendix C1 that align with the recently adopted provisions for
water-source dedicated outdoor air systems (``DOASes''). 87 FR 53302,
53328-53329. The proposed provisions would require that all WSHPs with
an integral pump be tested with a liquid ESP of 20 ft of water column,
with a -0/+1 ft condition tolerance and a 1 ft operating tolerance. Id.
at 87 FR 53328. For units without integral pumps, DOE proposed to
require that a ``total pumping effect'' (calculated using the same
equation as in section 6.1.6.4 of AHRI 920-2020) be added to the unit's
measured power to account for the pump power to overcome the internal
static pressure of the unit and a liquid ESP of 20 ft of water column.
Id. at 87 FR 53328-53329. Further, DOE proposed to require that the
measured pump power or the pump effect addition, as applicable, be
included in the condenser section power for units of all capacities
when performing cyclic degradation during calculation of IEER. Id. at
87 FR 53329. DOE requested commented on the proposed provisions to
account for pump power to overcome both internal pressure drop and a
representative level of liquid ESP for WSHPs with and without integral
pumps. Id. DOE specifically requested comment on the representativeness
of 20 ft of water column as the liquid ESP for WSHPs. Id.
In response to the August 20222 NOPR, ClimateMaster disagreed with
DOE's proposed values for the liquid ESP for WSHPs, arguing that the
pumping and cooling tower fan power adder specified in AHRI 920-2020 is
incorrect. (ClimateMaster, No. 22 at p. 8) ClimateMaster commented
that, according to a 2014 study conducted by S. Kavanaugh and K.
Rafferty, pumping power for a closed loop ground-source heat pump
(``GSHP'') system can reach 3.75 W/kBtu/h but not exceed 10 W/1kBtu/h,
and that the values given in AHRI 920 are much higher than these values
and are thus not representative of an installed system. (Id. at pp. 8-
9) ClimateMaster recommended that DOE use the approach in AHRI 600,
which includes pumping power for the internal pressure drop and adds a
representative value for building pump and cooling tower operation.
(Id. at p. 9) ClimateMaster commented that this AHRI 600 power adder
for building pump and cooling tower energy consumption is based on the
results of an analysis conducted of typical closed loop systems during
the development of the AHRI 600 standard, which resulted in calculated
power adders of 5.5 W/kBtu/h for full-load conditions and 1 W/kBtu/h
for part-load conditions. (Id.)
FHP commented that the work done by the AHRI 600 working group took
a more accurate approach to today's systems that allows for varying the
fans and pumping energy required during part-load conditions. (FHP, No.
26 at p. 5) FHP recommended that DOE review the values assigned to
tower/pump penalty in AHRI 600 for guidance on this topic, stating that
a single-head pressure as a means of estimating the pumping penalty
does not allow for the variations expected at part-load conditions.
(Id.) WaterFurnace commented that adopting ISO 13256 and AHRI 600 would
solve the issue, noting that the pump power is accounted for in AHRI
600. (WaterFurnace, No. 20 at p.8)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. AHRI 600-
2023 includes provisions to separately account for pump power to
overcome liquid internal and external static pressure.
Sections 6.3.3 and 6.4.3 of AHRI 600-2023 specify to include pump
power to overcome the liquid internal static pressure of the WSHP in
all cooling and heating ratings. The calculation for pump power
adjustment to account for liquid internal static pressure uses a
similar methodology to ISO 13256-1:1998, but uses a higher pump
efficiency of 75% (as compared to 30% in ISO 13256-1:1998) to better
represent the efficiency of system pumps in commercial water-loop
installations. Specifically, for units without integral pumps, the AHRI
600-2023 approach adds pump power to overcome liquid internal static
pressure. For units with integral pumps, section 5.4.13 of AHRI 600-
2023 specifies a liquid ESP value of zero to use when testing WSHPs
with an integral pump for commercial ratings and specifies to test at
the minimum liquid ESP if the minimum is higher than zero ESP. In the
case of testing a unit with an integral pump at a liquid ESP above
zero, sections 6.3.3 and 6.4.3 of AHRI 600-2023 specify to subtract
pump power to overcome liquid ESP using a similar methodology to the
approach for calculating pump power adjustment for units without
integral pumps.
Sections 6.3.7 (for IEER), 6.3.11 (for AEER), and 6.4.4 (for ACOP)
of AHRI 600-2023 specify to include power to account for power required
for a system pump to overcome liquid ESP representative of a commercial
water-loop installations. As discussed in section III.E.3 of this final
rule, AHRI 600-2023 specifies these provisions to account for system
pump power for calculation of AEER, IEER, and ACOP, but not for
optional representations of EER and COP.
The provisions for accounting for pump power (to overcome liquid
internal and external static pressure) were developed in AHRI 600
committee meetings after publication of the August 2022 NOPR. While the
AHRI 600-2023 approach is not the same as that proposed in the August
2022 NOPR in that it uses a different calculation method and assumes a
different liquid ESP, it is consistent with the August 2022 NOPR
proposal to include power to represent power consumed by pumps to
overcome both liquid internal and external static pressure. The AHRI
600-2023 pump power adders are different than those suggested by
ClimateMaster. However, having been developed through an industry
consensus process subsequent to the timing of the August 2022 NOPR
comment period, DOE surmises that the pump power approach specified in
AHRI 600-2023 represents the prevailing industry consensus regarding
the most appropriate method for addressing pump power. Further, DOE has
concluded based on discussion in AHRI 600 committee meetings that the
AHRI 600-2023 pump power approach is representative of typical water-
loop WSHP applications. As a result, in this final rule, DOE is
incorporating by reference into appendix C1 the methods specified in
AHRI 600-2023 for accounting for pump power.
DOE notes that section 5.4.13.2 of AHRI 600-2023 specifies a
minimum liquid ESP of 7.0 psi for residential representations. However,
the residential representations have not yet been fully developed for
WSHPs (see section III.A.2 of this document for more details). DOE will
continue to work with the AHRI 600 committee to develop provisions for
determining such ratings.
4. Test Liquid and Specific Heat Capacity
The current DOE WSHP test procedure, through adoption of section
4.1.9 of ISO 13256-1:1998, requires the test liquid for water-loop heat
pumps and ground-water heat pumps to be water, and the test liquid for
ground-loop heat pumps to be a 15 percent solution by mass of sodium
chloride in water (i.e., brine). 10 CFR 431.96. Further, the liquid
enthalpy test method in Annex C of ISO 13256-1:1998, which is included
in the current DOE WSHP test procedure, requires the use of the
[[Page 84213]]
specific heat capacity of the test liquid for calculating cooling and
heating capacity but does not specify a value or method for calculating
the specific heat capacity.
Section 5.1.7 of ISO 13256-1:2021 requires that the test liquid for
the low temperature heating test (i.e., EWT of 32 [deg]F) must be a
brine of the manufacturer's specification, while the test liquid for
all other tests may be water or a brine of a composition and
concentration specified by the manufacturer. ISO 13256-1:2021 does not
specify a value or method for calculating the specific heat capacity of
any test liquids.
In the August 2022 NOPR, DOE proposed in section 4.1 of proposed
appendix C1 that the test liquid for all tests other than the proposed
optional ``HFL3'' \10\ low temperature heating test (i.e., EWT of 32
[deg]F) must be water, unless the manufacturer specifies to use a brine
of 15-percent solution by mass of sodium chloride in water. 87 FR
53302, 53329. DOE also proposed in section 4.1 of proposed appendix C1
that the test liquid for the optional HFL3 low temperature heating test
must be a brine of 15-percent solution by mass of sodium chloride in
water. Id. Ground-loop applications of WSHPs typically use brine in the
liquid loop because, in cold weather, the liquid temperature can reach
32 [deg]F (i.e., the temperature at which water freezes) in places. A
15-percent solution by mass of sodium chloride in water can withstand
temperatures as low as 14 [deg]F before freezing. Allowing the use of
brine for testing would provide manufacturers the flexibility of
providing ratings more representative of ground-loop applications.
Therefore, DOE proposed to require brine as the liquid for the optional
HFL3 low temperature heating test (conducted with an EWT of 32 [deg]F),
consistent with section 4.1.9 of ISO 13256-1:1998 and section 5.1.7 of
ISO 13256-1:2021, to avoid the liquid freezing during the test. Id.
---------------------------------------------------------------------------
\10\ ``HFL3'' is the nomenclature used to define the 32 [deg]F
full-load heating test that DOE proposed to add in appendix C1.
---------------------------------------------------------------------------
In the August 2022 NOPR, DOE tentatively concluded that a 15-
percent solution by mass of sodium chloride, as specified in section
4.1.9.2 of ISO 13256-1:1998, is a representative brine composition and
concentration for applications needing brine (e.g., ground-loop), and
that consumers can make more representative comparisons between models
when all models are rated with the same brine composition and
concentration. Id.
As discussed in section III.D.2 of the August 2022 NOPR, DOE
proposed to adopt specific sections of AHRI 340/360-2022 in its test
procedure for WSHPs. Id. AHRI 340/360-2022 in turn references the test
method in ANSI/ASHRAE 37-2009, in which section 12.2.1 requires that
thermodynamic properties of liquids be obtained from the ASHRAE
Handbook--Fundamentals.\11\ The ASHRAE Handbook--Fundamentals specifies
specific heat capacity values for water and for a brine of 15 percent
solution by mass of sodium chloride at multiple temperatures. The
absence of provisions in ISO 13256-1:1998 for how to determine specific
heat capacity for test liquids creates the potential for variation in
measured values based on how specific heat capacity is determined.
Therefore, to minimize any such variation, DOE instead proposed in the
August 2022 NOPR to adopt relevant provisions of ANSI/ASHRAE 37-2009.
Id. DOE tentatively determined that the specifications in ANSI/ASHRAE
37-2009 would be appropriate for testing WSHPs because they are the
generally accepted industry method used for testing similar equipment,
such as WCUACs. Id.
---------------------------------------------------------------------------
\11\ The ASHRAE Handbook--Fundamentals is available at: https://www.ashrae.org/technical-resources/ashrae-handbook.
---------------------------------------------------------------------------
In the August 2022 NOPR, DOE requested comment on the proposed
requirements for using water or a brine of 15-percent solution by mass
of sodium chloride as the test liquid. Id. DOE also requested comment
on the representativeness and test burden associated with permitting
the use of different liquids for different tests. Id. Finally, DOE
requested comments on the proposal to utilize the thermodynamic
properties specified in ANSI/ASHRAE 37-2009 through DOE's proposed
incorporation by reference of AHRI 340/360-2022. Id.
In response to the August 2022 NOPR, MIAQ commented that sodium
chloride is not a common anti-freeze and that propylene and ethylene
glycol are more common. (MIAQ No. 23 at p. 6) MIAQ commented that it is
unsure if nationally recognized testing laboratories \12\ are equipped
to deal with 15-percent solution by mass of sodium chloride as the test
liquid. (Id.) MIAQ stated that specifying a particular antifreeze
rather than relevant thermal properties for the test fluid hinders
innovation and generates a heavy burden to develop and test with the
specified medium. (Id.) MIAQ argued that specifying sodium chloride as
the test liquid may require redesign of the units to avoid corrosion.
(Id.)
---------------------------------------------------------------------------
\12\ MIAQ used the abbreviation NRL, but DOE expects that the
intended term was NRTL, the acronym for nationally recognized
testing laboratory.
---------------------------------------------------------------------------
WaterFurnace commented that supporting ISO 13256 and AHRI 600 would
solve the issue. (WaterFurnace No. 20 at p. 8) WaterFurnace stated that
it prefers to use methanol or ethanol as the test liquid because sodium
chloride can damage lab equipment. (Id.)
ClimateMaster supported DOE's proposal to make provisions for low
temperature testing but disagreed with the proposed fluid for testing.
(ClimateMaster, No. 22 at p. 9) ClimateMaster stated that sodium
chloride is not representative of a brine solution used in water-source
applications in the field and is a carryover from a test liquid used in
older standards such as AHRI 330-98, which was corrosive to test lab
facilities and caused premature wear of hydronic components. (Id.)
ClimateMaster recommended that DOE work with industry to create a
national deviation of 13256-1:1998 that includes provisions for the use
of a 15-percent solution by mass of methanol in water involving a
specific gravity of methanol at 0.976 with a solution temperature of 68
[deg]F. (Id.) ClimateMaster stated that this fluid is commonly used in
the industry and has been an available option in the AHRI 13256-1:1998
certification program since its inception, and if DOE does not select
this solution, an alternative option would be a 20-percent solution of
propylene glycol, which is also commonly used in the industry. (Id.)
ClimateMaster supported DOE's proposal to require a standard set of
properties for consistent performance calculations but disagreed that
the only reference allowed for sink or source liquids can be the 2001
ASHRAE Handbook, stating that it does not include properties for
alternative testing fluids, such as methanol in water, and therefore
limits the available options for testable brine solutions. (Id.)
ClimateMaster recommended that DOE provide provisions under a national
deviation of ISO 13256-1:1998 while allowing for the use of other
established property databases in addition to the 2001 ASHRAE handbook,
such as the published data from Melinder 2010.\13\ (Id.) WaterFurnace
agreed with the need for a specified source of properties and commented
that supporting ISO 13256
[[Page 84214]]
and AHRI 600 would solve the issue. (WaterFurnace, No. 20 at p. 8)
---------------------------------------------------------------------------
\13\ Properties of Secondary Working Fluids for Indirect
Systems, Melinder, 2010 (``Melinder 2010'').
---------------------------------------------------------------------------
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 in appendix C1. Section 5.4.14
of AHRI 600-2023 specifies that all cooling and heating tests be
conducted with a 15 percent solution by mass of methanol in water, with
a tolerance of 2 percentage points on the solution concentration and
requires that the concentration be verified prior to and after
completion of all standard rating tests. Section 5.4.14 of AHRI 600-
2023 also specifies to use Melinder 2010 as the source for all
thermodynamic properties of the test liquid. Finally, sections 6.3.3.2
and 6.4.3.2 of AHRI 600-2023 include provisions to remove any influence
of the methanol solution on efficiency ratings, so that values are
similar to those that would result from testing using pure water, which
is the most common liquid used in non-geothermal installations of
WSHPs. Specifically, these provisions specify to multiply all measured
capacity values by 1.01 and to multiply all measured cooling total
power values by 0.99.
DOE has concluded that the provisions in AHRI 600-2023 regarding
test liquid and specific heat capacity provide a representative and
repeatable method for testing WSHPs. Comments received in response to
the August 2022 NOPR and discussion in AHRI 600 committee meetings
indicate that a methanol solution is a more representative test liquid
than sodium chloride brine and is more practical for testing as it is
not corrosive to laboratory equipment. Further, the AHRI 600-2023
requirement to use methanol solution for all tests ensures repeatable
results and minimizes test burden by avoiding a need to change test
liquid between tests. By specifying use of Melinder 2010 as the source
for thermodynamic properties, AHRI 600-2023 also ensures that
thermodynamic properties for the test fluid are applied consistently.
Additionally, the provisions in sections 6.3.3.2 and 6.4.3.2 of AHRI
600-2023 adjust measured values to be more representative of WSHP
operation in non-geothermal applications (which do not encounter
freezing temperatures), without the need to change test liquids to use
water for higher temperature tests and methanol for low-temperature
heating tests. DOE also considers the inclusions of these provisions in
AHRI 600-2023 to represent industry consensus on the most appropriate
method for testing WSHPs. Therefore, for the reasons discussed, DOE is
incorporating by reference into appendix C1 the test liquid provisions
from AHRI 600-2023 in this final rule.
5. Liquid Flow Rate
The current DOE test procedure, through adoption of section 4.1.6.2
of ISO 13256-1:1998, requires units with an integral liquid pump to be
tested at the liquid flow rates specified by the manufacturer or those
obtained at zero ESP difference, whichever provides the lower liquid
flow rate. 10 CFR 431.96. Section 4.1.6.3 of ISO 13256-1:1998 requires
that units without an integral liquid pump be tested at a liquid flow
rate specified by the manufacturer.
In contrast to ISO 13256-1:1998, DOE noted in the June 2018 RFI
that AHRI 340/360-2022 does not use a manufacturer-specified liquid
flow rate, and instead specifies inlet and outlet water temperatures
for WCUACs to be 85 [deg]F and 95 [deg]F, respectively, for standard-
rating full-capacity operation. The temperature difference between
inlet and outlet determines the liquid flow rate for the test. 83 FR
29048, 29054.
In the August 2022 NOPR, DOE proposed to incorporate by reference
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs,
including Table 6. 87 FR 53302, 53330. Table 6 of AHRI 340/360-2022
specifies inlet and outlet liquid temperatures of 85 [deg]F and 95
[deg]F, respectively, for standard-rating cooling full-capacity
operation. Id. This requires that liquid flow rate for the full-load
cooling test is set at a level that results in a 10 [deg]F temperature
rise from the 85 [deg]F inlet to the 95 [deg]F outlet temperature. Id.
Also, DOE proposed to adopt table 9 of AHRI 340/360-2022, which
specifies use of manufacturer-specified part-load water flow rates for
part-load tests. Id. at 87 FR 53331. In addition, DOE proposed that
section E7 of AHRI 340/360 2022, which addresses units with condenser
head pressure control stating that part-load liquid flow rate shall not
exceed the liquid flow rate used for the full-load tests, be adopted in
sections 5.1.1 and 5.1.2.1.2 of proposed appendix C1. Id. For heating
tests, DOE proposed to specify in section 6.1 of proposed appendix C1
that if IEER is determined using option 1 in section 5.1 of proposed
appendix C1, the liquid flow rate determined from the ``Standard Rating
Conditions Cooling'' test for water-cooled equipment, as defined in
Table 6 of AHRI 340/360-2022, must be used for all heating tests. Id.
If IEER is determined using option 2 in section 5.1 of proposed
appendix C1, DOE proposed in section 5.1.2.1.1 of proposed appendix C1
to use the liquid flow rate determined from the CFL3 high temperature
cooling test for all heating tests. Id. Lastly, relating to tolerances,
DOE proposed to require a condition tolerance of 1 percent for liquid
flow rate, consistent with the condition tolerance specified in Table 9
of ISO 13256-1:1998 and adopt Table 11 of AHRI 340/360-2022, which
specifies an operating tolerance of 2 percent for liquid flow rate. Id.
DOE requested commented on its proposal to adopt the AHRI 340/360-
2022 approach for setting liquid flow rate for the full-load cooling
test, namely by specifying inlet and outlet liquid temperature
conditions rather than using a manufacturer-specified flow rate. Id.
Additionally, DOE requested feedback on its proposals to use
manufacturer-specified part-load liquid flow rates for part-load tests,
that the part-load flow rate be no higher than the full-load flow rate,
and to use the full-load liquid flow rate if no part-load liquid flow
rate is specified. Id. In relation to heating tests, DOE requested
comment on its proposal to use the liquid flow rate determined from the
full-load cooling test for all heating tests. Id. Lastly, DOE requested
comment on its proposal to specify an operating tolerance of 2 percent
and a condition tolerance of 1 percent for liquid flow rate in all
tests with a target liquid flow rate. Id. at 87 FR 53331-53332.
In response to the August 2022 NOPR, ClimateMaster and WaterFurnace
stated that they disagree with the proposal to adopt the AHRI 340/360
approach for setting liquid flow rate because it moves the test
standard along a prescriptive path that would discourage innovation for
improvements in pressure drop and flow rate in heat exchanger design.
(ClimateMaster, No. 22 at pp. 9-10; WaterFurnace, No. 20 at pp. 8-9)
ClimateMaster recommended that DOE allow manufacturers to specify a
given flow rate for full-load cooling tests. (ClimateMaster, No. 22 at
p. 10) ClimateMaster also commented that DOE should also specify a
maximum limit of 3.5 GPM/ton, which ClimateMaster stated aligns with
DOE's statements in the August 2022 NOPR that 3 GPM/ton is a typical
water flow rate for WSHPs that results in a temperature rise of
approximately a 10 [deg]F. (Id. at pp. 9-10) ClimateMaster commented
that while flowrate is typically used and specified when testing WSHP
equipment, this is not the case for temperature rise. (Id. p. 10) MIAQ
recommended that DOE continue to support ISO 13256-1. (MIAQ, No. 23 at
p. 7)
Regarding the part-load liquid flow rates, ClimateMaster supported
DOE's
[[Page 84215]]
proposal to use manufacturer-specified part-load liquid flow rates for
part-load tests. (ClimateMaster, No. 22 at p. 10) ClimateMaster
recommended that the full-load liquid flow rate should be used for
part-load tests if the system does not automatically reduce the liquid
flow rate in part-load operation to the part-load flow rate when
installed. (Id.) WaterFurnace agreed with DOE's proposal to use
manufacturer-specified part-load liquid flow rates for part-load tests
and commented that supporting ISO 13256/AHRI 600 would solve the issue.
(WaterFurnace, No. 20 at p. 9)
Regarding liquid flow rate for heating tests, ClimateMaster
supported DOE's proposal to use the full-load cooling liquid flow rate
for all full-load heating tests. (ClimateMaster, No. 22 at p. 10) MIAQ
commented that using the liquid flow rate determined from the full-load
cooling test for all heating tests could be a problem in conditions
where the saturated suction temperature is too high, overloading the
compressor. (MIAQ, No. 23 at p. 7) MIAQ stated that this may not be an
issue with a low enough EWT. (Id.) MIAQ commented that systems with
inverter-driven compressors and active head pressure control may
present challenges to fulfilling these tests. (Id.) WaterFurnace
commented that supporting ISO 13256 and AHRI 600 would solve the issue.
(WaterFurnace, No. 20 at p. 9) WaterFurnace commented that most
standards have abandoned the prescriptive approach of determining
liquid flow rate from the full-load cooling test to allow innovation
and efficiency improvement. (Id.) WaterFurnace stated that using
manufacturer-specified flow rate is preferred. (Id.)
Regarding tolerances liquid flow rates, ClimateMaster,
WaterFurnace, and MIAQ commented in support of DOE's proposal to
specify an operating tolerance of 2 percent and a condition tolerance
of 1 percent for liquid flow rate in all tests with a target liquid
flow rate. (ClimateMaster, No. 22 at p. 10; WaterFurnace, No. 20 at p.
9; MIAQ, No. 23 at p. 7)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. Section
5.4.15 of AHRI 600-2023 includes provisions regarding liquid flow rate.
Specifically, this section specifies use of a manufacturer-specified
flow rate rather than a fixed temperature rise (as recommended by
commenters), but, similar to ClimateMaster's recommendation, section
5.4.15 also provides a maximum flow rate of 0.275 GPM per kBtu/h (which
is equivalent to 3.3 GPM/ton, slightly lower than the 3.5 GPM/ton limit
recommended in ClimateMaster's comment). Section 5.4.14 also specifies
that a single manufacturer-specified flow rate be used for all tests,
unless the equipment automatic adjusts flow rate or the liquid flow
rate is reduced for operation at low EWTs for head pressure control,
per section 5.9 of AHRI 600-2023. Further, section 5.4.15 specifies
that if there is not a specified liquid flow rate and that the system
does not provide automatic adjustment of the liquid flow that a liquid
flow rate of 0.25 GPM per kBtu/h is used for all tests. It also
specifies a liquid flow rate condition tolerance of 1 percent.
DOE has concluded that the approach for liquid flow rate specified
in AHRI 600-2023 provides a representative and appropriate approach for
testing WSHPs. The use of manufacturer-specified flow rate provides
flexibility to manufacturers while the maximum liquid flow rate limit
prevents manufacturer specification of unrepresentatively high flow
rates for testing. With regards to MIAQ's concern that using the liquid
flow rate determined from the full-load cooling test for all heating
tests could be a problem in conditions where the saturated suction
temperature is too high, overloading the compressor, DOE notes that the
provisions specified in AHRI 600-2023 and incorporated by reference in
this final rule allow manufacturers to specify different flow rates for
tests other than the full-load cooling test so long as the specified
flow rates for other tests are (a) below the maximum flow rate of 0.275
GPM per kBtu/h; and (b) achieved via automatic adjustment of the liquid
flow rate by the equipment under test. Therefore, a manufacturer would
have the ability to set different liquid flow rates for tests other
than full-load cooling tests to ensure operation representative of how
the equipment would operate under such conditions in field
installations.
DOE also considers the inclusions of these provisions in AHRI 600-
2023 to represent industry consensus on the most appropriate method for
testing WSHPs. Therefore, for the reasons discussed, DOE is
incorporating by reference into appendix C1 the liquid flow rate
provisions from AHRI 600-2023 in this final rule.
6. Refrigerant Line Losses
Split-system WSHPs have refrigerant lines that can transfer heat to
and from their surroundings, which can incrementally affect measured
capacity. To account for this transfer of heat (referred to as ``line
losses''), the current DOE WSHP test procedure, through adoption of ISO
13256-1:1998, provides that if line loss corrections are to be made,
they shall be included in the capacity calculations (in section B4.2
for the indoor air enthalpy method and in section C3.3 for the liquid
enthalpy test method of ISO 13256-1:1998). 10 CFR 431.96. ISO 13256-
1:1998 does not specify the circumstances that require line loss
corrections nor the method to use to determine an appropriate
correction.
Section 7.3.3.4 of ANSI/ASHRAE 37-2009, the method of test
referenced in AHRI 340/360-2022, specifies more detailed provisions to
account for line losses of split systems in the outdoor air enthalpy
method, and section 7.6.7.1 of ANSI/ASHRAE 37-2009 specifies to use the
same provisions for the outdoor liquid coil method.
In the August 2022 NOPR, DOE proposed to incorporate by reference
specific sections of AHRI 340/360-2022. 87 FR 53302, 53332. AHRI 340/
360-2022 in turn references sections 7.6.7.1 and 7.3.3.4 of ANSI/ASHRAE
37-2009. Id. Sections 7.6.7.1 and 7.3.3.4 of ANSI/ASHRAE 37-2009
specify calculations for determining the line losses for bare copper or
insulated lines. Id. DOE requested comment on the proposal to adopt the
provisions for line loss adjustments included in sections 7.6.7.1 and
7.3.3.4 of ANSI/ASHRAE 37-2009 through incorporation by reference of
AHRI 340/360-2022. Id.
In response to the August 2022 NOPR, ClimateMaster commented that
adopting the line loss adjustments in ASHRAE 37-2009 is acceptable, as
it is an industry best practice, but ClimateMaster stated it does not
produce any split system heat pumps for use in commercial applications.
(ClimateMaster, No. 22 at p.10) ClimateMaster recommended that DOE work
with industry to create a national deviation of ISO 13256-1:1998 that
adopts the provisions of ANSI/ASHRAE 37-2009. (Id.) WaterFurnace agreed
with DOE's proposal. (WaterFurnace, No. 20 at p. 9)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes section 5.1 of AHRI 600-2023. This section in turn references
sections 7.6.7.1 and 7.3.3.4 of ANSI/ASHRAE 37-2009, which is
consistent with the proposal from the August 2022 NOPR. DOE considers
the inclusion of these provisions in the AHRI 600-2023 to represent
industry consensus that these provisions provide an appropriate method
for testing WSHPs. As a result, DOE is incorporating by reference into
appendix C1 the methods from AHRI
[[Page 84216]]
600-2023 for calculating line loss adjustments in this final rule.
7. Airflow Measurement
The current DOE WSHP test procedure, through adoption of section
D.1 of ISO 13256-1:1998, requires airflow measurements to be made in
accordance with the provisions specified in several different industry
test standards, ``as appropriate.'' \14\ 10 CFR 431.96. However, ISO
13256-1:1998 is not explicit regarding the circumstances under which
the different airflow measurement approaches included in these industry
test standards should be used.
---------------------------------------------------------------------------
\14\ The cited industry test standards include: ISO 3966:1977,
``Measurement of fluid flow in closed conduits--Velocity area method
using Pitot static tubes;'' ISO 5167-1:1991, ``Measurement of fluid
flow by means of pressure differential devices--Part 1: Orifice
plates, nozzles and Venturi tubes inserted in circular cross-section
conduits running full;'' and ISO 5221:1984, ``Air Distribution and
air diffusion--Rules to methods of measuring airflow rate in an air
handling duct.'' These standards can be purchased from the ISO store
at https://www.iso.org/store.html.
---------------------------------------------------------------------------
Section F8 of ISO 13256-1:1998 specifies the requirements for the
nozzle apparatus used to measure airflow. This device determines
airflow by measuring the change in pressure across a nozzle of known
geometry. Airflow derivations using this approach often include a
discharge coefficient (i.e., the ratio of actual discharge air to
theoretical discharge air) to account for factors that reduce the
actual discharge air, such as nozzle resistance and airflow turbulence.
In general, as the nozzle throat diameter decreases, nozzle resistance
increases, thereby reducing actual discharge which is characterized by
a lower discharge coefficient. Turbulent airflow (as characterized by
Reynolds numbers \15\) and temperature also impact the discharge
coefficient.
---------------------------------------------------------------------------
\15\ ``Reynolds number'' is a dimensionless number that
characterizes the flow properties of a fluid. Section F8.9 of ISO
13256-1:1998 includes an equation for calculating Reynolds number
that depends on a temperature factor, air velocity, and throat
diameter.
---------------------------------------------------------------------------
Section F8.9 of ISO 13256-1:1998 specifies that it is preferable to
calibrate the nozzles in the nozzle apparatus, but that nozzles of a
specific geometry may be used without calibration and by using the
appropriate discharge coefficient specified in a lookup table in
section F8.9 of ISO 13256-1:1998. ISO 13256-1:1998 does not specify the
method that should be applied, however, to determine the coefficient of
discharge for conditions that do not exactly match the values provided
in the look-up table.
Elsewhere, sections 6.2 and 6.3 of ANSI/ASHRAE 37-2009 includes
provisions regarding the nozzle airflow measuring apparatus that are
identical to the provisions in section F8 of ISO 13256-1:1998, except
for the method used to determine the coefficient of discharge. Section
6.3.3 of ANSI/ASHRAE 37-2009 uses a calculation in place of the look-up
table used in ISO 13256-1:1998, thereby allowing determination of the
coefficient of discharge at any point within the specified range.
In the August 2022 NOPR, DOE proposed to incorporate by reference
specific sections of AHRI 340/360-2022. 87 FR 53302, 53333. AHRI 340/
360-2022 in turn references the test method in ANSI/ASHRAE 37-2009. Id.
Sections 6.2 and 6.3 of ANSI/ASHRAE 37-2009 include provisions
regarding the nozzle airflow measuring apparatus that are identical to
the provisions in section F8 of ISO 13256-1:1998, except for the method
used to determine the coefficient of discharge. Id. Section 6.3.3 of
ANSI/ASHRAE 37-2009 uses a calculation to determine the coefficient of
discharge, thereby allowing determination of the coefficient of
discharge at any point within the specified range. Id. DOE requested
comment on the proposal to adopt the calculation of discharge
coefficients and air measurement apparatus requirements as specified in
ANSI/ASHRAE 37-2009. Id.
In response to the August 2022 NOPR, ClimateMaster supported DOE's
proposal to adopt the calculation of discharge coefficients and air
measurement apparatus requirements of ANSI/ASHRAE 37-2009, as it is an
industry best practice, and recommended that DOE work with industry to
create a national deviation of ISO 13256-1:1998 that includes the
provisions of ANSI/ASHRAE 37-2009. (ClimateMaster No. 22 at p. 10)
WaterFurnace agreed with DOE's proposal. (WaterFurnace, No. 20 at p. 9)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes section 5.1 of AHRI 600-2023. This section in turn references
the test method in ANSI/ASHRAE 37-2009, which is consistent with the
proposal from the August 2022 NOPR. DOE considers the inclusion of
these provisions in AHRI 600-2023 to represent industry consensus that
these provisions provide an appropriate method for testing WSHPs. As a
result, DOE is incorporating by reference into appendix C1 the methods
from AHRI 600-2023 for measuring airflow in this final rule.
8. Air Condition Measurement
Indoor air temperature and humidity are key parameters that affect
WSHP performance, and for this reason, ISO 13256-1:1998 requires
accurate indoor air condition measurements. However, informative
annexes E and F of ISO 13256-1:1998 specify few requirements for the
methods used to measure indoor air temperature and humidity.
In the August 2022 NOPR, DOE proposed to incorporate by reference
appendix C of AHRI 340/360-2022. 87 FR 53302, 53333. Appendix C of AHRI
340/360-2022 provides detailed specifications for the measurement of
air conditions (including indoor air), including aspirating
psychrometer requirements in section C3.2.1 of AHRI 340/360-2022 and
sampling requirements in section C3.3 of AHRI 340/360-2022. Id. DOE
requested commented on the proposal to adopt the air condition
measurement provisions in appendix C of AHRI 340/360-2022. Id.
In response to the August 2022 NOPR, ClimateMaster supported DOE's
proposal to adopt the air condition measurement provisions in appendix
C of AHRI 340/360-2022, as it is industry best practice, and
recommended that DOE work with industry to create a national deviation
of ISO 13256-1:1998 that includes similar air condition measurement
provisions. (ClimateMaster No. 22 at p. 11) WaterFurnace agreed with
DOE's proposal. (WaterFurnace No. 20 at p. 9)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes appendix C of AHRI 600-2023. This language is consistent with
appendix C of AHRI 340/360-2022, as proposed in the August 2022 NOPR,
and addresses comments that DOE should adopt AHRI 600. DOE considers
the air condition measurement approach specified in AHRI 600-2023 to
represent industry consensus regarding the most appropriate method for
measuring air conditions for WSHPs. As a result, DOE is incorporating
by reference into appendix C1 the methods from AHRI 600-2023 for
measuring air conditions in this final rule.
9. Duct Losses
In the calculations for cooling and heating capacities for the
indoor air enthalpy test method of ISO 13256-1:1998, the test standard
includes a footnote in sections B3 and B4 of annex B stating that the
equations do not provide allowances for heat leakage in the test
equipment (i.e., duct losses). In
[[Page 84217]]
contrast, section 7.3.3.3 of ANSI/ASHRAE 37-2009 requires adjustments
for such heat leakages and specifies methods to calculate appropriate
values for the adjustments.
In the August 2022 NOPR, DOE proposed to incorporate by reference
specific sections of AHRI 340/360-2022. 87 FR 53302, 53334. AHRI 340/
360-2022 in turn references section 7.3.3.3 of ASHRAE 37-2009, which
requires and provides equations for duct loss adjustments. Id. DOE
requested comment on whether the duct loss adjustments as described in
section 7.3.3.3 of ANSI/ASHRAE 37-2009 or any other duct loss
adjustments are used to adjust capacity measured using the indoor air
enthalpy method when testing WSHPs. Id.
In response to the August 2022 NOPR, ClimateMaster supported DOE's
proposal to adopt the duct loss provisions as it is an industry best
practice for companies that produce split-system heat pumps for use in
commercial applications. (ClimateMaster, No. 22 at p. 11) ClimateMaster
recommended that DOE work with industry to create a national deviation
of ISO 13256-1:1998 that includes these provisions of ANSI/ASHRAE 37-
2009. (Id.) WaterFurnace agreed with DOE's proposal. (WaterFurnace, No.
20 at pp. 9)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes section 5.1 of AHRI 600-2023. This section in turn references
ANSI/ASHRAE 37-2009, including section 7.3.3.3, which is consistent
with the proposal from the August 2022 NOPR. DOE considers the
inclusion of these provisions in AHRI 600-2023 to represent industry
consensus that these provisions provide an appropriate method for
testing WSHPs. Therefore, DOE is incorporating by reference into
appendix C1 the equations for duct loss adjustments from section 5.1 of
AHRI 600-2023 in this final rule. Regarding the comment from
ClimateMaster, DOE notes that these provisions for calculating duct
losses apply to testing all WSHPs, not just split systems.
10. Refrigerant Charging
The amount of refrigerant can have a significant impact on the
system performance of air conditioners and heat pumps. DOE's current
test procedure for WSHPs requires that units be set up for test in
accordance with the manufacturer installation and operation manuals. 10
CFR 431.96(e). In addition, the current DOE test procedure states that
if the manufacturer specifies a range of superheat, sub-cooling, and/or
refrigerant pressures in the installation and operation manual, any
value within that range may be used to determine refrigerant charge or
mass of refrigerant, unless the manufacturer clearly specifies a rating
value in its installation or operation manual, in which case the
specified rating value shall be used. 10 CFR 431.96(e)(1) However, the
current DOE test procedure for WSHPs does not provide charging
instructions to be used if the manufacturer does not provide
instructions in the manual that is shipped with the unit or if the
provided instructions are unclear or incomplete. In addition, ISO
13256-1:1998 does not provide any specific guidance on setting and
verifying the refrigerant charge of a unit aside from stating in
section A2.3 of that standard that equipment shall be evacuated and
charged with the type and amount of refrigerant specified in the
manufacturer's instructions, where necessary.
In the August 2022 NOPR, DOE proposed to incorporate by reference
section 5.8 of AHRI 340/360-2022. 87 FR 53302, 53334. This section
specifies refrigerant charging parameters, including specifying which
set of installation instructions to use for charging, explaining what
to do if no instructions are provided, specifying that target values of
parameters are the centers of the ranges allowed by installation
instructions, and specifying tolerances for the measured values. Id.
The approach also requires that refrigerant line pressure gauges be
installed for single-package units, unless otherwise specified in
manufacturer instructions. Id. DOE requested comment on the proposal to
adopt the refrigerant charging requirements in section 5.8 of AHRI 340/
360-2022. Id. at 87 FR 53335.
In response to the August 2022 NOPR, ClimateMaster commented that
while all commercially single package WSHP units are developed with
specific factory system charge weights, the only provision DOE proposed
for a charge weight tolerance is in Table 4 of section 5.8.3 of AHRI
340/360-2022, which specifies a tolerance of 2 oz.
(ClimateMaster, No. 22 at p. 11) ClimateMaster commented that it
considers this tolerance unacceptable, as 2 oz can be upwards of 10
percent of the overall system charge on small capacity heat pumps.
(Id.) ClimateMaster further stated that the procedures for charging
that DOE provided in sections 5.8.4.1 and 5.8.4.2 of AHRI 340/360-2022
are not applicable as most single package systems do not contain a
liquid line service connection. (Id.) ClimateMaster commented that the
tolerances that DOE provided in Table 4 of section 5.8.3 of AHRI 340/
360-2022 reference items related to outdoor air conditions, which are
not applicable to WSHPs. (Id.) ClimateMaster commented that DOE's
proposal lacks provisions for the possibility that the operating mode
of the system could set the charge. (Id.) For these reasons,
ClimateMaster recommended that DOE work with industry to create a
national deviation of ISO 13256-1:1998 that allows the WSHP industry to
develop a list of charging provisions that meet the intent of those
found in AHRI 340/360-2022. (Id.) WaterFurnace agreed with DOE's
proposal regarding refrigerant charging. (WaterFurnace, No. 20 at p. 9)
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes section 5.4.11 of AHRI 600-2023. This language is consistent
with section 5.8 of AHRI 340/360-2022, as proposed for use in the
August 2022 NOPR, and addresses commenters' concerns that DOE should
adopt AHRI 600. With regards to the comment from ClimateMaster
regarding the refrigerant charging proposals in the August 2022 NOPR
(which are consistent with the provisions in AHRI 600-2023), DOE notes
that these provisions are used only if the manufacturer's charging
instructions do not specify a tighter charging tolerance (as specified
in section 5.4.11.4 of AHRI 600-2023). Therefore, these provisions
provide flexibility to manufacturers to specify charging instructions
appropriate to their models and serve mainly to address cases in which
manufacturer's instructions provide inadequate, incomplete, or
conflicting charging instructions. Specifically, these provisions allow
manufacturers to specify tighter tolerances and/or to specify charging
based on whatever method is most appropriate for a given model.
DOE considers the inclusion of these provisions in AHRI 600-2023 to
represent industry consensus that these provisions provide an
appropriate method for testing WSHPs. Therefore, DOE is incorporating
by reference into appendix C1 the refrigerant charging requirements
from section 5.4.11 of AHRI 600-2023 in this final rule.
11. Voltage
Operating voltage can affect the measured efficiency of air
conditioners and heat pumps. The current DOE WSHP test procedure,
through adoption of Tables 1 and 2 of ISO 13256-1:1998, requires units
rated with dual nameplate voltages to be tested at both
[[Page 84218]]
voltages or at the lower voltage if only a single rating is to be
published. 10 CFR 431.96.
In the August 2022 NOPR, DOE proposed to incorporate by reference
section 6.1.3.1 of AHRI 340/360-2022. 87 FR 53302, 53335. Section
6.1.3.1 of AHRI 340/360-2022 specifies that units with dual nameplate
voltage ratings must be tested at the lower of the two voltages if only
a single standard rating is to be published, or at both voltages if two
standard ratings are to be published. Id. This approach is equivalent
to the approach for dual nameplate voltages specified in tables 1 and 2
of ISO 13256-1:1998 and tables 2 and 3 of ISO 13256-1:2021. Id. DOE
requested commented on the proposal to adopt the voltage provisions in
section 6.1.3.1 of AHRI 340/360-2022. Id.
In response to the August 2022 NOPR, ClimateMaster supported DOE's
proposal to adopt the voltage provisions in section 6.1.3.1 of AHRI
340/360-2022 because it is industry best practice and recommended that
DOE work with industry to create a national deviation of ISO 13256-
1:1998 that includes the proposed language. (ClimateMaster, No. 22 at
pp. 11-12) WaterFurnace agreed with DOE's proposal. (WaterFurnace, No.
20 at p. 9).
As discussed in section III.D of this final rule, DOE is
incorporating by reference AHRI 600-2023 into appendix C1. This
includes section 6.2.2 of AHRI 600-2023. This language is consistent
with section 6.1.3.1 of AHRI 340/360-2022, which was proposed in the
August 2022 NOPR, as well as with tables 1 and 2 of ISO 13256-1:1998
and tables 2 and 3 of ISO 13256-1:2021. DOE considers the inclusion of
these voltage provisions in AHRI 600-2023 to represent industry
consensus that these provisions provide an appropriate method for
testing WSHPs. As a result, DOE is incorporating by reference into
appendix C1 the voltage provisions from AHRI 600-2023 in this final
rule.
12. Non-Standard Low-Static Indoor Fan Motors
As discussed in section III.F.1.a of this document, DOE is adopting
higher ESPs for WSHPs with a cooling capacity greater than or equal to
75,000 Btu/h that are included in section 5.5.1.1 of AHRI 600-2023 and
are consistent with the ESP levels recommended in the ACUAC and ACUHP
Working Group TP Term Sheet. However, individual models of WSHPs in
this capacity range with indoor fan motors intended for installation in
applications with a low ESP may not be able to operate at the proposed
full-load ESP requirements at the full-load indoor rated airflow. To
address this situation, section 3.2.30 of AHRI 600-2023 defines ``non-
standard low-static indoor fan motors'' as motors in units with cooling
capacity greater than or equal to 75,000 Btu/h which cannot maintain
ESP as high as specified in the test procedure when operating at the
full-load rated indoor airflow and that are distributed in commerce as
part of an individual model within the same basic model that is
distributed in commerce with a different motor specified for testing
that can maintain the required ESP. Section 5.7.4.3 of AHRI 600-2023
includes test provisions for WSHPs with non-standard low-static indoor
fan motors that cannot reach the ESP within tolerance during testing,
which require using the maximum available fan speed that does not
overload the motor or motor drive, adjusting the airflow-measuring
apparatus to maintain airflow within tolerance, and operating with an
ESP as close as possible to the minimum ESP requirements for testing.
This approach is consistent with the industry test standard referenced
by the DOE test procedure for DX-DOASes (AHRI 920-2020, section
6.5.2.5). See appendix B to 10 CFR 431.96.
As discussed in section III.G.3 of this document, DOE is clarifying
that representations for a WSHP basic model must be based on the least
efficient individual model(s) distributed in commerce within the basic
model (with the exception specified in 10 CFR 429.43(a)(3)(v)(A) for
certain individual models with the components listed in Table 6 to 10
CFR 429.43(a)(3)). DOE has concluded that the combination of (1) the
provisions in AHRI 600-2023 for testing models with ``non-standard low-
static indoor fan motors'' with (2) the requirement that basic models
be rated based on the least efficient individual model (with certain
exceptions, as discussed) provides an appropriate approach for handling
WSHP models with these motors because if an individual model with a
non-standard low-static indoor fan motor is tested, the test would be
conducted at an indoor airflow representative for that model. But
because testing at the rated airflow for such an individual model would
result in testing at an ESP lower than the requirement and thus a lower
indoor fan power, the representations for that basic model will be
required to be based on an individual model with an indoor fan motor
that can achieve the ESP requirements at the rated airflow. Consistent
with incorporating by reference AHRI 600-2023 into appendix C1, in this
final rule, DOE is adopting the AHRI 600-2023 provisions for testing
models with non-standard low-static indoor fan motors.
G. Configuration of Unit Under Test
1. Background and Summary
WSHPs are sold with a wide variety of components, including many
that can optionally be installed on or within the unit both in the
factory and in the field. In all cases, these components are
distributed in commerce with the WSHP but can be packaged or shipped in
different ways from the point of manufacturer for ease of
transportation. Each optional component may or may not affect a model's
measured efficiency when tested to the DOE test procedure adopted in
this final rule. For certain components not directly addressed in the
DOE test procedure, DOE proposed to adopt more specific instructions on
how each component should be handled for the purposes of making
representations in 10 CFR part 429 in the August 2022 NOPR. 87 FR
53302, 53335. Specifically, the proposed instructions provide
manufacturers clarity on how components should be treated and how to
group individual models with and without optional components for the
purposes of representations to reduce burden. Id.
As proposed in the August 2022 NOPR, DOE is handling WSHP
components in two distinct ways in this final rule to help
manufacturers better understand their options for developing
representations for their differing product offerings. Id. First, as
proposed in the August 2022 NOPR, the treatment of some components is
specified by the test procedure to limit their impact on measured
efficiency. Id. For example, a fresh air damper must be set in the
closed position and sealed during testing, resulting in a measured
efficiency that would be similar or identical to the measured
efficiency for a unit without a fresh air damper. Id.
Second, for certain components not directly addressed in the DOE
test procedure, this final rule adopts the specific instructions
proposed in the August 2022 NOPR on how each component should be
handled for the purposes of making representations in 10 CFR part 429.
See Id. at 87 FR 53335-53336. Specifically, these instructions provide
manufacturers clarity on how components should be treated and how to
group individual models with and without optional components for the
purposes of representations, in order to reduce burden. DOE is adopting
these provisions in 10 CFR part 429 to allow for testing of certain
individual models
[[Page 84219]]
that can be used as a proxy to represent the performance of equipment
with multiple combinations of components. DOE is adopting provisions
expressly allowing certain models to be grouped together for the
purposes of making representations and allowing the performance of a
model without certain optional components to be used as a proxy for
models with any combinations of the specified components, even if such
components would impact the measured efficiency of a model. Steam/
hydronic heat coils are an example of such a component. The efficiency
representation for a model with a steam/hydronic heat coil is based on
the measured performance of the WSHP as tested without the component
installed because the steam/hydronic heat coil is not easily removed
from the WSHP for testing.\16\ Id.
---------------------------------------------------------------------------
\16\ Note that in certain cases, as explained further in section
III.G.3.c of this document, the representation may have to be based
on an individual model with a steam/hydronic coil.
---------------------------------------------------------------------------
In this final rule, DOE is adopting these provisions in 10 CFR part
429 as proposed to allow for testing of certain individual models that
can be used as a proxy to represent the performance of equipment with
multiple combinations of components, though DOE is also adopting
provisions that address additional components not included in the
August 2022 NOPR, reflecting comments received in response to the
August 2022 NOPR and provisions in AHRI 600-2023.
2. Components Addressed Through Test Provisions of 10 CFR Part 431,
Subpart F, Appendix C1
In the August 2022 NOPR, DOE proposed test provisions for specific
components, including all of the components listed in section D3 of
AHRI 340/360-2022 for which there is a test procedure action which
limits the impacts on measured efficiency (i.e., test procedure
provisions specific to the component that are not addressed by general
provisions in AHRI 340/360-2022 that negates the component's impact on
performance). Id. at 87 FR 53336. These provisions specified how to
test a unit with such a component (e.g., for a unit with hail guards,
remove hail guards for testing). Id. The proposed test provisions were
consistent with the provision in section D3 of AHRI 340/360-2022 but
included revisions for further clarity and specificity (e.g., adding
clarifying provisions for how to test units with modular economizers as
opposed to units shipped with economizers installed). Id. Specifically,
DOE proposed to require in appendix C1 that steps be taken during unit
set-up and testing to limit the impacts on the measurement of these
components:
Desiccant Dehumidification Components
Air Economizers
Fresh Air Dampers
Power Correction Capacitors
Ventilation Energy Recovery Systems (VERS)
Barometric Relief Dampers
UV Lights
Steam/Hydronic Coils
Refrigerant Reheat
Fire/Smoke/Isolation Dampers
Process Heat Recovery/Reclaim Coils/Thermal Storage.
Id. at 87 FR 53336-53337.
As DOE did not receive any comments regarding this proposal in
response to the August 2022 NOPR, it is adopting the provisions as
proposed in this final rule.
3. Components Addressed Through Representation Provisions of 10 CFR
429.43
In the August 2022 NOPR, consistent with the Commercial HVAC Term
Sheet and the Commercial HVAC Enforcement Policy, DOE proposed
provisions that explicitly allow representations for individual models
with certain components to be based on testing for individual models
without those components and proposed a table (``Table 6 to Paragraph
(a)(3)(v)(A)'') \17\ at 10 CFR 429.43(a)(3) listing the components for
which these provisions would apply. Id. at 87 FR 53337. There are three
components specified explicitly for WSHPs in the Commercial HVAC
Enforcement Policy that are not included in section D3 of AHRI 340/360-
2022: (1) Condenser Pumps/Valves/Fittings; (2) Condenser Water Reheat;
and (3) Electric Resistance Heaters. Id. DOE tentatively concluded that
the inclusion of these components as optional components for WSHPs is
appropriate, except for electric resistance heaters. Id. DOE
tentatively determined that electric resistance heaters would have a
negligible effect on tested efficiency as they would be turned off for
test and not impose a significant pressure drop. Id. DOE proposed the
following components be listed in Table 6 to Paragraph (a)(3)(v)(A):
---------------------------------------------------------------------------
\17\ DOE notes that in the August 2022 NOPR, DOE referred to
this table as ``Table 1 to Paragraph (a)(3)(ii)(A) .'' Due to the
publication of other regulatory documents, DOE is now referring to
this Table as ``Table 6 to Paragraph (a)(3)(v)(A).''
Desiccant Dehumidification Components,
Air Economizers,
Ventilation Energy Recovery Systems (VERS),
Steam/Hydronic Heat Coils,
Refrigerant Reheat, Fire/Smoke/Isolation Dampers,
Powered Exhaust/Powered Return Air Fans,
Sound Traps/Sound Attenuators,
Process Heat Recovery/Reclaim Coils/Thermal Storage,
Indirect/Direct Evaporative Cooling of Ventilation Air,
Condenser Pumps/Valves/Fittings,
Condenser Water Reheat,
Grill Options,
Non-Standard Indoor Fan Motors.
Id.
Additionally, DOE proposed to specify that the basic model
representation must be based on the least efficient individual model
that is a part of the basic model and clarified how this long-standing
basic model provision interacts with the component treatment in 10 CFR
429.43 that was proposed. Id. DOE proposed clarifying instructions for
instances when individual models within a basic model may have more
than one of the specified components and there may be no individual
model without any of the specified components. Id. DOE proposed the
concept of an ``otherwise comparable model group'' (``OCMG''). Id.
As discussed in the August 2022 NOPR, an OCMG is a group of
individual models within the basic model that do not differ in
components that affect energy consumption as measured according to the
applicable test procedure other than the specific components listed in
Table 6 to Paragraph (a)(3)(v)(A) but may include individual models
with any combination of such specified components. Id. Therefore, a
basic model can be composed of multiple OCMGs, each representing a
unique combination of components that affect energy consumption as
measured according to the applicable test procedure, other than the
specified excluded components listed in Table 6 to Paragraph
(a)(3)(v)(A). Id. For example, a manufacturer might include two tiers
of control system within the same basic model, in which one of the
control systems has sophisticated diagnostics capabilities that require
a more powerful control board with a higher wattage input. Id. WSHP
individual models with the ``standard'' control system would be part of
OCMG A, while individual models with the ``premium'' control system
would be part of a different OCMG B, because the
[[Page 84220]]
control system is not one of the specified exempt components listed in
Table 6 to Paragraph (a)(3)(v)(A). Id. However, both OCMGs may include
different combinations of specified exempt components. Id. Also, both
OCMGs may include any combination of characteristics that do not affect
the efficiency measurement, such as paint color. Id.
Further discussed in the August 2022 NOPR, an OCMG is used to
determine which individual models are used to determine a represented
value. Id. Specifically, when identifying the individual model within
an OCMG for the purpose of determining a representation for the basic
model, only the individual model(s) with the least number (which could
be zero) of the specific components listed in Table 6 to Paragraph
(a)(3)(v)(A) is considered. Id. This clarifies which individual models
are exempted from consideration for determination of represented values
in the case of an OCMG with multiple specified components and no
individual models with zero specific components listed in Table 6 to
(a)(3)(v)(A) (i.e., models with a number of specific components listed
in Table 6 to (a)(3)(v)(A) greater than the least number in the OCMG
are exempted). Id. In the case that the OCMG includes an individual
model with no specific components listed in Table 6 to Paragraph
(a)(3)(v)(A), then all individual models in the OCMG with specified
components would be exempted from consideration. Id. The least-
efficient individual model across the OCMGs within a basic model would
be used to determine the representation of the basic model. Id. In the
case where there are multiple individual models within a single OCMG
with the same non-zero least number of specified components, the least
efficient of these would be considered. Id.
In the August 2022 NOPR, DOE relied on the term ``comparable'' as
opposed to ``identical'' to indicate that for the purpose of
representations, the components that impact energy consumption as
measured by the applicable test procedure are the relevant components
to consider. Id. In other words, differences that do not impact energy
consumption, such as unit color and presence of utility outlets, would
not warrant separate OCMGs. Id.
The use of the OCMG concept results in the represented values of
performance that are representative of the individual model(s) with the
lowest efficiency found within the basic model, excluding certain
individual models with the specific components listed in Table 6 to
Paragraph (a)(3)(v)(A). Id. at 87 FR 53337-53338. Further, the
approach, as proposed, was structured to more explicitly address
individual models with more than one of the specific components listed
in Table 6 to Paragraph (a)(3)(v)(A), as well as instances in which
there is no comparable model without any of the specified components.
Id. at 87 FR 53338. DOE developed a document of examples to illustrate
the approach proposed in the August 2022 NOPR for determining
represented values for WSHPs with specific components, and in
particular the OCMG concept. See EERE-2017-BT-TP-0029; 87 FR 53302,
53338.
In the August 2022 NOPR, DOE proposed provisions in 10 CFR
429.43(a)(3)(v)(A) that included each of the components specified in
section D3 of AHRI 340/360-2022 for which the test provisions for
testing a unit with these components may result in differences in
ratings compared to testing a unit without these components, except for
the following features: (1) Evaporative Pre-cooling of Condenser Intake
Air; (2) Non-Standard Ducted Condenser Fans; and (3) Coated Coils. 87
FR 53302, 53338-53339.
In response to the August 2022 NOPR, ClimateMaster commented that
it agrees with DOE's several proposals on this issue, but it believes
that Table 6 in paragraph (a)(3) should include additional components,
specifically water-side economizers and high effectiveness filters.
(ClimateMaster, No. 22 at p. 12) ClimateMaster recommended that DOE
create a national deviation of ISO 13256-1:1998 that adopts the
proposed language with modifications to include water-side economizers
and high effectiveness indoor filters. (Id.) WaterFurnace commented
that the proposals may work for large motors but noted that the small
volume of these larger motors would not justify regulation efforts and
AHRI 340/360 omits smaller motors. (WaterFurnace, No. 20 at p. 10)
With regards to the comment from ClimateMaster that waterside
economizers and high effectiveness filters should be included in Table
6 to Paragraph (a)(3)(v)(A), DOE notes that the impact of high
effectiveness filters can be entirely mitigated by testing with a
standard filter, which is required by section 5.4.5 of AHRI 600-2023.
Therefore, DOE has concluded that treatment as specific components in
representation provisions in 10 CFR 429.43 is not warranted for high
effectiveness filters. With regards to waterside economizers, DOE has
included waterside economizers and desuperheaters in the updated Table
6 to Paragraph (a)(3)(v)(A) adopted in this final rule, as DOE has
determined that it is appropriate to make representations for WSHPs
without these components present, consistent with the inclusion of
these components in section D3 of AHRI 600-2023.
With regard to the comment from WaterFurnace that only a small
portion of the market has larger motors and therefore that they are not
worth regulating, DOE notes that the approach for non-standard high-
static indoor fan motors (as proposed in the August 2022 NOPR and
included in AHRI 600-2023) does not expand the scope of regulations to
cover equipment with higher-static motors. Equipment that meets the DOE
definition of WSHP is covered equipment, regardless of the size of
indoor fan motor. The adopted approach reduces burden to manufacturers
by allowing grouping of WSHP individual models with non-standard high-
static indoor fan motors in the same basic model as corresponding
individual models with standard indoor fan motors (and thus rating all
individual models in the basic model based on performance with the
standard indoor fan motor), as long as the non-standard high-static
indoor fan motor has the same or better relative efficiency performance
as the standard motor included in the individual model with the
standard indoor fan motor.
4. Enforcement Provisions of 10 CFR 429.134
In the August 2022 NOPR, consistent with the Commercial HVAC Term
Sheet and the Commercial HVAC Enforcement Policy, DOE proposed
provisions in 10 CFR 429.134(dd)(2) \18\ regarding how DOE would assess
compliance for basic models that include individual models distributed
in commerce if DOE cannot obtain for testing individual models without
the components that are the basis of representation. 87 FR 53302,
53339. Specifically, DOE proposed that if a basic model includes
individual models with components listed at Table 6 to Paragraph
(a)(3)(v)(A) and DOE is not able to obtain an individual model with the
least number of those components within an OCMG (as defined in 10 CFR
429.43(a)(3) and discussed in section III.G.3.b of this final rule),
DOE may test any individual model within the OCMG. Id.
---------------------------------------------------------------------------
\18\ DOE notes that in the August 2022 NOPR, DOE referred to
this section as ``10 CFR 429.134(t)(2).'' Due to the publication of
other regulatory documents, DOE is now referring to this section as
``10 CFR 429.134(dd)(2).''
---------------------------------------------------------------------------
In response to the August 2022 NOPR, ClimateMaster stated that it
disagrees
[[Page 84221]]
with the provisions proposed in 10 CFR 429.134(dd)(2) in the August
2022 NOPR, stating that most WSHPs are built for specific orders based
on given configurations or options. (ClimateMaster, No. 22 at p. 12)
ClimateMaster commented that if DOE requires an individual model with
the lowest number of specific components, it may not be available to
test, and that the proposal would allow DOE testing with a model that
includes the specific component. (Id.) ClimateMaster recommended that
DOE instead allow a manufacturer to provide an individual model with
the least number of specific components within a specific and agreed-
upon timeframe (i.e., rather than testing a model that includes a
specific component). (Id.)
With regards to the comment from ClimateMaster, the provisions
proposed in the August 2022 NOPR at 10 CFR 429.134(dd)(2) specify that
DOE may test any individual model within the otherwise comparable model
group if DOE is not able to obtain an individual model with the least
number (which could be zero) of those components within the otherwise
comparable model group. DOE will attempt to obtain a model with the
least number of those components of specific components listed at Table
6 to Paragraph (a)(3)(v)(A). However, if DOE is unable to obtain such a
model, DOE must retain the option to conduct assessment testing on an
available model, and thus, in this final rule, DOE is adopting the
provisions from the NOPR as proposed, at 10 CFR 429.134(dd)(2).
H. Represented Values and Enforcement
1. Cooling Capacity
For WSHPs, cooling capacity determines equipment class, which in
turn determines the applicable energy conservation standard. 10 CFR
431.97. In the August 2022 NOPR, DOE noted that while cooling capacity
is a required represented value for WSHPs, DOE does not currently
specify provisions for WSHPs regarding how close the represented value
of cooling capacity must be to the tested or AEDM-simulated cooling
capacity, or whether DOE will use measured or certified cooling
capacity to determine equipment class for enforcement testing. 87 FR
53302, 53339. DOE proposed to add the following provisions regarding
cooling capacity for WSHPs: (1) a requirement that the represented
cooling capacity be between 95 percent and 100 percent of the tested or
AEDM-simulated cooling capacity; and (2) an enforcement provision
stating that DOE would use the mean of measured cooling capacity values
from testing, rather than the certified cooling capacity, to determine
the applicable standards. Id.
In response to the August 2022 NOPR, ClimateMaster commented that
it supports DOE's proposal for the published capacity to fall within 95
percent to 100 percent of the tested value or the value found through
the AEDM. (ClimateMaster, No. 22 at p. 12) WaterFurnace commented that
it saw no problem with DOE's proposal. (WaterFurnace, No. 20 at p. 10)
MIAQ commented that it supports the tolerance of 5 percent below the
rated/marked capacity, but not with the 100-percent limit. (MIAQ, No.
23 at p. 8) MIAQ stated that manufacturers must account for many
tolerances in their system, causing them to rate their units
conservatively, and this conservative rating will not impact customers
because the unit will perform better than advertised. (Id.)
In response to the comment from MIAQ, DOE notes that the proposed
cooling capacity provisions specify that the represented cooling
capacity be between 95 percent and 100 percent of the tested or AEDM-
simulated cooling capacity, which allows for conservative rating up to
5 percent--i.e., the represented cooling capacity may be 5 percent
lower than the tested or AEDM-simulated cooling capacity. MIAQ's
comment suggests MIAQ interpreted the proposal to mean the tested or
simulated capacity cannot exceed 100 percent of represented capacity,
which would not allow conservative ratings. However, DOE has concluded
that MIAQ's concern that conservative rating should be allowed is
addressed in the proposed provisions because the cooling capacity
provisions explicitly allow conservative ratings up to 5 percent.
Therefore, for the reasons discussed in the August 2022 NOPR and
previously in this section, DOE is adopting the cooling capacity
representation and enforcement provisions as proposed at 10 CFR
429.43(a)(3)(v)(B) and 10 CFR 429.134(dd)(1), respectively.
2. Enforcement of IEER
In the August 2022 NOPR, DOE proposed two options for determination
of IEER--``option 1'' based on testing at the EWTs specified in AHRI
340/360-2022 for determining IEER, and ``option 2'' based on testing at
the EWTs specified in ISO 13256-1:1998 and interpolating/extrapolating
performance to the EWTs specified in AHRI 340/360-2022. 87 FR 53302,
53339. For assessment or enforcement testing, DOE proposed provisions
in 10 CFR 429.134(t)(3) specifying that that the Department would
determine IEER according to the ``Option 1'' approach, unless the
manufacturer has specified that the ``Option 2'' approach should be
used for the purposes of enforcement, in which case the Department
would determine IEER according to the ``Option 2'' approach. Id.
As discussed in section III.E.1 of this final rule, DOE is not
adopting two methods for determining IEER, and is instead adopting a
single method for determining IEER by incorporating by reference AHRI
600-2023 into appendix C1. Because this final rule includes only one
method for determining IEER, the proposed enforcement provisions for
the method of determination of IEER are no longer applicable, and DOE
is not adopting the proposed provisions.
I. Test Procedure Costs
EPCA requires that the test procedures for commercial package air
conditioning and heating equipment, including WSHPs, be those generally
accepted industry testing procedures or rating procedures developed or
recognized by either AHRI or ASHRAE, as referenced in ASHRAE 90.1. (42
U.S.C. 6314(a)(4)(A)) Further, if such an industry test procedure is
amended, DOE must amend 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 an amended test procedure would not meet the
requirements in 42 U.S.C. 6314(a)(2)-(3) related to representative use
and test burden. (42 U.S.C. 6314(a)(4)(B)) EPCA also requires that, at
least once every 7 years, DOE evaluate test procedures for each type of
covered equipment, including WSHPs, to determine whether amended test
procedures would more accurately or fully comply with the requirements
for the test procedures to not be unduly burdensome to conduct and be
reasonably designed to produce test results that reflect energy
efficiency, energy use, and estimated operating costs during a
representative average use cycle. (42 U.S.C. 6314(a)(1)
In the August 2022 NOPR, DOE proposed to reorganize the current
test procedure in proposed appendix C and to adopt generally through
incorporation by reference the industry standard AHRI 340/360-2022 in
proposed appendix C1. 87 FR 53302, 53340. The proposed amended test
procedure in the proposed appendix C1 would rely on the IEER metric.
Id. DOE tentatively determined that the proposed amended test procedure
for WSHPs in appendix C1 would be
[[Page 84222]]
representative of an average use cycle and would not be unduly
burdensome for manufacturers to conduct. Id. DOE also proposed to
increase the scope of applicability of the test procedure to include
all WSHPs with full-load cooling capacity between 135,000 Btu/h and
760,000 Btu/h. Id. As part of the August 2022 NOPR, DOE presented
estimates of the test costs associated with these proposals. Id. DOE
requested comment on its understanding of the impact of the test
procedure proposals in this NOPR. Id.
In response to the August 2022 NOPR, ClimateMaster commented that
it qualifies as a small business under the Small Business
Administration (``SBA'') guidelines and that the extra burden to rate
through two programs, as would be required under AHRI 340/360-2022, is
too costly for small businesses. (ClimateMaster, No. 22 at pp. 13-14)
ClimateMaster recommended that DOE should instead use data created
through the national deviation to ISO 13256-1:1998 to interpolate per
the procedure given in AHRI 600. (Id. at p. 14)
WaterFurnace commented that that the test procedure proposed in the
August 2022 NOPR referencing AHRI 340/360 (including changes to ESP
requirements, flows, and entering air conditions) would approximately
double its testing and certification management labor and costs.
(WaterFurnace, No. 20 at p.10)
In this final rule DOE is relocating the current DOE test procedure
for WSHPs to appendix C without change. The test procedure adopted in
appendix C for measuring EER and COP will result in no change in
testing practices or burden.
As discussed in section III.D of this final rule, DOE is
incorporating by referencing AHRI 600-2023 into appendix C1 for
measuring the IEER and ACOP metrics. DOE has determined that the
amended test procedure is reasonably designed to produce results that
are representative of the energy efficiency of that covered equipment
during an average use cycle and is not unduly burdensome to conduct.
The use of appendix C1 will not be required until the compliance date
of any amended standards denominated in terms of IEER and ACOP, should
DOE adopt such standards. DOE has concluded that the incorporation by
reference AHRI 600-2023, the latest industry consensus test procedure
for WSHPs, renders moot any expressed concerns related to the costs
with rating to AHRI 340/360.
In this final rule, DOE estimates that the cost for units less than
135,000 Btu/h for third-party laboratory testing according to appendix
C1 for measuring IEER and ACOP to be $3,700 for single speed units,
$5,950 for two stage units, and $8,200 for variable speed units. The
difference in test cost is attributable to the varying number of tests
(i.e. 3, 6, or 9) required to determine IEER for units with different
compressor types. Additionally, DOE is increasing the scope of
applicability of the test procedure to include all WSHPs with full-load
cooling capacity between 135,000 Btu/h and 760,000 Btu/h. DOE estimates
the cost for third-party lab testing of large and very large WSHPs
according to the test procedure adopted in appendix C1 for measuring
IEER and ACOP to be $10,100 for single speed units, $15,500 for two
stage units, and $20,900 for variable speed units. DOE estimates a
substantially higher cost for larger WSHPs because they are generally
more difficult to set up due to size and larger units typically would
need to be set up in larger test chambers with more limited
availability.
As discussed in the August 2022 NOPR, in accordance with 10 CFR
429.70, WSHP manufacturers may elect to use AEDMs. 87 FR 53302, 53340.
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 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. In the August 2022 NOPR, DOE sought specific
feedback on the estimated costs to rate WSHP models with an AEDM. Id.
In response to the August 2022 NOPR, MIAQ agreed that AEDMs must be
acceptable but stated that the need for AEDMs to be representative
requires a lot of testing by manufacturers. (MIAQ, No. 23 at p. 9) MIAQ
commented that DOE's proposal to include WSHP's with cooling capacities
up to 760,000 Btu/h in scope increases the time and cost associated
with the testing required to validate the AEDM. (Id.) MIAQ recommended
that if an AEDM-rated unit were to fail a validation test, that only
the failed unit should be derated rather than the entire AEDM-rated
series. (Id.) MIAQ stated that the cost to test a full 30-ton WSHP
qualification is around $50,000-$60,000 per basic model group, and that
developing an AEDM model with sufficient trust would require as much as
$1 million in capital investment. (Id.)
DOE estimates the per-manufacturer cost to develop and validate an
AEDM to be used for all WSHP equipment with a cooling capacity less
than 135,000 Btu/h would be $12,050 for single stage units, $14,300 for
two stage units, and $16,550 for variable speed units. DOE estimates
the per-manufacturer cost to develop and validate an AEDM to be used
for all WSHPs with a cooling capacity between 135,000 Btu/h and 760,000
Btu/h would be $26,000 for single stage units, $31,400 for two stage
units, and $36,800 for variable speed units. DOE estimates an
additional cost of approximately $41 per basic model for determining
energy efficiency using the validated AEDM.\19\
---------------------------------------------------------------------------
\19\ DOE estimated initial costs to validate an AEDM assuming 80
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering technician wage of $41 per
hour plus the cost of third-party physical testing of two units per
validation class (as required in 10 CFR 429.70(c)(2)(iv)). DOE
estimated the additional per basic model cost to determine
efficiency using an AEDM assuming 1 hour per basic model at the cost
of an engineering technician wage of $41 per hour.
---------------------------------------------------------------------------
DOE disagrees with MIAQ's claims on the burden of AEDM development
for WSHPs with a cooling capacity greater than 135,000 Btu/h. As
discussed, based on quotes from third-party test laboratories, DOE
estimates a per-unit test cost to the amended test procedure adopted in
appendix C1 of $10,000-$21,000 for WSHPs with a cooling capacity
greater than 135,000 Btu/h. Per 10 CFR 429.70(c)(2), validation of an
AEDM requires testing a minimum of only two basic models. Based on
DOE's observation of the prevalence of use of AEDMs for WSHP and
similar equipment for which energy conservation standards currently
apply (i.e., for equipment with a cooling capacity no greater than
135,000 Btu/h), DOE expects most WSHP manufacturers already have AEDMs
for simulating WSHP performance. Further, as discussed in section
III.A.1 of this final rule, the manufacturer literature for all
identified model lines of WSHPs with a cooling capacity greater than
135,000 Btu/h includes efficiency representations that are explicitly
based on ISO 13256-1:1998, indicating that all manufacturers of this
equipment already have the capability to generate efficiency
representations for this equipment consistent with an industry
consensus test procedure for WSHPs.
Regarding the outcomes of failed DOE verification testing, in this
final rule, DOE is not amending its regulations for AEDM verification,
which are applicable to all equipment categories that may use AEDMs.
DOE notes that 10 CFR 429.70(c)(5)(viii) outlines required manufacturer
actions with regard to AEDM use if basic models certified with AEDMs
are determined to have invalid
[[Page 84223]]
ratings. Given that most WSHP manufacturers are AHRI members and that
DOE is incorporating by reference the prevailing industry test
procedure that was established for use in AHRI's certification program,
DOE expects that manufacturers will already be testing using AHRI 600-
2023 in the timeframe of any potential future energy conservation
standards in terms of IEER and ACOP. Based on this, DOE has determined
that the test procedure amendments adopted in this final rule are not
expected to increase the testing burden on WSHP manufacturers that are
AHRI members. For the minority of WSHP manufacturers that are not
members of AHRI, the test procedure amendments may have costs
associated with model re-rating, to the extent that the manufacturers
would not already be testing to the updated industry test procedure.
Additionally, DOE has determined that the test procedure amendments
will not require manufacturers to redesign any of the covered
equipment, will not require changes to how the equipment is
manufactured, and will not impact the utility of the equipment.
J. Effective and Compliance Dates
The effective date for the adopted test procedure amendments will
be 30 days after publication of this final rule in the Federal
Register. EPCA prescribes that, for the equipment at issue, all
representations of energy efficiency and energy use, including those
made on marketing materials and product labels, must be made in
accordance with an amended test procedure, beginning 360 days after
publication of this final rule in the Federal Register. (42 U.S.C.
6314(d)(1))
Starting 360 days after publication of a test procedure final rule
in the Federal Register, and prior to the compliance date of amended
standards for WSHPs that rely on IEER and ACOP, representations must be
based on the test procedure in appendix C. WSHPs are not required to be
tested according to the test procedure in appendix C1 (resulting in the
IEER and ACOP metrics) until the compliance date of amended energy
conservation standards denominated in terms of the IEER and ACOP
metrics, should DOE adopt such standards.
Any voluntary representations of IEER and ACOP made prior to the
compliance date of amended standards for WSHPs that rely on IEER and
ACOP must be based on the test procedure in appendix C1 starting 360
days after publication of such a test procedure final rule in the
Federal Register, and manufacturers may use appendix C1 to certify
compliance with any amended standards based on IEER and ACOP, if
adopted, prior to the applicable compliance date for those energy
conservation standards.
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866, 13563, and 14094
Executive Order (``E.O.'') 12866, ``Regulatory Planning and
Review,'' 58 FR 51735 (Oct. 4, 1993), as supplemented and reaffirmed by
E.O. 13563, ``Improving Regulation and Regulatory Review,'' 76 FR 3821
(Jan. 21, 2011) and amended by E.O. 14094, ``Modernizing Regulatory
Review,'' 88 FR 21879 (April 11, 2023), requires agencies, to the
extent permitted by law, to: (1) propose or adopt a regulation only
upon a reasoned determination that its benefits justify its costs
(recognizing that some benefits and costs are difficult to quantify);
(2) tailor regulations to impose the least burden on society,
consistent with obtaining regulatory objectives, taking into account,
among other things, and to the extent practicable, the costs of
cumulative regulations; (3) select, in choosing among alternative
regulatory approaches, those approaches that maximize net benefits
(including potential economic, environmental, public health and safety,
and other advantages; distributive impacts; and equity); (4) to the
extent feasible, specify performance objectives, rather than specifying
the behavior or manner of compliance that regulated entities must
adopt; and (5) identify and assess available alternatives to direct
regulation, including providing economic incentives to encourage the
desired behavior, such as user fees or marketable permits, or providing
information upon which choices can be made by the public. DOE
emphasizes as well that E.O. 13563 requires agencies to use the best
available techniques to quantify anticipated present and future
benefits and costs as accurately as possible. In its guidance, the
Office of Information and Regulatory Affairs (``OIRA'') in the Office
of Management and Budget (``OMB'') has emphasized that such techniques
may include identifying changing future compliance costs that might
result from technological innovation or anticipated behavioral changes.
For the reasons stated in this preamble, this final regulatory action
is consistent with these principles.
Section 6(a) of E.O. 12866 also requires agencies to submit
``significant regulatory actions'' to OIRA for review. OIRA has
determined that this final regulatory action does not constitute a
``significant regulatory action'' under section 3(f) of E.O. 12866.
Accordingly, this action was not submitted to OIRA for review under
E.O. 12866.
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (``RFA'') (5 U.S.C. 601 et seq.)
requires preparation of a final regulatory flexibility analysis
(``FRFA'') 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 E.O. 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: www.energy.gov/gc/office-general-counsel. DOE
reviewed this final rule to amend the test procedure for WSHPs under
the provisions of the RFA and the policies and procedures published on
February 19, 2003.
As part of the August 2022 NOPR, DOE conducted its initial
regulatory flexibility analysis (``IRFA''). The following sections
outline DOE's determination that this final rule does not have a
``significant economic impact on a substantial number of small
entities,'' and that the preparation of a FRFA is not warranted.
DOE is amending the test procedure for WSHPs to satisfy its
statutory obligations under EPCA. (42 U.S.C. 6314(a)(1)(A))
In this final rule, DOE is establishing new appendices C and C1 to
subpart F of part 431. The current DOE test procedure for WSHPs is
relocated to appendix C without change. The amended test procedure for
WSHPs is established in a new appendix C1, which includes the following
amended test procedure requirements for WSHPs for measuring the updated
efficiency metrics: (1) IEER for WSHPs using the methods from AHRI 600-
2023; and (2) ACOP using the methods specified in AHRI 600-2023. Use of
the amended test procedure in appendix C1 will not be required until
such time as compliance is required with amended energy conservation
standards for WSHPs denominated in terms of IEER
[[Page 84224]]
and ACOP, should DOE adopt such standards.
Additionally, DOE is expanding the scope of the test procedure to
include WSHPs with capacities between 135,000 and 760,000 Btu/h, as
well as specifying the components that must be present for testing and
amending certain provisions related to representations and enforcement
in 10 CFR part 429.
DOE uses the Small Business Administration (``SBA'') small business
size standards to determine whether manufacturers qualify as ``small
businesses,'' which are listed by the North American Industry
Classification System (``NAICS'').\20\ The SBA considers a business
entity to be small business if, together with its affiliates, it
employs less than a threshold number of workers specified in 13 CFR
part 121. WSHP manufacturers, who produce the equipment covered by this
rule, are classified under NAICS code 333415, ``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. This employee threshold includes all
employees in a business's parent company and any other subsidiaries.
---------------------------------------------------------------------------
\20\ 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 July 16, 2021).
---------------------------------------------------------------------------
DOE utilized the California Energy Commission's Modernized
Appliance Efficiency Database System (``MAEDbS'') \21\ and the DOE's
Certification Compliance Database (``CCD'') \22\ in identifying
manufacturers. DOE screened out private labelers because original
equipment manufacturers (``OEMs'') would likely be responsible for any
costs associated with testing to the amended test procedure. As a
result of this inquiry, DOE identified a total of 25 OEMs of WSHPs in
the United States affected by this rulemaking. DOE screened out
companies that do not meet the definition of a ``small business'' or
are foreign owned without substantive domestic operations. DOE used
subscription-based business information tools to determine headcount
and revenue of each business. Of the 25 OEMs of WSHPs, DOE identified 6
as small, domestic manufacturers.
---------------------------------------------------------------------------
\21\ MAEDbS is available at www.cacertappliances.energy.ca.gov/Pages/Search/AdvancedSearch.aspx (Last accessed Dec. 1, 2021).
\22\ Certified equipment in the CCD are listed by product class
and can be accessed at www.regulations.doe.gov/certification-data/
(Last accessed May 1, 2023).
---------------------------------------------------------------------------
Of the 6 small, domestic manufacturers identified, all certify
their WSHP models in the AHRI Certification Directory for WSHPs.
AHRI has published a new industry test standard for WSHPs, titled
AHRI Standard 600, ``2023 Standard for Performance Rating of Water/
Brine to Air Heat Pump Equipment'' (``AHRI 600-2023''). DOE presumes
AHRI's certification program will require rating based on AHRI 600-2023
to develop the IEER and ACOP metrics. As a result, the test procedure
amendments adopted in this final rule will not add any additional
testing burden to manufacturers that already certify WSHPs to AHRI's
certification program. Accordingly, DOE does not expect that the
identified small business manufacturers, all of whom participate in
AHRI's certification program, would see increased testing costs as a
result of this rulemaking.
Additionally, DOE notes these test procedure amendments will only
affect voluntary representations. There is no existing energy
conservation standard that requires manufacturer to certify to WSHP
efficiency in terms of IEER and ACOP to DOE. Certification based on
IEER and ACOP would only be required if and when DOE establishes energy
conservation standards based on those metrics for WSHPs.
Therefore, for the reasons stated in the preceding paragraphs, DOE
concludes and certifies that the cost effects accruing from this test
procedure final rule would not have a ``significant economic impact on
a substantial number of small entities,'' and that the preparation of a
FRFA is not warranted. DOE has submitted a certification and supporting
statement of factual basis to the Chief Counsel for Advocacy of the
Small Business Administration for review under 5 U.S.C. 605(b).
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of WSHPs must certify to DOE that their products
comply with any applicable energy conservation standards. To certify
compliance, manufacturers must first obtain test data for their
products according to the DOE test procedures, including any amendments
adopted for those test procedures. DOE has established regulations for
the certification and recordkeeping requirements for all covered
consumer products and commercial equipment, including WSHPs. (See
generally 10 CFR part 429.) The collection-of-information requirement
for the certification and recordkeeping is subject to review and
approval by OMB under the Paperwork Reduction Act (``PRA''). This
requirement has been approved by OMB under OMB control number 1910-
1400. Public reporting burden for the certification is estimated to
average 35 hours per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information.
DOE is not amending the certification or reporting requirements for
WSHPs in this final rule. Instead, DOE may consider proposals to amend
the certification requirements and reporting for WSHPs under a separate
rulemaking regarding appliance and equipment certification. DOE will
address changes to OMB Control Number 1910-1400 at that time, as
necessary.
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
D. Review Under the National Environmental Policy Act of 1969
In this final rule, DOE establishes test procedure amendments that
it expects will be used to develop and implement future energy
conservation standards for WSHPs. DOE has determined that this rule
falls into a class of actions that are categorically excluded from
review under the National Environmental Policy Act of 1969 (42 U.S.C.
4321 et seq.) and DOE's implementing regulations at 10 CFR part 1021.
Specifically, DOE has determined that adopting test procedures for
measuring energy efficiency of consumer products and industrial
equipment is consistent with activities identified in 10 CFR part 1021,
appendix A to subpart D, A5 and A6. Accordingly, neither an
environmental assessment nor an environmental impact statement is
required.
E. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 4,
1999), imposes certain requirements on agencies formulating and
implementing policies or regulations that preempt State law or that
have federalism implications. The Executive order requires agencies to
examine the constitutional and statutory authority supporting any
action that would limit the policymaking discretion of the States and
to carefully assess the necessity for such actions. The Executive order
also requires agencies to have an accountable process to ensure
[[Page 84225]]
meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.
On March 14, 2000, DOE published a statement of policy describing the
intergovernmental consultation process it will follow in the
development of such regulations. 65 FR 13735. DOE examined this final
rule and determined that it will not have a substantial direct effect
on the States, on the relationship between the national government and
the States, or on the distribution of power and responsibilities among
the various levels of government. EPCA governs and prescribes Federal
preemption of State regulations as to energy conservation for the
products that are the subject of this final rule. States can petition
DOE for exemption from such preemption to the extent, and based on
criteria, set forth in EPCA. (42 U.S.C. 6316(a) and 42 U.S.C. 6316(b);
42 U.S.C. 6297(d)) No further action is required by Executive Order
13132.
F. Review Under Executive Order 12988
Regarding the review of existing regulations and the promulgation
of new regulations, section 3(a) of Executive Order 12988, ``Civil
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal
agencies the general duty to adhere to the following requirements: (1)
eliminate drafting errors and ambiguity; (2) write regulations to
minimize litigation; (3) provide a clear legal standard for affected
conduct rather than a general standard; and (4) promote simplification
and burden reduction. Section 3(b) of Executive Order 12988
specifically requires that Executive agencies make every reasonable
effort to ensure that the regulation (1) clearly specifies the
preemptive effect, if any; (2) clearly specifies any effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct while promoting simplification and burden reduction;
(4) specifies the retroactive effect, if any; (5) adequately defines
key terms; and (6) addresses other important issues affecting clarity
and general draftsmanship under any guidelines issued by the Attorney
General. Section 3(c) of Executive Order 12988 requires Executive
agencies to review regulations in light of applicable standards in
sections 3(a) and 3(b) to determine whether they are met or it is
unreasonable to meet one or more of them. DOE has completed the
required review and determined that, to the extent permitted by law,
this final rule meets the relevant standards of Executive Order 12988.
G. Review Under the Unfunded Mandates Reform Act of 1995
Title II of the Unfunded Mandates Reform Act of 1995 (``UMRA'')
requires each Federal agency to assess the effects of Federal
regulatory actions on State, local, and Tribal governments and the
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531).
For a regulatory action resulting in a rule that may cause the
expenditure by State, local, and Tribal governments, in the aggregate,
or by the private sector of $100 million or more in any one year
(adjusted annually for inflation), section 202 of UMRA requires a
Federal agency to publish a written statement that estimates the
resulting costs, benefits, and other effects on the national economy.
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to
develop an effective process to permit timely input by elected officers
of State, local, and Tribal governments on a proposed ``significant
intergovernmental mandate,'' and requires an agency plan for giving
notice and opportunity for timely input to potentially affected small
governments before establishing any requirements that might
significantly or uniquely affect small governments. On March 18, 1997,
DOE published a statement of policy on its process for
intergovernmental consultation under UMRA. 62 FR 12820; also available
at www.energy.gov/gc/office-general-counsel. DOE examined this final
rule according to UMRA and its statement of policy and determined that
the rule contains neither an intergovernmental mandate, nor a mandate
that may result in the expenditure of $100 million or more in any year,
so these requirements do not apply.
H. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family
Policymaking Assessment for any rule that may affect family well-being.
This final rule will not have any impact on the autonomy or integrity
of the family as an institution. Accordingly, DOE has concluded that it
is not necessary to prepare a Family Policymaking Assessment.
I. Review Under Executive Order 12630
DOE has determined, under Executive Order 12630, ``Governmental
Actions and Interference with Constitutionally Protected Property
Rights'' 53 FR 8859 (March 18, 1988), that this regulation will not
result in any takings that might require compensation under the Fifth
Amendment to the U.S. Constitution.
J. Review Under Treasury and General Government Appropriations Act,
2001
Section 515 of the Treasury and General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most
disseminations of information to the public under guidelines
established by each agency pursuant to general guidelines issued by
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). Pursuant
to OMB Memorandum M-19-15, Improving Implementation of the Information
Quality Act (April 24, 2019), DOE published updated guidelines which
are available at www.energy.gov/sites/prod/files/2019/12/f70/DOE%20Final%20Updated%20IQA%20Guidelines%20Dec%202019.pdf. DOE has
reviewed this final rule under the OMB and DOE guidelines and has
concluded that it is consistent with applicable policies in those
guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355
(May 22, 2001), requires Federal agencies to prepare and submit to OMB,
a Statement of Energy Effects for any significant energy action. A
``significant energy action'' is defined as any action by an agency
that promulgated or is expected to lead to promulgation of a final
rule, and that (1) is a significant regulatory action under Executive
Order 12866, or any successor order; and (2) is likely to have a
significant adverse effect on the supply, distribution, or use of
energy; or (3) is designated by the Administrator of OIRA as a
significant energy action. For any significant energy action, the
agency must give a detailed statement of any adverse effects on energy
supply, distribution, or use if the regulation is implemented, and of
reasonable alternatives to the action and their expected benefits on
energy supply, distribution, and use.
This regulatory action is not a significant regulatory action under
Executive Order 12866. Moreover, it would not have a significant
adverse effect on the supply, distribution, or use of energy, nor has
it been designated as a significant energy action by the Administrator
of OIRA. Therefore, it is not a significant energy action, and,
accordingly, DOE has not prepared a Statement of Energy Effects.
[[Page 84226]]
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 modifications to the test procedure for WSHPs adopted in this
final rule incorporates testing methods contained in certain sections
of the following commercial standards: AHRI 600-2023, ANSI/ASHRAE 37-
2009, ISO 13256-1:1998, and Melinder 2010. DOE has evaluated these
standards and is unable to conclude whether the standards 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 has consulted with both the
Attorney General and the Chairman of the FTC about the impact on
competition of using the methods contained in these standards and has
received no comments objecting to their use.
M. Congressional Notification
As required by 5 U.S.C. 801, DOE will report to Congress on the
promulgation of this rule before its effective date. The report will
state that it has been determined that the rule is not a ``major rule''
as defined by 5 U.S.C. 804(2).
N. Description of Materials Incorporated by Reference
In this final rule, DOE incorporates by reference the following
test standards and reference document:
AHRI 600-2023 is an industry accepted test procedure for measuring
the performance of water source heat pumps. AHRI 600-2023 is available
on AHRI's website at: https://www.ahrinet.org/search-standards/ahri-600-i-p-performance-rating-waterbrine-air-heat-pump-equipment.
ANSI/ASHRAE 37-2009 is an industry-accepted test procedure for
measuring the performance of electrically driven unitary air-
conditioning and heat pump equipment. ANSI/ASHRAE 37-2009 is available
on ANSI's website at: webstore.ansi.org/RecordDetail.aspx?sku=ANSI%2FASHRAE+Standard+37-2009.
Errata sheet for ANSI/ASHRAE Standard 37-2009 dated March 27, 2019,
specifies all of the corrections to ANSI/ASHRAE 37-2009 identified from
the date of publication through March 27, 2019. Errata sheet for ANSI/
ASHRAE Standard 37-2009 is available on ASHRAE's website at: https://www.ashrae.org/technical-resources/standards-and-guidelines/standards-errata.
Melinder 2010 is a reference booklet with properties of secondary
working fluids for indirect heating and cooling systems used in air
conditioning, heat pumps, and other applications. Melinder 2010 is
available from the International Institute of Refrigeration website at:
www.iifiir.org.
ISO 13256-1:1998 is an industry-accepted test procedure for
measuring the performance of specific water-source heat pump equipment.
ISO 13256-1:1998 is available on ISO's website at: www.iso.org/store.html.
The following standards are currently approved for the sections in
which they appear in this final rule: AHRI 210/240-2008 and AHRI 340/
360-2007.
V. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this final
rule.
List of Subjects
10 CFR Part 429
Administrative practice and procedure, Confidential business
information, Energy conservation, Household appliances, Imports,
Incorporation by reference, Intergovernmental relations, Reporting and
recordkeeping requirements, Small businesses.
10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Energy conservation test procedures, Incorporation by
reference, Reporting and recordkeeping requirements.
Signing Authority
This document of the Department of Energy was signed on November
17, 2023, by Jeffrey Marootian, Principal Deputy 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 November 20, 2023.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
For the reasons stated in the preamble, DOE amends 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. 429.4 by:
0
a. Redesignating paragraphs (c)(4) through (6) as paragraphs (c)(5)
through (7); and
0
b. Adding new paragraph (c)(4).
The addition reads as follows:
Sec. 429.4 Materials incorporated by reference.
* * * * *
(c) * * *
(4) AHRI Standard 600-2023 (I-P) (``AHRI 600-2023''), 2023 Standard
for Performance Rating of Water/Brine to Air Heat Pump Equipment,
approved September 11, 2023; IBR approved for Sec. 429.43.
* * * * *
0
3. Amend Sec. 429.43 by adding paragraph (a)(3)(v) to read as follows:
Sec. 429.43 Commercial heating, ventilating, air conditioning (HVAC)
equipment.
(a) * * *
(3) * * *
(v) Water-Source Heat Pumps. When certifying to standards in terms
of IEER and ACOP, the following provisions apply.
(A) Individual model selection:
(1) Representations for a basic model must be based on the least
efficient individual model(s) distributed in commerce among all
otherwise comparable model groups comprising
[[Page 84227]]
the basic model, except as provided in paragraph (a)(3)(v)(A)(2) of
this section for individual models that include components listed in
table 6 to paragraph (a)(3)(v)(A) of this section. For the purpose of
this paragraph (a)(3)(v)(A)(1), ``otherwise comparable model group''
means a group of individual models distributed in commerce within the
basic model that do not differ in components that affect energy
consumption as measured according to the applicable test procedure
specified at 10 CFR 431.96 other than those listed in table 6 to
paragraph (a)(3)(v)(A) of this section. An otherwise comparable model
group may include individual models distributed in commerce with any
combination of the components listed in table 6 (or none of the
components listed in table 6) to paragraph (a)(3)(v)(A) of this
section. An otherwise comparable model group may consist of only one
individual model.
(2) For a basic model that includes individual models distributed
in commerce with components listed in table 6 to paragraph (a)(3)(v)(A)
of this section, the requirements for determining representations apply
only to the individual model(s) of a specific otherwise comparable
model group distributed in commerce with the least number (which could
be zero) of components listed in table 6 to paragraph (a)(3)(v)(A) of
this section included in individual models of the group. Testing under
this paragraph shall be consistent with any component-specific test
provisions specified in section 3 of appendix C1 to subpart F of 10 CFR
part 431.
Table 6 to Paragraph (a)(3)(v)(A)--Specific Components for Water Source
Heat Pumps
------------------------------------------------------------------------
Component Description
------------------------------------------------------------------------
Air Economizers................... An automatic system that enables a
cooling system to supply outdoor
air to reduce or eliminate the need
for mechanical cooling during mild
or cold weather.
Condenser Pumps/Valves/Fittings... Additional components in the water
circuit for water control or
filtering.
Condenser Water Reheat............ A heat exchanger located downstream
of the indoor coil that heats the
supply air during cooling operation
using water from the condenser coil
in order to increase the ratio of
moisture removal to cooling
capacity provided by the equipment.
Desiccant Dehumidification An assembly that reduces the
Components. moisture content of the supply air
through moisture transfer with
solid or liquid desiccants.
Desuperheater..................... A heat exchanger located downstream
of the compressor on the high-
pressure vapor line that moves heat
to an external source, such as
potable water.
Fire/Smoke/Isolation Dampers...... A damper assembly including means to
open and close the damper mounted
at the supply or return duct
opening of the equipment.
Grill Options..................... Special grills used to direct
airflow in unique applications
(such as up and away from a rear
wall).
Indirect/Direct Evaporative Water is used indirectly or directly
Cooling of Ventilation Air. to cool ventilation air. In a
direct system the water is
introduced directly into the
ventilation air and in an indirect
system the water is evaporated in
secondary air stream and the heat
is removed through a heat
exchanger.
Non-Standard High-Static Indoor The standard indoor fan motor is the
Fan Motors. motor specified in the
manufacturer's installation
instructions for testing and shall
be distributed in commerce as part
of a particular model. A non-
standard high-static motor is 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.
For a non-standard high-static
indoor fan motor(s) to be
considered a specific component for
a basic model (and thus subject to
the provisions of paragraph
(a)(3)(v)(A)(2) of this section),
the following 2 provisions must be
met:
1. Non-standard high-static indoor
fan motor(s) must meet the minimum
allowable efficiency determined per
section D.4.1 of AHRI 600-2023
(incorporated by reference, see
Sec. 429.4) for non-standard high-
static indoor fan motors, or per
section D.4.2 of AHRI 600-2023 for
non-standard high-static indoor
integrated fan and motor
combinations.
2. If the standard indoor fan motor
can vary fan speed through control
system adjustment of motor speed,
all non-standard high-static indoor
fan motors must also allow speed
control (including with the use of
a variable-frequency drive).
Powered Exhaust/Powered Return Air A powered exhaust fan is a fan that
Fans. transfers directly to the outside a
portion of the building air that is
returning to the unit, rather than
allowing it to recirculate to the
indoor coil and back to the
building. A powered return fan is a
fan that draws building air into
the equipment.
Process Heat Recovery/Reclaim A heat exchanger located inside the
Coils/Thermal Storage. unit that conditions the
equipment's supply air using energy
transferred from an external source
using a vapor, gas, or liquid.
Refrigerant Reheat Coils.......... A heat exchanger located downstream
of the indoor coil that heats the
supply air during cooling operation
using high-pressure refrigerant in
order to increase the ratio of
moisture removal to cooling
capacity provided by the equipment.
Sound Traps/Sound Attenuators..... An assembly of structures through
which the supply air passes before
leaving the equipment or through
which the return air from the
building passes immediately after
entering the equipment for which
the sound insertion loss is at
least 6 dB for the 125 Hz octave
band frequency range.
Steam/Hydronic Heat Coils......... Coils used to provide supplemental
heating.
Ventilation Energy Recovery System An assembly that preconditions
(VERS). outdoor 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.
Waterside Economizer.............. A heat exchanger located upstream of
the indoor coil that conditions the
supply air when system water loop
conditions are favorable so as not
to utilize compressor operation.
------------------------------------------------------------------------
(B) The represented value of cooling capacity must be between 95
percent and 100 percent of the mean of the cooling capacities measured
for the units in the sample selected as described in paragraph
(a)(1)(ii) of this section, or between 95 percent and 100 percent of
the cooling capacity output simulated by the AEDM as described in
paragraph (a)(2) of this section.
* * * * *
[[Page 84228]]
0
4. Amend Sec. 429.134 by adding paragraph (dd) to read as follows:
Sec. 429.134 Product-specific enforcement provisions.
* * * * *
(dd) Water-Source Heat Pumps. The following provisions apply for
assessment and enforcement testing of models subject to standards in
terms of IEER and ACOP.
(1) Verification of Cooling Capacity. The cooling capacity of each
tested unit of the basic model will be measured pursuant to the test
requirements of appendix C1 to subpart F of 10 CFR part 431. The mean
of the measurements will be used to determine the applicable standards
for purposes of compliance.
(2) Specific Components. If a basic model includes individual
models with components listed at table 6 to Sec. 429.43(a)(3)(v)(A)
and DOE is not able to obtain an individual model with the least number
(which could be zero) of those components within an otherwise
comparable model group (as defined in Sec. 429.43(a)(3)(v)(A)(1)), DOE
may test any individual model within the otherwise comparable model
group.
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
5. 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
6. Amend Sec. 431.92 by:
0
a. Adding in alphabetical order a definition of ``Applied Coefficient
of performance, or ACOP''; and
0
b. Revising the definitions of ``Integrated energy efficiency ratio, or
IEER,'' and ``Water-source heat pump''.
The addition and revisions read as follows:
Sec. 431.92 Definitions concerning commercial air conditioners and
heat pumps.
* * * * *
Applied Coefficient of performance, or ACOP means the ratio of the
heating capacity to the power input, including system pump power, for
water-source heat pumps. ACOP is expressed in watts per watt and
determined according to appendix C1 of this subpart.
* * * * *
Integrated energy efficiency ratio, or IEER, means a weighted
average calculation of mechanical cooling EERs determined for four load
levels and corresponding rating conditions, expressed in Btu/watt-hour.
IEER is measured:
(1) Per appendix A to this subpart for air-cooled small (>=65,000
Btu/h), large, and very large commercial package air conditioning and
heating equipment;
(2) Per appendix C1 to this subpart for water-source heat pumps;
(3) Per appendix D1 to this subpart for variable refrigerant flow
multi-split air conditioners and heat pumps (other than air-cooled with
rated cooling capacity less than 65,000 Btu/h); and
(4) Per appendix G1 to this subpart for single package vertical air
conditioners and single package vertical heat pumps.
* * * * *
Water-source heat pump means commercial package air-conditioning
and heating equipment that is a single-phase or three-phase reverse-
cycle heat pump that uses a circulating water loop as the heat source
for heating and as the heat sink for cooling. The main components are a
compressor, refrigerant-to-water heat exchanger, refrigerant-to-air
heat exchanger, refrigerant expansion devices, refrigerant reversing
valve, and indoor fan (except that coil-only units do not include an
indoor fan). Such equipment includes, but is not limited to, water-to-
air water-loop heat pumps.
0
7. Amend Sec. 431.95 by:
0
a. Redesignating paragraphs (b)(6) through (10) as paragraphs (b)(7)
through (11);
0
b. Adding new paragraph (b)(6);
0
c. In paragraph (c)(2), removing the text ``B, D1'' and adding, in its
place, the text ``B, C1, D1'';
0
d. In paragraph (c)(3), removing the text ``appendix D1'' and adding,
in its place, the text ``appendices C1 and D1'';
0
e. Revising paragraph (d); and
0
f. Adding paragraph (e).
The additions and revision read as follows:
Sec. 431.95 Materials incorporated by reference.
* * * * *
(b) * * *
(6) AHRI Standard 600-2023 (I-P) (``AHRI 600-2023''), 2023 Standard
for Performance Rating of Water/Brine to Air Heat Pump Equipment, AHRI-
approved September 11, 2023; IBR approved for appendix C1 to this
subpart.
* * * * *
(d) IIR. International Institute of Refrigeration, 177 Boulevard
Malesherbes 75017 Paris, France; +33 (0)1 42 27 32 35; www.iifiir.org.
(1) Properties of Secondary Working Fluids for Indirect Systems,
including Section 2.3 Errata Sheet, Melinder, published 2010
(``Melinder 2010''), IBR approved for appendix C1 to this subpart.
(2) [Reserved]
(e) ISO. International Organization for Standardization, Chemin de
Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland; +41 22 749 01
11; www.iso.org/store.html.
(1) ISO Standard 13256-1 (``ISO 13256-1:1998''), ``Water-source
heat pumps--Testing and rating for performance--Part 1: Water-to-air
and brine-to-air heat pumps,'' approved 1998; IBR approved for appendix
C to this subpart.
(2) [Reserved]
* * * * *
0
8. Amend Sec. 431.96 by revising table 1 to paragraph (b) to read as
follows:
Sec. 431.96 Uniform test method for the measurement of energy
efficiency of commercial air conditioners and heat pumps.
* * * * *
(b) * * *
Table 1 to Paragraph (b)--Test Procedures for Commercial Air Conditioners and Heat Pumps
--------------------------------------------------------------------------------------------------------------------------------------------------------
Additional test procedure
Cooling capacity or Energy efficiency Use tests, provisions as indicated
Equipment type Category moisture removal descriptor conditions, and in the listed paragraphs
capacity \2\ procedures in of this section
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small Commercial Package Air- Air-Cooled, 3-Phase, <65,000 Btu/h........ SEER and HSPF........ Appendix F to this None.
Conditioning and Heating AC and HP. subpart \3\.
Equipment.
[[Page 84229]]
SEER2 and HSPF2...... Appendix F1 to this None.
subpart \3\.
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 (e).
Evaporatively-Cooled \1\ (omit section
AC. 6.5).
EER.................. AHRI 340/360-2007 Paragraphs (c) and (e).
\1\ (omit section
6.3).
Water-Source HP...... <135,000 Btu/h....... EER and COP.......... Appendix C to this None.
subpart \3\.
Water-Source HP...... <135,000 Btu/h....... IEER and ACOP........ Appendix C1 to this None.
subpart \3\.
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 <240,000 Btu/h. subpart.
Equipment.
Water-Cooled and >=135,000 Btu/h and EER.................. AHRI 340/360-2007 Paragraphs (c) and (e).
Evaporatively-Cooled <240,000 Btu/h. \1\ (omit section
AC. 6.3).
Water-Source HP...... >=135,000 Btu/h and EER and COP.......... Appendix C to this None.
<240,000 Btu/h. subpart \3\.
Water-Source HP...... >=135,000 Btu/h and IEER and ACOP........ Appendix C1 to this None.
<240,000 Btu/h. subpart \3\.
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 <760,000 Btu/h. subpart.
Equipment.
Water-Cooled and >=240,000 Btu/h and EER.................. AHRI 340/360-2007 Paragraphs (c) and (e).
Evaporatively-Cooled <760,000 Btu/h. \1\ (omit section
AC. 6.3).
Water-Source HP...... >=240,000 Btu/h and EER and COP.......... Appendix C to this None.
<760,000 Btu/h. subpart \3\.
Water-Source HP...... >=240,000 Btu/h and IEER and ACOP........ Appendix C1 to this None.
<760,000 Btu/h. subpart \3\.
Packaged Terminal Air Conditioners AC and HP............ <760,000 Btu/h....... EER and COP.......... Paragraph (g) of Paragraphs (c), (e), and
and Heat Pumps. this section. (g).
Computer Room Air Conditioners.... AC................... <760,000 Btu/h....... SCOP................. Appendix E to this None.
subpart \3\.
<760,000 Btu/h or NSenCOP.............. Appendix E1 to this None.
<930,000 Btu/h \4\. subpart \3\.
Variable Refrigerant Flow Multi- AC................... <65,000 Btu/h (3- SEER................. Appendix F to this None.
split Systems. phase). subpart \3\.
SEER2................ Appendix F1 to this None.
subpart \3\.
Variable Refrigerant Flow Multi- HP................... <65,000 Btu/h (3- SEER and HSPF........ Appendix F to this None.
split Systems, Air-cooled. phase). subpart \3\.
SEER2 and HSPF2...... Appendix F1 to this None.
subpart \3\.
Variable Refrigerant Flow Multi- AC and HP............ >=65,000 Btu/h and EER and COP.......... Appendix D to this None.
split Systems, Air-cooled. <760,000 Btu/h. subpart \3\.
IEER and COP......... Appendix D1 to this None.
subpart \3\.
Variable Refrigerant Flow Multi- HP................... <760,000 Btu/h....... EER and COP.......... Appendix D to this None.
split Systems, Water-source. subpart \3\.
IEER and COP......... Appendix D1 to this None.
subpart \3\.
Single Package Vertical Air AC and HP............ <760,000 Btu/h....... EER and COP.......... Appendix G to this None.
Conditioners and Single Package subpart \3\.
Vertical Heat Pumps.
[[Page 84230]]
EER, IEER, and COP... Appendix G1 to this None.
subpart \3\.
Direct Expansion-Dedicated Outdoor All.................. <324 lbs. of moisture ISMRE2 and ISCOP2.... Appendix B to this None.
Air Systems. removal/hr. subpart.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Incorporated by reference; see Sec. 431.95.
\2\ Moisture removal capacity applies only to direct expansion-dedicated outdoor air systems.
\3\ For equipment with multiple appendices listed in this Table 1, consult the notes at the beginning of those appendices to determine the applicable
appendix to use for testing.
\4\ For upflow ducted and downflow floor-mounted computer room air conditioners, the test procedure in appendix E1 of this subpart applies to equipment
with net sensible cooling capacity less than 930,000 Btu/h. For all other configurations of computer room air conditioners, the test procedure in
appendix E1 applies to equipment with net sensible cooling capacity less than 760,000 Btu/h.
* * * * *
0
9. Add appendix C to subpart F of part 431 to read as follows:
Appendix C to Subpart F of Part 431--Uniform Test Method for Measuring
the Energy Consumption of Water-Source Heat Pumps
Note: Manufacturers must use the results of testing under this
appendix to determine compliance with the relevant standard at Sec.
431.97 as that standard appeared in the January 1, 2023 edition of
10 CFR parts 200-499. Specifically, representations must be based on
testing according to either this appendix or 10 CFR 431.96 as it
appeared in the 10 CFR parts 200-499 edition revised as of January
1, 2023.
Starting on November 29, 2024, voluntary representations with
respect to energy use or efficiency of water-source heat pumps with
cooling capacity greater than or equal to 135,000 Btu/h and less
than 760,000 Btu/h must be based on testing according to this
appendix. Manufacturers may also use this appendix to make voluntary
representations with respect to energy use or efficiency prior to
November 29, 2024.
Starting on November 29, 2024, voluntary representations with
respect to the integrated energy efficiency ratio (IEER) and applied
coefficient of performance (ACOP) of water-source heat pumps must be
based on testing according to appendix C1 of this subpart.
Manufacturers may also use appendix C1 to make voluntary
representations with respect to IEER and ACOP prior to November 29,
2024.
Starting on the compliance date for any amended energy
conservation standards for water-source heat pumps based on IEER and
ACOP, any representations, including compliance certifications, made
with respect to the energy use or energy efficiency of water-source
heat pumps must be based on testing according to appendix C1 of this
subpart.
Manufacturers may also certify compliance with any amended
energy conservation standards for water-source heat pumps based on
IEER and ACOP prior to the applicable compliance date for those
standards, and those compliance certifications must be based on
testing according to appendix C1 of this subpart.
1. Incorporation by Reference
DOE incorporated by reference in Sec. 431.95, the entire standard
for ISO 13256-1:1998. To the extent there is a conflict between the
terms or provisions of a referenced industry standard and this
appendix, the appendix provisions control.
2. General
Determine the energy efficiency ratio (EER) and coefficient of
performance (COP) in accordance with ISO 13256-1:1998.
Section 3 of this appendix provides additional instructions for
determining EER and COP.
3. Additional Provisions for Equipment Set-Up
The only additional specifications that may be used in setting up
the basic model for testing are those set forth in the installation and
operation manual shipped with the unit. Each unit should be set up for
test in accordance with the manufacturer installation and operation
manuals. Sections 3.1 through 3.2 of this appendix provide
specifications for addressing key information typically found in the
installation and operation manuals.
3.1. If a manufacturer specifies a range of superheat, sub-cooling,
and/or refrigerant pressure in its installation and operation manual
for a given basic model, any value(s) within that range may be used to
determine refrigerant charge or mass of refrigerant, unless the
manufacturer clearly specifies a rating value in its installation and
operation manual, in which case the specified rating value must be
used.
3.2. The airflow rate used for testing must be that set forth in
the installation and operation manuals being shipped to the commercial
customer with the basic model and clearly identified as that used to
generate the DOE performance ratings. If a rated airflow value for
testing is not clearly identified, a value of 400 standard cubic feet
per minute (scfm) per ton must be used.
0
10. Add appendix C1 to subpart F of part 431 to read as follows:
Appendix C1 to Subpart F of Part 431--Uniform Test Method for Measuring
the Energy Consumption of Water-Source Heat Pumps
Note: Prior to the compliance date of amended standards for
water-source heat pumps that rely on integrated energy efficiency
ratio (IEER) and applied coefficient of performance (ACOP) published
after January 1, 2023, representations with respect to the energy
use or energy efficiency of water-source heat pumps, including
compliance certifications, must be based on testing according to
appendix C of this subpart.
Starting on November 29, 2024, voluntary representations with
respect to the IEER and ACOP of water-source heat pumps must be
based on testing according to this appendix. Manufacturers may also
use this appendix to make voluntary representations with respect to
IEER and ACOP prior to November 29, 2024.
Starting on the compliance date for any amended energy
conservation standards for water-source heat pumps based on IEER and
ACOP, any representations, including compliance certifications, made
with respect to the energy use or energy efficiency of water-source
heat pumps must be based on testing according to this appendix.
Manufacturers may also certify compliance with any amended
energy conservation standards for water-source heat pumps based on
IEER and ACOP prior to the applicable compliance date for those
standards, and
[[Page 84231]]
those compliance certifications must be based on testing according
to this appendix.
1. Incorporation by Reference
DOE incorporated by reference in Sec. 431.95 the entire standards
for AHRI 600-2023, ANSI/ASHRAE 37-2009 (as corrected by the Errata
sheet for ANSI/ASHRAE 37-2009), and Melinder 2010. However, certain
enumerated provisions of AHRI 600-2023 and ASHRAE 37-2009, as listed in
this section 1, are inapplicable.
To the extent there is a conflict between the terms or provisions
of a referenced industry standard and the CFR, the CFR provisions
control.
1.1. AHRI 600-2023
(a) Section 1 Purpose is inapplicable,
(b) Section 2 Scope is inapplicable,
(c) The following subsections of section 3 Definitions are
inapplicable:
(1) 3.2.1 (Air Economizer),
(2) 3.2.3 (Barometric Relief Dampers),
(3) 3.2.4 (Basic Model),
(4) 3.2.5 (Coated Coils),
(5) 3.2.6 (Coefficients of Performance),
(6) 3.2.9 (Condenser Pump/Valves/Fittings),
(7) 3.2.10 (Condenser Water Reheat),
(8) 3.2.13 (Desiccant Dehumidification Components),
(9) 3.2.14 (Desuperheater),
(10) 3.2.15.1 (Energy Efficiency Ratio),
(11) 3.2.16 (Evaporative Cooling of Ventilation Air),
(12) 3.2.17 (Fire/Smoke/Isolation Dampers),
(13) 3.2.19 (Fresh Air Dampers),
(14) 3.2.21 (Grill Options),
(15) 3.2.23 (High-effectiveness Indoor Air Filtration),
(16) 3.2.24 (Hot Gas Bypass),
(17) 3.2.27 (Integrated Energy Efficiency Ratio),
(18) 3.2.28 (Low-static Heat Pump),
(19) 3.2.35 (Power Correction Capacitors),
(20) 3.2.36 (Powered Exhaust Air Fan),
(21) 3.2.37 (Powered Return Air Fan),
(22) 3.2.38 (Process Heat Recovery/Reclaim Coils/Thermal Storage),
(23) 3.2.40 (Published Rating),
(24) 3.2.42 (Refrigerant Reheat Coils),
(25) 3.2.43 (Single Package Heat Pumps),
(26) 3.2.44 (Sound Traps/Sound Attenuators),
(27) 3.2.45 (Split System Heat Pump),
(28) 3.2.51 (Steam/Hydronic Heat Coils),
(29) 3.2.53 (UV Lights),
(30) 3.2.54 (Ventilation Energy Recovery System),
(31) 3.2.55 (Water/Brine to Air Heat Pump Equipment), and
(32) 3.2.56 (Waterside Economizer),
(d) The following subsections of section 6 Rating Requirements are
inapplicable:
(1) 6.5 (Residential Cooling Capacity and Efficiency),
(2) 6.6 (Residential Heating Capacity and Efficiency),
(3) 6.7 (Test Data vs Computer Simulation),
(4) 6.8 (Rounding and Precision),
(5) 6.9 (Uncertainty), and
(6) 6.10 (Verification Testing),
(e) Section 7 Minimum Data Requirements for Published Ratings is
inapplicable
(f) Section 8 Operating Requirements is inapplicable,
(g) Section 9 Marking and Nameplate Data is inapplicable,
(h) Section 10 Conformance Conditions is inapplicable,
(i) Appendix B References--Informative is inapplicable,
(j) Sections D.1 (Purpose), D.2 (Configuration Requirements), and
D.3 (Optional System Features) of Appendix D Unit Configuration For
Standard Efficiency Determination--Normative are inapplicable, and
(k) Appendix F Example of Determination of Fan and Motor Efficiency
for Non-standard Integrated Indoor Fan and Motors--Informative is
inapplicable.
1.2. ANSI/ASHRAE 37-2009 (Even if Corrected by the Errata Sheet)
(a) Section 1 Purpose is inapplicable.
(b) Section 2 Scope is inapplicable.
(c) Section 4 Classification is inapplicable.
2. General
Determine integrated energy efficiency ratio (IEER) and heating
applied coefficient of performance (ACOP) in accordance with this
appendix and the applicable sections of AHRI 600-2023, ANSI/ASHRAE 37-
2009, and Melinder 2010. Representations of AEER, EER, and COP may
optionally be made.
Section 3 of this appendix provides additional instructions for
testing. In cases where there is a conflict, the language of this
appendix takes highest precedence, followed by AHRI 600-2023, followed
by ANSI/ASHRAE 37-2009. Any subsequent amendment to a referenced
document by the standard-setting organization will not affect the test
procedure in this appendix, unless and until the test procedure is
amended by DOE. Material is incorporated as it exists on the date of
the approval, and a notification of any change in the incorporation
must be published in the Federal Register.
3. Setup and Test Provisions for Specific Components
When testing a water-source heat pump that includes any of the
features listed in table 1 to this appendix, test in accordance with
the setup and test provisions specified in table 1 to this appendix.
Table 1 to Appendix C1--Setup and Test Provisions for Specific
Components
------------------------------------------------------------------------
Setup and test
Component Description provisions
------------------------------------------------------------------------
Air Economizers............. An automatic system For any air
that enables a economizer that is
cooling system to factory-installed,
supply outdoor air place the
to reduce or economizer in the
eliminate the need 100 percent return
for mechanical position and close
cooling during mild and seal the
or cold weather. outside air dampers
for testing. For
any modular air
economizer shipped
with the unit but
not factory-
installed, do not
install the
economizer for
testing.
Barometric Relief Dampers... An assembly with For any barometric
dampers and means relief dampers that
to automatically are factory-
set the damper installed, close
position in a and seal the
closed position and dampers for
one or more open testing. For any
positions to allow modular barometric
venting directly to relief dampers
the outside a shipped with the
portion of the unit but not
building air that factory-installed,
is returning to the do not install the
unit, rather than dampers for
allowing it to testing.
recirculate to the
indoor coil and
back to the
building.
Desiccant Dehumidification An assembly that Disable desiccant
Components. reduces the dehumidification
moisture content of components for
the supply air testing.
through moisture
transfer with solid
or liquid
desiccants.
[[Page 84232]]
Fire/Smoke/Isolation Dampers A damper assembly For any fire/smoke/
including means to isolation dampers
open and close the that are factory-
damper mounted at installed, set the
the supply or dampers in the
return duct opening fully open position
of the equipment. for testing. For
any modular fire/
smoke/isolation
dampers shipped
with the unit but
not factory-
installed, do not
install the dampers
for testing.
Fresh Air Dampers........... An assembly with For any fresh air
dampers and means dampers that are
to set the damper factory-installed,
position in a close and seal the
closed and one open dampers for
position to allow testing. For any
air to be drawn modular fresh air
into the equipment dampers shipped
when the indoor fan with the unit but
is operating. not factory-
installed, do not
install the dampers
for testing.
Power Correction Capacitors. A capacitor that Remove power
increases the power correction
factor measured at capacitors for
the line connection testing.
to the equipment.
Process Heat recovery/ A heat exchanger Disconnect the heat
Reclaim Coils/Thermal located inside the exchanger from its
Storage. unit that heat source for
conditions the testing.
equipment's supply
air using energy
transferred from an
external source
using a vapor, gas,
or liquid.
Refrigerant Reheat Coils.... A heat exchanger De-activate
located downstream refrigerant reheat
of the indoor coil coils for testing
that heats the so as to provide
supply air during the minimum (none
cooling operation if possible) reheat
using high-pressure achievable by the
refrigerant in system controls.
order to increase
the ratio of
moisture removal to
cooling capacity
provided by the
equipment.
Steam/Hydronic Heat Coils... Coils used to Test with steam/
provide hydronic heat coils
supplemental in place but
heating. providing no heat.
UV Lights................... A lighting fixture Turn off UV lights
and lamp mounted so for testing.
that it shines
light on the indoor
coil, that emits
ultraviolet light
to inhibit growth
of organisms on the
indoor coil
surfaces, the
condensate drip
pan, and/other
locations within
the equipment.
Ventilation Energy Recovery An assembly that For any VERS that is
System (VERS). preconditions factory-installed,
outdoor air place the VERS in
entering the the 100 percent
equipment through return position and
direct or indirect close and seal the
thermal and/or outside air dampers
moisture exchange and exhaust air
with the exhaust dampers for
air, which is testing, and do not
defined as the energize any VERS
building air being subcomponents
exhausted to the (e.g., energy
outside from the recovery wheel
equipment. motors). For any
VERS module shipped
with the unit but
not factory-
installed, do not
install the VERS
for testing.
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[FR Doc. 2023-25921 Filed 12-1-23; 8:45 am]
BILLING CODE 6450-01-P
