[Federal Register Volume 89, Number 67 (Friday, April 5, 2024)]
[Proposed Rules]
[Pages 24206-24266]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-04784]



[[Page 24205]]

Vol. 89

Friday,

No. 67

April 5, 2024

Part III





Department of Energy





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10 CFR Parts 429 and 430





Energy Conservation Program: Test Procedure for Central Air 
Conditioners and Heat Pumps; Proposed Rule

  Federal Register / Vol. 89 , No. 67 / Friday, April 5, 2024 / 
Proposed Rules  

[[Page 24206]]


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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 430

[EERE-2022-BT-TP-0028]
RIN 1904-AF49


Energy Conservation Program: Test Procedure for Central Air 
Conditioners and Heat Pumps

AGENCY: Office of Energy Efficiency and Renewable Energy, Department of 
Energy.

ACTION: Notice of proposed rulemaking and announcement of public 
meeting.

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SUMMARY: The U.S. Department of Energy (``DOE'') proposes to amend the 
Federal test procedure for central air conditioners and heat pumps 
(``CAC/HPs'') to incorporate by reference the latest versions of the 
applicable industry standards. Specifically, DOE proposes: to amend the 
current test procedure for CAC/HPs (``appendix M1'') for measuring the 
current cooling and heating metrics--seasonal energy efficiency ratio 2 
(``SEER2'') and heating seasonal performance factor 2 (``HSPF2''), 
respectively; and to establish a new test procedure (``appendix M2'') 
for CAC/HPs that would adopt two new metrics--seasonal cooling and off-
mode rating efficiency (``SCORE'') and seasonal heating and off-mode 
rating efficiency (``SHORE''). Testing to the SCORE and SHORE metrics 
would not be required until such time as compliance is required with 
any amended energy conservation standard based on the new metrics. 
Additionally, DOE proposes to amend certain provisions of DOE's 
regulations related to representations and enforcement for CAC/HPs. DOE 
welcomes written comments from the public on any subject within the 
scope of this document (including relevant topics not raised in this 
proposal), as well as the submission of data and other relevant 
information.

DATES: 
    Comments: DOE will accept comments, data, and information regarding 
this proposal no later than June 4, 2024. See section V, ``Public 
Participation,'' for details.
    Meeting: DOE will hold a public meeting via webinar on Thursday, 
April 25, 2024, from 1:00 p.m. to 4:00 p.m. See section V, ``Public 
Participation,'' for webinar registration information, participant 
instructions, and information about the capabilities available to 
webinar participants.

ADDRESSES: Interested persons are encouraged to submit comments using 
the Federal eRulemaking Portal at www.regulations.gov under docket 
number EERE-2022-BT-TP-0028. Follow the instructions for submitting 
comments. Alternatively, interested persons may submit comments, 
identified by docket number EERE-2022-BT-TP-0028, by any of the 
following methods:
    (1) Email: [email protected]. Include the docket 
number EERE-2022-BT-TP-0028 in the subject line of the message.
    (2) Postal Mail: Appliance and Equipment Standards Program, U.S. 
Department of Energy, Building Technologies Office, Mailstop EE-5B, 
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: 
(202) 287-1445. If possible, please submit all items on a compact disc 
(``CD''), in which case it is not necessary to include printed copies.
    (3) Hand Delivery/Courier: Appliance and Equipment Standards 
Program, U.S. Department of Energy, Building Technologies Office, 950 
L'Enfant Plaza SW, 6th Floor, Washington, DC 20024. Telephone: (202) 
287-1445. If possible, please submit all items on a CD, in which case 
it is not necessary to include printed copies.
    No telefacsimiles (``faxes'') will be accepted. For detailed 
instructions on submitting comments and additional information on this 
process, see section V of this document.
    Docket: The docket for this activity, which includes Federal 
Register notices, public meeting attendee lists and transcripts (if a 
public meeting is held), 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 information that is exempt from public disclosure.
    The docket web page can be found at www.regulations.gov/docket/EERE-2022-BT-TP-0028. The docket web page contains instructions on how 
to access all documents, including public comments, in the docket. See 
section V for information on how to submit comments through 
www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: 
    Mr. Lucas Adin, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, EE-2J, 
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: 
(202) 287-5904. Email: [email protected].
    Mr. Pete Cochran, U.S. Department of Energy, Office of the General 
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121. 
Telephone: (202) 586-9496. Email: [email protected].
    For further information on how to submit a comment, review other 
public comments and the docket, or participate in a public meeting (if 
one is held), contact the Appliance and Equipment Standards Program 
staff at (202) 287-1445 or by email: 
[email protected].

SUPPLEMENTARY INFORMATION: DOE proposes to maintain previously approved 
incorporations by reference and incorporate by reference the following 
industry standards into 10 CFR parts 429 and 430:
    AHRI 210/240-202X, 202X Standard for Performance Rating of Unitary 
Air-Conditioning & Air-Source Heat Pump Equipment (``AHRI 210/240-202X 
Draft''). AHRI 210/240-202X Draft is in draft form and this draft was 
announced for public review on November 16, 2023.\1\ DOE references 
this version for the purposes of drafting this Notice of Proposed 
Rulemaking (``NOPR''). If this industry test standard is formally 
adopted, DOE intends to incorporate by reference the final published 
version of AHRI 210/240, not the current draft version, in DOE's 
subsequent test procedure final rule, unless there are substantive 
changes between the draft and final versions, in which case DOE may 
adopt the substance of the AHRI 210/240-202X Draft or provide 
additional opportunity for comment on the changes to the industry 
consensus standard.
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    \1\ Public review of AHRI 210/240-202X Draft was announced in 
the November 16, 2023 AHRI Update here: http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html.
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    AHRI 1600-202X, 202X Standard for Performance Rating of Unitary 
Air-Conditioning & Air-Source Heat Pump Equipment (``AHRI 1600-202X 
Draft''). AHRI 1600-202X Draft is in draft form and this draft was 
announced for public review on November 16, 2023.\2\ DOE references 
this version for the purposes of drafting this NOPR. If this industry 
test standard is formally adopted, DOE intends to incorporate by 
reference the final published version of AHRI 1600, not the current 
draft version, in DOE's subsequent test procedure final rule, unless 
there are substantive changes between the draft and published versions, 
in which case DOE may adopt the substance of the AHRI 1600-202X

[[Page 24207]]

Draft or provide additional opportunity for comment on the changes to 
the industry consensus standard.
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    \2\ Public review of AHRI 1600-202X Draft was also announced in 
the November 16, 2023 AHRI Update here: http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html.
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    Copies of the AHRI 210/240-202X Draft and AHRI 1600-202X Draft are 
available in the docket for this proposed rulemaking for review.
    ANSI/ASHRAE Standard 16-2016, Method of Testing for Rating Room Air 
Conditioners, Packaged Terminal Air Conditioners, and Packaged Terminal 
Heat Pumps for Cooling and Heating Capacity, ANSI approved November 1, 
2016, (``ANSI/ASHRAE 16-2016'').
    ANSI/ASHRAE Standard 37-2009, Methods of Testing for Rating 
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, 
ANSI approved June 25, 2009, (``ANSI/ASHRAE 37-2009'').
    ANSI/ASHRAE 116-2010, Methods of Testing for Rating Seasonal 
Efficiency of Unitary Air Conditioners and Heat Pumps, ANSI approved 
February 24, 2010, (``ASHRAE 116-2010'').
    Copies of ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-
2010 can be purchased from the American Society of Heating, 
Refrigerating, and Air-Conditioning Engineers (``ASHRAE'') website at 
www.ashrae.org/resources--publications.
    See section IV.M of this document for further discussion of these 
standards.

Table of Contents

I. Authority and Background
    A. Authority
    B. Background
II. Synopsis of the Notice of Proposed Rulemaking
III. Discussion
    A. Scope of Applicability
    B. Definitions
    C. Updates to Industry Standards
    1. AHRI 210/240-202X Draft
    2. AHRI 1600-202X Draft
    3. ANSI/ASHRAE 37-2009
    4. ANSI/ASHRAE 16-2016
    5. ANSI/ASHRAE 116-2010
    D. Proposed CAC/HP Test Procedure
    E. Efficiency Metrics
    1. Metrics Applicable to Appendix M1
    2. Metrics Applicable to Appendix M2
    F. Near-Term Changes in the CAC/HP Test Procedure
    1. Representativeness of Fixed Speed Testing for Variable Speed 
(VS) Systems
    (a) Background
    (b) Comments Received
    (c) Commenter Conclusions Regarding Load-Based Testing
    (d) DOE's Conclusion and Approach
    (e) CVP Proposal
    2. Low-Temperature Heating Performance
    (a) CCHP Definition
    (b) Mandatory H4 Heating Tests for CCHPs
    (c) Heating Load Line and Sizing for CCHPs
    (d) Cold Climate Heating Metric of Interest, COPpeak
    3. Cut-out and Cut-in Temperature Certification
    4. Low-Static Single-Split Blower-Coil System Definition and 
Testing Provisions
    5. Mandatory Constant Circulation Systems
    6. Dual-Fuel Systems
    7. Provisions for Outdoor Units With No Match
    8. Inlet and Outlet Duct Configurations
    9. Heat Comfort Controllers
    G. Long-Term Changes in the CAC Test Procedure
    1. Power Consumption of Auxiliary Components
    (a) General Comments About Standby and Off Mode Power 
Consumption
    (b) Adjustment of Off Mode Power Consumption for Number of 
Compressors, System Capacity, and Variable Speed and Weighting of 
Off-Mode Test Power Measurements
    (c) Crankcase Heaters
    (d) Shoulder-Season Fan Power Consumption
    (e) Accounting for Auxiliary Components' Power Consumption
    2. Impact of Defrost on Performance
    (a) Demand Defrost Credit
    (b) Supplementary Heat Usage
    3. Updates to Building Load Lines and Temperature Bin Hours
    4. Default Fan Power Coefficients for Coil-Only Systems
    5. Indoor Ambient Test Conditions for Cooling Mode Tests
    6. Air Flow Limits To Address Inadequate Dehumidification
    H. General Comments Received in Response to the January 2023 RFI
    I. Represented Values
    1. Calculating Represented Values for the Federal Trade 
Commission
    2. Off-Mode Power
    3. AEDM Tolerance for SCORE and SHORE
    4. Removal of the AEDM Exception for Split-System CAC/HPs
    J. Enforcement Provisions
    1. Verifying Cut-Out and Cut-In Temperatures
    2. Controls Verification Procedure
    K. Test Procedure Costs and Impact
    1. Appendix M1
    2. Appendix M2
    L. Compliance Date and Waivers
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Orders 12866, 13563, and 14094
    B. Review Under the Regulatory Flexibility Act
    1. Description of Reasons Why Action Is Being Considered
    2. Objectives of, and Legal Basis for, Rule
    3. Description and Estimated Number of Small Entities Regulated
    4. Description and Estimate of Compliance Requirements
    (a) Cost and Compliance Associated With Appendix M1
    (b) Cost and Compliance Associated With Appendix M2
    5. Duplication, Overlap, and Conflict With Other Rules and 
Regulations
    6. Significant Alternatives to the Rule
    C. Review Under the Paperwork Reduction Act of 1995
    D. Review Under the National Environmental Policy Act of 1969
    E. Review Under Executive Order 13132
    F. Review Under Executive Order 12988
    G. Review Under the Unfunded Mandates Reform Act of 1995
    H. Review Under the Treasury and General Government 
Appropriations Act, 1999
    I. Review Under Executive Order 12630
    J. Review Under Treasury and General Government Appropriations 
Act, 2001
    K. Review Under Executive Order 13211
    L. Review Under Section 32 of the Federal Energy Administration 
Act of 1974
    M. Description of Materials Incorporated by Reference
V. Public Participation
    A. Participation in the Webinar
    B. Procedure for Submitting Prepared General Statements for 
Distribution
    C. Conduct of the Public Meeting
    D. Submission of Comments
    E. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary

I. Authority and Background

    Central air conditioners (``CACs'') and central air conditioning 
heat pumps (``HPs'') (collectively, ``CAC/HPs'') are included in the 
list of ``covered products'' for which DOE is authorized to establish 
and amend energy conservation standards and test procedures. (42 U.S.C. 
6292(a)(3)) DOE's test procedures for CAC/HPs are currently prescribed 
at 10 CFR part 430, subpart B, appendix M1 (``appendix M1''). The 
following sections discuss DOE's authority to establish and amend test 
procedures for CAC/HPs and relevant background information regarding 
DOE's consideration of test procedures for this product.

A. Authority

    The Energy Policy and Conservation Act, Pub. L. 94-163, as amended 
(``EPCA''),\3\ 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 B of EPCA \4\ established the Energy 
Conservation Program for Consumer Products Other Than Automobiles, 
which sets forth a variety of provisions designed to improve energy 
efficiency. These products include CAC/HPs, the subject of this 
document. (42 U.S.C. 6292(a)(3))
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    \3\ All references to EPCA in this document refer to the statute 
as amended through the Energy Act of 2020, Public Law 116-260 (Dec. 
27, 2020), which reflect the last statutory amendments that impact 
Parts A and A-1 of EPCA.
    \4\ For editorial reasons, upon codification in the U.S. Code, 
Part B was redesignated Part A.
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    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

[[Page 24208]]

procedures. Relevant provisions of EPCA specifically include 
definitions (42 U.S.C. 6291), test procedures (42 U.S.C. 6293), 
labeling provisions (42 U.S.C. 6294), energy conservation standards (42 
U.S.C. 6295), and the authority to require information and reports from 
manufacturers (42 U.S.C. 6296).
    The Federal testing requirements consist of test procedures that 
manufacturers of covered products must use as the basis for: (1) 
certifying to DOE that their products comply with the applicable energy 
conservation standards adopted pursuant to EPCA (42 U.S.C. 6295(s)), 
and (2) making other representations about the efficiency of those 
consumer products (42 U.S.C. 6293(c)). Similarly, DOE must use these 
test procedures to determine whether the products comply with relevant 
standards promulgated under EPCA. (42 U.S.C. 6295(s))
    Federal energy efficiency requirements for covered products 
established under EPCA generally supersede State laws and regulations 
concerning energy conservation testing, labeling, and standards. (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. 6297(d))
    Under 42 U.S.C. 6293, EPCA sets forth the criteria and procedures 
DOE must follow when prescribing or amending test procedures for 
covered products. EPCA requires that any test procedures prescribed or 
amended under this section be reasonably designed to produce test 
results which measure energy efficiency, energy use, or estimated 
annual operating cost of a covered product during a representative 
average use cycle or period of use and not be unduly burdensome to 
conduct. (42 U.S.C. 6293(b)(3))
    EPCA also requires that, at least once every 7 years, DOE evaluate 
test procedures for each type of covered product, including CAC/HPs, 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 or period of 
use. (42 U.S.C. 6293(b)(1)(A))
    If the Secretary determines, on her own behalf or in response to a 
petition by any interested person, that a test procedure should be 
prescribed or amended, the Secretary shall promptly publish in the 
Federal Register proposed test procedures and afford interested persons 
an opportunity to present oral and written data, views, and arguments 
with respect to such procedures. The comment period on a proposed rule 
to amend a test procedure shall be at least 60 days and may not exceed 
270 days. In prescribing or amending a test procedure, the Secretary 
shall take into account such information as the Secretary determines 
relevant to such procedure, including technological developments 
relating to energy use or energy efficiency of the type (or class) of 
covered products involved. (42 U.S.C. 6293(b)(2)). If DOE determines 
that test procedure revisions are not appropriate, DOE must publish its 
determination not to amend the test procedures. (42 U.S.C. 
6293(b)(1)(A)(ii))
    In addition, EPCA requires that DOE amend its test procedures for 
all covered products to integrate measures of standby mode and off mode 
energy consumption. (42 U.S.C. 6295(gg)(2)(A)) Standby mode and off 
mode energy consumption must be incorporated into the overall energy 
efficiency, energy consumption, or other energy descriptor for each 
covered product unless the current test procedures already account for 
and incorporate standby and off mode energy consumption or such 
integration is technically infeasible. If an integrated test procedure 
is technically infeasible, DOE must prescribe a separate standby mode 
and off mode energy use test procedure for the covered product, if 
technically feasible. (42 U.S.C. 6295(gg)(2)(A)(ii)) Any such amendment 
must consider the most current versions of the International 
Electrotechnical Commission (``IEC'') Standard 62301 \5\ and IEC 
Standard 62087 \6\ as applicable. (42 U.S.C. 6295(gg)(2)(A))
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    \5\ IEC 62301, Household electrical appliances--Measurement of 
standby power (Edition 2.0, 2011-01).
    \6\ IEC 62087, Audio, video and related equipment--Methods of 
measurement for power consumption (Edition 1.0, Parts 1-6: 2015, 
Part 7: 2018).
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    DOE is publishing this NOPR in satisfaction of the 7-year review 
requirement specified in EPCA. (42 U.S.C. 6293(b)(1)(A))

B. Background

    On January 5, 2017, DOE published a final rule regarding the 
Federal test procedures for CAC/HPs. 82 FR 1426 (``January 2017 Final 
Rule''). The January 2017 Final Rule amended the current test procedure 
at that time, 10 CFR part 430, subpart B, appendix M (``appendix M'') 
and established appendix M1, use of which was required beginning 
January 1, 2023, for any representations, including compliance 
certifications, made with respect to the energy use or efficiency of 
CAC/HPs. Appendix M provides for the measurement of the cooling and 
heating performance of CAC/HPs using the seasonal energy efficiency 
ratio (``SEER'') metric and heating seasonal performance factor 
(``HSPF'') metric, respectively. Appendix M1 specifies a revised SEER 
metric (i.e., ``SEER2'') and a revised HSPF metric (i.e., ``HSPF2'').
    On October 25, 2022, DOE published a final rule to address limited-
scope amendments to the existing test procedures for CAC/HPs in 
appendix M1. 87 FR 64550 (``October 2022 Final Rule''). The October 
2022 Final Rule provided changes to improve the functionality of 
appendix M1 to address the issues identified in test procedure waivers, 
improve representativeness, and correct typographical issues raised by 
commenters. Id. at 87 FR 64551. In the October 2022 Final Rule, DOE 
noted that several commenters indicated the need for test procedure 
amendments beyond the scope of the rulemaking. Id. at 87 FR 64554-
64555. DOE received comments recommending consideration of load-based 
testing methods, controls validation (particularly for variable speed 
systems), amended metrics, amended definitions, and expansion of test 
methods to capture low-temperature heating performance for heat pumps. 
Id. In its response to these comments, DOE noted that it had initiated 
that rulemaking not as a comprehensive revision that would satisfy the 
7-year lookback requirements (see 42 U.S.C. 6293(b)(1)(A)), but to 
address a limited set of known issues, including those that have been 
raised through the test procedure waiver process. 87 FR 64554. DOE, 
however, also acknowledged that a future rulemaking may more 
comprehensively address the issues raised by the commenters. Id.
    On January 24, 2023, DOE published in the Federal Register a 
request for information (``RFI'') regarding the need for amendments to 
the test procedures for CAC/HPs, including the need for amendments to 
address the issues raised by commenters in the previous rulemaking, in 
satisfaction of the 7-year review requirements specified in EPCA. 88 FR 
4091 (``January 2023 RFI''). In the January 2023 RFI, DOE requested 
comments, information, and data about a number of issues, and 
considered these issues in two separate categories: (1) the 
consideration of load-based testing methodologies under development by 
various organizations and whether certain aspects of these 
methodologies might be adopted into

[[Page 24209]]

the DOE test procedure; and (2) issues with the current appendix M1 
test procedure that may or may not still be relevant if or when load-
based concepts are adopted in the DOE test procedure. Id. at 88 FR 
4092-4093.
    DOE received comments in response to the January 2023 RFI from the 
interested parties listed in Table I.1.

           Table I.1--List of Commenters With Written Submissions in Response to the January 2023 RFI
----------------------------------------------------------------------------------------------------------------
                                                                       Comment No. in
               Commenter(s)                  Reference in this NOPR      the docket          Commenter type
----------------------------------------------------------------------------------------------------------------
Air-Conditioning, Heating, and             AHRI......................              14  Trade Association.
 Refrigeration Institute.
Appliance Standards Awareness Project,     Joint Advocates...........               8  Efficiency Organizations
 American Council for an Energy-Efficient                                               and Consumer Advocacy
 Economy, Consumer Federation of America,                                               Organizations.
 and National Consumer Law Center.
British Columbian Hydro and Power          BC Hydro..................              15  Utility.
 Authority.
Pacific Gas and Electric Company, San      CA IOUs...................              10  Utilities.
 Diego Gas and Electric, and Southern
 California Edison; collectively, the
 California Investor-Owned Utilities.
Carrier Global Corporation...............  Carrier...................               5  Manufacturer.
CoilPod LLC..............................  CoilPod...................               4  Service Provider.
Daikin Comfort Technologies North America  Daikin....................              16  Manufacturer.
 Inc.
Lennox International Inc.................  Lennox....................               6  Manufacturer.
National Comfort Products................  NCP.......................               7  Manufacturer.
Northwest Energy Efficiency Alliance.....  NEEA......................              13  Efficiency Organization.
New York State Energy Research and         NYSERDA...................               9  State Agency.
 Development Authority.
Rheem Manufacturing Company..............  Rheem.....................              12  Manufacturer.
Samsung HVAC.............................  Samsung...................              11  Manufacturer.
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    A parenthetical reference at the end of a comment quotation or 
paraphrase provides the location of the item in the public record.\7\
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    \7\ The parenthetical reference provides a reference for 
information located in the docket of DOE's rulemaking to develop 
test procedures for CAC/HPs. (Docket No. EERE-2022-BT-TP-0028, 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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    In response to the January 2023 RFI, DOE received multiple comments 
regarding the energy conservation standards for CAC/HPs. Comments 
regarding energy conservation standards are outside the scope of 
consideration for this test procedure rulemaking and are not addressed 
in this NOPR. Topics related to energy conservation standards for CAC/
HPs would be addressed in a separate rulemaking process.

II. Synopsis of the Notice of Proposed Rulemaking

    In this NOPR, DOE proposes to update its test procedures for CAC/
HPs by: (1) updating the reference in the Federal test procedure at 
appendix M1 to the most recent draft version of the AHRI Standard 210/
240 industry test procedure, AHRI 210/240-202X Draft, for measuring 
SEER2 and HSPF2; and (2) establishing a new test procedure at 10 CFR 
part 430, subpart B, appendix M2 (``appendix M2'') that references the 
draft new industry test procedure, AHRI 1600-202X Draft, for measuring 
new efficiency metrics, seasonal cooling and off-mode rating efficiency 
(``SCORE''), and seasonal heating and off-mode rating efficiency 
(``SHORE'').
    If AHRI 210/240-202X Draft and AHRI 1600-202X Draft are finalized 
and formally adopted, DOE intends to incorporate by reference the final 
published version of AHRI 210/240 and AHRI 1600 in DOE's subsequent 
test procedure final rule.
    To implement the proposed changes, DOE proposes: (1) to amend 
appendix M1 to incorporate by reference AHRI 210/240-202X Draft for 
CAC/HPs, while maintaining the current efficiency metrics; and (2) to 
add a new appendix M2 to subpart F of 10 CFR part 430 to incorporate by 
reference AHRI 1600-202X Draft, which introduces new efficiency 
metrics, SCORE and SHORE. DOE would list appendix M2 as the applicable 
test method for CAC/HPs for any standards denominated in terms of SCORE 
and SHORE. Use of appendix M2 would not be required until such time as 
compliance is required with any amended energy conservation standard 
based on the new metrics, should DOE adopt such standards. After the 
date on which compliance with appendix M2 would be required, appendix 
M1 would no longer be required as part of the Federal test procedure. 
DOE is also proposing to amend certain provisions within DOE's 
regulations for representation and enforcement consistent with the 
proposed test procedure amendments.
    Table II.1 summarizes the current DOE test procedure for CAC/HPs, 
DOE's proposed changes to that test procedure, and the reason for each 
proposed change.

   Table II.1--Summary of Changes in Proposed Appendix M1 and Proposed Appendix M2 Test Procedures Relative to
                                             Current Test Procedure
----------------------------------------------------------------------------------------------------------------
                                         Proposed appendix M1     Proposed appendix M2
      Current DOE test procedure            test procedure           test procedure            Attribution
----------------------------------------------------------------------------------------------------------------
Incorporates by reference AHRI 210/    Incorporates by          Incorporates by          Updates to the
 240-2008.                              reference AHRI 210/240-  reference AHRI 1600-     applicable industry
                                        202X Draft.              202X Draft.              test procedures.
Includes provisions for determining    Maintains provisions     Includes provisions for  Updates to the
 SEER2, HSPF2, EER2, and PW,OFF.        for determining SEER2,   determining SCORE and    applicable industry
                                        HPSF2, EER2, and         SHORE and maintains      test procedures.
                                        PW,OFF.                  provisions for
                                                                 determining EER2.

[[Page 24210]]

 
Includes certain CAC/HP provisions     Includes provisions to   Includes provisions to   Improve
 regarding determination of             remove the alternative   remove the AEDM          representativeness of
 represented values in 10 CFR 429.16.   efficiency               exception for split-     test procedure.
                                        determination method     systems, to extend the
                                        (``AEDM'') exception     AEDM tolerance
                                        for split-systems in     requirement to SCORE
                                        10 CFR 429.16.           and SHORE, and to no
                                                                 longer require
                                                                 representations of the
                                                                 PW,OFF metric in 10
                                                                 CFR 429.16.
Does not include certain CAC/HP-       Includes CAC/HP-         Includes CAC/HP-         Clarify how DOE will
 specific enforcement provisions in     specific enforcement     specific enforcement     conduct enforcement
 10 CFR 429.134(k).                     provisions regarding     provisions regarding     testing.
                                        verification of cut-     verification of cut-
                                        out and cut-in           out and cut-in
                                        temperatures and a       temperatures and a
                                        controls verification    controls verification
                                        procedure.               procedure.
----------------------------------------------------------------------------------------------------------------

    DOE has tentatively determined that the proposed amendments to the 
CAC/HP test procedures in appendix M1 and the proposed appendix M2 
would not be unduly burdensome. Furthermore, DOE has tentatively 
determined that the proposed amendments to appendix M1, if made final, 
would not alter the measured efficiency of CAC/HPs or require retesting 
or recertification solely as a result of DOE's adoption of the proposed 
amendments to the test procedure. Additionally, DOE has tentatively 
determined that the proposed amendments to appendix M1, if made final, 
would not increase the cost of testing. If finalized, representations 
of energy use or energy efficiency would be required to be based on 
testing in accordance with the amended test procedure in appendix M1 
beginning 180 days after the date of publication of the test procedure 
final rule in the Federal Register.
    DOE has tentatively determined, however, that the newly proposed 
test procedure at appendix M2 would, if adopted, alter the measured 
efficiency of CAC/HPs, in part because the amended test procedure would 
adopt different energy efficiency metrics than in the current test 
procedure. Additionally, DOE has tentatively determined that the 
proposed amendments to appendix M2, if made final, would not increase 
the cost of testing. Tentative cost estimates are discussed in section 
III.L of this document. As discussed, use of appendix M2 would not be 
required until the compliance date of amended energy conservation 
standards denominated in terms of SCORE and SHORE, should DOE adopt 
such standards.
    The proposed amendments to representation requirements in 10 CFR 
429.43 would not be required until 180 days after publication in the 
Federal Register of a test procedure final rule.
    Discussion of DOE's proposed actions are addressed in further 
detail in section III of this NOPR.

III. Discussion

    In the following sections, DOE proposes certain amendments to its 
test procedures for CAC/HPs. For each proposed amendment, DOE provides 
relevant background information, explains why the proposed amendment 
merits consideration, discusses relevant public comments, and proposes 
a potential approach.

A. Scope of Applicability

    This rulemaking applies to CAC/HPs. DOE defines the term Central 
air conditioner or central air conditioner heat pump to mean a product, 
other than a packaged terminal air conditioner or packaged terminal 
heat pump, single-phase single-package vertical air conditioner with 
cooling capacity less than 65,000 British thermal units (``Btu'') per 
hour (``Btu/h''), single-phase single-package vertical heat pump with 
cooling capacity less than 65,000 Btu/h, computer room air conditioner, 
or unitary dedicated outdoor air system as these equipment categories 
are defined at 10 CFR 431.92, which is powered by single phase electric 
current, air cooled, rated below 65,000 Btu/h, not contained within the 
same cabinet as a furnace, the rated capacity of which is above 225,000 
Btu/h, and is a heat pump or a cooling unit only. A central air 
conditioner or central air conditioning heat pump may consist of: A 
single-package unit; an outdoor unit and one or more indoor units; an 
indoor unit only; or an outdoor unit with no match. In the case of an 
indoor unit only or an outdoor unit with no match, the unit must be 
tested and rated as a system (combination of both an indoor and an 
outdoor unit). 10 CFR 430.2.
    Appendix M1 applies to the following CACs/HPs:
    (a) Split-system air conditioners, including single-split, multi-
head mini-split, multi-split (including VRF), and multi-circuit 
systems;
    (b) Split-system heat pumps, including single-split, multi-head 
mini-split, multi-split (including VRF), and multi-circuit systems;
    (c) Single-package air conditioners;
    (d) Single-package heat pumps;
    (e) Small-duct, high-velocity systems (including VRF);
    (f) Space-constrained products--air conditioners; and
    (g) Space-constrained products--heat pumps.
    See section 1.1 of appendix M1.
    DOE is not proposing to change the scope of CACs/HPs covered by the 
test procedure in appendix M1 or the proposed appendix M2.

B. Definitions

    CAC/HPs are defined in 10 CFR 430.2, as described in the previous 
section. This definition was last amended in the October 2022 Final 
Rule. DOE revised the central air conditioner or central air 
conditioning heat pump definition so that it explicitly excluded 
certain equipment categories that met the CAC/HP definition based on 
their characteristics but are exclusively distributed in commerce for 
commercial and industrial applications. 87 FR 64550, 64573. DOE noted 
in the October 2022 Final Rule that there are certain types of 
equipment that meet the CAC/HP definition but are exclusively 
distributed in commerce for commercial and industrial applications, and 
that EPCA did not intend to regulate as consumer products. Id.
    As laid out in section 1.1 of appendix M1, the test procedure 
applies to CAC/

[[Page 24211]]

HPs, including the following categories, which are defined either in 10 
CFR 430.2 or in section 1.2 of appendix M1:
    (a) Split-system air conditioners, including single-split, multi-
head mini-split, multi-split (including variable refrigerant flow 
(``VRF'')), and multi-circuit systems;
    (b) Split-system heat pumps, including single-split, multi-head 
mini-split, multi- split (including VRF), and multi-circuit systems;
    (c) Single-package air conditioners;
    (d) Single-package heat pumps;
    (e) Small-duct, high-velocity systems (including VRF);
    (f) Space-constrained products--air conditioners; and
    (g) Space-constrained products--heat pumps.
    In the January 2023 RFI, DOE sought comment on whether the 
definition of CAC/HP needs revision, and whether the scope of the 
appendices M and M1 needs to be limited, expanded, clarified, or 
revised in any way.\8\ 88 FR 4091, 4093.
---------------------------------------------------------------------------

    \8\ On January 1, 2023, use of appendix M1 became required for 
any representations--including compliance certifications--made with 
respect to the energy use, power, or efficiency of CAC/HPs. Prior to 
January 1, 2023, such representations were required to be based on 
the test procedure at appendix M to subpart B of 10 CFR part 430.
---------------------------------------------------------------------------

    In its response, Rheem requested a revision to the definition and 
scope of CAC/HPs covered by appendix M1 to add a new product class of 
``space-constrained vertical package'' product. (Rheem, No. 12 at pp. 
1-2) Rheem proposed that this new product class would meet all 
definitions of the current ``space-constrained'' product class but also 
consist of the following three additions: (1) is factory-assembled as a 
single package that has major components that are arranged vertically; 
(2) is intended for interior mounting on adjacent, interior to, or 
through an outside wall; (3) and is non-weatherized. (Id.) Rheem 
suggested the product class delineation should be used to establish a 
reasonable minimum test external static pressure (``ESP'') of 0.15 
inches of water column (``in. wc.''), which Rheem claimed will result 
in more congruity between tested and actual unit operation for the 
consumer for these types of units. Id.
    Rheem asserted that DOE's current space-constrained product class 
is too general, and as a result puts unreasonable testing burden on 
``space-constrained vertical package'' units. (Id.) Specifically, Rheem 
commented that the minimum ESP of 0.3 in. wc. required by appendix M1 
for space-constrained products \9\ is not representative of 
installations of these units. Rheem explained that ``space-constrained 
vertical package'' products are typically entirely installed inside a 
closet with a short supply duct of 5-15 feet, without a return duct, 
and usually are found within small multifamily or lodging applications 
(such as assisted living and low-income housing). (Id.) Additionally, 
Rheem noted that one of its brands, Friedrich, has multiple products in 
which operation at an ESP greater than 0.3 in. wc. is prohibited per 
the installation and operation instructions. (Id.) Rheem commented that 
designing and testing the equipment to meet the minimum 0.3 in. wc. 
requirement of the current space-constrained category will lead to size 
and cost changes that will serve no benefit to the consumer and would 
make replacement units cost or size prohibitive. (Id.)
---------------------------------------------------------------------------

    \9\ See Table 4 of appendix M1 for the minimum ESP requirements 
for ducted blower-coil systems, including the 0.3 in. wc. 
requirement for space-constrained systems.
---------------------------------------------------------------------------

    DOE notes that Rheem's comment lacked sufficient information, such 
as product literature and test data, that would indicate that the 
current test procedure ESP requirement for ``space-constrained'' 
products is unsuitable for the products Rheem described in its comment, 
puts undue burden on manufacturers for testing, and is not 
representative of current installations of these units in the field. 
DOE is not aware of any space-constrained products that are not able to 
be tested according to the existing test procedure requirements. Given 
the limited information describing the products that are the subject of 
Rheem's comment, DOE is not proposing to amend the definition of space-
constrained vertical package units within the scope of CAC/HPs.
    Regarding the scope and definition of CAC/HPs, AHRI, Carrier, and 
Lennox all submitted comments relating to a definition for heat pumps 
optimized for performance in cold climates. (AHRI, No. 14 at p. 7; 
Carrier, No. 5 at p. 2; Lennox, No. 6 at p. 3) Comments regarding heat 
pumps optimized for low-temperature heating performance are discussed 
in section III.F.2 of this NOPR. AHRI also submitted a comment 
regarding systems that use a heat pump and a furnace in combination as 
a source for heating (i.e., ``dual-fuel'' heat pumps). (AHRI, No. 14 at 
p. 7) Comments regarding such systems are discussed in section III.F.6 
of this NOPR.
    Notably, both Carrier and Lennox commented that they find the 
current scope of CAC/HPs covered by appendix M1 to be appropriate. 
(Carrier, No. 5 at p. 2; Lennox, No. 6 at p. 3) Lennox also stated that 
it finds the general definition of central air conditioner or central 
air conditioning heat pump to be adequate. (Lennox, No. 6 at p. 3)
    Except as noted, DOE is not proposing any further amendments to the 
definition of central air conditioner or to the scope of CAC/HPs 
covered by appendix M1 or the newly proposed appendix M2.

C. Updates to Industry Standards

    DOE's current test procedures for CAC/HPs are codified at appendix 
M1 and incorporate by reference various industry standards. The 
regulatory text at appendix M1 has generally been closely aligned with 
the relevant industry standard for CAC/HPs, AHRI Standard 210/240--
however, several rulemakings have changed the regulatory portions of 
appendix M1 over time with amendments and additions, not all of which 
have been mirrored in the AHRI 210/240 standards.
    Appendix M1 currently references ANSI/AHRI 210/240-2008 with 
Addenda 1 and 2 (``AHRI 210/240-2008'' \10\): 2008 Standard for 
Performance Rating of Unitary Air Conditioning & Air-Source Heat Pump 
Equipment. However, the latest AHRI Standard 210/240 is AHRI 210/240-
2023, Standard for Performance Rating of Unitary Air Conditioning & Air 
Source Heat Pump Equipment, copyright 2020 (``AHRI 210/240-2023 
(2020)'' \11\).
---------------------------------------------------------------------------

    \10\ A copy of AHRI 210/240-2008 can be obtained from AHRI, 2111 
Wilson Boulevard, Suite 500, Arlington, VA 22201, USA, 703-524-8800, 
or by going to www.ahrinet.org.
    \11\ A copy of AHRI 210/240-2023 (2020) can be obtained from 
AHRI, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, USA, 
703-524-8800, or by going to www.ahrinet.org.
---------------------------------------------------------------------------

    Following publication of the January 2023 RFI, AHRI and other 
relevant stakeholders, including DOE, participated in the development 
of two updated industry standards relevant to CAC/HPs, the AHRI 210/
240-202X Draft and the AHRI 1600-202X Draft.\12\ DOE understands that 
these drafts were commissioned primarily to address the issues raised 
by DOE in the January 2023 RFI, and secondarily to harmonize the AHRI 
industry standards with the DOE test procedures, which were last 
amended in the October 2022 Final Rule.
---------------------------------------------------------------------------

    \12\ Both draft standards are available in Docket No. EERE-2022-
BT-TP-0028.
---------------------------------------------------------------------------

    DOE has reviewed both drafts and determined that they allow for a 
more representative measurement of the efficiencies of CAC/HPs than the 
current Federal test procedure, without being unduly burdensome. Rather 
than make

[[Page 24212]]

more amendments to the regulatory text of the current appendix M1 test 
procedure, DOE is proposing to adopt each industry standard 
respectively as the basis for an updated appendix M1 and a new appendix 
M2, similar to how AHRI 210/240-2008 was adopted as the basis of the 
current appendix M1 test procedure. Specifically, DOE is proposing to 
incorporate by reference AHRI 210/240-202X Draft, and the relevant 
standards it references: ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and 
ASHRAE 116-2010 as the basis for the updated appendix M1 test 
procedure. Similarly, DOE is proposing to incorporate by reference AHRI 
1600-202X Draft, and the relevant standards it references ANSI/ASHRAE 
16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010 as the basis for the 
new appendix M2 test procedure. Incorporating each industry standard 
would enable DOE to better harmonize with the industry standards and 
eliminate manufacturer burden in certifying with separate test 
procedures.
1. AHRI 210/240-202X Draft
    As previously discussed, AHRI and other relevant stakeholders, 
including DOE, worked to develop a revised AHRI 210/240 standard that 
would incorporate revisions to align with the October 2022 Final Rule, 
and additionally, seek to address the issues raised in the January 2023 
RFI with broad stakeholder consensus. DOE understands that this new 
update is currently in draft form (i.e., AHRI 210/240-202X Draft) and 
will supersede the current version of the standard, AHRI 210/240-2023 
(2020). While AHRI 210/240-202X Draft does not introduce changes that 
would alter the measured efficiency of CAC/HPs, it does introduce new 
test provisions as compared to AHRI 210/240-2023 (2020), and addresses 
several issues that DOE raised in the January 2023 RFI. Section III.F 
of this NOPR includes further discussion of the changes that are 
reflected in AHRI 210/240-202X Draft.
    In light of these updates to AHRI 210/240-202X Draft, DOE is 
proposing to amend its test procedure for CAC/HPs at appendix M1 by 
incorporating by reference AHRI 210/240-202X Draft. DOE intends to 
update its incorporation by reference to the final published version of 
AHRI 210/240-202X Draft in the final rule, unless the draft version is 
not finalized before the final rule or there are substantive changes 
between the draft and published versions, in which case DOE may adopt 
the substance of the AHRI 210/240-202X Draft or provide additional 
opportunity for comment on the substantive changes to the updated 
industry consensus standard. Specifically, DOE is proposing to utilize 
sections 3 (excluding 3.2.15, 3.2.19, 3.2.47, 3.2.52, 3.2.64, 3.2.79 
and 3.2.80), 5, 6 (excluding 6.1.8, 6.2, 6.3, 6.4 and 6.5), 11, and 12 
and appendices D, E, G, K, and L of the AHRI 210/240-202X Draft in the 
Federal test procedure for CAC/HPs at appendix M1.
    Additionally, DOE is proposing additions and deletions to the 
incorporations by reference for the CAC/HP Federal test procedure to 
align with the references made within the AHRI 210/240-202X Draft. 
Currently, appendix M1 incorporates by reference: AMCA 210-2007,\13\ 
AHRI 210/240-2008, AHRI 1230-2010,\14\ ASHRAE 23.1-2010,\15\ ANSI/
ASHRAE 37-2009, and ASHRAE 116-2010. 10 CFR 430.3.
---------------------------------------------------------------------------

    \13\ ANSI/AMCA 210-2007, ANSI/ASHRAE 51-2007, (``AMCA 210-
2007'') Laboratory Methods of Testing Fans for Certified Aerodynamic 
Performance Rating, ANSI approved Aug. 17, 2007. A copy of AMCA 210-
2007 can be purchased from the Air Movement and Control Association 
International Inc. (``AMCA'') website at www.amca.org/store/index.php.
    \14\ ANSI/AHRI 1230-2010 with Addendum 2, (``AHRI 1230-2010''): 
2010 Standard for Performance Rating of Variable Refrigerant Flow 
(``VRF'') Multi-Split Air-Conditioning and Heat Pump Equipment, ANSI 
approved Aug. 2, 2010. A copy of AHRI 1230-2010 can be obtained from 
AHRI, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, USA, 
703-524-8800, or by going to www.ahrinet.org.
    \15\ ANSI/ASHRAE 23.1-2010, (``ASHRAE 23.1-2010''): Methods of 
Testing for Rating the Performance of Positive Displacement 
Refrigerant Compressors and Condensing Units that Operate at 
Subcritical Temperatures of the Refrigerant, ANSI approved Jan. 28, 
2010. A copy of ASHRAE 23.1-2010 can be obtained from the ASHRAE 
website at www.ashrae.org/resources--publications.
---------------------------------------------------------------------------

    In the proposed test procedures at appendix M1, DOE is proposing to 
add an incorporation by reference to ANSI/ASHRAE 16-2016 and remove 
incorporations by reference to AMCA 210-2007, AHRI 210/240-2008, AHRI 
1230-2010 and ASHRAE 23.1-2010. Therefore, DOE is proposing to 
incorporate by reference the AHRI 210/240-202X Draft, ANSI/ASHRAE 16-
2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010, at appendix M1.
2. AHRI 1600-202X Draft
    In parallel to the AHRI 210/240-202X Draft, AHRI and other relevant 
stakeholders, including DOE, worked to develop a forward-looking AHRI 
test procedure that would act as the successor to the AHRI 210/240-202X 
Draft and be effective in the long-term (i.e., AHRI 1600-202X Draft). 
DOE is proposing to establish a new test procedure for CAC/HPs at 
appendix M2 by incorporating by reference AHRI 1600-202X Draft. DOE 
intends to update its incorporation by reference to the final published 
version of AHRI 1600-202X Draft in the final rule, unless the draft 
version is not finalized before the final rule or there are substantive 
changes between the draft and published versions, in which case DOE may 
adopt the substance of the AHRI 1600-202X Draft or provide additional 
opportunity for comment on the substantive changes to the updated 
industry consensus standard. Specifically, DOE is proposing to utilize 
sections 3 (excluding 3.1.15, 3.1.19, 3.1.47, 3.1.52, 3.1.65, 3.1.80, 
and 3.1.81), 5, 6 (excluding 6.1.8, 6.2, 6.3, 6.4 and 6.5), 11, and 12 
and appendices D, E, G, K, and L of the AHRI 1600-202X Draft in the 
Federal test procedure for CAC/HPs at appendix M2.
    DOE is also proposing to incorporate by reference ANSI/ASHRAE 16-
2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010, which are referenced 
within AHRI 1600-202X Draft. Therefore, in total, DOE is proposing to 
incorporate by reference the AHRI 1600-202X Draft, ANSI/ASHRAE 16-2016, 
ANSI/ASHRAE 37-2009, and ASHRAE 116-2010, at appendix M2.
3. ANSI/ASHRAE 37-2009
    ANSI/ASHRAE 37-2009, which provides a method of test for many 
categories of air conditioning and heating products and equipment, is 
referenced for testing CAC/HPs by both AHRI 210/240-202X Draft and the 
AHRI 1600-202X Draft. More specifically, section 5 and appendices C, D, 
E, I, and J of AHRI 210/240-202X and AHRI 1600-202X Draft refer to 
methods of test in ANSI/ASHRAE 37-2009. DOE currently incorporates by 
reference ANSI/ASHRAE 37-2009 in 10 CFR part 430, subpart B, and the 
current incorporation by reference applies to the current Federal test 
procedure for CAC/HPs specified at appendix M1. Given that AHRI 210/
240-202X Draft references ANSI/ASHRAE 37-2009 for several test 
instructions, DOE has tentatively concluded that it is appropriate to 
maintain the existing incorporation by reference of ANSI/ASHRAE 37-2009 
in appendix M1. Additionally, given that the AHRI 1600-202X Draft 
references ANSI/ASHRAE 37-2009 for several test instructions, DOE is 
proposing to additionally incorporate by reference ANSI/ASHRAE 37-2009 
for use with appendix M2.
4. ANSI/ASHRAE 16-2016
    ANSI/ASHRAE 16-2016, which provides a method of test for rating 
Room Air Conditioners, Packaged Terminal Air Conditioners, and Packaged 
Terminal Heat Pumps, is referenced for testing CAC/HPs by both

[[Page 24213]]

the AHRI 210/240-202X Draft and the AHRI 1600-202X Draft. More 
specifically, section 5.1.1 of AHRI 210/240-202X Draft and AHRI 1600-
202X Draft refer to testing of non-ducted CAC/HPs from provisions in 
ANSI/ASHRAE 16-2016, or by using a combination of provisions in ANSI/
ASHRAE 37-2009 and ANSI/ASHRAE 116-2016. Currently, ANSI/ASHRAE 16-2016 
is not incorporated by reference in appendix M1. DOE has tentatively 
concluded that testing conducted per ANSI/ASHRAE 16-2016 for non-ducted 
CAC/HPs, will not impact ratings in comparison to testing conducted per 
provisions in ANSI/ASHRAE 37-2009 and ANSI/ASHRAE 116-2010. Thus, given 
that the AHRI 210/240-202X Draft and AHRI 1600 202X Draft refer to 
ANSI/ASHRAE 16-2016 as an option for testing of non-ducted CAC/HPs, and 
that it does not impact ratings, DOE has tentatively concluded that it 
is appropriate to incorporate by reference ANSI/ASHRAE 16-2016 for 
appendices M1 and M2.
5. ANSI/ASHRAE 116-2010
    ANSI/ASHRAE 116-2010, which provides a method of test for unitary 
air conditioners and heat pumps with a cooling capacity of 65,000 Btu/h 
and less, is referenced for testing CAC/HPs by both AHRI 210/240-202X 
Draft and AHRI 1600-202X Draft. More specifically, sections 5, 6, 8, 
and 11 and appendices D and E of AHRI 210/240-202X Draft and AHRI 1600-
202X Draft refer to methods of test in ANSI/ASHRAE 116-2010. Given that 
AHRI 210/240-202X Draft references ANSI/ASHRAE 116-2010 for several 
test instructions, DOE has tentatively concluded that it is appropriate 
to maintain the existing incorporation by reference of ANSI/ASHRAE 116-
2010 in appendix M1. Additionally, given that the AHRI 1600-202X Draft 
references ANSI/ASHRAE 116-2010 for several test instructions, DOE is 
proposing to additionally incorporate by reference ANSI/ASHRAE 116-2010 
for use with appendix M2.

D. Proposed CAC/HP Test Procedure

    As discussed, EPCA requires that test procedures for each type of 
covered product, including CAC/HPs, 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 or period of use. (42 U.S.C. 
6293(b)(1)(A))
    In this NOPR, DOE is proposing to maintain the current efficiency 
metrics of SEER2 and HSPF2 in appendix M1 and is proposing to reference 
AHRI 210/240-202X Draft in appendix M1 for measuring the existing 
metrics. DOE has tentatively determined that the proposed amendments to 
appendix M1 would not affect the measured efficiency of CAC/HPs or 
require retesting solely because of DOE's adoption of the proposed 
amendments to the appendix M1 test procedure, if made final. 
Additionally, DOE is proposing to establish a new test procedure at 
appendix M2 that would adopt the AHRI 1600-202X Draft, including the 
newly proposed SCORE and SHORE metrics. Use of appendix M2 would not be 
required until the compliance date of any amended standards denominated 
in terms of the proposed new metrics for appendix M2, should such 
standards be adopted.
    If finalized versions of AHRI 210/240 and AHRI 1600 are not 
published before the test procedure final rule, or if there are 
substantive changes between the drafts and published versions of the 
standards that are not supported by stakeholder comments in response to 
this NOPR, DOE may adopt the substance of the AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft or provide additional opportunity for comment 
on the final version of that industry consensus standard.
    Specifically, at appendix M1, DOE is proposing to require the 
following sections of the AHRI 210/240-202X Draft: sections 3 \16\, 5, 
6 \17\, 11, and 12, and appendices D, E, G, K, and L. At appendix M2, 
DOE is proposing to require the following sections of the AHRI 1600-
202X Draft: sections 3 \18\, 5, 6 \19\, 11, and 12 and appendices D, E, 
G, K and L.
---------------------------------------------------------------------------

    \16\ DOE is not proposing to include the following provisions 
from section 3 of AHRI 210/240-202X Draft because the terms are 
either defined in appendix M1, or are not needed for the proposed 
DOE test procedure: 3.2.15 (Double-duct system), 3.2.19 (Gross 
Capacity), 3.2.47 (Oil Recovery Mode), 3.2.52 (Published Rating), 
3.2.64 (Standard Filter), 3.2.80 (Unitary Air-conditioner), and 
3.2.81 (Unitary Heat Pump).
    \17\ DOE is not proposing to include the following provisions 
from section 6 of AHRI 210/240-202X Draft because the provisions are 
either defined in 10 CFR 429.16, or are not needed for the proposed 
DOE test procedure: 6.1.8 (Tested Combinations or Tested Units), 6.2 
(Application Ratings), 6.3 (Publication of Ratings), 6.4 (Ratings), 
and 6.5 (Uncertainty and Variability).
    \18\ DOE is not proposing to include the following provisions 
from section 3 of AHRI 1600-202X Draft because the terms are either 
defined in appendix M1, or are not needed for the proposed DOE test 
procedure: 3.1.15 (Double-duct System), 3.1.19 (Gross Capacity), 
3.1.47 (Oil Recovery Mode), 3.1.52 (Published Rating), 3.1.65 
(Standard Filter), 3.1.80 (Unitary Air-conditioner), and 3.1.81 
(Unitary Heat Pump).
    \19\ DOE is not proposing to include the following provisions 
from section 6 of AHRI 1600-202X Draft because the provisions are 
either defined in 10 CFR 429.16, or are not needed for the proposed 
DOE test procedure: 6.1.8 (Tested Combinations or Tested Units), 6.2 
(Application Ratings), 6.3 (Publication of Ratings), 6.4 (Ratings), 
and 6.5 (Uncertainty and Variability).
---------------------------------------------------------------------------

    Further, at both appendix M1 and appendix M2, DOE is proposing to 
incorporate by reference the following: ANSI/ASHRAE 37-2009; ANSI/
ASHRAE 16-2016; and ANSI/ASHRAE 116-2010.
    Issue 1: DOE requests feedback on its proposal to revise appendix 
M1 to incorporate by reference AHRI 210/240-202X Draft for measuring 
the existing metrics, SEER2 and HSPF2.
    Issue 2: DOE requests feedback on its proposal to establish a new 
appendix M2, which would incorporate by reference AHRI 1600-202X Draft 
to determine the SCORE and SHORE metrics.

E. Efficiency Metrics

    As discussed, DOE proposes to update the current Federal test 
procedure for CAC/HPs at appendix M1 consistent with the most recent 
draft version of the relevant industry consensus test procedure, AHRI 
210/240-202X Draft. DOE is also proposing a new Federal test procedure 
at 10 CFR part 430, subpart B, appendix M2, consistent with the draft 
version of the industry consensus test procedure, AHRI 1600-202X Draft. 
Sections III.E.1 and III.E.2 indicate which metrics are applicable for 
appendices M1 and M2, respectively.
1. Metrics Applicable to Appendix M1
    In the updated appendix M1, DOE proposes to maintain the current 
energy efficiency metrics (i.e., energy efficiency ratio 2 (``EER2''), 
SEER2, and HSPF2), and to define a new optional metric: the peak load 
coefficient of performance (``COPpeak''), applicable to CHPs 
(see details in section III.F.2.d of this document). The proposed 
revisions to appendix M1 to align with the most recent draft of AHRI 
210/240-202X Draft maintain the existing energy efficiency metrics, and 
DOE has tentatively determined that testing under the proposed appendix 
M1 would be consistent with the existing test procedure and there would 
be no impact on measured efficiencies.
2. Metrics Applicable to Appendix M2
    As previously discussed in this NOPR, the proposed appendix M2 will 
introduce new integrated cooling and integrated heating efficiency 
metrics, namely SCORE and SHORE, respectively. Unlike SEER2 and HSPF2, 
which are seasonal energy efficiency descriptors, SCORE and SHORE are

[[Page 24214]]

integrated metrics that include off-mode power, PW,OFF. 
Hence, appendix M2 will not require separate representations for off-
mode power.
    DOE is proposing to retain EER2 in appendix M2, with EER2 evaluated 
in the same way as it was in appendix M1. DOE is also proposing the 
determination of an optional metric, COPpeak, as discussed 
in section III.E.1 of this document, in appendix M2.

F. Near-Term Changes in the CAC/HP Test Procedure

    The following sections discuss issues that affect the CAC/HP test 
procedure in the near-term--i.e., they will be effective 180 days after 
publication of the final rule. As previously explained, these near-term 
revisions are implemented at appendix M1 via incorporation by reference 
of the relevant industry consensus test procedure, AHRI 210/240-202X 
Draft. DOE has reviewed AHRI 210/240-202X Draft and has concluded that 
it satisfies the EPCA requirement that test procedures should not be 
unduly burdensome to conduct and should be representative of an average 
use cycle. (42 U.S.C. 6293(b)(1)(A)) These near-term amendments in 
appendix M1 would not alter the measured efficiency of CAC/HPs in terms 
of the current cooling and heating test metrics, SEER2 and HSPF2, 
respectively.
    DOE clarifies that while all issues discussed subsequently are 
considered near-term, they are also part of the long-term CAC/HP test 
procedure--i.e., these revisions are also included in AHRI 1600-202X 
Draft, which DOE is proposing to incorporate by reference at appendix 
M2. As such, when discussing these near-term changes, DOE makes 
references to both AHRI 210/240-202X Draft and AHRI 1600-202X Draft.
1. Representativeness of Fixed Speed Testing for Variable Speed (VS) 
Systems
(a) Background
    Appendix M1 uses a steady-state test concept where test room 
conditions are kept within narrow operating tolerances for each test 
point, and the CAC/HP system is manually controlled to operate at the 
specified compressor speed and airflow rate for each test point. In the 
October 2022 Final Rule, several stakeholders encouraged DOE to review 
ways to improve the representativeness of the test procedures for CAC/
HPs (especially variable speed), particularly to examine test 
procedures where the unit operates under its own native controls in 
responding to conditioning loads (i.e., load-based testing).\20\ DOE 
stated in the October 2022 Final Rule that the rulemaking had been 
initiated only to address a limited number of known issues in the 
current appendix M1 method, including those raised through the test 
procedure waiver process. 87 FR 64554, 64554. However, DOE also 
responded that in order to satisfy the 7-year lookback requirement (see 
42 U.S.C. 6293(b)(1)(A)), a future rulemaking may address more 
comprehensively the issues raised by the commenters. (Id.)
---------------------------------------------------------------------------

    \20\ A load-based test method differs from the steady-state test 
method currently used in DOE test procedures for air conditioning 
and heat pump equipment. In a steady-state test method, the indoor 
room is maintained at a constant temperature throughout the test. In 
this type of test, any variable speed or variable-position 
components of air conditioners and heat pumps are set in a fixed 
position, which is typically specified by the manufacturer. In 
contrast, a load-based test has the conditioning load applied to the 
indoor room using a load profile that approximates how the load 
varies for units installed in the field. In this type of test, an 
air conditioning system or heat pump is allowed to automatically 
determine and vary its control settings in response to the imposed 
conditioning loads rather than relying on manufacturer-specified 
settings.
---------------------------------------------------------------------------

    As discussed in section I.B of this document, on January 24, 2023, 
DOE published the January 2023 RFI in order to collect data and 
information regarding the need to amend the test procedures for CAC/
HPs, to address issues raised by commenters in the October 2022 Final 
Rule, and in satisfaction of the 7-year review requirement specified in 
EPCA. (42 U.S.C. 6293(b)(1)(A)). 87 FR 64554, 64554. In the January 
2023 RFI, DOE requested comments, information, and data pertaining to 
the consideration of load-based testing methodologies under development 
by various organizations and whether certain aspects of these 
methodologies might be adopted into the DOE test procedure. 88 FR 4091, 
4098-4101. Among the load-based testing methodologies summarized by DOE 
in the January 2023 RFI was the first edition of Canadian Standard 
Association (``CSA'') EXP07:19, ``Load-based and climate-specific 
testing and rating procedures for heat pumps and air conditioners'' 
(``EXP07''). 88 FR 4091, 4095. DOE notes that EXP07 was superseded by 
CSA SPE-07:23 \21\ (``SPE07'') in January 2023, an updated version of 
EXP07 with changes made based on comments received during a technical 
review period.
---------------------------------------------------------------------------

    \21\ SPE07 is available for download at: wwwcsagroup.org/store/product/CSA%20SPE-07:23/.
---------------------------------------------------------------------------

(b) Comments Received
    In response to the January 2023 RFI, DOE received a variety of 
comments related to various aspects of load-based testing. The comments 
are summarized in the following sub-sections, segregated by topic as 
appropriate.
(1) Repeatability and Reproducibility
    In the January 2023 RFI, DOE presented several initiatives and 
programs that were investigating, researching, and/or developing load-
based test methods. 88 FR 4091, 4095-4098. DOE requested data and 
information to quantify which of these load-based methods--and any 
other that DOE is not aware of--had higher repeatability and 
reproducibility compared to the others, and also compared to fixed-
speed tests. 88 FR 4091, 4099.
    In response, Samsung, Carrier, Daikin, Rheem, AHRI, and Lennox all 
commented that available test data have shown that the repeatability 
and reproducibility of load-based methods is not on par with current 
fixed-speed testing used for regulatory purposes. (Samsung, No. 11 at 
p. 1; Carrier, No. 5 at pp. 2-3; Daikin, No. 16 at pp. 2-3; Rheem, No. 
12 at pp. 2-3; AHRI, No. 14 at pp. 8-9; Lennox, No. 6 at p. 3) Samsung 
asserted that adopting something unproven, like the load-based test 
methods, may create a chaotic situation in the marketplace, and will 
create additional test burden for manufacturers since load-based 
testing methods do not address alternative efficiency determination 
methods (``AEDMs''). (Samsung, No. 11 at p. 1)
    Carrier referred to the Technology Collaboration Program of Energy 
Efficient End-use Equipment, International Energy Efficiency (``4E 
IEA'') \22\ and AHRI 8026 \23\ initiatives, which showed that load-
based testing of the same units across different facilities showed high 
variability, and commented that more work and research needs to be done 
in order to reduce this variability before adopting load-based testing 
for determining energy efficiency of CAC/HP systems. (Carrier, No. 5 at 
pp. 2-3) Daikin also commented that until all issues pertaining to 
load-based testing are fully vetted, there would be significant 
problems with repeatability and reproducibility. (Daikin, No. 16 at pp. 
2-3) Daikin mentioned several items that contribute to variability in 
load-

[[Page 24215]]

based testing, such as the controller (room thermostat), controller 
setup, control modifications in the test chamber, and the application 
of the load. (Id. at pp. 2-3) Daikin also requested that stakeholders 
thoroughly evaluate the secondary capacity check process during load-
based testing, and compare that with the accuracy, repeatability, and 
reproducibility of conventional fixed-speed testing. (Daikin, No. 16 at 
p. 12)
---------------------------------------------------------------------------

    \22\ ``AC/HP Test Methods Investigative Testing: Phase 2 
Preliminary Findings'' 4E IEA presentation (May 7, 2021). See 
www.iea-4e.org/wp-content/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf.
    \23\ Dhillon, P., Horton, W.T., & Braun, J.E. (2022). AHRI 
8026--Repeatability and Reproducibility Assessment of CSA EXP07:19 
and AHRI 210-240:2023. Air Conditioning, Heating, and Refrigeration 
Institute.
---------------------------------------------------------------------------

    Rheem and AHRI both referred to the results of AHRI 8026. (Rheem, 
No. 12 at pp. 2-3; AHRI, No. 14 at pp. 8-9) Rheem commented that per 
AHRI 8026, the transient conditions during load-based testing cause 
poorer repeatability and reproducibility in comparison to fixed-speed 
testing currently in appendix M1. (Rheem, No. 12 at pp. 2-3) Rheem 
further stated that even with appendix M1 testing, reproducibility of 
transient components like cyclic degradation and defrost can be 
challenging. (Id.) AHRI commented that AHRI 8026 results revealed 
concerns when it comes to repeatability and reproducibility of 
performance metrics of load-based testing. (AHRI, No. 14 at pp. 8-9) 
Further, AHRI noted that there are no analyses of control system 
parameter variability available for load-based testing, and that such 
analyses would require significant investments in lab facilities and 
technical training and none of the load-based testing methods address 
the use of AEDMs. (Id.) Similarly, Lennox mentioned several items that 
affect the repeatability and reproducibility of load-based testing, 
including the varying degrees of test burden in the different methods, 
changes required to lab facilities to accommodate load-based testing, 
interaction between the unit under test and the lab facility, and how 
the lab facility affects the load-based tests. (Lennox, No. 6 at p. 3) 
Lennox expressed concern over the fact that labs may need to 
significantly invest in their facilities and resources if their present 
setups were found to positively or negatively influence load-based test 
results. (Id.)
    NEEA commented that a pre-defined load test \24\ may have greater 
repeatability and reproducibility in comparison to an adaptive load 
test, because multiple variables need to be controlled for an adaptive 
load, and there are several interactive effects between unit 
performance and test lab conditions. (NEEA, No. 13 at p. 6) NEEA 
referred to the 4E IEA program,\25\ stating that preliminary results 
from phase 4 of 4 are expected to be available by mid-summer 2023, with 
full study results to be released at the end of 2023 or early in 2024. 
(Id.)
---------------------------------------------------------------------------

    \24\ In its comment, NEEA defined a pre-defined load test as 
those where the unit under test (UUT) is subjected to pre-defined 
sensible or latent loads, and stated that the 4E program and the DOE 
CCHP Tech Challenge were examples of such a load based test method. 
They defined adaptive load test methods as those where a constant or 
variable sensible and latent is applied to the UUT, but the 
magnitude of the load can be altered, based on unit behavior, and 
stated that the SPE07 was an example of such a method.
    \25\ ``AC/HP Test Methods Investigative Testing: Phase 2 
Preliminary Findings'' 4E IEA presentation (May 7, 2021). See: 
www.iea-4e.org/wpcontent/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf.
---------------------------------------------------------------------------

(2) Field Performance
    In the January 2023 RFI, DOE requested data showing that load-based 
testing was more representative of field performance, in comparison to 
conventional fixed-speed and fixed-setting test procedures. 88 FR 4091, 
4099. DOE also requested data that would indicate whether CAC/HP units 
that performed poorly in the lab, when tested using load-based methods, 
also performed poorly in the field. Id.
    Carrier commented that it was not aware of publicly available data 
showing that load-based test methods are more or less representative 
than fixed-speed and fixed-setting test procedures. (Carrier, No. 5 at 
p. 3) Carrier further commented that even though there is value in 
verifying the operation of variable speed systems, it was unclear if a 
load-based test method would provide more representative tests in 
comparison to fixed-speed testing with a controls verification 
procedure (``CVP'') to confirm unit operation at the speeds specified 
in the fixed-speed tests. (Id.) Similarly, Daikin stated that even 
though several studies are being conducted, there is a general lack of 
information and data to substantiate whether load-based testing or 
fixed-speed testing is more representative of real-world scenarios. 
(Daikin, No. 16 at p. 3) Daikin expressed concern over the fact that 
load-based test methods, such as SPE07, do not account for real-world 
scenarios when a CAC/HP is installed with a controller (or room 
thermostat) of a different brand than the manufacturer of the CAC/HP. 
(Id.) Daikin commented that if controller operation is central to load-
based testing, then smart thermostat manufacturers would also need to 
provide ratings when their product is matched with another 
manufacturer's CAC/HP, similar to the process followed by independent 
coil manufacturers (``ICMs'') for representing the ratings of their 
indoor coils with different combinations of other manufacturers' 
outdoor coils. (Id.) Daikin also commented that load-based test methods 
currently do not address AEDM calculation methods for non-tested 
combinations (``NTCs''), nor do they have a method for ICMs to rate 
their indoor coil products with an outdoor unit that has been tested 
using load-based methods. (Id.)
    Rheem commented that while it believed more studies are needed for 
evaluating the representativeness of load-based methods, field 
performance is very dependent on installation practices. (Rheem, No. 12 
at p. 3) The CA IOUs commented that the current appendix M1 test 
procedure uses fixed compressor speeds and air volume rates with fixed 
indoor and outdoor temperature conditions, and is thus not 
representative of field use, indicating that the energy efficiencies 
may be misinterpreted. (CA IOUs, No. 10 at pp. 1-2)
(3) Test Burden
    A critical component of load-based testing is the relevant 
burden(s) associated with the testing--i.e., total testing time, time 
needed for control system learning, number of official test points, 
time required to transition between test points, upgrades to laboratory 
equipment, and cost and time associated with training technicians to be 
able to conduct load-based testing. In the January 2023 RFI, DOE 
requested comment from stakeholders on information pertaining to the 
aforementioned test burdens. 88 FR 4091, 4099.
    In response, Carrier, Daikin, and Rheem commented that the test 
burden of load-based testing is generally more than that of fixed-speed 
testing. (Carrier, No. 5 at pp. 3-4; Daikin, No. 16 at pp. 3-4; Rheem, 
No. 12 at pp. 3-4) Regarding costs, Carrier commented that lab 
investments will be needed to emulate Virtual Building Load 
(``VBL''),\26\ and Rheem commented that even though predicting the cost 
impact of emerging load-based methods is difficult, there will 
definitely be costs associated with changes to test chambers and 
equipment that manufacturers will have to bear. (Carrier, No. 5 at pp. 
3-4; Rheem, No.

[[Page 24216]]

12 at pp. 3-4) Carrier and Daikin both commented that load-based 
testing methods would require more time to conduct due to the higher 
number of tests involved. (Carrier, No.5 at pp. 3-4; Daikin, No.16 at 
pp. 3-4)
---------------------------------------------------------------------------

    \26\ Virtual Building Load is a load-based or native controls 
test procedure during which the software that controls the indoor 
test room conditions (i.e., operates the indoor room reconditioning 
system) is programmed to mimic the response of building heating or 
cooling in real time by monitoring the capacity of the unit under 
test and adjusting the indoor room conditions according to the 
virtual building model. The virtual building model defines the time-
dependent rate of change of the indoor room temperature and humidity 
conditions as a function of the target building load and the 
measured capacity of the tested system.
---------------------------------------------------------------------------

    Daikin also stated that during new product development, 
manufacturers only have to do a subset of appendix M1 tests, often 
iteratively, because results of those subsets are enough to inform the 
manufacturer of the design changes needed. (Daikin, No. 16 at pp. 3-4) 
Daikin commented that due to lack of experience with load-based methods 
such as SPE07, it would not be possible to do quick assessments like 
these. (Id. at pp. 3-4) Finally, Daikin stated that changes to 
refrigerant regulations that will occur in 2023 will require a full 
redesign of the products, and manufacturers may not be able to 
accomplish that in a timely manner using load-based methods. (Id.)
    Rheem referred to the 4E IEA project report, in which it was 
estimated that the additional test burden due to the Target 
Compensation Load method will have a 60-percent to 250-percent increase 
in test burden. (Rheem, No. 12 at pp. 3-4) Rheem commented that load-
based test methods would require changes to control schemes, additional 
test setups, and additional equipment, due to rapidly changing loads 
inside the chamber. (Id.) Rheem referred to several research studies 
27 28 that showed load-based test methods are influenced by 
the thermal inertia of the psychrometric chambers in which the tests 
are conducted; thus, adaptation of the control system to this thermal 
inertia may be a time-consuming process. (Id.) AHRI stated that even 
though the value of load-based testing remains unknown, the burden has 
been quantified. (AHRI, No. 14 at p. 5)
---------------------------------------------------------------------------

    \27\ Cremaschi, L., & Perez Paez, P. (2017). Experimental 
feasibility study of a new load-based method of testing for light 
commercial unitary heating, ventilation, and air conditioning 
(ASHRAE RP-1608). Science and Technology for the Built Environment, 
23(7), 1178-1188. Available at www.tandfonline.com/doi/full/10.1080/23744731.2016.1274628.
    \28\ G[ouml]bel, S.A., Zottl, A., Noack, R., Mock, D., Wachau, 
A., Vering, C., & M[uuml]ller, D. (2022, August). How to calibrate 
heat pump test stands for load-based testing--Towards technology-
neutral prescriptions [Paper presentation]. 14th International 
Conference on Applied Energy, ICAE22, August 8-11, 2022, Bochum, 
Germany. Available at www.ebc.eonerc.rwth-aachen.de/go/id/dncb/file/
855717?lidx=1.
---------------------------------------------------------------------------

    In summary, all comments received indicated that the test burden 
for load-based testing will be higher than that of conventional fixed-
speed testing laid out in appendix M1.
(4) Thermostat Selection and Built-In Control Firmware
    Thermostats (i.e., ``control systems'') can vary significantly in 
their control algorithms and communication with the unit under test. 
Thus, thermostat selection can play a key role in the results of load-
based tests. In the January 2023 RFI, DOE requested comment on several 
impacts of thermostats with respect to load-based testing, including 
the observed range of performance of the same unit tested with 
different thermostats, and consideration of whether a thermostat needs 
to be certified as part of the tested combination. 88 FR 4091, 4099. 
DOE also requested comment on what percentage of thermostats may be 
updated remotely versus in the field, and how unit behavior in the 
field depends on thermostats shipped with the unit versus those 
purchased from third-party suppliers. (Id.)
    In response to this issue, DOE received comments from several 
stakeholders. Carrier and Rheem commented that thermostats have a big 
impact on load-based test results. (Carrier, No. 5 at p. 4; Rheem, No. 
12 at p. 4) Carrier commented that since the majority of HVAC systems 
in the market are not installed with a manufacturer`s thermostat, it 
would not be feasible for manufacturers to test with the different 
thermostats available. (Carrier, No. 5 at p. 4) Carrier further stated 
that only variable speed systems shipped with the manufacturer`s 
thermostat should have certification requirements. (Id.) The Joint 
Advocates and NYSERDA encouraged DOE to require certification of 
thermostats as part of the tested combination. (Joint Advocates, No. 8 
at p. 2; NYSERDA, No. 9 at pp. 6-7) Specifically, the Joint Advocates 
encouraged DOE to investigate how the performance of single-stage, two-
stage, and variable speed equipment is impacted by integrations of 
different thermostats, and to develop testing requirements for ensuring 
that the tested thermostat is representative of the one selected in the 
field. (Joint Advocates, No. 8 at pp. 2-3)
    NYSERDA commented that thermostat selection will be integral to a 
CVP, which verifies that the manufacturer`s supplemental testing 
instructions for setting critical parameters during fixed-speed testing 
are within the range of critical parameters that the system would 
utilize when operating under its native controls. (NYSERDA, No. 9 at 
pp. 6-7) NYSERDA further commented that communicating systems may only 
be compatible with certain thermostats; hence, DOE should have a 
regulatory requirement that discourages pairing such systems with 
third-party thermostats. (Id.) However, NYSERDA recognized that in some 
situations, such as for blower coil indoor units, the system has 
communication technology built in that allows the use of any 
thermostat, which may not require certification with external 
thermostats. (Id. at p. 7) NYSERDA concluded that the actual firmware 
governing unit behavior is built into the unit, and not into the 
thermostat, meaning that updated testing would be required only in 
instances when the updated firmware results in an updated model number. 
(Id.) AHRI stated that certification requirements will be complicated 
with thermostats, especially when utilizing those that are not 
specified by the manufacturer. (AHRI, No. 14 at pp. 9-10) AHRI also 
stated that different thermostats will give different load-based test 
results, and referred to an article stating that smart thermostats were 
only being used by 16 percent of households. (Id.)
    Daikin commented that due to the limited time allowed for 
submitting comments in response to the January 2023 RFI, it did not 
have thermostat-associated data to share with DOE other than that from 
its own ``Daikin One'' thermostat. (Daikin, No. 16 at pp. 4-5) Daikin 
stated that several issues pertain to thermostat selections, making 
load-based testing unrepresentative of real-world situations; for 
instance, Daikin questioned whether, in the case of systems installed 
with smart thermostats like Nest or EcoBee, the unit manufacturer will 
be responsible for rating the system if the thermostat receives a 
remote firmware upgrade. (Id.)
    Several commenters referred to Annex I of SPE07, which outlines a 
Thermostat Environment Emulator (``TEE'') developed by Purdue 
University that is a thermostat enclosure aimed at providing controlled 
airflow and temperature distribution to the air sensed by the 
thermostat. (Daikin, No. 16 at pp. 4-5; Joint Advocates, No. 8 at p. 3; 
NYSERDA, No. 9 at p. 7) Specifically, Daikin commented that the TEE 
demonstrated that thermostat location is an integral part of unit 
performance, but such an enclosure is not representative of real-world 
installations. (Daikin, No. 16 at pp. 4-5) In contrast, the Joint 
Advocates encouraged DOE to adopt something similar to the TEE in its 
test procedure so that reproducibility issues occurring between the 
various indoor rooms of psychrometric chambers (that conduct

[[Page 24217]]

load-based testing) may be mitigated. (Joint Advocates, No. 8 at p. 3)
    Rheem pointed out that temperature sensors inside thermostats may 
not be as responsive or accurate as laboratory-grade temperature 
sensors, and because of this, temperature offsets are often necessary 
for tests done under native controls. (Rheem, No. 12 at p. 4) Rheem 
further commented that since these offsets may be influenced by the air 
flow rate over the thermostat, thermostat location, and orientation, 
there may be a requirement to dynamically modify this offset as the 
load-based test proceeds. (Id.) Rheem stated that remote update of 
unit/controller firmware is a relatively new feature, and therefore not 
as widely available as firmware updates done in the field by service 
technicians. (Id.)
(5) Utilizing Distinct Test Methods for Different Purposes
    In the January 2023 RFI, DOE requested comment on whether there are 
any load-based methods that are being used for regulatory or voluntary 
incentive-based programs. 88 FR 4091, 4100. Rheem, AHRI, and NYSERDA 
all commented that they are unaware of any load-based methods being 
used for the aforementioned purposes. (Rheem, No. 12 at p. 4; AHRI, No. 
14 at p. 10; NYSERDA, No. 9 at p. 9) Daikin commented that in 2024, 
U.S. Environmental Protection Agency (``EPA'') ENERGY STAR[supreg] 
Version 6.1 specifications (``ENERGY STAR Spec V6.1'') \29\ will be 
required for the Canada Greener Homes Program, even though currently it 
is an optional load-based method applicable only to cold climate heat 
pumps (``CCHPs''). (Daikin, No. 16 at p. 5) Daikin pointed out that due 
to the resources and efforts required to develop new products with low 
global warming potential (``GWP'') refrigerants like R32, Daikin doubts 
it will engage in any non-mandatory load-based testing. (Id.) NYSERDA 
referred to three initiatives associated with load-based testing, 
namely (1) the Canadian market transformation roadmap presented at the 
2018 Energy and Mines Ministers' Conference,\30\ (2) British Columbia`s 
2022 Heat Pump Technology Attraction Strategy,\31\ and (3) a plan for 
differentiating advanced heat pumps using load-based testing criteria 
in the Northeast Energy Efficiency Partnerships (``NEEP'') qualified 
product list.\32\ (NYSERDA, No. 9 at pp. 8-9) NYSERDA encouraged 
incentive-based approaches for advanced heat pumps that include: (1) a 
CVP to identify unit operation under native controls, (2) using 
regional HSPF2 to differentiate advanced heat pumps, and (3) 
prescribing capacity maintenance and coefficient of performance 
(``COP'') levels at 5 [deg]F, similar to those in the ENERGY STAR Spec 
V6.1 requirements. (Id. at p. 9)
---------------------------------------------------------------------------

    \29\ Version 6.1 of the ENERGY STAR specification for CAC/HPs, 
revised in January 2022, can be found at www.energystar.gov/products/spec/central_air_conditioner_and_air_source_heat_pump_specification_version_6_0_pd.
    \30\ NYSERDA referred to p. 32 of the 2018 report titled 
``Paving the Road to 2030 and Beyond: Market transformation road map 
for energy efficient equipment in the building sector.'' Available 
at www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/electricity-alternative-energy/energy-efficiency/18-00072-nrcan-road-map-eng.pdf.
    \31\ NYSERDA referred to pages 20, 25, and 26 of the Vancouver 
Energy Commission's BC Heat Pump Technology Attraction Strategy, 
available at vancouvereconomic.com/wp-content/uploads/2022/11/11-2022-BC-Heat-Pump-Strategy-Report-Web-1.1.pdf.
    \32\ NYSERDA referred to page 14 of the ``Advanced Heat Pump 
White paper,'' available at www.mwalliance.org/sites/default/files/media-document/Advanced%20HP%20Whitepaper%20v1.13.pdf.
---------------------------------------------------------------------------

(6) Comparison of Test Conditions of Appendix M1 and SPE07
    In the January 2023 RFI, DOE provided a detailed explanation of the 
first edition of EXP07. 88 FR 4091, 4095. As previously mentioned, 
EXP07 was superseded by SPE07, an updated version of EXP07 with changes 
made based on comments received during a technical review period in 
January 2023. SPE07 is a load-based methodology where the unit under 
test is allowed to respond to a thermostat installed in the return air 
stream, while the indoor room conditioning equipment control is used to 
adjust that temperature (to represent heating or cooling conditioning 
load), mimicking the response of a typical building. The test sequences 
through a set of representative outdoor room conditions. In the January 
2023 RFI, DOE pointed out that these test conditions differ from those 
laid out in appendix M1. 88 FR 4091, 4100. Due to these differences, 
DOE requested comment on how unit performance would compare when tested 
using the SPE07 test conditions (indoor as well as outdoor) and the 
appendix M1 test conditions. Id. DOE further requested feedback on the 
pros and cons of potentially revising the test conditions in appendix 
M1. Id.
    AHRI pointed out that the concept of SPE07 is interesting from a 
research perspective but not suitable for regulatory purposes. (AHRI, 
No. 14 at p. 5) AHRI noted that the seasonal COP metrics in SPE07 are 
climate zone dependent, and there is no metric that calculates unit 
performance at a national average level. (AHRI, No. 14 at pp. 5-6) AHRI 
pointed to 42 U.S.C. 6291(22), to state that the seasonal COP metrics 
cannot be adopted by DOE in appendix M1 as the efficiency descriptors. 
(Id. at p. 6) Further, AHRI commented that SPE07 is currently not 
applicable to coil-only systems, which means that if adopted, the 
process of certification and enforcement for split systems would need 
to be overhauled. (Id.) AHRI also pointed that SPE07 currently does not 
address AEDMs, which implies that a regulatory regime under SPE07 would 
create significant test burden due to the large number of rated 
combinations of split-system units. (Id.) AHRI referred to the testing 
reporting requirements in appendix M1 for variable speed mini and 
multi-splits, stating that SPE07 does not properly define requirements 
for established ratings for these products. (Id. at p.7) Finally, AHRI 
cited a section of 42 U.S.C 6293(b)(3) to point out that test 
procedures should not be unduly burdensome to conduct.\33\ (Id.) AHRI 
commented that its commentary is limited to SPE07, stating that it is 
the most developed and established load-based methodology, but AHRI 
still does not see a viable pathway for SPE07 moving forward. (Id.)
---------------------------------------------------------------------------

    \33\ From this comment, DOE considers that AHRI wanted to make 
the point that SPE07, as it currently stands, is unduly burdensome.
---------------------------------------------------------------------------

    Daikin and Rheem both commented that since appendix M1 and SPE07 
have different performance metrics, their ratings cannot be compared. 
(Daikin, No. 16 at p. 5; Rheem, No. 12 at pp. 4-5) Daikin commented 
that it lacks data that can be shared comparing appendix M1 and SPE07 
testing. (Daikin, No. 16 at p. 5) Daikin pointed out that the different 
indoor dry bulb and wet bulb temperature setpoints in appendix M1 and 
SPE07 would lead to different efficiencies, and the higher number of 
test points in SPE07 adds to test burden. (Daikin, No. 16 at p. 5) 
Daikin referred to how the tolerance of 10 percent was chosen when 
commercial HVAC products moved to a seasonal metric (integrated energy 
efficiency ratio (``IEER'')), from a peak load metric (i.e., EER), 
rather than 5 percent, indicating that the tolerance for certified 
ratings would have to be increased if DOE adopted a load-based testing 
method for regulatory purposes. (Id. at p. 6)
    Rheem referred to a research paper \34\ to back its claim that 
relative rankings

[[Page 24218]]

of SPE07 and appendix M1 are impossible. (Rheem, No. 12 at pp. 4-5) 
Rheem further pointed out that since the indoor dry bulb and wet bulb 
temperature in appendix M1 are the same for all tests, the time for 
testing is optimized. (Id.) Similarly, Carrier commented that research 
currently in progress would enable a comparison of the ranking of units 
when tested with appendix M1 and SPE07, but any conclusions cannot be 
reached currently. (Carrier, No. 5 at pp. 4-5) Samsung supported AHRI`s 
comment on SPE07 and stated that load-based testing is not currently at 
a stage where it may be adopted as the mandatory test procedure by DOE. 
(Samsung, No. 11 at p. 1)
---------------------------------------------------------------------------

    \34\ Dhillon, P., Horton, W. T., & Braun, J. E. (2022). 
Comparison of residential heat pump heating seasonal performance 
based on load-based and steady-state testing methodologies. ASHRAE 
Transactions, 128(1), 181-189. Available at www.techstreet.com/standards/lv-22-c025-comparison-of-residential-heat-pump-heating-seasonal-performance-based-on-load-based-and-steady-state-testing-methodologies?product_id=2505150.
---------------------------------------------------------------------------

    BC Hydro strongly encouraged DOE to adopt SPE07 as the next test 
procedure for CAC/HPs and referred to four NEEA papers \35\ that 
highlighted lessons learned from EXP07 testing that prompted the update 
to SPE07. (BC Hydro, No. 15 at pp. 1-2) Similarly, both the CA IOUs and 
the Joint Advocates referred to a NEEP representativeness project \36\ 
and encouraged DOE to update the CAC/HP test procedure on the basis of 
those results. (CA IOUs, No. 10 at p. 2; Joint Advocates, No. 8 at p. 
2) NYSERDA commented that more work needs to be done in order to 
consider the VBL approach (used as the basis of testing in SPE07), and 
specifically referred to additional efforts needed to ensure the 
repeatability and reproducibility of this method--namely, field data to 
validate lab data, lab-to-lab round robin testing, and an uncertainty 
analysis method that accounts for the unit under test`s embedded 
controls and thermostat. (NYSERDA, No. 9 at p. 6)
---------------------------------------------------------------------------

    \35\ Heat Pump and Air Conditioner Efficiency Ratings: Why 
Metrics Matter. Available at neea.org/resources/heat-pump-and-air-conditioner-efficiency-ratings-why-metrics-matter.
    EXP07:19 Load-Based and Climate-Specific Testing and Rating 
Procedures for Heat Pumps and Air Conditioners. Available at 
neea.org/resources/exp0719-load-based-and-climate-specific-testing-and-rating-procedures-for-heat-pumps-and-air-conditioners.
    CSA EXP07: Ongoing Progress, Lessons Learned, and Future Work in 
Load-based Testing of Residential Heat Pumps. Available at neea.org/resources/csa-exp07-ongoing-progress-lessons-learned-and-future-work-in-load-based-testing-of-residential-heat-pumps.
    EXP07 Value Engineering Memo and PowerPoint. Available at 
neea.org/resources/exp07-value-engineering-memo-and-powerpoint.
    \36\ The NEEP Heat Pump Rating Representativeness Project. 
Available at neep.org/sites/default/files/media-files/hp_representativeness_research_project-rfp_7.7.21.pdf.
---------------------------------------------------------------------------

    Regarding test conditions, NYSERDA commented that it did not have 
specific analysis about the overall outdoor conditions but did point 
out: (1) SPE07 focuses on more extreme outdoor conditions; (2) 
different rankings of appendix M1 metrics and load-based testing 
results are mainly due to the influence of the unit`s native controls 
on operation and any minor changes to the appendix M1 test conditions 
will not have a big impact on rankings; and (3) the addition of a hot-
dry SEER2 rating would better capture performance at extreme 
climates.\37\ (NYSERDA, No. 9 at p. 10) AHRI recommended that a fair 
comparison of appendix M1 and SPE07 would involve a study where the 
test conditions of each are swapped and the test results compared. 
(AHRI, No. 14 at p. 10) AHRI added that measurement uncertainties 
associated with both procedures should be accounted for in the 
comparison as well. (Id.)
---------------------------------------------------------------------------

    \37\ In one of its comments, NYSERDA referred to the contents in 
Table II-1, which outlines the applicability of the load-based 
methods to equipment types (ducted or non-ducted), and the capacity 
measurement procedure (calorimetric room or air enthalpy method). 
(NYSERDA, No. 9 at p. 9) NYSERDA commented that DOE did not point 
out that SPE07 applies to ducted equipment, and the ENERGY STAR CCHP 
CVP applies to non-ducted equipment. DOE would like to point out 
that it did, in fact, indicate in the table that SPE07 and the 
ENERGY STAR CCHP CVP are applicable to ducted and non-ducted 
equipment, respectively.
---------------------------------------------------------------------------

(7) Communicating and Non-Communicating Variable Speed Systems
    Controls used with CAC/HPs may transfer information between system 
components (i.e., communicating systems), or they may use more 
conventional low-voltage on-off signals to indicate ``calls'' for space 
conditioning and/or consumer selection of fan settings (i.e., non-
communicating). Communicating systems are defined as those that 
communicate the difference between space temperature and space setpoint 
temperature to the control that sets compressor speed and provides a 
signal to the indoor fan to set fan speed appropriate for compressor 
staging and air volume rate. 87 FR 16830, 16837. In the January 2023 
RFI, DOE requested test data that could potentially show how the 
performance of communicating and non-communicating variable speed CAC/
HPs compares when tested using load-based methods, and how do load-
based methods address modulation of compressor speed for systems 
equipped with non-communicating controls. 88 FR 4091, 4100.
    In response, Daikin, Rheem, AHRI, and NYSERDA commented that they 
are not aware of any test or field data comparing the performance of 
communicating and non-communicating systems when tested using load-
based methods. (Daikin, No. 16 at p. 6; Rheem, No. 12 at p. 5; AHRI, 
No. 14 at pp. 10-11; NYSERDA, No. 9 at p. 10)
    Daikin commented that load-based test methods would incentivize 
manufacturers to develop control schemes that optimize performance in 
the test lab rather than in the field. (Daikin, No. 16 at p. 6) Daikin 
further stated that the definition adopted by DOE in the October 2022 
Final Rule \38\ for Variable Speed Coil-Only systems was too 
restrictive and will limit technology and progress. (Id.)
---------------------------------------------------------------------------

    \38\ Section 1.2 of appendix M1 defines ``Communicating Variable 
Speed Coil-Only Central Air Conditioner or Heat Pump'' as follows: 
Variable speed Communicating Coil-Only Central Air Conditioner or 
Heat Pump means a variable speed compressor system having a coil-
only indoor unit that is installed with a control system that (a) 
communicates the difference in space temperature and space setpoint 
temperature (not a setpoint value inferred from on/off thermostat 
signals) to the control that sets compressor speed; (b) provides a 
signal to the indoor fan to set fan speed appropriate for compressor 
staging and air volume rate; and (c) has installation instructions 
indicating that the required control system meeting both (a) and (b) 
must be installed.
---------------------------------------------------------------------------

    Rheem commented that even for non-communicating systems, operating 
parameters of the refrigeration cycle are affected by the heat sink 
temperatures and heat source. Rheem listed suction pressure, liquid 
line pressure, return gas temperature, and liquid line temperature as 
the parameters, and cited a research paper \39\ that outlined a 
variable system controlled by refrigerant superheat. (Rheem, No. 12 at 
p. 5)
---------------------------------------------------------------------------

    \39\ Yang, D. S., Lee, G., Kim, M. S., Cho, Y. M., Hwang, Y. J., 
& Chung, B. Y. (2004). A study on the capacity control of a variable 
speed vapor compression system using superheat information at 
compressor discharge. In 10th International Refrigeration and Air 
Conditioning Conference at Purdue, July 12-15, 2004. Purdue 
University Libraries, West Lafayette, IN. Available at 
docs.lib.purdue.edu/iracc/689/.
---------------------------------------------------------------------------

    NYSERDA commented that a non-communicating thermostat would not 
typically allow the variable speed system to modulate, and the system 
will simply cycle on and off like a single-speed system. (NYSERDA, No. 
9 at p. 10) NYSERDA cited a research paper indicating that for low-load 
conditions, variable speed units suffer more from cycling losses in 
comparison to single-stage and two-stage systems. (Id.)
(8) Load-Based Testing for Single-Stage and Two-Stage Systems
    In the January 2023 RFI, DOE requested comment on whether there

[[Page 24219]]

are aspects of single- and two-stage system operation that are not 
adequately captured by appendix M1, and if load-based testing should be 
applicable to them. 88 FR 4091, 4101. DOE also requested comment on 
whether the current cyclic tests in appendix M1 adequately capture 
cyclic losses associated with cycling of compressors when unit capacity 
exceeds building load. (Id.)
    In response, the Joint Advocates commented that even though load-
based testing is best suited to accurately capture part-load operation 
of variable speed systems, it may be beneficial to apply it to single-
stage and two-stage systems. (Joint Advocates, No. 8 at p. 2) In 
contrast, Carrier commented that appendix M1 captures the performance 
of single- and two-stage systems adequately, and the application of 
load-based testing to these systems will not provide any value. 
(Carrier, No. 5 at p. 5) Daikin commented that if fixed-speed testing 
(currently in appendix M1) is used for single-stage and two-stage 
products and load-based testing is used for variable speed products, 
then it will not be possible to compare these products on an equivalant 
basis. (Daikin, No. 16 at p. 6) Similarly, Rheem pointed out that load-
based testing is mainly appropriate for variable speed products, and 
its suitability for single-stage and two-stage systems is questionable. 
(Rheem, No. 12 at p. 5) AHRI commented that any test procedure needs to 
compare different equipment classes on an equal basis. (AHRI, No. 14 at 
p. 11)
    Regarding cyclic losses, the Joint Advocates commented that 
appendix M1 fails to properly account for the cycling performance of 
units. (Joint Advocates, No. 8 at p. 2) The Joint Advocates referred to 
the current method of calculating the cyclic degradation coefficient in 
appendix M1 \40\ and cited a research paper \41\ to highlight the 
issues in this calculation methodology. (Id.) Daikin pointed out the 
unsuitability of load-based tests for capturing cyclic losses, by 
stating that the cyclic tests in appendix M1 are executed with dry 
indoor coils since it is not easy to measure briskly changing moisture 
content during these tests. (Daikin, No. 16 at p. 6) Daikin added that 
for load-based cyclic tests, the coils will get wet, which will lead to 
concerns with the repeatability and reproducibility of capturing cyclic 
losses using load-based methods. (Id.)
---------------------------------------------------------------------------

    \40\ Sections 3.5 and 3.8 of appendix M1 contain provisions for 
conducting optional cooling and heating cyclic tests. These cyclic 
tests are used to determine the Coefficient of Degradation (``CD''), 
which is incorporated into the calculation of SEER2 and HSPF2, to 
account for any compressor cycling losses. If the optional cyclic 
tests are not conducted, appendix M1 requires use of the default CD 
value of 0.25. However, for the majority of single- and two-stage 
systems, a lower CD can be achieved when completing the optional 
cyclic tests, which results in higher SEER2 and HSPF2.
    \41\ Dhumane, Rohit; Qiu, Tianyue; Ling, Jiazhen; Aute, Vikrant 
Chandramohan; Hwang, Yunho; Radermacher, Reinhard; Kirkwood, Allen 
Chad; and Esformes, Jack, ``Evaluating the Impact of the Measurement 
Setup on Cyclic Degradation Coefficient of Air Conditioning 
Systems'' (2018). International Refrigeration and Air Conditioning 
Conference. Paper 2012. Available at docs.lib.purdue.edu/iracc/2012.
---------------------------------------------------------------------------

(9) Other Factors Affecting System Energy Use
    In the January 2023 RFI, DOE requested comment on how load-based 
testing could be used to capture other parameters that affect energy 
use of CAC/HPs, particularly, but not limited to, defrost systems, 
operation of electric resistance heat, operation of fans during the 
shoulder season, and operation of crankcase heaters during off-mode 
hours. 88 FR 4091, 4101.
    In response, Rheem commented that most power consumption is 
accounted for in the off-mode test procedure,\42\ except fan-only 
operation, which may be difficult to capture in a load-based test since 
outside air is not introduced during operation. (Rheem, No. 12 at p. 5) 
AHRI commented that incorporation of the parameters and aspects 
mentioned by DOE would result in the need for new energy efficiency 
descriptors. (AHRI, No. 14 at p. 11) NYSERDA recommended that DOE adopt 
an average space heating capacity adjustment using a defrost 
degradation coefficient consistent with the provisions of a test 
procedure term sheet issued by the Appliance Standards and Rulemaking 
Federal Advisory Committee Commercial Unitary Air Conditioner and Heat 
Pump Working Group on December 15, 2022 (``2022 ASRAC CUAC and CUHP WG 
TP term sheet'').\43\ (NYSERDA, No. 9 at pp. 10-11) NYSERDA commented 
that the cyclic defrost tests in appendix M1 (at outdoor temperature of 
35 [deg]F) could still be applicable for evaluating the maximum defrost 
degradation. (Id.)
---------------------------------------------------------------------------

    \42\ Section 3.13 of appendix M1 outlines the procedure to 
determine off-mode average power ratings.
    \43\ On July 21, 2022, ASRAC chartered the CUAC and CUHP Working 
Group to negotiate term sheets on the test procedure and energy 
conservation standards for CUACs and CUHPs. On December 15, 2022, 
the Working Group completed a term sheet for the test procedure, 
which is available at www.regulations.gov/document/EERE-2022-BT-STD-0015-0065.
---------------------------------------------------------------------------

(c) Commenter Conclusions Regarding Load-Based Testing
    In general, almost all commenters pointed toward several issues 
with load-based testing that make it infeasible for adoption as a 
regulatory test method at this time. Carrier commented that it is 
strongly opposed to DOE adopting any of the load-based testing 
procedures described in the January 2023 RFI since current research on 
these methods needs to be finalized before DOE incorporates them into 
the test procedure. (Carrier, No. 5 at p. 2) Daikin pointed out that 
while load-based testing may be appropriate when used as a CVP (similar 
to how it is used for VRF products in AHRI 1230-2021: 2021 Standard for 
Performance Rating of Variable Refrigerant Flow Multi-Split Air-
Conditioning and Heat Pump Equipment (``AHRI 1230-2021'')),\44\ it is 
not suitable for evaluating unit efficiency and capacity. (Daikin, No. 
16 at p. 1) Daikin encouraged DOE to make modifications to the existing 
appendix M1 and adopt a CVP in appendix M1 that is similar to the VRF 
CVP, but not to adopt load-based testing as the primary regulatory test 
method. (Id. at pp. 1-2) Similary, AHRI commented that although it will 
support the improvement of load-based testing as an academic pursuit, 
load-based testing has not yet developed sufficiently such that it may 
be used for regulatory purposes. (AHRI, No. 14 at p. 7) AHRI further 
commented it expects DOE to carefully evaluate all the information 
manufacturers have to report for certification of their products and 
also evaluate the burden for this reporting and testing if planning to 
adopt load-based testing. (Id.) NEEA stated that although it has 
published several articles that question the rank order performance 
ratings evaluated from fixed-speed testing, there is currently no clear 
evidence that exhibits the advantages of load-based testing. (NEEA, No. 
13 at p. 1) NYSERDA commented that regarding the adoption of load-based 
methods for regulatory purposes, DOE should account for products such 
as coil-only systems, split system ACs or HPs with coil blowers, and 
multi-split products.\45\ (NYSERDA, No. 9 at p. 6) NYSERDA further 
commented that there is still more work that needs to be done in order 
to make load-based testing suitable for DOE regulatory purposes. (Id.) 
Finally,

[[Page 24220]]

NYSERDA stated that although it supports a feasible and representative 
load-based approach, developing a procedure could be challenging. (Id. 
at p. 4) The CA IOUs encouraged DOE to collaborate with stakeholders to 
move to a test procedure that requires units to operate under native 
controls, but recognized that an industry-wide transition to load-based 
testing will be time consuming and cost intensive. (CA IOUs, No. 10 at 
pp. 1-2) The Joint Advocates commented that load-based testing 
methodologies would provide better information on the field operation 
of a CAC/HP, in comparison to the fixed-speed tests currently in 
appendix M1. (Joint Advocates, No. 8 at pp. 1-2) The Joint Advocates 
referred to how the native controls testing in DOE's Cold Climate Heat 
Pump Technology Challenge (``DOE CCHP Tech Challenge'') \46\ was 
informed by the results of the steady-state regulatory tests,\47\ and 
suggested that DOE could adopt a similar provision for both cooling and 
heating tests, in its amended load-based test procedure. (Id.)
---------------------------------------------------------------------------

    \44\ See www.ahrinet.org/system/files/2023-06/AHRI_Standard_1230-2021.pdf.
    \45\ DOE believes that NYSERDA made this comment owing to the 
fact that SPE07 does not explicitly state that it is applicable to 
these product types.
    \46\ On May 19, 2021, DOE, in conjunction with EPA and NRCan, 
announced the DOE CCHP Tech Challenge as part of the Energy, 
Emissions and Equity (``E3'') Initiative. The specification of the 
DOE CCHP Tech Challenge is available at www.energy.gov/sites/default/files/2021-10/bto-cchp-tech-challenge-spec-102521.pdf.
    \47\ As an example, if a heating capacity of 18,000 Btu/h was 
measured during the H11 regulatory test, the native 
controls ``Min/Mild'' test would apply an equivalent 18,000 Btu/h 
cooling load to the indoor room`s conditioning equipment.
---------------------------------------------------------------------------

    Instead of wholesale adoption of a load-based method, comments 
received on the January 2023 RFI pointed toward consensus preference 
for a limited form of load-based testing to verify steady-state 
regulatory test performance under native controls (i.e., a CVP). 
Samsung, Lennox, AHRI, NYSERDA, NEEA, and Rheem all encouraged DOE to 
adopt a CVP that would ensure settings used during steady state tests 
are representative of those during native controls operation. (Samsung, 
No. 11 at pp. 1-2; Lennox, No. 6 at p. 3; AHRI, No. 14 at p. 7; 
NYSERDA, No. 9 at p. 5; NEEA, No. 13 at p. 3; Rheem, No. 12 at p. 3) 
Specifically, Lennox stated that while steady state testing currently 
used in appendix M1 should continue to be used, a CVP can be used to 
validate the settings used to test variable capacity systems. (Lennox, 
No. 6 at p. 3) AHRI commented that use of a CVP would be more 
repeatable and less burdensome than using load-based testing for direct 
measurement of performance, adding that CVPs have been used for other 
product categories and may need some adapatation for application to 
CAC/HPs. (AHRI, No. 14 at p. 9) Additionally, AHRI referred to a study 
it co-sponsored with NEEA to collect representative field data, which 
was expected to conclude at the end of winter 2022/2023. (Id. at p. 9) 
NYSERDA described the CVP used in AHRI 1230-2021 for VRFs and 
recommended that DOE adopt something similar to it. (NYSERDA, No. 9 at 
p. 5) NYSERDA further recommended that DOE adopt the CVP outlined in 
ENERGY STAR Spec V6.1 for the low ambient heating steady-state tests in 
appendix M1, namely H32 and H42. (Id. at pp. 5-6) 
NYSERDA referred to how the wet bulb test conditon in the H4 heating 
test had increased from 3 [deg]F to 4 [deg]F, which would decrease test 
burden for labs if they conduct a load-based CVP outlined in ENERGY 
STAR Spec V6.1. (Id.) NYSERDA further encouraged DOE to adopt a 
``budget'' method to account for variability in critical parameters 
during a CVP, and recommended incorporation of a CVP for validating the 
H11 (heating minimum) test, and also a minimum-speed CVP at 
outdoor dry bulb temperature of 17 [deg]F.\48\ (Id.) NYSERDA commented 
that performance of units at part-load at milder temperatures has a 
pronounced impact on the overall seasonal energy efficiency, especially 
when considering the intersection of low-speed loads beween 17 [deg]F 
and 47 [deg]F, highlighting that this impact was not fully considered 
in implementation of the ``Min/Mild'' CVP in the specifications of the 
DOE CCHP Tech Challenge. (Id. at p. 6) NEEA referred to the two types 
of CVPs as descibed in section III.F.1.b. and commented the results of 
a study it performed called into question whether a CVP can truly 
capture the impact of native controls on unit performance.\49\ (Id. at 
pp. 3-6) Hence, NEEA commented that DOE needs additional test data to 
make any claims that CVP testing fully addresses the impact of native 
control logic on unit performance. Id. NEEA pointed to the 
representativeness study \50\ being conducted by NEEP on three ducted 
and three non-ducted heat pumps, tested using AHRI 210/240 and SPE07, 
and stated that this study could potentially indicate what elements of 
a CVP are critical to include in a revised appendix M1, and also inform 
other issues raised by DOE in the RFI, namely the repeatability, 
reproducibility, and test burden of load-based methods when compared to 
fixed-speed testing. (Id. at pp. 2-3)
---------------------------------------------------------------------------

    \48\ Currently, appendix M1 only has a full-speed heating test 
at an ambient outdoor temperature of 17 [deg]F, i.e., the 
H32 test.
    \49\ Bruce Harley, Mark Alatorre, Christopher Dymond, Gary 
Hamer, ``CSA EXP07: Ongoing Progress, Lessons Learned, and Future 
Work in Load-based Testing of Residential Heat Pumps'' (2022). 
Purdue University. Available at docs.lib.purdue.edu/cgi/viewcontent.cgi?article=3455&context=iracc.
    \50\ In its comment, NEEA pointed out that preliminary analysis 
and data from this study will be available probably by July 2023, 
but at the time of writing this NOPR, neither the analysis, nor the 
data, has become available.
---------------------------------------------------------------------------

    To summarize, comments from the January 2023 RFI indicated that 
stakeholders preferred a CVP for validating the performance of variable 
capacity systems, rather than adopting a load-based testing method for 
regulatory purposes.
(d) DOE's Conclusion and Approach
    As mentioned previously, AHRI and other relevant stakeholders, 
including DOE, participated in the development of revised AHRI test 
standards to address the issues raised in the January 2023 RFI. In 
particular, the issues outlined in the aforementioned comments in 
regard to the representativeness of fixed-speed testing for variable 
speed systems were discussed in detail and consensus was developed on a 
CVP approach. Based on review of the stakeholder comments received in 
response to the January 2023 RFI, specifically that it has not yet been 
conclusively demonstrated that such methods have sufficient 
repeatability and reproducibility to be the basis of direct measurement 
of system performance, DOE has tentatively concluded that use for 
direct measurement of performance for regulatory purposes would not be 
suitable at this time. However, DOE also tentatively concludes that a 
CVP would be necessary to ensure that fixed-speed settings of variable 
speed systems would be achieved using native (unfixed) control. Thus, 
DOE proposes to adopt the CVP outlined in AHRI 210/240-202X Draft and 
AHRI 1600-202X Draft through incorporation by reference. The next 
section discusses the aforementioned CVP approach.
(e) CVP Proposal
    Appendix I of the AHRI 210/240-202X Draft and AHRI 1600-202X Draft 
includes a CVP to verify variable capacity system operation. The CVP is 
intended to validate whether override of modulating components in 
regulatory tests is consistent with native control operation. The CVP 
verifies: (1) compliance with the variable capacity compressor system 
definition; and (2) consistency of fixed-position settings for the 
compressor and indoor fan used in steady-state regulatory tests with 
native control operation.
    The CVP in appendix I includes a set of three cooling tests 
conducted in

[[Page 24221]]

series with intervening transition periods, including the full, 
intermediate, and minimum capacities. The CVP uses a modified VBL \51\ 
approach to simulate space condition (temperature and humidity) 
response to system operation, as explained in section III.F.1.b.3 of 
this document. Similarly, the CVP also includes three or four heating 
tests conducted in series for CHPs--the fourth test is specified for 
those CHPs for which performance at 5 [deg]F outdoor temperature is 
measured. Similar to the cooling tests, the heating tests have 
intervening transition periods between the full, intermediate, and 
minimum capacity test intervals.
---------------------------------------------------------------------------

    \51\ The modified VBL in the CVP differs from the VBL in SPE07. 
For the modified VBL, the building load used in the equations does 
not depend on the indoor temperature and is a fixed function of 
target indoor and outdoor temperatures.
---------------------------------------------------------------------------

    For the three cooling tests, the indoor return air conditions are 
controlled by equations I1-I6 and paragraph I4.1.8 in AHRI 210/240-202X 
Draft and AHRI 1600-202X Draft--i.e., the indoor return air wet bulb 
temperature is set at 67 [deg]F, and the indoor return air dry bulb 
target varies near 80 [deg]F based on the varying system capacity and 
calculated building load. The temperature setpoint of the control of 
the system being tested is set throughout the series of tests near 80 
[deg]F with some adjustment to account for control bias and offset. The 
outdoor dry bulb temperature is held constant at three different levels 
during the three cooling-mode tests, but is controlled to ramp down 
from higher to lower temperature as the cooling mode CVP transitions 
between the full load, intermediate load, and low load test intervals.
    For the heating tests, the indoor return air conditions are 
controlled by equations I7-I13 in AHRI 210/240-202X Draft and AHRI 
1600-202X Draft. The indoor return air dry bulb temperature varies near 
70 [deg]F based on the varying system capacity and calculated building 
load. The temperature setpoint of the control of the system being 
tested is set throughout the series of tests near 70 [deg]F with some 
adjustment to account for control bias and offset. The outdoor dry bulb 
temperature is held constant at three or four different levels, but is 
controlled to ramp up from lower to higher temperature as the heating 
mode CVP transitions between the full load (at 5 [deg]F if applicable 
and 17 [deg]F outdoor dry bulb temperature), intermediate load, and low 
load test intervals.
    As noted, part of the CVP (the intermediate-load test) determines 
compliance with the variable-capacity compressor system definition. 
AHRI 210/240-202X Draft and AHRI 1600-202X Draft define variable 
capacity compressor systems as:
    Variable capacity compressor system means an air conditioner or 
heat pump that has either (a) a compressor that uses a variable speed 
drive or inverter to vary the compressor speed by four or more speeds 
in each mode of operation (i.e., cooling/heating), or (b) a digital 
compressor that mechanically modulates output using a duty cycle; and 
which controls the system by monitoring system operation and 
automatically modulating the compressor output, indoor air flow and 
other system parameters as required in order to maintain the indoor 
room temperature.
    To determine compliance with the definition, the CVP results 
obtained from the intermediate load interval is evaluated based on 
section I4.3.1 of appendix I in in AHRI 210/240-202X Draft, which 
requires that the standard deviation of the system power does not 
exceed 20 percent of the mean system power. For a system that does not 
comply with this compressor power (or outdoor unit power) requirement, 
and cycles between off and a single stage or capacity level (+/-15 
percent), the system is classified as a variable capacity certified, 
single capacity system. If this occurs for just one of the operating 
modes (heating or cooling) for a heat pump, the system is classified as 
variable capacity certified, single capacity for both modes. 
Additionally, a system that does not comply with the compressor power 
(or outdoor unit power) requirement is not classified as Variable 
Capacity Certified, Single-Capacity, and cycles between more than one 
stage or capacity level (+/-15 percent) is classified as a Variable 
Capacity Certified, Two-Capacity System. Again, this designation 
applies for both modes for a heat pump, even if the operation meets 
this description for one of the modes. These terms are defined in AHRI 
210/240-202X Draft and AHRI 1600-202X Draft as:
    Variable Capacity Certified, Single Capacity System means a system 
that is certified as a variable capacity system but demonstrates 
Single-Capacity System behavior during the Variable Capacity 
Determination CVP in appendix I.
    Variable Capacity Certified, Two Capacity System means a system 
that is certified as a variable capacity system, but demonstrates Two-
Capacity System behavior during the Variable Capacity Determination CVP 
in appendix I.
    Use of the Intermediate Load CVP test and its determination of 
compliance with the variable speed system definition in DOE enforcement 
testing is discussed in section III.K.2 of this document.
    The full-load and low-load intervals of the CVP determine if the 
fixed-speed settings for the compressor and indoor fan used during the 
regulatory test are consistent with those that occur when the unit is 
allowed to modulate under native controls, as it maintains the indoor 
room dry bulb temperature. During the cooling mode CVP,\52\ the indoor 
return air wet bulb temperature is maintained at 67.0 [deg]F, but the 
updated target indoor dry-bulb temperature setpoint for the indoor room 
reconditioning system, RAT(t + [Delta]t), is updated based on equations 
I4-I6 of AHRI 210/240-202X Draft and AHRI 1600-202X Draft, as shown 
below:
---------------------------------------------------------------------------

    \52\ For brevity, only cooling mode is explained in the NOPR, to 
illustrate the 2nd part of the CVP.
[GRAPHIC] [TIFF OMITTED] TP05AP24.049

---------------------------------------------------------------------------
Where,

RAT(t) = the current indoor dry-bulb temperature setpoint for the 
indoor room reconditioning system
Qs = the net sensible cooling capacity provided by the unit under 
test in the current time step, as determined by air-side 
measurements (see note below)
[Delta]t = the time interval for updating the indoor room 
reconditioning system controller setpoint, in h
C = the simulated thermal capacitance of the building interior, in 
units of Btu/[deg]F, given by
[GRAPHIC] [TIFF OMITTED] TP05AP24.050

VLs(Tj) = the sensible cooling portion of the modified VBL for 
target outdoor ambient dry-bulb temperature for each interval.

    The magnitude of VLs(Tj) is directly proportional to the certified 
cooling

[[Page 24222]]

capacity at 67 [deg]F outdoor ambient-dry bulb temperature--i.e., the 
Flow test, and the target SHR from the Flow 
regulatory tests, as illustrated in equations I1 and I3 of AHRI 210/
240-202X Draft and AHRI 1600-202X Draft. Thus, this illustrates that 
the modulation of the compressor speed setting and indoor air flow rate 
is verified against those used in the regulatory tests, as the unit 
tries to maintain the indoor dry-bulb temperature.
    DOE proposes that load-based testing will be not part of the test 
procedure required for each test for any CAC/HP products. DOE 
acknowledges that the CVP approach outlined in appendix I of the 
relevant AHRI drafts represents industry consensus regarding the 
verification of compliance of systems with the variable capacity system 
definition, and to verify the consistency of fixed-speed settings of 
compressor and indoor fan with native control operation as part of 
enforcement. DOE considers that this CVP approach will provide a more 
representative test procedure for variable speed systems operating in 
the field, because it provides a tool to verify that the compressor 
speed settings and indoor air fan settings used in regulatory tests are 
representative of native-control operation as the unit operates to 
maintain the thermostat setpoint, i.e., indoor dry-bulb temperature. 
Therefore, DOE is proposing to incorporate by reference appendix I of 
the AHRI 210/240-202X Draft to support enforcement associated with 
testing conducted in accordance with appendix M1, and to incorporate by 
reference appendix I of the AHRI 1600-202X Draft to support enforcement 
associated with testing conducted in accordance with appendix M2. This 
is discussed in more detail in section III.K.2 of this document.
2. Low-Temperature Heating Performance
    In the January 2023 RFI, DOE requested comment on several issues 
regarding the foundational work needed to improve the appendix M1 test 
procedure to better account for CAC/HP performance in cold climates, as 
recommended by NYSERDA during the previous rulemaking cycle that 
culminated in the October 2022 Final Rule. 88 FR 4091, 4103. In 
response to the low-temperature heating performance issues raised in 
the January 2023 RFI (i.e., whether to make the H4 heating tests 
mandatory, whether the heating load line should be based on heating or 
cooling capacity, and methods of heat pump sizing), DOE received 
several comments regarding the establishment of a clear definition for 
a CCHP as well as potential ways of reporting performance for CCHPs. 
These aforementioned topics are detailed in separate sections below.
(a) CCHP Definition
    In response to the January 2023 RFI, several stakeholders commented 
in support of establishing a definition for products specifically 
engineered to provide comfort heating at low ambient conditions (i.e., 
CCHPs). Daikin recommended that DOE work with stakeholders to establish 
a clear definition for CCHPs, whether as a separate product class or an 
optional set of recognition criteria. (Daikin, No. 16 at p. 9) 
Similarly, AHRI commented in support of a uniform definition for 
products specifically engineered to provide comfort heating at low 
ambient conditions. (AHRI, No. 14 at pp. 2-3) AHRI commented that 
engagement from all stakeholders would be necessary to overcome the 
shortcomings of previous efforts to develop a definition for CCHPs. 
(Id.)
    Additionally, in forming a DOE definition for CCHPs, AHRI requested 
it be acknowledged that (1) not all U.S. consumers would benefit from 
higher-tech CCHPs, and (2) the topography of the United States makes it 
difficult to assign regions that would correlate heating degree days in 
the same way as is done for split-system air conditioners, as shown by 
Figure 1 \53\ of AHRI's response to the January 2023 RFI. (AHRI, No. 14 
at p. 3) Referring to Figure 1, AHRI commented that it is easy to see 
the cooling degree day division between the North and South, as in 
effect today, and that heating degree days, on the other hand, meander 
and are very closely tied to elevation and longitude (to some extent). 
(Id.)
---------------------------------------------------------------------------

    \53\ Figure 1 of AHRI's response to the January 2023 RFI shows 
average annual cooling and heating degree days in the contiguous 
United States from 1901-2000, using National Centers for 
Environmental Information (``NCEI'') data compiled by the National 
Oceanic and Atmospheric Administration (``NOAA''). (AHRI, No. 14 at 
p. 3) A degree day is equivalent to one day with an average 
temperature that is one degree above or below 65 [deg]F.
---------------------------------------------------------------------------

    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several issues raised in the January 2023 RFI when 
considering updated versions of industry standards, including the topic 
of a clear definition for CCHPs. DOE notes that AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft both include a new definition for CCHP as 
shown below:
    Cold climate heat pump means a heat pump for which both low-
temperature compressor cut-out and cut-in temperatures are specified to 
be less than 5 [deg]F and for which capacity for the H4full 
test (at 5 \0\F) is certified to be at least 70 percent of the capacity 
for the nominal full capacity test conducted at 47 \0\F 
(H1Full or H1Nom).
    DOE surmises that the CCHP definition provided in the relevant AHRI 
drafts represents industry consensus regarding a uniform definition for 
products specifically engineered to provide comfort heating at low 
ambient conditions. DOE has also tentatively determined that the 
definition includes the relevant criteria to characterize CCHP 
performance, specifically low-temperature cut-out and cut-in 
temperature settings to allow operation down to at least 5 [deg]F 
ambient temperature, and maintenance of heating capacity at low 
temperatures. Therefore, DOE is proposing to incorporate by reference 
the definition of a cold climate heat pump provided in the AHRI 210/
240-202X and AHRI 1600-202X Drafts, at appendix M1 and appendix M2, 
respectively.
(b) Mandatory H4 Heating Tests for CCHPs
    While the H4 heating tests provide meaningful information and more 
representative ratings for products designed specifically for low 
temperature operation, in the January 2023 RFI, DOE noted that the 
current appendix M1 test procedure includes H4 heating tests as 
optional tests, as they may not be appropriate for all HPs. 88 FR 4091, 
4103. Currently, appendix M1 allows the performance at 5 [deg]F to be 
extrapolated based on tests conducted at 17 [deg]F and 47 [deg]F (i.e., 
using the H32 and H12 tests, respectively) for 
HPs that are not tested at the H4 heating condition.
    As such, in the January 2023 RFI, DOE requested comment on whether 
it would be appropriate to make the H4, H42, or 
H43 heating tests in appendix M1 mandatory for either all or 
a subset of HPs (e.g., CCHPs) in order to produce more representative 
ratings that account for system performance at 5 [deg]F. 88 FR 4091, 
4103. In the case of mandating the H4 heating tests for only a subset 
of HPs, DOE requested information on what characteristics would 
represent a clear delineation to distinguish such models from others. 
(Id.) DOE also requested information on the prevalence of test chambers 
capable of testing CHPs at an outdoor ambient temperature of 5 [deg]F. 
(Id.)
    In response, AHRI and Daikin recommended that the H4 tests be 
mandated only for variable speed HPs for which the compressor speed at 
the H4 condition was different from that at the H1 and H3 condition. 
(AHRI, No. 14 at p. 13; Daikin, No. 16 at p. 9) Daikin

[[Page 24223]]

asserted that it does not make sense to require the H4 tests for any HP 
that does not change speed, because, for single- and two-stage HPs, 
performance at 5 [deg]F can be extrapolated based on existing test data 
since compressor performance is linear for those products. (Daikin, No. 
16 at p. 9) Daikin clarified that the mandatory H4 tests would be 
applicable even for a variable speed HP where the manufacturer is 
targeting the southern United States as a market. (Id.)
    Like AHRI and Daikin, Rheem commented against mandating the H4 
tests for single- and two-stage equipment; however, Rheem neither 
supported nor opposed mandating the H4 tests for variable speed 
systems. (Rheem, No. 12 at p. 7) Rheem noted that the current test 
procedure in appendix M1 allows linear extrapolation of heat pump 
performance at outdoor temperatures colder than 17 [deg]F using 
equations 4.2.1-4 and 4.2.1-5 for HPs having a single-speed compressor, 
and using equations 4.2.2-3 and 4.2.2-4 for HPs having a two-capacity 
compressor. (Id.) As such, Rheem commented that the test procedure in 
appendix M1 reliably indicates heat pump performance in cold climates 
for single- and two-stage equipment. (Id.) However, for variable speed 
systems, Rheem acknowledged that, in addition to compressor speed, 
indoor and outdoor airflow rates may change, which may bring the 
accuracy of linear extrapolation into question for these systems. (Id.)
    Lennox commented against the idea of making the H4 tests mandatory 
for any HPs, contending that consumer needs in many areas of the United 
States with milder climates do not need the capability of a CCHP and, 
thus, should not require the additional test burden associated with 
mandatory H4 tests. (Lennox, No. 6 at p. 4)
    NEEA recommended making the H4 heating tests mandatory for all HPs, 
but not required within the test metric, contending that this would 
result in a more representative assessment of cold climate efficiency 
and capacity across all HPs. (NEEA, No. 13 at pp. 7-8) Further, NEEA 
commented that in conversations with industry representatives, NEEA has 
received indications that many manufacturers already have test chambers 
that can test down to 5 [deg]F, suggesting that the testing 
infrastructure is already in place to implement a mandatory requirement 
for the H4 heating tests. (Id.)
    NEEA also recommended that for units required to test at part-load 
conditions (e.g., CCHPs), DOE require reporting unit COP at part load 
conditions. (NEEA, No. 13 at p. 7) Specifically, NEEA recommended that 
DOE require the reporting of COP at FLow (at 67 [deg]F) and 
H1Low (at 47 [deg]F) for units that are required to test at 
those conditions. (Id.) NEEA commented that, by requiring manufacturers 
to report this data in a consistent format, contractors will be able to 
make better-informed choices about equipment that works in their 
climate, and utility companies will know which heat pumps to recommend 
(i.e., incentivize) to their customers. (Id.) NEEA pointed to DOE's 
CCHP Tech Challenge specifications as an example of the kind of 
information that consumers and utilities need in order to make informed 
decisions for their desired region and application. (Id.)
    NYSERDA encouraged DOE to make H42 tests mandatory, but 
only for United States North climate regions, at air-entering outdoor 
unit temperatures of 5 [deg]F dry bulb and 4 [deg]F (max) wet bulb. 
(NYSERDA, No. 9 at p. 4) NYSERDA explained that a precedence for 
mandatory H42 tests was recently codified in Canada's 
Regulations Amending the Energy Efficiency Regulations, 2016 (Amendment 
17), published in the Canada Gazette, Part II, on December 7, 2022.\54\ 
(Id.) NYSERDA noted that mandatory reporting requirements to National 
Resources Canada (``NRCan'') as of January 1, 2023, are as follows: (a) 
a Region V HSPF2; (b) information that indicates whether the results of 
the appendix M1 H4 test, if conducted, were included in the calculation 
of the Region V HSPF2; (c) heating capacity at 5 [deg]F if the H4 test 
was conducted; and (d) COP at 5 [deg]F if the H4 test was conducted. 
(Id.) Further, NYSERDA noted that, in Canada, HPs manufactured on or 
after January 1, 2025, must be tested at the H4 test conditions 
prescribed in appendix M1, and that mandatory reporting requirements to 
NRCan for the H4 test conditions include heating capacity at 5 [deg]F 
and COP at 5 [deg]F. (Id.) More broadly, NYSERDA recommended that DOE 
should study more carefully whether the incentives to conduct the 
optional H42 tests on good-performing cold climate equipment 
(because it would increase the HSPF2 rating, particularly in region V) 
are enough to ensure that most manufacturers would conduct the test to 
demonstrate that benefit. (Id.)
---------------------------------------------------------------------------

    \54\ See canadagazette.gc.ca/rp-pr/p2/2022/2022-12-21/html/sor-dors265-eng.html.
---------------------------------------------------------------------------

    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed issues raised in the January 2023 RFI, including the 
topic of mandatory H4 heating tests for either all or a subset of HPs, 
when developing updated industry standards in AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft. DOE notes that these draft industry standards 
include a footnote to Table 7 (i.e., the required tests table), 
applicable to all product types, requiring the H4full 
heating test for all products that meet the definition of a CCHP. DOE 
surmises that this new mandate for all products certified as a CCHP in 
the relevant AHRI drafts represents industry consensus regarding 
whether it would be appropriate to make the H4 heating tests mandatory 
for either all or a subset of HPs. DOE has tentatively determined that 
the H4 heating tests are representative of CCHP operation. Therefore, 
in addition to its proposal to incorporate the CCHP definition as 
discussed in section III.E.2.a of this document, DOE is proposing to 
incorporate by reference the mandate for products certified as CCHP to 
conduct the H4 heating tests (either the H4, H42, or 
H43 heating test, as applicable) provided in the AHRI 210/
240-202X Draft and AHRI 1600-202X Draft, at appendix M1 and appendix 
M2, respectively.
(c) Heating Load Line and Sizing for CCHPs
    In a supplemental notice of proposed rulemaking (``SNOPR'') 
regarding CAC/HP test procedures published on August 24, 2016 (``August 
2016 SNOPR''), DOE noted that most heat pump units in the field are 
sized based on cooling capacity as opposed to heat pump capacity, 
consistent with the Air Conditioning Contractors of America (``ACCA'') 
Manual S provisions. 81 FR 58163, 58188. Subsequently, in the January 
2017 Final Rule, DOE revised appendix M1 such that the determination of 
the heating load line was based on cooling capacity rather than heating 
capacity. 82 FR 1426, 1453-1454. In the January 2023 RFI, DOE explained 
that part of the motivation for this change was that the previous 
approach of heating load line determination based on the nominal 
heating capacity (``H1N capacity'') provided little 
incentive to design for good heat pump performance, since low 
H1N capacity resulted in a low load line and generally 
better HSPF2. 88 FR 4091, 4103. DOE explained that sizing based on 
cooling capacity is consistent with trends for sales distributions of 
heat pumps, which have had greater adoption in milder climates than 
cold climates.\55\ (Id.) However, DOE also

[[Page 24224]]

expressed awareness that NRCan has proposed alternatives for sizing 
CAC/HPs, in its ``Air Source Heat Pump Sizing and Selection Guide,'' 
\56\ which provides four different approaches with varying emphasis on 
heating vs. cooling, ranging from sizing based on cooling to sizing 
such that the heat pump can meet the design heating load without need 
for resistance auxiliary heat. (Id.) In the January 2023 RFI, DOE 
acknowledged that in cold climates, sizing a heat pump for heating may 
be more appropriate than sizing for cooling. (Id.) Further, DOE 
acknowledged that accurate information regarding heat pump cold-weather 
performance is relevant for selection of the best heat pumps for cold 
climates. (Id.) Nevertheless, DOE found it unclear how a test procedure 
using a heating load line based on heating performance would 
incentivize good heating performance, particularly if it is based on 
heating performance at 47 [deg]F, which is not a heating design 
temperature, and noted that this is the same issue that led DOE to move 
to the cooling-capacity-based heating load line in appendix M1 in the 
January 2017 Final Rule.\57\ (Id.) As a result, in the January 2023 
RFI, DOE requested comment on whether the test procedure for CCHPs 
should use a heating load line based on heating performance, and how 
such an approach could be implemented such that it does not weaken the 
incentive for good cold-temperature heating performance.
---------------------------------------------------------------------------

    \55\ Residential Energy Consumption Survey (``RECS'') 2020 data 
shows that electric heat pumps represent 29 percent of primary space 
heating equipment in homes in the South region, which is a higher 
number as compared to the 14 percent for US overall. See 
www.eia.gov/consumption/residential/data/2020/hc/pdf/HC%206.8.pdf.
    \56\ The ``Air Source Heat Pump Sizing and Selection Guide'' was 
written by NRCan in response to stakeholder requests for consistent 
guidance for sizing ASHPs according to the design heating or cooling 
load and intended use as well as identifying the appropriate system 
according to the installation and application. The four methods of 
sizing in the Guide are Options 4A (Emphasis on Cooling), 4B 
(Balanced Heating and Cooling), 4C (Emphasis on Heating) and 4D 
(Sized on Design Heating Load). The ``Air Source Heat Pump Sizing 
and Selection Guide'' is available at publications.gc.ca/collections/collection_2021/rncan-nrcan/M154-138-2020-eng.pdf.
    \57\ See 82 FR 1426, 1453-1459 of the January 2017 Final Rule.
---------------------------------------------------------------------------

    In response, NYSERDA commented that sizing for cooling mode in 
climates where HPs will increasingly be relied upon to provide full 
home heat is not an appropriate approach to ensure that the right 
equipment is sized and selected, and suggested that a regional approach 
to HSPF2 ratings should be considered for CCHPs to allow for the 
prioritization of design heating performance. (NYSERDA, No. 9 at p. 2) 
NYSERDA commented in support of prioritizing sizing based on design 
heating loads at design temperatures as low as -4 [deg]F, specifically 
pointing to the NRCan ``Air Source Heat Pump Sizing and Selection 
Guide'' mentioned previously. (Id.) Citing the NEEP ``Guide to Sizing & 
Selecting Air-Source Heat Pumps in Cold Climates,'' \58\ NYSERDA 
explained that installers are recommended to match system heating 
capacity (minus any reliance on auxiliary heat) at design temperatures 
within 100-115 percent of the estimated heating load. (Id.) Further, 
NYSERDA commented that in partnership with electric utilities in New 
York, NYSERDA has designed a tool for residential buildings capable of 
demonstrating that a CCHP sized for heating load may be considered to 
meet an alternate compliance method for the mechanical design 
requirements under the 2020 Energy Conservation Construction Code of 
New York State, which would typically apply to the International Energy 
Conservation Code (``IECC'') as well.\59\ (Id.) NYSERDA noted that the 
tools and guidance around sizing for heating load were developed to 
ensure successful installations of CCHPs and grew out of market needs 
for this information. NYSERDA pointed to a DOE-sponsored market survey 
conducted of 156 ductless HP (single-split systems as defined in 
appendix M1) owners in Juneau, Alaska, that confirmed owners place 
emphasis on design heating loads while prioritizing climate, reducing 
fossil fuel usage, and lowering heating costs.\60\ (Id.) The survey 
results showed that the ability to have air conditioning was ranked the 
lowest in terms of owners' priorities, that about 93 percent of 
homeowners expressed satisfaction with their decision to install 
ductless HPs, and that most respondents viewed ductless HPs as products 
that would entirely replace or significantly reduce the use of other 
heating sources.
---------------------------------------------------------------------------

    \58\ See neep.org/sites/default/files/resources/ASHP%20Sizing%20%26%20Selecting%20-%208x11_edits.pdf.
    \59\ See cleanheat.ny.gov/contractor-resources/.
    \60\ See cchrc.org/media/2020-Juneau-DHP-Survey-Final1.pdf.
---------------------------------------------------------------------------

    Aside from its suggested design for heating in cold climates, 
NYSERDA commented that it would not support changing the heating load 
line equations in appendix M1. (NYSERDA, No. 9 at pp. 2-3) NYSERDA 
reasoned that revising the rating procedure to account for heating 
sizing in the building heating load line equation would essentially 
suppress the heating load seen by HPs and reduce or minimize the 
assumed use of auxiliary electric heat in the HSPF bin model. (Id.) 
NYSERDA commented that this would have the impact of overstating the 
performance of systems that have poor capacity in cold weather 
conditions, and would reduce (not emphasize) the differences in HSPF 
between those systems and others that have high capacity at low outdoor 
temperatures. (Id.)
    The CA IOUs commented in support of NYSERDA's recommendation for 
assuming heat pump sizing based on the design heating load solely in 
heating-dominated regions. (CA IOUs, No. 10 at p. 4) Similarly, AHRI 
and Rheem both commented that they would support modifications to the 
test procedure to address the differences between the cooling and 
heating load profiles for colder climates. (AHRI, No. 14 at p. 13; 
Rheem, No. 12 at p. 7)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several issues raised in the January 2023 RFI, including 
the topic of the heating load line and sizing for CCHPs, when 
considering updated versions of industry standards. The information 
provided in the aforementioned comments was discussed in detail in the 
development of the AHRI 210/240-202X Draft and AHRI 1600-202X Draft, 
which include no exception for CCHPs to base the heating load line on 
heating performance rather than cooling performance. DOE surmises that 
the absence of such an exception in the relevant AHRI drafts represents 
industry consensus regarding whether the test procedure for CCHPs 
should use a heating load line based on heating performance, rather 
than cooling performance. Further, DOE has tentatively concluded that 
the aforementioned approach is appropriate for sizing of CCHPs and is 
consistent with DOE's position expressed in a prior rulemaking that the 
heating load line determination based on the nominal heating capacity 
(H1N capacity) provides little incentive to design for good heat pump 
performance, since low H1N capacity results in a low load line and 
generally better HSPF. (See 81 FR, 58164, 58186). This would hold true 
also if the heating load line was based on a different heating 
operating condition, e.g. capacity for 5 [deg]F outdoor temperature, 
since poor performance at the test point would lower the heating load 
line. Therefore, DOE is proposing to incorporate no exception for CCHPs 
to base the heating load line on heating performance rather than 
cooling performance (i.e., DOE proposes to retain the current size-for-
cooling approach) at both appendix M1 and appendix M2.

[[Page 24225]]

(d) Cold Climate Heating Metric of Interest, COPpeak
    Currently, the Federal energy conservation standards and 
certification, compliance, and enforcement provisions for CAC/HPs only 
require manufacturers to report the HSPF2 of HPs based on Region IV. 
However, DOE acknowledges that Region IV HSPF2 may not adequately 
represent the cold climate performance of such systems.
    To better represent the heating performance of HPs in cold 
climates, in response to the January 2023 RFI, NYSERDA commented in 
support of the use and publication of Region V HSPF2 in addition to 
Region IV HSPF2, and of designating Region V HSPF2 as a relevant ``cold 
climate'' heating metric of interest. (NYSERDA, No. 9 at p. 3) Table 1 
of NYSERDA's response summarizes the heating fractional bin hours for 
several U.S. cities in cold and very cold climate regions \61\ and 
compares them to the current Region IV heating fractional bin hours 
presented in Table 20 of appendix M1. (Id.) NYSERDA stated that, since 
the heating fractional bin hours in Region V are present across all 
bins compared to Region IV, for cities located in climate zones 
designated as subarctic/arctic by the IECC, weather data suggest a 
Region V HSPF2 is more appropriate for all cold climate regions and 
shows focusing only on Region IV HSPF2 does not benefit consumers in 
colder climates. (Id.)
---------------------------------------------------------------------------

    \61\ The heating fractional bin hours in Table 1 of NYSERDA's 
response are based on archived weather data accessed from National 
Renewable Energy Laboratory's (``NREL'') National Solar Radiation 
Database (``NSRDB'') and NREL's PSM v3 TMY weather data accessed 
from NSRDB.
---------------------------------------------------------------------------

    Similarly, AHRI commented in support of a test method for products 
specifically engineered to provide comfort heating at low ambient 
conditions. (AHRI, No. 14 at pp. 2-3) AHRI commented that engagement 
from all stakeholders would be necessary to overcome the shortcomings 
of previous efforts to develop testing methodologies for CCHPs. (Id.) 
Carrier also commented that all stakeholders could benefit from an 
update to appendix M1 that includes optional tests to improve the 
representativeness of products marketed as a CCHP. (Carrier, No. 5 at 
p. 1)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several issues raised in the January 2023 RFI when 
considering updated versions of industry standards, including the topic 
of test methods that accurately measure the cold climate heating 
performance of HPs. The information provided in the aforementioned 
comments was discussed in detail in the development of the AHRI 210/
240-202X Draft and AHRI 1600-202X Draft, which add a new test method in 
appendix L to measure the heating performance of HPs at low ambient 
temperatures. Rather than designate Region V HSPF2 as the relevant 
``cold climate'' heating metric of interest or requiring a separate 
test procedure for CCHPs, appendix L of the AHRI 210/240-202X and AHRI 
1600-202X Drafts include the calculation steps for a new heating 
performance metric, the peak load coefficient of performance 
(``COPpeak''), intended to provide an indication of total 
heating efficiency as applied under peak heating load conditions. 
Specifically, COPpeak conveys the total energy consumed by 
both the HP and supplemental heat when meeting the building load at 5 
[deg]F, calculated using the equation below:
[GRAPHIC] [TIFF OMITTED] TP05AP24.051

and BL(5) is the building load at 5 [deg]F, is the electrical power 
consumption of the heat pump during the H4Full test, and 
Full is the space heating capacity of the heat pump during the 
H4Full test.
    COPpeak provides the opportunity for manufacturers to 
make optional representations of their HPs, regardless of whether they 
are CCHPs, and is distinct from COP at the H4 testing conditions as it 
accounts for the additional resistance heat required to meet the 
building load under peak conditions. As such, COPpeak would 
be less than the tested COP at 5 [deg]F but greater than 1, for any HP 
with COP greater than 1 at 5 [deg]F.
    DOE surmises that the inclusion of COPpeak in the 
relevant AHRI drafts represents industry consensus regarding 
improvements to representations of HP performance at low ambient 
temperatures. DOE has tentatively determined that inclusion of 
COPpeak would allow for representative characterizations of 
HP performance at low ambient temperatures. Therefore, DOE is proposing 
to incorporate by reference COPpeak as an optional 
representation for manufacturers hoping to advertise their HPs' peak 
load performance, as outlined in appendix L of the AHRI 210/240-202X 
and AHRI 1600-202X Drafts, at appendix M1 and appendix M2, 
respectively.
3. Cut-Out and Cut-In Temperature Certification
    The calculation of HSPF2 in appendix M1 requires values for cut-out 
\62\ and cut-in \63\ temperatures (see, e.g., equation 4.2.1-3 in 
section 4.2 of appendix M1). For CAC/HPs that do not include the cut-
out and cut-in temperatures in their installation manuals, the 
manufacturer (or DOE, in the case of compliance testing) must provide 
the test lab with this information. In the January 2023 RFI, DOE 
explained that, based on lab testing, it has found manufacturers often 
use cut-out and cut-in temperatures in their HSPF2 calculations that 
are much lower than can be reasonably expected in the field--in some 
instances as low as -40 [deg]F. 88 FR 4091, 4105. DOE expressed concern 
in this finding because of a review of product literature for scroll 
compressors with model numbers Copeland ZP*3KE and ZP*5KE R-410A 
(typically used in CAC/HPs) that shows the lowest refrigerant 
evaporating temperature of these systems is no lower than -10 
[deg]F.\64\ (Id.)
---------------------------------------------------------------------------

    \62\ Cut-out temperature refers to the outdoor temperature at 
which the unit compressor stops (cuts out) operation.
    \63\ Cut-in temperature refers to the outdoor temperature at 
which the unit compressor restarts (cuts in) operation.
    \64\ Figure 7 in the operating bulletin of the Copeland ZP*3KE 
and ZP*5KE R-410A scroll compressors shows their evaporating 
envelope, clearly indicating that they should not be used below 
saturated suction temperatures of -10 [deg]F, implying that this 
should be set as the cut-out temperature. The bulletin is available 
at climate.emerson.com/documents/ae-1331-zp16-to-zp44k3e-zp14-to-zp61k5e-r-410a-1-5-to-5-ton-copeland-scroll-compressors-en-us-1571048.pdf.
---------------------------------------------------------------------------

    In the January 2023 RFI, DOE also shared findings, in testing, that 
the ambient temperatures at which a unit's control cuts out and cuts in 
may significantly differ from the control's specified temperatures. 88 
FR 4091, 4105. DOE acknowledged that this can be due to control 
component manufacturing variation. (Id.) However, DOE also explained 
that it can be due to sensors being located where

[[Page 24226]]

temperature deviates from that of the ambient air (e.g., downstream of 
the outdoor coil, which absorbs heat from the ambient air during heat 
pump operation). (Id.) As such, in the January 2023 RFI, DOE requested 
information on the range of cut-out temperatures for compressor 
operation of CAC/HPs. (Id.)
    In response, Rheem commented that a sufficient hysteresis, or 
difference between cut-in and cut-out temperatures, is necessary for 
reliable compressor operation and in some cases is prescribed by the 
compressor drive manufacturer. (Rheem, No. 12 at p. 8) The CA IOUs 
concurred with DOE's observation that the controls and sensors can 
significantly impact actual cut-in and cut-out temperatures and 
commented in support of DOE's investigation of cut-out and cut-in 
temperature certification, stating that the CA IOUs had observed 
similar discrepancies between cut-out temperatures listed in 
manufacturer installation/operations materials relative to those seen 
under native controls in laboratory testing of packaged terminal heat 
pumps. (CA IOUs, No. 10 at p. 4) The Joint Advocates encouraged DOE to 
consider adopting a cut-in and cut-out temperature validation test 
(instead of relying on manufacturer-provided values), if DOE determines 
that the discrepancies regarding cut-out and cut-in temperatures 
described earlier contributes to unrepresentative ratings of seasonal 
heating performance. (Joint Advocates, No. 8 at p. 3)
    NYSERDA also supported an approach to certify cut-out and cut-in 
temperatures and proposed that DOE consider recommendation 10 of the 
2022 ASRAC CUAC and CUHP WG TP term sheet. (NYSERDA, No. 9 at pp. 12-
13) Recommendation 10 suggests requiring manufacturers to certify cut-
out and cut-in temperatures to DOE or the absence thereof, and 
prescribes that DOE adopt a product-specific enforcement provision that 
includes a verification test based on the following method:
     Outdoor air temperature (``OAT'') is measured using an 
outdoor coil air sampler.
     Start at an OAT above but close to cut-out temperature.
     Ramp down OAT temperature at 1 [deg]F per 5 minutes.
     Wait for 5 minutes once unit shuts off. Cut-out 
temperature is the measured temperature with the unit turned off.
     Reverse temperature ramp and increase the temperature by 1 
[deg]F per 5 minutes.
     Wait for 5 minutes once the unit turns on. Cut-in 
temperature is the measured temperature with the unit turned on.
    NYSERDA further commented that recommendation 10 could be adapted 
for HPs in a manner that allows adjustment to the low temperature cut-
out factor specified in equation 4.2.1-3 of appendix M1, if DOE deems 
during its enforcement test that the measured cut-out and cut-in 
temperatures significantly deviate from manufacturer-certified values, 
thereby impacting the calculated HSPF2 value during the enforcement 
testing process. (NYSERDA, No. 9 at pp. 12-13)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several issues raised in the January 2023 RFI, including 
the topic of cut-out and cut-in temperature certification, when 
considering updated versions of industry standards. The information 
provided in the aforementioned comments was discussed in detail in the 
development of the AHRI 210/240-202X and AHRI 1600-202X Drafts, which, 
in the appendix K of their respective drafts, include a test applicable 
to all HPs to determine cut-out and cut-in temperatures (i.e., 
Toff and Ton respectively). Appendix K follows 
recommendation 10 of the 2022 ASRAC CUAC and CUHP WG TP term sheet and 
includes an accommodation for those test facilities incapable of 
reaching OATs below -22 [deg]F. For units with cut-out temperatures 
below -22 [deg]F tested in facilities that are incapable of reaching 
OATs below -22 [deg]F, appendix K instructs to (alternatively) end the 
test 5 minutes after the average outdoor coil air inlet temperature 
reaches and maintains the coldest achievable temperature below -22 
[deg]F, and to record Toff as this coldest achievable 
temperature below -22 [deg]F. DOE surmises that this approach provided 
in appendix K of the relevant AHRI drafts represents industry consensus 
regarding a test to verify cut-out and cut-in temperatures for HPs. DOE 
has tentatively determined that this approach is appropriate while 
accounting for the capability limitations of certain test facilities. 
Therefore, DOE is proposing to require appendix K of the AHRI 210/240-
202X Draft to support enforcement associated with testing conducted in 
accordance with appendix M1, and to require appendix K of the AHRI 
1600-202X Draft to support enforcement associated with testing 
conducted in accordance with appendix M2. As further discussed in 
section III.J.1 of this document, DOE may verify certified cut-out and 
cut-in temperatures using the test methods in appendix K of the 
relevant AHRI drafts for the purposes of assessment and enforcement 
testing.
4. Low-Static Single-Split Blower-Coil System Definition and Testing 
Provisions
    Section 3.1.4.1.1 of appendix M1 defines the minimum ESP for ducted 
blower-coil systems in Table 4. For conventional blower-coil systems 
(i.e., all CAC/HPs that are not classified as ceiling-mount, wall-
mount, mobile home, low-static, mid-static, small-duct high-velocity 
(``SDHV''), or space-constrained), the minimum ESP is specified as 0.5 
in. wc. The definition for low-static blower-coil systems includes only 
multi-split and multi-head mini-split systems--it does not include 
single-split systems.
    In the January 2023 RFI, DOE explained that, during the previous 
rulemaking cycle that culminated in the October 2022 Final Rule, 
stakeholders requested that the low-static blower-coil system 
definition be expanded to include products, such as single-split 
systems, that cannot accommodate the 0.5 in. wc. necessary for testing. 
88 FR 4091, 4105-4106. However, in the October 2022 Final Rule, DOE did 
not revise the definition for low-static blower-coil systems, nor did 
it include any new test provisions to accommodate these system types. 
87 FR 64550, 64575-64576. DOE believed that revising the definition of 
low-static blower-coil systems would conflict with the intent of 
comments made by stakeholders when establishing appendix M1, and could 
potentially create an unfair competitive advantage for these system 
types by allowing more lenient testing conditions (and thus 
comparatively higher ratings) as compared to conventional centrally 
ducted systems tested at minimum ESPs exceeding 0.5 in. wc. (Id.)
    In the January 2023 RFI, DOE considered it appropriate to revisit 
the issue of extending the definition of low-static blower-coil systems 
to single-split systems, rather than grant test procedure waivers to 
allow such models to test using lower ESPs.\65\ 88 FR 4091, 4106. As 
such, DOE requested comment from stakeholders on whether the low-static 
blower-coil system definition should be extended to single-split 
systems, and if extended, how these low-static blower-

[[Page 24227]]

coil systems should be differentiated from conventional systems. (Id.)
---------------------------------------------------------------------------

    \65\ In the time since the January 2023 RFI, DOE has granted an 
interim waiver pending final determinations that allow testing for 
certain basic models of single-split low-static ducted blower-coil 
systems (which are incapable of meeting the conventional minimum ESP 
requirement of 0.5 in. wc. found in Table 4 of appendix M1). This 
interim waiver was granted to Samsung on June 5, 2023 (see 88 FR 
36558).
---------------------------------------------------------------------------

    In response, Daikin commented in support of developing a definition 
with stakeholders. (Daikin, No. 16 at p. 11) Similar to the existing 
``wall-mount'' and ``ceiling-mount'' blower-coil systems defined in 
appendix M1, Daikin commented that low-static blower-coil systems have 
physical and operational characteristics that could be defined such 
that it would not be possible for a common residential ducted blower-
coil to `cheat' the system and test at a lower ESP. (Id.) Daikin 
suggested this could be accomplished by defining physical dimensions 
(in a similar fashion to ``ceiling-mount'') as well as applying an 
appropriate maximum airflow rate per capacity (cfm per ton) at a 
relatively low ESP. (Id.)
    AHRI also commented in support of the addition of a definition for 
single-split low-static blower-coil systems, as low static single-zone 
\66\ units cannot accommodate the minimum 0.5 in. wc. ESP necessary to 
be tested using appendix M1. (AHRI No. 14 at pp. 14-15) AHRI proposed 
the following amended definition of a low-static blower-coil system 
(addition is in italic):
---------------------------------------------------------------------------

    \66\ The comments used the term ``single-zone'', which is 
addressed by the term ``single-split'' in appendix M1.
---------------------------------------------------------------------------

    Low static blower-coil system means (a) a ducted multi split or 
multi head mini split system for which all indoor units produce \67\ 
greater than 0.01 in. wc. and a maximum of 0.35 in. wc. external static 
pressure when operated at the cooling full load air volume rate not 
exceeding 400 cfm per rated ton of cooling, or (b) a ducted single zone 
mini split for which the indoor unit produces a maximum of 0.25 in. wc. 
external static pressure not exceeding 350 cfm/ton when operated at the 
highest possible air flow rate and has a rated heating or cooling 
capacity less than 24,500 Btu/h.
---------------------------------------------------------------------------

    \67\ The proposed alternate definition for ``Low-Static Blower-
Coil System'' in AHRI's response uses the language ``the indoor unit 
produce.'' (AHRI No. 14 at p. 14) DOE surmises that this is a 
typographical error and that AHRI meant to write ``all indoor units 
produce'' as is in appendix M1.
---------------------------------------------------------------------------

    Samsung agreed with AHRI's proposed definition and requested its 
adoption. (Samsung, No. 11 at p. 2)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, considered several issues raised in the January 2023 RFI, 
including the topic of extending the definition of low-static blower-
coil systems, when considering updated versions of industry test 
standards. The information provided in the aforementioned comments was 
discussed in detail in the development of the AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft, which, rather than amend the current low-
static blower-coil system definition, include a new definition specific 
for low-static single-split blower-coil systems as shown below.
    Low-static single-split blower-coil system means a ducted single-
split system air conditioner or heat pump for which all of the 
following apply:
    (1) The Outdoor Unit has a certified cooling capacity less than or 
equal to 24,000 Btu/h;
    (2) If the Outdoor Unit is a heat pump or a variable capacity air 
conditioner, it is separately certified with a blower-coil indoor unit 
tested with a minimum 0.5 in. wc. ESP, otherwise it is separately 
certified with a coil-only indoor unit; and
    (3) The Indoor Unit is marketed for and produces a maximum ESP less 
than 0.5 in. wc. when operated at the certified cooling full-load air 
volume rate not exceeding 400 scfm per rated ton of cooling.
    Both AHRI 210/240-202X Draft and AHRI 1600-202X Draft also include 
provisions instructing low-static single-split blower-coil systems to 
be tested at their certified airflow (not to exceed 400 scfm per rated 
ton of cooling capacity) at their maximum airflow setting. If the ESP 
achieved at the rated airflow is less than 0.1 in. wc., the provisions 
instruct adjustment of the airflow measurement apparatus fan to reduce 
airflow and increase ESP until a minimum of 0.1 in. wc. is achieved.
    DOE surmises that the new definition of low-static single-split 
blower-coil system and associated testing provisions provided in the 
relevant AHRI drafts represent industry consensus regarding the issue 
of expanding the low-static blower-coil system definition to include 
products, such as single-split systems, that cannot accommodate the 0.5 
in. wc. necessary for testing in appendix M1. DOE considers the new 
definition of low-static single-split blower-coil systems and the 
corresponding test requirements to be appropriate as they allow for 
testing of system combinations including indoor units that cannot meet 
the minimum ESP of 0.5 in. w.c. This approach would also require the 
outdoor unit to be rated when operating with a 0.5 in w.c. (or blower-
coil) indoor unit, thus ensuring that the outdoor units of low-static 
combinations do not gain an unfair advantage due to being allowed to 
test with an indoor unit at a lower ESP. Therefore, DOE is proposing to 
incorporate by reference the new definition of low-static single-split 
blower-coil system and the aforementioned testing provisions outlined 
in the AHRI 210/240-202X and AHRI 1600-202X Drafts, at appendix M1 and 
appendix M2, respectively.
    Should the new definition of low-static single-split blower-coil 
system and the associated testing provisions be adopted, DOE would 
terminate an interim waiver pending final determination, which allows 
testing for certain basic models of low-static single-split ducted 
blower-coil systems that are incapable of meeting the conventional 
minimum ESP requirement of 0.5 in. wc. found in Table 4 of appendix M1. 
The interim waiver was granted to Samsung on June 5, 2023 (see 88 FR 
36558). The interim waiver granted an alternate test procedure, which 
instructs the manufacturer to test their specific basic models at 0.1 
in. wc. ESP but to adjust the fan power \68\ to reflect operation at 
0.5 in. wc. ESP, consistent with the requirements of appendix M1. The 
alternate test procedure also instructed to adjust heating and cooling 
capacities \69\ to account for increased fan heat. The interim waiver 
was granted with the understanding that it was impossible to test the 
manufacturers' specific basic models according to the prescribed test 
procedures in appendix M1, DOE surmises that this alternate test 
procedure would no longer be necessary should appendix M1 be amended to 
enable testing of the manufacturers' specific basic models. Therefore, 
DOE is proposing to terminate the aforementioned waiver for Samsung, 
should the new definition of low-static single-split blower-coil system 
and associated testing provisions provided in the AHRI 210/240-202X and 
AHRI 1600-202X Drafts be adopted.
---------------------------------------------------------------------------

    \68\ In all sections of appendix M1 where total cooling 
capacity, total heating capacity, sensible cooling capacity, and 
electrical power consumption are calculated, the alternate test 
procedure requires the measured indoor fan power to be increased by 
87 watts per 1000 scfm. (see 88 FR 36558).
    \69\ The alternate test procedure requires that, for all tests, 
cooling capacity be decreased by the Btu/h equivalent of the fan 
power adjustment (i.e., 297 Btu/h per 1000 scfm); likewise, for all 
tests, the heating capacity be increased by the same Btu/h 
equivalent. (see 88 FR 36558).
---------------------------------------------------------------------------

5. Mandatory Constant Circulation Systems
    In the January 2023 RFI, DOE noted that there is a potential for 
increased use of indoor fan constant circulation in systems that employ 
new refrigerants to mitigate flammability risks. 88 FR 4091, 4102. 
Currently, nearly all CAC/HP products are designed with R-410A as the 
refrigerant. The EPA Significant New Alternatives Policy (``SNAP'') 
Program evaluates and regulates substitutes for ozone-depleting 
chemicals (such as CAC/HP refrigerants)

[[Page 24228]]

that are being phased out under the stratospheric ozone protection 
provisions of the Clean Air Act. (42 U.S.C. 7401 et seq.) \70\ Of 
interest to CAC/HPs, the EPA SNAP Program's list of viable substitutes 
\71\ includes a group of refrigerants classified as A2L refrigerants. 
A2L refrigerants receive high attention for their low GWP in addition 
to their minimal to zero ozone depletion potential. However, A2L 
refrigerants also face stricter safety requirements than most due to 
the flammability concerns associated with their ``2L'' ASHRAE safety 
classification.\72\
---------------------------------------------------------------------------

    \70\ Additional information regarding EPA's SNAP Program is 
available online at: www.epa.gov/ozone/snap/.
    \71\ List of EPA SNAP program-approved refrigerant substitutes 
is available at www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps.
    \72\ ASHRAE assigns safety classification to refrigerants based 
on toxicity and flammability data. The capital letter designates a 
toxicity class based on allowable exposure and the numeral denotes 
flammability. For toxicity, Class A denotes refrigerants of lower 
toxicity, and Class B denotes refrigerants of higher toxicity. For 
flammability, class 1 denotes refrigerants that do not propagate a 
flame when tested as per the standard; classes 2 and 2L denote 
refrigerants of lower flammability; and class 3 denotes highly 
flammable refrigerants (such as hydrocarbons).
---------------------------------------------------------------------------

    Considering A2L flammability concerns and the large push toward 
their increased use in design, UL published updated safety standards 
\73\ for electrical heat pumps, air-conditioners, and dehumidifiers 
that include the CAC/HP products at issue in this document. One safety 
risk these standards address is refrigerant leakage, which can be 
especially hazardous with A2Ls involved. In satisfaction of new UL 
safety requirements, manufacturers may need to adjust CAC/HP product 
design to include refrigerant leak detection systems that use sensors 
and control logic to detect a loss of pressure, activate the evaporator 
fan, and use circulated air to quickly disperse and dilute refrigerant 
in the event of a leakage. In the January 2023 RFI, DOE acknowledged 
that a subsequent need may exist for the constant circulation of 
refrigerant or circulation based on leak detection to accommodate these 
refrigerant leak detection and mitigation strategies in CAC/HP product 
design. 88 FR 4091, 4102. As such, DOE requested comment on whether UL 
safety requirements for A2L refrigerants will require some level of 
circulation on a continuous basis from a unit's indoor fan, or whether 
circulation to disperse refrigerant will only be required when sensors 
detect a leak. Id. DOE also expressed interest to know of any other 
techniques that manufacturers will use for dispersing the A2L 
refrigerant in the event of a refrigerant leak. Id.
---------------------------------------------------------------------------

    \73\ On November 1, 2019, UL published an updated 3rd edition of 
UL 60335-2-40 that includes safety requirements regarding the use 
A2L refrigerants in CAC/HP product design.
---------------------------------------------------------------------------

    In response, AHRI, Rheem, and Samsung all commented that constant 
circulation is a permitted option for A2L mitigation, but is not 
required. (AHRI, No. 14 at p. 12; Rheem, No. 12 at p. 6; Samsung, No. 
11 at p. 2) Daikin specifically noted that UL/CSA 60335-2-40 will only 
require circulation in the event of detection of a refrigerant leak, 
which is abnormal operation, and thus not a ``typical use cycle.'' 
(Daikin, No. 16 at p. 8) For alternative methods of A2L mitigation, 
Rheem pointed to ASHRAE Standard 15-2016, Safety Standard for 
Refrigeration Systems (``ASHRAE 15-2016''),\74\ which prescribes 
several methods to disperse/diffuse leaked refrigerant and allows 
selection of one or more methods to comply with safety standards. 
(Rheem, No. 12 at p. 6) Related to this topic, the CA IOUs commented 
that leak detection systems (which only activate the fan when required 
to disperse fugitive refrigerant) likely reduce a unit's energy 
consumption. (CA IOUs, No. 10 at p. 4)
---------------------------------------------------------------------------

    \74\ ASHRAE 15-2016 is available for purchase at 
www.techstreet.com/ashrae/standards/ashrae-15-2016-packaged-w-34-2016?product_id=1938420.
---------------------------------------------------------------------------

    While constant circulation may not be a required option, DOE notes 
that CAC/HPs may increasingly incorporate constant circulation systems 
in future design. As previously mentioned, AHRI and other stakeholders, 
including DOE, discussed several issues raised in the January 2023 RFI, 
including the topic of mandatory constant circulation systems, when 
considering updated versions of industry standards. The information 
provided in the aforementioned comments was discussed in detail in the 
development of AHRI 210/240-202X Draft and AHRI 1600-202X Draft, for 
which stakeholders agreed to include a new definition for ``mandatory 
constant circulation system,'' shown below.
    Mandatory constant circulation system means an air conditioner or 
heat pump that operates the indoor fan continuously when power is 
applied to the unit regardless of control settings.
    The updated industry standard drafts also include testing 
provisions for such systems, outlined in sections 5.1.1, 6.1.3.1.1, and 
6.1.3.2.1 as well as Table 7 of both AHRI 210/240-202X Draft and AHRI 
1600-202X Draft.\75\ These provisions require CAC/HPs meeting the 
mandatory constant circulation system definition not to use the default 
cooling and heating degradation coefficients, but rather to evaluate 
these degradation coefficients using the respective cyclic tests 
specified by Table 7, conducted in accordance with section E12 of 
appendix E of AHRI 210/240-202X Draft and AHRI 1600-202X Draft. DOE 
surmises that the new definition of mandatory constant circulation 
system and the aforementioned testing provisions provided in the 
relevant AHRI drafts represent industry consensus regarding 
representative testing of those CAC/HPs that may use constant 
circulation to meet the safety requirements for A2L refrigerants. DOE 
has tentatively determined that the definition and approach included in 
the draft industry standards provides a more representative measure of 
CAC/HP efficiency for units with mandatory constant circulation 
systems. Therefore, DOE is proposing to incorporate by reference the 
new definition of mandatory constant circulation system and the 
aforementioned testing provisions outlined in AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft, at appendix M1 and appendix M2, respectively.
---------------------------------------------------------------------------

    \75\ DOE notes that additional testing provisions for mandatory 
constant circulation systems are included in the AHRI 1600-202X 
Draft, which are separately discussed and proposed to be adopted in 
section III.F.1.e) of this NOPR.
---------------------------------------------------------------------------

6. Dual-Fuel Systems
    Heat pumps generally perform less efficiently at low ambient 
outdoor temperatures than they do at moderate ambient outdoor 
temperatures. In the January 2023 RFI, DOE expressed awareness of HPs 
that combine the operation of a conventional electric HP with a back-up 
heating source, such as a fuel-fired furnace or boiler. 88 FR 4091, 
4106. These are referred to as ``dual-fuel'' systems or hybrid heat 
pumps (``HHPs'') and provide an alternative to heat pumps specifically 
designed to perform in cold climates (i.e., cold climate heat pumps). 
Dual-fuel systems rely on heat pump operation at milder ambient 
temperatures, but switch to the back-up heating source at low ambient 
temperatures.
    Currently, the HSPF2 calculation at appendix M1 does not differ for 
a dual-fuel system and a HP that relies solely on vapor-compression or 
electric resistance auxiliary heating. However, in the January 2023 
RFI, DOE explained that this may not be representative of HHP field 
operation since the back-up heating source takes over for much of the 
coldest conditions when HP efficiency would be lower. 88 FR 4091, 4106. 
DOE also noted that, while the focus of test procedures for cold 
climate heat pumps has been on evaluation of performance at colder 
temperatures

[[Page 24229]]

(e.g., the optional 5 [deg]F test condition) to incentivize improved 
cold-temperature performance, incentivizing efficiency improvement for 
HHPs might more appropriately focus on warmer conditions, potentially 
temperatures warmer than 17 [deg]F. (Id.)
    In the January 2023 RFI, DOE requested information on the 
prevalence of HHP systems (including shipment numbers and shipment 
breakdown among single-stage, two-stage and variable-capacity) and the 
climates they are most used in. 88 FR 4091, 4106. Additionally, DOE 
requested information on how the controls for HHPs are generally set up 
to provide dual functionality--specifically, whether the furnace is 
just set at a higher stage, or whether there is a crossover temperature 
below which the HP isn't used; if so, the range of crossover 
temperatures and whether these systems have electric resistance 
auxiliary heaters. (Id.) DOE also requested feedback on whether it is 
more appropriate to adjust the HSPF2 to address actual operation of the 
heat pump or just to emphasize performance only in heat pump mode 
(i.e., when the back-up source is not operating). (Id.)
    In response, AHRI and Daikin both suggested that a proper 
definition and scope for HHP products should be developed if 
modifications to appendix M1 are made to address HHPs. (AHRI, No. 14 at 
pp. 3-4; Daikin, No. 16 at p. 11) Daikin commented that, while the most 
common HHPs, dual-fuel systems, have a temperature-based changeover 
where the heat pump stops operating and the gas furnace takes over, 
other HHPs may not always follow that model and may operate the gas 
furnace simultaneously with the heat pump under certain conditions. 
(Daikin, No. 16 at p. 11) Similarly, AHRI commented that, in most 
cases, accessory control tries to satisfy the set point temperature 
with the heat pump by itself, and, when unable to satisfy the set 
point, it will turn off the heat pump and turn on the furnace. (AHRI, 
No. 14 at p. 15) AHRI also noted that the heat pump lock-out 
temperature is typically set by the homeowner in the accessory control. 
(Id.)
    AHRI and Rheem both commented in support of a credit for dual-fuel 
systems in the HSPF2 calculation and noted that dual-fuel systems do 
not typically have electric resistance heaters. (AHRI, No. 14 at p. 15; 
Rheem, No. 12 at pp. 8-9) AHRI commented that dual-fuel heat pumps and 
HHPs offer a lower carbon heating solution that may pose other benefits 
as well. (AHRI, No. 14 at pp. 3-4) AHRI commented that electrification 
with fuel backup provides resiliency to the energy grid, particularly 
in locations where the grid is designed to accommodate summer peaking 
loads. (Id.) AHRI also commented that moving the thermal load from gas 
to electric results in a significant increase in peak electric demand 
in winter. (Id.)
    NYSERDA commented against including a credit for HHPs in the HSPF2 
calculation, noting that an HSPF2 credit adjustment would serve to 
encourage the use of switch-over controls that operate at a higher 
outdoor ambient temperature, which is at odds with maximizing heat pump 
performance and limits the decarbonization potential of heat pumps. 
(NYSERDA, No. 9 at p. 13) NYSERDA suggested a certification approach, 
which would incentivize an integrated control that optimally locks out 
auxiliary heating options (electric or gas) until it is no longer 
feasible for the HP to heat the space via only the vapor-compression 
cycle. (Id.) NYSERDA also recommended that DOE work to encourage lower 
temperature settings for the switchover device of a HHP whenever 
possible in the structure of the test procedure. (Id.) NYSERDA 
suggested that certification of cut-in and cut-out temperatures may 
help address some aspects of the issues presented in the January 2023 
RFI regarding HHPs. (Id.) However, NYSERDA also stated that it has 
found manufacturer's lowest catalogued temperature (``LCT'') in the 
engineering tables may be more important in practice than the cut-out 
and cut-in temperatures, which are often quite low. (Id.) While it 
acknowledged that cut-out and cut-in temperatures are useful for 
planning equipment applications and should be accounted for in bin 
model calculations of HSPF2, NYSERDA recommended using the LCT, the 
lowest temperature at which a manufacturer will stand behind its 
capacity and that DOE require the HSPF2 bin model always attribute a 
COP of 1 for any bin temperature below the LCT of a tested product. 
(Id.)
    NEEA recommended that DOE continue to explore HHP ratings that 
focus on maximizing time spent in electric heat pump mode before 
switching over to supplemental heating and suggested that on-board 
controls, which learn and adjust the crossover temperature based on 
performance, could earn a higher efficiency rating. (NEEA, No. 13 at p. 
8)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several issues raised in the January 2023 RFI, including 
the topic of dual-fuel systems, when considering updated versions of 
industry standards. The information provided in the aforementioned 
comments was discussed in detail in the development of AHRI 210/240-
202X Draft and AHRI 1600-202X Draft, which include a new definition for 
``dual-fuel heat pump,'' shown below.
    Dual-fuel heat pump means A central air conditioning heat pump 
consisting of (a) a rated combination of outdoor heat pump unit, of any 
type covered within this standard, (b) an indoor coil and (c) a furnace 
certified to DOE as an air mover and backup heat source.
    Additionally, AHRI 210/240-202X Draft and AHRI 1600-202X Draft 
introduce a new seasonal efficiency metric, Dual Fuel Utilization 
Efficiency (``DFUE''), meant to capture the heating efficiency of such 
dual-fuel heat pump systems. Calculation of DFUE is optional, requires 
no additional testing, and is outlined in appendix L of both AHRI 210/
240-202X Draft and AHRI 1600-202X Draft.
    DOE has tentatively determined that the definition and optional 
test approach included in the draft industry standards may provide a 
representative test approach for dual-fuel heat pump systems, but DOE 
is continuing to evaluate whether to include such provisions in its 
CAC/HP test procedures. Therefore, DOE is not proposing to incorporate 
by reference the new definition of dual-fuel heat pump and the optional 
seasonal efficiency metric, DFUE, outlined in the AHRI 210/240-202X and 
AHRI 1600-202X Drafts at this time.
    DOE notes that since dual-fuel heat pump systems are comprised of 
two covered products currently subject to energy conservations 
standards (i.e., a heat pump and a furnace), DOE would continue to 
require reporting of the relevant CAC/HP and consumer furnace heating 
metrics--HSPF2 and SHORE for CAC/HP, and AFUE for consumer furnaces--
but recognizes that representations of dual-fuel heat pump performance 
may be useful to consumers. DOE is not proposing provisions for dual-
fuel heat pumps, but would allow manufacturers to make optional 
representations of dual-fuel heat pump performance consistent with 
available industry test standards.
7. Provisions for Outdoor Units With No Match
    For split-system CAC/HPs, section 2.2.e of appendix M1 requires 
that an outdoor unit with no match (``OUWNM'') (i.e., outdoor units 
that are not distributed in commerce with any indoor units) be tested 
using a coil-only indoor unit with a single cooling air volume rate 
whose coil has round tubes of outer diameter no less than 0.375

[[Page 24230]]

inches, and normalized gross indoor fin surface (``NGIFS'', gross 
indoor fin surface divided by the measured cooling capacity) no greater 
than 1.0 square inch per British thermal unit per hour (sq. in./Btu/
hr). (10 CFR 429.16 (b)(2)(i) and appendix M1, section 2.2.e) These 
provisions were introduced in a final rule regarding CAC/HP test 
procedures published on June 8, 2016 (``June 2016 Final Rule''), to 
address outdoor-unit-only replacements of old R-22 outdoor units. 81 FR 
36992, 37008-37012. Effective January 1, 2010, EPA banned sales and 
distribution of CAC/HPs designed to use R-22, a hydrochlorofluorocarbon 
(``HCFC'') refrigerant, that causes ozone depletion. 74 FR 66450 (Dec. 
15, 2009). However, EPA continued to allow sale and distribution of 
``components'' of CAC/HP systems for repair purposes, such as outdoor 
units. Id. at 74 FR 66452. In the June 2016 Final Rule, DOE introduced 
the testing provisions for OUWNM to ensure that performance ratings for 
such installations would be representative of the replacement of 
outdoor units originally designed for R-22 and using the original 
indoor units. See 81 FR 36992, 37008-37011.
    While these OUWNM provisions were precipitated by EPA's ruling on 
R-22 units, DOE's intention was to apply them more broadly to any case 
where an outdoor unit is sold without an indoor unit. In the June 2016 
Final Rule, DOE noted that its test provisions were introduced to 
ensure that an unmatched outdoor unit would be compliant when tested 
with an indoor unit that is representative of indoor units in the field 
with which the outdoor unit could be paired. 81 FR 36992, 37009. DOE 
designed these requirements to meet the statutory requirement that the 
test procedure measure a representative average use cycle. Id. DOE 
noted that the indoor unit specifications represent lower-efficiency 
indoor units that would be paired with a given outdoor unit with no 
match. Id. DOE believed this approach was consistent with the 
requirement that the represented value for a basic model reflect the 
performance of the poorest-performing model that is part of the basic 
model. Id.
    In a final rule published on October 24, 2023 (``October 2023 EPA 
Final Rule''), EPA, pursuant to provisions of the American Innovation 
and Manufacturing Act, enacted on December 17, 2020 (42 U.S.C. 7675), 
restricted the installation of residential and light commercial systems 
that are designed for hydrofluorocarbon (``HFC'') refrigerants having a 
GWP greater than 700, starting January 1, 2025. 88 FR 73098. On 
December 26, 2023, EPA published an amendment to the October 2023 EPA 
Final Rule that extended the installation deadline to January 1, 2026 
as long as the components being installed were manufactured or imported 
prior to January 1, 2025. 88 FR 88825. Split-system CAC/HPs are 
included in the scope of residential and light commercial systems. As 
such, split-system CAC/HPs designed for use with R-410A and sold as a 
combination of an outdoor and indoor unit, would be banned for 
installation per the October 2023 EPA Final Rule. However, EPA allows 
consumers and businesses to replace, retrofit, and service components 
of existing systems that are over the GWP limits defined in the October 
2023 EPA Final Rule to ensure that new equipment with lower-GWP 
refrigerants is phased in only when all components of the older 
equipment reach the end of their functional life. 88 FR 73089, 73202. 
Hence, this provides an exemption for individual components of R-410A 
based split-system CAC/HP to be sold as replacements, similar to the 
component exemption adopted when R-22 was phased out. 74 FR 66450, 
66459-66460.
    As noted, DOE's OUWNM provisions apply for any outdoor units that 
are distributed in commerce without an indoor matching pair, regardless 
of the refrigerant the outdoor unit employs. Therefore, DOE clarifies 
that because of the October 2023 EPA Final Rule, any outdoor unit 
designed for R-410A or any banned refrigerant as per EPA regulations, 
when distributed in commerce without an indoor unit on or after January 
1, 2026, would be deemed an outdoor unit with no match, precisely 
because the October 2023 EPA Final Rule allows installation of such 
outdoor units only as no-match replacements. As EPA provided for after 
the R-22 ban, such outdoor units may be installed as a replacement 
component for an existing system but may not be sold with indoor units 
for installation as a complete split CAC/HP system.
    Although the current provisions for an outdoor unit with no match 
in appendix M1, 10 CFR 429.16, and 10 CFR 429.70 were finalized in the 
June 2016 Final Rule, DOE notes that appendix M1 currently does not 
explicitly define outdoor units with no match. While AHRI 210/240-202X 
Draft and AHRI 1600-202X Draft define outdoor units with no match, the 
definition applies explicitly only to R-22 replacement outdoor units 
and outdoor units using refrigerants with properties similar to R-22. 
This was because the initial establishment of the outdoor unit with no 
match provisions occurred in the wake of the R-22 ban. In light of the 
October 2023 EPA Final Rule, DOE is clarifying that similar treatment 
is applicable to replacement outdoor units designed for use with R-
410A, and any other refrigerants banned by EPA for full system 
installations. Because the definition of outdoor unit with no match in 
AHRI 210/240-202X Draft and AHRI 1600-202X Draft is specifically 
focused on R-22 outdoor units, DOE is not incorporating the definition 
by reference, and is instead proposing a clarifying definition that is 
consistent with DOE's intention in the June 2016 Final Rule. The 
proposed definition for appendix M1 is as follows:
    Outdoor Unit with No Match (OUWNM). An Outdoor Unit that is not 
distributed in commerce with any indoor units, and that meets any of 
the following criteria:
    (a) is designed for use with a refrigerant that makes the unit 
banned for installation when paired with an Indoor Unit as a system, 
according to EPA regulations in 40 CFR chapter I, subchapter C,
    (b) is designed for use with a refrigerant that has a 95 [deg]F 
midpoint saturation absolute pressure that is 18 percent of 
the 95 [deg]F saturation absolute pressure for R-22, or
    (c) is shipped without a specified refrigerant from the point of 
manufacture or is shipped such that more than two pounds of refrigerant 
are required to meet the charge per section 5.1.8 of AHRI 210/240-202X 
Draft. This shall not apply if either (a) the factory charge is equal 
to or greater than 70% of the outdoor unit internal volume times the 
liquid density of refrigerant at 95 [deg]F or (b) an A2L refrigerant is 
approved for use and listed in the certification report.
    The proposed definition of OUWNM for appendix M2 is the same as 
that for appendix M1, except that the reference in part (c) of the 
definition is to section 5.1.8 of AHRI 1600-202X Draft.
    DOE is proposing separate definitions in appendix M1 and appendix 
M2 because part of the definitions refer to sections of the relevant 
AHRI standards that are incorporated by reference (i.e., AHRI 210/240-
202X Draft for appendix M1, and AHRI 1600-202X Draft for appendix M2). 
Additionally, since the terms ``outdoor unit'' and ``indoor unit'' 
appear in the definition of outdoor unit with no match, DOE proposes to 
incorporate by reference the definitions for them from AHRI 210/240-
202X Draft and AHRI 1600-202X Draft.
    DOE tentatively concludes that the above definitions would further 
help clarify that the existing test procedure

[[Page 24231]]

and rating requirements for outdoor units with no match are applicable 
to R-410A based systems, and any other refrigerants banned by EPA 
regulations from January 1, 2026, as they have been previously, for R-
22 and any other ozone depleting refrigerants. The proposed definitions 
would apply to all types of outdoor units (i.e., heat pump, air 
conditioner, single-speed, two-speed, variable-speed, etc.). Outdoor 
units with no match would continue to be tested with an indoor coil 
having nominal tube diameter of 0.375 in and an NGIFS of 1.0 or less 
(as determined in section 5.1.6.3 of AHRI 210/240-202X Draft and AHRI 
1600-202X Draft). The determination of represented values, AEDM 
requirements, combinations selected for testing, and certification 
report requirements applicable to outdoor units with no match would 
remain the same as those specified in Table 1 to paragraph (a)(1), 
paragraph (c)(2), Table 2 to paragraph (b)(2)(i), and paragraph (e)(3), 
respectively in 10 CFR 429.16. Existing outdoor models currently 
distributed in commerce as part of a split system basic model that 
transition to a replacement outdoor unit only would need to be tested, 
rated, and recertified under the provisions in 10 CFR 429.16 for an 
outdoor unit with no match. The basic model number would need to change 
to reflect that the outdoor unit is no longer part of a combination as 
previously certified, but rather as an outdoor unit with no match, but 
the outdoor unit model could still be assigned the same individual 
model number.
8. Inlet and Outlet Duct Configurations
    In the June 2016 Final Rule, DOE made the following amendments 
regarding inlet and outlet duct configurations: clarified indoor unit 
air inlet geometry; ensured that the inlet plenum is not installed 
upstream of the airflow prevention device; and specified that the 
minimum lengths of inlet plenum, locations of static-pressure taps, and 
minimum cross-sectional dimensions are consistent with ANSI/ASHRAE 37-
2009. 81 FR 36992, 37037. DOE also clarified that when an inlet plenum 
is not used, then the length of straight duct upstream of the unit's 
inlet within the airflow prevention device must still adhere to the 
inlet plenum length requirements as illustrated in ANSI/ASHRAE 37-2009, 
Figures 7b, 7c, and 8. (Id.)
    In response, as discussed in the January 2017 Final Rule, 
stakeholders commented that DOE's clarification of inlet plenum may 
result in the overall height of unit setup exceeding the current height 
limit of many existing psychrometric rooms. 82 FR 1426, 1463. These 
stakeholders proposed that DOE consider allowing the approach included 
in ASHRAE's Research Project (``RP'') 1581, requesting DOE to approve 
the use of the 6'' skirt coupled with the 90[deg] square vane elbow, 
along with the appropriate outlet duct. Id.
    In the January 2023 RFI, DOE sought test data that shows testing 
done using reduced overall height of the unit setup (similar to that 
proposed in ASHRAE RP 1581) and compared against the baseline duct 
designs in ANSI/ASHRAE 37-2009 Figures 7b and 7c for blower-coil indoor 
units, and Figure 8 for coil-only indoor units. 88 FR 4091, 4105. DOE 
also requested information that could help inform the existing CAC/HP 
test procedures to allow testing in smaller environmental chambers, or 
to incorporate adjustments to the test setup that might reduce test 
burden. (Id.) DOE did not receive any such test data in responses to 
the January 2023 RFI. However, AHRI, Daikin, and Rheem all commented in 
support of including updates from the newest draft version of ASHRAE 
Standard 37 into the test procedure, which includes revisions 
investigated in RP 1581. (AHRI, No. 14 at p. 14; Daikin, No. 16 at p. 
10; Rheem, No. 12 at p. 8) Stakeholders also commented in support of 
including revisions investigated in RP 1743, which explored reduced-
length, alternative inlet duct configurations. (Id.)
    In May 2023, ASHRAE released for public review its first draft of a 
new version of ANSI/ASHRAE Standard 37 (``May 2023 ASHRAE 37 Draft''), 
which includes both RP 1581 and RP 1743 updates in section 6.4 of the 
standard. Subsequently, AHRI and other stakeholders, including DOE, 
worked to include these updates in AHRI 210/240-202X Draft and AHRI 
1600-202X Draft. Both appendix D of the AHRI 210/240-202X Draft and 
appendix D of the AHRI 1600-202X Draft contain May 2023 ASHRAE 37 Draft 
updates regarding inlet and outlet duct configurations, including the 
duct revisions investigated in RP 1581 and RP 1743 to accommodate 
smaller environmental chambers. DOE surmises that the inclusion of 
these May 2023 ASHRAE 37 Draft updates in appendix D of the relevant 
AHRI drafts represents industry consensus regarding inlet and outlet 
duct configurations. Additionally, DOE has tentatively determined that 
the updates included in the May 2023 ASHRAE 37 Draft are appropriate 
for CAC/HP testing while limiting testing burden. Consequently, DOE is 
proposing to incorporate by reference appendix D of AHRI 210/240-202X 
Draft at appendix M1 and to incorporate by reference appendix D of AHRI 
1600-202X Draft at appendix M2.
    DOE notes that AHRI 210/240-202X Draft and AHRI 1600-202X Draft 
reference the current version of ASHRAE Test Standard 37, ANSI/ASHRAE 
37-2009, because the May 2023 ASHRAE 37 Draft has not yet been 
finalized and published. DOE notes that it may choose to update its 
incorporation by reference to the final published version of the May 
2023 ASHRAE 37 Draft in a future rulemaking.
9. Heat Comfort Controllers
    A heat comfort controller enables a heat pump to regulate the 
operation of the electric resistance elements such that the air 
temperature leaving the indoor section does not fall below a specified 
temperature (see section 1.2 of appendix M1).
    Section 3.6.5 of appendix M1 includes test instructions for testing 
heat pumps having a heat comfort controller. Section 4.2.5 of appendix 
M1 includes additional steps for calculating the HSPF2 of heat pumps 
having a heat comfort controller, and covers the following system 
types:
    (1) heat pumps having a single-speed compressor and either a fixed-
speed indoor blower or a constant-air-volume-rate indoor blower 
installed;
    (2) single-speed coil-only system heat pumps;
    (3) heat pumps having a single-speed compressor and a variable-
speed, variable-air-volume-rate indoor blower;
    (4) heat pumps having a two-capacity compressor;
    Unlike the other aforementioned system types having a heat comfort 
controller, appendix M1 does not currently specify additional steps for 
calculating the HSPF2 of heat pumps having a heat comfort controller 
and having a variable-speed compressor. However, section 4.2.5.4 of 
appendix M1 is reserved for potential additional steps for calculating 
HSPF2 for this system type. This section was initially reserved in 
appendix M in the CAC/HP test procedure final rule published on October 
11, 2005. 70 FR 59122 (``October 2005 Final Rule'').
    In the January 2023 RFI, DOE requested information on the 
prevalence of HP systems that include heat comfort controllers. 88 FR 
4091, 4105. DOE also requested feedback on whether the heat comfort 
controller test approach in appendix M1 is utilized by manufacturers, 
and if yes, whether it needs to be updated. (Id.)
    In response, Rheem commented that heat comfort controllers are 
typically

[[Page 24232]]

found on premium CAC/HPs, many of which are variable-speed. (Rheem, No. 
12 at p. 8) However, Rheem also noted that since no additional steps 
for calculating the HSPF2 of heat pumps having a variable-speed 
compressor and a heat comfort controller are specified in the appendix 
M1 test procedure, there is limited utilization of the heat comfort 
controller test approach in appendix M1. (Id.) AHRI commented that it 
was unable to provide information regarding the current prevalence of 
heat comfort controllers due to time constraints but suggested that DOE 
require manufacturers notify consumers of the additional impacts to 
power consumption that come with the purchase of a heat comfort 
controller. (AHRI, No. 14 at p. 14)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, considered several issues raised in the January 2023 RFI, 
including the topic of heat comfort controller provisions, when 
considering updated versions of industry test standards. The 
information provided in the aforementioned comments was discussed in 
detail in the development of AHRI 210/240-202X Draft and AHRI 1600-202X 
Draft. Neither the AHRI 210/240-202X Draft nor the AHRI 1600-202X Draft 
include any changes to the heat comfort controller testing provisions 
for the following system types:
    (1) heat pumps having a single-speed compressor and either a fixed-
speed indoor blower or a constant-air-volume-rate indoor blower 
installed;
    (2) single-speed coil-only system heat pumps;
    (3) heat pumps having a single-speed compressor and a variable-
speed, variable-air-volume-rate indoor blower;
    (4) and heat pumps having a two-capacity compressor.
    However, AHRI 210/240-202X Draft and AHRI 1600-202X Draft now 
specify additional steps for calculating the HSPF2 and SHORE of heat 
pumps having a variable-capacity compressor and a heat comfort 
controller. These additional steps are similar to the additional steps 
for calculating the HSPF2 and SHORE of other system types having a heat 
comfort controller. DOE has tentatively determined that the inclusion 
of these additional steps for calculating HSPF2 and SHORE is 
appropriate for heat pumps having a variable-capacity compressor and a 
heat comfort controller because these provisions provide a 
representative measures of unit operation when installed with heat 
comfort controllers. Therefore, DOE is proposing to incorporate by 
reference the additional steps for calculating the HSPF2 of heat pumps 
having a variable-capacity compressor and a heat comfort controller 
outlined in section 11.2.2.5 of AHRI 210/240-202X Draft, at appendix 
M1. Likewise, DOE is proposing to incorporate by reference the 
additional steps for calculating the SHORE of heat pumps having a 
variable-capacity compressor and a heat comfort controller outlined in 
section 11.2.2.5 of AHRI 1600-202X Draft, at appendix M2.

G. Long-Term Changes in the CAC Test Procedure

    The following sections discuss issues that affect the CAC/HP test 
procedure in the long-term--i.e., they will be effective when new CAC/
HP standards are established denominated in terms of the metrics in 
appendix M2, SCORE, and SHORE. As previously explained, these long-term 
revisions would be implemented at appendix M2 via incorporation by 
reference of the relevant industry consensus test procedure, AHRI 1600-
202X Draft. DOE has reviewed the AHRI 1600-202X Draft in relevance to 
its proposed to incorporate the standard by reference at appendix M2, 
and has tentatively concluded that it satisfies the EPCA requirement 
that test procedures should not be unduly burdensome to conduct and 
should be representative of an average use cycle. (42 U.S.C. 
6293(b)(1)(A)) These long-term amendments in appendix M2 would alter 
the measured efficiency of CAC/HPs and would require representations in 
terms of new cooling and heating test metrics, SCORE and SHORE, 
respectively.
    Additionally, DOE clarifies that all proposals related to near-term 
issues discussed in section III.F of this document also apply to 
appendix M2.
1. Power Consumption of Auxiliary Components
    In the January 2023 RFI, discussed consideration of reflecting the 
power consumption of auxiliary components in the SEER2 and HSPF2 
efficiency metrics for CAC/HPs, at the recommendation of a comment made 
by the CA IOUs during the limited scope rulemaking that culminated in 
the October 2022 Final Rule. 88 FR 4091, 4102-4103. To help DOE further 
assess whether its test procedure adequately addresses crankcase heater 
(and other auxiliary component) energy use, DOE requested information 
and data from stakeholders regarding the power consumption of crankcase 
heaters and other auxiliary components in the January 2023 RFI. 88 FR 
4091, 4102-4103. The sections below address a range of topics 
associated with power consumption of auxiliary components.
    In addition, in the January 2023 RFI, DOE also requested 
information and available field data on any auxiliary components other 
than crankcase heaters that come equipped with CAC/HPs that use energy 
or affect systems energy use. 88 FR 4091, 4103. In response, Rheem 
commented that the off-mode power measurement per appendix M1 would 
account for leak sensor power consumption if leak sensors are required 
to be installed in the system during testing. (Rheem, No. 12 at p. 7) 
Additionally, Rheem commented that base pan heaters can only be 
installed by the factory, while other accessories, such as UV lights 
and electrostatic filters, are typically field installed. (Id.)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several topics included in the January 2023 RFI, 
including the topic of accounting for auxiliary components' power 
consumption, when considering updated versions of industry standards. 
The information provided by stakeholders in comments, summarized in the 
following subsections, was discussed in detail in the development of 
the AHRI 1600-202X Draft, which accounts for crankcase heater, base pan 
heater, and constant circulation fan energy consumption (as applicable) 
in the calculations of the new cooling and heating performance metrics, 
SCORE and SHORE. As part of the proceedings to develop the AHRI 1600-
202X Draft, manufacturers provided survey data regarding auxiliary 
components, their prevalence and their wattages, and the group 
conducted analysis to determine which auxiliary components not yet 
addressed in the current DOE test procedure should be considered.
(a) General Comments About Standby and Off Mode Power Consumption
    In response to the January 2023 RFI, the CA IOUs and NYSERDA both 
requested that DOE revisit the issue of accounting for the standby mode 
energy consumption of auxiliary components in appendix M1. (CA IOUs, 
No. 10 at p. 2; NYSERDA No. 9 at p. 7) NYSERDA requested elaboration on 
the justification for DOE's conclusion in the January 2023 RFI that 
standby mode energy consumption is addressed in the off-mode power 
consumption calculations in section 4.3 of appendix M1. (NYSERDA, No. 9 
at p. 7) NYSERDA commented that it seeks this clarification because DOE 
had previously summarized that standby mode is addressed in the part 
load SEER and HSPF metrics in both the August

[[Page 24233]]

2016 SNOPR \76\ and the June 2016 Final Rule.\77\ (Id.) Further, 
NYSERDA noted that, in the June 2016 Final Rule, DOE previously 
reviewed IEC Standard 62301 and determined that the procedures 
contained therein are not sufficient to properly measure off mode power 
for the unique characteristics of the components that contribute to 
off-mode power for CAC/HP products (i.e., the crankcase heaters).
---------------------------------------------------------------------------

    \76\ See 81 FR 58163, 58165. DOE noted, ``for CAC/HP, standby 
mode is incorporated into the SEER and HSPF metrics, while off mode 
power consumption is separately regulated. This SNOPR includes 
proposals relevant to the determination of both SEER and HSPF 
(including standby mode) and off mode power consumption.''
    \77\ See 81 FR 36992, 36994. DOE noted, ``for central air 
conditioners and heat pumps, standby mode is incorporated into the 
SEER metric, while off mode power consumption is separately 
regulated. This final rule includes modifications relevant to the 
determination of both SEER (including standby mode) and off mode 
power consumption.''
---------------------------------------------------------------------------

    Daikin commented that, in line with the general principle floated 
in the recent commercial unitary air conditioner (``CUAC'') and 
commercial unitary heat pump (``CUHP'') (collectively, ``CUAC/HP'') 
rulemaking,\78\ a seasonal metric should measure all capacity delivered 
divided by all power consumed; and there should be a single seasonal 
metric for cooling and a single seasonal metric for heating to 
encompass all energy consumption, eliminating secondary metrics such as 
energy efficiency ratio (``EER'') and off-mode power 
(``PW,OFF''). (Daikin, No. 16 at p. 7)
---------------------------------------------------------------------------

    \78\ See 88 FR 56392 for the most recent NOPR regarding CUAC/HPs 
published on August 17, 2023.
---------------------------------------------------------------------------

    NYSERDA commented that, while further consideration to off-mode 
energy consumption may not be strictly necessary for CAC/HPs (because 
appendix M1 already includes off-mode provisions), it urges DOE to 
consider a more comprehensive approach to standby mode. (NYSERDA, No. 9 
at pp. 7-8) NYSERDA recommended the inclusion of crankcase heater power 
in seasonal efficiency ratings that include shoulder periods. (Id.)
    DOE notes that, while IEC Standard 62301 and EPCA (see 42 U.S.C. 
(gg)(1)) define both standby mode and off mode for energy-using 
products such as air-conditioners and heat pumps, DOE defined only 
``off mode'' in its test procedures for CAC/HPs. ``Off mode power 
consumption'' is defined as the power consumption when the unit is 
connected to its main power source but is neither providing cooling nor 
heating to the building it serves. Thus, off-mode power consumption can 
be considered to include power consumption associated with any system 
components (e.g., crankcase heaters, fans, controls, base pan heaters, 
etc.) during any times that neither cooling nor heating are being 
provided, including shoulder season, heating season for a cooling-only 
air-conditioner, and times when the compressor is not operating (e.g., 
during an off-cycle during a cooling or heating season). While some of 
the system modes during these times could be seen as complying with the 
EPCA definition for standby mode, the appendix M1 test procedure uses 
the single term ``off mode'' to refer to all of these modes. Discussion 
about these modes for central air conditioner and heat pumps has often 
used both the terms ``standby'' and ``off,'' even though they are both, 
per appendix M1, defined as ``off mode.''
    Thus, in response to NYSERDA, DOE clarifies that standby power 
consumption (per appendix M1, ``off-mode'' power consumption) is indeed 
incorporated to an extent in the SEER2 and HSPF2 metrics, and that some 
of the off-mode power consumption is separately regulated by the off-
mode power metric, PW,OFF. As noted in a footnote of the 
January 2023 RFI, some energy use associated with crankcase heaters may 
be measured in the cyclic cooling test (for non-temperature dependent 
crankcase heaters) and cyclic heating test in appendix M1. 88 FR 4091, 
4102. The energy use of auxiliary components such as control boards, 
reversing valves, and electronic expansion valves would also be 
captured during the off cycle during cyclic testing. Hence, some off 
mode energy consumption is captured in the SEER2 and HSPF2 metrics. 
However, DOE acknowledges that not all off mode energy consumption is 
captured by the SEER2 and HSPF2 metrics because the calculations for 
these metrics do not account for all the hours in a year. Specifically, 
shoulder-season energy use of auxiliary components is not captured 
consistent with the number of hours that such components may be 
energized (e.g., for hours representing outdoor temperatures between 
54.5 [deg]F and 64.5 [deg]F). In response, as detailed in section 
III.F.1.e of this NOPR, DOE is proposing to incorporate by reference 
the AHRI 1600-202X Draft at appendix M2, which addresses additional 
standby and off-mode power consumption in the SCORE and SHORE metrics, 
including base pan heaters and indoor fans that are required to operate 
in constant circulation mode to address A2L refrigerant requirements. 
The test standard also provides a more comprehensive way to include all 
significant standby and off-mode energy use, including that of 
crankcase heaters, in the efficiency metrics, in a way that is similar 
to the approach described in recommendation 13 of the 2022 ASRAC CUAC 
and CUHP WG TP term sheet.\79\ Specifically, the SCORE and SHORE 
efficiency metrics both represent conditioning provided during the 
cooling or heating season, respectively, divided by relevant energy use 
associated with all components that contribute significantly to energy 
use.
---------------------------------------------------------------------------

    \79\ Recommendation 13 of the 2022 ASRAC CUAC and CUHP WG TP 
term sheet requires manufacturers to certify crank case heat watts 
for each heater in the certified CUAC/CUHP, where each of the 
certified wattages must be within 10% of the maximum heater wattage 
determined according to the CUAC/CUHP TP at the tested nameplate 
voltage
---------------------------------------------------------------------------

(b) Adjustment of Off Mode Power Consumption for Number of Compressors, 
System Capacity, and Variable Speed and Weighting of Off-Mode Test 
Power Measurements
    In response to the January 2023 RFI, the CA IOUs requested that DOE 
consider removing the adjustment factors for off-mode power 
consumption, and, instead, change the requirement for off-mode power 
consumption to a maximum allowed power consumption table based on 
system capacity, number of compressors, and stages. (CA IOUs, No. 10 at 
pp. 2-3)
    The CA IOUs also recommended that the P1 and 
P2 components of PW,OFF be weighted based on the 
population-weighted number of hours where the outdoor temperature is 
less than 70 \0\F, instead of simply averaged. (CA IOUs, No. 10 at p. 
3) Aligning with the data presented in Table 2 of their response,\80\ 
the CA IOUs stated that this approach would change the weighting from 
50-percent P1 and 50-percent P2 (a simple 
average) to 30-percent P1 and 70-percent P2. 
(Id.)
---------------------------------------------------------------------------

    \80\ Table 2 of the CA IOUs response to the January 2023 RFI 
includes data taken from ASHRAE Standard 169-2021, Climatic Data for 
Building Design Standard, and the United States Census Bureau, with 
additional analysis performed by CA IOUs. (CA IOUs, No. 10 at p. 3)
---------------------------------------------------------------------------

    DOE notes that the modified approach for off-mode energy 
consumption in AHRI 1600-202X Draft, which DOE proposes to incorporate 
by reference, addresses both of these points, as discussed in section 
III.G.1.e of this NOPR.
(c) Crankcase Heaters
    Regarding crankcase heaters, in the January 2023 RFI, DOE requested 
information as to what percentage of units on the market (split 
separately

[[Page 24234]]

between air conditioners and heat pumps) are shipped from the factory 
with crankcase heaters; what percentage have crankcase heaters 
installed in the field (e.g., by contractors); and the percentage 
breakdown of controls used with units (both factory- and field-
installed)--by those that are energized at full power during the 
compressor off cycle, those that also have an ambient thermostat to 
prevent use when temperature is high, and those that are self-
regulating. 88 FR 4091, 4102-4103.
    In response, Daikin commented that the majority (shipment volume) 
of air conditioners do not have crankcase heaters, while nearly all 
heat pumps do have crankcase heaters. (Daikin, No. 16 at p. 8) Daikin 
stated that the use of crankcase heaters typically correlates with 
higher refrigerant charge quantities, and that, as a result, higher 
efficiency AC units, with higher refrigerant charge quantities, are 
more likely to have crankcase heaters than lower efficiency ones. (Id.) 
Further, Daikin commented that long-line set applications, such as 
multi-story apartment buildings, would be the most common applications 
of field-installed crankcase heaters--again due primarily to the 
additional refrigerant charge required in those applications. (Id.) 
Rheem estimated that less than 10 percent of factory units have 
crankcase heaters and commented that it believes field installations 
for crankcase heaters to be infrequent, but depends on the length of 
refrigerant line set for a given installation. (Rheem, No. 12 at pp. 6-
7)
    The CA IOUs, NEEA, and NYSERDA all recommended that DOE account for 
crankcase heater energy use by aligning with recommendation 13 of the 
2022 ASRAC CUAC and CUHP WG TP term sheet. (CA IOUs, No. 10 at p. 2; 
NEEA, No. 13 at p. 8; NYSERDA, No. 9 at pp. 10-12) Recommendation 13 of 
the 2022 ASRAC CUAC and CUHP WG TP term sheet suggests that DOE require 
manufacturers to certify crankcase heater wattage for each heater, and 
that each wattage certified be within 10 percent of the maximum wattage 
for that heater as determined in accordance with the test procedure at 
the tested nameplate voltage. Further, equipment that does not employ 
crankcase heating shall certify a value of zero.
    In response, DOE notes that accounting for crankcase heater energy 
use for CUAC/CUHPs differs from such accounting for CAC/HPs in two 
fundamental ways that make recommendation 13 of the CUAC/CUHP WG TP 
term sheet inappropriate for this test procedure. First, CUACs and 
CUHPs generally have more than one compressor, often three or four 
compressors, whereas nearly every CAC/HP has just one. Second, control 
of crankcase heaters in CUACs and CUHPs, as discussed in the WG 
discussions is much more straightforward than for CAC/HPs. 
Specifically, the crankcase heaters for CUACs and CUHPs are nearly 
exclusively controlled to be on when the compressor is off and off when 
the compressor is on, with no consideration of shutoff for warm 
temperatures, and no significant use of self-regulating heater designs. 
Thus, it is both possible and necessary to conduct testing to 
understand CAC/HP crankcase energy use--possible because of the single 
compressor (and crankcase heater), and necessary to understand the 
control. The certification of crankcase heater wattages, as was adopted 
CUACs and CUHPs to avoid the additional test burden to testing multiple 
heaters, would not reduce the need for testing in the case of CAC/HPs. 
Although this rulemaking does not specifically address certification, 
DOE may consider certification requirements for crankcase heater 
wattages in a separate rulemaking.
    Similar to ratings in SPE07, NYSERDA suggested that crankcase 
heaters and drain pan heaters (if present) could be included in the 
test procedure as separate tests and appropriately attributed to 
efficiency metrics depending on their specific control strategy. 
(NYSERDA, No. 9 at p. 8) NYSERDA suggested this approach, commenting it 
could be employed in the DOE procedure without causing a wholesale 
change in operating test procedures. (Id.)
    DOE responds that the test procedure as included in AHRI 1600-202X 
Draft, which DOE proposes to incorporate by reference in the CAC/HP 
test procedure, addresses crankcase heaters (and base pan heaters if 
present) in a way that is consistent with the approach recommended by 
NYSERDA. The information provided in the aforementioned comments was 
discussed in detail in the development of the AHRI 1600-202X Draft, 
which accounts for crankcase heater power consumption in the new 
cooling and heating metrics, SCORE and SHORE. The AHRI 1600-202X Draft 
provisions that account for crankcase heater power consumption are 
detailed in section III.G.1.e of this NOPR.
    In the August 2016 SNOPR, DOE revised the off-mode test procedure 
by imposing time delays to allow self-regulating crankcase heaters to 
approach equilibrium. 81 FR 58163, 58173-58174. Specifically, DOE 
proposed a 4-hour time delay for units without compressor sound 
blankets and an 8-hour time delay for units with compressor sound 
blankets. (Id.) DOE proposed these time delays based on testing of a 5-
ton residential condensing unit. (Id.) In response to stakeholder 
comments regarding the aforementioned time delays, DOE decided in the 
January 2017 Final Rule to adopt the proposed time delays for 
measurements of off-mode power in appendix M1 for units with self-
regulating crankcase heaters or heater systems in which the crankcase 
heater control is affected by the heater's heat. 82 FR 1426, 1438. 
Nevertheless, in the January 2023 RFI, DOE acknowledged that with more 
test procedure development time, an approach could potentially be 
developed that would allow for accurate projections of self-regulating 
crankcase heater energy use to be determined in reduced time and 
requested comment on this possibility. 88 FR 4091, 4103.
    In the January 2023 RFI, DOE requested test data that would 
indicate if and how the 4-hour time delay (for compressors without 
sound blankets) and 8-hour time delay (for compressors with sound 
blankets) may be reduced for units with self-regulating crankcase 
heaters without compromising the accuracy of the off-mode power 
consumption measurement. 88 FR 4091, 4103. In response, Rheem commented 
that more study would be needed to understand the effects of delay 
reductions on both the accuracy of off-mode power consumption as well 
as on reliability of the compressor and crankcase heater. (Rheem, No. 
12 at p. 7) No other stakeholders commented on this issue. Hence, DOE 
is proposing no changes to the 4- or 8-hour test duration for self-
regulating crankcase heaters.
(d) Shoulder-Season Fan Power Consumption
    In the January 2023 RFI, DOE requested comments on fan-only 
operation during the shoulder season, constant circulation controls, 
current use of constant circulation among CAC/HP products, the 
potential of increased future fan use (considering the transition to 
low-GWP refrigerants), and whether a need exists to account for 
constant circulation mode in the measurement of SEER2 and HSPF2. 88 FR 
4091, 4101-4102. Additionally, DOE requested information on the typical 
fan power for constant circulation mode for blower-coil systems (or as 
a fraction of cooling or heating fan power), the percentage of people 
that use this mode and the associated hours per year on average the 
system would be in this mode, whether constant circulation mode is a 
default or user configurable

[[Page 24235]]

setting for these systems, whether the measurement of SEER2 and/or 
HSPF2 should take into consideration that a certain fraction of systems 
will use constant circulation mode rather than turn off the fan during 
the compressor off mode, and whether manufacturers could use constant 
circulation as part of their mitigation strategy for refrigerant 
leakage. (Id.)
    In response, AHRI, Daikin, and Samsung all commented that constant 
circulation mode is a user configurable setting; and Samsung elaborated 
that the default constant circulation mode setting for its products is 
``OFF.'' (AHRI, No. 14 at p. 11; Daikin, No. 16 at p. 7; Samsung, No. 
11 at p. 2) AHRI and Daikin commented that only a small portion of 
consumers use constant circulation mode, citing the January 2023 RFI's 
reference to DOE's furnace fan efficiency rulemaking that suggests it 
is only used by 9 percent of consumers.\81\ (AHRI, No. 14 at p. 11; 
Daikin, No. 16 at p. 7)
---------------------------------------------------------------------------

    \81\ See 77 FR 28674, 28682-28683 for the survey data used to 
estimate this value in a furnace fan NOPR published on May 15, 2012.
---------------------------------------------------------------------------

    AHRI and Rheem commented that it is impossible to predict how 
widespread the use of constant circulation will be as a potential 
mitigation for A2L refrigerants. (AHRI, No. 14 at p. 11; Rheem No. 12 
at pp. 5-6) Rheem explained that, for systems containing group A2L 
refrigerants and utilizing continuous circulation airflow as a 
mitigation strategy, the required circulation airflow rate is defined 
in safety standards as a function of system charge and refrigerant 
lower flammability limit. (Rheem No. 12 at pp. 5-6) Rheem noted that 
airflow rates (and associated blower motor power consumption) in 
continuous airflow mode for systems designed today--which contain group 
A1 refrigerants--are unlikely to be the same as the minimum circulation 
airflow rate defined in safety standards, and that, therefore, using 
data from systems sold today is unlikely to be representative of 
systems sold in the future. (Id.) Rheem asserted that it is difficult 
to predict whether manufacturers will redesign blower-coil systems to 
match the minimum circulation airflow as calculated from equations 
prescribed by safety standards, or choose an existing airflow tap that 
gives an airflow rate greater than the required minimum when utilizing 
continuous circulation airflow as the mitigation action. (Id.)
    AHRI, Daikin, Rheem, and Samsung all were opposed to accounting for 
constant circulation mode in the test procedure and efficiency metrics 
for CAC/HPs, reasoning that, as described earlier, constant circulation 
airflow is utilized by only a small portion of all consumers and only 
occurs due to consumer selection. (AHRI, No. 14 at p. 12; Daikin, No. 
16 at pp. 7-8; Rheem, No. 12 at p. 6; Samsung, No. 11 at p. 2) 
Conversely, the CA IOUs and NYSERDA both recommended that DOE consider 
addressing the energy consumption of fans in constant circulation mode 
for all products in either the CAC/HP test procedure or furnace fan 
test procedure. (CA IOUs, No. 10 at p. 4; NYSERDA, No. 9 at p. 12) To 
back its position, NYSERDA pointed to its evaluation of heat pump 
programs that found fan energy is not adequately accounted for in 
reported data and can be widely variable. (NYSERDA, No. 9 at p. 12) 
Further, NYSERDA suggested that, when a manufacturer's standard 
equipment settings include a continuous or intermittent fan-on mode of 
operation (for example, to sample the air temperature) as the default, 
constant fan-on energy should be incorporated in the standby power 
measurement, along with the bin-hour attribution of standby to SEER2 
and HSPF2. (Id.)
    As previously mentioned, AHRI and stakeholders, including DOE, 
considered several topics raised in the January 2023 RFI, including 
shoulder-season fan power consumption, when considering updated 
versions of industry standards. The information provided in the 
aforementioned comments was discussed in detail in the development of 
AHRI 1600-202X Draft. The draft industry test standards do not include 
constant circulation fan energy consumption in the efficiency metrics 
due to the use of this mode by the minority of consumers which are 
understood to select it, for systems for which the mode is user-
selectable. However, for systems that require constant circulation at 
all times as a refrigerant leakage mitigation strategy, the constant 
circulation is considered as part of the standby and off mode energy 
use in the SCORE and SHORE metrics of AHRI 1600-202X Draft, and also in 
the cyclic degradation coefficient for both test standards. The AHRI 
1600-202X Draft provisions that account for shoulder-season fan power 
consumption are detailed in section III.F.1.e of this NOPR.
(e) Accounting for Auxiliary Components' Power Consumption
    The information provided by stakeholders in comments, summarized in 
the previous subsections, was discussed in detail in the development of 
AHRI 1600-202X Draft, which accounts for crankcase heater, base pan 
heater, and constant circulation fan energy consumption (as applicable) 
in the calculations of the new cooling and heating performance metrics, 
SCORE and SHORE. AHRI 1600-202X Draft introduces SCORE and SHORE as 
replacements for the current cooling and heating performance metrics, 
SEER2 and HSPF2, used to determine the measured efficiency of CAC/HPs. 
Unlike SEER2 and HSPF2, which DOE previously noted are only seasonal 
descriptors, these new metrics account for the standby and off-mode 
power consumption of auxiliary components, including those components 
discussed previously (i.e., crankcase heaters and indoor fans utilizing 
constant-circulation) for both SCORE and SHORE; and, additionally, base 
pan heaters for SHORE.
    AHRI 1600-202X Draft includes a new quantity, Es,c 
(measured in watt-hours), added to the denominator of the calculation 
for SCORE, meant to represent all auxiliary component energy usage 
during cooling mode (i.e., during both cooling conditioning hours and 
cooling-season shoulder-season hours, as applicable). Outlined in 
section 11.2.1.4 of AHRI 1600-202X Draft, Es,c is the 
summation of each component's average power multiplied by each 
component's number of hours of standby operation during cooling mode, 
as follows:

Es,c = (P1 * N1 + P2 * N2) 
+ (PCCF * NCCF)

    Table 14 of AHRI 1600-202X Draft outlines instructions for 
determining each component's number of standby power operating hours in 
cooling mode (N1 and N2 for the crankcase heater 
and NCCF for the constant circulation fan). In the case of 
crankcase heaters, calculations for N1 and N2 
depend on the type of crankcase heater controls used by the CAC/HP 
system.
    AHRI 1600-202X Draft also includes a new quantity, Es,h 
(also measured in watt-hours), added to the denominator of the 
calculation for SHORE, that is meant to represent all auxiliary 
component energy usage during heating mode (i.e., during both heating 
conditioning hours and heating-season shoulder-season hours, as 
applicable). Outlined in section 11.2.1.4 of AHRI 1600-202X Draft, 
Es,c is the summation of each component's average power 
multiplied by each component's number of hours of standby operation 
during heating mode, as follows:

Es,h = (P1 * N1 + P2 * N2) 
+ (PBPH * NBPH)

    Table 16 of AHRI 1600-202X Draft outlines instructions for 
determining each component's number of standby power operating hours in 
heating mode (N1 and N2 for the crankcase heater,

[[Page 24236]]

NCCF for the constant circulation fan, and NBPH 
for the base pan heater). In the case of crankcase heaters, 
calculations for N1 and N2 depend on the type of 
crankcase heater controls used by the CAC/HP system. Similarly, the 
calculation of NBPH depends on the type of base pan heater 
controls used by the system.
    Appendix H of AHRI 1600-202X Draft outlines instructions for 
determining the average power (P1 and P2 for the 
crankcase heater, PCCF for the constant circulation fan, and 
PBPH for the base pan heater) of all auxiliary components 
considered in the calculations of either Es,c or 
Es,h.
    DOE surmises that the respective inclusions of Es,c and 
Es,h into the calculations of the new cooling and heating 
performance metrics, SCORE and SHORE, represent industry consensus 
regarding whether to reflect the power consumption of auxiliary 
components in the efficiency metrics for CAC/HPs. DOE has tentatively 
determined that inclusion of the energy consumed by auxiliary 
components in the efficiency metrics for CAC/HPs would result in more 
representative measures of efficiency. Therefore, DOE is proposing to 
incorporate by reference the new cooling and heating performance 
metrics, SCORE and SHORE, as included in AHRI 1600-202X Draft, and the 
associated provisions regarding the standby and off-mode power 
consumption of auxiliary components, in appendix M2.
2. Impact of Defrost on Performance
    When operating in moderate to low outdoor ambient temperatures, the 
outdoor coil surface temperature of a HP is sufficiently low to freeze 
over, and frost collects on the coil. To combat the collection of ice 
on the outdoor coil, a HP must undergo a defrost cycle, where the HP 
temporarily switches to cooling mode operation. Temporarily switching 
to cooling mode operation enables a HP to transfer heat from the indoor 
coil to the outdoor coil, thus providing the heat needed to warm the 
coil and melt the frost. During defrost, different control strategies 
are applied to maintain comfort level inside the house. For example, 
the indoor fan may or may not be operated during defrost, and (if the 
indoor fan is operated) the auxiliary resistance heater may or may not 
be energized to warm the indoor air while the system is temporarily in 
defrost mode. Defrost initiation can be based on time (clock time or 
time of compressor operation), or the need for defrost can be 
determined based on temperature and pressure or other measurements that 
provide an indication of the need for defrost.\82\ Currently, appendix 
M1 defines a demand-defrost control system as a system that defrosts 
the HP outdoor coil only when measuring a predetermined degradation of 
performance. When frequent defrost occurrences are not needed (e.g., 
when there is insufficient moisture in the outdoor air to build up a 
significant frost layer on the outdoor coil), demand defrost can save 
energy by delaying defrost initiation. Defrost cycles are terminated 
when there is indication that defrost has been long enough for frost to 
be eliminated from the coil (e.g., when a coil temperature sensor 
indicates the coil is well above 32[deg]F).
---------------------------------------------------------------------------

    \82\ Some examples of parameters monitored for demand-defrost 
control systems are coil to air differential temperature, coil 
differential air pressure, outdoor fan power or current, optical 
sensors. Note that systems that vary defrost intervals according to 
outdoor dry-bulb temperature are not demand-defrost systems.
---------------------------------------------------------------------------

(a) Demand Defrost Credit
    For CAC/HPs equipped with demand defrost, appendix M1 includes a 
term called the demand defrost credit (``Fdef'') in the 
HSPF2 calculation to provide nominal credit for HPs with a demand-
defrost control system,\83\ reflecting the relative improvement in 
heating mode efficiency due to use of demand defrost rather than 
defrosts with fixed periodicity. The credit equation has remained 
unchanged in its current form in the test procedure since at least 
January 22, 2001, when DOE published a NOPR regarding CAC/HP test 
procedures. 66 FR 6767. In the January 2023 RFI, based on test results 
of several CAC/HPs in various programs, DOE noted that it is aware of a 
range of defrost operation sequences and a range of approaches to 
defrost initiation for demand defrost. 88 FR 4091, 4104. Based on these 
observations, DOE acknowledged that the demand defrost credit may no 
longer accurately reflect the benefits of demand defrost. Id.
---------------------------------------------------------------------------

    \83\ The demand-defrost credit, first introduced in a March 14, 
1988 rulemaking (53 FR 8304, 8319), is calculated by the following 
equation in section 3.9.2 of appendix M1: Fdef = 1 + 0.03[1-
[Delta][tau]def-1.5/[Delta][tau]max-1.5], where [Delta][tau]def = 
time between defrost terminations (in hours) or 1.5, whichever is 
greater. [Delta][tau]def is assigned a value of 6 if this limit is 
reached during a frost accumulation test and the heat pump has not 
completed a defrost cycle, and [Delta][tau]max = maximum time 
between defrosts as allowed by the controls (in hours) or 12, 
whichever is less, as provided in the certification report.
---------------------------------------------------------------------------

    In the January 2023 RFI, DOE sought information on the operation of 
demand-defrost control systems, specifically any information that would 
indicate whether the demand-defrost credit outlined in the calculation 
in section 3.9.2 of appendix M1 is representative of the improvement in 
seasonal heating efficiency in field operation. 88 FR 4091, 4104. DOE 
also requested comment on whether any specific change in the credit 
equation could improve its accuracy. Id.
    In response, AHRI, Daikin, and Rheem all commented that they would 
support an effort by stakeholders to establish a new demand defrost 
credit that incentivizes advanced defrost strategies and more 
accurately reflects the current state of defrost technology. (AHRI, No. 
14 at p. 13; Daikin, No. 16 at pp. 9-10; Rheem, No. 12 at pp. 7-8) 
Similarly, the Joint Advocates encouraged DOE to provide a more 
sophisticated calculation of the credit, if a revised test procedure 
maintains the treatment of defrost separately (as a separate test). 
(Joint Advocates, No. 8 at pp. 3-4)
    Daikin and the Joint Advocates commented that the current defrost 
credit is overly dependent on timing between defrosts and suggested 
that the current defrost credit calculation methodology should be 
modified to recognize, differentiate, and incentivize other advanced 
defrost strategies and their controls. (Daikin, No. 16 at pp. 9-10; 
Joint Advocates, No. 8 at pp. 3-4) Daikin specifically pointed out that 
appendix M1 currently only recognizes a 3-percent maximum credit during 
defrost for a defrost cycle of 91 minutes (even though modern equipment 
in some cases can go significantly longer than 91 minutes before 
performance degradation necessitates a defrost) and suggested that the 
current procedure be modified so that it no longer incentivizes the 91-
minute cycle regardless of whether equipment needs to defrost at that 
time. (Daikin, No. 16 at pp. 9-10) The Joint Advocates noted that, in 
the definition of demand defrost control system, DOE acknowledges the 
different types of controls including parameters that vary with the 
amount of frost accumulated on the outdoor coil (e.g., coil to air 
differential temperature, coil differential air pressure, outdoor fan 
power or current, or optical sensors) and suggested that these 
parameters be included in the calculation methodology of a new demand 
defrost credit. (Joint Advocates, No. 8 at pp. 3-4)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several issues raised in the January 2023 RFI, including 
the topic of the demand defrost credit, when considering updated 
versions of industry standards. The information provided in the 
aforementioned comments was discussed in detail in the development of 
AHRI 1600-202X Draft, which includes a simplified demand

[[Page 24237]]

defrost credit that uniformly applies a 3% increase to the SHORE rating 
for all HPs. As such, Fdef no longer depends on the amount 
of time between defrost initiations (e.g., Tdef and 
Tmax in appendix M1), and can be either one of two values: 
1.03 (for systems equipped with a demand defrost control system) or 1 
(for all other systems). DOE surmises that the simplified demand 
defrost credit in AHRI 1600-202X Draft represents industry consensus 
regarding improvements to the accuracy of the credit, incentives for 
more efficient defrost control strategies, and more accurate 
representations of modern defrost control technologies in the test 
procedure. DOE has tentatively determined that a simplified demand 
defrost credit would disincentivize unnecessary early defrosts (90 
minutes after the termination of the prior defrost cycle), accurately 
represent defrost energy use while limiting test burden, and 
consequently allow for more advanced and efficient defrost control 
strategies. Therefore, DOE is proposing to incorporate by reference the 
simplified demand defrost credit in AHRI 1600-202X Draft, at appendix 
M2.
(b) Supplementary Heat Usage
    Appendix M1 requires that HPs undergo a test at 35 [ordm]F dry-bulb 
temperature and 33 [deg]F wet-bulb temperature, a condition for which 
frost accumulation is rapid, generally affecting performance before a 
30-minute steady-state test can be completed. For this condition, the 
test procedure prescribes use of a transient test, including a frost 
accumulation period followed by defrost. Capacity and power input for 
the test are averaged for a full cycle of heating followed by defrost. 
At this condition, appendix M1 estimates the average capacity is at 
least 10 percent lower than it would be if there were no frost 
accumulation, while average power may be just slightly lower, thus 
reducing efficiency. At temperatures between 17 [deg]F and 45 [deg]F, 
the performance calculations prescribed in the test procedure call for 
representing capacity as a linear function of temperature based on the 
tests conducted at 17 [deg]F and 35 [deg]F--likewise for power input. 
Hence, the frost/defrost impact is built into the HSPF2 calculation for 
temperatures in this range. The DOE test procedure requires use of the 
35 [deg]F test for single-stage and two-stage HPs for all capacity 
levels. However, for variable speed HPs, the test procedure requires 
the defrost test be conducted only at intermediate compressor speed, 
and performance is estimated using default degradation factors at full 
capacity (see section 3.6.4.1.c of appendix M1).
    In the January 2023 RFI, DOE noted that it has observed variations 
in testing among HP models regarding defrost control (e.g., time 
durations of the defrost can vary significantly for different models, 
and the indoor unit fan shuts off during defrost for some units but not 
all). 88 FR 4091, 4104. In addition, as part of testing systems with 
electric resistance heaters for the DOE CCHP Tech Challenge, DOE noted 
that it has observed that resistance heater operation during defrost 
can vary significantly for different models. (Id.) DOE acknowledged 
that this varying behavior clearly affects energy use, and, while some 
aspects of resistance heater operation may be captured by the current 
appendix M1 test procedure, others may not be.
    As a result, in the January 2023 RFI, DOE requested information 
regarding defrost impact on heating capacity and power input over a 
range of temperatures to inform evaluation of whether the approach used 
in the DOE test procedure to account for this impact is accurate or 
whether it could be improved.
    In response, Daikin commented that it believes the current appendix 
M1 test conditions represent the worst-case scenario and adequately 
capture performance during frosting and defrosting operation. (Daikin, 
No. 16 at pp. 9-10) As such, Daikin asserted that additional test 
points would provide little benefit. (Id.) Similarly, neither AHRI nor 
Rheem had any concerns with the current testing approach. (AHRI, No. 14 
at p. 13; Rheem, No. 12 at p. 8)
    However, Daikin, the Joint Advocates, and NEEA all suggested that 
DOE somehow include auxiliary resistance heat during defrost as part of 
the defrost test, claiming it would be more representative to include 
this power. (Daikin, No. 16 at p. 12; Joint Advocates, No. 8 at p. 3; 
NEEA, No. 13 at p. 8) Currently, the appendix M1 test procedure 
specifies that electric heat is not to be powered during the defrost 
test, regardless of whether a unit may do so in the field. To try and 
estimate the change in efficiency that comes with including auxiliary 
resistance heat, the Joint Advocates cited a recent Purdue study of a 
3-ton, single-stage heat pump, which calculated a COP at 34 [deg]F that 
was 10-percent lower when the auxiliary heat was allowed to operate in 
defrost.\84\ (Joint Advocates, No. 8 at p. 3) Acknowledging that many 
test facilities are not designed to handle the power required for 
auxiliary heat operation, Daikin suggested that power be added to the 
defrost test energy consumption and capacity as a calculation only, 
based on the maximum allowable power for a given HP system. (Daikin, 
No. 16 at p. 12)
---------------------------------------------------------------------------

    \84\ See docs.lib.purdue.edu/cgi/viewcontent.cgi?article=3475&context=iracc at p. 6. The 34 [deg]F 
outdoor ambient test condition is taken from EXP07.
---------------------------------------------------------------------------

    NYSERDA and the Joint Advocates both noted that as a load-based 
test, SPE07 would inherently address defrost impacts, including power 
input and capacity loss, and require no separate test. (Joint 
Advocates, No. 8 at pp. 3-4; NYSERDA, No. 9 at pp. 10-11)
    As previously mentioned, AHRI and other stakeholders, including 
DOE, discussed several topics raised in the January 2023 RFI, including 
the topic of accounting for supplementary heat usage (e.g., auxiliary 
resistance heat) in the CAC/HP efficiency metrics, when considering 
updated versions of industry standards. The information provided in the 
aforementioned comments was discussed in detail in the development of 
AHRI 1600-202X Draft, which accounts for use of supplementary heat 
during defrost. The AHRI 1600-202X Draft approach reduces the 
efficiency ratings of such systems, depending on: (1) whether the HP 
uses what is defined as defrost heat mode; (2) whether the HP meets 
what is defined as the lockout limitation criteria; and (3) the time 
period for which the HP operates in what is defined as defrost overrun 
mode. The definitions for defrost heat mode, lockout limitation, and 
defrost overrun mode in AHRI 1600-202X Draft are shown below.
    Defrost Heat Mode means a mode of operation in which an indoor 
heating source controlled by any component of the rated combination 
(e.g., by the heat pump, heat pump controls, blower controls, or 
thermostat) operates for any period of time while the system is 
defrosting. Heat pump systems that have the ability to operate the 
indoor blower during defrost, whether or not that ability is the 
manufacturer default, are considered to have a Defrost Heat Mode.
    Defrost Overrun Mode means a mode of operation in which a rated 
individual combination that has been operating in a Defrost Heat Mode, 
continues to operate for a period of time following the termination of 
a defrost. In order to qualify as having a Defrost Overrun Mode, rated 
individual combinations must first have a Defrost Heat Mode.
    Lockout Limitation means rated individual combinations that lock 
out the operation of all non-heat pump indoor heating sources under the 
control of the rated individual

[[Page 24238]]

combination during defrost do not have a Defrost Heat Mode. Locking out 
means preventing those heating sources from operating in all cases, 
with no configuration option to change this behavior.
    AHRI 1600-202X Draft introduces two new debits, multiplied to the 
new heating metric, SHORE, in the same manner as the demand defrost 
credit, to penalize the efficiency ratings of HPs that use defrost heat 
mode (unless they meet the lockout limitation criteria) or spend a 
period of time greater than or equal to 60 seconds in defrost overrun 
mode. One such debit is the defrost heat debit (``FH''), 
which is meant to reflect the reduction in efficiency experienced by 
HPs that use defrost heat mode and can be either one of two values: 
0.98 (for systems with a defrost heat mode) or 1 (for systems that meet 
the lockout limitation criteria). The second debit is the defrost 
overrun debit (``FO''), which is meant to reflect the 
reduction in efficiency experienced by HPs that spend longer time 
periods in defrost overrun mode and can be either one of two values: 
0.98 (for systems with a defrost overrun mode greater than or equal to 
60 seconds) or 1.00 (for systems with a defrost overrun mode less than 
60 seconds, or systems that meet the lockout limitation criteria).
    DOE surmises that the AHRI 1600-202X Draft's introductions of the 
defrost heat debit, the defrost overrun debit, and the associated 
definitions for defrost heat mode, lockout limitation, and defrost 
overrun mode represent industry consensus regarding whether and how to 
include the additional power consumption required by supplementary heat 
(e.g., auxiliary resistance heat) in the defrost test. DOE has 
tentatively determined that these provisions result in more 
representative CAC/HP efficiencies for models with supplementary heat 
during defrost. Therefore, DOE is proposing to incorporate by reference 
at appendix M2 the defrost heat debit, the defrost overrun debit, and 
the associated definitions for defrost heat mode, lockout limitation, 
and defrost overrun mode in AHRI 1600-202X Draft.
3. Updates to Building Load Lines and Temperature Bin Hours
    In the current CAC/HP test procedure at appendix M1, the cooling 
efficiency metric, SEER2, is calculated by evaluating the ratio of the 
heating removed from the conditioned space to the energy use of the 
refrigeration cycle during the cooling season. For CHPs, the heating 
efficiency metric, HSPF2, is calculated by evaluating the ratio of the 
heating provided to the conditioned space to the space energy usage of 
both the CHP unit (reverse refrigeration cycle) and the resistive heat 
component, during the heating season. For the evaluation of SEER2 and 
HSPF2, the respective ratios are summed over a temperature range, which 
is split into 5-degree ``bins,'' and an average temperature and 
fractional hours are assigned to each bin, denoted by n(j)/N. The 
cooling season fractional hours, used in the evaluation of SEER2, are 
set forth at Table 19 of appendix M1. The heating season fractional 
hours, used in the evaluation of HSPF2, are set forth at Table 20 of 
appendix M1. The HSPF2 rating is calculated using the fractional hours 
particular to Region IV. The amount of cooling and/or heating delivered 
are driven by the building cooling and heating loads, 
BL(Tj).\85\ For the current test procedure, the building 
cooling and heating loads are both proportional to the nominal cooling 
capacity at 95 [deg]F outdoor temperature, Qc(95 [deg]F), except for 
heating-only heat pumps, for which the heating load is directly 
proportional to the nominal heating capacity at 47 [deg]F outdoor 
temperature, Qh(47 [deg]F).
---------------------------------------------------------------------------

    \85\ The building cooling load and building heating load are 
calculated by Equations 4.1-2, and 4.2-2, respectively, in appendix 
M1.
---------------------------------------------------------------------------

    In response to the January 2023 RFI, NYSERDA encouraged DOE to 
reevaluate the fractional cooling bin hours used for calculating SEER2. 
(NYSERDA, No. 9 at pp. 9-10) NYSERDA pointed out that these fractional 
cooling bin hours were originally developed in 1978 specifically for 
units with a two-speed compressor and units equipped with two 
compressors. (Id.) NYSERDA suggested that these hours should be 
recalculated using more recent Typical Meteorological Year (``TMY'') 
data, and also consider the improvements in CAC/HP technology since 
1978. (Id. at p. 10)
    As previously mentioned, AHRI 1600-202X Draft includes new cooling 
and heating metrics for namely SCORE and SHORE. These new metrics use 
total hours instead of fractional hours. This change is consistent with 
the recent approach of having metrics that represent total conditioning 
delivered divided by all power consumed. Total hours are split into 
conditioning hours and shoulder hours--conditioning hours are hours 
when conditioning (cooling/heating) is required and shoulder hours are 
hours when conditioning (cooling/heating) is not required (i.e., there 
is no conditioning load). For the cooling season, the total hours are 
split into cooling conditioning hours and cooling season shoulder 
hours. For the heating season, the total hours are split into heating 
conditioning hours and heating season shoulder hours. The cooling 
conditioning hours and cooling season shoulder hours for each bin are 
listed in Table 13 of AHRI 1600-202X Draft, and the heating 
conditioning hours and heating season shoulder hours for each bin are 
listed in Table 15 of AHRI 1600-202X Draft.
    The total hours for the cooling and heating seasons were calculated 
using TMYx:2007-2021 data (``TMYx''), which is a specific set of 
weather data from years 2007 to 2021. Because SCORE and SHORE are 
intended to be national efficiency standards, the total hours for each 
season were population-weighted. Multiple cities were selected, based 
on their population, from each climate zone specified in ASHRAE 169-
2021,\86\ for capturing the variations in climate along those zones. To 
determine the appropriate split between conditioning hours (i.e., when 
cooling/heating is required) and shoulder hours (i.e., when cooling/
heating is not required), Pacific Northwest National Laboratory 
(``PNNL'') performed a series of building load analyses using 
EnergyPlus version 9.6 on a prototype single-family detached house 
based on the 2009 IECC code, located in representative cities in ASHRAE 
climate zones 1-8. The inputs for the EnergyPlus simulations were 
selected to largely mirror those that had been previously used in 
informing the January 2017 Final Rule, but with appropriate updates to 
the weather data and the IECC code.\87\ The underlying weather data was 
updated to TMYx and the IECC building code was updated to the 2009 
version. The data from each individual EnergyPlus simulation output was 
binned and yielded the cooling conditioning hours, cooling season 
shoulder hours, heating conditioning hours, and heating season shoulder 
hours for each climate zone, which were then population-weighted to 
arrive at the national numbers in Table 13 and Table 15 of AHRI 1600-
202X Draft. Additionally, for CAC/HPs

[[Page 24239]]

located in cold climates, Table 15 of AHRI 1600-202X Draft also 
includes the ``Cold Climate Average'' heating conditioning hours and 
heating shoulder hours. These were calculated by a population-weighted 
average of the data from EnergyPlus simulations for the colder climate 
ASHRAE zones 5-8.
---------------------------------------------------------------------------

    \86\ ASHRAE 169-2021 ``Climatic Data for Building Design 
Standards'' provides a variety of climatic information used mainly 
the design, planning and sizing of buildings' energy systems and 
equipment. Available for purchase at www.ashrae.org/technical-
resources/bookstore/weather-data-
center#:~:text=Standard%20169%2D2021%2C%20Climatic%20Data,the%202021%
20ASHRAE%20Handbook%E2%80%94Fundamentals.
    \87\ For the January 2017 Final Rule, the building load analysis 
done by ORNL using EnergyPlus is summarized in the following report: 
ORNL, Rice, C. Keith, Bo Shen, and Som S. Shrestha, 2015. An 
Analysis of Representative Heating Load Lines for Residential HSPF 
Ratings, ORNL/TM-2015/281, July. (Docket No. EERE-2009-BT-TP-0004-
0046).
---------------------------------------------------------------------------

    Regarding updates to the building load lines, the PNNL EnergyPlus 
simulations also yielded the average cooling and average heating loads 
for each climate zone, binned by temperature intervals of 5 [deg]F. The 
results obtained were largely consistent with the building load lines 
(BL(Tj)) in the current appendix M1, barring the minor 
flattening of the building load near the zero-load points. As such, the 
equations used for calculating the building loads were `split' into two 
sections in AHRI 1600-202X Draft. The cooling building load line for 
outdoor temperatures at and above 72.5 [deg]F was maintained consistent 
with current appendix M1, but with one change--requiring that the 
multiplier `V' in the cooling building load line apply to all variable-
capacity compressor systems instead of just variable-capacity heat 
pumps.
    For outdoor temperatures above 72.5 [deg]F, the cooling building 
load line was modified, given by:
[GRAPHIC] [TIFF OMITTED] TP05AP24.052

    Where BL(47.5) is the cooling building load at 72.5 [deg]F.
    Similarly, the heating building load line for outdoor temperatures 
at and below 47.5 [deg]F was maintained consistent with current 
appendix M1, but with one change--requiring that the slope (adjustment) 
factor,Cx, be set to 1.07 for variable-capacity compressor systems, and 
1.15 otherwise, regardless of climate zone.
    For outdoor temperatures above 47.5 [deg]F, the heating building 
load line was modified, given by:
[GRAPHIC] [TIFF OMITTED] TP05AP24.053

    Where BL(47.5) is the heating building load at 72.5 [deg]F.
    DOE surmises that the switch from fractional hours to total hours, 
the associated values of the conditioning hours and shoulder hours, and 
changes in the building load line equations represent industry 
consensus for calculations of the new cooling and heating performance 
metrics, SCORE and SHORE. DOE has tentatively determined that this 
approach best represents CAC/HP operation over a representative period 
of use. Therefore, DOE is proposing to incorporate by reference the new 
cooling conditioning hours, cooling season shoulder hours, heating 
conditioning hours, heating season shoulder hours, and the updated 
building load line equations in the AHRI 1600-202X Draft, at appendix 
M2. DOE is also clarifying that representations of SHORE made using the 
`Cold Climate Average' heating conditioning hours and shoulder season 
hours in Table 15 of AHRI 1600-202X Draft are optional.
4. Default Fan Power Coefficients for Coil-Only Systems
    Coil-only air conditioners are matched split systems consisting of 
a condensing unit and indoor coil that are distributed in commerce 
without an indoor blower or separate designated air mover. Such systems 
installed in the field rely on a separately installed furnace or a 
modular blower for indoor air movement. Because coil-only CAC/HPs do 
not include their own indoor fan to circulate air, the DOE test 
procedures prescribe equations that are used to calculate the assumed 
(i.e., ``default'') power input and heat output of an average furnace 
fan with which the test procedure assumes the indoor coil is paired in 
a field installation. In each equation, the measured airflow rate (in 
cubic feet per minute of standard air (``scfm'')) is multiplied by a 
defined coefficient (expressed in Watts (``W'') per 1000 scfm (``W/1000 
scfm'') for fan power, and Btu/h per 1000 scfm (``Btu/h/1000 scfm'') 
for fan heat), hereafter referred to as the ``default fan power 
coefficient'' and ``default fan heat coefficient.'' The resulting fan 
power input value is added to the electrical power consumption measured 
during testing. The resulting fan heat output value is subtracted from 
the measured cooling capacity of the CAC/HP for cooling mode tests and 
added to the measured heating capacity for heating mode tests.
    In appendix M1, separate fan power and fan heat equations are 
provided for different types of coil-only systems (e.g., the equations 
for mobile home or space-constrained are different than for 
``conventional'' non-mobile home and non-space-constrained, and the 
equations for single-stage are different than for two-stage and 
variable speed).\88\ See, e.g., appendix M1, section 3.3. For single-
stage coil-only units installed in mobile homes and for single-stage 
space-constrained systems, appendix M1 defines a default fan power 
coefficient of 406 W/1000 scfm and a default fan heat coefficient of 
1385 Btu/h/1000 scfm. See, e.g., appendix M1, section 3.3.d. For 
single-stage coil-only units installed in ``conventional'' (i.e., non-
mobile-home and non-space-constrained) systems, appendix M1 defines a 
default fan power coefficient of 441 W/1000 scfm and a default fan heat 
coefficient of 1505 Btu/h/1000 scfm. See, e.g., appendix M1, section 
3.3.e.
---------------------------------------------------------------------------

    \88\ The different default fan power and default fan heat 
coefficients for mobile-home and space-constrained systems as 
compared to conventional systems reflect the lower duct pressure 
drop expected for such systems in field operation--the lower values 
are consistent with the lower ESP levels required in testing of 
blower-coil systems intended for mobile home and spaced-constrained 
applications (see Table 4 of appendix M1).
---------------------------------------------------------------------------

    For two-stage and variable speed coil-only systems, appendix M1 
defines equations to interpolate different default fan power 
coefficients and default fan heat coefficients for the full-load and 
part-load tests, depending on the air volume rate used for each test 
expressed as a percentage of the cooling full-load air volume rate 
(``%FLAVR''). See, e.g., appendix M1, section 3.3, equations for 
DFPCMHSC and DFPCC. Appendix M1 interpolates the 
default fan power coefficient for two-stage and variable speed coil-
only units installed in mobile homes and for two-stage and variable 
speed space-constrained coil-only systems (``DFPCMHSC'') 
using assumptions for full-load default fan power at 406 W (i.e., the 
same as for single-stage systems) and a lower-load default fan power at 
a reduced air volume rate of 75 percent, at 308 W. For ``conventional'' 
non-mobile-home and non-space-constrained two-stage and variable speed 
systems, appendix M1 interpolates the default fan power coefficient 
(``DFPCC'') using assumptions for full-load default fan 
power at 441 W (i.e., the same as for single-stage systems) and a 
lower-load default fan power at a reduced air volume rate of 75 
percent, at 335 W. The default fan power values used in the 
determination of the default fan power coefficients were a result of 
empirical analysis presented by DOE in the October 2022 Final Rule. 
(See 87 FR 64550, 64555-64559).
    As previously mentioned, AHRI and other stakeholders, including 
DOE, considered several topics, including the topic of default fan 
power coefficients for coil-only systems, when developing updated 
versions of industry standards. AHRI 1600-202X Draft updates the 
default fan power values used in each interpolation to better reflect 
the fan power values used by coil-only systems today (on average) and 
changes the equations for default fan power

[[Page 24240]]

coefficients to use lower-load default fan powers at a reduced air 
volume rate of 65 percent, rather than 75 percent as in appendix M1. 
For space-constrained coil-only systems, the AHRI 1600-202X Draft uses 
a full-load default fan power of 293 W and a lower-load default fan 
power of 135 W in the default fan power coefficient interpolation. For 
non-space-constrained coil-only systems, AHRI 1600-202X Draft uses a 
full-load default fan power of 346 W and a lower-load default fan power 
of 159 W. All default fan powers are lower than those used in the 
calculation of DFPCMHSC and DFPCC in appendix M1. 
DOE surmises that the new equations for default fan power coefficients 
and default fan heat coefficients (and their reduced full-load default 
fan powers and their reduced lower-load default fan powers at a reduced 
air volume rate of 65 percent) in AHRI 1600-202X Draft represent 
industry consensus regarding the assumed power input and heat output of 
an average furnace fan or modular blower with which the test procedure 
assumes the indoor coil is pared in a field installation. DOE has 
tentatively determined that the reduced full-load and low-load default 
fan powers more accurately reflect the average design of the current 
installed base for blowers paired with coil-only CAC/HP installations, 
which increasingly use more efficient fan motors (with lower wattages). 
DOE has also tentatively determined that the reduced air volume rate 
more accurately reflects the average low-load air volume rate of the 
current installed base for blowers paired with coil-only CAC/HP 
installations. Therefore, DOE is proposing to incorporate by reference 
the default fan power coefficient equations and default fan heat 
coefficient equations, and associated default fan powers used to 
interpolate such coefficients, in AHRI 1600-202X Draft, at appendix M2.
5. Indoor Ambient Test Conditions for Cooling Mode Tests
    Currently, appendix M1 prescribes test conditions for CAC/HPs in 
Tables 5, 6, 7, and 8 that require all cooling mode tests to be 
performed under air entering indoor unit temperatures of 80 [deg]F 
(dry-bulb temperature)/67 [deg]F (wet-bulb temperature), with some wet-
bulb temperature exceptions.
    In response to the January 2023 RFI, DOE received several comments 
regarding these indoor ambient test conditions. As mentioned previously 
in this NOPR, the Joint Advocates encouraged DOE to choose more 
representative indoor air temperatures for the cooling mode tests. 
(Joint Advocates, No. 8 at p. 3) Specifically, the Joint Advocates 
referred to an ACEEE paper \89\ that suggests indoor temperatures of 75 
[deg]F/63 [deg]F would be more representative than the 80 [deg]F/67 
[deg]F conditions currently used in appendix M1. (Id.) The Joint 
Advocates also referred to recommendation 4 of the 2022 ASRAC CUAC and 
CUHP WG TP term sheet, which recommends return air temperature 
(``RAT'') test conditions for cooling at 77 [deg]F/64 [deg]F, not 80 
[deg]F/67 [deg]F, to calculate seasonal performance metrics. (Id.) 
Similarly, NYSERDA also recommended that DOE consider revising the air 
entering indoor unit temperature conditions in the cooling mode tests, 
asserting that the conditions are not representative of actual 
setpoints in the field, per 2020 RECS data.\90\ (NYSERDA, No. 9 at p. 
9)
---------------------------------------------------------------------------

    \89\ See www.aceee.org/files/proceedings/2006/data/papers/SS06_Panel1_Paper24.pdf.
    \90\ See www.eia.gov/consumption/residential/data/2020/hc/pdf/HC%207.1.pdf.
---------------------------------------------------------------------------

    In its comments regarding the comparison of appendix M1 test 
conditions to those test conditions used by SPE07, Daikin pointed out 
that changing the indoor dry-bulb and wet-bulb temperature conditions 
would significantly alter the numerical value of resultant efficiency 
metrics. (Daikin, No. 16 at p. 5) Specifically, Daikin estimated that 
changing the indoor ambient test conditions from 80 [deg]F/67 [deg]F to 
75 [deg]F/63 [deg]F alone would result in an approximate 9-percent 
reduction in capacity (and therefore efficiency), although Daikin could 
not share its data to back this estimate. (Id.) If the indoor ambient 
test conditions were to change, Daikin stated that the numerical shift 
should not affect the ranking order of CAC/HPs by measured 
efficiencies. (Id.) Daikin also noted that requiring additional testing 
at different test conditions would increase time burden, costs, and 
trouble for manufacturers. (Id.)
    The information provided in the aforementioned comments was 
discussed in detail in the development of the AHRI 1600-202X Draft, 
which maintained the existing indoor ambient test conditions for 
cooling tests. DOE surmises that this absence of change tentatively 
represents industry consensus regarding whether the existing 80 [deg]F/
67 [deg]F indoor ambient test conditions require amendments at this 
time. DOE has tentatively determined that the potential benefits of 
such a change would not outweigh the resulting consumer confusion and 
oversizing issues stemming from a change to the nominal ratings of 
systems. Therefore, DOE is proposing no change to the current indoor 
ambient test conditions for the cooling mode tests.
6. Air Flow Limits To Address Inadequate Dehumidification
    During the development of AHRI 1600-202X Draft, AHRI and other 
stakeholders, including DOE, considered a variety of topics regarding 
CAC/HPs, including topics that were not explicitly raised by issues 
presented in the January 2023 RFI. Among those topics was how to 
address issues relating to the dehumidification inadequacy of some CAC/
HPs. Some CAC/HPs have sensible heat ratios (``SHRs'') too high to meet 
consumer needs for dehumidification, especially in hot and warm, humid 
climates.
    To ensure that CAC/HPs ratings account for adequate 
dehumidification in these climates, the AHRI 1600-202X Draft 
establishes new airflow limits for the cooling mode tests to avoid high 
SHRs. Specifically, section 6.1.5.2 of the AHRI 1600-202X Draft sets a 
maximum airflow limit at 37.5 scfm per 1000 Btu/h (i.e., 450 cfm per 
ton of capacity) for cooling full airflow. Additionally, section 
6.1.5.3 of the AHRI 1600-202X Draft sets a maximum airflow limit at 50 
scfm per 1000 Btu/h (i.e., 600 cfm per ton of capacity) for cooling low 
airflow. Should the cooling full airflow or cooling low airflow 
specified by the manufacturer exceed these limits, the AHRI 1600-202X 
Draft requires that airflows be reduced to meet these limits for 
testing.
    DOE surmises that the addition and selection of specific cooling 
airflow limits in the AHRI 1600-202X Draft represent industry consensus 
regarding the issue of inadequate dehumidification. DOE has tentatively 
determined that such airflow limits are appropriate to ensure that CAC/
HPs provide adequate dehumidification during cooling mode operation. 
Therefore, DOE is proposing to incorporate by reference the cooling 
full airflow and cooling low airflow limits specified in the AHRI 1600-
202X Draft, at appendix M2.

H. General Comments Received in Response to the January 2023 RFI

    In response to the January 2023 RFI, DOE received several general 
comments not specific to any one test procedure provision. This section 
discusses those general comments received.
    Both AHRI and NCP commented that the requirement to test according 
to appendix M1 (effective January 1, 2023), specifically the change to 
SEER2 and HSPF2 metrics, caused considerable confusion in the 
marketplace. (AHRI, No. 14 at p. 4; NCP, No. 7 at p. 2) As

[[Page 24241]]

a result of the metrics change (and lower values for efficiency for 
SEER2 and HSPF2), AHRI and NCP explained that they and other 
manufacturers worked together to develop educational resources for 
dealers, contractors, code officials, and end-users in an effort to 
quell confusion. (Id.) However, AHRI stated that distributing such 
resources was difficult considering the large number of contractors and 
installers in jurisdictions across the nation. (Id.) Both AHRI and NCP 
commented that the burden associated with the previous metrics change 
to SEER2 and HSPF2 was not well accounted for in the last test 
procedure rulemaking. (Id.) Subsequently, NCP stated that DOE should 
allow time to measure the overall impact of the new appendix M1 ratings 
and assess any actual benefit before undertaking additional steps to 
amend the procedure in this test procedure rulemaking. (NCP, No. 7 at 
p. 2)
    As noted earlier, DOE is proposing to incorporate by reference 
industry standards at appendix M1 and appendix M2, which were developed 
with the broad consensus of several stakeholders, including AHRI and 
NCP. It is DOE's hope that incorporating each industry standard in full 
as the basis for each respective appendix would enable DOE to limit 
manufacturer burden that would have otherwise arisen solely due to 
certifying to a standalone Federal test procedure. DOE has tentatively 
determined that the revisions proposed at appendix M1 would not result 
in changes in the SEER2 and HSPF2 metrics, and notes that use of 
appendix M2 would not be required until the compliance date of any 
amended standards denominated in terms of the new metrics, SCORE and 
SHORE. Additionally, DOE has assessed the test procedure costs and 
impacts in section III.M of this NOPR and has provided an opportunity 
to comment.
    Lennox stated that DOE should fully consider the impacts of 
transitioning to lower GWP refrigerants as part of the test procedure 
rulemaking process. (Lennox, No. 6 at p. 2) Lennox commented that HVACR 
manufactures will be investing millions of dollars in product 
development and capital investment to facilitate a transition across 
the entire HVACR product portfolio of residential and commercial 
equipment and that these impacts must be considered in this test 
procedure rulemaking. (Id.)
    DOE notes that Lennox did not identify any specific impacts related 
to transitioning to low GWP refrigerants. As discussed in section 
III.F.5, DOE has considered that with the use of low GWP refrigerants, 
particularly A2L refrigerants, a subsequent need may exist for the 
constant circulation of air or circulation based on leak detection to 
accommodate the refrigerant leak detection and mitigation strategies in 
CAC/HP product design. Both the AHRI 210/240-202X Draft and AHRI 1600-
202X Draft include provisions for such systems, which DOE is 
incorporating by reference at appendix M1 and appendix M2, 
respectively. Lennox was involved in the development of these industry 
standards and DOE surmises that Lennox's concerns pertaining to impacts 
of lower GWP refrigerants have been appropriately addressed.
    Lennox also stated that DOE should exercise caution as it proceeds 
with test procedure amendments for CAC/HP products to ensure the 
impacts and timing of test procedure amendments are fully considered, 
particularly so that manufacturers may fully evaluate any test 
procedure impacts before DOE assesses potentially amending energy 
conservation standards. (Lennox, No. 6 at p. 2)
    In response to Lennox, DOE notes that both test procedures and 
energy conservation standards actions are subject to the requirements 
of EPCA. As discussed, EPCA states that the Secretary shall review test 
procedures for all covered products, including CAC/HPs, at least once 
every 7 years. (see 42 U.S.C. 6293(b)(1)(a)) The most recent CAC/HP 
test procedure rulemaking completed in satisfaction of EPCA's 7-year 
review requirement concluded with the January 2017 Final Rule. (See 82 
FR 1426). Similarly, EPCA also requires that, not later than 6 years 
after the issuance of any final rule establishing or amending a 
standard, DOE evaluate the energy conservation standards for each type 
of covered product, including CAC/HPs, and publish either a 
notification of determination that the standards do not need to be 
amended, or a NOPR that includes new proposed energy conservation 
standards (proceeding to a final rule, as appropriate). (See 42 U.S.C. 
6295(m)(1)) The most recent CAC/HP energy conservation standards 
rulemaking completed in satisfaction of EPCA's 6-year review 
requirement concluded with a direct final rule published on January 6, 
2017 (``January 2017 ECS DFR''). (See 82 FR 1786). As noted, revisions 
proposed at appendix M1 would not result in changes in the SEER2 and 
HSPF2 metrics, and use of appendix M2 would not be required until the 
compliance date of any amended standards denominated in terms of the 
new metrics, SCORE and SHORE. DOE has tentatively determined that this 
proposed test procedure structure would provide sufficient time to 
assess new metrics when considering any future amended energy 
conservation standards.
    While Lennox stated it supports test procedure changes to improve 
the representativeness of the CAC/HP test procedures, it also 
emphasized that such changes must not be unduly burdensome. (Lennox, 
No. 6 at p. 4) Similarly, NCP stated that DOE should avoid amendments 
to the test procedure that increase burden and noted that EPCA requires 
test procedures to not be unduly burdensome. (NCP, No. 7 at p. 2) 
Specifically, NCP stated that DOE should avoid amendments to the test 
procedure that increase burden for space-constrained AC and HP 
products, as it has found no significant benefits to be attained by 
test procedure changes to this type of product at this time. (Id.)
    As discussed previously, EPCA requires test procedures proposed by 
DOE not be unduly burdensome to conduct. (See 42 U.S.C. 6293(b)(3)) DOE 
discusses the estimated costs and impact of the proposed test 
procedures at appendix M1 and appendix M2 in section III.M of this 
NOPR. As noted earlier, DOE is proposing to incorporate by reference 
industry standards at appendix M1 and appendix M2 that were developed 
with the broad consensus of several stakeholders, including Lennox and 
NCP. DOE has tentatively determined that incorporating each industry 
standard in full as the basis for each respective appendix would limit 
manufacturer burden.
    AHRI requested that DOE parse test procedure changes into separate 
groupings, so stakeholders can understand those changes that would 
substantively impact the ratings and, if possible, the extent of their 
impact. (AHRI, No. 14 at p. 4)
    In response, DOE notes that it has categorized the proposed test 
procedures by topic and timing of changes (i.e., near-term changes at 
appendix M1 versus long-term changes at appendix M2) to assist in 
manufacturers' understandings of the changes themselves and the impacts 
they may pose.
    The Joint Advocates encouraged DOE to consider additional reporting 
requirements in a test procedure rulemaking. (Joint Advocates, No. 8 at 
p. 4) Specifically, the Joint Advocates asserted that the ability for 
various stakeholders to calculate performance in any climate will 
likely be very important for the adoption of heat pumps in coming 
years. (Id.) Subsequently, the Joint Advocates

[[Page 24242]]

encouraged DOE to engage stakeholders to determine which additional 
performance reporting requirements would be beneficial (e.g., capacity 
maintenance or COP at various temperatures) in a test procedure 
rulemaking. (Id.)
    In response, DOE notes that it will consider certification 
requirements for CAC/HPs, including additional reporting requirements 
mentioned by the Joint Advocates, in a separate rulemaking for 
certification, compliance, and enforcement.
    NYSERDA recommended that DOE consider approaches in the test 
procedure that address both demand response-enabled and thermal storage 
performance features of CAC/HPs. (NYSERDA, No. 9 at p. 14) To highlight 
the potential opportunities for load curtailment using demand response, 
NYSERDA stated that it evaluated outdoor temperatures greater than or 
equal to 95 [deg]F for certain U.S.-based cities. (NYSERDA, No. 9 at p. 
14) NYSERDA stated that it then developed charge and discharge pattern 
estimates using renewable portfolio standards (``RPS'') as a pathway to 
generation while relying on the energy storage perspectives offered in 
a California Independent System Operator Corporation (``CAISO'') report 
on California and Europe.\91\ (Id.) NYSERDA stated that these estimates 
are summarized in Figure 1 of NYSERDA's response to the January 2023 
RFI. (Id.) NYSERDA commented that several high outdoor temperatures 
within Figure 1 fall within the charge zone associated with lower-price 
periods and high generation and contended that the small percentage of 
outdoor temperatures within the discharge zone (i.e., higher price 
periods with peak demand) could be managed using the general 
curtailment and critical curtailment approaches specified in AHRI 
Standard 1380-2019. (Id.)
---------------------------------------------------------------------------

    \91\ See www.caiso.com/Documents/EnergyStorage-PerspectivesFromCalifornia-Europe.pdf.
---------------------------------------------------------------------------

    Additionally, NYSERDA noted that specifications issued by EPA and 
the Consortium for Energy Efficiency (``CEE'') prescribe connected 
criteria for demand response-enabled products, and that energy 
efficiency program administrators may consider offering incentives on 
connected criteria to strategically manage peak load outside of solely 
focusing on performance metrics such as SEER2, HSPF2, and EER2. 
(NYSERDA, No. 9 at p. 14) NYSERDA recommended that DOE account for such 
demand response-enabled features in the revised test procedure, for 
example, by down-weighting or eliminating the bin hours from the SEER2 
rating above a typical curtailment threshold. (Id.) NYSERDA stated that 
this could be provided as a secondary metric so that users who choose 
not to participate in demand-response programs would still have access 
to the ``normal'' SEER2 rating for comparison. (Id.)
    Neither AHRI 210/240-202X Draft nor AHRI 1600-202X Draft include 
any provisions regarding demand response-enabled products. In the 
absence of discussion or changes to the AHRI test procedures, DOE 
surmises that no changes need to be made regarding demand response-
enabled CAC/HP products in the test procedures at this time. Therefore, 
DOE is proposing no provisions to address demand response-enabled CAC/
HP products in the test procedures at either appendix M1 or appendix 
M2. DOE will continue to evaluate demand response functions in CAC/HPs 
and consider whether such functions should be accounted for in a future 
DOE test procedure. While DOE is not proposing changes to the Federal 
test procedures, DOE does note that the ENERGY STAR Spec V6.1 includes 
requirements for demand response capability and provides a means for 
product differentiation.
    NYSERDA also commented that it has been working with heat pump 
technologies that incorporate thermal storage,\92\ and suggested that 
this technology would fit under DOE's CAC/HP test procedure rulemaking. 
(NYSERDA, No. 9 at pp. 14-15) NYSERDA recommended that DOE consider if 
this technology may make sense to be a standalone product category or 
otherwise consider the potential growth of this technology and how it 
would fit into the scope of CAC/HPs. (Id.)
---------------------------------------------------------------------------

    \92\ In its simplest form, thermal storage involves using excess 
energy to heat/cool, melt or vaporize a material so that this stored 
energy can be recovered later. Heat pumps with thermal energy 
storage can store energy during times when electricity prices are 
low and release it during peak demand hours.
---------------------------------------------------------------------------

    As previously mentioned, AHRI and other stakeholders, including 
DOE, considered a variety of topics regarding CAC/HPs. However, the 
topic of heat pump technologies that incorporate thermal storage was 
not brought up as a topic for discussion, and neither AHRI 210/240-202X 
Draft nor AHRI 1600-202X Draft include any provisions regarding such 
technologies. Additionally, DOE has tentatively determined that heat 
pumps with thermal storage are a niche application, and DOE currently 
does not have enough information to include test provisions for such 
systems within CAC/HP test procedure. DOE also has not received any 
petitions for test procedure waivers to date that would address this 
technology. In the absence of discussion or changes to the AHRI test 
procedures, DOE has tentatively determined that no provisions are 
currently necessary regarding heat pump technologies that incorporate 
thermal storage in the test procedures at either appendix M1 or 
appendix M2. However, DOE may consider the topic of heat pump 
technologies that incorporate thermal storage in a future rulemaking.

I. Represented Values

    In the following sections, DOE discusses requirements regarding 
represented values. To the extent that DOE is proposing changes to the 
requirements specified in 10 CFR 429 regarding representations of CAC/
HPs, such amendments to 10 CFR part 429, if made final, would be 
required starting 180 days after publication in the Federal Register of 
the test procedure final rule. Prior to 180 days after publication in 
the Federal Register of the test procedure final rule, the current 
requirements would apply. However, manufacturers would be permitted to 
choose between using the current or new requirements for a period 
between 30 days and 180 days after publication in the Federal Register 
of the test procedure final rule.
1. Calculating Represented Values for the Federal Trade Commission
    As described in a final rule regarding EnergyGuide labels published 
on October 12, 2022, the Federal Trade Commission (``FTC'') is 
responsible for periodical updates to energy labeling for major home 
appliances and other consumer products, including CAC/HPs, to help 
consumers compare competing models. 87 FR 61465, 61466. Among other 
disclosures, EnergyGuide labels for CAC/HPs include estimated annual 
energy costs for both cooling and heating, which are based on the 
represented values for each basic model's efficiencies (SEER2 and 
HSPF2, as applicable) and cooling capacities and estimates for cooling 
load hours (``CLH'') and heating load hours (``HLH'') in a year. 
Currently, the FTC uses 1,000 and 1,572 hours as estimates for CLH and 
HLH, respectively, for all ratings of CAC/HP basic models.\93\ In this 
NOPR, DOE is proposing to retain the current CLH and HLH estimates in 
appendix M1, for use in conjunction

[[Page 24243]]

with SEER2 and HSPF2 representations. However, DOE is also proposing 
new estimates for CLH and HLH for use in conjunction with the proposed 
appendix M2 efficiency metrics, SCORE and SHORE. Specifically, DOE is 
proposing to use 1,457 and 972 hours as estimates for CLH and HLH, 
respectively, for use in conjunction with SCORE and SHORE 
representations. Unlike SEER2 and HSPF2, SCORE and SHORE are integrated 
metrics (that include off-mode and standby power) and use updated 
weather data for the United States' average number of conditioning and 
shoulder-season hours per temperature bin. Given the different metrics, 
DOE has tentatively determined that the proposed appendix M2 requires 
new CLH and HLH values for use by the FTC. Step-by-step derivations of 
proposed appendix M2 CLH and HLH values are presented in a docketed 
white paper titled ``Derivation of Proposed Appendix M2 Cooling Load 
Hours and Heating Load Hours for the Federal Trade Commission.'' \94\
---------------------------------------------------------------------------

    \93\ See Table 21 of appendix M1 for the current CLH and HLH 
estimates used for rating values.
    \94\ This paper is available for reference in Docket No. EERE-
2022-BT-TP-0028.
---------------------------------------------------------------------------

2. Off-Mode Power
    Off-mode power, PW,OFF, is a required represented value 
for all CAC/HPs, as specified in 10 CFR 429.16(a)(1). Currently, 
section 3.13 of appendix M1 includes testing instructions to determine 
off mode power ratings for CAC/HPs. As discussed in section III.F.1, 
the revised appendix M1 incorporates by reference AHRI 210/240-202X 
Draft. Section 11.2.3 and appendix H of AHRI 210/240-202X Draft include 
the same test instructions to determine PW,OFF as are 
present in the current appendix M1 and therefore no changes are 
required when representation are made per appendix M1.
    However, as discussed in section III.F.1 of this NOPR, the metrics 
applicable to appendix M2, SCORE and SHORE, incorporate off-mode power 
consumption, unlike the current cooling and heating metrics SEER2 and 
HSPF2, respectively. As such, requiring representation of 
PW,OFF would be redundant for appendix M2. Therefore, DOE is 
proposing to clarify at 10 CFR 429.16(a)(2) that represented values of 
PW,OFF are only required when testing in accordance with 
appendix M1.
    Additionally, 10 CFR 429.16(b)(2)(ii) currently allows flexibility 
for manufacturers to not test each individual model/combination (or 
tested combination) for PW,OFF, but at a minimum, test at 
least one individual model/combination for PW,OFF among 
individual models/combinations with similar off-mode construction. DOE 
is retaining this flexibility for testing to appendix M1. DOE is also 
extending similar flexibility for determining off-mode power values 
P1 (off-mode power in shoulder season) and P2 
(off-mode power in heating season), which are used in the calculation 
of the SCORE and SHORE metrics when testing to appendix M2, but for 
which DOE is not proposing to require represented values.
    Specifically, DOE is proposing at 10 CFR 429.16(b)(2)(iii) that 
when testing in accordance with appendix M2 and determining SCORE and 
SHORE, each individual model/combination is not required to be tested 
for values of P1 (off-mode power in shoulder season) and 
P2 (off-mode power in heating season). Instead, at a 
minimum, among individual models/combinations with similar off-mode 
construction (even spanning different models of outdoor units), a 
manufacturer must test at least one individual model/combination, for 
which P1 and P2 are the most consumptive.
    Issue 3: DOE requests comment on its proposal at 10 CFR 
429.16(b)(2)(iii) to extend testing flexibility to P1 (off-mode power 
in shoulder season) and P2 (off-mode power in heating season) when 
determining SCORE and SHORE, such that each individual model/
combination is not required to be tested for values of P1 and P2.
3. AEDM Tolerance for SCORE and SHORE
    DOE's existing regulations allow the use of an AEDM, in lieu of 
testing, to simulate the efficiency of CAC/HPs. 10 CFR 429.16(d). For 
models certified with an AEDM, results from DOE verification tests are 
subject to certain tolerances when compared to certified ratings. 10 
CFR 429.70(e)(5)(v). The current tolerance specified for efficiency 
metrics for CAC/HPs (i.e., SEER2, HSPF2, and EER2) requires that the 
result from the DOE verification test must be greater than or equal to 
0.95 multiplied by the certified represented value. To maintain 
consistency with the existing efficiency metrics, DOE is proposing to 
extend the same tolerance requirement to the new efficiency metrics 
measured per appendix M2--SCORE and SHORE.
4. Removal of the AEDM Exception for Split-System CAC/HPs
    Currently, the AEDM requirements at 10 CFR 429.70[euro] allow that, 
until July 1, 2024, non-space-constrained single-split-system CAC/HPs 
rated based on testing in accordance with appendix M1 are allowed to 
test a single-unit sample from 20 percent of the basic models 
distributed in commerce to validate the AEDM. On or after July 1, 2024, 
validation of the AEDM has to be based on complete testing of each 
basic model. See 10 CFR 429.70(e)(2)(i)(A). Corresponding provisions 
are also included at 10 CFR 429.16, paragraphs (b)(2)(i) and 
(c)(1)(i)(B).
    Since amendments proposed in this NOPR are not expected to be 
finalized and made effective before July 1, 2024, the aforementioned 
AEDM exception for non-space-constrained single-split-system CAC/HPs 
would no longer apply at the time this rulemaking finalizes. As such, 
DOE is proposing to remove the date-based application of the AEDM 
requirement and instead clarifies that AEDM validation for all CAC/HPs, 
including non-space-constrained single-split-system CAC/HPs, must be 
based on complete testing of each basic model.

J. Enforcement Provisions

1. Verifying Cut-Out and Cut-In Temperatures
    As discussed in section III.E.3 of this NOPR, appendix J of AHRI 
210/240-202X Draft and AHRI 1600-202X Draft--which DOE is proposing to 
incorporate by reference--includes a test to determine cut-out and cut-
in temperatures (i.e., Toff and Ton respectively) 
that is applicable to all HPs. To enable DOE to verify certified cut-
out and cut-in temperatures using the test methods in appendix K of the 
AHRI drafts, DOE is proposing product-specific provisions at 10 CFR 
429.134(k)--specifically, DOE is proposing that for assessment and 
enforcement testing of CHP models, the cut-out and cut-in temperatures 
may be verified using the method in appendix J and that if this method 
is conducted, the cut-in and cut-out temperatures determined using this 
method will be used to calculate the relevant heating metric for 
purposes of compliance.
    DOE will consider certification requirements for CAC/HPs, including 
the potential requirement for certification of cut-out and cut-in 
temperatures, in a separate rulemaking.
2. Controls Verification Procedure
    As discussed in section III.E.1.d of this NOPR, appendix I of AHRI 
210/240-202X Draft and AHRI 1600-202X Draft--which DOE proposes to 
incorporate by reference--includes a CVP to verify compliance of system 
operation with the variable-capacity compressor system definition and 
consistency of fixed-position settings for the compressor and indoor 
fan used in

[[Page 24244]]

steady-state tests with native control operation.
    DOE is proposing provisions at 10 CFR 429.134(k) to establish 
requirements for DOE's use of the CVP for the purposes of assessment 
and enforcement testing. DOE is proposing that after conducting the 
CVP, which itself would be performed after an assessment or enforcement 
test using the DOE test procedure (i.e., a certification test using 
Appendix M1 or Appendix M2, as applicable), if a unit is determined to 
be either a variable-capacity compressor system, variable capacity 
certified, single-capacity system, or variable capacity certified, two-
capacity system, and meets the tolerances on capacity measurement (+/-6 
percent) and efficiency \95\ (+/-10 percent) for the full and minimum 
load CVP intervals, the efficiency metrics for the unit will be 
evaluated by conducting the prescribed DOE rating tests per Appendix M1 
or Appendix M2 applicable to that system. These tests will be conducted 
based on the override instructions from the manufacturer for setting 
the appropriate compressor and fan speeds for each test.
---------------------------------------------------------------------------

    \95\ EER2 for cooling load intervals, and COP2 for heating load 
intervals
---------------------------------------------------------------------------

    However, if either of the full or minimum load CVP intervals fail 
to meet the required tolerances, and the control device allows 
adjustment of the compressor and indoor blower speeds,\96\ DOE will 
conduct certification tests by setting the speeds for the tests to the 
average values observed during the corresponding failed CVP 
interval.\97\ If either of the full or minimum load CVP intervals fail 
to meet the required tolerances, and the control device does not allow 
adjustment of the compressor and indoor blower speeds, DOE will use 
average capacity and power(s) or, for CVP intervals that do not meet 
the operating tolerances and condition tolerances, time averaged 
integrated capacity and time averaged integrated power(s), measured 
during the CVP, in order to calculate SEER2, HSPF2 and EER2 for 
appendix M1, and SCORE, SHORE and EER2, for appendix M2. For 
certification tests that do not have a corresponding CVP interval, the 
corresponding efficiency will be calculated by adjusting the capacity 
and efficiency, by application of a ratio to the corresponding CVP 
interval.\98\
---------------------------------------------------------------------------

    \96\ For the purpose of the CVP, ``adjustment'' means that the 
control device has the ability to make discrete adjustments, as 
required, to the compressor and indoor blower speeds without the 
need of any additional hardware or non-publicly available software.
    \97\ For tests that do not correspond to any load intervals of 
the CVP, DOE will adjust the compressor speed as follows: the 
compressor speeds for tests Bfull, Blow, 
H1,full, H2,full, H2,low and 
H0,low, will be set at the same speeds observed in the 
CVP load intervals associated with the Afull, 
Flow, H3,full, H3,full, and 
H1,low tests, respectively.
    \98\ As an example, the capacity at Bfull condition, 
QB,Full, will be calculated by the following equation: QB,Full, = 
QB,Full,Certification x QCVP,A,Full/QA,Full,Certification, where 
QB,Full,Certification is the capacity at Bfull condition, 
QCVP,A,Full is the full load interval capacity in cooling mode, and 
QA,Full,Certification is the capacity at Afull condition.
---------------------------------------------------------------------------

    For CHPs determined to be variable capacity certified, single 
capacity system, or variable capacity certified, two capacity system 
that are certified/marketed for use with only a proprietary control 
device, DOE may utilize two options, (1) contact the manufacturer to 
provide override control instructions consistent with the full and, if 
applicable, minimum speed operation observed during the CVP, to enable 
tests without a corresponding CVP interval to be conducted at the 
appropriate speeds, or (2) conduct the tests for H1,Nom, 
H2,Full, H2,Low and H3,Low, as 
applicable, using the certified instructions, and for other 
certification tests, the corresponding efficiency will be calculated by 
adjusting the capacity and efficiency, by application of a ratio to the 
corresponding CVP interval.\99\ Otherwise, the same simulated 
thermostat low voltage signal that resulted in in full speed compressor 
operation for the full load intervals shall be used for all 
certification full load tests (for variable capacity certified, single 
capacity system, or variable capacity certified, two capacity systems), 
and the same simulated thermostat low voltage signal that resulted in 
low speed compressor operation for the low load intervals, shall be 
used for all certification low load tests (for variable capacity 
certified, two capacity system).
---------------------------------------------------------------------------

    \99\ As an example, the capacity at HOLow condition, 
QH0,Low, will be calculated by the following equation: QHO,Low, = 
QH0,Low,Certification x QCVP,H1,Low/QH,Low,,Certification.
---------------------------------------------------------------------------

    DOE will address any associated certification requirements for the 
CVP in a separate rulemaking.
    Issue 4: DOE requests comment on its proposals related to 
enforcement provisions when conducting the CVP.

K. Test Procedure Costs and Impact

    EPCA requires that test procedures proposed by DOE not be unduly 
burdensome to conduct. (42 U.S.C. 6293(b)(3)) As discussed, DOE 
proposes to update the current Federal test procedure for CAC/HPs at 
appendix M1 consistent with the most recent draft version of the 
relevant industry consensus test procedure, AHRI 210/240-202X Draft. 
DOE is also proposing a new Federal test procedure at 10 CFR 430, 
subpart B, appendix M2, consistent with the draft version of the 
industry consensus test procedure, AHRI 1600-202X Draft. Appendix M2 
would not be required for use until the compliance date of amended 
standards for CAC/HPs. DOE also proposes to amend its representation 
and enforcement provisions for CAC/HPs.
1. Appendix M1
    In this NOPR, DOE proposes to update its regulations at 10 CFR part 
430, subpart B, appendix M1 by incorporating by reference AHRI 210/240-
202X Draft and relevant industry standards referenced in AHRI 210/240-
202X Draft (ANSI/ASHRAE 37-2009, ANSI/ASHRAE 16-2016, and ANSI/ASHRAE 
116-2010), and amending certain provisions for representations and 
enforcement in 10 CFR part 429, consistent with the changes proposed to 
the test procedure. The proposed revisions to appendix M1 would retain 
the current efficiency metrics (i.e., EER2, SEER2, and HSPF2). The 
proposed testing requirements in appendix M1 are those in AHRI 210/240-
202X Draft, which in turn references ANSI/ASHRAE 37-2009, ANSI/ASHRAE 
16-2016, and ANSI/ASHRAE 116-2010.
    DOE has tentatively determined that the proposed amendments to 
appendix M1 and the proposed representation and enforcement provisions 
would improve the representativeness, accuracy, and reproducibility of 
the test results and would not be unduly burdensome for manufacturers 
to conduct. DOE has also tentatively determined that the proposed 
amendments would not result in an increase in testing cost from the 
current test procedure. The proposed revisions to the test procedure in 
appendix M1 for measuring EER2, SEER2, and HSPF2 per AHRI 210/240-202X 
Draft would not increase third-party laboratory testing costs per unit 
relative to the current DOE test procedure. DOE estimates the current 
costs for physical testing, including off-mode testing, to range from 
$10,800 to $19,800, depending on the configuration of the CAC/HP 
(single-stage, two-stage, variable-capacity). Further, DOE has 
tentatively concluded that the proposed revisions to the test procedure 
in appendix M1 would not change efficiency ratings for CAC/HPs, and 
therefore would not require retesting or redesign solely as a result of 
DOE's adoption of the proposed amendments to the DOE test procedure, if 
made final.\100\
---------------------------------------------------------------------------

    \100\ Manufacturers are not required to perform laboratory 
testing on all basic models. In accordance with 10 CFR 429.16, CAC/
HP manufacturers may elect to use AEDMs. 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 to reduce the burden and cost 
associated with testing.

---------------------------------------------------------------------------

[[Page 24245]]

    As discussed in section III.E.1.(d) of this NOPR, DOE proposes to 
include a CVP in its enforcement regulations to validate whether 
override of modulating components in regulatory tests for variable-
capacity compressor systems is consistent with native control 
operation. The proposed CVP for variable-capacity compressor systems in 
appendix I of AHRI 210/240-202X is not mandatory for manufacturers to 
perform, therefore, the proposed inclusion of this provision in DOE's 
enforcement regulations clarifies the approach DOE would follow for 
potential enforcement testing. To the extent that a manufacturer has 
not already verified the appropriateness of the fixed performance 
during regulatory tests as compared to native control operation (i.e., 
the system may currently be improperly certified), a manufacturer may 
need to adjust fixed-speed overrides used in regulatory tests in 
accordance with the proposed CVP and subsequently re-run the regulatory 
tests. However, having no strong evidence to the contrary, DOE expects 
that current variable-capacity certifications are generally consistent 
with system performance. Thus, DOE concludes that any such cost to 
verify performance and potentially retest is negligible.
    As explained in section III.E.2 of this NOPR, a new definition for 
CCHPs is introduced in AHRI 210/240-202X Draft, for which the 
H4full test (outdoor dry-bulb temperature of 5 [deg]F) will 
be mandatory, which is otherwise optional for CHPs. However, this test 
and claim of CCHP status is optional. Also, DOE anticipates that units 
that will certify as CCHPs are most likely to be already testing at the 
5 [deg]F condition, and hence no added costs or test burden are 
expected to be associated with them.
    The proposal for determination of cut-in and cut-out temperatures 
in DOE's enforcement provisions, as laid out in appendix J of the AHRI 
210/240-202X Draft, would not be required for manufacturer testing. 
Thus, it will not cause manufacturers to incur any additional costs or 
burden.
    As explained in section III.F.5 of this NOPR, AHRI 210/240-202X 
Draft introduced a definition for mandatory circulation systems. DOE is 
currently unaware of any CAC/HPs equipped with these systems, and they 
are anticipated to become more commonplace once A2L refrigerant 
regulations are enforced. CAC/HPs equipped with mandatory circulation 
systems will need to have their cyclic degradation coefficients 
evaluated using the respective cyclic tests, which are otherwise 
optional. Since cyclic tests are already often conducted by 
manufacturers to improve upon the default cyclic degradation 
coefficients, and because it is unclear whether any systems having such 
mandatory circulation will be introduced, DOE considers that there will 
be no significant increase in cost or test burden associated with the 
requirement for CAC/HPs equipped with mandatory circulation systems to 
conduct cyclic tests.
    Issue 5: DOE requests comment on its tentative determination that 
the proposed amended appendix M1 would not require re-testing or result 
in any increase in test cost as compared to the existing appendix M1.
2. Appendix M2
    As explained previously, DOE proposes to establish new regulations 
at 10 CFR 430, subpart B, appendix M2 as follows: (1) incorporate by 
reference AHRI 1600-202X Draft, and relevant industry standards 
referenced in AHRI 1600-202X Draft (ANSI/ASHRAE 37-2009, ANSI/ASHRAE 
16-2016, and ANSI/ASHRAE 116-2010); and (2) establish provisions for 
determining SCORE and SHORE for CAC/HPs. Appendix M2 would not be 
required for testing until the compliance date of any future new 
standards for CAC/HPs based on the SCORE and SHORE metrics proposed in 
appendix M2. The proposed testing requirements in appendix M2 are those 
in AHRI 1600-202X Draft, which in turn references ANSI/ASHRAE 37-2009, 
ANSI/ASHRAE 16-2016, and ANSI/ASHRAE 116-2010.
    DOE has tentatively determined that the proposed amendments in 
appendix M2 would be representative of average use cycle, not be unduly 
burdensome for manufacturers to conduct, and not result in increased 
testing cost as compared to the current test procedure. The proposed 
revisions to the test procedure in appendix M2 for measuring EER2, 
SCORE, and SHORE per AHRI 1600-202X Draft would not increase third-
party laboratory testing costs per unit relative to the current DOE 
test procedure. DOE estimates the costs of physical testing, for the 
new metrics SCORE and SHORE to range from $10,800 to $19,800, same as 
that for appendix M1, depending on the configuration of the CAC/HP 
(e.g., single-stage, two-stage, variable-capacity). DOE has tentatively 
concluded that the proposed revisions to the test procedure in appendix 
M2 would change efficiency ratings for CAC/HPs--however, testing and 
recertification based on appendix M2 would not be required until DOE 
adopts any amended CAC/HP standards in terms of the new metrics in a 
future energy conservation standards rulemaking.
    As previously mentioned in this NOPR, the AHRI 1600-202X Draft 
introduces new cooling and heating performance metrics, SCORE and 
SHORE, as replacements for the current cooling, heating, and off-mode 
performance metrics, SEER2, HSPF2, and PW,OFF, used to 
determine the measured efficiency of CAC/HPs. Unlike SEER2 and HSPF2, 
these new metrics account for the off-mode power consumption of 
auxiliary components, including crankcase heaters and indoor fans 
utilizing constant circulation for both SCORE and SHORE, as well as 
base pan heaters for SHORE.\101\ The off-mode power consumption of 
auxiliary components is determined using appendix G of the AHRI 1600-
202X Draft. This appendix includes measurement of power for base pan 
heaters and constant circulation fans, which are not included in the 
current test procedure measurements to determine off-mode power. The 
measurements are otherwise identical to those required by the current 
test, although the calculations used to determine off-mode power are 
different. Measurements of base pan heater power and constant 
circulation power may require separate power measurement 
instrumentation to be applied for the base pan heater, and may require 
a brief power measurement test period for constant circulation, both 
test method additions which represent minor test burden increase and 
would be applicable only for a minority of models. Hence, adoption of 
the new cooling and heating metric would not result in significant 
increase in testing costs as compared to the current test procedure.
---------------------------------------------------------------------------

    \101\ As described in section III.F.1.a of this NOPR, the off-
mode power consumption definition in appendix M1 includes energy use 
for all operating modes not associated with times that the system is 
providing cooling or heating. Thus, off-mode in the context of the 
CAC/HP test procedure includes operating modes that would be 
interpreted as standby or active modes under IEC 62301.
---------------------------------------------------------------------------

    The other proposed amendments mainly affect calculations and, other 
than potentially imposing limits on airflow settings (item (e) in this 
paragraph), will not affect testing. The proposed amendments are (a) 
revising

[[Page 24246]]

the demand defrost credit for CHPs equipped with demand defrost 
systems; (b) accounting for the additional power use from supplementary 
heat during defrost by introducing defrost heat debit and the defrost 
overrun mode; (c) updating the building load lines and temperature bin 
hours for calculation of the new seasonal metrics SCORE and SHORE; (d) 
revising the default fan power coefficients for coil-only systems; and 
(e) imposing air flow limits to address inadequate dehumidification. 
Thus, DOE does not anticipate these additional amendments will cause 
any increased test procedure costs.
    Issue 6: DOE requests comment on its tentative understanding of the 
impact of the test procedure proposals in this NOPR, particularly 
regarding DOE's initial estimates of the cost impacts associated with 
the proposed appendix M2. DOE also requests comment on the cost of 
testing CAC/HPs in accordance with AHRI 1600-202X Draft compared to 
DOE's estimated appendix M2 testing costs for physical testing ranging 
from $10,800 to $18,000, which are unchanged from the appendix M1 
testing costs.

L. Compliance Date and Waivers

    EPCA prescribes that, if DOE amends a test procedure, all 
representations of energy efficiency and energy use, including those 
made on marketing materials and product labels, must be made in 
accordance with that amended test procedure, beginning 180 days after 
publication of such a test procedure final rule in the Federal 
Register. (42 U.S.C. 6293(c)(2)) To the extent the modified test 
procedure proposed in this document is required only for the evaluation 
and issuance of updated efficiency standards, use of the modified test 
procedure, if finalized, would not be required until the compliance 
date of updated standards. Section 8(e) of appendix A 10 CFR part 430 
subpart C.
    If DOE were to publish an amended test procedure, EPCA provides an 
allowance for individual manufacturers to petition DOE for an extension 
of the 180-day period if the manufacturer may experience undue hardship 
in meeting the deadline. (42 U.S.C. 6293(c)(3)) To receive such an 
extension, petitions must be filed with DOE no later than 60 days 
before the end of the 180-day period and must detail how the 
manufacturer will experience undue hardship. (Id.)
    Upon the compliance date of test procedure provisions of an amended 
test procedure, should DOE issue a such an amendment, any waivers that 
had been previously issued and are in effect that pertain to issues 
addressed by such provisions are terminated. 10 CFR 430.27(h)(3). 
Recipients of any such waivers would be required to test the products 
subject to the waiver according to the amended test procedure as of the 
compliance date of the amended test procedure. The amendments proposed 
in this document pertain to issues addressed by the interim waiver 
granted to Samsung HVAC America LLC (88 FR 36558, Case No. 2022-009). 
To the extent that such an interim waiver permit the petitioner to test 
according to an alternate test procedure to appendix M1, the interim 
waiver will terminate on the date the amendments to the appendix M1 
test procedure take effect (i.e., 180 days after publication of the 
test procedure final rule in the Federal Register).
    Notably, the amendments proposed in this document do not pertain to 
issues addressed by the interim waiver granted to Johnson Controls Inc. 
(``JCI'') (88 FR 72449, Case No. 2023-005). This interim waiver permits 
JCI to test certain basic models of CAC/HPs that use variable speed, 
oil-injected scroll compressors (``VSS systems'') with a 72-hour break-
in period, in lieu of the 20-hour break-in limit prescribed in appendix 
M1. (Id.) Because the 72-hour break-in period permitted to VSS systems 
listed in JCI's petition is unique to the CAC/HP market, DOE surmises 
that amendments to address this issue do not belong in either of the 
proposed Federal test procedures for CAC/HPs (i.e., appendix M1 or 
appendix M2). However, DOE notes that JCI may continue to request a 
waiver to extend the allowable break-in period for its VSS systems. To 
the extent the interim waiver permits JCI to test according to an 
alternate test procedure to appendix M1, the interim waiver will 
terminate on the date testing is required according to appendix M2, 
which will occur on the compliance date for updated efficiency 
standards. DOE notes that JCI may petition for another waiver at the 
time testing is required according to appendix M2.

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Orders 12866, 13563, and 14094

    Executive Order (``E.O.'') 12866, ``Regulatory Planning and 
Review,'' as supplemented and reaffirmed by E.O. 13563, ``Improving 
Regulation and Regulatory Review,'' 76 FR 3821 (Jan. 21, 2011) and 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 the preamble, this proposed 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 proposed regulatory action does not constitute a 
``significant regulatory action'' under section 3(f) of E.O. 12866. 
Accordingly, this action was not submitted to OIRA for review under 
E.O. 12866.

B. Review Under the Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires 
preparation of an initial regulatory flexibility analysis (``IRFA'') 
for any rule that by law must be proposed for public comment, unless 
the agency certifies that the rule, if promulgated, will not have a 
significant economic impact on a substantial number of small entities. 
As required by Executive Order 13272, ``Proper Consideration of Small 
Entities in Agency Rulemaking,'' 67 FR 53461 (August 16, 2002), DOE 
published procedures and policies on February 19,

[[Page 24247]]

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 proposed rule under the provisions 
of the Regulatory Flexibility Act and the procedures and policies 
published on February 19, 2003. The following sections detail DOE's 
IRFA for this test procedure proposed rulemaking.
1. Description of Reasons Why Action Is Being Considered
    DOE proposes to update the current Federal test procedure for CAC/
HPs at appendix M1 consistent with the most recent draft version of the 
relevant industry consensus test procedure, AHRI 210/240-202X Draft. 
DOE is also proposing a new Federal test procedure at 10 CFR part 430, 
subpart B, appendix M2, consistent with the draft version of the 
industry consensus test procedure, AHRI 1600-202X Draft. Appendix M2 
would not be effective until new standards are established for CAC/HPs 
that rely on metrics present in appendix M2. In this NOPR, DOE is 
proposing amendments to the test procedure for CAC/HPs in satisfaction 
of the 7-year review statutory requirement specified in EPCA. (42 
U.S.C. 6292(a)(3) and 6293(b)(1)(A))
2. Objectives of, and Legal Basis for, Rule
    Under 42 U.S.C. 6293, EPCA sets forth the criteria and procedures 
DOE must follow when prescribing or amending test procedures for 
covered products. EPCA requires that any test procedures prescribed or 
amended under this section be reasonably designed to produce test 
results which measure energy efficiency, energy use, or estimated 
annual operating cost of a covered product during a representative 
average use cycle or period of use and not be unduly burdensome to 
conduct. (42 U.S.C. 6293(b)(3))
    EPCA also requires that, at least once every 7 years, DOE review 
test procedures for all type of covered products, including CAC/HPs, to 
determine whether amended test procedures would more accurately or 
fully comply with the requirements that the test procedures are: (1) 
reasonably designed to produce test results which reflect energy 
efficiency, energy use, and estimated operating costs during a 
representative average use cycle or period of use; and (2) not unduly 
burdensome to conduct. (42 U.S.C. 6293(b)(1)(A))
    DOE is publishing this NOPR proposing amendments to the test 
procedure for CAC/HPs in satisfaction of the aforementioned obligations 
under EPCA.
3. Description and Estimated Number of Small Entities Regulated
    For manufacturers of CAC/HPs, the Small Business Administration 
(``SBA'') has set a size threshold, which defines those entities 
classified as ``small businesses'' for the purposes of the statute. DOE 
used the SBA's small business size standards to determine whether any 
small entities would be subject to the requirements of the rule. (See 
13 CFR part 121.) The equipment covered by this rule is classified 
under North American Industry Classification System (``NAICS'') code 
333415,\102\ ``Air-Conditioning and Warm Air Heating Equipment and 
Commercial and Industrial Refrigeration Equipment Manufacturing.'' The 
SBA sets a threshold of 1,250 employees or fewer for an entity to be 
considered as a small business for this category.
---------------------------------------------------------------------------

    \102\ 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 Sept. 22, 2023).
---------------------------------------------------------------------------

    DOE used publicly available information to identify potential small 
businesses that manufacture CAC/HPs. DOE identified manufacturers using 
DOE's Compliance Certification Database (``CCD'') \103\ and the prior 
CAC/HP rulemakings. DOE used the publicly available information and 
subscription-based market research tools (e.g., reports from Dun & 
Bradstreet) \104\ to identify 22 original equipment manufacturers 
(``OEMs'') of the covered equipment. Of the 22 OEMs, DOE identified 
five domestic manufacturers of CAC/HPs.
---------------------------------------------------------------------------

    \103\ DOE's Compliance Certification Database is available at 
www.regulations.doe.gov/ccms (last accessed Sept. 19, 2023).
    \104\ Dun & Bradstreet login available at https://app.dnbhoovers.com.
---------------------------------------------------------------------------

    DOE expects manufacturers that certify to AHRI Directory of 
Certified Product Performance (``AHRI Directory'') \105\ to have 
different potential regulatory costs from manufacturers that do not 
certify to the AHRI Directory. All five small OEMs certify their CAC/
HPs to the AHRI Directory.
---------------------------------------------------------------------------

    \105\ The AHRI Directory of Certified Product Performance is 
available at www.ahridirectory.org.
---------------------------------------------------------------------------

4. Description and Estimate of Compliance Requirements
    This NOPR proposes to adopt updated industry test standards for 
CAC/HPs. DOE proposes to update the current Federal test procedure for 
CAC/HPs at appendix M1, consistent with the most recent draft version 
of the relevant industry consensus test procedure, AHRI 210/240-202X 
Draft. DOE is also proposing a new Federal test procedure at 10 CFR 
part 430, subpart B, appendix M2, consistent with the draft version of 
the industry consensus test procedure, AHRI 1600-202X Draft. More 
specific amendments to the DOE test procedure are summarized in the 
following subsections.
(a) Cost and Compliance Associated With Appendix M1
    In appendix M1, DOE proposes to incorporate by reference AHRI 210/
240-202X Draft for CAC/HPs and to amend certain provisions for 
representations and enforcement in 10 CFR part 429, consistent with the 
changes proposed to the test procedure. The proposed revisions to 
appendix M1 would retain the current efficiency metrics--EER2, SEER2, 
and HSPF2. The proposed testing requirements in appendix M1 are 
generally consistent with those in AHRI 210/240-202X Draft, which in 
turn references ANSI/ASHRAE 37-2009, ANSI/ASHRAE 16-2016, and ASHRAE 
116-2010. This proposed revision to the test procedure in appendix M1 
for measuring EER2, SEER2, and HSPF2 would not increase third-party 
laboratory testing costs per unit relative to the current DOE test 
procedure. The proposed CVP'' for variable-capacity compressor systems 
in appendix I of AHRI 210/240-202X is not mandatory for manufacturers 
to perform, and DOE considers these developmental costs to be 
negligible and not burdensome to manufacturers. The H4full 
test (outdoor dry-bulb temperature of 5 [deg]F) will be mandatory, but 
DOE anticipates no added costs as units that will certify as CCHPs are 
likely currently testing at the 5 [deg]F condition. The proposal for 
determination of cut-in and cut-out temperatures in appendix J of the 
AHRI 210/240-202X Draft would be included in DOE's enforcement 
provisions and would not be mandatory for manufacturer testing, and 
thus manufacturers will not incur additional costs. Additionally, CAC/
HPs equipped with mandatory circulation systems will have their cyclic 
degradation coefficients evaluated using respective cyclic tests, but 
DOE anticipates no added costs to manufacturers since cyclic tests are 
already often conducted on CAC/HPs (regardless of whether they are 
equipped with a mandatory constant circulation system) to improve the 
default cyclic degradation coefficients.
    DOE has tentatively concluded that the proposed revisions to the 
test procedure in appendix M1 would not change efficiency ratings for 
CAC/HPs,

[[Page 24248]]

and therefore would not require retesting or redesign solely as a 
result of DOE's adoption of this proposed amendment to the DOE test 
procedure, if made final.\106\ Further, the proposed test procedure in 
appendix M1 would not increase third-part laboratory testing costs per 
unit; DOE estimates current costs for physical testing to range from 
$10,800 to $19,800, depending on the configuration of the CAC/HP 
(single-stage, two-stage, variable-capacity). Therefore, DOE does not 
expect that the test procedure amendments in appendix M1 would result 
in manufacturers, including small manufacturers, incurring additional 
testing costs.
---------------------------------------------------------------------------

    \106\ Manufacturers are not required to perform laboratory 
testing on all basic models. In accordance with 10 CFR 429.16, CAC/
HP manufacturers may elect to use AEDMs. 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 to reduce the burden and cost 
associated with testing.
---------------------------------------------------------------------------

(b) Cost and Compliance Associated With Appendix M2
    In appendix M2, DOE proposes to establish a new test procedure that 
references the draft industry test procedure, AHRI 1600-202X Draft, for 
measuring new efficiency metrics, SCORE and SHORE. Appendix M2 would 
not be effective until new standards are established for CAC/HPs that 
rely on metrics present in appendix M2, should DOE adopt such 
standards. The proposed testing requirements in appendix M2 are 
generally consistent with those in AHRI 1600-202X Draft, which in turn 
references ANSI/ASHRAE 37-2009, ANSI/ASHRAE 16-2016, and ASHRAE 116-
2010. This proposed revision to the test procedure in appendix M2 for 
measuring EER2, SCORE, and SHORE would not increase third-party 
laboratory testing costs per unit relative to the current DOE test 
procedure. The standby and off-mode power consumption of auxiliary 
components is determined using appendix G of the AHRI 1600-202X Draft 
and does not differ substantially from the process to determine off-
mode power from the current version of appendix M1, in section 3.13. 
The adoption of the new cooling and heating metric would not result in 
increased testing costs as compared to the current test procedure. 
Other proposed amendments will not affect testing cost, which include 
(a) building load lines and temperature bin hours for calculation of 
SCORE and SHORE, (b) default fan power coefficients for coil-only 
systems, and (c) air flow limits to address inadequate 
dehumidification.
    The testing cost will not increase with appendix M2. DOE estimates 
the costs of physical testing for the new metrics SCORE and SHORE to 
range from $10,800 to $18,000, depending on the configuration of the 
CAC/HP (single-stage, two-stage, variable-capacity). Additionally, DOE 
allows the use of AEDMs in lieu of physically testing all basic models. 
The use of an AEDM is less costly than physical testing of CAC/HP 
models; DOE estimates the cost to develop an AEDM to be $16,860 per 
AEDM for a basic model, which includes the cost of physical testing 
done at a third-party laboratory to validate the AEDM.\107\ The 
development of the AEDM would reduce the need for physical testing on 
the part of manufacturers. Once the AEDM is developed, DOE estimates 
that it would take 5 minutes of an engineer's time \108\ to determine 
efficiency for each individual model within a basic model using the 
AEDM.
---------------------------------------------------------------------------

    \107\ AEDM = physical testing cost + (time to develop AEDM * 
engineering technician wage) = $14,400 + (60 hours * $41/hour).
    \108\ DOE estimates a fully-burdened wage rate of $41 per hour 
for an engineering technician based on Bureau of Labor Statistics 
median wage data for mechanical engineering technicians and benefits 
data for the private sector.
---------------------------------------------------------------------------

    DOE understands all manufacturers currently certifying in the AHRI 
Directory (including small businesses) will be testing their models in 
accordance with AHRI 1600-202X Draft, the industry test procedure DOE 
is proposing to reference at appendix M2. As stated, testing and 
certification of the SCORE and SHORE metrics will not be required until 
the compliance date of any future energy conservation standards based 
on these metrics; however, DOE anticipates manufacturers will need to 
re-test their models to rate them in terms of the SCORE and SHORE 
metrics to comply with the AHRI certification program, and the re-
rating will occur prior to a future energy conservation standards 
rulemaking. As a result, DOE has tentatively determined that the 
proposed test procedure amendments would not add any additional testing 
burden to manufacturers. Therefore, the proposed test procedure 
amendments in appendix M2 would not add any additional testing burden 
to the five small domestic manufacturers who certify in the AHRI 
database.
    Issue 7: DOE requests comment on the number of small business OEMs 
of CAC/HPs, their participation in the AHRI Directory, and associated 
compliance costs.
5. Duplication, Overlap, and Conflict With Other Rules and Regulations
    DOE is not aware of any rules or regulations that duplicate, 
overlap, or conflict with the rule being considered.
6. Significant Alternatives to the Rule
    DOE proposes to amend the CAC/HPs test procedure in reference to 
industry standards in both appendices M1 and M2. DOE proposes to 
incorporate by reference AHRI 210/240-202X Draft and the subsequent 
relevant standards it references (ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-
2009, and ASHRAE 116-2010) as the basis for the updated appendix M1 
test procedure. Similarly, DOE proposes to incorporate by reference 
AHRI 1600-202X Draft and the subsequent relevant standards it 
references (ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-
2010) as the basis for the new appendix M2 test procedure. DOE 
considered alternative test methods and modifications to the proposed 
test procedures in appendices M1 and M2 for CAC/HPs. However, 
alternatives deviating from the industry standard would burden 
manufacturers with additional costs for separate test procedures. DOE 
has tentatively determined that there are no better alternatives than 
the proposed test procedures, in terms of both meeting the agency's 
objectives and reducing burden on manufacturers. Adoption of 
alternatives that do not incorporate the consensus industry test 
procedures would increase testing costs on small manufacturers. 
Therefore, DOE is proposing to amend the existing DOE test procedure 
for CAC/HPs through incorporation by reference of AHRI 210/240-202X 
Draft and AHRI 1600-202X Draft with the additional modifications as 
discussed throughout this NOPR.
    In addition, individual manufacturers may petition for a waiver of 
the applicable test procedure. 10 CFR 431.401. Also, section 504 of the 
Department of Energy Organization Act, 42 U.S.C. 7194, provides 
authority for the Secretary to adjust a rule issued under EPCA in order 
to prevent ``special hardship, inequity, or unfair distribution of 
burdens'' that may be imposed on that manufacturer as a result of such 
rule. Manufacturers should refer to 10 CFR part 1003 for additional 
details.

C. Review Under the Paperwork Reduction Act of 1995

    Manufacturers of CAC/HPs must certify to DOE that their products 
comply with any applicable energy conservation standards. To certify

[[Page 24249]]

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 CAC/HPs. (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 proposing to amend the certification or reporting 
requirements for CAC/HPs in this NOPR. DOE will address certification 
requirements for CAC/HPs in a separate rulemaking for certification, 
compliance, and enforcement. 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 NOPR, DOE proposes test procedure amendments that will be 
used to develop and implement future energy conservation standards for 
CAC/HPs. DOE has determined that this proposed 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, subpart D, appendix A, 
sections 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 for agencies formulating and implementing 
policies or regulations that preempt State law or that have federalism 
implications. The Executive order requires agencies to examine the 
constitutional and statutory authority supporting any action that would 
limit the policymaking discretion of the States and to carefully assess 
the necessity for such actions. The Executive order also requires 
agencies to have an accountable process to ensure meaningful and timely 
input by State and local officials in the development of regulatory 
policies that have federalism implications. On March 14, 2000, DOE 
published a statement of policy describing the intergovernmental 
consultation process it will follow in the development of such 
regulations. 65 FR 13735. DOE has examined this proposed rule and has 
determined that it would not have a substantial direct effect on the 
States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government. EPCA governs and prescribes Federal 
preemption of State regulations as to energy conservation for the 
products that are the subject of this proposed rule. States can 
petition DOE for exemption from such preemption to the extent, and 
based on criteria, set forth in EPCA. (42 U.S.C. 6297(d)) No further 
action is required by Executive Order 13132.

F. Review Under Executive Order 12988

    Regarding the review of existing regulations and the promulgation 
of new regulations, section 3(a) of Executive Order 12988, ``Civil 
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal 
agencies the general duty to adhere to the following requirements: (1) 
eliminate drafting errors and ambiguity, (2) write regulations to 
minimize litigation, (3) provide a clear legal standard for affected 
conduct rather than a general standard, and (4) promote simplification 
and burden reduction. Section 3(b) of Executive Order 12988 
specifically requires that Executive agencies make every reasonable 
effort to ensure that the regulation (1) clearly specifies the 
preemptive effect, if any, (2) clearly specifies any effect on existing 
Federal law or regulation, (3) provides a clear legal standard for 
affected conduct while promoting simplification and burden reduction, 
(4) specifies the retroactive effect, if any, (5) adequately defines 
key terms, and (6) addresses other important issues affecting clarity 
and general draftsmanship under any guidelines issued by the Attorney 
General. Section 3(c) of Executive Order 12988 requires Executive 
agencies to review regulations in light of applicable standards in 
sections 3(a) and 3(b) to determine whether they are met or it is 
unreasonable to meet one or more of them. DOE has completed the 
required review and determined that, to the extent permitted by law, 
the proposed rule meets the relevant standards of Executive Order 
12988.

G. Review Under the Unfunded Mandates Reform Act of 1995

    Title II of the Unfunded Mandates Reform Act of 1995 (``UMRA'') 
requires each Federal agency to assess the effects of Federal 
regulatory actions on State, local, and Tribal governments and the 
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531). 
For a proposed regulatory action likely to result in a rule that may 
cause the expenditure by State, local, and Tribal governments, in the 
aggregate, or by the private sector of $100 million or more in any one 
year (adjusted annually for inflation), section 202 of UMRA requires a 
Federal agency to publish a written statement that estimates the 
resulting costs, benefits, and other effects on the national economy. 
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to 
develop an effective process to permit timely input by elected officers 
of State, local, and Tribal governments on a proposed ``significant 
intergovernmental mandate'' and requires an agency plan for giving 
notice and opportunity for timely input to potentially affected small 
governments before establishing any requirements that might 
significantly or uniquely affect small governments. On March 18, 1997, 
DOE published a statement of policy on its process for 
intergovernmental consultation under UMRA. 62 FR 12820; also available 
at www.energy.gov/gc/office-general-counsel. DOE examined this proposed 
rule according to UMRA and its statement of policy and determined that 
the rule contains neither an intergovernmental mandate, nor a mandate 
that may result in the expenditure of $100 million or more in any year, 
so these requirements do not apply.

H. Review Under the Treasury and General Government Appropriations Act, 
1999

    Section 654 of the Treasury and General Government Appropriations 
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family

[[Page 24250]]

Policymaking Assessment for any rule that may affect family well-being. 
This proposed rule would not have any impact on the autonomy or 
integrity of the family as an institution. Accordingly, DOE has 
concluded that it is not necessary to prepare a Family Policymaking 
Assessment.

I. Review Under Executive Order 12630

    DOE has determined, under Executive Order 12630, ``Governmental 
Actions and Interference with Constitutionally Protected Property 
Rights,'' 53 FR 8859 (March 18, 1988), that this proposed regulation 
would not result in any takings that might require compensation under 
the Fifth Amendment to the U.S. Constitution.

J. Review Under Treasury and General Government Appropriations Act, 
2001

    Section 515 of the Treasury and General Government Appropriations 
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most 
disseminations of information to the public under guidelines 
established by each agency pursuant to general guidelines issued by 
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and 
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). 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 proposed rule under the OMB and DOE guidelines and has 
concluded that it is consistent with applicable policies in those 
guidelines.

K. Review Under Executive Order 13211

    Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355 
(May 22, 2001), requires Federal agencies to prepare and submit to OMB, 
a Statement of Energy Effects for any proposed significant energy 
action. A ``significant energy action'' is defined as any action by an 
agency that promulgated or is expected to lead to promulgation of a 
final rule, and that (1) is a significant regulatory action under 
Executive Order 12866, or any successor order; and (2) is likely to 
have a significant adverse effect on the supply, distribution, or use 
of energy; or (3) is designated by the Administrator of OIRA as a 
significant energy action. For any proposed significant energy action, 
the agency must give a detailed statement of any adverse effects on 
energy supply, distribution, or use should the proposal be implemented, 
and of reasonable alternatives to the action and their expected 
benefits on energy supply, distribution, and use.
    The proposed regulatory action to amend the test procedure for 
measuring the energy efficiency of CAC/HPs is not a significant 
regulatory action under Executive Order 12866. Moreover, it would not 
have a significant adverse effect on the supply, distribution, or use 
of energy, nor has it been designated as a significant energy action by 
the Administrator of OIRA. Therefore, it is not a significant energy 
action, and, accordingly, DOE has not prepared a Statement of Energy 
Effects.

L. Review Under Section 32 of the Federal Energy Administration Act of 
1974

    Under section 301 of the Department of Energy Organization Act 
(Pub. L. 95-91; 42 U.S.C. 7101), DOE must comply with section 32 of the 
Federal Energy Administration Act of 1974, as amended by the Federal 
Energy Administration Authorization Act of 1977. (15 U.S.C. 788; 
``FEAA'') Section 32 essentially provides in relevant part that, where 
a proposed rule authorizes or requires use of commercial standards, the 
notice of proposed rulemaking must inform the public of the use and 
background of such standards. In addition, section 32(c) requires DOE 
to consult with the Attorney General and the Chairman of the Federal 
Trade Commission (``FTC'') concerning the impact of the commercial or 
industry standards on competition.
    The proposed modifications to the test procedure for CAC/HPs would 
specifically reference testing methods contained in certain sections of 
the following commercial standards: AHRI 210/240-202X Draft, ANSI/
ASHRAE 37-2009, ANSI/ASHRAE 16-2016, and ASHRAE 116-2010. DOE has 
evaluated these standards and is unable to conclude whether they fully 
comply with the requirements of section 32(b) of the FEAA (i.e., 
whether it was developed in a manner that fully provides for public 
participation, comment, and review). DOE will consult with both the 
Attorney General and the Chairman of the FTC concerning the impact of 
these test procedures on competition, prior to prescribing a final 
rule.

M. Description of Materials Incorporated by Reference

    In this NOPR, DOE proposes to incorporate by reference the 
following test standards:
    AHRI Standard 210/240-202X Draft. This test standard is an update 
to AHRI 210/240-2023 (2020), and is a draft industry test procedure for 
measuring the heating and cooling capacity and efficiency of unitary 
air-source air conditioners and heat pumps with capacities less than 
65,000 Btu/hour. The revised appendix M1 will be consistent with 
provisions in AHRI 210/240-202X Draft.
    AHRI 1600-202X Draft. This test standard is a major update to AHRI 
210/240-2023 (2020), and is a draft industry test procedure for 
measuring the heating and cooling capacity and efficiency of unitary 
air-source air conditioners and heat pumps with capacities less than 
65,000 Btu/hour, including new seasonal cooling and heating efficiency 
metrics, namely SCORE and SHORE. The new appendix M2 will be consistent 
with provisions in AHRI 1600-202X Draft.
    Copies of AHRI 210/240-202X Draft and AHRI 1600-202X Draft can be 
obtained from AHRI, 2311 Wilson Blvd., Suite 400, Arlington, VA 22201, 
(703) 524-8800, or found online at: www.ahrinet.org. Copies of the AHRI 
210/240-202X Draft and AHRI 1600-202X Draft are also available in the 
docket for this proposed rulemaking.
    If finalized versions of AHRI 210/240 and AHRI 1600 are not 
published before the test procedure final rule, or if there are 
substantive changes between the drafts and published versions of the 
standards that are not supported by stakeholder comments in response to 
this NOPR, DOE may adopt the substance of the AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft or provide additional opportunity for comment 
on the final version of that industry consensus standard.
    ANSI/ASHRAE 37-2009. This test standard is an industry-accepted 
test procedure that provides a method of test for many categories of 
air conditioning and heating equipment.
    ANSI/ASHRAE 16-2016. This test standard is an industry-accepted 
test procedure that provides a method of test for room air 
conditioners, packaged terminal air conditioners, and packaged terminal 
heat pumps.
    ASHRAE 116-2010. This test standard is an industry-accepted test 
procedure that provides a method of test for electrically driven, 
residential air-cooled air conditioners and heat pumps with cooling 
capacity of 65,000 Btu/hr. and less.
    Copies of ANSI/ASHRAE 37-2009, ANSI/ASHRAE 16-2016 and ASHRAE 116-
2010 are available on ASHRAE's website at www.ashrae.org.

[[Page 24251]]

V. Public Participation

A. Participation in the Webinar

    The time and date of the webinar are listed in the DATES section at 
the beginning of this document. Webinar registration information, 
participant instructions, and information about the capabilities 
available to webinar participants will be published on DOE's website 
www1.eere.energy.gov/buildings/appliance_standards/standards.aspx?productid=48&action=viewlive. Participants are 
responsible for ensuring their systems are compatible with the webinar 
software.

B. Procedure for Submitting Prepared General Statements for 
Distribution

    Any person who has plans to present a prepared general statement 
may request that copies of his or her statement be made available at 
the public meeting. Such persons may submit requests, along with an 
advance electronic copy of their statement in PDF (preferred), 
Microsoft Word or Excel, WordPerfect, or text (ASCII) file format, to 
the appropriate address shown in the ADDRESSES section at the beginning 
of this document. The request and advance copy of statements must be 
received at least one week before the public meeting and are to be 
emailed. Please include a telephone number to enable DOE staff to make 
follow-up contact, if needed.

C. Conduct of the Public Meeting

    DOE will designate a DOE official to preside at the public meeting 
and may also use a professional facilitator to aid discussion. The 
meeting will not be a judicial or evidentiary-type public hearing, but 
DOE will conduct it in accordance with section 336 of EPCA. (42 U.S.C. 
6306) A court reporter will be present to record the proceedings and 
prepare a transcript. DOE reserves the right to schedule the order of 
presentations and to establish the procedures governing the conduct of 
the public meeting. There shall not be discussion of proprietary 
information, costs or prices, market share, or other commercial matters 
regulated by U.S. anti-trust laws. After the public meeting, interested 
parties may submit further comments on the proceedings, as well as on 
any aspect of the rulemaking, until the end of the comment period.
    The public meeting will be conducted in an informal conference 
style. DOE will present a general overview of the topics addressed in 
this proposed rulemaking, allow time for prepared general statements by 
participants, and encourage all interested parties to share their views 
on issues affecting this proposed rulemaking. Each participant will be 
allowed to make a general statement (within time limits determined by 
DOE), before the discussion of specific topics. DOE will allow, as time 
permits, other participants to comment briefly on any general 
statements.
    At the end of all prepared statements on a topic, DOE will permit 
participants to clarify their statements briefly. Participants should 
be prepared to answer questions by DOE and by other participants 
concerning these issues. DOE representatives may also ask questions of 
participants concerning other matters relevant to this proposed 
rulemaking. The official conducting the public meeting will accept 
additional comments or questions from those attending, as time permits. 
The presiding official will announce any further procedural rules or 
modification of the previous procedures that may be needed for the 
proper conduct of the public meeting.
    A transcript of the public meeting will be included in the docket, 
which can be viewed as described in the Docket section at the beginning 
of this document and will be accessible on the DOE website. In 
addition, any person may buy a copy of the transcript from the 
transcribing reporter.

D. Submission of Comments

    DOE will accept comments, data, and information regarding this 
proposed rule before or after the public meeting, but no later than the 
date provided in the DATES section at the beginning of this proposed 
rule.\109\ Interested parties may submit comments, data, and other 
information using any of the methods described in the ADDRESSES section 
at the beginning of this document.
---------------------------------------------------------------------------

    \109\ DOE has historically provided a 75-day comment period for 
test procedure NOPRs pursuant to the North American Free Trade 
Agreement, U.S.-Canada-Mexico (``NAFTA''), Dec. 17, 1992, 32 I.L.M. 
289 (1993); the North American Free Trade Agreement Implementation 
Act, Public Law 103-182, 107 Stat. 2057 (1993) (codified as amended 
at 10 U.S.C.A. 2576) (1993) (``NAFTA Implementation Act''); and 
Executive Order 12889, ``Implementation of the North American Free 
Trade Agreement,'' 58 FR 69681 (Dec. 30, 1993). However, on July 1, 
2020, the Agreement between the United States of America, the United 
Mexican States, and the United Canadian States (``USMCA''), Nov. 30, 
2018, 134 Stat. 11 (i.e., the successor to NAFTA), went into effect, 
and Congress's action in replacing NAFTA through the USMCA 
Implementation Act, 19 U.S.C. 4501 et seq. (2020), implies the 
repeal of E.O. 12889 and its 75-day comment period requirement for 
technical regulations. Thus, the controlling laws are EPCA and the 
USMCA Implementation Act. Consistent with EPCA's public comment 
period requirements for consumer products, the USMCA only requires a 
minimum comment period of 60 days. Consequently, DOE now provides a 
60-day public comment period for test procedure NOPRs.
---------------------------------------------------------------------------

    Submitting comments via www.regulations.gov. The 
www.regulations.gov web page will require you to provide your name and 
contact information. Your contact information will be viewable to DOE 
Building Technologies staff only. Your contact information will not be 
publicly viewable except for your first and last names, organization 
name (if any), and submitter representative name (if any). If your 
comment is not processed properly because of technical difficulties, 
DOE will use this information to contact you. If DOE cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, DOE may not be able to consider your comment.
    However, your contact information will be publicly viewable if you 
include it in the comment itself or in any documents attached to your 
comment. Any information that you do not want to be publicly viewable 
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submitted. For information on submitting CBI, see the Confidential 
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    DOE processes submissions made through www.regulations.gov before 
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documents. Instead, provide your

[[Page 24252]]

contact information in a cover letter. Include your first and last 
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The cover letter will not be publicly viewable as long as it does not 
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    Include contact information each time you submit comments, data, 
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    Campaign form letters. Please submit campaign form letters by the 
originating organization in batches of between 50 to 500 form letters 
per PDF or as one form letter with a list of supporters' names compiled 
into one or more PDFs. This reduces comment processing and posting 
time.
    Confidential Business Information. Pursuant to 10 CFR 1004.11, any 
person submitting information that he or she believes to be 
confidential and exempt by law from public disclosure should submit via 
email two well-marked copies: one copy of the document marked 
``confidential'' including all the information believed to be 
confidential, and one copy of the document marked ``non-confidential'' 
with the information believed to be confidential deleted. DOE will make 
its own determination about the confidential status of the information 
and treat it according to its determination.
    It is DOE's policy that all comments may be included in the public 
docket, without change and as received, including any personal 
information provided in the comments (except information deemed to be 
exempt from public disclosure).

E. Issues on Which DOE Seeks Comment

    Although DOE welcomes comments on any aspect of this proposal, DOE 
is particularly interested in receiving comments and views of 
interested parties concerning the following issues:
    Issue 1: DOE requests feedback on its proposal to revise appendix 
M1 by making it consistent with the latest version of AHRI 210/240-202X 
Draft, for measuring the existing metrics, SEER2 and HSPF2.
    Issue 2: DOE requests feedback on its proposal to establish a new 
appendix M2, to be consistent with the latest version of AHRI 1600-202X 
Draft, and to adopt the SCORE and SHORE metrics as determined under 
AHRI 1600-202X Draft in appendix M2 of the Federal test procedure for 
CAC/HPs.
    Issue 3: DOE requests comment on its proposal to extend testing 
flexibility to P1 (off-mode power in shoulder season) and 
P2 (off-mode power in heating season) when determining SCORE 
and SHORE.
    Issue 4: DOE requests comment on its proposals related to 
enforcement provisions when conducting the CVP.
    Issue 5: DOE requests comment on its tentative understanding of the 
impact of the test procedure proposals in this NOPR, particularly 
regarding DOE's initial estimates of the cost impacts associated with 
the revised appendix M1.
    Issue 6: DOE requests comment on its tentative understanding of the 
impact of the test procedure proposals in this NOPR, particularly 
regarding DOE's initial estimates of the cost impacts associated with 
the proposed appendix M2. DOE also requests comment on the cost of 
testing CAC/HPs in accordance with AHRI 1600-202X Draft compared to 
DOE's estimated appendix M2 testing costs for physical testing ranging 
from $10,800 to $18,000, which are unchanged from the appendix M1 
testing costs.
    Issue 7: DOE requests comment on the number of small business OEMs 
of CAC/HPs and their participation in the AHRI Directory.
    Additionally, DOE welcomes comments on other issues relevant to the 
conduct of this rulemaking that may not specifically be identified in 
this document.

VI. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this notice of 
proposed rulemaking and request for comment.

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 430

    Administrative practice and procedure, Confidential business 
information, Energy conservation, Household appliances, Imports, 
Incorporation by reference, Intergovernmental relations, Small 
businesses.

Signing Authority

    This document of the Department of Energy was signed on February 
27, 2024, 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 March 1, 2024.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.

    For the reasons stated in the preamble, DOE is proposing to amend 
parts 429 and 430 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)(2) through (c)(7) as paragraphs (c)(3) 
through (c)(8); and
0
b. Adding new paragraphs (c)(2) and (c)(9).
    The additions read as follows:


Sec.  429.4  Materials incorporated by reference.

* * * * *
    (c) * * *
    (2) AHRI Standard 210/240-202X, 202X Standard for Performance 
Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment, 
[version

[[Page 24253]]

and date TBD]; IBR approved for Sec.  429.134.
* * * * *
    (9) AHRI 1600-202X, 202X Standard for Performance Rating of Unitary 
Air-Conditioning & Air-Source Heat Pump Equipment, [version and date 
TBD]; IBR approved for Sec.  429.134.
* * * * *
0
3. Amend Sec.  429.16 by revising paragraphs (a)(1), (2), and (3)(i), 
(b)(2), and (3)(ii), (c)(1)(i)(B), (c)(1)(ii), (c)(3), (d)(2), and (f) 
to read as follows:


Sec.  429.16  Central air conditioners and central air conditioning 
heat pumps.

    (a) * * *
    (1) Required represented values. Determine the represented values 
(including as applicable, SEER2, EER2, HSPF2, PW,OFF, SCORE, 
SHORE, cooling capacity, and heating capacity) for the individual 
models/combinations (or ``tested combinations'') specified in the 
following table.

                       Table 1 to Paragraph (a)(1)
------------------------------------------------------------------------
                                    Equipment       Required represented
          Category                 subcategory             values
------------------------------------------------------------------------
Single-Package Unit.........  Single-Package Air    Every individual
                               Conditioner (AC)      model distributed
                               (including space-     in commerce.
                               constrained).
                              Single-Package Heat   Every individual
                               Pump (HP)             model distributed
                               (including space-     in commerce.
                               constrained).
Outdoor Unit and Indoor Unit  Single-Split-System   Every individual
 (Distributed in Commerce by   AC with Single-       combination
 Outdoor Unit Manufacturer     Stage or Two-Stage    distributed in
 (OUM)).                       Compressor            commerce. Each
                               (including Space-     model of outdoor
                               Constrained and       unit must include a
                               Small-Duct, High      represented value
                               Velocity Systems      for at least one
                               (SDHV)).              coil-only
                                                     individual
                                                     combination that is
                                                     distributed in
                                                     commerce and which
                                                     is representative
                                                     of the least
                                                     efficient
                                                     combination
                                                     distributed in
                                                     commerce with that
                                                     particular model of
                                                     outdoor unit. For
                                                     that particular
                                                     model of outdoor
                                                     unit, additional
                                                     represented values
                                                     for coil-only and
                                                     blower-coil
                                                     individual
                                                     combinations are
                                                     allowed, if
                                                     distributed in
                                                     commerce.
                              Single-Split System   Every individual
                               AC with Other Than    combination
                               Single-Stage or Two-  distributed in
                               Stage Compressor      commerce, including
                               (including Space-     all coil-only and
                               Constrained and       blower-coil
                               SDHV).                combinations.
                              Single-Split-System   Every individual
                               HP (including Space-  combination
                               Constrained and       distributed in
                               SDHV).                commerce.
                              Multi-Split, Multi-   For each model of
                               Circuit, or Multi-    outdoor unit, at a
                               Head Mini-Split       minimum, a non-
                               Split System--non-    ducted ``tested
                               SDHV (including       combination.'' For
                               Space-Constrained).   any model of
                                                     outdoor unit also
                                                     sold with models of
                                                     ducted indoor
                                                     units, a ducted
                                                     ``tested
                                                     combination.'' The
                                                     ducted ``tested
                                                     combination'' must
                                                     comprise the
                                                     highest static
                                                     variety of ducted
                                                     indoor unit
                                                     distributed in
                                                     commerce (i.e.,
                                                     conventional, mid-
                                                     static, or low-
                                                     static). Additional
                                                     representations are
                                                     allowed, as
                                                     described in
                                                     paragraphs
                                                     (c)(3)(i) and (ii)
                                                     of this section,
                                                     respectively.
                              Multi-Split, Multi-   For each model of
                               Circuit, or Multi-    outdoor unit, an
                               Head Mini-Split       SDHV ``tested
                               Split System--SDHV.   combination.''
                                                     Additional
                                                     representations are
                                                     allowed, as
                                                     described in
                                                     paragraph
                                                     (c)(3)(iii) of this
                                                     section.
Indoor Unit Only Distributed  Single-Split-System   Every individual
 in Commerce by Independent    Air Conditioner       combination
 Coil Manufacturer (ICM).      (including Space-     distributed in
                               Constrained and       commerce.
                               SDHV).
                              Single-Split-System
                               Heat Pump
                               (including Space-
                               Constrained and
                               SDHV).
                              Multi-Split, Multi-   For a model of
                               Circuit, or Multi-    indoor unit within
                               Head Mini-Split       each basic model,
                               Split System--SDHV.   an SDHV ``tested
                                                     combination.''
                                                     Additional
                                                     representations are
                                                     allowed, as
                                                     described in
                                                     paragraph
                                                     (c)(3)(iii) of this
                                                     section.
---------------------------------------------------
Outdoor Unit with no Match........................  Every model of
                                                     outdoor unit
                                                     distributed in
                                                     commerce (tested
                                                     with a model of
                                                     coil-only indoor
                                                     unit as specified
                                                     in paragraph
                                                     (b)(2)(i) of this
                                                     section.
------------------------------------------------------------------------

    (2) PW,OFF. Represented values of PW,OFF are only 
required when determining represented values in accordance with 10 CFR 
part 430, subpart B, appendix M1. If individual models of single-
package systems or individual combinations (or ``tested combinations'') 
of split systems that are otherwise identical are offered with multiple 
options for off mode-related components, determine the represented 
value for the individual model/combination with the crankcase heater 
and controls that are the most consumptive. A manufacturer may also 
determine represented values for individual models/combinations with 
less consumptive off mode options; however, all such options must be 
identified with different model numbers for single-package systems or 
for outdoor units (in the case of split systems).
    (3) Refrigerants. (i) If a model of outdoor unit (used in a single-
split, multi-split, multi-circuit, multi-head mini-split, and/or 
outdoor unit with no match system) is distributed in commerce and 
approved for use with multiple refrigerants, a manufacturer must 
determine all represented values for that model using each refrigerant 
that can be used in an individual combination of the basic model 
(including outdoor units with no match

[[Page 24254]]

or ``tested combinations''). This requirement may apply across the 
listed categories in the table in paragraph (a)(1) of this section. A 
refrigerant is considered approved for use if it is listed on the 
nameplate of the outdoor unit.
* * * * *
    (b) * * *
    (2) * * *
    (i) The table identifies the minimum testing requirements for each 
basic model that includes multiple individual models/combinations; if a 
basic model spans multiple categories or subcategories listed in the 
table, multiple testing requirements apply. For each basic model that 
includes only one individual model/combination, test that individual 
model/combination.

                                         Table 2 to Paragraph (b)(2)(i)
----------------------------------------------------------------------------------------------------------------
             Category                Equipment subcategory           Must test:                   With:
----------------------------------------------------------------------------------------------------------------
Single-Package Unit..............  Single-Package AC          The individual model      N/A.
                                    (including Space-          with the lowest
                                    Constrained).              seasonal energy
                                   Single-Package HP           efficiency ratio 2
                                    (including Space-          (SEER2) (when testing
                                    Constrained).              in accordance with
                                                               appendix M1 to subpart
                                                               B of part 430) or SCORE
                                                               (when testing in
                                                               accordance with
                                                               appendix M2 to subpart
                                                               B of part 430).
Outdoor Unit and Indoor Unit       Single-Split-System AC     The model of outdoor      A model of coil-only
 (Distributed in Commerce by OUM).  with Single-Stage or Two-  unit.                     indoor unit.
                                    Stage Compressor
                                    (including Space-
                                    Constrained and Small-
                                    Duct, High Velocity
                                    Systems (SDHV)).
                                   Single-Split-System HP     The model of outdoor      A model of indoor unit.
                                    with Single-Stage or Two-  unit.
                                    Stage Compressor
                                    (including Space-
                                    Constrained and SDHV).
                                   Single-Split System AC or  The model of outdoor      A model of coil-only
                                    HP with Other Than         unit.                     indoor unit.
                                    Single-Stage or Two-
                                    Stage Compressor having
                                    a coil-only individual
                                    combination (including
                                    Space-Constrained and
                                    SDHV).
                                   Single-Split System AC or  The model of outdoor      A model of indoor unit.
                                    HP with Other Than         unit.
                                    Single-Stage or Two-
                                    Stage Compressor without
                                    a coil-only individual
                                    combination (including
                                    Space-Constrained and
                                    SDHV).
                                   Multi-Split, Multi-        The model of outdoor      At a minimum, a ``tested
                                    Circuit, or Multi-Head     unit.                     combination'' composed
                                    Mini-Split Split System--                            entirely of non-ducted
                                    non-SDHV (including                                  indoor units. For any
                                    Space-Constrained).                                  models of outdoor units
                                                                                         also sold with models
                                                                                         of ducted indoor units,
                                                                                         test a second ``tested
                                                                                         combination'' composed
                                                                                         entirely of ducted
                                                                                         indoor units (in
                                                                                         addition to the non-
                                                                                         ducted combination).
                                                                                         The ducted ``tested
                                                                                         combination'' must
                                                                                         comprise the highest
                                                                                         static variety of
                                                                                         ducted indoor unit
                                                                                         distributed in commerce
                                                                                         (i.e., conventional,
                                                                                         mid-static, or low-
                                                                                         static).
                                   Multi-Split, Multi-        The model of outdoor      A ``tested combination''
                                    Circuit, or Multi-Head     unit.                     composed entirely of
                                    Mini-Split Split System--                            SDHV indoor units.
                                    SDHV.
Indoor Unit Only (Distributed in   Single-Split-System Air    A model of indoor unit..  The least efficient
 Commerce by ICM).                  Conditioner (including                               model of outdoor unit
                                    Space-Constrained and                                with which it will be
                                    SDHV).                                               paired where the least
                                                                                         efficient model of
                                                                                         outdoor unit is the
                                                                                         model of outdoor unit
                                                                                         in the lowest SEER2
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430) or SCORE
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M2 to subpart B of part
                                                                                         430) as certified by
                                                                                         the OUM. If there are
                                                                                         multiple models of
                                                                                         outdoor unit with the
                                                                                         same lowest SEER2 (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430) or SCORE (when
                                                                                         testing under appendix
                                                                                         M2 to subpart B of part
                                                                                         430) represented value,
                                                                                         the ICM may select one
                                                                                         for testing purposes.

[[Page 24255]]

 
                                   Single-Split-System Heat   Nothing, as long as an    ........................
                                    Pump (including Space-     equivalent air
                                    Constrained and SDHV).     conditioner basic model
                                                               has been tested. If an
                                                               equivalent air
                                                               conditioner basic model
                                                               has not been tested,
                                                               must test a model of
                                                               indoor unit.
                                   Multi-Split, Multi-        A model of indoor unit..  A ``tested combination''
                                    Circuit, or Multi-Head                               composed entirely of
                                    Mini-Split Split System--                            SDHV indoor units,
                                    SDHV.                                                where the outdoor unit
                                                                                         is the least efficient
                                                                                         model of outdoor unit
                                                                                         with which the SDHV
                                                                                         indoor unit will be
                                                                                         paired. The least
                                                                                         efficient model of
                                                                                         outdoor unit is the
                                                                                         model of outdoor unit
                                                                                         in the lowest SEER2
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430) or SCORE
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M2 to subpart B of part
                                                                                         430) as certified by
                                                                                         the OUM. If there are
                                                                                         multiple models of
                                                                                         outdoor unit with the
                                                                                         same lowest SEER2
                                                                                         represented value (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430) or SCORE
                                                                                         represented value (when
                                                                                         testing under appendix
                                                                                         M2 to subpart B of part
                                                                                         430), the ICM may
                                                                                         select one for testing
                                                                                         purposes.
Outdoor Unit with No Match.......  .........................  The model of outdoor      A model of coil-only
                                                               unit.                     indoor unit meeting the
                                                                                         requirements of section
                                                                                         4 of appendix M1 (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430); or meeting the
                                                                                         requirements of section
                                                                                         3 of appendix M2 (when
                                                                                         testing under appendix
                                                                                         M2 to subpart B of part
                                                                                         430).
----------------------------------------------------------------------------------------------------------------

    (ii) When testing in accordance with appendix M1 to subpart B of 
part 430, each individual model/combination (or ``tested combination'') 
identified in paragraph (b)(2)(i) of this section is not required to be 
tested for PW,OFF. Instead, at a minimum, among individual 
models/combinations with similar off-mode construction (even spanning 
different models of outdoor units), a manufacturer must test at least 
one individual model/combination for PW,OFF.
    (iii) When testing in accordance with appendix M2 to subpart B of 
part 430 and determining SCORE and SHORE, each individual model/
combination (or ``tested combination'') identified in paragraph 
(b)(2)(i) of this section is not required to be tested for values of 
P1 (off-mode power in shoulder season) and P2 
(off-mode power in heating Season). Instead, at a minimum, among 
individual models/combinations with similar off-mode construction (even 
spanning different models of outdoor units), a manufacturer must test 
at least one individual model/combination, for which P1 and 
P2 are the most consumptive.
    (3) * * *
    (ii) SEER2, EER2, HSPF2, SCORE and SHORE. Any represented value of 
the energy efficiency or other measure of energy consumption for which 
consumers would favor higher values shall be less than or equal to the 
lower of:
    (A) The mean of the sample, where:
    [GRAPHIC] [TIFF OMITTED] TP05AP24.054
    
    and, x is the sample mean; n is the number of samples; and 
xi is the ith sample; or,
    (B) The lower 90 percent confidence limit (LCL) of the true mean 
divided by 0.95, where:
[GRAPHIC] [TIFF OMITTED] TP05AP24.055

    And x is the sample mean; s is the sample standard deviation; n is 
the number of samples; and t0.90 is the t statistic for a 90 
percent one-tailed confidence interval with n - 1 degrees of freedom 
(from appendix D). Round represented values of EER2, SEER2, HSPF2, 
SCORE and SHORE to the nearest 0.05.
* * * * *
    (c) * * *
    (1) * * *
    (i) * * *
    (B) The represented values of the measures of energy efficiency or 
energy consumption through the application of an AEDM in accordance 
with paragraph (d) of this section and Sec.  429.70. An AEDM may only 
be used to determine represented values for individual models or 
combinations in a basic model (or separate approved refrigerants within 
an individual combination) other than the individual model or 
combination(s) required for mandatory testing under paragraph (b)(2) of 
this section.
    (ii) When testing in accordance with appendix M1 to subpart B of 
part 430, for every individual model/combination within a basic model 
tested pursuant to paragraph (b)(2) of this section, but for which 
Pw,off testing was not conducted, the represented value of 
Pw,off may be assigned through, either:

[[Page 24256]]

    (A) The testing result from an individual model/combination of 
similar off-mode construction; or
    (B) The application of an AEDM in accordance with paragraph (d) of 
this section and Sec.  429.70.
* * * * *
    (3) For multi-split systems, multi-circuit systems, and multi-head 
mini-split systems. The following applies:
    (i) When testing in accordance with appendix M1 to subpart B of 
part 430, or appendix M2 to subpart B of part 430, for basic models 
that include additional varieties of ducted indoor units (i.e., 
conventional, low-static, or mid-static) other than the one for which 
representation is required in paragraph (a)(1) of this section, if a 
manufacturer chooses to make a representation, the manufacturer must 
conduct testing of a tested combination according to the requirements 
in paragraph (b)(3) of this section.
    (ii) When testing in accordance with appendix M1 to subpart B of 
part 430, or appendix M2 to subpart B of part 430, for basic models 
that include mixed combinations of indoor units (any two kinds of non-
ducted, low-static, mid-static, and conventional ducted indoor units), 
the represented value for the mixed combination is the mean of the 
represented values for the individual component combinations as 
determined in accordance with paragraph (b)(3) of this section.
    (iii) When testing in accordance with appendix M1 to subpart B of 
part 430, or appendix M2 to subpart B of part 430, for basic models 
including mixed combinations of SDHV and another kind of indoor unit 
(any of non-ducted, low-static, mid-static, and conventional ducted), 
the represented value for the mixed SDHV/other combination is the mean 
of the represented values for the SDHV and other tested combination as 
determined in accordance with paragraph (b)(3) of this section.
    (iv) All other individual combinations of models of indoor units 
for the same model of outdoor unit for which the manufacturer chooses 
to make representations must be rated as separate basic models, and the 
provisions of paragraphs (b)(1) through (3) and (c)(3)(i) through (iii) 
of this section apply.
    (v) When testing in accordance with appendix M1 to subpart B of 
part 430, and with respect to Pw,off only, for every 
individual combination (or ``tested combination'') within a basic model 
tested pursuant to paragraph (b)(2) of this section, but for which 
Pw,off testing was not conducted, the representative values 
of Pw,off may be assigned through either:
    (A) The testing result from an individual model or combination of 
similar off-mode construction, or
    (B) Application of an AEDM in accordance with paragraph (d) of this 
section and Sec.  429.70.
    (d) * * *
    (2) Energy efficiency. Any represented value of the SEER2, EER2, 
HSPF2, SCORE, SHORE or other measure of energy efficiency of an 
individual model/combination for which consumers would favor higher 
values must be less than or equal to the output of the AEDM but no less 
than the standard.
* * * * *
    (f) Represented values for the Federal Trade Commission. Use the 
following represented value determinations to meet the requirements of 
the Federal Trade Commission.
    (1) Annual Operating Cost--Cooling. Determine the represented value 
of estimated annual operating cost for cooling-only units or the 
cooling portion of the estimated annual operating cost for air-source 
heat pumps that provide both heating and cooling, as follows:
    (i) When using appendix M1 to subpart B of part 430, the product 
of:
    (A) The quotient of the represented value of cooling capacity, in 
Btu's per hour as determined in paragraph (b)(3)(iii) of this section, 
and multiplied by 0.93 for variable speed heat pumps only, divided by 
the represented value of SEER2, in Btu's per watt-hour, as determined 
in paragraph (b)(3)(ii) of this section.
    (B) The representative average use cycle for cooling of 1,000 hours 
per year;
    (C) A conversion factor of 0.001 kilowatt per watt; and
    (D) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (ii) When using appendix M2 to subpart B of part 430, the product 
of:
    (A) The quotient of the represented value of cooling capacity, in 
Btu's per hour as determined in paragraph (b)(3)(iii) of this section, 
and multiplied by 0.93 for variable speed heat pumps only, divided by 
the represented value of SCORE, in Btu's per watt-hour, as determined 
in paragraph (b)(3)(ii) of this section.
    (B) The representative average use cycle for cooling of 1,457 hours 
per year;
    (C) A conversion factor of 0.001 kilowatt per watt; and
    (D) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (2) Annual Operating Cost--Heating. Determine the represented value 
of estimated annual operating cost for air-source heat pumps that 
provide only heating or for the heating portion of the estimated annual 
operating cost for air-source heat pumps that provide both heating and 
cooling, as follows:
    (i) When using appendix M1 to subpart B of part 430, the product 
of:
    (A) The quotient of the represented value of cooling capacity (for 
air-source heat pumps that provide both cooling and heating) in Btu's 
per hour, as determined in paragraph (b)(3)(iii) of this section, or 
the represented value of heating capacity (for air-source heat pumps 
that provide only heating), as determined in paragraph (b)(3)(i)(D) of 
this section, divided by the represented value of HSPF2, in Btu's per 
watt-hour, calculated for Region IV, as determined in paragraph 
(b)(3)(ii) of this section;
    (B) The representative average use cycle for heating of 1,572 hours 
per year;
    (C) The adjustment factor of 1.15 (for heat pumps that are not 
variable speed) or 1.07 (for heat pumps that are variable speed), which 
serves to adjust the calculated design heating requirement and heating 
load hours to the actual load experienced by a heating system;
    (D) A conversion factor of 0.001 kilowatt per watt; and
    (E) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act;
    (ii) When using appendix M2 to subpart B of part 430, the product 
of:
    (A) The quotient of the represented value of cooling capacity (for 
air-source heat pumps that provide both cooling and heating) in Btu's 
per hour, as determined in paragraph (b)(3)(iii) of this section, or 
the represented value of heating capacity (for air-source heat pumps 
that provide only heating), as determined in paragraph (b)(3)(i)(D) of 
this section, divided by the represented value of SHORE, in Btu's per 
watt-hour, as determined in paragraph (b)(3)(ii) of this section;
    (B) The representative average use cycle for heating of 972 hours 
per year;
    (C) The adjustment factor of 1.15 (for heat pumps that are not 
variable speed) or 1.07 (for heat pumps that are variable speed), which 
serves to adjust the calculated design heating requirement and heating 
load hours to the actual load experienced by a heating system;
    (D) A conversion factor of 0.001 kilowatt per watt; and
    (E) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act;

[[Page 24257]]

    (3) Annual Operating Cost--Total. Determine the represented value 
of estimated annual operating cost for air-source heat pumps that 
provide both heating and cooling by calculating the sum of the quantity 
determined in paragraph (f)(1) of this section added to the quantity 
determined in paragraph (f)(2) of this section.
    (4) Regional Annual Operating Cost--Cooling. Determine the 
represented value of estimated regional annual operating cost for 
cooling-only units or the cooling portion of the estimated regional 
annual operating cost for air-source heat pumps that provide both 
heating and cooling as follows:
    (i) When using appendix M1 to subpart B of part 430, the product 
of:
    (A) The quotient of the represented value of cooling capacity, in 
Btu's per hour as determined in paragraph (b)(3)(iii) of this section, 
and multiplied by 0.93 for variable speed heat pumps only, divided by 
the represented value of SEER2, in Btu's per watt-hour, as determined 
in paragraph (b)(3)(ii) of this section;
    (B) The estimated number of regional cooling load hours per year 
determined from the following table:

                    Table 4 to Paragraph (f)(4)(i)(B)
------------------------------------------------------------------------
                                                               Regional
                      Climatic region                          cooling
                                                              load hours
------------------------------------------------------------------------
I..........................................................        2,400
II.........................................................        1,800
III........................................................        1,200
IV.........................................................          800
V..........................................................          400
VI.........................................................          200
------------------------------------------------------------------------

    (C) A conversion factor of 0.001 kilowatts per watt; and
    (D) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (ii) When using appendix M2 to subpart B of part 430, regional 
annual operating cost for cooling-only units or the cooling portion of 
the estimated regional annual operating cost air-source heat pumps that 
provide both heating and cooling, does not apply.
    (5) Regional Annual Operating Cost--Heating. Determine the 
represented value of estimated regional annual operating cost for air-
source heat pumps that provide only heating or for the heating portion 
of the estimated regional annual operating cost for air-source heat 
pumps that provide both heating and cooling as follows:
    (i) When using appendix M1 to subpart B of part 430, the product 
of:
    (A) The estimated number of regional heating load hours per year 
determined from the following table:

                    Table 5 to Paragraph (f)(5)(i)(A)
------------------------------------------------------------------------
                                                               Regional
                      Climatic region                          heating
                                                              load hours
------------------------------------------------------------------------
I..........................................................          493
II.........................................................          857
III........................................................        1,247
IV.........................................................        1,701
V..........................................................        2,202
VI.........................................................        1,842
------------------------------------------------------------------------

    (B) The quotient of the represented value of cooling capacity (for 
air-source heat pumps that provide both cooling and heating) in Btu's 
per hour, as determined in paragraph (b)(3)(i)(C) of this section, or 
the represented value of heating capacity (for air-source heat pumps 
that provide only heating), as determined in paragraph (b)(3)(i)(D) of 
this section, divided by the represented value of HSPF2, in Btu's per 
watt-hour, calculated for the appropriate generalized climatic region 
of interest, and determined in paragraph (b)(3)(i)(B) of this section;
    (C) The adjustment factor of 1.15 (for heat pumps that are not 
variable speed) or 1.07 (for heat pumps that are variable speed), which 
serves to adjust the calculated design heating requirement and heating 
load hours to the actual load experienced by a heating system;
    (D) A conversion factor of 0.001 kilowatts per watt; and
    (E) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (ii) When using appendix M2 to subpart B of part 430, regional 
annual operating cost for air-source heat pumps that provide only 
heating or for the heating portion, does not apply.
    (6) Regional Annual Operating Cost--Total. For air-source heat 
pumps that provide both heating and cooling, the estimated regional 
annual operating cost is the sum of the quantity determined in 
paragraph (f)(4) of this section added to the quantity determined in 
paragraph (f)(5) of this section.
    (7) Annual Operating Cost--Rounding. Round any represented values 
of estimated annual operating cost determined in paragraphs (f)(1) 
through (6) of this section to the nearest dollar per year.
0
4. Amend Sec.  429.70 by revising paragraphs (e)(1) and (e)(2)(i)(A) to 
read as follows:


Sec.  429.70  Alternative methods for determining energy efficiency and 
energy use.

* * * * *
    (e) * * *
    (1) Criteria an AEDM must satisfy. A manufacturer may not apply an 
AEDM to an individual model/combination to determine its represented 
values (SEER2, EER2, HSPF2, SCORE, SHORE and/or PW,OFF) 
pursuant to this section unless authorized pursuant to Sec.  429.16(d) 
and:
    (i) The AEDM is derived from a mathematical model that estimates 
the energy efficiency or energy consumption characteristics of the 
individual model or combination (SEER2, EER2, HSPF2, SCORE, SHORE and/
or PW,OFF) as measured by the applicable DOE test procedure; 
and
    (ii) The manufacturer has validated the AEDM in accordance with 
paragraph (e)(2) of this section.
    (2) * * *
    (i) * * *
    (A) Minimum testing. The manufacturer must test each basic model as 
required under Sec.  429.16(b)(2).
* * * * *
0
5. Amend Sec.  429.134 by revising paragraph (k) to read as follows:


Sec.  429.134  Product-specific enforcement provisions.

* * * * *
    (k) Central air conditioners and heat pumps--Before [Date 180 days 
after publication of the final rule in the Federal Register], the 
provisions in this section of this title as it appeared in the 10 CFR 
parts 200-499 edition revised as of January 1, 2023 are applicable. On 
and after [Date 180 days after publication of the final rule in the 
Federal Register], the following provisions apply.
    (1) Verification of cooling capacity. The cooling capacity of each 
tested unit of the individual model (for single-package systems) or 
individual combination (for split systems) will be measured pursuant to 
the test requirements of Sec.  430.23(m) of this chapter. The mean of 
the measurement(s) (either the measured cooling capacity for a single 
unit sample or the average of the measured cooling capacities for a 
multiple unit sample) will be used to determine the applicable 
standards for purposes of compliance.
    (2) Verification of CD value. (i) For central air conditioners and 
heat pumps other than models of outdoor units with no match, if 
manufacturers certify that they did not conduct the optional tests to 
determine the CD\c\ and/or CD\h\ value for an 
individual model (for single-package systems) or individual

[[Page 24258]]

combination (for split systems), as applicable, for each unit tested, 
the default CD\c\ and/or CD\h\ value will be used 
as the basis for the calculation of SEER2 or HSPF2 when testing in 
accordance with appendix M1 to subpart B of part 430, or SCORE or SHORE 
when testing in accordance with appendix M2 to subpart B of part 430. 
If manufacturers certify that they conducted the optional tests to 
determine the CD\c\ and/or CD\h\ value for an 
individual model (for single-package systems) or individual combination 
(for split systems), as applicable, the following provisions apply.
    (A) If testing in accordance with appendix M1 to subpart B of part 
430, the CD\c\ and/or CD\h\ value will be 
measured for each unit tested pursuant to appendix M1 to subpart B of 
part 430 and the result for each unit tested (either the tested value 
or the default value, as selected according to the criteria for the 
cyclic test in section E17 of AHRI 210/240-202X (incorporated by 
reference, see Sec.  429.4)) will be used as the basis for calculation 
of SEER2 or HSPF2.
    (B) If testing in accordance with appendix M2 to subpart B of part 
430, the CD\c\ and/or CD\h\ value will be 
measured for each unit tested pursuant to appendix M2 to subpart B of 
part 430 and the result for each unit tested (either the tested value 
or the default value, as selected according to the criteria for the 
cyclic test in section E17 of AHRI 1600-202X (incorporated by 
reference, see Sec.  429.4)) will be used as the basis for calculation 
of SCORE or SHORE.
    (ii) For models of outdoor units with no match, DOE will use the 
default CD\c\ and/or CD\h\ pursuant to appendix 
M1 to subpart B of part 430 or appendix M2 to subpart B of part 430, as 
applicable.
    (3) Verification of cut-out and cut-in temperatures for central 
heat pumps. (i) When testing in accordance with appendix M1 to subpart 
B of part 430, the cut-out and cut-in temperatures may be verified 
using the method in appendix J of AHRI 210/240-202X (incorporated by 
reference, see Sec.  429.4). If this method is conducted, the tested 
TOFF,T and TON,T values determined in the test 
shall be used as the cut-out and cut-in temperatures, respectively, to 
calculate HSPF2.
    (ii) When testing in accordance with appendix M2 to subpart B of 
part 430, the cut-out and cut-in temperatures may be verified using the 
method in appendix J of AHRI 1600-202X (incorporated by reference, see 
Sec.  429.4). If this method is conducted, the tested TOFF,T 
and TON,T values determined in the test shall be used as the 
cut-out and cut-in temperatures, respectively, to calculate SHORE.
    (4) Verification of Variable Capacity Operation and of Fixed 
Settings for the Compressor and the Indoor Fan when Testing Variable 
Capacity Compressor Systems--(i) Conducting the Controls Verification 
Procedure. A controls verification procedure (CVP) may be performed for 
any model certified as a variable capacity compressor system for the 
purposes of assessment or enforcement testing conducted according to 
appendix M1 to subpart B of part 430 or appendix M2 to subpart B of 
part 430 (i.e., the certification tests), as applicable. For a heat 
pump, either a cooling mode CVP, a heating mode CVP, or both may be 
conducted, as elected by DOE. If a CVP is not conducted, the override 
instructions for the compressor and indoor fan, as specified by the 
manufacturer, will be used to conduct the tests per appendix M1 to 
subpart B of part 430 or, appendix M2 to subpart B of part 430, as 
applicable.
    (A) When testing in accordance with appendix M1 to subpart B of 
part 430. The CVP will be conducted per appendix I of AHRI 210/240-202X 
(incorporated by reference, see Sec.  429.4).
    (B) When testing in accordance with appendix M2 to subpart B of 
part 430. The CVP will be conducted per appendix I of AHRI 1600-202X 
(incorporated by reference, see Sec.  429.4).
    (C) For systems determined to be variable capacity certified, 
single capacity systems as described in paragraph (k)(4)(ii)(B) of this 
section, the CVP cooling and heating minimum intervals may be omitted.
    (ii) Variable Capacity Determination.(A) If the unit tested does 
meet the definition of a variable capacity compressor system based on 
performance of the CVP per paragraph (k)(4)(i)(A) or paragraph 
(k)(4)(i)(B) of this section, the efficiency metrics (SEER2, HSPF2, 
EER2, SCORE, SHORE, as applicable) shall be determined using the 
certification test applicable to variable capacity compressor systems.
    (B) If the unit tested does not meet the definition of a variable 
capacity compressor system based on performance of the CVP per 
paragraph (k)(4)(i)(A) or paragraph (k)(4)(i)(B) of this section, and 
the tested unit is instead determined to be a variable capacity 
certified, single capacity system, the efficiency metrics (SEER2, 
HSPF2, EER2, SCORE, SHORE, as applicable) shall be determined using the 
certification test applicable to variable capacity certified, single 
capacity systems.
    (C) If the unit tested does not meet the definition of a variable 
capacity compressor system based on performance of the CVP per 
paragraph (k)(4)(i)(A) or paragraph (k)(4)(i)(B) of this section, and 
the tested unit is instead determined to be a variable capacity 
certified, two capacity system, the efficiency metrics (SEER2, HSPF2, 
EER2, SCORE, SHORE, as applicable) shall be determined using the 
certification test applicable to variable capacity certified, two 
capacity systems.
    (D) If, for a heat pump, a CVP is conducted for just one of the 
operating modes (heating or cooling), the system classifications for 
both modes will be based on the results of the one CVP conducted.
    (iii) CVP Tolerance Evaluation for Full and Minimum Load Intervals.
    (A) The data collected in the CVP per paragraph (k)(4)(i)(A) or 
paragraph (k)(4)(i)(B) of this section shall be evaluated for the 
duration of the individual CVP full or minimum load interval excluding 
the preliminary 30 minutes of equilibrium data, to determine compliance 
with test condition tolerances and test operating tolerances listed in 
section I5.1 of appendix I of AHRI 210/240-202X (incorporated by 
reference, see Sec.  429.4) (if testing in accordance with appendix 
M1); or of AHRI 1600-202X (incorporated by reference, see Sec.  429.4) 
(if testing in accordance with appendix M2).
    (1) If the specified tolerances are met under system operation for 
60 minutes, the average capacity and average power measured over this 
60-minute test interval shall be recorded.
    (2) If the four-hour time limit is reached by the system without 
maintaining the tolerances for a 60-minute period, but two successive 
test period sub-intervals are identified, each a minimum of 30 minutes, 
and comprised of a whole number of compressor cycles (either compressor 
on-off cycles or speed/capacity cycles) or in which minimal 
fluctuations of the compressor speed/capacity level are observed, where 
both the time averaged integrated capacity and time averaged integrated 
power for the full 60 minutes of the two periods are observed to be 
within two percent of each other, a single capacity average and a 
single power average shall be recorded, both averaged over compressor-
on periods of the two 60-minute sub-intervals. These average capacity 
and power values shall be considered the capacity and power values 
recorded for the test interval.
    (3) If the four-hour time limit is reached by the system without 
complying with either paragraph (k)(4)(iii)(A)(1) or (k)(4)(iii)(B)(2) 
of this section, the time averaged integrated

[[Page 24259]]

capacity and time averaged integrated power shall be recorded for only 
the compressor-on periods over the final 120 minutes of the test 
interval.
    (B) The measured capacity for each full load interval, as evaluated 
per the CVP conducted in paragraph (k)(4)(i)(A) or paragraph 
(k)(4)(i)(B) of this section, shall agree with the corresponding 
certification test within 6%, as follows:
[GRAPHIC] [TIFF OMITTED] TP05AP24.056

[GRAPHIC] [TIFF OMITTED] TP05AP24.057

[GRAPHIC] [TIFF OMITTED] TP05AP24.058

    (C) The measured capacity for each minimum load interval, as 
evaluated per the CVP conducted in paragraph (k)(4)(i)(A) or paragraph 
(k)(4)(i)(B) of this section, shall agree with the corresponding 
certification test within 6% of the cooling or heating mode full load 
certification test capacity, as follows:
[GRAPHIC] [TIFF OMITTED] TP05AP24.059

[GRAPHIC] [TIFF OMITTED] TP05AP24.060

    (D) The measured efficiency for the full and minimum load interval, 
as evaluated per the CVP conducted in paragraph (k)(4)(i)(A) or 
paragraph (k)(4)(i)(B) of this section, shall agree with the 
corresponding certification test within 10%, as follows:
[GRAPHIC] [TIFF OMITTED] TP05AP24.061

[GRAPHIC] [TIFF OMITTED] TP05AP24.062

    (iv) Evaluation of results when CVP tolerances are met. If the 
tolerances for capacity and efficiency are met by the applicable full 
and minimum load intervals as per paragraphs (k)(4)(iii)(B), 
(k)(4)(iii)(C) and (k)(4)(iii)(D) of this section, the certified 
override instructions for the compressor and indoor fan, as specified 
by the manufacturer, shall be deemed valid, and the efficiency metrics 
(SEER2, HSPF2, EER2, SCORE, SHORE, as applicable), shall be determined 
based on these certification tests with no adjustments determined based 
on the CVP results.
    (v) Evaluation of results when CVP tolerances are not met. If the 
tolerances for capacity and efficiency are not met by the applicable 
full and minimum load intervals as per paragraphs (k)(4)(iii)(B), 
(k)(4)(iii)(C) and (k)(4)(iii)(D) of this section, the unit shall be 
tested per instructions in paragraphs (k)(4)(v)(A) to (k)(4)(v)(C) of 
this section, as applicable. The instructions in paragraphs 
(k)(4)(v)(A) to (k)(4)(v)(C) of this section shall be followed, as 
applicable, only for the certification tests corresponding to the

[[Page 24260]]

failed compressor speed interval based on the evaluations of paragraphs 
(k)(4)(iii)(B), (k)(4)(iii)(C) and (k)(4)(iii)(D) of this section. For 
all compressor speed intervals for which the capacity and EER/COP are 
in tolerance as per paragraphs (k)(4)(iii)(B), (k)(4)(iii)(C) and 
(k)(4)(iii)(D) of this section, the corresponding certification tests 
shall be used without adjustments.
    (A) The instructions of this paragraph shall be applied to systems 
for which the same control device used as per the CVP conducted in 
paragraph (k)(4)(i)(A) or paragraph (k)(4)(i)(B) of this section is 
used as the means for overriding the controls, and both (a) monitoring 
of the compressor and indoor blower speed during native-control 
operation without otherwise impacting the control of the system, and 
(b) monitoring and adjustment of the compressor and indoor blower speed 
during certification tests, where monitoring and adjustment means the 
control device has the ability to display and make discrete 
adjustments, as required, to the compressor and indoor blower speeds 
without additional hardware or non-publicly available software, is 
supported by the control device. The compressor and indoor blower speed 
shall be monitored during the CVP conducted in paragraph (k)(4)(i)(A) 
or paragraph (k)(4)(i)(B) of this section. The average compressor and 
indoor blower speeds and indoor air volume rate shall be evaluated for 
the same time period(s) used as described in paragraph (k)(4)(iii)(A) 
to determine average capacity and power for the CVP test. The 
compressor speed for the certification test shall be set at this 
average value observed during the corresponding CVP test interval. The 
indoor blower speed shall be set as described in section 6.1.5 of AHRI 
210/240-202X (incorporated by reference, see Sec.  429.4) (if testing 
in accordance with appendix M1); or of AHRI 1600-202X (incorporated by 
reference, see Sec.  429.4) (if testing in accordance with appendix 
M2), except the ``specified airflow'' shall be set as the average value 
observed during the corresponding CVP test interval. The same adjusted 
compressor speed shall be used for the other certification tests that 
require the same speed, as applicable, as detailed in the following 
table. Specifically, for each of the CVP tests listed in the first 
column for which either the capacity tolerances of paragraph 
(k)(4)(iii)(B) or paragraph (k)(4)(iii)(C) of this section are not met 
or the efficiency tolerances of paragraph (k)(4)(iii)(D) are not met, 
the certification tests to be conducted again using the compressor 
speed determined in the corresponding CVP test are listed in the last 
three columns of the table, depending on which of the three kinds of 
system the model is designated. If required, the adjusted qH3,Full and 
PH3,Full shall be used to calculate qk=2 hcalc (47) and P k=2 hcalc 
(47), respectively, to represent performance at 47 [deg]F as described 
in section 11.2.2.4 of AHRI 210/240-202X (incorporated by reference, 
see Sec.  429.4) (if testing in accordance with appendix M1), or of 
AHRI 1600-202X (incorporated by reference, see Sec.  429.4) (if testing 
in accordance with appendix M2), and for use in calculating performance 
at 35 [deg]F. If required, the adjusted H1,Low and 
H3,Low tests shall be used to calculate qthi,H2,Low and 
PH2,Low, respectively, as described in section 6.1.3.4 of AHRI 210/240-
202X (incorporated by reference, see Sec.  429.4) (if testing in 
accordance with appendix M1), or of AHRI 1600-202X (incorporated by 
reference, see Sec.  429.4) (if testing in accordance with appendix 
M2). No adjustments are required for intermediate or nominal compressor 
speed tests or, if cyclic tests are conducted, for the degradation 
coefficient(s).

                                        Table 1 to Paragraph (k)(4)(v)(A)
----------------------------------------------------------------------------------------------------------------
                                        Certification Tests that use the Indicated CVP Test Compressor Speed or
                                       would have certification test results adjusted per Paragraph (k)(4)(v)(B)
                                        of this section, if the CVP Test is out of Capacity or EER/COP Tolerance
                                                       per Paragraph (k)(4)(iii) of this section
               CVP Test               --------------------------------------------------------------------------
                                          Variable capacity        Variable capacity
                                          certified, single          certified, two         Variable capacity
                                           capacity system          capacity system               system
----------------------------------------------------------------------------------------------------------------
Afull................................  AFull, BFull...........  AFull, BFull...........  AFull, BFull.
Flow.................................  N/A....................  BLow, FLow.............  BLow, FLow.
H1,low...............................  N/A....................  H0,Low, H1,Low, H3,Low.  H0,Low, H1,Low.
H3,full..............................  H2,Full, H3,Full.......  H3,Full................  H3,Full.
H4,Full..............................  H4,Full................  H4,Full................  H4,Full.
----------------------------------------------------------------------------------------------------------------

    (B) The instructions of this paragraph shall be applied to systems 
for which the means for overriding the compressor and indoor blower 
speed as discussed in paragraph (k)(4)(v)(A) of this section is not 
provided by the control used for conducting the CVP. For each of the 
CVP tests listed in the first column of Table 1 of this section for 
which either the capacity tolerances of paragraph (k)(4)(iii)(B) or 
paragraph (k)(4)(iii)(C) of this section are not met or the efficiency 
tolerances of paragraph (k)(4)(iii)(D) are not met, depending on which 
of the three kinds of system the model is designated, the certification 
test results to be adjusted based on the results of the CVP test are 
indicated by the last three columns of the table for each CVP test 
listed in the first column. The average capacities and power(s) 
measured during the CVP time period(s) described in paragraph 
(k)(4)(iii)(A) of this section shall be used. For the certification 
tests requiring adjustment with no CVP interval (any required 
certification test other than Afull, Flow, 
H1low, H3full and H4full), the 
capacity and power shall be adjusted. The capacity shall be adjusted by 
applying the ratio of the capacity measured during the CVP test 
interval divided by the capacity measured during the certification test 
(for the corresponding CVP interval). The power shall be adjusted by 
applying the ratio of the efficiency measured during the CVP test 
interval divided by the efficiency measured during the certification 
test (for the corresponding CVP interval), as follows:
    Cooling full capacity:
    [GRAPHIC] [TIFF OMITTED] TP05AP24.063
    

[[Page 24261]]


    Cooling full power:
    [GRAPHIC] [TIFF OMITTED] TP05AP24.064
    
    Cooling minimum capacity:
    [GRAPHIC] [TIFF OMITTED] TP05AP24.065
    
    Cooling minimum power:
    [GRAPHIC] [TIFF OMITTED] TP05AP24.066
    
    Heating minimum capacity:
    [GRAPHIC] [TIFF OMITTED] TP05AP24.067
    
    Heating minimum power:
    [GRAPHIC] [TIFF OMITTED] TP05AP24.068
    
    [GRAPHIC] [TIFF OMITTED] TP05AP24.069
    
Where:

CSF = 0.0204/[deg]F, capacity slope factor for Split Systems
CSF = 0.0262/[deg]F, capacity slope factor for Single Package Units
PSF = 0.00455/[deg]F, power slope factor for all products

    (C) If required, the measured QH3,Full and EH3,Full from the CVP 
shall be used to calculate qk=2 hcalc(47) and Pk=2 hcalc (47), 
respectively, to represent performance at 47 [deg]F as described in 
section 11.2.2.4 of AHRI 210/240-202X (incorporated by reference, see 
Sec.  429.4) (if testing in accordance with appendix M1), or of AHRI 
1600-202X (incorporated by reference, see Sec.  429.4) (if testing in 
accordance with appendix M2), and for use in calculating performance at 
35 [deg]F. If required, the measured H1,Low from the CVP and 
the adjusted H3,Low tests shall be used to calculate 
qthi,H2,Low and PH2,Low, respectively, as described in section 6.1.3.4 
of AHRI 210/240-202X (incorporated by reference, see Sec.  429.4) (if 
testing in accordance with appendix M1) or of AHRI 1600-202X 
(incorporated by reference, see Sec.  429.4) (if testing in accordance 
with appendix M2). No adjustments are required for intermediate or 
nominal compressor speed tests or, if cyclic tests are conducted, the 
degradation coefficient(s).
    (D) If the test unit is determined to be variable capacity 
certified, single capacity system, or variable capacity certified, two 
capacity system and is not certified or marketed for use with only a 
proprietary control device, the same simulated thermostat low voltage 
signal that resulted in full speed compressor operation for the full 
load intervals shall be used for all certification full load tests. If 
the test unit is determined to be variable capacity certified, two 
capacity system, the same simulated thermostat low voltage signal that 
resulted in low-speed compressor operation for the low load intervals 
shall be used for all certification low load tests.
* * * * *

PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

0
6. The authority citation for part 430 continues to read as follows:

    Authority:  42 U.S.C. 6291-6309; 28 U.S.C. 2461 note.

0
7. Amend Sec.  430.3 by revising paragraphs (b)(4), (c) and (g) to read 
as follows:


Sec.  430.3  Materials incorporated by reference.

* * * * *
    (b) * * *
    (4) ANSI/AMCA 210-07, ANSI/ASHRAE 51-07 (``AMCA 210-2007''), 
Laboratory Methods of Testing Fans for Certified Aerodynamic 
Performance

[[Page 24262]]

Rating, ANSI approved August 17, 2007, Section 8--Report and Results of 
Test, Section 8.2--Performance graphical representation of test 
results, IBR approved for appendix M to subpart B, as follows:
    (i) Figure 2A--Static Pressure Tap, and
    (ii) Figure 12--Outlet Chamber Setup--Multiple Nozzles in Chamber.
* * * * *
    (c) AHRI. Air-Conditioning, Heating, and Refrigeration Institute, 
2111 Wilson Blvd., Suite 500, Arlington, VA 22201, 703-524-8800, or go 
to https://www.ahrinet.org.
    (1) ANSI/AHRI 210/240-2008 with Addenda 1 and 2 (''AHRI 210/240-
2008''), 2008 Standard for Performance Rating of Unitary Air-
Conditioning & Air-Source Heat Pump Equipment, ANSI approved October 
27, 2011 (Addendum 1 dated June 2011 and Addendum 2 dated March 2012), 
IBR approved for appendix M to subpart B, as follows:
    (i) Section 6--Rating Requirements, Section 6.1--Standard Ratings, 
6.1.3--Standard Rating Tests, 6.1.3.2--Electrical Conditions;
    (ii) Section 6--Rating Requirements, Section 6.1--Standard Ratings, 
6.1.3--Standard Rating Tests, 6.1.3.4--Outdoor-Coil Airflow Rate;
    (iii) Section 6--Rating Requirements, Section 6.1--Standard 
Ratings, 6.1.3--Standard Rating Tests, 6.1.3.5--Requirements for 
Separated Assemblies;
    (iv) Figure D1--Tunnel Air Enthalpy Test Method Arrangement;
    (v) Figure D2--Loop Air Enthalpy Test Method Arrangement; and
    (vi) Figure D4--Room Air Enthalpy Test Method Arrangement.
    (2) AHRI Standard 210/240-202X (``AHRI 210/240-202X''), 202X 
Standard for Performance Rating of Unitary Air-Conditioning & Air-
Source Heat Pump Equipment [version and date TBD]; IBR approved for 
appendix M1 to subpart B.
    (3) AHRI Standard 1160-2009 (``AHRI 1160''), Performance Rating of 
Heat Pump Pool Heaters, 2009, IBR approved for appendix P to subpart B.
    (4) ANSI/AHRI 1230-2010 with Addendum 2 (``AHRI 1230-2010''), 2010 
Standard for Performance Rating of Variable Refrigerant Flow (VRF) 
Multi-Split Air-Conditioning and Heat Pump Equipment (including 
Addendum 1 dated March 2011), ANSI approved August 2, 2010 (Addendum 2 
dated June 2014), IBR approved for appendix M to subpart B, as follows:
    (i) Section 3--Definitions (except 3.8, 3.9, 3.13, 3.14, 3.15, 
3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29, 3.30, and 3.31);
    (ii) Section 5--Test Requirements, Section 5.1 (untitled), 5.1.3-
5.1.4;
    (iii) Section 6--Rating Requirements, Section 6.1--Standard 
Ratings, 6.1.5--Airflow Requirements for Systems with Capacities 
<65,000 Btu/h [19,000 W];
    (iv) Section 6--Rating Requirements, Section 6.1--Standard Ratings, 
6.1.6--Outdoor-Coil Airflow Rate (Applies to all Air-to-Air Systems);
    (v) Section 6--Rating Requirements, Section 6.2--Conditions for 
Standard Rating Test for Air-cooled Systems < 65,000 Btu/h [19,000W] 
(except Table 8); and
    (vi) Table 4--Refrigerant Line Length Correction Factors.
    (5) AHRI 1600-202X (``AHRI 1600-202X''), 202X Standard for 
Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump 
Equipment, [version and date TBD]; IBR approved for appendix M2 to 
subpart B.
* * * * *
    (g) ASHRAE. American Society of Heating, Refrigerating, and Air-
Conditioning Engineers, Inc., 180 Technology Parkway NW, Peachtree 
Corners, GA 30092; (800) 527-4723 or (404) 636-8400; www.ashrae.org.
    (1) ANSI/ASHRAE Standard 16-2016 (``ANSI/ASHRAE 16''), Method of 
Testing for Rating Room Air Conditioners, Packaged Terminal Air 
Conditioners, and Packaged Terminal Heat Pumps for Cooling and Heating 
Capacity, ANSI approved November 1, 2016; IBR approved for appendices 
F, M1, and M2 to subpart B.
    (2) ANSI/ASHRAE 23.1-2010, (``ASHRAE 23.1-2010''), Methods of 
Testing for Rating the Performance of Positive Displacement Refrigerant 
Compressors and Condensing Units that Operate at Subcritical 
Temperatures of the Refrigerant, ANSI approved January 28, 2010, IBR 
approved for appendix M to subpart B, as follows:
    (i) Section 5--Requirements;
    (ii) Section 6--Instruments;
    (iii) Section 7--Methods of Testing; and
    (iv) Section 8--Compressor Testing.
    (3) ANSI/ASHRAE Standard 37-2009, (``ASHRAE 37-2009''), Methods of 
Testing for Rating Electrically Driven Unitary Air-Conditioning and 
Heat Pump Equipment, ANSI approved June 25, 2009, IBR approved for 
appendices M1, M2, AA, CC, and CC1 to subpart B.
    (4) ANSI/ASHRAE Standard 37-2009, (``ANSI/ASHRAE 37-2009''), 
Methods of Testing for Rating Electrically Driven Unitary Air-
Conditioning and Heat Pump Equipment, ANSI approved June 25, 2009, IBR 
approved for appendix M to subpart B, as follows:
    (i) Section 5--Instruments, Section 5.1--Temperature Measuring 
Instruments: 5.1.1;
    (ii) Section 5--Instruments, Section 5.2--Refrigerant, Liquid, and 
Barometric Pressure Measuring Instruments;
    (iii) Section 5--Instruments, Section 5.5--Volatile Refrigerant 
Flow Measurement;
    (iv) Section 6--Airflow and Air Differential Pressure Measurement 
Apparatus, Section 6.1--Enthalpy Apparatus (Excluding Figure 3): 6.1.1-
6.1.2 and 6.1.4;
    (v) Section 6--Airflow and Air Differential Pressure Measurement 
Apparatus, Section 6.2--Nozzle Airflow Measuring Apparatus (Excluding 
Figure 5);
    (vi) Section 6--Airflow and Air Differential Pressure Measurement 
Apparatus, Section 6.3--Nozzles (Excluding Figure 6);
    (vii) Section 6--Airflow and Air Differential Pressure Measurement 
Apparatus, Section 6.4--External Static Pressure Measurements;
    (viii) Section 6--Airflow and Air Differential Pressure Measurement 
Apparatus, Section 6.5--Recommended Practices for Static Pressure 
Measurements;
    (ix) Section 7--Methods of Testing and Calculation, Section 7.3--
Indoor and Outdoor Air Enthalpy Methods (Excluding Table 1);
    (x) Section 7--Methods of Testing and Calculation, Section 7.4--
Compressor Calibration Method;
    (xi) Section 7--Methods of Testing and Calculation, Section 7.5--
Refrigerant Enthalpy Method;
    (xii) Section 7--Methods of Testing and Calculation, Section 7.7--
Airflow Rate Measurement, Section 7.7.2--Calculations--Nozzle Airflow 
Measuring Apparatus (Excluding Figure 10), 7.7.2.1-7.7.2.2;
    (xiii) Section 8--Test Procedures, Section 8.1--Test Room 
Requirements: 8.1.2-8.1.3;
    (xiv) Section 8--Test Procedures, Section 8.2--Equipment 
Installation;
    (xv) Section 8--Test Procedures, Section 8.6--Additional 
Requirements for the Outdoor Air Enthalpy Method, Section 8.6.2;
    (xvii) Section 8--Test Procedures, Section 8.6--Additional 
Requirements for the Outdoor Air Enthalpy Method, Table 2a--Test 
Tolerances (SI Units), and
    (xviii) Section 8--Test Procedures, Section 8.6--Additional 
Requirements for the Outdoor Air Enthalpy Method, Table 2b--Test 
Tolerances (I-P Units);
    (xix) Section 9--Data to be Recorded, Section 9.2--Test Tolerances; 
and
    (xx) Section 9--Data to be Recorded, Table 3--Data to be Recorded.

[[Page 24263]]

    (5) ASHRAE 41.1-1986 (Reaffirmed 2006) (``ASHRAE 41.1-1986''), 
Standard Method for Temperature Measurement, approved February 18, 
1987; IBR approved for appendices AA, CC, and CC1 to subpart B.
    (6) ANSI/ASHRAE 41.1-2013 (``ANSI/ASHRAE 41.1''), Standard Method 
for Temperature Measurement, ANSI approved January 30, 2013; IBR 
approved for appendices F and X1 to subpart B.
    (7) ANSI/ASHRAE Standard 41.1-2013, (``ANSI/ASHRAE 41.1-2013''), 
Standard Method for Temperature Measurement, ANSI approved January 30, 
2013, IBR approved for appendix M to subpart B, as follows:
    (i) Section 4--Classifications;
    (ii) Section 5--Requirements, Section 5.3--Airstream Temperature 
Measurements;
    (iii) Section 6--Instruments; and
    (iv) Section 7--Temperature Test Methods (Informative).
    (8) ANSI/ASHRAE Standard 41.1-2020 (``ASHRAE 41.1-2020''), Standard 
Methods for Temperature Measurement, ANSI-approved June 30, 2020; IBR 
approved for appendix E to subpart B.
    (9) ANSI/ASHRAE Standard 41.2-1987 (RA 92), (``ASHRAE 41.2-1987 (RA 
1992)''), Standard Methods for Laboratory Airflow Measurement, ANSI 
reaffirmed April 20, 1992; IBR approved for appendix F to subpart B.
    (10) ANSI/ASHRAE Standard 41.2-1987 (RA 1992), (``ASHRAE 41.2-1987 
(RA 1992)''), Standard Methods for Laboratory Airflow Measurement, ANSI 
reaffirmed April 20, 1992, Section 5--Section of Airflow-Measuring 
Equipment and Systems, IBR approved for appendix M to subpart B, as 
follows:
    (i) Section 5.2--Test Ducts, Section 5.2.2--Mixers, 5.2.2.1--
Performance of Mixers (excluding Figures 11 and 12 and Table 1); and
    (ii) Figure 14--Outlet Chamber Setup for Multiple Nozzles in 
Chamber.
    (11) ANSI/ASHRAE Standard 41.3-2014, (``ASHRAE 41.3-2014''), 
Standard Methods for Pressure Measurement, ANSI approved July 3, 2014; 
IBR approved for appendix F to subpart B.
    (12) ANSI/ASHRAE Standard 41.6-1994 (RA 2006) (``ASHRAE 41.6-
1994''), Standard Method for Measurement of Moist Air Properties, ANSI-
reaffirmed January 27, 2006; IBR approved for appendices CC and CC1 to 
subpart B.
    (13) ANSI/ASHRAE Standard 41.6-2014, (``ASHRAE 41.6-2014''), 
Standard Method for Humidity Measurement, ANSI approved July 3, 2014; 
IBR approved for appendices E, F, and EE to subpart B.
    (14) ANSI/ASHRAE Standard 41.6-2014, (``ASHRAE 41.6-2014''), 
Standard Method for Humidity Measurement, ANSI approved July 3, 2014, 
IBR approved for appendix M to subpart B, as follows:
    (i) Section 4--Classifications;
    (ii) Section 5--Requirements;
    (iii) Section 6--Instruments and Calibration; and
    (iv) Section 7--Humidity Measurement Methods.
    (15) ANSI/ASHRAE 41.9-2011, (``ASHRAE 41.9-2011''), Standard 
Methods for Volatile-Refrigerant Mass Flow Measurements Using 
Calorimeters, ANSI approved February 3, 2011, IBR approved for appendix 
M to subpart B, as follows:
    (i) Section 5--Requirements;
    (ii) Section 6--Instruments;
    (iii) Section 7--Secondary Refrigerant Calorimeter Method;
    (iv) Section 8--Secondary Fluid Calorimeter Method;
    (v) Section 9--Primary Refrigerant Calorimeter Method; and
    (vi) Section 11--Lubrication Circulation Measurements.
    (16) ANSI/ASHRAE Standard 41.11-2014, (``ASHRAE 41.11-2014''), 
Standard Methods for Power Measurement, ANSI approved July 3, 2014; IBR 
approved for appendix F to subpart B.
    (17) ANSI/ASHRAE Standard 103-1993, (``ASHRAE 103-1993''), Methods 
of Testing for Annual Fuel Utilization Efficiency of Residential 
Central Furnaces and Boilers, (with Errata of October 24, 1996), except 
for sections 7.1, 7.2.2.2, 7.2.2.5, 7.2.3.1, 7.8, 8.2.1.3, 8.3.3.1, 
8.4.1.1, 8.4.1.1.2, 8.4.1.2, 8.4.2.1.4, 8.4.2.1.6, 8.6.1.1, 8.7.2, 
8.8.3, 9.1.2.2.1, 9.1.2.2.2, 9.5.1.1, 9.5.1.2.1, 9.5.1.2.2, 9.5.2.1, 
9.7.1, 9.7.4, 9.7.6, 9.10, 11.5.11.1, 11.5.11.2 and appendices B and C, 
approved October 4, 1993; IBR approved for Sec.  430.23 and appendix N 
to subpart B.
    (18) ANSI/ASHRAE Standard 103-2007 (``ASHRAE 103-2007''), Method of 
Testing for Annual Fuel Utilization Efficiency of Residential Central 
Furnaces and Boilers, ANSI-approved March 25, 2008; IBR approved for 
appendix AA to subpart B.
    (19) ANSI/ASHRAE Standard 103-2017 (``ASHRAE 103-2017''), Method of 
Testing for Annual Fuel Utilization Efficiency of Residential Central 
Furnaces and Boilers, ANSI-approved July 3, 2017; IBR approved for 
Sec.  430.23 and appendices O and EE to subpart B.
    (20) ANSI/ASHRAE Standard 116-2010, (``ASHRAE 116-2010''), Methods 
of Testing for Rating Seasonal Efficiency of Unitary Air Conditioners 
and Heat Pumps, ANSI approved February 24, 2010, Section 7--Methods of 
Test, Section 7.4--Air Enthalpy Method--Indoor Side (Primary Method), 
Section 7.4.3--Measurements, Section 7.4.3.4--Temperature, Section 
7.4.3.4.5, IBR approved for appendix M to subpart B.
    (21) ANSI/ASHRAE Standard 116-2010, (``ASHRAE 116-2010''), Methods 
of Testing for Rating Seasonal Efficiency of Unitary Air Conditioners 
and Heat Pumps, ANSI approved February 24, 2010; IBR approved for 
appendices M1 and M2 to subpart B.
    (22) ANSI/ASHRAE Standard 118.2-2022 (``ASHRAE 118.2-2022''), 
Method of Testing for Rating Residential Water Heaters and Residential-
Duty Commercial Water Heaters, ANSI-approved March 1, 2022; IBR 
approved for appendix E to subpart B.
    (23) ANSI/ASHRAE Standard 146-2011 (``ASHRAE 146''), Method of 
Testing and Rating Pool Heaters, ASHRAE approved February 2, 2011; IBR 
approved for appendix P to subpart B.
* * * * *
0
8. Amend Sec.  430.23 by revising paragraph (m) to read as follows:


Sec.  430.23  Test procedures for the measurement of energy and water 
consumption.

* * * * *
    (m) Central air conditioners and heat pumps. See the note at the 
beginning of appendices M1 and M2 to this subpart to determine the 
appropriate test method. Determine all values discussed in this section 
using a single appendix.
    (1) Determine cooling capacity from the steady-state wet-coil test 
(A or Afull Test), as per instructions in section 2 of 
appendix M1 or M2 to this subpart, and rounded off to the nearest:
    (i) To the nearest 50 Btu/h if cooling capacity is less than 20,000 
Btu/h;
    (ii) To the nearest 100 Btu/h if cooling capacity is greater than 
or equal to 20,000 Btu/h but less than 38,000 Btu/h; and
    (iii) To the nearest 250 Btu/h if cooling capacity is greater than 
or equal to 38,000 Btu/h and less than 65,000 Btu/h.
    (2) Determine seasonal energy efficiency ratio 2 (SEER2) as 
described in sections 2 and 4 of appendix M1 to this subpart or 
seasonal cooling and off-mode rating efficiency (SCORE) as described in 
sections 2 and 3 of appendix M2 to this subpart, and round off to the 
nearest 0.025 Btu/W-h.
    (3) Determine energy efficiency ratio 2 (EER2) as described in 
section 2 of appendix M1 or M2 to this subpart, and round off to the 
nearest 0.025 Btu/W-h. EER2 is the efficiency from the A or 
Afull test, whichever applies.
    (4) Determine heating seasonal performance factor 2 (HSPF2) as

[[Page 24264]]

described in sections 2 and 4 of appendix M1 to this subpart or 
seasonal heating and off-mode rating efficiency (SHORE) as described in 
sections 2 and 3 of appendix M2 to this subpart, and round off to the 
nearest 0.025 Btu/W-h.
    (5) Determine average off mode power consumption as described in 
section 3 of appendix M1 to this subpart, and round off to the nearest 
0.5 W. Average off mode power consumption is not required when testing 
in accordance with appendix M2 to this subpart.
    (6) Determine all other measures of energy efficiency or 
consumption or other useful measures of performance using appendix M1 
or M2 of this subpart.
* * * * *
0
9. Appendix M1 to subpart B of part 430 is revised to read as follows:

Appendix M1 to Subpart B of Part 430--Uniform Test Method for Measuring 
the Energy Consumption of Central Air Conditioners and Heat Pumps

    Note: Prior to [Date 180 days after publication of the final 
rule in the Federal Register], representations with respect to the 
energy use or efficiency of central air conditioners and heat pumps, 
including compliance certifications, must be based on testing 
conducted in accordance with:
    (a) Appendix M1 to this subpart, in the 10 CFR parts 200 through 
499 edition revised as of January 1, 2023; or
    (b) This appendix.
    Beginning [Date 180 days after publication of the final rule in 
the Federal Register], and prior to the compliance date of amended 
standards for central air conditioners and heat pumps based on 
Seasonal Cooling and Off-mode Rating Efficiency (SCORE) and Seasonal 
Heating and Off-mode Rating Efficiency (SHORE), representations with 
respect to energy use or efficiency of central air conditioners and 
heat pumps, including compliance certifications, must be based on 
testing conducted in accordance with this appendix.
    Beginning on the compliance date of amended standards for 
central air conditioners and heat pumps based on SCORE and SHORE, 
representations with respect to energy use or efficiency of central 
air conditioners and heat pumps, including compliance 
certifications, must be based on testing conducted in accordance 
with appendix M2 to this subpart.
    Manufacturers may also certify compliance with any amended 
energy conservation standards for central air conditioners and heat 
pumps based on SCORE or SHORE prior to the applicable compliance 
date for those standards, and those compliance certifications must 
be based on testing in accordance with appendix M2 to this subpart.

1. Incorporation by Reference

    In Sec.  430.3, DOE incorporated by reference the entire 
standard for AHRI 210/240-202X, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-
2009 and ANSI/ASHRAE 116-2010. However, certain enumerated 
provisions of AHRI 210/240-202X, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 
37-2009 and ANSI/ASHRAE 116-2010, as set forth in sections 1.1 
through 1.4 of this appendix, are inapplicable. To the extent there 
is a conflict between the terms or provisions of a referenced 
industry standard and the CFR, the CFR provisions control.

1.1 AHRI 210/240-202X

    (a) Section 1 Purpose is inapplicable,
    (b) Section 2 Scope is inapplicable,
    (c) The following subsections of Section 3 Definitions are 
inapplicable: 3.2.15 (Double-duct system), 3.2.19 (Gross capacity), 
3.2.47 (Oil Recovery Mode), 3.2.52 (Published Rating), 3.2.64 
(Standard Filter), 3.2.79 (Unitary Air-conditioner), 3.2.80 (Unitary 
Heat Pump),
    (d) Section 4 Classifications is inapplicable,
    (e) The following subsections of Section 6 Rating Requirements 
are inapplicable: 6.1.8, 6.2, 6.3, 6.4 and 6.5,
    (f) Section 7 Minimum Data Requirements for Published Ratings is 
inapplicable,
    (g) Section 8 Operating Requirements is inapplicable,
    (h) Section 9 Marking and Nameplate Data is inapplicable,
    (i) Section 10 Conformance Conditions is inapplicable,
    (j) Appendix A References--Normative is inapplicable,
    (k) Appendix B References--Informative is inapplicable,
    (l) Appendix C Secondary Capacity Check Requirements--Normative 
is inapplicable,
    (m) Appendix F Unit Configurations for Standard Efficiency 
Determination--Normative is inapplicable,
    (n) Appendix H Verification Testing--Normative is inapplicable,
    (o) Appendix I Controls Verification Procedure--Normative is 
inapplicable, and
    (p) Appendix J Determination of Cut in and Cut out 
temperatures--Normative is inapplicable,

1.2 ANSI/ASHRAE 37-2009

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.3 ANSI/ASHRAE 16-2016

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.4 ANSI/ASHRAE 116-2010

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable,
    (c) Section 4--Classification is inapplicable,
    (d) Section 7--Methods of Test is inapplicable,
    (e) References is inapplicable,
    (f) Appendix A--Example Bin Calculations is inapplicable, and
    (g) Appendix B--Bibliography is inapplicable.

2. General

    Determine the cooling capacity, heating capacity, and applicable 
energy efficiency metrics (SEER2, HSPF2, and EER2) in accordance 
with the specified sections of AHRI 210/240-202X and the applicable 
provisions of ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ANSI/
ASHRAE 116-2010. The AFull (cooling mode) and 
H1, Full or H1, Nom (heating mode, if 
applicable) shall have a secondary capacity check completed. For all 
other tests in each mode, it is permissible to not use a secondary 
capacity check.
    Sections 3, 4, and 5 of this appendix provide additional 
instructions for testing. In cases where there is a conflict, the 
language of this appendix takes highest precedence, followed, in 
order, by: AHRI 210/240-202X, ANSI/ASHRAE 37-2009, ANSI/ASHRAE 16-
2016 and ANSI/ASHRAE 116-2010. 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 notice of any change in 
the incorporation will be published in the Federal Register.

3. Off-Mode Power

    Determine off-mode power, PW, OFF, in accordance with 
section 11.3 and appendix G of AHRI 210/240-202X.

4. Outdoor Units With No Match (OUWNM)

4.1 Definition

    An Outdoor Unit that is not distributed in commerce with any 
indoor units, that meets any of the following criteria:
    (a) Is designed for use with a refrigerant that makes the unit 
banned for installation when paired with an Indoor Unit as a system, 
according to EPA regulations in 40 CFR chapter I, subchapter C,
    (b) Is designed for use with a refrigerant that has a 95 [deg]F 
midpoint saturation absolute pressure that is 18 percent 
of the 95 [deg]F saturation absolute pressure for R-22, or
    (c) Is shipped without a specified refrigerant from the point of 
manufacture or is shipped such that more than two pounds of 
refrigerant are required to meet the charge per section 5.1.8 of 
AHRI 210/240-202X. This shall not apply if either:
    (1) The factory charge is equal to or greater than 70% of the 
outdoor unit internal volume times the liquid density of refrigerant 
at 95 [deg]F, or
    (2) An A2L refrigerant is approved for use and listed in the 
certification report.

4.2 Testing

    An OUWNM shall be tested with an indoor coil having nominal tube 
diameter of 0.375 in and an NGIFS of 1.0 or less (as determined in 
section 5.1.6.3 of AHRI 210/240-202X).

5. Test Conditions

5.1 Test Conditions for Certifying Compliance With Standards

    The following conditions specified in AHRI 210/240-202X apply 
when testing to certify to the SEER2 and HSPF2 energy conservation 
standards in Sec.  430.32(c).

[[Page 24265]]

    For cooling mode, use the rating conditions specified in table 8 
of AHRI 210/240-202X and the fractional cooling bin hours in table 
15 of AHRI 210/240-202X to determine SEER2, and EER2 for models 
subject to regional standards in terms of EER2.
    For heat pump heating mode, use the rating conditions specified 
in table 8 of AHRI 210/240-202X and the fractional heating bin hours 
specified for Region IV in table 16 of AHRI 210/240-202X to 
determine the heating efficiency metric, HSPF2.

5.2 Optional Representations

    Representations of EER2 made using the rating conditions 
specified in Table 8 of AHRI 210/240-202X are optional for models 
not subject to regional standards in terms of EER2. Representations 
of HSPF2 made using the rating conditions specified in table 8 of 
AHRI 210/240-202X and the fractional heating hours specified for 
Regions other than Region IV in Table 14 AHRI 210/240-202X are 
optional. Representations of COPpeak made using appendix 
K are optional.
0
10. Appendix M2 to subpart B of part 430 is added to read as follows:

Appendix M2 to Subpart B of Part 430--Uniform Test Method for Measuring 
the Energy Consumption of Central Air Conditioners and Heat Pumps

    Note: Prior to [Date 180 days after publication of the final 
rule in the Federal Register], representations with respect to the 
energy use or efficiency of central air conditioners and heat pumps, 
including compliance certifications, must be based on testing 
conducted in accordance with:
    (a) Appendix M1 to this subpart, in the 10 CFR parts 200 through 
499 edition revised as of January 1, 2023; or
    (b) Appendix M1 to this subpart.
    Beginning [Date 180 days after publication of the final rule in 
the Federal Register], and prior to the compliance date of amended 
standards for central air conditioners and heat pumps based on 
Seasonal Cooling and Off-mode Rating Efficiency (SCORE) and Seasonal 
Heating and Off-mode Rating Efficiency (SHORE), representations with 
respect to energy use or efficiency of central air conditioners and 
heat pumps, including compliance certifications, must be based on 
testing conducted in accordance with appendix M1 to this subpart.
    Beginning on the compliance date of amended standards for 
central air conditioners and heat pumps based on SCORE and SHORE, 
representations with respect to energy use or efficiency of central 
air conditioners and heat pumps, including compliance 
certifications, must be based on testing conducted in accordance 
with this appendix.
    Manufacturers may also certify compliance with any amended 
energy conservation standards for central air conditioners and heat 
pumps based on SCORE or SHORE prior to the applicable compliance 
date for those standards, and those compliance certifications must 
be based on testing in accordance with this appendix.

1. Incorporation by Reference

    In Sec.  430.3, DOE incorporated by reference the entire 
standard for AHRI 1600-202X, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-
2009, and ANSI/ASHRAE 116-2010. However, certain enumerated 
provisions of AHRI 1600-202X, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-
2009, and ANSI/ASHRAE 116-2010, as set forth in sections 1.1 through 
1.4 of this appendix, are inapplicable. To the extent there is a 
conflict between the terms or provisions of a referenced industry 
standard and the CFR, the CFR provisions control.

1.1. AHRI 1600-202X

    (a) Section 1 Purpose is inapplicable,
    (b) Section 2 Scope is inapplicable,
    (c) The following subsections of Section 3 Definitions are 
inapplicable: 3.1.15 (Double-duct system), 3.1.19 (Gross capacity), 
3.1.47 (Oil Recovery Mode), 3.1.52 (Published Rating), 3.1.65 
(Standard Filter), 3.1.80 (Unitary Air-conditioner), 3.1.81 (Unitary 
Heat Pump),
    (d) Section 4 Classifications is inapplicable,
    (e) The following subsections of Section 6 Rating Requirements 
are inapplicable: 6.1.8, 6.2, 6.3, 6.4 and 6.5
    (f) Section 7 Minimum Data Requirements for Published Ratings is 
inapplicable,
    (g) Section 8 Operating Requirements is inapplicable,
    (h) Section 9 Marking and Nameplate Data is inapplicable,
    (i) Section 10 Conformance Conditions is inapplicable,
    (j) Appendix A References--Normative is inapplicable,
    (k) Appendix B References--Informative is inapplicable,
    (l) Appendix C Secondary Capacity Check Requirements--Normative 
is inapplicable,
    (m) Appendix F Unit Configurations for Standard Efficiency 
Determination--Normative is inapplicable,
    (n) Appendix H Verification Testing--Normative is inapplicable,
    (o) Appendix I Controls Verification Procedure--Normative is 
inapplicable,
    (p) Appendix J Determination of Cut in and Cut out 
temperatures--Normative is inapplicable, and
    (q) Appendix M Outdoor Temperature Bin Hours--Informative is 
inapplicable.

1.2. ANSI/ASHRAE 37-2009

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.3. ANSI/ASHRAE 16-2016

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.4. 1.4. ANSI/ASHRAE 116-2010

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable,
    (c) Section 4--Classification is inapplicable,
    (d) Section 7--Methods of Test is inapplicable,
    (e) References is inapplicable,
    (f) Appendix A--Example Bin Calculations is inapplicable, and
    (g) Appendix B--Bibliography is inapplicable.

2. General

    Determine the applicable energy efficiency metrics (SCORE, 
SHORE, and EER2) in accordance with the specified sections of AHRI 
1600-202X and the applicable provisions of ANSI/ASHRAE 16-2016, 
ANSI/ASHRAE 37-2009, and ANSI/ASHRAE 116-2010. The AFull 
(cooling mode) and H1, Full or H1, Nom 
(heating mode, if applicable) shall have a secondary capacity check 
completed. For all other tests in each mode, it is permissible to 
not use a secondary capacity check. Sections 3 and 4 of this 
appendix provide additional instructions for testing. In cases where 
there is a conflict, the language of this appendix takes highest 
precedence, followed, in order, by: AHRI 1600-202X, ANSI/ASHRAE 37-
2009, ANSI/ASHRAE 16-2016, and ANSI/ASHRAE 116-2010. 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 notice 
of any change in the incorporation will be published in the Federal 
Register.

3. Outdoor Units With No Match (OUWNM)

3.1 Definition

    An Outdoor Unit that is not distributed in commerce with any 
indoor units, that meets any of the following criteria:
    (a) Is designed for use with a refrigerant that makes the unit 
banned for installation when paired with an Indoor Unit as a system, 
according to EPA regulations in 40 CFR chapter I, subchapter C,
    (b) Is designed for use with a refrigerant that has a 95 [deg]F 
midpoint saturation absolute pressure that is 18 percent 
of the 95 [deg]F saturation absolute pressure for R-22, or
    (c) Is shipped without a specified refrigerant from the point of 
manufacture or is shipped such that more than two pounds of 
refrigerant are required to meet the charge per section 5.1.8 of 
AHRI 1600-202X. This shall not apply if either:
    (1) The factory charge is equal to or greater than 70% of the 
outdoor unit internal volume times the liquid density of refrigerant 
at 95 [deg]F or,
    (2) An A2L refrigerant is approved for use and listed in the 
certification report.

3.2 Testing

    An OUWNM shall be tested with an indoor coil having nominal tube 
diameter of 0.375 in and an NGIFS of 1.0 or less (as determined in 
section 5.1.6.3 of AHRI 1600-202X).

4. Test Conditions

4.1 Test Conditions for Certifying Compliance With Standards

    The following conditions specified in AHRI 1600-202X apply when 
testing to certify to the SCORE and SHORE energy conservation 
standards, in Sec.  431.97.
    For cooling mode, use the rating conditions specified in table 8 
of AHRI 1600-202X and

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the `U.S. National Average' cooling conditioning hours and shoulder 
season hours in Table 15 of AHRI 1600-202X, to determine SCORE, and 
EER2 for models subject to regional standards in terms of EER2.
    For heat pump heating mode, use the rating conditions specified 
in Table 8 of AHRI 1600-202X and the `U.S. National Average' heating 
conditioning hours and shoulder season hours specified in Table 18 
of AHRI 1600-202X to determine the heating efficiency metric, SHORE.

4.2 Optional Representations

    Representations of EER2 made using the rating conditions 
specified in Table 8 of AHRI 1600-202X are optional for models not 
subject to regional standards in terms of EER2. Representations of 
SHORE made using the rating conditions specified in Table 8 of AHRI 
1600-202X and the `Cold Climate Average' heating conditioning hours 
and shoulder season hours in Table 18 of AHRI 1600-202X are 
optional. Representations of COPpeak made using appendix 
K are optional.

[FR Doc. 2024-04784 Filed 4-4-24; 8:45 am]
BILLING CODE 6450-01-P