Home/Federal/Federal Register/2024-04784

Proposed Rule2024-04784

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

Primary source

Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.

Published

April 5, 2024

Issuing agencies

Energy Department

Abstract

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.

Full Text

<html>
<head>
<title>Federal Register, Volume 89 Issue 67 (Friday, April 5, 2024)</title>
</head>
<body><pre>
[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-04784]

[[Page 24205]]

Vol. 89

Friday,

No. 67

April 5, 2024

Part III

Department of Energy

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

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]]

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

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.

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

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 <a href="http://www.regulations.gov">www.regulations.gov</a> 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: <a href="/cdn-cgi/l/email-protection#a2e1e3e1c3ccc6eac7c3d6f2d7cfd290929090f6f29292909ae2c7c78cc6cdc78cc5cdd4">[email&#160;protected]</a>. 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 <a href="http://www.regulations.gov">www.regulations.gov</a>. All
documents in the docket are listed in the <a href="http://www.regulations.gov">www.regulations.gov</a> 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 <a href="http://www.regulations.gov/docket/EERE-2022-BT-TP-0028">www.regulations.gov/docket/EERE-2022-BT-TP-0028</a>. 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
<a href="http://www.regulations.gov">www.regulations.gov</a>.

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: <a href="/cdn-cgi/l/email-protection#febf8e8e92979f909d9bad8a9f909a9f8c9a8daf8b9b8d8a9791908dbe9b9bd09a919bd0999188">[email&#160;protected]</a>.
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: <a href="/cdn-cgi/l/email-protection#1464716071663a777b777c66757a547c653a707b713a737b62">[email&#160;protected]</a>.
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:
<a href="/cdn-cgi/l/email-protection#4a0b3a3a26232b24292f193e2b242e2b382e391b3f2f393e232524390a2f2f642e252f642d253c">[email&#160;protected]</a>.

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.
---------------------------------------------------------------------------

\1\ Public review of AHRI 210/240-202X Draft was announced in
the November 16, 2023 AHRI Update here: <a href="http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html">http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html</a>.
---------------------------------------------------------------------------

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.
---------------------------------------------------------------------------

\2\ Public review of AHRI 1600-202X Draft was also announced in
the November 16, 2023 AHRI Update here: <a href="http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html">http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html</a>.
---------------------------------------------------------------------------

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
<a href="http://www.ashrae.org/resources--publications">www.ashrae.org/resources--publications</a>.
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, COP<INF>peak</INF>
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))
---------------------------------------------------------------------------

\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.
---------------------------------------------------------------------------

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))
---------------------------------------------------------------------------

\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).
---------------------------------------------------------------------------

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.
----------------------------------------------------------------------------------------------------------------

A parenthetical reference at the end of a comment quotation or
paraphrase provides the location of the item in the public record.\7\
---------------------------------------------------------------------------

\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 <a href="http://www.regulations.gov">www.regulations.gov</a>). The references are arranged
as follows: (commenter name, comment docket ID number, page of that
document).
---------------------------------------------------------------------------

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 <a href="http://www.ahrinet.org">www.ahrinet.org</a>.
\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 <a href="http://www.ahrinet.org">www.ahrinet.org</a>.
---------------------------------------------------------------------------

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 <a href="http://www.amca.org/store/index.php">www.amca.org/store/index.php</a>.
\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 <a href="http://www.ahrinet.org">www.ahrinet.org</a>.
\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 <a href="http://www.ashrae.org/resources--publications">www.ashrae.org/resources--publications</a>.
---------------------------------------------------------------------------

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 (``COP<INF>peak</INF>''), 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, P<INF>W,OFF</INF>.
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, COP<INF>peak</INF>, 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: <a href="http://wwwcsagroup.org/store/product/CSA%20SPE-07:23/">wwwcsagroup.org/store/product/CSA%20SPE-07:23/</a>.
---------------------------------------------------------------------------

(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
<a href="http://www.iea-4e.org/wp-content/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf">www.iea-4e.org/wp-content/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf</a>.
\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:
<a href="http://www.iea-4e.org/wpcontent/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf">www.iea-4e.org/wpcontent/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf</a>.
---------------------------------------------------------------------------

(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 <a href="http://www.tandfonline.com/doi/full/10.1080/23744731.2016.1274628">www.tandfonline.com/doi/full/10.1080/23744731.2016.1274628</a>.
\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 <a href="http://www.energystar.gov/products/spec/central_air_conditioner_and_air_source_heat_pump_specification_version_6_0_pd">www.energystar.gov/products/spec/central_air_conditioner_and_air_source_heat_pump_specification_version_6_0_pd</a>.
\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 <a href="http://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/electricity-alternative-energy/energy-efficiency/18-00072-nrcan-road-map-eng.pdf">www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/electricity-alternative-energy/energy-efficiency/18-00072-nrcan-road-map-eng.pdf</a>.
\31\ NYSERDA referred to pages 20, 25, and 26 of the Vancouver
Energy Commission's BC Heat Pump Technology Attraction Strategy,
available at <a href="http://vancouvereconomic.com/wp-content/uploads/2022/11/11-2022-BC-Heat-Pump-Strategy-Report-Web-1.1.pdf">vancouvereconomic.com/wp-content/uploads/2022/11/11-2022-BC-Heat-Pump-Strategy-Report-Web-1.1.pdf</a>.
\32\ NYSERDA referred to page 14 of the ``Advanced Heat Pump
White paper,'' available at <a href="http://www.mwalliance.org/sites/default/files/media-document/Advanced%20HP%20Whitepaper%20v1.13.pdf">www.mwalliance.org/sites/default/files/media-document/Advanced%20HP%20Whitepaper%20v1.13.pdf</a>.
---------------------------------------------------------------------------

(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 <a href="http://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">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</a>.
---------------------------------------------------------------------------

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

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
<a href="http://docs.lib.purdue.edu/iracc/689/">docs.lib.purdue.edu/iracc/689/</a>.
---------------------------------------------------------------------------

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 <a href="http://docs.lib.purdue.edu/iracc/2012">docs.lib.purdue.edu/iracc/2012</a>.
---------------------------------------------------------------------------

(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 <a href="http://www.regulations.gov/document/EERE-2022-BT-STD-0015-0065">www.regulations.gov/document/EERE-2022-BT-STD-0015-0065</a>.
---------------------------------------------------------------------------

(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 <a href="http://www.ahrinet.org/system/files/2023-06/AHRI_Standard_1230-2021.pdf">www.ahrinet.org/system/files/2023-06/AHRI_Standard_1230-2021.pdf</a>.
\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 <a href="http://www.energy.gov/sites/default/files/2021-10/bto-cchp-tech-challenge-spec-102521.pdf">www.energy.gov/sites/default/files/2021-10/bto-cchp-tech-challenge-spec-102521.pdf</a>.
\47\ As an example, if a heating capacity of 18,000 Btu/h was
measured during the H1<INF>1</INF> 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 H3<INF>2</INF> and H4<INF>2</INF>. (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
H1<INF>1</INF> (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
H3<INF>2</INF> 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 <a href="http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=3455&context=iracc">docs.lib.purdue.edu/cgi/viewcontent.cgi?article=3455&context=iracc</a>.
\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
F<INF>low</INF> test, and the target SHR from the F<INF>low</INF>
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 H4<INF>full</INF>
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
(H1<INF>Full</INF> or H1<INF>Nom</INF>).
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 H3<INF>2</INF> and H1<INF>2</INF> 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, H4<INF>2</INF>, or
H4<INF>3</INF> 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 F<INF>Low</INF> (at 67 [deg]F) and
H1<INF>Low</INF> (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 H4<INF>2</INF> 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 H4<INF>2</INF> 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 H4<INF>2</INF> 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 <a href="http://canadagazette.gc.ca/rp-pr/p2/2022/2022-12-21/html/sor-dors265-eng.html">canadagazette.gc.ca/rp-pr/p2/2022/2022-12-21/html/sor-dors265-eng.html</a>.
---------------------------------------------------------------------------

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 H4<INF>full</INF>
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, H4<INF>2</INF>, or
H4<INF>3</INF> 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 (``H1<INF>N</INF> capacity'') provided little
incentive to design for good heat pump performance, since low
H1<INF>N</INF> 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
<a href="http://www.eia.gov/consumption/residential/data/2020/hc/pdf/HC%206.8.pdf">www.eia.gov/consumption/residential/data/2020/hc/pdf/HC%206.8.pdf</a>.
\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 <a href="http://publications.gc.ca/collections/collection_2021/rncan-nrcan/M154-138-2020-eng.pdf">publications.gc.ca/collections/collection_2021/rncan-nrcan/M154-138-2020-eng.pdf</a>.
\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 <a href="http://neep.org/sites/default/files/resources/ASHP%20Sizing%20%26%20Selecting%20-%208x11_edits.pdf">neep.org/sites/default/files/resources/ASHP%20Sizing%20%26%20Selecting%20-%208x11_edits.pdf</a>.
\59\ See <a href="http://cleanheat.ny.gov/contractor-resources/">cleanheat.ny.gov/contractor-resources/</a>.
\60\ See <a href="http://cchrc.org/media/2020-Juneau-DHP-Survey-Final1.pdf">cchrc.org/media/2020-Juneau-DHP-Survey-Final1.pdf</a>.
---------------------------------------------------------------------------

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, COP<INF>peak</INF>
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
(``COP<INF>peak</INF>''), intended to provide an indication of total
heating efficiency as applied under peak heating load conditions.
Specifically, COP<INF>peak</INF> 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 H4<INF>Full</INF> test, and
Full is the space heating capacity of the heat pump during the
H4<INF>Full</INF> test.
COP<INF>peak</INF> 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, COP<INF>peak</INF> 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 COP<INF>peak</INF> 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
COP<INF>peak</INF> would allow for representative characterizations of
HP performance at low ambient temperatures. Therefore, DOE is proposing
to incorporate by reference COP<INF>peak</INF> 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 <a href="http://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">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</a>.
---------------------------------------------------------------------------

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:
<bullet> Outdoor air temperature (``OAT'') is measured using an
outdoor coil air sampler.
<bullet> Start at an OAT above but close to cut-out temperature.
<bullet> Ramp down OAT temperature at 1 [deg]F per 5 minutes.
<bullet> Wait for 5 minutes once unit shuts off. Cut-out
temperature is the measured temperature with the unit turned off.
<bullet> Reverse temperature ramp and increase the temperature by 1
[deg]F per 5 minutes.
<bullet> 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.,
T<INF>off</INF> and T<INF>on</INF> 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 T<INF>off</INF> 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: <a href="http://www.epa.gov/ozone/snap/">www.epa.gov/ozone/snap/</a>.
\71\ List of EPA SNAP program-approved refrigerant substitutes
is available at <a href="http://www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps">www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps</a>.
\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
<a href="http://www.techstreet.com/ashrae/standards/ashrae-15-2016-packaged-w-34-2016?product_id=1938420">www.techstreet.com/ashrae/standards/ashrae-15-2016-packaged-w-34-2016?product_id=1938420</a>.
---------------------------------------------------------------------------

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

[…truncated; see source link]

View on FederalRegister.gov →Plain-text source

Indexed from Federal Register on April 5, 2024.

This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.