[Federal Register Volume 88, Number 187 (Thursday, September 28, 2023)]
[Proposed Rules]
[Pages 66710-66722]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-21190]


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Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 88, No. 187 / Thursday, September 28, 2023 / 
Proposed Rules

[[Page 66710]]


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DEPARTMENT OF ENERGY

10 CFR Part 431

[EERE-2017-BT-STD-0009]
RIN 1905-AD79


Energy Conservation Program: Energy Conservation Standards for 
Walk-In Coolers and Freezers

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

ACTION: Notification of data availability regarding energy conservation 
standards.

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SUMMARY: On September 5, 2023, the U.S. Department of Energy (``DOE'') 
published a notice of proposed rulemaking (``NOPR''), in which DOE 
proposed amended energy conservation standards for walk-in coolers and 
walk-in freezers. (``September 2023 NOPR'') In this notification, DOE 
is summarizing and addressing comments that were considered but not 
discussed in the September 2023 NOPR.

DATES: 
    Comments: DOE will accept comments, data, and information regarding 
the September 2023 NOPR as supplemented by this notice of data 
availability no later than November 6, 2023.
    Meeting: DOE is holding a public meeting regarding the September 
2023 NOPR via webinar on Wednesday, September 27, 2023, from 1:00 p.m. 
to 4:00 p.m. See section IV, ``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 
regarding the September 2023 NOPR as supplemented by this notice of 
data availability using the Federal eRulemaking Portal at 
www.regulations.gov under docket number EERE-2017-BT-STD-0009. Follow 
the instructions for submitting comments. Alternatively, interested 
persons may submit comments, identified by docket number EERE-2017-BT-
STD-0009, by any of the following methods:
    Email: <a href="/cdn-cgi/l/email-protection#6e39272d285c5e5f593d3a2a5e5e5e572e0b0b400a010b40090118"><span class="__cf_email__" data-cfemail="5b0c12181d696b6a6c080f1f6b6b6b621b3e3e753f343e753c342d">[email protected]</span></a>. Include the docket number EERE-
2017-BT-STD-0009 in the subject line of the message.
    Non-electronic submissions: Please contact (202) 287-1445 for 
instructions if an electronic copy cannot be submitted.
    No telefacsimiles (``faxes'') will be accepted. For detailed 
instructions on submitting comments and additional information on this 
process, see section IV of this document.
    Docket: The docket for this activity, which includes Federal 
Register notices, comments, and other supporting documents/materials, 
is available for review at www.regulations.gov. All documents in the 
docket are listed in the www.regulations.gov index. However, not all 
documents listed in the index may be publicly available, such as 
information that is exempt from public disclosure.
    The docket web page can be found at www.regulations.gov/docket/EERE-2017-BT-STD-0009. The docket web page contains instructions on how 
to access all documents, including public comments, in the docket. See 
section IV of this document for information on how to submit comments 
through www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: 
    Mr. Troy Watson, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, EE-5B, 
1000 Independence Avenue SW, Washington, DC 20585-0121. Email: 
<a href="/cdn-cgi/l/email-protection#d998a9a9b5b0b8b7babc8aadb8b7bdb8abbdaa88acbcaaadb0b6b7aa99bcbcf7bdb6bcf7beb6af"><span class="__cf_email__" data-cfemail="d190a1a1bdb8b0bfb2b482a5b0bfb5b0a3b5a280a4b4a2a5b8bebfa291b4b4ffb5beb4ffb6bea7">[email protected]</span></a>.
    Mr. Matthew Schneider, U.S. Department of Energy, Office of the 
General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 
20585-0121. Telephone: (240) 597-6265. Email: 
<a href="/cdn-cgi/l/email-protection#92fff3e6e6faf7e5bce1f1fafcf7fbf6f7e0d2fae3bcf6fdf7bcf5fde4"><span class="__cf_email__" data-cfemail="a3cec2d7d7cbc6d48dd0c0cbcdc6cac7c6d1e3cbd28dc7ccc68dc4ccd5">[email protected]</span></a>.
    For further information on how to submit a comment, review other 
public comments and the docket, or participate in the public meeting, 
contact the Appliance and Equipment Standards Program staff at (202) 
287-1445 or by email: <a href="/cdn-cgi/l/email-protection#d998a9a9b5b0b8b7babc8aadb8b7bdb8abbdaa88acbcaaadb0b6b7aa99bcbcf7bdb6bcf7beb6af"><span class="__cf_email__" data-cfemail="abeadbdbc7c2cac5c8cef8dfcac5cfcad9cfd8fadeced8dfc2c4c5d8ebcece85cfc4ce85ccc4dd">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background
II. Discussion
    A. General
    B. Market and Technology Assessment
    C. Engineering Analysis
    a. Display Doors
    b. Refrigeration Systems
    D. Life-Cycle Cost and Payback Period Analysis
    1. Consumer Sample
    2. Equipment Lifetime
    E. Conclusion
III. Procedural Issues and Regulatory Review
IV. Public Participation
V. Approval of the Office of the Secretary

I. Background

    The Energy Policy and Conservation Act, Public Law 94-163, as 
amended (``EPCA''),\1\ authorizes DOE to regulate the energy efficiency 
of a number of consumer products and certain industrial equipment. (42 
U.S.C. 6291-6317) Title III, Part C of EPCA,\2\ established the Energy 
Conservation Program for Certain Industrial Equipment. (42 U.S.C. 6311-
6317) Such equipment includes walk-in coolers and walk-in freezers \3\ 
(hereafter referred to as ``walk-ins'' or ``WICFs''), the subject of 
this notification.
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    \1\ All references to EPCA in this document refer to the statute 
as amended through the Energy Act of 2020, Public Law 116-260 (Dec. 
27, 2020), which reflect the last statutory amendments that impact 
Parts A and A-1 of EPCA.
    \2\ For editorial reasons, upon codification in the U.S. Code, 
Part C was re-designated Part A-1.
    \3\ Walk-in coolers and walk-in freezers are defined as an 
enclosed storage space, including but not limited to panels, doors, 
and refrigeration systems, refrigerated to temperatures, 
respectively, above, and at or below 32 degrees Fahrenheit that can 
be walked into, and has a total chilled storage area of less than 
3,000 square feet; however, the terms do not include products 
designed and marketed exclusively for medical, scientific, or 
research purposes. 10 CFR 431.302.
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    The current energy conservation standards for walk-ins are set 
forth in DOE's regulations at 10 CFR 431.306. Rather than establishing 
standards for complete walk-in systems, DOE has established standards 
for the principal components that make up a walk-in (i.e., doors, 
panels, and refrigeration systems). The current energy conservation 
standards for walk-in doors are in terms of maximum daily energy 
consumption, which is measured in kWh/day (see Table I.1). The current 
energy conservation standards for walk-in panels are in terms of R-
value, which

[[Page 66711]]

is measured in h-ft\2\-[deg]F/Btu (see Table I.2). The current energy 
conservation standards for refrigeration systems are in terms of annual 
walk-in energy factor (``AWEF''), which is measured in Btu/(W-h) (see 
Table I.3).

         Table I.1--Federal Energy Conservation Standards for Walk-In Coolers and Walk-In Freezer Doors
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                                                           Equations for maximum daily energy consumption (kWh/
                    Equipment class                                                day)
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Display door, medium-temperature.......................  0.04 x Add + 0.41.
Display door, low-temperature..........................  0.15 x Add + 0.29.
Passage door, medium-temperature.......................  0.05 x And + 1.7.
Passage door, low-temperature..........................  0.14 x And + 4.8.
Freight door, medium-temperature.......................  0.04 x And + 1.9.
Freight door, low-temperature..........................  0.12 x And + 5.6.
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Add or And = surface area of the display door or non-display door, respectively, expressed in ft\2\, as
  determined in appendix A to subpart R of 10 CFR part 431.


Table I.2--Federal Energy Conservation Standards for Walk-In Coolers and
                         Walk-In Freezer Panels
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                                                     Minimum R-value (h-
                  Equipment class                     ft\2\-[deg]F/Btu)
------------------------------------------------------------------------
Wall or ceiling panels, medium-temperature........                    25
Wall or ceiling panels, low-temperature...........                    32
Floor panels, low-temperature.....................                    28
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 Table I.3--Federal Energy Conservation Standards for Walk-In Coolers and Walk-In Freezer Refrigeration Systems
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                    Equipment class                                       Minimum AWEF (Btu/W-h)
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Dedicated condensing system, medium-temperature, indoor  5.61.
Dedicated condensing system, medium-temperature,         7.60.
 outdoor.
Dedicated condensing system, low-temperature, indoor     9.091 x 10-\5\ x qnet + 1.81.
 with a net capacity (qnet) of <6,500 British thermal
 units per hour (``Btu/h'').
Dedicated condensing system, low-temperature, indoor     2.40.
 with a net capacity (qnet) of >=6,500 Btu/h.
Dedicated condensing system, low-temperature, outdoor    6.522 x 10-\5\ x qnet + 2.73.
 with a net capacity (qnet) of <6,500 Btu/h.
Dedicated condensing system, low-temperature, outdoor    3.15.
 with a net capacity (qnet) of >=6,500 Btu/h.
Unit cooler, medium-temperature........................  9.00.
Unit cooler, low-temperature, indoor with a net          1.575 x 10-\5\ x qnet + 3.91.
 capacity (qnet) of <15,500 Btu/h.
Unit cooler, low-temperature, indoor with a net          4.15.
 capacity (qnet) of >=15,500 Btu/h.
----------------------------------------------------------------------------------------------------------------
Where qnet is net capacity as determined in accordance with 10 CFR 431.304 and certified in accordance with 10
  CFR part 429.

    To evaluate whether to propose amendments to the energy 
conservation standards for walk-ins, DOE issued a request for 
information (``RFI'') in the Federal Register on July 16, 2021 (``July 
2021 RFI''). 86 FR 37687. In the July 2021 RFI, DOE sought data, 
information, and comment pertaining to walk-ins. 86 FR 37687, 37689. 
DOE subsequently announced the availability of the preliminary analysis 
it had conducted for the purpose of evaluating the need for amending 
the current energy conservation standards for walk-ins in the Federal 
Register on June 30, 2022, (``June 2022 Preliminary Analysis''). The 
analysis was set forth in the Department's accompanying preliminary 
technical support document (``TSD''). The June 2022 Preliminary 
Analysis summarized and addressed the comments received in response to 
the July 2021 RFI in chapter 2 of the June 2022 Preliminary Analysis 
TSD. DOE held a public meeting via webinar to discuss and receive 
comment on the June 2022 Preliminary Analysis on July 22, 2022. The 
meeting covered the analytical framework, models, and tools that DOE 
used to evaluate potential standards; the results of the preliminary 
analyses performed by DOE; the potential energy conservation standard 
levels derived from those analyses; and other relevant issues.
    In a test procedure final rule published May 4, 2023 (``May 2023 TP 
Final Rule''), DOE amended the test procedures for walk-in components. 
DOE also established a new appendix, appendix C1 to subpart R 
(``appendix C1''), and a new energy metric, AWEF2, for refrigeration 
systems. (See 88 FR 28780 and 10 CFR part 431, subpart R, appendix C1.) 
Manufacturers would be required to begin using appendix C1 as of the 
compliance date of an energy conservation standards promulgated as a 
result of this rulemaking.
    On September 5, 2023, DOE published a notice of proposed rulemaking 
in the Federal Register, regarding energy conservation standards for 
walk-in coolers and freezers (``September 2023 NOPR''). 88 FR 60746. 
Specifically, DOE proposed amended standards for walk-in non-display 
doors and walk-in refrigeration systems based on the amended or new 
test procedures adopted in the May 2023 TP Final Rule. For 
refrigeration systems, DOE proposed amended standards in terms of the 
AWEF2 metric based on appendix C1. The September 2023 NOPR summarized 
and addressed comments received in response to the

[[Page 66712]]

June 2022 Preliminary Analysis. However, comments from one interested 
party, listed in Table I.4 of this document, were considered in 
developing the September 2023 NOPR, but were not summarized and 
discussed in the NOPR.

          Table I.4--June 2022 Preliminary Analysis Written Comments Omitted in the September 2023 NOPR
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                                                                     Comment number
             Commenter(s)                       Abbreviation          in the docket         Commenter type
----------------------------------------------------------------------------------------------------------------
Pacific Gas and Electric Company,       CA IOUs....................              43  Utilities.
 Southern California Gas Company, San
 Diego Gas and Electric, and Southern
 California Edison; (collectively
 referred to as the ``California
 Investor-Owned Utilities'').
----------------------------------------------------------------------------------------------------------------

    A parenthetical reference at the end of a comment quotation or 
paraphrase provides the location of the item in the public record.\4\
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    \4\ The parenthetical reference provides a reference for 
information located in the docket of DOE's rulemaking to develop 
energy conservation standards for walk-ins. (Docket No. EERE-2017-
BT-STD-0009, which is maintained at www.regulations.gov). The 
references are arranged as follows: (commenter name, comment docket 
ID number, page of that document).
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    DOE notes that it also received comments in response to the June 
2022 Preliminary Analysis in the form of confidential business 
information from two stakeholders, which have been restricted on the 
public docket.\5\ To the extent that these stakeholders provided 
confidential information, DOE did not address those comments directly 
due to the confidential nature of the comments received. However, DOE 
considered these confidential comments in its analysis presented in the 
September 2023 NOPR.
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    \5\ DOE received comments marked as confidential business 
information from Anthony International (see EERE-2017-BT-STD-0009-
0040) and Lennox International (see EERE-2017-BT-STD-0009-0036).
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II. Discussion

    This section summarizes the comments received from the CA IOUs and 
provides DOE's responses that were not addressed in the September 2023 
NOPR. Separate subsections address each component of DOE's analyses on 
which DOE has received comment from the CA IOUs.

A. General

    The CA IOUs recommended that DOE consider linear AWEF energy 
conservation standards for refrigeration systems that vary with 
capacity. (CA IOUs, No. 43 at p. 3) The CA IOUs stated that 
refrigeration efficiency typically increases with system capacity and 
pointed to the energy conservation standards for Commercial 
Refrigeration Equipment and Automatic Commercial Ice Makers, which are 
dependent on capacity. (Id.) The CA IOUs further provided examples 
supporting its assertion that efficiency increases with capacity for 
both dedicated condensing units and unit coolers. Specifically, the CA 
IOUs showed examples of standard options offered for model lines of 
medium- and low-temperature unit coolers; these examples show a larger 
capacity model line that is available with several options that are not 
available as standard features for the smaller capacity model line, 
including electronic expansion valves (``EEVs''), evaporator fan 
control boards, variable-speed electronically commutated fan motors 
(``ECMs''), and electronic controller systems that offer on-cycle 
evaporator fan controls and adaptive defrost capability. (Id. at pp. 3-
4) The CA IOUs also included in its comment examples of dedicated 
condensing system model lines that showed higher cooling efficiencies 
(in terms of energy efficiency ratio (``EER'')) for larger capacity 
systems. (Id. at p. 4) The CA IOUs also pointed to the baseline AWEFs 
presented in the preliminary analysis TSD, which increased with 
capacity. (Id. at pp. 5-7)
    In its analysis for the September 2023 NOPR, DOE evaluated the 
economics of each efficiency level for each representative unit, which 
indicated that more stringent standards were generally economically 
justified for larger units. Therefore, DOE proposed standards that 
varied with capacity for many refrigeration system equipment classes in 
the September 2023 NOPR. 88 FR 60746, 60748-60749. The proposed 
standards are summarized in section I of the September 2023 NOPR.

B. Market and Technology Assessment

    As discussed in the September 2023 NOPR, DOE develops information 
in the market and technology assessment that provides an overall 
picture of the market for the equipment concerned, including the 
purpose of the equipment, the industry structure, manufacturers, market 
characteristics, and technologies used in the equipment. 88 FR 60746, 
60760. This activity includes both quantitative and qualitative 
assessments, based primarily on publicly available information. The 
subjects addressed in the market and technology assessment for this 
rulemaking include (1) a determination of the scope of the rulemaking 
and equipment classes, (2) manufacturers and industry structure, (3) 
existing efficiency programs, (4) shipments information, (5) market and 
industry trends; and (6) technologies or design options that could 
improve the energy efficiency of walk-ins.
    As discussed in the September 2023 NOPR, DOE considered separate 
technology options for whole walk-ins, doors, and panels, and 
refrigeration systems. 88 FR 60746, 60764-60765. In the preliminary 
market analysis and technology assessment, DOE identified 16 technology 
options that would be expected to improve the efficiency of 
refrigeration systems. DOE requested comment on the technology options 
in section ES.4.2 of the June 2022 Preliminary Analysis TSD. In 
response, the CA IOUs suggested several modifications to the technology 
options analyzed by DOE in the June 2022 Preliminary Analysis. (CA 
IOUs, No. 43 at p. 8)
    In section 5.7.2.1 of chapter 5 of the June 2022 Preliminary 
Analysis TSD, DOE stated that at the time, it lacked data on the 
performance of multiple-capacity and variable-capacity compressors, but 
DOE intended to collect more data to evaluate these compressors as 
design options for the NOPR analysis. In response to the June 2022 
Preliminary Analysis, the CA IOUs commented that they support the 
evaluation of variable-capacity compressors as a design option. (CA 
IOUs, No. 43 at p. 8) The CA IOUs recommended that DOE request full EER 
curves of amperage versus capacity for variable-capacity compressors 
from manufacturers. (Id.) The CA IOUs also recommended that DOE perform 
testing to record the efficiency gains of variable-capacity compressors 
and evaluate the reduction in compressor cycling and improved ability 
of the

[[Page 66713]]

compressor to match the system cooling loads. (Id. at pp. 8-9)
    As discussed in the September 2023 NOPR, DOE analyzed variable-
capacity compressors for low- and medium-temperature refrigeration 
systems and assumed that the system was redesigned to take advantage of 
the variable-capacity compressor. 88 FR 60746, 60776. However, DOE was 
unable to obtain performance data from manufacturers as recommended by 
the CA IOUs, and therefore based the variable-capacity design option 
performance on its test data. Additional details of the variable-
capacity compressor design option implementation in the NOPR analysis 
can be found in chapter 5 of the accompanying TSD.\6\
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    \6\ The NOPR TSD can be found in the docket at regulations.gov/document/EERE-2017-BT-STD-0009-0046.
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    In the June 2022 Preliminary Analysis, DOE analyzed floating head 
pressure and floating head pressure with an EEV as design options for 
outdoor dedicated condensing units. See section 5.7.2.7 of the June 
2022 Preliminary Analysis TSD. In response to the June 2022 Preliminary 
Analysis, the CA IOUs suggested that DOE analyze EEVs as a technology 
option separate from floating head pressure. (Ca IOUs, No. 43 at p. 10) 
The CA IOUs provided an example where the use of an EEV rather than a 
thermostatic expansion valve (``TXV'') saved energy by reducing cycling 
losses where the TXV ``hunts'' for the optimal opening range. (Id.) 
Further, the CA IOUs commented that EEVs allow for more precise 
superheat control over TXVs, which could improve energy efficiency. 
(Id. at p. 10)
    DOE notes that the tests conducted as part of the test procedures 
in appendix C1 are steady-state tests. Because of this, DOE has 
tentatively concluded that a test performed with a TXV would result in 
the same measured efficiency as a test of the same unit performed with 
an EEV. DOE acknowledges that a unit cooler installed with an EEV may 
be able to achieve more capacity for a given suction condition given 
that EEVs can achieve less superheat than a TXV would be able to. 
Considering feedback received during manufacturer interviews, DOE has 
tentatively concluded that manufacturers would not recommend a lower 
superheat value for unit coolers installed with an EEV rather than a 
TXV. Additionally, DOE notes that Figure 8 presented in the CA IOUs 
comment shows that at the steady-state operation that is the basis of 
test procedures, systems equipped with TXVs are no less efficient than 
systems equipped with EEVs. As such DOE has tentatively concluded that 
when performing a valid refrigeration system test according to the DOE 
test procedure, replacing a TXV with an EEV would not improve measured 
efficiency. For this reason, DOE did not analyze EEVs as a standalone 
technology in the September 2023 NOPR analysis. See section 5.7.2.7 of 
the September 2023 NOPR TSD for discussion of how DOE considered head 
pressure control in the analysis.
    See chapter 3 of the September 2023 NOPR TSD for further discussion 
of the market and technology assessment.

C. Engineering Analysis

    As discussed in the September 2023 NOPR, the purpose of the 
engineering analysis is to establish the relationship between the 
efficiency and cost of each component of walk-ins (e.g., doors, panels, 
and refrigeration systems). 88 FR 60746, 60767. There are two elements 
to consider in the engineering analysis; the selection of efficiency 
levels to analyze (i.e., the ``efficiency analysis'') and the 
determination of product cost at each efficiency level (i.e., the 
``cost analysis''). In determining the performance of higher-efficiency 
walk-ins, DOE considers technologies and design option combinations not 
eliminated by the screening analysis. For each walk-in component 
equipment class, DOE estimates the baseline cost, as well as the 
incremental cost for the walk-in component at efficiency levels above 
the baseline. The output of the engineering analysis is a set of cost-
efficiency ``curves'' that are used in downstream analyses (i.e., the 
LCC and PBP analyses and the NIA).
    In section ES4.4 of the June 2022 Preliminary Analysis TSD, DOE 
requested comment on the efficiency levels considered in the analysis. 
Specifically, DOE sought feedback on whether the efficiency levels 
beyond the baseline are appropriate, including the maximum technology 
efficiency level.
a. Display Doors
    The CA IOUs commented that, based on its evaluation, the ratings in 
DOE's Compliance Certification Management System Database (``CCD'') for 
display doors are conservative. The CA IOUs asserted that the ratings 
in CCD for display doors should not be used as the basis for 
establishing an updated energy conservation standard because their 
analysis suggests the ratings are conservative. Rather, the CA IOUs 
encouraged DOE to independently evaluate the performance of 
representative display doors in its analysis. (CA IOUs, No. 43 at pp. 
7-8, 21)
    In response, DOE notes that it did not analyze higher efficiency 
levels for display doors solely using data from CCD, but rather 
conducted testing on doors with varying glass pack designs. See 
sections 5.6.1 and 5.7.1.1 of the NOPR TSD for further discussion on 
DOE's methodology for developing the baseline and higher efficiency 
energy consumption characteristics for the representative units of 
display doors analyzed.
b. Refrigeration Systems
    The CA IOUs stated that the AWEF levels in CCD are based on the 
base model of a product line rather than the models that utilize higher 
efficiency design options. (CA IOUs, No. 43 at p. 3) The CA IOUs also 
commented that DOE's performance modeling in the June 2022 Preliminary 
Analysis underestimated the efficiency benefits of the design options 
currently available in the market. (Id.) The CA IOUs recommended that 
DOE validate the results of the June 2022 Preliminary Analysis by 
conducting testing on representative examples of walk-in refrigeration 
systems. (Id.)
    As discussed in the September 2023 NOPR, DOE used a design-option 
approach for dedicated condensing units and single-packaged dedicated 
systems. 88 FR 60746, 60768. DOE's performance modeling of each design 
option for dedicated condensing units and single-packaged dedicated 
systems in the September 2023 NOPR analysis was developed with 
manufacturer feedback through confidential manufacturer interviews. 
Additionally, DOE notes that is has validated its results of the 
September 2023 NOPR analysis through its own walk-in refrigeration 
system testing. See section 5.7.2 of the September 2023 NOPR TSD for 
details of the refrigeration systems engineering analysis.
    Furthermore, DOE used both an efficiency-level approach and design 
option approach for its analysis of unit coolers, depending on 
equipment class. 88 FR 60746, 60768. DOE's performance modeling of 
medium- and low-temperature unit coolers in the September 2023 NOPR 
analysis was based on the capacities certified in the CCD, fan power 
data from product literature, and the default defrost energy use from 
AHRI 1250-2020 \7\ adjusted

[[Page 66714]]

such that the lowest calculated AWEFs match the current energy 
conservation standard. DOE notes that while most of the unit coolers in 
the CCD are rated at baseline, when AWEF is calculated using the data 
as described, many units appear to have efficiencies above baseline. 
DOE has tentatively determined that the results of these analyses are 
representative of the units and technologies currently available on the 
market. Details of the unit cooler engineering analysis are discussed 
in section 5.8 of the September 2023 NOPR TSD.
---------------------------------------------------------------------------

    \7\ Appendix C1 references industry test standard Air-
Conditioning, Heating, and Refrigeration Institute (``AHRI'') 
Standard 1250-2020, 2020 Standard for Performance Rating of Walk-in 
Coolers and Freezers (``AHRI 1250-2020'').
---------------------------------------------------------------------------

Refrigerants Analyzed
    The CA IOUs commented that it expects that the use of R-404A to 
estimate the performance of CO<INF>2</INF>-based unit coolers (which 
DOE did in the June 2022 Preliminary Analysis) would result in a 
similar AWEF to that of an AWEF that was based on performance data of 
CO<INF>2</INF>. However, the CA IOUs recommended that DOE use 
CO<INF>2</INF> data in its analysis to avoid confusion. The CA IOUs 
stated that DOE should use available CO<INF>2</INF>-specific data, 
request information from manufacturers, and derive EER curves using 
software tools. (CA IOUs, No. 43 at p. 14)
    DOE acknowledges that there is some performance data available for 
CO<INF>2</INF> unit-coolers. However, the CCD and manufacturer product 
literature have more data available for unit coolers that use R-404A. 
In response to the preliminary analysis, as discussed in the September 
2023 NOPR, HTPG supported the use of R-404A to analyze medium- and low-
temperature unit coolers. 88 FR 60746, 60779. Additionally, as the CA 
IOUs stated, the performance results of unit coolers using R-404A and 
CO<INF>2</INF> are similar. DOE has tentatively concluded that using R-
404A as the refrigerant for the analysis of medium- and low-temperature 
unit coolers is representative of the unit cooler market. Therefore, as 
discussed in the September 2023 NOPR, DOE used R-404A as the 
refrigerant in its analysis of medium- and low-temperature unit 
coolers. 88 FR 60746, 60780. Further, DOE notes that the EERs used to 
calculate unit cooler AWEF and AWEF2 are prescribed by the suction 
conditions and EER table of the DOE test procedure at section 3.4.14 of 
appendix C1. As such, DOE did not consider alternative EER curves in 
the September 2023 NOPR analysis.
Representative Units
    In section 2.2 of the June 2022 Preliminary Analysis TSD, DOE 
stated that it has not seen condensate heaters on any of the single-
packaged dedicated systems that it has tested. When making this 
statement in the June 2022 Preliminary Analysis, DOE was referring to 
pan heaters. In response, the CA IOUs commented that they are aware of 
three manufacturers of packaged systems that currently offer a 
condensate heater element and showed examples of unit coolers that 
offer drain line heaters as standard features or options. (CA IOUs, No. 
43 at pp. 12-14) Additionally, the CA IOUs stated that in specific 
applications (e.g., meat and dairy coolers) medium-temperature coolers 
typically use condensate heaters. (Id. at p. 12) Therefore, the CA IOUs 
recommended that AWEF should include an allocation for condensate 
heater energy use. (Id.)
    DOE has not encountered drain line heaters on any of the single-
packaged dedicated systems or unit coolers that it has tested and DOE 
expects that drain line heaters would typically be provided as an 
optional feature and installed by a contractor. In the September 2023 
NOPR analysis, DOE evaluated what it considers to be ``representative 
units'' in the market; therefore, DOE did not evaluate units with drain 
line heaters.
    DOE has encountered low-temperature unit coolers with pan heaters. 
In the September 2023 NOPR analysis, DOE based the low-temperature unit 
cooler defrost power on the default defrost power calculations in AHRI 
1250-2020. See section C10.2 of AHRI 1250-2020 for details. These 
calculated power values are representative of the power draw of the 
entire unit cooler during a defrost cycle. Additionally, the default 
defrost power calculations in AHRI 1250-2020 include a set of 
calculations for units with hot gas coil defrost and an electric 
resistive pan heater. See section C10.1.2 of AHRI 1250-2020. As such, 
DOE has tentatively determined that the AHRI 1250-2020 default power 
calculations include representative pan heater power consumption and 
that an allocation for condensate heater energy use is not warranted at 
this time.
Baseline Efficiency
    For each equipment class, DOE generally selects a baseline model as 
a reference point for each class, and measures changes resulting from 
potential energy conservation standards against the baseline. The 
baseline model in each equipment class represents the characteristics 
of equipment typical of that class (e.g., capacity, physical size). 
Generally, a baseline model is one that just meets current energy 
conservation standards, or, if no standards are in place, the baseline 
is typically the most common or least efficient unit on the market.
    The CA IOUs stated that when DOE updates a test procedure for 
equipment already included in the DOE regulatory program, DOE typically 
performs a cross-walk analysis to ensure energy conservation standards 
set using the new test procedure do not result in backsliding. (CA 
IOUs, No. 43 at p. 1) The CA IOUs commented that the June 2022 
Preliminary Analysis TSD does not appear to include a cross-walk 
analysis (Id.) The CA IOUs stated that, therefore, its comments 
regarding the baseline efficiency assumed the analysis presented in the 
preliminary TSD was based on the current test procedure at appendix C 
to subpart R of 10 CFR part 431. (Id. at pp. 2-3) Based on this 
assumption, the CA IOUs encouraged DOE to align the baseline efficiency 
level of all refrigeration systems with the current minimum energy 
conservation standards and indicated which representative units they 
interpreted as having efficiency levels below the current minimum 
energy conservation standards. Id.
    Current energy conservation standards for walk-in refrigeration 
systems are in terms of the AWEF metric and the energy conservation 
standards proposed in the September 2023 NOPR use the AWEF2 metric. The 
primary difference between these two metrics is that AWEF2 includes 
off-cycle power consumption.\8\ As discussed in the September 2023 
NOPR, DOE set baseline efficiency levels for dedicated condensing units 
with energy conservation standards at the current minimum standard 
level using the appendix C test procedure (see appendix C to subpart R 
to 10 CFR 431). 88 FR 60746, 60778. For example, for a medium-
temperature, outdoor dedicated condensing unit, DOE determined which 
technology options would just meet the current AWEF standard of 7.6 
Btu/(W-h) using the appendix C test procedure. Id. Once each 
representative unit had its baseline design options set, DOE conducted 
the remainder of the efficiency analysis using the appendix C1 test 
procedure to determine AWEF2 values for each efficiency level, 
including the baseline. Id. DOE notes that in the June 2022 Preliminary 
Analysis, refrigeration system efficiency values were labeled as AWEF; 
however, all efficiency values calculated in accordance with the 
appendix C1 test

[[Page 66715]]

procedure were AWEF2 values, as defined in appendix C1. Id.
---------------------------------------------------------------------------

    \8\ The complete discussion of the differences between these 
metrics can be found in the May 2023 Test Procedure Final Rule. 88 
FR 28780, 28810.
---------------------------------------------------------------------------

    The representative units that DOE modeled in the September 2023 
NOPR analysis were based on actual units that are certified at the 
currently applicable minimum energy conservation standards (i.e., 
baseline AWEF) in CCD. To account for the differences between AWEF and 
AWEF2, DOE determined representative off-cycle power values for each 
representative unit analyzed in the September 2023 NOPR using product 
catalogs and feedback from manufacturer interviews.
    Additionally, in the September 2023 NOPR, DOE proposed more 
stringent energy conservation standards for the majority of 
refrigeration system equipment classes. 88 FR 60746, 60748-60749. The 
only equipment classes with standards proposed at the equivalent 
current baseline in terms of the new AWEF2 metric are medium-
temperature indoor dedicated condensing systems with a capacity of less 
than 8,000 Btu/h and low-temperature indoor dedicated condensing 
systems with a capacity of 9,000 Btu/h. See section IV.C.1.d of the 
September 2023 NOPR for further discussion of the analysis based on 
AWEF2.
Design Options
    In chapter 5 of the June 2022 Preliminary Analysis TSD, DOE 
analyzed improved condenser coils as a design option for dedicated 
condensing system equipment classes. See section 5.7.2.2 of the 
Preliminary Analysis TSD for details of this analysis. Based on 
information gathered during previous rulemakings and feedback received 
during the preliminary analysis manufacturer interviews, DOE determined 
representative improved midpoint condensing temperatures for the 
representative units analyzed. DOE published the following table to 
summarize the baseline and improved condensing midpoint temperatures.

       Table II.1--Walk-In Refrigeration System Condenser Coil Temperature Difference (``TD'') Assumptions
----------------------------------------------------------------------------------------------------------------
                                 Temperature of
                                air entering the     Baseline       Baseline TD      Improved       Improved TD
        Equipment class          condenser coil      midpoint        ([deg]F)        midpoint        ([deg]F)
                                    ([deg]F)         ([deg]F)                        ([deg]F)
----------------------------------------------------------------------------------------------------------------
SPU.H.I.......................                90             115              20             110              15
DC/SPU.M.I....................                90             115              25             110              20
DC/SPU.L.I....................                90             110              20             105              15
SPU.H.O.......................                95             120              20             115              15
DC/SPU.M.O....................                95             120              25             115              20
DC/SPU.L.O....................                95             115              20             110              15
----------------------------------------------------------------------------------------------------------------

    In response to the June 2022 Preliminary Analysis, the CA IOUs 
recommended that DOE should review the baseline and improved condensing 
midpoint assumptions used for high-temperature single-packaged 
dedicated systems, as the temperature differences and ambient air 
temperatures do not sum to equal the corresponding midpoint 
temperature. (CA IOUs, No. 43 at p. 16)
    DOE acknowledges that the baseline and improved temperature 
differences for high-temperature single-packaged dedicated condensing 
systems were incorrectly printed in table 5.7.13 in the June 2022 
Preliminary Analysis TSD. For high-temperature single-packaged 
dedicated condensing systems, the table should have listed the baseline 
temperature difference as 25 [deg]F and the improved temperature 
difference as 20 [deg]F. These misprints only occurred in this table 
and the correct values were used in conducting the June 2022 
Preliminary Analysis. Similarly, as discussed in section 5.7.2.2 of the 
September 2023 NOPR TSD, DOE did not use the incorrect values in the 
September 2023 NOPR analysis.
    In the June 2022 Preliminary Analysis, DOE analyzed head pressure 
controls as a design option for outdoor dedicated condensing system 
equipment classes. See section 5.7.2.7 of the June 2022 Preliminary 
Analysis TSD for details. Head pressure controls allow outdoor 
condensing units' head pressure to ``float'' down to a minimum 
condensing pressure as the ambient air temperature falls. This allows 
the compressor to operate more efficiently and therefore reduces the 
power consumption of the system without reducing the capacity. As 
discussed in section 5.7.2.7 of the June 2022 Preliminary Analysis TSD, 
DOE evaluated two design options pertaining to head pressure control 
for the representative units of outdoor dedicated condensing units and 
outdoor single-packaged dedicated systems analyzed. These two design 
options were floating head pressure and floating head pressure with an 
EEV.\9\ DOE assumed fixed head pressure would be the baseline design. 
Based on information collected during previous rulemakings, DOE 
determined the minimum condensing pressure associated with these design 
options. DOE converted all minimum condensing pressures to minimum 
condenser dewpoint temperatures so that the values would be refrigerant 
agnostic. DOE assumed this minimum dewpoint would apply at the lowest 
ambient rating condition--35 [deg]F. At the intermediate rating 
temperature of 59 [deg]F, DOE estimated the head pressure for fixed and 
floating systems when using a TXV based on testing results. DOE did not 
have testing results for a system with an EEV, so DOE calculated the 
degree to which the pressure would ``float'' down based on an 
assumption that the condenser TD would scale with the capacity. DOE 
used test results and scaling to estimate a minimum dewpoint offset at 
59 [deg]F. Minimum condensing dewpoints at the 35 [deg]F C test point 
and at the 59 [deg]F B test point are summarized in Table II.2.
---------------------------------------------------------------------------

    \9\ Systems equipped with an EEV could operate with an even 
lower head pressure because the greater flexibility of the 
electronic controls allows an EEV to have a wider range of orifice 
open area without leading to unstable operation in warm ambient 
conditions.

[[Page 66716]]



Table II.2--Summary of Preliminary Analysis Head Pressure Control Design
                                 Options
------------------------------------------------------------------------
                               Minimum condensing    Minimum condensing
  Design option description      dewpoint at 35        dewpoint at 59
                                 [deg]F ([deg]F)       [deg]F ([deg]F)
------------------------------------------------------------------------
Fixed head pressure.........                 101.5                 104.4
Floating head pressure......                    85                  86.7
Floating head pressure with                     67                  85.9
 an electronic expansion
 valve......................
------------------------------------------------------------------------

    In addition to the minimum condensing dewpoints imposed by head 
pressure control strategies, different compressor types have different 
minimum condensing dewpoints. The minimum condensing dewpoint 
temperatures for hermetic, semi-hermetic, scroll and rotary compressors 
used in the June 2022 Preliminary Analysis are listed in Table II.3.

 Table II.3--Minimum Condensing Dewpoint Temperatures by Compressor Type
               Used in the June 2022 Preliminary Analysis
------------------------------------------------------------------------
                                                    Minimum condensing
                Compressor type                    dewpoint temperature
                                                         ([deg]F)
------------------------------------------------------------------------
Hermetic.......................................                       85
Semi-hermetic..................................                       67
Scroll.........................................                       67
Rotary.........................................                       67
------------------------------------------------------------------------

    In response to the June 2022 Preliminary Analysis, the CA IOUs 
stated that its interpretation of the June 2022 Preliminary Analysis 
assumed that the minimum condensing pressure is reached only at the 35 
[deg]F ambient C test condition. (CA IOUs, No. 43 at p. 14) The CA IOUs 
commented that in its experience, the minimum condensing pressure is 
reached anytime the ambient temperature plus the condenser temperature 
difference is less than the minimum condensing temperature and that the 
minimum condensing pressure is ``fixed'' (i.e., does not change with 
lower ambient temperatures) and that controls and valves function to 
maintain that pressure. (Id. at pp. 14-15).
    Based on test data and feedback during manufacturer interviews, DOE 
tentatively concluded that the minimum condensing dewpoint temperature 
can be reached at ambient temperatures above 35 [deg]F. DOE determined 
the condensing dewpoints at the B (59 [deg]F) and C (35 [deg]F) test 
points considering the minimum condensing dewpoint allowed by the 
floating head pressure controls and compressor type of the 
representative unit as well as the minimum condensing temperature 
necessary to achieve a sufficient condenser temperature difference. The 
details of this analysis can be found in section 5.7.2.7 of the 
September 2023 NOPR TSD.
    Additionally, the CA IOUs stated that generally, fixed head 
pressure systems have minimum condensing dewpoint temperatures of 95 
[deg]F to 120 [deg]F and that adding floating head pressure controls 
with TXVs to these systems allows minimum condensing dewpoint 
temperatures of 70 [deg]F to 85 [deg]F and changing the TXVs for EEVs 
on systems with floating head pressure controls allows temperatures of 
55 [deg]F to 70 [deg]F. (CA IOUs, No. 43 at p. 14) The CA IOUs stated 
that minimum condensing dewpoint temperature for low-temperature 
systems can be lower than those for medium-temperature systems. Id. DOE 
determined the minimum condensing dewpoint temperature for the 
September 2023 NOPR analysis using feedback from confidential 
manufacturer interviews. DOE aggregated this feedback and tentatively 
determined that 72 [deg]F is a representative minimum condensing 
dewpoint for the walk-in industry as a whole. During interviews, 
manufacturers indicated that this was a standard design on all walk-in 
condensing systems and that this minimum condensing dewpoint 
temperature could be achieved by systems using TXVs, therefore DOE did 
not consider an additional step down in pressure associated with EEVs. 
Based on testing results, DOE tentatively determined that most 
dedicated condensing systems would need this floating head pressure 
design option to achieve the current AWEF standards. Feedback from the 
most recent round of manufacturer interviews confirmed this. As such 
DOE considered floating head pressure controls as the baseline design 
option for all dedicated condensing system representative units in the 
September 2023 NOPR analysis and did not consider floating head 
pressure controls with an EEV as a design option. See section 5.7.2.7 
of the September 2023 NOPR TSD for details of this analysis.
    Additionally, the CA IOUs stated that the minimum condensing 
dewpoints allowed by the compressor operating envelopes in DOE's June 
2022 Preliminary Analysis are too high and provided examples of semi-
hermetic compressors with lower minimum condensing dewpoints. (CA IOUs, 
No. 43 at p. 15)
    Information obtained during previous rulemakings and manufacturer 
feedback received during the most recent interviews indicated that the 
operating envelope of hermetic reciprocating compressors would limit 
the minimum condensing dewpoint further. As such, DOE set the minimum 
condensing dewpoint for hermetic compressors at 85 [deg]F. DOE 
acknowledges that the published operating envelope of semi-hermetic, 
scroll, and rotary compressors may allow for condensing dewpoints lower 
than 72 [deg]F. However, manufacturers indicated that in spite of the 
lower dewpoints published in compressor literature, they and their 
customers have concerns about the potential system reliability issues. 
The 72 [deg]F is representative of the lowest dew point levels used for 
rating purposes by manufacturers. In many cases this level can be 
adjusted in the field, and it often is set higher. As such, DOE did not 
consider condensing dewpoints lower than 72 [deg]F in the September 
2023 NOPR analysis. The floating head pressure design option is 
discussed in more

[[Page 66717]]

detail in section 5.7.2.7 of chapter 5 of the September 2023 NOPR TSD.
    The CA IOUs recommended that DOE use the minimum condensing 
midpoint instead of the minimum condensing dewpoint in its analysis 
when discussing floating head pressure control. (CA IOUs, No. 43 at p. 
15) As discussed in section 5.5.3.1 of the September 2023 NOPR TSD, DOE 
used the compressor model described in section 6.4 of AHRI Standard 
540-2004, ``Performance Rating of Positive Displacement Refrigerant 
Compressors and Compressor Units'' to determine compressor power 
consumption and mass flow at each test condition. This model requires 
condensing dewpoint, rather than mid-point, as an input. Therefore, DOE 
used condensing dewpoint to characterize the floating head pressure 
design option.
    In the June 2022 Preliminary Analysis, DOE did not analyze on-cycle 
evaporator fan control as a design option because DOE had tentatively 
determined that variable-capacity compressors are a prerequisite for 
on-cycle evaporator fan controls to be effective. DOE did not analyze 
variable-capacity compressors as a design option in the June 2022 
Preliminary Analysis because it had insufficient data at the time to 
analyze them. See section 5.7.2.13 of the June 2022 Preliminary 
Analysis TSD.
    In response, the CA IOUs agreed that on-cycle evaporator fan 
controls are most effective when paired with variable-capacity 
compressors, but referenced methods of fan control that could provide 
efficiency benefits without a multiple- or variable-capacity 
compressor. Therefore, the CA IOUs suggested that evaporator fan on-
cycle control should be evaluated as a design option for single-
packaged dedicated systems without a multiple- or variable-capacity 
compressor. (CA IOUs, No. 43 at p. 9) The CA IOUs provided two examples 
of how evaporator fan control could result in energy savings: (1) 
setting fan speed using refrigerant liquid temperature change across 
the expansion valve; and (2) setting fan speed based on walk-in 
interior temperature and refrigerant coil temperature using an 
electronic expansion valve (``EEV'') to control superheat. Id. Further, 
the CA IOUs commented that evaporator fans included in a walk-in system 
are based on ambient design conditions, which may only occur a few days 
per year and provided an example of a unit cooler that has evaporator 
fans running below full load for a majority of the time. (Id. at pp. 9-
10)
    DOE interprets the first fan control method described in the CA 
IOUs comment to be a reduction in fan power when the liquid line 
solenoid closes, indicating the compressor is cycling off. DOE 
considered off-cycle fan control for single-packaged dedicated systems 
in the September 2023 NOPR analysis, discussed in detail in section 
5.7.2.8 of the September 2023 NOPR TSD. Based on the description of the 
second fan control method described in the CA IOUs comment, DOE has 
tentatively determined that when operating in a test chamber held at a 
constant temperature (consistent with the test procedure approach of 
testing with constant evaporator inlet air condition or constant 
condensing unit suction inlet condition) such a control system would 
not trigger any reduction in fan speed. Therefore, when tested 
according to the DOE test procedure in appendix C1 to 10 CFR part 431 
subpart R (``appendix C1'') a single-packaged dedicated system equipped 
with this evaporator fan control system would not have an improved 
efficiency. In addition, DOE notes that the figure provided as an 
example in the CA IOUs' comment shows condenser fan run time, not 
evaporator fan run time. DOE did consider on-cycle condenser fan 
controls in the September 2023 NOPR analysis. 88 FR 60746, 60767.
    In the June 2022 Preliminary Analysis DOE analyzed permanent-split 
capacitor (``PSC'') and ECM motors as design options for improved 
condenser fan motors, and did not analyze improved evaporator fan 
motors as a design option. See sections 5.7.2.4 and 5.7.2.11 of the 
June 2022 Preliminary Analysis TSD. In response, the CA IOUs commented 
that DOE should consider permanent magnet AC (``PMS'') motors as the 
maximum-technologically-feasible design option for unit cooler fan 
motors and as a technology option for condensing unit fan motors. The 
CA IOUs cited examples of how PMS motor efficiency compares with ECM 
efficiency, specifically stating that PMS motors can offer an average 
of 17-27 percent energy savings over ECMs for unit cooler fan motors 
and 40 percent savings over permanent-split capacitor (``PSC'') motors 
that are mostly installed in condensing units. The CA IOUs stated that 
several utility and efficiency organizations offer rebate programs to 
upgrade ECMs with PMS motors. However, the CA IOUs stated that PMS 
motors are not available in new equipment and that it was only aware of 
one manufacturer offering PMS motors. (CA IOUs, No. 43 at pp. 11-12)
    EPCA governs permissible evaporator and condenser fan motors in 
walk-ins (42 U.S.C. 6313(f)(1)(E) and (F)). For condenser fan motors 
under 1 horsepower (``HP''), EPCA prescribes the use of either ECMs, 
permanent split capacitor (``PSC'') type motors, or 3-phase motors. (42 
U.S.C. 6313(f)(1)(F)) DOE only analyzed one representative unit with 
condenser fan motors equal to or greater than 1 HP in the September 
2023 NOPR analysis, which did not include a permanent magnet AC motor. 
Given that EPCA does not allow the use of any other motor types for 
motors under 1 horsepower, DOE did not consider permanent magnet AC 
motors as a design option for condenser fan motors.
    For evaporator fan motors under 1 HP, EPCA prescribes the use of 
either ECMs or 3-phase motors. (42 U.S.C. 6313(f)(1)(E)) DOE has 
adopted this requirement in its regulations at 10 CFR 431.306(a)(5)(i)-
(ii). DOE has encountered commercially available motor technologies 
that may perform more efficiently than the ECMs already required by the 
prescriptive standard. However, consistent with the EPCA requirements 
and existing regulations, DOE did not include them in its September 
2023 NOPR analysis. See section 5.7.2.11 of the September 2023 NOPR 
TSD. Additionally, DOE notes that all evaporator fan powers are under 
the 1 HP threshold for the representative units analyzed at the 
proposed standard levels in the September 2023 NOPR.

D. Life-Cycle Cost and Payback Period Analysis

    As discussed in the September 2023 NOPR, DOE conducted LCC and PBP 
analyses to evaluate the economic impacts on individual consumers of 
potential energy conservation standards for walk-ins. The effect of new 
or amended energy conservation standards on individual consumers 
usually involves a reduction in operating cost and an increase in 
purchase cost. DOE used the following two metrics to measure consumer 
impacts:
    <bullet> The LCC is the total consumer expense of an appliance or 
product over the life of that product, consisting of total installed 
cost (manufacturer selling price, distribution chain markups, sales 
tax, and installation costs) plus operating costs (expenses for energy 
use, maintenance, and repair). To compute the operating costs, DOE 
discounts future operating costs to the time of purchase and sums them 
over the lifetime of the product.
    <bullet> The PBP is the estimated amount of time (in years) it 
takes consumers to recover the increased purchase cost (including 
installation) of a more-efficient product through lower

[[Page 66718]]

operating costs. DOE calculates the PBP by dividing the change in 
purchase cost at higher efficiency levels by the change in annual 
operating cost for the year that amended or new standards are assumed 
to take effect.
    For any given efficiency level, DOE measures the change in LCC 
relative to the LCC in the no-new-standards case, which reflects the 
estimated efficiency distribution of walk-ins in the absence of new or 
amended energy conservation standards. In contrast, the PBP for a given 
efficiency level is measured relative to the baseline product.
    For each considered efficiency level in each equipment class, DOE 
calculated the LCC and PBP for a nationally representative set of 
commercial consumers. As stated previously, DOE developed household 
samples from the 2018 Commercial Buildings Energy Consumption Survey 
(``CBECS'').\10\ For each sample, DOE determined the energy consumption 
for the walk-ins and the appropriate energy price. By developing a 
representative sample of commercial consumers, the analysis captured 
the variability in energy consumption and energy prices associated with 
the use of walk-ins.
---------------------------------------------------------------------------

    \10\ U.S. Energy Information Administration. Commercial 
Buildings Energy Consumption Survey 2018, 2022.
---------------------------------------------------------------------------

    Inputs to the calculation of total installed cost include the cost 
of the product--which includes MPCs, manufacturer markups, retailer and 
distributor markups, and sales taxes--and installation costs. Inputs to 
the calculation of operating expenses include annual energy 
consumption, energy prices and price projections, repair and 
maintenance costs, product lifetimes, and discount rates. DOE created 
distributions of values for product lifetime, discount rates, and sales 
taxes, with probabilities attached to each value, to account for their 
uncertainty and variability.
    The computer model DOE uses to calculate the LCC relies on a Monte 
Carlo simulation to incorporate uncertainty and variability into the 
analysis. The Monte Carlo simulations randomly sample input values from 
the probability distributions and walk-ins user samples. The model 
calculated the LCC for products at each efficiency level per simulation 
run. The analytical results include a distribution of 30,000 data 
points for refrigeration systems and 10,000 data points for envelope 
components, showing the range of LCC savings for a given efficiency 
level relative to the no-new-standards case efficiency distribution. In 
performing an iteration of the Monte Carlo simulation for a given 
consumer, product efficiency is chosen based on its probability. If the 
chosen product efficiency is greater than or equal to the efficiency of 
the standard level under consideration, the LCC calculation reveals 
that a consumer is not impacted by the standard level. By accounting 
for consumers who already purchase more-efficient products, DOE avoids 
overstating the potential benefits from increasing product efficiency.
    DOE calculated the LCC and PBP for consumers of walk-ins as if each 
were to purchase a new product in the expected year of required 
compliance with new or amended standards. Amended standards would apply 
to walk-ins manufactured three years after the date on which any new or 
amended standard is published. (42 U.S.C. 6313(f)(5)(B)(i)) At this 
time, DOE estimates publication of a final rule in 2024; therefore, for 
purposes of its analysis, DOE used 2027 as the first year of compliance 
with any amended standards for walk-ins.
    Table II.4 summarizes the approach and data DOE used to derive 
inputs to the LCC and PBP calculations. The subsections that follow 
provide further discussion. Details of the spreadsheet model, and of 
all the inputs to the LCC and PBP analyses, are contained in chapter 8 
of the September 2023 NOPR TSD and its appendices.

  Table II.4--Summary of Inputs and Methods for the September 2023 NOPR
                         LCC and PBP Analysis *
------------------------------------------------------------------------
            Inputs                           Source/method
------------------------------------------------------------------------
Product Cost.................  Derived by multiplying MPCs by
                                manufacturer and retailer markups and
                                sales tax, as appropriate. Used
                                historical data to derive a price
                                scaling index to project product costs.
Installation Costs...........  Baseline installation cost determined
                                with data from RS Means. Assumed no
                                change with efficiency level.
Annual Energy Use............  The total annual energy use multiplied by
                                the buildings containing WICF.
                                Variability: Based on the CBECS 2018.
Energy Prices................  Electricity: Based on EIA's Form 861 data
                                for 2021. Variability: Regional energy
                                prices determined for 9 divisions.
Energy Price Trends..........  Based on AEO2023 price projections.
Repair and Maintenance Costs.  Assumed no change with efficiency level.
Product Lifetime.............  Average: between 9 and 12 years.
Discount Rates...............  Approach involves identifying all
                                possible debt or asset classes that
                                might be used to purchase the considered
                                appliances, or might be affected
                                indirectly. Primary data source was the
                                Federal Reserve Board's Survey of
                                Consumer Finances.
Compliance Date..............  2027.
------------------------------------------------------------------------
* Not used for PBP calculation. References for the data sources
  mentioned in this table are provided in the sections following the
  table or in chapter 8 of the September 2023 NOPR TSD.

1. Consumer Sample
    As discussed in the September 2023 NOPR DOE conducts its analysis 
in support of a potential new minimum efficiency standard at the 
National level. This means that DOE must distribute its sample of 
consumers of walk-in equipment throughout the Nation to capture 
variability of key inputs of walk-ins operation. Specifically, for the 
annual energy use estimate, DOE is concerned about distributing the 
population of walk-in installations across different regions to capture 
variability in equipment installation saturations and electricity 
prices, which will impact the operating cost of the equipment. This 
distribution of installations is referred to as the ``consumer 
sample.''
    The CA IOUs suggested that DOE revise the distribution of weights 
of WICF equipment by sector. (CA IOUs, No. 43 at pp. 18-19)
    As stated in the September 2023 NOPR, DOE used data supplied by

[[Page 66719]]

AHRI and CBECS to estimate the number of walk-in installations by 
sector and Census Division. 88 FR 60746, 60792. The weights of each 
representative unit by sector are repeated from the September 2023 NOPR 
here in Table II.5 through Table II.7.\11\ These weights show that 
dedicated condensing systems are evenly spread across all sectors, with 
small business sectors limited to smaller capacity equipment. 
Additionally, single-packaged dedicated condensing systems are limited 
to the small business sectors and concentrated in the food service 
sector.
---------------------------------------------------------------------------

    \11\ A full breakdown of the consumer sample showing the 
distribution of equipment by Census Division can be found in 
appendix 8E of the September 2023 NOPR TSD.

                                           Table II.5--Consumer Sample and Weights--Dedicated Condensing Units
                                                                           [%]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Sector                                                Capacity (kBtu/hr)
         Equipment class         -----------------------------------------------------------------------------------------------------------------------
                                           Cat.                    Size                3           9          25          54          75          124
--------------------------------------------------------------------------------------------------------------------------------------------------------
DC.L.I..........................  Other.................  Large.................          23          18           4          10  ..........  ..........
                                                          Small.................           1           1           0           0  ..........  ..........
                                  Sales.................  Large.................           4           3           1           2  ..........  ..........
                                                          Small.................           3           3           1           0  ..........  ..........
                                  Service...............  Large.................           5           4           1           2  ..........  ..........
                                                          Small.................           7           6           1           0  ..........  ..........
DC.L.O..........................  Other.................  Large.................           7          25           7           5          14  ..........
                                                          Small.................           0           2           0           0           0  ..........
                                  Sales.................  Large.................           1           4           1           1           2  ..........
                                                          Small.................           1           4           1           0           0  ..........
                                  Service...............  Large.................           1           6           1           1           3  ..........
                                                          Small.................           2           8           2           0           0  ..........
DC.M.I..........................  Other.................  Large.................        * 12          30           7           4           0  ..........
                                                          Small.................         * 1           2           0           0           0  ..........
                                  Sales.................  Large.................         * 2           5           1           1           0  ..........
                                                          Small.................         * 2           4           1           0           0  ..........
                                  Service...............  Large.................         * 3           6           1           1           0  ..........
                                                          Small.................         * 4           9           2           0           0  ..........
DC.M.O..........................  Other.................  Large.................         * 3          30           9           2           6           6
                                                          Small.................         * 0           2           1           0           0           0
                                  Sales.................  Large.................         * 1           5           2           0           1           1
                                                          Small.................         * 0           4           1           0           0           0
                                  Service...............  Large.................         * 1           7           2           0           1           1
                                                          Small.................         * 1           9           3           0           0           0
--------------------------------------------------------------------------------------------------------------------------------------------------------
* For the September 2023 NOPR DOE did not consider the impacts of representative units DC.M.I and DC.M.O at the 3 kBtu/hr capacity (see the
  Representative Units subsection of section IV.C.1.d of the September 2023 NOPR 88 FR 60746, 60780). However, these capacities persist within the
  consumer sample as they are still distributed in commerce, and the impacts for the fraction of these equipment must be accounted for when determining
  overall costs and benefits for DC.M.I and DC.M.O as equipment classes even if efficiency improvements are not being considered for these specific
  capacities.


                   Table II.6--Consumer Sample and Weights--Single-Packaged Dedicated Systems
                                                       [%]
----------------------------------------------------------------------------------------------------------------
                                             Sector                             Capacity (kBtu/hr)
       Equipment class        ----------------------------------------------------------------------------------
                                     Cat.              Size            2           6           7           9
----------------------------------------------------------------------------------------------------------------
SP.H.I.......................  Other...........  Large..........           0  ..........           0  ..........
                                                 Small..........           0  ..........           0  ..........
                               Sales...........  Large..........           0  ..........           0  ..........
                                                 Small..........           0  ..........           0  ..........
                               Service.........  Large..........           0  ..........           0  ..........
                                                 Small..........          74  ..........          26  ..........
SP.H.ID......................  Other...........  Large..........           0  ..........           0  ..........
                                                 Small..........           0  ..........           0  ..........
                               Sales...........  Large..........           0  ..........           0  ..........
                                                 Small..........           0  ..........           0  ..........
                               Service.........  Large..........           0  ..........           0  ..........
                                                 Small..........          74  ..........          26  ..........
SP.H.O.......................  Other...........  Large..........           0  ..........           0  ..........
                                                 Small..........           0  ..........           0  ..........
                               Sales...........  Large..........           0  ..........           0  ..........
                                                 Small..........           0  ..........           0  ..........
                               Service.........  Large..........           0  ..........           0  ..........
                                                 Small..........          22  ..........          78  ..........
SP.H.OD......................  Other...........  Large..........           0  ..........           0  ..........

[[Page 66720]]

 
                                                 Small..........           0  ..........           0  ..........
                               Sales...........  Large..........           0  ..........           0  ..........
                                                 Small..........           0  ..........           0  ..........
                               Service.........  Large..........           0  ..........           0  ..........
                                                 Small..........          22  ..........          78  ..........
SP.L.I.......................  Other...........  Large..........           0           0  ..........  ..........
                                                 Small..........           9           4  ..........  ..........
                               Sales...........  Large..........           0           0  ..........  ..........
                                                 Small..........          19           9  ..........  ..........
                               Service.........  Large..........           0           0  ..........  ..........
                                                 Small..........          41          18  ..........  ..........
SP.L.O.......................  Other...........  Large..........           0           0  ..........  ..........
                                                 Small..........           3           9  ..........  ..........
                               Sales...........  Large..........           0           0  ..........  ..........
                                                 Small..........           7          21  ..........  ..........
                               Service.........  Large..........           0           0  ..........  ..........
                                                 Small..........          15          45  ..........  ..........
SP.M.I.......................  Other...........  Large..........           0  ..........  ..........           0
                                                 Small..........           3  ..........  ..........          10
                               Sales...........  Large..........           0  ..........  ..........           0
                                                 Small..........           6  ..........  ..........          22
                               Service.........  Large..........           0  ..........  ..........           0
                                                 Small..........          14  ..........  ..........          46
SP.M.O.......................  Other...........  Large..........           0  ..........  ..........           0
                                                 Small..........           1  ..........  ..........          12
                               Sales...........  Large..........           0  ..........  ..........           0
                                                 Small..........           2  ..........  ..........          26
                               Service.........  Large..........           0  ..........  ..........           0
                                                 Small..........           3  ..........  ..........          56
----------------------------------------------------------------------------------------------------------------


                                                  Table II.7--Consumer Sample and Weights--Unit Coolers
                                                                           [%]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Sector                                             Capacity (kBtu/hr)
            Equipment class            -----------------------------------------------------------------------------------------------------------------
                                                   Cat.                       Size                 3           9          25          54          75
--------------------------------------------------------------------------------------------------------------------------------------------------------
UC.H.I *..............................  Other....................  Large....................  ..........           0           0  ..........  ..........
                                                                   Small....................  ..........           0           0  ..........  ..........
                                        Sales....................  Large....................  ..........           0           0  ..........  ..........
                                                                   Small....................  ..........           0           0  ..........  ..........
                                        Service..................  Large....................  ..........          30          11  ..........  ..........
                                                                   Small....................  ..........          43          16  ..........  ..........
UC.H.ID...............................  Other....................  Large....................  ..........           0           0  ..........  ..........
                                                                   Small....................  ..........           0           0  ..........  ..........
                                        Sales....................  Large....................  ..........           0           0  ..........  ..........
                                                                   Small....................  ..........           0           0  ..........  ..........
                                        Service..................  Large....................  ..........          30          11  ..........  ..........
                                                                   Small....................  ..........          43          16  ..........  ..........
UC.L.I................................  Other....................  Large....................          18          16           4          14           0
                                                                   Small....................           1           1           0           1           0
                                        Sales....................  Large....................           3           3           1           3           0
                                                                   Small....................           3           2           1           2           0
                                        Service..................  Large....................           4           3           1           3           0
                                                                   Small....................           6           5           1           5           0
UC.L.M................................  Other....................  Large....................           2          21          28           8           8
                                                                   Small....................           0           0           0           0           0
                                        Sales....................  Large....................           0           4           5           1           1
                                                                   Small....................           0           0           0           1           1
                                        Service..................  Large....................           0           5           6           2           2
                                                                   Small....................           1           0           0           2           2
UC.L.O................................  Other....................  Large....................           6          22           7           7          10
                                                                   Small....................           0           1           0           0           1
                                        Sales....................  Large....................           1           4           1           1           2
                                                                   Small....................           1           3           1           1           2
                                        Service..................  Large....................           1           5           2           2           2

[[Page 66721]]

 
                                                                   Small....................           2           7           2           2           3
UC.M.I................................  Other....................  Large....................          10          27           8           7           0
                                                                   Small....................           1           2           1           0           0
                                        Sales....................  Large....................           2           5           1           1           0
                                                                   Small....................           1           4           1           1           0
                                        Service..................  Large....................           2           6           2           1           0
                                                                   Small....................           3           9           2           2           0
UC.M.M................................  Other....................  Large....................           2          29          19           8           8
                                                                   Small....................           0           0           0           0           0
                                        Sales....................  Large....................           0           5           3           1           1
                                                                   Small....................           0           0           0           1           1
                                        Service..................  Large....................           0           6           4           2           2
                                                                   Small....................           1           0           0           2           2
--------------------------------------------------------------------------------------------------------------------------------------------------------
* For unit coolers, the index I, O, and M indicate that the unit cooler is connected to an Indoor, Outdoor, or Multiplex condensing system.

2. Equipment Lifetime
    When determining lifetimes, DOE calculates a Weibull distribution 
of potential lifetimes from average and maximum lifetime for the 
different types of equipment under consideration. In response to the 
June 2022 Preliminary Analysis, the CA IOUs suggested alternative 
lifetime estimates for walk-ins. As published data on WICF lifetimes 
are unavailable, the CA IOUs' lifetime estimates were sourced from 
technician interviews from a mechanical engineering firm. The stated 
lifetimes differ from those used by DOE in the June 2022 Preliminary 
Analysis,\12\ and September 2023 NOPR (88 FR 60746, 60798), and are 
shown in Table II.8 for comparison. (CA IOUs, No. 43 at pp. 17-18)
---------------------------------------------------------------------------

    \12\ See: June 2022 Preliminary Analysis Executive Summary, p. 
ES-20, June 2022 www.regulations.gov/document/EERE-2017-BT-STD-0009-0024.

                                      Table II.8--Estimated WICF Lifetimes
                                                     [Years]
----------------------------------------------------------------------------------------------------------------
                                                                DOE                           CA IOU
                                                 ---------------------------------------------------------------
               Equipment category                     Average         Maximum         Average         Maximum
                                                      (years)         (years)         (years)         (years)
----------------------------------------------------------------------------------------------------------------
Panels..........................................              12              25              20              25
Display Doors...................................              12              25               7              15
Non-display Doors...............................             8.5              12              10              15
Indoor Dedicated Condensing Systems.............            10.5              20              12              15
Outdoor Condensing Systems......................            10.5              20               6              15
Medium Temperature Unit Coolers.................            10.5              20              17              20
Low Temperature Unit Coolers....................            10.5              20              17           15-20
Sigle-packaged Condensing Systems...............            10.5              20            * 12            * 15
----------------------------------------------------------------------------------------------------------------
* Indicates that an estimate was not available, however commenters indicated that lifetimes would be like indoor-
  dedicated condensing systems.

    The CA IOUs' comment did not indicate if their interviewees were 
referencing lifetimes of walk-ins in the National scope or only 
California. DOE also notes that the very close average and maximum 
lifetime values for panels, indoor dedicated condensing systems, and 
unit coolers (medium-, and low-temperature) to be unlikely. DOE's 
lifetimes were initially determined in response to comments for the 
June 2014 Final Rule (79 FR 32086). Other than the information provided 
by the CA IOUs, DOE received comment from AHRI in response to the July 
2021 RFI in support of the existing lifetimes. (AHRI, No. 16 at p. 15) 
Given some of DOE's questions about the CA IOUs supplied lifetimes, DOE 
tentatively determined to maintain its use of the lifetimes from the 
June 2022 Preliminary Analysis in the September 2023 NOPR. DOE welcomes 
additional information on this topic in response to the September 2023 
NOPR.

E. Conclusion

    As discussed in the preceding sections, DOE has considered the 
comments provided by the CA IOUs in response to the June 2022 
Preliminary Analysis. This document provides responses to the CA IOUs' 
comments that were not included in the September 2023 NOPR, but does 
not change the analysis or proposals presented in the NOPR. DOE 
welcomes comment on the information presented in the September 2023 
NOPR, including the additional comment summaries and responses 
presented in this notification.

III. Procedural Issues and Regulatory Review

    DOE has concluded that the tentative determinations made pursuant 
to the various procedural requirements applicable to the September 2023 
NOPR remain unchanged for this notification. These tentative 
determinations are set

[[Page 66722]]

forth in the September 2023 NOPR. 88 FR 60746, 60855-60861.

IV. Public Participation

    Please refer to section VII of the September 2023 NOPR for 
information regarding the public webinar, submission of comments, and 
issues on which DOE seeks comment. 88 FR 60746, 60861-60863. DOE 
additionally welcomes comment on the information presented in this 
notification.

V. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this 
notification of data availability regarding energy conservation 
standards.

Signing Authority

    This document of the Department of Energy was signed on September 
21, 2023, by Jeffrey Marootian, Principal Deputy Assistant Secretary 
for Energy Efficiency and Renewable Energy, pursuant to delegated 
authority from the Secretary of Energy. That document with the original 
signature and date is maintained by DOE. For administrative purposes 
only, and in compliance with requirements of the Office of the Federal 
Register, the undersigned DOE Federal Register Liaison Officer has been 
authorized to sign and submit the document in electronic format for 
publication, as an official document of the Department of Energy. This 
administrative process in no way alters the legal effect of this 
document upon publication in the Federal Register.

    Signed in Washington, DC, on September 25, 2023.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
[FR Doc. 2023-21190 Filed 9-27-23; 8:45 am]
BILLING CODE 6450-01-P


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