[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
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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: [email protected]. 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:
[email protected].
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:
[email protected].
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: [email protected].
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)
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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.
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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
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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'').
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A parenthetical reference at the end of a comment quotation or
paraphrase provides the location of the item in the public record.\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.
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\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'').
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Refrigerants Analyzed
The CA IOUs commented that it expects that the use of R-404A to
estimate the performance of CO2-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
CO2. However, the CA IOUs recommended that DOE use
CO2 data in its analysis to avoid confusion. The CA IOUs
stated that DOE should use available CO2-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
CO2 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
CO2 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:
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.
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