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Proposed Rule2023-22149

Energy Conservation Program: Energy Conservation Standards for Consumer Furnace Fans

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Published

October 6, 2023

Issuing agencies

Energy Department

Abstract

The Energy Policy and Conservation Act, as amended ("EPCA"), prescribes energy conservation standards for various consumer products and certain commercial and industrial equipment, including consumer furnace fans. EPCA also requires the U.S. Department of Energy ("DOE") to periodically determine whether more-stringent, amended standards would be technologically feasible and economically justified, and would result in significant energy savings. In this notification of proposed determination ("NOPD"), DOE has initially determined that it could not conclude that amended standards would be cost effective, and thus, is not proposing to amend its energy conservation standards for these products. DOE requests comment on this proposed determination and the associated analyses and results.

Full Text

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[Federal Register Volume 88, Number 193 (Friday, October 6, 2023)]
[Proposed Rules]
[Pages 69826-69871]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-22149]

[[Page 69825]]

Vol. 88

Friday,

No. 193

October 6, 2023

Part III

Department of Energy

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10 CFR Part 430

Energy Conservation Program: Energy Conservation Standards for Consumer
Furnace Fans; Proposed Rule

Federal Register / Vol. 88, No. 193 / Friday, October 6, 2023 /
Proposed Rules

[[Page 69826]]

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DEPARTMENT OF ENERGY

10 CFR Part 430

[EERE-2021-BT-STD-0029]
RIN 1904-AE64

Energy Conservation Program: Energy Conservation Standards for
Consumer Furnace Fans

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

ACTION: Notification of proposed determination and request for comment.

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SUMMARY: The Energy Policy and Conservation Act, as amended (``EPCA''),
prescribes energy conservation standards for various consumer products
and certain commercial and industrial equipment, including consumer
furnace fans. EPCA also requires the U.S. Department of Energy
(``DOE'') to periodically determine whether more-stringent, amended
standards would be technologically feasible and economically justified,
and would result in significant energy savings. In this notification of
proposed determination (``NOPD''), DOE has initially determined that it
could not conclude that amended standards would be cost effective, and
thus, is not proposing to amend its energy conservation standards for
these products. DOE requests comment on this proposed determination and
the associated analyses and results.

DATES:
Meeting: DOE will hold a webinar upon request. Please request a
public webinar no later than October 20, 2023. See section VII,
``Public Participation,'' for webinar registration information,
participant instructions, and information about the capabilities
available to webinar participants.
Comments: Written comments and information are requested and will
be accepted on or before December 5, 2023.

ADDRESSES: Interested persons are encouraged to submit comments using
the Federal eRulemaking Portal at <a href="http://www.regulations.gov">www.regulations.gov</a> under docket
number EERE-2021-BT-STD-0029. Follow the instructions for submitting
comments.
Alternatively, interested persons may submit comments, identified
by docket number EERE-2021-BT-STD-0029, by any of the following
methods:
(1) Email: <a href="/cdn-cgi/l/email-protection#0744686974726a627541727569416669353735365453433737353e4762622963686229606871">[email&#160;protected]</a>. Include the
docket number EERE-2021-BT-STD-0029 in the subject line of the message.
(2) Postal Mail: Appliance and Equipment Standards Program, U.S.
Department of Energy, Building Technologies Office, Mailstop EE-5B,
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone:
(202) 287-1445. If possible, please submit all items on a compact disc
(``CD''), in which case it is not necessary to include printed copies.
(3) Hand Delivery/Courier: Appliance and Equipment Standards
Program, U.S. Department of Energy, Building Technologies Office, 950
L'Enfant Plaza SW, 6th Floor, Washington, DC 20024. Telephone: (202)
287-1445. If possible, please submit all items on a CD, in which case
it is not necessary to include printed copies.
No telefacsimiles (``faxes'') will be accepted. For detailed
instructions on submitting comments and additional information on this
process, see section VII of this document.
Docket: The docket, which includes Federal Register notices, public
meeting attendee lists and transcripts, comments, and other supporting
documents/materials, is available for review at <a href="http://www.regulations.gov">www.regulations.gov</a>.
All documents in the docket are listed in the <a href="http://www.regulations.gov">www.regulations.gov</a>
index. However, not all documents listed in the index may be publicly
available, such as information that is exempt from public disclosure.
The docket web page can be found at <a href="http://www.regulations.gov/docket/EERE-2021-BT-STD-0029">www.regulations.gov/docket/EERE-2021-BT-STD-0029</a>. The docket web page contains instructions on how
to access all documents, including public comments, in the docket. See
section VII, ``Public Participation,'' for further information on how
to submit comments through <a href="http://www.regulations.gov">www.regulations.gov</a>.

FOR FURTHER INFORMATION CONTACT:
Ms. Julia Hegarty, 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#430233332f2a222d20261037222d272231273012362630372a2c2d300326266d272c266d242c35">[email&#160;protected]</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#167b7762627e73613865757e78737f727364567e673872797338717960">[email&#160;protected]</a>.
For further information on how to submit a comment or review other
public comments and the docket contact the Appliance and Equipment
Standards Program staff at (202) 287-1445 or by email:
<a href="/cdn-cgi/l/email-protection#266756564a4f4748454375524748424754425577534355524f4948556643430842494308414950">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Synopsis of the Proposed Determination
II. Introduction
A. Authority
B. Background
1. Current Standards
2. History of Standards Rulemakings for Consumer Furnace Fans
C. Deviation From Appendix A of the Process Rule
III. General Discussion
A. General Comments
1. Comments Opposing Amended Standards for Furnace Fans
2. Comments Expressing Support for Amended Standards for Furnace
Fans
B. Product Classes and Scope of Coverage
C. Test Procedure
D. Technological Feasibility
1. General
2. Maximum Technologically Feasible Levels
E. Cost Effectiveness
F. Energy Savings
1. Determination of Savings
2. Significance of Savings
G. Additional Considerations
IV. Methodology and Discussion of Related Comments
A. Market and Technology Assessment
1. Scope of Coverage
2. Technology Options
3. Impact From Other Rulemakings
a. Screened-Out Technologies
b. Remaining Technologies
4. Product Classes
B. Engineering Analysis
1. Efficiency Analysis
a. Baseline Efficiency Level
b. Intermediate Efficiency Levels
c. Maximum Technology Efficiency Levels
d. Summary of Efficiency Levels Analyzed
2. Cost Analysis
a. Teardown Analysis
b. Cost Estimation Method
3. Cost-Efficiency Results
C. Markups Analysis
D. Energy Use Analysis
E. Life-Cycle Cost and Payback Period Analysis
1. Product Cost
2. Installation Cost
3. Annual Energy Consumption
4. Energy Prices
5. Maintenance and Repair Costs
6. Product Lifetime
7. Discount Rates
8. Energy Efficiency Distribution in the No-New-Standards Case
9. Payback Period Analysis
F. Shipments Analysis
G. National Impact Analysis
1. Product Efficiency Trends
2. National Energy Savings
3. Net Present Value Analysis
H. Further Considerations Related to Backward-Inclined Impellers
V. Analytical Results and Conclusions
A. Economic Impacts on Individual Consumers
B. National Impact Analysis
1. Significance of Energy Savings
2. Net Present Value of Consumer Costs and Benefits

[[Page 69827]]

C. Proposed Determination
1. BPM Motor With Backward-Inclined Impellers
2. BPM Motor With Forward-Curved Impellers
3. Summary
VI. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866, 13563, and 14094
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under the Treasury and General Government
Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under the Information Quality Bulletin for Peer Review
VII. Public Participation
A. Participation in the Webinar
B. Submission of Comments
C. Issues on Which DOE Seeks Comment
VIII. Approval of the Office of the Secretary

I. Synopsis of the Proposed Determination

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 B of EPCA \2\ established the Energy
Conservation Program for Consumer Products Other Than Automobiles. (42
U.S.C. 6291-6309) These products include consumer furnace fans, the
subject of this NOPD. (42 U.S.C. 6295(f)(4)(D))
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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 B was redesignated Part A.
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DOE is issuing this NOPD pursuant to the EPCA requirement that not
later than 6 years after issuance of any final rule establishing or
amending a standard, DOE must publish either a notification of
determination that standards for the product do not need to be amended,
or a notice of proposed rulemaking (``NOPR'') including new proposed
energy conservation standards (proceeding to a final rule, as
appropriate). (42 U.S.C. 6295(m))
For this proposed determination, DOE analyzed consumer furnace fans
subject to standards specified in 10 CFR 430.32(y). DOE first analyzed
the technological feasibility of more energy efficient consumer furnace
fans. For those consumer furnace fans for which DOE determined higher
standards to be technologically feasible, DOE evaluated whether higher
standards would be cost effective by conducting life-cycle cost
(``LCC'') and payback period (``PBP'') analyses. In addition, DOE
estimated energy savings that would result from potential energy
conservation standards by conducting a national impacts analysis
(``NIA''), in which it estimated the net present value (``NPV'') of the
total costs and benefits experienced by consumers.
Based on the results of the analyses, summarized in section V of
this document, DOE has tentatively determined that current standards
for consumer furnace fans do not need to be amended.

II. Introduction

The following section briefly discusses the statutory authority
underlying this proposed determination, as well as some of the
historical background relevant to the establishment of standards for
consumer furnace fans.

A. Authority

EPCA authorizes DOE to regulate the energy efficiency of a number
of consumer products and certain industrial equipment. Title III, Part
B of EPCA established the Energy Conservation Program for Consumer
Products Other Than Automobiles. These products include consumer
furnace fans, the subject of this document. (42 U.S.C. 6295(f)(4)(D))
Specifically, EPCA authorized DOE to establish energy conservation
standards for electricity used for purpose of circulating air through
duct work. (Id.)
The energy conservation program under EPCA consists essentially of
four parts: (1) testing, (2) labeling, (3) the establishment of Federal
energy conservation standards, and (4) certification and enforcement
procedures. Relevant provisions of EPCA specifically include
definitions (42 U.S.C. 6291), test procedures (42 U.S.C. 6293),
labeling provisions (42 U.S.C. 6294), energy conservation standards (42
U.S.C. 6295), and the authority to require information and reports from
manufacturers (42 U.S.C. 6296).
Subject to certain criteria and conditions, DOE is required to
develop test procedures to measure the energy efficiency, energy use,
or estimated annual operating cost of each covered product. (42 U.S.C.
6295(o)(3)(A) and 42 U.S.C. 6295(r)) Manufacturers of covered products
must use the prescribed DOE test procedure as the basis for certifying
to DOE that their products comply with the applicable energy
conservation standards adopted under EPCA and when making
representations to the public regarding the energy use or efficiency of
those products. (42 U.S.C. 6293(c) and 42 U.S.C. 6295(s)) Similarly,
DOE must use these test procedures to determine whether the products
comply with standards adopted pursuant to EPCA. (42 U.S.C. 6295(s)) The
DOE test procedures for consumer furnace fans appear at title 10 of the
Code of Federal Regulations (``CFR'') part 430, subpart B, appendix AA.
Federal energy conservation requirements generally supersede State
laws or regulations concerning energy conservation testing, labeling,
and standards. (42 U.S.C. 6297(a)-(c)) DOE may, however, grant waivers
of Federal preemption for particular State laws or regulations, in
accordance with the procedures and other provisions set forth under
EPCA. (See 42 U.S.C. 6297(d))
Pursuant to the amendments contained in the Energy Independence and
Security Act of 2007 (EISA 2007), Public Law 110-140, any final rule
for new or amended energy conservation standards promulgated after July
1, 2010, is required to address standby mode and off mode energy use.
(42 U.S.C. 6295(gg)(3)) Specifically, when DOE adopts a standard for a
covered product after that date, it must, if justified by the criteria
for adoption of standards under EPCA (42 U.S.C. 6295(o)), incorporate
standby mode and off mode energy use into a single standard, or, if
that is not feasible, adopt a separate standard for such energy use for
that product. (42 U.S.C. 6295(gg)(3)(A)-(B)) However, DOE has
previously determined that there is no need to address standby and off
mode energy use in the standards for consumer furnace fans, as the
standby mode and off mode energy use associated with furnace fans is
accounted for by the standards and test procedures for the products in
which furnace fans are used (i.e., consumer furnaces and consumer
central air conditioners and heat pumps). 79 FR 499, 504. DOE
maintained the same approach in the proposed amended test procedure for
consumer furnace fans (the ``May 2022 TP NOPR''). 87 FR 29576.
DOE must periodically review its already established energy
conservation standards for consumer furnace fans no later than 6 years
from the issuance of a final rule establishing or amending a standard
for consumer furnace fans. (42

[[Page 69828]]

U.S.C. 6295(m)) This 6-year look-back provision requires that DOE
publish either a determination that standards do not need to be amended
or a NOPR, including new proposed standards (proceeding to a final
rule, as appropriate). (42 U.S.C. 6295(m)(1)) EPCA further provides
that, not later than 3 years after the issuance of a final
determination not to amend standards, DOE must publish either a
notification of determination that standards for the product do not
need to be amended, or a NOPR including new proposed energy
conservation standards (proceeding to a final rule, as appropriate).
(42 U.S.C. 6295(m)(3)(B)) DOE must make the analysis on which a
determination is based publicly available and provide an opportunity
for written comment. (42 U.S.C. 6295(m)(2))
A determination that amended standards are not needed must be based
on consideration of whether amended standards will result in
significant conservation of energy, are technologically feasible, and
are cost effective. (42 U.S.C. 6295(m)(1)(A) and 42 U.S.C. 6295(n)(2))
Under 42 U.S.C. 6295(o)(2)(B)(i)(II), an evaluation of cost-
effectiveness requires DOE to consider savings in operating costs
throughout the estimated average life of the covered products in the
type (or class) compared to any increase in the price, initial charges,
or maintenance expenses for the covered products that are likely to
result from the standard. (42 U.S.C. 6295(n)(2) and 42 U.S.C.
6295(o)(2)(B)(i)(II)) DOE is publishing this NOPD in satisfaction of
the 6-year review requirement in EPCA. (42 U.S.C. 6295(m))

B. Background

1. Current Standards
In a final rule published on July 3, 2014 (``July 2014 Final
Rule''), DOE prescribed the current energy conservation standards for
consumer furnace fans manufactured on and after July 3, 2019. 79 FR
38130. These standards are set forth in DOE's regulations at 10 CFR
430.32(y) and are repeated in Table II.1.

Table II.1--Federal Energy Conservation Standards for Consumer Furnace
Fans
------------------------------------------------------------------------
Fan energy rating (``FER'')
Furnace fan product class (watts/1000 cubic feet per
minute (``cfm''))
------------------------------------------------------------------------
Non-Weatherized, Non-Condensing Gas (``NWG- FER = 0.044 * Qmax + 182.
NC'').
Non-Weatherized, Condensing Gas (``NWG-C'') FER = 0.044 * Qmax + 195.
Weatherized, Non-Condensing Gas (``WG-NC'') FER = 0.044 * Qmax + 199.
Non-Weatherized, Non-Condensing Oil Furnace FER = 0.071 * Qmax + 382.
Fan (``NWO-NC'').
Non-Weatherized Electric Furnace/Modular FER = 0.044 * Qmax + 165.
Blower Fan (``NWEF/NWMB'').
Mobile Home Non-Weatherized, Non-Condensing FER = 0.071 * Qmax + 222.
Gas Furnace Fan (``MH-NWG-NC'').
Mobile Home Non-Weatherized, Condensing Gas FER = 0.071 * Qmax + 240.
Furnace Fan (``MH-NWG-C'').
Mobile Home Electric Furnace/Modular Blower FER = 0.044 * Qmax + 101.
Fan (``MH-EF/MB'').
Mobile Home Non-Weatherized Oil Furnace Fan Reserved.
(``MH-NWO'').
Mobile Home Weatherized Gas Furnace Fan Reserved.
(``MH-WG'').
------------------------------------------------------------------------

2. History of Standards Rulemakings for Consumer Furnace Fans
DOE established energy conservation standards at 10 CFR 430.32(y)
for furnace fans through a final rule published in the Federal Register
on July 3, 2014 (``July 2014 Final Rule''). 79 FR 38130. As discussed
in section II.A of this document, EPCA authorized DOE to establish
energy conservation standards for electricity used for purpose of
circulating air through duct work. (42 U.S.C. 6295(f)(4)(D)) While the
statutory language allows for regulation of the electricity use of any
electrically-powered device applied to residential central heating,
ventilation, and air conditioning (``HVAC'') systems for the purpose of
circulating air through duct work, in the July 2014 Final Rule DOE
established standards only for certain furnace fans used in furnaces
and modular blowers. 79 FR 38130, 38146. Compliance with the prescribed
standards established for consumer furnace fans in the July 2014 Final
Rule was required as of July 3, 2019. DOE's energy conservation
standards for furnace fans use the fan energy rating (``FER'') metric,
which is the ratio of the electrical energy consumption to airflow,
expressed as watts per 1,000 cubic feet per minute of airflow (``W/1000
cfm''). 10 CFR 430.32(y). In evaluating whether amended standards for
furnace fans are warranted, DOE used the test procedure for determining
FER is established at 10 CFR part 430 subpart B appendix AA, Uniform
Test Method for Measuring the Energy Consumption of Furnace Fans
(``appendix AA''). In parallel to this rulemaking, DOE is considering
whether amendments are warranted for the current test procedure for
furnace fans. On May 13, 2022, DOE published a notice of proposed
rulemaking (``NOPR'') concerning the test procedure for furnace fans
(``May 2022 TP NOPR''). 87 FR 29576.
In support of the present review of the consumer furnace fans
energy conservation standards, DOE published a request for information
(``RFI''), which identified various issues on which DOE sought comment
to inform its determination of whether the standards need to be amended
on November 23, 2021 (the ``November 2021 RFI''). 86 FR 66465. The
following year, on November 1, 2022, DOE published a notice of
availability of the preliminary technical support document (the
``November 2022 Preliminary Analysis'') in the Federal Register. 87 FR
65687. In the November 2022 Preliminary Analysis, DOE assessed
potential amended standard levels for consumer furnace fans.
On September 20, 2022, a consent decree was issued for NRDC et al.
v. DOE and New York et al. v. DOE that mandated that a final agency
action pertaining to energy conservation standards (i.e., a final rule
amending energy conservation standards or a final determination not to
amend standards) must be issued by October 31, 2024.
DOE received comments in response to the November 2022 Preliminary
Analysis from the interested parties listed in Table II.2.

[[Page 69829]]

Table II.2--November 2022 Preliminary Analysis Comments
----------------------------------------------------------------------------------------------------------------
Reference in this Comment No. in
Commenter(s) NOPD the docket Commenter type
----------------------------------------------------------------------------------------------------------------
Air Conditioning, Heating and AHRI................ 23 Trade Association.
Refrigeration Institute.
Appliance Standards Awareness Joint Commenters.... 20 Efficiency Organization.
Project, American Council for an
Energy-Efficient Economy,
National Consumer Law Center,
Natural Resources Defense Council.
Carrier Global Corporation........ Carrier............. 19 Manufacturer.
Charles Beach..................... Beach............... 16 Individual.
Daikin Comfort Technologies....... Daikin.............. * 26 Manufacturer.
Lennox International Inc.......... Lennox.............. 24 Manufacturer.
Morrison Products Inc............. Morrison............ 27 Manufacturer.
Nidec Motors...................... Nidec............... * 26 Manufacturer.
Northwest Energy Efficiency NEEA................ 25 Efficiency Organization.
Alliance.
Pacific Gas and Electric Company, CA IOUs............. 21 Utility.
San Diego Gas and Electric,
Southern California Edison.
Rheem Manufacturing Company....... Rheem............... * 26 Manufacturer.
Trane Technologies................ Trane............... 22 Manufacturer.
Weil-McLain Technologies.......... Weil-McLain......... * 26 Manufacturer.
----------------------------------------------------------------------------------------------------------------
* Comment No. 26 corresponds to the transcript for the webinar held December 5, 2022. These commenters made oral
comments during the public meeting that are summarized and discussed in this document.

Any oral comments provided during the webinar that are not
substantively addressed by written comments are summarized and cited
separately throughout this NOPD. A parenthetical reference at the end
of a comment quotation or paraphrase provides the location of the item
in the public record.\3\
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\3\ The parenthetical reference provides a reference for
information located in the docket. (Docket No., which is maintained
at <a href="http://www.regulations.gov">www.regulations.gov</a>). The references are arranged as follows:
(commenter name, comment docket ID number, page of that document).
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C. Deviation From Appendix A of the Process Rule

In accordance with section 3(a) of 10 CFR part 430, subpart C,
appendix A (``appendix A''), DOE notes that it is deviating from the
provision in the appendix A regarding the pre-NOPR and NOPR stages for
an energy conservation standards rulemaking.
Section 6(f)(2) of the appendix A specifies that the length of the
public comment period for a NOPR will be not less than 75 calendar
days. For this NOPD, DOE has opted instead to provide a 60-day comment
period, as required by EPCA. 42 U.S.C. 6295(p). DOE is opting to
deviate from the 75-day comment period because stakeholders have
already been afforded an opportunity to provide comments on this
rulemaking. As noted previously, DOE requested comment on various
issues pertaining to this standards rulemaking in the November 2021
RFI, a November 2022 preliminary analysis, and collectively provided
stakeholders with more than a 90 days to comment. 86 FR 66465 and 87 FR
65687. Therefore, DOE believes a 60-day comment period is appropriate
and will provide interested parties with a meaningful opportunity to
comment on the proposed determination.

III. General Discussion

DOE developed this proposed determination after considering
comments, data, and information from interested parties that represent
a variety of interests. This notice addresses issues raised by these
commenters.

A. General Comments

1. Comments Opposing Amended Standards for Furnace Fans
In response to the November 2022 Preliminary Analysis, several
commenters expressed opposition to amending standards for consumer
furnace fans.
Trane commented that it does not support adopting efficiency level
(``EL'') 1 for consumer furnace fan standards because the assumptions
used in the TSD are flawed and when corrected will result in much
smaller energy savings, higher consumer costs, and undue burden to
manufacturers who will need to redesign all furnaces to adopt backward-
inclined impellers. (Trane, No. 22 at p. 1) Trane commented that EL 1
analyzed in the November 2022 Preliminary Analysis fails to meet: (1)
the energy savings threshold because the energy savings outlined in the
TSD are overstated; (2) the technological feasibility requirement
because there is a need for additional technology development before EL
1 is feasible; and (3) the economic justification criteria.
Specifically, Trane stated that EL 1 is not economically justified for
the following reasons: (1) the negative economic impact will be
significant in terms of manufacturer redesign costs (for relatively
small energy savings); (2) consumers will face higher product and
installation costs; (3) consumers will encounter negative lifetime
operating cost savings and energy savings will be lower than DOE
predicted; (4) there will be negative impacts on safety and efficiency
due to changes in airflow patterns (impacting utility or performance);
and (5) the potential for lessening of competition will be increased
because units with backward-inclined impellers do not currently exist.
Trane therefore commented that the use of EL 1 should not be considered
for furnace fans. (Id. at p. 4) Morrison commented that DOE's values
for the product cost increase were undercounted, the energy savings
were overestimated, and the resulting benefit to consumers would be
half of the values that DOE projects. Therefore, Morrison concluded
that DOE underestimated the LCC and PBP in the November 2022
Preliminary Analysis, and that the actual numbers will reflect a net
cost for more consumers than currently projected. (Morrison, No. 27 at
p. 4) Lennox recommended DOE conclude that no new furnace fan standards
are warranted for the NWG-NC, NWG-C, and WG-NC product classes due to
very high levels of consumers experiencing net costs from potential
amended standards. Lennox noted that for NWG-NC and NWG-C, 44 percent
and 48 percent, respectively, of consumers experience a net cost, while
for WG-NC, 26 percent of consumers experience a net cost. Lennox also
commented that for the NWO-NC product class, although the payback
period and percent of consumers experiencing a net cost are favorable
for

[[Page 69830]]

EL 1, the energy savings associated with these products is minimal
(0.00003 quads) and does not meet the criteria of significant energy
savings, and therefore amended standards are not likely warranted.
(Lennox, No. 24 at p. 2) Lennox also commented that the feasible
technologies available for furnace fans have not changed since the last
furnace fan standards rulemaking in 2019, but equipment costs have
increased over the same time period due to inflation and supply chain
issues. Lennox stated that many consumers have been adversely impacted
by the COVID-19 pandemic, and increasing furnace fan equipment costs
with new efficiency standards is both ill-advised and economically
unjustified at this time. (Id. at p. 2)
AHRI stated that while the simple payback period of many maximum
technology feasible (``max-tech'') furnace fans appears to be
favorable, almost every class of fan provides minimal average cost
savings to consumers and projections showing that, in all but one case,
over 44 percent of consumers will experience a net cost. AHRI commented
that this cost, combined with AHRI's concerns about the
misrepresentation of the cost of products with a backward-inclined
impeller, lead AHRI to expect that the true percentage of affected
consumers will be higher than stated. (AHRI, No. 23 at p. 3)
Morrison recommended that DOE consider the timing and length of
analysis periods for complex rulemaking documents, as the public
comment period for this rulemaking was at a time of year in which
under-staffing is common, and, as a result, Morrison stated that it is
unable to guarantee the thoroughness and attention to detail of its
response to this rulemaking. (Morrison, No. 27 at p. 6)
As discussed in section II.A of this document, DOE must
periodically review its already established energy conservation
standards for consumer furnace fans no later than 6 years from the
issuance of a final rule establishing or amending a standard for
consumer furnace fans. This 6-year look-back provision requires that
DOE publish either a determination that standards do not need to be
amended or a NOPR, including new proposed standards (proceeding to a
final rule, as appropriate). (42 U.S.C. 6295(m)(1)) Additionally, EPCA
provides specific statutory criteria for amending energy conservation
standards. EPCA generally requires a public notice-and-comment process
(see 42 U.S.C. 6295(p)), which affords members of the public the
opportunity to comment on the rulemaking and all documents are made
publicly available at <a href="http://www.regulations.gov">www.regulations.gov</a>. As part of the process for
this rulemaking, DOE carefully considers the benefits and burdens of
amended standards to determine whether the amended standards are the
maximum standard levels that are technologically feasible and
economically justified, and would conserve a significant amount of
energy, as required by EPCA (see 42 U.S.C. 6295(o)(2)-(3)). Section IV
of this document outlines DOE's approach to analyzing various potential
amended standard levels, which was conducted in accordance with the
statutory requirements outlined in EPCA (and described above) for
determining whether to establish or amend standards. Section V of this
document provides the results of those analyses, as well as a detailed
explanation of DOE's weighing of the benefits and burdens and the
rationale for proposing not to amend standards for consumer furnace
fans at this time based on the criteria specified in EPCA. Morrison
stated that having separate measures of energy efficiency for furnaces
and furnace fans may risk confusing consumers as to which efficiency
label they should choose when purchasing equipment, in turn increasing
the potential for wasted energy. (Morrison, No. 27 at p. 2) Lennox
similarly commented that when consumers consider energy efficiency
while purchasing residential furnaces, they evaluate the annual fuel
utilization efficiency (``AFUE'') metric for consumer furnaces. Lennox
commented that furnace fans typically account for less than 2 percent
of the overall energy use of a residential furnace system in heating
operation, and DOE furnace fan standards are not a focus of the
consumer purchase decision. (Lennox, No. 24 at p. 8)
In response, DOE notes that EPCA directed DOE to consider and
prescribe energy conservation standards or energy use standards for
electricity used for the purposes of circulating air through ductwork.
(42 U.S.C. 6295(f)(4)(D)) The AFUE metric used for furnaces does not
account for the electricity used by the furnace fan to move air through
ductwork. Therefore, to satisfy the requirements of EPCA, DOE
established the FER test method and metric to account for the
electrical energy consumption for circulating air through ductwork and
will maintain AFUE and FER as separate metrics for consumer furnaces
and consumer furnace fans, respectively.
2. Comments Expressing Support for Amended Standards for Furnace Fans
In response to the November 2022 Preliminary Analysis, several
commenters encouraged DOE to amend standards for consumer furnace fans.
The CA IOUs commented that DOE's analyses show significant
lifetime-operating-cost savings and short-payback periods for the NWO-
NC, MH-NWG-NC, MH-NWG-C, and MH-NWO-NC product classes. (CA IOUs, No.
21 at p. 1) The CA IOUs stated that they support DOE's finding that
brushless permanent magnet (``BPM'') motors are cost-effective for all
product classes. (Id. at p. 1)
NEEA recommended that DOE adopt a BPM standard level for all
equipment classes, including those DOE proposed in the expansion and
for any additional classes that DOE could cover. NEEA commented that by
raising the standard to BPM motors beyond non-weatherized gas furnaces,
DOE would ensure that there are fewer applications where inefficient
furnace fans are being used in the market. NEEA further commented that
the market for BPM motors is mature, and the adoption of additional
product classes should not negatively impact manufacturers. (NEEA, No.
24 at p. 3)
As part of the rulemaking process, DOE carefully considers the
benefits and burdens of potential amended standards to determine
whether the potential amended standards are the maximum standard levels
that are technologically feasible and economically justified, and would
conserve a significant amount of energy, as required by EPCA (see 42
U.S.C. 6295(o)(2)-(3)). Section IV of this document outlines DOE's
approach to analyzing various potential amended standard levels, and
section V of this document provides the results of those analyses, as
well as a detailed explanation of DOE's weighing of the benefits and
burdens and the rationale for proposing not to amend standards for
consumer furnace fans.

B. Product Classes and Scope of Coverage

When evaluating and establishing energy conservation standards, DOE
divides covered products into product classes by the type of energy
used or by capacity or other performance-related features that justify
differing standards. In making a determination whether a performance-
related feature justifies a different standard, DOE must consider such
factors as the utility of the feature to the consumer and other factors
DOE determines are appropriate. (42 U.S.C.

[[Page 69831]]

6295(q)) The scope of coverage and product classes for this proposed
determination are discussed in further detail in section IV.A.1 and
IV.A.4, respectively. This proposed determination covers consumer
furnace fans defined as an electrically-powered device used in a
consumer product for the purpose of circulating air through ductwork.
10 CFR 430.2.

C. Test Procedure

EPCA sets forth generally applicable criteria and procedures for
DOE's adoption and amendment of test procedures. (42 U.S.C. 6293)
Manufacturers of covered products must use these test procedures to
certify to DOE that their product complies with energy conservation
standards and to quantify the efficiency of their product. (42 U.S.C.
6295(s) and 42 U.S.C. 6293(c)) The test procedure for determining FER
is established at 10 CFR part 430 subpart B appendix AA, Uniform Test
Method for Measuring the Energy Consumption of Furnace Fans (``appendix
AA''). On May 13, 2022, DOE published the May 2022 TP NOPR, which
proposed to amend the test procedure for consumer furnace fans. 87 FR
29576. Specifically, the May 2022 TP NOPR proposed the following
changes: (1) Specify testing instructions for furnace fans incapable of
operating at the required external static pressure (``ESP''). (2)
Incorporate by reference the most recent versions of industry
standards, ASHRAE 103-2017 and ASHRAE 37-2009 (RA 2019), in 10 CFR
430.3. (3) Define dual-fuel furnace fans and exclude them from the
scope of appendix AA. (4) Change the term ``default airflow control
settings'' to ``specified airflow control settings.'' (5) Add
provisions to directly measure airflow. (6) Revise the ambient
temperature conditions allowed during testing to between 65 degrees
Fahrenheit (``[deg]F'') and 85 [deg]F for all units (both condensing
and non-condensing). (7) Assign an allowable range of relative humidity
during testing to be between 20 percent and 80 percent. Id. at 25979.
DOE is still considering comments received in response to the May 2022
TP NOPR and has not yet finalized any updates to the test procedure.

D. Technological Feasibility

1. General
In evaluating potential amendments to energy conservation
standards, DOE conducts a screening analysis based on information
gathered on all current technology options and prototype designs that
could improve the efficiency of the products or equipment that are the
subject of the determination. As the first step in such an analysis,
DOE develops a list of technology options for consideration in
consultation with manufacturers, design engineers, and other interested
parties. DOE then determines which of those means for improving
efficiency are technologically feasible. DOE considers technologies
incorporated in commercially available products or in working
prototypes to be technologically feasible. Sections 6(b)(3)(i) and
7(b)(1) of appendix A to 10 CFR part 430 subpart C (``Process Rule'').
After DOE has determined that particular technology options are
technologically feasible, it further evaluates each technology option
in light of the following additional screening criteria: (1)
practicability to manufacture, install, and service; (2) adverse
impacts on product utility or availability; (3) adverse impacts on
health or safety; and (4) unique-pathway proprietary technologies.
Sections 6(b)(3)(ii)-(v) and 7(b)(2)-(5) of the Process Rule. Section
IV.A.4 of this document discusses the results of the screening analysis
for consumer furnace fans, particularly the designs DOE considered,
those it screened out, and those that are the basis for the standards
considered in this proposed determination.
2. Maximum Technologically Feasible Levels
As when DOE proposes to adopt a new or amended standard for a type
or class of covered product, in this analysis it must determine the
maximum improvement in energy efficiency or maximum reduction in energy
use that is technologically feasible for such a product. (42 U.S.C.
6295(p)(1)) Accordingly, in the engineering analysis, DOE determined
the maximum technologically feasible improvements in energy efficiency
for consumer furnace fans, using the design parameters for the most
efficient products available on the market or in working prototypes.
The max-tech levels that DOE determined for this analysis are described
in section IV.B of this proposed determination.

E. Cost Effectiveness

In making a determination of whether amended energy conservation
standards are needed, EPCA requires DOE to consider the cost
effectiveness of amended standards in the context of the savings in
operating costs throughout the estimated average life of the covered
product compared to any increase in the price of, or in the initial
charges for, or maintenance expenses of, the covered product that are
likely to result from a standard. (42 U.S.C. 6295(o)(2)(B)(i)(II))
In determining cost effectiveness of amending standards for
consumer furnace fans, DOE conducted LCC and PBP analyses that estimate
the costs and benefits to users from potential standards. To further
inform DOE's consideration of the cost effectiveness of potential
amended standards, DOE considered the NPV of total costs and benefits
estimated as part of the NIA. The inputs for determining the NPV of the
total costs and benefits experienced by consumers are (1) total annual
installed cost, (2) total annual operating costs (energy costs and
repair and maintenance costs), and (3) a discount factor to calculate
the present value of costs and savings.

F. Energy Savings

1. Determination of Savings
For each efficiency level (``EL'') evaluated, DOE projected energy
savings from application of the EL to the consumer furnace fans
purchased in the 30-year period that begins in the assumed year of
compliance with the potential standards (2030-2059). The savings are
measured over the entire lifetime of the consumer furnace fans
purchased in the previous 30-year period. DOE quantified the energy
savings attributable to each EL as the difference in energy consumption
between each standards case and the no-new-standards case. The no-new-
standards case represents a projection of energy consumption that
reflects how the market for a product would likely evolve in the
absence of amended energy conservation standards. DOE used its NIA
spreadsheet model to estimate national energy savings (NES) from
potential amended or new standards for consumer furnace fans. The NIA
spreadsheet model (described in section IV.G of this document)
calculates energy savings in terms of site energy, which is the energy
directly consumed by products at the locations where they are used. For
electricity, DOE reports NES in terms of primary energy savings, which
is the savings in the energy that is used to generate and transmit the
site electricity. DOE also calculates NES in terms of full-fuel-cycle
(FFC) energy savings. The FFC metric includes the energy consumed in
extracting, processing, and transporting primary fuels (i.e., coal,
natural gas, petroleum fuels), and thus presents a more complete
picture of the impacts of

[[Page 69832]]

energy conservation standards.\4\ DOE's approach is based on the
calculation of an FFC multiplier for each of the energy types used by
covered products or equipment. For more information on FFC energy
savings, see section IV.G of this document.
---------------------------------------------------------------------------

\4\ The FFC metric is discussed in DOE's statement of policy and
notice of policy amendment. 76 FR 51282 (Aug. 18, 2011), as amended
at 77 FR 49701 (Aug. 17, 2012).
---------------------------------------------------------------------------

2. Significance of Savings
In determining whether amended standards are needed, DOE must
consider whether such standards will result in significant conservation
of energy. (42 U.S.C. 6295(m)(1)(A)) The significance of energy savings
offered by a new or amended energy conservation standard cannot be
determined without knowledge of the specific circumstances surrounding
a given rulemaking.\5\ For example, some covered products and equipment
have most of their energy consumption occur during periods of peak
energy demand. The impacts of these products on the energy
infrastructure can be more pronounced than products with relatively
constant demand. Accordingly, DOE evaluates the significance of energy
savings on a case-by-case basis.
---------------------------------------------------------------------------

\5\ The numeric threshold for determining the significance of
energy savings established in a final rule published on February 14,
2020 (85 FR 8626, 8670) was subsequently eliminated in a final rule
published on December 13, 2021 (86 FR 70892).
---------------------------------------------------------------------------

G. Additional Considerations

Pursuant to EPCA, absent DOE publishing a notification of
determination that energy conservation standards for furnace fans do
not need to be amended, DOE must issue a NOPR that includes new
proposed standards. (42 U.S.C. 6295(m)(1)(B)). The new proposed
standards in any such NOPR must be based on the criteria established
under 42 U.S.C. 6295(o) and follow the procedures established under 42
U.S.C. 6295(p). (42 U.S.C. 6295(m)(1)(B)). The criteria in 42 U.S.C.
6295(o) require that standards be designed to achieve the maximum
improvement in energy efficiency, which the Secretary determines is
technologically feasible and economically justified. (42 U.S.C.
6295(o)(2)(A)). In deciding whether a proposed standard is economically
justified, DOE must determine whether the benefits of the standard
exceed its burdens. (42 U.S.C. 6295(o)(2)(B)(i)). DOE must make this
determination after receiving comments on the proposed standard, and by
considering, to the greatest extent practicable, the following seven
statutory factors:
(1) The economic impact of the standard on manufacturers and
consumers of the products subject to the standard;
(2) The savings in operating costs throughout the estimated average
life of the covered products in the type (or class) compared to any
increase in the price, initial charges for, or maintenance expenses of
the covered products that are likely to result from the standard;
(3) The total projected amount of energy (or as applicable, water)
savings likely to result directly from the standard;
(4) Any lessening of the utility or the performance of the covered
products likely to result from the standard;
(5) The impact of any lessening of competition, as determined in
writing by the Attorney General, that is likely to result from the
standard;
(6) The need for national energy and water conservation; and
(7) Other factors the Secretary considers relevant.

(42 U.S.C. 6295(o)(2)(B)(i)(I)-(VII))

IV. Methodology and Discussion of Related Comments

This section addresses the analyses DOE has performed for this
proposed determination with regard to consumer furnace fans. Separate
subsections address each component of DOE's analyses. DOE used several
analytical tools to estimate the impact of potential energy
conservation standards. The first tool is a spreadsheet that calculates
the LCC savings and PBP of potential energy conservation standards. The
NIA uses a second spreadsheet set that provides shipments projections
and calculates NES and net present value of total consumer costs and
savings expected to result from potential energy conservation
standards. These spreadsheet tools are available on the website:
<a href="http://www.regulations.gov/docket/EERE-2021-BT-STD-0029">www.regulations.gov/docket/EERE-2021-BT-STD-0029</a>.

A. Market and Technology Assessment

DOE develops information in the market and technology assessment
that provides an overall picture of the market for the products
concerned, including the purpose of the products, the industry
structure, manufacturers, market characteristics, and technologies used
in the products. 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 proposed determination include (1) a determination
of the scope and product 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 consumer furnace fans. The
key findings of DOE's market assessment are summarized in the following
sections.
1. Scope of Coverage
In this analysis, DOE relied on the definition of consumer furnace
fans in 10 CFR 430.2, which defines a consumer furnace fan as an
electrically-powered device used in a consumer product for the purpose
of circulating air through ductwork. Any product meeting the definition
of consumer furnace fans is included in DOE's scope of coverage, though
not all products within the scope of coverage may be subject to
standards.
For this NOPD, DOE evaluated products within the same scope as
those products for which DOE initially established energy conservation
standards in the final rule published on July 3, 2014 (``July 2014
Final Rule''). 79 FR 38130. Products evaluated in this NOPD include:
<bullet> Furnace fans used in weatherized and non-weatherized gas
furnaces, oil furnaces, and electric furnaces; and
<bullet> Modular blowers.
Consistent with the approach taken in the July 2014 Final Rule,
products not addressed in this rulemaking include:
<bullet> Furnace fans used in other products, such as split-system
central air conditioner (``CAC'') and heat pump indoor units, through-
the-wall indoor units, small duct high-velocity indoor units, energy
recovery ventilators, heat recovery ventilators, draft inducer fans,
exhaust fans, or hydronic air handlers; and
<bullet> Fans used in any non-ducted products, such as whole-house
ventilation systems without ductwork, CAC condensing unit fans, room
fans, and furnace draft inducer fans because these products do not
circulate air through ductwork.
DOE has previously determined that the DOE test procedure for
furnace fans is not currently equipped to address fans contained in
CACs, heat pumps, or other products. 79 FR 38130, 38149. Therefore, DOE
has not established standards covering such products. (42 U.S.C.
6295(o)(3)) Any products that are non-ducted or that do not move air
through ductwork (e.g., draft inducer fans) would not meet the
definition of a furnace fan and are therefore out of scope of the
existing regulations.
In response to the November 2022 Preliminary Analysis, AHRI
commented that fans used in packaged units should be excluded from the
analysis as the energy use is already accounted for in the products'
seasonal energy efficiency

[[Page 69833]]

ratio (``SEER'') rating. AHRI stated that including these products in
the analysis of the overall quad savings would double count their
contribution because they are accounted for in prior rulemakings.
(AHRI, No. 23 at p. 4) Morrison commented that it does not see the need
for DOE to include fans used in packaged units within the furnace fans
rulemaking, as their energy use is already accounted for in SEER and
heating seasonal performance factor (``HSPF'') ratings and excluding
them from the rulemaking would prevent unnecessary repetition across
rulemaking documents. (Morrison, No. 27 at p. 2) In response, DOE notes
that for certain packaged units--WG-NC--there are existing standards at
10 CFR 430.32. In the July 2014 Final Rule, DOE assessed these products
and established energy conservation standards for them. 79 FR 38130,
38209. As discussed in section II.A of this document, DOE must
periodically review its already established energy conservation
standards for consumer furnace fans no later than 6 years from the
issuance of a final rule establishing or amending a standard for
consumer furnace fans. (42 U.S.C. 6295(m)) In accordance with these
provisions, DOE evaluated these products for this NOPD. DOE notes that
the base-case efficiency distribution of fans used in the analysis
includes presence of more-efficient furnace fans (e.g., with BPM
motors) in homes with higher-efficiency packaged units due to impacts
from previous rulemakings. Because the energy savings considered from
the furnace fan efficiency levels are measured relative to the base-
case efficiencies, the savings calculated in this analysis are over and
above those counted in previous rulemakings. Therefore, savings have
not been double counted.
The CA IOUs further commented that DOE has previously noted that
the provisions in 42 U.S.C. 6295(f)(4)(D) can encompass any
electrically-powered devices used in residential HVAC products,
including furnaces, and recommended that DOE investigate the savings
opportunity for regulating furnace fans in air handlers. (Id.) Finally,
the CA IOUs commented that many residential air handlers are offered
for sale with permanent split-capacitor-equipped fans and are likely
unable to meet the current rating for fan energy conservation standards
applicable to furnace fans. They added that manufacturers readily offer
air handlers with BPM motors and, therefore, a baseline technology
option incorporating a BPM motor is likely feasible for air handlers.
(Id. at pp. 5-6)
For the reasons discussed in the May 2022 TP NOPR, DOE is not
proposing to include fans used in other types of HVAC products,
including air-handlers, within the scope of coverage of appendix AA. 87
FR 29576, 29580. In the May 2022 TP NOPR, DOE tentatively concluded
that the electrical energy consumption of fans used in the
aforementioned types of HVAC products are accounted for by the seasonal
energy efficiency ratio 2 (``SEER2'') and heating seasonal performance
factor 2 (``HSPF2'') metrics measured by the test procedure for CACs
and heat pumps at appendix M1 to subpart B of part 430 (``appendix
M1''). 87 FR 29576, 29580. Therefore, DOE did not include air handlers
in the scope of the test procedure rulemaking and likewise did not
include them in this furnace fans rulemaking.
NEEA commented that it supported expanding coverage of furnace fans
to include NWO-NC products in the analysis because of the persistence
of this product class on the market and so the regulations would be
more inclusive of the entire market and prevent any unfair advantage
due to a gap in the regulations. NEEA also recommended that DOE include
mobile home non-weatherized, non-condensing furnace fans as a covered
product class, which, along with including NWO-NC, would encourage the
transition to BPM motors across the furnace fan market. (NEEA, No. 24
at pp. 1-2) NEEA recommended that DOE add additional classes, such as
non-weatherized, condensing oil (``NWO-C'') and weatherized, condensing
gas (``WG-C''), to cover the entire consumer furnace fans market. (Id.
at p. 2) Lennox commented that it finds the market impact of MH-NWO or
WG-C furnace fans to be extremely low with minimal energy saving
potential. (Lennox, No. 24 at p. 4)
DOE notes that, because it is not proposing amended standards at
this time, it is not proposing to assign new standards to any product
classes and will retain those classes for which standards currently
exist, as shown in Table II.1. For NWO-NC furnace fans, standards
currently exist and these products were included in this analysis. DOE
also analyzed MH-NWO-NC furnace fans for the purposes of making this
proposed determination. For other types of furnace fans, such as NWO-C
and WG-C furnace fans, DOE is only aware of a very small number of
products on the market. DOE has tentatively concluded that given the
nascent and developing state of these products it would be premature to
analyze proposed energy conservation standards at this time. Additional
information on the product classes analyzed for this NOPD is included
in section IV.A.4 of this document.
2. Technology Options
In the November 2022 Preliminary Analysis, DOE identified several
technology options that would be expected to improve the efficiency of
consumer furnace fans, as measured by the DOE test procedure.
Specifically, DOE identified the following technology options as having
the potential to improve the FER rating of consumer furnace fans (as
measured in accordance with appendix AA), and considered these
technology options further in the screening analysis:

<bullet> Housing design modifications
<bullet> Multi-stage heating components and controls \6\
---------------------------------------------------------------------------

\6\ Although multi-stage heating components and controls were
included in the list of technologies that can improve FER, DOE
stated that DOE has tentatively found that multi-stage heating
controls may not significantly improve furnace fan efficiency as
measured by FER. See chapter 3 and chapter 5 of the Preliminary
Analysis TSD.
---------------------------------------------------------------------------

<bullet> Airflow path design
<bullet> Constant-torque BPM (``CT-BPM'') and constant-airflow BPM
(``CA-BPM'') motors
<bullet> Inverter controls for permanent split capacitor (``PSC'')
motors
<bullet> Higher-efficiency fan blades

These technology options are described in detail in section 3.3.2
of the TSD accompanying the November 2022 Preliminary Analysis. In
response to the November 2022 Preliminary Analysis, DOE received
several comments related to these technology options. Several
commenters supported DOE's tentative decision to analyze CT-BPM and CA-
BPM motors together as a single design option because these motors
appear to have comparable efficiency as measured by DOE's test
procedure.
Lennox commented that CT-BPM and CA-BPM motors have similar
efficiencies. Lennox stated that while there can be minor differences
in the efficiency of BPM motors, they fall within a very narrow band
for potential improvement. Lennox commented that the primary
differences in performance are that a CT-BPM motor will result in
reduced airflow as static pressure increases, whereas a CA-BPM motor
will increase speed and power consumption to maintain airflow up to the
limit of the motor capability. Lennox commented that motor efficiency
as applied is more of a topographical map than a single point of
operation and that BPM motors maintain efficiency

[[Page 69834]]

performance over their operating range. (Lennox, No. 24 at p. 5)
Additionally, AHRI commented that constant torque and constant
airflow motors are similarly constructed but operate differently. AHRI
commented that, given consistent external static pressure and airflow,
AHRI assumes the two motor types would perform comparably within the
expected margins of error. (AHRI, No. 23 at pp. 4-5) Carrier also
commented that it agrees with DOE's assumption that CT-BPM and CA-BPM
motors have comparable efficiencies and stated that the motors use
similar construction despite being operated differently. Carrier
commented that if a furnace with a CT-BPM motor were compared to a
furnace with a similarly sized CA-BPM motor where both were operated at
the same external static pressure and airflow, these motor types would
consume the same amount of energy. (Carrier, No. 19 at p. 2) In
response to Lennox, AHRI, and Carrier, DOE notes that it continued to
analyze CT-BPM and CA-BPM motors together as a single design option for
this current analysis.
Beach recommended that DOE include efficiency testing and standards
in rudimentary equipment configuration descriptions. Beach recommended
that DOE outline where and how the fan motor is placed within the
equipment to avoid efficiency degradation at the spot where full
furnace air flow deposits airstream dust and material on the motor
windings. Beach commented that filter bypass, at a minimum, applies.
(Beach, No. 16 at p. 1)
In response to comments from Beach, DOE notes that its energy
conservation standards are in terms of FER, which is a performance-
based metric that captures the estimated annual electrical energy
consumption of the furnace fan normalized by: (a) the estimated total
number of annual fan operating hours and (b) the airflow in the maximum
airflow-control setting. DOE does not prescribe any design requirements
for furnace fans and therefore specifying the placement and
installation of the furnace fan within a furnace unit is out of the
scope of DOE's regulations.
In the November 2022 Preliminary Analysis TSD, DOE stated that it
tentatively did not consider two-stage and multi-stage technology
options as a design pathway for improving FER in the engineering
analysis based on manufacturer feedback, certification data, and
testing. DOE requested data or comment regarding the relationship
between staging and FER.
In response, AHRI commented that without performing a controlled
study, it is difficult to properly compare a single-stage product to a
two-stage product. AHRI commented that variables such as airflow design
and temperature rise can affect the comparison, adding that it would be
incorrect to generalize that one control type would have a distinct
advantage over another. (AHRI, No. 23 at p. 5) Carrier commented that
there is not adequate data to conclude whether single-stage and multi-
stage controls result in different FER ratings. Carrier commented that
comparison between the two control types is not straightforward due to
multiple design characteristics that make each furnace model unique.
Carrier stated that a controlled study is needed to eliminate variables
that are unique to each model, such as airflow design and temperature
rise selected. (Carrier, No. 19 at p. 2) Carrier also commented that it
generally has not found multi-staging to improve FER ratings and that
it does not believe one control type has a distinct advantage over the
other. (Id.)
Trane commented that the assumption that FER values for a multi-
stage furnace and a single-stage furnace are equal contradicts the 2014
TSD (EERE-2010-BT-STD-001-0111), which states that multi-staging was a
technology option that significantly differed from the single-stage
furnace. Trane commented that this difference affects the energy use
equations, as the FER was calculated with a multi-stage furnace and
energy use was calculated with a single-stage furnace. (Trane, No. 22
at p. 3)
Morrison questioned whether the lack of a benefit from multi-
staging is due to FER not appropriately capturing real energy use.
Morrison commented that, based on research presented in Canada's C823
efforts, average furnaces are oversized and rarely run at full
capacity, leading them to use more fan energy than necessary. Morrison
stated that part load operation would reduce the energy impact from
oversizing and hence reduce fan energy use, and stated it is unclear
why this option has been deemed not to be of benefit. (Morrison, No. 27
at p. 2)
DOE agrees with commenters that there are uncertainties related to
the effectiveness of two-stage or multi-stage in improving FER.
However, DOE has not received any additional data to support or
disprove any impacts on FER between single and multi-stage units.
Therefore, DOE has retained multi-stage heating components and controls
as a technology option in the current analysis but, as discussed in
section IV.B.1.a of this document, DOE did not consider two-stage or
multi-stage operation as a design pathway for improving FER in the
engineering analysis.
3. Impact From Other Rulemakings
Lennox commented that DOE needs to consider the total cumulative
regulatory burden for consumer furnaces, as there are multiple
concurrent DOE, EPA, and other regulatory actions undergoing updates.
(Lennox, No. 24 at pp. 8-9) Lennox stated that DOE's consideration of
cumulative regulatory burden has often been cursory and provided a list
of relevant regulations: ``2023 DOE Energy Conservation Standards
(``ECS'') change for central air conditioners; 2023 DOE Energy
Conservation Standard change for commercial air conditioners; 2023 DOE
ECS for commercial warm air furnaces (``CWAFs''); EPA phase-down to
lower GWP refrigerants to meet the American Innovation and
Manufacturing (``AIM'') Act objectives; DOE ECS Furnace Standards
rulemaking; National and Regional Cold Climate Heat Pump
Specifications; DOE ECS for Three-Phase, Below 65,000 Btu/h; DOE Test
Procedure for VRF Systems; EPA Energy Star 6.0+ for Residential HVAC;
and EPA Energy Star 4.0 for Light Commercial HVAC.'' (Id.) Lennox
stated that proposing amended consumer furnace fan standards would
contribute to the significant cumulative regulatory burden. (Id. at p.
9) Lennox commented that DOE needs to thoroughly consider the total
cumulative regulatory burden association with any consideration of
amended FER standards. Lennox commented that furnace manufacturers are
in the midst of unprecedented regulatory change regarding equipment
they manufacture. Lennox commented that these significant cumulative
regulatory burdens provide another reason why DOE should not add
additional burden by tightening consumer furnace fan regulations.
Lennox reiterated that the fans are components in furnaces already
regulated by DOE. (Id. at pp. 8-9)
AHRI asserted that DOE did not consider the impact of other ongoing
rulemakings (e.g., the notice of proposed rulemaking for consumer
furnaces). (AHRI, No. 23 at p. 1) Morrison stated that it supports the
comments submitted by AHRI advocating for the HVAC industry, as the
burden for furnace manufacturers to meet compliance will be high.
Morrison commented that the added burden of furnace fan ratings will
challenge imminent regulations and an industry overloaded with
regulations already underway, and that the schedule of regulations
impedes manufacturers from attempting new

[[Page 69835]]

product development and innovation. (Morrison, No. 27 at pp. 1-2)
DOE is not proposing to amend the energy conservation standards for
consumer furnace fans and therefore does not expect this rulemaking to
contribute to the cumulative regulatory burden of manufactures.
Lennox also commented that it opposes DOE expanding the regulatory
scope for electric motors into air-over motors, synchronous motors and
inverter-only motors, and expanded scope electric motors (ESEMs), in
particular when those motors are contained in already-regulated
heating, ventilation, air conditioning, and refrigeration (``HVACR'')
products. Lennox commented that DOE should continue to exempt air-over
and inverter-only motors (including AC and synchronous motors) from
component-level energy conservation standards regulation when these
motors are used in HVACR equipment already regulated at the systems
level. Lennox stated that DOE notes in the October 2022 Electric Motor
Test Procedure Final Rule (87 FR 63588) that an industry test procedure
DOE incorporated by reference is ``not applicable to air-over electric
motors that are synchronous electric motors and to air-over electric
motors that are inverter-only'' (10 CFR 431.25(I)). AHRI commented that
DOE should refer to the comments made by NEMA on the energy
conservation standards for Fans and Blowers on the issues surrounding
setting multiple standards for the same product under different
rulemakings in regards to the interaction between the furnace fan
rulemaking and the ESEMs rulemaking. (AHRI, No. 23 at p. 5)
In the ESEM rulemaking, DOE is considering including expanded scope
electric motors including certain permanent split capacitor (PSC)
motors that exceed 0.25 horsepower and are single-speed. DOE
understands that the vast majority of furnace fans use either
electrically commutated motors (i.e., ``ECMs'' which are also referred
to as BPM motors in this rulemaking) or are multiple-speed PSC motors,
both of which are out of the preliminary scope of the ESEM rulemaking.
Thus, furnace fans using BPM motors or multiple-speed PSC motors will
not be impacted by the ESEM rulemaking.\7\
---------------------------------------------------------------------------

\7\ See Docket EERE-2020-BT-STD-0007.
---------------------------------------------------------------------------

Screening Analysis
DOE uses the following five screening criteria to determine which
technology options are suitable for further consideration in an energy
conservation standards rulemaking:
(1) Technological feasibility. Technologies that are not
incorporated in commercial products or in commercially viable, existing
prototypes will not be considered further.
(2) Practicability to manufacture, install, and service. If it is
determined that mass production of a technology in commercial products
and reliable installation and servicing of the technology could not be
achieved on the scale necessary to serve the relevant market at the
time of the projected compliance date of the standard, then that
technology will not be considered further.
(3) Impacts on product utility. If a technology is determined to
have a significant adverse impact on the utility of the product to
subgroups of consumers, or result in the unavailability of any covered
product type with performance characteristics (including reliability),
features, sizes, capacities, and volumes that are substantially the
same as products generally available in the United States at the time,
it will not be considered further.
(4) Safety of technologies. If it is determined that a technology
would have significant adverse impacts on health or safety, it will not
be considered further.
(5) Unique-pathway proprietary technologies. If a technology has
proprietary protection and represents a unique pathway to achieving a
given efficiency level, it will not be considered further, due to the
potential for monopolistic concerns.

10 CFR part 430, subpart C, appendix A, sections 6(b)(3) and 7(b).

In summary, if DOE determines that a technology, or a combination
of technologies, fails to meet one or more of the listed five criteria,
it will be excluded from further consideration in the engineering
analysis.
a. Screened-Out Technologies
In the November 2022 Preliminary Analysis, DOE tentatively screened
out housing design modifications and changes to airflow path designs
from its analysis. In response, Lennox agreed with DOE's determination
to screen out housing designs and airflow paths that could impact the
thermal performance of the furnace and decrease consumer utility.
(Lennox, No. 24 at p. 5) Carrier also indicated agreement with DOE's
decision to screen out improved housing designs and airflow path
designs due to their impact on overall product size, stating that they
could adversely impact consumer utility and the practicality of making
replacement installations. Additionally, Carrier agreed there is no
quantitative data suggesting specific housing design changes provide
efficiency improvements in the same cabinet width. (Carrier, No. 19 at
p. 3)
The Joint Commenters commented that additional design options that
increase efficiency beyond a backward-inclined impeller are currently
available on the market. The Joint Commenters stated that airflow path
and fan housing improvements represent potential options for improving
furnace fan efficiency but noted that DOE screened out these design
modifications since they could impact the thermal performance of the
furnace. The Joint Commenters acknowledged this concern, but noted that
one of the models exceeding EL 1 is used in a condensing furnace with
an AFUE of 97 percent, suggesting manufacturers may be able to optimize
the furnace fan efficiency without negatively impacting the efficiency
of the furnace itself. The Joint Commenters recommended that DOE
continue investigating furnace fan efficiencies and how certain design
features on the current market permit furnace fan FER levels below
those analyzed in the TSD. (Joint Commenters, No. 20 at pp. 2-3)
As discussed in section IV.A.2 of this document, airflow path and
fan housing improvements can improve furnace fan efficiencies. However,
as discussed in chapter 4 of the November 2022 Preliminary Analysis
TSD, DOE does not have data that quantifies the impact of housing
design modifications on FER. Additionally, DOE has found that the
airflow path design can impact the performance of the larger furnace
system with possible changes to the furnace efficiency as measured in
AFUE. Though condensing furnaces can achieve lower FERs, DOE currently
lacks the data necessary to conclude that these options will not reduce
utility to consumers, and therefore has continued to screen out these
technologies for this analysis.
Several commenters also suggested that backward-inclined impeller
should be screened out of the current analysis. AHRI, Trane, Lennox,
and Daikin raised concerns about the technological feasibility of
backward-inclined impellers. AHRI commented that further analysis of
backward-inclined impellers is needed, stating that while backward-
inclined impellers can be considered a

[[Page 69836]]

mature technology in some products, it is nascent at best for consumer
furnaces. AHRI commented that the analysis performed in the TSD does
not capture the current state of this technology. (AHRI, No. 23 at pp.
2-3) Trane commented that the necessary backward-inclined impeller is
not available for purchase and is therefore unavailable to furnace
manufacturers for use in testing. (Trane, No. 22 at p. 2) Lennox
commented that backward-inclined impellers are nascent technology for
consumer furnaces and may not be practical for many installations.
Lennox commented that DOE's analysis does not accurately portray the
current state of this technology regarding residential furnace fans.
Lennox stated that current furnace designs are much more compact than
when DOE conducted research regarding backward-inclined impellers and
there is now less space to accommodate furnace fans. Lennox commented
that including backward-inclined impellers would require changes to the
housing design and airflow patterns, which DOE screened out in the TSD.
Lennox further commented that backward-inclined impellers are not a
one-size-fits-all application. Lennox stated that changing the airflow
design would require redesign and retesting on a model-by-model basis
to ensure proper operation, compliance with safety standards, and
product reliability. (Lennox, No. 24 at pp. 5-6) Daikin commented that
replacing a forward-curved impeller with a backward-curved impeller may
change the ESP of the unit and require that the unit use a larger
blower wheel. Daikin commented that increasing the blower wheel
diameter requires a change to the blower housing design, which was a
technology option DOE screened out in the preliminary analysis. Daikin
recommended that DOE evaluate the impact of backward-inclined impellers
on furnace ESP. (Daikin, No. 26 at pp. 21-22) Rheem requested to know
whether DOE had considered the impact of the backward-inclined impeller
system on other furnace components, such as the evaporator coil or
other accessories. (Rheem, No. 26 at p. 23) In contrast to these
comments, Carrier stated that it uses backward-inclined impellers in
non-weatherized gas furnaces that have 14-inch cabinets and AFUE
ratings of 95 percent or higher. (Carrier, No. 19 at p. 1)
Manufacturers also raised concerns about potential impacts on the
utility and safety of furnaces if backward-inclined impellers are used
as a technology option. Carrier commented that its experiences suggest
backward-inclined impellers significantly change the air profile
through the furnace and, to maintain safety and reliability, the
airflow must be redirected, adding that this can reduce the performance
improvement from the impeller change. Carrier further commented that in
applications where a larger impeller diameter cannot be accommodated,
the increased rotational speed increases the operation noise of the
furnace, adding that the noise generated from fan operation is an
important performance selection criterion to consumers. (Carrier, No.
19 at p. 3) Lennox commented that backward-inclined impellers present
many design challenges. Lennox noted that backward-inclined impellers
must have significantly higher tip speeds, which require either a
larger impeller diameter or higher rotational speed. However, Lennox
commented that the required speed increase is outside the normal range
of motors applied in furnace fans and would be likely to increase sound
levels and reduce consumer utility. (Lennox, No. 24 at p. 6)
In response to these concerns, DOE notes that, even if there are
only a limited number of commercially available product designs that
incorporate backward-inclined impellers, they are sufficient to
demonstrate technological feasibility as defined by EPCA. 10 CFR part
430, subpart C, appendix A, sections 6(b)(3)(i). Similarly, because
these technologies are used in commercialized designs, DOE has
determined that they can be implemented safely and reliably and with a
noise level that is acceptable to consumers. DOE agrees, however, that
there may be potential costs associated with potential redesign and
retesting to ensure safety and to ensure acceptable noise levels, and
this issue is discussed further in section IV.H of this document.
Therefore, for the current analysis, DOE tentatively screened out
housing design modifications and changes to airflow path designs from
its analysis but did not screen out backward-inclined impellers.
b. Remaining Technologies
After reviewing each technology, DOE did not screen out the
following technology options and considers them as design options in
the engineering analysis:

(1) Multi-stage heating components and controls
(2) High-efficiency fan motors (i.e., use of BPM fan motors for product
classes that currently use PSC motors)
(3) Inverter controls for PSC motors
(4) Higher-efficiency fan blades (backward-inclined impellers)

DOE determined that these technology options are technologically
feasible because they are being used or have previously been used in
commercially available products or working prototypes. DOE also finds
that all of the remaining technology options meet the other screening
criteria (i.e., practicable to manufacture, install, and service and do
not result in adverse impacts on consumer utility, product
availability, health, or safety).
4. Product Classes
In general, when evaluating and establishing energy conservation
standards, DOE divides the covered product into classes by (1) the type
of energy used, (2) the capacity of the product, or (3) any other
performance-related feature that affects energy efficiency and
justifies different standard levels, considering factors such as
consumer utility. (42 U.S.C. 6295(q))
DOE currently categorizes furnace fans into 10 product classes.
EPCA specifies criteria for product class separation which include: (1)
the type of energy consumed; (2) capacity; or (3) other performance-
related features that justify a higher or lower energy conservation
standard. 42 U.S.C. 6295(q) The 10 product classes currently
established by DOE are differentiated by performance related features,
including internal structure and application-specific design
differences, as presented in Table IV.1. For this NOPD, DOE maintained
these 10 classes, with the exception of a change to the mobile home
non-weatherized oil furnace fan (MH-NWO) class discussed hereinafter.

[[Page 69837]]

Table IV.1--Existing Furnace Fan Product Classes
------------------------------------------------------------------------
Product class
-------------------------------------------------------------------------
Non-weatherized, Non-condensing Gas Furnace Fan (NWG-NC).
Non-weatherized, Condensing Gas Furnace Fan (NWG-C).
Mobile Home Non-Weatherized, Non-condensing Gas Furnace Fan (MH-NWG-NC).
Mobile Home Non-Weatherized, Condensing Gas Furnace Fan (MH-NWG-C).
Mobile Home Electric Furnace/Modular Blower Fan (MH-EF/MB).
Non-Weatherized, Non-Condensing Oil Furnace Fan (NWO-NC).
Weatherized Non-Condensing Gas Furnace Fan (WG-NC).
Electric Furnace/Modular Blower Fan (EF/MB).
Mobile Home Weatherized Non-Condensing Gas Furnace Fan (MH-WG).*
Mobile Home Non-Weatherized Oil Furnace Fan (MH-NWO).*
------------------------------------------------------------------------
* DOE created the MH-NWO and MH-MG product classes in the July 2014
Final Rule, but these classes do not currently have energy
conservation standards.

Each product class title includes descriptors that indicate the
internal structure and application-specific performance related
features of its included products. As directed by EPCA, DOE must
specify a different standard level for a type or class of products that
has the same function or intended use if DOE determines that products
within such group: (A) consume a different kind of energy from that
consumed by other covered products within such type (or class); or (B)
have a capacity or other performance-related feature which other
products within such type (or class) do not have and such feature
justifies a higher or lower standard. (42 U.S.C. 6295(q)(1))
Weatherized and non-weatherized are descriptors that indicate whether
the HVAC product is installed outdoors or indoors, respectively. Design
constraints are different for products installed indoors compared to
outdoors, which impact furnace fan performance because furnace fan
energy consumption is dependent on clearances and airflow path
Weatherized products are packaged products that also include an
internal evaporator coil, while non-weatherized products are not
shipped with an evaporator coil but may be designed to be paired with
one. The presence of an evaporator coil increases internal static
pressure and impacts furnace fan performance and energy consumption.
Weatherization (i.e., the ability to be installed outdoors) is
therefore a performance-related feature as outlined by EPCA.
Condensing refers to the presence of a secondary, condensing heat
exchanger in addition to the primary combustion heat exchanger in
certain furnaces. The presence of a secondary heat exchanger improves
the AFUE of a consumer furnace but also increases internal static
pressure. As a result, DOE expects that furnace fans used in condensing
units will consume more electrical energy than similar, non-condensing
units, and therefore use with condensing technology constitutes a
performance-related feature for this product. Mobile home products meet
certain design requirements that allow them to be installed in mobile
homes. They require direct venting and are typically installed without
return air ducting. As a result, furnace fans used in mobile home
products consume a different amount of electric energy than furnace
fans installed in similar HVAC products that are designed for site-
built applications. Therefore, the ability to be installed in mobile
home applications is a performance-related feature under EPCA.
Descriptors like gas, oil, or electric indicate the type of fuel
that the HVAC product uses to produce heat, which determines the type
and geometry of the primary heat exchanger used in the HVAC product.
Each heat exchanger geometry could result in a unique internal static
pressure and therefore, have differing impacts on furnace fan
performance and energy consumption and are considered performance-
related features.
In the July 2014 Final Rule, DOE created product classes for MH-NWO
furnace fans and MH-WG furnace fans, but DOE did not analyze or
prescribe standards for either product class because of the lack of
available data for those product classes. 79 FR 38130, 38150. DOE is
not aware of any products that would be considered MH-WG furnace fans
at this time. However, DOE has become aware of a limited number of MH-
NWO furnace fans that have been introduced to the market. The MH-NWO
furnace fans that DOE identified are all used in non-condensing
furnaces, so DOE analyzed a subset of the previously established but
unanalyzed class--mobile home non-weatherized, oil, non-condensing (MH-
NWO-NC) furnace fans. DOE specifically considered MH-NWO-NC furnace
fans because, as with furnace fans used in gas-fired products, DOE
tentatively concluded that suitability for use with condensing
technology would be a performance related feature that would justify
further separating MH-NWO furnace fans into condensing and non-
condensing classes. Furnace fans used in oil-fired products that are
non-condensing as compared to those that are condensing would have
different performance due to likely differences in internal structure
of condensing products (if any were to be developed). As such,
suitability for use with condensing technology in a furnace fan is a
performance-related feature under EPCA. As DOE is not aware of any
condensing MH-NWO products, DOE did not analyze them for this NOPD
analysis and instead focused on MH-NWO-NC furnace fans. In summary, DOE
considered the product classes shown in the following list in its
analysis.

(1) Non-weatherized, Non-condensing Gas Furnace Fan (NWG-NC)
(2) Non-weatherized, Condensing Gas Furnace Fan (NWG-C)
(3) Mobile Home Non-weatherized, Non-condensing Gas Furnace Fan (MH-
NWG-NC)
(4) Mobile Home Non-weatherized, Condensing Gas Furnace (MH-NWG-C)
(5) Mobile Home Electric Furnace/Modular Blower Fan (MH-EF/MB)
(6) Non-weatherized, Non-condensing Oil Furnace Fan (NWO-NC)
(7) Weatherized Non-Condensing Gas Furnace Fan (WG-NC)
(8) Electric Furnace/Modular Blower (EF/MB)
(9) Mobile Home Non-Weatherized, Non-Condensing Oil Furnace Fan (MH-
NWO-NC)

B. Engineering Analysis

The purpose of the engineering analysis is to establish the
relationship between the efficiency and cost of consumer furnace fans.
There are two elements to consider in the engineering

[[Page 69838]]

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 products, DOE considers technologies
and design option combinations not eliminated by the screening
analysis. For each product class, DOE estimates the baseline cost, as
well as the incremental cost for the product at efficiency levels above
the baseline. The output of the engineering analysis is a set of
manufacturer production costs (``MPCs'') in cost-efficiency ``curves''
that are used in downstream analyses (i.e., the LCC and PBP analyses
and the NIA).
1. Efficiency Analysis
DOE typically uses one of two approaches to develop energy
efficiency levels for the engineering analysis: (1) relying on observed
efficiency levels in the market (i.e., the efficiency-level approach),
or (2) determining the incremental efficiency improvements associated
with incorporating specific design options to a baseline model (i.e.,
the design-option approach). Using the efficiency-level approach, the
efficiency levels established for the analysis are determined based on
the market distribution of existing products (in other words, based on
the range of efficiencies and efficiency level ``clusters'' that
already exist on the market). Using the design option approach, the
efficiency levels established for the analysis are determined through
detailed engineering calculations and/or computer simulations of the
efficiency improvements from implementing specific design options that
have been identified in the technology assessment. DOE may also rely on
a combination of these two approaches. For example, the efficiency-
level approach (based on actual products on the market) may be extended
using the design option approach to interpolate to define ``gap fill''
levels (to bridge large gaps between other identified efficiency
levels) and/or to extrapolate to the ``max-tech'' level (particularly
in cases where the ``max tech'' level exceeds the maximum efficiency
level currently available on the market).
Although FER data exists in DOE's Compliance Certification Database
(``CCD'') for furnace fans currently subject to efficiency standards,
DOE has determined through testing that for many furnace fan models,
the rated FER values may not be representative of the model's actual
performance. During confidential manufacturer interviews, several
manufacturers confirmed that they rate the FER of their furnace fan
products conservatively. Therefore, an efficiency level approach was
not possible because the FER ratings of products currently available
are largely not representative of their actual performance. Thus, DOE
chose a design option approach to identify efficiency levels for the
analysis in this proposed determination.
a. Baseline Efficiency Level
For each product 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 product class represents the characteristics of
a product 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. For
consumer furnace fans, the energy conservation standard sets a maximum
energy usage requirement and therefore a baseline furnace fan's rated
FER is just below or at the maximum FER threshold.
DOE used baseline units for comparison in several analyses,
including the engineering analysis, LCC analysis, PBP analysis, and
NIA. To determine energy savings that will result from an amended
energy conservation standard, DOE compared energy use at each of the
higher efficiency levels to the energy consumption of the baseline
unit. Similarly, to determine the changes in price to the consumer that
will result from an amended energy conservation standard, DOE compared
the prices of baseline units to the prices of units at each higher
efficiency level.
The identification of baseline units requires establishing the
baseline efficiency level. In cases where there is an existing
standard, DOE defines baseline units as units with efficiencies equal
to the current Federal energy conservation standards. For MH-NWO-NC
furnace fan product class, which does not currently have energy
conservation standards, DOE developed the baseline equation by
modifying the current energy conservation standards for the NWO-NC
product class to account for the lower ESP experienced by mobile home
units compared to other units. Specifically, DOE multiplied the y-
intercept (382) by 0.75, which was the conversion factor determined in
the analysis for the July 2014 Final Rule that was previously used to
calculate the MH-NWG-NC baseline based on the NWG-NC baseline.\8\
---------------------------------------------------------------------------

\8\ Chapter 5 of the TSD accompanying the July 2014 Final Rule
includes additional details about how this conversion factor was
calculated. See docket no. EERE-2010-BT-STD-0011.
---------------------------------------------------------------------------

Table IV.2 presents the maximum FER (i.e., the baseline level) for
each product class of consumer furnaces analyzed in this preliminary
analysis, as well as the typical characteristics of products at that
level.

Table IV.2--Baseline Efficiency Level FER and Associated Design Option for Each Product Class
----------------------------------------------------------------------------------------------------------------
Product class Maximum FER Design option
----------------------------------------------------------------------------------------------------------------
Non-Weatherized, Non-Condensing Gas 0.044 * QMax + 182..................... BPM Motor w/Forward Inclined
Furnace Fan. Impeller.
Non-Weatherized, Condensing Gas Furnace 0.044 * QMax + 195..................... BPM Motor w/Forward Inclined
Fan. Impeller.
Weatherized, Non-Condensing Gas Furnace 0.044 * QMax + 199..................... BPM Motor w/Forward Inclined
Fan. Impeller.
Non-Weatherized, Non-Condensing Oil 0.071 * QMax + 382..................... Improved PSC Motor w/Forward
Furnace Fan. Inclined Impeller.
Non-Weatherized Electric Furnace Fan/ 0.044 * QMax + 165..................... BPM Motor w/Forward Inclined
Modular Blower Fan. Impeller.
Manufactured Home, Non-Weatherized, Non- 0.071 * QMax + 222..................... Improved PSC Motor w/Forward
Condensing Gas Furnace Fan. Inclined Impeller.
Manufactured Home, Non-Weatherized, 0.071 * QMax + 240..................... Improved PSC Motor w/Forward
Condensing Gas Furnace Fan. Inclined Impeller.
Manufactured Home, Non-Weatherized 0.044 * QMax + 101..................... BPM Motor w/Forward Inclined
Electric Furnace Fan/Modular Blower Fan. Impeller.

[[Page 69839]]

Manufactured Home, Non-Weatherized Non- 0.071 * QMax + 287..................... Improved PSC Motor w/Forward
Condensing Oil Furnace Fan. Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Products in the NWG-NC, NWG-C, WG-NC, NWEF/NWMB, and MH-EF/MB
products classes are currently subject to the standards set in the July
2014 Final Rule, in which the efficiency levels adopted were understood
at that time to reflect models with CT-BPM motors and multi-stage
operation. Products in the NWO-NC and MH-NWG-NC product classes are
currently subject to the standards set in the July 2014 Final Rule in
which the efficiency level adopted were understood to correspond to the
performance associated with models including improved PSC motors and
single-stage operation. Baseline products in the MH-NWO-NC product
class were also found to correspond to performance associated with
models including improved PSC motors and single-stage operation, based
on DOE's market findings for mobile-home oil-fired units certified in
DOE's CCD for consumer furnaces.
Many furnaces include multi-stage or modulating heating controls.
However, based on current furnace fan market data as well as feedback
received during manufacturer interviews, it is unclear if these
features impact furnace fan efficiency as measured by FER (see section
IV.A.2). Therefore, DOE did not include the costs of multi-stage or
modulating heating controls in the baseline design (i.e., DOE's MPC
estimates reflect single-stage units). However, DOE did develop
separate cost values for multi-stage or modulating heating controls
that can be applied to the above costs to represent the addition of
multi-stage or modulating heating controls (see section IV.B.2.b of
this document). These additional cost values are used in DOE's LCC and
PBP analyses in order to represent typical furnace fan cost
distributions.
In addition, the baseline motor technology is either BPM or PSC,
depending on the product class. Manufacturers may choose a CABPM motor
instead of a CTBPM, despite its relatively higher cost, to add comfort
utility to their product. This additional comfort may be marketed as a
premium feature. Therefore, DOE included the cost of a CT-BPM motor in
the MPCs for furnace fans with BPM motors. DOE also developed cost
values to represent the cost increase for CA-BPM motors relative to CT-
BPM motors (see section IV.B.2.b of this document). These values were
applied in the LCC analysis to represent the distribution of BPM blower
motor technologies expected on the market because, although DOE is not
differentiating between CA-BPM motors and CT-BPM motors in terms of
furnace fan efficiency, manufacturers and consumers may consider CA-BPM
motors to be a premium feature that may offer comfort-related consumer
utility benefits.
In developing the cost-efficiency relationship, teardowns of
baseline units were used as a reference point for determining the cost-
efficiency relationship of units with lower (more efficient) FERs. DOE
compared the design features incorporated into products at the baseline
efficiency to the features of units with higher energy efficiencies in
order to determine the changes in manufacturing, installation, and
operating costs that occur as FER decreases.
In response to the November 2022 Preliminary Analysis, Morrison
commented that DOE's estimation of FER values is conservative, based on
data from OEMs and DOE, both of which indicate that analysis from 2014
is not representative of current furnace fan function and composition.
(Morrison, No. 27 at p. 2) Lennox commented that the use of BPM motors
is required to meet current furnace fan efficiency standards for most
consumer furnace fan categories and use of BPM motors is identified by
DOE as the current baseline. (Lennox, No. 24 at p. 8)
AHRI commented that baseline mobile home non-weatherized gas
furnace fan technology is not representative of the market. AHRI stated
that, in many cases, the current FER rating for mobile home non-
weatherized gas furnace fans cannot be met using a PSC motor, adding
that these products already incorporate a BPM motor to meet Federal
minimum standards. AHRI added that because mobile home non-weatherized
gas furnace fans already incorporate BPM motors to meet the current
levels, BPM motors will not be able to meet the FER minimums proposed
at EL 1. (AHRI, No. 23 at p. 3) AHRI recommended that DOE validate the
analysis performed for mobile home non-weatherized gas furnace fan to
ensure the baseline and subsequent ELs are correct. (Id.)
The Joint Commenters stated that current standards for both
weatherized and non-weatherized non-condensing gas furnace fans were
intended to effectively require use of efficient BPM motors, but stated
that DOE's analysis shows some non-condensing gas furnace fans
utilizing PSC motors can meet the current standards. The Joint
Commenters noted that one currently available furnace/furnace fan model
utilizes a PSC motor and is marketed as having a small footprint and
DOE should investigate how this model and others are able to meet the
current standards with presumably less efficient motors. (Joint
Commenters, No. 20 at p. 2)
The CA IOUs commented that they agree with DOE's decision to use
the costs associated with constant-torque BPM and single-stage controls
for its cost analysis for EL 1, adding that DOE has found several
furnace fans on the market that meet EL 1. (CA IOUs, No. 21 at p. 2)
The CA IOUs also noted that a 2017 California Codes and Standards
Enhancement report evaluated air handlers sold with heat pumps and
confirmed that while cabinet and blower design can affect internal
resistance to airflow, a PSC motor can adversely affect fan efficacy.
(Id. at p. 5)
In response, DOE notes that it has developed baseline efficiency
levels that are representative of the baseline technologies used in the
current furnace fan market. While the FER ratings reported in CCMS are
generally likely to be conservative estimates, DOE has conducted
testing to understand the impacts of the technology options identified
in section IV.A.2 on furnace fan efficiency, and has developed
efficiency levels that reflect those impacts. DOE agrees with
commenters that the use of BPM motors is necessary to meet the baseline
for some product classes, as outlined in Table IV.2, but notes that
some product classes can meet the baseline efficiency level using an
improved PSC motor. In response to AHRI's comments, although DOE
recognizes that many mobile home

[[Page 69840]]

furnaces use BPM motors, DOE is aware of mobile home furnaces on the
market that use an improved PSC motor and meet the current FER
standards. DOE thus concludes that FER standards can be achieved using
this technology and has maintained improved PSC motors as a part of the
baseline design option for mobile home furnaces. Conversely, DOE's
market data shows that no non-weatherized gas furnaces currently on the
market use PSC motors; DOE therefore concludes that a BPM motor
continues to be an appropriate baseline motor design for this class.
b. Intermediate Efficiency Levels
DOE analyzed intermediate efficiency levels for NWO-NC, MH-NWG-NC,
MH-NWG-C, and MH-NWO-NC classes of consumer furnace fans. As discussed
in section IV.B.1.c, DOE did not identify any efficiency levels between
baseline and max-tech for the NWG-NC, NWG-C, WG-NC, NWEF/NWMB, and MH-
EF/MB classes. The intermediate efficiency levels identified are
representative of efficiency levels where major technological changes
occur (i.e., replacing PSC motors with BPM motors). As discussed in
section IV.B.1.a of this document, DOE has tentatively found that CT-
BPM motors and CA-BPM motors have comparable impacts on FER ratings,
and DOE has therefore only analyzed a single efficiency level
reflecting the implementation of BPM motors. Additionally, DOE has
tentatively used the assumption of a 12-percent reduction in FER for
improved PSC motors and a 46-percent reduction in FER for models with a
CT-BPM and multi-staging from the baseline used in the 2014 Final Rule
(79 FR 38130, 38159) to calculate a 39-percent reduction in FER from
improved PSC (the current baseline) to CT-BPM with multi-staging. The
39-percent reduction in FER is implemented into the current analysis to
represent the reduction in FER from improved PSC to a model with a CT-
BPM (regardless of staging) because DOE has tentatively decided not to
include staging as a technology option that improves FER.
In response to the November 2022 Preliminary Analysis, Lennox
commented that the efficiency levels and design options associated with
the use of forward curved impellers and BPM motors are reasonable.
(Lennox, No. 24 at p. 7)
The Joint Commenters commented that models with lower FERs than EL
1 are available in each of the major furnace fan product classes. The
Joint Commenters commented that, based on results in the CCD, both
condensing and non-condensing non-weatherized furnace fans with
efficiencies exceeding EL 1 are available across a broad range of
airflows. The Joint Commenters stated that, as DOE acknowledged in the
TSD, many manufacturers rate their furnace fans conservatively, which
suggests the number of higher-efficiency furnace fans available on the
market is understated. (Joint Commenters, No. 20 at pp. 1-2)
Additionally, the Joint Commenters encouraged DOE to analyze an EL
associated with improved BPM motor efficiency. The Joint Commenters
stated that a range of BPM motor efficiencies currently exist on the
market but added that DOE did not analyze improved motor efficiency as
a potential design option. The Joint Commenters encouraged DOE to
gather additional information from motor manufacturers to characterize
the FER reductions achievable with the most efficient BPM motors
available, and to analyze an EL associated with these higher efficiency
BPM motors for the next stage of the rulemaking. (Id. at p. 3)
DOE is not aware of any data showing the relationship between
improved motor efficiency and FER ratings. DOE welcomes data exploring
this relationship and may include efficiency levels corresponding to
the use of more efficient BPM motors in a future analysis but did not
include this additional efficiency level in the current analysis due to
the lack of data.
c. Maximum Technology Efficiency Levels
As part of DOE's analysis, the maximum available efficiency level
is the highest efficiency unit currently available on the market. DOE
also defines a ``max-tech'' efficiency level to represent the maximum
possible efficiency for a given product. DOE identified the max-tech
design for all consumer furnace fans product types as incorporating a
BPM motor with a backward-inclined impeller.
BPM motors are described in sections IV.B.1.a and IV.B.1.b of this
chapter. For furnace fan models that use PSC motors, BPM motors can
offer an improvement in efficiency and reduce FER. Backward-inclined
impellers, in comparison to forward-inclined impellers used in the
majority of furnace fans on the market, have been found to have a
higher efficiency under certain operating conditions. In chapter 5 of
the TSD accompanying the November 2022 Preliminary Analysis, DOE
explained that it has tentatively used the same assumptions about the
percent reduction in FER associated with implementing backward-inclined
impellers as in the July 2014 Final Rule (i.e., a 10-percent reduction
in FER compared to models that include forward-inclined impellers). 79
FR 38130, 38159.
In response to the November 2022 Preliminary Analysis, several
commenters raised concerns about the assumption that a backward-
inclined impellers will reduce FER by 10 percent. Several commenters
suggested that the impact of backward-inclined impellers on FER may
vary by application. Carrier commented that DOE correctly concluded in
the TSD that the efficiency improvement of a backward-inclined impeller
is not uniform across the entire range of operation. Carrier stated
that this lack of uniformity can require limiting the operating range,
which reduces the furnace utility, or leads to unrealized efficiency
improvements in application. Carrier stated that it believes backward-
inclined impellers are not a technologically feasible design option in
some models because they do not improve efficiency and in other models
they reduce furnace utility. Carrier stated that its non-weatherized
95-percent-plus AFUE 14-inch-width gas furnaces use backward-inclined
impellers to meet the current FER standards. (Carrier, No. 19 at pp. 3-
4) Carrier commented that it completed extensive research and evaluated
the impact of this technology in many furnace variations and suggested
that DOE's technology assessment does not fully account for the design
challenges of using backward-inclined impellers in consumer furnaces.
Carrier commented that the improvement in fan efficiency is not uniform
across model sizes within a product family due to design changes needed
to address the safety and reliability \9\ of the furnaces. Carrier
requested that DOE continue its study of backward-inclined impeller
technology to better understand the efficiency improvement variation
across product sizes before concluding a uniform reduction in FER for a
product class. Carrier also stated that because its models that
incorporate backward-inclined impeller use the maximum technology
design options, any reduction in the FER limit would eliminate them
from the market. (Id. at pp. 1-3)
---------------------------------------------------------------------------

\9\ Carrier's comments related to safety and reliability
concerns are discussed in section IV.A.4.a of this document.
---------------------------------------------------------------------------

AHRI commented that it is aware of products on the market which use
proprietary backward-inclined impeller designs that are not capable of
meeting the FER that DOE has associated with

[[Page 69841]]

that design option. AHRI further commented that these products are some
of the highest-efficiency products on the market and stated that if the
FER requirement is moved to a max-tech level, both furnace fan
availability and high-efficiency furnace availability will be affected.
(AHRI, No. 23 at pp. 5-6)
The CA IOUs requested that DOE conduct additional research on
backward-inclined fan performance to ensure the projected energy
savings. The CA IOUs further requested that DOE collect current data on
the performance of backward-inclined impellers in furnaces to compare
with forward-curved fans available in 2023. The CA IOUs commented that
DOE's calculations appeared to be based on research that may not
reflect the current performance of forward-curved fans and instead
overstates the performance of backward-inclined fans on the market. The
CA IOUs commented that DOE's findings of 10-percent energy savings
expected from backward-inclined fans were first presented in the 2014
TSD and were based on 2003 GE testing of a single backward-inclined
prototype against a single forward curved fan. The CA IOUs commented
that a follow-up LBNL report found that the construction of the
forward-curved fan tested in 2003 was substandard and contained large
gaps between the impeller and housing and misalignment between the
impeller and inlet. The CA IOUs pointed out that furnace fans in 2003
had no performance requirements and that with the advent of furnace fan
regulation, forward-curved fan design has improved while backward-
inclined fans currently available are not noticeably better than the
prototype tested in 2003. The CA IOUs presented data showing the
performance of one manufacturer's forward-curved and backward-inclined
fans and commented that additional research is needed to confirm the
efficiency difference before DOE considers using backward-inclined
fans. (CA IOUs, No. 21 at pp. 2-5)
Morrison stated that the GE fan referenced by DOE (as the basis of
the backward inclined impeller analysis) was used in LBNL research and
had limited benefit when compared to a forward-curved fan. Furthermore,
Morrison commented that more information was needed regarding claims in
the TSD that the use of EBM fans resulted in a 15-30-percent
improvement. Morrison stated that DOE used an estimated 10-percent FER
improvement from the 2014 rulemaking, but that would be relative to
older designs made prior to changes seen in furnace fans since 2019.
Morrison stated that consumer furnace fans have been improved since
then to improve energy use. (Morrison, No. 27 at p. 2) No commenters
submitted data supporting an alternative FER reduction value to
associate with backward-inclined impellers. Therefore, DOE continued to
rely on the best data available, which is what DOE used to arrive at
the assumption that backward-inclined impellers uniformly reduce the
FER of consumer furnace fans by a 10-percent reduction in the July 2014
Final Rule. With respect to Morrison's comments that the furnace fan
designs have changed since 2014, DOE notes that the estimate of a 10-
percent reduction is not relative to the baseline design, but instead
is relative to an equivalent furnace fan with a forward curved impeller
and thus still applies. In other words, in the July 2014 Final Rule,
DOE estimated that implementing a backward-inclined impeller in place
of a forward-inclined impeller would reduce FER by 10 percent in a
furnace fan with a constant-airflow BPM motor and multi-staging; it was
not relative to a baseline furnace with a PSC motor and single-stage
operation. 79 FR 38130, 38159. (As previously discussed, for this
analysis DOE did not find evidence of significant differentiation in
FER among multi-stage models as compared to single-stage models, or
between constant-airflow and constant-torque BPM motors.) However, the
concerns and uncertainties raised by commenters in the above paragraphs
contribute to DOE's tentative decision not to adopt standards at max-
tech levels for furnace fans at this time. For additional discussion
regarding backward-inclined impellers, see section IV.H of this
document.
In response to DOE's consideration of backward-inclined impellers
at the max-tech level in the November 2022 Preliminary Analysis,
commenters discussed a number of concerns with implementing the
technology.
AHRI commented that there is no one-size-fits-all design for
incorporating backward-inclined impellers into current products. AHRI
stated that changes in the airflow design will require redesign and
retesting on a model-by-model basis to ensure both proper operation and
compliance with safety standards. (AHRI, No. 23 at p. 5) AHRI commented
that the issues associated with moving from a forward-inclined impeller
to a backward-inclined impeller will require safety testing and
redesign. AHRI further commented that these additional costs are not
accounted for in the analysis. (Id. at p. 3)
Trane commented that, based on its research, a backward-inclined
impeller is not compatible with current furnace dimensions, which are
not large enough to accommodate a backward-inclined impeller. Trane
added that it cannot be assumed that furnace design changes will have
no impact on energy use and equipment utility when a backward-inclined
impeller is used in the existing housing. Furthermore, Trane commented
that, based on its research, the issues of the inlet cone design and
clearances to the moving impeller remain a concern and require
attention. (Trane, No. 22 at p. 2)
Trane commented that adopting EL 1 would require replacing the
current forward-inclined impeller with a backward-inclined impeller.
Trane added that its research showed a 7-year development cycle for the
blower system technology needed to adopt EL 1. Trane commented that
this same research surfaced concerns with the ability to manufacture a
high-speed (~1800 RPM max) blower wheel with close tolerances with the
inlet cones, and significant leakage of high-pressure air from the
exhaust portion of the housing back into the low-pressure input region
if typical 0.25-in gaps are implemented. Trane commented that
improvements from only retrofitting the impeller were less than 10
percent unless blower housing modifications were made. Trane commented
that its determination regarding the impellers was based on a study
completed more than 20 years ago, ``Final Report for the Variable Speed
Integrated Intelligent HVAC Blower, Final Report for BP-2'' (June 1,
2003). (Trane, No. 22 at p. 2)
Trane acknowledged that DOE's findings were based on the EBM-Papst
furnace model, which has a backward-inclined impeller blower system.
Trane commented that the EBM-Papst system is not an impeller change,
but a different blower system that produces a different air flow
pattern from the forward-inclined impeller and is thus not able to be
tested according to the same standards as a furnace fan with a forward-
inclined impeller. Trane commented that for all manufacturers to adopt
this system would require all safety, performance, and AFUE testing to
be performed in order to put it into production, and furthermore, due
to its need for an inlet orifice, this system limits the furnace's
return air location to a single location (i.e., left side, right side,
or bottom). Trane added that higher air flow furnaces often need more
than a single side return to perform properly for CFM and watts, and
therefore adopting the EBM-Papst approach would not be possible for
many furnace fan manufacturers. Trane commented that, for the reasons
stated

[[Page 69842]]

above and because it would reduce the utility of the furnace, the EBM-
Papst system is unsuitable as a basis for comparison for adopting EL 1
among furnace fan manufacturers. (Id.) Furthermore, Trane commented
that adapting all furnace fans to accommodate the EBM-Papst system
would reduce the utility of the furnace and increase the installation
time needed to move components to reach the return air location
required by the system. Trane commented that the EBM-Papst system
should have been analyzed as a separate EL level. (Trane, No. 22 at pp.
2-3)
Trane commented that testing would be required ahead of introducing
the impeller change in order to determine the effects this difference
would have on heat exchanger temperatures, furnace efficiency, and
safety limit operation. Trane commented that according to DOE, housing
design modifications were eliminated from consideration due to the
resulting reduction in utility that such a change produces. Trane
commented that the same logic should apply to an impeller change that
creates a substantially different discharge velocity distribution.
(Trane, No. 22 at p. 3)
Lennox commented that the application of backward-inclined
impellers would require changes in the housing design and airflow
patterns that DOE has already screened out in the TSD. Lennox further
commented that changes in the airflow design will require redesign and
retesting on a model-by-model basis to ensure proper operation,
compliance with safety standards, and product reliability. (Lennox, No.
24 at p. 7)
AHRI commented that backward-inclined impellers require a larger
diameter than the forward-inclined impellers they are intended to
replace, stating that backward-inclined impellers will not fit in the
cabinet of a fan with a forward-inclined impeller. They further
commented that most all models will have to be redesigned to
accommodate the larger impeller, adding that it will lead to housing
design and airflow path modifications. AHRI stated DOE has acknowledged
that modifications of housing design and airflow path have an adverse
impact on furnace efficiency. (AHRI, No. 23 at p. 3)
AHRI commented that furnace cabinets are limited in size due to the
dimensions of the installation space. AHRI stated that smaller-sized
furnaces are at a disadvantage when it comes to meeting the required
FER level because of the relationship between the furnace input level
and the width of the furnace. AHRI commented that a change to the
efficiency level to include backward-inclined impellers, coupled with
the proposed future change to the minimum AFUE, would likely eliminate
the smallest cabinet sizes from the marketplace without replacement
furnace options or with reduced choices for consumers in cases where
the smallest size model is required. (AHRI, No. 23 at p. 6)
The CA IOUs suggested that DOE refrain from implementing energy
conservation standards that would require the use of backward inclined
fans, as the CA IOUs could not identify furnaces incorporating
backward-inclined fans available for purchase. (CA IOUs, No. 21 at p.
2)
In response, as discussed previously and as several commenters
acknowledge, DOE is aware of backward-inclined impellers being used in
other sectors of the HVAC industry and also in a small number of
consumer furnace fan models available today. Therefore, DOE has found
this design option to be technologically feasible. DOE identified and
examined the models that currently use backward inclined impellers and
did not identify any significant differences in cabinet dimensions,
overall construction, or any indication of installation constraints as
compared to similar models using a forward-curved impeller. As a
result, DOE maintained backward-inclined impellers as a design option
at max-tech for this analysis. However, given the limited number of
consumer furnace fan models that this technology is currently used in,
DOE recognizes that there are some uncertainties with applying it to
the entire consumer furnace fans market and across the entire range of
capacities, as pointed out by several commenters. As discussed in
section V.C of this document, DOE is proposing not to amend standards
and therefore use of a backward inclined impeller would not be
required. While this decision is primarily based on the cost
effectiveness of this design option at this time, DOE has also
considered some analytical uncertainties, as discussed in sections IV.H
and V.C of this document.
d. Summary of Efficiency Levels Analyzed
The efficiency levels and associated technologies analyzed for each
class of consumer furnace fan are shown in Table IV.3 through Table
IV.11.

Table IV.3--Efficiency Levels and Technologies Used at Each Efficiency Level for NWG-NC Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.044 * QMax + 182....... BPM Motor w/Forward- N/A
Curved Impeller.
1--Max-tech............................ 0.04 * QMax + 164........ BPM Motor w/Backward- 10
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Table IV.4--Efficiency Levels and Technologies Used at Each Efficiency Level for NWG-C Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.044 * QMax + 195....... BPM Motor w/Forward- N/A
Curved Impeller.
1--Max-tech............................ 0.04 * QMax + 176........ BPM Motor w/Backward- 10
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

[[Page 69843]]

Table IV.5--Efficiency Levels and Technologies Used at Each Efficiency Level for WG-NC Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.044 * QMax + 199....... BPM Motor w/Forward- N/A
Curved Impeller.
1--Max-tech............................ 0.04 * QMax + 179........ BPM Motor w/Backward- 10
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Table IV.6--Efficiency Levels and Technologies Used at Each Efficiency Level for NWEF/NWMB Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.044 * QMax + 165....... BPM Motor w/Forward- N/A
Curved Impeller.
1--Max-tech............................ 0.04 * QMax + 149........ BPM Motor w/Backward- 10
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Table IV.7--Efficiency Levels and Technologies Used at Each Efficiency Level for MH-EF/MB Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.044 * QMax + 101....... BPM Motor w/Forward- N/A
Curved Impeller.
1--Max--Tech........................... 0.04 * QMax + 91......... BPM Motor w/Backward- 10
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Table IV.8--Efficiency Levels and Technologies Used at Each Efficiency Level for MH-NWG-NC Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.071 * QMax + 222....... Improved PSC Motor....... N/A
1...................................... 0.044 * QMax + 137....... BPM Motor w/Forward- 39
Curved Impeller.
2--Max-tech............................ 0.04 * QMax + 123........ BPM Motor w/Backward- 45
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Table IV.9--Efficiency Levels and Technologies Used at Each Efficiency Level for MH-NWG-C Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.071 * QMax + 240....... Improved PSC Motor....... N/A
1...................................... 0.044 * QMax + 148....... BPM Motor w/Forward- 39
Curved Impeller.
2--Max-tech............................ 0.04 * QMax + 133........ BPM Motor w/Backward- 45
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Table IV.10--Efficiency Levels and Technologies Used at Each Efficiency Level for NWO-NC Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.071 * QMax + 382....... Improved PSC Motor....... N/A
1...................................... 0.044 * QMax + 236....... BPM Motor w/Forward - 39
Curved Impeller.
2--Max-tech............................ 0.04 * QMax + 212........ BPM Motor w/Backward- 45
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

Table IV.11--Efficiency Levels and Technologies Used at Each Efficiency Level MH-NWO-NC Fans
----------------------------------------------------------------------------------------------------------------
Description of Percent reduction
EL FER equation technologies typically in FER from
incorporated baseline
----------------------------------------------------------------------------------------------------------------
0--Baseline............................ 0.071 * QMax + 287....... Improved PSC Motor....... N/A
1...................................... 0.044 * QMax + 176....... BPM Motor w/Forward - 39
Curved Impeller.

[[Page 69844]]

2--Max-tech............................ 0.04 * QMax + 158........ BPM Motor w/Backward- 45
Inclined Impeller.
----------------------------------------------------------------------------------------------------------------

2. Cost Analysis
The cost analysis portion of the Engineering Analysis is conducted
using one or a combination of cost approaches. The selection of cost
approach depends on a suite of factors, including the availability and
reliability of public information, characteristics of the regulated
product and the availability and timeliness of purchasing the consumer
furnace fans on the market. The cost approaches are summarized as
follows:
<bullet> Physical teardowns: Under this approach, DOE physically
dismantles a commercially available product, component-by-component, to
develop a detailed bill of materials for the product.
<bullet> Catalog teardowns: In lieu of physically deconstructing a
product, DOE identifies each component using parts diagrams (available
from manufacturer websites or appliance repair websites, for example)
to develop the bill of materials for the product.
<bullet> Price surveys: If neither a physical nor catalog teardown
is feasible (for example, for tightly integrated products such as
fluorescent lamps, which are infeasible to disassemble and for which
parts diagrams are unavailable) or cost-prohibitive and otherwise
impractical (e.g., large commercial boilers), DOE conducts price
surveys using publicly available pricing data published on major online
retailer websites and/or by soliciting prices from distributors and
other commercial channels.
In the present case, DOE conducted its cost analysis using a
combination of physical and catalog teardowns to assess how
manufacturing costs change with increased product efficiency. DOE
estimated the MPC associated with each efficiency level to characterize
the cost-efficiency relationship of improving consumer furnace fan
performance. The MPC estimates are not for the entire HVAC product.
Because consumer furnace fans are a component of the HVAC product in
which they are integrated, the MPC estimates include costs only for the
components of the HVAC product that impact FER.
Products were selected for physical teardown analysis that have
characteristics of typical products on the market at a representative
input capacity of 80,000 Btu/h for the NWG-NC, NWG-C, WG-NC, NWEF/NWMB,
MH-NWG-NC, MH-NWG-C, MH-EF/MB, and MH-WG product classes and 105,000
Btu/h for the NWO-NC and MH-NWO product classes (determined based on
market data and discussions with manufacturers). Selections spanned a
range of FER efficiency levels and designs and included most
manufacturers. The resulting bill of materials provides the basis for
the manufacturer production cost (``MPC'') estimates.
To account for manufacturers' non-production costs and profit
margin, DOE applies a multiplier (the manufacturer markup) to the MPC.
The resulting manufacturer selling price (``MSP'') is the price at
which the manufacturer distributes a unit into commerce. DOE developed
an average manufacturer markup by examining the annual Securities and
Exchange Commission (``SEC'') 10-K reports filed by publicly-traded
manufacturers primarily engaged in HVAC manufacturing and whose
combined product range includes consumer furnace fans. DOE refined its
understanding of manufacturer mark-ups by using information obtained
during manufacturer interviews. The manufacturer mark-ups were used to
convert the MPCs into MSPs. Further information on this analytical
methodology is presented in the following subsections.
a. Teardown Analysis
To assemble bills of materials (``BOMs'') and to calculate
manufacturing costs for the different components in consumer furnace
fans, multiple units were disassembled into their base components, and
DOE estimated the materials, processes, and labor required to
manufacture each individual component, a process referred to as a
``physical teardown.'' Using the data gathered from the physical
teardowns, each component was characterized according to its weight,
dimensions, material, quantity, and the manufacturing processes used to
fabricate and assemble it.
For supplementary catalog teardowns, product data were gathered,
such as dimensions, weight, and design features from publicly available
information, such as manufacturer catalogs. Such ``virtual teardowns''
allowed DOE to estimate the major physical differences between a
product that was physically disassembled and a similar product that was
not. For this NOPD, data from a total of 61 physical and virtual
teardowns of consumer furnace fans were used to calculate industry MPCs
in the engineering analysis.
The manufacturers of units chosen for teardowns have large market
shares in the particular product classes for which their teardown units
are categorized. Whenever possible, DOE examined multiple models from a
given manufacturer that capture different design options and used them
as direct points of comparison. DOE examined products with PSC, CT-BPM,
and CA-BPM indoor blower motors, as well as products using single-
stage, two-stage, and modulating combustion systems. As further
discussed in section IV.B.2.b of this document, cost values were
developed for some of these technologies to estimate the manufacturing
cost of changing designs from one technology to another (i.e., using a
CA-BPM instead of a CT-BPM, or two-stage combustion instead of single-
stage combustion).
b. Cost Estimation Method
The costs of individual models are estimated using the content of
the BOMs (i.e., relating to materials, fabrication, labor, and all
other aspects that make up a production facility) to generate MPCs. The
resulting MPCs include costs such as overhead and depreciation, in
addition to materials and labor costs. DOE collected information on
labor rates, tooling costs, raw material prices, and other factors to
use as inputs into the cost estimates. For purchased parts, DOE
estimates the purchase price based on volume-variable price quotations
and detailed discussions with manufacturers and component suppliers.
Furnace fans are a component of HVAC products that include other
products not associated with the cost and/or efficiency of the furnace
fan. Therefore, DOE focused its engineering analysis on the components
that comprise the furnace fan assembly, including:

[[Page 69845]]

<bullet> Fan motor and integrated controls (as applicable);
<bullet> HVAC product control board;
<bullet> Impeller;
<bullet> Single-staging or multi-staging components and controls;
<bullet> Fan housing; and
<bullet> Components used to direct or guide airflow.
For parts fabricated in-house, the prices of the underlying ``raw''
metals (e.g., tube, sheet metal) are estimated on the basis of 5-year
averages to smooth out spikes in demand. For purchased parts, DOE
estimated the purchase prices paid to the OEMs of these parts, based on
discussions with manufacturers during confidential interviews. Whenever
possible, DOE obtained price quotes directly from the component
suppliers used by furnace fan manufacturers whose products were
examined in the engineering analysis. DOE determined that the
components in Table IV.12 are generally purchased from outside
suppliers.

Table IV.12--Purchased Furnace Fan Components
------------------------------------------------------------------------
Purchased sub-assemblies or
Assembly components
------------------------------------------------------------------------
Fan Assembly..................... Fan motor.
Motor capacitor (when applicable).
Impeller.
Controls......................... PCB.
Multi-Staging Components (when
applicable).
------------------------------------------------------------------------

Raw materials, such as plastic resins and insulation materials, are
estimated on a current-market basis. The costs of raw materials are
determined based on manufacturer interviews, quotes from suppliers, and
secondary research. Past results are updated periodically and/or
inflated to present-day prices using indices from resources such as
MEPS Intl.,\10\ PolymerUpdate,\11\ the U.S. geologic survey
(``USGS''),\12\ and the Bureau of Labor Statistics (``BLS'').\13\ To
smooth out spikes in demand, these prices are estimated on the basis of
5-year averages spanning from 2018 through 2022. Other ``raw''
materials such as plastic resins, insulation materials, etc. are
estimated on a current-market basis. For non-metal raw material prices,
DOE used prices based on current market data, rather than a 5-year
average, because non-metal raw materials typically do not experience
the same level of price volatility as metal raw materials.
---------------------------------------------------------------------------

\10\ For more information on MEPS Intl, please visit
<a href="http://www.mepsinternational.com/gb/en">www.mepsinternational.com/gb/en</a> (Last accessed March 21, 2023).
\11\ For more information on PolymerUpdate, please visit
<a href="http://www.polymerupdate.com">www.polymerupdate.com</a> (Last accessed March 21, 2023).
\12\ For more information on USGS metal price statistics, please
visit <a href="http://www.usgs.gov/centers/national-minerals-information-center/commodity-statistics-and-information">www.usgs.gov/centers/national-minerals-information-center/commodity-statistics-and-information</a> (Last accessed March 21, 2023).
\13\ For more information on the BLS producer price indices,
please visit <a href="http://www.bls.gov/ppi/">www.bls.gov/ppi/</a> (Last accessed March 21, 2023).
---------------------------------------------------------------------------

Certain factory parameters, such as fabrication rates, labor rates,
and wages, also affect the cost of each unit produced. DOE factory
parameter assumptions were based on internal expertise and manufacturer
feedback. Table IV.13 lists the factory parameter assumptions used in
the cost model for both high-volume and low-volume manufacturers. For
the engineering analysis, these factory parameters, including
production volume, are the same at every efficiency level. The
production volume used at each efficiency level corresponds with the
average production volume, per manufacturer. These assumptions are
generalized to represent typical production and are not intended to
model a specific factory. For the NWG-NC, NWG-C, WG-NC, NWEF/NWMB, MH-
NWG-NC, MH-NWG-C, and MH-EF/MB product classes, high production volume
parameters were assumed due to these classes having generally high
production volumes or using enough of the same major components as
other high production volume classes. For NWO-NC and MH-NWO product
classes, low production parameters were assumed.

Table IV.13--Factory Parameter Assumptions
------------------------------------------------------------------------
High-volume furnace Low-volume furnace
Parameter fan estimate fan estimate
------------------------------------------------------------------------
Actual Annual Production 1,250,000........... 5,000.
Volume (units/year).
Purchased Parts Volume...... 500,000 units/year.. 5,000 units/year.
Work Days Per Year (days)... 250................. 250.
Assembly Shifts Per Day 2................... 1.
(shifts).
Fabrication Shifts Per Day 2................... 2.
(shifts).
Fabrication Labor Wages ($/ 16.................. 16.
h).
Assembly Labor Wages ($/h).. 16.................. 16.
Length of Shift (hrs)....... 8................... 8.
Average Equipment 10%................. 10%.
Installation Cost (% of
purchase price).
Fringe Benefits Ratio....... 50%................. 50%.
Indirect to Direct Labor 33%................. 33%.
Ratio.
Average Scrap Recovery Value 30%................. 30%.
Worker Downtime............. 10%................. 10%.
Building Life (in years).... 25.................. 25.
Burdened Assembly Labor Wage 24.................. 24.
($/h).
Burdened Fabrication Labor 24.................. 24.
Wage ($/h).
Supervisor Span (workers/ 25.................. 25.
supervisor).
Supervisor Wage Premium 30%................. 30%.
(over fabrication and
assembly wage).
------------------------------------------------------------------------

In response to the November 2022 Preliminary Analysis, Morrison
commented that labor costs and supervisory costs are not reflective of
the current reality, adding that basic factory jobs pay well over $20/
hour.

[[Page 69846]]

Morrison commented that development, testing, and requalification costs
need to be added. Morrison further commented that the costs from the
engineering results are only for the fan components, adding that fan
and housing changes will change heat exchanger performance/safety
controls. (Morrison, No. 27 at p. 3)
In response to the comments from Morrison, DOE notes that the
factory parameters outlined in chapter 5 of the November 2022
Preliminary Analysis TSD, including labor and supervisory costs, are
developed based on manufacturer feedback. Available data indicates that
the values provided in Table IV.13 are representative of the industry
average, but DOE acknowledges that they may vary depending on a variety
of factors. DOE welcomes additional feedback and data regarding these
costs that would better reflect the current market. With respect to
development, testing, and requalification costs, DOE notes that those
costs are typically accounted for in the manufacturer impact analysis
portion of DOE rulemakings. However, because DOE is not proposing to
amend standards in this rulemaking, the manufacturer impact analysis
was not conducted for this NOPD.
Constant Airflow BPM Blower Motor Cost Values
As discussed in section IV.B.1.a of this document, for the NWG-NC,
NWG-C, WG-NC, MWEF/NWMB, and MH-WF/MB product classes, the current
baseline motor technology is a BPM motor, and specifically a CT-BPM
motor. DOE's research suggests that the predominant BPM indoor blower
motors sold on the market today are either a constant-torque or
constant-airflow design. Both types of motors rely on electronic
variable-speed motor systems that are typically mounted in an external
chassis to the back of the motor. CA-BPM motors utilize feedback
control to adjust torque based on ESP in order to maintain a desired
airflow. This differentiates them from CT-BPM motors that will maintain
torque and likely decrease airflow output in environments with high
ESPs. Additionally, CA-BPM motors use feedback control to vary their
output to maintain pre-programmed air flows. DOE has tentatively found
that there are no significant differences in measured FER performance
between furnace fans using CA-BPM and CT-BPM motors; however, CA-BPM
motors are sometimes chosen for other benefits, such as increased
consumer comfort. CA-BPM fan motors typically cost more than CT-BPM
motors while not improving FER. Therefore, as discussed in section
IV.B.1.a, DOE considered the baseline design to include CT-BPM motors
for the NWG-NC, NWG-C, WG-NC, NWEF/NWMB, and MH-EF/MB classes. However,
to better represent costs to consumers, DOE has developed cost values
for CA-BPM that are applied in the LCC analysis to a portion of furnace
fan installations.

Table IV.14--Incremental Cost Adders for BPM Motors
------------------------------------------------------------------------
Incremental cost
increase for CT-
Product class BPM to CA-BPM
(2022$)
------------------------------------------------------------------------
NWG-C, NWG-NC, WG-NC, NWEF/NWMB, MH-NWG-NC, MH-NWG-C, $28.07
and MH-EF/MB........................................
NWO-NC, MH-NWO-NC.................................... 83.67
------------------------------------------------------------------------

Multi-Stage Furnaces
As discussed in section IV.A.2 of this document, DOE has identified
a number of furnace fans in two-stage and modulating furnaces that are
rated at the same relative FER as single-stage furnaces. DOE has
tentatively determined consumers choose to purchase multi-stage
products for the additional thermal comfort offered by furnaces with
multiple stages of heating output. During teardowns, DOE examined
multi-stage furnace designs to analyze the production cost differential
for manufacturers to switch from single-stage to two-stage or
modulating combustion. DOE determined a market-share weighted-average
marginal cost increase of $21.07 for the NWG-C, NWG-NC, WG-NC, NWEF/
NWMB, MH-NWG-NC, MH-NWG-C, and MH-EF/MB classes to change a furnace
from a single-stage to a two-stage design. DOE determined that oil
units with multi-staging were rare and thus not representative of the
market, so adders were not developed for the NWO-NC and MH-NWO-NC
product classes. Where applicable, the additional cost to change to a
two-stage furnace includes the added cost of a two-stage gas valve,
two-speed inducer assembly, additional pressure switch, and additional
controls and wiring. As with the blower motor costs discussed above,
the additional cost of a multi-stage burner is accounted for in the LCC
analysis based on the market penetration of such designs for furnaces.
Scaling to Alternative Input Capacities
DOE also developed equations generate adders for scaling the MPC
results at the representative capacity to the full range of input
capacities available on the market for each motor type. DOE performed
regression analyses on the discrete MPCs for each teardown and their
respective input capacities--which spanned a range of capacities and
airflows and encompassed a range of motor sizes--to generate an
equation for each motor technology that reflects the relationship
between these parameters. These parameters were derived separately for
high-volume (NWGF-C, NWGH-NC, MH-NWGF-NC, MH-NWGF-C, and WGF-NC) and
low-volume (NWOF-NC and MH-NWOF-NC) product classes These equations,
which are presented in Table IV.15, are used in the LCC analysis (see
section IV.E of this document) to analyze the impacts on furnace fans
over the full range of input capacities. To estimate the MPC at a given
input, first the appropriate adder is calculated using the equation and
then the result added to or subtracted from (as applicable) the MPC at
the representative input capacity.
In the November 2022 Preliminary Analysis, DOE also estimated the
relationship between consumer furnace fan cost and furnace fan motor
airflow. However, DOE did not do so for this NOPD analysis because,
upon reviewing market data, DOE found that scaling only by input
capacity sufficiently represented the entire furnace fan market
(including across the range of airflows) so it was unnecessary to also
scale by airflow.

[[Page 69847]]

Table IV.15--Equations for Scaling MPCs to Additional Input Capacities
------------------------------------------------------------------------
Input capacity MPC adder equation: MPC adder = slope * (representative
capacity (kBtu/h)--input capacity (kBtu/h))
-------------------------------------------------------------------------
NWGF-C, NWGF-NC,
MH-NWGF-NC, MH- NWOF-NC and MH-
NWGF-C, WGF-NC NWOF-NC
------------------------------------------------------------------------
Motor Technology.................. Slope Slope
PSC............................... 0.0650 0.7031
Constant-torque BPM............... 0.1395 0.6272
Constant-airflow BPM.............. 0.1603 1.0069
------------------------------------------------------------------------

Backward-Inclined Impellers
For the max-tech efficiency levels, DOE estimated the cost to
manufacture a backward inclined impeller by using manufacturer feedback
along with photographs and specifications found in research reports to
determine cost model inputs to estimate the MPCs of the backward-
inclined impeller. These costs were scaled to different capacities by
evaluating the impact of the backward-inclined impeller on the overall
furnace system, depending on the average cabinet width at that
capacity. DOE estimated the manufacturing cost of implementing a
backward inclined impeller and compared it to the cost of using the
forward inclined impellers that are ubiquitous in furnace fans
currently on the market to develop ``adders'' for backward inclined
impellers. The cost adder for backward-inclined impellers at each
capacity were applied at the max-tech level to estimate the MPC and are
outlined in Table IV.16 of this document.

Table IV.16--Backward-Inclined Impeller Adder
------------------------------------------------------------------------
High Low
Input capacity (kBtu/h) volume volume
(2022$) (2022$)
------------------------------------------------------------------------
40................................................ 28.60 34.15
60................................................ 34.93 41.71
80................................................ 37.21 44.43
100............................................... 55.18 65.89
120............................................... 59.09 70.56
------------------------------------------------------------------------

In response to the November 2022 Preliminary Analysis, Morrison
requested clarification on how DOE concluded that the additional MPC
for a backward-inclined impeller would amount to $22.57. (Morrison, No.
27 at p. 4) Morrison also recommended that DOE reevaluate the process
by which it estimates the costs associated with designing and
manufacturing a backward-inclined impeller. Morrison commented that a
full evaluation of design, tools, and process would be needed to assess
if the technology can meet the expected volume. Morrison recommended
that DOE's analysis consider cost increases for the following: (1)
necessary housing improvements required to realize potential backward-
inclined impeller value; (2) increased strength for motor/fan assembly
mounting hardware, which will ensure tighter gaps between inlet and
impeller and support of the larger impeller; (3) the equipment changes
required to accommodate heat exchanger redesign or safety testing/
requalification; and (4) factory parameters. Morrison commented that
certain installation considerations should be addressed, including: (1)
the need for shipping brackets or added stiffening to account for the
larger impeller and (2) the need for tighter clearances between
impeller and housing to avoid damage during handling. (Morrison, No. 27
at pp. 3, 4)
AHRI commented that backward-inclined impellers are often larger
than comparable forward-inclined impellers, have increased sensitivity
to ESP, and require more sophisticated controls, which will affect the
overall energy use of the product. (AHRI, No. 23 at p. 6) AHRI stated
that the addition of complex controls was not included in DOE's cost
analysis, which skews the economic analysis. (AHRI, No. 23 at p. 3)
Trane added that the cost of incorporating the full EBM-Papst
system was not included in the TSD as it is not just a matter of
replacing the impeller.) Trane commented the TSD assumed that only the
impeller was changed and the cost estimate ignored the need for inlet
cones with close tolerances. Trane commented that those estimates would
be difficult to confirm because the design still needs to be developed.
Trane commented that, as published, the TSD cost estimates and energy
savings showed 44 to 48 percent of NWG furnace consumers negatively
affected and when the full cost of the change is included, Trane
believed these results will be found to be understated. (Trane, No. 22
at pp. 2-3)
Lennox commented that the cost and labor required for installing
backward-inclined impellers in current furnace designs are not fully
accounted for in the TSD. Lennox commented that backward-inclined
impellers are a nascent technology that requires a larger diameter or
higher rotational speed than a centrifugal forward-curved impeller,
adding that backward-inclined impellers are more sensitive to changes
in ESP and likely require motors with extended RPM range and controls.
Lennox further commented that installing a backward-inclined impeller
would require significant furnace redesign that includes modifications
in housing design and airflow path, both of which DOE has acknowledged
adversely impact furnace efficiency. Lennox commented that the study
DOE cites in the TSD (i.e., Wegman, Herman 2003 HVAC Blower Report) was
conducted prior to when residential furnace designs became more compact
in height to accommodate larger evaporator coil designs required to
meet increased DOE conservation standards, and that DOE should take
into account the redesign, safety testing, and other costs placed upon
the consumer before considering implementing the proposed changes.
(Lennox, No. 24 at p. 3)
In response, DOE clarifies that the MPC estimate for backward-
inclined impellers from the November 2022 Preliminary Analysis was
based on a prototype used in research performed by General Electric and
testing performed at national laboratories.\14\ However, for this
rulemaking, DOE has incorporated manufacturer feedback and new market
data to update its MPC estimates for backward-inclined impellers, as

[[Page 69848]]

reported in Tables IV.17--IV.19 of this document. These costs have been
updated to reflect costs to the full furnace system beyond replacing
the impeller component (including advanced controls, changes to the
airflow path, etc.), but DOE acknowledges that given the current
limited use of this technology in consumer furnace fans there is still
uncertainty in how the technology would be applied over the full range
of products currently available.
---------------------------------------------------------------------------

\14\ The backward-inclined impeller prototype used for these
estimates is detailed in a report titled California's Secret Energy
Surplus: The Potential for Energy Efficiency. (Available at:
<a href="http://search.issuelab.org/resource/california-s-secret-energy-surplus-the-potential-for-energy-efficiency.html">search.issuelab.org/resource/california-s-secret-energy-surplus-the-potential-for-energy-efficiency.html</a>) (Last accessed June 7, 2023).
---------------------------------------------------------------------------

DOE did not extend the analysis to account for changes in
tolerances and redesign of the heat exchanger and other furnace
systems. In manufacturer interviews, some manufacturers noted that
airflow changes associated with backward-inclined impellers could
require a different approach to heat exchanger designs. These changes
could necessitate large conversion costs as manufacturing to tight
tolerances and introducing new heat exchanger designs are capital
intensive endeavors. DOE recognizes the potential need for upfront
capital investments and product conversion costs in addition the
estimated changes in MPC, as discussed in section IV.H of this
document.
3. Cost-Efficiency Results
The final results of the FER engineering analysis are the MPCs for
each furnace fan product class analyzed at each efficiency level (and
associated design option), resulting in a cost-efficiency relationship.
The cost-efficiency results are shown in tabular form in Table IV.17
through Table IV.19 in the form of efficiency versus MPC.
(Q<INF>Max</INF> is the airflow, in cfm, at the maximum airflow-control
setting measured during the proposed DOE test procedure.) As described
in section IV.B.2.b of this document, the MPC presented is not for the
entire HVAC product because furnace fans are a component of the HVAC
product in which they are integrated.
As discussed in section IV.B.2.b of this document, separate cost
values were developed for constant-airflow BPM motors and multi-staging
because these premium design elements could add comfort or provide
other benefits but were not incorporated as design options into
efficiency levels for furnace fans used in this analysis.
DOE used the cost-efficiency curves from the engineering analysis
as an input to the LCC analysis to determine the added price of the
more efficient furnace fan components in HVAC equipment sold to the
customer (see section IV.E of this document).

Table IV.17--Cost Efficiency Results by Product Class--NWG-NC, NWG-C, WGF-NC, NWEF/NWMB, and MH-EF/MB
----------------------------------------------------------------------------------------------------------------
Efficiency level
----------------------------------------------------------------------
Design option
----------------------------------------------------------------------
Baseline EL 1
----------------------------------------------------------------------
BPM motor BPM motor + backward-inclined impeller
----------------------------------------------------------------------------------------------------------------
MPC...................................... $108.06..................... $136.13.
----------------------------------------------------------------------
Product Class............................ Maximum Allowable FER Equation
----------------------------------------------------------------------
NWG-NC................................... 0.044 * QMax + 182.......... 0.04 * QMax + 164.
NWG-C.................................... 0.044 * QMax + 195.......... 0.04 * QMax + 176.
WG-NC.................................... 0.044 * QMax + 199.......... 0.04 * QMax + 179.
NWEF/NWMB................................ 0.044 * QMax + 165.......... 0.04 * QMax + 149.
MH-EF-MB................................. 0.044 * QMax + 101.......... 0.04 * QMax + 91.
----------------------------------------------------------------------------------------------------------------

Table IV.18--Cost Efficiency Results by Product Class--MH-NWG-NC and MH-NWG-C
----------------------------------------------------------------------------------------------------------------
Efficiency level
-----------------------------------------------------------------------------
Design option
-----------------------------------------------------------------------------
Baseline EL 1 EL 2
-----------------------------------------------------------------------------
BPM motor + backward-inclined
Improved PSC BPM motor impeller
----------------------------------------------------------------------------------------------------------------
MPC............................... $82.39............... $108.06............. $136.13.
-----------------------------------------------------------------------------
Product Class..................... Maximum Allowable FER Equation
-----------------------------------------------------------------------------
MH-NWG-NC......................... 0.071 * QMax + 222... 0.044 * QMax + 137.. 0.04 * QMax + 123.
MH-NWG-C.......................... 0.071 * QMax + 240... 0.044 * QMax + 148.. 0.04 * QMax + 133.
----------------------------------------------------------------------------------------------------------------

[[Page 69849]]

Table IV.19--Cost Efficiency Results by Product Class--NWO-NC and MH-NWO-NC
----------------------------------------------------------------------------------------------------------------
Efficiency level
-----------------------------------------------------------------------------
Design option
-----------------------------------------------------------------------------
Baseline EL 1 EL 2
-----------------------------------------------------------------------------
BPM motor + backward-inclined
Improved PSC BPM motor impeller
----------------------------------------------------------------------------------------------------------------
MPC............................... $195.61.............. $216.95............. $300.62.
-----------------------------------------------------------------------------
Product Class..................... Maximum Allowable FER Equation
-----------------------------------------------------------------------------
NWO-NC............................ 0.071 * QMax + 382... 0.044 * QMax + 236.. 0.04 * QMax + 212.
MH-NWO-NC......................... 0.071 * QMax + 287... 0.044 * QMax + 176.. 0.04 * QMax + 158.
----------------------------------------------------------------------------------------------------------------

In response to the November 2022 Preliminary Analysis, Morrison
commented that the average consumer purchase price increase of $46-47
that DOE projects for consumer fans operating at EL 1 appears to be
understated, considering the changes and variances in motor costs
depending on whether production occurs in the United States or abroad.
Morrison requested clarification on how DOE arrived at that estimate.
Morrison commented that certain installation considerations should be
addressed, including: (1) the need for shipping brackets or added
stiffening to account for the larger impeller and (2) the need for
tighter clearances between impeller and housing to avoid damage during
handling. (Morrison, No. 27 at p. 4)
In response, DOE notes that the analysis to develop MPCs for each
efficiency level includes physical and virtual product teardowns of
units that incorporate the technology options associated with that
level. Specific motor costs are estimated using cost estimates obtained
through manufacturer feedback, including impacts from production
location and volume. The costs for these teardowns are then weighted
based on several factors, including manufacturer market share and motor
horsepower market share. By using the weighted average of these
teardown costs, DOE develops an MPC that is representative of the
market and takes into account the variation in the market.
Nidec commented during the public meeting that the motor prices for
the preliminary analysis indicated a dramatic increase from a baseline
PSC to an improved PSC when compared to a BPM motor. Nidec commented
that the November 2022 Preliminary Analysis reported a baseline PSC
cost of around $65, an ECM cost of $100, and an improved PSC cost of
$116. Nidec commented that estimates showed a 90 percent increase in
cost for the improved PSC versus the BPM. (Nidec, Public Meeting
Transcript, No. 26 at pp. 19-20)
In response, DOE notes that the $65.73 cost reported in the
November 2022 Preliminary Analysis reflects the MPC for a furnace fan
using an improved PSC motor in the NWGF-C, NWGF-NC, MH-NWGF-NC, MH-
NWGF-C, WGF-NC and NWEF/NWMB product classes, and does not reflect a
baseline PSC motor cost. In the November 2022 Preliminary Analysis, DOE
estimated that the MPC for a furnace fan using an improved PSC motor in
the NWOF-NC and MH-NWOF-NC product classes was $116.25. Therefore, the
difference between these two costs does not reflect the incremental
cost to transition from a baseline PSC motor to an improved PSC motor,
but instead reflects the difference in cost of an improved PSC motor
for the different product classes. This difference is largely due to
the different production volumes assumed for the classes, as outlined
in section IV.B.2 of this document.

C. Markups Analysis

The markups analysis develops appropriate markups (e.g., retailer
markups, distributor markups, contractor markups) in the distribution
chain and sales taxes to convert the MSP estimates derived in the
engineering analysis to consumer prices, which are then used in the LCC
and PBP analysis. At each step in the distribution channel, companies
mark up the price of the product to cover business costs and profit
margin. Before developing markups, DOE defines key market participants
and identifies distribution channels.
DOE used the same distribution channels for furnace fans as it used
for furnaces in the recent energy conservation standards rulemaking for
those products. DOE believes that this is an appropriate approach
because the vast majority of the furnace fans covered in this
rulemaking are a component of a furnace. DOE has concluded that there
is insufficient evidence of a replacement market for furnace fans to
establish a separate distribution channel on that basis.
DOE developed baseline and incremental markups for each actor in
the distribution chain. Baseline markups are applied to the price of
products with baseline efficiency, while incremental markups are
applied to the difference in price between baseline and higher-
efficiency models (the incremental cost increase). The incremental
markup is typically less than the baseline markup and is designed to
maintain similar per-unit operating profit before and after new or
amended standards.\15\
---------------------------------------------------------------------------

\15\ Because the projected price of standards-compliant products
is typically higher than the price of baseline products, using the
same markup for the incremental cost and the baseline cost would
result in higher per-unit operating profit. While such an outcome is
possible, DOE maintains that in markets that are reasonably
competitive it is unlikely that standards would lead to a
sustainable increase in profitability in the long run.
---------------------------------------------------------------------------

To estimate average baseline and incremental mark-ups, DOE relied
on several sources, including: (1) the HARDI 2013 Profit Report (i.e.,
for wholesalers); and (2) U.S. Census Bureau 2017 Economic Census data
on the residential and commercial building construction industry (i.e.,
for general contractors, mechanical contractors, and mobile home
manufacturers). In addition, DOE used the 2005 Air Conditioning
Contractors of America's (``ACCA'') Financial Analysis on the Heating,
Ventilation, Air-Conditioning, and Refrigeration contracting industry
to disaggregate the mechanical contractor mark-ups into replacement and
new construction markets. DOE also used various sources for the
derivation of the mobile home dealer mark-ups (see chapter 6 of the PA
TSD).
DOE derived state and local taxes from data provided by the Sales
Tax

[[Page 69850]]

Clearinghouse.\16\ These data represent weighted averages that include
county and city rates. DOE applied the state sales taxes to match the
state-level markups for wholesalers and mechanical and general
contractors.
---------------------------------------------------------------------------

\16\ Sales Tax Clearinghouse Inc., State Sales Tax Rates Along
with Combined Average City and County Rates (Jan. 4, 2023).
(Available at <a href="http://www.thestc.com/STrates.stm">www.thestc.com/STrates.stm</a>) (Last accessed Jun. 1,
2023).
---------------------------------------------------------------------------

Chapter 6 of the PA TSD provides details on DOE's development of
markups for consumer furnace fans.
Lennox recommended that DOE review the lower incremental markups
for increased consumer furnace fan standard levels considered in the
TSD. Lennox stated that Table ES.3.10 from the TSD shows a
significantly discounted incremental markup from the baseline markup,
which is not logical or aligned with business practices. Lennox
commented that it does not believe an increased standard level would
result in a lower markup for minimum efficiency products from the
current base levels. Lennox recommended that a consistent markup level
be applied instead of discounted incremental markups. (Lennox, No. 24
at p. 7-8)
DOE's incremental markup approach assumes that an increase in
profitability, which is implied by keeping a fixed markup when the
product price goes up, is unlikely to be viable over time in reasonably
competitive markets. DOE recognizes that actors in the distribution
chains are likely to seek to maintain the same markup on appliances in
response to changes in manufacturer sales prices after an amendment to
energy conservation standards. However, DOE believes that retail
pricing is likely to adjust over time as those actors are forces to
readjust their markups to reach a medium-term equilibrium in which per-
unit profit is relatively unchanged before and after standards are
implemented.
DOE acknowledges that markup practices in response to amended
standards are complex and vary across business conditions. However,
DOE's analysis necessarily only considers changes in appliance
offerings that occur in response to amended standards. DOE continues to
maintain that its assumption that standards do not facilitate a
sustainable increase in profitability is reasonable.

D. Energy Use Analysis

The purpose of the energy use analysis is to determine the annual
energy consumption of consumer furnace fans at different efficiencies
in representative U.S. single-family homes, multi-family residences,
and commercial buildings, and to assess the energy savings potential of
increased consumer furnace fan efficiency. The energy use analysis
estimates the range of energy use of consumer furnace fans in the field
(i.e., as they are actually used by consumers). The energy use analysis
provides the basis for other analyses DOE performed, particularly
assessments of the energy savings and the savings in consumer operating
costs that could result from adoption of amended or new standards.
To establish a reasonable range of energy consumption for consumer
furnace fans, DOE primarily used data from the U.S. Energy Information
Administration's (EIA's) most recent 2015 Residential Energy
Consumption Survey (RECS 2015). RECS 2015 is a national sample survey
of housing units that collects statistical information on the
consumption of and expenditures for energy in housing units, along with
data on energy-related characteristics of the housing units and
occupants. RECS 2015 has a sample size of 5,686 housing units and was
constructed by EIA to be a national representation of the household
population in the United States. DOE also considered the use of
consumer furnace fans in commercial applications, based on
characteristics from EIA's most recent 2012 Commercial Building Energy
Consumption Survey (CBECS 2012) for a subset of building types that use
consumer furnace fans covered by a potential standard. DOE utilized
additional data sources to refine the development of a representative
population of buildings for each furnace fan product class, as detailed
in chapter 7 of the PA TSD.
In calculating the energy consumption of furnace fans, DOE adjusted
the energy use from RECS 2015 and CBECS 2012 to normalize for weather.
This was accomplished by adjusting the RECS 2015 household and CBECS
2012 building energy consumption values based on 10-year average
heating degree-day (HDD) and average cooling degree-day (CDD) data for
each geographical region. DOE also accounted for the change in building
shell characteristics by applying the building shell efficiency index
and projected trend in the HDD and CDD in EIA's Annual Energy Outlook
2023.
DOE's analysis takes into account ACCA Manuals J, S, and D methods
to size every household and building in the sample. DOE first uses
Manual J to estimate the house or building design heating load in order
to determine the blower requirements for the assigned heating and
cooling equipment. DOE's analysis considers that typically the furnace
fan is sized based on the maximum cooling capacity required. The
heating and cooling furnace fan speed setting is then varied to match
the recommended/required airflow performance and takes into account
differences in the ductwork system curve in the field.
Chapter 7 of the PA TSD provides details on DOE's energy use
analysis for consumer furnace fans.
WM technologies requested information regarding DOE's use of RECS
data and stated that RECS has stated that the 2015 imputation rates
have a variability of 65.6 percent. (WM Technologies, No. 26 at pp. 31-
32)
In response, DOE notes that EIA administers the RECS to a
nationally representative sample of U.S. housing units. For RECS 2015,
specially trained interviewers collected energy characteristics on the
housing unit, usage patterns, and household demographics. This
information is combined with data from energy suppliers to these homes
to estimate energy costs and usage for heating, cooling, appliances,
and other end uses. The RECS survey data, including energy use, is an
integral ingredient of EIA's Annual Energy Outlook (AEO) and Monthly
Energy Review (MER). EIA's methodology for RECS 2015 is described in
multiple reports.\17\ As described in these reports, RECS 2015
represents a substantial update to the end-use modeling and calibration
methods. For example, in the 2015 RECS, the end-use models follow an
engineering approach, and the calibration--which follows a minimum
variance estimation approach--is based on the relative uncertainties of
and correlations between the end uses being estimated. Instead of
estimating unknown parameters and interpreting their solution values as
in statistical modeling, engineering models improve upon statistical
models by drawing on existing studies. Also, engineering models lead to
more realistic variations across modeled housing units. In addition,
calibration procedures in RECS 2015 use minimum variance estimation,
which better incorporates household characteristics data uncertainty
and recognizes correlations between end uses. DOE notes that households
that use natural gas, propane, or fuel oil predominantly use these
fuels for space heating and water heating. In the case of space
heating, it is heavily seasonal, while water heating

[[Page 69851]]

remains more constant throughout the year.
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\17\ See <a href="http://www.eia.gov/consumption/residential/data/2015/index.php?view=methodology">www.eia.gov/consumption/residential/data/2015/index.php?view=methodology</a> (Last accessed Jan. 3, 2023).
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For the furnace fan energy use analysis, DOE primarily used the
RECS 2015 sample to derive the heating and cooling loads to estimate
furnace fan operating hours in the cooling and heating mode. DOE also
notes that the variables used from RECS 2015 that are used for the
furnace fan analysis have low imputation rates. DOE determined the 95-
percent confidence level for the overall average heating and cooling
energy use values used in its analysis for consumer furnace fans to be
plus or minus 2.7 percent, using EIA's methodology for calculating
sampling error.\18\ DOE also compared the RECS 2015 energy consumption
estimates for furnaces to previous RECS energy consumption estimates
and other available studies, and the Department found that energy
consumption values estimated in 2015 are similar (or within in the RECS
2015 sampling error) of those other sources, after being adjusted for
heating degree-day differences, building shell changes in the stock,
and average furnace efficiency in the stock. This analysis included
comparing homes using consumer furnaces by home sizes and type in the
different studies, including larger sample sized studies at the
national level such as the 2021 American Community Survey (ACS),\19\
the 2021 American Housing Survey (AHS),\20\ the 2022 American Home
Comfort Study,\21\ as well as regional studies such as the 2016-2017
Residential Building Stock Assessment (RBSA) for the northwest region
(Idaho, Montana, Oregon, and Washington),\22\ the 2019 Residential
Building Stock Assessment for the State of New York,\23\ the
Massachusetts Residential Baseline Study,\24\ and the 2019 California
Residential Appliance Saturation Study (RASS).\25\ In conclusion, DOE
finds that RECS 2015 matches other studies' energy use estimates for
furnace and is a reliable source for DOE to use to create a
representative national sample reflecting variations in real world
energy use. See appendix 7A and 7B of the PA TSD for more details.
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\18\ See <a href="http://www.eia.gov/consumption/residential/data/2015/pdf/microdata_v3.pdf">www.eia.gov/consumption/residential/data/2015/pdf/microdata_v3.pdf</a> (Last accessed Jan. 3, 2023).
\19\ U.S. Census Bureau, 2021 American Community Survey
(Available at: <a href="http://www.census.gov/programs-surveys/acs">www.census.gov/programs-surveys/acs</a>) (Last accessed
Jan. 3, 2023).
\20\ Department of Housing and Urban Development (HUD) and U.S.
Census Bureau, 2021 American Housing Survey (Available at:
<a href="http://www.census.gov/programs-surveys/ahs.html">www.census.gov/programs-surveys/ahs.html</a>) (Last accessed Jan. 3,
2023).
\21\ Decision Analyst, 2022 American Home Comfort Study
(Available at: <a href="http://www.decisionanalyst.com/syndicated/homecomfort">www.decisionanalyst.com/syndicated/homecomfort</a>/)
(Last accessed Jan. 3, 2023).
\22\ NEEA, 2016-2017 Residential Building Stock Assessment
(Individua Reports for Single Family, Manufactured Homes and
Multifamily Homes) (Available at: <a href="http://neea.org/data/residential-building-stock-assessment">neea.org/data/residential-building-stock-assessment</a>) (Last accessed Jan. 3, 2023).
\23\ NYSERDA, 2019 Residential Building Stock Assessment
(Available at: <a href="http://www.nyserda.ny.gov/About/Publications/Building-Stock-and-Potential-Studies/Residential-Building-Stock-Assessment">www.nyserda.ny.gov/About/Publications/Building-Stock-and-Potential-Studies/Residential-Building-Stock-Assessment</a>) (Last
accessed Jan. 3, 2023).
\24\ Electric and Gas Program Administrators of Massachusetts,
Massachusetts Residential Building Use and Equipment
Characterization Study (Available at: <a href="http://ma-eeac.org/wp-content/uploads/Residential-Building-Use-and-Equipment-Characterization-Study-Comprehensive-Report-2022-03-01.pdf">ma-eeac.org/wp-content/uploads/Residential-Building-Use-and-Equipment-Characterization-Study-Comprehensive-Report-2022-03-01.pdf</a>) (Last accessed Jan. 3,
2023).
\25\ CEC, 2019 California Residential Appliance Saturation Study
(Available at: <a href="http://www.energy.ca.gov/publications/2021/2019-california-residential-appliance-saturation-study-rass">www.energy.ca.gov/publications/2021/2019-california-residential-appliance-saturation-study-rass</a>) (Last accessed Jan. 3,
2023).
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Morrison commented that DOE noted the CBECS 2012 and RECS 2015
values for HDD and CDD to be different for the same location, and
requested further details that would clarify how the same location can
have different heating and cooling loads for residential furnaces.
(Morrison, No. 27 at p. 6) In response, DOE notes that in the PA TSD
Table 7E.3.1 shows the HDD for each of the 360 weather stations in the
NOAA data set that DOE used for mapping to RECS 2015 and CBECS 2012
individual sampled housing units and buildings. The columns labeled
RECS 2015 shows CDD and HDD for 2015 that would then be comparable to
the HDD/CDD data provided by EIA in the RECS 2015 sample. Similarly,
the columns labeled CBECS 2012 shows CDD and HDD for 2012 that would
then be comparable to the HDD/CDD data provided by EIA in the CBECS
2012 sample.
Morrison requested further insight and verification of DOE's claim
that the electric motor's power is ``taken into account by increasing
the heating load, decreasing the cooling load or both for more
efficient furnace fans.'' (Morrison, No. 27 at p. 3) In addition,
Morrison requested clarification on how DOE calculated circulation mode
power and how it accounts for the varying levels of beneficial (for
heating) and detrimental (for cooling) power use in the circulating-
only mode. Morrison commented that since there is rarely no demand for
either, the split would be about 50/50--half the time the power usage
will be beneficial and half the time detrimental for the household.
(Morrison, No. 27 at p. 4)
DOE clarifies that the energy use analysis takes into account that
heat is being transferred from the furnace fan motor to the airflow in
the ductwork. Since higher efficiency furnace fan design options
improve motor efficiency, less heat is released into the ductwork for
higher efficiency designs. The heat provided by the motor reduces the
heating load and increases the cooling load that the furnace needs to
meet. Therefore, the heat load is increased, while cooling load is
decreased for higher efficiency designs furnace fan options. For
example, for NWOFs the average fuel energy use for going from EL 0 to
EL 1 is increased by about 1 MMBtu/yr on average (or 1.6%), while the
fuel energy use from going from EL 1 to EL 2 is increased by 0.2 MMBtu/
y (or about 0.3%). DOE also took into account the beneficial (for
heating) and detrimental (for cooling) power use in the circulating-
only mode by estimating the monthly energy use for circulating-only
mode and separating the months into heating, cooling, or shoulder
months for each sampled household.
Morrison requested clarification on some of the equations and
variables that DOE utilized in the TSD. Specifically, Morrison
commented on the following: (1) it is not possible to reconcile
equations 7.3, 7.4, and 7.5, because the same coefficients are used to
set up the incongruent state of cfm = watts/cfm; and (2) DOE's use of
the pressure variable in place of the more typical cfm variable when
assessing curves, considering that a reduction in flow--when not
required--will reduce fan energy consumption and a reduction of only 3
percent in flow will be equal to 10 percent in energy savings.
(Morrison, No. 27 at p. 3-4) As explained in chapter 7 and appendix 7B-
D of the PA TSD, the performance curves of CFM vs. pressure (equation
7.3) and watts per cfm (equation 7.5) are combined in the fan power
curve equation (equation 7.4) to produce the wattage usage at the
operating point.
Morrison commented that it identified inconsistencies regarding
DOE's assumptions about consumer use and need. Morrison recommended
that DOE take into account the use of furnaces by some consumers as a
backup to heat pumps and therefore a secondary heat source. Morrison
further noted that, in Table 7A.2.1 and Table 7A.2.2 in the PA TSD,
Morrison identified an inconsistent relationship in the data from RECS
2015 showing reported replacements for various product classes;
Morrison requested clarification on this uneven relationship between
shipment numbers and numbers of households. (Morrison, No. 27 at p. 5)
In response, DOE takes into account gas-fired furnaces used for backup
to heat pumps as well as furnaces used as secondary equipment in its
analysis. The sample for consumer furnace fans

[[Page 69852]]

includes those used in secondary units. Multiple factors could impact
the difference between shipments and the available stock, including
equipment switching (in the no-new standards case), changes in new
construction saturations and growth in different regions due to
demographic shifts, differences in lifetime, etc. Therefore, DOE relies
on the historical shipments data that it deems most correctly reflects
future shipments in 2030 and beyond.
Morrison commented that DOE shows the test procedure for cooling as
having pressures ranging from 0.1 to 0.2 w.c. for conventional split
systems and noted that this reference is from an old test method; the
new test method effective in 2023 has higher pressures (M1 vs M).
(Morrison, No. 27 at p. 5) DOE acknowledges that the new test procedure
should have been referenced in the previous PA TSD. The values in the
TSD from the old test procedure were provided for reference only and
are not directly used in the analysis.
Morrison stated that appendix 7C of the PA TSD (Calculation of
Furnace Blower Fan Energy Consumption), begins with an incorrect
statement by DOE that ``The efficiency consumption (and overall
efficiency) of a blower motor depends on the speed at which the motor
operates, the external static pressure difference across the blower,
and the airflow through the blower.'' Morrison commented that
electrical consumption depends on the design of the furnace, the fan,
and the motor in combination with the ductwork present and all are
important to the FER result. (Morrison, No. 27 at p. 5) DOE agrees that
the efficiency of the furnace fan will depend on the design of the
furnace, the design of the furnace and motor, in combination with the
ductwork. DOE's analysis is built around the selected design options
and current furnace designs that from the engineering analysis provide
the efficiency and energy use characteristics by design option. Once
these design options are fixed the energy consumption depends on the
intersection between the furnace fan performance curves and the
ductwork present.
Morrison commented that all discussion in appendix 7C of the PA TSD
misses the point and purpose of the furnace operation and added that
Figure 7C.1.1 (Power Determination) uses pressure as the x-axis
independent variable, but the relevant independent variable is the
volume flow rate with the assumption of a relatively fixed air density.
Morrison commented that performance tables in furnace literature use
pressure as the variable, stating that this is the easy method of
operational determination for installers in the field--but not an
appropriate way to conduct a technical analysis of consumer furnace
fans. Morrison further commented that 7C.1 contains an error: air power
is not proportional to air speed but rather volume rate of airflow.
(Morrison, No. 27 at p. 6) Morrison also commented that, in section 7C-
4 of the PA TSD, the method of analysis is confusing and the first two
assumptions listed on 7C-4 are incorrect: (1) Regarding the assumption
that slope of airflow and watts/cfm does not vary within the same motor
technology, Morrison commented that performance curves for furnace fans
will have varying slope dependent on the fan, motor and furnace system
for the same motor technology, and that some small range changes could
appear to have the same slope but the entirety of the performance range
of interest will have variation; (2) Regarding the assumption that BPM
(constant airflow) and PSC with controls always maintain the same
airflow, Morrison commented that BPM (constant airflow) will closely
maintain the airflow rate until the maximum power of the motor is
achieved and then it will enter constant power mode, and unless there
are new motor controller designs available in commerce, PSC motors with
controls will adjust along a path of constant torque until the power
limit is reached then along a constant power mode. Morrison added that
this is also true for BPM (i.e., constant torque). (Morrison, No. 27 at
p. 6) In addition, Morrison commented that the curves in section 7C.3
of the PA TSD have a curious feature that gives the reader the
suggestion that the BPM-CT uses less power that the BPM-CA, and that
the use of pressure for the independent variable gives rise to this
curious effect. Morrison commented that at the same operating point,
flow, and pressure, the two motors (assuming same design/manufacturer)
in the same appliance (same furnace and fan) would have virtually the
same efficiency and thus the watts consumed would be about the same.
Morrison stated that because of this oddity, further limited response
time was not spent analyzing these curves in greater detail, but
Morrison commented that the oddity raises question as to the validity
of the analysis as it relates to real products. (Morrison, No. 27 at p.
6)
DOE's analysis relied on the manufacturer product literature and
how the data was presented in terms of using pressure as the variable
for the furnace fan equations. DOE contends that since the furnace fan
energy use operates at a few specific operating conditions (one or more
at heating, cooling, and/or continuous fan), that DOE's approach is
valid in capturing the field energy use for furnace fans. Additionally,
DOE validated its energy use methodology approach by comparing it to
available field data measuring energy use of furnace fans in the field
26 27 and building model data.\28\ DOE acknowledges that it
is expected to see a higher pressure for constant airflow BPM and the
watts/cfm should be the same for both constant airflow BPM and constant
torque BPM. DOE notes that there may be inconsistency because of some
errors made in the PA documentation. However, for this NOPD analysis,
DOE has largely maintained the methodology from the preliminary
analysis. DOE would like to note that even if there were further
updates to the energy use analysis, it would likely result in lower
energy savings and consumer net cost, and thus the conclusions of the
determination would remain the same.
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\26\ Pigg, S. Central Electricity Use by New Furnaces: A
Wisconsin Field Study. 2003. Accessible at: <a href="http://www.proctoreng.com/dnld/WIDOE2013.pdf">www.proctoreng.com/dnld/WIDOE2013.pdf</a> (last accessed: Jun. 1, 2023).
\27\ Wilcox, B., J. Proctor, R. Chitwood, and K. Nittler.
Furnace Fan Watt Draw and Air Flow in Cooling and Air Distribution
Modes. 2008 California Building Energy Efficiency Standards. 2006.
\28\ See <a href="http://eta-publications.lbl.gov/sites/default/files/furnace_blower_electricity_national_and_regional_savings_potential_lbnl_417e.pdf">eta-publications.lbl.gov/sites/default/files/furnace_blower_electricity_national_and_regional_savings_potential_lbnl_417e.pdf</a>.
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Trane commented that according to DOE, the RECS results regarding
heating energy use identifies NWG-NC as 6.8 and NWG-C as 43.3 MMBtu.
However, Trane commented that based on industry sales, their values
should be almost equal, or NWG-NC should be greater than NWG-C. (Trane,
No. 22 at p. 3) DOE clarifies that its analysis assumes that in 2030
the heating load is 26.1 MMBtu/yr for NWG-NC and 37.1 MMBty/yr for NWG-
C. This is based on shipments data by states that show that Northern
states tend to have a much larger fraction of condensing furnaces
compared to Rest of Country states. Therefore, the NWG-C sample
includes more homes in colder climates with higher heating loads.
Trane commented that DOE defines the AFUE of a new unit as 96
percent, whereas a recent NOPR defines the minimum AFUE as 95 percent.
(Trane, No. 22 at p. 3) Trane questioned DOE's assumption that the AFUE
of an existing unit is 92 percent, stating that this value should be
closer to 95 percent given that a unit's AFUE does not change much over
time. (Trane, No. 22 at p. 3) Trane also commented that because DOE
identifies the AFUE for an existing

[[Page 69853]]

NWG-C unit to be less than that of a new NWG-C unit, then the AFUE for
an existing NWG-NC unit should also be less than that of a new NWG-NC
unit. (Trane, No. 22 at p. 3) DOE clarifies that it defined the AFUE of
new units based on the projected market shares by AFUE in 2030. For
NWG-C units, the market share was also divided into North and Rest of
Country and ranged from 90% AFUE to 98%, with an overall shipment
weighted average 95% AFUE. In terms of the existing AFUE unit, DOE
analysis is set such that the AFUE of the existing unit is always equal
or less than the AFUE of the new unit.
Trane commented that the corre

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