Energy Conservation Program for Consumer Products and Certain Commercial and Industrial Equipment: Test Procedures for Consumer and Commercial Water Heaters, 20115-20147 [2015-07932]
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Vol. 80
Tuesday,
No. 71
April 14, 2015
Part III
Department of Energy
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10 CFR Parts 429, 430, and 431
Energy Conservation Program for Consumer Products and Certain
Commercial and Industrial Equipment: Test Procedures for Consumer and
Commercial Water Heaters; Proposed Rule
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Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
DEPARTMENT OF ENERGY
10 CFR Parts 429, 430, and 431
[EERE–2015–BT–TP–0007]
RIN 1904–AC91
Energy Conservation Program for
Consumer Products and Certain
Commercial and Industrial Equipment:
Test Procedures for Consumer and
Commercial Water Heaters
Office of Energy Efficiency and
Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking.
AGENCY:
As required by the Energy
Policy and Conservation Act of 1975
(EPCA), as amended, the U.S.
Department of Energy (DOE) proposes to
establish a mathematical conversion
factor for the purpose of translating
efficiency ratings for water heaters
under the test method currently in effect
to the ratings under the amended test
method promulgated by DOE in a final
rule published on July 11, 2014
(hereinafter referred to as the ‘‘the July
2014 final rule’’). Compliance with the
amended test procedure is required
beginning on the later of: one year after
the publication of a final rule that
establishes a mathematical conversion
factor, or December 31, 2015. This
rulemaking document proposes a
mathematical conversion factor which
may be used to convert the existing
efficiency ratings under the current
Federal test procedure to efficiency
ratings under the test procedure adopted
in the July 2014 final rule for water
heater basic models manufactured,
tested and certified prior to the
compliance date of the amended test
procedure. The amended test procedure
applies to all covered consumer water
heaters and the covered commercial
water heating equipment with
residential applications defined in the
July 2014 final rule as a ‘‘residentialduty commercial water heater.’’ In
addition, this document proposes
amendments to the minimum energy
conservation standards for consumer
water heaters and residential-duty
commercial water heaters to account for
the impact of the new metric, but does
not alter the stringency of the existing
energy conservation standards. While
DOE has not planned a public meeting
to discuss this proposal, DOE is willing
to consider a request to hold a meeting.
DATES: Comments: DOE will accept
comments, data, and information
regarding this notice of proposed
rulemaking (NOPR) no later than May
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SUMMARY:
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14, 2015. See section V, ‘‘Public
Participation,’’ for details.
ADDRESSES: All comments submitted
must identify the NOPR for the
Conversion Factor for Test Procedures
for Consumer and Certain Commercial
Water Heaters, and provide docket
number EERE–2015–BT–TP–0007 and/
or RIN 1904–AC91. Interested persons
are encouraged to submit comments
using the Federal eRulemaking Portal at
www.regulations.gov. Follow the
instructions for submitting comments.
Alternatively, interested persons may
submit comments by any of the
following methods:
• Email: ConsumerCommWaterHtrs
2015TP0007@ee.doe.gov. Include the
docket number and/or RIN in the
subject line of the message. Submit
electronic comments in WordPerfect,
Microsoft Word, PDF, or ASCII file
format, and avoid the use of special
characters or any form of encryption.
• Postal Mail: Ms. Brenda Edwards,
U.S. Department of Energy, Building
Technologies Office, Mailstop EE–5B,
1000 Independence Avenue SW.,
Washington, DC 20585–0121. If
possible, please submit all items on a
compact disc (CD), in which case it is
not necessary to include printed copies.
• Hand Delivery/Courier: Ms. Brenda
Edwards, U.S. Department of Energy,
Building Technologies Office, 950
L’Enfant Plaza SW., 6th Floor,
Washington, DC 20024. Telephone:
(202) 586–2945. If possible, please
submit all items on a CD, in which case
it is not necessary to include printed
copies.
No telefacsimilies (faxes) will be
accepted. For detailed instructions on
submitting comments and additional
information on the rulemaking process,
see section V of this document (Public
Participation).
Docket: The docket is available for
review at www.regulations.gov,
including Federal Register notices,
comments, and other supporting
documents/materials. All documents in
the docket are listed in the
www.regulations.gov index. However,
not all documents listed in the index
may be publicly available, such as
information that is exempt from public
disclosure.
A link to the docket Web page can be
found at: https://www.regulations.gov/
#!docketDetail;D=EERE-2015-BT-TP0007. This Web page contains a link to
the docket for this notice of proposed
rulemaking on the www.regulations.gov
site. The www.regulations.gov Web page
contains simple instructions on how to
access all documents, including public
comments, in the docket. See section V,
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‘‘Public Participation,’’ for information
on how to submit comments through
www.regulations.gov.
For information on how to submit a
comment or review other public
comments and the docket, contact Ms.
Brenda Edwards at (202) 586–2945 or by
email: Brenda.Edwards@ee.doe.gov.
FOR FURTHER INFORMATION CONTACT: Ms.
Ashley Armstrong, 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.
Telephone: (202) 586–6590. Email:
Ashley.Armstrong@ee.doe.gov.
Mr. Eric Stas, U.S. Department of
Energy, Office of the General Counsel,
GC–33, 1000 Independence Avenue
SW., Washington, DC 20585–0121.
Telephone: (202) 586–9507. Email:
Eric.Stas@hq.doe.gov.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Authority and Background
II. Summary of the Notice of Proposed
Rulemaking
III. Discussion
A. Stakeholder Comments on Other
Rulemakings
B. Scope
1. Test Procedure and Energy Conservation
Standards Coverage
2. Units on the Market
C. Potential Approaches for Developing
Conversions
1. Background Regarding Changes to
Existing Test Procedures
2. Analytical Methods
3. Empirical Regression
D. Testing Conducted for the Mathematical
Conversion
1. Consumer Water Heater Testing
2. Residential-Duty Commercial Water
Heater Testing
E. Testing Results and Analysis of Test
Data
1. Impact of Certain Water Heater
Attributes on Efficiency Ratings
2. Conversion Factor Derivation
3. Energy Conservation Standard
Derivation
F. Certification and Labeling Issues
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility
Act
C. Review Under the Paperwork Reduction
Act of 1995
D. Review Under the National
Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates
Reform Act of 1995
H. Review Under the Treasury and General
Government Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General
Government Appropriations Act, 2001
K. Review Under Executive Order 13211
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L. Review Under Section 32 of the Federal
Energy Administration Act of 1974
V. Public Participation
A. Submission of Comments
B. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary
I. Authority and Background
Title III Part B 1 of the Energy Policy
and Conservation Act of 1975 (‘‘EPCA’’
or, ‘‘the Act’’), Public Law 94–163 (42
U.S.C. 6291–6309, as codified) sets forth
a variety of provisions designed to
improve energy efficiency and
established the Energy Conservation
Program for Consumer Products Other
Than Automobiles.2 These include
consumer water heaters, one subject of
this document. (42 U.S.C. 6292(a)(4))
Title III, Part C 3 of EPCA, Public Law
94–163 (42 U.S.C. 6311–6317, as
codified), added by Public Law 95–619,
Title IV, Sec. 441(a), established the
Energy Conservation Program for
Certain Industrial Equipment, which
includes the commercial water heating
equipment that is another subject of this
rulemaking. (42 U.S.C. 6311(1)(K))
Under EPCA, energy conservation
programs generally consist of four parts:
(1) Testing; (2) labeling; (3) establishing
Federal energy conservation standards;
and (4) certification and enforcement
procedures. The testing requirements
consist of test procedures that
manufacturers of covered products and
equipment must use as the basis for
certifying to DOE that their products
and equipment comply with the
applicable energy conservation
standards adopted under EPCA, and for
making other representations about the
efficiency of those products. (42 U.S.C.
6293(c); 42 U.S.C. 6295(s); 42 U.S.C.
6314) Similarly, DOE must use these
test procedures to determine whether
such products and equipment comply
with any relevant standards
promulgated under EPCA. (42 U.S.C.
6295(s))
EPCA, as codified, contains what is
known as an ‘‘anti-backsliding’’
provision, which prevents the Secretary
from prescribing any amended standard
that either increases the maximum
allowable energy use or decreases the
minimum required energy efficiency of
a covered product. (42 U.S.C.
6295(o)(1)) Also, the Secretary may not
prescribe an amended or new standard
if interested persons have established by
a preponderance of the evidence that
the standard is likely to result in the
unavailability in the United States of
any covered product type (or class) of
performance characteristics (including
reliability), features, sizes, capacities,
and volumes that are substantially the
same as those generally available in the
United States. (42 U.S.C. 6295(o)(4))
EPCA prescribed energy conservation
standards for consumer water heaters
(42 U.S.C. 6295(e)(1)), and directed DOE
to conduct further rulemakings to
determine whether to amend these
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standards (42 U.S.C. 6295(e)(4)(A)–(B)).
DOE notes that under 42 U.S.C.
6295(m), the agency must periodically
review its already established energy
conservation standards for a covered
product. Under this requirement, the
next review that DOE would need to
conduct must occur no later than six
years from the issuance of a final rule
establishing or amending a standard for
a covered product.
On April 16, 2010, DOE published a
final rule (hereinafter referred to as the
‘‘April 2010 final rule’’) that amended
the energy conservation standards for all
classes of consumer water heaters,
except for tabletop and electric
instantaneous water heaters, for which
the existing energy conservation
standards were left in place. 75 FR
20112. The standards adopted by the
April 2010 final rule are shown below
in Table I.1. These standards will apply
to all water heater products listed in
Table I.1 and manufactured in, or
imported into, the United States on or
after April 16, 2015, for all classes,
except for tabletop and electric
instantaneous. For these latter two
classes, compliance with these
standards has been required since April
15, 1991. 55 FR 42162 (Oct. 17, 1990).
Current energy conservation standards
for consumer water heaters can be found
in DOE’s regulations at 10 CFR
430.32(d).
TABLE I.1—ENERGY CONSERVATION STANDARDS FOR CONSUMER WATER HEATERS
Product class
Rated storage volume ***
Gas-fired Storage ................................
≥20 gal and ≤55 gal ........................................................................................
>55 gal and ≤100 gal .....................................................................................
≤50 gal ............................................................................................................
≥20 gal and ≤55 gal ........................................................................................
>55 gal and ≤120 gal .....................................................................................
≥20 gal and ≤120 gal ......................................................................................
<2 gal ..............................................................................................................
<2 gal ..............................................................................................................
Oil-fired Storage ..................................
Electric Storage ...................................
Tabletop * ............................................
Gas-fired Instantaneous ......................
Electric Instantaneous * .......................
Energy factor **
0.675¥(0.0015 × Vs)
0.8012¥(0.00078 × Vs)
0.68¥(0.0019 × Vs)
0.96¥(0.0003 × Vs)
2.057¥(0.00113 × Vs)
0.93¥(0.00113 × Vs)
0.82¥(0.0019 × Vs)
0.93¥(0.00132 × Vs)
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*Tabletop and electric instantaneous standards were not updated by the April 2010 final rule.
** Vs is the ‘‘Rated Storage Volume’’ which equals the water storage capacity of a water heater (in gallons), as specified by the manufacturer.
*** Rated Storage Volume limitations result from either a lack of test procedure coverage or from divisions created by DOE when adopting
standards. The division at 55 gallons for gas-fired and electric storage water heaters was established in the April 16, 2010 final rule amending
energy conservation standards. 75 FR 20112. The other storage volume limitations shown in this table are a result of test procedure applicability,
and are discussed in the July 2014 final rule. 79 FR 40542 (July 11, 2014).
The initial Federal energy
conservation standards and test
procedures for commercial water
heating equipment were added to EPCA
as an amendment made by the Energy
Policy Act of 1992 (EPACT). (42 U.S.C.
6313(a)(5)) These initial energy
conservation standards corresponded to
the efficiency levels contained in the
American Society of Heating,
Refrigerating and Air-Conditioning
Engineers (ASHRAE) Standard 90.1
(ASHRAE Standard 90.1) in effect on
October 24, 1992. The statute provided
that if the efficiency levels in ASHRAE
Standard 90.1 were amended after
October 24, 1992, the Secretary must
establish an amended uniform national
standard at new minimum levels for
each equipment type specified in
ASHRAE Standard 90.1, unless DOE
determines, through a rulemaking
supported by clear and convincing
evidence, that national standards more
1 For editorial reasons, upon codification in the
U.S. Code, Part B was redesignated Part A.
2 All references to EPCA in this document refer
to the statute as amended through the American
Energy Manufacturing Technical Corrections Act
(AEMTCA), Public Law 112–210 (Dec. 18, 2012).
3 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
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stringent than the new minimum levels
would result in significant additional
energy savings and be technologically
feasible and economically justified. (42
U.S.C. 6313(a)(6)(A)(ii)(I)–(II)) DOE
issued the most recent final rule for
commercial water heating equipment on
January 12, 2001 (hereinafter, the
‘‘January 2001 final rule’’), which
adopted the amended energy
conservation standards at levels
equivalent to efficiency levels in
ASHRAE Standard 90.1, as it was
revised in October 1999. 66 FR 3336.
The current standards for commercial
water heating equipment are presented
in Table I.2 and may be found in DOE’s
regulations at 10 CFR 431.110.
TABLE I.2—ENERGY CONSERVATION STANDARDS FOR COMMERCIAL WATER HEATING EQUIPMENT
Energy conservation standard *
Equipment
Size
Electric storage water heaters ...............................................
Gas-fired storage water heaters ............................................
Oil-fired storage water heaters ..............................................
Gas-fired instantaneous water heaters and hot water supply
boilers **.
Oil-fired instantaneous water heaters and hot water supply
boilers **.
Minimum thermal efficiency
(%)
Maximum standby loss c
All ...........................................
≤155,000 Btu/hr .....................
>155,000 Btu/hr .....................
≤155,000 Btu/hr .....................
>155,000 Btu/hr .....................
<10 gal ...................................
N/A
80
80
78
78
80
0.30 + 27/Vm (%/hr)
Q/800 + 110(Vr) 1, 2 (Btu/hr)
Q/800 + 110(Vr) 1, 2 (Btu/hr)
Q/800 + 110(Vr) 1, 2 (Btu/hr)
Q/800 + 110(Vr) 1, 2 (Btu/hr)
N/A
≥10 gal ...................................
<10 gal ...................................
80
80
Q/800 + 110(Vr) 1,
N/A
2
(Btu/hr)
≥10 gal ...................................
78
Q/800 + 110(Vr) 1,
2
(Btu/hr)
Equipment
Size
Minimum thermal insulation
Unfired hot water storage tank ..............................................
All ...........................................
R–12.5
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* Vm is the measured storage volume, and Vr is the rated volume, both in gallons. Q is the nameplate input rate in Btu/hr.
** For hot water supply boilers with a capacity of less than 10 gallons: (1) The standards are mandatory for products manufactured on and
after October 21, 2005, and (2) products manufactured prior to that date, and on or after October 23, 2003, must meet either the standards listed
in this table or the applicable standards in subpart E of this part for a ‘‘commercial packaged boiler.’’
*** Water heaters and hot water supply boilers having more than 140 gallons of storage capacity need not meet the standby loss requirement
if: (1) The tank surface area is thermally insulated to R–12.5 or more; (2) a standing pilot light is not used; and (3) for gas or oil-fired storage
water heaters, they have a fire damper or fan-assisted combustion.
On December 18, 2012, the American
Energy Manufacturing Technical
Corrections Act (AEMTCA), Public Law
112–210, was signed into law. In
relevant part, it amended EPCA to
require that DOE publish a final rule
establishing a uniform efficiency
descriptor and accompanying test
methods for covered consumer water
heaters and commercial water heating
equipment within one year of the
enactment of AEMTCA. (42 U.S.C.
6295(e)(5)(B)) The final rule must
replace the current energy factor,
thermal efficiency, and standby loss
metrics with a uniform efficiency
descriptor. (42 U.S.C. 6295(e)(5)(C)) The
July 2014 final rule fulfilled these
requirements. AEMTCA requires that,
beginning one year after the date of
publication of DOE’s final rule
establishing the uniform descriptor (i.e.,
July 13, 2015), the efficiency standards
for the consumer water heaters and
residential-duty commercial water
heaters identified in the July 2014 final
rule must be denominated according to
the uniform efficiency descriptor
established in that final rule (42 U.S.C.
6295(e)(5)(D)), and that DOE must
develop a mathematical conversion
factor for converting the measurement of
efficiency for those water heaters from
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the test procedures and metrics
currently in effect to the new uniform
energy descriptor. (42 U.S.C.
6295(e)(5)(E)(i)–(ii)) Consumer water
heaters and residential-duty commercial
water heaters manufactured prior to the
effective date of the final rule (i.e., July
13, 2015) that comply with the
efficiency standards and labeling
requirements in effect prior to the final
rule shall be considered to comply with
the final rule and with any revised
labeling requirements established by the
Federal Trade Commission (FTC) to
carry out the final rule. (42 U.S.C.
6295(e)(5)(K))
AEMTCA also requires that the
uniform efficiency descriptor and
accompanying test method apply, to the
maximum extent practicable, to all
water-heating technologies currently in
use and to future water-heating
technologies. (42 U.S.C. 6295(e)(5)(H))
AEMTCA allows DOE to provide an
exclusion from the uniform efficiency
descriptor for specific categories of
otherwise covered water heaters that do
not have residential uses, that can be
clearly described, and that are
effectively rated using the current
thermal efficiency and standby loss
descriptors. (42 U.S.C. 6295(e)(5)(F))
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AEMTCA outlines DOE’s various
options for establishing a new uniform
efficiency descriptor for water heaters.
The options that AEMTCA provides to
DOE include: (1) A revised version of
the energy factor descriptor currently in
use; (2) the thermal efficiency and
standby loss descriptors currently in
use; (3) a revised version of the thermal
efficiency and standby loss descriptors;
(4) a hybrid of descriptors; or (5) a new
approach. (42 U.S.C. 6295(e)(5)(G))
Lastly, AEMTCA requires that DOE
invite stakeholders to participate in the
rulemaking process, and that DOE
contract with the National Institute of
Standards and Technology (NIST), as
necessary, to conduct testing and
simulation of alternative descriptors
identified for consideration. (42 U.S.C.
6295(e)(5)(I)–(J))
As noted previously, in the July 2014
final rule, DOE amended its test
procedure for consumer and certain
commercial water heaters. 79 FR 40542
(July 11, 2014). The July 2014 final rule
for consumer and certain commercial
water heaters satisfied the AEMTCA
requirements to develop a uniform
efficiency descriptor to replace the
existing energy factor, thermal
efficiency and standby loss metrics. The
amended test procedure includes
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provisions for determining the uniform
energy factor (UEF), as well as the
annual energy consumption of these
products. Furthermore, the uniform
descriptor test procedure can be applied
to: (1) Most consumer water heaters
(including certain consumer water
heaters that are covered products under
EPCA’s definition of ‘‘water heater’’ at
42 U.S.C. 6291(27), but that are not
addressed by the existing test method);
and (2) to commercial water heaters that
have residential applications. The major
modifications to the existing DOE test
procedure to establish the uniform
descriptor test method included the use
of multiple draw patterns and different
draw patterns, and changes to the setpoint temperature. In addition, DOE
expanded the scope of the test method
to include test procedure provisions that
are applicable to water heaters with
storage volumes between 2 gallons (7.6
L) and 20 gallons (76 L), and to clarify
applicability to electric instantaneous
water heaters. DOE also established a
new equipment class and corresponding
definition for ‘‘residential-duty
commercial water heater.’’
This rulemaking will satisfy the
requirements of AEMTCA to develop a
mathematical conversion factor for
converting the measurement of
efficiency for covered water heaters
from the test procedures and metrics
currently in effect to the new uniform
energy descriptor. (42 U.S.C.
6295(e)(5)(E))
II. Summary of the Notice of Proposed
Rulemaking
This notice of proposed rulemaking
proposes to establish a mathematical
conversion factor between the current
rated values under the existing water
heaters test procedures (i.e., energy
factor, first-hour rating, maximum
gallons per minute (GPM) rating,
thermal efficiency, standby loss), and
the amended test procedure for the
uniform efficiency descriptor (i.e., UEF
and first-hour rating or maximum GPM
rating), which was established in the
July 2014 final rule. As discussed
previously, the water heater test
procedure was updated to be more
representative of conditions
encountered in the field (including
modifications to both the test conditions
and the draw patterns) and to expand
the scope of the test procedure to apply
to certain commercial and consumer
water heaters that are currently not
addressed by the test procedure.
The mathematical conversion factor
required by AEMTCA is a bridge
between the efficiency ratings obtained
through testing under the existing test
procedures and those obtained under
the uniform efficiency descriptor test
procedure published in the July 2014
final rule. Therefore, the mathematical
conversion factor will only apply to
products and equipment covered by the
existing test procedure, as products and
equipment that are not covered by the
existing test method would not have
ratings to be converted. Certain water
heater types are not covered by the
mathematical conversion factor, either
because they are not covered by the
uniform efficiency descriptor
established by the July 2014 final rule
(e.g., commercial heat pump water
heaters), or because they are not covered
by DOE’s existing test procedure (e.g.,
water heaters with storage volumes
between 2 and 20 gallons). The water
heater types that are and are not covered
by the mathematical conversion factor
are discussed in detail in section III.B of
this notice of proposed rulemaking.
To help develop the mathematical
conversion factor, DOE conducted a
series of tests on the types of water
heaters included within the scope of
this rulemaking (i.e., those described in
section III.B and that pass the minimum
standards for consumer 4 and
commercial water heaters). An
investigation of DOE’s Compliance
Certification Management System
(CCMS) and the Air-Conditioning,
Heating, and Refrigeration Institute’s
(AHRI) water-heating databases found
that certain types of water heaters are
20119
not available for purchase on the
market; these units are discussed in
section III.B. As there are no existing
water heaters in these product classes,
and the purpose of the conversion factor
is to convert the efficiency ratings of
existing water heaters, DOE did not
include these water heaters in its
analysis for the mathematical
conversion factor.
DOE selected 72 water heaters for
testing, including: 43 consumer storage
units, 22 consumer instantaneous units,
and 7 commercial residential-duty
storage units. Units were selected to
represent the range of rated values
available on the market (i.e., storage
volume, input rate, first-hour rating,
maximum GPM, recovery efficiency,
energy factor, thermal efficiency, and
standby loss). DOE used data obtained
from testing, along with analytical
methods described in section III.C, to
calculate the conversion factors
described in this document. DOE
investigated several approaches to
derive these conversion factors, which
are discussed in detail in section III.C of
this notice of proposed rulemaking.
DOE developed different conversion
factors for determining first-hour rating,
maximum GPM, and UEF based on the
existing ratings for consumer and
residential-duty commercial water
heaters, which can be found in section
III.E.
DOE then used the conversion factors
to derive minimum energy conservation
standards based on the UEF, as shown
in Table II.1 and Table II.2. The
proposed standards based on UEF are
neither more nor less stringent than the
existing standards for consumer water
heaters based on energy factor (as
amended by the April 2010 final rule)
and for commercial water-heating
equipment based on the thermal
efficiency and standby loss metrics. The
methodology for deriving the proposed
UEF standards is discussed in detail in
section III.E.3 of this notice of proposed
rulemaking.
TABLE II.1—PROPOSED CONSUMER WATER HEATER ENERGY CONSERVATION STANDARDS
Rated storage volume
Draw pattern
Gas-fired Storage ............................................
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Product class
≥20 gal and ≤55 gal ........................................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
>55 gal and ≤100 gal ......................................
Oil-fired Storage ..............................................
4 DOE published a final rule on April 16, 2010,
that will require compliance with amended energy
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≤50 gal ............................................................
conservation standards beginning on April 16,
2015. 75 FR 20112. DOE focused the testing of
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Uniform energy factor *
0.3263¥(0.0019
0.5891¥(0.0019
0.6326¥(0.0013
0.7128¥(0.0025
0.5352¥(0.0007
0.7375¥(0.0009
0.7704¥(0.0010
0.7980¥(0.0010
0.2267¥(0.0014
×
×
×
×
×
×
×
×
×
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
consumer water heaters on units that would comply
with the amended standards.
E:\FR\FM\14APP2.SGM
14APP2
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TABLE II.1—PROPOSED CONSUMER WATER HEATER ENERGY CONSERVATION STANDARDS—Continued
Product class
Rated storage volume
Electric Storage ...............................................
Draw pattern
≥20 gal and ≤55 gal ........................................
>55 gal and ≤120 gal ......................................
Tabletop Storage .............................................
≥20 gal and ≤100 gal ......................................
Gas-fired Instantaneous ..................................
Electric Instantaneous .....................................
<2 gal ..............................................................
<2 gal ..............................................................
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
All ..........................
All ..........................
Uniform energy factor *
0.4867¥(0.0006
0.6016¥(0.0012
0.6529¥(0.0005
0.8268¥(0.0002
0.9393¥(0.0004
0.9683¥(0.0007
0.9656¥(0.0004
1.2701¥(0.0011
1.9137¥(0.0011
2.0626¥(0.0011
2.1858¥(0.0011
0.6808¥(0.0022
0.8770¥(0.0012
0.9063¥(0.0009
0.9302¥(0.0006
0.8036¥(0.0019
0.9192¥(0.0013
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as specified by the manufacturer.
TABLE II.2—PROPOSED RESIDENTIAL-DUTY COMMERCIAL WATER HEATER ENERGY CONSERVATION STANDARDS
Product class
Draw pattern
Gas-fired Storage ..........................................................................................................................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Oil-fired Storage ............................................................................................................................
Uniform energy factor
0.3261
0.5219
0.5585
0.6044
0.3206
0.5577
0.6027
0.6446
¥
¥
¥
¥
¥
¥
¥
¥
(0.0006
(0.0008
(0.0006
(0.0005
(0.0006
(0.0019
(0.0019
(0.0018
×
×
×
×
×
×
×
×
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
asabaliauskas on DSK5VPTVN1PROD with NOTICES
*Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as specified by the manufacturer.
EPCA requires that a covered water
heater be considered to comply with the
July 2014 final rule on and after July 13,
2015 (the effective date of the July 2014
final rule) and with any revised labeling
requirements established by the Federal
Trade Commission to carry out the July
2014 final rule if the covered water
heater was manufactured prior to July
13, 2015, and complied with the
efficiency standards and labeling
requirements in effect prior to July 13,
2015. (42 U.S.C. 6295(e)(5)(K)) Upon the
effective date of the final rule
establishing the mathematical
conversion factor (this rulemaking),
compliance with energy conservation
standards will be exclusively
determined based on the standards as
defined in terms of UEF, which will be
established by this rulemaking. DOE has
tentatively concluded that there will be
three possible compliance paths
available to manufacturers for basic
models of consumer water heaters that
were certified before July 13, 2015:
(1) Convert the certified rating for
energy factor obtained using the test
procedure contained in Appendix E to
subpart B of 10 CFR part 430 of the
January 1, 2015 edition of the CFR along
with the applicable sampling provisions
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in 10 CFR part 429 from energy factor
to uniform energy factor using the
applicable mathematical conversion
factor; or
(2) Conduct testing using the test
procedure contained at Appendix E to
subpart B of 10 CFR part 430, effective
July 13, 2015, along with the applicable
sampling provisions in 10 CFR part 429;
or
(3) Where permitted, apply an
alternative efficiency determination
method (AEDM) pursuant to 10 CFR
429.70 to determine the represented
efficiency of basic models for those
categories of consumer water heaters
where the ‘‘tested basic model’’ was
tested using the test procedure
contained at Appendix E to subpart B of
10 CFR part 430, effective July 13, 2015.
Similarly, DOE has tentatively
concluded that there will be three
possible compliance paths available to
manufacturers for basic models of
commercial residential-duty water
heaters that were certified before July
13, 2015:
(1) Convert the certified rating for
thermal efficiency and standby loss
obtained using the test procedure
contained in 10 CFR 431.106 of the
January 1, 2015 edition of the CFR along
with the applicable sampling provisions
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Fmt 4701
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in part 429 from thermal efficiency and
standby loss to uniform energy factor
using the applicable mathematical
conversion factor; or
(2) Conduct testing using the test
procedure at 10 CFR 431.106, effective
July 13, 2015, along with the applicable
sampling provisions in part 429; or
(3) Where permitted, apply an
alternative efficiency determination
method (AEDM) pursuant to 10 CFR
429.70 to determine the represented
efficiency of basic models for those
categories of commercial water heaters
where the ‘‘tested basic model’’ was
tested using the test procedure at 10
CFR 431.106, effective July 13, 2015.
After July 13, 2015, all new basic
models (previously uncertified) must be
rated using the new test procedure
either by testing or by an AEDM, where
allowed. All water heaters subject to the
new test procedure adopted by the July
2014 final rule must be rated and
certified in terms of UEF. DOE will
assess compliance based upon the
energy conservation standards
expressed in terms of UEF as developed
in this rulemaking. One year after the
final rule in this rulemaking is
published, all water heaters subject to
the new UEF test procedure must be
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rated and certified based on testing
using the UEF test procedure or an
AEDM, which is based on the UEF test
procedure, where allowed. A summary
of the options and requirements at
20121
various key dates is shown in the table
below.
TABLE II.3—SUMMARY OF KEY DATES AND REQUIREMENTS
Description of date
Date
Requirements
Test Procedure Effective Date ...........................
July 13, 2015 ...................................................
Conversion Factor Effective Date ......................
Date of publication of the conversion factor
final rule in the Federal Register.
Conversion Factor Ending Date .........................
One year after publication of conversion factor
final rule.
For new basic models introduced into commerce on or after July 13, 2015, manufacturers must begin to test and represent efficiency using the UEF metric pursuant to the
UEF test procedure and sampling plan (or
an AEDM that is based on the UEF test
procedure, where allowed).
For basic models certified using the EF metric
or thermal efficiency and/or standby loss
metrics prior to July 13, 2015, manufacturers must transition all of their representations to UEF either by applying the conversion equations or by using the UEF test
procedure and sampling plan (or an AEDM
that is based on the UEF test procedure,
where allowed).
All basic models must be rated in terms of
UEF using the UEF test procedure and
sampling plan or an AEDM that is based on
the UEF test procedure, where allowed.
III. Discussion
asabaliauskas on DSK5VPTVN1PROD with NOTICES
A. Stakeholder Comments on Other
Rulemakings
During the rulemaking process to
develop the uniform efficiency
descriptor test procedure, comments
were received from stakeholders in
reference to the derivation and
applicability of the conversion factor.
DOE deferred discussion of and
response to those comments until such
time as they could be addressed in this
rulemaking.
In response to the test procedure
request for information (RFI 5) published
on January 11, 2013, DOE received
seven written comments related to the
conversion factor from the following
interested parties: AHRI, A.O. Smith
Corporation (A.O. Smith), Edison
Electric Institute (EEI), Heat Transfer
Products Inc. (HTP), the National
Renewable Energy Laboratory (NREL),
the Northwest Energy Efficiency
Alliance (NEEA), and a joint comment
on behalf of a number of environmental
groups and efficiency advocates
submitted by the American Council for
an Energy-Efficient Economy (ACEEE).6
These comments are discussed
immediately below.
5 78
FR 2340.
submitted a joint comment on behalf of
ACEEE, the Appliance Standards Awareness Project
(ASAP), the Alliance to Save Energy (ASE), the
National Consumer Law Center (NCLC), the
National Resources Defense Council (NRDC), the
Northwest Power and Conservation Council
(NPCC), and the Northeast Energy Efficiency
Partnerships (NEEP).
6 ACEEE
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NREL stated that there is not a simple
conversion factor that will work across
all systems, but suggested an
application of the Water Heater Analysis
Model (WHAM) 7 to assist DOE in
developing the conversion factor for
storage water heaters. (NREL, EERE–
2011–BT–TP–0042–0029 at p. 4) The
joint commenters supported the use of
a ‘‘good-enough’’ mathematical
conversion method to express existing
ratings in terms of the new uniform
descriptor and urged DOE to test a
sample of existing products to validate
the algorithmic conversion method.
(Joint comment, EERE–2011–BT–TP–
0042–0035 at p. 4) HTP commented that
the most exact approach would be to
conduct an empirical analysis using
curve fitting to actual test data, although
the commenter acknowledged that there
is not sufficient time for manufacturers
to obtain this information and for the
Department to then correlate and
analyze the data. (HTP, EERE–2011–BT–
TP–0042–0041 at p. 3)
Regarding the derivation of updated
energy conservation standards using the
new uniform descriptor, AHRI and A.O.
Smith commented that DOE should not
simply test multiple units to determine
an average difference between the
current and new ratings and use that
value to convert the ratings. (AHRI,
EERE–2011–BT–TP–0042–0033 at p. 4;
7 Lutz, Jim, Camilla D. Whitehead, Alex Lekov,
David Winiarski, and Greg Rosenquist, WHAM: A
Simplified Energy Consumption Equation for Water
Heaters, Proc. of 1998 ACEEE Summer Study on
Energy Efficiency in Buildings. Vol. 1. 171–83.
Print.
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Fmt 4701
Sfmt 4702
A.O. Smith, EERE–2011–BT–TP–0042–
0034 at p. 3) NEEA commented that
considering the limited laboratory
capacity to test all water heaters under
the revised method of test, DOE should
assume that all water heaters that
comply with current standards will also
comply after the implementation of the
new metrics. (NEEA, EERE–2011–BT–
TP–0042–0037 at p. 6) EEI commented
that the conversion factor should not
make currently existing standards more
stringent and should only be based on
point-of-use metrics to be consistent
with Federal law. (EEI, EERE–2011–BT–
TP–0042–0040 at p. 2)
In response to the test procedure
NOPR 8 published on November 4, 2013,
DOE received three additional written
comments related to the conversion
factor from: AHRI, Bradford White
Corporation (BWC) and a joint comment
submitted on behalf of a number of
environmental groups and efficiency
advocates by ACEEE.9 AHRI and BWC
suggested model types to test and urged
DOE to release a schedule and process
for the development of the conversion
factor as soon as possible. (AHRI, EERE–
2011–BT–TP–0042–0075 at p. 6–7;
BWC, EERE–2011–BT–TP–0042–0061 at
p. 7) AHRI suggested two categories to
be considered in the conversion factor
rulemaking: water heater type and
storage volume. BWC expanded on the
list of categories supplied by AHRI by
8 78
FR 66202.
submitted a joint comment on behalf of
ACEEE, ASAP, ASE, Consumers Union (CU), NCLC,
NRDC and NEEP.
9 ACEEE
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including considerations for input
capacity, venting options, tank
configuration, NOX emissions, and
mobile home certification. The joint
comment suggested that the sensitivity
of the energy factor to draw pattern be
investigated and that systematic
differences between ‘‘old’’ and ‘‘new’’
values should be expected for several
technologies. (Joint Comment, EERE–
2011–BT–TP–0042–0077 at p. 2)
DOE has considered these comments
fully in the development of this
proposed rule. Although discussed in
overview here, these comments are
discussed in more detail later in this
document as applicable to DOE’s
specific decisions regarding the
mathematical conversion factor. In
regards to the method of developing the
conversion factor, DOE agrees in
principle with the HTP comment that
the most exact approach would be an
empirical analysis using a curve-fitting
method and actual test data, because
such approach would account for all the
changes made in the new test
procedure, without having to make
assumptions. However, DOE notes that
the confidence in this empirical
approach is dependent upon sample
size and has considered whether the
approach can feasibly be tested and
implemented within the time
constraints set forth by AEMTCA. (The
curve-fitting method investigated is
discussed in section III.C.3.)
In addition, as suggested by NREL,
DOE investigated the use of the WHAM
model to predict water heater efficiency
under the new test procedure
parameters, and used the results in the
conversion factor analysis. The
methodology for applying WHAM and
the results are found in section III.C.2.c.
As suggested in the NOPR joint
comment, the sensitivity of the UEF to
draw pattern was investigated by
including the drawn volume in the
conversion factor calculations; this
approach is discussed further in section
III.C.
In an effort to develop a mathematical
conversion factor, DOE commissioned
testing of 72 individual water heaters
from various easily distinguishable
water-heating categories under the
updated test procedure. All of the water
heaters chosen were found using either
the Compliance Certification
Management System (CCMS) or AHRI
water heater databases, where the water
heaters included in the databases were
further distinguished based on the
suggestions made by AHRI and BWC in
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response to the November 2013 water
heaters NOPR (78 FR 66202 (Nov. 4,
2013)). The models selected for testing
and the parameters examined are
described in more detail in section III.D.
These test data were used to investigate
all of the potential conversion factor
methods described in section III.C.
DOE has also carefully considered the
comments regarding the establishment
of energy conservation standards using
the uniform efficiency descriptor metric
(i.e., UEF). Those comments are
discussed further in section III.E.3.
B. Scope
The purpose of this section is to
describe DOE’s process for categorizing
water heaters and establishing the range
of units to be considered in this
mathematical conversion factor
rulemaking. DOE seeks comment on the
scope of the conversion factor. This is
identified as issue 1 in section V.E,
‘‘Issues on Which DOE Seeks
Comment.’’
1. Test Procedure and Energy
Conservation Standards Coverage
To determine the appropriate scope of
coverage for the mathematical
conversion factor, DOE first considered
the scope of its existing test procedures
and energy conservation standards for
consumer and commercial water
heaters. Water heaters that are not
currently subject to the DOE test
procedures or standards were not
included in the scope of the conversion
factor, as they are not required to be
tested and rated for efficiency under the
DOE test method.
a. Consumer Water Heaters
Under the existing regulatory
definitions, DOE’s current consumer
water heater test procedures and energy
conservation standards are not
applicable to gas or electric water
heaters with storage tanks that are at or
above 2 gallons (7.6 L) and less than 20
gallons (76 L). In terms of the high end
of the capacity range, the current DOE
test procedure for consumer water
heaters only applies to gas-fired water
heaters with storage volumes less than
or equal to 100 gallons (380 L), electric
resistance and heat pump storage water
heaters with storage volumes less than
or equal to 120 gallons (450 L), and oilfired water heaters with storage volumes
less than or equal to 50 gallons (190 L).
10 CFR part 430, subpart B, appendix E,
sections 1.12.1, 1.12.2, and 1.12.4.
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In the July 2014 final rule, DOE
expanded the scope of the water heater
test procedure for the uniform efficiency
descriptor to include water heaters with
storage volumes between 2 and 20
gallons and up to 120 gallons. 79 FR
40542, 40547–48 (July 11, 2014).
DOE’s current consumer water heater
test procedure and energy conservation
standards are not applicable to gas-fired
instantaneous water heaters with input
capacities at or below 50,000 Btu/h or
at or above 200,000 Btu/h. 10 CFR part
430, subpart B, appendix E, section
1.7.2. In addition, the existing test
procedure and energy conservation
standards are not applicable to gas-fired
storage water heaters with input
capacities above 75,000 Btu/h, electric
storage water heaters with input ratings
above 12 kW, and oil-fired storage water
heaters with input ratings above 105,000
Btu/h, as models exceeding those limits
would not be classified as consumer
water heaters under EPCA. (42 U.S.C.
6291(27)); 10 CFR part 430, subpart B,
appendix E, sections 1.12.1, 1.12.2, and
1.12.4.
In the July 2014 final rule, DOE
designed the test procedure so it is
applicable to water heaters with any
input capacity. Therefore, the lower
limit for instantaneous water heaters no
longer applies. 79 FR 40542, 40548 (July
11, 2014).
As discussed in the July 2014 final
rule, definitions were added for
‘‘electric instantaneous water heater,’’
‘‘gas-fired heat pump water heater,’’ and
‘‘oil-fired instantaneous water heater,’’
and the July 2014 test procedure is
applicable to these types of appliances.
79 FR 40542, 40549 (July 11, 2014).
Although there is no definition for
‘‘electric instantaneous water heater’’ in
the current test procedure in 10 CFR
part 430, subpart B, Appendix E, an
energy conservation standard exists for
this type of water heater. In addition,
the current test procedure can be
applied to electric instantaneous water
heaters, and manufacturers report
energy factor ratings for these products.
For these reasons, DOE has decided to
include electric instantaneous water
heaters with rated storage volumes <2
gallons and rated inputs ≤12 kW in the
conversion factor analysis.
DOE has tentatively excluded the
consumer water heater products listed
in Table III.1 from consideration for the
mathematical conversion factor due to
the lack of an existing Federal test
procedure and rating to be converted.
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20123
TABLE III.1—CONSUMER WATER HEATERS NOT COVERED BY THE MATHEMATICAL CONVERSION FACTOR
Product class
Description of criteria for exclusion from conversion rulemaking
Gas-fired Storage .....................................................................................
Oil-fired Storage .......................................................................................
Electric Storage ........................................................................................
Tabletop ....................................................................................................
Gas-fired Instantaneous ...........................................................................
Electric Instantaneous ..............................................................................
b. Commercial Water Heaters
As stated in the July 2014 final rule,
DOE excluded from the uniform
efficiency descriptor any specific
category of water heater that does not
have a residential use, can be clearly
described, and can be effectively rated
using the current thermal efficiency and
standby loss descriptors. 79 FR 40542,
40545 (July 11, 2014). DOE determined
that certain commercial water heaters
met these criteria to be excluded from
Rated
Rated
Rated
Rated
Rated
Rated
Storage Volume ≥2 gal and <20 gal or >100 gal and ≤120 gal.
Storage Volume >50 gal.
Storage Volume ≥2 gal and <20 gal.
Storage Volume ≥2 gal and <20 gal.
Input ≤ 50,000 Btu/h; Rated Storage Volume >2 gal.
Storage Volume >2 gal.
the uniform efficiency descriptor, and
distinguished them from water heaters
that do not meet the criteria by
establishing equipment classes for
residential-duty commercial water
heaters. Commercial water heaters
meeting the definition of ‘‘residentialduty commercial water heater’’ do not
meet the criteria for exclusion, and thus,
are included in the uniform efficiency
descriptor while all other commercial
water heaters are not. DOE determined
that three criteria would be used to
distinguish residential-duty commercial
water heaters from other commercial
water heaters (79 FR 40542, 40547 (July
11, 2014)):
(1) For models requiring electricity,
uses single-phase external power
supply;
(2) Is not designed to provide outlet
hot water at temperatures greater than
180 °F; and
(3) Is not excluded by the limitations
regarding rated input and storage
volume presented in Table III.2.
TABLE III.2—CAPACITY LIMITATIONS FOR DEFINING COMMERCIAL WATER HEATERS WITHOUT RESIDENTIAL APPLICATIONS
(i.e., NON-RESIDENTIAL-DUTY)
Water heater type
Indicator of non-residential application
Gas-fired Storage .....................................................................................
Oil-fired Storage .......................................................................................
Electric Storage ........................................................................................
Heat Pump with Storage ..........................................................................
Rated input >105 kBtu/h; Rated storage volume >120 gallons.
Rated input >140 kBtu/h; Rated storage volume >120 gallons.
Rated input >12 kW; Rated storage volume >120 gallons.
Rated input >15 kW; Rated current >24 A at a rated voltage of not
greater than 250 V; Rated storage volume >120 gallons.
Rated input >200 kBtu/h; Rated storage volume >2 gallons.
Rated input >58.6 kW; Rated storage volume >2 gallons.
Rated input >210 kBtu/h; Rated storage volume >2 gallons.
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Gas-fired Instantaneous ...........................................................................
Electric Instantaneous ..............................................................................
Oil-fired Instantaneous .............................................................................
DOE did not include commercial
water-heating equipment that does not
meet the definition of a ‘‘residentialduty commercial water heater’’ in its
consideration of the mathematical
conversion factor, as the equipment is
not subject to the uniform efficiency
descriptor test procedure. Additionally,
DOE notes that there are no electric
storage water heaters that would be
considered to be residential-duty
commercial since the qualifications
shown in Table II.2 would place an
electric storage water heater in the
consumer category. Since there are no
such units, and could not be such units
under the applicable definition, a
conversion is unnecessary. DOE is,
therefore, not proposing a conversion
factor for residential-duty electric
storage water heaters. DOE also notes
that a water heater that meets the
definition of a consumer electric storage
water heater must be tested and rated as
a consumer electric storage water heater
even if it is marketed as part of a
commercial product line.
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As stated in the July 2014 final rule,
DOE has determined that certain
commercial equipment including
unfired storage tanks, add-on heat pump
water heaters, and hot water supply
boilers are not appropriately rated using
the uniform descriptor applicable to
other water heaters, and, thus, will
continue to be rated using the existing
metrics. 79 FR 40542, 40547.
Electric instantaneous water heaters
are currently subject to the commercial
water heating equipment test
procedures but do not have an
associated energy conservation
standard. 10 CFR 431.106; 10 CFR
431.110. Because there is no commercial
energy conservation standard for
electric instantaneous water heaters, a
conversion to the UEF cannot be made.
2. Units on the Market
As stated in section II, DOE undertook
an investigation into the water-heating
units on the market at the time of the
publication of the final rule establishing
the UEF test procedure. The AHRI
commercial water heater database along
with the CCMS consumer water heater
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database were examined to select
representative units for testing and
analysis.
DOE’s analysis focused on the models
that meet the energy conservation
standards contained in the April 2010
final rule, which will require
compliance on April 16, 2015. The
storage volume divisions at 55 gallons
in the gas-fired and electric storage
product classes, as established in the
April 16, 2010 final rule, represent a
divide in technology. For gas-fired
storage units above 55 gallons
manufactured on and after April 16,
2015, the energy conservation standard
will be high enough that current designs
can only achieve the required efficiency
through the use of condensing
technology.10 For electric storage units
with storage volumes above 55 gallons,
only heat pump water heaters currently
10 In a condensing water heater, the combustion
gases are cooled such that the temperature is
reduced below the dew point and condensation
occurs, allowing the latent heat of vaporization to
be captured and improving the efficiency of the
heat exchange between the combustion gases and
the water.
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have the ability to reach the April 16,
2015 energy conservation standard
levels. While the UEF test procedure
will apply to both electric and gas units
in this range, DOE found that for gasfired storage water heaters, there are
currently no consumer water heaters
above 55 gallons that would be
compliant with the updated standard, so
no units were tested for development of
a conversion factor. For electric storage
water heaters, heat pump water heaters
meet or exceed the amended energy
conservation standards and, thus, were
candidates for inclusion in the test plan
for the conversion factor. There are no
oil-fired instantaneous or oil-fired
storage water heaters above 50 gallons
available on the market.
In reviewing the commercial water
heating market, DOE found that
commercial oil-fired instantaneous
water heaters are available on the
market but do not meet the definition of
‘‘residential-duty commercial water
heater,’’ as they have storage volumes
greater than 2 gallons. DOE found that
all commercial gas-fired instantaneous
units exceeded the maximum delivery
temperature of 180 °F for residentialduty commercial water heaters, and,
thus, would be regulated using the
existing thermal efficiency and standby
loss metrics. DOE also found that
commercial electric instantaneous units
which meet the definition of
‘‘residential-duty commercial water
heater’’ exist, however, as stated in
section III.B.1.b, no energy conservation
standard exists for these units; therefore
a conversion factor was not developed.
Consequently, none of the commercial
water heaters identified above could be
tested or examined for use in this
rulemaking. In addition, a conversion
factor for these water heaters is not
needed because there are no units in
existence with efficiency ratings that
can be converted. However, because a
manufacturer may want to design and
produce products in these equipment
classes in the future, DOE must
establish energy conservation standards
in terms of the UEF metric. Accordingly,
DOE used information gained from
other product classes to establish these
energy conservation standards, as
discussed in section III.E.
C. Potential Approaches for Developing
Conversions
1. Background Regarding Changes to
Existing Test Procedures
a. Consumer Water Heater Test
Procedures
Both the current test procedure and
the uniform efficiency descriptor test
procedure consist of a delivery capacity
test and a 24-hour simulated-use test.
The delivery capacity tests for storage
and instantaneous water heaters are the
first-hour rating and maximum GPM
tests, respectively. These tests are
largely unchanged from the current to
the new test procedure, except for
modifications to account for the
decrease in delivered water temperature
from a nominal value of 135 °F to 125
°F. The results of those tests, however,
have implications on the 24-hour
simulated-use test under the new test
procedure that are absent under the
current test procedure.
In the current test procedure, the
delivery capacity has no effect on the
24-hour simulated-use test, which
consists of six hot water draws, of
equivalent volumes, at the start of the
test and each of the first five subsequent
hours. The water heater is then in
standby mode for the remainder of the
test. In the July 2014 final rule,
however, the delivery capacity
determines the draw pattern for the 24hour simulated-use test. According to
the new test procedure, a water heater’s
delivery capacity can be categorized as
either very small, low, medium, or high;
these usages are shown below in Table
III.3. 79 FR 40542, 40572 (July 11, 2014).
These usage categories have an
associated draw pattern prescribed to
them during the 24-hour simulated-use.
Depending on the delivery capacity
associated with a water heater, between
9 and 14 hot water draws of various
volumes and flow rates are required.
TABLE III.3—DELIVERY CAPACITY CATEGORIZATION CRITERIA
First-Hour Rating, gal
Draw Pattern
≥
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Very Small .............................
Low ........................................
Medium ..................................
High .......................................
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0
18
51
75
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<
In the existing DOE consumer water
heater test procedure, a temperature of
135 °F ± 5 °F is used for the set-point
temperature for storage water heaters
(measured as the mean tank
temperature) and the delivery
temperature for instantaneous water
heaters. In the uniform efficiency
descriptor test procedure set forth in the
July 2014 final rule, a temperature of
125 °F ± 5 °F is used for the set-point
temperature for storage water heaters
(measured as the delivery temperature)
and the delivery temperature of
instantaneous water heaters. 79 FR
40542, 40554 (July 11, 2014).
VerDate Sep<11>2014
Maximum GPM, gpm
18 ..........................................
51 ..........................................
75 ..........................................
No upper limit .......................
<
0
1.7
2.8
4
b. Commercial Water Heater Test
Procedure
The current test procedure for rating
commercial water heaters consists of a
steady-state test to determine thermal
efficiency and a test lasting between 24
and 48 hours to measure the standby
loss. 77 FR 28996 (May 16, 2012); 10
CFR 431.106. For electric resistance
water heaters, the thermal efficiency is
assigned a value of 98 percent in lieu of
testing. The set-point temperature of the
water heater is 140 °F ± 5 °F, and the
unit sits in an environment with an
ambient temperature of 75 °F ± 10 °F.
Water is supplied to the water heater at
a temperature of 70 °F ± 2 °F.
Instantaneous water heaters are not
required to undergo a standby loss test.
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1.7 .........................................
2.8 .........................................
4 ............................................
No upper limit .......................
Drawn
Volume, gal
10
38
55
84
Under the uniform efficiency
descriptor test procedure, commercial
water heaters falling under the
‘‘residential-duty’’ category will now be
subject to the first-hour rating or
maximum GPM test and simulated-use
tests specified in the previous section
(III.C.1.a), with the same set-point
temperature, ambient temperature, and
inlet water temperature as is applied to
consumer water heaters.
2. Analytical Methods
For converting existing ratings to
ratings under the uniform efficiency
descriptor test method, DOE considered
equations based on a water heater’s
physical characteristics; these
approaches will be termed analytical
methods. The sections below describe
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20125
potential analytical methods for the
three key metrics that result from the
uniform efficiency descriptor test
method: (1) The maximum GPM; (2) the
first-hour rating; and (3) the UEF. In the
discussion immediately below, DOE
introduces key factors that it expects
will change ratings from the existing
consumer and commercial water heater
test procedures to the new uniform
efficiency descriptor test procedure.
a. Maximum GPM
For flow-activated water heaters, the
delivery capacity is determined by the
10-minute maximum GPM rating test.
During this test, the water heater runs at
maximum firing rate to raise the
temperature from its nominal value of
58 °F to the prescribed delivery
temperature. This flow rate is
determined by the following equation:
˙
where V is the volumetric flow rate of
water, Q is the firing rate, hr is the
recovery efficiency, r is the density of
the delivered water, cp is the specific
heat of the delivered water, Tdel is the
delivered water temperature, and Tin is
the inlet water temperature. If it is
assumed that the firing rate and
recovery efficiency are the same with
water delivered at 125 °F and 135 °F,
then the ratio of the maximum GPM at
125 °F versus that at 135 °F is
determined by the following equation:
Therefore, an analytical conversion
from the existing maximum GPM rating
˙
(Vex) for consumer water heaters to the
rating under the test conditions in the
uniform efficiency descriptor test
˙
method (VUED) is:
˙ UED = 1.147Vex
˙
V
As discussed in detail in section
III.E.2, tests on flow-activated water
heaters showed a change in maximum
GPM rating under the uniform
efficiency descriptor test method that
correlated well with the above equation.
draw, and the test is concluded upon
termination of that draw.
In the uniform efficiency descriptor
test procedure, the primary change that
will affect the first-hour rating is the
shift from a nominal delivery
temperature of 135 °F to 125 °F and the
accompanying adjustment to the draw
termination criterion to a decrease in
delivered water temperature from 25 °F
in the current consumer water heater
test method to 15 °F in the uniform
efficiency descriptor test method.
Because the initial set-point temperature
is reduced in the uniform efficiency
descriptor as compared to the existing
consumer water heater test procedure,
less stored thermal energy will be
available at the start of the test.
However, this effect is countered
because the lower set-point temperature
allows the water heater to recover
quicker (as the water only needs to be
heated to a 15 °F temperature rise rather
than a 25 °F temperature rise), thereby
allowing subsequent draws to start
sooner than they would under the
current test procedure. Thus, due to
these offsetting effects, DOE has
observed through testing that sometimes
the first-hour rating is increased when
tested under the uniform efficiency
descriptor, and sometimes the rating is
decreased. DOE is not aware of any
analytical models that would
mathematically represent this behavior,
so it has chosen not to pursue such an
approach for converting existing firsthour ratings to first-hour ratings under
the uniform efficiency descriptor.
Rather, as discussed in section III.C.3,
DOE chose an approach based on an
empirical regression for converting the
first-hour ratings.
Likewise, DOE is not aware of any
analytical method that will convert
rated values of thermal efficiency and
standby loss for residential-duty
commercial storage water heaters to a
first-hour rating. Therefore, DOE chose
an approach based on empirical
regression for converting existing ratings
of residential-duty commercial water
heaters to first-hour ratings.
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i. Consumer Storage Water Heaters
A simple theoretical model for
determining the energy consumption of
a storage-type water heater based on key
test parameters, termed the Water
Heater Analysis Model (WHAM), was
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For water heaters that have a heat
source controlled by means other than
sensing flow (e.g., thermostaticallycontrolled), the delivery capacity is
determined through a first-hour rating
test. During this test, the water heater
begins in its fully heated state, and
water is drawn from it at a specified
flow rate until the temperature of the
delivered water drops a specified
amount. The water heater is then
allowed to recover, and subsequent
draws are initiated when the controller
acts to reduce the heat input to
particular burners or heating elements
specified in the test procedure. These
subsequent draws are terminated based
on the same criterion that is used for the
first draw, namely that the outlet water
temperature drops a set amount of
degrees from its maximum value during
that draw. When the test reaches a
duration of one hour from the start of
the first draw, the test concludes after
the draw termination criterion is
reached for the draw taking place at one
hour from the start of the test. If no draw
is occurring at the one hour duration, a
draw is initiated and terminated when
the outlet water temperature reaches the
termination temperature of the previous
A number of changes to the 24-hour
simulated-use test will alter the water
heater energy efficiency ratings from the
existing water heater test procedures as
compared to the ratings obtained under
the uniform efficiency descriptor test
method. Among the key changes that are
expected to alter the efficiency metric
for consumer water heaters are: (1) A
different volume of water withdrawn
per test; (2) a change in the draw pattern
(i.e., number of draws, flow rates during
draws, timing of draws) applied during
the test; (3) reduction of the test
temperature from an average stored
temperature of 135 °F to a delivered
water temperature of 125 °F; and (4)
removal of the stipulation to normalize
the energy consumption to maintain a
prescribed average water temperature
within the storage tank. Residentialduty commercial water heaters will see
a change from the thermal efficiency
and standby loss metrics currently in
place to the UEF, which consists of an
entirely new approach for rating
efficiency.
EP14AP15.006</GPH>
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b. First-Hour Rating
c. Uniform Energy Factor
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during the same draw profile of between
3 and 13 percent, with an average of 8
percent. Data collected on fossil-fuelfired water heaters show negligible
dependency of the recovery efficiency
on the prescribed tank temperature. The
UA value may change slightly based on
higher heat transfer coefficients at
higher temperatures or changes in the
thermal conductivity of insulating
materials at higher temperatures. Data
collected by DOE suggest that the UA
value decreases 7 percent from 135 °F
to 125 °F.
For an initial estimate, DOE
considered the situation where the UA
and recovery efficiency do not change
with temperature. The equations above
can estimate the effects of two key
factors that have changed in the test
procedure, namely the volume drawn
per day and the delivery temperature.
As more water is delivered, the fraction
of energy required to make up the
standby losses compared to the overall
energy required by the water heater is
diminished, thereby increasing the
fraction of energy going towards hot
delivered water and increasing the
efficiency. The change in set-point
temperature appears to have less of an
effect on water heater efficiency, since
two competing factors are at play. With
a lower stored water temperature, the
standby losses are decreased, thereby
increasing the overall efficiency of the
water heater. The lower delivery
temperature, however, means that less
energy is delivered per gallon, so the
energy delivered for a given volume
delivered per day is less than that when
the water is delivered at 135 °F, thereby
decreasing the efficiency of the water
heater.
As noted, direct use of this model
may not properly account for changes to
the recovery efficiency, UA value, or
normalization procedure for standby
heat loss. Therefore, DOE has chosen a
two-step process to convert the existing
Energy Factor ratings for consumer
storage water heaters to the UEF. First,
using the equations and assumptions
described above, a prediction of the
11 Lutz, Jim, Camilla Dunham Whitehead, Alex
Lekov, David Winiarski, and Greg Rosenquist.
‘‘WHAM: A Simplified Energy Consumption
Equation for Water Heaters’’ In Proceedings of the
1998 ACEEE Summer Study on Energy Efficiency in
Buildings (1998) (Available at: https://
cgec.ucdavis.edu/ACEEE/1998/pdffiles/papers/
0114.pdf) (Last accessed October 1, 2014).
12 Sparn, B., K. Hudon, and D. Christensen,
Laboratory Performance Evaluation of Residential
Integrated Heat Pump Water Heaters. National
Renewable Energy Laboratory (September 2011)
(Available at: https://www.nrel.gov/docs/fy11osti/
52635.pdf) (Last accessed October 1, 2014).
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Currently, directories of water heater
ratings provide the Eff (i.e., Energy
Factor), P, and hr. Since the EF testing
entails a prescribed Tdel (135 °F), Tin (58
°F), Ttank (135 °F), Tamb (67.5 °F), and V
(64.3 gallons), the two equations can be
solved for the two remaining unknowns,
Q and UA. The exception to this
approach is heat pump water heaters.
For these units, the reported recovery
efficiency (hr) is that of the resistance
element inside the water heater. Since it
is expected that the heat pump unit
would provide the majority of the
heating during the simulated-use test as
opposed to the resistance element, the
required data to use the WHAM model
for heat pump water heaters is not
readily available in publicly accessible
directories. For these units, DOE
proposes to base the conversion
equation purely on experimental data.
After the equations are solved to
determine UA, if one assumes that the
UA and hr do not change under the new
test approach, then the two equations
can be solved again (this time inserting
the UA value obtained from solving the
previous set of equations) to determine
the values for Q and Eff (i.e., UEF) under
the uniform efficiency descriptor test
method using the prescribed values for
the uniform efficiency descriptor test
procedure of Tdel (125 °F), Tin (58 °F),
Ttank (125 °F), Tamb (67.5 °F), and V
(varies depending upon draw pattern).
This formulation entails a number of
assumptions. A major assumption is
that the average tank temperature is
approximately equal to the delivered
water temperature. As previously noted,
the new procedure does not normalize
the average stored water temperature to
a prescribed value, so this estimate may
not be completely accurate. Some water
heaters have demonstrated that average
tank temperature is below the typical
delivered temperature because of
stratification. This effect is believed to
be most pronounced with condensing
water heaters. Other water heaters show
some stratification, but the average
water temperature within the tank is
typically closer to the delivered water
temperature. Another assumption in
this formulation is that the recovery
efficiency and UA values do not change
when the water heater stores water for
delivery at 135 °F compared to storing
it at 125 °F. While electric resistance
water heaters have a prescribed recovery
efficiency of 98 percent, other
technologies may see changes in the
recovery efficiency as the temperature
drops. For example, the study by Sparn
et al. shows plots of the Coefficient of
Performance (COP), which is one aspect
of the recovery efficiency, for heat pump
water heaters.12 Their data suggest an
increase in COP of approximately 15
percent with the average tank
temperature at 125 °F compared to 135
°F. Data obtained by DOE indicate an
increase in recovery efficiency obtained
EP14AP15.009</GPH>
period is determined using the
following equation:
where r is the density of water, cp is the
specific heat of water, hr is the recovery
efficiency, V is the volume of water
delivered per day, UA is the heat loss
factor, Ttank is the average temperature of
the water stored within the tank of a
storage water heater, P is the input
power to the water heater in Btu/h, Tamb
is the average ambient temperature
during the test, and 24 is the number of
hours in the test. This equation
considers the energy required to heat
the water that is delivered by the water
heater from the inlet water temperature
up to the delivery temperature and the
energy required to make up the heat lost
from the water heater to the surrounding
environment. The time over which this
standby energy loss is determined is
corrected by the term with the power in
the denominator to account for the fact
that hr, as calculated in the test,
accounts for standby energy loss during
periods when heat input to the water is
activated.
This calculated energy can then be
used to estimate the daily efficiency, Eff,
under a given daily water demand (e.g.,
that required during the current EF test
or that required during the UEF test):
asabaliauskas on DSK5VPTVN1PROD with NOTICES
presented by Lutz et al.11 The equation
for the energy input (Q) over a 24-hour
20127
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
efficiency given by WHAM is
determined, termed UEFWHAM. This
value is then considered as part of a
regression analysis (see section III.C.3)
to obtain a relationship that will convert
from EF to UEF. DOE believes that the
use of WHAM will capture the primary
effects of changes in the volume of
water delivered per day along with
changes in the set-point temperature.
Regression with experimental data will
equation incorporates the equations and
assumptions presented above, where hr
and EF are the recovery efficiency and
energy factor, respectively, based on the
current DOE test procedure, and P is the
nameplate input rate in Btu/h. As
shown in Table III.4, constants ‘‘a,’’ ‘‘b,’’
‘‘c,’’ and ‘‘d’’ are dependent on the
volume of water being drawn.
then capture the effects that may not be
fully accounted for by WHAM, such as
differences in the UA value, recovery
efficiency, and the change to the
normalization calculation procedure for
standby heat loss.
To establish a clear method of
applying the analytical model, the
WHAM-based UEF equation and Table
III.4, comprising the coefficients based
on draw bin, are presented below. This
TABLE III.4—COEFFICIENTS FOR WHAM-BASED UEF CONVERSION FACTOR
Very Small .......................................................................................................
Low ..................................................................................................................
Medium ............................................................................................................
High ..................................................................................................................
ii. Consumer Instantaneous Water
Heaters
asabaliauskas on DSK5VPTVN1PROD with NOTICES
WHAM is not directly applicable to
instantaneous water heaters because it
assumes that the water heater loses heat
at a constant rate throughout the day
when the heating element is not
energized. For instantaneous water
heaters, this modeling approach is
inappropriate since the unit does not
store water at an elevated temperature
where LF is a loss factor related to the
amount of energy stored in the materials
of the water heater and N* is the
number of draws from which heat loss
occurs to the environment. LF is
approximately equal to the mass of the
material within the water heater times
its heat capacity. N* is not simply the
number of draws during the day, since
some draws may occur close together
and do not result in total energy loss. To
determine the fraction of energy from a
draw that is lost, DOE examined data
from testing that suggested that most
heat is lost from tankless water heaters
after about one hour. Using this value,
DOE scaled the energy loss for a draw
by the length of the standby time
following the draw. For example, a draw
followed by over one hour of standby
time would contribute a value of 1 to N*
for that test. A draw followed by 30
minutes of standby time prior to the
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108233096990
throughout the day, rather heating water
as it flows through the unit.
Instantaneous water heaters instead
experience a separate type of heat loss
to the surroundings that sometimes
result in Energy Factors that are below
the steady-state thermal efficiency. This
loss occurs when heat that is present in
the water heater at the end of a draw
dissipates to the ambient. If a draw is
not initiated shortly after the end of a
draw, then most of this heat is lost. If,
next draw would contribute a value of
(30 min)/(60 min) = 0.5 to N*.
Contributions from each draw in a test
pattern are added to obtain a value for
N* for each draw pattern. For the
existing DOE consumer water heater
test, N* is 5.64, as the standby time
following each draw is slightly under 60
minutes. The values for N* for all draw
patterns are provided in Table III.5.
TABLE III.5—ESTIMATE OF NUMBER OF
DRAWS FROM WHICH ALL ENERGY
FROM WATER HEATER IS LOST TO
SURROUNDINGS
Draw pattern
N*
Existing Consumer Water Heater
Draw Pattern .................................
Very-Small-Use .................................
Low-Use ............................................
Medium-Use .....................................
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c
5.64
4.36
6.72
7.45
8930623
33936368
49118427
75017235
d
15125743368
57477824799
83191588525
127056244293
however, a subsequent draw starts
shortly after a previous draw, some of
that heat is captured in the hot water
that is delivered.
DOE attempted to capture these
effects in a modified equation that
separately accounts for energy
consumption that goes towards
supplying heat to the delivered water
and energy consumption that goes
towards heating up the materials
making up the water heater:
TABLE III.5—ESTIMATE OF NUMBER OF
DRAWS FROM WHICH ALL ENERGY
FROM WATER HEATER IS LOST TO
SURROUNDINGS—Continued
Draw pattern
High-Use ...........................................
N*
7.53
DOE attempted this approach by
obtaining an estimate of LF from data
obtained during testing of 17 gas
instantaneous water heaters according
to the current simulated-use test. (LF
could theoretically be determined for
each unit, but some test results showed
a recovery efficiency equal to EF, which
would mathematically lead to an
infinite value of LF). A regression of the
energy consumption data during these
tests with the quantity multiplying LF
in the previous model equation resulted
in a value of LF of 0.679 Btu/°F. Using
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Draw bin
20128
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
DOE seeks comments on the use of
analytical methods to convert existing
metrics to the ones described in the July
2014 test procedure final rule. This is
identified as issue 2 in section V.E,
‘‘Issues on Which DOE Seeks
Comment.’’
These equations can be combined to
yield the following equation for
converting Et and SL to UEF using the
coefficient C1, which is dependent upon
the draw pattern applied during the
UEF test, as provided in Table III.6.
TABLE III.6—COEFFICIENT FOR CONVERSION OF COMMERCIAL WATER
HEATER RATINGS TO UEF
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Draw pattern
Very Small ............................
Low .......................................
Medium .................................
High ......................................
C1
3.575
9.408
6.500
4.256
×
×
×
×
10¥3
10¥4
10¥4
10¥4
As was done with consumer water
heaters, DOE decided to account for
unforeseen effects observed during
testing by combining this analytical
prediction with a regression of the
predicted values of UEF to the measured
UEF.
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3. Empirical Regression
An alternative to the analytical
approaches described in section III.C.2
is to develop empirical equations from
measured metrics under the uniform
efficiency descriptor test procedure to
those obtained using the existing
consumer and commercial water heater
test procedures. This approach has the
benefit of capturing the effects of factors
that are not addressed in analytical
models. The drawbacks of this approach
are that it is susceptible to measurement
errors and that it may not be easily
extended to water heaters that were not
part of the test program.
To derive the conversion factors from
an empirical regression, DOE first used
a step regression method. The step
regression method produces a linear
equation which uses a set of observed
independent variables, such as storage
volume, input rate, delivery capacity,
recovery efficiency, energy factor,
thermal efficiency, or standby loss, and
seeks to mathematically derive an
equation using these variables to relate
to a set of observed dependent variables,
such as new delivery capacity (under
the updated test method) and UEF. The
step regression method systematically
recombines the set of independent
variables to produce an equation for
each possible set. Each set’s equation is
compared to the others and the equation
with the best fit is chosen. This
approach eliminates factors that are not
significant in converting existing
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iii. Residential-Duty Commercial Water
Heaters
DOE investigated a modified version
of WHAM for converting the thermal
efficiency and standby loss metrics for
residential-duty commercial storage
water heaters to UEF. The AHRI
certification directory includes the
thermal efficiency (Et) and standby loss
(SL). The equation below estimates the
energy consumption of a water heater
based on these efficiency metrics:
metrics to the new metrics. DOE also
considered simpler regression forms to
reduce confusion in converting from old
metrics to new metrics and to ensure
that the regressions were applicable
over the broad range of water heaters
available on the market. In these
circumstances, DOE examined the
deviations between measured values
and predicted values from the
correction equations. When those
deviations were comparable, DOE opted
for simplified models that would be
expected to capture the major
phenomena that would affect the new
metrics. The regression tool found in the
Analysis ToolPak of Microsoft Excel
(2010) was used to calculate the
equation for each set of independent
variables.
As noted previously, because DOE has
tentatively concluded that an empirical
regression methodology would be more
accurate than the analytical method
described in section III.C.2 for
determining first-hour rating for storage
water heaters, DOE has proposed
conversion factors for those metrics and
product types based on the use of the
empirical regression methodology. DOE
seeks comment on the use of the
regression method for the conversion
factor analysis. This is identified as
issue 3 in section V.E, ‘‘Issues on Which
DOE Seeks Comment.’’
D. Testing Conducted for the
Mathematical Conversion
1. Consumer Water Heater Testing
For its analysis of a mathematical
conversion factor between the existing
efficiency metrics and the uniform
efficiency descriptor, DOE tested 43
consumer storage water heaters to both
the existing and updated test
procedures. Table III.7 and Table III.8
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where 70 represents the nominal
temperature difference in degrees
Fahrenheit between the tank and
ambient during the standby loss test. By
assuming that Ttank equals Tdel, all
variables in the equation above are
known, since Et and SL can be obtained
from current ratings and all other
variables are specified in the UEF test
procedure for a given projected firsthour rating. The equation above can be
used in combination with the one below
to estimate the UEF for residential-duty
storage water heaters (UEFrd):
unforeseen issues. Details on this
approach are provided in section III.C.3.
EP14AP15.013</GPH>
UEF—first using the equations and
assumptions described above to obtain
an analytical prediction of UEF, then
using a regression analysis to obtain a
relationship that will convert from EF to
UEF. Based on these results, DOE has
chosen to use the analytical model plus
a regression approach for converting EFs
for consumer instantaneous water
heaters to UEF. DOE has tentatively
concluded that the assumptions made in
the analytical model capture some key
operating characteristics of the
instantaneous units, and the further step
to use measured data captures
EP14AP15.012</GPH>
this value to then estimate the energy
consumption during the new simulateduse test resulted in predictions of the
UEF. This approach resulted in a root
mean squared error between predicted
values and measured values of 0.027.
Alternatively, a set of regressions,
based solely on test data, were
examined to determine the impact of
other factors as discussed in section
III.C.3. The best regressions resulted in
a mean squared error of 0.032.
As discussed for consumer storage
water heaters in section III.C.2.c.i, DOE
also considered a two-step process to
convert the existing EF ratings to the
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
below summarize the units that have
been tested. Table III.7 summarizes the
units that have been tested according to
heating type. Table III.8 provides an
estimate of the distribution of those
units across draw pattern categories by
using their first-hour ratings under the
current test (although it is
acknowledged that the applied draw
pattern for a particular water heater
could change under the new first-hour
rating test).
TABLE III.7—CONSUMER STORAGE
WATER HEATER TEST DISTRIBUTION
BY PRODUCT TYPE
Product type
Number of
units tested
Gas-fired ...............................
Oil-fired .................................
Electric ..................................
Heat Pump ............................
Tabletop ................................
Number of
units tested
Very Small ** .........................
Low .......................................
Medium .................................
High ......................................
0
3
27
13
* The draw pattern shown is based on the
current rated values; actual draw patterns are
dependent upon amended test procedure firsthour rating discussed in section III.C.1.
** No very small consumer storage water
heaters covered under the existing test procedure were found on the market.
asabaliauskas on DSK5VPTVN1PROD with NOTICES
DOE also tested 22 consumer
instantaneous water heaters to develop
the mathematical conversion for these
products. Table III.9 below summarizes
the units that have been tested. Table
III.10 provides an estimate of the
distribution of those units across draw
patterns by using their maximum GPM
ratings under the current test (although
it is acknowledged that the applied
draw pattern for a particular water
heater could change under the new
maximum GPM test).
TABLE III.9—CONSUMER INSTANTANEOUS WATER HEATER TEST DISTRIBUTION BY PRODUCT TYPE
Product type
Gas-fired * .............................
Oil-fired ** ..............................
VerDate Sep<11>2014
19:01 Apr 13, 2015
Continued
Number of
units tested
Product type
Electric ..................................
5
* Gas-fired water heaters include both natural gas and propane water heaters, as well
as water heaters capable of using either natural gas or propane. DOE tested 10 natural
gas water heaters, 1 propane water heaters,
and 6 water heaters capable of using either
natural gas or propane. Water heaters capable
of using either fuel were tested with natural
gas.
** No oil-fired consumer instantaneous water
heaters were found to be on the market.
TABLE III.10—CONSUMER INSTANTANEOUS WATER HEATER TEST DISTRIBUTION BY DRAW PATTERN
22
2
11
6
2
TABLE III.8—CONSUMER STORAGE
WATER HEATER TEST DISTRIBUTION
BY DRAW PATTERN
Draw pattern *
TABLE III.9—CONSUMER INSTANTANEOUS WATER HEATER TEST DISTRIBUTION BY PRODUCT TYPE—
Number of
units tested
Draw pattern *
Very Small ............................
Low .......................................
Medium .................................
High ......................................
5
1
7
9
* Draw pattern profiles are based on the
rated values; actual draw patterns are dependent upon tested value discussed in section
III.C.1.
2. Residential-Duty Commercial Water
Heater Testing
DOE tested 7 residential-duty
commercial storage water heaters to
develop the mathematical conversion
for this equipment. Table III.11
summarizes the units that have been
tested. A table showing the distribution
of draw pattern within the residentialduty commercial water heater test list is
not available, because commercial water
heaters currently do not have first-hour
ratings.
TABLE III.11—RESIDENTIAL-DUTY
COMMERCIAL
STORAGE
WATER
HEATER TEST DISTRIBUTION BY
PRODUCT TYPE
Number of
units tested
Product type *
Gas-fired ...............................
Oil-fired ** ..............................
7
0
* Heat pump and tabletop water heaters
were not found on the market and, therefore,
were not tested.
** One oil-fired unit failed during testing.
As discussed in section III.B.2, DOE
did not analyze a mathematical
Number of
conversion for residential-duty
units tested
commercial electric storage water
17 heaters or residential-duty commercial
0 instantaneous water heaters.
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20129
E. Testing Results and Analysis of Test
Data
1. Impact of Certain Water Heater
Attributes on Efficiency Ratings
After conducting testing on all of the
selected water heaters according to both
the existing test procedures and the
uniform efficiency descriptor test
procedure, DOE examined how
particular attributes of water heaters
might affect the conversion factors and
investigated the approaches discussed
in section III.C for obtaining conversion
factors. The goal of this analysis was to
determine whether or not particular
attributes necessitated separate
conversion equations. Separate
conversions were created for subsets of
the tested units based on water heater
attributes such as NOX emission level,
short or tall configuration, vent type,
standing pilot or electric ignition, if
condensing or heat pump technology is
used, and if the unit is tabletop.
Additionally, conversion equations
were also generated based on the full set
of water heaters. To determine whether
it was necessary to develop separate
conversion factors for a particular
attribute, the root-mean-square (RMS) of
the difference between the measured
values and the values obtained through
various conversion methods was
compared. The conversion approach
with the lowest cumulative RMS value
for a particular fuel type was considered
to be the best candidate for the
conversion equation.
The three levels of NOX emissions
currently available in water heaters on
the market include standard (greater
than or equal to 40 nanograms per joule
(ng/J)), low (less than 40 ng/J and greater
than or equal to 10 ng/J for storage water
heaters and greater than or equal to 14
ng/J for instantaneous water heaters)
and ultra-low (less than 10 ng/J for
storage water heaters and less than 14
ng/J for instantaneous water heaters).
Most units that are short or tall have
been labeled as such by the
manufacturer; however, some units do
not have this designation. DOE has
found that some units labeled as small
are actually taller than units labeled as
tall. DOE is interested in how
manufacturers determine whether a unit
is short or tall. This is identified as issue
4 in section V.E, ‘‘Issues on Which DOE
Seeks Comment.’’
The four venting configurations
currently available in water heaters on
the market include atmospheric, direct,
power, and power-direct. Atmospheric
and power vent units intake air from the
area surrounding the water heater, while
direct and power-direct vents intake air
from outdoors. Atmospheric and direct
E:\FR\FM\14APP2.SGM
14APP2
20130
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
vent units use natural convection to
circulate combustion air, while power
and power-direct vents use some
additional method to force circulation of
combustion air. Concentric inlet and
outlet piping is a unique configuration
that can be used in directly venting
water heaters to preheat incoming air
using exhaust gas. For these tests,
concentric inlet and outlet piping was
not used; inlet air for the direct and
power-direct vent units was delivered to
the water heater in separate pipes from
that used for exhaust. As these tests
were conducted under identical
controlled conditions, DOE determined
that there is very little difference
between atmospheric and direct vent
water heaters and also between power
and power-direct vent. For these reasons
DOE has grouped atmospheric and
direct into the atmospheric
configuration and power and powerdirect into the power configuration.
As an example of the process that was
taken to examine the effect of these
factors, Table III.12 shows the
cumulative RMS values for the firsthour rating conversions for consumer
storage water heaters. The rows in the
table indicate how the conversion
equations were separated out, and the
columns provide the RMS for each class
of consumer storage water heaters. For
gas water heaters, these values show
that the conversion approach that
differentiates between condensing or
non-condensing technology and
between NOX levels appears to provide
the best approach considering its low
RMS values. No other factors (e.g., short
vs. tall, vent type, pilot type) were
shown to have any significance on the
effectiveness of the conversion factor.
For oil-fired water heaters and electric
water heaters, the lowest RMS
deviations occurred when all units of
that fuel type were considered,
indicating that separating the
conversion equations by tank shape was
not necessary. The findings presented
here for first-hour rating conversions are
consistent with those for UEF. From
these results, DOE proposes to develop
conversion equations for consumer
storage water heaters based on fuel type,
with the gas units being further
differentiated by whether or not they are
condensing units and by their NOx
emissions level ratings.
For consumer instantaneous water
heaters and residential-duty commercial
water heaters, DOE found no
dependence on factors such as
condensing operation or vent type.
Conversion factors for these classes of
water heaters are, thus, based simply on
fuel type.
TABLE III.12—FIRST-HOUR RATING RMS VALUES BY WATER HEATER ATTRIBUTE FOR CONSUMER WATER HEATERS
Gas-fired
All Units (All fuel types) ....................................................................................................................
All Units Short or Tall .......................................................................................................................
Fuel Type (Gas, Oil or Electric) .......................................................................................................
6.99
6.87
7.16
Fuel Type Short or Tall ....................................................................................................................
6.91
Fossil Fuel (Gas and Oil) .................................................................................................................
Fossil Fuel Short or Tall ...................................................................................................................
Condensing or Non-Condensing ......................................................................................................
NOX Type (Standard, Low or Ultra Low) .........................................................................................
Vent Type (Atmospheric or Power) ..................................................................................................
Standing Pilot or Electric Ignition .....................................................................................................
Non-Condensing NOX Type and Separate Condensing ..................................................................
All Electric Types Separate ..............................................................................................................
Heat Pump Separate ........................................................................................................................
6.59
6.52
6.66
4.61
5.53
5.53
3.98
N/A
N/A
2. Conversion Factor Derivation
DOE used the methods described in
section III.C to derive the mathematical
conversion factor for the different types
of water heaters covered within the
scope of this rulemaking (as discussed
in section III.B). This section describes
the methodology that was applied to
develop a conversion factor for each
type of water heater.
a. Consumer Storage Water Heaters
i. Test Results
As stated in section III.D.1, DOE has
conducted testing of 43 consumer
Oil-fired
6.89 .............
5.79 .............
Not enough
units.
No short
units.
5.73 .............
5.82 .............
N/A ..............
N/A ..............
N/A ..............
N/A ..............
N/A ..............
N/A ..............
N/A ..............
Electric
4.47.
3.67.
3.88.
Not enough
short units.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
3.43.
3.59.
storage water heaters using both the
current and new test procedures. Table
III.13 below presents the test data used
to derive the consumer storage water
heater conversion factors. Table III.14
shows the water heater attributes by
unit described in section III.D.1.
TABLE III.13—CONSUMER STORAGE WATER HEATER TEST DATA
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Unit No.
Type
CS–1 ................................
CS–2 ................................
CS–3 ................................
CS–4 ................................
CS–5 ................................
CS–6 ................................
CS–7 ................................
CS–8 ................................
CS–9 ................................
CS–10 ..............................
CS–11 ..............................
Storage
volume
(gal)
Heat Pump
Heat Pump
Heat Pump
Heat Pump
Heat Pump
Electric .......
Electric .......
Electric .......
Electric .......
Electric ......
Electric ......
VerDate Sep<11>2014
19:01 Apr 13, 2015
Jkt 235001
Input
rate
(Btu/h)
45.2
45.5
58.9
77.6
80.8
36.2
44.9
46.1
27.4
34.1
35.9
PO 00000
Frm 00016
13,600
8,500
6,800
6,800
1,800
15,400
14,300
14,000
13,000
14,000
15,400
Fmt 4701
Current
FHR
(gal)
Updated
FHR
(gal)
59.1
57.3
71.5
90.5
57.0
54.0
64.1
64.8
38.7
50.7
52.4
Sfmt 4702
48.2
57.0
68.6
87.1
58.0
49.7
64.3
61.7
43.1
52.0
51.8
E:\FR\FM\14APP2.SGM
Current
recovery
efficiency
(%)
264.7
269.0
290.1
285.0
288.0
98.0
98.0
98.0
98.0
98.0
98.0
14APP2
EF
2.260
2.272
2.406
2.315
2.330
0.941
0.855
0.901
0.912
0.902
0.931
UEF
2.069
2.575
2.493
2.641
2.540
0.905
0.840
0.919
0.906
0.907
0.920
20131
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
TABLE III.13—CONSUMER STORAGE WATER HEATER TEST DATA—Continued
Unit No.
CS–12
CS–13
CS–14
CS–15
CS–16
CS–17
CS–18
CS–19
CS–20
CS–21
CS–22
CS–23
CS–24
CS–25
CS–26
CS–27
CS–28
CS–29
CS–30
CS–31
CS–32
CS–33
CS–34
CS–35
CS–36
CS–37
CS–38
CS–39
CS–40
CS–41
CS–42
CS–43
Type
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
..............................
Storage
volume
(gal)
Electric ......
Electric ......
Electric ......
Electric ......
Electric ......
Tabletop ....
Tabletop ....
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Oil ..............
Oil ..............
Input
rate
(Btu/h)
36.1
44.9
45.8
49.7
72.2
25.7
35.1
38.4
49.5
37.8
47.6
37.9
38.0
38.0
38.1
38.2
27.9
38.1
38.3
47.3
38.6
38.9
27.9
38.5
47.8
45.7
38.2
38.2
47.8
48.1
29.8
30.1
Current
FHR
(gal)
15,400
15,400
15,400
18,800
14,700
15,400
15,400
39,800
44,100
39,700
49,900
39,400
32,600
39,800
40,800
39,300
31,600
40,200
37,900
50,600
40,100
32,400
59,000
36,000
64,600
39,800
40,300
38,300
40,500
36,000
105,300
105,300
Updated
FHR
(gal)
53.2
64.9
62.7
68.5
88.7
37.5
52.9
67.0
97.4
70.1
90.2
74.4
66.9
80.2
73.5
71.9
58.8
74.7
71.9
95.1
70.2
68.6
96.9
66.0
107.9
91.0
68.2
71.3
94.2
92.4
104.8
112.5
Current
recovery
efficiency
(%)
54.8
59.4
64.2
73.2
80.9
45.3
47.8
81.1
86.6
86.9
81.0
81.6
58.5
63.8
75.2
77.6
64.4
70.6
64.6
87.0
67.2
65.2
94.5
68.0
108.8
84.8
64.8
64.6
83.8
88.2
111.7
127.4
EF
98.0
98.0
98.0
98.0
98.0
98.0
98.0
80.5
80.5
83.8
81.1
80.3
69.0
83.6
83.6
77.4
80.7
80.5
78.5
78.8
80.4
78.1
78.2
85.0
79.5
96.3
79.7
75.2
74.0
81.4
71.4
89.4
UEF
0.912
0.960
0.922
0.924
0.848
0.905
0.878
0.601
0.610
0.608
0.674
0.691
0.574
0.711
0.702
0.607
0.620
0.622
0.616
0.606
0.673
0.666
0.702
0.699
0.649
0.830
0.606
0.625
0.550
0.631
0.518
0.605
0.927
0.926
0.936
0.940
0.883
0.857
0.804
0.630
0.634
0.641
0.675
0.705
0.566
0.669
0.716
0.635
0.606
0.569
0.434
0.640
0.647
0.624
0.709
0.670
0.672
0.828
0.595
0.596
0.641
0.662
0.478
0.641
TABLE III.14—CONSUMER STORAGE WATER HEATER ATTRIBUTES
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Unit No.
NOX emission
level
Condensing
Vent type
Short or tall
CS–1 .....................................................................
CS–2 .....................................................................
CS–3 .....................................................................
CS–4 .....................................................................
CS–5 .....................................................................
CS–6 .....................................................................
CS–7 .....................................................................
CS–8 .....................................................................
CS–9 .....................................................................
CS–10 ...................................................................
CS–11 ...................................................................
CS–12 ...................................................................
CS–13 ...................................................................
CS–14 ...................................................................
CS–15 ...................................................................
CS–16 ...................................................................
CS–17 ...................................................................
CS–18 ...................................................................
CS–19 ...................................................................
CS–20 ...................................................................
CS–21 ...................................................................
CS–22 ...................................................................
CS–23 ...................................................................
CS–24 ...................................................................
CS–25 ...................................................................
CS–26 ...................................................................
CS–27 ...................................................................
CS–28 ...................................................................
CS–29 ...................................................................
CS–30 ...................................................................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
Standard ...........
Standard ...........
Standard ...........
Standard ...........
Low ...................
Low ...................
Low ...................
Low ...................
Low ...................
Low ...................
Low ...................
Low ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
Atmospheric ......
Atmospheric ......
Atmospheric ......
Power ...............
Atmospheric ......
Atmospheric ......
Atmospheric ......
Atmospheric ......
Atmospheric ......
Atmospheric ......
Atmospheric ......
Atmospheric ......
N/A ...................
N/A ...................
N/A ...................
N/A ...................
N/A ...................
Short .................
Short .................
Short .................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
N/A ...................
N/A ...................
Short .................
Short .................
Tall ....................
Tall ....................
Short .................
Short .................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
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19:01 Apr 13, 2015
Jkt 235001
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Fmt 4701
Sfmt 4702
E:\FR\FM\14APP2.SGM
14APP2
Standing pilot
or electric
ignition
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
Yes.
Yes.
Yes.
No.
No.
Yes.
No.
No.
No.
Yes.
Yes.
Yes.
20132
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
TABLE III.14—CONSUMER STORAGE WATER HEATER ATTRIBUTES—Continued
NOX emission
level
Unit No.
CS–31
CS–32
CS–33
CS–34
CS–35
CS–36
CS–37
CS–38
CS–39
CS–40
CS–41
CS–42
CS–43
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
...................................................................
Condensing
Vent type
Short or tall
Low ...................
Low ...................
Low ...................
Low ...................
Low ...................
Low ...................
Low ...................
Ultra-Low ..........
Ultra-Low ..........
Ultra-Low ..........
Ultra-Low ..........
N/A ...................
N/A ...................
No .....................
No .....................
No .....................
No .....................
No .....................
No .....................
Yes ...................
No .....................
No .....................
No .....................
No .....................
N/A ...................
N/A ...................
Atmospheric ......
Power ...............
Power ...............
Power ...............
Power ...............
Power ...............
Power ...............
Atmospheric ......
Atmospheric ......
Atmospheric ......
Atmospheric ......
N/A ...................
N/A ...................
Tall ....................
Short .................
Short .................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Short .................
Short .................
Tall ....................
Tall ....................
Tall ....................
Tall ....................
Standing pilot
or electric
ignition
Yes.
No.
No.
No.
No.
No.
No.
Yes.
Yes.
Yes.
Yes.
N/A.
N/A.
where FHRnew is the new first hour
rating, FHRex is the existing first hour
rating, and the slope and intercept are
constants obtained from a linear
regression. While most of the data
allowed for such a regression fit, in two
cases (oil, non-condensing gas with
standard level NOX burners) the
available data were too limited to
produce reliable regressions. In these
cases, the intercepts of the regressions
were assigned a value of zero, meaning
that a water heater with an FHRex of
zero would also have an FHRnew of zero.
The next step in the conversion is to
determine which draw pattern is to be
applied to convert from EF to UEF. After
the first-hour rating under the uniform
efficiency descriptor is determined
through the conversion factor above, the
value can be applied to determine the
appropriate draw pattern bin (i.e., very
small, low, medium, or high) using
Table III.3 of this NOPR or Table 1 of
the uniform efficiency descriptor test
procedure. 79 FR 40542, 40572 (July 11,
2014). With the draw bin known, the
UEF value based on the WHAM
analytical model can be calculated using
the process described in section
III.C.2.c.i for all types except for heat
pump water heaters. Alternatively, DOE
investigated the step regression
approach described in section III.C.3 to
convert EF to UEF. DOE found that a
third technique, a combination of these
approaches in which the results of the
WHAM analytical model are used as the
independent variable in a standard
linear regression analysis, produced the
best results. Separate conversion
equations were developed for the same
categories as used for first-hour rating.
The results of the first-hour regression,
the WHAM analytical model, the step
regression model, and the combined
WHAM-regression model are presented
below in Table III.16. The RMS errors
for the classes range from 0.0014 to
0.0495 when using a combined WHAMregression model. For heat pump water
heaters, a linear regression in which the
UEF is estimated solely from the
existing EF results in an RMS error of
0.187. Considering the larger magnitude
of UEFs for heat pump water heaters,
DOE has tentatively concluded that this
relatively high RMS error is acceptable
for heat pump water heaters. DOE has,
therefore, tentatively decided to use the
combined WHAM-regression approach
to calculate the consumer storage water
heater conversion factor for non-heat
pump water heaters and to apply a
regression that relates UEF to EF for
heat pump water heaters. The WHAMregression approach accounts for the
test procedure changes in terms of daily
volume delivered and storage tank
temperature, and it corrects for the
unaccounted changes using a regression
with actual test data. Because the data
are not believed to be publicly available
to compute the WHAM estimate for heat
pump water heaters, DOE proposes to
base this conversion on an empirical
regression. The resulting equations for
determining the UEF of consumer
storage water heaters are:
UEFGas,Non-Condensing,Standard NOx = 0.2726 *
UEFWHAM + 0.4736
UEFGas,Non-Condensing,Low NOx = 0.9966 *
UEFWHAM ¥ 0.0126
UEFGas,Non-Condensing,Ultra-Low NOx = 0.5811
*UEFWHAM + 0.2673
asabaliauskas on DSK5VPTVN1PROD with NOTICES
VerDate Sep<11>2014
19:01 Apr 13, 2015
Jkt 235001
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Fmt 4701
Sfmt 4702
E:\FR\FM\14APP2.SGM
14APP2
EP14AP15.015</GPH>
For consumer storage water heaters,
DOE proposes to use the regression
method described in section III.C.3 to
develop new first hour ratings. Of the
factors considered, DOE found that the
existing first hour rating was the best
overall predictor of the new first hour
rating. These findings were based on the
root mean squared errors between
predictions and measured values. In
some cases, addition of other factors in
the regressions (e.g., input rate, storage
volume) led to predictions with slightly
better RMS values, but DOE chose to be
consistent in its formulations by using
the same factor, existing first hour
ratings. In these cases, DOE found that
addition of extra terms improved the
RMS value by less than 1 gallon, so it
tentatively concluded that the added
potential for confusion is not warranted.
The resulting equations for determining
the FHRnew of consumer storage water
heaters are:
New FHRGas,Non-Condensing,Standard NOx =
1.0085 * FHREx
New FHRGas,Non-Condensing,Low NOx = 4.6894
+ 0.9112 * FHREx
New FHRGas,Non-Condensing,Ultra–Low NOx =
2.9267 + 0.8882 * FHREx
New FHRGas,Condensing = ¥0.7072 +
0.9724 * FHREx
New FHROil = 1.1018 * FHREx
New FHRElectric,Conventional&Tabletop =
11.9239 + 0.7879 * FHREx
New FHRElectric,Heat Pump = ¥2.3440 +
0.9856 * FHREx
ii. Conversion Factor Results
20133
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
UEFGas,Condensing = 0.9164 * UEFWHAM +
0.0409
UEFOil = 1.1185 * UEFWHAM ¥ 0.0945
UEFElectric,Conventional&Tabletop = 0.8673 *
UEFWHAM + 0.1227
UEFElectric,Heat Pump = 1.5485 * EF ¥
1.1235
where UEFWHAM is the conversion factor
calculated using the WHAM analytical
model and the coefficient values shown
in Table III.15, P is the nameplate input
rate in Btu/h, and hr is the recovery
efficiency expressed in decimal form
(e.g., 0.98 instead of 98 [%]).
TABLE III.15—COEFFICIENTS FOR WHAM-BASED UEF CONVERSION FACTOR
Draw bin
a
Very Small .......................................................................................................
Low ..................................................................................................................
Medium ............................................................................................................
High ..................................................................................................................
b
56095146
56095146
56095146
56095146
c
12884892499
48962591496
70866908744
108233096990
d
8930623
33936368
49118427
75017235
15125743368
57477824799
83191588525
127056244293
TABLE III.16—CONSUMER STORAGE WATER HEATER CONVERSION FACTOR RESULTS
asabaliauskas on DSK5VPTVN1PROD with NOTICES
CS–1 ....................................................................
CS–2 ....................................................................
CS–3 ....................................................................
CS–4 ....................................................................
CS–5 ....................................................................
CS–6 ....................................................................
CS–7 ....................................................................
CS–8 ....................................................................
CS–9 ....................................................................
CS–10 ..................................................................
CS–11 ..................................................................
CS–12 ..................................................................
CS–13 ..................................................................
CS–14 ..................................................................
CS–15 ..................................................................
CS–16 ..................................................................
CS–17 ..................................................................
CS–18 ..................................................................
CS–19 ..................................................................
CS–20 ..................................................................
CS–21 ..................................................................
CS–22 ..................................................................
CS–23 ..................................................................
CS–24 ..................................................................
CS–25 ..................................................................
CS–26 ..................................................................
CS–27 ..................................................................
CS–28 ..................................................................
CS–29 ..................................................................
CS–30 ..................................................................
CS–31 ..................................................................
CS–32 ..................................................................
CS–33 ..................................................................
CS–34 ..................................................................
CS–35 ..................................................................
CS–36 ..................................................................
CS–37 ..................................................................
CS–38 ..................................................................
CS–39 ..................................................................
CS–40 ..................................................................
CS–41 ..................................................................
CS–42 ..................................................................
CS–43 ..................................................................
b. Consumer Instantaneous
i. Test Results
As stated in section III.D.1, DOE has
tested 22 consumer instantaneous water
heaters to both the current and new test
procedures. Table III.17 presents the test
VerDate Sep<11>2014
19:01 Apr 13, 2015
Regression
FHR
(gal)
Tested FHR
(gal)
Unit No.
Jkt 235001
48.2
57.0
68.6
87.1
58.0
49.7
64.3
61.7
43.1
52.0
51.8
54.8
59.4
64.2
73.2
80.9
45.3
47.8
81.1
86.6
86.9
81.0
81.6
58.5
63.8
75.2
77.6
64.4
70.6
64.6
87.0
67.2
65.2
94.5
68.0
108.8
84.8
64.8
64.6
83.8
88.2
111.7
127.4
55.9
54.1
68.1
86.9
53.8
54.4
62.4
62.9
42.4
51.8
53.2
53.9
63.0
61.4
65.9
81.8
41.5
53.6
67.5
98.3
70.7
91.0
72.5
65.6
77.8
71.6
70.2
58.3
72.8
70.2
91.4
68.6
67.2
93.0
64.8
103.0
87.8
63.5
66.3
86.6
85.0
115.5
123.9
Tested
UEF
2.069
2.575
2.493
2.641
2.540
0.905
0.840
0.919
0.906
0.907
0.920
0.927
0.926
0.936
0.940
0.883
0.857
0.804
0.630
0.634
0.641
0.675
0.705
0.566
0.669
0.716
0.635
0.606
0.569
0.434
0.640
0.647
0.624
0.709
0.670
0.672
0.828
0.595
0.596
0.641
0.662
0.478
0.641
data used to derive the consumer
instantaneous water heater conversion
factors. It is noted that test results show
measured recovery efficiencies above
100 percent and EFs and UEFs above 1
for electric instantaneous units; DOE
PO 00000
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Fmt 4701
Sfmt 4702
WHAM
UEF
2.209
2.215
2.339
2.435
2.213
0.935
0.836
0.888
0.866
0.888
0.923
0.901
0.956
0.912
0.915
0.880
0.855
0.862
0.578
0.651
0.583
0.705
0.676
0.558
0.739
0.685
0.587
0.598
0.600
0.595
0.645
0.656
0.651
0.721
0.679
0.681
0.861
0.583
0.609
0.589
0.670
0.557
0.659
Regression
UEF
2.375
2.395
2.603
2.461
2.484
0.930
0.875
0.904
0.911
0.905
0.923
0.911
0.941
0.917
0.919
0.871
0.896
0.873
0.632
0.637
0.636
0.675
0.683
0.571
0.702
0.694
0.603
0.616
0.617
0.611
0.602
0.666
0.660
0.694
0.690
0.643
0.824
0.592
0.599
0.653
0.649
0.537
0.613
WHAMRegression
UEF
2.384
2.391
2.525
2.630
2.388
0.933
0.847
0.893
0.874
0.893
0.923
0.904
0.952
0.914
0.916
0.885
0.864
0.870
0.631
0.651
0.632
0.666
0.661
0.544
0.724
0.670
0.572
0.583
0.585
0.580
0.630
0.641
0.636
0.706
0.664
0.666
0.830
0.606
0.621
0.610
0.656
0.529
0.643
acknowledges that these results appear
to violate theoretical limits and believes
that these results are an artifact of
measurement uncertainty. Table III.18
shows the water heater attributes by
unit described in section III.D.1.
E:\FR\FM\14APP2.SGM
14APP2
20134
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
TABLE III.17—CONSUMER INSTANTANEOUS WATER HEATER TEST DATA
Unit No.
CI–1 ..................................
CI–2 ..................................
CI–3 ..................................
CI–4 ..................................
CI–5 ..................................
CI–6 ..................................
CI–7 ..................................
CI–8 ..................................
CI–9 ..................................
CI–10 ................................
CI–11 ................................
CI–12 ................................
CI–13 ................................
CI–14 ................................
CI–15 ................................
CI–16 ................................
CI–17 ................................
CI–18 ................................
CI–19 ................................
CI–20 ................................
CI–21 ................................
CI–22 ................................
Input rate
(Btu/h)
Type
Electric ......
Electric ......
Electric ......
Electric ......
Electric ......
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
Gas ............
8,200
32,400
34,100
27,300
20,500
179,900
178,500
120,900
199,000
151,900
141,100
190,400
142,500
197,200
199,800
151,500
180,400
175,800
199,200
154,100
201,300
199,900
Current
max GPM
Updated
max GPM
0.20
0.82
0.87
0.68
0.52
4.01
4.08
2.69
4.61
3.47
3.11
4.23
2.96
5.19
4.80
3.24
3.92
3.67
4.30
3.98
4.90
5.12
Current
recovery
efficiency
(%)
0.23
0.93
0.99
0.80
0.59
4.58
4.71
3.07
4.86
3.96
3.61
4.81
3.43
5.80
4.10
3.88
4.60
4.30
5.07
4.47
5.70
4.91
101.2
101.5
101.8
102.0
102.3
82.4
83.8
84.1
87.0
88.3
81.4
83.4
80.9
96.7
93.8
84.3
85.0
84.5
75.0
91.6
88.0
89.9
EF
UEF
1.012
1.017
1.018
1.019
1.021
0.821
0.837
0.839
0.876
0.891
0.810
0.829
0.801
0.966
0.932
0.837
0.853
0.838
0.743
0.913
0.851
0.888
0.982
0.981
1.001
1.004
1.005
0.832
0.828
0.814
0.841
0.815
0.824
0.818
0.795
0.958
0.931
0.805
0.827
0.830
0.799
0.922
0.884
0.943
TABLE III.18—CONSUMER INSTANTANEOUS WATER HEATER ATTRIBUTES
Unit No.
NOX emission level
Condensing
CI–1 .........................................................
CI–2 .........................................................
CI–3 .........................................................
CI–4 .........................................................
CI–5 .........................................................
CI–6 .........................................................
CI–7 .........................................................
CI–8 .........................................................
CI–9 .........................................................
CI–10 .......................................................
CI–11 .......................................................
CI–12 .......................................................
CI–13 .......................................................
CI–14 .......................................................
CI–15 .......................................................
CI–16 .......................................................
CI–17 .......................................................
CI–18 .......................................................
CI–19 .......................................................
CI–20 .......................................................
CI–21 .......................................................
CI–22 .......................................................
N/A .........................................................
N/A .........................................................
N/A .........................................................
N/A .........................................................
N/A .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Low .........................................................
Ultra-Low ................................................
Ultra-Low ................................................
Ultra-Low ................................................
Ultra-Low ................................................
Ultra-Low ................................................
Ultra-Low ................................................
Ultra-Low ................................................
N/A .........................................................
N/A .........................................................
N/A .........................................................
N/A .........................................................
N/A .........................................................
No ...........................................................
No ...........................................................
No ...........................................................
No ...........................................................
No ...........................................................
No ...........................................................
No ...........................................................
No ...........................................................
Yes .........................................................
Yes .........................................................
No ...........................................................
No ...........................................................
No ...........................................................
No ...........................................................
Yes .........................................................
Yes .........................................................
Yes .........................................................
asabaliauskas on DSK5VPTVN1PROD with NOTICES
ii. Conversion Factor Results
As stated in section III.C.2, DOE
developed an analytical model to
convert the existing maximum GPM
rating for consumer instantaneous water
heaters to ratings under the uniform
efficiency descriptor test procedure.
DOE also attempted to develop an
analytical method based on the WHAM
equation to estimate the change in
existing energy factor ratings under the
existing consumer water heater test
procedure to values under the uniform
efficiency descriptor test procedure.
VerDate Sep<11>2014
19:01 Apr 13, 2015
Jkt 235001
Along with this analytical model, step
regression and combined analytical
model-regression approaches were
conducted. The results of the analytical
model, step regression, and combined
analytical model-regression approaches
for the maximum GPM and UEF
conversions are presented in Table
III.20. For the maximum GPM
conversions, the RMS errors for the
three approaches are 0.38, 0.35, and
0.38, respectively. For the UEF
conversions, the three approaches have
RMS errors of 0.024, 0.028, and 0.023,
PO 00000
Frm 00020
Fmt 4701
Sfmt 4702
Vent type
N/A.
N/A.
N/A.
N/A.
N/A.
Atmospheric.
Atmospheric.
Atmospheric.
Atmospheric.
Atmospheric.
Power.
Power.
Power.
Atmospheric.
Atmospheric.
Atmospheric.
Atmospheric.
Atmospheric.
Atmospheric.
Atmospheric.
Atmospheric.
Power.
respectively. DOE has tentatively
decided to use the analytical model
approach to calculate the consumer
instantaneous maximum GPM
conversion factor owing to the fact that
the model predicts the resultant data
very closely and that it will broadly
apply to those units not tested. DOE has
also tentatively decided to use the
combined analytical model-regression
approach to convert from EF to UEF
since the RMS errors are low, and it has
tentatively concluded that the use of the
model and regression will capture key
E:\FR\FM\14APP2.SGM
14APP2
20135
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
applied during the simulated-use test
and are provided in Table III.19.
UEFgas = 0.9059 * UEFmodel + 0.0783
effects that may not be captured with
either approach by itself. For the electric
instantaneous water heaters, DOE
imposed a zero intercept on the
regression since the regression with an
intercept resulted in UEFs above the
theoretical limit of 1. DOE has
tentatively concluded that this step is
technically acceptable, as it effectively
states that a water heater with an EF of
zero should also have a UEF of zero.
The resulting conversion factors for both
first hour rating and UEF are:
MaxGPMnew = 1.147 * MaxGPMEx
UEFelectric = 1.0079 * UEFmodel
where MaxGPMEx is the maximum GPM
rating based on the current DOE test
procedure and UEFmodel is the predicted
UEF determined using the following
analytical model:
TABLE III.19—COEFFICIENTS TO DETERMINE UEFmodel FOR CONSUMER
INSTANTANEOUS WATER HEATERS
Draw bin
A
Very Small ................
Low ...........................
Medium .....................
High ..........................
Values for the coefficients A and B are
dependent upon the draw pattern
5514.2
20954
30328
46319
B
170.2
262.4
290.9
294.0
TABLE III.20—CONSUMER INSTANTANEOUS WATER HEATER CONVERSION FACTOR RESULTS
Analytical
max
GPM
Tested max
GPM
Unit No.
CI–1 ..................
CI–2 ..................
CI–3 ..................
CI–4 ..................
CI–5 ..................
CI–6 ..................
CI–7 ..................
CI–8 ..................
CI–9 ..................
CI–10 ................
CI–11 ................
CI–12 ................
CI–13 ................
CI–14 ................
CI–15 ................
CI–16 ................
CI–17 ................
CI–18 ................
CI–19 ................
CI–20 ................
CI–21 ................
CI–22 ................
0.23
0.93
0.99
0.80
0.59
4.58
4.71
3.07
4.86
3.96
3.61
4.81
3.43
5.80
4.10
3.88
4.60
4.30
5.07
4.47
5.70
4.91
0.23
0.94
1.00
0.78
0.59
4.60
4.68
3.08
5.28
3.98
3.56
4.85
3.39
5.95
5.50
3.71
4.49
4.21
4.93
4.56
5.62
5.87
c. Residential-Duty Commercial Storage
Testing
i. Test Data
As stated in section III.D.2, DOE has
tested 7 residential-duty commercial
Combined
analyticalregression
max GPM
Regression
max GPM
0.24
0.94
1.00
0.78
0.60
4.58
4.66
3.17
5.22
4.01
3.62
4.82
3.46
5.84
5.43
3.76
4.49
4.22
4.90
4.55
5.54
5.77
0.23
0.94
1.00
0.78
0.59
4.60
4.68
3.08
5.28
3.98
3.56
4.85
3.39
5.95
5.50
3.71
4.49
4.21
4.93
4.56
5.62
5.87
Tested
UEF
Analytical
UEF
0.982
0.981
1.001
1.004
1.005
0.832
0.828
0.814
0.841
0.815
0.824
0.818
0.795
0.958
0.931
0.805
0.827
0.830
0.799
0.922
0.884
0.943
storage water heaters to both the current
and new test procedures. Table III.21
below presents the test data used to
derive the residential-duty commercial
storage water heater conversion factors.
0.982
0.984
0.987
0.989
0.991
0.820
0.834
0.834
0.865
0.878
0.808
0.829
0.803
0.961
0.933
0.836
0.845
0.840
0.746
0.911
0.875
0.894
Regression
UEF
0.980
0.987
0.995
1.001
1.008
0.816
0.829
0.830
0.859
0.871
0.807
0.822
0.800
0.931
0.904
0.829
0.841
0.829
0.754
0.889
0.840
0.869
Analyticalregression
UEF
0.989
0.992
0.995
0.997
0.999
0.820
0.833
0.834
0.861
0.873
0.810
0.829
0.805
0.948
0.923
0.835
0.844
0.839
0.754
0.903
0.870
0.887
Table III.22 shows the water heater
attributes by unit described in section
III.D.2.
TABLE III.21—RESIDENTIAL-DUTY COMMERCIAL STORAGE WATER HEATER TEST DATA
RD–1
RD–2
RD–3
RD–4
RD–5
RD–6
RD–7
..............................
..............................
..............................
..............................
..............................
..............................
..............................
VerDate Sep<11>2014
Type
Gas
Gas
Gas
Gas
Gas
Gas
Gas
19:01 Apr 13, 2015
Storage
volume
(gal)
.............
.............
.............
.............
.............
.............
.............
Jkt 235001
95.4
72.7
71.3
48.3
48.4
47.8
71.0
PO 00000
Frm 00021
Tested thermal
efficiency
(%)
Input rate
(Btu/h)
79,100
67,400
69,700
76,500
75,300
75,700
63,800
Fmt 4701
Sfmt 4702
80.4
67.9
75.5
93.6
88.9
90.0
67.1
Tested
standby loss
(Btu/h)
1,178.2
721.0
839.4
328.0
338.1
358.4
1,546.8
E:\FR\FM\14APP2.SGM
14APP2
Updated FHR
(gal)
109.8
90.3
119.3
137.0
126.5
103.3
111.5
UEF
0.514
0.585
0.619
0.816
0.725
0.621
0.470
EP14AP15.016</GPH>
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Unit No.
20136
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
TABLE III.22—RESIDENTIAL-DUTY COMMERCIAL STORAGE WATER HEATER ATTRIBUTES
NOX
emission level
Condensing
Vent type
Short or tall
Standard ...........
Standard ...........
Standard ...........
Low ...................
Low ...................
Low ...................
Ultra-Low ..........
No .....................
No .....................
No .....................
Yes ...................
Yes ...................
Yes ...................
No .....................
Atmospheric ......
Power ...............
Power ...............
Atmospheric ......
Power ...............
Power ...............
Atmospheric ......
Tall ....................
Tall ....................
Tall ....................
Short .................
Tall ....................
Tall ....................
Tall ....................
Unit No.
RD–1
RD–2
RD–3
RD–4
RD–5
RD–6
RD–7
.....................................................................
.....................................................................
.....................................................................
.....................................................................
.....................................................................
.....................................................................
.....................................................................
ii. Conversion Factor Results
As stated in section III.C.2.b, DOE is
not aware of an analytical model to
convert the thermal efficiency and
standby loss ratings under the current
test procedure to first-hour rating values
under the new test procedure.
Therefore, the step regression method
described in section III.C.3 along with
the best combination of water heater
attributes were used to determine the
following first-hour rating conversion
factors:
New FHRFossil Fuel = 1.0226 * Q + 39.81
Where Q is the input rate of the burner
in kBtu/h. For this regression, DOE
decided to group both oil and gas water
heaters because of the lack of oil water
heaters identified. DOE has tentatively
concluded that this grouping is the best
approach to convert ratings for any
residential-duty oil water heater on the
market.
The next step in the conversion is to
determine which draw pattern is to be
applied to convert to UEF. After the
first-hour rating under the uniform
efficiency descriptor is determined
through the conversion factor above, the
value can be applied to determine the
appropriate draw pattern bin (i.e., very
small, low, medium, or high) using
Table III.3 of this NOPR or Table 1 of
the uniform efficiency descriptor test
procedure. 79 FR 40542, 40572 (July 11,
2014). With the draw bin known, the
UEF value based on the analytical
model can be calculated using the
process described in section III.C.2.c.iii.
The analytical results, along with the
results of the step regression and
analytical-regression are shown in Table
III.23 and have RMS values of 0.074,
0.055, and 0.053, respectively. Based on
these results, DOE has tentatively
decided to use the combined analyticalregression approach to calculate the
residential-duty commercial storage
water heater conversion factor. While
the regression approach yields a slightly
better RMS error, DOE has tentatively
concluded that the use of the analytical
model will make the conversion more
Standing pilot
or electric
ignition
Yes.
No.
No.
No.
No.
No.
Yes.
robust over the entire family of
residential-duty commercial storage
water heaters since it captures the
effects of water temperature, draw
volume per day, thermal efficiency, and
standby loss that are expected to be
valid for any water heater. Thus, the use
of an analytical model is expected to be
less prone to error should a model have
some unexpected characteristic that was
not captured in the water heaters tested
as part of this NOPR. The resulting
equations for determining the UEF of
consumer storage water heaters are:
UEFfossil fuel = 0.7300 * UEFrd + 0.1413
Where UEFrd is the estimate of the UEF
for residential-duty water heaters
computed with the following equation:
where C1 is a constant dependent upon
the draw pattern given in Table III.6, Et
is the thermal efficiency in fractional
form (i.e., 0.85 instead of 85 (%)), and
SL is the standby loss in BTU/h.
TABLE III.23—RESIDENTIAL-DUTY COMMERCIAL CONVERSION FACTOR RESULTS
RD–1
RD–2
RD–3
RD–4
RD–5
RD–6
RD–7
............................................
............................................
............................................
............................................
............................................
............................................
............................................
109.8
90.3
119.3
137.0
126.5
103.3
111.5
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d. Residential-Duty Instantaneous
Testing
As discussed in section III.B.2, no
instantaneous residential-duty
commercial water heaters exist on the
market. Therefore, a conversion factor is
not needed.
3. Energy Conservation Standard
Derivation
After developing the mathematical
conversion factors to convert from the
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Regression
FHR
(gal)
Tested UEF
120.7
108.8
111.1
118.0
116.9
117.3
105.0
Analytical UEF
0.514
0.585
0.619
0.816
0.725
0.621
0.470
existing efficiency ratings to the
efficiency ratings under the UEF metric,
DOE sought to update its energy
conservation standards for covered
water heater products so as to be in
terms of UEF. DOE investigated several
possible methods to determine the
appropriate energy conservation
standards in terms of UEF.
First, DOE considered the ‘‘percent
difference’’ method, which is the
method DOE ultimately has proposed
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0.573
0.562
0.595
0.828
0.788
0.791
0.466
Regression
UEF
0.530
0.629
0.604
0.715
0.713
0.709
0.449
Analyticalregression
UEF
0.560
0.551
0.575
0.746
0.717
0.719
0.481
for updating the energy conservation
standards so as to be based on the UEF
metric. The percent difference method
was conducted as follows:
1. Apply conversion factor to convert
the current efficiency metrics provided
in the relevant consumer or commercial
database to the calculated UEF value for
each water heater on the market.
2. Calculate the current efficiency
standard for each water heater in the
database, as follows:
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Tested FHR
(gal)
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a. For consumer water heaters, find
the minimum EF.
b. For residential-duty commercial
water heaters, find the minimum
thermal efficiency.
3. Find the percent difference
between the rated efficiency value and
the standard for each water heater in the
database, as follows:
4. Find the new energy conservation
standard for each water heater in the
database, as follows:
a. UEFmin = UEF (1 ¥ PD)
5. Find a line through their minimum
UEF values.
The advantage of using a ‘‘percent
difference’’ is that the updated energy
conservation standard is a function of
the UEF conversion for all water heaters
rather than a subset. It also allows for
conversions of standards for classes or
groupings of water heaters where no
minimally compliant models are
currently available on the market. The
proposed standards in terms of uniform
energy factor are shown below by
product class and draw pattern.
TABLE III.24—UPDATED CONSUMER WATER HEATER ENERGY CONSERVATION STANDARDS
Product class
Rated storage volume
Draw pattern
Gas-fired Storage ............................................
≥20 gal and ≤55 gal ........................................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
All ..........................
All ..........................
>55 gal and ≤100 gal ......................................
Oil-fired Storage ..............................................
≤50 gal ............................................................
Electric Storage ...............................................
≥20 gal and ≤55 gal ........................................
>55 gal and ≤120 gal ......................................
Tabletop Storage .............................................
≥20 gal and ≤100 gal ......................................
Gas-fired Instantaneous ..................................
Electric Instantaneous .....................................
<2 gal ..............................................................
<2 gal ..............................................................
Uniform energy factor
0.3263
0.5891
0.6326
0.7128
0.5352
0.7375
0.7704
0.7980
0.2267
0.4867
0.6016
0.6529
0.8268
0.9393
0.9683
0.9656
1.2701
1.9137
2.0326
2.1858
0.6808
0.8770
0.9063
0.9302
0.8036
0.9192
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
(0.0019
(0.0019
(0.0013
(0.0025
(0.0007
(0.0009
(0.0010
(0.0010
(0.0014
(0.0006
(0.0012
(0.0005
(0.0002
(0.0004
(0.0007
(0.0004
(0.0011
(0.0011
(0.0011
(0.0011
(0.0022
(0.0012
(0.0009
(0.0006
(0.0019
(0.0013
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as specified by the manufacturer.
TABLE III.25—UPDATED RESIDENTIAL-DUTY COMMERCIAL WATER HEATER ENERGY CONSERVATION STANDARDS
Product class
Draw pattern
Gas-fired Storage ..........................................................................................................................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
0.3261
0.5219
0.5585
0.6044
0.3206
0.5577
0.6027
0.6446
¥
¥
¥
¥
¥
¥
¥
¥
(0.0006
(0.0008
(0.0006
(0.0005
(0.0006
(0.0019
(0.0019
(0.0018
×
×
×
×
×
×
×
×
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as specified by the manufacturer.
As stated in section III.A, EEI
commented in response to the
November 2013 NOPR, that the updated
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energy conservation standards should
be not more stringent than they are
currently. The percent difference from
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the current rated energy factors and
energy conservation standards are used
to derive the new energy conservation
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Oil-fired Storage ............................................................................................................................
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standards; therefore, the updated
standards are no more stringent than
those currently in existence. A.O. Smith
and AHRI suggested that the average
difference between the current and new
ratings should not be used to convert
the energy conservation standards. At
no point in the conversion factor
derivation or energy conservation
standard analysis is a simple average
taken, but rather, the trends of all the
traditional factors affecting water
heaters are considered.
DOE also investigated a second
method of determining the energy
conservation standards where only test
data from minimally-compliant water
heaters would be used to develop a
conversion factor using the analytical
and regression methods described in
section III.C. Then, this set of
conversion factors could be applied to
the minimum energy conservation
standards to determine the appropriate
energy conservation standards in terms
of the UEF metric. This method would
remove from consideration any factors
that are present in more-efficient water
heaters, so the resulting change in the
standard would not be skewed at all by
the inclusion of higher-efficiency
products in the mathematical
conversion. However, the conversion
factors developed through such a
methodology would potentially not be
applicable for converting the efficiency
ratings of products above the baseline.
Therefore, DOE chose to pursue a
methodology that was applicable to all
water heaters and perform the
conversion of standards based on the
‘‘percent difference’’ method described
above.
DOE seeks comment on the most
appropriate method for determining the
energy conservation standards based on
the updated test procedure. This is
identified as issue 5 in section V.E,
‘‘Issues on Which DOE Seeks
Comment.’’
F. Certification and Labeling Issues
Consumer water heaters and
residential-duty commercial water
heaters manufactured prior to the
effective date of the uniform energy
factor test procedure final rule (i.e., July
13, 2015) that comply with the
efficiency standards and labeling
requirements in effect prior to that final
rule will be considered to comply with
the converted UEF standards and with
any revised labeling requirements
established by the Federal Trade
Commission (FTC) to carry out the final
rule. (42 U.S.C. 6295(e)(5)(K)) The
statute requires that the standard be in
terms of UEF as of July 13, 2015.
Accordingly, DOE proposes to require
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manufacturers to provide EF and UEF
for consumer water heaters (or thermal
efficiency and standby loss and UEF for
commercial residential-duty water
heaters) in certification reports filed
between July 13, 2015, and the
compliance date determined by the final
rule in this rulemaking. Manufacturers
would not be required to submit revised
certification reports for previously
certified basic models until the next
annual certification date (May 1).
Allowing manufacturers to submit
both EF and UEF data would allow
manufacturers to fulfill the statutory
requirement to begin using UEF for
purposes of compliance with standards
but would also allow manufacturers to
provide the necessary information to
determine costs under the current FTC
labeling requirements. This would also
allow a transition period for FTC to
pursue a rulemaking to determine
whether changes are needed to the
water heater EnergyGuide label due to
changes in the water heater test
procedure. DOE expects that the
conversion factors proposed in this
notice could be used to convert EF to
UEF for previously certified basic
models or to convert UEF values
‘‘backwards’’ to EF to determine the
appropriate costs for labeling of new
basic models until FTC has determined
whether to make changes to the label.
DOE has proposed a methodology for
calculating costs based on UEF testing
that could be used in future FTC
labeling requirements. DOE requests
comment on whether DOE should adopt
such a provision in the final rule in this
rulemaking or postpone adoption until
FTC has had an opportunity to evaluate
the ENERGY GUIDE label.
IV. Procedural Issues and Regulatory
Review
A. Review Under Executive Order 12866
The Office of Management and Budget
(OMB) has determined that test
procedure rulemakings do not constitute
‘‘significant regulatory actions’’ under
section 3(f) of Executive Order 12866,
Regulatory Planning and Review, 58 FR
51735 (Oct. 4, 1993). Accordingly, this
action was not subject to review under
the Executive Order by the Office of
Information and Regulatory Affairs
(OIRA) in the Office of Management and
Budget.
B. Review Under the Regulatory
Flexibility Act
The Regulatory Flexibility Act (5
U.S.C. 601 et seq.) requires preparation
of an initial regulatory flexibility
analysis (IFRA) for any rule that by law
must be proposed for public comment,
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unless the agency certifies that the rule,
if promulgated, will not have a
significant economic impact on a
substantial number of small entities. As
required by Executive Order 13272,
‘‘Proper Consideration of Small Entities
in Agency Rulemaking,’’ 67 FR 53461
(August 16, 2002), DOE published
procedures and policies on February 19,
2003, to ensure that the potential
impacts of its rules on small entities are
properly considered during the DOE
rulemaking process. 68 FR 7990. DOE
has made its procedures and policies
available on the Office of the General
Counsel’s Web site: https://energy.gov/
gc/office-general-counsel.
This proposed rule would prescribe a
mathematical conversion that would be
used to determine compliance with
energy conservation standards for
consumer water heaters and certain
commercial water heaters. For consumer
water heaters and certain commercial
water heaters, the mathematical
conversion would establish a bridge
between the rated values based on the
results under the current test procedures
and the uniform efficiency descriptor of
the new test procedure. Furthermore,
the conversion factor will ensure that no
products which currently pass energy
conservation standards fail to meet the
energy conservation standards after the
conversion factor has been applied. DOE
reviewed this proposed rule under the
provisions of the Regulatory Flexibility
Act and the policies and procedures
published on February 19, 2003. 68 FR
7990.
For the manufacturers of the covered
water heater products, the Small
Business Administration (SBA) has set a
size threshold, which defines those
entities classified as ‘‘small businesses’’
for the purposes of the statute. DOE
used the SBA’s small business size
standards to determine whether any
small entities would be subject to the
requirements of the rule. 65 FR 30836,
30849 (May 15, 2000), as amended at 65
FR 53533, 53545 (Sept. 5, 2000) and at
77 FR 49991, 50008–11 (August 20,
2012) and codified at 13 CFR part 121.
The size standards are listed by North
American Industry Classification
System (NAICS) code and industry
description and are available at https://
www.sba.gov/content/table-smallbusiness-size-standards. Consumer
water heater manufacturing is classified
under NAICS code 335228—‘‘Other
Major Household Appliance
Manufacturing.’’ The SBA sets a
threshold of 500 employees or less for
an entity to be considered as a small
business. Commercial water heater
manufacturing is classified under
NAICS code 333318—‘‘Other
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Commercial and Service Industry
Machinery Manufacturing,’’ for which
SBA sets a size threshold of 1,000
employees or fewer as being considered
a small business.
DOE has identified 19 manufacturers
of consumer water heaters (including
manufacturers of products that fall
under the expanded scope) that can be
considered small businesses. DOE
identified seven manufacturers of
‘‘residential-duty’’ commercial water
heaters that can be considered small
businesses. Six of the ‘‘residential-duty’’
commercial water heater manufacturers
also manufacture consumer water
heaters, so the total number of water
heater manufacturers impacted by this
rule would be 20. DOE’s research
involved reviewing several industry
trade association membership
directories (e.g., AHRI), product
databases (e.g., AHRI, CEC, and
ENERGY STAR databases), individual
company Web sites, and marketing
research tools (e.g., Hoovers reports) to
create a list of all domestic small
business manufacturers of products
covered by this rulemaking.
For the reasons explained below, DOE
has concluded that the test procedure
amendments contained in this proposed
rule would not have a significant
economic impact on any manufacturer,
including small manufacturers.
For consumer water heaters that were
covered under the old test procedure
and energy conservation standards, the
conversion factor in this proposed rule
would convert the rated values based on
the current test procedure to equivalent
values based on the new uniform
descriptor test procedure. Although the
energy conservation standards for
consumer water heaters will be
denominated using the uniform
descriptor, the statute provides that all
units that are on the market as of July
13, 2015, that meet the April 16, 2015
energy factor standard will be deemed
to meet the converted standards.
For certain commercial water heaters,
defined under the term ‘‘residentialduty commercial water heater,’’ the
conversion factor in this proposed rule
would convert the rated values based on
the current test procedure to the
uniform descriptor which is based on
the new test procedure. The energy
conservation standards for commercial
water heating equipment will be
denominated using the uniform
descriptor. The statute provides that all
units that are on the market as of July
13, 2015, that meet the thermal
efficiency and standby losses standards
will be deemed to meet the converted
standards.
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At the date that compliance is
required with the new test procedure,
all water heating units with residential
applications (i.e., consumer units and
residential-duty commercial units) must
meet the applicable energy conservation
standards. These units will be re-rated
to the uniform descriptor based on the
new test procedure. This conversion
will not result in any increase in
stringency of the energy conservation
standards. Therefore, no units that are
on the market at the time of this
rulemaking will be made illegal
(noncompliant) by this action.
Accordingly, DOE concludes and
certifies that this final rule would not
have a significant economic impact on
a substantial number of small entities,
so DOE has not prepared a regulatory
flexibility analysis for this rulemaking.
DOE will provide its certification and
supporting statement of factual basis to
the Chief Counsel for Advocacy of the
SBA for review under 5 U.S.C. 605(b).
C. Review Under the Paperwork
Reduction Act of 1995
Manufacturers of water heaters must
certify to DOE that their products
comply with any applicable energy
conservation standards. In certifying
compliance, manufacturers must test
their products according to the DOE test
procedures for water heaters, including
any amendments adopted for those test
procedures. DOE has established
regulations for the certification and
recordkeeping requirements for all
covered consumer products and
commercial equipment, including
consumer and commercial water
heaters. 76 FR 12422 (March 7, 2011);
79 FR 25486 (May 5, 2014). The
collection-of-information requirement
for the certification and recordkeeping
is subject to review and approval by
OMB under the Paperwork Reduction
Act (PRA). This requirement has been
approved by OMB under OMB control
number 1910–1400. Public reporting
burden for the certification is estimated
to average 30 hours per response,
including the time for reviewing
instructions, searching existing data
sources, gathering and maintaining the
data needed, and completing and
reviewing the collection of information.
Notwithstanding any other provision
of the law, no person is required to
respond to, nor shall any person be
subject to a penalty for failure to comply
with, a collection of information subject
to the requirements of the PRA, unless
that collection of information displays a
currently valid OMB Control Number.
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D. Review Under the National
Environmental Policy Act of 1969
In this proposed rule, DOE proposes
conversion factors to convert results
from existing efficiency and delivery
capacity metrics (and related energy
conservation standard requirements) for
consumer and certain commercial water
heaters to the uniform energy
descriptor. DOE has determined that
this rule falls into a class of actions that
are categorically excluded from review
under the National Environmental
Policy Act of 1969 (42 U.S.C. 4321 et
seq.) and DOE’s implementing
regulations at 10 CFR part 1021.
Specifically, this proposed rule would
amend the existing rule without
affecting the amount, quality or
distribution of energy usage, and,
therefore, would not result in any
environmental impacts. Thus, this
rulemaking is covered by Categorical
Exclusion A5 under 10 CFR part 1021,
subpart D, which applies to any
rulemaking that interprets or amends an
existing rule without changing the
environmental effect of that rule.
Accordingly, neither an environmental
assessment nor an environmental
impact statement is required.
E. Review Under Executive Order 13132
Executive Order 13132, ‘‘Federalism,’’
64 FR 43255 (August 10, 1999) imposes
certain requirements on agencies
formulating and implementing policies
or regulations that preempt State law or
that have Federalism implications. The
Executive Order requires agencies to
examine the constitutional and statutory
authority supporting any action that
would limit the policymaking discretion
of the States and to carefully assess the
necessity for such actions. The
Executive Order also requires agencies
to have an accountable process to
ensure meaningful and timely input by
State and local officials in the
development of regulatory policies that
have Federalism implications. On
March 14, 2000, DOE published a
statement of policy describing the
intergovernmental consultation process
it will follow in the development of
such regulations. 65 FR 13735. DOE has
examined this proposed rule and has
determined that it would not have a
substantial direct effect on the States, on
the relationship between the national
government and the States, or on the
distribution of power and
responsibilities among the various
levels of government. EPCA governs and
prescribes Federal preemption of State
regulations as to energy conservation for
the products that are the subject of this
proposed rule. States can petition DOE
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for exemption from such preemption to
the extent, and based on criteria, set
forth in EPCA. (42 U.S.C. 6297(d)) No
further action is required by Executive
Order 13132.
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F. Review Under Executive Order 12988
Regarding the review of existing
regulations and the promulgation of
new regulations, section 3(a) of
Executive Order 12988, ‘‘Civil Justice
Reform,’’ 61 FR 4729 (Feb. 7, 1996),
imposes on Federal agencies the general
duty to adhere to the following
requirements: (1) Eliminate drafting
errors and ambiguity; (2) write
regulations to minimize litigation; (3)
provide a clear legal standard for
affected conduct rather than a general
standard; and (4) promote simplification
and burden reduction. Regarding the
review required by section 3(a), section
3(b) of Executive Order 12988
specifically requires that Executive
agencies make every reasonable effort to
ensure that the regulation: (1) Clearly
specifies the preemptive effect, if any;
(2) clearly specifies any effect on
existing Federal law or regulation; (3)
provides a clear legal standard for
affected conduct while promoting
simplification and burden reduction; (4)
specifies the retroactive effect, if any; (5)
adequately defines key terms; and (6)
addresses other important issues
affecting clarity and general
draftsmanship under any guidelines
issued by the Attorney General. Section
3(c) of Executive Order 12988 requires
Executive agencies to review regulations
in light of applicable standards in
sections 3(a) and 3(b) to determine
whether they are met or it is
unreasonable to meet one or more of
them. DOE has completed the required
review and determined that, to the
extent permitted by law, the proposed
rule meets the relevant standards of
Executive Order 12988.
G. Review Under the Unfunded
Mandates Reform Act of 1995
Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA) requires
each Federal agency to assess the effects
of Federal regulatory actions on State,
local, and Tribal governments and the
private sector. Public Law 104–4, sec.
201 (codified at 2 U.S.C. 1531). For a
proposed regulatory action likely to
result in a rule that may cause the
expenditure by State, local, and Tribal
governments, in the aggregate, or by the
private sector of $100 million or more
in any one year (adjusted annually for
inflation), section 202 of UMRA requires
a Federal agency to publish a written
statement that estimates the resulting
costs, benefits, and other effects on the
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national economy. (2 U.S.C. 1532(a), (b))
The UMRA also requires a Federal
agency to develop an effective process
to permit timely input by elected
officers of State, local, and Tribal
governments on a proposed ‘‘significant
intergovernmental mandate,’’ and
requires an agency plan for giving notice
and opportunity for timely input to
potentially affected small governments
before establishing any requirements
that might significantly or uniquely
affect them. On March 18, 1997, DOE
published a statement of policy on its
process for intergovernmental
consultation under UMRA. 62 FR
12820. (This policy is also available at
https://energy.gov/gc/office-generalcounsel.) DOE examined this proposed
rule according to UMRA and its
statement of policy and determined that
the rule contains neither an
intergovernmental mandate, nor a
mandate that may result in the
expenditure by State, local, and Tribal
governments, in the aggregate, or by the
private sector, of $100 million or more
in any year. Accordingly, no further
assessment or analysis is required under
UMRA.
H. Review Under the Treasury and
General Government Appropriations
Act, 1999
Section 654 of the Treasury and
General Government Appropriations
Act, 1999 (Pub. L. 105–277) requires
Federal agencies to issue a Family
Policymaking Assessment for any rule
that may affect family well-being. This
rule would not have any impact on the
autonomy or integrity of the family as
an institution. Accordingly, DOE has
concluded that it is not necessary to
prepare a Family Policymaking
Assessment.
I. Review Under Executive Order 12630
Pursuant to Executive Order 12630,
‘‘Governmental Actions and Interference
with Constitutionally Protected Property
Rights,’’ 53 FR 8859 (March 18, 1988),
DOE has determined that this regulation
would not result in any takings that
might require compensation under the
Fifth Amendment to the U.S.
Constitution.
J. Review Under Treasury and General
Government Appropriations Act, 2001
Section 515 of the Treasury and
General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides
for agencies to review most
disseminations of information to the
public under information quality
guidelines established by each agency
pursuant to general guidelines issued by
OMB. OMB’s guidelines were published
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at 67 FR 8452 (Feb. 22, 2002), and
DOE’s guidelines were published at 67
FR 62446 (Oct. 7, 2002). DOE has
reviewed this proposed rule under the
OMB and DOE guidelines and has
concluded that it is consistent with
applicable policies in those guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ‘‘Actions
Concerning Regulations That
Significantly Affect Energy Supply,
Distribution, or Use,’’ 66 FR 28355 (May
22, 2001), requires Federal agencies to
prepare and submit to OIRA at OMB, a
Statement of Energy Effects for any
proposed significant energy action. A
‘‘significant energy action’’ is defined as
any action by an agency that
promulgates or is expected to lead to
promulgation of a final rule, and that:
(1) Is a significant regulatory action
under Executive Order 12866, or any
successor order; and (2) is likely to have
a significant adverse effect on the
supply, distribution, or use of energy; or
(3) is designated by the Administrator of
OIRA as a significant energy action. For
any proposed significant energy action,
the agency must give a detailed
statement of any adverse effects on
energy supply, distribution, or use
should the proposal be implemented,
and of reasonable alternatives to the
action and their expected benefits on
energy supply, distribution, and use.
This regulatory action, which would
develop a conversion factor to amend
the energy conservation standards for
consumer and certain commercial water
heaters in light of new test procedures
is not a significant regulatory action
under Executive Order 12866 or any
successor order. Moreover, it would not
have a significant adverse effect on the
supply, distribution, or use of energy,
nor has it been designated as a
significant energy action by the
Administrator of OIRA. Therefore, it is
not a significant energy action, and,
accordingly, DOE has not prepared a
Statement of Energy Effects for this
rulemaking.
L. Review Under Section 32 of the
Federal Energy Administration Act of
1974
Under section 301 of the Department
of Energy Organization Act (Pub. L. 95–
91; 42 U.S.C. 7101 et seq.), DOE must
comply with all laws applicable to the
former Federal Energy Administration,
including section 32 of the Federal
Energy Administration Act of 1974
(Pub. L. 93–275), as amended by the
Federal Energy Administration
Authorization Act of 1977 (Pub. L. 95–
70). (15 U.S.C. 788; FEAA) Section 32
essentially provides in relevant part
E:\FR\FM\14APP2.SGM
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Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
that, where a proposed rule authorizes
or requires use of commercial standards,
the notice of proposed rulemaking must
inform the public of the use and
background of such standards. In
addition, section 32(c) requires DOE to
consult with the Attorney General and
the Chairman of the Federal Trade
Commission (FTC) concerning the
impact of the commercial or industry
standards on competition.
This proposed rule to implement
conversion factors between the existing
water heaters test procedure and the
amended test procedure does not
incorporate testing methods contained
in commercial standards.
V. Public Participation
asabaliauskas on DSK5VPTVN1PROD with NOTICES
A. Submission of Comments
DOE will accept comments, data, and
information regarding this proposed
rule no later than the date provided in
the DATES section at the beginning of
this proposed rule. Interested parties
may submit comments, data, and other
information using any of the methods
described in the ADDRESSES section at
the beginning of this document.
Submitting comments via
www.regulations.gov. The
www.regulations.gov Web page will
require you to provide your name and
contact information. Your contact
information will be viewable to DOE
Building Technologies staff only. Your
contact information will not be publicly
viewable except for your first and last
names, organization name (if any), and
submitter representative name (if any).
If your comment is not processed
properly because of technical
difficulties, DOE will use this
information to contact you. If DOE
cannot read your comment due to
technical difficulties and cannot contact
you for clarification, DOE may not be
able to consider your comment.
However, your contact information
will be publicly viewable if you include
it in the comment itself or in any
documents attached to your comment.
Any information that you do not want
to be publicly viewable should not be
included in your comment, nor in any
document attached to your comment.
Otherwise, persons viewing comments
will see only first and last names,
organization names, correspondence
containing comments, and any
documents submitted with the
comments.
Do not submit to www.regulations.gov
information for which disclosure is
restricted by statute, such as trade
secrets and commercial or financial
information (hereinafter referred to as
Confidential Business Information
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(CBI)). Comments submitted through
www.regulations.gov cannot be claimed
as CBI. Comments received through the
Web site will waive any CBI claims for
the information submitted. For
information on submitting CBI, see the
Confidential Business Information
section.
DOE processes submissions made
through www.regulations.gov before
posting. Normally, comments will be
posted within a few days of being
submitted. However, if large volumes of
comments are being processed
simultaneously, your comment may not
be viewable for up to several weeks.
Please keep the comment tracking
number that www.regulations.gov
provides after you have successfully
uploaded your comment.
Submitting comments via email, hand
delivery/courier, or mail. Comments and
documents submitted via email, hand
delivery/courier, or mail also will be
posted to www.regulations.gov. If you
do not want your personal contact
information to be publicly viewable, do
not include it in your comment or any
accompanying documents. Instead,
provide your contact information in a
cover letter. Include your first and last
names, email address, telephone
number, and optional mailing address.
The cover letter will not be publicly
viewable as long as it does not include
any comments.
Include contact information each time
you submit comments, data, documents,
and other information to DOE. If you
submit via mail or hand delivery/
courier, please provide all items on a
CD, if feasible, in which case it is not
necessary to submit printed copies. No
telefacsimiles (faxes) will be accepted.
Comments, data, and other
information submitted to DOE
electronically should be provided in
PDF (preferred), Microsoft Word or
Excel, WordPerfect, or text (ASCII) file
format. Provide documents that are not
secured, that are written in English, and
that are free of any defects or viruses.
Documents should not contain special
characters or any form of encryption
and, if possible, they should carry the
electronic signature of the author.
Campaign form letters. Please submit
campaign form letters by the originating
organization in batches of between 50 to
500 form letters per PDF or as one form
letter with a list of supporters’ names
compiled into one or more PDFs. This
reduces comment processing and
posting time.
Confidential Business Information.
Pursuant to 10 CFR 1004.11, any person
submitting information that he or she
believes to be confidential and exempt
by law from public disclosure should
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20141
submit via email, postal mail, or hand
delivery/courier two well-marked
copies: one copy of the document
marked ‘‘confidential’’ including all the
information believed to be confidential,
and one copy of the document marked
‘‘non-confidential’’ with the information
believed to be confidential deleted.
Submit these documents via email or on
a CD, if feasible. DOE will make its own
determination about the confidential
status of the information and treat it
according to its determination.
Factors of interest to DOE when
evaluating requests to treat submitted
information as confidential include: (1)
A description of the items; (2) whether
and why such items are customarily
treated as confidential within the
industry; (3) whether the information is
generally known by or available from
other sources; (4) whether the
information has previously been made
available to others without obligation
concerning its confidentiality; (5) an
explanation of the competitive injury to
the submitting person which would
result from public disclosure; (6) when
such information might lose its
confidential character due to the
passage of time; and (7) why disclosure
of the information would be contrary to
the public interest.
It is DOE’s policy that all comments
may be included in the public docket,
without change and as received,
including any personal information
provided in the comments (except
information deemed to be exempt from
public disclosure).
B. Issues on Which DOE Seeks Comment
Although DOE welcomes comments
on any aspect of this proposal, DOE is
particularly interested in receiving
comments and views of interested
parties concerning the following issues:
1. Has DOE identified all of the water
heaters requiring a conversion from the
old test procedures for consumer and
commercial water heaters to the new
test procedure for the uniform test
method for measuring the energy
consumption of water heaters?
2. Are the proposed analytical
methods appropriate for the conversion
factor analysis?
3. Is the proposed regression method
appropriate for the conversion factor
analysis?
4. How do manufacturers specify
whether a water heater is short or tall?
Is there any criteria that could be
applied to compare short and tall
designs across all manufacturers?
5. Is the proposed percentage
difference method appropriate for the
derivation of energy conservation
E:\FR\FM\14APP2.SGM
14APP2
20142
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
10 CFR Part 429
Confidential business information,
Energy conservation, Household
appliances, Imports, Reporting and
recordkeeping requirements.
10 CFR Part 430
Administrative practice and
procedure, Confidential business
information, Energy conservation,
Household appliances, Imports,
Incorporation by reference,
Intergovernmental relations, Small
businesses.
10 CFR Part 431
Administrative practice and
procedure, Confidential business
information, Test procedures,
Incorporation by reference, Reporting
and recordkeeping requirements.
Issued in Washington, DC, on March 27,
2015.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy
Efficiency, Energy Efficiency and Renewable
Energy.
For the reasons stated in the
preamble, DOE is proposing to amend
parts 429, 430, and 431 of Chapter II,
Subchapter D of Title 10, Code of
Federal Regulations, as set forth below:
PART 429—CERTIFICATION,
COMPLIANCE, AND ENFORCEMENT
FOR CONSUMER PRODUCTS AND
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
1. The authority citation for part 429
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317.
2. Section 429.17 is revised to read as
follows:
■
and, x is the sample mean; n is the
number of samples; and xi is the ith
sample;
Or,
(2) The upper 95-percent confidence
limit (UCL) of the true mean divided by
1.10, where:
And xis the sample mean; s is the
sample standard deviation; n is the
number of samples; and t0.95 is the t
statistic for a 95-percent one-tailed
confidence interval with n-1 degrees of
freedom (from Appendix A).
and
(B) Any represented value of the
uniform energy factor, energy factor, or
other measure of energy consumption of
a basic model for which consumers
would favor higher values shall be less
than or equal to the lower of:
(1) The mean of the sample, where:
Or,
(2) The lower 95-percent confidence
limit (LCL) of the true mean divided by
0.90, where:
And xis the sample mean; s is the
sample standard deviation; n is the
number of samples; and t0.95 is the t
statistic for a 95-percent one-tailed
confidence interval with n-1 degrees of
freedom (from Appendix A).
(2) For basic models initially certified
before July 13, 2015 (using either the
energy factor test procedure contained
in Appendix E to Subpart B of 10 CFR
part 430 of the January 1, 2015 edition
of the Code of Federal Regulations or
the thermal efficiency and standby loss
test procedures contained in 10 CFR
431.106 of the January 1, 2015 edition
of the Code of Federal Regulations, in
conjunction with applicable sampling
provisions), manufacturers must:
(i) Conduct testing for the uniform
energy factor, in conjunction with the
applicable sampling provisions of this
paragraph;
(ii) Apply an AEDM in accordance
with 10 CFR 429.70; or
(iii) Calculate the uniform energy
factor by applying the following
mathematical conversion factors to the
previously certified value of energy
factor as follows. Representations of
uniform energy factor based on a
calculation using this mathematical
conversion factor must be equal to the
uniform energy factor value resulting
from the application of the appropriate
equation below.
(A) The applicable mathematical
conversion factors are as follows:
Distinguishing criteria
Consumer Gas-fired Water Heater .........................
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Product class
Non-Condensing, Standard NOX ..........................
Non-Condensing, Low NOX ..................................
Non-Condensing, Ultra-Low NOX .........................
Condensing ...........................................................
Consumer Oil-fired Water Heater ...........................
N/A .........................................................................
Consumer Electric Water Heater ............................
Electric Resistance ................................................
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E:\FR\FM\14APP2.SGM
Conversion factor *
New
UEF
New
UEF
New
UEF
New
UEF
New
UEF
New
UEF
FHR = 1.0085 * FHREx
= 0.4736 + 0.2726 * UEFWHAM
FHR = 4.6894 = 0.9112 * FHREx
= ¥0.0126 + 0.9966 * UEFWHAM
FHR = 2.9267 + 0.8882 * FHREx
= 0.2673 + 0.5811 * UEFWHAM
FHR = ¥0.7072 + 0.9724 * FHREx
= 0.0409 + 0.9164 * UEFWHAM
FHR = 1.1018 * FHREx
= ¥0.0945 + 1.1185 * UEFWHAM
FHR = 11.9239 + 0.789 * FHREx
= 0.1227 + 0.8673 * UEFWHAM
14APP2
EP14AP15.022</GPH>
List of Subjects
and, x is the sample mean; n is the
number of samples; and xi is the ith
sample;
EP14AP15.021</GPH>
The Secretary of Energy has approved
publication of this notice of proposed
rulemaking.
EP14AP15.020</GPH>
VI. Approval of the Office of the
Secretary
Water heaters.
(a) Determination of represented
value.
(1) As of July 13, 2015, manufacturers
must determine the represented value
for each new basic model of water
heater by applying an AEDM in
accordance with 10 CFR 429.70 or by
testing for the uniform energy factor, in
conjunction with the applicable
sampling provisions as follows:
(i) If the represented value is
determined through testing, the general
requirements of 10 CFR 429.11 are
applicable; and
(ii) For each basic model selected for
testing, a sample of sufficient size shall
be randomly selected and tested to
ensure that—
(A) Any represented value of the
estimated annual operating cost or other
measure of energy consumption of a
basic model for which consumers would
favor lower values shall be greater than
or equal to the higher of:
(1) The mean of the sample, where:
EP14AP15.019</GPH>
§ 429.17
standards based on the updated test
procedure?
20143
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
Product class
Distinguishing criteria
Conversion factor *
Heat Pump ............................................................
Tabletop Water Heater ...........................................
N/A .........................................................................
Instantaneous Gas-fired Water Heater ...................
N/A .........................................................................
Instantaneous Electric Water Heater ......................
N/A .........................................................................
Residential-Duty Commercial Gas-fired Water
Heater.
Residential-Duty Commercial Oil-fired Water Heater.
N/A .........................................................................
N/A .........................................................................
New
UEF
New
UEF
New
UEF
New
UEF
New
UEF
New
UEF
FHR = ¥2.3440 + 0.9856 * FHREx
= ¥1.1235 + 1.5485 * EF
FHR = 11.9239 + 0.7879 * FHREx
= 0.1227 + 0.8673 * UEFWHAM
Max GPM = 1.1467 * Max GPMEx
= 0.0783 + 0.9052 * UEFmodel
Max GPM = 1.1467 * Max GPMEx
= 1.0079 * UEFmodel
FHR = 39.8144 + 1.0226 * Q
= 0.1413 + 0.7300 * UEFWHAM
FHR = 39.8144 + 1.0226 * Q
= 0.1413 + 0.7300 * UEFWHAM
*FHREX = current first-hour rating.
Max GPMEX = current max GPM rating.
Q = nameplate input rate, in kBtu/hr.
UEFWHAM = the UEF predicted based on either the WHAM equation (for consumer storage water heaters) or the modified WHAM (for residential-duty commercial water heaters, as defined in the sub-paragraphs below).
UEFmodel = the UEF predicted based on the analytical model developed by DOE (for consumer instantaneous water heaters).
(B) Calculate UEFWHAM (for consumer
storage water heaters and residentialduty commercial storage water heaters)
and UEFmodel (for consumer
instantaneous water heaters) as follows:
(1) For consumer storage water
heaters:
Where a, b, c, and d are coefficients
based on the applicable draw pattern as
specified in the table below; EF is the
current energy factor rating; hr is the
current recovery efficiency rating in
decimal form; and P is the input rating
in Btu/h.
(2) For consumer instantaneous water
heaters:
Where hr is the current recovery
efficiency rating expressed in decimal
form and A and B are coefficients
dependent upon the applicable draw
pattern as specified in the table below.
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Draw pattern
A
Very
Small ...
Low .........
Medium ...
High ........
5514.2
20954
30328
46319
B
170.2
262.4
290.9
294.0
(3) For residential-duty commercial
water heaters:
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56095146
56095146
56095146
56095146
12884892499
48962591496
70866908744
108233096990
Where, Et is the existing thermal
efficiency rating; SL is the existing
standby loss rating in Btu/h; and C1 is
a coefficient as specified in the table
below based on the applicable draw
pattern.
Draw pattern
C1
Very Small ............................
Low .......................................
Medium .................................
High ......................................
3.575
9.408
6.500
4.256
x
x
x
x
10¥3
10¥4
10¥4
10¥4
(3) Any represented value of the rated
storage volume must be equal to the
mean of the measured storage volumes
of all the units within the sample.
(4) Any represented value of first-hour
rating or maximum gallons per minute
(GPM) must be equal to the mean of the
measured first-hour ratings or measured
maximum GPM ratings, respectively, of
all the units within the sample.
(b) Certification reports. (1) The
requirements of 10 CFR 429.12 are
applicable to water heaters; and
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c
8930623
33936368
49118427
75017235
d
15125743368
57477824799
83191588525
127056244293
(2) Pursuant to 10 CFR 429.12(b)(13),
a certification report shall include the
following public product-specific
information:
(i) For storage-type water heater basic
models tested for energy factor and
rated pursuant to 10 CFR
429.17(a)(2)(iii): Energy factor, uniform
energy factor, rated storage volume (gal),
first-hour rating (gal), and recovery
efficiency (percent);
(ii) For storage-type water heater basic
models tested for uniform energy factor
and rated pursuant to 10 CFR
429.17(a)(1) or 10 CFR 429.17(a)(2)(i)
through (ii): Uniform energy factor,
rated storage volume in gallons (gal),
first-hour rating (gal), and recovery
efficiency (percent);
(iii) For instantaneous-type water
heater basic models tested for energy
factor and rated pursuant to 10 CFR
429.17(a)(2)(iii): Energy factor, uniform
energy factor, rated storage volume (gal),
maximum gallons per minute, and
recovery efficiency (percent); and
E:\FR\FM\14APP2.SGM
14APP2
EP14AP15.025</GPH>
Very Small ...............................................................................
Low ..........................................................................................
Medium ....................................................................................
High ..........................................................................................
b
EP14AP15.024</GPH>
a
EP14AP15.023</GPH>
Draw pattern
20144
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
asabaliauskas on DSK5VPTVN1PROD with NOTICES
and, x is the sample mean; n is the
number of samples; and xi is the ith
sample;
Or,
(2) The upper 95-percent confidence
limit (UCL) of the true mean divided by
1.10, where:
And, x is the sample mean; s is the
sample standard deviation; n is the
number of samples; and t0.95 is the t
statistic for a 95-percent one-tailed
confidence interval with n-1 degrees of
freedom (from Appendix A).
and
(B) Any represented value of the
uniform energy factor, energy factor, or
other measure of energy consumption of
a basic model for which consumers
would favor higher values shall be less
than or equal to the lower of:
(1) The mean of the sample, where:
VerDate Sep<11>2014
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§ 429.44 Commercial water heating
equipment.
(a) For residential-duty commercial
water heaters, determine representations
as provided in 10 CFR 429.17(a).
*
*
*
*
*
(c) * * *
(2) * * *
(vii) Residential-duty commercial gasfired and oil-fired storage water heaters
tested for thermal efficiency and
standby loss and rated pursuant to 10
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§ 429.44 Commercial water heating
equipment.
*
*
*
*
*
(c) * * *
(2) * * *
(vii) Residential-duty commercial gasfired and oil-fired storage water heaters:
Uniform energy factor, rated storage
volume (gal), first-hour rating (gal), and
recovery efficiency (percent).
*
*
*
*
*
PART 430—ENERGY CONSERVATION
PROGRAM FOR CONSUMER
PRODUCTS
6. The authority citation for part 430
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6309; 28 U.S.C.
2461 note.
7. Section 430.23 is amended by
revising paragraph (e) to read as follows:
■
§ 430.23 Test procedures for the
measurement of energy and water
consumption.
*
*
*
*
*
(e) Water Heaters. (1) For water
heaters tested using energy factor:
(i) The estimated annual operating
cost for water heaters tested in terms of
energy factor shall be—
(A) For a gas or oil water heater, the
product of the annual energy
consumption, determined according to
section 6.1.8 or 6.2.5 of appendix E to
subpart B of 10 CFR part 430 of the
January 1, 2015 edition of the Code of
Federal Regulations, times the
representative average unit cost of gas or
oil, as appropriate, in dollars per Btu as
provided by the Secretary. The resulting
product shall be rounded off to the
nearest dollar per year.
E:\FR\FM\14APP2.SGM
14APP2
EP14AP15.029</GPH>
(a) Determination of represented
value. (1) Manufacturers must
determine the represented value for
each water heater by applying an AEDM
in accordance with 10 CFR 429.70 or by
testing for the uniform energy factor, in
conjunction with the applicable
sampling provisions as follows:
(i) If the represented value is
determined through testing, the general
requirements of 10 CFR 429.11 are
applicable; and
(ii) For each basic model selected for
testing, a sample of sufficient size shall
be randomly selected and tested to
ensure that—
(A) Any represented value of the
estimated annual operating cost or other
measure of energy consumption of a
basic model for which consumers would
favor lower values shall be greater than
or equal to the higher of:
(1) The mean of the sample, where:
And x is the sample mean; s is the
sample standard deviation; n is the
number of samples; and t0.95 is the t
statistic for a 95-percent one-tailed
confidence interval with n-1 degrees of
freedom (from Appendix A).
(2) Any represented value of the rated
storage volume must be equal to the
mean of the measured storage volumes
of all the units within the sample.
(3) Any represented value of first-hour
rating or maximum gallons per minute
(GPM) must be equal to the mean of the
measured first-hour ratings or measured
maximum GPM ratings, respectively, of
all the units within the sample.
(b) Certification reports. (1) The
requirements of 10 CFR 429.12 are
applicable to water heaters; and
(2) Pursuant to 10 CFR 429.12(b)(13),
a certification report shall include the
following public product-specific
information:
(i) For storage-type water heater basic
models: Uniform energy factor, rated
storage volume in gallons (gal), firsthour rating (gal), and recovery efficiency
(percent);
(ii) For instantaneous-type water
heater basic models: Uniform energy
factor, rated storage volume (gal),
maximum gallons per minute, and
recovery efficiency (percent); and
(iii) For instantaneous-type water
heater basic models: Uniform energy
factor, rated storage volume (gal),
maximum gallons per minute, and
recovery efficiency (percent).
■ 4. Section 429.44 is amended by:
■ a. Revising paragraph (a) introductory
text;
■ b. Adding new paragraphs (c)(2)(vii)
and (viii);
The revisions and additions read as
follows:
EP14AP15.028</GPH>
Water heaters.
CFR 429.17(a)(2)(iii): Thermal efficiency
in percent (%), maximum standby loss
in British thermal units per hour (Btu/
h), uniform energy factor, rated storage
volume (gal), and the nameplate input
rate in British thermal units per hour
(Btu/h).
(viii) Residential-duty commercial
gas-fired and oil-fired storage water
heaters tested for uniform energy factor
and rated pursuant to 10 CFR
429.17(a)(1) or 10 CFR 429.17(a)(2)(i)
through (ii): Uniform energy factor,
rated storage volume (gal), first-hour
rating (gal), and recovery efficiency
(percent).
*
*
*
*
*
■ 5. Section 429.44 is further revised,
effective [date one year after publication
of final rule], to read as follows:
■ a. Removing paragraph (c)(2)(vii);
■ b. Redesignating paragraph (c)(2)(viii)
as (c)(2)(vii); and
■ c. Revising newly redesignated
paragraph (c)(2)(vii) to read as follows:
EP14AP15.027</GPH>
§ 429.17
and, x is the sample mean; n is the
number of samples; and xi is the ith
sample;
Or,
(2) The lower 95-percent confidence
limit (LCL) of the true mean divided by
0.90, where:
EP14AP15.026</GPH>
(iv) For instantaneous-type water
heater basic models tested for uniform
energy factor and rated pursuant to 10
CFR 429.17(a)(1) or 10 CFR
429.17(a)(2)(i) through (ii): Uniform
energy factor, rated storage volume (gal),
maximum gallons per minute, and
recovery efficiency (percent).
■ 3. Section 429.17 is further revised,
effective [date one year after publication
of final rule], to read as follows:
20145
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
(B) For an electric water heater, the
product of the annual energy
consumption, determined according to
section 6.1.8 or 6.2.5 of appendix E to
subpart B to 10 CFR part 430 of the
January 1, 2015 edition of the Code of
Federal Regulations, times the
representative average unit cost of
electricity in dollars per kilowatt-hour
as provided by the Secretary, divided by
3412 Btu per kilowatt-hour. The
resulting quotient shall be rounded off
to the nearest dollar per year.
(ii) For an individual test, the tested
energy factor for a water heater shall be
determined by section 6.1.7 or 6.2.4 of
appendix E to subpart B of 10 CFR part
430 of the January 1, 2015 edition of the
Code of Federal Regulations, rounded
off to the nearest 0.01.
(2) For water heaters tested using
uniform energy factor:
(i) The estimated annual operating
cost shall be:
(A) For a gas or oil water heater, the
sum of: The product of the annual gas
or oil energy consumption, determined
according to section 6.1.10 or 6.2.7 of
appendix E of this subpart, times the
representative average unit cost of gas or
oil, as appropriate, in dollars per Btu as
provided by the Secretary; plus the
product of the annual electric energy
consumption, determined according to
section 6.1.9 or 6.2.6 of appendix E of
this subpart, times the representative
average unit cost of electricity in dollars
per kilowatt-hour as provided by the
Secretary. The resulting sum shall be
rounded off to the nearest dollar per
year.
(B) For an electric water heater, the
product of the annual energy
consumption, determined according to
section 6.1.9 or 6.2.6 of appendix E of
this subpart, times the representative
average unit cost of electricity in dollars
per kilowatt-hour as provided by the
Secretary. The resulting product shall be
rounded off to the nearest dollar per
year.
(ii) For an individual test, the tested
uniform energy factor for a water heater
shall be determined by section 6.1.7 or
6.2.4 of appendix E of this subpart,
rounded to the nearest 0.01.
*
*
*
*
*
■ 8. Section 430.32 is amended by
revising paragraph (d) to read as
follows:
§ 430.32 Energy and water conservation
standards and their compliance dates.
*
*
*
*
*
(d) Water heaters. The energy factor of
each basic model of water heater shall
not be less than the following:
Product class
Rated storage
volume
Draw pattern
Gas-fired Storage ............................................
≥ 20 gal and ≤ 55 gal ......................................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
All ..........................
All ..........................
< 55 gal and ≤ 100 gal ...................................
Oil-fired Storage ..............................................
≤ 50 gal ...........................................................
Electric Storage ...............................................
≥ 20 gal and ≤ 55 gal ......................................
< 55 gal and ≤ 120 gal ...................................
Tabletop Storage .............................................
≥ 20 gal and ≤ 100 gal ....................................
Gas-fired Instantaneous ..................................
Electric Instantaneous .....................................
< 2 gal .............................................................
< 2 gal .............................................................
Uniform energy factor as
of July 13, 2015*
0.3263–(0.0019
0.5891–(0.0019
0.6326–(0.0013
0.7128–(0.0025
0.5352–(0.0007
0.7375–(0.0009
0.7704–(0.0010
0.7980–(0.0010
0.2267–(0.0014
0.4867–(0.0006
0.6016–(0.0012
0.6529–(0.0005
0.8268–(0.0002
0.9393–(0.0004
0.9683–(0.0007
0.9656–(0.0004
1.2701–(0.0011
1.9137–(0.0011
2.0626–(0.0011
2.1858–(0.0011
0.6808–(0.0022
0.8770–(0.0012
0.9063–(0.0009
0.9302–(0.0006
0.8036–(0.0019
0.9192–(0.0013
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
*Vr is rated storage volume.
*
*
*
*
*
asabaliauskas on DSK5VPTVN1PROD with NOTICES
PART 431—ENERGY EFFICIENCY
PROGRAM FOR CERTAIN
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
9. The authority citation for part 431
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317.
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19:01 Apr 13, 2015
10. In § 431.106 revise paragraph (b)
to read as follows:
■
Jkt 235001
§ 431.106 Uniform test method for the
measurement of energy efficiency of
commercial water heaters and hot water
supply boilers (other than commercial heat
pump water heaters).
*
PO 00000
*
*
Frm 00031
*
Fmt 4701
(b) Testing and Calculations.
Determine the energy efficiency of each
class of equipment by conducting the
applicable test procedure(s), set forth in
the three rightmost columns of the
following table:
*
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14APP2
20146
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
TABLE 1 TO § 431.106—TEST PROCEDURES FOR COMMERCIAL WATER HEATERS AND HOT WATER SUPPLY BOILERS
(OTHER THAN COMMERCIAL HEAT PUMP WATER HEATERS)
Test procedure
required for compliance on and after
Equipment type
Energy efficiency
descriptor
Test procedure
Residential-Duty Commercial Water Heater.
Gas-fired Storage and
Instantaneous
Water Heaters and
Hot Water Supply
Boilers.
Uniform Energy Factor
10 CFR Part 430,
Subpart B, Appendix E.
Use test set-up,
equipment, and procedures in subsection labeled
‘‘Method of Test’’ of
ANSI Z21.10.3–
2011**, Exhibit G1.
Use test set-up,
equipment, and procedures in subsection labeled
‘‘Method of Test’’ of
ANSI Z21.10.3–
2011**, Exhibit G2.
ANSI Z21.10.3–
2011**, Exhibit G1.
July 13, 2015.
Use test set-up,
equipment, and procedures in subsection labeled
‘‘Method of Test’’ of
ANSI Z21.10.3–
2011**, Exhibit G2.
Use test set-up,
equipment, and procedures in subsection labeled
‘‘Method of Test’’ of
ANSI Z21.10.3–
2011**, Exhibit G2.
May 13, 2013.
Thermal Efficiency .....
Standby Loss .............
Oil-fired Storage and
Instantaneous
Water Heaters and
Hot Water Supply
Boilers.
Thermal Efficiency .....
Standby Loss .............
asabaliauskas on DSK5VPTVN1PROD with NOTICES
Electric Storage and
Instantaneous
Water Heaters.
Standby Loss .............
May 13, 2013 .............
May 13, 2013 .............
May 13, 2013 .............
May 13, 2013 .............
With these additional stipulations
A. For all products, the duration of the standby loss test shall be until whichever of the
following occurs first after you begin to
measure the fuel and/or electric consumption: (1) The first cut-out after 24 hours or
(2) 48 hours, if the water heater is not in
the heating mode at that time.
B. For oil and gas products, the standby loss
in Btu per hour must be calculated as follows: SL (Btu per hour) = S (% per hour) ×
8.25 (Btu/gal-F) × Measured Volume (gal)
× 70 (degrees F).
C. For oil-fired products, apply the following
in conducting the thermal efficiency and
standby loss tests: (1) Venting Requirements—Connect a vertical length of flue
pipe to the flue gas outlet of sufficient
height so as to meet the minimum draft
specified by the manufacturer. (2) Oil Supply—Adjust the burner rate so that: (a)
The hourly Btu input rate lies within ±2
percent of the manufacturer’s specified
input rate, (b) the CO2 reading shows the
value specified by the manufacturer, (c)
smoke in the flue does not exceed No. 1
smoke as measured by the procedure in
ASTM–D2156–80 (reference for guidance
only, see § 431.104), and (d) fuel pump
pressure lies within ±10 percent of manufacturer’s specifications.
D. For electric products, apply the following
in conducting the standby loss test: (1) Assume that the thermal efficiency (Et) of
electric water heaters with immersed heating elements is 98 percent. (2) Maintain
the electrical supply voltage to within ±5
percent of the center of the voltage range
specified on the water heater nameplate.
(3) If the set up includes multiple adjustable thermostats, set the highest one first
to yield a maximum water temperature in
the specified range as measured by the
topmost tank thermocouple. Then set the
lower thermostat(s) to yield a maximum
mean tank temperature within the specified range.
E. Install water-tube water heaters as shown
in Figure 2, ‘‘Arrangement for Testing
Water-tube Type Instantaneous and Circulating Water Heaters.’’
** Incorporated by reference, see § 431.105.
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19:01 Apr 13, 2015
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14APP2
20147
Federal Register / Vol. 80, No. 71 / Tuesday, April 14, 2015 / Proposed Rules
■ 11. Section 431.110 is revised to read
as follows:
§ 431.110 Energy conservation standards
and their effective dates.
Each commercial storage water heater,
instantaneous water heater, unfired hot
water storage tank and hot water supply
Product
boiler 1 (except for residential-duty
commercial water heaters) must meet
the applicable energy conservation
standard level(s) as follows:
Energy conservation standard a (products manufactured
on and after October 29, 2003) b
Size
Minimum thermal efficiency
Electric storage water heaters .........................................
Gas-fired storage water heaters ......................................
Oil-fired storage water heaters ........................................
Gas-fired instantaneous water heaters and hot water
supply boilers.
Oil-fired instantaneous water heaters and hot water
supply boilers.
Maximum standby loss c
All .......................................
≤155,000 Btu/hr .................
>155,000 Btu/hr .................
≤155,000 Btu/hr .................
>155,000 Btu/hr .................
<10 gal ..............................
N/A .....................................
80% ...................................
80% ...................................
78% ...................................
78% ...................................
80% ...................................
0.30 + 27/Vm (%/hr)
Q/800 + 110(Vr)1⁄2 (Btu/hr)
Q/800 + 110(Vr)1⁄2 (Btu/hr)
Q/800 + 110(Vr)1⁄2 (Btu/hr)
Q/800 + 110(Vr)1⁄2 (Btu/hr)
N/A
≥10 gal ...............................
<10 gal ..............................
80% ...................................
80% ...................................
Q/800 + 110(Vr)1⁄2 (Btu/hr)
N/A
≥10 gal ...............................
78% ...................................
Q/800 + 110(Vr)1⁄2 (Btu/hr)
Product
Size
Minimum thermal insulation
Unfired hot water storage tank ........................................
All .......................................
R–12.5.
aV is the measured storage volume and V is the rated volume, both
m
r
b For hot water supply boilers with a capacity of less than 10 gallons:
in gallons. Q is the nameplate input rate in Btu/hr.
(1) the standards are mandatory for products manufactured on and after
October 21, 2005, and (2) products manufactured prior to that date, and on or after October 23, 2003, must meet either the standards listed in
this table or the applicable standards in subpart E of this part for a ‘‘commercial packaged boiler.’’
c Water heaters and hot water supply boilers having more than 140 gallons of storage capacity need not meet the standby loss requirement if
(1) the tank surface area is thermally insulated to R–12.5 or more, (2) a standing pilot light is not used and (3) for gas or oil-fired storage water
heaters, they have a fire damper or fan assisted combustion.
Each residential-duty commercial
water heater, as defined in 10 CFR
431.102, must meet the applicable
energy conservation standard level as
follows:
Product class
Draw pattern
Gas-fired Storage ..........................................................................................................................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Oil-fired Storage ............................................................................................................................
Uniform energy factor*
0.3261–(0.0006
0.5219–(0.0008
0.5585–(0.0006
0.6044–(0.0005
0.3206–(0.0006
0.5577–(0.0019
0.6027–(0.0019
0.5446–(0.0018
x
x
x
x
x
x
x
x
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
* Vr is the rated storage volume.
[FR Doc. 2015–07932 Filed 4–13–15; 8:45 am]
asabaliauskas on DSK5VPTVN1PROD with NOTICES
BILLING CODE 6450–01–P
1Any packaged boiler that provides service water,
that meets the definition of ‘‘commercial packaged
VerDate Sep<11>2014
19:01 Apr 13, 2015
Jkt 235001
boiler’’ in subpart E of this part, but does not meet
the definition of ‘‘hot water supply boiler’’ in
PO 00000
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Fmt 4701
Sfmt 9990
subpart G, must meet the requirements that apply
to it under subpart E.
E:\FR\FM\14APP2.SGM
14APP2
]]>Agencies
[Federal Register Volume 80, Number 71 (Tuesday, April 14, 2015)]
[Proposed Rules]
[Pages 20115-20147]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2015-07932]
[[Page 20115]]
Vol. 80
Tuesday,
No. 71
April 14, 2015
Part III
Department of Energy
-----------------------------------------------------------------------
10 CFR Parts 429, 430, and 431
Energy Conservation Program for Consumer Products and Certain
Commercial and Industrial Equipment: Test Procedures for Consumer and
Commercial Water Heaters; Proposed Rule
Federal Register / Vol. 80 , No. 71 / Tuesday, April 14, 2015 /
Proposed Rules
[[Page 20116]]
-----------------------------------------------------------------------
DEPARTMENT OF ENERGY
10 CFR Parts 429, 430, and 431
[EERE-2015-BT-TP-0007]
RIN 1904-AC91
Energy Conservation Program for Consumer Products and Certain
Commercial and Industrial Equipment: Test Procedures for Consumer and
Commercial Water Heaters
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking.
-----------------------------------------------------------------------
SUMMARY: As required by the Energy Policy and Conservation Act of 1975
(EPCA), as amended, the U.S. Department of Energy (DOE) proposes to
establish a mathematical conversion factor for the purpose of
translating efficiency ratings for water heaters under the test method
currently in effect to the ratings under the amended test method
promulgated by DOE in a final rule published on July 11, 2014
(hereinafter referred to as the ``the July 2014 final rule'').
Compliance with the amended test procedure is required beginning on the
later of: one year after the publication of a final rule that
establishes a mathematical conversion factor, or December 31, 2015.
This rulemaking document proposes a mathematical conversion factor
which may be used to convert the existing efficiency ratings under the
current Federal test procedure to efficiency ratings under the test
procedure adopted in the July 2014 final rule for water heater basic
models manufactured, tested and certified prior to the compliance date
of the amended test procedure. The amended test procedure applies to
all covered consumer water heaters and the covered commercial water
heating equipment with residential applications defined in the July
2014 final rule as a ``residential-duty commercial water heater.'' In
addition, this document proposes amendments to the minimum energy
conservation standards for consumer water heaters and residential-duty
commercial water heaters to account for the impact of the new metric,
but does not alter the stringency of the existing energy conservation
standards. While DOE has not planned a public meeting to discuss this
proposal, DOE is willing to consider a request to hold a meeting.
DATES: Comments: DOE will accept comments, data, and information
regarding this notice of proposed rulemaking (NOPR) no later than May
14, 2015. See section V, ``Public Participation,'' for details.
ADDRESSES: All comments submitted must identify the NOPR for the
Conversion Factor for Test Procedures for Consumer and Certain
Commercial Water Heaters, and provide docket number EERE-2015-BT-TP-
0007 and/or RIN 1904-AC91. Interested persons are encouraged to submit
comments using the Federal eRulemaking Portal at www.regulations.gov.
Follow the instructions for submitting comments. Alternatively,
interested persons may submit comments by any of the following methods:
Email: ConsumerCommWaterHtrs2015TP0007@ee.doe.gov. Include
the docket number and/or RIN in the subject line of the message. Submit
electronic comments in WordPerfect, Microsoft Word, PDF, or ASCII file
format, and avoid the use of special characters or any form of
encryption.
Postal Mail: Ms. Brenda Edwards, U.S. Department of
Energy, Building Technologies Office, Mailstop EE-5B, 1000 Independence
Avenue SW., Washington, DC 20585-0121. If possible, please submit all
items on a compact disc (CD), in which case it is not necessary to
include printed copies.
Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department
of Energy, Building Technologies Office, 950 L'Enfant Plaza SW., 6th
Floor, Washington, DC 20024. Telephone: (202) 586-2945. If possible,
please submit all items on a CD, in which case it is not necessary to
include printed copies.
No telefacsimilies (faxes) will be accepted. For detailed
instructions on submitting comments and additional information on the
rulemaking process, see section V of this document (Public
Participation).
Docket: The docket is available for review at www.regulations.gov,
including Federal Register notices, comments, and other supporting
documents/materials. All documents in the docket are listed in the
www.regulations.gov index. However, not all documents listed in the
index may be publicly available, such as information that is exempt
from public disclosure.
A link to the docket Web page can be found at: https://www.regulations.gov/#!docketDetail;D=EERE-2015-BT-TP-0007. This Web
page contains a link to the docket for this notice of proposed
rulemaking on the www.regulations.gov site. The www.regulations.gov Web
page contains simple instructions on how to access all documents,
including public comments, in the docket. See section V, ``Public
Participation,'' for information on how to submit comments through
www.regulations.gov.
For information on how to submit a comment or review other public
comments and the docket, contact Ms. Brenda Edwards at (202) 586-2945
or by email: Brenda.Edwards@ee.doe.gov.
FOR FURTHER INFORMATION CONTACT: Ms. Ashley Armstrong, 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. Telephone: (202) 586-6590. Email:
Ashley.Armstrong@ee.doe.gov.
Mr. Eric Stas, U.S. Department of Energy, Office of the General
Counsel, GC-33, 1000 Independence Avenue SW., Washington, DC 20585-
0121. Telephone: (202) 586-9507. Email: Eric.Stas@hq.doe.gov.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Authority and Background
II. Summary of the Notice of Proposed Rulemaking
III. Discussion
A. Stakeholder Comments on Other Rulemakings
B. Scope
1. Test Procedure and Energy Conservation Standards Coverage
2. Units on the Market
C. Potential Approaches for Developing Conversions
1. Background Regarding Changes to Existing Test Procedures
2. Analytical Methods
3. Empirical Regression
D. Testing Conducted for the Mathematical Conversion
1. Consumer Water Heater Testing
2. Residential-Duty Commercial Water Heater Testing
E. Testing Results and Analysis of Test Data
1. Impact of Certain Water Heater Attributes on Efficiency
Ratings
2. Conversion Factor Derivation
3. Energy Conservation Standard Derivation
F. Certification and Labeling Issues
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
[[Page 20117]]
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
V. Public Participation
A. Submission of Comments
B. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary
I. Authority and Background
Title III Part B \1\ of the Energy Policy and Conservation Act of
1975 (``EPCA'' or, ``the Act''), Public Law 94-163 (42 U.S.C. 6291-
6309, as codified) sets forth a variety of provisions designed to
improve energy efficiency and established the Energy Conservation
Program for Consumer Products Other Than Automobiles.\2\ These include
consumer water heaters, one subject of this document. (42 U.S.C.
6292(a)(4)) Title III, Part C \3\ of EPCA, Public Law 94-163 (42 U.S.C.
6311-6317, as codified), added by Public Law 95-619, Title IV, Sec.
441(a), established the Energy Conservation Program for Certain
Industrial Equipment, which includes the commercial water heating
equipment that is another subject of this rulemaking. (42 U.S.C.
6311(1)(K))
---------------------------------------------------------------------------
\1\ For editorial reasons, upon codification in the U.S. Code,
Part B was redesignated Part A.
\2\ All references to EPCA in this document refer to the statute
as amended through the American Energy Manufacturing Technical
Corrections Act (AEMTCA), Public Law 112-210 (Dec. 18, 2012).
\3\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
Under EPCA, energy conservation programs generally consist of four
parts: (1) Testing; (2) labeling; (3) establishing Federal energy
conservation standards; and (4) certification and enforcement
procedures. The testing requirements consist of test procedures that
manufacturers of covered products and equipment must use as the basis
for certifying to DOE that their products and equipment comply with the
applicable energy conservation standards adopted under EPCA, and for
making other representations about the efficiency of those products.
(42 U.S.C. 6293(c); 42 U.S.C. 6295(s); 42 U.S.C. 6314) Similarly, DOE
must use these test procedures to determine whether such products and
equipment comply with any relevant standards promulgated under EPCA.
(42 U.S.C. 6295(s))
EPCA, as codified, contains what is known as an ``anti-
backsliding'' provision, which prevents the Secretary from prescribing
any amended standard that either increases the maximum allowable energy
use or decreases the minimum required energy efficiency of a covered
product. (42 U.S.C. 6295(o)(1)) Also, the Secretary may not prescribe
an amended or new standard if interested persons have established by a
preponderance of the evidence that the standard is likely to result in
the unavailability in the United States of any covered product type (or
class) of performance characteristics (including reliability),
features, sizes, capacities, and volumes that are substantially the
same as those generally available in the United States. (42 U.S.C.
6295(o)(4))
EPCA prescribed energy conservation standards for consumer water
heaters (42 U.S.C. 6295(e)(1)), and directed DOE to conduct further
rulemakings to determine whether to amend these standards (42 U.S.C.
6295(e)(4)(A)-(B)). DOE notes that under 42 U.S.C. 6295(m), the agency
must periodically review its already established energy conservation
standards for a covered product. Under this requirement, the next
review that DOE would need to conduct must occur no later than six
years from the issuance of a final rule establishing or amending a
standard for a covered product.
On April 16, 2010, DOE published a final rule (hereinafter referred
to as the ``April 2010 final rule'') that amended the energy
conservation standards for all classes of consumer water heaters,
except for tabletop and electric instantaneous water heaters, for which
the existing energy conservation standards were left in place. 75 FR
20112. The standards adopted by the April 2010 final rule are shown
below in Table I.1. These standards will apply to all water heater
products listed in Table I.1 and manufactured in, or imported into, the
United States on or after April 16, 2015, for all classes, except for
tabletop and electric instantaneous. For these latter two classes,
compliance with these standards has been required since April 15, 1991.
55 FR 42162 (Oct. 17, 1990). Current energy conservation standards for
consumer water heaters can be found in DOE's regulations at 10 CFR
430.32(d).
Table I.1--Energy Conservation Standards for Consumer Water Heaters
----------------------------------------------------------------------------------------------------------------
Product class Rated storage volume *** Energy factor **
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage..................... >=20 gal and <=55 gal........ 0.675-(0.0015 x Vs)
>55 gal and <=100 gal........ 0.8012-(0.00078 x Vs)
Oil-fired Storage..................... <=50 gal..................... 0.68-(0.0019 x Vs)
Electric Storage...................... >=20 gal and <=55 gal........ 0.96-(0.0003 x Vs)
>55 gal and <=120 gal........ 2.057-(0.00113 x Vs)
Tabletop *............................ >=20 gal and <=120 gal....... 0.93-(0.00113 x Vs)
Gas-fired Instantaneous............... <2 gal....................... 0.82-(0.0019 x Vs)
Electric Instantaneous *.............. <2 gal....................... 0.93-(0.00132 x Vs)
----------------------------------------------------------------------------------------------------------------
*Tabletop and electric instantaneous standards were not updated by the April 2010 final rule.
** Vs is the ``Rated Storage Volume'' which equals the water storage capacity of a water heater (in gallons), as
specified by the manufacturer.
*** Rated Storage Volume limitations result from either a lack of test procedure coverage or from divisions
created by DOE when adopting standards. The division at 55 gallons for gas-fired and electric storage water
heaters was established in the April 16, 2010 final rule amending energy conservation standards. 75 FR 20112.
The other storage volume limitations shown in this table are a result of test procedure applicability, and are
discussed in the July 2014 final rule. 79 FR 40542 (July 11, 2014).
The initial Federal energy conservation standards and test
procedures for commercial water heating equipment were added to EPCA as
an amendment made by the Energy Policy Act of 1992 (EPACT). (42 U.S.C.
6313(a)(5)) These initial energy conservation standards corresponded to
the efficiency levels contained in the American Society of Heating,
Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 90.1
(ASHRAE Standard 90.1) in effect on October 24, 1992. The statute
provided that if the efficiency levels in ASHRAE Standard 90.1 were
amended after October 24, 1992, the Secretary must establish an amended
uniform national standard at new minimum levels for each equipment type
specified in ASHRAE Standard 90.1, unless DOE determines, through a
rulemaking supported by clear and convincing evidence, that national
standards more
[[Page 20118]]
stringent than the new minimum levels would result in significant
additional energy savings and be technologically feasible and
economically justified. (42 U.S.C. 6313(a)(6)(A)(ii)(I)-(II)) DOE
issued the most recent final rule for commercial water heating
equipment on January 12, 2001 (hereinafter, the ``January 2001 final
rule''), which adopted the amended energy conservation standards at
levels equivalent to efficiency levels in ASHRAE Standard 90.1, as it
was revised in October 1999. 66 FR 3336. The current standards for
commercial water heating equipment are presented in Table I.2 and may
be found in DOE's regulations at 10 CFR 431.110.
Table I.2--Energy Conservation Standards for Commercial Water Heating Equipment
----------------------------------------------------------------------------------------------------------------
Energy conservation standard *
------------------------------------------------------------
Minimum
Equipment Size thermal
efficiency Maximum standby loss \c\
(%)
----------------------------------------------------------------------------------------------------------------
Electric storage water heaters. All............... N/A 0.30 + 27/Vm (%/hr)
Gas-fired storage water heaters <=155,000 Btu/hr.. 80 Q/800 + 110(Vr) 1, 2 (Btu/hr)
>155,000 Btu/hr... 80 Q/800 + 110(Vr) 1, 2 (Btu/hr)
Oil-fired storage water heaters <=155,000 Btu/hr.. 78 Q/800 + 110(Vr) 1, 2 (Btu/hr)
>155,000 Btu/hr... 78 Q/800 + 110(Vr) 1, 2 (Btu/hr)
Gas-fired instantaneous water <10 gal........... 80 N/A
heaters and hot water supply
boilers **.
>=10 gal.......... 80 Q/800 + 110(Vr) 1, 2 (Btu/hr)
Oil-fired instantaneous water <10 gal........... 80 N/A
heaters and hot water supply
boilers **.
>=10 gal.......... 78 Q/800 + 110(Vr) 1, 2 (Btu/hr)
----------------------------------------------------------------------------------------------------------------
Equipment Size Minimum thermal insulation
----------------------------------------------------------------------------------------------------------------
Unfired hot water storage tank. All............... R-12.5
----------------------------------------------------------------------------------------------------------------
* Vm is the measured storage volume, and Vr is the rated volume, both in gallons. Q is the nameplate input rate
in Btu/hr.
** For hot water supply boilers with a capacity of less than 10 gallons: (1) The standards are mandatory for
products manufactured on and after October 21, 2005, and (2) products manufactured prior to that date, and on
or after October 23, 2003, must meet either the standards listed in this table or the applicable standards in
subpart E of this part for a ``commercial packaged boiler.''
*** Water heaters and hot water supply boilers having more than 140 gallons of storage capacity need not meet
the standby loss requirement if: (1) The tank surface area is thermally insulated to R-12.5 or more; (2) a
standing pilot light is not used; and (3) for gas or oil-fired storage water heaters, they have a fire damper
or fan-assisted combustion.
On December 18, 2012, the American Energy Manufacturing Technical
Corrections Act (AEMTCA), Public Law 112-210, was signed into law. In
relevant part, it amended EPCA to require that DOE publish a final rule
establishing a uniform efficiency descriptor and accompanying test
methods for covered consumer water heaters and commercial water heating
equipment within one year of the enactment of AEMTCA. (42 U.S.C.
6295(e)(5)(B)) The final rule must replace the current energy factor,
thermal efficiency, and standby loss metrics with a uniform efficiency
descriptor. (42 U.S.C. 6295(e)(5)(C)) The July 2014 final rule
fulfilled these requirements. AEMTCA requires that, beginning one year
after the date of publication of DOE's final rule establishing the
uniform descriptor (i.e., July 13, 2015), the efficiency standards for
the consumer water heaters and residential-duty commercial water
heaters identified in the July 2014 final rule must be denominated
according to the uniform efficiency descriptor established in that
final rule (42 U.S.C. 6295(e)(5)(D)), and that DOE must develop a
mathematical conversion factor for converting the measurement of
efficiency for those water heaters from the test procedures and metrics
currently in effect to the new uniform energy descriptor. (42 U.S.C.
6295(e)(5)(E)(i)-(ii)) Consumer water heaters and residential-duty
commercial water heaters manufactured prior to the effective date of
the final rule (i.e., July 13, 2015) that comply with the efficiency
standards and labeling requirements in effect prior to the final rule
shall be considered to comply with the final rule and with any revised
labeling requirements established by the Federal Trade Commission (FTC)
to carry out the final rule. (42 U.S.C. 6295(e)(5)(K))
AEMTCA also requires that the uniform efficiency descriptor and
accompanying test method apply, to the maximum extent practicable, to
all water-heating technologies currently in use and to future water-
heating technologies. (42 U.S.C. 6295(e)(5)(H)) AEMTCA allows DOE to
provide an exclusion from the uniform efficiency descriptor for
specific categories of otherwise covered water heaters that do not have
residential uses, that can be clearly described, and that are
effectively rated using the current thermal efficiency and standby loss
descriptors. (42 U.S.C. 6295(e)(5)(F))
AEMTCA outlines DOE's various options for establishing a new
uniform efficiency descriptor for water heaters. The options that
AEMTCA provides to DOE include: (1) A revised version of the energy
factor descriptor currently in use; (2) the thermal efficiency and
standby loss descriptors currently in use; (3) a revised version of the
thermal efficiency and standby loss descriptors; (4) a hybrid of
descriptors; or (5) a new approach. (42 U.S.C. 6295(e)(5)(G)) Lastly,
AEMTCA requires that DOE invite stakeholders to participate in the
rulemaking process, and that DOE contract with the National Institute
of Standards and Technology (NIST), as necessary, to conduct testing
and simulation of alternative descriptors identified for consideration.
(42 U.S.C. 6295(e)(5)(I)-(J))
As noted previously, in the July 2014 final rule, DOE amended its
test procedure for consumer and certain commercial water heaters. 79 FR
40542 (July 11, 2014). The July 2014 final rule for consumer and
certain commercial water heaters satisfied the AEMTCA requirements to
develop a uniform efficiency descriptor to replace the existing energy
factor, thermal efficiency and standby loss metrics. The amended test
procedure includes
[[Page 20119]]
provisions for determining the uniform energy factor (UEF), as well as
the annual energy consumption of these products. Furthermore, the
uniform descriptor test procedure can be applied to: (1) Most consumer
water heaters (including certain consumer water heaters that are
covered products under EPCA's definition of ``water heater'' at 42
U.S.C. 6291(27), but that are not addressed by the existing test
method); and (2) to commercial water heaters that have residential
applications. The major modifications to the existing DOE test
procedure to establish the uniform descriptor test method included the
use of multiple draw patterns and different draw patterns, and changes
to the set-point temperature. In addition, DOE expanded the scope of
the test method to include test procedure provisions that are
applicable to water heaters with storage volumes between 2 gallons (7.6
L) and 20 gallons (76 L), and to clarify applicability to electric
instantaneous water heaters. DOE also established a new equipment class
and corresponding definition for ``residential-duty commercial water
heater.''
This rulemaking will satisfy the requirements of AEMTCA to develop
a mathematical conversion factor for converting the measurement of
efficiency for covered water heaters from the test procedures and
metrics currently in effect to the new uniform energy descriptor. (42
U.S.C. 6295(e)(5)(E))
II. Summary of the Notice of Proposed Rulemaking
This notice of proposed rulemaking proposes to establish a
mathematical conversion factor between the current rated values under
the existing water heaters test procedures (i.e., energy factor, first-
hour rating, maximum gallons per minute (GPM) rating, thermal
efficiency, standby loss), and the amended test procedure for the
uniform efficiency descriptor (i.e., UEF and first-hour rating or
maximum GPM rating), which was established in the July 2014 final rule.
As discussed previously, the water heater test procedure was updated to
be more representative of conditions encountered in the field
(including modifications to both the test conditions and the draw
patterns) and to expand the scope of the test procedure to apply to
certain commercial and consumer water heaters that are currently not
addressed by the test procedure.
The mathematical conversion factor required by AEMTCA is a bridge
between the efficiency ratings obtained through testing under the
existing test procedures and those obtained under the uniform
efficiency descriptor test procedure published in the July 2014 final
rule. Therefore, the mathematical conversion factor will only apply to
products and equipment covered by the existing test procedure, as
products and equipment that are not covered by the existing test method
would not have ratings to be converted. Certain water heater types are
not covered by the mathematical conversion factor, either because they
are not covered by the uniform efficiency descriptor established by the
July 2014 final rule (e.g., commercial heat pump water heaters), or
because they are not covered by DOE's existing test procedure (e.g.,
water heaters with storage volumes between 2 and 20 gallons). The water
heater types that are and are not covered by the mathematical
conversion factor are discussed in detail in section III.B of this
notice of proposed rulemaking.
To help develop the mathematical conversion factor, DOE conducted a
series of tests on the types of water heaters included within the scope
of this rulemaking (i.e., those described in section III.B and that
pass the minimum standards for consumer \4\ and commercial water
heaters). An investigation of DOE's Compliance Certification Management
System (CCMS) and the Air-Conditioning, Heating, and Refrigeration
Institute's (AHRI) water-heating databases found that certain types of
water heaters are not available for purchase on the market; these units
are discussed in section III.B. As there are no existing water heaters
in these product classes, and the purpose of the conversion factor is
to convert the efficiency ratings of existing water heaters, DOE did
not include these water heaters in its analysis for the mathematical
conversion factor.
---------------------------------------------------------------------------
\4\ DOE published a final rule on April 16, 2010, that will
require compliance with amended energy conservation standards
beginning on April 16, 2015. 75 FR 20112. DOE focused the testing of
consumer water heaters on units that would comply with the amended
standards.
---------------------------------------------------------------------------
DOE selected 72 water heaters for testing, including: 43 consumer
storage units, 22 consumer instantaneous units, and 7 commercial
residential-duty storage units. Units were selected to represent the
range of rated values available on the market (i.e., storage volume,
input rate, first-hour rating, maximum GPM, recovery efficiency, energy
factor, thermal efficiency, and standby loss). DOE used data obtained
from testing, along with analytical methods described in section III.C,
to calculate the conversion factors described in this document. DOE
investigated several approaches to derive these conversion factors,
which are discussed in detail in section III.C of this notice of
proposed rulemaking. DOE developed different conversion factors for
determining first-hour rating, maximum GPM, and UEF based on the
existing ratings for consumer and residential-duty commercial water
heaters, which can be found in section III.E.
DOE then used the conversion factors to derive minimum energy
conservation standards based on the UEF, as shown in Table II.1 and
Table II.2. The proposed standards based on UEF are neither more nor
less stringent than the existing standards for consumer water heaters
based on energy factor (as amended by the April 2010 final rule) and
for commercial water-heating equipment based on the thermal efficiency
and standby loss metrics. The methodology for deriving the proposed UEF
standards is discussed in detail in section III.E.3 of this notice of
proposed rulemaking.
Table II.1--Proposed Consumer Water Heater Energy Conservation Standards
----------------------------------------------------------------------------------------------------------------
Rated storage
Product class volume Draw pattern Uniform energy factor *
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage............. >=20 gal and <=55 Very Small............... 0.3263-(0.0019 x Vr)
gal.
Low...................... 0.5891-(0.0019 x Vr)
Medium................... 0.6326-(0.0013 x Vr)
High..................... 0.7128-(0.0025 x Vr)
>55 gal and <=100 Very Small............... 0.5352-(0.0007 x Vr)
gal.
Low...................... 0.7375-(0.0009 x Vr)
Medium................... 0.7704-(0.0010 x Vr)
High..................... 0.7980-(0.0010 x Vr)
Oil-fired Storage............. <=50 gal......... Very Small............... 0.2267-(0.0014 x Vr)
[[Page 20120]]
Low...................... 0.4867-(0.0006 x Vr)
Medium................... 0.6016-(0.0012 x Vr)
High..................... 0.6529-(0.0005 x Vr)
Electric Storage.............. >=20 gal and <=55 Very Small............... 0.8268-(0.0002 x Vr)
gal.
Low...................... 0.9393-(0.0004 x Vr)
Medium................... 0.9683-(0.0007 x Vr)
High..................... 0.9656-(0.0004 x Vr)
>55 gal and <=120 Very Small............... 1.2701-(0.0011 x Vr)
gal.
Low...................... 1.9137-(0.0011 x Vr)
Medium................... 2.0626-(0.0011 x Vr)
High..................... 2.1858-(0.0011 x Vr)
Tabletop Storage.............. >=20 gal and Very Small............... 0.6808-(0.0022 x Vr)
<=100 gal.
Low...................... 0.8770-(0.0012 x Vr)
Medium................... 0.9063-(0.0009 x Vr)
High..................... 0.9302-(0.0006 x Vr)
Gas-fired Instantaneous....... <2 gal........... All...................... 0.8036-(0.0019 x Vr)
Electric Instantaneous........ <2 gal........... All...................... 0.9192-(0.0013 x Vr)
----------------------------------------------------------------------------------------------------------------
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as
specified by the manufacturer.
Table II.2--Proposed Residential-Duty Commercial Water Heater Energy Conservation Standards
----------------------------------------------------------------------------------------------------------------
Product class Draw pattern Uniform energy factor
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage.................... Very Small..................... 0.3261 - (0.0006 x Vr)
Low............................ 0.5219 - (0.0008 x Vr)
Medium......................... 0.5585 - (0.0006 x Vr)
High........................... 0.6044 - (0.0005 x Vr)
Oil-fired Storage.................... Very Small..................... 0.3206 - (0.0006 x Vr)
Low............................ 0.5577 - (0.0019 x Vr)
Medium......................... 0.6027 - (0.0019 x Vr)
High........................... 0.6446 - (0.0018 x Vr)
----------------------------------------------------------------------------------------------------------------
*Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as
specified by the manufacturer.
EPCA requires that a covered water heater be considered to comply
with the July 2014 final rule on and after July 13, 2015 (the effective
date of the July 2014 final rule) and with any revised labeling
requirements established by the Federal Trade Commission to carry out
the July 2014 final rule if the covered water heater was manufactured
prior to July 13, 2015, and complied with the efficiency standards and
labeling requirements in effect prior to July 13, 2015. (42 U.S.C.
6295(e)(5)(K)) Upon the effective date of the final rule establishing
the mathematical conversion factor (this rulemaking), compliance with
energy conservation standards will be exclusively determined based on
the standards as defined in terms of UEF, which will be established by
this rulemaking. DOE has tentatively concluded that there will be three
possible compliance paths available to manufacturers for basic models
of consumer water heaters that were certified before July 13, 2015:
(1) Convert the certified rating for energy factor obtained using
the test procedure contained in Appendix E to subpart B of 10 CFR part
430 of the January 1, 2015 edition of the CFR along with the applicable
sampling provisions in 10 CFR part 429 from energy factor to uniform
energy factor using the applicable mathematical conversion factor; or
(2) Conduct testing using the test procedure contained at Appendix
E to subpart B of 10 CFR part 430, effective July 13, 2015, along with
the applicable sampling provisions in 10 CFR part 429; or
(3) Where permitted, apply an alternative efficiency determination
method (AEDM) pursuant to 10 CFR 429.70 to determine the represented
efficiency of basic models for those categories of consumer water
heaters where the ``tested basic model'' was tested using the test
procedure contained at Appendix E to subpart B of 10 CFR part 430,
effective July 13, 2015.
Similarly, DOE has tentatively concluded that there will be three
possible compliance paths available to manufacturers for basic models
of commercial residential-duty water heaters that were certified before
July 13, 2015:
(1) Convert the certified rating for thermal efficiency and standby
loss obtained using the test procedure contained in 10 CFR 431.106 of
the January 1, 2015 edition of the CFR along with the applicable
sampling provisions in part 429 from thermal efficiency and standby
loss to uniform energy factor using the applicable mathematical
conversion factor; or
(2) Conduct testing using the test procedure at 10 CFR 431.106,
effective July 13, 2015, along with the applicable sampling provisions
in part 429; or
(3) Where permitted, apply an alternative efficiency determination
method (AEDM) pursuant to 10 CFR 429.70 to determine the represented
efficiency of basic models for those categories of commercial water
heaters where the ``tested basic model'' was tested using the test
procedure at 10 CFR 431.106, effective July 13, 2015.
After July 13, 2015, all new basic models (previously uncertified)
must be rated using the new test procedure either by testing or by an
AEDM, where allowed. All water heaters subject to the new test
procedure adopted by the July 2014 final rule must be rated and
certified in terms of UEF. DOE will assess compliance based upon the
energy conservation standards expressed in terms of UEF as developed in
this rulemaking. One year after the final rule in this rulemaking is
published, all water heaters subject to the new UEF test procedure must
be
[[Page 20121]]
rated and certified based on testing using the UEF test procedure or an
AEDM, which is based on the UEF test procedure, where allowed. A
summary of the options and requirements at various key dates is shown
in the table below.
Table II.3--Summary of Key Dates and Requirements
------------------------------------------------------------------------
Description of date Date Requirements
------------------------------------------------------------------------
Test Procedure Effective July 13, 2015....... For new basic models
Date. introduced into
commerce on or
after July 13,
2015, manufacturers
must begin to test
and represent
efficiency using
the UEF metric
pursuant to the UEF
test procedure and
sampling plan (or
an AEDM that is
based on the UEF
test procedure,
where allowed).
Conversion Factor Effective Date of publication For basic models
Date. of the conversion certified using the
factor final rule EF metric or
in the Federal thermal efficiency
Register. and/or standby loss
metrics prior to
July 13, 2015,
manufacturers must
transition all of
their
representations to
UEF either by
applying the
conversion
equations or by
using the UEF test
procedure and
sampling plan (or
an AEDM that is
based on the UEF
test procedure,
where allowed).
Conversion Factor Ending One year after All basic models
Date. publication of must be rated in
conversion factor terms of UEF using
final rule. the UEF test
procedure and
sampling plan or an
AEDM that is based
on the UEF test
procedure, where
allowed.
------------------------------------------------------------------------
III. Discussion
A. Stakeholder Comments on Other Rulemakings
During the rulemaking process to develop the uniform efficiency
descriptor test procedure, comments were received from stakeholders in
reference to the derivation and applicability of the conversion factor.
DOE deferred discussion of and response to those comments until such
time as they could be addressed in this rulemaking.
In response to the test procedure request for information (RFI \5\)
published on January 11, 2013, DOE received seven written comments
related to the conversion factor from the following interested parties:
AHRI, A.O. Smith Corporation (A.O. Smith), Edison Electric Institute
(EEI), Heat Transfer Products Inc. (HTP), the National Renewable Energy
Laboratory (NREL), the Northwest Energy Efficiency Alliance (NEEA), and
a joint comment on behalf of a number of environmental groups and
efficiency advocates submitted by the American Council for an Energy-
Efficient Economy (ACEEE).\6\ These comments are discussed immediately
below.
---------------------------------------------------------------------------
\5\ 78 FR 2340.
\6\ ACEEE submitted a joint comment on behalf of ACEEE, the
Appliance Standards Awareness Project (ASAP), the Alliance to Save
Energy (ASE), the National Consumer Law Center (NCLC), the National
Resources Defense Council (NRDC), the Northwest Power and
Conservation Council (NPCC), and the Northeast Energy Efficiency
Partnerships (NEEP).
---------------------------------------------------------------------------
NREL stated that there is not a simple conversion factor that will
work across all systems, but suggested an application of the Water
Heater Analysis Model (WHAM) \7\ to assist DOE in developing the
conversion factor for storage water heaters. (NREL, EERE-2011-BT-TP-
0042-0029 at p. 4) The joint commenters supported the use of a ``good-
enough'' mathematical conversion method to express existing ratings in
terms of the new uniform descriptor and urged DOE to test a sample of
existing products to validate the algorithmic conversion method. (Joint
comment, EERE-2011-BT-TP-0042-0035 at p. 4) HTP commented that the most
exact approach would be to conduct an empirical analysis using curve
fitting to actual test data, although the commenter acknowledged that
there is not sufficient time for manufacturers to obtain this
information and for the Department to then correlate and analyze the
data. (HTP, EERE-2011-BT-TP-0042-0041 at p. 3)
---------------------------------------------------------------------------
\7\ Lutz, Jim, Camilla D. Whitehead, Alex Lekov, David
Winiarski, and Greg Rosenquist, WHAM: A Simplified Energy
Consumption Equation for Water Heaters, Proc. of 1998 ACEEE Summer
Study on Energy Efficiency in Buildings. Vol. 1. 171-83. Print.
---------------------------------------------------------------------------
Regarding the derivation of updated energy conservation standards
using the new uniform descriptor, AHRI and A.O. Smith commented that
DOE should not simply test multiple units to determine an average
difference between the current and new ratings and use that value to
convert the ratings. (AHRI, EERE-2011-BT-TP-0042-0033 at p. 4; A.O.
Smith, EERE-2011-BT-TP-0042-0034 at p. 3) NEEA commented that
considering the limited laboratory capacity to test all water heaters
under the revised method of test, DOE should assume that all water
heaters that comply with current standards will also comply after the
implementation of the new metrics. (NEEA, EERE-2011-BT-TP-0042-0037 at
p. 6) EEI commented that the conversion factor should not make
currently existing standards more stringent and should only be based on
point-of-use metrics to be consistent with Federal law. (EEI, EERE-
2011-BT-TP-0042-0040 at p. 2)
In response to the test procedure NOPR \8\ published on November 4,
2013, DOE received three additional written comments related to the
conversion factor from: AHRI, Bradford White Corporation (BWC) and a
joint comment submitted on behalf of a number of environmental groups
and efficiency advocates by ACEEE.\9\ AHRI and BWC suggested model
types to test and urged DOE to release a schedule and process for the
development of the conversion factor as soon as possible. (AHRI, EERE-
2011-BT-TP-0042-0075 at p. 6-7; BWC, EERE-2011-BT-TP-0042-0061 at p. 7)
AHRI suggested two categories to be considered in the conversion factor
rulemaking: water heater type and storage volume. BWC expanded on the
list of categories supplied by AHRI by
[[Page 20122]]
including considerations for input capacity, venting options, tank
configuration, NOX emissions, and mobile home certification.
The joint comment suggested that the sensitivity of the energy factor
to draw pattern be investigated and that systematic differences between
``old'' and ``new'' values should be expected for several technologies.
(Joint Comment, EERE-2011-BT-TP-0042-0077 at p. 2)
---------------------------------------------------------------------------
\8\ 78 FR 66202.
\9\ ACEEE submitted a joint comment on behalf of ACEEE, ASAP,
ASE, Consumers Union (CU), NCLC, NRDC and NEEP.
---------------------------------------------------------------------------
DOE has considered these comments fully in the development of this
proposed rule. Although discussed in overview here, these comments are
discussed in more detail later in this document as applicable to DOE's
specific decisions regarding the mathematical conversion factor. In
regards to the method of developing the conversion factor, DOE agrees
in principle with the HTP comment that the most exact approach would be
an empirical analysis using a curve-fitting method and actual test
data, because such approach would account for all the changes made in
the new test procedure, without having to make assumptions. However,
DOE notes that the confidence in this empirical approach is dependent
upon sample size and has considered whether the approach can feasibly
be tested and implemented within the time constraints set forth by
AEMTCA. (The curve-fitting method investigated is discussed in section
III.C.3.)
In addition, as suggested by NREL, DOE investigated the use of the
WHAM model to predict water heater efficiency under the new test
procedure parameters, and used the results in the conversion factor
analysis. The methodology for applying WHAM and the results are found
in section III.C.2.c. As suggested in the NOPR joint comment, the
sensitivity of the UEF to draw pattern was investigated by including
the drawn volume in the conversion factor calculations; this approach
is discussed further in section III.C.
In an effort to develop a mathematical conversion factor, DOE
commissioned testing of 72 individual water heaters from various easily
distinguishable water-heating categories under the updated test
procedure. All of the water heaters chosen were found using either the
Compliance Certification Management System (CCMS) or AHRI water heater
databases, where the water heaters included in the databases were
further distinguished based on the suggestions made by AHRI and BWC in
response to the November 2013 water heaters NOPR (78 FR 66202 (Nov. 4,
2013)). The models selected for testing and the parameters examined are
described in more detail in section III.D. These test data were used to
investigate all of the potential conversion factor methods described in
section III.C.
DOE has also carefully considered the comments regarding the
establishment of energy conservation standards using the uniform
efficiency descriptor metric (i.e., UEF). Those comments are discussed
further in section III.E.3.
B. Scope
The purpose of this section is to describe DOE's process for
categorizing water heaters and establishing the range of units to be
considered in this mathematical conversion factor rulemaking. DOE seeks
comment on the scope of the conversion factor. This is identified as
issue 1 in section V.E, ``Issues on Which DOE Seeks Comment.''
1. Test Procedure and Energy Conservation Standards Coverage
To determine the appropriate scope of coverage for the mathematical
conversion factor, DOE first considered the scope of its existing test
procedures and energy conservation standards for consumer and
commercial water heaters. Water heaters that are not currently subject
to the DOE test procedures or standards were not included in the scope
of the conversion factor, as they are not required to be tested and
rated for efficiency under the DOE test method.
a. Consumer Water Heaters
Under the existing regulatory definitions, DOE's current consumer
water heater test procedures and energy conservation standards are not
applicable to gas or electric water heaters with storage tanks that are
at or above 2 gallons (7.6 L) and less than 20 gallons (76 L). In terms
of the high end of the capacity range, the current DOE test procedure
for consumer water heaters only applies to gas-fired water heaters with
storage volumes less than or equal to 100 gallons (380 L), electric
resistance and heat pump storage water heaters with storage volumes
less than or equal to 120 gallons (450 L), and oil-fired water heaters
with storage volumes less than or equal to 50 gallons (190 L). 10 CFR
part 430, subpart B, appendix E, sections 1.12.1, 1.12.2, and 1.12.4.
In the July 2014 final rule, DOE expanded the scope of the water
heater test procedure for the uniform efficiency descriptor to include
water heaters with storage volumes between 2 and 20 gallons and up to
120 gallons. 79 FR 40542, 40547-48 (July 11, 2014).
DOE's current consumer water heater test procedure and energy
conservation standards are not applicable to gas-fired instantaneous
water heaters with input capacities at or below 50,000 Btu/h or at or
above 200,000 Btu/h. 10 CFR part 430, subpart B, appendix E, section
1.7.2. In addition, the existing test procedure and energy conservation
standards are not applicable to gas-fired storage water heaters with
input capacities above 75,000 Btu/h, electric storage water heaters
with input ratings above 12 kW, and oil-fired storage water heaters
with input ratings above 105,000 Btu/h, as models exceeding those
limits would not be classified as consumer water heaters under EPCA.
(42 U.S.C. 6291(27)); 10 CFR part 430, subpart B, appendix E, sections
1.12.1, 1.12.2, and 1.12.4.
In the July 2014 final rule, DOE designed the test procedure so it
is applicable to water heaters with any input capacity. Therefore, the
lower limit for instantaneous water heaters no longer applies. 79 FR
40542, 40548 (July 11, 2014).
As discussed in the July 2014 final rule, definitions were added
for ``electric instantaneous water heater,'' ``gas-fired heat pump
water heater,'' and ``oil-fired instantaneous water heater,'' and the
July 2014 test procedure is applicable to these types of appliances. 79
FR 40542, 40549 (July 11, 2014).
Although there is no definition for ``electric instantaneous water
heater'' in the current test procedure in 10 CFR part 430, subpart B,
Appendix E, an energy conservation standard exists for this type of
water heater. In addition, the current test procedure can be applied to
electric instantaneous water heaters, and manufacturers report energy
factor ratings for these products. For these reasons, DOE has decided
to include electric instantaneous water heaters with rated storage
volumes <2 gallons and rated inputs <=12 kW in the conversion factor
analysis.
DOE has tentatively excluded the consumer water heater products
listed in Table III.1 from consideration for the mathematical
conversion factor due to the lack of an existing Federal test procedure
and rating to be converted.
[[Page 20123]]
Table III.1--Consumer Water Heaters Not Covered by the Mathematical
Conversion Factor
------------------------------------------------------------------------
Description of criteria for
Product class exclusion from conversion
rulemaking
------------------------------------------------------------------------
Gas-fired Storage...................... Rated Storage Volume >=2 gal
and <20 gal or >100 gal and
<=120 gal.
Oil-fired Storage...................... Rated Storage Volume >50 gal.
Electric Storage....................... Rated Storage Volume >=2 gal
and <20 gal.
Tabletop............................... Rated Storage Volume >=2 gal
and <20 gal.
Gas-fired Instantaneous................ Rated Input <= 50,000 Btu/h;
Rated Storage Volume >2 gal.
Electric Instantaneous................. Rated Storage Volume >2 gal.
------------------------------------------------------------------------
b. Commercial Water Heaters
As stated in the July 2014 final rule, DOE excluded from the
uniform efficiency descriptor any specific category of water heater
that does not have a residential use, can be clearly described, and can
be effectively rated using the current thermal efficiency and standby
loss descriptors. 79 FR 40542, 40545 (July 11, 2014). DOE determined
that certain commercial water heaters met these criteria to be excluded
from the uniform efficiency descriptor, and distinguished them from
water heaters that do not meet the criteria by establishing equipment
classes for residential-duty commercial water heaters. Commercial water
heaters meeting the definition of ``residential-duty commercial water
heater'' do not meet the criteria for exclusion, and thus, are included
in the uniform efficiency descriptor while all other commercial water
heaters are not. DOE determined that three criteria would be used to
distinguish residential-duty commercial water heaters from other
commercial water heaters (79 FR 40542, 40547 (July 11, 2014)):
(1) For models requiring electricity, uses single-phase external
power supply;
(2) Is not designed to provide outlet hot water at temperatures
greater than 180[emsp14][deg]F; and
(3) Is not excluded by the limitations regarding rated input and
storage volume presented in Table III.2.
Table III.2--Capacity Limitations for Defining Commercial Water Heaters
Without Residential Applications (i.e., Non-Residential-Duty)
------------------------------------------------------------------------
Indicator of non-residential
Water heater type application
------------------------------------------------------------------------
Gas-fired Storage...................... Rated input >105 kBtu/h; Rated
storage volume >120 gallons.
Oil-fired Storage...................... Rated input >140 kBtu/h; Rated
storage volume >120 gallons.
Electric Storage....................... Rated input >12 kW; Rated
storage volume >120 gallons.
Heat Pump with Storage................. Rated input >15 kW; Rated
current >24 A at a rated
voltage of not greater than
250 V; Rated storage volume
>120 gallons.
Gas-fired Instantaneous................ Rated input >200 kBtu/h; Rated
storage volume >2 gallons.
Electric Instantaneous................. Rated input >58.6 kW; Rated
storage volume >2 gallons.
Oil-fired Instantaneous................ Rated input >210 kBtu/h; Rated
storage volume >2 gallons.
------------------------------------------------------------------------
DOE did not include commercial water-heating equipment that does
not meet the definition of a ``residential-duty commercial water
heater'' in its consideration of the mathematical conversion factor, as
the equipment is not subject to the uniform efficiency descriptor test
procedure. Additionally, DOE notes that there are no electric storage
water heaters that would be considered to be residential-duty
commercial since the qualifications shown in Table II.2 would place an
electric storage water heater in the consumer category. Since there are
no such units, and could not be such units under the applicable
definition, a conversion is unnecessary. DOE is, therefore, not
proposing a conversion factor for residential-duty electric storage
water heaters. DOE also notes that a water heater that meets the
definition of a consumer electric storage water heater must be tested
and rated as a consumer electric storage water heater even if it is
marketed as part of a commercial product line.
As stated in the July 2014 final rule, DOE has determined that
certain commercial equipment including unfired storage tanks, add-on
heat pump water heaters, and hot water supply boilers are not
appropriately rated using the uniform descriptor applicable to other
water heaters, and, thus, will continue to be rated using the existing
metrics. 79 FR 40542, 40547.
Electric instantaneous water heaters are currently subject to the
commercial water heating equipment test procedures but do not have an
associated energy conservation standard. 10 CFR 431.106; 10 CFR
431.110. Because there is no commercial energy conservation standard
for electric instantaneous water heaters, a conversion to the UEF
cannot be made.
2. Units on the Market
As stated in section II, DOE undertook an investigation into the
water-heating units on the market at the time of the publication of the
final rule establishing the UEF test procedure. The AHRI commercial
water heater database along with the CCMS consumer water heater
database were examined to select representative units for testing and
analysis.
DOE's analysis focused on the models that meet the energy
conservation standards contained in the April 2010 final rule, which
will require compliance on April 16, 2015. The storage volume divisions
at 55 gallons in the gas-fired and electric storage product classes, as
established in the April 16, 2010 final rule, represent a divide in
technology. For gas-fired storage units above 55 gallons manufactured
on and after April 16, 2015, the energy conservation standard will be
high enough that current designs can only achieve the required
efficiency through the use of condensing technology.\10\ For electric
storage units with storage volumes above 55 gallons, only heat pump
water heaters currently
[[Page 20124]]
have the ability to reach the April 16, 2015 energy conservation
standard levels. While the UEF test procedure will apply to both
electric and gas units in this range, DOE found that for gas-fired
storage water heaters, there are currently no consumer water heaters
above 55 gallons that would be compliant with the updated standard, so
no units were tested for development of a conversion factor. For
electric storage water heaters, heat pump water heaters meet or exceed
the amended energy conservation standards and, thus, were candidates
for inclusion in the test plan for the conversion factor. There are no
oil-fired instantaneous or oil-fired storage water heaters above 50
gallons available on the market.
---------------------------------------------------------------------------
\10\ In a condensing water heater, the combustion gases are
cooled such that the temperature is reduced below the dew point and
condensation occurs, allowing the latent heat of vaporization to be
captured and improving the efficiency of the heat exchange between
the combustion gases and the water.
---------------------------------------------------------------------------
In reviewing the commercial water heating market, DOE found that
commercial oil-fired instantaneous water heaters are available on the
market but do not meet the definition of ``residential-duty commercial
water heater,'' as they have storage volumes greater than 2 gallons.
DOE found that all commercial gas-fired instantaneous units exceeded
the maximum delivery temperature of 180 [deg]F for residential-duty
commercial water heaters, and, thus, would be regulated using the
existing thermal efficiency and standby loss metrics. DOE also found
that commercial electric instantaneous units which meet the definition
of ``residential-duty commercial water heater'' exist, however, as
stated in section III.B.1.b, no energy conservation standard exists for
these units; therefore a conversion factor was not developed.
Consequently, none of the commercial water heaters identified above
could be tested or examined for use in this rulemaking. In addition, a
conversion factor for these water heaters is not needed because there
are no units in existence with efficiency ratings that can be
converted. However, because a manufacturer may want to design and
produce products in these equipment classes in the future, DOE must
establish energy conservation standards in terms of the UEF metric.
Accordingly, DOE used information gained from other product classes to
establish these energy conservation standards, as discussed in section
III.E.
C. Potential Approaches for Developing Conversions
1. Background Regarding Changes to Existing Test Procedures
a. Consumer Water Heater Test Procedures
Both the current test procedure and the uniform efficiency
descriptor test procedure consist of a delivery capacity test and a 24-
hour simulated-use test. The delivery capacity tests for storage and
instantaneous water heaters are the first-hour rating and maximum GPM
tests, respectively. These tests are largely unchanged from the current
to the new test procedure, except for modifications to account for the
decrease in delivered water temperature from a nominal value of 135
[deg]F to 125 [deg]F. The results of those tests, however, have
implications on the 24-hour simulated-use test under the new test
procedure that are absent under the current test procedure.
In the current test procedure, the delivery capacity has no effect
on the 24-hour simulated-use test, which consists of six hot water
draws, of equivalent volumes, at the start of the test and each of the
first five subsequent hours. The water heater is then in standby mode
for the remainder of the test. In the July 2014 final rule, however,
the delivery capacity determines the draw pattern for the 24-hour
simulated-use test. According to the new test procedure, a water
heater's delivery capacity can be categorized as either very small,
low, medium, or high; these usages are shown below in Table III.3. 79
FR 40542, 40572 (July 11, 2014). These usage categories have an
associated draw pattern prescribed to them during the 24-hour
simulated-use. Depending on the delivery capacity associated with a
water heater, between 9 and 14 hot water draws of various volumes and
flow rates are required.
Table III.3--Delivery Capacity Categorization Criteria
----------------------------------------------------------------------------------------------------------------
First-Hour Rating, gal Maximum GPM, gpm
Draw Pattern ------------------------------------------------------------------- Drawn Volume,
>= < >= < gal
----------------------------------------------------------------------------------------------------------------
Very Small................... 0 18.............. 0 1.7............. 10
Low.......................... 18 51.............. 1.7 2.8............. 38
Medium....................... 51 75.............. 2.8 4............... 55
High......................... 75 No upper limit.. 4 No upper limit.. 84
----------------------------------------------------------------------------------------------------------------
In the existing DOE consumer water heater test procedure, a
temperature of 135 [deg]F 5 [deg]F is used for the set-
point temperature for storage water heaters (measured as the mean tank
temperature) and the delivery temperature for instantaneous water
heaters. In the uniform efficiency descriptor test procedure set forth
in the July 2014 final rule, a temperature of 125 [deg]F 5
[deg]F is used for the set-point temperature for storage water heaters
(measured as the delivery temperature) and the delivery temperature of
instantaneous water heaters. 79 FR 40542, 40554 (July 11, 2014).
b. Commercial Water Heater Test Procedure
The current test procedure for rating commercial water heaters
consists of a steady-state test to determine thermal efficiency and a
test lasting between 24 and 48 hours to measure the standby loss. 77 FR
28996 (May 16, 2012); 10 CFR 431.106. For electric resistance water
heaters, the thermal efficiency is assigned a value of 98 percent in
lieu of testing. The set-point temperature of the water heater is 140
[deg]F 5 [deg]F, and the unit sits in an environment with
an ambient temperature of 75 [deg]F 10 [deg]F. Water is
supplied to the water heater at a temperature of 70 [deg]F
2 [deg]F. Instantaneous water heaters are not required to undergo a
standby loss test.
Under the uniform efficiency descriptor test procedure, commercial
water heaters falling under the ``residential-duty'' category will now
be subject to the first-hour rating or maximum GPM test and simulated-
use tests specified in the previous section (III.C.1.a), with the same
set-point temperature, ambient temperature, and inlet water temperature
as is applied to consumer water heaters.
2. Analytical Methods
For converting existing ratings to ratings under the uniform
efficiency descriptor test method, DOE considered equations based on a
water heater's physical characteristics; these approaches will be
termed analytical methods. The sections below describe
[[Page 20125]]
potential analytical methods for the three key metrics that result from
the uniform efficiency descriptor test method: (1) The maximum GPM; (2)
the first-hour rating; and (3) the UEF. In the discussion immediately
below, DOE introduces key factors that it expects will change ratings
from the existing consumer and commercial water heater test procedures
to the new uniform efficiency descriptor test procedure.
a. Maximum GPM
For flow-activated water heaters, the delivery capacity is
determined by the 10-minute maximum GPM rating test. During this test,
the water heater runs at maximum firing rate to raise the temperature
from its nominal value of 58 [deg]F to the prescribed delivery
temperature. This flow rate is determined by the following equation:
[GRAPHIC] [TIFF OMITTED] TP14AP15.006
where VV is the volumetric flow rate of water, Q is the firing rate,
[eta]r is the recovery efficiency, [rho] is the density of
the delivered water, cp is the specific heat of the
delivered water, Tdel is the delivered water temperature,
and Tin is the inlet water temperature. If it is assumed
that the firing rate and recovery efficiency are the same with water
delivered at 125 [deg]F and 135 [deg]F, then the ratio of the maximum
GPM at 125 [deg]F versus that at 135 [deg]F is determined by the
following equation:
[GRAPHIC] [TIFF OMITTED] TP14AP15.007
Therefore, an analytical conversion from the existing maximum GPM
rating (VVex) for consumer water heaters to the rating under the test
conditions in the uniform efficiency descriptor test method (VVUED) is:
VVUED = 1.147VVex
As discussed in detail in section III.E.2, tests on flow-activated
water heaters showed a change in maximum GPM rating under the uniform
efficiency descriptor test method that correlated well with the above
equation.
b. First-Hour Rating
For water heaters that have a heat source controlled by means other
than sensing flow (e.g., thermostatically-controlled), the delivery
capacity is determined through a first-hour rating test. During this
test, the water heater begins in its fully heated state, and water is
drawn from it at a specified flow rate until the temperature of the
delivered water drops a specified amount. The water heater is then
allowed to recover, and subsequent draws are initiated when the
controller acts to reduce the heat input to particular burners or
heating elements specified in the test procedure. These subsequent
draws are terminated based on the same criterion that is used for the
first draw, namely that the outlet water temperature drops a set amount
of degrees from its maximum value during that draw. When the test
reaches a duration of one hour from the start of the first draw, the
test concludes after the draw termination criterion is reached for the
draw taking place at one hour from the start of the test. If no draw is
occurring at the one hour duration, a draw is initiated and terminated
when the outlet water temperature reaches the termination temperature
of the previous draw, and the test is concluded upon termination of
that draw.
In the uniform efficiency descriptor test procedure, the primary
change that will affect the first-hour rating is the shift from a
nominal delivery temperature of 135 [deg]F to 125 [deg]F and the
accompanying adjustment to the draw termination criterion to a decrease
in delivered water temperature from 25 [deg]F in the current consumer
water heater test method to 15 [deg]F in the uniform efficiency
descriptor test method. Because the initial set-point temperature is
reduced in the uniform efficiency descriptor as compared to the
existing consumer water heater test procedure, less stored thermal
energy will be available at the start of the test. However, this effect
is countered because the lower set-point temperature allows the water
heater to recover quicker (as the water only needs to be heated to a 15
[deg]F temperature rise rather than a 25 [deg]F temperature rise),
thereby allowing subsequent draws to start sooner than they would under
the current test procedure. Thus, due to these offsetting effects, DOE
has observed through testing that sometimes the first-hour rating is
increased when tested under the uniform efficiency descriptor, and
sometimes the rating is decreased. DOE is not aware of any analytical
models that would mathematically represent this behavior, so it has
chosen not to pursue such an approach for converting existing first-
hour ratings to first-hour ratings under the uniform efficiency
descriptor. Rather, as discussed in section III.C.3, DOE chose an
approach based on an empirical regression for converting the first-hour
ratings.
Likewise, DOE is not aware of any analytical method that will
convert rated values of thermal efficiency and standby loss for
residential-duty commercial storage water heaters to a first-hour
rating. Therefore, DOE chose an approach based on empirical regression
for converting existing ratings of residential-duty commercial water
heaters to first-hour ratings.
c. Uniform Energy Factor
A number of changes to the 24-hour simulated-use test will alter
the water heater energy efficiency ratings from the existing water
heater test procedures as compared to the ratings obtained under the
uniform efficiency descriptor test method. Among the key changes that
are expected to alter the efficiency metric for consumer water heaters
are: (1) A different volume of water withdrawn per test; (2) a change
in the draw pattern (i.e., number of draws, flow rates during draws,
timing of draws) applied during the test; (3) reduction of the test
temperature from an average stored temperature of 135 [deg]F to a
delivered water temperature of 125 [deg]F; and (4) removal of the
stipulation to normalize the energy consumption to maintain a
prescribed average water temperature within the storage tank.
Residential-duty commercial water heaters will see a change from the
thermal efficiency and standby loss metrics currently in place to the
UEF, which consists of an entirely new approach for rating efficiency.
i. Consumer Storage Water Heaters
A simple theoretical model for determining the energy consumption
of a storage-type water heater based on key test parameters, termed the
Water Heater Analysis Model (WHAM), was
[[Page 20126]]
presented by Lutz et al.\11\ The equation for the energy input (Q) over
a 24-hour period is determined using the following equation:
---------------------------------------------------------------------------
\11\ Lutz, Jim, Camilla Dunham Whitehead, Alex Lekov, David
Winiarski, and Greg Rosenquist. ``WHAM: A Simplified Energy
Consumption Equation for Water Heaters'' In Proceedings of the 1998
ACEEE Summer Study on Energy Efficiency in Buildings (1998)
(Available at: https://cgec.ucdavis.edu/ACEEE/1998/pdffiles/papers/0114.pdf) (Last accessed October 1, 2014).
[GRAPHIC] [TIFF OMITTED] TP14AP15.008
where [rho] is the density of water, cp is the specific heat
of water, [eta]r is the recovery efficiency, V is the volume
of water delivered per day, UA is the heat loss factor,
Ttank is the average temperature of the water stored within
the tank of a storage water heater, P is the input power to the water
heater in Btu/h, Tamb is the average ambient temperature
during the test, and 24 is the number of hours in the test. This
equation considers the energy required to heat the water that is
delivered by the water heater from the inlet water temperature up to
the delivery temperature and the energy required to make up the heat
lost from the water heater to the surrounding environment. The time
over which this standby energy loss is determined is corrected by the
term with the power in the denominator to account for the fact that
[eta]r, as calculated in the test, accounts for standby
energy loss during periods when heat input to the water is activated.
This calculated energy can then be used to estimate the daily
efficiency, Eff, under a given daily water demand (e.g., that required
during the current EF test or that required during the UEF test):
[GRAPHIC] [TIFF OMITTED] TP14AP15.009
Currently, directories of water heater ratings provide the Eff
(i.e., Energy Factor), P, and [eta]r. Since the EF testing
entails a prescribed Tdel (135 [deg]F), Tin (58
[deg]F), Ttank (135 [deg]F), Tamb (67.5 [deg]F),
and V (64.3 gallons), the two equations can be solved for the two
remaining unknowns, Q and UA. The exception to this approach is heat
pump water heaters. For these units, the reported recovery efficiency
([eta]r) is that of the resistance element inside the water
heater. Since it is expected that the heat pump unit would provide the
majority of the heating during the simulated-use test as opposed to the
resistance element, the required data to use the WHAM model for heat
pump water heaters is not readily available in publicly accessible
directories. For these units, DOE proposes to base the conversion
equation purely on experimental data.
After the equations are solved to determine UA, if one assumes that
the UA and [eta]r do not change under the new test approach,
then the two equations can be solved again (this time inserting the UA
value obtained from solving the previous set of equations) to determine
the values for Q and Eff (i.e., UEF) under the uniform efficiency
descriptor test method using the prescribed values for the uniform
efficiency descriptor test procedure of Tdel (125 [deg]F),
Tin (58 [deg]F), Ttank (125 [deg]F),
Tamb (67.5 [deg]F), and V (varies depending upon draw
pattern).
This formulation entails a number of assumptions. A major
assumption is that the average tank temperature is approximately equal
to the delivered water temperature. As previously noted, the new
procedure does not normalize the average stored water temperature to a
prescribed value, so this estimate may not be completely accurate. Some
water heaters have demonstrated that average tank temperature is below
the typical delivered temperature because of stratification. This
effect is believed to be most pronounced with condensing water heaters.
Other water heaters show some stratification, but the average water
temperature within the tank is typically closer to the delivered water
temperature. Another assumption in this formulation is that the
recovery efficiency and UA values do not change when the water heater
stores water for delivery at 135 [deg]F compared to storing it at 125
[deg]F. While electric resistance water heaters have a prescribed
recovery efficiency of 98 percent, other technologies may see changes
in the recovery efficiency as the temperature drops. For example, the
study by Sparn et al. shows plots of the Coefficient of Performance
(COP), which is one aspect of the recovery efficiency, for heat pump
water heaters.\12\ Their data suggest an increase in COP of
approximately 15 percent with the average tank temperature at 125
[deg]F compared to 135 [deg]F. Data obtained by DOE indicate an
increase in recovery efficiency obtained during the same draw profile
of between 3 and 13 percent, with an average of 8 percent. Data
collected on fossil-fuel-fired water heaters show negligible dependency
of the recovery efficiency on the prescribed tank temperature. The UA
value may change slightly based on higher heat transfer coefficients at
higher temperatures or changes in the thermal conductivity of
insulating materials at higher temperatures. Data collected by DOE
suggest that the UA value decreases 7 percent from 135 [deg]F to 125
[deg]F.
---------------------------------------------------------------------------
\12\ Sparn, B., K. Hudon, and D. Christensen, Laboratory
Performance Evaluation of Residential Integrated Heat Pump Water
Heaters. National Renewable Energy Laboratory (September 2011)
(Available at: https://www.nrel.gov/docs/fy11osti/52635.pdf) (Last
accessed October 1, 2014).
---------------------------------------------------------------------------
For an initial estimate, DOE considered the situation where the UA
and recovery efficiency do not change with temperature. The equations
above can estimate the effects of two key factors that have changed in
the test procedure, namely the volume drawn per day and the delivery
temperature. As more water is delivered, the fraction of energy
required to make up the standby losses compared to the overall energy
required by the water heater is diminished, thereby increasing the
fraction of energy going towards hot delivered water and increasing the
efficiency. The change in set-point temperature appears to have less of
an effect on water heater efficiency, since two competing factors are
at play. With a lower stored water temperature, the standby losses are
decreased, thereby increasing the overall efficiency of the water
heater. The lower delivery temperature, however, means that less energy
is delivered per gallon, so the energy delivered for a given volume
delivered per day is less than that when the water is delivered at 135
[deg]F, thereby decreasing the efficiency of the water heater.
As noted, direct use of this model may not properly account for
changes to the recovery efficiency, UA value, or normalization
procedure for standby heat loss. Therefore, DOE has chosen a two-step
process to convert the existing Energy Factor ratings for consumer
storage water heaters to the UEF. First, using the equations and
assumptions described above, a prediction of the
[[Page 20127]]
efficiency given by WHAM is determined, termed UEFWHAM. This value is
then considered as part of a regression analysis (see section III.C.3)
to obtain a relationship that will convert from EF to UEF. DOE believes
that the use of WHAM will capture the primary effects of changes in the
volume of water delivered per day along with changes in the set-point
temperature. Regression with experimental data will then capture the
effects that may not be fully accounted for by WHAM, such as
differences in the UA value, recovery efficiency, and the change to the
normalization calculation procedure for standby heat loss.
To establish a clear method of applying the analytical model, the
WHAM-based UEF equation and Table III.4, comprising the coefficients
based on draw bin, are presented below. This equation incorporates the
equations and assumptions presented above, where [eta]r and
EF are the recovery efficiency and energy factor, respectively, based
on the current DOE test procedure, and P is the nameplate input rate in
Btu/h. As shown in Table III.4, constants ``a,'' ``b,'' ``c,'' and
``d'' are dependent on the volume of water being drawn.
[GRAPHIC] [TIFF OMITTED] TP14AP15.010
Table III.4--Coefficients for WHAM-based UEF Conversion Factor
----------------------------------------------------------------------------------------------------------------
Draw bin a b c d
----------------------------------------------------------------------------------------------------------------
Very Small...................................... 56095146 12884892499 8930623 15125743368
Low............................................. 56095146 48962591496 33936368 57477824799
Medium.......................................... 56095146 70866908744 49118427 83191588525
High............................................ 56095146 108233096990 75017235 127056244293
----------------------------------------------------------------------------------------------------------------
ii. Consumer Instantaneous Water Heaters
WHAM is not directly applicable to instantaneous water heaters
because it assumes that the water heater loses heat at a constant rate
throughout the day when the heating element is not energized. For
instantaneous water heaters, this modeling approach is inappropriate
since the unit does not store water at an elevated temperature
throughout the day, rather heating water as it flows through the unit.
Instantaneous water heaters instead experience a separate type of
heat loss to the surroundings that sometimes result in Energy Factors
that are below the steady-state thermal efficiency. This loss occurs
when heat that is present in the water heater at the end of a draw
dissipates to the ambient. If a draw is not initiated shortly after the
end of a draw, then most of this heat is lost. If, however, a
subsequent draw starts shortly after a previous draw, some of that heat
is captured in the hot water that is delivered.
DOE attempted to capture these effects in a modified equation that
separately accounts for energy consumption that goes towards supplying
heat to the delivered water and energy consumption that goes towards
heating up the materials making up the water heater:
[GRAPHIC] [TIFF OMITTED] TP14AP15.011
where LF is a loss factor related to the amount of energy stored in the
materials of the water heater and N* is the number of draws from which
heat loss occurs to the environment. LF is approximately equal to the
mass of the material within the water heater times its heat capacity.
N* is not simply the number of draws during the day, since some draws
may occur close together and do not result in total energy loss. To
determine the fraction of energy from a draw that is lost, DOE examined
data from testing that suggested that most heat is lost from tankless
water heaters after about one hour. Using this value, DOE scaled the
energy loss for a draw by the length of the standby time following the
draw. For example, a draw followed by over one hour of standby time
would contribute a value of 1 to N* for that test. A draw followed by
30 minutes of standby time prior to the next draw would contribute a
value of (30 min)/(60 min) = 0.5 to N*. Contributions from each draw in
a test pattern are added to obtain a value for N* for each draw
pattern. For the existing DOE consumer water heater test, N* is 5.64,
as the standby time following each draw is slightly under 60 minutes.
The values for N* for all draw patterns are provided in Table III.5.
Table III.5--Estimate of Number of Draws From Which All Energy From
Water Heater Is Lost to Surroundings
------------------------------------------------------------------------
Draw pattern N*
------------------------------------------------------------------------
Existing Consumer Water Heater Draw Pattern.................... 5.64
Very-Small-Use................................................. 4.36
Low-Use........................................................ 6.72
Medium-Use..................................................... 7.45
High-Use....................................................... 7.53
------------------------------------------------------------------------
DOE attempted this approach by obtaining an estimate of LF from
data obtained during testing of 17 gas instantaneous water heaters
according to the current simulated-use test. (LF could theoretically be
determined for each unit, but some test results showed a recovery
efficiency equal to EF, which would mathematically lead to an infinite
value of LF). A regression of the energy consumption data during these
tests with the quantity multiplying LF in the previous model equation
resulted in a value of LF of 0.679 Btu/[deg]F. Using
[[Page 20128]]
this value to then estimate the energy consumption during the new
simulated-use test resulted in predictions of the UEF. This approach
resulted in a root mean squared error between predicted values and
measured values of 0.027.
Alternatively, a set of regressions, based solely on test data,
were examined to determine the impact of other factors as discussed in
section III.C.3. The best regressions resulted in a mean squared error
of 0.032.
As discussed for consumer storage water heaters in section
III.C.2.c.i, DOE also considered a two-step process to convert the
existing EF ratings to the UEF--first using the equations and
assumptions described above to obtain an analytical prediction of UEF,
then using a regression analysis to obtain a relationship that will
convert from EF to UEF. Based on these results, DOE has chosen to use
the analytical model plus a regression approach for converting EFs for
consumer instantaneous water heaters to UEF. DOE has tentatively
concluded that the assumptions made in the analytical model capture
some key operating characteristics of the instantaneous units, and the
further step to use measured data captures unforeseen issues. Details
on this approach are provided in section III.C.3.
iii. Residential-Duty Commercial Water Heaters
DOE investigated a modified version of WHAM for converting the
thermal efficiency and standby loss metrics for residential-duty
commercial storage water heaters to UEF. The AHRI certification
directory includes the thermal efficiency (Et) and standby
loss (SL). The equation below estimates the energy consumption of a
water heater based on these efficiency metrics:
[GRAPHIC] [TIFF OMITTED] TP14AP15.012
where 70 represents the nominal temperature difference in degrees
Fahrenheit between the tank and ambient during the standby loss test.
By assuming that Ttank equals Tdel, all variables
in the equation above are known, since Et and SL can be
obtained from current ratings and all other variables are specified in
the UEF test procedure for a given projected first-hour rating. The
equation above can be used in combination with the one below to
estimate the UEF for residential-duty storage water heaters
(UEFrd):
[GRAPHIC] [TIFF OMITTED] TP14AP15.013
These equations can be combined to yield the following equation for
converting Et and SL to UEF using the coefficient C1, which
is dependent upon the draw pattern applied during the UEF test, as
provided in Table III.6.
[GRAPHIC] [TIFF OMITTED] TP14AP15.014
Table III.6--Coefficient for Conversion of Commercial Water Heater
Ratings to UEF
------------------------------------------------------------------------
Draw pattern C1
------------------------------------------------------------------------
Very Small.............................................. 3.575 x 10-3
Low..................................................... 9.408 x 10-4
Medium.................................................. 6.500 x 10-4
High.................................................... 4.256 x 10-4
------------------------------------------------------------------------
As was done with consumer water heaters, DOE decided to account for
unforeseen effects observed during testing by combining this analytical
prediction with a regression of the predicted values of UEF to the
measured UEF.
DOE seeks comments on the use of analytical methods to convert
existing metrics to the ones described in the July 2014 test procedure
final rule. This is identified as issue 2 in section V.E, ``Issues on
Which DOE Seeks Comment.''
3. Empirical Regression
An alternative to the analytical approaches described in section
III.C.2 is to develop empirical equations from measured metrics under
the uniform efficiency descriptor test procedure to those obtained
using the existing consumer and commercial water heater test
procedures. This approach has the benefit of capturing the effects of
factors that are not addressed in analytical models. The drawbacks of
this approach are that it is susceptible to measurement errors and that
it may not be easily extended to water heaters that were not part of
the test program.
To derive the conversion factors from an empirical regression, DOE
first used a step regression method. The step regression method
produces a linear equation which uses a set of observed independent
variables, such as storage volume, input rate, delivery capacity,
recovery efficiency, energy factor, thermal efficiency, or standby
loss, and seeks to mathematically derive an equation using these
variables to relate to a set of observed dependent variables, such as
new delivery capacity (under the updated test method) and UEF. The step
regression method systematically recombines the set of independent
variables to produce an equation for each possible set. Each set's
equation is compared to the others and the equation with the best fit
is chosen. This approach eliminates factors that are not significant in
converting existing metrics to the new metrics. DOE also considered
simpler regression forms to reduce confusion in converting from old
metrics to new metrics and to ensure that the regressions were
applicable over the broad range of water heaters available on the
market. In these circumstances, DOE examined the deviations between
measured values and predicted values from the correction equations.
When those deviations were comparable, DOE opted for simplified models
that would be expected to capture the major phenomena that would affect
the new metrics. The regression tool found in the Analysis ToolPak of
Microsoft Excel (2010) was used to calculate the equation for each set
of independent variables.
As noted previously, because DOE has tentatively concluded that an
empirical regression methodology would be more accurate than the
analytical method described in section III.C.2 for determining first-
hour rating for storage water heaters, DOE has proposed conversion
factors for those metrics and product types based on the use of the
empirical regression methodology. DOE seeks comment on the use of the
regression method for the conversion factor analysis. This is
identified as issue 3 in section V.E, ``Issues on Which DOE Seeks
Comment.''
D. Testing Conducted for the Mathematical Conversion
1. Consumer Water Heater Testing
For its analysis of a mathematical conversion factor between the
existing efficiency metrics and the uniform efficiency descriptor, DOE
tested 43 consumer storage water heaters to both the existing and
updated test procedures. Table III.7 and Table III.8
[[Page 20129]]
below summarize the units that have been tested. Table III.7 summarizes
the units that have been tested according to heating type. Table III.8
provides an estimate of the distribution of those units across draw
pattern categories by using their first-hour ratings under the current
test (although it is acknowledged that the applied draw pattern for a
particular water heater could change under the new first-hour rating
test).
Table III.7--Consumer Storage Water Heater Test Distribution by Product
Type
------------------------------------------------------------------------
Number of
Product type units tested
------------------------------------------------------------------------
Gas-fired............................................... 22
Oil-fired............................................... 2
Electric................................................ 11
Heat Pump............................................... 6
Tabletop................................................ 2
------------------------------------------------------------------------
Table III.8--Consumer Storage Water Heater Test Distribution by Draw
Pattern
------------------------------------------------------------------------
Number of
Draw pattern * units tested
------------------------------------------------------------------------
Very Small **........................................... 0
Low..................................................... 3
Medium.................................................. 27
High.................................................... 13
------------------------------------------------------------------------
* The draw pattern shown is based on the current rated values; actual
draw patterns are dependent upon amended test procedure first-hour
rating discussed in section III.C.1.
** No very small consumer storage water heaters covered under the
existing test procedure were found on the market.
DOE also tested 22 consumer instantaneous water heaters to develop
the mathematical conversion for these products. Table III.9 below
summarizes the units that have been tested. Table III.10 provides an
estimate of the distribution of those units across draw patterns by
using their maximum GPM ratings under the current test (although it is
acknowledged that the applied draw pattern for a particular water
heater could change under the new maximum GPM test).
Table III.9--Consumer Instantaneous Water Heater Test Distribution by
Product Type
------------------------------------------------------------------------
Number of
Product type units tested
------------------------------------------------------------------------
Gas-fired *............................................. 17
Oil-fired **............................................ 0
Electric................................................ 5
------------------------------------------------------------------------
* Gas-fired water heaters include both natural gas and propane water
heaters, as well as water heaters capable of using either natural gas
or propane. DOE tested 10 natural gas water heaters, 1 propane water
heaters, and 6 water heaters capable of using either natural gas or
propane. Water heaters capable of using either fuel were tested with
natural gas.
** No oil-fired consumer instantaneous water heaters were found to be on
the market.
Table III.10--Consumer Instantaneous Water Heater Test Distribution by
Draw Pattern
------------------------------------------------------------------------
Number of
Draw pattern * units tested
------------------------------------------------------------------------
Very Small.............................................. 5
Low..................................................... 1
Medium.................................................. 7
High.................................................... 9
------------------------------------------------------------------------
* Draw pattern profiles are based on the rated values; actual draw
patterns are dependent upon tested value discussed in section III.C.1.
2. Residential-Duty Commercial Water Heater Testing
DOE tested 7 residential-duty commercial storage water heaters to
develop the mathematical conversion for this equipment. Table III.11
summarizes the units that have been tested. A table showing the
distribution of draw pattern within the residential-duty commercial
water heater test list is not available, because commercial water
heaters currently do not have first-hour ratings.
Table III.11--Residential-Duty Commercial Storage Water Heater Test
Distribution by Product Type
------------------------------------------------------------------------
Number of
Product type * units tested
------------------------------------------------------------------------
Gas-fired............................................... 7
Oil-fired **............................................ 0
------------------------------------------------------------------------
* Heat pump and tabletop water heaters were not found on the market and,
therefore, were not tested.
** One oil-fired unit failed during testing.
As discussed in section III.B.2, DOE did not analyze a mathematical
conversion for residential-duty commercial electric storage water
heaters or residential-duty commercial instantaneous water heaters.
E. Testing Results and Analysis of Test Data
1. Impact of Certain Water Heater Attributes on Efficiency Ratings
After conducting testing on all of the selected water heaters
according to both the existing test procedures and the uniform
efficiency descriptor test procedure, DOE examined how particular
attributes of water heaters might affect the conversion factors and
investigated the approaches discussed in section III.C for obtaining
conversion factors. The goal of this analysis was to determine whether
or not particular attributes necessitated separate conversion
equations. Separate conversions were created for subsets of the tested
units based on water heater attributes such as NOX emission
level, short or tall configuration, vent type, standing pilot or
electric ignition, if condensing or heat pump technology is used, and
if the unit is tabletop. Additionally, conversion equations were also
generated based on the full set of water heaters. To determine whether
it was necessary to develop separate conversion factors for a
particular attribute, the root-mean-square (RMS) of the difference
between the measured values and the values obtained through various
conversion methods was compared. The conversion approach with the
lowest cumulative RMS value for a particular fuel type was considered
to be the best candidate for the conversion equation.
The three levels of NOX emissions currently available in
water heaters on the market include standard (greater than or equal to
40 nanograms per joule (ng/J)), low (less than 40 ng/J and greater than
or equal to 10 ng/J for storage water heaters and greater than or equal
to 14 ng/J for instantaneous water heaters) and ultra-low (less than 10
ng/J for storage water heaters and less than 14 ng/J for instantaneous
water heaters).
Most units that are short or tall have been labeled as such by the
manufacturer; however, some units do not have this designation. DOE has
found that some units labeled as small are actually taller than units
labeled as tall. DOE is interested in how manufacturers determine
whether a unit is short or tall. This is identified as issue 4 in
section V.E, ``Issues on Which DOE Seeks Comment.''
The four venting configurations currently available in water
heaters on the market include atmospheric, direct, power, and power-
direct. Atmospheric and power vent units intake air from the area
surrounding the water heater, while direct and power-direct vents
intake air from outdoors. Atmospheric and direct
[[Page 20130]]
vent units use natural convection to circulate combustion air, while
power and power-direct vents use some additional method to force
circulation of combustion air. Concentric inlet and outlet piping is a
unique configuration that can be used in directly venting water heaters
to preheat incoming air using exhaust gas. For these tests, concentric
inlet and outlet piping was not used; inlet air for the direct and
power-direct vent units was delivered to the water heater in separate
pipes from that used for exhaust. As these tests were conducted under
identical controlled conditions, DOE determined that there is very
little difference between atmospheric and direct vent water heaters and
also between power and power-direct vent. For these reasons DOE has
grouped atmospheric and direct into the atmospheric configuration and
power and power-direct into the power configuration.
As an example of the process that was taken to examine the effect
of these factors, Table III.12 shows the cumulative RMS values for the
first-hour rating conversions for consumer storage water heaters. The
rows in the table indicate how the conversion equations were separated
out, and the columns provide the RMS for each class of consumer storage
water heaters. For gas water heaters, these values show that the
conversion approach that differentiates between condensing or non-
condensing technology and between NOX levels appears to
provide the best approach considering its low RMS values. No other
factors (e.g., short vs. tall, vent type, pilot type) were shown to
have any significance on the effectiveness of the conversion factor.
For oil-fired water heaters and electric water heaters, the lowest RMS
deviations occurred when all units of that fuel type were considered,
indicating that separating the conversion equations by tank shape was
not necessary. The findings presented here for first-hour rating
conversions are consistent with those for UEF. From these results, DOE
proposes to develop conversion equations for consumer storage water
heaters based on fuel type, with the gas units being further
differentiated by whether or not they are condensing units and by their
NOx emissions level ratings.
For consumer instantaneous water heaters and residential-duty
commercial water heaters, DOE found no dependence on factors such as
condensing operation or vent type. Conversion factors for these classes
of water heaters are, thus, based simply on fuel type.
Table III.12--First-Hour Rating RMS Values by Water Heater Attribute for Consumer Water Heaters
----------------------------------------------------------------------------------------------------------------
Gas-fired Oil-fired Electric
----------------------------------------------------------------------------------------------------------------
All Units (All fuel types)............. 6.99 6.89....................... 4.47.
All Units Short or Tall................ 6.87 5.79....................... 3.67.
Fuel Type (Gas, Oil or Electric)....... 7.16 Not enough units........... 3.88.
Fuel Type Short or Tall................ 6.91 No short units............. Not enough short units.
Fossil Fuel (Gas and Oil).............. 6.59 5.73....................... N/A.
Fossil Fuel Short or Tall.............. 6.52 5.82....................... N/A.
Condensing or Non-Condensing........... 6.66 N/A........................ N/A.
NOX Type (Standard, Low or Ultra Low).. 4.61 N/A........................ N/A.
Vent Type (Atmospheric or Power)....... 5.53 N/A........................ N/A.
Standing Pilot or Electric Ignition.... 5.53 N/A........................ N/A.
Non-Condensing NOX Type and Separate 3.98 N/A........................ N/A.
Condensing.
All Electric Types Separate............ N/A N/A........................ 3.43.
Heat Pump Separate..................... N/A N/A........................ 3.59.
----------------------------------------------------------------------------------------------------------------
2. Conversion Factor Derivation
DOE used the methods described in section III.C to derive the
mathematical conversion factor for the different types of water heaters
covered within the scope of this rulemaking (as discussed in section
III.B). This section describes the methodology that was applied to
develop a conversion factor for each type of water heater.
a. Consumer Storage Water Heaters
i. Test Results
As stated in section III.D.1, DOE has conducted testing of 43
consumer storage water heaters using both the current and new test
procedures. Table III.13 below presents the test data used to derive
the consumer storage water heater conversion factors. Table III.14
shows the water heater attributes by unit described in section III.D.1.
Table III.13--Consumer Storage Water Heater Test Data
--------------------------------------------------------------------------------------------------------------------------------------------------------
Current
Storage Input rate Current FHR Updated FHR recovery
Unit No. Type volume (Btu/h) (gal) (gal) efficiency EF UEF
(gal) (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
CS-1................................. Heat Pump............. 45.2 13,600 59.1 48.2 264.7 2.260 2.069
CS-2................................. Heat Pump............. 45.5 8,500 57.3 57.0 269.0 2.272 2.575
CS-3................................. Heat Pump............. 58.9 6,800 71.5 68.6 290.1 2.406 2.493
CS-4................................. Heat Pump............. 77.6 6,800 90.5 87.1 285.0 2.315 2.641
CS-5................................. Heat Pump............. 80.8 1,800 57.0 58.0 288.0 2.330 2.540
CS-6................................. Electric.............. 36.2 15,400 54.0 49.7 98.0 0.941 0.905
CS-7................................. Electric.............. 44.9 14,300 64.1 64.3 98.0 0.855 0.840
CS-8................................. Electric.............. 46.1 14,000 64.8 61.7 98.0 0.901 0.919
CS-9................................. Electric.............. 27.4 13,000 38.7 43.1 98.0 0.912 0.906
CS-10................................ Electric.............. 34.1 14,000 50.7 52.0 98.0 0.902 0.907
CS-11................................ Electric.............. 35.9 15,400 52.4 51.8 98.0 0.931 0.920
[[Page 20131]]
CS-12................................ Electric.............. 36.1 15,400 53.2 54.8 98.0 0.912 0.927
CS-13................................ Electric.............. 44.9 15,400 64.9 59.4 98.0 0.960 0.926
CS-14................................ Electric.............. 45.8 15,400 62.7 64.2 98.0 0.922 0.936
CS-15................................ Electric.............. 49.7 18,800 68.5 73.2 98.0 0.924 0.940
CS-16................................ Electric.............. 72.2 14,700 88.7 80.9 98.0 0.848 0.883
CS-17................................ Tabletop.............. 25.7 15,400 37.5 45.3 98.0 0.905 0.857
CS-18................................ Tabletop.............. 35.1 15,400 52.9 47.8 98.0 0.878 0.804
CS-19................................ Gas................... 38.4 39,800 67.0 81.1 80.5 0.601 0.630
CS-20................................ Gas................... 49.5 44,100 97.4 86.6 80.5 0.610 0.634
CS-21................................ Gas................... 37.8 39,700 70.1 86.9 83.8 0.608 0.641
CS-22................................ Gas................... 47.6 49,900 90.2 81.0 81.1 0.674 0.675
CS-23................................ Gas................... 37.9 39,400 74.4 81.6 80.3 0.691 0.705
CS-24................................ Gas................... 38.0 32,600 66.9 58.5 69.0 0.574 0.566
CS-25................................ Gas................... 38.0 39,800 80.2 63.8 83.6 0.711 0.669
CS-26................................ Gas................... 38.1 40,800 73.5 75.2 83.6 0.702 0.716
CS-27................................ Gas................... 38.2 39,300 71.9 77.6 77.4 0.607 0.635
CS-28................................ Gas................... 27.9 31,600 58.8 64.4 80.7 0.620 0.606
CS-29................................ Gas................... 38.1 40,200 74.7 70.6 80.5 0.622 0.569
CS-30................................ Gas................... 38.3 37,900 71.9 64.6 78.5 0.616 0.434
CS-31................................ Gas................... 47.3 50,600 95.1 87.0 78.8 0.606 0.640
CS-32................................ Gas................... 38.6 40,100 70.2 67.2 80.4 0.673 0.647
CS-33................................ Gas................... 38.9 32,400 68.6 65.2 78.1 0.666 0.624
CS-34................................ Gas................... 27.9 59,000 96.9 94.5 78.2 0.702 0.709
CS-35................................ Gas................... 38.5 36,000 66.0 68.0 85.0 0.699 0.670
CS-36................................ Gas................... 47.8 64,600 107.9 108.8 79.5 0.649 0.672
CS-37................................ Gas................... 45.7 39,800 91.0 84.8 96.3 0.830 0.828
CS-38................................ Gas................... 38.2 40,300 68.2 64.8 79.7 0.606 0.595
CS-39................................ Gas................... 38.2 38,300 71.3 64.6 75.2 0.625 0.596
CS-40................................ Gas................... 47.8 40,500 94.2 83.8 74.0 0.550 0.641
CS-41................................ Gas................... 48.1 36,000 92.4 88.2 81.4 0.631 0.662
CS-42................................ Oil................... 29.8 105,300 104.8 111.7 71.4 0.518 0.478
CS-43................................ Oil................... 30.1 105,300 112.5 127.4 89.4 0.605 0.641
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table III.14--Consumer Storage Water Heater Attributes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Standing pilot or
Unit No. NOX emission level Condensing Vent type Short or tall electric ignition
--------------------------------------------------------------------------------------------------------------------------------------------------------
CS-1........................... N/A.................... N/A................... N/A................... N/A................... N/A.
CS-2........................... N/A.................... N/A................... N/A................... N/A................... N/A.
CS-3........................... N/A.................... N/A................... N/A................... N/A................... N/A.
CS-4........................... N/A.................... N/A................... N/A................... N/A................... N/A.
CS-5........................... N/A.................... N/A................... N/A................... N/A................... N/A.
CS-6........................... N/A.................... N/A................... N/A................... Short................. N/A.
CS-7........................... N/A.................... N/A................... N/A................... Short................. N/A.
CS-8........................... N/A.................... N/A................... N/A................... Short................. N/A.
CS-9........................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-10.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-11.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-12.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-13.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-14.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-15.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-16.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-17.......................... N/A.................... N/A................... N/A................... N/A................... N/A.
CS-18.......................... N/A.................... N/A................... N/A................... N/A................... N/A.
CS-19.......................... Standard............... No.................... Atmospheric........... Short................. Yes.
CS-20.......................... Standard............... No.................... Atmospheric........... Short................. Yes.
CS-21.......................... Standard............... No.................... Atmospheric........... Tall.................. Yes.
CS-22.......................... Standard............... No.................... Power................. Tall.................. No.
CS-23.......................... Low.................... No.................... Atmospheric........... Short................. No.
CS-24.......................... Low.................... No.................... Atmospheric........... Short................. Yes.
CS-25.......................... Low.................... No.................... Atmospheric........... Tall.................. No.
CS-26.......................... Low.................... No.................... Atmospheric........... Tall.................. No.
CS-27.......................... Low.................... No.................... Atmospheric........... Tall.................. No.
CS-28.......................... Low.................... No.................... Atmospheric........... Tall.................. Yes.
CS-29.......................... Low.................... No.................... Atmospheric........... Tall.................. Yes.
CS-30.......................... Low.................... No.................... Atmospheric........... Tall.................. Yes.
[[Page 20132]]
CS-31.......................... Low.................... No.................... Atmospheric........... Tall.................. Yes.
CS-32.......................... Low.................... No.................... Power................. Short................. No.
CS-33.......................... Low.................... No.................... Power................. Short................. No.
CS-34.......................... Low.................... No.................... Power................. Tall.................. No.
CS-35.......................... Low.................... No.................... Power................. Tall.................. No.
CS-36.......................... Low.................... No.................... Power................. Tall.................. No.
CS-37.......................... Low.................... Yes................... Power................. Tall.................. No.
CS-38.......................... Ultra-Low.............. No.................... Atmospheric........... Short................. Yes.
CS-39.......................... Ultra-Low.............. No.................... Atmospheric........... Short................. Yes.
CS-40.......................... Ultra-Low.............. No.................... Atmospheric........... Tall.................. Yes.
CS-41.......................... Ultra-Low.............. No.................... Atmospheric........... Tall.................. Yes.
CS-42.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
CS-43.......................... N/A.................... N/A................... N/A................... Tall.................. N/A.
--------------------------------------------------------------------------------------------------------------------------------------------------------
ii. Conversion Factor Results
For consumer storage water heaters, DOE proposes to use the
regression method described in section III.C.3 to develop new first
hour ratings. Of the factors considered, DOE found that the existing
first hour rating was the best overall predictor of the new first hour
rating. These findings were based on the root mean squared errors
between predictions and measured values. In some cases, addition of
other factors in the regressions (e.g., input rate, storage volume) led
to predictions with slightly better RMS values, but DOE chose to be
consistent in its formulations by using the same factor, existing first
hour ratings. In these cases, DOE found that addition of extra terms
improved the RMS value by less than 1 gallon, so it tentatively
concluded that the added potential for confusion is not warranted. The
resulting equations for determining the FHRnew of consumer
storage water heaters are:
New FHRGas,Non-Condensing,Standard NOx = 1.0085 * FHREx
New FHRGas,Non-Condensing,Low NOx = 4.6894 + 0.9112 * FHREx
New FHRGas,Non-Condensing,Ultra Low NOx = 2.9267 + 0.8882 * FHREx
New FHRGas,Condensing = -0.7072 + 0.9724 * FHREx
New FHROil = 1.1018 * FHREx
New FHRElectric,Conventional&Tabletop = 11.9239 + 0.7879 * FHREx
New FHRElectric,Heat Pump = -2.3440 + 0.9856 * FHREx
where FHRnew is the new first hour rating, FHRex
is the existing first hour rating, and the slope and intercept are
constants obtained from a linear regression. While most of the data
allowed for such a regression fit, in two cases (oil, non-condensing
gas with standard level NOX burners) the available data were
too limited to produce reliable regressions. In these cases, the
intercepts of the regressions were assigned a value of zero, meaning
that a water heater with an FHRex of zero would also have an
FHRnew of zero.
The next step in the conversion is to determine which draw pattern
is to be applied to convert from EF to UEF. After the first-hour rating
under the uniform efficiency descriptor is determined through the
conversion factor above, the value can be applied to determine the
appropriate draw pattern bin (i.e., very small, low, medium, or high)
using Table III.3 of this NOPR or Table 1 of the uniform efficiency
descriptor test procedure. 79 FR 40542, 40572 (July 11, 2014). With the
draw bin known, the UEF value based on the WHAM analytical model can be
calculated using the process described in section III.C.2.c.i for all
types except for heat pump water heaters. Alternatively, DOE
investigated the step regression approach described in section III.C.3
to convert EF to UEF. DOE found that a third technique, a combination
of these approaches in which the results of the WHAM analytical model
are used as the independent variable in a standard linear regression
analysis, produced the best results. Separate conversion equations were
developed for the same categories as used for first-hour rating. The
results of the first-hour regression, the WHAM analytical model, the
step regression model, and the combined WHAM-regression model are
presented below in Table III.16. The RMS errors for the classes range
from 0.0014 to 0.0495 when using a combined WHAM-regression model. For
heat pump water heaters, a linear regression in which the UEF is
estimated solely from the existing EF results in an RMS error of 0.187.
Considering the larger magnitude of UEFs for heat pump water heaters,
DOE has tentatively concluded that this relatively high RMS error is
acceptable for heat pump water heaters. DOE has, therefore, tentatively
decided to use the combined WHAM-regression approach to calculate the
consumer storage water heater conversion factor for non-heat pump water
heaters and to apply a regression that relates UEF to EF for heat pump
water heaters. The WHAM-regression approach accounts for the test
procedure changes in terms of daily volume delivered and storage tank
temperature, and it corrects for the unaccounted changes using a
regression with actual test data. Because the data are not believed to
be publicly available to compute the WHAM estimate for heat pump water
heaters, DOE proposes to base this conversion on an empirical
regression. The resulting equations for determining the UEF of consumer
storage water heaters are:
[GRAPHIC] [TIFF OMITTED] TP14AP15.015
UEFGas,Non-Condensing,Standard NOx = 0.2726 * UEFWHAM + 0.4736
UEFGas,Non-Condensing,Low NOx = 0.9966 * UEFWHAM - 0.0126
UEFGas,Non-Condensing,Ultra-Low NOx = 0.5811 *UEFWHAM + 0.2673
[[Page 20133]]
UEFGas,Condensing = 0.9164 * UEFWHAM + 0.0409
UEFOil = 1.1185 * UEFWHAM - 0.0945
UEFElectric,Conventional&Tabletop = 0.8673 * UEFWHAM + 0.1227
UEFElectric,Heat Pump = 1.5485 * EF - 1.1235
where UEFWHAM is the conversion factor calculated using the
WHAM analytical model and the coefficient values shown in Table III.15,
P is the nameplate input rate in Btu/h, and [eta]r is the
recovery efficiency expressed in decimal form (e.g., 0.98 instead of 98
[%]).
Table III.15--Coefficients for WHAM-Based UEF Conversion Factor
----------------------------------------------------------------------------------------------------------------
Draw bin a b c d
----------------------------------------------------------------------------------------------------------------
Very Small...................................... 56095146 12884892499 8930623 15125743368
Low............................................. 56095146 48962591496 33936368 57477824799
Medium.......................................... 56095146 70866908744 49118427 83191588525
High............................................ 56095146 108233096990 75017235 127056244293
----------------------------------------------------------------------------------------------------------------
Table III.16--Consumer Storage Water Heater Conversion Factor Results
----------------------------------------------------------------------------------------------------------------
WHAM-
Unit No. Tested FHR Regression Tested UEF WHAM UEF Regression Regression
(gal) FHR (gal) UEF UEF
----------------------------------------------------------------------------------------------------------------
CS-1........................ 48.2 55.9 2.069 2.209 2.375 2.384
CS-2........................ 57.0 54.1 2.575 2.215 2.395 2.391
CS-3........................ 68.6 68.1 2.493 2.339 2.603 2.525
CS-4........................ 87.1 86.9 2.641 2.435 2.461 2.630
CS-5........................ 58.0 53.8 2.540 2.213 2.484 2.388
CS-6........................ 49.7 54.4 0.905 0.935 0.930 0.933
CS-7........................ 64.3 62.4 0.840 0.836 0.875 0.847
CS-8........................ 61.7 62.9 0.919 0.888 0.904 0.893
CS-9........................ 43.1 42.4 0.906 0.866 0.911 0.874
CS-10....................... 52.0 51.8 0.907 0.888 0.905 0.893
CS-11....................... 51.8 53.2 0.920 0.923 0.923 0.923
CS-12....................... 54.8 53.9 0.927 0.901 0.911 0.904
CS-13....................... 59.4 63.0 0.926 0.956 0.941 0.952
CS-14....................... 64.2 61.4 0.936 0.912 0.917 0.914
CS-15....................... 73.2 65.9 0.940 0.915 0.919 0.916
CS-16....................... 80.9 81.8 0.883 0.880 0.871 0.885
CS-17....................... 45.3 41.5 0.857 0.855 0.896 0.864
CS-18....................... 47.8 53.6 0.804 0.862 0.873 0.870
CS-19....................... 81.1 67.5 0.630 0.578 0.632 0.631
CS-20....................... 86.6 98.3 0.634 0.651 0.637 0.651
CS-21....................... 86.9 70.7 0.641 0.583 0.636 0.632
CS-22....................... 81.0 91.0 0.675 0.705 0.675 0.666
CS-23....................... 81.6 72.5 0.705 0.676 0.683 0.661
CS-24....................... 58.5 65.6 0.566 0.558 0.571 0.544
CS-25....................... 63.8 77.8 0.669 0.739 0.702 0.724
CS-26....................... 75.2 71.6 0.716 0.685 0.694 0.670
CS-27....................... 77.6 70.2 0.635 0.587 0.603 0.572
CS-28....................... 64.4 58.3 0.606 0.598 0.616 0.583
CS-29....................... 70.6 72.8 0.569 0.600 0.617 0.585
CS-30....................... 64.6 70.2 0.434 0.595 0.611 0.580
CS-31....................... 87.0 91.4 0.640 0.645 0.602 0.630
CS-32....................... 67.2 68.6 0.647 0.656 0.666 0.641
CS-33....................... 65.2 67.2 0.624 0.651 0.660 0.636
CS-34....................... 94.5 93.0 0.709 0.721 0.694 0.706
CS-35....................... 68.0 64.8 0.670 0.679 0.690 0.664
CS-36....................... 108.8 103.0 0.672 0.681 0.643 0.666
CS-37....................... 84.8 87.8 0.828 0.861 0.824 0.830
CS-38....................... 64.8 63.5 0.595 0.583 0.592 0.606
CS-39....................... 64.6 66.3 0.596 0.609 0.599 0.621
CS-40....................... 83.8 86.6 0.641 0.589 0.653 0.610
CS-41....................... 88.2 85.0 0.662 0.670 0.649 0.656
CS-42....................... 111.7 115.5 0.478 0.557 0.537 0.529
CS-43....................... 127.4 123.9 0.641 0.659 0.613 0.643
----------------------------------------------------------------------------------------------------------------
b. Consumer Instantaneous
i. Test Results
As stated in section III.D.1, DOE has tested 22 consumer
instantaneous water heaters to both the current and new test
procedures. Table III.17 presents the test data used to derive the
consumer instantaneous water heater conversion factors. It is noted
that test results show measured recovery efficiencies above 100 percent
and EFs and UEFs above 1 for electric instantaneous units; DOE
acknowledges that these results appear to violate theoretical limits
and believes that these results are an artifact of measurement
uncertainty. Table III.18 shows the water heater attributes by unit
described in section III.D.1.
[[Page 20134]]
Table III.17--Consumer Instantaneous Water Heater Test Data
--------------------------------------------------------------------------------------------------------------------------------------------------------
Current
Unit No. Type Input rate Current max Updated max recovery EF UEF
(Btu/h) GPM GPM efficiency (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
CI-1.............................. Electric............ 8,200 0.20 0.23 101.2 1.012 0.982
CI-2.............................. Electric............ 32,400 0.82 0.93 101.5 1.017 0.981
CI-3.............................. Electric............ 34,100 0.87 0.99 101.8 1.018 1.001
CI-4.............................. Electric............ 27,300 0.68 0.80 102.0 1.019 1.004
CI-5.............................. Electric............ 20,500 0.52 0.59 102.3 1.021 1.005
CI-6.............................. Gas................. 179,900 4.01 4.58 82.4 0.821 0.832
CI-7.............................. Gas................. 178,500 4.08 4.71 83.8 0.837 0.828
CI-8.............................. Gas................. 120,900 2.69 3.07 84.1 0.839 0.814
CI-9.............................. Gas................. 199,000 4.61 4.86 87.0 0.876 0.841
CI-10............................. Gas................. 151,900 3.47 3.96 88.3 0.891 0.815
CI-11............................. Gas................. 141,100 3.11 3.61 81.4 0.810 0.824
CI-12............................. Gas................. 190,400 4.23 4.81 83.4 0.829 0.818
CI-13............................. Gas................. 142,500 2.96 3.43 80.9 0.801 0.795
CI-14............................. Gas................. 197,200 5.19 5.80 96.7 0.966 0.958
CI-15............................. Gas................. 199,800 4.80 4.10 93.8 0.932 0.931
CI-16............................. Gas................. 151,500 3.24 3.88 84.3 0.837 0.805
CI-17............................. Gas................. 180,400 3.92 4.60 85.0 0.853 0.827
CI-18............................. Gas................. 175,800 3.67 4.30 84.5 0.838 0.830
CI-19............................. Gas................. 199,200 4.30 5.07 75.0 0.743 0.799
CI-20............................. Gas................. 154,100 3.98 4.47 91.6 0.913 0.922
CI-21............................. Gas................. 201,300 4.90 5.70 88.0 0.851 0.884
CI-22............................. Gas................. 199,900 5.12 4.91 89.9 0.888 0.943
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table III.18--Consumer Instantaneous Water Heater Attributes
----------------------------------------------------------------------------------------------------------------
Unit No. NOX emission level Condensing Vent type
----------------------------------------------------------------------------------------------------------------
CI-1............................... N/A................... N/A................... N/A.
CI-2............................... N/A................... N/A................... N/A.
CI-3............................... N/A................... N/A................... N/A.
CI-4............................... N/A................... N/A................... N/A.
CI-5............................... N/A................... N/A................... N/A.
CI-6............................... Low................... No.................... Atmospheric.
CI-7............................... Low................... No.................... Atmospheric.
CI-8............................... Low................... No.................... Atmospheric.
CI-9............................... Low................... No.................... Atmospheric.
CI-10.............................. Low................... No.................... Atmospheric.
CI-11.............................. Low................... No.................... Power.
CI-12.............................. Low................... No.................... Power.
CI-13.............................. Low................... No.................... Power.
CI-14.............................. Low................... Yes................... Atmospheric.
CI-15.............................. Low................... Yes................... Atmospheric.
CI-16.............................. Ultra-Low............. No.................... Atmospheric.
CI-17.............................. Ultra-Low............. No.................... Atmospheric.
CI-18.............................. Ultra-Low............. No.................... Atmospheric.
CI-19.............................. Ultra-Low............. No.................... Atmospheric.
CI-20.............................. Ultra-Low............. Yes................... Atmospheric.
CI-21.............................. Ultra-Low............. Yes................... Atmospheric.
CI-22.............................. Ultra-Low............. Yes................... Power.
----------------------------------------------------------------------------------------------------------------
ii. Conversion Factor Results
As stated in section III.C.2, DOE developed an analytical model to
convert the existing maximum GPM rating for consumer instantaneous
water heaters to ratings under the uniform efficiency descriptor test
procedure. DOE also attempted to develop an analytical method based on
the WHAM equation to estimate the change in existing energy factor
ratings under the existing consumer water heater test procedure to
values under the uniform efficiency descriptor test procedure. Along
with this analytical model, step regression and combined analytical
model-regression approaches were conducted. The results of the
analytical model, step regression, and combined analytical model-
regression approaches for the maximum GPM and UEF conversions are
presented in Table III.20. For the maximum GPM conversions, the RMS
errors for the three approaches are 0.38, 0.35, and 0.38, respectively.
For the UEF conversions, the three approaches have RMS errors of 0.024,
0.028, and 0.023, respectively. DOE has tentatively decided to use the
analytical model approach to calculate the consumer instantaneous
maximum GPM conversion factor owing to the fact that the model predicts
the resultant data very closely and that it will broadly apply to those
units not tested. DOE has also tentatively decided to use the combined
analytical model-regression approach to convert from EF to UEF since
the RMS errors are low, and it has tentatively concluded that the use
of the model and regression will capture key
[[Page 20135]]
effects that may not be captured with either approach by itself. For
the electric instantaneous water heaters, DOE imposed a zero intercept
on the regression since the regression with an intercept resulted in
UEFs above the theoretical limit of 1. DOE has tentatively concluded
that this step is technically acceptable, as it effectively states that
a water heater with an EF of zero should also have a UEF of zero. The
resulting conversion factors for both first hour rating and UEF are:
MaxGPMnew = 1.147 * MaxGPMEx
UEFgas = 0.9059 * UEFmodel + 0.0783
UEFelectric = 1.0079 * UEFmodel
where MaxGPMEx is the maximum GPM rating based on the
current DOE test procedure and UEFmodel is the predicted UEF
determined using the following analytical model:
[GRAPHIC] [TIFF OMITTED] TP14AP15.016
Values for the coefficients A and B are dependent upon the draw pattern
applied during the simulated-use test and are provided in Table III.19.
Table III.19--Coefficients To Determine UEFmodel for Consumer
Instantaneous Water Heaters
------------------------------------------------------------------------
Draw bin A B
------------------------------------------------------------------------
Very Small........................................ 5514.2 170.2
Low............................................... 20954 262.4
Medium............................................ 30328 290.9
High.............................................. 46319 294.0
------------------------------------------------------------------------
Table III.20--Consumer Instantaneous Water Heater Conversion Factor Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Combined
Tested max Analytical Regression analytical- Analytical Regression Analytical-
Unit No. GPM max GPM max GPM regression Tested UEF UEF UEF regression
max GPM UEF
--------------------------------------------------------------------------------------------------------------------------------------------------------
CI-1.................................... 0.23 0.23 0.24 0.23 0.982 0.982 0.980 0.989
CI-2.................................... 0.93 0.94 0.94 0.94 0.981 0.984 0.987 0.992
CI-3.................................... 0.99 1.00 1.00 1.00 1.001 0.987 0.995 0.995
CI-4.................................... 0.80 0.78 0.78 0.78 1.004 0.989 1.001 0.997
CI-5.................................... 0.59 0.59 0.60 0.59 1.005 0.991 1.008 0.999
CI-6.................................... 4.58 4.60 4.58 4.60 0.832 0.820 0.816 0.820
CI-7.................................... 4.71 4.68 4.66 4.68 0.828 0.834 0.829 0.833
CI-8.................................... 3.07 3.08 3.17 3.08 0.814 0.834 0.830 0.834
CI-9.................................... 4.86 5.28 5.22 5.28 0.841 0.865 0.859 0.861
CI-10................................... 3.96 3.98 4.01 3.98 0.815 0.878 0.871 0.873
CI-11................................... 3.61 3.56 3.62 3.56 0.824 0.808 0.807 0.810
CI-12................................... 4.81 4.85 4.82 4.85 0.818 0.829 0.822 0.829
CI-13................................... 3.43 3.39 3.46 3.39 0.795 0.803 0.800 0.805
CI-14................................... 5.80 5.95 5.84 5.95 0.958 0.961 0.931 0.948
CI-15................................... 4.10 5.50 5.43 5.50 0.931 0.933 0.904 0.923
CI-16................................... 3.88 3.71 3.76 3.71 0.805 0.836 0.829 0.835
CI-17................................... 4.60 4.49 4.49 4.49 0.827 0.845 0.841 0.844
CI-18................................... 4.30 4.21 4.22 4.21 0.830 0.840 0.829 0.839
CI-19................................... 5.07 4.93 4.90 4.93 0.799 0.746 0.754 0.754
CI-20................................... 4.47 4.56 4.55 4.56 0.922 0.911 0.889 0.903
CI-21................................... 5.70 5.62 5.54 5.62 0.884 0.875 0.840 0.870
CI-22................................... 4.91 5.87 5.77 5.87 0.943 0.894 0.869 0.887
--------------------------------------------------------------------------------------------------------------------------------------------------------
c. Residential-Duty Commercial Storage Testing
i. Test Data
As stated in section III.D.2, DOE has tested 7 residential-duty
commercial storage water heaters to both the current and new test
procedures. Table III.21 below presents the test data used to derive
the residential-duty commercial storage water heater conversion
factors. Table III.22 shows the water heater attributes by unit
described in section III.D.2.
Table III.21--Residential-Duty Commercial Storage Water Heater Test Data
--------------------------------------------------------------------------------------------------------------------------------------------------------
Storage Input rate Tested thermal Tested standby Updated FHR
Unit No. Type volume (gal) (Btu/h) efficiency (%) loss (Btu/h) (gal) UEF
--------------------------------------------------------------------------------------------------------------------------------------------------------
RD-1............................. Gas.................. 95.4 79,100 80.4 1,178.2 109.8 0.514
RD-2............................. Gas.................. 72.7 67,400 67.9 721.0 90.3 0.585
RD-3............................. Gas.................. 71.3 69,700 75.5 839.4 119.3 0.619
RD-4............................. Gas.................. 48.3 76,500 93.6 328.0 137.0 0.816
RD-5............................. Gas.................. 48.4 75,300 88.9 338.1 126.5 0.725
RD-6............................. Gas.................. 47.8 75,700 90.0 358.4 103.3 0.621
RD-7............................. Gas.................. 71.0 63,800 67.1 1,546.8 111.5 0.470
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 20136]]
Table III.22--Residential-Duty Commercial Storage Water Heater Attributes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Standing pilot or
Unit No. NOX emission level Condensing Vent type Short or tall electric ignition
--------------------------------------------------------------------------------------------------------------------------------------------------------
RD-1........................... Standard............... No.................... Atmospheric........... Tall.................. Yes.
RD-2........................... Standard............... No.................... Power................. Tall.................. No.
RD-3........................... Standard............... No.................... Power................. Tall.................. No.
RD-4........................... Low.................... Yes................... Atmospheric........... Short................. No.
RD-5........................... Low.................... Yes................... Power................. Tall.................. No.
RD-6........................... Low.................... Yes................... Power................. Tall.................. No.
RD-7........................... Ultra-Low.............. No.................... Atmospheric........... Tall.................. Yes.
--------------------------------------------------------------------------------------------------------------------------------------------------------
ii. Conversion Factor Results
As stated in section III.C.2.b, DOE is not aware of an analytical
model to convert the thermal efficiency and standby loss ratings under
the current test procedure to first-hour rating values under the new
test procedure. Therefore, the step regression method described in
section III.C.3 along with the best combination of water heater
attributes were used to determine the following first-hour rating
conversion factors:
New FHRFossil Fuel = 1.0226 * Q + 39.81
Where Q is the input rate of the burner in kBtu/h. For this regression,
DOE decided to group both oil and gas water heaters because of the lack
of oil water heaters identified. DOE has tentatively concluded that
this grouping is the best approach to convert ratings for any
residential-duty oil water heater on the market.
The next step in the conversion is to determine which draw pattern
is to be applied to convert to UEF. After the first-hour rating under
the uniform efficiency descriptor is determined through the conversion
factor above, the value can be applied to determine the appropriate
draw pattern bin (i.e., very small, low, medium, or high) using Table
III.3 of this NOPR or Table 1 of the uniform efficiency descriptor test
procedure. 79 FR 40542, 40572 (July 11, 2014). With the draw bin known,
the UEF value based on the analytical model can be calculated using the
process described in section III.C.2.c.iii. The analytical results,
along with the results of the step regression and analytical-regression
are shown in Table III.23 and have RMS values of 0.074, 0.055, and
0.053, respectively. Based on these results, DOE has tentatively
decided to use the combined analytical-regression approach to calculate
the residential-duty commercial storage water heater conversion factor.
While the regression approach yields a slightly better RMS error, DOE
has tentatively concluded that the use of the analytical model will
make the conversion more robust over the entire family of residential-
duty commercial storage water heaters since it captures the effects of
water temperature, draw volume per day, thermal efficiency, and standby
loss that are expected to be valid for any water heater. Thus, the use
of an analytical model is expected to be less prone to error should a
model have some unexpected characteristic that was not captured in the
water heaters tested as part of this NOPR. The resulting equations for
determining the UEF of consumer storage water heaters are:
UEFfossil fuel = 0.7300 * UEFrd + 0.1413
Where UEFrd is the estimate of the UEF for residential-duty
water heaters computed with the following equation:
[GRAPHIC] [TIFF OMITTED] TP14AP15.017
where C1 is a constant dependent upon the draw pattern given
in Table III.6, Et is the thermal efficiency in fractional
form (i.e., 0.85 instead of 85 (%)), and SL is the standby loss in BTU/
h.
Table III.23--Residential-Duty Commercial Conversion Factor Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tested FHR Regression FHR Analytical-
Unit No. (gal) (gal) Tested UEF Analytical UEF Regression UEF regression UEF
--------------------------------------------------------------------------------------------------------------------------------------------------------
RD-1.............................................. 109.8 120.7 0.514 0.573 0.530 0.560
RD-2.............................................. 90.3 108.8 0.585 0.562 0.629 0.551
RD-3.............................................. 119.3 111.1 0.619 0.595 0.604 0.575
RD-4.............................................. 137.0 118.0 0.816 0.828 0.715 0.746
RD-5.............................................. 126.5 116.9 0.725 0.788 0.713 0.717
RD-6.............................................. 103.3 117.3 0.621 0.791 0.709 0.719
RD-7.............................................. 111.5 105.0 0.470 0.466 0.449 0.481
--------------------------------------------------------------------------------------------------------------------------------------------------------
d. Residential-Duty Instantaneous Testing
As discussed in section III.B.2, no instantaneous residential-duty
commercial water heaters exist on the market. Therefore, a conversion
factor is not needed.
3. Energy Conservation Standard Derivation
After developing the mathematical conversion factors to convert
from the existing efficiency ratings to the efficiency ratings under
the UEF metric, DOE sought to update its energy conservation standards
for covered water heater products so as to be in terms of UEF. DOE
investigated several possible methods to determine the appropriate
energy conservation standards in terms of UEF.
First, DOE considered the ``percent difference'' method, which is
the method DOE ultimately has proposed for updating the energy
conservation standards so as to be based on the UEF metric. The percent
difference method was conducted as follows:
1. Apply conversion factor to convert the current efficiency
metrics provided in the relevant consumer or commercial database to the
calculated UEF value for each water heater on the market.
2. Calculate the current efficiency standard for each water heater
in the database, as follows:
[[Page 20137]]
a. For consumer water heaters, find the minimum EF.
b. For residential-duty commercial water heaters, find the minimum
thermal efficiency.
3. Find the percent difference between the rated efficiency value
and the standard for each water heater in the database, as follows:
[GRAPHIC] [TIFF OMITTED] TP14AP15.018
4. Find the new energy conservation standard for each water heater
in the database, as follows:
a. UEFmin = UEF (1 - PD)
5. Find a line through their minimum UEF values.
The advantage of using a ``percent difference'' is that the updated
energy conservation standard is a function of the UEF conversion for
all water heaters rather than a subset. It also allows for conversions
of standards for classes or groupings of water heaters where no
minimally compliant models are currently available on the market. The
proposed standards in terms of uniform energy factor are shown below by
product class and draw pattern.
Table III.24--Updated Consumer Water Heater Energy Conservation Standards
----------------------------------------------------------------------------------------------------------------
Rated storage
Product class volume Draw pattern Uniform energy factor
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage............. >=20 gal and <=55 Very Small............... 0.3263 - (0.0019 x Vr)
gal.
Low...................... 0.5891 - (0.0019 x Vr)
Medium................... 0.6326 - (0.0013 x Vr)
High..................... 0.7128 - (0.0025 x Vr)
>55 gal and <=100 Very Small............... 0.5352 - (0.0007 x Vr)
gal.
Low...................... 0.7375 - (0.0009 x Vr)
Medium................... 0.7704 - (0.0010 x Vr)
High..................... 0.7980 - (0.0010 x Vr)
Oil-fired Storage............. <=50 gal......... Very Small............... 0.2267 - (0.0014 x Vr)
Low...................... 0.4867 - (0.0006 x Vr)
Medium................... 0.6016 - (0.0012 x Vr)
High..................... 0.6529 - (0.0005 x Vr)
Electric Storage.............. >=20 gal and <=55 Very Small............... 0.8268 - (0.0002 x Vr)
gal.
Low...................... 0.9393 - (0.0004 x Vr)
Medium................... 0.9683 - (0.0007 x Vr)
High..................... 0.9656 - (0.0004 x Vr)
>55 gal and <=120 Very Small............... 1.2701 - (0.0011 x Vr)
gal.
Low...................... 1.9137 - (0.0011 x Vr)
Medium................... 2.0326 - (0.0011 x Vr)
High..................... 2.1858 - (0.0011 x Vr)
Tabletop Storage.............. >=20 gal and Very Small............... 0.6808 - (0.0022 x Vr)
<=100 gal.
Low...................... 0.8770 - (0.0012 x Vr)
Medium................... 0.9063 - (0.0009 x Vr)
High..................... 0.9302 - (0.0006 x Vr)
Gas-fired Instantaneous....... <2 gal........... All...................... 0.8036 - (0.0019 x Vr)
Electric Instantaneous........ <2 gal........... All...................... 0.9192 - (0.0013 x Vr)
----------------------------------------------------------------------------------------------------------------
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as
specified by the manufacturer.
Table III.25--Updated Residential-Duty Commercial Water Heater Energy Conservation Standards
----------------------------------------------------------------------------------------------------------------
Product class Draw pattern Uniform energy factor
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage.................... Very Small..................... 0.3261 - (0.0006 x Vr)
Low............................ 0.5219 - (0.0008 x Vr)
Medium......................... 0.5585 - (0.0006 x Vr)
High........................... 0.6044 - (0.0005 x Vr)
Oil-fired Storage.................... Very Small..................... 0.3206 - (0.0006 x Vr)
Low............................ 0.5577 - (0.0019 x Vr)
Medium......................... 0.6027 - (0.0019 x Vr)
High........................... 0.6446 - (0.0018 x Vr)
----------------------------------------------------------------------------------------------------------------
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as
specified by the manufacturer.
As stated in section III.A, EEI commented in response to the
November 2013 NOPR, that the updated energy conservation standards
should be not more stringent than they are currently. The percent
difference from the current rated energy factors and energy
conservation standards are used to derive the new energy conservation
[[Page 20138]]
standards; therefore, the updated standards are no more stringent than
those currently in existence. A.O. Smith and AHRI suggested that the
average difference between the current and new ratings should not be
used to convert the energy conservation standards. At no point in the
conversion factor derivation or energy conservation standard analysis
is a simple average taken, but rather, the trends of all the
traditional factors affecting water heaters are considered.
DOE also investigated a second method of determining the energy
conservation standards where only test data from minimally-compliant
water heaters would be used to develop a conversion factor using the
analytical and regression methods described in section III.C. Then,
this set of conversion factors could be applied to the minimum energy
conservation standards to determine the appropriate energy conservation
standards in terms of the UEF metric. This method would remove from
consideration any factors that are present in more-efficient water
heaters, so the resulting change in the standard would not be skewed at
all by the inclusion of higher-efficiency products in the mathematical
conversion. However, the conversion factors developed through such a
methodology would potentially not be applicable for converting the
efficiency ratings of products above the baseline. Therefore, DOE chose
to pursue a methodology that was applicable to all water heaters and
perform the conversion of standards based on the ``percent difference''
method described above.
DOE seeks comment on the most appropriate method for determining
the energy conservation standards based on the updated test procedure.
This is identified as issue 5 in section V.E, ``Issues on Which DOE
Seeks Comment.''
F. Certification and Labeling Issues
Consumer water heaters and residential-duty commercial water
heaters manufactured prior to the effective date of the uniform energy
factor test procedure final rule (i.e., July 13, 2015) that comply with
the efficiency standards and labeling requirements in effect prior to
that final rule will be considered to comply with the converted UEF
standards and with any revised labeling requirements established by the
Federal Trade Commission (FTC) to carry out the final rule. (42 U.S.C.
6295(e)(5)(K)) The statute requires that the standard be in terms of
UEF as of July 13, 2015. Accordingly, DOE proposes to require
manufacturers to provide EF and UEF for consumer water heaters (or
thermal efficiency and standby loss and UEF for commercial residential-
duty water heaters) in certification reports filed between July 13,
2015, and the compliance date determined by the final rule in this
rulemaking. Manufacturers would not be required to submit revised
certification reports for previously certified basic models until the
next annual certification date (May 1).
Allowing manufacturers to submit both EF and UEF data would allow
manufacturers to fulfill the statutory requirement to begin using UEF
for purposes of compliance with standards but would also allow
manufacturers to provide the necessary information to determine costs
under the current FTC labeling requirements. This would also allow a
transition period for FTC to pursue a rulemaking to determine whether
changes are needed to the water heater EnergyGuide label due to changes
in the water heater test procedure. DOE expects that the conversion
factors proposed in this notice could be used to convert EF to UEF for
previously certified basic models or to convert UEF values
``backwards'' to EF to determine the appropriate costs for labeling of
new basic models until FTC has determined whether to make changes to
the label. DOE has proposed a methodology for calculating costs based
on UEF testing that could be used in future FTC labeling requirements.
DOE requests comment on whether DOE should adopt such a provision in
the final rule in this rulemaking or postpone adoption until FTC has
had an opportunity to evaluate the ENERGY GUIDE label.
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
The Office of Management and Budget (OMB) has determined that test
procedure rulemakings do not constitute ``significant regulatory
actions'' under section 3(f) of Executive Order 12866, Regulatory
Planning and Review, 58 FR 51735 (Oct. 4, 1993). Accordingly, this
action was not subject to review under the Executive Order by the
Office of Information and Regulatory Affairs (OIRA) in the Office of
Management and Budget.
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires
preparation of an initial regulatory flexibility analysis (IFRA) for
any rule that by law must be proposed for public comment, unless the
agency certifies that the rule, if promulgated, will not have a
significant economic impact on a substantial number of small entities.
As required by Executive Order 13272, ``Proper Consideration of Small
Entities in Agency Rulemaking,'' 67 FR 53461 (August 16, 2002), DOE
published procedures and policies on February 19, 2003, to ensure that
the potential impacts of its rules on small entities are properly
considered during the DOE rulemaking process. 68 FR 7990. DOE has made
its procedures and policies available on the Office of the General
Counsel's Web site: https://energy.gov/gc/office-general-counsel.
This proposed rule would prescribe a mathematical conversion that
would be used to determine compliance with energy conservation
standards for consumer water heaters and certain commercial water
heaters. For consumer water heaters and certain commercial water
heaters, the mathematical conversion would establish a bridge between
the rated values based on the results under the current test procedures
and the uniform efficiency descriptor of the new test procedure.
Furthermore, the conversion factor will ensure that no products which
currently pass energy conservation standards fail to meet the energy
conservation standards after the conversion factor has been applied.
DOE reviewed this proposed rule under the provisions of the Regulatory
Flexibility Act and the policies and procedures published on February
19, 2003. 68 FR 7990.
For the manufacturers of the covered water heater products, the
Small Business Administration (SBA) has set a size threshold, which
defines those entities classified as ``small businesses'' for the
purposes of the statute. DOE used the SBA's small business size
standards to determine whether any small entities would be subject to
the requirements of the rule. 65 FR 30836, 30849 (May 15, 2000), as
amended at 65 FR 53533, 53545 (Sept. 5, 2000) and at 77 FR 49991,
50008-11 (August 20, 2012) and codified at 13 CFR part 121. The size
standards are listed by North American Industry Classification System
(NAICS) code and industry description and are available at https://www.sba.gov/content/table-small-business-size-standards. Consumer water
heater manufacturing is classified under NAICS code 335228--``Other
Major Household Appliance Manufacturing.'' The SBA sets a threshold of
500 employees or less for an entity to be considered as a small
business. Commercial water heater manufacturing is classified under
NAICS code 333318--``Other
[[Page 20139]]
Commercial and Service Industry Machinery Manufacturing,'' for which
SBA sets a size threshold of 1,000 employees or fewer as being
considered a small business.
DOE has identified 19 manufacturers of consumer water heaters
(including manufacturers of products that fall under the expanded
scope) that can be considered small businesses. DOE identified seven
manufacturers of ``residential-duty'' commercial water heaters that can
be considered small businesses. Six of the ``residential-duty''
commercial water heater manufacturers also manufacture consumer water
heaters, so the total number of water heater manufacturers impacted by
this rule would be 20. DOE's research involved reviewing several
industry trade association membership directories (e.g., AHRI), product
databases (e.g., AHRI, CEC, and ENERGY STAR databases), individual
company Web sites, and marketing research tools (e.g., Hoovers reports)
to create a list of all domestic small business manufacturers of
products covered by this rulemaking.
For the reasons explained below, DOE has concluded that the test
procedure amendments contained in this proposed rule would not have a
significant economic impact on any manufacturer, including small
manufacturers.
For consumer water heaters that were covered under the old test
procedure and energy conservation standards, the conversion factor in
this proposed rule would convert the rated values based on the current
test procedure to equivalent values based on the new uniform descriptor
test procedure. Although the energy conservation standards for consumer
water heaters will be denominated using the uniform descriptor, the
statute provides that all units that are on the market as of July 13,
2015, that meet the April 16, 2015 energy factor standard will be
deemed to meet the converted standards.
For certain commercial water heaters, defined under the term
``residential-duty commercial water heater,'' the conversion factor in
this proposed rule would convert the rated values based on the current
test procedure to the uniform descriptor which is based on the new test
procedure. The energy conservation standards for commercial water
heating equipment will be denominated using the uniform descriptor. The
statute provides that all units that are on the market as of July 13,
2015, that meet the thermal efficiency and standby losses standards
will be deemed to meet the converted standards.
At the date that compliance is required with the new test
procedure, all water heating units with residential applications (i.e.,
consumer units and residential-duty commercial units) must meet the
applicable energy conservation standards. These units will be re-rated
to the uniform descriptor based on the new test procedure. This
conversion will not result in any increase in stringency of the energy
conservation standards. Therefore, no units that are on the market at
the time of this rulemaking will be made illegal (noncompliant) by this
action.
Accordingly, DOE concludes and certifies that this final rule would
not have a significant economic impact on a substantial number of small
entities, so DOE has not prepared a regulatory flexibility analysis for
this rulemaking. DOE will provide its certification and supporting
statement of factual basis to the Chief Counsel for Advocacy of the SBA
for review under 5 U.S.C. 605(b).
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of water heaters must certify to DOE that their
products comply with any applicable energy conservation standards. In
certifying compliance, manufacturers must test their products according
to the DOE test procedures for water heaters, including any amendments
adopted for those test procedures. DOE has established regulations for
the certification and recordkeeping requirements for all covered
consumer products and commercial equipment, including consumer and
commercial water heaters. 76 FR 12422 (March 7, 2011); 79 FR 25486 (May
5, 2014). The collection-of-information requirement for the
certification and recordkeeping is subject to review and approval by
OMB under the Paperwork Reduction Act (PRA). This requirement has been
approved by OMB under OMB control number 1910-1400. Public reporting
burden for the certification is estimated to average 30 hours per
response, including the time for reviewing instructions, searching
existing data sources, gathering and maintaining the data needed, and
completing and reviewing the collection of information.
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
D. Review Under the National Environmental Policy Act of 1969
In this proposed rule, DOE proposes conversion factors to convert
results from existing efficiency and delivery capacity metrics (and
related energy conservation standard requirements) for consumer and
certain commercial water heaters to the uniform energy descriptor. DOE
has determined that this rule falls into a class of actions that are
categorically excluded from review under the National Environmental
Policy Act of 1969 (42 U.S.C. 4321 et seq.) and DOE's implementing
regulations at 10 CFR part 1021. Specifically, this proposed rule would
amend the existing rule without affecting the amount, quality or
distribution of energy usage, and, therefore, would not result in any
environmental impacts. Thus, this rulemaking is covered by Categorical
Exclusion A5 under 10 CFR part 1021, subpart D, which applies to any
rulemaking that interprets or amends an existing rule without changing
the environmental effect of that rule. Accordingly, neither an
environmental assessment nor an environmental impact statement is
required.
E. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 10,
1999) imposes certain requirements on agencies formulating and
implementing policies or regulations that preempt State law or that
have Federalism implications. The Executive Order requires agencies to
examine the constitutional and statutory authority supporting any
action that would limit the policymaking discretion of the States and
to carefully assess the necessity for such actions. The Executive Order
also requires agencies to have an accountable process to ensure
meaningful and timely input by State and local officials in the
development of regulatory policies that have Federalism implications.
On March 14, 2000, DOE published a statement of policy describing the
intergovernmental consultation process it will follow in the
development of such regulations. 65 FR 13735. DOE has examined this
proposed rule and has determined that it would not have a substantial
direct effect on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. EPCA governs
and prescribes Federal preemption of State regulations as to energy
conservation for the products that are the subject of this proposed
rule. States can petition DOE
[[Page 20140]]
for exemption from such preemption to the extent, and based on
criteria, set forth in EPCA. (42 U.S.C. 6297(d)) No further action is
required by Executive Order 13132.
F. Review Under Executive Order 12988
Regarding the review of existing regulations and the promulgation
of new regulations, section 3(a) of Executive Order 12988, ``Civil
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal
agencies the general duty to adhere to the following requirements: (1)
Eliminate drafting errors and ambiguity; (2) write regulations to
minimize litigation; (3) provide a clear legal standard for affected
conduct rather than a general standard; and (4) promote simplification
and burden reduction. Regarding the review required by section 3(a),
section 3(b) of Executive Order 12988 specifically requires that
Executive agencies make every reasonable effort to ensure that the
regulation: (1) Clearly specifies the preemptive effect, if any; (2)
clearly specifies any effect on existing Federal law or regulation; (3)
provides a clear legal standard for affected conduct while promoting
simplification and burden reduction; (4) specifies the retroactive
effect, if any; (5) adequately defines key terms; and (6) addresses
other important issues affecting clarity and general draftsmanship
under any guidelines issued by the Attorney General. Section 3(c) of
Executive Order 12988 requires Executive agencies to review regulations
in light of applicable standards in sections 3(a) and 3(b) to determine
whether they are met or it is unreasonable to meet one or more of them.
DOE has completed the required review and determined that, to the
extent permitted by law, the proposed rule meets the relevant standards
of Executive Order 12988.
G. Review Under the Unfunded Mandates Reform Act of 1995
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA)
requires each Federal agency to assess the effects of Federal
regulatory actions on State, local, and Tribal governments and the
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531).
For a proposed regulatory action likely to result in a rule that may
cause the expenditure by State, local, and Tribal governments, in the
aggregate, or by the private sector of $100 million or more in any one
year (adjusted annually for inflation), section 202 of UMRA requires a
Federal agency to publish a written statement that estimates the
resulting costs, benefits, and other effects on the national economy.
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to
develop an effective process to permit timely input by elected officers
of State, local, and Tribal governments on a proposed ``significant
intergovernmental mandate,'' and requires an agency plan for giving
notice and opportunity for timely input to potentially affected small
governments before establishing any requirements that might
significantly or uniquely affect them. On March 18, 1997, DOE published
a statement of policy on its process for intergovernmental consultation
under UMRA. 62 FR 12820. (This policy is also available at https://energy.gov/gc/office-general-counsel.) DOE examined this proposed rule
according to UMRA and its statement of policy and determined that the
rule contains neither an intergovernmental mandate, nor a mandate that
may result in the expenditure by State, local, and Tribal governments,
in the aggregate, or by the private sector, of $100 million or more in
any year. Accordingly, no further assessment or analysis is required
under UMRA.
H. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family
Policymaking Assessment for any rule that may affect family well-being.
This rule would not have any impact on the autonomy or integrity of the
family as an institution. Accordingly, DOE has concluded that it is not
necessary to prepare a Family Policymaking Assessment.
I. Review Under Executive Order 12630
Pursuant to Executive Order 12630, ``Governmental Actions and
Interference with Constitutionally Protected Property Rights,'' 53 FR
8859 (March 18, 1988), DOE has determined that this regulation would
not result in any takings that might require compensation under the
Fifth Amendment to the U.S. Constitution.
J. Review Under Treasury and General Government Appropriations Act,
2001
Section 515 of the Treasury and General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most
disseminations of information to the public under information quality
guidelines established by each agency pursuant to general guidelines
issued by OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22,
2002), and DOE's guidelines were published at 67 FR 62446 (Oct. 7,
2002). DOE has reviewed this proposed rule under the OMB and DOE
guidelines and has concluded that it is consistent with applicable
policies in those guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355
(May 22, 2001), requires Federal agencies to prepare and submit to OIRA
at OMB, a Statement of Energy Effects for any proposed significant
energy action. A ``significant energy action'' is defined as any action
by an agency that promulgates or is expected to lead to promulgation of
a final rule, and that: (1) Is a significant regulatory action under
Executive Order 12866, or any successor order; and (2) is likely to
have a significant adverse effect on the supply, distribution, or use
of energy; or (3) is designated by the Administrator of OIRA as a
significant energy action. For any proposed significant energy action,
the agency must give a detailed statement of any adverse effects on
energy supply, distribution, or use should the proposal be implemented,
and of reasonable alternatives to the action and their expected
benefits on energy supply, distribution, and use.
This regulatory action, which would develop a conversion factor to
amend the energy conservation standards for consumer and certain
commercial water heaters in light of new test procedures is not a
significant regulatory action under Executive Order 12866 or any
successor order. Moreover, it would not have a significant adverse
effect on the supply, distribution, or use of energy, nor has it been
designated as a significant energy action by the Administrator of OIRA.
Therefore, it is not a significant energy action, and, accordingly, DOE
has not prepared a Statement of Energy Effects for this rulemaking.
L. Review Under Section 32 of the Federal Energy Administration Act of
1974
Under section 301 of the Department of Energy Organization Act
(Pub. L. 95-91; 42 U.S.C. 7101 et seq.), DOE must comply with all laws
applicable to the former Federal Energy Administration, including
section 32 of the Federal Energy Administration Act of 1974 (Pub. L.
93-275), as amended by the Federal Energy Administration Authorization
Act of 1977 (Pub. L. 95-70). (15 U.S.C. 788; FEAA) Section 32
essentially provides in relevant part
[[Page 20141]]
that, where a proposed rule authorizes or requires use of commercial
standards, the notice of proposed rulemaking must inform the public of
the use and background of such standards. In addition, section 32(c)
requires DOE to consult with the Attorney General and the Chairman of
the Federal Trade Commission (FTC) concerning the impact of the
commercial or industry standards on competition.
This proposed rule to implement conversion factors between the
existing water heaters test procedure and the amended test procedure
does not incorporate testing methods contained in commercial standards.
V. Public Participation
A. Submission of Comments
DOE will accept comments, data, and information regarding this
proposed rule no later than the date provided in the DATES section at
the beginning of this proposed rule. Interested parties may submit
comments, data, and other information using any of the methods
described in the ADDRESSES section at the beginning of this document.
Submitting comments via www.regulations.gov. The
www.regulations.gov Web page will require you to provide your name and
contact information. Your contact information will be viewable to DOE
Building Technologies staff only. Your contact information will not be
publicly viewable except for your first and last names, organization
name (if any), and submitter representative name (if any). If your
comment is not processed properly because of technical difficulties,
DOE will use this information to contact you. If DOE cannot read your
comment due to technical difficulties and cannot contact you for
clarification, DOE may not be able to consider your comment.
However, your contact information will be publicly viewable if you
include it in the comment itself or in any documents attached to your
comment. Any information that you do not want to be publicly viewable
should not be included in your comment, nor in any document attached to
your comment. Otherwise, persons viewing comments will see only first
and last names, organization names, correspondence containing comments,
and any documents submitted with the comments.
Do not submit to www.regulations.gov information for which
disclosure is restricted by statute, such as trade secrets and
commercial or financial information (hereinafter referred to as
Confidential Business Information (CBI)). Comments submitted through
www.regulations.gov cannot be claimed as CBI. Comments received through
the Web site will waive any CBI claims for the information submitted.
For information on submitting CBI, see the Confidential Business
Information section.
DOE processes submissions made through www.regulations.gov before
posting. Normally, comments will be posted within a few days of being
submitted. However, if large volumes of comments are being processed
simultaneously, your comment may not be viewable for up to several
weeks. Please keep the comment tracking number that www.regulations.gov
provides after you have successfully uploaded your comment.
Submitting comments via email, hand delivery/courier, or mail.
Comments and documents submitted via email, hand delivery/courier, or
mail also will be posted to www.regulations.gov. If you do not want
your personal contact information to be publicly viewable, do not
include it in your comment or any accompanying documents. Instead,
provide your contact information in a cover letter. Include your first
and last names, email address, telephone number, and optional mailing
address. The cover letter will not be publicly viewable as long as it
does not include any comments.
Include contact information each time you submit comments, data,
documents, and other information to DOE. If you submit via mail or hand
delivery/courier, please provide all items on a CD, if feasible, in
which case it is not necessary to submit printed copies. No
telefacsimiles (faxes) will be accepted.
Comments, data, and other information submitted to DOE
electronically should be provided in PDF (preferred), Microsoft Word or
Excel, WordPerfect, or text (ASCII) file format. Provide documents that
are not secured, that are written in English, and that are free of any
defects or viruses. Documents should not contain special characters or
any form of encryption and, if possible, they should carry the
electronic signature of the author.
Campaign form letters. Please submit campaign form letters by the
originating organization in batches of between 50 to 500 form letters
per PDF or as one form letter with a list of supporters' names compiled
into one or more PDFs. This reduces comment processing and posting
time.
Confidential Business Information. Pursuant to 10 CFR 1004.11, any
person submitting information that he or she believes to be
confidential and exempt by law from public disclosure should submit via
email, postal mail, or hand delivery/courier two well-marked copies:
one copy of the document marked ``confidential'' including all the
information believed to be confidential, and one copy of the document
marked ``non-confidential'' with the information believed to be
confidential deleted. Submit these documents via email or on a CD, if
feasible. DOE will make its own determination about the confidential
status of the information and treat it according to its determination.
Factors of interest to DOE when evaluating requests to treat
submitted information as confidential include: (1) A description of the
items; (2) whether and why such items are customarily treated as
confidential within the industry; (3) whether the information is
generally known by or available from other sources; (4) whether the
information has previously been made available to others without
obligation concerning its confidentiality; (5) an explanation of the
competitive injury to the submitting person which would result from
public disclosure; (6) when such information might lose its
confidential character due to the passage of time; and (7) why
disclosure of the information would be contrary to the public interest.
It is DOE's policy that all comments may be included in the public
docket, without change and as received, including any personal
information provided in the comments (except information deemed to be
exempt from public disclosure).
B. Issues on Which DOE Seeks Comment
Although DOE welcomes comments on any aspect of this proposal, DOE
is particularly interested in receiving comments and views of
interested parties concerning the following issues:
1. Has DOE identified all of the water heaters requiring a
conversion from the old test procedures for consumer and commercial
water heaters to the new test procedure for the uniform test method for
measuring the energy consumption of water heaters?
2. Are the proposed analytical methods appropriate for the
conversion factor analysis?
3. Is the proposed regression method appropriate for the conversion
factor analysis?
4. How do manufacturers specify whether a water heater is short or
tall? Is there any criteria that could be applied to compare short and
tall designs across all manufacturers?
5. Is the proposed percentage difference method appropriate for the
derivation of energy conservation
[[Page 20142]]
standards based on the updated test procedure?
VI. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this notice of
proposed rulemaking.
List of Subjects
10 CFR Part 429
Confidential business information, Energy conservation, Household
appliances, Imports, Reporting and recordkeeping requirements.
10 CFR Part 430
Administrative practice and procedure, Confidential business
information, Energy conservation, Household appliances, Imports,
Incorporation by reference, Intergovernmental relations, Small
businesses.
10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Test procedures, Incorporation by reference, Reporting and
recordkeeping requirements.
Issued in Washington, DC, on March 27, 2015.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy Efficiency, Energy Efficiency and
Renewable Energy.
For the reasons stated in the preamble, DOE is proposing to amend
parts 429, 430, and 431 of Chapter II, Subchapter D of Title 10, Code
of Federal Regulations, as set forth below:
PART 429--CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER
PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT
0
1. The authority citation for part 429 continues to read as follows:
Authority: 42 U.S.C. 6291-6317.
0
2. Section 429.17 is revised to read as follows:
Sec. 429.17 Water heaters.
(a) Determination of represented value.
(1) As of July 13, 2015, manufacturers must determine the
represented value for each new basic model of water heater by applying
an AEDM in accordance with 10 CFR 429.70 or by testing for the uniform
energy factor, in conjunction with the applicable sampling provisions
as follows:
(i) If the represented value is determined through testing, the
general requirements of 10 CFR 429.11 are applicable; and
(ii) For each basic model selected for testing, a sample of
sufficient size shall be randomly selected and tested to ensure that--
(A) Any represented value of the estimated annual operating cost or
other measure of energy consumption of a basic model for which
consumers would favor lower values shall be greater than or equal to
the higher of:
(1) The mean of the sample, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.019
and, x is the sample mean; n is the number of samples; and
xi is the ith sample;
Or,
(2) The upper 95-percent confidence limit (UCL) of the true mean
divided by 1.10, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.020
And xis the sample mean; s is the sample standard deviation; n is
the number of samples; and t0.95 is the t statistic for a
95-percent one-tailed confidence interval with n-1 degrees of freedom
(from Appendix A).
and
(B) Any represented value of the uniform energy factor, energy
factor, or other measure of energy consumption of a basic model for
which consumers would favor higher values shall be less than or equal
to the lower of:
(1) The mean of the sample, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.021
and, x is the sample mean; n is the number of samples; and
xi is the ith sample;
Or,
(2) The lower 95-percent confidence limit (LCL) of the true mean
divided by 0.90, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.022
And xis the sample mean; s is the sample standard deviation; n is the
number of samples; and t0.95 is the t statistic for a 95-
percent one-tailed confidence interval with n-1 degrees of freedom
(from Appendix A).
(2) For basic models initially certified before July 13, 2015
(using either the energy factor test procedure contained in Appendix E
to Subpart B of 10 CFR part 430 of the January 1, 2015 edition of the
Code of Federal Regulations or the thermal efficiency and standby loss
test procedures contained in 10 CFR 431.106 of the January 1, 2015
edition of the Code of Federal Regulations, in conjunction with
applicable sampling provisions), manufacturers must:
(i) Conduct testing for the uniform energy factor, in conjunction
with the applicable sampling provisions of this paragraph;
(ii) Apply an AEDM in accordance with 10 CFR 429.70; or
(iii) Calculate the uniform energy factor by applying the following
mathematical conversion factors to the previously certified value of
energy factor as follows. Representations of uniform energy factor
based on a calculation using this mathematical conversion factor must
be equal to the uniform energy factor value resulting from the
application of the appropriate equation below.
(A) The applicable mathematical conversion factors are as follows:
----------------------------------------------------------------------------------------------------------------
Product class Distinguishing criteria Conversion factor *
----------------------------------------------------------------------------------------------------------------
Consumer Gas-fired Water Heater. Non-Condensing, Standard New FHR = 1.0085 * FHREx
NOX. UEF = 0.4736 + 0.2726 * UEFWHAM
Non-Condensing, Low NOX. New FHR = 4.6894 = 0.9112 * FHREx
UEF = -0.0126 + 0.9966 * UEFWHAM
Non-Condensing, Ultra- New FHR = 2.9267 + 0.8882 * FHREx
Low NOX. UEF = 0.2673 + 0.5811 * UEFWHAM
Condensing.............. New FHR = -0.7072 + 0.9724 * FHREx
UEF = 0.0409 + 0.9164 * UEFWHAM
Consumer Oil-fired Water Heater. N/A..................... New FHR = 1.1018 * FHREx
UEF = -0.0945 + 1.1185 * UEFWHAM
Consumer Electric Water Heater.. Electric Resistance..... New FHR = 11.9239 + 0.789 * FHREx
UEF = 0.1227 + 0.8673 * UEFWHAM
[[Page 20143]]
Heat Pump............... New FHR = -2.3440 + 0.9856 * FHREx
UEF = -1.1235 + 1.5485 * EF
Tabletop Water Heater........... N/A..................... New FHR = 11.9239 + 0.7879 * FHREx
UEF = 0.1227 + 0.8673 * UEFWHAM
Instantaneous Gas-fired Water N/A..................... New Max GPM = 1.1467 * Max GPMEx
Heater. UEF = 0.0783 + 0.9052 * UEFmodel
Instantaneous Electric Water N/A..................... New Max GPM = 1.1467 * Max GPMEx
Heater. UEF = 1.0079 * UEFmodel
Residential-Duty Commercial Gas- N/A..................... New FHR = 39.8144 + 1.0226 * Q
fired Water Heater. UEF = 0.1413 + 0.7300 * UEFWHAM
Residential-Duty Commercial Oil- N/A..................... New FHR = 39.8144 + 1.0226 * Q
fired Water Heater. UEF = 0.1413 + 0.7300 * UEFWHAM
----------------------------------------------------------------------------------------------------------------
*FHREX = current first-hour rating.
Max GPMEX = current max GPM rating.
Q = nameplate input rate, in kBtu/hr.
UEFWHAM = the UEF predicted based on either the WHAM equation (for consumer storage water heaters) or the
modified WHAM (for residential-duty commercial water heaters, as defined in the sub-paragraphs below).
UEFmodel = the UEF predicted based on the analytical model developed by DOE (for consumer instantaneous water
heaters).
(B) Calculate UEFWHAM (for consumer storage water
heaters and residential-duty commercial storage water heaters) and
UEFmodel (for consumer instantaneous water heaters) as
follows:
(1) For consumer storage water heaters:
[GRAPHIC] [TIFF OMITTED] TP14AP15.023
Where a, b, c, and d are coefficients based on the applicable draw
pattern as specified in the table below; EF is the current energy
factor rating; [eta]r is the current recovery efficiency
rating in decimal form; and P is the input rating in Btu/h.
----------------------------------------------------------------------------------------------------------------
Draw pattern a b c d
----------------------------------------------------------------------------------------------------------------
Very Small.......................... 56095146 12884892499 8930623 15125743368
Low................................. 56095146 48962591496 33936368 57477824799
Medium.............................. 56095146 70866908744 49118427 83191588525
High................................ 56095146 108233096990 75017235 127056244293
----------------------------------------------------------------------------------------------------------------
(2) For consumer instantaneous water heaters:
[GRAPHIC] [TIFF OMITTED] TP14AP15.024
Where [eta]r is the current recovery efficiency rating expressed in
decimal form and A and B are coefficients dependent upon the applicable
draw pattern as specified in the table below.
------------------------------------------------------------------------
Draw pattern A B
------------------------------------------------------------------------
Very Small............................. 5514.2 170.2
Low.................................... 20954 262.4
Medium................................. 30328 290.9
High................................... 46319 294.0
------------------------------------------------------------------------
(3) For residential-duty commercial water heaters:
[GRAPHIC] [TIFF OMITTED] TP14AP15.025
Where, Et is the existing thermal efficiency rating; SL is
the existing standby loss rating in Btu/h; and C1 is a
coefficient as specified in the table below based on the applicable
draw pattern.
------------------------------------------------------------------------
Draw pattern C1
------------------------------------------------------------------------
Very Small.............................................. 3.575 x 10-3
Low..................................................... 9.408 x 10-4
Medium.................................................. 6.500 x 10-4
High.................................................... 4.256 x 10-4
------------------------------------------------------------------------
(3) Any represented value of the rated storage volume must be equal
to the mean of the measured storage volumes of all the units within the
sample.
(4) Any represented value of first-hour rating or maximum gallons
per minute (GPM) must be equal to the mean of the measured first-hour
ratings or measured maximum GPM ratings, respectively, of all the units
within the sample.
(b) Certification reports. (1) The requirements of 10 CFR 429.12
are applicable to water heaters; and
(2) Pursuant to 10 CFR 429.12(b)(13), a certification report shall
include the following public product-specific information:
(i) For storage-type water heater basic models tested for energy
factor and rated pursuant to 10 CFR 429.17(a)(2)(iii): Energy factor,
uniform energy factor, rated storage volume (gal), first-hour rating
(gal), and recovery efficiency (percent);
(ii) For storage-type water heater basic models tested for uniform
energy factor and rated pursuant to 10 CFR 429.17(a)(1) or 10 CFR
429.17(a)(2)(i) through (ii): Uniform energy factor, rated storage
volume in gallons (gal), first-hour rating (gal), and recovery
efficiency (percent);
(iii) For instantaneous-type water heater basic models tested for
energy factor and rated pursuant to 10 CFR 429.17(a)(2)(iii): Energy
factor, uniform energy factor, rated storage volume (gal), maximum
gallons per minute, and recovery efficiency (percent); and
[[Page 20144]]
(iv) For instantaneous-type water heater basic models tested for
uniform energy factor and rated pursuant to 10 CFR 429.17(a)(1) or 10
CFR 429.17(a)(2)(i) through (ii): Uniform energy factor, rated storage
volume (gal), maximum gallons per minute, and recovery efficiency
(percent).
0
3. Section 429.17 is further revised, effective [date one year after
publication of final rule], to read as follows:
Sec. 429.17 Water heaters.
(a) Determination of represented value. (1) Manufacturers must
determine the represented value for each water heater by applying an
AEDM in accordance with 10 CFR 429.70 or by testing for the uniform
energy factor, in conjunction with the applicable sampling provisions
as follows:
(i) If the represented value is determined through testing, the
general requirements of 10 CFR 429.11 are applicable; and
(ii) For each basic model selected for testing, a sample of
sufficient size shall be randomly selected and tested to ensure that--
(A) Any represented value of the estimated annual operating cost or
other measure of energy consumption of a basic model for which
consumers would favor lower values shall be greater than or equal to
the higher of:
(1) The mean of the sample, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.026
and, x is the sample mean; n is the number of samples; and
xi is the ith sample;
Or,
(2) The upper 95-percent confidence limit (UCL) of the true mean
divided by 1.10, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.027
And, x is the sample mean; s is the sample standard deviation; n is the
number of samples; and t0.95 is the t statistic for a 95-
percent one-tailed confidence interval with n-1 degrees of freedom
(from Appendix A).
and
(B) Any represented value of the uniform energy factor, energy
factor, or other measure of energy consumption of a basic model for
which consumers would favor higher values shall be less than or equal
to the lower of:
(1) The mean of the sample, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.028
and, x is the sample mean; n is the number of samples; and
xi is the ith sample;
Or,
(2) The lower 95-percent confidence limit (LCL) of the true mean
divided by 0.90, where:
[GRAPHIC] [TIFF OMITTED] TP14AP15.029
And x is the sample mean; s is the sample standard deviation; n is the
number of samples; and t0.95 is the t statistic for a 95-
percent one-tailed confidence interval with n-1 degrees of freedom
(from Appendix A).
(2) Any represented value of the rated storage volume must be equal
to the mean of the measured storage volumes of all the units within the
sample.
(3) Any represented value of first-hour rating or maximum gallons
per minute (GPM) must be equal to the mean of the measured first-hour
ratings or measured maximum GPM ratings, respectively, of all the units
within the sample.
(b) Certification reports. (1) The requirements of 10 CFR 429.12
are applicable to water heaters; and
(2) Pursuant to 10 CFR 429.12(b)(13), a certification report shall
include the following public product-specific information:
(i) For storage-type water heater basic models: Uniform energy
factor, rated storage volume in gallons (gal), first-hour rating (gal),
and recovery efficiency (percent);
(ii) For instantaneous-type water heater basic models: Uniform
energy factor, rated storage volume (gal), maximum gallons per minute,
and recovery efficiency (percent); and
(iii) For instantaneous-type water heater basic models: Uniform
energy factor, rated storage volume (gal), maximum gallons per minute,
and recovery efficiency (percent).
0
4. Section 429.44 is amended by:
0
a. Revising paragraph (a) introductory text;
0
b. Adding new paragraphs (c)(2)(vii) and (viii);
The revisions and additions read as follows:
Sec. 429.44 Commercial water heating equipment.
(a) For residential-duty commercial water heaters, determine
representations as provided in 10 CFR 429.17(a).
* * * * *
(c) * * *
(2) * * *
(vii) Residential-duty commercial gas-fired and oil-fired storage
water heaters tested for thermal efficiency and standby loss and rated
pursuant to 10 CFR 429.17(a)(2)(iii): Thermal efficiency in percent
(%), maximum standby loss in British thermal units per hour (Btu/h),
uniform energy factor, rated storage volume (gal), and the nameplate
input rate in British thermal units per hour (Btu/h).
(viii) Residential-duty commercial gas-fired and oil-fired storage
water heaters tested for uniform energy factor and rated pursuant to 10
CFR 429.17(a)(1) or 10 CFR 429.17(a)(2)(i) through (ii): Uniform energy
factor, rated storage volume (gal), first-hour rating (gal), and
recovery efficiency (percent).
* * * * *
0
5. Section 429.44 is further revised, effective [date one year after
publication of final rule], to read as follows:
0
a. Removing paragraph (c)(2)(vii);
0
b. Redesignating paragraph (c)(2)(viii) as (c)(2)(vii); and
0
c. Revising newly redesignated paragraph (c)(2)(vii) to read as
follows:
Sec. 429.44 Commercial water heating equipment.
* * * * *
(c) * * *
(2) * * *
(vii) Residential-duty commercial gas-fired and oil-fired storage
water heaters: Uniform energy factor, rated storage volume (gal),
first-hour rating (gal), and recovery efficiency (percent).
* * * * *
PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS
0
6. The authority citation for part 430 continues to read as follows:
Authority: 42 U.S.C. 6291-6309; 28 U.S.C. 2461 note.
0
7. Section 430.23 is amended by revising paragraph (e) to read as
follows:
Sec. 430.23 Test procedures for the measurement of energy and water
consumption.
* * * * *
(e) Water Heaters. (1) For water heaters tested using energy
factor:
(i) The estimated annual operating cost for water heaters tested in
terms of energy factor shall be--
(A) For a gas or oil water heater, the product of the annual energy
consumption, determined according to section 6.1.8 or 6.2.5 of appendix
E to subpart B of 10 CFR part 430 of the January 1, 2015 edition of the
Code of Federal Regulations, times the representative average unit cost
of gas or oil, as appropriate, in dollars per Btu as provided by the
Secretary. The resulting product shall be rounded off to the nearest
dollar per year.
[[Page 20145]]
(B) For an electric water heater, the product of the annual energy
consumption, determined according to section 6.1.8 or 6.2.5 of appendix
E to subpart B to 10 CFR part 430 of the January 1, 2015 edition of the
Code of Federal Regulations, times the representative average unit cost
of electricity in dollars per kilowatt-hour as provided by the
Secretary, divided by 3412 Btu per kilowatt-hour. The resulting
quotient shall be rounded off to the nearest dollar per year.
(ii) For an individual test, the tested energy factor for a water
heater shall be determined by section 6.1.7 or 6.2.4 of appendix E to
subpart B of 10 CFR part 430 of the January 1, 2015 edition of the Code
of Federal Regulations, rounded off to the nearest 0.01.
(2) For water heaters tested using uniform energy factor:
(i) The estimated annual operating cost shall be:
(A) For a gas or oil water heater, the sum of: The product of the
annual gas or oil energy consumption, determined according to section
6.1.10 or 6.2.7 of appendix E of this subpart, times the representative
average unit cost of gas or oil, as appropriate, in dollars per Btu as
provided by the Secretary; plus the product of the annual electric
energy consumption, determined according to section 6.1.9 or 6.2.6 of
appendix E of this subpart, times the representative average unit cost
of electricity in dollars per kilowatt-hour as provided by the
Secretary. The resulting sum shall be rounded off to the nearest dollar
per year.
(B) For an electric water heater, the product of the annual energy
consumption, determined according to section 6.1.9 or 6.2.6 of appendix
E of this subpart, times the representative average unit cost of
electricity in dollars per kilowatt-hour as provided by the Secretary.
The resulting product shall be rounded off to the nearest dollar per
year.
(ii) For an individual test, the tested uniform energy factor for a
water heater shall be determined by section 6.1.7 or 6.2.4 of appendix
E of this subpart, rounded to the nearest 0.01.
* * * * *
0
8. Section 430.32 is amended by revising paragraph (d) to read as
follows:
Sec. 430.32 Energy and water conservation standards and their
compliance dates.
* * * * *
(d) Water heaters. The energy factor of each basic model of water
heater shall not be less than the following:
----------------------------------------------------------------------------------------------------------------
Rated storage Uniform energy factor as of July
Product class volume Draw pattern 13, 2015*
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage............. >= 20 gal and <= Very Small............... 0.3263-(0.0019 x Vr)
55 gal.
Low...................... 0.5891-(0.0019 x Vr)
Medium................... 0.6326-(0.0013 x Vr)
High..................... 0.7128-(0.0025 x Vr)
< 55 gal and <= Very Small............... 0.5352-(0.0007 x Vr)
100 gal.
Low...................... 0.7375-(0.0009 x Vr)
Medium................... 0.7704-(0.0010 x Vr)
High..................... 0.7980-(0.0010 x Vr)
Oil-fired Storage............. <= 50 gal........ Very Small............... 0.2267-(0.0014 x Vr)
Low...................... 0.4867-(0.0006 x Vr)
Medium................... 0.6016-(0.0012 x Vr)
High..................... 0.6529-(0.0005 x Vr)
Electric Storage.............. >= 20 gal and <= Very Small............... 0.8268-(0.0002 x Vr)
55 gal.
Low...................... 0.9393-(0.0004 x Vr)
Medium................... 0.9683-(0.0007 x Vr)
High..................... 0.9656-(0.0004 x Vr)
< 55 gal and <= Very Small............... 1.2701-(0.0011 x Vr)
120 gal.
Low...................... 1.9137-(0.0011 x Vr)
Medium................... 2.0626-(0.0011 x Vr)
High..................... 2.1858-(0.0011 x Vr)
Tabletop Storage.............. >= 20 gal and <= Very Small............... 0.6808-(0.0022 x Vr)
100 gal.
Low...................... 0.8770-(0.0012 x Vr)
Medium................... 0.9063-(0.0009 x Vr)
High..................... 0.9302-(0.0006 x Vr)
Gas-fired Instantaneous....... < 2 gal.......... All...................... 0.8036-(0.0019 x Vr)
Electric Instantaneous........ < 2 gal.......... All...................... 0.9192-(0.0013 x Vr)
----------------------------------------------------------------------------------------------------------------
*Vr is rated storage volume.
* * * * *
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
9. The authority citation for part 431 continues to read as follows:
Authority: 42 U.S.C. 6291-6317.
0
10. In Sec. 431.106 revise paragraph (b) to read as follows:
Sec. 431.106 Uniform test method for the measurement of energy
efficiency of commercial water heaters and hot water supply boilers
(other than commercial heat pump water heaters).
* * * * *
(b) Testing and Calculations. Determine the energy efficiency of
each class of equipment by conducting the applicable test procedure(s),
set forth in the three rightmost columns of the following table:
[[Page 20146]]
Table 1 to Sec. 431.106--Test Procedures for Commercial Water Heaters and Hot Water Supply Boilers (Other Than
Commercial Heat Pump Water Heaters)
----------------------------------------------------------------------------------------------------------------
Test procedure
Energy efficiency required for With these additional
Equipment type descriptor Test procedure compliance on and stipulations
after
----------------------------------------------------------------------------------------------------------------
Residential-Duty Commercial Uniform Energy 10 CFR Part 430, July 13, 2015....
Water Heater. Factor. Subpart B,
Appendix E.
Gas-fired Storage and Thermal Use test set-up, May 13, 2013..... A. For all products,
Instantaneous Water Heaters Efficiency. equipment, and the duration of the
and Hot Water Supply Boilers. procedures in standby loss test
subsection shall be until
labeled ``Method whichever of the
of Test'' of following occurs
ANSI Z21.10.3- first after you begin
2011**, Exhibit to measure the fuel
G1. and/or electric
consumption: (1) The
first cut-out after
24 hours or (2) 48
hours, if the water
heater is not in the
heating mode at that
time.
Standby Loss..... Use test set-up, May 13, 2013..... B. For oil and gas
equipment, and products, the standby
procedures in loss in Btu per hour
subsection must be calculated as
labeled ``Method follows: SL (Btu per
of Test'' of hour) = S (% per
ANSI Z21.10.3- hour) x 8.25 (Btu/gal-
2011**, Exhibit F) x Measured Volume
G2. (gal) x 70 (degrees
F).
Oil-fired Storage and Thermal ANSI Z21.10.3- May 13, 2013..... C. For oil-fired
Instantaneous Water Heaters Efficiency. 2011**, Exhibit products, apply the
and Hot Water Supply Boilers. G1. following in
conducting the
thermal efficiency
and standby loss
tests: (1) Venting
Requirements--Connect
a vertical length of
flue pipe to the flue
gas outlet of
sufficient height so
as to meet the
minimum draft
specified by the
manufacturer. (2) Oil
Supply--Adjust the
burner rate so that:
(a) The hourly Btu
input rate lies
within 2
percent of the
manufacturer's
specified input rate,
(b) the CO2 reading
shows the value
specified by the
manufacturer, (c)
smoke in the flue
does not exceed No. 1
smoke as measured by
the procedure in ASTM-
D2156-80 (reference
for guidance only,
see Sec. 431.104),
and (d) fuel pump
pressure lies within
10
percent of
manufacturer's
specifications.
Standby Loss..... Use test set-up, May 13, 2013.....
equipment, and
procedures in
subsection
labeled ``Method
of Test'' of
ANSI Z21.10.3-
2011**, Exhibit
G2.
Electric Storage and Standby Loss..... Use test set-up, May 13, 2013..... D. For electric
Instantaneous Water Heaters. equipment, and products, apply the
procedures in following in
subsection conducting the
labeled ``Method standby loss test:
of Test'' of (1) Assume that the
ANSI Z21.10.3- thermal efficiency
2011**, Exhibit (Et) of electric
G2. water heaters with
immersed heating
elements is 98
percent. (2) Maintain
the electrical supply
voltage to within
5 percent
of the center of the
voltage range
specified on the
water heater
nameplate. (3) If the
set up includes
multiple adjustable
thermostats, set the
highest one first to
yield a maximum water
temperature in the
specified range as
measured by the
topmost tank
thermocouple. Then
set the lower
thermostat(s) to
yield a maximum mean
tank temperature
within the specified
range.
E. Install water-tube
water heaters as
shown in Figure 2,
``Arrangement for
Testing Water-tube
Type Instantaneous
and Circulating Water
Heaters.''
----------------------------------------------------------------------------------------------------------------
** Incorporated by reference, see Sec. 431.105.
[[Page 20147]]
0
11. Section 431.110 is revised to read as follows:
Sec. 431.110 Energy conservation standards and their effective dates.
Each commercial storage water heater, instantaneous water heater,
unfired hot water storage tank and hot water supply boiler \1\ (except
for residential-duty commercial water heaters) must meet the applicable
energy conservation standard level(s) as follows:
---------------------------------------------------------------------------
\1\Any packaged boiler that provides service water, that meets
the definition of ``commercial packaged boiler'' in subpart E of
this part, but does not meet the definition of ``hot water supply
boiler'' in subpart G, must meet the requirements that apply to it
under subpart E.
----------------------------------------------------------------------------------------------------------------
Energy conservation standard \a\ (products
manufactured on and after October 29, 2003) \b\
Product Size -------------------------------------------------
Minimum thermal Maximum standby loss
efficiency \c\
----------------------------------------------------------------------------------------------------------------
Electric storage water heaters....... All.................... N/A.................... 0.30 + 27/Vm (%/hr)
Gas-fired storage water heaters...... <=155,000 Btu/hr....... 80%.................... Q/800 + 110(Vr)\1/2\
(Btu/hr)
>155,000 Btu/hr....... 80%.................... Q/800 + 110(Vr)\1/2\
(Btu/hr)
Oil-fired storage water heaters...... <=155,000 Btu/hr....... 78%.................... Q/800 + 110(Vr)\1/2\
(Btu/hr)
>155,000 Btu/hr....... 78%.................... Q/800 + 110(Vr)\1/2\
(Btu/hr)
Gas-fired instantaneous water heaters <10 gal................ 80%.................... N/A
and hot water supply boilers.
>=10 gal.............. 80%.................... Q/800 + 110(Vr)\1/2\
(Btu/hr)
Oil-fired instantaneous water heaters <10 gal................ 80%.................... N/A
and hot water supply boilers.
>=10 gal.............. 78%.................... Q/800 + 110(Vr)\1/2\
(Btu/hr)
----------------------------------------------------------------------------------------------------------------
Product Size Minimum thermal insulation
----------------------------------------------------------------------------------------------------------------
Unfired hot water storage tank....... All.................... R-12.5.................
----------------------------------------------------------------------------------------------------------------
\a\Vm is the measured storage volume and Vr is the rated volume, both in gallons. Q is the nameplate input rate
in Btu/hr.
\b\ For hot water supply boilers with a capacity of less than 10 gallons: (1) the standards are mandatory for
products manufactured on and after October 21, 2005, and (2) products manufactured prior to that date, and on
or after October 23, 2003, must meet either the standards listed in this table or the applicable standards in
subpart E of this part for a ``commercial packaged boiler.''
\c\ Water heaters and hot water supply boilers having more than 140 gallons of storage capacity need not meet
the standby loss requirement if (1) the tank surface area is thermally insulated to R-12.5 or more, (2) a
standing pilot light is not used and (3) for gas or oil-fired storage water heaters, they have a fire damper
or fan assisted combustion.
Each residential-duty commercial water heater, as defined in 10 CFR
431.102, must meet the applicable energy conservation standard level as
follows:
----------------------------------------------------------------------------------------------------------------
Product class Draw pattern Uniform energy factor*
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage.................... Very Small..................... 0.3261-(0.0006 x Vr)
Low............................ 0.5219-(0.0008 x Vr)
Medium......................... 0.5585-(0.0006 x Vr)
High........................... 0.6044-(0.0005 x Vr)
Oil-fired Storage.................... Very Small..................... 0.3206-(0.0006 x Vr)
Low............................ 0.5577-(0.0019 x Vr)
Medium......................... 0.6027-(0.0019 x Vr)
High........................... 0.5446-(0.0018 x Vr)
----------------------------------------------------------------------------------------------------------------
* Vr is the rated storage volume.
[FR Doc. 2015-07932 Filed 4-13-15; 8:45 am]
BILLING CODE 6450-01-P
