Energy Conservation Program for Consumer Products and Certain Commercial and Industrial Equipment: Test Procedures for Consumer and Commercial Water Heaters, 59735-59798 [2016-20097]
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Vol. 81
Tuesday,
No. 168
August 30, 2016
Part II
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. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
DEPARTMENT OF ENERGY
10 CFR Parts 429, 430, and 431
[Docket No. 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: Supplemental notice of
proposed rulemaking.
AGENCY:
The U.S. Department of
Energy (DOE) proposes to establish a
mathematical conversion factor to
translate the current energy
conservation standards and the
measured values determined under the
energy factor, thermal efficiency, and
standby loss test procedures for
consumer water heaters and certain
commercial water heaters to those
determined under the more recently
adopted uniform energy factor test
procedure. As required by the Energy
Policy and Conservation Act of 1975
(EPCA), as amended, DOE initially
presented proposals for establishing a
mathematical conversion factor in a
notice of proposed rulemaking (NOPR)
published on April 14, 2015 (April 2015
NOPR). Upon further analysis and
review of the public comments received
in response to the April 2015 NOPR,
DOE is publishing this supplemental
notice of proposed rulemaking
(SNOPR), which: updates the proposed
mathematical conversion factors based
on new test data received after the
publication of the April 2015 NOPR;
proposes updates to the methodology
for developing the conversions for
certain covered water heaters based on
feedback received from interested
parties; and proposes a new approach
for denominating the existing energy
conservation standards in terms of the
new uniform energy factor (UEF) metric.
DATES: Comments: DOE will accept
comments, data, and information
regarding this SNOPR submitted no
later than September 29, 2016. See
section V, ‘‘Public Participation,’’ for
details.
ADDRESSES: All comments submitted
must identify the SNOPR for Test
Procedures for the Conversion Factor for
Consumer and Certain Commercial
Water Heaters, and provide docket
number EERE–2015–BT–TP–0007 and/
or regulatory information number (RIN)
1904–AC91. Comments may be
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SUMMARY:
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submitted using any of the following
methods:
1. Federal eRulemaking Portal:
www.regulations.gov. Follow the
instructions for submitting comments.
2. 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.
3. Postal Mail: Ms. Ashley Armstrong,
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.
4. Hand Delivery/Courier: Ms. Ashley
Armstrong, U.S. Department of Energy,
Building Technologies Office, 950
L’Enfant Plaza SW., Room 6094,
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, which includes
Federal Register notices, public meeting
attendee lists and transcripts,
comments, and other supporting
documents/materials, is available for
review at www.regulations.gov. All
documents in the docket are listed in
the www.regulations.gov index.
However, not all documents listed in
the index may be publicly available,
such as those containing information
that is exempt from public disclosure.
A link to the docket Web page can be
found at: https://www.regulations.gov/
docket?D=EERE–2015–BT–TP–0007.
This Web page contains a link to the
docket for this notice 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.
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.
FOR FURTHER INFORMATION CONTACT:
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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 Supplemental Notice of
Proposed Rulemaking
III. Discussion
A. Purpose
B. Scope
C. Approaches for Developing Conversions
1. Overview of Analytical Methods
Approach
2. Overview of Empirical Regression
Approach
3. Overview of Hybrid Approach
4. Analytical Methods Approach
a. Maximum GPM
b. First-Hour Rating
c. Uniform Energy Factor
i. Consumer Storage Water Heaters
ii. Consumer Instantaneous Water Heater
iii. Residential-Duty Commercial Storage
Water Heaters
iv. Residential-Duty Commercial Electric
Instantaneous Water Heaters
5. Empirical Regression Approach
D. Testing Conducted for the Mathematical
Conversion
1. Repeatability
E. Testing Results and Analysis of Test
Data
1. Impact of Certain Water Heater
Attributes on Efficiency Ratings
2. Conversion Factor Derivation
a. Consumer Storage Water Heaters
i. Test Results
ii. Conversion Factor Results
b. Consumer Instantaneous Water Heaters
i. Test Results
ii. Conversion Factor Results
c. Residential-Duty Commercial Storage
Water Heaters
i. Test Results
ii. Conversion Factor Results
d. Residential-Duty Commercial
Instantaneous Water Heaters
e. Grid-Enabled Storage Water Heaters
3. Energy Conservation Standard
Derivation
a. Storage Volume Used for Calculations
F. Compliance and Grandfathering
G. Certification
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
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I. Review Under Executive Order 12630
J. Review Under Treasury and General
Government Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal
Energy Administration Act of 1974
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, DOE’s energy
conservation program generally consists
of four parts: (1) Testing; (2) labeling; (3)
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 certain equipment
comply with any relevant standards
promulgated under EPCA. (42 U.S.C.
6295(s); 42 U.S.C. 6314)
EPCA 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);
6313(a)(6)(B)(iii)(I)) Also, the Secretary
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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); 6313(a)(6)(B)(iii)(II))
EPCA prescribed the energy
conservation standards for consumer
water heaters, shown in Table I.1 (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.
TABLE I.1—EPCA INITIAL ENERGY CONSERVATION STANDARDS FOR CONSUMER WATER HEATERS
Product class
Energy factor
Gas Water Heater ........................................................
Oil Water Heater ..........................................................
Electric Water Heater ..................................................
On October 17, 1990, DOE published
a final rule which updated the test
procedure from a no-draw test to a sixdraw, 24-hour simulated-use test. 55 FR
42162. The effect of this change in test
procedure was investigated on a sample
of representative units and based on the
results of testing on those units, DOE
updated the energy conservation
standard for electric water heaters to
reflect the new test procedure. To
account for the change in test procedure
for electric water heaters, DOE amended
the standard to 0.93¥(0.00132 × Rated
Storage Volume). Id. at 42177. DOE
0.62 ¥ (0.0019 × Rated Storage Volume in gallons).
0.59 ¥ (0.0019 × Rated Storage Volume in gallons).
0.95 ¥ (0.00132 × Rated Storage Volume in gallons).
notes that these statutory energy
conservation standards apply to both
storage and instantaneous consumer
water heaters regardless of volume
capacity.
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
specified classes of consumer water
heaters, and maintained the existing
energy conservation standards for
tabletop and electric instantaneous
water heaters. 75 FR 20112. The
standards adopted by the April 2010
final rule are shown below in Table I.2.
These standards apply to all water
heater product classes listed in Table I.2
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.2—DOE ENERGY CONSERVATION STANDARDS FOR CONSUMER WATER HEATERS
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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 ..................................................
Oil-fired Storage ..............................
Electric Storage ...............................
1 For editorial reasons, upon codification in the
U.S. Code, Part B was redesignated Part A.
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Energy factor **
0.675 ¥ (0.0015 × Vs).
0.8012 ¥ (0.00078 × Vs).
0.68 ¥ (0.0019 × Vs).
0.96 ¥ (0.0003 × Vs).
2 All references to EPCA in this document refer
to the statute as amended through the Energy
Efficiency Improvement Act of 2015 (EEIA 2015),
Public Law 114–11 (April 30, 2015).
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3 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
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TABLE I.2—DOE ENERGY CONSERVATION STANDARDS FOR CONSUMER WATER HEATERS—Continued
Product class
Rated storage volume ***
Energy factor **
Tabletop* .........................................
Gas-fired Instantaneous ..................
Electric Instantaneous * ...................
>55 gal and ≤120 gal ................................................
≥20 gal and ≤120 gal ................................................
<2 gal .........................................................................
<2 gal .........................................................................
2.057 ¥ (0.00113 × Vs).
0.93 ¥ (0.00132 × Vs).
0.82 ¥ (0.0019 × Vs).
0.93 ¥ (0.00132 × Vs).
* Tabletop and electric instantaneous water heater 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).
Water heaters that use gas, oil,
electricity, or a combination of these
fuels, that are not within the rated
storage volume sizes stated in Table I.2
(e.g., gas-fired storage less than 20
gallons or greater than 100 gallons), are
subject to the applicable energy
conservation standard established in
EPCA.
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
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)) The
statute was subsequently amended to
require DOE to review its standards for
commercial water heaters (and other
‘‘ASHRAE equipment’’) every six years.
(42 U.S.C. 6313(a)(6)(C)) On January 12,
2001, DOE published a final rule for
commercial water heating equipment
that amended energy conservation
standards by adopting the levels in
ASHRAE Standard 90.1–1999 for all
types of commercial water heating
equipment, except for electric storage
water heaters. 66 FR 3336. For electric
storage water heaters, the standard in
ASHRAE Standard 90.1–1999 was less
stringent than the standard prescribed
in EPCA and, consequently, would have
increased energy consumption, so DOE
maintained the standards for electric
storage water heaters at the statutorily
prescribed level. DOE published the
most recent final rule for commercial
water heating equipment on July 17,
2015, in which DOE adopted the
thermal efficiency level for oil-fired
storage water heaters that was included
in ASHRAE 90.1–2013. 80 FR 42614.
The current standards for commercial
water heating equipment are presented
in Table I.3.
TABLE I.3—ENERGY CONSERVATION STANDARDS FOR COMMERCIAL WATER HEATING EQUIPMENT
Energy conservation standards*
Minimum thermal
efficiency (equipment
manufactured on and
after October 9,
2015) ** † (%)
Equipment category
Size
Electric storage water heaters ................................
Gas-fired storage water heaters .............................
All ...................................
≤155,000 Btu/h ..............
>155,000 Btu/h ..............
≤155,000 Btu/h ..............
>155,000 Btu/h ..............
<10 gal ...........................
≥10 gal ...........................
<10 gal ...........................
N/A
80
80
80†
80†
80
77
80
0.30 + 27/Vm(%/h).
Q/800 + 110(Vr)1/2 (Btu/h).
Q/800 + 110(Vr)1/2 (Btu/h).
Q/800 + 110(Vr)1/2 (Btu/h).
Q/800 + 110(Vr)1/2 (Btu/h).
N/A.
2.30 + 67/Vm (%/h).
N/A.
≥10 gal ...........................
<10 gal ...........................
80
80
Q/800 + 110(Vr)1/2 (Btu/h).
N/A.
≥10 gal ...........................
78
Q/800 + 110(Vr)1/2 (Btu/h)
Oil-fired storage water heaters ...............................
Electric instantaneous water heaters††† .................
Gas-fired instantaneous water heaters and hot
water supply boilers.
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Oil-fired instantaneous water heater and hot water
supply boilers.
Maximum standby loss (equipment
manufactured on and after October
29, 2003)** ††
Equipment Category
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/h.
** For hot water supply boilers with a capacity of less than 10 gallons: (1) The standards are mandatory for units manufactured on and after
October 21, 2005 and (2) units manufactured on or after October 23, 2003, but prior to October 21, 2005, must meet either the standards listed
in this table or the applicable standards in Subpart E of this Part for a ‘‘commercial packaged boiler.’’
† For oil-fired storage water heaters: (1) The standards are mandatory for equipment manufactured on and after October 9, 2015, and (2)
equipment manufactured prior to that date must meet a minimum thermal efficiency level of 78 percent.
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†† 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-fired or oil-fired storage water heaters, they have a fire damper or fan-assisted combustion.
††† Energy conservation standards for electric instantaneous water heaters are included in EPCA. (42 U.S.C. 6313(a)(5)(D)–(E)) The compliance date for these energy conservation standards is January 1, 1994. In a NOPR for energy conservation standards for commercial water heating equipment published on May 31, 2016, DOE proposed to codify these standards for electric instantaneous water heaters in its regulations at
10 CFR 431.110. 81 FR 34440.
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 consumer water heaters and
certain commercial water heating
equipment 4 within one year of the
enactment of AEMTCA. (42 U.S.C.
6295(e)(5)(B)) The final rule must
replace the energy factor (EF), thermal
efficiency (TE), and standby loss (SL)
metrics with a uniform efficiency
descriptor. (42 U.S.C. 6295(e)(5)(C)) On
July 11, 2014, DOE published a final
rule that fulfilled these requirements. 79
FR 40542 (July 2014 final rule).
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 residentialduty 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 for
converting the measurement of
efficiency from the test procedures and
metrics in effect at that time to the
uniform efficiency descriptor. (42 U.S.C.
6295(e)(5)(E)(i)–(ii))
EPCA provides that any covered water
heater (i.e., under DOE’s rulemaking, all
consumer water heaters and residentialduty commercial water heaters)
manufactured prior to the effective date
of the UEF test procedure final rule (i.e.,
July 13, 2015) that complied with the
efficiency standards and labeling
requirements applicable at the time of
manufacture will be considered to
comply with the UEF test procedure
final rule and with any revised labeling
requirements established by the Federal
Trade Commission (FTC) to carry out
the UEF test procedure final rule. (42
U.S.C. 6295(e)(5)(K)) DOE’s
interpretation and application of this
4 The uniform efficiency descriptor and
accompanying test procedure apply to commercial
water heating equipment with residential
applications defined in the test procedure final rule
published July 11, 2014, as a ‘‘residential-duty
commercial water heater.’’ See 79 FR 40542, 40586.
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provision are discussed in detail in
Section III.F.
As noted previously, in the July 2014
final rule, DOE amended its test
procedure for consumer and certain
commercial water heaters. 79 FR 40542.
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 EF, TE, and SL metrics.
The amended test procedure includes
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) 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 were not
addressed by the previous test method);
and (2) commercial water heaters that
have residential applications. The major
modifications to the EF 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
all storage volumes, specifically by
including 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 definition for ‘‘residential-duty
commercial water heater’’ and recategorized certain commercial water
heaters into this class.
This rulemaking is intended to satisfy
the requirements of AEMTCA to
develop a mathematical conversion
factor for converting the EF, TE, and SL
metrics to the UEF metric. (42 U.S.C.
6295(e)(5)(E)) As an initial step in
conducting this rulemaking, DOE
published a notice of proposed
rulemaking on April 14, 2015, which
included proposed mathematical
conversion factors and proposed
updates to the energy conservation
standards. 80 FR 20116.
The Energy Efficiency Improvement
Act of 2015 (EEIA 2015) (Pub. L. 114–
11) was enacted on April 30, 2015.
Among other things, EEIA 2015 added
a definition of ‘‘grid-enabled water
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heater’’ to EPCA’s energy conservation
standards for consumer water heaters.
(42 U.S.C. 6295(e)(6)(A)(ii)) These
products are intended for use as part of
an electric thermal storage or demand
response program. One of the criteria in
EPCA that defines a ‘‘grid-enabled water
heater’’ is the requirement that it meet
a certain energy factor (specified by a
formula set forth in the statute), or an
equivalent alternative standard that
DOE may prescribe. Id. On August 11,
2015, DOE published a final rule in the
Federal Register to implement the
changes to EPCA by placing the energy
conservation standards and related
definitions in the Code of Federal
Regulations (CFR). 80 FR 48004. As the
energy conservation standard for gridenabled water heaters is in terms of
energy factor, DOE is addressing these
products in this notice to propose a
mathematical conversion and updated
energy conservation standard in terms
of UEF.
II. Summary of the Supplemental
Notice of Proposed Rulemaking
In this SNOPR, DOE proposes to
establish a mathematical conversion
factor between the values determined
using the EF, TE, and SL test procedures
(including the first-hour rating or
maximum gallons per minute (GPM)
rating, as applicable), and the values
that would be determined using the
uniform efficiency descriptor test
procedure established in the July 2014
final rule (i.e., UEF and first-hour rating
or maximum GPM rating). After further
analysis and review of the public
comments received in response to the
April 2015 NOPR, DOE is publishing
this SNOPR to: (1) Update the proposed
mathematical conversion factors based
on new test data received after the
publication of the April 2015 NOPR; (2)
propose to update the approaches
considered for developing the
conversion factors for standard and low
NOX non-condensing gas fired storage
water heaters, condensing storage water
heaters, tabletop water heaters, heat
pump water heaters and residentialduty water heaters; and (3) propose a
new approach for denominating the
existing energy conservation standards
in terms of the new uniform energy
factor metric.
Other than the specific amendments
newly proposed in this SNOPR, DOE
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continues to propose the amendments
originally included in the April 2015
NOPR. 80 FR 20116 (April 14, 2015).
For the reader’s convenience, DOE has
reproduced in this SNOPR the entire
body of latest proposed regulatory text
from the April 2015 NOPR, amended as
appropriate according to these
proposals. DOE’s supporting analysis
and discussion for the portions of the
proposed regulatory text not affected by
this SNOPR may be found in the April
2015 NOPR.
The mathematical conversion factor
required by AEMTCA is a bridge
between the values 5 obtained through
testing under the EF, TE, and SL test
procedures and those obtained under
the uniform efficiency descriptor test
procedure published in the July 2014
final rule. DOE conducted a series of
tests on the classes of water heaters
included within the scope of this
rulemaking (see section III.B for details
on the scope) and relied upon that test
data and test data submitted by
interested parties to develop the
proposals in this SNOPR. DOE used the
test data, along with the approaches
described in section III.C, to calculate
the conversion factors proposed in this
SNOPR. To develop conversion factors
for this SNOPR, DOE generally used the
same methodology as proposed in the
April 2015 NOPR (with several
exceptions discussed in more detail in
section III.E.2), and presents in this
document the updated conversion
factors based on the inclusion of
additional test data. Subsequently, DOE
used the conversion factors to derive
minimum energy conservation
standards in terms of UEF, as shown in
Table II.1 and Table II.2. For this
SNOPR, DOE adopted a new approach
to denominating the energy
conservation standards in terms of the
UEF metric, which is explained in detail
in section III.E.3. The proposed
standards denominated in UEF are
neither more nor less stringent than the
EF-denominated standards for consumer
water heaters (as amended by the April
2010 final rule) and for commercial
water-heating equipment based on the
thermal efficiency and standby loss
metrics.
TABLE II.1—PROPOSED CONSUMER WATER HEATER ENERGY CONSERVATION STANDARDS
Product class
Rated storage volume and input rating (if
applicable)
Draw pattern
Gas-fired Storage Water Heater ................
<20 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 .........................
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 .........................
≥20 gal and ≤55 gal ...................................
>55 gal and ≤100 gal ................................
>100 gal .....................................................
Oil-fired Storage Water Heater ..................
≤50 gal .......................................................
>50 gal .......................................................
Electric Storage Water Heaters .................
<20 gal .......................................................
≥20 gal and ≤55 gal ...................................
>55 gal and ≤120 gal ................................
mstockstill on DSK3G9T082PROD with PROPOSALS2
>120 gal .....................................................
Tabletop Water Heater ..............................
5 The term ‘‘represented values’’ includes all
efficiency or performance-related information
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All ...............................................................
included in product ratings, nameplates, public
representations (literature, product sheets, etc.).
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30AUP2
Uniform energy factor
0.2471¥(0.0002 × Vr).
0.5132¥(0.0012 × Vr).
0.5827¥(0.0015 × Vr).
0.6507¥(0.0019 × Vr).
0.3456¥(0.0020 × Vr).
0.5982¥(0.0019 × Vr).
0.6483¥(0.0017 × Vr).
0.6920¥(0.0013 × Vr).
0.6470¥(0.0006 × Vr).
0.7689¥(0.0005 × Vr).
0.7897¥(0.0004 × Vr).
0.8072¥(0.0003 × Vr).
0.1755¥(0.0006 × Vr).
0.4671¥(0.0015 × Vr).
0.5719¥(0.0018 × Vr).
0.6916¥(0.0022 × Vr).
0.1822¥(¥0.0001 × Vr).
0.5313¥(0.0014 × Vr).
0.6316¥(0.0020 × Vr).
0.7334¥(0.0028 × Vr).
0.1068¥(0.0007 × Vr).
0.4190¥(0.0017 × Vr).
0.5255¥(0.0021 × Vr).
0.6438¥(0.0025 × Vr).
0.7836¥(0.0013 × Vr).
0.8939¥(0.0008 × Vr).
0.9112¥(0.0007 × Vr).
0.9255¥(0.0006 × Vr).
0.8808¥(0.0008 × Vr).
0.9254¥(0.0003 × Vr).
0.9307¥(0.0002 × Vr).
0.9349¥(0.0001 × Vr).
1.9236¥(0.0011 × Vr).
2.0440¥(0.0011 × Vr).
2.1171¥(0.0011 × Vr).
2.2418¥(0.0011 × Vr).
0.6802¥(0.0003 × Vr).
0.8620¥(0.0006 × Vr).
0.9042¥(0.0007 × Vr).
0.9437¥(0.0007 × Vr).
0.6323¥(0.0058 × Vr).
0.9188¥(0.0031 × Vr).
0.9577¥(0.0023 × Vr).
0.9884¥(0.0016 × Vr).
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TABLE II.1—PROPOSED CONSUMER WATER HEATER ENERGY CONSERVATION STANDARDS—Continued
Product class
Rated storage volume and input rating (if
applicable)
Draw pattern
Instantaneous Gas-fired Water Heater ......
<2 gal and >50,000 Btu/h ..........................
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 .........................
≥2 gal or ≤50,000 Btu/h .............................
Instantaneous Oil-fired Water Heater ........
All ...............................................................
Instantaneous Electric Water Heater .........
All ...............................................................
Grid-Enabled Water Heater .......................
>75 gal .......................................................
Uniform energy factor
0.7964¥(0.0000
0.8055¥(0.0000
0.8070¥(0.0000
0.8086¥(0.0000
0.3013¥(0.0023
0.5421¥(0.0024
0.5942¥(0.0021
0.6415¥(0.0017
0.1430¥(0.0015
0.4455¥(0.0023
0.5339¥(0.0023
0.6245¥(0.0021
0.9161¥(0.0039
0.9159¥(0.0009
0.9160¥(0.0005
0.9161¥(0.0003
1.0136¥(0.0028
0.9984¥(0.0014
0.9853¥(0.0010
0.9720¥(0.0007
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
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 is 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 ..........................
Very Small ................
Low ...........................
Medium ....................
High ..........................
Oil-fired Storage ................................................................................................................
Electric Instantaneous .......................................................................................................
Uniform energy factor
0.2670—(0.0009
0.5356—(0.0012
0.5996—(0.0011
0.6592—(0.0009
0.2932—(0.0015
0.5596—(0.0018
0.6194—(0.0016
0.6740—(0.0013
0.80.
0.80.
0.80.
0.80.
×
×
×
×
×
×
×
×
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
mstockstill on DSK3G9T082PROD with PROPOSALS2
* Vr is the rated storage volume, which is the water storage capacity of a water heater (in gallons), as specified by the manufacturer.
The conversion factor formulas may
be used for one year beginning on the
date of publication of the conversion
factor final rule in the Federal Register.
After that time, all representations
regarding energy efficiency or energy
use must be based on testing (either
directly or through the application of an
AEDM, where permitted). In addition,
EPCA requires that a 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 FTC to
carry out the July 2014 final rule if that
water heater basic model was
manufactured prior to July 13, 2015, and
complied with the applicable efficiency
standards and labeling requirements in
effect prior to July 13, 2015. (See 42
U.S.C. 6295(e)(5)(K)) Sections III.F and
III.G explain that DOE intends to
address various issues related to the
transition from the metrics in effect
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prior to July 13, 2015, through the use
of enforcement policies.
III. Discussion
A. Purpose
As discussed in section I, DOE has
undertaken this rulemaking to establish
a mathematical conversion factor as a
result of requirements added to EPCA
by AEMTCA. (42 U.S.C. 6295(e)(5))
EPCA requires DOE to establish a
uniform efficiency descriptor for
consumer water heaters and commercial
water heaters, and to establish a
mathematical conversion factor to
translate from the EF, TE, and SL
descriptors to the uniform efficiency
descriptor established by DOE. Id. In the
July 2014 test procedure final rule, DOE
established UEF as the uniform
efficiency descriptor, and adopted a test
method for measuring UEF for
consumer and certain commercial water
heaters. 79 FR 40542 (July 11, 2014).
The current rulemaking addresses the
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mathematical conversion factor required
by EPCA (see 42 U.S.C. 6295(e)(5)(E))
and the requirement that the efficiency
standard be denominated according to
the uniform efficiency descriptor (i.e.,
UEF) (see 42 U.S.C. 6295(e)(5)(D)(i)).
Based on review of the test results
used to develop the mathematical
conversion factors, DOE has found that
different water heaters are impacted in
different ways by the new test method
and metric, depending on the specific
design and characteristics of the water
heater. Water heaters have numerous
attributes that impact energy efficiency
and performance, and the changes to the
test method and metrics impact each
water heater model differently, often in
ways that are difficult to predict. For
example, two electric water heaters with
the same rated storage volume, input
rating, first-hour rating, and energy
factor rating (all represented values
published under the EF test method as
indicators of water heater performance)
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have been shown by testing to have
different measured first-hour ratings and
uniform energy factors when tested
under the new test procedure.
Given the number of models currently
available in the market (756 unique
basic models as of September 2015), it
would not be practical to analyze each
model individually to determine the
change in represented values under the
new test procedure. Rather, DOE has
analyzed a subset of models that are
representative of the market as a whole
(see section III.D for further discussion
of the models tested for this rule). This
approach is consistent with the
statutory mandate, which instructs DOE
to develop ‘‘a mathematical conversion
factor.’’ (42 U.S.C. 6295(e)(5)(E)) DOE
recognizes that the phrase
‘‘mathematical conversion factor’’ does
not require DOE to generate a single
number applicable to all water heaters.
For one thing, DOE believes that,
despite the use of the word ‘‘factor,’’ in
the singular, the statute permits the use
of a conversion equation involving
several numbers and mathematical
operations besides multiplication. Still,
the phrasing suggests that DOE should
develop a formula that is broadly
applicable, rather than generate a table
of equivalencies stating the exact UEF
equivalent for every individual product
on the market.
Because each water heater is impacted
differently, it would be impossible to
develop a single equation, or reasonable
set of equations, that could be used to
model the energy performance of every
water heater exactly under the new test
method. Therefore, the purpose of this
mathematical conversion factor is to
develop an equation that will be able to
reasonably predict a water heater’s
energy efficiency under the UEF test
method based on values measured
under the EF, TE, or SL test methods for
that model.
Any mathematical conversion will
have some amount of residual difference
between predicted and measured values
that is inherent when applying a
mathematical equation (or multiple
equations for different types of water
heaters) to predict the energy efficiency
performance or delivery capacity of a
large set of models. In this rule, DOE has
sought to minimize the amount of
difference between predicted and actual
performance in several ways. DOE
incorporated as much test data as was
practical and available, and which
represented models currently on the
market (see section III.D). DOE
considered several attributes that could
have a large impact on the test results
under both the new and old metrics,
and included those as appropriate when
developing the mathematical
conversion, which led to a set of
equations for water heaters with certain
different characteristics (e.g., different
fuel types, different nitrogen oxide
(NOX) emissions levels). DOE also
explored several options for identifying
the most accurate methodologies for
developing the mathematical conversion
equations (see section III.C). In addition,
DOE sought feedback from interested
parties and incorporated suggestions for
improving the mathematical
conversions when the suggested
changes in approach resulted in
conversion equations that were better
predictors of actual measured
performance.
As noted previously, this rulemaking
also addresses the requirement that the
efficiency standard be denominated in
terms of UEF, and in this notice DOE
proposes energy conservation standard
levels using the UEF metric. (42 U.S.C.
6295(e)(5)(D)(i)) As discussed in section
I, DOE may not adopt a standard that
reduces the stringency of the existing
standards, due to the ‘‘anti-backsliding’’
clause. (42 U.S.C. 6295(o)(1);
6313(a)(6)(B)(iii)(I)) Further, EPCA
requires that the mathematical
conversion factor not affect the
minimum efficiency requirements. (42
U.S.C 6295(e)(5)(E)(iii)).
The methodology proposed in section
III.E.3 for translating the standards is
intended to ensure equivalent
stringency between the existing
standards (using EF, TE, and SL metrics)
and the proposed updated standards
(using UEF). Due to differences in water
heater performance under the different
test methods discussed in the preceding
paragraphs, some models will perform
better, and others worse, under the new
test method than they did under the
previous test method. Even though the
stringency with respect to a specific
model may vary based on the
characteristics and performance of that
model, the proposed approach for
translating the standard is designed to
maintain the same stringency for each
product class as a whole. Because DOE’s
goal is to maintain the same stringency
of the standards under the EF, TE, and
SL metrics (i.e., the standards in terms
of the new UEF metric are neither more
nor less stringent), and because
individual models are impacted
differentially by the change in test
method and metric, some models that
were previously minimally compliant
will perform better than the translated
UEF minimum, and others will perform
worse. The possibility of such outcomes
would not, by itself, mean that the
conversion methodology was improper.
As noted above, the possibility of some
deviation for individual products is
inherent in the use of a broad-based
conversion equation. However, because
the statute nonetheless mandates that
the Department develop a
‘‘mathematical conversion factor,’’ DOE
understands the statute to permit the
consequences that naturally follow from
that approach.
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 initially outlined the
scope of this rulemaking in the April
2015 NOPR. 80 FR 20116, 20122–24
(April 14, 2015). In summary, this
rulemaking includes all covered
consumer water heaters, as well as
commercial water heaters meeting the
definition of ‘‘residential-duty
commercial water heater.’’ In the NOPR,
DOE stated that it was not including
water heaters that were not previously
subject to the test procedures or
standards for energy factor established
in the Code of Federal Regulations in
the scope of the conversion factor, as
they are not required to be tested and
rated for efficiency under the DOE test
method. Id. Table III.1 lists the
consumer water heaters that, for this
reason, DOE did not propose a
mathematical conversion factor in the
NOPR.
TABLE III.1—CONSUMER WATER HEATERS NOT COVERED IN THE NOPR 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 ...........................................................................
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Rated
Rated
Rated
Rated
Rated
Storage Volume ≥2 gal and <20 gal or >100 gal.
Storage Volume >50 gal.
Storage Volume ≥2 gal and <20 gal or >120 gallons.
Storage Volume ≥2 gal and <20 gal or >120 gallons.
Input ≤50,000 Btu/h; Rated Storage Volume ≥2 gal.
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59743
TABLE III.1—CONSUMER WATER HEATERS NOT COVERED IN THE NOPR BY THE MATHEMATICAL CONVERSION FACTOR—
Continued
Product class
Description of criteria for exclusion from conversion rulemaking
Electric Instantaneous ..............................................................................
Oil-fired Instantaneous .............................................................................
DOE has further considered the
applicability of standards to the
products listed in Table III.1 and
proposes to clarify that the initial energy
conservation standards in EPCA, as
listed in Table I.1, are applicable to gasfired, electric, and tabletop water
heaters below 20 gallons storage
volume; gas-fired water heaters above
100 gallons storage volume; oil-fired
water heaters above 50 gallons storage
volume; electric and tabletop water
heaters above 120 gallons storage
volume; gas-fired instantaneous water
heaters with an input at or below 50,000
Btu/h or at or above 2 gallons storage
volume; electric instantaneous water
heaters at or above 2 gallons; and oilfired instantaneous water heaters. These
products were not considered in DOE’s
rulemakings that culminated in the
April 16, 2010 and January 17, 2001
final rules (75 FR 20112 and 66 FR
4474, respectively), and accordingly, the
standards adopted in those final rules
are not applicable to these products.
DOE notes that EPCA’s definitions for
consumer water heaters do not place
any limitation on the storage volume or
specify a minimum fuel input rate for
gas-fired instantaneous water heaters.
Thus, DOE has tentatively concluded
that the initial standards for water
heaters included in EPCA were
intended to cover all water heaters
meeting the definition of a ‘‘water
heater’’ at 42 U.S.C. 6291(27) and would
apply regardless of the storage volume,
and without a lower limit on the fuel
input rating for gas-fired instantaneous
water heaters.
Rated Storage Volume ≥2 gal.
All.
In this SNOPR, DOE used the
applicable conversion equations to
convert the EPCA-established standards
applicable to the products in Table III.1
from EF to UEF. For electric water
heaters, as discussed in section I, in the
October 17, 1990 test procedure final
rule, DOE determined that the standard
set by EPCA required adjustment under
42 U.S.C. 6293(e) due to the effect of the
change in test procedure. 55 FR 42162,
42164. DOE believes the impact on
measured energy characterized in the
October 1990 test procedure final rule
resulting from the change in the test
procedure is valid for all consumer
electric water heaters and not just those
limited to the gallon sizes specified in
the October 1990 test procedure final
rule. Accordingly, DOE has used the
standard level adopted in the 1990 test
procedure final rule for establishing
converted UEF standards for electric
water heaters with storage volumes
below 20 gallons and above 120 gallons.
DOE has found that oil-fired
instantaneous water heaters exist on the
market and are available for sale within
the United States. Oil-fired
instantaneous water heaters were not
defined under the EF test procedure, nor
were these products defined by DOE at
10 CFR 430.2 prior to the effective date
of the July 2014 test procedure final rule
that established the UEF metric.
However, oil-fired instantaneous water
heaters are defined by EPCA at 42
U.S.C. 6291(27)(B), were added to the
definitions at 10 CFR 430.2 in the July
2014 test procedure final rule, and are
covered by the UEF test procedure.
Because oil-fired instantaneous water
heaters were not previously tested to the
EF test procedure, a conversion factor is
not necessary (as manufacturers would
not have EF ratings to convert). Rather,
manufacturers of oil-fired instantaneous
water heaters who wish to make
representations of efficiency should test
to the UEF metric. However, DOE must
still convert the energy conservation
standard established by EPCA from EF
to UEF. The steps taken for this
conversion are explained in section
III.E.3.
As noted in section I, EPCA was
recently amended to define and set
efficiency requirements for grid-enabled
water heaters in terms of EF, so DOE has
included the development of a
conversion factor and updated standard
for these products in this SNOPR. DOE
has tentatively determined that these
products do not meet the criteria for
exclusion from the UEF metric.
Only commercial water heaters
meeting the definition of ‘‘residentialduty commercial water heater’’ are
subject to the uniform efficiency
descriptor test method, while all other
commercial water heaters are not. As a
result, this conversion only addresses
commercial water heaters that meet the
definition of ‘‘residential-duty
commercial water heater,’’ which
includes commercial water heaters that:
(1) For models requiring electricity,
uses single-phase power;
(2) Are not designed to provide outlet
hot water at temperatures greater than
180 °F; and
(3) Are 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 CONSUMER APPLICATIONS
(i.e., NON-RESIDENTIAL-DUTY)
mstockstill on DSK3G9T082PROD with PROPOSALS2
Water heater type
Indicator of non-consumer application
Gas-fired Storage .....................................................................................
Oil-fired Storage .......................................................................................
Electric Storage ........................................................................................
Gas-fired Instantaneous ...........................................................................
Electric Instantaneous ..............................................................................
Oil-fired Instantaneous .............................................................................
Additionally, DOE notes that for
several types of water heaters,
definitional criteria preclude their
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Rated
Rated
Rated
Rated
Rated
Rated
input
input
input
input
input
input
>105 kBtu/h; Rated storage volume >120 gal.
>140 kBtu/h; Rated storage volume >120 gal.
>12 kW; Rated storage volume >120 gal.
>200 kBtu/h; Rated storage volume >2 gal.
>58.6 kW; Rated storage volume >2 gal.
>210 kBtu/h; Rated storage volume >2 gal.
classification as residential-duty
commercial water heaters. For example,
an electric storage water heater with a
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rated input of greater than 12 kW would
not be a residential-duty commercial
water heater, as it is excluded under the
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definition of ‘‘residential-duty
commercial water heater’’ based on its
rated input; conversely, an input rating
at or below 12 kW would place an
electric storage water heater in the
consumer water heater category under
EPCA. (See 42 U.S.C. 6291(27)(A)).
Therefore, there is no input rating at
which an electric storage water heater
would be classified as a residential-duty
commercial water heater. Similarly,
EPCA defines gas-fired instantaneous
water heaters with an input of 200,000
Btu per hour or less, oil-fired
instantaneous water heaters with an
input of 210,000 Btu per hour or less,
and heat pump type water heaters with
a rated input of 12 kW or less, or a rated
current of 24 amps or less at a rated
voltage of not greater than 250 volts, as
consumer water heaters. (42 U.S.C.
6291(27)(B)). The residential-duty
commercial water heater criteria in
Table III.2 exclude models with input
rates above the input limits from being
residential-duty commercial water
heaters. Any water heaters above the
applicable limits would be considered
non-residential-duty commercial water
heaters, and any water heaters at or
below the applicable limits would be
consumer water heaters. Therefore, in a
NOPR for test procedures for certain
commercial water heating equipment
published on May 9, 2016 (‘‘May 2016
CWH TP NOPR’’), DOE is proposing to
expressly exclude these four classes—
electric storage water heaters, heat
pump water heaters, gas-fired
instantaneous water heaters, and oilfired instantaneous water heaters—from
the definition for ‘‘residential-duty
commercial water heater’’ codified at 10
CFR 431.102. 81 FR 28588, 28607,
28637. Consequently, a mathematical
conversion and a standard in terms of
UEF are only necessary for the types of
water heaters that can be defined as
residential-duty commercial water
heaters: gas-fired storage water heaters,
oil-fired storage water heaters, and
electric instantaneous water heaters.
In response to the April 2015 NOPR
proposals, Air-Conditioning, Heating,
and Refrigeration Institute (AHRI)
commented that residential-duty
commercial electric storage water
heaters should have a conversion
because electric water heaters that were
designed with input rates less than or
equal to 12 kW and deliver water at
temperatures of 180 °F were previously
(i.e., before changes to the DOE
definition for ‘‘electric storage water
heater’’ were adopted in the July 2014
test procedure final rule) not considered
to be consumer products. (AHRI, No. 13
at p. 6) As discussed in the preceding
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paragraph, there are no electric storage
water heaters that would be classified as
residential-duty commercial water
heaters. EPCA includes as consumer
electric storage water heaters those
having an input rating less than or equal
to 12 kW and does not distinguish
between the consumer and commercial
classifications by delivery temperature.
(42 U.S.C. 6291(27)(A)) Therefore,
electric storage water heaters with input
rates at or below 12 kW are covered
consumer products (rather than
commercial equipment) regardless of
the delivered water temperature. Thus,
the product that AHRI discusses—
electric storage water heaters rated at or
below 12 kW but designed to deliver
water at temperatures above 180 °F—
would be classified as a consumer
product under EPCA and would not be
eligible for classification as a
residential-duty commercial water
heater under DOE’s definitions at 10
CFR 431.102. DOE is, therefore, not
proposing a conversion factor for
residential-duty commercial electric
storage water heaters, as there can be no
such equipment. As proposed in this
SNOPR, a product such as that
described by AHRI would rely on the
conversion that has been proposed for
electric storage water heaters generally.
Further, although electric storage water
heaters that are designed with input
ratings less than or equal to 12 kW and
to deliver water at temperatures of 180
°F were not included in the consumer
water heater energy factor test
procedure,6 they are consumer
products. As consumer products, such
water heaters are not required to be
tested under the metric for commercial
electric storage water heaters (i.e.,
standby loss). Rather, since such
products are classified as consumer
products under the statute, DOE
proposes to clarify that they should be
tested and rated under the UEF test
method. In the event that the UEF test
method does not apply, manufacturers
should submit a petition for waiver DOE
(see 10 CFR 430.27) that would allow
them to test and rate their products to
the appropriate consumer water heater
efficiency metrics. DOE is proposing in
a separate rulemaking to clarify the
definitions for specific kinds of
consumer water heaters by removing the
specifications related to the water
6 Prior to being updated by the July 11, 2014 final
rule (79 FR 40542, 40567), the Uniform Test
Method for Measuring the Energy Consumption of
Water Heaters at appendix E to subpart B of 10 CFR
430 included a definition for ‘‘Electric Storage-type
Water Heater’’ that included only, in relevant part,
models designed to heat and store water at a
thermostatically-controlled temperature of less than
180 °F.
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delivery temperature. 81 FR 28636.
Finally, DOE 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.
AHRI also commented that
residential-duty electric instantaneous
water heaters exist as defined in the
UEF test procedure and, therefore, need
a conversion. (AHRI, No. 13 at p. 6) DOE
agrees that residential-duty commercial
electric instantaneous water heaters
exist on the market and that they are
currently subject to the commercial
water heating equipment test
procedures. 10 CFR 431.106.
Commercial electric instantaneous
water heaters are also subject to the
energy conservation standards for
commercial instantaneous water heaters
established in EPCA. (42 U.S.C.
6313(a)(5)(D)–(E)).7 Specifically, for
commercial instantaneous water heaters
with a storage volume of less than 10
gallons, the minimum thermal
efficiency is 80 percent. For commercial
instantaneous water heaters with a
storage volume of 10 gallons or greater,
the minimum thermal efficiency is 77
percent, and the maximum standby loss
is 2.30 + (67/Measured Storage Volume
[in gallons]) percent per hour. Because
residential-duty electric instantaneous
commercial water heaters are required
to have a storage volume of 2 gallons or
less, the former standard level would
apply to this equipment. 10 CFR
431.102. Therefore, DOE has tentatively
decided to provide a mathematical
conversion factor for residential-duty
commercial electric instantaneous water
heaters. DOE also proposes energy
conservation standards for residentialduty commercial electric instantaneous
water heaters denominated in the UEF
metric. See section III.E.2.d for further
discussion of the mathematical
conversion for this equipment.
C. Approaches for Developing
Conversions
This section provides the approaches
that DOE is considering in developing
equations to convert from prior metrics
to the new metrics, including the
benefits and drawbacks of each
approach and details on how the
equations were derived.
To develop the conversions between
the prior metrics (first-hour rating,
7 In a NOPR for energy conservation standards for
commercial water heating equipment published on
May 31, 2016, DOE proposed to codify the energy
conservation standards in EPCA for commercial
electric instantaneous water heaters at 10 CFR
431.110. 81 FR 34440, 34535–36.
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1. Overview of Analytical Methods
Approach
The analytical methods approach
relies on basic equations of heat transfer
and thermodynamics, as well as
established understanding of the
behavior of water heaters, to estimate
the metric based on a set of known
parameters for the water heater,
environment, and test pattern. Such an
approach typically yields an equation or
set of equations that can be solved to
ultimately yield the metric of interest,
either an efficiency or delivery capacity.
An attempt is then made to manipulate
the equations for the metrics to yield an
equation that expresses the new metrics
in terms of the old metrics and other
known quantities. Analytical methods
have the advantage of capturing known
effects on performance without
conducting a series of experiments.
Additionally, a properly formulated
relationship would be expected to be
applicable to all water heaters on the
market. Analytical approaches do have
some drawbacks, however. Most
notably, these methods only account for
factors that are known to impact
performance and which can be readily
estimated. There may be other
phenomena that affect performance that
may not be included in the known
models. Second, application of these
models often require assumptions about
conditions. For example, one may need
to assume a particular temperature of
the water in the water heater despite the
fact that it is known that there is
variation in that temperature. Lastly,
while an analytical model reduces the
amount of tests needed to generate a
conversion equation, a thorough set of
experiments is still necessary to validate
the model. Because it is based on
fundamental physics, though, an
analytical model can typically be
extended with more confidence to a
water heater that has not been tested
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than would a model based purely on
experimental data.
Section III.C.4 discusses approaches
that DOE has considered for developing
analytical models to convert from prior
metrics to new metrics for both delivery
capacity and energy efficiency of water
heaters under the uniform energy factor
rating method.
2. Overview of Empirical Regression
Approach
The second category of conversion
factors considered by DOE is empirical
regression. In this approach, a collection
of water heaters is tested according to
both the former test procedure and the
new test procedure. The resultant
performance metrics, as well as other
data on the units (e.g., storage volume,
input rate), are compiled, and statistical
techniques are used to create
correlations that relate the new
performance metrics to the prior metrics
and characteristics. No consideration of
the underlying physics is used in this
approach. Rather, it is purely a datadriven method. The advantage of this
approach is that the results are not
biased by existing assumptions on how
a water heater should behave under
given conditions, with the results
representing exactly what is observed in
actual comparison testing. This
approach should capture all factors that
affect the energy efficiency and delivery
capacity, even though those factors may
not be known a priori.
Empirical regression also has some
drawbacks. One drawback is that the
resulting equations are most confidently
applied to water heaters with attributes
similar to those that were tested.
Consequently, to minimize
uncertainties, a large sample for testing
is often appropriate to capture more
fully many of the nuances in water
heater design. If extended to units not
sufficiently similar to those that were
tested, the equations may produce
unacceptably large differences between
predicted and measured values if a
feature on the untested model has an
effect that is not captured in the
experimental data. Another major
drawback is that empirical regression is
susceptible to experimental
uncertainties. While uncertainties can
be reduced through careful quality
checks of experimental data, uncertainty
is present in any test. The empirical
regressions, being based on many
samples across multiple different units,
will further reduce the uncertainty, but
some amount of uncertainty in the
regression may be unavoidable.
Section III.C.5 presents the details of
the empirical regression approaches
explored by DOE.
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3. Overview of Hybrid Approach
DOE has also considered a
combination of the analytical methods
approach and empirical regression
approach, termed a hybrid approach. In
this approach, a broad range of water
heaters are tested, as would be done in
using empirical regression. An
additional factor is added to the list of
attributes that is examined in the
regression; this factor uses the analytical
methods to first estimate the converted
value. This estimate of the revised
performance metric (maximum GPM,
first-hour rating, or UEF) for each water
heater tested is then used as an
independent variable in a regression to
determine the measured UEF. DOE
believes that this approach takes
advantage of the ability of the analytical
methods approach to capture the major
known factors that affect the efficiency,
yet adds the additional step of
regression to account for any influences
that are not well described by the
analytical methods.
4. Analytical Methods Approach
a. Maximum GPM
For flow-activated water heaters, the
delivery capacity under the EF and UEF
test procedures is determined by the 10minute maximum GPM rating test.
During this test, the water heater runs at
maximum firing rate to raise the
temperature from a starting value of
58 °F ± 2 °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.
In the April 14, 2015 NOPR, DOE
proposed to convert prior maximum
GPM represented values to those
represented values under the amended
test procedure by accounting only for
the change in Tdel from 135 °F to 125 °F
and for the change in the density and
specific heat of water at the new
delivery temperature. 80 FR 20116,
20125. The equation above can be
evaluated for both delivery
temperatures, and an expression for the
maximum GPM under the uniform
˙
efficiency descriptor (VUED) as a
function of the prior maximum GPM
˙
rating (Vex) was proposed as:
˙
˙
VUED = 1.147Vec
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maximum GPM, energy factor, thermal
efficiency, standby loss) and the new
metrics (first-hour rating, maximum
GPM, uniform energy factor), DOE has
broadly considered two different
approaches. The first, termed
‘‘analytical methods,’’ uses equations
based on the fundamental physics of
water heater operation to predict how
changes in test parameters lead to
changes in the performance metrics. The
second approach, termed ‘‘empirical
regression,’’ is a purely data-driven
approach that uses experimental data
and regressions to develop equations
that relate the prior metrics to the new
ones. In addition, DOE is also
considering a hybrid approach that uses
both techniques.
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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, Tdel is the delivered
water temperature, Tin is the inlet water
temperature, 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.
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˙
˙
VUED = 1.1461Vec
b. First-Hour Rating
In the April 14, 2015 NOPR, DOE
indicated that it was not aware of any
analytical models that would
mathematically represent the
conversion of first-hour ratings from the
prior test method to the amended test
method. 80 FR 20116, 20125. NEEA
questioned why DOE would make a
statement in this regard, but then go on
to propose a mathematical construct for
doing so. (NEEA, No. 15 at p. 5) DOE
notes that the mathematical construct
proposed to convert first-hour ratings is
based purely on regression analysis to
measured data and that DOE used the
terminology ‘‘analytical model’’ to
represent physics-based equations that
relate the two quantities. No comments
were received that proposed an
analytical model for converting firsthour ratings, so DOE continues to
propose to use data-driven regression
analysis to convert prior first-hour
ratings to amended first-hour ratings, as
discussed in section III.E.2.
c. Uniform Energy Factor
A number of changes to the 24-hour
simulated-use test will alter the
represented values of water heater
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 EF test or that
required during the UEF test):
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. 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),
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energy efficiency under the prior water
heater test procedures as compared to
the represented values 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 to the UEF,
which consists of an entirely new
approach for rating efficiency.
i. Consumer Storage Water Heaters
In the April 14, 2015 NOPR, DOE
proposed to use the Water Heater
Analysis Model (WHAM) as a basis for
conversion. 80 FR 20116, 20126–27.
This model first determines the amount
of energy input (Q) over a 24-hour
period using the following equation:
Tamb (67.5 °F), and V (varies depending
upon draw pattern).
DOE received a number of comments
with suggested improvements to the
WHAM model. Several commenters
addressed the assumption that the
average tank temperature, Ttank, is equal
to the average delivered water
temperature, Tdel. Rheem indicated that
the delivered hot water temperature is
greater than the average water
temperature in the tank due to
stratification and that the temperature
difference needs to be accounted for
more accurately in the analytical
equations. (Rheem, No. 11 at p. 6) AHRI
asked DOE to reconsider the assumption
that the delivered water temperature is
the same as the stored water
temperature. (AHRI, No. 13 at p. 7)
Bradford White added that the delivered
temperature is typically close to the
average tank temperature for electric
water heaters, but this assumption is
often not correct on gas-fired water
heaters that can have a stratified tank
with an average tank temperature that is
much lower than the delivered
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Northwest Energy Efficiency Alliance
(NEEA) commented that the relatively
simple physics associated with water
flow rate and temperature rise made this
conversion relatively robust, but that
some anomalies were present in
comparing measured and analytical
ratings. (NEEA, No. 15 at p. 6) As noted
in the data presented in the NOPR, DOE
found this conversion equation to match
well with measured data and is
proposing it in a slightly modified
version as the method to convert from
the prior maximum GPM rating to the
maximum GPM rating under the
uniform energy descriptor. In the NOPR,
the specific heat values were calculated
using the delivery temperatures of
125 °F and 135 °F for the EF and UEF
test procedures, respectively. In this
SNOPR, the specific heat values are
calculated using the average of the
delivery temperature (i.e., 125 °F and
135 °F for the EF and UEF test
procedures, respectively) and the inlet
temperature (i.e., 58 °F for both test
procedures). Further, the multiplier is
shown to the fourth decimal place to be
more consistent with the other
equations presented in this SNOPR.
Upon recalculation using appropriate
values of density and specific heat, the
proposed conversion equation is:
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temperature. (Bradford White, No. 14 at
p. 2) NEEA commented that DOE has
incorporated indefensible tank
temperature assumptions that are far
enough off to make the conversion
factors significantly inaccurate, and that
temperature differences between the top
and bottom of tall tanks can be up to
10 °F, leading to differences between
Tdel and Ttank of 5 °F. (NEEA, No. 15 at
p. 2)
To address these concerns, DOE
examined test data and assessed the
effect of changes in Ttank on the
predictions of the WHAM analytical
model. The average delivered water
temperature during draws was
compared to the average tank
temperature during standby periods for
a subset of the gas-fired and electric
storage water heaters tested. For
consumer electric storage water heaters,
the average delivered water temperature
was 6.8 °F higher than the mean tank
temperature, with a standard deviation
of 4.4 °F. For consumer gas-fired water
heaters, the delivered water temperature
was found to be only 1.5 °F greater than
the average tank temperature, with a
standard deviation of 4 °F. These results
raise questions about the statements by
commenters that the delivered water
temperature is always much greater than
the average tank temperature. DOE’s
observation in these tests is that on
occasion, the delivered temperature is
less than the average tank temperature
that was recorded during the standby
portion of the test. That observation is
inconsistent with the commenters’
suggestion, and DOE has identified
several potential reasonable
explanations for the observations. From
examination of test data, it appears that
there are several periods during the test
when a recovery occurs such that there
is an extended time following the
recovery before the start of the next
draw, meaning that the temperature of
the water in the tank has cooled from
the level it attains after a recovery.
Additionally, standby periods often
occur shortly after a tank recovery,
meaning that the average tank
temperature is relatively high during
those periods. These two characteristics
of the tests could certainly lead to
situations where the average delivered
water temperature is not always
significantly greater than the average
tank temperature during standby.
Next, DOE compared measured UEF
values to the predictions of the WHAM
model with different settings for Ttank.
As discussed further later in this
section, these WHAM predictions were
also computed with different
assumptions on the changes in recovery
efficiency and the UA values from the
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EF test to the UEF test. In all cases, an
assumption of Ttank = 125 °F resulted in
lower root-mean-square deviations
(RMSDs) between predicted and
measured values, suggesting that an
assumption of Ttank = 125 °F is
appropriate. DOE subsequently
computed WHAM predictions with Ttank
assumed down to 110 °F and found that
the assumption of Ttank = 125 °F held as
the best predictor of measured
performance.
In summary, DOE has found that a
disparity between Ttank and Tdel exists
but not to the extent that commenters
have stated. Further, using Ttank values
below 125 °F within the WHAM model
does not result in a better prediction of
performance. Therefore, DOE continues
to propose an assumed average tank
temperature of 125 °F in the WHAM
calculations that are part of the
conversion of EF to UEF.
Comments were received on DOE’s
assumption in the WHAM model that
the recovery efficiency and the UA
values do not change from the EF test
to the UEF test. Bradford White
disagreed with the belief that the UA
and recovery efficiency do not change
with the change in storing water at
135 °F versus delivering at 125 °F.
(Bradford White, No. 14 at p. 2) NEEA
commented that the recovery efficiency
of heat pump water heaters changes
dramatically with different stored water
temperature and disputed DOE’s
contention that a 7-percent change in
UA is immaterial to the WHAM
calculation. (NEEA, No. 15 at p. 3) DOE
notes that the WHAM model is not used
in the conversion that has been
proposed for heat pump water heaters
(rather DOE proposes the conversion
derived from empirical regression), so
NEEA’s comment regarding the
variation in recovery efficiency of heat
pump water heaters is not germane to
this issue. Lutz suggested a different
approach for determining the key
performance metrics when test
conditions change from an average
stored water temperature of 135 °F to an
average delivered water temperature of
125 °F. (Lutz, No. 16 at pp. 4–6) Lutz
recommends an approach whereby a
thermal standby loss and a conversion
efficiency are obtained from metrics
reported in the EF test, and that these
terms are used to estimate energy
consumption under the UEF test.
To evaluate these suggestions, DOE
first examined test data to estimate
changes in both UA and recovery
efficiency arising from changes in test
temperature. To remove any variability
in these metrics arising from changes in
the procedures used to compute them,
DOE focused on a subset of tests in
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59747
which the same draw pattern and
calculation procedure were used with
the thermostats set according to the EF
test procedure or the UEF test
procedure. By focusing on a comparison
of recovery efficiency and UA obtained
during those two tests, effects of the
calculation procedure are minimized to
allow the focus to be placed on changes
in tank temperature. It was found that
the UA of both gas-fired and electric
storage water heaters dropped an
average of 7 percent, with a standard
deviation of 3 percent. While it was
assumed that the recovery efficiency of
electric storage water heaters stays at
0.98, the recovery efficiency of gas-fired
storage water heaters was found to
increase 2 percent at a delivered
temperature of 125 °F compared to a
stored water temperature of 135 °F.
Given these values, DOE then explored
how changes in the UA value and
recovery efficiency affected overall
WHAM predictions of the UEF for all
water heaters tested. The UA was
reduced by 7 percent and the recovery
efficiency increased 2 percent from their
values determined in the EF test.
Combinations of the different settings of
UA, recovery efficiency, and Ttank were
used (a total of 8 in all), and RMSDs
were computed. The RMSD was lowest
under the assumption that the UA and
recovery efficiency were the same from
the EF test to the UEF test. This finding
held when all water heaters were
grouped together, as well as when they
were separated by fuel type (i.e., electric
and gas). While limited testing indicated
that reducing the set point temperature
changed the recovery efficiency and UA
values, when applied to the entire
dataset, the model produced predictions
with lower RMSDs under the
assumption of no change in recovery
efficiency or UA values.
DOE also compared predictions from
procedures described by Lutz to the
measured data. DOE found that the
RMSD when comparing all water
heaters was essentially the same as for
the WHAM model, with the RMSD of
the Lutz approach being slightly lower
for electric water heaters and slightly
higher for gas-fired water heaters.
In summary, DOE found that the
WHAM model provided more accurate
predictions of actual performance when
Ttank is assumed to be 125 °F and the
values for UA and recovery efficiency
are assumed identical under both the EF
and UEF test procedures. Further, when
comparing the WHAM and Lutz
methods, the RMSDs were found to be
essentially the same. Therefore, DOE
proposes to use as the basis of its
conversion factors for consumer storage
water heaters the WHAM model with an
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assumed Ttank = 125 °F and an
assumption that the recovery efficiency
and UA values are identical under the
UEF test, as they are under the EF test.
Rheem commented that the method of
deriving the coefficients presented in
the NOPR to determine the WHAM
predictions was not clear, and AHRI
stated that more information was
needed on these coefficients. (Rheem,
No. 11 at p. 6; AHRI, No. 13 at p. 5) In
this SNOPR, DOE is presenting more
details on the derivation of the
equations it is proposing for converting
from prior metrics to the UEF.
Additionally, the coefficients are
modified from the version provided in
the NOPR on account of different
algebraic approaches. In the equations
below, variables with a subscript ‘‘N’’
refer to the UEF test procedure.
Variables with a subscript ‘‘C’’ refer to
the EF test procedure.
The first step is to express the UEF in
terms of the delivered thermal energy
and the energy consumed:
where:
A = rNCp,NVN(Tdel,N¥Tin)
B = Ttank,N¥Tamb
delivered for the particular simulated
use profile implemented during the UEF
test.
The UEF equation can be rearranged
to yield the following form:
The input power is given by the
variable P. In this equation, UA is
unknown, so it must be determined
from the EF test. The WHAM equation
for the energy consumed during the EF
test, QC, is:
E = (Ttank,c¥Tamb)
With Qc = D/EF, the equation above
for UA can be rewritten as:
It is assumed that the recovery
efficiency and UA values are the same
for both tests. The density, r, is
evaluated at the delivery temperature,
Tdel, and the specific heat, Cp, is
evaluated at the average of Tdel and the
inlet temperature, Tin. V is the volume
Where:
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D = rcCp,cVc(Tdel,c¥Tin)
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59749
The values for these coefficients a, b,
c, and d are presented in Table III.3.
TABLE III.3—COEFFICIENTS FOR THE PROPOSED ANALYTICAL UEF CONVERSION FACTOR FOR CONSUMER STORAGE
WATER HEATERS
Draw pattern
a
Very Small .......................................................................................................
Low ..................................................................................................................
Medium ............................................................................................................
High ..................................................................................................................
b
0.250266
0.065860
0.045503
0.029794
c
57.5
57.5
57.5
57.5
0.039864
0.039864
0.039864
0.039864
d
67.5
67.5
67.5
67.5
In the April 2015 NOPR, DOE
indicated that N* is the total number of
draws during the test scaled with
respect to the standby time occurring
after the draw is completed. 80 FR
20116, 20127 (April 14, 2015). Those
draws that are followed by less than one
hour contribute a fractional value to N*
that is equal to the standby time in
minutes following the draw divided by
60 minutes, while the draws that are
followed by one hour or more contribute
a value of one to N*. To determine the
loss factor (LF) from the equation above,
data are obtained from the EF test, but,
as AHRI notes, the N* depends upon the
length of those six draws in the test.
Those draws are of different length,
with the first three occurring at
maximum flow rate and the final three
occurring at minimum flow rate.
Therefore, the value of N* will not be
constant for all water heaters. Instead,
DOE computed a separate value of N*
for each test based upon reported data
on the flow rates of each draw. From
these flow rates, an estimate of the
length of each draw was obtained, and
the standby time before the next draw
could be computed. Given this adjusted
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analytical model for consumer
instantaneous water heaters accordingly
to account for this change.
The loss factor represents the amount
of energy stored in the materials making
up the instantaneous water heater. Its
value was obtained in the NOPR by
examining test data and applying the
following equation for each test:
EP30AU16.028</GPH>
Regarding the analytical method to
convert prior represented values for
consumer instantaneous water heaters
to UEF, NEEA argued that technology
differences can cause complications
with analytical methods but did not
suggest any particular improvements to
the methods proposed by DOE. (NEEA,
No. 15 at p. 6) AHRI stated that the
determination of N*, which is the
number of draws from which heat loss
occurs to the environment, does not
factor in the low-fire testing per the EF
test procedure nor the changes in the
flow rate used for the test. (AHRI, No.
8 at p. 3) DOE agrees with AHRI’s
observation, and is modifying its
ii. Consumer Instantaneous Water
Heater
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Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
technique, along with additional test
data collected since the NOPR, DOE
computed new loss factors. It found that
loss factors were different for electric
instantaneous water heaters than for
gas-fired instantaneous water heaters, so
it is using different analytical equations
for gas-fired and electric models. The
loss factor, LF, being used is 0.592 Btu/
°F for gas-fired instantaneous water
heaters, and LF for electric
instantaneous water heaters is 0.084
Btu/°F.
The loss factor, N* for the new draw
patterns of the UEF test, and the test
conditions imposed in the UEF test are
used with the equation above to
estimate the energy consumed for a
particular draw pattern for either
electric or gas-fired units. The UEF can
be determined as:
The energy delivered as hot water,
Qdel (= rcpV(Tdel¥Tin)), and N* depend
upon the draw pattern. The delivered
temperature is assumed to be 125 °F,
and the ambient temperature is assumed
to be 67.5 °F. This equation can be
rearranged by multiplying the
numerator and denominator by hr/Qdel,
resulting in an equation of the form:
Density, r, is computed at the
delivery temperature of 125 °F, and cp is
computed at the average of the delivery
temperature and the inlet temperature,
or 91.5 °F. The values for N* and A are
provided in Table III.4.
TABLE III.4—N* AND COEFFICIENTS FOR THE PROPOSED ANALYTICAL UEF CONVERSION FACTOR FOR CONSUMER
INSTANTANEOUS WATER HEATERS
A
N*
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Very Small ...................................................................................................................................
Low ..............................................................................................................................................
Medium ........................................................................................................................................
High ..............................................................................................................................................
iii. Residential-Duty Commercial
Storage Water Heaters
Regarding the analytical method to
convert standby loss and thermal
efficiency metrics for residential-duty
commercial water heaters to UEF, DOE
received comments from Rheem, AHRI,
and NEEA. NEEA stated that there is
poor agreement between predictions
and measured values and indicated that
there must be some missing variables or
factors, but NEEA also commented that
it is not clear what those factors might
be. (NEEA, No. 15 at p. 6) Rheem argued
that DOE needs to replace the ‘‘24’’
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multiplier with the difference between
24 and the burner on-time in the 24hour testing period to account for the
actual time of heat loss during the test.
(Rheem, No. 11 at p. 6) AHRI
commented that UA losses only occur
when the burner is not firing, so the 24
hours should be reduced by the total
burner on time over the simulated day.
(AHRI, No. 13 at p. 7)
In response to NEEA’s comment, DOE
has evaluated the factors included in the
analytical model and has not identified
other terms that would increase the
accuracy of the predictions. In any case,
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4.36
6.72
7.45
7.53
0.003819
0.001549
0.001186
0.000785
Gas
0.026915
0.010917
0.008362
0.005534
to the extent unknown factors are
important, the use of regressions on top
of the analytical approach should
account for such factors.
DOE agrees with the comments from
Rheem and AHRI and is modifying the
analytical equation used to predict UEF
for residential-duty water heaters to
adjust the time of application of standby
losses. The new equation proposed for
estimating the energy consumption of a
residential-duty commercial water
heater as a function of standby loss, SL,
thermal efficiency, Et, and input power,
P, is:
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Draw pattern
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This equation mirrors the WHAM
equation, with the second term in the
square brackets removing addition of
standby loss while the burner is
operating. This step avoids double
counting standby loss, as it is already
Where A = rcpV(Tdel¥Tin) and F =
(Ttank¥Tamb)/70.
59751
incorporated in the thermal efficiency
metric while the burner is operating.
The equation can be rewritten as:
The UEF can be determined as Qdel/
Q = A/Q. Substituting the equation for
Q into this ratio yields:
Further rearranging yields the
following expression for UEF:
Where
G = 24/A. Values for the coefficients F and
G are presented in Table III.5.
TABLE III.5—COEFFICIENTS FOR THE PROPOSED ANALYTICAL UEF CONVERSION FACTOR FOR THE RESIDENTIAL-DUTY
COMMERCIAL STORAGE WATER HEATERS
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5. Empirical Regression Approach
As noted, the empirical regression
approach does not necessarily assume
any prior knowledge of water heater
performance, so DOE sought an
approach that would allow it to
consider many factors as part of its
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regression equations, but would
systematically eliminate any that were
not shown to have a substantive impact
on the resulting performance metrics.
DOE selected a step regression method
to accomplish this goal. The step
regression method examines a series of
linear equations that relate the new
delivery capacity and UEF to a set of
observed independent variables, such as
storage volume, input rate, EF test
procedure delivery capacity, recovery
efficiency, energy factor, thermal
efficiency, or standby loss. 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
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For the UEF conversion, DOE
tentatively concluded that given the
similarities between consumer electric
instantaneous water heaters and
residential-duty commercial electric
instantaneous water heaters, the
principles used to derive the consumer
electric instantaneous analytical
conversion apply to the residential-duty
commercial equipment class as well.
Therefore, DOE is proposing to use the
consumer electric instantaneous
mathematical conversion as a starting
point for developing the residentialduty electric instantaneous conversion,
with the assumption that thermal
efficiency is approximately equal to
recovery efficiency. Using this
assumption, DOE modified the
consumer electric instantaneous
analytical equation to the form found
below, where Et is thermal efficiency
and A is coefficient found in Table III.4.
DOE proposes to use this equation as
the mathematical conversion factor for
residential-duty commercial electric
instantaneous water heaters.
0.0043520
0.0011450
0.0007914
0.0005181
EP30AU16.035</GPH>
iv. Residential-Duty Commercial
Electric Instantaneous Water Heaters
0.821429
0.821429
0.821429
0.821429
EP30AU16.034</GPH>
Very Small ...............................................................................................................................................................
Low ..........................................................................................................................................................................
Medium ....................................................................................................................................................................
High ..........................................................................................................................................................................
G
EP30AU16.033</GPH>
F
EP30AU16.032</GPH>
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equation with the best fit to the actual
data is chosen.
This approach eliminates factors that
are not significant in converting from
the EF, TE, and SL metrics to the UEF
metrics, but could yield a ‘‘best’’ fit that
might be more complicated than a
simpler equation with a marginally
worse level of match to experimental
data. In addition to making the
conversion equations more prone to
error in implementation, a complicated
equation may also include factors that
would not be applicable to the entire
population of water heaters. DOE,
therefore, 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 differences between
measured values and predicted values
from the correction equations. When
those differences were comparable for
two different models, DOE opted for the
simpler of the two, so long as it
captured what would be expected to be
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.
In the April 2015 NOPR, DOE noted
that it was not aware of an analytical
method for determining the first-hour
rating, and proposed to use an empirical
regression methodology which DOE
believed would be more accurate than
attempting to develop an analytical
method. 80 FR 20116, 20125–28 (April
14, 2015). As noted previously in
section III.C.2, DOE did not receive any
comments suggesting an alternate
methodology for determining first-hour
rating, and, thus, DOE is proposing
conversion factors for those metrics and
product types based on the use of the
empirical regression methodology. In
addition, for heat pump water heaters,
DOE found that the conversion
equations resulting from the analytical
method and hybrid regressed-analytical
approach had higher RMSD values than
those resulting from the empirical
regression approach (see section
III.E.2.a.ii). Therefore, as proposed in
the April 2015 NOPR, DOE is proposing
a mathematical conversion for heat
pump water heaters based on the
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empirical regression approach. Id. at
20132. (However, as discussed in
section III.E.2.a.ii, this approach was
modified based on comments received
from interested parties.)
D. Testing Conducted for the
Mathematical Conversion
This section provides an overview of
the consumer and residential-duty
commercial water heater markets and
the test data that were available to DOE
when developing the NOPR and SNOPR
conversion factors.
As discussed in the April 2015 NOPR,
many stakeholders commented on the
importance of using actual test data in
the derivation of the mathematical
conversion factor. 80 FR 20116, 20121
(April 14, 2015). DOE used actual test
data as part of the basis for the
conversion factors and to validate the
results. The models selected for testing
in the April 2015 NOPR were chosen
based on their characteristics being
generally reflective of the broader
market. In response to the April 2015
NOPR, DOE received comments
suggesting areas of the market that were
not adequately tested. These comments,
along with DOE’s responses, are
discussed in detail later in this section.
For consumer and residential-duty
commercial water heaters, DOE used the
Compliance Certification Management
System (CCMS) and crosschecked it
with the AHRI directory 8 to determine
the characteristics of models available
on the market. DOE conducted
additional research into manufacturers’
literature to identify characteristics
related to the water heater performance,
such as the input capacity (for models
not listed in the AHRI directory),
venting options, tank configuration
(short or tall), NOX emissions level,
ignition type (standing or non-standing
pilot), and whether the model is
certified for use in mobile homes. DOE
also used the first-hour ratings based on
the EF test procedure to attempt to
predict the draw pattern that would
result from the UEF test, and considered
the probable draw pattern when
selecting models for testing.9 However,
8 The numbers presented in the following tables
are from the CCMS directory as of September 2015
and the AHRI directory as of July 2015.
9 As compared to the EF test procedure that relies
on a single draw pattern, the UEF test procedure
employs one of four patterns, the choice of which
is determined based on the result of the first-hour
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upon testing the models according to
the UEF test method, the predicted draw
pattern bin and the actual draw pattern
bin did not always match up, and
therefore, the actual number of models
tested to each draw pattern was
different than originally predicted. DOE
attempted to test water heaters
representative of the categories listed
above, from various manufacturers, and
to a similar percentage of the market
across these categories (e.g., DOE
attempted to test approximately 8
percent of both the short and tall water
heater markets, resulting in more tall
units being tested due to the tall market
being larger). Table III.6 shows the
consumer water heater market
distribution by product class, and by
various attributes that commenters
suggested DOE should examine. Table
III.6 also shows the predicted and actual
number of tested water heaters, where
the predicted draw pattern of the model
selected may have differed from the
actual draw pattern that was used once
testing was performed. Table III.7
through Table III.12 show the consumer
market distribution by rated storage
volume and input rate for various water
heater types, along with the number of
units tested for the April 2015 NOPR in
each category. Table III.13 shows the
market distribution for consumer heat
pump water heaters by rated storage
volume and EF, along with the number
of units tested for the April 2015 NOPR
in each category. Table III.14 and Table
III.15 show the residential-duty
commercial water heater market
distribution by input rate and rated
storage volume and the number of units
tested for the April 2015 NOPR for gasfired and oil-fired water heaters,
respectively. The numbers provided
below for the market and test
distribution are for unique basic models,
as opposed to individual model
numbers, due to the addition of AHRI
aggregated test data discussed further in
this section. As discussed in detail
immediately below, the following tables
show the number of models tested for
the NOPR. After the NOPR tables, are
tables containing the additional number
of models that DOE used for this
SNOPR.
rating test (for storage water heaters) or the
maximum GPM rating test (for instantaneous water
heaters).
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TABLE III.6—CONSUMER WATER HEATER TEST DATA USED IN THE NOPR AND MARKET DISTRIBUTION BY PRODUCT TYPE
AND WATER HEATER ATTRIBUTE *
Water heater type **
G–S
Total Units ................................................
Venting Options:
Atmospheric ......................................
Power ................................................
Short or Tall:
Short .................................................
Tall ....................................................
NOX Emissions:
Standard ...........................................
Low ...................................................
Ultra-Low ...........................................
Ignition:
Standing Pilot ....................................
No Standing Pilot ..............................
Mobile Home Certified:
No .....................................................
Yes ....................................................
Draw Pattern: †††
Very Small ........................................
Low ...................................................
Medium .............................................
High ...................................................
O–S †
E–S ††
HP–S
T–S
G–I
E–I
21/340
2/7
9/105
5/26
2/5
17/139
5/67
14/240
7/99
0/7
—
—
—
—
—
—
—
—
17/139
—
—
7/94
14/188
—
2/7
2/39
7/42
—
—
—
—
—
—
—
—
2/70
16/199
3/71
—
—
—
—
—
—
—
—
—
—
—
—
—
6/33
11/103
—
—
—
11/239
10/100
—
2/7
—
—
—
—
—
—
—
12/103
—
—
21/326
0/14
2/7
—
9/99
0/6
5/26
—
2/5
—
16/138
1/1
5/67
—
—
1/0/7
10/8/161
10/13/172
—
—
—
1/2/7
—
1/3/46
7/6/54
0/0/5
—
0/1/1
2/3/13
1/1/12
—
2/2/4
0/0/1
—
—
1/2/2
7/8/56
7/7/81
5/5/67
—
—
—
* The information in this table is presented as the actual number of tested units/the number of models available on the market. In the draw pattern rows, the first number is the number of tested units that DOE predicted would be in each draw pattern when that unit was selected based on
the unit’s EF test procedure delivery capacity; the second number is the actual number of tested units in each draw pattern; and the third number
is the number of models available on the market. A ‘‘—’’ indicates that there are no models available in the category, and, thus, there were no
units tested.
** Each water heater type is abbreviated using a two part designation: For the first letter(s), ‘‘G’’ means gas-fired, ‘‘O’’ means oil-fired, ‘‘E’’
means electric, ‘‘HP’’ means heat pump, and ‘‘T’’ means tabletop, and for the second letter ‘‘S’’ means storage and ‘‘I’’ means instantaneous.
† Two oil-fired storage water heaters were tested, but only one is compliant with the current energy conservation standards.
†† This category includes only electric storage water heaters that use electric resistance elements, and does not include electric heat pump
water heaters.
††† First-hour ratings from the EF test procedure were used to estimate draw patterns.
TABLE III.7—CONSUMER GAS-FIRED STORAGE TEST DATA USED IN THE NOPR AND MARKET DISTRIBUTION BY INPUT
RATE AND RATED STORAGE VOLUME *
Rated storage volume
(gallons)
Input rate
(kBtu/h)
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20
30 .............
32 .............
33 .............
34 .............
35 .............
35.5 ..........
36 .............
37 .............
38 .............
40 .............
42 .............
45 .............
47 .............
48 .............
50 .............
55 .............
56 .............
58 .............
60 .............
62 .............
65 .............
75 .............
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0/1 (0%)
28
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
29
30
—
1/4 (25%)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1/1 (100%)
—
—
—
0/9 (0%)
0/4 (0%)
0/1 (0%)
—
0/12 (0%)
0/6 (0%)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
38
40
—
—
—
—
—
—
0/1 (0%)
—
0/1 (0%)
0/3 (0%)
—
—
—
—
—
—
—
—
—
—
—
—
0/4 (0%)
0/3 (0%)
—
0/7 (0%)
0/1 (0%)
0/2 (0%)
1/10 (10%)
0/1 (0%)
1/17 (6%)
9/85 (11%)
0/5 (0%)
—
—
—
0/2 (0%)
—
—
—
—
—
—
—
48
—
—
—
—
—
—
—
—
0/1 (0%)
1/4 (25%)
—
0/1 (0%)
—
0/1 (0%)
0/1 (0%)
0/1 (0%)
0/2 (0%)
—
0/5 (0%)
—
0/5 (0%)
—
50
—
—
—
—
—
—
1/11 (9%)
—
0/9 (0%)
1/71 (1%)
0/8 (0%)
1/3 (33%)
1/3 (33%)
—
1/8 (13%)
—
—
0/1 (0%)
0/9 (0%)
0/6 (0%)
1/3 (33%)
—
55
—
—
—
—
—
—
—
—
—
—
—
0/2 (0%)
—
—
0/2 (0%)
—
—
—
0/2 (0%)
—
—
—
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category,
and, thus, there were no units tested.
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TABLE III.8—CONSUMER ELECTRIC
STORAGE TEST DATA USED IN THE
NOPR AND MARKET DISTRIBUTION
BY INPUT RATE AND RATED STORAGE VOLUME *
Rated storage volume
(gallons)
28
30
36
38
40
47
50
52
55
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
TABLE III.9—CONSUMER GAS-FIRED
INSTANTANEOUS TEST DATA USED
IN THE NOPR AND MARKET DISTRIBUTION BY INPUT RATE AND
RATED STORAGE VOLUME *—Continued
All input rates
0/6 (0%)
1/27 (4%)
0/1 (0%)
0/6 (0%)
4/29 (14%)
0/2 (0%)
3/26 (12%)
0/2 (0%)
1/6 (17%)
* The information in this table is presented
as the number of tested units/the number of
models available on the market. The percentage of models tested is in parentheses next to
the counts of units tested and models.
Input rate
(kBtu/h)
120
130
140
145
150
152
157
160
175
180
........................................
........................................
........................................
........................................
........................................
........................................
........................................
........................................
........................................
........................................
All rated
storage
volumes
Input rate
(kBtu/h)
190 ........................................
192 ........................................
195 ........................................
199 ........................................
199.9 .....................................
200 ........................................
7.5 .........................................
8 ............................................
8.3 .........................................
9 ............................................
9.5 .........................................
10 ..........................................
11 ..........................................
11.5 .......................................
12 ..........................................
2.4 .........................................
3 ............................................
3.4 .........................................
3.5 .........................................
4.1 .........................................
4.8 .........................................
5.5 .........................................
6 ............................................
6.5 .........................................
7.2 .........................................
1/2 (50%)
0/6 (0%)
0/1 (0%)
0/9 (0%)
0/3 (0%)
0/5 (0%)
0/2 (0%)
1/4 (25%)
0/5 (0%)
0/1 (0%)
0/3 (0%)
1/3 (33%)
0/3 (0%)
0/3 (0%)
1/6 (17%)
1/4 (25%)
0/2 (0%)
0/3 (0%)
0/2 (0%)
* The information in this table is presented
as the number of tested units/the number of
models available on the market. The percentage of models tested is in parentheses next to
the counts of units tested and models.
TABLE III.11—CONSUMER TABLETOP
STORAGE TEST DATA USED IN THE
NOPR AND MARKET DISTRIBUTION
BY INPUT RATE AND RATED STORAGE VOLUME *
All rated
storage
volumes
Input rate (kW)
1/11 (9%)
0/2 (0%)
2/9 (22%)
0/1 (0%)
1/13 (8%)
1/1 (100%)
0/7 (0%)
0/6 (0%)
1/2 (50%)
3/30 (10%)
1/9 (11%)
0/1 (0%)
0/1 (0%)
1/27 (4%)
2/6 (33%)
2/13 (15%)
TABLE III.10—CONSUMER ELECTRIC
INSTANTANEOUS TEST DATA USED
FOR THE NOPR AND MARKET DISTRIBUTION BY INPUT RATE AND
RATED STORAGE VOLUME *
All rated
storage
volumes
All rated
storage
volumes
Input rate (kW)
* The information in this table is presented
as the number of tested units/the number of
models available on the market. The percentage of models tested is in parentheses next to
the counts of units tested and models.
TABLE III.9—CONSUMER GAS-FIRED
INSTANTANEOUS TEST DATA USED
IN THE NOPR AND MARKET DISTRIBUTION BY INPUT RATE AND
RATED STORAGE VOLUME *
TABLE III.10—CONSUMER ELECTRIC
INSTANTANEOUS TEST DATA USED
FOR THE NOPR AND MARKET DISTRIBUTION BY INPUT RATE AND
RATED STORAGE VOLUME *—Continued
Rated storage volume
(gallons)
All input rates
27 ..........................................
38 ..........................................
40 ..........................................
1/2 (50%)
1/1 (100%)
0/2 (0%)
* The information in this table is presented
as the number of tested units/the number of
models available on the market. The percentage of models tested is in parentheses next to
the counts of units tested and models.
TABLE III.12—CONSUMER OIL-FIRED STORAGE TEST DATA USED IN THE NOPR AND MARKET DISTRIBUTION BY INPUT
RATE AND RATED STORAGE VOLUME *
Rated storage volume
(gallons)
Input rate (kBtu/h)
30
90 .................................................................................................................................................
104 ...............................................................................................................................................
105 ...............................................................................................................................................
32
—
—
0/2 (0%)
50
0/2 (0%)
1/2 (50%)
—
—
—
0/1 (0%)
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and models.
mstockstill on DSK3G9T082PROD with PROPOSALS2
TABLE III.13—CONSUMER HEAT PUMP DISTRIBUTION USED FOR THE NOPR BY ENERGY FACTOR AND RATED STORAGE
VOLUME *
Rated storage volume
(gallons)
Energy factor
45
2.2 ....................................
2.21 ..................................
2.31 ..................................
2.32 ..................................
2.33 ..................................
2.4 ....................................
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50
—
—
—
—
—
—
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58
1/1 (100%)
—
—
0/1 (0%)
—
0/1 (0%)
PO 00000
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65
—
—
—
—
—
—
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66
—
—
0/1 (0%)
—
—
—
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72
—
—
—
—
—
—
E:\FR\FM\30AUP2.SGM
80
—
—
—
—
—
—
30AUP2
—
—
0/1 (0%)
—
1/1 (100%)
—
119
—
0/1 (0%)
—
—
—
—
59755
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.13—CONSUMER HEAT PUMP DISTRIBUTION USED FOR THE NOPR BY ENERGY FACTOR AND RATED STORAGE
VOLUME *—Continued
Rated storage volume
(gallons)
Energy factor
45
2.45 ..................................
2.5 ....................................
2.72 ..................................
2.74 ..................................
2.75 ..................................
2.9 ....................................
3.05 ..................................
3.07 ..................................
3.1 ....................................
3.17 ..................................
3.24 ..................................
3.39 ..................................
50
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
58
1/2 (50%)
—
—
—
0/1 (0%)
0/1 (0%)
—
—
0/1 (0%)
—
0/1 (0%)
—
65
66
—
—
—
—
—
—
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
72
—
0/1 (0%)
—
0/1 (0%)
—
—
—
—
—
0/1 (0%)
—
—
80
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
119
0/1 (0%)
0/1 (0%)
0/1 (0%)
—
—
0/1 (0%)
—
0/1 (0%)
0/1 (0%)
—
—
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
—
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category,
and, thus, there were no units tested.
TABLE III.14—RESIDENTIAL-DUTY COMMERCIAL GAS-FIRED STORAGE TEST DATA USED IN THE NOPR AND MARKET
DISTRIBUTION BY INPUT RATE AND RATED STORAGE VOLUME *,**
Input
rate
(kBtu/h)
Rated storage volume
(gallons)
34
40
50
55
60
74
75
75 .........
75.1 ......
76 .........
—
—
—
—
—
—
—
—
2/4 (50%)
—
—
—
—
—
0/2 (0%)
—
0/3 (0%)
—
78 .........
80 .........
—
—
—
—
—
—
0/1 (0%)
0/2 (0%)
—
—
85 .........
88 .........
90 .........
91.3 ......
98 .........
100 .......
—
—
—
—
—
0/1 (0%)
—
—
—
0/1 (0%)
—
—
—
—
—
—
0/2 (0%)
0/1 (0%)
—
—
—
—
—
0/3 (0%)
—
—
—
—
—
—
80
98
100
119
—
—
0/2 (0%)
—
0/2 (0%)
—
—
0/1 (0%)
0/3 (0%)
—
—
—
—
0/1 (0%)
0/1 (0%)
0/3 (0%)
2/21
(10%)
—
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0/2 (0%)
—
—
—
—
—
0/2 (0%)
—
—
0/1 (0%)
—
—
—
—
1/1
(100%)
0/3 (0%)
0/3 (0%)
—
—
—
—
—
—
—
—
—
0/2 (0%)
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category,
and, thus, there were no units tested.
** Seven data points were presented in the April 2015 NOPR, but two units were of the same basic model, and three units were tested to the
incorrect input rate. DOE has removed these data points from the analysis.
TABLE III.15—RESIDENTIAL-DUTY COMMERCIAL OIL-FIRED STORAGE TEST DATA USED IN THE NOPR AND MARKET
DISTRIBUTION BY INPUT RATE AND RATED STORAGE VOLUME *,**
Rated storage volume
(gallons)
Input rate (kBtu/h)
30
119 ...............................................................................................................................................
140 ...............................................................................................................................................
50
70
0/2 (0%)
—
0/1 (0%)
0/1 (0%)
0/1 (0%)
—
mstockstill on DSK3G9T082PROD with PROPOSALS2
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category,
and, thus, there were no units tested.
In addition, AHRI submitted test
results for testing conducted under both
the EF and UEF test methods by its
member manufacturers. (AHRI, No. 9)
As using additional data points will
generally reduce the uncertainty in the
statistical modeling used to generate the
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21:44 Aug 29, 2016
Jkt 238001
conversion factor, DOE has incorporated
the test data submitted by AHRI in its
analysis for this SNOPR. DOE also
conducted additional testing, which was
completed after the publication of the
April 2015 NOPR, and is including the
results in this SNOPR. Table III.16
PO 00000
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Sfmt 4702
shows the consumer market distribution
by product class and attributes that
commenters suggested DOE examine,
along with the number of units tested
for the development of this SNOPR in
each category. Table III.17 through
Table III.21 show the consumer market
E:\FR\FM\30AUP2.SGM
30AUP2
59756
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
distribution by rated storage volume and
input rate for various water heater
categories and the number of units
tested for this SNOPR in each category.
Table III.22 shows the consumer heat
pump market distribution by rated
storage volume and EF and the number
of units tested for this SNOPR in each
category. Table III.23 and Table III.24
show the residential-duty commercial
market distribution by input rate and
rated storage volume and the number of
units tested for this SNOPR in each
category. AHRI did not supply model
numbers in its data, so some
percentages in the tables below are
greater than 100 percent, suggesting that
DOE and AHRI have data on the same
water heaters. Both the DOE and AHRI
data sets contain some test points that
are from different water heaters of the
same model. These models were only
counted once in the tables below, and
the test data were averaged into a single
data point in the conversion factor
derivation.
TABLE III.16—CONSUMER MARKET DISTRIBUTION AND TEST DATA USED FOR THIS SNOPR BY PRODUCT TYPE AND
WATER HEATER ATTRIBUTE*
Water heater type **
G–S
Total Units ................................................
Venting Options
Atmospheric ......................................
Power ................................................
Short or Tall
Short .................................................
Tall ....................................................
NOX Emissions
Standard ...........................................
Low ...................................................
Ultra-Low ...........................................
Ignition
Standing Pilot ....................................
No Standing Pilot ..............................
Mobile Home Certified
No .....................................................
Yes ....................................................
Draw Pattern †††
Very Small ........................................
Low ...................................................
Medium .............................................
High ...................................................
O–S †
E–S ††
HP–S
T–S
G–I
E–I
118/340
2/7
46/105
16/26
3/5
53/139
5/67
84/240
33/99
0/7
—
—
—
—
—
—
—
—
53/139
—
—
42/94
75/188
—
2/7
11/39
19/42
—
—
—
—
—
—
—
—
13/70
81/199
24/71
—
—
—
—
—
—
—
—
—
—
—
—
—
9/33
44/103
—
—
—
76/239
41/100
—
2/7
—
—
—
—
—
—
—
48/103
—
118/326
0/14
2/7
—
46/99
0/6
16/26
—
3/5
—
52/138
1/1
5/67
—
—
4/2/7
55/55/161
59/61/172
—
—
—
1/2/7
—
12/13/46
31/32/54
4/1/5
—
0/1/1
7/9/13
6/6/12
—
3/2/4
0/1/1
—
—
1/2/2
13/21/56
18/30/81
5/5/67
—
—
—
* The information in this table is presented as the actual number of tested units/the number of models available on the market. In the draw pattern rows, the first number is the number of tested units that DOE predicted would be in each draw pattern when that unit was selected based on
the unit’s EF test procedure delivery capacity; the second number is the actual number of tested units in each draw pattern; and the third number
is the number of models available on the market. A ‘‘—’’ indicates that there are no models available in the category, and, thus, there were no
units tested.
** Each water heater type is abbreviated using a two part designation: For the first letter(s) ‘‘G’’ means gas-fired, ‘‘O’’ means oil-fired, ‘‘E’’
means electric, ‘‘HP’’ means heat pump, and ‘‘T’’ means tabletop, and for the second letter ‘‘S’’ means storage and ‘‘I’’ means instantaneous.
† Two oil-fired storage water heaters were tested, but only one is compliant with the current energy conservation standards.
†† In this table, this category includes only electric storage water heaters that use electric resistance elements, and does not include electric
heat pump water heaters.
†† First-hour ratings from the EF test procedure were used to estimate draw patterns.
TABLE III.17—CONSUMER GAS-FIRED STORAGE DISTRIBUTION AND TEST DATA USED FOR THIS SNOPR BY INPUT RATE
AND RATED STORAGE VOLUME *
Rated storage volume
(gallons)
Input rate
(kBtu/h)
mstockstill on DSK3G9T082PROD with PROPOSALS2
20
30 .............
32 .............
33 .............
34 .............
35 .............
35.5 ..........
36 .............
37 .............
38 .............
40 .............
42 .............
45 .............
47 .............
48 .............
50 .............
55 .............
56 .............
58 .............
VerDate Sep<11>2014
28
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1/1 (100%)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
21:44 Aug 29, 2016
Jkt 238001
29
30
—
2/4 (50%)
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
PO 00000
6/9 (67%)
3/4 (75%)
1/1 (100%)
—
0/12 (0%)
2/6 (33%)
—
—
—
—
—
—
—
—
—
—
—
—
Frm 00022
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38
40
—
—
—
—
—
—
1/1 (100%)
—
0/1 (0%)
1/3 (33%)
—
—
—
—
—
—
—
—
Sfmt 4702
1/4 (25%)
0/3 (0%)
—
3/7 (43%)
0/1 (0%)
0/2 (0%)
4/10 (40%)
0/1 (0%)
8/17 (47%)
29/85 (34%)
0/5 (0%)
—
—
—
0/2 (0%)
—
—
—
E:\FR\FM\30AUP2.SGM
48
—
—
—
—
—
—
—
—
0/1 (0%)
3/4 (75%)
—
0/1 (0%)
—
0/1 (0%)
1/1 (100%)
0/1 (0%)
0/2 (0%)
—
30AUP2
50
—
—
—
—
—
—
3/11 (27%)
—
5/9 (56%)
24/71 (34%)
3/8 (38%)
2/3 (67%)
1/3 (33%)
—
3/8 (38%)
—
—
0/1 (0%)
55
—
—
—
—
—
—
—
—
—
—
—
1/2 (50%)
—
—
1/2 (50%)
—
—
—
59757
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.17—CONSUMER GAS-FIRED STORAGE DISTRIBUTION AND TEST DATA USED FOR THIS SNOPR BY INPUT RATE
AND RATED STORAGE VOLUME *—Continued
Rated storage volume
(gallons)
Input rate
(kBtu/h)
20
60
62
65
75
.............
.............
.............
.............
28
—
—
—
0/1 (0%)
29
—
—
—
—
30
2/1 (200%)
—
—
—
38
40
—
—
—
—
48
—
—
—
—
—
—
—
—
50
1/5 (20%)
—
2/5 (40%)
—
55
0/9 (0%)
1/6 (17%)
2/3 (67%)
—
0/2 (0%)
—
—
—
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category,
and, thus, there were no units tested.
TABLE III.18—CONSUMER ELECTRIC
STORAGE DISTRIBUTION AND TEST
DATA USED FOR THIS SNOPR BY
INPUT RATE AND RATED STORAGE
VOLUME *
Rated storage volume
(gallons)
28
30
36
38
40
47
50
52
55
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
..........................................
TABLE III.19—CONSUMER GAS-FIRED
STORAGE DISTRIBUTION AND TEST
DATA USED FOR THIS SNOPR BY
INPUT RATE AND RATED STORAGE
VOLUME *
Input rate
(kBtu/h)
All input rates
5/6 (83%)
6/27 (22%)
0/1 (0%)
2/6 (33%)
12/29 (41%)
0/2 (0%)
15/26 (58%)
1/2 (50%)
4/6 (67%)
* The information in this table is presented
as the number of tested units/the number of
models available on the market. The percentage of models tested is in parentheses next to
the counts of units tested and models.
TABLE III.20—CONSUMER TABLETOP
STORAGE DISTRIBUTION AND TEST
DATA USED FOR THIS SNOPR BY
INPUT RATE AND RATED STORAGE
VOLUME *
All rated storage volumes
120 ........................................
130 ........................................
140 ........................................
145 ........................................
150 ........................................
152 ........................................
157 ........................................
160 ........................................
175 ........................................
180 ........................................
190 ........................................
192 ........................................
195 ........................................
199 ........................................
199.9 .....................................
200 ........................................
Rated storage volume
(gallons)
4/11 (36%)
0/2 (0%)
5/9 (56%)
0/1 (0%)
4/13 (31%)
3/1 (300%)
2/7 (29%)
0/6 (0%)
1/2 (50%)
9/30 (30%)
5/9 (56%)
0/1 (0%)
0/1 (0%)
6/27 (22%)
10/6 (167%)
2/13 (15%)
All input rates
27 ..........................................
38 ..........................................
40 ..........................................
1/2 (50%)
1/1 (100%)
1/2 (50%)
* The information in this table is presented
as the number of tested units/the number of
models available on the market. The percentage of models tested is in parentheses next to
the counts of units tested and models.
* The information in this table is presented
as the number of tested units/the number of
models available on the market. The percentage of models tested is in parentheses next to
the counts of units tested and models.
TABLE III.21—CONSUMER OIL-FIRED STORAGE DISTRIBUTION AND TEST DATA USED FOR THIS SNOPR BY INPUT RATE
AND RATED STORAGE VOLUME *
Rated storage volume
(gallons)
Input rate
(kBtu/h)
30
90 .................................................................................................................................................
104 ...............................................................................................................................................
105 ...............................................................................................................................................
32
50
........................
........................
0/2 (0%)
0/2 (0%)
1/2 (50%)
........................
........................
........................
0/1 (0%)
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and models.
mstockstill on DSK3G9T082PROD with PROPOSALS2
TABLE III.22—CONSUMER HEAT PUMP DISTRIBUTION AND TEST DATA USED FOR THIS SNOPR BY ENERGY FACTOR AND
RATED STORAGE VOLUME *
Rated storage volume
(gallons)
Energy
factor
45
2.2 ....................................................
2.21 ..................................................
2.31 ..................................................
2.32 ..................................................
2.33 ..................................................
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21:44 Aug 29, 2016
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50
—
—
—
—
—
PO 00000
58
1/1 (100%)
—
—
0/1 (0%)
—
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65
—
—
—
—
—
Fmt 4701
—
—
1/1 (100%)
—
—
Sfmt 4702
66
72
—
—
—
—
—
E:\FR\FM\30AUP2.SGM
80
—
—
—
—
—
30AUP2
119
—
—
1/1 (100%)
—
2/1 (200%)
—
1/1 (100%)
—
—
—
59758
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.22—CONSUMER HEAT PUMP DISTRIBUTION AND TEST DATA USED FOR THIS SNOPR BY ENERGY FACTOR AND
RATED STORAGE VOLUME *—Continued
Rated storage volume
(gallons)
Energy
factor
45
2.4 ....................................................
2.45 ..................................................
2.5 ....................................................
2.72 ..................................................
2.74 ..................................................
2.75 ..................................................
2.9 ....................................................
3.05 ..................................................
3.07 ..................................................
3.1 ....................................................
3.17 ..................................................
3.24 ..................................................
3.39 ..................................................
50
—
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
2/1 (200%)
1/2 (50%)
—
—
—
0/1 (0%)
1/1 (100%)
—
—
0/1 (0%)
—
0/1 (0%)
1/0 **
58
65
—
—
—
—
—
—
—
0/1 (0%)
—
—
—
—
—
66
—
—
—
—
—
—
—
—
—
—
—
—
—
72
—
—
0/1 (0%)
—
0/1 (0%)
—
—
—
—
—
0/1 (0%)
—
—
80
—
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
119
—
0/1 (0%)
0/1 (0%)
1/1 (100%)
—
—
1/1 (100%)
—
0/1 (0%)
1/1 (100%)
—
—
0/1 (0%)
—
—
—
—
—
—
—
—
—
—
—
—
—
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category,
and, thus, there were no units tested.
** AHRI supplied data for this model which is not contained in the version of the CCMS and AHRI databases used for this SNOPR. Due to the
high rated EF, DOE believes this unit to have recently come on to the market.
TABLE III.23—RESIDENTIAL-DUTY COMMERCIAL GAS-FIRED STORAGE TEST DATA USED FOR THIS SNOPR AND MARKET
DISTRIBUTION BY INPUT RATE AND RATED STORAGE VOLUME *
Rated storage volume
(gallons)
Input rate
(kBtu/h)
34
75 ....................
75.1 .................
76 ....................
78 ....................
80 ....................
85 ....................
88 ....................
90 ....................
91.3 .................
98 ....................
100 ..................
—
—
—
—
—
—
—
—
—
—
0/1 (0%)
40
—
—
—
—
—
—
—
—
0/1 (0%)
—
—
50
55
—
—
6/4 (150%)
—
—
—
—
—
—
0/2 (0%)
1/1 (100%)
—
—
—
0/1 (0%)
0/2 (0%)
—
—
—
—
—
0/3 (0%)
60
—
—
0/2 (0%)
—
—
—
—
—
—
—
—
74
75
—
2/3 (67%)
—
—
0/1 (0%)
—
—
—
—
—
—
0/1 (0%)
1/3 (33%)
2/21 (10%)
—
1/1 (100%)
—
—
—
—
—
1/2 (50%)
80
98
—
—
0/2 (0%)
—
—
—
—
—
—
—
0/2 (0%)
100
—
3/2 (150%)
—
—
—
—
—
0/1 (0%)
—
—
—
—
0/1 (0%)
0/3 (0%)
—
1/1 (100%)
1/3 (33%)
0/3 (0%)
—
—
—
—
119
—
—
—
—
—
—
—
—
—
—
0/2 (0%)
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category, and, thus, there were no units tested.
TABLE III.24—RESIDENTIAL-DUTY COMMERCIAL OIL-FIRED STORAGE TEST DATA USED FOR THIS SNOPR AND MARKET
DISTRIBUTION BY INPUT RATE AND RATED STORAGE VOLUME *
Rated storage volume
(gallons)
Input rate
(kBtu/h)
30
119 ...............................................................................................................................................
140 ...............................................................................................................................................
50
0/2 (0%)
—
0/1 (0%)
1/1 (100%)
70
0/1 (0%)
—
mstockstill on DSK3G9T082PROD with PROPOSALS2
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of
models tested is in parentheses below the counts of units tested and models. A ‘‘—’’ indicates that there are no models available in the category,
and, thus, there were no units tested.
As noted above, DOE received a
number of comments suggesting types of
water heaters for which the commenters
said DOE should incorporate additional
data for the development of the
conversion factors. Specifically, AHRI
and Rheem stated that more short units
should be tested and in particular,
electric short units. (AHRI, No. 13 at p.
5; Rheem, No. 11 at p. 7) For the
SNOPR, the percentage of gas-fired and
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Jkt 238001
electric short water heater models on
the market that have been tested has
increased from 7 percent to 45 percent
and from 5 percent to 28 percent,
respectively, as compared to the April
2015 NOPR. DOE notes that these
percentages are based on identification
in manufacturer literature, as there is no
consistent, objective criteria for
identifying short and tall models across
manufacturers. DOE believes that the
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models tested are representative of
‘‘short’’ models available on the market.
AHRI stated that units subject to the
low draw pattern for the consumer
electric storage category were not
adequately tested. (AHRI, No. 13 at p. 5)
Rheem also stated that not enough
consumer electric storage units were
tested, but that more testing for the
high-draw-pattern category was needed.
(Rheem, No. 13 at p. 7) As noted above,
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the draw pattern classification for DOE’s
test unit selection was based upon the
first-hour ratings based on the EF test
procedure, as the first-hour ratings
under the UEF test procedure are not
readily available in published literature.
However, the actual draw pattern for
each unit tested was found
experimentally through testing for the
first-hour rating under the UEF test
method prior to conducting the UEF
simulated-use test. For the SNOPR, the
percentage of electric low- and highdraw-pattern water heaters on the
market that have been tested has
increased from 7 percent to 28 percent
and from 0 percent to 20 percent,
respectively. These percentages are
based on the number of units that were
determined through testing to be in a
draw pattern bin as compared to the
number of models that would be
predicted to be in that draw pattern bin.
Rheem stated that no low-drawpattern consumer gas-fired water heaters
were tested. (Rheem, No. 13 at p. 7) DOE
predicted seven of the 340 (i.e., 2.1
percent) gas-fired water heater models
on the market to be in the low-drawpattern bin based on their EF test
procedure first-hour rating. For the
NOPR, one unit was tested with an
expected low-draw-pattern based on its
first-hour rating under the EF test
procedure, but that unit’s tested firsthour rating under the new UEF
procedure placed it into the mediumdraw-pattern bin. Subsequently, two
consumer gas-fired water heaters were
supplied in the AHRI dataset and tested
to the low-draw-pattern bin under the
UEF first-hour rating test. Therefore,
two low-draw-pattern tests are now
available and were included in the
analysis.
Rheem stated that there were no tests
of consumer gas-fired storage water
heaters above 55 gallons. (Rheem, No.
13 at p. 7) In response, DOE notes that
as of the time of this analysis, there are
no water heaters on the market which
would fall into this category.
AHRI and Rheem suggested that more
ultra-low NOX units should be tested.
(AHRI, No. 13 at p. 5; Rheem, No. 11 at
p. 7) For the SNOPR, the percentage of
ultra-low NOX gas-fired water heaters on
the market that have been tested has
increased from 4 percent to 34 percent.
AHRI, GE, and Rheem suggested that
more high-EF heat pump units should
be tested. (AHRI, No. 8 at p. 4; GE, No.
12 at p. 1; Rheem, No. 11 at p. 7) For
the SNOPR, the percentage of high-EF
(i.e., EF greater than 2.7) heat pump
water heaters on the market that have
been tested has increased from 0 percent
to 42 percent.
AHRI and Rheem commented that the
sample size for the residential-duty gasfired storage category was too small.
(AHRI, No. 13 at p. 6; Rheem, No. 11 at
p. 7) AHRI and Rheem also stated that
no residential-duty units in the highinput range were tested. (AHRI, No. 8 at
p. 4; Rheem, No. 11 at p. 7) For the
SNOPR, the percentage of residentialduty commercial gas-fired storage water
heaters on the market that have been
tested has increased from 7 percent to
28 percent, and the percentage of highinput (i.e., input rate greater than 90,000
Btu/h) units has increased from 0
percent to 14 percent.
1. Repeatability
In response to the April 2015 NOPR,
commenters stated that the repeatability
of the UEF test procedure was not
analyzed. (AHRI, No. 8 at p. 5; Rheem,
No. 11 at p. 6) In response, DOE
acknowledges that each water heater
was tested once, and repeat tests of the
same unit were not conducted by DOE.
During its test procedure rulemaking to
establish the UEF test method,
stakeholders did not raise concerns
regarding repeatability, and, therefore,
DOE did not specifically evaluate this
issue during testing conducted for the
NOPR. However, AHRI submitted data
that appears to show the variations in
59759
the experimental results from testing a
given unit are unlikely to contribute
more than a de minimis amount of
uncertainty to the overall regression.
One consumer electric storage water
heater (Test ID No. 1–61 and 1–62) and
one consumer gas-fired instantaneous
water heater (Test ID No. 1–83 and 1–
84) were tested multiple times. For the
consumer electric storage water heater,
the only difference between the two
tests was the result of the EF test
procedure’s first-hour rating test
(difference of 3 gallons). For the gasfired instantaneous water heater, the
differences in the EF test procedure
maximum GPM, EF, UEF test procedure
maximum GPM, and UEF results were
0.019 gpm, 0.0017, 0.0002 gpm, and
0.0012, respectively. (AHRI, No. 9
Attachment) These data suggest that the
EF and UEF test procedures are
repeatable.
For this SNOPR, DOE conducted
additional testing that allowed DOE to
further examine the repeatability of the
test method. DOE tested eight units, two
different units of one model and 3
different units of 2 other models.
Because the different units may have
slightly different EF or UEF
characteristics, the variability in these
results is an upper bound for the
variability introduced by the test
methods themselves. The variability
was similar for all three, and DOE has
no reason to think the test methods
would produce significantly different
levels of variability for other types of
water heaters. The results of the testing
are shown in Table III.25. The standard
deviations of the EF and UEF tests for
models 1, 2, and 3 are 0.0018 and
0.0035, 0.0033 and 0.0044, and 0.0149
and 0.0116, respectively. These
standard deviations are all within the
same magnitude for each model and for
the case of model 3 the UEF standard
deviation is less than EF. The results
indicate a reasonable level of
repeatability in the test procedure.
TABLE III.25—RESULTS FOR REPEATABILITY TESTING FOR EF AND UEF TEST METHODS
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Model
1
1
2
2
2
3
3
3
Unit
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
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Rated EF
1
2
1
2
3
1
2
3
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0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
30AUP2
Tested EF
0.947
0.949
0.937
0.940
0.934
0.908
0.932
0.905
Tested UEF
.949
.944
.903
.909
.901
.914
.898
.892
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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 prior 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 would warrant separate
conversion equations. DOE investigated
attributes such as: (1) NOX emission
level; (2) short or tall configuration; (3)
vent type; (4) standing pilot versus
electronic ignition; (5) whether
condensing or heat pump technology is
used; and (6) whether the unit is
tabletop. The RMSD between the
measured values and the values
obtained through various conversion
methods was compared. The conversion
approach with the lowest cumulative
RMSD value for a particular fuel type
was considered to be the best candidate
for the conversion equation.
In the April 2015 NOPR, DOE
proposed to adopt different conversion
equations based on the level of NOX
emissions. 80 FR 20116, 20129–30
(April 14, 2015). 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
less than 40 ng/J 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).
AHRI commented that separate
conversions for standard and low-NOX
water heaters are not needed. (AHRI,
No. 8 at p. 4) As a result, DOE reexamined the data to determine the
variability of the conversions when
considering standard and low-NOX
water heaters together, and separately
from ultra-low-NOX water heaters. DOE
found that the combined approach
recommended by AHRI slightly reduces
the variability of the conversion
equations, and, thus, the Department
has included standard and low-NOX
water heaters in a single set of
conversion equations in this
supplemental proposal. The proposal
continues to treat ultra-low-NOX water
heaters separately, because an ultra-lowNOX burner has a fundamentally
different design than standard and low-
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Jkt 238001
NOX burners and the resulting RMSD
values are lower for each category when
separated.
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 ‘‘short’’
are actually taller than units labeled as
‘‘tall.’’ In the NOPR, DOE requested
comment on how manufacturers
determine whether a unit is short or tall.
80 FR 20116, 20129 (April 14, 2015). No
response was received related to this
inquiry, so DOE considered
manufacturer literature in determining
whether a model was ‘‘tall’’ or ‘‘short,’’
although as noted, the criteria for
classification was not always consistent
across manufacturers. DOE examined
separate conversions for tall and short
water heaters based on their
identification in manufacturer literature;
however, DOE ultimately did not
propose separate conversions because it
did not yield materially different results
and is not based on discrete design
characteristics that are consistent across
all manufacturers.
As explained in the April 2015 NOPR,
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
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 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, in terms of the comparison
between EF and UEF, between
atmospheric and direct vent water
heaters and also between power and
power-direct vent. For these reasons
DOE grouped atmospheric and direct
into the atmospheric configuration and
power and power-direct into the power
configuration. Similarly, DOE
determined that there was not a
significant difference between electronic
ignition and standing pilot units and
grouped those together for this
conversion. 80 FR 20116, 20129–30
(April 14, 2015).
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Rheem commented that DOE should
test ultra-low-NOX consumer gas-fired
storage water heaters that use a power
vent to determine whether a different
UEF conversion factor is warranted to
differentiate between the different vent
types of ultra-low-NOX water heaters.
(Rheem, No. 11 at p. 7) AHRI submitted
test data for 17 ultra-low-NOX consumer
gas-fired water heaters: 9 that are
atmospherically vented and 8 that are
power vented. DOE analyzed separating
the ultra-low-NOX consumer gas-fired
storage category into atmospherically
vented and power vented categories,
and found that the RMSD value
decreased by less than 0.001 when
separated. DOE tentatively considers a
change in RMSD to be negligible if it is
less than one unit (0.01 for EF and UEF,
0.1 for maximum GPM, and 1.0 for firsthour rating). DOE has tentatively
decided that this decrease is not
significant enough to justify a separate
conversion, given the additional
complexity of separating these products
by vent type.
In the April 2015 NOPR, DOE
tentatively concluded that tabletop units
were not significantly different from
electric resistance storage water heaters
and considered them together for the
purposes of developing the
mathematical conversion. 80 FR 20116,
20132 (April 14, 2015). Upon further
consideration, DOE believes that
tabletop units, due to their efficiency
ratings being well below those of
traditional electric storage water heaters,
may react differently to the UEF test
procedure than traditional electric
storage water heaters. Therefore, DOE
has tentatively decided to propose
separate conversions for tabletop and
electric resistance water heaters in this
SNOPR.
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.
In response to the April 2015 NOPR,
Rheem commented generally that DOE
did not specify how it determined
whether the proposed UEF conversion
factors and minimum standards were
acceptable and do not effectively amend
the energy conservation standards.
(Rheem, No. 11 at p. 5) AHRI stated that
the tested UEF values do not align with
the converted UEF values. (AHRI, No.
13 at p. 4) Regarding the conversion
factors, DOE examined multiple
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approaches and, in most cases, chose
the approach that yielded the lowest
RMSD value. For certain conversions,
DOE chose an approach where the
RMSD value was slightly higher, but
negligibly so, in favor of a simpler
approach to the conversion. (As stated
in section III.E.1, DOE tentatively
considers a change in RMSD to be
negligible if it is less than one unit (0.01
for EF and UEF, 0.1 for maximum GPM,
and 1.0 for first-hour rating).) In
examining whether the proposed
conversion factors are appropriate, DOE
considered its certification policies for
water heaters contained in 10 CFR part
429. Recognizing the variation in
materials, the manufacturing process,
and testing, DOE provides bounds on
acceptable representations of efficiency
for certifying represented values. DOE
requires the manufacturer to rate the
efficiency of a basic model between the
Federal energy conservation standard
and up to the lower of the mean of the
sample or the 95-percent lower
confidence limit divided by 0.9. 10 CFR
429.17. DOE examined the variability
between the tested EF and the rated EF
for each model tested for this
rulemaking by determining the standard
deviation for each sample grouping (i.e.,
the sample data points included for
each conversion equation) in order to
estimate the amount of variation
allowed by DOE’s rating requirements at
10 CFR 429.17. DOE then compared the
standard deviation of the tested EF
values to the RMSD of predicted UEF
values.10 For all product classes, the
RMSD of the UEF values was less than
or equal to the standard deviation of the
EF values when rounded to the nearest
0.01, indicating that the variability of
the predicted conversion values is less
than or equal to that of the tested EF
values observed in a sample of models
under the current test procedure. In
addition, DOE’s approach to ensuring
the energy conservation standards are
not effectively amended is discussed
further in section III.E.3.
NEEA stated that the April 2015
NOPR did not deliver a set of
mathematical conversion factors that
would enable the marketplace (or
anyone else) to rely on the resulting
UEF ratings or the proposed UEF
standards equations that are derived
from those ratings. (NEEA, No. 15 at p.
2) DOE disagrees with NEEA, and
believes that the UEF values predicted
using the mathematical conversions are
reasonable, as evidenced by the
resulting RMSD values. RMSD is a
measure of the differences between
values predicted by a model and those
actually observed. As discussed above,
the RMSD values for the predicted UEF
were less than or equal to the standard
deviation of the tested EF values for
each class of water heater, suggesting
that the mathematical conversion factors
presented are reasonably accurate.
a. Consumer Storage Water Heaters
i. Test Results
models using both the EF and UEF test
procedures, and likewise, AHRI has
supplied test data for 130 consumer
storage water heater models using both
the EF and UEF test procedures.11 12
Table III.26 presents the test data used
to derive the consumer storage water
heater conversion factors. Table III.27
shows the water heater attributes by
unit. DOE notes that 1 of the 2 oil-fired
storage water heaters, 1 of the 46 electric
storage water heaters, and 3 of the 118
gas-fired storage water heaters that were
included in the testing and analysis had
manufacturer self-declared ratings
below the current energy conservation
standards (compliance required April
16, 2015). Although the rated efficiency
of these water heaters are below the
energy conservation standards, DOE
believes it is appropriate to use data
from these models, because the
difference between the relevant
parameters under the new and old test
procedures (i.e., first-hour rating, EF,
and UEF) are likely to be similar to
those of a model rated to meet the
energy conservation standards. Thus,
DOE believes this model is relevant for
evaluating the conversion factor which
is intended to establish the relationship
between ratings under the UEF and EF
test procedures. Therefore, DOE has
considered these models in its analysis
for determining the mathematical
conversion factors.
In total, DOE has conducted testing of
55 consumer storage water heater
TABLE III.26—CONSUMER STORAGE WATER HEATER TEST DATA
CS No.
mstockstill on DSK3G9T082PROD with PROPOSALS2
1 ....................
2 ....................
3 ....................
4 ....................
5 ....................
6 ....................
7 ....................
8 ....................
9 ....................
10 ..................
11 ..................
12 ..................
13 ..................
14 ..................
AHRI 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
......................
......................
......................
......................
......................
......................
......................
......................
......................
......................
......................
......................
......................
......................
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
.....................
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.....................
.....................
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.....................
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.....................
10 DOE examined RMSD as the measure of the
variability between tested and predicted UEF
values, as it is a common measure of the accuracy
of a model and is often used to compare predicted
and measured values. In comparing measured
versus rated values for EF, DOE examined standard
deviation, which represents the variability of a
sample in relation to the mean of that sample. In
this case, DOE assumes that the rated EF will
represent the mean of the sample. DOE recognizes
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Storage
volume
(gal)
Type
Jkt 238001
Input rate
(Btu/h)
Prior FHR
(gal)
40,000
39,800
39,400
44,100
38,300
40,500
40,100
50,600
39,300
31,600
40,200
32,400
39,800
59,600
73.8
91.0
74.5
97.5
71.4
73.5
80.2
95.2
71.9
59.0
74.9
68.7
70.2
96.9
36.8
45.6
37.8
49.4
38.2
38.0
37.9
47.2
38.1
27.8
38.1
38.8
38.4
27.7
that under its certification regulation, rated EF may
actually be different from the mean of a sample. For
purposes of assessing the scope of variability, that
difference will not be important.
11 The AHRI submitted data points 2–5 and 2–6
were not used in this analysis as the reported
recovery efficiencies were 98 percent and not
calculated from test data.
12 If multiple tests were conducted on either the
same unit or same basic model of a water heater,
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Updated
FHR
(gal)
Prior
recovery
efficiency
(%)
104.2
85.0
80.9
86.7
64.8
75.7
63.8
87.7
77.8
64.4
70.9
65.1
74.1
94.6
92.2
96.2
80.5
78.8
76.4
83.6
83.6
78.3
75.8
78.8
78.5
77.9
80.4
78.2
EF
0.790
0.836
0.692
0.610
0.625
0.702
0.711
0.608
0.607
0.619
0.618
0.664
0.673
0.702
UEF
0.802
0.826
0.714
0.634
0.600
0.719
0.669
0.635
0.635
0.605
0.570
0.624
0.654
0.718
the results were averaged to produce the values
reported in this SNOPR. In one instance within the
AHRI-submitted data for consumer storage water
heaters, three tests were conducted, where two tests
were conducted on the same unit and another test
was conducted on a unit of the same basic model.
The two tests of the same unit were averaged, and
this value was then averaged with the results of the
test of the unit of the same basic model.
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TABLE III.26—CONSUMER STORAGE WATER HEATER TEST DATA—Continued
mstockstill on DSK3G9T082PROD with PROPOSALS2
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17
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19
20
21
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34
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37
38
39
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..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
VerDate Sep<11>2014
Storage
volume
(gal)
AHRI No.
Type
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 ......................
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 ......................
N/A ......................
N/A ......................
N/A ......................
N/A ......................
N/A ......................
1–1 ......................
1–2 ......................
CGS–11 ..............
1–6 ......................
1–11 ....................
1–34 ....................
1–41 ....................
CGS–14 ..............
CGS–19 ..............
CGS–23 ..............
CGS–26 ..............
CGS–32 ..............
CGS–36 ..............
CGS–37 ..............
CGS–38 ..............
CGS–4 ................
CGS–6 ................
CGS–8 ................
1–9 ......................
1–4 ......................
1–7 ......................
1–8 ......................
1–12 ....................
1–13 ....................
1–14 ....................
1–15 ....................
1–17 ....................
1–18 ....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Oil ........................
Oil ........................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Tabletop ..............
Tabletop ..............
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
21:44 Aug 29, 2016
Jkt 238001
PO 00000
Frm 00028
Input rate
(Btu/h)
Prior FHR
(gal)
36,300
49,900
64,600
40,000
39,700
40,300
33,000
36,000
40,500
29,500
39,700
44,800
104,000
105,100
15,100
15,400
15,400
16,300
15,200
15,300
14,800
15,400
13,000
18,100
15,000
15,400
15,000
14,900
14,800
15,300
15,200
15,600
15,400
15,200
15,400
15,400
15,000
11,100
15,300
15,700
1,800
39,300
40,400
40,600
39,900
29,600
39,900
38,500
40,200
35,400
39,500
30,600
37,400
34,700
38,600
30,600
40,100
50,500
37,600
59,100
39,200
35,300
40,200
37,800
37,700
37,700
31,400
37,900
37,400
66.0
90.2
108.0
67.0
70.2
68.3
56.1
92.1
94.2
50.4
87.9
103.2
112.5
104.8
41.4
42.9
55.5
40.8
53.2
56.5
66.8
61.1
38.7
68.6
53.8
62.7
66.1
53.8
64.9
80.7
63.7
60.7
52.4
52.9
37.5
64.5
57.3
59.1
71.5
90.5
57.0
91.6
89.5
87.5
65.2
55.4
68.5
70.0
94.9
66.8
89.2
52.5
74.4
74.9
71.3
55.1
64.2
84.9
84.1
93.0
88.4
79.5
78.0
75.0
94.7
86.3
57.1
87.4
75.4
38.4
47.9
47.8
38.4
37.8
38.1
28.6
48.1
47.7
26.5
45.6
54.1
30.1
29.8
25.7
25.8
35.0
25.1
36.2
45.1
46.0
46.0
26.7
49.7
35.8
45.3
45.2
36.0
44.8
54.5
45.0
44.7
35.9
35.0
25.0
45.4
45.5
45.1
58.8
77.5
80.8
45.7
47.9
47.5
39.0
28.8
38.0
38.2
48.5
27.9
49.3
28.7
38.3
38.6
39.0
28.7
38.7
47.4
48.3
28.2
47.9
47.9
47.9
38.2
48.0
47.6
28.0
47.8
38.9
Fmt 4701
Sfmt 4702
Updated
FHR
(gal)
Prior
recovery
efficiency
(%)
68.1
81.1
108.8
81.1
87.0
64.8
70.6
88.2
84.0
51.5
83.2
97.9
127.4
111.6
39.7
42.9
52.3
46.2
50.0
65.3
59.9
59.8
43.2
73.3
48.5
64.2
68.7
54.8
59.4
77.2
56.8
64.8
51.9
48.0
45.3
56.1
58.9
48.7
68.6
87.1
58.0
86.9
77.3
78.8
75.6
52.8
69.5
75.9
89.5
67.9
70.0
51.9
70.6
68.0
62.5
59.6
78.8
115.0
78.5
97.9
80.7
69.6
70.8
71.5
87.2
81.7
50.6
81.7
73.6
E:\FR\FM\30AUP2.SGM
85.0
81.1
79.8
80.5
80.2
74.1
82.2
80.6
72.5
80.8
77.8
77.2
89.4
71.4
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
282.9
270.3
264.7
296.9
288.2
288.0
91.0
80.3
83.5
77.6
80.2
82.3
85.7
82.9
79.9
77.1
77.4
78.7
79.5
81.0
78.8
79.1
78.8
79.5
80.3
79.7
81.8
79.0
79.4
77.6
75.9
83.5
80.8
81.8
30AUP2
EF
0.699
0.674
0.654
0.601
0.610
0.602
0.610
0.630
0.547
0.644
0.593
0.577
0.605
0.518
0.949
0.936
0.941
0.944
0.940
0.930
0.917
0.948
0.912
0.914
0.927
0.922
0.949
0.917
0.958
0.959
0.937
0.915
0.932
0.877
0.905
2.486
2.270
2.260
2.280
2.270
2.330
0.789
0.682
0.697
0.600
0.636
0.649
0.719
0.625
0.626
0.587
0.612
0.645
0.624
0.622
0.625
0.602
0.580
0.675
0.688
0.605
0.608
0.596
0.632
0.597
0.575
0.648
0.592
0.633
UEF
0.677
0.676
0.680
0.628
0.641
0.598
0.561
0.662
0.640
0.603
0.617
0.596
0.641
0.528
0.903
0.891
0.937
0.902
0.906
0.909
0.932
0.946
0.902
0.942
0.868
0.931
0.919
0.941
0.926
0.952
0.904
0.901
0.922
0.805
0.859
1.948
2.572
2.071
2.496
2.642
2.540
0.806
0.704
0.729
0.653
0.597
0.595
0.750
0.649
0.597
0.560
0.578
0.651
0.574
0.577
0.596
0.637
0.611
0.711
0.718
0.656
0.580
0.593
0.558
0.613
0.611
0.598
0.622
0.588
59763
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.26—CONSUMER STORAGE WATER HEATER TEST DATA—Continued
Storage
volume
(gal)
mstockstill on DSK3G9T082PROD with PROPOSALS2
CS No.
AHRI No.
Type
84 ..................
85 ..................
86 ..................
87 ..................
88 ..................
89 ..................
90 ..................
91 ..................
92 ..................
93 ..................
94 ..................
95 ..................
96 ..................
97 ..................
98 ..................
99 ..................
100 ................
101 ................
102 ................
103 ................
104 ................
105 ................
106 ................
107 ................
108 ................
109 ................
110 ................
111 ................
112 ................
113 ................
114 ................
115 ................
116 ................
117 ................
118 ................
119 ................
120 ................
121 ................
122 ................
123 ................
124 ................
125 ................
126 ................
127 ................
128 ................
129 ................
130 ................
131 ................
132 ................
133 ................
134 ................
135 ................
136 ................
137 ................
138 ................
139 ................
140 ................
141 ................
142 ................
143 ................
144 ................
145 ................
146 ................
147 ................
148 ................
149 ................
150 ................
151 ................
152 ................
1–30 ....................
1–33 ....................
CGS–1 ................
CGS–13 ..............
CGS–15 ..............
CGS–17 ..............
CGS–18 ..............
CGS–2 ................
CGS–21 ..............
CGS–22 ..............
CGS–24 ..............
CGS–25 ..............
CGS–3 ................
CGS–30 ..............
CGS–33 ..............
CGS–34 ..............
CGS–39 ..............
CGS–40 ..............
CGS–41 ..............
CGS–5 ................
CGS–7 ................
2–1 ......................
2–3 ......................
1–5, 10 ................
1–35 ....................
1–36 ....................
1–43 ....................
CGS–12 ..............
CGS–31 ..............
CGS–35 ..............
2–2 ......................
1–3 ......................
1–37 ....................
CGS–10 ..............
CGS–16 ..............
CGS–9 ................
1–22 ....................
1–51 ....................
1–19 ....................
1–21 ....................
1–25 ....................
1–50 ....................
1–47 ....................
1–48 ....................
1–49 ....................
1–20 ....................
1–52 ....................
1–16 ....................
1–44 ....................
1–27, 28, 29 ........
1–26 ....................
1–45 ....................
CGS–20 ..............
CGS–27 ..............
CGS–28 ..............
CGS–29 ..............
1–40 ....................
1–42 ....................
1–46 ....................
1–23 ....................
1–31 ....................
1–38 ....................
1–39 ....................
1–24, 32 ..............
1–68 ....................
CES–11 ...............
CES–12 ...............
CES–13 ...............
CES–14 ...............
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Gas .....................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
VerDate Sep<11>2014
21:44 Aug 29, 2016
Jkt 238001
PO 00000
Frm 00029
Input rate
(Btu/h)
Prior FHR
(gal)
47.8
48.0
37.8
47.9
54.9
28.8
38.3
47.7
28.7
47.8
38.8
47.6
47.6
28.7
26.6
28.4
38.3
38.4
38.3
48.5
46.1
28.6
45.7
38.4
46.0
38.1
38.1
49.7
38.3
38.2
48.2
48.1
48.1
38.1
47.9
48.6
39.1
38.4
38.2
48.1
48.2
48.1
38.1
47.5
47.5
47.9
47.9
36.8
48.6
39.0
48.1
38.0
37.8
28.9
38.3
39.4
38.1
48.3
38.3
38.3
47.9
37.8
46.1
48.1
36.1
28.6
38.4
49.8
48.6
40,000
40,000
39,300
36,300
49,600
29,600
33,400
40,300
36,000
39,600
34,500
40,400
40,800
32,100
31,900
29,900
35,500
29,400
37,400
40,100
64,500
32,000
64,900
39,500
60,000
39,300
39,300
39,400
39,700
40,600
39,800
41,200
39,400
37,800
65,700
39,800
40,100
38,100
40,700
40,400
39,500
39,700
39,600
61,400
39,500
49,700
44,100
36,000
39,200
35,900
38,200
39,300
39,900
30,500
40,700
40,800
40,700
39,800
39,200
41,600
42,000
39,200
50,000
42,100
15,400
15,400
15,400
15,400
15,400
83.0
83.5
67.7
75.6
100.1
51.8
56.1
87.2
67.8
78.2
59.9
84.3
83.1
63.0
52.8
52.3
76.7
59.0
73.7
89.2
103.3
81.1
100.0
65.7
100.0
71.8
69.3
90.6
70.8
69.4
83.6
87.9
86.5
71.7
112.5
92.5
69.4
71.2
77.2
87.5
86.6
91.7
68.6
112.0
85.2
92.4
86.9
67.3
94.8
62.6
83.5
74.4
75.0
57.0
72.9
72.0
71.8
86.0
71.8
68.2
68.0
87.2
97.4
80.2
53.6
42.1
49.7
63.6
59.4
Fmt 4701
Sfmt 4702
Updated
FHR
(gal)
Prior
recovery
efficiency
(%)
73.0
67.0
83.8
84.4
89.3
48.2
50.7
80.8
65.1
71.8
59.9
74.6
75.9
55.0
57.8
60.4
72.0
53.7
68.6
82.3
130.2
67.7
113.0
64.9
113.0
68.6
68.6
81.5
66.0
67.3
81.3
80.1
82.9
78.5
114.4
90.7
87.9
65.1
65.8
82.0
76.5
78.6
77.4
104.9
75.9
86.5
79.7
61.6
91.6
61.1
73.9
75.1
68.4
67.7
66.9
73.5
68.8
85.8
68.1
84.7
85.0
66.5
92.6
74.0
51.2
45.9
57.4
63.3
54.3
E:\FR\FM\30AUP2.SGM
79.0
79.0
78.8
78.3
83.5
81.6
82.6
77.7
85.0
80.7
77.4
77.0
83.0
79.7
81.2
83.7
79.1
77.3
81.4
80.5
83.9
82.5
82.5
79.1
82.5
81.2
79.8
81.6
78.0
80.5
77.5
75.2
80.0
82.9
78.3
81.6
79.3
79.5
80.0
76.6
79.2
80.9
79.7
82.1
81.3
81.7
81.2
80.9
77.4
79.4
82.7
78.3
78.0
79.3
79.3
78.3
77.1
80.9
79.1
82.6
82.0
80.2
81.8
87.2
98.0
98.0
98.0
98.0
98.0
30AUP2
EF
0.610
0.610
0.611
0.588
0.618
0.679
0.633
0.605
0.657
0.615
0.606
0.585
0.634
0.623
0.647
0.630
0.613
0.596
0.634
0.619
0.601
0.653
0.624
0.602
0.624
0.688
0.675
0.699
0.651
0.691
0.652
0.640
0.666
0.697
0.642
0.689
0.667
0.614
0.680
0.606
0.590
0.612
0.679
0.683
0.661
0.673
0.682
0.615
0.625
0.625
0.634
0.623
0.575
0.628
0.578
0.602
0.610
0.673
0.660
0.677
0.680
0.682
0.669
0.710
0.961
0.947
0.944
0.954
0.923
UEF
0.580
0.640
0.654
0.644
0.646
0.603
0.535
0.614
0.620
0.557
0.588
0.556
0.669
0.607
0.623
0.596
0.552
0.556
0.620
0.652
0.646
0.621
0.654
0.571
0.654
0.633
0.646
0.713
0.626
0.662
0.689
0.685
0.646
0.725
0.693
0.704
0.699
0.576
0.658
0.639
0.636
0.636
0.689
0.690
0.674
0.676
0.691
0.592
0.613
0.602
0.592
0.647
0.529
0.597
0.529
0.580
0.648
0.715
0.633
0.699
0.700
0.560
0.688
0.682
0.942
0.897
0.922
0.911
0.920
59764
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.26—CONSUMER STORAGE WATER HEATER TEST DATA—Continued
CS No.
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
Storage
volume
(gal)
AHRI No.
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
................
Type
CES–2 .................
CES–3 .................
CES–4 .................
CES–5 .................
CES–6 .................
CES–7 .................
CES–8 .................
CES–9 .................
2–4 ......................
2–7 ......................
2–8 ......................
1–64 ....................
1–65 ....................
1–66 ....................
1–53 ....................
1–54 ....................
1–56 ....................
1–57 ....................
1–58 ....................
1–59 ....................
1–69 ....................
1–60, 61, 62 ........
1–55 ....................
1–70 ....................
CES–1 .................
CES–10 ...............
CES–15 ...............
CES–16 ...............
CES–17 ...............
1–71, 72 ..............
1–76 ....................
1–63, 67 ..............
1–73, 74, 75 ........
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Electric ................
Tabletop ..............
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Heat Pump ..........
Input rate
(Btu/h)
Prior FHR
(gal)
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,400
15,700
15,400
15,700
16,000
16,000
16,000
15,700
15,700
15,400
15,700
41.1
43.7
52.5
46.4
80.5
66.4
63.7
54.2
59.0
64.9
45.3
55.0
58.0
48.0
64.3
53.9
47.7
57.5
71.0
59.1
59.3
65.3
45.6
64.5
98.4
69.3
74.9
101.7
71.3
69.2
96.0
81.8
95.7
25.8
25.6
34.7
27.7
54.7
45.2
45.2
36.1
39.0
40.6
27.3
36.3
45.7
27.1
45.5
36.4
27.4
36.4
54.8
36.2
45.4
48.0
36.0
45.4
81.8
45.6
73.3
107.9
58.7
45.5
75.5
77.5
75.5
Updated
FHR
(gal)
Prior
recovery
efficiency
(%)
38.6
41.4
57.3
49.1
66.4
64.2
60.7
51.5
55.0
59.4
36.5
52.0
61.0
48.0
60.1
55.6
42.1
51.3
61.1
57.0
58.3
61.0
58.3
61.1
94.6
64.1
78.4
100.1
52.3
66.1
89.6
74.8
89.4
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
98.0
289.0
304.8
369.5
249.3
214.0
246.4
366.7
386.5
262.1
368.1
EF
0.937
0.911
0.935
0.940
0.933
0.939
0.930
0.914
0.950
0.960
0.962
0.950
0.940
0.930
0.939
0.932
0.943
0.941
0.936
0.941
0.947
0.940
0.873
2.450
2.617
3.278
2.297
1.971
2.291
3.230
3.310
2.242
3.207
UEF
0.897
0.890
0.938
0.898
0.933
0.912
0.910
0.888
0.920
0.926
0.878
0.950
0.930
0.870
0.919
0.929
0.911
0.915
0.907
0.931
0.922
0.910
0.873
2.470
2.439
3.270
2.424
2.137
2.219
3.140
3.330
2.270
3.186
TABLE III.27—CONSUMER STORAGE WATER HEATER ATTRIBUTES
mstockstill on DSK3G9T082PROD with PROPOSALS2
CS No.
NOX Emission level
Condensing
Vent type
Short or tall
1 ....................................................
2 ....................................................
3 ....................................................
4 ....................................................
5 ....................................................
6 ....................................................
7 ....................................................
8 ....................................................
9 ....................................................
10 ..................................................
11 ..................................................
12 ..................................................
13 ..................................................
14 ..................................................
15 ..................................................
16 ..................................................
17 ..................................................
18 ..................................................
19 ..................................................
20 ..................................................
21 ..................................................
22 ..................................................
23 ..................................................
24 ..................................................
25 ..................................................
26 ..................................................
27 ..................................................
28 ..................................................
29 ..................................................
30 ..................................................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Standard ................
Standard ................
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Yes ........................
Yes ........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Power ....................
Power ....................
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Short .....................
Tall ........................
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Short .....................
Tall ........................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Short .....................
Short .....................
VerDate Sep<11>2014
21:44 Aug 29, 2016
Jkt 238001
PO 00000
Frm 00030
Fmt 4701
Sfmt 4702
E:\FR\FM\30AUP2.SGM
30AUP2
Standing pilot
No.
No.
No.
Yes.
Yes.
No.
No.
Yes.
Yes.
Yes.
Yes.
No.
No.
No.
No.
No.
No.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
No.
No.
N/A.
N/A.
59765
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.27—CONSUMER STORAGE WATER HEATER ATTRIBUTES—Continued
mstockstill on DSK3G9T082PROD with PROPOSALS2
CS No.
NOX Emission level
31 ..................................................
32 ..................................................
33 ..................................................
34 ..................................................
35 ..................................................
36 ..................................................
37 ..................................................
38 ..................................................
39 ..................................................
40 ..................................................
41 ..................................................
42 ..................................................
43 ..................................................
44 ..................................................
45 ..................................................
46 ..................................................
47 ..................................................
48 ..................................................
49 ..................................................
50 ..................................................
51 ..................................................
52 ..................................................
53 ..................................................
54 ..................................................
55 ..................................................
56 ..................................................
57 ..................................................
58 ..................................................
59 ..................................................
60 ..................................................
61 ..................................................
62 ..................................................
63 ..................................................
64 ..................................................
65 ..................................................
66 ..................................................
67 ..................................................
68 ..................................................
69 ..................................................
70 ..................................................
71 ..................................................
72 ..................................................
73 ..................................................
74 ..................................................
75 ..................................................
76 ..................................................
77 ..................................................
78 ..................................................
79 ..................................................
80 ..................................................
81 ..................................................
82 ..................................................
83 ..................................................
84 ..................................................
85 ..................................................
86 ..................................................
87 ..................................................
88 ..................................................
89 ..................................................
90 ..................................................
91 ..................................................
92 ..................................................
93 ..................................................
94 ..................................................
95 ..................................................
96 ..................................................
97 ..................................................
98 ..................................................
99 ..................................................
100 ................................................
101 ................................................
102 ................................................
VerDate Sep<11>2014
21:44 Aug 29, 2016
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
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
Jkt 238001
PO 00000
Condensing
Vent type
Short or tall
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 ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Yes ........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
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 ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Power ....................
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Tall ........................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Frm 00031
Fmt 4701
Sfmt 4702
E:\FR\FM\30AUP2.SGM
30AUP2
Standing pilot
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.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
No.
No.
No.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
No.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
59766
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.27—CONSUMER STORAGE WATER HEATER ATTRIBUTES—Continued
mstockstill on DSK3G9T082PROD with PROPOSALS2
CS No.
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
NOX Emission level
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
VerDate Sep<11>2014
21:44 Aug 29, 2016
Condensing
Vent type
Short or tall
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Low ........................
Standard ................
Standard ................
Standard ................
Standard ................
Standard ................
Standard ................
Standard ................
Standard ................
Standard ................
Standard ................
Standard ................
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-Low ...............
Ultra-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 ........................
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 ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
No .........................
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 ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Not Specified ........
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Atmospheric ..........
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
Power ....................
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 ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
N/A ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Not Specified ........
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Short .....................
Short .....................
Short .....................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
Tall ........................
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30AUP2
Standing pilot
Yes.
Yes.
Yes.
Yes.
Yes.
Not Specified.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
Yes.
No.
Yes.
Yes.
Yes.
No.
No.
No.
No.
No.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
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.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
59767
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.27—CONSUMER STORAGE WATER HEATER ATTRIBUTES—Continued
CS No.
175
176
177
178
179
180
181
182
183
184
185
NOX Emission level
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
................................................
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
ii. Conversion Factor Results
For consumer storage water heaters,
DOE is proposing to use the regression
method described in section III.C.5 to
predict first-hour ratings (FHRs) under
the UEF test procedure to be used in the
Condensing
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
Vent type
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Short or tall
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
........................
conversion to UEF since no ‘‘analytical
approach’’ has been developed. Of the
factors considered, DOE found that the
first-hour rating determined under the
EF test procedure was the best overall
predictor of the new first-hour rating.
These findings were based on the
Short .....................
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Not Specified ........
Tall ........................
Tall ........................
Tall ........................
Standing pilot
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A.
N/A
RMSDs between predictions and
measured values. The resulting
equations, which are proposed for
determining the new FHR of consumer
storage water heaters, are presented in
Table III.28.
TABLE III.28—PROPOSED CONSUMER STORAGE WATER HEATER FIRST-HOUR RATING CONVERSION FACTOR EQUATIONS
Product class
Distinguishing criteria
Consumer Gas-fired Water Heater ...................
Non-Condensing, Standard or Low NOX .........
Non-Condensing, Ultra-Low NOX .....................
Condensing ......................................................
N/A ....................................................................
Electric Resistance ...........................................
Tabletop ............................................................
Heat Pump .......................................................
New
New
New
New
New
New
New
No. 13 at p. 2) Bradford White
commented that its testing showed that
the FHR for most models went down
with the change in test procedure, some
of which were affected more than
others. (Bradford White, No. 14 at p. 2)
NEEA stated that the conversion factors
that convert prior FHR ratings to new
FHR ratings produce unacceptably large
deviations from the measured FHR
ratings for a significant majority of the
water heaters tested. Further, NEEA
commented that these large variations
caused 9 of 43 water heaters tested to
fall into a different draw bin using the
conversion as compared to the tested
rating, and it recommended that given
the critical nature of the FHR in
selecting the proper draw pattern, DOE
should not attempt to mathematically
derive FHR and maximum GPM ratings,
but should instead require them to be
measured in accordance with the new
test procedures. (NEEA, No. 15 at pp. 5–
6)
In response, DOE notes that it
explored several possible conversions
for developing the FHR conversion. The
best trend was observed based on a
regression as a function of first-hour
rating. The average RMSD value
resulting from this approach (7.56
gallons) is the lowest RMSD observed in
the FHR analysis, and DOE is unaware
of any approaches that would result in
improved accuracy. Further, as
discussed above in section III.E.2, the
predicted UEF values (which are based
in part on the predicted FHR values due
to the dependence of draw pattern on
FHR) are reasonable because they are
less than the variability currently
allowed in DOE’s regulations that
manufacturers are required to use and
rate their basic models. DOE seeks
further comment regarding other
methods for predicting FHR that could
result in lower RMSDs. In the absence
of any known alternatives, DOE plans to
continue the use of this methodology,
but seeks further comment on other
approaches for converting first-hour
ratings.
After determining the converted firsthour rating, the next step in the
conversion process is to determine
which draw pattern is to be applied to
convert from EF to UEF. After the firsthour rating under the uniform efficiency
descriptor is determined using 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 1 of the
mstockstill on DSK3G9T082PROD with PROPOSALS2
Consumer Oil-fired Water Heater ......................
Consumer Electric Water Heater ......................
New FHR is the predicted first-hour
rating that would result under the UEF
test method and is used for conversion
to UEF; FHRP is the first-hour rating
determined under the EF test procedure,
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 (condensing gas-fired and oilfired) the available data were too limited
to produce reliable regressions for the
full set of parameters. To constrain the
regression so as to generate more
reliable predictions for those smaller
sets of data, the intercepts of the
regressions were assigned a value of
zero, meaning that a water heater with
an FHRP of zero would also have a New
FHR of zero. This assignment is
reasonable because if a hypothetical
water heater were not able to deliver
any water under the EF test procedure,
it also would not be able to deliver
water under the UEF test procedure.
In response to the first-hour rating
mathematical conversion developed in
the NOPR, AHRI argued that the results
are often inconsistent and show no
trend, particularly for the consumer gasfired storage product class in the
medium and high draw patterns. (AHRI,
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Conversion factor
FHR
FHR
FHR
FHR
FHR
FHR
FHR
E:\FR\FM\30AUP2.SGM
=
=
=
=
=
=
=
7.9592 + 0.8752 × FHRP.
25.0680 + 0.6535 × FHRP.
1.0570 × FHRP.
1.1012 × FHRP.
9.2827 + 0.8092 × FHRP.
41.5127 + 0.1989 × FHRP.
¥4.2705 + 0.9947 × FHRP.
30AUP2
59768
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
uniform efficiency descriptor test
procedure. 10 CFR 430, Subpart B,
Appendix E, section 5.4.1. 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.4.c for all consumer
water heater types. Alternatively, DOE
investigated the step regression
approach described in section III.C.2 to
convert EF to UEF. As described in the
April 2015 NOPR, 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 a
conversion with the lowest RMSD
observed. 80 FR 20116, 20132 (April 14,
2015). 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 WHAMregression model are presented in Table
III.30. In light of the additional data
compiled for the SNOPR, the RMSD for
the non-heat pump storage water heater
classes is 0.018 when using a combined
WHAM-regression model, and as noted,
this is the lowest RMSD observed. DOE,
therefore, continues to propose the use
of the combined WHAM-regression
approach to calculate the conversion
factor for all types of consumer storage
water heaters except 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. The resulting
equations for determining the UEF of
consumer storage water heaters are
shown in Table III.29.
For heat pump water heaters, DOE
determined in the April 2015 NOPR
that, although the relevant data can be
obtained through testing (and for the
units tested by DOE were obtained), the
data are not available within the
certification databases to compute the
WHAM estimate for heat pump water
heaters on the market; therefore, a linear
regression equation was developed in
which the UEF is estimated solely based
on the EF. 80 FR 20116, 20132 (April
14, 2015). DOE received no comments
submitting data on this point or
identifying sources from which DOE
could obtain such data. In this SNOPR,
DOE proposes that manufacturers
should apply the conversions to their
test data directly, and then the
converted test values will be used to
rate the water heater model in
accordance with the certification
provisions found in 10 CFR 429.17.
Because both DOE’s data from its testing
and the test data submitted by AHRI
include all of the necessary information
to estimate the efficiency using the
WHAM equation, WHAM and WHAMRegression conversions can be derived
based on the tested values. Under either
of these approaches, manufacturers
would use data from EF tests that is
generally not publicly-available (e.g.,
the recovery efficiency of the heat
pump) along with a WHAM-based
equation to convert to the UEF metric.
The WHAM, regression (modified from
the NOPR proposal as discussed
immediately below), and WHAMRegression conversion approaches result
in RMSD values of 0.219, 0.194, and
0.197, respectively. The regression
approach was modified as discussed
below and has the lowest RMSD value,
and, therefore, DOE continues to
propose to use the regression conversion
approach for converting to UEF for
HPWH.
GE stated that the proposed
conversion for HPWH is inaccurate, and
suggested including drawn volume as
an independent variable in the
regression analysis to improve the
conversion for high-EF heat pump water
heaters. (GE, No. 12 at p. 1) GE also
provided an equation which related EF
and drawn volume to UEF. (GE, No. 12
at p. 4) DOE considered these
suggestions and agrees that the
inclusion of drawn volume as a
regression variable would help improve
the conversion factor, so DOE has
updated the equation appropriately. The
GE equation and the new DOE-derived
conversion factor results in RMSD
values of 0.229 and 0.194, respectively,
which is an improvement over the
previous conversion factor’s RMSD
value for heat pump water heaters,
which is 0.438 (recalculated with new
test data). 80 FR 20116, 20133 (April 14,
2015). Even after considering the large
disparity between EF standards and the
rated EF values for heat pump water
heaters, DOE has nonetheless tentatively
concluded that this relatively high
RMSD would not cause a water heater
to fail to meet the standards based on
UEF. Furthermore, the disparity
between the UEF of heat pump water
heaters and electric resistance water
heaters is large enough that consumers
would still be made aware of the
significant increase in efficiency that
heat pump water heaters provide over
electric resistance water heaters.
In the equations in Table III.29,
UEFWHAM is the conversion factor
calculated using the WHAM analytical
model, described in section III.C.4.c, EF
is the measured energy factor, and DV
is the drawn volume in gallons.
TABLE III.29—PROPOSED CONSUMER STORAGE UEF CONVERSION FACTOR EQUATIONS
Product class
Distinguishing criteria
Consumer Gas-fired Water Heater
mstockstill on DSK3G9T082PROD with PROPOSALS2
Consumer Oil-fired Water Heater ...
Consumer Electric Water Heater ....
Conversion factor *
Non-Condensing, Standard or Low NOX ..................
Non-Condensing, Ultra-Low NOX ..............................
Condensing ................................................................
N/A .............................................................................
Conventional ..............................................................
Tabletop .....................................................................
Heat Pump .................................................................
New
New
New
New
New
New
New
UEF
UEF
UEF
UEF
UEF
UEF
UEF
=
=
=
=
=
=
=
¥0.0002 + 0.9858 × UEFWHAM.
0.0746 + 0.8653 × UEFWHAM.
0.4242 + 0.4641 × UEFWHAM.
¥0.0934 + 1.1144 × UEFWHAM.
0.4774 + 0.4740 × UEFWHAM.
¥0.3305 + 1.3983 × UEFWHAM.
0.1513 + 0.8407 × EF + 0.0043 × DV.
TABLE III.30—CONSUMER STORAGE WATER HEATER CONVERSION FACTOR RESULTS
Tested FHR
(gal)
CS No.
1
2
3
4
Regression
FHR
(gal)
Tested UEF
WHAM UEF
Regression
UEF
WHAMRegression
UEF
104.2
85.0
80.9
86.7
78.0
96.2
73.2
93.3
0.802
0.826
0.714
0.634
0.821
0.865
0.718
0.648
0.805
0.826
0.685
0.611
0.805
0.826
0.708
0.638
.......................................................................................
.......................................................................................
.......................................................................................
.......................................................................................
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59769
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.30—CONSUMER STORAGE WATER HEATER CONVERSION FACTOR RESULTS—Continued
Tested FHR
(gal)
mstockstill on DSK3G9T082PROD with PROPOSALS2
CS No.
Regression
FHR
(gal)
Tested UEF
WHAM UEF
Regression
UEF
WHAMRegression
UEF
64.8
75.7
63.8
87.7
77.8
64.4
70.9
65.1
74.1
94.6
68.1
81.1
108.8
81.1
87.0
64.8
70.6
88.2
84.0
51.5
83.2
97.9
127.4
111.6
39.7
42.9
52.3
46.2
50.0
65.3
59.9
59.8
43.2
73.3
48.5
64.2
68.7
54.8
59.4
77.2
56.8
64.8
51.9
48.0
45.3
56.1
58.9
48.7
68.6
87.1
58.0
86.9
77.3
78.8
75.6
52.8
69.5
75.9
89.5
67.9
70.0
51.9
70.6
68.0
62.5
59.6
78.8
115.0
78.5
97.9
70.4
72.3
78.1
91.3
70.9
59.6
73.5
68.1
69.4
92.8
65.7
86.9
102.5
66.6
69.4
69.7
61.7
85.2
86.6
58.0
82.5
92.5
123.8
115.4
42.8
44.0
54.2
42.3
52.3
55.0
63.3
58.7
40.6
64.8
52.8
60.0
62.8
52.8
61.8
74.6
60.9
58.4
51.7
52.0
49.0
59.9
52.7
54.5
66.8
85.7
52.4
96.8
86.3
84.5
65.0
56.4
67.9
69.2
91.0
66.4
86.0
53.9
73.1
73.5
70.4
56.2
64.1
82.3
81.6
89.4
0.600
0.719
0.669
0.635
0.635
0.605
0.570
0.624
0.654
0.718
0.677
0.676
0.680
0.628
0.641
0.598
0.561
0.662
0.640
0.603
0.617
0.596
0.641
0.528
0.903
0.891
0.937
0.902
0.906
0.909
0.932
0.946
0.902
0.942
0.868
0.931
0.919
0.941
0.926
0.952
0.904
0.901
0.922
0.805
0.859
1.948
2.572
2.071
2.496
2.642
2.540
0.806
0.704
0.729
0.653
0.597
0.595
0.750
0.649
0.597
0.560
0.578
0.651
0.574
0.577
0.596
0.637
0.611
0.711
0.718
0.607
0.732
0.694
0.645
0.640
0.598
0.598
0.649
0.656
0.721
0.679
0.705
0.686
0.643
0.650
0.584
0.586
0.668
0.584
0.623
0.632
0.617
0.659
0.557
0.926
0.905
0.935
0.919
0.912
0.922
0.906
0.943
0.866
0.903
0.891
0.912
0.944
0.906
0.955
0.965
0.930
0.905
0.923
0.812
0.855
2.441
2.215
2.049
2.202
2.401
2.213
0.817
0.710
0.728
0.637
0.615
0.628
0.750
0.667
0.605
0.566
0.592
0.627
0.603
0.600
0.605
0.642
0.622
0.702
0.714
0.624
0.694
0.702
0.608
0.608
0.618
0.618
0.660
0.668
0.695
0.691
0.669
0.651
0.602
0.611
0.600
0.607
0.622
0.559
0.632
0.594
0.582
0.641
0.528
0.922
0.912
0.917
0.919
0.916
0.908
0.898
0.922
0.894
0.895
0.906
0.902
0.923
0.898
0.930
0.930
0.913
0.897
0.909
0.867
0.888
2.478
2.296
2.214
2.305
2.421
2.347
0.804
0.676
0.690
0.601
0.634
0.646
0.710
0.624
0.625
0.590
0.612
0.642
0.623
0.622
0.624
0.603
0.583
0.670
0.682
0.599
0.722
0.684
0.635
0.631
0.589
0.590
0.639
0.647
0.711
0.670
0.694
0.676
0.634
0.641
0.580
0.582
0.652
0.580
0.613
0.622
0.609
0.641
0.528
0.916
0.906
0.921
0.913
0.910
0.914
0.907
0.924
0.888
0.906
0.900
0.910
0.925
0.907
0.930
0.935
0.918
0.906
0.915
0.805
0.865
2.494
2.312
2.177
2.301
2.462
2.310
0.803
0.699
0.718
0.628
0.606
0.619
0.739
0.658
0.596
0.557
0.583
0.618
0.594
0.591
0.596
0.632
0.613
0.692
0.704
5 .......................................................................................
6 .......................................................................................
7 .......................................................................................
8 .......................................................................................
9 .......................................................................................
10 .....................................................................................
11 .....................................................................................
12 .....................................................................................
13 .....................................................................................
14 .....................................................................................
15 .....................................................................................
16 .....................................................................................
17 .....................................................................................
18 .....................................................................................
19 .....................................................................................
20 .....................................................................................
21 .....................................................................................
22 .....................................................................................
23 .....................................................................................
24 .....................................................................................
25 .....................................................................................
26 .....................................................................................
27 .....................................................................................
28 .....................................................................................
29 .....................................................................................
30 .....................................................................................
31 .....................................................................................
32 .....................................................................................
33 .....................................................................................
34 .....................................................................................
35 .....................................................................................
36 .....................................................................................
37 .....................................................................................
38 .....................................................................................
39 .....................................................................................
40 .....................................................................................
41 .....................................................................................
42 .....................................................................................
43 .....................................................................................
44 .....................................................................................
45 .....................................................................................
46 .....................................................................................
47 .....................................................................................
48 .....................................................................................
49 .....................................................................................
50 .....................................................................................
51 .....................................................................................
52 .....................................................................................
53 .....................................................................................
54 .....................................................................................
55 .....................................................................................
56 .....................................................................................
57 .....................................................................................
58 .....................................................................................
59 .....................................................................................
60 .....................................................................................
61 .....................................................................................
62 .....................................................................................
63 .....................................................................................
64 .....................................................................................
65 .....................................................................................
66 .....................................................................................
67 .....................................................................................
68 .....................................................................................
69 .....................................................................................
70 .....................................................................................
71 .....................................................................................
72 .....................................................................................
73 .....................................................................................
74 .....................................................................................
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59770
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.30—CONSUMER STORAGE WATER HEATER CONVERSION FACTOR RESULTS—Continued
Tested FHR
(gal)
mstockstill on DSK3G9T082PROD with PROPOSALS2
CS No.
Regression
FHR
(gal)
Tested UEF
WHAM UEF
Regression
UEF
WHAMRegression
UEF
80.7
69.6
70.8
71.5
87.2
81.7
50.6
81.7
73.6
73.0
67.0
83.8
84.4
89.3
48.2
50.7
80.8
65.1
71.8
59.9
74.6
75.9
55.0
57.8
60.4
72.0
53.7
68.6
82.3
130.2
67.7
113.0
64.9
113.0
68.6
68.6
81.5
66.0
67.3
81.3
80.1
82.9
78.5
114.4
90.7
87.9
65.1
65.8
82.0
76.5
78.6
77.4
104.9
75.9
86.5
79.7
61.6
91.6
61.1
73.9
75.1
68.4
67.7
66.9
73.5
68.8
85.8
68.1
84.7
85.0
85.3
77.5
76.2
73.6
90.8
83.5
57.9
84.5
73.9
80.6
81.0
67.2
74.1
95.6
53.3
57.1
84.3
67.3
76.4
60.4
81.7
80.7
63.1
54.2
53.7
75.1
59.6
72.5
86.0
98.4
78.9
95.5
65.5
95.5
70.8
68.6
87.3
69.9
68.7
81.1
84.9
83.7
70.7
106.4
88.9
68.7
70.3
75.5
84.5
83.8
88.2
68.0
106.0
82.5
88.8
84.0
69.0
87.0
66.0
79.6
73.7
74.1
62.3
72.7
72.1
72.0
81.3
72.0
69.6
69.5
0.656
0.580
0.593
0.558
0.613
0.611
0.598
0.622
0.588
0.580
0.640
0.654
0.644
0.646
0.603
0.535
0.614
0.620
0.557
0.588
0.556
0.669
0.607
0.623
0.596
0.552
0.556
0.620
0.652
0.646
0.621
0.654
0.571
0.654
0.633
0.646
0.713
0.626
0.662
0.689
0.685
0.646
0.725
0.693
0.704
0.699
0.576
0.658
0.639
0.636
0.636
0.689
0.690
0.674
0.676
0.691
0.592
0.613
0.602
0.592
0.647
0.529
0.597
0.529
0.580
0.648
0.715
0.633
0.699
0.700
0.645
0.584
0.574
0.612
0.635
0.614
0.625
0.636
0.611
0.589
0.589
0.649
0.629
0.662
0.606
0.544
0.642
0.634
0.593
0.586
0.564
0.675
0.602
0.626
0.606
0.592
0.574
0.613
0.658
0.648
0.632
0.666
0.580
0.666
0.672
0.659
0.726
0.634
0.676
0.680
0.666
0.696
0.727
0.673
0.718
0.695
0.593
0.664
0.641
0.632
0.653
0.706
0.714
0.695
0.705
0.711
0.592
0.658
0.605
0.611
0.658
0.552
0.607
0.554
0.581
0.591
0.704
0.643
0.710
0.711
0.606
0.609
0.598
0.631
0.599
0.579
0.645
0.594
0.632
0.611
0.611
0.611
0.590
0.618
0.674
0.632
0.606
0.653
0.615
0.607
0.588
0.632
0.622
0.644
0.629
0.613
0.598
0.632
0.619
0.602
0.650
0.623
0.603
0.623
0.682
0.670
0.692
0.648
0.684
0.649
0.638
0.662
0.690
0.640
0.683
0.663
0.614
0.674
0.607
0.592
0.612
0.674
0.677
0.657
0.668
0.676
0.610
0.618
0.618
0.625
0.616
0.580
0.620
0.582
0.601
0.607
0.654
0.644
0.657
0.660
0.636
0.576
0.565
0.603
0.626
0.605
0.616
0.627
0.602
0.580
0.580
0.639
0.620
0.653
0.598
0.536
0.632
0.625
0.584
0.577
0.555
0.665
0.593
0.617
0.597
0.583
0.566
0.604
0.649
0.639
0.623
0.656
0.571
0.656
0.662
0.649
0.715
0.625
0.666
0.670
0.656
0.686
0.716
0.663
0.707
0.685
0.584
0.655
0.631
0.623
0.644
0.696
0.703
0.685
0.695
0.701
0.587
0.644
0.598
0.604
0.644
0.552
0.600
0.554
0.577
0.586
0.683
0.631
0.689
0.690
75 .....................................................................................
76 .....................................................................................
77 .....................................................................................
78 .....................................................................................
79 .....................................................................................
80 .....................................................................................
81 .....................................................................................
82 .....................................................................................
83 .....................................................................................
84 .....................................................................................
85 .....................................................................................
86 .....................................................................................
87 .....................................................................................
88 .....................................................................................
89 .....................................................................................
90 .....................................................................................
91 .....................................................................................
92 .....................................................................................
93 .....................................................................................
94 .....................................................................................
95 .....................................................................................
96 .....................................................................................
97 .....................................................................................
98 .....................................................................................
99 .....................................................................................
100 ...................................................................................
101 ...................................................................................
102 ...................................................................................
103 ...................................................................................
104 ...................................................................................
105 ...................................................................................
106 ...................................................................................
107 ...................................................................................
108 ...................................................................................
109 ...................................................................................
110 ...................................................................................
111 ...................................................................................
112 ...................................................................................
113 ...................................................................................
114 ...................................................................................
115 ...................................................................................
116 ...................................................................................
117 ...................................................................................
118 ...................................................................................
119 ...................................................................................
120 ...................................................................................
121 ...................................................................................
122 ...................................................................................
123 ...................................................................................
124 ...................................................................................
125 ...................................................................................
126 ...................................................................................
127 ...................................................................................
128 ...................................................................................
129 ...................................................................................
130 ...................................................................................
131 ...................................................................................
132 ...................................................................................
133 ...................................................................................
134 ...................................................................................
135 ...................................................................................
136 ...................................................................................
137 ...................................................................................
138 ...................................................................................
139 ...................................................................................
140 ...................................................................................
141 ...................................................................................
142 ...................................................................................
143 ...................................................................................
144 ...................................................................................
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TABLE III.30—CONSUMER STORAGE WATER HEATER CONVERSION FACTOR RESULTS—Continued
Tested FHR
(gal)
CS No.
mstockstill on DSK3G9T082PROD with PROPOSALS2
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
Regression
FHR
(gal)
Tested UEF
WHAM UEF
Regression
UEF
WHAMRegression
UEF
66.5
92.6
74.0
51.2
45.9
57.4
63.3
54.3
38.6
41.4
57.3
49.1
66.4
64.2
60.7
51.5
55.0
59.4
36.5
52.0
61.0
48.0
60.1
55.6
42.1
51.3
61.1
57.0
58.3
61.0
58.3
61.1
94.6
64.1
78.4
100.1
52.3
66.1
89.6
74.8
89.4
82.1
88.7
77.4
52.7
43.4
49.5
60.7
57.3
42.5
44.6
51.8
46.8
74.4
63.0
60.8
53.1
57.0
61.8
45.9
53.8
56.2
48.1
61.3
52.9
47.8
55.8
66.7
57.1
57.3
62.1
50.6
59.9
93.6
64.7
70.2
96.9
66.7
64.5
91.2
77.0
91.0
0.560
0.688
0.682
0.942
0.897
0.922
0.911
0.920
0.897
0.890
0.938
0.898
0.933
0.912
0.910
0.888
0.920
0.926
0.878
0.950
0.930
0.870
0.919
0.929
0.911
0.915
0.907
0.931
0.922
0.910
0.873
2.470
2.439
3.270
2.424
2.137
2.219
3.140
3.330
2.270
3.186
0.666
0.702
0.690
0.957
0.924
0.938
0.950
0.914
0.907
0.865
0.927
0.912
0.925
0.932
0.922
0.903
0.945
0.957
0.949
0.945
0.933
0.896
0.932
0.924
0.917
0.934
0.929
0.934
0.941
0.933
0.856
2.394
2.715
3.223
2.344
2.012
2.266
3.173
3.436
2.193
3.316
0.661
0.651
0.682
0.932
0.921
0.919
0.926
0.903
0.913
0.893
0.912
0.916
0.910
0.915
0.908
0.896
0.923
0.931
0.933
0.923
0.916
0.908
0.915
0.909
0.918
0.916
0.913
0.916
0.921
0.916
0.864
2.448
2.713
3.144
2.444
2.170
2.314
3.103
3.295
2.272
3.208
0.651
0.682
0.672
0.931
0.915
0.922
0.927
0.910
0.907
0.887
0.917
0.910
0.916
0.919
0.914
0.905
0.925
0.931
0.927
0.925
0.920
0.902
0.919
0.915
0.912
0.920
0.918
0.920
0.924
0.920
0.867
2.456
2.716
3.127
2.416
2.147
2.353
3.087
3.299
2.293
3.202
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
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...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
In response to the UEF conversion for
the NOPR, AHRI commented that units
tested with the very small, low, and
medium draw patterns will likely have
UEF values less than EF, while units
tested with the high draw pattern will
likely have UEF values greater than EF
due to standby times. (AHRI, No. 13 at
p. 6) Were standby time the only factor
affecting the difference between EF and
UEF, AHRI’s argument would have
some merit. However, in 9 percent of
the consumer storage tests, a pattern
opposite from what AHRI suggested was
observed. This empirical observation
indicates that AHRI’s assumptions are
not wholly correct. AHRI also
commented that for most of the electric
resistance water heater samples, the
calculated conversion factor using the
WHAM-regression UEF model does not
track with the tested UEF (i.e., some
values are higher than the test result,
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21:44 Aug 29, 2016
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others lower). (AHRI, No. 13 at p. 5)
Further, AHRI stated that for electric
resistance models, the measured UEF is
consistently lower than the measured
EF, although the amount of difference
varies. AHRI stated that the data for
units in the low-usage bin indicate a
very significant miscalculation of the
effect of the UEF test procedure on those
models, and that the converted UEF
value in most cases is higher than the
measured UEF value, which suggests
that the converted UEF formula is
underestimating the effect of the
uniform energy descriptor test
procedure. (AHRI, No. 6 at p. 2) AHRI
also pointed out that the measured UEFs
for low-input (<10,000 Btu/h) heat
pump water heaters were higher than
the measured EF, and for the one
higher-input unit, the measured UEF
was lower than the measured EF.
However, with one exception, the
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Sfmt 4702
calculated UEF using the proposed
conversion exhibited the opposite
results. (AHRI, No. 13 at p. 5)
Rheem commented that several
electric storage water heaters (both heat
pump and non-heat pump) in the
medium draw pattern show an
increased UEF rating as compared to EF
in DOE’s test results. However, Rheem
asserted that since the UEF test method
has more standby time than the EF test
method, the resulting UEF would be
expected to decrease, and stated that it
has observed a consistent decrease in
the UEF of electric storage water heaters
in the medium draw bin, as compared
to the EF rating. (Rheem, No. 11 at pp.
4–5)
With respect to AHRI’s observation
that the WHAM-regression model does
not perfectly reproduce the UEF
measurements of every model, DOE
notes that, as discussed previously, a
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simple conversion formula will not
reproduce identically the results that
one would measure by applying the EF
and UEF test methods for each and
every unit. Yet DOE’s task, as required
by the statute, is to prepare a set of
conversion formulas. DOE understands
the statute, by implication, to
contemplate that for any given unit,
there may be some difference between
the formula output and the comparative
EF and UEF test results.
AHRI’s observation that the measured
UEF is consistently less than the
measured EF for electric resistance
storage water heaters in the low-draw
bin generally still holds for the
conversion factor proposed in this
SNOPR, and as stated above, this
behavior is expected. Of the 13 lowdraw-pattern units for which test data
are available for the SNOPR, the
conversion factor predicts a UEF higher
than the tested UEF in 9 cases, equal to
the tested UEF in 3 cases, and lower
than the predicted UEF in 1 case. DOE
reasons that this result is due to the
large number of medium-draw-pattern
units used to derive the conversion
factor. Similarly, the converted UEF for
the one high-draw-pattern electric
storage water heater is below the tested
UEF value. Because the regression
analysis is conducted across all draw
patterns for a given class, the result may
more heavily favor draw patterns with
more data present. DOE believes that
proposing a separate conversion for
each draw pattern would eliminate this
issue. However, if DOE were to propose
conversions for each draw pattern, the
number of UEF conversion equations
would increase from 26 to 104. DOE
believes a separate conversion factor for
each draw pattern would add a
significant amount of complexity to the
conversion factor that would not be
justified by the slight skew toward draw
patterns with more units (and therefore
more test data). DOE also notes that the
converted values are not always higher
than the tested values under the
conversions proposed in this SNOPR
indicating that this effect does not occur
consistently for all units. Further,
Rheem’s observation that the consumer
electric storage medium-draw-pattern
testing yields UEFs greater than
corresponding EF values for some units
appears to occur in both the DOE and
AHRI data sets, suggesting that standby
time is not the only variable to consider
when comparing results from the two
test procedures. AHRI’s observation
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about the effect of the input rate on the
difference between measured UEF and
EF in the heat pump water heater tests
based on the NOPR data appears not to
hold with the addition of the AHRI test
data.
For gas-fired storage water heaters,
AHRI commented that in the mediumusage bin, the measured UEF is
consistently lower than the measured
EF, but there is no consistent pattern in
the difference between the measured
UEF and the converted UEF. (AHRI, No.
6 at p. 2) For gas-fired storage water
heaters in the high-usage bin, AHRI
stated that the measured UEF is
consistently higher than the measured
EF, and there is no consistent
relationship between the converted UEF
value and the measured UEF value.
(AHRI, No. 6 at p. 2) AHRI and Rheem
commented that, for ultra-low NOX gasfired water heaters, the measured UEF
for the short models was less than the
measured EF and the measured UEF for
the tall models was greater than the
measured EF, but that the calculated
UEF using the conversion exhibits the
opposite relationship. AHRI and Rheem
suggested the trend requires further test
data for such units. (AHRI, No. 13 at p.
5; Rheem, No. 11 at p. 7)
In general, measured UEF values in
the very small, low, or medium draw
patterns will usually be lower than their
respective measured EF values, and
measured UEF values in the high draw
patterns will usually be higher than
their respective measured EF value.
Also, this outcome (i.e., converted
results both higher and lower than the
measured results for a category of water
heater) is what one should expect if the
conversion is, overall, a reasonable
representation of efficiency. Therefore,
AHRI’s comments about the consumer
gas-fired storage test and conversion
data for the medium and high draw
pattern reflect the expected result of the
conversion.
AHRI and Rheem’s comment about
the ultra-low NOX short comparison of
measured EF and UEF seems to still
hold with the addition of the AHRI test
data; that is, the measured UEF for 4 of
the 7 short models was less than the
measured EF, equal to the measured EF
for 1 unit, and greater than the
measured EF for 2 units. The measured
UEF for the tall models was greater than
the measured EF in 8 of the 17 units,
and less than the measured EF in the
other 9 units. When examining the
converted UEF values, 5 short units
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have converted UEFs less than the
measured EF and 2 that are greater,
while the same relationship exists in the
converted UEF data as was observed in
the measured UEF data for the tall units.
Further, deriving separate conversions
for short and tall ultra-low NOX water
heaters decreases the RMSD value by
less than 0.0015, which seems like a
negligible improvement when weighed
against the added complexity of an
additional conversion factor. DOE also
notes that it is not aware of an industryaccepted consensus for determining
whether a water heater is ‘‘tall’’ or
‘‘short,’’ which makes implementing a
conversion based on this factor difficult.
b. Consumer Instantaneous Water
Heaters
i. Test Results
DOE has tested 22 consumer
instantaneous water heaters to both the
EF and UEF test procedures, and AHRI
has supplied test data for 36 additional
units of this water heater type.13 14 Table
III.31 presents the test data used to
derive the proposed consumer
instantaneous water heater conversion
factors. DOE notes that 1 of the 53 gasfired instantaneous water heaters that
were tested is not rated to meet the
current energy conservation standards
(compliance required April 16, 2015).
However, as discussed in section
III.E.2.a.i, DOE believes that these data
points are valid for the purpose of
determining the mathematical
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.32 shows the
water heater attributes by unit described
in section III.E.1.
13 The AHRI submitted test data point CIS–5 was
not used because the measured input rate was
greater than the maximum allowable deviation from
the rated input rate of 2 percent, resulting in an
invalid test.
14 If multiple tests were conducted on either the
same unit or same basic model of a water heater,
the results were averaged to produce the values
reported in this SNOPR. In one instance within the
AHRI submitted data for consumer instantaneous
water heaters, three tests were conducted, where
two tests were conducted on the same unit and
another test was conducted on a unit of the same
basic model. The two tests of the same unit were
averaged and this value was then averaged with the
results of the test of the unit of the same basic
model.
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TABLE III.31—CONSUMER INSTANTANEOUS WATER HEATER TEST DATA
CI No.
AHRI No.
1 ............
2 ............
3 ............
4 ............
5 ............
6 ............
7 ............
8 ............
9 ............
10 ..........
11 ..........
12 ..........
13 ..........
14 ..........
15 ..........
16 ..........
17 ..........
18 ..........
19 ..........
20 ..........
21 ..........
22 ..........
23 ..........
24 ..........
25 ..........
26 ..........
27 ..........
28 ..........
29 ..........
30 ..........
31 ..........
32 ..........
33 ..........
34 ..........
35 ..........
36 ..........
37 ..........
38 ..........
39 ..........
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. ..........
N/A. ..........
N/A. ..........
N/A. ..........
N/A. ..........
1–94 .........
1–92, 93 ...
CIS–1 .......
CIS–2 .......
CIS–3 .......
CIS–4 .......
CIS–6 .......
CIS–9 .......
1–85 .........
1–86 .........
1–87 .........
1–88 .........
1–89 .........
1–90 .........
1–100 .......
1–101 .......
1–77, 83,
84.
1–97 .........
CIS–7 .......
CIS–8 .......
2–9 ...........
2–10 .........
2–11 .........
2–12 .........
2–13 .........
1–78 .........
1–79 .........
1–80 .........
1–81 .........
1–82 .........
1–91 .........
1–98 .........
1–99 .........
1–102 .......
1–103 .......
1–104 .......
mstockstill on DSK3G9T082PROD with PROPOSALS2
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
TABLE
NEOUS
Input rate
(Btu/h)
Type
1 .................
2 .................
3 .................
VerDate Sep<11>2014
NOX emission
level
Low ...............
Low ...............
Low ...............
21:44 Aug 29, 2016
Updated max
GPM
Prior recovery
efficiency (%)
EF
UEF
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Electric
Electric
Electric
Electric
Electric
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
142,500
190,800
120,900
141,100
175,800
178,500
199,000
179,900
180,400
199,200
151,700
199,800
197,200
154,100
201,300
117,800
148,800
33,100
7,800
19,800
26,000
31,000
187,800
187,900
137,700
198,300
151,600
202,100
148,400
196,000
202,300
200,400
186,500
195,700
142,900
188,500
197,400
141,800
151,600
3.0
4.2
2.7
3.1
3.7
4.1
4.6
4.0
3.9
4.3
3.4
4.8
5.2
4.0
4.9
2.5
3.3
0.9
0.2
0.5
0.7
0.8
4.0
4.0
3.1
4.3
3.4
4.4
3.2
4.4
4.4
4.4
4.3
4.3
3.2
4.0
4.3
3.1
3.5
3.4
4.8
3.1
3.6
4.3
4.7
4.9
4.6
4.6
5.1
3.9
4.1
5.8
4.5
5.7
2.9
3.7
1.0
0.2
0.6
0.8
0.9
4.5
4.4
3.6
5.0
3.9
5.1
3.8
5.0
5.1
5.1
4.8
5.0
3.6
4.6
5.5
3.6
4.0
80.9
81.4
82.6
81.7
84.5
83.8
86.9
80.3
85.1
75.0
85.4
93.8
96.7
91.6
88.0
77.7
82.6
101.7
101.2
102.2
102.0
101.5
80.2
83.0
83.6
85.0
84.8
91.7
83.4
88.7
86.3
86.3
83.9
80.8
84.6
85.3
83.8
83.1
87.2
0.801
0.813
0.828
0.812
0.838
0.838
0.872
0.803
0.852
0.743
0.853
0.932
0.966
0.913
0.851
0.776
0.823
1.018
1.013
1.020
1.019
1.017
0.794
0.816
0.832
0.845
0.845
0.916
0.836
0.882
0.864
0.859
0.838
0.809
0.842
0.847
0.826
0.831
0.874
0.800
0.820
0.809
0.823
0.833
0.830
0.841
0.840
0.832
0.799
0.813
0.939
0.958
0.925
0.884
0.757
0.811
1.010
0.983
1.006
1.007
0.982
0.809
0.815
0.812
0.843
0.806
0.869
0.805
0.869
0.817
0.826
0.816
0.640
0.792
0.824
0.818
0.816
0.851
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
Gas
198,700
195,100
150,100
203,200
177,200
203,500
195,100
150,100
155,000
159,400
176,900
176,700
183,200
120,500
182,100
197,000
122,300
183,000
121,100
4.8
5.1
3.7
4.8
4.4
4.9
4.9
3.7
3.8
4.0
4.3
4.3
4.5
3.1
4.1
5.0
2.9
4.4
2.7
5.5
5.6
4.3
5.5
5.0
5.4
5.6
4.3
4.4
4.5
4.9
4.9
5.2
3.5
5.1
5.0
3.4
4.8
3.2
98.8
97.8
95.3
98.2
96.8
98.1
96.7
95.3
97.4
96.1
96.3
97.9
96.5
94.1
90.8
95.3
91.4
92.1
91.5
0.975
0.978
0.951
0.974
0.951
0.974
0.965
0.951
0.964
0.959
0.947
0.966
0.957
0.937
0.908
0.935
0.915
0.914
0.910
0.952
0.922
0.918
0.943
0.925
0.945
0.922
0.918
0.928
0.921
0.920
0.933
0.919
0.910
0.911
0.924
0.883
0.901
0.864
III.32—CONSUMER INSTANTAWATER HEATER ATTRIBUTES
CI No.
Prior max
GPM
TABLE III.32—CONSUMER INSTANTANEOUS
WATER
HEATER
ATTRIBUTES—Continued
Condensing
CI No.
No.
No.
No.
Jkt 238001
NOX emission
level
4 .................
5 .................
Low ...............
Ultra-Low ......
PO 00000
Frm 00039
Fmt 4701
Condensing
No.
No.
Sfmt 4702
TABLE III.32—CONSUMER INSTANTANEOUS
WATER
HEATER
ATTRIBUTES—Continued
CI No.
NOX emission
level
6 .................
7 .................
Ultra-Low ......
Ultra-Low ......
E:\FR\FM\30AUP2.SGM
30AUP2
Condensing
No.
No.
59774
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.32—CONSUMER INSTANTANEOUS
WATER
HEATER
ATTRIBUTES—Continued
CI No.
NOX emission
level
8 .................
9 .................
10 ...............
11 ...............
12 ...............
13 ...............
14 ...............
15 ...............
16 ...............
17 ...............
18 ...............
19 ...............
20 ...............
21 ...............
22 ...............
23 ...............
24 ...............
25 ...............
26 ...............
27 ...............
28 ...............
29 ...............
30 ...............
31 ...............
32 ...............
33 ...............
34 ...............
35 ...............
36 ...............
37 ...............
38 ...............
39 ...............
40 ...............
41 ...............
42 ...............
43 ...............
44 ...............
45 ...............
46 ...............
47 ...............
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Low ...............
Low ...............
N/A. ...............
N/A. ...............
N/A. ...............
N/A. ...............
N/A. ...............
Low ...............
Low ...............
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Low ...............
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
Ultra-Low ......
TABLE III.32—CONSUMER INSTANTA- approaches are 0.24, 0.23, and 0.23,
NEOUS
WATER
HEATER
AT- respectively. For the UEF conversions,
the three approaches have RMSD of
TRIBUTES—Continued
CI No.
...............
...............
...............
...............
...............
...............
...............
...............
...............
...............
...............
Condensing
48
49
50
51
52
53
54
55
56
57
58
No.
No.
No.
No.
Yes.
Yes.
Yes.
Yes.
No.
No.
N/A.
N/A.
N/A.
N/A.
N/A.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
NOX emission
level
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
Ultra-Low
......
......
......
......
......
......
......
......
......
......
......
Condensing
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
ii. Conversion Factor Results
As stated in section III.C.4.a, DOE
developed an analytical model that DOE
proposes to use to convert the prior
measured values of maximum GPM
rating for consumer instantaneous water
heaters to measured values under the
uniform efficiency descriptor test
procedure. DOE also developed an
analytical method to estimate the
change in prior measured values of
energy factor under the energy factor
test procedure to measured values of
uniform energy factor 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.34. For the maximum GPM
conversions, the RMSD for the three
0.035, 0.028, and 0.027, respectively.
DOE has decided to continue to propose
to use the analytical model approach to
calculate the consumer instantaneous
maximum GPM conversion factor owing
to the fact that the analytical model
approach predicts the resultant data
very closely and that it will broadly
apply to those units not tested. DOE has
also decided to continue to propose to
use the combined analytical modelregression approach to convert from EF
to UEF since the RMSDs are the lowest
observed, and it has concluded that the
use of the model and regression will
capture key effects that may not be
captured with either approach by itself.
The resulting conversion factors for both
maximum GPM and UEF are shown in
Table III.33. In the equations in Table
III.33, Max GPMP is the maximum GPM
based on the prior DOE test procedure
and UEFmodel is the predicted UEF
determined using the analytical model,
described in section III.C.4.c.
TABLE III.33—PROPOSED CONSUMER
INSTANTANEOUS CONVERSION FACTOR EQUATIONS
Product class
All Consumer
Instantaneous.
Gas-fired Instantaneous.
Electric Instantaneous.
Conversion factor
New Max GPM = 1.1461 x
Max GPMP
New UEF = 0.1006 + 0.8622
× UEFmodel
New UEF = 0.9847 ×
UEFmodel
TABLE III.34—CONSUMER INSTANTANEOUS CONVERSION FACTOR RESULTS
mstockstill on DSK3G9T082PROD with PROPOSALS2
CI No.
Tested max
GPM
1 .......................................
2 .......................................
3 .......................................
4 .......................................
5 .......................................
6 .......................................
7 .......................................
8 .......................................
9 .......................................
10 .....................................
11 .....................................
12 .....................................
13 .....................................
14 .....................................
15 .....................................
16 .....................................
17 .....................................
18 .....................................
19 .....................................
20 .....................................
21 .....................................
VerDate Sep<11>2014
21:44 Aug 29, 2016
3.44
4.81
3.11
3.61
4.31
4.71
4.87
4.59
4.61
5.07
3.89
4.11
5.81
4.48
5.70
2.88
3.67
0.99
0.24
0.60
0.80
Jkt 238001
Analytical
max GPM
Regression
max GPM
Combined
AnalyticalRegression
Max GPM
Tested UEF
3.49
4.80
3.21
3.64
4.22
4.64
5.18
4.57
4.48
4.86
3.90
5.37
5.77
4.53
5.48
3.01
3.79
1.00
0.24
0.60
0.78
3.49
4.80
3.21
3.64
4.22
4.64
5.18
4.57
4.48
4.86
3.90
5.37
5.77
4.53
5.48
3.01
3.79
1.00
0.24
0.60
0.78
0.800
0.820
0.809
0.823
0.833
0.830
0.841
0.840
0.832
0.799
0.813
0.939
0.958
0.925
0.884
0.757
0.811
1.010
0.983
1.006
1.007
3.39
4.85
3.09
3.57
4.21
4.68
5.29
4.60
4.50
4.93
3.85
5.50
5.94
4.56
5.62
2.85
3.73
1.00
0.24
0.59
0.78
PO 00000
Frm 00040
Fmt 4701
Sfmt 4702
E:\FR\FM\30AUP2.SGM
Analytical
UEF
0.804
0.810
0.820
0.811
0.841
0.834
0.865
0.799
0.847
0.747
0.847
0.933
0.962
0.912
0.876
0.772
0.821
1.013
1.008
1.018
1.016
30AUP2
Regression
UEF
Combined
AnalyticalRegression
UEF
0.791
0.802
0.814
0.801
0.823
0.823
0.852
0.793
0.835
0.741
0.836
0.904
0.934
0.888
0.834
0.770
0.810
1.000
0.981
1.007
1.003
0.794
0.799
0.808
0.800
0.825
0.820
0.846
0.790
0.831
0.745
0.831
0.905
0.930
0.887
0.856
0.766
0.808
0.997
0.993
1.003
1.001
59775
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.34—CONSUMER INSTANTANEOUS CONVERSION FACTOR RESULTS—Continued
CI No.
mstockstill on DSK3G9T082PROD with PROPOSALS2
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Tested max
GPM
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
.....................................
Analytical
max GPM
0.93
4.50
4.40
3.56
4.95
3.94
5.10
3.80
5.05
5.14
5.07
4.84
4.96
3.63
4.57
5.52
3.62
4.00
5.54
5.60
4.30
5.50
5.00
5.40
5.60
4.30
4.36
4.52
4.94
4.92
5.18
3.50
5.10
5.05
3.37
4.80
3.20
21:44 Aug 29, 2016
Jkt 238001
Combined
AnalyticalRegression
Max GPM
Tested UEF
0.94
4.57
4.54
3.63
4.90
3.97
4.92
3.73
4.91
4.98
4.93
4.85
4.86
3.71
4.59
4.86
3.58
4.00
5.34
5.68
4.25
5.37
4.96
5.48
5.48
4.25
4.34
4.51
4.85
4.84
5.11
3.62
4.70
5.59
3.41
4.96
3.22
0.94
4.57
4.54
3.63
4.90
3.97
4.92
3.73
4.91
4.98
4.93
4.85
4.86
3.71
4.59
4.86
3.58
4.00
5.34
5.68
4.25
5.37
4.96
5.48
5.48
4.25
4.34
4.51
4.85
4.84
5.11
3.62
4.70
5.59
3.41
4.96
3.22
0.982
0.809
0.815
0.812
0.843
0.806
0.869
0.805
0.869
0.817
0.826
0.816
0.640
0.792
0.824
0.818
0.816
0.851
0.952
0.922
0.918
0.943
0.925
0.945
0.922
0.918
0.928
0.921
0.920
0.933
0.919
0.910
0.911
0.924
0.883
0.901
0.864
0.94
4.61
4.57
3.55
4.97
3.93
5.00
3.67
4.99
5.06
5.01
4.92
4.93
3.64
4.63
4.93
3.50
3.96
5.47
5.85
4.24
5.50
5.04
5.62
5.62
4.24
4.34
4.54
4.92
4.91
5.20
3.54
4.74
5.74
3.30
5.04
3.09
In response to the April 2015 NOPR,
AHRI commented that for gas-fired
instantaneous water heaters tested by
DOE, most condensing units had
measured UEFs that were greater than
the EF, but the calculated UEF using the
mathematical conversion for these units
in all cases was less than the tested
UEF. (AHRI, No. 13 at p. 6) NEEA
commented that the UEF rating
comparison results are so scattered as to
strongly suggest that there are factors,
which differ from one water heater to
another, missing from the current
analytical approach, or that one or more
of DOE’s assumptions or
approximations used in the analytical
approach are not valid for every water
heater. NEEA suggested that a likely
source of error may be in the methods
used to estimate the amount of energy
absorbed by the water heater in any
given firing cycle, or the related
estimates of the impact of the time
between firing cycles on this factor.
NEEA also commented that the
VerDate Sep<11>2014
Regression
max GPM
conversion for gas-fired instantaneous
water heaters consistently underrates
the UEF of condensing water heaters
and seems unable to predict reliably the
measured UEF of any non-condensing
models. (NEEA, No. 15 at p. 6)
In response, DOE notes that the
relationship between measured UEF and
EF is not a result of the conversion, but
rather how water heaters are performing
when tested to the UEF test procedure.
In the set of data used for this
rulemaking, DOE observes that 19 of the
23 condensing units have a measured
UEF less than the measured EF. AHRI
and NEEA commented that the
conversion for condensing gas-fired
instantaneous water heaters underrates
the UEF. DOE notes that with the new
test data and conversion factors, 7 of the
condensing units have converted UEFs
greater than the measured, 9 are less
than, and 7 are equal to, after rounding
to the second decimal place, suggesting
that the proposed conversion factor
contained in this SNOPR is overall, a
PO 00000
Frm 00041
Fmt 4701
Sfmt 4702
Analytical
UEF
1.011
0.798
0.826
0.830
0.846
0.842
0.913
0.828
0.883
0.859
0.859
0.835
0.804
0.840
0.849
0.834
0.825
0.868
0.983
0.973
0.948
0.977
0.963
0.976
0.962
0.948
0.969
0.956
0.958
0.974
0.960
0.934
0.904
0.948
0.907
0.917
0.908
Regression
UEF
Combined
AnalyticalRegression
UEF
0.997
0.785
0.804
0.818
0.829
0.829
0.890
0.821
0.861
0.845
0.841
0.823
0.798
0.827
0.831
0.813
0.817
0.855
0.941
0.944
0.921
0.941
0.921
0.941
0.933
0.921
0.932
0.928
0.917
0.934
0.926
0.909
0.884
0.907
0.890
0.889
0.885
0.996
0.789
0.813
0.817
0.830
0.827
0.888
0.814
0.862
0.841
0.841
0.821
0.794
0.825
0.833
0.820
0.812
0.849
0.948
0.939
0.918
0.943
0.931
0.942
0.930
0.918
0.936
0.925
0.926
0.940
0.928
0.906
0.880
0.918
0.882
0.891
0.883
more accurate fit to the test data than
the conversion factor proposed in the
NOPR. Further, the RMSD values for the
NOPR and SNOPR conversions for the
current set of condensing units are 0.063
and 0.017, respectively. These results
indicate that the SNOPR conversion
factors are better predictors of actual
performance. Regarding NEEA’s
statement that the conversion is unable
to predict reliably the measured UEF of
non-condensing models, DOE notes that
the RMSD value is 0.034 when applied
for just non-condensing units, as
compared to the RMSD value of 0.017
when applied to just condensing units,
which indicates that the conversion
equation for gas-fired instantaneous
water heaters does fit the noncondensing data points almost as well
as it fits the condensing data points.
However, DOE notes that the new
conversion equation for non-condensing
gas-fired instantaneous water heaters
produced converted UEF values above
the measured UEF values for 11 units,
E:\FR\FM\30AUP2.SGM
30AUP2
59776
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
below the measured UEF values for 11
units, and equal to for 8 units, when
rounded to the second decimal place,
suggesting the conversion is
representing the non-condensing
category as well as can be expected,
given the variance in the noncondensing test data, and is not skewed
toward over- or under-predicting the
UEF of these units. Further, when
separate conversion equations are
derived for condensing and noncondensing gas-fired instantaneous
water heaters, the RMSD values for noncondensing and condensing
instantaneous water heaters only
improve by 0.003 and 0.001,
respectively. DOE has tentatively
determined that this improvement is
negligible when weighed against the
added complexity of an additional
conversion factor. As stated in section
III.E.1, DOE tentatively considers a
change in RMSD to be negligible if it is
less than one unit (0.01 for EF and UEF,
0.1 for maximum GPM, and 1.0 for firsthour rating). In this case, 0.003 and
0.001 are less than 0.01 and would be
unlikely to have a noticeable effect
when UEF is rounded to the nearest
0.01 per the reporting requirements in
10 CFR 429.17. NEEA’s suggestions
about improving the instantaneous
analytical conversion were previously
discussed in section III.C.4.c of this
notice.
c. Residential-Duty Commercial Storage
Water Heaters
i. Test Results
DOE has tested 8 residential-duty
commercial storage water heaters to
both the thermal efficiency and standby
loss and UEF test procedures, and AHRI
has supplied test data for 12 additional
units of this kind of water heater.15
Table III.35 below presents the test data
used to derive the residential-duty
commercial storage water heater
conversion factors. Table III.36 shows
the water heater attributes by unit
described in section III.E.1.
TABLE III.35—RESIDENTIAL-DUTY COMMERCIAL WATER HEATER TEST DATA
Storage
volume
(gal)
Input
rate
(Btu/h)
Thermal
efficiency
(%)
Standby
loss
(Btu/h)
Updated
FHR
(gal)
RDS No
AHRI
No
Type
1 ................................
2 ................................
3 ................................
4 ................................
5 ................................
6 ................................
7 ................................
8 ................................
9 ................................
10 ..............................
11 ..............................
12 ..............................
13 ..............................
14 ..............................
N/A ....
N/A ....
N/A ....
N/A ....
N/A ....
N/A ....
N/A ....
N/A ....
1–105
2–14 ..
2–15 ..
1–122
1–120
1–114,
115.
1–106,
107.
1–110,
111.
1–108,
109.
1–112,
113.
1–116,
117.
1–118,
119.
Gas ...
Gas ...
Gas ...
Gas ...
Gas ...
Gas ...
Oil .....
Gas ...
Gas ...
Gas ...
Gas ...
Gas ...
Gas ...
Gas ...
72.9
48.3
93.7
70.9
94.9
69.6
50.3
48.4
93.1
49.0
49.0
71.3
49.0
48.3
75,600
76,500
78,900
76,900
83,700
75,600
140,000
75,500
75,200
76,800
76,800
79,600
76,800
75,100
74.1
93.6
80.4
82.8
80.0
76.9
76.7
89.5
80.1
97.3
97.3
82.7
97.3
92.6
1007.0
328.0
1178.2
580.2
1389.9
1407.2
908.2
348.3
1163.3
150.0
150.0
789.0
150.0
290.5
107.4
137.0
109.8
156.4
159.2
130.0
134.8
114.9
140.9
151.1
156.8
131.0
154.0
119.1
0.612
0.816
0.514
0.710
0.524
0.505
0.617
0.722
0.561
0.908
0.891
0.650
0.907
0.877
Gas ...
70.8
74,600
80.0
1052.0
113.8
0.625
Gas ...
71.1
75,100
81.0
921.0
107.6
0.642
Gas ...
95.0
74,000
80.5
1064.5
140.0
0.596
Gas ...
94.9
74,700
81.5
1063.0
125.9
0.587
Gas ...
49.4
101,300
96.5
422.5
109.9
0.865
Gas ...
74.2
101,400
96.0
408.5
174.0
0.842
15 ..............................
16 ..............................
17 ..............................
18 ..............................
19 ..............................
20 ..............................
UEF
TABLE III.36—RESIDENTIAL-DUTY COMMERCIAL WATER HEATER ATTRIBUTES
mstockstill on DSK3G9T082PROD with PROPOSALS2
RDS No
NOX Emission
level
Condensing
Vent type
Short or Tall
1 .....................................................................................
2 .....................................................................................
3 .....................................................................................
4 .....................................................................................
5 .....................................................................................
6 .....................................................................................
7 .....................................................................................
8 .....................................................................................
9 .....................................................................................
10 ...................................................................................
11 ...................................................................................
12 ...................................................................................
13 ...................................................................................
Low .................
Low .................
Standard .........
Standard .........
Ultra-Low ........
Ultra-Low ........
N/A. ................
Low .................
Low .................
Low .................
Low .................
Low .................
Not Specified ..
No ..................
Yes. ................
No ..................
No ..................
No ..................
No ..................
N/A. ................
Yes. ................
No ..................
Yes. ................
Yes. ................
Yes. ................
Yes. ................
Power ...............
Power ...............
Atmospheric .....
Power ...............
Atmospheric .....
Atmospheric .....
N/A. ..................
Power ...............
Atmospheric .....
Power ...............
Power ...............
Power ...............
Power ...............
Tall .................
Short ..............
Tall .................
Tall .................
Not Specified
Tall .................
Short ..............
Tall .................
Tall .................
Not Specified
Not Specified
Tall .................
Not Specified
15 If multiple tests were conducted on either the
same unit or same basic model of a water heater,
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the results were averaged to produce the values
reported in this SNOPR.
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Standing Pilot?
Yes.
No
Yes.
No
Yes.
Yes.
N/A.
No
Yes.
No
No
No
No
59777
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
TABLE III.36—RESIDENTIAL-DUTY COMMERCIAL WATER HEATER ATTRIBUTES—Continued
NOX Emission
level
Condensing
Vent type
Low .................
Standard .........
Standard .........
Ultra-Low ........
Ultra-Low ........
Ultra-Low ........
Ultra-Low ........
Yes. ................
No ..................
No ..................
No ..................
No ..................
Yes. ................
Yes. ................
Power ...............
Atmospheric .....
Atmospheric .....
Atmospheric .....
Atmospheric .....
Power ...............
Power ...............
RDS No
14
15
16
17
18
19
20
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
ii. Conversion Factor Results
As stated in section III.C.4.b, DOE is
not aware of an analytical model to
convert the represented values of
thermal efficiency and standby loss
under the prior commercial test
procedure to estimate the represented
value of first-hour rating under the new
test procedure. Therefore, DOE proposes
to use the step regression method
described in section III.C.2 along with
the best combination of water heater
attributes to determine the first-hour
rating conversion factor shown in Table
III.37. 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, the value
can be applied to determine the
appropriate draw pattern bin (i.e., very
small, low, medium, or high) using
Table 1 of the uniform efficiency
descriptor test procedure. 10 CFR 430,
subpart B, appendix E, section 5.4.1.
With the draw bin known, the UEF
value based on the analytical model can
be calculated using the process
described in section III.C.4 of this
document. The analytical results, along
with the results of the step regression
and the analytical regression, are
presented in Table III.38 and have
RMSD values of 0.032, 0.029, and 0.032,
respectively. DOE proposes to use the
combined analytical-regression
approach to calculate the residentialduty commercial storage water heater
conversion factor because the RMSD
value is within 0.003 of that of the
regression and the use of the analytical
portion of the conversion will likely
apply better to units that have not been
tested. The resulting equations for
determining the UEF of residential-duty
Short or Tall
Tall
Tall
Tall
Tall
Tall
Tall
Tall
.................
.................
.................
.................
.................
.................
.................
Standing Pilot?
No
Yes.
Yes.
Yes.
Yes.
No
No
commercial storage water heaters are
presented in Table III.37. In the
equations in Table III.37, Vr is the rated
volume, and Et is the thermal efficiency
in fractional form (e.g., 0.85 instead of
85 (%)). UEFrd is the result of the
analytical conversion, described in
section III.C.4.c. For these regressions,
DOE decided to group both oil-fired and
gas-fired water heaters because of the
lack of oil-fired water heaters identified.
TABLE III.37—PROPOSED RESIDENTIAL-DUTY COMMERCIAL STORAGE
CONVERSION FACTOR EQUATIONS
Product class
Conversion factor
All ResidentialDuty Commercial Storage Water
Heaters.
New FHR = ¥35.8233 +
0.4649 × Vr + 160.5089 ×
Et
New UEF = ¥0.0022 +
1.0002 × UEFrd
TABLE III.38—RESIDENTIAL-DUTY COMMERCIAL STORAGE CONVERSION RESULTS
Tested FHR
(gal)
mstockstill on DSK3G9T082PROD with PROPOSALS2
RDS No.
1 ...............................................................
2 ...............................................................
3 ...............................................................
4 ...............................................................
5 ...............................................................
6 ...............................................................
7 ...............................................................
8 ...............................................................
9 ...............................................................
10 .............................................................
11 .............................................................
12 .............................................................
13 .............................................................
14 .............................................................
15 .............................................................
16 .............................................................
17 .............................................................
18 .............................................................
19 .............................................................
20 .............................................................
107.4
137.0
109.8
156.4
159.2
130.0
134.8
114.9
140.9
151.1
156.8
131.0
154.0
119.1
113.8
107.6
140.0
125.9
109.9
174.0
In response to the NOPR, AHRI stated
that for gas-fired residential-duty
commercial storage water heaters, all
the measured UEF results are higher
than the converted UEF values using the
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Regression
FHR
(gal)
Tested UEF
117.0
136.9
136.8
130.1
136.7
120.0
110.7
130.3
136.0
143.2
143.2
130.1
143.2
135.2
125.5
127.3
137.5
139.1
142.0
152.8
0.612
0.816
0.514
0.710
0.524
0.505
0.617
0.722
0.561
0.908
0.891
0.650
0.907
0.877
0.625
0.642
0.596
0.587
0.865
0.842
mathematical conversion, and the
commenters added that the magnitude
of the difference seems to track with the
volume and thermal efficiency of the
water heater. (AHRI, No. 6 at p. 2)
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Analytical UEF
0.567
0.830
0.578
0.691
0.548
0.532
0.594
0.793
0.579
0.918
0.918
0.651
0.918
0.833
0.594
0.620
0.595
0.601
0.825
0.825
Regression
UEF
0.559
0.831
0.567
0.700
0.527
0.509
0.626
0.798
0.566
0.890
0.890
0.662
0.890
0.830
0.594
0.625
0.585
0.593
0.843
0.832
AnalyticalRegression
UEF
0.565
0.828
0.576
0.689
0.546
0.530
0.592
0.790
0.577
0.916
0.916
0.649
0.916
0.831
0.592
0.617
0.593
0.599
0.823
0.823
Bradford White stated that its results
show that both the UEF and FHR are
largely underestimated for residentialduty commercial gas-fired water heaters
when using the conversion factors.
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mstockstill on DSK3G9T082PROD with PROPOSALS2
(Bradford White, No. 14 at p. 2) NEEA
stated that for residential-duty
commercial water heaters, there is so
little correlation between the FHR and
UEF calculated from the mathematical
conversions and the measured values
from testing that it is not possible at this
point to use an analytical approach for
determining either of these values.
(NEEA, No. 15 at p. 6) NEEA elaborated
that it is also not clear at this point that
more testing (more sample models)
would be helpful, as NEEA believes
there are some missing variables/factors
that are not being taken into account in
the analytical methodologies. NEEA
tentatively concluded that these water
heaters will have to be tested in the near
term in order to produce represented
values of FHR and UEF that will match
the represented values later when all
water heaters must be re-certified based
on tested values. (NEEA, No. 15 at p. 6)
In response to AHRI and Bradford
White’s comment about the gas-fired
storage conversion underrating the UEF,
DOE notes that under the conversion
factor proposed in this SNOPR, there are
a similar number of gas-fired
residential-duty commercial units
where the converted UEF is either
higher or lower than the measured
UEF,16 which suggests that the new
conversion is a better representation of
the test data than was proposed in the
NOPR. Further, the RMSD values for the
NOPR and SNOPR conversions with the
current data set are 0.068 and 0.032,
respectively. In response to NEEA
comments, DOE notes that the analytical
method was updated based on other
commenters’ suggestions, and that the
resulting new conversion tracks better
with the measured data than the
conversion factor equation proposed in
the NOPR.
d. Residential-Duty Commercial
Instantaneous Water Heaters
As discussed in section III.B, DOE did
not propose a mathematical conversion
for residential-duty commercial gasfired instantaneous water heaters in the
April 2015 NOPR. The definition of
residential-duty commercial water
heater applies to commercial equipment
and specifically excludes gas-fired
instantaneous water heaters with an
input rating above 200,000 Btu/h. 10
CFR 431.102. As defined in EPCA, gasfired instantaneous water heaters with
an input rating at or below 200,000 Btu/
16 Of the 20 residential-duty commercial units
tested, 9 had a UEF value predicted by the
conversion equation that was lower than the
measured UEF; 7 units had a predicted UEF that
was higher than the measured UEF, and 4 units had
a predicted UEF that was equal to the measured
UEF, after rounding to the second decimal place.
VerDate Sep<11>2014
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h are consumer products, not
commercial equipment. (42 U.S.C.
6291(27)(B)) As such, the definition of
residential-duty commercial water
heater definition precludes all gas-fired
instantaneous water heaters from being
so defined.
DOE has tentatively concluded a
mathematical conversion factor and
standard denominated in UEF are
necessary for residential-duty
commercial electric instantaneous water
heaters. DOE tested 1 residential-duty
commercial electric instantaneous water
heater to the test procedure that was
proposed in the UEF test procedure
NOPR. 78 FR 66202 (Nov. 4, 2013). The
maximum GPM conversion is based on
a regression, and DOE included this
data point for the residential-duty
commercial electric instantaneous unit
in that conversion without the need for
further testing, because there were no
substantial changes to the maximum
GPM test for electric instantaneous
water heaters between the UEF test
procedure NOPR and final rule. Because
of the small amount of data available
and the relative similarity between units
above and below the 12 kW cut-off
between consumer and residential-duty
commercial water heaters, DOE also
used the 5 consumer electric
instantaneous water heaters that were
tested (see section III.E.2.b) in the
development of the mathematical
conversion factor for the maximum
GPM of residential-duty commercial
electric instantaneous water heaters.
Table III.39 below presents the
residential-duty commercial electric
instantaneous water heater test data
used to develop the conversion factors.
TABLE III.39—RESIDENTIAL-DUTY
COMMERCIAL INSTANTANEOUS
WATER HEATER TEST DATA
RDI No.
Input rate
(Btu/h)
Updated
max GPM
83,600
2.48
1 ............
UEF
0.948
DOE examined potential parameters
for predicting the maximum GPM rating
of residential-duty commercial electric
instantaneous water heaters. Given the
de minimis losses from electric heating
elements, and the de minimis standby
losses associated with tankless water
heaters, DOE believes that it is
appropriate to assume that the delivery
capacity would be heavily dependent on
the input rating for electric
instantaneous water heaters. DOE
examined the predicted maximum GPM
as a function of input rate, and
developed an equation which results in
an RMSD of 0.009 gpm. DOE proposes
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to use the following equation as the
mathematical conversion factor for max
GPM, where Q is input rate in kBtu/h.
New Max GPM = 0.0146 + 0.0295 * Q
DOE has tentatively determined that
the UEF value shown in Table III.39,
which is a result of the UEF test
procedure NOPR is not appropriate for
use in a regression based conversion. As
described in section III.C.4.c.iv, DOE
has proposed an analytical method for
determining the UEF conversion, and as
such, this test point was not necessary
to develop the UEF conversion. DOE
proposes to use the analytical method
described in section III.C.4.c.iv as the
conversion for residential-duty
commercial electric instantaneous water
heaters.
e. Grid-Enabled Storage Water Heaters
Grid-enabled water heaters have a
rated storage volume above 75 gallons
and use electric resistance elements to
heat the stored water. At the time of its
analysis for this notice, DOE was unable
to find grid-enabled water heaters
available on the market which meet the
definition of ‘‘grid-enabled water
heater’’ 17 as set forth in EEIA 2015. As
a result, DOE does not have any test
data for grid-enabled water heaters
specifically. However, DOE does have a
large set of data for electric resistance
storage water heaters, which DOE
believes would have similar energy
consumption-related characteristics to
grid-enabled water heaters, aside from
the differences in stored volume. DOE
has conducted testing of 18 consumer
electric storage water heaters, which use
electric resistance elements and were
17 Grid-enabled water heater means an electric
resistance water heater that—
(1) Has a rated storage tank volume of more than
75 gallons;
(2) Is manufactured on or after April 16, 2015;
(3) has: (i) An energy factor of not less than 1.061
minus the product obtained by multiplying—(a) the
rated storage volume of the tank, expressed in
gallons, and (b) 0.00168; or (2) an equivalent
alternative standard prescribed by the Secretary and
developed pursuant to 42 U.S.C. 6295(e)(5)(E);
(4) Is equipped at the point of manufacture with
an activation lock and;
(5) Bears a permanent label applied by the
manufacturer that—
(i) Is made of material not adversely affected by
water;
(ii) Is attached by means of non-water-soluble
adhesive; and
(iii) Advises purchasers and end-users of the
intended and appropriate use of the product with
the following notice printed in 16.5 point Arial
Narrow Bold font: ‘‘IMPORTANT INFORMATION:
This water heater is intended only for use as part
of an electric thermal storage or demand response
program. It will not provide adequate hot water
unless enrolled in such a program and activated by
your utility company or another program operator.
Confirm the availability of a program in your local
area before purchasing or installing this product.’’
(42 U.S.C. 6295(e)(6)(A)(ii))
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59779
New FHR = 9.2827 + 0.8092 × FHRP
As with electric storage water heaters
with storage volumes less than 55
gallons, DOE used the hybrid approach
of using both the WHAM equation and
a regression to calculate the UEF.
Because no grid-enabled water heater
products are available on the market,
DOE applied the regression equations
derived using the electric storage water
heaters with storage volumes less than
55 gallons since the technology
employed is very similar. DOE is
proposing to use the following
conversion equations to determine the
UEF (shown as ‘‘New UEF’’ in the
equation):
the market, and then applying that
percent difference to the estimated UEF
(based on the conversion factor) to
determine the new minimum UEF
requirement that maintains the same
stringency. However, because the
‘‘percent difference’’ method was based
on actual water heaters from the CCMS
and AHRI directories, the method could
only directly be applied to categories
that had water heaters in them. Thus,
DOE had to extrapolate standards from
similar classes for categories where
there were no models on the market,
such as the consumer gas-fired storage
water heaters greater than 55 gallons
category. For this SNOPR, DOE has
developed a new methodology that it
proposes for translating the energy
conservation standards to UEF, which
DOE believes would improve the results
of the standards translation. DOE has
termed this new approach as the
‘‘representative model’’ method, which
consists of the following steps for
determining the minimum UEF
standard:
1. Using the CCMS and AHRI
directories, for minimally-compliant
models, determine the unique rated
storage volumes available on the market
prior to July 13, 2015 (the date on which
DOE’s requirement that rated storage
volume equal the mean of the measured
storage volume was effective; see
section III.E.3.a).
2. For each rated storage volume
identified in step 1, find average values
of conversion factor inputs (i.e., input
rating and recovery efficiency for
consumer water heaters (except
consumer heat pump water heaters),
and input rating for residential-duty
commercial water heaters) for
minimally-compliant models in each
product class. (For product classes
where no minimally-compliant models
exist on the market, DOE used other
methods to estimate the characteristics
of minimally-compliant models, as
discussed in detail subsequently.)
3. Calculate the energy conservation
standard (in terms of EF for consumer
water heaters and TE/SL for residentialduty commercial water heaters (with
input rate for determining standards
found from step 2)) for each product
class based on the rated storage volume,
as reported in the CCMS and AHRI
directories at the time of this analysis
(before DOE’s requirement that rated
storage volume equal the mean of the
measured storage volume was effective).
4. Using applicable average values for
conversion factor inputs determined in
step 2 and the applicable minimum
energy conservation standards
calculated in step 3, calculate the
equivalent UEF for minimallycompliant models at each discrete rated
storage volume (determined in step 1)
using the appropriate conversion factor
for the product class.
5. Adjust the rated storage volumes to
estimate the rated storage volume that
would reflect DOE’s requirement at 10
CFR 429.17(a)(1)(ii)(C) that rated storage
volume equal the mean of the measured
storage volume of all units within the
sample. DOE estimated that for electric
storage water heaters, the rated storage
volume would decrease by 10 percent,
and for gas-fired and oil-fired water
3. Energy Conservation Standard
Derivation
After developing the mathematical
conversion factors to convert from the
prior tested values under the EF metric
to the tested values under the UEF
metric, the next step is to translate the
energy conservation standards to be in
terms of UEF. In the April 2015 NOPR
analysis, DOE investigated several
possible methods to determine the
appropriate energy conservation
standards in terms of UEF, and sought
comments on the various approaches.
80 FR 20116, 20136–38 (April 14, 2015).
DOE ultimately proposed using the
‘‘percent difference’’ method, which
would have updated the minimum
standards by first calculating the
percent difference between the prior EF
rating and standard for each model on
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electric storage water heaters with
storage volumes less than or equal to 55
gallons. Therefore, DOE used the same
test data to derive the grid-enabled
consumer storage water heater
conversion factors as was used to derive
the consumer electric storage water
heater conversion factor.
For the first-hour rating conversion,
the only conversion method available is
the regression approach. Therefore, the
data set of electric resistance consumer
electric storage water heaters was used
to derive the following equation:
DOE considered simply using the
WHAM equation for the conversion of
grid-enabled water heaters, but the
inclusion of the regression step makes
the corresponding energy conservation
standards (discussed in III.E.3) more
consistent with those developed for
electric storage water heaters with
storage volumes at or below 55 gallons,
which DOE believes are very similar
products at lower storage volumes. DOE
seeks comment on its method of
applying the regression for electric
storage water heaters with storage
volumes at or below 55 gallons in
developing the conversion equation for
grid-enabled water heaters. This is
identified as issue 1 in section V.B,
‘‘Issues on Which DOE Seeks
Comment.’’
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tested to both the EF and UEF test
procedures, and AHRI has supplied test
data for 27 additional units of this water
heater type. DOE believes that the
electric resistance technology used in
grid-enabled water heaters to heat water
would be similar enough to the
technology used in the less than or
equal to 55 gallon class of consumer
electric water heaters to be applicable in
the derivation of the grid-enabled
conversion and energy conservation
standard derivation. Similarly, the
insulation type and thickness in gridenabled water heaters is expected to be
the same as that currently used in
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heaters, the rated storage volume would
decrease by 5 percent.
6. For each product class and draw
pattern, using a simple regression, find
the slope and intercept where the
independent variable is the range of
adjusted rated storage volumes
(determined in step 5) and the
dependent variable is the UEF values
associated with the rated storage
volumes and specific draw pattern
calculated in step 4.
As discussed in section III.B, the
energy conservation standards for water
heaters established in EPCA (and for
electric water heaters, the standards as
adjusted by the 1990 test procedure
final rule) apply to all consumer water
heaters regardless of storage volume or
input rate. Therefore, in addition to the
classes of water heaters for which DOE
proposed UEF-based standards in the
NOPR, DOE is also proposing updated
standards based on the UEF test
procedure for the types of water heaters
described in Table III.1.18 Although
there were few or no water heaters in
those categories described in Table III.I,
DOE used the ‘‘representative model’’
method described previously by
estimating values for input rate and
recovery efficiency to determine the
converted UEF standard level.
For consumer gas-fired storage water
heaters, there are three separate
conversion factors: (1) For standard (i.e.,
not low NOX or ultra-low NOX) and low
NOX non-condensing models; (2) for
ultra-low NOX non-condensing models;
and (3) for condensing models. For
water heaters with a storage volume less
than or equal to 55 gallons, the
conversion factor for standard and low
NOX non-condensing models was used
to develop the proposed updated energy
conservation standard, as the standard
for gas-fired storage water heaters with
a storage volume less than or equal to
55 gallons is at a non-condensing level.
DOE chose to use the equation for
standard and low NOX non-condensing
models, rather than for ultra-low NOX
non-condensing models, since standard
and low NOX non-condensing models
make up the majority of the gas-fired
storage water heater market. DOE
considered proposing to establish
18 These water heaters include gas-fired storage,
electric storage, and tabletop water heaters at or
above 2 gallons storage volume and below 20
gallons storage volume; gas-fired storage water
heaters above 100 gallons storage volume; oil-fired
storage water heaters above 50 gallons storage
volume; electric storage water heaters above 120
gallons storage volume; gas-fired instantaneous
water heaters with an input at or below 50,000 Btu/
h or at or above 2 gallons storage volume; electric
instantaneous water heaters at or above 2 gallons
storage volume; and oil-fired electric instantaneous
water heaters.
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separate standards for ultra-low NOX
models based on the conversion factor
for these products, but found that the
slight differences in the resultant
standards for ultra-low-NOX water
heaters would not justify the additional
complexity in the Department’s water
heater regulations if separate standards
were to be developed. The average
difference between the standard and
low-NOX and ultra-low-NOX energy
conservation standards for the very
small, low, medium, and high draw
patterns, was ¥0.041, ¥0.008, ¥0.006,
and 0.003, respectively.19
Manufacturers are required to certify
UEF values rounded to the nearest 0.01
(10 CFR 429.17(b)(2)), so differences
lower than that would effectively result
in the same standard level for the
majority of units on the market. The
very small draw pattern standard would
not be expected to have a negligible
difference; however, DOE is not aware
of any units that are on the market
which would test to this draw pattern.
DOE did not consider using the
condensing gas-fired storage conversion
for units less than or equal to 55 gallons
because the resulting standard would be
much more stringent than the current
energy conservation standards. DOE
seeks comments on the use of the
standard and low-NOX conversion to
calculate the energy conservation
standard for consumer gas-fired storage
water heaters less than or equal to 55
gallons, and its tentative decision not to
propose separate standards for ultra-low
NOX gas-fired storage water heaters.
This is identified as issue 2 in section
V.B, ‘‘Issues on Which DOE Seeks
Comment.’’
For consumer gas-fired storage water
heaters above 55 gallons, there are no
water heaters on the market; therefore,
DOE assumed the input rate to be 65
kBtu/h and the recovery efficiency to be
0.90 when performing the conversion to
UEF for translating the standard. The
input rate of 65 kBtu/h was determined
based on listings available in the AHRI
Directory at the time of this analysis.
DOE examined all models listed in the
AHRI Directory (including those marked
as discontinued or obsolete) and
determined that the median input rate
of gas-fired storage water heaters above
55 gallons is 65 kBtu/h, which is also
the most frequently occurring input rate.
DOE used 0.90 as the recovery
efficiency based on the recovery
efficiency of the only two condensing
consumer water heater models that DOE
19 Averages differences are calculated using
storage volumes from 20 to 55 gallons, in
increments of 1 gallon, where the minimum UEF
values have been rounded to the nearest 0.01.
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has identified on the market (both of
which have storage volume below 55
gallons). DOE used these values along
with the conversion factor for
condensing gas-fired storage water
heaters to derive the above 55-gallon
energy conservation standard. DOE
seeks comments from stakeholders
regarding its assumptions for the typical
input rating and recovery efficiency of
consumer gas-fired storage water heaters
above 55 gallons. This is identified as
issue 3 in section V.B, ‘‘Issues on Which
DOE Seeks Comment.’’
In the consumer electric
instantaneous water heaters product
class, there are no minimally-compliant
models available on the market.
Therefore, DOE estimated the recovery
efficiency for minimally compliant
models in order to perform the
calculations required to convert the
standard. The recovery efficiency of
models available on the market is 0.98,
while the average EF available on the
market was 0.99. Given the similarity of
the EF rating and recovery efficiency
observed in electric instantaneous
models, DOE estimated the recovery
efficiency of minimally-compliant
models as being equal to the EF (which
at the minimally-compliant level is
0.93). DOE recognizes, however, that it
is unlikely that a model using electric
resistance elements would have a
recovery efficiency of 0.93, but rather, it
is more likely that the recovery
efficiency of a minimally compliant
model would be maintained at 0.98
while additional standby losses or
cycling losses would result in a lower
EF. Given the design of products
currently on the market (upon which
the conversion factor is based), both
cycling and standby losses are minimal,
and as a result, the conversion factor is
based almost entirely on recovery
efficiency. Therefore, DOE
approximated a reduction in cycling
and standby losses by lowering recovery
efficiency such that the overall
converted UEF would be lowered, in
order to keep the converted standard at
an equivalent level; without this
reduction, the resulting standard level
would be set much closer to the level of
performance of current models, which
would represent an increase in
stringency. DOE seeks comment on this
approach for estimating the recovery
efficiency of a minimally-compliant
(i.e., 0.93 EF) electric instantaneous
water heater. This is identified as issue
4 in section V.B, ‘‘Issues on Which DOE
Seeks Comment.’’ The current DOEprescribed energy conservation standard
for electric instantaneous water heaters
at 10 CFR 430.32(d) is at the same level
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as those set forth in EPCA (42 U.S.C.
6295(e)(1)(C)) and shown in Table I.1.
These standards are not limited by
storage volume, and, therefore, DOE has
tentatively decided to propose one set of
standard equations for all storage
volumes of consumer electric
instantaneous water heaters (0 to 10.24
gallons).20 To derive the updated energy
conservation standards for consumer
electric instantaneous water heaters
below 2 gallons, the instantaneous
conversion was used, and for units at or
above 2 gallons, the storage conversion
was used. DOE believes the use of the
storage conversion factor for
representative units at or above 2
gallons is more appropriate given the
greater standby losses which would
occur during the tests of these units.
DOE notes that the instantaneous
conversion estimates cycling losses for
instantaneous water heaters and that the
storage conversion estimates standby
losses. Average input rates for units on
the market were used for below 2
gallons units, and an input rate of 12
kW was assumed for all at or above 2
gallons units.
For grid-enabled storage water
heaters, there were no minimallycompliant models available on the
market at the time of analysis, so DOE
assumed representative volumes of 75
and 120 gallons and input rates of 4.5
kW at both volumes.
For consumer electric storage water
heaters below 20 gallons, DOE found
that there were units on the market, but
these units were not reported in the
AHRI or CCMS databases. DOE searched
through manufacturers’ product
literature to compile a list of units with
their respective storage volumes and
input rates. At each rated storage
volume, the associated input rates were
averaged to obtain a representative
value. For consumer electric storage
water heaters above 120 gallons, DOE
found that there were no units on the
market. Therefore, DOE assumed
representative rated storage volumes of
121 gallons and 705 gallons. The upper
bound of 705 gallons is the point at
which the applicable EPCA standard,
found in Table I.1, would be zero. The
recovery efficiency is assumed to be 98
percent for all water heaters using
submerged electric resistance heating
elements, and the input rate for units
20 10.24 gallons is the maximum possible storage
volume for an electric instantaneous water heater
because EPCA defines these products as having no
more than one gallon of water per 4,000 Btu per
hour of input and a maximum input rating of 12
kW. 12 kW converts to 40,946 Btu/h, which when
divided by 4,000 Btu/h results in a maximum
storage volume of 10.24 gallons to be considered as
an electric instantaneous water heater.
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with a capacity above 120 gallons is
assumed to be 12 kW (i.e., the maximum
allowable input capacity in the
consumer electric water heater class).
For consumer tabletop water heaters
with storage volumes below 20 gallons
or above 120 gallons, the current DOEprescribed energy conservation
standards are at the same level as those
prescribed in the EPCA standards,
found in Table I.1. Therefore, DOE
tentatively proposes to extend the
updated energy conservation standards
derived for units between 20 and 120
gallons to all tabletop units, regardless
of storage volume.
For consumer gas-fired storage water
heaters, less than 20 gallons and greater
than 100 gallons, DOE found that there
were no units currently on the market.
Therefore, DOE assumed that if such
models were to exist in the less than 20
gallon size, they would have a similar
representative storage volume as for
consumer electric storage water heaters
less than 20 gallons, and used those
values as representative storage
volumes. For storage volumes above 100
gallons, DOE used representative storage
volumes of 101 and 326 gallons which
represent the lower and upper bounds,
respectively. The upper bound of 326
gallons is the point at which the
applicable EPCA standard, found in
Table I.1, would be zero, and DOE used
this as the upper bound for storage
capacity. The recovery efficiency for all
units is assumed to be the average of the
recovery efficiencies available for
minimally compliant units between 20
and 55 gallons, which was found to be
79 percent. DOE observed in the AHRI
and CCMS databases that there was one
consumer gas-fired storage water heater
at 20 gallons, which had an input rate
of 75,000 Btu/h. This suggests that the
design of consumer gas-fired storage
water heaters below 20 gallons would
trend towards higher input rates.
Therefore, DOE assumed input rates for
units below 20 gallons to be at the 4,000
Btu/h/gal limitation between storage
and instantaneous water heaters, which
is the maximum input allowable to be
within the gas-fired storage water heater
product class for a given volume. (42
U.S.C. 6291(27)(B)) An input rate of
75,000 Btu/h was used for storage
volumes where the input rate using the
4,000 Btu/h/gal limitation would result
in a value greater than 75,000 Btu/h, as
that is the maximum input capacity for
consumer gas-fired storage water
heaters. For consumer gas-fired storage
water heaters with greater than 100
gallons storage volume, the input rate
was assumed to be 75,000 Btu/h.
For consumer oil-fired storage water
heaters with a capacity above 50
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59781
gallons, recovery efficiency and input
rate values are assumed to be 85 percent
and 105,000 Btu/h, respectively.
For consumer oil-fired instantaneous
water heaters, the maximum possible
input rate as defined by EPCA at 42
U.S.C. 6291(27)(B) is 210,000 Btu/h.
This input rate corresponds to a
maximum storage volume of 52.5
gallons (based on the 4,000 Btu/h per
gallon of stored water limitation
between instantaneous and storage
water heaters). Due to the large storage
volumes that are possible in this class
of water heater, the consumer oil-fired
storage conversion was used to derive
the updated UEF standards. The average
storage volume, input rate, and recovery
efficiency for units on the market is 5
gallons, 148,000 Btu/h, and 88 percent,
respectively. Therefore, DOE used the
representative market average data point
along with the largest possible storage
volume and input rate to determine the
energy conservation standards equation
in terms of UEF. A recovery efficiency
of 88 percent was also used for the 52.5
gallon data point.
For consumer gas-fired instantaneous
water heaters the current DOEprescribed energy conservation
standards (as amended in the April 2010
final rule and with which compliance
was required in April 2015) cover
models with: (1) Storage volumes below
2 gallons or (2) an input rate above
50,000 Btu/h. All other consumer gasfired instantaneous water heaters would
be subject to the standards initially
established by EPCA shown in Table I.1.
These two attributes are not mutually
exclusive; that is, a unit could exist that
has a rated storage volume at or above
2 gallons and an input rate at or below
50,000 Btu/h. DOE considered
proposing a separate set of standards for
each unique storage volume and input
rate combination (e.g., above 50,000
Btu/h and at or above 2 gallons, at or
below 50,000 Btu/h and below 2
gallons, or at or below 50,000 Btu/h and
at or above 2 gallons), or proposing a
single standard that would cover all
consumer gas-fired instantaneous water
heaters with storage volume at or above
2 gallons, or input rate at or below
50,000 Btu/h. Over the range of
applicable storage volumes, the methods
produce UEF values that are within 0.01
of each other. Therefore, to reduce the
complexity of its standards for water
heaters, DOE proposes to use a single set
of standard equations for consumer gasfired instantaneous water heaters with
rated storage volumes at or above 2
gallons or input rates at or below 50,000
Btu/h. Representative storage volumes
of 0, 2, 12.5, and 50 gallons were used
to derive the updated standards. These
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storage volumes represent various key
points. The storage volumes 0 gallons
and 12.5 gallons represent the bounds of
instantaneous water heaters with an
input rate at or below 50,000 Btu/h.
(Because an instantaneous water heater
is defined as containing no more than 1
gallon of stored water per 4,000 Btu/h
of input, the maximum storage volume
for a 50,000 Btu/h instantaneous water
heater is 12.5 gallons.) The storage
volumes 2 and 50 gallons represent the
bounds of instantaneous water heaters
with storage volumes at or above 2
gallons. (Consumer instantaneous water
heaters have a maximum input rate of
200,000 Btu/h. Because instantaneous
water heaters are defined as having no
more than 1 gallon of stored water per
4,000 Btu/h of input, the maximum
storage volume for a 200,000 Btu/h
consumer instantaneous water heater is
50 gallons.) DOE assumed that for
models at or below 50,000, Btu/h the
representative input rate would be
50,000 Btu/h. For the models with a
storage volume at 2 gallons, DOE used
the input rate at the average of models
currently available on the market for
minimally compliant units with 0
gallons of storage volume as the
representative input rate. DOE assumed
that the input rate of such a unit would
be similar to models on the market with
no storage volume. For models with a
storage volume larger than 2 gallons,
DOE assumed a representative input
rate of 200,000 Btu/h. Recovery
efficiencies were assumed to be 76
percent for all volumes. This recovery
efficiency value is less than the average
currently available on the market, but
DOE believes it is more representative of
a unit that would have been on the
market when the EPCA standards were
first prescribed. DOE used the consumer
gas-fired storage conversion to derive
the updated standards due to the storage
volumes being in the range typically
observed for storage water heaters.
For residential-duty commercial oilfired storage water heaters, the standard
increased from 78 to 80 percent in
October 2015. 10 CFR 431.110. DOE
used the average input rates for all
residential-duty commercial oil-fired
storage water heaters that comply with
the amended standard to derive the
inputs needed for the updated energy
conservation standard.
For residential-duty commercial
electric instantaneous water heaters,
there were no minimally-compliant
units (i.e., thermal efficiency of 80
percent) on the market. As with
consumer electric instantaneous water
heaters, DOE recognizes that it is
unlikely that a model using electric
resistance elements would have a
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thermal efficiency of 80 percent, and the
thermal efficiency of such equipment is
likely to be much higher. However, DOE
used the thermal efficiency value of 80
percent in calculating the equivalent
UEF standard, because this represents a
hypothetical minimally-compliant
model. DOE used the proposed
conversion equation for each draw
pattern (see section III.E.2.d) to predict
the UEF of a minimally-compliant
model.
In response to the translated
standards presented in the April 2015
NOPR, AHRI, Bradford White, and
Rheem raised concerns that the
stringency of the updated standards was
not maintained. (AHRI, No. 13 at p. 4;
Bradford White, No. 14 at p. 2; Rheem,
No. 11 at p. 2) In particular, Rheem
commented that 20 of the 43 consumer
storage water heaters that DOE tested in
support of the NOPR generated tested
UEF values less than the applicable
converted UEF value chosen by the DOE
in the NOPR. Rheem elaborated that, in
order for the stringency of energy
efficiency standards to not be altered
during the transition from the UEF
conversion factor period to the UEF
tested value period thereafter, a tested
value of UEF for a water heater model
should comply if its converted UEF
value complies with the proposed
minimum standard. (Rheem, No. 11 at
p. 5) Rheem also stated that three of the
seven residential-duty commercial
water heaters tested by DOE have tested
UEF values below their respective
analytical-regression UEF values. Given
that these water heaters currently
comply with thermal efficiency and
standby loss standards in effect and the
DOE’s tentative determination in the
NOPR to use the analytical-regression
method to generate the UEF conversion
factor for residential-duty commercial
water heaters, Rheem asserted that there
is cause for concern that the UEF
conversion factor will result in the
minimum energy conservation standard
for this water heater classification
becoming more stringent. (Rheem, No.
11 at p. 5)
Bradford White asserted that the
proposed converted standard in terms of
UEF for electric storage water heaters is
more stringent than the EF standard.
(Bradford White, No. 14 at p. 2) AHRI
also claimed that the proposed UEF
standard for electric storage water
heaters is too stringent, arguing that the
converted UEF values for these models
in the NOPR were higher than the tested
UEF values and that models complying
with the EF standards would not meet
the UEF standards. (AHRI, No. 6 at p.
2) Rheem asserted that for consumer
electric storage water heaters tested
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using the low draw pattern, test data
consistently revealed tested UEF values
three to four points below the proposed
UEF minimum. For consumer electric
storage water heaters tested using the
medium draw pattern, Rheem observed
that there were some measured UEF
values two to three points below the
proposed UEF minimum. (Rheem, No.
11 at p. 4) EEI stated that the proposed
UEF minimums for electric storage
water heaters are not neutral for
products representing a large share of
the consumer market. (EEI, No. 17 at p.
2)
Bradford White stated that the
proposed converted standard in terms of
UEF for gas-fired storage water heaters
tested using the high draw pattern is
less stringent than the EF standard, and
that the standard for models tested
using the medium draw pattern would
be more or less stringent, depending on
the model. (Bradford White, No. 14 at p.
2) Rheem stated that for gas-fired storage
models tested using the high draw
pattern, its test data showed measured
UEF values two to three points higher
than the proposed converted UEF
standards. EEI commented that there
were issues with gas-fired storage water
heaters at high draw patterns, where the
converted minimum UEF standard is
less stringent than the EF standard. (EEI,
No. 17 at p. 2)
Rheem commented that for several
models tested by DOE (identified in the
April 2015 NOPR as CS–6, CS–13, CS–
29, CS–30, and CS–39) the measured
UEF was less than the converted UEF
standard. Rheem stated that for gas-fired
instantaneous water heaters that would
be tested with the medium draw
pattern, the measured UEF is 1 point
lower than the proposed minimum UEF
level. Rheem also stated that for gasfired instantaneous water heaters that
would be tested with the high draw
pattern, the measured UEF is
consistently 2 to 3 points higher than
the proposed minimum UEF level.
(Rheem, No. 11 at p. 4) Further, Rheem
stated that after the 1 year application
period of the conversion factor, units
which previously passed the minimum
EF standards could test to fail the
updated minimum UEF standards.
(Rheem, No. 11 at p. 3)
In response to these comments, DOE
acknowledges that the test data
presented in section III.E.2 show that
some units which previously passed the
EF energy conservation standards would
fail the proposed UEF standards, while
other units which previously failed
would now pass. As discussed in
section III.A, DOE recognizes that the
conversion factors presented cannot
perfectly model the behavior of all water
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heaters, and therefore, uncertainty is
carried through to deriving the updated
energy conservation standards. The
standards presented in Table III.40 and
Table III.41 were derived using a
method that was intended to reduce the
number of units that would either be
non-compliant under the EF test method
and compliant under the UEF test
method or vice versa, so as to maintain
the stringency of the updated standard.
Nevertheless, to ensure that water
heaters which previously passed the EF
energy conservation standards will
continue to comply, pre-existing models
that are compliant with the EF energy
59783
conservation standards are
‘‘grandfathered,’’ as described below in
section III.F.
The proposed standards in terms of
uniform energy factor are shown below
by product class and draw pattern.
TABLE III.40—PROPOSED CONSUMER WATER HEATER ENERGY CONSERVATION STANDARDS
Product class
Rated storage volume and input rating
(if applicable)
Draw pattern
Gas-fired Storage Water Heater ................
<20 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 .........................
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 .........................
Very Small ...............
Low ..........................
Medium ....................
High .........................
Very Small ...............
Low ..........................
Medium ....................
High .........................
Very Small ...............
Low ..........................
Medium ....................
High .........................
Very Small ...............
≥20 gal and ≤55 gal ...................................
>55 gal and ≤100 gal ................................
>100 gal .....................................................
Oil-fired Storage Water Heater ..................
≤50 gal .......................................................
>50 gal .......................................................
Electric Storage Water Heaters .................
<20 gal .......................................................
≥20 gal and ≤55 gal ...................................
>55 gal and ≤120 gal ................................
>120 gal .....................................................
Tabletop Water Heater ..............................
All ...............................................................
Instantaneous Gas-fired Water Heater ......
<2 gal and >50,000 Btu/h ..........................
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≥2 gal or ≤50,000 Btu/h .............................
Instantaneous Oil-fired Water Heater ........
All ...............................................................
Instantaneous Electric Water Heater .........
All ...............................................................
Grid-Enabled Water Heater .......................
>75 gal .......................................................
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Uniform energy factor
0.2471
0.5132
0.5827
0.6507
0.3456
0.5982
0.6483
0.6920
0.6470
0.7689
0.7897
0.8072
0.1755
0.4671
0.5719
0.6916
0.1822
0.5313
0.6316
0.7334
0.1068
0.4190
0.5255
0.6438
0.7836
0.8939
0.9112
0.9255
0.8808
0.9254
0.9307
0.9349
1.9236
2.0440
2.1171
2.2418
0.6802
0.8620
0.9042
0.9437
0.6323
0.9188
0.9577
0.9884
0.7964
0.8055
0.8070
0.8086
0.3013
0.5421
0.5942
0.6415
0.1430
0.4455
0.5339
0.6245
0.9161
0.9159
0.9160
0.9161
1.0136
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
¥
(0.0002 × Vr).
(0.0012 × Vr)
(0.0015 × Vr).
(0.0019 × Vr).
(0.0020 × Vr).
(0.0019 × Vr).
(0.0017 × Vr).
(0.0013 × Vr).
(0.0006 × Vr).
(0.0005 × Vr).
(0.0004 × Vr).
(0.0003 × Vr).
(0.0006 × Vr).
(0.0015 × Vr).
(0.0018 × Vr).
(0.0022 × Vr).
(-0.0001 × Vr).
(0.0014 × Vr).
(0.0020 × Vr).
(0.0028 × Vr).
(0.0007 × Vr).
(0.0017 × Vr).
(0.0021 × Vr).
(0.0025 × Vr).
(0.0013 × Vr).
(0.0008 × Vr).
(0.0007 × Vr).
(0.0006 × Vr).
(0.0008 × Vr).
(0.0003 × Vr).
(0.0002 × Vr).
(0.0001 × Vr).
(0.0011 × Vr).
(0.0011 × Vr).
(0.0011 × Vr).
(0.0011 × Vr).
(0.0003 × Vr).
(0.0006 × Vr).
(0.0007 × Vr).
(0.0007 × Vr).
(0.0058 × Vr).
(0.0031 × Vr).
(0.0023 × Vr).
(0.0016 × Vr).
(0.0000 × Vr).
(0.0000 × Vr).
(0.0000 × Vr).
(0.0000 × Vr).
(0.0023 × Vr).
(0.0024 × Vr).
(0.0021 × Vr).
(0.0017 × Vr).
(0.0015 × Vr).
(0.0023 × Vr).
(0.0023 × Vr).
(0.0021 × Vr).
(0.0039 × Vr).
(0.0009 × Vr).
(0.0005 × Vr).
(0.0003 × Vr).
(0.0028 × Vr).
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TABLE III.40—PROPOSED CONSUMER WATER HEATER ENERGY CONSERVATION STANDARDS—Continued
Rated storage volume and input rating
(if applicable)
Product class
Draw pattern
Low ..........................
Medium ....................
High .........................
Uniform energy factor
0.9984 ¥ (0.0014 × Vr).
0.9853 ¥ (0.0010 × Vr).
0.9720 ¥ (0.0007 × 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.41—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 ..........................
Very Small ................
Low ...........................
Medium ....................
High ..........................
Oil-fired Storage ................................................................................................................
Electric Instantaneous .......................................................................................................
Uniform energy factor
0.2670
0.5356
0.5996
0.6592
0.2932
0.5596
0.6194
0.6740
0.80
0.80
0.80
0.80
¥
¥
¥
¥
¥
¥
¥
¥
(0.0009
(0.0012
(0.0011
(0.0009
(0.0015
(0.0018
(0.0016
(0.0013
×
×
×
×
×
×
×
×
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
mstockstill on DSK3G9T082PROD with PROPOSALS2
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as specified by the manufacturer.
Lutz suggested determining the
energy conservation standards using
only test data from minimally-compliant
water heaters. He stated that this
method would remove the uncertainty
which compounds throughout the
conversion process. (Lutz, No. 16 at p.
3) DOE believes that an appropriate
amount of minimally-compliant water
heater test data is currently not present
to pursue this method. Based on
stakeholder comments, DOE selected
units for testing with a range of
attributes and associated EF levels. As
the effect of the uniform efficiency
descriptor test procedure cannot be fully
known without testing all units on the
market, it is a possibility that a
minimally compliant unit may perform
better than a unit that was rated above
the minimum. Further, a water heater
would have to have a tested EF at the
minimum energy conservation standard,
not just be rated at the minimum.
Therefore, for these reasons, DOE did
not use this method for deriving the
proposed standards.
Rheem and AHRI argued that the
relative difference between the
minimum EF and EF should be
maintained between the minimum UEF
and UEF values. (Rheem, No. 11 at p. 3;
AHRI, No. 6 at p. 2) AHRI also asserted
that if the relative difference is not
maintained, then a manufacturer’s
investment could be wasted. (AHRI, No.
3 at p. 2) AHRI expressed the view that
it is more important to look at the
difference in the measurements between
the EF and UEF test procedures, and
recommended that DOE should examine
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the difference in EF and UEF
measurements for models rated at the
applicable minimum EF value to help
check the validity of the proposed
converted minimum standards. (AHRI,
No. 13 at p. 5) DOE agrees that the
relative difference between minimum
and rated values is an important factor
to consider when developing the energy
conservation standards. The proposed
‘‘representative model’’ method uses the
EF-denominated energy conservation
standard values to derive the new
standard equations; therefore, DOE
believes the stringency of the standards
is maintained for the market as a whole.
However, test data show that water
heaters do not all have the same
reaction to the new test procedure, and
as such, the relative difference in the
standards cannot be exactly maintained
for each individual model. In addition,
not all manufacturers rate models with
the same degree of conservativism, so
the relationship between rated and
measured values is not constant.
Regarding specifically the energy
conservation standards for the
residential-duty commercial water
heater equipment class, EEI stated that
this was a non-standard process for
creating the proposed standards. (EEI,
No. 5 at p. 2) In response, DOE clarifies
that DOE is not creating new standards
for residential-duty commercial water
heaters. Rather, this equipment has
always been covered under the
applicable commercial water heating
equipment standards. DOE is simply
translating the commercial water
heating equipment standards from the
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thermal efficiency and standby loss
metrics in use today to the UEF metric
for the subset of commercial water
heating equipment that would meet the
definition of a ‘‘residential-duty
commercial water heater’’ at 10 CFR
431.102.
a. Storage Volume Used for Calculations
In the July 2014 final rule, DOE
amended the certification requirements
for consumer water heaters to specify
that the rated storage volume of a water
heater is the mean of the measured
storage volume. 79 FR 40542, 40565
(July 11, 2014). Commenters requested
clarification on how the rated storage
volume will be applied in this
rulemaking. (AHRI, No. 3 at p. 2; A. O.
Smith, No. 13 at p. 2; Bradford White,
No. 14 at p. 3; NEEA, No. 15 at p. 7;
Rheem, No. 11 at p. 8)
As discussed in the preceding section,
DOE has accounted for the amended
certification requirements with regard to
the rated storage volume in this
rulemaking when translating the
standards. First, DOE used the rated
storage volumes prior to the effective
date of the requirement that the rated
storage volume of a water heater be the
mean of the measured storage volume to
calculate the EF-denominated standards
with which to maintain equivalency for
each model. Therefore, the stringency of
the EF-denominated standards that DOE
converted did not change due to the
new certification requirements. Second,
when calculating the converted UEF
standards equations, DOE adjusted the
rated storage volume to reflect its new
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products as high as possible—because
the applicable standard decreased for
larger volumes. The combined effect of
these two influences, DOE believes, is
that fossil-fuel-fired water heaters
ordinarily had volume ratings 5 percent
higher than their actual volumes, and
electric water heaters 10 percent higher.
DOE’s observations on actual products
is consistent with that conclusion.
Consequently, DOE estimated the
measured volume as 0.95 times (i.e., 5
percent lower than) the rated storage
volume for fossil fuel fired water heaters
and 0.90 times (i.e., 10 percent lower
than) the rated storage volume for
electric water heaters. By adjusting the
storage volume to reflect what will be
the new rated storage volumes that are
BILLING CODE 6150–01–P
the measurement is within 5 percent of
the certified rating. If the rated storage
volume is within 5 percent of the mean
of the measured value of storage
volume, then that value will be used as
In the July 2014 test procedure final
rule, DOE added enforcement
provisions that state that the rated value
for storage volume during enforcement
testing will be considered valid only if
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5 percent or 10 percent (for fossil fuel
and electric water heaters, respectively)
below the previous rated storage
volume, DOE has accounted for the
change in its regulations regarding the
rating of storage volumes, and the UEF
standard equation will represent the
relationship between the new rated
storage volume (equivalent to the mean
of the measured storage volume for test
samples) and UEF. Figure III.1 below
shows an example representation of
how the energy conservation standards
are related to each other based on the
rated or estimated measured storage
volumes.
BILLING CODE 6450–01–C
the basis for calculation of the required
uniform energy factor for the basic
model; otherwise, the mean of the
measured values will be used as the
basis for calculation of the required
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requirement that the rated storage
volume be equal to the mean of the
measured volume of units in the
certification sample (since the storage
volumes initially examined were
certified prior to the effective date of
this requirement).
Before DOE instituted this
requirement, a manufacturer had some
freedom to choose a volume rating,
subject to industry safety standards
under which a rated volume had to be
within 5 percent of the actual volume
for a fossil-fuel-fired water heater or
within 10 percent for an electric water
heater. Meanwhile, the operation of
DOE’s energy conservation standard for
water heaters gave manufacturers an
incentive to rate the volumes of their
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uniform energy factor for the basic
model. 79 FR 40542, 40566 (July 11,
2014); 10 CFR 429.134(d)(2). DOE
reviewed the measured storage volume
test data for models included in the
analysis for this SNOPR and observed
that for models which were tested more
than once, the measured storage volume
was well within five percent of the
mean of the measured storage volumes
(which will be required to be equal to
the rated storage volume under 10 CFR
429.17(a)(1)(ii)(C)) for each respective
model. The data set of models tested
more than once consists of 10 unique
models with 24 total storage volume
tests (each model was tested 2 or 3
times). For each model, DOE calculated
the mean, standard deviation, and 99.7percent confidence interval (i.e., 3 times
the standard deviation of the measured
storage volumes) of the measured
storage volumes. DOE then compared
the mean of the measured storage
volume to the 99.7-percent confidence
interval to determine the percent
deviation from the mean value that
would be within the 99.7-percent
confidence interval. The maximum
percent change from the mean that
would be within the 99.7-percent
confidence interval was slightly under
one percent. Therefore, DOE proposes to
change its enforcement-specific
provisions for water heaters to specify
that the rated value for storage volume
during enforcement testing will be
considered valid only if the
measurement is within 2 percent of the
certified rating. DOE believes two
percent more accurately reflects the
level of variability that manufacturers
are currently able to achieve, and allows
for slightly more variability than what
was observed in the sample set of this
SNOPR.
F. Compliance and Grandfathering
AHRI, Bradford White, Rheem, and
EEI recommended that DOE should add
provisions to state that any water heater
models tested and meeting the
minimum EF requirements prior to July
13, 2015 (i.e., those meeting the
standards promulgated in the April
2010 final rule and requiring
compliance on April 16, 2015), would
be considered as meeting the minimum
UEF requirements. (AHRI, No. 13 at p.
8; Bradford White, No. 14 at p. 2;
Rheem, No. 11 at p. 3; EEI, No. 17 at p.
3) AHRI, Bradford White, and EEI stated
that the proposed standards are to be
neither more nor less stringent than the
EF-denominated standards, as stated in
42 U.S.C. 6293(e), and that this implies
grandfathering water heater models will
be included in this rulemaking. (AHRI,
No. 13 at p. 8; Bradford White, No. 14
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at p. 1; EEI, No. 17 at p. 3) Further,
Rheem argued that at the time of the
switch from allowing the converted UEF
to requiring the tested UEF for
demonstrating compliance, a tested UEF
value should comply if the converted
value passes. (Rheem, No. 11 at p. 5) EEI
asserted that compliance or noncompliance with the standard can only
be determined through the test
procedure and that a unit which meets
the efficiency standard under the old
test procedure should be valid for sale,
regardless of the conversion factor
result. (EEI, No. 17 at p. 3) EEI also
argued that the conversion values
should only be used on the FTC
EnergyGuide label. (EEI, No. 17 at p. 3)
AHRI stated that the converted
minimum UEF standards will not have
perfect one-to-one correlation with
every currently complying model, and
therefore, it is essential that DOE
establish how grandfathering will be
applied so that manufacturers can
properly assess the validity of the
converted minimum UEF standards.
(AHRI, No. 13 at p. 8)
In a paragraph titled ‘‘Existing
covered water heaters,’’ EPCA provides
that a covered water heater (i.e., a water
heater subject to the UEF test procedure
rule) is considered to comply with the
UEF test procedure rule on and after the
effective date of the final rule (i.e., July
13, 2015) and with any revised labeling
requirements established by the Federal
Trade Commission (FTC) to carry out
the final rule if the covered water heater
was manufactured prior to the effective
date of the final rule; and (ii) complied
with the efficiency standards and
labeling requirements in effect prior to
the final rule. (42 U.S.C. 6295(e)(5)(K))
EPCA defines the ‘‘final rule,’’ in this
context, to be the UEF test procedure
final rule. (42 U.S.C. 6295(e)(5)(A)(ii))
The natural reading of this provision is
that a water heater (a unit 21)
manufactured prior to July 13, 2015, and
compliant with the pre-existing
standards when tested using the test
procedure in effect on July 13, 2014, is
deemed to comply with the UEF test
procedure final rule and any
corresponding label changes made by
the FTC.
Manufacturers appear to read this
provision to provide ‘‘grandfathering’’
with respect to compliance with the
converted standards. The language does
not provide such relief, nor is such
relief necessary. The standard
applicable to a unit is the standard in
21 DOE notes that EPCA appears to distinguish in
paragraph (e)(5) of section 6295 between certain
provisions that apply on a unit-by-unit basis and
other provisions that apply on a model-by-model
basis.
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effect at the time of manufacture;
therefore, units manufactured prior to
July 13, 2015, must comply with the
corresponding EF/TE/STB standards,
and no ‘‘grandfathering’’ is needed. The
relevance of the UEF test procedure
with respect to such units is for the
purposes of representations, which this
statutory provision explicitly addresses.
Accordingly, DOE reads 42 U.S.C.
6295(e)(5)(K) to provide that
manufacturers do not have to retest
units of water heaters using the UEF test
procedure if they were tested and rated
prior to July 13, 2015. DOE notes there
is a corresponding provision with
respect to the FTC label.
In addition, EPCA provides that
manufacturers may use the conversion
factor in lieu of testing for models tested
prior to July 13, 2015, for a period of
one year following the publication of a
final rule. In this way, EPCA provides
additional relief to manufacturers for
models of water heaters that continue to
be manufactured on or after July 13,
2015, by delaying the need to complete
testing using the UEF test procedure for
those models of water heaters
manufactured prior to July 13, 2015. See
42 U.S.C. 6295(e)(5)(E) (indicating the
conversion factor applies to ‘‘models of
covered water heaters’’ (emphasis
added)); compare 42 U.S.C.
6295(e)(5)(K) (referring to ‘‘existing
covered water heaters’’ and ‘‘a covered
water heater’’ rather than a ‘‘model of
covered water heater’’).
DOE recognizes that the nature of this
conversion process could conceivably
result in a few models very close to the
standard falling below the converted
standard. Although the statute does not
provide ‘‘grandfathering’’ of the sort
envisioned by manufacturers, DOE
believes that there is value in reducing
the uncertainty for manufacturers and
that there is no significant public harm
in letting manufacturers continue sales
of certain models. As discussed in great
detail throughout this notice, every
model responds slightly differently to
the change in the test procedure. As a
result, there is variability, and units
very near the standard level (either
above or below) could have a measured
efficiency using the new test procedure
that would change the compliance
status of that unit. Accordingly, DOE
will determine the compliance of a basic
model—the level of granularity typically
used by DOE and manufacturers to
evaluate compliance—using the test
procedure in effect prior to July 13,
2015, under the following circumstance:
The basic model must have been in
distribution in commerce prior to July
13, 2015; the basic model must have
been tested and properly certified to
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DOE as compliant with the applicable
standard prior to July 13, 2015; and the
units manufactured prior to July 13,
2015, must be essentially identical to
the units manufactured on or after July
13, 2015. The last requirement for this
policy—that units must be essentially
identical—bears explanation. DOE
generally permits manufacturers great
latitude in assigning basic model
numbers, and manufacturers normally
are not required to certify a model as a
new basic model if modifications make
the model more efficient. In
implementing this policy, DOE believes
that, if a manufacturer makes changes to
a model (that make it either more
efficient or less), then it should conduct
the requisite testing using the UEF test
procedure and ensure the compliance of
the model with the converted standard.
This policy is intended to give certainty
to manufacturers with respect to
historical models; it is not intended to
provide a mechanism to perpetuate an
obsolete test method and obsolete
metrics.
In summary, EPCA provides that units
of water heaters can continue to have
their efficiency represented in terms of
the ‘‘old’’ metrics. EPCA also provides
that manufacturers can use the
conversion factors to determine
represented values for a period of one
year following issuance of a final rule in
this rulemaking for models that were
being manufactured prior to July 13,
2015. Under EPCA, units manufactured
on or after July 13, 2015, must meet the
standard as denominated in the UEF
metric; however, DOE will implement
an enforcement policy that DOE will not
seek civil penalties for the continued
manufacture and distribution in
commerce of units of certain basic
models as follows: The basic model
must have been in distribution in
commerce prior to July 13, 2015; the
basic model must have been tested and
properly certified to DOE as compliant
with the applicable standard prior to
July 13, 2015; and the units
manufactured prior to July 13, 2015,
must be essentially identical to the units
manufactured on or after July 13, 2015.
DOE recognizes that manufacturers
seek certainty that models introduced
since July 13, 2015, will not be subject
to civil penalties. In enforcing the
standard(s), DOE will consider whether
these models meet the standard(s) as
denoted using the ‘‘old’’ metric(s), the
deviation from the UEF standard when
tested using the UEF test procedure, and
efforts taken by the manufacturer to
ensure compliance with the converted,
UEF standards. DOE does not intend to
issue a ‘‘grandfathering’’ enforcement
policy with respect to basic models
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introduced on and after July 13, 2015,
as such a policy does not appear to be
necessary at this time.
G. Certification
EPCA requires that the standard for
covered water heaters be in terms of
UEF as of July 13, 2015. Accordingly, in
the April 2015 NOPR, DOE proposed to
require manufacturers to provide EF and
UEF for consumer water heaters (or
thermal efficiency and standby loss and
UEF for residential-duty commercial
water heaters) in certification reports
filed between July 13, 2015, and the
compliance date determined by the final
rule in this rulemaking. 80 FR 20116,
20138 (April 14, 2015). DOE proposed
that manufacturers would not be
required to submit revised certification
reports for previously certified basic
models until the next annual
certification date (May 1). Id.
In the April 2015 NOPR, DOE noted
that 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. DOE stated that
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. Lastly, DOE stated that it
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.
Id.
In his comments, Lutz requested that
standby heat loss coefficient (UA),
Annual Energy Consumption (Eannual),
Annual Electrical Energy Consumption
(Eannual,e), and Annual Fossil Fuel Energy
Consumption (Eannual,f) be included in
the parameters manufacturers are
required to submit to DOE and further
that they be available to the public in
the Compliance Certification Database.
Lutz stated that these parameters are
already calculated during the UEF test
procedure and would help analysts
estimate energy consumption of water
heaters when operating under
conditions that do not exactly match the
draw patterns or other conditions
specified in the laboratory test
procedure. (Lutz, No. 20 at p. 1) DOE
has tentatively decided not to add these
values as part of the certification report;
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however, DOE is specifically requesting
comment from stakeholders about
whether these performance
characteristics should be added in the
final rule, either as publicly reported
characteristics of water heaters or as
information that is not published on the
DOE Web site.
AHRI, A.O. Smith, and Rheem
commented that DOE should delay the
effective date of the uniform energy
descriptor test procedure. (AHRI, No. 13
at p. 3; A.O. Smith, No. 10 at pp. 1–2;
Rheem, No. 11 at p. 10) Specifically,
AHRI argued that the statutory timeline
cannot override the substantive
statutory protections that Congress
provided, and it is imperative that DOE
take the time and effort to conduct the
testing and analysis necessary to ensure
that the statutory requirements are met.
AHRI also stated that to proceed with
implementing the UED test procedure
on July 13, 2015, without the existence
of appropriate conversion factors, would
violate the statute and serve no purpose
except to further confuse an already
complex situation. (AHRI, No. 13 at pp.
2–3) A.O. Smith urged the
postponement of the implementation
date because new models would be
tested to the new test method and have
a valid UEF rating, but without a valid
conversion factor in place to convert the
relevant minimum efficiency
requirement into terms of UEF, there is
no basis for determining whether the
new model is compliant with minimum
efficiency standards. (A.O. Smith, No.
10 at pp. 1–2) Rheem stated that new
consumer water heater models
introduced in the time period between
the compliance date of the amended test
procedure and the conversion of the
minimum standards will have to be
certified with the UEF descriptor in
accordance with the UEF test procedure
rule, but there will be no established
minimum UEF standard for that model
to achieve. Rheem asserted that such
uncertainty will prevent the launch of
new consumer water heater models and
cause significant harm to Rheem and its
customers. Rheem requested a delay in
implementation of the uniform energy
descriptor to permit the necessary
changes to product and carton labeling
and communications that display
energy efficiency metrics for all
manufactured consumer and residentialduty commercial water heater units.
(Rheem, No. 11 at pp. 9–10). NEEA
strongly supported the Department’s
proposal to defer re-certification of
existing water heater models until May
2016, noting that manufacturers would
need time to transition to the UEF
testing and/or calculation regime
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specified as a result of this rulemaking.
(NEEA, No. 15 at p. 7)
Several commenters also cited the
complexities of coordinating the DOE
metric change with the FTC labelling
process, and argued that the need for
coordination with FTC should delay the
implementation of the uniform
efficiency descriptor. A.O. Smith stated
the need to coordinate FTC labeling
rules with the UEF requirements as a
reason to delay implementation, and
elaborated that without a valid set of
conversion factors, a manufacturer will
not be able to ‘‘back calculate’’ cost of
operation for the FTC label from a tested
UEF. (A.O. Smith, No. 10 at p. 2) GE
commented that DOE should harmonize
with the FTC labeling process, and fully
implement the UEF and conversion
once the FTC label has been modified to
account for the different usage patterns
in the UEF test method. (GE, No. 12 at
p. 2) Rheem recommended postponing
the adoption of reporting requirements
until FTC has had an opportunity to
evaluate the EnergyGuide label and
revise its format to reflect the metrics
derived from the UEF. Rheem noted that
the FTC label requires information
based on the measurement of EF and
that a conversion method would be
needed to calculate the EF based on the
UEF. Rheem stated that such
conversions for marketing and labeling
materials will result in displays of
performance and cost metrics based
upon two different energy efficiency
descriptors, which will confuse
consumers. Rheem also raised concerns
that the differences in energy and water
consumption based on the delivery
capacity in the UEF test method will
lead to differences in annual operating
costs reported on the label, which could
create an incentive for manufacturers to
display the information based on UEF
for low and medium usage water heaters
in order to display expected lower
operating costs. (Rheem, No. 11 at p. 9)
AHRI stated that, after the compliance
date of the UEF test procedure, DOE
will require manufacturers to certify
UEF values, but for the FTC label,
manufacturers must also have EF-based
information. Although DOE had
proposed not to require updated
certification reports containing
represented values for UEF until May 1,
2016, AHRI asserted that to comply with
the information requirements of EPCA
under section 6293(c), manufacturers
must provide the market with UEFbased information. AHRI stated that
FTC enforces both the EnergyGuide
information and general manufacturer
claims regarding their products under
the unfair and deceptive trade practices
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provisions pursuant to section 6303(c),
and if manufacturers display
information not in conformance with
Federally-mandated test procedures,
this may be considered a deceptive
trade practice. (AHRI, No. 13 at p. 2)
DOE understands the difficulties
created by the timing of both the
uniform efficiency descriptor
rulemaking and the present conversion
factor rulemaking for covered water
heaters. However, these rulemakings
dealt with matters of significant
complexity and necessitated a
substantial amount of testing to ensure
the accuracy and validity of results, as
reflected by requests from industry for
extended comment periods and
additional DOE testing. Consequently,
DOE was not able to meet the regulatory
timeline envisioned by Congress, and as
a result, the Department seeks to
alleviate any hardships raised by the
current timeline.
Upon the effective date of the final
rule that results from this rulemaking,
certification of compliance with energy
conservation standards will be
exclusively in terms of UEF. DOE has
tentatively concluded that there will be
three possible paths available to
manufacturers for certifying compliance
of basic models of consumer water
heaters that were certified before July
13, 2015: (1) In the year following the
final rule in this rulemaking, convert the
energy factor values 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 from
energy factor to uniform energy factor
using the applicable mathematical
conversion factor, and then use the
converted uniform energy factors along
with the applicable sampling provisions
in 10 CFR part 429 to determine the
represented uniform energy 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 paths available to
manufacturers for certifying compliance
of basic models of commercial
residential-duty water heaters that were
certified before July 13, 2015: (1) In the
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year following the final rule in this
rulemaking, convert the thermal
efficiency and standby loss values
obtained using the test procedure
contained in 10 CFR 431.106 of the
January 1, 2015 edition of the CFR from
thermal efficiency and standby loss to
uniform energy factor using the
applicable mathematical conversion
factor, and then use the converted
uniform energy factors along with the
applicable sampling provision in 10
CFR part 429 to determine the
represented uniform energy 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.
DOE has already issued an
enforcement policy not to seek civil
penalties for certification violations
during the pendency of this rulemaking.
Under that policy, manufacturers are
not held accountable for submitting
certification reports until a conversion
factor final rule is published. DOE
intends to extend the certification
portion of that policy for an appropriate
time period to allow manufacturers to
certify compliance using the conversion
factors. DOE notes that certification of
basic models that were certified prior to
July 13, 2015, will only require the
application of the appropriate
conversion formula(s) from the final
rule and, thus, should not require a
significant amount of time to complete
certification. As the test procedure has
been final for more than a year, DOE
also expects that the time to complete
certification for basic models introduced
after July 13, 2015, will not be
significant. DOE welcomes data from
industry regarding the necessary time to
submit such reports.
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
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(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 on a limited basis to determine the
represented values 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
energy factor, thermal efficiency, and
standby loss test procedures (as
applicable) and the uniform energy
factor test procedure. 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), at 77
FR 49991, 50008–11 (August 20, 2012),
and at 81 FR 4469, 4490 (Jan. 26, 2016),
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/sites/default/files/files/
Size_Standards_Table.pdf. Consumer
water heater manufacturing is classified
under NAICS code 335228—’’Other
Major Household Appliance
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Manufacturing.’’ The SBA sets a
threshold of 1,000 employees or less for
an entity to be considered as a small
business. Commercial water heater
manufacturing is classified under
NAICS code 333318—‘‘Other
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 11 manufacturers
of consumer water heaters that can be
considered small businesses. DOE
identified five manufacturers of
‘‘residential-duty’’ commercial water
heaters that can be considered small
businesses. Four of the ‘‘residentialduty’’ commercial water heater
manufacturers also manufacture
consumer water heaters, so the total
number of small water heater
manufacturers impacted by this rule
would be 12. DOE’s research involved
reviewing several industry trade
association membership directories
(e.g., AHRI), product databases (e.g.,
CCMS, 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 energy factor test
procedure and energy conservation
standards, the conversion factor in this
proposed rule would convert the rated
values based on the energy factor test
procedure to values based on the
uniform energy factor test procedure.
Likewise, 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 previous test
procedure to the uniform descriptor
which is based on the UEF test
procedure. The energy conservation
standards for commercial water heating
equipment will be denominated using
the uniform descriptor.
The conversion factor proposal
accomplishes two tasks: (1) Translating
the EF-, TE-, and SL-denominated (as
applicable) energy conservation
standards for consumer water heaters
and certain commercial water heaters to
being expressed in terms of the metric
and test procedure for uniform energy
factor; and (2) providing a limited
conversion factor that manufacturers
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can use to translate represented values
established for basic models certified
prior to July 13, 2015. This limited
conversion is a burden-reducing
measure which helps to ease the
transition of the market to the new test
procedure and uniform metric over the
one-year period instead of the typical
180 day timeframe allotted by statute. In
addition, as discussed in section III.F,
DOE will implement an enforcement
policy that DOE will not seek civil
penalties for the continued manufacture
and distribution in commerce of units of
certain basic models that meet certain
conditions (as described in III.F),
thereby further reducing any burden on
small business manufacturers.
Accordingly, DOE concludes and
certifies that this rule, if finalized,
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 was
approved by OMB under OMB control
number 1910–1400, and this
conversion-factor rule does not
constitute a significant change to the
requirement. 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
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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 prior efficiency and delivery
capacity metrics (and related energy
conservation standard requirements) for
consumer and certain commercial water
heaters to the uniform efficiency
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
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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
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
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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-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 (Public Law 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
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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.
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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
(Public Law 93–275), as amended by the
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Federal Energy Administration
Authorization Act of 1977 (Public Law
95–70). (15 U.S.C. 788; FEAA) Section
32 essentially provides in relevant part
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 supplemental
proposed rule, no later than the date
provided in the DATES section at the
beginning of this SNOPR. 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.
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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
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10 CFR Part 431
¯
and, x is the sample mean; n is the
number of samples; and xi is the ith
sample;
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VI. Approval of the Office of the
Secretary
The Secretary of Energy has approved
publication of this supplemental 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.
Administrative practice and
procedure, Confidential business
information, Test procedures,
Incorporation by reference, Reporting
and recordkeeping requirements.
Or,
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Issued in Washington, DC, on August 15,
2016.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy
Efficiency, Energy Efficiency and Renewable
Energy.
For the reasons stated in the
preamble, DOE proposes 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; 28 U.S.C.
2461 note.
2. Section 429.17 is revised to read as
follows:
■
§ 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
energy consumption or other measure of
energy use 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:
(2) The upper 95-percent confidence
limit (UCL) of the true mean divided by
1.10, where
Fmt 4701
Sfmt 4725
E:\FR\FM\30AUP2.SGM
30AUP2
EP30AU16.040</GPH>
1. Is DOE’s method of applying the
regression for electric storage water
heaters with storage volumes at or
below 55 gallons in developing the
conversion equation for grid-enabled
water heaters appropriate?
2. Is DOE’s use of the standard and
low-NOX conversion to calculate the
energy conservation standard for
consumer gas-fired storage water heaters
less than or equal to 55 gallons, and its
tentative decision not to propose
separate standards for ultra-low-NOX
gas-fired storage water heaters
appropriate?
3. Are DOE’s assumptions for the
typical input rating and recovery
efficiency of consumer gas-fired storage
water heaters above 55 gallons
appropriate?
4. Is DOE’s approach for estimating
the recovery efficiency of a minimallycompliant (i.e., 0.93 EF) electric
instantaneous water heater appropriate?
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:
mstockstill on DSK3G9T082PROD with PROPOSALS2
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).
EP30AU16.039</GPH>
59792
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
¯
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).
(B) Any represented value of energy
efficiency or other measure of energy
consumption of a basic model for which
¯
and, x is the sample mean; n is the
number of samples; and x i is the i th
sample;
Or,
¯
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).
(C) 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.
(D) Any represented value of firsthour 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.
(2) For basic models initially certified
before July 13, 2015 (using either the
energy factor test procedure contained
59793
consumers would favor higher values
shall be less than or equal to the lower
of:
(1) The mean of the sample, where:
(2) The lower 95-percent confidence
limit (LCL) of the true mean divided by
0.90, where:
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) Determine the represented value
for each basic model 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 of
paragraph (a)(1); or
(ii) Calculate the uniform energy
factor for each test sample by applying
the following mathematical conversion
factors to test data previously obtained
through testing according to 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.
Represented values of uniform energy
factor, first-hour rating, and maximum
GPM rating based on a calculation using
this mathematical conversion factor
must be determined using the
applicable sampling provisions in
paragraphs (a)(1)(i) and (a)(1)(ii) of this
section.
(A) The applicable mathematical
conversion factors are as follows:
Conversion factor *
Consumer Gas-fired Water Heater ...................
Non-Condensing, Standard and Low NOX ......
New FHR = 7.9592 + 0.8752 × FHRP.
New UEF = ¥0.0002 + 0.9858 × UEFWHAM.
New FHR = 25.0680 + 0.6535 × FHRP.
New UEF = 0.0746 + 0.8653 × UEFWHAM.
New FHR = 1.0570 × FHRP.
New UEF = 0.4242 + 0.4641 × UEFWHAM.
New FHR = 1.1012 × FHRP.
New UEF = ¥0.0934 + 1.1144 × UEFWHAM.
New FHR = 9.2827 + 0.8092 × FHRP.
New UEF = 0.4774 + 0.4740 × UEFWHAM.
New FHR = ¥4.2705 + 0.9947 × FHRP.
New UEF = 0.1513 + 0.8407 × EF + 0.0043 ×
DV.
New FHR = 41.5127 + 0.1989 × FHRP.
New UEF = ¥0.3305 + 1.3983 × UEFWHAM.
New Max GPM = 1.1461 × Max GPMP.
New UEF = 0.1006 + 0.8622 × UEFmodel.
New Max GPM = 1.1461 × Max GPMP.
New UEF = 0.9847 × UEFmodel.
New FHR = 9.2827 + 0.8092 × FHRP.
New UEF = 0.4774 + 0.4740 × UEFWHAM.
New FHR = ¥35.8233 + 0.4649 × Vr +
160.5089 × Et.
New UEF = ¥0.0022 + 1.0002 × UEFrd.
New FHR = ¥35.8233 + 0.4649 × Vr +
160.5089 × Et.
New UEF = ¥0.0022 + 1.0002 × UEFrd.
Non-Condensing, Ultra-Low NOX ....................
Condensing ......................................................
Consumer Oil-fired Water Heater ......................
N/A ....................................................................
Consumer Electric Water Heater ......................
Electric Resistance ...........................................
Heat Pump .......................................................
N/A ....................................................................
Instantaneous Gas-fired Water Heater .............
mstockstill on DSK3G9T082PROD with PROPOSALS2
Tabletop Water Heater ......................................
N/A ....................................................................
Instantaneous Electric Water Heater ................
N/A ....................................................................
Grid-Enabled Water Heater ...............................
N/A ....................................................................
Residential-Duty Commercial Gas-fired Water
Heater.
N/A ....................................................................
Residential-Duty Commercial Oil-fired Water
Heater.
N/A ....................................................................
VerDate Sep<11>2014
21:44 Aug 29, 2016
Jkt 238001
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Fmt 4701
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E:\FR\FM\30AUP2.SGM
30AUP2
EP30AU16.042</GPH>
Distinguishing criteria
EP30AU16.041</GPH>
Product class
59794
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
Product class
Distinguishing criteria
Conversion factor *
Residential-Duty Commercial Electric Instantaneous Water Heater.
N/A ....................................................................
New Max GPM = 0.0146 + 0.0295 × Q.
New UEF = UEFrd, model.
* FHRP = prior first-hour rating.
Max GPMP = prior max GPM rating.
Q = nameplate input rate, in kBtu/h.
Et = thermal efficiency rating.
UEFWHAM = the UEF predicted based on the WHAM equation for consumer storage water heaters, as defined in paragraph (a)(2)(ii)(B) of this
section.
UEFrd = the modified WHAM for residential-duty commercial water heaters, as defined in paragraph (a)(2)(ii)(B) of this section.
UEFmodel = the UEF predicted based on the analytical model developed by DOE for consumer instantaneous water heaters, as defined in paragraph (a)(2)(ii)(B) of this section.
UEFrd model = the UEF predicted based on the analytical model developed by DOE for residential-duty commercial instantaneous water heaters, as defined in paragraph (a)(2)(ii)(B) of this section.
DV = drawn volume of water in UEF simulated-use test.
Vr = rated storage volume in gallons.
(B) Calculate UEFWHAM (for consumer
storage water heaters), UEFmodel (for
consumer instantaneous water heaters),
UEFrd (for residential-duty commercial
storage water heaters), and UEFrd, model
(for residential-duty commercial electric
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
energy factor; hr is the recovery
efficiency in decimal form; and P is the
input rate in Btu/h.
Draw pattern
a
Very Small .......................................................................................................
Low ..................................................................................................................
Medium ............................................................................................................
High ..................................................................................................................
b
0.250266
0.065860
0.045503
0.029794
c
57.5
57.5
57.5
57.5
d
0.039864
0.039864
0.039864
0.039864
67.5
67.5
67.5
67.5
(2) For consumer instantaneous water
heaters:
VerDate Sep<11>2014
21:44 Aug 29, 2016
Jkt 238001
A
Draw pattern
Very Small ........
Low ...................
Medium .............
0.003819
0.001549
0.001186
Draw pattern
F
Very Small ........
Low ...................
Medium .............
PO 00000
Frm 00060
0.821429
0.821429
0.821429
Fmt 4701
Sfmt 4702
Gas
0.026915
0.010917
0.008362
G
0.0043520
0.0011450
0.0007914
Electric
High ..................
0.000785
Gas
0.005534
(3) For residential-duty commercial
storage water heaters:
Draw pattern
High ..................
F
0.821429
G
0.0005181
(4) For residential-duty commercial
electric instantaneous water heaters:
E:\FR\FM\30AUP2.SGM
30AUP2
EP30AU16.045</GPH>
Electric
EP30AU16.044</GPH>
Where P is the input rate in Btu/h; Et
is the thermal efficiency; SL is the
standby loss in Btu/h; and F and G are
coefficients as specified in the table
below based on the applicable draw
pattern.
A
Draw pattern
EP30AU16.043</GPH>
mstockstill on DSK3G9T082PROD with PROPOSALS2
Where hr is the recovery efficiency
expressed in decimal form and A is
dependent upon the applicable draw
pattern and fuel type as specified in the
table below.
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
21:44 Aug 29, 2016
Jkt 238001
PO 00000
Frm 00061
Fmt 4701
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¯
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:
E:\FR\FM\30AUP2.SGM
30AUP2
EP30AU16.049</GPH>
¯
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).
(C) 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.
(D) Any represented value of firsthour rating or maximum gallons per
EP30AU16.048</GPH>
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:
EP30AU16.050</GPH>
¯
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).
(B) Any represented value of the
uniform 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:
EP30AU16.047</GPH>
mstockstill on DSK3G9T082PROD with PROPOSALS2
VerDate Sep<11>2014
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:
EP30AU16.046</GPH>
gpm) as determined under-paragraph
(a)(2)(ii)(A) of this section, the
previously certified maximum gallons
per minute (gpm, rounded to the nearest
0.1 gpm) under the energy factor test
Draw pattern
A
procedure, and the recovery efficiency
in percent (%, rounded to the nearest
Very Small ................................
0.003819
1%); and
Low ...........................................
0.001549
(iv) For instantaneous-type water
Medium .....................................
0.001186
High ..........................................
0.000785 heater basic models rated pursuant to 10
CFR 429.17(a)(1) or 10 CFR
(b) Certification reports.
429.17(a)(2)(i): The uniform energy
(1) The requirements of 10 CFR
factor (UEF, rounded to the nearest
429.12 apply; and
0.01), the rated storage volume in
(2) Pursuant to 10 CFR 429.12(b)(13),
gallons (gal, rounded to the nearest 1
a certification report must include the
gal), the maximum gallons per minute
following public product-specific
(gpm, rounded to the nearest 0.1 gpm),
information:
and the recovery efficiency in percent
(i) For storage-type water heater basic (%, rounded to the nearest 1%).(the
models previously certified for energy
uniform energy factor test procedure
factor pursuant to § 429.17(a) of the
first-hour rating in gallons (gal, rounded
January 1, 2015 edition of the Code of
to the nearest 1 gal) as determined
Federal Regulations, and for which
under paragraph (a)(2)(ii)(A) of this
uniform energy factor is calculated
section,
pursuant to 10 CFR 429.17(a)(2)(ii): The
(v) For grid-enabled water heater basic
energy factor (EF, rounded to the nearest
models rated pursuant to 10 CFR
0.01), the uniform energy factor (UEF,
429.17(a)(1) or 10 CFR 429.17(a)(2)(i):
rounded to the nearest 0.01), the rated
The uniform energy factor (UEF,
storage volume in gallons (gal, rounded
rounded to the nearest 0.01), the rated
to the nearest 1 gal), the uniform energy
storage volume in gallons (gal, rounded
factor test procedure first-hour rating in
to the nearest 1 gal), the first-hour rating
gallons (gal, rounded to the nearest 1
in gallons (gal, rounded to the nearest 1
gal) as determined under paragraph
gal), and the recovery efficiency in
(a)(2)(ii)(A) of this section, the
percent (%, rounded to the nearest 1%),
previously certified first-hour rating
a declaration that the model is a gridunder the energy factor test procedure
enabled water heater, whether it is
in gallons (gal, rounded to the nearest 1
equipped at the point of manufacture
gal), and the recovery efficiency in
percent (%, rounded to the nearest 1%); with an activation lock, and whether it
(ii) For storage-type water heater basic bears a permanent label applied by the
manufacturer that advises purchasers
models rated pursuant to 10 CFR
and end-users of the intended and
429.17(a)(1) or 10 CFR 429.17(a)(2)(i):
appropriate use of the product.
The uniform energy factor (UEF,
3. Section 429.17 is further revised,
rounded to the nearest 0.01), the rated
proposed to be effective (date one year
storage volume in gallons (gal, rounded
to the nearest 1 gal), the first-hour rating after publication of test procedure final
rule), to read as follows:
in gallons (gal, rounded to the nearest 1
gal), and the recovery efficiency in
§ 429.17 Water heaters.
percent (%, rounded to the nearest 1%);
(a) Determination of represented
(iii) For instantaneous-type water
value.
heater basic models previously certified
(1) Manufacturers must determine the
for energy factor pursuant to § 429.17(a)
represented value for each water heater
of the January 1, 2015 edition of the
by applying an AEDM in accordance
Code of Federal Regulations, and for
with 10 CFR 429.70 or by testing for the
which uniform energy factor is
uniform energy factor, in conjunction
calculated pursuant to 10 CFR
with the applicable sampling provisions
429.17(a)(2)(ii): The energy factor (EF,
as follows:
rounded to the nearest 0.01), the
(i) If the represented value is
uniform energy factor (UEF. rounded to
determined through testing, the general
the nearest 0.01), the rated storage
requirements of 10 CFR 429.11 are
volume in gallons (gal, rounded to the
nearest 1 gal), the uniform energy factor applicable; and
test procedure maximum gallons per
(ii) For each basic model selected for
minute (gpm, rounded to the nearest 0.1 testing, a sample of sufficient size shall
Where Et is the thermal efficiency
expressed in decimal form and A is
dependent upon the applicable draw
pattern, as specified in the table below.
59795
59796
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
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: The uniform energy factor
(UEF, rounded to the nearest 0.01), the
rated storage volume in gallons
(rounded to the nearest 1 gal), the firsthour rating in gallons (gal, rounded to
the nearest 1 gal), the recovery
efficiency in percent (%, rounded to the
nearest 1%);
(ii) For instantaneous-type water
heater basic models: The uniform
energy factor (UEF, rounded to the
nearest 0.01), the rated storage volume
in gallons (gal, rounded to the nearest 1
gal), the maximum gallons per minute
(gpm, rounded to the nearest 0.1 gpm),
the recovery efficiency in percent (%,
rounded to the nearest 1%); and
(iii) For grid-enabled water heater
basic models: The uniform energy factor
(UEF, rounded to the nearest 0.01), the
rated storage volume in gallons (gal,
rounded to the nearest 1 gal), the firsthour rating in gallons (gal, rounded to
the nearest 1 gal), the recovery
efficiency in percent (%, rounded to the
nearest 1%), a declaration that the
model is a grid-enabled water heater,
whether it is equipped at the point of
manufacture with an activation lock,
and whether it bears a permanent label
applied by the manufacturer that
advises purchasers and end-users of the
intended and appropriate use of the
product.
■ 4. Section 429.44 is amended by
revising paragraph (d) [proposed at 81
FR 28588, 28636 (May 9, 2016)] to read
as follows:
§ 429.44 Commercial water heating
equipment.
mstockstill on DSK3G9T082PROD with PROPOSALS2
*
*
*
*
*
(d) Certification reports for
residential-duty commercial water
heaters.
(1) The requirements of § 429.12
apply; and
(2) Pursuant to § 429.12(b)(13), a
certification report must include the
following public equipment-specific
information:
(i) Residential-duty commercial gasfired and oil-fired storage water heaters
previously certified for thermal
efficiency and standby loss pursuant to
VerDate Sep<11>2014
21:44 Aug 29, 2016
Jkt 238001
10 CFR 429.44(b) of the January 1, 2015
edition of the Code of Federal
Regulations, and for which uniform
energy factor is calculated pursuant to
10 CFR 429.17(a)(2)(ii): The thermal
efficiency in percent (%), the standby
loss in British thermal units per hour
(Btu/h), the uniform energy factor (UEF,
rounded to the nearest 0.01), the rated
storage volume in gallons (gal), and the
nameplate input rate in Btu/h.
(ii) Residential-duty commercial gasfired and oil-fired storage water heaters
rated for uniform energy factor pursuant
to 10 CFR 429.17(a)(2)(i): The uniform
energy factor (UEF, rounded to the
nearest 0.01), the rated storage volume
in gallons (rounded to the nearest 1 gal),
the first-hour rating in gallons (gal,
rounded to the nearest 1 gal), and the
recovery efficiency in percent (%,
rounded to the nearest 1%).
(iii) Residential-duty commercial
electric instantaneous water heaters
previously certified for thermal
efficiency and standby loss pursuant to
10 CFR 429.44(b) of the January 1, 2015
edition of the Code of Federal
Regulations, and for which uniform
energy factor is calculated pursuant to
10 CFR 429.17(a)(2)(ii): The thermal
efficiency in percent (%), the standby
loss in British thermal units per hour
(Btu/h), the uniform energy factor (UEF,
rounded to the nearest 0.01), the rated
storage volume in gallons (gal), and the
nameplate input rate in kilowatts (kW).
(iv) Residential-duty commercial
electric instantaneous water heaters
rated for uniform energy factor pursuant
to 10 CFR 429.17(a)(2)(i): The uniform
energy factor (UEF, rounded to the
nearest 0.01), the rated storage volume
in gallons (gal, rounded to the nearest 1
gal), the maximum gallons per minute
(gpm, rounded to the nearest 0.1 gpm),
and the recovery efficiency in percent
(%, rounded to the nearest 1%)).
*
*
*
*
*
■ 5. Section 429.44 is further amended,
proposed to be effective (date one year
after publication of test procedure final
rule), by revising paragraph (d)(2) to
read as follows:
§ 429.44 Commercial water heating
equipment.
*
*
*
*
*
(d) * * *
(2) Pursuant to § 429.12(b)(13), a
certification report for equipment must
include the following public equipmentspecific information:
(i) Residential-duty commercial gasfired and oil-fired storage water heaters:
The uniform energy factor (UEF,
rounded to the nearest 0.01), the rated
storage volume in gallons (gal, rounded
to the nearest 1 gal), the first-hour rating
PO 00000
Frm 00062
Fmt 4701
Sfmt 4702
in gallons (gal, rounded to the nearest 1
gal), and the recovery efficiency in
percent (%, rounded to the nearest 1%).
(ii) Residential-duty commercial
electric instantaneous water heaters:
The uniform energy factor (UEF,
rounded to the nearest 0.01), the rated
storage volume in gallons (gal, rounded
to the nearest 1 gal), the maximum
gallons per minute (gpm, rounded to the
nearest 0.1 gpm), and the recovery
efficiency in percent (%, rounded to the
nearest 1%).
*
*
*
*
*
■ 6. Section 429.134 is revised by
amending paragraph (d)(2) to read as
follows:
§ 429.134 Product-specific enforcement
provisions.
*
*
*
*
*
(d) * * *
(2) Verification of rated storage
volume. The storage volume of the basic
model will be measured pursuant to the
test requirements of appendix E to
subpart B of 10 CFR part 430 for each
unit tested. The mean of the measured
values will be compared to the rated
storage volume as certified by the
manufacturer. The rated value will be
considered valid only if the
measurement is within two percent of
the certified rating.
(i) If the rated storage volume is found
to be within 2 percent of the mean of the
measured value of storage volume, then
the rated value will be used as the basis
for calculation of the required uniform
energy factor for the basic model.
(ii) If the rated storage volume is
found to vary more than 2 percent from
the mean of the measured values, then
the mean of the measured values will be
used as the basis for calculation of the
required uniform energy factor for the
basic model.
*
*
*
*
*
PART 430—ENERGY CONSERVATION
PROGRAM FOR CONSUMER
PRODUCTS
7. The authority citation for part 430
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6309; 28 U.S.C.
2461 note.
8. 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 is calculated as—
E:\FR\FM\30AUP2.SGM
30AUP2
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
(A) For a gas-fired or oil-fired 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. Round the
resulting product to the nearest dollar
per year.
(B) For an electric water heater, the
product of the annual energy
consumption, determined according to
section 6.1.8 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. Round the
resulting quotient to the nearest dollar
per year.
(ii) For an individual unit, determine
the tested energy factor in accordance
with 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, and round the
value to the nearest 0.01.
(2) For water heaters tested using
uniform energy factor:
(i) The estimated annual operating
cost is calculated as:
(A) For a gas-fired or oil-fired water
heater, the sum of: The product of the
annual gas or oil energy consumption,
determined according to section 6.3.9 or
6.4.6 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 6.3.8 or
6.4.5 of appendix E of this subpart,
times the representative average unit
cost of electricity in dollars per
kilowatt-hour as provided by the
Secretary. Round the resulting sum to
the nearest dollar per year.
(B) For an electric water heater, the
product of the annual energy
consumption, determined according to
section 6.3.7 or 6.4.4 of appendix E of
this subpart, times the representative
average unit cost of electricity in dollars
per kilowatt-hour as provided by the
Secretary. Round the resulting product
to the nearest dollar per year.
(ii) For an individual unit, determine
the tested uniform energy factor in
accordance with section 6.3.6 or 6.4.3 of
appendix E of this subpart, and round
the value to the nearest 0.01.
*
*
*
*
*
■ 9. Section 430.23 paragraph (e) is
further revised, proposed to be effective
(date one year after publication of test
procedure final rule), to read as follows:
§ 430.23 Test procedures for the
measurement of energy and water
consumption.
*
*
*
*
*
(e) Water Heaters.
(1) The estimated annual operating
cost is calculated as:
(i) For a gas-fired or oil-fired water
heater, the sum of: The product of the
annual gas or oil energy consumption,
determined according to section 6.3.9 or
6.4.6 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 6.3.8 or
6.4.5 of appendix E of this subpart,
times the representative average unit
cost of electricity in dollars per
kilowatt-hour as provided by the
Secretary. Round the resulting sum to
the nearest dollar per year.
(ii) For an electric water heater, the
product of the annual energy
consumption, determined according to
section 6.3.7 or 6.4.4 of appendix E of
this subpart, times the representative
average unit cost of electricity in dollars
per kilowatt-hour as provided by the
Secretary. Round the resulting product
to the nearest dollar per year.
(2) For an individual unit, determine
the tested uniform energy factor in
accordance with section 6.3.6 or 6.4.3 of
appendix E of this subpart, and round
the value to the nearest 0.01.
*
*
*
*
*
■ 10. 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 uniform energy
factor of water heaters shall not be less
than the following:
Product class
Rated storage volume and input rating
(if applicable)
Draw pattern
Gas-fired Storage Water Heater ............
<20 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 .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
0.2471–(0.0002 x Vr).
0.5132–(0.0012 x Vr).
0.5827–(0.0015 x Vr).
0.6507–(0.0019 x Vr).
0.3456–(0.0020 x Vr).
0.5982–(0.0019 x Vr).
0.6483–(0.0017 x Vr).
0.6920–(0.0013 x Vr).
0.6470–(0.0006 x Vr).
0.7689–(0.0005 x Vr).
0.7897–(0.0004 x Vr).
0.8072–(0.0003 x Vr).
0.1755–(0.0006 x Vr).
0.4671–(0.0015 x Vr).
0.5719–(0.0018 x Vr).
0.6916–(0.0022 x Vr).
0.1822–(-0.0001 x Vr).
0.5313–(0.0014 x Vr).
0.6316–(0.0020 x Vr).
0.7334–(0.0028 x Vr).
0.1068–(0.0007 x Vr).
0.4190–(0.0017 x Vr).
0.5255–(0.0021 x Vr).
0.6438–(0.0025 x Vr).
0.7836–(0.0013 x Vr).
0.8939–(0.0008 x Vr).
0.9112–(0.0007 x Vr).
0.9255–(0.0006 x Vr).
0.8808–(0.0008 x Vr).
0.9254–(0.0003 x Vr).
E:\FR\FM\30AUP2.SGM
30AUP2
≥20 gal and ≤55 gal .............................
>55 gal and ≤100 gal ...........................
>100 gal ...............................................
mstockstill on DSK3G9T082PROD with PROPOSALS2
Oil-fired Storage Water Heater ..............
≤50 gal .................................................
>50 gal .................................................
Electric Storage Water Heaters .............
<20 gal .................................................
≥20 gal and ≤55 gal .............................
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59797
Uniform energy factor
59798
Federal Register / Vol. 81, No. 168 / Tuesday, August 30, 2016 / Proposed Rules
Rated storage volume and input rating
(if applicable)
Product class
>55 gal and ≤120 gal ...........................
>120 gal ...............................................
Tabletop Water Heater ...........................
All .........................................................
Instantaneous Gas-fired Water Heater ..
<2 gal and >50,000 Btu/h ....................
≥2 gal or ≤50,000 Btu/h .......................
Instantaneous Oil-fired Water Heater ....
All .........................................................
Instantaneous Electric Water Heater .....
All .........................................................
Grid-Enabled Water Heater ....................
>75 gal .................................................
Draw pattern
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 .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Very Small ............
Low .......................
Medium .................
High .......................
Uniform energy factor
0.9307–(0.0002
0.9349–(0.0001
1.9236–(0.0011
2.0440–(0.0011
2.1171–(0.0011
2.2418–(0.0011
0.6802–(0.0003
0.8620–(0.0006
0.9042–(0.0007
0.9437–(0.0007
0.6323–(0.0058
0.9188–(0.0031
0.9577–(0.0023
0.9884–(0.0016
0.7964–(0.0000
0.8055–(0.0000
0.8070–(0.0000
0.8086–(0.0000
0.3013–(0.0023
0.5421–(0.0024
0.5942–(0.0021
0.6415–(0.0017
0.1430–(0.0015
0.4455–(0.0023
0.5339–(0.0023
0.6245–(0.0021
0.9161–(0.0039
0.9159–(0.0009
0.9160–(0.0005
0.9161–(0.0003
1.0136–(0.0028
0.9984–(0.0014
0.9853–(0.0010
0.9720–(0.0007
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
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).
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
Vr).
*Vr is the rated storage volume in gallons.
*
*
*
*
Authority: 42 U.S.C. 6291–6317. 28 U.S.C.
2461 note.
*
PART 431—ENERGY EFFICIENCY
PROGRAM FOR CERTAIN
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
■
11. The authority citation for part 431
continues to read as follows:
§ 431.110 Energy conservation standards
and their effective dates.
■
12. Section 431.110 is amended by
revising paragraph (d) [proposed at 81
FR 34440. 34536–34537 (May 31, 2016)]
to read as follows:
*
*
*
*
*
(d) Each residential-duty commercial
water heater manufactured prior to (date
3 years after publication in the Federal
Register of the final rule establishing
amended energy conservation standards
for commercial water-heating
equipment) must meet the applicable
energy conservation standard level(s) as
follows:
Product class
Specifications a
Draw pattern
Gas-fired Storage .......................................
>75 kBtu/hr and ≤105 kBtu/hr and ≤120 gal .....
Oil-fired Storage .........................................
>105 kBtu/hr and ≤140 kBtu/hr and ≤120 gal ...
Electric Instantaneous ................................
>12 kW and ≤58.6 kW and ≤2 gal ....................
Very Small ...............
Low ..........................
Medium ....................
High .........................
Very Small ...............
Low ..........................
Medium ....................
High .........................
Very Small ...............
Low ..........................
Medium ....................
High .........................
Uniform energy factor b
0.2670
0.5356
0.5996
0.6592
0.2932
0.5596
0.6194
0.6740
0.80
0.80
0.80
0.80
¥
¥
¥
¥
¥
¥
¥
¥
(0.0009
(0.0012
(0.0011
(0.0009
(0.0015
(0.0018
(0.0016
(0.0013
×
×
×
×
×
×
×
×
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
Vr)
mstockstill on DSK3G9T082PROD with PROPOSALS2
a Additionally, to be classified as a residential-duty commercial water heater, a commercial water heater must meet the following conditions: (1)
If the water heater requires electricity, it must use a single-phase external power supply; and (2) the water heater must not be designed to heat
water to temperatures greater than 180 °F.
b V is the rated storage volume in gallons.
r
*
*
*
*
*
[FR Doc. 2016–20097 Filed 8–29–16; 8:45 am]
BILLING CODE 6450–01–P
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]]>Agencies
[Federal Register Volume 81, Number 168 (Tuesday, August 30, 2016)]
[Proposed Rules]
[Pages 59735-59798]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-20097]
[[Page 59735]]
Vol. 81
Tuesday,
No. 168
August 30, 2016
Part II
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. 81 , No. 168 / Tuesday, August 30, 2016 /
Proposed Rules
[[Page 59736]]
-----------------------------------------------------------------------
DEPARTMENT OF ENERGY
10 CFR Parts 429, 430, and 431
[Docket No. 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: Supplemental notice of proposed rulemaking.
-----------------------------------------------------------------------
SUMMARY: The U.S. Department of Energy (DOE) proposes to establish a
mathematical conversion factor to translate the current energy
conservation standards and the measured values determined under the
energy factor, thermal efficiency, and standby loss test procedures for
consumer water heaters and certain commercial water heaters to those
determined under the more recently adopted uniform energy factor test
procedure. As required by the Energy Policy and Conservation Act of
1975 (EPCA), as amended, DOE initially presented proposals for
establishing a mathematical conversion factor in a notice of proposed
rulemaking (NOPR) published on April 14, 2015 (April 2015 NOPR). Upon
further analysis and review of the public comments received in response
to the April 2015 NOPR, DOE is publishing this supplemental notice of
proposed rulemaking (SNOPR), which: updates the proposed mathematical
conversion factors based on new test data received after the
publication of the April 2015 NOPR; proposes updates to the methodology
for developing the conversions for certain covered water heaters based
on feedback received from interested parties; and proposes a new
approach for denominating the existing energy conservation standards in
terms of the new uniform energy factor (UEF) metric.
DATES: Comments: DOE will accept comments, data, and information
regarding this SNOPR submitted no later than September 29, 2016. See
section V, ``Public Participation,'' for details.
ADDRESSES: All comments submitted must identify the SNOPR for Test
Procedures for the Conversion Factor for Consumer and Certain
Commercial Water Heaters, and provide docket number EERE-2015-BT-TP-
0007 and/or regulatory information number (RIN) 1904-AC91. Comments may
be submitted using any of the following methods:
1. Federal eRulemaking Portal: www.regulations.gov. Follow the
instructions for submitting comments.
2. 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.
3. Postal Mail: Ms. Ashley Armstrong, 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.
4. Hand Delivery/Courier: Ms. Ashley Armstrong, U.S. Department of
Energy, Building Technologies Office, 950 L'Enfant Plaza SW., Room
6094, 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, which includes Federal Register notices, public
meeting attendee lists and transcripts, comments, and other supporting
documents/materials, is available for review at www.regulations.gov.
All documents in the docket are listed in the www.regulations.gov
index. However, not all documents listed in the index may be publicly
available, such as those containing information that is exempt from
public disclosure.
A link to the docket Web page can be found at: https://www.regulations.gov/docket?D=EERE-2015-BT-TP-0007. This Web page
contains a link to the docket for this notice 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 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 Supplemental Notice of Proposed Rulemaking
III. Discussion
A. Purpose
B. Scope
C. Approaches for Developing Conversions
1. Overview of Analytical Methods Approach
2. Overview of Empirical Regression Approach
3. Overview of Hybrid Approach
4. Analytical Methods Approach
a. Maximum GPM
b. First-Hour Rating
c. Uniform Energy Factor
i. Consumer Storage Water Heaters
ii. Consumer Instantaneous Water Heater
iii. Residential-Duty Commercial Storage Water Heaters
iv. Residential-Duty Commercial Electric Instantaneous Water
Heaters
5. Empirical Regression Approach
D. Testing Conducted for the Mathematical Conversion
1. Repeatability
E. Testing Results and Analysis of Test Data
1. Impact of Certain Water Heater Attributes on Efficiency
Ratings
2. Conversion Factor Derivation
a. Consumer Storage Water Heaters
i. Test Results
ii. Conversion Factor Results
b. Consumer Instantaneous Water Heaters
i. Test Results
ii. Conversion Factor Results
c. Residential-Duty Commercial Storage Water Heaters
i. Test Results
ii. Conversion Factor Results
d. Residential-Duty Commercial Instantaneous Water Heaters
e. Grid-Enabled Storage Water Heaters
3. Energy Conservation Standard Derivation
a. Storage Volume Used for Calculations
F. Compliance and Grandfathering
G. Certification
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
[[Page 59737]]
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
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 Energy Efficiency Improvement Act of 2015
(EEIA 2015), Public Law 114-11 (April 30, 2015).
\3\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
Under EPCA, DOE's energy conservation program generally consists of
four parts: (1) Testing; (2) labeling; (3) 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 certain
equipment comply with any relevant standards promulgated under EPCA.
(42 U.S.C. 6295(s); 42 U.S.C. 6314)
EPCA 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); 6313(a)(6)(B)(iii)(I)) 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); 6313(a)(6)(B)(iii)(II))
EPCA prescribed the energy conservation standards for consumer
water heaters, shown in Table I.1 (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.
Table I.1--EPCA Initial Energy Conservation Standards for Consumer Water
Heaters
------------------------------------------------------------------------
Product class Energy factor
------------------------------------------------------------------------
Gas Water Heater..................... 0.62 - (0.0019 x Rated Storage
Volume in gallons).
Oil Water Heater..................... 0.59 - (0.0019 x Rated Storage
Volume in gallons).
Electric Water Heater................ 0.95 - (0.00132 x Rated Storage
Volume in gallons).
------------------------------------------------------------------------
On October 17, 1990, DOE published a final rule which updated the
test procedure from a no-draw test to a six-draw, 24-hour simulated-use
test. 55 FR 42162. The effect of this change in test procedure was
investigated on a sample of representative units and based on the
results of testing on those units, DOE updated the energy conservation
standard for electric water heaters to reflect the new test procedure.
To account for the change in test procedure for electric water heaters,
DOE amended the standard to 0.93-(0.00132 x Rated Storage Volume). Id.
at 42177. DOE notes that these statutory energy conservation standards
apply to both storage and instantaneous consumer water heaters
regardless of volume capacity.
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 specified classes of consumer water heaters,
and maintained the existing energy conservation standards for tabletop
and electric instantaneous water heaters. 75 FR 20112. The standards
adopted by the April 2010 final rule are shown below in Table I.2.
These standards apply to all water heater product classes listed in
Table I.2 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.2--DOE Energy Conservation Standards for Consumer Water Heaters
------------------------------------------------------------------------
Rated storage
Product class volume *** Energy factor **
------------------------------------------------------------------------
Gas-fired Storage............... >=20 gal and <=55 0.675 - (0.0015 x
gal. Vs).
>55 gal and <=100 0.8012 - (0.00078
gal. x Vs).
Oil-fired Storage............... <=50 gal.......... 0.68 - (0.0019 x
Vs).
Electric Storage................ >=20 gal and <=55 0.96 - (0.0003 x
gal. Vs).
[[Page 59738]]
>55 gal and <=120 2.057 - (0.00113 x
gal. Vs).
Tabletop*....................... >=20 gal and <=120 0.93 - (0.00132 x
gal. 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 water heater 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).
Water heaters that use gas, oil, electricity, or a combination of
these fuels, that are not within the rated storage volume sizes stated
in Table I.2 (e.g., gas-fired storage less than 20 gallons or greater
than 100 gallons), are subject to the applicable energy conservation
standard established in EPCA.
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 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)) The
statute was subsequently amended to require DOE to review its standards
for commercial water heaters (and other ``ASHRAE equipment'') every six
years. (42 U.S.C. 6313(a)(6)(C)) On January 12, 2001, DOE published a
final rule for commercial water heating equipment that amended energy
conservation standards by adopting the levels in ASHRAE Standard 90.1-
1999 for all types of commercial water heating equipment, except for
electric storage water heaters. 66 FR 3336. For electric storage water
heaters, the standard in ASHRAE Standard 90.1-1999 was less stringent
than the standard prescribed in EPCA and, consequently, would have
increased energy consumption, so DOE maintained the standards for
electric storage water heaters at the statutorily prescribed level. DOE
published the most recent final rule for commercial water heating
equipment on July 17, 2015, in which DOE adopted the thermal efficiency
level for oil-fired storage water heaters that was included in ASHRAE
90.1-2013. 80 FR 42614. The current standards for commercial water
heating equipment are presented in Table I.3.
Table I.3--Energy Conservation Standards for Commercial Water Heating Equipment
----------------------------------------------------------------------------------------------------------------
Energy conservation standards*
--------------------------------------------------
Minimum thermal
Equipment category Size efficiency (equipment Maximum standby loss
manufactured on and (equipment manufactured
after October 9, 2015) on and after October 29,
** [dagger] (%) 2003)** [dagger][dagger]
----------------------------------------------------------------------------------------------------------------
Electric storage water heaters...... All.................... N/A 0.30 + 27/Vm(%/h).
Gas-fired storage water heaters..... <=155,000 Btu/h........ 80 Q/800 + 110(Vr)1/2 (Btu/
h).
>155,000 Btu/h......... 80 Q/800 + 110(Vr)1/2 (Btu/
h).
Oil-fired storage water heaters..... <=155,000 Btu/h........ 80[dagger] Q/800 + 110(Vr)1/2 (Btu/
h).
>155,000 Btu/h......... 80[dagger] Q/800 + 110(Vr)1/2 (Btu/
h).
Electric instantaneous water <10 gal................ 80 N/A.
heaters[dagger][dagger][dagger].
>=10 gal............... 77 2.30 + 67/Vm (%/h).
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/
h).
Oil-fired instantaneous water heater <10 gal................ 80 N/A.
and hot water supply boilers.
>=10 gal............... 78 Q/800 + 110(Vr)1/2 (Btu/
h)
----------------------------------------------------------------------------------------------------------------
Equipment Category 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/h.
** For hot water supply boilers with a capacity of less than 10 gallons: (1) The standards are mandatory for
units manufactured on and after October 21, 2005 and (2) units manufactured on or after October 23, 2003, but
prior to October 21, 2005, must meet either the standards listed in this table or the applicable standards in
Subpart E of this Part for a ``commercial packaged boiler.''
[dagger] For oil-fired storage water heaters: (1) The standards are mandatory for equipment manufactured on and
after October 9, 2015, and (2) equipment manufactured prior to that date must meet a minimum thermal
efficiency level of 78 percent.
[[Page 59739]]
[dagger][dagger] 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-fired or oil-fired storage water heaters, they
have a fire damper or fan-assisted combustion.
[dagger][dagger][dagger] Energy conservation standards for electric instantaneous water heaters are included in
EPCA. (42 U.S.C. 6313(a)(5)(D)-(E)) The compliance date for these energy conservation standards is January 1,
1994. In a NOPR for energy conservation standards for commercial water heating equipment published on May 31,
2016, DOE proposed to codify these standards for electric instantaneous water heaters in its regulations at 10
CFR 431.110. 81 FR 34440.
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 consumer water heaters and certain commercial water heating
equipment \4\ within one year of the enactment of AEMTCA. (42 U.S.C.
6295(e)(5)(B)) The final rule must replace the energy factor (EF),
thermal efficiency (TE), and standby loss (SL) metrics with a uniform
efficiency descriptor. (42 U.S.C. 6295(e)(5)(C)) On July 11, 2014, DOE
published a final rule that fulfilled these requirements. 79 FR 40542
(July 2014 final rule). 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 for converting the measurement of efficiency from the test
procedures and metrics in effect at that time to the uniform efficiency
descriptor. (42 U.S.C. 6295(e)(5)(E)(i)-(ii))
---------------------------------------------------------------------------
\4\ The uniform efficiency descriptor and accompanying test
procedure apply to commercial water heating equipment with
residential applications defined in the test procedure final rule
published July 11, 2014, as a ``residential-duty commercial water
heater.'' See 79 FR 40542, 40586.
---------------------------------------------------------------------------
EPCA provides that any covered water heater (i.e., under DOE's
rulemaking, all consumer water heaters and residential-duty commercial
water heaters) manufactured prior to the effective date of the UEF test
procedure final rule (i.e., July 13, 2015) that complied with the
efficiency standards and labeling requirements applicable at the time
of manufacture will be considered to comply with the UEF test procedure
final rule and with any revised labeling requirements established by
the Federal Trade Commission (FTC) to carry out the UEF test procedure
final rule. (42 U.S.C. 6295(e)(5)(K)) DOE's interpretation and
application of this provision are discussed in detail in Section III.F.
As noted previously, in the July 2014 final rule, DOE amended its
test procedure for consumer and certain commercial water heaters. 79 FR
40542. 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 EF, TE, and SL metrics. The
amended test procedure includes 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) 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 were not addressed by
the previous test method); and (2) commercial water heaters that have
residential applications. The major modifications to the EF 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 all storage volumes, specifically by
including 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 definition for ``residential-duty
commercial water heater'' and re-categorized certain commercial water
heaters into this class.
This rulemaking is intended to satisfy the requirements of AEMTCA
to develop a mathematical conversion factor for converting the EF, TE,
and SL metrics to the UEF metric. (42 U.S.C. 6295(e)(5)(E)) As an
initial step in conducting this rulemaking, DOE published a notice of
proposed rulemaking on April 14, 2015, which included proposed
mathematical conversion factors and proposed updates to the energy
conservation standards. 80 FR 20116.
The Energy Efficiency Improvement Act of 2015 (EEIA 2015) (Pub. L.
114-11) was enacted on April 30, 2015. Among other things, EEIA 2015
added a definition of ``grid-enabled water heater'' to EPCA's energy
conservation standards for consumer water heaters. (42 U.S.C.
6295(e)(6)(A)(ii)) These products are intended for use as part of an
electric thermal storage or demand response program. One of the
criteria in EPCA that defines a ``grid-enabled water heater'' is the
requirement that it meet a certain energy factor (specified by a
formula set forth in the statute), or an equivalent alternative
standard that DOE may prescribe. Id. On August 11, 2015, DOE published
a final rule in the Federal Register to implement the changes to EPCA
by placing the energy conservation standards and related definitions in
the Code of Federal Regulations (CFR). 80 FR 48004. As the energy
conservation standard for grid-enabled water heaters is in terms of
energy factor, DOE is addressing these products in this notice to
propose a mathematical conversion and updated energy conservation
standard in terms of UEF.
II. Summary of the Supplemental Notice of Proposed Rulemaking
In this SNOPR, DOE proposes to establish a mathematical conversion
factor between the values determined using the EF, TE, and SL test
procedures (including the first-hour rating or maximum gallons per
minute (GPM) rating, as applicable), and the values that would be
determined using the uniform efficiency descriptor test procedure
established in the July 2014 final rule (i.e., UEF and first-hour
rating or maximum GPM rating). After further analysis and review of the
public comments received in response to the April 2015 NOPR, DOE is
publishing this SNOPR to: (1) Update the proposed mathematical
conversion factors based on new test data received after the
publication of the April 2015 NOPR; (2) propose to update the
approaches considered for developing the conversion factors for
standard and low NOX non-condensing gas fired storage water
heaters, condensing storage water heaters, tabletop water heaters, heat
pump water heaters and residential-duty water heaters; and (3) propose
a new approach for denominating the existing energy conservation
standards in terms of the new uniform energy factor metric.
Other than the specific amendments newly proposed in this SNOPR,
DOE
[[Page 59740]]
continues to propose the amendments originally included in the April
2015 NOPR. 80 FR 20116 (April 14, 2015). For the reader's convenience,
DOE has reproduced in this SNOPR the entire body of latest proposed
regulatory text from the April 2015 NOPR, amended as appropriate
according to these proposals. DOE's supporting analysis and discussion
for the portions of the proposed regulatory text not affected by this
SNOPR may be found in the April 2015 NOPR.
The mathematical conversion factor required by AEMTCA is a bridge
between the values \5\ obtained through testing under the EF, TE, and
SL test procedures and those obtained under the uniform efficiency
descriptor test procedure published in the July 2014 final rule. DOE
conducted a series of tests on the classes of water heaters included
within the scope of this rulemaking (see section III.B for details on
the scope) and relied upon that test data and test data submitted by
interested parties to develop the proposals in this SNOPR. DOE used the
test data, along with the approaches described in section III.C, to
calculate the conversion factors proposed in this SNOPR. To develop
conversion factors for this SNOPR, DOE generally used the same
methodology as proposed in the April 2015 NOPR (with several exceptions
discussed in more detail in section III.E.2), and presents in this
document the updated conversion factors based on the inclusion of
additional test data. Subsequently, DOE used the conversion factors to
derive minimum energy conservation standards in terms of UEF, as shown
in Table II.1 and Table II.2. For this SNOPR, DOE adopted a new
approach to denominating the energy conservation standards in terms of
the UEF metric, which is explained in detail in section III.E.3. The
proposed standards denominated in UEF are neither more nor less
stringent than the EF-denominated standards for consumer water heaters
(as amended by the April 2010 final rule) and for commercial water-
heating equipment based on the thermal efficiency and standby loss
metrics.
---------------------------------------------------------------------------
\5\ The term ``represented values'' includes all efficiency or
performance-related information included in product ratings,
nameplates, public representations (literature, product sheets,
etc.).
Table II.1--Proposed Consumer Water Heater Energy Conservation Standards
----------------------------------------------------------------------------------------------------------------
Rated storage volume and
Product class input rating (if Draw pattern Uniform energy factor
applicable)
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage Water Heater..... <20 gal.................... Very Small............ 0.2471-(0.0002 x Vr).
Low................... 0.5132-(0.0012 x Vr).
Medium................ 0.5827-(0.0015 x Vr).
High.................. 0.6507-(0.0019 x Vr).
>=20 gal and <=55 gal...... Very Small............ 0.3456-(0.0020 x Vr).
Low................... 0.5982-(0.0019 x Vr).
Medium................ 0.6483-(0.0017 x Vr).
High.................. 0.6920-(0.0013 x Vr).
>55 gal and <=100 gal...... Very Small............ 0.6470-(0.0006 x Vr).
Low................... 0.7689-(0.0005 x Vr).
Medium................ 0.7897-(0.0004 x Vr).
High.................. 0.8072-(0.0003 x Vr).
>100 gal................... Very Small............ 0.1755-(0.0006 x Vr).
Low................... 0.4671-(0.0015 x Vr).
Medium................ 0.5719-(0.0018 x Vr).
High.................. 0.6916-(0.0022 x Vr).
Oil-fired Storage Water Heater..... <=50 gal................... Very Small............ 0.1822-(-0.0001 x Vr).
Low................... 0.5313-(0.0014 x Vr).
Medium................ 0.6316-(0.0020 x Vr).
High.................. 0.7334-(0.0028 x Vr).
>50 gal.................... Very Small............ 0.1068-(0.0007 x Vr).
Low................... 0.4190-(0.0017 x Vr).
Medium................ 0.5255-(0.0021 x Vr).
High.................. 0.6438-(0.0025 x Vr).
Electric Storage Water Heaters..... <20 gal.................... Very Small............ 0.7836-(0.0013 x Vr).
Low................... 0.8939-(0.0008 x Vr).
Medium................ 0.9112-(0.0007 x Vr).
High.................. 0.9255-(0.0006 x Vr).
>=20 gal and <=55 gal...... Very Small............ 0.8808-(0.0008 x Vr).
Low................... 0.9254-(0.0003 x Vr).
Medium................ 0.9307-(0.0002 x Vr).
High.................. 0.9349-(0.0001 x Vr).
>55 gal and <=120 gal...... Very Small............ 1.9236-(0.0011 x Vr).
Low................... 2.0440-(0.0011 x Vr).
Medium................ 2.1171-(0.0011 x Vr).
High.................. 2.2418-(0.0011 x Vr).
>120 gal................... Very Small............ 0.6802-(0.0003 x Vr).
Low................... 0.8620-(0.0006 x Vr).
Medium................ 0.9042-(0.0007 x Vr).
High.................. 0.9437-(0.0007 x Vr).
Tabletop Water Heater.............. All........................ Very Small............ 0.6323-(0.0058 x Vr).
Low................... 0.9188-(0.0031 x Vr).
Medium................ 0.9577-(0.0023 x Vr).
High.................. 0.9884-(0.0016 x Vr).
[[Page 59741]]
Instantaneous Gas-fired Water <2 gal and >50,000 Btu/h... Very Small............ 0.7964-(0.0000 x Vr).
Heater. Low................... 0.8055-(0.0000 x Vr).
Medium................ 0.8070-(0.0000 x Vr).
High.................. 0.8086-(0.0000 x Vr).
>=2 gal or <=50,000 Btu/h.. Very Small............ 0.3013-(0.0023 x Vr).
Low................... 0.5421-(0.0024 x Vr).
Medium................ 0.5942-(0.0021 x Vr).
High.................. 0.6415-(0.0017 x Vr).
Instantaneous Oil-fired Water All........................ Very Small............ 0.1430-(0.0015 x Vr).
Heater. Low................... 0.4455-(0.0023 x Vr).
Medium................ 0.5339-(0.0023 x Vr).
High.................. 0.6245-(0.0021 x Vr).
Instantaneous Electric Water Heater All........................ Very Small............ 0.9161-(0.0039 x Vr).
Low................... 0.9159-(0.0009 x Vr).
Medium................ 0.9160-(0.0005 x Vr).
High.................. 0.9161-(0.0003 x Vr).
Grid-Enabled Water Heater.......... >75 gal.................... Very Small............ 1.0136-(0.0028 x Vr).
Low................... 0.9984-(0.0014 x Vr).
Medium................ 0.9853-(0.0010 x Vr).
High.................. 0.9720-(0.0007 x Vr).
----------------------------------------------------------------------------------------------------------------
*Vr is the rated storage volume which is 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.................. 0.2670--(0.0009 x Vr).
Low......................... 0.5356--(0.0012 x Vr).
Medium...................... 0.5996--(0.0011 x Vr).
High........................ 0.6592--(0.0009 x Vr).
Oil-fired Storage.................................... Very Small.................. 0.2932--(0.0015 x Vr).
Low......................... 0.5596--(0.0018 x Vr).
Medium...................... 0.6194--(0.0016 x Vr).
High........................ 0.6740--(0.0013 x Vr).
Electric Instantaneous............................... Very Small.................. 0.80.
Low......................... 0.80.
Medium...................... 0.80.
High........................ 0.80.
----------------------------------------------------------------------------------------------------------------
* Vr is the rated storage volume, which is the water storage capacity of a water heater (in gallons), as
specified by the manufacturer.
The conversion factor formulas may be used for one year beginning
on the date of publication of the conversion factor final rule in the
Federal Register. After that time, all representations regarding energy
efficiency or energy use must be based on testing (either directly or
through the application of an AEDM, where permitted). In addition, EPCA
requires that a 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 FTC to carry out the July 2014 final rule if that water heater
basic model was manufactured prior to July 13, 2015, and complied with
the applicable efficiency standards and labeling requirements in effect
prior to July 13, 2015. (See 42 U.S.C. 6295(e)(5)(K)) Sections III.F
and III.G explain that DOE intends to address various issues related to
the transition from the metrics in effect prior to July 13, 2015,
through the use of enforcement policies.
III. Discussion
A. Purpose
As discussed in section I, DOE has undertaken this rulemaking to
establish a mathematical conversion factor as a result of requirements
added to EPCA by AEMTCA. (42 U.S.C. 6295(e)(5)) EPCA requires DOE to
establish a uniform efficiency descriptor for consumer water heaters
and commercial water heaters, and to establish a mathematical
conversion factor to translate from the EF, TE, and SL descriptors to
the uniform efficiency descriptor established by DOE. Id. In the July
2014 test procedure final rule, DOE established UEF as the uniform
efficiency descriptor, and adopted a test method for measuring UEF for
consumer and certain commercial water heaters. 79 FR 40542 (July 11,
2014). The current rulemaking addresses the mathematical conversion
factor required by EPCA (see 42 U.S.C. 6295(e)(5)(E)) and the
requirement that the efficiency standard be denominated according to
the uniform efficiency descriptor (i.e., UEF) (see 42 U.S.C.
6295(e)(5)(D)(i)).
Based on review of the test results used to develop the
mathematical conversion factors, DOE has found that different water
heaters are impacted in different ways by the new test method and
metric, depending on the specific design and characteristics of the
water heater. Water heaters have numerous attributes that impact energy
efficiency and performance, and the changes to the test method and
metrics impact each water heater model differently, often in ways that
are difficult to predict. For example, two electric water heaters with
the same rated storage volume, input rating, first-hour rating, and
energy factor rating (all represented values published under the EF
test method as indicators of water heater performance)
[[Page 59742]]
have been shown by testing to have different measured first-hour
ratings and uniform energy factors when tested under the new test
procedure.
Given the number of models currently available in the market (756
unique basic models as of September 2015), it would not be practical to
analyze each model individually to determine the change in represented
values under the new test procedure. Rather, DOE has analyzed a subset
of models that are representative of the market as a whole (see section
III.D for further discussion of the models tested for this rule). This
approach is consistent with the statutory mandate, which instructs DOE
to develop ``a mathematical conversion factor.'' (42 U.S.C.
6295(e)(5)(E)) DOE recognizes that the phrase ``mathematical conversion
factor'' does not require DOE to generate a single number applicable to
all water heaters. For one thing, DOE believes that, despite the use of
the word ``factor,'' in the singular, the statute permits the use of a
conversion equation involving several numbers and mathematical
operations besides multiplication. Still, the phrasing suggests that
DOE should develop a formula that is broadly applicable, rather than
generate a table of equivalencies stating the exact UEF equivalent for
every individual product on the market.
Because each water heater is impacted differently, it would be
impossible to develop a single equation, or reasonable set of
equations, that could be used to model the energy performance of every
water heater exactly under the new test method. Therefore, the purpose
of this mathematical conversion factor is to develop an equation that
will be able to reasonably predict a water heater's energy efficiency
under the UEF test method based on values measured under the EF, TE, or
SL test methods for that model.
Any mathematical conversion will have some amount of residual
difference between predicted and measured values that is inherent when
applying a mathematical equation (or multiple equations for different
types of water heaters) to predict the energy efficiency performance or
delivery capacity of a large set of models. In this rule, DOE has
sought to minimize the amount of difference between predicted and
actual performance in several ways. DOE incorporated as much test data
as was practical and available, and which represented models currently
on the market (see section III.D). DOE considered several attributes
that could have a large impact on the test results under both the new
and old metrics, and included those as appropriate when developing the
mathematical conversion, which led to a set of equations for water
heaters with certain different characteristics (e.g., different fuel
types, different nitrogen oxide (NOX) emissions levels). DOE
also explored several options for identifying the most accurate
methodologies for developing the mathematical conversion equations (see
section III.C). In addition, DOE sought feedback from interested
parties and incorporated suggestions for improving the mathematical
conversions when the suggested changes in approach resulted in
conversion equations that were better predictors of actual measured
performance.
As noted previously, this rulemaking also addresses the requirement
that the efficiency standard be denominated in terms of UEF, and in
this notice DOE proposes energy conservation standard levels using the
UEF metric. (42 U.S.C. 6295(e)(5)(D)(i)) As discussed in section I, DOE
may not adopt a standard that reduces the stringency of the existing
standards, due to the ``anti-backsliding'' clause. (42 U.S.C.
6295(o)(1); 6313(a)(6)(B)(iii)(I)) Further, EPCA requires that the
mathematical conversion factor not affect the minimum efficiency
requirements. (42 U.S.C 6295(e)(5)(E)(iii)).
The methodology proposed in section III.E.3 for translating the
standards is intended to ensure equivalent stringency between the
existing standards (using EF, TE, and SL metrics) and the proposed
updated standards (using UEF). Due to differences in water heater
performance under the different test methods discussed in the preceding
paragraphs, some models will perform better, and others worse, under
the new test method than they did under the previous test method. Even
though the stringency with respect to a specific model may vary based
on the characteristics and performance of that model, the proposed
approach for translating the standard is designed to maintain the same
stringency for each product class as a whole. Because DOE's goal is to
maintain the same stringency of the standards under the EF, TE, and SL
metrics (i.e., the standards in terms of the new UEF metric are neither
more nor less stringent), and because individual models are impacted
differentially by the change in test method and metric, some models
that were previously minimally compliant will perform better than the
translated UEF minimum, and others will perform worse. The possibility
of such outcomes would not, by itself, mean that the conversion
methodology was improper. As noted above, the possibility of some
deviation for individual products is inherent in the use of a broad-
based conversion equation. However, because the statute nonetheless
mandates that the Department develop a ``mathematical conversion
factor,'' DOE understands the statute to permit the consequences that
naturally follow from that approach.
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
initially outlined the scope of this rulemaking in the April 2015 NOPR.
80 FR 20116, 20122-24 (April 14, 2015). In summary, this rulemaking
includes all covered consumer water heaters, as well as commercial
water heaters meeting the definition of ``residential-duty commercial
water heater.'' In the NOPR, DOE stated that it was not including water
heaters that were not previously subject to the test procedures or
standards for energy factor established in the Code of Federal
Regulations in the scope of the conversion factor, as they are not
required to be tested and rated for efficiency under the DOE test
method. Id. Table III.1 lists the consumer water heaters that, for this
reason, DOE did not propose a mathematical conversion factor in the
NOPR.
Table III.1--Consumer Water Heaters Not Covered in the NOPR 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.
Oil-fired Storage...................... Rated Storage Volume >50 gal.
Electric Storage....................... Rated Storage Volume >=2 gal
and <20 gal or >120 gallons.
Tabletop............................... Rated Storage Volume >=2 gal
and <20 gal or >120 gallons.
Gas-fired Instantaneous................ Rated Input <=50,000 Btu/h;
Rated Storage Volume >=2 gal.
[[Page 59743]]
Electric Instantaneous................. Rated Storage Volume >=2 gal.
Oil-fired Instantaneous................ All.
------------------------------------------------------------------------
DOE has further considered the applicability of standards to the
products listed in Table III.1 and proposes to clarify that the initial
energy conservation standards in EPCA, as listed in Table I.1, are
applicable to gas-fired, electric, and tabletop water heaters below 20
gallons storage volume; gas-fired water heaters above 100 gallons
storage volume; oil-fired water heaters above 50 gallons storage
volume; electric and tabletop water heaters above 120 gallons storage
volume; gas-fired instantaneous water heaters with an input at or below
50,000 Btu/h or at or above 2 gallons storage volume; electric
instantaneous water heaters at or above 2 gallons; and oil-fired
instantaneous water heaters. These products were not considered in
DOE's rulemakings that culminated in the April 16, 2010 and January 17,
2001 final rules (75 FR 20112 and 66 FR 4474, respectively), and
accordingly, the standards adopted in those final rules are not
applicable to these products.
DOE notes that EPCA's definitions for consumer water heaters do not
place any limitation on the storage volume or specify a minimum fuel
input rate for gas-fired instantaneous water heaters. Thus, DOE has
tentatively concluded that the initial standards for water heaters
included in EPCA were intended to cover all water heaters meeting the
definition of a ``water heater'' at 42 U.S.C. 6291(27) and would apply
regardless of the storage volume, and without a lower limit on the fuel
input rating for gas-fired instantaneous water heaters.
In this SNOPR, DOE used the applicable conversion equations to
convert the EPCA-established standards applicable to the products in
Table III.1 from EF to UEF. For electric water heaters, as discussed in
section I, in the October 17, 1990 test procedure final rule, DOE
determined that the standard set by EPCA required adjustment under 42
U.S.C. 6293(e) due to the effect of the change in test procedure. 55 FR
42162, 42164. DOE believes the impact on measured energy characterized
in the October 1990 test procedure final rule resulting from the change
in the test procedure is valid for all consumer electric water heaters
and not just those limited to the gallon sizes specified in the October
1990 test procedure final rule. Accordingly, DOE has used the standard
level adopted in the 1990 test procedure final rule for establishing
converted UEF standards for electric water heaters with storage volumes
below 20 gallons and above 120 gallons.
DOE has found that oil-fired instantaneous water heaters exist on
the market and are available for sale within the United States. Oil-
fired instantaneous water heaters were not defined under the EF test
procedure, nor were these products defined by DOE at 10 CFR 430.2 prior
to the effective date of the July 2014 test procedure final rule that
established the UEF metric. However, oil-fired instantaneous water
heaters are defined by EPCA at 42 U.S.C. 6291(27)(B), were added to the
definitions at 10 CFR 430.2 in the July 2014 test procedure final rule,
and are covered by the UEF test procedure. Because oil-fired
instantaneous water heaters were not previously tested to the EF test
procedure, a conversion factor is not necessary (as manufacturers would
not have EF ratings to convert). Rather, manufacturers of oil-fired
instantaneous water heaters who wish to make representations of
efficiency should test to the UEF metric. However, DOE must still
convert the energy conservation standard established by EPCA from EF to
UEF. The steps taken for this conversion are explained in section
III.E.3.
As noted in section I, EPCA was recently amended to define and set
efficiency requirements for grid-enabled water heaters in terms of EF,
so DOE has included the development of a conversion factor and updated
standard for these products in this SNOPR. DOE has tentatively
determined that these products do not meet the criteria for exclusion
from the UEF metric.
Only commercial water heaters meeting the definition of
``residential-duty commercial water heater'' are subject to the uniform
efficiency descriptor test method, while all other commercial water
heaters are not. As a result, this conversion only addresses commercial
water heaters that meet the definition of ``residential-duty commercial
water heater,'' which includes commercial water heaters that:
(1) For models requiring electricity, uses single-phase power;
(2) Are not designed to provide outlet hot water at temperatures
greater than 180 [deg]F; and
(3) Are 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 Consumer Applications (i.e., Non-Residential-Duty)
------------------------------------------------------------------------
Indicator of non-consumer
Water heater type application
------------------------------------------------------------------------
Gas-fired Storage...................... Rated input >105 kBtu/h; Rated
storage volume >120 gal.
Oil-fired Storage...................... Rated input >140 kBtu/h; Rated
storage volume >120 gal.
Electric Storage....................... Rated input >12 kW; Rated
storage volume >120 gal.
Gas-fired Instantaneous................ Rated input >200 kBtu/h; Rated
storage volume >2 gal.
Electric Instantaneous................. Rated input >58.6 kW; Rated
storage volume >2 gal.
Oil-fired Instantaneous................ Rated input >210 kBtu/h; Rated
storage volume >2 gal.
------------------------------------------------------------------------
Additionally, DOE notes that for several types of water heaters,
definitional criteria preclude their classification as residential-duty
commercial water heaters. For example, an electric storage water heater
with a rated input of greater than 12 kW would not be a residential-
duty commercial water heater, as it is excluded under the
[[Page 59744]]
definition of ``residential-duty commercial water heater'' based on its
rated input; conversely, an input rating at or below 12 kW would place
an electric storage water heater in the consumer water heater category
under EPCA. (See 42 U.S.C. 6291(27)(A)). Therefore, there is no input
rating at which an electric storage water heater would be classified as
a residential-duty commercial water heater. Similarly, EPCA defines
gas-fired instantaneous water heaters with an input of 200,000 Btu per
hour or less, oil-fired instantaneous water heaters with an input of
210,000 Btu per hour or less, and heat pump type water heaters with a
rated input of 12 kW or less, or a rated current of 24 amps or less at
a rated voltage of not greater than 250 volts, as consumer water
heaters. (42 U.S.C. 6291(27)(B)). The residential-duty commercial water
heater criteria in Table III.2 exclude models with input rates above
the input limits from being residential-duty commercial water heaters.
Any water heaters above the applicable limits would be considered non-
residential-duty commercial water heaters, and any water heaters at or
below the applicable limits would be consumer water heaters. Therefore,
in a NOPR for test procedures for certain commercial water heating
equipment published on May 9, 2016 (``May 2016 CWH TP NOPR''), DOE is
proposing to expressly exclude these four classes--electric storage
water heaters, heat pump water heaters, gas-fired instantaneous water
heaters, and oil-fired instantaneous water heaters--from the definition
for ``residential-duty commercial water heater'' codified at 10 CFR
431.102. 81 FR 28588, 28607, 28637. Consequently, a mathematical
conversion and a standard in terms of UEF are only necessary for the
types of water heaters that can be defined as residential-duty
commercial water heaters: gas-fired storage water heaters, oil-fired
storage water heaters, and electric instantaneous water heaters.
In response to the April 2015 NOPR proposals, Air-Conditioning,
Heating, and Refrigeration Institute (AHRI) commented that residential-
duty commercial electric storage water heaters should have a conversion
because electric water heaters that were designed with input rates less
than or equal to 12 kW and deliver water at temperatures of 180 [deg]F
were previously (i.e., before changes to the DOE definition for
``electric storage water heater'' were adopted in the July 2014 test
procedure final rule) not considered to be consumer products. (AHRI,
No. 13 at p. 6) As discussed in the preceding paragraph, there are no
electric storage water heaters that would be classified as residential-
duty commercial water heaters. EPCA includes as consumer electric
storage water heaters those having an input rating less than or equal
to 12 kW and does not distinguish between the consumer and commercial
classifications by delivery temperature. (42 U.S.C. 6291(27)(A))
Therefore, electric storage water heaters with input rates at or below
12 kW are covered consumer products (rather than commercial equipment)
regardless of the delivered water temperature. Thus, the product that
AHRI discusses--electric storage water heaters rated at or below 12 kW
but designed to deliver water at temperatures above 180 [deg]F--would
be classified as a consumer product under EPCA and would not be
eligible for classification as a residential-duty commercial water
heater under DOE's definitions at 10 CFR 431.102. DOE is, therefore,
not proposing a conversion factor for residential-duty commercial
electric storage water heaters, as there can be no such equipment. As
proposed in this SNOPR, a product such as that described by AHRI would
rely on the conversion that has been proposed for electric storage
water heaters generally. Further, although electric storage water
heaters that are designed with input ratings less than or equal to 12
kW and to deliver water at temperatures of 180 [deg]F were not included
in the consumer water heater energy factor test procedure,\6\ they are
consumer products. As consumer products, such water heaters are not
required to be tested under the metric for commercial electric storage
water heaters (i.e., standby loss). Rather, since such products are
classified as consumer products under the statute, DOE proposes to
clarify that they should be tested and rated under the UEF test method.
In the event that the UEF test method does not apply, manufacturers
should submit a petition for waiver DOE (see 10 CFR 430.27) that would
allow them to test and rate their products to the appropriate consumer
water heater efficiency metrics. DOE is proposing in a separate
rulemaking to clarify the definitions for specific kinds of consumer
water heaters by removing the specifications related to the water
delivery temperature. 81 FR 28636. Finally, DOE 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.
---------------------------------------------------------------------------
\6\ Prior to being updated by the July 11, 2014 final rule (79
FR 40542, 40567), the Uniform Test Method for Measuring the Energy
Consumption of Water Heaters at appendix E to subpart B of 10 CFR
430 included a definition for ``Electric Storage-type Water Heater''
that included only, in relevant part, models designed to heat and
store water at a thermostatically-controlled temperature of less
than 180 [deg]F.
---------------------------------------------------------------------------
AHRI also commented that residential-duty electric instantaneous
water heaters exist as defined in the UEF test procedure and,
therefore, need a conversion. (AHRI, No. 13 at p. 6) DOE agrees that
residential-duty commercial electric instantaneous water heaters exist
on the market and that they are currently subject to the commercial
water heating equipment test procedures. 10 CFR 431.106. Commercial
electric instantaneous water heaters are also subject to the energy
conservation standards for commercial instantaneous water heaters
established in EPCA. (42 U.S.C. 6313(a)(5)(D)-(E)).\7\ Specifically,
for commercial instantaneous water heaters with a storage volume of
less than 10 gallons, the minimum thermal efficiency is 80 percent. For
commercial instantaneous water heaters with a storage volume of 10
gallons or greater, the minimum thermal efficiency is 77 percent, and
the maximum standby loss is 2.30 + (67/Measured Storage Volume [in
gallons]) percent per hour. Because residential-duty electric
instantaneous commercial water heaters are required to have a storage
volume of 2 gallons or less, the former standard level would apply to
this equipment. 10 CFR 431.102. Therefore, DOE has tentatively decided
to provide a mathematical conversion factor for residential-duty
commercial electric instantaneous water heaters. DOE also proposes
energy conservation standards for residential-duty commercial electric
instantaneous water heaters denominated in the UEF metric. See section
III.E.2.d for further discussion of the mathematical conversion for
this equipment.
---------------------------------------------------------------------------
\7\ In a NOPR for energy conservation standards for commercial
water heating equipment published on May 31, 2016, DOE proposed to
codify the energy conservation standards in EPCA for commercial
electric instantaneous water heaters at 10 CFR 431.110. 81 FR 34440,
34535-36.
---------------------------------------------------------------------------
C. Approaches for Developing Conversions
This section provides the approaches that DOE is considering in
developing equations to convert from prior metrics to the new metrics,
including the benefits and drawbacks of each approach and details on
how the equations were derived.
To develop the conversions between the prior metrics (first-hour
rating,
[[Page 59745]]
maximum GPM, energy factor, thermal efficiency, standby loss) and the
new metrics (first-hour rating, maximum GPM, uniform energy factor),
DOE has broadly considered two different approaches. The first, termed
``analytical methods,'' uses equations based on the fundamental physics
of water heater operation to predict how changes in test parameters
lead to changes in the performance metrics. The second approach, termed
``empirical regression,'' is a purely data-driven approach that uses
experimental data and regressions to develop equations that relate the
prior metrics to the new ones. In addition, DOE is also considering a
hybrid approach that uses both techniques.
1. Overview of Analytical Methods Approach
The analytical methods approach relies on basic equations of heat
transfer and thermodynamics, as well as established understanding of
the behavior of water heaters, to estimate the metric based on a set of
known parameters for the water heater, environment, and test pattern.
Such an approach typically yields an equation or set of equations that
can be solved to ultimately yield the metric of interest, either an
efficiency or delivery capacity. An attempt is then made to manipulate
the equations for the metrics to yield an equation that expresses the
new metrics in terms of the old metrics and other known quantities.
Analytical methods have the advantage of capturing known effects on
performance without conducting a series of experiments. Additionally, a
properly formulated relationship would be expected to be applicable to
all water heaters on the market. Analytical approaches do have some
drawbacks, however. Most notably, these methods only account for
factors that are known to impact performance and which can be readily
estimated. There may be other phenomena that affect performance that
may not be included in the known models. Second, application of these
models often require assumptions about conditions. For example, one may
need to assume a particular temperature of the water in the water
heater despite the fact that it is known that there is variation in
that temperature. Lastly, while an analytical model reduces the amount
of tests needed to generate a conversion equation, a thorough set of
experiments is still necessary to validate the model. Because it is
based on fundamental physics, though, an analytical model can typically
be extended with more confidence to a water heater that has not been
tested than would a model based purely on experimental data.
Section III.C.4 discusses approaches that DOE has considered for
developing analytical models to convert from prior metrics to new
metrics for both delivery capacity and energy efficiency of water
heaters under the uniform energy factor rating method.
2. Overview of Empirical Regression Approach
The second category of conversion factors considered by DOE is
empirical regression. In this approach, a collection of water heaters
is tested according to both the former test procedure and the new test
procedure. The resultant performance metrics, as well as other data on
the units (e.g., storage volume, input rate), are compiled, and
statistical techniques are used to create correlations that relate the
new performance metrics to the prior metrics and characteristics. No
consideration of the underlying physics is used in this approach.
Rather, it is purely a data-driven method. The advantage of this
approach is that the results are not biased by existing assumptions on
how a water heater should behave under given conditions, with the
results representing exactly what is observed in actual comparison
testing. This approach should capture all factors that affect the
energy efficiency and delivery capacity, even though those factors may
not be known a priori.
Empirical regression also has some drawbacks. One drawback is that
the resulting equations are most confidently applied to water heaters
with attributes similar to those that were tested. Consequently, to
minimize uncertainties, a large sample for testing is often appropriate
to capture more fully many of the nuances in water heater design. If
extended to units not sufficiently similar to those that were tested,
the equations may produce unacceptably large differences between
predicted and measured values if a feature on the untested model has an
effect that is not captured in the experimental data. Another major
drawback is that empirical regression is susceptible to experimental
uncertainties. While uncertainties can be reduced through careful
quality checks of experimental data, uncertainty is present in any
test. The empirical regressions, being based on many samples across
multiple different units, will further reduce the uncertainty, but some
amount of uncertainty in the regression may be unavoidable.
Section III.C.5 presents the details of the empirical regression
approaches explored by DOE.
3. Overview of Hybrid Approach
DOE has also considered a combination of the analytical methods
approach and empirical regression approach, termed a hybrid approach.
In this approach, a broad range of water heaters are tested, as would
be done in using empirical regression. An additional factor is added to
the list of attributes that is examined in the regression; this factor
uses the analytical methods to first estimate the converted value. This
estimate of the revised performance metric (maximum GPM, first-hour
rating, or UEF) for each water heater tested is then used as an
independent variable in a regression to determine the measured UEF. DOE
believes that this approach takes advantage of the ability of the
analytical methods approach to capture the major known factors that
affect the efficiency, yet adds the additional step of regression to
account for any influences that are not well described by the
analytical methods.
4. Analytical Methods Approach
a. Maximum GPM
For flow-activated water heaters, the delivery capacity under the
EF and UEF test procedures 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 a starting value of 58[emsp14][deg]F
2[emsp14][deg]F to the prescribed delivery temperature.
This flow rate is determined by the following equation:
[GRAPHIC] [TIFF OMITTED] TP30AU16.022
where V 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.
In the April 14, 2015 NOPR, DOE proposed to convert prior maximum
GPM represented values to those represented values under the amended
test procedure by accounting only for the change in Tdel
from 135[emsp14][deg]F to 125[emsp14][deg]F and for the change in the
density and specific heat of water at the new delivery temperature. 80
FR 20116, 20125. The equation above can be evaluated for both delivery
temperatures, and an expression for the maximum GPM under the uniform
efficiency descriptor (VUED) as a function of the prior maximum GPM
rating (Vex) was proposed as:
VUED = 1.147Vec
[[Page 59746]]
Northwest Energy Efficiency Alliance (NEEA) commented that the
relatively simple physics associated with water flow rate and
temperature rise made this conversion relatively robust, but that some
anomalies were present in comparing measured and analytical ratings.
(NEEA, No. 15 at p. 6) As noted in the data presented in the NOPR, DOE
found this conversion equation to match well with measured data and is
proposing it in a slightly modified version as the method to convert
from the prior maximum GPM rating to the maximum GPM rating under the
uniform energy descriptor. In the NOPR, the specific heat values were
calculated using the delivery temperatures of 125[emsp14][deg]F and
135[emsp14][deg]F for the EF and UEF test procedures, respectively. In
this SNOPR, the specific heat values are calculated using the average
of the delivery temperature (i.e., 125[emsp14][deg]F and
135[emsp14][deg]F for the EF and UEF test procedures, respectively) and
the inlet temperature (i.e., 58[emsp14][deg]F for both test
procedures). Further, the multiplier is shown to the fourth decimal
place to be more consistent with the other equations presented in this
SNOPR. Upon recalculation using appropriate values of density and
specific heat, the proposed conversion equation is:
VUED = 1.1461Vec
b. First-Hour Rating
In the April 14, 2015 NOPR, DOE indicated that it was not aware of
any analytical models that would mathematically represent the
conversion of first-hour ratings from the prior test method to the
amended test method. 80 FR 20116, 20125. NEEA questioned why DOE would
make a statement in this regard, but then go on to propose a
mathematical construct for doing so. (NEEA, No. 15 at p. 5) DOE notes
that the mathematical construct proposed to convert first-hour ratings
is based purely on regression analysis to measured data and that DOE
used the terminology ``analytical model'' to represent physics-based
equations that relate the two quantities. No comments were received
that proposed an analytical model for converting first-hour ratings, so
DOE continues to propose to use data-driven regression analysis to
convert prior first-hour ratings to amended first-hour ratings, as
discussed in section III.E.2.
c. Uniform Energy Factor
A number of changes to the 24-hour simulated-use test will alter
the represented values of water heater energy efficiency under the
prior water heater test procedures as compared to the represented
values 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[emsp14][deg]F to a delivered water temperature of
125[emsp14][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 to
the UEF, which consists of an entirely new approach for rating
efficiency.
i. Consumer Storage Water Heaters
In the April 14, 2015 NOPR, DOE proposed to use the Water Heater
Analysis Model (WHAM) as a basis for conversion. 80 FR 20116, 20126-27.
This model first determines the amount of energy input (Q) over a 24-
hour period using the following equation:
[GRAPHIC] [TIFF OMITTED] TP30AU16.023
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, Tdel is the delivered water
temperature, Tin is the inlet water temperature, 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 EF test or that required during the UEF test):
[GRAPHIC] [TIFF OMITTED] TP30AU16.024
Since the EF testing entails a prescribed Tdel
(135[emsp14][deg]F), Tin (58[emsp14][deg]F),
Ttank (135[emsp14][deg]F), Tamb
(67.5[emsp14][deg]F), and V (64.3 gallons), the two equations can be
solved for the two remaining unknowns, Q and UA. 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[emsp14][deg]F), Tin (58[emsp14][deg]F),
Ttank (125[emsp14][deg]F), Tamb
(67.5[emsp14][deg]F), and V (varies depending upon draw pattern).
DOE received a number of comments with suggested improvements to
the WHAM model. Several commenters addressed the assumption that the
average tank temperature, Ttank, is equal to the average
delivered water temperature, Tdel. Rheem indicated that the
delivered hot water temperature is greater than the average water
temperature in the tank due to stratification and that the temperature
difference needs to be accounted for more accurately in the analytical
equations. (Rheem, No. 11 at p. 6) AHRI asked DOE to reconsider the
assumption that the delivered water temperature is the same as the
stored water temperature. (AHRI, No. 13 at p. 7) Bradford White added
that the delivered temperature is typically close to the average tank
temperature for electric water heaters, but this assumption is often
not correct on gas-fired water heaters that can have a stratified tank
with an average tank temperature that is much lower than the delivered
[[Page 59747]]
temperature. (Bradford White, No. 14 at p. 2) NEEA commented that DOE
has incorporated indefensible tank temperature assumptions that are far
enough off to make the conversion factors significantly inaccurate, and
that temperature differences between the top and bottom of tall tanks
can be up to 10[emsp14][deg]F, leading to differences between
Tdel and Ttank of 5[emsp14][deg]F. (NEEA, No. 15
at p. 2)
To address these concerns, DOE examined test data and assessed the
effect of changes in Ttank on the predictions of the WHAM
analytical model. The average delivered water temperature during draws
was compared to the average tank temperature during standby periods for
a subset of the gas-fired and electric storage water heaters tested.
For consumer electric storage water heaters, the average delivered
water temperature was 6.8[emsp14][deg]F higher than the mean tank
temperature, with a standard deviation of 4.4[emsp14][deg]F. For
consumer gas-fired water heaters, the delivered water temperature was
found to be only 1.5[emsp14][deg]F greater than the average tank
temperature, with a standard deviation of 4[emsp14][deg]F. These
results raise questions about the statements by commenters that the
delivered water temperature is always much greater than the average
tank temperature. DOE's observation in these tests is that on occasion,
the delivered temperature is less than the average tank temperature
that was recorded during the standby portion of the test. That
observation is inconsistent with the commenters' suggestion, and DOE
has identified several potential reasonable explanations for the
observations. From examination of test data, it appears that there are
several periods during the test when a recovery occurs such that there
is an extended time following the recovery before the start of the next
draw, meaning that the temperature of the water in the tank has cooled
from the level it attains after a recovery. Additionally, standby
periods often occur shortly after a tank recovery, meaning that the
average tank temperature is relatively high during those periods. These
two characteristics of the tests could certainly lead to situations
where the average delivered water temperature is not always
significantly greater than the average tank temperature during standby.
Next, DOE compared measured UEF values to the predictions of the
WHAM model with different settings for Ttank. As discussed
further later in this section, these WHAM predictions were also
computed with different assumptions on the changes in recovery
efficiency and the UA values from the EF test to the UEF test. In all
cases, an assumption of Ttank = 125[emsp14][deg]F resulted
in lower root-mean-square deviations (RMSDs) between predicted and
measured values, suggesting that an assumption of Ttank =
125[emsp14][deg]F is appropriate. DOE subsequently computed WHAM
predictions with Ttank assumed down to 110[emsp14][deg]F and
found that the assumption of Ttank = 125[emsp14][deg]F held
as the best predictor of measured performance.
In summary, DOE has found that a disparity between Ttank
and Tdel exists but not to the extent that commenters have
stated. Further, using Ttank values below 125[emsp14][deg]F
within the WHAM model does not result in a better prediction of
performance. Therefore, DOE continues to propose an assumed average
tank temperature of 125[emsp14][deg]F in the WHAM calculations that are
part of the conversion of EF to UEF.
Comments were received on DOE's assumption in the WHAM model that
the recovery efficiency and the UA values do not change from the EF
test to the UEF test. Bradford White disagreed with the belief that the
UA and recovery efficiency do not change with the change in storing
water at 135[emsp14][deg]F versus delivering at 125[emsp14][deg]F.
(Bradford White, No. 14 at p. 2) NEEA commented that the recovery
efficiency of heat pump water heaters changes dramatically with
different stored water temperature and disputed DOE's contention that a
7-percent change in UA is immaterial to the WHAM calculation. (NEEA,
No. 15 at p. 3) DOE notes that the WHAM model is not used in the
conversion that has been proposed for heat pump water heaters (rather
DOE proposes the conversion derived from empirical regression), so
NEEA's comment regarding the variation in recovery efficiency of heat
pump water heaters is not germane to this issue. Lutz suggested a
different approach for determining the key performance metrics when
test conditions change from an average stored water temperature of
135[emsp14][deg]F to an average delivered water temperature of
125[emsp14][deg]F. (Lutz, No. 16 at pp. 4-6) Lutz recommends an
approach whereby a thermal standby loss and a conversion efficiency are
obtained from metrics reported in the EF test, and that these terms are
used to estimate energy consumption under the UEF test.
To evaluate these suggestions, DOE first examined test data to
estimate changes in both UA and recovery efficiency arising from
changes in test temperature. To remove any variability in these metrics
arising from changes in the procedures used to compute them, DOE
focused on a subset of tests in which the same draw pattern and
calculation procedure were used with the thermostats set according to
the EF test procedure or the UEF test procedure. By focusing on a
comparison of recovery efficiency and UA obtained during those two
tests, effects of the calculation procedure are minimized to allow the
focus to be placed on changes in tank temperature. It was found that
the UA of both gas-fired and electric storage water heaters dropped an
average of 7 percent, with a standard deviation of 3 percent. While it
was assumed that the recovery efficiency of electric storage water
heaters stays at 0.98, the recovery efficiency of gas-fired storage
water heaters was found to increase 2 percent at a delivered
temperature of 125[emsp14][deg]F compared to a stored water temperature
of 135[emsp14][deg]F. Given these values, DOE then explored how changes
in the UA value and recovery efficiency affected overall WHAM
predictions of the UEF for all water heaters tested. The UA was reduced
by 7 percent and the recovery efficiency increased 2 percent from their
values determined in the EF test. Combinations of the different
settings of UA, recovery efficiency, and Ttank were used (a
total of 8 in all), and RMSDs were computed. The RMSD was lowest under
the assumption that the UA and recovery efficiency were the same from
the EF test to the UEF test. This finding held when all water heaters
were grouped together, as well as when they were separated by fuel type
(i.e., electric and gas). While limited testing indicated that reducing
the set point temperature changed the recovery efficiency and UA
values, when applied to the entire dataset, the model produced
predictions with lower RMSDs under the assumption of no change in
recovery efficiency or UA values.
DOE also compared predictions from procedures described by Lutz to
the measured data. DOE found that the RMSD when comparing all water
heaters was essentially the same as for the WHAM model, with the RMSD
of the Lutz approach being slightly lower for electric water heaters
and slightly higher for gas-fired water heaters.
In summary, DOE found that the WHAM model provided more accurate
predictions of actual performance when Ttank is assumed to
be 125[emsp14][deg]F and the values for UA and recovery efficiency are
assumed identical under both the EF and UEF test procedures. Further,
when comparing the WHAM and Lutz methods, the RMSDs were found to be
essentially the same. Therefore, DOE proposes to use as the basis of
its conversion factors for consumer storage water heaters the WHAM
model with an
[[Page 59748]]
assumed Ttank = 125[emsp14][deg]F and an assumption that the
recovery efficiency and UA values are identical under the UEF test, as
they are under the EF test.
Rheem commented that the method of deriving the coefficients
presented in the NOPR to determine the WHAM predictions was not clear,
and AHRI stated that more information was needed on these coefficients.
(Rheem, No. 11 at p. 6; AHRI, No. 13 at p. 5) In this SNOPR, DOE is
presenting more details on the derivation of the equations it is
proposing for converting from prior metrics to the UEF. Additionally,
the coefficients are modified from the version provided in the NOPR on
account of different algebraic approaches. In the equations below,
variables with a subscript ``N'' refer to the UEF test procedure.
Variables with a subscript ``C'' refer to the EF test procedure.
The first step is to express the UEF in terms of the delivered
thermal energy and the energy consumed:
[GRAPHIC] [TIFF OMITTED] TP30AU16.025
where:
A = [rho]NCp,NVN(Tdel,N-
Tin)
B = Ttank,N-Tamb
It is assumed that the recovery efficiency and UA values are the
same for both tests. The density, [rho], is evaluated at the delivery
temperature, Tdel, and the specific heat, Cp, is
evaluated at the average of Tdel and the inlet temperature,
Tin. V is the volume delivered for the particular simulated
use profile implemented during the UEF test.
The UEF equation can be rearranged to yield the following form:
[GRAPHIC] [TIFF OMITTED] TP30AU16.026
The input power is given by the variable P. In this equation, UA is
unknown, so it must be determined from the EF test. The WHAM equation
for the energy consumed during the EF test, QC, is:
[GRAPHIC] [TIFF OMITTED] TP30AU16.027
Where:
D = [rho]cCp,cVc(Tdel,c-
Tin)
E = (Ttank,c-Tamb)
With Qc = D/EF, the equation above for UA can be
rewritten as:
[[Page 59749]]
[GRAPHIC] [TIFF OMITTED] TP30AU16.028
The values for these coefficients a, b, c, and d are presented in
Table III.3.
Table III.3--Coefficients for the Proposed Analytical UEF Conversion Factor for Consumer Storage Water Heaters
----------------------------------------------------------------------------------------------------------------
Draw pattern a b c d
----------------------------------------------------------------------------------------------------------------
Very Small...................................... 0.250266 57.5 0.039864 67.5
Low............................................. 0.065860 57.5 0.039864 67.5
Medium.......................................... 0.045503 57.5 0.039864 67.5
High............................................ 0.029794 57.5 0.039864 67.5
----------------------------------------------------------------------------------------------------------------
ii. Consumer Instantaneous Water Heater
Regarding the analytical method to convert prior represented values
for consumer instantaneous water heaters to UEF, NEEA argued that
technology differences can cause complications with analytical methods
but did not suggest any particular improvements to the methods proposed
by DOE. (NEEA, No. 15 at p. 6) AHRI stated that the determination of
N*, which is the number of draws from which heat loss occurs to the
environment, does not factor in the low-fire testing per the EF test
procedure nor the changes in the flow rate used for the test. (AHRI,
No. 8 at p. 3) DOE agrees with AHRI's observation, and is modifying its
analytical model for consumer instantaneous water heaters accordingly
to account for this change.
The loss factor represents the amount of energy stored in the
materials making up the instantaneous water heater. Its value was
obtained in the NOPR by examining test data and applying the following
equation for each test:
[GRAPHIC] [TIFF OMITTED] TP30AU16.029
In the April 2015 NOPR, DOE indicated that N* is the total number
of draws during the test scaled with respect to the standby time
occurring after the draw is completed. 80 FR 20116, 20127 (April 14,
2015). Those draws that are followed by less than one hour contribute a
fractional value to N* that is equal to the standby time in minutes
following the draw divided by 60 minutes, while the draws that are
followed by one hour or more contribute a value of one to N*. To
determine the loss factor (LF) from the equation above, data are
obtained from the EF test, but, as AHRI notes, the N* depends upon the
length of those six draws in the test. Those draws are of different
length, with the first three occurring at maximum flow rate and the
final three occurring at minimum flow rate. Therefore, the value of N*
will not be constant for all water heaters. Instead, DOE computed a
separate value of N* for each test based upon reported data on the flow
rates of each draw. From these flow rates, an estimate of the length of
each draw was obtained, and the standby time before the next draw could
be computed. Given this adjusted
[[Page 59750]]
technique, along with additional test data collected since the NOPR,
DOE computed new loss factors. It found that loss factors were
different for electric instantaneous water heaters than for gas-fired
instantaneous water heaters, so it is using different analytical
equations for gas-fired and electric models. The loss factor, LF, being
used is 0.592 Btu/[deg]F for gas-fired instantaneous water heaters, and
LF for electric instantaneous water heaters is 0.084 Btu/[deg]F.
The loss factor, N* for the new draw patterns of the UEF test, and
the test conditions imposed in the UEF test are used with the equation
above to estimate the energy consumed for a particular draw pattern for
either electric or gas-fired units. The UEF can be determined as:
[GRAPHIC] [TIFF OMITTED] TP30AU16.030
The energy delivered as hot water, Qdel (=
[rho]cpV(Tdel-Tin)), and N* depend
upon the draw pattern. The delivered temperature is assumed to be
125[emsp14][deg]F, and the ambient temperature is assumed to be
67.5[emsp14][deg]F. This equation can be rearranged by multiplying the
numerator and denominator by [eta]r/Qdel,
resulting in an equation of the form:
[GRAPHIC] [TIFF OMITTED] TP30AU16.031
Density, [rho], is computed at the delivery temperature of
125[emsp14][deg]F, and cp is computed at the average of the
delivery temperature and the inlet temperature, or 91.5[emsp14][deg]F.
The values for N* and A are provided in Table III.4.
Table III.4--N* and Coefficients for the Proposed Analytical UEF Conversion Factor for Consumer Instantaneous
Water Heaters
----------------------------------------------------------------------------------------------------------------
A
Draw pattern N* -------------------------------
Electric Gas
----------------------------------------------------------------------------------------------------------------
Very Small...................................................... 4.36 0.003819 0.026915
Low............................................................. 6.72 0.001549 0.010917
Medium.......................................................... 7.45 0.001186 0.008362
High............................................................ 7.53 0.000785 0.005534
----------------------------------------------------------------------------------------------------------------
iii. Residential-Duty Commercial Storage Water Heaters
Regarding the analytical method to convert standby loss and thermal
efficiency metrics for residential-duty commercial water heaters to
UEF, DOE received comments from Rheem, AHRI, and NEEA. NEEA stated that
there is poor agreement between predictions and measured values and
indicated that there must be some missing variables or factors, but
NEEA also commented that it is not clear what those factors might be.
(NEEA, No. 15 at p. 6) Rheem argued that DOE needs to replace the
``24'' multiplier with the difference between 24 and the burner on-time
in the 24-hour testing period to account for the actual time of heat
loss during the test. (Rheem, No. 11 at p. 6) AHRI commented that UA
losses only occur when the burner is not firing, so the 24 hours should
be reduced by the total burner on time over the simulated day. (AHRI,
No. 13 at p. 7)
In response to NEEA's comment, DOE has evaluated the factors
included in the analytical model and has not identified other terms
that would increase the accuracy of the predictions. In any case, to
the extent unknown factors are important, the use of regressions on top
of the analytical approach should account for such factors.
DOE agrees with the comments from Rheem and AHRI and is modifying
the analytical equation used to predict UEF for residential-duty water
heaters to adjust the time of application of standby losses. The new
equation proposed for estimating the energy consumption of a
residential-duty commercial water heater as a function of standby loss,
SL, thermal efficiency, Et, and input power, P, is:
[[Page 59751]]
[GRAPHIC] [TIFF OMITTED] TP30AU16.032
This equation mirrors the WHAM equation, with the second term in
the square brackets removing addition of standby loss while the burner
is operating. This step avoids double counting standby loss, as it is
already incorporated in the thermal efficiency metric while the burner
is operating. The equation can be rewritten as:
[GRAPHIC] [TIFF OMITTED] TP30AU16.033
Where A = [rho]cpV(Tdel-Tin) and F
= (Ttank-Tamb)/70.
The UEF can be determined as Qdel/Q = A/Q. Substituting
the equation for Q into this ratio yields:
[GRAPHIC] [TIFF OMITTED] TP30AU16.034
Further rearranging yields the following expression for UEF:
[GRAPHIC] [TIFF OMITTED] TP30AU16.035
Where
G = 24/A. Values for the coefficients F and G are presented in
Table III.5.
Table III.5--Coefficients for the Proposed Analytical UEF Conversion
Factor for the Residential-Duty Commercial Storage Water Heaters
------------------------------------------------------------------------
Draw pattern F G
------------------------------------------------------------------------
Very Small.............................. 0.821429 0.0043520
Low..................................... 0.821429 0.0011450
Medium.................................. 0.821429 0.0007914
High.................................... 0.821429 0.0005181
------------------------------------------------------------------------
iv. Residential-Duty Commercial Electric Instantaneous Water Heaters
For the UEF conversion, DOE tentatively concluded that given the
similarities between consumer electric instantaneous water heaters and
residential-duty commercial electric instantaneous water heaters, the
principles used to derive the consumer electric instantaneous
analytical conversion apply to the residential-duty commercial
equipment class as well. Therefore, DOE is proposing to use the
consumer electric instantaneous mathematical conversion as a starting
point for developing the residential-duty electric instantaneous
conversion, with the assumption that thermal efficiency is
approximately equal to recovery efficiency. Using this assumption, DOE
modified the consumer electric instantaneous analytical equation to the
form found below, where Et is thermal efficiency and A is
coefficient found in Table III.4. DOE proposes to use this equation as
the mathematical conversion factor for residential-duty commercial
electric instantaneous water heaters.
[GRAPHIC] [TIFF OMITTED] TP30AU16.036
5. Empirical Regression Approach
As noted, the empirical regression approach does not necessarily
assume any prior knowledge of water heater performance, so DOE sought
an approach that would allow it to consider many factors as part of its
regression equations, but would systematically eliminate any that were
not shown to have a substantive impact on the resulting performance
metrics. DOE selected a step regression method to accomplish this goal.
The step regression method examines a series of linear equations that
relate the new delivery capacity and UEF to a set of observed
independent variables, such as storage volume, input rate, EF test
procedure delivery capacity, recovery efficiency, energy factor,
thermal efficiency, or standby loss. 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
[[Page 59752]]
equation with the best fit to the actual data is chosen.
This approach eliminates factors that are not significant in
converting from the EF, TE, and SL metrics to the UEF metrics, but
could yield a ``best'' fit that might be more complicated than a
simpler equation with a marginally worse level of match to experimental
data. In addition to making the conversion equations more prone to
error in implementation, a complicated equation may also include
factors that would not be applicable to the entire population of water
heaters. DOE, therefore, 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 differences between measured values and predicted values
from the correction equations. When those differences were comparable
for two different models, DOE opted for the simpler of the two, so long
as it captured what would be expected to be 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.
In the April 2015 NOPR, DOE noted that it was not aware of an
analytical method for determining the first-hour rating, and proposed
to use an empirical regression methodology which DOE believed would be
more accurate than attempting to develop an analytical method. 80 FR
20116, 20125-28 (April 14, 2015). As noted previously in section
III.C.2, DOE did not receive any comments suggesting an alternate
methodology for determining first-hour rating, and, thus, DOE is
proposing conversion factors for those metrics and product types based
on the use of the empirical regression methodology. In addition, for
heat pump water heaters, DOE found that the conversion equations
resulting from the analytical method and hybrid regressed-analytical
approach had higher RMSD values than those resulting from the empirical
regression approach (see section III.E.2.a.ii). Therefore, as proposed
in the April 2015 NOPR, DOE is proposing a mathematical conversion for
heat pump water heaters based on the empirical regression approach. Id.
at 20132. (However, as discussed in section III.E.2.a.ii, this approach
was modified based on comments received from interested parties.)
D. Testing Conducted for the Mathematical Conversion
This section provides an overview of the consumer and residential-
duty commercial water heater markets and the test data that were
available to DOE when developing the NOPR and SNOPR conversion factors.
As discussed in the April 2015 NOPR, many stakeholders commented on
the importance of using actual test data in the derivation of the
mathematical conversion factor. 80 FR 20116, 20121 (April 14, 2015).
DOE used actual test data as part of the basis for the conversion
factors and to validate the results. The models selected for testing in
the April 2015 NOPR were chosen based on their characteristics being
generally reflective of the broader market. In response to the April
2015 NOPR, DOE received comments suggesting areas of the market that
were not adequately tested. These comments, along with DOE's responses,
are discussed in detail later in this section.
For consumer and residential-duty commercial water heaters, DOE
used the Compliance Certification Management System (CCMS) and
crosschecked it with the AHRI directory \8\ to determine the
characteristics of models available on the market. DOE conducted
additional research into manufacturers' literature to identify
characteristics related to the water heater performance, such as the
input capacity (for models not listed in the AHRI directory), venting
options, tank configuration (short or tall), NOX emissions
level, ignition type (standing or non-standing pilot), and whether the
model is certified for use in mobile homes. DOE also used the first-
hour ratings based on the EF test procedure to attempt to predict the
draw pattern that would result from the UEF test, and considered the
probable draw pattern when selecting models for testing.\9\ However,
upon testing the models according to the UEF test method, the predicted
draw pattern bin and the actual draw pattern bin did not always match
up, and therefore, the actual number of models tested to each draw
pattern was different than originally predicted. DOE attempted to test
water heaters representative of the categories listed above, from
various manufacturers, and to a similar percentage of the market across
these categories (e.g., DOE attempted to test approximately 8 percent
of both the short and tall water heater markets, resulting in more tall
units being tested due to the tall market being larger). Table III.6
shows the consumer water heater market distribution by product class,
and by various attributes that commenters suggested DOE should examine.
Table III.6 also shows the predicted and actual number of tested water
heaters, where the predicted draw pattern of the model selected may
have differed from the actual draw pattern that was used once testing
was performed. Table III.7 through Table III.12 show the consumer
market distribution by rated storage volume and input rate for various
water heater types, along with the number of units tested for the April
2015 NOPR in each category. Table III.13 shows the market distribution
for consumer heat pump water heaters by rated storage volume and EF,
along with the number of units tested for the April 2015 NOPR in each
category. Table III.14 and Table III.15 show the residential-duty
commercial water heater market distribution by input rate and rated
storage volume and the number of units tested for the April 2015 NOPR
for gas-fired and oil-fired water heaters, respectively. The numbers
provided below for the market and test distribution are for unique
basic models, as opposed to individual model numbers, due to the
addition of AHRI aggregated test data discussed further in this
section. As discussed in detail immediately below, the following tables
show the number of models tested for the NOPR. After the NOPR tables,
are tables containing the additional number of models that DOE used for
this SNOPR.
---------------------------------------------------------------------------
\8\ The numbers presented in the following tables are from the
CCMS directory as of September 2015 and the AHRI directory as of
July 2015.
\9\ As compared to the EF test procedure that relies on a single
draw pattern, the UEF test procedure employs one of four patterns,
the choice of which is determined based on the result of the first-
hour rating test (for storage water heaters) or the maximum GPM
rating test (for instantaneous water heaters).
[[Page 59753]]
Table III.6--Consumer Water Heater Test Data Used in the NOPR and Market Distribution by Product Type and Water Heater Attribute *
--------------------------------------------------------------------------------------------------------------------------------------------------------
O-S E-S
Water heater type ** G-S [dagger] [dagger][dagger] HP-S T-S G-I E-I
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Units............................................. 21/340 2/7 9/105 5/26 2/5 17/139 5/67
Venting Options:
Atmospheric......................................... 14/240 0/7 -- -- -- -- --
Power............................................... 7/99 -- -- -- -- 17/139 --
Short or Tall:
Short............................................... 7/94 -- 2/39 -- -- -- --
Tall................................................ 14/188 2/7 7/42 -- -- -- --
NOX Emissions:
Standard............................................ 2/70 -- -- -- -- -- --
Low................................................. 16/199 -- -- -- -- 6/33 --
Ultra-Low........................................... 3/71 -- -- -- -- 11/103 --
Ignition:
Standing Pilot...................................... 11/239 -- -- -- -- -- --
No Standing Pilot................................... 10/100 2/7 -- -- -- 12/103 --
Mobile Home Certified:
No.................................................. 21/326 2/7 9/99 5/26 2/5 16/138 5/67
Yes................................................. 0/14 -- 0/6 -- -- 1/1 --
Draw Pattern: [dagger][dagger][dagger]
Very Small.......................................... -- -- -- -- -- -- 5/5/67
Low................................................. 1/0/7 -- 1/3/46 0/1/1 2/2/4 1/2/2 --
Medium.............................................. 10/8/161 -- 7/6/54 2/3/13 0/0/1 7/8/56 --
High................................................ 10/13/172 1/2/7 0/0/5 1/1/12 -- 7/7/81 --
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the actual number of tested units/the number of models available on the market. In the draw pattern
rows, the first number is the number of tested units that DOE predicted would be in each draw pattern when that unit was selected based on the unit's
EF test procedure delivery capacity; the second number is the actual number of tested units in each draw pattern; and the third number is the number
of models available on the market. A ``--'' indicates that there are no models available in the category, and, thus, there were no units tested.
** Each water heater type is abbreviated using a two part designation: For the first letter(s), ``G'' means gas-fired, ``O'' means oil-fired, ``E''
means electric, ``HP'' means heat pump, and ``T'' means tabletop, and for the second letter ``S'' means storage and ``I'' means instantaneous.
[dagger] Two oil-fired storage water heaters were tested, but only one is compliant with the current energy conservation standards.
[dagger][dagger] This category includes only electric storage water heaters that use electric resistance elements, and does not include electric heat
pump water heaters.
[dagger][dagger][dagger] First-hour ratings from the EF test procedure were used to estimate draw patterns.
Table III.7--Consumer Gas-Fired Storage Test Data Used in the NOPR and Market Distribution by Input Rate and Rated Storage Volume *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) --------------------------------------------------------------------------------------------------------------------
20 28 29 30 38 40 48 50 55
--------------------------------------------------------------------------------------------------------------------------------------------------------
30................................. -- 0/1 (0%) -- 0/9 (0%) -- 0/4 (0%) -- -- --
32................................. -- -- 1/4 (25%) 0/4 (0%) -- 0/3 (0%) -- -- --
33................................. -- -- -- 0/1 (0%) -- -- -- -- --
34................................. -- -- -- -- -- 0/7 (0%) -- -- --
35................................. -- -- -- 0/12 (0%) -- 0/1 (0%) -- -- --
35.5............................... -- -- -- 0/6 (0%) -- 0/2 (0%) -- -- --
36................................. -- -- -- -- 0/1 (0%) 1/10 (10%) -- 1/11 (9%) --
37................................. -- -- -- -- -- 0/1 (0%) -- -- --
38................................. -- -- -- -- 0/1 (0%) 1/17 (6%) 0/1 (0%) 0/9 (0%) --
40................................. -- -- -- -- 0/3 (0%) 9/85 (11%) 1/4 (25%) 1/71 (1%) --
42................................. -- -- -- -- -- 0/5 (0%) -- 0/8 (0%) --
45................................. -- -- -- -- -- -- 0/1 (0%) 1/3 (33%) 0/2 (0%)
47................................. -- -- -- -- -- -- -- 1/3 (33%) --
48................................. -- -- -- -- -- -- 0/1 (0%) -- --
50................................. -- -- -- -- -- 0/2 (0%) 0/1 (0%) 1/8 (13%) 0/2 (0%)
55................................. -- -- -- -- -- -- 0/1 (0%) -- --
56................................. -- -- -- -- -- -- 0/2 (0%) -- --
58................................. -- -- -- -- -- -- -- 0/1 (0%) --
60................................. -- -- 1/1 (100%) -- -- -- 0/5 (0%) 0/9 (0%) 0/2 (0%)
62................................. -- -- -- -- -- -- -- 0/6 (0%) --
65................................. -- -- -- -- -- -- 0/5 (0%) 1/3 (33%) --
75................................. 0/1 (0%) -- -- -- -- -- -- -- --
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of models tested
is in parentheses below the counts of units tested and models. A ``--'' indicates that there are no models available in the category, and, thus, there
were no units tested.
[[Page 59754]]
Table III.8--Consumer Electric Storage Test Data Used in the NOPR and
Market Distribution by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------
All input
Rated storage volume (gallons) rates
------------------------------------------------------------------------
28...................................................... 0/6 (0%)
30...................................................... 1/27 (4%)
36...................................................... 0/1 (0%)
38...................................................... 0/6 (0%)
40...................................................... 4/29 (14%)
47...................................................... 0/2 (0%)
50...................................................... 3/26 (12%)
52...................................................... 0/2 (0%)
55...................................................... 1/6 (17%)
------------------------------------------------------------------------
* The information in this table is presented as the number of tested
units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and
models.
Table III.9--Consumer Gas-Fired Instantaneous Test Data Used in the NOPR
and Market Distribution by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------
All rated
Input rate (kBtu/h) storage
volumes
------------------------------------------------------------------------
120..................................................... 1/11 (9%)
130..................................................... 0/2 (0%)
140..................................................... 2/9 (22%)
145..................................................... 0/1 (0%)
150..................................................... 1/13 (8%)
152..................................................... 1/1 (100%)
157..................................................... 0/7 (0%)
160..................................................... 0/6 (0%)
175..................................................... 1/2 (50%)
180..................................................... 3/30 (10%)
190..................................................... 1/9 (11%)
192..................................................... 0/1 (0%)
195..................................................... 0/1 (0%)
199..................................................... 1/27 (4%)
199.9................................................... 2/6 (33%)
200..................................................... 2/13 (15%)
------------------------------------------------------------------------
* The information in this table is presented as the number of tested
units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and
models.
Table III.10--Consumer Electric Instantaneous Test Data Used for the
NOPR and Market Distribution by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------
All rated
Input rate (kW) storage
volumes
------------------------------------------------------------------------
2.4..................................................... 1/2 (50%)
3....................................................... 0/6 (0%)
3.4..................................................... 0/1 (0%)
3.5..................................................... 0/9 (0%)
4.1..................................................... 0/3 (0%)
4.8..................................................... 0/5 (0%)
5.5..................................................... 0/2 (0%)
6....................................................... 1/4 (25%)
6.5..................................................... 0/5 (0%)
7.2..................................................... 0/1 (0%)
7.5..................................................... 0/3 (0%)
8....................................................... 1/3 (33%)
8.3..................................................... 0/3 (0%)
9....................................................... 0/3 (0%)
9.5..................................................... 1/6 (17%)
10...................................................... 1/4 (25%)
11...................................................... 0/2 (0%)
11.5.................................................... 0/3 (0%)
12...................................................... 0/2 (0%)
------------------------------------------------------------------------
* The information in this table is presented as the number of tested
units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and
models.
Table III.11--Consumer Tabletop Storage Test Data Used in the NOPR and
Market Distribution by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------
All input
Rated storage volume (gallons) rates
------------------------------------------------------------------------
27...................................................... 1/2 (50%)
38...................................................... 1/1 (100%)
40...................................................... 0/2 (0%)
------------------------------------------------------------------------
* The information in this table is presented as the number of tested
units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and
models.
Table III.12--Consumer Oil-fired Storage Test Data Used in the NOPR and Market Distribution by Input Rate and
Rated Storage Volume *
----------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) -----------------------------------------------
30 32 50
----------------------------------------------------------------------------------------------------------------
90.............................................................. -- 0/2 (0%) --
104............................................................. -- 1/2 (50%) --
105............................................................. 0/2 (0%) -- 0/1 (0%)
----------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the
market. The percentage of models tested is in parentheses next to the counts of units tested and models.
Table III.13--Consumer Heat Pump Distribution Used for the NOPR by Energy Factor and Rated Storage Volume *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Energy factor -------------------------------------------------------------------------------------------------------
45 50 58 65 66 72 80 119
--------------------------------------------------------------------------------------------------------------------------------------------------------
2.2............................................. -- 1/1 (100%) -- -- -- -- -- --
2.21............................................ -- -- -- -- -- -- -- 0/1 (0%)
2.31............................................ -- -- -- 0/1 (0%) -- -- 0/1 (0%) --
2.32............................................ -- 0/1 (0%) -- -- -- -- -- --
2.33............................................ -- -- -- -- -- -- 1/1 (100%) --
2.4............................................. -- 0/1 (0%) -- -- -- -- -- --
[[Page 59755]]
2.45............................................ 0/1 (0%) 1/2 (50%) -- -- -- 0/1 (0%) 0/1 (0%) --
2.5............................................. -- -- -- -- 0/1 (0%) -- 0/1 (0%) --
2.72............................................ -- -- -- -- -- -- 0/1 (0%) --
2.74............................................ -- -- -- -- 0/1 (0%) -- -- --
2.75............................................ -- 0/1 (0%) -- -- -- -- -- --
2.9............................................. -- 0/1 (0%) -- -- -- -- 0/1 (0%) --
3.05............................................ -- -- 0/1 (0%) -- -- -- -- --
3.07............................................ -- -- -- -- -- -- 0/1 (0%) --
3.1............................................. -- 0/1 (0%) -- -- -- -- 0/1 (0%) --
3.17............................................ -- -- -- -- 0/1 (0%) -- -- --
3.24............................................ -- 0/1 (0%) -- -- -- -- -- --
3.39............................................ -- -- -- -- -- -- 0/1 (0%) --
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of models tested
is in parentheses below the counts of units tested and models. A ``--'' indicates that there are no models available in the category, and, thus, there
were no units tested.
Table III.14--Residential-Duty Commercial Gas-fired Storage Test Data Used in the NOPR and Market Distribution by Input Rate and Rated Storage Volume
*\,\**
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) ------------------------------------------------------------------------------------------------------------------------
34 40 50 55 60 74 75 80 98 100 119
--------------------------------------------------------------------------------------------------------------------------------------------------------
75............................. -- -- -- -- -- -- 0/1 (0%) -- -- -- --
75.1........................... -- -- -- -- -- 0/3 (0%) 0/3 (0%) -- 0/2 (0%) 0/1 (0%) --
76............................. -- -- 2/4 (50%) -- 0/2 (0%) -- 2/21 0/2 (0%) -- 0/3 (0%) --
(10%)
78............................. -- -- -- 0/1 (0%) -- -- -- -- -- -- --
80............................. -- -- -- 0/2 (0%) -- 0/1 (0%) 0/1 (0%) -- -- 1/1 --
(100%)
85............................. -- -- -- -- -- -- -- -- -- 0/3 (0%) --
88............................. -- -- -- -- -- -- -- -- -- 0/3 (0%) --
90............................. -- -- -- -- -- -- -- -- 0/1 (0%) -- --
91.3........................... -- 0/1 (0%) -- -- -- -- -- -- -- -- --
98............................. -- -- 0/2 (0%) -- -- -- -- -- -- -- --
100............................ 0/1 (0%) -- 0/1 (0%) 0/3 (0%) -- -- 0/2 (0%) 0/2 (0%) -- -- 0/2 (0%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of models tested
is in parentheses below the counts of units tested and models. A ``--'' indicates that there are no models available in the category, and, thus, there
were no units tested.
** Seven data points were presented in the April 2015 NOPR, but two units were of the same basic model, and three units were tested to the incorrect
input rate. DOE has removed these data points from the analysis.
Table III.15--Residential-Duty Commercial Oil-fired Storage Test Data Used in the NOPR and Market Distribution
by Input Rate and Rated Storage Volume *\,\**
----------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) -----------------------------------------------
30 50 70
----------------------------------------------------------------------------------------------------------------
119............................................................. 0/2 (0%) 0/1 (0%) 0/1 (0%)
140............................................................. -- 0/1 (0%) --
----------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the
market. The percentage of models tested is in parentheses below the counts of units tested and models. A ``--
'' indicates that there are no models available in the category, and, thus, there were no units tested.
In addition, AHRI submitted test results for testing conducted
under both the EF and UEF test methods by its member manufacturers.
(AHRI, No. 9) As using additional data points will generally reduce the
uncertainty in the statistical modeling used to generate the conversion
factor, DOE has incorporated the test data submitted by AHRI in its
analysis for this SNOPR. DOE also conducted additional testing, which
was completed after the publication of the April 2015 NOPR, and is
including the results in this SNOPR. Table III.16 shows the consumer
market distribution by product class and attributes that commenters
suggested DOE examine, along with the number of units tested for the
development of this SNOPR in each category. Table III.17 through Table
III.21 show the consumer market
[[Page 59756]]
distribution by rated storage volume and input rate for various water
heater categories and the number of units tested for this SNOPR in each
category. Table III.22 shows the consumer heat pump market distribution
by rated storage volume and EF and the number of units tested for this
SNOPR in each category. Table III.23 and Table III.24 show the
residential-duty commercial market distribution by input rate and rated
storage volume and the number of units tested for this SNOPR in each
category. AHRI did not supply model numbers in its data, so some
percentages in the tables below are greater than 100 percent,
suggesting that DOE and AHRI have data on the same water heaters. Both
the DOE and AHRI data sets contain some test points that are from
different water heaters of the same model. These models were only
counted once in the tables below, and the test data were averaged into
a single data point in the conversion factor derivation.
Table III.16--Consumer Market Distribution and Test Data Used for this SNOPR by Product Type and Water Heater Attribute*
--------------------------------------------------------------------------------------------------------------------------------------------------------
O-S E-S
Water heater type ** G-S [dagger] [dagger][dagger] HP-S T-S G-I E-I
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Units............................................. 118/340 2/7 46/105 16/26 3/5 53/139 5/67
Venting Options
Atmospheric......................................... 84/240 0/7 -- -- -- -- --
Power............................................... 33/99 -- -- -- -- 53/139 --
Short or Tall
Short............................................... 42/94 -- 11/39 -- -- -- --
Tall................................................ 75/188 2/7 19/42 -- -- -- --
NOX Emissions
Standard............................................ 13/70 -- -- -- -- -- --
Low................................................. 81/199 -- -- -- -- 9/33 --
Ultra-Low........................................... 24/71 -- -- -- -- 44/103 --
Ignition
Standing Pilot...................................... 76/239 -- -- -- -- --
No Standing Pilot................................... 41/100 2/7 -- -- -- 48/103 --
Mobile Home Certified
No.................................................. 118/326 2/7 46/99 16/26 3/5 52/138 5/67
Yes................................................. 0/14 -- 0/6 -- -- 1/1 --
Draw Pattern [dagger][dagger][dagger]
Very Small.......................................... -- -- -- -- -- -- 5/5/67
Low................................................. 4/2/7 -- 12/13/46 0/1/1 3/2/4 1/2/2 --
Medium.............................................. 55/55/161 -- 31/32/54 7/9/13 0/1/1 13/21/56 --
High................................................ 59/61/172 1/2/7 4/1/5 6/6/12 -- 18/30/81 --
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the actual number of tested units/the number of models available on the market. In the draw pattern
rows, the first number is the number of tested units that DOE predicted would be in each draw pattern when that unit was selected based on the unit's
EF test procedure delivery capacity; the second number is the actual number of tested units in each draw pattern; and the third number is the number
of models available on the market. A ``--'' indicates that there are no models available in the category, and, thus, there were no units tested.
** Each water heater type is abbreviated using a two part designation: For the first letter(s) ``G'' means gas-fired, ``O'' means oil-fired, ``E'' means
electric, ``HP'' means heat pump, and ``T'' means tabletop, and for the second letter ``S'' means storage and ``I'' means instantaneous.
[dagger] Two oil-fired storage water heaters were tested, but only one is compliant with the current energy conservation standards.
[dagger][dagger] In this table, this category includes only electric storage water heaters that use electric resistance elements, and does not include
electric heat pump water heaters.
[dagger][dagger] First-hour ratings from the EF test procedure were used to estimate draw patterns.
Table III.17--Consumer Gas-fired Storage Distribution and Test Data Used for This SNOPR by Input Rate and Rated Storage Volume *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) --------------------------------------------------------------------------------------------------------------------
20 28 29 30 38 40 48 50 55
--------------------------------------------------------------------------------------------------------------------------------------------------------
30................................. -- 1/1 (100%) -- 6/9 (67%) -- 1/4 (25%) -- -- --
32................................. -- -- 2/4 (50%) 3/4 (75%) -- 0/3 (0%) -- -- --
33................................. -- -- -- 1/1 (100%) -- -- -- -- --
34................................. -- -- -- -- -- 3/7 (43%) -- -- --
35................................. -- -- -- 0/12 (0%) -- 0/1 (0%) -- -- --
35.5............................... -- -- -- 2/6 (33%) -- 0/2 (0%) -- -- --
36................................. -- -- -- -- 1/1 (100%) 4/10 (40%) -- 3/11 (27%) --
37................................. -- -- -- -- -- 0/1 (0%) -- -- --
38................................. -- -- -- -- 0/1 (0%) 8/17 (47%) 0/1 (0%) 5/9 (56%) --
40................................. -- -- -- -- 1/3 (33%) 29/85 (34%) 3/4 (75%) 24/71 (34%) --
42................................. -- -- -- -- -- 0/5 (0%) -- 3/8 (38%) --
45................................. -- -- -- -- -- -- 0/1 (0%) 2/3 (67%) 1/2 (50%)
47................................. -- -- -- -- -- -- -- 1/3 (33%) --
48................................. -- -- -- -- -- -- 0/1 (0%) -- --
50................................. -- -- -- -- -- 0/2 (0%) 1/1 (100%) 3/8 (38%) 1/2 (50%)
55................................. -- -- -- -- -- -- 0/1 (0%) -- --
56................................. -- -- -- -- -- -- 0/2 (0%) -- --
58................................. -- -- -- -- -- -- -- 0/1 (0%) --
[[Page 59757]]
60................................. -- -- 2/1 (200%) -- -- -- 1/5 (20%) 0/9 (0%) 0/2 (0%)
62................................. -- -- -- -- -- -- -- 1/6 (17%) --
65................................. -- -- -- -- -- -- 2/5 (40%) 2/3 (67%) --
75................................. 0/1 (0%) -- -- -- -- -- -- -- --
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of models tested
is in parentheses below the counts of units tested and models. A ``--'' indicates that there are no models available in the category, and, thus, there
were no units tested.
Table III.18--Consumer Electric Storage Distribution and Test Data Used
for This SNOPR by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------
All input
Rated storage volume (gallons) rates
------------------------------------------------------------------------
28...................................................... 5/6 (83%)
30...................................................... 6/27 (22%)
36...................................................... 0/1 (0%)
38...................................................... 2/6 (33%)
40...................................................... 12/29 (41%)
47...................................................... 0/2 (0%)
50...................................................... 15/26 (58%)
52...................................................... 1/2 (50%)
55...................................................... 4/6 (67%)
------------------------------------------------------------------------
* The information in this table is presented as the number of tested
units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and
models.
Table III.19--Consumer Gas-Fired Storage Distribution and Test Data Used
for This SNOPR by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------
All rated
Input rate (kBtu/h) storage
volumes
------------------------------------------------------------------------
120..................................................... 4/11 (36%)
130..................................................... 0/2 (0%)
140..................................................... 5/9 (56%)
145..................................................... 0/1 (0%)
150..................................................... 4/13 (31%)
152..................................................... 3/1 (300%)
157..................................................... 2/7 (29%)
160..................................................... 0/6 (0%)
175..................................................... 1/2 (50%)
180..................................................... 9/30 (30%)
190..................................................... 5/9 (56%)
192..................................................... 0/1 (0%)
195..................................................... 0/1 (0%)
199..................................................... 6/27 (22%)
199.9................................................... 10/6 (167%)
200..................................................... 2/13 (15%)
------------------------------------------------------------------------
* The information in this table is presented as the number of tested
units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and
models.
Table III.20--Consumer Tabletop Storage Distribution and Test Data Used
for This SNOPR by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------
All input
Rated storage volume (gallons) rates
------------------------------------------------------------------------
27...................................................... 1/2 (50%)
38...................................................... 1/1 (100%)
40...................................................... 1/2 (50%)
------------------------------------------------------------------------
* The information in this table is presented as the number of tested
units/the number of models available on the market. The percentage of
models tested is in parentheses next to the counts of units tested and
models.
Table III.21--Consumer Oil-Fired Storage Distribution and Test Data Used for This SNOPR by Input Rate and Rated
Storage Volume *
----------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) -----------------------------------------------
30 32 50
----------------------------------------------------------------------------------------------------------------
90.............................................................. .............. 0/2 (0%) ..............
104............................................................. .............. 1/2 (50%) ..............
105............................................................. 0/2 (0%) .............. 0/1 (0%)
----------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the
market. The percentage of models tested is in parentheses next to the counts of units tested and models.
Table III.22--Consumer Heat Pump Distribution and Test Data Used for This SNOPR by Energy Factor and Rated Storage Volume *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Energy factor -----------------------------------------------------------------------------------------------
45 50 58 65 66 72 80 119
--------------------------------------------------------------------------------------------------------------------------------------------------------
2.2..................................................... -- 1/1 (100%) -- -- -- -- -- --
2.21.................................................... -- -- -- -- -- -- -- 1/1 (100%)
2.31.................................................... -- -- -- 1/1 (100%) -- -- 1/1 (100%) --
2.32.................................................... -- 0/1 (0%) -- -- -- -- -- --
2.33.................................................... -- -- -- -- -- -- 2/1 (200%) --
[[Page 59758]]
2.4..................................................... -- 2/1 (200%) -- -- -- -- -- --
2.45.................................................... 0/1 (0%) 1/2 (50%) -- -- -- 0/1 (0%) 0/1 (0%) --
2.5..................................................... -- -- -- -- 0/1 (0%) -- 0/1 (0%) --
2.72.................................................... -- -- -- -- -- -- 1/1 (100%) --
2.74.................................................... -- -- -- -- 0/1 (0%) -- -- --
2.75.................................................... -- 0/1 (0%) -- -- -- -- -- --
2.9..................................................... -- 1/1 (100%) -- -- -- -- 1/1 (100%) --
3.05.................................................... -- -- 0/1 (0%) -- -- -- -- --
3.07.................................................... -- -- -- -- -- -- 0/1 (0%) --
3.1..................................................... -- 0/1 (0%) -- -- -- -- 1/1 (100%) --
3.17.................................................... -- -- -- -- 0/1 (0%) -- -- --
3.24.................................................... -- 0/1 (0%) -- -- -- -- -- --
3.39.................................................... -- 1/0 ** -- -- -- -- 0/1 (0%) --
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of models tested
is in parentheses below the counts of units tested and models. A ``--'' indicates that there are no models available in the category, and, thus, there
were no units tested.
** AHRI supplied data for this model which is not contained in the version of the CCMS and AHRI databases used for this SNOPR. Due to the high rated EF,
DOE believes this unit to have recently come on to the market.
Table III.23--Residential-Duty Commercial Gas-Fired Storage Test Data Used for This SNOPR and Market Distribution by Input Rate and Rated Storage Volume *
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) -----------------------------------------------------------------------------------------------------------------------------------
34 40 50 55 60 74 75 80 98 100 119
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
75.......................................................... -- -- -- -- -- -- 0/1 (0%) -- -- -- --
75.1........................................................ -- -- -- -- -- 2/3 (67%) 1/3 (33%) -- 3/2 (150%) 0/1 (0%) --
76.......................................................... -- -- 6/4 (150%) -- 0/2 (0%) -- 2/21 (10%) 0/2 (0%) -- 0/3 (0%) --
78.......................................................... -- -- -- 0/1 (0%) -- -- -- -- -- -- --
80.......................................................... -- -- -- 0/2 (0%) -- 0/1 (0%) 1/1 (100%) -- -- 1/1 (100%) --
85.......................................................... -- -- -- -- -- -- -- -- -- 1/3 (33%) --
88.......................................................... -- -- -- -- -- -- -- -- -- 0/3 (0%) --
90.......................................................... -- -- -- -- -- -- -- -- 0/1 (0%) -- --
91.3........................................................ -- 0/1 (0%) -- -- -- -- -- -- -- -- --
98.......................................................... -- -- 0/2 (0%) -- -- -- -- -- -- -- --
100......................................................... 0/1 (0%) -- 1/1 (100%) 0/3 (0%) -- -- 1/2 (50%) 0/2 (0%) -- -- 0/2 (0%)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the market. The percentage of models tested is in parentheses below the counts of
units tested and models. A ``--'' indicates that there are no models available in the category, and, thus, there were no units tested.
Table III.24--Residential-Duty Commercial Oil-Fired Storage Test Data Used for This SNOPR and Market
Distribution by Input Rate and Rated Storage Volume *
----------------------------------------------------------------------------------------------------------------
Rated storage volume (gallons)
Input rate (kBtu/h) -----------------------------------------------
30 50 70
----------------------------------------------------------------------------------------------------------------
119............................................................. 0/2 (0%) 0/1 (0%) 0/1 (0%)
140............................................................. -- 1/1 (100%) --
----------------------------------------------------------------------------------------------------------------
* The information in this table is presented as the number of tested units/the number of models available on the
market. The percentage of models tested is in parentheses below the counts of units tested and models. A ``--
'' indicates that there are no models available in the category, and, thus, there were no units tested.
As noted above, DOE received a number of comments suggesting types
of water heaters for which the commenters said DOE should incorporate
additional data for the development of the conversion factors.
Specifically, AHRI and Rheem stated that more short units should be
tested and in particular, electric short units. (AHRI, No. 13 at p. 5;
Rheem, No. 11 at p. 7) For the SNOPR, the percentage of gas-fired and
electric short water heater models on the market that have been tested
has increased from 7 percent to 45 percent and from 5 percent to 28
percent, respectively, as compared to the April 2015 NOPR. DOE notes
that these percentages are based on identification in manufacturer
literature, as there is no consistent, objective criteria for
identifying short and tall models across manufacturers. DOE believes
that the models tested are representative of ``short'' models available
on the market.
AHRI stated that units subject to the low draw pattern for the
consumer electric storage category were not adequately tested. (AHRI,
No. 13 at p. 5) Rheem also stated that not enough consumer electric
storage units were tested, but that more testing for the high-draw-
pattern category was needed. (Rheem, No. 13 at p. 7) As noted above,
[[Page 59759]]
the draw pattern classification for DOE's test unit selection was based
upon the first-hour ratings based on the EF test procedure, as the
first-hour ratings under the UEF test procedure are not readily
available in published literature. However, the actual draw pattern for
each unit tested was found experimentally through testing for the
first-hour rating under the UEF test method prior to conducting the UEF
simulated-use test. For the SNOPR, the percentage of electric low- and
high-draw-pattern water heaters on the market that have been tested has
increased from 7 percent to 28 percent and from 0 percent to 20
percent, respectively. These percentages are based on the number of
units that were determined through testing to be in a draw pattern bin
as compared to the number of models that would be predicted to be in
that draw pattern bin.
Rheem stated that no low-draw-pattern consumer gas-fired water
heaters were tested. (Rheem, No. 13 at p. 7) DOE predicted seven of the
340 (i.e., 2.1 percent) gas-fired water heater models on the market to
be in the low-draw-pattern bin based on their EF test procedure first-
hour rating. For the NOPR, one unit was tested with an expected low-
draw-pattern based on its first-hour rating under the EF test
procedure, but that unit's tested first-hour rating under the new UEF
procedure placed it into the medium-draw-pattern bin. Subsequently, two
consumer gas-fired water heaters were supplied in the AHRI dataset and
tested to the low-draw-pattern bin under the UEF first-hour rating
test. Therefore, two low-draw-pattern tests are now available and were
included in the analysis.
Rheem stated that there were no tests of consumer gas-fired storage
water heaters above 55 gallons. (Rheem, No. 13 at p. 7) In response,
DOE notes that as of the time of this analysis, there are no water
heaters on the market which would fall into this category.
AHRI and Rheem suggested that more ultra-low NOX units
should be tested. (AHRI, No. 13 at p. 5; Rheem, No. 11 at p. 7) For the
SNOPR, the percentage of ultra-low NOX gas-fired water
heaters on the market that have been tested has increased from 4
percent to 34 percent.
AHRI, GE, and Rheem suggested that more high-EF heat pump units
should be tested. (AHRI, No. 8 at p. 4; GE, No. 12 at p. 1; Rheem, No.
11 at p. 7) For the SNOPR, the percentage of high-EF (i.e., EF greater
than 2.7) heat pump water heaters on the market that have been tested
has increased from 0 percent to 42 percent.
AHRI and Rheem commented that the sample size for the residential-
duty gas-fired storage category was too small. (AHRI, No. 13 at p. 6;
Rheem, No. 11 at p. 7) AHRI and Rheem also stated that no residential-
duty units in the high-input range were tested. (AHRI, No. 8 at p. 4;
Rheem, No. 11 at p. 7) For the SNOPR, the percentage of residential-
duty commercial gas-fired storage water heaters on the market that have
been tested has increased from 7 percent to 28 percent, and the
percentage of high-input (i.e., input rate greater than 90,000 Btu/h)
units has increased from 0 percent to 14 percent.
1. Repeatability
In response to the April 2015 NOPR, commenters stated that the
repeatability of the UEF test procedure was not analyzed. (AHRI, No. 8
at p. 5; Rheem, No. 11 at p. 6) In response, DOE acknowledges that each
water heater was tested once, and repeat tests of the same unit were
not conducted by DOE. During its test procedure rulemaking to establish
the UEF test method, stakeholders did not raise concerns regarding
repeatability, and, therefore, DOE did not specifically evaluate this
issue during testing conducted for the NOPR. However, AHRI submitted
data that appears to show the variations in the experimental results
from testing a given unit are unlikely to contribute more than a de
minimis amount of uncertainty to the overall regression. One consumer
electric storage water heater (Test ID No. 1-61 and 1-62) and one
consumer gas-fired instantaneous water heater (Test ID No. 1-83 and 1-
84) were tested multiple times. For the consumer electric storage water
heater, the only difference between the two tests was the result of the
EF test procedure's first-hour rating test (difference of 3 gallons).
For the gas-fired instantaneous water heater, the differences in the EF
test procedure maximum GPM, EF, UEF test procedure maximum GPM, and UEF
results were 0.019 gpm, 0.0017, 0.0002 gpm, and 0.0012, respectively.
(AHRI, No. 9 Attachment) These data suggest that the EF and UEF test
procedures are repeatable.
For this SNOPR, DOE conducted additional testing that allowed DOE
to further examine the repeatability of the test method. DOE tested
eight units, two different units of one model and 3 different units of
2 other models. Because the different units may have slightly different
EF or UEF characteristics, the variability in these results is an upper
bound for the variability introduced by the test methods themselves.
The variability was similar for all three, and DOE has no reason to
think the test methods would produce significantly different levels of
variability for other types of water heaters. The results of the
testing are shown in Table III.25. The standard deviations of the EF
and UEF tests for models 1, 2, and 3 are 0.0018 and 0.0035, 0.0033 and
0.0044, and 0.0149 and 0.0116, respectively. These standard deviations
are all within the same magnitude for each model and for the case of
model 3 the UEF standard deviation is less than EF. The results
indicate a reasonable level of repeatability in the test procedure.
Table III.25--Results for Repeatability Testing for EF and UEF Test Methods
----------------------------------------------------------------------------------------------------------------
Model Unit Rated EF Tested EF Tested UEF
----------------------------------------------------------------------------------------------------------------
1............................................... 1 0.95 0.947 .949
1............................................... 2 0.95 0.949 .944
2............................................... 1 0.95 0.937 .903
2............................................... 2 0.95 0.940 .909
2............................................... 3 0.95 0.934 .901
3............................................... 1 0.95 0.908 .914
3............................................... 2 0.95 0.932 .898
3............................................... 3 0.95 0.905 .892
----------------------------------------------------------------------------------------------------------------
[[Page 59760]]
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 prior 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 would warrant separate conversion equations. DOE
investigated attributes such as: (1) NOX emission level; (2)
short or tall configuration; (3) vent type; (4) standing pilot versus
electronic ignition; (5) whether condensing or heat pump technology is
used; and (6) whether the unit is tabletop. The RMSD between the
measured values and the values obtained through various conversion
methods was compared. The conversion approach with the lowest
cumulative RMSD value for a particular fuel type was considered to be
the best candidate for the conversion equation.
In the April 2015 NOPR, DOE proposed to adopt different conversion
equations based on the level of NOX emissions. 80 FR 20116,
20129-30 (April 14, 2015). 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 less than 40 ng/J 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). AHRI commented that separate conversions for standard and
low-NOX water heaters are not needed. (AHRI, No. 8 at p. 4)
As a result, DOE re-examined the data to determine the variability of
the conversions when considering standard and low-NOX water
heaters together, and separately from ultra-low-NOX water
heaters. DOE found that the combined approach recommended by AHRI
slightly reduces the variability of the conversion equations, and,
thus, the Department has included standard and low-NOX water
heaters in a single set of conversion equations in this supplemental
proposal. The proposal continues to treat ultra-low-NOX
water heaters separately, because an ultra-low-NOX burner
has a fundamentally different design than standard and low-
NOX burners and the resulting RMSD values are lower for each
category when separated.
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 ``short'' are actually taller than
units labeled as ``tall.'' In the NOPR, DOE requested comment on how
manufacturers determine whether a unit is short or tall. 80 FR 20116,
20129 (April 14, 2015). No response was received related to this
inquiry, so DOE considered manufacturer literature in determining
whether a model was ``tall'' or ``short,'' although as noted, the
criteria for classification was not always consistent across
manufacturers. DOE examined separate conversions for tall and short
water heaters based on their identification in manufacturer literature;
however, DOE ultimately did not propose separate conversions because it
did not yield materially different results and is not based on discrete
design characteristics that are consistent across all manufacturers.
As explained in the April 2015 NOPR, 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 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 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, in terms of the comparison
between EF and UEF, between atmospheric and direct vent water heaters
and also between power and power-direct vent. For these reasons DOE
grouped atmospheric and direct into the atmospheric configuration and
power and power-direct into the power configuration. Similarly, DOE
determined that there was not a significant difference between
electronic ignition and standing pilot units and grouped those together
for this conversion. 80 FR 20116, 20129-30 (April 14, 2015).
Rheem commented that DOE should test ultra-low-NOX
consumer gas-fired storage water heaters that use a power vent to
determine whether a different UEF conversion factor is warranted to
differentiate between the different vent types of ultra-low-
NOX water heaters. (Rheem, No. 11 at p. 7) AHRI submitted
test data for 17 ultra-low-NOX consumer gas-fired water
heaters: 9 that are atmospherically vented and 8 that are power vented.
DOE analyzed separating the ultra-low-NOX consumer gas-fired
storage category into atmospherically vented and power vented
categories, and found that the RMSD value decreased by less than 0.001
when separated. DOE tentatively considers a change in RMSD to be
negligible if it is less than one unit (0.01 for EF and UEF, 0.1 for
maximum GPM, and 1.0 for first-hour rating). DOE has tentatively
decided that this decrease is not significant enough to justify a
separate conversion, given the additional complexity of separating
these products by vent type.
In the April 2015 NOPR, DOE tentatively concluded that tabletop
units were not significantly different from electric resistance storage
water heaters and considered them together for the purposes of
developing the mathematical conversion. 80 FR 20116, 20132 (April 14,
2015). Upon further consideration, DOE believes that tabletop units,
due to their efficiency ratings being well below those of traditional
electric storage water heaters, may react differently to the UEF test
procedure than traditional electric storage water heaters. Therefore,
DOE has tentatively decided to propose separate conversions for
tabletop and electric resistance water heaters in this SNOPR.
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.
In response to the April 2015 NOPR, Rheem commented generally that
DOE did not specify how it determined whether the proposed UEF
conversion factors and minimum standards were acceptable and do not
effectively amend the energy conservation standards. (Rheem, No. 11 at
p. 5) AHRI stated that the tested UEF values do not align with the
converted UEF values. (AHRI, No. 13 at p. 4) Regarding the conversion
factors, DOE examined multiple
[[Page 59761]]
approaches and, in most cases, chose the approach that yielded the
lowest RMSD value. For certain conversions, DOE chose an approach where
the RMSD value was slightly higher, but negligibly so, in favor of a
simpler approach to the conversion. (As stated in section III.E.1, DOE
tentatively considers a change in RMSD to be negligible if it is less
than one unit (0.01 for EF and UEF, 0.1 for maximum GPM, and 1.0 for
first-hour rating).) In examining whether the proposed conversion
factors are appropriate, DOE considered its certification policies for
water heaters contained in 10 CFR part 429. Recognizing the variation
in materials, the manufacturing process, and testing, DOE provides
bounds on acceptable representations of efficiency for certifying
represented values. DOE requires the manufacturer to rate the
efficiency of a basic model between the Federal energy conservation
standard and up to the lower of the mean of the sample or the 95-
percent lower confidence limit divided by 0.9. 10 CFR 429.17. DOE
examined the variability between the tested EF and the rated EF for
each model tested for this rulemaking by determining the standard
deviation for each sample grouping (i.e., the sample data points
included for each conversion equation) in order to estimate the amount
of variation allowed by DOE's rating requirements at 10 CFR 429.17. DOE
then compared the standard deviation of the tested EF values to the
RMSD of predicted UEF values.\10\ For all product classes, the RMSD of
the UEF values was less than or equal to the standard deviation of the
EF values when rounded to the nearest 0.01, indicating that the
variability of the predicted conversion values is less than or equal to
that of the tested EF values observed in a sample of models under the
current test procedure. In addition, DOE's approach to ensuring the
energy conservation standards are not effectively amended is discussed
further in section III.E.3.
---------------------------------------------------------------------------
\10\ DOE examined RMSD as the measure of the variability between
tested and predicted UEF values, as it is a common measure of the
accuracy of a model and is often used to compare predicted and
measured values. In comparing measured versus rated values for EF,
DOE examined standard deviation, which represents the variability of
a sample in relation to the mean of that sample. In this case, DOE
assumes that the rated EF will represent the mean of the sample. DOE
recognizes that under its certification regulation, rated EF may
actually be different from the mean of a sample. For purposes of
assessing the scope of variability, that difference will not be
important.
---------------------------------------------------------------------------
NEEA stated that the April 2015 NOPR did not deliver a set of
mathematical conversion factors that would enable the marketplace (or
anyone else) to rely on the resulting UEF ratings or the proposed UEF
standards equations that are derived from those ratings. (NEEA, No. 15
at p. 2) DOE disagrees with NEEA, and believes that the UEF values
predicted using the mathematical conversions are reasonable, as
evidenced by the resulting RMSD values. RMSD is a measure of the
differences between values predicted by a model and those actually
observed. As discussed above, the RMSD values for the predicted UEF
were less than or equal to the standard deviation of the tested EF
values for each class of water heater, suggesting that the mathematical
conversion factors presented are reasonably accurate.
a. Consumer Storage Water Heaters
i. Test Results
In total, DOE has conducted testing of 55 consumer storage water
heater models using both the EF and UEF test procedures, and likewise,
AHRI has supplied test data for 130 consumer storage water heater
models using both the EF and UEF test procedures.11 12 Table
III.26 presents the test data used to derive the consumer storage water
heater conversion factors. Table III.27 shows the water heater
attributes by unit. DOE notes that 1 of the 2 oil-fired storage water
heaters, 1 of the 46 electric storage water heaters, and 3 of the 118
gas-fired storage water heaters that were included in the testing and
analysis had manufacturer self-declared ratings below the current
energy conservation standards (compliance required April 16, 2015).
Although the rated efficiency of these water heaters are below the
energy conservation standards, DOE believes it is appropriate to use
data from these models, because the difference between the relevant
parameters under the new and old test procedures (i.e., first-hour
rating, EF, and UEF) are likely to be similar to those of a model rated
to meet the energy conservation standards. Thus, DOE believes this
model is relevant for evaluating the conversion factor which is
intended to establish the relationship between ratings under the UEF
and EF test procedures. Therefore, DOE has considered these models in
its analysis for determining the mathematical conversion factors.
---------------------------------------------------------------------------
\11\ The AHRI submitted data points 2-5 and 2-6 were not used in
this analysis as the reported recovery efficiencies were 98 percent
and not calculated from test data.
\12\ If multiple tests were conducted on either the same unit or
same basic model of a water heater, the results were averaged to
produce the values reported in this SNOPR. In one instance within
the AHRI-submitted data for consumer storage water heaters, three
tests were conducted, where two tests were conducted on the same
unit and another test was conducted on a unit of the same basic
model. The two tests of the same unit were averaged, and this value
was then averaged with the results of the test of the unit of the
same basic model.
Table III.26--Consumer Storage Water Heater Test Data
--------------------------------------------------------------------------------------------------------------------------------------------------------
Prior
Storage Input Prior FHR Updated recovery
CS No. AHRI No. Type volume rate (Btu/ (gal) FHR efficiency EF UEF
(gal) h) (gal) (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1............................... N/A................ Gas............... 36.8 40,000 73.8 104.2 92.2 0.790 0.802
2............................... N/A................ Gas............... 45.6 39,800 91.0 85.0 96.2 0.836 0.826
3............................... N/A................ Gas............... 37.8 39,400 74.5 80.9 80.5 0.692 0.714
4............................... N/A................ Gas............... 49.4 44,100 97.5 86.7 78.8 0.610 0.634
5............................... N/A................ Gas............... 38.2 38,300 71.4 64.8 76.4 0.625 0.600
6............................... N/A................ Gas............... 38.0 40,500 73.5 75.7 83.6 0.702 0.719
7............................... N/A................ Gas............... 37.9 40,100 80.2 63.8 83.6 0.711 0.669
8............................... N/A................ Gas............... 47.2 50,600 95.2 87.7 78.3 0.608 0.635
9............................... N/A................ Gas............... 38.1 39,300 71.9 77.8 75.8 0.607 0.635
10.............................. N/A................ Gas............... 27.8 31,600 59.0 64.4 78.8 0.619 0.605
11.............................. N/A................ Gas............... 38.1 40,200 74.9 70.9 78.5 0.618 0.570
12.............................. N/A................ Gas............... 38.8 32,400 68.7 65.1 77.9 0.664 0.624
13.............................. N/A................ Gas............... 38.4 39,800 70.2 74.1 80.4 0.673 0.654
14.............................. N/A................ Gas............... 27.7 59,600 96.9 94.6 78.2 0.702 0.718
[[Page 59762]]
15.............................. N/A................ Gas............... 38.4 36,300 66.0 68.1 85.0 0.699 0.677
16.............................. N/A................ Gas............... 47.9 49,900 90.2 81.1 81.1 0.674 0.676
17.............................. N/A................ Gas............... 47.8 64,600 108.0 108.8 79.8 0.654 0.680
18.............................. N/A................ Gas............... 38.4 40,000 67.0 81.1 80.5 0.601 0.628
19.............................. N/A................ Gas............... 37.8 39,700 70.2 87.0 80.2 0.610 0.641
20.............................. N/A................ Gas............... 38.1 40,300 68.3 64.8 74.1 0.602 0.598
21.............................. N/A................ Gas............... 28.6 33,000 56.1 70.6 82.2 0.610 0.561
22.............................. N/A................ Gas............... 48.1 36,000 92.1 88.2 80.6 0.630 0.662
23.............................. N/A................ Gas............... 47.7 40,500 94.2 84.0 72.5 0.547 0.640
24.............................. N/A................ Gas............... 26.5 29,500 50.4 51.5 80.8 0.644 0.603
25.............................. N/A................ Gas............... 45.6 39,700 87.9 83.2 77.8 0.593 0.617
26.............................. N/A................ Gas............... 54.1 44,800 103.2 97.9 77.2 0.577 0.596
27.............................. N/A................ Oil............... 30.1 104,000 112.5 127.4 89.4 0.605 0.641
28.............................. N/A................ Oil............... 29.8 105,100 104.8 111.6 71.4 0.518 0.528
29.............................. N/A................ Electric.......... 25.7 15,100 41.4 39.7 98.0 0.949 0.903
30.............................. N/A................ Electric.......... 25.8 15,400 42.9 42.9 98.0 0.936 0.891
31.............................. N/A................ Electric.......... 35.0 15,400 55.5 52.3 98.0 0.941 0.937
32.............................. N/A................ Electric.......... 25.1 16,300 40.8 46.2 98.0 0.944 0.902
33.............................. N/A................ Electric.......... 36.2 15,200 53.2 50.0 98.0 0.940 0.906
34.............................. N/A................ Electric.......... 45.1 15,300 56.5 65.3 98.0 0.930 0.909
35.............................. N/A................ Electric.......... 46.0 14,800 66.8 59.9 98.0 0.917 0.932
36.............................. N/A................ Electric.......... 46.0 15,400 61.1 59.8 98.0 0.948 0.946
37.............................. N/A................ Electric.......... 26.7 13,000 38.7 43.2 98.0 0.912 0.902
38.............................. N/A................ Electric.......... 49.7 18,100 68.6 73.3 98.0 0.914 0.942
39.............................. N/A................ Electric.......... 35.8 15,000 53.8 48.5 98.0 0.927 0.868
40.............................. N/A................ Electric.......... 45.3 15,400 62.7 64.2 98.0 0.922 0.931
41.............................. N/A................ Electric.......... 45.2 15,000 66.1 68.7 98.0 0.949 0.919
42.............................. N/A................ Electric.......... 36.0 14,900 53.8 54.8 98.0 0.917 0.941
43.............................. N/A................ Electric.......... 44.8 14,800 64.9 59.4 98.0 0.958 0.926
44.............................. N/A................ Electric.......... 54.5 15,300 80.7 77.2 98.0 0.959 0.952
45.............................. N/A................ Electric.......... 45.0 15,200 63.7 56.8 98.0 0.937 0.904
46.............................. N/A................ Electric.......... 44.7 15,600 60.7 64.8 98.0 0.915 0.901
47.............................. N/A................ Electric.......... 35.9 15,400 52.4 51.9 98.0 0.932 0.922
48.............................. N/A................ Tabletop.......... 35.0 15,200 52.9 48.0 98.0 0.877 0.805
49.............................. N/A................ Tabletop.......... 25.0 15,400 37.5 45.3 98.0 0.905 0.859
50.............................. N/A................ Heat Pump......... 45.4 15,400 64.5 56.1 282.9 2.486 1.948
51.............................. N/A................ Heat Pump......... 45.5 15,000 57.3 58.9 270.3 2.270 2.572
52.............................. N/A................ Heat Pump......... 45.1 11,100 59.1 48.7 264.7 2.260 2.071
53.............................. N/A................ Heat Pump......... 58.8 15,300 71.5 68.6 296.9 2.280 2.496
54.............................. N/A................ Heat Pump......... 77.5 15,700 90.5 87.1 288.2 2.270 2.642
55.............................. N/A................ Heat Pump......... 80.8 1,800 57.0 58.0 288.0 2.330 2.540
56.............................. 1-1................ Gas............... 45.7 39,300 91.6 86.9 91.0 0.789 0.806
57.............................. 1-2................ Gas............... 47.9 40,400 89.5 77.3 80.3 0.682 0.704
58.............................. CGS-11............. Gas............... 47.5 40,600 87.5 78.8 83.5 0.697 0.729
59.............................. 1-6................ Gas............... 39.0 39,900 65.2 75.6 77.6 0.600 0.653
60.............................. 1-11............... Gas............... 28.8 29,600 55.4 52.8 80.2 0.636 0.597
61.............................. 1-34............... Gas............... 38.0 39,900 68.5 69.5 82.3 0.649 0.595
62.............................. 1-41............... Gas............... 38.2 38,500 70.0 75.9 85.7 0.719 0.750
63.............................. CGS-14............. Gas............... 48.5 40,200 94.9 89.5 82.9 0.625 0.649
64.............................. CGS-19............. Gas............... 27.9 35,400 66.8 67.9 79.9 0.626 0.597
65.............................. CGS-23............. Gas............... 49.3 39,500 89.2 70.0 77.1 0.587 0.560
66.............................. CGS-26............. Gas............... 28.7 30,600 52.5 51.9 77.4 0.612 0.578
67.............................. CGS-32............. Gas............... 38.3 37,400 74.4 70.6 78.7 0.645 0.651
68.............................. CGS-36............. Gas............... 38.6 34,700 74.9 68.0 79.5 0.624 0.574
69.............................. CGS-37............. Gas............... 39.0 38,600 71.3 62.5 81.0 0.622 0.577
70.............................. CGS-38............. Gas............... 28.7 30,600 55.1 59.6 78.8 0.625 0.596
71.............................. CGS-4.............. Gas............... 38.7 40,100 64.2 78.8 79.1 0.602 0.637
72.............................. CGS-6.............. Gas............... 47.4 50,500 84.9 115.0 78.8 0.580 0.611
73.............................. CGS-8.............. Gas............... 48.3 37,600 84.1 78.5 79.5 0.675 0.711
74.............................. 1-9................ Gas............... 28.2 59,100 93.0 97.9 80.3 0.688 0.718
75.............................. 1-4................ Gas............... 47.9 39,200 88.4 80.7 79.7 0.605 0.656
76.............................. 1-7................ Gas............... 47.9 35,300 79.5 69.6 81.8 0.608 0.580
77.............................. 1-8................ Gas............... 47.9 40,200 78.0 70.8 79.0 0.596 0.593
78.............................. 1-12............... Gas............... 38.2 37,800 75.0 71.5 79.4 0.632 0.558
79.............................. 1-13............... Gas............... 48.0 37,700 94.7 87.2 77.6 0.597 0.613
80.............................. 1-14............... Gas............... 47.6 37,700 86.3 81.7 75.9 0.575 0.611
81.............................. 1-15............... Gas............... 28.0 31,400 57.1 50.6 83.5 0.648 0.598
82.............................. 1-17............... Gas............... 47.8 37,900 87.4 81.7 80.8 0.592 0.622
83.............................. 1-18............... Gas............... 38.9 37,400 75.4 73.6 81.8 0.633 0.588
[[Page 59763]]
84.............................. 1-30............... Gas............... 47.8 40,000 83.0 73.0 79.0 0.610 0.580
85.............................. 1-33............... Gas............... 48.0 40,000 83.5 67.0 79.0 0.610 0.640
86.............................. CGS-1.............. Gas............... 37.8 39,300 67.7 83.8 78.8 0.611 0.654
87.............................. CGS-13............. Gas............... 47.9 36,300 75.6 84.4 78.3 0.588 0.644
88.............................. CGS-15............. Gas............... 54.9 49,600 100.1 89.3 83.5 0.618 0.646
89.............................. CGS-17............. Gas............... 28.8 29,600 51.8 48.2 81.6 0.679 0.603
90.............................. CGS-18............. Gas............... 38.3 33,400 56.1 50.7 82.6 0.633 0.535
91.............................. CGS-2.............. Gas............... 47.7 40,300 87.2 80.8 77.7 0.605 0.614
92.............................. CGS-21............. Gas............... 28.7 36,000 67.8 65.1 85.0 0.657 0.620
93.............................. CGS-22............. Gas............... 47.8 39,600 78.2 71.8 80.7 0.615 0.557
94.............................. CGS-24............. Gas............... 38.8 34,500 59.9 59.9 77.4 0.606 0.588
95.............................. CGS-25............. Gas............... 47.6 40,400 84.3 74.6 77.0 0.585 0.556
96.............................. CGS-3.............. Gas............... 47.6 40,800 83.1 75.9 83.0 0.634 0.669
97.............................. CGS-30............. Gas............... 28.7 32,100 63.0 55.0 79.7 0.623 0.607
98.............................. CGS-33............. Gas............... 26.6 31,900 52.8 57.8 81.2 0.647 0.623
99.............................. CGS-34............. Gas............... 28.4 29,900 52.3 60.4 83.7 0.630 0.596
100............................. CGS-39............. Gas............... 38.3 35,500 76.7 72.0 79.1 0.613 0.552
101............................. CGS-40............. Gas............... 38.4 29,400 59.0 53.7 77.3 0.596 0.556
102............................. CGS-41............. Gas............... 38.3 37,400 73.7 68.6 81.4 0.634 0.620
103............................. CGS-5.............. Gas............... 48.5 40,100 89.2 82.3 80.5 0.619 0.652
104............................. CGS-7.............. Gas............... 46.1 64,500 103.3 130.2 83.9 0.601 0.646
105............................. 2-1................ Gas............... 28.6 32,000 81.1 67.7 82.5 0.653 0.621
106............................. 2-3................ Gas............... 45.7 64,900 100.0 113.0 82.5 0.624 0.654
107............................. 1-5, 10............ Gas............... 38.4 39,500 65.7 64.9 79.1 0.602 0.571
108............................. 1-35............... Gas............... 46.0 60,000 100.0 113.0 82.5 0.624 0.654
109............................. 1-36............... Gas............... 38.1 39,300 71.8 68.6 81.2 0.688 0.633
110............................. 1-43............... Gas............... 38.1 39,300 69.3 68.6 79.8 0.675 0.646
111............................. CGS-12............. Gas............... 49.7 39,400 90.6 81.5 81.6 0.699 0.713
112............................. CGS-31............. Gas............... 38.3 39,700 70.8 66.0 78.0 0.651 0.626
113............................. CGS-35............. Gas............... 38.2 40,600 69.4 67.3 80.5 0.691 0.662
114............................. 2-2................ Gas............... 48.2 39,800 83.6 81.3 77.5 0.652 0.689
115............................. 1-3................ Gas............... 48.1 41,200 87.9 80.1 75.2 0.640 0.685
116............................. 1-37............... Gas............... 48.1 39,400 86.5 82.9 80.0 0.666 0.646
117............................. CGS-10............. Gas............... 38.1 37,800 71.7 78.5 82.9 0.697 0.725
118............................. CGS-16............. Gas............... 47.9 65,700 112.5 114.4 78.3 0.642 0.693
119............................. CGS-9.............. Gas............... 48.6 39,800 92.5 90.7 81.6 0.689 0.704
120............................. 1-22............... Gas............... 39.1 40,100 69.4 87.9 79.3 0.667 0.699
121............................. 1-51............... Gas............... 38.4 38,100 71.2 65.1 79.5 0.614 0.576
122............................. 1-19............... Gas............... 38.2 40,700 77.2 65.8 80.0 0.680 0.658
123............................. 1-21............... Gas............... 48.1 40,400 87.5 82.0 76.6 0.606 0.639
124............................. 1-25............... Gas............... 48.2 39,500 86.6 76.5 79.2 0.590 0.636
125............................. 1-50............... Gas............... 48.1 39,700 91.7 78.6 80.9 0.612 0.636
126............................. 1-47............... Gas............... 38.1 39,600 68.6 77.4 79.7 0.679 0.689
127............................. 1-48............... Gas............... 47.5 61,400 112.0 104.9 82.1 0.683 0.690
128............................. 1-49............... Gas............... 47.5 39,500 85.2 75.9 81.3 0.661 0.674
129............................. 1-20............... Gas............... 47.9 49,700 92.4 86.5 81.7 0.673 0.676
130............................. 1-52............... Gas............... 47.9 44,100 86.9 79.7 81.2 0.682 0.691
131............................. 1-16............... Gas............... 36.8 36,000 67.3 61.6 80.9 0.615 0.592
132............................. 1-44............... Gas............... 48.6 39,200 94.8 91.6 77.4 0.625 0.613
133............................. 1-27, 28, 29....... Gas............... 39.0 35,900 62.6 61.1 79.4 0.625 0.602
134............................. 1-26............... Gas............... 48.1 38,200 83.5 73.9 82.7 0.634 0.592
135............................. 1-45............... Gas............... 38.0 39,300 74.4 75.1 78.3 0.623 0.647
136............................. CGS-20............. Gas............... 37.8 39,900 75.0 68.4 78.0 0.575 0.529
137............................. CGS-27............. Gas............... 28.9 30,500 57.0 67.7 79.3 0.628 0.597
138............................. CGS-28............. Gas............... 38.3 40,700 72.9 66.9 79.3 0.578 0.529
139............................. CGS-29............. Gas............... 39.4 40,800 72.0 73.5 78.3 0.602 0.580
140............................. 1-40............... Gas............... 38.1 40,700 71.8 68.8 77.1 0.610 0.648
141............................. 1-42............... Gas............... 48.3 39,800 86.0 85.8 80.9 0.673 0.715
142............................. 1-46............... Gas............... 38.3 39,200 71.8 68.1 79.1 0.660 0.633
143............................. 1-23............... Gas............... 38.3 41,600 68.2 84.7 82.6 0.677 0.699
144............................. 1-31............... Gas............... 47.9 42,000 68.0 85.0 82.0 0.680 0.700
145............................. 1-38............... Gas............... 37.8 39,200 87.2 66.5 80.2 0.682 0.560
146............................. 1-39............... Gas............... 46.1 50,000 97.4 92.6 81.8 0.669 0.688
147............................. 1-24, 32........... Gas............... 48.1 42,100 80.2 74.0 87.2 0.710 0.682
148............................. 1-68............... Electric.......... 36.1 15,400 53.6 51.2 98.0 0.961 0.942
149............................. CES-11............. Electric.......... 28.6 15,400 42.1 45.9 98.0 0.947 0.897
150............................. CES-12............. Electric.......... 38.4 15,400 49.7 57.4 98.0 0.944 0.922
151............................. CES-13............. Electric.......... 49.8 15,400 63.6 63.3 98.0 0.954 0.911
152............................. CES-14............. Electric.......... 48.6 15,400 59.4 54.3 98.0 0.923 0.920
[[Page 59764]]
153............................. CES-2.............. Electric.......... 25.8 15,400 41.1 38.6 98.0 0.937 0.897
154............................. CES-3.............. Electric.......... 25.6 15,400 43.7 41.4 98.0 0.911 0.890
155............................. CES-4.............. Electric.......... 34.7 15,400 52.5 57.3 98.0 0.935 0.938
156............................. CES-5.............. Electric.......... 27.7 15,400 46.4 49.1 98.0 0.940 0.898
157............................. CES-6.............. Electric.......... 54.7 15,400 80.5 66.4 98.0 0.933 0.933
158............................. CES-7.............. Electric.......... 45.2 15,400 66.4 64.2 98.0 0.939 0.912
159............................. CES-8.............. Electric.......... 45.2 15,400 63.7 60.7 98.0 0.930 0.910
160............................. CES-9.............. Electric.......... 36.1 15,400 54.2 51.5 98.0 0.914 0.888
161............................. 2-4................ Electric.......... 39.0 15,400 59.0 55.0 98.0 0.950 0.920
162............................. 2-7................ Electric.......... 40.6 15,400 64.9 59.4 98.0 0.960 0.926
163............................. 2-8................ Electric.......... 27.3 15,400 45.3 36.5 98.0 0.962 0.878
164............................. 1-64............... Electric.......... 36.3 15,400 55.0 52.0 98.0 0.950 0.950
165............................. 1-65............... Electric.......... 45.7 15,400 58.0 61.0 98.0 0.940 0.930
166............................. 1-66............... Electric.......... 27.1 15,400 48.0 48.0 98.0 0.930 0.870
167............................. 1-53............... Electric.......... 45.5 15,400 64.3 60.1 98.0 0.939 0.919
168............................. 1-54............... Electric.......... 36.4 15,400 53.9 55.6 98.0 0.932 0.929
169............................. 1-56............... Electric.......... 27.4 15,400 47.7 42.1 98.0 0.943 0.911
170............................. 1-57............... Electric.......... 36.4 15,400 57.5 51.3 98.0 0.941 0.915
171............................. 1-58............... Electric.......... 54.8 15,400 71.0 61.1 98.0 0.936 0.907
172............................. 1-59............... Electric.......... 36.2 15,400 59.1 57.0 98.0 0.941 0.931
173............................. 1-69............... Electric.......... 45.4 15,400 59.3 58.3 98.0 0.947 0.922
174............................. 1-60, 61, 62....... Electric.......... 48.0 15,400 65.3 61.0 98.0 0.940 0.910
175............................. 1-55............... Tabletop.......... 36.0 15,400 45.6 58.3 98.0 0.873 0.873
176............................. 1-70............... Heat Pump......... 45.4 15,700 64.5 61.1 289.0 2.450 2.470
177............................. CES-1.............. Heat Pump......... 81.8 15,400 98.4 94.6 304.8 2.617 2.439
178............................. CES-10............. Heat Pump......... 45.6 15,700 69.3 64.1 369.5 3.278 3.270
179............................. CES-15............. Heat Pump......... 73.3 16,000 74.9 78.4 249.3 2.297 2.424
180............................. CES-16............. Heat Pump......... 107.9 16,000 101.7 100.1 214.0 1.971 2.137
181............................. CES-17............. Heat Pump......... 58.7 16,000 71.3 52.3 246.4 2.291 2.219
182............................. 1-71, 72........... Heat Pump......... 45.5 15,700 69.2 66.1 366.7 3.230 3.140
183............................. 1-76............... Heat Pump......... 75.5 15,700 96.0 89.6 386.5 3.310 3.330
184............................. 1-63, 67........... Heat Pump......... 77.5 15,400 81.8 74.8 262.1 2.242 2.270
185............................. 1-73, 74, 75....... Heat Pump......... 75.5 15,700 95.7 89.4 368.1 3.207 3.186
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table III.27--Consumer Storage Water Heater Attributes
--------------------------------------------------------------------------------------------------------------------------------------------------------
CS No. NOX Emission level Condensing Vent type Short or tall Standing pilot
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.................................. Low................... Yes................... Power................ Short................ No.
2.................................. Low................... Yes................... Power................ Tall................. No.
3.................................. Low................... No.................... Atmospheric.......... Short................ No.
4.................................. Low................... No.................... Atmospheric.......... Short................ Yes.
5.................................. Low................... No.................... Atmospheric.......... Short................ Yes.
6.................................. Low................... No.................... Atmospheric.......... Tall................. No.
7.................................. Low................... No.................... Atmospheric.......... Tall................. No.
8.................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
9.................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
10................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
11................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
12................................. Low................... No.................... Power................ Short................ No.
13................................. Low................... No.................... Power................ Short................ No.
14................................. Low................... No.................... Power................ Tall................. No.
15................................. Low................... No.................... Power................ Tall................. No.
16................................. Low................... No.................... Power................ Tall................. No.
17................................. Low................... No.................... Power................ Tall................. No.
18................................. Standard.............. No.................... Atmospheric.......... Short................ Yes.
19................................. Standard.............. No.................... Atmospheric.......... Tall................. Yes.
20................................. Ultra-Low............. No.................... Atmospheric.......... Short................ Yes.
21................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
22................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
23................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
24................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
25................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
26................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
27................................. N/A................... N/A................... N/A.................. Tall................. No.
28................................. N/A................... N/A................... N/A.................. Tall................. No.
29................................. N/A................... N/A................... N/A.................. Short................ N/A.
30................................. N/A................... N/A................... N/A.................. Short................ N/A.
[[Page 59765]]
31................................. N/A................... N/A................... N/A.................. Short................ N/A.
32................................. N/A................... N/A................... N/A.................. Short................ N/A.
33................................. N/A................... N/A................... N/A.................. Short................ N/A.
34................................. N/A................... N/A................... N/A.................. Short................ N/A.
35................................. N/A................... N/A................... N/A.................. Short................ N/A.
36................................. N/A................... N/A................... N/A.................. Short................ N/A.
37................................. N/A................... N/A................... N/A.................. Tall................. N/A.
38................................. N/A................... N/A................... N/A.................. Tall................. N/A.
39................................. N/A................... N/A................... N/A.................. Tall................. N/A.
40................................. N/A................... N/A................... N/A.................. Tall................. N/A.
41................................. N/A................... N/A................... N/A.................. Tall................. N/A.
42................................. N/A................... N/A................... N/A.................. Tall................. N/A.
43................................. N/A................... N/A................... N/A.................. Tall................. N/A.
44................................. N/A................... N/A................... N/A.................. Tall................. N/A.
45................................. N/A................... N/A................... N/A.................. Tall................. N/A.
46................................. N/A................... N/A................... N/A.................. Tall................. N/A.
47................................. N/A................... N/A................... N/A.................. Tall................. N/A.
48................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
49................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
50................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
51................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
52................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
53................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
54................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
55................................. N/A................... N/A................... N/A.................. N/A.................. N/A.
56................................. Low................... Yes................... Power................ Tall................. No.
57................................. Low................... No.................... Atmospheric.......... Short................ No.
58................................. Low................... No.................... Atmospheric.......... Short................ No.
59................................. Low................... No.................... Atmospheric.......... Short................ Yes.
60................................. Low................... No.................... Atmospheric.......... Short................ Yes.
61................................. Low................... No.................... Atmospheric.......... Short................ Yes.
62................................. Low................... No.................... Atmospheric.......... Short................ Yes.
63................................. Low................... No.................... Atmospheric.......... Short................ Yes.
64................................. Low................... No.................... Atmospheric.......... Short................ Yes.
65................................. Low................... No.................... Atmospheric.......... Short................ Yes.
66................................. Low................... No.................... Atmospheric.......... Short................ Yes.
67................................. Low................... No.................... Atmospheric.......... Short................ Yes.
68................................. Low................... No.................... Atmospheric.......... Short................ Yes.
69................................. Low................... No.................... Atmospheric.......... Short................ Yes.
70................................. Low................... No.................... Atmospheric.......... Short................ Yes.
71................................. Low................... No.................... Atmospheric.......... Short................ Yes.
72................................. Low................... No.................... Atmospheric.......... Short................ Yes.
73................................. Low................... No.................... Atmospheric.......... Short................ Yes.
74................................. Low................... No.................... Atmospheric.......... Tall................. No.
75................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
76................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
77................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
78................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
79................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
80................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
81................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
82................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
83................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
84................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
85................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
86................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
87................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
88................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
89................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
90................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
91................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
92................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
93................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
94................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
95................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
96................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
97................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
98................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
99................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
100................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
101................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
102................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
[[Page 59766]]
103................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
104................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
105................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
106................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
107................................ Low................... No.................... Atmospheric.......... Tall................. Yes.
108................................ Low................... No.................... Not Specified........ Not Specified........ Not Specified.
109................................ Low................... No.................... Power................ Short................ No.
110................................ Low................... No.................... Power................ Short................ No.
111................................ Low................... No.................... Power................ Short................ No.
112................................ Low................... No.................... Power................ Short................ No.
113................................ Low................... No.................... Power................ Short................ No.
114................................ Low................... No.................... Power................ Short................ No.
115................................ Low................... No.................... Power................ Tall................. No.
116................................ Low................... No.................... Power................ Tall................. No.
117................................ Low................... No.................... Power................ Tall................. No.
118................................ Low................... No.................... Power................ Tall................. No.
119................................ Low................... No.................... Power................ Tall................. No.
120................................ Standard.............. No.................... Atmospheric.......... Short................ No.
121................................ Standard.............. No.................... Atmospheric.......... Short................ Yes.
122................................ Standard.............. No.................... Atmospheric.......... Tall................. No.
123................................ Standard.............. No.................... Atmospheric.......... Tall................. Yes.
124................................ Standard.............. No.................... Atmospheric.......... Tall................. Yes.
125................................ Standard.............. No.................... Atmospheric.......... Tall................. Yes.
126................................ Standard.............. No.................... Power................ Short................ No.
127................................ Standard.............. No.................... Power................ Short................ No.
128................................ Standard.............. No.................... Power................ Short................ No.
129................................ Standard.............. No.................... Power................ Tall................. No.
130................................ Standard.............. No.................... Power................ Tall................. No.
131................................ Ultra-Low............. No.................... Atmospheric.......... Short................ Yes.
132................................ Ultra-Low............. No.................... Atmospheric.......... Short................ Yes.
133................................ Ultra-Low............. No.................... Atmospheric.......... Short................ Yes.
134................................ Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
135................................ Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
136................................ Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
137................................ Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
138................................ Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
139................................ Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
140................................ Ultra-Low............. No.................... Power................ Short................ No.
141................................ Ultra-Low............. No.................... Power................ Short................ No.
142................................ Ultra-Low............. No.................... Power................ Short................ No.
143................................ Ultra-Low............. No.................... Power................ Tall................. No.
144................................ Ultra-Low............. No.................... Power................ Tall................. No.
145................................ Ultra-Low............. No.................... Power................ Tall................. No.
146................................ Ultra-Low............. No.................... Power................ Tall................. No.
147................................ Ultra-Low............. No.................... Power................ Tall................. No.
148................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
149................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
150................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
151................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
152................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
153................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
154................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
155................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
156................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
157................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
158................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
159................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
160................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
161................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
162................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
163................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
164................................ N/A................... N/A................... N/A.................. Short................ N/A.
165................................ N/A................... N/A................... N/A.................. Short................ N/A.
166................................ N/A................... N/A................... N/A.................. Short................ N/A.
167................................ N/A................... N/A................... N/A.................. Tall................. N/A.
168................................ N/A................... N/A................... N/A.................. Tall................. N/A.
169................................ N/A................... N/A................... N/A.................. Tall................. N/A.
170................................ N/A................... N/A................... N/A.................. Tall................. N/A.
171................................ N/A................... N/A................... N/A.................. Tall................. N/A.
172................................ N/A................... N/A................... N/A.................. Tall................. N/A.
173................................ N/A................... N/A................... N/A.................. Tall................. N/A.
174................................ N/A................... N/A................... N/A.................. Tall................. N/A.
[[Page 59767]]
175................................ N/A................... N/A................... N/A.................. Short................ N/A.
176................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
177................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
178................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
179................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
180................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
181................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
182................................ N/A................... N/A................... N/A.................. Not Specified........ N/A.
183................................ N/A................... N/A................... N/A.................. Tall................. N/A.
184................................ N/A................... N/A................... N/A.................. Tall................. N/A.
185................................ N/A................... N/A................... N/A.................. Tall................. N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
ii. Conversion Factor Results
For consumer storage water heaters, DOE is proposing to use the
regression method described in section III.C.5 to predict first-hour
ratings (FHRs) under the UEF test procedure to be used in the
conversion to UEF since no ``analytical approach'' has been developed.
Of the factors considered, DOE found that the first-hour rating
determined under the EF test procedure was the best overall predictor
of the new first-hour rating. These findings were based on the RMSDs
between predictions and measured values. The resulting equations, which
are proposed for determining the new FHR of consumer storage water
heaters, are presented in Table III.28.
Table III.28--Proposed Consumer Storage Water Heater First-Hour Rating
Conversion Factor Equations
------------------------------------------------------------------------
Distinguishing
Product class criteria Conversion factor
------------------------------------------------------------------------
Consumer Gas-fired Water Heater. Non-Condensing, New FHR = 7.9592 +
Standard or Low 0.8752 x FHRP.
NOX. New FHR = 25.0680
Non-Condensing, + 0.6535 x FHRP.
Ultra-Low NOX. New FHR = 1.0570 x
Condensing........ FHRP.
Consumer Oil-fired Water Heater. N/A............... New FHR = 1.1012 x
FHRP.
Consumer Electric Water Heater.. Electric New FHR = 9.2827 +
Resistance. 0.8092 x FHRP.
Tabletop.......... New FHR = 41.5127
Heat Pump......... + 0.1989 x FHRP.
New FHR = -4.2705
+ 0.9947 x FHRP.
------------------------------------------------------------------------
New FHR is the predicted first-hour rating that would result under
the UEF test method and is used for conversion to UEF; FHRP
is the first-hour rating determined under the EF test procedure, 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 (condensing gas-fired and oil-fired) the available data
were too limited to produce reliable regressions for the full set of
parameters. To constrain the regression so as to generate more reliable
predictions for those smaller sets of data, the intercepts of the
regressions were assigned a value of zero, meaning that a water heater
with an FHRP of zero would also have a New FHR of zero. This
assignment is reasonable because if a hypothetical water heater were
not able to deliver any water under the EF test procedure, it also
would not be able to deliver water under the UEF test procedure.
In response to the first-hour rating mathematical conversion
developed in the NOPR, AHRI argued that the results are often
inconsistent and show no trend, particularly for the consumer gas-fired
storage product class in the medium and high draw patterns. (AHRI, No.
13 at p. 2) Bradford White commented that its testing showed that the
FHR for most models went down with the change in test procedure, some
of which were affected more than others. (Bradford White, No. 14 at p.
2) NEEA stated that the conversion factors that convert prior FHR
ratings to new FHR ratings produce unacceptably large deviations from
the measured FHR ratings for a significant majority of the water
heaters tested. Further, NEEA commented that these large variations
caused 9 of 43 water heaters tested to fall into a different draw bin
using the conversion as compared to the tested rating, and it
recommended that given the critical nature of the FHR in selecting the
proper draw pattern, DOE should not attempt to mathematically derive
FHR and maximum GPM ratings, but should instead require them to be
measured in accordance with the new test procedures. (NEEA, No. 15 at
pp. 5-6)
In response, DOE notes that it explored several possible
conversions for developing the FHR conversion. The best trend was
observed based on a regression as a function of first-hour rating. The
average RMSD value resulting from this approach (7.56 gallons) is the
lowest RMSD observed in the FHR analysis, and DOE is unaware of any
approaches that would result in improved accuracy. Further, as
discussed above in section III.E.2, the predicted UEF values (which are
based in part on the predicted FHR values due to the dependence of draw
pattern on FHR) are reasonable because they are less than the
variability currently allowed in DOE's regulations that manufacturers
are required to use and rate their basic models. DOE seeks further
comment regarding other methods for predicting FHR that could result in
lower RMSDs. In the absence of any known alternatives, DOE plans to
continue the use of this methodology, but seeks further comment on
other approaches for converting first-hour ratings.
After determining the converted first-hour rating, the next step in
the conversion process 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 using 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 1
of the
[[Page 59768]]
uniform efficiency descriptor test procedure. 10 CFR 430, Subpart B,
Appendix E, section 5.4.1. 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.4.c for all consumer water heater types.
Alternatively, DOE investigated the step regression approach described
in section III.C.2 to convert EF to UEF. As described in the April 2015
NOPR, 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 a conversion with the lowest RMSD observed. 80 FR 20116, 20132
(April 14, 2015). 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 in Table
III.30. In light of the additional data compiled for the SNOPR, the
RMSD for the non-heat pump storage water heater classes is 0.018 when
using a combined WHAM-regression model, and as noted, this is the
lowest RMSD observed. DOE, therefore, continues to propose the use of
the combined WHAM-regression approach to calculate the conversion
factor for all types of consumer storage water heaters except 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. The resulting equations for
determining the UEF of consumer storage water heaters are shown in
Table III.29.
For heat pump water heaters, DOE determined in the April 2015 NOPR
that, although the relevant data can be obtained through testing (and
for the units tested by DOE were obtained), the data are not available
within the certification databases to compute the WHAM estimate for
heat pump water heaters on the market; therefore, a linear regression
equation was developed in which the UEF is estimated solely based on
the EF. 80 FR 20116, 20132 (April 14, 2015). DOE received no comments
submitting data on this point or identifying sources from which DOE
could obtain such data. In this SNOPR, DOE proposes that manufacturers
should apply the conversions to their test data directly, and then the
converted test values will be used to rate the water heater model in
accordance with the certification provisions found in 10 CFR 429.17.
Because both DOE's data from its testing and the test data submitted by
AHRI include all of the necessary information to estimate the
efficiency using the WHAM equation, WHAM and WHAM-Regression
conversions can be derived based on the tested values. Under either of
these approaches, manufacturers would use data from EF tests that is
generally not publicly-available (e.g., the recovery efficiency of the
heat pump) along with a WHAM-based equation to convert to the UEF
metric. The WHAM, regression (modified from the NOPR proposal as
discussed immediately below), and WHAM-Regression conversion approaches
result in RMSD values of 0.219, 0.194, and 0.197, respectively. The
regression approach was modified as discussed below and has the lowest
RMSD value, and, therefore, DOE continues to propose to use the
regression conversion approach for converting to UEF for HPWH.
GE stated that the proposed conversion for HPWH is inaccurate, and
suggested including drawn volume as an independent variable in the
regression analysis to improve the conversion for high-EF heat pump
water heaters. (GE, No. 12 at p. 1) GE also provided an equation which
related EF and drawn volume to UEF. (GE, No. 12 at p. 4) DOE considered
these suggestions and agrees that the inclusion of drawn volume as a
regression variable would help improve the conversion factor, so DOE
has updated the equation appropriately. The GE equation and the new
DOE-derived conversion factor results in RMSD values of 0.229 and
0.194, respectively, which is an improvement over the previous
conversion factor's RMSD value for heat pump water heaters, which is
0.438 (recalculated with new test data). 80 FR 20116, 20133 (April 14,
2015). Even after considering the large disparity between EF standards
and the rated EF values for heat pump water heaters, DOE has
nonetheless tentatively concluded that this relatively high RMSD would
not cause a water heater to fail to meet the standards based on UEF.
Furthermore, the disparity between the UEF of heat pump water heaters
and electric resistance water heaters is large enough that consumers
would still be made aware of the significant increase in efficiency
that heat pump water heaters provide over electric resistance water
heaters.
In the equations in Table III.29, UEFWHAM is the
conversion factor calculated using the WHAM analytical model, described
in section III.C.4.c, EF is the measured energy factor, and DV is the
drawn volume in gallons.
Table III.29--Proposed Consumer Storage UEF Conversion Factor Equations
------------------------------------------------------------------------
Distinguishing Conversion factor
Product class criteria *
------------------------------------------------------------------------
Consumer Gas-fired Water Heater. Non-Condensing, New UEF = -0.0002
Standard or Low + 0.9858 x
NOX. UEFWHAM.
Non-Condensing, New UEF = 0.0746 +
Ultra-Low NOX. 0.8653 x UEFWHAM.
Condensing........ New UEF = 0.4242 +
0.4641 x UEFWHAM.
Consumer Oil-fired Water Heater. N/A............... New UEF = -0.0934
+ 1.1144 x
UEFWHAM.
Consumer Electric Water Heater.. Conventional...... New UEF = 0.4774 +
Tabletop.......... 0.4740 x UEFWHAM.
Heat Pump......... New UEF = -0.3305
+ 1.3983 x
UEFWHAM.
New UEF = 0.1513 +
0.8407 x EF +
0.0043 x DV.
------------------------------------------------------------------------
Table III.30--Consumer Storage Water Heater Conversion Factor Results
----------------------------------------------------------------------------------------------------------------
WHAM-
CS No. Tested FHR Regression Tested UEF WHAM UEF Regression Regression
(gal) FHR (gal) UEF UEF
----------------------------------------------------------------------------------------------------------------
1................................. 104.2 78.0 0.802 0.821 0.805 0.805
2................................. 85.0 96.2 0.826 0.865 0.826 0.826
3................................. 80.9 73.2 0.714 0.718 0.685 0.708
4................................. 86.7 93.3 0.634 0.648 0.611 0.638
[[Page 59769]]
5................................. 64.8 70.4 0.600 0.607 0.624 0.599
6................................. 75.7 72.3 0.719 0.732 0.694 0.722
7................................. 63.8 78.1 0.669 0.694 0.702 0.684
8................................. 87.7 91.3 0.635 0.645 0.608 0.635
9................................. 77.8 70.9 0.635 0.640 0.608 0.631
10................................ 64.4 59.6 0.605 0.598 0.618 0.589
11................................ 70.9 73.5 0.570 0.598 0.618 0.590
12................................ 65.1 68.1 0.624 0.649 0.660 0.639
13................................ 74.1 69.4 0.654 0.656 0.668 0.647
14................................ 94.6 92.8 0.718 0.721 0.695 0.711
15................................ 68.1 65.7 0.677 0.679 0.691 0.670
16................................ 81.1 86.9 0.676 0.705 0.669 0.694
17................................ 108.8 102.5 0.680 0.686 0.651 0.676
18................................ 81.1 66.6 0.628 0.643 0.602 0.634
19................................ 87.0 69.4 0.641 0.650 0.611 0.641
20................................ 64.8 69.7 0.598 0.584 0.600 0.580
21................................ 70.6 61.7 0.561 0.586 0.607 0.582
22................................ 88.2 85.2 0.662 0.668 0.622 0.652
23................................ 84.0 86.6 0.640 0.584 0.559 0.580
24................................ 51.5 58.0 0.603 0.623 0.632 0.613
25................................ 83.2 82.5 0.617 0.632 0.594 0.622
26................................ 97.9 92.5 0.596 0.617 0.582 0.609
27................................ 127.4 123.8 0.641 0.659 0.641 0.641
28................................ 111.6 115.4 0.528 0.557 0.528 0.528
29................................ 39.7 42.8 0.903 0.926 0.922 0.916
30................................ 42.9 44.0 0.891 0.905 0.912 0.906
31................................ 52.3 54.2 0.937 0.935 0.917 0.921
32................................ 46.2 42.3 0.902 0.919 0.919 0.913
33................................ 50.0 52.3 0.906 0.912 0.916 0.910
34................................ 65.3 55.0 0.909 0.922 0.908 0.914
35................................ 59.9 63.3 0.932 0.906 0.898 0.907
36................................ 59.8 58.7 0.946 0.943 0.922 0.924
37................................ 43.2 40.6 0.902 0.866 0.894 0.888
38................................ 73.3 64.8 0.942 0.903 0.895 0.906
39................................ 48.5 52.8 0.868 0.891 0.906 0.900
40................................ 64.2 60.0 0.931 0.912 0.902 0.910
41................................ 68.7 62.8 0.919 0.944 0.923 0.925
42................................ 54.8 52.8 0.941 0.906 0.898 0.907
43................................ 59.4 61.8 0.926 0.955 0.930 0.930
44................................ 77.2 74.6 0.952 0.965 0.930 0.935
45................................ 56.8 60.9 0.904 0.930 0.913 0.918
46................................ 64.8 58.4 0.901 0.905 0.897 0.906
47................................ 51.9 51.7 0.922 0.923 0.909 0.915
48................................ 48.0 52.0 0.805 0.812 0.867 0.805
49................................ 45.3 49.0 0.859 0.855 0.888 0.865
50................................ 56.1 59.9 1.948 2.441 2.478 2.494
51................................ 58.9 52.7 2.572 2.215 2.296 2.312
52................................ 48.7 54.5 2.071 2.049 2.214 2.177
53................................ 68.6 66.8 2.496 2.202 2.305 2.301
54................................ 87.1 85.7 2.642 2.401 2.421 2.462
55................................ 58.0 52.4 2.540 2.213 2.347 2.310
56................................ 86.9 96.8 0.806 0.817 0.804 0.803
57................................ 77.3 86.3 0.704 0.710 0.676 0.699
58................................ 78.8 84.5 0.729 0.728 0.690 0.718
59................................ 75.6 65.0 0.653 0.637 0.601 0.628
60................................ 52.8 56.4 0.597 0.615 0.634 0.606
61................................ 69.5 67.9 0.595 0.628 0.646 0.619
62................................ 75.9 69.2 0.750 0.750 0.710 0.739
63................................ 89.5 91.0 0.649 0.667 0.624 0.658
64................................ 67.9 66.4 0.597 0.605 0.625 0.596
65................................ 70.0 86.0 0.560 0.566 0.590 0.557
66................................ 51.9 53.9 0.578 0.592 0.612 0.583
67................................ 70.6 73.1 0.651 0.627 0.642 0.618
68................................ 68.0 73.5 0.574 0.603 0.623 0.594
69................................ 62.5 70.4 0.577 0.600 0.622 0.591
70................................ 59.6 56.2 0.596 0.605 0.624 0.596
71................................ 78.8 64.1 0.637 0.642 0.603 0.632
72................................ 115.0 82.3 0.611 0.622 0.583 0.613
73................................ 78.5 81.6 0.711 0.702 0.670 0.692
74................................ 97.9 89.4 0.718 0.714 0.682 0.704
[[Page 59770]]
75................................ 80.7 85.3 0.656 0.645 0.606 0.636
76................................ 69.6 77.5 0.580 0.584 0.609 0.576
77................................ 70.8 76.2 0.593 0.574 0.598 0.565
78................................ 71.5 73.6 0.558 0.612 0.631 0.603
79................................ 87.2 90.8 0.613 0.635 0.599 0.626
80................................ 81.7 83.5 0.611 0.614 0.579 0.605
81................................ 50.6 57.9 0.598 0.625 0.645 0.616
82................................ 81.7 84.5 0.622 0.636 0.594 0.627
83................................ 73.6 73.9 0.588 0.611 0.632 0.602
84................................ 73.0 80.6 0.580 0.589 0.611 0.580
85................................ 67.0 81.0 0.640 0.589 0.611 0.580
86................................ 83.8 67.2 0.654 0.649 0.611 0.639
87................................ 84.4 74.1 0.644 0.629 0.590 0.620
88................................ 89.3 95.6 0.646 0.662 0.618 0.653
89................................ 48.2 53.3 0.603 0.606 0.674 0.598
90................................ 50.7 57.1 0.535 0.544 0.632 0.536
91................................ 80.8 84.3 0.614 0.642 0.606 0.632
92................................ 65.1 67.3 0.620 0.634 0.653 0.625
93................................ 71.8 76.4 0.557 0.593 0.615 0.584
94................................ 59.9 60.4 0.588 0.586 0.607 0.577
95................................ 74.6 81.7 0.556 0.564 0.588 0.555
96................................ 75.9 80.7 0.669 0.675 0.632 0.665
97................................ 55.0 63.1 0.607 0.602 0.622 0.593
98................................ 57.8 54.2 0.623 0.626 0.644 0.617
99................................ 60.4 53.7 0.596 0.606 0.629 0.597
100............................... 72.0 75.1 0.552 0.592 0.613 0.583
101............................... 53.7 59.6 0.556 0.574 0.598 0.566
102............................... 68.6 72.5 0.620 0.613 0.632 0.604
103............................... 82.3 86.0 0.652 0.658 0.619 0.649
104............................... 130.2 98.4 0.646 0.648 0.602 0.639
105............................... 67.7 78.9 0.621 0.632 0.650 0.623
106............................... 113.0 95.5 0.654 0.666 0.623 0.656
107............................... 64.9 65.5 0.571 0.580 0.603 0.571
108............................... 113.0 95.5 0.654 0.666 0.623 0.656
109............................... 68.6 70.8 0.633 0.672 0.682 0.662
110............................... 68.6 68.6 0.646 0.659 0.670 0.649
111............................... 81.5 87.3 0.713 0.726 0.692 0.715
112............................... 66.0 69.9 0.626 0.634 0.648 0.625
113............................... 67.3 68.7 0.662 0.676 0.684 0.666
114............................... 81.3 81.1 0.689 0.680 0.649 0.670
115............................... 80.1 84.9 0.685 0.666 0.638 0.656
116............................... 82.9 83.7 0.646 0.696 0.662 0.686
117............................... 78.5 70.7 0.725 0.727 0.690 0.716
118............................... 114.4 106.4 0.693 0.673 0.640 0.663
119............................... 90.7 88.9 0.704 0.718 0.683 0.707
120............................... 87.9 68.7 0.699 0.695 0.663 0.685
121............................... 65.1 70.3 0.576 0.593 0.614 0.584
122............................... 65.8 75.5 0.658 0.664 0.674 0.655
123............................... 82.0 84.5 0.639 0.641 0.607 0.631
124............................... 76.5 83.8 0.636 0.632 0.592 0.623
125............................... 78.6 88.2 0.636 0.653 0.612 0.644
126............................... 77.4 68.0 0.689 0.706 0.674 0.696
127............................... 104.9 106.0 0.690 0.714 0.677 0.703
128............................... 75.9 82.5 0.674 0.695 0.657 0.685
129............................... 86.5 88.8 0.676 0.705 0.668 0.695
130............................... 79.7 84.0 0.691 0.711 0.676 0.701
131............................... 61.6 69.0 0.592 0.592 0.610 0.587
132............................... 91.6 87.0 0.613 0.658 0.618 0.644
133............................... 61.1 66.0 0.602 0.605 0.618 0.598
134............................... 73.9 79.6 0.592 0.611 0.625 0.604
135............................... 75.1 73.7 0.647 0.658 0.616 0.644
136............................... 68.4 74.1 0.529 0.552 0.580 0.552
137............................... 67.7 62.3 0.597 0.607 0.620 0.600
138............................... 66.9 72.7 0.529 0.554 0.582 0.554
139............................... 73.5 72.1 0.580 0.581 0.601 0.577
140............................... 68.8 72.0 0.648 0.591 0.607 0.586
141............................... 85.8 81.3 0.715 0.704 0.654 0.683
142............................... 68.1 72.0 0.633 0.643 0.644 0.631
143............................... 84.7 69.6 0.699 0.710 0.657 0.689
144............................... 85.0 69.5 0.700 0.711 0.660 0.690
[[Page 59771]]
145............................... 66.5 82.1 0.560 0.666 0.661 0.651
146............................... 92.6 88.7 0.688 0.702 0.651 0.682
147............................... 74.0 77.4 0.682 0.690 0.682 0.672
148............................... 51.2 52.7 0.942 0.957 0.932 0.931
149............................... 45.9 43.4 0.897 0.924 0.921 0.915
150............................... 57.4 49.5 0.922 0.938 0.919 0.922
151............................... 63.3 60.7 0.911 0.950 0.926 0.927
152............................... 54.3 57.3 0.920 0.914 0.903 0.910
153............................... 38.6 42.5 0.897 0.907 0.913 0.907
154............................... 41.4 44.6 0.890 0.865 0.893 0.887
155............................... 57.3 51.8 0.938 0.927 0.912 0.917
156............................... 49.1 46.8 0.898 0.912 0.916 0.910
157............................... 66.4 74.4 0.933 0.925 0.910 0.916
158............................... 64.2 63.0 0.912 0.932 0.915 0.919
159............................... 60.7 60.8 0.910 0.922 0.908 0.914
160............................... 51.5 53.1 0.888 0.903 0.896 0.905
161............................... 55.0 57.0 0.920 0.945 0.923 0.925
162............................... 59.4 61.8 0.926 0.957 0.931 0.931
163............................... 36.5 45.9 0.878 0.949 0.933 0.927
164............................... 52.0 53.8 0.950 0.945 0.923 0.925
165............................... 61.0 56.2 0.930 0.933 0.916 0.920
166............................... 48.0 48.1 0.870 0.896 0.908 0.902
167............................... 60.1 61.3 0.919 0.932 0.915 0.919
168............................... 55.6 52.9 0.929 0.924 0.909 0.915
169............................... 42.1 47.8 0.911 0.917 0.918 0.912
170............................... 51.3 55.8 0.915 0.934 0.916 0.920
171............................... 61.1 66.7 0.907 0.929 0.913 0.918
172............................... 57.0 57.1 0.931 0.934 0.916 0.920
173............................... 58.3 57.3 0.922 0.941 0.921 0.924
174............................... 61.0 62.1 0.910 0.933 0.916 0.920
175............................... 58.3 50.6 0.873 0.856 0.864 0.867
176............................... 61.1 59.9 2.470 2.394 2.448 2.456
177............................... 94.6 93.6 2.439 2.715 2.713 2.716
178............................... 64.1 64.7 3.270 3.223 3.144 3.127
179............................... 78.4 70.2 2.424 2.344 2.444 2.416
180............................... 100.1 96.9 2.137 2.012 2.170 2.147
181............................... 52.3 66.7 2.219 2.266 2.314 2.353
182............................... 66.1 64.5 3.140 3.173 3.103 3.087
183............................... 89.6 91.2 3.330 3.436 3.295 3.299
184............................... 74.8 77.0 2.270 2.193 2.272 2.293
185............................... 89.4 91.0 3.186 3.316 3.208 3.202
----------------------------------------------------------------------------------------------------------------
In response to the UEF conversion for the NOPR, AHRI commented that
units tested with the very small, low, and medium draw patterns will
likely have UEF values less than EF, while units tested with the high
draw pattern will likely have UEF values greater than EF due to standby
times. (AHRI, No. 13 at p. 6) Were standby time the only factor
affecting the difference between EF and UEF, AHRI's argument would have
some merit. However, in 9 percent of the consumer storage tests, a
pattern opposite from what AHRI suggested was observed. This empirical
observation indicates that AHRI's assumptions are not wholly correct.
AHRI also commented that for most of the electric resistance water
heater samples, the calculated conversion factor using the WHAM-
regression UEF model does not track with the tested UEF (i.e., some
values are higher than the test result, others lower). (AHRI, No. 13 at
p. 5) Further, AHRI stated that for electric resistance models, the
measured UEF is consistently lower than the measured EF, although the
amount of difference varies. AHRI stated that the data for units in the
low-usage bin indicate a very significant miscalculation of the effect
of the UEF test procedure on those models, and that the converted UEF
value in most cases is higher than the measured UEF value, which
suggests that the converted UEF formula is underestimating the effect
of the uniform energy descriptor test procedure. (AHRI, No. 6 at p. 2)
AHRI also pointed out that the measured UEFs for low-input (<10,000
Btu/h) heat pump water heaters were higher than the measured EF, and
for the one higher-input unit, the measured UEF was lower than the
measured EF. However, with one exception, the calculated UEF using the
proposed conversion exhibited the opposite results. (AHRI, No. 13 at p.
5)
Rheem commented that several electric storage water heaters (both
heat pump and non-heat pump) in the medium draw pattern show an
increased UEF rating as compared to EF in DOE's test results. However,
Rheem asserted that since the UEF test method has more standby time
than the EF test method, the resulting UEF would be expected to
decrease, and stated that it has observed a consistent decrease in the
UEF of electric storage water heaters in the medium draw bin, as
compared to the EF rating. (Rheem, No. 11 at pp. 4-5)
With respect to AHRI's observation that the WHAM-regression model
does not perfectly reproduce the UEF measurements of every model, DOE
notes that, as discussed previously, a
[[Page 59772]]
simple conversion formula will not reproduce identically the results
that one would measure by applying the EF and UEF test methods for each
and every unit. Yet DOE's task, as required by the statute, is to
prepare a set of conversion formulas. DOE understands the statute, by
implication, to contemplate that for any given unit, there may be some
difference between the formula output and the comparative EF and UEF
test results.
AHRI's observation that the measured UEF is consistently less than
the measured EF for electric resistance storage water heaters in the
low-draw bin generally still holds for the conversion factor proposed
in this SNOPR, and as stated above, this behavior is expected. Of the
13 low-draw-pattern units for which test data are available for the
SNOPR, the conversion factor predicts a UEF higher than the tested UEF
in 9 cases, equal to the tested UEF in 3 cases, and lower than the
predicted UEF in 1 case. DOE reasons that this result is due to the
large number of medium-draw-pattern units used to derive the conversion
factor. Similarly, the converted UEF for the one high-draw-pattern
electric storage water heater is below the tested UEF value. Because
the regression analysis is conducted across all draw patterns for a
given class, the result may more heavily favor draw patterns with more
data present. DOE believes that proposing a separate conversion for
each draw pattern would eliminate this issue. However, if DOE were to
propose conversions for each draw pattern, the number of UEF conversion
equations would increase from 26 to 104. DOE believes a separate
conversion factor for each draw pattern would add a significant amount
of complexity to the conversion factor that would not be justified by
the slight skew toward draw patterns with more units (and therefore
more test data). DOE also notes that the converted values are not
always higher than the tested values under the conversions proposed in
this SNOPR indicating that this effect does not occur consistently for
all units. Further, Rheem's observation that the consumer electric
storage medium-draw-pattern testing yields UEFs greater than
corresponding EF values for some units appears to occur in both the DOE
and AHRI data sets, suggesting that standby time is not the only
variable to consider when comparing results from the two test
procedures. AHRI's observation about the effect of the input rate on
the difference between measured UEF and EF in the heat pump water
heater tests based on the NOPR data appears not to hold with the
addition of the AHRI test data.
For gas-fired storage water heaters, AHRI commented that in the
medium-usage bin, the measured UEF is consistently lower than the
measured EF, but there is no consistent pattern in the difference
between the measured UEF and the converted UEF. (AHRI, No. 6 at p. 2)
For gas-fired storage water heaters in the high-usage bin, AHRI stated
that the measured UEF is consistently higher than the measured EF, and
there is no consistent relationship between the converted UEF value and
the measured UEF value. (AHRI, No. 6 at p. 2) AHRI and Rheem commented
that, for ultra-low NOX gas-fired water heaters, the
measured UEF for the short models was less than the measured EF and the
measured UEF for the tall models was greater than the measured EF, but
that the calculated UEF using the conversion exhibits the opposite
relationship. AHRI and Rheem suggested the trend requires further test
data for such units. (AHRI, No. 13 at p. 5; Rheem, No. 11 at p. 7)
In general, measured UEF values in the very small, low, or medium
draw patterns will usually be lower than their respective measured EF
values, and measured UEF values in the high draw patterns will usually
be higher than their respective measured EF value. Also, this outcome
(i.e., converted results both higher and lower than the measured
results for a category of water heater) is what one should expect if
the conversion is, overall, a reasonable representation of efficiency.
Therefore, AHRI's comments about the consumer gas-fired storage test
and conversion data for the medium and high draw pattern reflect the
expected result of the conversion.
AHRI and Rheem's comment about the ultra-low NOX short
comparison of measured EF and UEF seems to still hold with the addition
of the AHRI test data; that is, the measured UEF for 4 of the 7 short
models was less than the measured EF, equal to the measured EF for 1
unit, and greater than the measured EF for 2 units. The measured UEF
for the tall models was greater than the measured EF in 8 of the 17
units, and less than the measured EF in the other 9 units. When
examining the converted UEF values, 5 short units have converted UEFs
less than the measured EF and 2 that are greater, while the same
relationship exists in the converted UEF data as was observed in the
measured UEF data for the tall units. Further, deriving separate
conversions for short and tall ultra-low NOX water heaters
decreases the RMSD value by less than 0.0015, which seems like a
negligible improvement when weighed against the added complexity of an
additional conversion factor. DOE also notes that it is not aware of an
industry-accepted consensus for determining whether a water heater is
``tall'' or ``short,'' which makes implementing a conversion based on
this factor difficult.
b. Consumer Instantaneous Water Heaters
i. Test Results
DOE has tested 22 consumer instantaneous water heaters to both the
EF and UEF test procedures, and AHRI has supplied test data for 36
additional units of this water heater type.13 14 Table
III.31 presents the test data used to derive the proposed consumer
instantaneous water heater conversion factors. DOE notes that 1 of the
53 gas-fired instantaneous water heaters that were tested is not rated
to meet the current energy conservation standards (compliance required
April 16, 2015). However, as discussed in section III.E.2.a.i, DOE
believes that these data points are valid for the purpose of
determining the mathematical 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.32 shows the water heater attributes by unit described in section
III.E.1.
---------------------------------------------------------------------------
\13\ The AHRI submitted test data point CIS-5 was not used
because the measured input rate was greater than the maximum
allowable deviation from the rated input rate of 2 percent,
resulting in an invalid test.
\14\ If multiple tests were conducted on either the same unit or
same basic model of a water heater, the results were averaged to
produce the values reported in this SNOPR. In one instance within
the AHRI submitted data for consumer instantaneous water heaters,
three tests were conducted, where two tests were conducted on the
same unit and another test was conducted on a unit of the same basic
model. The two tests of the same unit were averaged and this value
was then averaged with the results of the test of the unit of the
same basic model.
[[Page 59773]]
Table III.31--Consumer Instantaneous Water Heater Test Data
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Input rate Updated max Prior recovery
CI No. AHRI No. Type (Btu/h) Prior max GPM GPM efficiency (%) EF UEF
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1............................................. N/A............................. Gas 142,500 3.0 3.4 80.9 0.801 0.800
2............................................. N/A............................. Gas 190,800 4.2 4.8 81.4 0.813 0.820
3............................................. N/A............................. Gas 120,900 2.7 3.1 82.6 0.828 0.809
4............................................. N/A............................. Gas 141,100 3.1 3.6 81.7 0.812 0.823
5............................................. N/A............................. Gas 175,800 3.7 4.3 84.5 0.838 0.833
6............................................. N/A............................. Gas 178,500 4.1 4.7 83.8 0.838 0.830
7............................................. N/A............................. Gas 199,000 4.6 4.9 86.9 0.872 0.841
8............................................. N/A............................. Gas 179,900 4.0 4.6 80.3 0.803 0.840
9............................................. N/A............................. Gas 180,400 3.9 4.6 85.1 0.852 0.832
10............................................ N/A............................. Gas 199,200 4.3 5.1 75.0 0.743 0.799
11............................................ N/A............................. Gas 151,700 3.4 3.9 85.4 0.853 0.813
12............................................ N/A............................. Gas 199,800 4.8 4.1 93.8 0.932 0.939
13............................................ N/A............................. Gas 197,200 5.2 5.8 96.7 0.966 0.958
14............................................ N/A............................. Gas 154,100 4.0 4.5 91.6 0.913 0.925
15............................................ N/A............................. Gas 201,300 4.9 5.7 88.0 0.851 0.884
16............................................ N/A............................. Gas 117,800 2.5 2.9 77.7 0.776 0.757
17............................................ N/A............................. Gas 148,800 3.3 3.7 82.6 0.823 0.811
18............................................ N/A............................. Electric 33,100 0.9 1.0 101.7 1.018 1.010
19............................................ N/A............................. Electric 7,800 0.2 0.2 101.2 1.013 0.983
20............................................ N/A............................. Electric 19,800 0.5 0.6 102.2 1.020 1.006
21............................................ N/A............................. Electric 26,000 0.7 0.8 102.0 1.019 1.007
22............................................ N/A............................. Electric 31,000 0.8 0.9 101.5 1.017 0.982
23............................................ 1-94............................ Gas 187,800 4.0 4.5 80.2 0.794 0.809
24............................................ 1-92, 93........................ Gas 187,900 4.0 4.4 83.0 0.816 0.815
25............................................ CIS-1........................... Gas 137,700 3.1 3.6 83.6 0.832 0.812
26............................................ CIS-2........................... Gas 198,300 4.3 5.0 85.0 0.845 0.843
27............................................ CIS-3........................... Gas 151,600 3.4 3.9 84.8 0.845 0.806
28............................................ CIS-4........................... Gas 202,100 4.4 5.1 91.7 0.916 0.869
29............................................ CIS-6........................... Gas 148,400 3.2 3.8 83.4 0.836 0.805
30............................................ CIS-9........................... Gas 196,000 4.4 5.0 88.7 0.882 0.869
31............................................ 1-85............................ Gas 202,300 4.4 5.1 86.3 0.864 0.817
32............................................ 1-86............................ Gas 200,400 4.4 5.1 86.3 0.859 0.826
33............................................ 1-87............................ Gas 186,500 4.3 4.8 83.9 0.838 0.816
34............................................ 1-88............................ Gas 195,700 4.3 5.0 80.8 0.809 0.640
35............................................ 1-89............................ Gas 142,900 3.2 3.6 84.6 0.842 0.792
36............................................ 1-90............................ Gas 188,500 4.0 4.6 85.3 0.847 0.824
37............................................ 1-100........................... Gas 197,400 4.3 5.5 83.8 0.826 0.818
38............................................ 1-101........................... Gas 141,800 3.1 3.6 83.1 0.831 0.816
39............................................ 1-77, 83, 84.................... Gas 151,600 3.5 4.0 87.2 0.874 0.851
40............................................ 1-97............................ Gas 198,700 4.8 5.5 98.8 0.975 0.952
41............................................ CIS-7........................... Gas 195,100 5.1 5.6 97.8 0.978 0.922
42............................................ CIS-8........................... Gas 150,100 3.7 4.3 95.3 0.951 0.918
43............................................ 2-9............................. Gas 203,200 4.8 5.5 98.2 0.974 0.943
44............................................ 2-10............................ Gas 177,200 4.4 5.0 96.8 0.951 0.925
45............................................ 2-11............................ Gas 203,500 4.9 5.4 98.1 0.974 0.945
46............................................ 2-12............................ Gas 195,100 4.9 5.6 96.7 0.965 0.922
47............................................ 2-13............................ Gas 150,100 3.7 4.3 95.3 0.951 0.918
48............................................ 1-78............................ Gas 155,000 3.8 4.4 97.4 0.964 0.928
49............................................ 1-79............................ Gas 159,400 4.0 4.5 96.1 0.959 0.921
50............................................ 1-80............................ Gas 176,900 4.3 4.9 96.3 0.947 0.920
51............................................ 1-81............................ Gas 176,700 4.3 4.9 97.9 0.966 0.933
52............................................ 1-82............................ Gas 183,200 4.5 5.2 96.5 0.957 0.919
53............................................ 1-91............................ Gas 120,500 3.1 3.5 94.1 0.937 0.910
54............................................ 1-98............................ Gas 182,100 4.1 5.1 90.8 0.908 0.911
55............................................ 1-99............................ Gas 197,000 5.0 5.0 95.3 0.935 0.924
56............................................ 1-102........................... Gas 122,300 2.9 3.4 91.4 0.915 0.883
57............................................ 1-103........................... Gas 183,000 4.4 4.8 92.1 0.914 0.901
58............................................ 1-104........................... Gas 121,100 2.7 3.2 91.5 0.910 0.864
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table III.32--Consumer Instantaneous Water Heater Attributes
------------------------------------------------------------------------
CI No. NOX emission level Condensing
------------------------------------------------------------------------
1............................... Low............... No.
2............................... Low............... No.
3............................... Low............... No.
4............................... Low............... No.
5............................... Ultra-Low......... No.
6............................... Ultra-Low......... No.
7............................... Ultra-Low......... No.
[[Page 59774]]
8............................... Ultra-Low......... No.
9............................... Ultra-Low......... No.
10.............................. Ultra-Low......... No.
11.............................. Ultra-Low......... No.
12.............................. Ultra-Low......... Yes.
13.............................. Ultra-Low......... Yes.
14.............................. Ultra-Low......... Yes.
15.............................. Ultra-Low......... Yes.
16.............................. Low............... No.
17.............................. Low............... No.
18.............................. N/A............... N/A.
19.............................. N/A............... N/A.
20.............................. N/A............... N/A.
21.............................. N/A............... N/A.
22.............................. N/A............... N/A.
23.............................. Low............... No.
24.............................. Low............... No.
25.............................. Ultra-Low......... No.
26.............................. Ultra-Low......... No.
27.............................. Ultra-Low......... No.
28.............................. Ultra-Low......... No.
29.............................. Ultra-Low......... No.
30.............................. Ultra-Low......... No.
31.............................. Ultra-Low......... No.
32.............................. Ultra-Low......... No.
33.............................. Ultra-Low......... No.
34.............................. Ultra-Low......... No.
35.............................. Ultra-Low......... No.
36.............................. Ultra-Low......... No.
37.............................. Ultra-Low......... No.
38.............................. Ultra-Low......... No.
39.............................. Ultra-Low......... No.
40.............................. Low............... Yes.
41.............................. Ultra-Low......... Yes.
42.............................. Ultra-Low......... Yes.
43.............................. Ultra-Low......... Yes.
44.............................. Ultra-Low......... Yes.
45.............................. Ultra-Low......... Yes.
46.............................. Ultra-Low......... Yes.
47.............................. Ultra-Low......... Yes.
48.............................. Ultra-Low......... Yes.
49.............................. Ultra-Low......... Yes.
50.............................. Ultra-Low......... Yes.
51.............................. Ultra-Low......... Yes.
52.............................. Ultra-Low......... Yes.
53.............................. Ultra-Low......... Yes.
54.............................. Ultra-Low......... Yes.
55.............................. Ultra-Low......... Yes.
56.............................. Ultra-Low......... Yes.
57.............................. Ultra-Low......... Yes.
58.............................. Ultra-Low......... Yes.
------------------------------------------------------------------------
ii. Conversion Factor Results
As stated in section III.C.4.a, DOE developed an analytical model
that DOE proposes to use to convert the prior measured values of
maximum GPM rating for consumer instantaneous water heaters to measured
values under the uniform efficiency descriptor test procedure. DOE also
developed an analytical method to estimate the change in prior measured
values of energy factor under the energy factor test procedure to
measured values of uniform energy factor 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.34. For the maximum GPM
conversions, the RMSD for the three approaches are 0.24, 0.23, and
0.23, respectively. For the UEF conversions, the three approaches have
RMSD of 0.035, 0.028, and 0.027, respectively. DOE has decided to
continue to propose to use the analytical model approach to calculate
the consumer instantaneous maximum GPM conversion factor owing to the
fact that the analytical model approach predicts the resultant data
very closely and that it will broadly apply to those units not tested.
DOE has also decided to continue to propose to use the combined
analytical model-regression approach to convert from EF to UEF since
the RMSDs are the lowest observed, and it has concluded that the use of
the model and regression will capture key effects that may not be
captured with either approach by itself. The resulting conversion
factors for both maximum GPM and UEF are shown in Table III.33. In the
equations in Table III.33, Max GPMP is the maximum GPM based
on the prior DOE test procedure and UEFmodel is the
predicted UEF determined using the analytical model, described in
section III.C.4.c.
Table III.33--Proposed Consumer Instantaneous Conversion Factor
Equations
------------------------------------------------------------------------
Product class Conversion factor
------------------------------------------------------------------------
All Consumer Instantaneous............. New Max GPM = 1.1461 x Max GPMP
Gas-fired Instantaneous................ New UEF = 0.1006 + 0.8622 x
UEFmodel
Electric Instantaneous................. New UEF = 0.9847 x UEFmodel
------------------------------------------------------------------------
Table III.34--Consumer Instantaneous Conversion Factor Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Combined Combined
Tested max Analytical Regression Analytical- Analytical Regression Analytical-
CI No. GPM max GPM max GPM Regression Tested UEF UEF UEF Regression
Max GPM UEF
--------------------------------------------------------------------------------------------------------------------------------------------------------
1............................................... 3.44 3.39 3.49 3.49 0.800 0.804 0.791 0.794
2............................................... 4.81 4.85 4.80 4.80 0.820 0.810 0.802 0.799
3............................................... 3.11 3.09 3.21 3.21 0.809 0.820 0.814 0.808
4............................................... 3.61 3.57 3.64 3.64 0.823 0.811 0.801 0.800
5............................................... 4.31 4.21 4.22 4.22 0.833 0.841 0.823 0.825
6............................................... 4.71 4.68 4.64 4.64 0.830 0.834 0.823 0.820
7............................................... 4.87 5.29 5.18 5.18 0.841 0.865 0.852 0.846
8............................................... 4.59 4.60 4.57 4.57 0.840 0.799 0.793 0.790
9............................................... 4.61 4.50 4.48 4.48 0.832 0.847 0.835 0.831
10.............................................. 5.07 4.93 4.86 4.86 0.799 0.747 0.741 0.745
11.............................................. 3.89 3.85 3.90 3.90 0.813 0.847 0.836 0.831
12.............................................. 4.11 5.50 5.37 5.37 0.939 0.933 0.904 0.905
13.............................................. 5.81 5.94 5.77 5.77 0.958 0.962 0.934 0.930
14.............................................. 4.48 4.56 4.53 4.53 0.925 0.912 0.888 0.887
15.............................................. 5.70 5.62 5.48 5.48 0.884 0.876 0.834 0.856
16.............................................. 2.88 2.85 3.01 3.01 0.757 0.772 0.770 0.766
17.............................................. 3.67 3.73 3.79 3.79 0.811 0.821 0.810 0.808
18.............................................. 0.99 1.00 1.00 1.00 1.010 1.013 1.000 0.997
19.............................................. 0.24 0.24 0.24 0.24 0.983 1.008 0.981 0.993
20.............................................. 0.60 0.59 0.60 0.60 1.006 1.018 1.007 1.003
21.............................................. 0.80 0.78 0.78 0.78 1.007 1.016 1.003 1.001
[[Page 59775]]
22.............................................. 0.93 0.94 0.94 0.94 0.982 1.011 0.997 0.996
23.............................................. 4.50 4.61 4.57 4.57 0.809 0.798 0.785 0.789
24.............................................. 4.40 4.57 4.54 4.54 0.815 0.826 0.804 0.813
25.............................................. 3.56 3.55 3.63 3.63 0.812 0.830 0.818 0.817
26.............................................. 4.95 4.97 4.90 4.90 0.843 0.846 0.829 0.830
27.............................................. 3.94 3.93 3.97 3.97 0.806 0.842 0.829 0.827
28.............................................. 5.10 5.00 4.92 4.92 0.869 0.913 0.890 0.888
29.............................................. 3.80 3.67 3.73 3.73 0.805 0.828 0.821 0.814
30.............................................. 5.05 4.99 4.91 4.91 0.869 0.883 0.861 0.862
31.............................................. 5.14 5.06 4.98 4.98 0.817 0.859 0.845 0.841
32.............................................. 5.07 5.01 4.93 4.93 0.826 0.859 0.841 0.841
33.............................................. 4.84 4.92 4.85 4.85 0.816 0.835 0.823 0.821
34.............................................. 4.96 4.93 4.86 4.86 0.640 0.804 0.798 0.794
35.............................................. 3.63 3.64 3.71 3.71 0.792 0.840 0.827 0.825
36.............................................. 4.57 4.63 4.59 4.59 0.824 0.849 0.831 0.833
37.............................................. 5.52 4.93 4.86 4.86 0.818 0.834 0.813 0.820
38.............................................. 3.62 3.50 3.58 3.58 0.816 0.825 0.817 0.812
39.............................................. 4.00 3.96 4.00 4.00 0.851 0.868 0.855 0.849
40.............................................. 5.54 5.47 5.34 5.34 0.952 0.983 0.941 0.948
41.............................................. 5.60 5.85 5.68 5.68 0.922 0.973 0.944 0.939
42.............................................. 4.30 4.24 4.25 4.25 0.918 0.948 0.921 0.918
43.............................................. 5.50 5.50 5.37 5.37 0.943 0.977 0.941 0.943
44.............................................. 5.00 5.04 4.96 4.96 0.925 0.963 0.921 0.931
45.............................................. 5.40 5.62 5.48 5.48 0.945 0.976 0.941 0.942
46.............................................. 5.60 5.62 5.48 5.48 0.922 0.962 0.933 0.930
47.............................................. 4.30 4.24 4.25 4.25 0.918 0.948 0.921 0.918
48.............................................. 4.36 4.34 4.34 4.34 0.928 0.969 0.932 0.936
49.............................................. 4.52 4.54 4.51 4.51 0.921 0.956 0.928 0.925
50.............................................. 4.94 4.92 4.85 4.85 0.920 0.958 0.917 0.926
51.............................................. 4.92 4.91 4.84 4.84 0.933 0.974 0.934 0.940
52.............................................. 5.18 5.20 5.11 5.11 0.919 0.960 0.926 0.928
53.............................................. 3.50 3.54 3.62 3.62 0.910 0.934 0.909 0.906
54.............................................. 5.10 4.74 4.70 4.70 0.911 0.904 0.884 0.880
55.............................................. 5.05 5.74 5.59 5.59 0.924 0.948 0.907 0.918
56.............................................. 3.37 3.30 3.41 3.41 0.883 0.907 0.890 0.882
57.............................................. 4.80 5.04 4.96 4.96 0.901 0.917 0.889 0.891
58.............................................. 3.20 3.09 3.22 3.22 0.864 0.908 0.885 0.883
--------------------------------------------------------------------------------------------------------------------------------------------------------
In response to the April 2015 NOPR, AHRI commented that for gas-
fired instantaneous water heaters tested by DOE, most condensing units
had measured UEFs that were greater than the EF, but the calculated UEF
using the mathematical conversion for these units in all cases was less
than the tested UEF. (AHRI, No. 13 at p. 6) NEEA commented that the UEF
rating comparison results are so scattered as to strongly suggest that
there are factors, which differ from one water heater to another,
missing from the current analytical approach, or that one or more of
DOE's assumptions or approximations used in the analytical approach are
not valid for every water heater. NEEA suggested that a likely source
of error may be in the methods used to estimate the amount of energy
absorbed by the water heater in any given firing cycle, or the related
estimates of the impact of the time between firing cycles on this
factor. NEEA also commented that the conversion for gas-fired
instantaneous water heaters consistently underrates the UEF of
condensing water heaters and seems unable to predict reliably the
measured UEF of any non-condensing models. (NEEA, No. 15 at p. 6)
In response, DOE notes that the relationship between measured UEF
and EF is not a result of the conversion, but rather how water heaters
are performing when tested to the UEF test procedure. In the set of
data used for this rulemaking, DOE observes that 19 of the 23
condensing units have a measured UEF less than the measured EF. AHRI
and NEEA commented that the conversion for condensing gas-fired
instantaneous water heaters underrates the UEF. DOE notes that with the
new test data and conversion factors, 7 of the condensing units have
converted UEFs greater than the measured, 9 are less than, and 7 are
equal to, after rounding to the second decimal place, suggesting that
the proposed conversion factor contained in this SNOPR is overall, a
more accurate fit to the test data than the conversion factor proposed
in the NOPR. Further, the RMSD values for the NOPR and SNOPR
conversions for the current set of condensing units are 0.063 and
0.017, respectively. These results indicate that the SNOPR conversion
factors are better predictors of actual performance. Regarding NEEA's
statement that the conversion is unable to predict reliably the
measured UEF of non-condensing models, DOE notes that the RMSD value is
0.034 when applied for just non-condensing units, as compared to the
RMSD value of 0.017 when applied to just condensing units, which
indicates that the conversion equation for gas-fired instantaneous
water heaters does fit the non-condensing data points almost as well as
it fits the condensing data points. However, DOE notes that the new
conversion equation for non-condensing gas-fired instantaneous water
heaters produced converted UEF values above the measured UEF values for
11 units,
[[Page 59776]]
below the measured UEF values for 11 units, and equal to for 8 units,
when rounded to the second decimal place, suggesting the conversion is
representing the non-condensing category as well as can be expected,
given the variance in the non-condensing test data, and is not skewed
toward over- or under-predicting the UEF of these units. Further, when
separate conversion equations are derived for condensing and non-
condensing gas-fired instantaneous water heaters, the RMSD values for
non-condensing and condensing instantaneous water heaters only improve
by 0.003 and 0.001, respectively. DOE has tentatively determined that
this improvement is negligible when weighed against the added
complexity of an additional conversion factor. As stated in section
III.E.1, DOE tentatively considers a change in RMSD to be negligible if
it is less than one unit (0.01 for EF and UEF, 0.1 for maximum GPM, and
1.0 for first-hour rating). In this case, 0.003 and 0.001 are less than
0.01 and would be unlikely to have a noticeable effect when UEF is
rounded to the nearest 0.01 per the reporting requirements in 10 CFR
429.17. NEEA's suggestions about improving the instantaneous analytical
conversion were previously discussed in section III.C.4.c of this
notice.
c. Residential-Duty Commercial Storage Water Heaters
i. Test Results
DOE has tested 8 residential-duty commercial storage water heaters
to both the thermal efficiency and standby loss and UEF test
procedures, and AHRI has supplied test data for 12 additional units of
this kind of water heater.\15\ Table III.35 below presents the test
data used to derive the residential-duty commercial storage water
heater conversion factors. Table III.36 shows the water heater
attributes by unit described in section III.E.1.
---------------------------------------------------------------------------
\15\ If multiple tests were conducted on either the same unit or
same basic model of a water heater, the results were averaged to
produce the values reported in this SNOPR.
Table III.35--Residential-Duty Commercial Water Heater Test Data
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Thermal
RDS No AHRI No Type Storage Input rate efficiency Standby loss Updated FHR UEF
volume (gal) (Btu/h) (%) (Btu/h) (gal)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1....................................... N/A....................... Gas....................... 72.9 75,600 74.1 1007.0 107.4 0.612
2....................................... N/A....................... Gas....................... 48.3 76,500 93.6 328.0 137.0 0.816
3....................................... N/A....................... Gas....................... 93.7 78,900 80.4 1178.2 109.8 0.514
4....................................... N/A....................... Gas....................... 70.9 76,900 82.8 580.2 156.4 0.710
5....................................... N/A....................... Gas....................... 94.9 83,700 80.0 1389.9 159.2 0.524
6....................................... N/A....................... Gas....................... 69.6 75,600 76.9 1407.2 130.0 0.505
7....................................... N/A....................... Oil....................... 50.3 140,000 76.7 908.2 134.8 0.617
8....................................... N/A....................... Gas....................... 48.4 75,500 89.5 348.3 114.9 0.722
9....................................... 1-105..................... Gas....................... 93.1 75,200 80.1 1163.3 140.9 0.561
10...................................... 2-14...................... Gas....................... 49.0 76,800 97.3 150.0 151.1 0.908
11...................................... 2-15...................... Gas....................... 49.0 76,800 97.3 150.0 156.8 0.891
12...................................... 1-122..................... Gas....................... 71.3 79,600 82.7 789.0 131.0 0.650
13...................................... 1-120..................... Gas....................... 49.0 76,800 97.3 150.0 154.0 0.907
14...................................... 1-114, 115................ Gas....................... 48.3 75,100 92.6 290.5 119.1 0.877
15...................................... 1-106, 107................ Gas....................... 70.8 74,600 80.0 1052.0 113.8 0.625
16...................................... 1-110, 111................ Gas....................... 71.1 75,100 81.0 921.0 107.6 0.642
17...................................... 1-108, 109................ Gas....................... 95.0 74,000 80.5 1064.5 140.0 0.596
18...................................... 1-112, 113................ Gas....................... 94.9 74,700 81.5 1063.0 125.9 0.587
19...................................... 1-116, 117................ Gas....................... 49.4 101,300 96.5 422.5 109.9 0.865
20...................................... 1-118, 119................ Gas....................... 74.2 101,400 96.0 408.5 174.0 0.842
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table III.36--Residential-Duty Commercial Water Heater Attributes
--------------------------------------------------------------------------------------------------------------------------------------------------------
RDS No NOX Emission level Condensing Vent type Short or Tall Standing Pilot?
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.................................. Low................... No.................... Power................ Tall................. Yes.
2.................................. Low................... Yes................... Power................ Short................ No
3.................................. Standard.............. No.................... Atmospheric.......... Tall................. Yes.
4.................................. Standard.............. No.................... Power................ Tall................. No
5.................................. Ultra-Low............. No.................... Atmospheric.......... Not Specified........ Yes.
6.................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
7.................................. N/A................... N/A................... N/A.................. Short................ N/A.
8.................................. Low................... Yes................... Power................ Tall................. No
9.................................. Low................... No.................... Atmospheric.......... Tall................. Yes.
10................................. Low................... Yes................... Power................ Not Specified........ No
11................................. Low................... Yes................... Power................ Not Specified........ No
12................................. Low................... Yes................... Power................ Tall................. No
13................................. Not Specified......... Yes................... Power................ Not Specified........ No
[[Page 59777]]
14................................. Low................... Yes................... Power................ Tall................. No
15................................. Standard.............. No.................... Atmospheric.......... Tall................. Yes.
16................................. Standard.............. No.................... Atmospheric.......... Tall................. Yes.
17................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
18................................. Ultra-Low............. No.................... Atmospheric.......... Tall................. Yes.
19................................. Ultra-Low............. Yes................... Power................ Tall................. No
20................................. Ultra-Low............. Yes................... Power................ Tall................. No
--------------------------------------------------------------------------------------------------------------------------------------------------------
ii. Conversion Factor Results
As stated in section III.C.4.b, DOE is not aware of an analytical
model to convert the represented values of thermal efficiency and
standby loss under the prior commercial test procedure to estimate the
represented value of first-hour rating under the new test procedure.
Therefore, DOE proposes to use the step regression method described in
section III.C.2 along with the best combination of water heater
attributes to determine the first-hour rating conversion factor shown
in Table III.37. 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, the value can be applied to determine the
appropriate draw pattern bin (i.e., very small, low, medium, or high)
using Table 1 of the uniform efficiency descriptor test procedure. 10
CFR 430, subpart B, appendix E, section 5.4.1. With the draw bin known,
the UEF value based on the analytical model can be calculated using the
process described in section III.C.4 of this document. The analytical
results, along with the results of the step regression and the
analytical regression, are presented in Table III.38 and have RMSD
values of 0.032, 0.029, and 0.032, respectively. DOE proposes to use
the combined analytical-regression approach to calculate the
residential-duty commercial storage water heater conversion factor
because the RMSD value is within 0.003 of that of the regression and
the use of the analytical portion of the conversion will likely apply
better to units that have not been tested. The resulting equations for
determining the UEF of residential-duty commercial storage water
heaters are presented in Table III.37. In the equations in Table
III.37, Vr is the rated volume, and Et is the
thermal efficiency in fractional form (e.g., 0.85 instead of 85 (%)).
UEFrd is the result of the analytical conversion, described
in section III.C.4.c. For these regressions, DOE decided to group both
oil-fired and gas-fired water heaters because of the lack of oil-fired
water heaters identified.
Table III.37--Proposed Residential-Duty Commercial Storage Conversion
Factor Equations
------------------------------------------------------------------------
Product class Conversion factor
------------------------------------------------------------------------
All Residential-Duty Commercial Storage New FHR = -35.8233 + 0.4649 x
Water Heaters. Vr + 160.5089 x Et
New UEF = -0.0022 + 1.0002 x
UEFrd
------------------------------------------------------------------------
Table III.38--Residential-Duty Commercial Storage Conversion Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Analytical-
RDS No. Tested FHR Regression FHR Tested UEF Analytical UEF Regression UEF Regression
(gal) (gal) UEF
--------------------------------------------------------------------------------------------------------------------------------------------------------
1....................................................... 107.4 117.0 0.612 0.567 0.559 0.565
2....................................................... 137.0 136.9 0.816 0.830 0.831 0.828
3....................................................... 109.8 136.8 0.514 0.578 0.567 0.576
4....................................................... 156.4 130.1 0.710 0.691 0.700 0.689
5....................................................... 159.2 136.7 0.524 0.548 0.527 0.546
6....................................................... 130.0 120.0 0.505 0.532 0.509 0.530
7....................................................... 134.8 110.7 0.617 0.594 0.626 0.592
8....................................................... 114.9 130.3 0.722 0.793 0.798 0.790
9....................................................... 140.9 136.0 0.561 0.579 0.566 0.577
10...................................................... 151.1 143.2 0.908 0.918 0.890 0.916
11...................................................... 156.8 143.2 0.891 0.918 0.890 0.916
12...................................................... 131.0 130.1 0.650 0.651 0.662 0.649
13...................................................... 154.0 143.2 0.907 0.918 0.890 0.916
14...................................................... 119.1 135.2 0.877 0.833 0.830 0.831
15...................................................... 113.8 125.5 0.625 0.594 0.594 0.592
16...................................................... 107.6 127.3 0.642 0.620 0.625 0.617
17...................................................... 140.0 137.5 0.596 0.595 0.585 0.593
18...................................................... 125.9 139.1 0.587 0.601 0.593 0.599
19...................................................... 109.9 142.0 0.865 0.825 0.843 0.823
20...................................................... 174.0 152.8 0.842 0.825 0.832 0.823
--------------------------------------------------------------------------------------------------------------------------------------------------------
In response to the NOPR, AHRI stated that for gas-fired
residential-duty commercial storage water heaters, all the measured UEF
results are higher than the converted UEF values using the mathematical
conversion, and the commenters added that the magnitude of the
difference seems to track with the volume and thermal efficiency of the
water heater. (AHRI, No. 6 at p. 2) Bradford White stated that its
results show that both the UEF and FHR are largely underestimated for
residential-duty commercial gas-fired water heaters when using the
conversion factors.
[[Page 59778]]
(Bradford White, No. 14 at p. 2) NEEA stated that for residential-duty
commercial water heaters, there is so little correlation between the
FHR and UEF calculated from the mathematical conversions and the
measured values from testing that it is not possible at this point to
use an analytical approach for determining either of these values.
(NEEA, No. 15 at p. 6) NEEA elaborated that it is also not clear at
this point that more testing (more sample models) would be helpful, as
NEEA believes there are some missing variables/factors that are not
being taken into account in the analytical methodologies. NEEA
tentatively concluded that these water heaters will have to be tested
in the near term in order to produce represented values of FHR and UEF
that will match the represented values later when all water heaters
must be re-certified based on tested values. (NEEA, No. 15 at p. 6)
In response to AHRI and Bradford White's comment about the gas-
fired storage conversion underrating the UEF, DOE notes that under the
conversion factor proposed in this SNOPR, there are a similar number of
gas-fired residential-duty commercial units where the converted UEF is
either higher or lower than the measured UEF,\16\ which suggests that
the new conversion is a better representation of the test data than was
proposed in the NOPR. Further, the RMSD values for the NOPR and SNOPR
conversions with the current data set are 0.068 and 0.032,
respectively. In response to NEEA comments, DOE notes that the
analytical method was updated based on other commenters' suggestions,
and that the resulting new conversion tracks better with the measured
data than the conversion factor equation proposed in the NOPR.
---------------------------------------------------------------------------
\16\ Of the 20 residential-duty commercial units tested, 9 had a
UEF value predicted by the conversion equation that was lower than
the measured UEF; 7 units had a predicted UEF that was higher than
the measured UEF, and 4 units had a predicted UEF that was equal to
the measured UEF, after rounding to the second decimal place.
---------------------------------------------------------------------------
d. Residential-Duty Commercial Instantaneous Water Heaters
As discussed in section III.B, DOE did not propose a mathematical
conversion for residential-duty commercial gas-fired instantaneous
water heaters in the April 2015 NOPR. The definition of residential-
duty commercial water heater applies to commercial equipment and
specifically excludes gas-fired instantaneous water heaters with an
input rating above 200,000 Btu/h. 10 CFR 431.102. As defined in EPCA,
gas-fired instantaneous water heaters with an input rating at or below
200,000 Btu/h are consumer products, not commercial equipment. (42
U.S.C. 6291(27)(B)) As such, the definition of residential-duty
commercial water heater definition precludes all gas-fired
instantaneous water heaters from being so defined.
DOE has tentatively concluded a mathematical conversion factor and
standard denominated in UEF are necessary for residential-duty
commercial electric instantaneous water heaters. DOE tested 1
residential-duty commercial electric instantaneous water heater to the
test procedure that was proposed in the UEF test procedure NOPR. 78 FR
66202 (Nov. 4, 2013). The maximum GPM conversion is based on a
regression, and DOE included this data point for the residential-duty
commercial electric instantaneous unit in that conversion without the
need for further testing, because there were no substantial changes to
the maximum GPM test for electric instantaneous water heaters between
the UEF test procedure NOPR and final rule. Because of the small amount
of data available and the relative similarity between units above and
below the 12 kW cut-off between consumer and residential-duty
commercial water heaters, DOE also used the 5 consumer electric
instantaneous water heaters that were tested (see section III.E.2.b) in
the development of the mathematical conversion factor for the maximum
GPM of residential-duty commercial electric instantaneous water
heaters. Table III.39 below presents the residential-duty commercial
electric instantaneous water heater test data used to develop the
conversion factors.
Table III.39--Residential-Duty Commercial Instantaneous Water Heater
Test Data
------------------------------------------------------------------------
Input
RDI No. rate Updated UEF
(Btu/h) max GPM
------------------------------------------------------------------------
1...................................... 83,600 2.48 0.948
------------------------------------------------------------------------
DOE examined potential parameters for predicting the maximum GPM
rating of residential-duty commercial electric instantaneous water
heaters. Given the de minimis losses from electric heating elements,
and the de minimis standby losses associated with tankless water
heaters, DOE believes that it is appropriate to assume that the
delivery capacity would be heavily dependent on the input rating for
electric instantaneous water heaters. DOE examined the predicted
maximum GPM as a function of input rate, and developed an equation
which results in an RMSD of 0.009 gpm. DOE proposes to use the
following equation as the mathematical conversion factor for max GPM,
where Q is input rate in kBtu/h.
New Max GPM = 0.0146 + 0.0295 * Q
DOE has tentatively determined that the UEF value shown in Table
III.39, which is a result of the UEF test procedure NOPR is not
appropriate for use in a regression based conversion. As described in
section III.C.4.c.iv, DOE has proposed an analytical method for
determining the UEF conversion, and as such, this test point was not
necessary to develop the UEF conversion. DOE proposes to use the
analytical method described in section III.C.4.c.iv as the conversion
for residential-duty commercial electric instantaneous water heaters.
e. Grid-Enabled Storage Water Heaters
Grid-enabled water heaters have a rated storage volume above 75
gallons and use electric resistance elements to heat the stored water.
At the time of its analysis for this notice, DOE was unable to find
grid-enabled water heaters available on the market which meet the
definition of ``grid-enabled water heater'' \17\ as set forth in EEIA
2015. As a result, DOE does not have any test data for grid-enabled
water heaters specifically. However, DOE does have a large set of data
for electric resistance storage water heaters, which DOE believes would
have similar energy consumption-related characteristics to grid-enabled
water heaters, aside from the differences in stored volume. DOE has
conducted testing of 18 consumer electric storage water heaters, which
use electric resistance elements and were
[[Page 59779]]
tested to both the EF and UEF test procedures, and AHRI has supplied
test data for 27 additional units of this water heater type. DOE
believes that the electric resistance technology used in grid-enabled
water heaters to heat water would be similar enough to the technology
used in the less than or equal to 55 gallon class of consumer electric
water heaters to be applicable in the derivation of the grid-enabled
conversion and energy conservation standard derivation. Similarly, the
insulation type and thickness in grid-enabled water heaters is expected
to be the same as that currently used in electric storage water heaters
with storage volumes less than or equal to 55 gallons. Therefore, DOE
used the same test data to derive the grid-enabled consumer storage
water heater conversion factors as was used to derive the consumer
electric storage water heater conversion factor.
---------------------------------------------------------------------------
\17\ Grid-enabled water heater means an electric resistance
water heater that--
(1) Has a rated storage tank volume of more than 75 gallons;
(2) Is manufactured on or after April 16, 2015;
(3) has: (i) An energy factor of not less than 1.061 minus the
product obtained by multiplying--(a) the rated storage volume of the
tank, expressed in gallons, and (b) 0.00168; or (2) an equivalent
alternative standard prescribed by the Secretary and developed
pursuant to 42 U.S.C. 6295(e)(5)(E);
(4) Is equipped at the point of manufacture with an activation
lock and;
(5) Bears a permanent label applied by the manufacturer that--
(i) Is made of material not adversely affected by water;
(ii) Is attached by means of non-water-soluble adhesive; and
(iii) Advises purchasers and end-users of the intended and
appropriate use of the product with the following notice printed in
16.5 point Arial Narrow Bold font: ``IMPORTANT INFORMATION: This
water heater is intended only for use as part of an electric thermal
storage or demand response program. It will not provide adequate hot
water unless enrolled in such a program and activated by your
utility company or another program operator. Confirm the
availability of a program in your local area before purchasing or
installing this product.''
(42 U.S.C. 6295(e)(6)(A)(ii))
---------------------------------------------------------------------------
For the first-hour rating conversion, the only conversion method
available is the regression approach. Therefore, the data set of
electric resistance consumer electric storage water heaters was used to
derive the following equation:
New FHR = 9.2827 + 0.8092 x FHRP
As with electric storage water heaters with storage volumes less
than 55 gallons, DOE used the hybrid approach of using both the WHAM
equation and a regression to calculate the UEF. Because no grid-enabled
water heater products are available on the market, DOE applied the
regression equations derived using the electric storage water heaters
with storage volumes less than 55 gallons since the technology employed
is very similar. DOE is proposing to use the following conversion
equations to determine the UEF (shown as ``New UEF'' in the equation):
[GRAPHIC] [TIFF OMITTED] TP30AU16.037
DOE considered simply using the WHAM equation for the conversion of
grid-enabled water heaters, but the inclusion of the regression step
makes the corresponding energy conservation standards (discussed in
III.E.3) more consistent with those developed for electric storage
water heaters with storage volumes at or below 55 gallons, which DOE
believes are very similar products at lower storage volumes. DOE seeks
comment on its method of applying the regression for electric storage
water heaters with storage volumes at or below 55 gallons in developing
the conversion equation for grid-enabled water heaters. This is
identified as issue 1 in section V.B, ``Issues on Which DOE Seeks
Comment.''
3. Energy Conservation Standard Derivation
After developing the mathematical conversion factors to convert
from the prior tested values under the EF metric to the tested values
under the UEF metric, the next step is to translate the energy
conservation standards to be in terms of UEF. In the April 2015 NOPR
analysis, DOE investigated several possible methods to determine the
appropriate energy conservation standards in terms of UEF, and sought
comments on the various approaches. 80 FR 20116, 20136-38 (April 14,
2015). DOE ultimately proposed using the ``percent difference'' method,
which would have updated the minimum standards by first calculating the
percent difference between the prior EF rating and standard for each
model on the market, and then applying that percent difference to the
estimated UEF (based on the conversion factor) to determine the new
minimum UEF requirement that maintains the same stringency. However,
because the ``percent difference'' method was based on actual water
heaters from the CCMS and AHRI directories, the method could only
directly be applied to categories that had water heaters in them. Thus,
DOE had to extrapolate standards from similar classes for categories
where there were no models on the market, such as the consumer gas-
fired storage water heaters greater than 55 gallons category. For this
SNOPR, DOE has developed a new methodology that it proposes for
translating the energy conservation standards to UEF, which DOE
believes would improve the results of the standards translation. DOE
has termed this new approach as the ``representative model'' method,
which consists of the following steps for determining the minimum UEF
standard:
1. Using the CCMS and AHRI directories, for minimally-compliant
models, determine the unique rated storage volumes available on the
market prior to July 13, 2015 (the date on which DOE's requirement that
rated storage volume equal the mean of the measured storage volume was
effective; see section III.E.3.a).
2. For each rated storage volume identified in step 1, find average
values of conversion factor inputs (i.e., input rating and recovery
efficiency for consumer water heaters (except consumer heat pump water
heaters), and input rating for residential-duty commercial water
heaters) for minimally-compliant models in each product class. (For
product classes where no minimally-compliant models exist on the
market, DOE used other methods to estimate the characteristics of
minimally-compliant models, as discussed in detail subsequently.)
3. Calculate the energy conservation standard (in terms of EF for
consumer water heaters and TE/SL for residential-duty commercial water
heaters (with input rate for determining standards found from step 2))
for each product class based on the rated storage volume, as reported
in the CCMS and AHRI directories at the time of this analysis (before
DOE's requirement that rated storage volume equal the mean of the
measured storage volume was effective).
4. Using applicable average values for conversion factor inputs
determined in step 2 and the applicable minimum energy conservation
standards calculated in step 3, calculate the equivalent UEF for
minimally-compliant models at each discrete rated storage volume
(determined in step 1) using the appropriate conversion factor for the
product class.
5. Adjust the rated storage volumes to estimate the rated storage
volume that would reflect DOE's requirement at 10 CFR
429.17(a)(1)(ii)(C) that rated storage volume equal the mean of the
measured storage volume of all units within the sample. DOE estimated
that for electric storage water heaters, the rated storage volume would
decrease by 10 percent, and for gas-fired and oil-fired water
[[Page 59780]]
heaters, the rated storage volume would decrease by 5 percent.
6. For each product class and draw pattern, using a simple
regression, find the slope and intercept where the independent variable
is the range of adjusted rated storage volumes (determined in step 5)
and the dependent variable is the UEF values associated with the rated
storage volumes and specific draw pattern calculated in step 4.
As discussed in section III.B, the energy conservation standards
for water heaters established in EPCA (and for electric water heaters,
the standards as adjusted by the 1990 test procedure final rule) apply
to all consumer water heaters regardless of storage volume or input
rate. Therefore, in addition to the classes of water heaters for which
DOE proposed UEF-based standards in the NOPR, DOE is also proposing
updated standards based on the UEF test procedure for the types of
water heaters described in Table III.1.\18\ Although there were few or
no water heaters in those categories described in Table III.I, DOE used
the ``representative model'' method described previously by estimating
values for input rate and recovery efficiency to determine the
converted UEF standard level.
---------------------------------------------------------------------------
\18\ These water heaters include gas-fired storage, electric
storage, and tabletop water heaters at or above 2 gallons storage
volume and below 20 gallons storage volume; gas-fired storage water
heaters above 100 gallons storage volume; oil-fired storage water
heaters above 50 gallons storage volume; electric storage water
heaters above 120 gallons storage volume; gas-fired instantaneous
water heaters with an input at or below 50,000 Btu/h or at or above
2 gallons storage volume; electric instantaneous water heaters at or
above 2 gallons storage volume; and oil-fired electric instantaneous
water heaters.
---------------------------------------------------------------------------
For consumer gas-fired storage water heaters, there are three
separate conversion factors: (1) For standard (i.e., not low
NOX or ultra-low NOX) and low NOX non-
condensing models; (2) for ultra-low NOX non-condensing
models; and (3) for condensing models. For water heaters with a storage
volume less than or equal to 55 gallons, the conversion factor for
standard and low NOX non-condensing models was used to
develop the proposed updated energy conservation standard, as the
standard for gas-fired storage water heaters with a storage volume less
than or equal to 55 gallons is at a non-condensing level. DOE chose to
use the equation for standard and low NOX non-condensing
models, rather than for ultra-low NOX non-condensing models,
since standard and low NOX non-condensing models make up the
majority of the gas-fired storage water heater market. DOE considered
proposing to establish separate standards for ultra-low NOX
models based on the conversion factor for these products, but found
that the slight differences in the resultant standards for ultra-low-
NOX water heaters would not justify the additional
complexity in the Department's water heater regulations if separate
standards were to be developed. The average difference between the
standard and low-NOX and ultra-low-NOX energy
conservation standards for the very small, low, medium, and high draw
patterns, was -0.041, -0.008, -0.006, and 0.003, respectively.\19\
Manufacturers are required to certify UEF values rounded to the nearest
0.01 (10 CFR 429.17(b)(2)), so differences lower than that would
effectively result in the same standard level for the majority of units
on the market. The very small draw pattern standard would not be
expected to have a negligible difference; however, DOE is not aware of
any units that are on the market which would test to this draw pattern.
DOE did not consider using the condensing gas-fired storage conversion
for units less than or equal to 55 gallons because the resulting
standard would be much more stringent than the current energy
conservation standards. DOE seeks comments on the use of the standard
and low-NOX conversion to calculate the energy conservation
standard for consumer gas-fired storage water heaters less than or
equal to 55 gallons, and its tentative decision not to propose separate
standards for ultra-low NOX gas-fired storage water heaters.
This is identified as issue 2 in section V.B, ``Issues on Which DOE
Seeks Comment.''
---------------------------------------------------------------------------
\19\ Averages differences are calculated using storage volumes
from 20 to 55 gallons, in increments of 1 gallon, where the minimum
UEF values have been rounded to the nearest 0.01.
---------------------------------------------------------------------------
For consumer gas-fired storage water heaters above 55 gallons,
there are no water heaters on the market; therefore, DOE assumed the
input rate to be 65 kBtu/h and the recovery efficiency to be 0.90 when
performing the conversion to UEF for translating the standard. The
input rate of 65 kBtu/h was determined based on listings available in
the AHRI Directory at the time of this analysis. DOE examined all
models listed in the AHRI Directory (including those marked as
discontinued or obsolete) and determined that the median input rate of
gas-fired storage water heaters above 55 gallons is 65 kBtu/h, which is
also the most frequently occurring input rate. DOE used 0.90 as the
recovery efficiency based on the recovery efficiency of the only two
condensing consumer water heater models that DOE has identified on the
market (both of which have storage volume below 55 gallons). DOE used
these values along with the conversion factor for condensing gas-fired
storage water heaters to derive the above 55-gallon energy conservation
standard. DOE seeks comments from stakeholders regarding its
assumptions for the typical input rating and recovery efficiency of
consumer gas-fired storage water heaters above 55 gallons. This is
identified as issue 3 in section V.B, ``Issues on Which DOE Seeks
Comment.''
In the consumer electric instantaneous water heaters product class,
there are no minimally-compliant models available on the market.
Therefore, DOE estimated the recovery efficiency for minimally
compliant models in order to perform the calculations required to
convert the standard. The recovery efficiency of models available on
the market is 0.98, while the average EF available on the market was
0.99. Given the similarity of the EF rating and recovery efficiency
observed in electric instantaneous models, DOE estimated the recovery
efficiency of minimally-compliant models as being equal to the EF
(which at the minimally-compliant level is 0.93). DOE recognizes,
however, that it is unlikely that a model using electric resistance
elements would have a recovery efficiency of 0.93, but rather, it is
more likely that the recovery efficiency of a minimally compliant model
would be maintained at 0.98 while additional standby losses or cycling
losses would result in a lower EF. Given the design of products
currently on the market (upon which the conversion factor is based),
both cycling and standby losses are minimal, and as a result, the
conversion factor is based almost entirely on recovery efficiency.
Therefore, DOE approximated a reduction in cycling and standby losses
by lowering recovery efficiency such that the overall converted UEF
would be lowered, in order to keep the converted standard at an
equivalent level; without this reduction, the resulting standard level
would be set much closer to the level of performance of current models,
which would represent an increase in stringency. DOE seeks comment on
this approach for estimating the recovery efficiency of a minimally-
compliant (i.e., 0.93 EF) electric instantaneous water heater. This is
identified as issue 4 in section V.B, ``Issues on Which DOE Seeks
Comment.'' The current DOE-prescribed energy conservation standard for
electric instantaneous water heaters at 10 CFR 430.32(d) is at the same
level
[[Page 59781]]
as those set forth in EPCA (42 U.S.C. 6295(e)(1)(C)) and shown in Table
I.1. These standards are not limited by storage volume, and, therefore,
DOE has tentatively decided to propose one set of standard equations
for all storage volumes of consumer electric instantaneous water
heaters (0 to 10.24 gallons).\20\ To derive the updated energy
conservation standards for consumer electric instantaneous water
heaters below 2 gallons, the instantaneous conversion was used, and for
units at or above 2 gallons, the storage conversion was used. DOE
believes the use of the storage conversion factor for representative
units at or above 2 gallons is more appropriate given the greater
standby losses which would occur during the tests of these units. DOE
notes that the instantaneous conversion estimates cycling losses for
instantaneous water heaters and that the storage conversion estimates
standby losses. Average input rates for units on the market were used
for below 2 gallons units, and an input rate of 12 kW was assumed for
all at or above 2 gallons units.
---------------------------------------------------------------------------
\20\ 10.24 gallons is the maximum possible storage volume for an
electric instantaneous water heater because EPCA defines these
products as having no more than one gallon of water per 4,000 Btu
per hour of input and a maximum input rating of 12 kW. 12 kW
converts to 40,946 Btu/h, which when divided by 4,000 Btu/h results
in a maximum storage volume of 10.24 gallons to be considered as an
electric instantaneous water heater.
---------------------------------------------------------------------------
For grid-enabled storage water heaters, there were no minimally-
compliant models available on the market at the time of analysis, so
DOE assumed representative volumes of 75 and 120 gallons and input
rates of 4.5 kW at both volumes.
For consumer electric storage water heaters below 20 gallons, DOE
found that there were units on the market, but these units were not
reported in the AHRI or CCMS databases. DOE searched through
manufacturers' product literature to compile a list of units with their
respective storage volumes and input rates. At each rated storage
volume, the associated input rates were averaged to obtain a
representative value. For consumer electric storage water heaters above
120 gallons, DOE found that there were no units on the market.
Therefore, DOE assumed representative rated storage volumes of 121
gallons and 705 gallons. The upper bound of 705 gallons is the point at
which the applicable EPCA standard, found in Table I.1, would be zero.
The recovery efficiency is assumed to be 98 percent for all water
heaters using submerged electric resistance heating elements, and the
input rate for units with a capacity above 120 gallons is assumed to be
12 kW (i.e., the maximum allowable input capacity in the consumer
electric water heater class).
For consumer tabletop water heaters with storage volumes below 20
gallons or above 120 gallons, the current DOE-prescribed energy
conservation standards are at the same level as those prescribed in the
EPCA standards, found in Table I.1. Therefore, DOE tentatively proposes
to extend the updated energy conservation standards derived for units
between 20 and 120 gallons to all tabletop units, regardless of storage
volume.
For consumer gas-fired storage water heaters, less than 20 gallons
and greater than 100 gallons, DOE found that there were no units
currently on the market. Therefore, DOE assumed that if such models
were to exist in the less than 20 gallon size, they would have a
similar representative storage volume as for consumer electric storage
water heaters less than 20 gallons, and used those values as
representative storage volumes. For storage volumes above 100 gallons,
DOE used representative storage volumes of 101 and 326 gallons which
represent the lower and upper bounds, respectively. The upper bound of
326 gallons is the point at which the applicable EPCA standard, found
in Table I.1, would be zero, and DOE used this as the upper bound for
storage capacity. The recovery efficiency for all units is assumed to
be the average of the recovery efficiencies available for minimally
compliant units between 20 and 55 gallons, which was found to be 79
percent. DOE observed in the AHRI and CCMS databases that there was one
consumer gas-fired storage water heater at 20 gallons, which had an
input rate of 75,000 Btu/h. This suggests that the design of consumer
gas-fired storage water heaters below 20 gallons would trend towards
higher input rates. Therefore, DOE assumed input rates for units below
20 gallons to be at the 4,000 Btu/h/gal limitation between storage and
instantaneous water heaters, which is the maximum input allowable to be
within the gas-fired storage water heater product class for a given
volume. (42 U.S.C. 6291(27)(B)) An input rate of 75,000 Btu/h was used
for storage volumes where the input rate using the 4,000 Btu/h/gal
limitation would result in a value greater than 75,000 Btu/h, as that
is the maximum input capacity for consumer gas-fired storage water
heaters. For consumer gas-fired storage water heaters with greater than
100 gallons storage volume, the input rate was assumed to be 75,000
Btu/h.
For consumer oil-fired storage water heaters with a capacity above
50 gallons, recovery efficiency and input rate values are assumed to be
85 percent and 105,000 Btu/h, respectively.
For consumer oil-fired instantaneous water heaters, the maximum
possible input rate as defined by EPCA at 42 U.S.C. 6291(27)(B) is
210,000 Btu/h. This input rate corresponds to a maximum storage volume
of 52.5 gallons (based on the 4,000 Btu/h per gallon of stored water
limitation between instantaneous and storage water heaters). Due to the
large storage volumes that are possible in this class of water heater,
the consumer oil-fired storage conversion was used to derive the
updated UEF standards. The average storage volume, input rate, and
recovery efficiency for units on the market is 5 gallons, 148,000 Btu/
h, and 88 percent, respectively. Therefore, DOE used the representative
market average data point along with the largest possible storage
volume and input rate to determine the energy conservation standards
equation in terms of UEF. A recovery efficiency of 88 percent was also
used for the 52.5 gallon data point.
For consumer gas-fired instantaneous water heaters the current DOE-
prescribed energy conservation standards (as amended in the April 2010
final rule and with which compliance was required in April 2015) cover
models with: (1) Storage volumes below 2 gallons or (2) an input rate
above 50,000 Btu/h. All other consumer gas-fired instantaneous water
heaters would be subject to the standards initially established by EPCA
shown in Table I.1. These two attributes are not mutually exclusive;
that is, a unit could exist that has a rated storage volume at or above
2 gallons and an input rate at or below 50,000 Btu/h. DOE considered
proposing a separate set of standards for each unique storage volume
and input rate combination (e.g., above 50,000 Btu/h and at or above 2
gallons, at or below 50,000 Btu/h and below 2 gallons, or at or below
50,000 Btu/h and at or above 2 gallons), or proposing a single standard
that would cover all consumer gas-fired instantaneous water heaters
with storage volume at or above 2 gallons, or input rate at or below
50,000 Btu/h. Over the range of applicable storage volumes, the methods
produce UEF values that are within 0.01 of each other. Therefore, to
reduce the complexity of its standards for water heaters, DOE proposes
to use a single set of standard equations for consumer gas-fired
instantaneous water heaters with rated storage volumes at or above 2
gallons or input rates at or below 50,000 Btu/h. Representative storage
volumes of 0, 2, 12.5, and 50 gallons were used to derive the updated
standards. These
[[Page 59782]]
storage volumes represent various key points. The storage volumes 0
gallons and 12.5 gallons represent the bounds of instantaneous water
heaters with an input rate at or below 50,000 Btu/h. (Because an
instantaneous water heater is defined as containing no more than 1
gallon of stored water per 4,000 Btu/h of input, the maximum storage
volume for a 50,000 Btu/h instantaneous water heater is 12.5 gallons.)
The storage volumes 2 and 50 gallons represent the bounds of
instantaneous water heaters with storage volumes at or above 2 gallons.
(Consumer instantaneous water heaters have a maximum input rate of
200,000 Btu/h. Because instantaneous water heaters are defined as
having no more than 1 gallon of stored water per 4,000 Btu/h of input,
the maximum storage volume for a 200,000 Btu/h consumer instantaneous
water heater is 50 gallons.) DOE assumed that for models at or below
50,000, Btu/h the representative input rate would be 50,000 Btu/h. For
the models with a storage volume at 2 gallons, DOE used the input rate
at the average of models currently available on the market for
minimally compliant units with 0 gallons of storage volume as the
representative input rate. DOE assumed that the input rate of such a
unit would be similar to models on the market with no storage volume.
For models with a storage volume larger than 2 gallons, DOE assumed a
representative input rate of 200,000 Btu/h. Recovery efficiencies were
assumed to be 76 percent for all volumes. This recovery efficiency
value is less than the average currently available on the market, but
DOE believes it is more representative of a unit that would have been
on the market when the EPCA standards were first prescribed. DOE used
the consumer gas-fired storage conversion to derive the updated
standards due to the storage volumes being in the range typically
observed for storage water heaters.
For residential-duty commercial oil-fired storage water heaters,
the standard increased from 78 to 80 percent in October 2015. 10 CFR
431.110. DOE used the average input rates for all residential-duty
commercial oil-fired storage water heaters that comply with the amended
standard to derive the inputs needed for the updated energy
conservation standard.
For residential-duty commercial electric instantaneous water
heaters, there were no minimally-compliant units (i.e., thermal
efficiency of 80 percent) on the market. As with consumer electric
instantaneous water heaters, DOE recognizes that it is unlikely that a
model using electric resistance elements would have a thermal
efficiency of 80 percent, and the thermal efficiency of such equipment
is likely to be much higher. However, DOE used the thermal efficiency
value of 80 percent in calculating the equivalent UEF standard, because
this represents a hypothetical minimally-compliant model. DOE used the
proposed conversion equation for each draw pattern (see section
III.E.2.d) to predict the UEF of a minimally-compliant model.
In response to the translated standards presented in the April 2015
NOPR, AHRI, Bradford White, and Rheem raised concerns that the
stringency of the updated standards was not maintained. (AHRI, No. 13
at p. 4; Bradford White, No. 14 at p. 2; Rheem, No. 11 at p. 2) In
particular, Rheem commented that 20 of the 43 consumer storage water
heaters that DOE tested in support of the NOPR generated tested UEF
values less than the applicable converted UEF value chosen by the DOE
in the NOPR. Rheem elaborated that, in order for the stringency of
energy efficiency standards to not be altered during the transition
from the UEF conversion factor period to the UEF tested value period
thereafter, a tested value of UEF for a water heater model should
comply if its converted UEF value complies with the proposed minimum
standard. (Rheem, No. 11 at p. 5) Rheem also stated that three of the
seven residential-duty commercial water heaters tested by DOE have
tested UEF values below their respective analytical-regression UEF
values. Given that these water heaters currently comply with thermal
efficiency and standby loss standards in effect and the DOE's tentative
determination in the NOPR to use the analytical-regression method to
generate the UEF conversion factor for residential-duty commercial
water heaters, Rheem asserted that there is cause for concern that the
UEF conversion factor will result in the minimum energy conservation
standard for this water heater classification becoming more stringent.
(Rheem, No. 11 at p. 5)
Bradford White asserted that the proposed converted standard in
terms of UEF for electric storage water heaters is more stringent than
the EF standard. (Bradford White, No. 14 at p. 2) AHRI also claimed
that the proposed UEF standard for electric storage water heaters is
too stringent, arguing that the converted UEF values for these models
in the NOPR were higher than the tested UEF values and that models
complying with the EF standards would not meet the UEF standards.
(AHRI, No. 6 at p. 2) Rheem asserted that for consumer electric storage
water heaters tested using the low draw pattern, test data consistently
revealed tested UEF values three to four points below the proposed UEF
minimum. For consumer electric storage water heaters tested using the
medium draw pattern, Rheem observed that there were some measured UEF
values two to three points below the proposed UEF minimum. (Rheem, No.
11 at p. 4) EEI stated that the proposed UEF minimums for electric
storage water heaters are not neutral for products representing a large
share of the consumer market. (EEI, No. 17 at p. 2)
Bradford White stated that the proposed converted standard in terms
of UEF for gas-fired storage water heaters tested using the high draw
pattern is less stringent than the EF standard, and that the standard
for models tested using the medium draw pattern would be more or less
stringent, depending on the model. (Bradford White, No. 14 at p. 2)
Rheem stated that for gas-fired storage models tested using the high
draw pattern, its test data showed measured UEF values two to three
points higher than the proposed converted UEF standards. EEI commented
that there were issues with gas-fired storage water heaters at high
draw patterns, where the converted minimum UEF standard is less
stringent than the EF standard. (EEI, No. 17 at p. 2)
Rheem commented that for several models tested by DOE (identified
in the April 2015 NOPR as CS-6, CS-13, CS-29, CS-30, and CS-39) the
measured UEF was less than the converted UEF standard. Rheem stated
that for gas-fired instantaneous water heaters that would be tested
with the medium draw pattern, the measured UEF is 1 point lower than
the proposed minimum UEF level. Rheem also stated that for gas-fired
instantaneous water heaters that would be tested with the high draw
pattern, the measured UEF is consistently 2 to 3 points higher than the
proposed minimum UEF level. (Rheem, No. 11 at p. 4) Further, Rheem
stated that after the 1 year application period of the conversion
factor, units which previously passed the minimum EF standards could
test to fail the updated minimum UEF standards. (Rheem, No. 11 at p. 3)
In response to these comments, DOE acknowledges that the test data
presented in section III.E.2 show that some units which previously
passed the EF energy conservation standards would fail the proposed UEF
standards, while other units which previously failed would now pass. As
discussed in section III.A, DOE recognizes that the conversion factors
presented cannot perfectly model the behavior of all water
[[Page 59783]]
heaters, and therefore, uncertainty is carried through to deriving the
updated energy conservation standards. The standards presented in Table
III.40 and Table III.41 were derived using a method that was intended
to reduce the number of units that would either be non-compliant under
the EF test method and compliant under the UEF test method or vice
versa, so as to maintain the stringency of the updated standard.
Nevertheless, to ensure that water heaters which previously passed the
EF energy conservation standards will continue to comply, pre-existing
models that are compliant with the EF energy conservation standards are
``grandfathered,'' as described below in section III.F.
The proposed standards in terms of uniform energy factor are shown
below by product class and draw pattern.
Table III.40--Proposed Consumer Water Heater Energy Conservation Standards
----------------------------------------------------------------------------------------------------------------
Rated storage volume and
Product class input rating (if Draw pattern Uniform energy factor
applicable)
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage Water Heater..... <20 gal.................... Very Small............ 0.2471 - (0.0002 x
Low................... Vr).
0.5132 - (0.0012 x Vr)
Medium................ 0.5827 - (0.0015 x
Vr).
High.................. 0.6507 - (0.0019 x
Vr).
>=20 gal and <=55 gal...... Very Small............ 0.3456 - (0.0020 x
Vr).
Low................... 0.5982 - (0.0019 x
Vr).
Medium................ 0.6483 - (0.0017 x
Vr).
High.................. 0.6920 - (0.0013 x
Vr).
>55 gal and <=100 gal...... Very Small............ 0.6470 - (0.0006 x
Vr).
Low................... 0.7689 - (0.0005 x
Vr).
Medium................ 0.7897 - (0.0004 x
Vr).
High.................. 0.8072 - (0.0003 x
Vr).
>100 gal................... Very Small............ 0.1755 - (0.0006 x
Vr).
Low................... 0.4671 - (0.0015 x
Vr).
Medium................ 0.5719 - (0.0018 x
Vr).
High.................. 0.6916 - (0.0022 x
Vr).
Oil-fired Storage Water Heater..... <=50 gal................... Very Small............ 0.1822 - (-0.0001 x
Vr).
Low................... 0.5313 - (0.0014 x
Vr).
Medium................ 0.6316 - (0.0020 x
Vr).
High.................. 0.7334 - (0.0028 x
Vr).
>50 gal.................... Very Small............ 0.1068 - (0.0007 x
Vr).
Low................... 0.4190 - (0.0017 x
Vr).
Medium................ 0.5255 - (0.0021 x
Vr).
High.................. 0.6438 - (0.0025 x
Vr).
Electric Storage Water Heaters..... <20 gal.................... Very Small............ 0.7836 - (0.0013 x
Vr).
Low................... 0.8939 - (0.0008 x
Vr).
Medium................ 0.9112 - (0.0007 x
Vr).
High.................. 0.9255 - (0.0006 x
Vr).
>=20 gal and <=55 gal...... Very Small............ 0.8808 - (0.0008 x
Vr).
Low................... 0.9254 - (0.0003 x
Vr).
Medium................ 0.9307 - (0.0002 x
Vr).
High.................. 0.9349 - (0.0001 x
Vr).
>55 gal and <=120 gal...... Very Small............ 1.9236 - (0.0011 x
Vr).
Low................... 2.0440 - (0.0011 x
Vr).
Medium................ 2.1171 - (0.0011 x
Vr).
High.................. 2.2418 - (0.0011 x
Vr).
>120 gal................... Very Small............ 0.6802 - (0.0003 x
Vr).
Low................... 0.8620 - (0.0006 x
Vr).
Medium................ 0.9042 - (0.0007 x
Vr).
High.................. 0.9437 - (0.0007 x
Vr).
Tabletop Water Heater.............. All........................ Very Small............ 0.6323 - (0.0058 x
Vr).
Low................... 0.9188 - (0.0031 x
Vr).
Medium................ 0.9577 - (0.0023 x
Vr).
High.................. 0.9884 - (0.0016 x
Vr).
Instantaneous Gas-fired Water <2 gal and >50,000 Btu/h... Very Small............ 0.7964 - (0.0000 x
Heater. Vr).
Low................... 0.8055 - (0.0000 x
Vr).
Medium................ 0.8070 - (0.0000 x
Vr).
High.................. 0.8086 - (0.0000 x
Vr).
>=2 gal or <=50,000 Btu/h.. Very Small............ 0.3013 - (0.0023 x
Vr).
Low................... 0.5421 - (0.0024 x
Vr).
Medium................ 0.5942 - (0.0021 x
Vr).
High.................. 0.6415 - (0.0017 x
Vr).
Instantaneous Oil-fired Water All........................ Very Small............ 0.1430 - (0.0015 x
Heater. Vr).
Low................... 0.4455 - (0.0023 x
Vr).
Medium................ 0.5339 - (0.0023 x
Vr).
High.................. 0.6245 - (0.0021 x
Vr).
Instantaneous Electric Water Heater All........................ Very Small............ 0.9161 - (0.0039 x
Vr).
Low................... 0.9159 - (0.0009 x
Vr).
Medium................ 0.9160 - (0.0005 x
Vr).
High.................. 0.9161 - (0.0003 x
Vr).
Grid-Enabled Water Heater.......... >75 gal.................... Very Small............ 1.0136 - (0.0028 x
Vr).
[[Page 59784]]
Low................... 0.9984 - (0.0014 x
Vr).
Medium................ 0.9853 - (0.0010 x
Vr).
High.................. 0.9720 - (0.0007 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.41--Proposed Residential-Duty Commercial Water Heater Energy Conservation Standards
----------------------------------------------------------------------------------------------------------------
Product class Draw pattern Uniform energy factor
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage.................................... Very Small.................. 0.2670 - (0.0009 x Vr).
Low......................... 0.5356 - (0.0012 x Vr).
Medium...................... 0.5996 - (0.0011 x Vr).
High........................ 0.6592 - (0.0009 x Vr).
Oil-fired Storage.................................... Very Small.................. 0.2932 - (0.0015 x Vr).
Low......................... 0.5596 - (0.0018 x Vr).
Medium...................... 0.6194 - (0.0016 x Vr).
High........................ 0.6740 - (0.0013 x Vr).
Electric Instantaneous............................... Very Small.................. 0.80
Low......................... 0.80
Medium...................... 0.80
High........................ 0.80
----------------------------------------------------------------------------------------------------------------
* Vr is the rated storage volume which equals the water storage capacity of a water heater (in gallons), as
specified by the manufacturer.
Lutz suggested determining the energy conservation standards using
only test data from minimally-compliant water heaters. He stated that
this method would remove the uncertainty which compounds throughout the
conversion process. (Lutz, No. 16 at p. 3) DOE believes that an
appropriate amount of minimally-compliant water heater test data is
currently not present to pursue this method. Based on stakeholder
comments, DOE selected units for testing with a range of attributes and
associated EF levels. As the effect of the uniform efficiency
descriptor test procedure cannot be fully known without testing all
units on the market, it is a possibility that a minimally compliant
unit may perform better than a unit that was rated above the minimum.
Further, a water heater would have to have a tested EF at the minimum
energy conservation standard, not just be rated at the minimum.
Therefore, for these reasons, DOE did not use this method for deriving
the proposed standards.
Rheem and AHRI argued that the relative difference between the
minimum EF and EF should be maintained between the minimum UEF and UEF
values. (Rheem, No. 11 at p. 3; AHRI, No. 6 at p. 2) AHRI also asserted
that if the relative difference is not maintained, then a
manufacturer's investment could be wasted. (AHRI, No. 3 at p. 2) AHRI
expressed the view that it is more important to look at the difference
in the measurements between the EF and UEF test procedures, and
recommended that DOE should examine the difference in EF and UEF
measurements for models rated at the applicable minimum EF value to
help check the validity of the proposed converted minimum standards.
(AHRI, No. 13 at p. 5) DOE agrees that the relative difference between
minimum and rated values is an important factor to consider when
developing the energy conservation standards. The proposed
``representative model'' method uses the EF-denominated energy
conservation standard values to derive the new standard equations;
therefore, DOE believes the stringency of the standards is maintained
for the market as a whole. However, test data show that water heaters
do not all have the same reaction to the new test procedure, and as
such, the relative difference in the standards cannot be exactly
maintained for each individual model. In addition, not all
manufacturers rate models with the same degree of conservativism, so
the relationship between rated and measured values is not constant.
Regarding specifically the energy conservation standards for the
residential-duty commercial water heater equipment class, EEI stated
that this was a non-standard process for creating the proposed
standards. (EEI, No. 5 at p. 2) In response, DOE clarifies that DOE is
not creating new standards for residential-duty commercial water
heaters. Rather, this equipment has always been covered under the
applicable commercial water heating equipment standards. DOE is simply
translating the commercial water heating equipment standards from the
thermal efficiency and standby loss metrics in use today to the UEF
metric for the subset of commercial water heating equipment that would
meet the definition of a ``residential-duty commercial water heater''
at 10 CFR 431.102.
a. Storage Volume Used for Calculations
In the July 2014 final rule, DOE amended the certification
requirements for consumer water heaters to specify that the rated
storage volume of a water heater is the mean of the measured storage
volume. 79 FR 40542, 40565 (July 11, 2014). Commenters requested
clarification on how the rated storage volume will be applied in this
rulemaking. (AHRI, No. 3 at p. 2; A. O. Smith, No. 13 at p. 2; Bradford
White, No. 14 at p. 3; NEEA, No. 15 at p. 7; Rheem, No. 11 at p. 8)
As discussed in the preceding section, DOE has accounted for the
amended certification requirements with regard to the rated storage
volume in this rulemaking when translating the standards. First, DOE
used the rated storage volumes prior to the effective date of the
requirement that the rated storage volume of a water heater be the mean
of the measured storage volume to calculate the EF-denominated
standards with which to maintain equivalency for each model. Therefore,
the stringency of the EF-denominated standards that DOE converted did
not change due to the new certification requirements. Second, when
calculating the converted UEF standards equations, DOE adjusted the
rated storage volume to reflect its new
[[Page 59785]]
requirement that the rated storage volume be equal to the mean of the
measured volume of units in the certification sample (since the storage
volumes initially examined were certified prior to the effective date
of this requirement).
Before DOE instituted this requirement, a manufacturer had some
freedom to choose a volume rating, subject to industry safety standards
under which a rated volume had to be within 5 percent of the actual
volume for a fossil-fuel-fired water heater or within 10 percent for an
electric water heater. Meanwhile, the operation of DOE's energy
conservation standard for water heaters gave manufacturers an incentive
to rate the volumes of their products as high as possible--because the
applicable standard decreased for larger volumes. The combined effect
of these two influences, DOE believes, is that fossil-fuel-fired water
heaters ordinarily had volume ratings 5 percent higher than their
actual volumes, and electric water heaters 10 percent higher. DOE's
observations on actual products is consistent with that conclusion.
Consequently, DOE estimated the measured volume as 0.95 times
(i.e., 5 percent lower than) the rated storage volume for fossil fuel
fired water heaters and 0.90 times (i.e., 10 percent lower than) the
rated storage volume for electric water heaters. By adjusting the
storage volume to reflect what will be the new rated storage volumes
that are 5 percent or 10 percent (for fossil fuel and electric water
heaters, respectively) below the previous rated storage volume, DOE has
accounted for the change in its regulations regarding the rating of
storage volumes, and the UEF standard equation will represent the
relationship between the new rated storage volume (equivalent to the
mean of the measured storage volume for test samples) and UEF. Figure
III.1 below shows an example representation of how the energy
conservation standards are related to each other based on the rated or
estimated measured storage volumes.
BILLING CODE 6450-01-C
[GRAPHIC] [TIFF OMITTED] TP30AU16.038
BILLING CODE 6150-01-P
In the July 2014 test procedure final rule, DOE added enforcement
provisions that state that the rated value for storage volume during
enforcement testing will be considered valid only if the measurement is
within 5 percent of the certified rating. If the rated storage volume
is within 5 percent of the mean of the measured value of storage
volume, then that value will be used as the basis for calculation of
the required uniform energy factor for the basic model; otherwise, the
mean of the measured values will be used as the basis for calculation
of the required
[[Page 59786]]
uniform energy factor for the basic model. 79 FR 40542, 40566 (July 11,
2014); 10 CFR 429.134(d)(2). DOE reviewed the measured storage volume
test data for models included in the analysis for this SNOPR and
observed that for models which were tested more than once, the measured
storage volume was well within five percent of the mean of the measured
storage volumes (which will be required to be equal to the rated
storage volume under 10 CFR 429.17(a)(1)(ii)(C)) for each respective
model. The data set of models tested more than once consists of 10
unique models with 24 total storage volume tests (each model was tested
2 or 3 times). For each model, DOE calculated the mean, standard
deviation, and 99.7-percent confidence interval (i.e., 3 times the
standard deviation of the measured storage volumes) of the measured
storage volumes. DOE then compared the mean of the measured storage
volume to the 99.7-percent confidence interval to determine the percent
deviation from the mean value that would be within the 99.7-percent
confidence interval. The maximum percent change from the mean that
would be within the 99.7-percent confidence interval was slightly under
one percent. Therefore, DOE proposes to change its enforcement-specific
provisions for water heaters to specify that the rated value for
storage volume during enforcement testing will be considered valid only
if the measurement is within 2 percent of the certified rating. DOE
believes two percent more accurately reflects the level of variability
that manufacturers are currently able to achieve, and allows for
slightly more variability than what was observed in the sample set of
this SNOPR.
F. Compliance and Grandfathering
AHRI, Bradford White, Rheem, and EEI recommended that DOE should
add provisions to state that any water heater models tested and meeting
the minimum EF requirements prior to July 13, 2015 (i.e., those meeting
the standards promulgated in the April 2010 final rule and requiring
compliance on April 16, 2015), would be considered as meeting the
minimum UEF requirements. (AHRI, No. 13 at p. 8; Bradford White, No. 14
at p. 2; Rheem, No. 11 at p. 3; EEI, No. 17 at p. 3) AHRI, Bradford
White, and EEI stated that the proposed standards are to be neither
more nor less stringent than the EF-denominated standards, as stated in
42 U.S.C. 6293(e), and that this implies grandfathering water heater
models will be included in this rulemaking. (AHRI, No. 13 at p. 8;
Bradford White, No. 14 at p. 1; EEI, No. 17 at p. 3) Further, Rheem
argued that at the time of the switch from allowing the converted UEF
to requiring the tested UEF for demonstrating compliance, a tested UEF
value should comply if the converted value passes. (Rheem, No. 11 at p.
5) EEI asserted that compliance or non-compliance with the standard can
only be determined through the test procedure and that a unit which
meets the efficiency standard under the old test procedure should be
valid for sale, regardless of the conversion factor result. (EEI, No.
17 at p. 3) EEI also argued that the conversion values should only be
used on the FTC EnergyGuide label. (EEI, No. 17 at p. 3) AHRI stated
that the converted minimum UEF standards will not have perfect one-to-
one correlation with every currently complying model, and therefore, it
is essential that DOE establish how grandfathering will be applied so
that manufacturers can properly assess the validity of the converted
minimum UEF standards. (AHRI, No. 13 at p. 8)
In a paragraph titled ``Existing covered water heaters,'' EPCA
provides that a covered water heater (i.e., a water heater subject to
the UEF test procedure rule) is considered to comply with the UEF test
procedure rule on and after the effective date of the final rule (i.e.,
July 13, 2015) and with any revised labeling requirements established
by the Federal Trade Commission (FTC) to carry out the final rule if
the covered water heater was manufactured prior to the effective date
of the final rule; and (ii) complied with the efficiency standards and
labeling requirements in effect prior to the final rule. (42 U.S.C.
6295(e)(5)(K)) EPCA defines the ``final rule,'' in this context, to be
the UEF test procedure final rule. (42 U.S.C. 6295(e)(5)(A)(ii)) The
natural reading of this provision is that a water heater (a unit \21\)
manufactured prior to July 13, 2015, and compliant with the pre-
existing standards when tested using the test procedure in effect on
July 13, 2014, is deemed to comply with the UEF test procedure final
rule and any corresponding label changes made by the FTC.
---------------------------------------------------------------------------
\21\ DOE notes that EPCA appears to distinguish in paragraph
(e)(5) of section 6295 between certain provisions that apply on a
unit-by-unit basis and other provisions that apply on a model-by-
model basis.
---------------------------------------------------------------------------
Manufacturers appear to read this provision to provide
``grandfathering'' with respect to compliance with the converted
standards. The language does not provide such relief, nor is such
relief necessary. The standard applicable to a unit is the standard in
effect at the time of manufacture; therefore, units manufactured prior
to July 13, 2015, must comply with the corresponding EF/TE/STB
standards, and no ``grandfathering'' is needed. The relevance of the
UEF test procedure with respect to such units is for the purposes of
representations, which this statutory provision explicitly addresses.
Accordingly, DOE reads 42 U.S.C. 6295(e)(5)(K) to provide that
manufacturers do not have to retest units of water heaters using the
UEF test procedure if they were tested and rated prior to July 13,
2015. DOE notes there is a corresponding provision with respect to the
FTC label.
In addition, EPCA provides that manufacturers may use the
conversion factor in lieu of testing for models tested prior to July
13, 2015, for a period of one year following the publication of a final
rule. In this way, EPCA provides additional relief to manufacturers for
models of water heaters that continue to be manufactured on or after
July 13, 2015, by delaying the need to complete testing using the UEF
test procedure for those models of water heaters manufactured prior to
July 13, 2015. See 42 U.S.C. 6295(e)(5)(E) (indicating the conversion
factor applies to ``models of covered water heaters'' (emphasis
added)); compare 42 U.S.C. 6295(e)(5)(K) (referring to ``existing
covered water heaters'' and ``a covered water heater'' rather than a
``model of covered water heater'').
DOE recognizes that the nature of this conversion process could
conceivably result in a few models very close to the standard falling
below the converted standard. Although the statute does not provide
``grandfathering'' of the sort envisioned by manufacturers, DOE
believes that there is value in reducing the uncertainty for
manufacturers and that there is no significant public harm in letting
manufacturers continue sales of certain models. As discussed in great
detail throughout this notice, every model responds slightly
differently to the change in the test procedure. As a result, there is
variability, and units very near the standard level (either above or
below) could have a measured efficiency using the new test procedure
that would change the compliance status of that unit. Accordingly, DOE
will determine the compliance of a basic model--the level of
granularity typically used by DOE and manufacturers to evaluate
compliance--using the test procedure in effect prior to July 13, 2015,
under the following circumstance: The basic model must have been in
distribution in commerce prior to July 13, 2015; the basic model must
have been tested and properly certified to
[[Page 59787]]
DOE as compliant with the applicable standard prior to July 13, 2015;
and the units manufactured prior to July 13, 2015, must be essentially
identical to the units manufactured on or after July 13, 2015. The last
requirement for this policy--that units must be essentially identical--
bears explanation. DOE generally permits manufacturers great latitude
in assigning basic model numbers, and manufacturers normally are not
required to certify a model as a new basic model if modifications make
the model more efficient. In implementing this policy, DOE believes
that, if a manufacturer makes changes to a model (that make it either
more efficient or less), then it should conduct the requisite testing
using the UEF test procedure and ensure the compliance of the model
with the converted standard. This policy is intended to give certainty
to manufacturers with respect to historical models; it is not intended
to provide a mechanism to perpetuate an obsolete test method and
obsolete metrics.
In summary, EPCA provides that units of water heaters can continue
to have their efficiency represented in terms of the ``old'' metrics.
EPCA also provides that manufacturers can use the conversion factors to
determine represented values for a period of one year following
issuance of a final rule in this rulemaking for models that were being
manufactured prior to July 13, 2015. Under EPCA, units manufactured on
or after July 13, 2015, must meet the standard as denominated in the
UEF metric; however, DOE will implement an enforcement policy that DOE
will not seek civil penalties for the continued manufacture and
distribution in commerce of units of certain basic models as follows:
The basic model must have been in distribution in commerce prior to
July 13, 2015; the basic model must have been tested and properly
certified to DOE as compliant with the applicable standard prior to
July 13, 2015; and the units manufactured prior to July 13, 2015, must
be essentially identical to the units manufactured on or after July 13,
2015.
DOE recognizes that manufacturers seek certainty that models
introduced since July 13, 2015, will not be subject to civil penalties.
In enforcing the standard(s), DOE will consider whether these models
meet the standard(s) as denoted using the ``old'' metric(s), the
deviation from the UEF standard when tested using the UEF test
procedure, and efforts taken by the manufacturer to ensure compliance
with the converted, UEF standards. DOE does not intend to issue a
``grandfathering'' enforcement policy with respect to basic models
introduced on and after July 13, 2015, as such a policy does not appear
to be necessary at this time.
G. Certification
EPCA requires that the standard for covered water heaters be in
terms of UEF as of July 13, 2015. Accordingly, in the April 2015 NOPR,
DOE proposed to require manufacturers to provide EF and UEF for
consumer water heaters (or thermal efficiency and standby loss and UEF
for residential-duty commercial water heaters) in certification reports
filed between July 13, 2015, and the compliance date determined by the
final rule in this rulemaking. 80 FR 20116, 20138 (April 14, 2015). DOE
proposed that manufacturers would not be required to submit revised
certification reports for previously certified basic models until the
next annual certification date (May 1). Id.
In the April 2015 NOPR, DOE noted that 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. DOE stated that 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. Lastly, DOE stated that it 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. Id.
In his comments, Lutz requested that standby heat loss coefficient
(UA), Annual Energy Consumption (Eannual), Annual Electrical
Energy Consumption (Eannual,e), and Annual Fossil Fuel
Energy Consumption (Eannual,f) be included in the parameters
manufacturers are required to submit to DOE and further that they be
available to the public in the Compliance Certification Database. Lutz
stated that these parameters are already calculated during the UEF test
procedure and would help analysts estimate energy consumption of water
heaters when operating under conditions that do not exactly match the
draw patterns or other conditions specified in the laboratory test
procedure. (Lutz, No. 20 at p. 1) DOE has tentatively decided not to
add these values as part of the certification report; however, DOE is
specifically requesting comment from stakeholders about whether these
performance characteristics should be added in the final rule, either
as publicly reported characteristics of water heaters or as information
that is not published on the DOE Web site.
AHRI, A.O. Smith, and Rheem commented that DOE should delay the
effective date of the uniform energy descriptor test procedure. (AHRI,
No. 13 at p. 3; A.O. Smith, No. 10 at pp. 1-2; Rheem, No. 11 at p. 10)
Specifically, AHRI argued that the statutory timeline cannot override
the substantive statutory protections that Congress provided, and it is
imperative that DOE take the time and effort to conduct the testing and
analysis necessary to ensure that the statutory requirements are met.
AHRI also stated that to proceed with implementing the UED test
procedure on July 13, 2015, without the existence of appropriate
conversion factors, would violate the statute and serve no purpose
except to further confuse an already complex situation. (AHRI, No. 13
at pp. 2-3) A.O. Smith urged the postponement of the implementation
date because new models would be tested to the new test method and have
a valid UEF rating, but without a valid conversion factor in place to
convert the relevant minimum efficiency requirement into terms of UEF,
there is no basis for determining whether the new model is compliant
with minimum efficiency standards. (A.O. Smith, No. 10 at pp. 1-2)
Rheem stated that new consumer water heater models introduced in the
time period between the compliance date of the amended test procedure
and the conversion of the minimum standards will have to be certified
with the UEF descriptor in accordance with the UEF test procedure rule,
but there will be no established minimum UEF standard for that model to
achieve. Rheem asserted that such uncertainty will prevent the launch
of new consumer water heater models and cause significant harm to Rheem
and its customers. Rheem requested a delay in implementation of the
uniform energy descriptor to permit the necessary changes to product
and carton labeling and communications that display energy efficiency
metrics for all manufactured consumer and residential-duty commercial
water heater units. (Rheem, No. 11 at pp. 9-10). NEEA strongly
supported the Department's proposal to defer re-certification of
existing water heater models until May 2016, noting that manufacturers
would need time to transition to the UEF testing and/or calculation
regime
[[Page 59788]]
specified as a result of this rulemaking. (NEEA, No. 15 at p. 7)
Several commenters also cited the complexities of coordinating the
DOE metric change with the FTC labelling process, and argued that the
need for coordination with FTC should delay the implementation of the
uniform efficiency descriptor. A.O. Smith stated the need to coordinate
FTC labeling rules with the UEF requirements as a reason to delay
implementation, and elaborated that without a valid set of conversion
factors, a manufacturer will not be able to ``back calculate'' cost of
operation for the FTC label from a tested UEF. (A.O. Smith, No. 10 at
p. 2) GE commented that DOE should harmonize with the FTC labeling
process, and fully implement the UEF and conversion once the FTC label
has been modified to account for the different usage patterns in the
UEF test method. (GE, No. 12 at p. 2) Rheem recommended postponing the
adoption of reporting requirements until FTC has had an opportunity to
evaluate the EnergyGuide label and revise its format to reflect the
metrics derived from the UEF. Rheem noted that the FTC label requires
information based on the measurement of EF and that a conversion method
would be needed to calculate the EF based on the UEF. Rheem stated that
such conversions for marketing and labeling materials will result in
displays of performance and cost metrics based upon two different
energy efficiency descriptors, which will confuse consumers. Rheem also
raised concerns that the differences in energy and water consumption
based on the delivery capacity in the UEF test method will lead to
differences in annual operating costs reported on the label, which
could create an incentive for manufacturers to display the information
based on UEF for low and medium usage water heaters in order to display
expected lower operating costs. (Rheem, No. 11 at p. 9) AHRI stated
that, after the compliance date of the UEF test procedure, DOE will
require manufacturers to certify UEF values, but for the FTC label,
manufacturers must also have EF-based information. Although DOE had
proposed not to require updated certification reports containing
represented values for UEF until May 1, 2016, AHRI asserted that to
comply with the information requirements of EPCA under section 6293(c),
manufacturers must provide the market with UEF-based information. AHRI
stated that FTC enforces both the EnergyGuide information and general
manufacturer claims regarding their products under the unfair and
deceptive trade practices provisions pursuant to section 6303(c), and
if manufacturers display information not in conformance with Federally-
mandated test procedures, this may be considered a deceptive trade
practice. (AHRI, No. 13 at p. 2)
DOE understands the difficulties created by the timing of both the
uniform efficiency descriptor rulemaking and the present conversion
factor rulemaking for covered water heaters. However, these rulemakings
dealt with matters of significant complexity and necessitated a
substantial amount of testing to ensure the accuracy and validity of
results, as reflected by requests from industry for extended comment
periods and additional DOE testing. Consequently, DOE was not able to
meet the regulatory timeline envisioned by Congress, and as a result,
the Department seeks to alleviate any hardships raised by the current
timeline.
Upon the effective date of the final rule that results from this
rulemaking, certification of compliance with energy conservation
standards will be exclusively in terms of UEF. DOE has tentatively
concluded that there will be three possible paths available to
manufacturers for certifying compliance of basic models of consumer
water heaters that were certified before July 13, 2015: (1) In the year
following the final rule in this rulemaking, convert the energy factor
values 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
from energy factor to uniform energy factor using the applicable
mathematical conversion factor, and then use the converted uniform
energy factors along with the applicable sampling provisions in 10 CFR
part 429 to determine the represented uniform energy 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 paths available to manufacturers for certifying compliance of
basic models of commercial residential-duty water heaters that were
certified before July 13, 2015: (1) In the year following the final
rule in this rulemaking, convert the thermal efficiency and standby
loss values obtained using the test procedure contained in 10 CFR
431.106 of the January 1, 2015 edition of the CFR from thermal
efficiency and standby loss to uniform energy factor using the
applicable mathematical conversion factor, and then use the converted
uniform energy factors along with the applicable sampling provision in
10 CFR part 429 to determine the represented uniform energy 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.
DOE has already issued an enforcement policy not to seek civil
penalties for certification violations during the pendency of this
rulemaking. Under that policy, manufacturers are not held accountable
for submitting certification reports until a conversion factor final
rule is published. DOE intends to extend the certification portion of
that policy for an appropriate time period to allow manufacturers to
certify compliance using the conversion factors. DOE notes that
certification of basic models that were certified prior to July 13,
2015, will only require the application of the appropriate conversion
formula(s) from the final rule and, thus, should not require a
significant amount of time to complete certification. As the test
procedure has been final for more than a year, DOE also expects that
the time to complete certification for basic models introduced after
July 13, 2015, will not be significant. DOE welcomes data from industry
regarding the necessary time to submit such reports.
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
[[Page 59789]]
(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 on a limited basis to determine the represented values
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 energy factor, thermal
efficiency, and standby loss test procedures (as applicable) and the
uniform energy factor test procedure. 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), at 77 FR 49991, 50008-11
(August 20, 2012), and at 81 FR 4469, 4490 (Jan. 26, 2016), 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/sites/default/files/files/Size_Standards_Table.pdf. Consumer water heater
manufacturing is classified under NAICS code 335228--''Other Major
Household Appliance Manufacturing.'' The SBA sets a threshold of 1,000
employees or less for an entity to be considered as a small business.
Commercial water heater manufacturing is classified under NAICS code
333318--``Other 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 11 manufacturers of consumer water heaters that
can be considered small businesses. DOE identified five manufacturers
of ``residential-duty'' commercial water heaters that can be considered
small businesses. Four of the ``residential-duty'' commercial water
heater manufacturers also manufacture consumer water heaters, so the
total number of small water heater manufacturers impacted by this rule
would be 12. DOE's research involved reviewing several industry trade
association membership directories (e.g., AHRI), product databases
(e.g., CCMS, 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 energy
factor test procedure and energy conservation standards, the conversion
factor in this proposed rule would convert the rated values based on
the energy factor test procedure to values based on the uniform energy
factor test procedure. Likewise, 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 previous test procedure to the uniform descriptor
which is based on the UEF test procedure. The energy conservation
standards for commercial water heating equipment will be denominated
using the uniform descriptor.
The conversion factor proposal accomplishes two tasks: (1)
Translating the EF-, TE-, and SL-denominated (as applicable) energy
conservation standards for consumer water heaters and certain
commercial water heaters to being expressed in terms of the metric and
test procedure for uniform energy factor; and (2) providing a limited
conversion factor that manufacturers can use to translate represented
values established for basic models certified prior to July 13, 2015.
This limited conversion is a burden-reducing measure which helps to
ease the transition of the market to the new test procedure and uniform
metric over the one-year period instead of the typical 180 day
timeframe allotted by statute. In addition, as discussed in section
III.F, DOE will implement an enforcement policy that DOE will not seek
civil penalties for the continued manufacture and distribution in
commerce of units of certain basic models that meet certain conditions
(as described in III.F), thereby further reducing any burden on small
business manufacturers. Accordingly, DOE concludes and certifies that
this rule, if finalized, 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 was
approved by OMB under OMB control number 1910-1400, and this
conversion-factor rule does not constitute a significant change to the
requirement. 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
[[Page 59790]]
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 prior efficiency and delivery capacity metrics (and
related energy conservation standard requirements) for consumer and
certain commercial water heaters to the uniform efficiency 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 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 (Public Law 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
[[Page 59791]]
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 (Public Law
93-275), as amended by the Federal Energy Administration Authorization
Act of 1977 (Public Law 95-70). (15 U.S.C. 788; FEAA) Section 32
essentially provides in relevant part 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
supplemental proposed rule, no later than the date provided in the
DATES section at the beginning of this SNOPR. 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
[[Page 59792]]
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. Is DOE's method of applying the regression for electric storage
water heaters with storage volumes at or below 55 gallons in developing
the conversion equation for grid-enabled water heaters appropriate?
2. Is DOE's use of the standard and low-NOX conversion
to calculate the energy conservation standard for consumer gas-fired
storage water heaters less than or equal to 55 gallons, and its
tentative decision not to propose separate standards for ultra-low-
NOX gas-fired storage water heaters appropriate?
3. Are DOE's assumptions for the typical input rating and recovery
efficiency of consumer gas-fired storage water heaters above 55 gallons
appropriate?
4. Is DOE's approach for estimating the recovery efficiency of a
minimally-compliant (i.e., 0.93 EF) electric instantaneous water heater
appropriate?
VI. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this
supplemental 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 August 15, 2016.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy Efficiency, Energy Efficiency and
Renewable Energy.
For the reasons stated in the preamble, DOE proposes 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; 28 U.S.C. 2461 note.
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 energy consumption or other
measure of energy use 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] TP30AU16.039
and, x is the sample mean; n is the number of samples; and
xi is the i\th\ sample;
Or,
(2) The upper 95-percent confidence limit (UCL) of the true mean
divided by 1.10, where
[GRAPHIC] [TIFF OMITTED] TP30AU16.040
[[Page 59793]]
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).
(B) Any represented value of energy efficiency 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] TP30AU16.041
and, x is the sample mean; n is the number of samples; and x
i is the i \th\ sample;
Or,
(2) The lower 95-percent confidence limit (LCL) of the true mean
divided by 0.90, where:
[GRAPHIC] [TIFF OMITTED] TP30AU16.042
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).
(C) 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.
(D) 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.
(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) Determine the represented value for each basic model 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 of paragraph (a)(1); or
(ii) Calculate the uniform energy factor for each test sample by
applying the following mathematical conversion factors to test data
previously obtained through testing according to 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. Represented values of uniform
energy factor, first-hour rating, and maximum GPM rating based on a
calculation using this mathematical conversion factor must be
determined using the applicable sampling provisions in paragraphs
(a)(1)(i) and (a)(1)(ii) of this section.
(A) The applicable mathematical conversion factors are as follows:
------------------------------------------------------------------------
Distinguishing Conversion factor
Product class criteria *
------------------------------------------------------------------------
Consumer Gas-fired Water Heater. Non-Condensing, New FHR = 7.9592 +
Standard and Low 0.8752 x FHRP.
NOX. New UEF = -0.0002
+ 0.9858 x
UEFWHAM.
Non-Condensing, New FHR = 25.0680
Ultra-Low NOX. + 0.6535 x FHRP.
New UEF = 0.0746 +
0.8653 x UEFWHAM.
Condensing........ New FHR = 1.0570 x
FHRP.
New UEF = 0.4242 +
0.4641 x UEFWHAM.
Consumer Oil-fired Water Heater. N/A............... New FHR = 1.1012 x
FHRP.
New UEF = -0.0934
+ 1.1144 x
UEFWHAM.
Consumer Electric Water Heater.. Electric New FHR = 9.2827 +
Resistance. 0.8092 x FHRP.
New UEF = 0.4774 +
0.4740 x UEFWHAM.
Heat Pump......... New FHR = -4.2705
+ 0.9947 x FHRP.
New UEF = 0.1513 +
0.8407 x EF +
0.0043 x DV.
Tabletop Water Heater........... N/A............... New FHR = 41.5127
+ 0.1989 x FHRP.
New UEF = -0.3305
+ 1.3983 x
UEFWHAM.
Instantaneous Gas-fired Water N/A............... New Max GPM =
Heater. 1.1461 x Max
GPMP.
New UEF = 0.1006 +
0.8622 x
UEFmodel.
Instantaneous Electric Water N/A............... New Max GPM =
Heater. 1.1461 x Max
GPMP.
New UEF = 0.9847 x
UEFmodel.
Grid-Enabled Water Heater....... N/A............... New FHR = 9.2827 +
0.8092 x FHRP.
New UEF = 0.4774 +
0.4740 x UEFWHAM.
Residential-Duty Commercial Gas- N/A............... New FHR = -35.8233
fired Water Heater. + 0.4649 x Vr +
160.5089 x Et.
New UEF = -0.0022
+ 1.0002 x UEFrd.
Residential-Duty Commercial Oil- N/A............... New FHR = -35.8233
fired Water Heater. + 0.4649 x Vr +
160.5089 x Et.
New UEF = -0.0022
+ 1.0002 x UEFrd.
[[Page 59794]]
Residential-Duty Commercial N/A............... New Max GPM =
Electric Instantaneous Water 0.0146 + 0.0295 x
Heater. Q.
New UEF = UEFrd,
model.
------------------------------------------------------------------------
* FHRP = prior first-hour rating.
Max GPMP = prior max GPM rating.
Q = nameplate input rate, in kBtu/h.
Et = thermal efficiency rating.
UEFWHAM = the UEF predicted based on the WHAM equation for consumer
storage water heaters, as defined in paragraph (a)(2)(ii)(B) of this
section.
UEFrd = the modified WHAM for residential-duty commercial water heaters,
as defined in paragraph (a)(2)(ii)(B) of this section.
UEFmodel = the UEF predicted based on the analytical model developed by
DOE for consumer instantaneous water heaters, as defined in paragraph
(a)(2)(ii)(B) of this section.
UEFrd model = the UEF predicted based on the analytical model developed
by DOE for residential-duty commercial instantaneous water heaters, as
defined in paragraph (a)(2)(ii)(B) of this section.
DV = drawn volume of water in UEF simulated-use test.
Vr = rated storage volume in gallons.
(B) Calculate UEFWHAM (for consumer storage water
heaters), UEFmodel (for consumer instantaneous water
heaters), UEFrd (for residential-duty commercial storage
water heaters), and UEFrd, model (for residential-duty
commercial electric instantaneous water heaters) as follows:
(1) For consumer storage water heaters:
[GRAPHIC] [TIFF OMITTED] TP30AU16.043
Where a, b, c, and d are coefficients based on the applicable draw
pattern as specified in the table below; EF is the energy factor;
[eta]r is the recovery efficiency in decimal form; and P is
the input rate in Btu/h.
----------------------------------------------------------------------------------------------------------------
Draw pattern a b c d
----------------------------------------------------------------------------------------------------------------
Very Small...................................... 0.250266 57.5 0.039864 67.5
Low............................................. 0.065860 57.5 0.039864 67.5
Medium.......................................... 0.045503 57.5 0.039864 67.5
High............................................ 0.029794 57.5 0.039864 67.5
----------------------------------------------------------------------------------------------------------------
(2) For consumer instantaneous water heaters:
[GRAPHIC] [TIFF OMITTED] TP30AU16.044
Where [eta]r is the recovery efficiency expressed in
decimal form and A is dependent upon the applicable draw pattern and
fuel type as specified in the table below.
------------------------------------------------------------------------
A
Draw pattern -------------------------
Electric Gas
------------------------------------------------------------------------
Very Small.................................... 0.003819 0.026915
Low........................................... 0.001549 0.010917
Medium........................................ 0.001186 0.008362
High.......................................... 0.000785 0.005534
------------------------------------------------------------------------
(3) For residential-duty commercial storage water heaters:
[GRAPHIC] [TIFF OMITTED] TP30AU16.045
Where P is the input rate in Btu/h; Et is the thermal efficiency;
SL is the standby loss in Btu/h; and F and G are coefficients as
specified in the table below based on the applicable draw pattern.
------------------------------------------------------------------------
Draw pattern F G
------------------------------------------------------------------------
Very Small.................................... 0.821429 0.0043520
Low........................................... 0.821429 0.0011450
Medium........................................ 0.821429 0.0007914
High.......................................... 0.821429 0.0005181
------------------------------------------------------------------------
(4) For residential-duty commercial electric instantaneous water
heaters:
[[Page 59795]]
[GRAPHIC] [TIFF OMITTED] TP30AU16.046
Where Et is the thermal efficiency expressed in decimal
form and A is dependent upon the applicable draw pattern, as specified
in the table below.
------------------------------------------------------------------------
Draw pattern A
------------------------------------------------------------------------
Very Small................................................. 0.003819
Low........................................................ 0.001549
Medium..................................................... 0.001186
High....................................................... 0.000785
------------------------------------------------------------------------
(b) Certification reports.
(1) The requirements of 10 CFR 429.12 apply; and
(2) Pursuant to 10 CFR 429.12(b)(13), a certification report must
include the following public product-specific information:
(i) For storage-type water heater basic models previously certified
for energy factor pursuant to Sec. 429.17(a) of the January 1, 2015
edition of the Code of Federal Regulations, and for which uniform
energy factor is calculated pursuant to 10 CFR 429.17(a)(2)(ii): The
energy factor (EF, rounded to the nearest 0.01), the uniform energy
factor (UEF, rounded to the nearest 0.01), the rated storage volume in
gallons (gal, rounded to the nearest 1 gal), the uniform energy factor
test procedure first-hour rating in gallons (gal, rounded to the
nearest 1 gal) as determined under paragraph (a)(2)(ii)(A) of this
section, the previously certified first-hour rating under the energy
factor test procedure in gallons (gal, rounded to the nearest 1 gal),
and the recovery efficiency in percent (%, rounded to the nearest 1%);
(ii) For storage-type water heater basic models rated pursuant to
10 CFR 429.17(a)(1) or 10 CFR 429.17(a)(2)(i): The uniform energy
factor (UEF, rounded to the nearest 0.01), the rated storage volume in
gallons (gal, rounded to the nearest 1 gal), the first-hour rating in
gallons (gal, rounded to the nearest 1 gal), and the recovery
efficiency in percent (%, rounded to the nearest 1%);
(iii) For instantaneous-type water heater basic models previously
certified for energy factor pursuant to Sec. 429.17(a) of the January
1, 2015 edition of the Code of Federal Regulations, and for which
uniform energy factor is calculated pursuant to 10 CFR
429.17(a)(2)(ii): The energy factor (EF, rounded to the nearest 0.01),
the uniform energy factor (UEF. rounded to the nearest 0.01), the rated
storage volume in gallons (gal, rounded to the nearest 1 gal), the
uniform energy factor test procedure maximum gallons per minute (gpm,
rounded to the nearest 0.1 gpm) as determined under-paragraph
(a)(2)(ii)(A) of this section, the previously certified maximum gallons
per minute (gpm, rounded to the nearest 0.1 gpm) under the energy
factor test procedure, and the recovery efficiency in percent (%,
rounded to the nearest 1%); and
(iv) For instantaneous-type water heater basic models rated
pursuant to 10 CFR 429.17(a)(1) or 10 CFR 429.17(a)(2)(i): The uniform
energy factor (UEF, rounded to the nearest 0.01), the rated storage
volume in gallons (gal, rounded to the nearest 1 gal), the maximum
gallons per minute (gpm, rounded to the nearest 0.1 gpm), and the
recovery efficiency in percent (%, rounded to the nearest 1%).(the
uniform energy factor test procedure first-hour rating in gallons (gal,
rounded to the nearest 1 gal) as determined under paragraph
(a)(2)(ii)(A) of this section,
(v) For grid-enabled water heater basic models rated pursuant to 10
CFR 429.17(a)(1) or 10 CFR 429.17(a)(2)(i): The uniform energy factor
(UEF, rounded to the nearest 0.01), the rated storage volume in gallons
(gal, rounded to the nearest 1 gal), the first-hour rating in gallons
(gal, rounded to the nearest 1 gal), and the recovery efficiency in
percent (%, rounded to the nearest 1%), a declaration that the model is
a grid-enabled water heater, whether it is equipped at the point of
manufacture with an activation lock, and whether it bears a permanent
label applied by the manufacturer that advises purchasers and end-users
of the intended and appropriate use of the product.
3. Section 429.17 is further revised, proposed to be effective
(date one year after publication of test procedure 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] TP30AU16.047
and, x is the sample mean; n is the number of samples; and
xi is the i\th\ sample;
Or,
(2) The upper 95-percent confidence limit (UCL) of the true mean
divided by 1.10, where:
[GRAPHIC] [TIFF OMITTED] TP30AU16.048
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).
(B) Any represented value of the uniform 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] TP30AU16.049
and, x is the sample mean; n is the number of samples; and
xi is the i\th\ sample;
Or,
(2) The lower 95-percent confidence limit (LCL) of the true mean
divided by 0.90, where:
[GRAPHIC] [TIFF OMITTED] TP30AU16.050
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).
(C) 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.
(D) Any represented value of first-hour rating or maximum gallons
per
[[Page 59796]]
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: The uniform energy
factor (UEF, rounded to the nearest 0.01), the rated storage volume in
gallons (rounded to the nearest 1 gal), the first-hour rating in
gallons (gal, rounded to the nearest 1 gal), the recovery efficiency in
percent (%, rounded to the nearest 1%);
(ii) For instantaneous-type water heater basic models: The uniform
energy factor (UEF, rounded to the nearest 0.01), the rated storage
volume in gallons (gal, rounded to the nearest 1 gal), the maximum
gallons per minute (gpm, rounded to the nearest 0.1 gpm), the recovery
efficiency in percent (%, rounded to the nearest 1%); and
(iii) For grid-enabled water heater basic models: The uniform
energy factor (UEF, rounded to the nearest 0.01), the rated storage
volume in gallons (gal, rounded to the nearest 1 gal), the first-hour
rating in gallons (gal, rounded to the nearest 1 gal), the recovery
efficiency in percent (%, rounded to the nearest 1%), a declaration
that the model is a grid-enabled water heater, whether it is equipped
at the point of manufacture with an activation lock, and whether it
bears a permanent label applied by the manufacturer that advises
purchasers and end-users of the intended and appropriate use of the
product.
0
4. Section 429.44 is amended by revising paragraph (d) [proposed at 81
FR 28588, 28636 (May 9, 2016)] to read as follows:
Sec. 429.44 Commercial water heating equipment.
* * * * *
(d) Certification reports for residential-duty commercial water
heaters.
(1) The requirements of Sec. 429.12 apply; and
(2) Pursuant to Sec. 429.12(b)(13), a certification report must
include the following public equipment-specific information:
(i) Residential-duty commercial gas-fired and oil-fired storage
water heaters previously certified for thermal efficiency and standby
loss pursuant to 10 CFR 429.44(b) of the January 1, 2015 edition of the
Code of Federal Regulations, and for which uniform energy factor is
calculated pursuant to 10 CFR 429.17(a)(2)(ii): The thermal efficiency
in percent (%), the standby loss in British thermal units per hour
(Btu/h), the uniform energy factor (UEF, rounded to the nearest 0.01),
the rated storage volume in gallons (gal), and the nameplate input rate
in Btu/h.
(ii) Residential-duty commercial gas-fired and oil-fired storage
water heaters rated for uniform energy factor pursuant to 10 CFR
429.17(a)(2)(i): The uniform energy factor (UEF, rounded to the nearest
0.01), the rated storage volume in gallons (rounded to the nearest 1
gal), the first-hour rating in gallons (gal, rounded to the nearest 1
gal), and the recovery efficiency in percent (%, rounded to the nearest
1%).
(iii) Residential-duty commercial electric instantaneous water
heaters previously certified for thermal efficiency and standby loss
pursuant to 10 CFR 429.44(b) of the January 1, 2015 edition of the Code
of Federal Regulations, and for which uniform energy factor is
calculated pursuant to 10 CFR 429.17(a)(2)(ii): The thermal efficiency
in percent (%), the standby loss in British thermal units per hour
(Btu/h), the uniform energy factor (UEF, rounded to the nearest 0.01),
the rated storage volume in gallons (gal), and the nameplate input rate
in kilowatts (kW).
(iv) Residential-duty commercial electric instantaneous water
heaters rated for uniform energy factor pursuant to 10 CFR
429.17(a)(2)(i): The uniform energy factor (UEF, rounded to the nearest
0.01), the rated storage volume in gallons (gal, rounded to the nearest
1 gal), the maximum gallons per minute (gpm, rounded to the nearest 0.1
gpm), and the recovery efficiency in percent (%, rounded to the nearest
1%)).
* * * * *
0
5. Section 429.44 is further amended, proposed to be effective (date
one year after publication of test procedure final rule), by revising
paragraph (d)(2) to read as follows:
Sec. 429.44 Commercial water heating equipment.
* * * * *
(d) * * *
(2) Pursuant to Sec. 429.12(b)(13), a certification report for
equipment must include the following public equipment-specific
information:
(i) Residential-duty commercial gas-fired and oil-fired storage
water heaters: The uniform energy factor (UEF, rounded to the nearest
0.01), the rated storage volume in gallons (gal, rounded to the nearest
1 gal), the first-hour rating in gallons (gal, rounded to the nearest 1
gal), and the recovery efficiency in percent (%, rounded to the nearest
1%).
(ii) Residential-duty commercial electric instantaneous water
heaters: The uniform energy factor (UEF, rounded to the nearest 0.01),
the rated storage volume in gallons (gal, rounded to the nearest 1
gal), the maximum gallons per minute (gpm, rounded to the nearest 0.1
gpm), and the recovery efficiency in percent (%, rounded to the nearest
1%).
* * * * *
0
6. Section 429.134 is revised by amending paragraph (d)(2) to read as
follows:
Sec. 429.134 Product-specific enforcement provisions.
* * * * *
(d) * * *
(2) Verification of rated storage volume. The storage volume of the
basic model will be measured pursuant to the test requirements of
appendix E to subpart B of 10 CFR part 430 for each unit tested. The
mean of the measured values will be compared to the rated storage
volume as certified by the manufacturer. The rated value will be
considered valid only if the measurement is within two percent of the
certified rating.
(i) If the rated storage volume is found to be within 2 percent of
the mean of the measured value of storage volume, then the rated value
will be used as the basis for calculation of the required uniform
energy factor for the basic model.
(ii) If the rated storage volume is found to vary more than 2
percent from the mean of the measured values, then the mean of the
measured values will be used as the basis for calculation of the
required uniform energy factor for the basic model.
* * * * *
PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS
0
7. 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
8. 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 is calculated as--
[[Page 59797]]
(A) For a gas-fired or oil-fired 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. Round the resulting
product to the nearest dollar per year.
(B) For an electric water heater, the product of the annual energy
consumption, determined according to section 6.1.8 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. Round the resulting
quotient to the nearest dollar per year.
(ii) For an individual unit, determine the tested energy factor in
accordance with 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, and round the value to the nearest 0.01.
(2) For water heaters tested using uniform energy factor:
(i) The estimated annual operating cost is calculated as:
(A) For a gas-fired or oil-fired water heater, the sum of: The
product of the annual gas or oil energy consumption, determined
according to section 6.3.9 or 6.4.6 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 6.3.8 or 6.4.5 of appendix E of this subpart, times the
representative average unit cost of electricity in dollars per
kilowatt-hour as provided by the Secretary. Round the resulting sum to
the nearest dollar per year.
(B) For an electric water heater, the product of the annual energy
consumption, determined according to section 6.3.7 or 6.4.4 of appendix
E of this subpart, times the representative average unit cost of
electricity in dollars per kilowatt-hour as provided by the Secretary.
Round the resulting product to the nearest dollar per year.
(ii) For an individual unit, determine the tested uniform energy
factor in accordance with section 6.3.6 or 6.4.3 of appendix E of this
subpart, and round the value to the nearest 0.01.
* * * * *
0
9. Section 430.23 paragraph (e) is further revised, proposed to be
effective (date one year after publication of test procedure final
rule), to read as follows:
Sec. 430.23 Test procedures for the measurement of energy and water
consumption.
* * * * *
(e) Water Heaters.
(1) The estimated annual operating cost is calculated as:
(i) For a gas-fired or oil-fired water heater, the sum of: The
product of the annual gas or oil energy consumption, determined
according to section 6.3.9 or 6.4.6 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 6.3.8 or 6.4.5 of appendix E of this subpart, times the
representative average unit cost of electricity in dollars per
kilowatt-hour as provided by the Secretary. Round the resulting sum to
the nearest dollar per year.
(ii) For an electric water heater, the product of the annual energy
consumption, determined according to section 6.3.7 or 6.4.4 of appendix
E of this subpart, times the representative average unit cost of
electricity in dollars per kilowatt-hour as provided by the Secretary.
Round the resulting product to the nearest dollar per year.
(2) For an individual unit, determine the tested uniform energy
factor in accordance with section 6.3.6 or 6.4.3 of appendix E of this
subpart, and round the value to the nearest 0.01.
* * * * *
0
10. 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 uniform energy factor of water heaters shall
not be less than the following:
----------------------------------------------------------------------------------------------------------------
Rated storage volume and
Product class input rating (if Draw pattern Uniform energy factor
applicable)
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage Water Heater.... <20 gal................... Very Small........... 0.2471-(0.0002 x Vr).
Low.................. 0.5132-(0.0012 x Vr).
Medium............... 0.5827-(0.0015 x Vr).
High................. 0.6507-(0.0019 x Vr).
>=20 gal and <=55 gal..... Very Small........... 0.3456-(0.0020 x Vr).
Low.................. 0.5982-(0.0019 x Vr).
Medium............... 0.6483-(0.0017 x Vr).
High................. 0.6920-(0.0013 x Vr).
>55 gal and <=100 gal..... Very Small........... 0.6470-(0.0006 x Vr).
Low.................. 0.7689-(0.0005 x Vr).
Medium............... 0.7897-(0.0004 x Vr).
High................. 0.8072-(0.0003 x Vr).
>100 gal.................. Very Small........... 0.1755-(0.0006 x Vr).
Low.................. 0.4671-(0.0015 x Vr).
Medium............... 0.5719-(0.0018 x Vr).
High................. 0.6916-(0.0022 x Vr).
Oil-fired Storage Water Heater.... <=50 gal.................. Very Small........... 0.1822-(-0.0001 x Vr).
Low.................. 0.5313-(0.0014 x Vr).
Medium............... 0.6316-(0.0020 x Vr).
High................. 0.7334-(0.0028 x Vr).
>50 gal................... Very Small........... 0.1068-(0.0007 x Vr).
Low.................. 0.4190-(0.0017 x Vr).
Medium............... 0.5255-(0.0021 x Vr).
High................. 0.6438-(0.0025 x Vr).
Electric Storage Water Heaters.... <20 gal................... Very Small........... 0.7836-(0.0013 x Vr).
Low.................. 0.8939-(0.0008 x Vr).
Medium............... 0.9112-(0.0007 x Vr).
High................. 0.9255-(0.0006 x Vr).
>=20 gal and <=55 gal..... Very Small........... 0.8808-(0.0008 x Vr).
Low.................. 0.9254-(0.0003 x Vr).
[[Page 59798]]
Medium............... 0.9307-(0.0002 x Vr).
High................. 0.9349-(0.0001 x Vr).
>55 gal and <=120 gal..... Very Small........... 1.9236-(0.0011 x Vr).
Low.................. 2.0440-(0.0011 x Vr).
Medium............... 2.1171-(0.0011 x Vr).
High................. 2.2418-(0.0011 x Vr).
>120 gal.................. Very Small........... 0.6802-(0.0003 x Vr).
Low.................. 0.8620-(0.0006 x Vr).
Medium............... 0.9042-(0.0007 x Vr).
High................. 0.9437-(0.0007 x Vr).
Tabletop Water Heater............. All....................... Very Small........... 0.6323-(0.0058 x Vr).
Low.................. 0.9188-(0.0031 x Vr).
Medium............... 0.9577-(0.0023 x Vr).
High................. 0.9884-(0.0016 x Vr).
Instantaneous Gas-fired Water <2 gal and >50,000 Btu/h.. Very Small........... 0.7964-(0.0000 x Vr).
Heater.
Low.................. 0.8055-(0.0000 x Vr).
Medium............... 0.8070-(0.0000 x Vr).
High................. 0.8086-(0.0000 x Vr).
>=2 gal or <=50,000 Btu/h. Very Small........... 0.3013-(0.0023 x Vr).
Low.................. 0.5421-(0.0024 x Vr).
Medium............... 0.5942-(0.0021 x Vr).
High................. 0.6415-(0.0017 x Vr).
Instantaneous Oil-fired Water All....................... Very Small........... 0.1430-(0.0015 x Vr).
Heater.
Low.................. 0.4455-(0.0023 x Vr).
Medium............... 0.5339-(0.0023 x Vr).
High................. 0.6245-(0.0021 x Vr).
Instantaneous Electric Water All....................... Very Small........... 0.9161-(0.0039 x Vr).
Heater.
Low.................. 0.9159-(0.0009 x Vr).
Medium............... 0.9160-(0.0005 x Vr).
High................. 0.9161-(0.0003 x Vr).
Grid-Enabled Water Heater......... >75 gal................... Very Small........... 1.0136-(0.0028 x Vr).
Low.................. 0.9984-(0.0014 x Vr).
Medium............... 0.9853-(0.0010 x Vr).
High................. 0.9720-(0.0007 x Vr).
----------------------------------------------------------------------------------------------------------------
*Vr is the rated storage volume in gallons.
* * * * *
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
11. The authority citation for part 431 continues to read as follows:
Authority: 42 U.S.C. 6291-6317. 28 U.S.C. 2461 note.
0
12. Section 431.110 is amended by revising paragraph (d) [proposed at
81 FR 34440. 34536-34537 (May 31, 2016)] to read as follows:
Sec. 431.110 Energy conservation standards and their effective dates.
* * * * *
(d) Each residential-duty commercial water heater manufactured
prior to (date 3 years after publication in the Federal Register of the
final rule establishing amended energy conservation standards for
commercial water-heating equipment) must meet the applicable energy
conservation standard level(s) as follows:
----------------------------------------------------------------------------------------------------------------
Product class Specifications \a\ Draw pattern Uniform energy factor \b\
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage.............. >75 kBtu/hr and <=105 Very Small....... 0.2670 - (0.0009 x Vr)
kBtu/hr and <=120 gal.
Low.............. 0.5356 - (0.0012 x Vr)
Medium........... 0.5996 - (0.0011 x Vr)
High............. 0.6592 - (0.0009 x Vr)
Oil-fired Storage.............. >105 kBtu/hr and <=140 Very Small....... 0.2932 - (0.0015 x Vr)
kBtu/hr and <=120 gal.
Low.............. 0.5596 - (0.0018 x Vr)
Medium........... 0.6194 - (0.0016 x Vr)
High............. 0.6740 - (0.0013 x Vr)
Electric Instantaneous......... >12 kW and <=58.6 kW and Very Small....... 0.80
<=2 gal.
Low.............. 0.80
Medium........... 0.80
High............. 0.80
----------------------------------------------------------------------------------------------------------------
\a\ Additionally, to be classified as a residential-duty commercial water heater, a commercial water heater must
meet the following conditions: (1) If the water heater requires electricity, it must use a single-phase
external power supply; and (2) the water heater must not be designed to heat water to temperatures greater
than 180 [deg]F.
\b\ Vr is the rated storage volume in gallons.
* * * * *
[FR Doc. 2016-20097 Filed 8-29-16; 8:45 am]
BILLING CODE 6450-01-P
