Energy Conservation Program for Consumer Products and Certain Commercial and Industrial Equipment: Test Procedures for Residential and Commercial Water Heaters, 66201-66248 [2013-26268]
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Vol. 78
Monday,
No. 213
November 4, 2013
Part IV
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 Residential and
Commercial Water Heaters; Proposed Rule
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Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
DEPARTMENT OF ENERGY
10 CFR Parts 429, 430 and 431
[Docket Number EERE–2011–BT–TP–0042]
RIN 1904–AC53
Energy Conservation Program for
Consumer Products and Certain
Commercial and Industrial Equipment:
Test Procedures for Residential and
Commercial Water Heaters
Office of Energy Efficiency and
Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking
and announcement of public meeting.
AGENCY:
The U.S. Department of
Energy (DOE) proposes to revise its test
procedure for residential water heaters
and certain commercial water heaters
established under the Energy Policy and
Conservation Act. This rulemaking will
fulfill DOE’s statutory obligation for
residential and certain commercial
water heaters to review its test
procedure for covered products and
equipment at least once every seven
years. In addition, this rulemaking will
satisfy DOE’s statutory obligation to
develop a uniform efficiency descriptor
for residential and commercial water
heaters. The proposed test method
would apply the same efficiency
descriptor to all residential and certain
commercial water heaters, and it would
extend coverage to eliminate certain
gaps in the current residential test
procedure, update the simulated-usetest draw pattern, and update the water
delivery temperature requirement. DOE
is also announcing a public meeting to
discuss and receive comments on issues
presented in this test procedure
rulemaking.
DATES:
Comments: DOE will accept
comments, data, and information
regarding this notice of proposed
rulemaking (NOPR) before and after the
public meeting, but no later than
January 21, 2014. See section V, ‘‘Public
Participation,’’ for details.
Meeting: DOE will hold a public
meeting on December 6, 2013 from 9:00
a.m. to 4:00 p.m., in Washington, DC.
The meeting will also be broadcast as a
webinar. See section V, ‘‘Public
Participation,’’ for webinar registration
information, participant instructions,
and information about the capabilities
available to webinar participants.
ADDRESSES: The public meeting will be
held at the U.S. Department of Energy,
Forrestal Building, Room 8E–089, 1000
Independence Avenue SW.,
Washington, DC 20585. To attend,
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SUMMARY:
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please notify Ms. Brenda Edwards at
(202) 586–2945. Please note that foreign
nationals visiting DOE Headquarters are
subject to advance security screening
procedures. Any foreign national
wishing to participate in the meeting
should advise DOE as soon as possible
by contacting Ms. Edwards at the phone
number above to initiate the necessary
procedures. Please also note that any
person wishing to bring a laptop
computer into the Forrestal Building
will be required to obtain a property
pass. Visitors should avoid bringing
laptops, or allow an extra 45 minutes.
Persons may also attend the public
meeting via webinar. For more
information, refer to section V, ‘‘Public
Participation,’’ near the end of this
notice of proposed rulemaking.
Interested persons are encouraged to
submit comments using the Federal
eRulemaking Portal at
www.regulations.gov. Follow the
instructions for submitting comments.
Alternatively, interested persons may
submit comments, identified by docket
number EERE–2011–BT–TP–0042 and/
or RIN 1904–AC53, by any of the
following methods:
• Email: HeatingProducts-2011-TP0042@ee.doe.gov. Include EERE–2011–
BT–TP–0042 and/or RIN 1904–AC53 in
the subject line of the message. Submit
electronic comments in WordPerfect,
Microsoft Word, PDF, or ASCII file
format, and avoid the use of special
characters or any form of encryption.
• Postal Mail: Ms. Brenda Edwards,
U.S. Department of Energy, Building
Technologies Office, Mailstop EE–2J,
1000 Independence Avenue SW.,
Washington, DC 20585–0121. If
possible, please submit all items on a
compact disc (CD), in which case it is
not necessary to include printed copies.
• Hand Delivery/Courier: Ms. Brenda
Edwards, U.S. Department of Energy,
Building Technologies Office, 950
L’Enfant Plaza SW., 6th Floor,
Washington, DC 20024. Telephone:
(202) 586–2945. If possible, please
submit all items on a CD, in which case
it is not necessary to include printed
copies.
Instructions: All submissions received
must include the agency name and
docket number and/or RIN for this
rulemaking. No telefacsimilies (faxes)
will be accepted. For detailed
instructions on submitting comments
and additional information on the
rulemaking process, see section V of this
document (Public Participation).
Docket: The docket is available for
review at including Federal Register
notices, public meeting attendee lists
and transcripts, comments, and other
supporting documents/materials. All
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documents in the docket are listed in
the index. However, not all documents
listed in the index may be publicly
available, such as information that is
exempt from public disclosure.
A link to the docket Web page can be
found at: https://www.regulations.gov/
#!docketDetail;D=EERE-2011-BT-TP0042. This Web page contains a link to
the docket for this notice of proposed
rulemaking on the site. The Web page
contains simple instructions on how to
access all documents, including public
comments, in the docket. See section V,
‘‘Public Participation,’’ for information
on how to submit comments through
www.regulations.gov.
For information on how to submit a
comment, review other public
comments and the docket, or participate
in the public meeting, contact Ms.
Brenda Edwards at (202) 586–2945 or by
email: Brenda.Edwards@ee.doe.gov.
FOR FURTHER INFORMATION CONTACT: Ms.
Ashley Armstrong, U.S. Department of
Energy, Office of Energy Efficiency and
Renewable Energy, Building
Technologies Office, EE–2J, 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–71, 1000 Independence Avenue
SW., Washington, DC 20585–0121.
Telephone: (202) 586–9507. Email:
Eric.Stas@hq.doe.gov.
For information on how to submit or
review public comments, contact Ms.
Brenda Edwards, U.S. Department of
Energy, Office of Energy Efficiency and
Renewable Energy, Building
Technologies Office, EE–2J, 1000
Independence Avenue SW.,
Washington, DC 20585–0121.
Telephone: (202) 586–2945. Email:
Brenda.Edwards@ee.doe.gov.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Authority and Background
II. Summary of the Notice of Proposed
Rulemaking
III. Discussion
A. Scope
1. Coverage Range of Uniform Metric and
Test Procedure
2. Storage Capacity Limits
3. Input Capacity Limits
4. Electric Instantaneous Water Heaters
B. Uniform Efficiency Descriptor
C. Draw Pattern
D. Instrumentation
E. Discrete Performance Tests
F. Test Conditions
1. Water Delivery Temperature
2. Ambient Temperature and Relative
Humidity
3. Laboratory Airflow
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G. Annual Energy Consumption
Calculation
H. Conversion of Existing Energy Factor
Ratings
I. Other Issues
J. Certification, Compliance, and
Enforcement Issues
K. Reference Standards
L. Compliance With Other EPCA
Requirements
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility
Act
C. Review Under the Paperwork Reduction
Act of 1995
D. Review Under the National
Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates
Reform Act of 1995
H. Review Under the Treasury and General
Government Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General
Government Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal
Energy Administration Act of 1974
V. Public Participation
A. Attendance at the Public Meeting
B. Procedure for Submitting Requests to
Speak and Prepared General Statements
for Distribution
C. Conduct of the Public Meeting
D. Submission of Comments
E. 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
residential water heaters, one subject of
today’s notice of proposed rulemaking.
(42 U.S.C. 6292(a)(4)) Title III, Part C 3
of EPCA, Public Law 94–163 (42 U.S.C.
6311–6317, as codified), added by
Public Law 95–619, Title IV, Sec. 441(a),
established the Energy Conservation
Program for Certain Industrial
Equipment, which includes the
commercial water-heating equipment
that is another subject of this
rulemaking. (42 U.S.C. 6311(1)(K))
Under EPCA, energy conservation
programs generally consist of four parts:
(1) Testing; (2) labeling; (3) establishing
1 For editorial reasons, upon codification in the
U.S. Code, Part B was redesignated as Part A.
2 All references to EPCA in this document refer
to the statute as amended through the American
Energy Manufacturing Technical Corrections Act
(AEMTCA), Public Law 112–210 (Dec. 18, 2012).
3 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
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Federal energy conservation standards;
and (4) certification and enforcement
procedures. The testing requirements
consist of test procedures that
manufacturers of covered products and
equipment must use as both the basis
for certifying to DOE that their products
and equipment comply with the
applicable energy conservation
standards adopted pursuant to 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 requirements to determine
whether the products comply with any
relevant standards promulgated under
EPCA. (42 U.S.C. 6295(s))
Under 42 U.S.C. 6293, EPCA sets forth
the criteria and procedures that DOE
must follow when prescribing or
amending test procedures for residential
water heaters. EPCA provides, in
relevant part, that any test procedures
prescribed or amended under this
section must be reasonably designed to
produce test results which measure
energy efficiency, energy use, or
estimated annual operating cost of a
covered product during a representative
average use cycle or period of use, and
must not be unduly burdensome to
conduct. (42 U.S.C. 6293(b)(3)) In
addition, if DOE determines that a test
procedure amendment is warranted, it
must publish proposed test procedures
and offer the public an opportunity to
present oral and written comments on
them. (42 U.S.C. 6293(b)(2))
For commercial water heaters, EPCA
requires that if the test procedure
referenced in the American Society of
Heating, Refrigerating, and AirConditioning Engineers (ASHRAE)
Standard 90.1 is updated, DOE must
update its test procedure to be
consistent with the amended test
procedure in ASHRAE Standard 90.1,
‘‘Energy Standard for Buildings Except
Low-Rise Residential Buildings,’’ unless
DOE determines by rule published in
the Federal Register and supported by
clear and convincing evidence, that the
amended test procedure is not
reasonably designed to produce test
results which reflect the energy
efficiency, energy use, or estimated
operating costs of that type of ASHRAE
equipment during a representative
average use cycle. In addition, DOE
must determine that the amended test
procedure is not unduly burdensome to
conduct. (42 U.S.C. 6314(a)(2) and (4))
In any rulemaking to amend a test
procedure, DOE must determine the
extent to which the proposed test
procedure would alter the product’s
measured energy efficiency. (42 U.S.C.
6293(e)(1)) If DOE determines that the
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amended test procedure would alter the
measured efficiency of a covered
product, DOE must amend the
applicable energy conservation standard
accordingly. (42 U.S.C. 6293(e)(2))
Further, the Energy Independence and
Security Act of 2007 (EISA 2007)
amended EPCA to require that at least
once every 7 years, DOE must review
test procedures for all covered products
and either amend test procedures (if the
Secretary determines that amended test
procedures would more accurately or
fully comply with the requirements of
42 U.S.C. 6293(b)(3) for residential
products or 42 U.S.C. 6314(a)(2)-(3) for
commercial equipment) or publish
notice in the Federal Register of any
determination not to amend a test
procedure. (42 U.S.C. 6293(b)(1)(A); 42
U.S.C. 6314(a)(1)(A)) Under this
requirement, DOE must review the test
procedures for residential water heaters
not later than December 19, 2014 (i.e.,
7 years after the enactment of EISA
2007), and DOE must review the test
procedures for commercial water
heaters not later than May 16, 2019 (i.e.,
7 years after the last final rule for
commercial water heater test
procedures 4). Thus, the final rule
resulting from this rulemaking will
satisfy the requirement to review the
test procedures for residential and
certain commercial water heaters every
seven years.
DOE’s test procedure for residential
water heaters is found in the Code of
Federal Regulations (CFR) at 10 CFR
430.23(e) and 10 CFR part 430, subpart
B, appendix E. The test procedure
includes provisions for determining the
energy efficiency (energy factor (EF)), as
well as the annual energy consumption
of these products. DOE’s test procedure
for commercial water heaters is found at
10 CFR 431.106; that test procedure
incorporates by reference American
National Standards Institute (ANSI)
Z21.10.3, Gas Water Heaters—Volume
III, Storage Water Heaters With Input
Ratings Above 75,000 Btu Per Hour,
Circulating and Instantaneous, and
provides a method for determining the
thermal efficiency and standby loss of
this equipment.
In addition to the test procedure
review provision discussed above, EISA
2007 also amended EPCA to require
DOE to amend its test procedures for all
covered residential products to include
measurement of standby mode and off
mode energy consumption. (42 U.S.C.
6295(gg)(2)(A)) Consequently, DOE
recently completed a rulemaking to
4 On May 16, 2012, DOE published a final rule in
the Federal Register amending the test procedures
for commercial water heaters. 77 FR 28928.
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consider amending its test procedure for
residential water heaters to include
provisions for measuring the standby
mode and off mode energy consumption
of those products. Pursuant to the
requirements of EPCA, DOE published a
notice of proposed rulemaking (NOPR)
in the Federal Register on August 30,
2010, for three different residential
heating products (water heaters, pool
heaters, and direct heating equipment)
related to standby mode and off mode
energy consumption, but the NOPR
proposed no amendments to the DOE
test procedure for residential water
heaters because DOE tentatively
concluded that standby mode and off
mode energy consumption was already
accounted for in the existing DOE test
method.5 75 FR 52892, 52895.
Subsequently, DOE published a final
rule in the Federal Register on
December 17, 2012, which affirmed its
conclusion that no changes were needed
to the existing test procedure for
residential water heaters. 77 FR 74559,
74561–74562. However, that rulemaking
was limited to consideration of test
procedure amendments to address the
above-referenced standby mode and off
mode requirements; it did not address
several other potential issues in DOE’s
existing test procedure for residential
water heaters. DOE addresses these
issues in today’s NOPR.
On October 12, 2011, DOE published
in the Federal Register a request for
information (RFI) that identified and
requested comment on a number of
issues regarding the test procedures for
residential water heaters. 76 FR 63211.
DOE accepted comments and
information on the RFI until November
28, 2011, and considered all feedback
received when developing the proposals
contained in this notice. Each of the
issues raised in the RFI is discussed in
detail in section III, along with
comments received on the issues and
DOE’s responses. In addition, several
topics not addressed in the RFI but
brought up by interested parties in their
comments are discussed in section III of
this NOPR.
On December 18, 2012, the American
Energy Manufacturing Technical
Corrections Act (AEMTCA), Public Law
112–210, was signed into law. In
relevant part, it amended EPCA to
require that DOE publish a final rule
establishing a uniform efficiency
descriptor and accompanying test
methods for covered residential water
heaters and commercial water heating
equipment within one year of the
5 For more information, please visit DOE’s Web
site at: https://www1.eere.energy.gov/buildings/
appliance_standards/residential/waterheaters.html.
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enactment of AEMTCA. (42 U.S.C.
6295(e)(5)(B)) The final rule must
replace the current energy factor,
thermal efficiency, and standby loss
metrics with a uniform efficiency
descriptor. (42 U.S.C. 6295(e)(5)(C))
AEMTCA requires that, beginning one
year after the date of publication of
DOE’s final rule establishing the
uniform descriptor, the efficiency
standards for covered water heaters
must be denominated according to the
uniform efficiency descriptor
established in the final rule (42 U.S.C.
6295(e)(5)(D)), and that DOE must
develop a mathematical conversion
factor for converting the measurement of
efficiency for covered water heaters
from the test procedures and metrics
currently in effect to the new uniform
energy descriptor. (42 U.S.C.
6295(e)(5)(E)(i)–(ii)) After the effective
date of the final rule, covered water
heaters shall be considered to comply
with the final rule and with any revised
labeling requirements established by the
Federal Trade Commission (FTC) to
carry out the final rule, if the covered
water heater was manufactured prior to
the effective date of the final rule and
complies with the efficiency standards
and labeling requirements in effect prior
to the final rule. (42 U.S.C.
6295(e)(5)(K))
AEMTCA also requires that the
uniform efficiency descriptor and
accompanying test method apply, to the
maximum extent practicable, to all
water-heating technologies currently in
use and to future water-heating
technologies. (42 U.S.C. 6295(e)(5)(H))
AEMTCA allows DOE to provide an
exclusion from the uniform efficiency
descriptor for specific categories of
otherwise covered water heaters that do
not have residential uses, that can be
clearly described, and that are
effectively rated using the current
thermal efficiency and standby loss
descriptors. (42 U.S.C. 6295(e)(5)(F))
AEMTCA outlines DOE’s various
options for establishing a new uniform
efficiency descriptor for water heaters.
The options that AEMTCA provides to
DOE include: (1) A revised version of
the energy factor descriptor currently in
use; (2) the thermal efficiency and
standby loss descriptors currently in
use; (3) a revised version of the thermal
efficiency and standby loss descriptors;
(4) a hybrid of descriptors; or (5) a new
approach. (42 U.S.C. 6295(e)(5)(G))
Lastly, AEMTCA requires that DOE
invite stakeholders to participate in the
rulemaking process, and that DOE
contract with the National Institute of
Standards and Technology (NIST), as
necessary, to conduct testing and
simulation of alternative descriptors
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identified for consideration. (42 U.S.C.
6295(e)(5)(I)–(J))
DOE published an RFI on January 11,
2013 requesting input on the various
issues pertaining to water heaters
discussed in AEMTCA. 78 FR 2340. The
feedback received from stakeholders
was taken into consideration and is
discussed further in section III of this
NOPR.
II. Summary of the Notice of Proposed
Rulemaking
In this NOPR, DOE proposes to
modify the current test procedures for
residential water heaters and certain
commercial water heaters. The proposed
amendments would modify the test
procedure to be more representative of
conditions encountered in the field
(including modifications to both the test
conditions and the draw patterns) and
expand the scope of the test procedure
to apply to certain commercial water
heaters and certain residential water
heaters that are currently not covered by
the test procedure. The following
paragraphs summarize these proposed
changes.
DOE proposes to modify the test
procedure for water heaters to establish
a uniform descriptor that can be applied
to: (1) All residential water heaters
(including certain residential water
heaters that are covered products under
EPCA’s definition of ‘‘water heater’’ at
42 U.S.C. 6291(27), but that are not
covered under the existing test method);
and (2) to certain commercial water
heaters that have residential
applications. This includes the
proposed establishment of test
procedure provisions that are applicable
to water heaters with storage volumes
between 2 gallons (7.6 L) and 20 gallons
(76 L), and the proposed creation of a
definition for ‘‘electric instantaneous
water heater.’’ In addition, DOE
proposes to establish a new equipment
class of commercial water heaters and
corresponding definition for ‘‘light
commercial water heater.’’ DOE
proposes to require water heaters that
would be classified as ‘‘light
commercial’’ to be tested using the test
procedure for the uniform efficiency
descriptor being proposed in this NOPR.
DOE is also proposing the use of
multiple draw patterns for testing water
heaters, with certain draw patterns
prescribed as a function of equipment
capacity. Further, DOE proposes
updates to the water heater draw pattern
to be more reflective of actual field
usage based on recent field test data.
Lastly, DOE is modifying the water
delivery temperature requirement to
better reflect conditions as seen in
typical installations in the field.
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III. Discussion
In response to the October 2011 RFI,
DOE received 19 written comments
related to water heaters from the
following interested parties: Pacific Gas
and Electric Company (PGE), Applied
Energy Technology (AET), Davis Energy
Group, American Council for an EnergyEfficient Economy (ACEEE), Southern
California Edison (SCE), National
Renewable Energy Laboratory (NREL),
Natural Resources Canada (NRCan),
Natural Resources Defense Council
(NRDC), Air-Conditioning, Heating, and
Refrigeration Institute (AHRI),
Northwest Energy Efficiency Alliance
(NEEA), American Gas Association
(AGA), National Propane Gas
Association (NPGA), A.O. Smith
Corporation (AO Smith), Bradford
White Corporation (Bradford White),
Lochinvar, Stone Mountain
Technologies, Bosch Thermotechnology
Corp. (Bosch), General Electric
Company (GE), and ASHRAE.
In response to the January 2013 RFI,
DOE received 18 written comments
from the following interested parties:
NREL, Bradford White, AGA, NPGA,
AHRI, AO Smith, joint efficiency
advocates (joint comment),6 GE, NEEA,
Rheem Manufacturing Company
(Rheem), American Public Gas
Association (APGA), Edison Electric
Institute (EEI), Heat Transfer Products
Inc. (HTP), Natural Resources Canada
(NRCan), Seisco International Limited
(Seisco), Aquarensics, and two separate
comments from the University of
Houston—Clear Lake (UHCL1, UHCL2).
These interested parties commented
on a range of issues, including those
identified by DOE in the October 2011
RFI and the January 2013 RFI, as well
as several other pertinent issues. The
issues on which DOE received
comment, as well as DOE’s response to
those comments and the resulting
proposed changes to the test procedures
for water heaters, are discussed in the
subsections immediately below.
A. Scope
DOE’s test procedures for residential
water heaters codified at 10 CFR
430.23(e) and 10 CFR part 430, subpart
B, appendix E address gas-fired, electric,
and oil-fired storage-type (i.e., storage
volume not less than 20 gallons (76 L))
and gas-fired and electric instantaneoustype (i.e., storage volume less than 2
gallons (7.6 L)) water heaters. However,
6 ACEEE submitted a joint comment on behalf of
ACEEE, the Appliance Standards Awareness Project
(ASAP), the National Consumer Law Center
(NCLC), the Natural Resources Defense Council
(NRDC), the Northeast Energy Efficiency
Partnerships (NEEP), and the Northwest Power and
Conservation Council (NPCC).
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the DOE test procedure does not define
‘‘electric instantaneous water heater.’’ In
addition, it does not address the
following types of products: (1) Gasfired water heaters that have a storage
volume at or above 2 gallons and less
than 20 gallons (76 L); (2) electric
storage water heaters with storage
volume less than 20 gallons (76 L); and
(3) storage water heaters with very large
storage capacities, including oil-fired
water heaters with storage volumes
greater than 50 gallons (190 L), gas-fired
water heaters with storage volumes
above 100 gallons (380 L), and electric
water heaters with storage volumes
above 120 gallons (450 L). As discussed
in the following sections, DOE proposes
to expand the scope of coverage of its
test method so that it is applicable to all
products that meet the definition of
residential water heater, including those
products listed above which are
currently not addressed by the existing
DOE test method. DOE is also revising
10 CFR 430.32(d) to clarify the
applicability of the existing standards
with respect to the expanded test
procedure scope.
DOE’s test procedures for commercial
water heaters are found at 10 CFR
431.106. In terms of capacity, the
procedures for commercial water
heaters cover storage water heaters with
an input rating up to 4,000 British
thermal units (Btu) per hour (Btu/h) per
gallon of stored water, instantaneous
water heaters with input ratings not less
than 4,000 Btu/h per gallon of stored
water, and hot water supply boilers with
input ratings from 300,000 Btu/h to
12,500,000 Btu/h and of at least 4,000
Btu/h per gallon of stored water. Units
using natural gas, oil, or electricity are
covered by these test methods.
EPCA includes definitions for both
residential and commercial water
heaters that set the scope of DOE’s
authority for these products. (42 U.S.C.
6291(27); 42 U.S.C. 6311(12)) As
required by AEMTCA, DOE proposes to
create a uniform metric and test method
for all covered water heaters,7 regardless
of whether a particular water heater falls
under the scope of residential water
heaters or commercial water heaters as
defined in EPCA. In doing so, DOE also
proposes to expand the scope of the test
procedure to include definitions and
test methods for the types of products
7 As provided by 42 U.S.C. 6295(e)(5)(F), DOE is
proposing to allow for the exclusion from the
uniform efficiency descriptor of certain commercial
water heaters that do not have a residential use and
can be clearly described in the final rule and are
effectively rated using the thermal efficiency and
standby loss descriptors. The water heaters that
DOE is proposing to exclude are discussed further
in section III.A.1.
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noted above that are not covered by
DOE’s residential test procedure. DOE
identified these topics as issues for
comment in the October 2011 RFI and
the January 2013 RFI. 76 FR 63211,
63212–63213 (Oct. 12, 2011); 78 FR
2340, 2344–2346 (Jan. 11, 2013).
1. Coverage Range of Uniform Metric
and Test Procedure
In the January 2013 RFI, DOE
requested comment on whether the
uniform efficiency descriptor required
by AEMTCA should apply to all types
of residential and commercial water
heaters covered by EPCA, in addition to
hot water supply boilers and unfired hot
water storage tanks. In requesting
comment, DOE acknowledged that
AEMTCA provides for the possibility of
an exclusion for certain water heaters
from the uniform efficiency metric and
accompanying test method. 78 FR 2340,
2345–46 (Jan. 11, 2013).
DOE received 7 comments that
opposed DOE’s tentative interpretation
that AEMTCA requires the uniform
descriptor to apply to all types of
residential and commercial water
heaters and indicated that DOE should
utilize the statutory provision
permitting an exclusion for any specific
category of otherwise covered water
heaters that do not have a residential
use. (Bradford White, No. 30 at p. 2;
AHRI, No. 33 at p. 1; AO Smith, No. 34
at p. 1; Joint comment, No. 35 at p. 2;
NEEA, No. 37 at p. 2; Rheem, No. 38 at
p. 2; HTP, No. 41 at p. 1) 8 Bradford
White recommended that the uniform
efficiency descriptor be limited to water
heaters with inputs less than 200,000
Btu/h, which would cover those water
heaters intended for residential
applications. (Bradford White, No. 30 at
p. 2) AHRI, AO Smith, Rheem, and HTP
indicated that the legislation was
intended to apply to residential
products only and that development of
a uniform metric and test method for all
water heaters is not realistic given the
substantially different duty cycles
between water heaters meant for
commercial applications and those
meant for residential applications.
(AHRI, No. 33 at pp. 1–2; AO Smith, No.
34 at p. 1; Rheem, No. 38 at p. 2; HTP,
No. 41 at p. 1) The joint commenters
supported a realignment of the scope
that includes all water heaters except
those clearly designed to deliver large
amounts of hot water. (Joint comment,
No. 35 at p. 2) NEEA recommended that
DOE should focus on water heaters
8 All references to comments received in response
to the October 2011 and January 2013 RFI’s identify
the commenter, the identification number applied
by DOE, and the page of the comment package on
which the particular point has been discussed.
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meant for residential and small
commercial applications. (NEEA, No. 37
at p. 2) No commenters supported
DOE’s tentative interpretation that
AEMTCA requires the uniform
descriptor to apply to all types of
residential and commercial water
heaters.
After considering the comments
received, DOE proposes to exclude from
the uniform efficiency descriptor any
specific category of water heater that
does not have a residential use. As
noted above, AEMTCA provides that
DOE can exclude from the uniform
descriptor any specific categories of
covered water heaters that do not have
a residential use, can be clearly
described in the final rule, and are
effectively rated using the current
thermal efficiency and standby loss
descriptors. (42 U.S.C. 6295(e)(5)(F))
DOE received 13 comments regarding
how to define water heaters that do not
have a residential application. In light of
these comments, DOE proposes to
define a new classification of
commercial water heaters for which the
uniform efficiency descriptor would
apply (i.e., ‘‘light commercial water
heaters’’), which DOE believes can be
clearly distinguished from the
commercial water heaters for which the
uniform descriptor would not apply
under this proposal. DOE believes that
the current metrics for commercial
water heaters that are used only in
commercial settings are appropriate and
adequate to characterize the
performance of such commercial water
heaters. Commercial water heaters
typically cycle less than residential
water heaters due to longer run-times
followed by standby periods.
(Residential water heaters are typically
subject to a number of small draws and
short on-times throughout the day.) As
a result, cycling losses of water heaters
used in commercial applications are
generally not as significant as those
used in residential applications. Thus,
DOE believes that thermal efficiency
and standby loss metrics adequately
characterize the efficiency in active and
standby modes, respectively.
AHRI, AO Smith, and HTP suggested
that the following characteristics may be
suitable to distinguish water heaters
intended for non-residential use: (1)
Designed to deliver water at a
thermostatically controlled temperature
of 180 °F or more; (2) bear a Code
Symbol Stamp signifying compliance
with the requirements of the American
Society of Mechanical Engineers
(ASME) Boiler and Pressure Vessel
Code; and (3) require electricity as the
primary energy source and require the
use of 3-phase external supply. (AHRI,
No. 33 at p. 2; AO Smith, No. 34 at p.
1; HTP, No. 41 at p. 2) The joint
commenters likewise stated that water
heaters utilizing 3-phase electric power,
designed to deliver water above 180 °F,
and falling under the guise of the ASME
pressure vessel code are not typical of
residential applications. (Joint
comment, No. 35 at p. 2) NEEA
commented that there are many water
heaters with features that make them
unsuitable for residential and small
commercial applications and provided
examples of units with set points of
180 °F or higher, 3-phase power, and
large input ratings and volumes. (NEEA,
No. 37 at p. 2) AHRI, AO Smith, Rheem,
and HTP also provided tables of rated
inputs and storage volumes to
distinguish water heaters that are not
intended for residential applications.
(AHRI, No. 33 at p. 2; AO Smith, No. 34
at p. 1; Rheem, No. 38 at p. 2; HTP, No.
41 at p. 2) Those limits are grouped by
water heater type and are shown in
Table III.1.
TABLE III.1—SUGGESTED CAPACITY LIMITATIONS FOR DEFINING NON-RESIDENTIAL WATER HEATERS
Water heater type
Indicator of non-residential application by commenter
Gas-fired storage ................................................
AHRI, Rheem: Rated input >100 kBtu/h; Rated storage volume <20 gallons and >100 gallons.
AO Smith: Rated Input > 100kBtu/h; Rated storage volume >100 gallons.
HTP: Rated input >150 kBtu/h; Rated storage volume <20 gallons and >120 gallons.
AHRI, AO Smith, Rheem: Rated input >140 kBtu/h; Rated storage volume >50 gallons.
AHRI, Rheem, HTP: Rated input >12 kW; Rated storage volume <20 gallons and >120 gallons.
AO Smith: Rated Input >12 kW; Rated storage volume >120 gallons.
AHRI, AO Smith, Rheem, HTP: Rated current >24 Amperes; Rated voltage >250 V; Rated
storage volume >120 gallons.
AHRI, AO Smith, Rheem, HTP: Rated input >200 kBtu/h; Water volume >1 gallon per 4000
Btu/h of input.
AHRI, Rheem: Rated input >12 kW; Water volume >2 gallons.
AO Smith: Rated input >25 kW; Water volume >2 gallons.
AHRI, Rheem, AO Smith: Rated input >210 kBtu/h; Water volume >2 gallons.
Oil-fired storage ..................................................
Electric storage ...................................................
Heat Pump with Storage ....................................
Gas-fired instantaneous ......................................
Electric instantaneous .........................................
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Oil-fired instantaneous ........................................
Bradford White recommended that
the new descriptor be limited to water
heaters with inputs less than 200,000
Btu/h because, according to the
commenter, water heaters with inputs
greater than or equal to 200,000 Btu/hr
are not used in residential applications
since such a high input is not required
in these types of applications. (Bradford
White, No. 30 at p. 2) AGA stated that
efficiency descriptors and test methods
are best developed through consensusbased processes and referred DOE to the
scope that is currently present in
ASHRAE Standard 118.2, Method of
Testing for Rating Residential Water
Heaters. (AGA, No. 31 at 2)
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Upon considering these comments,
DOE agrees with commenters that a unit
requiring three-phase electricity would
nearly always be used only in a
commercial setting, as residential homes
are wired almost exclusively for singlephase power. Likewise, DOE agrees with
commenters that units with an ASME
pressure vessel rating or units capable of
delivering water at temperatures at or
exceeding 180 °F would generally only
be used in commercial settings. As a
result, DOE proposes to use these three
criteria as the basis for defining ‘‘light
commercial’’ water heaters that have
residential applications.
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DOE also considered the input and
storage capacity criteria proposed by
stakeholders to differentiate commercial
water heaters that would only be used
in non-residential applications from
commercial water heaters that could
have residential applications. DOE notes
that equipment that was once classified
as residential based on input capacity or
storage volume might now be installed
in a commercial setting and vice versa.
Given that such changes occur over time
as new technologies develop, DOE is
declining to propose criteria in this
NOPR on an input capacity basis.
Instead, DOE believes that the three
criteria discussed in the preceding
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paragraph are adequate to define the
class of commercial water heaters that
could have residential applications.
Consequently, DOE proposes to add
the following definition of ‘‘light
commercial water heater’’ to 10 CFR
431.102:
Light commercial water heater means
any gas-fired, electric, or oil storage or
instantaneous commercial water heater
that meets the following conditions:
(1) For models requiring electricity,
uses single-phase external power
supply;
(2) Is not capable of delivering hot
water at temperatures of 180 °F or
above; and
(3) Does not bear a Code Symbol
Stamp signifying compliance with the
requirements of the ASME Boiler and
Pressure Vessel Code.
Although light commercial water
heaters could have residential
applications, DOE notes that the new
‘‘light commercial water heater’’
definition represents a type of water
heater that, to a significant extent, is
distributed in commerce for industrial
or commercial use. These water heaters
were and continue to be covered
industrial equipment, and, if these
proposals are finalized, will continue to
be subject to the regulations in part 431
and the certification requirements for
commercial and industrial equipment in
part 429. Similarly, although DOE
recognizes that some consumer water
heaters may be installed in a
commercial setting, those waters heaters
are covered consumer products for the
purposes of DOE regulations, the
regulations in part 430 continue to
apply, and they must be certified as
consumer products under part 429.
If a commercial water heater does not
meet all of these three conditions, it
would be classified as a commercial
water heater that would not be expected
to be used in residential applications
and would be subject to the current test
methods prescribed in 10 CFR 431.106,
which reference ANSI Z21.10.3. If a
commercial water heater meets all three
criteria, DOE proposes to consider it a
‘‘light commercial water heater,’’ which
would be subject to the uniform
efficiency descriptor and test method
proposed in today’s NOPR. Accordingly,
DOE proposes to add a row to Table 1
of 10 CFR 431.106 specifying 10 CFR
part 430, subpart B, Appendix E as the
test method for this class of equipment.
DOE seeks comment on both the
proposed definition of ‘‘light
commercial water heater’’ and the
proposal to subject this equipment to
the test methods at Appendix E. This is
identified as issue 1 in section V.E,
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‘‘Issues on Which DOE Seeks
Comment.’’
DOE also received comments
recommending that certain types of
water heaters should be excluded from
the uniform descriptor for various
reasons. NREL commented that storage
tanks do not make a complete water
heating system, so an energy factor is
not appropriate. NREL elaborated that a
rating using a standby loss coefficient
could be appropriate. (NREL, No. 29 at
pp. 3–4) AHRI, AO Smith, and HTP
recommended that DOE exclude from
the descriptor: (1) Unfired storage tanks
because they do not actually heat water;
(2) add-on heat pumps because DOE has
previously determined that these are not
covered products and they are not
complete water heaters; and (3) hot
water supply boilers because, by
definition, they have inputs exceeding
the values listed in the commenters’
recommendations and because these
products are all subject to the
requirements of the ASME Boiler and
Pressure Vessel Code (AHRI, No. 33 at
pp. 4–5; AO Smith, No. 34 at p. 3; HTP,
No. 41 at p. 5) Rheem expressed support
for AHRI’s list of exclusions. (Rheem,
No. 38 at p. 2) NEEA recommended that
DOE should exclude water storage tanks
from the uniform descriptor because
they are technically not water heaters
and they simply store water heated
elsewhere. NEEA also commented that
unfired storage tanks should not be
excused from all efficiency
requirements since standby loss
efficiency is important for all hot water
storage vessels, regardless of where and
how the water is heated. (NEEA, No. 37
at p. 2) Conversely, the joint
commenters recommended that the
uniform efficiency descriptor should be
able to effectively measure the
efficiency of electric heat pump water
heaters without an integrated storage
tank in the event it is included in future
Federal coverage. (Joint comment, No.
35 at p. 5)
DOE has tentatively determined that
certain commercial equipment such as
unfired storage tanks and add-on heat
pump water heaters are not
appropriately rated using the uniform
descriptor applicable to other water
heaters. Unfired storage tanks are not
complete water-heating systems and
require additional equipment in the
field to operate. Thus, DOE believes that
other metrics may be more appropriate
for these devices with limited
functionality compared to actual water
heaters, and that their performance as
part of a complete water-heating system
is so dependent upon other components
of the system that use of the uniform
descriptor may be unrepresentative of
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its performance as a system. For add-on
heat pump water heaters, DOE agrees
with stakeholders that DOE has
previously determined that these are not
covered residential products. As such,
DOE only has authority to cover
commercial add-on heat pumps;
however, this equipment does not have
residential applications, and, therefore,
is not suitable for inclusion in the
uniform efficiency descriptor. DOE has
also tentatively determined that hot
water supply boilers are more
appropriately rated using the existing
metrics for commercial water heaters, as
this equipment has very high input
ratings and are subject to the ASME
Boiler and Pressure Vessel Code, and
their use is similar to that of other
commercial water heaters in commercial
applications. DOE will address the types
of water-heating equipment that are
excluded from the uniform descriptor
(e.g., unfired storage tanks, add-on heat
pump water heaters, and hot water
supply boilers) in a subsequent test
procedure rulemaking.
2. Storage Capacity Limits
Under the existing regulatory
definitions, DOE’s current residential
water heater test procedures are not
applicable to gas or electric water
heaters with storage tanks that are at or
above 2 gallons (7.6 L) and less than 20
gallons (76 L). In terms of the high end
of the capacity range, the current DOE
test procedure for residential water
heaters only applies to gas-fired water
heaters with storage volumes less than
or equal to 100 gallons (380 L), electric
resistance and heat pump storage water
heaters with storage volumes less than
or equal to 120 gallons (450 L), and oilfired water heaters with storage volumes
less than or equal to 50 gallons (190 L).
10 CFR part 430, subpart B, appendix E,
sections 1.12.1, 1.12.2, and 1.12.4.
In the 1998 rulemaking establishing
test procedures for residential water
heaters, DOE proposed to include units
with storage volumes between 2 and 20
gallons, but commenters raised concerns
that the test procedure demand of 64.3
gallons per day was not appropriate for
these small units. 63 FR 25996, 26000
(May 11, 1998). At that time, DOE
concluded that the data to determine the
appropriate daily hot water
consumption did not exist and that
alternative procedures proposed by
commenters were not fully evaluated.
For these reasons, the Department
tabled consideration of the inclusion of
these water heaters until a future
revision of the DOE test procedure. In
recent years, however, water heaters
with such capacities have begun to
populate the market. The definitions in
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the DOE test procedure (cited above)
specify that instantaneous-type water
heaters have a storage volume of less
than two gallons (7.6 L) and that electric
or gas storage-type water heaters have a
storage volume of 20 gallons (76 L) or
more. The storage capacity of oil water
heaters in the test method is not
restricted by a lower limit, with the
specification stating that an oil-fired
storage water heater simply has a rated
capacity less than or equal to 50 gallons
(190 L). 10 CFR part 430, subpart B,
appendix E, sections 1.7 and 1.12. The
definition for ‘‘Storage-type Water
Heater of More than 2 Gallons (7.6
Liters) and Less than 20 Gallons (76
Liters)’’ is currently reserved. Id. at
section 1.12.5. DOE requested comment
on the potential to address this gap in
the October 2011 RFI, and received
several comments from interested
parties. 76 FR 63211, 63213 (Oct. 12,
2011).
DOE received 11 comments in
support of the inclusion of water heaters
with storage volumes between 2 and 20
gallons. (Bradford White, No. 2 at p. 1;
PGE, No. 3 at p. 1; SCE, No. 4 at p. 1;
Stone Mountain Technologies, No. 5 at
p. 2; AO Smith, No. 8 at p. 1; NEEA, No.
9 at p. 2; AHRI, No. 12 at p. 1; NREL,
No. 14 at p. 7; NRDC, No. 20 at p. 1;
AET, No. 22 at p. 7; ACEEE, No. 24 at
pp. 3–4). No comments were received
opposed to this measure.
AHRI, AO Smith, Bradford White, and
Lochinvar suggested that a distinct test
procedure is needed for electric storage
water heaters with volumes between 2
and 20 gallons since the current test
method is not suited for such point-ofuse products and that this test method
measure only the standby loss of the
unit. (Bradford White, No. 2 at p. 1; AO
Smith, No. 8 at p.1; Lochinvar, No. 10
at p. 1; AHRI, No. 12 at p. 2) Stone
Mountain Technologies stated further
that all electric resistance water heaters
should be subjected to only a standby
loss test, because differences between
models is almost solely based on
standby losses. (Stone Mountain
Technologies, No. 5 at p. 3) DOE has
considered these points but has
tentatively concluded that, for equity
across water-heating technologies, all
water heaters should be tested under a
simulated-use profile as will be
discussed in section III.C. DOE proposes
a profile that is appropriate for point-ofuse water heaters, so any concerns that
the current test method is not suitable
are addressed by the proposed test
method. This profile will simulate the
way that a point-of-use water heater is
used in the field and will capture any
operational characteristics that could
affect its efficiency. DOE also believes
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that a simulated-use test will better
capture any potential cycling losses or
inefficiencies in meeting the demands
imposed on all water heaters.
After considering the comments
received, DOE proposes to expand the
scope of the water heater test procedure
for the uniform efficiency descriptor to
include water heaters with storage
volumes between 2 and 20 gallons. The
proposed modifications will specify the
method of test set-up (including
instrumenting such water heaters), a test
method to assess the delivery capacity,
and the draw pattern that would be used
to determine the energy efficiency of
such units. The proposed amendments
for water heaters with storage volumes
between 2 and 20 gallons are discussed
in detail in section III.C of today’s notice
of proposed rulemaking.
DOE is not aware of any residential
water heaters available on the market
with storage volumes above 100 gallons,
120 gallons, and 50 gallons for gas-fired,
electric (resistance and heat pump), and
oil-fired water heaters, respectively, that
would be covered as residential
products under EPCA. Due to the lack
of water heaters with very large storage
volumes that meet the definition of a
residential ‘‘water heater,’’ DOE
tentatively concluded in the October
2011 RFI that it is unnecessary to
expand the scope of the test procedure
to include gas-fired products over 100
gallons, electric products over 120
gallons, or oil-fired products over 50
gallons, and requested comment on this
tentative conclusion. 76 FR 63211,
63213 (Oct. 12, 2011).
Four commenters (Bradford White,
AO Smith, NEEA, AHRI) supported
DOE’s position to maintain the existing
capacity limits for storage water heaters,
while three commenters (Stone
Mountain Technologies, NREL, AET)
recommended that the test method be
expanded to include all water heaters
with storage volumes from 0 to 120
gallons. (Bradford White, No. 2 at p. 1;
AO Smith, No. 8 at p. 1; NEEA, No. 9
at p. 2; AHRI, No. 12 at p. 1; Stone
Mountain Technologies, No. 5 at p. 2;
NREL, No. 14 at p. 8; AET, No. 22 at pp.
6–7) AET noted that the pressure vessel
code from the American Society of
Mechanical Engineers requires that
vessels intended to store fluids under
pressure must individually undergo a
rigorous test and inspection procedure if
they have volumes greater than 120
gallons. AET noted that because these
test and certification procedures are
expensive, manufacturers will avoid
making products intended for
residential use that require an ASME
inspection and code stamp. For this
reason, AET commented that the upper
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limit of 120 gallons would be
appropriate for all residential water
heaters. AET further suggests that
expanding the volume limit to 120
gallons would prevent manufacturers
from evading efficiency standards by
marketing water heaters slightly larger
than the currently specified limits.
(AET, No. 22 at pp. 6–7)
The subsequent passage of AEMTCA
has necessitated that DOE reconsider
the scope of all water heater test
procedures. DOE has considered these
comments, as well as the provisions of
AEMTCA, and proposes to expand the
scope of the test procedure to include
all covered water heaters that could
have residential applications and
remove the limitations on maximum
storage volume that are currently in the
residential test procedure for gas-fired,
electric, and oil storage water heaters.
The Department’s authority to regulate
water heaters is limited to those
explicitly defined as covered products
by EPCA. EPCA defines the term ‘‘water
heater’’ as a product which utilizes oil,
gas, or electricity to heat potable water
for use outside the heater upon demand.
(42 U.S.C. 6291(27)) Further, EPCA
defines storage type units which include
gas storage water heaters with an input
of 75,000 Btu per hour or less, oil
storage water heaters with an input of
105,000 Btu per hour or less, and
electric storage water heaters with an
input of 12 kilowatts or less. EPCA also
defines instantaneous type units, which
are water heaters that contain no more
than one gallon of water per 4,000 Btu
per hour of input, including gas
instantaneous water heaters with an
input of 200,000 Btu per hour or less,
oil instantaneous water heaters with an
input of 210,000 Btu per hour or less,
and electric instantaneous water heaters
with an input of 12 kilowatts or less.
Lastly, EPCA defines covered heat
pump type units, which have a
maximum current rating of 24 amperes
at a voltage no greater than 250 volts,
and which are designed to transfer
thermal energy from one temperature
level to a higher temperature level for
the purpose of heating water, and
include all ancillary equipment such as
fans, storage tanks, pumps, or controls
necessary for the device to perform its
function. Id.
For commercial water heating
equipment, EPCA defines ‘‘storage water
heater’’ as a water heater that heats and
stores water within the appliance at a
thermostatically controlled temperature
for delivery on demand, and does not
include units with an input rating of
4000 Btu per hour or more per gallon of
stored water. EPCA also defines
‘‘instantaneous water heater’’ as a water
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heater that has an input rating of at least
4000 Btu per hour per gallon of stored
water. Lastly, EPCA defines the term
‘‘unfired hot water storage tank’’ as a
tank used to store water that is heated
externally. (42 U.S.C. 6311(12))
AEMTCA requires that the new metric
apply to the extent possible to all waterheating technologies used in residential
applications. (42 U.S.C. 6295(e)(5)(F)
and (H)) DOE believes that the test
method proposed in today’s NOPR
adequately addresses large water heaters
regardless of storage volume, provided
that they are used in residential
applications. As noted previously in
section III.A.1, DOE proposes to exclude
units used only in non-residential
applications, but DOE does not believe
that storage volume alone would dictate
whether a unit is residential or
commercial. As noted by AET, the
ASME pressure vessel code requires that
vessels intended to store fluids under
pressure must undergo a rigorous test
and inspection procedure if they have
volumes greater than 120 gallons. Any
such products would be ASME pressure
vessel rated, and under the definition of
‘‘light commercial water heater’’
proposed in section III.A.1, would not
be subject to the uniform efficiency
descriptor, which would effectively
limit the maximum storage volume to
120 gallons for the purposes of using the
uniform descriptor. For these reasons,
DOE proposes to eliminate the
maximum storage volume limitations
from the residential water heater test
procedure.
3. Input Capacity Limits
DOE’s current residential water heater
test procedure is not applicable to gasfired instantaneous water heaters with
input capacities at or below 50,000 Btu/
h or at or above 200,000 Btu/h. 10 CFR
Part 430, subpart B, Appendix E, section
1.7.2. In addition, the test procedure is
not applicable to gas-fired storage water
heaters with input capacities above
75,000 Btu/h, electric storage water
heaters with input ratings above 12 kW,
and oil-fired storage water heaters with
input ratings above 105,000 Btu/h. 10
CFR Part 430, subpart B, Appnedix E,
section 1.12.
DOE proposes to eliminate the
minimum limit on the firing rate of
instantaneous gas water heaters of
50,000 Btu/h, as AEMTCA requires that
the new metric apply to the maximum
extent practical to all water-heating
technologies intended for residential
application. (42 U.S.C. 6295(e)(5)(F) and
(H)) As discussed in section III.C, DOE
proposes to adopt multiple draw
patterns that would vary based on the
delivery capacity of the water heater.
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Because the draw pattern would be
dependent upon delivery capacity, DOE
believes that small gas-fired
instantaneous units could be
appropriately tested under the proposed
procedure. Thus, DOE believes there is
no reason to retain this lower limit on
gas-fired instantaneous water heater
delivery capacity.
Similarly, DOE proposes to remove
the maximum input ratings for gas-fired,
electric, and oil-fired storage water
heaters, and for gas-fired instantaneous
water heaters from the test procedure.
DOE believes that the proposed test
procedure, because it varies based on
delivery capacity, is applicable to units
with input capacities above those
included in the current residential water
heater test procedure. Although these
maximum input limitations were based
upon DOE’s ‘‘water heater’’ definition at
42 U.S.C. 6291(27), because AEMTCA
requires that the new metric apply to all
water-heating technologies except those
that do not have a residential use, DOE
believes that such limits are no longer
controlling or appropriate in terms of
the scope of the water heaters test
procedure. As discussed in section
III.A.1, given the technology shifts that
occur over time, DOE does not believe
input capacity limitations to be a
consistent indicator of whether a
product has a residential use.
4. Electric Instantaneous Water Heaters
DOE’s current test procedures do not
contain a definition for ‘‘electric
instantaneous water heater,’’ but rather
have a space reserved to define that
term. 10 CFR Part 430, subpart B,
appendix E, section 1.7.1. EPCA defines
‘‘electric instantaneous water heater’’ as
having an input capacity of 12 kilowatts
(kW) or less. (42 U.S.C. 6291(27)(B)) As
noted by commenters and discussed in
section III.A.1, the heating power
required for electric instantaneous water
heaters intended for whole-home
applications is typically much higher
than the power capability commonly
found in storage-type electric water
heaters. Given the emergence of electric
instantaneous water heaters on the
market, DOE requested comment in the
October 2011 RFI on addressing this gap
in the test procedure by prescribing a
definition specifically for the term
‘‘electric instantaneous water heater.’’
DOE noted in the RFI that although the
24-hour simulated use test in DOE’s test
procedure for instantaneous water
heaters at 10 CFR Part 430, subpart B,
appendix E, section 5.2.4 is titled ‘‘24hour Simulated Use Test for Gas
Instantaneous Water Heaters,’’ the
method is also applicable for electric
instantaneous water heaters. DOE
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requested comment on potential
modifications to the DOE test procedure
to address electric instantaneous water
heaters.
DOE received thirteen comments in
support of the proposal to amend DOE’s
water heater test procedure to include
electric instantaneous water heaters.
(Bradford White, No. 2 at p. 1; PGE, No.
3 at p. 1; SCE, No. 4 at p. 1; Stone
Mountain Technologies, No. 5 at p. 2;
AO Smith, No. 8 at p. 1; NEEA, No. 9
at p. 2; Lochinvar, No. 10 at p. 1; AHRI,
No. 12 at p. 1; NREL, No. 14 at p. 9;
NRDC, No. 20 at p. 1; Bosch, No. 17 at
p. 1; AET, No. 22 at pp. 8–9; and
ACEEE, No. 24 at p. 4.) DOE received no
comments opposing such an inclusion.
Bradford White, AO Smith, AHRI,
NREL, AET, and ACEEE also suggested
that the test procedure should be
amended to cover electric instantaneous
water heaters with heating rates higher
than 12 kW in order to accommodate
units that are meant to serve wholehome applications. (Bradford White, No.
2 at p. 1; AO Smith, No. 8 at p. 1; AHRI,
No. 12 at p. 2; NREL, No. 14 at p. 9;
AET, No. 22 at pp. 8–9; ACEEE, No. 24
at p. 4) AHRI and ACEEE suggested that
the test procedure for electric
instantaneous water heaters should be
made applicable to water heaters with
inputs up to 25 kW (AHRI, No. 12 at p.
2; ACEEE, No. 24 at p. 4), while
Bradford White suggested an input limit
of 35 kW (Bradford White, No. 2 at p.
1), and NREL recommended an input
limit of 50 kW (NREL, No. 14 at p. 9).
AET commented that the upper limit be
based on a maximum current of 200
Amperes, which is the typical
maximum value allowed in residences
in the United States. (AET, No. 22 at pp.
8–9) In response to the January 2013
RFI, Aquarensics, UHCL1, UHCL2, and
Seisco commented that the test method
should cover electric instantaneous
water heaters with input ratings in
excess of 12 kW. (Aquarensics, No. 43
at p.1; UHCL1, No. 44 at p. 1; UHCL2,
No. 45 at p. 1; Seisco, No. 47 at p. 1)
Further, Aquarensics, UHCL1, UHCL2,
and Seisco all commented that
commercially-available electric
instantaneous water heaters that are
designed for residential applications
have input ratings greater than the
current limit of 12 kW for residential
electric water heaters under EPCA.
(Aquarensics, No. 43 at p. 2; UHCL1,
No. 44 at p. 1; UHCL2, No. 45 at p. 1;
Seisco, No. 47 at p. 3) Aquarensics and
UHCL2 noted residential applications
that used units with an input rating of
28 kW. UHCL1 commented that wholehouse instantaneous water heaters
typically require 25 kW to 35 kW.
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Seisco stated that residential electric
instantaneous water heaters having
inputs above 30 kW are commonly built
and have been used for residential
applications since 1999. Seisco further
stated that electric instantaneous water
heaters with input ratings up to 35 kW
are used for whole-house applications.
After considering the comments on
the RFIs, DOE proposes to amend its
water heaters test procedure to include
applicable provisions for electric
instantaneous water heaters, and to
define the term ‘‘electric instantaneous
water heater’’ as follows:
Electric Instantaneous Water Heater
means a water heater that uses
electricity as the energy source, initiates
heating based on sensing water flow, is
designed to deliver water at a controlled
temperature of less than 180 °F (82 °C),
and has a manufacturer’s specified
storage capacity of less than 2 gallons
(7.6 liters). The unit may use a fixed or
variable power input.
DOE notes that the proposed
definition would encompass both
electric instantaneous water heaters that
are residential (i.e., with an input
capacity of 12 kW or less) and
commercial (i.e., with an input capacity
greater than 12 kW). Because water
heaters both above and below 12 kW
have residential applications, both types
would be covered by the uniform
efficiency descriptor. Today’s proposed
rule provides for a maximum flow rate
test, as well as a test to obtain the energy
efficiency expressed in terms of Energy
Factor (EF). These tests are identical to
those implemented for gas
instantaneous water heaters.
B. Uniform Efficiency Descriptor
AEMTCA provided the following
options for the uniform efficiency
descriptor metric: (1) A revised version
of the energy factor descriptor currently
in use; (2) the thermal efficiency and
standby loss descriptors currently in
use; (3) a revised version of the thermal
efficiency and standby loss descriptors;
(4) a hybrid of descriptors; or (5) a new
approach. (42 U.S.C. 6295(e)(5)(G)) In
the January 2013 RFI, DOE requested
comment on the appropriate metric to
be used as the uniform descriptor. 78 FR
2340, 2344–45 (Jan. 11, 2013). Eight
parties provided comments supporting
the use of the energy factor metric, but
obtained using a different method of test
than provided in the current test
procedure. (NREL, No. 29 at p. 1;
Bradford White, No. 30 at p. 1; AHRI,
No. 33 at p. 3; AO Smith, No. 34 at p.
2; GE, No. 36 at p. 1; NEEA, No. 37 at
p. 1; Rheem, No. 38 at p. 3; HTP, No.
41 at p. 3) The joint comment indicated
that the existing energy factor metric is
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inadequate and indicated support for a
series of simulated use tests that would
result in a revised energy factor. (Joint
comment, No. 35 at p. 1) No comments
were received that proposed the use of
thermal efficiency, standby loss factor,
or any new metrics.
NREL stated that the thermal
efficiency and standby loss metrics are
not suitable as primary metrics for
residential applications, because they
do not completely capture performance.
(NREL, No. 29 at p. 1) AHRI and HTP
indicated that the energy factor metric
would enable testing agencies to build
on prior experience in testing water
heaters for residential applications, that
it would result in an easier conversion
from the current metric to the uniform
descriptor, and that it can be technology
neutral. (AHRI, No. 33 at pp. 3–4; HTP,
No. 41 at p. 3) HTP also suggested a
voluntary rating for combined waterheating and space-heating appliances
based on ASHRAE Standard 124,
Methods of Testing for Rating
Combination Space-Heating and WaterHeating Appliances. (HTP, No. 41 at p.
4) AO Smith suggested that the uniform
descriptor be given a qualifying name to
distinguish it from the current energy
factor, providing ‘‘New Energy Factor’’
as an example. (AO Smith, No. 34 at p.
2) GE indicated that an energy factor
metric would be technology neutral and
that it would minimize complexity in
converting from the current metric to
the uniform descriptor. (GE, No. 36 at
p. 1)
NRCan provided a report
documenting results of testing of two
commercial water heaters that are
marketed towards the residential sector
under the existing residential test
procedure. (NRCan, No. 42 at p. 1) The
report did not identify any problems or
concerns with testing these units under
the existing test procedure.
Based on these comments, DOE
proposes a modified version of the
existing energy factor metric as the
uniform descriptor for products covered
under this test procedure. DOE believes
that an energy factor that is derived
from a simulated use test will provide
a technology-neutral metric for the
efficiency of water heaters intended for
residential applications. The simulated
use test will capture key performance
aspects such as burner efficiency,
standby loss, and cycling that affect
energy efficiency seen by consumers.
However, DOE will not adopt voluntary
rating requirements for combination
appliances at this time, as that is outside
the scope of today’s test procedure
NOPR. Further, DOE does not plan to
change the name, as suggested by A.O.
Smith. The Department believes that
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because standards and ratings will be
transitioned to the new metric and the
old metric will be come obsolete, there
will be little confusion by maintaining
the name ‘‘energy factor.’’
C. Draw Pattern
The term ‘‘draw pattern’’ describes
the number, flow rate, length, and
timing of hot water removal from the
water heater during testing. Primary
decisions in developing draw patterns
include the total amount of water to be
removed during the test and the number
of draws during the test. The total
amount of water taken in each draw,
which is a function of the flow rate and
the length of the draw, must also be
specified. Finally, the spacing between
those draws is needed to complete the
specification of the draw pattern.
The current residential water heater
test procedure includes a 24-hour
simulated-use test for determining
energy factor. 10 CFR Part 430, subpart
B, appendix E, sections 5.1.5 and 5.2.4.
The 24-hour test specifies that 6 draws
of equal volume be removed from the
water heater in the first 6 hours of the
test for a total draw of 64.3 ± 1.0 gallons
(243.4 ± 3.8 L).9 Following the six
draws, the water heater sits in an idle
mode for the remainder of the 24-hour
test. Id. The draw pattern is the same
regardless of the type (e.g., gas-fired,
electric resistance, oil-fired, heat pump,
storage, instantaneous) and
characteristics (e.g., storage volume,
input capacity) of the water heater.
In the October 2011 RFI, DOE noted
that recent data 10 11 12 suggest that the
draw pattern can impact the energy
factor of a water heater and can
potentially offer an advantage to one
type of water heater technology over
another. 76 FR 63211, 63213 (Oct. 12,
2011). These studies also suggest that
the existing draw pattern in the
simulated use test may not be
9 10 CFR Part 430, subpart B, appendix E, section
5.1.5 currently states, ‘‘During the simulated use
test, a total of 64. ±3 1.0 gallons (243 ± 2.8 liters)
shall be removed.’’ DOE contends that the total is
in error and should instead read ‘‘64.3 ± 1.0 gallons
(243 ± 2.8 liters).’’ No correction is proposed at this
time since the quantity will change in the proposed
test procedure.
10 Healy, WM, Ullah, T, and Roller, J., ‘‘InputOutput Approach to Predicting the Energy
Efficiency of Residential Water Heaters—Testing of
Gas Tankless and Electric Storage Water Heaters,’’
ASHRAE Transactions 117 (2011).
11 Hoeschele, M.A. and Springer, D.A., ‘‘Field and
Laboratory Testing of Gas Tankless Water Heater
Performance,’’ ASHRAE Transactions 114 (2): 453–
461 (2008).
12 Bohac, D, Schoenbauer, B., Hewett, M.,
Lobenstein, M.S., Butcher, T. ‘‘Actual Savings and
Performance of Natural Gas Tankless Water
Heaters,’’ Center for Energy and Environment
Report for Minnesota Office of Energy Security
(August 30, 2010).
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representative of actual draw patterns to
which water heaters are subjected in the
field. Because different water heaters
will be subjected to different field
demands (consumer usage patterns) due
to operational or performance
differences, DOE proposes to revise the
draw pattern to be more representative
of typical usage patterns experienced in
the field. DOE is also proposing to
amend its test procedure to provide for
different draw patterns for different
water heaters based upon the
characteristics of each water heater,
such as the rate of hot water the unit can
provide, the storage volume, and the
heating rate (i.e., input rate). In the
October 2011 RFI, DOE sought comment
on improvements that could be made to
DOE’s existing 24-hour simulated use
test procedure for water heaters.
Additional comments were sought by
and provided in response to the January
2013 RFI.
DOE received 27 comments that
addressed these issues. Four
commenters (AGA, Bosch, General
Electric, and Rheem) recommended that
DOE maintain the test procedure as it
currently stands. AGA argued the
importance of consistency with
previous ratings. (AGA, No. 13 at p. 1)
Bosch commented that the current test
procedure covers a large quantity of
applications without trying to estimate
the usage for any given household.
(Bosch, No. 17 at p. 2) General Electric
wrote that the six-draw requirement is
appropriate for medium-volume water
heaters. (GE, No. 21 at pp. 1–2) Rheem
suggested that the added scope of
covered products called for by AEMTCA
would best be handled by maintaining
the existing residential water heater test
procedure at this time while continuing
to pursue an amended test method.
(Rheem, No. 38 at p. 3) Rheem further
argued that such an incremental
approach would allow manufacturers to
continue on a path to meet minimum
efficiency requirements imposed by
amended energy conservation
standards.
In total, DOE received twenty-three
comments recommending that the
Agency move away from the six-draw
requirement as currently specified in
the DOE test procedure (although
certain of these comments were
multiple submissions from the same
interested party). (Bradford White, No. 2
at p. 2; PGE, No. 3 at p. 2; SCE, No. 4
at p. 2; Stone Mountain Technologies,
No. 5 at p. 2; AO Smith, No. 8 at p. 2;
NEEA, No. 9 at p. 2; NPGA, No. 11 at
pp. 1–2; AHRI, No. 12 at p. 2; NREL, No.
14 at pp. 1–2; GTI, No. 15 at p. 2;
NRCan, No. 16 at pp. 1–2; NRDC, No.
20 at p. 2; AET, No. 22 at p. 2; ACEEE,
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No. 24 at p. 1; NREL, No. 29 at p. 2;
Bradford White, No. 30 at p. 2; AHRI,
No. 33 at p. 4; AO Smith, No. 34 at p.
3; Joint comment, No. 35 at p. 1; GE, No.
36 at p. 1; NEEA, No. 37 at p. 3; APGA,
No. 39 at p. 2; AHRI, No. 46 at p. 1)
Bradford White indicated its support
for a 24-hour simulated use test because
it is ‘‘technology blind.’’ (Bradford
White, No. 2 at p. 2) PGE and SCE
recommended that the draw pattern be
modified to reduce bias towards
tankless water heaters, and that different
draw patterns be applied based on the
capacity of the water heater. (PGE, No.
3 at p. 2; SCE, No. 4 at p. 2) Stone
Mountain Technologies indicated that
recent studies have shown that the
efficiency of most gas-fired tankless
models is overstated using the current
DOE test procedure. The commenter
stated that this finding, along with the
addition of small water heaters within
the scope of the test procedure,
necessitate a modification to the current
draw pattern. Further, Stone Mountain
Technologies opined that an appropriate
number of draws for a practical test
method would be between 10 and 15.
(Stone Mountain Technologies, No. 5 at
p. 2) AO Smith and AHRI supported
revising the test procedure while
retaining the simulated-use concept and
indicated that an AHRI industry effort is
underway to develop a modified draw
pattern. (AO Smith, No. 8 at p. 2; AHRI,
No. 12 at p. 2; AHRI, No. 33 at p. 4; AO
Smith, No. 34 at p. 3) AHRI submitted
a proposed revised energy factor test
method to DOE, which was considered
for today’s NOPR and is discussed
below. (AHRI, No. 46, pp. 1–7) NEEA
stated that it is clear that the draw
pattern used in the current test
procedure bears no resemblance to that
seen in actual use, and accordingly, the
current draw pattern should be
abandoned. (NEEA, No. 9 at p. 2) NREL
commented that the draw patterns in
the new test must be statistically
representative of actual usage, meaning
that the frequency distributions of key
variables in the test procedure (such as
volume of draws and timing between
draws) are reasonably matched to field
data. Furthermore, it commented that
DOE should ensure that any proposed
test draw profile must be consistent
with all relevant statistical distributions
determined from the database of hot
water draws created by the Lawrence
Berkeley National Laboratory (LBNL).
(NREL, No. 14 at pp. 1–2, 8) NREL also
mentioned the efforts underway by
ASHRAE to develop a test method based
on multiple draw patterns that have
different total draw volumes that are
appropriate for water heaters of different
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66211
sizes. (NREL, No. 29 at p. 2) NEEA
likewise discussed these efforts by
ASHRAE. (NEEA, No. 27 at p. 2)
GTI discussed the effect of a greater
number of draws during the test on the
efficiency rating of instantaneous water
heaters, and presented data on
estimated energy factors and efficiencies
under different draw patterns. (GTI, No.
15 at pp. 6–9) NRCan discussed changes
being proposed to the committee
responsible for Canadian Standards
Association (CSA) P.3—Testing Method
for Measuring Energy Consumption and
Determining Efficiencies of Gas-Fired
Storage Water Heaters. The committee
is considering changing the current
draw pattern and replacing it with a
new pattern of 10 to 15 draws spread
throughout the day, with the volume
and time of each draw varying. NRCan
also provided data from a field study in
Ontario that included information on
hot water draw patterns. (NRCan, No. 16
at p. 2) NRDC urged DOE to examine the
existing data on draw patterns and to
conduct its own further testing if
necessary. (NRDC, No. 20 at p. 2) AET
commented that the draw patterns need
to be more realistic in terms of the
number of repeated small draws and
that it is important for tank-type,
instantaneous, and tankless water
heaters to all be rated using the same
draw patterns for a given capability
range, because comparisons among
them will otherwise have little meaning.
(AET, No. 22 at p. 2) ACEEE commented
that the current draw pattern is no
longer adequate for generating the
information that consumers need to
make wise purchasing decisions. In
ACEEE’s view, the six-draw test does
not reflect patterns seen in field studies
and that the current six-draw pattern is
inadequate, primarily because different
technologies that may lead to the same
energy use in typical applications
would get quite different EF ratings in
the lab. (ACEEE, No. 24 at p. 1)
Standards Committee 118.2 of ASHRAE
submitted minutes from a meeting held
on June 28, 2011, indicating that the
committee passed motions to develop
new draw patterns for a simulated-use
test. (ASHRAE, No. 25 at pp. 1–2)
Fifteen commenters supported the
implementation of different draw
patterns based upon water heater
capacities. Bradford White proposed
three different draw patterns that would
be applicable to water heaters of low
use, normal-to-high use, and heavy-duty
use. (Bradford White, No. 2 at pp. 5–6;
Bradford White, No. 30 at pp. 13–15)
PGE and SCE recommended that DOE
prescribe draw patterns based on ranges
of capacities of units or based upon
burner size for tankless units. (PGE, No.
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3 at p. 2; SCE, No. 4 at p. 2) Stone
Mountain Technologies stated that the
flow rate during individual draws and
the total volume drawn during the test
should be based on the hot water
delivery capacity of the model.
Furthermore, Stone Mountain
Technologies suggested that the
capacity should be based on the
theoretical volume of hot water that can
be delivered in 15 minutes using the
energy storage and the net heat input.
(Stone Mountain Technologies, No. 5 at
p. 2) AHRI and AO Smith recommended
that DOE should develop a simulateduse test that will vary for differing
models based on some specified
criterion such as storage volume or flow
rate or other appropriate characteristic.
(AHRI, No. 12 at p. 2; AO Smith, No. 8
at p. 2) NEEA indicated that its own
laboratory testing and that of some
others suggest that multiple draw
patterns (perhaps 3 to 5) would be
appropriate, depending on the capacity
of the water heater. (NEEA, No. 9 at p.
2) NRCan indicated that the CSA P.3
committee is considering 3 or 4
categories for daily hot water use
households: Low, medium, high, and,
potentially, a point-of-use category. The
water heaters would be categorized by
first-hour rating, maximum gallons per
minute, or maximum heat input.
(NRCan, No. 16 at p. 2) General Electric
commented that the draw pattern
should be proportionately scaled up for
large volume water heaters (greater than
50 gallon capacity) and, similarly,
scaled down for smaller water heaters
(less than 50 gallons). (GE, No. 21 at p.
2) ACEEE stated that DOE must use
different draw patterns for water heaters
of different capacities and suggested
that manufacturers should be allowed to
choose how a particular product is
rated. (ACEEE, No. 24 at p. 2) In
response to the January 2013 RFI, the
joint commenters recommended 5
different draw patterns for sizes ranging
from point-of-use to very high use
household/light commercial. The joint
commenters noted work by LBNL and
Stone Mountain Technologies in
devising a capacity rating based on
published storage volume and heat
source size. (Joint comment, No. 35 at p.
2) GE commented that water heaters
should be tested based on their capacity
as measured by the first-hour rating.
(GE, No. 36 at p. 1)
AHRI provided a suggested simulated
use test that described four different
draw patterns that would be applied to
a water heater based on its first-hour
rating or maximum flow rate
measurement. (AHRI, No. 46 at pp. 5–
6) As explained below, AHRI suggested
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cut-offs between the four different size
categories at first-hour ratings of 20, 55,
and 80 gallons and at maximum flow
rates of 1.5, 2.5, and 3.5 gallons per
minute; all values correspond to a
nominal outlet temperature of 135 °F
and a nominal inlet temperature of 58
°F. The draw patterns are based on a set
of activities that would be expected in
a typical residence, with the total
volume removed per day for the four
patterns being 15, 40, 64.2, and 82.75
gallons. The draw pattern for point-ofuse water heaters involved 11 draws,
while the other three draw patterns
involved 12 draws each. Flow rates
varied for each draw during the draw
pattern, except for the point-of-use draw
pattern which imposed a fixed flow rate
of 1 gallon per minute throughout the
test.
Applied Energy Technology
acknowledged the need to test a water
heater according to a draw pattern
appropriate for its delivery capacity, but
instead of supporting a suite of tests for
water heaters of different capacity, it
recommended that DOE consider a test
approach applicable to water heaters of
all sizes from which pieces of
information are obtained pertaining to
the particular capacity of the water
heater under test. AET’s suggested test
method entails a series of draw clusters
that simulate different end uses in a
residence. Water heaters with a high
capacity could presumably deliver
sufficiently hot water at all times during
the test, but water heaters with lower
capacity may fail to provide water at a
required temperature under those draw
clusters that called for large volumes of
hot water in a short time. Under AET’s
approach, a water heater would be rated
for those clusters during which it could
meet the demand placed upon it as
determined by the outlet temperature
during those draw clusters. (AET, No.
22 at pp. 18–37) AET commented that
details of the test method needed to be
refined, and no discussion was provided
as to how to use the efficiency
determined during each draw cluster for
which the water heater could meet the
demand to yield an energy factor.
DOE has tentatively concluded that
the current DOE test procedure’s draw
pattern applied during the simulateduse test can potentially yield results that
are biased towards particular waterheating technologies. The DOE test
procedure specifies a small number of
draws per day when compared to
typical usage, a relatively large time
between draws, and uniform volumes of
water per draw. The test procedure
applies to all water heater technologies
without regard to any inherent
differences in performance across the
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technologies. A revised draw pattern in
the simulated-use test that better reflects
how water is actually used in different
homes using different water heater
technologies could allow for a more
realistic representation of the expected
energy consumption consumers would
experience for a particular water heater
technology.
A test procedure that is completely
uniform across all water heater types
and sizes (i.e., no differences in the
amount of hot water drawn or the
number of draws, etc.) can provide
results that are biased toward different
water heater technologies. For electric
resistance and fossil fuel-fired storage
water heaters, the predominant factor
affecting the energy factor is the total
amount of water removed per day. At a
given set point temperature, the water
heater loses heat to the environment at
an essentially constant rate regardless of
the amount of water removed. Since the
energy factor is the ratio of hot water
energy delivered to the overall energy
consumed by the water heater, which is
a sum of that needed to heat the water
and that which is lost to the
environment, the energy factor increases
when the numerator of that ratio
increases. Hence, the energy factor
increases when the amount of water
delivered per 24 hours increases. The
performance of these water heaters is
not expected to depend upon the length
of draws, the flow rates of draws, nor
the spacing between the draws.
Storage water heaters that rely on heat
pump technology show the same
efficiency trend with overall delivered
water volume per day as seen with other
storage water heater technologies, but it
is also expected that the energy factors
would depend upon the way that water
is distributed among draws. A heat
pump water heater operates most
efficiently when the heat pump portion
of the water heater provides the heat to
the water as opposed to any backup
electric resistance heating. This backup
resistance heating is needed when the
hot water in the appliance is depleted
and a rapid amount of heat needs to be
delivered to raise the stored water
temperature back to the desired value.
Since heat pumps tend to have a low
heating rate, heat pump water heaters
currently on the market incorporate
resistance elements to provide that
rapid heating. These resistance
elements, however, dramatically reduce
the efficiency. In the current test
procedure, water heaters that have been
tested do not require backup electric
resistance heating to maintain an
adequate water temperature within the
tank since there is enough time between
draws for the tank to fully recover to a
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temperature that is above that which
triggers the resistance elements. If a
revised draw pattern would require a
larger amount of water to be drawn from
the water heater in a set period of time,
either through a single larger draw or
multiple draws spaced close together as
would be more representative of average
use, the heat pump water heater may be
forced to utilize electric resistance
heating to maintain the required tank
temperature, and the energy factor
would drop.
For small storage water heaters in the
‘‘point-of-use’’ category (water heaters
that generally are not intended to serve
as a single water heater for all uses in
a household), a test utilizing the current
draw pattern would likely result in
delivery of water during the draws that
is below a temperature that would be
considered useful by the resident. These
units have a small stored volume of hot
water that is appropriate for small uses
such as hand washing but not for a draw
of more than 10 gallons at 3 gallons per
minute (gpm), as is imposed by the
current test procedure. An efficiency
test that takes into account these
limitations should put a demand on the
water heater that calls for individual
draws less than those implemented in
the current DOE test.
Draw patterns and water heater
cycling frequency likely have an effect
on the measured efficiency of
instantaneous water heaters.
Instantaneous water heaters typically
use large burners or heating elements to
heat the water from the inlet
temperature to the outlet temperature as
it flows through the appliance. The
burner typically is not energized until a
water draw is initiated. Once the draw
stops, the burner is shut off, and the
remaining water in the appliance and
the material making up the appliance
gradually lose their heat and return to
the ambient temperature. This heat loss
(losses associated with heating up and
cooling off of the burner) is considered
a cycling loss, as the loss is associated
with the cycling on and off of the water
heater’s main energy input.
Draw patterns affect water heater
cycling and, thus, the overall measured
efficiency of the water heater. Shorter
draws typically act to lower the
measured efficiency because, as the
water heater cycles more frequently,
cycling losses increase. Further, cycling
losses account for a larger portion of
energy usage during shorter draws,
resulting in a disproportionate amount
of heat input going towards raising the
temperature of the heat exchanger as
opposed to raising the temperature of
the water. Hence, shorter draws
typically result in a lower measured
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efficiency. However, draws that are
clustered closer together typically act to
raise the measured efficiency by
reducing cycling losses because the
appliance may be able to maintain an
elevated temperature between the end of
one draw and the initiation of a
subsequent draw. The cycling losses are
mitigated by the fact that the appliance
does not cool down as much after the
end of one draw and thus does not need
to be heated as much when the
subsequent draw is initiated. Hence,
shorter spacing between draws typically
results in an increase in the water
heater’s measured efficiency.
The efficiency of instantaneous water
heaters is less affected by the total
volume of hot water delivered per day
than storage water heaters because their
standby losses (i.e., losses associated
with a water heater in standby mode,
independent of the cycling losses
discussed above) are negligible. Standby
losses increase measured energy
consumption without a corresponding
increase in energy delivered, thereby
decreasing the energy factor. An
increase in the volume of water
delivered per day results in a nearly
proportional increase in energy
consumption for instantaneous water
heaters. The other drivers of total energy
consumption are standby heat loss and
cycling heat loss, with standby heat loss
being essentially constant during the
test and cycling losses being a function
of the number of draws and their
spacing. As these two losses approach
zero, the dependence of energy factor on
daily draw volume decreases since the
energy consumption is dominated by
that needed to heat the water, which
vary proportionally. For water heaters
currently on the market, the cycling
losses experienced by instantaneous
water heaters tend to be much less than
the standby losses experienced by
storage water heaters. Because standby
losses increase measured energy
consumption without a corresponding
increase in energy delivered, the total
energy consumption for instantaneous
water heaters is much closer to the
energy needed to heat the water than
that seen with storage water heaters, and
the dependence on daily draw volume
is also lower.
The flow rate at which water is drawn
from the water heater may affect the
measured efficiency of an instantaneous
water heater. The heat transfer from the
heat exchanger to the water is a function
of the speed at which water moves
through the heat exchanger; efficiency
may increase at higher flow rates.
Additionally, since instantaneous water
heaters typically employ heating
elements or burners with variable
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capacity to meet the desired outlet
temperature at different flow rates, the
efficiency of the heat input device (e.g.,
burner or heating element) may also
vary depending upon the heating rate.
This effect could either increase or
decrease the overall efficiency
depending upon the setting to which the
heating element or burner is tuned.
To summarize, under the current DOE
test procedure, certain types of water
heaters can provide results that are
biased toward certain water heater
technologies. The small number of
draws imposed under the existing test
procedure, relative to the actual number
of draws noted in field usage data,
reduces the measured cycling losses
relative to those occurring in field
conditions. By contrast, the duration of
time between draws in the test
procedure is relatively long when
compared to field usage data, which
effectively increases the measured
cycling losses relative to those occurring
in field conditions. Water heaters with
low heating rates would appear to
benefit since they could easily recover
to operational temperature.
The current DOE test procedure does
not adequately measure energy
efficiency during a representative
average use cycle or period of use for
some technologies. The uniform volume
taken during each draw of the current
test method does not simulate highdemand use, such as a long shower, that
could change the way that a water
heater operates, nor does it simulate
performance under short draws during
which water is not delivered at the
prescribed set point temperature.
Furthermore, DOE agrees with
commenters who stated that the draw
patterns should be based on the delivery
capacity of the water heater because, as
explained above, the measured water
heater efficiency is influenced by the
draw pattern incorporated into the test
procedure and because a single draw
pattern is not appropriate for the range
of water heater sizes that fall under the
scope of this test procedure.
Consequently, DOE proposes a revised
simulated-use test that involves four
different draw patterns for water heaters
of different capacities. Water heaters
would be classified into the following
usage categories (described below)
corresponding to their usage capacity:
(1) Point-of-use; (2) low; (3) medium;
and (4) high. The proposed
classifications are based on delivery
capacity as determined in a first-hour
rating test for storage-type water heaters
or a maximum flow rate test for
instantaneous water heaters.
In crafting a proposed set of draw
patterns, DOE considered and utilized
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the recommended draw patterns
submitted by commenters, in particular
those submitted by Bradford White
(Bradford White, No. 2 at p. 3; Bradford
White, No. 30 at p. 11), AHRI (AHRI,
No. 46 at p. 3), and AET (AET, No. 22
at p. 1). (DOE notes that no test data
were supplied with any of the proposed
test methods.) Additionally, DOE
utilized data compiled by the LBNL 13
that describes field studies of hot water
usage to ensure that the draw patterns
were representative of field use. LBNL
found that typical usage in residences in
North America is characterized by a
large number of small volume draws, by
a smaller volume of water per day than
is currently prescribed in the residential
test method, and by a significant
variation in draw volume and number of
draws per day. The data suggest
development of a single typical draw
pattern would be difficult and
inappropriate. Instead, DOE has
attempted to develop several draw
patterns that capture key features
affecting performance (e.g., length and
frequency of draws, flow rates), while
maintaining a test that will not be overly
burdensome to conduct and which will
produce repeatable results.
Based upon this understanding, DOE
proposes the following draw patterns
containing volumes per day that are
consistent with the data found by LBNL.
The proposed low-use pattern calls for
the water heater to provide 38 gallons
per day, which is consistent with the
median values found for households
with 1 to 2 occupants. The proposed
medium-use pattern, which requires a
supply of 55 gallons per day, is
consistent with the median values
found for households with 3 to 4
occupants. The LBNL data show a
median volume of hot water used for
families with 5 or more occupants to be
approximately 58 gallons. This
unexpectedly low result might be
attributable to the lower sample number
of such large households. For this
reason, DOE has departed from the
LBNL field data and proposes a total
volume of 84 gallons per day for the
high-use pattern. This value is
consistent with that proposed by
Bradford White (Bradford White, No. 2
at p. 5) and AHRI (AHRI, No. 46 at p.
6), and DOE believes that it is a
representative number for high use
cases based on the range of hot water
usage per day reported by LBNL. While
13 Lutz, JD, Renaldi, Lekov A, Qin Y, and Melody
M., ‘‘Hot Water Draw Patterns in Single Family
Houses: Findings from Field Studies,’’ Lawrence
Berkeley National Laboratory Report number
LBNL–4830E (May 2011) (Available at https://
www.escholarship.org/uc/item/2k24v1kj) (last
accessed October 18, 2013).
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the LBNL report suggests that the
number of draws of hot water per day
could exceed 50, DOE has tentatively
determined that imposing a draw
pattern during a test with that many
draws could lead to measurement
difficulties owing to (1) the need to
measure energy removal in such short
draws; and (2) the potential variation
inherent in precisely controlling so
many draws. Accordingly, DOE has
tentatively concluded that a smaller
number of draws (ranging from 9 to 14)
will strike a balance between the need
to capture cycling losses associated with
water heater operation and the need for
accurate measurement. Additionally,
many of the short draws found in field
tests are clustered close together in time.
In these situations, cycling losses are
negligible because the water heater
remains at operational temperature over
the course of the smaller draws. For
these draws, energy efficiency can be
reliably estimated by consolidating the
multiple draws into a single larger draw.
As discussed in section III.F, ‘‘Test
Conditions,’’ DOE proposes that both
the first-hour rating test and the
maximum flow rate test will be carried
out with the prescribed outlet water
temperature at 125 °F. DOE proposes to
modify the first-hour rating test to stop
draws of hot water when the outlet
water temperature drops 15 °F below its
maximum temperature during each
draw. This cut-off temperature is a
departure from the current test, which
cuts off the draw when the outlet water
temperature drops 25 °F below the
maximum recorded outlet temperature.
With the nominal delivery temperature
being 135 °F in the current test
procedure, the cut-off temperature is
110 °F. This proposed change in
temperature drop to trigger the end of a
draw would maintain the approach that
the minimum useful temperature of hot
water is 110 °F. This value is consistent
with Table 3, Chapter 50 of the
ASHRAE Handbook of HVAC
Applications,14 which indicates that a
representative temperature for showers
and tubs is 110 °F. For water heaters
with rated storage volumes at or above
20 gallons, water will continue to be
drawn at 3 gallons per minute during
the first-hour rating test. For water
heaters having rated storage volumes
below 20 gallons that are not designed
to provide a continuous supply of hot
water, water will be drawn at a rate of
1 gallon per minute during the first-hour
rating test. A water heater that is
designed to provide a continuous
supply of hot water at the set point
temperature 15 will be tested to obtain a
maximum flow rate, while water heaters
that are not so designed will be subject
to a first-hour rating test.
DOE proposes the following ranges of
first-hour ratings and maximum flow
rates to characterize storage and
instantaneous water heaters,
respectively:
Point-of-use:
First-Hour Rating less than 20 gallons.
Maximum Flow Rate less than 1.7
gallons per minute (gpm).
Low:
First-Hour Rating greater than or
equal to 20 gallons, less than 55
gallons.
Maximum Flow Rate greater than 1.7
gpm, less than 2.8 gpm.
Medium:
First-Hour Rating greater than or
equal to 55 gallons, less than 80
gallons.
Maximum Flow Rate greater than or
equal to 2.8 gpm, less than 4 gpm.
High:
First-Hour Rating greater than or
equal to 80 gallons.
Maximum Flow Rate greater than or
equal to 4 gpm.
DOE based these proposed ranges (or
‘‘bins’’) on first-hour rating data for
existing models, requirements of the
current plumbing code, and
recommended cut-offs proposed by
Bradford White and AHRI. (Bradford
White, No. 2 at pp. 4–5; Bradford White,
No. 30 at p. 2; AHRI, No. 46 at p. 4) In
today’s NOPR, DOE proposes to modify
the set point temperature from the
current 135 °F to 125 °F, as discussed
further in section III.F.1. While it is
acknowledged that the published firsthour rating data were taken at a set
point temperature of 135 °F, limited
testing shows that first-hour ratings at a
set point temperature of 125 °F are
comparable to those at 135 °F. The firsthour ratings of all water heaters on the
market cluster around certain values to
accommodate different levels of use.
Those clusters are captured in the bins
proposed here. DOE’s proposed bins
differ from those presented by Bradford
White in its comments on the October
2011 RFI and the January 2013 RFI,
because the commenter’s approach
grouped medium-use and high-use
water heaters into a common category
and added a category for water heaters
meant for so-called ‘‘heavy-duty use.’’
(Bradford White, No. 2 at pp. 4–5) DOE
14 ASHRAE 2011, Handbook of HVAC
Applications, Chapter 50 Service Water Heating
(Available at: https://www.ashrae.org/resourcespublications/handbook).
15 A set point temperature is the temperature that
the user selects via a thermosat as the temperature
of the delivered hot water at the outlet of the water
heater.
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has tentatively concluded that the
categories defined by Bradford White
group too many water heaters in the
mid-use category. DOE’s proposed firsthour rating categories match those
proposed by AHRI. DOE believes that
these breakpoints are appropriate based
on minimum first-hour ratings required
by the Uniform Plumbing Code.16 The
code mandates minimum first-hour
ratings for water heaters serving homes
with different combinations of
bedrooms and bathrooms. Four different
minimum values are implemented by
the code: 42, 54, 67, and 80 gallons.
DOE has tentatively concluded that its
proposed usage categories are
appropriate, given that they are
consistent with the Uniform Plumbing
Code, albeit with certain minor
modifications. In considering the
Uniform Plumbing Code, DOE
considered 42 gallons per day as a lower
limit for the low-use category, but
concluded that it would not be realistic
for a water heater intended to provide
point-of-use functionality to deliver up
to that level of water in one hour.
Instead, DOE has tentatively decided to
set the upper limit for point-of-use
water heaters and the lower limit for
low-use water heaters at 20 gallons per
day. While water heaters with first-hour
ratings below 42 gallons per day may
not be used as a single water heater for
whole-house applications, DOE believes
that their use more closely resembles
that of low-use water heaters rather than
that of point-of-use water heaters. DOE
has grouped homes with 2 to 4
bedrooms and less than 3 bathrooms in
the medium category, which would
require minimum first-hour ratings of 54
or 67. Five bedroom homes with up to
2.5 bathrooms or homes with three or
more bathrooms would require water
heaters with first-hour ratings at least 80
gallons per day; these water heaters fit
into the proposed high-use category.
DOE acknowledges the uncertainty in
using data generated under the existing
test procedure, which are based on a
first-hour rating test conducted at a
delivery temperature of 135 °F, for
establishing bins for the applicable draw
patterns. Testing by DOE has indicated
that storage water heaters with relatively
16 International
Association of Plumbing and
Mechanical Officials, ‘‘2012 Uniform Plumbing
Code’’ (2012) (Available at www.iapmo.org) (last
accessed March 29, 2013).
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high recovery rates yield higher firsthour ratings under the proposed
procedure than under the current
procedure, while those with low
recovery rates tend to have slightly
lower first-hour ratings at 125 °F
compared to the rating at 135 °F. DOE
seeks comments related to the
translation of current first-hour ratings
to a first-hour rating determined using
the proposed 125 °F set point and the
proposed breakpoints between the
different size categories. This is
identified as issue 2 in section V.E,
‘‘Issues on Which DOE Seeks
Comment.’’
The proposed maximum gpm ratings
for instantaneous water heaters were
devised based on expected uses for
water heaters serving applications of
different sizes. The categorizations are
consistent with those suggested by
AHRI, with the ratings being scaled up
to account for the higher maximum flow
rates expected at the lower set point
temperature (125 °F).
DOE seeks comment on the proposed
criteria for characterizing water heaters
as point-of-use, low usage, medium
usage, and high usage, and whether
these criteria are appropriate and
sufficient. This is identified as issue 3
in section V.E, ‘‘Issues on Which DOE
Seeks Comment.’’
For each sizing category, DOE
proposes to apply a 24-hour simulateduse test to determine the energy factor.
One of four separate draw patterns
would be applied to each water heater
based on the appropriate sizing
category. The draw patterns would have
the following number of draws per day:
Point-of-use: 9; low: 11; medium: 12;
and high: 14. DOE acknowledges that
the number of draws per day in a typical
household can often approach 100 and
that the volume in each draw can be
very small. However, DOE believes that
a test with so many draws would be
subject to large variability in results due
to the challenges in accurately
determining the energy content of such
short draws. In contrast, DOE has
tentatively concluded that the proposed
draw patterns would capture the key
ways in which hot water is used in
residences while yielding a test that is
repeatable.
DOE’s proposal uses a slightly
modified version of the draw patterns
submitted by Bradford White and AHRI
in response to the January 2013 RFI as
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a basis for the low, medium, and high
draw patterns; Bradford White did not
submit a draw pattern for point-of-use
water heaters. In addition, the patterns
presented by Bradford White grouped
medium-use water heaters with heavy
use, so data were missing for both pointof-use and medium use water heaters.
Additionally, information provided by
AET has also been considered to craft
some aspects of the draw patterns. AET
provided information on typical uses
that would be applied to a water heater
in terms of flow rates, number of draws,
and volumes. (AET, No. 22 at pp. 22–
36) This information was utilized in
drafting the proposed draw patterns for
point-of-use and medium-use water
heaters.
A number of changes are proposed as
compared to the current draw patterns
found in the DOE simulated-use test
procedure. First, the proposed draw
patterns would involve more draws than
are currently implemented, and the
draws would vary in length during the
simulated-use test. Second, the spacing
between the draws would vary to better
capture the effects of different cycling
times on the energy efficiency of the
water heater. Third, the proposed draws
would involve different flow rates
during the test; these flow rates would
be 1.0, 1.7, or 3.0 gpm.17 The total
volumes that would be removed for
each category are in line with recent
field data compiled by the Lawrence
Berkeley National Laboratory that was
previously discussed. DOE believes that
the proposed draw patterns would
improve the estimation of energy
efficiency by considering the impact of
shorter draws, lower flow rates, higher
number of draws, and variable standby
times between draws.
DOE proposes draw patterns for
implementation in the 24-hour
simulated-use tests as outlined in Table
III.2 through Table III.5. The total
volume of water drawn in the proposed
draw patterns are 10 gallons for the
point-of-use pattern, 38 gallons for the
low-usage pattern, 55 gallons for the
medium-usage pattern, and 84 gallons
for the high-usage pattern.
17 For point-of-use models, the flow rate is
specified as the lesser of 1 gpm or the maximum
gpm. Therefore, if a unit were to have a maximum
gpm rating below 1.0 gpm, that unit would be tested
at its maximum gpm flow rate.
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TABLE III.2—POINT-OF-USE DRAW PATTERN
Time during
test
(hh:mm)
Draw number
1
2
3
4
5
6
7
8
9
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
.......................................................................................................................
Volume
(gallons)
0:00
1:00
1:05
1:10
1:15
8:00
8:15
9:00
9:15
Flow rate
(gpm)
2
1
0.5
0.5
0.5
1
2
1.5
1
Lesser
Lesser
Lesser
Lesser
Lesser
Lesser
Lesser
Lesser
Lesser
of
of
of
of
of
of
of
of
of
(1,
(1,
(1,
(1,
(1,
(1,
(1,
(1,
(1,
max
max
max
max
max
max
max
max
max
gpm).
gpm).
gpm).
gpm).
gpm).
gpm).
gpm).
gpm).
gpm).
TABLE III.3—LOW-USAGE DRAW PATTERN
Time during
test
(hh:mm)
Draw number
1 ...................................................................................................................................................
2 ...................................................................................................................................................
3 ...................................................................................................................................................
4 ...................................................................................................................................................
5 ...................................................................................................................................................
6 ...................................................................................................................................................
7 ...................................................................................................................................................
8 ...................................................................................................................................................
9 ...................................................................................................................................................
10 .................................................................................................................................................
11 .................................................................................................................................................
0:00
0:30
1:00
10:30
11:30
12:00
12:45
12:50
16:15
16:45
17:00
Volume
(gallons)
15.0
2
1
6
4.0
1.0
1.0
1.0
2.0
2.0
3.0
Flow rate
(gpm)
1.7
1
1
1.7
1.7
1
1
1
1
1.7
1.7
TABLE III.4—MEDIUM-USAGE DRAW PATTERN
Time during
test
(hh:mm)
Draw number
1 ...................................................................................................................................................
2 ...................................................................................................................................................
3 ...................................................................................................................................................
4 ...................................................................................................................................................
5 ...................................................................................................................................................
6 ...................................................................................................................................................
7 ...................................................................................................................................................
8 ...................................................................................................................................................
9 ...................................................................................................................................................
10 .................................................................................................................................................
11 .................................................................................................................................................
12 .................................................................................................................................................
0:00
0:30
1:40
10:30
11:30
12:00
12:45
12:50
16:00
16:15
16:45
17:00
Volume
(gallons)
15
2.0
9.0
9.0
5.0
1.0
1.0
1.0
1.0
2.0
2.0
7.0
Flow rate
(gpm)
1.7
1
1.7
1.7
1.7
1
1
1
1
1
1.7
1.7
TABLE III.5—HIGH-USAGE DRAW PATTERN
Time during
test
(hh:mm)
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Draw number
1 ...................................................................................................................................................
2 ...................................................................................................................................................
3 ...................................................................................................................................................
4 ...................................................................................................................................................
5 ...................................................................................................................................................
6 ...................................................................................................................................................
7 ...................................................................................................................................................
8 ...................................................................................................................................................
9 ...................................................................................................................................................
10 .................................................................................................................................................
11 .................................................................................................................................................
12 .................................................................................................................................................
13 .................................................................................................................................................
14 .................................................................................................................................................
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0:00
0:30
0:40
1:40
10:30
11:30
12:00
12:45
12:50
16:00
16:15
16:30
16:45
17:00
04NOP3
Volume
(gallons)
27
2.0
1
9.0
15
5.0
1.0
1.0
1.0
2.0
2.0
2.0
2.0
14.0
Flow rate
(gpm)
3
1
1
1.7
3
1.7
1
1
1
1
1
1.7
1.7
3
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Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
For instantaneous water heaters with
maximum flow rates less than 1 gpm,
DOE proposes that the flow rates during
all draws of the point-of-use test will be
set at the maximum gpm as determined
during that test. DOE also proposes to
tighten the tolerance on the volume
removed in each draw from 0.5 gallons
to 0.25 gallons since these patterns
involve smaller draw volumes than in
the current procedure.
DOE proposes to utilize interim
metrics during testing that would be
used in calculations to normalize the
test to standard conditions, as in the
current test procedure, to account for
deviations from the prescribed storage
tank temperature, ambient temperature,
water delivery temperature, and inlet
water temperature. The standby loss
coefficient is one interim metric that
would be determined during the longest
standby portion of each test in which no
recovery or draws are taking place. The
recovery efficiency is a second interim
metric that would be determined based
on the first draw of each test, with the
energy supplied and consumed during
subsequent draws being accounted for
when a complete recovery does not
occur prior to the second draw.
DOE proposes to abandon the
determination of recovery efficiency at
different flow rates as currently done for
instantaneous water heaters; test data
have shown the difference between
these recovery efficiencies as being less
than five percent, and the resulting
effect on the energy factor is negligible.
DOE notes that the proposed draw
patterns differ slightly from those
suggested by AHRI in response to the
January 2013 RFI. (AHRI, No. 46 at pp.
5–6) In DOE’s view, the proposed draw
patterns appropriately differentiate
between the size categories by
increasing the number of draws as the
size of the water heater increases. DOE
also intends to minimize the different
number of flow rates required for all
tests, with the proposed draw patterns
involving three different flow rates as
opposed to the four specified by AHRI.
The patterns proposed here have also
been formulated to allow for the
determination of key performance
metrics that are needed for computing
the energy factor, namely recovery
efficiency and standby loss coefficient.
DOE believes that the proposed patterns
will ease those determinations. Finally,
DOE has conducted testing according to
the proposed patterns to validate the
procedure and make adjustments as
needed, whereas AHRI has not
indicated that its specific patterns
presented have been validated. In any
event, DOE has tentatively concluded
that the draw patterns proposed in
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today’s NOPR are very similar to the
patterns proposed by AHRI, and that
little difference will be observed
between ratings collected from either
draw pattern. This assessment is based
on the fact that the total volumes drawn
per day for each category are
comparable, the number of draws per
day is comparable, and each pattern is
based on a distribution that represents
a cluster of draws in the morning and
another cluster in the evening hours.
Consequently, DOE has tentatively
concluded that the patterns proposed in
this NOPR are consistent with those
presented by AHRI. DOE seeks comment
on whether the proposed draw patterns
for the different water heater size
categories are appropriate. This is
identified as issue 4 in section V.E,
‘‘Issues on Which DOE Seeks
Comment.’’
D. Instrumentation
DOE proposes to maintain the
instrumentation installation
requirements and piping configuration
as currently specified in the residential
water heater test procedure. Bradford
White recommended that the internal
temperature probe required in the
current test procedure be eliminated
and that all exposed piping on the inlet
and outlet of the water heater be
eliminated as much as possible.
(Bradford White, No. 30 at p. 2) DOE is
concerned that the removal of the
internal temperature probe would not
enable the critical correction for stored
energy inside the water heater, a value
that could move the energy factor by
several points. For this reason, DOE
proposes to maintain the internal
temperature probe inside the tank of a
storage water heater. DOE is also
proposing to maintain the piping
configuration as currently specified in
the residential water heater test
procedure, as some water heaters
include particular technologies such as
heat traps that minimize losses through
piping connections. For storage water
heaters having a rated volume below 20
gallons, which are not covered in the
existing DOE test method, DOE
proposes that the average tank
temperature would be determined based
on three temperature sensors located
within the storage tank as opposed to
the currently required six sensors for
storage water heaters having a rated
volume above 20 gallons. The three
sensors would be located at the vertical
midpoints of three sections of equal
volume within the tank. For these units,
DOE believes that three sensors are
sufficient for determining the mean tank
temperature and that the use of six
sensors would provide little extra
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information and may add to the
parasitic heat losses from these smaller
units.
DOE proposes to tighten the allowed
accuracy on electric power and energy
measuring equipment from the current
value of ± 1 percent to ± 0.5 percent. A
study has shown the significant effect of
the accuracy of the electric power
measurements on the uncertainty in the
overall energy factor.18 An analogous
change was made in ASHRAE 118.2–
2006, ‘‘Method of Testing for Rating
Residential Water Heaters,’’ and DOE
research confirms that equipment
having this tolerance level can be
readily procured. DOE also proposes to
require that for mass measurements
greater than or equal to 10 pounds (4.5
kg), a scale that is accurate within ± 0.5
percent of the reading be used to make
the measurement.
DOE also proposes to modify the data
acquisition rate of the inlet and outlet
water temperature during draws.
Currently, for all water heaters except
variable firing rate instantaneous water
heaters, temperature data measurements
are taken at 5-second intervals starting
15 seconds after the draw commences.
For instantaneous water heaters with a
variable firing rate, temperature data
measurements are taken at 5-second
intervals starting 5 seconds after the
draw commences. The proposed test
procedure amendments call for
temperature data at the inlet and outlet
temperature sensors to be recorded at 3second intervals starting 5 seconds after
commencement of the draw for all water
heaters. Accordingly, DOE also proposes
to require that the time constant of the
instruments used to measure the inlet
and outlet water temperatures be no
greater than 2 seconds. DOE anticipates
that this approach would better capture
the energy impact of water heater startup and cycling.
E. Discrete Performance Tests
In the October 2011 RFI, DOE
considered using a series of discrete
tests as an alternative approach to using
a single 24-hour simulated-use test to
determine the energy factor of
residential water heaters. In a series of
discrete performance tests, the results of
various individual tests (e.g., thermal
efficiency test, recovery efficiency test,
standby loss test) would be used to
calculate the energy factor. This
approach would reduce testing burden,
yield more repeatable results, and
provide the ability to predict
18 Healy WM, Lutz JD, and Lekov AB.,
‘‘Variability in Energy Factor Test Results for
Residential Electric Water Heaters,’’ HVAC&R
Research, vol. 9, No. 4 (October 2003).
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performance over a broader range of
applications. DOE requested comments
on the feasibility and equitability of a
series of discrete tests in the October
2011 RFI. 76 FR 63211, 63214 (Oct. 12,
2011).
Two commenters (ACEEE, NREL)
supported the general premise of
discrete performance tests for rating
water heaters, while acknowledging the
challenges in implementing such an
approach. More specifically, NREL
indicated that studies are needed to
validate that discrete tests would
provide a computed energy factor with
a level of accuracy equal to or better
than a single simulated-use test. (NREL,
No. 14 at p. 5) ACEEE indicated that
discrete tests combined with an
algorithm to determine the energy factor
could reduce test time, produce ratings
at a variety of usage patterns with a
single set of tests, and could be used to
account for novel features implemented
by manufacturers to improve efficiency.
ACEEE also acknowledged that the
algorithms would still need to be
developed and validated, a process with
an unknown time frame. (ACEEE, No.
24 at pp. 2–3)
Eleven commenters (Stone Mountain
Technologies, AO Smith, NEEA, NPGA,
AHRI, AGA, GTI, Bosch, NRDC, General
Electric, and AET) opposed the use of
discrete tests to determine the energy
factor. AHRI and AO Smith stated that
such tests have a limited use relative to
the wide range of technologies being
employed in current designs of
residential water heaters since they
would not be as equitable as a
simulated-use approach. (AHRI, No. 12
at p. 2; AO Smith, No. 8 at p. 2) GTI
commented that much uncertainty
remains in the analytical methodology
for generating rating metrics, its
comparability across equipment
categories, and whether the outcome
would actually yield a simpler and more
repeatable alternative to the current test
procedure. (GTI, No. 15 at p. 2) Stone
Mountain Technologies stated that
testing and analysis to date do not
support such an approach. (Stone
Mountain Technologies, No. 5 at p. 3)
Bosch expressed support for the current
draw profile and test approach because
of what the commenter perceives as the
extremely low repeatability and
accuracy of test results at low input
rates and the lack of data on appropriate
draw patterns for use in calculating the
energy factor. (Bosch, No. 17 at p. 2)
General Electric expressed support for
the current draw profile and test
approach, arguing that it would more
accurately focus on actual results and
more closely approximate the real-world
performance of residential water
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heaters. (GE, No. 21 at pp. 1–2) NEEA
stated that the concept of using discrete
performance tests to determine energy
factor is not practical. (NEEA, No. 9 at
p. 3) AGA commented that discrete
performance tests have been shown to
develop inconsistent results and impose
new uncertainties in testing, and NRDC
raised questions about the equitability
of testing between technology types.
(AGA, No. 13 at pp. 1–2; NRDC, No. 20
at p. 2) AET stated that it does not
believe that the approach would work in
practice because of controls not working
as designed, the presence of multiple
operating modes on water heaters, and
the need to conduct more
characterization tests than initially
expected. These issues with discrete
performance tests would make the
algorithms used to obtain an energy
factor prone to error. (AET, No. 22 at pp.
5–6)
DOE has decided not to pursue the
use of discrete performance tests for
rating the energy efficiency of
residential water heaters given the
potential inequity in test results across
technologies, the added uncertainties in
ratings, and the general lack of
potentially suitable algorithms to
develop an energy factor for water
heaters. Rather, as discussed previously
in section III.C, DOE is maintaining the
single simulated-use test, which DOE
believes can be a more, technologyblind method for determining the
energy efficiency (EF) of water heaters.
F. Test Conditions
1. Water Delivery Temperature
The current residential water heater
test procedure calls for average hot
water temperature within the storage
tank to be set for delivery at 135 °F ±
5 °F (57.2 °C ± 2.8 °C). 10 CFR part 430,
subpart B, appendix E, section 2.4.
However, DOE noted in the October
2011 RFI that the Underwriters
Laboratories (UL) standards specify that
manufacturers must ship residential
water heaters with thermostats set at
temperatures no greater than 125 °F (52
°C) to safeguard against scalding hazards
(UL 174, Standard for Household
Electric Storage Tank Water Heaters,
Underwriters Laboratories (April 29,
2004)). DOE also noted that DOE’s own
research suggests that although the
majority of water heaters are shipped
with the thermostat preset to 120 °F (49
°C), the average set point in use in the
field is 124.2 °F (51.2 °C), suggesting
that some homeowners or installers
adjust the thermostat. 76 FR 63211,
63214 (Oct. 12, 2011).
The set point impacts the
performance of various types of water
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heaters differently, and as a result, DOE
reexamined the appropriateness of the
set point specification in the proposed
test procedure. As noted in the October
2011 RFI, a higher delivery temperature
has a disproportionately large and
negative impact on heat pump water
heater efficiency (as compared to other
types of water heaters), because heat
pump water heaters can have markedly
different performance at elevated stored
water temperature compared to
temperatures more representative of
typical residential usage. For other types
of water heaters, heat transfer
characteristics between the heating
source and the water may differ at lower
delivery temperatures, thereby affecting
the efficiency. 76 FR 63211, 63214 (Oct.
12, 2011).
However, DOE also noted in the
October 2011 RFI that there are some
concerns with using a lower set point
temperature in the test procedure: (1)
Some end uses (e.g., dishwasher
operation) require hot water delivered at
130 °F to 140 °F (54 °C to 60 °C) for
effective operation; and (2) there may be
the potential for the growth of
Legionella in hot water stored below
135 °F (57 °C).19
DOE sought comment on the
appropriate set point temperature for
the residential water heater test
procedure and the benefits and concerns
with using a lower temperature. Three
commenters to the October 2011 RFI
(Bradford White, Bosch, and General
Electric) recommended that the set
point temperature should be kept at its
current value of 135 °F (57 °C).
Additionally, two commenters on the
January 2013 RFI also recommended
maintaining the set point at 135 °F (57
°C). (Bradford White, No. 30 at p. 2;
AHRI, No. 46 at p. 2) Bosch stated that
this value will maintain harmonization
with test standards in Canada. General
Electric indicated that plumbers may
change the set point, but a lower
temperature in the test procedure runs
the risk of encouraging consumer
dissatisfaction with water heaters that
are otherwise properly sized for their
household due not to lack of capacity,
but to lack of properly adjusted storage
temperatures. Additionally, General
Electric indicated that DOE runs the risk
19 ASHRAE Guideline 12, ‘‘Minimizing the Risk of
Legionellosis Associated with Building Water
Systems,’’ states that the temperature range most
favorable for amplification of legionellae bacteria is
770¥108 0F (250¥42 0C), and that document
recommends that when practical, hot water should
be stored at temperatures of 120 0F (49 0C) or above.
However, the guideline also states that for high-risk
situations (such as in health care facilities and
nursing homes), hot water should be stored above
140 0F (60 0C). For more information visit:
www.ashrae.org.
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of encouraging energy inefficiency in
actual use at higher set points of water
heaters designed and optimized to test
procedures at lower set points.
(Bradford White, No. 2 at p. 2; Bosch,
No. 17 at p. 2; GE, No. 21 at pp. 2–3)
In submitting a suggested test method,
AHRI noted that it considered lower set
points but that its recommendation is to
continue to use 135 °F as the set point
in the test. AHRI indicated that its
recommended draw patterns should be
modified if DOE determines that a
different set point temperature setting is
appropriate. (AHRI, No. 46 at p. 2)
Thirteen comments were submitted
that recommended that the set point
temperature be lowered from its current
value. PGE, SCE, NREL, AET, and
ACEEE recommended a set point
temperature of 120 °F (PGE, No. 3 at p.
2; SCE, No. 4 at p. 2; NREL, No. 14 at
p. 4; AET, No. 22 at p. 3; ACEEE, No.
24 at p. 4), while NEEA recommended
a value of 125 °F. (NEEA, No. 9 at p. 3;
NEEA, No. 37 at p. 4) In a comment on
the January 2013 RFI, the joint
commenters supported a set point
temperature between 120 °F and 125 °F.
(Joint comment, No. 35 at p. 3)
Likewise, Stone Mountain Technologies
and NRDC recommended a set point
between 120 °F and 125 °F. (Stone
Mountain Technologies, No. 5 at p. 3;
NRDC, No. 20 at p. 2) AHRI and AO
Smith did not suggest a specific value,
but recommended that the set point
temperature be lowered. (AHRI, No. 12
at p. 2; AO Smith, No. 8 at p 2) AET
commented that the proposed ASHRAE
Standard 188, (Standard 188P),
‘‘Prevention of Legionellosis Associated
with Building Water Systems,’’ and
ASHRAE Guideline 12, ‘‘Minimizing the
Risk of Legionellosis Associated with
Building Water Systems,’’ are reexamining recommendations for
preventing the growth of Legionella.
AET stated that water temperatures in
the range of 120 °F are adequate to
prevent Legionella colonies, provided
that the water is maintained at a
temperature ‘‘high enough, long enough,
and often enough.’’ (AET, No. 22 at pp.
11–12)
AET commented that the test
procedure should allow for variable
delivery temperatures, because some
point-of-use water heaters are designed
to deliver water no hotter than 105 °F
(40.6 °C) to 110 °F (43.3 °C). AET argued
that no credit should be given to water
delivered at temperatures above the set
point temperature, in order to
discourage temperature overshoots.
Likewise, AET argued that no credit
should be given to water delivered at a
temperature below that which is
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considered useful to the user (i.e., below
105 °F (40.6 °C)). (AET, No. 22 at p. 13)
After carefully considering these
comments, DOE proposes to lower the
set point temperature of residential
water heaters in the test procedure to
125 °F. This value was primarily
selected based on data available in
DOE’s analysis for the April 2010 energy
conservation standards final rule as
previously discussed, which found that
the average set point temperature for
residential water heaters is 124.2 °F
(51.2 °C). Additionally, the recent
compilation of field data across the
United States and southern Ontario by
LBNL previously referenced found a
median daily outlet water temperature
of 122.7 °F (50.4 °C); this value rounded
to the nearest 5 °F increment supports
a test set point temperature of 125 °F.
This new value would apply to firsthour rating tests for storage water
heaters, maximum flow rate tests for
instantaneous water heaters, and energy
factor tests for all water heaters.
DOE appreciates the comment from
AET regarding the new proposed
guidelines for Legionella prevention,
and tentatively concludes that a set
point of 125 °F in the test method would
not result in safety concerns related to
the growth of Legionella. Further, as
discussed immediately above, DOE
notes that water heaters are commonly
set to temperatures in the range of 120
°F to 125 °F even though the current set
point in the test method is 135 °F. DOE
does not expect consumer behavior
related to set points to change if the set
point is lowered in the test method.
For first-hour rating tests, DOE
proposes that draws would terminate
when the outlet temperature drops 15 °F
(8.3 °C) from its maximum outlet
temperature during the draw, as
opposed to the drop of 25 °F (13.9 °C)
implemented in the current test
procedure. This change would ensure
that water delivered meets the nominal
useful temperature of 110 °F (43.3 °C).
DOE acknowledges that the Canadian
test procedure requires testing at 135 °F
(57 °C), but DOE is responsible for
developing a water heater test procedure
that reflects and is appropriate for the
United States market. In response to
comments indicating that DOE should
retain the 135 °F set point temperature,
DOE believes that the test should be
conducted at typical operating
temperatures and should not penalize
those units optimized for such typical
conditions.
GE commented that the set point
temperature should be based upon the
outlet water temperature as opposed to
the average stored water temperature to
allow newer technologies to be included
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66219
in the protocol and to achieve the goal
of being technology-neutral. (GE, No. 36
at p. 2) HTP made a similar assertion
that the set point should not be based
on the mean tank temperature, noting
that requiring a mean tank temperature
could penalize condensing gas water
heaters that rely on stratification and
cooler water at the bottom of the tank
to achieve better heat transfer resulting
in the condensation of moisture within
the flue gases. (HTP, No. 41 at p. 2) Due
to these concerns, AHRI suggested an
alternative method for setting the
thermostat. Instead of setting the
thermostat based on the mean tank
temperature as determined by the
internal tank temperature probe, AHRI
suggested that the thermostat setting
should be determined by drawing water
from the water heater for several
minutes to determine if the set point
temperature is achieved. (AHRI, No. 46
at p. 5) AHRI proposed that the flow rate
at which the water would be drawn
during this procedure to set the
thermostat would be 1 gpm for point-ofuse water heaters and 1.7 gpm for all
other size storage water heaters.
DOE agrees in principle with the
comments and the suggested approach
presented by AHRI for setting the
thermostat. After carefully considering
these comments, DOE acknowledges
that the current method for setting the
thermostats of water heaters that rely on
stratification may lead to outlet water
temperatures significantly higher than
would normally be expected in practice,
since the top of the water heater needs
to be at an elevated temperature
compared to the mean temperature to
meet the requirement that the mean
temperature fall within the value
specified in the test procedure.
However, DOE is not aware of a simple
method to assure that multiple
thermostats are set appropriately by
monitoring outlet water temperature
during a draw.
As a result, DOE proposes a method
for determining the appropriate set
point temperature that differs slightly
from that proposed by AHRI. DOE
proposes to apply the thermostat setting
procedure that utilizes the outlet
temperature during a draw, as suggested
by AHRI, only to water heaters having
a single thermostat. For water heaters
with multiple thermostats, DOE
proposes to maintain the procedure
currently prescribed in the residential
water heater test method which utilizes
the internal tank temperature probes to
determine if the water heater thermostat
is set properly. DOE is not aware of any
technologies that rely on stratification
that utilize multiple thermostats, so it
believes that the current approach for
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setting the thermostat is appropriate for
water heaters having multiple
thermostats. DOE is also proposing to
make a clear distinction by rated
volume between those water heaters
using a lower flow rate during this test
compared to those using a higher flow
rate since the thermostat setting will
need to be done prior to the
experimental determination of whether
the water heater is to be considered a
point-of-use water heater. While making
this adjustment, DOE is maintaining
calculations to normalize the standby
loss to a mean tank temperature of 125
°F ± 5 °F (51.7°C ± 2.8 °C) to ensure
equitable comparison between water
heaters.
DOE is interested in receiving
comments on both the proposed set
point temperature of 125 °F ± 5 °F, and
the proposed approach to setting the
thermostat for storage water heaters,
particularly on the appropriateness of
different methods for water heaters
having a single thermostat compared to
those with multiple thermostats. These
are identified as issues 6 and 7 in
section V.E, ‘‘Issues on Which DOE
Seeks Comment.’’
2. Ambient Temperature and Relative
Humidity
The residential water heater test
procedure requires that testing be
performed in an environment with an
ambient air temperature fixed at 67.5 °F
± 2.5 °F (19.7 °C ± 1.4 °C). 10 CFR part
430, subpart B, appendix E, section 2.2.
For heat pump water heaters, however,
the environmental conditions are more
tightly constrained with an ambient air
temperature requirement of 67.5 °F ± 1
°F (19.7 °C ± 0.6 °C) and a relative
humidity requirement of 50 percent ± 1
percent. Id. These specifications for heat
pump water heaters reflect the fact that
heat pump water heater energy use is
highly dependent on the ambient
temperature and relative humidity.
Because water heaters are placed in a
wide variety of locations within and
outside of a home, and given the large
impact of these factors on heat pump
water heater efficiency, DOE considered
potential revisions to the ambient air
test conditions set forth in the DOE test
procedure in order to assess whether the
currently-specified conditions are
representative of conditions typically
encountered in residential installations.
In the October 2011 RFI, DOE requested
comment on the appropriate ambient
temperature and relative humidity
testing points and tolerances for all
types of residential water heaters. 76 FR
63211, 63214–15 (Oct. 12, 2011).
DOE received seven comments
(Bradford White, Stone Mountain
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Technologies, AO Smith, AHRI, Bosch,
General Electric, and AET) that
supported the current ambient
temperature and relative humidity
conditions. Bradford White suggested
that DOE should consider relaxing the
tolerances for temperature and relative
humidity when testing heat pump water
heaters since it is very difficult to
control to those conditions,
recommending that the allowable
ambient temperature variation be ± 2.5
°F and the allowable variation in
relative humidity be ± 5 percent.
(Bradford White, No. 2 at p. 2; Stone
Mountain Technologies, No. 5 at p. 3;
AO Smith, No. 8 at p. 2; AHRI, No. 12
at p. 2; Bosch, No. 17 at p. 2; GE, No.
21 at p. 3; AET, No. 22 at p. 4)
NEEA submitted for DOE
consideration as a test method a test
plan that has been implemented in the
Pacific Northwest in which heat pump
water heaters are tested at both the
current DOE specifications and at a
second point with the ambient
temperature at 50 °F (10 °C) and the
relative humidity at 58 percent. A binweighted calculation using these two
points would yield an energy factor, and
NEEA stated that it believes that these
conditions are more appropriate than
the current ones for installations in the
northern half of the United States and
would lead to better estimates of the
actual performance in the field. (NEEA,
No. 9 at p. 3) NEEA reiterated the desire
to test at multiple conditions in
response to the January 2013 RFI.
(NEEA, No. 37 at p. 5) NRDC indicated
that the conditions need to be reexamined but did not offer any
suggestions. (NRDC, No. 20 at p. 2)
ACEEE suggested that DOE should
evaluate changing the ambient
temperature to 50 °F or other such value
that approximates the national average
winter basement temperature. (ACEEE,
No. 24 at p. 3) Davis Energy Group
presented data from a survey of homes
in California that reported average
ambient temperatures that ranged from
65.4 °F to 71.7 °F. (Davis Energy Group,
No. 6 at p. 1)
After carefully considering these
comments, DOE proposes to maintain
the current ambient dry bulb
temperature of between 65 °F and 70 °F
when testing water heaters other than
heat pump water heaters and at 67.5 °F
± 1 °F when testing heat pump water
heaters. DOE also proposes to maintain
relative humidity at 50 percent, but to
relax the tolerances to ± 2 percent
relative humidity. DOE believes these
conditions are generally representative
of typical field conditions encountered
by water heaters installed in the U.S.
and has not found any data to justify
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changing these conditions. DOE
proposes to relax the tolerance for
relative humidity because research
indicates that commonly-used,
laboratory-grade relative humidity
sensors have uncertainties on the order
of 1 to 1.5 percent. For this reason, the
tolerance cannot be expected to be
below the accuracy in measuring that
value. It should be noted, however, that
the relative humidity can be obtained
from measurements of dry bulb and wet
bulb temperatures, and the
determination of relative humidity
through these temperature
measurements would result in a
measure of relative humidity with much
lower uncertainty since dry bulb and
wet bulb temperatures can be measured
with high accuracy. However, most
laboratories use relative humidity
sensors which provide an accurate but
less burdensome method for measuring
relative humidity. DOE is also
proposing to add a statement to the
instrumentation section that specifies
that the accuracy of relative humidity
sensors shall be within ± 1.5 percent
relative humidity.
3. Laboratory Airflow
The existing test procedure specifies
that the water heater shall be set up in
an area that is protected from drafts. To
clarify this statement, DOE proposes to
add a stipulation that the area be
protected from drafts of more than 50 ft/
min (2.5 m/s). This value is in
accordance with specifications in
Canadian Standard 745–03, ‘‘Energy
Efficiency of Electric Storage Tank
Water Heaters and Heat Pump Water
Heaters.’’
G. Annual Energy Consumption
Calculation
The annual energy consumption is
calculated for residential water heaters
in the existing test procedure based on
the daily energy consumption
multiplied by 365 days. In a letter
submitted to the FTC on September 16,
2013, regarding the labeling of
residential water heaters, AHRI pointed
out that calculating the annual energy
consumption based on the daily energy
consumption can lead to differing
annual energy consumption, and
consequently, differing estimated yearly
operating costs, for water heater models
with the exact same EF rating. AHRI
specifically provided an example of two
water heaters with differing daily energy
consumption values, but with EF values
that would round to the same value
based on the DOE rounding
requirements provided in 10 CFR
430.23(e). AHRI stated that having
slightly different yearly operating cost
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estimates for two water heaters with the
same efficiency rating can be confusing
to consumers, and somewhat misleading
based on the accuracy of the test
method. AHRI suggested revising the
calculation of the annual energy
consumption so that it is based on the
EF rating.
DOE agrees with AHRI regarding the
calculation of the annual energy
consumption and the accuracy of the
test method. As a result, DOE proposes
to adopt the calculation method
suggested by AHRI for annual energy
consumption, which is based on the
nominal energy consumed during the
test and the energy factor rating, rather
than the daily energy consumption.
H. Conversion of Existing Energy Factor
Ratings
The proposed test procedure
amendments could result in some types
of water heaters reporting some
numerical changes in EF due to the
proposed changes in the draw pattern,
set point temperature, and water
delivery temperature. However, the
extent of change can vary across the
numerous design types of water heaters
and, perhaps more importantly, within
a given design type. This variability
makes it difficult to capture the effect of
the proposed test procedure
amendments by a consistent, systematic
adjustment to the current test
procedure.
Foreseeing these circumstances,
AEMTCA amended EPCA to require that
along with the uniform descriptor, DOE
must develop a mathematical
conversion factor to translate from the
existing metrics to the uniform
descriptor. (42 U.S.C. 6295(e)(5)(E))
AEMTCA provided that a manufacturer
may apply the conversion factor to
rerate existing models of covered water
heaters that are in existence prior to the
effective date of the final rule
establishing the uniform descriptor.
Further, the conversion factor must not
affect the minimum efficiency
requirements for covered water heaters,
and, as a result, would not lead to a
change in measured energy efficiency
for existing products. DOE interprets
these requirements to mean that DOE
will be required to translate existing
ratings from the current metrics to the
new metric, while maintaining the
stringency of the current standards. In
the January 2013 RFI, DOE sought
comment on the best approach for this
conversion factor. 78 FR 2340, 2345
(Jan. 11, 2013).
NREL stated that there is not a simple
conversion factor that will work across
all systems, but it provided a list of
references with validated algorithms
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that could assist DOE in developing
these conversion factors. (NREL, No. 29
at p. 4) AHRI and AO Smith commented
that DOE should not simply test
multiple units to determine an average
difference between the current and new
ratings and use that value to convert the
ratings. (AHRI, No. 33 at p. 4; AO Smith,
No. 34 at p. 3) The joint commenters
supported the use of a ‘‘good-enough’’
mathematical conversion method to
express existing ratings in terms of the
new uniform descriptor and urged DOE
to test a sample of existing products to
validate the algorithmic conversion
method. (Joint comment, No. 35 at p. 4)
Considering the limited laboratory
capacity to test all water heaters under
the revised method of test, NEEA
commented that DOE should assume
that all water heaters that comply with
current standards will also comply after
the implementation of the new metrics.
(NEEA, No. 37 at p. 6) EEI commented
that the conversion factor should not
make currently existing standards more
stringent and should only be based on
point-of-use metrics to be consistent
with Federal law. (EEI, No. 40 at p. 2)
HTP commented that the most exact
approach would be to conduct an
empirical analysis using curve fitting to
actual test data, although the commenter
acknowledged that there is not
sufficient time for manufacturers to
obtain this information and for the
Department to then correlate and
analyze the data. (HTP, No. 41 at p. 3)
DOE notes these comments regarding
the conversion factor and will consider
them fully once the test procedure is
finalized to assist in developing the
conversion factor. DOE plans to conduct
a separate rulemaking to establish the
conversion factor once the test method
is finalized, and in that rulemaking,
DOE will establish a mathematical
method for determining the rated
efficiency under the new efficiency
descriptor from the rated efficiency
under the existing metrics. Should it
become apparent in the rulemaking to
establish the conversion factor that
changes may be required in the test
procedure, DOE would address any
issues at that time. DOE also plans to
translate its current energy conservation
standards to equivalent standards
denominated in the new uniform
efficiency metric in the separate
rulemaking.
I. Other Issues
DOE also sought comments in the
October 2011 RFI and the January 2013
RFI on any other relevant issues that
commenters believe could affect the test
procedure for water heaters, and
continues to seek comment in today’s
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notice. 76 FR 63211, 63215 (Oct. 12,
2011); 78 FR 2340, 2346 (Jan. 11, 2013).
Although DOE has attempted to identify
those portions of the test procedure
where it believes amendments may be
warranted, interested parties are
welcome to provide comments on any
aspect of the test procedure, including
updates of referenced standards, as part
of this comprehensive 7-year-review
rulemaking.
AET supported keeping the inlet
water temperature at 58 °F. (AET, No. 22
at p. 4) Davis Energy Group provided
data on average inlet water temperatures
reported in studies in California that
ranged from 64.2 °F to 72.3 °F. (Davis
Energy Group, No. 6 at p. 3) Despite
these values being higher than the
current nominal temperature specified
in the current DOE test procedure, DOE
has not seen any data that suggests a
different temperature is more
appropriate on a national basis, so DOE
has tentatively decided to maintain the
inlet temperature at 58 °F in the
proposed test procedure.
AHRI suggested an alternative means
to prepare a storage-type water heater
prior to commencement of the 24-hour
simulated-use test. (AHRI, No. 46 at p.
7) AHRI suggested that DOE could
improve the consistency of energy factor
tests by running the draw patterns on
two consecutive days, with
measurements only taking place during
the second 24-hour period. After careful
consideration, DOE has tentatively
concluded that this approach would
lead to more consistent results since the
state of the water heater at the beginning
of the 24-hour test period will be similar
to that at the end of the test period,
thereby minimizing the need to make
large corrections to the energy
consumption values which could
introduce errors. DOE is aware of testing
conducted in this manner that has
resulted in consistent values for the
energy factor.20 DOE is tentatively
proposing to require storage water
heaters to be pre-conditioned in this
manner. It is DOE’s understanding that
test laboratories must already let the
water heater sit at temperature for an
extended period of time to let the unit
achieve operational temperature.
Therefore, DOE reasons that the
proposed pre-conditioning routine
might be done during this stage, thereby
resulting in little or no added test time.
DOE is interested in comment regarding
the value of the pre-conditioning period
and the incremental burden, if any, that
20 Healy WM,, Lutz JD, and Lekov AB.,
‘‘Variability in Energy Factor Test Results for
Residential Electric Water Heaters,’’ HVAC&R
Research, vol. 9, No. 4 (October 2003).
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it would place on manufacturers. This is
identified as issue 5 in section V.E,
‘‘Issues on Which DOE Seeks
Comment.’’
NREL argued that published metrics
from the DOE test procedure should
allow for calculation of performance
under conditions outside the particular
conditions imposed by the test
procedure. (NREL, No. 29 at p. 1) DOE
does not propose to require any
published metrics from the test
procedure specifically for the purpose of
calculating performance at various
conditions outside of those imposed by
the test method, as the purpose of the
DOE test procedure is to determine
compliance to minimum efficiency
standards and to provide a basis for
representation of energy performance to
consumers.
The joint comment urged DOE to
consider several additional points. (Joint
comment, No. 35 at p. 6) First, it raised
the question as to the appropriate rating
method for a hybrid solar water heating
system whose tank might be passive or
active. DOE notes that solar water
heaters are not covered equipment
under EPCA, and thus the DOE test
method for water heaters need not
address these systems. Further, hybrid
solar water heating systems consisting
of a stand-alone water heater with
additional solar components that are
added in the field could be tested
according to the rating method provided
for the water heater if the solar
components were not present. The
stand-alone heater would be subject to
energy conservation standards without
consideration of the benefits, if any, of
the solar portion. Second, the joint
commenters questioned how to rate
‘‘hybrid’’ fuel-fired units with tanks
larger than 2 gallons. DOE believes that
amendments proposed in this NOPR
will cover those products—the storage
volume gaps that currently exist in the
scope would be removed under this
proposal, and the proposed test method
would cover those products. Lastly, the
joint commenters asked whether test
procedures should reflect energy
savings from ‘‘smart’’ or ‘‘gridinteractive’’ water heaters. DOE does not
believe that a separate test procedure is
warranted for this equipment, because
they are functionally similar to nongrid-interactive water heaters. DOE
acknowledges that usage patterns for
grid-interactive water heaters may be
very different from water heaters that
are not grid-interactive or controlled as
part of demand response programs.
However, DOE believes that there is
generally a wide range of usage patterns
for all water heating products seen in
the field, and it would be impractical to
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attempt to tailor the test method to
every potential usage pattern. Thus,
DOE believes that such differences in
usage patterns are better addressed as
part of standards analyses, rather than
as a separate test method.
PGE commented that a method is
needed for reporting source energy
consumption for future standards
rulemakings, because the commenter
opined that source energy is a more
complete metric for representing the
energy consumed by appliances and
would yield a better comparison
between the energy consumption of gas,
electric, and gas/electric units. The
commenter further opined that the test
procedures should include calculations
to allow for two energy factors, one
based on site energy and one based on
source energy. (PGE, No. 3 at p. 2) In
response to the January 2013 RFI, DOE
received additional comments related to
source-based metrics. EEI stated that,
consistent with other Federal laws, any
new descriptor or conversion factor
should only be based on point-of-use
metrics. (EEI, No. 40 at p. 2) AGA,
NPGA, and APGA all supported a
metric based on the full fuel cycle that
would provide a complete accounting of
energy consumption from extraction,
processing, and transportation of
energy. (AGA, No. 31, at p. 3; NPGA,
No. 32 at p. 1; APGA, No. 39 at p. 1)
In addressing this comment, DOE
notes that the Department has
historically presented national energy
savings (NES) in terms of primary
energy savings (i.e., source energy
savings). However, in response to the
recommendations of a committee on
‘‘Point-of-Use and Full-Fuel-Cycle
Measurement Approaches to Energy
Efficiency Standards’’ appointed by the
National Academy of Science, DOE
announced its intention to use full-fuelcycle (FFC) measures of energy use and
greenhouse gas and other emissions in
the national impact analyses and
emissions analyses included in future
energy conservation standards
rulemakings. 76 FR 51281(August 18,
2011). To this end, DOE has begun to
also estimate energy savings using the
FFC metric. The FFC metric includes
the energy consumed in extracting,
processing, and transporting primary
fuels, and thus presents a more
complete picture of the impacts of
efficiency standards. DOE’s approach is
based on application of FFC multipliers
for each fuel type used by covered
products and equipment, as presented
in DOE’s statement of policy published
in the Federal Register on August 18,
2011. Id.
DOE has reviewed the water heater
test procedures, including today’s
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proposed amendments, in relation to the
newly established FFC policy, and has
tentatively concluded that no
substantive amendments are needed to
the water heater test procedures to
accommodate the FFC policy. In
support of this conclusion, the
following discussion elaborates
separately on the FFC policy
implications for energy efficiency
standards and representations.
For the purposes of energy
conservation standards, the test
procedure-derived measure of energy
consumption and efficiency, including
the regulatory efficiency metric (i.e., EF)
is sufficient and complete enough to
allow for full consideration of the FFC
impacts in the energy conservation
standards analysis. In support of this
conclusion, it is noted that the existing
and future energy conservation
standards for these products are, and are
expected to continue to be, analyzed
independently by fuel type. DOE
believes this independent analytical
approach eliminates any possible
mischaracterization or inappropriate
consideration of a standard’s stringency
that might be associated with the test
procedure’s regulatory metrics for these
products. More specifically, the
commenters’ suggestion to add a sourcebased Energy Factor for water heaters
would not add to or improve the
standards analysis for water heaters
because of the expansion of the
standard’s analysis already incorporated
in the current approach.
For the purposes of representations,
DOE has also tentatively concluded that
some small improvements to the water
heater test procedure are deemed
appropriate to accommodate the FFC
policy. It is important to note that both
the current test procedure and the
proposed revised test method for this
product incorporate numerous measures
of energy consumption and efficiency,
some of which are used in the
regulatory context mentioned above and
some of which support the consumer
information objective of the test
procedure. Although the main thrust of
the PGE, AGA, APGA, and NPGA
suggestions seems to be based on the
assumption that the addition of a
source-based energy factor would
improve analysis for water heater
standards, there also seems to be a
suggestion that such inclusion would
also provide improvement in a nonregulatory or consumer information
context. An important example of a nonregulatory metric is annual energy
consumption, which provides a
complete accounting of the energy
consumption to the consumer and
which can be used to estimate annual
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operating cost. For water heaters, DOE
proposes to add terms in the test
method to quantify daily electric energy
consumption separately from fossil fuel
energy consumption and to add separate
estimates of annual fossil fuel energy
consumption and annual electrical
energy consumption in addition to the
overall annual energy consumption.
This separation would allow the user of
the test procedure to estimate
operational cost of water heaters that
use both fossil fuel and electricity based
on the prices of those different energy
sources. From a consumer’s perspective,
annual operating cost is particularly
useful for the products that have dual
fuel inputs. DOE believes this consumer
cost perspective is reasonably reflected
in the FFC (i.e., the source/site factors
recommended by the commenter are
essentially numerically identical to the
fuel cost ratios published biennially by
the Secretary). Therefore, the
commenters’ suggested addition of a
source-based energy factor using the
suggested multipliers is, in DOE’s view,
not likely to convey any improvement
in product-to-product comparisons
relative to annual operating cost. In fact,
annual operating cost would likely be a
superior basis of comparison for
consumers, considering the familiarity
with annual budgets and the lack of
familiarity with source-based efficiency
comparisons.
In addition, and perhaps more
importantly, annual operating cost
provides a reasonable comparison
across competing product types
utilizing different fuels (e.g., electric
water heaters and gas-fueled water
heaters). Arguably, site-based energy
factors for electric water heaters
(typically approximately 0.9 for an
electric resistance model) would be
higher than the counterpart energy
factors for gas water heaters (typically
approximately 0.6), but not
representative of the relative efficiency
of each type of water heater. Thus, an
inappropriate conclusion would be
conveyed to consumers. DOE believes
such inappropriate conclusions can be
easily avoided in any consumer
information program by focusing on
annual operating cost. Here again, the
biennial published unit cost of energy
would protect the consumer from
inappropriate conclusions. Accordingly,
for purposes of representations, DOE is
not aware, nor has it been made aware
through responses to the request for
information, of any specific problems,
shortcomings, or misrepresentations
resulting from the existing test
procedure measures of energy
consumption and efficiency as it relates
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to the FFC policy. The proposed
amendments to the water heater test
procedure would provide additional
metrics that could be used should one
desire more information related to the
FFC policy for a particular application
of the test method.
DOE is interested in receiving
comment on adding terms to quantify
daily electric energy consumption
separately from fossil fuel energy
consumption and adding separate
estimates of annual fossil fuel energy
consumption and annual electrical
energy consumption in addition to the
overall annual energy consumption.
This is identified as issue 8 in section
V.E, ‘‘Issues on Which DOE Seeks
Comment.’’
A final issue raised by commenters is
that heat pump water heaters that have
recently entered the market typically
have multiple operational modes, and
the current DOE test procedure does not
specify which mode should be used
when the unit is undergoing testing. AO
Smith and AHRI commented that all
heat pump water heaters should be
tested under a single mode of operation
which is the default or ‘‘out-of-the-box’’
condition. (AO Smith, No. 8 at p. 2;
AHRI No. 12 at p. 3) DOE agrees with
this comment and proposes a
clarification to the test procedure to
indicate that heat pump water heaters
are to be tested in the default mode
when obtaining both the first-hour
rating and determining the energy
factor. This clarification is consistent
with guidance issued by DOE on June
12, 2012 (see: https://www1.eere.energy.
gov/guidance/detail_search.aspx?ID
Question=623&pid=2&spid=1).
J. Certification, Compliance, and
Enforcement Issues
In this notice of proposed rulemaking,
DOE proposes to make several changes
to its certification, compliance, and
enforcement regulations at 10 CFR Part
429. First, DOE proposes to add
requirements to 10 CFR 429.17 that the
rated value of storage tank volume must
equal the mean of the measured storage
volume of the units in the sample. DOE
notes that there are currently no
requirements from the Department
limiting the amount of difference that is
allowable between the tested (i.e.,
measured) storage volume and the
‘‘rated’’ storage volume that is specified
by the manufacturer. DOE has tested 65
residential storage-type water heaters,
including 44 gas-fired water heaters, 19
electric water heaters, and 2 oil-fired
water heaters. Through this testing, DOE
has found that water heaters are
consistently rated at storage volumes
above their actual storage volume. For
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gas fired water heaters, the rated volume
ranged from 1.5 to 15.6 percent above
the measured volume, with the mean
being 4.8 percent. For electric water
heaters, the rated volume ranged from
5.0 to 10.6 percent above the measured
volume, with the mean being 9.4
percent. DOE notes that its minimum
energy conservation standards are based
on the rated storage volume and
decrease as rated storage volume
increases. DOE also believes consumers
often look to storage volume as a key
factor in choosing a storage water
heater. Consequently, DOE proposes to
adopt rating requirements that the rated
value must be the mean of the measured
value. In addition, DOE proposes to
specify that for DOE-initiated testing, a
tested value within five percent of the
rated value would be a valid test result
where the rated storage volume would
then be used in downstream
calculations. If the test result of the
volume is invalid (i.e., the measured
value is more than five percent different
than the rated value), then DOE
proposes to use the measured value in
determining the applicable minimum
energy conservation standard and
calculations within the test procedure.
DOE proposes to specify similar
requirements for light commercial water
heaters.
Additionally, because the first-hour
and maximum gpm ratings will
determine the applicable draw pattern
for use during the energy factor test,
DOE proposes to include rating
requirements for those values. DOE
proposes that the rated first-hour rating
or maximum gpm rating, as applicable,
must be the mean of the measured
values of the sample used for certifying
the basic model’s efficiency rating. For
DOE testing, the rating will be
considered valid if it is within five
percent of the certified rating. In such a
case, DOE proposes that the rated value
would be used for the purposes of
choosing the appropriate draw pattern
for the energy factor test. In the case of
an invalid rating (i.e., the rated firsthour rating or maximum gpm rating is
more than five percent different from
the measured value), DOE proposes to
use the measured value to determine the
applicable draw pattern for the energy
factor test.
DOE has further considered section
7.0 of the current test procedure,
‘‘Ratings for Untested Models,’’ and
believes that this information is more
appropriately addressed in the 10 CFR
part 429, which deals with requirements
for certification of residential water
heaters. DOE proposes to remove this
section from Appendix E and place a
similar section in 10 CFR 429.17. DOE
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proposes to maintain the requirements
for gas water heaters, which allow units
using propane gas that have an input
rating within 10 percent of an identical
natural gas unit to use the rating for the
natural gas unit in lieu of separate
testing. However, DOE proposes to
eliminate the provisions for electric
water heaters that currently allow a
manufacturer of electric water heaters
that are identical except with different
input ratings to designate a standard
input rating at which to test the water
heater.
Under the current procedure, the
manufacturer of electric water heaters
may designate the standard input rating
that would apply to all models that are
identical with the exception of the
power input to the heating element and
test only at single input rating. It
provides instructions for specifying the
first-hour rating of units with higher and
lower input ratings than the standard
rating. The procedure also provides that
the energy factor can be assumed to be
the same across all input ratings. DOE
proposes to remove these provisions
due to the proposed revisions in the test
method for the first-hour rating and
energy factor tests. The first-hour rating
would be expected to vary based on the
power input to the electric heating
element, and under the revisions
proposed in this test method the
applicable draw pattern for the energy
factor test would be based on the firsthour rating. As a result, it is important
that the first-hour rating is accurate for
the given model as it will potentially
impact the draw pattern and the
resultant EF rating.
K. Reference Standards
DOE’s test procedure for residential
water heaters currently references two
industry standards: American Society
for Testing and Measurement (ASTM)
D2156–80, ‘‘Smoke Density in Flue
Gases from Burning Distillate Fuels,
Test Method for’’ and ASHRAE
Standard 41.1–1986, ‘‘Standard
Measurement Guide: Section on
Temperature Measurements.’’
DOE proposes to maintain these
references in the uniform efficiency
descriptor test method, but to update
the reference standards to the most
recent versions of the industry
standards: ASTM D2156–09, ‘‘Standard
Test Method for Smoke Density in Flue
Gases from Burning Distillate Fuels’’
and ASHRAE Standard 41.1–1986
(RA2006), ‘‘Standard Method for
Temperature Measurement.’’ DOE has
reviewed both of the updated standards
and has tentatively concluded that their
adoption would not substantially
impact the test method.
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L. Compliance With Other EPCA
Requirements
As mentioned above, in amending a
test procedure, EPCA directs DOE to
determine to what extent, if any, the test
procedure would alter the measured
energy efficiency or measured energy
use of a covered product. (42 U.S.C.
6293(e)(1)) If the amended test
procedure alters the measured energy
efficiency or measured energy use, the
Secretary must amend the applicable
energy conservation standard to the
extent the amended test procedure
changes the energy efficiency of
products that minimally comply with
the existing standard. (42 U.S.C.
6293(e)(2)) The current energy
conservation standards for residential
water heaters are based on energy factor
(EF), and the energy conservation
standards for commercial water heaters
are based on thermal efficiency and
standby loss. DOE believes that the
conversion factor (or factors) required
by AEMTCA (as discussed in section
III.G) will ensure that there is no change
in measured energy efficiency.
Consistent with 42 U.S.C. 6293(c),
DOE typically requires that any
representations of energy consumption
of covered products must be based on
any final amended test procedures 180
days after the publication of the test
procedure final rule. However, in this
instance, the statute specifically
provides for an effective date of the test
procedure final rule which is one year
after the date of the publication of the
final rule. (42 U.S.C. 6295(e)(5)(D)(ii)) In
addition, AEMTCA provides for the use
of a conversion factor that will apply
beginning on the date of publication of
the conversion factor in the Federal
Register and ending on the later of 1
year after the date of publication of the
conversion factor or December 31, 2015.
(42 U.S.C. 6295(e)(5)(E)(v)) Thus, one
year after the publication of the test
procedure final rule, it will become
effective, and manufacturers may at
their discretion make representations of
energy efficiency based either (a) on the
final amended test procedures or (b) on
the previous test procedures after
applying the conversion factor. The
previous test procedures for residential
water heaters are set forth at 10 CFR part
430, subpart B, appendix E as contained
in 10 CFR parts 200 to 499 edition
revised as of January 1, 2013. The
previous test procedures for commercial
water heating equipment are set forth at
10 CFR 431.106 as contained in 10 CFR
parts 200 to 499 edition revised as of
January 1, 2013. As required by
AEMTCA, the conversion factor may be
used until the later of one year after the
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publication of the factor, or December
31, 2015, after which time all testing
must be conducted in accordance with
the new amended test procedure. DOE
notes that during the interim period
manufacturers must use the same test
procedure for representations of energy
efficiency, including certifications of
compliance.
IV. Procedural Issues and Regulatory
Review
A. Review Under Executive Order 12866
The Office of Management and Budget
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 regulatory action was not subject to
review under the Executive Order by the
Office of Information and Regulatory
Affairs (OIRA) in the Office of
Management and Budget (OMB).
B. Review Under the Regulatory
Flexibility Act
The Regulatory Flexibility Act (5
U.S.C. 601 et seq., as amended by the
Small Business Regulatory Enforcement
Fairness Act of 1996) requires
preparation of an initial regulatory
flexibility analysis (IFRA) for any rule
that by law must be proposed for public
comment and a final regulatory
flexibility analysis (FRFA) for any such
rule that an agency adopts as a final
rule, unless the agency certifies that the
rule, if promulgated, will not have a
significant economic impact on a
substantial number of small entities. A
regulatory flexibility analysis examines
the impact of the rule on small entities
and considers alternative ways of
reducing negative effects. Also, 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 at: www.gc.doe.gov/
gc/office-general-counsel.
Today’s proposed rule would
prescribe test procedure amendments
that would be used to determine
compliance with energy conservation
standards for residential water heaters
and certain commercial water heaters.
For residential water heaters and certain
commercial water heaters, the proposed
amendments would establish a uniform
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efficiency descriptor which would be
more representative of conditions
encountered in the field (including
modifications to both the test conditions
and the draw patterns), and expand the
scope of the test procedure to apply to
certain residential water heaters and
certain commercial water heaters that
are currently not covered by the test
procedure. DOE reviewed today’s
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,
30848–49 (May 15, 2000), as amended at
65 FR 53533, 53544–45 (Sept. 5, 2000)
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/idc/groups/public/
documents/sba_homepage/serv_sstd_
tablepdf.pdf. Residential water heater
manufacturing is classified under
NAICS 335228—‘‘Other Major
Household Appliance Manufacturing.’’
The SBA sets a threshold of 500
employees or less for an entity to be
considered as a small business.
Commercial water heaters are classified
under NAICS 333319 –‘‘Other
Commercial and Service Industry
Machinery Manufacturing,’’ for which
SBA also sets a size threshold of 500
employees or fewer for being considered
a small business.
DOE has identified 13 manufacturers
of residential water heaters (including
manufacturers of products that fall
under the proposed expanded scope)
that can be considered small businesses.
DOE identified nine manufacturers of
‘‘light commercial’’ water heaters that
can be considered small businesses.
Seven of the ‘‘light commercial’’ water
heater manufacturers also manufacture
residential water heaters, so the total
number of water heater manufacturers
impacted by this rule would be 15.
DOE’s research involved reviewing
several industry trade association
membership directories (e.g., AHRI),
product databases (e.g., AHRI, CEC, and
ENERGY STAR databases), individual
company Web sites, and marketing
research tools (e.g., Hoovers reports) to
create a list of all domestic small
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business manufacturers of products
covered by this rulemaking.
For the reasons explained below, DOE
has tentatively 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 residential water heaters, the
amendments proposed in today’s notice
of proposed rulemaking apply primarily
to the draw pattern and water delivery
temperature. Under DOE’s existing test
procedure, manufacturers must perform
a simulated use test consisting of 6
draws of equal lengths with a water
heater delivery temperature of 135 °F. If
adopted, today’s proposal would require
manufacturers to perform a simulated
use test consisting of 9 to 14 draws of
varied length, depending on the
capacity of the water heater, at a water
delivery temperature of 125 °F. The
change in water delivery temperature
requires no additional effort or expense
for the manufacturer, because
establishing the test temperature is
simply a matter of choosing the
appropriate setting on the water heater.
Likewise, the change in the number of
draws would also result in very little
burden on manufacturers. The length
and timing of draws for the existing test
procedure are largely controlled
automatically by computer control. The
proposed changes would result in
manufacturers having to reprogram the
computer test programs to account for
the new draw patterns. DOE estimates
that this effort would take
approximately one week to program and
confirm operation of the amended test.
It is estimated that approximately two
days of a programmer’s time would be
needed at a cost of $1,000 including
overhead and benefits. This one-time
cost is comparable to that charged by a
third-party test laboratory for a single
test, so it is not considered burdensome
for water heater manufacturers. Since
the simulated use test takes 24 hours
under both the existing and proposed
test method, the length of the test would
not change. The current proposal does
specify a 24-hour pre-conditioning
period prior to the 24-hour test for
storage water heaters, however, which
would add to the time required to
conduct the test. This extra test time
would not require extra personnel, but
it may necessitate the development of
additional test platforms to
accommodate the amount of testing that
a manufacturer must conduct. A
duplicate test platform, if necessary,
could result in an additional cost of
approximately $5,000 in terms of
materials and time needed for
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construction. DOE understands,
however, that a 24-hour preconditioning period is already
implemented by manufacturers as a best
practice to allow the water heater to
achieve operational temperature, so the
added burden would be minimal. In
addition, these tests can be conducted
in the same facilities used for the
current energy testing of these products,
so there would be no additional facility
costs required by the proposed rule.
Lastly, the only potential
instrumentation upgrade required to
conduct the test would be electric
power and energy measuring equipment
that meets the accuracy levels that have
changed from ± 1 percent to ± 0.5
percent. DOE believes that equipment
meeting these tolerances is already the
industry standard. Purchase of a new
instrument, if needed, would be
expected to cost approximately $1,000.
For certain commercial water heaters
included in the scope of this
rulemaking, the efficiency test required
for equipment would change from the
thermal efficiency and standby loss tests
specified in the current DOE test
method, to the simulated use test for
energy factor proposed in today’s NOPR.
The energy factor test is inherently more
complex than the thermal efficiency and
standby loss tests, and, thus, it may be
more difficult to implement. However,
the standby loss test takes a significant
amount of time, which is comparable to
the 24-hour simulated use test.
Accordingly, overall testing time should
remain fairly constant. DOE
understands that the complexity of the
energy factor test would impose
additional costs on manufacturers due
to the need to automate draw patterns,
as compared to the thermal efficiency
test. In addition, some hardware
purchases may be needed to allow for
computer-controlled draws of hot water
that are required in a simulated use test.
However, DOE notes that many
commercial water heater manufacturers
also manufacture residential water
heaters, and may already have this
equipment from testing of residential
units. Nonetheless, DOE estimates that
this hardware could cost approximately
$1,000, assuming that the laboratory
already has a computer-controlled data
acquisition system to collect data during
the thermal efficiency and standby loss
tests currently required. DOE estimates
the costs for a programmer to create a
computer program that automatically
controls the hot water draws would be
similar to the costs above, but that the
time required may be slightly longer if
the program is being developed from
scratch. Under such circumstances, DOE
estimates that 5 days of programmer
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time would be needed for a cost of
$2,500, including overhead and
benefits.
Lastly, DOE considered the impacts
on small businesses that manufacture
residential water heaters that fall into
categories that were previously not
covered by the DOE residential water
heater test procedure (e.g., models with
storage volumes between 2 and 20
gallons). In reviewing the market for
these products, DOE did not identify
any manufacturers that did not also
manufacture other types of water
heating equipment. Thus, DOE believes
that these manufacturers would already
have the needed equipment and
computer programs to conduct the
current DOE test. For the reasons stated
previously, DOE does not believe the
proposed updates will cause significant
additional burdens for these
manufacturers.
Accordingly, DOE tentatively
concludes and certifies that this
proposed rule would not have a
significant economic impact on a
substantial number of small entities, so
DOE has not prepared a regulatory
flexibility analysis for this rulemaking.
DOE will provide its certification and
supporting statement of factual basis to
the Chief Counsel for Advocacy of the
SBA for review under 5 U.S.C. 605(b).
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C. Review Under the Paperwork
Reduction Act of 1995
Manufacturers of water heaters must
certify to DOE that their products
comply with all applicable energy
conservation standards. In certifying
compliance, manufacturers must test
their products according to the DOE test
procedure for water heaters, including
any amendments adopted for the test
procedure on the date that compliance
is required. DOE has established
regulations for the certification and
recordkeeping requirements for all
covered consumer products and
commercial equipment, including
residential and commercial water
heaters. (76 FR 12422 (March 7, 2011).
The collection-of-information
requirement for certification and
recordkeeping is subject to review and
approval by OMB under the Paperwork
Reduction Act (PRA). This requirement
has been approved by OMB under OMB
control number 1910–1400. Public
reporting burden for the certification is
estimated to average 20 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.
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Notwithstanding any other provision
of the law, no person is required to
respond to, nor shall any person be
subject to a penalty for failure to comply
with, a collection of information subject
to the requirements of the PRA, unless
that collection of information displays a
currently valid OMB Control Number.
D. Review Under the National
Environmental Policy Act of 1969
In this proposed rule, DOE proposes
test procedure amendments that it
expects will be used to develop and
implement future energy conservation
standards for residential and
commercial water heaters. 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 test
procedures 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 Federal
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
tentatively determined that it would not
have a substantial direct effect on the
States, on the relationship between the
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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
today’s 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 tentatively 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
regulatory actions likely to result in a
rule that may cause the expenditure by
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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
‘‘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 www.gc.doe.gov/gc/
office-general-counsel.) DOE examined
today’s proposed rule according to
UMRA and its statement of policy and
has tentatively 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.
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
H. Review Under the Treasury and
General Government Appropriations
Act, 1999
Section 654 of the Treasury and
General Government Appropriations
Act, 1999 (Pub. L. 105–277) requires
Federal agencies to issue a Family
Policymaking Assessment for any rule
that may affect family well-being. This
rule would not have any impact on the
autonomy or integrity of the family as
an institution. Accordingly, DOE has
concluded that it is not necessary to
prepare a Family Policymaking
Assessment.
I. Review Under Executive Order 12630
Pursuant to Executive Order 12630,
‘‘Governmental Actions and Interference
with Constitutionally Protected Property
Rights,’’ 53 FR 8859 (March 18, 1988),
DOE has determined that this proposed
rule 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
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Act, 2001 (44 U.S.C. 3516 note) provides
for Federal agencies to review most
disseminations of information to the
public under information quality
guidelines established by each agency
pursuant to general guidelines issued by
OMB. OMB’s guidelines were published
at 67 FR 8452 (Feb. 22, 2002), and
DOE’s guidelines were published at 67
FR 62446 (Oct. 7, 2002). DOE has
reviewed today’s 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
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.
Today’s regulatory action to amend
the test procedures for measuring the
energy efficiency of residential water
heaters and certain commercial water
heaters 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
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Energy Administration Act of 1974
(Pub. L. 93–275), as amended by the
Federal Energy Administration
Authorization Act of 1977 (Pub. L. 95–
70). (15 U.S.C. 788; FEAA) Section 32
essentially provides in relevant part
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.
Today’s proposed rule would
incorporate testing methods contained
in the following commercial standards:
(1) ASTM D2156–09, ‘‘Standard Test
Method for Smoke Density in Flue
Gases from Burning Distillate Fuels’’;
and (2) ASHRAE Standard 41.1–1986
(RA 2006), ‘‘Standard Method for
Temperature Measurement.’’ While
today’s proposed test procedure is not
exclusively based on these standards,
components of the test procedures are
adopted directly from these standards
without amendment. The Department
has evaluated these standards and is
unable to conclude whether they fully
comply with the requirements of section
32(b) of the FEAA, (i.e., that they were
developed in a manner that fully
provides for public participation,
comment, and review). DOE will
consult with the Attorney General and
the Chairman of the FTC concerning the
impact on competition of requiring
manufacturers to use the test methods
contained in these standards prior to
prescribing a final rule.
V. Public Participation
A. Attendance at the Public Meeting
The time, date and location of the
public meeting are listed in the DATES
and ADDRESSES sections at the beginning
of this document. If you plan to attend
the public meeting, please notify Ms.
Brenda Edwards at (202) 586–2945 or
Brenda.Edwards@ee.doe.gov. As
explained in the ADDRESSES section,
foreign nationals visiting DOE
Headquarters are subject to advance
security screening procedures. Any
foreign national wishing to participate
in the meeting should advise DOE of
this fact as soon as possible by
contacting Ms. Brenda Edwards to
initiate the necessary procedures.
In addition, you can attend the public
meeting via webinar. Webinar
registration information, participant
instructions, and information about the
capabilities available to webinar
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EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
participants will be published on DOE’s
Web site at: https://
www1.eere.energy.gov/buildings/
appliance_ standards/
rulemaking.aspx?ruleid=82. Participants
are responsible for ensuring their
systems are compatible with the
webinar software.
B. Procedure for Submitting Requests To
Speak and Prepared General Statements
for Distribution
Any person who has an interest in the
topics addressed in this notice, or who
is representative of a group or class of
persons that has an interest in these
issues, may request an opportunity to
make an oral presentation at the public
meeting. Such persons may handdeliver requests to speak to the address
shown in the ADDRESSES section at the
beginning of this notice of proposed
rulemakiing between 9:00 a.m. and 4:00
p.m., Monday through Friday, except
Federal holidays. Requests may also be
sent by mail or email to Ms. Brenda
Edwards, U.S. Department of Energy,
Building Technologies Office, Mailstop
EE–2J, 1000 Independence Avenue SW.,
Washington, DC 20585–0121, or
Brenda.Edwards@ee.doe.gov. Persons
who wish to speak should include in
their request a computer diskette or CD–
ROM in WordPerfect, Microsoft Word,
PDF, or text (ASCII) file format that
briefly describes the nature of their
interest in this rulemaking and the
topics they wish to discuss. Such
persons should also provide a daytime
telephone number where they can be
reached.
DOE requests persons selected to
make an oral presentation to submit an
advance copy of their statements at least
one week before the public meeting.
DOE may permit persons who cannot
supply an advance copy of their
statement to participate, if those persons
have made advance alternative
arrangements with the Building
Technologies Office. As necessary,
requests to give an oral presentation
should ask for such alternative
arrangements.
Any person who has plans to present
a prepared general statement may
request that copies of his or her
statement be made available at the
public meeting. Such persons may
submit requests, along with an advance
electronic copy of their statement in
PDF (preferred), Microsoft Word or
Excel, WordPerfect, or text (ASCII) file
format, to the appropriate address
shown in the ADDRESSES section at the
beginning of this notice of proposed
rulemaking. The request and advance
copy of statements must be received at
least one week before the public
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meeting and may be emailed, handdelivered, or sent by mail. DOE prefers
to receive requests and advance copies
via email. Please include a telephone
number to enable DOE staff to make
follow-up contact, if needed.
C. Conduct of the Public Meeting
DOE will designate a DOE official to
preside at the public meeting and may
also use a professional facilitator to aid
discussion. The meeting will not be a
judicial or evidentiary-type public
hearing, but DOE will conduct it in
accordance with section 336 of EPCA
(42 U.S.C. 6306). A court reporter will
be present to record the proceedings and
prepare a transcript. DOE reserves the
right to schedule the order of
presentations and to establish the
procedures governing the conduct of the
public meeting. There shall not be
discussion of proprietary information,
costs or prices, market share, or other
commercial matters regulated by U.S.
anti-trust laws. After the public meeting,
interested parties may submit further
comments on the proceedings, as well
as on any aspect of the rulemaking, until
the end of the comment period.
The public meeting will be conducted
in an informal, conference style. DOE
will present summaries of comments
received before the public meeting,
allow time for prepared general
statements by participants, and
encourage all interested parties to share
their views on issues affecting this
rulemaking. Each participant will be
allowed to make a general statement
(within time limits determined by DOE),
before the discussion of specific topics.
DOE will allow, as time permits, other
participants to comment briefly on any
general statements.
At the end of all prepared statements
on a topic, DOE will permit participants
to clarify their statements briefly and
comment on statements made by others.
Participants should be prepared to
answer questions by DOE and by other
participants concerning these issues.
DOE representatives may also ask
questions of participants concerning
other matters relevant to this
rulemaking. The official conducting the
public meeting will accept additional
comments or questions from those
attending, as time permits. The
presiding official will announce any
further procedural rules or modification
of the above procedures that may be
needed for the proper conduct of the
public meeting.
A transcript of the public meeting will
be included in the docket, which can be
viewed as described in the Docket
section at the beginning of this notice of
the proposed rulemaking, and will be
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accessible on the DOE Web site. In
addition, any person may buy a copy of
the transcript from the transcribing
reporter.
D. Submission of Comments
DOE will accept comments, data, and
information regarding this proposed
rule before or after the public meeting,
but no later than the date provided in
the DATES section at the beginning of
this proposed rule. Interested parties
may submit comments using any of the
methods described in the ADDRESSES
section at the beginning of this notice of
proposed rulemaking.
Submitting comments via
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
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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, written in English, and are free
of any defects or viruses. Documents
should not contain special characters or
any form of encryption and, if possible,
they should carry the electronic
signature of the author.
Campaign form letters. Please submit
campaign form letters by the originating
organization in batches of between 50 to
500 form letters per PDF or as one form
letter with a list of supporters’ names
compiled into one or more PDFs. This
reduces comment processing and
posting time.
Confidential Business Information.
Pursuant to 10 CFR 1004.11, any person
submitting information that he or she
believes to be confidential and exempt
by law from public disclosure should
submit via email, postal mail, or hand
delivery/courier two well-marked
copies: One copy of the document
marked ‘‘confidential’’ including all the
information believed to be confidential,
and one copy of the document marked
‘‘non-confidential’’ with the information
believed to be confidential deleted.
Submit these documents via email or on
a CD, if feasible. DOE will make its own
determination about the confidential
status of the information and treat it
according to its determination.
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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).
E. 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 the proposed definition of ‘‘light
commercial water heater’’ appropriate,
and is it appropriate to test commercial
water heaters meeting this definition
under the uniform descriptor, while
testing all other commercial water
heaters using thermal efficiency and
standby loss?
2. Is information or data available
regarding the translation of current firsthour ratings to a first-hour rating
determined using the proposed 125 °F
set point? What is the effect of such
translation on the appropriate
breakpoints between different size
categories?
3. Is the proposed method of
characterizing water heaters as point-ofuse, low, medium, or high appropriate
and sufficient?
4. Are the draw patterns proposed for
the different water heater size categories
appropriate?
5. What is the added burden, if any,
in requiring a 24-hour pre-conditioning
period for storage-type water heaters
compared to current practice?
6. Is the proposed change to the
nominal water delivery temperature to
125 °F appropriate, and if not, what data
or information is available that would
justify a different water delivery
temperature?
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7. Is the proposed method for setting
the thermostat(s) of storage-type water
heaters appropriate?
8. The addition of terms to quantify
daily electric energy consumption
separately from fossil fuel energy
consumption and adding separate
estimates of annual fossil fuel energy
consumption and annual electrical
energy consumption in addition to the
overall annual energy consumption.
VI. Approval of the Office of the
Secretary
The Secretary of Energy has approved
publication of today’s 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 October 28,
2013.
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.
2. Section 429.17 is amended by
adding new paragraphs (a)(2)(iii),
(a)(2)(iv), (c), and (d) to read as follows:
■
§ 429.17
Residential water heaters.
(a) * * *
(2) * * *
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(iii) Any represented value of the
rated storage volume must be calculated
as the mean of the measured storage
volumes, Vst, of all the units within the
sample.
(iv) Any represented value of firsthour rating for storage water heaters or
maximum gallons per minute (gpm for
instantaneous water heaters must be
calculated as the mean of the measured
first-hour ratings or measured max gpm
ratings, respectively, of all the units
within the sample.
*
*
*
*
*
(c) Determination of ratings for
untested basic models. Manufacturers of
gas-fired water heaters are not required
to test other models that differ from
tested basic models only in whether the
unit uses natural gas or propane gas. In
lieu of testing, the represented value for
a model that utilizes propane gas must
be identical to the basic model that
utilizes natural gas as long as the rated
input ratings are within ±10% for both
basic models.
(d) Represented values. The
requirements of § 429.17 are applicable
to all values reported in accordance
with paragraphs (b) and (c) of this
section. Represented values of energy
factor shall be rounded off to the nearest
0.01.
■ 3. Section 429.44 is amended by:
■ a. Redesignating paragraphs (a), (b)
and (c) as (b), (c) and (d);
■ b. Adding a new paragraph (a); and
■ c. Revising newly redesignated
paragraph (b).
The revisions and additions read as
follows:
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
§ 429.44 Commercial water heating
equipment.
(a) For light commercial water
heaters, all represented values should be
determined in accordance with § 429.17.
(b) Determination of Represented
Value for All Types of Commercial
Water Heaters except Light Commercial
Water Heaters. Manufacturers can
determine the represented value, which
includes the certified rating, for each
basic model of commercial water
heating equipment except light
commercial water heaters, either by
testing, in conjunction with the
applicable sampling provisions, or by
applying a validated AEDM.
*
*
*
*
*
■ 4. Add § 429.134 to read as follows:
§ 429.134 Product-specific enforcement
provisions.
(a) [Reserved].
(b) [Reserved].
(c) [Reserved].
(d) Residential Water Heaters and
Light Commercial Water Heaters. (1)
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Verification of rated first-hour rating
and rated maximum gpm rating. The
first-hour rating (for storage water
heaters) or maximum gallons per minute
(gpm) rating (for instantaneous water
heaters) of the basic model will be
measured pursuant to the test
requirements of part 430 for each unit
tested. The results of the
measurement(s) will be averaged and
compared to the value of first-hour
rating (for storage water heaters) or
maximum gpm rating (for instantaneous
water heaters) certified by the
manufacturer. The certified rating will
be considered valid only if the
measurement is within five percent of
the certified rating.
(i) If the certified first-hour rating or
maximum gpm rating is found to be
valid, that rating will be used as the
basis for determining the applicable
draw pattern pursuant to the test
requirements of part 430 for each unit
tested.
(ii) If the certified first-hour rating or
maximum gpm rating is found to be
invalid, the average measured rating
will serve as the basis for determining
the applicable draw pattern pursuant to
the test requirements of part 430 for
each unit tested.
(2) Verification of rated storage
volume. The storage volume of the basic
model will be measured pursuant to the
test requirements of part 430 for each
unit tested. The results of the
measurement(s) will be averaged and
compared to the rated storage volume
certified by the manufacturer. The
certified rating will be considered valid
only if the measurement is within five
percent of the certified rating.
(i) If the certified rated storage volume
is found to be valid, that volume will be
used as the basis for calculation of the
required energy factor for the basic
model.
(ii) If the certified rated storage
volume is found to be invalid, the
average measured volume will be used
as the basis for calculation of the
required energy factor for the basic
model.
PART 430—ENERGY CONSERVATION
PROGRAM FOR CONSUMER
PRODUCTS
5. The authority citation for part 430
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6309; 28 U.S.C.
2461 note.
6. Section 430.2 is amended by adding
the definitions of ‘‘Electric
instantaneous water heater,’’ ‘‘Electric
storage water heater,’’ ‘‘Gas-fired
instantaneous water heater,’’ ‘‘Gas-fired
storage water heater,’’ ‘‘Heat pump
■
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water heater,’’ and ‘‘Oil storage water
heater’’ in alphabetical order, to read as
follows:
§ 430.2
Definitions.
*
*
*
*
*
Electric instantaneous water heater
means a water heater that uses
electricity as the energy source, initiates
heating based on sensing water flow, is
not capable of delivering water at a
controlled temperature of 180 °F (82 °C)
or greater, has a maximum nameplate
input rating 12 kW (40,956 Btu/h) or
less, and has a rated storage capacity of
less than 2 gallons (7.6 liters). The unit
may use a fixed or variable burner
input.
*
*
*
*
*
Electric storage water heater means a
water heater that uses electricity as the
energy source, is not capable of heating
and storing water at a thermostatically
controlled temperature of 180 °F (82 °C)
or greater, has a maximum nameplate
input rating of 12 kW (40,956 Btu/h) or
less, and has a rated storage capacity of
not less than 2 gallons (7.6 liters) nor
more than 120 gallons (450 liters).
*
*
*
*
*
Gas-fired instantaneous water heater
means a water heater that uses gas as the
main energy source, initiates heating
based on sensing water flow, is not
capable of delivering water at a
controlled temperature of 180 °F (82 °C)
or greater, has a maximum nameplate
input rating less than 200,000 Btu/h
(210 MJ/h), and has a rated storage
capacity of less than 2 gallons (7.6
liters). The unit may use a fixed or
variable burner input.
Gas-fired storage water heater means
a water heater that uses gas as the main
energy source, is not capable of heating
and storing water at a thermostatically
controlled temperature of 180 °F (82 °C)
or greater, has a maximum nameplate
input rating of 75,000 Btu/h (79 MJ/h)
or less, and has a rated storage capacity
of not less than 2 gallons (7.6 liters) nor
more than 120 gallons (380 liters).
*
*
*
*
*
Heat pump water heater means a
water heater that uses electricity as the
energy source, is not capable of heating
and storing water at a thermostaticallycontrolled temperature of 180 °F (82 °C)
or greater, has a maximum current
rating of 24 amperes (including the
compressor and all auxiliary equipment
such as fans, pumps, controls, and, if on
the same circuit, any resistive elements)
for an input voltage of 250 volts or less,
and, has a rated storage capacity of 120
gallons (450 liters) or less.
*
*
*
*
*
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Oil storage water heater means a
water heater that uses oil as the energy
source, is not capable of heating and
storing water at a thermostatically
controlled temperature of 180 °F (82 °C)
or greater, has a nameplate input rating
of 105,000 Btu/h (110 MJ/h) or less, and
has a manufacturer’s rated storage
capacity of 120 gallons (190 liters) or
less.
*
*
*
*
*
■ 7. Section 430.3 is amended by:
■ a. Adding paragraph (f)(11);
■ b. Redesignating paragraphs (h)
through (p) as (i) through (o),
respectively; and
■ c. Adding a new paragraph (h).
The additions read as follows:
§ 430.3 Materials incorporated by
reference.
*
*
*
*
*
(f) * * *
(11) ASHRAE 41.1–1986 (RA 2006),
Standard Method for Temperature
Measurement, ASHRAE approved June
27, 2007, ANSI approved March 25,
2008, IBR approved for appendix E to
subpart B of this part.
*
*
*
*
*
(h) ASTM. American Society for
Testing and Materials International, 100
Barr Harbor Drive, P.O. Box C700, West
Conshohocken, PA 19428–2959
(www.astm.org).
(1) ASTM D2156–09 (‘‘ASTM
D2156’’), Standard Test Method for
Smoke Density in Flue Gases from
Burning Distillate Fuels, Edition 09,
ASTM approved December 1, 2009, IBR
approved for appendix E to subpart B of
this part.
(2) [Reserved]
*
*
*
*
*
■ 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.
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*
*
*
*
*
(e) Water Heaters. (1) The estimated
annual operating cost for water heaters
shall be—
(i) For a gas or oil water heater, the
sum of (a) the product of the annual gas
or oil energy consumption, determined
according to section 6.1.10 or 6.2.7 of
appendix E of this subpart, times the
representative average unit cost of gas or
oil, as appropriate, in dollars per Btu as
provided by the Secretary; plus (b) the
product of the annual electric energy
consumption, determined according to
section 6.1.9 or 6.2.6 of appendix E of
this subpart, times the representative
average unit cost of electricity in dollars
per kilowatt-hour as provided by the
Secretary, the resulting sum then being
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rounded off to the nearest dollar per
year.
(ii) For an electric water heater, the
product of the annual energy
consumption, determined according to
section 6.1.9 or 6.2.6 of appendix E of
this subpart, times the representative
average unit cost of electricity in dollars
per kilowatt-hour as provided by the
Secretary, the resulting product then
being rounded off to the nearest dollar
per year.
(2) For an individual test, the tested
energy factor for a water heater shall
be—
(i) For a gas or oil water heater, as
determined by section 6.1.7 or 6.2.4 of
appendix E of this subpart rounded to
the nearest 0.01.
(ii) For an electric water heater, as
determined by section 6.1.7 or 6.2.4 of
appendix E of this subpart rounded to
the nearest 0.01.
*
*
*
*
*
■ 9. Appendix E to Subpart B of Part
430 is revised to read as follows:
Appendix E to Subpart B of Part 430—
Uniform Test Method for Measuring the
Energy Consumption of Water Heaters
Note: After [date 365 days after publication
of a final rule in the Federal Register that
establishes a conversion factor, or December
31, 2015, whichever is later], any
representations made with respect to the
energy use or efficiency of residential water
heaters and commercial water heaters
covered by this test method must be made in
accordance with the results of testing
pursuant to this appendix.
Manufacturers conducting tests of
residential water heaters and commercial
water heaters covered by this test method
after [date 365 days after publication of the
test procedure final rule in the Federal
Register] and prior to [date 365 days after
publication of the final rule in the Federal
Register that establishes a conversion factor,
or December 31, 2015, whichever is later]
must conduct such test in accordance with
either this appendix or previous test method.
For residential water heaters the previous test
method is appendix E as it appeared at 10
CFR part 430, subpart B, appendix E, in the
10 CFR parts 200 to 499 edition revised as
of January 1, 2013. For commercial water
heaters the previous test method is 10 CFR
431.106 in the 10 CFR parts 200 to 499
edition revised as of January 1, 2013. Any
representations made with respect to the
energy use or efficiency of such water heaters
must be in accordance with whichever
version is selected.
1. Definitions
1.1. Cut-in means the time when or water
temperature at which a water heater control
or thermostat acts to increase the energy or
fuel input to the heating elements,
compressor, or burner.
1.2. Cut-out means the time when or water
temperature at which a water heater control
or thermostat acts to reduce to a minimum
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the energy or fuel input to the heating
elements, compressor, or burner.
1.3. Design Power Rating means the
nominal power rating that a water heater
manufacturer assigns to a particular design of
water heater, expressed in kilowatts or Btu
(kJ) per hour as appropriate.
1.4. Draw Cluster means a collection of
water draw events during the simulated-use
test that are closely grouped in time.
1.5. Energy Factor means the measure of
water heater overall efficiency.
1.6. First-Hour Rating means the estimate
of the maximum volume of ‘‘hot’’ water that
a storage-type water heater can supply within
an hour that begins with the water heater
fully heated (i.e., with all thermostats
satisfied). It is a function of both the storage
volume and the recovery rate.
1.7. Heat Trap means a device which can
be integrally connected or independently
attached to the hot and/ or cold water pipe
connections of a water heater such that the
device will develop a thermal or mechanical
seal to minimize the recirculation of water
due to thermal convection between the water
heater tank and its connecting pipes.
1.8. Maximum gpm (L/ min) Rating means
the maximum gallons per minute (liters per
minute) of hot water that can be supplied by
an instantaneous water heater while
maintaining a nominal temperature rise of 67
°F (37.3 °C) during steady-state operation, as
determined by testing in accordance with
section 5.3.2 of this appendix.
1.9. Rated Storage Volume means the water
storage capacity of a water heater, in gallons
(liters), as certified by the manufacturer
pursuant to 10 CFR part 429.
1.10. Recovery Efficiency means the ratio of
energy delivered to the water to the energy
content of the fuel consumed by the water
heater.
1.11. Recovery Period means the time when
the main burner of a storage water heater is
raising the temperature of the stored water.
1.12. Standby means the time, in hours,
during which water is not being withdrawn
from the water heater. There are two standby
time intervals used within this test
procedure: tstby,1 represents the elapsed time
between the time at which the maximum
mean tank temperature is observed after the
first draw cluster and the minute prior to the
start of the first draw following the end of the
first draw cluster of the 24-hour simulated
use test; tstby,2 represents the total time
during the 24-hour simulated use test when
water is not being withdrawn from the water
heater.
1.13. Symbol Usage. The following identity
relationships are provided to help clarify the
symbology used throughout this procedure:
Cp specific heat of water
Eannual annual energy consumption of a
water heater
Eannual,e annual electrical energy
consumption of a water heater
Eannual,f annual fossil-fuel energy
consumption of a water heater
Ef energy factor of a water heater
Fhr first-hour rating of a storage-type water
heater
Fmax maximum gpm (L/ min) rating of an
instantaneous water heater rated at a
temperature rise of 67 °F (37.3 °C)
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i a subscript to indicate the draw number
during a test
Mi mass of water removed during the ith
draw of the 24-hr simulated use test
M*i for storage-type water heaters, mass of
water removed during the ith draw during
the first-hour rating test
M10m for instantaneous water heaters, mass
of water removed continuously during a
10-minute interval in the maximum gpm
(L/min) rating test
n for storage-type water heaters, total
number of draws during the first-hour
rating test
N total number of draws during the 24-hr
simulated use test
Q total fossil fuel and/or electric energy
consumed during the entire 24-hr
simulated use test
Qd daily water heating energy consumption
adjusted for net change in internal energy
Qda Qd with adjustment for variation of tank
to ambient air temperature difference from
nominal value
Qdm overall adjusted daily water heating
energy consumption including Qda and
QHWD
Qe total electrical energy used during the
24-hour simulated use test
Qf total fossil fuel energy used by the water
heater during the 24-hour simulated use
test
Qhr hourly standby losses
QHW daily energy consumption to heat
water at the measured average temperature
rise across the water heater
QHW,67 °F daily energy consumption to heat
quantity of water removed during test over
a temperature rise of 67 °F (37.3 °C)
QHWD adjustment to daily energy
consumption, QHW, due to variation of the
temperature rise across the water heater
not equal to the nominal value of 67 °F
Qr energy consumption of water heater
from the beginning of the test to the end
of the first recovery period following the
first draw, which may extend beyond
subsequent draws
Qstby total energy consumed by the water
heater during the standby time interval
tstby,1
Qsu,0 total fossil fuel and/or electric energy
consumed from the beginning of the test to
the end of the cutout following the first
draw cluster
Qsu,f total fossil fuel and/or electric energy
consumed from the beginning of the test to
the initiation of the first draw following the
first draw cluster
T0 mean tank temperature at the beginning
of the 24-hr simulated use test
T24 mean tank temperature at the end of the
24-hr simulated use test
Ta,stby average ambient air temperature
during standby periods of the 24-hr
simulated use test
Tdel for instantaneous water heaters, average
outlet water temperature during a 10minute continuous draw interval in the
maximum gpm (L/ min) rating test
Tdel,i average outlet water temperature
during the ith draw of the 24-hr simulated
use test
Tin for instantaneous water heaters, average
inlet water temperature during a 10-minute
continuous draw interval in the maximum
gpm (L/ min) rating test
Tin,i average inlet water temperature during
the ith draw of the 24-hr simulated use test
Tmax,1 maximum measured mean tank
temperature after cut-out following the first
draw of the 24-hr simulated use test
Tstby average storage tank temperature
during the standby period tstby,2 of the 24hr simulated use test
Tsu,0 maximum measured mean tank
temperature at the beginning of the standby
period which occurs after cut-out following
the final draw of the first draw cluster
Tsu,f measured mean tank temperature at the
end of the standby period which occurs at
the minute prior to commencement of the
first draw that follows the end of the first
draw cluster
Tt,stby average storage tank temperature
during the standby period tstby,1 of the 24hr simulated use test
T*del,i for storage-type water heaters, average
outlet water temperature during the ith
draw (i=1 to n) of the first-hour rating test
T*max,i for storage-type water heaters,
maximum outlet water temperature
observed during the ith draw (i=1 to n) of
the first-hour rating test
T*min,i for storage-type water heaters,
minimum outlet water temperature to
terminate the ith draw (i=1 to n) of the
first-hour rating test
UA standby loss coefficient of a storagetype water heater
Vi volume of water removed during the ith
draw (i=1 to N) of the 24-hr simulated use
test
V*i volume of water removed during the ith
draw (i=1 to n) of the first-hour rating test
V10m for instantaneous water heaters,
volume of water removed continuously
during a 10-minute interval in the
maximum gpm (L/ min) rating test
Vst measured storage volume of the storage
tank
Wf weight of storage tank when completely
filled with water
Wt tare weight of storage tank when
completely empty of water
hr recovery efficiency
r density of water
tstby,1 elapsed time between the time the
maximum mean tank temperature is
observed after the first draw cluster and the
minute prior to the start of the first draw
following the first draw cluster
tstby,2 overall time of standby periods when
no water is withdrawn during the 24-hr
simulated use test
2. Test Conditions
2.1 Installation Requirements. Tests shall
be performed with the water heater and
Item measured
±0.1 inch of water column (±0.025 kPa) .........
±0.1 inch of mercury column (±0.34 kPa) .......
3. Instrumentation
3.1 Pressure Measurements. Pressuremeasuring instruments shall have an error no
greater than the following values:
Instrument accuracy
Gas pressure ......................................................
Atmospheric pressure ........................................
instrumentation installed in accordance with
Section 4 of this appendix.
2.2 Ambient Air Temperature. The
ambient air temperature shall be maintained
between 65.0 °F and 70.0 °F (18.3 °C and 21.1
°C) on a continuous basis. For heat pump
water heaters, the dry bulb temperature shall
be maintained at 67.5 °F ± 1 °F (19.7 °C ±
0.6 °C) and, in addition, the relative humidity
shall be maintained between 48% and 52%
throughout the test.
2.3 Supply Water Temperature. The
temperature of the water being supplied to
the water heater shall be maintained at 58 °F
± 2 °F (14.4 °C ± 1.1 °C) throughout the test.
2.4 Storage Tank Temperature. The
thermostats of a storage-type water heater
shall be set so that water is delivered at a
temperature of 125 °F ± 5 °F (51.7°C ± 2.8 °C).
2.5 Set Point Temperature. The
thermostat of instantaneous water heaters
shall be set to deliver water at a temperature
of 125 °F ± 5 °F (51.7 °C ± 2.8 °C).
2.6 Supply Water Pressure. During the
test when water is not being withdrawn, the
supply pressure shall be maintained between
40 psig (275 kPa) and the maximum
allowable pressure specified by the water
heater manufacturer.
2.7 Electrical and/ or Fossil Fuel Supply.
2.7.1 Electrical. Maintain the electrical
supply voltage to within ±1% of the center
of the voltage range specified by the water
heater and/or heat pump manufacturer.
2.7.2 Natural Gas. Maintain the supply
pressure in accordance with the
manufacturer’s specifications. If the supply
pressure is not specified, maintain a supply
pressure of 7–10 inches of water column
(1.7–2.5 kPa). If the water heater is equipped
with a gas appliance pressure regulator, the
regulator outlet pressure shall be within ±
10% of the manufacturer’s specified
manifold pressure. For all tests, use natural
gas having a heating value of approximately
1,025 Btu per standard cubic foot (38,190 kJ
per standard cubic meter).
2.7.3 Propane Gas. Maintain the supply
pressure in accordance with the
manufacturer’s specifications. If the supply
pressure is not specified, maintain a supply
pressure of 11–13 inches of water column
(2.7–3.2 kPa). If the water heater is equipped
with a gas appliance pressure regulator, the
regulator outlet pressure shall be within ±
10% of the manufacturer’s specified
manifold pressure. For all tests, use propane
gas with a heating value of approximately
2,500 Btu per standard cubic foot (93,147 kJ
per standard cubic meter).
2.7.4 Fuel Oil Supply. Maintain an
uninterrupted supply of fuel oil. Use fuel oil
having a heating value of approximately
138,700 Btu per gallon (38,660 kJ per liter).
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17:46 Nov 01, 2013
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Instrument precision
±0.05 inch of water column (±0.012 kPa).
±0.05 inch of mercury column (±0.17 kPa).
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Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
Item measured
Instrument accuracy
Water pressure ...................................................
±1.0 pounds per square inch (±6.9 kPa) .........
3.2 Temperature Measurement
3.2.1 Measurement. Temperature
measurements shall be made in accordance
with the Standard Method for Temperature
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
3.2.3 Scale Division. In no case shall the
smallest scale division of the instrument or
instrument system exceed 2 times the
specified precision.
3.2.4 Temperature Difference.
Temperature difference between the entering
and leaving water may be measured with any
of the following:
a. A thermopile
b. Calibrated resistance thermometers
c. Precision thermometers
d. Calibrated thermistors
e. Calibrated thermocouples
f. Quartz thermometers
3.2.5 Thermopile Construction. If a
thermopile is used, it shall be made from
calibrated thermocouple wire taken from a
single spool. Extension wires to the recording
device shall also be made from that same
spool.
3.2.6 Time constant. The time constant of
the instruments used to measure the inlet
and outlet water temperatures shall be no
greater than 2 seconds.
3.3 Liquid Flow Rate Measurement. The
accuracy of the liquid flow rate
measurement, using the calibration if
furnished, shall be equal to or less than ±1%
of the measured value in mass units per unit
time.
3.4 Electrical Energy. The electrical
energy used shall be measured with an
instrument and associated readout device
that is accurate within ±0.5% of the reading.
3.5 Fossil Fuels. The quantity of fuel used
by the water heater shall be measured with
an instrument and associated readout device
that is accurate within ±1% of the reading.
3.6 Mass Measurements. For mass
measurements greater than or equal to 10
pounds (4.5 kg), a scale that is accurate
within ±0.5% of the reading shall be used to
make the measurement. For mass
measurements less than 10 pounds (4.5 kg),
the scale shall provide a measurement that is
accurate within ±0.1 pound (0.045 kg).
3.7 Heating Value. The higher heating
value of the natural gas, propane, or fuel oil
shall be measured with an instrument and
associated readout device that is accurate
within ±1% of the reading. The heating
values of natural gas and propane must be
corrected from those reported at standard
temperature and pressure conditions to
provide the heating value at the temperature
and pressure measured at the fuel meter.
17:46 Nov 01, 2013
±0.50 pounds per square inch (±3.45 kPa).
including their associated readout devices,
shall be within the following limits:
Instrument accuracy
Air dry bulb temperature ....................................
Air wet bulb temperature ....................................
Inlet and outlet water temperatures ...................
Storage tank temperatures .................................
VerDate Mar<15>2010
Instrument precision
Measurement, ASHRAE Standard 41.1–1986
(RA 2006).
3.2.2 Accuracy and Precision. The
accuracy and precision of the instruments,
Item measured
Jkt 232001
±0.2
±0.2
±0.2
±0.5
°F
°F
°F
°F
(±0.1
(±0.1
(±0.1
(±0.3
°C)
°C)
°C)
°C)
Instrument precision
..............................................
..............................................
..............................................
..............................................
3.8 Time. The elapsed time
measurements shall be measured with an
instrument that is accurate within ±0.5
seconds per hour.
3.9 Volume. Volume measurements shall
be measured with an accuracy of ±2% of the
total volume.
3.10 Relative Humidity. If a relative
humidity (RH) transducer is used to measure
the relative humidity of the surrounding air
while testing heat pump water heaters, the
relative humidity shall be measured with an
accuracy of ±1.5% RH.
4. Installation
4.1 Water Heater Mounting. A water
heater designed to be freestanding shall be
placed on a 3⁄4 inch (2 cm) thick plywood
platform supported by three 2 × 4 inch (5 cm
× 10 cm) runners. If the water heater is not
approved for installation on combustible
flooring, suitable non-combustible material
shall be placed between the water heater and
the platform. Counter-top water heaters shall
be placed against a simulated wall section.
Wall-mounted water heaters shall be
supported on a simulated wall in accordance
with the manufacturer-published installation
instructions. When a simulated wall is used,
the construction shall be 2 × 4 inch (5 cm ×
10 cm) studs, faced with 3⁄4 inch (2 cm)
plywood. For heat pump water heaters not
delivered as a single package, the units shall
be connected in accordance with the
manufacturer-published installation
instructions and the overall system shall be
placed on the above-described plywood
platform. If installation instructions are not
provided by the heat pump manufacturer,
uninsulated 8 foot (2.4 m) long connecting
hoses having an inside diameter of 5⁄8 inch
(1.6 cm) shall be used to connect the storage
tank and the heat pump water heater. The
testing of the water heater shall occur in an
area that is protected from drafts of more
than 50 ft/ min (2.5 m/s) from room
ventilation registers, windows, or other
external sources of air movement.
4.2 Water Supply. Connect the water
heater to a water supply capable of delivering
water at conditions as specified in Sections
2.3 and 2.6 of this appendix.
4.3 Water Inlet and Outlet Configuration.
For freestanding water heaters that are taller
than 36 inches (91.4 cm), inlet and outlet
piping connections shall be configured in a
manner consistent with Figures 1 and 2. Inlet
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66233
±0.1 °F (±0.06 °C).
±0.1 °F (±0.06 °C).
±0.1 °F (±0.06 °C).
±0.25 °F (±0.14 °C).
and outlet piping connections for wallmounted water heaters shall be consistent
with Figure 3. For freestanding water heaters
that are 36 inches or less in height and not
supplied as part of a counter-top enclosure
(commonly referred to as an under-thecounter model), inlet and outlet piping shall
be installed in a manner consistent with
Figures 4, 5, and 6. For water heaters that are
supplied with a counter-top enclosure, inlet
and outlet piping shall be made in a manner
consistent with Figures 7A and 7B,
respectively. The vertical piping noted in
Figures 7A and 7B shall be located (whether
inside the enclosure or along the outside in
a recessed channel) in accordance with the
manufacturer-published installation
instructions.
All dimensions noted in Figures 1 through
7 shall be achieved. All piping between the
water heater and inlet and outlet temperature
sensors, noted as TIN and TOUT in the figures,
shall be Type ‘‘L’’ hard copper having the
same diameter as the connections on the
water heater. Unions may be used to facilitate
installation and removal of the piping
arrangements. A pressure gauge and
diaphragm expansion tank shall be installed
in the supply water piping at a location
upstream of the inlet temperature sensor. An
appropriately rated pressure and temperature
relief valve shall be installed on all water
heaters at the port specified by the
manufacturer. Discharge piping for the relief
valve shall be non-metallic. If heat traps,
piping insulation, or pressure relief valve
insulation are supplied with the water heater,
they shall be installed for testing. Except
when using a simulated wall, clearance shall
be provided such that none of the piping
contacts other surfaces in the test room.
4.4 Fuel and/or Electrical Power and
Energy Consumption. Install one or more
instruments that measure, as appropriate, the
quantity and rate of electrical energy and/or
fossil fuel consumption in accordance with
section 3.
4.5 Internal Storage Tank Temperature
Measurements. For water heaters with rated
storage volumes greater than or equal to 20
gallons, install six temperature measurement
sensors inside the water heater tank with a
vertical distance of at least 4 inches (100 mm)
between successive sensors. For water
heaters with rated storage volumes between
2 and 20 gallons, install three temperature
measurement sensors inside the water heater
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Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
tank. A temperature sensor shall be
positioned at the vertical midpoint of each of
the six equal volume nodes within a tank
larger than 20 gallons or the three equal
volume nodes within a tank between 2 and
20 gallons. Nodes designate the equal
volumes used to evenly partition the total
volume of the tank. As much as is possible,
the temperature sensor should be positioned
away from any heating elements, anodic
protective devices, tank walls, and flue pipe
walls. If the tank cannot accommodate six
temperature sensors and meet the installation
requirements specified above, install the
maximum number of sensors which comply
with the installation requirements. The
temperature sensors shall be installed either
through: (1) The anodic device opening; (2)
the relief valve opening; or (3) the hot water
outlet. If installed through the relief valve
opening or the hot water outlet, a tee fitting
or outlet piping, as applicable, shall be
installed as close as possible to its original
location. If the relief valve temperature
sensor is relocated, and it no longer extends
into the top of the tank, a substitute relief
valve that has a sensing element that can
reach into the tank shall be installed. If the
hot water outlet includes a heat trap, the heat
trap shall be installed on top of the tee fitting.
Added fittings shall be covered with thermal
insulation having an R value between 4 and
8 h·ft2·°F/Btu (0.7 and 1.4 m2·°C/W).
4.6 Ambient Air Temperature
Measurement. Install an ambient air
temperature sensor at the vertical mid-point
of the water heater and approximately 2 feet
(610 mm) from the surface of the water
heater. The sensor shall be shielded against
radiation.
4.7 Inlet and Outlet Water Temperature
Measurements. Install temperature sensors in
the cold-water inlet pipe and hot-water outlet
pipe as shown in Figures 1, 2, 3, 4, 5, 6, 7a,
and 7b, as applicable.
4.8 Flow Control. A valve or valves shall
be installed to provide flow as specified in
sections 5.2.4.1 and 5.4 for storage tank water
heaters and sections 5.3.1 and 5.4 for
instantaneous water heaters.
4.9 Flue Requirements.
4.9.1 Gas-Fired Water Heaters. Establish a
natural draft in the following manner. For
gas-fired water heaters with a vertically
discharging draft hood outlet, a 5-foot (1.5meter) vertical vent pipe extension with a
diameter equal to the largest flue collar size
of the draft hood shall be connected to the
draft hood outlet. For gas-fired water heaters
with a horizontally discharging draft hood
outlet, a 90-degree elbow with a diameter
equal to the largest flue collar size of the draft
hood shall be connected to the draft hood
outlet. A 5-foot (1.5-meter) length of vent
pipe shall be connected to the elbow and
oriented to discharge vertically upward.
Direct vent gas-fired water heaters shall be
installed with venting equipment specified in
the manufacturer’s instructions using the
minimum vertical and horizontal lengths of
vent pipe recommended by the manufacturer.
4.9.2 Oil-Fired Water Heaters. Establish a
draft at the flue collar at the value specified
in the manufacturer’s instructions. Establish
the draft by using a sufficient length of vent
pipe connected to the water heater flue
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outlet, and directed vertically upward. For an
oil-fired water heater with a horizontally
discharging draft hood outlet, a 90-degree
elbow with a diameter equal to the largest
flue collar size of the draft hood shall be
connected to the draft hood outlet. A length
of vent pipe sufficient to establish the draft
shall be connected to the elbow fitting and
oriented to discharge vertically upward.
Direct-vent oil-fired water heaters should be
installed with venting equipment as specified
in the manufacturer’s instructions, using the
minimum vertical and horizontal lengths of
vent pipe recommended by the manufacturer.
5. Test Procedures
5.1 Operational Mode Selection. For
water heaters that allow for multiple userselected operational modes, all procedures
specified in this appendix shall be carried
out with the water heater in the same
operational mode (i.e., only one mode). This
operational mode shall be the default mode
(or similarly-named, suggested mode for
normal operation) as defined by the
manufacturer in its product literature for
giving selection guidance to the consumer.
For heat pump water heaters, if a default
mode is not defined in the product literature,
each test shall be conducted under an
operational mode in which both the heat
pump and any electric resistance backup
heating element(s) are activated by the unit’s
control scheme, and which can achieve the
internal storage tank temperature specified in
this test procedure; if multiple operational
modes meet these criteria, the water heater
shall be tested under the most energyintensive mode. If no default mode is
specified and the unit does not offer an
operational mode that utilizes both the heat
pump and the electric resistance backup
heating element(s), the first-hour rating test
and the simulated-use test shall be tested in
heat-pump-only mode. For other types of
water heaters where a default mode is not
specified, test the unit in the most energyintensive mode.
5.2 Storage-type Water Heaters, Including
Heat Pump Water Heaters.
5.2.1 Determination of Storage Tank
Volume. Determine the storage capacity, Vst,
of the water heater under test, in gallons
(liters), by subtracting the tare weight—
measured while the tank is empty—from the
gross weight of the storage tank when
completely filled with water (with all air
eliminated and line pressure applied as
described in section 2.5) and dividing the
resulting net weight by the density of water
at the measured temperature.
5.2.2 Setting the Thermostat.
5.2.2.1 Single Thermostat Tanks.
5.2.2.1.1 Water Heaters with Rated
Volumes Less than 20 Gallons. Starting with
a tank at the supply water temperature,
initiate normal operation of the water heater.
After cut-out, initiate a draw from the water
heater at a flow rate of 1.0 gallon ± 0.25
gallons per minute (3.8 liters ± 0.95 liters per
minute) for 2 minutes. Starting 15 seconds
after commencement of draw, record the
outlet temperature at 15-second intervals
until the end of the 2-minute period.
Determine whether the maximum outlet
temperature is within the range of 125 °F ±
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5 °F (51.7 °C ± 2.8 °C). If not, turn off the
water heater, adjust the thermostat, and then
drain and refill the tank with supply water.
Then, once again, initiate normal operation
of the water heater, and repeat the 2-minute
outlet temperature test following cut-out.
Repeat this sequence until the maximum
outlet temperature during the 2-minute test is
within of 125 °F ± 5 °F (51.7 °C ± 2.8 °C).
5.2.2.1.2 Water Heaters with Rated
Volumes Greater than or Equal to 20 Gallons.
Starting with a tank at the supply water
temperature, initiate normal operation of the
water heater. After cut-out, initiate a draw
from the water heater at a flow rate of 1.7
gallons ± 0.25 gallons per minute (6.4 liters
± 0.95 liters per minute) for 5 minutes.
Starting 15 seconds after commencement of
draw, record the outlet temperature at 15second intervals until the end of the 5minute period. Determine whether the
maximum outlet temperature is within the
range of 125 °F ± 5 °F (51.7 °C ± 2.8 °C). If
not, turn off the water heater, adjust the
thermostat, and then drain and refill the tank
with supply water. Then, once again, initiate
normal operation of the water heater, and
repeat the 5-minute outlet temperature test
following cut-out. Repeat this sequence until
the maximum outlet temperature during the
5-minute test is within of 125 °F ± 5 °F (51.7
°C ± 2.8 °C).
5.2.2.2 Tanks with Two or More
Thermostats. Follow the same sequence as
for a single thermostat tank (i.e., start at the
supply water temperature; operate normally
until cut-out). Determine if the setting of the
thermostat that controls the uppermost
heating elements yields a maximum water
temperature of 125 °F ± 5 °F (51.7 °C ± 2.8
°C), as measured by the in-tank sensors that
are positioned above the uppermost heating
element. If the tank temperature above the
uppermost heating element is not within 125
°F ± 5 °F (51.7 °C ± 2.8 °C), turn off the water
heater, adjust the thermostat, and then drain
and refill the tank with supply water. The
thermostat that controls the heating element
positioned next highest in the tank shall then
be set to yield a maximum water temperature
of 125 °F ± 5 °F (51.7 °C ± 2.8 °C). This
process shall be repeated for the remaining
heating elements in reverse order of height
until the thermostat controlling the lowest
element is correctly adjusted. When adjusting
the thermostat that controls the lowest
element, the maximum mean tank
temperature after cut-out, as determined
using all the in-tank sensors, shall be 125 °F
± 5 °F (51.7 °C ± 2.8 °C). When adjusting all
other thermostats, use only the in-tank
temperature sensors positioned above the
heating element in question to evaluate the
maximum mean water temperature as
measured by these sensors after cut-out. For
heat pump water heaters that control an
auxiliary resistive element, the thermostat
shall be set in accordance with the
manufacturer’s installation instructions.
5.2.3 Power Input Determination. For all
water heaters except electric types, initiate
normal operation (as described in section 5.1)
and determine the power input, P, to the
main burners (including pilot light power, if
any) after 15 minutes of operation. If the
water heater is equipped with a gas appliance
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pressure regulator, the regulator outlet
pressure shall be set within ±10% of that
recommended by the manufacturer. For oilfired water heaters, the fuel pump pressure
shall be within ±10% of the manufacturer’s
specified pump pressure. All burners shall be
adjusted to achieve an hourly Btu (kJ) rating
that is within ±2% of the value specified by
the manufacturer. For an oil-fired water
heater, adjust the burner to give a CO2
reading recommended by the manufacturer
and an hourly Btu (kJ) rating that is within
±2% of that specified by the manufacturer.
Smoke in the flue may not exceed No. 1
smoke as measured by the procedure in
ASTM–D–2156–09.
5.2.4 First-Hour Rating Test.
5.2.4.1 General. During hot water draws
for water heaters with rated storage volumes
greater than or equal to 20 gallons, remove
water at a rate of 3.0 ± 0.25 gallons per
minute (11.4 ± 0.95 liters per minute). During
hot water draws, for storage-type water
heaters with rated storage volumes below 20
gallons, remove water at a rate of 1.0 ± 0.25
gallon per minute ((3.8 ± 0.95 liters per
minute). Collect the water in a container that
is large enough to hold the volume removed
during an individual draw and suitable for
weighing at the termination of each draw.
Alternatively, a water meter may be used to
directly measure the water volume(s)
withdrawn.
5.2.4.2 Draw Initiation Criteria. Begin the
first-hour rating test by imposing a draw on
the storage-type water heater. After
completion of this first draw, initiate
successive draws based on the following
criteria. For gas-fired and oil-fired water
heaters, initiate successive draws when the
thermostat acts to reduce the supply of fuel
to the main burner. For electric water heaters
having a single element or multiple elements
that all operate simultaneously, initiate
successive draws when the thermostat acts to
reduce the electrical input supplied to the
element(s). For electric water heaters having
two or more elements that do not operate
simultaneously, initiate successive draws
when the applicable thermostat acts to
reduce the electrical input to the element
located vertically highest in the storage tank.
For heat pump water heaters that do not use
supplemental resistive heating, initiate
successive draws immediately after the
electrical input to the compressor is reduced
by the action of the water heater’s thermostat.
For heat pump water heaters that use
supplemental resistive heating, initiate
successive draws immediately after the
electrical input to the compressor or the
uppermost resistive element is reduced by
the action of the applicable water heater
thermostat. This draw initiation criterion for
heat pump water heaters that use
supplemental resistive heating, however,
shall only apply when the water located
above the thermostat at cut-out is heated to
125 °F ± 5 °F (51.7 °C ± 2.8 °C).
5.2.4.3 Test Sequence. Establish normal
water heater operation. If the water heater is
not presently operating, initiate a draw. The
draw may be terminated any time after cutin occurs. After cut-out occurs (i.e., all
thermostats are satisfied), monitor the
internal storage tank temperature sensors
described in section 4.5 every minute and
determine the mean tank temperature by
averaging the values from these sensors.
Initiate a draw after a maximum mean tank
temperature (the maximum of the mean
temperatures of the individual sensors) has
been observed following a cut-out. Record
the time when the draw is initiated and
designate it as an elapsed time of zero (t* =
0). (The superscript * is used to denote
variables pertaining to the first-hour rating
test). Record the outlet water temperature
beginning 15 seconds after the draw is
initiated and at 5-second intervals thereafter
until the draw is terminated. Determine the
maximum outlet temperature that occurs
during this first draw and record it as T*max,1.
For the duration of this first draw and all
successive draws, in addition, monitor the
inlet temperature to the water heater to
ensure that the required 58 °F ± 2 °F (14.4
°C ± 1.1 °C) test condition is met. Terminate
the hot water draw when the outlet
temperature decreases to T*max,1¥15 °F
(T*max,1¥8.3 °C). Record this temperature as
T*min,1. Following draw termination,
determine the average outlet water
temperature and the mass or volume
removed during this first draw and record
them as T*del,i and M*1 or V*1, respectively.
Initiate a second and, if applicable,
successive draw each time the applicable
66235
draw initiation criteria described in section
5.2.4.2 are satisfied. As required for the first
draw, record the outlet water temperature 15
seconds after initiating each draw and at 5second intervals thereafter until the draw is
terminated. Determine the maximum outlet
temperature that occurs during each draw
and record it as T*max,i, where the subscript
i refers to the draw number. Terminate each
hot water draw when the outlet temperature
decreases to T*max,i¥15 °F (T*max,i¥8.3 °C).
Record this temperature as T*min,i. Calculate
and record the average outlet temperature
and the mass or volume removed during each
draw (T*del,i and M*i or V*i, respectively).
Continue this sequence of draw and recovery
until one hour has elapsed, then shut off the
electrical power and/or fuel supplied to the
water heater.
If a draw is occurring at an elapsed time
of one hour, continue this draw until the
outlet temperature decreases to T*max,n¥15
°F (T*max,n¥8.3 °C), at which time the draw
shall be immediately terminated. (The
subscript n shall be used to denote quantities
associated with the final draw.) If a draw is
not occurring at an elapsed time of one hour,
a final draw shall be imposed at one hour.
This draw shall proceed for a minimum of 30
seconds and shall be immediately terminated
thereafter when the outlet temperature first
indicates a value less than or equal to the cutoff temperature used for the previous draw
(T*min,n¥1). If an outlet temperature greater
than T*min,n-1 is not measured within 30
seconds zero additional credit shall be given
towards first-hour rating (i.e., M*n = 0 or V*n
= 0) based on the final draw. After the final
draw is terminated, calculate and record the
average outlet temperature and the mass or
volume removed during the draw (T*del,n and
M*n or V*n, respectively).
5.2.5 24-Hour Simulated Use Test.
5.2.5.1 Selection of Draw Pattern. The
water heater will be tested under a draw
profile that depends upon the rated first-hour
rating obtained following the test prescribed
in section 5.2.4 of this appendix. One of four
different patterns shall be applied based on
the rated first-hour rating, as shown in Table
I.
TABLE I—DRAW PATTERN TO BE USED FOR STORAGE WATER HEATERS BASED ON RATED FIRST-HOUR RATING
Rated first-hour rating greater than or equal to:
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
0 ...................................................................................
20 .................................................................................
55 .................................................................................
80 .................................................................................
After completing the first-hour rating test
in section 5.2.4, identify the appropriate
draw pattern using Table I above. The draw
patterns are provided in Tables III.1 through
III.4 in section 5.4. Use the appropriate draw
pattern when conducting the test sequence
provided in section 5.2.5.2.
5.2.5.2 Test Sequence. If the water heater
is turned off, fill the water heater with supply
water and apply pressure as described in
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20
55
80
No
................................................................................
................................................................................
................................................................................
upper limit ..............................................................
section 2.6. Turn on the water heater and
associated heat pump unit, if present. If the
water heater is turned on, initiate a water
draw that energizes the lowest heating
element in the water heater. In either case,
after the cut-out occurs, begin a 24-hour preconditioning period that draws water in the
pattern specified by Table I (i.e., using Table
III.1, Table III.2, Table III.3, or Table III.4,
depending on the rated first-hour rating). No
PO 00000
Draw pattern to be used in
simulated use test
. . . and rated first-hour rating less than:
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Point-of-Use (Table III.1).
Low-Usage (Table III.2).
Medium-Usage (Table III.3).
High-Usage (Table III.4).
data need to be recorded during this 24-hour
pre-conditioning period. At the end of this
period, the 24-hour simulated-use test will
begin.
At the start of the 24-hour test (after the 24hour pre-conditioning period), record the
mean tank temperature (T0), and the
electrical and/or fuel measurement readings,
as appropriate. Begin the 24-hour simulated
use test by withdrawing the volume specified
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in the appropriate table in section 5.4 (i.e.,
Table III.1, Table III.2, Table III.3, or Table
III.4, depending on the rated first-hour rating)
for the first draw at the flow rate specified.
Record the time when this first draw is
initiated and assign it as the test elapsed time
(t) of zero (0). Record the average storage tank
and ambient temperature every minute
throughout the 24-hour simulated use test. At
the elapsed times specified in the applicable
draw pattern table in section 5.4 for a
particular draw pattern, initiate additional
draws, removing the volume of hot water at
the prescribed flow rate specified by the
table. The maximum allowable deviation for
any single draw is ± 0.25 gallons (1.9 liters).
The quantity of water withdrawn during the
last draw shall be increased or decreased as
necessary such that the total volume of water
withdrawn equals the prescribed daily
amount for that draw pattern ± 1.0 gallon (±
3.8 liters).
All draws during the 24-hour simulated
use test shall be made at the flow rates
specified in the applicable draw pattern table
in section 5.4, within a tolerance of ± 0.25
gallons per minute (± 0.95 liters per minute).
Measurements of the inlet and outlet
temperatures shall be made 5 seconds after
the draw is initiated and at every subsequent
3-second interval throughout the duration of
each draw. The arithmetic mean of the hot
water discharge temperature and the cold
water inlet temperature shall be determined
for each draw (Tdel,i and Tin,i). Determine and
record the net mass or volume removed (Mi
or Vi), as appropriate, after each draw.
At the end of the first recovery period
following the first draw, which may extend
beyond subsequent draws, record the
maximum mean tank temperature observed
after cut-out, Tmax,1, and the energy
consumed by an electric resistance, gas or
oil-fired water heater (including electrical
energy), from the beginning of the test, Qr.
For heat pump water heaters, the total
electrical energy consumed during the first
recovery by the heat pump (including
compressor, fan, controls, pump, etc.) and, if
applicable, by the resistive element(s) shall
be recorded as Qr.
At the end of the recovery period that
follows the draw notated in the applicable
draw pattern table in section 5.4 as the end
of the first draw cluster during the test,
determine and record the total electrical
energy and/or fossil fuel consumed since the
beginning of the test, Qsu,0. In preparation for
determining the energy consumed during
standby, record the reading given on the
electrical energy (watt-hour) meter, the gas
meter, and/or the scale used to determine oil
consumption, as appropriate. Record the
maximum value of the mean tank
temperature after cut-out as Tsu,0. The time at
which this value is attained is the start of the
standby period. At 1-minute intervals, record
the mean tank temperature and the electric
and/or fuel instrument readings until the
next draw is initiated. Just prior to initiation
of the next draw, record the mean tank
temperature as Tsu,f. If the water heater is
undergoing recovery when the next draw is
initiated, record the mean tank temperature
Tsu,f at the minute prior to the start of the
recovery. The time at which this value occurs
is the end of the standby period. Determine
the total electrical energy and/or fossil fuel
energy consumption from the beginning of
the test to this time and record as Qsu,f.
Record the time interval between the time at
which the maximum mean tank temperature
is observed after the final draw of the first
draw cluster and the end of the standby
period as tstby,1. Record the time during
which water is not being withdrawn from the
water heater during the entire 24-hour period
as tstby,2.
5.3 Instantaneous Gas and Electric Water
Heaters
5.3.1 Setting the Outlet Discharge
Temperature. Initiate normal operation of the
water heater at the full input rating for
electric instantaneous water heaters and at
the maximum firing rate specified by the
manufacturer for gas instantaneous water
heaters. Monitor the discharge water
temperature and set to a value of 125 °F ±
5 °F (51.7 °C ± 2.8 °C) in accordance with the
manufacturer’s instructions. If the water
heater is not capable of providing this
discharge temperature when the flow rate is
1.7 gallons ± 0.25 gallons per minute (7.6
liters ± 0.95 liters per minute), then adjust
the flow rate as necessary to achieve the
specified discharge water temperature.
5.3.2 Maximum gpm Rating Test for
Instantaneous Water Heaters. Establish
normal water heater operation at the full
input rate for electric instantaneous water
heaters and at the maximum firing rate for
gas instantaneous water heaters with the
discharge water temperature set in
accordance with section 5.3.1. During the 10minute test, either collect the withdrawn
water for later measurement of the total mass
removed, or alternatively, use a water meter
to directly measure the water volume
removed.
After recording the scale or water meter
reading, initiate water flow through the water
heater, record the inlet and outlet water
temperatures beginning 15 seconds after the
start of the test and at subsequent 5-second
intervals throughout the duration of the test.
At the end of 10 minutes, turn off the water.
Determine the mass of water collected, M10m,
in pounds (kilograms), or the volume of
water, V10m, in gallons (liters).
5.3.3 24-hour Simulated Use Test for
Instantaneous Water Heaters.
5.3.3.1 Selection of Draw Pattern. The
water heater will be tested under a draw
profile that depends upon the rated
maximum gpm rating obtained following the
test prescribed in section 5.3.2. Four different
patterns can be applied, and Table II shows
which draw pattern is applied to a water
heater based on its rated maximum gpm
rating.
TABLE II—DRAW PATTERN TO BE USED FOR INSTANTANEOUS WATER HEATER BASED ON RATED MAXIMUM GPM RATING
. . . and rated maximum GPM rating less than:
0 ...........................................
1.7 ........................................
2.8 ........................................
4 ...........................................
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Rated maximum gpm rating
greater than or equal to:
1.7 ...................................................................................
2.8 ...................................................................................
4 ......................................................................................
No upper limit ..................................................................
The draw patterns are provided in Tables
III.1 through III.4 in section 5.4. Use the
appropriate draw pattern when conducting
the test sequence set forth in section 5.3.3.2.
5.3.3.2 Test Sequence. Establish normal
operation with the discharge water
temperature at 125 °F ± 5 °F (51.7 °C ± 2.8 °C)
and set the flow rate set as determined in
section 5.2. Prior to commencement of the
24-hour simulated use test, the unit shall
remain in an idle state in which controls are
active but no water is drawn through the unit
for a period of one hour. With no draw
occurring, record the reading given by the gas
meter and/or the electrical energy meter as
appropriate. Begin the 24-hour simulated use
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Draw pattern to be used in simulated use test
Point-of-Use (Table III.1).
Low-Usage (Table III.2).
Medium-Usage (Table III.3).
High-Usage (Table III.4).
test by withdrawing the volume specified in
Table III.1 through III.4 for the first draw at
the flow rate specified. Record the time when
this first draw is initiated and designate it as
an elapsed time, t, of 0. At the elapsed times
specified in Table III.1 through III.4 for a
particular draw pattern, initiate additional
draws, removing the volume of hot water at
the prescribed flow rate specified in Table
III.1 through III.4, with the maximum
allowable deviation for any single draw being
± 0.5 gallons (1.9 liters). The quantity of
water drawn during the final draw shall be
increased or decreased as necessary such that
the total volume of water withdrawn equals
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the prescribed daily amount for that draw
pattern ± 1.0 gallon (± 3.8 liters).
Measurements of the inlet and outlet water
temperatures shall be made 5 seconds after
the draw is initiated and at every 3-second
interval thereafter throughout the duration of
the draw. The arithmetic mean of the hot
water discharge temperature and the cold
water inlet temperature shall be determined
for each draw. Record the scale used to
measure the mass of the withdrawn water or
the water meter reading, as appropriate, after
each draw. At the end of the recovery period
following the first draw, determine and
record the fossil fuel and/or electrical energy
consumed, Qr. Following the final draw and
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subsequent recovery, allow the water heater
to remain in the standby mode until exactly
24 hours have elapsed since the start of the
test (i.e., since t = 0). At 24 hours, record the
reading given by the gas meter and/or the
electrical energy meter as appropriate.
Determine the fossil fuel and/or electrical
energy consumed during the entire 24-hour
66237
sections 5.2.5.1 and 5.3.3.1, respectively.
Each draw pattern specifies the elapsed time
in hours and minutes during the 24-hour test
when a draw is to commence, the total
volume of water in gallons (liters) that is to
be removed during each draw, and the flow
rate at which each draw is to be taken, in
gallons (liters) per minute.
simulated use test and designate the quantity
as Q.
5.4 Draw Patterns. The draw patterns to
be imposed during 24-hour simulated use
tests are provided in Tables III.1 through
III.4. Each water heater under test is to be
subjected to one of the draw patterns based
on its rated first-hour rating or rated
maximum gpm rating as discussed in
TABLE III.1—POINT-OF-USE DRAW PATTERN
Time during
test
[hh:mm]
Draw No.
1 * .................................................................................................................................................
2 * .................................................................................................................................................
3 * .................................................................................................................................................
4 * .................................................................................................................................................
5 * .................................................................................................................................................
6 ...................................................................................................................................................
7 ...................................................................................................................................................
8 ...................................................................................................................................................
9 ...................................................................................................................................................
0:00
1:00
1:05
1:10
1:15
8:00
8:15
9:00
9:15
Volume
[gallons (L)]
2.0
1.0
0.5
0.5
0.5
1.0
2.0
1.5
1.0
(7.6)
(3.8)
(1.9)
(1.9)
(1.9)
(3.8)
(7.6)
(5.7)
(3.8)
Flow rate **
[gpm (Lpm)]
1
1
1
1
1
1
1
1
1
(3.8)
(3.8)
(3.8)
(3.8)
(3.8)
(3.8)
(3.8)
(3.8)
(3.8)
Total Volume Drawn per Day: 10 gallons (38 L)
* Denotes draws in first draw cluster.
** Should the water heater have a rated maximum gpm rating less than 1 gpm (3.8 Lpm), then all draws shall be implemented at a flow rate
equal to the rated maximum gpm rating
TABLE III.2—LOW-USAGE DRAW PATTERN
Time during
test (hh:mm)
Draw No.
1 * .................................................................................................................................................
2 * .................................................................................................................................................
3 * .................................................................................................................................................
4 ...................................................................................................................................................
5 ...................................................................................................................................................
6 ...................................................................................................................................................
7 ...................................................................................................................................................
8 ...................................................................................................................................................
9 ...................................................................................................................................................
10 .................................................................................................................................................
11 .................................................................................................................................................
0:00
0:30
1:00
10:30
11:30
12:00
12:45
12:50
16:15
16:45
17:00
Volume
(gallons)
15.0 (56.8)
2.0 (7.6)
1.0 (3.8)
6.0 (22.7)
4.0 (15.1)
1.0 (3.8)
1.0 (3.8)
1.0 (3.8)
2.0 (7.6)
2.0 (7.6)
3.0 (11.4)
Flow rate
(gpm)
1.7
1
1
1.7
1.7
1
1
1
1
1.7
1.7
(6.4)
(3.8)
(3.8)
(6.4)
(6.4)
(3.8)
(3.8)
(3.8)
(3.8)
(6.4)
(6.4)
Total Volume Drawn per Day: 38 gallons (144 L)
* Denotes draws in first draw cluster.
TABLE III.3—MEDIUM-USAGE DRAW PATTERN
Time during
test
(hh:mm)
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Draw No.
1 * .................................................................................................................................................
2 * .................................................................................................................................................
3 * .................................................................................................................................................
4 ...................................................................................................................................................
5 ...................................................................................................................................................
6 ...................................................................................................................................................
7 ...................................................................................................................................................
8 ...................................................................................................................................................
9 ...................................................................................................................................................
10 .................................................................................................................................................
11 .................................................................................................................................................
12 .................................................................................................................................................
0:00
0:30
1:40
10:30
11:30
12:00
12:45
12:50
16:00
16:15
16:45
17:00
Total Volume Drawn Per Day: 55 gallons (208 L)
* Denotes draws in first draw cluster.
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Volume
(gallons)
15.0 (56.8)
2.0 (7.6)
9.0 (34.1)
9.0 (34.1)
5.0 (18.9)
1.0 (3.8)
1.0 (3.8)
1.0 (3.8)
1.0 (3.8)
2.0 (7.6)
2.0 (7.6)
7.0 (26.5)
Flow rate
(gpm)
1.7
1
1.7
1.7
1.7
1
1
1
1
1
1.7
1.7
(6.4)
(3.8)
(6.4)
(6.4)
(6.4)
(3.8)
(3.8)
(3.8)
(3.8)
(3.8)
(6.4)
(6.4)
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Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
TABLE III.4—HIGH-USAGE DRAW PATTERN
Time during
test
(hh:mm)
Draw No.
1 * .................................................................................................................................................
2 * .................................................................................................................................................
3 * .................................................................................................................................................
4 * .................................................................................................................................................
5 ...................................................................................................................................................
6 ...................................................................................................................................................
7 ...................................................................................................................................................
8 ...................................................................................................................................................
9 ...................................................................................................................................................
10 .................................................................................................................................................
11 .................................................................................................................................................
12 .................................................................................................................................................
13 .................................................................................................................................................
14 .................................................................................................................................................
0:00
0:30
0:40
1:40
10:30
11:30
12:00
12:45
12:50
16:00
16:15
16:30
16:45
17:00
Volume
(gallons)
27.0 (102)
2.0 (7.6)
1.0 (3.8)
9.0 (34.1)
15.0 (56.8)
5.0 (18.9)
1.0 (3.8)
1.0 (3.8)
1.0 (3.8)
2.0 (7.6)
2.0 (7.6)
2.0 (7.6)
2.0 (7.6)
14.0 (53.0)
Flow rate
(gpm)
3 (11.4)
1 (3.8)
1 (3.8)
1.7 (6.4)
3 (11.4)
1.7 (6.4)
1 (3.8)
1 (3.8)
1 (3.8)
1 (3.8)
1 (3.8)
1.7 (6.4)
1.7 (6.4)
3 (11.4)
Total Volume Drawn Per Day: 84 gallons (318 L)
* Denotes draws in first draw cluster.
6. Computations
6.1 Storage Tank and Heat Pump Water
Heaters
6.1.1 Storage Tank Capacity. The storage
tank capacity, Vst, is computed using the
following:
r = the density of water used to fill the tank
measured at the temperature of the
water, lb/gal (kg/L)
6.1.2 First-Hour Rating Computation. For
the case in which the final draw is initiated
at or prior to an elapsed time of one hour,
the first-hour rating, Fhr, shall be computed
using,
gal (L) or, if the mass of water is being
measured,
Where:
M1 = total mass removed from the start of the
24-hour simulated use test to the end of
the first recovery period, lb (kg), or, if the
volume of water is being measured,
M1 = V1r1
Where:
V1 = total volume removed from the start of
the 24-hour simulated use test to the end
of the first recovery period, gal (L).
r1 = density of the water at the water
temperature measured at the point where
the flow volume is measured, lb/gal (kg/
L).
Cp1 = specific heat of the withdrawn water
evaluated at (Tdel,1 + Tin,1)/2, Btu/(lb·°F)
(kJ/(kg·°C))
Tdel,1 = average water outlet temperature
measured during the draws from the start
of the 24-hour simulated use test to the
end of the first recovery period, °F (°C).
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EP04NO13.034
T*min,n-1 = the minimum water outlet
temperature measured during the (n-1)th
draw of the first-hour rating test, °F (°C).
6.1.3 Recovery Efficiency. The recovery
efficiency for gas, oil, and heat pump storagetype water heaters, hr, is computed as:
EP04NO13.033
T* del,n-1 = the average water outlet
temperature measured during the (n-1)th
draw of the first-hour rating test, °F (°C).
T* del,n = the average water outlet temperature
measured during the nth (final) draw of
the first-hour rating test, °F (°C).
EP04NO13.032
where n and V*i are the same quantities as
defined above, and
V*n = the volume of water drawn during the
nth (final) draw of the first-hour rating
test, gal (L)
Where:
Vst = the storage capacity of the water heater,
gal (L)
Wf = the weight of the storage tank when
completely filled with water, lb (kg)
Wt = the (tare) weight of the storage tank
when completely empty, lb (kg)
EP04NO13.030 EP04NO13.031
Where:
n = the number of draws that are completed
during the first-hour rating test
V*i = the volume of water removed during
the ith draw of the first-hour rating test,
Where:
M*i = the mass of water removed during the
ith draw of the first-hour rating test, lb
(kg).
r = the water density corresponding to the
average outlet temperature measured
during the ith draw, (T*del,i), lb/gal (kg/
L).
For the case in which a draw is not in
progress at the elapsed time of one hour and
a final draw is imposed at the elapsed time
of one hour, the first-hour rating shall be
calculated using
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
Tin,1 = average water inlet temperature
measured during the draws from the start
of the 24-hour simulated use test to the
end of the first recovery period, °F (°C).
Vst = as defined in section 6.1.1.
r2 = density of stored hot water evaluated at
(Tmax,1 + To)/2, lb/gal (kg/L).
Cp2 = specific heat of stored hot water
evaluated at (Tmax,1 + To)/2, Btu/(lb·°F)
(kJ/(kg·°C).
Tmax,1 = maximum mean tank temperature
recorded after cut-out following the first
recovery of the 24-hour simulated use
test, °F (°C).
To = maximum mean tank temperature
recorded prior to the first draw of the 24hour simulated use test, °F (°C).
Qr = the total energy used by the water heater
between cut-out prior to the first draw
and cut-out following the first recovery
period, including auxiliary energy such
as pilot lights, pumps, fans, etc., Btu (kJ).
(Electrical auxiliary energy shall be
converted to thermal energy using the
following conversion: 1 kWh = 3412
Btu).
The recovery efficiency for electric
water heaters with immersed heating
elements is assumed to be 98%.
6.1.4 Hourly Standby Losses. The
energy consumed as part of the standby
loss test of the 24-hour simulated use
test, Qstby, is computed as:
Qstby = Qsu,f¥Qsu,0
Where:
Qsu,0 = cumulative energy consumption of the
water heater from the start of the 24-hour
simulated use test to the time at which
the maximum mean tank temperature is
attained after the recovery following the
end of the first draw cluster, Btu (kJ).
Qsu,f = cumulative energy consumption of the
water heater from the start of the 24-hour
simulated use test to the minute prior to
the start of the draw following the end
of the first draw cluster or the minute
prior to a recovery occurring at the start
of the draw following the end of the first
draw cluster, Btu (kJ).
The standby heat loss coefficient for
the tank is computed as:
6.1.5 Daily Water Heating Energy
Consumption. The daily water heating
energy consumption, Qd, is computed
as:
Where:
Q = Qf + Qe = total energy used by the water
heater during the 24-hour simulated use
test, including auxiliary energy such as
pilot lights, pumps, fans, etc., Btu (kJ).
(Electrical energy shall be converted to
thermal energy using the following
conversion: 1kWh = 3412 Btu.)
Qf = total fossil fuel energy used by the water
heater during the 24-hour simulated use
test, Btu (kJ).
Qe = total electrical energy used during the
24-hour simulated use test, Btu (kJ).
Vst = as defined in section 6.1.1.
r = density of the stored hot water, evaluated
at (T24 + T0)/2, lb/gal (kg/L)
Cp = specific heat of the stored water,
evaluated at (T24 + T0)/2, Btu/(lb·F), (kJ/
(kg·K)).
T24 = mean tank temperature at the end of the
24-hour simulated use test, °F (°C).
T0 = mean tank temperature at the beginning
of the 24-hour simulated use test,
recorded one minute before the first
draw is initiated, °F (°C).
hr = as defined in section 6.1.3.
Where:
UA = standby heat loss coefficient of the
storage tank, Btu/(h·°F), (kJ/(h·°C).
Tt,stby,1 = overall average storage tank
temperature between the time when the
maximum mean tank temperature is
observed after cut-out following the first
draw cluster and the minute prior to
commencement of the next draw
following the first draw cluster of the 24hour simulated use test, °F (°C).
Ta,stby,1 = overall average ambient temperature
between the time when the maximum
mean tank temperature is observed after
cut-out following the first draw cluster
and the minute prior to commencement
of the next draw following the first draw
cluster of the 24-hour simulated use test,
°F (°C).
6.1.6 Adjusted Daily Water Heating
Energy Consumption. The adjusted
daily water heating energy
consumption, Qda, takes into account
that the temperature difference between
the storage tank and surrounding
ambient air may not be the nominal
value of 57.5 °F (125 °F¥67.5 °F) or
32.0 °C (51.7 °C¥19.7 °C) due to the 10
°F (5.6 °C) allowable variation in storage
tank temperature, 125 °F ± 5 °F (51.7 °C
± 2.8 °C), and the 5 °F (2.8 °C) allowable
variation in surrounding ambient
temperature 65 °F (18.3 °C) to 70 °C
(21.1 °C). The adjusted daily water
heating energy consumption is
computed as:
Tstby,2 = the mean tank temperature during
the total standby portion, tstby,2, of the
24-hour test, °F (°C).
Ta,stby,2 = the average ambient temperature
during the total standby portion, tstby,2, of
the 24-hour test, °F (°C).
UA = as defined in section 6.1.4.
EP04NO13.037
Where:
Qda = the adjusted daily water heating energy
consumption, Btu (kJ).
Qd = as defined in section 6.1.5.
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EP04NO13.035 EP04NO13.036
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
EP04NO13.038
The hourly standby energy losses are
computed as:
Where:
Qhr = the hourly standby energy losses of the
water heater, Btu/h (kJ/h).
Vst = as defined in section 6.1.1.
r = density of stored hot water, (Tsu,f + Tsu,0)/
2, lb/gal (kg/L).
Cp = specific heat of the stored water, (Tsu,f
+ Tsu,0)/2, Btu/(lb·F), (kJ/(kg·K))
Tsu,f = the mean tank temperature observed
at the minute prior to the start of the
draw following the first draw cluster or
the minute prior to a recovery occurring
at the start of the draw following the end
of the first draw cluster, °F (°C).
Tsu,0 = the maximum mean tank temperature
observed after the first recovery
following the final draw of the first draw
cluster, °F (°C).
hr = as defined in section 6.1.3.
tstby,1 = elapsed time between the time at
which the maximum mean tank
temperature is observed after the first
draw cluster and the minute prior to the
start of the first draw following the end
of the first draw cluster of the 24-hour
simulated use test or the minute prior to
a recovery occurring at the start of the
draw following the end of the first draw
cluster, h.
66239
66240
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
Where:
N = total number of draws in the draw
pattern.
Mi = the mass withdrawn for the ith draw (i
= 1 to N), lb (kg)
The difference between these two values is:
QHWD = QHW,67 °F¥QHW
or QHWD = QHW,37.3 °C¥QHW
This difference (QHWD) must be added to the
adjusted daily water heating energy
consumption value. Thus, the daily energy
consumption value which takes into account
that the temperature difference between the
storage tank and ambient temperature may
not be 57.5 °F (32.0 °C) and that the
temperature rise across the storage tank may
not be 67 °F (37.3 °C) is: Qdm = Qda + QHWD
6.1.7 Energy Factor. The energy factor, Ef,
is computed as:
Where:
N = total number of draws in the draw
pattern
Qdm = the modified daily water heating
energy consumption as computed in
accordance with section 6.1.6, Btu (kJ)
Mi = the mass withdrawn for the ith draw (i
= 1 to N), lb (kg)
Cpi = the specific heat of the water of the ith
draw, evaluated at (125 °F + 58 °F)/2 =
91.5 °F ((51.7°C + 14.4°C)/2 = 33 °C),
Btu/(lb·°F) (kJ/(kg·°C)).
6.1.8 Annual Energy Consumption. The
annual energy consumption for storage-type
and heat pump water heaters is computed as:
Where:
Ef = the energy factor as computed in
accordance with section 6.1.8
365 = the number of days in a year
V = the volume of hot water drawn during
the applicable draw pattern, gallons
= 10 for the point-of-use draw pattern
= 38 for the low usage draw pattern
= 55 for the medium usage draw pattern
= 84 for high usage draw pattern
r = 8.24 lbm/gallon, the density of water at
125 °F
CP = 1.00 Btu/lbm°F, the specific heat of
water at 91.5 °F
67 = the nominal temperature difference
between inlet and outlet water
6.1.9 Annual Electrical Energy
Consumption. The annual electrical energy
consumption in kilowatt-hours for storagetype and heat pump water heaters, Eannual,e, is
computed as:
Eannual,e = Eannual*(Qe/Q)/3412
Where:
Eannual = the annual energy consumption as
determined in accordance with section
6.1.8, Btu (kJ)
Qe = the daily electrical energy consumption
as defined in section 6.1.5, Btu (kJ).
Q = total energy used by the water heater
during the 24-hour simulated use test in
accordance with section 6.1.5, Btu (kJ)
3412 = conversion factor from Btu to kWh
6.1.10 Annual Fossil Fuel Energy
Consumption. The annual fossil fuel energy
consumption for storage-type and heat pump
water heaters, Eannual,f, is computed as:
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Cpi = the specific heat of the water of the ith
draw evaluated at (Tdel,i +Tin,i)/2, Btu/
(lb·°F) (kJ/(kg·°C)).
Tdel,i = the average water outlet temperature
measured during the ith draw (i = 1 to
N), °F (°C).
Tin,i = the average water inlet temperature
measured during the ith draw (i = 1 to
N), °F (°C).
hr = as defined in section 6.1.3.
The energy required to heat the same
quantity of water over a 67 °F (37.3 °C)
temperature rise, Btu/day (kJ/day), is:
EP04NO13.042
The energy used to heat water, Btu/day (kJ/
day), may be computed as:
EP04NO13.039 EP04NO13.040
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
tstby,2 = the number of hours during the 24hour simulated test when water is not
being withdrawn from the water heater.
A modification is also needed to take into
account that the temperature difference
between the outlet water temperature and
supply water temperature may not be
equivalent to the nominal value of 67 °F (125
°F¥58 °F) or 37.3 °C (51.7 °C¥14.4 °C). The
following equations adjust the experimental
data to a nominal 67 °F (37.3 °C) temperature
rise.
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
Eannual,f = Eannual¥(Eannual,e × 3412)
Where:
Eannual = the annual energy consumption as
determined in accordance with section
6.1.8, Btu (kJ)
Eannual,e = the annual electrical energy
consumption as determined in
accordance with section 6.1.9, kWh
3412 = conversion factor from kWh to Btu
6.2 Instantaneous Water Heaters.
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6.2.1 Maximum gpm (L/min) Rating
Computation. Compute the maximum gpm
(L/min) rating, Fmax, as:
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Where:
N = total number of draws in the draw
pattern
Mi = the mass withdrawn for the ith draw (i
= 1 to N), lb (kg)
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EP04NO13.047
EP04NO13.046
Where:
V10m = the volume of water measured during
the 10-minute test, gal (L).
Tdel = as defined in this section.
Tin = as defined in this section.
6.2.2 Recovery Efficiency. The recovery
efficiency, hr, is computed as:
Where:
M1 = total mass removed during the first
draw of the 24-hour simulated use test,
lb (kg), or, if the volume of water is being
measured,
M1 = V1 · r
Where:
V1 = total volume removed during the first
draw of the 24-hour simulated use test,
gal (L).
r = density of the water at the water
temperature measured at the point where
the flow volume is measured, lb/gal (kg/
L).
Cp1 = specific heat of the withdrawn water,
(Tdel,1 ¥ Tin,1)/2, Btu/(lb·°F) (kJ/(kg·°C)).
Tdel,1 = average water outlet temperature
measured during the first draw of the 24hour simulated use test, °F (°C).
Tin,1 = average water inlet temperature
measured during the first draw of the 24hour simulated use test, °F (°C).
Qr = the total energy used by the water heater
between cut-out prior to the first draw
and cut-out following the first draw,
including auxiliary energy such as pilot
lights, pumps, fans, etc., Btu (kJ).
(Electrical auxiliary energy shall be
converted to thermal energy using the
following conversion: 1 kWh = 3412
Btu.)
6.2.3 Daily Water Heating Energy
Consumption. The daily water heating energy
consumption, Qd, is computed as:
Qd = Q
Where:
Q = Qf + Qe = the energy used by the
instantaneous water heater during the
24-hour simulated use test.
Qf = total fossil fuel energy used by the water
heater during the 24-hour simulated use
test, Btu (kJ).
Qe = total electrical energy used during the
24-hour simulated use test, Btu (kJ).
A modification is needed to take into
account that the temperature difference
between the outlet water temperature and
supply water temperature may not be
equivalent to the nominal value of 67 °F (125
°F ¥ 58 °F) or 37.3 °C (51.7 °C ¥ 14.4 °C).
The following equations adjust the
experimental data to a nominal 67 °F (37.3
°C) temperature rise.
The energy used to heat water may be
computed as:
EP04NO13.044 EP04NO13.045
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Where:
M10m = the mass of water collected during the
10-minute test, lb (kg).
Tdel = the average delivery temperature, °F
(°C).
Tin = the average inlet temperature, °F (°C).
r = the density of water at the average
delivery temperature, lb/gal (kg/L).
If a water meter is used, the maximum gpm
(L/min) rating is computed as:
EP04NO13.048
which may be expressed as:
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The difference between these two values is:
QHWD = QHW,67°F ¥ QHW
or QHWD = QHW,37.3°C ¥ QHW
This difference (QHWD) must be added to the
adjusted daily water heating energy
consumption value. Thus, the daily energy
consumption value, which takes into account
that the temperature difference between the
storage tank and ambient temperature may
not be 57.5 °F (32.0 °C) and that the
temperature rise across the storage tank may
not be 67 °F (37.3 °C), is:
Qdm = Qd + QHWD
6.2.4 Energy Factor. The energy factor, Ef,
is computed as:
Where:
N = total number of draws in the draw
pattern
Qdm = the modified daily water heating
energy consumption as computed in
accordance with section 6.2.3, Btu (kJ)
Mi = the mass withdrawn for the ith draw (i
= 1 to N), lb (kg)
Cpi = the specific heat of the water at the ith
draw, evaluated at (125 °F + 58 °F)/2 =
91.5 °F ((51.7 °C + 14.4 °C)/2 = 33 °C),
Btu/(lb· °F) (kJ/(kg· °C)).
6.2.5 Annual Energy Consumption. The
annual energy consumption for
instantaneous-type water heaters, Eannual, is
computed as:
365 = the number of days in a year.
V = the volume of hot water drawn during
the applicable draw pattern, gallons
= 10 for the point-of-use draw pattern
= 38 for the low usage draw pattern
= 55 for the medium usage draw pattern
= 84 for high usage draw pattern
r = 8.24 lbm/gallon, the density of water at
125 °F
CP = 1.00 Btu/lbm °F, the specific heat of
water at 91.5 °F
67 = the nominal temperature difference
between inlet and outlet water
6.2.6 Annual Electrical Energy
Consumption. The annual electrical energy
consumption in kilowatt-hours for
instantaneous-type water heaters, Eannual, e, is
computed as:
Eannual,e = Eannual*(Qe/Q)/3412
Where:
Qe = the daily electrical energy consumption
as defined in section 6.2.3, Btu (kJ)
Eannual = the annual energy consumption as
determined in accordance with section
6.2.5, Btu (kJ)
Q = total energy used by the water heater
during the 24-hour simulated use test in
accordance with section 6.2.3, Btu (kJ)
Qdm = the modified daily water heating
energy consumption as computed in
accordance with section 6.2.3, Btu (kJ)
3412 = conversion factor from Btu to kWh
6.2.7 Annual Fossil Fuel Energy
Consumption. The annual fossil fuel energy
consumption for instantaneous-type water
heaters, Eannual,f, is computed as:
Eannual,f = Eannual ¥ (Eannual,e × 3412)
Where:
Eannual,e = the annual electrical energy
consumption as defined in section 6.2.6,
kWh.
Eannual = the annual energy consumption as
defined in section 6.2.5, Btu (kJ)
3412 = conversion factor from kWh to Btu
Where:
Ef = the energy factor as computed in
accordance with section 6.2.4
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The energy required to heat the same
quantity of water over a 67 °F (37.3 °C)
temperature rise is:
EP04NO13.049 EP04NO13.050
Tin,i = the average water inlet temperature
measured during the ith draw (i = 1 to
N), °F (°C).
hr = as defined in section 6.2.2.
Where:
N = total number of draws in the draw
pattern
Mi = the mass withdrawn during the ith
draw, lb (kg)
Cpi = the specific heat of water of the ith
draw, Btu/(lb·°F) (kJ/(kg·°C))
hr = as defined in section 6.2.2.
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Cpi = the specific heat of the water of the ith
draw evaluated at (Tdel,i + Tin,i)/2, Btu/
(lb·°F) (kJ/(kg·°C)).
Tdel,i = the average water outlet temperature
measured during the ith draw (i = 1 to
N), °F (°C).
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66246
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§ 430.32 Energy and water conservation
standards and their compliance dates.
*
*
*
*
*
10. Section 430.32 is amended by
revising paragraph (d) to read as
follows:
■
Product class
*
*
*
*
*
(d) Water heaters. The energy factor of
water heaters shall not be less than the
following for products manufactured on
or after the indicated dates.
Energy factor as of January 20, 2004
Storage volume
Gas-fired Storage Water
Heater.
≥ 20 gallons and ≤ 100
gallons.
0.67¥(0.0019 × Rated
Storage Volume in gallons).
Oil-fired Storage Water
Heater.
≤ 50 gallons .......................
Electric Storage Water Heater.
≥ 20 gallons and ≤ 120
gallons.
0.59¥(0.0019 × Rated
Storage Volume in gallons).
0.97¥(0.00132 × Rated
Storage Volume in gallons).
Tabletop Water Heater ........
≥ 20 gallons and ≤ 120
gallons.
Instantaneous Gas-fired
Water Heater.
< 2 gallons .........................
Instantaneous Electric Water
Heater.
< 2 gallons .........................
0.93¥(0.00132 × Rated
Storage Volume in gallons).
0.62¥(0.0019 × Rated
Storage Volume in gallons).
0.93¥(0.00132 × Rated
Storage Volume in gallons).
Energy factor as of April 16, 2015
For tanks with a Rated Storage Volume at or below 55
gallons: EF = 0.675¥(0.0015 × Rated Storage Volume in gallons).
For tanks with a Rated Storage Volume above 55 gallons: EF = 0.8012¥(0.00078 × Rated Storage Volume in gallons).
EF = 0.68¥(0.0019 × Rated Storage Volume in gallons).
For tanks with a Rated Storage Volume at or below 55
gallons: EF = 0.960¥(0.0003 × Rated Storage Volume in gallons). For tanks with a Rated Storage
Volume above 55 gallons: EF = 2.057¥(0.00113 ×
Rated Storage Volume in gallons).
EF = 0.93¥(0.00132 × Rated Storage Volume in gallons).
EF = 0.82¥(0.0019 × Rated Storage Volume in gallons).
EF = 0.93¥(0.00132 × Rated Storage Volume in gallons).
Note: The Rated Storage Volume equals the water storage capacity of a water heater, in gallons, as certified by the manufacturer.
Exclusions. The energy conservation
standards shown in this paragraph do
not apply to the following types of water
heaters: gas-fired, oil-fired, and electric
water heaters at or above 2 gallons
storage volume and below 20 gallons
storage volume; gas-fired water heaters
above 100 gallons storage volume; oilfired water heaters above 50 gallons
storage volume; electric water heaters
above 120 gallons storage volume; gasfired instantaneous water heaters at or
below 50,000 Btu/h.
*
*
*
*
*
PART 431—ENERGY EFFICIENCY
PROGRAM FOR CERTAIN
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
11. The authority citation for part 431
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317.
12. Section 431.102 is amended by
adding the definition of ‘‘Light
commercial water heater,’’ in
alphabetical order, to read as follows:
■
§ 431.102 Definitions concerning
commercial water heaters, hot water supply
boilers, and unfired hot water storage
tanks.
*
*
*
*
Light commercial water heater means
any gas-fired, electric, or oil storage or
instantaneous commercial water heater
that meets the following conditions:
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*
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(1) For models requiring electricity,
uses single-phase external power
supply;
(2) Is not capable of delivering hot
water at temperatures of 180 °F or
above; and
(3) Does not bear a Code Symbol
Stamp signifying compliance with the
requirements of the ASME Boiler and
Pressure Vessel Code.
*
*
*
*
*
■ 13. In § 431.106, paragraph (b), Table
2, is revised to read as follows:
§ 431.106 Uniform test method for the
measurement of energy efficiency of
commercial water heaters and hot water
supply boilers (other than commercial heat
pump water heaters).
*
*
*
(b) * * *
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*
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules
66247
TABLE 2 TO § 431.106—TEST PROCEDURES FOR COMMERCIAL WATER HEATERS AND HOT WATER SUPPLY BOILERS
[Other than commercial heat pump water heaters]
Equipment type
Energy efficiency
descriptor
Use test set-up,
equipment, and
procedures in
subsection labeled
‘‘Method of Test’’ of
Energy Factor ............
10 CFR 430, Subpt.
B, App. E.
Gas-fired Storage and
Instantaneous
Water Heaters and
Hot Water Supply
Boilers*.
Thermal Efficiency .....
ANSI Z21.10.3–
2011**, Exhibit G1.
ANSI Z21.10.3–
2011**, Exhibit G2.
Oil-fired Storage and
Instantaneous
Water Heaters and
Hot Water Supply
Boilers*.
Electric Storage and
Instantaneous
Water Heaters.
EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Light Commercial
Water Heater.
Thermal Efficiency .....
Standby Loss .............
Test procedure
required for
compliance on and
after
(insert date 365 days
after publication of
the final rule in the
Federal Register
that establishes a
conversion factor, or
December 31, 2015,
whichever is later).
May 13, 2013 .............
May 13, 2013.
May 13, 2013 .............
Standby Loss .............
ANSI Z21.10.3–
2011**, Exhibit G1.
ANSI Z21.10.3–
2011**, Exhibit G2.
Standby Loss .............
ANSI Z21.10.3–
2011**, Exhibit G2.
May 13, 2013 .............
May 13, 2013.
With these additional stipulations
None.
A. For all products, the duration of the standby loss test shall be until whichever of the
following occurs first after you begin to
measure the fuel and/or electric consumption: (1) The first cutout after 24 hours or
(2) 48 hours, if the water heater is not in
the heating mode at that time.
B. For oil and gas products, the standby loss
in Btu per hour must be calculated as follows: SL (Btu per hour) = S (% per hour) ×
8.25 (Btu/gal-F) × Measured Volume (gal)
× 70 (degrees F).
C. For oil-fired products, apply the following
in conducting the thermal efficiency and
standby loss tests: (1) Venting Requirements—Connect a vertical length of flue
pipe to the flue gas outlet of sufficient
height so as to meet the minimum draft
specified by the manufacturer. (2) Oil Supply—Adjust the burner rate so that: (a)
The hourly Btu input rate lies within ±2
percent of the manufacturer’s specified
input rate, (b) the CO2 reading shows the
value specified by the manufacturer, (c)
smoke in the flue does not exceed No. 1
smoke as measured by the procedure in
ASTM–D–2156–80, and (d) fuel pump
pressure lies within ±10 percent of manufacturer’s specifications.
D. For electric products, apply the following
in conducting the standby loss test: (1) Assume that the thermal efficiency (Et) of
electric water heaters with immersed heating elements is 98 percent. (2) Maintain
the electrical supply voltage to within ±5
percent of the center of the voltage range
specified on the water heater nameplate.
(3) If the set up includes multiple adjustable thermostats, set the highest one first
to yield a maximum water temperature in
the specified range as measured by the
topmost tank thermocouple. Then set the
lower thermostat(s) to yield a maximum
mean tank temperature within the specified range.
E. Install water-tube water heaters as shown
in Figure 2, ‘‘Arrangement for Testing
Water-tube Type Instantaneous and Circulating Water Heaters.’’
* As to hot water supply boilers with a capacity of less than 10 gallons, these test methods become mandatory on October 21, 2005. Prior to
that time, you may use for these products either (1) these test methods if you rate the product for thermal efficiency, or (2) the test methods in
Subpart E if you rate the product for combustion efficiency as a commercial packaged boiler.
** Incorporated by reference, see § 431.105.
14. Section 431.107 is added to read
as follows:
■
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TABLE 1 TO § 431.107—TEST PROCEDURES FOR COMMERCIAL HEAT PUMP WATER HEATERS
Equipment type
Energy efficiency
descriptor
Use test set-up,
equipment, and
procedures in
subsection labeled
‘‘Method of Test’’ of
Light Commercial Heat Pump Water Heater
with Integrated Storage Tank.
Energy Factor .........
10 CFR 430, Subpt. B,
App. E.
All Other Types ..................................................
[Reserved] ...............
[Reserved] ..................
Test procedure required for compliance on
and after
(insert date 365 days after publication of the
final rule in the Federal Register that establishes a conversion factor, or December
31, 2015, whichever is later)
[Reserved]
[FR Doc. 2013–26268 Filed 11–1–13; 8:45 am]
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Agencies
[Federal Register Volume 78, Number 213 (Monday, November 4, 2013)]
[Proposed Rules]
[Pages 66201-66248]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-26268]
[[Page 66201]]
Vol. 78
Monday,
No. 213
November 4, 2013
Part IV
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 Residential
and Commercial Water Heaters; Proposed Rule
Federal Register / Vol. 78 , No. 213 / Monday, November 4, 2013 /
Proposed Rules
[[Page 66202]]
-----------------------------------------------------------------------
DEPARTMENT OF ENERGY
10 CFR Parts 429, 430 and 431
[Docket Number EERE-2011-BT-TP-0042]
RIN 1904-AC53
Energy Conservation Program for Consumer Products and Certain
Commercial and Industrial Equipment: Test Procedures for Residential
and Commercial Water Heaters
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking and announcement of public
meeting.
-----------------------------------------------------------------------
SUMMARY: The U.S. Department of Energy (DOE) proposes to revise its
test procedure for residential water heaters and certain commercial
water heaters established under the Energy Policy and Conservation Act.
This rulemaking will fulfill DOE's statutory obligation for residential
and certain commercial water heaters to review its test procedure for
covered products and equipment at least once every seven years. In
addition, this rulemaking will satisfy DOE's statutory obligation to
develop a uniform efficiency descriptor for residential and commercial
water heaters. The proposed test method would apply the same efficiency
descriptor to all residential and certain commercial water heaters, and
it would extend coverage to eliminate certain gaps in the current
residential test procedure, update the simulated-use-test draw pattern,
and update the water delivery temperature requirement. DOE is also
announcing a public meeting to discuss and receive comments on issues
presented in this test procedure rulemaking.
DATES:
Comments: DOE will accept comments, data, and information regarding
this notice of proposed rulemaking (NOPR) before and after the public
meeting, but no later than January 21, 2014. See section V, ``Public
Participation,'' for details.
Meeting: DOE will hold a public meeting on December 6, 2013 from
9:00 a.m. to 4:00 p.m., in Washington, DC. The meeting will also be
broadcast as a webinar. See section V, ``Public Participation,'' for
webinar registration information, participant instructions, and
information about the capabilities available to webinar participants.
ADDRESSES: The public meeting will be held at the U.S. Department of
Energy, Forrestal Building, Room 8E-089, 1000 Independence Avenue SW.,
Washington, DC 20585. To attend, please notify Ms. Brenda Edwards at
(202) 586-2945. Please note that foreign nationals visiting DOE
Headquarters are subject to advance security screening procedures. Any
foreign national wishing to participate in the meeting should advise
DOE as soon as possible by contacting Ms. Edwards at the phone number
above to initiate the necessary procedures. Please also note that any
person wishing to bring a laptop computer into the Forrestal Building
will be required to obtain a property pass. Visitors should avoid
bringing laptops, or allow an extra 45 minutes. Persons may also attend
the public meeting via webinar. For more information, refer to section
V, ``Public Participation,'' near the end of this notice of proposed
rulemaking.
Interested persons are encouraged to submit comments using the
Federal eRulemaking Portal at www.regulations.gov. Follow the
instructions for submitting comments. Alternatively, interested persons
may submit comments, identified by docket number EERE-2011-BT-TP-0042
and/or RIN 1904-AC53, by any of the following methods:
Email: HeatingProducts-2011-TP-0042@ee.doe.gov. Include
EERE-2011-BT-TP-0042 and/or RIN 1904-AC53 in the subject line of the
message. Submit electronic comments in WordPerfect, Microsoft Word,
PDF, or ASCII file format, and avoid the use of special characters or
any form of encryption.
Postal Mail: Ms. Brenda Edwards, U.S. Department of
Energy, Building Technologies Office, Mailstop EE-2J, 1000 Independence
Avenue SW., Washington, DC 20585-0121. If possible, please submit all
items on a compact disc (CD), in which case it is not necessary to
include printed copies.
Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department
of Energy, Building Technologies Office, 950 L'Enfant Plaza SW., 6th
Floor, Washington, DC 20024. Telephone: (202) 586-2945. If possible,
please submit all items on a CD, in which case it is not necessary to
include printed copies.
Instructions: All submissions received must include the agency name
and docket number and/or RIN for this rulemaking. No telefacsimilies
(faxes) will be accepted. For detailed instructions on submitting
comments and additional information on the rulemaking process, see
section V of this document (Public Participation).
Docket: The docket is available for review at including Federal
Register notices, public meeting attendee lists and transcripts,
comments, and other supporting documents/materials. All documents in
the docket are listed in the index. However, not all documents listed
in the index may be publicly available, such as information that is
exempt from public disclosure.
A link to the docket Web page can be found at: https://www.regulations.gov/#!docketDetail;D=EERE-2011-BT-TP-0042. This Web
page contains a link to the docket for this notice of proposed
rulemaking on the site. The Web page contains simple instructions on
how to access all documents, including public comments, in the docket.
See section V, ``Public Participation,'' for information on how to
submit comments through www.regulations.gov.
For information on how to submit a comment, review other public
comments and the docket, or participate in the public meeting, contact
Ms. Brenda Edwards at (202) 586-2945 or by email:
Brenda.Edwards@ee.doe.gov.
FOR FURTHER INFORMATION CONTACT: Ms. Ashley Armstrong, U.S. Department
of Energy, Office of Energy Efficiency and Renewable Energy, Building
Technologies Office, EE-2J, 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-71, 1000 Independence Avenue SW., Washington, DC 20585-
0121. Telephone: (202) 586-9507. Email: Eric.Stas@hq.doe.gov.
For information on how to submit or review public comments, contact
Ms. Brenda Edwards, U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, Building Technologies Office, EE-2J,
1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone:
(202) 586-2945. Email: Brenda.Edwards@ee.doe.gov.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Authority and Background
II. Summary of the Notice of Proposed Rulemaking
III. Discussion
A. Scope
1. Coverage Range of Uniform Metric and Test Procedure
2. Storage Capacity Limits
3. Input Capacity Limits
4. Electric Instantaneous Water Heaters
B. Uniform Efficiency Descriptor
C. Draw Pattern
D. Instrumentation
E. Discrete Performance Tests
F. Test Conditions
1. Water Delivery Temperature
2. Ambient Temperature and Relative Humidity
3. Laboratory Airflow
[[Page 66203]]
G. Annual Energy Consumption Calculation
H. Conversion of Existing Energy Factor Ratings
I. Other Issues
J. Certification, Compliance, and Enforcement Issues
K. Reference Standards
L. Compliance With Other EPCA Requirements
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
V. Public Participation
A. Attendance at the Public Meeting
B. Procedure for Submitting Requests to Speak and Prepared
General Statements for Distribution
C. Conduct of the Public Meeting
D. Submission of Comments
E. 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 residential
water heaters, one subject of today's notice of proposed rulemaking.
(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 as Part A.
\2\ All references to EPCA in this document refer to the statute
as amended through the American Energy Manufacturing Technical
Corrections Act (AEMTCA), Public Law 112-210 (Dec. 18, 2012).
\3\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
Under EPCA, energy conservation programs generally consist of four
parts: (1) Testing; (2) labeling; (3) establishing Federal energy
conservation standards; and (4) certification and enforcement
procedures. The testing requirements consist of test procedures that
manufacturers of covered products and equipment must use as both the
basis for certifying to DOE that their products and equipment comply
with the applicable energy conservation standards adopted pursuant to
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 requirements to determine whether
the products comply with any relevant standards promulgated under EPCA.
(42 U.S.C. 6295(s))
Under 42 U.S.C. 6293, EPCA sets forth the criteria and procedures
that DOE must follow when prescribing or amending test procedures for
residential water heaters. EPCA provides, in relevant part, that any
test procedures prescribed or amended under this section must be
reasonably designed to produce test results which measure energy
efficiency, energy use, or estimated annual operating cost of a covered
product during a representative average use cycle or period of use, and
must not be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3)) In
addition, if DOE determines that a test procedure amendment is
warranted, it must publish proposed test procedures and offer the
public an opportunity to present oral and written comments on them. (42
U.S.C. 6293(b)(2))
For commercial water heaters, EPCA requires that if the test
procedure referenced in the American Society of Heating, Refrigerating,
and Air-Conditioning Engineers (ASHRAE) Standard 90.1 is updated, DOE
must update its test procedure to be consistent with the amended test
procedure in ASHRAE Standard 90.1, ``Energy Standard for Buildings
Except Low-Rise Residential Buildings,'' unless DOE determines by rule
published in the Federal Register and supported by clear and convincing
evidence, that the amended test procedure is not reasonably designed to
produce test results which reflect the energy efficiency, energy use,
or estimated operating costs of that type of ASHRAE equipment during a
representative average use cycle. In addition, DOE must determine that
the amended test procedure is not unduly burdensome to conduct. (42
U.S.C. 6314(a)(2) and (4))
In any rulemaking to amend a test procedure, DOE must determine the
extent to which the proposed test procedure would alter the product's
measured energy efficiency. (42 U.S.C. 6293(e)(1)) If DOE determines
that the amended test procedure would alter the measured efficiency of
a covered product, DOE must amend the applicable energy conservation
standard accordingly. (42 U.S.C. 6293(e)(2))
Further, the Energy Independence and Security Act of 2007 (EISA
2007) amended EPCA to require that at least once every 7 years, DOE
must review test procedures for all covered products and either amend
test procedures (if the Secretary determines that amended test
procedures would more accurately or fully comply with the requirements
of 42 U.S.C. 6293(b)(3) for residential products or 42 U.S.C.
6314(a)(2)-(3) for commercial equipment) or publish notice in the
Federal Register of any determination not to amend a test procedure.
(42 U.S.C. 6293(b)(1)(A); 42 U.S.C. 6314(a)(1)(A)) Under this
requirement, DOE must review the test procedures for residential water
heaters not later than December 19, 2014 (i.e., 7 years after the
enactment of EISA 2007), and DOE must review the test procedures for
commercial water heaters not later than May 16, 2019 (i.e., 7 years
after the last final rule for commercial water heater test procedures
\4\). Thus, the final rule resulting from this rulemaking will satisfy
the requirement to review the test procedures for residential and
certain commercial water heaters every seven years.
---------------------------------------------------------------------------
\4\ On May 16, 2012, DOE published a final rule in the Federal
Register amending the test procedures for commercial water heaters.
77 FR 28928.
---------------------------------------------------------------------------
DOE's test procedure for residential water heaters is found in the
Code of Federal Regulations (CFR) at 10 CFR 430.23(e) and 10 CFR part
430, subpart B, appendix E. The test procedure includes provisions for
determining the energy efficiency (energy factor (EF)), as well as the
annual energy consumption of these products. DOE's test procedure for
commercial water heaters is found at 10 CFR 431.106; that test
procedure incorporates by reference American National Standards
Institute (ANSI) Z21.10.3, Gas Water Heaters--Volume III, Storage Water
Heaters With Input Ratings Above 75,000 Btu Per Hour, Circulating and
Instantaneous, and provides a method for determining the thermal
efficiency and standby loss of this equipment.
In addition to the test procedure review provision discussed above,
EISA 2007 also amended EPCA to require DOE to amend its test procedures
for all covered residential products to include measurement of standby
mode and off mode energy consumption. (42 U.S.C. 6295(gg)(2)(A))
Consequently, DOE recently completed a rulemaking to
[[Page 66204]]
consider amending its test procedure for residential water heaters to
include provisions for measuring the standby mode and off mode energy
consumption of those products. Pursuant to the requirements of EPCA,
DOE published a notice of proposed rulemaking (NOPR) in the Federal
Register on August 30, 2010, for three different residential heating
products (water heaters, pool heaters, and direct heating equipment)
related to standby mode and off mode energy consumption, but the NOPR
proposed no amendments to the DOE test procedure for residential water
heaters because DOE tentatively concluded that standby mode and off
mode energy consumption was already accounted for in the existing DOE
test method.\5\ 75 FR 52892, 52895. Subsequently, DOE published a final
rule in the Federal Register on December 17, 2012, which affirmed its
conclusion that no changes were needed to the existing test procedure
for residential water heaters. 77 FR 74559, 74561-74562. However, that
rulemaking was limited to consideration of test procedure amendments to
address the above-referenced standby mode and off mode requirements; it
did not address several other potential issues in DOE's existing test
procedure for residential water heaters. DOE addresses these issues in
today's NOPR.
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\5\ For more information, please visit DOE's Web site at: https://www1.eere.energy.gov/buildings/appliance_-standards/residential/
waterheaters.html.
---------------------------------------------------------------------------
On October 12, 2011, DOE published in the Federal Register a
request for information (RFI) that identified and requested comment on
a number of issues regarding the test procedures for residential water
heaters. 76 FR 63211. DOE accepted comments and information on the RFI
until November 28, 2011, and considered all feedback received when
developing the proposals contained in this notice. Each of the issues
raised in the RFI is discussed in detail in section III, along with
comments received on the issues and DOE's responses. In addition,
several topics not addressed in the RFI but brought up by interested
parties in their comments are discussed in section III of this NOPR.
On December 18, 2012, the American Energy Manufacturing Technical
Corrections Act (AEMTCA), Public Law 112-210, was signed into law. In
relevant part, it amended EPCA to require that DOE publish a final rule
establishing a uniform efficiency descriptor and accompanying test
methods for covered residential water heaters and commercial water
heating equipment within one year of the enactment of AEMTCA. (42
U.S.C. 6295(e)(5)(B)) The final rule must replace the current energy
factor, thermal efficiency, and standby loss metrics with a uniform
efficiency descriptor. (42 U.S.C. 6295(e)(5)(C)) AEMTCA requires that,
beginning one year after the date of publication of DOE's final rule
establishing the uniform descriptor, the efficiency standards for
covered water heaters must be denominated according to the uniform
efficiency descriptor established in the final rule (42 U.S.C.
6295(e)(5)(D)), and that DOE must develop a mathematical conversion
factor for converting the measurement of efficiency for covered water
heaters from the test procedures and metrics currently in effect to the
new uniform energy descriptor. (42 U.S.C. 6295(e)(5)(E)(i)-(ii)) After
the effective date of the final rule, covered water heaters shall be
considered to comply with the final rule and with any revised labeling
requirements established by the Federal Trade Commission (FTC) to carry
out the final rule, if the covered water heater was manufactured prior
to the effective date of the final rule and complies with the
efficiency standards and labeling requirements in effect prior to the
final rule. (42 U.S.C. 6295(e)(5)(K))
AEMTCA also requires that the uniform efficiency descriptor and
accompanying test method apply, to the maximum extent practicable, to
all water-heating technologies currently in use and to future water-
heating technologies. (42 U.S.C. 6295(e)(5)(H)) AEMTCA allows DOE to
provide an exclusion from the uniform efficiency descriptor for
specific categories of otherwise covered water heaters that do not have
residential uses, that can be clearly described, and that are
effectively rated using the current thermal efficiency and standby loss
descriptors. (42 U.S.C. 6295(e)(5)(F))
AEMTCA outlines DOE's various options for establishing a new
uniform efficiency descriptor for water heaters. The options that
AEMTCA provides to DOE include: (1) A revised version of the energy
factor descriptor currently in use; (2) the thermal efficiency and
standby loss descriptors currently in use; (3) a revised version of the
thermal efficiency and standby loss descriptors; (4) a hybrid of
descriptors; or (5) a new approach. (42 U.S.C. 6295(e)(5)(G)) Lastly,
AEMTCA requires that DOE invite stakeholders to participate in the
rulemaking process, and that DOE contract with the National Institute
of Standards and Technology (NIST), as necessary, to conduct testing
and simulation of alternative descriptors identified for consideration.
(42 U.S.C. 6295(e)(5)(I)-(J))
DOE published an RFI on January 11, 2013 requesting input on the
various issues pertaining to water heaters discussed in AEMTCA. 78 FR
2340. The feedback received from stakeholders was taken into
consideration and is discussed further in section III of this NOPR.
II. Summary of the Notice of Proposed Rulemaking
In this NOPR, DOE proposes to modify the current test procedures
for residential water heaters and certain commercial water heaters. The
proposed amendments would modify the test procedure to be more
representative of conditions encountered in the field (including
modifications to both the test conditions and the draw patterns) and
expand the scope of the test procedure to apply to certain commercial
water heaters and certain residential water heaters that are currently
not covered by the test procedure. The following paragraphs summarize
these proposed changes.
DOE proposes to modify the test procedure for water heaters to
establish a uniform descriptor that can be applied to: (1) All
residential water heaters (including certain residential water heaters
that are covered products under EPCA's definition of ``water heater''
at 42 U.S.C. 6291(27), but that are not covered under the existing test
method); and (2) to certain commercial water heaters that have
residential applications. This includes the proposed establishment of
test procedure provisions that are applicable to water heaters with
storage volumes between 2 gallons (7.6 L) and 20 gallons (76 L), and
the proposed creation of a definition for ``electric instantaneous
water heater.'' In addition, DOE proposes to establish a new equipment
class of commercial water heaters and corresponding definition for
``light commercial water heater.'' DOE proposes to require water
heaters that would be classified as ``light commercial'' to be tested
using the test procedure for the uniform efficiency descriptor being
proposed in this NOPR.
DOE is also proposing the use of multiple draw patterns for testing
water heaters, with certain draw patterns prescribed as a function of
equipment capacity. Further, DOE proposes updates to the water heater
draw pattern to be more reflective of actual field usage based on
recent field test data. Lastly, DOE is modifying the water delivery
temperature requirement to better reflect conditions as seen in typical
installations in the field.
[[Page 66205]]
III. Discussion
In response to the October 2011 RFI, DOE received 19 written
comments related to water heaters from the following interested
parties: Pacific Gas and Electric Company (PGE), Applied Energy
Technology (AET), Davis Energy Group, American Council for an Energy-
Efficient Economy (ACEEE), Southern California Edison (SCE), National
Renewable Energy Laboratory (NREL), Natural Resources Canada (NRCan),
Natural Resources Defense Council (NRDC), Air-Conditioning, Heating,
and Refrigeration Institute (AHRI), Northwest Energy Efficiency
Alliance (NEEA), American Gas Association (AGA), National Propane Gas
Association (NPGA), A.O. Smith Corporation (AO Smith), Bradford White
Corporation (Bradford White), Lochinvar, Stone Mountain Technologies,
Bosch Thermotechnology Corp. (Bosch), General Electric Company (GE),
and ASHRAE.
In response to the January 2013 RFI, DOE received 18 written
comments from the following interested parties: NREL, Bradford White,
AGA, NPGA, AHRI, AO Smith, joint efficiency advocates (joint
comment),\6\ GE, NEEA, Rheem Manufacturing Company (Rheem), American
Public Gas Association (APGA), Edison Electric Institute (EEI), Heat
Transfer Products Inc. (HTP), Natural Resources Canada (NRCan), Seisco
International Limited (Seisco), Aquarensics, and two separate comments
from the University of Houston--Clear Lake (UHCL1, UHCL2).
---------------------------------------------------------------------------
\6\ ACEEE submitted a joint comment on behalf of ACEEE, the
Appliance Standards Awareness Project (ASAP), the National Consumer
Law Center (NCLC), the Natural Resources Defense Council (NRDC), the
Northeast Energy Efficiency Partnerships (NEEP), and the Northwest
Power and Conservation Council (NPCC).
---------------------------------------------------------------------------
These interested parties commented on a range of issues, including
those identified by DOE in the October 2011 RFI and the January 2013
RFI, as well as several other pertinent issues. The issues on which DOE
received comment, as well as DOE's response to those comments and the
resulting proposed changes to the test procedures for water heaters,
are discussed in the subsections immediately below.
A. Scope
DOE's test procedures for residential water heaters codified at 10
CFR 430.23(e) and 10 CFR part 430, subpart B, appendix E address gas-
fired, electric, and oil-fired storage-type (i.e., storage volume not
less than 20 gallons (76 L)) and gas-fired and electric instantaneous-
type (i.e., storage volume less than 2 gallons (7.6 L)) water heaters.
However, the DOE test procedure does not define ``electric
instantaneous water heater.'' In addition, it does not address the
following types of products: (1) Gas-fired water heaters that have a
storage volume at or above 2 gallons and less than 20 gallons (76 L);
(2) electric storage water heaters with storage volume less than 20
gallons (76 L); and (3) storage water heaters with very large storage
capacities, including oil-fired water heaters with storage volumes
greater than 50 gallons (190 L), gas-fired water heaters with storage
volumes above 100 gallons (380 L), and electric water heaters with
storage volumes above 120 gallons (450 L). As discussed in the
following sections, DOE proposes to expand the scope of coverage of its
test method so that it is applicable to all products that meet the
definition of residential water heater, including those products listed
above which are currently not addressed by the existing DOE test
method. DOE is also revising 10 CFR 430.32(d) to clarify the
applicability of the existing standards with respect to the expanded
test procedure scope.
DOE's test procedures for commercial water heaters are found at 10
CFR 431.106. In terms of capacity, the procedures for commercial water
heaters cover storage water heaters with an input rating up to 4,000
British thermal units (Btu) per hour (Btu/h) per gallon of stored
water, instantaneous water heaters with input ratings not less than
4,000 Btu/h per gallon of stored water, and hot water supply boilers
with input ratings from 300,000 Btu/h to 12,500,000 Btu/h and of at
least 4,000 Btu/h per gallon of stored water. Units using natural gas,
oil, or electricity are covered by these test methods.
EPCA includes definitions for both residential and commercial water
heaters that set the scope of DOE's authority for these products. (42
U.S.C. 6291(27); 42 U.S.C. 6311(12)) As required by AEMTCA, DOE
proposes to create a uniform metric and test method for all covered
water heaters,\7\ regardless of whether a particular water heater falls
under the scope of residential water heaters or commercial water
heaters as defined in EPCA. In doing so, DOE also proposes to expand
the scope of the test procedure to include definitions and test methods
for the types of products noted above that are not covered by DOE's
residential test procedure. DOE identified these topics as issues for
comment in the October 2011 RFI and the January 2013 RFI. 76 FR 63211,
63212-63213 (Oct. 12, 2011); 78 FR 2340, 2344-2346 (Jan. 11, 2013).
---------------------------------------------------------------------------
\7\ As provided by 42 U.S.C. 6295(e)(5)(F), DOE is proposing to
allow for the exclusion from the uniform efficiency descriptor of
certain commercial water heaters that do not have a residential use
and can be clearly described in the final rule and are effectively
rated using the thermal efficiency and standby loss descriptors. The
water heaters that DOE is proposing to exclude are discussed further
in section III.A.1.
---------------------------------------------------------------------------
1. Coverage Range of Uniform Metric and Test Procedure
In the January 2013 RFI, DOE requested comment on whether the
uniform efficiency descriptor required by AEMTCA should apply to all
types of residential and commercial water heaters covered by EPCA, in
addition to hot water supply boilers and unfired hot water storage
tanks. In requesting comment, DOE acknowledged that AEMTCA provides for
the possibility of an exclusion for certain water heaters from the
uniform efficiency metric and accompanying test method. 78 FR 2340,
2345-46 (Jan. 11, 2013).
DOE received 7 comments that opposed DOE's tentative interpretation
that AEMTCA requires the uniform descriptor to apply to all types of
residential and commercial water heaters and indicated that DOE should
utilize the statutory provision permitting an exclusion for any
specific category of otherwise covered water heaters that do not have a
residential use. (Bradford White, No. 30 at p. 2; AHRI, No. 33 at p. 1;
AO Smith, No. 34 at p. 1; Joint comment, No. 35 at p. 2; NEEA, No. 37
at p. 2; Rheem, No. 38 at p. 2; HTP, No. 41 at p. 1) \8\ Bradford White
recommended that the uniform efficiency descriptor be limited to water
heaters with inputs less than 200,000 Btu/h, which would cover those
water heaters intended for residential applications. (Bradford White,
No. 30 at p. 2) AHRI, AO Smith, Rheem, and HTP indicated that the
legislation was intended to apply to residential products only and that
development of a uniform metric and test method for all water heaters
is not realistic given the substantially different duty cycles between
water heaters meant for commercial applications and those meant for
residential applications. (AHRI, No. 33 at pp. 1-2; AO Smith, No. 34 at
p. 1; Rheem, No. 38 at p. 2; HTP, No. 41 at p. 1) The joint commenters
supported a realignment of the scope that includes all water heaters
except those clearly designed to deliver large amounts of hot water.
(Joint comment, No. 35 at p. 2) NEEA recommended that DOE should focus
on water heaters
[[Page 66206]]
meant for residential and small commercial applications. (NEEA, No. 37
at p. 2) No commenters supported DOE's tentative interpretation that
AEMTCA requires the uniform descriptor to apply to all types of
residential and commercial water heaters.
---------------------------------------------------------------------------
\8\ All references to comments received in response to the
October 2011 and January 2013 RFI's identify the commenter, the
identification number applied by DOE, and the page of the comment
package on which the particular point has been discussed.
---------------------------------------------------------------------------
After considering the comments received, DOE proposes to exclude
from the uniform efficiency descriptor any specific category of water
heater that does not have a residential use. As noted above, AEMTCA
provides that DOE can exclude from the uniform descriptor any specific
categories of covered water heaters that do not have a residential use,
can be clearly described in the final rule, and are effectively rated
using the current thermal efficiency and standby loss descriptors. (42
U.S.C. 6295(e)(5)(F)) DOE received 13 comments regarding how to define
water heaters that do not have a residential application. In light of
these comments, DOE proposes to define a new classification of
commercial water heaters for which the uniform efficiency descriptor
would apply (i.e., ``light commercial water heaters''), which DOE
believes can be clearly distinguished from the commercial water heaters
for which the uniform descriptor would not apply under this proposal.
DOE believes that the current metrics for commercial water heaters that
are used only in commercial settings are appropriate and adequate to
characterize the performance of such commercial water heaters.
Commercial water heaters typically cycle less than residential water
heaters due to longer run-times followed by standby periods.
(Residential water heaters are typically subject to a number of small
draws and short on-times throughout the day.) As a result, cycling
losses of water heaters used in commercial applications are generally
not as significant as those used in residential applications. Thus, DOE
believes that thermal efficiency and standby loss metrics adequately
characterize the efficiency in active and standby modes, respectively.
AHRI, AO Smith, and HTP suggested that the following
characteristics may be suitable to distinguish water heaters intended
for non-residential use: (1) Designed to deliver water at a
thermostatically controlled temperature of 180[emsp14][deg]F or more;
(2) bear a Code Symbol Stamp signifying compliance with the
requirements of the American Society of Mechanical Engineers (ASME)
Boiler and Pressure Vessel Code; and (3) require electricity as the
primary energy source and require the use of 3-phase external supply.
(AHRI, No. 33 at p. 2; AO Smith, No. 34 at p. 1; HTP, No. 41 at p. 2)
The joint commenters likewise stated that water heaters utilizing 3-
phase electric power, designed to deliver water above
180[emsp14][deg]F, and falling under the guise of the ASME pressure
vessel code are not typical of residential applications. (Joint
comment, No. 35 at p. 2) NEEA commented that there are many water
heaters with features that make them unsuitable for residential and
small commercial applications and provided examples of units with set
points of 180[emsp14][deg]F or higher, 3-phase power, and large input
ratings and volumes. (NEEA, No. 37 at p. 2) AHRI, AO Smith, Rheem, and
HTP also provided tables of rated inputs and storage volumes to
distinguish water heaters that are not intended for residential
applications. (AHRI, No. 33 at p. 2; AO Smith, No. 34 at p. 1; Rheem,
No. 38 at p. 2; HTP, No. 41 at p. 2) Those limits are grouped by water
heater type and are shown in Table III.1.
Table III.1--Suggested Capacity Limitations for Defining Non-Residential
Water Heaters
------------------------------------------------------------------------
Indicator of non-residential application
Water heater type by commenter
------------------------------------------------------------------------
Gas-fired storage............ AHRI, Rheem: Rated input >100 kBtu/h;
Rated storage volume <20 gallons and
>100 gallons.
AO Smith: Rated Input > 100kBtu/h; Rated
storage volume >100 gallons.
HTP: Rated input >150 kBtu/h; Rated
storage volume <20 gallons and >120
gallons.
Oil-fired storage............ AHRI, AO Smith, Rheem: Rated input >140
kBtu/h; Rated storage volume >50
gallons.
Electric storage............. AHRI, Rheem, HTP: Rated input >12 kW;
Rated storage volume <20 gallons and
>120 gallons.
AO Smith: Rated Input >12 kW; Rated
storage volume >120 gallons.
Heat Pump with Storage....... AHRI, AO Smith, Rheem, HTP: Rated current
>24 Amperes; Rated voltage >250 V; Rated
storage volume >120 gallons.
Gas-fired instantaneous...... AHRI, AO Smith, Rheem, HTP: Rated input
>200 kBtu/h; Water volume >1 gallon per
4000 Btu/h of input.
Electric instantaneous....... AHRI, Rheem: Rated input >12 kW; Water
volume >2 gallons.
AO Smith: Rated input >25 kW; Water
volume >2 gallons.
Oil-fired instantaneous...... AHRI, Rheem, AO Smith: Rated input >210
kBtu/h; Water volume >2 gallons.
------------------------------------------------------------------------
Bradford White recommended that the new descriptor be limited to
water heaters with inputs less than 200,000 Btu/h because, according to
the commenter, water heaters with inputs greater than or equal to
200,000 Btu/hr are not used in residential applications since such a
high input is not required in these types of applications. (Bradford
White, No. 30 at p. 2) AGA stated that efficiency descriptors and test
methods are best developed through consensus-based processes and
referred DOE to the scope that is currently present in ASHRAE Standard
118.2, Method of Testing for Rating Residential Water Heaters. (AGA,
No. 31 at 2)
Upon considering these comments, DOE agrees with commenters that a
unit requiring three-phase electricity would nearly always be used only
in a commercial setting, as residential homes are wired almost
exclusively for single-phase power. Likewise, DOE agrees with
commenters that units with an ASME pressure vessel rating or units
capable of delivering water at temperatures at or exceeding
180[emsp14][deg]F would generally only be used in commercial settings.
As a result, DOE proposes to use these three criteria as the basis for
defining ``light commercial'' water heaters that have residential
applications.
DOE also considered the input and storage capacity criteria
proposed by stakeholders to differentiate commercial water heaters that
would only be used in non-residential applications from commercial
water heaters that could have residential applications. DOE notes that
equipment that was once classified as residential based on input
capacity or storage volume might now be installed in a commercial
setting and vice versa. Given that such changes occur over time as new
technologies develop, DOE is declining to propose criteria in this NOPR
on an input capacity basis. Instead, DOE believes that the three
criteria discussed in the preceding
[[Page 66207]]
paragraph are adequate to define the class of commercial water heaters
that could have residential applications.
Consequently, DOE proposes to add the following definition of
``light commercial water heater'' to 10 CFR 431.102:
Light commercial water heater means any gas-fired, electric, or oil
storage or instantaneous commercial water heater that meets the
following conditions:
(1) For models requiring electricity, uses single-phase external
power supply;
(2) Is not capable of delivering hot water at temperatures of
180[emsp14][deg]F or above; and
(3) Does not bear a Code Symbol Stamp signifying compliance with
the requirements of the ASME Boiler and Pressure Vessel Code.
Although light commercial water heaters could have residential
applications, DOE notes that the new ``light commercial water heater''
definition represents a type of water heater that, to a significant
extent, is distributed in commerce for industrial or commercial use.
These water heaters were and continue to be covered industrial
equipment, and, if these proposals are finalized, will continue to be
subject to the regulations in part 431 and the certification
requirements for commercial and industrial equipment in part 429.
Similarly, although DOE recognizes that some consumer water heaters may
be installed in a commercial setting, those waters heaters are covered
consumer products for the purposes of DOE regulations, the regulations
in part 430 continue to apply, and they must be certified as consumer
products under part 429.
If a commercial water heater does not meet all of these three
conditions, it would be classified as a commercial water heater that
would not be expected to be used in residential applications and would
be subject to the current test methods prescribed in 10 CFR 431.106,
which reference ANSI Z21.10.3. If a commercial water heater meets all
three criteria, DOE proposes to consider it a ``light commercial water
heater,'' which would be subject to the uniform efficiency descriptor
and test method proposed in today's NOPR. Accordingly, DOE proposes to
add a row to Table 1 of 10 CFR 431.106 specifying 10 CFR part 430,
subpart B, Appendix E as the test method for this class of equipment.
DOE seeks comment on both the proposed definition of ``light commercial
water heater'' and the proposal to subject this equipment to the test
methods at Appendix E. This is identified as issue 1 in section V.E,
``Issues on Which DOE Seeks Comment.''
DOE also received comments recommending that certain types of water
heaters should be excluded from the uniform descriptor for various
reasons. NREL commented that storage tanks do not make a complete water
heating system, so an energy factor is not appropriate. NREL elaborated
that a rating using a standby loss coefficient could be appropriate.
(NREL, No. 29 at pp. 3-4) AHRI, AO Smith, and HTP recommended that DOE
exclude from the descriptor: (1) Unfired storage tanks because they do
not actually heat water; (2) add-on heat pumps because DOE has
previously determined that these are not covered products and they are
not complete water heaters; and (3) hot water supply boilers because,
by definition, they have inputs exceeding the values listed in the
commenters' recommendations and because these products are all subject
to the requirements of the ASME Boiler and Pressure Vessel Code (AHRI,
No. 33 at pp. 4-5; AO Smith, No. 34 at p. 3; HTP, No. 41 at p. 5) Rheem
expressed support for AHRI's list of exclusions. (Rheem, No. 38 at p.
2) NEEA recommended that DOE should exclude water storage tanks from
the uniform descriptor because they are technically not water heaters
and they simply store water heated elsewhere. NEEA also commented that
unfired storage tanks should not be excused from all efficiency
requirements since standby loss efficiency is important for all hot
water storage vessels, regardless of where and how the water is heated.
(NEEA, No. 37 at p. 2) Conversely, the joint commenters recommended
that the uniform efficiency descriptor should be able to effectively
measure the efficiency of electric heat pump water heaters without an
integrated storage tank in the event it is included in future Federal
coverage. (Joint comment, No. 35 at p. 5)
DOE has tentatively determined that certain commercial equipment
such as unfired storage tanks and add-on heat pump water heaters are
not appropriately rated using the uniform descriptor applicable to
other water heaters. Unfired storage tanks are not complete water-
heating systems and require additional equipment in the field to
operate. Thus, DOE believes that other metrics may be more appropriate
for these devices with limited functionality compared to actual water
heaters, and that their performance as part of a complete water-heating
system is so dependent upon other components of the system that use of
the uniform descriptor may be unrepresentative of its performance as a
system. For add-on heat pump water heaters, DOE agrees with
stakeholders that DOE has previously determined that these are not
covered residential products. As such, DOE only has authority to cover
commercial add-on heat pumps; however, this equipment does not have
residential applications, and, therefore, is not suitable for inclusion
in the uniform efficiency descriptor. DOE has also tentatively
determined that hot water supply boilers are more appropriately rated
using the existing metrics for commercial water heaters, as this
equipment has very high input ratings and are subject to the ASME
Boiler and Pressure Vessel Code, and their use is similar to that of
other commercial water heaters in commercial applications. DOE will
address the types of water-heating equipment that are excluded from the
uniform descriptor (e.g., unfired storage tanks, add-on heat pump water
heaters, and hot water supply boilers) in a subsequent test procedure
rulemaking.
2. Storage Capacity Limits
Under the existing regulatory definitions, DOE's current
residential water heater test procedures are not applicable to gas or
electric water heaters with storage tanks that are at or above 2
gallons (7.6 L) and less than 20 gallons (76 L). In terms of the high
end of the capacity range, the current DOE test procedure for
residential water heaters only applies to gas-fired water heaters with
storage volumes less than or equal to 100 gallons (380 L), electric
resistance and heat pump storage water heaters with storage volumes
less than or equal to 120 gallons (450 L), and oil-fired water heaters
with storage volumes less than or equal to 50 gallons (190 L). 10 CFR
part 430, subpart B, appendix E, sections 1.12.1, 1.12.2, and 1.12.4.
In the 1998 rulemaking establishing test procedures for residential
water heaters, DOE proposed to include units with storage volumes
between 2 and 20 gallons, but commenters raised concerns that the test
procedure demand of 64.3 gallons per day was not appropriate for these
small units. 63 FR 25996, 26000 (May 11, 1998). At that time, DOE
concluded that the data to determine the appropriate daily hot water
consumption did not exist and that alternative procedures proposed by
commenters were not fully evaluated. For these reasons, the Department
tabled consideration of the inclusion of these water heaters until a
future revision of the DOE test procedure. In recent years, however,
water heaters with such capacities have begun to populate the market.
The definitions in
[[Page 66208]]
the DOE test procedure (cited above) specify that instantaneous-type
water heaters have a storage volume of less than two gallons (7.6 L)
and that electric or gas storage-type water heaters have a storage
volume of 20 gallons (76 L) or more. The storage capacity of oil water
heaters in the test method is not restricted by a lower limit, with the
specification stating that an oil-fired storage water heater simply has
a rated capacity less than or equal to 50 gallons (190 L). 10 CFR part
430, subpart B, appendix E, sections 1.7 and 1.12. The definition for
``Storage-type Water Heater of More than 2 Gallons (7.6 Liters) and
Less than 20 Gallons (76 Liters)'' is currently reserved. Id. at
section 1.12.5. DOE requested comment on the potential to address this
gap in the October 2011 RFI, and received several comments from
interested parties. 76 FR 63211, 63213 (Oct. 12, 2011).
DOE received 11 comments in support of the inclusion of water
heaters with storage volumes between 2 and 20 gallons. (Bradford White,
No. 2 at p. 1; PGE, No. 3 at p. 1; SCE, No. 4 at p. 1; Stone Mountain
Technologies, No. 5 at p. 2; AO Smith, No. 8 at p. 1; NEEA, No. 9 at p.
2; AHRI, No. 12 at p. 1; NREL, No. 14 at p. 7; NRDC, No. 20 at p. 1;
AET, No. 22 at p. 7; ACEEE, No. 24 at pp. 3-4). No comments were
received opposed to this measure.
AHRI, AO Smith, Bradford White, and Lochinvar suggested that a
distinct test procedure is needed for electric storage water heaters
with volumes between 2 and 20 gallons since the current test method is
not suited for such point-of-use products and that this test method
measure only the standby loss of the unit. (Bradford White, No. 2 at p.
1; AO Smith, No. 8 at p.1; Lochinvar, No. 10 at p. 1; AHRI, No. 12 at
p. 2) Stone Mountain Technologies stated further that all electric
resistance water heaters should be subjected to only a standby loss
test, because differences between models is almost solely based on
standby losses. (Stone Mountain Technologies, No. 5 at p. 3) DOE has
considered these points but has tentatively concluded that, for equity
across water-heating technologies, all water heaters should be tested
under a simulated-use profile as will be discussed in section III.C.
DOE proposes a profile that is appropriate for point-of-use water
heaters, so any concerns that the current test method is not suitable
are addressed by the proposed test method. This profile will simulate
the way that a point-of-use water heater is used in the field and will
capture any operational characteristics that could affect its
efficiency. DOE also believes that a simulated-use test will better
capture any potential cycling losses or inefficiencies in meeting the
demands imposed on all water heaters.
After considering the comments received, DOE proposes to expand the
scope of the water heater test procedure for the uniform efficiency
descriptor to include water heaters with storage volumes between 2 and
20 gallons. The proposed modifications will specify the method of test
set-up (including instrumenting such water heaters), a test method to
assess the delivery capacity, and the draw pattern that would be used
to determine the energy efficiency of such units. The proposed
amendments for water heaters with storage volumes between 2 and 20
gallons are discussed in detail in section III.C of today's notice of
proposed rulemaking.
DOE is not aware of any residential water heaters available on the
market with storage volumes above 100 gallons, 120 gallons, and 50
gallons for gas-fired, electric (resistance and heat pump), and oil-
fired water heaters, respectively, that would be covered as residential
products under EPCA. Due to the lack of water heaters with very large
storage volumes that meet the definition of a residential ``water
heater,'' DOE tentatively concluded in the October 2011 RFI that it is
unnecessary to expand the scope of the test procedure to include gas-
fired products over 100 gallons, electric products over 120 gallons, or
oil-fired products over 50 gallons, and requested comment on this
tentative conclusion. 76 FR 63211, 63213 (Oct. 12, 2011).
Four commenters (Bradford White, AO Smith, NEEA, AHRI) supported
DOE's position to maintain the existing capacity limits for storage
water heaters, while three commenters (Stone Mountain Technologies,
NREL, AET) recommended that the test method be expanded to include all
water heaters with storage volumes from 0 to 120 gallons. (Bradford
White, No. 2 at p. 1; AO Smith, No. 8 at p. 1; NEEA, No. 9 at p. 2;
AHRI, No. 12 at p. 1; Stone Mountain Technologies, No. 5 at p. 2; NREL,
No. 14 at p. 8; AET, No. 22 at pp. 6-7) AET noted that the pressure
vessel code from the American Society of Mechanical Engineers requires
that vessels intended to store fluids under pressure must individually
undergo a rigorous test and inspection procedure if they have volumes
greater than 120 gallons. AET noted that because these test and
certification procedures are expensive, manufacturers will avoid making
products intended for residential use that require an ASME inspection
and code stamp. For this reason, AET commented that the upper limit of
120 gallons would be appropriate for all residential water heaters. AET
further suggests that expanding the volume limit to 120 gallons would
prevent manufacturers from evading efficiency standards by marketing
water heaters slightly larger than the currently specified limits.
(AET, No. 22 at pp. 6-7)
The subsequent passage of AEMTCA has necessitated that DOE
reconsider the scope of all water heater test procedures. DOE has
considered these comments, as well as the provisions of AEMTCA, and
proposes to expand the scope of the test procedure to include all
covered water heaters that could have residential applications and
remove the limitations on maximum storage volume that are currently in
the residential test procedure for gas-fired, electric, and oil storage
water heaters. The Department's authority to regulate water heaters is
limited to those explicitly defined as covered products by EPCA. EPCA
defines the term ``water heater'' as a product which utilizes oil, gas,
or electricity to heat potable water for use outside the heater upon
demand. (42 U.S.C. 6291(27)) Further, EPCA defines storage type units
which include gas storage water heaters with an input of 75,000 Btu per
hour or less, oil storage water heaters with an input of 105,000 Btu
per hour or less, and electric storage water heaters with an input of
12 kilowatts or less. EPCA also defines instantaneous type units, which
are water heaters that contain no more than one gallon of water per
4,000 Btu per hour of input, including gas instantaneous water heaters
with an input of 200,000 Btu per hour or less, oil instantaneous water
heaters with an input of 210,000 Btu per hour or less, and electric
instantaneous water heaters with an input of 12 kilowatts or less.
Lastly, EPCA defines covered heat pump type units, which have a maximum
current rating of 24 amperes at a voltage no greater than 250 volts,
and which are designed to transfer thermal energy from one temperature
level to a higher temperature level for the purpose of heating water,
and include all ancillary equipment such as fans, storage tanks, pumps,
or controls necessary for the device to perform its function. Id.
For commercial water heating equipment, EPCA defines ``storage
water heater'' as a water heater that heats and stores water within the
appliance at a thermostatically controlled temperature for delivery on
demand, and does not include units with an input rating of 4000 Btu per
hour or more per gallon of stored water. EPCA also defines
``instantaneous water heater'' as a water
[[Page 66209]]
heater that has an input rating of at least 4000 Btu per hour per
gallon of stored water. Lastly, EPCA defines the term ``unfired hot
water storage tank'' as a tank used to store water that is heated
externally. (42 U.S.C. 6311(12))
AEMTCA requires that the new metric apply to the extent possible to
all water-heating technologies used in residential applications. (42
U.S.C. 6295(e)(5)(F) and (H)) DOE believes that the test method
proposed in today's NOPR adequately addresses large water heaters
regardless of storage volume, provided that they are used in
residential applications. As noted previously in section III.A.1, DOE
proposes to exclude units used only in non-residential applications,
but DOE does not believe that storage volume alone would dictate
whether a unit is residential or commercial. As noted by AET, the ASME
pressure vessel code requires that vessels intended to store fluids
under pressure must undergo a rigorous test and inspection procedure if
they have volumes greater than 120 gallons. Any such products would be
ASME pressure vessel rated, and under the definition of ``light
commercial water heater'' proposed in section III.A.1, would not be
subject to the uniform efficiency descriptor, which would effectively
limit the maximum storage volume to 120 gallons for the purposes of
using the uniform descriptor. For these reasons, DOE proposes to
eliminate the maximum storage volume limitations from the residential
water heater test procedure.
3. Input Capacity Limits
DOE's current residential water heater test procedure is not
applicable to gas-fired instantaneous water heaters with input
capacities at or below 50,000 Btu/h or at or above 200,000 Btu/h. 10
CFR Part 430, subpart B, Appendix E, section 1.7.2. In addition, the
test procedure is not applicable to gas-fired storage water heaters
with input capacities above 75,000 Btu/h, electric storage water
heaters with input ratings above 12 kW, and oil-fired storage water
heaters with input ratings above 105,000 Btu/h. 10 CFR Part 430,
subpart B, Appnedix E, section 1.12.
DOE proposes to eliminate the minimum limit on the firing rate of
instantaneous gas water heaters of 50,000 Btu/h, as AEMTCA requires
that the new metric apply to the maximum extent practical to all water-
heating technologies intended for residential application. (42 U.S.C.
6295(e)(5)(F) and (H)) As discussed in section III.C, DOE proposes to
adopt multiple draw patterns that would vary based on the delivery
capacity of the water heater. Because the draw pattern would be
dependent upon delivery capacity, DOE believes that small gas-fired
instantaneous units could be appropriately tested under the proposed
procedure. Thus, DOE believes there is no reason to retain this lower
limit on gas-fired instantaneous water heater delivery capacity.
Similarly, DOE proposes to remove the maximum input ratings for
gas-fired, electric, and oil-fired storage water heaters, and for gas-
fired instantaneous water heaters from the test procedure. DOE believes
that the proposed test procedure, because it varies based on delivery
capacity, is applicable to units with input capacities above those
included in the current residential water heater test procedure.
Although these maximum input limitations were based upon DOE's ``water
heater'' definition at 42 U.S.C. 6291(27), because AEMTCA requires that
the new metric apply to all water-heating technologies except those
that do not have a residential use, DOE believes that such limits are
no longer controlling or appropriate in terms of the scope of the water
heaters test procedure. As discussed in section III.A.1, given the
technology shifts that occur over time, DOE does not believe input
capacity limitations to be a consistent indicator of whether a product
has a residential use.
4. Electric Instantaneous Water Heaters
DOE's current test procedures do not contain a definition for
``electric instantaneous water heater,'' but rather have a space
reserved to define that term. 10 CFR Part 430, subpart B, appendix E,
section 1.7.1. EPCA defines ``electric instantaneous water heater'' as
having an input capacity of 12 kilowatts (kW) or less. (42 U.S.C.
6291(27)(B)) As noted by commenters and discussed in section III.A.1,
the heating power required for electric instantaneous water heaters
intended for whole-home applications is typically much higher than the
power capability commonly found in storage-type electric water heaters.
Given the emergence of electric instantaneous water heaters on the
market, DOE requested comment in the October 2011 RFI on addressing
this gap in the test procedure by prescribing a definition specifically
for the term ``electric instantaneous water heater.'' DOE noted in the
RFI that although the 24-hour simulated use test in DOE's test
procedure for instantaneous water heaters at 10 CFR Part 430, subpart
B, appendix E, section 5.2.4 is titled ``24-hour Simulated Use Test for
Gas Instantaneous Water Heaters,'' the method is also applicable for
electric instantaneous water heaters. DOE requested comment on
potential modifications to the DOE test procedure to address electric
instantaneous water heaters.
DOE received thirteen comments in support of the proposal to amend
DOE's water heater test procedure to include electric instantaneous
water heaters. (Bradford White, No. 2 at p. 1; PGE, No. 3 at p. 1; SCE,
No. 4 at p. 1; Stone Mountain Technologies, No. 5 at p. 2; AO Smith,
No. 8 at p. 1; NEEA, No. 9 at p. 2; Lochinvar, No. 10 at p. 1; AHRI,
No. 12 at p. 1; NREL, No. 14 at p. 9; NRDC, No. 20 at p. 1; Bosch, No.
17 at p. 1; AET, No. 22 at pp. 8-9; and ACEEE, No. 24 at p. 4.) DOE
received no comments opposing such an inclusion. Bradford White, AO
Smith, AHRI, NREL, AET, and ACEEE also suggested that the test
procedure should be amended to cover electric instantaneous water
heaters with heating rates higher than 12 kW in order to accommodate
units that are meant to serve whole-home applications. (Bradford White,
No. 2 at p. 1; AO Smith, No. 8 at p. 1; AHRI, No. 12 at p. 2; NREL, No.
14 at p. 9; AET, No. 22 at pp. 8-9; ACEEE, No. 24 at p. 4) AHRI and
ACEEE suggested that the test procedure for electric instantaneous
water heaters should be made applicable to water heaters with inputs up
to 25 kW (AHRI, No. 12 at p. 2; ACEEE, No. 24 at p. 4), while Bradford
White suggested an input limit of 35 kW (Bradford White, No. 2 at p.
1), and NREL recommended an input limit of 50 kW (NREL, No. 14 at p.
9). AET commented that the upper limit be based on a maximum current of
200 Amperes, which is the typical maximum value allowed in residences
in the United States. (AET, No. 22 at pp. 8-9) In response to the
January 2013 RFI, Aquarensics, UHCL1, UHCL2, and Seisco commented that
the test method should cover electric instantaneous water heaters with
input ratings in excess of 12 kW. (Aquarensics, No. 43 at p.1; UHCL1,
No. 44 at p. 1; UHCL2, No. 45 at p. 1; Seisco, No. 47 at p. 1) Further,
Aquarensics, UHCL1, UHCL2, and Seisco all commented that commercially-
available electric instantaneous water heaters that are designed for
residential applications have input ratings greater than the current
limit of 12 kW for residential electric water heaters under EPCA.
(Aquarensics, No. 43 at p. 2; UHCL1, No. 44 at p. 1; UHCL2, No. 45 at
p. 1; Seisco, No. 47 at p. 3) Aquarensics and UHCL2 noted residential
applications that used units with an input rating of 28 kW. UHCL1
commented that whole-house instantaneous water heaters typically
require 25 kW to 35 kW.
[[Page 66210]]
Seisco stated that residential electric instantaneous water heaters
having inputs above 30 kW are commonly built and have been used for
residential applications since 1999. Seisco further stated that
electric instantaneous water heaters with input ratings up to 35 kW are
used for whole-house applications.
After considering the comments on the RFIs, DOE proposes to amend
its water heaters test procedure to include applicable provisions for
electric instantaneous water heaters, and to define the term ``electric
instantaneous water heater'' as follows:
Electric Instantaneous Water Heater means a water heater that uses
electricity as the energy source, initiates heating based on sensing
water flow, is designed to deliver water at a controlled temperature of
less than 180[emsp14][deg]F (82 [deg]C), and has a manufacturer's
specified storage capacity of less than 2 gallons (7.6 liters). The
unit may use a fixed or variable power input.
DOE notes that the proposed definition would encompass both
electric instantaneous water heaters that are residential (i.e., with
an input capacity of 12 kW or less) and commercial (i.e., with an input
capacity greater than 12 kW). Because water heaters both above and
below 12 kW have residential applications, both types would be covered
by the uniform efficiency descriptor. Today's proposed rule provides
for a maximum flow rate test, as well as a test to obtain the energy
efficiency expressed in terms of Energy Factor (EF). These tests are
identical to those implemented for gas instantaneous water heaters.
B. Uniform Efficiency Descriptor
AEMTCA provided the following options for the uniform efficiency
descriptor metric: (1) A revised version of the energy factor
descriptor currently in use; (2) the thermal efficiency and standby
loss descriptors currently in use; (3) a revised version of the thermal
efficiency and standby loss descriptors; (4) a hybrid of descriptors;
or (5) a new approach. (42 U.S.C. 6295(e)(5)(G)) In the January 2013
RFI, DOE requested comment on the appropriate metric to be used as the
uniform descriptor. 78 FR 2340, 2344-45 (Jan. 11, 2013). Eight parties
provided comments supporting the use of the energy factor metric, but
obtained using a different method of test than provided in the current
test procedure. (NREL, No. 29 at p. 1; Bradford White, No. 30 at p. 1;
AHRI, No. 33 at p. 3; AO Smith, No. 34 at p. 2; GE, No. 36 at p. 1;
NEEA, No. 37 at p. 1; Rheem, No. 38 at p. 3; HTP, No. 41 at p. 3) The
joint comment indicated that the existing energy factor metric is
inadequate and indicated support for a series of simulated use tests
that would result in a revised energy factor. (Joint comment, No. 35 at
p. 1) No comments were received that proposed the use of thermal
efficiency, standby loss factor, or any new metrics.
NREL stated that the thermal efficiency and standby loss metrics
are not suitable as primary metrics for residential applications,
because they do not completely capture performance. (NREL, No. 29 at p.
1) AHRI and HTP indicated that the energy factor metric would enable
testing agencies to build on prior experience in testing water heaters
for residential applications, that it would result in an easier
conversion from the current metric to the uniform descriptor, and that
it can be technology neutral. (AHRI, No. 33 at pp. 3-4; HTP, No. 41 at
p. 3) HTP also suggested a voluntary rating for combined water-heating
and space-heating appliances based on ASHRAE Standard 124, Methods of
Testing for Rating Combination Space-Heating and Water-Heating
Appliances. (HTP, No. 41 at p. 4) AO Smith suggested that the uniform
descriptor be given a qualifying name to distinguish it from the
current energy factor, providing ``New Energy Factor'' as an example.
(AO Smith, No. 34 at p. 2) GE indicated that an energy factor metric
would be technology neutral and that it would minimize complexity in
converting from the current metric to the uniform descriptor. (GE, No.
36 at p. 1)
NRCan provided a report documenting results of testing of two
commercial water heaters that are marketed towards the residential
sector under the existing residential test procedure. (NRCan, No. 42 at
p. 1) The report did not identify any problems or concerns with testing
these units under the existing test procedure.
Based on these comments, DOE proposes a modified version of the
existing energy factor metric as the uniform descriptor for products
covered under this test procedure. DOE believes that an energy factor
that is derived from a simulated use test will provide a technology-
neutral metric for the efficiency of water heaters intended for
residential applications. The simulated use test will capture key
performance aspects such as burner efficiency, standby loss, and
cycling that affect energy efficiency seen by consumers. However, DOE
will not adopt voluntary rating requirements for combination appliances
at this time, as that is outside the scope of today's test procedure
NOPR. Further, DOE does not plan to change the name, as suggested by
A.O. Smith. The Department believes that because standards and ratings
will be transitioned to the new metric and the old metric will be come
obsolete, there will be little confusion by maintaining the name
``energy factor.''
C. Draw Pattern
The term ``draw pattern'' describes the number, flow rate, length,
and timing of hot water removal from the water heater during testing.
Primary decisions in developing draw patterns include the total amount
of water to be removed during the test and the number of draws during
the test. The total amount of water taken in each draw, which is a
function of the flow rate and the length of the draw, must also be
specified. Finally, the spacing between those draws is needed to
complete the specification of the draw pattern.
The current residential water heater test procedure includes a 24-
hour simulated-use test for determining energy factor. 10 CFR Part 430,
subpart B, appendix E, sections 5.1.5 and 5.2.4. The 24-hour test
specifies that 6 draws of equal volume be removed from the water heater
in the first 6 hours of the test for a total draw of 64.3
1.0 gallons (243.4 3.8 L).\9\ Following the six draws, the
water heater sits in an idle mode for the remainder of the 24-hour
test. Id. The draw pattern is the same regardless of the type (e.g.,
gas-fired, electric resistance, oil-fired, heat pump, storage,
instantaneous) and characteristics (e.g., storage volume, input
capacity) of the water heater.
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\9\ 10 CFR Part 430, subpart B, appendix E, section 5.1.5
currently states, ``During the simulated use test, a total of 64.
3 1.0 gallons (243 2.8 liters) shall be
removed.'' DOE contends that the total is in error and should
instead read ``64.3 1.0 gallons (243 2.8
liters).'' No correction is proposed at this time since the quantity
will change in the proposed test procedure.
---------------------------------------------------------------------------
In the October 2011 RFI, DOE noted that recent data
10 11 12 suggest that the draw pattern can impact the energy
factor of a water heater and can potentially offer an advantage to one
type of water heater technology over another. 76 FR 63211, 63213 (Oct.
12, 2011). These studies also suggest that the existing draw pattern in
the simulated use test may not be
[[Page 66211]]
representative of actual draw patterns to which water heaters are
subjected in the field. Because different water heaters will be
subjected to different field demands (consumer usage patterns) due to
operational or performance differences, DOE proposes to revise the draw
pattern to be more representative of typical usage patterns experienced
in the field. DOE is also proposing to amend its test procedure to
provide for different draw patterns for different water heaters based
upon the characteristics of each water heater, such as the rate of hot
water the unit can provide, the storage volume, and the heating rate
(i.e., input rate). In the October 2011 RFI, DOE sought comment on
improvements that could be made to DOE's existing 24-hour simulated use
test procedure for water heaters. Additional comments were sought by
and provided in response to the January 2013 RFI.
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\10\ Healy, WM, Ullah, T, and Roller, J., ``Input-Output
Approach to Predicting the Energy Efficiency of Residential Water
Heaters--Testing of Gas Tankless and Electric Storage Water
Heaters,'' ASHRAE Transactions 117 (2011).
\11\ Hoeschele, M.A. and Springer, D.A., ``Field and Laboratory
Testing of Gas Tankless Water Heater Performance,'' ASHRAE
Transactions 114 (2): 453-461 (2008).
\12\ Bohac, D, Schoenbauer, B., Hewett, M., Lobenstein, M.S.,
Butcher, T. ``Actual Savings and Performance of Natural Gas Tankless
Water Heaters,'' Center for Energy and Environment Report for
Minnesota Office of Energy Security (August 30, 2010).
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DOE received 27 comments that addressed these issues. Four
commenters (AGA, Bosch, General Electric, and Rheem) recommended that
DOE maintain the test procedure as it currently stands. AGA argued the
importance of consistency with previous ratings. (AGA, No. 13 at p. 1)
Bosch commented that the current test procedure covers a large quantity
of applications without trying to estimate the usage for any given
household. (Bosch, No. 17 at p. 2) General Electric wrote that the six-
draw requirement is appropriate for medium-volume water heaters. (GE,
No. 21 at pp. 1-2) Rheem suggested that the added scope of covered
products called for by AEMTCA would best be handled by maintaining the
existing residential water heater test procedure at this time while
continuing to pursue an amended test method. (Rheem, No. 38 at p. 3)
Rheem further argued that such an incremental approach would allow
manufacturers to continue on a path to meet minimum efficiency
requirements imposed by amended energy conservation standards.
In total, DOE received twenty-three comments recommending that the
Agency move away from the six-draw requirement as currently specified
in the DOE test procedure (although certain of these comments were
multiple submissions from the same interested party). (Bradford White,
No. 2 at p. 2; PGE, No. 3 at p. 2; SCE, No. 4 at p. 2; Stone Mountain
Technologies, No. 5 at p. 2; AO Smith, No. 8 at p. 2; NEEA, No. 9 at p.
2; NPGA, No. 11 at pp. 1-2; AHRI, No. 12 at p. 2; NREL, No. 14 at pp.
1-2; GTI, No. 15 at p. 2; NRCan, No. 16 at pp. 1-2; NRDC, No. 20 at p.
2; AET, No. 22 at p. 2; ACEEE, No. 24 at p. 1; NREL, No. 29 at p. 2;
Bradford White, No. 30 at p. 2; AHRI, No. 33 at p. 4; AO Smith, No. 34
at p. 3; Joint comment, No. 35 at p. 1; GE, No. 36 at p. 1; NEEA, No.
37 at p. 3; APGA, No. 39 at p. 2; AHRI, No. 46 at p. 1)
Bradford White indicated its support for a 24-hour simulated use
test because it is ``technology blind.'' (Bradford White, No. 2 at p.
2) PGE and SCE recommended that the draw pattern be modified to reduce
bias towards tankless water heaters, and that different draw patterns
be applied based on the capacity of the water heater. (PGE, No. 3 at p.
2; SCE, No. 4 at p. 2) Stone Mountain Technologies indicated that
recent studies have shown that the efficiency of most gas-fired
tankless models is overstated using the current DOE test procedure. The
commenter stated that this finding, along with the addition of small
water heaters within the scope of the test procedure, necessitate a
modification to the current draw pattern. Further, Stone Mountain
Technologies opined that an appropriate number of draws for a practical
test method would be between 10 and 15. (Stone Mountain Technologies,
No. 5 at p. 2) AO Smith and AHRI supported revising the test procedure
while retaining the simulated-use concept and indicated that an AHRI
industry effort is underway to develop a modified draw pattern. (AO
Smith, No. 8 at p. 2; AHRI, No. 12 at p. 2; AHRI, No. 33 at p. 4; AO
Smith, No. 34 at p. 3) AHRI submitted a proposed revised energy factor
test method to DOE, which was considered for today's NOPR and is
discussed below. (AHRI, No. 46, pp. 1-7) NEEA stated that it is clear
that the draw pattern used in the current test procedure bears no
resemblance to that seen in actual use, and accordingly, the current
draw pattern should be abandoned. (NEEA, No. 9 at p. 2) NREL commented
that the draw patterns in the new test must be statistically
representative of actual usage, meaning that the frequency
distributions of key variables in the test procedure (such as volume of
draws and timing between draws) are reasonably matched to field data.
Furthermore, it commented that DOE should ensure that any proposed test
draw profile must be consistent with all relevant statistical
distributions determined from the database of hot water draws created
by the Lawrence Berkeley National Laboratory (LBNL). (NREL, No. 14 at
pp. 1-2, 8) NREL also mentioned the efforts underway by ASHRAE to
develop a test method based on multiple draw patterns that have
different total draw volumes that are appropriate for water heaters of
different sizes. (NREL, No. 29 at p. 2) NEEA likewise discussed these
efforts by ASHRAE. (NEEA, No. 27 at p. 2)
GTI discussed the effect of a greater number of draws during the
test on the efficiency rating of instantaneous water heaters, and
presented data on estimated energy factors and efficiencies under
different draw patterns. (GTI, No. 15 at pp. 6-9) NRCan discussed
changes being proposed to the committee responsible for Canadian
Standards Association (CSA) P.3--Testing Method for Measuring Energy
Consumption and Determining Efficiencies of Gas-Fired Storage Water
Heaters. The committee is considering changing the current draw pattern
and replacing it with a new pattern of 10 to 15 draws spread throughout
the day, with the volume and time of each draw varying. NRCan also
provided data from a field study in Ontario that included information
on hot water draw patterns. (NRCan, No. 16 at p. 2) NRDC urged DOE to
examine the existing data on draw patterns and to conduct its own
further testing if necessary. (NRDC, No. 20 at p. 2) AET commented that
the draw patterns need to be more realistic in terms of the number of
repeated small draws and that it is important for tank-type,
instantaneous, and tankless water heaters to all be rated using the
same draw patterns for a given capability range, because comparisons
among them will otherwise have little meaning. (AET, No. 22 at p. 2)
ACEEE commented that the current draw pattern is no longer adequate for
generating the information that consumers need to make wise purchasing
decisions. In ACEEE's view, the six-draw test does not reflect patterns
seen in field studies and that the current six-draw pattern is
inadequate, primarily because different technologies that may lead to
the same energy use in typical applications would get quite different
EF ratings in the lab. (ACEEE, No. 24 at p. 1) Standards Committee
118.2 of ASHRAE submitted minutes from a meeting held on June 28, 2011,
indicating that the committee passed motions to develop new draw
patterns for a simulated-use test. (ASHRAE, No. 25 at pp. 1-2)
Fifteen commenters supported the implementation of different draw
patterns based upon water heater capacities. Bradford White proposed
three different draw patterns that would be applicable to water heaters
of low use, normal-to-high use, and heavy-duty use. (Bradford White,
No. 2 at pp. 5-6; Bradford White, No. 30 at pp. 13-15) PGE and SCE
recommended that DOE prescribe draw patterns based on ranges of
capacities of units or based upon burner size for tankless units. (PGE,
No.
[[Page 66212]]
3 at p. 2; SCE, No. 4 at p. 2) Stone Mountain Technologies stated that
the flow rate during individual draws and the total volume drawn during
the test should be based on the hot water delivery capacity of the
model. Furthermore, Stone Mountain Technologies suggested that the
capacity should be based on the theoretical volume of hot water that
can be delivered in 15 minutes using the energy storage and the net
heat input. (Stone Mountain Technologies, No. 5 at p. 2) AHRI and AO
Smith recommended that DOE should develop a simulated-use test that
will vary for differing models based on some specified criterion such
as storage volume or flow rate or other appropriate characteristic.
(AHRI, No. 12 at p. 2; AO Smith, No. 8 at p. 2) NEEA indicated that its
own laboratory testing and that of some others suggest that multiple
draw patterns (perhaps 3 to 5) would be appropriate, depending on the
capacity of the water heater. (NEEA, No. 9 at p. 2) NRCan indicated
that the CSA P.3 committee is considering 3 or 4 categories for daily
hot water use households: Low, medium, high, and, potentially, a point-
of-use category. The water heaters would be categorized by first-hour
rating, maximum gallons per minute, or maximum heat input. (NRCan, No.
16 at p. 2) General Electric commented that the draw pattern should be
proportionately scaled up for large volume water heaters (greater than
50 gallon capacity) and, similarly, scaled down for smaller water
heaters (less than 50 gallons). (GE, No. 21 at p. 2) ACEEE stated that
DOE must use different draw patterns for water heaters of different
capacities and suggested that manufacturers should be allowed to choose
how a particular product is rated. (ACEEE, No. 24 at p. 2) In response
to the January 2013 RFI, the joint commenters recommended 5 different
draw patterns for sizes ranging from point-of-use to very high use
household/light commercial. The joint commenters noted work by LBNL and
Stone Mountain Technologies in devising a capacity rating based on
published storage volume and heat source size. (Joint comment, No. 35
at p. 2) GE commented that water heaters should be tested based on
their capacity as measured by the first-hour rating. (GE, No. 36 at p.
1)
AHRI provided a suggested simulated use test that described four
different draw patterns that would be applied to a water heater based
on its first-hour rating or maximum flow rate measurement. (AHRI, No.
46 at pp. 5-6) As explained below, AHRI suggested cut-offs between the
four different size categories at first-hour ratings of 20, 55, and 80
gallons and at maximum flow rates of 1.5, 2.5, and 3.5 gallons per
minute; all values correspond to a nominal outlet temperature of 135
[deg]F and a nominal inlet temperature of 58 [deg]F. The draw patterns
are based on a set of activities that would be expected in a typical
residence, with the total volume removed per day for the four patterns
being 15, 40, 64.2, and 82.75 gallons. The draw pattern for point-of-
use water heaters involved 11 draws, while the other three draw
patterns involved 12 draws each. Flow rates varied for each draw during
the draw pattern, except for the point-of-use draw pattern which
imposed a fixed flow rate of 1 gallon per minute throughout the test.
Applied Energy Technology acknowledged the need to test a water
heater according to a draw pattern appropriate for its delivery
capacity, but instead of supporting a suite of tests for water heaters
of different capacity, it recommended that DOE consider a test approach
applicable to water heaters of all sizes from which pieces of
information are obtained pertaining to the particular capacity of the
water heater under test. AET's suggested test method entails a series
of draw clusters that simulate different end uses in a residence. Water
heaters with a high capacity could presumably deliver sufficiently hot
water at all times during the test, but water heaters with lower
capacity may fail to provide water at a required temperature under
those draw clusters that called for large volumes of hot water in a
short time. Under AET's approach, a water heater would be rated for
those clusters during which it could meet the demand placed upon it as
determined by the outlet temperature during those draw clusters. (AET,
No. 22 at pp. 18-37) AET commented that details of the test method
needed to be refined, and no discussion was provided as to how to use
the efficiency determined during each draw cluster for which the water
heater could meet the demand to yield an energy factor.
DOE has tentatively concluded that the current DOE test procedure's
draw pattern applied during the simulated-use test can potentially
yield results that are biased towards particular water-heating
technologies. The DOE test procedure specifies a small number of draws
per day when compared to typical usage, a relatively large time between
draws, and uniform volumes of water per draw. The test procedure
applies to all water heater technologies without regard to any inherent
differences in performance across the technologies. A revised draw
pattern in the simulated-use test that better reflects how water is
actually used in different homes using different water heater
technologies could allow for a more realistic representation of the
expected energy consumption consumers would experience for a particular
water heater technology.
A test procedure that is completely uniform across all water heater
types and sizes (i.e., no differences in the amount of hot water drawn
or the number of draws, etc.) can provide results that are biased
toward different water heater technologies. For electric resistance and
fossil fuel-fired storage water heaters, the predominant factor
affecting the energy factor is the total amount of water removed per
day. At a given set point temperature, the water heater loses heat to
the environment at an essentially constant rate regardless of the
amount of water removed. Since the energy factor is the ratio of hot
water energy delivered to the overall energy consumed by the water
heater, which is a sum of that needed to heat the water and that which
is lost to the environment, the energy factor increases when the
numerator of that ratio increases. Hence, the energy factor increases
when the amount of water delivered per 24 hours increases. The
performance of these water heaters is not expected to depend upon the
length of draws, the flow rates of draws, nor the spacing between the
draws.
Storage water heaters that rely on heat pump technology show the
same efficiency trend with overall delivered water volume per day as
seen with other storage water heater technologies, but it is also
expected that the energy factors would depend upon the way that water
is distributed among draws. A heat pump water heater operates most
efficiently when the heat pump portion of the water heater provides the
heat to the water as opposed to any backup electric resistance heating.
This backup resistance heating is needed when the hot water in the
appliance is depleted and a rapid amount of heat needs to be delivered
to raise the stored water temperature back to the desired value. Since
heat pumps tend to have a low heating rate, heat pump water heaters
currently on the market incorporate resistance elements to provide that
rapid heating. These resistance elements, however, dramatically reduce
the efficiency. In the current test procedure, water heaters that have
been tested do not require backup electric resistance heating to
maintain an adequate water temperature within the tank since there is
enough time between draws for the tank to fully recover to a
[[Page 66213]]
temperature that is above that which triggers the resistance elements.
If a revised draw pattern would require a larger amount of water to be
drawn from the water heater in a set period of time, either through a
single larger draw or multiple draws spaced close together as would be
more representative of average use, the heat pump water heater may be
forced to utilize electric resistance heating to maintain the required
tank temperature, and the energy factor would drop.
For small storage water heaters in the ``point-of-use'' category
(water heaters that generally are not intended to serve as a single
water heater for all uses in a household), a test utilizing the current
draw pattern would likely result in delivery of water during the draws
that is below a temperature that would be considered useful by the
resident. These units have a small stored volume of hot water that is
appropriate for small uses such as hand washing but not for a draw of
more than 10 gallons at 3 gallons per minute (gpm), as is imposed by
the current test procedure. An efficiency test that takes into account
these limitations should put a demand on the water heater that calls
for individual draws less than those implemented in the current DOE
test.
Draw patterns and water heater cycling frequency likely have an
effect on the measured efficiency of instantaneous water heaters.
Instantaneous water heaters typically use large burners or heating
elements to heat the water from the inlet temperature to the outlet
temperature as it flows through the appliance. The burner typically is
not energized until a water draw is initiated. Once the draw stops, the
burner is shut off, and the remaining water in the appliance and the
material making up the appliance gradually lose their heat and return
to the ambient temperature. This heat loss (losses associated with
heating up and cooling off of the burner) is considered a cycling loss,
as the loss is associated with the cycling on and off of the water
heater's main energy input.
Draw patterns affect water heater cycling and, thus, the overall
measured efficiency of the water heater. Shorter draws typically act to
lower the measured efficiency because, as the water heater cycles more
frequently, cycling losses increase. Further, cycling losses account
for a larger portion of energy usage during shorter draws, resulting in
a disproportionate amount of heat input going towards raising the
temperature of the heat exchanger as opposed to raising the temperature
of the water. Hence, shorter draws typically result in a lower measured
efficiency. However, draws that are clustered closer together typically
act to raise the measured efficiency by reducing cycling losses because
the appliance may be able to maintain an elevated temperature between
the end of one draw and the initiation of a subsequent draw. The
cycling losses are mitigated by the fact that the appliance does not
cool down as much after the end of one draw and thus does not need to
be heated as much when the subsequent draw is initiated. Hence, shorter
spacing between draws typically results in an increase in the water
heater's measured efficiency.
The efficiency of instantaneous water heaters is less affected by
the total volume of hot water delivered per day than storage water
heaters because their standby losses (i.e., losses associated with a
water heater in standby mode, independent of the cycling losses
discussed above) are negligible. Standby losses increase measured
energy consumption without a corresponding increase in energy
delivered, thereby decreasing the energy factor. An increase in the
volume of water delivered per day results in a nearly proportional
increase in energy consumption for instantaneous water heaters. The
other drivers of total energy consumption are standby heat loss and
cycling heat loss, with standby heat loss being essentially constant
during the test and cycling losses being a function of the number of
draws and their spacing. As these two losses approach zero, the
dependence of energy factor on daily draw volume decreases since the
energy consumption is dominated by that needed to heat the water, which
vary proportionally. For water heaters currently on the market, the
cycling losses experienced by instantaneous water heaters tend to be
much less than the standby losses experienced by storage water heaters.
Because standby losses increase measured energy consumption without a
corresponding increase in energy delivered, the total energy
consumption for instantaneous water heaters is much closer to the
energy needed to heat the water than that seen with storage water
heaters, and the dependence on daily draw volume is also lower.
The flow rate at which water is drawn from the water heater may
affect the measured efficiency of an instantaneous water heater. The
heat transfer from the heat exchanger to the water is a function of the
speed at which water moves through the heat exchanger; efficiency may
increase at higher flow rates. Additionally, since instantaneous water
heaters typically employ heating elements or burners with variable
capacity to meet the desired outlet temperature at different flow
rates, the efficiency of the heat input device (e.g., burner or heating
element) may also vary depending upon the heating rate. This effect
could either increase or decrease the overall efficiency depending upon
the setting to which the heating element or burner is tuned.
To summarize, under the current DOE test procedure, certain types
of water heaters can provide results that are biased toward certain
water heater technologies. The small number of draws imposed under the
existing test procedure, relative to the actual number of draws noted
in field usage data, reduces the measured cycling losses relative to
those occurring in field conditions. By contrast, the duration of time
between draws in the test procedure is relatively long when compared to
field usage data, which effectively increases the measured cycling
losses relative to those occurring in field conditions. Water heaters
with low heating rates would appear to benefit since they could easily
recover to operational temperature.
The current DOE test procedure does not adequately measure energy
efficiency during a representative average use cycle or period of use
for some technologies. The uniform volume taken during each draw of the
current test method does not simulate high-demand use, such as a long
shower, that could change the way that a water heater operates, nor
does it simulate performance under short draws during which water is
not delivered at the prescribed set point temperature. Furthermore, DOE
agrees with commenters who stated that the draw patterns should be
based on the delivery capacity of the water heater because, as
explained above, the measured water heater efficiency is influenced by
the draw pattern incorporated into the test procedure and because a
single draw pattern is not appropriate for the range of water heater
sizes that fall under the scope of this test procedure. Consequently,
DOE proposes a revised simulated-use test that involves four different
draw patterns for water heaters of different capacities. Water heaters
would be classified into the following usage categories (described
below) corresponding to their usage capacity: (1) Point-of-use; (2)
low; (3) medium; and (4) high. The proposed classifications are based
on delivery capacity as determined in a first-hour rating test for
storage-type water heaters or a maximum flow rate test for
instantaneous water heaters.
In crafting a proposed set of draw patterns, DOE considered and
utilized
[[Page 66214]]
the recommended draw patterns submitted by commenters, in particular
those submitted by Bradford White (Bradford White, No. 2 at p. 3;
Bradford White, No. 30 at p. 11), AHRI (AHRI, No. 46 at p. 3), and AET
(AET, No. 22 at p. 1). (DOE notes that no test data were supplied with
any of the proposed test methods.) Additionally, DOE utilized data
compiled by the LBNL \13\ that describes field studies of hot water
usage to ensure that the draw patterns were representative of field
use. LBNL found that typical usage in residences in North America is
characterized by a large number of small volume draws, by a smaller
volume of water per day than is currently prescribed in the residential
test method, and by a significant variation in draw volume and number
of draws per day. The data suggest development of a single typical draw
pattern would be difficult and inappropriate. Instead, DOE has
attempted to develop several draw patterns that capture key features
affecting performance (e.g., length and frequency of draws, flow
rates), while maintaining a test that will not be overly burdensome to
conduct and which will produce repeatable results.
---------------------------------------------------------------------------
\13\ Lutz, JD, Renaldi, Lekov A, Qin Y, and Melody M., ``Hot
Water Draw Patterns in Single Family Houses: Findings from Field
Studies,'' Lawrence Berkeley National Laboratory Report number LBNL-
4830E (May 2011) (Available at https://www.escholarship.org/uc/item/2k24v1kj) (last accessed October 18, 2013).
---------------------------------------------------------------------------
Based upon this understanding, DOE proposes the following draw
patterns containing volumes per day that are consistent with the data
found by LBNL. The proposed low-use pattern calls for the water heater
to provide 38 gallons per day, which is consistent with the median
values found for households with 1 to 2 occupants. The proposed medium-
use pattern, which requires a supply of 55 gallons per day, is
consistent with the median values found for households with 3 to 4
occupants. The LBNL data show a median volume of hot water used for
families with 5 or more occupants to be approximately 58 gallons. This
unexpectedly low result might be attributable to the lower sample
number of such large households. For this reason, DOE has departed from
the LBNL field data and proposes a total volume of 84 gallons per day
for the high-use pattern. This value is consistent with that proposed
by Bradford White (Bradford White, No. 2 at p. 5) and AHRI (AHRI, No.
46 at p. 6), and DOE believes that it is a representative number for
high use cases based on the range of hot water usage per day reported
by LBNL. While the LBNL report suggests that the number of draws of hot
water per day could exceed 50, DOE has tentatively determined that
imposing a draw pattern during a test with that many draws could lead
to measurement difficulties owing to (1) the need to measure energy
removal in such short draws; and (2) the potential variation inherent
in precisely controlling so many draws. Accordingly, DOE has
tentatively concluded that a smaller number of draws (ranging from 9 to
14) will strike a balance between the need to capture cycling losses
associated with water heater operation and the need for accurate
measurement. Additionally, many of the short draws found in field tests
are clustered close together in time. In these situations, cycling
losses are negligible because the water heater remains at operational
temperature over the course of the smaller draws. For these draws,
energy efficiency can be reliably estimated by consolidating the
multiple draws into a single larger draw.
As discussed in section III.F, ``Test Conditions,'' DOE proposes
that both the first-hour rating test and the maximum flow rate test
will be carried out with the prescribed outlet water temperature at 125
[deg]F. DOE proposes to modify the first-hour rating test to stop draws
of hot water when the outlet water temperature drops 15 [deg]F below
its maximum temperature during each draw. This cut-off temperature is a
departure from the current test, which cuts off the draw when the
outlet water temperature drops 25 [deg]F below the maximum recorded
outlet temperature. With the nominal delivery temperature being 135
[deg]F in the current test procedure, the cut-off temperature is 110
[deg]F. This proposed change in temperature drop to trigger the end of
a draw would maintain the approach that the minimum useful temperature
of hot water is 110 [deg]F. This value is consistent with Table 3,
Chapter 50 of the ASHRAE Handbook of HVAC Applications,\14\ which
indicates that a representative temperature for showers and tubs is 110
[deg]F. For water heaters with rated storage volumes at or above 20
gallons, water will continue to be drawn at 3 gallons per minute during
the first-hour rating test. For water heaters having rated storage
volumes below 20 gallons that are not designed to provide a continuous
supply of hot water, water will be drawn at a rate of 1 gallon per
minute during the first-hour rating test. A water heater that is
designed to provide a continuous supply of hot water at the set point
temperature \15\ will be tested to obtain a maximum flow rate, while
water heaters that are not so designed will be subject to a first-hour
rating test.
---------------------------------------------------------------------------
\14\ ASHRAE 2011, Handbook of HVAC Applications, Chapter 50
Service Water Heating (Available at: https://www.ashrae.org/resources-publications/handbook).
\15\ A set point temperature is the temperature that the user
selects via a thermosat as the temperature of the delivered hot
water at the outlet of the water heater.
---------------------------------------------------------------------------
DOE proposes the following ranges of first-hour ratings and maximum
flow rates to characterize storage and instantaneous water heaters,
respectively:
Point-of-use:
First-Hour Rating less than 20 gallons.
Maximum Flow Rate less than 1.7 gallons per minute (gpm).
Low:
First-Hour Rating greater than or equal to 20 gallons, less than 55
gallons.
Maximum Flow Rate greater than 1.7 gpm, less than 2.8 gpm.
Medium:
First-Hour Rating greater than or equal to 55 gallons, less than 80
gallons.
Maximum Flow Rate greater than or equal to 2.8 gpm, less than 4
gpm.
High:
First-Hour Rating greater than or equal to 80 gallons.
Maximum Flow Rate greater than or equal to 4 gpm.
DOE based these proposed ranges (or ``bins'') on first-hour rating
data for existing models, requirements of the current plumbing code,
and recommended cut-offs proposed by Bradford White and AHRI. (Bradford
White, No. 2 at pp. 4-5; Bradford White, No. 30 at p. 2; AHRI, No. 46
at p. 4) In today's NOPR, DOE proposes to modify the set point
temperature from the current 135 [deg]F to 125 [deg]F, as discussed
further in section III.F.1. While it is acknowledged that the published
first-hour rating data were taken at a set point temperature of 135
[deg]F, limited testing shows that first-hour ratings at a set point
temperature of 125 [deg]F are comparable to those at 135 [deg]F. The
first-hour ratings of all water heaters on the market cluster around
certain values to accommodate different levels of use. Those clusters
are captured in the bins proposed here. DOE's proposed bins differ from
those presented by Bradford White in its comments on the October 2011
RFI and the January 2013 RFI, because the commenter's approach grouped
medium-use and high-use water heaters into a common category and added
a category for water heaters meant for so-called ``heavy-duty use.''
(Bradford White, No. 2 at pp. 4-5) DOE
[[Page 66215]]
has tentatively concluded that the categories defined by Bradford White
group too many water heaters in the mid-use category. DOE's proposed
first-hour rating categories match those proposed by AHRI. DOE believes
that these breakpoints are appropriate based on minimum first-hour
ratings required by the Uniform Plumbing Code.\16\ The code mandates
minimum first-hour ratings for water heaters serving homes with
different combinations of bedrooms and bathrooms. Four different
minimum values are implemented by the code: 42, 54, 67, and 80 gallons.
---------------------------------------------------------------------------
\16\ International Association of Plumbing and Mechanical
Officials, ``2012 Uniform Plumbing Code'' (2012) (Available at
www.iapmo.org) (last accessed March 29, 2013).
---------------------------------------------------------------------------
DOE has tentatively concluded that its proposed usage categories
are appropriate, given that they are consistent with the Uniform
Plumbing Code, albeit with certain minor modifications. In considering
the Uniform Plumbing Code, DOE considered 42 gallons per day as a lower
limit for the low-use category, but concluded that it would not be
realistic for a water heater intended to provide point-of-use
functionality to deliver up to that level of water in one hour.
Instead, DOE has tentatively decided to set the upper limit for point-
of-use water heaters and the lower limit for low-use water heaters at
20 gallons per day. While water heaters with first-hour ratings below
42 gallons per day may not be used as a single water heater for whole-
house applications, DOE believes that their use more closely resembles
that of low-use water heaters rather than that of point-of-use water
heaters. DOE has grouped homes with 2 to 4 bedrooms and less than 3
bathrooms in the medium category, which would require minimum first-
hour ratings of 54 or 67. Five bedroom homes with up to 2.5 bathrooms
or homes with three or more bathrooms would require water heaters with
first-hour ratings at least 80 gallons per day; these water heaters fit
into the proposed high-use category.
DOE acknowledges the uncertainty in using data generated under the
existing test procedure, which are based on a first-hour rating test
conducted at a delivery temperature of 135 [deg]F, for establishing
bins for the applicable draw patterns. Testing by DOE has indicated
that storage water heaters with relatively high recovery rates yield
higher first-hour ratings under the proposed procedure than under the
current procedure, while those with low recovery rates tend to have
slightly lower first-hour ratings at 125 [deg]F compared to the rating
at 135 [deg]F. DOE seeks comments related to the translation of current
first-hour ratings to a first-hour rating determined using the proposed
125 [deg]F set point and the proposed breakpoints between the different
size categories. This is identified as issue 2 in section V.E, ``Issues
on Which DOE Seeks Comment.''
The proposed maximum gpm ratings for instantaneous water heaters
were devised based on expected uses for water heaters serving
applications of different sizes. The categorizations are consistent
with those suggested by AHRI, with the ratings being scaled up to
account for the higher maximum flow rates expected at the lower set
point temperature (125 [deg]F).
DOE seeks comment on the proposed criteria for characterizing water
heaters as point-of-use, low usage, medium usage, and high usage, and
whether these criteria are appropriate and sufficient. This is
identified as issue 3 in section V.E, ``Issues on Which DOE Seeks
Comment.''
For each sizing category, DOE proposes to apply a 24-hour
simulated-use test to determine the energy factor. One of four separate
draw patterns would be applied to each water heater based on the
appropriate sizing category. The draw patterns would have the following
number of draws per day: Point-of-use: 9; low: 11; medium: 12; and
high: 14. DOE acknowledges that the number of draws per day in a
typical household can often approach 100 and that the volume in each
draw can be very small. However, DOE believes that a test with so many
draws would be subject to large variability in results due to the
challenges in accurately determining the energy content of such short
draws. In contrast, DOE has tentatively concluded that the proposed
draw patterns would capture the key ways in which hot water is used in
residences while yielding a test that is repeatable.
DOE's proposal uses a slightly modified version of the draw
patterns submitted by Bradford White and AHRI in response to the
January 2013 RFI as a basis for the low, medium, and high draw
patterns; Bradford White did not submit a draw pattern for point-of-use
water heaters. In addition, the patterns presented by Bradford White
grouped medium-use water heaters with heavy use, so data were missing
for both point-of-use and medium use water heaters. Additionally,
information provided by AET has also been considered to craft some
aspects of the draw patterns. AET provided information on typical uses
that would be applied to a water heater in terms of flow rates, number
of draws, and volumes. (AET, No. 22 at pp. 22-36) This information was
utilized in drafting the proposed draw patterns for point-of-use and
medium-use water heaters.
A number of changes are proposed as compared to the current draw
patterns found in the DOE simulated-use test procedure. First, the
proposed draw patterns would involve more draws than are currently
implemented, and the draws would vary in length during the simulated-
use test. Second, the spacing between the draws would vary to better
capture the effects of different cycling times on the energy efficiency
of the water heater. Third, the proposed draws would involve different
flow rates during the test; these flow rates would be 1.0, 1.7, or 3.0
gpm.\17\ The total volumes that would be removed for each category are
in line with recent field data compiled by the Lawrence Berkeley
National Laboratory that was previously discussed. DOE believes that
the proposed draw patterns would improve the estimation of energy
efficiency by considering the impact of shorter draws, lower flow
rates, higher number of draws, and variable standby times between
draws.
---------------------------------------------------------------------------
\17\ For point-of-use models, the flow rate is specified as the
lesser of 1 gpm or the maximum gpm. Therefore, if a unit were to
have a maximum gpm rating below 1.0 gpm, that unit would be tested
at its maximum gpm flow rate.
---------------------------------------------------------------------------
DOE proposes draw patterns for implementation in the 24-hour
simulated-use tests as outlined in Table III.2 through Table III.5. The
total volume of water drawn in the proposed draw patterns are 10
gallons for the point-of-use pattern, 38 gallons for the low-usage
pattern, 55 gallons for the medium-usage pattern, and 84 gallons for
the high-usage pattern.
[[Page 66216]]
Table III.2--Point-of-Use Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume
Draw number test (hh:mm) (gallons) Flow rate (gpm)
----------------------------------------------------------------------------------------------------------------
1.................................. 0:00 2 Lesser of (1, max gpm).
2.................................. 1:00 1 Lesser of (1, max gpm).
3.................................. 1:05 0.5 Lesser of (1, max gpm).
4.................................. 1:10 0.5 Lesser of (1, max gpm).
5.................................. 1:15 0.5 Lesser of (1, max gpm).
6.................................. 8:00 1 Lesser of (1, max gpm).
7.................................. 8:15 2 Lesser of (1, max gpm).
8.................................. 9:00 1.5 Lesser of (1, max gpm).
9.................................. 9:15 1 Lesser of (1, max gpm).
----------------------------------------------------------------------------------------------------------------
Table III.3--Low-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume Flow rate
Draw number test (hh:mm) (gallons) (gpm)
----------------------------------------------------------------------------------------------------------------
1................................................................. 0:00 15.0 1.7
2................................................................. 0:30 2 1
3................................................................. 1:00 1 1
4................................................................. 10:30 6 1.7
5................................................................. 11:30 4.0 1.7
6................................................................. 12:00 1.0 1
7................................................................. 12:45 1.0 1
8................................................................. 12:50 1.0 1
9................................................................. 16:15 2.0 1
10................................................................ 16:45 2.0 1.7
11................................................................ 17:00 3.0 1.7
----------------------------------------------------------------------------------------------------------------
Table III.4--Medium-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume Flow rate
Draw number test (hh:mm) (gallons) (gpm)
----------------------------------------------------------------------------------------------------------------
1................................................................. 0:00 15 1.7
2................................................................. 0:30 2.0 1
3................................................................. 1:40 9.0 1.7
4................................................................. 10:30 9.0 1.7
5................................................................. 11:30 5.0 1.7
6................................................................. 12:00 1.0 1
7................................................................. 12:45 1.0 1
8................................................................. 12:50 1.0 1
9................................................................. 16:00 1.0 1
10................................................................ 16:15 2.0 1
11................................................................ 16:45 2.0 1.7
12................................................................ 17:00 7.0 1.7
----------------------------------------------------------------------------------------------------------------
Table III.5--High-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume Flow rate
Draw number test (hh:mm) (gallons) (gpm)
----------------------------------------------------------------------------------------------------------------
1................................................................. 0:00 27 3
2................................................................. 0:30 2.0 1
3................................................................. 0:40 1 1
4................................................................. 1:40 9.0 1.7
5................................................................. 10:30 15 3
6................................................................. 11:30 5.0 1.7
7................................................................. 12:00 1.0 1
8................................................................. 12:45 1.0 1
9................................................................. 12:50 1.0 1
10................................................................ 16:00 2.0 1
11................................................................ 16:15 2.0 1
12................................................................ 16:30 2.0 1.7
13................................................................ 16:45 2.0 1.7
14................................................................ 17:00 14.0 3
----------------------------------------------------------------------------------------------------------------
[[Page 66217]]
For instantaneous water heaters with maximum flow rates less than 1
gpm, DOE proposes that the flow rates during all draws of the point-of-
use test will be set at the maximum gpm as determined during that test.
DOE also proposes to tighten the tolerance on the volume removed in
each draw from 0.5 gallons to 0.25 gallons since these patterns involve
smaller draw volumes than in the current procedure.
DOE proposes to utilize interim metrics during testing that would
be used in calculations to normalize the test to standard conditions,
as in the current test procedure, to account for deviations from the
prescribed storage tank temperature, ambient temperature, water
delivery temperature, and inlet water temperature. The standby loss
coefficient is one interim metric that would be determined during the
longest standby portion of each test in which no recovery or draws are
taking place. The recovery efficiency is a second interim metric that
would be determined based on the first draw of each test, with the
energy supplied and consumed during subsequent draws being accounted
for when a complete recovery does not occur prior to the second draw.
DOE proposes to abandon the determination of recovery efficiency at
different flow rates as currently done for instantaneous water heaters;
test data have shown the difference between these recovery efficiencies
as being less than five percent, and the resulting effect on the energy
factor is negligible.
DOE notes that the proposed draw patterns differ slightly from
those suggested by AHRI in response to the January 2013 RFI. (AHRI, No.
46 at pp. 5-6) In DOE's view, the proposed draw patterns appropriately
differentiate between the size categories by increasing the number of
draws as the size of the water heater increases. DOE also intends to
minimize the different number of flow rates required for all tests,
with the proposed draw patterns involving three different flow rates as
opposed to the four specified by AHRI. The patterns proposed here have
also been formulated to allow for the determination of key performance
metrics that are needed for computing the energy factor, namely
recovery efficiency and standby loss coefficient. DOE believes that the
proposed patterns will ease those determinations. Finally, DOE has
conducted testing according to the proposed patterns to validate the
procedure and make adjustments as needed, whereas AHRI has not
indicated that its specific patterns presented have been validated. In
any event, DOE has tentatively concluded that the draw patterns
proposed in today's NOPR are very similar to the patterns proposed by
AHRI, and that little difference will be observed between ratings
collected from either draw pattern. This assessment is based on the
fact that the total volumes drawn per day for each category are
comparable, the number of draws per day is comparable, and each pattern
is based on a distribution that represents a cluster of draws in the
morning and another cluster in the evening hours. Consequently, DOE has
tentatively concluded that the patterns proposed in this NOPR are
consistent with those presented by AHRI. DOE seeks comment on whether
the proposed draw patterns for the different water heater size
categories are appropriate. This is identified as issue 4 in section
V.E, ``Issues on Which DOE Seeks Comment.''
D. Instrumentation
DOE proposes to maintain the instrumentation installation
requirements and piping configuration as currently specified in the
residential water heater test procedure. Bradford White recommended
that the internal temperature probe required in the current test
procedure be eliminated and that all exposed piping on the inlet and
outlet of the water heater be eliminated as much as possible. (Bradford
White, No. 30 at p. 2) DOE is concerned that the removal of the
internal temperature probe would not enable the critical correction for
stored energy inside the water heater, a value that could move the
energy factor by several points. For this reason, DOE proposes to
maintain the internal temperature probe inside the tank of a storage
water heater. DOE is also proposing to maintain the piping
configuration as currently specified in the residential water heater
test procedure, as some water heaters include particular technologies
such as heat traps that minimize losses through piping connections. For
storage water heaters having a rated volume below 20 gallons, which are
not covered in the existing DOE test method, DOE proposes that the
average tank temperature would be determined based on three temperature
sensors located within the storage tank as opposed to the currently
required six sensors for storage water heaters having a rated volume
above 20 gallons. The three sensors would be located at the vertical
midpoints of three sections of equal volume within the tank. For these
units, DOE believes that three sensors are sufficient for determining
the mean tank temperature and that the use of six sensors would provide
little extra information and may add to the parasitic heat losses from
these smaller units.
DOE proposes to tighten the allowed accuracy on electric power and
energy measuring equipment from the current value of 1
percent to 0.5 percent. A study has shown the significant
effect of the accuracy of the electric power measurements on the
uncertainty in the overall energy factor.\18\ An analogous change was
made in ASHRAE 118.2-2006, ``Method of Testing for Rating Residential
Water Heaters,'' and DOE research confirms that equipment having this
tolerance level can be readily procured. DOE also proposes to require
that for mass measurements greater than or equal to 10 pounds (4.5 kg),
a scale that is accurate within 0.5 percent of the reading
be used to make the measurement.
---------------------------------------------------------------------------
\18\ Healy WM, Lutz JD, and Lekov AB., ``Variability in Energy
Factor Test Results for Residential Electric Water Heaters,'' HVAC&R
Research, vol. 9, No. 4 (October 2003).
---------------------------------------------------------------------------
DOE also proposes to modify the data acquisition rate of the inlet
and outlet water temperature during draws. Currently, for all water
heaters except variable firing rate instantaneous water heaters,
temperature data measurements are taken at 5-second intervals starting
15 seconds after the draw commences. For instantaneous water heaters
with a variable firing rate, temperature data measurements are taken at
5-second intervals starting 5 seconds after the draw commences. The
proposed test procedure amendments call for temperature data at the
inlet and outlet temperature sensors to be recorded at 3-second
intervals starting 5 seconds after commencement of the draw for all
water heaters. Accordingly, DOE also proposes to require that the time
constant of the instruments used to measure the inlet and outlet water
temperatures be no greater than 2 seconds. DOE anticipates that this
approach would better capture the energy impact of water heater start-
up and cycling.
E. Discrete Performance Tests
In the October 2011 RFI, DOE considered using a series of discrete
tests as an alternative approach to using a single 24-hour simulated-
use test to determine the energy factor of residential water heaters.
In a series of discrete performance tests, the results of various
individual tests (e.g., thermal efficiency test, recovery efficiency
test, standby loss test) would be used to calculate the energy factor.
This approach would reduce testing burden, yield more repeatable
results, and provide the ability to predict
[[Page 66218]]
performance over a broader range of applications. DOE requested
comments on the feasibility and equitability of a series of discrete
tests in the October 2011 RFI. 76 FR 63211, 63214 (Oct. 12, 2011).
Two commenters (ACEEE, NREL) supported the general premise of
discrete performance tests for rating water heaters, while
acknowledging the challenges in implementing such an approach. More
specifically, NREL indicated that studies are needed to validate that
discrete tests would provide a computed energy factor with a level of
accuracy equal to or better than a single simulated-use test. (NREL,
No. 14 at p. 5) ACEEE indicated that discrete tests combined with an
algorithm to determine the energy factor could reduce test time,
produce ratings at a variety of usage patterns with a single set of
tests, and could be used to account for novel features implemented by
manufacturers to improve efficiency. ACEEE also acknowledged that the
algorithms would still need to be developed and validated, a process
with an unknown time frame. (ACEEE, No. 24 at pp. 2-3)
Eleven commenters (Stone Mountain Technologies, AO Smith, NEEA,
NPGA, AHRI, AGA, GTI, Bosch, NRDC, General Electric, and AET) opposed
the use of discrete tests to determine the energy factor. AHRI and AO
Smith stated that such tests have a limited use relative to the wide
range of technologies being employed in current designs of residential
water heaters since they would not be as equitable as a simulated-use
approach. (AHRI, No. 12 at p. 2; AO Smith, No. 8 at p. 2) GTI commented
that much uncertainty remains in the analytical methodology for
generating rating metrics, its comparability across equipment
categories, and whether the outcome would actually yield a simpler and
more repeatable alternative to the current test procedure. (GTI, No. 15
at p. 2) Stone Mountain Technologies stated that testing and analysis
to date do not support such an approach. (Stone Mountain Technologies,
No. 5 at p. 3) Bosch expressed support for the current draw profile and
test approach because of what the commenter perceives as the extremely
low repeatability and accuracy of test results at low input rates and
the lack of data on appropriate draw patterns for use in calculating
the energy factor. (Bosch, No. 17 at p. 2) General Electric expressed
support for the current draw profile and test approach, arguing that it
would more accurately focus on actual results and more closely
approximate the real-world performance of residential water heaters.
(GE, No. 21 at pp. 1-2) NEEA stated that the concept of using discrete
performance tests to determine energy factor is not practical. (NEEA,
No. 9 at p. 3) AGA commented that discrete performance tests have been
shown to develop inconsistent results and impose new uncertainties in
testing, and NRDC raised questions about the equitability of testing
between technology types. (AGA, No. 13 at pp. 1-2; NRDC, No. 20 at p.
2) AET stated that it does not believe that the approach would work in
practice because of controls not working as designed, the presence of
multiple operating modes on water heaters, and the need to conduct more
characterization tests than initially expected. These issues with
discrete performance tests would make the algorithms used to obtain an
energy factor prone to error. (AET, No. 22 at pp. 5-6)
DOE has decided not to pursue the use of discrete performance tests
for rating the energy efficiency of residential water heaters given the
potential inequity in test results across technologies, the added
uncertainties in ratings, and the general lack of potentially suitable
algorithms to develop an energy factor for water heaters. Rather, as
discussed previously in section III.C, DOE is maintaining the single
simulated-use test, which DOE believes can be a more, technology-blind
method for determining the energy efficiency (EF) of water heaters.
F. Test Conditions
1. Water Delivery Temperature
The current residential water heater test procedure calls for
average hot water temperature within the storage tank to be set for
delivery at 135 [deg]F 5 [deg]F (57.2 [deg]C
2.8 [deg]C). 10 CFR part 430, subpart B, appendix E, section 2.4.
However, DOE noted in the October 2011 RFI that the Underwriters
Laboratories (UL) standards specify that manufacturers must ship
residential water heaters with thermostats set at temperatures no
greater than 125 [deg]F (52 [deg]C) to safeguard against scalding
hazards (UL 174, Standard for Household Electric Storage Tank Water
Heaters, Underwriters Laboratories (April 29, 2004)). DOE also noted
that DOE's own research suggests that although the majority of water
heaters are shipped with the thermostat preset to 120 [deg]F (49
[deg]C), the average set point in use in the field is 124.2 [deg]F
(51.2 [deg]C), suggesting that some homeowners or installers adjust the
thermostat. 76 FR 63211, 63214 (Oct. 12, 2011).
The set point impacts the performance of various types of water
heaters differently, and as a result, DOE reexamined the
appropriateness of the set point specification in the proposed test
procedure. As noted in the October 2011 RFI, a higher delivery
temperature has a disproportionately large and negative impact on heat
pump water heater efficiency (as compared to other types of water
heaters), because heat pump water heaters can have markedly different
performance at elevated stored water temperature compared to
temperatures more representative of typical residential usage. For
other types of water heaters, heat transfer characteristics between the
heating source and the water may differ at lower delivery temperatures,
thereby affecting the efficiency. 76 FR 63211, 63214 (Oct. 12, 2011).
However, DOE also noted in the October 2011 RFI that there are some
concerns with using a lower set point temperature in the test
procedure: (1) Some end uses (e.g., dishwasher operation) require hot
water delivered at 130 [deg]F to 140 [deg]F (54 [deg]C to 60 [deg]C)
for effective operation; and (2) there may be the potential for the
growth of Legionella in hot water stored below 135 [deg]F (57
[deg]C).\19\
---------------------------------------------------------------------------
\19\ ASHRAE Guideline 12, ``Minimizing the Risk of Legionellosis
Associated with Building Water Systems,'' states that the
temperature range most favorable for amplification of legionellae
bacteria is 77\0\-108 \0\F (25\0\-42 \0\C), and that document
recommends that when practical, hot water should be stored at
temperatures of 120 \0\F (49 \0\C) or above. However, the guideline
also states that for high-risk situations (such as in health care
facilities and nursing homes), hot water should be stored above 140
\0\F (60 \0\C). For more information visit: www.ashrae.org.
---------------------------------------------------------------------------
DOE sought comment on the appropriate set point temperature for the
residential water heater test procedure and the benefits and concerns
with using a lower temperature. Three commenters to the October 2011
RFI (Bradford White, Bosch, and General Electric) recommended that the
set point temperature should be kept at its current value of 135 [deg]F
(57 [deg]C). Additionally, two commenters on the January 2013 RFI also
recommended maintaining the set point at 135 [deg]F (57 [deg]C).
(Bradford White, No. 30 at p. 2; AHRI, No. 46 at p. 2) Bosch stated
that this value will maintain harmonization with test standards in
Canada. General Electric indicated that plumbers may change the set
point, but a lower temperature in the test procedure runs the risk of
encouraging consumer dissatisfaction with water heaters that are
otherwise properly sized for their household due not to lack of
capacity, but to lack of properly adjusted storage temperatures.
Additionally, General Electric indicated that DOE runs the risk
[[Page 66219]]
of encouraging energy inefficiency in actual use at higher set points
of water heaters designed and optimized to test procedures at lower set
points. (Bradford White, No. 2 at p. 2; Bosch, No. 17 at p. 2; GE, No.
21 at pp. 2-3) In submitting a suggested test method, AHRI noted that
it considered lower set points but that its recommendation is to
continue to use 135 [deg]F as the set point in the test. AHRI indicated
that its recommended draw patterns should be modified if DOE determines
that a different set point temperature setting is appropriate. (AHRI,
No. 46 at p. 2)
Thirteen comments were submitted that recommended that the set
point temperature be lowered from its current value. PGE, SCE, NREL,
AET, and ACEEE recommended a set point temperature of 120 [deg]F (PGE,
No. 3 at p. 2; SCE, No. 4 at p. 2; NREL, No. 14 at p. 4; AET, No. 22 at
p. 3; ACEEE, No. 24 at p. 4), while NEEA recommended a value of 125
[deg]F. (NEEA, No. 9 at p. 3; NEEA, No. 37 at p. 4) In a comment on the
January 2013 RFI, the joint commenters supported a set point
temperature between 120 [deg]F and 125 [deg]F. (Joint comment, No. 35
at p. 3) Likewise, Stone Mountain Technologies and NRDC recommended a
set point between 120 [deg]F and 125 [deg]F. (Stone Mountain
Technologies, No. 5 at p. 3; NRDC, No. 20 at p. 2) AHRI and AO Smith
did not suggest a specific value, but recommended that the set point
temperature be lowered. (AHRI, No. 12 at p. 2; AO Smith, No. 8 at p 2)
AET commented that the proposed ASHRAE Standard 188, (Standard 188P),
``Prevention of Legionellosis Associated with Building Water Systems,''
and ASHRAE Guideline 12, ``Minimizing the Risk of Legionellosis
Associated with Building Water Systems,'' are re-examining
recommendations for preventing the growth of Legionella. AET stated
that water temperatures in the range of 120 [deg]F are adequate to
prevent Legionella colonies, provided that the water is maintained at a
temperature ``high enough, long enough, and often enough.'' (AET, No.
22 at pp. 11-12)
AET commented that the test procedure should allow for variable
delivery temperatures, because some point-of-use water heaters are
designed to deliver water no hotter than 105 [deg]F (40.6 [deg]C) to
110 [deg]F (43.3 [deg]C). AET argued that no credit should be given to
water delivered at temperatures above the set point temperature, in
order to discourage temperature overshoots. Likewise, AET argued that
no credit should be given to water delivered at a temperature below
that which is considered useful to the user (i.e., below 105 [deg]F
(40.6 [deg]C)). (AET, No. 22 at p. 13)
After carefully considering these comments, DOE proposes to lower
the set point temperature of residential water heaters in the test
procedure to 125 [deg]F. This value was primarily selected based on
data available in DOE's analysis for the April 2010 energy conservation
standards final rule as previously discussed, which found that the
average set point temperature for residential water heaters is 124.2
[deg]F (51.2 [deg]C). Additionally, the recent compilation of field
data across the United States and southern Ontario by LBNL previously
referenced found a median daily outlet water temperature of 122.7
[deg]F (50.4 [deg]C); this value rounded to the nearest 5 [deg]F
increment supports a test set point temperature of 125 [deg]F. This new
value would apply to first-hour rating tests for storage water heaters,
maximum flow rate tests for instantaneous water heaters, and energy
factor tests for all water heaters.
DOE appreciates the comment from AET regarding the new proposed
guidelines for Legionella prevention, and tentatively concludes that a
set point of 125 [deg]F in the test method would not result in safety
concerns related to the growth of Legionella. Further, as discussed
immediately above, DOE notes that water heaters are commonly set to
temperatures in the range of 120 [deg]F to 125 [deg]F even though the
current set point in the test method is 135 [deg]F. DOE does not expect
consumer behavior related to set points to change if the set point is
lowered in the test method.
For first-hour rating tests, DOE proposes that draws would
terminate when the outlet temperature drops 15 [deg]F (8.3 [deg]C) from
its maximum outlet temperature during the draw, as opposed to the drop
of 25 [deg]F (13.9 [deg]C) implemented in the current test procedure.
This change would ensure that water delivered meets the nominal useful
temperature of 110 [deg]F (43.3 [deg]C). DOE acknowledges that the
Canadian test procedure requires testing at 135 [deg]F (57 [deg]C), but
DOE is responsible for developing a water heater test procedure that
reflects and is appropriate for the United States market. In response
to comments indicating that DOE should retain the 135 [deg]F set point
temperature, DOE believes that the test should be conducted at typical
operating temperatures and should not penalize those units optimized
for such typical conditions.
GE commented that the set point temperature should be based upon
the outlet water temperature as opposed to the average stored water
temperature to allow newer technologies to be included in the protocol
and to achieve the goal of being technology-neutral. (GE, No. 36 at p.
2) HTP made a similar assertion that the set point should not be based
on the mean tank temperature, noting that requiring a mean tank
temperature could penalize condensing gas water heaters that rely on
stratification and cooler water at the bottom of the tank to achieve
better heat transfer resulting in the condensation of moisture within
the flue gases. (HTP, No. 41 at p. 2) Due to these concerns, AHRI
suggested an alternative method for setting the thermostat. Instead of
setting the thermostat based on the mean tank temperature as determined
by the internal tank temperature probe, AHRI suggested that the
thermostat setting should be determined by drawing water from the water
heater for several minutes to determine if the set point temperature is
achieved. (AHRI, No. 46 at p. 5) AHRI proposed that the flow rate at
which the water would be drawn during this procedure to set the
thermostat would be 1 gpm for point-of-use water heaters and 1.7 gpm
for all other size storage water heaters.
DOE agrees in principle with the comments and the suggested
approach presented by AHRI for setting the thermostat. After carefully
considering these comments, DOE acknowledges that the current method
for setting the thermostats of water heaters that rely on
stratification may lead to outlet water temperatures significantly
higher than would normally be expected in practice, since the top of
the water heater needs to be at an elevated temperature compared to the
mean temperature to meet the requirement that the mean temperature fall
within the value specified in the test procedure. However, DOE is not
aware of a simple method to assure that multiple thermostats are set
appropriately by monitoring outlet water temperature during a draw.
As a result, DOE proposes a method for determining the appropriate
set point temperature that differs slightly from that proposed by AHRI.
DOE proposes to apply the thermostat setting procedure that utilizes
the outlet temperature during a draw, as suggested by AHRI, only to
water heaters having a single thermostat. For water heaters with
multiple thermostats, DOE proposes to maintain the procedure currently
prescribed in the residential water heater test method which utilizes
the internal tank temperature probes to determine if the water heater
thermostat is set properly. DOE is not aware of any technologies that
rely on stratification that utilize multiple thermostats, so it
believes that the current approach for
[[Page 66220]]
setting the thermostat is appropriate for water heaters having multiple
thermostats. DOE is also proposing to make a clear distinction by rated
volume between those water heaters using a lower flow rate during this
test compared to those using a higher flow rate since the thermostat
setting will need to be done prior to the experimental determination of
whether the water heater is to be considered a point-of-use water
heater. While making this adjustment, DOE is maintaining calculations
to normalize the standby loss to a mean tank temperature of 125 [deg]F
5 [deg]F (51.7[deg]C 2.8 [deg]C) to ensure
equitable comparison between water heaters.
DOE is interested in receiving comments on both the proposed set
point temperature of 125 [deg]F 5 [deg]F, and the proposed
approach to setting the thermostat for storage water heaters,
particularly on the appropriateness of different methods for water
heaters having a single thermostat compared to those with multiple
thermostats. These are identified as issues 6 and 7 in section V.E,
``Issues on Which DOE Seeks Comment.''
2. Ambient Temperature and Relative Humidity
The residential water heater test procedure requires that testing
be performed in an environment with an ambient air temperature fixed at
67.5 [deg]F 2.5 [deg]F (19.7 [deg]C 1.4
[deg]C). 10 CFR part 430, subpart B, appendix E, section 2.2. For heat
pump water heaters, however, the environmental conditions are more
tightly constrained with an ambient air temperature requirement of 67.5
[deg]F 1 [deg]F (19.7 [deg]C 0.6 [deg]C) and
a relative humidity requirement of 50 percent 1 percent.
Id. These specifications for heat pump water heaters reflect the fact
that heat pump water heater energy use is highly dependent on the
ambient temperature and relative humidity. Because water heaters are
placed in a wide variety of locations within and outside of a home, and
given the large impact of these factors on heat pump water heater
efficiency, DOE considered potential revisions to the ambient air test
conditions set forth in the DOE test procedure in order to assess
whether the currently-specified conditions are representative of
conditions typically encountered in residential installations. In the
October 2011 RFI, DOE requested comment on the appropriate ambient
temperature and relative humidity testing points and tolerances for all
types of residential water heaters. 76 FR 63211, 63214-15 (Oct. 12,
2011).
DOE received seven comments (Bradford White, Stone Mountain
Technologies, AO Smith, AHRI, Bosch, General Electric, and AET) that
supported the current ambient temperature and relative humidity
conditions. Bradford White suggested that DOE should consider relaxing
the tolerances for temperature and relative humidity when testing heat
pump water heaters since it is very difficult to control to those
conditions, recommending that the allowable ambient temperature
variation be 2.5 [deg]F and the allowable variation in
relative humidity be 5 percent. (Bradford White, No. 2 at
p. 2; Stone Mountain Technologies, No. 5 at p. 3; AO Smith, No. 8 at p.
2; AHRI, No. 12 at p. 2; Bosch, No. 17 at p. 2; GE, No. 21 at p. 3;
AET, No. 22 at p. 4)
NEEA submitted for DOE consideration as a test method a test plan
that has been implemented in the Pacific Northwest in which heat pump
water heaters are tested at both the current DOE specifications and at
a second point with the ambient temperature at 50 [deg]F (10 [deg]C)
and the relative humidity at 58 percent. A bin-weighted calculation
using these two points would yield an energy factor, and NEEA stated
that it believes that these conditions are more appropriate than the
current ones for installations in the northern half of the United
States and would lead to better estimates of the actual performance in
the field. (NEEA, No. 9 at p. 3) NEEA reiterated the desire to test at
multiple conditions in response to the January 2013 RFI. (NEEA, No. 37
at p. 5) NRDC indicated that the conditions need to be re-examined but
did not offer any suggestions. (NRDC, No. 20 at p. 2) ACEEE suggested
that DOE should evaluate changing the ambient temperature to 50 [deg]F
or other such value that approximates the national average winter
basement temperature. (ACEEE, No. 24 at p. 3) Davis Energy Group
presented data from a survey of homes in California that reported
average ambient temperatures that ranged from 65.4 [deg]F to 71.7
[deg]F. (Davis Energy Group, No. 6 at p. 1)
After carefully considering these comments, DOE proposes to
maintain the current ambient dry bulb temperature of between 65 [deg]F
and 70 [deg]F when testing water heaters other than heat pump water
heaters and at 67.5 [deg]F 1 [deg]F when testing heat pump
water heaters. DOE also proposes to maintain relative humidity at 50
percent, but to relax the tolerances to 2 percent relative
humidity. DOE believes these conditions are generally representative of
typical field conditions encountered by water heaters installed in the
U.S. and has not found any data to justify changing these conditions.
DOE proposes to relax the tolerance for relative humidity because
research indicates that commonly-used, laboratory-grade relative
humidity sensors have uncertainties on the order of 1 to 1.5 percent.
For this reason, the tolerance cannot be expected to be below the
accuracy in measuring that value. It should be noted, however, that the
relative humidity can be obtained from measurements of dry bulb and wet
bulb temperatures, and the determination of relative humidity through
these temperature measurements would result in a measure of relative
humidity with much lower uncertainty since dry bulb and wet bulb
temperatures can be measured with high accuracy. However, most
laboratories use relative humidity sensors which provide an accurate
but less burdensome method for measuring relative humidity. DOE is also
proposing to add a statement to the instrumentation section that
specifies that the accuracy of relative humidity sensors shall be
within 1.5 percent relative humidity.
3. Laboratory Airflow
The existing test procedure specifies that the water heater shall
be set up in an area that is protected from drafts. To clarify this
statement, DOE proposes to add a stipulation that the area be protected
from drafts of more than 50 ft/ min (2.5 m/s). This value is in
accordance with specifications in Canadian Standard 745-03, ``Energy
Efficiency of Electric Storage Tank Water Heaters and Heat Pump Water
Heaters.''
G. Annual Energy Consumption Calculation
The annual energy consumption is calculated for residential water
heaters in the existing test procedure based on the daily energy
consumption multiplied by 365 days. In a letter submitted to the FTC on
September 16, 2013, regarding the labeling of residential water
heaters, AHRI pointed out that calculating the annual energy
consumption based on the daily energy consumption can lead to differing
annual energy consumption, and consequently, differing estimated yearly
operating costs, for water heater models with the exact same EF rating.
AHRI specifically provided an example of two water heaters with
differing daily energy consumption values, but with EF values that
would round to the same value based on the DOE rounding requirements
provided in 10 CFR 430.23(e). AHRI stated that having slightly
different yearly operating cost
[[Page 66221]]
estimates for two water heaters with the same efficiency rating can be
confusing to consumers, and somewhat misleading based on the accuracy
of the test method. AHRI suggested revising the calculation of the
annual energy consumption so that it is based on the EF rating.
DOE agrees with AHRI regarding the calculation of the annual energy
consumption and the accuracy of the test method. As a result, DOE
proposes to adopt the calculation method suggested by AHRI for annual
energy consumption, which is based on the nominal energy consumed
during the test and the energy factor rating, rather than the daily
energy consumption.
H. Conversion of Existing Energy Factor Ratings
The proposed test procedure amendments could result in some types
of water heaters reporting some numerical changes in EF due to the
proposed changes in the draw pattern, set point temperature, and water
delivery temperature. However, the extent of change can vary across the
numerous design types of water heaters and, perhaps more importantly,
within a given design type. This variability makes it difficult to
capture the effect of the proposed test procedure amendments by a
consistent, systematic adjustment to the current test procedure.
Foreseeing these circumstances, AEMTCA amended EPCA to require that
along with the uniform descriptor, DOE must develop a mathematical
conversion factor to translate from the existing metrics to the uniform
descriptor. (42 U.S.C. 6295(e)(5)(E)) AEMTCA provided that a
manufacturer may apply the conversion factor to rerate existing models
of covered water heaters that are in existence prior to the effective
date of the final rule establishing the uniform descriptor. Further,
the conversion factor must not affect the minimum efficiency
requirements for covered water heaters, and, as a result, would not
lead to a change in measured energy efficiency for existing products.
DOE interprets these requirements to mean that DOE will be required to
translate existing ratings from the current metrics to the new metric,
while maintaining the stringency of the current standards. In the
January 2013 RFI, DOE sought comment on the best approach for this
conversion factor. 78 FR 2340, 2345 (Jan. 11, 2013).
NREL stated that there is not a simple conversion factor that will
work across all systems, but it provided a list of references with
validated algorithms that could assist DOE in developing these
conversion factors. (NREL, No. 29 at p. 4) AHRI and AO Smith commented
that DOE should not simply test multiple units to determine an average
difference between the current and new ratings and use that value to
convert the ratings. (AHRI, No. 33 at p. 4; AO Smith, No. 34 at p. 3)
The joint commenters supported the use of a ``good-enough''
mathematical conversion method to express existing ratings in terms of
the new uniform descriptor and urged DOE to test a sample of existing
products to validate the algorithmic conversion method. (Joint comment,
No. 35 at p. 4) Considering the limited laboratory capacity to test all
water heaters under the revised method of test, NEEA commented that DOE
should assume that all water heaters that comply with current standards
will also comply after the implementation of the new metrics. (NEEA,
No. 37 at p. 6) EEI commented that the conversion factor should not
make currently existing standards more stringent and should only be
based on point-of-use metrics to be consistent with Federal law. (EEI,
No. 40 at p. 2) HTP commented that the most exact approach would be to
conduct an empirical analysis using curve fitting to actual test data,
although the commenter acknowledged that there is not sufficient time
for manufacturers to obtain this information and for the Department to
then correlate and analyze the data. (HTP, No. 41 at p. 3)
DOE notes these comments regarding the conversion factor and will
consider them fully once the test procedure is finalized to assist in
developing the conversion factor. DOE plans to conduct a separate
rulemaking to establish the conversion factor once the test method is
finalized, and in that rulemaking, DOE will establish a mathematical
method for determining the rated efficiency under the new efficiency
descriptor from the rated efficiency under the existing metrics. Should
it become apparent in the rulemaking to establish the conversion factor
that changes may be required in the test procedure, DOE would address
any issues at that time. DOE also plans to translate its current energy
conservation standards to equivalent standards denominated in the new
uniform efficiency metric in the separate rulemaking.
I. Other Issues
DOE also sought comments in the October 2011 RFI and the January
2013 RFI on any other relevant issues that commenters believe could
affect the test procedure for water heaters, and continues to seek
comment in today's notice. 76 FR 63211, 63215 (Oct. 12, 2011); 78 FR
2340, 2346 (Jan. 11, 2013). Although DOE has attempted to identify
those portions of the test procedure where it believes amendments may
be warranted, interested parties are welcome to provide comments on any
aspect of the test procedure, including updates of referenced
standards, as part of this comprehensive 7-year-review rulemaking.
AET supported keeping the inlet water temperature at 58 [deg]F.
(AET, No. 22 at p. 4) Davis Energy Group provided data on average inlet
water temperatures reported in studies in California that ranged from
64.2 [deg]F to 72.3 [deg]F. (Davis Energy Group, No. 6 at p. 3) Despite
these values being higher than the current nominal temperature
specified in the current DOE test procedure, DOE has not seen any data
that suggests a different temperature is more appropriate on a national
basis, so DOE has tentatively decided to maintain the inlet temperature
at 58[emsp14][deg]F in the proposed test procedure.
AHRI suggested an alternative means to prepare a storage-type water
heater prior to commencement of the 24-hour simulated-use test. (AHRI,
No. 46 at p. 7) AHRI suggested that DOE could improve the consistency
of energy factor tests by running the draw patterns on two consecutive
days, with measurements only taking place during the second 24-hour
period. After careful consideration, DOE has tentatively concluded that
this approach would lead to more consistent results since the state of
the water heater at the beginning of the 24-hour test period will be
similar to that at the end of the test period, thereby minimizing the
need to make large corrections to the energy consumption values which
could introduce errors. DOE is aware of testing conducted in this
manner that has resulted in consistent values for the energy
factor.\20\ DOE is tentatively proposing to require storage water
heaters to be pre-conditioned in this manner. It is DOE's understanding
that test laboratories must already let the water heater sit at
temperature for an extended period of time to let the unit achieve
operational temperature. Therefore, DOE reasons that the proposed pre-
conditioning routine might be done during this stage, thereby resulting
in little or no added test time. DOE is interested in comment regarding
the value of the pre-conditioning period and the incremental burden, if
any, that
[[Page 66222]]
it would place on manufacturers. This is identified as issue 5 in
section V.E, ``Issues on Which DOE Seeks Comment.''
---------------------------------------------------------------------------
\20\ Healy WM,, Lutz JD, and Lekov AB., ``Variability in Energy
Factor Test Results for Residential Electric Water Heaters,'' HVAC&R
Research, vol. 9, No. 4 (October 2003).
---------------------------------------------------------------------------
NREL argued that published metrics from the DOE test procedure
should allow for calculation of performance under conditions outside
the particular conditions imposed by the test procedure. (NREL, No. 29
at p. 1) DOE does not propose to require any published metrics from the
test procedure specifically for the purpose of calculating performance
at various conditions outside of those imposed by the test method, as
the purpose of the DOE test procedure is to determine compliance to
minimum efficiency standards and to provide a basis for representation
of energy performance to consumers.
The joint comment urged DOE to consider several additional points.
(Joint comment, No. 35 at p. 6) First, it raised the question as to the
appropriate rating method for a hybrid solar water heating system whose
tank might be passive or active. DOE notes that solar water heaters are
not covered equipment under EPCA, and thus the DOE test method for
water heaters need not address these systems. Further, hybrid solar
water heating systems consisting of a stand-alone water heater with
additional solar components that are added in the field could be tested
according to the rating method provided for the water heater if the
solar components were not present. The stand-alone heater would be
subject to energy conservation standards without consideration of the
benefits, if any, of the solar portion. Second, the joint commenters
questioned how to rate ``hybrid'' fuel-fired units with tanks larger
than 2 gallons. DOE believes that amendments proposed in this NOPR will
cover those products--the storage volume gaps that currently exist in
the scope would be removed under this proposal, and the proposed test
method would cover those products. Lastly, the joint commenters asked
whether test procedures should reflect energy savings from ``smart'' or
``grid-interactive'' water heaters. DOE does not believe that a
separate test procedure is warranted for this equipment, because they
are functionally similar to non-grid-interactive water heaters. DOE
acknowledges that usage patterns for grid-interactive water heaters may
be very different from water heaters that are not grid-interactive or
controlled as part of demand response programs. However, DOE believes
that there is generally a wide range of usage patterns for all water
heating products seen in the field, and it would be impractical to
attempt to tailor the test method to every potential usage pattern.
Thus, DOE believes that such differences in usage patterns are better
addressed as part of standards analyses, rather than as a separate test
method.
PGE commented that a method is needed for reporting source energy
consumption for future standards rulemakings, because the commenter
opined that source energy is a more complete metric for representing
the energy consumed by appliances and would yield a better comparison
between the energy consumption of gas, electric, and gas/electric
units. The commenter further opined that the test procedures should
include calculations to allow for two energy factors, one based on site
energy and one based on source energy. (PGE, No. 3 at p. 2) In response
to the January 2013 RFI, DOE received additional comments related to
source-based metrics. EEI stated that, consistent with other Federal
laws, any new descriptor or conversion factor should only be based on
point-of-use metrics. (EEI, No. 40 at p. 2) AGA, NPGA, and APGA all
supported a metric based on the full fuel cycle that would provide a
complete accounting of energy consumption from extraction, processing,
and transportation of energy. (AGA, No. 31, at p. 3; NPGA, No. 32 at p.
1; APGA, No. 39 at p. 1)
In addressing this comment, DOE notes that the Department has
historically presented national energy savings (NES) in terms of
primary energy savings (i.e., source energy savings). However, in
response to the recommendations of a committee on ``Point-of-Use and
Full-Fuel-Cycle Measurement Approaches to Energy Efficiency Standards''
appointed by the National Academy of Science, DOE announced its
intention to use full-fuel-cycle (FFC) measures of energy use and
greenhouse gas and other emissions in the national impact analyses and
emissions analyses included in future energy conservation standards
rulemakings. 76 FR 51281(August 18, 2011). To this end, DOE has begun
to also estimate energy savings using the FFC metric. The FFC metric
includes the energy consumed in extracting, processing, and
transporting primary fuels, and thus presents a more complete picture
of the impacts of efficiency standards. DOE's approach is based on
application of FFC multipliers for each fuel type used by covered
products and equipment, as presented in DOE's statement of policy
published in the Federal Register on August 18, 2011. Id.
DOE has reviewed the water heater test procedures, including
today's proposed amendments, in relation to the newly established FFC
policy, and has tentatively concluded that no substantive amendments
are needed to the water heater test procedures to accommodate the FFC
policy. In support of this conclusion, the following discussion
elaborates separately on the FFC policy implications for energy
efficiency standards and representations.
For the purposes of energy conservation standards, the test
procedure-derived measure of energy consumption and efficiency,
including the regulatory efficiency metric (i.e., EF) is sufficient and
complete enough to allow for full consideration of the FFC impacts in
the energy conservation standards analysis. In support of this
conclusion, it is noted that the existing and future energy
conservation standards for these products are, and are expected to
continue to be, analyzed independently by fuel type. DOE believes this
independent analytical approach eliminates any possible
mischaracterization or inappropriate consideration of a standard's
stringency that might be associated with the test procedure's
regulatory metrics for these products. More specifically, the
commenters' suggestion to add a source-based Energy Factor for water
heaters would not add to or improve the standards analysis for water
heaters because of the expansion of the standard's analysis already
incorporated in the current approach.
For the purposes of representations, DOE has also tentatively
concluded that some small improvements to the water heater test
procedure are deemed appropriate to accommodate the FFC policy. It is
important to note that both the current test procedure and the proposed
revised test method for this product incorporate numerous measures of
energy consumption and efficiency, some of which are used in the
regulatory context mentioned above and some of which support the
consumer information objective of the test procedure. Although the main
thrust of the PGE, AGA, APGA, and NPGA suggestions seems to be based on
the assumption that the addition of a source-based energy factor would
improve analysis for water heater standards, there also seems to be a
suggestion that such inclusion would also provide improvement in a non-
regulatory or consumer information context. An important example of a
non-regulatory metric is annual energy consumption, which provides a
complete accounting of the energy consumption to the consumer and which
can be used to estimate annual
[[Page 66223]]
operating cost. For water heaters, DOE proposes to add terms in the
test method to quantify daily electric energy consumption separately
from fossil fuel energy consumption and to add separate estimates of
annual fossil fuel energy consumption and annual electrical energy
consumption in addition to the overall annual energy consumption. This
separation would allow the user of the test procedure to estimate
operational cost of water heaters that use both fossil fuel and
electricity based on the prices of those different energy sources. From
a consumer's perspective, annual operating cost is particularly useful
for the products that have dual fuel inputs. DOE believes this consumer
cost perspective is reasonably reflected in the FFC (i.e., the source/
site factors recommended by the commenter are essentially numerically
identical to the fuel cost ratios published biennially by the
Secretary). Therefore, the commenters' suggested addition of a source-
based energy factor using the suggested multipliers is, in DOE's view,
not likely to convey any improvement in product-to-product comparisons
relative to annual operating cost. In fact, annual operating cost would
likely be a superior basis of comparison for consumers, considering the
familiarity with annual budgets and the lack of familiarity with
source-based efficiency comparisons.
In addition, and perhaps more importantly, annual operating cost
provides a reasonable comparison across competing product types
utilizing different fuels (e.g., electric water heaters and gas-fueled
water heaters). Arguably, site-based energy factors for electric water
heaters (typically approximately 0.9 for an electric resistance model)
would be higher than the counterpart energy factors for gas water
heaters (typically approximately 0.6), but not representative of the
relative efficiency of each type of water heater. Thus, an
inappropriate conclusion would be conveyed to consumers. DOE believes
such inappropriate conclusions can be easily avoided in any consumer
information program by focusing on annual operating cost. Here again,
the biennial published unit cost of energy would protect the consumer
from inappropriate conclusions. Accordingly, for purposes of
representations, DOE is not aware, nor has it been made aware through
responses to the request for information, of any specific problems,
shortcomings, or misrepresentations resulting from the existing test
procedure measures of energy consumption and efficiency as it relates
to the FFC policy. The proposed amendments to the water heater test
procedure would provide additional metrics that could be used should
one desire more information related to the FFC policy for a particular
application of the test method.
DOE is interested in receiving comment on adding terms to quantify
daily electric energy consumption separately from fossil fuel energy
consumption and adding separate estimates of annual fossil fuel energy
consumption and annual electrical energy consumption in addition to the
overall annual energy consumption. This is identified as issue 8 in
section V.E, ``Issues on Which DOE Seeks Comment.''
A final issue raised by commenters is that heat pump water heaters
that have recently entered the market typically have multiple
operational modes, and the current DOE test procedure does not specify
which mode should be used when the unit is undergoing testing. AO Smith
and AHRI commented that all heat pump water heaters should be tested
under a single mode of operation which is the default or ``out-of-the-
box'' condition. (AO Smith, No. 8 at p. 2; AHRI No. 12 at p. 3) DOE
agrees with this comment and proposes a clarification to the test
procedure to indicate that heat pump water heaters are to be tested in
the default mode when obtaining both the first-hour rating and
determining the energy factor. This clarification is consistent with
guidance issued by DOE on June 12, 2012 (see: https://www1.eere.energy.gov/guidance/detail_search.aspx?IDQuestion=623&pid=2&spid=1).
J. Certification, Compliance, and Enforcement Issues
In this notice of proposed rulemaking, DOE proposes to make several
changes to its certification, compliance, and enforcement regulations
at 10 CFR Part 429. First, DOE proposes to add requirements to 10 CFR
429.17 that the rated value of storage tank volume must equal the mean
of the measured storage volume of the units in the sample. DOE notes
that there are currently no requirements from the Department limiting
the amount of difference that is allowable between the tested (i.e.,
measured) storage volume and the ``rated'' storage volume that is
specified by the manufacturer. DOE has tested 65 residential storage-
type water heaters, including 44 gas-fired water heaters, 19 electric
water heaters, and 2 oil-fired water heaters. Through this testing, DOE
has found that water heaters are consistently rated at storage volumes
above their actual storage volume. For gas fired water heaters, the
rated volume ranged from 1.5 to 15.6 percent above the measured volume,
with the mean being 4.8 percent. For electric water heaters, the rated
volume ranged from 5.0 to 10.6 percent above the measured volume, with
the mean being 9.4 percent. DOE notes that its minimum energy
conservation standards are based on the rated storage volume and
decrease as rated storage volume increases. DOE also believes consumers
often look to storage volume as a key factor in choosing a storage
water heater. Consequently, DOE proposes to adopt rating requirements
that the rated value must be the mean of the measured value. In
addition, DOE proposes to specify that for DOE-initiated testing, a
tested value within five percent of the rated value would be a valid
test result where the rated storage volume would then be used in
downstream calculations. If the test result of the volume is invalid
(i.e., the measured value is more than five percent different than the
rated value), then DOE proposes to use the measured value in
determining the applicable minimum energy conservation standard and
calculations within the test procedure. DOE proposes to specify similar
requirements for light commercial water heaters.
Additionally, because the first-hour and maximum gpm ratings will
determine the applicable draw pattern for use during the energy factor
test, DOE proposes to include rating requirements for those values. DOE
proposes that the rated first-hour rating or maximum gpm rating, as
applicable, must be the mean of the measured values of the sample used
for certifying the basic model's efficiency rating. For DOE testing,
the rating will be considered valid if it is within five percent of the
certified rating. In such a case, DOE proposes that the rated value
would be used for the purposes of choosing the appropriate draw pattern
for the energy factor test. In the case of an invalid rating (i.e., the
rated first-hour rating or maximum gpm rating is more than five percent
different from the measured value), DOE proposes to use the measured
value to determine the applicable draw pattern for the energy factor
test.
DOE has further considered section 7.0 of the current test
procedure, ``Ratings for Untested Models,'' and believes that this
information is more appropriately addressed in the 10 CFR part 429,
which deals with requirements for certification of residential water
heaters. DOE proposes to remove this section from Appendix E and place
a similar section in 10 CFR 429.17. DOE
[[Page 66224]]
proposes to maintain the requirements for gas water heaters, which
allow units using propane gas that have an input rating within 10
percent of an identical natural gas unit to use the rating for the
natural gas unit in lieu of separate testing. However, DOE proposes to
eliminate the provisions for electric water heaters that currently
allow a manufacturer of electric water heaters that are identical
except with different input ratings to designate a standard input
rating at which to test the water heater.
Under the current procedure, the manufacturer of electric water
heaters may designate the standard input rating that would apply to all
models that are identical with the exception of the power input to the
heating element and test only at single input rating. It provides
instructions for specifying the first-hour rating of units with higher
and lower input ratings than the standard rating. The procedure also
provides that the energy factor can be assumed to be the same across
all input ratings. DOE proposes to remove these provisions due to the
proposed revisions in the test method for the first-hour rating and
energy factor tests. The first-hour rating would be expected to vary
based on the power input to the electric heating element, and under the
revisions proposed in this test method the applicable draw pattern for
the energy factor test would be based on the first-hour rating. As a
result, it is important that the first-hour rating is accurate for the
given model as it will potentially impact the draw pattern and the
resultant EF rating.
K. Reference Standards
DOE's test procedure for residential water heaters currently
references two industry standards: American Society for Testing and
Measurement (ASTM) D2156-80, ``Smoke Density in Flue Gases from Burning
Distillate Fuels, Test Method for'' and ASHRAE Standard 41.1-1986,
``Standard Measurement Guide: Section on Temperature Measurements.''
DOE proposes to maintain these references in the uniform efficiency
descriptor test method, but to update the reference standards to the
most recent versions of the industry standards: ASTM D2156-09,
``Standard Test Method for Smoke Density in Flue Gases from Burning
Distillate Fuels'' and ASHRAE Standard 41.1-1986 (RA2006), ``Standard
Method for Temperature Measurement.'' DOE has reviewed both of the
updated standards and has tentatively concluded that their adoption
would not substantially impact the test method.
L. Compliance With Other EPCA Requirements
As mentioned above, in amending a test procedure, EPCA directs DOE
to determine to what extent, if any, the test procedure would alter the
measured energy efficiency or measured energy use of a covered product.
(42 U.S.C. 6293(e)(1)) If the amended test procedure alters the
measured energy efficiency or measured energy use, the Secretary must
amend the applicable energy conservation standard to the extent the
amended test procedure changes the energy efficiency of products that
minimally comply with the existing standard. (42 U.S.C. 6293(e)(2)) The
current energy conservation standards for residential water heaters are
based on energy factor (EF), and the energy conservation standards for
commercial water heaters are based on thermal efficiency and standby
loss. DOE believes that the conversion factor (or factors) required by
AEMTCA (as discussed in section III.G) will ensure that there is no
change in measured energy efficiency.
Consistent with 42 U.S.C. 6293(c), DOE typically requires that any
representations of energy consumption of covered products must be based
on any final amended test procedures 180 days after the publication of
the test procedure final rule. However, in this instance, the statute
specifically provides for an effective date of the test procedure final
rule which is one year after the date of the publication of the final
rule. (42 U.S.C. 6295(e)(5)(D)(ii)) In addition, AEMTCA provides for
the use of a conversion factor that will apply beginning on the date of
publication of the conversion factor in the Federal Register and ending
on the later of 1 year after the date of publication of the conversion
factor or December 31, 2015. (42 U.S.C. 6295(e)(5)(E)(v)) Thus, one
year after the publication of the test procedure final rule, it will
become effective, and manufacturers may at their discretion make
representations of energy efficiency based either (a) on the final
amended test procedures or (b) on the previous test procedures after
applying the conversion factor. The previous test procedures for
residential water heaters are set forth at 10 CFR part 430, subpart B,
appendix E as contained in 10 CFR parts 200 to 499 edition revised as
of January 1, 2013. The previous test procedures for commercial water
heating equipment are set forth at 10 CFR 431.106 as contained in 10
CFR parts 200 to 499 edition revised as of January 1, 2013. As required
by AEMTCA, the conversion factor may be used until the later of one
year after the publication of the factor, or December 31, 2015, after
which time all testing must be conducted in accordance with the new
amended test procedure. DOE notes that during the interim period
manufacturers must use the same test procedure for representations of
energy efficiency, including certifications of compliance.
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
The Office of Management and Budget 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
regulatory action was not subject to review under the Executive Order
by the Office of Information and Regulatory Affairs (OIRA) in the
Office of Management and Budget (OMB).
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq., as amended by
the Small Business Regulatory Enforcement Fairness Act of 1996)
requires preparation of an initial regulatory flexibility analysis
(IFRA) for any rule that by law must be proposed for public comment and
a final regulatory flexibility analysis (FRFA) for any such rule that
an agency adopts as a final rule, unless the agency certifies that the
rule, if promulgated, will not have a significant economic impact on a
substantial number of small entities. A regulatory flexibility analysis
examines the impact of the rule on small entities and considers
alternative ways of reducing negative effects. Also, 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 at: www.gc.doe.gov/gc/office-general-counsel.
Today's proposed rule would prescribe test procedure amendments
that would be used to determine compliance with energy conservation
standards for residential water heaters and certain commercial water
heaters. For residential water heaters and certain commercial water
heaters, the proposed amendments would establish a uniform
[[Page 66225]]
efficiency descriptor which would be more representative of conditions
encountered in the field (including modifications to both the test
conditions and the draw patterns), and expand the scope of the test
procedure to apply to certain residential water heaters and certain
commercial water heaters that are currently not covered by the test
procedure. DOE reviewed today's 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, 30848-49 (May 15, 2000), as
amended at 65 FR 53533, 53544-45 (Sept. 5, 2000) 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/idc/groups/public/documents/sba_homepage/serv_sstd_tablepdf.pdf. Residential water heater
manufacturing is classified under NAICS 335228--``Other Major Household
Appliance Manufacturing.'' The SBA sets a threshold of 500 employees or
less for an entity to be considered as a small business. Commercial
water heaters are classified under NAICS 333319 -``Other Commercial and
Service Industry Machinery Manufacturing,'' for which SBA also sets a
size threshold of 500 employees or fewer for being considered a small
business.
DOE has identified 13 manufacturers of residential water heaters
(including manufacturers of products that fall under the proposed
expanded scope) that can be considered small businesses. DOE identified
nine manufacturers of ``light commercial'' water heaters that can be
considered small businesses. Seven of the ``light commercial'' water
heater manufacturers also manufacture residential water heaters, so the
total number of water heater manufacturers impacted by this rule would
be 15. DOE's research involved reviewing several industry trade
association membership directories (e.g., AHRI), product databases
(e.g., AHRI, CEC, and ENERGY STAR databases), individual company Web
sites, and marketing research tools (e.g., Hoovers reports) to create a
list of all domestic small business manufacturers of products covered
by this rulemaking.
For the reasons explained below, DOE has tentatively 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 residential water heaters, the amendments proposed in today's
notice of proposed rulemaking apply primarily to the draw pattern and
water delivery temperature. Under DOE's existing test procedure,
manufacturers must perform a simulated use test consisting of 6 draws
of equal lengths with a water heater delivery temperature of 135
[deg]F. If adopted, today's proposal would require manufacturers to
perform a simulated use test consisting of 9 to 14 draws of varied
length, depending on the capacity of the water heater, at a water
delivery temperature of 125 [deg]F. The change in water delivery
temperature requires no additional effort or expense for the
manufacturer, because establishing the test temperature is simply a
matter of choosing the appropriate setting on the water heater.
Likewise, the change in the number of draws would also result in very
little burden on manufacturers. The length and timing of draws for the
existing test procedure are largely controlled automatically by
computer control. The proposed changes would result in manufacturers
having to reprogram the computer test programs to account for the new
draw patterns. DOE estimates that this effort would take approximately
one week to program and confirm operation of the amended test. It is
estimated that approximately two days of a programmer's time would be
needed at a cost of $1,000 including overhead and benefits. This one-
time cost is comparable to that charged by a third-party test
laboratory for a single test, so it is not considered burdensome for
water heater manufacturers. Since the simulated use test takes 24 hours
under both the existing and proposed test method, the length of the
test would not change. The current proposal does specify a 24-hour pre-
conditioning period prior to the 24-hour test for storage water
heaters, however, which would add to the time required to conduct the
test. This extra test time would not require extra personnel, but it
may necessitate the development of additional test platforms to
accommodate the amount of testing that a manufacturer must conduct. A
duplicate test platform, if necessary, could result in an additional
cost of approximately $5,000 in terms of materials and time needed for
construction. DOE understands, however, that a 24-hour pre-conditioning
period is already implemented by manufacturers as a best practice to
allow the water heater to achieve operational temperature, so the added
burden would be minimal. In addition, these tests can be conducted in
the same facilities used for the current energy testing of these
products, so there would be no additional facility costs required by
the proposed rule.
Lastly, the only potential instrumentation upgrade required to
conduct the test would be electric power and energy measuring equipment
that meets the accuracy levels that have changed from 1
percent to 0.5 percent. DOE believes that equipment
meeting these tolerances is already the industry standard. Purchase of
a new instrument, if needed, would be expected to cost approximately
$1,000.
For certain commercial water heaters included in the scope of this
rulemaking, the efficiency test required for equipment would change
from the thermal efficiency and standby loss tests specified in the
current DOE test method, to the simulated use test for energy factor
proposed in today's NOPR. The energy factor test is inherently more
complex than the thermal efficiency and standby loss tests, and, thus,
it may be more difficult to implement. However, the standby loss test
takes a significant amount of time, which is comparable to the 24-hour
simulated use test. Accordingly, overall testing time should remain
fairly constant. DOE understands that the complexity of the energy
factor test would impose additional costs on manufacturers due to the
need to automate draw patterns, as compared to the thermal efficiency
test. In addition, some hardware purchases may be needed to allow for
computer-controlled draws of hot water that are required in a simulated
use test. However, DOE notes that many commercial water heater
manufacturers also manufacture residential water heaters, and may
already have this equipment from testing of residential units.
Nonetheless, DOE estimates that this hardware could cost approximately
$1,000, assuming that the laboratory already has a computer-controlled
data acquisition system to collect data during the thermal efficiency
and standby loss tests currently required. DOE estimates the costs for
a programmer to create a computer program that automatically controls
the hot water draws would be similar to the costs above, but that the
time required may be slightly longer if the program is being developed
from scratch. Under such circumstances, DOE estimates that 5 days of
programmer
[[Page 66226]]
time would be needed for a cost of $2,500, including overhead and
benefits.
Lastly, DOE considered the impacts on small businesses that
manufacture residential water heaters that fall into categories that
were previously not covered by the DOE residential water heater test
procedure (e.g., models with storage volumes between 2 and 20 gallons).
In reviewing the market for these products, DOE did not identify any
manufacturers that did not also manufacture other types of water
heating equipment. Thus, DOE believes that these manufacturers would
already have the needed equipment and computer programs to conduct the
current DOE test. For the reasons stated previously, DOE does not
believe the proposed updates will cause significant additional burdens
for these manufacturers.
Accordingly, DOE tentatively concludes and certifies that this
proposed rule would not have a significant economic impact on a
substantial number of small entities, so DOE has not prepared a
regulatory flexibility analysis for this rulemaking. DOE will provide
its certification and supporting statement of factual basis to the
Chief Counsel for Advocacy of the SBA for review under 5 U.S.C. 605(b).
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of water heaters must certify to DOE that their
products comply with all applicable energy conservation standards. In
certifying compliance, manufacturers must test their products according
to the DOE test procedure for water heaters, including any amendments
adopted for the test procedure on the date that compliance is required.
DOE has established regulations for the certification and recordkeeping
requirements for all covered consumer products and commercial
equipment, including residential and commercial water heaters. (76 FR
12422 (March 7, 2011). The collection-of-information requirement for
certification and recordkeeping is subject to review and approval by
OMB under the Paperwork Reduction Act (PRA). This requirement has been
approved by OMB under OMB control number 1910-1400. Public reporting
burden for the certification is estimated to average 20 hours per
response, including the time for reviewing instructions, searching
existing data sources, gathering and maintaining the data needed, and
completing and reviewing the collection of information.
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
D. Review Under the National Environmental Policy Act of 1969
In this proposed rule, DOE proposes test procedure amendments that
it expects will be used to develop and implement future energy
conservation standards for residential and commercial water heaters.
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 test procedures 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 Federal 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 tentatively 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 today's
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 tentatively 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 regulatory actions likely to result in a rule that may cause the
expenditure by
[[Page 66227]]
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 ``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 www.gc.doe.gov/gc/office-general-counsel.) DOE
examined today's proposed rule according to UMRA and its statement of
policy and has tentatively determined that the rule contains neither an
intergovernmental mandate, nor a mandate that may result in the
expenditure by State, local, and Tribal governments, in the aggregate,
or by the private sector, of $100 million or more in any year.
Accordingly, no further assessment or analysis is required under UMRA.
H. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family
Policymaking Assessment for any rule that may affect family well-being.
This rule would not have any impact on the autonomy or integrity of the
family as an institution. Accordingly, DOE has concluded that it is not
necessary to prepare a Family Policymaking Assessment.
I. Review Under Executive Order 12630
Pursuant to Executive Order 12630, ``Governmental Actions and
Interference with Constitutionally Protected Property Rights,'' 53 FR
8859 (March 18, 1988), DOE has determined that this proposed rule 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 Federal agencies to review
most disseminations of information to the public under information
quality guidelines established by each agency pursuant to general
guidelines issued by OMB. OMB's guidelines were published at 67 FR 8452
(Feb. 22, 2002), and DOE's guidelines were published at 67 FR 62446
(Oct. 7, 2002). DOE has reviewed today's 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 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.
Today's regulatory action to amend the test procedures for
measuring the energy efficiency of residential water heaters and
certain commercial water heaters is not a significant regulatory action
under Executive Order 12866 or any successor order. Moreover, it would
not have a significant adverse effect on the supply, distribution, or
use of energy, nor has it been designated as a significant energy
action by the Administrator of OIRA. Therefore, it is not a significant
energy action, and, accordingly, DOE has not prepared a Statement of
Energy Effects for this rulemaking.
L. Review Under Section 32 of the Federal Energy Administration Act of
1974
Under section 301 of the Department of Energy Organization Act
(Pub. L. 95-91; 42 U.S.C. 7101 et seq.), DOE must comply with all laws
applicable to the former Federal Energy Administration, including
section 32 of the Federal Energy Administration Act of 1974 (Pub. L.
93-275), as amended by the Federal Energy Administration Authorization
Act of 1977 (Pub. L. 95-70). (15 U.S.C. 788; FEAA) Section 32
essentially provides in relevant part 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.
Today's proposed rule would incorporate testing methods contained
in the following commercial standards: (1) ASTM D2156-09, ``Standard
Test Method for Smoke Density in Flue Gases from Burning Distillate
Fuels''; and (2) ASHRAE Standard 41.1-1986 (RA 2006), ``Standard Method
for Temperature Measurement.'' While today's proposed test procedure is
not exclusively based on these standards, components of the test
procedures are adopted directly from these standards without amendment.
The Department has evaluated these standards and is unable to conclude
whether they fully comply with the requirements of section 32(b) of the
FEAA, (i.e., that they were developed in a manner that fully provides
for public participation, comment, and review). DOE will consult with
the Attorney General and the Chairman of the FTC concerning the impact
on competition of requiring manufacturers to use the test methods
contained in these standards prior to prescribing a final rule.
V. Public Participation
A. Attendance at the Public Meeting
The time, date and location of the public meeting are listed in the
DATES and ADDRESSES sections at the beginning of this document. If you
plan to attend the public meeting, please notify Ms. Brenda Edwards at
(202) 586-2945 or Brenda.Edwards@ee.doe.gov. As explained in the
ADDRESSES section, foreign nationals visiting DOE Headquarters are
subject to advance security screening procedures. Any foreign national
wishing to participate in the meeting should advise DOE of this fact as
soon as possible by contacting Ms. Brenda Edwards to initiate the
necessary procedures.
In addition, you can attend the public meeting via webinar. Webinar
registration information, participant instructions, and information
about the capabilities available to webinar
[[Page 66228]]
participants will be published on DOE's Web site at: https://www1.eere.energy.gov/buildings/appliance_ standards/
rulemaking.aspx?ruleid=82. Participants are responsible for ensuring
their systems are compatible with the webinar software.
B. Procedure for Submitting Requests To Speak and Prepared General
Statements for Distribution
Any person who has an interest in the topics addressed in this
notice, or who is representative of a group or class of persons that
has an interest in these issues, may request an opportunity to make an
oral presentation at the public meeting. Such persons may hand-deliver
requests to speak to the address shown in the ADDRESSES section at the
beginning of this notice of proposed rulemakiing between 9:00 a.m. and
4:00 p.m., Monday through Friday, except Federal holidays. Requests may
also be sent by mail or email to Ms. Brenda Edwards, U.S. Department of
Energy, Building Technologies Office, Mailstop EE-2J, 1000 Independence
Avenue SW., Washington, DC 20585-0121, or Brenda.Edwards@ee.doe.gov.
Persons who wish to speak should include in their request a computer
diskette or CD-ROM in WordPerfect, Microsoft Word, PDF, or text (ASCII)
file format that briefly describes the nature of their interest in this
rulemaking and the topics they wish to discuss. Such persons should
also provide a daytime telephone number where they can be reached.
DOE requests persons selected to make an oral presentation to
submit an advance copy of their statements at least one week before the
public meeting. DOE may permit persons who cannot supply an advance
copy of their statement to participate, if those persons have made
advance alternative arrangements with the Building Technologies Office.
As necessary, requests to give an oral presentation should ask for such
alternative arrangements.
Any person who has plans to present a prepared general statement
may request that copies of his or her statement be made available at
the public meeting. Such persons may submit requests, along with an
advance electronic copy of their statement in PDF (preferred),
Microsoft Word or Excel, WordPerfect, or text (ASCII) file format, to
the appropriate address shown in the ADDRESSES section at the beginning
of this notice of proposed rulemaking. The request and advance copy of
statements must be received at least one week before the public meeting
and may be emailed, hand-delivered, or sent by mail. DOE prefers to
receive requests and advance copies via email. Please include a
telephone number to enable DOE staff to make follow-up contact, if
needed.
C. Conduct of the Public Meeting
DOE will designate a DOE official to preside at the public meeting
and may also use a professional facilitator to aid discussion. The
meeting will not be a judicial or evidentiary-type public hearing, but
DOE will conduct it in accordance with section 336 of EPCA (42 U.S.C.
6306). A court reporter will be present to record the proceedings and
prepare a transcript. DOE reserves the right to schedule the order of
presentations and to establish the procedures governing the conduct of
the public meeting. There shall not be discussion of proprietary
information, costs or prices, market share, or other commercial matters
regulated by U.S. anti-trust laws. After the public meeting, interested
parties may submit further comments on the proceedings, as well as on
any aspect of the rulemaking, until the end of the comment period.
The public meeting will be conducted in an informal, conference
style. DOE will present summaries of comments received before the
public meeting, allow time for prepared general statements by
participants, and encourage all interested parties to share their views
on issues affecting this rulemaking. Each participant will be allowed
to make a general statement (within time limits determined by DOE),
before the discussion of specific topics. DOE will allow, as time
permits, other participants to comment briefly on any general
statements.
At the end of all prepared statements on a topic, DOE will permit
participants to clarify their statements briefly and comment on
statements made by others. Participants should be prepared to answer
questions by DOE and by other participants concerning these issues. DOE
representatives may also ask questions of participants concerning other
matters relevant to this rulemaking. The official conducting the public
meeting will accept additional comments or questions from those
attending, as time permits. The presiding official will announce any
further procedural rules or modification of the above procedures that
may be needed for the proper conduct of the public meeting.
A transcript of the public meeting will be included in the docket,
which can be viewed as described in the Docket section at the beginning
of this notice of the proposed rulemaking, and will be accessible on
the DOE Web site. In addition, any person may buy a copy of the
transcript from the transcribing reporter.
D. Submission of Comments
DOE will accept comments, data, and information regarding this
proposed rule before or after the public meeting, but no later than the
date provided in the DATES section at the beginning of this proposed
rule. Interested parties may submit comments using any of the methods
described in the ADDRESSES section at the beginning of this notice of
proposed rulemaking.
Submitting comments via 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
[[Page 66229]]
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, written in English, and are free of any defects or
viruses. Documents should not contain special characters or any form of
encryption and, if possible, they should carry the electronic signature
of the author.
Campaign form letters. Please submit campaign form letters by the
originating organization in batches of between 50 to 500 form letters
per PDF or as one form letter with a list of supporters' names compiled
into one or more PDFs. This reduces comment processing and posting
time.
Confidential Business Information. Pursuant to 10 CFR 1004.11, any
person submitting information that he or she believes to be
confidential and exempt by law from public disclosure should submit via
email, postal mail, or hand delivery/courier two well-marked copies:
One copy of the document marked ``confidential'' including all the
information believed to be confidential, and one copy of the document
marked ``non-confidential'' with the information believed to be
confidential deleted. Submit these documents via email or on a CD, if
feasible. DOE will make its own determination about the confidential
status of the information and treat it according to its determination.
Factors of interest to DOE when evaluating requests to treat
submitted information as confidential include: (1) A description of the
items; (2) whether and why such items are customarily treated as
confidential within the industry; (3) whether the information is
generally known by or available from other sources; (4) whether the
information has previously been made available to others without
obligation concerning its confidentiality; (5) an explanation of the
competitive injury to the submitting person which would result from
public disclosure; (6) when such information might lose its
confidential character due to the passage of time; and (7) why
disclosure of the information would be contrary to the public interest.
It is DOE's policy that all comments may be included in the public
docket, without change and as received, including any personal
information provided in the comments (except information deemed to be
exempt from public disclosure).
E. 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 the proposed definition of ``light commercial water heater''
appropriate, and is it appropriate to test commercial water heaters
meeting this definition under the uniform descriptor, while testing all
other commercial water heaters using thermal efficiency and standby
loss?
2. Is information or data available regarding the translation of
current first-hour ratings to a first-hour rating determined using the
proposed 125 [deg]F set point? What is the effect of such translation
on the appropriate breakpoints between different size categories?
3. Is the proposed method of characterizing water heaters as point-
of-use, low, medium, or high appropriate and sufficient?
4. Are the draw patterns proposed for the different water heater
size categories appropriate?
5. What is the added burden, if any, in requiring a 24-hour pre-
conditioning period for storage-type water heaters compared to current
practice?
6. Is the proposed change to the nominal water delivery temperature
to 125 [deg]F appropriate, and if not, what data or information is
available that would justify a different water delivery temperature?
7. Is the proposed method for setting the thermostat(s) of storage-
type water heaters appropriate?
8. The addition of terms to quantify daily electric energy
consumption separately from fossil fuel energy consumption and adding
separate estimates of annual fossil fuel energy consumption and annual
electrical energy consumption in addition to the overall annual energy
consumption.
VI. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of today's 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 October 28, 2013.
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.
0
2. Section 429.17 is amended by adding new paragraphs (a)(2)(iii),
(a)(2)(iv), (c), and (d) to read as follows:
Sec. 429.17 Residential water heaters.
(a) * * *
(2) * * *
[[Page 66230]]
(iii) Any represented value of the rated storage volume must be
calculated as the mean of the measured storage volumes, Vst,
of all the units within the sample.
(iv) Any represented value of first-hour rating for storage water
heaters or maximum gallons per minute (gpm for instantaneous water
heaters must be calculated as the mean of the measured first-hour
ratings or measured max gpm ratings, respectively, of all the units
within the sample.
* * * * *
(c) Determination of ratings for untested basic models.
Manufacturers of gas-fired water heaters are not required to test other
models that differ from tested basic models only in whether the unit
uses natural gas or propane gas. In lieu of testing, the represented
value for a model that utilizes propane gas must be identical to the
basic model that utilizes natural gas as long as the rated input
ratings are within 10% for both basic models.
(d) Represented values. The requirements of Sec. 429.17 are
applicable to all values reported in accordance with paragraphs (b) and
(c) of this section. Represented values of energy factor shall be
rounded off to the nearest 0.01.
0
3. Section 429.44 is amended by:
0
a. Redesignating paragraphs (a), (b) and (c) as (b), (c) and (d);
0
b. Adding a new paragraph (a); and
0
c. Revising newly redesignated paragraph (b).
The revisions and additions read as follows:
Sec. 429.44 Commercial water heating equipment.
(a) For light commercial water heaters, all represented values
should be determined in accordance with Sec. 429.17.
(b) Determination of Represented Value for All Types of Commercial
Water Heaters except Light Commercial Water Heaters. Manufacturers can
determine the represented value, which includes the certified rating,
for each basic model of commercial water heating equipment except light
commercial water heaters, either by testing, in conjunction with the
applicable sampling provisions, or by applying a validated AEDM.
* * * * *
0
4. Add Sec. 429.134 to read as follows:
Sec. 429.134 Product-specific enforcement provisions.
(a) [Reserved].
(b) [Reserved].
(c) [Reserved].
(d) Residential Water Heaters and Light Commercial Water Heaters.
(1) Verification of rated first-hour rating and rated maximum gpm
rating. The first-hour rating (for storage water heaters) or maximum
gallons per minute (gpm) rating (for instantaneous water heaters) of
the basic model will be measured pursuant to the test requirements of
part 430 for each unit tested. The results of the measurement(s) will
be averaged and compared to the value of first-hour rating (for storage
water heaters) or maximum gpm rating (for instantaneous water heaters)
certified by the manufacturer. The certified rating will be considered
valid only if the measurement is within five percent of the certified
rating.
(i) If the certified first-hour rating or maximum gpm rating is
found to be valid, that rating will be used as the basis for
determining the applicable draw pattern pursuant to the test
requirements of part 430 for each unit tested.
(ii) If the certified first-hour rating or maximum gpm rating is
found to be invalid, the average measured rating will serve as the
basis for determining the applicable draw pattern pursuant to the test
requirements of part 430 for each unit tested.
(2) Verification of rated storage volume. The storage volume of the
basic model will be measured pursuant to the test requirements of part
430 for each unit tested. The results of the measurement(s) will be
averaged and compared to the rated storage volume certified by the
manufacturer. The certified rating will be considered valid only if the
measurement is within five percent of the certified rating.
(i) If the certified rated storage volume is found to be valid,
that volume will be used as the basis for calculation of the required
energy factor for the basic model.
(ii) If the certified rated storage volume is found to be invalid,
the average measured volume will be used as the basis for calculation
of the required energy factor for the basic model.
PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS
0
5. 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
6. Section 430.2 is amended by adding the definitions of ``Electric
instantaneous water heater,'' ``Electric storage water heater,'' ``Gas-
fired instantaneous water heater,'' ``Gas-fired storage water heater,''
``Heat pump water heater,'' and ``Oil storage water heater'' in
alphabetical order, to read as follows:
Sec. 430.2 Definitions.
* * * * *
Electric instantaneous water heater means a water heater that uses
electricity as the energy source, initiates heating based on sensing
water flow, is not capable of delivering water at a controlled
temperature of 180 [deg]F (82 [deg]C) or greater, has a maximum
nameplate input rating 12 kW (40,956 Btu/h) or less, and has a rated
storage capacity of less than 2 gallons (7.6 liters). The unit may use
a fixed or variable burner input.
* * * * *
Electric storage water heater means a water heater that uses
electricity as the energy source, is not capable of heating and storing
water at a thermostatically controlled temperature of 180 [deg]F (82
[deg]C) or greater, has a maximum nameplate input rating of 12 kW
(40,956 Btu/h) or less, and has a rated storage capacity of not less
than 2 gallons (7.6 liters) nor more than 120 gallons (450 liters).
* * * * *
Gas-fired instantaneous water heater means a water heater that uses
gas as the main energy source, initiates heating based on sensing water
flow, is not capable of delivering water at a controlled temperature of
180[emsp14] [deg]F (82 [deg]C) or greater, has a maximum nameplate
input rating less than 200,000 Btu/h (210 MJ/h), and has a rated
storage capacity of less than 2 gallons (7.6 liters). The unit may use
a fixed or variable burner input.
Gas-fired storage water heater means a water heater that uses gas
as the main energy source, is not capable of heating and storing water
at a thermostatically controlled temperature of 180[emsp14] [deg]F (82
[deg]C) or greater, has a maximum nameplate input rating of 75,000 Btu/
h (79 MJ/h) or less, and has a rated storage capacity of not less than
2 gallons (7.6 liters) nor more than 120 gallons (380 liters).
* * * * *
Heat pump water heater means a water heater that uses electricity
as the energy source, is not capable of heating and storing water at a
thermostatically-controlled temperature of 180 [deg]F (82 [deg]C) or
greater, has a maximum current rating of 24 amperes (including the
compressor and all auxiliary equipment such as fans, pumps, controls,
and, if on the same circuit, any resistive elements) for an input
voltage of 250 volts or less, and, has a rated storage capacity of 120
gallons (450 liters) or less.
* * * * *
[[Page 66231]]
Oil storage water heater means a water heater that uses oil as the
energy source, is not capable of heating and storing water at a
thermostatically controlled temperature of 180[emsp14] [deg]F (82
[deg]C) or greater, has a nameplate input rating of 105,000 Btu/h (110
MJ/h) or less, and has a manufacturer's rated storage capacity of 120
gallons (190 liters) or less.
* * * * *
0
7. Section 430.3 is amended by:
0
a. Adding paragraph (f)(11);
0
b. Redesignating paragraphs (h) through (p) as (i) through (o),
respectively; and
0
c. Adding a new paragraph (h).
The additions read as follows:
Sec. 430.3 Materials incorporated by reference.
* * * * *
(f) * * *
(11) ASHRAE 41.1-1986 (RA 2006), Standard Method for Temperature
Measurement, ASHRAE approved June 27, 2007, ANSI approved March 25,
2008, IBR approved for appendix E to subpart B of this part.
* * * * *
(h) ASTM. American Society for Testing and Materials International,
100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959
(www.astm.org).
(1) ASTM D2156-09 (``ASTM D2156''), Standard Test Method for Smoke
Density in Flue Gases from Burning Distillate Fuels, Edition 09, ASTM
approved December 1, 2009, IBR approved for appendix E to subpart B of
this part.
(2) [Reserved]
* * * * *
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) The estimated annual operating cost for
water heaters shall be--
(i) For a gas or oil water heater, the sum of (a) the product of
the annual gas or oil energy consumption, determined according to
section 6.1.10 or 6.2.7 of appendix E of this subpart, times the
representative average unit cost of gas or oil, as appropriate, in
dollars per Btu as provided by the Secretary; plus (b) the product of
the annual electric energy consumption, determined according to section
6.1.9 or 6.2.6 of appendix E of this subpart, times the representative
average unit cost of electricity in dollars per kilowatt-hour as
provided by the Secretary, the resulting sum then being rounded off to
the nearest dollar per year.
(ii) For an electric water heater, the product of the annual energy
consumption, determined according to section 6.1.9 or 6.2.6 of appendix
E of this subpart, times the representative average unit cost of
electricity in dollars per kilowatt-hour as provided by the Secretary,
the resulting product then being rounded off to the nearest dollar per
year.
(2) For an individual test, the tested energy factor for a water
heater shall be--
(i) For a gas or oil water heater, as determined by section 6.1.7
or 6.2.4 of appendix E of this subpart rounded to the nearest 0.01.
(ii) For an electric water heater, as determined by section 6.1.7
or 6.2.4 of appendix E of this subpart rounded to the nearest 0.01.
* * * * *
0
9. Appendix E to Subpart B of Part 430 is revised to read as follows:
Appendix E to Subpart B of Part 430--Uniform Test Method for Measuring
the Energy Consumption of Water Heaters
Note: After [date 365 days after publication of a final rule in
the Federal Register that establishes a conversion factor, or
December 31, 2015, whichever is later], any representations made
with respect to the energy use or efficiency of residential water
heaters and commercial water heaters covered by this test method
must be made in accordance with the results of testing pursuant to
this appendix.
Manufacturers conducting tests of residential water heaters and
commercial water heaters covered by this test method after [date 365
days after publication of the test procedure final rule in the
Federal Register] and prior to [date 365 days after publication of
the final rule in the Federal Register that establishes a conversion
factor, or December 31, 2015, whichever is later] must conduct such
test in accordance with either this appendix or previous test
method. For residential water heaters the previous test method is
appendix E as it appeared at 10 CFR part 430, subpart B, appendix E,
in the 10 CFR parts 200 to 499 edition revised as of January 1,
2013. For commercial water heaters the previous test method is 10
CFR 431.106 in the 10 CFR parts 200 to 499 edition revised as of
January 1, 2013. Any representations made with respect to the energy
use or efficiency of such water heaters must be in accordance with
whichever version is selected.
1. Definitions
1.1. Cut-in means the time when or water temperature at which a
water heater control or thermostat acts to increase the energy or
fuel input to the heating elements, compressor, or burner.
1.2. Cut-out means the time when or water temperature at which a
water heater control or thermostat acts to reduce to a minimum the
energy or fuel input to the heating elements, compressor, or burner.
1.3. Design Power Rating means the nominal power rating that a
water heater manufacturer assigns to a particular design of water
heater, expressed in kilowatts or Btu (kJ) per hour as appropriate.
1.4. Draw Cluster means a collection of water draw events during
the simulated-use test that are closely grouped in time.
1.5. Energy Factor means the measure of water heater overall
efficiency.
1.6. First-Hour Rating means the estimate of the maximum volume
of ``hot'' water that a storage-type water heater can supply within
an hour that begins with the water heater fully heated (i.e., with
all thermostats satisfied). It is a function of both the storage
volume and the recovery rate.
1.7. Heat Trap means a device which can be integrally connected
or independently attached to the hot and/ or cold water pipe
connections of a water heater such that the device will develop a
thermal or mechanical seal to minimize the recirculation of water
due to thermal convection between the water heater tank and its
connecting pipes.
1.8. Maximum gpm (L/ min) Rating means the maximum gallons per
minute (liters per minute) of hot water that can be supplied by an
instantaneous water heater while maintaining a nominal temperature
rise of 67 [deg]F (37.3 [deg]C) during steady-state operation, as
determined by testing in accordance with section 5.3.2 of this
appendix.
1.9. Rated Storage Volume means the water storage capacity of a
water heater, in gallons (liters), as certified by the manufacturer
pursuant to 10 CFR part 429.
1.10. Recovery Efficiency means the ratio of energy delivered to
the water to the energy content of the fuel consumed by the water
heater.
1.11. Recovery Period means the time when the main burner of a
storage water heater is raising the temperature of the stored water.
1.12. Standby means the time, in hours, during which water is
not being withdrawn from the water heater. There are two standby
time intervals used within this test procedure:
[tau]stby,1 represents the elapsed time between the time
at which the maximum mean tank temperature is observed after the
first draw cluster and the minute prior to the start of the first
draw following the end of the first draw cluster of the 24-hour
simulated use test; [tau]stby,2 represents the total time
during the 24-hour simulated use test when water is not being
withdrawn from the water heater.
1.13. Symbol Usage. The following identity relationships are
provided to help clarify the symbology used throughout this
procedure:
Cp specific heat of water
Eannual annual energy consumption of a water heater
Eannual,e annual electrical energy consumption of a water heater
Eannual,f annual fossil-fuel energy consumption of a water heater
Ef energy factor of a water heater
Fhr first-hour rating of a storage-type water heater
Fmax maximum gpm (L/ min) rating of an instantaneous water heater
rated at a temperature rise of 67 [deg]F (37.3 [deg]C)
[[Page 66232]]
i a subscript to indicate the draw number during a test
Mi mass of water removed during the ith draw of the 24-hr simulated
use test
M*i for storage-type water heaters, mass of water removed during the
ith draw during the first-hour rating test
M10m for instantaneous water heaters, mass of water removed
continuously during a 10-minute interval in the maximum gpm (L/min)
rating test
n for storage-type water heaters, total number of draws during the
first-hour rating test
N total number of draws during the 24-hr simulated use test
Q total fossil fuel and/or electric energy consumed during the
entire 24-hr simulated use test
Qd daily water heating energy consumption adjusted for net change in
internal energy
Qda Qd with adjustment for variation of tank to ambient
air temperature difference from nominal value
Qdm overall adjusted daily water heating energy consumption
including Qda and QHWD
Qe total electrical energy used during the 24-hour simulated use
test
Qf total fossil fuel energy used by the water heater during the 24-
hour simulated use test
Qhr hourly standby losses
QHW daily energy consumption to heat water at the measured average
temperature rise across the water heater
QHW,67 [deg]F daily energy consumption to heat quantity of water
removed during test over a temperature rise of 67 [deg]F (37.3
[deg]C)
QHWD adjustment to daily energy consumption, QHW, due to
variation of the temperature rise across the water heater not equal
to the nominal value of 67 [deg]F
Qr energy consumption of water heater from the beginning of the test
to the end of the first recovery period following the first draw,
which may extend beyond subsequent draws
Qstby total energy consumed by the water heater during the standby
time interval [tau]stby,1
Qsu,0 total fossil fuel and/or electric energy consumed from the
beginning of the test to the end of the cutout following the first
draw cluster
Qsu,f total fossil fuel and/or electric energy consumed from the
beginning of the test to the initiation of the first draw following
the first draw cluster
T0 mean tank temperature at the beginning of the 24-hr simulated use
test
T24 mean tank temperature at the end of the 24-hr simulated use test
Ta,stby average ambient air temperature during standby periods of
the 24-hr simulated use test
Tdel for instantaneous water heaters, average outlet water
temperature during a 10-minute continuous draw interval in the
maximum gpm (L/ min) rating test
Tdel,i average outlet water temperature during the ith draw of the
24-hr simulated use test
Tin for instantaneous water heaters, average inlet water temperature
during a 10-minute continuous draw interval in the maximum gpm (L/
min) rating test
Tin,i average inlet water temperature during the ith draw of the 24-
hr simulated use test
Tmax,1 maximum measured mean tank temperature after cut-out
following the first draw of the 24-hr simulated use test
Tstby average storage tank temperature during the standby period
[tau]stby,2 of the 24-hr simulated use test
Tsu,0 maximum measured mean tank temperature at the beginning of the
standby period which occurs after cut-out following the final draw
of the first draw cluster
Tsu,f measured mean tank temperature at the end of the standby
period which occurs at the minute prior to commencement of the first
draw that follows the end of the first draw cluster
Tt,stby average storage tank temperature during the standby period
[tau]stby,1 of the 24-hr simulated use test
T*del,i for storage-type water heaters, average outlet
water temperature during the ith draw (i=1 to n) of the first-hour
rating test
T*max,i for storage-type water heaters, maximum outlet
water temperature observed during the ith draw (i=1 to n) of the
first-hour rating test
T*min,i for storage-type water heaters, minimum outlet
water temperature to terminate the ith draw (i=1 to n) of the first-
hour rating test
UA standby loss coefficient of a storage-type water heater
Vi volume of water removed during the ith draw (i=1 to N) of the 24-
hr simulated use test
V*i volume of water removed during the ith draw (i=1 to n) of the
first-hour rating test
V10m for instantaneous water heaters, volume of water removed
continuously during a 10-minute interval in the maximum gpm (L/ min)
rating test
Vst measured storage volume of the storage tank
Wf weight of storage tank when completely filled with water
Wt tare weight of storage tank when completely empty of water
[eta]r recovery efficiency
[rho] density of water
[tau]stby,1 elapsed time between the time the maximum mean tank
temperature is observed after the first draw cluster and the minute
prior to the start of the first draw following the first draw
cluster
[tau]stby,2 overall time of standby periods when no water is
withdrawn during the 24-hr simulated use test
2. Test Conditions
2.1 Installation Requirements. Tests shall be performed with the
water heater and instrumentation installed in accordance with
Section 4 of this appendix.
2.2 Ambient Air Temperature. The ambient air temperature shall
be maintained between 65.0 [deg]F and 70.0 [deg]F (18.3 [deg]C and
21.1 [deg]C) on a continuous basis. For heat pump water heaters, the
dry bulb temperature shall be maintained at 67.5 [deg]F
1 [deg]F (19.7 [deg]C 0.6 [deg]C) and, in addition, the
relative humidity shall be maintained between 48% and 52% throughout
the test.
2.3 Supply Water Temperature. The temperature of the water being
supplied to the water heater shall be maintained at 58 [deg]F 2 [deg]F (14.4 [deg]C 1.1 [deg]C) throughout the
test.
2.4 Storage Tank Temperature. The thermostats of a storage-type
water heater shall be set so that water is delivered at a
temperature of 125 [deg]F 5 [deg]F (51.7[deg]C 2.8 [deg]C).
2.5 Set Point Temperature. The thermostat of instantaneous water
heaters shall be set to deliver water at a temperature of 125 [deg]F
5 [deg]F (51.7 [deg]C 2.8 [deg]C).
2.6 Supply Water Pressure. During the test when water is not
being withdrawn, the supply pressure shall be maintained between 40
psig (275 kPa) and the maximum allowable pressure specified by the
water heater manufacturer.
2.7 Electrical and/ or Fossil Fuel Supply.
2.7.1 Electrical. Maintain the electrical supply voltage to
within 1% of the center of the voltage range specified
by the water heater and/or heat pump manufacturer.
2.7.2 Natural Gas. Maintain the supply pressure in accordance
with the manufacturer's specifications. If the supply pressure is
not specified, maintain a supply pressure of 7-10 inches of water
column (1.7-2.5 kPa). If the water heater is equipped with a gas
appliance pressure regulator, the regulator outlet pressure shall be
within 10% of the manufacturer's specified manifold
pressure. For all tests, use natural gas having a heating value of
approximately 1,025 Btu per standard cubic foot (38,190 kJ per
standard cubic meter).
2.7.3 Propane Gas. Maintain the supply pressure in accordance
with the manufacturer's specifications. If the supply pressure is
not specified, maintain a supply pressure of 11-13 inches of water
column (2.7-3.2 kPa). If the water heater is equipped with a gas
appliance pressure regulator, the regulator outlet pressure shall be
within 10% of the manufacturer's specified manifold
pressure. For all tests, use propane gas with a heating value of
approximately 2,500 Btu per standard cubic foot (93,147 kJ per
standard cubic meter).
2.7.4 Fuel Oil Supply. Maintain an uninterrupted supply of fuel
oil. Use fuel oil having a heating value of approximately 138,700
Btu per gallon (38,660 kJ per liter).
3. Instrumentation
3.1 Pressure Measurements. Pressure-measuring instruments shall
have an error no greater than the following values:
------------------------------------------------------------------------
Item measured Instrument accuracy Instrument precision
------------------------------------------------------------------------
Gas pressure................ 0.1 inch 0.05
of water column inch of water
(0.025 column (0.012 kPa).
Atmospheric pressure........ 0.1 inch 0.05
of mercury column inch of mercury
(0.34 column (0.17 kPa).
[[Page 66233]]
Water pressure.............. 1.0 0.50
pounds per square pounds per square
inch (6.9 kPa). minus>3.45 kPa).
------------------------------------------------------------------------
3.2 Temperature Measurement
3.2.1 Measurement. Temperature measurements shall be made in
accordance with the Standard Method for Temperature Measurement,
ASHRAE Standard 41.1-1986 (RA 2006).
3.2.2 Accuracy and Precision. The accuracy and precision of the
instruments, including their associated readout devices, shall be
within the following limits:
------------------------------------------------------------------------
Item measured Instrument accuracy Instrument precision
------------------------------------------------------------------------
Air dry bulb temperature.... 0.2 0.1
[deg]F (0.1 [deg]C). minus>0.06 [deg]C).
Air wet bulb temperature.... 0.2 0.1
[deg]F (0.1 [deg]C). minus>0.06 [deg]C).
Inlet and outlet water 0.2 0.1
temperatures. [deg]F (0.1 [deg]C). minus>0.06 [deg]C).
Storage tank temperatures... 0.5 0.25
[deg]F (0.3 [deg]C). minus>0.14 [deg]C).
------------------------------------------------------------------------
3.2.3 Scale Division. In no case shall the smallest scale
division of the instrument or instrument system exceed 2 times the
specified precision.
3.2.4 Temperature Difference. Temperature difference between the
entering and leaving water may be measured with any of the
following:
a. A thermopile
b. Calibrated resistance thermometers
c. Precision thermometers
d. Calibrated thermistors
e. Calibrated thermocouples
f. Quartz thermometers
3.2.5 Thermopile Construction. If a thermopile is used, it shall
be made from calibrated thermocouple wire taken from a single spool.
Extension wires to the recording device shall also be made from that
same spool.
3.2.6 Time constant. The time constant of the instruments used
to measure the inlet and outlet water temperatures shall be no
greater than 2 seconds.
3.3 Liquid Flow Rate Measurement. The accuracy of the liquid
flow rate measurement, using the calibration if furnished, shall be
equal to or less than 1% of the measured value in mass
units per unit time.
3.4 Electrical Energy. The electrical energy used shall be
measured with an instrument and associated readout device that is
accurate within 0.5% of the reading.
3.5 Fossil Fuels. The quantity of fuel used by the water heater
shall be measured with an instrument and associated readout device
that is accurate within 1% of the reading.
3.6 Mass Measurements. For mass measurements greater than or
equal to 10 pounds (4.5 kg), a scale that is accurate within 0.5% of the reading shall be used to make the measurement. For
mass measurements less than 10 pounds (4.5 kg), the scale shall
provide a measurement that is accurate within 0.1 pound
(0.045 kg).
3.7 Heating Value. The higher heating value of the natural gas,
propane, or fuel oil shall be measured with an instrument and
associated readout device that is accurate within 1% of
the reading. The heating values of natural gas and propane must be
corrected from those reported at standard temperature and pressure
conditions to provide the heating value at the temperature and
pressure measured at the fuel meter.
3.8 Time. The elapsed time measurements shall be measured with
an instrument that is accurate within 0.5 seconds per
hour.
3.9 Volume. Volume measurements shall be measured with an
accuracy of 2% of the total volume.
3.10 Relative Humidity. If a relative humidity (RH) transducer
is used to measure the relative humidity of the surrounding air
while testing heat pump water heaters, the relative humidity shall
be measured with an accuracy of 1.5% RH.
4. Installation
4.1 Water Heater Mounting. A water heater designed to be
freestanding shall be placed on a \3/4\ inch (2 cm) thick plywood
platform supported by three 2 x 4 inch (5 cm x 10 cm) runners. If
the water heater is not approved for installation on combustible
flooring, suitable non-combustible material shall be placed between
the water heater and the platform. Counter-top water heaters shall
be placed against a simulated wall section. Wall-mounted water
heaters shall be supported on a simulated wall in accordance with
the manufacturer-published installation instructions. When a
simulated wall is used, the construction shall be 2 x 4 inch (5 cm x
10 cm) studs, faced with \3/4\ inch (2 cm) plywood. For heat pump
water heaters not delivered as a single package, the units shall be
connected in accordance with the manufacturer-published installation
instructions and the overall system shall be placed on the above-
described plywood platform. If installation instructions are not
provided by the heat pump manufacturer, uninsulated 8 foot (2.4 m)
long connecting hoses having an inside diameter of \5/8\ inch (1.6
cm) shall be used to connect the storage tank and the heat pump
water heater. The testing of the water heater shall occur in an area
that is protected from drafts of more than 50 ft/ min (2.5 m/s) from
room ventilation registers, windows, or other external sources of
air movement.
4.2 Water Supply. Connect the water heater to a water supply
capable of delivering water at conditions as specified in Sections
2.3 and 2.6 of this appendix.
4.3 Water Inlet and Outlet Configuration. For freestanding water
heaters that are taller than 36 inches (91.4 cm), inlet and outlet
piping connections shall be configured in a manner consistent with
Figures 1 and 2. Inlet and outlet piping connections for wall-
mounted water heaters shall be consistent with Figure 3. For
freestanding water heaters that are 36 inches or less in height and
not supplied as part of a counter-top enclosure (commonly referred
to as an under-the-counter model), inlet and outlet piping shall be
installed in a manner consistent with Figures 4, 5, and 6. For water
heaters that are supplied with a counter-top enclosure, inlet and
outlet piping shall be made in a manner consistent with Figures 7A
and 7B, respectively. The vertical piping noted in Figures 7A and 7B
shall be located (whether inside the enclosure or along the outside
in a recessed channel) in accordance with the manufacturer-published
installation instructions.
All dimensions noted in Figures 1 through 7 shall be achieved.
All piping between the water heater and inlet and outlet temperature
sensors, noted as TIN and TOUT in the figures,
shall be Type ``L'' hard copper having the same diameter as the
connections on the water heater. Unions may be used to facilitate
installation and removal of the piping arrangements. A pressure
gauge and diaphragm expansion tank shall be installed in the supply
water piping at a location upstream of the inlet temperature sensor.
An appropriately rated pressure and temperature relief valve shall
be installed on all water heaters at the port specified by the
manufacturer. Discharge piping for the relief valve shall be non-
metallic. If heat traps, piping insulation, or pressure relief valve
insulation are supplied with the water heater, they shall be
installed for testing. Except when using a simulated wall, clearance
shall be provided such that none of the piping contacts other
surfaces in the test room.
4.4 Fuel and/or Electrical Power and Energy Consumption. Install
one or more instruments that measure, as appropriate, the quantity
and rate of electrical energy and/or fossil fuel consumption in
accordance with section 3.
4.5 Internal Storage Tank Temperature Measurements. For water
heaters with rated storage volumes greater than or equal to 20
gallons, install six temperature measurement sensors inside the
water heater tank with a vertical distance of at least 4 inches (100
mm) between successive sensors. For water heaters with rated storage
volumes between 2 and 20 gallons, install three temperature
measurement sensors inside the water heater
[[Page 66234]]
tank. A temperature sensor shall be positioned at the vertical
midpoint of each of the six equal volume nodes within a tank larger
than 20 gallons or the three equal volume nodes within a tank
between 2 and 20 gallons. Nodes designate the equal volumes used to
evenly partition the total volume of the tank. As much as is
possible, the temperature sensor should be positioned away from any
heating elements, anodic protective devices, tank walls, and flue
pipe walls. If the tank cannot accommodate six temperature sensors
and meet the installation requirements specified above, install the
maximum number of sensors which comply with the installation
requirements. The temperature sensors shall be installed either
through: (1) The anodic device opening; (2) the relief valve
opening; or (3) the hot water outlet. If installed through the
relief valve opening or the hot water outlet, a tee fitting or
outlet piping, as applicable, shall be installed as close as
possible to its original location. If the relief valve temperature
sensor is relocated, and it no longer extends into the top of the
tank, a substitute relief valve that has a sensing element that can
reach into the tank shall be installed. If the hot water outlet
includes a heat trap, the heat trap shall be installed on top of the
tee fitting. Added fittings shall be covered with thermal insulation
having an R value between 4 and 8 h[middot]ft\2\[middot][deg]F/Btu
(0.7 and 1.4 m\2\[middot][deg]C/W).
4.6 Ambient Air Temperature Measurement. Install an ambient air
temperature sensor at the vertical mid-point of the water heater and
approximately 2 feet (610 mm) from the surface of the water heater.
The sensor shall be shielded against radiation.
4.7 Inlet and Outlet Water Temperature Measurements. Install
temperature sensors in the cold-water inlet pipe and hot-water
outlet pipe as shown in Figures 1, 2, 3, 4, 5, 6, 7a, and 7b, as
applicable.
4.8 Flow Control. A valve or valves shall be installed to
provide flow as specified in sections 5.2.4.1 and 5.4 for storage
tank water heaters and sections 5.3.1 and 5.4 for instantaneous
water heaters.
4.9 Flue Requirements.
4.9.1 Gas-Fired Water Heaters. Establish a natural draft in the
following manner. For gas-fired water heaters with a vertically
discharging draft hood outlet, a 5-foot (1.5-meter) vertical vent
pipe extension with a diameter equal to the largest flue collar size
of the draft hood shall be connected to the draft hood outlet. For
gas-fired water heaters with a horizontally discharging draft hood
outlet, a 90-degree elbow with a diameter equal to the largest flue
collar size of the draft hood shall be connected to the draft hood
outlet. A 5-foot (1.5-meter) length of vent pipe shall be connected
to the elbow and oriented to discharge vertically upward. Direct
vent gas-fired water heaters shall be installed with venting
equipment specified in the manufacturer's instructions using the
minimum vertical and horizontal lengths of vent pipe recommended by
the manufacturer.
4.9.2 Oil-Fired Water Heaters. Establish a draft at the flue
collar at the value specified in the manufacturer's instructions.
Establish the draft by using a sufficient length of vent pipe
connected to the water heater flue outlet, and directed vertically
upward. For an oil-fired water heater with a horizontally
discharging draft hood outlet, a 90-degree elbow with a diameter
equal to the largest flue collar size of the draft hood shall be
connected to the draft hood outlet. A length of vent pipe sufficient
to establish the draft shall be connected to the elbow fitting and
oriented to discharge vertically upward. Direct-vent oil-fired water
heaters should be installed with venting equipment as specified in
the manufacturer's instructions, using the minimum vertical and
horizontal lengths of vent pipe recommended by the manufacturer.
5. Test Procedures
5.1 Operational Mode Selection. For water heaters that allow for
multiple user-selected operational modes, all procedures specified
in this appendix shall be carried out with the water heater in the
same operational mode (i.e., only one mode). This operational mode
shall be the default mode (or similarly-named, suggested mode for
normal operation) as defined by the manufacturer in its product
literature for giving selection guidance to the consumer. For heat
pump water heaters, if a default mode is not defined in the product
literature, each test shall be conducted under an operational mode
in which both the heat pump and any electric resistance backup
heating element(s) are activated by the unit's control scheme, and
which can achieve the internal storage tank temperature specified in
this test procedure; if multiple operational modes meet these
criteria, the water heater shall be tested under the most energy-
intensive mode. If no default mode is specified and the unit does
not offer an operational mode that utilizes both the heat pump and
the electric resistance backup heating element(s), the first-hour
rating test and the simulated-use test shall be tested in heat-pump-
only mode. For other types of water heaters where a default mode is
not specified, test the unit in the most energy-intensive mode.
5.2 Storage-type Water Heaters, Including Heat Pump Water
Heaters.
5.2.1 Determination of Storage Tank Volume. Determine the
storage capacity, Vst, of the water heater under test, in
gallons (liters), by subtracting the tare weight--measured while the
tank is empty--from the gross weight of the storage tank when
completely filled with water (with all air eliminated and line
pressure applied as described in section 2.5) and dividing the
resulting net weight by the density of water at the measured
temperature.
5.2.2 Setting the Thermostat.
5.2.2.1 Single Thermostat Tanks.
5.2.2.1.1 Water Heaters with Rated Volumes Less than 20 Gallons.
Starting with a tank at the supply water temperature, initiate
normal operation of the water heater. After cut-out, initiate a draw
from the water heater at a flow rate of 1.0 gallon 0.25
gallons per minute (3.8 liters 0.95 liters per minute)
for 2 minutes. Starting 15 seconds after commencement of draw,
record the outlet temperature at 15-second intervals until the end
of the 2-minute period. Determine whether the maximum outlet
temperature is within the range of 125 [deg]F 5 [deg]F
(51.7 [deg]C 2.8 [deg]C). If not, turn off the water
heater, adjust the thermostat, and then drain and refill the tank
with supply water. Then, once again, initiate normal operation of
the water heater, and repeat the 2-minute outlet temperature test
following cut-out. Repeat this sequence until the maximum outlet
temperature during the 2-minute test is within of 125 [deg]F 5 [deg]F (51.7 [deg]C 2.8 [deg]C).
5.2.2.1.2 Water Heaters with Rated Volumes Greater than or Equal
to 20 Gallons. Starting with a tank at the supply water temperature,
initiate normal operation of the water heater. After cut-out,
initiate a draw from the water heater at a flow rate of 1.7 gallons
0.25 gallons per minute (6.4 liters 0.95
liters per minute) for 5 minutes. Starting 15 seconds after
commencement of draw, record the outlet temperature at 15-second
intervals until the end of the 5-minute period. Determine whether
the maximum outlet temperature is within the range of 125 [deg]F
5 [deg]F (51.7 [deg]C 2.8 [deg]C). If not,
turn off the water heater, adjust the thermostat, and then drain and
refill the tank with supply water. Then, once again, initiate normal
operation of the water heater, and repeat the 5-minute outlet
temperature test following cut-out. Repeat this sequence until the
maximum outlet temperature during the 5-minute test is within of 125
[deg]F 5 [deg]F (51.7 [deg]C 2.8 [deg]C).
5.2.2.2 Tanks with Two or More Thermostats. Follow the same
sequence as for a single thermostat tank (i.e., start at the supply
water temperature; operate normally until cut-out). Determine if the
setting of the thermostat that controls the uppermost heating
elements yields a maximum water temperature of 125 [deg]F 5 [deg]F (51.7 [deg]C 2.8 [deg]C), as measured
by the in-tank sensors that are positioned above the uppermost
heating element. If the tank temperature above the uppermost heating
element is not within 125 [deg]F 5 [deg]F (51.7 [deg]C
2.8 [deg]C), turn off the water heater, adjust the
thermostat, and then drain and refill the tank with supply water.
The thermostat that controls the heating element positioned next
highest in the tank shall then be set to yield a maximum water
temperature of 125 [deg]F 5 [deg]F (51.7 [deg]C 2.8 [deg]C). This process shall be repeated for the remaining
heating elements in reverse order of height until the thermostat
controlling the lowest element is correctly adjusted. When adjusting
the thermostat that controls the lowest element, the maximum mean
tank temperature after cut-out, as determined using all the in-tank
sensors, shall be 125 [deg]F 5 [deg]F (51.7 [deg]C
2.8 [deg]C). When adjusting all other thermostats, use
only the in-tank temperature sensors positioned above the heating
element in question to evaluate the maximum mean water temperature
as measured by these sensors after cut-out. For heat pump water
heaters that control an auxiliary resistive element, the thermostat
shall be set in accordance with the manufacturer's installation
instructions.
5.2.3 Power Input Determination. For all water heaters except
electric types, initiate normal operation (as described in section
5.1) and determine the power input, P, to the main burners
(including pilot light power, if any) after 15 minutes of operation.
If the water heater is equipped with a gas appliance
[[Page 66235]]
pressure regulator, the regulator outlet pressure shall be set
within 10% of that recommended by the manufacturer. For
oil-fired water heaters, the fuel pump pressure shall be within
10% of the manufacturer's specified pump pressure. All
burners shall be adjusted to achieve an hourly Btu (kJ) rating that
is within 2% of the value specified by the manufacturer.
For an oil-fired water heater, adjust the burner to give a
CO2 reading recommended by the manufacturer and an hourly
Btu (kJ) rating that is within 2% of that specified by
the manufacturer. Smoke in the flue may not exceed No. 1 smoke as
measured by the procedure in ASTM-D-2156-09.
5.2.4 First-Hour Rating Test.
5.2.4.1 General. During hot water draws for water heaters with
rated storage volumes greater than or equal to 20 gallons, remove
water at a rate of 3.0 0.25 gallons per minute (11.4
0.95 liters per minute). During hot water draws, for
storage-type water heaters with rated storage volumes below 20
gallons, remove water at a rate of 1.0 0.25 gallon per
minute ((3.8 0.95 liters per minute). Collect the water
in a container that is large enough to hold the volume removed
during an individual draw and suitable for weighing at the
termination of each draw. Alternatively, a water meter may be used
to directly measure the water volume(s) withdrawn.
5.2.4.2 Draw Initiation Criteria. Begin the first-hour rating
test by imposing a draw on the storage-type water heater. After
completion of this first draw, initiate successive draws based on
the following criteria. For gas-fired and oil-fired water heaters,
initiate successive draws when the thermostat acts to reduce the
supply of fuel to the main burner. For electric water heaters having
a single element or multiple elements that all operate
simultaneously, initiate successive draws when the thermostat acts
to reduce the electrical input supplied to the element(s). For
electric water heaters having two or more elements that do not
operate simultaneously, initiate successive draws when the
applicable thermostat acts to reduce the electrical input to the
element located vertically highest in the storage tank. For heat
pump water heaters that do not use supplemental resistive heating,
initiate successive draws immediately after the electrical input to
the compressor is reduced by the action of the water heater's
thermostat. For heat pump water heaters that use supplemental
resistive heating, initiate successive draws immediately after the
electrical input to the compressor or the uppermost resistive
element is reduced by the action of the applicable water heater
thermostat. This draw initiation criterion for heat pump water
heaters that use supplemental resistive heating, however, shall only
apply when the water located above the thermostat at cut-out is
heated to 125 [deg]F 5 [deg]F (51.7 [deg]C
2.8 [deg]C).
5.2.4.3 Test Sequence. Establish normal water heater operation.
If the water heater is not presently operating, initiate a draw. The
draw may be terminated any time after cut-in occurs. After cut-out
occurs (i.e., all thermostats are satisfied), monitor the internal
storage tank temperature sensors described in section 4.5 every
minute and determine the mean tank temperature by averaging the
values from these sensors.
Initiate a draw after a maximum mean tank temperature (the
maximum of the mean temperatures of the individual sensors) has been
observed following a cut-out. Record the time when the draw is
initiated and designate it as an elapsed time of zero ([tau]* = 0).
(The superscript * is used to denote variables pertaining to the
first-hour rating test). Record the outlet water temperature
beginning 15 seconds after the draw is initiated and at 5-second
intervals thereafter until the draw is terminated. Determine the
maximum outlet temperature that occurs during this first draw and
record it as T*max,1. For the duration of this first draw
and all successive draws, in addition, monitor the inlet temperature
to the water heater to ensure that the required 58 [deg]F 2 [deg]F (14.4 [deg]C 1.1 [deg]C) test condition
is met. Terminate the hot water draw when the outlet temperature
decreases to T*max,1-15 [deg]F (T*max,1-8.3
[deg]C). Record this temperature as T*min,1. Following
draw termination, determine the average outlet water temperature and
the mass or volume removed during this first draw and record them as
T*del,i and M*1 or V*1,
respectively.
Initiate a second and, if applicable, successive draw each time
the applicable draw initiation criteria described in section 5.2.4.2
are satisfied. As required for the first draw, record the outlet
water temperature 15 seconds after initiating each draw and at 5-
second intervals thereafter until the draw is terminated. Determine
the maximum outlet temperature that occurs during each draw and
record it as T*max,i, where the subscript i refers to the
draw number. Terminate each hot water draw when the outlet
temperature decreases to T*max,i-15 [deg]F
(T*max,i-8.3 [deg]C). Record this temperature as
T*min,i. Calculate and record the average outlet
temperature and the mass or volume removed during each draw
(T*del,i and M*i or V*i,
respectively). Continue this sequence of draw and recovery until one
hour has elapsed, then shut off the electrical power and/or fuel
supplied to the water heater.
If a draw is occurring at an elapsed time of one hour, continue
this draw until the outlet temperature decreases to
T*max,n-15 [deg]F (T*max,n-8.3 [deg]C), at
which time the draw shall be immediately terminated. (The subscript
n shall be used to denote quantities associated with the final
draw.) If a draw is not occurring at an elapsed time of one hour, a
final draw shall be imposed at one hour. This draw shall proceed for
a minimum of 30 seconds and shall be immediately terminated
thereafter when the outlet temperature first indicates a value less
than or equal to the cut-off temperature used for the previous draw
(T*min,n-1). If an outlet temperature greater than
T*min,n-1 is not measured within 30 seconds zero
additional credit shall be given towards first-hour rating (i.e.,
M*n = 0 or V*n = 0) based on the final draw.
After the final draw is terminated, calculate and record the average
outlet temperature and the mass or volume removed during the draw
(T*del,n and M*n or V*n,
respectively).
5.2.5 24-Hour Simulated Use Test.
5.2.5.1 Selection of Draw Pattern. The water heater will be
tested under a draw profile that depends upon the rated first-hour
rating obtained following the test prescribed in section 5.2.4 of
this appendix. One of four different patterns shall be applied based
on the rated first-hour rating, as shown in Table I.
Table I--Draw Pattern To Be Used for Storage Water Heaters Based on Rated First-Hour Rating
----------------------------------------------------------------------------------------------------------------
Rated first-hour rating greater than . . . and rated first-
or equal to: hour rating less than: Draw pattern to be used in simulated use test
----------------------------------------------------------------------------------------------------------------
0.................................... 20..................... Point-of-Use (Table III.1).
20................................... 55..................... Low-Usage (Table III.2).
55................................... 80..................... Medium-Usage (Table III.3).
80................................... No upper limit......... High-Usage (Table III.4).
----------------------------------------------------------------------------------------------------------------
After completing the first-hour rating test in section 5.2.4,
identify the appropriate draw pattern using Table I above. The draw
patterns are provided in Tables III.1 through III.4 in section 5.4.
Use the appropriate draw pattern when conducting the test sequence
provided in section 5.2.5.2.
5.2.5.2 Test Sequence. If the water heater is turned off, fill
the water heater with supply water and apply pressure as described
in section 2.6. Turn on the water heater and associated heat pump
unit, if present. If the water heater is turned on, initiate a water
draw that energizes the lowest heating element in the water heater.
In either case, after the cut-out occurs, begin a 24-hour pre-
conditioning period that draws water in the pattern specified by
Table I (i.e., using Table III.1, Table III.2, Table III.3, or Table
III.4, depending on the rated first-hour rating). No data need to be
recorded during this 24-hour pre-conditioning period. At the end of
this period, the 24-hour simulated-use test will begin.
At the start of the 24-hour test (after the 24-hour pre-
conditioning period), record the mean tank temperature
(T0), and the electrical and/or fuel measurement
readings, as appropriate. Begin the 24-hour simulated use test by
withdrawing the volume specified
[[Page 66236]]
in the appropriate table in section 5.4 (i.e., Table III.1, Table
III.2, Table III.3, or Table III.4, depending on the rated first-
hour rating) for the first draw at the flow rate specified. Record
the time when this first draw is initiated and assign it as the test
elapsed time ([tau]) of zero (0). Record the average storage tank
and ambient temperature every minute throughout the 24-hour
simulated use test. At the elapsed times specified in the applicable
draw pattern table in section 5.4 for a particular draw pattern,
initiate additional draws, removing the volume of hot water at the
prescribed flow rate specified by the table. The maximum allowable
deviation for any single draw is 0.25 gallons (1.9
liters). The quantity of water withdrawn during the last draw shall
be increased or decreased as necessary such that the total volume of
water withdrawn equals the prescribed daily amount for that draw
pattern 1.0 gallon ( 3.8 liters).
All draws during the 24-hour simulated use test shall be made at
the flow rates specified in the applicable draw pattern table in
section 5.4, within a tolerance of 0.25 gallons per
minute ( 0.95 liters per minute). Measurements of the
inlet and outlet temperatures shall be made 5 seconds after the draw
is initiated and at every subsequent 3-second interval throughout
the duration of each draw. The arithmetic mean of the hot water
discharge temperature and the cold water inlet temperature shall be
determined for each draw (Tdel,i and Tin,i).
Determine and record the net mass or volume removed (Mi
or Vi), as appropriate, after each draw.
At the end of the first recovery period following the first
draw, which may extend beyond subsequent draws, record the maximum
mean tank temperature observed after cut-out, Tmax,1, and
the energy consumed by an electric resistance, gas or oil-fired
water heater (including electrical energy), from the beginning of
the test, Qr. For heat pump water heaters, the total
electrical energy consumed during the first recovery by the heat
pump (including compressor, fan, controls, pump, etc.) and, if
applicable, by the resistive element(s) shall be recorded as
Qr.
At the end of the recovery period that follows the draw notated
in the applicable draw pattern table in section 5.4 as the end of
the first draw cluster during the test, determine and record the
total electrical energy and/or fossil fuel consumed since the
beginning of the test, Qsu,0. In preparation for
determining the energy consumed during standby, record the reading
given on the electrical energy (watt-hour) meter, the gas meter,
and/or the scale used to determine oil consumption, as appropriate.
Record the maximum value of the mean tank temperature after cut-out
as Tsu,0. The time at which this value is attained is the
start of the standby period. At 1-minute intervals, record the mean
tank temperature and the electric and/or fuel instrument readings
until the next draw is initiated. Just prior to initiation of the
next draw, record the mean tank temperature as Tsu,f. If
the water heater is undergoing recovery when the next draw is
initiated, record the mean tank temperature Tsu,f at the
minute prior to the start of the recovery. The time at which this
value occurs is the end of the standby period. Determine the total
electrical energy and/or fossil fuel energy consumption from the
beginning of the test to this time and record as Qsu,f.
Record the time interval between the time at which the maximum mean
tank temperature is observed after the final draw of the first draw
cluster and the end of the standby period as [tau]stby,1.
Record the time during which water is not being withdrawn from the
water heater during the entire 24-hour period as
[tau]stby,2.
5.3 Instantaneous Gas and Electric Water Heaters
5.3.1 Setting the Outlet Discharge Temperature. Initiate normal
operation of the water heater at the full input rating for electric
instantaneous water heaters and at the maximum firing rate specified
by the manufacturer for gas instantaneous water heaters. Monitor the
discharge water temperature and set to a value of 125[emsp14][deg]F
5[emsp14][deg]F (51.7 [deg]C 2.8 [deg]C)
in accordance with the manufacturer's instructions. If the water
heater is not capable of providing this discharge temperature when
the flow rate is 1.7 gallons 0.25 gallons per minute
(7.6 liters 0.95 liters per minute), then adjust the
flow rate as necessary to achieve the specified discharge water
temperature.
5.3.2 Maximum gpm Rating Test for Instantaneous Water Heaters.
Establish normal water heater operation at the full input rate for
electric instantaneous water heaters and at the maximum firing rate
for gas instantaneous water heaters with the discharge water
temperature set in accordance with section 5.3.1. During the 10-
minute test, either collect the withdrawn water for later
measurement of the total mass removed, or alternatively, use a water
meter to directly measure the water volume removed.
After recording the scale or water meter reading, initiate water
flow through the water heater, record the inlet and outlet water
temperatures beginning 15 seconds after the start of the test and at
subsequent 5-second intervals throughout the duration of the test.
At the end of 10 minutes, turn off the water. Determine the mass of
water collected, M10m, in pounds (kilograms), or the
volume of water, V10m, in gallons (liters).
5.3.3 24-hour Simulated Use Test for Instantaneous Water
Heaters.
5.3.3.1 Selection of Draw Pattern. The water heater will be
tested under a draw profile that depends upon the rated maximum gpm
rating obtained following the test prescribed in section 5.3.2. Four
different patterns can be applied, and Table II shows which draw
pattern is applied to a water heater based on its rated maximum gpm
rating.
Table II--Draw Pattern To Be Used for Instantaneous Water Heater Based on Rated Maximum GPM Rating
----------------------------------------------------------------------------------------------------------------
Rated maximum gpm rating greater than or . . . and rated maximum GPM Draw pattern to be used in
equal to: rating less than: simulated use test
----------------------------------------------------------------------------------------------------------------
0............................................ 1.7............................. Point-of-Use (Table III.1).
1.7.......................................... 2.8............................. Low-Usage (Table III.2).
2.8.......................................... 4............................... Medium-Usage (Table III.3).
4............................................ No upper limit.................. High-Usage (Table III.4).
----------------------------------------------------------------------------------------------------------------
The draw patterns are provided in Tables III.1 through III.4 in
section 5.4. Use the appropriate draw pattern when conducting the
test sequence set forth in section 5.3.3.2.
5.3.3.2 Test Sequence. Establish normal operation with the
discharge water temperature at 125[emsp14][deg]F
5[emsp14][deg]F (51.7 [deg]C 2.8 [deg]C) and set the
flow rate set as determined in section 5.2. Prior to commencement of
the 24-hour simulated use test, the unit shall remain in an idle
state in which controls are active but no water is drawn through the
unit for a period of one hour. With no draw occurring, record the
reading given by the gas meter and/or the electrical energy meter as
appropriate. Begin the 24-hour simulated use test by withdrawing the
volume specified in Table III.1 through III.4 for the first draw at
the flow rate specified. Record the time when this first draw is
initiated and designate it as an elapsed time, [tau], of 0. At the
elapsed times specified in Table III.1 through III.4 for a
particular draw pattern, initiate additional draws, removing the
volume of hot water at the prescribed flow rate specified in Table
III.1 through III.4, with the maximum allowable deviation for any
single draw being 0.5 gallons (1.9 liters). The
quantity of water drawn during the final draw shall be increased or
decreased as necessary such that the total volume of water withdrawn
equals the prescribed daily amount for that draw pattern 1.0 gallon ( 3.8 liters).
Measurements of the inlet and outlet water temperatures shall be
made 5 seconds after the draw is initiated and at every 3-second
interval thereafter throughout the duration of the draw. The
arithmetic mean of the hot water discharge temperature and the cold
water inlet temperature shall be determined for each draw. Record
the scale used to measure the mass of the withdrawn water or the
water meter reading, as appropriate, after each draw. At the end of
the recovery period following the first draw, determine and record
the fossil fuel and/or electrical energy consumed, Qr.
Following the final draw and
[[Page 66237]]
subsequent recovery, allow the water heater to remain in the standby
mode until exactly 24 hours have elapsed since the start of the test
(i.e., since [tau] = 0). At 24 hours, record the reading given by
the gas meter and/or the electrical energy meter as appropriate.
Determine the fossil fuel and/or electrical energy consumed during
the entire 24-hour simulated use test and designate the quantity as
Q.
5.4 Draw Patterns. The draw patterns to be imposed during 24-
hour simulated use tests are provided in Tables III.1 through III.4.
Each water heater under test is to be subjected to one of the draw
patterns based on its rated first-hour rating or rated maximum gpm
rating as discussed in sections 5.2.5.1 and 5.3.3.1, respectively.
Each draw pattern specifies the elapsed time in hours and minutes
during the 24-hour test when a draw is to commence, the total volume
of water in gallons (liters) that is to be removed during each draw,
and the flow rate at which each draw is to be taken, in gallons
(liters) per minute.
Table III.1--Point-of-Use Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume Flow rate \**\
Draw No. test [hh:mm] [gallons (L)] [gpm (Lpm)]
----------------------------------------------------------------------------------------------------------------
1 *............................................................. 0:00 2.0 (7.6) 1 (3.8)
2 *............................................................. 1:00 1.0 (3.8) 1 (3.8)
3 *............................................................. 1:05 0.5 (1.9) 1 (3.8)
4 *............................................................. 1:10 0.5 (1.9) 1 (3.8)
5 *............................................................. 1:15 0.5 (1.9) 1 (3.8)
6............................................................... 8:00 1.0 (3.8) 1 (3.8)
7............................................................... 8:15 2.0 (7.6) 1 (3.8)
8............................................................... 9:00 1.5 (5.7) 1 (3.8)
9............................................................... 9:15 1.0 (3.8) 1 (3.8)
----------------------------------------------------------------------------------------------------------------
Total Volume Drawn per Day: 10 gallons (38 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.
** Should the water heater have a rated maximum gpm rating less than 1 gpm (3.8 Lpm), then all draws shall be
implemented at a flow rate equal to the rated maximum gpm rating
Table III.2--Low-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume Flow rate
Draw No. test (hh:mm) (gallons) (gpm)
----------------------------------------------------------------------------------------------------------------
1 *............................................................. 0:00 15.0 (56.8) 1.7 (6.4)
2 *............................................................. 0:30 2.0 (7.6) 1 (3.8)
3 *............................................................. 1:00 1.0 (3.8) 1 (3.8)
4............................................................... 10:30 6.0 (22.7) 1.7 (6.4)
5............................................................... 11:30 4.0 (15.1) 1.7 (6.4)
6............................................................... 12:00 1.0 (3.8) 1 (3.8)
7............................................................... 12:45 1.0 (3.8) 1 (3.8)
8............................................................... 12:50 1.0 (3.8) 1 (3.8)
9............................................................... 16:15 2.0 (7.6) 1 (3.8)
10.............................................................. 16:45 2.0 (7.6) 1.7 (6.4)
11.............................................................. 17:00 3.0 (11.4) 1.7 (6.4)
----------------------------------------------------------------------------------------------------------------
Total Volume Drawn per Day: 38 gallons (144 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.
Table III.3--Medium-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume Flow rate
Draw No. test (hh:mm) (gallons) (gpm)
----------------------------------------------------------------------------------------------------------------
1 *............................................................. 0:00 15.0 (56.8) 1.7 (6.4)
2 *............................................................. 0:30 2.0 (7.6) 1 (3.8)
3 *............................................................. 1:40 9.0 (34.1) 1.7 (6.4)
4............................................................... 10:30 9.0 (34.1) 1.7 (6.4)
5............................................................... 11:30 5.0 (18.9) 1.7 (6.4)
6............................................................... 12:00 1.0 (3.8) 1 (3.8)
7............................................................... 12:45 1.0 (3.8) 1 (3.8)
8............................................................... 12:50 1.0 (3.8) 1 (3.8)
9............................................................... 16:00 1.0 (3.8) 1 (3.8)
10.............................................................. 16:15 2.0 (7.6) 1 (3.8)
11.............................................................. 16:45 2.0 (7.6) 1.7 (6.4)
12.............................................................. 17:00 7.0 (26.5) 1.7 (6.4)
----------------------------------------------------------------------------------------------------------------
Total Volume Drawn Per Day: 55 gallons (208 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.
[[Page 66238]]
Table III.4--High-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
Time during Volume Flow rate
Draw No. test (hh:mm) (gallons) (gpm)
----------------------------------------------------------------------------------------------------------------
1 *............................................................. 0:00 27.0 (102) 3 (11.4)
2 *............................................................. 0:30 2.0 (7.6) 1 (3.8)
3 *............................................................. 0:40 1.0 (3.8) 1 (3.8)
4 *............................................................. 1:40 9.0 (34.1) 1.7 (6.4)
5............................................................... 10:30 15.0 (56.8) 3 (11.4)
6............................................................... 11:30 5.0 (18.9) 1.7 (6.4)
7............................................................... 12:00 1.0 (3.8) 1 (3.8)
8............................................................... 12:45 1.0 (3.8) 1 (3.8)
9............................................................... 12:50 1.0 (3.8) 1 (3.8)
10.............................................................. 16:00 2.0 (7.6) 1 (3.8)
11.............................................................. 16:15 2.0 (7.6) 1 (3.8)
12.............................................................. 16:30 2.0 (7.6) 1.7 (6.4)
13.............................................................. 16:45 2.0 (7.6) 1.7 (6.4)
14.............................................................. 17:00 14.0 (53.0) 3 (11.4)
----------------------------------------------------------------------------------------------------------------
Total Volume Drawn Per Day: 84 gallons (318 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.
6. Computations
6.1 Storage Tank and Heat Pump Water Heaters
6.1.1 Storage Tank Capacity. The storage tank capacity,
Vst, is computed using the following:
[GRAPHIC] [TIFF OMITTED] TP04NO13.030
Where:
Vst = the storage capacity of the water heater, gal (L)
Wf = the weight of the storage tank when completely
filled with water, lb (kg)
Wt = the (tare) weight of the storage tank when
completely empty, lb (kg)
[rho] = the density of water used to fill the tank measured at the
temperature of the water, lb/gal (kg/L)
6.1.2 First-Hour Rating Computation. For the case in which the
final draw is initiated at or prior to an elapsed time of one hour,
the first-hour rating, Fhr, shall be computed using,
[GRAPHIC] [TIFF OMITTED] TP04NO13.031
Where:
n = the number of draws that are completed during the first-hour
rating test
V*i = the volume of water removed during the ith draw of
the first-hour rating test, gal (L) or, if the mass of water is
being measured,
[GRAPHIC] [TIFF OMITTED] TP04NO13.032
Where:
M*i = the mass of water removed during the ith draw of
the first-hour rating test, lb (kg).
[rho] = the water density corresponding to the average outlet
temperature measured during the ith draw, (T*del,i), lb/
gal (kg/L).
For the case in which a draw is not in progress at the elapsed
time of one hour and a final draw is imposed at the elapsed time of
one hour, the first-hour rating shall be calculated using
[GRAPHIC] [TIFF OMITTED] TP04NO13.033
where n and V*i are the same quantities as defined above,
and
V*n = the volume of water drawn during the nth (final)
draw of the first-hour rating test, gal (L)
T* del,n-1 = the average water outlet temperature
measured during the (n-1)th draw of the first-hour rating test,
[deg]F ([deg]C).
T* del,n = the average water outlet temperature measured
during the nth (final) draw of the first-hour rating test, [deg]F
([deg]C).
T*min,n-1 = the minimum water outlet temperature measured
during the (n-1)th draw of the first-hour rating test, [deg]F
([deg]C).
6.1.3 Recovery Efficiency. The recovery efficiency for gas, oil,
and heat pump storage-type water heaters, [eta]r, is
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.034
Where:
M1 = total mass removed from the start of the 24-hour
simulated use test to the end of the first recovery period, lb (kg),
or, if the volume of water is being measured,
M1 = V1[rho]1
Where:
V1 = total volume removed from the start of the 24-hour
simulated use test to the end of the first recovery period, gal (L).
[rho]1 = density of the water at the water temperature
measured at the point where the flow volume is measured, lb/gal (kg/
L).
Cp1 = specific heat of the withdrawn water evaluated at
(Tdel,1 + Tin,1)/2, Btu/(lb[middot][deg]F)
(kJ/(kg[middot][deg]C))
Tdel,1 = average water outlet temperature measured during
the draws from the start of the 24-hour simulated use test to the
end of the first recovery period, [deg]F ([deg]C).
[[Page 66239]]
Tin,1 = average water inlet temperature measured during
the draws from the start of the 24-hour simulated use test to the
end of the first recovery period, [deg]F ([deg]C).
Vst = as defined in section 6.1.1.
[rho]2 = density of stored hot water evaluated at
(Tmax,1 + To)/2, lb/gal (kg/L).
Cp2 = specific heat of stored hot water evaluated at
(Tmax,1 + To)/2, Btu/(lb[middot][deg]F) (kJ/
(kg[middot][deg]C).
Tmax,1 = maximum mean tank temperature recorded after
cut-out following the first recovery of the 24-hour simulated use
test, [deg]F ([deg]C).
To = maximum mean tank temperature recorded prior to the
first draw of the 24-hour simulated use test, [deg]F ([deg]C).
Qr = the total energy used by the water heater between
cut-out prior to the first draw and cut-out following the first
recovery period, including auxiliary energy such as pilot lights,
pumps, fans, etc., Btu (kJ). (Electrical auxiliary energy shall be
converted to thermal energy using the following conversion: 1 kWh =
3412 Btu).
The recovery efficiency for electric water heaters with immersed
heating elements is assumed to be 98%.
6.1.4 Hourly Standby Losses. The energy consumed as part of the
standby loss test of the 24-hour simulated use test, Qstby,
is computed as:
Qstby = Qsu,f-Qsu,0
Where:
Qsu,0 = cumulative energy consumption of the water heater
from the start of the 24-hour simulated use test to the time at
which the maximum mean tank temperature is attained after the
recovery following the end of the first draw cluster, Btu (kJ).
Qsu,f = cumulative energy consumption of the water heater
from the start of the 24-hour simulated use test to the minute prior
to the start of the draw following the end of the first draw cluster
or the minute prior to a recovery occurring at the start of the draw
following the end of the first draw cluster, Btu (kJ).
The hourly standby energy losses are computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.035
Where:
Qhr = the hourly standby energy losses of the water
heater, Btu/h (kJ/h).
Vst = as defined in section 6.1.1.
[rho] = density of stored hot water, (Tsu,f +
Tsu,0)/2, lb/gal (kg/L).
Cp = specific heat of the stored water, (Tsu,f
+ Tsu,0)/2, Btu/(lb[middot]F), (kJ/(kg[middot]K))
Tsu,f = the mean tank temperature observed at the minute
prior to the start of the draw following the first draw cluster or
the minute prior to a recovery occurring at the start of the draw
following the end of the first draw cluster, [deg]F ([deg]C).
Tsu,0 = the maximum mean tank temperature observed after
the first recovery following the final draw of the first draw
cluster, [deg]F ([deg]C).
[eta]r = as defined in section 6.1.3.
[tau]stby,1 = elapsed time between the time at which the
maximum mean tank temperature is observed after the first draw
cluster and the minute prior to the start of the first draw
following the end of the first draw cluster of the 24-hour simulated
use test or the minute prior to a recovery occurring at the start of
the draw following the end of the first draw cluster, h.
The standby heat loss coefficient for the tank is computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.036
Where:
UA = standby heat loss coefficient of the storage tank, Btu/
(h[middot][deg]F), (kJ/(h[middot][deg]C).
Tt,stby,1 = overall average storage tank temperature
between the time when the maximum mean tank temperature is observed
after cut-out following the first draw cluster and the minute prior
to commencement of the next draw following the first draw cluster of
the 24-hour simulated use test, [deg]F ([deg]C).
Ta,stby,1 = overall average ambient temperature between
the time when the maximum mean tank temperature is observed after
cut-out following the first draw cluster and the minute prior to
commencement of the next draw following the first draw cluster of
the 24-hour simulated use test, [deg]F ([deg]C).
6.1.5 Daily Water Heating Energy Consumption. The daily water
heating energy consumption, Qd, is computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.037
Where:
Q = Qf + Qe = total energy used by the water
heater during the 24-hour simulated use test, including auxiliary
energy such as pilot lights, pumps, fans, etc., Btu (kJ).
(Electrical energy shall be converted to thermal energy using the
following conversion: 1kWh = 3412 Btu.)
Qf = total fossil fuel energy used by the water heater
during the 24-hour simulated use test, Btu (kJ).
Qe = total electrical energy used during the 24-hour
simulated use test, Btu (kJ).
Vst = as defined in section 6.1.1.
[rho] = density of the stored hot water, evaluated at
(T24 + T0)/2, lb/gal (kg/L)
Cp = specific heat of the stored water, evaluated at
(T24 + T0)/2, Btu/(lb[middot]F), (kJ/
(kg[middot]K)).
T24 = mean tank temperature at the end of the 24-hour
simulated use test, [deg]F ([deg]C).
T0 = mean tank temperature at the beginning of the 24-
hour simulated use test, recorded one minute before the first draw
is initiated, [deg]F ([deg]C).
[eta]r = as defined in section 6.1.3.
6.1.6 Adjusted Daily Water Heating Energy Consumption. The adjusted
daily water heating energy consumption, Qda, takes into
account that the temperature difference between the storage tank and
surrounding ambient air may not be the nominal value of 57.5 [deg]F
(125 [deg]F-67.5 [deg]F) or 32.0 [deg]C (51.7 [deg]C-19.7 [deg]C) due
to the 10 [deg]F (5.6 [deg]C) allowable variation in storage tank
temperature, 125 [deg]F 5 [deg]F (51.7 [deg]C
2.8 [deg]C), and the 5 [deg]F (2.8 [deg]C) allowable variation in
surrounding ambient temperature 65 [deg]F (18.3 [deg]C) to 70 [deg]C
(21.1 [deg]C). The adjusted daily water heating energy consumption is
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.038
Where:
Qda = the adjusted daily water heating energy
consumption, Btu (kJ).
Qd = as defined in section 6.1.5.
Tstby,2 = the mean tank temperature during the total
standby portion, [tau]stby,2, of the 24-hour test, [deg]F
([deg]C).
Ta,stby,2 = the average ambient temperature during the
total standby portion, [tau]stby,2, of the 24-hour test,
[deg]F ([deg]C).
UA = as defined in section 6.1.4.
[[Page 66240]]
[tau]stby,2 = the number of hours during the 24-hour
simulated test when water is not being withdrawn from the water
heater.
A modification is also needed to take into account that the
temperature difference between the outlet water temperature and
supply water temperature may not be equivalent to the nominal value
of 67 [deg]F (125 [deg]F-58 [deg]F) or 37.3 [deg]C (51.7 [deg]C-14.4
[deg]C). The following equations adjust the experimental data to a
nominal 67 [deg]F (37.3 [deg]C) temperature rise.
The energy used to heat water, Btu/day (kJ/day), may be computed
as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.039
Where:
N = total number of draws in the draw pattern.
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb
(kg)
Cpi = the specific heat of the water of the ith draw
evaluated at (Tdel,i +Tin,i)/2, Btu/
(lb[middot][deg]F) (kJ/(kg[middot][deg]C)).
Tdel,i = the average water outlet temperature measured
during the ith draw (i = 1 to N), [deg]F ([deg]C).
Tin,i = the average water inlet temperature measured
during the ith draw (i = 1 to N), [deg]F ([deg]C).
[eta]r = as defined in section 6.1.3.
The energy required to heat the same quantity of water over a 67
[deg]F (37.3 [deg]C) temperature rise, Btu/day (kJ/day), is:
[GRAPHIC] [TIFF OMITTED] TP04NO13.040
The difference between these two values is:
QHWD = QHW,67 [deg]F-QHW
or QHWD = QHW,37.3 [deg]C-QHW
This difference (QHWD) must be added to the adjusted
daily water heating energy consumption value. Thus, the daily energy
consumption value which takes into account that the temperature
difference between the storage tank and ambient temperature may not
be 57.5 [deg]F (32.0 [deg]C) and that the temperature rise across
the storage tank may not be 67 [deg]F (37.3 [deg]C) is:
Qdm = Qda + QHWD
6.1.7 Energy Factor. The energy factor, Ef, is
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.042
Where:
N = total number of draws in the draw pattern
Qdm = the modified daily water heating energy consumption
as computed in accordance with section 6.1.6, Btu (kJ)
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb
(kg)
Cpi = the specific heat of the water of the ith draw,
evaluated at (125 [deg]F + 58 [deg]F)/2 = 91.5 [deg]F ((51.7[deg]C +
14.4[deg]C)/2 = 33 [deg]C), Btu/(lb[middot][deg]F) (kJ/
(kg[middot][deg]C)).
6.1.8 Annual Energy Consumption. The annual energy consumption
for storage-type and heat pump water heaters is computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.043
Where:
Ef = the energy factor as computed in accordance with
section 6.1.8
365 = the number of days in a year
V = the volume of hot water drawn during the applicable draw
pattern, gallons
= 10 for the point-of-use draw pattern
= 38 for the low usage draw pattern
= 55 for the medium usage draw pattern
= 84 for high usage draw pattern
[rho] = 8.24 lbm/gallon, the density of water at 125
[deg]F
CP = 1.00 Btu/lbm[deg]F, the specific heat of
water at 91.5 [deg]F
67 = the nominal temperature difference between inlet and outlet
water
6.1.9 Annual Electrical Energy Consumption. The annual
electrical energy consumption in kilowatt-hours for storage-type and
heat pump water heaters, Eannual,e, is computed as:
Eannual,e = Eannual*(Qe/Q)/3412
Where:
Eannual = the annual energy consumption as determined in
accordance with section 6.1.8, Btu (kJ)
Qe = the daily electrical energy consumption as defined
in section 6.1.5, Btu (kJ).
Q = total energy used by the water heater during the 24-hour
simulated use test in accordance with section 6.1.5, Btu (kJ)
3412 = conversion factor from Btu to kWh
6.1.10 Annual Fossil Fuel Energy Consumption. The annual fossil
fuel energy consumption for storage-type and heat pump water
heaters, Eannual,f, is computed as:
[[Page 66241]]
Eannual,f = Eannual-(Eannual,e x
3412)
Where:
Eannual = the annual energy consumption as determined in
accordance with section 6.1.8, Btu (kJ)
Eannual,e = the annual electrical energy consumption as
determined in accordance with section 6.1.9, kWh
3412 = conversion factor from kWh to Btu
6.2 Instantaneous Water Heaters.
6.2.1 Maximum gpm (L/min) Rating Computation. Compute the
maximum gpm (L/min) rating, Fmax, as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.044
which may be expressed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.045
Where:
M10m = the mass of water collected during the 10-minute
test, lb (kg).
Tdel = the average delivery temperature, [deg]F ([deg]C).
Tin = the average inlet temperature, [deg]F ([deg]C).
[rho] = the density of water at the average delivery temperature,
lb/gal (kg/L).
If a water meter is used, the maximum gpm (L/min) rating is
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.046
Where:
V10m = the volume of water measured during the 10-minute
test, gal (L).
Tdel = as defined in this section.
Tin = as defined in this section.
6.2.2 Recovery Efficiency. The recovery efficiency,
[eta]r, is computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.047
Where:
M1 = total mass removed during the first draw of the 24-
hour simulated use test, lb (kg), or, if the volume of water is
being measured,
M1 = V1 [middot] [rho]
Where:
V1 = total volume removed during the first draw of the
24-hour simulated use test, gal (L).
[rho] = density of the water at the water temperature measured at
the point where the flow volume is measured, lb/gal (kg/L).
Cp1 = specific heat of the withdrawn water,
(Tdel,1 - Tin,1)/2, Btu/(lb[middot][deg]F)
(kJ/(kg[middot][deg]C)).
Tdel,1 = average water outlet temperature measured during
the first draw of the 24-hour simulated use test, [deg]F ([deg]C).
Tin,1 = average water inlet temperature measured during
the first draw of the 24-hour simulated use test, [deg]F ([deg]C).
Qr = the total energy used by the water heater between
cut-out prior to the first draw and cut-out following the first
draw, including auxiliary energy such as pilot lights, pumps, fans,
etc., Btu (kJ). (Electrical auxiliary energy shall be converted to
thermal energy using the following conversion: 1 kWh = 3412 Btu.)
6.2.3 Daily Water Heating Energy Consumption. The daily water
heating energy consumption, Qd, is computed as:
Qd = Q
Where:
Q = Qf + Qe = the energy used by the
instantaneous water heater during the 24-hour simulated use test.
Qf = total fossil fuel energy used by the water heater
during the 24-hour simulated use test, Btu (kJ).
Qe = total electrical energy used during the 24-hour
simulated use test, Btu (kJ).
A modification is needed to take into account that the
temperature difference between the outlet water temperature and
supply water temperature may not be equivalent to the nominal value
of 67 [deg]F (125 [deg]F - 58 [deg]F) or 37.3 [deg]C (51.7 [deg]C -
14.4 [deg]C). The following equations adjust the experimental data
to a nominal 67 [deg]F (37.3 [deg]C) temperature rise.
The energy used to heat water may be computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.048
Where:
N = total number of draws in the draw pattern
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb
(kg)
[[Page 66242]]
Cpi = the specific heat of the water of the ith draw
evaluated at (Tdel,i + Tin,i)/2, Btu/
(lb[middot][deg]F) (kJ/(kg[middot][deg]C)).
Tdel,i = the average water outlet temperature measured
during the ith draw (i = 1 to N), [deg]F ([deg]C).
Tin,i = the average water inlet temperature measured
during the ith draw (i = 1 to N), [deg]F ([deg]C).
[eta]r = as defined in section 6.2.2.
The energy required to heat the same quantity of water over a 67
[deg]F (37.3 [deg]C) temperature rise is:
[GRAPHIC] [TIFF OMITTED] TP04NO13.049
Where:
N = total number of draws in the draw pattern
Mi = the mass withdrawn during the ith draw, lb (kg)
Cpi = the specific heat of water of the ith draw, Btu/
(lb[middot][deg]F) (kJ/(kg[middot][deg]C))
[eta]r = as defined in section 6.2.2.
The difference between these two values is:
QHWD = QHW,67[deg]F - QHW
or QHWD = QHW,37.3[deg]C - QHW
This difference (QHWD) must be added to the adjusted
daily water heating energy consumption value. Thus, the daily energy
consumption value, which takes into account that the temperature
difference between the storage tank and ambient temperature may not
be 57.5 [deg]F (32.0 [deg]C) and that the temperature rise across
the storage tank may not be 67 [deg]F (37.3 [deg]C), is:
Qdm = Qd + QHWD
6.2.4 Energy Factor. The energy factor, Ef, is
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.050
Where:
N = total number of draws in the draw pattern
Qdm = the modified daily water heating energy consumption
as computed in accordance with section 6.2.3, Btu (kJ)
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb
(kg)
Cpi = the specific heat of the water at the ith draw,
evaluated at (125 [deg]F + 58 [deg]F)/2 = 91.5 [deg]F ((51.7 [deg]C
+ 14.4 [deg]C)/2 = 33 [deg]C), Btu/(lb[middot] [deg]F) (kJ/
(kg[middot] [deg]C)).
6.2.5 Annual Energy Consumption. The annual energy consumption
for instantaneous-type water heaters, Eannual, is
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.051
Where:
Ef = the energy factor as computed in accordance with
section 6.2.4
365 = the number of days in a year.
V = the volume of hot water drawn during the applicable draw
pattern, gallons
= 10 for the point-of-use draw pattern
= 38 for the low usage draw pattern
= 55 for the medium usage draw pattern
= 84 for high usage draw pattern
[rho] = 8.24 lbm/gallon, the density of water at 125
[deg]F
CP = 1.00 Btu/lbm [deg]F, the specific heat of
water at 91.5 [deg]F
67 = the nominal temperature difference between inlet and outlet
water
6.2.6 Annual Electrical Energy Consumption. The annual
electrical energy consumption in kilowatt-hours for instantaneous-
type water heaters, Eannual, e, is computed as:
Eannual,e = Eannual*(Qe/Q)/3412
Where:
Qe = the daily electrical energy consumption as defined
in section 6.2.3, Btu (kJ)
Eannual = the annual energy consumption as determined in
accordance with section 6.2.5, Btu (kJ)
Q = total energy used by the water heater during the 24-hour
simulated use test in accordance with section 6.2.3, Btu (kJ)
Qdm = the modified daily water heating energy consumption
as computed in accordance with section 6.2.3, Btu (kJ)
3412 = conversion factor from Btu to kWh
6.2.7 Annual Fossil Fuel Energy Consumption. The annual fossil
fuel energy consumption for instantaneous-type water heaters,
Eannual,f, is computed as:
Eannual,f = Eannual - (Eannual,e x
3412)
Where:
Eannual,e = the annual electrical energy consumption as
defined in section 6.2.6, kWh.
Eannual = the annual energy consumption as defined in
section 6.2.5, Btu (kJ)
3412 = conversion factor from kWh to Btu
[[Page 66243]]
[GRAPHIC] [TIFF OMITTED] TP04NO13.052
[[Page 66244]]
[GRAPHIC] [TIFF OMITTED] TP04NO13.053
[[Page 66245]]
[GRAPHIC] [TIFF OMITTED] TP04NO13.054
[[Page 66246]]
* * * * *
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 energy factor of water heaters shall not be
less than the following for products manufactured on or after the
indicated dates.
----------------------------------------------------------------------------------------------------------------
Energy factor as of Energy factor as of April
Product class Storage volume January 20, 2004 16, 2015
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage Water Heater..... >= 20 gallons and <= 0.67-(0.0019 x Rated For tanks with a Rated
100 gallons. Storage Volume in Storage Volume at or below
gallons). 55 gallons: EF = 0.675-
(0.0015 x Rated Storage
Volume in gallons).
For tanks with a Rated
Storage Volume above 55
gallons: EF = 0.8012-
(0.00078 x Rated Storage
Volume in gallons).
Oil-fired Storage Water Heater..... <= 50 gallons......... 0.59-(0.0019 x Rated EF = 0.68-(0.0019 x Rated
Storage Volume in Storage Volume in
gallons). gallons).
Electric Storage Water Heater...... >= 20 gallons and <= 0.97-(0.00132 x Rated
120 gallons. Storage Volume in
gallons).
For tanks with a Rated
Storage Volume at or below
55 gallons: EF = 0.960-
(0.0003 x Rated Storage
Volume in gallons). For
tanks with a Rated Storage
Volume above 55 gallons:
EF = 2.057-(0.00113 x
Rated Storage Volume in
gallons).
Tabletop Water Heater.............. >= 20 gallons and <= 0.93-(0.00132 x Rated EF = 0.93-(0.00132 x Rated
120 gallons. Storage Volume in Storage Volume in
gallons). gallons).
Instantaneous Gas-fired Water < 2 gallons........... 0.62-(0.0019 x Rated EF = 0.82-(0.0019 x Rated
Heater. Storage Volume in Storage Volume in
gallons). gallons).
Instantaneous Electric Water Heater < 2 gallons........... 0.93-(0.00132 x Rated EF = 0.93-(0.00132 x Rated
Storage Volume in Storage Volume in
gallons). gallons).
----------------------------------------------------------------------------------------------------------------
Note: The Rated Storage Volume equals the water storage capacity of a water heater, in gallons, as certified by
the manufacturer.
Exclusions. The energy conservation standards shown in this
paragraph do not apply to the following types of water heaters: gas-
fired, oil-fired, and electric water heaters at or above 2 gallons
storage volume and below 20 gallons storage volume; gas-fired water
heaters above 100 gallons storage volume; oil-fired water heaters above
50 gallons storage volume; electric water heaters above 120 gallons
storage volume; gas-fired instantaneous water heaters at or below
50,000 Btu/h.
* * * * *
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.
0
12. Section 431.102 is amended by adding the definition of ``Light
commercial water heater,'' in alphabetical order, to read as follows:
Sec. 431.102 Definitions concerning commercial water heaters, hot
water supply boilers, and unfired hot water storage tanks.
* * * * *
Light commercial water heater means any gas-fired, electric, or oil
storage or instantaneous commercial water heater that meets the
following conditions:
(1) For models requiring electricity, uses single-phase external
power supply;
(2) Is not capable of delivering hot water at temperatures of 180
[deg]F or above; and
(3) Does not bear a Code Symbol Stamp signifying compliance with
the requirements of the ASME Boiler and Pressure Vessel Code.
* * * * *
0
13. In Sec. 431.106, paragraph (b), Table 2, is revised to read as
follows:
Sec. 431.106 Uniform test method for the measurement of energy
efficiency of commercial water heaters and hot water supply boilers
(other than commercial heat pump water heaters).
* * * * *
(b) * * *
[[Page 66247]]
Table 2 to Sec. 431.106--Test Procedures for Commercial Water Heaters and Hot Water Supply Boilers
[Other than commercial heat pump water heaters]
----------------------------------------------------------------------------------------------------------------
Use test set-up,
equipment, and Test procedure
Energy efficiency procedures in required for With these additional
Equipment type descriptor subsection compliance on and stipulations
labeled ``Method after
of Test'' of
----------------------------------------------------------------------------------------------------------------
Light Commercial Water Heater.. Energy Factor.... 10 CFR 430, (insert date 365 None.
Subpt. B, App. E. days after
publication of
the final rule
in the Federal
Register that
establishes a
conversion
factor, or
December 31,
2015, whichever
is later).
Gas-fired Storage and Thermal ANSI Z21.10.3- May 13, 2013..... A. For all products,
Instantaneous Water Heaters Efficiency. 2011**, Exhibit ................. the duration of the
and Hot Water Supply Boilers*. ................. G1. May 13, 2013..... standby loss test
Standby Loss..... ANSI Z21.10.3- shall be until
2011**, Exhibit whichever of the
G2. following occurs
first after you begin
to measure the fuel
and/or electric
consumption: (1) The
first cutout after 24
hours or (2) 48
hours, if the water
heater is not in the
heating mode at that
time.
Oil-fired Storage and Thermal ANSI Z21.10.3- May 13, 2013..... B. For oil and gas
Instantaneous Water Heaters Efficiency. 2011**, Exhibit ................. products, the standby
and Hot Water Supply Boilers*. ................. G1. May 13, 2013..... loss in Btu per hour
Standby Loss..... ANSI Z21.10.3- must be calculated as
2011**, Exhibit follows: SL (Btu per
G2. hour) = S (% per
hour) x 8.25 (Btu/gal-
F) x Measured Volume
(gal) x 70 (degrees
F).
Electric Storage and Standby Loss..... ANSI Z21.10.3- May 13, 2013..... C. For oil-fired
Instantaneous Water Heaters. 2011**, Exhibit products, apply the
G2. following in
conducting the
thermal efficiency
and standby loss
tests: (1) Venting
Requirements--Connect
a vertical length of
flue pipe to the flue
gas outlet of
sufficient height so
as to meet the
minimum draft
specified by the
manufacturer. (2) Oil
Supply--Adjust the
burner rate so that:
(a) The hourly Btu
input rate lies
within 2
percent of the
manufacturer's
specified input rate,
(b) the CO2 reading
shows the value
specified by the
manufacturer, (c)
smoke in the flue
does not exceed No. 1
smoke as measured by
the procedure in ASTM-
D-2156-80, and (d)
fuel pump pressure
lies within 10 percent of
manufacturer's
specifications.
D. For electric
products, apply the
following in
conducting the
standby loss test:
(1) Assume that the
thermal efficiency
(Et) of electric
water heaters with
immersed heating
elements is 98
percent. (2) Maintain
the electrical supply
voltage to within
5 percent
of the center of the
voltage range
specified on the
water heater
nameplate. (3) If the
set up includes
multiple adjustable
thermostats, set the
highest one first to
yield a maximum water
temperature in the
specified range as
measured by the
topmost tank
thermocouple. Then
set the lower
thermostat(s) to
yield a maximum mean
tank temperature
within the specified
range.
E. Install water-tube
water heaters as
shown in Figure 2,
``Arrangement for
Testing Water-tube
Type Instantaneous
and Circulating Water
Heaters.''
----------------------------------------------------------------------------------------------------------------
* As to hot water supply boilers with a capacity of less than 10 gallons, these test methods become mandatory on
October 21, 2005. Prior to that time, you may use for these products either (1) these test methods if you rate
the product for thermal efficiency, or (2) the test methods in Subpart E if you rate the product for
combustion efficiency as a commercial packaged boiler.
** Incorporated by reference, see Sec. 431.105.
0
14. Section 431.107 is added to read as follows:
Sec. 431.107 Uniform test method for the measurement of energy
efficiency of commercial heat pump water heaters.
[[Page 66248]]
Table 1 to Sec. 431.107--Test Procedures for Commercial Heat Pump Water Heaters
----------------------------------------------------------------------------------------------------------------
Use test set-up,
equipment, and
Equipment type Energy efficiency procedures in Test procedure required for
descriptor subsection labeled compliance on and after
``Method of Test'' of
----------------------------------------------------------------------------------------------------------------
Light Commercial Heat Pump Water Energy Factor......... 10 CFR 430, Subpt. B, (insert date 365 days after
Heater with Integrated Storage App. E. publication of the final
Tank. rule in the Federal
Register that establishes
a conversion factor, or
December 31, 2015,
whichever is later)
All Other Types.................... [Reserved]............ [Reserved]............ [Reserved]
----------------------------------------------------------------------------------------------------------------
[FR Doc. 2013-26268 Filed 11-1-13; 8:45 am]
BILLING CODE 6450-01-P