```

[Federal Register Volume 79, Number 133 (Friday, July 11, 2014)]
[Rules and Regulations]
[Pages 40541-40588]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-15656]

[[Page 40541]]

Vol. 79

Friday,

No. 133

July 11, 2014

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; Final Rule

Federal Register / Vol. 79 , No. 133 / Friday, July 11, 2014 / Rules 
and Regulations

[[Page 40542]]

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DEPARTMENT OF ENERGY

10 CFR Parts 429, 430, and 431

[Docket No. 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: Final rule.

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SUMMARY: On November 4, 2013, the U.S. Department of Energy (DOE) 
issued a notice of proposed rulemaking (NOPR) to amend its test 
procedures established under the Energy Policy and Conservation Act for 
residential water heaters and certain commercial water heaters, which 
serves as the basis for today's action. This rulemaking fulfills 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 satisfies 
DOE's statutory obligation to develop a uniform efficiency descriptor 
for residential and commercial water heaters. The test method applies 
the same efficiency descriptor to all residential and certain 
commercial water heaters, and extends coverage to eliminate certain 
gaps in the current residential test procedure, updates the simulated-
use-test draw pattern, and updates the outlet water temperature 
requirement.

DATES: The effective date of this rule is July 13, 2015. Compliance 
will be mandatory starting one year after the publication in the 
Federal Register of a mathematical conversion factor to convert from 
the existing efficiency ratings to efficiency ratings under the test 
procedure adopted by this final rule, or December 31, 2015, whichever 
is later.
    The incorporation by reference of certain publications listed in 
this rule is approved by the Director of the Federal Register as of 
July 13, 2015. Other publications referenced were approved on March 23, 
2009, and May 16, 2012.

ADDRESSES: The docket for this rulemaking is available for review at 
www.regulations.gov, 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 
www.regulations.gov index. However, not all documents listed in the 
index may be publicly available, such as information that is exempt 
from public disclosure.
    A link to the docket on the www.regulations.gov Web page can be 
found at: http://www.regulations.gov/#!docketDetail;D=EERE-2011-BT-TP-
0042. The www.regulations.gov Web page contains simple instructions on 
how to access all documents, including public comments, in the docket.
    For further information on how to review the docket, contact Ms. 
Brenda Edwards at (202) 586-2945 or by email: 
Brenda.Edwards@ee.doe.gov.

FOR FURTHER INFORMATION CONTACT: Ms. Ashley Armstrong, U.S. Department 
of Energy, Office of Energy Efficiency and Renewable Energy, Building 
Technologies Office, EE-5B, 1000 Independence Avenue SW., Washington, 
DC 20585-0121. Telephone: (202) 586-6590. Email: 
Ashley.Armstrong@ee.doe.gov.
    Mr. Eric Stas, U.S. Department of Energy, Office of the General 
Counsel, GC-71, 1000 Independence Avenue SW., Washington, DC 20585-
0121. Telephone: (202) 586-9507. Email: Eric.Stas@hq.doe.gov.

SUPPLEMENTARY INFORMATION: This final rule incorporates by reference 
the following industry standards into subpart B of 10 CFR part 430:
    ASTM D2156-09, (``ASTM D2156''), Standard Test Method for Smoke 
Density in Flue Gases from Burning Distillate Fuels.
    Copies of ASTM D2156-09 can be obtained from the American Society 
for Testing and Materials International, 100 Barr Harbor Drive, P.O. 
Box C700, West Conshohocken, PA 19428-2959, or go to http://www.astm.org.

Table of Contents

I. Authority and Background
II. Summary of the Final Rule
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, Gas-Fired Heat Pump 
Water Heaters, and Oil-Fired Instantaneous Water Heaters
    B. Uniform Efficiency Descriptor Nomenclature
    C. Draw Pattern
    D. Instrumentation
    E. Test Conditions
    1. Outlet Water Temperature
    2. Ambient Temperature and Relative Humidity
    3. Laboratory Airflow
    F. Storage Tank Pre-Conditioning
    G. Operational Mode Selection
    H. Annual Energy Consumption Calculation
    I. Conversion of Existing Energy Factor Ratings
    J. Full Fuel Cycle
    K. Certification, Compliance, and Enforcement IssuesC
    1. Storage Volume Requirements
    2. First-Hour Rating and Maximum GPM Requirements
    3. Ratings for Untested Models
    L. Reference Standards
    M. Compliance With Other EPCA Requirements
    N. Other Issues
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Order 12866
    B. Review Under the Regulatory Flexibility Act
    C. Review Under the Paperwork Reduction Act of 1995
    D. Review Under the National Environmental Policy Act of 1969
    E. Review Under Executive Order 13132
    F. Review Under Executive Order 12988
    G. Review Under the Unfunded Mandates Reform Act of 1995
    H. Review Under the Treasury and General Government 
Appropriations Act, 1999
    I. Review Under Executive Order 12630
    J. Review Under Treasury and General Government Appropriations 
Act, 2001
    K. Review Under Executive Order 13211
    L. Review Under Section 32 of the Federal Energy Administration 
Act of 1974
    M. Congressional Notification
V. 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 this 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))
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    \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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    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

[[Page 40543]]

consist of test procedures that manufacturers of covered products and 
equipment must use as the basis for certifying to DOE that their 
products and equipment comply with the applicable energy conservation 
standards adopted 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, ``Energy 
Standard for Buildings Except Low-Rise Residential Buildings,'' is 
updated, DOE must amend its test procedure to be consistent with the 
updated test procedure 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 to 
what extent, if any, 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 DOE must review test procedures for 
all covered products at least once every seven years 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 (seven years after the 
enactment of EISA 2007), and DOE must review the test procedures for 
commercial water heaters not later than May 16, 2019 (seven years after 
the last final rule for commercial water heater test procedures \4\). 
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.
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    \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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    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 consumer 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 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, 74561-62. 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 other issues regarding DOE's existing test procedure for 
residential water heaters. DOE addresses these issues in this final 
rule.
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    \5\ For more information, please visit DOE's Web site at: http://www1.eere.energy.gov/buildings/appliance_standards/residential/waterheaters.html.
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    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. Key issues discussed in the RFI include the 
scope, draw patterns, and test conditions for residential water 
heaters. The RFI began the process of fulfilling DOE's obligation to 
periodically review its test procedures under 42 U.S.C. 6293(b)(1)(A) 
by initiating a rulemaking to examine all aspects of the DOE test 
procedure.
    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

[[Page 40544]]

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 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, including: (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))
    On January 11, 2013, DOE published in the Federal Register an RFI 
(hereinafter the ``January 2013 RFI'') that requested comment on its 
interpretation of the requirements for developing a uniform efficiency 
descriptor in AEMTCA. DOE also sought comment on how to implement those 
requirements. 78 FR 2340. DOE accepted comments and information on the 
RFI until February 11, 2013.
    On November 4, 2013, DOE published a NOPR in the Federal Register 
(hereinafter the ``November 2013 NOPR'') regarding the test procedure 
for residential and certain commercial water heaters. DOE accepted 
comments and information on the NOPR until January 21, 2014. The 
November 2013 NOPR proposed to modify the current test procedures for 
residential water heaters and certain commercial water heaters to be 
more representative of conditions encountered in the field (including 
modifications to both the test conditions and the draw patterns) and to 
expand the scope of the test procedure to apply to certain commercial 
water heaters and certain residential water heaters that are not 
covered by the current test procedure. The proposal also included a 
number of other improvements identified by commenters in response to 
both the October 2011 RFI and the January 2013 RFI. On December 6, 
2013, DOE held a public meeting to discuss the test procedure proposals 
outlined in the November 2013 NOPR. The feedback received from 
stakeholders was taken into consideration and is discussed further in 
section III of this final rule.

II. Summary of the Final Rule

    Through this final rule, DOE amends its test procedure for 
residential water heaters and certain commercial water heaters. The 
amendments will modify the test procedure to be more representative of 
conditions encountered in the field (including modifications to 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 not covered by the current test 
procedure. The following paragraphs summarize these changes.
    DOE also modifies 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 current test procedure); 
and (2) to certain commercial water heaters that have residential 
applications. These modifications include the 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 
creation of a definition for ``electric instantaneous water heater.'' 
In addition, DOE establishes a new equipment class of commercial water 
heaters and corresponding definition for ``residential-duty commercial 
water heater.'' DOE will require water heaters that are classified as 
``residential-duty commercial'' to be tested using the test procedure 
for the uniform efficiency descriptor established in this final rule.
    In addition, DOE establishes the use of multiple draw patterns for 
testing water heaters, with certain draw patterns prescribed as a 
function of equipment capacity. Further, DOE establishes updates to the 
water heater draw pattern to be more reflective of actual field usage 
based on recent field test data. Lastly, DOE modifies the outlet water 
temperature requirement to better reflect conditions encountered in 
typical field installations.

III. Discussion

    In response to the November 2013 NOPR, DOE received 24 written 
comments from the following interested parties: Thomas Harman, Seisco, 
Applied Energy Technology (AET), two separate comments from Heat 
Transfer Products, Inc. (HTP), the National Propane Gas Association 
(NPGA), Bradford White, A.O. Smith, Edison Electric Institute (EEI), a 
joint comment from Northwest Energy Efficiency Alliance (NEEA) and 
Northwest Power and Conservation Council (NPCC) (NEEA and NPCC), 
Sequentric Energy Systems, LLC (SES), Stone Mountain Technologies 
(SMT), six separate comments from Affiliated International Management, 
LLC (AIM), the American Gas Association (AGA), Rheem Manufacturing 
Company (Rheem), the Air-Conditioning, Heating, and Refrigeration 
Institute (AHRI), Giant Factories, Inc. (Giant), a joint comment 
submitted by the American Council for an Energy-Efficient Economy 
(ACEEE) (Joint Comment),\6\ and General Electric Company (GE).
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    \6\ ACEEE submitted a joint comment on behalf of ACEEE, the 
Appliance Standards Awareness Project (ASAP), the Alliance to Save 
Energy (ASE), Consumers Union (CU), the National Consumer Law Center 
(NCLC), the Natural Resources Defense Council (NRDC), and the 
Northeast Energy Efficiency Partnership (NEEP).
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    These interested parties commented on a range of issues, including 
those identified by DOE in the October 2011 RFI, the January 2013 RFI, 
and the November 2013 NOPR, as well as several other pertinent issues. 
The issues on which DOE received comment, as well as DOE's response to

[[Page 40545]]

those comments and the resulting changes to the test procedures for 
water heaters, are discussed in the subsections immediately below.

A. Scope

    DOE's current 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 current 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). In the 
NOPR, DOE proposed an expansion of the scope of coverage of its test 
method so that it applies to all products that meet the definition of 
residential water heater, including those products listed above that 
are not addressed by the existing DOE test method. 78 FR 66202, 66205 
(Nov. 4, 2013). DOE also proposed revising 10 CFR 430.32(d) to clarify 
the applicability of the existing standards with respect to the 
expanded test procedure scope. Id. As discussed below, DOE adopts the 
proposed changes along with several clarifications based on comments 
received from interested parties.
    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. Models 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, by this 
final rule, DOE establishes 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 expands the 
scope of the test procedure to include test methods for certain product 
types that are not covered by the current DOE test procedure. DOE 
identified these topics as issues for comment in the October 2011 RFI, 
the January 2013 RFI, and the November 2013 NOPR. 76 FR 63211, 63212-13 
(Oct. 12, 2011); 78 FR 2340, 2344-2346 (Jan. 11, 2013); 78 FR 66202, 
66205-66224 (Nov. 4, 2013).
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    \7\ As provided by 42 U.S.C. 6295(e)(5)(F), DOE is excluding 
from the uniform efficiency descriptor certain commercial water 
heaters that do not have a residential use, 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 excluding are discussed further in section III.A.1.
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1. Coverage Range of Uniform Metric and Test Procedure
    As proposed in the November 2013 NOPR, and in accordance with 
AEMTCA (42 U.S.C. 6295(e)(5)(F)), DOE excludes from the uniform 
efficiency 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. In the November 2013 NOPR, DOE 
proposed to define a new classification of commercial water heaters for 
which the uniform efficiency descriptor would apply, which DOE believes 
can be clearly distinguished from the commercial water heaters for 
which the uniform descriptor would not apply under this final rule; DOE 
proposed to name the new classification ``light commercial water 
heater.'' 78 FR 66202, 66206 (Nov. 4, 2013). DOE received 4 comments on 
this proposal in response to the NOPR. AHRI, AIM, A.O. Smith, and NEEA 
and NPCC suggested that the proposed name could lead to confusion. 
(AHRI, No. 75 at p. 2; AIM, No. 67 at p. 1; A.O. Smith, No. 62 at p. 1; 
NEEA and NPCC No. 64 at p. 3).\8\ Further, AHRI and A.O. Smith 
suggested that a more appropriate name for this product classification 
would be ``residential-duty water heater.'' (AHRI, No. 75 p. 2; A.O. 
Smith, No. 62 at p. 1) DOE considered this comment and agrees that 
``light commercial'' is a term already used in industry and that using 
this term in this context could cause stakeholder and consumer 
confusion. Thus, DOE adopts a new name for the classification, as 
suggested by commenters, and creates a ``residential-duty'' commercial 
water heater classification.\9\
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    \8\ All references to comments received in response to the 
November 2013 NOPR identify the commenter, the identification number 
applied by DOE, and the page of the comment package on which the 
particular point has been discussed.
    \9\ As discussed in the NOPR, DOE determined that the current 
metrics for commercial water heaters that are used only in 
commercial settings (i.e., non-``residential-duty'' commercial water 
heaters) are appropriate and adequate to characterize the 
performance of such commercial water heaters due to the typical 
operating patterns of such equipment. 78 FR 66202, 66206 (Nov. 4, 
2013).
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    In the November 2013 NOPR, DOE proposed three characteristics to 
distinguish water heaters intended only for commercial use: (1) For 
models requiring electricity, uses three-phase power supply; (2) is 
capable of delivering hot water at temperatures of 180[emsp14][deg]F or 
above; and/or (3) bears a Code Symbol Stamp signifying compliance with 
the requirements of the American Society of Mechanical Engineers (ASME) 
Boiler and Pressure Vessel Code. DOE did not propose input and storage 
capacity criteria to differentiate commercial water heaters that would 
only be used in non-residential applications from commercial water 
heaters that could have residential applications, given that changes to 
the input and storage capacity criteria would likely occur over time 
and require updating. 78 FR 66202, 66206-66207 (Nov. 4, 2013).
    No comments were received opposing the proposal to exclude from the 
``residential-duty commercial water heater'' classification any water 
heater which uses three-phase power, so DOE has decided to retain that 
characteristic in this final rule.
    Five comments (AHRI, A.O. Smith, Bradford White, Giant, Joint 
Comment) requested that the language ``capable of delivering'' water at 
180[emsp14][deg]F or more should be changed to ``designed to deliver,'' 
given that the delivery temperature of a water heater is a result of 
the field conditions and usage. These commenters also pointed out that 
even a water heater that is not designed to deliver water at or above 
180[emsp14][deg]F might be capable of doing so. (AHRI, No. 75 at pp. 1-
2; A.O. Smith, No. 62 at p. 5; Bradford White, No. 61 at pp. 2-3; 
Giant, No. 76 at p. 1; Joint Comment, No. 77 at p. 5)
    Four commenters (AHRI, A.O. Smith, Giant, Joint Comment) stated 
that the ASME Boiler and Pressure Vessel Stamp is not required in all 
jurisdictions and would not adequately classify a water heater as a 
commercial water heater

[[Page 40546]]

without a residential application. (AHRI, No. 75 at p. 2; A.O. Smith, 
No. 62 at p. 4; Giant, No. 76 at p. 1; Joint Comment, No. 77 at p. 5)
    Nine comments (AHRI, A.O. Smith, EEI, Giant, NEEA and NPCC, Joint 
Comment, Rheem, SMT, Seisco) suggested the addition of input and 
storage capacity criteria, stating that the three criteria listed above 
do not adequately distinguish water heaters not intended for 
residential use. (AHRI, No. 75 at p. 2; A.O. Smith, No. 62 at p. 4; 
EEI, No. 63 at p. 5; Giant, No. 76 at pp. 1-2; NEEA and NPCC, No. 64 at 
p. 3; Joint Comment, No. 77 at p. 4; Rheem, No. 69 at p. 2; SMT, No. 66 
at p. 1; Seisco, No. 57 at p. 11) The suggested criteria are presented 
in Table III.1 and are grouped by water heater type.

  Table III.1--Suggested Capacity Criteria for Defining Non-Residential
                              Water Heaters
------------------------------------------------------------------------
                                          Indicator of non-residential
           Water heater type                application by commenter
------------------------------------------------------------------------
Gas-fired Storage.....................  AHRI, A.O. Smith, Giant, Rheem:
                                         Rated input >100 kBtu/h; Rated
                                         storage volume >100 gallons.
Oil-fired Storage.....................  AHRI, A.O. Smith, Giant, Rheem:
                                         Rated input >140 kBtu/h; Rated
                                         storage volume >50 gallons.
                                        NEEA and NPCC: Rated input >105
                                         kBtu/h; Rated storage volume
                                         >120 gallons.
Electric Storage......................  AHRI, A.O. Smith, Giant, Rheem:
                                         Rated input >12kW; Rated
                                         storage volume >120 gallons.
                                        NEEA and NPCC: Rated input
                                         >12kW; Rated storage volume 120 gallons.
Heat Pump with Storage................  AHRI, A.O. Smith, Giant, Rheem:
                                         Rated current >24 A at a rated
                                         voltage of not greater than 250
                                         V; Rated storage volume >120
                                         gallons.
                                        NEEA and NPCC; Rated Input >15
                                         kW; Rated current >24 A at a
                                         rated voltage of not greater
                                         than 250 V; Rated storage
                                         volume >120 gallons.
Gas-fired Instantaneous...............  AHRI, A.O. Smith, Giant, Rheem:
                                         Rated input >200 kBtu/h; Rated
                                         storage volume h of input.
                                        NEEA and NPCC: Rated input >200
                                         kBtu/h; Rated storage volume 25 kW; Rated
                                         storage volume >2 gallons.
                                        NEEA and NPCC: Rated input >58.6
                                         kW; Rated storage volume >2
                                         gallons.
                                        Siesco: Rated input >56 kW (at a
                                         minimum).
Oil-fired Instantaneous...............  AHRI, A.O. Smith, Giant, Rheem:
                                         Rated input >210 kBtu/h; Rated
                                         storage volume >2 gallons.
------------------------------------------------------------------------

    Upon considering these comments, DOE decided to modify the criteria 
for distinguishing water heaters intended only for non-residential, 
commercial use. First, upon examining the commercial water heaters 
available on the market, DOE found that many water heaters that are 
marketed for residential applications and would otherwise be classified 
as ``residential-duty'' would be exempted from coverage under the 
uniform efficiency descriptor because of the requirement that 
``residential-duty'' units be capable of delivering water at 
temperatures only up to 180[emsp14][deg]F. (In the November 2013 NOPR, 
DOE proposed that ``residential-duty'' units would be capable of 
delivery water temperature up to but not including 180[emsp14][deg]F. 
78 FR 66202, 66246 (Nov. 4, 2013).) As stated in section I, AEMTCA 
requires that the test method apply, to the maximum extent practicable, 
to all water-heating technologies currently in use (42 U.S.C. 
6295(e)(5)(H)), except for specific categories of 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)). DOE believes that the proposed 
criteria to distinguish water heaters intended only for commercial use 
based on the capability to deliver hot water at temperatures of 
180[emsp14][deg]F or above would have inappropriately excluded 
commercial water heaters marketed for residential applications, because 
such models are designed to include 180[emsp14][deg]F as the maximum 
delivery temperature. However, DOE believes that including 
180[emsp14][deg]F as the maximum delivery temperature of ``residential-
duty'' commercial water heaters is still a valuable distinguishing 
feature between water heaters intended for residential use and those 
that are not.
    DOE also agrees with commenters to adjust the language of the 
180[emsp14][deg]F delivery temperature criteria to read ``designed to 
deliver'' as opposed to ``capable of delivering,'' because a water 
heater that is ``designed to deliver'' hot water at or below 
180[emsp14][deg]F might be capable of delivering hot water in excess of 
180[emsp14][deg]F depending on the field conditions and usage. DOE is 
aware of situations where a water heater could be subjected to a series 
of several short draws, which can cause an influx of cold water at the 
bottom of the tank. Due to stratification, the water at the bottom of 
the tank near the thermostat may be colder than the water at the top of 
the tank, causing the burner or elements to turn on and heat the water 
to a temperature above that for which the water heater is designed. DOE 
considers a water heater that is ``designed to deliver'' water at or 
below 180[emsp14][deg]F as one that has a user-operable temperature 
control device with a maximum setting of 180[emsp14][deg]F or a maximum 
setting that would deliver water at or below 180[emsp14][deg]F under 
the conditions defined by the test method. In order to more closely 
match the language of the test procedure when defining water heaters, 
DOE is slightly changing the wording from ``designed to deliver water'' 
to ``designed to provide outlet water.''
    Second, because the ASME Boiler and Pressure Vessel Stamp criterion 
is not required in all jurisdictions and because this criterion is not 
a definitive identifier of whether a unit is truly commercial, DOE does 
not adopt this proposed requirement. Rather, as suggested by 
commenters, DOE adopts limitations on input rating and storage 
capacity. (Additional comments related to storage capacity and input 
capacity limitations are discussed in the subsections immediately 
following this section.) DOE agrees that water-heating units exist in 
the current marketplace that are not intended for residential use that 
do not meet the three criteria proposed in the November 2013 NOPR (and 
listed above) and, thus, establishes input and storage capacity 
criteria based on water heater type as shown in Table III.2. Although 
DOE still believes that changes to the input and storage capacity 
criteria could occur over time and require these criteria to be 
updated, DOE has concluded that these criteria are necessary to 
properly classify the scope of the uniform efficiency descriptor.

[[Page 40547]]

    Table III.2--Capacity Criteria for Defining Non-Residential Water
                                 Heaters
------------------------------------------------------------------------
                                           Indicator of non-residential
           Water heater type                       application
------------------------------------------------------------------------
Gas-fired Storage......................  Rated input >105 kBtu/h; Rated
                                          storage volume >120 gallons.
Oil-fired Storage......................  Rated input >140 kBtu/h; Rated
                                          storage volume >120 gallons.
Electric Storage.......................  Rated input >12 kW; Rated
                                          storage volume >120 gallons.
Heat Pump with Storage.................  Rated input >15 kW; Rated
                                          current >24 A at a rated
                                          voltage of not greater than
                                          250 V; Rated storage volume
                                          >120 gallons.
Gas-fired Instantaneous................  Rated input >200 kBtu/h; Rated
                                          storage volume >2 gallons.
Electric Instantaneous.................  Rated input >58.6 kW; Rated
                                          storage volume >2 gallons.
Oil-fired Instantaneous................  Rated input >210 kBtu/h; Rated
                                          storage volume >2 gallons.
------------------------------------------------------------------------

    DOE establishes a definition of ``residential-duty commercial water 
heater'' at 10 CFR 431.102 that defines a ``residential-duty commercial 
water heater'' as 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 designed to provide outlet hot water at temperatures 
greater than 180[emsp14][deg]F; and
    (3) Is not excluded by the specified limitations regarding rated 
input and storage volume as described in Table III.2 above.
    Although residential-duty commercial water heaters could have 
residential applications, DOE notes that the new ``residential-duty 
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 will continue to be subject to the 
applicable energy conservation standards in 10 CFR part 431 and the 
certification requirements for commercial and industrial equipment in 
10 CFR part 429. Similarly, although DOE recognizes that some consumer 
water heaters may be installed in a commercial setting, those water 
heaters are covered consumer products for the purposes of DOE 
regulations; the applicable energy conservation standards in 10 CFR 
part 430 continue to apply; and they must be certified as consumer 
products under 10 CFR part 429.
    If a commercial water heater does not meet all of the three 
conditions discussed above, 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 and the certification requirements for 
commercial and industrial equipment in 10 CFR part 429. If a commercial 
water heater meets all three criteria, DOE will consider it a 
``residential-duty commercial water heater,'' which would be subject to 
the uniform efficiency descriptor and test method established in this 
final rule. Accordingly, DOE is adding 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 type of equipment.
    As stated in the November 2013 NOPR, DOE has determined that 
certain commercial equipment, including unfired storage tanks, add-on 
heat pump water heaters, and hot water supply boilers, are not 
appropriately rated using the uniform descriptor applicable to other 
water heaters. 78 FR 66202, 66207 (Nov. 4, 2013). Unfired storage tanks 
are not complete water-heating systems and require additional equipment 
in the field to operate. As such, their performance as part of a 
complete water-heating system is dependent upon other components of the 
system so that use of the uniform descriptor may be unrepresentative of 
its performance as part of a complete water-heating system. In a 
similar vein, DOE previously determined that residential add-on heat 
pump water heaters are not covered residential products. 75 FR 20112, 
20127 (Apr. 16, 2010). DOE has authority to cover commercial add-on 
heat pumps; however, this equipment does not have residential 
applications and, therefore, is not suitable for application of the 
uniform efficiency descriptor. DOE also 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 their use is similar to that of other commercial water 
heaters in commercial applications. 78 FR 66202, 66207 (Nov. 4, 2013). 
DOE will address the types of commercial 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. DOE did not receive any comments 
regarding the exclusion of unfired storage tanks, add-on heat pump 
water heaters, and hot water supply boilers from coverage under the 
uniform descriptor.
2. Storage Capacity Limits
    As noted above, 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). 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.
    The definitions in the current DOE test procedure specify that gas 
instantaneous 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 definitions for ``Electric Instantaneous Water Heater'' 
and ``Storage-type Water Heater of More than 2 Gallons (7.6 Liters) and 
Less than 20 Gallons (76 Liters)'' are currently reserved. Id. at 
section 1.12.5.
    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 necessary to determine an appropriate 
representative daily hot water consumption for water heaters with these 
storage volumes 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.
    As proposed in the November 2013 NOPR, DOE has decided to expand 
the scope of the water heater test procedure for the uniform efficiency 
descriptor to

[[Page 40548]]

include water heaters with storage volumes between 2 and 20 gallons. 78 
FR 66202, 66208 (Nov. 4, 2013). Rheem supported the expansion of the 
scope to include units between 2 and 20 gallons, but asserted that 
these products should not be covered by the current energy conservation 
standards. (Rheem, No. 69 at pp. 7-8) Bradford White requested 
clarification as to whether products between 2 and 20 gallons would be 
covered by the current energy conservation standards or test procedure 
only. (Bradford White, No. 61 at p. 2) AHRI stated that, although DOE 
is developing a test method for water heaters with storage volumes 
between 2 and 20 gallons, the current DOE minimum efficiency standards 
for residential water heaters do not and should not apply to models 
having rated storage volumes less than 20 gallons, and AHRI requested 
information regarding DOE activities with regard to standards for these 
products. (AHRI, No. 80 at pp. 2-3)
    The test procedure modifications for water heaters with a storage 
volume between 2 and 20 gallons specify the method of test set-up 
(including instrumenting such water heaters), a test method to assess 
the delivery capacity, and the draw pattern to be used to determine the 
energy efficiency of such units. The amendments for water heaters with 
storage volumes between 2 and 20 gallons are discussed in detail in 
section III.C of this final rule. Currently, there are no minimum 
energy conservation standards applicable to water heater products with 
a storage volume between 2 and 20 gallons, which will be the case until 
DOE conducts a rulemaking to establish such standards. DOE clarifies 
this point in this final rule's amendments to 10 CFR 430.32(d).
    AEMTCA requires DOE to reconsider the scope of all water heater 
test procedures. AEMTCA amended EPCA to require that the new uniform 
metric apply to the extent possible to all water-heating technologies. 
(42 U.S.C. 6295(e)(5)(F) and (H))
    In considering the upper limit to the storage capacity range, 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. AHRI, A.O. Smith, Giant, and Rheem supported the continued 
use of the current maximum storage capacity limits. (AHRI, No. 75 at p. 
2; A.O. Smith, No. 62 at p. 4; Giant, No. 76 at p. 2; Rheem, No. 69 at 
p. 2)
    In contrast, as AET stated in response to the January 2013 RFI, the 
ASME Boiler and Pressure Vessel Code 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, No. 22 at pp. 6-7)
    DOE has reconsidered the water heater test procedure scope and 
expands the scope of the test procedure to include all covered water 
heaters that could have residential applications and adjusts the 
current limitations on maximum storage volume in the residential test 
procedure for gas-fired, electric, and oil storage water heaters to 120 
gallons for all three types. DOE concludes that the amended test method 
adopted in today's final rule adequately addresses water heaters 
regardless of storage volume, provided that they meet the definition of 
a ``residential water heater'' or a ``residential-duty commercial water 
heater.'' Consequently, DOE's uniform descriptor test procedure will 
apply to residential storage water heaters and ``residential-duty 
commercial water heaters'' with storage volumes up to 120 gallons. As 
noted previously in section III.A.1, DOE excludes non-residential 
(commercial) water heaters, and DOE agrees with AET that a storage 
capacity limit of 120 gallons adequately separates residential and 
commercial units of all water heater types.
3. Input Capacity Limits
    AEMTCA requires that the new uniform efficiency descriptor apply to 
the maximum extent practical to all water-heating technologies in use 
now or in the future. (42 U.S.C. 6295(e)(5)(H)) 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 existing 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, appendix E, section 
1.12.
    In the November 2013 NOPR, DOE proposed to eliminate the minimum 
limit on the firing rate of instantaneous gas water heaters of 50,000 
Btu/h. 78 FR 66202, 66209 (Nov. 4, 2013). As discussed in section 
III.C, DOE adopts multiple draw patterns that vary based on the 
delivery capacity of the water heater. Because the draw pattern is 
dependent upon delivery capacity, gas-fired instantaneous units with a 
firing rate below 50,000 Btu/h can be tested under the new procedure. 
Thus, DOE has concluded that there is no reason to retain this lower 
limit on gas-fired instantaneous water heater delivery capacity. No 
comments were received opposing this measure.
    Similarly, DOE proposed 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 (although 
maximum input ratings specified in EPCA would still apply for the 
purposes of equipment classification). Because draw patterns vary based 
on delivery capacity, the new test procedure applies to models with 
input capacities above those included in the current residential water 
heater test procedure. Although these maximum input limitations were 
based upon EPCA's ``water heater'' definition at 42 U.S.C. 6291(27), 
because the AEMTCA amendments require 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. 
DOE did not receive any comments in response to the NOPR related 
specifically to the inclusion of input limitations on residential 
products in the test procedure, but did receive comments regarding the 
application of the test procedure to commercial models and suggesting 
input capacity limitations. Those comments are discussed in section 
III.A.1. As discussed in section III.A.1, input rating limitations are 
useful to distinguish water heaters without a residential use. 
Therefore, although DOE will remove the input capacity limitations from 
the scope of the test method, DOE establishes input capacity limits to 
define which units would qualify as ``residential-duty'' commercial 
units and, thus, be required to be tested using the uniform descriptor 
test method. These input capacity limitations are shown in Table III.2 
above.

[[Page 40549]]

4. Electric Instantaneous Water Heaters, Gas-Fired Heat Pump Water 
Heaters, and Oil-Fired Instantaneous Water Heaters
    As discussed in the November 2013 NOPR, DOE's 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). 78 FR 66202, 66209 (Nov. 4, 
2013). EPCA defines ``electric instantaneous water heater'' as 
containing no more than one gallon of water per 4,000 Btu per hour of 
input and having an input capacity of 12 kilowatts (kW) or less. (42 
U.S.C. 6291(27)(B)) As noted in the November 2013 NOPR, the heating 
power required for electric instantaneous water heaters intended for 
whole-home applications typically is much higher than the power 
capability commonly found in storage-type electric water heaters. 78 FR 
66202, 66209 (Nov. 4, 2013). In the November 2013 NOPR, DOE proposed to 
amend its water heater test procedure to include applicable provisions 
for electric instantaneous water heaters, and to define the term 
``electric instantaneous water heater.'' Id. at 66210.
    AIM commented that DOE needs to be more inclusive of all types of 
water heaters when defining the types of water heaters that will be 
covered by the uniform descriptor. (AIM No. 70 at p. 2)
    DOE agrees in principle that all existing types of water heaters 
should be defined and, thus, adopts definitions of ``gas-fired heat 
pump water heater'' and ``oil-fired instantaneous water heater,'' in 
addition to a definition for ``electric instantaneous water heater.'' 
While not yet commercially available, DOE is aware that manufacturers 
are currently developing gas-fired heat pump water heaters and oil-
fired instantaneous water heaters. Further, the new test procedure 
applies to these types of water heaters. Accordingly, DOE adds 
definitions for these types of water heaters at 10 CFR 430.2. (In 
addition, as proposed in the November 2013 NOPR, DOE is moving all 
other definitions pertaining to defining the types of water heaters to 
10 CFR 430.2.) All three definitions reflect the definitions of these 
products as set forth in EPCA (42 U.S.C. 6291(27)) and are based on the 
current definitions for other types of water heaters. The definition 
for ``electric instantaneous water heater'' has been altered slightly 
from the definition proposed in the November 2013 NOPR to better align 
with the requirements of EPCA for these products. These definitions 
read as follows:
    Gas-fired Heat Pump Water Heater means a water heater that uses gas 
as the main energy source, has a nameplate input rating of 75,000 Btu/h 
(79 MJ/h) or less, has a maximum current rating of 24 amperes 
(including all auxiliary equipment such as fans, pumps, controls, and, 
if on the same circuit, any resistive elements) at an input voltage of 
no greater than 250 volts, has a rated storage capacity of 120 gallons 
(450 liters) or less, and is designed to transfer thermal energy from 
one temperature level to a higher temperature level to deliver water at 
a thermostatically-controlled temperature less than or equal to 
180[emsp14][deg]F (82 [deg]C).
    Oil-fired Instantaneous Water Heater means a water heater that uses 
oil as the main energy source, has a nameplate input rating of 210,000 
Btu/h (220 MJ/h) or less, contains no more than one gallon of water per 
4,000 Btu per hour of input, and is designed to provide outlet water at 
a controlled temperature less than or equal to 180[emsp14][deg]F (82 
[deg]C). The unit may use a fixed or variable burner input.
    Electric Instantaneous Water Heater means a water heater that uses 
electricity as the energy source, has a nameplate input rating of 12 kW 
(40,956 Btu/h) or less, contains no more than one gallon of water per 
4,000 Btu per hour of input, and is designed to provide outlet water at 
a controlled temperature less than or equal to 180[emsp14][deg]F (82 
[deg]C). The unit may use a fixed or variable burner input.
    DOE notes that the definition of ``electric instantaneous water 
heater'' being added to 10 CFR 430.2 encompasses only electric 
instantaneous water heaters that are residential (i.e., with an input 
capacity of 12 kW or less). However, as discussed in section III.A.1, 
commercial (i.e., with an input capacity greater than 12 kW) electric 
instantaneous water heaters with input ratings up to 58.6 kW are 
considered ``residential-duty commercial water heaters,'' and because 
water heaters both above and below 12 kW have residential applications, 
both types would be covered by the uniform efficiency descriptor.
    In response to the November 2013 NOPR, Seisco and Thomas Harman 
commented that 12 kW is not an appropriate cutoff for electric 
instantaneous water heaters because there are many electric 
instantaneous water heaters designed for and used in residences that 
have input ratings above 12 kW. (Harman, No. 53 at p. 1; Seisco, No. 57 
at pp. 10-11) In response, DOE notes that the 12 kW limit is defined by 
EPCA and it is not at DOE's discretion to change. However, the 12 kW 
criteria will apply only insofar as determining the applicable minimum 
energy conservation standard. As such, it remains the point above which 
electric instantaneous models would be classified as ``commercial'' 
equipment for the basis of determining the applicable energy 
conservation standards. Limits on the application of the uniform 
efficiency descriptor pursuant to the new test procedure based on input 
and volume capacities are set forth in Table III.2, above.
    This final rule also provides for a maximum flow rate test for 
electric instantaneous water heaters and a test to determine the energy 
efficiency expressed in terms of uniform energy factor for these 
products. (As discussed in section III.B, the energy efficiency metric 
for water heaters will be changed from ``energy factor'' to ``uniform 
energy factor.'') These tests are identical to those provided for gas-
fired instantaneous water heaters.

B. Uniform Efficiency Descriptor Nomenclature

    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 November 2013 NOPR, DOE proposed to use a revised version of 
the energy factor as the uniform efficiency descriptor. 78 FR 66202, 
66210 (Nov. 4, 2013). DOE received no comments opposing the continued 
use of the energy factor metric in response to the November 2013 NOPR. 
However, DOE received four comments (A.O. Smith, Bradford White, EEI, 
Joint Comment) suggesting that the ``energy factor'' nomenclature be 
adjusted to distinguish the old energy factor from the new. 
Additionally, the four commenters suggest that the new ``energy 
factor'' nomenclature be differentiated by class (i.e., subscripts with 
the draw classification). (A.O. Smith No. 62 at p. 3; Bradford White 
No. 61 at p. 6; EEI No. 63 at p. 4; Joint Comment No. 77 at p. 2) NEEA 
and NPCC commented that the ``energy factor'' nomenclature as it 
currently stands is appropriate and that changes to the test procedure 
are not significant enough to warrant a new descriptor. (NEEA and NPCC 
No. 64 at p. 1) NEEA and NPCC and the Joint Comment stated that the new 
``energy factor'' nomenclature should not be distinguished by fuel type 
or technology

[[Page 40550]]

group. (NEEA and NPCC No. 64 at p. 16; Joint Comment No. 77 at p. 2)
    DOE agrees with commenters that confusion could occur if the name 
of the metric remains unchanged between the current and amended test 
procedures. Because the existing and new ratings are determined under 
different test conditions, which can result in a different rating, DOE 
believes it is necessary to adopt a new name to distinguish between the 
efficiency result under the existing test procedure and the result 
under the amended test procedure. As a result, DOE adopts a ``uniform 
energy factor,'' to be denoted as ``UEF'' in the test procedure, as 
distinguished from the ``Ef'' rating determined under the 
current test procedure.

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.
    DOE proposed to modify the draw pattern that is used in the 
existing test procedure in the November 2013 NOPR. 78 FR 66202, 66210-
17 (Nov. 4, 2013). Under DOE's proposal, the single draw pattern that 
is currently applied during the 24-hour simulated use test would be 
replaced with one of four patterns that is more representative of the 
demand put on a water heater of different delivery capacity. These four 
draw patterns were termed ``point-of-use,'' ``low usage,'' ``medium 
usage,'' and ``high usage.'' The selection of the draw pattern to be 
used in the simulated-use test would be based upon the results of the 
first-hour rating test or the maximum GPM (gallons per minute) rating 
test.
    DOE received seven comments in general support of the move to four 
different draw patterns. (HTP No. 59 at p. 2; A.O. Smith No. 62 at p. 
2; EEI No. 63 at p. 4; NEEA and NPCC No. 64 at p. 3; AHRI No. 75 at p. 
3; Giant No. 76 at p. 3; Joint Comment No. 77 at p. 6) HTP recommended 
that DOE consider altering the total water drawn in the medium-usage 
pattern to 64.8 gallons to assist in correlating between current 
metrics and the proposed metrics. NEEA and NPCC indicated a slight 
preference for draw patterns proposed as part of the deliberations for 
ASHRAE 118.2, ``Method of Testing for Rating Residential Water 
Heaters,'' because those draws are more consistent with the daily hot 
water use found in their field data. AHRI indicated that the proposed 
draw patterns were appropriate but that it preferred the draw patterns 
submitted in its comment to the January 2013 RFI. (AHRI No. 46 at p. 5)
    DOE received one comment that supported the move to multiple draw 
patterns but that recommended five draw patterns instead of four and 
provided alternative bases for developing the patterns. (AET No. 58 at 
p. 3) AET commented that the proposed draw patterns could result in 
water being delivered during the simulated-use test that may be 
considered to be too cold for typical uses and recommended that a fifth 
category termed ``Sink'' be created that would apply to the smallest 
water heaters. AET discussed how the amount of water that can be 
withdrawn in a continuous draw can be estimated from the first-hour 
rating and stated that the maximum draw volumes imposed in the proposed 
draw patterns may yield an ``invalid test.'' Particular emphasis was 
placed on the point-of-use category, in which a 2-gallon water heater 
would be expected to deliver a 2-gallon draw. Another concern expressed 
by AET is that water heaters with the same storage volume but with 
slightly different input rates would be tested according to different 
draw patterns. AET suggested that selection of the draw pattern used 
for the simulated-use test should be based on two factors: the measured 
storage volume and the first-hour rating. AET recommended the largest 
draw volume that should be implemented in each draw pattern to meet the 
capabilities of the water heaters in that category. AET estimated that 
the first draw delivery capability of a storage water heater is 
0.95*0.85*(Rated Storage Volume), where 0.95 represents the currently 
allowed tolerance on storage volume and 0.85 accounts for mixing of hot 
and cold water during draws. Id.
    DOE received three comments from AET, SMT, and Bradford White 
related to the details in the proposed test procedure of determining 
the standby loss coefficient, ``UA,'' which is used to adjust the daily 
energy consumption to account for deviations from nominal conditions. 
AET expressed concern that, with water heaters having very slow 
recoveries, the test could result in a water heater with drastically 
different stored water temperature at the start of the test than at the 
end, thereby necessitating a major correction to the energy consumed. 
AET recommended extending the test beyond 24 hours for such water 
heaters, ending the test only after a recovery occurs. Energy 
consumption during the test would be modified to normalize to a 24-hour 
time period by removing the estimated standby loss during the time 
exceeding 24 hours. AET commented that it is much more accurate to 
normalize to a common time period than it is to end the test prior to a 
recovery occurring. AET stated that this approach would ensure that a 
recovery occurs during the period of the test when the UA value is 
determined and that it would result in an average tank temperature that 
changes less from the start of the test to the end of the test. (AET 
No. 58 at p. 1). SMT expressed concern that large-capacity models may 
not initiate recovery during the first draw cluster of tests or may 
initiate a recovery during a standby portion of the test. In these 
cases, SMT commented that determination of the UA may not be possible. 
SMT suggested that the test should start with a fully-charged water 
heater and that the first draw cluster should start eight hours after 
this point. According to SMT, the UA value would be determined during 
this eight-hour period. (SMT No. 66 at p. 2). Bradford White commented 
that the new test procedure can take standby loss readings when the 
water heater is recovering and/or when water is being drawn, which 
would lead to inaccurate measures of standby loss. (Bradford White No. 
61 at p. 8).
    After consideration of these comments, DOE has decided to adopt the 
modifications to the draw patterns as originally proposed in the 
November 2013 NOPR. DOE has reviewed the total amount of water drawn 
per day in each draw pattern and has observed that those values match 
well with field data collated by the Lawrence Berkeley National 
Laboratory.\10\ DOE acknowledges that a medium-use draw pattern having 
the same daily draw volume as that prescribed in the current test 
procedure would remove some uncertainty in converting from the existing 
efficiency metric to the new uniform metric since the total daily draw 
volume would not impact the rating. However, DOE has decided to 
maintain a lower daily draw volume in the new draw schedule to better 
match

[[Page 40551]]

field data available for a medium-usage situation.
---------------------------------------------------------------------------

    \10\ 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 http://www.escholarship.org/uc/item/2k24v1kj) (last accessed June 17, 2014).
---------------------------------------------------------------------------

    DOE considered adding a fifth draw pattern as recommended by AET, 
but a review of data from testing of low-volume water heaters indicate 
that the efficiency can be accurately determined using the four 
proposed draw patterns. While delivery temperatures did drop below 
120[emsp14][deg]F during some draws of these tests, DOE has concluded 
that the efficiency is still accurately determined using this test 
procedure and that the added complexity of an additional draw pattern 
is not warranted.
    DOE will continue to use the first-hour rating to assign a draw 
pattern for use during the simulated-use test. DOE examined using a 
combination of first-hour rating and storage volume to categorize the 
water heater for assigning a draw pattern, as suggested by AET, but is 
concerned that some water heaters may not fit into any category because 
their storage volumes would correspond to one draw pattern while their 
first-hour ratings would correspond to a different one. Additionally, 
as noted above, AET estimates that the first draw delivery capability 
of a storage water heater is 0.95*0.85*(Rated Storage Volume), which 
accounts for the tolerance currently afforded manufacturers on storage 
volume and the effect of mixing of hot and cold water within the 
storage water heater during draws. DOE agrees that this method for 
estimating first draw delivery capacity is appropriate for conventional 
electric storage water heaters. However, the Department is concerned 
that the effect of mixing hot and cold water within the unit during 
draws is not well understood for the emerging water-heating 
technologies that are noted by the commenter. Therefore, basing the 
categorization of water heaters into usage bins (i.e., very small, low, 
medium, and high) to determine the appropriate draw pattern based on 
this uncertain number is likely to lead to miscategorization for some 
water heaters. In the end, DOE has decided that the first-hour rating 
is the best metric available for determining water heater size 
classification for purposes of efficiency testing.
    DOE is adopting the draw volumes proposed in the November 2013 
NOPR. Test results \11\ indicate that the draw volumes incorporated 
into the proposed patterns, while resulting in delivery temperatures 
that may not match the nominal outlet temperatures, provide a 
sufficiently accurate estimate of the energy efficiency and that these 
draw patterns will result in an accurate estimate of the efficiency of 
water heaters within each size classification. The flow rates and 
volumes specified in the November 2013 NOPR represent the best 
alternative for characterizing water heaters at both the lower and 
upper limits of a size category.
---------------------------------------------------------------------------

    \11\ Test results from DOE testing for the NOPR are summarized 
in the November 2013 Water Heater Test Procedure Rulemaking 
Development Testing Preliminary Report, available in the rulemaking 
docket at: http://www.regulations.gov/#!documentDetail;D=EERE-2011-
BT-TP-0042-0052.
---------------------------------------------------------------------------

    In response to the comment from Bradford White stating concern that 
the standby loss coefficient (UA) can be determined while a recovery is 
occurring, DOE notes that there is a possibility of a recovery taking 
place during the portion of the test when data are collected to 
determine UA, just as there is the possibility in the current test 
method. The determination of UA, however, may require a reheat to 
maintain the stored water temperature to obtain a valid estimate of UA. 
As for the standby time period during which energy loss to the ambient 
is corrected, DOE notes that time when draws are taking place are 
omitted from the calculation. See section 6.3.5 of appendix E as 
adopted in this final rule. Therefore, DOE is making no changes in 
response to the comment.
    DOE considered amending the timing of the simulated-use test, as 
suggested by some commenters, to improve the determination of UA. DOE 
examined data from a range of simulated-use tests and decided that the 
test procedure requires modification to improve the determination of UA 
for some special cases.
    The first modification responds to concerns expressed about the 
determination of UA for water heaters with low recovery rates. DOE 
observed that the first recovery may not begin until several hours into 
the designated standby period and could extend into the second draw 
cluster. DOE examined data from tests on such water heaters and 
modified the test procedure provisions for determining UA in the event 
that a recovery does not begin during the first draw cluster.
    As proposed in the November 2013 NOPR, the standby period for 
determination of UA was intended to occupy the majority of the period 
between the end of the first draw cluster and the start of the second 
draw cluster. 78 FR 66202, 66217, 66236 (Nov. 4, 2013). However, 
because the standby period is supposed to start at the end of the first 
recovery under the proposed procedure, the standby period may not start 
until well into the 24-hour test for water heaters with a very slow 
recovery rate. For one tested water heater, DOE observed that the first 
recovery did not begin until several hours past the end of the first 
draw cluster and ended after subsequent draws occurred during the test. 
Under the proposed test procedure, the standby period started at the 
end of this first recovery period and continued until the next draw 
started. This procedure could result in a very short time period for 
determination of UA, which might lead to erroneous results.
    To address this issue, DOE amends the proposed test procedure by 
starting the standby period five minutes following the last draw of the 
first draw cluster if a recovery is not occurring, as opposed to 
waiting until after the first recovery period ends. The end point of 
the standby period will remain as proposed in the November 2013 NOPR. 
This change ensures an accurate determination of UA for all units, 
including those with low recovery rates and those that delay onset of 
heating until after the first cluster of draws.
    The second clarification addresses water heaters that undergo a 
recovery that begins at the end of the first draw cluster and continues 
over the entire standby period between the first and second draw 
clusters. In these instances, the standby period continues past the end 
of the 24-hour test. To address this issue, DOE amends the test 
procedure to initiate the standby period at the end of the first 
recovery following the final draw and to continue measurements for 
eight hours from that point.
    DOE concludes that the approaches implemented in the final rule 
will determine a standby loss coefficient that accurately adjusts the 
daily energy consumption when the ambient temperature deviates from the 
nominal value during testing. The Department is adopting this approach, 
as opposed to the one presented by AET, in order to maintain a test 
duration of 24 hours for nearly all water heaters while providing 
accurate representation of the water heater's energy efficiency.
    DOE received one comment requesting a change in the name of the 
``point-of-use'' draw pattern, stating that the term ``point-of-use'' 
describes the installed location of a water heater as opposed to the 
delivery capacity, which is the characteristic described by the other 
three category names (i.e., ``low,'' ``medium,'' and ``high''). (AIM 
No. 71 at p. 1) AIM suggested a name of ``very small'' for this 
category. DOE agrees in principle with this comment and has decided to 
change the name of the ``point-of-use'' category to ``very-small-
usage.''
    Bradford White commented that the tolerances of +/-0.25 gallons for 
the volume removed in each draw in the proposed test procedure could 
lead to

[[Page 40552]]

large discrepancies in the overall volume removed, which could in turn 
necessitate a test laboratory to skip a final draw to achieve the 
overall tolerance of +/-1 gallon for the daily water delivery. 
(Bradford White No. 61 at pp. 8-9) DOE agrees with this observation and 
is tightening the tolerances on some draws in the final rule. For draws 
taken at a nominal flow rate of 1.7 GPM or less, DOE is requiring that 
those draws have a tolerance of +/-0.1 gallons. With the data 
acquisition rate during draws set to 3 seconds, DOE believes that this 
level of tolerance is achievable. At the nominal flow rate of 3 GPM, 
however, the frequency of data collection may not allow for such tight 
control of draw volumes during each draw, so DOE is maintaining the 
tolerance of +/-0.25 GPM for those draws. DOE is already increasing the 
frequency of data collection and does not believe it is necessary to 
increase it further to allow for a stricter tolerance on 3 GPM draws. 
DOE notes that only the high-usage pattern contains draws with a flow 
rate of 3 GPM, and only 3 of the 14 draws are at that flow rate. As a 
result, DOE expects that the overall tolerance of +/-1 gallon for the 
daily water delivery can be achieved because the tighter tolerance 
applies to the remaining 11 draws.
    DOE acknowledges that, given the tolerances on individual draws, a 
situation may arise whereby the volume of the final draw would need to 
be adjusted downward so much that a draw volume of zero may be required 
to meet the overall tolerance on the daily draw volume. DOE concludes 
that this scenario would result in an invalid test and has inserted a 
statement in the test procedure indicating that ``if this adjustment to 
the volume drawn in the last draw results in no draw taking place, the 
test is considered invalid.'' Table III.3 through Table III.6 show the 
draw patterns that DOE is adopting.

                                   Table III.3--Very-Small-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                       Time during test    Volume  [gallons    Flow rate ** [GPM
                      Draw No.                              [hh:mm]              (L)]              (L/min)]
----------------------------------------------------------------------------------------------------------------
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 maximum GPM rating less than 1 GPM (3.8 L/min), then all draws shall be
  implemented at a flow rate equal to the rated maximum GPM.

                                       Table III.4--Low-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                       Time during test    Volume  [gallons   Flow rate  [GPM (L/
                      Draw No.                              [hh:mm]            (liters)]             min)]
----------------------------------------------------------------------------------------------------------------
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.5--Medium-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                       Time during test    Volume  [gallons   Flow rate  [GPM (L/
                      Draw No.                              [hh:mm]            (liters)]             min)]
----------------------------------------------------------------------------------------------------------------
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)

[[Page 40553]]

 
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.

                                      Table III.6--High-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                       Time during test    Volume  [gallons   Flow rate  [GPM (L/
                      Draw No.                              [hh:mm]            (liters)]             min)]
----------------------------------------------------------------------------------------------------------------
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.

D. Instrumentation

    In the November 2013 NOPR, DOE proposed to maintain the 
instrumentation installation requirements and piping configuration as 
currently specified in the residential water heater test procedure. 78 
FR 66202, 66217 (Nov. 4, 2013). For storage water heaters having a 
rated volume below 20 gallons, which are not covered in the existing 
DOE test method, DOE proposed that the average tank temperature be 
determined based on three temperature sensors located at the vertical 
midpoints of three sections of equal volume within the storage tank, as 
opposed to the currently required six sensors for storage water heaters 
having a rated volume above 20 gallons. Id. No comments were received 
opposing this approach, but AET requested that guidance should be 
provided regarding the unspecified horizontal lengths of pipe in the 
figures. (AET No. 58 at p. 20) For the final rule, DOE has modified 
Figures 1 through 4 of the test procedure to include those dimensions.
    DOE proposed in the November 2013 NOPR to tighten the allowed 
accuracy on electric power and energy measuring equipment from the 
current value of 1 percent to 0.5 percent. 78 
FR 66202, 66217 (Nov. 4, 2013). A study has shown the significant 
effect of the accuracy of the electric power measurements on the 
uncertainty in the overall energy factor.\12\ A similar 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 is readily available. DOE also proposed in the November 
2013 NOPR 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 must be used to make the measurement. Id. 
Lastly, DOE proposed that, for relative humidity measurements, a sensor 
that is accurate within 1.5 percent of the reading be used 
to make the measurement. Id. at 66220. No comments were received 
opposing these proposals, so DOE has incorporated these proposals into 
the final rule.
---------------------------------------------------------------------------

    \12\ 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 proposed in the November 2013 NOPR to modify the data 
acquisition rate of the inlet and outlet water temperature during 
draws. Id. at 66217. Currently, for all water heaters except variable 
firing rate instantaneous water heaters, measurements of the inlet and 
outlet water temperature are taken at 5-second intervals starting 15 
seconds after the draw commences. For instantaneous water heaters with 
a variable firing rate, inlet and outlet water temperature measurements 
are taken at 5-second intervals starting 5 seconds after the draw 
commences. The 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 proposed 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 will 
better capture the energy impact of water heater startup and cycling. 
Id. at 66217. No comments were received opposing these measures, so DOE 
has incorporated these proposals into the final rule.

E. Test Conditions

1. Outlet Water Temperature
    The current residential water heater test procedure calls for the 
temperature of the tank to be set so that the average hot water 
temperature within the storage tank is at 135[emsp14][deg]F  5[emsp14][deg]F (57.2 [deg]C  2.8 [deg]C). 10 CFR 
part 430, subpart B, appendix E, section 2.4. The set point

[[Page 40554]]

impacts the performance of various types of water heaters differently, 
so DOE reexamined in the proposed test procedure the set point 
specification and how it is determined. In the November 2013 NOPR, DOE 
proposed to use a measurement of the temperature of the delivered 
water, rather than mean tank temperature, for setting the temperature 
for storage-type water heaters, and also proposed that the set point 
temperature of all residential water heaters be reduced to 
125[emsp14][deg]F +/- 5[emsp14][deg]F (51.7 [deg]C +/- 2.8 [deg]C). 78 
FR 66202, 66219-20 (Nov. 4, 2013). This value was primarily selected 
based on data available in DOE's analysis for the April 2010 energy 
conservation standards final rule, which found that the average set 
point temperature for residential water heaters in the field is 
124.2[emsp14][deg]F (51.2 [deg]C). Additionally, the recent compilation 
of field data across the United States and southern Ontario by LBNL 
(referenced above) found a median daily outlet water temperature of 
122.7[emsp14][deg]F (50.4 [deg]C), which supports specifying a test set 
point temperature of 125[emsp14][deg]F. DOE proposed that 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 also tentatively concluded that 
a set point of 125[emsp14][deg]F in the test method would not result in 
safety concerns related to the growth of Legionella. Further, DOE noted 
that water heaters are commonly set to temperatures in the range of 
120[emsp14][deg]F to 125[emsp14][deg]F even though the current set 
point in the test method is 135[emsp14][deg]F. 78 FR 66202, 66219 (Nov. 
4, 2013).
    DOE received five comments (AET, EEI, HTP, NEEA and NPCC, Joint 
Comment) in response to DOE's outlet water temperature proposals in the 
November 2013 NOPR supporting the switch to a set point temperature of 
125[emsp14][deg]F for the first-hour rating and maximum flow rate tests 
and the 24-hour simulated-use test. (AET, No. 58 at p. 5; EEI, No. 63 
at p. 5; HTP, No. 59 at pp. 1-3; NEEA and NPCC, No. 64 at p. 9; Joint 
Comment, No. 77 at pp. 6-7) Advocates for the 125[emsp14][deg]F outlet 
water temperature argue that it is the most representative of actual 
use in the field and, thus, should be used to determine performance 
under representative conditions. Additionally, AET and HTP suggested 
that specifying an outlet water temperature, as opposed to a stored 
water temperature, is more appropriate for evaluating water heaters 
using certain controls that purposely keep the stored water temperature 
at a low value. (AET No. 58 at p. 1; HTP, No. 59 at p. 3) DOE received 
five comments (AIM, AHRI, A.O. Smith, GE, and Giant) in favor of 
keeping the set point temperature at 135[emsp14][deg]F for the first-
hour rating test or increasing it for both the first-hour rating/
maximum flow rate test and the 24-hour simulated-use test. (AIM, No. 72 
at p. 3; AHRI, No. 75 at pp. 3-4; A.O. Smith, No. 62 at p. 2; GE, No. 
78 at p. 1; Giant, No. 76 at pp. 2-3) Four of the commenters who 
opposed the decrease in set point (AHRI, A.O. Smith, GE, Giant) argue 
that the burden of reestablishing the draw pattern bin categories using 
first-hour rating and maximum GPM values under the lower set point is 
too great because the change in first-hour ratings will add additional 
uncertainty to the establishment of the bins. AIM argued that the set 
point temperature should be increased because when the temperature is 
decreased in the field, the water heater will see a boost in energy 
efficiency. Rheem acknowledged that many water heaters are operated at 
lower temperatures than the set point specified in the current DOE test 
procedure and suggested that the 24-hour simulated-use test and 
associated draws would be more representative at the 125[emsp14][deg]F 
set point temperature. However, based on test data, Rheem argued that 
the changes to the first-hour rating values from the change in set 
point are too unpredictable to serve as a basis for determining the 
draw pattern bin categories and suggested that the first-hour rating 
test should continue to be performed at 135[emsp14][deg]F, as is 
current practice. (Rheem, No. 69 at pp. 3, 5)
    DOE has carefully considered these comments and concludes that a 
delivered water temperature of 125[emsp14][deg]F will be applied to 
first-hour rating tests for storage water heaters, maximum flow rate 
tests for flow-activated water heaters, and energy factor tests for all 
water heaters. DOE is required to establish test procedures that are 
representative of how a covered product would be used in the field, and 
based on the data discussed previously, DOE concludes that 
125[emsp14][deg]F is the most representative temperature for the United 
States market. DOE has determined that the test should be conducted at 
a typical operating temperature and should not penalize those units 
optimized for such typical conditions. Moreover, DOE has determined 
that conducting the simulated-use test at a different temperature from 
the delivery capacity tests would add an undue burden on manufacturers 
and would result in ratings that would not be representative of typical 
usage in the field. While maintaining the test temperature at the value 
currently used in the test procedure could eliminate one source of 
uncertainty in converting existing energy factors to new uniform energy 
factors, DOE has determined that this conversion is feasible and that 
the benefits of testing at a representative temperature outweigh the 
short-term challenges in converting existing ratings.
    In response to the concerns expressed by AHRI, A.O. Smith, GE, and 
Giant regarding uncertainties in converting first-hour ratings values 
obtained at 135[emsp14][deg]F to comparable values at 
125[emsp14][deg]F, DOE revisited the values that were used to place 
water heaters into bins for uniform energy factor testing. In the 
November 2013 NOPR, DOE based these breakpoint values on information 
present in the current plumbing code that indicate appropriate water 
heaters for various home configurations based on their first hour 
rating values obtained under the existing test procedure. 78 FR 66202, 
66214 (Nov. 4, 2013). Preliminary testing by DOE indicated that the 
first-hour ratings obtained under the new procedure were comparable to 
those obtained under the existing test procedure, so DOE proposed to 
maintain the breakpoints between bins despite the change in the 
conditions for the first-hour rating test.
    DOE requested data to demonstrate the effect of modifying the 
first-hour rating test conditions and received data from Rheem and 
Bradford White. (Rheem No. 69 at p. 3; Bradford White No. 61 at p. 8) 
Rheem presented actual first-hour rating values under both the current 
test and the proposed test, whereas Bradford White simply provided the 
percentage change in the first-hour rating between the two test 
procedures. Both data sets suggest an overall downward trend of first-
hour rating under the proposed test procedure but that there is 
variability in the results. Based on these data and additional data 
collected by DOE, the Department concludes that numerous 
characteristics of a water heater affect the change in its first-hour 
rating obtained at 135[emsp14][deg]F, as compared to that obtained at 
125[emsp14][deg]F. The uncertainty in how the ratings change, however, 
does not justify abandoning the 125[emsp14][deg]F test temperature. 
Since DOE has determined that the most representative delivery 
temperature is 125[emsp14][deg]F and no comments were received that 
refuted the method applied to obtain the first-hour rating at that 
temperature, DOE concludes that the first-hour rating test, as 
proposed, provides an appropriate measure of the delivery capacity of a 
water heater as would be observed in the field.

[[Page 40555]]

    DOE maintains that the breakpoint values used to place water 
heaters into bins for uniform energy factor testing presented in the 
NOPR are appropriate for tests conducted at 135[emsp14][deg]F, but 
acknowledges that some adjustments may be needed for tests conducted at 
125[emsp14][deg]F since first-hour rating values may change at this 
temperature. To better account for the change in the first-hour rating 
procedure, DOE used the expanded set of available experimental data to 
reassess the proposed breakpoint values of first-hour ratings for 
placing water heaters into sizing bins for the simulated-use test. DOE 
examined different regressions using the data submitted by Rheem and 
those collected by the Department and found that the ratings at 
125[emsp14][deg]F and those at 135[emsp14][deg]F could be modeled as 
functions of storage volume and the product of input rate and recovery 
efficiency. The recovery efficiency for data presented by Rheem was 
estimated based on the description of the water heater being tested. 
These regressions were then used to determine what breakpoint values 
would result in nearly the same classification for a particular water 
heater tested at 125[emsp14][deg]F as it would have when tested at 
135[emsp14][deg]F, based on its storage volume, recovery efficiency, 
and input rate. Based on this analysis, DOE decreased the breakpoint 
values for each size classification for testing at 125[emsp14][deg]F 
under the new test procedure, as compared to the breakpoint values 
proposed in the NOPR.\13\ The new limits of first-hour ratings (FHR) 
for each category are as follows:
---------------------------------------------------------------------------

    \13\ In the November 2013 NOPR, DOE proposed the following 
breakpoints for each size classification for testing at 
125[emsp14][deg]F. Point-of-use (since renamed ``very small''): = 80 gallons. 78 FR 66202, 66235 (Nov. 4, 2013).

Very Small: FHR = 75 gallons

    For the first-hour rating test, DOE proposed in the November 2013 
NOPR that draws would terminate when the outlet temperature drops 
15[emsp14][deg]F (8.3 [deg]C) from its maximum outlet temperature 
during the draw, as opposed to the drop of 25[emsp14] [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[emsp14][deg]F (43.3 [deg]C). AET and AIM supported this proposal. 
(AET, No. 58 at p. 6; AIM, No. 72 at p. 1) AET suggested that water 
delivered at a temperature lower than the minimum useful temperature of 
110[emsp14][deg]F should not be counted in the first-hour rating test. 
AIM suggested that useful hot water delivered be measured separately 
from total water delivered. AET and AIM also suggested that water 
delivered below 110[emsp14][deg]F should not be counted as useful 
delivered hot water in the 24-hour simulated use test. (AET No. 58 at 
p. 7; AIM No. 72 at p.1)
    DOE concludes that the lower temperature limit of useful hot water 
at 110[emsp14][deg]F is appropriate for the first-hour rating test and 
establishes that draws during the test will terminate when the delivery 
temperature drops to 15[emsp14][deg]F below the outlet water 
temperature (which is nominally 125[emsp14][deg]F), resulting in a draw 
termination temperature of approximately 110[emsp14][deg]F for draws 
during the first-hour test. For the simulated-use test, however, DOE 
does not restrict outlet water temperature to at or above 
110[emsp14][deg]F. While it strongly considered the comments made by 
AET and AIM in this regard, in DOE's view, the simulated-use test, 
which provides a measure of energy efficiency rather than delivery 
capability, is best conducted without regard to water outlet 
temperature. A standard cutoff temperature of 110[emsp14][deg]F is 
necessary for the first-hour rating test in order to determine the 
appropriate draw pattern, but no minimum temperature is necessary to 
estimate energy efficiency. Although DOE has selected its draw patterns 
to ensure that a water heater can deliver hot water during all draws, 
DOE recognizes that there may be cases where water heaters on the lower 
end of the capacity limit in each bin deliver water at a lower 
temperature than a consumer might desire. In these cases, DOE believes 
that accounting for water delivered at temperatures below 
110[emsp14][deg]F would be representative of water heater energy 
performance in the field. DOE uses correction factors in the test 
procedure's calculation routines to adjust the daily energy consumption 
to estimate energy consumption at a nominal outlet temperature of 
125[emsp14][deg]F since daily energy consumption will differ based on 
the outlet temperature of the water provided.
    As noted above, in addition to proposing to change the temperature 
setting at which the test occurs, DOE also proposed in the November 
2013 NOPR to change the methodology for setting the temperature of 
storage-type units to rely on outlet water temperature rather than mean 
tank temperature. For water heaters with a single thermostat, DOE 
proposed to specify a set point based on the outlet water temperature 
during a draw. For water heaters with multiple thermostats, DOE 
proposed to maintain the procedure currently prescribed in the 
residential water heater test method, which specifies the set point 
based on water temperature inside the tank. 78 FR 66202, 66219-20 (Nov. 
4, 2013).
    In response, DOE received three comments that supported the 
proposed approach for specifying the set point based on the temperature 
of delivered water for water heaters with a single thermostat in the 
tank. However these commenters argued that the same approach should be 
applied for water heaters with multiple thermostats. (AET, HTP, A.O. 
Smith) Specifically, AET and HTP cautioned that the terminology used in 
the NOPR that provides a procedure for water heaters with multiple 
``thermostats'' could be problematic because some water heaters utilize 
multiple temperature sensors (i.e., thermostats) that are not available 
to the user for modifying the delivery temperature but that are instead 
installed to relay data to a single controller that determines whether 
or not to activate heating. (AET No. 58 at p. 2; HTP No. 59 at p. 3). 
AET and HTP both submitted recommendations for setting the temperature 
controllers on water heaters with multiple control points. (AET No. 58 
at p. 14; HTP No. 59 at p. 4) AET urged DOE to utilize the first-hour 
rating test to verify that the temperature controllers are set to their 
proper value. According to AET, the temperature controls on a unit with 
multiple controllers would be determined to be within their proper 
settings if all of the following conditions are met: (1) At least 50 
percent of the water drawn during the first draw of the first-hour 
rating test was delivered at a temperature between 120[emsp14][deg]F 
and 130[emsp14][deg]F; (2) no water is delivered with a temperature 
above 130[emsp14][deg]F during the first-hour rating test; and (3) the 
initial delivery temperature of second and subsequent draws of the 
first-hour rating test is between 120[emsp14][deg]F and 
130[emsp14][deg]F. AET asserts that, if these three conditions are met, 
then the water heater has the correct set-point and the results from 
the temperature set-point test can be used to determine the first-hour 
rating. On this topic, HTP suggested a method that progressively 
disables the thermostats, and uses draws of one-fourth of the total 
volume, taken after full recovery of each of the heat inputs being 
controlled by the active thermostats, to determine if the delivery 
temperature falls within the requisite 125[emsp14][deg]F +/- 
5[emsp14][deg]F range. If the water heater does not achieve the 
required delivery temperature within five iterations, the test 
laboratory would resort to the technique proposed in the NOPR.

[[Page 40556]]

    DOE also received several comments opposed to the proposed 
approach. DOE received one comment (Rheem) that opposed the approach of 
specifying a set point for a water heater with a single thermostat in 
the tank based on outlet temperature, arguing that this method 
mischaracterizes the stored energy inside the tank. (Rheem No. 69 at p. 
5) DOE does not agree with this claim since the stored energy inside 
the tank is measured in the proposed procedure in the same manner as is 
done in the current procedure and because setting the outlet 
temperature or stored water temperature is independent of the 
determination of stored energy. AHRI and Giant stated that they do not 
agree with the proposed method because ``the method used when the model 
has more than one thermostat should follow the basic principles of the 
procedure for setting thermostats in the current test method.'' (AHRI 
No. 75 at p.4; Giant No. 76 at p.3) On the point raised by AHRI and 
Giant, DOE notes that the method for models with more than one 
thermostat proposed in the November 2013 NOPR already matches the 
approach specified in the current test method.
    After careful consideration of the comments, DOE has decided to 
adopt several changes to the method to determine set point temperature 
for storage-type water heaters. First, in response to comments 
regarding the use of the terminology ``thermostat,'' DOE has changed 
the description from thermostat to ``temperature controller'' and has 
added a definition of temperature controller as ``a device that is 
available to the user to adjust the temperature of the water inside a 
storage-type water heater or the outlet water temperature.'' This 
change in terminology should eliminate any confusion on the part of the 
user of the test procedure between the user-accessible temperature 
controls and temperature sensors that are used in the water heater but 
may not be directly accessible to the user for making temperature 
adjustments.
    Second, DOE has decided to maintain its stated approach in the NOPR 
for setting the temperature for water heaters with a single temperature 
controller. In the final rule, DOE specifies that the set point be 
based on outlet water temperature. DOE determined that some water 
heaters would be disadvantaged by requiring an average tank temperature 
of 125[emsp14][deg]F--due to stratification, a tank with an average 
temperature of 125[emsp14][deg]F would deliver water at a temperature 
higher than 125[emsp14][deg]F. Such a setting could have an 
unrepresentative detrimental effect on efficiency compared to its 
intended operation in the field if the design of the water heating 
system relies on the average temperature of the stored water being at a 
lower temperature than the temperature of the water delivered to the 
user.
    Third, DOE incorporates the method suggested by AET to specify the 
set point of a water heater with multiple temperature controllers 
because it can be performed in conjunction with the first-hour rating 
test. However, DOE has modified one aspect of AET's suggested method by 
allowing water delivered during a final draw of the first-hour rating 
test that begins at the end of the test to fall below 120[emsp14][deg]F 
because the water heater may not have recovered fully when the final 
draw is initiated. This approach ensures proper temperature settings 
and will be less burdensome than the alternate technique proposed by 
HTP because it can be performed in conjunction with the first-hour 
rating test.
    Finally, DOE eliminates normalization of the daily water-heating 
energy consumption to a nominal stored water temperature, as provided 
in the current test procedure. DOE received two comments recommending 
that, because of the proposed technique to base the temperature setting 
of the water heater on the outlet water temperature, the test procedure 
should not normalize the energy consumption of any storage water heater 
to a nominal stored water temperature of 125[emsp14][deg]F. (AET No. 58 
at p. 14; SMT No. 66 at p. 3) AET indicated that normalizing to a 
nominal stored water temperature penalizes advanced control 
technologies that manipulate storage temperature to reduce heat losses 
and improve performance. SMT commented that some water heater models 
are designed to operate with stratified tanks and that many utilize 
control algorithms that purposely manage the water temperature at the 
middle and lower levels differently from the top of the tank. DOE 
agrees with these comments. DOE is concerned that the temperature 
setting on the water heater could be lowered during the simulated-use 
test to an unrealistic value that would result in delivered water that 
is below a usable level. To avoid this situation, the final rule 
provides that the temperature control settings shall not be changed for 
the duration of the delivery capacity test and the simulated-use test 
once they are determined pursuant to the test procedure. Additionally, 
the final rule includes language that will allow a test laboratory to 
verify that the temperature settings are appropriate throughout the 
test by conducting a second 24-hour simulated-use test immediately 
after the test used to determine the uniform energy factor and with an 
identical draw pattern. If the average delivered temperature during 
this second 24-hour test is within the temperature bounds specified by 
the test procedure, then the temperature control scheme meets the 
requirements of the test procedure in providing the required outlet 
water temperature.
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[emsp14][deg]F  2.5[emsp14][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[emsp14][deg]F  1[emsp14][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 November 2013 NOPR, DOE proposed not to change the current 
ambient dry bulb temperature of between 65[emsp14][deg]F and 
70[emsp14][deg]F when testing water heaters other than heat pump water 
heaters and at 67.5[emsp14][deg]F  1[emsp14][deg]F when 
testing heat pump water heaters. DOE also proposed to include the 
current relative humidity of 50 percent for heat pump water heaters, 
but to relax the tolerance to  2 percent relative humidity. 
DOE believes these conditions are 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 proposed 
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 (78 FR 66202, 66220 
(Nov. 4, 2013)), and the tolerance cannot exceed the accuracy of the 
measuring equipment. It should be noted that the relative humidity can 
be obtained from measurements of dry bulb and wet bulb

[[Page 40557]]

temperatures and the determination of relative humidity through these 
temperature measurements would result in a measure of relative humidity 
with much lower uncertainty because dry bulb and wet bulb temperatures 
can be measured with high accuracy. However, most laboratories use 
relative humidity sensors that provide an accurate measurement of 
relative humidity through a less burdensome method. DOE received one 
comment from SMT suggesting that imposing the same dry bulb air 
temperature for all water heaters that is imposed for heat pump water 
heaters could eliminate the necessity of correcting the energy 
consumption for differences between the measured air temperature and 
the nominal temperature. (SMT No. 66 at p.3) DOE is not adopting this 
recommendation because it may necessitate significant changes in 
laboratory environmental conditioning equipment that would be very 
costly to manufacturers and testing laboratories. DOE believes the 
current method for accounting for ambient temperature allows for 
sufficiently accurate test results.
    Regarding heat pump water heaters, NEEA and NPCC urged DOE to 
require testing under a variety of conditions due to differing average 
temperature and humidity conditions found in the northern climates. 
(NEEA and NPCC, No. 64 at p. 10) HTP submitted a comment stating that 
heat pump water heaters should be tested at a range of ambient 
conditions due to their sensitivity to temperature and humidity. (HTP, 
No. 59 at pp. 6-7) The Joint Comment suggested a representative 
temperature of 50[emsp14][deg]F ``with appropriately high humidity 
levels,'' thereby reflecting installations in cool basements and 
garages. (Joint Comment, No. 77 at p. 5)
    After carefully considering these comments, DOE has decided to 
maintain the current ambient dry bulb temperature of 67.5[emsp14][deg]F 
 1[emsp14][deg]F and adopt the proposed relative humidity 
of 50 percent  2 percent for heat pump water heaters. DOE 
recognizes that regional differences in ambient dry bulb temperature 
and relative humidity exist and that these differences can have an 
effect on the efficiency of heat pump water heaters. However, DOE has 
determined that the conditions established in this final rule are 
representative of the country as a whole and that testing of heat pump 
water heaters at various temperature and humidity conditions is 
unnecessary to determine the efficiency under a representative set of 
conditions. DOE also notes that adding multiple rating points for heat 
pump water heaters would increase test burden significantly.
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 proposed in the November 2013 NOPR to require that the 
area be protected from drafts of more than 50 ft/min (2.5 m/s). 78 FR 
66202, 66220 (Nov. 4, 2013). 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.'' DOE 
did not receive any comments opposing this proposal, but the Department 
did receive one comment indicating that a typographical error was 
present in the NOPR's conversion from ft/min to m/s. (A.O. Smith No. 62 
at p. 5) DOE is adopting the provision in its corrected form, which 
requires that the area be protected from drafts of more than 50 ft/min 
(0.25 m/s).

F. Storage Tank Pre-Conditioning

    In the November 2013 NOPR, DOE tentatively concluded that 
initiating draw patterns on two consecutive days, with measurements 
only taking place during the second 24-hour period would lead to more 
consistent results since the state of the water heater at the beginning 
of the 24-hour test period on the second day will be similar to that at 
the end of that test period. 78 FR 66202, 66221 (Nov. 4, 2013). Thus, 
DOE tentatively proposed to require storage water heaters to be pre-
conditioned in this manner.
    DOE received ten comments in response to the November 2013 NOPR 
regarding the proposed water heater pre-conditioning requirements. AET 
and the Joint Comment stated there was no significant burden associated 
with a 24-hour simulated-use-test preconditioning. However, AHRI, A.O. 
Smith, Giant, HTP, NEEA and NPCC, Rheem, and SMT stated that there is a 
significant burden associated with this requirement. (AET, No. 58 at p. 
12; AHRI, No. 75 at p. 3; A.O. Smith, No. 62 at p. 3; Giant, No. 76 at 
p. 3; HTP, No. 59 at p. 2; NEEA and NPCC, No. 64 at p. 4; Joint 
Comment, No. 77 at p. 6; Rheem, No. 69 at p. 4) Bradford White 
(referring to comments submitted by AHRI in response to the January 
2013 RFI that suggested the adoption of the pre-conditioning period 
proposed in the NOPR) commented that the AHRI comments were originally 
proposed in an effort to remove use of an internal tank temperature 
probe, which is no longer included in the test procedure. (Bradford 
White, No. 61 at p. 9) Eight commenters (AHRI, A.O. Smith, Bradford 
White, Giant, HTP, NEEA and NPCC, Joint Comment, Rheem) recommended 
continuing the use of the current preconditioning procedures. DOE notes 
that these commenters include AHRI, the commenter that originally 
suggested the 24-hour simulated-use-preconditioning. (AHRI, No. 75 at 
p. 3; A.O. Smith, No. 62 at p. 3; Bradford White, No. 61 at p. 9; 
Giant, No. 76 at p. 3; HTP, No. 59 at p. 2; NEEA and NPCC, No. 64 at p. 
4; Joint Comment, No. 77 at p. 6; Rheem, No. 69 at p. 4)
    DOE has considered these comments and has determined that the added 
burden of mandating a 24-hour preconditioning as described above 
outweighs the potential benefits that could be provided by such an 
approach. However, DOE has determined that some specification of test 
preparation is needed to improve the reproducibility of the test 
results. First, DOE has found that a storage water heater must be 
maintained with its stored water at a temperature typically seen during 
normal operation for a period of time (a ``soak-in period'') prior to 
the start of any test to ensure that the materials making up the water 
heater reach a relatively steady temperature. Comments from the 
December 2013 Public Meeting indicated that such an approach is 
currently a best practice in testing water heaters and that this soak-
in period can be conducted while the water heater is not connected to a 
test apparatus. (Public Meeting Transcript, No. 81 at p. 82) This 
latter point reduces the need for an additional test apparatus to 
maintain the rate of testing that is currently achieved in laboratories 
and will, therefore, minimize the need to purchase additional test 
equipment to meet the requirements of the new test procedure. After a 
computational analysis of heat transfer through the walls of a storage 
water heater, DOE has determined that a soak-in period of at least 12 
hours will minimize transient heat transfer effects. Therefore, DOE 
adopts a requirement that a storage water heater (including heat pump 
water heaters with storage volume) sit in an idle state (i.e., no water 
draws) with water stored in it for a minimum of 12 hours following the 
end of recovery from a cold start prior to conducting either a first-
hour rating test or a simulated-use test.
    Second, DOE has found that a water heater must not undergo a 
recovery immediately prior to the start of the 24-hour simulated-use 
test because the recovery will add significant

[[Page 40558]]

uncertainty to the critical measurement of average tank temperature at 
the start of the test. Consequently, DOE adopts a requirement that the 
24-hour simulated-use test be preceded by at least a one-hour period 
during which all heat sources to the water in the tank do not energize. 
DOE concludes that incorporating these requirements will help ensure 
reproducible test results without being unduly burdensome.

G. Operational Mode Selection

    In the November 2013 NOPR, DOE noted that heat pump water heaters 
that have recently entered the market typically have multiple 
operational modes and that selection of the operational mode could 
impact the results of energy efficiency testing. 78 FR 66202, 66234 
(Nov. 4, 2013). As a result, DOE proposed that water heaters should be 
tested under the default or ``out-of-the-box'' mode of operation when 
both obtaining the first-hour rating and determining the energy factor. 
In addition, DOE proposed several clarifications for testing of units 
with multiple operational modes but no default mode. The clarifications 
are consistent with guidance issued by DOE on June 12, 2012 (see: 
http://www1.eere.energy.gov/guidance/detail_search.aspx?IDQuestion=623&pid=2&spid=1). DOE did not receive any 
comments related to this proposal in response to the November 2013 NOPR 
and adopts the proposed requirements without change.

H. 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. As discussed in the November 2013 
NOPR, AHRI submitted a letter to the FTC on September 16, 2013, 
pointing 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 different water heater models with the same energy factor 
rating. 78 FR 66202, 66220-21 (Nov. 4, 2013). AHRI provided an example 
of two water heaters with differing daily energy consumption values but 
with energy factor 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 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 energy factor rating.
    In the November 2013 NOPR, DOE proposed 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. Id. at 66221. NEEA and 
NPCC strongly opposed any calculation of annual energy use for water 
heaters, arguing that the calculation of annual energy use is 
misleading in a large number of instances due to wide variations in 
annual household hot water use. (NEEA and NPCC, No. 64 at p. 16)
    Although DOE agrees with NEEA and NPCC that the actual annual 
energy consumption of water heaters can vary widely based on variations 
in field conditions, DOE believes that calculating an estimated annual 
energy consumption based on the results of the test procedure can 
provide consumers with valuable information for comparing two water 
heaters under a standard set of conditions (i.e., those conditions 
defined in the DOE test procedure). DOE believes that this additional 
metric can provide consumers who are unfamiliar with the uniform energy 
factor metric with a more familiar and easier-to-understand metric for 
comparing water heater performance. For this reason, DOE chooses to 
retain the calculation of annual energy consumption proposed in the 
November 2013 NOPR.

I. Conversion of Existing Energy Factor Ratings

    AEMTCA amended EPCA to require that, along with developing a 
uniform descriptor, DOE must also develop a mathematical conversion 
factor to translate the results based upon use of the efficiency metric 
under the existing test procedure to the new 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 
manufactured 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 
must translate existing ratings from the current metrics to the new 
metric, while maintaining the stringency of the current standards.
    In response to the November 2013 NOPR, DOE received three comments 
(AHRI, BWC, Joint Comment) regarding the conversion of existing 
ratings. (AHRI, No. 75 at p. 6-7; BWC, No. 61 at p. 7; Joint Comment, 
No. 77 at p. 2) AHRI and BWC suggested water heater types to test and 
urged DOE to release a schedule and process for the development of the 
conversion factor as soon as possible. The Joint Comment suggested that 
the sensitivity of the energy factor to draw pattern should be 
investigated and that systematic differences between ``old'' and 
``new'' values were expected for several technologies.
    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. DOE also plans to translate its current energy conservation 
standards to equivalent standards denominated in the new uniform 
efficiency metric in a separate rulemaking. Should it become apparent 
in the rulemaking to establish the conversion factor that changes may 
be required in the test procedure, DOE will address these issues at 
that time.

J. Full Fuel Cycle

    In response to the November 2013 NOPR, 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. 63 at p. 4) AGA and 
NPGA 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. 68 at p. 1; NPGA, 
No. 60 at p. 1)
    In the November 2013 NOPR, DOE responded in detail to similar 
concerns brought forth by stakeholders in response to the January 2013 
RFI. In short, DOE reviewed the proposed water heater test procedure in 
relation to the Department's newly established full fuel cycle (FFC) 
policy, and tentatively concluded that no substantive amendments are 
needed to the water heater test procedure to accommodate the FFC 
policy. 78 FR 66202, 66222 (Nov. 4, 2013). However, for the purposes of 
representations, DOE tentatively concluded that some small improvements 
to the water heater test procedure are appropriate to

[[Page 40559]]

accommodate the FFC policy. DOE proposed in the November 2013 NOPR to 
define new terms in the test procedure to make it possible 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 allows the user of 
the test procedure to estimate the 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).
    In response to the November 2013 NOPR, DOE received seven comments 
regarding 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. Four commenters supported the addition of these terms 
(AET, AIM, Joint Comment, NPGA), while three commenters did not (EEI, 
HTP, AHRI). (AET, No. 58 at p. 15; AIM, No. 74 at p. 1; EEI, No. 63 at 
p. 4; HTP, No. 59 at p. 5; Joint Comment, No. 77 at p. 7; NPGA, No. 60 
at p. 1-2; AHRI No. 80 at p. 2) EEI stated that it is not clear whether 
a separation by fuel type will be meaningful to the customer; HTP and 
AHRI argued that these terms are unnecessary.
    After considering these comments, DOE has decided to include terms 
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). DOE believes these 
added terms will provide consumers with more accurate information for 
comparing various water heating technologies without significantly 
adding to the overall test burden.

K. Certification, Compliance, and Enforcement Issues

1. Storage Volume Requirements
    In the November 2013 NOPR, DOE proposed to make several changes to 
its certification, compliance, and enforcement regulations at 10 CFR 
part 429. First, DOE proposed to add requirements to 10 CFR 429.17 that 
the rated value of storage tank volume must equal the mean of the 
measured storage volumes of the units in the sample. 78 FR 66202, 66223 
(Nov. 4, 2013). DOE notes that there are currently no requirements from 
the Department limiting the allowable difference 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 measured storage volume. For gas-fired 
water heaters, the rated volume ranged from 1.5 percent 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 believes consumers often look to storage volume as a key factor in 
choosing a storage water heater. Consequently, DOE proposed to adopt 
requirements that the rated value must be the mean of the measured 
values. In addition, DOE proposed to specify that for DOE-initiated 
testing, the measured storage volume must be within five percent of the 
rated volume in order to use the rated storage volume in downstream 
calculations. Id. If the measured storage volume is more than five 
percent different than the rated value, then DOE proposed to use the 
measured value in downstream calculations. DOE proposed to specify 
similar requirements for residential-duty commercial water heaters.
    AHRI, A.O. Smith, Bradford White, HTP, the Joint Comment, and Rheem 
opposed the proposal to require that the rated storage value be the 
mean of the measured values. (AHRI, No. 75 at p. 4; A.O. Smith, No. 62 
at p. 3; Bradford White, No. 61 at p. 10; HTP, No. 59 at p. 8; Joint 
Comment, No. 77 at p. 3; Rheem, No. 69 at p. 6) AHRI argued that the 
proposal is unnecessary and not an efficiency-related matter, but a 
safety matter. As such, AHRI argued that it is outside the scope of the 
DOE's authority and has been adequately addressed in ANSI Z21 and the 
UL standards for water heaters. AHRI stated that there are currently no 
units on the market that would allow the difference between rated and 
measured volume to dodge the minimum efficiency standards. A.O. Smith 
and Bradford White noted that adding this requirement would make a 
water heater which was legal under the old test procedure illegal, 
which in turn would necessitate updating the minimum efficiency 
standards. HTP stated that the five-percent tolerance on the measured 
storage volume as compared to rated storage volume is too stringent and 
would impose a significant re-design burden upon manufacturers. HTP 
instead suggests a ten-percent tolerance to reduce the manufacturer's 
burden.
    After carefully considering these comments, DOE has decided to 
require that the rated storage volume be based on the mean of the 
measured values. The efficiency of a water heater is clearly related to 
the rated storage volume and, therefore, within DOE's authority to 
regulate. DOE seeks to eliminate any potential incentives for 
manufacturers to continue the current practice of exaggerating the 
storage volume of water heaters currently on the market by inflating 
the rated volume as compared to the actual measured volume. While DOE 
acknowledges AHRI's assessment that no current water heaters on the 
market could evade minimum efficiency standards, this does not rule out 
the possibility that future water heaters could do so; the revised 
approach adopted in this final rule addresses this concern going 
forward. Regarding the comment from A.O. Smith and Bradford White that 
adding this requirement would make a water heater which was legal under 
the old test procedure illegal, DOE notes that if AHRI's comment about 
the current water heater market is correct, the difference between 
rated and measured volume should not cause any water heaters to be 
subject to different energy conservation standards, thereby rendering 
such concerns theoretical. Furthermore, there will be a mathematical 
conversion for water heater models that are currently compliant to 
transition from results generated under the old test procedure to the 
new test procedure. Additionally, DOE-initiated testing will require 
that all measured storage volumes be within 5 percent of 
the rated storage volume to be considered valid. DOE agrees with

[[Page 40560]]

HTP that the 5 percent tolerance will result in manufacturers having to 
rerate certain models at an additional burden. However, DOE has 
concluded that any tolerance greater than 5 percent will not have the 
desired effect of harmonizing rated and measured storage volume values, 
and it is likely that a significant gap would persist between the 
values if a larger tolerance were adopted. If an invalid storage volume 
is found, the measured storage volume will be used in determining the 
applicable minimum energy conservation standard and calculations within 
the test procedure.
2. First-Hour Rating and Maximum GPM Requirements
    Because the first-hour and maximum GPM ratings will determine the 
applicable draw pattern for use during the uniform energy factor test, 
DOE proposed in the November 2013 NOPR to include rating requirements 
for those values. 78 FR 66202, 66223 (Nov. 4, 2013). DOE proposed that 
the 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. For DOE testing, the rated value will be considered 
valid if it is within five percent of the measured value. In such a 
case, DOE proposed that the rated value would be used for the purposes 
of choosing the appropriate draw pattern for the uniform energy factor 
test. In the case of an invalid rating (i.e., the first-hour rating or 
maximum GPM rating is more than five percent different from the 
measured value), DOE proposed to use the measured value to determine 
the applicable draw pattern for the uniform energy factor test. DOE did 
not receive any comments objecting to these proposals, and, thus, DOE 
is adopting them in this final rule.
3. Ratings for Untested Models
    In reviewing the current test procedure, DOE has concluded that 10 
CFR part 430, subpart B, appendix E, section 7.0, ``Ratings for 
Untested Models,'' is more appropriately addressed in 10 CFR part 429, 
which deals with requirements for certification of residential water 
heaters, than in the test procedure. In the November 2013 NOPR, DOE 
proposed to remove this section from Appendix E and place a similar 
section in 10 CFR 429.17. 78 FR 66202, 66223-24 (Nov. 4, 2013). DOE 
proposed to maintain the same requirements for gas water heaters in 10 
CFR 429.17 that were previously in section 7.0, which allow units using 
propane gas that have an input rating within 10 percent of an otherwise 
identical natural gas unit to use the rating for the natural gas unit 
in lieu of separate testing. DOE did not receive any comments related 
to this proposal, and thus, DOE adopts it in this final rule; however, 
DOE has moved the provision to 10 CFR 429.70 to reflect that this is an 
alternative method of determining efficiency (in lieu of testing).
    DOE also proposed 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. 78 FR 66202, 
66224 (Nov. 4, 2013). 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 a single standard 
input rating. It also 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. As noted above, DOE 
proposed 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. Under the revised test procedure, the 
applicable draw pattern for the uniform energy factor test is based on 
the first-hour rating. Thus, the first-hour rating must be accurate for 
the tested model to ensure accurate test results for the uniform energy 
factor test.
    In response to the November 2013 NOPR, DOE received five comments 
(AHRI, BWC, Giant, Joint Comment, Rheem) opposing the proposal to 
remove the manufacturer's ability to designate electric water heaters 
that are identical except for their respective input ratings as having 
a standard input, and one comment was received from HTP suggesting 
alternate methods of testing the units with different input ratings. 
(AHRI, No. 75 at p. 7; BWC, No. 61 at p. 10-11; Giant, No. 76 at p. 3-
4; HTP, No. 79 at p. 1-6; Joint Comment, No. 77 at p. 7; Rheem, No. 69 
at p. 7). The five opposing comments stated that there would be a 
significant undue test burden associated with testing each model with a 
different input rating. Id. AHRI and Giant stated that the only case 
where a different input rating might be a concern is if the change in 
input rating results in a lower first-hour rating such that the unit 
would be tested under a different draw pattern than the unit with a 
``standard'' input rating. (AHRI, No. 75 at p. 7; Giant, No. 76 at p. 
3-4).
    DOE agrees that removing the provisions for rating electric water 
heaters with different input ratings could cause significant additional 
test burden for manufacturers. Thus, DOE is adopting the following 
requirements, which are roughly based on the method recommended by HTP 
to lessen burden while still ensuring that the ratings are 
representative of a model's efficiency and capacity. DOE is adopting 
provisions in 10 CFR 429.70 that will allow manufacturers to use the 
first-hour rating and uniform energy factor determined by testing one 
basic model to rate other basic models, in certain, limited 
circumstances. Untested basic models with input ratings higher than the 
rating of the tested basic model can be assumed to have the same first-
hour rating and uniform energy factor and may be rated as such. For 
untested basic models that only differ from the tested basic model in 
that they contain heating elements with input ratings below the tested 
basic model, the untested basic model with the lowest input rating for 
all heating elements must be tested for first-hour rating. If that 
untested basic model has a first-hour rating that would group it in the 
same draw pattern bin as the tested basic model, then all basic models 
with lower input ratings than the tested basic model may be assumed to 
have the same uniform energy factor as the tested basic model. These 
untested basic models can be assigned a first-hour rating equivalent to 
the volume removed in the first draw of the first-hour rating test of 
the tested basic model of electric water heater. However, if the unit 
with the lowest input rating has a first-hour rating that would result 
in classification in a draw pattern with a lower total volume drawn per 
day for the simulated-use test, the unit must be tested according to 
that lower draw pattern. At this point, the manufacturer may choose to 
test a second basic model that would represent water heaters in the 
lower sizing bin and apply the same principles noted above to determine 
the uniform energy factor and first-hour rating.
    DOE notes that the alternative efficiency determination method 
(AEDM) provisions for these consumer water heaters and residential-duty 
commercial water heaters are quite different from AEDM provisions for 
other types of covered products and equipment for which use of an AEDM 
is authorized. Specifically, these AEDM provisions do not permit any 
type of modeling or calculations of efficiency; they only permit use of 
a rating determined by testing to be used for

[[Page 40561]]

other basic models that meet certain criteria. In addition, DOE notes 
that the tested basic model will be indicated in a certification report 
with the number of units tested, while the untested basic models will 
be indicated in a certification report as having been certified using 
an AEDM.

L. Reference Standards

    DOE's test procedure for residential water heaters currently 
references two industry standards: (1) American Society for Testing and 
Measurement (ASTM) D2156-80, ``Smoke Density in Flue Gases from Burning 
Distillate Fuels, Test Method for'' and (2) ASHRAE Standard 41.1-1986, 
``Standard Measurement Guide: Section on Temperature Measurements.''
    DOE retains these references in the uniform efficiency descriptor 
test method, but updates the referenced standards to the most recent 
versions: (1) ASTM D2156-09, ``Standard Test Method for Smoke Density 
in Flue Gases from Burning Distillate Fuels'' and (2) ASHRAE Standard 
41.1-1986 (RA2006), ``Standard Method for Temperature Measurement.'' 
For the November 2013 NOPR, DOE reviewed both of the updated standards 
and concluded that their adoption would not substantially impact the 
revised test method. 78 FR 66202, 66224 (Nov. 4, 2013). DOE did not 
receive any comments on this issue in response to the NOPR, and 
consequently, DOE incorporates these industry standards by reference 
into DOE's regulations for the water heaters test procedure.

M. 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, 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.I) and developed in a subsequent 
rulemaking 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 one year after the date of publication of the 
conversion factor or December 31, 2015. (42 U.S.C. 6295(e)(5)(E)(v)) 
Thus, the test procedure final rule will become effective one year 
after its publication, 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 until such time as use of the amended 
test procedure is required. The current 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, 2014. The current 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, 2014. 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. (Note, in this final rule, DOE provides that the 
conversion factor may be used until December 31, 2015, but DOE will 
amend that date, if necessary, upon publication of the conversion 
factor final rule.) DOE notes that during the interim period, 
manufacturers must use the same version of the test procedure for all 
representations of energy efficiency, including certifications of 
compliance.

N. Other Issues

    At the December 6, 2013 public meeting, AIM and EEI requested 
clarification on the applicability of the first-hour rating and maximum 
GPM test for water heaters that may have a storage volume above 2 
gallons but which also have heating elements or burners that are 
designed to deliver a continuous flow of hot water. (Public transcript, 
p. 80-81, 84-86, 121-122) After considering these comments, DOE 
acknowledges that it may be possible to improve the test procedure's 
specifications as to which tests must be conducted on each water 
heater, so the Department is clarifying the proper implementation of 
the applicable tests as part of this final rule.
    The proposed test procedure stated that storage water heaters 
should be tested to obtain a first-hour rating and that instantaneous 
water heaters be tested to obtain a maximum GPM rating. 78 FR 66202, 
66234-36 (Nov. 4, 2013). As noted by AIM, ``flow-dominated'' or ``heat-
on-demand'' water heaters exist that have very large burners but have 
some storage volume as a buffer. (AIM No. 70 at p. 2) DOE believes that 
the delivery capacity of such water heaters is best captured by a 
maximum GPM rating and is, thus, requiring water heaters with a heating 
input that is activated by the flow of water through them to be tested 
according to the maximum GPM test procedure regardless of storage 
volume. For all other storage water heaters, the first-hour rating test 
is to be applied to determine delivery capacity. DOE is using the term 
``flow-activated'' in this final rule and is adding a definition for 
that term in the test procedure that is consistent with the definition 
of ``instantaneous water heater'' currently at 10 CFR 430.2.
    For determining the uniform energy factor, DOE believes that any 
water heater with a storage volume greater than or equal to 2 gallons 
must be tested to account for the storage volume, even if they meet 
EPCA's definition of an instantaneous water heater, which does not 
limit the stored volume. (42 U.S.C. 6291(27)(B)) The reason for this 
determination is that changes in the stored energy in the water heater 
and variations in the heat loss from the water heater to the ambient 
can affect the uniform energy factor, and the test procedure proposed 
for storage water heaters captures these effects while that for 
instantaneous water heaters does not. While it might be possible to 
include such terms in the proposed test procedure for instantaneous 
water heaters, such a step would add no benefit for instantaneous water 
heaters with minimal storage volume and could be considered as adding 
an undue burden to the testing of those units. Therefore, DOE clarifies 
the applicability of the simulated-use test based on rated storage 
volume instead of by the terminology of ``storage'' versus 
``instantaneous'' in section 5 of appendix E.

[[Page 40562]]

    DOE also clarifies the determination of the UA value to account for 
situations where the maximum tank temperature is achieved immediately 
following the recovery following the first draw cluster. As noted 
above, test data suggest that starting the standby period immediately 
following a recovery can lead to erroneous results due to the 
challenges in determining the average stored water temperature at that 
time. DOE has adjusted the start of the period used to determine the UA 
so that it must begin no less than five minutes following the end of 
the first recovery following the first draw cluster.

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 
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: http://energy.gov/gc/office-general-counsel.
    This final rule prescribes test procedure amendments 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 amendments 
establish a uniform efficiency descriptor which is 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 this final 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. The SBA size standards, listed by North 
American Industry Classification System (NAICS) code and industry 
description, are codified at 13 CFR part 121 and are available at 
http://www.sba.gov/content/table-small-business-size-standards. 
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 
333318--``Other Commercial and Service Industry Machinery 
Manufacturing,'' for which SBA also sets a size threshold of 1,000 
employees or fewer for being considered a small business.
    DOE has identified 19 manufacturers of residential water heaters 
(including manufacturers of products that fall under the expanded 
scope) that can be considered small businesses. DOE identified seven 
manufacturers of ``residential-duty'' water heaters that can be 
considered small businesses. Six of the ``residential-duty'' water 
heater manufacturers also manufacture residential water heaters, so the 
total number of water heater manufacturers impacted by this rule would 
be 20. DOE's research involved reviewing several industry trade 
association membership directories (e.g., AHRI), product databases 
(e.g., AHRI, CEC, and ENERGY STAR databases), individual company Web 
sites, and marketing research tools (e.g., Hoovers reports) to create a 
list of all domestic small business manufacturers of products covered 
by this rulemaking.
    For the reasons explained below, DOE has concluded that the test 
procedure amendments contained in this final rule would not have a 
significant economic impact on any manufacturer, including small 
manufacturers.
    For residential water heaters, the amendments adopted in this final 
rule apply primarily to the draw pattern and outlet water 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[emsp14][deg]F. This final rule will 
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 an outlet water temperature of 125[emsp14][deg]F. The change 
in outlet water 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 changes will likely 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 new test method, the length of the test 
would not change. The new test method does specify a 12-hour soak-in 
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 and would not necessitate 
the development of additional test platforms. DOE understands that a 
preconditioning period is already implemented by manufacturers as a 
best practice to allow the water heater to achieve operational 
temperature, so the added burden from the 12-hour soak-in would be 
minimal. In addition, these tests can be

[[Page 40563]]

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 final 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 uniform energy 
factor in this final rule. The uniform 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 
uniform 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 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 updates will cause significant additional burdens for these 
manufacturers.
    Accordingly, DOE concludes and certifies that this final rule would 
not have a significant economic impact on a substantial number of small 
entities, so DOE has not prepared a regulatory flexibility analysis for 
this rulemaking. DOE has provided 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 procedures 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 
the certification and recordkeeping is subject to review and approval 
by OMB under the Paperwork Reduction Act (PRA). This requirement has 
been approved by OMB under OMB control number 1910-1400. Public 
reporting burden for the certification is estimated to average 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 final rule, DOE amends its test procedure 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 rule amends an existing rule without affecting the 
amount, quality or distribution of energy usage, and, therefore, will 
not result in any environmental impacts. Thus, this rulemaking is 
covered by Categorical Exclusion A5 under 10 CFR part 1021, subpart D, 
which applies to any rulemaking that interprets or amends an existing 
rule without changing the environmental effect of that rule. 
Accordingly, neither an environmental assessment nor an environmental 
impact statement is required.

E. Review Under Executive Order 13132

    Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 10, 
1999), imposes certain requirements on agencies formulating and 
implementing policies or regulations that preempt State law or that 
have Federalism implications. The Executive Order requires agencies to 
examine the constitutional and statutory authority supporting any 
action that would limit the policymaking discretion of the States and 
to carefully assess the necessity for such actions. The Executive Order 
also requires agencies to have an accountable process to ensure 
meaningful and timely input by State and local officials in the 
development of regulatory policies that have Federalism implications. 
On March 14, 2000, DOE published a statement of policy describing the 
intergovernmental consultation process it will follow in the 
development of such regulations. 65 FR 13735. DOE examined this final 
rule and determined that it will not have a substantial direct effect 
on the States, on the relationship between the national government and 
the States, or on the distribution of power and responsibilities among 
the various levels of government. EPCA governs and prescribes Federal 
preemption of State regulations as to energy conservation for the 
products that are the subject of this final 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.

[[Page 40564]]

F. Review Under Executive Order 12988

    Regarding the review of existing regulations and the promulgation 
of new regulations, section 3(a) of Executive Order 12988, ``Civil 
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal 
agencies the general duty to adhere to the following requirements: (1) 
Eliminate drafting errors and ambiguity; (2) write regulations to 
minimize litigation; (3) provide a clear legal standard for affected 
conduct rather than a general standard; and (4) promote simplification 
and burden reduction. Regarding the review required by section 3(a), 
section 3(b) of Executive Order 12988 specifically requires that 
Executive agencies make every reasonable effort to ensure that the 
regulation: (1) Clearly specifies the preemptive effect, if any; (2) 
clearly specifies any effect on existing Federal law or regulation; (3) 
provides a clear legal standard for affected conduct while promoting 
simplification and burden reduction; (4) specifies the retroactive 
effect, if any; (5) adequately defines key terms; and (6) addresses 
other important issues affecting clarity and general draftsmanship 
under any guidelines issued by the Attorney General. Section 3(c) of 
Executive Order 12988 requires Executive agencies to review regulations 
in light of applicable standards in sections 3(a) and 3(b) to determine 
whether they are met or it is unreasonable to meet one or more of them. 
DOE has completed the required review and determined that, to the 
extent permitted by law, this final 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. Pub. L. 104-4, sec. 201 (codified at 2 U.S.C. 1531). 
For a regulatory action resulting in a rule that may cause the 
expenditure by State, local, and Tribal governments, in the aggregate, 
or by the private sector of $100 million or more in any one year 
(adjusted annually for inflation), section 202 of UMRA requires a 
Federal agency to publish a written statement that estimates the 
resulting costs, benefits, and other effects on the national economy. 
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to 
develop an effective process to permit timely input by elected officers 
of State, local, and Tribal governments on a ``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 http://energy.gov/gc/office-general-counsel.) DOE examined this final rule 
according to UMRA and its statement of policy and has 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 final rule will not have any impact on the autonomy or integrity 
of the family as an institution. Accordingly, DOE has concluded that it 
is not necessary to prepare a Family Policymaking Assessment.

I. Review Under Executive Order 12630

    Pursuant to Executive Order 12630, ``Governmental Actions and 
Interference with Constitutionally Protected Property Rights,'' 53 FR 
8859 (March 18, 1988), DOE has determined that this regulation will not 
result in any takings that might require compensation under the Fifth 
Amendment to the U.S. Constitution.

J. Review Under Treasury and General Government Appropriations Act, 
2001

    Section 515 of the Treasury and General Government Appropriations 
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most 
disseminations of information to the public under information quality 
guidelines established by each agency pursuant to general guidelines 
issued by OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 
2002), and DOE's guidelines were published at 67 FR 62446 (Oct. 7, 
2002). DOE has reviewed this final 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 significant energy action, the 
agency must give a detailed statement of any adverse effects on energy 
supply, distribution, or use if the regulation is implemented, and of 
reasonable alternatives to the action and their expected benefits on 
energy supply, distribution, and use.
    This regulatory action to amend the test procedure for measuring 
the energy efficiency of residential 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

[[Page 40565]]

impact of the commercial or industry standards on competition.
    The modifications to the test procedures addressed by this action 
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 this 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 has consulted 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 and has received no comments objecting to their use.

M. Congressional Notification

    As required by 5 U.S.C. 801, DOE will report to Congress on the 
promulgation of this rule before its effective date. The report will 
state that it has been determined that the rule is not a ``major rule'' 
as defined by 5 U.S.C. 804(2).

V. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this final 
rule.

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 June 27, 2014.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy Efficiency, Energy Efficiency and 
Renewable Energy.
    For the reasons stated in the preamble, DOE amends 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:
0
a. Revising paragraphs (a) introductory text and (a)(1);
0
b. Redesignating paragraphs--
    i. (a)(2)(i) introductory text as (a)(1)(ii)(A);
    ii. (a)(2)(i)(A) as (a)(1)(ii)(A)(1);
    iii. (a)(2)(1)(B) as (a)(1)(ii)(A)(2);
    iv. (a)(2)(ii) introductory text as (a)(1)(ii)(B);
    v. (a)(2)(ii)(A) as (a)(1)(ii)(B)(1); and
    vi. (a)(2)(ii)(B) as (a)(1)(ii)(B)(2);
0
c. Adding paragraphs (a)(1)(ii)(C), and (D);
0
d. Revising paragraph (a)(2); and
0
e. Revising paragraph (b)(2).
    The revisions and additions read as follows:

Sec.  429.17  Residential water heaters.

    (a) Determination of represented value. Manufacturers must 
determine the represented value, which includes the certified rating, 
for each basic model of residential water heater either by testing, in 
conjunction with the applicable sampling provisions, or by applying an 
alternative efficiency determination method (AEDM) approved for use by 
DOE.
    (1) Units to be tested. (i) If the represented value is determined 
through testing, the general requirements of Sec.  429.11 are 
applicable; and
    (ii) For each basic model selected for testing, a sample of 
sufficient size shall be randomly selected and tested to ensure that--
* * * * *
    (C) Any represented value of the rated storage volume must be equal 
to the mean of the measured storage volumes of all the units within the 
sample.
    (D) Any represented value of first-hour rating or maximum gallons 
per minute (GPM) must be equal to the mean of the measured first-hour 
ratings or measured maximum GPM ratings, respectively, of all the units 
within the sample.
    (2) Alternative efficiency determination methods. In lieu of 
testing, represented values for a basic model must be determined 
through the application of an AEDM pursuant to the requirements of 
Sec.  429.70.
    (b) * * *
    (2) Pursuant to Sec.  429.12(b)(13), a certification report shall 
include the following public product-specific information: The uniform 
energy factor (UEF, rounded to the nearest 0.01), rated storage volume 
in gallons (gal), first-hour rating or maximum gallons per minute 
(GPM), and recovery efficiency (percent).

0
3. Section 429.44 is amended by:
0
a. Redesignating paragraphs (a), (b), and (c) as (b), (c), and (d), 
respectively.
0
b. Adding 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 residential-duty commercial water heaters, all represented 
values must be determined in accordance with Sec.  429.17.
    (b) Determination of Represented Value for All Types of Commercial 
Water Heaters Except Residential-Duty Commercial Water Heaters. 
Manufacturers must determine the represented value, which includes the 
certified rating, for each basic model of commercial water heating 
equipment except residential-duty commercial water heaters, either by 
testing, in conjunction with the applicable sampling provisions, or by 
applying an AEDM as set forth in Sec.  429.70.
* * * * *

0
4. Section 429.70 is amended by adding paragraph (g) to read as 
follows:

Sec.  429.70  Alternative methods for determining energy efficiency and 
energy use

* * * * *
    (g) Alternative determination of ratings for untested basic models 
of residential water heaters and residential-duty commercial water 
heaters. For models of water heaters that differ only in fuel type or 
power input, ratings for untested basic models may be established in 
accordance with the following procedures in lieu of testing. This 
method allows only for the use of ratings identical to those of a 
tested basic model as provided below; simulations or other modeling 
predictions for ratings of the uniform

[[Page 40566]]

energy factor, volume, first-hour rating, or maximum gallons per minute 
(GPM) are not permitted.
    (1) Gas Water Heaters. For untested basic models of gas-fired water 
heaters that differ from tested basic models only in whether the basic 
models use natural gas or propane gas, the represented value of uniform 
energy factor, first-hour rating, and maximum gallons per minute for an 
untested basic model is the same as that for a tested basic model, as 
long as the input ratings of the tested and untested basic models are 
within 10%, that is:
[GRAPHIC] [TIFF OMITTED] TR11JY14.066

    (2) Electric Storage Water Heaters. Rate an untested basic model of 
an electric storage type water heater using the first-hour rating and 
the uniform energy factor obtained from a tested basic model as a basis 
for ratings of basic models with other input ratings, provided that 
certain conditions are met:
    (i) For an untested basic model, the represented value of the 
first-hour rating and the uniform energy factor is the same as that of 
a tested basic model, provided that each heating element of the 
untested basic model is rated at or above the input rating for the 
corresponding heating element of the tested basic model.
    (ii) For an untested basic model having any heating element with an 
input rating that is lower than that of the corresponding heating 
element in the tested basic model, the represented value of the first-
hour rating and the uniform energy factor is the same as that of a 
tested basic model, provided that the first-hour rating for the 
untested basic model results in the same draw pattern specified in 
Table I of appendix E for the simulated-use test as was applied to the 
tested basic model. To establish whether this condition is met, 
determine the first-hour ratings for the tested and the untested basic 
models in accordance with the procedure described in section 5.3.3 of 
10 CFR part 430, subpart B, appendix E, then compare the appropriate 
draw pattern specified in Table I of appendix E for the first-hour 
rating of the tested basic model with that for the untested basic 
model. If this condition is not met, then the untested basic model must 
be tested and the appropriate sampling provisions applied to determine 
its uniform energy factor in accordance with appendix E and this part.

0
5. Section 429.134 is amended by removing and reserving paragraph (c) 
and adding paragraph (d) to read as follows:

Sec.  429.134  Product-specific enforcement provisions.

* * * * *
    (d) Residential Water Heaters and Residential-Duty Commercial Water 
Heaters--(1) Verification of first-hour rating and maximum GPM rating. 
The first-hour rating or maximum gallons per minute (GPM) rating of the 
basic model will be measured pursuant to the test requirements of 10 
CFR part 430 for each unit tested. The mean of the measured values will 
be compared to the rated values of first-hour rating or maximum GPM 
rating as 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 rated value of first-hour rating or maximum GPM rating 
is found to be within 5 percent of the mean of the measured values, 
then the rated value will be used as the basis for determining the 
applicable draw pattern pursuant to the test requirements of 10 CFR 
part 430 for each unit tested.
    (ii) If the rated value of first-hour rating or maximum GPM rating 
is found to vary more than 5 percent from the measured values, then the 
mean of the measured values will serve as the basis for determining the 
applicable draw pattern pursuant to the test requirements of 10 CFR 
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 10 
CFR part 430 for each unit tested. The mean of the measured values will 
be compared to the rated storage volume as certified by the 
manufacturer. The rated value will be considered valid only if the 
measurement is within five percent of the certified rating.
    (i) If the rated storage volume is found to be within 5 percent of 
the mean of the measured value of storage volume, then that value will 
be used as the basis for calculation of the required uniform energy 
factor for the basic model.
    (ii) If the rated storage volume is found to vary more than 5 
percent from the mean of the measured values, then the mean of the 
measured values will be used as the basis for calculation of the 
required uniform energy factor for the basic model.

PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

0
6. The authority citation for part 430 continues to read as follows:

    Authority:  42 U.S.C. 6291-6309; 28 U.S.C. 2461 note.

0
7. Section 430.2 is amended by adding the definitions of ``Electric 
heat pump water heater,'' ``Electric instantaneous water heater,'' 
``Electric storage water heater,'' ``Gas-fired instantaneous water 
heater,'' ``Gas-fired storage water heater,'' ``Gas-fired heat pump 
water heater,'' ``Oil-fired instantaneous water heater,'' and ``Oil-
fired storage water heater'' in alphabetical order to read as follows:

Sec.  430.2  Definitions.

* * * * *
    Electric heat pump water heater means a water heater that uses 
electricity as the energy source, 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) at an input voltage of no greater than 250 volts, has a rated 
storage capacity of 120 gallons (450 liters) or less, is designed to 
transfer thermal energy from one temperature level to a higher 
temperature level for the purpose of heating water, including all 
ancillary equipment such as fans, storage tanks, pumps, or controls 
necessary for the device to perform its function, and is designed to 
heat and store water at a thermostatically-controlled temperature less 
than or equal to 180 [deg]F (82 [deg]C).
* * * * *
    Electric instantaneous water heater means a water heater that uses 
electricity as the energy source, has a nameplate input rating of 12 kW 
(40,956 Btu/h) or less, contains no more than one gallon of water per 
4,000 Btu per hour of input, and is designed to provide outlet water at 
a controlled temperature less than or equal to 180 [deg]F (82 [deg]C). 
The unit may use a fixed or variable burner input.
* * * * *

[[Page 40567]]

    Electric storage water heater means a water heater that uses 
electricity as the energy source, has a nameplate input rating of 12 kW 
(40,956 Btu/h) or less, has a rated storage capacity of 120 gallons 
(450 liters) or less, contains more than one gallon of water per 4,000 
Btu per hour of input, and may be designed to heat and store water at a 
thermostatically-controlled temperature less than or equal to 180 
[deg]F (82 [deg]C).
* * * * *
    Gas-fired heat pump water heater means a water heater that uses gas 
as the main energy source, has a nameplate input rating of 75,000 Btu/h 
(79 MJ/h) or less, has a maximum current rating of 24 amperes 
(including all auxiliary equipment such as fans, pumps, controls, and, 
if on the same circuit, any resistive elements) at an input voltage of 
no greater than 250 volts, has a rated storage volume not more than 120 
gallons (450 liters), and is designed to transfer thermal energy from 
one temperature level to a higher temperature level to deliver water at 
a thermostatically controlled temperature less than or equal to 180 
[deg]F (82 [deg]C).
    Gas-fired instantaneous water heater means a water heater that uses 
gas as the main energy source, has a nameplate input rating less than 
200,000 Btu/h (210 MJ/h), contains no more than one gallon of water per 
4,000 Btu per hour of input, and is designed to provide outlet water at 
a controlled temperature less than or equal to 180 [deg]F (82 [deg]C). 
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, has a nameplate input rating of 75,000 Btu/h 
(79 MJ/h) or less, has a rated storage capacity of 120 gallons (450 
liters) or less, contains more than one gallon of water per 4,000 Btu 
per hour of input, and is designed to heat and store water at a 
thermostatically-controlled temperature less than or equal to 
180[emsp14][deg]F (82 [deg]C).
* * * * *
    Oil-fired instantaneous water heater means a water heater that uses 
oil as the main energy source, has a nameplate input rating of 210,000 
Btu/h (220 MJ/h) or less, contains no more than one gallon of water per 
4,000 Btu per hour of input, and is designed to provide outlet water at 
a controlled temperature less than or equal to 180[emsp14][deg]F (82 
[deg]C). The unit may use a fixed or variable burner input.
    Oil-fired storage water heater means a water heater that uses oil 
as the main energy source, has a nameplate input rating of 105,000 Btu/
h (110 MJ/h) or less, has a rated storage capacity of 120 gallons (450 
liters) or less, contains more than one gallon of water per 4,000 Btu 
per hour of input, and is designed to heat and store water at a 
thermostatically-controlled temperature less than or equal to 
180[emsp14][deg]F (82 [deg]C).
* * * * *

0
8. Section 430.3 is amended by:
0
a. Redesignating paragraphs (h) through (t) as (i) through (u), 
respectively; and
0
b. Adding a new paragraph (h).
    The addition reads as follows:

Sec.  430.3  Materials incorporated by reference.

* * * * *
    (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 D 2156-09 (``ASTM D2156''), Standard Test Method for Smoke 
Density in Flue Gases from Burning Distillate Fuels, approved December 
1, 2009, IBR approved for appendix E to subpart B.
    (2) [Reserved].
* * * * *

0
9. 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: the product of the 
annual gas or oil energy consumption, determined according to section 
6.1.10 or 6.2.7 of appendix E of this subpart, times the representative 
average unit cost of gas or oil, as appropriate, in dollars per Btu as 
provided by the Secretary; plus the product of the annual electric 
energy consumption, determined according to section 6.1.9 or 6.2.6 of 
appendix E of this subpart, times the representative average unit cost 
of electricity in dollars per kilowatt-hour as provided by the 
Secretary, the resulting sum 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 uniform 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
10. 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 December 31, 2015, 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. (Because the statute permits use of a conversion factor 
until the later of December 31, 2015 or one year after publication 
of a conversion factor final rule, DOE may amend the mandatory 
compliance date for use of this amended test procedure, as 
necessary.)
    Manufacturers conducting tests of residential water heaters and 
commercial water heaters covered by this test method after July 13, 
2015, and prior to December 31, 2015, must conduct such test in 
accordance with either this appendix or the 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, 2014. 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, 
2014. 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 draws initiated 
during the simulated-use test during which no successive draws are 
separated by more than 2 hours.
    1.5. First-Hour Rating means an estimate of the maximum volume 
of ``hot'' water that a storage-type water heater can supply within

[[Page 40568]]

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.
    1.6. Flow-activated describes an operational scheme in which a 
water heater initiates and terminates heating based on sensing flow.
    1.7. Heat Trap means a device that 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[emsp14][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
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[emsp14][deg]F (37.3 [deg]C)
i--a subscript to indicate the draw number during a test
Mi--mass of water removed during the ith draw of the 24-hour 
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-hour simulated-use test
Q--total fossil fuel and/or electric energy consumed during the 
entire 24-hour 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[emsp14][deg]F--daily energy consumption to heat quantity of 
water removed during test over a temperature rise of 
67[emsp14][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[emsp14][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-hour simulated-
use test
T24--mean tank temperature at the end of the 24-hour simulated-use 
test
Ta,stby--average ambient air temperature during standby periods of 
the 24-hour simulated-use test
Tdel--for flow-activated 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-hour simulated-use test
Tin--for flow-activated 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-hour simulated-use test
Tmax,1--maximum measured mean tank temperature after cut-out 
following the first draw of the 24-hour 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
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
UEF--uniform energy factor of a water heater
Vi--volume of water removed during the ith draw (i = 1 to N) of the 
24-hour 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 flow-activated 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-hour simulated-use test

    1.14. Temperature controller means a device that is available to 
the user to adjust the temperature of the water inside a storage-
type water heater or the outlet water temperature.
    1.15. Uniform Energy Factor means the measure of water heater 
overall efficiency.

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[emsp14][deg]F and 70.0[emsp14][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[emsp14][deg]F  1[emsp14][deg]F (19.7 [deg]C  0.6 [deg]C) and the relative humidity shall be maintained at 
50%  2% throughout the test.
    2.3 Supply Water Temperature. The temperature of the water being 
supplied to the water heater shall be maintained at 58[emsp14][deg]F 
 2[emsp14][deg]F (14.4 [deg]C  1.1 [deg]C) 
throughout the test.
    2.4 Outlet Water Temperature. The temperature controllers of a 
storage-type

[[Page 40569]]

water heater shall be set so that water is delivered at a 
temperature of 125[emsp14][deg]F  5[emsp14][deg]F (51.7 
[deg]C  2.8 [deg]C).
    2.5 Set Point Temperature. The temperature controller of 
instantaneous water heaters shall be set to deliver water at a 
temperature of 125[emsp14][deg]F  5[emsp14][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:

------------------------------------------------------------------------
                                      Instrument          Instrument
          Item measured                accuracy            precision
------------------------------------------------------------------------
Gas pressure....................  0.1     0.05
                                   inch of water       inch of water
                                   column (0.025 kPa).   minus>0.012 kPa).
Atmospheric pressure............  0.1     0.05
                                   inch of mercury     inch of mercury
                                   column (0.34 kPa).    minus>0.17 kPa).
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 41.1-1986 (incorporated by reference, see Sec.  430.3).
    3.2.2 Accuracy and Precision. The accuracy and precision of the 
instruments, including their associated readout devices, shall be 
within the following limits:

------------------------------------------------------------------------
                                      Instrument          Instrument
          Item measured                accuracy            precision
------------------------------------------------------------------------
Air dry bulb temperature........  0.2[deg]F     minus>0.1[deg]F
                                   (0.1[deg]C).   minus>0.06[deg]C)
                                                       .
Air wet bulb temperature........  0.2[deg]F     minus>0.1[deg]F
                                   (0.1[deg]C).   minus>0.06[deg]C)
                                                       .
Inlet and outlet water            0.2[deg]F     minus>0.1[deg]F
                                   (0.1[deg]C).   minus>0.06[deg]C)
                                                       .
Storage tank temperatures.......  0.5[deg]F     minus>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 (0.25 m/s) from room 
ventilation registers, windows, or other external sources of air 
movement.

[[Page 40570]]

    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 of section 6.4.6 of this appendix. Inlet and outlet 
piping connections for wall-mounted water heaters shall be 
consistent with Figure 3 of section 6.4.6 of this appendix. 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, or 6 of section 
6.4.6 of this appendix. 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 of section 6.4.6 of this 
appendix, 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 of section 6.4.6 of 
this appendix must 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. Install a pressure gauge and diaphragm 
expansion tank in the supply water piping at a location upstream of 
the inlet temperature sensor. Install an appropriately rated 
pressure and temperature relief valve on all water heaters at the 
port specified by the manufacturer. Discharge piping for the relief 
valve must be non-metallic. If heat traps, piping insulation, or 
pressure relief valve insulation are supplied with the water heater, 
they must be installed for testing. Except when using a simulated 
wall, provide sufficient clearance 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 of this appendix.
    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 tank. Position a 
temperature sensor 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 
that comply with the installation requirements. Install the 
temperature sensors 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, must 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, install a substitute relief valve that has a 
sensing element that can reach into the tank. If the hot water 
outlet includes a heat trap, install the heat trap on top of the tee 
fitting. Cover any added fittings 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. 
Shield the sensor 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 of 
section 6.4.6 of this appendix, as applicable.
    4.8 Flow Control. Install a valve or valves to provide flow as 
specified in sections 5.3 and 5.4 of this appendix.
    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, connect to the 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. For gas-fired 
water heaters with a horizontally discharging draft hood outlet, 
connect to the draft hood outlet a 90-degree elbow with a diameter 
equal to the largest flue collar size of the draft hood, connect a 
5-foot (1.5-meter) length of vent pipe to that elbow, and orient the 
vent pipe to discharge vertically upward. Install direct-vent gas-
fired water heaters 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, connect to the draft hood outlet a 
90-degree elbow with a diameter equal to the largest flue collar 
size of the draft hood, connect to the elbow fitting a length of 
vent pipe sufficient to establish the draft, and orient the vent 
pipe 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 all modes and rate the unit using 
the results of the most energy-intensive mode.
    5.2 Water Heater Preparation.
    5.2.1 Determination of Storage Tank Volume. For water heaters 
with a rated storage volume greater than or equal to 2 gallons, 
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 of 
this appendix) and dividing the resulting net weight by the density 
of water at the measured temperature.
    5.2.2 Setting the Outlet Discharge Temperature.
    5.2.2.1 Flow-Activated Water Heaters, including certain 
instantaneous water heaters and certain storage-type water heaters. 
Initiate normal operation of the water heater at the full input 
rating for electric water heaters and at the maximum firing rate 
specified by the manufacturer for gas or oil water heaters. Monitor 
the discharge water temperature and set to a value of 125 [deg]F 
 5 [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 (6.4 liters 
 0.95 liters per minute), then adjust the flow rate as 
necessary to achieve the specified discharge water temperature. Once 
the proper temperature control setting is achieved, the setting must 
remain fixed for the duration of the

[[Page 40571]]

maximum GPM test and the simulated-use test.
    5.2.2.2 Storage-Type Water Heaters that Are Not Flow-Activated.
    5.2.2.2.1 Tanks with a Single Temperature Controller.
    5.2.2.2.1.1 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[emsp14][deg]F  5[emsp14][deg]F (51.7 [deg]C  2.8 [deg]C). If not, turn off the water heater, adjust the 
temperature controller, 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 125[emsp14][deg]F 
 5[emsp14][deg]F (51.7 [deg]C  2.8 [deg]C). 
Once the proper temperature control setting is achieved, the setting 
must remain fixed for the duration of the first-hour rating test and 
the simulated-use test such that a second identical simulated-use 
test run immediately following the one specified in section 5.4 
would result in average delivered water temperatures that are within 
the bounds specified in section 2.4 of this appendix.
    5.2.2.2.1.2 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[emsp14][deg]F  5[emsp14][deg]F (51.7 [deg]C  2.8 [deg]C). If not, turn off the water heater, adjust the 
temperature controller, 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[emsp14][deg]F 
 5[emsp14][deg]F (51.7 [deg]C  2.8 [deg]C). 
Once the proper temperature control setting is achieved, the setting 
must remain fixed for the duration of the first-hour rating test and 
the simulated-use test such that a second identical simulated-use 
test run immediately following the one specified in section 5.4 
would result in average delivered water temperatures that are within 
the bounds specified in section 2.4 of this appendix.
    5.2.2.2.2 Tanks with Two or More Temperature Controllers. Verify 
the temperature controller set-point while removing water in 
accordance with the procedure set forth for the first-hour rating 
test in section 5.3.3 of this appendix. The following criteria must 
be met to ensure that all temperature controllers are set to deliver 
water at 125[emsp14][deg]F  5[emsp14][deg]F (51.7 [deg]C 
 2.8 [deg]C):
    (a) At least 50 percent of the water drawn during the first draw 
of the first-hour rating test procedure shall be delivered at a 
temperature of 125 [deg]F  5 [deg]F (51.7 [deg]C  2.8 [deg]C).
    (b) No water is delivered above 130 [deg]F (54.4 [deg]C) during 
first-hour rating test.
    (c) The delivery temperature measured 15 seconds after 
commencement of each draw begun prior to an elapsed time of 60 
minutes from the start of the test shall be at 125[emsp14][deg]F 
 5[emsp14][deg]F (51.7 [deg]C  2.8 [deg]C).
    If these conditions are not met, turn off the water heater, 
adjust the temperature controllers, and then drain and refill the 
tank with supply water. Repeat the procedure described at the start 
of section 5.2.2.2.2 until the criteria for setting the temperature 
controllers is met.
    If the conditions stated above are met, the data obtained during 
the process of verifying the temperature control set-points may be 
used in determining the first-hour rating provided that all other 
conditions and methods required in sections 2 and 5.2.4 in preparing 
the water heater were followed.
    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 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. Adjust all 
burners 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 D2156 (incorporated by reference, 
see Sec.  430.3).
    5.2.4 Soak-In Period for Water Heaters with Rated Storage 
Volumes Greater than or Equal to 2 Gallons. For storage-type water 
heaters and instantaneous water heaters having greater than 2 
gallons (7.6 liters) of storage (including heat pump water heaters 
having greater than 2 gallons of storage), the water heater must sit 
filled with water and without any draws taking place for at least 12 
hours after initially being energized so as to achieve the nominal 
temperature set-point within the tank and with the unit connected to 
a power source.
    5.3 Delivery Capacity Tests.
    5.3.1 General. For flow-activated water heaters, conduct the 
maximum GPM test, as described in section 5.3.2, Maximum GPM Rating 
Test for Flow-Activated Water Heaters, of this appendix. For all 
other water heaters, conduct the first-hour rating test as described 
in section 5.3.3 of this appendix.
    5.3.2 Maximum GPM Rating Test for Flow-Activated Water Heaters. 
Establish normal water heater operation at the full input rate for 
electric water heaters and at the maximum firing rate for gas or oil 
water heaters with the discharge water temperature set in accordance 
with section 5.2.2.1 of this appendix.
    For this 10-minute test, either collect the withdrawn water for 
later measurement of the total mass removed or use a water meter to 
directly measure the water volume removed. Initiate water flow 
through the water heater and 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 and record 
the mass of water collected, M10m, in pounds (kilograms), 
or the volume of water, V10m, in gallons (liters).
    5.3.3 First-Hour Rating Test.
    5.3.3.1 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 is suitable for weighing at the 
termination of each draw to determine the total volume of water 
withdrawn. As an alternative to collecting the water, a water meter 
may be used to directly measure the water volume(s) withdrawn.
    5.3.3.2 Draw Initiation Criteria. Begin the first-hour rating 
test by starting 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 temperature controller 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 
temperature controller 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 temperature controller acts to reduce the 
electrical input to the energized 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 temperature controller. For heat 
pump water heaters that use supplemental resistive heating, initiate 
successive draws immediately after the electrical input to the first 
of either the compressor or the vertically highest resistive element 
is reduced by the action of the applicable water heater temperature 
controller. 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[emsp14][deg]F  5[emsp14][deg]F (51.7 
[deg]C  2.8 [deg]C). If this

[[Page 40572]]

criterion is not met, then the next draw should be initiated once 
the heat pump compressor cuts out.
    5.3.3.3 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 temperature controllers are satisfied), record the 
internal storage tank temperature at each sensor described in 
section 4.5 of this appendix every one 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[emsp14][deg]F 
 2[emsp14][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). (Note, if the outlet temperature 
does not decrease to T*max,1 - 15 [deg]F 
(T*max,1 - 8.3 [deg]C) during the draw, then hot water 
would be drawn continuously for the duration of the test. In this 
instance, the test would end when the temperature decreases to 
T*max,1- 15 [deg]F (T*max,1 - 8.3 [deg]C) 
after the electrical power and/or fuel supplied to the water heater 
is shut off, as described in the following paragraphs.) 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(s) each 
time the applicable draw initiation criteria described in section 
5.3.3.2 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 after the start of the test, then shut off the electrical power 
and/or fuel supplied to the water heater.
    If a draw is occurring at one hour from the start of the test, 
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 measurements associated with the final 
draw.) If a draw is not occurring one hour after the start of the 
test, initiate a final draw at one hour, regardless of whether the 
criteria described in section 5.3.3.2 of this appendix are 
satisfied. This draw shall proceed for a minimum of 30 seconds and 
shall terminate 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 of initiation 
of the draw, 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 final draw (T*del,n and M*n or 
V*n, respectively).
    5.4 24-Hour Simulated Use Test.
    5.4.1 Selection of Draw Pattern. The water heater will be tested 
under a draw profile that depends upon the first-hour rating 
obtained following the test prescribed in section 5.3.3 of this 
appendix, or the maximum GPM rating obtained following the test 
prescribed in section 5.3.2 of this appendix, whichever is 
applicable. For water heaters that have been tested according to the 
first-hour rating procedure, one of four different patterns shall be 
applied based on the measured first-hour rating, as shown in Table I 
of this section. For water heater that have been tested according to 
the maximum GPM rating procedure, one of four different patterns 
shall be applied based on the maximum GPM, as shown in Table II of 
this section.

                           Table I--Draw Pattern To Be Used Based on First-Hour Rating
----------------------------------------------------------------------------------------------------------------
  First-hour rating greater than or     ... and first-hour
              equal to:                  rating less than:       Draw pattern to be used in simulated-use test
----------------------------------------------------------------------------------------------------------------
0 gallons...........................  18 gallons............  Very-Small-Usage (Table III.1).
18 gallons..........................  51 gallons............  Low-Usage (Table III.2).
51 gallons..........................  75 gallons............  Medium-Usage (Table III.3).
75 gallons..........................  No upper limit........  High-Usage (Table III.4).
----------------------------------------------------------------------------------------------------------------

                          Table II--Draw Pattern To Be Used Based on Maximum GPM Rating
----------------------------------------------------------------------------------------------------------------
 Maximum GPM rating greater than or   and maximum GPM rating
              equal to:                     less than:           Draw pattern to be used in simulated-use test
----------------------------------------------------------------------------------------------------------------
0 gallons/minute....................  1.7 gallons/minute....  Very-Small-Usage (Table III.1).
1.7 gallons/minute..................  2.8 gallons/minute....  Low-Usage (Table III.2).
2.8 gallons/minute..................  4 gallons/minute......  Medium-Usage (Table III.3).
4 gallons/minute....................  No upper limit........  High-Usage (Table III.4).
----------------------------------------------------------------------------------------------------------------

    The draw patterns are provided in Tables III.1 through III.4 in 
section 5.5 of this appendix. Use the appropriate draw pattern when 
conducting the test sequence provided in section 5.4.2 of this 
appendix for water heaters with rated storage volumes greater than 
or equal to 2 gallons or section 5.4.3 of this appendix for water 
heaters with rated storage volumes less than 2 gallons.
    5.4.2 Test Sequence for Water Heaters with Rated Storage Volumes 
Greater Than or Equal to 2 Gallons. If the water heater is turned 
off, fill the water heater with supply water and maintain supply 
water pressure as described in section 2.6 of this appendix. Turn on 
the water heater and associated heat pump unit, if present. If 
turned on in this fashion, the soak-in period described in section 
5.2.4 of this appendix shall be implemented. If the water heater has 
undergone a first-hour rating test prior to conduct of the 
simulated-use test, allow the water heater to fully recover after 
completion of that test such that the main burner, heating elements, 
or heat pump compressor of the water heater are no longer raising 
the temperature of the stored water. In all cases, the water heater 
shall sit idle for 1 hour prior to the start of the 24-hour test; 
during which time no water is drawn from the unit and there is no 
energy input to the main heating elements, heat pump compressor, 
and/or burners. At the end of this period, the 24-hour simulated-use 
test will begin.
    At the start of the 24-hour test, 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 40573]]

in the appropriate table in section 5.5 of this appendix (i.e., 
Table III.1, Table III.2, Table III.3, or Table III.4, depending on 
the first-hour rating or maximum GPM rating) for the first draw at 
the flow rate specified in the applicable table. 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 5.5 of this appendix for a particular draw 
pattern, initiate additional draws pursuant to the draw pattern, 
removing the volume of hot water at the prescribed flow rate 
specified by the table. The maximum allowable deviation from the 
specified volume of water removed for any single draw taken at a 
nominal flow rate of 1 GPM or 1.7 GPM is 0.1 gallons 
(0.4 liters). The maximum allowable deviation from the 
specified volume of water removed for any single draw taken at a 
nominal flow rate of 3 GPM is 0.25 gallons (0.9 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). If this 
adjustment to the volume drawn during the last draw results in no 
draw taking place, the test is considered invalid.
    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 5.5 of this appendix, within a tolerance of 0.25 
gallons per minute (0. 9 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. Calculate and record 
the mean of the hot water discharge temperature and the cold water 
inlet temperature 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 
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.
    The start of the portion of the test during which the standby 
loss coefficient is determined depends upon whether the unit has 
fully recovered from the first draw cluster. If a recovery is 
occurring at or within five minutes of the end of the final draw in 
the first draw cluster, as identified in the applicable draw pattern 
table in section 5.5 of this appendix, then the standby period 
starts when a maximum average tank temperature is observed starting 
five minutes after the end of the recovery period that follows that 
draw. If a recovery does not occur at or within five minutes of the 
end of the final draw in the first draw cluster, as identified in 
the applicable draw pattern table in section 5.5 of this appendix, 
then the standby period starts five minutes after the end of that 
draw. Determine and record the total electrical energy and/or fossil 
fuel consumed from the beginning of the test to the start of the 
standby period, 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 mean tank temperature at the 
start of the standby period as Tsu,0. 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 
start of the standby period 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.
    In the event that the recovery period continues from the end of 
the last draw of the first draw cluster until the subsequent draw, 
the standby period will start after the end of the first recovery 
period after the last draw of the simulated-use test, when the 
temperature reaches the maximum average tank temperature, though no 
sooner than five minutes after the end of this recovery period. The 
standby period shall last eight hours, so testing will extend beyond 
the 24-hour duration of the simulated-use test. Determine and record 
the total electrical energy and/or fossil fuel consumed from the 
beginning of the simulated-use test to the start of the 8-hour 
standby period, Qsu,0. In preparation for determining the 
energy consumed during standby, record the reading(s) given on the 
electrical energy (watt-hour) meter, the gas meter, and/or the scale 
used to determine oil consumption, as appropriate. Record the mean 
tank temperature at the start of the standby period as 
Tsu,0. Record the mean tank temperature, the ambient 
temperature, and the electric and/or fuel instrument readings until 
the end of the 8 hour period. Record the mean tank temperature at 
the end of the 8 hour standby period as Tsu,f. If the 
water heater is undergoing recovery at the end of the standby 
period, record the mean tank temperature Tsu,f at the 
minute prior to the start of the recovery, which will mark the end 
of the standby period. Determine the total electrical energy and/or 
fossil fuel energy consumption from the beginning of the test to the 
end of the standby period and record this value as Qsu,f. 
Record the time interval between the start of the standby period and 
the end of the standby period as [tau]stby,1.
    Following the final draw of the prescribed draw pattern and 
subsequent recovery, allow the water heater to remain in the standby 
mode until exactly 24 hours have elapsed since the start of the 
simulated-use test (i.e., since [tau] = 0). During the last hour of 
the simulated-use test, power to the main burner, heating element, 
or compressor shall be disabled. At 24 hours, record the reading 
given by the gas meter, oil 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.
    5.4.3 Test Sequence for Water Heaters With Rated Storage Volume 
Less Than 2 Gallons.
    Establish normal operation with the discharge water temperature 
at 125 [deg]F  5 [deg]F (51.7 [deg]C  2.8 
[deg]C) and set the flow rate as determined in section 5.2 of this 
appendix. 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 Tables 
III.1 through III.4 of section 5.5 of this appendix 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 Tables 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 Tables 
III.1 through III.4. The maximum allowable deviation from the 
specified volume of water removed for any single draw taken at a 
nominal flow rate less than or equal to 1.7 GPM (6.4 L/min) is 
0.1 gallons (0.4 liters). The maximum 
allowable deviation from the specified volume of water removed for 
any single draw taken at a nominal flow rate of 3 GPM (11.4 L/min) 
is 0.25 gallons (0.9 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). If this adjustment to the volume drawn in 
the last draw results in no draw taking place, the test is 
considered invalid.
    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. Calculate 
the mean of the hot water discharge temperature and the cold water 
inlet temperature for each draw. Record 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 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, oil meter, and/or the electrical energy meter, as 
appropriate. Determine the fossil fuel and/or electrical energy 
consumed during the entire

[[Page 40574]]

24-hour simulated-use test and designate the quantity as Q.
    5.5 Draw Patterns. The draw patterns to be imposed during 24-
hour simulated-use tests are provided in Tables III.1 through III.4. 
Subject each water heater under test to one of these draw patterns 
based on its first-hour rating or maximum GPM rating, as discussed 
in section 5.4.1 of this appendix. 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--Very-Small-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                       Time during test    Volume  [gallons   Flow Rate **  [GPM
                      Draw No.                              [hh:mm]              (L)]              (L/min)]
----------------------------------------------------------------------------------------------------------------
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 maximum GPM rating less than 1 GPM (3.8 L/min), then all draws shall be
  implemented at a flow rate equal to the rated maximum GPM.

                                       Table III.2--Low-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                       Time during test    Volume  [gallons   Flow rate  [GPM (L/
                      Draw No.                              [hh:mm]            (liters)]             min)]
----------------------------------------------------------------------------------------------------------------
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 test    Volume  [gallons   Flow rate  [GPM (L/
                      Draw No.                              [hh:mm]            (liters)]             min)]
----------------------------------------------------------------------------------------------------------------
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 40575]]

                                      Table III.4--High-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                       Time during test    Volume  [gallons   Flow rate  [GPM (L/
                      Draw No.                              [hh:mm]            (liters)]             min)]
----------------------------------------------------------------------------------------------------------------
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 First-Hour Rating Computation. For the case in which the 
final draw is initiated at or prior to one hour from the start of 
the test, the first-hour rating, Fhr, shall be computed 
using,
[GRAPHIC] [TIFF OMITTED] TR11JY14.067

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] TR11JY14.068

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 one hour from 
the start of the test and a final draw is imposed at the elapsed 
time of one hour, the first-hour rating shall be calculated using
[GRAPHIC] [TIFF OMITTED] TR11JY14.069

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).
    6.2 Maximum GPM (L/min) Rating Computation. Compute the maximum 
GPM (L/min) rating, Fmax, as:

[[Page 40576]]

[GRAPHIC] [TIFF OMITTED] TR11JY14.070

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] TR11JY14.071

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.

    6.3 Computations for Water Heaters with a Rated Storage Volume 
Greater Than or Equal to 2 Gallons.
    6.3.1 Storage Tank Capacity. The storage tank capacity, 
Vst, is computed as follows:
[GRAPHIC] [TIFF OMITTED] TR11JY14.072

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)

    6.3.2 Recovery Efficiency. The recovery efficiency for gas, oil, 
and heat pump storage-type water heaters, [eta]r, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TR11JY14.073

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).
Tin,1 = average water inlet temperature measured during 
the draws from the start

[[Page 40577]]

of the 24-hour simulated-use test to the end of the first recovery 
period, [deg]F ([deg]C).
Vst = as defined in section 6.3.1.
[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 percent.
    6.3.3 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,o

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 starting five 
minutes 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] TR11JY14.075
    
Where:

Qhr = the hourly standby energy losses of the water 
heater, Btu/h (kJ/h).
Vst = as defined in section 6.3.1 of this appendix.
[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 
starting five minutes after the first recovery following the final 
draw of the first draw cluster, [deg]F ([deg]C).
[eta]r = as defined in section 6.3.2 of this appendix.
[tau]stby,1 = elapsed time between the time at which the 
maximum mean tank temperature is observed starting five minutes 
after recovery from 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] TR11JY14.076
    
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 
starting five minutes 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 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).
Ta,stby,1 = overall average ambient temperature between 
the time when the maximum mean tank temperature is observed starting 
five minutes 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 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).
    6.3.4 Daily Water Heating Energy Consumption. The daily water 
heating energy consumption, Qd, is computed as:
[GRAPHIC] [TIFF OMITTED] TR11JY14.077

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 6.3.1 of this appendix.
[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 6.3.2 of this appendix.

    6.3.5 Adjusted Daily Water Heating Energy Consumption. The 
adjusted daily water heating energy consumption, Qda, 
takes into account that the ambient temperature may differ from the 
nominal value of 67.5[emsp14][deg]F (19.7[deg]C) due to the 
allowable variation in surrounding ambient temperature of 
65[emsp14][deg]F (18.3 [deg]C) to 70 [deg]C (21.1[deg]C). The 
adjusted daily water heating energy consumption is computed as:

[[Page 40578]]

[GRAPHIC] [TIFF OMITTED] TR11JY14.078

Where:

Qda = the adjusted daily water heating energy 
consumption, Btu (kJ).
Qd = as defined in section 6.3.4 of this appendix.
Ta,stby,2 = the average ambient temperature during the 
total standby portion, [tau]stby,2, of the 24-hour 
simulated-use test, [deg]F ([deg]C).
UA = as defined in section 6.3.3 of this appendix.
[tau]stby,2 = the number of hours during the 24-hour 
simulated-use 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[emsp14][deg]F (125[emsp14][deg]F-58[emsp14][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] TR11JY14.079

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 6.3.2 of this appendix.

    The energy required to heat the same quantity of water over a 
67[emsp14][deg]F (37.3 [deg]C) temperature rise, Btu/day (kJ/day), 
is:
[GRAPHIC] [TIFF OMITTED] TR11JY14.080

    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 ambient 
temperature may not be 67.5 [deg]F (19.7 [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

    6.3.6 Uniform Energy Factor. The uniform energy factor, UEF, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TR11JY14.082

Where:

N = total number of draws in the draw pattern
Qdm = the modified daily water heating energy consumption 
as computed in accordance with section 6.3.5 of this appendix, 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[emsp14][deg]F + 58[emsp14][deg]F)/2 =

[[Page 40579]]

91.5[emsp14][deg]F ((51.7[emsp14][deg]C + 14.4[emsp14][deg]C)/2 = 33 
[deg]C), Btu/(lb[middot] [deg]F) (kJ/(kg[middot] [deg]C)).

    6.3.7 Annual Energy Consumption. The annual energy consumption 
for water heaters with rated storage volumes greater than or equal 
to 2 gallons is computed as:
[GRAPHIC] [TIFF OMITTED] TR11JY14.083

Where:

UEF = the uniform energy factor as computed in accordance with 
section 6.3.6 of this appendix
365 = the number of days in a year
V = the volume of hot water drawn during the applicable draw 
pattern, gallons
= 10 for the very-small-usage 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[emsp14][deg]F
CP = 1.00 Btu/lbm[emsp14][deg]F, the specific 
heat of water at 91.5[emsp14][deg]F
67 = the nominal temperature difference between inlet and outlet 
water

    6.3.8 Annual Electrical Energy Consumption. The annual 
electrical energy consumption in kilowatt-hours for water heaters 
with rated storage volumes greater than or equal to 2 gallons, 
Eannual,e, is computed as:

Eannual,e = Eannual*(Qe/Q)/3412

Where:

Eannual = the annual energy consumption as determined in 
accordance with section 6.3.7, Btu (kJ)
Qe = the daily electrical energy consumption as defined 
in section 6.3.4 of this appendix, Btu (kJ).
Q = total energy used by the water heater during the 24-hour 
simulated-use test in accordance with section 6.3.4 of this 
appendix, Btu (kJ)
3412 = conversion factor from Btu to kWh

    6.3.9 Annual Fossil Fuel Energy Consumption. The annual fossil 
fuel energy consumption for water heaters with rated storage volumes 
greater than or equal to 2 gallons, Eannual,f, is 
computed as:

Eannual,f = Eannual - (Eannual,e x 
3412)

Where:

Eannual = the annual energy consumption as determined in 
accordance with section 6.3.7 of this appendix, Btu (kJ)
Eannual,e = the annual electrical energy consumption as 
determined in accordance with section 6.3.8 of this appendix, kWh
3412 = conversion factor from kWh to Btu
    6.4 Computations for Water Heaters With Rated Storage Volume 
Less Than 2 Gallons.
    6.4.1 Recovery Efficiency. The recovery efficiency, [eta]r, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TR11JY14.084

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 [mnplus] 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.)
    6.4.2 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 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] TR11JY14.085
    
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 6.4.1 of this appendix.

    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] TR11JY14.086

[[Page 40580]]

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 6.4.1 of this appendix.

    The difference between these two values is:

    [GRAPHIC] [TIFF OMITTED] TR11JY14.095
    

This difference (QHWD) must be added to the daily water 
heating energy consumption value. Thus, the daily energy consumption 
value, which takes into account that the temperature rise across the 
water heater may not be 67 [deg]F (37.3 [deg]C), is:

Qdm = Qd + QHWD

    6.4.3 Uniform Energy Factor. The uniform energy factor, UEF, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TR11JY14.087

Where:

N = total number of draws in the draw pattern
Qdm = the modified daily water heating energy consumption 
as computed in accordance with section 6.4.2 of this appendix, 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 = 33.1 [deg]C), Btu/(lb [middot] [deg]F) (kJ/(kg 
[middot] [deg]C)).
    6.4.4 Annual Energy Consumption. The annual energy consumption 
for water heaters with rated storage volumes less than 2 gallons, 
Eannual, is computed as:
[GRAPHIC] [TIFF OMITTED] TR11JY14.088

Where:

UEF = the uniform energy factor as computed in accordance with 
section 6.4.3 of this appendix
365 = the number of days in a year.
V = the volume of hot water drawn during the applicable draw 
pattern, gallons
= 10 for the very-small-usage 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[emsp14][deg]F
CP = 1.00 Btu/lbm [deg]F, the specific heat of 
water at 91.5[emsp14][deg]F
67 = the nominal temperature difference between inlet and outlet 
water

    6.4.5 Annual Electrical Energy Consumption. The annual 
electrical energy consumption in kilowatt-hours for water heaters 
with rated storage volumes less than 2 gallons, 
Eannual, e, is computed as:

Eannual,e = Eannual*(Qe/Q)/3412

Where:

Qe = the daily electrical energy consumption as defined 
in section 6.4.2 of this appendix, Btu (kJ)
Eannual = the annual energy consumption as determined in 
accordance with section 6.4.4 of this appendix, Btu (kJ)
Q = total energy used by the water heater during the 24-hour 
simulated-use test in accordance with section 6.4.2 of this 
appendix, Btu (kJ)
Qdm = the modified daily water heating energy consumption 
as computed in accordance with section 6.4.2 of this appendix, Btu 
(kJ)
3412 = conversion factor from Btu to kWh

    6.4.6 Annual Fossil Fuel Energy Consumption. The annual fossil 
fuel energy consumption for water heaters with rated storage volumes 
less than 2 gallons, Eannual,f, is computed as:

Eannual,f = Eannual-(Eannual,e x 
3412)

Where:

Eannual,e = the annual electrical energy consumption as 
defined in section 6.4.5 of this appendix, kWh.
Eannual = the annual energy consumption as defined in 
section 6.4.4 of this appendix, Btu (kJ)
3412 = conversion factor from kWh to Btu

[[Page 40581]]

[GRAPHIC] [TIFF OMITTED] TR11JY14.089

[GRAPHIC] [TIFF OMITTED] TR11JY14.090

[[Page 40582]]

[GRAPHIC] [TIFF OMITTED] TR11JY14.091

[[Page 40583]]

[GRAPHIC] [TIFF OMITTED] TR11JY14.092

[[Page 40584]]

[GRAPHIC] [TIFF OMITTED] TR11JY14.093

[[Page 40585]]

[GRAPHIC] [TIFF OMITTED] TR11JY14.094

0
11. 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 =20 gallons and =20 gallons and h.
* * * * *

PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND 
INDUSTRIAL EQUIPMENT

0
12. The authority citation for part 431 continues to read as follows:

    Authority: 42 U.S.C. 6291-6317.

0
13. Section 431.102 is amended by adding the definition of 
``Residential-duty 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.

* * * * *
    Residential-duty 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 designed to provide outlet hot water at temperatures 
greater than 180[emsp14][deg]F; and
    (3) Does not meet any of the following criteria:

------------------------------------------------------------------------
                                           Indicator of non-residential
           Water heater type                       application
------------------------------------------------------------------------
Gas-fired Storage......................  Rated input >105 kBtu/h; Rated
                                          storage volume >120 gallons.
Oil-fired Storage......................  Rated input >140 kBtu/h; Rated
                                          storage volume >120 gallons.
Electric Storage.......................  Rated input >12 kW; Rated
                                          storage volume >120 gallons.
Heat Pump with Storage.................  Rated input >12 kW; Rated
                                          current >24 A at a rated
                                          voltage of not greater than
                                          250 V; Rated storage volume
                                          >120 gallons.
Gas-fired Instantaneous................  Rated input >200 kBtu/h; Rated
                                          storage volume >2 gallons.
Electric Instantaneous.................  Rated input >58.6 kW; Rated
                                          storage volume >2 gallons.
Oil-fired Instantaneous................  Rated input >210 kBtu/h; Rated
                                          storage volume >2 gallons.
------------------------------------------------------------------------

* * * * *

0
14. 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) * * *

                          Table 2 to Sec.   431.106--Test Procedures for Commercial Water Heaters and Hot Water Supply Boilers
                                                     [Other Than Commercial Heat Pump Water Heaters]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Test procedure required for      With these additional
          Equipment type              Energy efficiency descriptor        Test procedure          compliance on and after             stipulations
--------------------------------------------------------------------------------------------------------------------------------------------------------
Residential-Duty Commercial Water   Uniform Energy Factor...........  10 CFR Part 430,       December 31, 2015***............  None.
 Heater.                                                               Subpart B, Appendix
                                                                       E.

[[Page 40587]]

 
Gas-fired Storage and               Thermal Efficiency..............  Use test set-up,       May 13, 2013....................  A. For all products, the
 Instantaneous Water Heaters and                                       equipment, and                                           duration of the standby
 Hot Water Supply Boilers*.                                            procedures in                                            loss test shall be until
                                                                       subsection labeled                                       whichever of the
                                                                       ``Method of Test''                                       following occurs first
                                                                       of ANSI Z21.10.3-                                        after you begin to
                                                                       2011**, Exhibit G1.                                      measure the fuel and/or
                                                                                                                                electric consumption:
                                                                                                                                (1) The first cut-out
                                                                                                                                after 24 hours or (2) 48
                                                                                                                                hours, if the water
                                                                                                                                heater is not in the
                                                                                                                                heating mode at that
                                                                                                                                time.
                                    Standby Loss....................  Use test set-up,       May 13, 2013....................  B. For oil and gas
                                                                       equipment, and                                           products, the standby
                                                                       procedures in                                            loss in Btu per hour
                                                                       subsection labeled                                       must be calculated as
                                                                       ``Method of Test''                                       follows: SL (Btu per
                                                                       of ANSI Z21.10.3-                                        hour) = S (% per hour) x
                                                                       2011**, Exhibit G2.                                      8.25 (Btu/gal-F) x
                                                                                                                                Measured Volume (gal) x
                                                                                                                                70 (degrees F).
Oil-fired Storage and               Thermal Efficiency..............  ANSI Z21.10.3-2011**,  May 13, 2013....................  C. For oil-fired
 Instantaneous Water Heaters and    Standby Loss....................   Exhibit G1.           May 13, 2013....................   products, apply the
 Hot Water Supply Boilers*.                                           Use test set-up,                                          following in conducting
                                                                       equipment, and                                           the thermal efficiency
                                                                       procedures in                                            and standby loss tests:
                                                                       subsection labeled                                       (1) Venting
                                                                       ``Method of Test''                                       Requirements--Connect a
                                                                       of ANSI Z21.10.3-                                        vertical length of flue
                                                                       2011**, Exhibit G2.                                      pipe to the flue gas
                                                                                                                                outlet of sufficient
                                                                                                                                height so as to meet the
                                                                                                                                minimum draft specified
                                                                                                                                by the manufacturer. (2)
                                                                                                                                Oil Supply--Adjust the
                                                                                                                                burner rate so that: (a)
                                                                                                                                The hourly Btu input
                                                                                                                                rate lies within 2 percent of the
                                                                                                                                manufacturer's specified
                                                                                                                                input rate, (b) the CO2
                                                                                                                                reading shows the value
                                                                                                                                specified by the
                                                                                                                                manufacturer, (c) smoke
                                                                                                                                in the flue does not
                                                                                                                                exceed No. 1 smoke as
                                                                                                                                measured by the
                                                                                                                                procedure in ASTM-D2156-
                                                                                                                                80 (reference for
                                                                                                                                guidance only, see Sec.
                                                                                                                                 431.104), and (d) fuel
                                                                                                                                pump pressure lies
                                                                                                                                within 10
                                                                                                                                percent of
                                                                                                                                manufacturer's
                                                                                                                                specifications.
Electric Storage and Instantaneous  Standby Loss....................  Use test set-up,       May 13, 2013....................  D. For electric products,
 Water Heaters.                                                        equipment, and                                           apply the following in
                                                                       procedures in                                            conducting the standby
                                                                       subsection labeled                                       loss test: (1) Assume
                                                                       ``Method of Test''                                       that the thermal
                                                                       of ANSI Z21.10.3-                                        efficiency (Et) of
                                                                       2011**, Exhibit G2.                                      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.
*** Because the statute permits use of a conversion factor until the later of December 31, 2015 or one year after publication of a conversion factor
  final rule, DOE may amend the mandatory compliance date for use of this amended test procedure, as necessary.

0
15. 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 40588]]

                Table 1 to Sec.   431.107--Test Procedures for Commercial Heat Pump Water Heaters
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                                                                    Use test set-up,
                                                                     equipment, and      Test procedure required
            Equipment type                Energy efficiency          procedures in        for compliance on and
                                              descriptor           subsection labeled             after
                                                                 ``Method of Test'' of
----------------------------------------------------------------------------------------------------------------
Residential-Duty Heat Pump Water       Uniform Energy Factor..  10 CFR Part 430,         December 31, 2015*.
 Heater with Integrated Storage Tank.                            Subpart B, Appendix E.
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All Other Types......................  [Reserved].............  [Reserved].............  [Reserved].
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* Because the statute permits use of a conversion factor until the later of December 31, 2015 or one year after
  publication of a conversion factor final rule, DOE may amend the mandatory compliance date for use of this
  amended test procedure, as necessary.

[FR Doc. 2014-15656 Filed 7-10-14; 8:45 a.m.]
BILLING CODE 6450-01-P
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