Vol. 78 Monday, 

No. 213 November 4, 2013 

Part IV 

Department of Energy 

10 CFR Parts 429, 430 and 431 

Energy Conservation Program for Consumer Products and Certain 

Commercial and Industrial Equipment: Test Procedures for Residential and 

Commercial Water Heaters; Proposed Rule 


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66202 Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 

DEPARTMENT OF ENERGY 

10 CFR Parts 429, 430 and 431 

[Docket Number EERE–2011–BT–TP–0042] 

RIN 1904–AC53 

Energy Conservation Program for 

Consumer Products and Certain 

Commercial and Industrial Equipment: 

Test Procedures for Residential and 

Commercial Water Heaters 

AGENCY: Office of Energy Efficiency and 

Renewable Energy, Department of 

Energy. 

ACTION: Notice of proposed rulemaking 

and announcement of public meeting. 

SUMMARY: The U.S. Department of 

Energy (DOE) proposes to revise its test 

procedure for residential water heaters 

and certain commercial water heaters 

established under the Energy Policy and 

Conservation Act. This rulemaking will 

fulfill DOE’s statutory obligation for 

residential and certain commercial 

water heaters to review its test 

procedure for covered products and 

equipment at least once every seven 

years. In addition, this rulemaking will 

satisfy DOE’s statutory obligation to 

develop a uniform efficiency descriptor 

for residential and commercial water 

heaters. The proposed test method 

would apply the same efficiency 

descriptor to all residential and certain 

commercial water heaters, and it would 

extend coverage to eliminate certain 

gaps in the current residential test 

procedure, update the simulated-usetest draw pattern, and update the water 

delivery temperature requirement. DOE 

is also announcing a public meeting to 

discuss and receive comments on issues 

presented in this test procedure 

rulemaking. 

DATES:

Comments: DOE will accept 

comments, data, and information 

regarding this notice of proposed 

rulemaking (NOPR) before and after the 

public meeting, but no later than 

January 21, 2014. See section V, ‘‘Public 

Participation,’’ for details. 

Meeting: DOE will hold a public 

meeting on December 6, 2013 from 9:00 

a.m. to 4:00 p.m., in Washington, DC. 

The meeting will also be broadcast as a 

webinar. See section V, ‘‘Public 

Participation,’’ for webinar registration 

information, participant instructions, 

and information about the capabilities 

available to webinar participants. 

ADDRESSES: The public meeting will be 

held at the U.S. Department of Energy, 

Forrestal Building, Room 8E–089, 1000 

Independence Avenue SW., 

Washington, DC 20585. To attend, 

please notify Ms. Brenda Edwards at 

(202) 586–2945. Please note that foreign 

nationals visiting DOE Headquarters are 

subject to advance security screening 

procedures. Any foreign national 

wishing to participate in the meeting 

should advise DOE as soon as possible 

by contacting Ms. Edwards at the phone 

number above to initiate the necessary 

procedures. Please also note that any 

person wishing to bring a laptop 

computer into the Forrestal Building 

will be required to obtain a property 

pass. Visitors should avoid bringing 

laptops, or allow an extra 45 minutes. 

Persons may also attend the public 

meeting via webinar. For more 

information, refer to section V, ‘‘Public 

Participation,’’ near the end of this 

notice of proposed rulemaking. 

Interested persons are encouraged to 

submit comments using the Federal 

eRulemaking Portal at 

www.regulations.gov. Follow the 

instructions for submitting comments. 

Alternatively, interested persons may 

submit comments, identified by docket 

number EERE–2011–BT–TP–0042 and/

or RIN 1904–AC53, by any of the 

following methods: 

• Email: HeatingProducts-2011-TP0042@ee.doe.gov. Include EERE–2011– 

BT–TP–0042 and/or RIN 1904–AC53 in 

the subject line of the message. Submit 

electronic comments in WordPerfect, 

Microsoft Word, PDF, or ASCII file 

format, and avoid the use of special 

characters or any form of encryption. 

• Postal Mail: Ms. Brenda Edwards, 

U.S. Department of Energy, Building 

Technologies Office, Mailstop EE–2J, 

1000 Independence Avenue SW., 

Washington, DC 20585–0121. If 

possible, please submit all items on a 

compact disc (CD), in which case it is 

not necessary to include printed copies. 

• Hand Delivery/Courier: Ms. Brenda 

Edwards, U.S. Department of Energy, 

Building Technologies Office, 950 

L’Enfant Plaza SW., 6th Floor, 

Washington, DC 20024. Telephone: 

(202) 586–2945. If possible, please 

submit all items on a CD, in which case 

it is not necessary to include printed 

copies. 

Instructions: All submissions received 

must include the agency name and 

docket number and/or RIN for this 

rulemaking. No telefacsimilies (faxes) 

will be accepted. For detailed 

instructions on submitting comments 

and additional information on the 

rulemaking process, see section V of this 

document (Public Participation). 

Docket: The docket is available for 

review at including Federal Register 

notices, public meeting attendee lists 

and transcripts, comments, and other 

supporting documents/materials. All 

documents in the docket are listed in 

the index. However, not all documents 

listed in the index may be publicly 

available, such as information that is 

exempt from public disclosure. 

A link to the docket Web page can be 

found at: http://www.regulations.gov/

#!docketDetail;D=EERE-2011-BT-TP0042. This Web page contains a link to 

the docket for this notice of proposed 

rulemaking on the site. The Web page 

contains simple instructions on how to 

access all documents, including public 

comments, in the docket. See section V, 

‘‘Public Participation,’’ for information 

on how to submit comments through 

www.regulations.gov. 

For information on how to submit a 

comment, review other public 

comments and the docket, or participate 

in the public meeting, contact Ms. 

Brenda Edwards at (202) 586–2945 or by 

email: Brenda.Edwards@ee.doe.gov. 

FOR FURTHER INFORMATION CONTACT: Ms. 

Ashley Armstrong, U.S. Department of 

Energy, Office of Energy Efficiency and 

Renewable Energy, Building 

Technologies Office, EE–2J, 1000 

Independence Avenue SW., 

Washington, DC 20585–0121. 

Telephone: (202) 586–6590. Email: 

Ashley.Armstrong@ee.doe.gov. 

Mr. Eric Stas, U.S. Department of 

Energy, Office of the General Counsel, 

GC–71, 1000 Independence Avenue 

SW., Washington, DC 20585–0121. 

Telephone: (202) 586–9507. Email: 

Eric.Stas@hq.doe.gov. 

For information on how to submit or 

review public comments, contact Ms. 

Brenda Edwards, U.S. Department of 

Energy, Office of Energy Efficiency and 

Renewable Energy, Building 

Technologies Office, EE–2J, 1000 

Independence Avenue SW., 

Washington, DC 20585–0121. 

Telephone: (202) 586–2945. Email: 

Brenda.Edwards@ee.doe.gov. 

SUPPLEMENTARY INFORMATION: 

Table of Contents 

I. Authority and Background 

II. Summary of the Notice of Proposed 

Rulemaking 

III. Discussion 

A. Scope 

1. Coverage Range of Uniform Metric and 

Test Procedure 

2. Storage Capacity Limits 

3. Input Capacity Limits 

4. Electric Instantaneous Water Heaters 

B. Uniform Efficiency Descriptor 

C. Draw Pattern 

D. Instrumentation 

E. Discrete Performance Tests 

F. Test Conditions 

1. Water Delivery Temperature 

2. Ambient Temperature and Relative 

Humidity 

3. Laboratory Airflow 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 66203 

1For editorial reasons, upon codification in the 

U.S. Code, Part B was redesignated as Part A. 

2All 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). 

3For editorial reasons, upon codification in the 

U.S. Code, Part C was redesignated Part A–1. 

4On May 16, 2012, DOE published a final rule in 

the Federal Register amending the test procedures 

for commercial water heaters. 77 FR 28928. 

G. Annual Energy Consumption 

Calculation 

H. Conversion of Existing Energy Factor 

Ratings 

I. Other Issues 

J. Certification, Compliance, and 

Enforcement Issues 

K. Reference Standards 

L. Compliance With Other EPCA 

Requirements 

IV. Procedural Issues and Regulatory Review 

A. Review Under Executive Order 12866 

B. Review Under the Regulatory Flexibility 

Act 

C. Review Under the Paperwork Reduction 

Act of 1995 

D. Review Under the National 

Environmental Policy Act of 1969 

E. Review Under Executive Order 13132 

F. Review Under Executive Order 12988 

G. Review Under the Unfunded Mandates 

Reform Act of 1995 

H. Review Under the Treasury and General 

Government Appropriations Act, 1999 

I. Review Under Executive Order 12630 

J. Review Under Treasury and General 

Government Appropriations Act, 2001 

K. Review Under Executive Order 13211 

L. Review Under Section 32 of the Federal 

Energy Administration Act of 1974 

V. Public Participation 

A. Attendance at the Public Meeting 

B. Procedure for Submitting Requests to 

Speak and Prepared General Statements 

for Distribution 

C. Conduct of the Public Meeting 

D. Submission of Comments 

E. Issues on Which DOE Seeks Comment 

VI. Approval of the Office of the Secretary 

I. Authority and Background 

Title III, Part B1 of the Energy Policy 

and Conservation Act of 1975 (‘‘EPCA’’ 

or ‘‘the Act’’), Public Law 94–163 (42 

U.S.C. 6291–6309, as codified) sets forth 

a variety of provisions designed to 

improve energy efficiency and 

established the Energy Conservation 

Program for Consumer Products Other 

Than Automobiles.2 These include 

residential water heaters, one subject of 

today’s notice of proposed rulemaking. 

(42 U.S.C. 6292(a)(4)) Title III, Part C 3

of EPCA, Public Law 94–163 (42 U.S.C. 

6311–6317, as codified), added by 

Public Law 95–619, Title IV, Sec. 441(a), 

established the Energy Conservation 

Program for Certain Industrial 

Equipment, which includes the 

commercial water-heating equipment 

that is another subject of this 

rulemaking. (42 U.S.C. 6311(1)(K)) 

Under EPCA, energy conservation 

programs generally consist of four parts: 

(1) Testing; (2) labeling; (3) establishing 

Federal energy conservation standards; 

and (4) certification and enforcement 

procedures. The testing requirements 

consist of test procedures that 

manufacturers of covered products and 

equipment must use as both the basis 

for certifying to DOE that their products 

and equipment comply with the 

applicable energy conservation 

standards adopted pursuant to EPCA, 

and for making other representations 

about the efficiency of those products. 

(42 U.S.C. 6293(c); 42 U.S.C. 6295(s); 42 

U.S.C. 6314) Similarly, DOE must use 

these test requirements to determine 

whether the products comply with any 

relevant standards promulgated under 

EPCA. (42 U.S.C. 6295(s)) 

Under 42 U.S.C. 6293, EPCA sets forth 

the criteria and procedures that DOE 

must follow when prescribing or 

amending test procedures for residential 

water heaters. EPCA provides, in 

relevant part, that any test procedures 

prescribed or amended under this 

section must be reasonably designed to 

produce test results which measure 

energy efficiency, energy use, or 

estimated annual operating cost of a 

covered product during a representative 

average use cycle or period of use, and 

must not be unduly burdensome to 

conduct. (42 U.S.C. 6293(b)(3)) In 

addition, if DOE determines that a test 

procedure amendment is warranted, it 

must publish proposed test procedures 

and offer the public an opportunity to 

present oral and written comments on 

them. (42 U.S.C. 6293(b)(2)) 

For commercial water heaters, EPCA 

requires that if the test procedure 

referenced in the American Society of 

Heating, Refrigerating, and AirConditioning Engineers (ASHRAE) 

Standard 90.1 is updated, DOE must 

update its test procedure to be 

consistent with the amended test 

procedure in ASHRAE Standard 90.1, 

‘‘Energy Standard for Buildings Except 

Low-Rise Residential Buildings,’’ unless 

DOE determines by rule published in 

the Federal Register and supported by 

clear and convincing evidence, that the 

amended test procedure is not 

reasonably designed to produce test 

results which reflect the energy 

efficiency, energy use, or estimated 

operating costs of that type of ASHRAE 

equipment during a representative 

average use cycle. In addition, DOE 

must determine that the amended test 

procedure is not unduly burdensome to 

conduct. (42 U.S.C. 6314(a)(2) and (4)) 

In any rulemaking to amend a test 

procedure, DOE must determine the 

extent to which the proposed test 

procedure would alter the product’s 

measured energy efficiency. (42 U.S.C. 

6293(e)(1)) If DOE determines that the 

amended test procedure would alter the 

measured efficiency of a covered 

product, DOE must amend the 

applicable energy conservation standard 

accordingly. (42 U.S.C. 6293(e)(2)) 

Further, the Energy Independence and 

Security Act of 2007 (EISA 2007) 

amended EPCA to require that at least 

once every 7 years, DOE must review 

test procedures for all covered products 

and either amend test procedures (if the 

Secretary determines that amended test 

procedures would more accurately or 

fully comply with the requirements of 

42 U.S.C. 6293(b)(3) for residential 

products or 42 U.S.C. 6314(a)(2)-(3) for 

commercial equipment) or publish 

notice in the Federal Register of any 

determination not to amend a test 

procedure. (42 U.S.C. 6293(b)(1)(A); 42 

U.S.C. 6314(a)(1)(A)) Under this 

requirement, DOE must review the test 

procedures for residential water heaters 

not later than December 19, 2014 (i.e., 

7 years after the enactment of EISA 

2007), and DOE must review the test 

procedures for commercial water 

heaters not later than May 16, 2019 (i.e., 

7 years after the last final rule for 

commercial water heater test 

procedures 4). Thus, the final rule 

resulting from this rulemaking will 

satisfy the requirement to review the 

test procedures for residential and 

certain commercial water heaters every 

seven years. 

DOE’s test procedure for residential 

water heaters is found in the Code of 

Federal Regulations (CFR) at 10 CFR 

430.23(e) and 10 CFR part 430, subpart 

B, appendix E. The test procedure 

includes provisions for determining the 

energy efficiency (energy factor (EF)), as 

well as the annual energy consumption 

of these products. DOE’s test procedure 

for commercial water heaters is found at 

10 CFR 431.106; that test procedure 

incorporates by reference American 

National Standards Institute (ANSI) 

Z21.10.3, Gas Water Heaters—Volume 

III, Storage Water Heaters With Input 

Ratings Above 75,000 Btu Per Hour, 

Circulating and Instantaneous, and 

provides a method for determining the 

thermal efficiency and standby loss of 

this equipment. 

In addition to the test procedure 

review provision discussed above, EISA 

2007 also amended EPCA to require 

DOE to amend its test procedures for all 

covered residential products to include 

measurement of standby mode and off 

mode energy consumption. (42 U.S.C. 

6295(gg)(2)(A)) Consequently, DOE 

recently completed a rulemaking to 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
66204 Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 

5For more information, please visit DOE’s Web 

site at: http://www1.eere.energy.gov/buildings/

appliance_standards/residential/waterheaters.html. 

consider amending its test procedure for 

residential water heaters to include 

provisions for measuring the standby 

mode and off mode energy consumption 

of those products. Pursuant to the 

requirements of EPCA, DOE published a 

notice of proposed rulemaking (NOPR) 

in the Federal Register on August 30, 

2010, for three different residential 

heating products (water heaters, pool 

heaters, and direct heating equipment) 

related to standby mode and off mode 

energy consumption, but the NOPR 

proposed no amendments to the DOE 

test procedure for residential water 

heaters because DOE tentatively 

concluded that standby mode and off 

mode energy consumption was already 

accounted for in the existing DOE test 

method.5 75 FR 52892, 52895. 

Subsequently, DOE published a final 

rule in the Federal Register on 

December 17, 2012, which affirmed its 

conclusion that no changes were needed 

to the existing test procedure for 

residential water heaters. 77 FR 74559, 

74561–74562. However, that rulemaking 

was limited to consideration of test 

procedure amendments to address the 

above-referenced standby mode and off 

mode requirements; it did not address 

several other potential issues in DOE’s 

existing test procedure for residential 

water heaters. DOE addresses these 

issues in today’s NOPR. 

On October 12, 2011, DOE published 

in the Federal Register a request for 

information (RFI) that identified and 

requested comment on a number of 

issues regarding the test procedures for 

residential water heaters. 76 FR 63211. 

DOE accepted comments and 

information on the RFI until November 

28, 2011, and considered all feedback 

received when developing the proposals 

contained in this notice. Each of the 

issues raised in the RFI is discussed in 

detail in section III, along with 

comments received on the issues and 

DOE’s responses. In addition, several 

topics not addressed in the RFI but 

brought up by interested parties in their 

comments are discussed in section III of 

this NOPR. 

On December 18, 2012, the American 

Energy Manufacturing Technical 

Corrections Act (AEMTCA), Public Law 

112–210, was signed into law. In 

relevant part, it amended EPCA to 

require that DOE publish a final rule 

establishing a uniform efficiency 

descriptor and accompanying test 

methods for covered residential water 

heaters and commercial water heating 

equipment within one year of the 

enactment of AEMTCA. (42 U.S.C. 

6295(e)(5)(B)) The final rule must 

replace the current energy factor, 

thermal efficiency, and standby loss 

metrics with a uniform efficiency 

descriptor. (42 U.S.C. 6295(e)(5)(C)) 

AEMTCA requires that, beginning one 

year after the date of publication of 

DOE’s final rule establishing the 

uniform descriptor, the efficiency 

standards for covered water heaters 

must be denominated according to the 

uniform efficiency descriptor 

established in the final rule (42 U.S.C. 

6295(e)(5)(D)), and that DOE must 

develop a mathematical conversion 

factor for converting the measurement of 

efficiency for covered water heaters 

from the test procedures and metrics 

currently in effect to the new uniform 

energy descriptor. (42 U.S.C. 

6295(e)(5)(E)(i)–(ii)) After the effective 

date of the final rule, covered water 

heaters shall be considered to comply 

with the final rule and with any revised 

labeling requirements established by the 

Federal Trade Commission (FTC) to 

carry out the final rule, if the covered 

water heater was manufactured prior to 

the effective date of the final rule and 

complies with the efficiency standards 

and labeling requirements in effect prior 

to the final rule. (42 U.S.C. 

6295(e)(5)(K)) 

AEMTCA also requires that the 

uniform efficiency descriptor and 

accompanying test method apply, to the 

maximum extent practicable, to all 

water-heating technologies currently in 

use and to future water-heating 

technologies. (42 U.S.C. 6295(e)(5)(H)) 

AEMTCA allows DOE to provide an 

exclusion from the uniform efficiency 

descriptor for specific categories of 

otherwise covered water heaters that do 

not have residential uses, that can be 

clearly described, and that are 

effectively rated using the current 

thermal efficiency and standby loss 

descriptors. (42 U.S.C. 6295(e)(5)(F)) 

AEMTCA outlines DOE’s various 

options for establishing a new uniform 

efficiency descriptor for water heaters. 

The options that AEMTCA provides to 

DOE include: (1) A revised version of 

the energy factor descriptor currently in 

use; (2) the thermal efficiency and 

standby loss descriptors currently in 

use; (3) a revised version of the thermal 

efficiency and standby loss descriptors; 

(4) a hybrid of descriptors; or (5) a new 

approach. (42 U.S.C. 6295(e)(5)(G)) 

Lastly, AEMTCA requires that DOE 

invite stakeholders to participate in the 

rulemaking process, and that DOE 

contract with the National Institute of 

Standards and Technology (NIST), as 

necessary, to conduct testing and 

simulation of alternative descriptors 

identified for consideration. (42 U.S.C. 

6295(e)(5)(I)–(J)) 

DOE published an RFI on January 11, 

2013 requesting input on the various 

issues pertaining to water heaters 

discussed in AEMTCA. 78 FR 2340. The 

feedback received from stakeholders 

was taken into consideration and is 

discussed further in section III of this 

NOPR. 

II. Summary of the Notice of Proposed 

Rulemaking 

In this NOPR, DOE proposes to 

modify the current test procedures for 

residential water heaters and certain 

commercial water heaters. The proposed 

amendments would modify the test 

procedure to be more representative of 

conditions encountered in the field 

(including modifications to both the test 

conditions and the draw patterns) and 

expand the scope of the test procedure 

to apply to certain commercial water 

heaters and certain residential water 

heaters that are currently not covered by 

the test procedure. The following 

paragraphs summarize these proposed 

changes. 

DOE proposes to modify the test 

procedure for water heaters to establish 

a uniform descriptor that can be applied 

to: (1) All residential water heaters 

(including certain residential water 

heaters that are covered products under 

EPCA’s definition of ‘‘water heater’’ at 

42 U.S.C. 6291(27), but that are not 

covered under the existing test method); 

and (2) to certain commercial water 

heaters that have residential 

applications. This includes the 

proposed establishment of test 

procedure provisions that are applicable 

to water heaters with storage volumes 

between 2 gallons (7.6 L) and 20 gallons 

(76 L), and the proposed creation of a 

definition for ‘‘electric instantaneous 

water heater.’’ In addition, DOE 

proposes to establish a new equipment 

class of commercial water heaters and 

corresponding definition for ‘‘light 

commercial water heater.’’ DOE 

proposes to require water heaters that 

would be classified as ‘‘light 

commercial’’ to be tested using the test 

procedure for the uniform efficiency 

descriptor being proposed in this NOPR. 

DOE is also proposing the use of 

multiple draw patterns for testing water 

heaters, with certain draw patterns 

prescribed as a function of equipment 

capacity. Further, DOE proposes 

updates to the water heater draw pattern 

to be more reflective of actual field 

usage based on recent field test data. 

Lastly, DOE is modifying the water 

delivery temperature requirement to 

better reflect conditions as seen in 

typical installations in the field. 


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6ACEEE submitted a joint comment on behalf of 

ACEEE, the Appliance Standards Awareness Project 

(ASAP), the National Consumer Law Center 

(NCLC), the Natural Resources Defense Council 

(NRDC), the Northeast Energy Efficiency 

Partnerships (NEEP), and the Northwest Power and 

Conservation Council (NPCC). 

7As provided by 42 U.S.C. 6295(e)(5)(F), DOE is 

proposing to allow for the exclusion from the 

uniform efficiency descriptor of certain commercial 

water heaters that do not have a residential use and 

can be clearly described in the final rule and are 

effectively rated using the thermal efficiency and 

standby loss descriptors. The water heaters that 

DOE is proposing to exclude are discussed further 

in section III.A.1. 

8All references to comments received in response 

to the October 2011 and January 2013 RFI’s identify 

the commenter, the identification number applied 

by DOE, and the page of the comment package on 

which the particular point has been discussed. 

III. Discussion 

In response to the October 2011 RFI, 

DOE received 19 written comments 

related to water heaters from the 

following interested parties: Pacific Gas 

and Electric Company (PGE), Applied 

Energy Technology (AET), Davis Energy 

Group, American Council for an EnergyEfficient Economy (ACEEE), Southern 

California Edison (SCE), National 

Renewable Energy Laboratory (NREL), 

Natural Resources Canada (NRCan), 

Natural Resources Defense Council 

(NRDC), Air-Conditioning, Heating, and 

Refrigeration Institute (AHRI), 

Northwest Energy Efficiency Alliance 

(NEEA), American Gas Association 

(AGA), National Propane Gas 

Association (NPGA), A.O. Smith 

Corporation (AO Smith), Bradford 

White Corporation (Bradford White), 

Lochinvar, Stone Mountain 

Technologies, Bosch Thermotechnology 

Corp. (Bosch), General Electric 

Company (GE), and ASHRAE. 

In response to the January 2013 RFI, 

DOE received 18 written comments 

from the following interested parties: 

NREL, Bradford White, AGA, NPGA, 

AHRI, AO Smith, joint efficiency 

advocates (joint comment),6 GE, NEEA, 

Rheem Manufacturing Company 

(Rheem), American Public Gas 

Association (APGA), Edison Electric 

Institute (EEI), Heat Transfer Products 

Inc. (HTP), Natural Resources Canada 

(NRCan), Seisco International Limited 

(Seisco), Aquarensics, and two separate 

comments from the University of 

Houston—Clear Lake (UHCL1, UHCL2). 

These interested parties commented 

on a range of issues, including those 

identified by DOE in the October 2011 

RFI and the January 2013 RFI, as well 

as several other pertinent issues. The 

issues on which DOE received 

comment, as well as DOE’s response to 

those comments and the resulting 

proposed changes to the test procedures 

for water heaters, are discussed in the 

subsections immediately below. 

A. Scope 

DOE’s test procedures for residential 

water heaters codified at 10 CFR 

430.23(e) and 10 CFR part 430, subpart 

B, appendix E address gas-fired, electric, 

and oil-fired storage-type (i.e., storage 

volume not less than 20 gallons (76 L)) 

and gas-fired and electric instantaneoustype (i.e., storage volume less than 2 

gallons (7.6 L)) water heaters. However, 

the DOE test procedure does not define 

‘‘electric instantaneous water heater.’’ In 

addition, it does not address the 

following types of products: (1) Gasfired water heaters that have a storage 

volume at or above 2 gallons and less 

than 20 gallons (76 L); (2) electric 

storage water heaters with storage 

volume less than 20 gallons (76 L); and 

(3) storage water heaters with very large 

storage capacities, including oil-fired 

water heaters with storage volumes 

greater than 50 gallons (190 L), gas-fired 

water heaters with storage volumes 

above 100 gallons (380 L), and electric 

water heaters with storage volumes 

above 120 gallons (450 L). As discussed 

in the following sections, DOE proposes 

to expand the scope of coverage of its 

test method so that it is applicable to all 

products that meet the definition of 

residential water heater, including those 

products listed above which are 

currently not addressed by the existing 

DOE test method. DOE is also revising 

10 CFR 430.32(d) to clarify the 

applicability of the existing standards 

with respect to the expanded test 

procedure scope. 

DOE’s test procedures for commercial 

water heaters are found at 10 CFR 

431.106. In terms of capacity, the 

procedures for commercial water 

heaters cover storage water heaters with 

an input rating up to 4,000 British 

thermal units (Btu) per hour (Btu/h) per 

gallon of stored water, instantaneous 

water heaters with input ratings not less 

than 4,000 Btu/h per gallon of stored 

water, and hot water supply boilers with 

input ratings from 300,000 Btu/h to 

12,500,000 Btu/h and of at least 4,000 

Btu/h per gallon of stored water. Units 

using natural gas, oil, or electricity are 

covered by these test methods. 

EPCA includes definitions for both 

residential and commercial water 

heaters that set the scope of DOE’s 

authority for these products. (42 U.S.C. 

6291(27); 42 U.S.C. 6311(12)) As 

required by AEMTCA, DOE proposes to 

create a uniform metric and test method 

for all covered water heaters,7 regardless 

of whether a particular water heater falls 

under the scope of residential water 

heaters or commercial water heaters as 

defined in EPCA. In doing so, DOE also 

proposes to expand the scope of the test 

procedure to include definitions and 

test methods for the types of products 

noted above that are not covered by 

DOE’s residential test procedure. DOE 

identified these topics as issues for 

comment in the October 2011 RFI and 

the January 2013 RFI. 76 FR 63211, 

63212–63213 (Oct. 12, 2011); 78 FR 

2340, 2344–2346 (Jan. 11, 2013). 

1. Coverage Range of Uniform Metric 

and Test Procedure 

In the January 2013 RFI, DOE 

requested comment on whether the 

uniform efficiency descriptor required 

by AEMTCA should apply to all types 

of residential and commercial water 

heaters covered by EPCA, in addition to 

hot water supply boilers and unfired hot 

water storage tanks. In requesting 

comment, DOE acknowledged that 

AEMTCA provides for the possibility of 

an exclusion for certain water heaters 

from the uniform efficiency metric and 

accompanying test method. 78 FR 2340, 

2345–46 (Jan. 11, 2013). 

DOE received 7 comments that 

opposed DOE’s tentative interpretation 

that AEMTCA requires the uniform 

descriptor to apply to all types of 

residential and commercial water 

heaters and indicated that DOE should 

utilize the statutory provision 

permitting an exclusion for any specific 

category of otherwise covered water 

heaters that do not have a residential 

use. (Bradford White, No. 30 at p. 2; 

AHRI, No. 33 at p. 1; AO Smith, No. 34 

at p. 1; Joint comment, No. 35 at p. 2; 

NEEA, No. 37 at p. 2; Rheem, No. 38 at 

p. 2; HTP, No. 41 at p. 1) 8 Bradford 

White recommended that the uniform 

efficiency descriptor be limited to water 

heaters with inputs less than 200,000 

Btu/h, which would cover those water 

heaters intended for residential 

applications. (Bradford White, No. 30 at 

p. 2) AHRI, AO Smith, Rheem, and HTP 

indicated that the legislation was 

intended to apply to residential 

products only and that development of 

a uniform metric and test method for all 

water heaters is not realistic given the 

substantially different duty cycles 

between water heaters meant for 

commercial applications and those 

meant for residential applications. 

(AHRI, No. 33 at pp. 1–2; AO Smith, No. 

34 at p. 1; Rheem, No. 38 at p. 2; HTP, 

No. 41 at p. 1) The joint commenters 

supported a realignment of the scope 

that includes all water heaters except 

those clearly designed to deliver large 

amounts of hot water. (Joint comment, 

No. 35 at p. 2) NEEA recommended that 

DOE should focus on water heaters 


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meant for residential and small 

commercial applications. (NEEA, No. 37 

at p. 2) No commenters supported 

DOE’s tentative interpretation that 

AEMTCA requires the uniform 

descriptor to apply to all types of 

residential and commercial water 

heaters. 

After considering the comments 

received, DOE proposes to exclude from 

the uniform efficiency descriptor any 

specific category of water heater that 

does not have a residential use. As 

noted above, AEMTCA provides that 

DOE can exclude from the uniform 

descriptor any specific categories of 

covered water heaters that do not have 

a residential use, can be clearly 

described in the final rule, and are 

effectively rated using the current 

thermal efficiency and standby loss 

descriptors. (42 U.S.C. 6295(e)(5)(F)) 

DOE received 13 comments regarding 

how to define water heaters that do not 

have a residential application. In light of 

these comments, DOE proposes to 

define a new classification of 

commercial water heaters for which the 

uniform efficiency descriptor would 

apply (i.e., ‘‘light commercial water 

heaters’’), which DOE believes can be 

clearly distinguished from the 

commercial water heaters for which the 

uniform descriptor would not apply 

under this proposal. DOE believes that 

the current metrics for commercial 

water heaters that are used only in 

commercial settings are appropriate and 

adequate to characterize the 

performance of such commercial water 

heaters. Commercial water heaters 

typically cycle less than residential 

water heaters due to longer run-times 

followed by standby periods. 

(Residential water heaters are typically 

subject to a number of small draws and 

short on-times throughout the day.) As 

a result, cycling losses of water heaters 

used in commercial applications are 

generally not as significant as those 

used in residential applications. Thus, 

DOE believes that thermal efficiency 

and standby loss metrics adequately 

characterize the efficiency in active and 

standby modes, respectively. 

AHRI, AO Smith, and HTP suggested 

that the following characteristics may be 

suitable to distinguish water heaters 

intended for non-residential use: (1) 

Designed to deliver water at a 

thermostatically controlled temperature 

of 180 °F or more; (2) bear a Code 

Symbol Stamp signifying compliance 

with the requirements of the American 

Society of Mechanical Engineers 

(ASME) Boiler and Pressure Vessel 

Code; and (3) require electricity as the 

primary energy source and require the 

use of 3-phase external supply. (AHRI, 

No. 33 at p. 2; AO Smith, No. 34 at p. 

1; HTP, No. 41 at p. 2) The joint 

commenters likewise stated that water 

heaters utilizing 3-phase electric power, 

designed to deliver water above 180 °F, 

and falling under the guise of the ASME 

pressure vessel code are not typical of 

residential applications. (Joint 

comment, No. 35 at p. 2) NEEA 

commented that there are many water 

heaters with features that make them 

unsuitable for residential and small 

commercial applications and provided 

examples of units with set points of 

180 °F or higher, 3-phase power, and 

large input ratings and volumes. (NEEA, 

No. 37 at p. 2) AHRI, AO Smith, Rheem, 

and HTP also provided tables of rated 

inputs and storage volumes to 

distinguish water heaters that are not 

intended for residential applications. 

(AHRI, No. 33 at p. 2; AO Smith, No. 34 

at p. 1; Rheem, No. 38 at p. 2; HTP, No. 

41 at p. 2) Those limits are grouped by 

water heater type and are shown in 

Table III.1. 

TABLE III.1—SUGGESTED CAPACITY LIMITATIONS FOR DEFINING NON-RESIDENTIAL WATER HEATERS

Water heater type Indicator of non-residential application by commenter 

Gas-fired storage ................................................ AHRI, Rheem: Rated input >100 kBtu/h; Rated storage volume <20 gallons and >100 gallons. 

AO Smith: Rated Input > 100kBtu/h; Rated storage volume >100 gallons. 

HTP: Rated input >150 kBtu/h; Rated storage volume <20 gallons and >120 gallons. 

Oil-fired storage .................................................. AHRI, AO Smith, Rheem: Rated input >140 kBtu/h; Rated storage volume >50 gallons. 

Electric storage ................................................... AHRI, Rheem, HTP: Rated input >12 kW; Rated storage volume <20 gallons and >120 gallons. 

AO Smith: Rated Input >12 kW; Rated storage volume >120 gallons. 

Heat Pump with Storage .................................... AHRI, AO Smith, Rheem, HTP: Rated current >24 Amperes; Rated voltage >250 V; Rated 

storage volume >120 gallons. 

Gas-fired instantaneous ...................................... AHRI, AO Smith, Rheem, HTP: Rated input >200 kBtu/h; Water volume >1 gallon per 4000 

Btu/h of input. 

Electric instantaneous ......................................... AHRI, Rheem: Rated input >12 kW; Water volume >2 gallons. 

AO Smith: Rated input >25 kW; Water volume >2 gallons. 

Oil-fired instantaneous ........................................ AHRI, Rheem, AO Smith: Rated input >210 kBtu/h; Water volume >2 gallons. 

Bradford White recommended that 

the new descriptor be limited to water 

heaters with inputs less than 200,000 

Btu/h because, according to the 

commenter, water heaters with inputs 

greater than or equal to 200,000 Btu/hr 

are not used in residential applications 

since such a high input is not required 

in these types of applications. (Bradford 

White, No. 30 at p. 2) AGA stated that 

efficiency descriptors and test methods 

are best developed through consensusbased processes and referred DOE to the 

scope that is currently present in 

ASHRAE Standard 118.2, Method of 

Testing for Rating Residential Water 

Heaters. (AGA, No. 31 at 2) 

Upon considering these comments, 

DOE agrees with commenters that a unit 

requiring three-phase electricity would 

nearly always be used only in a 

commercial setting, as residential homes 

are wired almost exclusively for singlephase power. Likewise, DOE agrees with 

commenters that units with an ASME 

pressure vessel rating or units capable of 

delivering water at temperatures at or 

exceeding 180 °F would generally only 

be used in commercial settings. As a 

result, DOE proposes to use these three 

criteria as the basis for defining ‘‘light 

commercial’’ water heaters that have 

residential applications. 

DOE also considered the input and 

storage capacity criteria proposed by 

stakeholders to differentiate commercial 

water heaters that would only be used 

in non-residential applications from 

commercial water heaters that could 

have residential applications. DOE notes 

that equipment that was once classified 

as residential based on input capacity or 

storage volume might now be installed 

in a commercial setting and vice versa. 

Given that such changes occur over time 

as new technologies develop, DOE is 

declining to propose criteria in this 

NOPR on an input capacity basis. 

Instead, DOE believes that the three 

criteria discussed in the preceding 


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paragraph are adequate to define the 

class of commercial water heaters that 

could have residential applications. 

Consequently, DOE proposes to add 

the following definition of ‘‘light 

commercial water heater’’ to 10 CFR 

431.102: 

Light commercial water heater means 

any gas-fired, electric, or oil storage or 

instantaneous commercial water heater 

that meets the following conditions: 

(1) For models requiring electricity, 

uses single-phase external power 

supply; 

(2) Is not capable of delivering hot 

water at temperatures of 180 °F or 

above; and 

(3) Does not bear a Code Symbol 

Stamp signifying compliance with the 

requirements of the ASME Boiler and 

Pressure Vessel Code. 

Although light commercial water 

heaters could have residential 

applications, DOE notes that the new 

‘‘light commercial water heater’’ 

definition represents a type of water 

heater that, to a significant extent, is 

distributed in commerce for industrial 

or commercial use. These water heaters 

were and continue to be covered 

industrial equipment, and, if these 

proposals are finalized, will continue to 

be subject to the regulations in part 431 

and the certification requirements for 

commercial and industrial equipment in 

part 429. Similarly, although DOE 

recognizes that some consumer water 

heaters may be installed in a 

commercial setting, those waters heaters 

are covered consumer products for the 

purposes of DOE regulations, the 

regulations in part 430 continue to 

apply, and they must be certified as 

consumer products under part 429. 

If a commercial water heater does not 

meet all of these three conditions, it 

would be classified as a commercial 

water heater that would not be expected 

to be used in residential applications 

and would be subject to the current test 

methods prescribed in 10 CFR 431.106, 

which reference ANSI Z21.10.3. If a 

commercial water heater meets all three 

criteria, DOE proposes to consider it a 

‘‘light commercial water heater,’’ which 

would be subject to the uniform 

efficiency descriptor and test method 

proposed in today’s NOPR. Accordingly, 

DOE proposes to add a row to Table 1 

of 10 CFR 431.106 specifying 10 CFR 

part 430, subpart B, Appendix E as the 

test method for this class of equipment. 

DOE seeks comment on both the 

proposed definition of ‘‘light 

commercial water heater’’ and the 

proposal to subject this equipment to 

the test methods at Appendix E. This is 

identified as issue 1 in section V.E, 

‘‘Issues on Which DOE Seeks 

Comment.’’ 

DOE also received comments 

recommending that certain types of 

water heaters should be excluded from 

the uniform descriptor for various 

reasons. NREL commented that storage 

tanks do not make a complete water 

heating system, so an energy factor is 

not appropriate. NREL elaborated that a 

rating using a standby loss coefficient 

could be appropriate. (NREL, No. 29 at 

pp. 3–4) AHRI, AO Smith, and HTP 

recommended that DOE exclude from 

the descriptor: (1) Unfired storage tanks 

because they do not actually heat water; 

(2) add-on heat pumps because DOE has 

previously determined that these are not 

covered products and they are not 

complete water heaters; and (3) hot 

water supply boilers because, by 

definition, they have inputs exceeding 

the values listed in the commenters’ 

recommendations and because these 

products are all subject to the 

requirements of the ASME Boiler and 

Pressure Vessel Code (AHRI, No. 33 at 

pp. 4–5; AO Smith, No. 34 at p. 3; HTP, 

No. 41 at p. 5) Rheem expressed support 

for AHRI’s list of exclusions. (Rheem, 

No. 38 at p. 2) NEEA recommended that 

DOE should exclude water storage tanks 

from the uniform descriptor because 

they are technically not water heaters 

and they simply store water heated 

elsewhere. NEEA also commented that 

unfired storage tanks should not be 

excused from all efficiency 

requirements since standby loss 

efficiency is important for all hot water 

storage vessels, regardless of where and 

how the water is heated. (NEEA, No. 37 

at p. 2) Conversely, the joint 

commenters recommended that the 

uniform efficiency descriptor should be 

able to effectively measure the 

efficiency of electric heat pump water 

heaters without an integrated storage 

tank in the event it is included in future 

Federal coverage. (Joint comment, No. 

35 at p. 5) 

DOE has tentatively determined that 

certain commercial equipment such as 

unfired storage tanks and add-on heat 

pump water heaters are not 

appropriately rated using the uniform 

descriptor applicable to other water 

heaters. Unfired storage tanks are not 

complete water-heating systems and 

require additional equipment in the 

field to operate. Thus, DOE believes that 

other metrics may be more appropriate 

for these devices with limited 

functionality compared to actual water 

heaters, and that their performance as 

part of a complete water-heating system 

is so dependent upon other components 

of the system that use of the uniform 

descriptor may be unrepresentative of 

its performance as a system. For add-on 

heat pump water heaters, DOE agrees 

with stakeholders that DOE has 

previously determined that these are not 

covered residential products. As such, 

DOE only has authority to cover 

commercial add-on heat pumps; 

however, this equipment does not have 

residential applications, and, therefore, 

is not suitable for inclusion in the 

uniform efficiency descriptor. DOE has 

also tentatively determined that hot 

water supply boilers are more 

appropriately rated using the existing 

metrics for commercial water heaters, as 

this equipment has very high input 

ratings and are subject to the ASME 

Boiler and Pressure Vessel Code, and 

their use is similar to that of other 

commercial water heaters in commercial 

applications. DOE will address the types 

of water-heating equipment that are 

excluded from the uniform descriptor 

(e.g., unfired storage tanks, add-on heat 

pump water heaters, and hot water 

supply boilers) in a subsequent test 

procedure rulemaking. 

2. Storage Capacity Limits 

Under the existing regulatory 

definitions, DOE’s current residential 

water heater test procedures are not 

applicable to gas or electric water 

heaters with storage tanks that are at or 

above 2 gallons (7.6 L) and less than 20 

gallons (76 L). In terms of the high end 

of the capacity range, the current DOE 

test procedure for residential water 

heaters only applies to gas-fired water 

heaters with storage volumes less than 

or equal to 100 gallons (380 L), electric 

resistance and heat pump storage water 

heaters with storage volumes less than 

or equal to 120 gallons (450 L), and oilfired water heaters with storage volumes 

less than or equal to 50 gallons (190 L). 

10 CFR part 430, subpart B, appendix E, 

sections 1.12.1, 1.12.2, and 1.12.4. 

In the 1998 rulemaking establishing 

test procedures for residential water 

heaters, DOE proposed to include units 

with storage volumes between 2 and 20 

gallons, but commenters raised concerns 

that the test procedure demand of 64.3 

gallons per day was not appropriate for 

these small units. 63 FR 25996, 26000 

(May 11, 1998). At that time, DOE 

concluded that the data to determine the 

appropriate daily hot water 

consumption did not exist and that 

alternative procedures proposed by 

commenters were not fully evaluated. 

For these reasons, the Department 

tabled consideration of the inclusion of 

these water heaters until a future 

revision of the DOE test procedure. In 

recent years, however, water heaters 

with such capacities have begun to 

populate the market. The definitions in 


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the DOE test procedure (cited above) 

specify that instantaneous-type water 

heaters have a storage volume of less 

than two gallons (7.6 L) and that electric 

or gas storage-type water heaters have a 

storage volume of 20 gallons (76 L) or 

more. The storage capacity of oil water 

heaters in the test method is not 

restricted by a lower limit, with the 

specification stating that an oil-fired 

storage water heater simply has a rated 

capacity less than or equal to 50 gallons 

(190 L). 10 CFR part 430, subpart B, 

appendix E, sections 1.7 and 1.12. The 

definition for ‘‘Storage-type Water 

Heater of More than 2 Gallons (7.6 

Liters) and Less than 20 Gallons (76 

Liters)’’ is currently reserved. Id. at 

section 1.12.5. DOE requested comment 

on the potential to address this gap in 

the October 2011 RFI, and received 

several comments from interested 

parties. 76 FR 63211, 63213 (Oct. 12, 

2011). 

DOE received 11 comments in 

support of the inclusion of water heaters 

with storage volumes between 2 and 20 

gallons. (Bradford White, No. 2 at p. 1; 

PGE, No. 3 at p. 1; SCE, No. 4 at p. 1; 

Stone Mountain Technologies, No. 5 at 

p. 2; AO Smith, No. 8 at p. 1; NEEA, No. 

9 at p. 2; AHRI, No. 12 at p. 1; NREL, 

No. 14 at p. 7; NRDC, No. 20 at p. 1; 

AET, No. 22 at p. 7; ACEEE, No. 24 at 

pp. 3–4). No comments were received 

opposed to this measure. 

AHRI, AO Smith, Bradford White, and 

Lochinvar suggested that a distinct test 

procedure is needed for electric storage 

water heaters with volumes between 2 

and 20 gallons since the current test 

method is not suited for such point-ofuse products and that this test method 

measure only the standby loss of the 

unit. (Bradford White, No. 2 at p. 1; AO 

Smith, No. 8 at p.1; Lochinvar, No. 10 

at p. 1; AHRI, No. 12 at p. 2) Stone 

Mountain Technologies stated further 

that all electric resistance water heaters 

should be subjected to only a standby 

loss test, because differences between 

models is almost solely based on 

standby losses. (Stone Mountain 

Technologies, No. 5 at p. 3) DOE has 

considered these points but has 

tentatively concluded that, for equity 

across water-heating technologies, all 

water heaters should be tested under a 

simulated-use profile as will be 

discussed in section III.C. DOE proposes 

a profile that is appropriate for point-ofuse water heaters, so any concerns that 

the current test method is not suitable 

are addressed by the proposed test 

method. This profile will simulate the 

way that a point-of-use water heater is 

used in the field and will capture any 

operational characteristics that could 

affect its efficiency. DOE also believes 

that a simulated-use test will better 

capture any potential cycling losses or 

inefficiencies in meeting the demands 

imposed on all water heaters. 

After considering the comments 

received, DOE proposes to expand the 

scope of the water heater test procedure 

for the uniform efficiency descriptor to 

include water heaters with storage 

volumes between 2 and 20 gallons. The 

proposed modifications will specify the 

method of test set-up (including 

instrumenting such water heaters), a test 

method to assess the delivery capacity, 

and the draw pattern that would be used 

to determine the energy efficiency of 

such units. The proposed amendments 

for water heaters with storage volumes 

between 2 and 20 gallons are discussed 

in detail in section III.C of today’s notice 

of proposed rulemaking. 

DOE is not aware of any residential 

water heaters available on the market 

with storage volumes above 100 gallons, 

120 gallons, and 50 gallons for gas-fired, 

electric (resistance and heat pump), and 

oil-fired water heaters, respectively, that 

would be covered as residential 

products under EPCA. Due to the lack 

of water heaters with very large storage 

volumes that meet the definition of a 

residential ‘‘water heater,’’ DOE 

tentatively concluded in the October 

2011 RFI that it is unnecessary to 

expand the scope of the test procedure 

to include gas-fired products over 100 

gallons, electric products over 120 

gallons, or oil-fired products over 50 

gallons, and requested comment on this 

tentative conclusion. 76 FR 63211, 

63213 (Oct. 12, 2011). 

Four commenters (Bradford White, 

AO Smith, NEEA, AHRI) supported 

DOE’s position to maintain the existing 

capacity limits for storage water heaters, 

while three commenters (Stone 

Mountain Technologies, NREL, AET) 

recommended that the test method be 

expanded to include all water heaters 

with storage volumes from 0 to 120 

gallons. (Bradford White, No. 2 at p. 1; 

AO Smith, No. 8 at p. 1; NEEA, No. 9 

at p. 2; AHRI, No. 12 at p. 1; Stone 

Mountain Technologies, No. 5 at p. 2; 

NREL, No. 14 at p. 8; AET, No. 22 at pp. 

6–7) AET noted that the pressure vessel 

code from the American Society of 

Mechanical Engineers requires that 

vessels intended to store fluids under 

pressure must individually undergo a 

rigorous test and inspection procedure if 

they have volumes greater than 120 

gallons. AET noted that because these 

test and certification procedures are 

expensive, manufacturers will avoid 

making products intended for 

residential use that require an ASME 

inspection and code stamp. For this 

reason, AET commented that the upper 

limit of 120 gallons would be 

appropriate for all residential water 

heaters. AET further suggests that 

expanding the volume limit to 120 

gallons would prevent manufacturers 

from evading efficiency standards by 

marketing water heaters slightly larger 

than the currently specified limits. 

(AET, No. 22 at pp. 6–7) 

The subsequent passage of AEMTCA 

has necessitated that DOE reconsider 

the scope of all water heater test 

procedures. DOE has considered these 

comments, as well as the provisions of 

AEMTCA, and proposes to expand the 

scope of the test procedure to include 

all covered water heaters that could 

have residential applications and 

remove the limitations on maximum 

storage volume that are currently in the 

residential test procedure for gas-fired, 

electric, and oil storage water heaters. 

The Department’s authority to regulate 

water heaters is limited to those 

explicitly defined as covered products 

by EPCA. EPCA defines the term ‘‘water 

heater’’ as a product which utilizes oil, 

gas, or electricity to heat potable water 

for use outside the heater upon demand. 

(42 U.S.C. 6291(27)) Further, EPCA 

defines storage type units which include 

gas storage water heaters with an input 

of 75,000 Btu per hour or less, oil 

storage water heaters with an input of 

105,000 Btu per hour or less, and 

electric storage water heaters with an 

input of 12 kilowatts or less. EPCA also 

defines instantaneous type units, which 

are water heaters that contain no more 

than one gallon of water per 4,000 Btu 

per hour of input, including gas 

instantaneous water heaters with an 

input of 200,000 Btu per hour or less, 

oil instantaneous water heaters with an 

input of 210,000 Btu per hour or less, 

and electric instantaneous water heaters 

with an input of 12 kilowatts or less. 

Lastly, EPCA defines covered heat 

pump type units, which have a 

maximum current rating of 24 amperes 

at a voltage no greater than 250 volts, 

and which are designed to transfer 

thermal energy from one temperature 

level to a higher temperature level for 

the purpose of heating water, and 

include all ancillary equipment such as 

fans, storage tanks, pumps, or controls 

necessary for the device to perform its 

function. Id. 

For commercial water heating 

equipment, EPCA defines ‘‘storage water 

heater’’ as a water heater that heats and 

stores water within the appliance at a 

thermostatically controlled temperature 

for delivery on demand, and does not 

include units with an input rating of 

4000 Btu per hour or more per gallon of 

stored water. EPCA also defines 

‘‘instantaneous water heater’’ as a water 


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heater that has an input rating of at least 

4000 Btu per hour per gallon of stored 

water. Lastly, EPCA defines the term 

‘‘unfired hot water storage tank’’ as a 

tank used to store water that is heated 

externally. (42 U.S.C. 6311(12)) 

AEMTCA requires that the new metric 

apply to the extent possible to all waterheating technologies used in residential 

applications. (42 U.S.C. 6295(e)(5)(F) 

and (H)) DOE believes that the test 

method proposed in today’s NOPR 

adequately addresses large water heaters 

regardless of storage volume, provided 

that they are used in residential 

applications. As noted previously in 

section III.A.1, DOE proposes to exclude 

units used only in non-residential 

applications, but DOE does not believe 

that storage volume alone would dictate 

whether a unit is residential or 

commercial. As noted by AET, the 

ASME pressure vessel code requires that 

vessels intended to store fluids under 

pressure must undergo a rigorous test 

and inspection procedure if they have 

volumes greater than 120 gallons. Any 

such products would be ASME pressure 

vessel rated, and under the definition of 

‘‘light commercial water heater’’ 

proposed in section III.A.1, would not 

be subject to the uniform efficiency 

descriptor, which would effectively 

limit the maximum storage volume to 

120 gallons for the purposes of using the 

uniform descriptor. For these reasons, 

DOE proposes to eliminate the 

maximum storage volume limitations 

from the residential water heater test 

procedure. 

3. Input Capacity Limits 

DOE’s current residential water heater 

test procedure is not applicable to gasfired instantaneous water heaters with 

input capacities at or below 50,000 Btu/ 

h or at or above 200,000 Btu/h. 10 CFR 

Part 430, subpart B, Appendix E, section 

1.7.2. In addition, the test procedure is 

not applicable to gas-fired storage water 

heaters with input capacities above 

75,000 Btu/h, electric storage water 

heaters with input ratings above 12 kW, 

and oil-fired storage water heaters with 

input ratings above 105,000 Btu/h. 10 

CFR Part 430, subpart B, Appnedix E, 

section 1.12. 

DOE proposes to eliminate the 

minimum limit on the firing rate of 

instantaneous gas water heaters of 

50,000 Btu/h, as AEMTCA requires that 

the new metric apply to the maximum 

extent practical to all water-heating 

technologies intended for residential 

application. (42 U.S.C. 6295(e)(5)(F) and 

(H)) As discussed in section III.C, DOE 

proposes to adopt multiple draw 

patterns that would vary based on the 

delivery capacity of the water heater. 

Because the draw pattern would be 

dependent upon delivery capacity, DOE 

believes that small gas-fired 

instantaneous units could be 

appropriately tested under the proposed 

procedure. Thus, DOE believes there is 

no reason to retain this lower limit on 

gas-fired instantaneous water heater 

delivery capacity. 

Similarly, DOE proposes to remove 

the maximum input ratings for gas-fired, 

electric, and oil-fired storage water 

heaters, and for gas-fired instantaneous 

water heaters from the test procedure. 

DOE believes that the proposed test 

procedure, because it varies based on 

delivery capacity, is applicable to units 

with input capacities above those 

included in the current residential water 

heater test procedure. Although these 

maximum input limitations were based 

upon DOE’s ‘‘water heater’’ definition at 

42 U.S.C. 6291(27), because AEMTCA 

requires that the new metric apply to all 

water-heating technologies except those 

that do not have a residential use, DOE 

believes that such limits are no longer 

controlling or appropriate in terms of 

the scope of the water heaters test 

procedure. As discussed in section 

III.A.1, given the technology shifts that 

occur over time, DOE does not believe 

input capacity limitations to be a 

consistent indicator of whether a 

product has a residential use. 

4. Electric Instantaneous Water Heaters 

DOE’s current test procedures do not 

contain a definition for ‘‘electric 

instantaneous water heater,’’ but rather 

have a space reserved to define that 

term. 10 CFR Part 430, subpart B, 

appendix E, section 1.7.1. EPCA defines 

‘‘electric instantaneous water heater’’ as 

having an input capacity of 12 kilowatts 

(kW) or less. (42 U.S.C. 6291(27)(B)) As 

noted by commenters and discussed in 

section III.A.1, the heating power 

required for electric instantaneous water 

heaters intended for whole-home 

applications is typically much higher 

than the power capability commonly 

found in storage-type electric water 

heaters. Given the emergence of electric 

instantaneous water heaters on the 

market, DOE requested comment in the 

October 2011 RFI on addressing this gap 

in the test procedure by prescribing a 

definition specifically for the term 

‘‘electric instantaneous water heater.’’ 

DOE noted in the RFI that although the 

24-hour simulated use test in DOE’s test 

procedure for instantaneous water 

heaters at 10 CFR Part 430, subpart B, 

appendix E, section 5.2.4 is titled ‘‘24- 

hour Simulated Use Test for Gas 

Instantaneous Water Heaters,’’ the 

method is also applicable for electric 

instantaneous water heaters. DOE 

requested comment on potential 

modifications to the DOE test procedure 

to address electric instantaneous water 

heaters. 

DOE received thirteen comments in 

support of the proposal to amend DOE’s 

water heater test procedure to include 

electric instantaneous water heaters. 

(Bradford White, No. 2 at p. 1; PGE, No. 

3 at p. 1; SCE, No. 4 at p. 1; Stone 

Mountain Technologies, No. 5 at p. 2; 

AO Smith, No. 8 at p. 1; NEEA, No. 9 

at p. 2; Lochinvar, No. 10 at p. 1; AHRI, 

No. 12 at p. 1; NREL, No. 14 at p. 9; 

NRDC, No. 20 at p. 1; Bosch, No. 17 at 

p. 1; AET, No. 22 at pp. 8–9; and 

ACEEE, No. 24 at p. 4.) DOE received no 

comments opposing such an inclusion. 

Bradford White, AO Smith, AHRI, 

NREL, AET, and ACEEE also suggested 

that the test procedure should be 

amended to cover electric instantaneous 

water heaters with heating rates higher 

than 12 kW in order to accommodate 

units that are meant to serve wholehome applications. (Bradford White, No. 

2 at p. 1; AO Smith, No. 8 at p. 1; AHRI, 

No. 12 at p. 2; NREL, No. 14 at p. 9; 

AET, No. 22 at pp. 8–9; ACEEE, No. 24 

at p. 4) AHRI and ACEEE suggested that 

the test procedure for electric 

instantaneous water heaters should be 

made applicable to water heaters with 

inputs up to 25 kW (AHRI, No. 12 at p. 

2; ACEEE, No. 24 at p. 4), while 

Bradford White suggested an input limit 

of 35 kW (Bradford White, No. 2 at p. 

1), and NREL recommended an input 

limit of 50 kW (NREL, No. 14 at p. 9). 

AET commented that the upper limit be 

based on a maximum current of 200 

Amperes, which is the typical 

maximum value allowed in residences 

in the United States. (AET, No. 22 at pp. 

8–9) In response to the January 2013 

RFI, Aquarensics, UHCL1, UHCL2, and 

Seisco commented that the test method 

should cover electric instantaneous 

water heaters with input ratings in 

excess of 12 kW. (Aquarensics, No. 43 

at p.1; UHCL1, No. 44 at p. 1; UHCL2, 

No. 45 at p. 1; Seisco, No. 47 at p. 1) 

Further, Aquarensics, UHCL1, UHCL2, 

and Seisco all commented that 

commercially-available electric 

instantaneous water heaters that are 

designed for residential applications 

have input ratings greater than the 

current limit of 12 kW for residential 

electric water heaters under EPCA. 

(Aquarensics, No. 43 at p. 2; UHCL1, 

No. 44 at p. 1; UHCL2, No. 45 at p. 1; 

Seisco, No. 47 at p. 3) Aquarensics and 

UHCL2 noted residential applications 

that used units with an input rating of 

28 kW. UHCL1 commented that wholehouse instantaneous water heaters 

typically require 25 kW to 35 kW. 


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9 10 CFR Part 430, subpart B, appendix E, section 

5.1.5 currently states, ‘‘During the simulated use 

test, a total of 64. ±3 1.0 gallons (243 ± 2.8 liters) 

shall be removed.’’ DOE contends that the total is 

in error and should instead read ‘‘64.3 ± 1.0 gallons 

(243 ± 2.8 liters).’’ No correction is proposed at this 

time since the quantity will change in the proposed 

test procedure. 

10Healy, WM, Ullah, T, and Roller, J., ‘‘InputOutput Approach to Predicting the Energy 

Efficiency of Residential Water Heaters—Testing of 

Gas Tankless and Electric Storage Water Heaters,’’ 

ASHRAE Transactions 117 (2011). 

11Hoeschele, M.A. and Springer, D.A., ‘‘Field and 

Laboratory Testing of Gas Tankless Water Heater 

Performance,’’ ASHRAE Transactions 114 (2): 453– 

461 (2008). 

12Bohac, D, Schoenbauer, B., Hewett, M., 

Lobenstein, M.S., Butcher, T. ‘‘Actual Savings and 

Performance of Natural Gas Tankless Water 

Heaters,’’ Center for Energy and Environment 

Report for Minnesota Office of Energy Security 

(August 30, 2010). 

Seisco stated that residential electric 

instantaneous water heaters having 

inputs above 30 kW are commonly built 

and have been used for residential 

applications since 1999. Seisco further 

stated that electric instantaneous water 

heaters with input ratings up to 35 kW 

are used for whole-house applications. 

After considering the comments on 

the RFIs, DOE proposes to amend its 

water heaters test procedure to include 

applicable provisions for electric 

instantaneous water heaters, and to 

define the term ‘‘electric instantaneous 

water heater’’ as follows: 

Electric Instantaneous Water Heater 

means a water heater that uses 

electricity as the energy source, initiates 

heating based on sensing water flow, is 

designed to deliver water at a controlled 

temperature of less than 180 °F (82 °C), 

and has a manufacturer’s specified 

storage capacity of less than 2 gallons 

(7.6 liters). The unit may use a fixed or 

variable power input. 

DOE notes that the proposed 

definition would encompass both 

electric instantaneous water heaters that 

are residential (i.e., with an input 

capacity of 12 kW or less) and 

commercial (i.e., with an input capacity 

greater than 12 kW). Because water 

heaters both above and below 12 kW 

have residential applications, both types 

would be covered by the uniform 

efficiency descriptor. Today’s proposed 

rule provides for a maximum flow rate 

test, as well as a test to obtain the energy 

efficiency expressed in terms of Energy 

Factor (EF). These tests are identical to 

those implemented for gas 

instantaneous water heaters. 

B. Uniform Efficiency Descriptor 

AEMTCA provided the following 

options for the uniform efficiency 

descriptor metric: (1) A revised version 

of the energy factor descriptor currently 

in use; (2) the thermal efficiency and 

standby loss descriptors currently in 

use; (3) a revised version of the thermal 

efficiency and standby loss descriptors; 

(4) a hybrid of descriptors; or (5) a new 

approach. (42 U.S.C. 6295(e)(5)(G)) In 

the January 2013 RFI, DOE requested 

comment on the appropriate metric to 

be used as the uniform descriptor. 78 FR 

2340, 2344–45 (Jan. 11, 2013). Eight 

parties provided comments supporting 

the use of the energy factor metric, but 

obtained using a different method of test 

than provided in the current test 

procedure. (NREL, No. 29 at p. 1; 

Bradford White, No. 30 at p. 1; AHRI, 

No. 33 at p. 3; AO Smith, No. 34 at p. 

2; GE, No. 36 at p. 1; NEEA, No. 37 at 

p. 1; Rheem, No. 38 at p. 3; HTP, No. 

41 at p. 3) The joint comment indicated 

that the existing energy factor metric is 

inadequate and indicated support for a 

series of simulated use tests that would 

result in a revised energy factor. (Joint 

comment, No. 35 at p. 1) No comments 

were received that proposed the use of 

thermal efficiency, standby loss factor, 

or any new metrics. 

NREL stated that the thermal 

efficiency and standby loss metrics are 

not suitable as primary metrics for 

residential applications, because they 

do not completely capture performance. 

(NREL, No. 29 at p. 1) AHRI and HTP 

indicated that the energy factor metric 

would enable testing agencies to build 

on prior experience in testing water 

heaters for residential applications, that 

it would result in an easier conversion 

from the current metric to the uniform 

descriptor, and that it can be technology 

neutral. (AHRI, No. 33 at pp. 3–4; HTP, 

No. 41 at p. 3) HTP also suggested a 

voluntary rating for combined waterheating and space-heating appliances 

based on ASHRAE Standard 124, 

Methods of Testing for Rating 

Combination Space-Heating and WaterHeating Appliances. (HTP, No. 41 at p. 

4) AO Smith suggested that the uniform 

descriptor be given a qualifying name to 

distinguish it from the current energy 

factor, providing ‘‘New Energy Factor’’ 

as an example. (AO Smith, No. 34 at p. 

2) GE indicated that an energy factor 

metric would be technology neutral and 

that it would minimize complexity in 

converting from the current metric to 

the uniform descriptor. (GE, No. 36 at 

p. 1) 

NRCan provided a report 

documenting results of testing of two 

commercial water heaters that are 

marketed towards the residential sector 

under the existing residential test 

procedure. (NRCan, No. 42 at p. 1) The 

report did not identify any problems or 

concerns with testing these units under 

the existing test procedure. 

Based on these comments, DOE 

proposes a modified version of the 

existing energy factor metric as the 

uniform descriptor for products covered 

under this test procedure. DOE believes 

that an energy factor that is derived 

from a simulated use test will provide 

a technology-neutral metric for the 

efficiency of water heaters intended for 

residential applications. The simulated 

use test will capture key performance 

aspects such as burner efficiency, 

standby loss, and cycling that affect 

energy efficiency seen by consumers. 

However, DOE will not adopt voluntary 

rating requirements for combination 

appliances at this time, as that is outside 

the scope of today’s test procedure 

NOPR. Further, DOE does not plan to 

change the name, as suggested by A.O. 

Smith. The Department believes that 

because standards and ratings will be 

transitioned to the new metric and the 

old metric will be come obsolete, there 

will be little confusion by maintaining 

the name ‘‘energy factor.’’ 

C. Draw Pattern 

The term ‘‘draw pattern’’ describes 

the number, flow rate, length, and 

timing of hot water removal from the 

water heater during testing. Primary 

decisions in developing draw patterns 

include the total amount of water to be 

removed during the test and the number 

of draws during the test. The total 

amount of water taken in each draw, 

which is a function of the flow rate and 

the length of the draw, must also be 

specified. Finally, the spacing between 

those draws is needed to complete the 

specification of the draw pattern. 

The current residential water heater 

test procedure includes a 24-hour 

simulated-use test for determining 

energy factor. 10 CFR Part 430, subpart 

B, appendix E, sections 5.1.5 and 5.2.4. 

The 24-hour test specifies that 6 draws 

of equal volume be removed from the 

water heater in the first 6 hours of the 

test for a total draw of 64.3 ± 1.0 gallons 

(243.4 ± 3.8 L).9 Following the six 

draws, the water heater sits in an idle 

mode for the remainder of the 24-hour 

test. Id. The draw pattern is the same 

regardless of the type (e.g., gas-fired, 

electric resistance, oil-fired, heat pump, 

storage, instantaneous) and 

characteristics (e.g., storage volume, 

input capacity) of the water heater. 

In the October 2011 RFI, DOE noted 

that recent data 10 11 12 suggest that the 

draw pattern can impact the energy 

factor of a water heater and can 

potentially offer an advantage to one 

type of water heater technology over 

another. 76 FR 63211, 63213 (Oct. 12, 

2011). These studies also suggest that 

the existing draw pattern in the 

simulated use test may not be 


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representative of actual draw patterns to 

which water heaters are subjected in the 

field. Because different water heaters 

will be subjected to different field 

demands (consumer usage patterns) due 

to operational or performance 

differences, DOE proposes to revise the 

draw pattern to be more representative 

of typical usage patterns experienced in 

the field. DOE is also proposing to 

amend its test procedure to provide for 

different draw patterns for different 

water heaters based upon the 

characteristics of each water heater, 

such as the rate of hot water the unit can 

provide, the storage volume, and the 

heating rate (i.e., input rate). In the 

October 2011 RFI, DOE sought comment 

on improvements that could be made to 

DOE’s existing 24-hour simulated use 

test procedure for water heaters. 

Additional comments were sought by 

and provided in response to the January 

2013 RFI. 

DOE received 27 comments that 

addressed these issues. Four 

commenters (AGA, Bosch, General 

Electric, and Rheem) recommended that 

DOE maintain the test procedure as it 

currently stands. AGA argued the 

importance of consistency with 

previous ratings. (AGA, No. 13 at p. 1) 

Bosch commented that the current test 

procedure covers a large quantity of 

applications without trying to estimate 

the usage for any given household. 

(Bosch, No. 17 at p. 2) General Electric 

wrote that the six-draw requirement is 

appropriate for medium-volume water 

heaters. (GE, No. 21 at pp. 1–2) Rheem 

suggested that the added scope of 

covered products called for by AEMTCA 

would best be handled by maintaining 

the existing residential water heater test 

procedure at this time while continuing 

to pursue an amended test method. 

(Rheem, No. 38 at p. 3) Rheem further 

argued that such an incremental 

approach would allow manufacturers to 

continue on a path to meet minimum 

efficiency requirements imposed by 

amended energy conservation 

standards. 

In total, DOE received twenty-three 

comments recommending that the 

Agency move away from the six-draw 

requirement as currently specified in 

the DOE test procedure (although 

certain of these comments were 

multiple submissions from the same 

interested party). (Bradford White, No. 2 

at p. 2; PGE, No. 3 at p. 2; SCE, No. 4 

at p. 2; Stone Mountain Technologies, 

No. 5 at p. 2; AO Smith, No. 8 at p. 2; 

NEEA, No. 9 at p. 2; NPGA, No. 11 at 

pp. 1–2; AHRI, No. 12 at p. 2; NREL, No. 

14 at pp. 1–2; GTI, No. 15 at p. 2; 

NRCan, No. 16 at pp. 1–2; NRDC, No. 

20 at p. 2; AET, No. 22 at p. 2; ACEEE, 

No. 24 at p. 1; NREL, No. 29 at p. 2; 

Bradford White, No. 30 at p. 2; AHRI, 

No. 33 at p. 4; AO Smith, No. 34 at p. 

3; Joint comment, No. 35 at p. 1; GE, No. 

36 at p. 1; NEEA, No. 37 at p. 3; APGA, 

No. 39 at p. 2; AHRI, No. 46 at p. 1) 

Bradford White indicated its support 

for a 24-hour simulated use test because 

it is ‘‘technology blind.’’ (Bradford 

White, No. 2 at p. 2) PGE and SCE 

recommended that the draw pattern be 

modified to reduce bias towards 

tankless water heaters, and that different 

draw patterns be applied based on the 

capacity of the water heater. (PGE, No. 

3 at p. 2; SCE, No. 4 at p. 2) Stone 

Mountain Technologies indicated that 

recent studies have shown that the 

efficiency of most gas-fired tankless 

models is overstated using the current 

DOE test procedure. The commenter 

stated that this finding, along with the 

addition of small water heaters within 

the scope of the test procedure, 

necessitate a modification to the current 

draw pattern. Further, Stone Mountain 

Technologies opined that an appropriate 

number of draws for a practical test 

method would be between 10 and 15. 

(Stone Mountain Technologies, No. 5 at 

p. 2) AO Smith and AHRI supported 

revising the test procedure while 

retaining the simulated-use concept and 

indicated that an AHRI industry effort is 

underway to develop a modified draw 

pattern. (AO Smith, No. 8 at p. 2; AHRI, 

No. 12 at p. 2; AHRI, No. 33 at p. 4; AO 

Smith, No. 34 at p. 3) AHRI submitted 

a proposed revised energy factor test 

method to DOE, which was considered 

for today’s NOPR and is discussed 

below. (AHRI, No. 46, pp. 1–7) NEEA 

stated that it is clear that the draw 

pattern used in the current test 

procedure bears no resemblance to that 

seen in actual use, and accordingly, the 

current draw pattern should be 

abandoned. (NEEA, No. 9 at p. 2) NREL 

commented that the draw patterns in 

the new test must be statistically 

representative of actual usage, meaning 

that the frequency distributions of key 

variables in the test procedure (such as 

volume of draws and timing between 

draws) are reasonably matched to field 

data. Furthermore, it commented that 

DOE should ensure that any proposed 

test draw profile must be consistent 

with all relevant statistical distributions 

determined from the database of hot 

water draws created by the Lawrence 

Berkeley National Laboratory (LBNL). 

(NREL, No. 14 at pp. 1–2, 8) NREL also 

mentioned the efforts underway by 

ASHRAE to develop a test method based 

on multiple draw patterns that have 

different total draw volumes that are 

appropriate for water heaters of different 

sizes. (NREL, No. 29 at p. 2) NEEA 

likewise discussed these efforts by 

ASHRAE. (NEEA, No. 27 at p. 2) 

GTI discussed the effect of a greater 

number of draws during the test on the 

efficiency rating of instantaneous water 

heaters, and presented data on 

estimated energy factors and efficiencies 

under different draw patterns. (GTI, No. 

15 at pp. 6–9) NRCan discussed changes 

being proposed to the committee 

responsible for Canadian Standards 

Association (CSA) P.3—Testing Method 

for Measuring Energy Consumption and 

Determining Efficiencies of Gas-Fired 

Storage Water Heaters. The committee 

is considering changing the current 

draw pattern and replacing it with a 

new pattern of 10 to 15 draws spread 

throughout the day, with the volume 

and time of each draw varying. NRCan 

also provided data from a field study in 

Ontario that included information on 

hot water draw patterns. (NRCan, No. 16 

at p. 2) NRDC urged DOE to examine the 

existing data on draw patterns and to 

conduct its own further testing if 

necessary. (NRDC, No. 20 at p. 2) AET 

commented that the draw patterns need 

to be more realistic in terms of the 

number of repeated small draws and 

that it is important for tank-type, 

instantaneous, and tankless water 

heaters to all be rated using the same 

draw patterns for a given capability 

range, because comparisons among 

them will otherwise have little meaning. 

(AET, No. 22 at p. 2) ACEEE commented 

that the current draw pattern is no 

longer adequate for generating the 

information that consumers need to 

make wise purchasing decisions. In 

ACEEE’s view, the six-draw test does 

not reflect patterns seen in field studies 

and that the current six-draw pattern is 

inadequate, primarily because different 

technologies that may lead to the same 

energy use in typical applications 

would get quite different EF ratings in 

the lab. (ACEEE, No. 24 at p. 1) 

Standards Committee 118.2 of ASHRAE 

submitted minutes from a meeting held 

on June 28, 2011, indicating that the 

committee passed motions to develop 

new draw patterns for a simulated-use 

test. (ASHRAE, No. 25 at pp. 1–2) 

Fifteen commenters supported the 

implementation of different draw 

patterns based upon water heater 

capacities. Bradford White proposed 

three different draw patterns that would 

be applicable to water heaters of low 

use, normal-to-high use, and heavy-duty 

use. (Bradford White, No. 2 at pp. 5–6; 

Bradford White, No. 30 at pp. 13–15) 

PGE and SCE recommended that DOE 

prescribe draw patterns based on ranges 

of capacities of units or based upon 

burner size for tankless units. (PGE, No. 


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66212 Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 

3 at p. 2; SCE, No. 4 at p. 2) Stone 

Mountain Technologies stated that the 

flow rate during individual draws and 

the total volume drawn during the test 

should be based on the hot water 

delivery capacity of the model. 

Furthermore, Stone Mountain 

Technologies suggested that the 

capacity should be based on the 

theoretical volume of hot water that can 

be delivered in 15 minutes using the 

energy storage and the net heat input. 

(Stone Mountain Technologies, No. 5 at 

p. 2) AHRI and AO Smith recommended 

that DOE should develop a simulateduse test that will vary for differing 

models based on some specified 

criterion such as storage volume or flow 

rate or other appropriate characteristic. 

(AHRI, No. 12 at p. 2; AO Smith, No. 8 

at p. 2) NEEA indicated that its own 

laboratory testing and that of some 

others suggest that multiple draw 

patterns (perhaps 3 to 5) would be 

appropriate, depending on the capacity 

of the water heater. (NEEA, No. 9 at p. 

2) NRCan indicated that the CSA P.3 

committee is considering 3 or 4 

categories for daily hot water use 

households: Low, medium, high, and, 

potentially, a point-of-use category. The 

water heaters would be categorized by 

first-hour rating, maximum gallons per 

minute, or maximum heat input. 

(NRCan, No. 16 at p. 2) General Electric 

commented that the draw pattern 

should be proportionately scaled up for 

large volume water heaters (greater than 

50 gallon capacity) and, similarly, 

scaled down for smaller water heaters 

(less than 50 gallons). (GE, No. 21 at p. 

2) ACEEE stated that DOE must use 

different draw patterns for water heaters 

of different capacities and suggested 

that manufacturers should be allowed to 

choose how a particular product is 

rated. (ACEEE, No. 24 at p. 2) In 

response to the January 2013 RFI, the 

joint commenters recommended 5 

different draw patterns for sizes ranging 

from point-of-use to very high use 

household/light commercial. The joint 

commenters noted work by LBNL and 

Stone Mountain Technologies in 

devising a capacity rating based on 

published storage volume and heat 

source size. (Joint comment, No. 35 at p. 

2) GE commented that water heaters 

should be tested based on their capacity 

as measured by the first-hour rating. 

(GE, No. 36 at p. 1) 

AHRI provided a suggested simulated 

use test that described four different 

draw patterns that would be applied to 

a water heater based on its first-hour 

rating or maximum flow rate 

measurement. (AHRI, No. 46 at pp. 5– 

6) As explained below, AHRI suggested 

cut-offs between the four different size 

categories at first-hour ratings of 20, 55, 

and 80 gallons and at maximum flow 

rates of 1.5, 2.5, and 3.5 gallons per 

minute; all values correspond to a 

nominal outlet temperature of 135 °F 

and a nominal inlet temperature of 58 

°F. The draw patterns are based on a set 

of activities that would be expected in 

a typical residence, with the total 

volume removed per day for the four 

patterns being 15, 40, 64.2, and 82.75 

gallons. The draw pattern for point-ofuse water heaters involved 11 draws, 

while the other three draw patterns 

involved 12 draws each. Flow rates 

varied for each draw during the draw 

pattern, except for the point-of-use draw 

pattern which imposed a fixed flow rate 

of 1 gallon per minute throughout the 

test. 

Applied Energy Technology 

acknowledged the need to test a water 

heater according to a draw pattern 

appropriate for its delivery capacity, but 

instead of supporting a suite of tests for 

water heaters of different capacity, it 

recommended that DOE consider a test 

approach applicable to water heaters of 

all sizes from which pieces of 

information are obtained pertaining to 

the particular capacity of the water 

heater under test. AET’s suggested test 

method entails a series of draw clusters 

that simulate different end uses in a 

residence. Water heaters with a high 

capacity could presumably deliver 

sufficiently hot water at all times during 

the test, but water heaters with lower 

capacity may fail to provide water at a 

required temperature under those draw 

clusters that called for large volumes of 

hot water in a short time. Under AET’s 

approach, a water heater would be rated 

for those clusters during which it could 

meet the demand placed upon it as 

determined by the outlet temperature 

during those draw clusters. (AET, No. 

22 at pp. 18–37) AET commented that 

details of the test method needed to be 

refined, and no discussion was provided 

as to how to use the efficiency 

determined during each draw cluster for 

which the water heater could meet the 

demand to yield an energy factor. 

DOE has tentatively concluded that 

the current DOE test procedure’s draw 

pattern applied during the simulateduse test can potentially yield results that 

are biased towards particular waterheating technologies. The DOE test 

procedure specifies a small number of 

draws per day when compared to 

typical usage, a relatively large time 

between draws, and uniform volumes of 

water per draw. The test procedure 

applies to all water heater technologies 

without regard to any inherent 

differences in performance across the 

technologies. A revised draw pattern in 

the simulated-use test that better reflects 

how water is actually used in different 

homes using different water heater 

technologies could allow for a more 

realistic representation of the expected 

energy consumption consumers would 

experience for a particular water heater 

technology. 

A test procedure that is completely 

uniform across all water heater types 

and sizes (i.e., no differences in the 

amount of hot water drawn or the 

number of draws, etc.) can provide 

results that are biased toward different 

water heater technologies. For electric 

resistance and fossil fuel-fired storage 

water heaters, the predominant factor 

affecting the energy factor is the total 

amount of water removed per day. At a 

given set point temperature, the water 

heater loses heat to the environment at 

an essentially constant rate regardless of 

the amount of water removed. Since the 

energy factor is the ratio of hot water 

energy delivered to the overall energy 

consumed by the water heater, which is 

a sum of that needed to heat the water 

and that which is lost to the 

environment, the energy factor increases 

when the numerator of that ratio 

increases. Hence, the energy factor 

increases when the amount of water 

delivered per 24 hours increases. The 

performance of these water heaters is 

not expected to depend upon the length 

of draws, the flow rates of draws, nor 

the spacing between the draws. 

Storage water heaters that rely on heat 

pump technology show the same 

efficiency trend with overall delivered 

water volume per day as seen with other 

storage water heater technologies, but it 

is also expected that the energy factors 

would depend upon the way that water 

is distributed among draws. A heat 

pump water heater operates most 

efficiently when the heat pump portion 

of the water heater provides the heat to 

the water as opposed to any backup 

electric resistance heating. This backup 

resistance heating is needed when the 

hot water in the appliance is depleted 

and a rapid amount of heat needs to be 

delivered to raise the stored water 

temperature back to the desired value. 

Since heat pumps tend to have a low 

heating rate, heat pump water heaters 

currently on the market incorporate 

resistance elements to provide that 

rapid heating. These resistance 

elements, however, dramatically reduce 

the efficiency. In the current test 

procedure, water heaters that have been 

tested do not require backup electric 

resistance heating to maintain an 

adequate water temperature within the 

tank since there is enough time between 

draws for the tank to fully recover to a 


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temperature that is above that which 

triggers the resistance elements. If a 

revised draw pattern would require a 

larger amount of water to be drawn from 

the water heater in a set period of time, 

either through a single larger draw or 

multiple draws spaced close together as 

would be more representative of average 

use, the heat pump water heater may be 

forced to utilize electric resistance 

heating to maintain the required tank 

temperature, and the energy factor 

would drop. 

For small storage water heaters in the 

‘‘point-of-use’’ category (water heaters 

that generally are not intended to serve 

as a single water heater for all uses in 

a household), a test utilizing the current 

draw pattern would likely result in 

delivery of water during the draws that 

is below a temperature that would be 

considered useful by the resident. These 

units have a small stored volume of hot 

water that is appropriate for small uses 

such as hand washing but not for a draw 

of more than 10 gallons at 3 gallons per 

minute (gpm), as is imposed by the 

current test procedure. An efficiency 

test that takes into account these 

limitations should put a demand on the 

water heater that calls for individual 

draws less than those implemented in 

the current DOE test. 

Draw patterns and water heater 

cycling frequency likely have an effect 

on the measured efficiency of 

instantaneous water heaters. 

Instantaneous water heaters typically 

use large burners or heating elements to 

heat the water from the inlet 

temperature to the outlet temperature as 

it flows through the appliance. The 

burner typically is not energized until a 

water draw is initiated. Once the draw 

stops, the burner is shut off, and the 

remaining water in the appliance and 

the material making up the appliance 

gradually lose their heat and return to 

the ambient temperature. This heat loss 

(losses associated with heating up and 

cooling off of the burner) is considered 

a cycling loss, as the loss is associated 

with the cycling on and off of the water 

heater’s main energy input. 

Draw patterns affect water heater 

cycling and, thus, the overall measured 

efficiency of the water heater. Shorter 

draws typically act to lower the 

measured efficiency because, as the 

water heater cycles more frequently, 

cycling losses increase. Further, cycling 

losses account for a larger portion of 

energy usage during shorter draws, 

resulting in a disproportionate amount 

of heat input going towards raising the 

temperature of the heat exchanger as 

opposed to raising the temperature of 

the water. Hence, shorter draws 

typically result in a lower measured 

efficiency. However, draws that are 

clustered closer together typically act to 

raise the measured efficiency by 

reducing cycling losses because the 

appliance may be able to maintain an 

elevated temperature between the end of 

one draw and the initiation of a 

subsequent draw. The cycling losses are 

mitigated by the fact that the appliance 

does not cool down as much after the 

end of one draw and thus does not need 

to be heated as much when the 

subsequent draw is initiated. Hence, 

shorter spacing between draws typically 

results in an increase in the water 

heater’s measured efficiency. 

The efficiency of instantaneous water 

heaters is less affected by the total 

volume of hot water delivered per day 

than storage water heaters because their 

standby losses (i.e., losses associated 

with a water heater in standby mode, 

independent of the cycling losses 

discussed above) are negligible. Standby 

losses increase measured energy 

consumption without a corresponding 

increase in energy delivered, thereby 

decreasing the energy factor. An 

increase in the volume of water 

delivered per day results in a nearly 

proportional increase in energy 

consumption for instantaneous water 

heaters. The other drivers of total energy 

consumption are standby heat loss and 

cycling heat loss, with standby heat loss 

being essentially constant during the 

test and cycling losses being a function 

of the number of draws and their 

spacing. As these two losses approach 

zero, the dependence of energy factor on 

daily draw volume decreases since the 

energy consumption is dominated by 

that needed to heat the water, which 

vary proportionally. For water heaters 

currently on the market, the cycling 

losses experienced by instantaneous 

water heaters tend to be much less than 

the standby losses experienced by 

storage water heaters. Because standby 

losses increase measured energy 

consumption without a corresponding 

increase in energy delivered, the total 

energy consumption for instantaneous 

water heaters is much closer to the 

energy needed to heat the water than 

that seen with storage water heaters, and 

the dependence on daily draw volume 

is also lower. 

The flow rate at which water is drawn 

from the water heater may affect the 

measured efficiency of an instantaneous 

water heater. The heat transfer from the 

heat exchanger to the water is a function 

of the speed at which water moves 

through the heat exchanger; efficiency 

may increase at higher flow rates. 

Additionally, since instantaneous water 

heaters typically employ heating 

elements or burners with variable 

capacity to meet the desired outlet 

temperature at different flow rates, the 

efficiency of the heat input device (e.g., 

burner or heating element) may also 

vary depending upon the heating rate. 

This effect could either increase or 

decrease the overall efficiency 

depending upon the setting to which the 

heating element or burner is tuned. 

To summarize, under the current DOE 

test procedure, certain types of water 

heaters can provide results that are 

biased toward certain water heater 

technologies. The small number of 

draws imposed under the existing test 

procedure, relative to the actual number 

of draws noted in field usage data, 

reduces the measured cycling losses 

relative to those occurring in field 

conditions. By contrast, the duration of 

time between draws in the test 

procedure is relatively long when 

compared to field usage data, which 

effectively increases the measured 

cycling losses relative to those occurring 

in field conditions. Water heaters with 

low heating rates would appear to 

benefit since they could easily recover 

to operational temperature. 

The current DOE test procedure does 

not adequately measure energy 

efficiency during a representative 

average use cycle or period of use for 

some technologies. The uniform volume 

taken during each draw of the current 

test method does not simulate highdemand use, such as a long shower, that 

could change the way that a water 

heater operates, nor does it simulate 

performance under short draws during 

which water is not delivered at the 

prescribed set point temperature. 

Furthermore, DOE agrees with 

commenters who stated that the draw 

patterns should be based on the delivery 

capacity of the water heater because, as 

explained above, the measured water 

heater efficiency is influenced by the 

draw pattern incorporated into the test 

procedure and because a single draw 

pattern is not appropriate for the range 

of water heater sizes that fall under the 

scope of this test procedure. 

Consequently, DOE proposes a revised 

simulated-use test that involves four 

different draw patterns for water heaters 

of different capacities. Water heaters 

would be classified into the following 

usage categories (described below) 

corresponding to their usage capacity: 

(1) Point-of-use; (2) low; (3) medium; 

and (4) high. The proposed 

classifications are based on delivery 

capacity as determined in a first-hour 

rating test for storage-type water heaters 

or a maximum flow rate test for 

instantaneous water heaters. 

In crafting a proposed set of draw 

patterns, DOE considered and utilized 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
66214 Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 

13Lutz, 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 October 18, 2013). 

14ASHRAE 2011, Handbook of HVAC 

Applications, Chapter 50 Service Water Heating 

(Available at: https://www.ashrae.org/resourcespublications/handbook). 

15A set point temperature is the temperature that 

the user selects via a thermosat as the temperature 

of the delivered hot water at the outlet of the water 

heater. 

the recommended draw patterns 

submitted by commenters, in particular 

those submitted by Bradford White 

(Bradford White, No. 2 at p. 3; Bradford 

White, No. 30 at p. 11), AHRI (AHRI, 

No. 46 at p. 3), and AET (AET, No. 22 

at p. 1). (DOE notes that no test data 

were supplied with any of the proposed 

test methods.) Additionally, DOE 

utilized data compiled by the LBNL 13

that describes field studies of hot water 

usage to ensure that the draw patterns 

were representative of field use. LBNL 

found that typical usage in residences in 

North America is characterized by a 

large number of small volume draws, by 

a smaller volume of water per day than 

is currently prescribed in the residential 

test method, and by a significant 

variation in draw volume and number of 

draws per day. The data suggest 

development of a single typical draw 

pattern would be difficult and 

inappropriate. Instead, DOE has 

attempted to develop several draw 

patterns that capture key features 

affecting performance (e.g., length and 

frequency of draws, flow rates), while 

maintaining a test that will not be overly 

burdensome to conduct and which will 

produce repeatable results. 

Based upon this understanding, DOE 

proposes the following draw patterns 

containing volumes per day that are 

consistent with the data found by LBNL. 

The proposed low-use pattern calls for 

the water heater to provide 38 gallons 

per day, which is consistent with the 

median values found for households 

with 1 to 2 occupants. The proposed 

medium-use pattern, which requires a 

supply of 55 gallons per day, is 

consistent with the median values 

found for households with 3 to 4 

occupants. The LBNL data show a 

median volume of hot water used for 

families with 5 or more occupants to be 

approximately 58 gallons. This 

unexpectedly low result might be 

attributable to the lower sample number 

of such large households. For this 

reason, DOE has departed from the 

LBNL field data and proposes a total 

volume of 84 gallons per day for the 

high-use pattern. This value is 

consistent with that proposed by 

Bradford White (Bradford White, No. 2 

at p. 5) and AHRI (AHRI, No. 46 at p. 

6), and DOE believes that it is a 

representative number for high use 

cases based on the range of hot water 

usage per day reported by LBNL. While 

the LBNL report suggests that the 

number of draws of hot water per day 

could exceed 50, DOE has tentatively 

determined that imposing a draw 

pattern during a test with that many 

draws could lead to measurement 

difficulties owing to (1) the need to 

measure energy removal in such short 

draws; and (2) the potential variation 

inherent in precisely controlling so 

many draws. Accordingly, DOE has 

tentatively concluded that a smaller 

number of draws (ranging from 9 to 14) 

will strike a balance between the need 

to capture cycling losses associated with 

water heater operation and the need for 

accurate measurement. Additionally, 

many of the short draws found in field 

tests are clustered close together in time. 

In these situations, cycling losses are 

negligible because the water heater 

remains at operational temperature over 

the course of the smaller draws. For 

these draws, energy efficiency can be 

reliably estimated by consolidating the 

multiple draws into a single larger draw. 

As discussed in section III.F, ‘‘Test 

Conditions,’’ DOE proposes that both 

the first-hour rating test and the 

maximum flow rate test will be carried 

out with the prescribed outlet water 

temperature at 125 °F. DOE proposes to 

modify the first-hour rating test to stop 

draws of hot water when the outlet 

water temperature drops 15 °F below its 

maximum temperature during each 

draw. This cut-off temperature is a 

departure from the current test, which 

cuts off the draw when the outlet water 

temperature drops 25 °F below the 

maximum recorded outlet temperature. 

With the nominal delivery temperature 

being 135 °F in the current test 

procedure, the cut-off temperature is 

110 °F. This proposed change in 

temperature drop to trigger the end of a 

draw would maintain the approach that 

the minimum useful temperature of hot 

water is 110 °F. This value is consistent 

with Table 3, Chapter 50 of the 

ASHRAE Handbook of HVAC 

Applications,14 which indicates that a 

representative temperature for showers 

and tubs is 110 °F. For water heaters 

with rated storage volumes at or above 

20 gallons, water will continue to be 

drawn at 3 gallons per minute during 

the first-hour rating test. For water 

heaters having rated storage volumes 

below 20 gallons that are not designed 

to provide a continuous supply of hot 

water, water will be drawn at a rate of 

1 gallon per minute during the first-hour 

rating test. A water heater that is 

designed to provide a continuous 

supply of hot water at the set point 

temperature 15 will be tested to obtain a 

maximum flow rate, while water heaters 

that are not so designed will be subject 

to a first-hour rating test. 

DOE proposes the following ranges of 

first-hour ratings and maximum flow 

rates to characterize storage and 

instantaneous water heaters, 

respectively: 

Point-of-use: 

First-Hour Rating less than 20 gallons. 

Maximum Flow Rate less than 1.7 

gallons per minute (gpm). 

Low: 

First-Hour Rating greater than or 

equal to 20 gallons, less than 55 

gallons. 

Maximum Flow Rate greater than 1.7 

gpm, less than 2.8 gpm. 

Medium: 

First-Hour Rating greater than or 

equal to 55 gallons, less than 80 

gallons. 

Maximum Flow Rate greater than or 

equal to 2.8 gpm, less than 4 gpm. 

High: 

First-Hour Rating greater than or 

equal to 80 gallons. 

Maximum Flow Rate greater than or 

equal to 4 gpm. 

DOE based these proposed ranges (or 

‘‘bins’’) on first-hour rating data for 

existing models, requirements of the 

current plumbing code, and 

recommended cut-offs proposed by 

Bradford White and AHRI. (Bradford 

White, No. 2 at pp. 4–5; Bradford White, 

No. 30 at p. 2; AHRI, No. 46 at p. 4) In 

today’s NOPR, DOE proposes to modify 

the set point temperature from the 

current 135 °F to 125 °F, as discussed 

further in section III.F.1. While it is 

acknowledged that the published firsthour rating data were taken at a set 

point temperature of 135 °F, limited 

testing shows that first-hour ratings at a 

set point temperature of 125 °F are 

comparable to those at 135 °F. The firsthour ratings of all water heaters on the 

market cluster around certain values to 

accommodate different levels of use. 

Those clusters are captured in the bins 

proposed here. DOE’s proposed bins 

differ from those presented by Bradford 

White in its comments on the October 

2011 RFI and the January 2013 RFI, 

because the commenter’s approach 

grouped medium-use and high-use 

water heaters into a common category 

and added a category for water heaters 

meant for so-called ‘‘heavy-duty use.’’ 

(Bradford White, No. 2 at pp. 4–5) DOE 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 66215 

16 International Association of Plumbing and 

Mechanical Officials, ‘‘2012 Uniform Plumbing 

Code’’ (2012) (Available at www.iapmo.org) (last 

accessed March 29, 2013). 

17For point-of-use models, the flow rate is 

specified as the lesser of 1 gpm or the maximum 

gpm. Therefore, if a unit were to have a maximum 

gpm rating below 1.0 gpm, that unit would be tested 

at its maximum gpm flow rate. 

has tentatively concluded that the 

categories defined by Bradford White 

group too many water heaters in the 

mid-use category. DOE’s proposed firsthour rating categories match those 

proposed by AHRI. DOE believes that 

these breakpoints are appropriate based 

on minimum first-hour ratings required 

by the Uniform Plumbing Code.16 The 

code mandates minimum first-hour 

ratings for water heaters serving homes 

with different combinations of 

bedrooms and bathrooms. Four different 

minimum values are implemented by 

the code: 42, 54, 67, and 80 gallons. 

DOE has tentatively concluded that its 

proposed usage categories are 

appropriate, given that they are 

consistent with the Uniform Plumbing 

Code, albeit with certain minor 

modifications. In considering the 

Uniform Plumbing Code, DOE 

considered 42 gallons per day as a lower 

limit for the low-use category, but 

concluded that it would not be realistic 

for a water heater intended to provide 

point-of-use functionality to deliver up 

to that level of water in one hour. 

Instead, DOE has tentatively decided to 

set the upper limit for point-of-use 

water heaters and the lower limit for 

low-use water heaters at 20 gallons per 

day. While water heaters with first-hour 

ratings below 42 gallons per day may 

not be used as a single water heater for 

whole-house applications, DOE believes 

that their use more closely resembles 

that of low-use water heaters rather than 

that of point-of-use water heaters. DOE 

has grouped homes with 2 to 4 

bedrooms and less than 3 bathrooms in 

the medium category, which would 

require minimum first-hour ratings of 54 

or 67. Five bedroom homes with up to 

2.5 bathrooms or homes with three or 

more bathrooms would require water 

heaters with first-hour ratings at least 80 

gallons per day; these water heaters fit 

into the proposed high-use category. 

DOE acknowledges the uncertainty in 

using data generated under the existing 

test procedure, which are based on a 

first-hour rating test conducted at a 

delivery temperature of 135 °F, for 

establishing bins for the applicable draw 

patterns. Testing by DOE has indicated 

that storage water heaters with relatively 

high recovery rates yield higher firsthour ratings under the proposed 

procedure than under the current 

procedure, while those with low 

recovery rates tend to have slightly 

lower first-hour ratings at 125 °F 

compared to the rating at 135 °F. DOE 

seeks comments related to the 

translation of current first-hour ratings 

to a first-hour rating determined using 

the proposed 125 °F set point and the 

proposed breakpoints between the 

different size categories. This is 

identified as issue 2 in section V.E, 

‘‘Issues on Which DOE Seeks 

Comment.’’ 

The proposed maximum gpm ratings 

for instantaneous water heaters were 

devised based on expected uses for 

water heaters serving applications of 

different sizes. The categorizations are 

consistent with those suggested by 

AHRI, with the ratings being scaled up 

to account for the higher maximum flow 

rates expected at the lower set point 

temperature (125 °F). 

DOE seeks comment on the proposed 

criteria for characterizing water heaters 

as point-of-use, low usage, medium 

usage, and high usage, and whether 

these criteria are appropriate and 

sufficient. This is identified as issue 3 

in section V.E, ‘‘Issues on Which DOE 

Seeks Comment.’’ 

For each sizing category, DOE 

proposes to apply a 24-hour simulateduse test to determine the energy factor. 

One of four separate draw patterns 

would be applied to each water heater 

based on the appropriate sizing 

category. The draw patterns would have 

the following number of draws per day: 

Point-of-use: 9; low: 11; medium: 12; 

and high: 14. DOE acknowledges that 

the number of draws per day in a typical 

household can often approach 100 and 

that the volume in each draw can be 

very small. However, DOE believes that 

a test with so many draws would be 

subject to large variability in results due 

to the challenges in accurately 

determining the energy content of such 

short draws. In contrast, DOE has 

tentatively concluded that the proposed 

draw patterns would capture the key 

ways in which hot water is used in 

residences while yielding a test that is 

repeatable. 

DOE’s proposal uses a slightly 

modified version of the draw patterns 

submitted by Bradford White and AHRI 

in response to the January 2013 RFI as 

a basis for the low, medium, and high 

draw patterns; Bradford White did not 

submit a draw pattern for point-of-use 

water heaters. In addition, the patterns 

presented by Bradford White grouped 

medium-use water heaters with heavy 

use, so data were missing for both pointof-use and medium use water heaters. 

Additionally, information provided by 

AET has also been considered to craft 

some aspects of the draw patterns. AET 

provided information on typical uses 

that would be applied to a water heater 

in terms of flow rates, number of draws, 

and volumes. (AET, No. 22 at pp. 22– 

36) This information was utilized in 

drafting the proposed draw patterns for 

point-of-use and medium-use water 

heaters. 

A number of changes are proposed as 

compared to the current draw patterns 

found in the DOE simulated-use test 

procedure. First, the proposed draw 

patterns would involve more draws than 

are currently implemented, and the 

draws would vary in length during the 

simulated-use test. Second, the spacing 

between the draws would vary to better 

capture the effects of different cycling 

times on the energy efficiency of the 

water heater. Third, the proposed draws 

would involve different flow rates 

during the test; these flow rates would 

be 1.0, 1.7, or 3.0 gpm.17 The total 

volumes that would be removed for 

each category are in line with recent 

field data compiled by the Lawrence 

Berkeley National Laboratory that was 

previously discussed. DOE believes that 

the proposed draw patterns would 

improve the estimation of energy 

efficiency by considering the impact of 

shorter draws, lower flow rates, higher 

number of draws, and variable standby 

times between draws. 

DOE proposes draw patterns for 

implementation in the 24-hour 

simulated-use tests as outlined in Table 

III.2 through Table III.5. The total 

volume of water drawn in the proposed 

draw patterns are 10 gallons for the 

point-of-use pattern, 38 gallons for the 

low-usage pattern, 55 gallons for the 

medium-usage pattern, and 84 gallons 

for the high-usage pattern. 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
66216 Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 

TABLE III.2—POINT-OF-USE DRAW PATTERN

Draw number 

Time during 

test 

(hh:mm) 

Volume 

(gallons) 

Flow rate 

(gpm) 

1 ....................................................................................................................... 0:00 2 Lesser of (1, max gpm). 

2 ....................................................................................................................... 1:00 1 Lesser of (1, max gpm). 

3 ....................................................................................................................... 1:05 0 .5 Lesser of (1, max gpm). 

4 ....................................................................................................................... 1:10 0 .5 Lesser of (1, max gpm). 

5 ....................................................................................................................... 1:15 0 .5 Lesser of (1, max gpm). 

6 ....................................................................................................................... 8:00 1 Lesser of (1, max gpm). 

7 ....................................................................................................................... 8:15 2 Lesser of (1, max gpm). 

8 ....................................................................................................................... 9:00 1 .5 Lesser of (1, max gpm). 

9 ....................................................................................................................... 9:15 1 Lesser of (1, max gpm). 

TABLE III.3—LOW-USAGE DRAW PATTERN

Draw number 

Time during 

test 

(hh:mm) 

Volume 

(gallons) 

Flow rate 

(gpm) 

1 ................................................................................................................................................... 0:00 15 .0 1 .7 

2 ................................................................................................................................................... 0:30 2 1 

3 ................................................................................................................................................... 1:00 1 1 

4 ................................................................................................................................................... 10:30 6 1 .7 

5 ................................................................................................................................................... 11:30 4 .0 1 .7 

6 ................................................................................................................................................... 12:00 1 .0 1 

7 ................................................................................................................................................... 12:45 1 .0 1 

8 ................................................................................................................................................... 12:50 1 .0 1 

9 ................................................................................................................................................... 16:15 2 .0 1 

10 ................................................................................................................................................. 16:45 2 .0 1 .7 

11 ................................................................................................................................................. 17:00 3 .0 1 .7 

TABLE III.4—MEDIUM-USAGE DRAW PATTERN

Draw number 

Time during 

test 

(hh:mm) 

Volume 

(gallons) 

Flow rate 

(gpm) 

1 ................................................................................................................................................... 0:00 15 1 .7 

2 ................................................................................................................................................... 0:30 2 .0 1 

3 ................................................................................................................................................... 1:40 9 .0 1 .7 

4 ................................................................................................................................................... 10:30 9 .0 1 .7 

5 ................................................................................................................................................... 11:30 5 .0 1 .7 

6 ................................................................................................................................................... 12:00 1 .0 1 

7 ................................................................................................................................................... 12:45 1 .0 1 

8 ................................................................................................................................................... 12:50 1 .0 1 

9 ................................................................................................................................................... 16:00 1 .0 1 

10 ................................................................................................................................................. 16:15 2 .0 1 

11 ................................................................................................................................................. 16:45 2 .0 1 .7 

12 ................................................................................................................................................. 17:00 7 .0 1 .7 

TABLE III.5—HIGH-USAGE DRAW PATTERN

Draw number 

Time during 

test 

(hh:mm) 

Volume 

(gallons) 

Flow rate 

(gpm) 

1 ................................................................................................................................................... 0:00 27 3 

2 ................................................................................................................................................... 0:30 2 .0 1 

3 ................................................................................................................................................... 0:40 1 1 

4 ................................................................................................................................................... 1:40 9 .0 1 .7 

5 ................................................................................................................................................... 10:30 15 3 

6 ................................................................................................................................................... 11:30 5 .0 1 .7 

7 ................................................................................................................................................... 12:00 1 .0 1 

8 ................................................................................................................................................... 12:45 1 .0 1 

9 ................................................................................................................................................... 12:50 1 .0 1 

10 ................................................................................................................................................. 16:00 2 .0 1 

11 ................................................................................................................................................. 16:15 2 .0 1 

12 ................................................................................................................................................. 16:30 2 .0 1 .7 

13 ................................................................................................................................................. 16:45 2 .0 1 .7 

14 ................................................................................................................................................. 17:00 14 .0 3 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 66217 

18Healy 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). 

For instantaneous water heaters with 

maximum flow rates less than 1 gpm, 

DOE proposes that the flow rates during 

all draws of the point-of-use test will be 

set at the maximum gpm as determined 

during that test. DOE also proposes to 

tighten the tolerance on the volume 

removed in each draw from 0.5 gallons 

to 0.25 gallons since these patterns 

involve smaller draw volumes than in 

the current procedure. 

DOE proposes to utilize interim 

metrics during testing that would be 

used in calculations to normalize the 

test to standard conditions, as in the 

current test procedure, to account for 

deviations from the prescribed storage 

tank temperature, ambient temperature, 

water delivery temperature, and inlet 

water temperature. The standby loss 

coefficient is one interim metric that 

would be determined during the longest 

standby portion of each test in which no 

recovery or draws are taking place. The 

recovery efficiency is a second interim 

metric that would be determined based 

on the first draw of each test, with the 

energy supplied and consumed during 

subsequent draws being accounted for 

when a complete recovery does not 

occur prior to the second draw. 

DOE proposes to abandon the 

determination of recovery efficiency at 

different flow rates as currently done for 

instantaneous water heaters; test data 

have shown the difference between 

these recovery efficiencies as being less 

than five percent, and the resulting 

effect on the energy factor is negligible. 

DOE notes that the proposed draw 

patterns differ slightly from those 

suggested by AHRI in response to the 

January 2013 RFI. (AHRI, No. 46 at pp. 

5–6) In DOE’s view, the proposed draw 

patterns appropriately differentiate 

between the size categories by 

increasing the number of draws as the 

size of the water heater increases. DOE 

also intends to minimize the different 

number of flow rates required for all 

tests, with the proposed draw patterns 

involving three different flow rates as 

opposed to the four specified by AHRI. 

The patterns proposed here have also 

been formulated to allow for the 

determination of key performance 

metrics that are needed for computing 

the energy factor, namely recovery 

efficiency and standby loss coefficient. 

DOE believes that the proposed patterns 

will ease those determinations. Finally, 

DOE has conducted testing according to 

the proposed patterns to validate the 

procedure and make adjustments as 

needed, whereas AHRI has not 

indicated that its specific patterns 

presented have been validated. In any 

event, DOE has tentatively concluded 

that the draw patterns proposed in 

today’s NOPR are very similar to the 

patterns proposed by AHRI, and that 

little difference will be observed 

between ratings collected from either 

draw pattern. This assessment is based 

on the fact that the total volumes drawn 

per day for each category are 

comparable, the number of draws per 

day is comparable, and each pattern is 

based on a distribution that represents 

a cluster of draws in the morning and 

another cluster in the evening hours. 

Consequently, DOE has tentatively 

concluded that the patterns proposed in 

this NOPR are consistent with those 

presented by AHRI. DOE seeks comment 

on whether the proposed draw patterns 

for the different water heater size 

categories are appropriate. This is 

identified as issue 4 in section V.E, 

‘‘Issues on Which DOE Seeks 

Comment.’’ 

D. Instrumentation 

DOE proposes to maintain the 

instrumentation installation 

requirements and piping configuration 

as currently specified in the residential 

water heater test procedure. Bradford 

White recommended that the internal 

temperature probe required in the 

current test procedure be eliminated 

and that all exposed piping on the inlet 

and outlet of the water heater be 

eliminated as much as possible. 

(Bradford White, No. 30 at p. 2) DOE is 

concerned that the removal of the 

internal temperature probe would not 

enable the critical correction for stored 

energy inside the water heater, a value 

that could move the energy factor by 

several points. For this reason, DOE 

proposes to maintain the internal 

temperature probe inside the tank of a 

storage water heater. DOE is also 

proposing to maintain the piping 

configuration as currently specified in 

the residential water heater test 

procedure, as some water heaters 

include particular technologies such as 

heat traps that minimize losses through 

piping connections. For storage water 

heaters having a rated volume below 20 

gallons, which are not covered in the 

existing DOE test method, DOE 

proposes that the average tank 

temperature would be determined based 

on three temperature sensors located 

within the storage tank as opposed to 

the currently required six sensors for 

storage water heaters having a rated 

volume above 20 gallons. The three 

sensors would be located at the vertical 

midpoints of three sections of equal 

volume within the tank. For these units, 

DOE believes that three sensors are 

sufficient for determining the mean tank 

temperature and that the use of six 

sensors would provide little extra 

information and may add to the 

parasitic heat losses from these smaller 

units. 

DOE proposes to tighten the allowed 

accuracy on electric power and energy 

measuring equipment from the current 

value of ± 1 percent to ± 0.5 percent. A 

study has shown the significant effect of 

the accuracy of the electric power 

measurements on the uncertainty in the 

overall energy factor.18 An analogous 

change was made in ASHRAE 118.2– 

2006, ‘‘Method of Testing for Rating 

Residential Water Heaters,’’ and DOE 

research confirms that equipment 

having this tolerance level can be 

readily procured. DOE also proposes to 

require that for mass measurements 

greater than or equal to 10 pounds (4.5 

kg), a scale that is accurate within ± 0.5 

percent of the reading be used to make 

the measurement. 

DOE also proposes to modify the data 

acquisition rate of the inlet and outlet 

water temperature during draws. 

Currently, for all water heaters except 

variable firing rate instantaneous water 

heaters, temperature data measurements 

are taken at 5-second intervals starting 

15 seconds after the draw commences. 

For instantaneous water heaters with a 

variable firing rate, temperature data 

measurements are taken at 5-second 

intervals starting 5 seconds after the 

draw commences. The proposed test 

procedure amendments call for 

temperature data at the inlet and outlet 

temperature sensors to be recorded at 3- 

second intervals starting 5 seconds after 

commencement of the draw for all water 

heaters. Accordingly, DOE also proposes 

to require that the time constant of the 

instruments used to measure the inlet 

and outlet water temperatures be no 

greater than 2 seconds. DOE anticipates 

that this approach would better capture 

the energy impact of water heater startup and cycling. 

E. Discrete Performance Tests 

In the October 2011 RFI, DOE 

considered using a series of discrete 

tests as an alternative approach to using 

a single 24-hour simulated-use test to 

determine the energy factor of 

residential water heaters. In a series of 

discrete performance tests, the results of 

various individual tests (e.g., thermal 

efficiency test, recovery efficiency test, 

standby loss test) would be used to 

calculate the energy factor. This 

approach would reduce testing burden, 

yield more repeatable results, and 

provide the ability to predict 


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19ASHRAE Guideline 12, ‘‘Minimizing the Risk of 

Legionellosis Associated with Building Water 

Systems,’’ states that the temperature range most 

favorable for amplification of legionellae bacteria is 

770¥108 0F (250¥42 0C), and that document 

recommends that when practical, hot water should 

be stored at temperatures of 120 0F (49 0C) or above. 

However, the guideline also states that for high-risk 

situations (such as in health care facilities and 

nursing homes), hot water should be stored above 

140 0F (60 0C). For more information visit: 

www.ashrae.org. 

performance over a broader range of 

applications. DOE requested comments 

on the feasibility and equitability of a 

series of discrete tests in the October 

2011 RFI. 76 FR 63211, 63214 (Oct. 12, 

2011). 

Two commenters (ACEEE, NREL) 

supported the general premise of 

discrete performance tests for rating 

water heaters, while acknowledging the 

challenges in implementing such an 

approach. More specifically, NREL 

indicated that studies are needed to 

validate that discrete tests would 

provide a computed energy factor with 

a level of accuracy equal to or better 

than a single simulated-use test. (NREL, 

No. 14 at p. 5) ACEEE indicated that 

discrete tests combined with an 

algorithm to determine the energy factor 

could reduce test time, produce ratings 

at a variety of usage patterns with a 

single set of tests, and could be used to 

account for novel features implemented 

by manufacturers to improve efficiency. 

ACEEE also acknowledged that the 

algorithms would still need to be 

developed and validated, a process with 

an unknown time frame. (ACEEE, No. 

24 at pp. 2–3) 

Eleven commenters (Stone Mountain 

Technologies, AO Smith, NEEA, NPGA, 

AHRI, AGA, GTI, Bosch, NRDC, General 

Electric, and AET) opposed the use of 

discrete tests to determine the energy 

factor. AHRI and AO Smith stated that 

such tests have a limited use relative to 

the wide range of technologies being 

employed in current designs of 

residential water heaters since they 

would not be as equitable as a 

simulated-use approach. (AHRI, No. 12 

at p. 2; AO Smith, No. 8 at p. 2) GTI 

commented that much uncertainty 

remains in the analytical methodology 

for generating rating metrics, its 

comparability across equipment 

categories, and whether the outcome 

would actually yield a simpler and more 

repeatable alternative to the current test 

procedure. (GTI, No. 15 at p. 2) Stone 

Mountain Technologies stated that 

testing and analysis to date do not 

support such an approach. (Stone 

Mountain Technologies, No. 5 at p. 3) 

Bosch expressed support for the current 

draw profile and test approach because 

of what the commenter perceives as the 

extremely low repeatability and 

accuracy of test results at low input 

rates and the lack of data on appropriate 

draw patterns for use in calculating the 

energy factor. (Bosch, No. 17 at p. 2) 

General Electric expressed support for 

the current draw profile and test 

approach, arguing that it would more 

accurately focus on actual results and 

more closely approximate the real-world 

performance of residential water 

heaters. (GE, No. 21 at pp. 1–2) NEEA 

stated that the concept of using discrete 

performance tests to determine energy 

factor is not practical. (NEEA, No. 9 at 

p. 3) AGA commented that discrete 

performance tests have been shown to 

develop inconsistent results and impose 

new uncertainties in testing, and NRDC 

raised questions about the equitability 

of testing between technology types. 

(AGA, No. 13 at pp. 1–2; NRDC, No. 20 

at p. 2) AET stated that it does not 

believe that the approach would work in 

practice because of controls not working 

as designed, the presence of multiple 

operating modes on water heaters, and 

the need to conduct more 

characterization tests than initially 

expected. These issues with discrete 

performance tests would make the 

algorithms used to obtain an energy 

factor prone to error. (AET, No. 22 at pp. 

5–6) 

DOE has decided not to pursue the 

use of discrete performance tests for 

rating the energy efficiency of 

residential water heaters given the 

potential inequity in test results across 

technologies, the added uncertainties in 

ratings, and the general lack of 

potentially suitable algorithms to 

develop an energy factor for water 

heaters. Rather, as discussed previously 

in section III.C, DOE is maintaining the 

single simulated-use test, which DOE 

believes can be a more, technologyblind method for determining the 

energy efficiency (EF) of water heaters. 

F. Test Conditions 

1. Water Delivery Temperature 

The current residential water heater 

test procedure calls for average hot 

water temperature within the storage 

tank to be set for delivery at 135 °F ± 

5 °F (57.2 °C ± 2.8 °C). 10 CFR part 430, 

subpart B, appendix E, section 2.4. 

However, DOE noted in the October 

2011 RFI that the Underwriters 

Laboratories (UL) standards specify that 

manufacturers must ship residential 

water heaters with thermostats set at 

temperatures no greater than 125 °F (52 

°C) to safeguard against scalding hazards 

(UL 174, Standard for Household 

Electric Storage Tank Water Heaters, 

Underwriters Laboratories (April 29, 

2004)). DOE also noted that DOE’s own 

research suggests that although the 

majority of water heaters are shipped 

with the thermostat preset to 120 °F (49 

°C), the average set point in use in the 

field is 124.2 °F (51.2 °C), suggesting 

that some homeowners or installers 

adjust the thermostat. 76 FR 63211, 

63214 (Oct. 12, 2011). 

The set point impacts the 

performance of various types of water 

heaters differently, and as a result, DOE 

reexamined the appropriateness of the 

set point specification in the proposed 

test procedure. As noted in the October 

2011 RFI, a higher delivery temperature 

has a disproportionately large and 

negative impact on heat pump water 

heater efficiency (as compared to other 

types of water heaters), because heat 

pump water heaters can have markedly 

different performance at elevated stored 

water temperature compared to 

temperatures more representative of 

typical residential usage. For other types 

of water heaters, heat transfer 

characteristics between the heating 

source and the water may differ at lower 

delivery temperatures, thereby affecting 

the efficiency. 76 FR 63211, 63214 (Oct. 

12, 2011). 

However, DOE also noted in the 

October 2011 RFI that there are some 

concerns with using a lower set point 

temperature in the test procedure: (1) 

Some end uses (e.g., dishwasher 

operation) require hot water delivered at 

130 °F to 140 °F (54 °C to 60 °C) for 

effective operation; and (2) there may be 

the potential for the growth of 

Legionella in hot water stored below 

135 °F (57 °C).19

DOE sought comment on the 

appropriate set point temperature for 

the residential water heater test 

procedure and the benefits and concerns 

with using a lower temperature. Three 

commenters to the October 2011 RFI 

(Bradford White, Bosch, and General 

Electric) recommended that the set 

point temperature should be kept at its 

current value of 135 °F (57 °C). 

Additionally, two commenters on the 

January 2013 RFI also recommended 

maintaining the set point at 135 °F (57 

°C). (Bradford White, No. 30 at p. 2; 

AHRI, No. 46 at p. 2) Bosch stated that 

this value will maintain harmonization 

with test standards in Canada. General 

Electric indicated that plumbers may 

change the set point, but a lower 

temperature in the test procedure runs 

the risk of encouraging consumer 

dissatisfaction with water heaters that 

are otherwise properly sized for their 

household due not to lack of capacity, 

but to lack of properly adjusted storage 

temperatures. Additionally, General 

Electric indicated that DOE runs the risk 


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of encouraging energy inefficiency in 

actual use at higher set points of water 

heaters designed and optimized to test 

procedures at lower set points. 

(Bradford White, No. 2 at p. 2; Bosch, 

No. 17 at p. 2; GE, No. 21 at pp. 2–3) 

In submitting a suggested test method, 

AHRI noted that it considered lower set 

points but that its recommendation is to 

continue to use 135 °F as the set point 

in the test. AHRI indicated that its 

recommended draw patterns should be 

modified if DOE determines that a 

different set point temperature setting is 

appropriate. (AHRI, No. 46 at p. 2) 

Thirteen comments were submitted 

that recommended that the set point 

temperature be lowered from its current 

value. PGE, SCE, NREL, AET, and 

ACEEE recommended a set point 

temperature of 120 °F (PGE, No. 3 at p. 

2; SCE, No. 4 at p. 2; NREL, No. 14 at 

p. 4; AET, No. 22 at p. 3; ACEEE, No. 

24 at p. 4), while NEEA recommended 

a value of 125 °F. (NEEA, No. 9 at p. 3; 

NEEA, No. 37 at p. 4) In a comment on 

the January 2013 RFI, the joint 

commenters supported a set point 

temperature between 120 °F and 125 °F. 

(Joint comment, No. 35 at p. 3) 

Likewise, Stone Mountain Technologies 

and NRDC recommended a set point 

between 120 °F and 125 °F. (Stone 

Mountain Technologies, No. 5 at p. 3; 

NRDC, No. 20 at p. 2) AHRI and AO 

Smith did not suggest a specific value, 

but recommended that the set point 

temperature be lowered. (AHRI, No. 12 

at p. 2; AO Smith, No. 8 at p 2) AET 

commented that the proposed ASHRAE 

Standard 188, (Standard 188P), 

‘‘Prevention of Legionellosis Associated 

with Building Water Systems,’’ and 

ASHRAE Guideline 12, ‘‘Minimizing the 

Risk of Legionellosis Associated with 

Building Water Systems,’’ are reexamining recommendations for 

preventing the growth of Legionella. 

AET stated that water temperatures in 

the range of 120 °F are adequate to 

prevent Legionella colonies, provided 

that the water is maintained at a 

temperature ‘‘high enough, long enough, 

and often enough.’’ (AET, No. 22 at pp. 

11–12) 

AET commented that the test 

procedure should allow for variable 

delivery temperatures, because some 

point-of-use water heaters are designed 

to deliver water no hotter than 105 °F 

(40.6 °C) to 110 °F (43.3 °C). AET argued 

that no credit should be given to water 

delivered at temperatures above the set 

point temperature, in order to 

discourage temperature overshoots. 

Likewise, AET argued that no credit 

should be given to water delivered at a 

temperature below that which is 

considered useful to the user (i.e., below 

105 °F (40.6 °C)). (AET, No. 22 at p. 13) 

After carefully considering these 

comments, DOE proposes to lower the 

set point temperature of residential 

water heaters in the test procedure to 

125 °F. This value was primarily 

selected based on data available in 

DOE’s analysis for the April 2010 energy 

conservation standards final rule as 

previously discussed, which found that 

the average set point temperature for 

residential water heaters is 124.2 °F 

(51.2 °C). Additionally, the recent 

compilation of field data across the 

United States and southern Ontario by 

LBNL previously referenced found a 

median daily outlet water temperature 

of 122.7 °F (50.4 °C); this value rounded 

to the nearest 5 °F increment supports 

a test set point temperature of 125 °F. 

This new value would apply to firsthour rating tests for storage water 

heaters, maximum flow rate tests for 

instantaneous water heaters, and energy 

factor tests for all water heaters. 

DOE appreciates the comment from 

AET regarding the new proposed 

guidelines for Legionella prevention, 

and tentatively concludes that a set 

point of 125 °F in the test method would 

not result in safety concerns related to 

the growth of Legionella. Further, as 

discussed immediately above, DOE 

notes that water heaters are commonly 

set to temperatures in the range of 120 

°F to 125 °F even though the current set 

point in the test method is 135 °F. DOE 

does not expect consumer behavior 

related to set points to change if the set 

point is lowered in the test method. 

For first-hour rating tests, DOE 

proposes that draws would terminate 

when the outlet temperature drops 15 °F 

(8.3 °C) from its maximum outlet 

temperature during the draw, as 

opposed to the drop of 25 °F (13.9 °C) 

implemented in the current test 

procedure. This change would ensure 

that water delivered meets the nominal 

useful temperature of 110 °F (43.3 °C). 

DOE acknowledges that the Canadian 

test procedure requires testing at 135 °F 

(57 °C), but DOE is responsible for 

developing a water heater test procedure 

that reflects and is appropriate for the 

United States market. In response to 

comments indicating that DOE should 

retain the 135 °F set point temperature, 

DOE believes that the test should be 

conducted at typical operating 

temperatures and should not penalize 

those units optimized for such typical 

conditions. 

GE commented that the set point 

temperature should be based upon the 

outlet water temperature as opposed to 

the average stored water temperature to 

allow newer technologies to be included 

in the protocol and to achieve the goal 

of being technology-neutral. (GE, No. 36 

at p. 2) HTP made a similar assertion 

that the set point should not be based 

on the mean tank temperature, noting 

that requiring a mean tank temperature 

could penalize condensing gas water 

heaters that rely on stratification and 

cooler water at the bottom of the tank 

to achieve better heat transfer resulting 

in the condensation of moisture within 

the flue gases. (HTP, No. 41 at p. 2) Due 

to these concerns, AHRI suggested an 

alternative method for setting the 

thermostat. Instead of setting the 

thermostat based on the mean tank 

temperature as determined by the 

internal tank temperature probe, AHRI 

suggested that the thermostat setting 

should be determined by drawing water 

from the water heater for several 

minutes to determine if the set point 

temperature is achieved. (AHRI, No. 46 

at p. 5) AHRI proposed that the flow rate 

at which the water would be drawn 

during this procedure to set the 

thermostat would be 1 gpm for point-ofuse water heaters and 1.7 gpm for all 

other size storage water heaters. 

DOE agrees in principle with the 

comments and the suggested approach 

presented by AHRI for setting the 

thermostat. After carefully considering 

these comments, DOE acknowledges 

that the current method for setting the 

thermostats of water heaters that rely on 

stratification may lead to outlet water 

temperatures significantly higher than 

would normally be expected in practice, 

since the top of the water heater needs 

to be at an elevated temperature 

compared to the mean temperature to 

meet the requirement that the mean 

temperature fall within the value 

specified in the test procedure. 

However, DOE is not aware of a simple 

method to assure that multiple 

thermostats are set appropriately by 

monitoring outlet water temperature 

during a draw. 

As a result, DOE proposes a method 

for determining the appropriate set 

point temperature that differs slightly 

from that proposed by AHRI. DOE 

proposes to apply the thermostat setting 

procedure that utilizes the outlet 

temperature during a draw, as suggested 

by AHRI, only to water heaters having 

a single thermostat. For water heaters 

with multiple thermostats, DOE 

proposes to maintain the procedure 

currently prescribed in the residential 

water heater test method which utilizes 

the internal tank temperature probes to 

determine if the water heater thermostat 

is set properly. DOE is not aware of any 

technologies that rely on stratification 

that utilize multiple thermostats, so it 

believes that the current approach for 


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setting the thermostat is appropriate for 

water heaters having multiple 

thermostats. DOE is also proposing to 

make a clear distinction by rated 

volume between those water heaters 

using a lower flow rate during this test 

compared to those using a higher flow 

rate since the thermostat setting will 

need to be done prior to the 

experimental determination of whether 

the water heater is to be considered a 

point-of-use water heater. While making 

this adjustment, DOE is maintaining 

calculations to normalize the standby 

loss to a mean tank temperature of 125 

°F ± 5 °F (51.7°C ± 2.8 °C) to ensure 

equitable comparison between water 

heaters. 

DOE is interested in receiving 

comments on both the proposed set 

point temperature of 125 °F ± 5 °F, and 

the proposed approach to setting the 

thermostat for storage water heaters, 

particularly on the appropriateness of 

different methods for water heaters 

having a single thermostat compared to 

those with multiple thermostats. These 

are identified as issues 6 and 7 in 

section V.E, ‘‘Issues on Which DOE 

Seeks Comment.’’ 

2. Ambient Temperature and Relative 

Humidity 

The residential water heater test 

procedure requires that testing be 

performed in an environment with an 

ambient air temperature fixed at 67.5 °F 

± 2.5 °F (19.7 °C ± 1.4 °C). 10 CFR part 

430, subpart B, appendix E, section 2.2. 

For heat pump water heaters, however, 

the environmental conditions are more 

tightly constrained with an ambient air 

temperature requirement of 67.5 °F ± 1 

°F (19.7 °C ± 0.6 °C) and a relative 

humidity requirement of 50 percent ± 1 

percent. Id. These specifications for heat 

pump water heaters reflect the fact that 

heat pump water heater energy use is 

highly dependent on the ambient 

temperature and relative humidity. 

Because water heaters are placed in a 

wide variety of locations within and 

outside of a home, and given the large 

impact of these factors on heat pump 

water heater efficiency, DOE considered 

potential revisions to the ambient air 

test conditions set forth in the DOE test 

procedure in order to assess whether the 

currently-specified conditions are 

representative of conditions typically 

encountered in residential installations. 

In the October 2011 RFI, DOE requested 

comment on the appropriate ambient 

temperature and relative humidity 

testing points and tolerances for all 

types of residential water heaters. 76 FR 

63211, 63214–15 (Oct. 12, 2011). 

DOE received seven comments 

(Bradford White, Stone Mountain 

Technologies, AO Smith, AHRI, Bosch, 

General Electric, and AET) that 

supported the current ambient 

temperature and relative humidity 

conditions. Bradford White suggested 

that DOE should consider relaxing the 

tolerances for temperature and relative 

humidity when testing heat pump water 

heaters since it is very difficult to 

control to those conditions, 

recommending that the allowable 

ambient temperature variation be ± 2.5 

°F and the allowable variation in 

relative humidity be ± 5 percent. 

(Bradford White, No. 2 at p. 2; Stone 

Mountain Technologies, No. 5 at p. 3; 

AO Smith, No. 8 at p. 2; AHRI, No. 12 

at p. 2; Bosch, No. 17 at p. 2; GE, No. 

21 at p. 3; AET, No. 22 at p. 4) 

NEEA submitted for DOE 

consideration as a test method a test 

plan that has been implemented in the 

Pacific Northwest in which heat pump 

water heaters are tested at both the 

current DOE specifications and at a 

second point with the ambient 

temperature at 50 °F (10 °C) and the 

relative humidity at 58 percent. A binweighted calculation using these two 

points would yield an energy factor, and 

NEEA stated that it believes that these 

conditions are more appropriate than 

the current ones for installations in the 

northern half of the United States and 

would lead to better estimates of the 

actual performance in the field. (NEEA, 

No. 9 at p. 3) NEEA reiterated the desire 

to test at multiple conditions in 

response to the January 2013 RFI. 

(NEEA, No. 37 at p. 5) NRDC indicated 

that the conditions need to be reexamined but did not offer any 

suggestions. (NRDC, No. 20 at p. 2) 

ACEEE suggested that DOE should 

evaluate changing the ambient 

temperature to 50 °F or other such value 

that approximates the national average 

winter basement temperature. (ACEEE, 

No. 24 at p. 3) Davis Energy Group 

presented data from a survey of homes 

in California that reported average 

ambient temperatures that ranged from 

65.4 °F to 71.7 °F. (Davis Energy Group, 

No. 6 at p. 1) 

After carefully considering these 

comments, DOE proposes to maintain 

the current ambient dry bulb 

temperature of between 65 °F and 70 °F 

when testing water heaters other than 

heat pump water heaters and at 67.5 °F 

± 1 °F when testing heat pump water 

heaters. DOE also proposes to maintain 

relative humidity at 50 percent, but to 

relax the tolerances to ± 2 percent 

relative humidity. DOE believes these 

conditions are generally representative 

of typical field conditions encountered 

by water heaters installed in the U.S. 

and has not found any data to justify 

changing these conditions. DOE 

proposes to relax the tolerance for 

relative humidity because research 

indicates that commonly-used, 

laboratory-grade relative humidity 

sensors have uncertainties on the order 

of 1 to 1.5 percent. For this reason, the 

tolerance cannot be expected to be 

below the accuracy in measuring that 

value. It should be noted, however, that 

the relative humidity can be obtained 

from measurements of dry bulb and wet 

bulb temperatures, and the 

determination of relative humidity 

through these temperature 

measurements would result in a 

measure of relative humidity with much 

lower uncertainty since dry bulb and 

wet bulb temperatures can be measured 

with high accuracy. However, most 

laboratories use relative humidity 

sensors which provide an accurate but 

less burdensome method for measuring 

relative humidity. DOE is also 

proposing to add a statement to the 

instrumentation section that specifies 

that the accuracy of relative humidity 

sensors shall be within ± 1.5 percent 

relative humidity. 

3. Laboratory Airflow 

The existing test procedure specifies 

that the water heater shall be set up in 

an area that is protected from drafts. To 

clarify this statement, DOE proposes to 

add a stipulation that the area be 

protected from drafts of more than 50 ft/ 

min (2.5 m/s). This value is in 

accordance with specifications in 

Canadian Standard 745–03, ‘‘Energy 

Efficiency of Electric Storage Tank 

Water Heaters and Heat Pump Water 

Heaters.’’ 

G. Annual Energy Consumption 

Calculation 

The annual energy consumption is 

calculated for residential water heaters 

in the existing test procedure based on 

the daily energy consumption 

multiplied by 365 days. In a letter 

submitted to the FTC on September 16, 

2013, regarding the labeling of 

residential water heaters, AHRI pointed 

out that calculating the annual energy 

consumption based on the daily energy 

consumption can lead to differing 

annual energy consumption, and 

consequently, differing estimated yearly 

operating costs, for water heater models 

with the exact same EF rating. AHRI 

specifically provided an example of two 

water heaters with differing daily energy 

consumption values, but with EF values 

that would round to the same value 

based on the DOE rounding 

requirements provided in 10 CFR 

430.23(e). AHRI stated that having 

slightly different yearly operating cost 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 66221 

20Healy 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). 

estimates for two water heaters with the 

same efficiency rating can be confusing 

to consumers, and somewhat misleading 

based on the accuracy of the test 

method. AHRI suggested revising the 

calculation of the annual energy 

consumption so that it is based on the 

EF rating. 

DOE agrees with AHRI regarding the 

calculation of the annual energy 

consumption and the accuracy of the 

test method. As a result, DOE proposes 

to adopt the calculation method 

suggested by AHRI for annual energy 

consumption, which is based on the 

nominal energy consumed during the 

test and the energy factor rating, rather 

than the daily energy consumption. 

H. Conversion of Existing Energy Factor 

Ratings 

The proposed test procedure 

amendments could result in some types 

of water heaters reporting some 

numerical changes in EF due to the 

proposed changes in the draw pattern, 

set point temperature, and water 

delivery temperature. However, the 

extent of change can vary across the 

numerous design types of water heaters 

and, perhaps more importantly, within 

a given design type. This variability 

makes it difficult to capture the effect of 

the proposed test procedure 

amendments by a consistent, systematic 

adjustment to the current test 

procedure. 

Foreseeing these circumstances, 

AEMTCA amended EPCA to require that 

along with the uniform descriptor, DOE 

must develop a mathematical 

conversion factor to translate from the 

existing metrics to the uniform 

descriptor. (42 U.S.C. 6295(e)(5)(E)) 

AEMTCA provided that a manufacturer 

may apply the conversion factor to 

rerate existing models of covered water 

heaters that are in existence prior to the 

effective date of the final rule 

establishing the uniform descriptor. 

Further, the conversion factor must not 

affect the minimum efficiency 

requirements for covered water heaters, 

and, as a result, would not lead to a 

change in measured energy efficiency 

for existing products. DOE interprets 

these requirements to mean that DOE 

will be required to translate existing 

ratings from the current metrics to the 

new metric, while maintaining the 

stringency of the current standards. In 

the January 2013 RFI, DOE sought 

comment on the best approach for this 

conversion factor. 78 FR 2340, 2345 

(Jan. 11, 2013). 

NREL stated that there is not a simple 

conversion factor that will work across 

all systems, but it provided a list of 

references with validated algorithms 

that could assist DOE in developing 

these conversion factors. (NREL, No. 29 

at p. 4) AHRI and AO Smith commented 

that DOE should not simply test 

multiple units to determine an average 

difference between the current and new 

ratings and use that value to convert the 

ratings. (AHRI, No. 33 at p. 4; AO Smith, 

No. 34 at p. 3) The joint commenters 

supported the use of a ‘‘good-enough’’ 

mathematical conversion method to 

express existing ratings in terms of the 

new uniform descriptor and urged DOE 

to test a sample of existing products to 

validate the algorithmic conversion 

method. (Joint comment, No. 35 at p. 4) 

Considering the limited laboratory 

capacity to test all water heaters under 

the revised method of test, NEEA 

commented that DOE should assume 

that all water heaters that comply with 

current standards will also comply after 

the implementation of the new metrics. 

(NEEA, No. 37 at p. 6) EEI commented 

that the conversion factor should not 

make currently existing standards more 

stringent and should only be based on 

point-of-use metrics to be consistent 

with Federal law. (EEI, No. 40 at p. 2) 

HTP commented that the most exact 

approach would be to conduct an 

empirical analysis using curve fitting to 

actual test data, although the commenter 

acknowledged that there is not 

sufficient time for manufacturers to 

obtain this information and for the 

Department to then correlate and 

analyze the data. (HTP, No. 41 at p. 3) 

DOE notes these comments regarding 

the conversion factor and will consider 

them fully once the test procedure is 

finalized to assist in developing the 

conversion factor. DOE plans to conduct 

a separate rulemaking to establish the 

conversion factor once the test method 

is finalized, and in that rulemaking, 

DOE will establish a mathematical 

method for determining the rated 

efficiency under the new efficiency 

descriptor from the rated efficiency 

under the existing metrics. Should it 

become apparent in the rulemaking to 

establish the conversion factor that 

changes may be required in the test 

procedure, DOE would address any 

issues at that time. DOE also plans to 

translate its current energy conservation 

standards to equivalent standards 

denominated in the new uniform 

efficiency metric in the separate 

rulemaking. 

I. Other Issues 

DOE also sought comments in the 

October 2011 RFI and the January 2013 

RFI on any other relevant issues that 

commenters believe could affect the test 

procedure for water heaters, and 

continues to seek comment in today’s 

notice. 76 FR 63211, 63215 (Oct. 12, 

2011); 78 FR 2340, 2346 (Jan. 11, 2013). 

Although DOE has attempted to identify 

those portions of the test procedure 

where it believes amendments may be 

warranted, interested parties are 

welcome to provide comments on any 

aspect of the test procedure, including 

updates of referenced standards, as part 

of this comprehensive 7-year-review 

rulemaking. 

AET supported keeping the inlet 

water temperature at 58 °F. (AET, No. 22 

at p. 4) Davis Energy Group provided 

data on average inlet water temperatures 

reported in studies in California that 

ranged from 64.2 °F to 72.3 °F. (Davis 

Energy Group, No. 6 at p. 3) Despite 

these values being higher than the 

current nominal temperature specified 

in the current DOE test procedure, DOE 

has not seen any data that suggests a 

different temperature is more 

appropriate on a national basis, so DOE 

has tentatively decided to maintain the 

inlet temperature at 58 °F in the 

proposed test procedure. 

AHRI suggested an alternative means 

to prepare a storage-type water heater 

prior to commencement of the 24-hour 

simulated-use test. (AHRI, No. 46 at p. 

7) AHRI suggested that DOE could 

improve the consistency of energy factor 

tests by running the draw patterns on 

two consecutive days, with 

measurements only taking place during 

the second 24-hour period. After careful 

consideration, DOE has tentatively 

concluded that this approach would 

lead to more consistent results since the 

state of the water heater at the beginning 

of the 24-hour test period will be similar 

to that at the end of the test period, 

thereby minimizing the need to make 

large corrections to the energy 

consumption values which could 

introduce errors. DOE is aware of testing 

conducted in this manner that has 

resulted in consistent values for the 

energy factor.20 DOE is tentatively 

proposing to require storage water 

heaters to be pre-conditioned in this 

manner. It is DOE’s understanding that 

test laboratories must already let the 

water heater sit at temperature for an 

extended period of time to let the unit 

achieve operational temperature. 

Therefore, DOE reasons that the 

proposed pre-conditioning routine 

might be done during this stage, thereby 

resulting in little or no added test time. 

DOE is interested in comment regarding 

the value of the pre-conditioning period 

and the incremental burden, if any, that 


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it would place on manufacturers. This is 

identified as issue 5 in section V.E, 

‘‘Issues on Which DOE Seeks 

Comment.’’ 

NREL argued that published metrics 

from the DOE test procedure should 

allow for calculation of performance 

under conditions outside the particular 

conditions imposed by the test 

procedure. (NREL, No. 29 at p. 1) DOE 

does not propose to require any 

published metrics from the test 

procedure specifically for the purpose of 

calculating performance at various 

conditions outside of those imposed by 

the test method, as the purpose of the 

DOE test procedure is to determine 

compliance to minimum efficiency 

standards and to provide a basis for 

representation of energy performance to 

consumers. 

The joint comment urged DOE to 

consider several additional points. (Joint 

comment, No. 35 at p. 6) First, it raised 

the question as to the appropriate rating 

method for a hybrid solar water heating 

system whose tank might be passive or 

active. DOE notes that solar water 

heaters are not covered equipment 

under EPCA, and thus the DOE test 

method for water heaters need not 

address these systems. Further, hybrid 

solar water heating systems consisting 

of a stand-alone water heater with 

additional solar components that are 

added in the field could be tested 

according to the rating method provided 

for the water heater if the solar 

components were not present. The 

stand-alone heater would be subject to 

energy conservation standards without 

consideration of the benefits, if any, of 

the solar portion. Second, the joint 

commenters questioned how to rate 

‘‘hybrid’’ fuel-fired units with tanks 

larger than 2 gallons. DOE believes that 

amendments proposed in this NOPR 

will cover those products—the storage 

volume gaps that currently exist in the 

scope would be removed under this 

proposal, and the proposed test method 

would cover those products. Lastly, the 

joint commenters asked whether test 

procedures should reflect energy 

savings from ‘‘smart’’ or ‘‘gridinteractive’’ water heaters. DOE does not 

believe that a separate test procedure is 

warranted for this equipment, because 

they are functionally similar to nongrid-interactive water heaters. DOE 

acknowledges that usage patterns for 

grid-interactive water heaters may be 

very different from water heaters that 

are not grid-interactive or controlled as 

part of demand response programs. 

However, DOE believes that there is 

generally a wide range of usage patterns 

for all water heating products seen in 

the field, and it would be impractical to 

attempt to tailor the test method to 

every potential usage pattern. Thus, 

DOE believes that such differences in 

usage patterns are better addressed as 

part of standards analyses, rather than 

as a separate test method. 

PGE commented that a method is 

needed for reporting source energy 

consumption for future standards 

rulemakings, because the commenter 

opined that source energy is a more 

complete metric for representing the 

energy consumed by appliances and 

would yield a better comparison 

between the energy consumption of gas, 

electric, and gas/electric units. The 

commenter further opined that the test 

procedures should include calculations 

to allow for two energy factors, one 

based on site energy and one based on 

source energy. (PGE, No. 3 at p. 2) In 

response to the January 2013 RFI, DOE 

received additional comments related to 

source-based metrics. EEI stated that, 

consistent with other Federal laws, any 

new descriptor or conversion factor 

should only be based on point-of-use 

metrics. (EEI, No. 40 at p. 2) AGA, 

NPGA, and APGA all supported a 

metric based on the full fuel cycle that 

would provide a complete accounting of 

energy consumption from extraction, 

processing, and transportation of 

energy. (AGA, No. 31, at p. 3; NPGA, 

No. 32 at p. 1; APGA, No. 39 at p. 1) 

In addressing this comment, DOE 

notes that the Department has 

historically presented national energy 

savings (NES) in terms of primary 

energy savings (i.e., source energy 

savings). However, in response to the 

recommendations of a committee on 

‘‘Point-of-Use and Full-Fuel-Cycle 

Measurement Approaches to Energy 

Efficiency Standards’’ appointed by the 

National Academy of Science, DOE 

announced its intention to use full-fuelcycle (FFC) measures of energy use and 

greenhouse gas and other emissions in 

the national impact analyses and 

emissions analyses included in future 

energy conservation standards 

rulemakings. 76 FR 51281(August 18, 

2011). To this end, DOE has begun to 

also estimate energy savings using the 

FFC metric. The FFC metric includes 

the energy consumed in extracting, 

processing, and transporting primary 

fuels, and thus presents a more 

complete picture of the impacts of 

efficiency standards. DOE’s approach is 

based on application of FFC multipliers 

for each fuel type used by covered 

products and equipment, as presented 

in DOE’s statement of policy published 

in the Federal Register on August 18, 

2011. Id. 

DOE has reviewed the water heater 

test procedures, including today’s 

proposed amendments, in relation to the 

newly established FFC policy, and has 

tentatively concluded that no 

substantive amendments are needed to 

the water heater test procedures to 

accommodate the FFC policy. In 

support of this conclusion, the 

following discussion elaborates 

separately on the FFC policy 

implications for energy efficiency 

standards and representations. 

For the purposes of energy 

conservation standards, the test 

procedure-derived measure of energy 

consumption and efficiency, including 

the regulatory efficiency metric (i.e., EF) 

is sufficient and complete enough to 

allow for full consideration of the FFC 

impacts in the energy conservation 

standards analysis. In support of this 

conclusion, it is noted that the existing 

and future energy conservation 

standards for these products are, and are 

expected to continue to be, analyzed 

independently by fuel type. DOE 

believes this independent analytical 

approach eliminates any possible 

mischaracterization or inappropriate 

consideration of a standard’s stringency 

that might be associated with the test 

procedure’s regulatory metrics for these 

products. More specifically, the 

commenters’ suggestion to add a sourcebased Energy Factor for water heaters 

would not add to or improve the 

standards analysis for water heaters 

because of the expansion of the 

standard’s analysis already incorporated 

in the current approach. 

For the purposes of representations, 

DOE has also tentatively concluded that 

some small improvements to the water 

heater test procedure are deemed 

appropriate to accommodate the FFC 

policy. It is important to note that both 

the current test procedure and the 

proposed revised test method for this 

product incorporate numerous measures 

of energy consumption and efficiency, 

some of which are used in the 

regulatory context mentioned above and 

some of which support the consumer 

information objective of the test 

procedure. Although the main thrust of 

the PGE, AGA, APGA, and NPGA 

suggestions seems to be based on the 

assumption that the addition of a 

source-based energy factor would 

improve analysis for water heater 

standards, there also seems to be a 

suggestion that such inclusion would 

also provide improvement in a nonregulatory or consumer information 

context. An important example of a nonregulatory metric is annual energy 

consumption, which provides a 

complete accounting of the energy 

consumption to the consumer and 

which can be used to estimate annual 


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operating cost. For water heaters, DOE 

proposes to add terms in the test 

method to quantify daily electric energy 

consumption separately from fossil fuel 

energy consumption and to add separate 

estimates of annual fossil fuel energy 

consumption and annual electrical 

energy consumption in addition to the 

overall annual energy consumption. 

This separation would allow the user of 

the test procedure to estimate 

operational cost of water heaters that 

use both fossil fuel and electricity based 

on the prices of those different energy 

sources. From a consumer’s perspective, 

annual operating cost is particularly 

useful for the products that have dual 

fuel inputs. DOE believes this consumer 

cost perspective is reasonably reflected 

in the FFC (i.e., the source/site factors 

recommended by the commenter are 

essentially numerically identical to the 

fuel cost ratios published biennially by 

the Secretary). Therefore, the 

commenters’ suggested addition of a 

source-based energy factor using the 

suggested multipliers is, in DOE’s view, 

not likely to convey any improvement 

in product-to-product comparisons 

relative to annual operating cost. In fact, 

annual operating cost would likely be a 

superior basis of comparison for 

consumers, considering the familiarity 

with annual budgets and the lack of 

familiarity with source-based efficiency 

comparisons. 

In addition, and perhaps more 

importantly, annual operating cost 

provides a reasonable comparison 

across competing product types 

utilizing different fuels (e.g., electric 

water heaters and gas-fueled water 

heaters). Arguably, site-based energy 

factors for electric water heaters 

(typically approximately 0.9 for an 

electric resistance model) would be 

higher than the counterpart energy 

factors for gas water heaters (typically 

approximately 0.6), but not 

representative of the relative efficiency 

of each type of water heater. Thus, an 

inappropriate conclusion would be 

conveyed to consumers. DOE believes 

such inappropriate conclusions can be 

easily avoided in any consumer 

information program by focusing on 

annual operating cost. Here again, the 

biennial published unit cost of energy 

would protect the consumer from 

inappropriate conclusions. Accordingly, 

for purposes of representations, DOE is 

not aware, nor has it been made aware 

through responses to the request for 

information, of any specific problems, 

shortcomings, or misrepresentations 

resulting from the existing test 

procedure measures of energy 

consumption and efficiency as it relates 

to the FFC policy. The proposed 

amendments to the water heater test 

procedure would provide additional 

metrics that could be used should one 

desire more information related to the 

FFC policy for a particular application 

of the test method. 

DOE is interested in receiving 

comment on adding terms to quantify 

daily electric energy consumption 

separately from fossil fuel energy 

consumption and adding separate 

estimates of annual fossil fuel energy 

consumption and annual electrical 

energy consumption in addition to the 

overall annual energy consumption. 

This is identified as issue 8 in section 

V.E, ‘‘Issues on Which DOE Seeks 

Comment.’’ 

A final issue raised by commenters is 

that heat pump water heaters that have 

recently entered the market typically 

have multiple operational modes, and 

the current DOE test procedure does not 

specify which mode should be used 

when the unit is undergoing testing. AO 

Smith and AHRI commented that all 

heat pump water heaters should be 

tested under a single mode of operation 

which is the default or ‘‘out-of-the-box’’ 

condition. (AO Smith, No. 8 at p. 2; 

AHRI No. 12 at p. 3) DOE agrees with 

this comment and proposes a 

clarification to the test procedure to 

indicate that heat pump water heaters 

are to be tested in the default mode 

when obtaining both the first-hour 

rating and determining the energy 

factor. This clarification is consistent 

with guidance issued by DOE on June 

12, 2012 (see: http://www1.eere.energy.

gov/guidance/detail_search.aspx?ID

Question=623&pid=2&spid=1). 

J. Certification, Compliance, and 

Enforcement Issues 

In this notice of proposed rulemaking, 

DOE proposes to make several changes 

to its certification, compliance, and 

enforcement regulations at 10 CFR Part 

429. First, DOE proposes to add 

requirements to 10 CFR 429.17 that the 

rated value of storage tank volume must 

equal the mean of the measured storage 

volume of the units in the sample. DOE 

notes that there are currently no 

requirements from the Department 

limiting the amount of difference that is 

allowable between the tested (i.e., 

measured) storage volume and the 

‘‘rated’’ storage volume that is specified 

by the manufacturer. DOE has tested 65 

residential storage-type water heaters, 

including 44 gas-fired water heaters, 19 

electric water heaters, and 2 oil-fired 

water heaters. Through this testing, DOE 

has found that water heaters are 

consistently rated at storage volumes 

above their actual storage volume. For 

gas fired water heaters, the rated volume 

ranged from 1.5 to 15.6 percent above 

the measured volume, with the mean 

being 4.8 percent. For electric water 

heaters, the rated volume ranged from 

5.0 to 10.6 percent above the measured 

volume, with the mean being 9.4 

percent. DOE notes that its minimum 

energy conservation standards are based 

on the rated storage volume and 

decrease as rated storage volume 

increases. DOE also believes consumers 

often look to storage volume as a key 

factor in choosing a storage water 

heater. Consequently, DOE proposes to 

adopt rating requirements that the rated 

value must be the mean of the measured 

value. In addition, DOE proposes to 

specify that for DOE-initiated testing, a 

tested value within five percent of the 

rated value would be a valid test result 

where the rated storage volume would 

then be used in downstream 

calculations. If the test result of the 

volume is invalid (i.e., the measured 

value is more than five percent different 

than the rated value), then DOE 

proposes to use the measured value in 

determining the applicable minimum 

energy conservation standard and 

calculations within the test procedure. 

DOE proposes to specify similar 

requirements for light commercial water 

heaters. 

Additionally, because the first-hour 

and maximum gpm ratings will 

determine the applicable draw pattern 

for use during the energy factor test, 

DOE proposes to include rating 

requirements for those values. DOE 

proposes that the rated first-hour rating 

or maximum gpm rating, as applicable, 

must be the mean of the measured 

values of the sample used for certifying 

the basic model’s efficiency rating. For 

DOE testing, the rating will be 

considered valid if it is within five 

percent of the certified rating. In such a 

case, DOE proposes that the rated value 

would be used for the purposes of 

choosing the appropriate draw pattern 

for the energy factor test. In the case of 

an invalid rating (i.e., the rated firsthour rating or maximum gpm rating is 

more than five percent different from 

the measured value), DOE proposes to 

use the measured value to determine the 

applicable draw pattern for the energy 

factor test. 

DOE has further considered section 

7.0 of the current test procedure, 

‘‘Ratings for Untested Models,’’ and 

believes that this information is more 

appropriately addressed in the 10 CFR 

part 429, which deals with requirements 

for certification of residential water 

heaters. DOE proposes to remove this 

section from Appendix E and place a 

similar section in 10 CFR 429.17. DOE 


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proposes to maintain the requirements 

for gas water heaters, which allow units 

using propane gas that have an input 

rating within 10 percent of an identical 

natural gas unit to use the rating for the 

natural gas unit in lieu of separate 

testing. However, DOE proposes to 

eliminate the provisions for electric 

water heaters that currently allow a 

manufacturer of electric water heaters 

that are identical except with different 

input ratings to designate a standard 

input rating at which to test the water 

heater. 

Under the current procedure, the 

manufacturer of electric water heaters 

may designate the standard input rating 

that would apply to all models that are 

identical with the exception of the 

power input to the heating element and 

test only at single input rating. It 

provides instructions for specifying the 

first-hour rating of units with higher and 

lower input ratings than the standard 

rating. The procedure also provides that 

the energy factor can be assumed to be 

the same across all input ratings. DOE 

proposes to remove these provisions 

due to the proposed revisions in the test 

method for the first-hour rating and 

energy factor tests. The first-hour rating 

would be expected to vary based on the 

power input to the electric heating 

element, and under the revisions 

proposed in this test method the 

applicable draw pattern for the energy 

factor test would be based on the firsthour rating. As a result, it is important 

that the first-hour rating is accurate for 

the given model as it will potentially 

impact the draw pattern and the 

resultant EF rating. 

K. Reference Standards 

DOE’s test procedure for residential 

water heaters currently references two 

industry standards: American Society 

for Testing and Measurement (ASTM) 

D2156–80, ‘‘Smoke Density in Flue 

Gases from Burning Distillate Fuels, 

Test Method for’’ and ASHRAE 

Standard 41.1–1986, ‘‘Standard 

Measurement Guide: Section on 

Temperature Measurements.’’ 

DOE proposes to maintain these 

references in the uniform efficiency 

descriptor test method, but to update 

the reference standards to the most 

recent versions of the industry 

standards: ASTM D2156–09, ‘‘Standard 

Test Method for Smoke Density in Flue 

Gases from Burning Distillate Fuels’’ 

and ASHRAE Standard 41.1–1986 

(RA2006), ‘‘Standard Method for 

Temperature Measurement.’’ DOE has 

reviewed both of the updated standards 

and has tentatively concluded that their 

adoption would not substantially 

impact the test method. 

L. Compliance With Other EPCA 

Requirements 

As mentioned above, in amending a 

test procedure, EPCA directs DOE to 

determine to what extent, if any, the test 

procedure would alter the measured 

energy efficiency or measured energy 

use of a covered product. (42 U.S.C. 

6293(e)(1)) If the amended test 

procedure alters the measured energy 

efficiency or measured energy use, the 

Secretary must amend the applicable 

energy conservation standard to the 

extent the amended test procedure 

changes the energy efficiency of 

products that minimally comply with 

the existing standard. (42 U.S.C. 

6293(e)(2)) The current energy 

conservation standards for residential 

water heaters are based on energy factor 

(EF), and the energy conservation 

standards for commercial water heaters 

are based on thermal efficiency and 

standby loss. DOE believes that the 

conversion factor (or factors) required 

by AEMTCA (as discussed in section 

III.G) will ensure that there is no change 

in measured energy efficiency. 

Consistent with 42 U.S.C. 6293(c), 

DOE typically requires that any 

representations of energy consumption 

of covered products must be based on 

any final amended test procedures 180 

days after the publication of the test 

procedure final rule. However, in this 

instance, the statute specifically 

provides for an effective date of the test 

procedure final rule which is one year 

after the date of the publication of the 

final rule. (42 U.S.C. 6295(e)(5)(D)(ii)) In 

addition, AEMTCA provides for the use 

of a conversion factor that will apply 

beginning on the date of publication of 

the conversion factor in the Federal 

Register and ending on the later of 1 

year after the date of publication of the 

conversion factor or December 31, 2015. 

(42 U.S.C. 6295(e)(5)(E)(v)) Thus, one 

year after the publication of the test 

procedure final rule, it will become 

effective, and manufacturers may at 

their discretion make representations of 

energy efficiency based either (a) on the 

final amended test procedures or (b) on 

the previous test procedures after 

applying the conversion factor. The 

previous test procedures for residential 

water heaters are set forth at 10 CFR part 

430, subpart B, appendix E as contained 

in 10 CFR parts 200 to 499 edition 

revised as of January 1, 2013. The 

previous test procedures for commercial 

water heating equipment are set forth at 

10 CFR 431.106 as contained in 10 CFR 

parts 200 to 499 edition revised as of 

January 1, 2013. As required by 

AEMTCA, the conversion factor may be 

used until the later of one year after the 

publication of the factor, or December 

31, 2015, after which time all testing 

must be conducted in accordance with 

the new amended test procedure. DOE 

notes that during the interim period 

manufacturers must use the same test 

procedure for representations of energy 

efficiency, including certifications of 

compliance. 

IV. Procedural Issues and Regulatory 

Review 

A. Review Under Executive Order 12866 

The Office of Management and Budget 

has determined that test procedure 

rulemakings do not constitute 

‘‘significant regulatory actions’’ under 

section 3(f) of Executive Order 12866, 

‘‘Regulatory Planning and Review,’’ 58 

FR 51735 (Oct. 4, 1993). Accordingly, 

this regulatory action was not subject to 

review under the Executive Order by the 

Office of Information and Regulatory 

Affairs (OIRA) in the Office of 

Management and Budget (OMB). 

B. Review Under the Regulatory 

Flexibility Act 

The Regulatory Flexibility Act (5 

U.S.C. 601 et seq., as amended by the 

Small Business Regulatory Enforcement 

Fairness Act of 1996) requires 

preparation of an initial regulatory 

flexibility analysis (IFRA) for any rule 

that by law must be proposed for public 

comment and a final regulatory 

flexibility analysis (FRFA) for any such 

rule that an agency adopts as a final 

rule, unless the agency certifies that the 

rule, if promulgated, will not have a 

significant economic impact on a 

substantial number of small entities. A 

regulatory flexibility analysis examines 

the impact of the rule on small entities 

and considers alternative ways of 

reducing negative effects. Also, as 

required by Executive Order 13272, 

‘‘Proper Consideration of Small Entities 

in Agency Rulemaking,’’ 67 FR 53461 

(August 16, 2002), DOE published 

procedures and policies on February 19, 

2003, to ensure that the potential 

impacts of its rules on small entities are 

properly considered during the DOE 

rulemaking process. 68 FR 7990. DOE 

has made its procedures and policies 

available on the Office of the General 

Counsel’s Web site at: www.gc.doe.gov/ 

gc/office-general-counsel. 

Today’s proposed rule would 

prescribe test procedure amendments 

that would be used to determine 

compliance with energy conservation 

standards for residential water heaters 

and certain commercial water heaters. 

For residential water heaters and certain 

commercial water heaters, the proposed 

amendments would establish a uniform 


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efficiency descriptor which would be 

more representative of conditions 

encountered in the field (including 

modifications to both the test conditions 

and the draw patterns), and expand the 

scope of the test procedure to apply to 

certain residential water heaters and 

certain commercial water heaters that 

are currently not covered by the test 

procedure. DOE reviewed today’s 

proposed rule under the provisions of 

the Regulatory Flexibility Act and the 

policies and procedures published on 

February 19, 2003. 68 FR 7990. 

For the manufacturers of the covered 

water heater products, the Small 

Business Administration (SBA) has set a 

size threshold, which defines those 

entities classified as ‘‘small businesses’’ 

for the purposes of the statute. DOE 

used the SBA’s small business size 

standards to determine whether any 

small entities would be subject to the 

requirements of the rule. 65 FR 30836, 

30848–49 (May 15, 2000), as amended at 

65 FR 53533, 53544–45 (Sept. 5, 2000) 

and codified at 13 CFR part 121. The 

size standards are listed by North 

American Industry Classification 

System (NAICS) code and industry 

description and are available at http:// 

www.sba.gov/idc/groups/public/

documents/sba_homepage/serv_sstd_

tablepdf.pdf. Residential water heater 

manufacturing is classified under 

NAICS 335228—‘‘Other Major 

Household Appliance Manufacturing.’’ 

The SBA sets a threshold of 500 

employees or less for an entity to be 

considered as a small business. 

Commercial water heaters are classified 

under NAICS 333319 –‘‘Other 

Commercial and Service Industry 

Machinery Manufacturing,’’ for which 

SBA also sets a size threshold of 500 

employees or fewer for being considered 

a small business. 

DOE has identified 13 manufacturers 

of residential water heaters (including 

manufacturers of products that fall 

under the proposed expanded scope) 

that can be considered small businesses. 

DOE identified nine manufacturers of 

‘‘light commercial’’ water heaters that 

can be considered small businesses. 

Seven of the ‘‘light commercial’’ water 

heater manufacturers also manufacture 

residential water heaters, so the total 

number of water heater manufacturers 

impacted by this rule would be 15. 

DOE’s research involved reviewing 

several industry trade association 

membership directories (e.g., AHRI), 

product databases (e.g., AHRI, CEC, and 

ENERGY STAR databases), individual 

company Web sites, and marketing 

research tools (e.g., Hoovers reports) to 

create a list of all domestic small 

business manufacturers of products 

covered by this rulemaking. 

For the reasons explained below, DOE 

has tentatively concluded that the test 

procedure amendments contained in 

this proposed rule would not have a 

significant economic impact on any 

manufacturer, including small 

manufacturers. 

For residential water heaters, the 

amendments proposed in today’s notice 

of proposed rulemaking apply primarily 

to the draw pattern and water delivery 

temperature. Under DOE’s existing test 

procedure, manufacturers must perform 

a simulated use test consisting of 6 

draws of equal lengths with a water 

heater delivery temperature of 135 °F. If 

adopted, today’s proposal would require 

manufacturers to perform a simulated 

use test consisting of 9 to 14 draws of 

varied length, depending on the 

capacity of the water heater, at a water 

delivery temperature of 125 °F. The 

change in water delivery temperature 

requires no additional effort or expense 

for the manufacturer, because 

establishing the test temperature is 

simply a matter of choosing the 

appropriate setting on the water heater. 

Likewise, the change in the number of 

draws would also result in very little 

burden on manufacturers. The length 

and timing of draws for the existing test 

procedure are largely controlled 

automatically by computer control. The 

proposed changes would result in 

manufacturers having to reprogram the 

computer test programs to account for 

the new draw patterns. DOE estimates 

that this effort would take 

approximately one week to program and 

confirm operation of the amended test. 

It is estimated that approximately two 

days of a programmer’s time would be 

needed at a cost of $1,000 including 

overhead and benefits. This one-time 

cost is comparable to that charged by a 

third-party test laboratory for a single 

test, so it is not considered burdensome 

for water heater manufacturers. Since 

the simulated use test takes 24 hours 

under both the existing and proposed 

test method, the length of the test would 

not change. The current proposal does 

specify a 24-hour pre-conditioning 

period prior to the 24-hour test for 

storage water heaters, however, which 

would add to the time required to 

conduct the test. This extra test time 

would not require extra personnel, but 

it may necessitate the development of 

additional test platforms to 

accommodate the amount of testing that 

a manufacturer must conduct. A 

duplicate test platform, if necessary, 

could result in an additional cost of 

approximately $5,000 in terms of 

materials and time needed for 

construction. DOE understands, 

however, that a 24-hour preconditioning period is already 

implemented by manufacturers as a best 

practice to allow the water heater to 

achieve operational temperature, so the 

added burden would be minimal. In 

addition, these tests can be conducted 

in the same facilities used for the 

current energy testing of these products, 

so there would be no additional facility 

costs required by the proposed rule. 

Lastly, the only potential 

instrumentation upgrade required to 

conduct the test would be electric 

power and energy measuring equipment 

that meets the accuracy levels that have 

changed from ± 1 percent to ± 0.5 

percent. DOE believes that equipment 

meeting these tolerances is already the 

industry standard. Purchase of a new 

instrument, if needed, would be 

expected to cost approximately $1,000. 

For certain commercial water heaters 

included in the scope of this 

rulemaking, the efficiency test required 

for equipment would change from the 

thermal efficiency and standby loss tests 

specified in the current DOE test 

method, to the simulated use test for 

energy factor proposed in today’s NOPR. 

The energy factor test is inherently more 

complex than the thermal efficiency and 

standby loss tests, and, thus, it may be 

more difficult to implement. However, 

the standby loss test takes a significant 

amount of time, which is comparable to 

the 24-hour simulated use test. 

Accordingly, overall testing time should 

remain fairly constant. DOE 

understands that the complexity of the 

energy factor test would impose 

additional costs on manufacturers due 

to the need to automate draw patterns, 

as compared to the thermal efficiency 

test. In addition, some hardware 

purchases may be needed to allow for 

computer-controlled draws of hot water 

that are required in a simulated use test. 

However, DOE notes that many 

commercial water heater manufacturers 

also manufacture residential water 

heaters, and may already have this 

equipment from testing of residential 

units. Nonetheless, DOE estimates that 

this hardware could cost approximately 

$1,000, assuming that the laboratory 

already has a computer-controlled data 

acquisition system to collect data during 

the thermal efficiency and standby loss 

tests currently required. DOE estimates 

the costs for a programmer to create a 

computer program that automatically 

controls the hot water draws would be 

similar to the costs above, but that the 

time required may be slightly longer if 

the program is being developed from 

scratch. Under such circumstances, DOE 

estimates that 5 days of programmer 


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time would be needed for a cost of 

$2,500, including overhead and 

benefits. 

Lastly, DOE considered the impacts 

on small businesses that manufacture 

residential water heaters that fall into 

categories that were previously not 

covered by the DOE residential water 

heater test procedure (e.g., models with 

storage volumes between 2 and 20 

gallons). In reviewing the market for 

these products, DOE did not identify 

any manufacturers that did not also 

manufacture other types of water 

heating equipment. Thus, DOE believes 

that these manufacturers would already 

have the needed equipment and 

computer programs to conduct the 

current DOE test. For the reasons stated 

previously, DOE does not believe the 

proposed updates will cause significant 

additional burdens for these 

manufacturers. 

Accordingly, DOE tentatively 

concludes and certifies that this 

proposed rule would not have a 

significant economic impact on a 

substantial number of small entities, so 

DOE has not prepared a regulatory 

flexibility analysis for this rulemaking. 

DOE will provide its certification and 

supporting statement of factual basis to 

the Chief Counsel for Advocacy of the 

SBA for review under 5 U.S.C. 605(b). 

C. Review Under the Paperwork 

Reduction Act of 1995 

Manufacturers of water heaters must 

certify to DOE that their products 

comply with all applicable energy 

conservation standards. In certifying 

compliance, manufacturers must test 

their products according to the DOE test 

procedure for water heaters, including 

any amendments adopted for the test 

procedure on the date that compliance 

is required. DOE has established 

regulations for the certification and 

recordkeeping requirements for all 

covered consumer products and 

commercial equipment, including 

residential and commercial water 

heaters. (76 FR 12422 (March 7, 2011). 

The collection-of-information 

requirement for certification and 

recordkeeping is subject to review and 

approval by OMB under the Paperwork 

Reduction Act (PRA). This requirement 

has been approved by OMB under OMB 

control number 1910–1400. Public 

reporting burden for the certification is 

estimated to average 20 hours per 

response, including the time for 

reviewing instructions, searching 

existing data sources, gathering and 

maintaining the data needed, and 

completing and reviewing the collection 

of information. 

Notwithstanding any other provision 

of the law, no person is required to 

respond to, nor shall any person be 

subject to a penalty for failure to comply 

with, a collection of information subject 

to the requirements of the PRA, unless 

that collection of information displays a 

currently valid OMB Control Number. 

D. Review Under the National 

Environmental Policy Act of 1969 

In this proposed rule, DOE proposes 

test procedure amendments that it 

expects will be used to develop and 

implement future energy conservation 

standards for residential and 

commercial water heaters. DOE has 

determined that this rule falls into a 

class of actions that are categorically 

excluded from review under the 

National Environmental Policy Act of 

1969 (42 U.S.C. 4321 et seq.) and DOE’s 

implementing regulations at 10 CFR part 

1021. Specifically, this proposed rule 

would amend the existing test 

procedures without affecting the 

amount, quality, or distribution of 

energy usage, and, therefore, would not 

result in any environmental impacts. 

Thus, this rulemaking is covered by 

Categorical Exclusion A5 under 10 CFR 

part 1021, subpart D, which applies to 

any rulemaking that interprets or 

amends an existing rule without 

changing the environmental effect of 

that rule. Accordingly, neither an 

environmental assessment nor an 

environmental impact statement is 

required. 

E. Review Under Executive Order 13132 

Executive Order 13132, ‘‘Federalism,’’ 

64 FR 43255 (August 10, 1999), imposes 

certain requirements on Federal 

agencies formulating and implementing 

policies or regulations that preempt 

State law or that have Federalism 

implications. The Executive Order 

requires agencies to examine the 

constitutional and statutory authority 

supporting any action that would limit 

the policymaking discretion of the 

States, and to carefully assess the 

necessity for such actions. The 

Executive Order also requires agencies 

to have an accountable process to 

ensure meaningful and timely input by 

State and local officials in the 

development of regulatory policies that 

have Federalism implications. On 

March 14, 2000, DOE published a 

statement of policy describing the 

intergovernmental consultation process 

it will follow in the development of 

such regulations. 65 FR 13735. DOE has 

examined this proposed rule and has 

tentatively determined that it would not 

have a substantial direct effect on the 

States, on the relationship between the 

national government and the States, or 

on the distribution of power and 

responsibilities among the various 

levels of government. EPCA governs and 

prescribes Federal preemption of State 

regulations as to energy conservation for 

the products that are the subject of 

today’s proposed rule. States can 

petition DOE for exemption from such 

preemption to the extent, and based on 

criteria, set forth in EPCA. (42 U.S.C. 

6297(d)) No further action is required by 

Executive Order 13132. 

F. Review Under Executive Order 12988 

Regarding the review of existing 

regulations and the promulgation of 

new regulations, section 3(a) of 

Executive Order 12988, ‘‘Civil Justice 

Reform,’’ 61 FR 4729 (Feb. 7, 1996), 

imposes on Federal agencies the general 

duty to adhere to the following 

requirements: (1) Eliminate drafting 

errors and ambiguity; (2) write 

regulations to minimize litigation; (3) 

provide a clear legal standard for 

affected conduct rather than a general 

standard; and (4) promote simplification 

and burden reduction. Regarding the 

review required by section 3(a), section 

3(b) of Executive Order 12988 

specifically requires that Executive 

agencies make every reasonable effort to 

ensure that the regulation: (1) Clearly 

specifies the preemptive effect, if any; 

(2) clearly specifies any effect on 

existing Federal law or regulation; (3) 

provides a clear legal standard for 

affected conduct while promoting 

simplification and burden reduction; (4) 

specifies the retroactive effect, if any; (5) 

adequately defines key terms; and (6) 

addresses other important issues 

affecting clarity and general 

draftsmanship under any guidelines 

issued by the Attorney General. Section 

3(c) of Executive Order 12988 requires 

Executive agencies to review regulations 

in light of applicable standards in 

sections 3(a) and 3(b) to determine 

whether they are met or it is 

unreasonable to meet one or more of 

them. DOE has completed the required 

review and tentatively determined that, 

to the extent permitted by law, the 

proposed rule meets the relevant 

standards of Executive Order 12988. 

G. Review Under the Unfunded 

Mandates Reform Act of 1995 

Title II of the Unfunded Mandates 

Reform Act of 1995 (UMRA) requires 

each Federal agency to assess the effects 

of Federal regulatory actions on State, 

local, and Tribal governments and the 

private sector. Public Law 104–4, sec. 

201 (codified at 2 U.S.C. 1531). For 

regulatory actions likely to result in a 

rule that may cause the expenditure by 


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State, local, and Tribal governments, in 

the aggregate, or by the private sector of 

$100 million or more in any one year 

(adjusted annually for inflation), section 

202 of UMRA requires a Federal agency 

to publish a written statement that 

estimates the resulting costs, benefits, 

and other effects on the national 

economy. (2 U.S.C. 1532(a), (b)) The 

UMRA also requires a Federal agency to 

develop an effective process to permit 

timely input by elected officers of State, 

local, and Tribal governments on a 

‘‘significant intergovernmental 

mandate,’’ and requires an agency plan 

for giving notice and opportunity for 

timely input to potentially affected 

small governments before establishing 

any requirements that might 

significantly or uniquely affect them. On 

March 18, 1997, DOE published a 

statement of policy on its process for 

intergovernmental consultation under 

UMRA. 62 FR 12820. (This policy is 

also available at www.gc.doe.gov/gc/ 

office-general-counsel.) DOE examined 

today’s proposed rule according to 

UMRA and its statement of policy and 

has tentatively determined that the rule 

contains neither an intergovernmental 

mandate, nor a mandate that may result 

in the expenditure by State, local, and 

Tribal governments, in the aggregate, or 

by the private sector, of $100 million or 

more in any year. Accordingly, no 

further assessment or analysis is 

required under UMRA. 

H. Review Under the Treasury and 

General Government Appropriations 

Act, 1999 

Section 654 of the Treasury and 

General Government Appropriations 

Act, 1999 (Pub. L. 105–277) requires 

Federal agencies to issue a Family 

Policymaking Assessment for any rule 

that may affect family well-being. This 

rule would not have any impact on the 

autonomy or integrity of the family as 

an institution. Accordingly, DOE has 

concluded that it is not necessary to 

prepare a Family Policymaking 

Assessment. 

I. Review Under Executive Order 12630 

Pursuant to Executive Order 12630, 

‘‘Governmental Actions and Interference 

with Constitutionally Protected Property 

Rights,’’ 53 FR 8859 (March 18, 1988), 

DOE has determined that this proposed 

rule would not result in any takings that 

might require compensation under the 

Fifth Amendment to the U.S. 

Constitution. 

J. Review Under Treasury and General 

Government Appropriations Act, 2001 

Section 515 of the Treasury and 

General Government Appropriations 

Act, 2001 (44 U.S.C. 3516 note) provides 

for Federal agencies to review most 

disseminations of information to the 

public under information quality 

guidelines established by each agency 

pursuant to general guidelines issued by 

OMB. OMB’s guidelines were published 

at 67 FR 8452 (Feb. 22, 2002), and 

DOE’s guidelines were published at 67 

FR 62446 (Oct. 7, 2002). DOE has 

reviewed today’s proposed rule under 

the OMB and DOE guidelines and has 

concluded that it is consistent with 

applicable policies in those guidelines. 

K. Review Under Executive Order 13211 

Executive Order 13211, ‘‘Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use,’’ 66 FR 28355 (May 

22, 2001), requires Federal agencies to 

prepare and submit to OIRA at OMB, a 

Statement of Energy Effects for any 

significant energy action. A ‘‘significant 

energy action’’ is defined as any action 

by an agency that promulgates or is 

expected to lead to promulgation of a 

final rule, and that: (1) Is a significant 

regulatory action under Executive Order 

12866, or any successor order; and (2) 

is likely to have a significant adverse 

effect on the supply, distribution, or use 

of energy; or (3) is designated by the 

Administrator of OIRA as a significant 

energy action. For any proposed 

significant energy action, the agency 

must give a detailed statement of any 

adverse effects on energy supply, 

distribution, or use should the proposal 

be implemented, and of reasonable 

alternatives to the action and their 

expected benefits on energy supply, 

distribution, and use. 

Today’s regulatory action to amend 

the test procedures for measuring the 

energy efficiency of residential water 

heaters and certain commercial water 

heaters is not a significant regulatory 

action under Executive Order 12866 or 

any successor order. Moreover, it would 

not have a significant adverse effect on 

the supply, distribution, or use of 

energy, nor has it been designated as a 

significant energy action by the 

Administrator of OIRA. Therefore, it is 

not a significant energy action, and, 

accordingly, DOE has not prepared a 

Statement of Energy Effects for this 

rulemaking. 

L. Review Under Section 32 of the 

Federal Energy Administration Act of 

1974 

Under section 301 of the Department 

of Energy Organization Act (Pub. L. 95– 

91; 42 U.S.C. 7101 et seq.), DOE must 

comply with all laws applicable to the 

former Federal Energy Administration, 

including section 32 of the Federal 

Energy Administration Act of 1974 

(Pub. L. 93–275), as amended by the 

Federal Energy Administration 

Authorization Act of 1977 (Pub. L. 95– 

70). (15 U.S.C. 788; FEAA) Section 32 

essentially provides in relevant part 

that, where a proposed rule authorizes 

or requires use of commercial standards, 

the notice of proposed rulemaking must 

inform the public of the use and 

background of such standards. In 

addition, section 32(c) requires DOE to 

consult with the Attorney General and 

the Chairman of the Federal Trade 

Commission (FTC) concerning the 

impact of the commercial or industry 

standards on competition. 

Today’s proposed rule would 

incorporate testing methods contained 

in the following commercial standards: 

(1) ASTM D2156–09, ‘‘Standard Test 

Method for Smoke Density in Flue 

Gases from Burning Distillate Fuels’’; 

and (2) ASHRAE Standard 41.1–1986 

(RA 2006), ‘‘Standard Method for 

Temperature Measurement.’’ While 

today’s proposed test procedure is not 

exclusively based on these standards, 

components of the test procedures are 

adopted directly from these standards 

without amendment. The Department 

has evaluated these standards and is 

unable to conclude whether they fully 

comply with the requirements of section 

32(b) of the FEAA, (i.e., that they were 

developed in a manner that fully 

provides for public participation, 

comment, and review). DOE will 

consult with the Attorney General and 

the Chairman of the FTC concerning the 

impact on competition of requiring 

manufacturers to use the test methods 

contained in these standards prior to 

prescribing a final rule. 

V. Public Participation 

A. Attendance at the Public Meeting 

The time, date and location of the 

public meeting are listed in the DATES

and ADDRESSES sections at the beginning 

of this document. If you plan to attend 

the public meeting, please notify Ms. 

Brenda Edwards at (202) 586–2945 or 

Brenda.Edwards@ee.doe.gov. As 

explained in the ADDRESSES section, 

foreign nationals visiting DOE 

Headquarters are subject to advance 

security screening procedures. Any 

foreign national wishing to participate 

in the meeting should advise DOE of 

this fact as soon as possible by 

contacting Ms. Brenda Edwards to 

initiate the necessary procedures. 

In addition, you can attend the public 

meeting via webinar. Webinar 

registration information, participant 

instructions, and information about the 

capabilities available to webinar 


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participants will be published on DOE’s 

Web site at: http:// 

www1.eere.energy.gov/buildings/ 

appliance_ standards/ 

rulemaking.aspx?ruleid=82. Participants 

are responsible for ensuring their 

systems are compatible with the 

webinar software. 

B. Procedure for Submitting Requests To 

Speak and Prepared General Statements 

for Distribution 

Any person who has an interest in the 

topics addressed in this notice, or who 

is representative of a group or class of 

persons that has an interest in these 

issues, may request an opportunity to 

make an oral presentation at the public 

meeting. Such persons may handdeliver requests to speak to the address 

shown in the ADDRESSES section at the 

beginning of this notice of proposed 

rulemakiing between 9:00 a.m. and 4:00 

p.m., Monday through Friday, except 

Federal holidays. Requests may also be 

sent by mail or email to Ms. Brenda 

Edwards, U.S. Department of Energy, 

Building Technologies Office, Mailstop 

EE–2J, 1000 Independence Avenue SW., 

Washington, DC 20585–0121, or 

Brenda.Edwards@ee.doe.gov. Persons 

who wish to speak should include in 

their request a computer diskette or CD– 

ROM in WordPerfect, Microsoft Word, 

PDF, or text (ASCII) file format that 

briefly describes the nature of their 

interest in this rulemaking and the 

topics they wish to discuss. Such 

persons should also provide a daytime 

telephone number where they can be 

reached. 

DOE requests persons selected to 

make an oral presentation to submit an 

advance copy of their statements at least 

one week before the public meeting. 

DOE may permit persons who cannot 

supply an advance copy of their 

statement to participate, if those persons 

have made advance alternative 

arrangements with the Building 

Technologies Office. As necessary, 

requests to give an oral presentation 

should ask for such alternative 

arrangements. 

Any person who has plans to present 

a prepared general statement may 

request that copies of his or her 

statement be made available at the 

public meeting. Such persons may 

submit requests, along with an advance 

electronic copy of their statement in 

PDF (preferred), Microsoft Word or 

Excel, WordPerfect, or text (ASCII) file 

format, to the appropriate address 

shown in the ADDRESSES section at the 

beginning of this notice of proposed 

rulemaking. The request and advance 

copy of statements must be received at 

least one week before the public 

meeting and may be emailed, handdelivered, or sent by mail. DOE prefers 

to receive requests and advance copies 

via email. Please include a telephone 

number to enable DOE staff to make 

follow-up contact, if needed. 

C. Conduct of the Public Meeting 

DOE will designate a DOE official to 

preside at the public meeting and may 

also use a professional facilitator to aid 

discussion. The meeting will not be a 

judicial or evidentiary-type public 

hearing, but DOE will conduct it in 

accordance with section 336 of EPCA 

(42 U.S.C. 6306). A court reporter will 

be present to record the proceedings and 

prepare a transcript. DOE reserves the 

right to schedule the order of 

presentations and to establish the 

procedures governing the conduct of the 

public meeting. There shall not be 

discussion of proprietary information, 

costs or prices, market share, or other 

commercial matters regulated by U.S. 

anti-trust laws. After the public meeting, 

interested parties may submit further 

comments on the proceedings, as well 

as on any aspect of the rulemaking, until 

the end of the comment period. 

The public meeting will be conducted 

in an informal, conference style. DOE 

will present summaries of comments 

received before the public meeting, 

allow time for prepared general 

statements by participants, and 

encourage all interested parties to share 

their views on issues affecting this 

rulemaking. Each participant will be 

allowed to make a general statement 

(within time limits determined by DOE), 

before the discussion of specific topics. 

DOE will allow, as time permits, other 

participants to comment briefly on any 

general statements. 

At the end of all prepared statements 

on a topic, DOE will permit participants 

to clarify their statements briefly and 

comment on statements made by others. 

Participants should be prepared to 

answer questions by DOE and by other 

participants concerning these issues. 

DOE representatives may also ask 

questions of participants concerning 

other matters relevant to this 

rulemaking. The official conducting the 

public meeting will accept additional 

comments or questions from those 

attending, as time permits. The 

presiding official will announce any 

further procedural rules or modification 

of the above procedures that may be 

needed for the proper conduct of the 

public meeting. 

A transcript of the public meeting will 

be included in the docket, which can be 

viewed as described in the Docket 

section at the beginning of this notice of 

the proposed rulemaking, and will be 

accessible on the DOE Web site. In 

addition, any person may buy a copy of 

the transcript from the transcribing 

reporter. 

D. Submission of Comments 

DOE will accept comments, data, and 

information regarding this proposed 

rule before or after the public meeting, 

but no later than the date provided in 

the DATES section at the beginning of 

this proposed rule. Interested parties 

may submit comments using any of the 

methods described in the ADDRESSES

section at the beginning of this notice of 

proposed rulemaking. 

Submitting comments via 

regulations.gov. The 

www.regulations.gov Web page will 

require you to provide your name and 

contact information. Your contact 

information will be viewable to DOE 

Building Technologies staff only. Your 

contact information will not be publicly 

viewable except for your first and last 

names, organization name (if any), and 

submitter representative name (if any). 

If your comment is not processed 

properly because of technical 

difficulties, DOE will use this 

information to contact you. If DOE 

cannot read your comment due to 

technical difficulties and cannot contact 

you for clarification, DOE may not be 

able to consider your comment. 

However, your contact information 

will be publicly viewable if you include 

it in the comment itself or in any 

documents attached to your comment. 

Any information that you do not want 

to be publicly viewable should not be 

included in your comment, nor in any 

document attached to your comment. 

Otherwise, persons viewing comments 

will see only first and last names, 

organization names, correspondence 

containing comments, and any 

documents submitted with the 

comments. 

Do not submit to www.regulations.gov 

information for which disclosure is 

restricted by statute, such as trade 

secrets and commercial or financial 

information (hereinafter referred to as 

Confidential Business Information 

(CBI)). Comments submitted through 

www.regulations.gov cannot be claimed 

as CBI. Comments received through the 

Web site will waive any CBI claims for 

the information submitted. For 

information on submitting CBI, see the 

Confidential Business Information 

section. 

DOE processes submissions made 

through www.regulations.gov before 

posting. Normally, comments will be 

posted within a few days of being 

submitted. However, if large volumes of 

comments are being processed 


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simultaneously, your comment may not 

be viewable for up to several weeks. 

Please keep the comment tracking 

number that www.regulations.gov 

provides after you have successfully 

uploaded your comment. 

Submitting comments via email, hand 

delivery/ courier, or mail. Comments 

and documents submitted via email, 

hand delivery/ courier, or mail also will 

be posted to www.regulations.gov. If you 

do not want your personal contact 

information to be publicly viewable, do 

not include it in your comment or any 

accompanying documents. Instead, 

provide your contact information in a 

cover letter. Include your first and last 

names, email address, telephone 

number, and optional mailing address. 

The cover letter will not be publicly 

viewable as long as it does not include 

any comments. 

Include contact information each time 

you submit comments, data, documents, 

and other information to DOE. If you 

submit via mail or hand delivery/ 

courier, please provide all items on a 

CD, if feasible, in which case it is not 

necessary to submit printed copies. No 

telefacsimiles (faxes) will be accepted. 

Comments, data, and other 

information submitted to DOE 

electronically should be provided in 

PDF (preferred), Microsoft Word or 

Excel, WordPerfect, or text (ASCII) file 

format. Provide documents that are not 

secured, written in English, and are free 

of any defects or viruses. Documents 

should not contain special characters or 

any form of encryption and, if possible, 

they should carry the electronic 

signature of the author. 

Campaign form letters. Please submit 

campaign form letters by the originating 

organization in batches of between 50 to 

500 form letters per PDF or as one form 

letter with a list of supporters’ names 

compiled into one or more PDFs. This 

reduces comment processing and 

posting time. 

Confidential Business Information. 

Pursuant to 10 CFR 1004.11, any person 

submitting information that he or she 

believes to be confidential and exempt 

by law from public disclosure should 

submit via email, postal mail, or hand 

delivery/courier two well-marked 

copies: One copy of the document 

marked ‘‘confidential’’ including all the 

information believed to be confidential, 

and one copy of the document marked 

‘‘non-confidential’’ with the information 

believed to be confidential deleted. 

Submit these documents via email or on 

a CD, if feasible. DOE will make its own 

determination about the confidential 

status of the information and treat it 

according to its determination. 

Factors of interest to DOE when 

evaluating requests to treat submitted 

information as confidential include: (1) 

A description of the items; (2) whether 

and why such items are customarily 

treated as confidential within the 

industry; (3) whether the information is 

generally known by or available from 

other sources; (4) whether the 

information has previously been made 

available to others without obligation 

concerning its confidentiality; (5) an 

explanation of the competitive injury to 

the submitting person which would 

result from public disclosure; (6) when 

such information might lose its 

confidential character due to the 

passage of time; and (7) why disclosure 

of the information would be contrary to 

the public interest. 

It is DOE’s policy that all comments 

may be included in the public docket, 

without change and as received, 

including any personal information 

provided in the comments (except 

information deemed to be exempt from 

public disclosure). 

E. Issues on Which DOE Seeks Comment 

Although DOE welcomes comments 

on any aspect of this proposal, DOE is 

particularly interested in receiving 

comments and views of interested 

parties concerning the following issues: 

1. Is the proposed definition of ‘‘light 

commercial water heater’’ appropriate, 

and is it appropriate to test commercial 

water heaters meeting this definition 

under the uniform descriptor, while 

testing all other commercial water 

heaters using thermal efficiency and 

standby loss? 

2. Is information or data available 

regarding the translation of current firsthour ratings to a first-hour rating 

determined using the proposed 125 °F 

set point? What is the effect of such 

translation on the appropriate 

breakpoints between different size 

categories? 

3. Is the proposed method of 

characterizing water heaters as point-ofuse, low, medium, or high appropriate 

and sufficient? 

4. Are the draw patterns proposed for 

the different water heater size categories 

appropriate? 

5. What is the added burden, if any, 

in requiring a 24-hour pre-conditioning 

period for storage-type water heaters 

compared to current practice? 

6. Is the proposed change to the 

nominal water delivery temperature to 

125 °F appropriate, and if not, what data 

or information is available that would 

justify a different water delivery 

temperature? 

7. Is the proposed method for setting 

the thermostat(s) of storage-type water 

heaters appropriate? 

8. The addition of terms to quantify 

daily electric energy consumption 

separately from fossil fuel energy 

consumption and adding separate 

estimates of annual fossil fuel energy 

consumption and annual electrical 

energy consumption in addition to the 

overall annual energy consumption. 

VI. Approval of the Office of the 

Secretary 

The Secretary of Energy has approved 

publication of today’s notice of 

proposed rulemaking. 

List of Subjects 

10 CFR Part 429 

Confidential business information, 

Energy conservation, Household 

appliances, Imports, Reporting and 

recordkeeping requirements. 

10 CFR Part 430 

Administrative practice and 

procedure, Confidential business 

information, Energy conservation, 

Household appliances, Imports, 

Incorporation by reference, 

Intergovernmental relations, Small 

businesses. 

10 CFR Part 431 

Administrative practice and 

procedure, Confidential business 

information, Test procedures, 

Incorporation by reference, Reporting 

and recordkeeping requirements. 

Issued in Washington, DC, on October 28, 

2013. 

Kathleen B. Hogan, 

Deputy Assistant Secretary for Energy 

Efficiency, Energy Efficiency and Renewable 

Energy. 

For the reasons stated in the 

preamble, DOE proposes to amend parts 

429, 430 and 431 of Chapter II, 

Subchapter D of Title 10, Code of 

Federal Regulations, as set forth below: 

PART 429—CERTIFICATION, 

COMPLIANCE, AND ENFORCEMENT 

FOR CONSUMER PRODUCTS AND 

COMMERCIAL AND INDUSTRIAL 

EQUIPMENT 

■ 1. The authority citation for part 429 

continues to read as follows: 

Authority: 42 U.S.C. 6291–6317. 

■ 2. Section 429.17 is amended by 

adding new paragraphs (a)(2)(iii), 

(a)(2)(iv), (c), and (d) to read as follows: 

§ 429.17 Residential water heaters. 

(a) * * * 

(2) * * * 


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(iii) Any represented value of the 

rated storage volume must be calculated 

as the mean of the measured storage 

volumes, Vst, of all the units within the 

sample. 

(iv) Any represented value of firsthour rating for storage water heaters or 

maximum gallons per minute (gpm for 

instantaneous water heaters must be 

calculated as the mean of the measured 

first-hour ratings or measured max gpm 

ratings, respectively, of all the units 

within the sample. 

* * * * * 

(c) Determination of ratings for 

untested basic models. Manufacturers of 

gas-fired water heaters are not required 

to test other models that differ from 

tested basic models only in whether the 

unit uses natural gas or propane gas. In 

lieu of testing, the represented value for 

a model that utilizes propane gas must 

be identical to the basic model that 

utilizes natural gas as long as the rated 

input ratings are within ±10% for both 

basic models. 

(d) Represented values. The 

requirements of § 429.17 are applicable 

to all values reported in accordance 

with paragraphs (b) and (c) of this 

section. Represented values of energy 

factor shall be rounded off to the nearest 

0.01. 

■ 3. Section 429.44 is amended by: 

■ a. Redesignating paragraphs (a), (b) 

and (c) as (b), (c) and (d); 

■ b. Adding a new paragraph (a); and 

■ c. Revising newly redesignated 

paragraph (b). 

The revisions and additions read as 

follows: 

§ 429.44 Commercial water heating 

equipment. 

(a) For light commercial water 

heaters, all represented values should be 

determined in accordance with § 429.17. 

(b) Determination of Represented 

Value for All Types of Commercial 

Water Heaters except Light Commercial 

Water Heaters. Manufacturers can 

determine the represented value, which 

includes the certified rating, for each 

basic model of commercial water 

heating equipment except light 

commercial water heaters, either by 

testing, in conjunction with the 

applicable sampling provisions, or by 

applying a validated AEDM. 

* * * * * 

■ 4. Add § 429.134 to read as follows: 

§ 429.134 Product-specific enforcement 

provisions. 

(a) [Reserved]. 

(b) [Reserved]. 

(c) [Reserved]. 

(d) Residential Water Heaters and 

Light Commercial Water Heaters. (1) 

Verification of rated first-hour rating 

and rated maximum gpm rating. The 

first-hour rating (for storage water 

heaters) or maximum gallons per minute 

(gpm) rating (for instantaneous water 

heaters) of the basic model will be 

measured pursuant to the test 

requirements of part 430 for each unit 

tested. The results of the 

measurement(s) will be averaged and 

compared to the value of first-hour 

rating (for storage water heaters) or 

maximum gpm rating (for instantaneous 

water heaters) certified by the 

manufacturer. The certified rating will 

be considered valid only if the 

measurement is within five percent of 

the certified rating. 

(i) If the certified first-hour rating or 

maximum gpm rating is found to be 

valid, that rating will be used as the 

basis for determining the applicable 

draw pattern pursuant to the test 

requirements of part 430 for each unit 

tested. 

(ii) If the certified first-hour rating or 

maximum gpm rating is found to be 

invalid, the average measured rating 

will serve as the basis for determining 

the applicable draw pattern pursuant to 

the test requirements of part 430 for 

each unit tested. 

(2) Verification of rated storage 

volume. The storage volume of the basic 

model will be measured pursuant to the 

test requirements of part 430 for each 

unit tested. The results of the 

measurement(s) will be averaged and 

compared to the rated storage volume 

certified by the manufacturer. The 

certified rating will be considered valid 

only if the measurement is within five 

percent of the certified rating. 

(i) If the certified rated storage volume 

is found to be valid, that volume will be 

used as the basis for calculation of the 

required energy factor for the basic 

model. 

(ii) If the certified rated storage 

volume is found to be invalid, the 

average measured volume will be used 

as the basis for calculation of the 

required energy factor for the basic 

model. 

PART 430—ENERGY CONSERVATION 

PROGRAM FOR CONSUMER 

PRODUCTS 

■ 5. The authority citation for part 430 

continues to read as follows: 

Authority: 42 U.S.C. 6291–6309; 28 U.S.C. 

2461 note. 

■ 6. Section 430.2 is amended by adding 

the definitions of ‘‘Electric 

instantaneous water heater,’’ ‘‘Electric 

storage water heater,’’ ‘‘Gas-fired 

instantaneous water heater,’’ ‘‘Gas-fired 

storage water heater,’’ ‘‘Heat pump 

water heater,’’ and ‘‘Oil storage water 

heater’’ in alphabetical order, to read as 

follows: 

§ 430.2 Definitions. 

* * * * * 

Electric instantaneous water heater 

means a water heater that uses 

electricity as the energy source, initiates 

heating based on sensing water flow, is 

not capable of delivering water at a 

controlled temperature of 180 °F (82 °C) 

or greater, has a maximum nameplate 

input rating 12 kW (40,956 Btu/h) or 

less, and has a rated storage capacity of 

less than 2 gallons (7.6 liters). The unit 

may use a fixed or variable burner 

input. 

* * * * * 

Electric storage water heater means a 

water heater that uses electricity as the 

energy source, is not capable of heating 

and storing water at a thermostatically 

controlled temperature of 180 °F (82 °C) 

or greater, has a maximum nameplate 

input rating of 12 kW (40,956 Btu/h) or 

less, and has a rated storage capacity of 

not less than 2 gallons (7.6 liters) nor 

more than 120 gallons (450 liters). 

* * * * * 

Gas-fired instantaneous water heater 

means a water heater that uses gas as the 

main energy source, initiates heating 

based on sensing water flow, is not 

capable of delivering water at a 

controlled temperature of 180 °F (82 °C) 

or greater, has a maximum nameplate 

input rating less than 200,000 Btu/h 

(210 MJ/h), and has a rated storage 

capacity of less than 2 gallons (7.6 

liters). The unit may use a fixed or 

variable burner input. 

Gas-fired storage water heater means 

a water heater that uses gas as the main 

energy source, is not capable of heating 

and storing water at a thermostatically 

controlled temperature of 180 °F (82 °C) 

or greater, has a maximum nameplate 

input rating of 75,000 Btu/h (79 MJ/h) 

or less, and has a rated storage capacity 

of not less than 2 gallons (7.6 liters) nor 

more than 120 gallons (380 liters). 

* * * * * 

Heat pump water heater means a 

water heater that uses electricity as the 

energy source, is not capable of heating 

and storing water at a thermostaticallycontrolled temperature of 180 °F (82 °C) 

or greater, has a maximum current 

rating of 24 amperes (including the 

compressor and all auxiliary equipment 

such as fans, pumps, controls, and, if on 

the same circuit, any resistive elements) 

for an input voltage of 250 volts or less, 

and, has a rated storage capacity of 120 

gallons (450 liters) or less. 

* * * * * 


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Oil storage water heater means a 

water heater that uses oil as the energy 

source, is not capable of heating and 

storing water at a thermostatically 

controlled temperature of 180 °F (82 °C) 

or greater, has a nameplate input rating 

of 105,000 Btu/h (110 MJ/h) or less, and 

has a manufacturer’s rated storage 

capacity of 120 gallons (190 liters) or 

less. 

* * * * * 

■ 7. Section 430.3 is amended by: 

■ a. Adding paragraph (f)(11); 

■ b. Redesignating paragraphs (h) 

through (p) as (i) through (o), 

respectively; and 

■ c. Adding a new paragraph (h). 

The additions read as follows: 

§ 430.3 Materials incorporated by 

reference. 

* * * * * 

(f) * * * 

(11) ASHRAE 41.1–1986 (RA 2006), 

Standard Method for Temperature 

Measurement, ASHRAE approved June 

27, 2007, ANSI approved March 25, 

2008, IBR approved for appendix E to 

subpart B of this part. 

* * * * * 

(h) ASTM. American Society for 

Testing and Materials International, 100 

Barr Harbor Drive, P.O. Box C700, West 

Conshohocken, PA 19428–2959 

(www.astm.org). 

(1) ASTM D2156–09 (‘‘ASTM 

D2156’’), Standard Test Method for 

Smoke Density in Flue Gases from 

Burning Distillate Fuels, Edition 09, 

ASTM approved December 1, 2009, IBR 

approved for appendix E to subpart B of 

this part. 

(2) [Reserved] 

* * * * * 

■ 8. Section 430.23 is amended by 

revising paragraph (e) to read as follows: 

§ 430.23 Test procedures for the 

measurement of energy and water 

consumption. 

* * * * * 

(e) Water Heaters. (1) The estimated 

annual operating cost for water heaters 

shall be— 

(i) For a gas or oil water heater, the 

sum of (a) the product of the annual gas 

or oil energy consumption, determined 

according to section 6.1.10 or 6.2.7 of 

appendix E of this subpart, times the 

representative average unit cost of gas or 

oil, as appropriate, in dollars per Btu as 

provided by the Secretary; plus (b) the 

product of the annual electric energy 

consumption, determined according to 

section 6.1.9 or 6.2.6 of appendix E of 

this subpart, times the representative 

average unit cost of electricity in dollars 

per kilowatt-hour as provided by the 

Secretary, the resulting sum then being 

rounded off to the nearest dollar per 

year. 

(ii) For an electric water heater, the 

product of the annual energy 

consumption, determined according to 

section 6.1.9 or 6.2.6 of appendix E of 

this subpart, times the representative 

average unit cost of electricity in dollars 

per kilowatt-hour as provided by the 

Secretary, the resulting product then 

being rounded off to the nearest dollar 

per year. 

(2) For an individual test, the tested 

energy factor for a water heater shall 

be— 

(i) For a gas or oil water heater, as 

determined by section 6.1.7 or 6.2.4 of 

appendix E of this subpart rounded to 

the nearest 0.01. 

(ii) For an electric water heater, as 

determined by section 6.1.7 or 6.2.4 of 

appendix E of this subpart rounded to 

the nearest 0.01. 

* * * * * 

■ 9. Appendix E to Subpart B of Part 

430 is revised to read as follows: 

Appendix E to Subpart B of Part 430— 

Uniform Test Method for Measuring the 

Energy Consumption of Water Heaters 

Note: After [date 365 days after publication 

of a final rule in the Federal Register that 

establishes a conversion factor, or December 

31, 2015, whichever is later], any 

representations made with respect to the 

energy use or efficiency of residential water 

heaters and commercial water heaters 

covered by this test method must be made in 

accordance with the results of testing 

pursuant to this appendix. 

Manufacturers conducting tests of 

residential water heaters and commercial 

water heaters covered by this test method 

after [date 365 days after publication of the 

test procedure final rule in the Federal 

Register] and prior to [date 365 days after 

publication of the final rule in the Federal 

Register that establishes a conversion factor, 

or December 31, 2015, whichever is later] 

must conduct such test in accordance with 

either this appendix or previous test method. 

For residential water heaters the previous test 

method is appendix E as it appeared at 10 

CFR part 430, subpart B, appendix E, in the 

10 CFR parts 200 to 499 edition revised as 

of January 1, 2013. For commercial water 

heaters the previous test method is 10 CFR 

431.106 in the 10 CFR parts 200 to 499 

edition revised as of January 1, 2013. Any 

representations made with respect to the 

energy use or efficiency of such water heaters 

must be in accordance with whichever 

version is selected. 

1. Definitions 

1.1. Cut-in means the time when or water 

temperature at which a water heater control 

or thermostat acts to increase the energy or 

fuel input to the heating elements, 

compressor, or burner. 

1.2. Cut-out means the time when or water 

temperature at which a water heater control 

or thermostat acts to reduce to a minimum 

the energy or fuel input to the heating 

elements, compressor, or burner. 

1.3. Design Power Rating means the 

nominal power rating that a water heater 

manufacturer assigns to a particular design of 

water heater, expressed in kilowatts or Btu 

(kJ) per hour as appropriate. 

1.4. Draw Cluster means a collection of 

water draw events during the simulated-use 

test that are closely grouped in time. 

1.5. Energy Factor means the measure of 

water heater overall efficiency. 

1.6. First-Hour Rating means the estimate 

of the maximum volume of ‘‘hot’’ water that 

a storage-type water heater can supply within 

an hour that begins with the water heater 

fully heated (i.e., with all thermostats 

satisfied). It is a function of both the storage 

volume and the recovery rate. 

1.7. Heat Trap means a device which can 

be integrally connected or independently 

attached to the hot and/ or cold water pipe 

connections of a water heater such that the 

device will develop a thermal or mechanical 

seal to minimize the recirculation of water 

due to thermal convection between the water 

heater tank and its connecting pipes. 

1.8. Maximum gpm (L/ min) Rating means 

the maximum gallons per minute (liters per 

minute) of hot water that can be supplied by 

an instantaneous water heater while 

maintaining a nominal temperature rise of 67 

°F (37.3 °C) during steady-state operation, as 

determined by testing in accordance with 

section 5.3.2 of this appendix. 

1.9. Rated Storage Volume means the water 

storage capacity of a water heater, in gallons 

(liters), as certified by the manufacturer 

pursuant to 10 CFR part 429. 

1.10. Recovery Efficiency means the ratio of 

energy delivered to the water to the energy 

content of the fuel consumed by the water 

heater. 

1.11. Recovery Period means the time when 

the main burner of a storage water heater is 

raising the temperature of the stored water. 

1.12. Standby means the time, in hours, 

during which water is not being withdrawn 

from the water heater. There are two standby 

time intervals used within this test 

procedure: tstby,1 represents the elapsed time 

between the time at which the maximum 

mean tank temperature is observed after the 

first draw cluster and the minute prior to the 

start of the first draw following the end of the 

first draw cluster of the 24-hour simulated 

use test; tstby,2 represents the total time 

during the 24-hour simulated use test when 

water is not being withdrawn from the water 

heater. 

1.13. Symbol Usage. The following identity 

relationships are provided to help clarify the 

symbology used throughout this procedure: 

Cp specific heat of water 

Eannual annual energy consumption of a 

water heater 

Eannual,e annual electrical energy 

consumption of a water heater 

Eannual,f annual fossil-fuel energy 

consumption of a water heater 

Ef energy factor of a water heater 

Fhr first-hour rating of a storage-type water 

heater 

Fmax maximum gpm (L/ min) rating of an 

instantaneous water heater rated at a 

temperature rise of 67 °F (37.3 °C) 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
66232 Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 

i a subscript to indicate the draw number 

during a test 

Mi mass of water removed during the ith 

draw of the 24-hr simulated use test 

M*i for storage-type water heaters, mass of 

water removed during the ith draw during 

the first-hour rating test 

M10m for instantaneous water heaters, mass 

of water removed continuously during a 

10-minute interval in the maximum gpm 

(L/min) rating test 

n for storage-type water heaters, total 

number of draws during the first-hour 

rating test 

N total number of draws during the 24-hr 

simulated use test 

Q total fossil fuel and/or electric energy 

consumed during the entire 24-hr 

simulated use test 

Qd daily water heating energy consumption 

adjusted for net change in internal energy 

Qda Qd with adjustment for variation of tank 

to ambient air temperature difference from 

nominal value 

Qdm overall adjusted daily water heating 

energy consumption including Qda and 

QHWD

Qe total electrical energy used during the 

24-hour simulated use test 

Qf total fossil fuel energy used by the water 

heater during the 24-hour simulated use 

test 

Qhr hourly standby losses 

QHW daily energy consumption to heat 

water at the measured average temperature 

rise across the water heater 

QHW,67 °F daily energy consumption to heat 

quantity of water removed during test over 

a temperature rise of 67 °F (37.3 °C) 

QHWD adjustment to daily energy 

consumption, QHW, due to variation of the 

temperature rise across the water heater 

not equal to the nominal value of 67 °F 

Qr energy consumption of water heater 

from the beginning of the test to the end 

of the first recovery period following the 

first draw, which may extend beyond 

subsequent draws 

Qstby total energy consumed by the water 

heater during the standby time interval 

tstby,1

Qsu,0 total fossil fuel and/or electric energy 

consumed from the beginning of the test to 

the end of the cutout following the first 

draw cluster 

Qsu,f total fossil fuel and/or electric energy 

consumed from the beginning of the test to 

the initiation of the first draw following the 

first draw cluster 

T0 mean tank temperature at the beginning 

of the 24-hr simulated use test 

T24 mean tank temperature at the end of the 

24-hr simulated use test 

Ta,stby average ambient air temperature 

during standby periods of the 24-hr 

simulated use test 

Tdel for instantaneous water heaters, average 

outlet water temperature during a 10- 

minute continuous draw interval in the 

maximum gpm (L/ min) rating test 

Tdel,i average outlet water temperature 

during the ith draw of the 24-hr simulated 

use test 

Tin for instantaneous water heaters, average 

inlet water temperature during a 10-minute 

continuous draw interval in the maximum 

gpm (L/ min) rating test 

Tin,i average inlet water temperature during 

the ith draw of the 24-hr simulated use test 

Tmax,1 maximum measured mean tank 

temperature after cut-out following the first 

draw of the 24-hr simulated use test 

Tstby average storage tank temperature 

during the standby period tstby,2 of the 24- 

hr simulated use test 

Tsu,0 maximum measured mean tank 

temperature at the beginning of the standby 

period which occurs after cut-out following 

the final draw of the first draw cluster 

Tsu,f measured mean tank temperature at the 

end of the standby period which occurs at 

the minute prior to commencement of the 

first draw that follows the end of the first 

draw cluster 

Tt,stby average storage tank temperature 

during the standby period tstby,1 of the 24- 

hr simulated use test 

T*

del,i for storage-type water heaters, average 

outlet water temperature during the ith 

draw (i=1 to n) of the first-hour rating test 

T*

max,i for storage-type water heaters, 

maximum outlet water temperature 

observed during the ith draw (i=1 to n) of 

the first-hour rating test 

T*

min,i for storage-type water heaters, 

minimum outlet water temperature to 

terminate the ith draw (i=1 to n) of the 

first-hour rating test 

UA standby loss coefficient of a storagetype water heater 

Vi volume of water removed during the ith 

draw (i=1 to N) of the 24-hr simulated use 

test 

V*i volume of water removed during the ith 

draw (i=1 to n) of the first-hour rating test 

V10m for instantaneous water heaters, 

volume of water removed continuously 

during a 10-minute interval in the 

maximum gpm (L/ min) rating test 

Vst measured storage volume of the storage 

tank 

Wf weight of storage tank when completely 

filled with water 

Wt tare weight of storage tank when 

completely empty of water 

hr recovery efficiency 

r density of water 

tstby,1 elapsed time between the time the 

maximum mean tank temperature is 

observed after the first draw cluster and the 

minute prior to the start of the first draw 

following the first draw cluster 

tstby,2 overall time of standby periods when 

no water is withdrawn during the 24-hr 

simulated use test 

2. Test Conditions 

2.1 Installation Requirements. Tests shall 

be performed with the water heater and 

instrumentation installed in accordance with 

Section 4 of this appendix. 

2.2 Ambient Air Temperature. The 

ambient air temperature shall be maintained 

between 65.0 °F and 70.0 °F (18.3 °C and 21.1 

°C) on a continuous basis. For heat pump 

water heaters, the dry bulb temperature shall 

be maintained at 67.5 °F ± 1 °F (19.7 °C ± 

0.6 °C) and, in addition, the relative humidity 

shall be maintained between 48% and 52% 

throughout the test. 

2.3 Supply Water Temperature. The 

temperature of the water being supplied to 

the water heater shall be maintained at 58 °F 

± 2 °F (14.4 °C ± 1.1 °C) throughout the test. 

2.4 Storage Tank Temperature. The 

thermostats of a storage-type water heater 

shall be set so that water is delivered at a 

temperature of 125 °F ± 5 °F (51.7°C ± 2.8 °C). 

2.5 Set Point Temperature. The 

thermostat of instantaneous water heaters 

shall be set to deliver water at a temperature 

of 125 °F ± 5 °F (51.7 °C ± 2.8 °C). 

2.6 Supply Water Pressure. During the 

test when water is not being withdrawn, the 

supply pressure shall be maintained between 

40 psig (275 kPa) and the maximum 

allowable pressure specified by the water 

heater manufacturer. 

2.7 Electrical and/ or Fossil Fuel Supply. 

2.7.1 Electrical. Maintain the electrical 

supply voltage to within ±1% of the center 

of the voltage range specified by the water 

heater and/or heat pump manufacturer. 

2.7.2 Natural Gas. Maintain the supply 

pressure in accordance with the 

manufacturer’s specifications. If the supply 

pressure is not specified, maintain a supply 

pressure of 7–10 inches of water column 

(1.7–2.5 kPa). If the water heater is equipped 

with a gas appliance pressure regulator, the 

regulator outlet pressure shall be within ± 

10% of the manufacturer’s specified 

manifold pressure. For all tests, use natural 

gas having a heating value of approximately 

1,025 Btu per standard cubic foot (38,190 kJ 

per standard cubic meter). 

2.7.3 Propane Gas. Maintain the supply 

pressure in accordance with the 

manufacturer’s specifications. If the supply 

pressure is not specified, maintain a supply 

pressure of 11–13 inches of water column 

(2.7–3.2 kPa). If the water heater is equipped 

with a gas appliance pressure regulator, the 

regulator outlet pressure shall be within ± 

10% of the manufacturer’s specified 

manifold pressure. For all tests, use propane 

gas with a heating value of approximately 

2,500 Btu per standard cubic foot (93,147 kJ 

per standard cubic meter). 

2.7.4 Fuel Oil Supply. Maintain an 

uninterrupted supply of fuel oil. Use fuel oil 

having a heating value of approximately 

138,700 Btu per gallon (38,660 kJ per liter). 

3. Instrumentation 

3.1 Pressure Measurements. Pressuremeasuring instruments shall have an error no 

greater than the following values: 

Item measured Instrument accuracy Instrument precision 

Gas pressure ...................................................... ±0.1 inch of water column (±0.025 kPa) ......... ±0.05 inch of water column (±0.012 kPa). 

Atmospheric pressure ........................................ ±0.1 inch of mercury column (±0.34 kPa) ....... ±0.05 inch of mercury column (±0.17 kPa). 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
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Item measured Instrument accuracy Instrument precision 

Water pressure ................................................... ±1.0 pounds per square inch (±6.9 kPa) ......... ±0.50 pounds per square inch (±3.45 kPa). 

3.2 Temperature Measurement 

3.2.1 Measurement. Temperature 

measurements shall be made in accordance 

with the Standard Method for Temperature 

Measurement, ASHRAE Standard 41.1–1986 

(RA 2006). 

3.2.2 Accuracy and Precision. The 

accuracy and precision of the instruments, 

including their associated readout devices, 

shall be within the following limits: 

Item measured Instrument accuracy Instrument precision 

Air dry bulb temperature .................................... ±0.2 °F (±0.1 °C) .............................................. ±0.1 °F (±0.06 °C). 

Air wet bulb temperature .................................... ±0.2 °F (±0.1 °C) .............................................. ±0.1 °F (±0.06 °C). 

Inlet and outlet water temperatures ................... ±0.2 °F (±0.1 °C) .............................................. ±0.1 °F (±0.06 °C). 

Storage tank temperatures ................................. ±0.5 °F (±0.3 °C) .............................................. ±0.25 °F (±0.14 °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 × 4 inch (5 cm 

× 10 cm) runners. If the water heater is not 

approved for installation on combustible 

flooring, suitable non-combustible material 

shall be placed between the water heater and 

the platform. Counter-top water heaters shall 

be placed against a simulated wall section. 

Wall-mounted water heaters shall be 

supported on a simulated wall in accordance 

with the manufacturer-published installation 

instructions. When a simulated wall is used, 

the construction shall be 2 × 4 inch (5 cm × 

10 cm) studs, faced with 3⁄4 inch (2 cm) 

plywood. For heat pump water heaters not 

delivered as a single package, the units shall 

be connected in accordance with the 

manufacturer-published installation 

instructions and the overall system shall be 

placed on the above-described plywood 

platform. If installation instructions are not 

provided by the heat pump manufacturer, 

uninsulated 8 foot (2.4 m) long connecting 

hoses having an inside diameter of 5⁄8 inch 

(1.6 cm) shall be used to connect the storage 

tank and the heat pump water heater. The 

testing of the water heater shall occur in an 

area that is protected from drafts of more 

than 50 ft/ min (2.5 m/s) from room 

ventilation registers, windows, or other 

external sources of air movement. 

4.2 Water Supply. Connect the water 

heater to a water supply capable of delivering 

water at conditions as specified in Sections 

2.3 and 2.6 of this appendix. 

4.3 Water Inlet and Outlet Configuration. 

For freestanding water heaters that are taller 

than 36 inches (91.4 cm), inlet and outlet 

piping connections shall be configured in a 

manner consistent with Figures 1 and 2. Inlet 

and outlet piping connections for wallmounted water heaters shall be consistent 

with Figure 3. For freestanding water heaters 

that are 36 inches or less in height and not 

supplied as part of a counter-top enclosure 

(commonly referred to as an under-thecounter model), inlet and outlet piping shall 

be installed in a manner consistent with 

Figures 4, 5, and 6. For water heaters that are 

supplied with a counter-top enclosure, inlet 

and outlet piping shall be made in a manner 

consistent with Figures 7A and 7B, 

respectively. The vertical piping noted in 

Figures 7A and 7B shall be located (whether 

inside the enclosure or along the outside in 

a recessed channel) in accordance with the 

manufacturer-published installation 

instructions. 

All dimensions noted in Figures 1 through 

7 shall be achieved. All piping between the 

water heater and inlet and outlet temperature 

sensors, noted as TIN and TOUT in the figures, 

shall be Type ‘‘L’’ hard copper having the 

same diameter as the connections on the 

water heater. Unions may be used to facilitate 

installation and removal of the piping 

arrangements. A pressure gauge and 

diaphragm expansion tank shall be installed 

in the supply water piping at a location 

upstream of the inlet temperature sensor. An 

appropriately rated pressure and temperature 

relief valve shall be installed on all water 

heaters at the port specified by the 

manufacturer. Discharge piping for the relief 

valve shall be non-metallic. If heat traps, 

piping insulation, or pressure relief valve 

insulation are supplied with the water heater, 

they shall be installed for testing. Except 

when using a simulated wall, clearance shall 

be provided such that none of the piping 

contacts other surfaces in the test room. 

4.4 Fuel and/or Electrical Power and 

Energy Consumption. Install one or more 

instruments that measure, as appropriate, the 

quantity and rate of electrical energy and/or 

fossil fuel consumption in accordance with 

section 3. 

4.5 Internal Storage Tank Temperature 

Measurements. For water heaters with rated 

storage volumes greater than or equal to 20 

gallons, install six temperature measurement 

sensors inside the water heater tank with a 

vertical distance of at least 4 inches (100 mm) 

between successive sensors. For water 

heaters with rated storage volumes between 

2 and 20 gallons, install three temperature 

measurement sensors inside the water heater 


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tank. A temperature sensor shall be 

positioned at the vertical midpoint of each of 

the six equal volume nodes within a tank 

larger than 20 gallons or the three equal 

volume nodes within a tank between 2 and 

20 gallons. Nodes designate the equal 

volumes used to evenly partition the total 

volume of the tank. As much as is possible, 

the temperature sensor should be positioned 

away from any heating elements, anodic 

protective devices, tank walls, and flue pipe 

walls. If the tank cannot accommodate six 

temperature sensors and meet the installation 

requirements specified above, install the 

maximum number of sensors which comply 

with the installation requirements. The 

temperature sensors shall be installed either 

through: (1) The anodic device opening; (2) 

the relief valve opening; or (3) the hot water 

outlet. If installed through the relief valve 

opening or the hot water outlet, a tee fitting 

or outlet piping, as applicable, shall be 

installed as close as possible to its original 

location. If the relief valve temperature 

sensor is relocated, and it no longer extends 

into the top of the tank, a substitute relief 

valve that has a sensing element that can 

reach into the tank shall be installed. If the 

hot water outlet includes a heat trap, the heat 

trap shall be installed on top of the tee fitting. 

Added fittings shall be covered with thermal 

insulation having an R value between 4 and 

8 h·ft2·°F/Btu (0.7 and 1.4 m2·°C/W). 

4.6 Ambient Air Temperature 

Measurement. Install an ambient air 

temperature sensor at the vertical mid-point 

of the water heater and approximately 2 feet 

(610 mm) from the surface of the water 

heater. The sensor shall be shielded against 

radiation. 

4.7 Inlet and Outlet Water Temperature 

Measurements. Install temperature sensors in 

the cold-water inlet pipe and hot-water outlet 

pipe as shown in Figures 1, 2, 3, 4, 5, 6, 7a, 

and 7b, as applicable. 

4.8 Flow Control. A valve or valves shall 

be installed to provide flow as specified in 

sections 5.2.4.1 and 5.4 for storage tank water 

heaters and sections 5.3.1 and 5.4 for 

instantaneous water heaters. 

4.9 Flue Requirements. 

4.9.1 Gas-Fired Water Heaters. Establish a 

natural draft in the following manner. For 

gas-fired water heaters with a vertically 

discharging draft hood outlet, a 5-foot (1.5- 

meter) vertical vent pipe extension with a 

diameter equal to the largest flue collar size 

of the draft hood shall be connected to the 

draft hood outlet. For gas-fired water heaters 

with a horizontally discharging draft hood 

outlet, a 90-degree elbow with a diameter 

equal to the largest flue collar size of the draft 

hood shall be connected to the draft hood 

outlet. A 5-foot (1.5-meter) length of vent 

pipe shall be connected to the elbow and 

oriented to discharge vertically upward. 

Direct vent gas-fired water heaters shall be 

installed with venting equipment specified in 

the manufacturer’s instructions using the 

minimum vertical and horizontal lengths of 

vent pipe recommended by the manufacturer. 

4.9.2 Oil-Fired Water Heaters. Establish a 

draft at the flue collar at the value specified 

in the manufacturer’s instructions. Establish 

the draft by using a sufficient length of vent 

pipe connected to the water heater flue 

outlet, and directed vertically upward. For an 

oil-fired water heater with a horizontally 

discharging draft hood outlet, a 90-degree 

elbow with a diameter equal to the largest 

flue collar size of the draft hood shall be 

connected to the draft hood outlet. A length 

of vent pipe sufficient to establish the draft 

shall be connected to the elbow fitting and 

oriented to discharge vertically upward. 

Direct-vent oil-fired water heaters should be 

installed with venting equipment as specified 

in the manufacturer’s instructions, using the 

minimum vertical and horizontal lengths of 

vent pipe recommended by the manufacturer. 

5. Test Procedures 

5.1 Operational Mode Selection. For 

water heaters that allow for multiple userselected operational modes, all procedures 

specified in this appendix shall be carried 

out with the water heater in the same 

operational mode (i.e., only one mode). This 

operational mode shall be the default mode 

(or similarly-named, suggested mode for 

normal operation) as defined by the 

manufacturer in its product literature for 

giving selection guidance to the consumer. 

For heat pump water heaters, if a default 

mode is not defined in the product literature, 

each test shall be conducted under an 

operational mode in which both the heat 

pump and any electric resistance backup 

heating element(s) are activated by the unit’s 

control scheme, and which can achieve the 

internal storage tank temperature specified in 

this test procedure; if multiple operational 

modes meet these criteria, the water heater 

shall be tested under the most energyintensive mode. If no default mode is 

specified and the unit does not offer an 

operational mode that utilizes both the heat 

pump and the electric resistance backup 

heating element(s), the first-hour rating test 

and the simulated-use test shall be tested in 

heat-pump-only mode. For other types of 

water heaters where a default mode is not 

specified, test the unit in the most energyintensive mode. 

5.2 Storage-type Water Heaters, Including 

Heat Pump Water Heaters. 

5.2.1 Determination of Storage Tank 

Volume. Determine the storage capacity, Vst,

of the water heater under test, in gallons 

(liters), by subtracting the tare weight— 

measured while the tank is empty—from the 

gross weight of the storage tank when 

completely filled with water (with all air 

eliminated and line pressure applied as 

described in section 2.5) and dividing the 

resulting net weight by the density of water 

at the measured temperature. 

5.2.2 Setting the Thermostat. 

5.2.2.1 Single Thermostat Tanks. 

5.2.2.1.1 Water Heaters with Rated 

Volumes Less than 20 Gallons. Starting with 

a tank at the supply water temperature, 

initiate normal operation of the water heater. 

After cut-out, initiate a draw from the water 

heater at a flow rate of 1.0 gallon ± 0.25 

gallons per minute (3.8 liters ± 0.95 liters per 

minute) for 2 minutes. Starting 15 seconds 

after commencement of draw, record the 

outlet temperature at 15-second intervals 

until the end of the 2-minute period. 

Determine whether the maximum outlet 

temperature is within the range of 125 °F ± 

5 °F (51.7 °C ± 2.8 °C). If not, turn off the 

water heater, adjust the thermostat, and then 

drain and refill the tank with supply water. 

Then, once again, initiate normal operation 

of the water heater, and repeat the 2-minute 

outlet temperature test following cut-out. 

Repeat this sequence until the maximum 

outlet temperature during the 2-minute test is 

within of 125 °F ± 5 °F (51.7 °C ± 2.8 °C). 

5.2.2.1.2 Water Heaters with Rated 

Volumes Greater than or Equal to 20 Gallons. 

Starting with a tank at the supply water 

temperature, initiate normal operation of the 

water heater. After cut-out, initiate a draw 

from the water heater at a flow rate of 1.7 

gallons ± 0.25 gallons per minute (6.4 liters 

± 0.95 liters per minute) for 5 minutes. 

Starting 15 seconds after commencement of 

draw, record the outlet temperature at 15- 

second intervals until the end of the 5- 

minute period. Determine whether the 

maximum outlet temperature is within the 

range of 125 °F ± 5 °F (51.7 °C ± 2.8 °C). If 

not, turn off the water heater, adjust the 

thermostat, and then drain and refill the tank 

with supply water. Then, once again, initiate 

normal operation of the water heater, and 

repeat the 5-minute outlet temperature test 

following cut-out. Repeat this sequence until 

the maximum outlet temperature during the 

5-minute test is within of 125 °F ± 5 °F (51.7 

°C ± 2.8 °C). 

5.2.2.2 Tanks with Two or More 

Thermostats. Follow the same sequence as 

for a single thermostat tank (i.e., start at the 

supply water temperature; operate normally 

until cut-out). Determine if the setting of the 

thermostat that controls the uppermost 

heating elements yields a maximum water 

temperature of 125 °F ± 5 °F (51.7 °C ± 2.8 

°C), as measured by the in-tank sensors that 

are positioned above the uppermost heating 

element. If the tank temperature above the 

uppermost heating element is not within 125 

°F ± 5 °F (51.7 °C ± 2.8 °C), turn off the water 

heater, adjust the thermostat, and then drain 

and refill the tank with supply water. The 

thermostat that controls the heating element 

positioned next highest in the tank shall then 

be set to yield a maximum water temperature 

of 125 °F ± 5 °F (51.7 °C ± 2.8 °C). This 

process shall be repeated for the remaining 

heating elements in reverse order of height 

until the thermostat controlling the lowest 

element is correctly adjusted. When adjusting 

the thermostat that controls the lowest 

element, the maximum mean tank 

temperature after cut-out, as determined 

using all the in-tank sensors, shall be 125 °F 

± 5 °F (51.7 °C ± 2.8 °C). When adjusting all 

other thermostats, use only the in-tank 

temperature sensors positioned above the 

heating element in question to evaluate the 

maximum mean water temperature as 

measured by these sensors after cut-out. For 

heat pump water heaters that control an 

auxiliary resistive element, the thermostat 

shall be set in accordance with the 

manufacturer’s installation instructions. 

5.2.3 Power Input Determination. For all 

water heaters except electric types, initiate 

normal operation (as described in section 5.1) 

and determine the power input, P, to the 

main burners (including pilot light power, if 

any) after 15 minutes of operation. If the 

water heater is equipped with a gas appliance 


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pressure regulator, the regulator outlet 

pressure shall be set within ±10% of that 

recommended by the manufacturer. For oilfired water heaters, the fuel pump pressure 

shall be within ±10% of the manufacturer’s 

specified pump pressure. All burners shall be 

adjusted to achieve an hourly Btu (kJ) rating 

that is within ±2% of the value specified by 

the manufacturer. For an oil-fired water 

heater, adjust the burner to give a CO2

reading recommended by the manufacturer 

and an hourly Btu (kJ) rating that is within 

±2% of that specified by the manufacturer. 

Smoke in the flue may not exceed No. 1 

smoke as measured by the procedure in 

ASTM–D–2156–09. 

5.2.4 First-Hour Rating Test. 

5.2.4.1 General. During hot water draws 

for water heaters with rated storage volumes 

greater than or equal to 20 gallons, remove 

water at a rate of 3.0 ± 0.25 gallons per 

minute (11.4 ± 0.95 liters per minute). During 

hot water draws, for storage-type water 

heaters with rated storage volumes below 20 

gallons, remove water at a rate of 1.0 ± 0.25 

gallon per minute ((3.8 ± 0.95 liters per 

minute). Collect the water in a container that 

is large enough to hold the volume removed 

during an individual draw and suitable for 

weighing at the termination of each draw. 

Alternatively, a water meter may be used to 

directly measure the water volume(s) 

withdrawn. 

5.2.4.2 Draw Initiation Criteria. Begin the 

first-hour rating test by imposing a draw on 

the storage-type water heater. After 

completion of this first draw, initiate 

successive draws based on the following 

criteria. For gas-fired and oil-fired water 

heaters, initiate successive draws when the 

thermostat acts to reduce the supply of fuel 

to the main burner. For electric water heaters 

having a single element or multiple elements 

that all operate simultaneously, initiate 

successive draws when the thermostat acts to 

reduce the electrical input supplied to the 

element(s). For electric water heaters having 

two or more elements that do not operate 

simultaneously, initiate successive draws 

when the applicable thermostat acts to 

reduce the electrical input to the element 

located vertically highest in the storage tank. 

For heat pump water heaters that do not use 

supplemental resistive heating, initiate 

successive draws immediately after the 

electrical input to the compressor is reduced 

by the action of the water heater’s thermostat. 

For heat pump water heaters that use 

supplemental resistive heating, initiate 

successive draws immediately after the 

electrical input to the compressor or the 

uppermost resistive element is reduced by 

the action of the applicable water heater 

thermostat. This draw initiation criterion for 

heat pump water heaters that use 

supplemental resistive heating, however, 

shall only apply when the water located 

above the thermostat at cut-out is heated to 

125 °F ± 5 °F (51.7 °C ± 2.8 °C). 

5.2.4.3 Test Sequence. Establish normal 

water heater operation. If the water heater is 

not presently operating, initiate a draw. The 

draw may be terminated any time after cutin occurs. After cut-out occurs (i.e., all 

thermostats are satisfied), monitor the 

internal storage tank temperature sensors 

described in section 4.5 every minute and 

determine the mean tank temperature by 

averaging the values from these sensors. 

Initiate a draw after a maximum mean tank 

temperature (the maximum of the mean 

temperatures of the individual sensors) has 

been observed following a cut-out. Record 

the time when the draw is initiated and 

designate it as an elapsed time of zero (t* = 

0). (The superscript * is used to denote 

variables pertaining to the first-hour rating 

test). Record the outlet water temperature 

beginning 15 seconds after the draw is 

initiated and at 5-second intervals thereafter 

until the draw is terminated. Determine the 

maximum outlet temperature that occurs 

during this first draw and record it as T*max,1. 

For the duration of this first draw and all 

successive draws, in addition, monitor the 

inlet temperature to the water heater to 

ensure that the required 58 °F ± 2 °F (14.4 

°C ± 1.1 °C) test condition is met. Terminate 

the hot water draw when the outlet 

temperature decreases to T*max,1¥15 °F 

(T*max,1¥8.3 °C). Record this temperature as 

T*min,1. Following draw termination, 

determine the average outlet water 

temperature and the mass or volume 

removed during this first draw and record 

them as T*

del,i and M*1 or V*1, respectively. 

Initiate a second and, if applicable, 

successive draw each time the applicable 

draw initiation criteria described in section 

5.2.4.2 are satisfied. As required for the first 

draw, record the outlet water temperature 15 

seconds after initiating each draw and at 5- 

second intervals thereafter until the draw is 

terminated. Determine the maximum outlet 

temperature that occurs during each draw 

and record it as T*max,i, where the subscript 

i refers to the draw number. Terminate each 

hot water draw when the outlet temperature 

decreases to T*max,i¥15 °F (T*max,i¥8.3 °C). 

Record this temperature as T*min,i. Calculate 

and record the average outlet temperature 

and the mass or volume removed during each 

draw (T*

del,i and M*i or V*i, respectively). 

Continue this sequence of draw and recovery 

until one hour has elapsed, then shut off the 

electrical power and/or fuel supplied to the 

water heater. 

If a draw is occurring at an elapsed time 

of one hour, continue this draw until the 

outlet temperature decreases to T*max,n¥15 

°F (T*max,n¥8.3 °C), at which time the draw 

shall be immediately terminated. (The 

subscript n shall be used to denote quantities 

associated with the final draw.) If a draw is 

not occurring at an elapsed time of one hour, 

a final draw shall be imposed at one hour. 

This draw shall proceed for a minimum of 30 

seconds and shall be immediately terminated 

thereafter when the outlet temperature first 

indicates a value less than or equal to the cutoff temperature used for the previous draw 

(T*min,n¥1). If an outlet temperature greater 

than T*min,n-1 is not measured within 30 

seconds zero additional credit shall be given 

towards first-hour rating (i.e., M*n = 0 or V*n

= 0) based on the final draw. After the final 

draw is terminated, calculate and record the 

average outlet temperature and the mass or 

volume removed during the draw (T*

del,n and 

M*n or V*n, respectively). 

5.2.5 24-Hour Simulated Use Test. 

5.2.5.1 Selection of Draw Pattern. The 

water heater will be tested under a draw 

profile that depends upon the rated first-hour 

rating obtained following the test prescribed 

in section 5.2.4 of this appendix. One of four 

different patterns shall be applied based on 

the rated first-hour rating, as shown in Table 

I. 

TABLE I—DRAW PATTERN TO BE USED FOR STORAGE WATER HEATERS BASED ON RATED FIRST-HOUR RATING

Rated first-hour rating greater than or equal to: . . . and rated first-hour rating less than: Draw pattern to be used in 

simulated use test 

0 ................................................................................... 20 ................................................................................ Point-of-Use (Table III.1). 

20 ................................................................................. 55 ................................................................................ Low-Usage (Table III.2). 

55 ................................................................................. 80 ................................................................................ Medium-Usage (Table III.3). 

80 ................................................................................. No upper limit .............................................................. High-Usage (Table III.4). 

After completing the first-hour rating test 

in section 5.2.4, identify the appropriate 

draw pattern using Table I above. The draw 

patterns are provided in Tables III.1 through 

III.4 in section 5.4. Use the appropriate draw 

pattern when conducting the test sequence 

provided in section 5.2.5.2. 

5.2.5.2 Test Sequence. If the water heater 

is turned off, fill the water heater with supply 

water and apply pressure as described in 

section 2.6. Turn on the water heater and 

associated heat pump unit, if present. If the 

water heater is turned on, initiate a water 

draw that energizes the lowest heating 

element in the water heater. In either case, 

after the cut-out occurs, begin a 24-hour preconditioning period that draws water in the 

pattern specified by Table I (i.e., using Table 

III.1, Table III.2, Table III.3, or Table III.4, 

depending on the rated first-hour rating). No 

data need to be recorded during this 24-hour 

pre-conditioning period. At the end of this 

period, the 24-hour simulated-use test will 

begin. 

At the start of the 24-hour test (after the 24- 

hour pre-conditioning period), record the 

mean tank temperature (T0), and the 

electrical and/or fuel measurement readings, 

as appropriate. Begin the 24-hour simulated 

use test by withdrawing the volume specified 


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in the appropriate table in section 5.4 (i.e., 

Table III.1, Table III.2, Table III.3, or Table 

III.4, depending on the rated first-hour rating) 

for the first draw at the flow rate specified. 

Record the time when this first draw is 

initiated and assign it as the test elapsed time 

(t) of zero (0). Record the average storage tank 

and ambient temperature every minute 

throughout the 24-hour simulated use test. At 

the elapsed times specified in the applicable 

draw pattern table in section 5.4 for a 

particular draw pattern, initiate additional 

draws, removing the volume of hot water at 

the prescribed flow rate specified by the 

table. The maximum allowable deviation for 

any single draw is ± 0.25 gallons (1.9 liters). 

The quantity of water withdrawn during the 

last draw shall be increased or decreased as 

necessary such that the total volume of water 

withdrawn equals the prescribed daily 

amount for that draw pattern ± 1.0 gallon (± 

3.8 liters). 

All draws during the 24-hour simulated 

use test shall be made at the flow rates 

specified in the applicable draw pattern table 

in section 5.4, within a tolerance of ± 0.25 

gallons per minute (± 0.95 liters per minute). 

Measurements of the inlet and outlet 

temperatures shall be made 5 seconds after 

the draw is initiated and at every subsequent 

3-second interval throughout the duration of 

each draw. The arithmetic mean of the hot 

water discharge temperature and the cold 

water inlet temperature shall be determined 

for each draw (Tdel,i and Tin,i). Determine and 

record the net mass or volume removed (Mi

or Vi), as appropriate, after each draw. 

At the end of the first recovery period 

following the first draw, which may extend 

beyond subsequent draws, record the 

maximum mean tank temperature observed 

after cut-out, Tmax,1, and the energy 

consumed by an electric resistance, gas or 

oil-fired water heater (including electrical 

energy), from the beginning of the test, Qr. 

For heat pump water heaters, the total 

electrical energy consumed during the first 

recovery by the heat pump (including 

compressor, fan, controls, pump, etc.) and, if 

applicable, by the resistive element(s) shall 

be recorded as Qr. 

At the end of the recovery period that 

follows the draw notated in the applicable 

draw pattern table in section 5.4 as the end 

of the first draw cluster during the test, 

determine and record the total electrical 

energy and/or fossil fuel consumed since the 

beginning of the test, Qsu,0. In preparation for 

determining the energy consumed during 

standby, record the reading given on the 

electrical energy (watt-hour) meter, the gas 

meter, and/or the scale used to determine oil 

consumption, as appropriate. Record the 

maximum value of the mean tank 

temperature after cut-out as Tsu,0. The time at 

which this value is attained is the start of the 

standby period. At 1-minute intervals, record 

the mean tank temperature and the electric 

and/or fuel instrument readings until the 

next draw is initiated. Just prior to initiation 

of the next draw, record the mean tank 

temperature as Tsu,f. If the water heater is 

undergoing recovery when the next draw is 

initiated, record the mean tank temperature 

Tsu,f at the minute prior to the start of the 

recovery. The time at which this value occurs 

is the end of the standby period. Determine 

the total electrical energy and/or fossil fuel 

energy consumption from the beginning of 

the test to this time and record as Qsu,f. 

Record the time interval between the time at 

which the maximum mean tank temperature 

is observed after the final draw of the first 

draw cluster and the end of the standby 

period as tstby,1. Record the time during 

which water is not being withdrawn from the 

water heater during the entire 24-hour period 

as tstby,2. 

5.3 Instantaneous Gas and Electric Water 

Heaters 

5.3.1 Setting the Outlet Discharge 

Temperature. Initiate normal operation of the 

water heater at the full input rating for 

electric instantaneous water heaters and at 

the maximum firing rate specified by the 

manufacturer for gas instantaneous water 

heaters. Monitor the discharge water 

temperature and set to a value of 125 °F ± 

5 °F (51.7 °C ± 2.8 °C) in accordance with the 

manufacturer’s instructions. If the water 

heater is not capable of providing this 

discharge temperature when the flow rate is 

1.7 gallons ± 0.25 gallons per minute (7.6 

liters ± 0.95 liters per minute), then adjust 

the flow rate as necessary to achieve the 

specified discharge water temperature. 

5.3.2 Maximum gpm Rating Test for 

Instantaneous Water Heaters. Establish 

normal water heater operation at the full 

input rate for electric instantaneous water 

heaters and at the maximum firing rate for 

gas instantaneous water heaters with the 

discharge water temperature set in 

accordance with section 5.3.1. During the 10- 

minute test, either collect the withdrawn 

water for later measurement of the total mass 

removed, or alternatively, use a water meter 

to directly measure the water volume 

removed. 

After recording the scale or water meter 

reading, initiate water flow through the water 

heater, record the inlet and outlet water 

temperatures beginning 15 seconds after the 

start of the test and at subsequent 5-second 

intervals throughout the duration of the test. 

At the end of 10 minutes, turn off the water. 

Determine the mass of water collected, M10m, 

in pounds (kilograms), or the volume of 

water, V10m, in gallons (liters). 

5.3.3 24-hour Simulated Use Test for 

Instantaneous Water Heaters. 

5.3.3.1 Selection of Draw Pattern. The 

water heater will be tested under a draw 

profile that depends upon the rated 

maximum gpm rating obtained following the 

test prescribed in section 5.3.2. Four different 

patterns can be applied, and Table II shows 

which draw pattern is applied to a water 

heater based on its rated maximum gpm 

rating. 

TABLE II—DRAW PATTERN TO BE USED FOR INSTANTANEOUS WATER HEATER BASED ON RATED MAXIMUM GPM RATING

Rated maximum gpm rating 

greater than or equal to: . . . and rated maximum GPM rating less than: Draw pattern to be used in simulated use test 

0 ........................................... 1.7 ................................................................................... Point-of-Use (Table III.1). 

1.7 ........................................ 2.8 ................................................................................... Low-Usage (Table III.2). 

2.8 ........................................ 4 ...................................................................................... Medium-Usage (Table III.3). 

4 ........................................... No upper limit .................................................................. High-Usage (Table III.4). 

The draw patterns are provided in Tables 

III.1 through III.4 in section 5.4. Use the 

appropriate draw pattern when conducting 

the test sequence set forth in section 5.3.3.2. 

5.3.3.2 Test Sequence. Establish normal 

operation with the discharge water 

temperature at 125 °F ± 5 °F (51.7 °C ± 2.8 °C) 

and set the flow rate set as determined in 

section 5.2. Prior to commencement of the 

24-hour simulated use test, the unit shall 

remain in an idle state in which controls are 

active but no water is drawn through the unit 

for a period of one hour. With no draw 

occurring, record the reading given by the gas 

meter and/or the electrical energy meter as 

appropriate. Begin the 24-hour simulated use 

test by withdrawing the volume specified in 

Table III.1 through III.4 for the first draw at 

the flow rate specified. Record the time when 

this first draw is initiated and designate it as 

an elapsed time, t, of 0. At the elapsed times 

specified in Table III.1 through III.4 for a 

particular draw pattern, initiate additional 

draws, removing the volume of hot water at 

the prescribed flow rate specified in Table 

III.1 through III.4, with the maximum 

allowable deviation for any single draw being 

± 0.5 gallons (1.9 liters). The quantity of 

water drawn during the final draw shall be 

increased or decreased as necessary such that 

the total volume of water withdrawn equals 

the prescribed daily amount for that draw 

pattern ± 1.0 gallon (± 3.8 liters). 

Measurements of the inlet and outlet water 

temperatures shall be made 5 seconds after 

the draw is initiated and at every 3-second 

interval thereafter throughout the duration of 

the draw. The arithmetic mean of the hot 

water discharge temperature and the cold 

water inlet temperature shall be determined 

for each draw. Record the scale used to 

measure the mass of the withdrawn water or 

the water meter reading, as appropriate, after 

each draw. At the end of the recovery period 

following the first draw, determine and 

record the fossil fuel and/or electrical energy 

consumed, Qr. Following the final draw and 


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subsequent recovery, allow the water heater 

to remain in the standby mode until exactly 

24 hours have elapsed since the start of the 

test (i.e., since t = 0). At 24 hours, record the 

reading given by the gas meter and/or the 

electrical energy meter as appropriate. 

Determine the fossil fuel and/or electrical 

energy consumed during the entire 24-hour 

simulated use test and designate the quantity 

as Q. 

5.4 Draw Patterns. The draw patterns to 

be imposed during 24-hour simulated use 

tests are provided in Tables III.1 through 

III.4. Each water heater under test is to be 

subjected to one of the draw patterns based 

on its rated first-hour rating or rated 

maximum gpm rating as discussed in 

sections 5.2.5.1 and 5.3.3.1, respectively. 

Each draw pattern specifies the elapsed time 

in hours and minutes during the 24-hour test 

when a draw is to commence, the total 

volume of water in gallons (liters) that is to 

be removed during each draw, and the flow 

rate at which each draw is to be taken, in 

gallons (liters) per minute. 

TABLE III.1—POINT-OF-USE DRAW PATTERN

Draw No. 

Time during 

test 

[hh:mm] 

Volume 

[gallons (L)] 

Flow rate **

[gpm (Lpm)] 

1 * ................................................................................................................................................. 0:00 2.0 (7.6) 1 (3.8) 

2 * ................................................................................................................................................. 1:00 1.0 (3.8) 1 (3.8) 

3 * ................................................................................................................................................. 1:05 0.5 (1.9) 1 (3.8) 

4 * ................................................................................................................................................. 1:10 0.5 (1.9) 1 (3.8) 

5 * ................................................................................................................................................. 1:15 0.5 (1.9) 1 (3.8) 

6 ................................................................................................................................................... 8:00 1.0 (3.8) 1 (3.8) 

7 ................................................................................................................................................... 8:15 2.0 (7.6) 1 (3.8) 

8 ................................................................................................................................................... 9:00 1.5 (5.7) 1 (3.8) 

9 ................................................................................................................................................... 9:15 1.0 (3.8) 1 (3.8) 

Total Volume Drawn per Day: 10 gallons (38 L) 

* Denotes draws in first draw cluster. 

** Should the water heater have a rated maximum gpm rating less than 1 gpm (3.8 Lpm), then all draws shall be implemented at a flow rate 

equal to the rated maximum gpm rating 

TABLE III.2—LOW-USAGE DRAW PATTERN

Draw No. Time during 

test (hh:mm) 

Volume 

(gallons) 

Flow rate 

(gpm) 

1 * ................................................................................................................................................. 0:00 15.0 (56.8) 1.7 (6.4) 

2 * ................................................................................................................................................. 0:30 2.0 (7.6) 1 (3.8) 

3 * ................................................................................................................................................. 1:00 1.0 (3.8) 1 (3.8) 

4 ................................................................................................................................................... 10:30 6.0 (22.7) 1.7 (6.4) 

5 ................................................................................................................................................... 11:30 4.0 (15.1) 1.7 (6.4) 

6 ................................................................................................................................................... 12:00 1.0 (3.8) 1 (3.8) 

7 ................................................................................................................................................... 12:45 1.0 (3.8) 1 (3.8) 

8 ................................................................................................................................................... 12:50 1.0 (3.8) 1 (3.8) 

9 ................................................................................................................................................... 16:15 2.0 (7.6) 1 (3.8) 

10 ................................................................................................................................................. 16:45 2.0 (7.6) 1.7 (6.4) 

11 ................................................................................................................................................. 17:00 3.0 (11.4) 1.7 (6.4) 

Total Volume Drawn per Day: 38 gallons (144 L) 

* Denotes draws in first draw cluster. 

TABLE III.3—MEDIUM-USAGE DRAW PATTERN

Draw No. 

Time during 

test 

(hh:mm) 

Volume 

(gallons) 

Flow rate 

(gpm) 

1 * ................................................................................................................................................. 0:00 15.0 (56.8) 1.7 (6.4) 

2 * ................................................................................................................................................. 0:30 2.0 (7.6) 1 (3.8) 

3 * ................................................................................................................................................. 1:40 9.0 (34.1) 1.7 (6.4) 

4 ................................................................................................................................................... 10:30 9.0 (34.1) 1.7 (6.4) 

5 ................................................................................................................................................... 11:30 5.0 (18.9) 1.7 (6.4) 

6 ................................................................................................................................................... 12:00 1.0 (3.8) 1 (3.8) 

7 ................................................................................................................................................... 12:45 1.0 (3.8) 1 (3.8) 

8 ................................................................................................................................................... 12:50 1.0 (3.8) 1 (3.8) 

9 ................................................................................................................................................... 16:00 1.0 (3.8) 1 (3.8) 

10 ................................................................................................................................................. 16:15 2.0 (7.6) 1 (3.8) 

11 ................................................................................................................................................. 16:45 2.0 (7.6) 1.7 (6.4) 

12 ................................................................................................................................................. 17:00 7.0 (26.5) 1.7 (6.4) 

Total Volume Drawn Per Day: 55 gallons (208 L) 

* Denotes draws in first draw cluster. 


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TABLE III.4—HIGH-USAGE DRAW PATTERN

Draw No. 

Time during 

test 

(hh:mm) 

Volume 

(gallons) 

Flow rate 

(gpm) 

1 * ................................................................................................................................................. 0:00 27.0 (102) 3 (11.4) 

2 * ................................................................................................................................................. 0:30 2.0 (7.6) 1 (3.8) 

3 * ................................................................................................................................................. 0:40 1.0 (3.8) 1 (3.8) 

4 * ................................................................................................................................................. 1:40 9.0 (34.1) 1.7 (6.4) 

5 ................................................................................................................................................... 10:30 15.0 (56.8) 3 (11.4) 

6 ................................................................................................................................................... 11:30 5.0 (18.9) 1.7 (6.4) 

7 ................................................................................................................................................... 12:00 1.0 (3.8) 1 (3.8) 

8 ................................................................................................................................................... 12:45 1.0 (3.8) 1 (3.8) 

9 ................................................................................................................................................... 12:50 1.0 (3.8) 1 (3.8) 

10 ................................................................................................................................................. 16:00 2.0 (7.6) 1 (3.8) 

11 ................................................................................................................................................. 16:15 2.0 (7.6) 1 (3.8) 

12 ................................................................................................................................................. 16:30 2.0 (7.6) 1.7 (6.4) 

13 ................................................................................................................................................. 16:45 2.0 (7.6) 1.7 (6.4) 

14 ................................................................................................................................................. 17:00 14.0 (53.0) 3 (11.4) 

Total Volume Drawn Per Day: 84 gallons (318 L) 

* Denotes draws in first draw cluster. 

6. Computations 

6.1 Storage Tank and Heat Pump Water 

Heaters 

6.1.1 Storage Tank Capacity. The storage 

tank capacity, Vst, is computed using the 

following: 

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) 

r = the density of water used to fill the tank 

measured at the temperature of the 

water, lb/gal (kg/L) 

6.1.2 First-Hour Rating Computation. For 

the case in which the final draw is initiated 

at or prior to an elapsed time of one hour, 

the first-hour rating, Fhr, shall be computed 

using, 

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, 

Where: 

M*i = the mass of water removed during the 

ith draw of the first-hour rating test, lb 

(kg). 

r = the water density corresponding to the 

average outlet temperature measured 

during the ith draw, (T*del,i), lb/gal (kg/ 

L). 

For the case in which a draw is not in 

progress at the elapsed time of one hour and 

a final draw is imposed at the elapsed time 

of one hour, the first-hour rating shall be 

calculated using 

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, °F (°C). 

T* del,n = the average water outlet temperature 

measured during the nth (final) draw of 

the first-hour rating test, °F (°C). 

T*min,n-1 = the minimum water outlet 

temperature measured during the (n-1)th 

draw of the first-hour rating test, °F (°C). 

6.1.3 Recovery Efficiency. The recovery 

efficiency for gas, oil, and heat pump storagetype water heaters, hr, is computed as: 

Where: 

M1 = total mass removed from the start of the 

24-hour simulated use test to the end of 

the first recovery period, lb (kg), or, if the 

volume of water is being measured, 

M1 = V1r1

Where: 

V1 = total volume removed from the start of 

the 24-hour simulated use test to the end 

of the first recovery period, gal (L). 

r1 = density of the water at the water 

temperature measured at the point where 

the flow volume is measured, lb/gal (kg/ 

L). 

Cp1 = specific heat of the withdrawn water 

evaluated at (Tdel,1 + Tin,1)/2, Btu/(lb·°F) 

(kJ/(kg·°C)) 

Tdel,1 = average water outlet temperature 

measured during the draws from the start 

of the 24-hour simulated use test to the 

end of the first recovery period, °F (°C). 


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Tin,1 = average water inlet temperature 

measured during the draws from the start 

of the 24-hour simulated use test to the 

end of the first recovery period, °F (°C). 

Vst = as defined in section 6.1.1. 

r2 = density of stored hot water evaluated at 

(Tmax,1 + To)/2, lb/gal (kg/L). 

Cp2 = specific heat of stored hot water 

evaluated at (Tmax,1 + To)/2, Btu/(lb·°F) 

(kJ/(kg·°C). 

Tmax,1 = maximum mean tank temperature 

recorded after cut-out following the first 

recovery of the 24-hour simulated use 

test, °F (°C). 

To = maximum mean tank temperature 

recorded prior to the first draw of the 24- 

hour simulated use test, °F (°C). 

Qr = the total energy used by the water heater 

between cut-out prior to the first draw 

and cut-out following the first recovery 

period, including auxiliary energy such 

as pilot lights, pumps, fans, etc., Btu (kJ). 

(Electrical auxiliary energy shall be 

converted to thermal energy using the 

following conversion: 1 kWh = 3412 

Btu). 

The recovery efficiency for electric 

water heaters with immersed heating 

elements is assumed to be 98%. 

6.1.4 Hourly Standby Losses. The 

energy consumed as part of the standby 

loss test of the 24-hour simulated use 

test, Qstby, is computed as: 

Qstby = Qsu,f¥Qsu,0

Where: 

Qsu,0 = cumulative energy consumption of the 

water heater from the start of the 24-hour 

simulated use test to the time at which 

the maximum mean tank temperature is 

attained after the recovery following the 

end of the first draw cluster, Btu (kJ). 

Qsu,f = cumulative energy consumption of the 

water heater from the start of the 24-hour 

simulated use test to the minute prior to 

the start of the draw following the end 

of the first draw cluster or the minute 

prior to a recovery occurring at the start 

of the draw following the end of the first 

draw cluster, Btu (kJ). 

The hourly standby energy losses are 

computed as: 

Where: 

Qhr = the hourly standby energy losses of the 

water heater, Btu/h (kJ/h). 

Vst = as defined in section 6.1.1. 

r = density of stored hot water, (Tsu,f + Tsu,0)/ 

2, lb/gal (kg/L). 

Cp = specific heat of the stored water, (Tsu,f

+ Tsu,0)/2, Btu/(lb·F), (kJ/(kg·K)) 

Tsu,f = the mean tank temperature observed 

at the minute prior to the start of the 

draw following the first draw cluster or 

the minute prior to a recovery occurring 

at the start of the draw following the end 

of the first draw cluster, °F (°C). 

Tsu,0 = the maximum mean tank temperature 

observed after the first recovery 

following the final draw of the first draw 

cluster, °F (°C). 

hr = as defined in section 6.1.3. 

tstby,1 = elapsed time between the time at 

which the maximum mean tank 

temperature is observed after the first 

draw cluster and the minute prior to the 

start of the first draw following the end 

of the first draw cluster of the 24-hour 

simulated use test or the minute prior to 

a recovery occurring at the start of the 

draw following the end of the first draw 

cluster, h. 

The standby heat loss coefficient for 

the tank is computed as: 

Where: 

UA = standby heat loss coefficient of the 

storage tank, Btu/(h·°F), (kJ/(h·°C). 

Tt,stby,1 = overall average storage tank 

temperature between the time when the 

maximum mean tank temperature is 

observed after cut-out following the first 

draw cluster and the minute prior to 

commencement of the next draw 

following the first draw cluster of the 24- 

hour simulated use test, °F (°C). 

Ta,stby,1 = overall average ambient temperature 

between the time when the maximum 

mean tank temperature is observed after 

cut-out following the first draw cluster 

and the minute prior to commencement 

of the next draw following the first draw 

cluster of the 24-hour simulated use test, 

°F (°C). 

6.1.5 Daily Water Heating Energy 

Consumption. The daily water heating 

energy consumption, Qd, is computed 

as: 

Where: 

Q = Qf + Qe = total energy used by the water 

heater during the 24-hour simulated use 

test, including auxiliary energy such as 

pilot lights, pumps, fans, etc., Btu (kJ). 

(Electrical energy shall be converted to 

thermal energy using the following 

conversion: 1kWh = 3412 Btu.) 

Qf = total fossil fuel energy used by the water 

heater during the 24-hour simulated use 

test, Btu (kJ). 

Qe = total electrical energy used during the 

24-hour simulated use test, Btu (kJ). 

Vst = as defined in section 6.1.1. 

r = density of the stored hot water, evaluated 

at (T24 + T0)/2, lb/gal (kg/L) 

Cp = specific heat of the stored water, 

evaluated at (T24 + T0)/2, Btu/(lb·F), (kJ/ 

(kg·K)). 

T24 = mean tank temperature at the end of the 

24-hour simulated use test, °F (°C). 

T0 = mean tank temperature at the beginning 

of the 24-hour simulated use test, 

recorded one minute before the first 

draw is initiated, °F (°C). 

hr = as defined in section 6.1.3. 

6.1.6 Adjusted Daily Water Heating 

Energy Consumption. The adjusted 

daily water heating energy 

consumption, Qda, takes into account 

that the temperature difference between 

the storage tank and surrounding 

ambient air may not be the nominal 

value of 57.5 °F (125 °F¥67.5 °F) or 

32.0 °C (51.7 °C¥19.7 °C) due to the 10 

°F (5.6 °C) allowable variation in storage 

tank temperature, 125 °F ± 5 °F (51.7 °C 

± 2.8 °C), and the 5 °F (2.8 °C) allowable 

variation in surrounding ambient 

temperature 65 °F (18.3 °C) to 70 °C 

(21.1 °C). The adjusted daily water 

heating energy consumption is 

computed as: 

Where: 

Qda = the adjusted daily water heating energy 

consumption, Btu (kJ). 

Qd = as defined in section 6.1.5. 

Tstby,2 = the mean tank temperature during 

the total standby portion, tstby,2, of the 

24-hour test, °F (°C). 

Ta,stby,2 = the average ambient temperature 

during the total standby portion, tstby,2, of 

the 24-hour test, °F (°C). 

UA = as defined in section 6.1.4. 


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tstby,2 = the number of hours during the 24- 

hour simulated test when water is not 

being withdrawn from the water heater. 

A modification is also needed to take into 

account that the temperature difference 

between the outlet water temperature and 

supply water temperature may not be 

equivalent to the nominal value of 67 °F (125 

°F¥58 °F) or 37.3 °C (51.7 °C¥14.4 °C). The 

following equations adjust the experimental 

data to a nominal 67 °F (37.3 °C) temperature 

rise. 

The energy used to heat water, Btu/day (kJ/ 

day), may be computed as: 

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·°F) (kJ/(kg·°C)). 

Tdel,i = the average water outlet temperature 

measured during the ith draw (i = 1 to 

N), °F (°C). 

Tin,i = the average water inlet temperature 

measured during the ith draw (i = 1 to 

N), °F (°C). 

hr = as defined in section 6.1.3. 

The energy required to heat the same 

quantity of water over a 67 °F (37.3 °C) 

temperature rise, Btu/day (kJ/day), is: 

The difference between these two values is: 

QHWD = QHW,67 °F¥QHW

or QHWD = QHW,37.3 °C¥QHW

This difference (QHWD) must be added to the 

adjusted daily water heating energy 

consumption value. Thus, the daily energy 

consumption value which takes into account 

that the temperature difference between the 

storage tank and ambient temperature may 

not be 57.5 °F (32.0 °C) and that the 

temperature rise across the storage tank may 

not be 67 °F (37.3 °C) is: Qdm = Qda + QHWD

6.1.7 Energy Factor. The energy factor, Ef, 

is computed as: 

Where: 

N = total number of draws in the draw 

pattern 

Qdm = the modified daily water heating 

energy consumption as computed in 

accordance with section 6.1.6, Btu (kJ) 

Mi = the mass withdrawn for the ith draw (i 

= 1 to N), lb (kg) 

Cpi = the specific heat of the water of the ith 

draw, evaluated at (125 °F + 58 °F)/2 = 

91.5 °F ((51.7°C + 14.4°C)/2 = 33 °C), 

Btu/(lb·°F) (kJ/(kg·°C)). 

6.1.8 Annual Energy Consumption. The 

annual energy consumption for storage-type 

and heat pump water heaters is computed as: 

Where: 

Ef = the energy factor as computed in 

accordance with section 6.1.8 

365 = the number of days in a year 

V = the volume of hot water drawn during 

the applicable draw pattern, gallons 

= 10 for the point-of-use draw pattern 

= 38 for the low usage draw pattern 

= 55 for the medium usage draw pattern 

= 84 for high usage draw pattern 

r = 8.24 lbm/gallon, the density of water at 

125 °F 

CP = 1.00 Btu/lbm°F, the specific heat of 

water at 91.5 °F 

67 = the nominal temperature difference 

between inlet and outlet water 

6.1.9 Annual Electrical Energy 

Consumption. The annual electrical energy 

consumption in kilowatt-hours for storagetype and heat pump water heaters, Eannual,e, is 

computed as: 

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

Where: 

Eannual = the annual energy consumption as 

determined in accordance with section 

6.1.8, Btu (kJ) 

Qe = the daily electrical energy consumption 

as defined in section 6.1.5, Btu (kJ). 

Q = total energy used by the water heater 

during the 24-hour simulated use test in 

accordance with section 6.1.5, Btu (kJ) 

3412 = conversion factor from Btu to kWh 

6.1.10 Annual Fossil Fuel Energy 

Consumption. The annual fossil fuel energy 

consumption for storage-type and heat pump 

water heaters, Eannual,f, is computed as: 


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Eannual,f = Eannual¥(Eannual,e × 3412) 

Where: 

Eannual = the annual energy consumption as 

determined in accordance with section 

6.1.8, Btu (kJ) 

Eannual,e = the annual electrical energy 

consumption as determined in 

accordance with section 6.1.9, kWh 

3412 = conversion factor from kWh to Btu 

6.2 Instantaneous Water Heaters. 

6.2.1 Maximum gpm (L/min) Rating 

Computation. Compute the maximum gpm 

(L/min) rating, Fmax, as: 

which may be expressed as: 

Where: 

M10m = the mass of water collected during the 

10-minute test, lb (kg). 

Tdel = the average delivery temperature, °F 

(°C). 

Tin = the average inlet temperature, °F (°C). 

r = the density of water at the average 

delivery temperature, lb/gal (kg/L). 

If a water meter is used, the maximum gpm 

(L/min) rating is computed as: 

Where: 

V10m = the volume of water measured during 

the 10-minute test, gal (L). 

Tdel = as defined in this section. 

Tin = as defined in this section. 

6.2.2 Recovery Efficiency. The recovery 

efficiency, hr, is computed as: 

Where: 

M1 = total mass removed during the first 

draw of the 24-hour simulated use test, 

lb (kg), or, if the volume of water is being 

measured, 

M1 = V1 · r 

Where: 

V1 = total volume removed during the first 

draw of the 24-hour simulated use test, 

gal (L). 

r = density of the water at the water 

temperature measured at the point where 

the flow volume is measured, lb/gal (kg/ 

L). 

Cp1 = specific heat of the withdrawn water, 

(Tdel,1 ¥ Tin,1)/2, Btu/(lb·°F) (kJ/(kg·°C)). 

Tdel,1 = average water outlet temperature 

measured during the first draw of the 24- 

hour simulated use test, °F (°C). 

Tin,1 = average water inlet temperature 

measured during the first draw of the 24- 

hour simulated use test, °F (°C). 

Qr = the total energy used by the water heater 

between cut-out prior to the first draw 

and cut-out following the first draw, 

including auxiliary energy such as pilot 

lights, pumps, fans, etc., Btu (kJ). 

(Electrical auxiliary energy shall be 

converted to thermal energy using the 

following conversion: 1 kWh = 3412 

Btu.) 

6.2.3 Daily Water Heating Energy 

Consumption. The daily water heating energy 

consumption, Qd, is computed as: 

Qd = Q 

Where: 

Q = Qf + Qe = the energy used by the 

instantaneous water heater during the 

24-hour simulated use test. 

Qf = total fossil fuel energy used by the water 

heater during the 24-hour simulated use 

test, Btu (kJ). 

Qe = total electrical energy used during the 

24-hour simulated use test, Btu (kJ). 

A modification is needed to take into 

account that the temperature difference 

between the outlet water temperature and 

supply water temperature may not be 

equivalent to the nominal value of 67 °F (125 

°F ¥ 58 °F) or 37.3 °C (51.7 °C ¥ 14.4 °C). 

The following equations adjust the 

experimental data to a nominal 67 °F (37.3 

°C) temperature rise. 

The energy used to heat water may be 

computed as: 

Where: 

N = total number of draws in the draw 

pattern 

Mi = the mass withdrawn for the ith draw (i 

= 1 to N), lb (kg) 


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Cpi = the specific heat of the water of the ith 

draw evaluated at (Tdel,i + Tin,i)/2, Btu/ 

(lb·°F) (kJ/(kg·°C)). 

Tdel,i = the average water outlet temperature 

measured during the ith draw (i = 1 to 

N), °F (°C). 

Tin,i = the average water inlet temperature 

measured during the ith draw (i = 1 to 

N), °F (°C). 

hr = as defined in section 6.2.2. 

The energy required to heat the same 

quantity of water over a 67 °F (37.3 °C) 

temperature rise is: 

Where: 

N = total number of draws in the draw 

pattern 

Mi = the mass withdrawn during the ith 

draw, lb (kg) 

Cpi = the specific heat of water of the ith 

draw, Btu/(lb·°F) (kJ/(kg·°C)) 

hr = as defined in section 6.2.2. 

The difference between these two values is: 

QHWD = QHW,67°F ¥ QHW

or QHWD = QHW,37.3°C ¥ QHW

This difference (QHWD) must be added to the 

adjusted daily water heating energy 

consumption value. Thus, the daily energy 

consumption value, which takes into account 

that the temperature difference between the 

storage tank and ambient temperature may 

not be 57.5 °F (32.0 °C) and that the 

temperature rise across the storage tank may 

not be 67 °F (37.3 °C), is: 

Qdm = Qd + QHWD

6.2.4 Energy Factor. The energy factor, Ef, 

is computed as: 

Where: 

N = total number of draws in the draw 

pattern 

Qdm = the modified daily water heating 

energy consumption as computed in 

accordance with section 6.2.3, Btu (kJ) 

Mi = the mass withdrawn for the ith draw (i 

= 1 to N), lb (kg) 

Cpi = the specific heat of the water at the ith 

draw, evaluated at (125 °F + 58 °F)/2 = 

91.5 °F ((51.7 °C + 14.4 °C)/2 = 33 °C), 

Btu/(lb· °F) (kJ/(kg· °C)). 

6.2.5 Annual Energy Consumption. The 

annual energy consumption for 

instantaneous-type water heaters, Eannual, is 

computed as: 

Where: 

Ef = the energy factor as computed in 

accordance with section 6.2.4 

365 = the number of days in a year. 

V = the volume of hot water drawn during 

the applicable draw pattern, gallons 

= 10 for the point-of-use draw pattern 

= 38 for the low usage draw pattern 

= 55 for the medium usage draw pattern 

= 84 for high usage draw pattern 

r = 8.24 lbm/gallon, the density of water at 

125 °F 

CP = 1.00 Btu/lbm °F, the specific heat of 

water at 91.5 °F 

67 = the nominal temperature difference 

between inlet and outlet water 

6.2.6 Annual Electrical Energy 

Consumption. The annual electrical energy 

consumption in kilowatt-hours for 

instantaneous-type water heaters, Eannual, e, is 

computed as: 

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

Where: 

Qe = the daily electrical energy consumption 

as defined in section 6.2.3, Btu (kJ) 

Eannual = the annual energy consumption as 

determined in accordance with section 

6.2.5, Btu (kJ) 

Q = total energy used by the water heater 

during the 24-hour simulated use test in 

accordance with section 6.2.3, Btu (kJ) 

Qdm = the modified daily water heating 

energy consumption as computed in 

accordance with section 6.2.3, Btu (kJ) 

3412 = conversion factor from Btu to kWh 

6.2.7 Annual Fossil Fuel Energy 

Consumption. The annual fossil fuel energy 

consumption for instantaneous-type water 

heaters, Eannual,f, is computed as: 

Eannual,f = Eannual ¥ (Eannual,e × 3412) 

Where: 

Eannual,e = the annual electrical energy 

consumption as defined in section 6.2.6, 

kWh. 

Eannual = the annual energy consumption as 

defined in section 6.2.5, Btu (kJ) 

3412 = conversion factor from kWh to Btu 


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* * * * * 

■ 10. Section 430.32 is amended by 

revising paragraph (d) to read as 

follows: 

§ 430.32 Energy and water conservation 

standards and their compliance dates. 

* * * * * 

(d) Water heaters. The energy factor of 

water heaters shall not be less than the 

following for products manufactured on 

or after the indicated dates. 

Product class Storage volume Energy factor as of January 20, 2004 Energy factor as of April 16, 2015 

Gas-fired Storage Water 

Heater.

≥ 20 gallons and ≤ 100 

gallons.

0.67¥(0.0019 × Rated 

Storage Volume in gallons).

For tanks with a Rated Storage Volume at or below 55 

gallons: EF = 0.675¥(0.0015 × Rated Storage Volume in gallons). 

For tanks with a Rated Storage Volume above 55 gallons: EF = 0.8012¥(0.00078 × Rated Storage Volume in gallons). 

Oil-fired Storage Water 

Heater.

≤ 50 gallons ....................... 0.59¥(0.0019 × Rated 

Storage Volume in gallons).

EF = 0.68¥(0.0019 × Rated Storage Volume in gallons). 

Electric Storage Water Heater.≥ 20 gallons and ≤ 120 

gallons.

0.97¥(0.00132 × Rated 

Storage Volume in gallons).

For tanks with a Rated Storage Volume at or below 55 

gallons: EF = 0.960¥(0.0003 × Rated Storage Volume in gallons). For tanks with a Rated Storage 

Volume above 55 gallons: EF = 2.057¥(0.00113 × 

Rated Storage Volume in gallons). 

Tabletop Water Heater ........ ≥ 20 gallons and ≤ 120 

gallons.

0.93¥(0.00132 × Rated 

Storage Volume in gallons).

EF = 0.93¥(0.00132 × Rated Storage Volume in gallons). 

Instantaneous Gas-fired 

Water Heater.

< 2 gallons ......................... 0.62¥(0.0019 × Rated 

Storage Volume in gallons).

EF = 0.82¥(0.0019 × Rated Storage Volume in gallons). 

Instantaneous Electric Water 

Heater.

< 2 gallons ......................... 0.93¥(0.00132 × Rated 

Storage Volume in gallons).

EF = 0.93¥(0.00132 × Rated Storage Volume in gallons). 

Note: The Rated Storage Volume equals the water storage capacity of a water heater, in gallons, as certified by the manufacturer. 

Exclusions. The energy conservation 

standards shown in this paragraph do 

not apply to the following types of water 

heaters: gas-fired, oil-fired, and electric 

water heaters at or above 2 gallons 

storage volume and below 20 gallons 

storage volume; gas-fired water heaters 

above 100 gallons storage volume; oilfired water heaters above 50 gallons 

storage volume; electric water heaters 

above 120 gallons storage volume; gasfired instantaneous water heaters at or 

below 50,000 Btu/h. 

* * * * * 

PART 431—ENERGY EFFICIENCY 

PROGRAM FOR CERTAIN 

COMMERCIAL AND INDUSTRIAL 

EQUIPMENT 

■ 11. The authority citation for part 431 

continues to read as follows: 

Authority: 42 U.S.C. 6291–6317. 

■ 12. Section 431.102 is amended by 

adding the definition of ‘‘Light 

commercial water heater,’’ in 

alphabetical order, to read as follows: 

§ 431.102 Definitions concerning 

commercial water heaters, hot water supply 

boilers, and unfired hot water storage 

tanks. 

* * * * * 

Light commercial water heater means 

any gas-fired, electric, or oil storage or 

instantaneous commercial water heater 

that meets the following conditions: 

(1) For models requiring electricity, 

uses single-phase external power 

supply; 

(2) Is not capable of delivering hot 

water at temperatures of 180 °F or 

above; and 

(3) Does not bear a Code Symbol 

Stamp signifying compliance with the 

requirements of the ASME Boiler and 

Pressure Vessel Code. 

* * * * * 

■ 13. In § 431.106, paragraph (b), Table 

2, is revised to read as follows: 

§ 431.106 Uniform test method for the 

measurement of energy efficiency of 

commercial water heaters and hot water 

supply boilers (other than commercial heat 

pump water heaters). 

* * * * * 

(b) * * * 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 66247 

TABLE 2 TO § 431.106—TEST PROCEDURES FOR COMMERCIAL WATER HEATERS AND HOT WATER SUPPLY BOILERS

[Other than commercial heat pump water heaters] 

Equipment type Energy efficiency 

descriptor 

Use test set-up, 

equipment, and 

procedures in 

subsection labeled 

‘‘Method of Test’’ of 

Test procedure 

required for 

compliance on and 

after 

With these additional stipulations 

Light Commercial 

Water Heater.

Energy Factor ............ 10 CFR 430, Subpt. 

B, App. E.

(insert date 365 days 

after publication of 

the final rule in the 

Federal Register 

that establishes a 

conversion factor, or 

December 31, 2015, 

whichever is later).

None. 

Gas-fired Storage and 

Instantaneous 

Water Heaters and 

Hot Water Supply 

Boilers*.

Thermal Efficiency .....

Standby Loss .............

ANSI Z21.10.3– 

2011**, Exhibit G1.

ANSI Z21.10.3– 

2011**, Exhibit G2.

May 13, 2013 .............

May 13, 2013. 

A. For all products, the duration of the standby loss test shall be until whichever of the 

following occurs first after you begin to 

measure the fuel and/or electric consumption: (1) The first cutout after 24 hours or 

(2) 48 hours, if the water heater is not in 

the heating mode at that time. 

Oil-fired Storage and 

Instantaneous 

Water Heaters and 

Hot Water Supply 

Boilers*.

Thermal Efficiency .....

Standby Loss .............

ANSI Z21.10.3– 

2011**, Exhibit G1.

ANSI Z21.10.3– 

2011**, Exhibit G2.

May 13, 2013 .............

May 13, 2013. 

B. For oil and gas products, the standby loss 

in Btu per hour must be calculated as follows: SL (Btu per hour) = S (% per hour) × 

8.25 (Btu/gal-F) × Measured Volume (gal) 

× 70 (degrees F). 

Electric Storage and 

Instantaneous 

Water Heaters.

Standby Loss ............. ANSI Z21.10.3– 

2011**, Exhibit G2.

May 13, 2013 ............. C. For oil-fired products, apply the following 

in conducting the thermal efficiency and 

standby loss tests: (1) Venting Requirements—Connect a vertical length of flue 

pipe to the flue gas outlet of sufficient 

height so as to meet the minimum draft 

specified by the manufacturer. (2) Oil Supply—Adjust the burner rate so that: (a) 

The hourly Btu input rate lies within ±2 

percent of the manufacturer’s specified 

input rate, (b) the CO2 reading shows the 

value specified by the manufacturer, (c) 

smoke in the flue does not exceed No. 1 

smoke as measured by the procedure in 

ASTM–D–2156–80, and (d) fuel pump 

pressure lies within ±10 percent of manufacturer’s specifications. 

D. For electric products, apply the following 

in conducting the standby loss test: (1) Assume that the thermal efficiency (Et) of 

electric water heaters with immersed heating elements is 98 percent. (2) Maintain 

the electrical supply voltage to within ±5 

percent of the center of the voltage range 

specified on the water heater nameplate. 

(3) If the set up includes multiple adjustable thermostats, set the highest one first 

to yield a maximum water temperature in 

the specified range as measured by the 

topmost tank thermocouple. Then set the 

lower thermostat(s) to yield a maximum 

mean tank temperature within the specified range. 

E. Install water-tube water heaters as shown 

in Figure 2, ‘‘Arrangement for Testing 

Water-tube Type Instantaneous and Circulating Water Heaters.’’ 

* As to hot water supply boilers with a capacity of less than 10 gallons, these test methods become mandatory on October 21, 2005. Prior to 

that time, you may use for these products either (1) these test methods if you rate the product for thermal efficiency, or (2) the test methods in 

Subpart E if you rate the product for combustion efficiency as a commercial packaged boiler. 

** Incorporated by reference, see § 431.105. 

■ 14. Section 431.107 is added to read 

as follows: 

§ 431.107 Uniform test method for the 

measurement of energy efficiency of 

commercial heat pump water heaters. 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3
66248 Federal Register / Vol. 78, No. 213 / Monday, November 4, 2013 / Proposed Rules 

TABLE 1 TO § 431.107—TEST PROCEDURES FOR COMMERCIAL HEAT PUMP WATER HEATERS

Equipment type Energy efficiency 

descriptor 

Use test set-up, 

equipment, and 

procedures in 

subsection labeled 

‘‘Method of Test’’ of 

Test procedure required for compliance on 

and after 

Light Commercial Heat Pump Water Heater 

with Integrated Storage Tank.

Energy Factor ......... 10 CFR 430, Subpt. B, 

App. E.

(insert date 365 days after publication of the 

final rule in the Federal Register that establishes a conversion factor, or December 

31, 2015, whichever is later) 

All Other Types .................................................. [Reserved] ............... [Reserved] .................. [Reserved] 

[FR Doc. 2013–26268 Filed 11–1–13; 8:45 am] 

BILLING CODE 6450–01–P 


EMCDONALD on DSK67QTVN1PROD with PROPOSALS3