Wednesday

October 17, 1990

- =

Part II

Department of -- _ Energy

Office of Conservation and Renewable

Energy

10 CFR Part 430

Energy Conservation Program for

Consumer Products; Final Rule Regarding

Test Procedures and Energy

Conservation Standards for Water

Heaters

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S~51999 

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OOOI(OO)(I6-OCT -90-14:02:45) 

Wednesday 

October 17 , 1990 

Part HI 

Depa·rtment of 

Energy 

Office of Conservation and Renewable 

Energy 

10 CFR Part 430 

Energy Conservation Program for 

Consumer Products; Final Rule Regarding 

Test Procedures and" Energy 

Conservation Standards for Water 

Heaters 

F4717.FMT ... [16.32) ... l-07 -88 
42162 Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

DEPARTMENT OF ENERGY Forrestal Building, Mail Station. GC- Section 323(e) of the Act requires DOE

12, 1000 Independence Avenue SW., to determine to what extent, if any, a Office of Conservation and Washington, DC 20585, (202) 586-9507 proposed test procedure would alter the

Renewable Energy SUPPLEMENTARY INFORMATION: measured energy efficiency or measured

energy use of any covered product as

10 CFR 430 Part I. Background determined under the existing test

[Docket No. CAS-RM-79-105] A. Program Requirements procedure. If DOE determines that an

Part B of title III of the Energy Policy amended test procedure would alter the

Energy Conservation Program for d Conservation Ameasured efficiency or measured energy

Consumer Products; Final Rule Law 94-163, as amended bythe National use of a covered product DOE is

Regarding Test Procedures and Energy Conservation Policy Act required to amend the related energy

Energy Conservation Standards for (NECPA) Public Law 95619, the conservation standard accordingly. In

Water Heaters National Appliance Energy determining the amended standard,

AGENCY: Office of Conservation and Conservation Act (NAECA) of 1987, OE is required to measure the energy

Renewable Energy, Department of Public Law 100-12, and he National efficiency or energy use of

Ene abeEegrgy. Dp n oAppliance Energy Conservation representative samples of covered

a^'on .i .Final », Amendments of 1988 (NAECA 1988), products which minimally comply with ACTION: Final rule. Public Law 100-357, created the Energy the existing standard. The average

SUMMARY: The Energy Conservation Conservation Program for Consumer efficiency of these representative

Program for Consumer Products is Products other than Automobiles samples, tested using the amended test

conducted under the Energy Policy and (Program).I The thirteen consumer pocdure, constitutes the amended

Conservation Act, as amended. Energy products currently subject to thisstandard. Section 323(e)(2).

conservation standards for most types program (often referred to hereafter as B. Test Procedures

of major household appliances, 'covered products") include water

including water heaters, are among the heaters, the subject of today's The initial water heater test including water heaters, are among the heat hu t o procedures were prescribed by notice

required Program elements. The rulemaking.tresere pr b

legislation also requires the Department Under the Act, the Program consists iued September 27, 1977. 42 FR 54110

to establish standard methods of testing essentially of three parts: testing, (October 4, 1977). These original

covered products. In the case of any labeling, and Federal energy procedures coupled laboratory tests and coveedproducs.Inecason labeling. and Federal ocedures coupled laboratory tests and

amended test procedure, moreover, the conservation standards. The calculations to obtain estimates of

Department must determine to what Department of Energy (DOE or energy efficiency for storage type

extent the amended test procedure Department), in consultation with the electric, gas and oil water heaters. The

would alter the measured efficiency of National Institute of Standards and laboratory tests consisted of a cold

the related energy conservation Technology (NIST) (formerly National start recovery efficiency test," which

standard and make appropriate Bureau of Standards), is required to measured the ability of a water heater to

corrections to the standard. amend or establish new test procedures heat cold water, and a "standby loss

The purposes of the final rule as appropriate for each of the covered test," which measured the energy loss of

announced today are (i) to improve and producfs. Section 323. The purpose of a waer heater when not providing

refine the test procedure for water the test procedures is to produce test heated water. Recovery efficiency and

heaters and (ii) to amend the energy results which measure the energy percent standby loss are then

conservation standards for electric efficiency, energy use, or estimated mthematically combined in the

water heaters in order to reflect the annual operating cost of a covered calculations to obtain an energy factor,

changes in measured efficiency caused product during a representative average DOE's overall measure of water heater

by the revised test procedure. There is use cycle or period of use and shall not efficiency. Also, the original procedures

no change to the standard for gas and be unduly burdensome to conduct,included calculations for determining

oil water heaters resulting from the Section 323(u)(3). A test procedure is not the annual energy consumption and

revised test procedure. required if DOE determines by rule that annual operating costs. DOE amended

In addition, today's rule also corrects one cannot be developed. Section the notice water issued heater August test procedures by 30,1979, in order to the effective date of standards for 323(d)(1). One hundred and eighty days notice issued August 30,1979, in order to

mobile home furnaces in § 430.32(e) that after a test procedure for a product is prescribe a "measure of a water heater's

was incorrectly published on February adopted, no manufacturer may represent useful capatycaled first hour rating

7, 1989, 54 FR 6077. The correct effective the energy consumption of, or the cost of whee useful capacity was the maximum

date is September 1, 1990. energy consumed by, the product except hourly demand which could be met by

nDATES: The effective date for this as reflected in tests conducted according the water heater. 44 FR 52632

d cument is April 15, 1991. The effective to the DOE procedure. Section 323(c)(2). (September 7.1979).

date of standards for mobile home However, the one hundred and eighty By notice published in the Federal

furnaces s in 430.32(e) is September 1 day period referred to in section Register on February 8, 1984, (1984

e1990. n 403()sSetmr1 323(c)(2) may be extended for a period proposal), DOE proposed to amend its

of up to an additional one hundred and test ocedures for water heaters. 49 FR

FOR FURTHER INFORMATION CONTACT: eighty days if the Secretary determines 4870. ;he purpose of the 1984 proposal

Carl E. Adams, U.S. Department of that the requirements of section 323(c)(2) was threefold: First, to extend coverage

Energy, Office of Conservation and would impose undue burden. Section of the test procedures to heat pump

Rene.vable Energy, Forrestal Building. 323(c)(3). Test procedures appearat 10 water heaters, a relatively new water

Mail Station, CE-43, 1000 CFR part 430, subpart B. heater design not previously covered by

Independence Avenue SW., the test procedures; second, to add a

Washington, DC 20585, (202) 586-9127 , art B of title III of EPCA. as amended. is method of testing to determine the, first

Eugene Margolis. Esq., U.S. Department referred to in thi final rule as the "Act." Part B of hour rating of water heaters equipped

of Energy, Office of General Counsel, title III is codified at 42 U.S.C. szi-ea30. with thermal compensating dip tubes

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EE-RM-94-230 COMMENT 49M

42182 Federal Register I Vol. 55, No. 201 I Wednesday, October 17. 1990 I Rules and Regulations 

DEPARTMENT OF ENERGY 

Office of Conservation and 

Renewable Energy . 

10 CFR Part 430 

[Docket No. CAs-RM-79-105] 

Energy Conservation Program for 

Consumer Products; Final Rule 

Regarding Teat Procedures and 

Energy Conservation Standards for 

Water Heate,. 

AGENCY: Office of Conservation and 

Renewable Energy, Department of 

Energy. . 

ACTION: Final rule. 

SU .... ARY: The Energy Conservation 

Program for Consumer Products is 

conducted under the Energy Policy and 

Conservation Act. as amended. Energy 

consel'Vation standards for most types 

of major household appliances. 

including water heaters. are among the 

required Program elements. The 

legislation also requires the Department 

to establish standard methods of testing 

covered products. In the case of any 

amended test procedure. moreover. the 

Department must determine to what 

extent the amended test procedure 

would alter the measured efficiency of 

the. related energy conservation 

, standard and make appropriate 

corrections to the standard. 

The purposes of the final rule 

announced today are (i) to improve and 

refine the test procedure for water 

heaters and (ii) to amend the energy 

conservation standards for electric 

water heaters in order to reflect the 

changes in measured efficiency caused 

. by the revised test procedure. There is 

n? change to the standard for gas and 

011 water heaters resulting from the 

revised test procedure. 

In addition. today's rule also corrects 

the effective date of standards for 

mobile home furnaces in § 430.32{e) that 

was incorrectly published on February 

7. 1989. 54 FR 6077. The correct effective 

date is September 1. 1990. 

DATES! The effective date for this 

d' cument is April 15. 1991. The effective 

date of standards for mobile home 

furnaces in § 430.32(e) is September 1. 

1990. 

FOR FURTHER INFOR .. AnoN CONTACT: 

Cllrl E. Adams. U.S. Department of 

Energy. Office of Conservation and 

Rene .vable Energy. Forrestal Building. 

Mail Station. CE-43. 1000 

Independence Avenue SW .. ' 

Washington. DC 20585. (202) 586-9127 

Eugene Margolis. Esq., U.S. Department 

of Energy, Office of General Counsel. , ' 

5-051999 0002(00)( 16-ocT -~ 14:02:47) 

Forrestal Building, Mail Station. GC12.1000 Independence Avenue SW .• Washington. DC 20585. (202) 5~507 

'SUPPLE .. ENTARY 'NFORIlAnON: 

I. Background 

A. Program Requirements . 

Part B of title UI of the Energy Policy 

and Conservation Act (EPCA). Public 

Law 94-163. as amended by'the National 

Energy Conservation Policy Act 

(NECPA). Public Law 95-619. the 

National Appliance Endrgy 

Conservation Act (NAECA) of 1987. 

Public Law 100-12. and:he National 

Appliance Energy Conservation' 

Amendments of 1988 (NAECA 1988); 

Public Law 100-357. created the Energy 

Conservation Program for Consumer 

Products other than Automobiles 

(Program).1 The thirteen consumer 

products currently subject to this 

program (often referred to hereafter as 

"covered products") include water 

heaters. the subject of today's 

rulemaking. 

Under the Act. the Program consists 

essentially of three parts: testing. 

labeling. and Federal energy . 

conservation standards. The 

Department of Energy (riOE or 

Department). in consultation with the 

National Institute of Standards and 

Technology (NIST) (formerly National 

Bureau of Standards). is required to 

amend or establish new test procedures 

as appropriate for each of the covered 

producfs. Section 323. The purpose of 

the test procedUres is to produce test 

results which measure the energy 

efficiency, energy use. or estimated 

annual operating cost of a covered 

product during a representative average 

use cycle or period of use and shall not 

be unduly b,'rdensome to conduct. 

Section 323{u)(3)~ A test procedure is not 

required if DOE determines by rule that 

one cannot be developed. Section 

323(d)(I). One hundred and eighty days 

after a test procedure for a product is 

adopted. no manufacturer may represent 

the energy consumption of. or the cost of 

energy consumed by. the product except 

as reflected in tests conducted according 

to the DOE procedure. Section 323(c)(2). 

However. tha one hundred and eighty 

day period referred to in section 

323(c)(2) may be extended for a period 

of up to an additional one hundred and 

eighty days if the Secretary determines 

that the requirements of section 323(c)(2) 

would impose undue burden. Section 

323(c)(3). Test procedures appear at 10 

CFR part 430. subpart B. 

I Part .B of title III of EPCA. a8 amended. is 

referred to in this final rule a8 tbe "Act." Part B of 

title III is codified at 42 U.S.C. 62II1..Q09. 

F4701.FMT ... [16,30) ... 7-Q8-88 

Section 323( e) of the Act requires DOE 

to determine to what extent. if any. a 

proposed test procedUre would alter the 

measured energy efficiency or measured 

energy use of any covered product as 

. determined wider the existing test 

procedure. If DOE determines that an 

amended test procedure would alter the 

measured effiCiency or measured energy 

use of a covered product. DOE is . 

required to amend the related energy 

conservation standard accordingly. In 

determining the amended standard. 

POE is required to measure the energy 

efficiency or energy use of 

representative samples of covered 

products which minimally comply with 

the existing standard. The average 

effiCiency of these representative 

samples. tested using the amended test 

procedure. constitutes the amended 

standard. Section 323(e)(2). 

. B. Test Procedures 

The initial water heater test 

procedures were prescribed by notice 

issued September 27.1977.42 FR 54110 

(October 4.1977). These original 

procedures coupled laboratory tests and 

calculations to obtain estimates of 

energy efficiency for storage type 

electric. gas and oil water heaters. The 

'laboratory tests consisted oi a "cold 

start recovery efficiency test," which 

measured the ability of a water he liter to 

heat cold water. and a "standby 100!Is 

test," which measured the energy loss of 

a water heater when not providing 

heated water. Recovery efficiency and 

percent standby loss are then 

mathematically combined in the 

calculations to obtain an energy factor. 

DOE's overall measure of water heater 

efficiency. Also. the original procedures 

included .calculations for determining 

the annual energy consumption and 

annual operating costs. DOE amended 

the water heater test procedures by . 

notice issued August 30. 1979. in order to 

prescribe a "measure of a water heater's 

useful capacity called first hour rating." . 

where useful capacity was the maximum 

hourly demand which could be met by 

the water heater. 44 FR 52632 

(September 7. 1979). 

By notice published in the Federal 

Register on February 8. 1984. (1984 

proposal). DOE proposed to amend its 

test: 'ocedures for water heaters. 49 FR 

4870. ~'he purpose of the 1984 proposal 

was threefold: First. to extend coverage 

of the test procedures to heat pump 

water heaters. a relatively new water 

heater design not previously covered by 

the test procedures; second. to add a 

method of testing to determine the. first 

hour rating of water heaters equipped 

with thermal compensating dip tubes 
Federal Register / Vol. 55, No. 201 / Wednesday, October 17. 1990 / Rules and Regulations 42163

which provide a more constant outlet (2) Revising the method of test for all test procedure will remain in effect until

water temperature by controlling the water heaters from a no draw test to a the effective date of today's amendment

mixing of incoming cold water with 24-hour simulated use test which for the purpose of rating existing water

stored hot water and third, to make includes a six-hour draw test: and heaters. After the effective date of the

modifications to the test procedures that (3) Revising the first hour rating test amended test procedure, all calculations

would yield more accurate from a calculated estimate to a direct of energy efficiency or energy use of

determinations of energy efficiency and measure for determining a water water heaters or cost of energy

cost of operation for gas, oil and electric heater's ability to supply hot water. consumed by water heaters are to be

storage water heaters. By notice published on January 17, based on the new test procedure.

By notice published March 16, 1984, 1989 (1989 proposal) the Department Consequently, all water heaters must be

DOE. on request of the water heater proposed to amend the energy retested using the test procedure

industry, extended the comment period conservation standards of title 10, part announced today.

42 days and rescheduled the March 15, 430. of the Code of Federal Regulations

1984. public hearing to April 26, 1984. 49 for water heaters to reflect the changes C. Energy Conservation Standards

FR 10071. in measured efficiency which would be NAECA added a definition for water

In commer'j received in 1984 and caused by a newly revised test heaters, as follows:

throughout 1985. numerous parties procedure. 54 FR 1890. The 1989

requested that DOE withdraw the 1984 proposal discussed all the comments whh uties oi. gas. orelectrcity to heat

proposal and wait until a more made on the revision of the test potable water for use outside the heater upon comprehensive proposal could be procedure proposed in the 1987 proposal demand, including- developed. Most notably, on October 2- and included the newly revised test (A) storage type units which heat and store

3,1985. DOE and NIST hosted a forum procedure which incorporated those water at a thermostatically controlled

on testing and rating procedures for comments and which was used to temperature, including gas storage water

consumer products which was attended determine the 1989 proposed heaters with an input of 75,000 Btu per hour

by manufacturers, utilities, States, and conservation standard. Furthermore, the or less, oil storage water heaters with an

public interest groups. At the forum, 1989 proposal stated that the newly input of 105,000 Btu per hour or less, and

there was unanimous agreement that revised test procedure was not included electric storage water heaters with an input

DOE should withdraw the 1984 proposal for comment except in regard to the n ous type units which heat (B) instantaneous type units which heat and initiate the development of a single manufacturers' ability to replicate the water but contain no more than one gallon of

test procedure method which would be DOE methodology in complying with the water per 4,000 Btu per hour of input,

applicable to all types of residential proposed efficiency standards, and including gas instantaneous water heaters

type water heaters, including the indicated that the newly revised test with an input of 200,000 Btu per hour or less.

instantaneous type of water heaters. 'procedure contained in the 1989 oil instantaneous water heaters with an input

By notice published March 13,1987 proposal would be made final when the of 210,000 Btu per hour or less, and electric

(1987 proposal) DOE proposed a single revised standard levels forwater instantaneous water heaters with an input of

test procedure for all types of water heaters were made final. Today's notice 12 kilowatts or less; and

heaters, including instantaneous type finalizes the test procedure included in (C) heat pump type units, with a maximum

water heaters. 52 FR 7972. The 1987 the 1989 proposal as modified by DOE in current rating of 24 amperes at a voltage no

proposal also addressed the matter of the consideration mconsideration 1989 proposal also addressed the of those commentsdesigned comments DOEfrom greater than to transfer 250 volts, which thermal energy are productsone

four test procedure waivers where four dealing with the manufacturers' ability temperature level to a higher temperature manufacturers of water heaters had to replicate the DOE methodology in level for the purpose of heating water.

received allowance to test certain water complying with the proposed standards. including all ancillary equipment such as

heaters under modified test procedures. Today's notice also corrects various fans, storage tanks, pumps, or controls

Since publication of the 1987 proposal, a typographical errors contained in the necessary for the device to perform its

fifth manufacturer has received a test 1989 proposal, several of which were function.

procedure waiver. The 1987 proposal initially identified in a correction notice NAECA also prescribes energy would extend these modifications to all published by DOE in the February 9, conservation standards for 11 types of

manufacturers of similar designs and 1989, Federal Register. 54 FR 6364. appliances including the following

thereby would terminate the five Today's rule amends appendix E of standards for gas, oil-fired, and electric

individual waivers. The five waivers subpart B of 10 CFR part 430. This new water heaters.

are: A.O. Smith Corporation for its gas test procedure is effective 180 days after

water heaters equipped with thermal publication of today's final rule. Section

compensating dip tube, 47 FR 53942 323(c)(2) of the Act specifies that Product class Energy factor

(November 30, 1982). and four effective 180 days after an amended or

manufacturers of water heaters with new test procedure applicable to a 1. Gas water heater........... .62-(.00xRated

large thermal mass designs: Bock Water covered product is prescribed, no galoran).

Heaters Inc., 50 FR 47106 (November 14, manufacturer may make a2. il water heater....... 59-(.otJ9xRated

1985), modified 51 FR 21975 (June 17, representation with respect to energy storage volume in

1986), Ford Products Inc., 50 FR 50678 use or efficiency of such product or the galIons).

(December 11, 1985), modified 51 FR cost of energy consumed by such 3. Ettc watr heater ..... 1 v o95- te

18659 (May 21, 1986), Lochinvar Water product, unless the product is tested in gallons).

Heaters, Inc.. 51 FR 22966 (June 24. 1988), accordance with such amended or new

and Aero Environmental Limited. 53 FR test procedure. Section 323(c)(3) of the

9687 (March 24. 1988). Act allows for an extension of an These standards are effective for

The major issues covered in the 1987 additional 180 days of the aforesaid products manufactured on or after

proposal included: effective date if the Secretary January 1, 1990.

(1) Extending the test procedure to determines upon petition that the Section 323(e) of the Act requires DOE

cover heat pump water heaters and requirements of section 323(2) would to determine to what extent, if any, a

instantaneous type water heaters: impose an undue burden. The extant proposed test procedure would alter the

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Federal Register I Vol. 55, No. 201 I Wednesday, October 17. 1990 I Rules and Regulations 42163 

which provide a more constant outlet 

water temperature by controlling the 

mixing of incoming cold water with 

stored hot water: and third. to make 

modifications to the test procedures that 

would yield more accurate 

determinations of energy efficiency and 

cost of operation for gas. oil and electric 

storage water heaters. 

By notice published March 16. 1984. 

DOE. on request of the water heater 

industry. extended the comment period 

42 days and rpscheduled the March 15. 

1984. public hearing to April 26. 1984. 49 

FR 10071. 

In commer·.:j received in 1984 and 

throughout 1985. numerous parties 

requested that DOE withdraw the 1984 

proposal and wait until a more 

comprehensive proposal could be 

developed~ Most notably. on October 2-

3. 1985. DOE and NIST hosted a forum 

on testing and rating procedures for 

consumer products which was attended 

by manufacturers. utilities. States. and 

public interest groups. At the forum. 

! there was unanimous agreement that 

DOE should withdraw the 1984 proposal 

and initiate the development of a single 

test procedure method which would be 

applicable to all types of residential 

type water heaters. including the 

instantaneous type of water heaters. 

By notice published March 13. 1987 

(1987 proposal) DOE proposed a single 

. test procedure for all types of water 

heaters. including instantaneous type 

water heaters. 52 FR 7972. The 1987 

proposal also addressed the matter of 

four test procedure waivers where four 

manufacturers of water heaters had 

received allowance to test certain water 

hea ters under modified test procedures. 

Since publication of the 1987 proposal. a 

fifth manufacturer has received a test 

procedure waiver. The 1987 proposal 

wLuld extend these modifications to all 

manufacturers of similar designs and 

thereby would terminate the five 

individual waivers. The five waivers 

are: A.D. Smith Corporation for its gas 

water heaters equipped with thermal 

compensating dip tube. 47 FR 53942 

(November 30. 1982). and four 

manufacturers of water heaters with 

large thermal mass designs: Bock Water 

HE'aters Inc .. 50 FR 47106 (November 14. 

1985). modified 51 FR 21975 (June 17. 

1986). Ford Products Inc .. 50 FR 50678 

(December 11. 1985). modified 51 FR 

18659 (May 21. 1986). Lochinvar Water 

Heaters. Inc .. 51 FR 22966 (June 24. 1988). 

and Aero Environmental Limited. 53 FR 

9687 (M~trch 24. 1988). 

The major issues covered in the 1987 

proposal included: 

(1) Extending the test procedure to 

cover heat pump water heaters and 

instantaneous type water heaters: 

5-051999 0003(OO)(16-OCT -90-14:02:51) 

(2) Revising the method of test for all 

water heaters from a no draw test to a 

24-hour simulated use test which 

includes a six-hour draw test: and 

(3) Revising the first hour rating test 

from a calculated estimate to a direct 

measure for determining a water 

heater's ability to supply hot water. 

By notice published on January 17. 

1989 (1989 proposal) the Department 

proposed to amend the energy 

conservation standards of title 10. part 

430. of the Code of Federal Regulations 

for water heaters to reflect the changes 

in measured efficiency which would be 

caused by a newly revised test 

procedure. 54 FR 1890. The 1989 

proposal discussed all the comments 

made on .the revision of the test 

procedure proposed in the 1987 proposal 

and included the newly revised test 

procedure which incorporated those 

comments and which was used to 

determine the 1989 proposed 

conservation standard. Furthermore. the 

1989 proposal stated that the newly 

revised test procedure was not included 

for comment except inregard to the 

manufacturers' ability to replicate the 

DOE methodology in complying with the' 

proposed efficiency standards. and 

indicated that the newly revised test 

'procedure cont~ined in the 1989 

proposal would be made final when the 

revised standard levels for water 

heaters were made final. Today'snotice 

finalizes the test procedure included in 

the 1989 proposal as modified by DOE in 

consideration of those comments 

dealing with the manufacturers' ability 

to replicate the DOE methodology in 

complying with the proposed standards. 

Today's notice also corrects various 

typographical errors contained in the 

1989 proposal. several of which were 

initially identified in a correction notice 

published by DOE in the February 9. 

1989. Federal Register. 54 FR 6364. 

Today's rule amends appendix E of 

subpart B of 10 CFR part 430. This new 

test procedure is effective 180 days after 

publication of today's final rule. Section 

323(c)(2) of the Act specifies that 

effective 180 days after an amended or 

new test procedure applicable to a 

covered product is prescribed. no 

manufacturer may make a 

representation with respect to energy 

use or efficiency of such product or the 

cost of energy consumed by such 

product. unless the product is tested in 

accordance with such amended or new 

test procedure. Section 323(c)(3) of the 

Act allows for an extension of an 

additional 180 days of the aforesaid 

effective date if the Secretary 

determines upon petition that the 

requirements of section 323(2) would 

impose an undue burden. The extant 

F4701.FMT ... [16,30J ... 7-08-88 

test procedure will remain in effect until 

the effective date of today's amendment 

for the purpose of rating existing water 

heaters. After the effective date of the 

amendedtest procedure. all calculations 

of energy efficiency or energy use of 

water heaters or cost of energy 

consumed by water heaters are to be 

based on the new test procedure. 

Consequently. all water heaters must be 

retested using the test proc'edure 

announced today. 

C. Energy Conservation Standards 

NAECA added a definition for water 

heaters. as follows: . 

The term "water heaters" means a product 

which utilizes ,oil. gas. or electricity to heat 

potable water for use outside the heater upon 

demand. including-

(A) storage type units which heat and store 

water at a thermostatically controlled 

temperature. including gas storage water 

heaters with an input of 75.000 Btu ;ler 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: 

. (B) instantaneous type units which heat 

water but 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: and 

(C) heat pump type units. with Ii maximum 

current rating of 24 amperes at a voltage no 

greater than 250 volts. which are products 

designed to transfer thermal energy from one 

temperature level to a higher temperature 

level for the purpose of heating water. 

including all ancillary equipment such as 

fans. storage tanks. pumps. or controls 

necessary for the device to perform its 

function. 

NAECA also prescribes energy 

conservation standards for 11 types of 

appliances including the following 

standards for gas. oil-fired. and electric 

water heaters. 

Product class Energy factor 

1. Gas water heater ......... ..i.62-(.OO19xAated 

, : storage yolume in 

.' I gallon<-'. 2. Oil water heater ............. 1· .S9-(.o..t19xAated 

storage YOluine ,n 

gallons). 

3. Electric water heater ..... ! .9S-(.OOI32xRated " I storage volume in : gallons). 

These standards are effective for 

products manufacturep on or after 

January 1. 1990. 

Section 323(e)of the Act requires DOE 

. to determine to what extent. if any. a 

proposed test procedure would alter the 
42164 Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 199C / Rules and Regulations

measured efficiency or measured energy manufacturer. (Miyazaki, No. 74 at 2). 2 traps and/or piping insulation by the

use of any covered product as Miyazaki maintains that this manufacturer, DOE believes it is determined under the existing test specification will result in different first reasonable to assume that these items procedure. Today's final rule satisfies hour ratings for three identical storage- will be used. Therefore, DOE finds that this requirement with respect to the 1989 type water heaters in which only the the test procedure not be changed to

proposal. Furthermore, section 323(e) specified supply voltage varies. address the issue raised.

requires DOE to test a representative Miyazaki believes that it is absolutely D

sample of covered products that necessary to test all electric wateron of Istantaneous Water

minimally complies with the existing heaters at the same voltage. Heaters

standard using the proposed test Miyazaki is correct in stating that GAMA suggests that-the definition of

procedures today's final rule is based different first hour ratings will result if instantaneous water heaters be revised

on testing a sample of units in identical storage type-water heaters are to include a criterion which limits the

accordance with the 1989 proposal tested with supply voltages which vary outlet temperature to 180 °F or less. acwhich has bee with threvised as discussedal in magnitude. However, the Department (GAMA, No. 78. at 2;

and No. 87, at 3). which has been revised as discussed, believes it is important that water GAA contends that this criterion is a infra. Based on the testing DOE hs heaters should be tested at the common poin of differentiation t 

determined that the standard for electric manufacturers' specified voltage rating. between commercial and residential water heaters shall be changed to: .93 For the vast majority of storage-type water heaters. GAMA further states that -(.00132 X Rated storage volume in water heaters, a fixed voltage is given the 180 F criterion is already included gallons). The standards for gas and oil on therating plate rather thn a in the definitions for gas, electric, and

water heaters shall remain unchanged. specified range. Heat pump water heater oil storage-type water heaters in the test

Section 323(e) of the Act also provides manufacturers typically-specify a procedures. In particular GAMA that models of covered products in use voltage range. These various voltage suggests the following before the date on which the amended ratings are not all the same. It does not

energy conservation standard becomes seem appropriate to require a Gas fueled instantaneous water heater

effective (or revisions of such models commercial test laboratory to select, for means a water heater which utilizes gas as that come into use after such date and example, a 240 volt supply voltage when automatically the energy source controlled manually or by a water flow activated have the same energy efficiency or the rating plate specifies a range of 210 control or a combination of water flow and

energy use characteristics) that comply to 230 volts. Thus DOE concludes that thermostatic control, which is designed to with ener the y conervation standard the test procedure should not be altered deliver water at a controlled temperature of

applicable applicable to to such such covered covered products products on on as suggested by Miyazaki. less than 180 'F. and which has an input greater than 50.000 Btu per hour and less than the day before such date shall be Heat Traps th a

deemed to comply with the amended n 50000 t pe u hour r and less than 200,000 8tu per hour. and a manufacturer's deemed to comply with the amended Public Utility District Number 1 specified storage capacity of less than 2

energy conservation standard. (PUD1) of Snohomish County, gallons. Today's rule. by establishing test Washington State, comments that it D ar i iii

procedures for heat pump water heaters currently operates a rebate programDOE arees wth the above definition

and gas fueled instantaneous water which offers residential customers a $50 f a gas fueled instantaneous water

heaters, also extends the coverage of the rebate if they replace their existing he test procedure standards to these products. Heat pump electric water heater with an energywater heaters must meet the energy efficient one. (PUD1. No. 87, at 1). Copper Tubing

standards for electric water heaters and Qualification for the rebate program is GAA states that the reference to

gas fueled instantaneous water heaters based upon the energy factors published GA s tat eeeee t

must meet the energy standards for gas within The Gas Appliance copper tubing in section 4.3 of the test

water heaters. In the case of as fueled Manufacturers Association (GAMA) procedure should be clarified to specify instantaneous water heaters, the rated "Consumers' Directory of Certified the type used for water lines, i.e.. Type

storage volume may be zero. Efficiency Ratings." The issue in L hard copper tubng as opposed to question relates to the testing of the unit copper tubing used for refrigerant lines.

1. Discussion with heat traps if they are supplied with (GAMA, No. 78. at 2).

the water heater but are not made an DOE concurs with GAMA on this A. Test procedures integral part of the unit. PUD states issue and has changed the statement

DOE is setting forth herein the final that since there is no guarantee that the from "Copper tubing, the same size as

amended test procedures which heat traps will actually be installed, the the connections on the water heater

incorporate changes made to the 1989 energy factor and Energy Guide label shall be connected to the tank and

proposal. Several comments were should not reflect the addition of any extend 24 inches in length" to "Type 'L'

received in regard to correcting accessories, i.e., heat traps. hard copper tubing, the same size as the

typographical errors and relating to a Section 4.3 of the proposed test connectios on the water heater, shall

manufacturer's ability to replicate the procedure states "if heat traps and/or be connected to the tank and extend 24

DOE methodology in complying with the piping insulation are supplied with the inches in length."

new efficiency standa. !s. water heater. then they shall be Location of Storage Tank Temperature installed for testing." The Department Measurement Probes Specification of Electrical Supply agrees that there is no way to guarantee Voltage - that these items will be installed when GAMA recommends that in addition

the water heater is placed into service. to utilizing the anodic device opening or Shu Miyazaki (Myazaki) states the However, if a unit is supplied with heat the re':ef valve opening to insert the current test procedure specifies that the temperature measurement probes within

electrical supply voltage be maintained 2 Comments on the 1984. 1987. and 1989 proposed a storage-type water heater, the use of to within + /- 1 percent of the center of rules were assigned docket numbers and are the hot water outlet opening should also the voltage range specified by the numbered consecutively. be permitted. (GAMA. No. 78. at 2 and

S-051999 000400)( 16-OCT-90- 4:02:54)

F4701.FMT...[16.30 ...7-08-88

EE-RM-94-230 COMMENT 49M

42164 Federal Register / Vol. 55. No. 201 /Wednesday, October 17. 1900 / Rules and Regulations 

measured efficiency or measured energy 

use of any covered product as 

determined under the existing test 

procedure. Today's final rule satisfies 

this requirement with respect to the 1989 

proposal. Furthermore. section 323( e) 

requires DOE to test a representative 

sample of covered products that 

minimally complies with the existing 

standard using the proposed test 

procedures: today's final rule is based' 

on testing a sample of units in 

accordance with the 1989 proposal 

which has been revised as discussed. 

infra. Based on the testing. DOE h~s 

determined that the standard for electric 

water heaters shall be changed to: .93 

-(.00132 X Rated storage volume in 

gallons). The standards for gas and oil 

water heaters shall remain unchanged. 

Section 323(e) of the Act also provides 

that models of covered products in use 

before the date on which the amended 

energy conservation standard becomes 

effective (or revisions of such models 

that come into use after such date and 

have the same energy efficiency or 

energy use characteristics) that comply 

with the energy conservation standard 

applicable to such covered products on 

the day before such date shall be 

deemed to comply with the amended 

energy conservation standard. 

Today's rule. by establishing test 

procedures for heat pump water heaters 

and gas fueled instantaneous water 

heaters. also extends the coverage of the 

standards to these products. Heat pump 

water heaters must meet the energy 

standards for electric water heaters and 

gas fueled instantaneous water heaters 

must meet the energy standards for gas 

water heaters. In the case of gas fueled 

instantaneous water heaters. the rated 

'storage volume may be zero. 

II. Discussion 

A. Test procedures 

DOE is setting forth herein the final 

amended test procedures which 

incorporate changes made to the 1989 

proposal. Several comments were 

received in regard to correcting 

typographical errors and relating to a 

manufacturer's ability to replicate the 

DOE methodology in complying with the 

new efficiency standa. ,!s. 

Specification of Electrical Supply 

Voltage 

Shu Miyazaki (Miyazaki) states the 

current test procedure specifies that the 

electrical supply voltage be maintained 

to within + /- 1 percent of the center of 

the voltage range specified by the 

S-O~I999 0004(00)( 16-OCT -90-14:02:~4) 

manufacturer. (Miyazaki. No. 74 at 2).2 

Miyazaki maintains that this 

specification will result in different first 

hour ratings for three identical storagetype water heaters in which only the 

specified supply voltage varies. 

Miyazaki believes that it is absolutely 

necessary to test all electric water 

heaters at the same voltage. . 

Miyazaki is correct in stating that 

different first hour ratings will result if 

identical storage type-water heaters are 

tested with supply voltages which vary 

in magnitude. However. the Department 

believes it is important that water 

heaters should be tested at the 

manufacturers' speCified voltage rating. 

For the vast majority of storage':type 

water heaters. a fixed voltage is given 

on the rating plate rather than a 

specified range. Heat pump water heater 

manufacturers typically,specify a 

voltage range. These various voltage 

ratings are not all the same. It does not 

seem appropriate to require a 

commercial test laboratory to select. for 

example. a 240 volt supply voltage when 

the rating plate specifies a range of 210 

to 230 volts. Thus DOE concludes that 

the test procedure should not be altered 

as suggested by Miyazaki. . 

Heat Traps 

Public Utility District Number 1 

(PUDl) of Snohomish County. 

Washington State. comments that it 

currently operates a rebate program 

which offers residential customers a $50 

rebate if they replace their existing 

electric water heater with an energyefficient one. (PUDI. No. 87. at 1). 

Qualification for the rebate program is 

based upon the energy factors published 

within The Gas Appliance 

Manufacturers Association (GAMA) 

"Consumers' Directory of Certified 

Efficiency Ratings." The issue in 

question relates to the testing of the unit 

with heat traps if they are supplied with 

the water heater but are not made an 

integral part of the unit. PUDI states 

that since there is no guarantee that the 

heat traps will actually be installed. the 

energy factor and Energy Guide label 

should not reflect the addition of any 

accessories. i.e .• heat traps. 

Section 4.3 of the proposed test 

procedure states "if heat traps and/or 

piping insulation are supplied with the 

water heater. then they shall be 

installed for testing." The Department 

. agrees that there is no way to guarantee 

- that these items will be installed when 

the water heater is placed into service. 

However. if a unit is supplied with heat 

• Comment. on the 1984. 1987. and 1989 proposed 

rules were assilllled docket numbers and are 

numbered consecutively. 

F4701.FMT ... [16.30) ... 7-G8-88 

traps and/or piping insulation by the 

manufacturer. DOE believes it is 

reasonable to assume that these items 

will be used. Therefore. DOE finds that 

the test procedure not be changed to 

address the issue raised. 

Definition of Instantaneous Water 

Heaters 

GAMA suggests that the definition of 

instantaneous water heaters be revised 

to include a criterion which limits the 

outlet temperature to 180 OF or less. 

(GAMA. No. 78. at 2: and No. 87. at 3). 

GAMA contends that this criterion is a 

common point of differentiation 

between com..nercial and residential 

water heaters. GAMA further states that 

the 180 OF criterion is already included 

in the definitions for gas. electric. and 

oil storage-type water heaters in the test 

procedures. In particular GAMA 

suggests the follOWing: 

Gas fueled instantaneous water heater 

means a water heater which utilizes gas as 

the energy source controlled manually or 

automatically by a water flow activated 

control or a combination of water flow and 

thermostatic control. which is designed to 

deliver water at a controlled temperatUre of 

less than 180 OF. and which has an input 

greater than 50.000 Btu per hour and less than 

200.000 Btu per hour. and amanufacturer's 

specified storage capacity of less than 2, 

gallons. 

DOE agrees with the above definition 

of a gas fueled instantaneous water 

heater and has incorporated it within 

the test procedure. 

Copper Tubing 

GAMA states that the reference to 

copper tubing in section 4.3 of the test 

procedure should be clarified to specify 

the type used for water lines. i.e .. Type 

"L" hard copper tubing. as opposed to 

copper tubing used for refrigerant lines. 

(GAMA. No. 78. at 2). 

DOE concurs with GAMA on this 

issue and has changed the statement 

from "Copper tubing. the same size as 

the connections on the water heater 

shall be connected to the tank and 

extend 24 inches in length" to "Type 'L' 

hard copper tubing. the same size as the 

connectior.1I on the water heater. shall 

be connected to the tank and extend 24 

inches in length." 

Location of Storage Tank Temperaturt:: 

Measurement Probes 

GAMArecommends that in addition 

to utilizing the anodic device opening or 

the re"ef valve opening to insert the 

temperature measurement probes within 

a storage-type water heater. the use of 

the hot water outlet opening should also 

be permitted. (GAMA. No. 78. at 2 and 

" 
Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42165

3). Specifically, GAMA recommends is inappropriate. (GAMA, No. 87, at 2). supply to the water heater during the

that section 4.5 of the proposed test GAMA states that for this type of water first-hour rating procedure. Imposing a

procedure be modified as follows: heater the pipes are run horizontally out one hour power or fuel interruption is an

The temperature sensors shall be installed from the tank and subsequently extremely unlikely mode of operation

either through (1) the anodic device opening; downward. GAMA suggests that the for residential water heaters. Secondly,

(2) the relief valve opening; or (3) the hot following statement be added to section the current procedure requires a

water outlet. If installed through the relief 4.3 of the revised test procedure: computation which is an attempt to

valve opening or the hot water outlet, a tee determine how much additional usable

fitting or outlet piping, as applicable, is A water heater 3inches high or less

installed as close as possible to its original (commonly referred to as an under counter or hot water would be generated if 100

location. If the hot water outlet includes a table top model) intended for installation percent of the thermal input to the tank,

heat trap, the heat trap shall be installed on either beneath, adjacent to or in conjunction less standby losses, heats the water

top of the tee fitting. Added fittings shall be with a counter shall have the inlet and outlet contained within the storage tank to a

covered with thermal insulation having an R connections configured as illustrated in usable temperature. This can result in

value of 4 hr ft 'F/Btu. Figure 4. If the water heater is not factory significant error due to the fact that only

DOE agrees with the recommendation equipped with pipe to extend the field Ds w ie the st preocedautrieon connection point of the water lines to outside a portion of the thermal input to the tank and in section 4.5 of testprocedure oe Of the jacket or cabinet. copper tubing shall would produce usable water. The ability

has adopted GAMA's recommended be used to extend the water line horizontally to convert thermal input to usable hot

language to permit the installation of the to the exterior of the jacket or cabinet. water is a function of the water heater

temperature measurement probes DOE concurs with the above design. Several water heater

through the hot water outlet. statement. The test procedure has been manufacturers are currently designing andmanufacturinters heaeturers wiesnc

Prescribed Value of Density of Water changed to incorporate the information and manufacturing water heaters which *into s ctio 4.3. n maximize the conversion of thermal

GAMA notes that the value of the into section 4.3.input into usable hot water. The existing input into hot The existing density of water, 8.214 Ibm/gal for 58 °F, First-Hour Rating test procedure does not give credit to the

is incorrect in section 5.1.1. (GAMA, No. GAMA states that the purpose of the manufacturers of these innovative

Section 5.1.1 has been changed to first-hour rating is to provide a means of products.

remove the incorrect number and to grouping models of similar capability for GAMA's contention that the proposed

require the use of the density of water at the "Ranges of Comparability" test procedure provides a value

the appropriate temperature which will established by the Federal Trade practically the same as the first-hour

vary due to allowable tolerances during Commission (FTC) labelling rules. rating using the existing test procedure

each test. (GAMA, No. 88, at 2 and 3). GAMA is incorrect. For water heaters which

states that in general the revised first- employ two heating elements, the results

Prescribed Value of Specific Heat hour rating will have a uniform effect on of tests conducted by NIST show that

GAMA requests that values for all water heaters. GAMA contends that the first-hour rating using the proposed

specific heat be prescribed throughout the models in the 56 to 64 gallon FTC test procedure yields approximately 95

the test procedure. (GAMA, No. 78, at 3). range of comparability may move to the percent of that obtained using the

The values for specific heat cannot be 65 to 74 gallon range as a result of the existing test procedure. For two of the

prescribed in advance since they are proposed first-hour rating procedure. three water heaters tested at NIST

dependent on the inlet and outlet water GAMA states that the same models will which employed a single heating

temperatures which will vary due to still be grouped together as comparable element, the first-hour rating results

allowable tolerances during each test. models. It further contends that there is were significantly less, up to 30 percent,

Accordingly, this suggestion is rejected. no benefit to revising the first-hour when the proposed test procedure was

rating test, and that the new test will used as compared to the existing test

First Hour Rating Test create an unwarranted need for procedure.

GAMA does not understand why a retesting. The first hour rating within the

draw is in.tiated to activate the heating According to GAMA. test data existing test procedure combines a

element(s) or burner unit prior to the collected by Electrical Testing measured quantity, the number of

first hour rating test if the mean tank Laboratories (ETL) indicates that the gallons removed during a single draw,

temperature is within the specified hour-long first-hour rating test provides with a computed quantity, the ability of

temperature range. (GAMA, No. 78, at a value practically the same as the first- the water heater to produce hot water

3). hour rating determined using the current within a given time interval. The

The purpose of the draw noted by test procedure. GAMA believes that the computed quantity significantly overGAMA was to eliminate the possibility revised first-hour rating test will have a predicts the capability of some water

that the beginning of the first hour rating minimal effect on the measured first- heaters, in particular, electric water

test would coincide with the heating hour rating and the current procedure is heaters with a single element, to

element o- burner unit being activated as appropriate as the proposed first-hour produce water above a prescribed

to recover the tank from standby losses. rating test. temperature level. There are two

DOE believed that this could cause GAMA believes that DOE should reasons for this over-prediction. First,

repeatability problems. However, ret-in the current first-hour rating test the computation procedure assumes that

through continuing testing at NIST, DOE anc. add an optional calculation method the energy supplied during the interval

has discovered that this would not be a to take into account that the proposed between the time at which the

problem and the requirement of the test procedure conditions (mean tank thermostat(s) acts to energize a heating

draw has been eliminated. temperature, flow rate, inlet water element and the end of the hour is

Tet S p fr T e Tp W r H s temperature and ambient temperature) supplied only to the portion of water

Test Setup for Table Top Water Heaters iffer from those in the existing test within the tank, which would oe

GAMA states that the attachment of procedure. removed during a subsequent draw. This

two feet of copper tubing rising DOE notes that the existing procedure is a reasonably good assumption for

vertically from table top water heaters interrupts the electrical power or fuel electric water heaters which employ

S-051999 0005(00) 16-OCT-90-14:02:58)

F4701.FMT...[16.30]...7-08-88

EE-RM-94-230 COMMENT 49M

.' 

Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42165 

3). Specifically. GAMA recommends 

that section 4.5 of the proposed test 

procedure be modified as follows: 

The temperature sensors shall be installed 

either throush (1) the anodic device openins: 

(2) the relief valve openins: or (3) the hot 

water outlet. If installed throuSh the relief 

valve openins or the hot water outlet. a tee 

fittins or outlet pipinS. as applicable. is 

i~stalled as close as possible to its original 

location. If the hot water outlet includes a heat trap, the heat trap shall be installed on 

top of the tee fittinS. Added fittinss shall be 

covered with thermal in<.ulation havins an R 

value of 4 hr ft of !Btu. 

DOE agrees with the recommendation 

and in section4.5 of .... Ie test procedure 

has adopted GAMA's recommended 

language to permit the installation of the 

temperature measurement probes 

through the hot water outlet. 

Prescribed Value of Density of Water 

GAMA notes that the value of the 

density of water. 8.214 Ibm/gal for 58 of, 

is incorrect in section 5.1.1. (GAMA, No. 

78. at 3). 

Section 5.1.1 has been changed to 

remove the incorrect number and to 

require the use of the density of water at 

the appropriate temperature which will 

vary due to allowable tolerances during 

each test. 

Prescribed Value of Specific Heat 

GAMA requests that values for 

specific heat be preScribed throughout 

the test procedur.e. (GAMA. No. 78, at 3). 

The values for specific heat cannot be 

pr!scribed in advance since they are 

dependent on the inlet and outlet water 

temperatures which will vary due to 

allowable tolerances during each test. 

Accordingly, this suggestion is rejected. 

First Hol,ll" Rating Test 

GAMA does not understand why a 

draw is in.liated to activate the heating 

element(s) or burner unit prior to the 

first hour rating test if themean tank 

temperature is within the specified 

temperature range. (GAMA. No. 78. at 

3). 

The purpose of the draw noted by 

GAMA was to eliminate the possibility 

that the beginning of the first hour rating 

test would coincide with tIte heating 

element 0" burner unit being activated 

to recover the tank from standby losses. 

DOE believed tItat this could cause 

repeatability problems. However. 

through continuing testing at NIST. DOE 

has discovered that this would not be a 

problem and the requirement of the 

draw hE:.! been eliminated. 

Test Setup for Table Top Water Heaters 

GAMA states tItat the attachment of 

two feet of copper tubing rising 

vertically from table top water heaters 

S~51999 0005(00)( I (H)CT -90-14:02:58) 

is inappropriate. (GAMA. No. 87. at 2). 

GAMA states that for this type of water 

heater tIte pipes are run horizontally out 

from the tank and subsequently 

downward. GAMA suggests that tIte 

follOWing statement be added to section 

4.3 of the revised test procedure: 

A water heater 36 inches hiilh or less 

(commonly referred to as an under counter or 

table top model) intended for installation 

either beneath. adjacent to or in conjunction 

with a counter shall have the inlet and outlet 

connections configured as illustrated in 

FiSure 4.·If the water heater is not factory 

equipped with pipe to extend the field 

connection point of the water lines to outside 

of the jacket or cabinet. copper tubinS shall 

be used to extend the water line horizontally 

to the exterior of the jacket or cabinet. 

DOE concurs with the above 

statement. The test procedure has been 

changed to incorporate the infonnation 

into section 4.3. 

First-Hour Rating 

GAMA states that the purpose of the 

first-hour rating is to provide a means of 

grouping models of similar capability for 

the "Ranges of Comparability" 

established by the Federal Trade 

Commission (ITC) labelling rules. 

(GAMA. No. 88. at2 and 3). GAMA 

states that in general tIte revised firsthour rating will have a unifonn effect on 

all water heaters. GAMAcontends that 

the models in the 56 to 64 gallon ITC 

range of comparability may move to the 

65 to 74 gallon range as a result of the 

proposed first-hour rating procedure. 

GAMA states that the same models will 

still be grouped together as comparable 

models. It furtIter contends that there is 

no benefit to revising the first-hour 

rating test. and that the new test will 

create an unwarranted need for 

retesting. 

According to GAMA. test data 

collected by Electrical Testing 

Laboratories (ETL) indicates that the 

hour-long first-hour rating test provides 

a value practically the same as the firsthour rating detennined using the current 

test procedure. GAMA believes tItat the 

revised first-hour rating test will have a 

minimal effect on tIte measured firsthour rating and the current procedure is 

as appropriate as the proposed first-hour 

rating test. 

GAMA believes that DOE should 

ret,,:in the current first-hour rating test 

ant. add an optional calculation method 

to take into account that the proposed 

test procedure conditions (mean tank 

temperature. flow rate. inlet water 

temperature and ambient temperature) 

differ from those in the existing test 

procedure. 

DOE notes that the existing procedure 

interrupts the electrical power or fuel 

F4701.FMT ... [16;30) ... 7 -06-88 

supply to tIte water heater during the 

first-hour rating procedure; Imposing a 

one hour power or fuel interruption is an 

extremely unlikely mode of operation 

for residential water heaters. Secondly. 

the current procedure requires a 

computation which is an attempt to 

detennine how much additional usable 

hot water would be generated if 100 

percent of the thennal input to the tank. 

less standby losses. heats the watf:r 

contained within the storage tank to a 

usable temperature. This can result in 

significant error due to the fact that only 

a portion of the thennal input to the tank 

would produce usable water. The ability 

to convert thennal input to usable hot 

water is a function of tIte water ileater 

design. Several water heater 

, manufacturers are currently designing 

and manufacturing water heaters which 

maximize the conversion of thermal 

input into usable hot water. The existing 

test procedure does not give credit to tile 

manufacturers of these innovative 

products. 

GAMA's contention that the proposed 

test procedure provides a value 

practically the same as the first-hour 

rating using the existing test procedure 

is incorrect. For water heaters which 

employ two heating elements. the results 

of tests conducted by NIST show that 

the first-hour rating using the proposed 

test procedure yields approximately 95 

percent of that obtained using the 

existing test procedure. For two of the 

three water heaters tested at NIST 

which employed a single heating 

element. the first-hour rating results 

were significantly less. up to 30 percent, 

when the proposed test procedure was 

used as compared to the existing test 

procedure. . 

The first hour rating within the 

existing test procedure combines a 

measured quantity. the number of 

gallons removed during a single draw. 

with a computed quantity. the ability of 

the water heater to produce hot water 

witItin a given time interval. The 

computed quantity significantly overpredicts the capability of some water 

heaters. in particular. electric water 

heaters with a single element. to 

produce water above a prescribed 

temperature level. There are two 

reasons for this over-prediction. First. 

the computation procedure assumes that 

the energy supplied during the interval 

between t~je time at which the 

thennostat(s) acts to energize a heating 

element and the end of the hour is 

supplied only to the portion of water 

within the tank. which would ole 

removed during a subsequent draw. This 

is a reasonably good assumption for 

electric water heaters which employ 

I 

\ 
42166 Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

dual elements, since the upper element GAMA is incorrect in stating that the using today's test procedure. The water

is used to first heat the water in the reason the revised test procedure gives heater was tested using several different

upper portion of the water heater. a different measure of standby loss, in "off-peak" schedules as well as a test in

However, for tanks which employ a comparison to the existing test the normal fully-on mode. The result of

single element, the water heater may not procedure, is due to the decreased test these tests was that the energy factor

be able to elevate the temperature duration. A different standby loss essentially stayed constant regardless of

above the required minimum outlet measurement is obtained because the whether the tank was tested "off-peak"

temperature. Additionally, the inlet and outlet piping arrangement has or not. NIST thus concluded that there is

calculation procedure does not take into been changed. In the proposed test no need for a test procedure which

account the mixing which occurs procedure, two feet of vertical differs from today's test procedure to

between the cold entering water and the uninsulated copper piping are connected determine the energy factor of off-peak

water within the storage tank during the to both the inlet and outlet ports of the water heaters.

removal of hot water. water heater. The existing test DOE recognizes that where off-peak The first hour rating is gaining procedure utilizes insulated galvanized electric rates are offered by utilities, recognition as a sizing criterion for piping configured in such a manner as to customers may obtain economic benefits

selocng water heaters. Because of this, form an external heat trap. In fact, by using "off-peak" water heaters.

the Department believes that it is GAMA clearly points out this difference However, based on the efficiency tests

beneficial to improve the accuracy of and its impact on standby losses in its conducted by NIST, DOE has

the test, as discussed above, especially comments addressing the proposed determined that today's test procedure

the relative rankings to recognize water amended energy conservation standards is adequate to measure the energy factor

heater designs which improve the first for electric water heaters. Accordingly, of "off-peak" water heaters

hour rating. This would allow the GAMA's recommendation is not

selection of a "smaller" water heater adopted. B. Standards

which could meet the consumers needs whiand save enery by haing smersne Section 6.1.4 DOE is herein amending the energy and save energy by having smaller efficiency standards for water heaters to

standby losses. Therefore, DOE is GAMA states that it would simplify refflet he canerds forwnsitated br the

retaining the proposed first hour rating matters if an equation within section reflsed the ch es ee ae

with one minor adjustment. 6.1.4 were formulated in such a manner evised test procedures. Several

Through continuing testing at NIST, so that a number which is usually comments were received regarding the

DOE discovered that under certain negative would not be subtracted from proposed revision to the standards and

conditions the proposed first hour rating another number. (GAMA, No. 87, at 4). they are iscussed below:

test could be non-repeatable because of GAMA is correct in noting that the Rated Volume

thermostat variability. To preclude any form of the equation will usually result

unacceptable repeatability problems, in a negative number being subtracted The Calforna Energy Commssion

DOE is today publishing a slightly from another number. However, DOE (CEC] states that it presumes the

revised first hour rating test procedure believes that the form of the equation is allowable energy factor is computed by

from that previously proposed. As more conceptually correct than that ubtracting from a constant the product

published, if a draw is underway at the proposed by GAMA in that a higher f a econd constant times the measured

end of the hour, that draw is completed. ending tank temperature represents a voume. (CECNo. 82 at 1 and 2).

However, if a draw is not underway, positive energy input which is then However, within the proposed rule, the

instead of drawing the tank down to subtracted. Additionally, DOE does not term "rated storage volume" is used in

T,,i, at that time, the test is continued believe that the current equation is the computation of the Federal energy

until the tank recovers and then a final difficult to use and does not agree with conservation standards for water

draw is performed. In both cases the changing the equations within section heaters. CEC furtherstatesthat since

water drawn over the total duration of 6.1.4. the meaning of the term "rated volume

the test is prorated to one hour. Of-Pa WaerHas commonly used in the industry is the test Water i rOff-Peak Heaters quite different from DOE's intent in the

Computation of Standby Losses The number of comments received by proposed rule, the word "rated" should

GAMA comments that the revised test DOE concerning "off-peak" water be dropped from the rule. It also notes

procedure gives a significantly different heaters exceeded that on any other that footnote number one in the

measure of standby loss because of the subject. American Electric Power, proposed standard referring to the

shortened standby period. (GAMA, No. Appalachian Power Company, definition of "rated storage volume" is

87. at 3 and 4). GAMA states that Columbus Southern Power, Indiana referenced only to gas water heaters.

although the standby loss measurement Michigan Power Company. Kentucky not to oil or electric water heaters.

in the revised test procedure is adequate Power Company, Ohio Power Company, In a related matter, GAMA suggests

for the way in which it is utilized, it and Wheeling Power Company comment that DOE adopt the following language

should not be used for other purposes they are pleased that DOE intends to as the definition foi "rated storage

outside the framework of the test explore various concepts for testing volume": "The water storage capacity of

procedure, since it is an abbreviated. these units. These utilities state that a water heater as specified by the

less precise method in relation :o the 48- "off-peak" water heating is an important manufacturer." This definition would be

hour standby loss test method within the element in both their Energy substituted for the reference to the tank

current test procedure. GAMA contends Management and Load Management capacity measurements set forth in the

that the inclusion of a specific Programs. They also state that the current DOE water heater efficiency test

calculation for standby loss in the current test procedure does not procedures. (GAMA. No. 78. at 1).

revised test procedure is an implicit accurately show the energy At the time ~f the proposed rule, there

invitation to use this standby loss value conservation benefits provided by "off- was not a definition of "rated storage

for other purposes for which it is not peak" water heaters. volume." It was DOE's intention to

suited. GAMA concludes that this term DOE contracted with NIST to test an define "rated storage volume" as the

should be deleted. electric "off-peak" type water heater measured volume for use in the

S-5 1999 0006(OOX16-OCT-90-14403.01)

F4701.FMT...[16,301...7-08-88

EE-RM-94-230 COMMENT 49M

42168 Federal Registe~ / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 

dual elements; since the upper element 

is used to first heat the water in the 

upper portion of the water heater. 

However. for tanks which employ a 

single element. the water heater may not 

be ,able to elevate the temperature 

above the required minimum outlet 

temperature. Additionally, the 

calculatio~ procedure does not take into 

account the mixing which occurs ' 

between the cold entering water and the 

water within the storage tank during the 

remo,':ll of hot water. 

The first hour rating is gaining 

recognition as a sizing criterion for 

selp,L..ng water heaters. Because of this. 

the Department believes that it is 

beneficial to improve the accuracy of 

the test. as discussed above. especially 

the relative rankings to recognize water 

heater designs which improve the first 

hour rating. This would allow the 

selection of a "smaller" water heater 

which could meet the consumers needs 

and save energy by having smaller 

standby losses. Therefore. DOE is 

retaining the proposed first hour rating 

with one minor adjustment. 

Through continuing ,testing at NIST. 

DOE discovered that under certain 

conditions the proposed first hour rating 

test could be non-repeatable because of 

thermostat variability. To preclude any 

unacceptable repeatability problems. 

DOE is today publishing a slightly 

, revised first hour rating test procedure 

from that previously proposed. As 

published. if a draw is underway at the 

end of the hour. that draw is completed. 

However. if a draw is not underway. 

instead of drawing the tank down to 

T ~ at that time. the test is continued 

until the tank recovers and then it final 

draw is performed. In both,cases the 

water drawn over the total duration of 

the test is prorated to one hour. 

Computation of Standby Losses 

GAMA comments that the revised test 

procedure gives a significantly different 

measure of standby loss because of the 

shortened standby period. (GAMA. No. 

87. at 3 and 4). GAMA states that 

although the standby loss measurement 

in the revise'd test procedure is adequate 

for the way in which it is utilized; it 

should not be used for other purposes 

outside the framework of the test 

procedure. since it is an abbreviated. 

less precise method in relation :~ t~e 48-

hour standby loss test method within the 

current test procedure. GAMA contends 

that the inclusion of a specific 

calculation for standby loss in the 

revised test procedure is an implicit 

invitation to use this standby loss value 

for other purposes for which it is not 

suited. GAMA concludes that this term 

should be deleted. 

S-051999 0006(00)( 16-OCT -90-14:03:01) 

GAMA is incorrect in stating that'the' 

reason the revised test procedure gives 

a different measure of standby 108s., in 

comparison to the existing test 

procedure. is due,to the decreased fest 

duration. A different standby loss 

measurement is obtained because thl! 

inlet and outlet piping arrangement has 

been changed. In the proposed test 

procedure. two feet of vertical 

uninsulated copper piping are connected 

to both the inlet and outlet ports of the 

water heater. The existing test 

procedure utilizes insulated galvanized 

piping configured in such a manner as to 

form an external heat trap. In fact. 

GAMA clearly poults out this difference 

and its impact on standby losses in its 

comments addreSSing the proposed 

amended energy conservation standards 

for electric water heaters. Accordingly. 

GAMA's recommendation is not ' 

'adopted. 

. Section 6.1.4 

GAMA states that it would simplify 

matters if an equation within section, , 6.1.4 were formulated in such a manner 

so that a number which is usually 

negative would not be subtracted from 

another number. (GAMA. No. 87. at 4). 

GAMA is correct in noting that the 

form of the equation will usually result 

in a negative number being subtracted 

from another number. However. DOE 

believes thatthe form of the equation is 

more conceptually correct than that 

proposed by GAMA in that a higher 

ending tank temperature represents a 

positive energy input which is then 

subtracted. Additionally. DOE does not , believe that the current equation is 

difficult to use and does not agree with 

changing the equations within section 

6.1.4. 

,Off-Peak Water Heaters, 

The number of comments received by 

DOE concerning "off-peak" water, 

heaters exceeded that on any other 

subject. American Electric Power. 

Appalachian Power Company. 

Columbus Southern Power. Indiana 

Michigan Power Company. Kentucky 

Power Company. Ohio Power Company. 

and Wheeling Power Company comment 

they are pleased that DOE intends to 

explore various concepts for testing 

these units. These utilities state that "off~peak" water heat~ng is an important 

element in both their Energy 

Management and Load Management 

Programs. They also state that the 

current test procedure does not 

accurately show the energy , conservation benefits provided by "offpeak" water heaters. 

DOE contracted with NIST to test an 

electric "off-peak" type water heater' 

F4701.FMT ... [16.30) ... 7-06-88 

using today's test procedure. The water 

heater was tested using several different 

"off-peak" schedules as well as a,test in 

the normal fully-on mode. The result of 

these tests was that the energy factor 

essentially stayed constant regardless of 

whetherthe t/(lnkwas tested "off-peak" 

or not. NIST thus concluded that there is 

no need for a test procedure which 

differs from today's test procedure to 

determine the energy factor of off-peak 

water heaters. 

DOE recognizes that where off-peak 

electric rates are offered by utilities. , customers may obtain economic benefits 

'by using "off-peak" water heaters. 

However. based on thE efficiency tests 

conducted by NIST. DOE has 

determined that today's test procedure 

is adequate to measure the energy factor 

of "off-peak" water heaters. 

B. StandaiYis 

DOE is herein amending the energy 

effiCiency standards for!water heaters to 

reflect the changes necessitated by the 

revised test procedures. Several 

comments were received regarding the 

proposed revision to the standards and 

they are discussed below: 

Rated Volunie 

The California Energy Commission 

(CEC) states that it presumes the 

allowable energy factor is computed by 

subtracting from a constant the product 

of a second constant times the measured 

volume. (CEC. No. 82 ~t 1 and 2). 

However, within 'the proposed rule. the 

term "rated storage volume" is used in 

the computation of the Federal energy 

conservation standards for water 

heaters. CEC further states that since 

the meaning of the term "rated volume" 

as commonly used in the industry is 

quite different from DOE's intent in the ' 

proposed rule. the word "rated" should 

be dropped from the rule. It also notes 

that footnote number one in the 

proposed standard referring to the 

definition of "rated storage volume" is 

referenced only to gas water heaters. 

not to oil or electric water heaters. 

In a related matter. GAMA suggests 

that DOE adopt the following language 

as the definition fa! "rated storage 

volume": "The water storage capacity of 

a water heater as specified by the 

manufacturer." This definition would be 

substituted for the reference to the tank 

capacity measurements set forth in the 

current DOEwater heater effiCiency test 

procedures. (GAMA. No. 78. at 1). 

At the time ~f the proposed rule. there 

was not a definition of "rated storage 

volume." It was DOE's intention to 

define "rated storage volume"as the , measured volume for use in the 
Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42167

standard. However, upon further Depending upon the results of those justify lowering the statutorily- consideration, and for purposes of the tests, as well as experience under the established minimum efficiency instant rule, DOE accepts the arguments rule adopted today, DOE may consider standard for electric water heaters. set forth in the comments regarding revising the definition of "rated storage AGA urges DOE to conduct additional industry usage and has defined "rated volume" in connection with the next independent testing of water heaters to storage volume" to mean the water water heater standards review. verify the differences in test methods storage capacity of a water heater, in Inclusion of Heat Pump Water Heaters before DOE amends the statutory gallons, as specified by the minimum efficiency level. AGA states

Additionally, 

manufacturer. i.e., the "rated volume". GAMA states that residential heat that the number of units tested at NIST the footnote in the pump water heaters are included as a represents less than 1 percent of the standard has been modified to indicate covered product in NAECA and that 1.000 basic models of electric water that this definition applies to all types of they are subject to minimum efficiency heaters available. AGA further states water heaters. requirements. (GAMA, No. 78, at 1). that testing should be perfc.med on 20- However, the Department has some DOE agrees and notes that by and 100-gallon models and on models concern about this use of "rated storage establishing test procedures for heat with high efficiency factors. volume" in the standard because the pump water heaters, today's rule In closing. AGA states that it does not measure of this quantity seems to be extends standards coverage to these believe DOE has put forward sufficient relatively uncontrolled and by proucts. DOE also notes that since heatjustification to lower the statutory specifying a large "rated volume" a pump water heaters use electric power, minimum standard for electric water manufacturer can lower the standard they are covered under the requirements heaters. AGA asserts that the DOE level that a water heater must meet. In for electric water heaters. DOE willhasta the oral testimony at the January 1989 consider separate standards for heat proposal fas taken the expedient public hearings, DOE staff pointed out pump water heateers on the next review apracho minim ted efiienstatutory that all the water heaters tested by NIST cycle for water heater standards in 1992. rather than requiring electric ater in support of this rule had measured Amended Energy Efficiency Standards heaters to comply with the statute. volumes smaller than the "rated GAMA states that it agrees with theand AGA DOE volume." GAMA staff replied that this G A M A s tates th at i t agrees w i th the In "esponse to GAMA and AGA, DOE difference. asA dutaff reie tat tis proposal to retain unchanged the notes that NAECA requires that difference was due to manufacturing -conservation standards for gas and oil efficiency standards shall be revised tolerance. While DOE does not have water heaters. (GAMA. No. 88). Testing whenever the test procedures are enough data to be statistically conducted at ETL for GAMA, yielded revised so that units that minimally met significant, it questions whether the results which were consistent with the standards under the old test difference in rated and measured DOE's data and the conclusion reflected procedure will meet the revised volume is due solely to manufacturing in DOE's proposal for gas and oil water standard under the new test procedure; tolerance. If that were the case, one heaters. However, GAMA does not In other words, a unit that met the would expect some measured volumes agree with the proposed amended standards under a test procedure is not to be above the "rated volume" and energy conservation standards for allowed to fail to meet the standard just some to be below. All 13 water heaters electric water heaters. GAMA proposes because the test procedure has changed. tested had measured volumes lower that the minimum efficiency standard DOE agrees that the units tested are not than the "rated volume". Further, oral for residential electric water heaters be representative of the complete universe testimony by GAMA at the January, lowered by 0.04 rather than 0.02. GAMA of water heaters. However, under 1989 public hearings indicated that "the states that while the average difference NAECA the models tested need not be vast majority are below the rated of all the test results from ETL is less representative of the entire product number." However. at the same time, than 0.04. the differences are greater for universe: rather they should be DOE is not aware of any evidence or the small volume models. GAMA further representative of those models which data which suggests that abuse or states that since these small volume marginally comply with the standard. consumer detriment has resulted from models represent the majority of electric Because the effecrof the test procedure use of the definition advocated by the water heater shipments, the adjustment on the majority of models which exceed industry: and, the definition DOE is should be weighted to acknowledge this. the standards is not relevant to the pass- adopting for this rule has previously The models selected for the ETL tests. fail issue, the pertinent question thus is: been adopted by the Z-21 Subcommittee according to GAMA, represent less what is the effect of the new test on Standards for Gas Water Heaters. popular models or models with special procedure on those models that only Additionally, at the public hearings, design features, such as models factory minimally meet the standard? The six DOE staff asked GAMA if there were equipped with heat traps, low-boy and electric units tested by NIST for DOE limits as to how high the "rated volume" table top models. meet this criterion, could be relative to the measured On the other hand, the American Gas As stated above. GAMA submitted volume. It was stated that this Association (AGA) challenges DOE's test results of several water heaters difference was limited by adherence to proposal to lower the energy efficiency tested by ETL using both the old and the testing agency's specifications for standard for electric water heaters. revised test procedures to support its safety. However, DOE notes that one of (AGA, No. 84). It believes that DOE claim that the constant in the equation the six electric water heaters and one of selected an inadequate sample of for the electric water heater standard

NIST 

the five gas water heaters iested by electric water heaters to test under the should be lowered by 0.04. However, the in support of today's-rule amended test procedure and that the units submitted by GAMA were not exceeded this limit. Thus, again some models selected by DOE are not truly those marginally at the standard. uncertainty exists with regard to which re"resentative of the universe of electric Therefore, most of these test results are criterion to use. water heaters available. According to not applicable to the question at hand. As a consequence, DOE will continue AGA. given these shortcomings in the DOE recognizes that the number of to test water heaters and collect data on amended test procedure's methodology, marginal units tested is limited but rated versus measured volume. AGA does not believe that DOE can believes that they fairly represent

S-051999 .0007(00Xo16-OCT-90-14:03 05

F4701.FMT-..-l.R-.nl 7-n.t.R

EE-RM-94-230 COMMENT 49M

·' 

: . ~ . '. , .. :: .,~.' 

Federal Register I Vol. 55. No. 201 I Wednesday, October 17. 1990 I Rules and Regulations 42167 

standard. However. upon further 

consideration. and for purposes of the 

instant rule. DOE accepts the arguments 

set forth in the comments regarding 

industry usage and has defmed "rated 

storage volume" to mean the water 

storage capacity of a water heater. in 

gallons. as specified by the 

manufacturer. i.e .. the "rated volume". 

Additionally. the footnote in the 

standard has been modified to indicate 

that this definition applies to all types of 

water heaters. 

However. the Department has some 

concern about this use of "rated storage 

volume" in the standard because the 

measure of this quantity seems to be 

relatively uncontrolled and by 

specifying a large "rated volume" a 

manufacturer can lower the standard 

level that a water heater must meet. In 

oral testimony at the January1989 

public hearings. DOE staff pointed out 

that all the water heaters tested by NIST 

in support of this rule had measured 

volumes smaller than the "rated 

volume.:' GAMA staff replied that this 

difference was due to manufacturing 

tolerance. While DOE does not have 

enough data to be statistically 

significant. it questions whether the 

difference in rated and measured 

volume is due solely to manufacturing 

tolerance. If that were the case. one 

would expect some measured volumes 

to be above the "rated volume" and 

some to be below. All 13 water heaters 

tested had measured volumes lower 

than the "rated volume". Further. oral 

testimony by GA¥A at the January. 

1989 public hearings indicated that "the 

vast majority are below the rated 

number." However. at the same time. 

DOE is not aware of any evidence or 

data which suggests that abuse or 

consumer detriment has resulted from 

use of the definition advocated by the 

industry: and. the definition DOE is 

adopting for this rule has previously 

been adopted by the Z-2l Subcommittee 

on Standards for Gas Water Heaters. 

Additionally. at the public hearings. 

DOE staff asked GAMA if there were 

limits as to how' high the "rated volume" 

could be relative to the measured 

volume. It was stated that this 

difference was limited by adherence to 

the testing agency's specifications for 

safety. However. DOE notes that one of 

the six electric water heaters and one of 

the five gas water heaters iested by 

NIST in support of today's'rule 

exceeried this limit. Thus. again some 

uncertainty exists with regard to which 

criterion to use. 

As a consequence. DOE will continue 

to test water heaters and collect data on 

rated versus measured volume. 

S~51999 . 00}7(OO)(I(K)CT-90-14:03:05) 

Depending upon the results of those 

tests. as well as experience under the 

rule adopted today. DOE may consider 

revising the definition of "rated storage 

volume" in connection with the next 

water heater standards review. 

Iriclusion of Heat Pump Water Heaters 

GAMA states that residential heat 

pump water heaters are included as a 

covero!d product in NAECA and that 

they are subject to minimum efficiency 

requirements. (GAMA. No. 78. at 1). 

DOE agrees and notes that by 

establishing test procedures for heat 

pump water beaters. today's rule 

extends standards coverage to these 

proJucts. DOE also notes that since heat 

pump water heaters use electric power, 

they are covered under the requirements 

for electric water heaters. DOE will 

consider separate standards for heat 

pump water heaters on the next review 

cycle for Vlater heater standards in 1992. 

Amended Energy Efficiency Standards 

GAMA states thai it agrees with the 

proposal to retain unchanged the . conservation standards for gas and oil 

water heaters. (GAMA. No. 88). Testing. 

conducted at ETL for GAMA. yielded 

results which were consistent with 

DOE's data and the conclusion reflected 

in DOE's proposal for gas and oil water 

heaters. However, GAMA does not 

agree with the proposed amended 

energy conservation standards for 

electric water heaters~ GAMA proposes 

that the minimum efficiency standard 

for residential electric water heaters be 

lowered by 0.04 rather than 0.02. GAMA 

states that while the average difference 

of all the test results from ETL is less 

than 0.04. the differences are greater for 

,the small volume models. GAMA further 

states that since these small volume 

models represent the majority of electric 

water heater shipments. the adjustment 

should be weighted to acknowledge this. 

The models selected for the ETL tests. 

according to GAMA. represent less 

popular models or models with special 

design features. such as models factory 

equipped with heat traps. low-boy and 

table, top models. 

On the other hand. the American Gas 

Associ.dion (AGA) challenges DOE's 

proposal to lower the energy efficiency 

standard for electric water heaters. 

(AGA. No. 84). It beliEves that DOE 

selected an inadequate sample of 

electric water heaters to test under the 

amended test procedure and that the 

monels selected by DOE are not truly 

re"'resentative of the universe of electric 

wdter heaters available. According .to 

AGA. given these shortcomings in the 

amended test procedure's methodology. 

AGA does not believe that DOE can 

justify lowering the statutorilyestablished minimum efficiency 

standard for electric water heaters. 

AGA urges DOE to conduct additional 

independent testing of water heaters to 

verify the differences in test methods 

before DOE amends the statutory 

minimum efficiency level. AGA states 

'that the number of units tested at NIST 

represents less than 1 percent of the 

1.000 basic models of electric water 

heaters available. AGA further states 

that testing should be perf('.med on 20-

and lOO-gallon models and on models 

with high efficiency factors. 

In closing, AGA states that it does not 

believe DOE has put forward sufficient 

justification to lower the statutory 

minimum standard for electric water 

heaters. AGA asserts that the DOE 

proposal has taken the expedient 

approach of lowering the statutory 

mandated minimum efficiency level 

rather than requiring electric water 

heaters to comply with the statute. 

In response to GAMA and AGA. DOE 

notes that NAECA requires that 

efficiency standards shall be revised 

whenever the test procedures are 

revised so that units that minimally met 

the standards under the old test 

procedure will meet the revised 

standard under the new test procedure; 

In other words. a unit that met the 

standards under a test procedure is not 

allowed to fail to meet the standard just 

because the test procedure has changed. 

DOE agrees that the units tested are not 

representative of the complete universe 

of water heaters. However. under 

NAECA the models tested need not be 

representative of the entire product 

universe; rather they should be 

representative of those models which 

marginally comply with the standard. 

Because the effe(.t-of the test procedure 

on the majority of models which exceed 

the standards is not relevant to the passfail issue, the pertinent question thus is: 

what is the effect of the new test 

procedure on those models that only 

minimally meet the standard? The six 

electric units tested by NIST for DOE 

meet this criterion. 

As stated above. GAMA submitted 

test results of several water heaters 

tested by ETL using both the old and 

revised test procedures to support its 

claim that the constant in the equation 

for the electric water heater standard 

should be lowered by 0.04. However. the 

units submitted by GAMA were not 

those marginally at the standard. 

Therefore. most of these test results are 

not applicable to the question at hand. 

DOE recognizes that the number of 

marginal units tested is limited but 

believes that they fairly represent 
42168 Federal Regiser / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

marginal units and that using the accordingly to achieve no net change in economic impact on a substantial

average of these results is appropriate. energy usage, today's rule will not affect number of small entities." DOE certified

The results of these tests were reported the quality or distribution of energy in the notice of proposed rulemaking, in the 1989 Proposal as Tables 1, 2, and usage, and will not result in any and does so again, that the rule, which

3. Therefore, DOE has elected to modify environmental impacts. DOE, therefore, affects manufacturers of water heaters,

the standard as proposed in the 1989 has determined that amending the test will not have significant economic

Proposal by lowering the first term of procedures and adjusting the energy impact, but rather simply improves the the energy factor equation for electric efficiency standards accordingly under test procedures and adjusts the related

water heaters by 0.02, which is the the Program do not individually or energy efficiency standards accordingly.

average reduction of the electric units cumulatively have a significant effect on Therefore, DOE certifies that the final

tested, and by leaving the standard for the human environment. Consequently, rule, as promulgated, will not have a

oil and gas water heaters unchanged. neither an Environmental Impact "significant economic impact on a

In selecting this standard based on Statement nor an Environmental substantial number of small entities."

average test results, it is recognized that Assessment is required for today's rule. D. Federalism Review

some particular marginal water heaters B. Review Under Executive Order 12291

might not meet the new standard. Executive Order 12612, 52 FR 41685

It should be noted that any basic The final rule has been reviewed in (October 30, 1987), requires that

model that was manufactured before the accordance with Executive Order 12291, regulations or rules be reviewed for any effective date of today's final rule, 46 FR 13193 (February 19, 1981), which substantial direct effects on States, on

regardless of when the individual unit directs that all regulations achieve their the relationship between the national

was in fact manufactured, and which intended goals without imposing government and the States, or on the

was certified as meeting the standard unnecessary burdens on the economy, distribution of power and

using the old test procedure, is on individuals, on public or private responsibilities among various levels of

grandfathered under NAECA as organizations or on State and local government. If there are sufficient

complying with today's standard. governments. Executive Order 12291 substantial direct effects, then Executive

DOE is also concerned over the test also requires that regulatory impact Order 12612 requires preparation of a

results obtained by NIST and those analyses be prepared for "major rules," Federalism assessment to be used in all

submitted by GAMA in that for the great which it defines as any regulation that is decisions involved in promulgating and

majority of units tested, the measured likely to result in: (1 An annual effect implementing a regulatioor a rule.

values for energy factor were less than on the economy of $100 million or more; By operationf the statute, standards

that reported in the GAMA directory. If (2) a major increa in c or prices for under the Program initially preempt this situation was brought to DOE's sumers, dual ndustri inconsistent State regulations. Thus in

attention by one party complaining Federal, State, loy thor these standardscould be said to

against another, DOE believes that in an agencies or geographic regions; or 3) thave a substantial direct effect on State

enforcement proceeding the basic model it rs e ts governents. Today ater heate could be found in noncompliance competition, employment, investment, vernments. Today's water heter productivitycould be found in noncnnovation, or on the standards provisions, however, have the

mII. Correction of Effective Date for ability of the United States-basedpractical effect of maintaining the status

Mobile Home Furnaces Efficiency enterprises to compete with foreign- quo of the statutory standards levels.

Standards based enterprises in domestic or export Thus the revised standards provisions enterprises , T~iwill have no added substantive or

In reviewing the final rule regarding markets.

certification and enforcement of The final rule amends already existing ne8ative effect on States. Basd on the

regulations related to energy test procedures for water heaters and foregoing, DOE has concluded that

conservation standardfor consumer efficiresncy correstpondingly standards.Afccordingly, adjusts the energy DOE for th preparation of a Federalism assessment

products published February 7, 1989, in efficiency standards. Accordingly, DOE for this rulemaking was not warranted.

the Federal Register (54 FR 6077), DOE has determined that any burden ist of Subjects in 10 CF Part 430

mobile home furnaces efficiency government entity by the amendment of Administrative practice and

noted that the effective date listed for govered on enty bysd = te amndut, or Administrative practice and

mobile home furnaces efficiencys osisrft, standards, January , 1990, was extant procedures is not significant procedure. Energy conservation.

incorrect. Thecorrect date is September -enough to bring the final rule within the Household appliances.

1, 1990. n e Tods m s tt definition of "major rule." In consideration of the foregoing, the

correction. In accordance with section 3(c)(3) of Department of Energy amends part 430

Executive Order 12291, which applies to of chapter II of title 10, Code of Federal

IV. Other Reviews rules other than major rules, the final Regulations, as set forth below.

A. Environmental Review rule was submitted-to the Office of Issued in Washington, DC. October 1, 1990.

Management and Budget (OMB) for .I. M richael Davis. Pursuant to section 7(c}(2) of the review without a regulatory impact * Federal Energy Administration Act of analysis.ecretry Conservation and

1974 (FEAA) (15 U.S.C. 761-790). a copyRenewbleEner

of this notice has been submitted to the C. Regulatory Flexibility Act PART 430-ENERGY CONSERVATION

Administrator of the Environmental The Regulatory Flexibility Act, 5 PROGRAM FOR CONSUMER

Protection Agency for comments U.S.C. 601-812. requires that an agency PRODUCTS

concerning the impact,of this proposal prepare an initial regulatory flexibility 1. The authority citation for part 430

on the quality of the environment. analysis tobe published at the time the continues to read as follows:

Since the amended test prr -edures proposed rule is published. This Authority: Energy Policy and Conservation

under the Program will be used only to requirement (which appears in section Act. title IlI. part B. as amended by National

standardize the measurement of energy 603) does not apply if the agency Energy Conservation Policy Act. title IV, part

usage and the energy efficiency certifies that the rule will not. if 2. National Appliance Energy Conservation

standards have been adjusted promulgated, have a significant Act of 1987, and National Appliance Energy

S-051999 0008(0X 16-OCT-90-14.03 08)

F4701.FMT.... 16.30 l...7-8-88

EE-RM-94-230 COMMENT 49M

42168 . Federal' R.~er / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 

marginal units and that using the 

average of these results is appropriate. 

The results of these tests were reported 

in the 1989,Proposal as Tables 1. 2. and. 

3. Therefore. DOE has elected to modify 

the standard as proposed in the 1989 

Proposal by lowering thefirit term ·of 

the energy factor equation for electric 

water heaters by 0.02. which is the 

· average reduction of the electric units 

tested. and by leaVing the standard for 

oil and gas water heaters unchanged. 

lnselecting this standard based on 

average test results, iUs recognized that ,. some particular marginal water heaters 

might not meet the new standard. 

It should be noted that any basic 

model that was manufactured before the 

effective date of today's final rule, 

regardless of when the individual unit 

was in fact manufactured. and which 

was certified as meeting the standard 

. using the old test procedure. is · grandfathered under NAECA as . 

complying with today's standard. 

DOE is also' concerned over the' test 

results obtained by NIST and those 

· submitted by GAMA in that for.the great 

· majorityo.f units tested. the measured 

values for energy factor were less than 

that reported in the GAMA directory. If 

this sifUation was brought to DOE's 

attention by one party complaining 

s,gainst another. DOE believes that in an 

enforcement proceeding the basic model 

could be found in noncompliance. 

m. Correction of Effective Date for 

Mobile Home Furnaces Efficiency 

Standards 

In reviewing the fmal rule regarding 

certification and enforcement of 

regulations related to energy 

conservation standards for consumer 

products published February 7. 1989. in 

the Federal Resister (54 FR 6(77). DOE 

noted that the effective date listed for 

mobile home furnaces efficiency 

standards. January 1. 1990. was 

incorrect. The correct date is September 

1. 1990. Today's notice makes that . 

correction. 

IV. Other Reviews 

A. Environmental Review 

Pursuant to.section 7(c)(2) of th~ 

Federal Energy Administration Act of 

1974 (FEAA) (15 U.s.C. 761-790). a copy 

of this notice has been submitted to the 

Administrator of the Environmental 

Protection Agency for comments 

concerning the impact, of this proposal 

on the quality of the environm~nt. 

Since the amended test pr' :edures 

under the Program will beused only to 

standardize' the measurement of energy 

usage and the energy efficiency 

standards have been adjusted 

5-0'1999 0008(00)( I~ -~14:O3:O8) 

accordingly to achieve no net change in 

energy usage. tOdaY's rule will not affect 

the quality or distribution of energy 

. usage. and will not result in any 

, environmental impacts. DOE. therefore. 

has determined that amending the test 

procedures and adjusting the energy 

efficiency standards acco~y under 

the Program do not individually or 

cumul~tively have a Significant effect on 

the human environment. Consequently •. 

neither an Environmental Impact ' 

Statement lior an Enviroiunental 

Assessment is required for today's rule. 

B. Review Under Executive Order 12291 

The fmal rule has been reviewed in 

accordance with Executive Order 12291. 

46 FR 13193 (February 19.1981). which 

directs that all regulatioris achieve their 

intended goals without imposing 

unnecessary burdens on the economy. 

on individuals. on public or private 

organizations. or onStateand local. 

governments. Executive Order 12291 

also requires that regulatory impact 

analyses be prepared for "major rules." 

which it defmes as any regulation that is 

likely to result in: (1) An annual effect 

on the economy of $100 million 'or more; 

(2) a major increase in costs Of prices for 

consumers. individual industries. 

Federal. State. or local government 

agencies. or geographic regions: or (3) 

significant adverse effects on . 

competition. employment. investment; 

productivity. innovation. or on the 

ability of the United States-based 

enterprises to compete with foreignbased enterprises in domestic or export 

markets. 

The firial nile amends already existing 

test procedures for water heaters and 

, correspondingly adjusts the energy 

efficiency standards. Accordingly. DOE 

has determined that any burden' . 

imposed on any person. industry. or 

government entity by the amendment of 

extant procedures is not Significant 

enough to bring the final rule within the 

definition of "major rule." . In. accordance with section 3(c)(3) of 

Executive Order .12291. which applies to 

rules other than major rules. the final 

rule was submitted to the Office of 

Management and Budget 10MB) for 

/ review without a regulatory impact 

analysis. 

C. Regulatory Flexibility Act 

The Reguiatory Flexibility Act. 5 

U.S.C. 601-612. requires that an agency 

prepare an initial regulatory flexibility 

analysis tobe published at the time the 

proposed rule is published. This . requirement (which appears in section 

6(3) does not apply if the agency 

"certifies that the rule will not. if 

promulgated. have a Significant 

F4701.FMT ... [16.30) ... '1-06-86 

. economic impact on a substantial 

number of small entities." DOE certified 

in the notice of proposed rulemaking. 

and does so again. that the rUle. which 

affects manufacturers of water heaters. 

will not have significant economic 

impact. but rather simply improves the 

test procedures and adjusts the related 

energy efficiency standards accordingly. 

Therefore. DOE certifies that the final 

rule. as promulg~ted. will not have a 

"significant economic impact on a . 

substantial :'lumber of.small.entities." . 

D. Federalism Review 

Executive order 12612. 52 FR 41685 

(October 30. 1987). requires that 

regulations or rules be reviewed for any. 

substantial direct effects on States. on 

the relationship between the national 

government and the States. or on the 

distribution of power and 

responsibilities among various levels of 

government. If there are sufficient . 

substantial direct effects. then Executive 

. Order 12612 requires preparation of a 

Federalism assessment to be used in all 

decisions involved in promulgating and 

implementing a regulation or a rule. 

By operation of the statute. standards 

under the Program initially preempt. 

inconsistent State regulations. Thus. in . 

theory these standards· could be said to 

have a substantial direct effect on State 

governments. Today's water heater 

standards provisions. however. have the 

practical effect of maintaining the status 

quo of the statutory standai'ds levels.· 

Thus the revised standards provisions will have no added substantive or 

negative effect on States. Based on the 

foregoing. DOE has concluded that 

preparation of a Federalism assessment 

for this rulemaking was not warranted. 

, .ist of Subjects in 10 eFR Part 430 . 

Administrative practice and 

procedure. Energy conlJervation; 

Household appliances. . 

In consideration of the foregoing. the 

Departmentaf Energy amends part 430 

of chapter U of title 10. Code of Federal 

Regulations. as set forth below. 

Issued in Wsshington. DC. October 1. 1990. 

, .. Michael Davis. 

Assistant Secretary. Conservation and 

Renewable Energy. 

PART 43D-ENERGY CONSERVATION 

. PROGRAM FOR CONSUMER . PRODUCTS 

1. The authority citation for part 430 

continues to read as follows: 

AuthoritY: EnergyPolicy and Conservation 

Ac~. title Ill. part B. 8S amended by National 

Energy Conservstion Policy Act. title IV. part 

2. National Appliance Energy Conservation 

Act of 1987. and National Appliance Energy 

" 

.. 

.. 
Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42169

Conservation Amendments of 1988 (42 U.S.C. water heater, expressed in kilowatts or Btu equipment such as fans. storage tanks.

6291-6309). per hour as appropriate. pumps, or controls necessary for the device

1.4. Energy Factor means a measure of to perform its function.

§ 430.22 lAmended] water heater overall efficiency. 1.14 ASHRAE Standard 41.1-86 means the

2. Section 430.22 is amended by 1.5. First Hour Rating means the amount of standard published in 1986 by the American

revising paragraphs (e)(1) and (e)(2) and hot water the water heater can supply in one Society of Heating, Refrigerating and Airby adding paragraph (e)(4) to read as hour of operation., Conditioning Engineers. Inc. and titled

follows: 1.6. Heat Trap means a device which can Standard Measurement Guide: Section on be integrally connected, or independently Temperature Measurements.

attached, to the hot and/or cold water pipe 1.15. ASTM-D-2156-M means the test

(e) Water Heaters. (1) The estimated connections of a water heater such that the standard published in 1980 by the American

annual operating cost for water heaters device will develop a thermal or mechanical Society of Testing and Measurements and

shall be- seal to minimize the recirculation of water titled Method for Smoke Density in Flue

(i) For a gas or oil water t tttt t the water Gases from Burning Distillate Fuels.

product of the annual energy heater tank and its connecting pipes. 1.16. "Rated Storage Volume" means the

product of the annual energy 1.7. Recovery Efficiency means the ratio of water storage capacity of a water heater, in consumption, determined according to energy delivered to the water to the energy gallons, as specified by the manufacture

section 6.1.8 or 6.2.5 of appendix E of content of the fuel consumed by the water

this subpart, times the representative heater. 2. Test Conditions

average unit cost of gas or oil, as 1.8. Standby means the time during which 2.1. Installation Requirements. Tests shall

appropriate, in dollars per Btu as water is not being withdrawn from the water b, performed with the water heater and

provided by the Secretary, the resulting heater. There are two standby time intervals instrumentation installed in accordance with

product then being rounded off to the used within this test procedure: section 4.

neappresents the elapsed time between the time 2.2. Ambient Air Temperature. The ambient

ii) For an electric water heater, the at which the maximum mean tankair temperature, shall be controlled to a value (it) For an elec watergy nc he , temperature is observed after the sixth draw between 65.0 'F and 70.0 'F on a continuous

product of the annual energy and the end of the 24 hour test: , basis. For heat pump water heaters maintain

consumption, determined according to represents the total time during the 24 hour sth dr bulb pump w at er hea ter m a 6 n ta '

section 6.1.8 or 6.2.5 of appendix E of simulated use test when water was not being Additionally, for hemperat pump water heaters theF.

this subpart, times the representative withdrawn from the water heater. relativeonally, h for eat pumidity maintained water 

average unit cost of electricity in dollars 1.9. Gas fueled storage water heater means between 49 and 51 percent.

per kilowatt-hour as provided by the a water heater which utilizes gas as the

Secretary, divided by 3412 Btu per energy source and which is designed to heat 2.3. Supply Water Temperatbeing supplied to and store water at a thermostatically temperature of the water being supplied to kilowatt-hour, the resulting quotient controlled temperature of lessan 'F the water heater shall be maintained at 58

then being rounded off to the nearest with an input of 75,000 Btu per hour or less 2 'F throughout the test.

dollar per year. and amanufacturers specified storage 2.4. Storage Tank Temperature. The

(2) The energy factor for the water capacity average temperature of the water within the

heaters shall be- than 100 gallons. storage tank shall be set to 135 ± 5 'F.

(i) For a gas or oil water heater, as 1.10 Electric storage water heater means a 2.5. Supply Water Pressure. During the test

determined by section 6.1.7 or 6.2.4 of water heater which utilizes electricity as the

appendix E of this subpart rounded off energy source and which is designed to heat supply pressure shall be maintained between appendix E othis 0.01. subparest rounded off and store water at a thermostatically 40 psig and the maximum allowable pressure

to the nearest 0.01. controlled temperature of less than 180 'F specified by the water heater manufacturer.

(ii) For an electric water heater, as with an input of 12 kilowatts or less and a 2.6. Electrical and/or Fossil Fuel Supply.

determined by section 6.1.7 or 6.2.4 of manufacturers specified storage capacity of 2.6.1. Electrical. Maintain the electrical

appendix E of this subpart rounded off not less than 20 gallons nor more than 120 supply voltage to within ± 1 percent of the

to the nearest 0.01. gallons. center of the voltage range specified by the

* .. . * .1.11 Oil storage water heater means a water heater and/or heat pump

(4) The alternative uniform test water heater which utilizes oil as the energy manufacturer.

methodfreasurngative eneor source and which is designed to heat and 2..2. Natural Gas. Maintain the supply method for measuring the energy store water at a thermostatically controlled pressure in accordance with (he consumption of untested water heaters temperature of less than 180 °F with an manufacturer's specifications. If the supply

shall be that set forth in section 7.0 of energy input of 105.000 Btu per hour or less. pressure is not specified, maintain a supply

appendix E of this subpart. and which has a manufacturers specified pressure of 7 to 10 inches of water column. If

3. Appendix E to subpart B of part 430 storage capacity of 50 gallons or less. the water heater is equipped with a gas

is revised to read as follows: 1.12 Gas fueled instantaneous water heater appliance pressure regulator, the regulator means a water heater which utilizes gas as outlet pressure shall be within ± 10% of the

Appendix E to Subpart B of Part 430- the energy source controlled manually or manufacturer's specified manifold pressure.

Uniform Test Method for Measuring the automatically by a water flow activated Use natural gas with a higher heating value of

Energy Consumption of Water Heaters control or a combination of water flow and approximately 1,025 Btu per standard cubic

thermostatic control, which is designed to foot.

I. Definitions deliver water at a controlled temperature of 2.6.3. Propane Gas. Maintain the supply

1.1. Cut-in means the time or water less than 180 'F, and which has an input pressure in accordance with the

temperature when a water heater thermostat greater than 50.000 Btu per hour and less than manufacturer's specifications. If the supply

has acted to increase the energy or fuel input 200.000 Btu per hour. and a manufacturers pressure is not specified, maintain a supply

to the heating elements. compressor, or specified storage capacity of less than 2 pressure of 11 to 13 inches of water column. If

burner. gallons. the water heater is equipped with a gas

1.2. Cut-out means the time or water 1.13 Heat pump water heater means a appliance pressure regulator, the regulator

temperature when a water heater thermostat water heater which utilizes electricity as the outlet pressure shall be within - 10% of the

has acted to reduce to a minimum the energy energy source with a maximum current rating manufacturer's specified manifold pressure.

or fuel input to the heating elements, of 24 ampe' .s at a voltage no greater than 250 Use propane gas with a higher heating value

compressor, or burners. volts, and which is designed to transfer of approximately 2.500 Btu per standard cubic

1.3. Design Power Rating means the thermal energy from one temperature level to foot.

nominal power rating that a water heater a higher temperature level for the purpose of 2.6.4. Fuel Oil Supply. Maintain an manufacturer assigns to a particular design of heating water, including all auxiliary uninterrupted supply of fuel oil. Use fuel oil

S-051999 0009(oo 16-OCT-90-1403:12)

F47O1 -FMT-rIB.3nl...7-n-RRa

EE-RM-94-230 COMMENT 49M ..... ': .... 

Federal Register I Vol. 55, No. 201. I Wednesday, October 17, 1990 I Rules and Regulations 42169 

Conservation Amendments of 1988 (42 U.S.C. 

6291~09). 

§ 430.22 [Amended} 

2. Section 430.22 is amended by 

revising paragraphs (e)(l) and (e)(2) and 

by adding paragraph (e)(4) to read as 

follows: 

(e) Water Heaters. (1) The estimated 

annual operating cost for water heaters 

shall be-

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

product of the annual energy 

consumption. determined according to 

section 6.1.8 or 6.2.5 of appendix E of 

this subpart, times the representative 

average unit cost of gas or oil. as 

appropriate. in dollars per Btu as 

prOVided by the Secretary. the resulting 

product 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 6.1.8 or 6.2.5 of appendix E of 

this subpart. times the representative 

average unit cost of electricity in dollars 

per kilowatt-hour as provided by the 

Secretary. divided by 3412 Btu per 

kilowatt-hour. the resulting quotient 

then being rounded off to the nearest 

dollar per year. 

(2) The energy factor for the water 

heaters 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 off 

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 cjf this subpart rounded off 

to the nearest 0.01. 

(4) The alternative uniform test 

method for measuring the energy 

consumption of untested water heaters 

shall be that set forth in section 7.0 of 

appendix E of this subpart. 

3. Appendix E to subpart B of part 430 

is revised to read as follows: 

Appendix E to Subpart B of Part 43c.-

Uniform Test Method for Measuring the 

Enel'lY Consumption of Water Heaters 

1. Definitions 

1.1. Cut-in means the time or water 

temperature when a water heater thermostat 

has acted to increase the energy or fuel input 

to the heatins elements. compressor. or burner. 

1.2. Cut-out means the time or water' 

temperature when a water heater thermostat 

has acted to reduce to a minimum the energy or fuel input to the heating elements. 

compressor. or burners. 

1.3. DeSign Power Rating means the 

nominal power rating that a water healer 

manufacturer assigns to a particular design of 

S~51999 0009(00)( 16-OCT -90-14:03: 12) 

water heater. expressed in kilowatts or Btu 

per hour as appropriate. 

1.4. Energy Factor means a measure of 

water heater overall efficiency. 

1.5. First Hour Rating means the amount of 

hot water the water heater can supply in one 

hour of operation. , 

1.6. 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. 

1.7. Recovery Efficiency means the ratio of 

energy delivered to the water to the energy 

content of the fuel consumed by the water 

heater. 

1.8. Standby means the time during which 

water is not being withdrawn from the water 

heater. There are two standby time intervals 

used within this test procedure: • ....... 1 

represents the elapsed time between the time 

at which the maximum mean tank 

temperature is observed after the sixth draw 

and the end of the 24 hour test; ....... .2 

represents the total time during the 24 hour 

simulated use test when water was not being 

withdrawn from the water heater. 

1.9. Gas fueled storage water heater means 

a water heater which utilizes gas as the 

energy source and which is designed to heat 

and store water at a thermostatically 

controlled temperature of less than 180 'F 

with an input of 75.000 Btu per hour or less 

and a ,manufacturers speCified storase 

capacity of not less than 20 sallons nor more 

than 100 gallons. 

1.10 Electric storage water heater means a 

water heater which utilizes electricity as the 

energy source and which is designed to heat 

and store water at a thermostatically 

controlled temperature of less than 180 'F 

with an input of 12 kilowatts or less and a 

manufacturers speCified storase capacity of 

not less than 20 sallons nor more than 120 

sallons. 

1.11 Oil storage waterheater means a 

water heater which utilizes oil as the energy 

source and which is designed to heat and 

store water at a thermostatically controlled 

temperature of less than 180 'F with an 

energy input of 105.000 Btu per hour or less. 

and which has a manufacturers speCified 

storase capacity of 50 gallons or less. 

1.12 Gas fueled instantaneous water heater 

means a water heater which utilizes gas as 

the energy source controlled manually or 

automatically by a water flow activated 

control or a combination of water flow and 

thermostatic control. which is designed to 

deliver water at a controlled temperature of 

less than 180 'F. and which has an input 

grea ter than 50.000 Btu per hour and less than 

200.000 Btu per hour. and a manufac~urers 

specified storase capacity of less than 2 

gallons. 

1.13 Heat pump water heater means a 

water heater \\'hich utilizes electricity as the 

energy source with a maximum current ratins 

of 24 ampe' .s at a voltase no greater than 250 

volts. and which is designed to transfer 

thermal energy from one temperature level to 

a higher temperature level for the purpose of 

heating water. including all auxiliary 

equipment such as fans. storage tanks. 

pumps. or controls necessary for the device 

to perform its function. 

1.14 ASH RAE Standard 41.1-86 means the 

standard published in 1966 by the American 

Society of Heatins. Refrigerating and AirConditioning EnBineers. Inc. and titled 

Standard Measurement Guide: Section on 

Temperature Measurements. 

1.15. ASTM-D-2156-80 means the test 

standard published in 1980 by the American 

Society of Testing and Measurements and 

titled Method for Smoke Density in Flue 

Gases from Burning Distillate Fuels. 

1.16. "Rated Storase Volume" means the 

water storase capacity of a water heater. in 

sallons. as specified by the manufacturp2. Test Conditions 

2.1. Installation Requirements. Tests shall 

be performed with the water heater and 

instrumentation installed in accordance with 

section 4. 

2.2. Ambient Air Temperature. The ambient 

air temperature. shall be controlled to a value 

between 65.0 'F and 70.0 OF on a continuous 

basis. For heat pump water heaters maintain 

the dry bulb temperature at 67.5 ± 1 'F. 

Additionally. for heat pump water heaters the 

relative humidity shall be maintained 

between 49 and 51 percent. 

2.3. Supply Water Temperature. The 

temperature of the water beins supplied to 

the water heater shall be maintained at 58 ± 

2 'F throuShout the test. 

2.4. Storage Tanh Temperalure. The 

average temperature of the water within the 

storage tank shall be set to 135 ± 5 'F. 

2.5. Supply Water Pressure. During the test 

when water is not beins withdrawn. the 

supply pressure shall be maintained between 

40 psiS and the maximum allowable pressure 

speCified by the water heater manufacturer. 

2.6. Electrical and/or Fossil Fuel Supply. 

2.6.1. Electrical. Maintain the electrical 

supply voltase to within ± 1 percent of the 

center of the voltase ranse specified by the 

water heater and/or heat pump 

manufacturer. 

2.6.2. Natural Gas. Maintain the supply 

pressure in accordance with ,he 

manufacturer's specifications. If the supply 

pressure is not specified. maintain a supply 

pressure of 7 to 10 inches of water c,olumn. If 

the water heater is equipped with a sas 

appliance pressure resulator. the resulator 

outlet pressure shall be within ± 1O'JL of the 

manufacturer's specified manifold pressure. 

Use natural gas with a hisher heatins value of 

approximately 1.025 Btu per standard cubic 

foot. . 

2.6.3. Prapane 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 to 13 inches of water column. If 

the water heater is equipped with a gas 

appliance pressure regulator. the resulator 

outlet pressure shall be within ~ 10% of the 

manufacturer's specified manifold pressure. 

Use propane gas with a hisher heatins value 

of approximately 2.500 Btu per standard cubic 

foot. 

2.8.4. Fuel Oil Supply. Maintain an 

uninterrupted supply of fuel oil. Use fuel oil 
42170 Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

with a heating value of approximately 138.700 calibrated thermocouple wire taken from a section shall be placed on platform(s)

Btu per gallon. single spool. Extension wires to the recording constructed as previously described. If

device shall also be made from that same installation materials are not provided by the 3. Instrumentation spooI. Instrumentationspool. heat pump manufacturer, use uninsulated 8

3.1. Pressure Measurements. Pressure 3.2.6. Time Constant. The time constant of foot long connecting hoses, having an inside

measuring instruments shall have an error no the instruments used to measure the inlet and diameter of % inch. Wall mounted water

greater than the following values: outlet water temperatures shall be no greater heaters shall be installed in accordance with

than 5 seconds. manufacturer-published installation

it"m meoans-d Instrument Insument 3.3 Liquid Flow Measurements. The instructions on a simulated wall section made

accuracy prcmon- accuracy of the liquid flow rate measurement, from % inch plywood and 2 x 4 inch studs.

~G~p ' ........ 01um o.i o ±0. using the calibration if furnished, shall be Placement in the test room shall be in an area

casp . watinch colut equal to or less than ± 1A of the measured protected from drafts.

Atmopheric 0O.1 inch of ±0.05 inch o value in mass units per unit time. 4.2. Water Supply. The water supply shall

pw srae. u mrv colrmn. mrey cokunn 3.4. Electric Energy. The electrical energy be capable of delivering water at conditions

Wantr paactl..±1.. . p.uds pW ±0.50 psunds O used shall be measured with an instrument as specified in section 2.

and associated readout device that are 4.3. Water Inlet and Outlet Configuration.

accurate within ± 1% of the reading. Inlet and outlet piping conyrctions shall be

3.2. Temperature Measurement. 3.5. Fossil Fuels. The quantity of fuel used configured as illustrated in Figures 1, 2, or 3 by the water heater shall be measured with except a water heater 36 inches high or less,

3.2.1. Measurement. Temperature an instrument and associated readout device (commonly referred to as an under counter or measurements shall be made in accordance that is accurate within ± 1% of the reading. table top model) intended for installation

with the Standard Measurement Guide: 3.6. Mass Measurements. Mass either beneath, adjacent to or in conjunction

Section on Temperature Measurements, measurements shall be made measured with with a counter shall have the inlet and outlet

ASHRAE Standard 41.1-88. instruments that are accurate within ± 1% of connections configured as illustrated in

3.2.2. Accuracy and Precision. The the reading or 0.1 Ibm. whichever is greater. Figures 4a and 4b. Type "L" hard copper

accuracy and precision of the instruments, 3.7. Heating Value. The higher heating tubing, the same size as the connections on including their associated readout devices, value of the natural gas. propane, or fuel oil the waterheater shall be connected to the

shall be within the limits as follows: shall bemeasured with an instrument andnd nd 24 inches in length. If a

1-------------L. | ,___ associated readout device that is accurate water heater 36 inchhigh or less is not ssu within of the reading. factory equippedwith pipe to extend the field

aAk oiy Precision tvalue of natural gas and propane must be connection point of the water heaer lines to

A... ±o.F corrected for local temperature and pressure outside of the jacket or cabinet, type hard tL" 

·~ wb~et utdu ~xratm.....: ~-o'F r........ =04'F conditions. Air wetn WaM Wneatw . -0.2*F ±o.F copper tubing shall be used to extend the rInlt and outlet water aenmea- 3.8. Time. The elapsed time measurements water line horizontally to the exterior of the

tme. ........ ... :......... :OF _0.1OF shall be measured with an instrument that is wackter ine horizontally to the exterior of the

stomae te~ te~mnnb ........... ~-O.S'F =0.25'F Sa k .accurate within 0.5 seconds per hour jacket or cabinet. Unions may be utilized to ------------ accurate within ±0.5 seconds per hour. facilitate installation and removal of the

4. Installation piping arrangements. A pressure gauge and 3.2.3. Scale Division. Inno case shall the ia m n s smallest scale division of the instrument or 4.1. Water Heating Mounting. A waterphragm expansiontank shall be installed

instrument system exceed 2 times the heater designed to be free standing shall be in the supply water piping at a location

specified precision. installed according to the manufacturer's upstream of the 24 inch cold water inlet pipe.

3.2.4. Temperature Difference. Temperature directions on a /4 inch thick plywood An appropriately rated pressure and

difference between the entering and leaving platform supported by three 2 x 4 inch temperature relief valve shall be installed on

water may be measured with any of the runners. If the water heater is not approved all water heaters at the port specified by the

following: for installation on combustible flooring,manufacturer. Discharge piping for the relief a. A Thermopile suitable non-combustible material shall be valve shall be non-metallic. If heat traps and/

b. Calibrated resistance thermometers placed between it and the platform. For heat or piping insulation and/or pressure relief

c. Precision thermometers pump water heaters without a storage tank valve insulation are supplied with the water

d. Calibrated thermistors supplied by the manufacturer, connections heater, then they shall be installed for testing.

e. Calibrated thermocouples shall be made with a storage tank as Clearance shall be provided such that none

f. Quartz thermometers described in section 4.9.3 and in accordance of the piping contacts other surfaces in the

3.2.5. Thermopile Construction. If a with manufacturer-published installation tet room.

thermopile is used. it shall be made from instructions. The storage tank and heat pump BLLNG cODE SO-O1-M

S-051999 0010(00X 16-OCT-90-14:03:16)

F4701.FMT...[16,30]...7-08-88

EE-RM-94-230 COMMENT 49M

42170 Federal Register l Vol. 55, No, 201 / Wednesday, October 17, 1990 I Rules ~nd Regulations 

with a heating value of apprOximately 13B,7oo 

Btu per gallon. 

3. Instrumentation 

3.1. Pressure Measurements. PressW-e 

measuring instruments shall have an error no 

greater than the follOwing values: ~ 

Gas ~ ........ ±0.1 inch 01 water COlumn. 

AIr/IOIIIII8IiC zO.1 inch 01 

~. nacury COlumn. 

w_ prascLft ..... zl.0 poundI per 

aquare inch. 

:toO.05 inch of 

water Counn 

:toO.05 inch of 

nacury COlumn 

:toO.!iO poundI per 

sqUare inch 

.. 3.2 . . Temperatlire Measurement 

3.2.1. Measurement. Temperature 

measurements shall be made in accordance 

with the Standard Measurement Guide: 

Section on Temperature Measurements, 

ASHRAE Standard 41.1~. 

3.2.2. Accuracy and Precision. The 

accuracy and precision of the instruments, 

including their associated readout devices, 

shall be within the limits as follows: 

Ail dry bulb tamperature ............... 1 

Ail_buill tamp8rature .............. 

j 

Inlet and outlet WIlla' tempera. 

s:.:-t;;k·_~b;;:::::::::::! 

Ins1rUna1I 

acc:wacy 

zO.2'F 

±O.Z'F 

±O.Z'F 

±O.S'F 

Instrument 

pnJCiSiOn 

±O.I'F 

±O.I'F 

±O.I'F 

:O.25'F 

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 

5-()51999 OOI0(00)(16-OCT-90-14:03:16) 

calibrated thermocouple wire taken from a 

single spool. Exten\lion wires to the recording 

deVice shall also be made from that same spool. .' I . 

3.2.6. Time Constant. The time constant of 

the mstruments used to measure the inlet and 

outlet water temperatures shall be no greater 

than 5 seconds. 

3.3 Liquid Flow Measurements. The 

. accuracy of the liquid flow rate measurement, 

uaingthe calibration if furnished. shall be 

equal to or less than ± 196 of the measured 

value in mass units per unit time. 

3.4. Electric Energy. The electrical energy 

used shall be measured with an wtrUment 

and aisociated readout deVice that are 

accurate within ± 1% 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 ± 196 of the reading. 

3.6. Mass Measurements. Mass 

measurements shall be made measured with 

'instruments thaf are accurate within ± 196 of 

the reading or 0.1 Ibm, whicheve~ is. greater. 

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 

value of natural gas and propane must be ~ 

corrected for local temperature and pressure 

conditions. 

3.B. Time. The elapsed time measurements 

shall be measured with an instrument that is ~ 

accurate within ± 0.5 seconds per hour. 

4. Installation 

4.1. Water Heating Mounting. A water 

heater designed to be free standing shall be 

installed according to the manufacturer's 

directions on a 0/. inch thick plywood 

platform supported by three 2 X 4 inch 

runners. If the water heater is not approved 

for installation on combustible flooring, 

suitable non-combustible materiillshall be 

placed between it and the platform. For heat 

pump water heaters without a storage tank 

supplied by the manufacturer, connections 

shall be made with a storage tank as 

described in section 4.9.3 and in accordance 

with manufacturer-published installation 

instructions. The storage tank and heat pump 

F4701.FMT ... [16.30) ... 7-06-86 

section shall be placed on platform(s) 

~ constructed as previously described. If 

installaUonmaterials are not proVided by the 

heat pump manufacturer. use uninsulated B 

foot long connecting hoses. having an inside 

diameter of lYe inch. Wall mounted water 

heaters shall be installed in accordance with 

manufacturer-published installation 

instructions on a simulated wall section made 

from 0/4 inch plywood and 2 X 4 inch studs. 

Placement in the test room shall be in an area 

protected from drafts. . 

4.2. Water Supply. The water supply shall 

be capable of delivering water at conditions 

as specified in section 2. , 

4.3. Water Inlet and Outlet Configuration. 

Inlet and outlet piping conr,ctions shall be 

configured as illustrated in Figures 1. 2. or 3 

except a water heater 36 inches high or less. 

(commonly referred to as an under counter or 

table top model) intended for installation 

either beneath. adjacent to or in conjunction 

with a counter shall have the inlet and outlet 

connections configured as illustrated in 

Figures 4a and 4b. Type "L"hard copper 

tubing, the same size as the connections on 

the water heater shall be connected to the 

tank and extend 24 inches in length. If a 

water heater 36 inches high or less is not 

factory equipped with pipe to extend the field 

connection point of the wilter heater lines to 

outside of the jacket or cabinet, tyP,e "L" hard 

copper tubing shall be used to extend the 

water line hOrizontally to the exterior of the 

jacket or cabiriet. Unions may be ·utilized 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 24 inch cold water inlet pipe. 

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 and/ 

or piping insulation and/or pressure relief 

valve insulation are supplied with the water 

heater, then they shall be installed for testing. 

Clearance shall be provided such that none 

of the piping contacts other sUrfaces in the 

test room.' . 

BlWNG CODE B4IOo01~ 

. 

.. 
Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42171

Water meter Flow

Regulator

Expa:ion Ma in

Tank

Figure 1

TOUT TIN

Check

To Scale or Valve

Water meter Flow

JSExpansi^n Main

Tank

Figure 2

TOUT

TIN

To Scale or T T. 2

Water meter Fbow

Regulator r Check

RJ s i 2H E v alwt

_ | w Water _:Supply

i Expansion Main

Tank

Figure 3

026

EE-RM-94-230 COMMENT 49M

· Federal Register / Vol. 55. No. 201 / Wednesday. October 17.1990 / RulE's and Regulations 42171 

To Scale or 

• Water met« 

To Scale or 

• Water meter 

To ScaJe or 

Water meter 

--

Flow 

Regulator 

Flow 

Regulator 

TOUT Ttf 

Figure 1 

TOUT TIN 

24- 24-

J J 

Expansion 

Tank 

Figure 2 

TIN 

Figure 3 
42172 Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

^~T^ "~TIN

29 M ^ = = = |_ waterSupply

Expansion Main

Tank

Figure 4a.

'r' To Flow - Watermeter

-' ' D ' ''

/ I

" /' I -. I| * ' " T oeor -.

Figure 4b.

SILU NG COD 00 46001,-C

O24

EE-RM-94-230 COMMENT 49M

42172 Federal Register I Vol. 55, No. 201 I Wednesday, October 17,1990 I Rules and Regulations 

T 

36" 

T 

36" 

........ -..... , " 1------, 1 1 1 

1 1 

. I I .... --... I 

, . " 

Figure 4a. 

--... ,. I.... " , 1------1 

1 1 

·1 I 

1 I I .... --... I ". " 

Figure 4b. 

BIWNQ COOl "1O-O1~ 

Expansion 

Tank 

To Scale or 

• 

Water meter 

o 16 <i .. 
Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42173

4.4. Fuel and/or Electrical Power and to the largest flue collar size of the draft hood light power, if any) after 15 minutes of

Energy Consumption. Install one or more shall be connected to the draft hood outlet. operation. If the water heater is equipped

instruments which measure, as appropriate. For gas-fired water heaters having a with a gas appliance pressure regulator, the

the quantity and rate of electrical energy horizontally discharging draft hood outlet, a regulator outlet pressure shall be set within

and/or fossil fuel consumption in accordance 90 degree elbow having a diameter equal to ±10% of that recommended by the

with section 3. the largest flue collar size of the draft hood manufacturer. For oil fired water heaters the

4.5. Internal Storage Tank Temperature shall be connected to the draft hood outlet. A fuel pump pressure shall be within ± 10% of

Measurements. Install six temperature 5 foot length of vent pipe shall be connected the manufacturer's specified pump pressure.

measurement sensors inside the water heater to the elbow and oriented to discharge All burners shall be adjusted to achieve an tank with a vertical distance of at least four vertically upward. hourly Btu rating that is within ±2% of the

inches between successive sensors. A Direct vent gas-fired water heaters shall be value specified by the manufacturer. For an temperature sensor shall be positioned at the installed wth venting equipment specified in oil-fired water heater, adjust the burner to

vertical midpoint of each of the six equal the manufacturer's instructions using the give a CO2 reading recommended by the

volume nodes with the tank. Nodes designate minimum vertical and horizontal lengths of manufacturer and an hourly Btu rating that is

the equal volumes used to evenly partition vent pipe recommended by the manufacturer. within ±2% of that specified by the

the total volume of the tank. As much as is 4.9.3. Heat Pump Water Heater Storage manufacturer. Smoke in the flue may not

possible, the temperature sensor should be Tank. The tank to bhs used for testing a heat exceed No. 1 smoke as measured by the

positioned away from any heating elements, pump water heater without a tank supplied procedure in ASTM-D-215680. Gas- and oilanodic protective devices, tank walls, and by the manufacturer shall be an electric fired water instantaneous water heaters shall

flue pipe walls. If the tank cannot storage type water heater having a volume of have the burners adjusted to the

accommodate six temperature sensors and 47.0 gallons - 1 gallon with an Energy Factor manufacture's maximum firing rate value.

meet the installation requirements specified of 0.87 ± .01 as determined in accordance 5.1.4. Firs Hour Rating Test. Establish

above, install the maximum number of with section 6.1.7 with two 4.5 kW heating normal water heater operation with the sensors which comply with the installation elements controlled in such a manner as to maximum mean tank temperature within the

requirements. The temperature sensors shall prevent both elements from operating range specified in section 2.1.4. Begin the first

be installed either through; (1) The anodic simultaneously. hour rating test after the thermostat has acted

device opening; (2) the relief valve opening;

or (3) the hot water outlet. If installed through 5. Test Procedures to reduce the electrical power or fuel input to

the water heater and the maximum storage the relief valve opening or the hot water 5.1. Storage Tank and Heat Pump Water he water heater and the maximum storage

outlet, a tee fitting or outlet piping, as Heaters.

applicable, shall be installed as close as 5.1.1. Determination of Storage Tank water heater incororate aheat-pump, wait

possible to its original location. If the hot Volume. Determine the storage capacity, V, until both the heat pump and electrical

water outlet includes a heat trap, the heat of the water heater under test, in gallons, by heating element(s) have ceased to supply

trap shall be installed on top of the tee fitting. subtracting the tare weight--measured while energy to the storage tank. Record the time,

Added fittings shall be covered with thermal the tank is empty-from the gross weight of oil, gas and/or electrical meter readings as

insulation having an R value of 4 hr.ft2 .'F/ the storage tank completely filled with water appropriate. Do not interrupt electrical power

Btu. with all air eliminated and line pressure and/or fuel to the water heater. The rate of

4.6. Ambient Temperature. The ambient air applied as described in section 2.5. and water withdrawal shall be 3.00±0.25 gallons

temperature shall be measured dividing the resulting net weight by the per minute. Draw and collect water

approximately at the vertical mid-point of the density of water at the appropriate withdrawn from the water heater in a heater and approximately 2 feet from the temperature. suitable container for the purpose of

surface of the water heater. The sensor shall 5.1.2. Setting the Thermostat for a determining its weight at the conclusion of

be shielded against radiation. Thermostatically Operated Water Heater. the test. During the draw record the inlet and

4.7. Inlet and Outlet Water Temperature Starting with a tank of supply water, initiate outlet fluid temperature beginning 15 seconds

Measurements. Install temperature sensors in normal operation of the water heater. After after the start and at every subsequent 5

the cold-water inlet pipe and hot-water outlet cutout, observe the mean tank temperature second interval throughout the duration of

pipe as shown in Figures 1, 2, or 3. as (based on the six temperature sensors) every each draw. Alternatively, a water meter may

applicable. minute until the maximum value is observed. be used to directly measure the volume of

4.8. Flow Control. A flow control valve Determine whether this maximum value of water withdrawn. Record the maximum

shall be installed to provide flow as specified the mean tank temperature is within the outlet temperature which occurs during the

within section 5. range o' 135'F _±5'F. If not. turn off the water draw as Tn. The withdrawal of water shall

4.9. Flue Requirements. heater, adjust the thermostat, and refill the continue until the outlet temperature drops to

4.9.1. Oil-Fired Water Heaters. Establish a tank with supply water. Then. initiate normal a value 25'F below T,,., defined as T,,,, at

draft at the flue collar as specified in the operation of the water heater, and once again which time the draw shall be terminated.

manufacturer's literature. Establish the draft determine the maximum mean tank Record the average outlet temperature and

by using a sufficient length of vent pipe temperature after cut-out. Repeat this mass removed as Td.I,, and Mi, respectively. If

connected to the water heater flue outlet and sequence until the maximum mean tank the thermostat acts to reduce the supply of

directed vertically upward. For an oil-fired temperature after cut-out is within the range fuel to the main burner or electrical input to

water heater having a horizontally of 135'F ±5'F. If a water heater has two the upper heating element of a multiple

discharging draft hood outlet, a 90 degree thermostats, the thermostat which controls element electric water heater, or electrical

elbow having a diameter equal to the largest the upper heating element shall be set first to input to a water heater having a single

flue collar size of the draft hood shall be yield a maximum water temperature of 135°F element or multiple elements which operate

connected to the draft hood outlet. A length ±5'F a& measured by the temperature tank simultaneously, before one hour has elapsed.

of vent pipe sufficient to establishthe draft sensors above the upper heating element. The initiate a second draw. During the draw

shall be connected t, the elbow fitting and thermostat which controls the lower heating record the outlet fluid temperatures beginning

oriented to dscharge vertically upward. element shall then be set to yield a maximum 5 seconds after initiating the draw and at

Direct vent oil-fired water heaters should be mean tank temperature of 135'F ±5'F. For every subsequent 5 second interval

installed with venting equipment as specified heat pump water heaters, which control an throughout the duration of each draw until

in the manufacturer's instructions, using the auxiliary resistance element, the thermostat the outlet temperature drops to T.mi, at which

minimum vertical and horizontal lengths of shall be set in accordance with the time the draw is terminated. Record the

vent pipe recommended by the manufacturer. manufacturer's installation instructions. average outlet temperatures as well as the

4.9.2. Gas-Fired Water Heaters. Establish a 5.1.3. Power Input Determination. For all mass removed. Continue this sequence of

natural draft in the following manner. For water heaters except electric types having events until one hour has elapsed. If a draw

gas-fired water heaters having a vertically immersed heating elements and initiate is currently taking place, continue the draw

discharging draft hood outlet, a 5 foot vertical normal operation and determine the power until the outlet temperature reaches Tim. and

vent pipe extension having a diameter equal input, P. to the main burners (including pilot record the elasped time between the

S-051999 0012(00X16-OCT-90-14.03:19)

F4701.FMT...[16,301...7-08-88

EE-RM-94-230 COMMENT 49M

Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42173 

4.4. Fuel and/or Electrical Power and 

Energy Consumption. Install one or more 

instruments which measure. as appropriate. 

the quantity and rate of electrical energy 

and/or fossil fuel consumption in accordance 

with section 3. 

4.S. Internal Storage Tank Temperature 

Measurements. Install six temperature 

measurement sensors inside the water heater 

tank with a vertical distance of at least four 

inches between successive sensors. A 

temperature sensor shall be positioned at the 

vertical midpoint of each of the six equal 

volume nodes with the tank. 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 heatin8 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; (Z) 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 

applica ble. shall be installed as close as 

possible to its original location. If the hot 

waier 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 of 4 hr·ft 2 .oF/ 

Btu. 

4.6. Am'bient Temperoture. The ambient air 

temperature shall be measured 

.approximately at the vertical mid-point of the 

heater and approximately Z feet 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. Z. or 3. as 

applicable. 

4.8. Flow Control. A flow control valve 

shall be installed to provide flow as specified 

within section S. 

4,9. Flue Requirements. 

4.9.1. Oil-Fired Water Heaters. Establish a 

draft at the flue collar as specified in the 

manufacturer's literature. 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 having a hOrizontally 

discharging draft hood outlet. a 90 degree 

elbow having 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 .1., the elbow fitting and 

oriented to d.scharge vertically upward. 

Direct vent oil-fired water heaten 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. 

4.9.Z. Gas-Fired Water Heaters. Establish a 

natural draft in the following manner. For 

gas-fired water heaten having a vertically 

discharging draft hood outlet. a S foot vertical 

vent pipe extension having 8 diameter equal 

~51999 001 2(OOXl6-OCT -9()..14:O3:19) 

to the largest flue collar size of the draft hood 

shall be connected to the draft hood outlet. 

For gas-fired water heaters having a 

horizontally discharging draft hood outlet. a 

90 degree elbow having a diameter equal to 

the largest flue collar size of the draft hood 

shall be connected to the draft hood outlet. A 

S foot length of vent pipe shall be connected 

to the elbow and oriented to discharge 

vertically upward. 

Direct vent gas-fired water heaten shall be 

installed wth venting equipment speCified in 

the manufacturer's instructions using the 

mhumum vertical and horizontal lengths of 

vent pipe recommended by the manufacturer. 

4.9.3. Heat Pump Water Heater Stol"fl6e 

Tank. The tank to "'3 used for testing a heat 

pump water heater without a tank supplied 

by the manufacturer shall be an electric 

storage type water heater having a volume of 

47.0 gallons ± 1 gallon with an Energy Factor 

of 0.87 ± .01 as determined in accordance 

with section 6.1.7 with two 4.S kW heating 

elements controlled in such a manner as to 

prevent both elements from operating 

simultaneously. 

~ Test Procedures 

S.l. Storage Tank and Heat Pump Water 

Heaters. . 

S,l.l. Determination of Storage Tank 

Volume. Determine the storage capacity. V It. 

of the water heater under test. in gallons. by 

subtracting the tare weight-measured while 

the tank is empty-from the gross weight of 

the storage tank completely filled with water 

with all air eliminated and line pressure 

applied as described in section 2.S. and 

dividing the resulting net weight by the 

density of water at the appropriate 

temperature. 

S.1.2. Setting the Thermostat for a 

Thermostatically Operated Water Heater. 

Starting with a tank of supply water. initiate 

normal operation of the water heater. After 

cutout. observe the mean tank temperature 

(based on the six temperature sensors) every 

minute until the maximum value is observed. 

Determine whether this maximum value of 

the mean tank temperature is within the 

range 0' 13SoF ±soF. If not. tum off the water' 

.heater. adjust the thermostat. and refill the 

tank with supply water. Then. initiate normal 

operation of the water heater. and once again 

determine the maximum mean tank 

temperature after cut-out. Repeat this 

sequence until the maximum mean tank 

temperature after cut-out is within the range 

of 13SOF ±S'F.1f a water heater has two 

thermostats. the thermostat which controls 

the upper heating element shall be set first to 

yield a maximum water temperature of 13SOF 

±S'F alomeasured by the temperature tank 

sensors above the upper heating element. The 

thermostat which controls the lower heating 

element shall then be set to yield a maximum mean tank temperature of 13S'F ±S·F. For 

heat pump water heaten. which control an auxiliary resistance element. the thermostat 

shall be set in accordance with the 

manufacturer's installation instructions. 

S.1.3. Power Input Determination. For all 

water heaten except electric types having 

immened heating elements and initiate 

normal operation and determine the power 

input. P. to the main burnen (including pilot 

F4701.FMT ... r16.30J ... 7-08-88 

light power. if any) after 1S minutes of 

operation. If the water heater is equipped 

with a gas appliance pressure regulator, the 

regulator outlet pressure shall be set within 

±109!i of that recommended by the 

manufacturer. For oil fired water heaters the 

fuel pump pressure shall be within ±10% of 

the manufacturer's specified pump pressure. 

All burnen shall be adjusted to achieve an 

hourly Btu rating that is within ±Z% of the 

value specified by the manufacturer. For an 

oil-fired water heater. adjust the burner to 

give a C(h reading recommended by the 

manufacturer and an hourly Btu rating that is 

within ±Z% of that specified by the 

manufacturer. Smoke in the flue may not 

exceed No.1 smoke as measured by the 

procedure in ASTM-0-2156-80. Gas- and oilfired water instantaneous water heaters shall 

have the burners adjusted to the 

manufacture's maximum firing rate value. 

S.1.4. First Hour Rating Test. Establish 

normal water heater operation with the 

maximum mean tank temperature within the 

range specified in section Z.1.4. Begin the first 

hour rating test after the thermostat has acted 

to reduce the electrical power or fuel input to 

the water heater arid the maximum storage 

tank temperature has been achieved. If the 

water heater incorporates a heat-pump. wait 

until both the heat pump and electrical 

heating element(s) have ceased to supply 

energy to the storage tank. Record the time. 

oil. gas and/or electrical meter readings 88 

appropriate. Do not interrupt electrical power 

and/or fuel to the water heater. The rate of 

water withdrawal shall be 3.00±O.ZS gallons 

per minute. Draw and collect water ' 

withdrawn from the water heater in a 

suitable container for the purpose of 

determining its weight at the conclusion of 

the test. During the draw record the inlet and 

outlet fluid temperature beginning lS seconds 

after the start and at every subsequent S 

second interval throughout the duration of 

each draw. Alternatively. a water meter may 

be used to directly measure the volume of 

water withdrawn. Record the maximum 

outlet temperature which occurs during the 

draw as T ...... The withdrawal of water shall 

continue until the outlet temperature drops to 

a value 2S'F below T ...... defined as T ...... at 

which time the draw shall be terminated. 

Record the ~verage outlet temperature and 

mass removed as Tdot.l and M" respectively. If 

the thermostat acts to reduce the supply of 

fuel to the main burner or electrical input to 

the upper beating element of a multiple 

element electric water heater. or electrical 

input to a water heater having a single 

element or multiple elements which operate 

simultaneously, before one hour has elapsed. 

initiate a second draw. During the draw 

record the outlet fluid temperatures beginning 

:S sl!conds after initiating the draw and at 

livery subsequent S second interval 

throughout the duration of each draw until 

the outlet temperature drops to T ..... at which 

time the draw is terminated. Record the 

average outlet temperatures as well as the mass removed. Continue this sequence of 

events until one hoUr has elapsed. If a draw 

is currently taking place. continue the draw 

until the outlet temperature reaches T ... D • and 

record the elasped lime between the 
42174 Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

previously recorded time, at the beginning of Tu,, and the energy consumed. Q, for oil, as appropriate. Do not interrupt electrical or the first draw, and the termination of this gas. and heat pump water heaters including · fuel to the water heater. Draw and collect

final draw as ,m If a draw is not taking place auxiliary energy such as pilot lights, pumps. water withdrawn from the water heater.

at the end of one hour. wait until the fans, etc. For heat pump water heaters Q, is while recording the inlet and outlet fluid

thermostat acts to reduce the supply of fuel to the sum of the energy consumed by the heat temperatures beginning 15 seconds after the

the main burner or electrical input to the pump and the electrical heating elements(s). draw is initiated and at every subsequent 5

upper heating element of a multiple element At the end of-the recovery period following second interval throughout the duration of

electric water heater, or electrical input to a the sixth draw, record the total electric and/ the draw in a suitable container for the

water heater having a single element or or fuel energy consumption. Qn. and the purpose of determining its weight at the

multiple elements which operate scale reading or the meter reading, as conclusion of the tet. Alternatively, a water

simultaneously, to initiate the final draw. appropriate. If a water scale is used.conclusion of the test. Alternatively, a water

During the final draw. record the outlet fluid determine the net weight of the watermeter may be used to directy measure the

temperature beginning 15 seconds after withdrawn, Mmt in pounds. Record thevalue of water withdrawn. At the end of one

initiating the draw and at every subsequent 5 maximum value of the mean tank hour terminate the draw. Determine the mass

second intervals throughout the duration of temperature after cutout as T',. Except as of water withdrawn. Mn... in pounds, or the

the draw until the outlet temperature drops to -noted below, allow thq water heater to volume of water withdrawn. Vo., in gallons

T,w. at which time the draw is terminated. remain in the standby mode until 24 hours with an error no greater than 2 percent.

Record the elasped time between the have elapsed from the start of the test., =0. 5.2.4. 24 Hour Simulated Use Test

previously recorded time, at the beginning of Prevent the water heater from beginning a the first draw, and the termination of the final recovery cycle during the last hour of the test 5.2.4.1. Fixed Input Instantaneous Water

draw as m,. In either case, record the outlet by turning off the electric power to the Heaters. Establish normal operation with the

temperatures and the mass removed during electrical heating elements and heat pump, if discharge watertemperature and flow rate

the final draw. present, or by turning down the fuel supply to set to values of 135T ± 5F and V,,

5.1.5. 24 Hour Simulated Use Test. During the main burner at an elapsed time of 23 . respectively. Record the oil, gas, and

the simulated use test, a total of 64.3 gallons hours. If a recovery is taking place at an electrical energy measurements, as are removed. With the water heater turned elapsed time of 23 hours, wait until the appropriate. Begin the 24 hour simulated use

off. fill the water heater with supply water recovery is complete before reducing the test by drawing an amount of water out of the

and apply pressure as described in section electrical and/or fuel supply to the water water heater equivalent to one-sixth of the

2.1.5. Turn on the water heater and heater. At 24 hours, record the mean tank daily not water usage. 64.3 gallons. At

associated heat pump unit, if present. Wait temperature. T'4. and the electric and/or fuel elapsed time intervals of one. two. three, four.

until cutout occurs at 135'F ±5'F, as instrument readings. Determine the total and five hours from r=0, initiate additional

specified in section 2.1.4. After the cutout energy consumption during the entire 24 hour draws removing an amount of water

occurs, measure the mean tank temperature simulated use test. Q. Record the time equivalent to one-sixth of 64.3 gallons, with

using the temperature sensors described in interval between the time at which thethe maximum allowable deviation for any section 4.5 every minute until the maximum maximum mean tank temperature is observed single draw being .. gallons. The quantity mean storage tank temperature is achieved. after the sixth draw and the end of the 24 d of water drawn during the sixth draw shall The water heater may be operated through up hour test as ,,t,;. Record the time during of waterdrawn dung the shah

to three successive cycles of drawing 10 which water was not being withdrawn from be increased or decreased a necessary such

gallons per draw. permitting recoverythe water heater duringthat the total volume of water withdrawn

between each draw, prior to the start of the shall be equal to 64.3±1.0 gallons.

test. Record at this time (designated as ,=O), Measurements of the inlet and outlet water

the mean tank temperature (.),. and the oil, 5.2 Instantaneous Water Heaters beginning 15

gas. and electrical energy measurements as . seconds after the draw is initiated and at

appropriate. Begin the 24 hour simulated use . etting the utleevery 5 second interval throughout the

test by drawing an amount of water out of the Temperature. Initiate normal operation of the duration of the draw. The arithmetic mean of

water heater equivalent to one-sixth of the water heater at the full input rating. Monitor the hot water discharge temperature and the water heater equivalent to one-sixth of thet to a daily hot water usage. 64.3 gallons. Record the dischargeTan t cold water inlet temperature shall be value of 135°F ± 5'F in accordance with the the average storage tank and ambient anufacer's instructions. f the water determined for each draw. Record the scale

temperature every 15 minutes throughout the heater is not capable of providing wor 3.00 0.25 meter reading, as appropriate, after each

24 hour simulated use test unless recovery orndraw' At the end of the recovery period a draw is occurring. At elapsed time interrals gallons per minute then adjust the flow rate aof one, two, three, four and five hours from as necessary to achieve the specified following the first draw. record the energy

of one. two, three four and five hours from discharge water temperature. Record the consumed. Q. Allow the water heater to

,=0), initiate additional draws removing an corresponding flow rate as V. If the remain in the standby mode until exactly 24

amount of water equivalent to on-sixth of instantaneous water heater incorporates a hours have elapsed from the start of the test,

64.3 gallons, with the maximum allowable 'controller which permits continous burner r=0. At 24 hours, record the electric and/or

deviation for any single draw being ±0.5 operation at a reduced input rate. adjust the fuel instrument readings. Determine the

gallons. The quantity of water drawn during flow rate as necessary to achieve a discharge energy consumption during the entire 24 hour the sixth draw shall be increased orsimulated use test. Q. water temperature of 135' ± 5'F while simulated use test. Q. decreased as necessary such that the total maintaining the minimum input rate. Record 5.2.4.2. Variable Input Instantaneous Water

volume of water withdrawn shall be equal to the corresponding flow rate. V,. If an outlet Heaters. If the instantaneous water heater

64.3 g ullons. ttemperature of 1357 ± 5'F cannot be incorporates a controller which permits All draws during the simulated use test are, achieved at the minimum allowable flow rate continuous burner operation at a reduced

to be made at flow rates of 3.0±0.25 gaLons permitted by the instantaneous water heater, input rate. the first three draws shall be

per minute. M e asureme nts of the inlet and record the flow rate as V., and the outlet conducted using the maximum flow rate.

ouscrt tompratueres shall be made nitiated temperature as T,,. V,. while removing an amount of water 15 seconds after the draw is initiated and at

every subsequent 5 second interval 5.2.2. Power Input Determinati,;'. For oil equivalent to one-sixth of 64.3 gallons, with

throughout the duration of each draw. The and gas flow actuated water heaters. adjust the maximum allowable deviation for an)

airithmetic mean of the hot water discharge the burners to the maximum firing rate value one of the three draws being ± 0.5 gallons.

temperature and the cold water inlet specified by the manufacturer. The second three draws shall be conducted

temperature shall be determined for each 5.2.3. First Hour Rating Test for at V,. If an outlet temperature of 135° ± 5T

draw. Record the scale or meter reading, as Instantaneous Water Heaters. Establish could not be achieved at the minimum flow

appropriate, after each draw. At the end of normal heater operation at the maximum rate permitted by the instantaneous water

the recovery period following the first draw, input rate with the discharge water heater, the last three draws should be

record the maximum mean tank temperature temperature set in accordance with section lengthened such that the volume removed is

observed after cut-out. 5.2.1. Record the time. oil. and/or gas meters equivalent to

S-051999 0013(00X16-OCT-90-1403:24)

F4701.FMT...[16,30]...7-08-88

EE-RM-94-230 COMMENT 49M

42174' Federal Register / Vol. 55; No. 201 / Wednesday. October 17. 1990 / Rules and Regulations 

previously recorded time. althe beginning of 

the first draw. and the termination of this 

fmal draw as f'Ibr If a draw is not taking place 

at the end of ODe hour. wait until the 

thermostat acts to reduce the supply of fuel to 

the main burner or electrical input to the 

upper heating element of a multiple element 

electric water heater. or electrical input to a 

water heater having a single element or 

multiple elements which operate 

Simultaneously. to initiate the final draw., 

During the final draw. record the outlet fluid 

temperature beginning 15 seconds after 

initiating the draw and at every subsequent 5 

second intervals throughout the duration of 

the draw until the outlet temperature drops to 

T_. at which time the draw is terminated. 

Record the elasped time between the 

previously recorded time. at the beginning of 

the first draw. and the termination of the final 

draw as f'Ibr In eithef case. record the outlet 

,temperatures and the mass removed during 

the final draw. 

5.1.5.24 Hour Simulated Use Test., During 

the simulated use test. a total of 64.3 gallons 

are removed. With the water heater turned 

off. fill the water heater with supply water 

and apply pressure as described in section 

2.1.5. Turn on the water heater and 

associated heat pump unit. if present. Wait 

until cutout occurs at 13S'F ±S·F. as 

specified in section 2.1.4. After the cutout 

occurs. measure the mean tank temperature, 

, using the temperature sensors d!!scribed in 

section 4.5 every minute until the maximum 

mean storage tank temperature is achieved. 

The water heater may be operated through up 

to three successive cycles of drawing 10 

gallons per draw. permitting recovery 

between each draw. prior to the start of the 

test. Record at this ti,'me (des,!pated as .=0). 

the mean tank temperature (To). and the oil. 

gas. and electrical energy measurements' as 

appropriate. Begin the 24 hour simulated use 

test by drawing an amount of water out of the 

water heater equivalent to one-sixth of the, 

daily hot water usage. 64.3 gallons. Record 

the average storage tank and ambient 

temp!!rature every 15 minutes throughout the 

24 hour simulated use test unless recovery or 

a draw is occurring. At elapsed time intenals 

of one. two. three. four and five hours from 

.=0). initiate additional draws removing an 

amount of water equivalent to one-sixth of 

64.3 gallons. with the maximum allowable 

deviation for any single draw being±O.S 

gallons. The quantity of water drawn during 

the sixth draw shall be increased or 

decreased as necessary such that the total 

volume of water withdrawn shall be equal to 

64.3±1.0 gallons. ' 

All draws during the simulated use test are, 

to be made at flow rates of 3.0±0.25 ga);.ons 

per minute. Measurements of the inlet and 

, outJ"t temperatures shall be made besinnins 

15 seconda after the draw is initiated and at 

every subsequent 5 second interval 

throughout the duration of each draw. The 

airithmetic mean of the hot water diacharae 

temperature and the cold water inlet 

temperature shall be determined for each 

draw. Record the scale or meter reading. as 

appropriate. after each draw. At the end of 

the recovery period following the first draw. 

record the maximum mean tank temperature 

observed after cut-out.' , 

5-051999, 0013(OOXI6-OCT-90-14:03:24) 

T ....... 10 and the energy consumed.Qr for oil. 

gas. and heat pump water heaters including 

auxiliary energy such as pilot lights. pumps. 

fans. etc. For heat pump water heaters Q .. is 

the sum of the energy consumed by the heat 

pump and the electrical heating elements(s). 

At the end of the recovery period follOWing 

the sixth draw. record the total electric and/ 

or fuel energy consumption. Q... and the 

scale reading or the meter reading. as 

appropriate. If a water scale is used. 

determine the net weight of the water 

withdrawn. Mnm in pounda. Record the 

maximum value of the mean tank 

tem;J8rature after cutout as T .... Ex~pt as 

, noted below. allow th, water heater to 

relJl8in in the standby modE! until 24 hours, ' 

hUt! elapsed from the start of the test. t =0. 

Prevent the water heater from beginning a 

recovery cycle during the last hour of the test 

by turning off the electric power to the 

, electrical heating elements and heat pump. if 

present. or by turning down the fuel supply to 

the main burner at an elapsed time of 23, 

hours. If a recovery is taking place at an 

elapsed time of 23 hours. wait until the 

recovery is complete before reducing the 

electrical and/or fuel supply to, the water 

heater. At 24 hours. record the mean tank 

temperature. 'rIO. and the electric and/or fuel 

instrument readings. Determine the total 

energy consumption during the entire 24 hour 

simulated use test. Q. Record the time 

interval between the time at which the 

maximum mean tank temperature is observed 

after the sixth draw and the end of the 24 

hour test as .ot_;,; Record the time during 

which water was not being withdrawn from 

the water heater during the entire 24 hoUr 

period as T _.2. 

5.2 Instantaneous Wpter Heaters 

5.2.1. Setting, the Outlet Discharge , 

Temperature. Initiate normal operation of the 

water heater at the full input rating. Monitor 

the discharae water temperature and set to a 

value of 13S'F ± S'F in accordance with the 

manufacturer's instructions. If the water 

heater is not capable of proViding 3.00 ± 0.25 

gallons per minute then adjust the flow rate 

as necessary to achieve the specified 

discharae water temperature. Record the 

corresponding flow rate as V ..... If the 

instantaneous water heater incorporates a 

'controller which permits continous burner 

operation at a reduced input rate. adjust the 

flow rate as necessary to achieve a discharae 

water temperature of 135' ± 5°F while 

maintaining the minimum input rate. Record 

the corresponding flow rate. V_. If an outlet 

temperature of 135' ± sop cannot be , 

achieved at the minimum allowable flow rate 

peimiued by the instantaneous water heater. 

record the flow rate as V_ and the outlet 

temperature as T_. 

5.2.2. Power Input DeterminatiL;'. P~r oil 

and gas flow actuated water heaters. adjust 

the burners to the maximum firing rate value 

specified by the manufacturer. 

5.2.3. First Hour Rating Test for 

Instantaneous· Water Heoters. Establish 

normal heater operation at the maximum 

input rate with the discharae water 

temperature set in accordance with section 

5.2.1; Record the time. oil; and/or gas meters 

F4701.FMT: .. [16.30) ... 7-D8-88 

as appropriate. Do not interrupt electrical or 

fuel to the water heater. Ora", and collect 

water withdrawn from· the water heater. 

while recording the inlet and outlet fluid 

temperatures beginning 15 seconds after, the 

draw is initiated and at every subs!!quent 5 

second interval throughout the duration of 

the draw ina suitable container for the 

purpose of determining its weight af the 

conclusion of the test. Alternatively. a w~ter 

· meter may be used to directly meas·ure the 

value of water withdrawn. At the end of one 

hour terminate the draw. Determine the. mass 

of water withdrawn. Mnu:. in pounds. or the 

volume of water withdrawn. Vra.. in gallons 

with an.error no greater,than 2 percent. 

5.2.4. 24 Hour Simulated Use Test 

5.2.4.1. Fixedlnput Instpntaneous Water 

Heaters. Establish normal operation with the 

discharae water ,temperature and flow rate 

set to values of 13S'F ± S'F and V_. 

respectively. Record the oil.' gas. and 

electrical energy measurements. as 

· appropriate. Begin the 24 hour simulated use 

test by drawing an amount of water out of the 

water heater equivalent to one-sixth of the 

daily not water usage. 64.3 gallons. At 

elapsed time intervals of one. two. three. four. 

and five hours from T=O. initiate additional 

· draws removing an amount of water 

equivalent to one-sixth of 64.3 gallons. with 

the maximum allowable deviation for any 

single draw being ±o.s gallons. The quantity 

of water drawn during the sixth draw shall 

be increased or, decreased as necessary such 

that the total volume of water withdrawn 

shall be equal to 64.3±1.0 gallons; 

Measurements of the inlet and outlet water 

temperatures shall be made beginning 15 

seconds after the draw is initiated and at 

every 5 second interval 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. Reconfthe scale 

or meter reading. as appropriate. after each 

draw. At the end olthe recovery period 

following the first draw. record the energy 

consumed. Qr Allow the water heater to 

remain in the standby mode until exactly 24 

hours have elapsed from the start of the test. 

T=O. At 24 hours. record the electric and/or 

fuel instrument readings. Determine the 

energy consumption during the entire 24 hour 

simulated use test. Q. 

5.2.4.2. Variable Input Instantaneous Water 

Heaters. If the instantaneous water heater 

incorporates B controller which permits 

continuous burner operation at a reduced 

input rate. the first three draws shall be 

conducted uiing the maximum flow rate. 

V ..... while removing an amount of water 

equivalent to one-sixth of 64.3 gallons. with 

the maximum allowable deviation for an~ 

one of the three draws being ± 0.5 gallOn!. 

The second three draws shall be conducted 

at V_. If an outlet temperature of 135° ± Sop 

could not be ·achieved at the minimum flow 

rate permitted by the instantaneous water 

heater. the last three draws should be 

lengthened such that the volume removed is 

equivalent to 
Federal Register /Vol. 55, No. 201 / Wednesday, October 17, 19g0 / Rules and Regulations 42175

64.3 T 77-F where M1represents the mass removed T, is the maximum mean tank temperature

V4 s.6 - during the ith draw of the first hour recorded prior to the first draw. 'F

6 Tm.,-58-F rating test, ibm and Q, is the total energy used by the water

Td.,.i isthe average delivery temperature for heater between cutout prior to the first

the ith draw which occurred during the draw and cutout following the first draw.

with first hour rating test, 'F including auxiliary energy such as pilot the elasped time recorded lights, pumps, fans, etc., Btu. (Electrical

any one of the qathreeo draws being + 05n during the first hour rating test, minutes auxiliary energy shall be converted to

gallons. The quantity of water drawn oT., during is the average inlet temperature for the thermal energy using the following the draw shall be increased or sixth 

decreased as necessay su ca o ith draw which occurred during the first conversion: kWh = 3412.7 Btu.) decreased as necessary such that the total hour rating test. 'F covery efficiency for electric water volume of water withdrawn shall be equal to rresen effiiensity reesety The for electric water

32.15 + 3'V4.._.+1.0 gallons. Measurements average delivery temperature, Ibm/gal heaters with immersed heating elements is

of the inlet and outlet water temperatures and n represents the number of draws which assumed to be 98 percent. shall be made beginning 15 seconds after the occur during the test If a water meter is 6.1.4. Hourly Standby Losses. The hourly draw is initiated and at every 5 second used in lieu of a scale, the first hour standby losses are computed as interval throughout the duration of the draw.t

Determine the arithmetic mean of the hot ra is

water discharge temperature and the cold

water inlet temperature for each draw. 60 n Vt(tl,.i-T.. } Q.r = Qw _ MCpT2-T 4b4.J / 

Record the scale or meter reading.'as Fhr= - I

appropriate, after each draw. At the end of rni i= 77'F

the recovery period following the first draw.

record the energy consumption. Qr. m. where Qhr is the hourly standby energy losses

Record the energy consumed prior to the where V, represents the volume removed of the water heater, Btu/hr

fourth draw and at the end of the recovery during the ith draw of the first hour Q,, is the total energy consumer by the

period following the fourth draw, Q,. m. rating test, gal water heater between the time at which

Allow the water heater to remain in the 6.1.3 Recovery Efficiency. The recovery the maximum mean tank temperature is

standby mode until exactly 24 hours have efficiency for gas, oil, and heat pump storage observed after the sixth draw and the

elapsed from the start of the test, r=0. At 24 type water heaters is computed as end of the 24 hour test period, Btu

hours. record the electric and/or fuel M is the mass of the water within the storage instrument readings. Determine the energy tank, Ibm

consumption during the entire 24 hours MiC,{(Td.1 1-T , in. C, is the specific heat of water at the average simulated use test, Q. - temperature (T2 + T,J/2, Btu/lbm 'F

6 Computations Q, T24 is the mean tank temperature at the end

6. - ~~~~~~~~~~~~~~Computations Q~ ,of the 24 hour test period, 'F 6.1 Storage Tank Water Heaters. T., is the maximum mean tank temperature 6.1.1. Storage Tank Capacity. The storage observed after the sixth draw. 'F

tank capacity is computed using the

following-v and r,t,,l is the elapsed time between the following-- v.pV,tpC{(Tmu.-To) time at which the maximum mean tank

Vt- =(W,-Wt)/p + temperature is observed after the sixth

where V, is the storage capacity of the water Qr draw and the end of the 24 hour test

heater, gallons period, hours

W,is the weight of the storage tank The standby heat loss coefficient for the

completely filled with water. ibm where M1 is the mass withdrawn during the tank is computed as- W, is the tare weight of the empty storage first draw. Ibm

tank. Ibm

p is the density of water at the appropriate C, 1 is the specific heat of water at the

temperature. Ibm/gal. average temperature (T.d,, +T1 ,.,)/2. btu/ UA = Q"

6.1.2. First Hour Rating Computation. Ibm F ..tb- ..itb

Compute-the first hour rating as Tee., is the average delivery temperature for

the first draw. '*F fwhere T,.., is the average storage tank

60 n MI(Td.I. .- T. T is the average inlet temperature for the teperature between the time at which _0 n_ Ifirst - --------- -T _ draw 'F the maximum mean tank temperature is

Fh, = r, ' p(135'F-58'F) V,, is the storage tank capacity, gal observed after the sixth draw and the i=l p is the density of water at the average end of the 24 hour test period. 'F

temperature (T., +T.)/2. Ibm/gal T.,..>, is the average ambient temperature

Which may be expressed as C1 is the specific heat of water at the between the time at which the maximum

average temperature (TT., +T.)/2. Btu/ mean tank temperature is observed after

Ibm 'F the sixth draw and the end of the 24 hour

60 n Mi(Tj.. i-T'.,) T.., is the maximum mean tank test period. 'F

pFh = I I p(77'F) temperature recorded after cutout and UA it ;he standby heat loss coefficient of

Fi, =i= following the first draw, 'F the storage tank.

S-051999 0014(00)(16-OCT-90-14:03:28)

F4701.FMT...[16,301...7-08-88

EE-RM-94-230 COMMENT 49M ;, 

. ~ .. 

Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 I Rdes and Regulations. 42175 

V •.•. 6 ~ 64

6

.3 ,[ __ 77_'_F __ ] 

TmID-58'F 

with the maximun allowable definition for 

anyone of the three draws being ± 0.5 

gallons. The quantity of water drawn during 

the sixth draw shall be increased or 

decreased as necessary such that the total 

volume of water withdrawn shall be equal to 

32.15 + 3'Vu .• ±1.0 gallons. Measurements 

of the inlet and outlet water temperatures 

shall be made beginning 15 seconds after the 

draw is initiated and at every 5 second 

interval throughout the duration of the draw. 

Determine the arithmetic mean of the hot 

water discharge temperature and the cold 

water inlet temperature for each draw. 

Record the scale or meter reading, 'as 

appropriate. after each draw. At the end of 

the recovery period following the first draw, 

record the energy consumption. Qr ...... 

Record the energy consumed prior to the 

fourth draw and at the end of the recovery 

period following the fourth draw. Qr.mln' 

Allow the water heater to remain in the 

standby mode until exactly 24 hours have 

elapsed from the start of the test. T=O. AI 24 

,hours. record the electric and/or fuel 

. instrumen t readings. Determine the energy 

consumption during the entire 24 hours 

simulated use test. Q, 

6. Computations 

6.1 Storage Tank Water Heaters. 

6.1.1. Storage Tank Capacity, The storage 

tank capacity is computed using the 

followingV ... = (W,-Wll/p 

where V'l is the storage capacity of the water 

hea ter. gallons 

Wris the weight of the storage tank 

completely filled with water, 1bm 

W, is the tare weight of the empty storage 

tank.1bm 

p is the density of water at the appropriate 

temperature.1bm/gal. 

6.1.2. First Hour Rating Computation. 

Compute. the first hour rating as 

60 

Tlbr 

n 

I 

i=l 

p(135°F - 56' F) 

Which may be expressed as 

S~51999 

60 

Tlbr 

n 

I 

i=l 

p(77'F) 

0014(00)( 16-OCT -90-14:03:28) 

where MI represents the mass removed 

diJring the ith draw of the first hour 

rating test. 1bm 

Tdel. I is the average delivery temperature for 

the ith draw which occurred during the 

first hour rating test. OF . 

Tlbr represents the elasped time recorded 

diJring the first hour rating test, minutes 

l' 1a.1 is the average inlet temperature for the 

ith draw which occurred diJring the first 

hour rating test. OF 

p represents the density of water at the 

average delivery temperature. Ibm/gal 

'and n represents the number of draws which 

occur during the test If a water meter is 

used in lieu of a scale. the first hour 

rating is 

60 n VI(Tdel.l-Tln.l ) 

Fhr= __ .I 

TIb. i = 1 77'F 

where VI represents the volume removed 

during the ith draw of the first hour 

rating test. gal 

6.1.3 Recovery Efficiency. The recovery 

effiCiency for gas. oil. and heat pump storage 

type water heaters is computed ali 

'l'/r 

M. Cp. (1' del.1 - TID . .) 

Q. 

V,lP~(Tmu .• -To) +----'--------

where M. is the mass withdrawn during the 

first draw. Ibm 

Cp ' is the specific heat of water at the 

average temperature (Tdel.1 + Tln . .)/2. btu/ 

Ibm 'F 

1'.,., is the average delivery temperature for 

the first draw. 'F 

t,n .• is the average inlet temperature for the 

first draw. OF 

V" is the storage tank capacity. gal' 

p is the density of water at the average 

temperature (T...,..I + 1'01/2. Ibm/gal 

C", is the specific heat of water at the 

average temperature (T...,. .• +To)/2.Btu/ 

Ibm 'F . 

T ..... 1 is the maximum mean tank 

temperature recorded after cutout 

following the first draw. OF 

F4701.FMT ... r16.301 ... 7-08-88 

to is the maximum mean tank temperature 

recorded prior to the first draw. OF 

and Qr is the total energy used by the water 

heater between' cutout prior to the first 

draw and cutout following the first draw. 

including auxiliary energy such as pilot 

lights. pumps. fans. etc .• Btu. (Electrical 

auxiliary energy shall be converted to 

thermal energy using the following 

conversion: 1kWh = 3412.76 Btu.) 

The recovery efficiency for electric water 

heaters with immersed heating elements is 

assumed to be 98 percent. 

6.1.4. Hourly Standby Losses. The hourly 

standby losses are computed as 

where Qhr is the hourly standby energy losses 

of the water heater. Btu/hr 

Q.l'" is the total energy consumer by the 

water heater between the time at which 

, the maximum mean lank temperature is 

observed after the' sixth draw and the 

end of the 24 hour test period. Btu 

M is the mass of the water within the storage 

tank. Ibm 

C. is the specific heat of water at the average 

temperature (t2' + 1' •• )/2. Btu/Ibm 'F 

1'24 is the mean tank temperature at the end 

of the 24 hour test period. OF 

1' •• is the maximum mean tank temperature 

observed after the sixth draw. OF 

and T.l .... 1 is the elapsed time between the 

time at which the maximum mean tank 

temperature is observed after the sixth 

draw and the end of the 24 hour test 

period. hours 

The standby heat loss coefficient for the 

tank is computed asVA 

where 1' ....... is the average storage tank 

temperature between the time at which 

the maximum mean tank temperature is 

observed after the sixth draw and the 

end of the 24'hour test period. 'F 

_ 1' ....... is the average ambient temperature 

between the time at which the maximum 

mean tank temperature is observed after 

the sixth draw and the end of the 24 hour 

test period. 'F 

and VA it .he standby heat loss coefficient of 

the storage tank. 
42176 Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

BT8U 6 T is the average inlet temperature. 'F

hr--. -'FQ~ _2 MIC,1 (T,.I 1- Tins.,) and p represents the density of water at the

h

r "F Q"R -, *»; ' average delivery temperature, Ibm/gal

If a water meter is used in lieu of a scale

6.1.5. Daily Water Heating Energy the first hour rating is computed as- Consumption. The daily water heating energy where MI is the mass withdrawn for the ith

consumption. Qd is computed as draw (i=1 to . Ibm-Tn C,, is the specific heat of water, Btu/lbm 'F

The energy required'to heat the same 77'F

-C PMt-fo) quantity of water over a 77 'F

Qd=Q - --- temperature rise,, Btu per day, is

1t where V represents the volume of water

removed during the one hour continuous

where Q is the total energy used by the water 6 M C, (135 F -58 )draw gal

heater during the 24 hours simulated use Q .

test including auxiliary energy such as i1 6.2.2. Recovery Efficiency

pilot lights, pumps' fans, etc., Btu pilot lights, pumps. fans, etc.. Btu 6.2.2.1. Fixed Input Instantaneous, Water

C, is the specific heat °of water at the average The difference between these two values Heaters. The recovery efficiency is computed temperature (T{,i+T.)/2. Btu/lbm F is- as M is the mass of water within the storge tank,

Ibm QMrI =Qiw.-n-QHW

T24 is the average tank temperature at the which must be added to the adjusted daily _

conclusion of the 24 hours simulated use water heating energy consumption value. 1= MiCpl(TdeI.l-T,. I)

test, 'F Thus, the daily energy consumption value

To is the average tank temperature at the which takes into account that the - Q

beginning of the 24 hours simulated use temperature difference between the storage

test, recorded one minute before the first tank and ambient temperature may not be where Mi is the mass withdrawn during the

draw is initiated 'F 67.5'F and the temperature rise across the first draw Ibm

and 71, is the recovery efficiency of the hot storage tank may not be 77'-F C is-s the specific heat of water at the

water heater, dimensionless. average temperature (Td.i.1 + 1,i.i)/2, 6.1.6. Adjusted Daily Water Heating Qdm=Qd.+QHW m Btu/lbm'F

Energy Consumption. The adjusted daily 6.1.7. Energy Factor. The energy factor, EF Ti., is the average delivery temperature for

water heating energy consumption, Qd. takes is computed as- the first draw 'F

into account that the temperature difference T, is the average inlet temperature for the

between the storage tank and surrounding8 first draw'

ambient temperature may not be the nominal ' 6 MC.4135'F-58'F) first draw, 'F ambient temperature may not be the nominal Ef -I - and Q, is the total energy used by the water value of 67.5'F (135'F - 67.5'F) due to the i andheater between cutout prior to the first

10'F allowable variation in storage tank Qd 10te allowablre.va5r-a- niand sthrae tak ~draw and cutout following the first draw, temperature. 135 ± 5'F, and the 5'Fincluding auxiliary eney such as pilot allowable variation in surrounding ambient including auxiliary energy such as pilot ~~~~~~allowable ambientlights, van~ation in surrounding pumps, fans, etc., Btu

temperature 65'F to 70'F. The adjusted daily where Qd, is the modified daily water, pumps, ans etc. Btu

water heating energy consumption is heating energy consumption as computed 6.2.2.2. Variable Input Instantaneous Water

computed as in accordance with Section 6.1.6, Btu Heaters

6.1.8. Annual Energy Consumption For instantaneous water heaters which

Qda= Qd-t(Ttbs -Tsi..W·J- haAe a variable firing rate, two recovery The annual energy consumption for storage have a va Theanntialenergyconsumptionforstorage efficiency values are computed, one at the (135'F-67.5-F)]UA7,,, -, type and heat pump water heaters is efficiency values are computed, one at the icomputed as- «»»-«'.yimaximum input rate and one at the minimum computed as- where.Qd, is the adjusted daily water heating -- 365input rate. The recovery efficiency used in

-consumpdtion, Btu i wt hEn. '365 m subsequent computations is taken as the

T,,,, is the mean tank temperature during the where Qd. is the modified daily energy average of these two values. The maximum

total standby portion, v.b.s, of the 24 consumption value. Btu per day and 365 recovery efficiency is computed as total standby portion, s,.2. of the 24

hour test. 'F is the number of days within a year. days

T,.,,,, is the average ambient temperature 6.2. Instantaneous Hot Water Heaters.

during the total standby portion, r,., of 6.2.1. First Hour Rating Computation. MCo (Td..- T.. I)

the 24 hour test.°F Compute the first hour rating as. UA is the standby heat loss coefficient for the C .

storage tank, Btu/hr'F - and rT,. is the number of hours during the M(T.- w n d g

24 hour simulated test when water was F 35 5where M is the mass withdrawn during the p(135'F-58'F]' ' first draw. Ibm ' not being withdrawn from the water C,, is the specific heat of water at the

~~~~~~~~~~~heater ' ' ' ' ~~~~~~~average temperature (T..i. +T,.. 1)/2, A modification is also needed to take into which may be expressed as- Btu/lbm' e

account that the temperature difference T., is the a. arage delivery temperature for

be' 'een the outlet water temperature andM(t.,-T.) the first draw, * sup, ly water temperature may not be F ' l Tn.l is the average inlet temperature for the

equivalent to the nominal value of 77'F p(77-F)first draw 'F

(135'F-58'F). The following equations adjust and Q,., is the total energy used by the

the experimental data to a nominal 77'F .water heater between cutout prior to the

temperature rise. where M represents the mass removed during first draw and cutout following the first

The energy used to heat water. Btu per day. the one hour continuous dra- .Ibm draw including auxiliary energy such as may be computed as-- Td, is the average delivery temperature. 'F pilot light. Btu

EE-RM-94-230 COMMENT 49M

42176 Federal Register I Vol. 55. No; 201 {Wednesday, October 17, 1990 { Rules and Regulations 

BnJ 

hr 'F 

6.1.S. Daily Water Heating Ene1'lJY 

Consumption. The daily water heating energy 

'consumption. Q .. is computed as 

Q..=Q 

'IJ. 

where Q is the total ene1'lJYused by the water 

heater dlll'inl! the 24 hoUrs simulated use 

test including auxiliary ene1'lJY such as 

pilot lights. pumps; fans. etc .. Btu 

C, is the specific heat of water at the average 

temperature (1' •• + t ol/2. Btu/Ibm 'F 

M is the mass of water within the stol'l!e tank. 

Ibm' , 

,1',. is the average tank temperature at the 

conclusion of the 24 hours simulated use test.·F ' 

to is the average tank temperature at the, 

beginning of the 24 hours simulated use 

test. recorded one minute before the first 

, ,draw is initiated 'F . 

and 'IJ. is the recovery efficiency of the hot 

water heater. dimensionless. ' 

6.1.6. Adjusted Daily Water Heating 

Energy Consumption. The adjusted daily 

water heating ene1'lJY consumption. Q ... takes 

into account that the temperature difference 

between the storage tank and surrounding , 

ambient temperature may not be the nominal 

value of 67.S'F (13S'F - 67.S·F) due to the 

10'F allowable variation in storage tank , 

temperature. 13S ± S'F. and the S9F 

allowable variation in surroundirll! ambient 

temperature 65'F to 70·F. The adjusted daily 

water heating,enel'l!Y consumption is 

computed ,as 

Q ... =Q .. -[(t ...... -t ........ J-

(13S'F -67.S'F)JUAT ...... .2 

where,Q ... is the adjusted daily water heating 

. consumption. Btu , 

f ...... iii the mean tank temperature during the 

total standby portion. T ....... '. of the 24 

hour test. 'F , 

f ........ is-the average ambient temperature , 

, durirll! the total.standby portion. T ....... '. of 

the 24 hour test. 'F' 

UA is the standby heat loss coefficient for the 

storage tank. Btu/hr'F 

and T ...... .2 is the number of hoUrs during the 

24 hour simulated test when water was 

not being withdrawn from the water 

heater 

A modification is also needed to take into 

account that the temperature difference' ' 

be' 'een the outlet water temperature and 

, sup.ly water temperahire may not be , 

equivalent to the nominal value of 77'F 

(13S'F - 58'F). The following equations adjust, 

the experimental data to a nominal 77'F 

temperature rise. 

The ene1'lJY used to heat water. Btu per day. 

may be computed asQIIW 

i=l 

MI<:.t('t ... I.I-Tlft.11 

'IJ. 

where MI is the mass withdrawn for the ith 

draw (i=l to 61. Ibm 

Cpl is the specific heat of water. Btu/Ibm 'F 

The ene1'lJY required' to heat the same 

quantity of water over a 71 ')1 

,temperature rise. Btu pe~ day, is 

6 

~. TT = 1: 

i=1. 

M.'c. (13S 'F - 58, 'F) 

'lIT, 

The difference between these two values 

isQRWD =QIIW:n..,.QIIW 

which must be added to the adjusted daily 

water heating ene1'lJY consumption value. 

Thus. the daily ene1'lJY consumption value 

which takes into account that the 

temperature difference between the storage 

tank and ambient temperature may not be 

67.S'F and the temperature rise across the 

storage tank may not be 77'F isQdlD =Q ... +QRWD , 6.1.7. Ene1'lJY Factor. The ene1'lJY factor. E,. 

is computed as6 MtC,I(13S'F-58'F) 

E, 1: ' ------

i=,i Q_ 

where Q ..... is the modified daily water 

, heating ene1'lJY consumption as computed 

, in accordance with Section 6.1.6. Btu 

,6.1.8. AnnualEhergy Consumption 

The annual ene1'lJY consumption for storage 

type and heat pump water heaters is 

computed asE...D~ = Q_ '36S 

where Q ... is the modified daily ene1'lJY 

, consumption value. Btu per day and 365 

is the number of days within a year. days 

6.2. Instantaneous Hot, Water Heaters. 

6.2.1. First Hour Rating Computation. 

Compute the first hour ratirll! as , 

, M(f ",1-tlDI 

p(13S'F -56'F) " 

which may be expressed asMrt .... -f'ftl 

pl77'FI 

where M represents the mass removed during 

the one hour continuous dra' • Ibm 

tllol is the average delivery temperature. 'F 

tbl is the average inlet temperature. 'F 

andp represents the density of water at the 

averqedelivery temperature. Ibm/gal 

If a water meter is used in lieu of a scale 

the first hour ratirll! is computed as77'F 

wh~re V represents the volume of water 

removed during the one hour continuous 

draw. gal ' 

6.2.2. Recovery Efficiency 

6.2.2.1. Fixed Input Instal!taneous, Water 

Heaters. The recovery efficiency is computed 

as 

Q. 

where MI is the mass withdrawn during the 

first draw. Ibm 

C,I is the speCific heat of water at the 

average temperature (f ... ,.,+f",.tl/2. 

Btu/lbl'!l'F 

, 1' ... 1.1 is the 'average delivery temperature for 

the first draw. OF 

f 1D.1 is the average inlet temperature for the 

flJ'st draw. 'F 

and Q. is the total ene1'lJY used by the water 

, heater between cutout prior to the first 

draw and cutout following the first draw. 

including auxiliary ene1'lJY such as pilot 

lights. pumps. fans. etc .• Btu 

6.2.2.2. Variable Input Instantaneous Water 

Heaters 

For instantaneous water heaters which 

have a variable firing rate. two recove'ry 

efficiency values are computed. one at the 

maximum input rate and one at the minimum 

input rate. The recovery efficiency used in 

subsequent co~putations is taken ,as the 

average of these two values. The maximum 

recovery efficiency is computed as 

Q ...... 

where MI is ihe mass withdrawn during the 

first draw. Ibm ' 

Cpa is the specific heat of water at the 

average temperature ITd.I.1 + T'ft .• )/Z. , Btu/Ibm OF 

1' ... 1.1 ill the a\ aralle delivery temperature for 

the first draw. 'r. 

f," .• is the average inlet temperature forthe 

first draw. OF ' ' 

and Q ....... is the total ene1'lJY used by the 

water heater between cutout prior to the, 

first draw and cutout follOWing the first 

draw. including auxiliary ene1'lJY such as 

pilot light. Btu 
Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42177 ¢ l

The minimum recovery efficiency is QHWm=QHw.7-Qa first hour rating shall be equivalent to that

computed as- which must be added to the daily water measured for the water heater with the

heating energy consumption value. Thus, the standard input rating.

MCXT.., 4-Ti,,.1) daily energy consumption value which takes 7.2.2. Energy Factor. The energy factor for

-=^~~~ *'*into ^" account that the temperature rise across identical electric storage type water heaters.

7'tr.mm ~ ~ D= ~the storage tank may not be 77 'F is- with the exception of heating element '

< Qr* B

-min wattage. may use the energy factor obtained

QmQmQi tw Q ,=Q rduring r at testing of the water heater with the

6.2.4. Energy Factor. The energy factor. E, designated standard input rating.

where M is the mass withdrawn during the i

s computed as- fourth draw, Ibm § 430.31 [Amendedl

C,, is the specific heat of water, Btu/lbm °F 4. Section 430.31. Purpose and Scope,

T.I.4 is the average delivery temerature for 6 MC,(135'F-58'F) is amended by adding the following ~the fourth I~ draw-, *F E, = I sentence at the end of the section to

t, 4 is the average inlet terrerature for the i=1 Qt read as follows:

first draw, 'F

and Q,., is the total energy consumed where is the daily water heating energyBasic models of covered

immediately prior to tL fourth draw and consumption as computed in accordance products manufactured before the date

cutout following the fourth draw. with section 6.2.3., Btu on which an amended energy

including auxiliary energy such as pilot M, is the mass associated with the ith draw, conservation standard becomes

lights. Btu Ibm effective (or revisions of such models

The recovery efficiency is computed as- Ci is the specific heat of water computed at a manufactured after such date and have

temperature of (58 F+135 'F)/2, Btu/lbm the same energy efficiency or energy use

_ ,_ - F, .11. . r characteristics) that comply with the ___._=+7__ ,.,_- Td.1

, is the average delivery temperature for r . + ith ra delivery temperature for energy conservation standard applicable

2 and Ti,. is the average inlet temperature for to such covered products on the day

the ith draw, 'F before such date shall be deemed to

6.2.5. Annual Energy Consumption. The comply with the amended energy 6.2.3. Daily Water Heating Energy annual energy consumption for instantaneous conservation standard.

Consumption. The daily water heat e type water heaters is computedas- § 430.32 [Amended]

consumption. Qd is computed as- § 365

Qd=Q El.=, Q 365 5. Section 430.32. Energy conservation

where Q is the enerwhere usd by the ow is modified daily energy standards and effective dates, is

actuated water heater during the 24 hour and sumption Btu per of dayamended by revising paragraph d and

simulated use test days by revising the effective date of entry

A modification is needed to take into "2." in paragraph (e) to read "09/01/90."

account that the temperature difference 7 Ratings for Untested Models The revised paragraph (d) reads as set

between the outlet water temperature and In order to relieve the test burden to forth below:

supply water temperature may not be manufacturers who offer water heaters which * * . equivalent to the nominal value of 77 'F (135 differ only in fuel type or power input, ratings 'F-58 'F). The following equations adjust the for untested models may be established in (d) Water heaters.

experimental data to a nominal 77 'F accordance with the following procedures. In The energy factor of water heaters

temperature rise, lieu of the following procedures a shall not be less than the following The energy used to heat water may be manufacturer may elect to test the unit for products manufactured on or after the

computed as- which a rating is sought.indicated dates:

7.1. Gas Water Heaters. Ratings obtained

for gas water heaters using natural gas can 6 M T T,. be used for an identical water heater which Product class Enery actor as Energ factor as

0 MC,,(Te.,.-T sna utilizes propane gas if the input ratings are of Jan. 1, 1

i=1 within 10 percent. 1. Gas Water 0.62-(.0019x 0.62-(.0019x

7.2 Electric Water Heaters Heter. Rated Storage Rated Storage 7.2. Electric Water Heaters Volume in Volume in

7.2.1. First Hour Rating. If an electric gallons). gallons).

storage type water heater is available with 2. Oil Water 0.59-(.0 0 '

9X 059-(.oo019 The energy required to heat the same orHeater. Rated Storage Rated Storage more than one input rating, the manufacturer volume in Volume in quantity of water over a 77 °F temperature shall designate the standard input rating and gallons) gallons). rise is- the water heater need only be tested with 3. Eletnc Water 0.95-(.00132x i 0.93-(.00132,

heating elements at the designated standard Heaolume in Storage in

input ratings. The first hour ratings for units gallons). gallons):

M,(135-F - 58'F) having power input rating less than the

QV.77r = I designated standard input rating shall be ROte: Rated Storage Volume=the water storage capacity of a water heater. in gallons, as specified by the manufat J- i= 1 ), assigned a first hour rating equivalent to the er. first draw of the first hour rating for the . . . . . electric water heater with the standard input

The difference between these two values rating. 'or units having power inputs greater IFR Doc. 90-24134 Filed 10-16-90: 8:45 aml

is- - than the designated standard input rating, the sILuN cooE 64so-o1-

S-051999 0016(00)( 16OCT-90-14.03:36)

F4701.FMT...[16.301...7-08-88 dSA / PM / J

EE-RM-94-230 COMMENT 49M

Federal Register / Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulation~ 42177 

The minimum recovery efficiency is 

computed asM.G.,.(T..o •. '-f ..... ) 

Qr.lllla 

where M. is the mass withdrawn during the 

fourth draw, Ibm 

CpO is the specific heat of water. Btu/Ibm OF 

f do ••• is the averaRe delivery temperature for 

the fourth draw. 'F 

fin.' is the average inlet tel7' "erature for the 

first draw, OF 

and Qr._ is the total energy consumed 

immediately prior to tL fourth draw and 

cutout following the fourth draw. 

incIudins auxiliary energy such as pilot 

lights. Btu ' 

The recovery efficiency is computed as-

"I", .. u+ "Ir._ 

"I, 

2 

6.2.3. Daily Water Heating Energy 

Consumption. The daily water heating energy 

consumption. Qd is computed asQd=Q 

where Q is the energy used by the flow 

actuated water heater durinS the 24 hour 

simulated use test . 

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 77 OF (135 

of -58 OF). The following equations adjust the 

experimental data to a nominal 71 OF 

temperature rise. 

The energy used to heat water may be 

computed asQHW 

6 

.I 

i=1 "I, 

The energy required to heat the same 

qUllntity of water over a 77 of temperature 

rise is6 

.I 

i=1 "Ir 

The difference between these two values 

isS~51999 OOI6(OO)(I(K)C1' -90-14:03:36) 

QHWD=QIIW.71-QIIW 

which must be added to the daily water 

heating energy consumption value. Thus, the 

daily energy consumption value which takes 

into account that the temperature rise across the storage tank may not be 77 of isQ .... =Q.+QHWD 

6.2.4. Energy Factor. The energy factor. E" 

is computed as6 

I M.c,..(135·F -58'F) 

i=1 Q ..... 

where Qdm is the daily water heating energy 

, consumption as computed in accordance 

with section 6.2.3 .• Btu 

MI is the mass associated with the ith draw. 

Ibm 

c". is the specific heat of water computed at a 

temperature of (58 of + 135 °F)/2. Btu/Ibm 

of 

fdot.l is the average delivery temperature for 

the ilh draw. OF 

and fin. I is the average inlet temperature for 

the ith draw. OF 

6.2.5. Annual Energy Consumption. The 

annual energy consumption for instantaneous 

type water heaters is computed·asE.....IIIII=Q ..... • 365 

where Q ..... is the modified daily energy 

consumption. Btu per day 

and 365 is the number of days within a year. 

days. 

7. Ratings for Untested Models 

In order to relieve the test burden to 

manufacturers who offer water heaters which 

differ only in fuel type or power input. ratings 

for untested models may be established in 

accordance with the following procedures. In 

lieu of the following procedures a 

manufacturer may elect to test the unit for 

which a rating is sought. 

7.1. Gas Water Heaters. Ratings obtained 

for gas water heaters using natural gas can 

be used for an identical waler heater which 

utilizes propane gas if the input ratings are within 10 percent. 

7.2. Electric Water Heaters 

7.2.1. First Hour Rating. If an electric 

storage type water heater is available with 

more than one input rating. the manufacturer 

shall desisnate the standard input rating and 

the water heater need only be tested with 

heating elements at the designated standard 

input ratings. The first hour ratings for units 

having power input rating less than the 

desisnated standard input rating shall be 

8ssisned a first hour rating equivalent to the 

first draw of the first hour rating for the 

electric water heater with the standard input 

rating. ":'t)r units having power inputs greater 

than the JesiRnated standard input rating. the 

F4701.FMT ... [16.30) ... 7-D8-88 

first hour rating shall be equivalent to that 

measured for the water heater with the 

standard input rating. 

7.2.2. Energy Factor. The energy factor for 

identical electric storase type water heaters. 

with the exception of heating element 

wattage. may use the energy factor obtained 

durinS testins of the water heater with the 

desisnated standard input rating. 

§ 430.31 [Amended] 

4. Section 430.31. Purpose and Scope. 

is amended by adding the following 

sentence at the end of the section to 

read as follows: 

• • • Basic models of covered 

products manufactured before the date 

on which an amended energy 

conservation standard becomes 

effective (or revisions of such models 

manufactured after such date and have 

the same energy efficiency or energy use 

characteristics) that comply with the 

energy conservation standard applicable 

to such covered products on the day 

before such date shall be deemed to 

comply with the amended energy 

conservation standard. 

§ 430.32 [Amended] 

5. Section 430.32. Energy conservation 

standards and effective dates. is 

amended by revising paragraph (d), and 

by revising the effective date of entry 

"2." in paragraph (e) to read "00/01/90." 

The revised paragraph (d) reads as set 

forth below: 

(d) Water heaters. 

The energy factor of water heaters 

shall not be less than the following 

products mamifactured on or after the 

indicated dates: 

Product class 

1. Gas Water 

Heater. 

2. Oil Water 

Heater. 

3. EIectnc Water 

Heater. 

I Energy faClor. as ; Energy factor. as i of Jan. 1. 1990 I of Apnl 15. 1991 

: 0.62-(.0019x 

Rated Storage 

Volume In 

gallons). 

0.59-(.0019" 

Rated Storage 

Volume In 

I gallons). 

10.95-(.00132x I Rated Storage 

I 

Volume In 

gallonS). 

0.62-(.0019x 

Rated Storage 

Volume In 

gallons). 

0.59-(.0019" 

Rated Storage 

Volume In 

gallons). 

10.93-(.00132" i Rated Volume 

I S.orage In 

i gallons); 

Note; Rated Storage Volume = .he water storage capacity 

of a water heater. ,n gallons. as Sl)8Clfoed by the manu'a! .Jrer. 

[FR Doc. 00-24134 Filed 1~16-90: 8:45 am) 

81WNQ CODE 14~'-1I 
-. CQ

i~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

i~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

EE-RM-94-230 COMMENT 49M