# - -**~**



# - - 

# - 

# -

w 

# w-

- 

# -- -
- 

# -- - ::.. =s**~** .__..:==;



# -



# --- -===== ==-. - 

# =**~**



# - -


# - -

- 

# - Tuesday June 12, 1990



# Part Ill


# Department of Energy

Office of Conservation and Renewable Energy

10 CFR Part 435 Energy Conservation Voluntary Performance Standards for New Commercial and Multi-Family High Rise Residential Buildings; Mandatory for New Federal Buildings; Final Rule, Response to Comments and Announcement of Appropriate Standby Loss Criteria

### 23842 Federal Register / Vol. 55, No. 113 / Tuesday, June 12, 1990 / Rules and Regulations

DEPARTMENT OF ENERGY

Office of Conservation and Renewable Energy

10 CFR Part 435
[Docket No. CAS-RM-79-112-C]
Energy Conservation Voluntary Performance Standards for New Commercial and Multi-Family High Rise Residential Buildings; Mandatory for New Federal Buildings

AGENCY: 

### U.S. Department ofEnergy.

ACTION: 

### Final rule and response to comments and announcement of appropriate standby loss criteria.

SUMMARY: 

### Pursuant to the October 6, 

### 1989, Memorandum and Order ofthe United States District Court for the District ofColumbia in Civil Action No. 89-1315, 

### GasApplianceManufacturers Association, Inc., etal., v. 

### Secretaryof Energy, the Department ofEnergy (DOE) hereby complies with the Memorandum and Orderbypublishing a Response to Comments andAnnouncement of Appropriate StandbyLoss Criteria (Response and Announcement). The Court remanded 10 CFR 435.109, section 9.3.2 and portions ofTable 9.3-1 dealing with "Minimum Performance (Loss)" for electric, gas and oil storage water heaters pending reconsideration ofthose provisions on remand in a manner consistent with the Court's opinion. See Court's Memorandum and Order, dated October 6, 1989. In that regard, the Court directed as follows: (1) That DOE provide a statement ofreasons for adoption ofstandby loss criteria, with attention to the relevant statutory requirements, including those dealing l111ith practicability, cost-benefit analysis, and impact on affected groups; (2) thatDOE place in the public rulemaking record all the materials on which it

### nowrelies in determining the storage waterheater criteria it 

### adopts

on remand; (3) that DOE publish its
statement ofreasons for adoption of standby loss criteria in the Federal Register; (4) that DOE make the materials upon which it

### relies available; (5) that DOE invite all interested participants to comment on the materials; (6) that plaintiffs and other interested persons file their response or responses with DOE; and (7) that DOE publish in the Federal Register a statement responding to plaintiffs' critique and any others, again with reference to the statutory requirements and announcing appropriate standby loss criteria.

Pursuant to the Court's October 6, 1989, Memorandum and Order, DOE has been enjoined from taking any action to enforce the requirements ofsection 9.3.2 and the relevant portion ofTable 9.3-1 pending completion ofthe remand procedures described above. With today's publication ofthis Response and Announcement, that remand process is completed. In the following sections of this Response and Announcement, DOE reviews the circumstances surrounding the remand process, discusses the comments it 

### received from interested persons during the process and the results ofadditional tests that it caused
to be conducted, and announces the standby loss criteria for electric, gas, and oil storage waterheaters that it is hereby adopting. DOE has modified tl1e criterion for electric storage water heaters andredefined instantaneous
water heaters. The criteria for gas and oil waterheaters have notbeen changed. DOE adopts these conclusions in a revised Table 9.3-1 in section V.

EFFECTIVE DATE: 

### The effective date for standby loss criteria for storage water heaters as presented in § 

### 435.109, Table 9.3-1, in section V ofthis Response and Announcement is June 12, 1990.

ADDRESSES: 

### Copies ofDOE's analysis and test data may be viewed and/or obtained from the DOE Freedom of Information Reading Room, room lE190, 1000 Independence Avenue, SW., Washington, DC 20585, (202) 586-6020, 9 a.m.-4 p.m., Monday-Friday, except holidays.

FOR FURTHER INFORMATION CONTACT: 

### JeanJ. Boulin, Office ofCodes and

Standards, CE-43, U.S. Department of Energy, room 5E-080, 1000 Independence Avenue, SW

.. Washington, DC 20585, (202) 586-9444. Lawrence V. Robertson, Jr., Esq

.. Office

ofGeneral Counsel, GC-12, U.S. Department ofEnergy, room 6A-141, 1000 Independence Avenue, SW

.. Washington, DC 20585, (202) 586-9507.

SUPPLEMENTARY INFORMATION:


### I. Historical Background


### A. Events Prior to October8, 1989



### This portion ofthe historical 1 

### background ofthe standards is presented at 54 FR 49724-49726, November 30, 1989.



### B. Events From October6, 1989- 

### November30, 1989



### These events are described at 54 FR 49726, 

### B. Events Subsequent to October 6, 1989.


### C. Events SinceNovember30, 1989



### In compliance with the October

### 6. 1989, Memorandum and Order ofthe Court, DOE has completed the following actions to date:

1. Published, 

### on November 30, 1989, 

### a Preliminary Statement ofReasons for Adoption ofStandby Loss Criteria (Preliminary Statement), with attention to the relevant statutory requirements, including those dealing with practicability, cost-benefit analysis, and impact on affected groups. (See 54 FR 49724).

2. 

### Placed in the public rulemaking record, on November 30, 1989, all 

### ofthe materials on which it

### relied in

- determining the storage waterheater criteria it

### proposed to adopt on remand.

The Preliminary Statement contained editorial errors. These errors were corrected at 54 FR 

### 50341, December 6, 

### 1989.

Subsequently. on February 2, 1990, DOE published a notice ofChanges in Dates for Comment. (See 54 FR 3714). Notice was given that, on motion by plaintiffs. the October 6, 1989, Court Order was amended to extend the time allowed to comment on DOE's Preliminary Statement and, correspondingly, for DOE to respond 

### to comments so received and announce appropriate standby loss criteria. The time for comment by the plaintiff and otherinterested persons was extended from January 15, to February 28, 1990; and the time allowed for the DOE's response from February 15, to May 15, 1990.

A Notice ofSupplement to Public Record was published by DOE to advise ofthe availability ofa "research grade" compiled computer code on diskette together with instructions explaining its

use by the Department in determining the gas, electric and oil water heater examples set forth in the Preliminary Statement. (See 54 FR 3714, February

## z. 1990). The source code compiled on diskette is that which is listed in 

### TechnicalSupportDoc11mentfor PreliminaryStatement of Reasonsfor Adoption of StandbyLoss Criteria, November 1989, U.S. Department of Energy, Washington, D.C

.. Table A-1. This was necessary because DOE, in response to a December 21, 1989, data request from GAMA, provided a copy of this information. In addition, DOE sent a copy ofthis information to all those who had requested or been sent copies ofthe November, 1989 Technical Support Document.
Il. Applicable Statutory and Judidal Criteria

Congress mandated, in section 501(b)(1) ofthe Department ofEnergy Organization Act, 42 U,S.C. 7191(b)(1), that the Secretary ofEnergy, in

### Federal Register 

## I Vol. 55, No. 113 

## I Tuesday, June 12, 1990 

## I Rules and Regulations

promulgating energy standards. must include "a statement ofthe research. analysis, and other available information in support of. the need for. and the probable effect of, any such proposed rule, regulation or order." In addition, section 501(d), 42 U.S.C. 7191(d) provides that after the notice and comment period, the Secretary may promulgate a rule 

### ifthe rule is accompanied by "an explanation responding to !he major comments. criticisms, and alterntives offered 

### during the comment period." Section 310 ofthe Energy Conservation Standards for New Buildings Act. 42 U.S.C. 6839. specificaily provides that such standards must be "adequately 11nalyzed in terms ofenergy efficiency.

. economic cost and benefit. and impact on affected groups. in addition, section 302 ofthe Energy Conservation Standards for New Buildings Act. 42 U.S.C. 6831(b)(2). requires DOE "ter achieve the maximum practicable improvements in energy efficiency and increases in the use 

### ofnon-depletable

sources ofenergy." 

### In that regard. 

### the October 6, 1989. Memorandum of the 

### Court concludes 

### that the word 'practicable' in section 302(b](2J 'rninforces the requirement of section 310 that DOE take into account cos!· 

### benefit and constituency concerns and 

### not simply sacrifice all 

### other concerns !o any reductions in energy use." Further standards-setting activities "shall be designed lo assure that such standards

are adequately analyzed in terms of energy efficiency. stimulation of use of rion-deple!able sources ofenergy institutional resources, habitability, economic cost and benefit. and impact upon affected groups "

Finally the Court's Memorandum further states that "increased energy efficiency must be weighed againsi potential increases in overall dollar
costs arising from new standards under

some articulated formula."


## m. Description of Storage Water Heater Standby Loss Criteria in Question

The Storage WaterHeater Standby Loss Criteria in question are part of Section 435.109 

### ofthe interim standards. entitled "Service WaterHeatLTJ.g Systems," published at 54 Federal Register 4889 (January 30, 1989). This section identifies the scope, design principles, minimum requirements, and a prescriptive compliance method for service water heating systems and equipment.

All water heaters and hot water storage tanks are addressed in Table 9.3-1. This includes electric, gas, and oil storage water heaters. unfired storage tanks. gas and distillate oil instantaneous water heaters. and swimming pool water heaters. There is

one exception to the standby loss criteria; storage waterheaters and hot
water storage tanks having more than 500 gallons ofstorage capacity need not meet the standby loss requirements of Table 9.3-1 

### if (1) the tank surface area is thermally insulated to R-12.5 and (2) a slanding pilot light is notused.

The standby loss criteria for electric, gas, and oil storage water heaters are highlighted in the right hand column of Table 9.3-1. Although the word "standby" could intuitively infer only that period oftime when the storage waterheater is not used, e.g., overnight, the criteria address the constant loss of heat energy experienced by a storage waterheater while holding heated water not immediately being drawn for use in

a building. A "storage water heater" is a waterheater that has an input rating equal to or less than 4000 Btu/hrper gallon and 

### a storage capacity ofmore than 10gallons.

The covered waterheaters include the following: electric storage 

### water heaters with 

### a storage capacity 

### ofmore than 120 gallons or an input rating ofmore than 12 kW; gas storage water heaters with a capacity ofmore than 100 gallons or an input rating ofmore than 75,000 Btu/h; and oil storage water heaters ofmore than 50 gallons or an input rating of

more tI:ian 105,000 Btu/h. The covered electric storage waterheaters are required to have a standby heat loss of less than 1.9 W/ft 2 • The covered gas and oil storage waterheaters are required to have 

### a standby heat loss 

### of less than 1.3 

## + 38/Vpercent per hour. Standby loss is based on nominal temperature difference of80°F, or the change in water temperature in percenl per hour based on a nominal temperature of90°F. Table 9.3-1 is shown below.

The test procedures that are to be used for certifying compliance with the standby loss criteria are described and explained in the Preliminary Statement at 54 FR 49730.

l!:llWNG CODE MS0-01-M

### 23844 

### Federal Register/ Vol. 55, No. 113 /Tuesday, June 12, 1990 /Rules and Regulations

Table 9.3-1 (January 30, 1989) Standard Rating Conditions & Minimum Performance of Water Heating Equipment

Type Fuel

Storage Electric

1 Water 

### IHeaters

Gas

Oil



# I I Storage! Input Rating**Applica~le** Test Procedure**Minimu.~** Performance Capacity

# I

(Gal)

DOE Rating

920 .:::_12 kW DOE Test Procedures, 1985 EF Code of Federal Regulations Title 10, Part 430 .::o.95-0.00132V

>120 {or) >12kW**~...** 000 

### ·.,- .:::_100 Btti/h ANSI C72.l

- 1972

DOE Test Procedures, 1985 Code of Federal Regulations Title lQ, Part 430

>100 (or) >75,000 ANSI Z21.10.3-1984 Btu/h Gas Water Heaters w/Addenda Z21.l0.3a-1985

.::_so .:::_75,000 Btu/h

.::_105,000

Btu/h DOE Test Procedures, 1985 Code of Federal Regulations Title 10, Part 430 EF

.::_0.62-0.0019V

EF

z.0.59-0.0019\f

>0.59-0.0019V Eff. Loss

SL

<1.9 W/ft2

SL

<l.3+

38/V



## I 

# I

>105,000 Btu/h E . c SL

<1.3+ 

# LJ

>50 

# (ol)

- 03\: 30/V**·.~~~~**

# I

9 CE690 Il.Cl.N

### Federal Register 

## I Vol. 55, No. 113 

## I Tuesday, June 12, 1990 / Rules and Regulations

Table 9.3-l (January 30, 1989) Standard Rating Conditions & Minimum Performance of Water Heating Equipment (Cont.)

Type Applicable Test Procedure Minimum Performance Input Class Fuel Capacity Rating

Unfired 1 All All Storage Volume In[>uts

Instantaneous Gas



# - All ANSI Z21.10.3-1984 Inputs

Distill All

011



## - Inputs

Pool Gas/ All AMS! Z21.56-1986 Heaters Oil



## - Inputs

Notes for Table 9.3-1: Terms Defined: l. EF = Energy factor, overall heater efficiency by DOE Test Procedure Et Thermal efficiency with 70°F, •T 

# - HL



# - <6.5 Btu/ll"ft2

Et 

## -

80\ 

# -

Ee 

# -

83\



# -

Et 

# -

78\c



## -

E0 

### = Combustion ef!icienc2, 100 percent

- flue loss when smoke a 0 (trace is permitted) SL 

## =Standby loss in W/ft based on 80°F, •T, or in percent per hour based on nominal 9o•F, AT HL = Heat loss of tank surface area V a Storage volume in gallons

Insert**IHustralio~s)** 737A-738 BILLING CODE 6450--0f-C 

### 10 CE698 Il.CLN



### next page, page 12 23845

### 23846 

### Federal Register / Vol. 55, 

### No. 113 / Tuesday, June 12, 1990 / Rules and Regulations

IV. Summary ofPublic Comment Received by February 28, 1990, on 

### the November 30, 1989, Preliminary Statement 

### ofReasons and DOE Responses 

### A.Summary

At the close ofthe comment period on February 28, 1990, 

### DOE had received responses from nine individuals, firms, and organizations. A number ofthose cofil111ents v;ere duplicative in nature. Tl1e comments dealt primarily with specific sections ofthe Preliminary Statement, including those dealing with DOE's assumptions in modeling standby less in gas and electric water heaters, the methods used to compute practicability and cost-benefit, and the impact on affected groups. There were also several general comments. It 

### should I:,,; 

### noted that reference is made in many ofthe comments to "DOE's proposed standards." The Energy Conservation Standards for New Commercial aad Multi-Family High Rise Buildings that DOE promulgated on January 30, 1989 (54 

### FR 4538), are not proposed standards. The standards became mandatory for aH Federal construction agencies onJuly 31, 1.989. After that clate, all new Federal buildings fitting tl::e category must be designed to meet

or exceed the standards. This, ofcourse, does not include portions ofthe standby loss criteria as specified in the October 6, 1989, Court Order.

The nine parties commenting included

one trade association (GAMA), two from one professional society (American Society ofHeating, Refrigerating, and Air-Conditioning Engineers, Inc. [ASHRAE]), three water heater manufacturers (Rheem Corporation, State Industries, Inc., and BradfordWhite Corporation}, a State energy office (California Energy Commission), a public interest group (National Resources Defense Council), and one individual (Lawrence G. Spielvogel of Lawrence G. Spielvogel, Inc.). The cc1mments addressed numerous issues; therefore, DOE has divided them into 86 individual comments. Each comment is addressed in this Response and Announcement, and a response is provided for each. The comments are grouped by issue. Duplicate and similar
comments are grouped and responded to

as a single comment.

The covered waterheaters addressed by this Response and Announcement

are defined in the DOE standards by fuel type, storage capacity, and input rating rather than byoccupancy served (residential or commercial). For example, some small storage capacity, low input storage water heaters are quite appropriate for use in some commercial buildings. However, to facilitate discussion ofcomments and DOE's responses, the term commercial, when used in regard to storage water heaters, hereafterrefers to the storage waterheaters covered by the standby Joss criteria in question defined in Section III.

The majority ofthe comments disputed the standby loss criteria, although a few supported the DOE criteria. One comment suggested a more stringent level for commercial electric storage waterheaters.

In developing the Preliminary Statement, as well as in responding to previous requests for information from the waterheater industry, DOE has provided detailed documentation in support ofits analysis. In responding to comments, DOE again is providing full documentation. This includes further computer analyses and tests 0'1 

### selected commercial electric and gas water

. heaters. DOE had anticipated a similar level of supporting documentation would be provided in the comments submitted by the interested trade association and waterheater manufacturers. However, this was not the case. Rather, in a number of instances these persons advanced arguments and asserted conclusions that

were not substantiated by accompanying data or documentation.

A Congressional mandate requires DOE to establish standards that achieve the maximum practicable levels of energy conservation, and DOE intends
to establish standards based on the data that is available, and has been made available to it. 

### In the case ofwater beaters, DOE has based its decisions on information derived from its OVii'11 

### research, the standards development process ofthe Standing Standards Committee-90R, ofASHRAE, and information provided by the industry. Some industry information indicates that the progression ofthe waterheater standbyloss criteria, from established standards and practice, through the criteria establish 

### by DOE, can be met

### by the industry through normal product improvement. DOE's analysis indicates likewise.



### B. General Comments

1. DOE received several general
comments concerning the practicability ofthe standby loss criteria for natural gas and electric waterheaters.,No specific comments were received regarding oil waterheaters, although

one comment on gas water heaters also alluded to oil water heaters. Three who commented strongly endorsed the DOE standby loss criteria. Five others contended that the DOE waterheater standby loss criteria for gas and electric water heaters are too stringent, and that DOE's method of analyzing potential energy savings and cost-benefit are flawed.

Thomas P. Wutka, CIGNA Corporation and Chairman ofthe ASHRAE Standing Standards Project Committee-90R, stated that the evidence DOE provides in its Preliminary Statement, "clearly demonstrates the cost-effective feasibility ofthe standby loss requirements for storage waterheaters." The ASHRAE 90R Committee also requested that DOE not loosen the requirements simply because other groups assert that the requirements are unreasonable. Mr. Wutka asserted farther that those groups seeking an injunction on the waterheater standby loss criteria have not offered any convincing evidence that the criteria should be amended. Mr. Wutka and Dr. David Goldstein ofthe Natural Resources Defense Council (NRDC), and

a member ofthe ASHRAE 90R Committee provided a letterfrom American Appliances, a water heater manufacturer, in support ofthe standby loss requirements, which stated "we feel that they are technically achievable by that time [1992] without unreasonable cost". While there was a follow-up letter qualifying these comments, DOE found it

### unpersuasive. Dr. Goldstein indicated in his comments that the standby loss levels were less stringent than they should be to meet the Congressional mandate ofachieving the maximum practicable improvements in energy efficiency.

Dr. Goldstein also said that the new analysis provided by DOE in the Preliminary Statement clearly demonstrated that a more stringent criterion for electric waterheatere-1.52 W

### /ft2

### -canbejustified. Dr. Goldstein provided procedural, technical, and other background information to substantiate these claims.

Finaily, Ms. Elena Schmid ofthe California Energy Commission (CEC} stated that the CEC found that a more stringent standby loss level could be used for gas waterheaters. However, Ms. Schmid said, at the current time, a

more stringent level has not been reviewed thoroughly enough to warrant that DOE assess more stringent criteria.

Contending that the DOE waterheater standby loss criteria for gas and electric waterheaters are too stringent, Mr. Denver Collins of State Industries, Inc.,

a water heater manufacturer, stated that DOE needs an education in commercial water heaters and**recommend~** 

### that DOE work in good faith with the water

### Federal Register / 

### Vol. 55, 

### No. 113 / 

### Tuesday, June 12, 1990 / 

### Rules and Regulations 23847

heater industry to arrive at reasonable, obtainable efficiency goals based on actual test data rather than on invalidated,_erroneous computer models.

DOEResponse:

### DOE agrees with the three who endorsed the DOE standby loss criterion for the gas waterheaters. DOE believes that the water heater standbyloss criterion for the gas water heaters are practicable. While DOE believes that there is some data to suggest that more stringent [gas] water heater standby loss criteria would be reasonable, it 

### agrees with the comment made by the CEC that a more stringent level has not been reviewed thoroughly enough to warrant that DOE set more stringent criteria at this time. DOE also believes that Federal construction agencies that specify storage water heaters in the design oftheir buildings will find waterheaters on the market to meet these criteria at life-cycle costeffective prices.

In response to several ofthe other commenters on the electric waterheater criterion, DOE has performed tests and done additional analysis that cause DOE to believe that slightly less stringent criterion for electric water heaters are warranted. A more detailed discussion is provided below.

DOE appreciates the receipt ofdiverse comments. It

### is through public comment that DOE hopes to improve its standardmaking process. However, it

### is important that those who do comment

on DOE standards substantiate their views and document orreference published material to support their statements. Statements ofopinion and substantive comments must be supported by essential documentation.

Finally, DOE has attempted to work with the industries affected by its standards. Every effort has been made for public review and comment, and through ASHRAE, DOE has worked with the most widely recognized ofall energy conservation standards development bodies. In that regard, DOE forcefully rejects the suggestion that it 

### has not been responsive to the concerns expressed by industry representatives.

2. 

### Mr. Paul G. Daugirda ofRheem Corporation and Mr. Eugene L. West of Bradford-White Corporation, both water heatermanufacturers, stated that none oftheir current electric or gas model commercial storage water heaters would meet the standby loss provisions ofthe proposed DOE standards. Mr. Daugirda said that DOE's inexperience in the design and construction ofwater heating equipment led to optimistic assumptions and unrealistic conclusions.

DOEResponse: 

### While it 

### is expected that some commercial storage water neaters will not meet the criteria set by DOE, DOE continues to believe that the criteria are fair and not onerous to ·waterheatermanufacturers. It

### is not

uncommon in any area oftechnology that some current models will notmeet the new criteria when more stringent standards are set. Ifthe standards are developed fairly and are not unduly burdensome, it

### is then up to the purveyor ofthat technology to make the decision whether to continue to market specific equipment. If

### the decision is made to market that equipment, then the necessary modifications will have to be undertaken.

DOE believes that its waterheater standby loss criteria, with some modification to the electric storage water heater criterion, are fair and not unduly burdensome. It

### further believes that many current water heaters can be easily and cost-effectively modified to meet the standards. DOE has produced substantial information to document its rationale, including information that is discussed laterin this Response and Announcement.

3. Rheem Corporation estimated its lost revenue, on an annual basis from Federal sales, to be approximately $800,000 if

### the standby loss criteria are not modified. Mr. Daugirda stated that if 

### various States, especially large market States like California and New York, adopt the Federal standards, the lost sales revenue could easily amount to several million dollars.

Mr. Daugirda also indicated that to stay in business in the Federal sector, the Rheem Corporation would have to re-tool its production facility to produce entirely new models. The company now has eight basic designs ofgas-fired water heaters in the 75,500 

### to 100,000 

### Btu/h input range, a category ofproduct that comprises 23 

### percent ofthe company's commercial waterheater business. Only one ofthese designs has

a flue damper. To modify these designs

as needed to comply with the DOE criteria would require the addition of a flue damper to all but one design, and increased insulation and enlargement of the casing for all eight designs. Mr. Daugirda claimed these to be radical changes that would increase manufacturing costs by approximately 50

### percent overmodels without flue dampers. He stated further that the total standby loss energy savings would not

come close to defraying the additional costs ofthe units.

DOEResponse:

### The company provided no basis for choosing not to build units that meet the standby loss criteria. Rather, it 

### acknowledges that it 

### currently produces a product line that

uses flue dampers, but provided no additional information as to how and why the production line wouldhave to be changed to accommodate the addition ofthe flue dampers and insulation to Rheern's other currently available water heaters. It 

### further stated that the addition ofa flue damper will increase manufacturing costs by 50 

### percent over models without flue dampers, but again, provided no explanation or supporting information.

Mr. Daugirda implies that the company would lose money by building units to the DOE standby loss criteria. However, this is not logical assuming that the standby loss criteria become mandatory in wide segments of the water heatermarket. The setting of standards automatically creates a market and market forces would set the unit price. If

### this were to happen, the question for manufacturers becomes whether they choose to reenter the market with a modified product which

can compete in that market. ASHRAE/ !ES Standard 90.1-1989 

### has been published with standby loss criteria similar to those in the DOE Interim Standards. A number of States and local governments have expressed interest in adopting the DOE or ASHRAE/IES standards. It 

### is DOE's beliefthat ifthe ASHRAE/IES Standard 90.1-1989 

### becomes the operable standard across the country, then a very large market will be created.

In the meantime, DOE has an obligation to set standards that must "achieve the maximum practicable improvements in energy efficiency." [Public Law 94-385] 

### Given that water heater units that meet the standards are currently available and that these units

come within the life-cycle cost guidelines (subpart A of 10 

### CFR part 436) 

### under which the Federal government operates, it 

### is DOE's responsibility to set standards that most benefit the Federal government.

4. Dr. Goldstein ofNRDC requested that DOE conduct further analysis of the standards on affected groups. Dr. Goldstein identified taxpayers as the primary group affected by the DOE standards since they are responsible for the energy bills ofbuildings covered by mandatory standards.

In addition, Dr. Goldstein stated that the general public is an interested party because the Federal standards, coupled with the similar ASHRAE standards, will influence or even determine the design ofmost commercial buildings in future years.

According to Dr. Goldstein, failure to promulgate energy savings requirements that are costceffective-that is, ones whose cost to society is less than the cost ofnew energy supply-raises utility

### Federal .Register 

## I Vol. 55, No. 113 

## I Tuesday, June 1.2, 11}90 

## l Rules and Regulations

billsfor everyone. Thisresultsinexcess and unnecessary consumptionoffossil fuels withadverse effects on the nation's energysecurity, airquality, and the global climate.He saidthe standards proposed byASHRAE are exceptionally cost-effective-the DOE Technical SupportDocument suggests paybackperiods ofless than three years. Forthis reason, he said, these otherparties would be adversely affected 

### ifDOEfails to adopt a standard
at least as strong as that adopted by ASHRAE.



### DOEResponse: Itis fully DOE's intention to adopt standards thatare practicable for both thegroups that must

abide bythe standards and those groups that would be affected, in the long term., should reasonable standards not be adopted. In order to reassess its position

on the standby loss criteria, DOE has performed further technical and costbenefit analyses based on the comments received. Based upon itsreview and analyses, DOEbelieves that the standards ithas promulgated, and those it will modify through this document, are practicable for groups administeringand complying with the standards and also fair to the general public.


### C. Comments on DOE'sBasic Assumptions inModeling Commercial Storage WaterHeaters

DOE received severalgeneral and specific comments regarding the assumptions usedinmodeling different capacity and fuel types (gas, oil, and electric) ofwaterheaters.The computer rnodelingwas done for severalpurposes. First, to establish a baseline for current capacity andfuel types ofwaterheaters. Second, to determine the modifications that would be needed, when necessary,
so these units could meet the DOE standards. Third, to evaluatethe energy savings potential oflowered standby loss levels. Lastly, to determine the costbenefit ofthe waterheaters atthe lowered standby loss levels.

It should be noted thatnot every waterheater currentlyavailable was modeled. Rather, the analysis was performed on a range ofgeneric water heaters ofdifferent sizes, shapes, and power.inputs. This approach was taken
to evaluate the effects ofspecific standby loss criteria and not as a way of evaluating currentmodels. To respond
to public comments, DOE did, followiI).g the public commentperiod, test two units-one gas-fired and another electric. These tests were performed to help verify assumptions made in modeling and to assess tests reported by the industry.

A thermal modeling approach was used to determine the standby water heater losses through the tankjacket. The thermal model usedin the analysis is a steady-statemodel basedon first principles ofthermodynamics. It uses universally accepted equations for

. calculating the heatflow from the heated water and acceptable values of thermal resistance for various materials in generic models. Due to the wide varietyofwaterheaters on the market, a generic model wasused tbatmadeno attempt to calculate subtle design differences betweenmodels and manufacturers. Rather the model took
account ofbroadlyrecognized characteristics ofstorage waterhealers that significantly affect standby losses.

Where the inputs to the model were known to varysignificantly, a range with high, medium, and lowinputs was tested in the model to establish the "sensitivity" to the variations. For example, when there were questions about the values assigned the emissivity ofthejacket, several runs ofthemodel

were madevarying the emissivity for each run and showing the sensitivity of the results for eachvariation.

Figures 1 and2 illustrate the heat losses accountedfor by the model. The model accounts for 100percent ofthe standby losses from thejacket. It did not originally account for the otherlosses due to fittings, controls, and flue in the

case ofgas units. DOE did, however, add losses to the model to account for these fitting losses. This information

was based on available data, which is summarized laterinthis document. The
waterheatertank was modeled as a right cylinder (having its axis perpendicularto the base) containing
water at a uniform temperature, surrounded by air, which is also at a uniform temperature. Water and air temperature were selected to correspond to those indicated in the appropriate testprocedure for the specific waterheater type.

### Federal 

### Register / Vol. 

### 55, No. 

### 113 /Tuesday, June 12, 1990 / Rules and Regulations 23849

JACKET TOP RELIEF FITTING

INLET 

### FITTING OUTLET FITTING

ELECTRIC

WATER HEATER JACKET SIDE

DRAIN FITTING
CONTROLS

JACKET BOTTOM 

# COMPONENTS OF HEAT LOSS

Figure 1

- 

### Heat Loss Components for Electric Water Heaters

Use ofthe steady-state thermal model allows calculation ofheat flow rates from the water in the tank to the ambient air with varying levels oftank · insulation. This approach permitted DOE to perform a sensitivity analysis to determine the level ofinsulation required to meet the standby loss criteria. The required insulation levels for different waterheater types and sizes are listed in the Preliminary Statement and the accompanying Technical Support Document.

As described above, the thermal modeling approach used by DOE is based on a steady-state analysis. The actual standby loss tests ofwater heaters conducted in accordance with the test procedures are dynamic tests covering a 48 

### hour period. Actual standby loss tests are required to be conduc"ted over an extended period of time due to the complexity ofmaking
accurate measurements ofheat loss on a steady-state basis. The test procedure

measures the energy inputrequired to maintain the water at the setpoint temperature, the input energy required
to maintain the setpoint temperature is exactly equal to the steady-state heat loss ofthe water heater.

### .23850 Federal Register 

# i Vol. 55, No. 113 ./·Tuesday, June 12, .1990 ./ Rules .and Regulations



### TOP

CLEANOUT 

### FLUE

GAS


### WATER 

### HEATER

BOTTOM 

### FITTINGS

JACKET



# COMPONENTS OF HEAT LOSS

Figure 2 - Heat Loss Components for Gas Water Heater

The steady-state modeling approach used byDOE did not attempt to model the standby loss test, but was instead designed to give ·results equivalent to the standby loss test. The reference to the test procedure used as the basis for the standbyloss calculation shown in the Preliminary Statement and the accompanying Technical Support Document is a reference to the specific standby loss equation used in the calculation.

1. 

### Faulty Modeling

DOE received several general
comments from Rheem Corporation, StateJndustries, Inc., Bradford-White Corporation, and GAMA asserting a lack ofknowledge by DOE regarding water heaters, and, therefore, questioning its expertise in compiling a rational computer model. Specifically, the comments addressed the precision with which DOE modeled specific types ofwaterheaters. For example,
comments from Rheem, Bradford-White, and GAMA related to size ofwater heaters modeled, suggesting that DOE reviewed too large a range ofwater heater sizes, and that the market was primarily within one size-100gallons and less.



### DOEResponse: DOE believes that the issues are whether .the computer model is reasonable for the entire range of water heaters covered by the standards, and whether the assumptions used are conservative enough to be inclusive of
most water heaters and to establish the practicability ofthe criteria. Most ofthe
comments were directed at a relatively small portion ofthe storage waterheater market.

However, to provide some finality to resolving the question ofmodel assumptions, DOE directed the National Institute ofStandards and Technology (NIST) to purchase two "off-the-shelf' storage waterheaters, one electric and

one gas, and test the units. The results of the tests were then compared with the results generated by DOE's computer model. After adjusting input assumptions for fitting and control losses for the electrical unit, close correlation was found between the results. Thus, the computer model showed itselfto be consiStent with the NIST test data. The geometry and size ofwater heater flues were also areas in which DOE received negative comment. It 

### was asserted thatDOE only modeled uni.ts with a single flue through the water heater tank. The three who commented

on this subject stated that most water heater designs include a multiple flue arrangement through the tank. The hot gases that pass through the flues are then collected at the top ofthe tank and released through a single flue hole. The
comment was made that the geometry and surface area for these waterheater types would have a significant effect on standby loss and that DOE had not· accounted for this type ofwater heater in its modeling. As stated previously, it



### was not DOE's intention to construct a model that handled specific water heaters, rather it 

### was constructed to provide conservative data for an entire range ofwaterheaters. In this instance, DOE allowed for a range ofpercent heat losses through the flue and picked what it 

### thought was the most appropriate value. However, it also found that the appropriate value may vary depending

on input firing rate.

### Federal Register 

## I Vol. 55, No. 113. 

## I Tuesday, Junel2, 1990 /,Rules and, Regulations 

### 23851

A sensitivity analysis was performed
to determine the effect on tank and jacket surface area as a result of considering multiple flues as opposed to

a single flue. For this analysis a 100- gallon gas water heater with the same dimensions as those shown in Table 1 of the Preliminary Statement v1ras analyzed. For each case analyzed the tank volume and tank height were assumed ta be constant. The unit was assumed to be insulated with 2 inches of insulating material in order to establish the jacket diameter. As additional flues

were added, the tank and jucket diameters were increased to

Table 1 accommodate the additional flue area while maintaining a constant water volume. Table 1 in this Response and Announcement indicates the differences between the different configurations is
not significant for the purpose of altering the method ofestablishing the slandbv loss criteria.

SENSITIVITY OF SURFACE AREA**CP.l'u~GES** TO VARIOUS FLUE CONFIGURATIONS

NUMBER

.OF
FLUES FLUE NET TANK JACKET TANK JACKET**TA.~K** JACKET CHANGE IN CHANGE IN TANK AREA JACKET AREA PIAl'1ETER AREA DIAMETER D!AMETER HEIGHT HEIGHT AREA 1'.F.EA

(in.) (sq. in.) (in.)· (in.) (in.) pn.) (sq. ft.)(sq. ft.) (\) (\)

1 6 443.01 23.75 27.75 55.70 57.70 31.94 39.13 

### o.oo -0.00
4 3 443.01. 23.75 27.75 55.70 57.70 31.94 39.13 0.00 0.00

6 3 457.15 2"4 .13 28.13 55,70 57.70 32.49 39.72 1.74 1.50

8 3 471. 29 24.50 28.50 55.70 57.70 33.04 40.30 3.45 2.99
10 3 485.43 24.86 28.86 55.70 57.70 33.58 40.87 5.15 4.45
12 3 499.56 25.22 29.22 55.70 57.70 34.12 41.44 6.82 S.90 14 3 513.70 25.57 29.57 55.70 57.70 34.65 42.00 8.48 7.33
16 3 527.84 25.92 29.92 55.70 57.70 35.17 42.55 10.12 e.74 18 3 541.97 26.27 30.27 55.70 57.70 35.69 43.10 11.74 10.14 20 3 556.11 26.61 30.61 55.70 57.70 36.20 43.64 13.34 11.52 22 3 570.25 26.95 30.95 55.70 57.70 36.70 44.18 14.93 12.69

NOTE: Analysis based on 100-gallon gas water heater described in Table l of the Preliminarj Statement

2. Specific Comments

a.

### jacketHeat Loss. Lawrence G. Spielvogel ofLawrence G. Spielvogel, Inc., stated that DOE's assumptions

were flawed because the model assumed that all standby heat loss from thejacket ofa water heaterrepresents

.wasted energy. Mr. Spielvogel stated that virtually all waterheaters are in heated space in buildings. Therefore, jacket heat loss provides useful heat to the space, reducing the amount ofheat thal is otherwise required. The space in which water heaters are located is virtually never air conditioned. Since there is no energy penalty for air conditioning, jacket losses are losses only during the months when there is no heating. Throughout the continental United States this period oftime typically ranges from several months to about six months per year. In addition, the ambient temperature is usually higher than 70° to 72° F during those months. This further reduces jacket heat loss. Therefore, according to Mr. Spielvogel, the benefit associated with reducing jacket loss is only a fraction of that set forth in the DOE analysis. Mr. Spielvogel did not provide data to support this argument.



### DOEResponse: No supporting data

was provided for the comment. DOE believes that most water heaters are located in mechanical rooms. Such spaces are generally vented to the outside and the heat is lost when vented. Waterheater standby loss is not calculated in the sizing ofheating of such spaces and reduction ofthis heat loss is not likely to have any benefits for down sizing ofequipment.

Waterheaters located in conditioned space, likely will be in core areas ofthe building, Such core areas of a building

are very often cooled year-round. In such conditions, the standby loss requires additional energy to cool the

excess heat.

In those cases ofwaterheaters located in heated spaces, DOE believes that many ofthese spaces are both heated or cooled, or adjacent to and influenced by spaces that are both heated and cooled. In such cases, DOE believes the benefit from heat loss in the heating season is lost to the cost of

. cooling and ventilation in the swing and cooling seasons. DOE believes that its assumptions are correct nationally. It should also be noted that Sections 11 and 12 ofthe standards make provision for taking advantage of otherwise unaccounted for benefits in the standards through a whole building energy analysis. Furthermore, the DOE standards do not

assure water heater placement regardless ofcurrent practice. DOE does
not believe it to be practical to make this a requirement. Therefore, units should be designed for use in nonconditioned areas.

GAMA also commented on jacket heat loss, contending that DOE changed its criteria by allowing for insulation to be placed, either internal or external of the waterheaterjacket. Furthermore, GAMA contended the test procedures used to evaluate the water heaters do
not make any accommodation for adding insulation on the outside ofthe
water heaterjacketprior to conducting the test. GAMA indicated that the ANSI/ASHRAE/IES Standard 90A-1980 standby loss requirements have always been applied to the water heater without external insulation. In using the test procedure and adhering to Standard 90,

### 23852 Federal Register / VoL 55, 

### No. 113 

## I Tuesday, June 12, 1990 / 

### Rules and Regulations

the only insulation considered is that which is placed between the tank and the waterheaterjacket at the time of producti-On. GAMA argued that no enforcement agency or any other standard-setting organization recognizes the option ofinsulating the outside as a
means ofestablishing compliance. It contended that 

### ifDOE truly intended that its standby loss criteria could be satisfied by insulating the outside ofthe
water heater, the dispute with DOE could be resolved very simply. DOE's standards could be revised to specify the standby loss requirements currently found inANSI/ASHRAE/IES Standard 90A-1980 andseparatelyrequire that all commercial storage waterheaters be wrapped with an external insulation blanket at the time ofinstallation. The R-value ofthe external insulation could be specified to provide the desired level ofstandby loss.

.

DOE

### Response: There is nothing in the test procedures that would prevent the testing ofa storage waterheater with additional insulation external to the

· metaljacket. From the standpoint of ·

testing waterheaters, it does not matter whether the insulation is internal to the
waterheaterjacket orexternal. as DOE has found in the 

### tests conducted at. NIST. Therefore DOEconducted its analysis to include 

### allpossibilities.

DOE believes that external insulation is not a preferred solution 

### ifthe insulation 

### is ofthe type thatcan be easily damaged in operation. For example; low quality insulation v.Taps

can become detachedeasily and.can disintegrate with time; extern.al insulation can be torn or.otherwise disabledunless covered by a stiff ;;hell; and routine maintenance 

### to external insulation is subject to the rigors of maintenance, moistur,e, and animal destruction. DOE does not intend to engineer a specific solution for external insulation, but is aware offoam insulations that might be used externally.

b. 

### Set Water Temperatures. Mr. Spielvogel andGAMA commented on the assumption used for water temperature. Mr. Spielvogel stated that DOE is incorrect in its p.ssumption that hot water is stored at 140° F to 160° F. He stated that heater temperatures typlcaliy are set in the range of 110° F to 120° F. Both comments indicated that

even in the DOE standards-Section 

### 9.3.4-DOE suggests 

### waterheater

no than 120° F, with**~~·~n.ovu** ofbooster heaters for any

DOE received no supporting with which
to scrutinize the assertion. it appearn Iha! the commenteri:; have**misinterprete~d** the standards. Section 9.3.4.1.1 ofthe DOE Interim Standards suggests that w·ater temperatures need
not behigher than 120 °F exceptfor certain uses. This is a suggestion only,

as nowhere in the standards are water temperature levels set. At outlets for a particularuse over 120 °F, DOE requires separate remote heaters orbooster heaters. For example, a restaurant in what otherwise is an office building would require higher water

. temperatures for dishwashingand sterilization.

In its analysis DOE uses the 140 °F to 169 °F to reflect the tank temperatures from the only data available to DOE at the time, a End-Use Load and Consumer AssessmentProgram (ELCAP) study sponsored by the Bonneville Power Administration. In this study commercialbuilding tanktemperatures

were.not studied. Data from residential waferheater tank temperature (409 ·temperatures taken) shows the average temperature to be 137 °F, with 

### a range of 104 °F to 195 °F. Multiples oftank temperatures clustered at standard 120 °F, 130 °F, and 140 °F values. The DOE assumption of140 °F was based on what

was likely to occur.

c. 

### 24-HourPerDay Use. Mr. Spielvogel and GAMA indicated that it

was presumed that the covered water heaters were used 24-hours per day. Mr. Spielvogelindicated that increasingly it is usual practice to tum offall types of waterheaters when non-residential buildings are unoccupied. This is accomplished by seven-day time clocks

or with energy management systems. Therefore, according to him, in a typical commercial building. the waterheater is likely to be offmore than halfthe hours in a year. GAMA states that a good average usage is 14hours per day.

DOE

### Response. The intent ofthe standby loss criteria is to reduce heat losses. In general these losses can be reduced through the addition of insulation. Additional insulation benefits the efficiency ofthe water heater whether itis in the standby mode

or in an operational mode.

Both the ANSI and DOE

### test procedures dictate that the units be tested in the standby mode. The test procedures are designed to isolate the losses arising from the standby loss of the unit. In actual operation, the unit will be in for part ofthe time, and will be and circulating water for the other part. In either case, the additional insulation required to meel the loss criteria will serve to rf,duce losses of

With respect to the use oftime and energy management systerns, DOE d,id not receive any data**or""''"''~"** information to substantiate from the comment. DOE does nothave any information that indicates that either time clocks orenergy management systems predominate in turning 

### off commercial waterheaters during times ofnon-use. The data it does have from the ELCAP study sponsored by the Bonneville PowerAdministration indicates that a very small percentage of commercial waterheaters are controlled.

d. 

### Sizes ofUnits Modeled. Several
comments stated that DOE's choice of volumetric capacities is not representative ofthe marketplace. The
comments indicated that the majority 

### of commercial gas storage waterheater models have storage volumes in the range of50 to ioO gallons, with the two most common sizes being 75 to 100 gallons. Further, the comments indicated that the formulas and criterion employed to model commercial gas-fired
waterheaters were developed only to

cover 

### a narrow range ofresidential size
waterheaters with specific physical characteristics.

Rheem Corporation commented that 99. percent ofwaterheaters sold have volumetric capacities of 100 gallons or less. Mr. Daugirda also stated that modeling units ofgreatercapacities. when the formula used to set the standby levels is tilted in favor oflarger units, gives misleading results,

Bradford-White Corporation indicated that 80 percent ofits gas-fired water heaters sold were in the 75 to 100 gallon size (100 percent ofthe electric water heaters were the 50to120gallon range). Mr. West also indicated that the larger than 100 gallon for gas, and 120 gallon for electric, water heaters have sales prices ofsix to ten times the price of typical, smaller-size models.

Mr'. West pointed out that the electric waterheaters DOE examined-50, 120, and 170 gallons-do not accurately represent common models. The predominant volume sizes of commercial electric storage water heaters range from 50 gallons to 120 gallons. Annual shipments ofmodels within this volume range account for

over 90 percent ofthe total commercial electric storage waterheater shipments. The typical line consists ofa 50- or 52- size, an 80-, 82- or 85-gallon size. and a 120-gallon size. The DOE anaiysis should have included a modal with a volume of80, 82 or 85 gallons.

GM!A indicated that the sizes modeled by DOE to the sizes for only one company (A.O. and**tha~** the company offered the greatest variety oflarger volume models. These models, however, are

### Federal Register /Vol. 

### 55, No. 113 

## l Tuesday; June 12, 1990 

### /rRules and Regulations 23853

equipped with powergas burners and

are not representative oftypical

. commercial gas storage waterheaters.



### DOEResponse:The predominant size

· capacity ofcommercial gas an.d electi::ic

storage wat(;lr heaters sold in the United States may well be in the .50 

### to 120 · 

### gallon range. OOEdoes not have data confirming thatinformation despite severalrequests to the irn;lmitry that such information 

### be furnished. It 

### is also

. not known 

### ifthe manufacturers!

. . . assertion includes both comme.rcial and residential waterheaters.

However, DOE has used an analysis that is 

### not dependent on mix ofmarket sales. DOE 

### has analyzed a wide-range 

### ofsizes fr1a t 

### are covered by the criteria. It

### does not matter that certain sizes predominate the market. DOE 

### has the obligation of settinglevels for 

### all storage waterheaters that are within the scope ofthe standards.Hs study isvalid if it 

### adequately covers therange ofwater. heaters covered by the criteria. Thus, the studyneed not be a weighted average.study ofthe units sold.,The. study addressed the issue by looking at

a range ofsizes andperforming sensitivity analyses to identify parameters that might be sensitive to, change. The study**~learly** 

### shows that the range ofunits addressed was quite adequate to address the range ofunits about which Mr. West expresses
concern.

With respect to the comment concerning types ofgas-fired water heaters modeled, while it is true that the units were modeled after the large powergas burnerheater line ofone ·manufacturer, the models in the analysis did not attempt to utilize a powerburner design. The models were chosen simply
to provide representative tank dimensions oflarge gas-fired storage water heaters: Because the analysis was looking specifically atjacket losses, the

concern about the powered burners and therefore, the cost ofthese units, is not warranted.



### D. Comments on Eiectric St.orage Water Heaters

1. 

### Specific Comments

The majority ofthe comments pertained to gas storage waterheaters. However, GAMA and each ofthe manufacturers that commented produce both gas and electric water heaters and have provided comments on each type.



### a. WaterHeater CharacteristicsElectric. DOE received comments from GAMA and Rheem Corporation. They indicated that DOE was incorrect in assuming that commercial electric storage heaters are constructed the

same as residential electric models. They stated that there are two major differences-:thelarger surface. area cf the.partofthejacket that covers the waterheater's controls and the. area where the heating eleml;lnts, thermostatic controls, and electric circuits are located. The effects of.these. two differences are: (1) 

### the exterior surface ar.ea estimates ofthe DOE's analysis are too small; and (2) 

### the tank surface area aroundthe heating elements, controls, and circuits cannot be insulated with 

### foam. Thus, the tank surface area has higher standby losses than otherparts ofthe tank because it

### is not as well insulated as the rest ofthe storage tank and it 

### also provides several thermal leaks where there are penetrations ofthe insulaUon.

Mr. Daugirda ofRheem Corporation stated that the DOE analysis is flawed by the use ofa 0.5 

### emissivity and a**76.6~F** 

### temperature difference (150°F 

### water temperature and 71.4°F room temperature) while the basis ofthe sta11dby loss is an 80°F difference. Mr. Daugirda indicated that these flaws

caus.e a three percent discrepancy due to «?missivity .and a 4.3 

### percent discrepancy due to temperature differences. This accounts for a cumulative 7.3 percent difference from the expected. These latter assumptions

are made based on the outlet andrelief valve fittings typically being atthe top ofthe tank (highest temperature) and inlet and drain fittings typically being at the bottom ofthe tank (lowest temperature).



### DOEResponse: The commenters are incorrect in their statement that DOE assumed that commercial electric storage waterheaters are constructed in the same manner as residential electric models. Data from commercial water heater manufacturers and vendors were used to establish modeling parameters foflhe analysis. DOE is quite aware of the extensions ofsurface area that occur
on commercial units, such as extensions covering the heating elements, controls, and electric circuits. According to manufacturers literature, these extensions vary depending on the unit selected. Therefore, it 

### would be difficult, time-consuming, and non-productive to model every model and type ofunit.

DOE used a modeling approach that considered the water heater as a right cylinder. The jacket surface area used in the calculations was based on the area of a cylinder without regard to any extensions ofthat area required to accommodate the electrical components. DOE believes that this method represents the most consistent method ofdealing with jacket surface area. Consideration ofthe additional area covering the electrical components would lead to a lpwering ofthe calculated standby

### loss for an individual unit.However. in its. model, DOE 

### has accounted for the standby losses attributed to fitting, controls, and other externalities.

Various published studies

## on water heaters were reviewed to approximate the losses attributable to fittings :md controls. [Harris, 1984; 

### Hoskins, 1977; 

### Mutch, 1974; 

### Palla, 1979] 

### The information available from these reports

was based on analysis and testing of residential water heaters. 

### No data on commercial fittings and controls was uncovered and none ofthe commenters provided such data. Appropriate adjustments were made to adapt the 

### information for commercial storage waterheaters. DOE concluded from this analysis that the heat loss from:

Pressure 

### ReliefValve Fitting=14 Btu/h@ 72"F &T Drain Valve Fjtting=7 Btu/h@72°F AT



### To develop figures for the inlet and outlet waterline fittings, the assumption

was made that the losses were proportional to the diameter ofthe fittings, and that the outlet (hot) fitting would be equivalent to the pressure reliefvalve fitting and the inlet (cold) fHting would be equivalent to the drain valve fitting. Under these assumptions, and considering the relative diameters oftypical fittings the following loss figures were estimated:

Inlet Fitting=14 Btu/h@72°F .t.T (at assumed twice drain valve fitting diameter) Outlet Fitting=28 Btu/h@72°F .AT (at assumed twice pressure reliefvalve fitting diameter)



### None ofthe published reports provided data on the losses from the controls for the electric water heaters. The controls are considered to include the thermostat and electric heating elements along with the associated wiring. The NIST test data was used to develop a loss figure for the controls.

The NIST tests on the electric water heatermodified to eliminate thermal shorts yielded an average heat loss rate of294.2 

### Btu/h. When the NIST unit was further modified bywrapping the unit in

an R-11 insulation blanket and inserting

an R-11 

### batt over the electrical components the average heat loss rate

was 237.9 

### Btuh. The difference between the two loss rates was presumably due
to the jacket loss reduction and the reduction in loss from the electrical controls. Use ofthe model would allow the determination of the jacket bss reduction, leaving the remaining loss as attributable to the controls.Using the NIST test data: for the modified unit and the.modified unit plus

· aninsulationjacket: ·

NISTMODl(modified unit) average heat

. loss=Z94.2 Btu/h

. · NISTh10D2 (modified unit plus**R~:l1**

· Batt)=237.9 Btu/h · Difference=56.3 Btu/h

Using the model t<;1 predict the difference injacketheatlosses:

MOD1 (model with the same insulation NIST unil)=193.4Btu/h MOD2 (modelwith R-11 insulation blanket added)=162.3 Btu/h Difference=31.1 Btu/h.

The difference between the 

### two. NIST
tests does notreflect any difference in the losses from the fittings since no · changes were made in this area. Thus, the difference in the NIST tests results from the difference in thejacketkisses plus the difference in the controls losses. Since L'ie jacket loss difference is presumably accounted for by the model, fae remaining difference should be the losses associated**w~th** the controls.
Difference in NIST tests (294.2-237.9)=56.3 Btu/h .· . Difference in model (193.4:-162.3)=.31.1 Btu/ h

. Amount attributable to controls lo8ses=25.2 Btu/h. Summarizing the estimated losses for the non-jacket areas (fittings and controls) after correction to the test conditions of79.95°F 

### .6.:

Inlet Fitting {14 Btu/h @72 •p ATJ=15.'5 Btu/ h

. . Outlet Fitting (28 Btu/h@ 72 °F Ji,.T}=31.1 Btu/h Pressure ReliefValve {14 Btu/h@72 •p AT)=15.5 Btu/h Drain Fitting (7Btu/h@72 °F AT)=7.8 Btu/h Controls=25.2 Btu/h Total Lo&s.=1)5.1 Btu/h

To correlate the results ofthe model with the results ofthe tests, these fittirigs and control losses are substituted into an equation that describes the heat loss:

Heat Loss=JacketLoss 

### + Fittings Loss 

### + Controls Loss

From the model for the modification 

### #1 condition, the heat loss is 193.4 Btu/ h. The corresponding heat loss from the NIST test data is 294.2 Btu/h. The difference between the two figures is 100.8Btu/h. Comparing this number to the total lOss 

### from fittings and controls indicates that the model and the test results show heat loss within 5.7 Btu/h ofeach other, when reasonable assumptionsfor the fittings and controls

are made. The testproced\J.re DOE used for electric waterheaters (ANSI Standard C72:1'."""1972) calls for .<J. test room temperature 

### of73.4 °F ± 5 °F.**±3.~** °F and a top-of-tank water temperature of 150 °F±5 °F. This information is provided in the Prelirriin<J.ry Statement of Reasons. The equationused in the DOE Interim'Standards to calculate standby losses includes a term to correct the · actual test condition to an 80°F

. temperature rise condition. In calculating the standby loss rate for a given electriC waterheater model, as subjected to theANSI Standard G72.1- 1972 test conditions, the computermodel used the specifiedroom air temperature of73.4 

### °F, not 71.4 °F as stated in the comment, and tank water temperature 

### of. 150 °F. Then, the standby loss equation

was used to project the losses that would occur with and 80 °F temperature rise. Therefore, the standby losses · calculated were based on an.SO °F temperature difference, not the 76;6 °F difference stated in the comment.

Withrespect to emissivity levels, DOE modeled a range ofwater heaters at 0.1. 0.5. and 0.9 emissivity. The data reported inFigure 3 indicated there 

### is no appreciable difference between emissivity levels.

BIWNG CODE 6450-01-U

### Federal Register: 

## I Vot p5, No

..113 

### /Tuesday, Ju,ne 12, 

### 1990 

### /Rules and 

### Regillations • ; i • 1 

### 23855 ' ! ' •



# ELECTRIC 

# VIATER HEATER STANDBY LOSSES
50 Gallon Electric Model**2..1.--....-~~-.-~-r-~-r-~-.----r~-.-~-.-~..,.-~r----..~-.-'** 

### 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 lnsulaiion 

### Thickness (in.)



### ---- Fiberg!ass-.5 -+- 

### Foam-.5 Emis**~** 

### riberglass-.9 -s- 

### Foam-.9 Emis



# ·---- ·-----·---- Figure 

### 3

- Sensitivity to ssivity

### 23856 

### Federal**Regist~~** 

## l VoL**5~,** 

### No. 113 

## l TuE)sday, June .12, 1.990 / 

### Rules and Regulations

b. Manufacturer TestData vs. DOE Calculations. 

### State Industries, Inc. and Bradford-White Corporation stated that they had tested waterheaters of approximately 50-gallon capacity. They and GAMA refer to these tests and concluded that the DOE model is invalid because the DOE predictions of standby loss for 

### that size unit 

### are far less than their test results. Mr. Collins of State Industries, Inc., concluded that DOE had used too low a jacket emissivity, and did not take into account otherlosses

.such as those that occur through fittings. values, and clean-out op,enings. GAtl.1A and SI commented that it

### was necessary to use two inches offoam insulation around the tank (except around the thermostat/heating**~lement/**

### control

area where two inches offiber glass are used) to meet the current 4 

### W

## /ft 2 

### criterion, as opposed to the DOE calculation oftwo inches offiberglass. GAMA further commented that DOE had neither used empirical data nor validated its 

### model against empirical data. GAMA 

### citedASHRAE Research. Project 502 where such a comparison had been made using.a simple model and blanket insulation. They further cited this project as concluding that insulation exceeding R-50 wouklbe needed to achieve a standby loss of

### i.9 W/ft2 •

DOEResponse: 

### No supporting unit description, test description, or test data

were provided by the manufacturers or by CAM.I\. upon which DOE could evaluate the comments relative to the tested units.

DOE commissioned tests at NIST on a unit similarto the capacity ofthe units which the manufacturers stated they had tested [NIST Letter Report, 1990]. The results of standby tests showedthe unit as shipped performed very poorly relative to published claims: Simple correction ofmajor the.rmal bridging resulted in a 28 percent heat loss reduction. Data from the tests ofthe modified unitand from the unit with an insulation blanket added were used in a comparison with the predictions of the DOE model. The model was able to predict the results within a factor of ±15 percent.

A Bradford-White commercial electric water heater, model M-I-50-12-35F115(S/N GC013836), was purchased from

a local distributor for evaluation, The tank had an advertised (nominal) capacity of50 gallons. AH tests were conducted in accordance with DOD's Energy Conservation Progam for Consumer Products, 10 CFR Part 430**(Janu~ry** 

### 1, 1985) in lieu ofthe test procedure specified within the Energy**Pcrfor~ance** 

### Standards for Commercial andMulti-Family High Rise Residential Buildings, ANSI Standard C72.1. The cited ANSI Standard has been withdrawnby ANSI.

Measured standby losses for the unmodified electric water heater were 120.3 

### watts perhour or 5.67 W/ft2 of 

### tank surface area. This exceeds compliance with ANSI/ASHRAE/IES Standard 90A-1980's criterion 

### of4 W/

### ft 2 

### that was in place until December 1989.

During the initial tests, the bottom of the jacket on the water heater and the metal enclosure housing the heating elements were identified as sources of 

### excessive heat loss using an infrared

scanner. The tankhad severely compressed the fiberglass insulation on which itrested so as to be almost ineffective. This permitted the heat to travel from the tankto the sheet metal bottomjacketmaterial and hence to outside edge ofthejacketwhich was hot
to the touch. The bottom ofthe tank was removed and void spaces between the jacket and storage vessel filled with foam. The tank was placed on a two inch piece ofextrudedpolystyrene (R-10).

The enclosure, which permits access to the heating elements, was altered by removing a portion which was in contact with 

### the storage tank The unaltered enclosure provided a'direct path for heat flow from the storage vessel to the surrounding ambient air. Approximately hvo inches offiberglass insulation was installed in the area previously occupied by the removed metal. Measured standby losses fpr this modified tank

were 86.2 watts perhour or4.00 W/ft2 

### of tank surface area, thereby bringing it · 

### close to compliance with ANSI/ ASHRAE/IES Standard 90A-1980. This represents the 28 percent reduction in the heat loss from the storage tank.

The tank, modified as described above:was wrapped with an R-11 

### foilfaced fiberglass insulation blanket.The' measured emissivity ofthe foil 

### is 

### O.o3. The blanketwas installed over the · entire exterior ofthejacket with the exception ofthe bottom surface ofthe tank. A foil-faced R-11 battoffiberglass insulation was installed in the enclosures that house the heating elements and fuses. Measured standby losses for this configuration were 69.7
watts per hour or 3.29 W/ft2 

### oftank surface area, and were 42 percent less than the losses measured for the unmodified electric water heater.

-

Based on the preliminary analysis conducted for the Preliminary · Statement, 50-gallon electric water heaters were shown to comply with the ASHRAE Standard 90A-1980 4 

### W /f1 2

. 

### criterion with approximately 1.5 inches offiberglass insulation. A reconsiderntion ofthat analysis, which includes components ofheat loss for fittings and controls, indicates that approximately 1.5 inches ofform would be required to reach 4 W/ft2 •



### The computer simulation was designed to assessjacket losses from 

### water heaters under steady-state conditions. When the results ofthe computer model are added to published data on fitting losses. the resulting total standby loss concurs with test data supplied by NIST.

c. Tank Surface vs. JacketSurf ace. 

### Four comments questioned whether the insulation requirements ofthe DOE standby loss criteria pertain to the tank surface orjacket surface of an electric waterheater. Mr. Daugirda ofRheem Corporation stated that many more commercial units covered by the DOE standards could meet the waterheater standby loss criteria ifthe tank surface is used to determine the f.9 W/ft2 

### maximum standby loss. However, if 

### jacket surface area is used, he said, the criteria remain infeasible. Mr. Daugirda maintained that this should be reflected in revised DOE 

### standards. He suggested that the standby loss requirement should.be changed to read as follows: SL<25 W

# +2.6. 

### W/ft2 

### oftank surface

area. This changeis reques_ted for water heaters having volumes up to 

### 120 gallons.

GAMA also submitted data to support its assertion that DOE remain consistent with the criteria used for the last fifteen years, and should specify that its standby loss requirement is to be based

on the surface area ofthe tank.

Mr. Jim Hildenbrand ofASHRAE

.. request that DOE change itscrHeria to be consistent with the standby loss criteria in the recently issued ASHRAE/ • IES Standard90.1-1989 whichis expressedin W/ft2 

### oftank surface area. ·

DOEResponse:

### DOE agrees with the comments that DOE should not set its standby loss criterion

### for electric storage waterheaters in terms ofjacket surface area.DOE believes that it 

### is

- likely that the jacket area ofdifferent manufacturers will vary between water heaters ofthe same capacity and input energy, depending on the aspect ratio of the tank, the insulation used, and varying design and manufacturing needs. DOE further believes that the jacket area of a unit should not include the surface area of the box containing wiring, controls and thermostats, which project from the side ofmany water heaters; and that it would be unnecessarily complex to express this concept in a definition to covE;?r those and similar conditions.

### Feder~l**R~gister** / 

### Vol. 55, No. :113 / 

### ··Tues:day;

### ·J~ne 12, 1990 

## I**Rule~** and Regulations 23857

"noE also evaluated expressing the criteria in terms oftank surface area. The**tar~** ofmany ofthe units are not simple right cylinders. They have a
concave bottom and convex top. This raises the question as to whether to calculate the area ofthe tank as a right cylinder or to refine that calculation to account for the deformed top and bottom. Furthermore, the dimensions of the tank are not generally provided in the product literature ofthe manufacturer. Fabrication drawings would be the only consistent source of tank dimensions. In addition, it is slightly more difficult to calculate the a1eas ofthe convex and concave surfaces. Therefore, DOE concludes that it is more appropriate to express the criteria in terms oftank surface area than in terms ofjacket surface area. As s:.Jch, the criteria announced today are expressed in terms of tank surface area.
E. Com111enta on 

### Gas Storage l-llater 

### Heaters

1. Construction Characteristics

DOE received comments from the three water heater manufacturers and GAMA that implied that the physical dlmensions used in modeling commercial gas storage water heaters

were incorrect. The comments indicated that DOE's assumption of a single large diameterflue tube through the center of

a waterheater tank results in undcrcalculating the uninsulated heat exchange area for that loss, and incorrectly calculating actual heal loss coefficients. They further stated the assumption ofa single flue tube also leads to the incorrect eupposition that a flue damper located on the end ofthe flue tube and in the closed position effectively seals the flue tube.

These comments indicated that if DOE's analysis had used the practical design construction necessary for the heat inputs required by the water heater market. it would have used a multifhrn construction, typically six or seven flues. The multiple flue tubes are much smaller in di;imeter than in the DOE model and are equipped with flue baffles. They have a different heat loss coefficient from that ofa large diameter unbaffled flue tube. For instance, two, 3- inch diameter flue tubes have the same surface area as a single, 6-inch diameter flue tube, but each 3-inch tube only has one-fourt.11 the volume ofLlie 6-!nch tube. · This diameter-to-volume ratio affects the flow ofheat from the flue tube wan to the air and the resultant standby heat loss. Multiple flues require the use of a flue collector box located above the tank and before the flue outlet ofthe
water heater. The flue damper is installed on this flue outlet. The flue collector box essentially covers the entire top ofthe storage !ank and is there to four inches high. Tbe top insulation ofthe water heater is located between the flue collector box and the top ofthe waterheaterjacket. The surface area ofthis box becomes an additional area ofstandby loss on the 1Nater heater.



### DOEResponse: His clear that there is

a misunderstanding ofthe assumptions DOE used in its modeling approach. The assumption ofa single flue was made to develop an estimate ofthe increase in tank dimensions to accommodate the volume of waterrequired. The model 

### d;J
not attempt to account for the detailed heat transfer from internal flue passages to the water. Instead the model assumed

a uniform water temperature a::i indicated in the Technical Support Document. For the purpose ofmodeling jacket heat loss, the difference between single flues and multiple flues is not significant.

The commenters suggested thal the assumption ofa single flue versus multiple flues results in some errors in estab1ishing the effect offlue dampers. The fact that the flue damper is located within the collector box and covers the multiple internal flues does not necessarily result in different performance from a single flue with a damper at the flue exit. The intent ofthe flue damper is to retain the hot flue gases within the flue rather than allowing them to escape up the flue. The location of the flue damper is immaterial ifthe effect ofits location does not change.

2. Jacket Heat Loss

State Industries, Inc., Bradford-White Corporation, and GAMA argued th.at DOE erroneously assumed that using flue·dampers and electric igniticn devices (IIDs) would eliminate most of the tank heat losses other than those attributable to jacket losses. They pointed out that DOE calculated energy savings based onjacket losses of70 percent to 90 percent ofthe total losses, and contended that with the addition of flue dampers and 

### Ills, jacket iosses are between40 percent and 50 percent of the total standby losses. Nearly one-half
to 60 percent ofthe losses are unaffected by increasing the thickness ofinsulation. GAMA referred to, but did
not identify, two manufacturers who apparently conducted tests on their own units to prove this point, and partial test information was included in their
comments.

Another criticism ofthe assumptions

was that DOE made no attempt to

measure the percentage loss attributable tojacketloss. It stated that DOE's analysis assumes that models currently equipped with flue dampers and IIDs havejacket losses that account for 70 percent ormore ofthe total standby loss. However, .GAMA and Stale Industries indicated that in no case did the. analysis measure the percentage of loss attributable to jacket loss on such
water heaters. GAMA and State Industries indicated that manufacturers' experience and knowledge gained in improving the efficiency ofcommercial storage waterheaters show that the losses through the flue still account for 50 percent ormore ofthe total loss. GAMA, Bradford-White Corporation, and State Industries contended that although effective in diminishing a majorportion of the flue gas loss, flue damp.ers do not eliminate that loss entirely. Rather, the s!eel damper that obstructs the hot flue gas will be warmed and conduct heat away from the system. In the open the damper is subject to thermal expansion due to continual exposure to the high temperature flue gases exiting the waterheater. When the burner shuts offand the damper closes, it will cooi down. As it cools down, the damper will
contract slightly. Thus, GA.l'v!A and State Industries maintained, even putting aside the realities ofproduction and fabrication tolerances, a damper that might seal tight when first closed, might
not maintain that seal.

Dr. Goldstein ofNRDC commented that flue dampers were necessary to meet the DOE standards, and promoted the idea ofusing flue dampers in conjunction with additional insulation

on commercial gas waterheaters.



### DOEResponse: Although experience and knowledge, and some testing, wer·e given as reasons for the negative
comments on the use offlue dampers and IIDs, no -substantive information

was provided. To more fully respond to those who commented, it would have been necessary for DOE to receive data

on the characteristics ofthe units tesled by the manufacturers, particularly on the flue damper used and the jacket and flue collector box insulation. Without such data it is not really possible to evaluate this statement fully.

DOE believes that those who commented misunderstood the DOE analysis. DOE assumed, for the purpose 

### ofits analysis, that after a flue damper and electronic ignition device were added to a commercial gas storage water healer, 70 percent of the remaining heat los3 would be through the jacket. This presumes that 30 percent of the loss remains through flue and pilot losses and that the standby

### Federal Register / Vol. 55, 

## 'No. i::l'3. / TU:esday,'Jilnec12, 

## 1990 /Rules 

### and**R~gulations**

loss criteria cannotbe attained simply by adding insulation.

DOE

### does not consider acceptable the contention ofthose who commented that
50 

### percent or more ofthe loss comes through the flue despite the presence of

a flue damper. First, while it

### is understandable that flue dampers are not 100 

### percent efficient, it 

### is also -conceivable that betterdesign and production and the more predominant

use ofelectronic flue dampers can rectify much ofthe residual heat loss. Second, the DOE test on a commercial gas waterheater 

### at NIST 

### indicates 

### that total he,at loss without a flue damper during the cool down mode ofthe test procedure is approximtely 50 

### percent during the first 24 

### hours. With the flue damper, the percentage heat loss during

a similar 24-hour period was only about 30 percent. See Figures 4 

### and 5. These figures were based on the total standby losses minus those through the jacket, fittings, gas valve, and piping losses. While not confirming the percentage thermal resistance provided by a flue damper, the test was illustrative ofthe effect flue dampers can have.

In regard to Dr. Goldstein's comment, DOE agrees that flue dampers are an integral part of water heaterenergy conservation and that they, along with IIDs, shouldbe added to units that
cannot now meet the DOE criteriawith insulation only.

BIU.il>lG COO£ 64!;G-OH\l

### Federal 

### Register/ .Vol. 55, 

### No. 113 

## I Tuesday, Juae 12, 

### 1990 /Rules and Regulations 23359



# GAS WATER HEATER WITHOUT FLUE DAMPER

COOL DJWN TEST

- NIST TEST RESULTS

n 

### " I- 

## as

ro ::;; 0.7 <t: l ;.'.**~** 0.6 ;- 

### '::I 

## ::: I::: 0.5 

### ::::

v 

### ' 0.4

### ~' w

m 0 3**~** I**~** 0.2 <iIv 0 1

O' 

## d

# l 2

# I 4

# J!fT I 10 12 

### I 11 16 18 20 2'2 24 

### I 26 28 

## I30 3?_ 34 

### " 1 9 11 

### 13 15 1 f i 21 23 2's' 2 29 31 33 3 ELAPSED T**lf~E** ( HOIJP.S)- NIST TEST RESULTS



### Figure 4--NIST Gas Water Heater Cool-Down Test v/out Flue

### . 23660 FederalRegister

## JVol; 55, No. 113 /Tuesday, June 12, i990 / Rules and Regulations

.



# GAS HEATER WITH TOTAL FLUE RESTRICTION

COOL DOWN TEST

- NIST TEST RESULTS

0.9 

## " " I- 

### o a z UJ
a:i ::i 0.7 <( I**~ ~**  0.6 I- 

### ':f**~** I- 0.5
z

u 

### ' 0.4 

### t:' z liJ
ID 0.3**~** I**~** 0.2**~** u 0 1

0



## Figure 5 - NIST Gas Water Heater Cool-Down Test w/ 

## Flue Damper

Ellll.ING CODE 6450-01-C

### Federal Register 

## I Vol. 55, No. 113 

### /Tuesda:it. June 

### 12; 1990 

## I Rules and 

### Regtilations

3. Insulation.

DOEreceived three comments concerning insulation. Mr. West 

### of Bradford-White Corporation indicated that 

### theheat exchange surface needed for the efficient transferofheat for the combustion process, thebottom area of the tank, cannot be insulated in a practicalmanner, He stated that DOE apparentlyfailed to account for this in the analysis. Since the need to transfer heatexists during combustion, a similar transfer ofheat occurs during the periods of standby operation.At this time, heatflow begins to reverse in its direction, therefore, heatloss emanates from this neededuninsulated area.The
waterheaterbottom area is efficient in transferring combustion heatbut it also adds to theheatloss during standby periods.

Mr. Stanonik ofGAMA statedthat DOE's analysis underestimates the standbyloss through the top ofthe storagetank because itplaces the insulation on top ofthe waterheater. Theinsulation on the top ofthe water heateractually is on the top oftheflue collectorbox. not on top ofthe storage tank. With an air space ofthree to four inchesbetweenthe top ofthe tank and the top ofthe waterheater, there willbe

an appreciablylarger loss through the top ofthe tank than predicted by the DOE analysis.

Finally, GAAIA commented that the DOE standby loss criteria contradicts severalofthe studies and reports referenced by DOE. Mr. Stanonik suggested that at some R-values of insulation there is no significant potential for saving energy by further increasing the insulation levels. The 1982 "ConsumerProducts Efficiency Standards Engineering Analysis Document" prepared byArthur D. Little, Co. for DOE and cited as a reference

source in the development ofthe standby loss requirements for electric residential waterheaters states that the point at which further insulation isnot b1meficial is an R-value of about 14. For residential gas waterheaters, the report indicates that the samepoint is an Rvalue of about 16. These levels are consistent withinformationin a 1977 study by OakRidge NationalLaboratory entitled, "Energy and CostAnalysis of Residential Water Healers" and the 1979 National Bureau of Standards Reportentitled. "Evaluation ofEnergy Conserving Modifications for Water Heaters." The DOE analysis suggests that this critical point is anR-value of21 for commercial electricwaterheaters and an R-value of 18 to 21 for commercial gas waterheaters, de.pending on what percentage of standby loss is.attributedtojacket losses. The DOE analysis suggests 

### a larger.optimal thickness ofinsulation than the otherstudies, even thoughDOE used these studies to establish its standby loss criteria.

DOEResponse:DOE understands that the bottom surface ofa gas waterheater is uninsulated. In its analysis, DOE included any heatlosses from this surface in the category ofotherlosses. The other loss category wasused 

### to include all areas ofessentially uncontrollable losses such as thebottom surface andthe flue losses. No pubhshed data was available on the
amount ofheatlosses attributable to the bottom surface ofgas water heaters whichwould allow for treating this loss separately.In addition. manufacturers' data indicales the configuration oftl1e bottom surface ofthe waterheaters as well as theburnerunitsvaries among different manufacturers.

While itis true that during standby conditionsheatwill tend to flow from the warmerwater out through the bottom surface to the surrounding air, the actual heat loss willbe lessthan suggested due to the natural tendency for heat torise. In addition, test data has shown that the temperature ofthe water in the bottom ofthe tank will be less than the temperature at the top ofthe tank. As a consequence, si.r1ce the heat loss is a function ofthe temperature difference between the water and surrounding air temperature, heatloss through the bottom ofthe tank 

### ·will be lower than through other areas ofthe tank surfaces due to the lower temperature differences.

The commentorindicated tJ1at insulation on the top ofcommercial
waterheaters is placed on top ofthe flue collector box and not on top ofthe storage tank as assumed in the D0E analysis.For the Bradford-White commerical gas unit tested byNIST, the insulation is located on top ofthe storage tank.DOE believes that the location ofthe insulation assumedfor the modeling is appropriate and consistent with current construction practices.

The DOE standby loss criteria does
not contradict the other studies and reportsreferenced byMr. Stanonik.The analysis performed to support the
current criteria was based oncurrent costsfor energy, laborand materials. The previous studies were conducteda_t least eight years ago, one ofthem beL.1g 13years ago. Costs have changed since Hie publication ofthosereports. and the change in costsis reflectedin the
current analysis. Additionally, the referenced studies dealtwith residential versus commercial waterheaters. DOE made adjustments inits analysis ta

_ account for the differences in size, construction techniques and operating conditions between commercial and residential units. In fact, results from

someofthe referenced reports were used in correlating theDOEmodel to the NIST test data.

4. Surface Emissivity

Comments from Rheem, State Industries, and GAMA eachindicated that DOE underestimated standby losses in commerical storage water heatersby using an emissivity factor of 0.5 rather than 0.9. Mr. Daugirda of Rheem Corporation stated thatthis

causes a three percent discrepancy. According to the GasEngineers Handbook (The Industrial Press, 1965}, the surface emissivity ofvariouspaints ofdifferent colors and types is0.9 or higher. AH thejackets ofcommercial storagegas waterheaters are painted. Therefore, the 0.9 emissivity value should have been used in the analysis. The direct result ofutilizing a higher number wouldbe increased standby heat loss.

DOEResponse:The emissivity values chosenfor the DOEmodel were taken from a widely accepted heat transfer
textbook with similardata to the 1955 edition ofthe GasEngineersHandbook [Heat Transf er, anAlan Chapman Engineering Text]. The value for a painted surface was in the 0.9 range. However, at the time ofthe modeling, DOE was aware that some units are offered with stainless steeljackets and it was assumed that not all the surfaces

were painted. The value for a stsinless steel surface was 0.1, so an approximate average ofthese two was calculated to arrive at the 0.5 emissivity factor used in theDOEanalysis.

Using an emissivity of0.5 rather than

an emissivity of0.9 results in an extremely small difference in the calculated standby loss.Thecomputer analysis was run at three separate levels--0.5, 0.7, and 0.9-andDOE found little appreciable difference in standby loss rates at any level ofadded insulation. For all subsequent analysis,

, DOE used 0.9 surface emissivity. See

Figure 3.

5. Water Heater Fittings

Bradford-White Corporation and GAMA indicated that waterheater fitting(s) losses are distinctly different from thejacket and flue losses and need
to be consideredin any analysis. The
comments maintained that DOE's analysis underestimates standbylosses becal!se it does not considerthe. standby

## 23862 ·,Federal Register/ Vol. 55; 

### No. 113 

# I Tuesday; June' 12, 

### 1990 

# I Rules and Regulations

losses that occurthrot1"gh such**fittings~** 

### Thelosses from thermal leaks created by fittings 

### that connect through the insulation to the tank contribute to standbyloss but are not affected by 

### the addition ofinsulation. The 

### comments cited an ArthurD. 

### Little, Co. report entitled, "Study ofEnergy Saving. · Options for Refrigerators andWater Heaters," published in 

### 1976, that determined that the fitting 

### losses are about 85 

### Btu/h in a residential gas water heater and about 110 Btu/h on a. residential electric waterheater. Considering that the fittings 

## on commercial storage.tanks

# wm be larger and that such tanks 

### also acid a Clean-out valve, the fitting losses on cmnfnereial· storage waterheaters 

### will

# at least be comparable to residential**units~** 

### These fitting losses represent overfour percent ofthe 0 

### 90 percent allowable fosses" of 1932.26 Btu in.DOE's analysis for the 

### 100-gallon gas model and almost 20 percent ofthe "90

### percE!nt allowable losses" of539 

### Btu for the 

### 120-gallon electricmodel.



### DOEResponse: In. 

### the initial modeling, DOE used an aggregate numberforfitting losses'. Subsequently? further information wail identified and used in the latestmodeling runs. For

.. electric waterheaters; Hie total standby loss for fittings was 100.85 B,tu/h. The number for gas water heaters is approximately 75 

### percent ofthe electric fittings losses because controlsare not included. Figures 1and2illustrate the

avenues ofstandby loss for electric and gas waterheaters. Subsection D ofthis Section contains additional information relevant to this topic.

6. 

### HeatTraps

DOE received one comment from GAlvlA 

### concerning heat traps. 

### Mr. Stanonik stated that there is a conflict between the DOE analysis and an earlier DOE**document~"1982** 

### DOE Engineering Analysis Document". In the 

### papers submitted in response to 

### the lawsuit filed by GAlvlA, 

### DOE stated that the use ofheat traps were not factored into the establishment ofthe standby loss requirement. Mr. Stanonik contended that the 

### use of lhe 1982 

### DOE document as a 

### primary reference contradicts this 

### statement. Furthermore,**~~·"~**..**~**....,, to 

### Mr. Stanonik, at 

### a February 11, 1990, of 

### the ASHR.l\E SSPC 90R 

### Service Waler 

### Heating Subcommittee, ASHRAE factored in the 

### benefits of

### heat traps even though neither the referenced test procedures

nor the 

### text ofthe ASHRAE specifications allow for a credit for heat traps in the determination ofa water heater's standby loss. 

### .DOEResponse: In 

### setting the standby ·loss criteria, DOE has not assumed tha·t any or all waterheaters will come with integral heat traps. Heat traps that are integral to 

### the unit, which are more efficient than the 

### heat traps required of the 

### testprocedure, would receive credit from the 

### gas waterheater test procedure. GAMA 

### thus misconstrues or misrepresents DOE's reference ofthe 1982 DOE document. DOE has included heat traps in its standby .loss calculations per the requirements ofthe 

## test procedures and the January 30, 1989, DOE

### Interim Standards. In the ANSI 

### gas waterheater test procedure, heattraps

on both the inlet and outlet ports are to be installed 

### ifnot already present before testing. In 

### addition all inlet and outlet piping iμcluding heat traps (or a length offour feet from the tank is insulated to



### a mii:liinum R-4. A 

### temperature and pressure reliefvalve is also to be installed if

### not already and insulated to 

### R-4.

TheANSI electric waterheater test methoddoes not require heat traps and

. insulation on temperature and pressure

reliefvalves, Association insulation, includingpipe, are not required to be installed or addedprior to testing.

The'DOE Interim Standards require heat traps to be installed on storage w.ater heaters when not supplied as part of

### the unit. Circulating systems do not require heat traps. The standards also require piping on storage waterheaters
to be insulated to R-4 

### for the first eight feet from the tank, this would include traps, for inlet and outlet connection sizes up to 

### two inches. This will include most units up to 

### the 300-gallon range. Insulation with a thermal resistance of R-6 

### is required for 

### connections above two inches. The standards do not specifically require insulation on relief valves.

The primary difference between the test procedures and the DOE standards is the additional four feet ofinsulated inlet and outlet piping. In the case ofan operating tank. with hot waterbeing drawn from 

### the tank, 

### the entire pipe will be full 

### ofhot water and an additional four feet of

### insulated pipe out of 

### tens and hundreds offeet oftotal will 

### have very minimal effect. """""''" situations, the heat**~~•me•~·** 

### heat transfer
to the
return ofadded 

### insulation, of the 

### additional four 

### feet beyond the tank during standby periods

# wm also have little effect The test method also credits insulation on reliefvalves, which is not

, cLmu.cu

### by the standard.

DOE has 

### included these requirements in developing the model that estimates waterheaterrequirements to meet the DOE standards. Manufacturers should alreadybe aware ofthese requirements for use in their own 

### testing.

DOE rejects the assertion that neither the testprocedures northe ASHRAE/ IES 

### Standard 90.1-1989 requiresheat traps; in fact, they bothincorporated heat traps. The insulation on the trap and pipe in the test method is equivalent to that required by the standards, hence,

a more effective internal heat trap may well reduce additional standby heatloss not addressed by the R-4 

### pipe insulation required in the testprocedure.

It 

### should be noted that while DOE has found it

### beneficial to listen to and participatein the deliberations of ASHRAE SSPC 90R, DOE has independently considered the

. information received and reached its

own conclusions.

7. 

### WaterHeaterRecovery Efficiency

DOE received one comment, from Rheem Corporation, indicating that the

use of75 

### percentrecovery efficiency is misleading when applied to the recovery ofstandbylosses. Mr. Dauffirda of Rheem stated that the thermal efficiency ofcommercial gas storage water heaters is determined under steady-state conditions and that during the course of the standby loss determination, the recovery efficiency for the short recovery cycles are in the 60

### percent range. Therefore, according to Mr. 

### Daugirda, the recovery efficiency is variable, depending on the mass ofthe waterheater in 

### additionto the stored water that is to be heated.

DOE

### Response: In 

### the DOE model,· recovery efficiency has been assumed to 

### be equivalent to the thermal efficiency ofthe waterheater. Rheem states without supporting information that the 

### recovery efficiency is much lower than that. For the gas waterheater tested by NIST, the recovery efficiency was 72 percent, or very close to the 75 percent efficiency rating ofthe unit 

### tested.

8. 

### Measured Data

Bradford-White Corporation maintained 

### that the DOE analyses were


### as shown manufacturer 

### tests in response to DOE's
""""u''"'CJ' 

### Statement In 

### an to verify the DOE 

### conclusions, Bradford-White Cornoration constructed and tested a

. gas i•1rater heater nn;tntvr1"'

,**-~··~.-·~~** Btu/h with 

### and HD, and two inches external i;:isulation. 

### With the 

### additional insulation, a total 

### R-value of 10.3 was 

### achieved. The 

### test results for 

### this unit indicate a 2.02 

### percent standby 

### loss perhour. Mr. WestofBradford-White contended, therefore. 

### thatthe achievement 

### ofa 1.63percentperhour r standbyfoss rate isnotpossible under the conditions specified in the DOE analysis. Inaddition.the 2.02 percent vaiue can only be achievedunder laboratory test conditionsbecause in realuse situations ssveraI water.heater externalities, such as the controls and drain valuefittings cannotbe covered by the insulation wrap.



### DOEResponse:The commenter provided

# no data to substantiatehis argument that test data indicated that available gas units couldnotbebrought into compliance. Testdata provided by t:11e California Energy· Corn:mission indicates that several gas water heaters that are commerciaHy available do comply with the current standby loss criteria. The test data providedby NIST indicates thatwhen properly insulated the 

### testunit actually exceeds the standby loss. criteria.

9. Cost Benefit Analysis

a. 

### Modeling andAssumptjons.· Comments were received from State Industries, Rheem, and GM1Athat criticized DOE's cost-benefit analysis model andthe assumptionsused in developing the model. These comments argued that the energy calculations,.the
cost data, andpayback periods were wrong. J'hey indicatedthatthe cost of addinginsulation,includinglabor, retooling costs, andprofit, wasbased on residential storagewaterheaters and
not commercial waterheaters.Finally, they assertedthatDOEdid notprepare
a· complete cost-benefit analysis. They pointed.out thatDOEdid recognize · currentmodels ofgas storage water heaters. all low input models, that. comply with existing standards and will comply 

### wit.Ii the DOE standards

### ifflue dampers and llDsare added

..They maintained.however, thalDOE's analysis does notreflect the true costs of addinga flue damper Ol'an IID.

It was suggested that

## OOE could have conducted a more detailed analysis

### ifit had surveyed suppliers ofcommercial
waterheatersto obtaincostdifferences in comparable models, with and without flue dampers and IIDs.**GA~LJ\** pointed
out that DOEwouldhavediscovered that the addition oftheflue damperand IID raises the price ofthe water heater by $500.00 ormore. Comparing this cost to thebenefit calculated by DOE. the. flue damper andI!D option wouldhave

a simplepayback ofalmost 14 years underthe most realisticconditions of usage.Therefore, GAMA concluded that DOE's decision to establish a standby loss aUerfa torequire flue dampers and IIDs onnon-equipped models isnot economicailyjustified.



### DOEResponse: Inattempting to establish the costsfor adding insulation. flue dampers, and IIDs, DOEsought information from the industry to establish representativa costs. Various manufacturers were contacted to secure cost information. Unfortunately the
commenters did not supply information
to substantiate their claims that the DOEinformation developed aspartof this process was incorrect. Costsfor retooling and profit were not separately included in the DOE analysis, and thus
cannotbe presumed to beincor:recl All ofthe data collectedby DOEwas solicited based on current reta.il cosf,3 for commercialrather than residential units.



### b. Cost/Benefit of Flue Dampel's and I!Ds. DOEreceived three comments from Rheem Corporation, BradfordWhlte Corporation, and GAM.>\ concerning therequired addition offlue dampers andIIDs to many models currently on the market 

### ifthese models

are to meet the DOE standby loss· criteria. The DOEanalysis assumesthat the benefit oftheflue dmnper andIID

occurs 24-hours perday.The comments argued that it should be obvioustoDOE that when a waterheaterburner is operating, .the flue damper is not 

### dosed. They maintained that a generous estimate for the standby period is 20 hours. Based on 24-hour perday standby, DOE estimated annual savings of$30,41. Using the 20-hourper day figure, the comments estimated annual savings of$21.29.They alw argued that the true cost ofthebenefit was not analyzed.

### Mr. West ofBradford-White

. indicated thatthe additionofa flue damper andIID increases the water heater costby $594.000 to the consumer. At $21.29 peryearin energy savings; the payback period would be28 years instead ofthe DOEestimate ofthree years.



### DOEResponse: Assuming that the units are not firing for 20 hours dai!y, a reduction ofhoursfrom 24 to20 results in an approximate 17 percent change in time for potential savings. Adjustingfor

a normal work week, the :reduction is about 8 percent.The commentors contend the changei:n savingswould be

on the orderof30percent which is inconsistent with the change in operating hours. DOEbelieves, given these assumptions, that its cost-benefit analysisremains valid.

With the exception of several ofthe smaller units, DOEassumes that flue dampers andlIDs

# wm be required on aU gas waterheaters to meet current as weU asfuture national standards.Thus the added cost ofthese devices is vfrtually nil since they would havebeen requiredanyway in the absence ofthe DOE standard.

When setting new, more stringent standards criteria, it islogical to assillne that 

### a few model offerings that previously only marginally met the former criteria may notbe cost effectively modified to meet the new criteria.DOE has not analvzed the variety ofengineering strategies heretofore used by manufacturers to obtain minimal compliance with the prior standards, but which would not be necessary should more effective

measures be incorporated to meet the

new criteria. Forexample, ifbaffle dampers should be replaced by electronic dampers for thatpurpose. Hence, DOE believes its cost benefit analysis is quite reasonable.

Where it is marginally effective to' modify such units they maybe offered

as options or discontinued in favor.of otheroptions.' Ifdiscontinued, designers will select other alternativesfor the market, eitherroundingup ordown factors used in theirsizing assumptions. For example, a "residential" sized and fired unit may be selected.

c. 

### PaybackPeriod. GAMA commented Hmt DOE should not use any payback period longer than five years. In the Preliminary Statement, DOEidentified a three- to five-year payback as acceptable in the nonfederaI sector and seven to ten years as acceptablepayback for federal agencies. GAMA commented that

### if any payback in excess offive.years isused, the more expensiveunit may never pay back because the unitmay fail in the interim. A typical commercial storage water heateriswarranted for three.years. Two majorfactors affect water heater lifetime-the amount ofwaterrequired

. and the quality of that water.These factors vary greatly in commercial applications, and likewise so does the range of service life ofcommercial storagewaterheate.rs-less than three years to more than ten years. A representative, typical servicelife is five years.



### DOEResponse:The typical payback periodscitedin the DOEPreliminary Statement stem from the factors normally used

### by DOE to assess energy conservation measures in buildings. The Federalgovernment, being the ovvner/ operator ofitsbuildings, generally specifies materials and equipment built
to last a great deal longer than in some parts ofthe non-federal sector. Therefore.itis willing toinvest in energy conservationmeasures that have

a longerpayback ifthe measures are to

### Federiil Register / Vol. ·55, 

### ··No; 113 

# f Tuesday', June 12. t990 ··/ 

### Rules and ·Regulations

· be life"cycle cost-effective•.Ail 

### purchases for federal government

. buildings,cespecialiy for energy· conservation, mustbejustified as 

### lifocycle cost-effective using a methodology developed byt NIST (subpart A of 

### 10 

### CFR part436). ·

The three

## to five-year payback for the non-federal sectoris .responsible. It 

### should be noted thatthe DOE costbenefit analysis indicates 

### thatmuc.h shorterpaybacks are possible When factoring costs related to 

### lower standby loss levels. d. 

### V.alue of EnergySavings; GAMA commented that DOE's analysis overestimated the va:lue ofenergy · savings for gas waterheaters. DOE estimated anannual energy savings of $32.53 fora 100-gallongas water heater, with 70 

### percent loss through thejacket. Mr. 

### Stanonik of

### GAMA believed the annualenergy savings estimate should be between $9.33 and $13.34, depending 

# on the variables used in the analysis.'



### DOEResponse: DOE has reviewed the calculationofsavings in Table 5 ofthe Preliminary Statement and concluded . that they were made using a base assumption of0.5 inches ofinsulation and the'addition of2**inch~s** 

### of · · insulation to meet the criterion, for a 

### total of

### 2,5 inches ofinsulatfon. DOE believes thatTable 5 

### Mthe Preliminary Statementshould have been calculated

· on 

### a base assumption of 1 

### inch of

insulation and the addition 

### of2 

### inches ofinsulation to meet the criterion; for a total ofthree inches ofinsulation. This wouldresult in 

### a savings of$15;80 and a simple payback of4.64 years. A revised Table 5 

### follows:

TABLE 5 (REVISED).-£NERGV CoST SAVINGS AND FIBERGLASS CoSTS DUE TO 

### DOE INTERIM STANDARDS (WITH 70 PERCENT. LOSSES THROUGH JACKET AT ANSl/ASHRAE/IES STANDARD 90A-1980 CoMPUANCE LEVELS).

Tank capacity·(gallons) · Energy savings (dollars) Fiberglass {dollars) Total • (doUars) Payback years

100................•.........

- ............................. 15.80

..................................- ........ 29.34.-

......................................... 73.35;

........................._ ............... 4.64 129

....:

..,...................................................14.89

.......:

...................................: 22,01

............................................ •5s.01

.............;

......;_

.................:. 3.69

## :~~ :::::::::::::::::::::::::::=:::::::::::::::::::::::::=:·

## ~~:~::::::::::::::::::::::::::::::;::::::::::

## ~**i~;**::::::::==:::::::::::::::::::::::::::::::·

## ~:~~::::::::::::::::::::::::==:::::::::::::::

## ~:~: 594

.......................................................... 22:14

...- .......................;

.............. 1s.n

.............,............................. 46.91

...............................**~**............ 2.12

•The total cost. is based on studies·that show the· !Ola! ·increased cost is approximately 2.5 

### limes the cost of the fiberglass· insulation. (See Blue 1979.)

Note.-That the above table does not · adjust for fitting losses, (See 

### the comment and response ofWaterHeaterFittings above.} · ·



### Table D-5 ofthe DOETechnical Support Document provides performance values for a waterheater operating under the ANSI standby loss
test conditions for gas waterheaters. These values were used. simply to determine the additional insulation 

### that would be required to attain compliance with the DOE standards. In 

### GAMA's example, the 100-gallon gas waterheater required an additional two inches of insulation for compliance, bringing the total level to three inches. To estimate annual savings that would be realized with the additional two inches of insulation, performance calculations

were made for the 100-gallon water heatermodel, except that operating conditions were set to typical operation values, not the standy loss test values, i.e., room temperature was set to 72.5°F and water temperature was set fo 

### 140°F. Table E-1 ofthe DOETechnical Support Document indicates the expected savings that would result from the insulation increase. It 

### is unnecessary to try lo calculate savings from values in 

### Table D-5, 

### which were obtained under standby loss test conditions and not typical operating conditions. For an · insulation change from one to three inches. Table E-1 shows that annual savings will be $15.80. The simple payback is 4.64 years. This payback period remains well under the acceptable limit for Federal sector projects and within the Gfu'JA estimated five year life ofunits.**~** '

,**~** F. 

### ProposedAlternativeStandbyLoss Criteria

1. 

### General

GAMArecommended that DOE revise its 

### standards to exclude from the standbyloss criteria storage water heaters with more than 120-gallon storage capacity. The DOE standards exempt storage waterheaters and hot water storage tanks having morethan 500 

### gallons ofstorage capacity from the standby loss requirements 

### ifthe tank · surface area is thermally insulated to R

### 12.5 and ifa standing pilot light is not used. GAMA pointed out that its suggestion 

### of the 120-gallon limit was due to cmnmercial storage water heaters greater than 120-gallons being cusl.om

.built, as stated in the Preliminary Statement.



### DOEResponse: A 

### point of darification is necessary. In its Preliminary Statement, DOE acknowledges that many storage water heaters over 120 gallons are custom made. This is not to imply that DOE has data showing that all are custom made. DOE has no such data and neither GAMA nor the manufacturers have provided such data.

The Preliminary Statement indicates that many, but not all. commercial storage water heaters over 120 gallons

are custom made. Therefore,. to categorically exempt units over 120 gallons from the standby loss criteria could lead to potentiallyhigh levels of energy loss as a result oftheir use. DOE

. feels that it 

### is appropriate to continue 

### to apply the standby loss criteria, and the resulting testprocedures to units over 120 gallons 

### in size.

2. Instantaneous WaterWaters

GAMA 

### contended that DOE has redefined instantaneous water heaters in its standards by adding a maximum 10-gallon parameter. The DOE 

### standards define instantaneous waterheaters as devices w.ith an input rate.greater than 4,000

### Btu/hpergallon of

### water stored and less than 10

### gallons ofstorage capacity. They contend the definition immediately recategorizes a number of models that are presently considered instantaneous waterheaters as storage waterheaters and thus subjects those models to a standby loss criteria for the first time. Mr. 

### Stanonik ofGAMA 

### argued that DOE did not analyze the effect ofthe standby loss requirements

on these models. Without such analysis, the revised definition is notjustified and the standards should be revised to the
current industry definition of instantaneous waterheater, which'iS 

### "a
waterheaterhaving an input ofmore than 4,000 

### Btu/h pergallon ofstored water."

TomWutka ofCIGNA contended that DOE should use the ASHRAE/IES Standard 90.1-1989 water heating criteria. This standard uses a definition that defines a storage water heater as a waterheater that has an input rating of less than 4,000 Btu/hpergallonofstored water or a storage capacity of10gallons

### ·. Fedm:al Register 

## I Vol.:· 55; ·No.113, 

## l**Tu~sday;June"12,** 

### 1990 

## I Rules and 

### Regulations 23865

or more. It defines a non-storage water heater as a waterheater that has an input ratjng of at least 4,000 Btu/h per gallon ofstoredwater and a storage

capacity ofless than 10gailons.



### DOEResponse: DOE has evaluated the conflicting comments and concludes that the definitions in ASHRAE/IES Standard 90.1-1!)89 meet DOE's intent to 'separate the two categories ofwater heaters. Ithas been DOE'$ intent to separate instantaneous waterheaters from storage water heaters so that instantaneous waterheaters are limited
to "in-line'.' waterheating. The 10..gallon
cut offwas consciously established to eliminate any confusion over the definition of storage waterheater and instantaneous waterheaters, respectively. 

### IfDOE were to use the' de{inition ofwaterheaters having an input ofmore than 4,000 Btu/h per gallon of stored waterproposed by GAMA and State Industries, the new definition would shift many storage water heaters into the instantaneous category and exempt them from the corresponding standby loss criteria. This has never been DOE's intent and DOE has received no convincing justification for doing 

### so.



### In the Preliminarv Statement, the wording on page 49°727 

### of54 FR 49724 defined storage water heaters 

### as having

an input rating ofless than 4,000 Btu/h pergallon and a storage capacity of

more than 10 gallons. This raises the potential for confusion as shown in Table 2.

TABLE 2. DOE STATEMENT OF REASONS (11/30i89)

lnput Storage Capacity >-------"------ <4000 Bt11/h/gal Btu/h/gal

> 10 Gallons

.....:"·· Stornge: Water**lns""~ntaneous:** f!? Heater.· <10 Ga!iona .•.•..•...} Storage:???··········"'· 1nst2ntar.eotis: 

### rn

In its netvly published Standard 90.1- 1989, ASHRAE has defined the water heater categorfos as shovv'TI in Table 3

.. used the word "and" in the Preliminary Statement, thus causing the differences

seen inTables2 and 3.

DOE concludes that the ASHRAE proposal meets DOE's long term intention and avoids conflict with tbe
waterheater industry definition of "instantaneous water**.heater~'.** 3. Electric Water**H~aters.**

Four comments suggested revisions to the 1.9 w/ft2 standby loss requirements for commercial electric storage water heaters. Rheem Corporation and GAMA maintained that if DOE agrees to reference the tanks surface area, instead ofthejacket surface area, for placement 

### ofinsulation, DOE's goal oflowering

, standby loss becomes more feasible.

· They stated that the DOE standby loss

requirement of 1.9 W

### /ft2 is too low and should be modified upward, Also, they suggested that the requirementbe strudured to separate out losses that
cannot be reduced by adding insulation; such as those that,occur in smallerunits because ofhigher volume-to-surface

area relationships.

Their sugge'stion is as follo\vs:

SL<25 W

### +2.6 W

### /fi 2 cif tank**s~rfac~** area for waterheaters up to 120gallons

.. Equutjon 1.

Their comment stated that the 25 W
constant is the same as in the original standby loss requirement proposed 

### by DOE in 1984 [USDOE, 1984]. In light of the fact that DOE's 1.9 W

### /ft2 ofjacket surface area translates to about 3.2 W / 

### ft 2 oftank surface area, they pointed out that the suggested requirement is very close to DOE's requirements for two of the most popular sizes ofcommercial

. electricstorage water heiJ.ters. ·

DOE also received 

## two comments and detailed backgro11nd materfal from Dr. Golqstein ofNRDG**mairitain~ng** .that the.
j .9 W/

### ft2 requirement was too high, 

### Dr. GoldsteiI). arg1rnd that.DOE had

. prmi!dedsufficient technical 1malysis to support a 1.s2

## wIft 2 standby loss level.

Dr. Goldstein also contended that the DOE Technical Suppcrt Document demonstrates that increasing insulation beyond the levels required to mest the DOE standby loss criteria are cost**t~ffective,** and should not be reduced.

Dr. Goldstein maintained the following: that Table C-1 ofthe Technical Support**~~·'"'u'""""** insulation to a last increment ofinsulation from 3¥.a inches to 4 inches. This ranges from 7.1 years for the 120-gallon units to 3.8years for the 50cgallon units. Assuming a 12- year life for the water heater, the payback period ofless than 8.9 years is cost-effective at real discount rates of five percent or less. Since energy.supply
costs are typically evaluated at discount
rates oftwo percent to four percent, a five percent rate is conservatively high, pro-ving cost-effectiveness. The results

are so striking that for two ofthe three sizes analyzed by DOE, the payback periods would apply cost-effectiveness

even at a seven percent real discount rate. Thus, taken from an incremental

.cost-effectiveness point-of-view, four inches ofinsulation, corresponding to a standby loss of about 1.52 W/ft2

, is the economic optimum point for the building

owner. Dr. Goldstein concluded that a requirement for the maximum improvementin efficiency that is economfoally practicable can ask no less than the level ofefficiency represented by the minimum life cycle cost point.

Dr. Goldstein stressed that DOE must revise its standards to agree with the



### newcalculations.



### DOEResponse: Based on the public·
comment and other information received, DOE has decided to amend its criteria for commercial electric storage 

### water heaters.

At 

### a February 11, 1990, meeting 

### of the Service Water Heating Subcommittee of SSPC 90R, GAMA presented a handout that proposed a revised requirement for standby losses for electric water heaters. The equation presented was:
SL<25:W

### +1.6W/ft2 ofexternal jacketarea Equatlo1"1 2.

. Note that this equation is for external. or jacket surface area, while the recommendation to DOE pertaiqs to tank surface area and uses 2.6W/ft2 •

To calculate the standbv loss criteria in Watts using this

### equati~n, one would have to multiply 

### !he area of the water heaterjacket by 1.6 and then add 25 Watts. To calculate the criteria in Watts/ft2 ofexternal surface are·a, one would divide 25 bv the tank's external surface area and

### ~dd 1.6 W/ft2 •

To compare both ofthe above standby loss equations with 

### th.a current 4 oftank a:;ea and the '1.9 of

## 23866 Federal Register / Vol. 55; No. 113 / 

### Tuesday, June .12, 1990 / 

### Rules and Regulations

Table 4

- Comparison ot Proposed GAMA Standby Losa Criteria tor Electric Water Heaters

Volume fGJ At I tt2l Aj (!t2) Eq. 1 SL (W! Eq. 2 SL (WJ (baaed on tank)

50-52 20-23

60-85**26~32**

1:'0 38-41



### To further compare Equations 1 and 2, DOE looked at the criteria values that would apply to sample tanks of50-, 60- and 120-gallon storage capacities. The (baaed on jacket)

35-39 61.0-87.4

44-45 95.4-97.0

54 111.4



### insulation thickness on these tanks were varied to determine when, in terms of standby loss in total Watts, the equations would be equivalent. Table 5 77.0-84.8

97.8-108.2

123.8-131.6



### shows the insulation levels near which the two equations become equivalent for the sample waterheaters.

Table 5

- Comparison of Criteria tor Sample Electric Water Heaters

TYPE HEIGHT DIAMETER GALLONS INS TANK AREA J. AREA GAMA l GA.'!A 2 (ft) (ft) (in) (ft2 ) (ft2 ) (W@ 1.6)(\11@ 2.6)

ELEC ELEC

ELEC ELEC

ELEC ELEC 3.06
3.06

4.05 4.05

4.35
4.35



### DOE agrees with the comment that a revision in the standby loss criteria to reference tank surface area versus jacket surface area is appropriate. DOE's current analysis considers losses that cannot_:becontrolled by the addition ofinsulation to the tank. Including these losses in the totalloss figure still allows for the calculation of a meaningful W/ft2 

### figure ofmerit for the particular waterheater. However, the
comment is incorrect in stating that the 1.9 W

### /ft2 

### ofjacket area translates to 3.2 W/ft2 

### oftank area is incorrect. Actually the conversion between the jacket and tank is shown in Table 5.

DOE has conducted additional analysis toanalyze the opposing requests and several othercomments received, such as the effect ofusing a waterheaterjacketemissivity of0.5

versus 0,9.

-

DOEfinds that 3W/ft 2

### is a practjcable standby lossc.riteria for its electric storage waterheatel'S ofthe size and input ranges discussed in tl}is

.. . Response andAmwuncement and. has adopted it 

### asJts new c.ornrnercial

. 1.67
1.67

1.83
1.83 50.00
50.00

80.00
80.00 3.00 3.50

3.50 4.00 20.43
20.43

28.54
28.54 31.67 33.77

44.26 46.79 75.67 79.03

95.84
99.66 78.13
78.13

99.22
99.22

2.17 120.00
2.17 120.00 4.50 5.00 37.05
37.05 60.16 121.20 121.33 63.07**125~92** 121.33



### electric storage waterheater standby loss level.

Table 6was created to compare the

new criteria for electric waterheaters with existing DOE**criteria,jacke~** 

### · surface areaversus tank surface area, the

### ANSI/ASHRAE/IES Standard90A1080, tne GAMA proposal. the NRDC proposal,.and the test.data collected by NIST. The table.is confined to those sizes ofcommercial electric water heaters that predominate the industry,

as stated by GAMA and the commenting manufacturers-50, 80, 120 gallons.

The DOE Interim Standards require a standby loss level ofno more than 1.9 W/ft2 • 

### In comparison, the currently produced 50-gallon unit tested by NIST had 3.06 W/ft 2 

### standby loss ofjacket surface area. Whenmodified by additional insulation, the NIST test unit performed with

# a2.47 W/ft 2 

### standby loss. Neither the currently produced unit

nor the.modified unit would meet the DOE standards.· · · ·

Both GAMA and ASHRAE suggested
to DOEthat referencing tank surface area would produce a more practical criteria. DOE has agreed. The tank surface area equivalent to the. current DOE criteria translates into 2.95 W/ft 2 

### for a 50-gaUon model, 2.78 W/ft2 

### for an 80-gallon model, and 2.66 W/ft 2 

### for a 120-gallon model. The NIST 50-gallon
test unit showed a tank surface area equivalent of4.06 W/ft 2

### unmodified and

a 3.29 W/fi2 

### modified with additional insulation. Again neither would meet a tank surface area equivalent of the currerit 

### DOE standby loss criteria. However, these units would meet the
current ASHRAE criteria set in 1980 of4 

## WIft2 

### oftank surface area.

The GAMA proposal discussed above, translates into a standby loss criteria level of 3.82 W/ft 2 

### oftank surface area for 50-gallon units, 3.47 W/ft2

### for 80- gallon units, and 3.27 W/ft2

### for 120- gallon units. These all would be lower than the current ASHRAE levels set in 1980 but orily W 

### to 18 percent lower:The DOEanalysisindicatesthat at least a 25 percent reduction is practical and costeffective.

- ·

### Federal Register 

## l Vol. 55, No. 113 

## I Tuesday, Ju'ne 12, 

### 1990 

## I Rules and 

### Regulations 

### 23867

The NRDC proposal suggests that a 1.52 W

### /ft2 ofjacket surface area is practicaLaccordingto DOE's analysis in the Preliminary Statement. Dr. Goldstein is correct in his assessment, however, DOE believes its estimates were optimistic for a standby loss criteria**r~Jer·encing** jacket surface area. Tnerefore, DOE is not inclined to reduce the standbyloss criteria any further.

As such DOE has set its standby loss criteria level for electric storage water heaters at 3.0 W

### /ft 2 oftank surface area for all size units. This represent?! a 25 percent reduction in current standards. Itmeans that units built with 2.75 to 3 inches offoam insulation surrmmding the tank and R-8 fiberglass on the conti:ols, or 6.5 inches 

### offiberglass surrounding tank and controls, 

### will meet the criteria. It

### will also mean that the larger units will have an easier time meeting the criteria because oftheir larger tank volume to surface ratio, as indicatedby item two in table 6.

Table 6

- Comparison o! Standby Loss Criteria

Nominal Tank Capacity Alternative cr-1ter1a 50 Gal 80 Gal 120 Gal

DOE Statement cf Reasons [W/ft2 of jacket area] NIST tents [modified/with blanket] 1.9 1.9 1.9

p.06/2.47j

DOE estimated tank equivalent of the

jacket area [W/ft2 of tank area] NIST tests [modified/with blanket) 2.95 2.• 78 2.66

[4.06/3.29]

DOE estimated percent loss equivalent [percent of stored energy per hour] NIST tests [modified/with blanket] 0.530 0.520 O.t30

f0.99/0.77]

ANSI/ASBR.1\.E/IES Standard 90A-1980

and 90-1975 [W/ft2 of_.tank llrea] 4.0

GAMA**p~opcsal** [converted to

W/!t cf tank surface area) 3.82

NRDC pr9posal 1.52 1.52

(W/ft" of tanll area]

DOE acknowledges t1ie support for its e"isting criteria and the recommendation to extend it futther. However, DOE observes that the original analysis did not include the losses from fittings and controls, thus overstating the benefits of adding insulation. Itis 

### aiso noted that no manufacturer currently produces a model which has been tested and found
to meet the current standby loss criteria.

The argument of a 12-year life for commercial waterheaters may not be valid in light ofcontentions about the life 

### ofwater heaters made by the manufacturers. Until more definitive data become available, DOE believes it is appropriate to use its more conservative analysis.

4. Gas WaterHeaters

Rheem Corporation and GM4A suggested revisions to the categorization ofgas storage waterheaters. They suggested that DOE separate gas storage waterheaters into two categories- <155,000 Btu/h and>155,000 Btu-so that manufacturers ofwater heater modeis not currently equipped with flue dampers and IIDs, generally those 155,000 Btu/hand lower, do not have to add them 

### to meet the DOE standards. The lowerrequirement for the higher input models recognizes 

### that these models already are equipped with**flm~** dampers and IIDs. 

### The suggested requirements are as foilows: Inpuh;;155,000 Btu/h is SL.;:1.3+120iV; and Equation .'J. Input>155,000 Btu/his SL;,;1.3+100/V. Equotjon 4.

GAMA further proposed an exception
to the basic formula for maximum allowable standby loss. Mr. Stanonik contended that flue dampers and IIDs

are not cost effective on commercial gas storage waterheaters wifa inputs up to approximately 200,0C"() Btu/h and that 12 percent or less ofwater heaters sold have storage vessels greater than 120 gallons. Mr. Stanonik proposed the 4.0

3.27

1.52

following exceptions: for gas water heaters having an input rating not.over 200,000 

### Btu/h and not requiring 

### an external power.source, the standby loss in percent perhour shall not exceed 1.3 

## + 368/V; for all types of storage water heaters-gas, electric, and oil-with capacities greater than 120 gallons, they shall be insulated to limit heat loss to 605 Btu/h/ft 2 of

### tank surface area. ·



### DOEResponse:DOE appreciates the suggestions for alternate criteria. DOE notes, however, that the commenter did
not include documentation to support the proposed criteria. Testdata supplied by the CEC shows several units that currently meet DOE's standby loss criteria, 

### One ofthe manufacturers of those units supports the standbyloss criteria at its current level. While there

was a following letterqualifying these comments, DOE found it unpersuasive. Additional units tested by CEC indicate compliance with the ASHRAE 90A-1980 standard without flue dampers and IIDs. Estimates of the benefits offlue**damper~**

### 23868 

### Federal Register / Vol. 55, 

### No. 113 

## I Tuesday, June 12, 

### 1990 

## f Rules and Regulations

and IIDs applied to these units indicate that all would comply with the current DOE criteria. DOE feels that it has promulgateCI criteria which is reasonable, cost-effective, and can be
met with current technology and manufacturing practices.



### V. Conclusions 

### a.."ld Appropriate Standby Loss Criteria

The following is a discussion ofthe conclusions reached by DOE in connection with this announcement of 

### final storage water heater standby loss criteria and the reasons for its decisions. DOE's decisions are based on its consideration ofthe comments received, additional computer modeling, and the
tests conducted by NIST on an electric
waterheater and a gas waterheater.

As stated in Section III, the water heaters included in this Response and Announcement are limited to the following: (i) Electric storage water heaters ofgreater than 120-gallon capacity or ofgreater than 12kW input rating; (ii) gas storage waterheaters of greater than 100-gallon capacity or greater than 75,000 Btu per hour input rate; and (iii) oil-fired storage water heaters 

### ofgreater than 50-gallon capacity and greater than 105,000 Btu perhour input rate. Storage water heaters having more 

### than 500 gallons of storage capacity are excluded 

### ifthe tank surface area is thermally insulated to R-12.5 and a standing pilot light is not used. At issue are the standby loss criteria set by DOE 

### for these water heaters, which some have contended are too high ortoo low. A second issue is the difference between storage and instantaneous waterheaters. The specific q11estion is whether to include high power waterheaters in the category ofinstantaneous water heaters and, therefore, eliminate standby loss requirements for these units. The purpose ofthis Section is to discuss the appropriate standby loss criteria and the bases for DOE's determination.

In addition, the DOE Interim Standards reference recognized test procedures 

### to determine waterheater standby loss. 

### The referenced test procedures were developed by ANSI and DOE. The reliability ofthe test procedures is not in question at this time, although recommendations have been made 

### to DOE to consider recognizing updated test procedures for commercial electric storage water heaters.

With due consideration ofthe
comments that have been received and the results offurther tests and analyses thatDOE has caused to be conducted, andin accordance with the remand procedure provided for in the Court's October 6, 1989, Memorandum and Order, DOE is announcing and adopting the water heater standby loss criteria
set forth in Table 9.3-1 below (part 435 ofchapterII oftitle 10 ofthe 

### Code of FederalRegulations subpart A, § 435.109, Table 9.3-1, Standard Rating Conditions and Minimum Performance ofWaterHeating Equipment).

PART 435-ENERGY CONSERVATION 

### VOLUNTARY PERFORMANCE STANDARDS FOR NEW BUILDINGS; 

### MANDATORY FOR FEDERAL BUILDINGS

1.The authority 

### for part 435 continues
to read as follows:

Authority: Energy Conservation Standards for New Buildings Act of 1976, as amended, (42 U.S.C. 6831-6870), enacted as Title Ill of the Energy Conservation and Production Act; (42 U.S.C. 8201, etseq.): (42 U.S.C. 8255); section 545, Natiohal Energy Conservation Policy Act; Department ofEnergy Organization Act, (42 U.S.C. 7101 et seq.)
§ 435.109 [Amended]

2. In § 435.109, Table 9.3-1 is**1·e~;ised** to read as follows:

BILLING CODE 6450-01-!'AWater**Heat~rs** 

### Federal Register 

## I Vol. $5, No, 113 

## I Tuesday, 

## June 12, 1990 

## I Rules 

### and Regulations'

Table 9.3-1 (Revised June 12, 1990) Standard Rating Conditions &**Mini~um** Performance of Water Heating Equipment



# I I jElectric! Storage Input capacity Rating

(Gal)

!,120 5._12 kW Applicable**Te~t** Procedure Minimum Performance

DOE Fating Eft.

DOE**T~st** Procedures, 1985 Code of Federal**Re~ula** tiona Title 10, Part 430 

## I I**~o.9s-o.oon2v**

1 1,i 

# 1----,0-+-)1'-1------------t------.....+---+------1

>120 >12kW DOE Test Procedures! 1990

- - SL Code of Federal Regulat tions Title 10, Part 430

- - <3.0 W/ft2**i------r--~~~~i~~~~-t-~~~~-~-~~~~~-t-~~~~-~~-1-~~-t-~~~--1** !100 ;:::75,000 :atu/h Gas 

# I DOE Tast Proceclures, 1985
Code of Federal Regulations Title 10, Part 430 EF

;:,0.62-0.0019\7 

# l I**r·~->-10-'0-l~o-r_)_>_7_5_,_0_0_G-+-Al-~-G-l_Z_2_l** ___**l_0-.-3--1-9-S-~~--~--+l~-~~-~~+--E-t__,.l.~~S-L~""1** 

# l Btu/!! Ga"' Watsr Beate:r·s I

.

## ~ 

# l

l 

## Ii

# ~~,. 'O·" ' 

### •I"'""''-' '"

. "" •.,,,, 

## I

- "'

# <;;~ I cu 

# I**~** 

# -'-'

,. DOl!: Test Proc'1!<irnres, 1%5

# 1--~:i'' - 

# I I a;:i.;/ll Code of FsC.eral 11.sgula- 

# I

. . I**~so ~1os,ooo**  rrtu/h

>105,000
l!tu/h ticns Title 10, Part 430 I**~{L59-0.()0J.9V** - -

SL

<l..J+ 

### 23869

### 23870 

### Federal Register/ Vol. 55, No. 113 /Tuesday, June 12, 1990 

## I Rules and Regulations

Table 9.3-1 (Revised June 12, 1990) Standard Rating Condition.a & Minimum Performance of Water !!111ating Equipment (Cont.)

Type Applicable Test Procadure Input Class F!l'el Capacity Rating

Unfired 1 All All Storage Volume Inputs

Non-Storage2 Gas


# - All ANSI Z21.10.3-19B4 W<iter Heaters Inputs

Distill All

OU


# - Inputs

Pool Gas/ All ANSI Z21.56-1986 Heatera OU



# - Inputs

Rotes tor Table 9.3-1: Terms Defined: 1. EF" Energy factor, overall heater efficiency by DOI TestProceduro Et " Thermal efficiency with 70°F, •T Minimum Performance



# - HL



# - <6.S Btu/il"ft2

"t 

# -

BO' 

# -

Ee 

# -

83\


# -

Et. 

# -

78\0



# -

Ee • Combustion cfficienc2' 100 percent

- flue lose when smoke • 0 {trace is permitted) SL• Standby loss in W/ft based on 

### ao•F, AT, or in percent per hour based on nominal 

### so•v, •T
HL • Heat loaa of tank.surface area V • Storage volume in gallons 2. A non-storage water heater is a device with an input rate-greater than 4000 Btu/h/gallon ot water ®tored or less than 10 gallons of storage capacity. A atorage water heater is a water heater that has

an input rating of less than 4000 Btu/h per gallon of atorred water or a storage capacity of less than 10 gallona •

### Federal Register 

## I Vol. 55, No. 113 

## I Tuesday, June 12, 1990 

## l Rules and Regulations 23871

A. 

### Instantaneous WaterHeaters

DOE has determined that the definition

# of instantaneous water heaters used'in the January 30, 

### t989, DOE Interim Standards and the definition used in the November 30, 

### 1989, Preliminary Statement, should be modified to match the definition utilized by ASHRAE/IES Standard 90.1-1989.

GAMA contended that DOE had changed an accepted definition of instantaneous waterheaters by adding a maximum ten-gallon parameter to devices with an input rate greater than 4000 

### Btu/h per gallon ofwater stored and subjecting the remaining models 

## ( >10-gallons and 

## >4,000 

### Btu/hper gallon) to a standby loss criteria for the first time. As previously indicated, if DOE were to use the industrydefinition ofwaterheaters having an input ofmore than 4,000 

### Btu/h pergallon ofstored water, the new definition would add many storagewaterheaters into the instantaneouscategory and exempt them from the corresponding standby loss criteria. It

### has been DOE's intent to 

### separate instantaneous waterheaters from storage waterheaters so that instantaneous waterheaters are limited to "in-line" water heating. The 10-gallon cut-offwas established to:eliminate any confusion over the definition DOE has chosen to use. The DOE standards now
cover instantaneous waterheaters with separate storage tanks. In the future, DOE will 

### use the same definition found. in ASHRAE/IES Standard 90.1-1989. This definitionis included in Table 9.3-1 

### (revised June 12, 1990).

B. Electric T11aterHeaters



### 1. Test Procedures

In 

### its January 30, 1989 Interim Standards, DOE listed ANSI Standard C72.1-1972, American National Standard for Household Automatic Electric Storage-Type Water Heaters, as test procedures for establishing standby loss performance. DOE has subsequently learned that the ANSI test procedure is no longer supported by A.."JSI. Accordingly, in the future. DOE will 

### require that all tests be conducted in accordance with DOE's test procedure for electric waterheaters. {10 CFR part 430, January 1, 1990.) This test procedure requires a test setup similar
to what will be required ofthe piping around the unit in actual conditions, including insulated heat trap and inlet and outlet piping. The DOE test procedure is well understood by manufacturers and testing laboratories and is widely recognized in the building industry. 2. Tank Surface Area vs. Jacket Surface Area

In 

### addition to the suggestions to revise the 1.9 

### W/ft 2 

### standby loss requirement for commercial electric storage water heaters, several comments suggested that DOE 

### express its criteria in terms of tank surface area, instead ofthejacket surface area. ASHRAE indicated that it

, 

### had clarified its criteria as pertaining to tank surface area. DOE initially used the jacket surface area because that is what

was required by the now unsupported ANSI 

### test procedure. Industry
commenters suggested that DOE's requirement of 1.9 W/ft2 

### ofjacket surface area translates to about 3.2 

## WIft 2 

### oftank surface area or what was termed very close to 

### DOE's requirements for two ofthe most popular sizes ofcommercial electric storage waterheaters.

DOE 

### agrees with the comments and in 

### its announced criteria expressed its requirements in 

### terms oftank surface

area instead ofjacket surface area. DOE 

### believes that criteria expressed in terms 

### oftank surface area is more often used and that it 

### will help to avoid confusion ofspecification "rriters between the DOE criteria and that adopted by ASHRAE. Table 6 shows specific examples of the numerical-differences between tank andjacket surface area for waterheaters that would meetthe DOE 

### standby loss criteria,:.
3. Watts/ft 2 

### vs. Percent ofStored Energy

The industry uses criterion for gas storage water heater standby loss expressed in percent stored energy loss perhour. The appropriateness ofusing a standby loss expressed in terms of stored energy loss is attributable to the fact that the precise temperature ofthe test room is no longer critical to the results. In addition, as the calculation is done in terms oftank volume, it 

### is easy to measure that volume. One fills the tank, measuring the amount supplied, or, if

### capable ofbeing fully emptied, empties it, 

### and measures the volume of the contents emptied. This would also have the advantage ofexpressing the standby loss for all "commercial size" water heaters in the same terms. Finallv, both manufacturers and testing • laboratories are familiar with standbv loss being expressed in these terms a'Ild those who test units are already set up to do these measurements.

It

### has been recommended that DOE express the standby loss for electric
waterheaters in terms ofpercent of stored energy loss per hour. DOE has determined not to do so at this time, as additional information is needed on the implications ofsucha decision. During the remainder of

### the demonstration period for the DOE Interim Standards, DOE will continue to evaluate the desirability andeffects ofchanging the· electric storage waterheater criterion from criterion expressed in lank 

### surface

area to criterion expressed in 

### percent perhour. How.ever, for purposes ofthis publication, DOE's electric storage water heater criterion is 

### expressed in 

### terms oftank surface area and any subsequent change ofthis standard would need to bejustified on the basis ofthe statutory guidelines, including energy efficiency, economic cost and benefit, and impact on affected groups. In 

### the event DOE is considering a change ofthis nature in connection with 

### the forthcoming issuance offinal standards, it 

### will so indicate in the Notice ofProposed Rulemaking at that 

### tLrne and request comment on the feasibility or appropriateness of such a change.

4. 

### Establishment ofDOE Criteria

DOE received comment from GAMA and three waterheater manufacturers indicating that the DOE standby loss requirement of 1.9 W/ft 2 

### is too low and should be modified upward. They suggested thatthe requirement be**~** 

### restructured to separate out losses that cannot be reduced by adding insulation, such as those that occur in smaller unitsbecause ofhigher volume-to-surface

area relationships.

Their suggestion is contained in Equation 1, repeated below:
SL = <25 W 

## + 2.6 

### W /ft 2 ofthe tank surface

area for water heaters up to 120 gallons Equation 1.



### Dr. Goldstein ofNRDC maintained that the L9 W/ft 2 

### requirement is too high. He argued that DOE had provided sufficient technical analysis to support a 1.52 W/ft 2 

### standby loss level.

DOE has conducted additional analysis ofopposing views and several other comments received,_such as the effect ofusing a waterheaterjacket emissivityof0.5 versus 0.9. DOE finds that 3 W/ft 2 

### is a practicable and costeffective standby loss criterion for electric storage water heaters ofthe size and input ranges discussed in this Response and Announcement and adopts it 

### as DOE's new commercial electric storage water heater standby loss criterion.

DOE bases this decision on tests of a storage water heater, additional information developed on otherlosses, such as fittings and controls, excellent correlation oftest and model results, and a new cost benefit analysis. Figure 6

### 23872 

### Federal Register 

## I Vol. 55, No. 113 / Tuesday, 

### June 12, 1990 

## I Rules 

### and Regulations

presents the analysis ofa 50, 80, 120 and
170gallon capacity electric storage waterheaters, respectively, for a range 

### ofinsulation thicknesses up to 7 inches. Tables 8, 9, 10, and 11 provide the data

on which Figure 6 wasbased.

131LLING CODE 6450--01-M

### Federal Register 

## I Vol. 55, No. 113 

## I Tuesday, June 12, 1990 

## I Rules and Regulations 

### 23873



# ELECTRIC WATER HEATER STANDBY LOSSES Emissivity=.9, 40% Other Loss Reduct.ion

,.......,**~ 5-+-,-:..-~----~--~-----~---~·------;**  0 1- 

## J_ 4.5



# .... g**4-1--~->.,,.------~--------------------l** '.,

### ~ 

### 3.5**+---i'i~c-=----------**
Ill 

### fj 

### 3

# +--------

-l**£2,5+--------~::....,-~~.------=--=="llB-----~~---==----~~** "'tl 

### c 

## 2**2t---~~~~~~-""'-~:§:::~F=:;;::=::'.:==-+---=r==F~** VJ 

### 1.5 I 

### LO 1.5 2.0 2.5 3.0 3.5 4,0 4.5 5.0 5.5 6.0 6.5 7.0 Insulation Thickness 

### (in.)

Galion -+- 

### 85



### Figure 6 - Analysis of Electric Water Heaters

- 50, 80, 120 

## & 170 gallon capacity**2387~** 

### Federal Register / Vol. 55, 

### No. 113 / 

### Tuesday, June 12, 1990 / Rules and Regulations

Table 8



### ELfCTRIC STANDBY LOSS CALCULATIONS BASED ON TANK LOSSES CORRECTED TO 80 DEGREES DELTA T

50 

### GALLON 21.67 

### SQ FT-TANK ELECTRIC WATER HEATER**7':>.~** FOAM, 25% 

### GLASS 0.9 

### EMISSlVIT 40% REDUCTiON OF OTHER LOSSES

J

### NSUL Q

### TOP Q

### SIDE Q 

### BOT Q

### JACKET Q

### OTHR Q 

### TOfAL Q

### TOTAL SL (Btu/h) (Btu/h) (Btu/h) (Btu/h) (Btu/h) (Btu/h) (Watts) (w/sq ft)

0.0 286.33 2815.33 2i7.09 3318.75 60.51 3379.26 990 .11 47. 72 0.5 39.67 455. 34 38.13 533 .14 60.51 593.65 173.94 8.38 1. 0 23.90 270.10 23.40 317.40 60. 51 377.91 110. 73 5.34 1. 5 18 .15 199 .19 17 .89 235.23 60.51 295.74 86.65 4.18 2.0 15.21 163.22 15.05 193.48 60.51 253.99 74.42 3.59 2.5 13.46 141.15 13.35 167.96 60.51 228.47 66.94 3.23 3.0 12.32 126.32 12.24 150. 88 60.5i 211.39 61.94 2.99

? " "·**~** 11. 54 115.74 11. 47 138.75 60.51 199.26 58.33 2.81 4.0 10.98 107.87 10.92 129.77 60.51 190.28 55.75 2.59 4.5 10.57 101.84 10.53 122.94 60.51 183.45 53.75 2.59 5.0 10.27 97.09 10.23 117.59 60.51 178 .10 52 .18 2.51 5.5 10.05 93.30 10.01 113.36 60.51 173.87 50.94 2.46 6.0 9.89 90.23 9.86 109.98 60.51 170.49 49.95 2.41 6.5 9.77 87 .82 9.74 107.33 60.51 167.84 49.18 2.37 7.0 9.69 85.64 9.66 104.99 60.51 165.50 48.49 2.34



### STANDBY LOSS ADJUSTED TO 80 

### DEG DELTA T



### 82 CE698 I6.CI.N

### Federal Register/ Vo[_

### 55, No. 113 

## I Tuesday, June 12, 1990 

## I Rules 

### and Regulations 23875



### Tab1e'9

ELECTRIC WATER HEATER 85 

### GALLON 29.91 

### SQ FT-TANK 75% FOAM. 25% 

### GLASS 0.9 

### EMISS!VIT 40% 

### REDUCTION OF 

### urnrn LOSSES

INSUL Q TOP 

### QSIDE QBOT QJACKET QOTHR Q 

### TOTAL Q 

### TOTAL SL 

### (Btu/h) (Btu/h) (Btu/h) (Btu/h) (Btu/h) (Btu/h) (Watts) (Iii/sq ft)**=~====================================~===;=================-=============** 0.0 449.93 3761.66 344.51 4556.10 60.51 4616.61 1352.65 47.23 0.5 62.45 601. 35 60.07 723.87 60.51 784.38 229.82 8.02 1.0 36.90 352.66 36.14 425.70 60.51 486.21 142.46 4.97 1.5 27.51 257.30 27 .13 311.94 60.51 372.45 109.13 3.81 2.0 22.67 208.83 22.43 253.93 60.51 314.44 92 .13 3.22 2.5 19.74 178.99 19.58 218.31 60.51 278.82 81.69 2.-85 3.0

. 17. 80. 158.87 17.68 194 35 60.51 254.86 74.67 2.61 3.5 16.44 144.46 16.35 177.25 60.51 237.76 69.65 2.43 4.0 15.45 133.67 15.37 164.49 60.51 225.·00 65.92 2.30 4.5 14.70 125.35 14.64 154.69 60.51 215.20 63.05 2.20 5.0 14 .13 118. 77 14.07 146.97 60.51 207.48 60.79 2.12 5.5 13.68 113.46 13.63 140.77 60.51 201.28 58.97 2.06 6. (} 13.33 109 .12 13.29 135.74 60.51 196.25 57.50 2.01 6.5 13.05 105.53 13.01 131.59 60.51 192.10 56.28 1.97 7.0 12.83 102.53 12.80 128 .16 60.51 188.{)7 55.28 1.93



### Table 10

ELECTRIC WATER HEATER 120 GALLON 39.50 SQ FT-TANK 75% FOAM, 25% GLASS 0.9 EMISSIVIT 40% REDUCTION OF OTHER LOSSES

rNSUL Q TOP Q

### SIDE QBOT 

### QJACKET QOTHR QTOTAL Q TOTAL SL 

### (Btu/h

### l (Btu/h) (Btu/h) (Btu/h) (Btu/h) {Btu/h) (Watts.) {II/sq ft)**===========~======================;;.;:===================:=================** 0.0 607.16 4957.48 447.94 6012.58 60.51 6073.09 1779.40 47.05 0.5 80.98 788.21 77 .93 947 .12 60.51 1007.63 295.23 7.81 1. 0 47.41 458. 86 46.45 552.72 60.51 613.23 179.67 4.75 1. 5 35.03. 334.53 34.55 404' 11 60.51 464.62 136.13 3.60 2.0 28.61 269.23 28.32 326.16 60.51 386.67 113. 29 3.00 2.5 24. 72 228.23 24.52 277.47 60.51 337.98 93.03 2.62 3.0 22 .13 201. 41 21.98 245.52 60.51 306. 03 89.67 2.37 3.5 20.30 182 .11 20.18 222.59 60.51 283 .10 82.95 2.19 4.0 18.95 167.52 18.85 205.42 60.51 265. 93 77 .92 2.06 4.5 17.92 !56.39 17 .84 192 .15 60.51 252.56 74.03 1.96 5.0 17 .12 147.47 17.05 181. 64 60.51 242 .15 70.95 1.88 5.5 16.48 140.24 16.43 173 .15 60.51 233.66 68.46 1.81 6.0 15.98 134.29 15. 93 166.20 60.51 226.71 66.43 l.76 6.5 15.57 129.32 15.52 160.41 60.51 220.92 64.73 1. 71 7.0 15.24 125 .14 15.20 155.58 60.51 216.09 63.31 1.67

STANDBY LOSS ADJUSTED TO 80 DEG DELTA T



### 83 CE698 I6.CLlf

### ; 23876 ; 

### Federal Register;/ 

### Vol. 55_,No. 113 

# l Tuesday, June·12, 

### 1990/1 Rules and 

### Regula:tio)'.1$

, ·

Table 11

ELECTRIC WATER HEATER 

### 170 GALLON 

### 51. 84 SQ FT-TANK 

### 75% FOAM,. 

### 25% GLASS 0.$ EM!SSIVIT 

### 40% REDUCTION OF OTHER LOSSES
IN$UL Q TOP Q SIDE Q BOT .Q JACKET 

### QOTHR 

### Q**TOT~L** Q TOTAL : SL (Btu/h) .(!1-tu/h). (Btu/h) (Btu/h) (Btu/h} (Btu/h) (Watts) (W/sq ft) 

## ::=======================================================================

0.0 537.836914:44 398.60 7850.87 60.51 7911. 38 2318.01 46.70 0.5 72.13 1102.86 69.41 1244.40 60.51 1304.91 382.34 

### 7.70 1.

### 0 42.40 640.35 41. 53 724.28 60.51 784.79 229.94 4.63 1.

### 5 31.45 465.43 31.01 527.89 60.51 588.40 172.40 3.47 2.0**~25.**

### 78 373.42 25.52 424.72 60.51 485.23 142 .17 2.86 2.5 22.36 316.74 22.17 361.27 60.51 421.78 123.58 2.49 3.0 20.08 278.40 19.94 318.42 60. 51 378.93 111. 03 2.24 3.5 18.47 250

..81 l&.36 

### 287.64 60.51 348.15 102.01 2.06 4.0 17 .29 230.05 17.20 264.54 60.51 325.05 95.24 1.92 4.5 16.39 213.91 16.32 246.62 60.51 307 .13 89.99 1.81 5.0 15.70 201. 03 15.64 232.37 60.51 292.88 85.81 1.

### 73 5.'S 15.16 190.55 15.10 2,20 .81 60.51 281.32 82.43 1.66 6.0 14.73 181. 89 14.68 211. 30 60.51 271.81 79.64 1.60 6.5 14.38 174.62 14.'34 203.34 60.51 263.85 77 .31 1. 56 7.0 14.10 168.46 14.07 196.·63 60.51 257 .14 75.34 1.52

OilllNG CODE 6450-01-C

### Federal Register 

## I Vol. 55, No. 113 / 

### Tuesday, June 12, 1990 

## l Rules m:i.d 

### Regulations

. 23877·

C. Gas WaterHeaters

As noted above, DOE 

### received two comments suggesting revisions to the categorization ofgas storage water lleaters. It 

### was suggested that the categories be changed to 

### <:;155,000 Btu/h and 

## >155,000Btu/h so 

### that manufacturers ofwaterheatermodels
not currently equipped with flue dampers and IIDs, generally those 

## >155,000

### Blu/h, would not 

### have to add them 

### to**m~et** the DOE 

### standards. The January 30, 

### 1989, DOE standards 

### require fuat gas storage waterheaters with an input rating ofless than 75,000 Btu/h
must meet the standby loss criterion 

### of <1.3+38/V. The two comments suggested that units 

### with an input rating of 155,000 Btu/h orgreater are already equipped with flue dampers and HDs,



### DOE has not received sufficient information to warrant adopting the suggestion. Rather it

### believes that units ofover 75,00Cl Btu/h are high input models that should be equipped with flue dampers and !IDs to limit energy waste. DOE further believes that the use ofthese high input-low storage units is contraryto good building design in many cases and most certain!v is counterproductive to good**en~rgy** 

### conservati.on practice. Units with high demand and low storage are only properly used when health codes or otherpractical reasons require ondemand hot water. Even then a booster heater should be used. Too often the ·units are used so as not to cause complaints about not enough hot water. In many cases, this type ofcautionary procedure causes over-design and wastes energy.

DOE also does not find any persuasive argument that the addition of flue dampers and IIDs will 

### add significant production costs. The industry acknowledges that it 

### is already building units that have such features.

The two comments also suggested the following requirements: Input <155,000 Btu/h requires 11 

### SL.;:1.3+120/ 

## v Input 

### >155,000 Btu/h requires a SL<:;l.3+100/V
The January 30, 1989, DOE Interim Standards reouire that units ofless than

or equal to 10.0 

### gallons ofnominal storage capacity and/orpossess an tanktop and sides; In

### Table 13, the input rating 

### ofless than orequal to figerglass was replaced by 

### k = 0.1667 

### 75,000 Btu/h must meet an overall. Btu•in/h•f(2

### •'°Ffoam atR-12 for 2 ·

-energy factor. Units ofgreater than 100 inches; Nd insulation was factored for gallons ofnominal storage capacity the bot!om. This is 

### consistent with the and/or greater than 75,000 Btu/h 

### inrmt previous analysis performed 

### for the rating must meeta standby loss · Statementof

### Reasons. The 

### "Q ADD" 

### criterion of <1.3+38/V. factor was adjusted until the standby 

### D. Gas 

### WaterHeater

### Analysis loss matched that reported by NIST on the test unit-3.14 percent perhour. "Q 

### As stated above, DOE is not changing ADD" 

### is the amountof

### losses that must Hs 

### criterion for 

### gas storage water be added to the jacket losses calculated heaters. DOE 

### bases its conclusions on by 

### the DOE 

### model to match total losses the analysis performed for the with NIST measured losses. As before, Preliminary Statement and additional the DOE 

### criteria is compared with 

### the analysis that was performed subsequent ' ANSI/ASHRAE/IES Standard 90Ato 

### the receipt ofpublic comment. This

- 11.980•. "Q ADD" 

### was considered to be

. includes the testing ofa 

### gas water independent ofinsulation thickness, heater by NIST, 

### as described below, and therefore, the DOE 

### determined the the addition of

### analysis on a 78-gaUon percent oftotal 

### losses that "Q ADD" 

### model unit Several industry comments would be at compliance with ANSI/ suggested that DOE 

### was not studying ASHRAEiIES Standard 90A-1980 with the more prevalent models when it

### used the standingpilot light factored out, as analysis on 100-, 221-, 411-, and 594- follows:. gallon units on which to base its conclusions. !JOA allowed loss rate 

### =(2.3+67

### /V percent per hour)/ Tables 12 and 13 are comparisons 100x energy content ofstored water made ofthe gas storage waterheater (based on 90 °F AT) that**~'1ST** 

### tested with the addition of =0.03159X8.25 Btu/gallon• "FX90 °Fx78 

### fiberglass and foam insulation. The gallons analysis used the NIST test unit that has =il830 Btu/h been labeled MOD1. The MOD1 unit Q 

### ADD w/o pilot

was a basic off-the-shelfunit that had =854/efficiency-pilotenergy+makeup for lost energy from pilot to water been modified to eliminate some =1186-881+269 unnecessary thermal bridges. For further =574 Btu/h information, see the NIST letterreport, Q 

### ADD% .ofallowed loss which is includedin the public record, =574/1830XlOO Surface emissivity was determined to be =3!.4 percent 0.87. 

### The unit had a flue damper. The The January 30, 1989, DOE Interim
test unit came with a standing pilot light. Standards allow a standby loss ofless Input for the pilot 

### light was calculated al than 1.3+38/V or 1.79 percent for this 881 Btu/h. For the purposes of the 78-gallon unit. analysis the pilot light was removed. In Standby loss is calculated as: doing so, 269 Btu/h were calculated as "Q

### TOTAL"/Efficiency/ having delivered energy to the stored (8.25X78X(156.764-72.566J)X100 where: water and thus cannot be counted in the 156.764 is the average tank water temperalure 

### energy lost. This was determined by the 

### f'FJ during the NIST test; and 72.566 is lhe following calculation: average ambient temperature (°F) during the ( o.22){BSl Btu/hl,/0.7Z=

### 269 Btu/h NIST test.Standby loss without the pilot light was calculated as: ("Q 

### TOTAL"/ · where 0.72 is the recovery efficiency of Efficiency_:_Pifot Loss+Makeup Energy)/ the unit and 0.22 is the reported**{8.25X78X(1~6.764-72.566))X100.** 

### efficiency with which the pilot delivers \'\lith a flue damper and an HD, the energy to the stored water. [Hoskins, unit compJies with the addition ofone 19i7] inch offiberglass to the base two inches

In

### Table 12., two inches offiberglass orw:Hh 

### the use of approximately two · insulation (R-12, or k=0.25 Btu·in/h•ft2• inches offoam insulation.

. . °F were used, in like amounts, on the IBlWNG 

### cooe 645iHl1-M

### 55FR23842

23878 Federal Register/ Vol. 55, No. 113 /Tuesday, June 12, 1990 /Rules and Regulatio.1s

Table 12

GAS WATER HEATER (FIBERGLASS INSULATION)

HEIGHT DIAMETER EMIS GALLONS INS TPP INS SIDE

.INS BO'l' 'l:ANK AREA J. AREA W. TEMP A. TEMP Q LOSS Q l\DD Q TOTAL SL SL W/0 PI

( !t) (ft) (in) (in) (in) fsqft) (sq!t) · (F) (F) (Btu/n) (Btu/h) (Btu/h) (\/RR) (\/BR)**--------~------·--·--------------------------** 

# ..**-~----·------------·------------------------------------------------~-----------------------------**

4.50 2.00 0.87 78.00 

### o.oo 'o.oo 0.00 34.56 34.56 160.000 75.000 5463.71 854.0q 6317.7l 16.042 14.923

4.50 2.00 0.87 78.00 0.50 0.50 

### o.oo 34.56 36.54 160.000 75.000 767.10 854.00 1621.10 4.116 2.997

4.50 2.00 0.87 '78.00 1.00 1.00 '0.00 34.56 38.57 160.000 75.000 441.40 as4.oo 1295.40 3.289 2.110

4.50 '2.00 0.87 78.00 1.50 1.50 0.00 34.56 40.64 160.000 75.000 319.88 854.00 1173.88 2.981 l.862

4.50 2.00 0.87 78 .• 00 2.00 2.00 o.oo 34.56 42.76 160.000 75.000 255.36 854.00 1109.36 2.817 1.698

4.50 2.00 0.87 78.00 2.50 2.50 

### o.oo 34.56 44.92 160.000 75.000 216.70 854.00 1070.70 2.719 1..600

4.50 2.00 0.87 78.00 3.00 3.00 

### o.oo 34.56 47.12 160.000 75.• 000 190.56 854.00 1044.56 2.652 1.533

4.50 2.00 0.87 78.00 3.50 J.50 0.00 34.56 49.37 160.000 75.dOO 171.77 854.00 1025.77 2.605 1.486

4.50 2.00 0.87 78.00 4,00 4.00 

### o.oo 34.56 51.66 160.000 75.000 157.65 854.00 1011.65 2.569 1.450

4.50 2.00. 0.87 78.00 4.50 4.50 

### o.oo 34.56 54.00 160.000 75.000 146.68 854.00 1000.68 2.541 1.422

4.50 2.00 0.87 78.00 

### s.oo 5.00 

### o.oo 34.56 56.37 160.000 75.000 137.94 854.00 991.94 2.519 1.400

4.50 2.00 0.87 78.00 5.50 S.50 0.00 34.56 !>8.80 160.000 75.000 130.94 854.00 984.84 2.501 1.382

4.50 2.00 0.07 79.00 6.00 6.00 

### o.oo 34.56 61.26 160.000 75.000 124.97 854.00 978.97 2.486 1.367

4.50 2.00 0.87 7S,OO 6.50 6.50 

### o.oo 34.StS. 63.77 160.000 75.000 120.05 854.-00 974.05 2.473 1.354

4.50 2.00 0.87 78.00 7.00 7.00 

### o.oo 34.56 66.32 160.000 75.000 115.90 854.00 969.90 2.463 1.344



### 88 CZ698 I6.CLN

### 55FR23842.

Federal Register / 

### Vol. 55,

### N~.'113 /Tuesday, Ji'.me 12, 1990 

## I Rules and Regulations 

## 23879

Table 13

GAS WATER HEATER (FOAM INSULATION)

HE!GHT DIAMETER EMIS GALLONS INS TOP INS SIDE IN;i! BO'.\'**T~** AREA J. AREA W. TEMP A. TEMP Q LOSS Q ADD Q TOTAL SL SL W/O PI

(ft) (ft} (in) (in) (in) (sq!t) (sqft) (F) (F) (Btu/h) (Btu/h)**!Btu~h)** (\/RR) (\/RR)**-------------------------------------------------~------------------------~-----?-------------~---~---------------------------------------------.**

4.50 2.00 0.87 78.00 

### o.oo- o.oo •' o.oo 34.56 34.56 •156.764 72.566 5367.64 954;00 6221.64 15.949 14.819 4.50 2.00 0.87 78.00 0.50 0.50 

### o.oo 34.56 • 36.54 ' 156.764 :72.566 1052.67 ss4.90 1906.67 4.888 3.758 4.50 2.00 0.137 78.00 1.00 1.00 

### :o.oo 34;,55 30.51 '156.764 72.566 625.31 854.00 1479.31 3.792 2.663 4.50 2.00 0.87 78.00 1.50 1.50. 

### o.oo 34.56 .40,64 156.764 72.566, 459.08' : 854.00 ' 1313.08 3.366 2.236 4.50 2.00 0.87 78.00 2.00 2.00 

### o.oo 34.56 42.76 156.764 72.566 370.54 954,00 1224.54 3.139 2.009 4.50 2.00 0.87 78.00 2.50 2.50 

### .o:oo 34;55 44.92 ' 156.764 72.566 315.66 854.00 1169.66 2.998 L869 4.50 2.00 0.87 78.00 3.00 3.00 

### o.oo 34**~.56** 47.12 '156.764 72.566 277 .23 654.00' 1131.23 2.900 1.770 4.50 2.00 0.87 76.00 3.50 3.50 0;00 34.56 '49.37 156.764 72.566 '250.56 654.00 1104.56 2.631 1.702 4.50 2.00 0.87 78.00 4.00 4.00 

### o.oo 34.56 51.66 156.764 72.566 230.43 854.00 1084.43 2.780 1.650 4.50 2.00 0.87 78.00 4.50 4.50 

### o.oo 34;56 54.00 156.764_ 72.566 214.74 854.00 1066.74 2.740 1.610 4.50 2.00 O.S7 78.00 

### s.oo s.oo o.oo ·34,56 56.37 155.764 72.!>66 202.22 854.00 1056.22 2.700 1.578 4.50 2

.. 00 0.87 78.00 5.50 5,50 

### o.oo l4,56. '58.80 156.764 72.566 192.00 '854.00 1046.00 2.681 1.552 4.50 2.00 0.67 78.00**6.~00** 6.00 

### o.oo 34.56 ; 61.26 '156.764 72.566 183.56 854.00 1037.56 2.660 ,1.530 4.50 2.00 0.87 78.00 6.50 6.50 

### o.oo l4.56 63.77 156.764 72.566 176.48' 854.00 1030.48 2.642 1.512
"'· 50 2.00 0.07 78.00 7.00 7.00 

### o.oo 34.56 66.32**156.7~4** 72.566 170.48 854.00 1024.48 2.626 1.497



### 89



### ,.

BILLIMG COOE 6450-01-C

### 23880 

### Federal Register / Vol. 55, No. 113 

## JTuesday, June 12, 1990 / Rules and Regulations



# ..
·vu. DOE Reference Materials

AGA. 1981.AGADirectoryof Certified Appliances andAccessories, American Gas Association Laboratories, Cleveland, OH.

ANSI. 1972.ANSIC72.1-1972, American NationalStandard forHouseholdAutomatic ElectricStorage-Type WaterHeaters, American National Standards Institute, Inc., New York, NY.

ANSI. 1984.ANSIZ21.10.3-1984, American NationalStandard for Gas WaterHeaters, Volume III: Circulating Tank, Instantaneous andLargeAutomaticStorage vVaterHeaters, American National Standards Institute, Inc., NewYork. NY.

ANSI. 1985. ANSIZ21.to.3a-1985, Addenda
toAmericanNationalStandardZ21.10.3-1984 for Gas WaterHeaters, Volume III: Circulating Tank, Instantaneous andLarge AutomaticStorage WaterHeaters, American National Standards Institute, Inc., New York, NY.

ANSI. 1986.ANSIZ21.10.3b-1986, Addenda
toAmericanNationalStandardZ21.10.3- 1984, Z21.10.3a-1985for Gas WaterHeaters, Volume Ill: Storage, With InputRatings Above 75,000BtuPerHour, Circulating and Instantaneous WaterHeaters, American National Standards Institute, Inc., New York, NY.

ArthurD. Little, Inc

.. 1976. Studyof Energy Savings OptionsforRefrigerators and Water Heaters, May 1976.

ASHRAE. 1980. ANSI/ASHRAE/IES Standard 90A-1980. Energy Conservation in NewBuildingDesign. American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., Atlanta, GA.

ASHRAE. 1985.ASHRAEHandbook, 1985 Fundamentals. ASHRAE. Atlanta, GA.

ASHRAE. 1985. ANSI/ASHRAE/IES Standard90.1P, Public Review Draft, Energy EfficientDesign of NewNon-Residential Buildings andHigh-Rise Residential Buildings, ASHRAE, Atlanta, CA: June 10, l985.

ASHRAE. 1986. ANSI/ASHRAE/IES Standard90.1P. Second Public Review Draft, EnergyEfficientDesign of NewBuiidings ExceptLow-RiseResMentialBuildings, ASHRAE, Atlanta, GA: August 22, 1986.

ASHRAE. 1987. ASHRAEHandbook, 1987 HVAC Systems andApplications. American Society ofHeating, Refrigerating, and AirConditioning Engineers, Inc., Atlanta, GA.

ASP.RAE. 1987. ANSI/ASHRAE/IES Standard 90.1P, Third Public Review Draft, EnergyEfficient Design of NewBuildings ExceptLow-RiseResidentialBuildings, ASHRAE, Atlanta, GA: September 29, 1987.

ASHRAE. 1988. ANSI/ASHRAE/IES Standard 90A-a-1987,Addenda toEnergy Conservation in NewBuildingDesign. American Society ofHeating. Refrigerating, and Air-Conditioning Engineers, Inc., Atlanta, GA.

ASHRAE. 1989. ASHRAEHandbook, 1989 Fundamentals. American Society ofHeating, Refrigerating, and Air-Conditioning Engineers, Inc. Atlanta, GA.

ASHRAE. 1989.**A~HRAE/IES** Standard 90.1-1989, EnergyEfficient Design of New Buildings Except Low-RiseResidential Buildings, ASHRAE. Atlanta, GA.

Blue. ).L

.. et al. 1979. Buildirig Energy Use Doto Book Edition 2. ORNL-5552-ED-2. Oak ·Ridge National Laboratory, OakRidge, TN. 1979.

Briggs, R.S., D.B. Crawley, and J.S. Schllesing. 1989. Appendix C. Draft Report, Development of Representative Office Buildings. GRI/89--0029. PreparedbyBattella, Pacific Northwest Laboratories for Gas Research Institute, Chicago, IL.

California Energy Commission.

### rnaa. BuildingEnergyEfficiencyStandards. 1988 Edition. P400-88--001. California Energy Commission, Sacramento, CA. July 1988.

Chapman, Alan.

-- Heat Transfer, An Alan Chapman Engineering Text.

Demetri, E.P., MP. Sespanial<., and

### J. Gerstmann. 1984 High-Efficiency Commercial WaterHeaterDevelopment. GRI-84/0188, preparedby Advanced Mechanical Technology, Inc., for the Gas Research Institute, Chicago, IL.

USDOE. 1983. Supplement to: March 1982 ConsumerProductsEfficiencyStandards EngineeringAnalysis aridEconomicAnalysis Documents. DOE/CE--0045, U.S. Department ofEnergy. Washington DC.

USDOE.1984. Notice of Inquiry, Voluntary Performance Standardsfor New Commercial andMulti-FamilyHigh RiseResidential Buildings. 49 FR 3245 et seq. January 24, Federal Register. U.S. Department ofEnergy, Washington, DC.

USDOE. 1986. Notice of Proposed Rulemaking, Interim Standard, Voluntary Performance StandardsforNew Commercial andMulti-FamilyHigh RiseResidential Buildings. 52 FR 17052 etseq. May 6 Federal Register. U.S. Department ofEnergy, Washington, DC.

USDOE. 1988. 1988Energy Conservation Programfor ConsumerProducts, Title 10 CFR 430 Subpart B. Appendix E. U.S. Department ofEnergy, Washington, DC.

USDOE. 1989. Energy Conservation VoluntaryPerformance StandardsforNew CommercialandMulti-FamilyHigh Rise ResidentialBuildiDgs; MandatoryforNew FederalBuildings; Interim Rule, 54 FR 4538 et seq. January 30 Federal Register. U.S. Department ofEnergy, Washington, DC.

Gaston, R.J. 1983. Commercial Water HeaterMarket Characterization. GRI/81- 017{), preparedby Facility and Manufacturing Automation, Inc. for the Gas Research Institute, Chicago, IL.

Goldstein, D.B. 1985. Memorandum to Gerry Groff. "Rationale for Sub-Committee's Proposed 1992 Water HeaterEfficiency Levels," Natural Resources Defense Council, San Francisco, CA. May 17, 1985.

Goldstein, D.B. 1985. Memorandum to Gerry Groff, Lynn Bringhurst, and Bruce Wilcox, "Cost Curve for Wate:r Heater Efficiency Levels Proposed in ASHRAE 90.lP," Natural Resources Defense CounC:I, San Francisco, CA. July 9, 1985.

Harris, 

### J.E. 1984. TestResults andA Recommended Test Procedurefor Heat Traps. NBSIR 84-2851, prepared by the National Bureau ofStandards for the U.S. Department ofEnergy, Washington, DC.

Hoskins, R.A. and E. Hirst. 1977. Energy and CostAnalysis of Residential Water Heaters, ORNL/CON-10, Oak Ridge National Laboratory, Oak Ridge, TN. June 1977.

Langmead, J.P. 1984. Written Comments Submittedto U.S. Department of Energyon theRecommendaHonsforEnergy Conservation Standards andGuidelinesfor New CommercialBuildings. Gas Applia:iice Manufacturers Association, Inc., Arlington, VA. April 25, 1934.

Langmead, J.P. 1987. Statementbefore U.S. Department of Energyon tl1e Proposed Interim Eriergy Conservation Voluritary Performance StandardsforNew Commercial andMulti-FamilyHigh RiseResidential Buildings. Gas Appliance Manufacturers Asaociation, Inc., Arlington, VA. June 11, 1987.

Lang..-nead, 

### J.P. 1937. Written Comments Submittedto U.S. Department of Energyon theProposedInterim Energy Conservation Voluntary Performance StandardsforNew CommercialandMulti-FamilyHigh Rise ResidentialBuildings. Gas Appliance Manufacturers Association, Inc., Arlington, VA. July 27, 1987.

Lippiatt, B.C., and R.T. Ruegg.1988. Energy**Price.~** andDiscountFactorsfor Life-Cycle CostAnalysis 1988. NISTIR 85-3273-3, National Institute of Standards and Technology, Washington, DC.

Arthur D. Little Inc. 1982. Consumer Products EfficiencyStandards Engineering AnolysisDocument. DOE/CE--0030, prepared for the U.S. Departnient ofEnergy, Washington, DC.

Moore, H.J. 1989. Letter to David B. Goldstein, Natural Resources Defense Council. American Appliance Manufacturing Corporation, Santa Monica, CA. 21June1989,

Moore, H.J. 1989. Letter to David B. Goldstein, Natural Resources Defense Council. American Appliance Manufacturing Corporation, Santa Monica, CA. 28 June 1989.

Mutch,

### J.J. 1974. Residential Water Heating. Fuel Conservation, Economics, and PublicPolicy. Prepared for the National Science Foundation, R-1498-NSF.

NIST. 1990. Letter Report to Jean

### J. Boulin, DOE, from Hunter A. Fanney, NIST, on Water Heater Standby Loss Tests. National Institute ofStandards andTechnology, Gaithersburg, MD. May 31, 1990.

Pacific Northwest Laboratory. 1983. RacommendationsforEnergy Conservatfon Standards andGuidelinesforNew CommercialBuildings. DOE/NBB 0051, Vols. I-III. prepared for the Assistant Secretary, Conservation and Renewable Energy, U.S. Department ofEnergy, Washington, DC.

Palla, R.L 1979. Evaluation ofEnergyConservingModificaUonsfor WaterHeaters. NBSIR 79-1783, Final Report, National Bureau of Standards, Washington, DC.

Vasilakis, A.D., J.F. Peraron, and

### J. Cerstmann. 1980. Research andDevelopment of

a High Efficiency Gas-Fired WaterHeater. Volume 1, Final Report Summary, ORNL/ Sub-7381/1; and Volume 2. Concept and MarketEvaluation, ORNL/Sub-7331/2. prepared for Oak Ridge National Laboratory. Advanced Mechanical Technology, Inc

.. Newton, MA.

-. 1988. "Statistical Review ofthe U.S. Appliance Industry", ApplianceMagazine, Aprii 1988. Vol. 45, No. 4., pg. 56. Dana Chase Publications, Inc., Oak Brook, IL.

### Federal Register / Vol. 55, .No. 113 / Tuesday, June 12, 1990 / Rules 

### and Regulations 

### 23881

vm. Summary

The preceding sections of !his Response and Announcement represent DOE's efforts to provide a thorough and subsIanlive response pursuant to the 

### final step 

### in the remand procedure set for!h in the October 6, 1989, Memorandum and Order of the Court in 

### Gas ApplianceManufacturers Association etal. v. 

### Secretaryof Energy. Specifically, DOE has provided

a detailed and substantiated discussion of the reasons for and circumstances surrounding its adoption ofthe water healer standby loss criteria announced today, with attention to the relevant statutory requirements, including those dealing with practicability, cost-benefit analysis and impact on affected groups. In that regard, DOE has addressed the
comments and suggestions submitted by interested persons during the remand procedure, as well as the results oftests and analyses performed in connection with its consideration of those comment!; and suggestions.

In conjunction with the publication of this Response and Announcement, and in further response to the Court's Memorandum 

### and Order, DOE has·also placed in the public rulemaking record all ofthe technical support documents and referenced materials upon which it relied in reaching the decisions discussed in the preceding sections.

List of Subjects in 10 CFR Part435

Architects, Building code officials, Buildings, Energy conservation, Energy conservation building performance standards, Engineers, Federal buildings and facilities. Housing, Waterheaters, Insulation, and Voluntary performance standards. With due consideration ofthe
comments that have been received and the results offurther tests and analyses that DOE has caused to be conducted, and in accordance vvith the remand procedure provided for in the Court's October 6, 1989, Memorandum and Order, DOE is announcing and adopting the water heater standbv loss criteria
set forth in Table 9.3-1

### ~hove (part 435 ofchapter II oftitle 10 of the Code of 

### FederalRegulations subpart A, § 435.109, Table 9.3-1, Standard Rating Conditions and Minimum Performance 

### ofWaterHeatingEquipment).

Issued in Washington. DC, on June 7, 1990. 

### J. Michael Davis,
AssistantSecretary, Conserv-ation and RenewableEnergy. [FR Doc. 90-13661 Filed 6-8-90; 4:31 pm]

SIU.ING CODE 6450-01-M