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### ------- 

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5-051999 0001(OO)(I6-0CT -90-14:02:45) 

## Wednesday October 17, 1990



# Part III


# Department of Energy

Office of Conservation and Renewable Energy

10 CFR Part 430 Energy Conservation Program for Consumer Products; Final Rule Regarding Test Procedures and Energy Conservation Standards for Water Heaters

### 42162 

### Federal Register 

# I Vol. 55. No. 201 

# I Wednesday. October 17. 1990 

# I Rules and Regulations

DEPARTMENT OF ENERGY

Office of Conservation and Renewable Energy

10 CFR Part 430
[Docket No. CA5-RM-7!HOS]
Energy Conservation Program for Consumer Products; Final Rule Regarding Test Procedures and Energy Conservation Standards for Water Heaters

AGENCY: 

### Office ofConservation and Renewable Energy. DepartIP.cltt of Energy.
ACTION: 

### Final rule.

SUMMARY: 

### The Energy Conservation Program for ConsumerProducts is conducted underthe Energy Policy and ConservationAct. as amended. Energy conservation standards for most types ofmajorhousehold appliances. including waterheaters. are among the required Program elements. The legislation also**req~ires** 

### .the Department to establish standardmethods oftesting covered products. In the case ofany amended testprocedure. moreover. the Department must determine to what extent the amended test procedure would alter the measured efficiency of the related energy conservation standard andmake appropriate corrections to the standard.

The purposes ofthe final rule announced today are (i) 

### to improve and refine the testprocedure for water heaters and (ii) 

### to amend the energy conservation standards for electric waterheaters in order to reflect the changes in measured efficiency caused by the revised test procedure. There is

no change to the standardfor gas and oil waterheaters resulting from the revised test procedure.

In addition. today's rule also corrects the effective date ofstandards for mobile home furnaces in § 

### 430.32(e) that

was incorrectly published on February 7. 1989. 54 FR 6077. The correct effective date is September 1. 1990.
OATES: 

### The effective date for this document is April 15. 1991. The effective date ofstandards for mobile home furnaces in § 

### 430.32(e) is September 1. 1990.
FOR FURTHER INFORMATION CONTACT: 

### Carl E. 

### Adams. U.S. Department of

Energy. Office ofConservation and Rene.vable Energy. Forrestal Building. Mail Station. CE-43. 1000 Independence Avenue SW.• Washington. DC 20585. (202) 586-9127 Eugene Margolis. Esq.• U.S. Department

ofEnergy, Office ofGeneral Counsel.

5-051999 0002(00)( 16-0cr -90-14:02:47) 

### Forrestal Building. Mail Station. GC12,1000 Independence Avenue SW., Washington, DC 20585. (202) 586-9507
SUPPLEMENTARY INFORMATION:


### I.

### Background

A. 

### Program Requirements

Part Boftitle III ofthe Energy Policy and Conservation Act (EPCA). Public Law 94-163. as amendedby the National Energy Conservation Policy Act (NECPA). Public Law 95-619. the National Appliance Energy ConservationAct (NAECA) of 1987, Public Law 100-12. and the National Appliance Energy Conservation Amendments of1988 (NAECA 1988). Public Law 100-357. created the Energy Conservation Program for Consumer Products otherthanAutomobiles (Program). 1 

### The thirteen consumer products currently subject to this

.. program (often referred to hereafter as "coveredproducts") include water heaters. the subject oftoday's rulemaking.

Under the Act, the Program consists essentially ofthree parts: testing. labeling, andFederal energy conservation standards. The Department ofEnergy (DOE or Department). in consultation with the National Institute ofStandards and Technology (NIST) (formerly National Bureau ofStandards). is required to amend or establish new test procedures

as appropriate for each ofthe covered products. Section 323. The purpose of the test procedures is to produce test results which measure the energy efficiency. energy use. or estimated annual operating cost ofa covered product during a representative average
use cycle or period ofuse and shall not be unduly burdensome to conduct. Section 323(b)(3). A test procedure is not required ifDOE determines by rule that

one cannot be developed. Section 323(d)(1). One hundred and eighty days after a test procedure for a product is adopted. no manufacturer may represent the energy consumption of. or the cost of energy consumed by, the product except
as reflected in tests conducted according to the DOE procedure. Section 323(c)(2). However. the one hundred and eighty dayperiod referred to in section 323(c)(2) may be extended for a period ofup to an jditional one hundred and eighty days Ifthe Secretary determines that the requirements ofsection 323(c)(2) would impose undue burden. Section 323(c)(3). Test procedures appear at 10 CFR part430. subpartB.

I Part Boftitle III ofEPCA. as amended is referred to in this final rule as the"Act." Part Bof title III is codified at42 U.S.C. 6291-6309.



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...7-08-88 Section 323(e) ofthe Act requires DOE to determine to what extent. if any, a proposed test procedure would alter the measured energy efficiency or measured energy use ofany covered product as determined under the existing test procedure. If

### DOE determines that an amended test procedure would alterthe measured efficiency ormeasured energy
use ofa covered product. DOE is required to amend the related energy conservation standard accordingly. In determining the amended standard. DOE is required to measure the energy efficiency or energy use of representative samples ofcovered products which minimally comply with the existing standard.The average efficiency ofthese representative samples. tested using the amended test procedure. constitutes the amended standard. Section 323(e)(2).


### B. TestProcedures

The initial waterheater test procedures were prescribed by notice issued September 27, 1977. 42 FR 54110 (October4.1977). These original

. procedures coupled laboratory tests and calculations to obtainestimates of energy efficiency for storage type electric. gas and oil waterheaters. The laboratory tests consisted ofa "cold startrecovery efficiency test," which measured the ability ofa waterheater to heat cold water. and a "standby loss test." which measured the energy loss of

a water heater when notproviding heated water. Recovery efficiency and percent standby loss are then mathematically combined in the calculations to obtain an energy factor. DOE's overall measure ofwater heater efficiency. Also. the original procedures included calculations for determining the annual energy consumption and annual operating costs. DOE amended the waterheater test procedures by notice issued August 30. 1979. in order to

.prescribe a "measure ofa waterheater's useful capacity called first hour rating," where useful capacity was the maximum hourly demand which could be met by the waterheater. 44 

### FR 52632 (September 7, 1979).

By notice published in the Federal Register on February 8. 1984. (1984 proposal). DOE proposed to amend its test procedures for waterheaters. 49 FR 4870. The purpose ofthe 1984 proposal

was threefold: First. to extend coverage ofthe test procedUles to heat pump water heaters. a relatively new water heater design not previously covered 

### P" the test procedures; second. to add a method oftesting to determine the first hour rating ofwaterheaters equipped with thermal compensating dip tubes

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

### 42163

which provide a more constant outlet water temperature by controlling the mixing ofincoming cold water with stored hot water; and third, to make modifications to the test procedures that would yield more accurate determinations ofenergy efficiency and cost ofoperationfor gas, oil and electric storage water heaters.

By notice published March 16, 1984, DOE. on request ofthe waterheater industry, extended the commentperiod 42 days and rescheduled the March 15, 1984, public hearing to April 26, 1984. 49 FR 10071.

In comments received in 1984 and throughout 1985, numerous parties requested that DOE withdraw the 1984 proposal and wait until a more comprehensive proposal could be developed. Most notably, on October 2- 3, 1985. DOE and NIST hosted a forum

on testing and rating procedures for

consumer products which was attended by manufacturers. utilities, States, and public interest groups. At the forum, there was unanimous agreement that DOE should withdiaw the 1984 proposal and initiate the development ofa single test procedure method which would be applicable to all types ofresidential type waterheaters, including the instantaneous type ofwaterheaters.

By notice published March 13, 1987 (1987 proposal) DOE proposed a single test procedure for all types ofwater heaters, including instantaneous type water heaters. 52 FR 7972. The 1987 proposal also addressed the matter of four test procedure waivers where four manufacturers ofwaterheaters had received allowance to test certain water heaters under modified test procedures. Since publication ofthe 1987 proposal. a fifth manufacturerhas received a test procedure waiver. The 1987 proposal would extend these modifications to all manufacturers ofsimilar designs and thereby would terminate the five individual waivers. The five waivers

are: A.O. Smith Corporation for its gas water heaters equipped with thermal compensating dip tube, 47 FR 53942 (November 30, 1982), and four manufacturers ofwaterheaters with large thermal mass designs: Bock Water Heaters Inc., 50 FR 47106 (November**1'~,** 

### 1985), modified 51 FR 21975 (June 17. 1986). Ford Products Inc., 50 FR 50678 (December 11, 1985). modified 51 FR 18659 (May 21, 1986). Lochinvar Water Heaters. Inc

.. 51 FR 22966 (June 24. 1988). and Aero Environmental Limited. 53 FR 9687 (March 24, 1988).

The major issues covered in the 1987 proposal included:

(I) 

### Extending the test procedure to

cover heat pump waterheaters and instantaneous type water heaters;

S-051999 0003(OO)(l6-0CT-90-14:02:5I) 

### (2) Revising the method oftest for all waterheaters from a no draw test to a 24-hour simulateduse test which includes a six-hour draw test; and

(3) Revising the first hourrating test from a calculatedestimate to a direct

measure for determining a water heater's ability to supply hot water.

By notice published onJanuary 17. 1989 (1989 proposal) the Department proposed to amend the energy conservation standards oftitle 10. part 430. ofthe Code ofFederalRegulations for water heaters to reflect the changes in measured efficiency which would be causEd by a newlyrevised test procedure. 54 FR 1890. The 1989 proposal discussed all the comments made on the revision ofthe test procedure proposedin the 1987 proposal and included the newlyrevised test. procedure which incorporated those-" comments and which was used to determine the 1989 proposed conservation standard. Furthermore. the 1989 proposal stated that the newly revised test procedure was not included for comment except in regard to the manufacturers' ability to replicate the DOE methodology in complying with the proposed efficiency standards, and indicated that the newly revised test procedure containedin the 1989 proposal would be made final when the revised standard levels for water heaters were made final. Today's notice finalizes the test procedure included in the 1989 proposal as modified by DOE in consideration of those comments dealing with the manufacturers' ability to replicate the DOE methodology in complying with the proposed standards. Today's notice also corrects various typographical errors containedin the 1989 proposal. several ofwhich were initially identified in a correction notice publishedby DOE in the February 9. 1989, Federal Register. 

### 54 FR 6364.

Today's rule amends appendix E of subpart Bof 10 CFR part 430. This new test procedure is effective 180 days after publication of today's final rule. Section 323(cJ(2} of the Act specifies that effective 180 days after an amended or
new test procedure applicable to a coveredproduct is prescribed. no manufacturer may make a representation with respect to energy
use or efficiency ofsuch product or the cost ofenergy consumed by sue;,

. product. unless the product is te"ted in accordance with such amended or new test procedure. Section 323(c)(3) ofthe Act allows for an extension of an additional 180 days of the aforesaid effective date if the Secretary determines upon petition that the requirements ofsection 323(2} would impose an undue burden. The extant



### F4701.FMT

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### ·7-08-88 test procedure will remain in effect until the effective date oftoday's amendment for the purpose ofrating existing water heaters. After the effective date ofthe amended test procedure. all calculations ofenergy efficiency or energy use of waterheaters or cost ofenergy consumedby waterheaters are to be based on the new test procedure. Consequently. all waterheaters must be retested using the test procedure announced today.
C. 

### Energy Conservation Standards

NAECA added a definition for water heaters. as follows:

The term "waterheaters" means a product which utilizes oil. gas. orelectricity to heat potable water for use outside the heaterupon demand. including-

(AJ storage type units which heat and store water ata thermostatically controlled temperature. including gas storage water heaters with an input of75.000 Btu perhour

orless. oil storage water heaters with an input of 105.000 Btu per hour or less. and electric storage water heaters with an input of 12 kilowatts or less:

(B) instantaneous type units which heat waterbut contain no more than one gallon of water per4.000 Btu perhour ofinput. including gas instantaneous waterheaters with an input of200.000 Btu per hour orless. oil instantaneous water heaters with an input of210.000 Btu perhour orless. and electric instantaneous waterheaters with an input of 12 kilowatts or less: and

(C) heat pump type units. with a maximum current rating of24 amperes at a voltage no greater than 250 volts. which are products designed to transfer thermal energy from one temperature level to a higher temperature level for the purpose ofheating water. including all ancillary equipment such as fans. storage tanks. pumps. or controls necessary for the device to perform its function.



### NAECA also prescribes energy conservation standards for 11 types of appliances including the following standards for gas. oil-fired. and electric water heaters.

PrOduct class Energy factor

1. Gas water heater.

..........

# l .62

- (.0019X Rated

: storage volume in 

# I ' gallons). 2. Oil water heater

............. .59-(.0019xRated 

# I storage volume in gallons). 3. Electric water heater..... .95

- (.00132X Rated 

# I storage volume in gallons).

I


### These standards are effective for products manufactured on or after January 1. 1990.

Section 323(e) of the Act requires DOE to determine to what extent. ifany. a proposed test procedure would alter the

### 42164 Federal Register / Vol. 55. No. 201 / Wednesday. October 17. 1990 / Rules and Regulations

measured efficiency or measured energy
use ofany covered product as determined under the existing test procedure. Today's final rule satisfies this requirement with respect to the 1989 proposal. Furthermore. section 323(e} requires DOE to test a representative sample ofcovered products that minimally complies with the existing standard using the proposed test procedures; today's final rule is based

on testing a sample ofunits in accordance with the 1989 proposal which has beenrevised as discussed. 

### infra. Based on the testing. DOE has determined that the standard for electric waterheaters shall be changed to: .93 -(.00132xRated storage volume in gallons). The standards for gas and oil waterheaters shall remain unchanged.

Section 323(e} ofthe Act also provides that models ofcovered products in use before the date on which the amended energy conservation standard becomes effective (or revisions ofsuch models that come into use after such date and have the same energy efficiency or energy use characteristics) that comply with the energy conservation standard applicable to such covered products on the daybefore such date shall be deemed to comply with the amended energy conservation standard.

Today's rule. by establishing test procedures for heatpump waterheaters and gas fueled instantaneous water heaters. also extends the coverage ofthe standards to these products. Heat pump waterheaters must meet the energy standards for electric waterheaters and gas fueled instantaneous waterheaters must meet the energy standards for gas waterheaters. In the case ofgas fueled instantaneous waterteaters, the rated storage volume may be zero.
II. Discussion


### A. Testprocedures

DOE is setting forth herein the final amended test procedures which incorporate changes made to the 1989 proposal. Several comments were received in regard to correcting typographical errors andrelating to a manufacturer's ability to replicate the DOE methodology in complying with the

new efficiency standards. Specification ofElectrical Supply Voltage

Shu Miyazaki (Miyazaki) states the current test procedure specifies that the electrical supply voltage be maintained to within 

## + / - 1 percent ofthe center of the voltage range specified by the

5-051999 0004(OO)(I6-0CT-90-14:02:54) 

### manufacturer. (Miyazaki. No. 74 at 2}.2 Miyazaki maintains that this specification will result in different first hourratings for three identical storagetype waterheaters in which only the specified supply voltage varies. Miyazaki believes that it is absolutely necessary to test all electric water heaters at the same voltage.

Miyazaki is correct in stating that different first hourratings will result if identical storage type-waterheaters are tested with supply voltages which vary in magnitude. However. the Department believes it

### is important that water heaters should be tested at the manufacturers' specified voltage rating. For the vast majority ofstorage-type waterheaters. a fixed voltage is given

on the rating platerather than a specifiedrange. Heatpump waterheater manufacturers typically specify a voltage range. These various voltage ratings are not all the same. It 

### does not

seem appropriate to require a commercial'test laboratory to select. for example, a 240 volt supply voltage when the rating plate specifies a range of210 to 230 volts. Thus DOE concludes that the test procedure should not be altered

as suggested by Miyazaki.
HeatTraps

Public Utility District Number 1 (PUD1) ofSnohomish County. Washington State. comments that it currently operates a rebate program which offers residential customers a $50 rebate ifthey replace their existing electric waterheater with an energyefficient one. (PUD1. No. 87, at I). 

### Qualification for the rebate program is based upon the energy factors published withinThe Gas Appliance Manufacturers Association (GAMA) "Consumers' Directory ofCertified Efficiency Ratings." The issue in question relates to the testing ofthe unit with heat traps ifthey are supplied with the waterheater but are not made an integral part ofthe unit. PUD1 states that since there is no guarantee that the heat traps will actually be installed. the energy factor andEnergy Guide label should not reflect the addition ofany accessories. i.e., heat traps.

Section4.3 ofthe proposed test procedure states "ifheat traps and/or piping insulation are supplied with the waterheater,**~:',en** 

### they shall be installed for te&ting." The Department agrees that there is no way to guarantee that these items will be installed when the waterheater is placed into service. However. ifa unit is supplied with heat

2 Comments on the 1984. 1987. and 1989 proposed rules were assigned docket numbers and are numbered consecutively.



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...7-08-88 traps and/or piping insulation by the manufacturer. DOE believes it is reasonable to assume that these items will be used. Therefore, DOE finds that the test procedure not be changed to address the issue raised.
Definition ofInstantaneous Water Heaters

GAMA suggests that the definition of instantaneous waterheaters berevised to include a criterion which limits the outlet temperature to 180 OF or less. (GAMA. No. 78. at 2; andNo. 87, at 3). GAMA contends that this criterion is a
common point ofdifferentiation between commercial andresidential waterheaters. GAMA further states that the 180 OF criterion is already included in the definitions for gas. electric. and oil storage-type waterheaters in the test procedures. In

### particular GAMA suggeststhe following:

Gas fueled instantaneous waterheater

means a water heaterwhich utilizes gas as the energy source controlled manually or automatically by a waterflow activated control or a combination ofwater flow and thermostatic controL which is designed to deliver water at a controlled temperature of less than 180 

### OF. and which has an input greater than 50.000 Btu per hour andless than 200.000 Btu perhour. and a manufacturer's specified storage capacity ofless than 2 gallons.



### DOE agrees with the above definition ofa gas fueled instantaneous water heater and has incorporated it 

### within the test procedure. Copper Tubing

GAMA states that the reference to copper tubing in section 4.3 ofthe test procedure should be clarified to specify the type used for waterlines. i.e

.. Type "L" hard copper tubing. as opposed to copper tubing used for refrigerant lines. (GAMA. No. 78. at 2).



### DOE concurs with GAMA on this issue and has changed the statement from "Copper tubing, the same size as the connections on the waterheater shall be connected to the tank and extend 24 inches in length" to "Type 'L' hard copper tubing, the same size as the connections on the waterheater. shall be connected to the tank and extend 24 inches in length."
Location ofStorage Tank Temperature Measurement Probes

GAMA recommends that in addition to utilizing the anodic device opening or the reliefvalve opening to insert the temperature measurement probes within

a storage-type water heater. the use of the hot water outlet opening should also be permitted. (GAMA. No. 78. at 2 

### and

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

### 42165

3). 

### Specifically. GAMA recommends that section 4.5 ofthe proposed test procedure be modified as follows:

The temperature sensors shall be installed either through (1) the anodic device opening; (2) the reliefvalve opening; or (3) the hot water outlet. Ifinstalled through the relief valve opening or the hot water outlet. a tee fitting oroutlet piping. as applicable. is installed as close as possible to its original location. Ifthe hot water outlet includes a heat trap. the heat trap shall be installed on top ofthe tee fitting. Added fittings shall be covered with thermal insulation having an R value of4hrft 'F /Btu. 

### DOE agrees with the recommendation

. and in section4.5 ofthe testprocedure has adopted GAMA's recommended language to permit the installation ofthe temperature measurementprobes through the hot water outlet.
Prescribed Value ofDensity ofWater

GAMA notes that the value ofthe density ofwater. 8.Z14 

### Ibm/gal for 58 

### 'F. is incorrect in section 5.1.1. 

### (GAMA. No. 78. 

### at 3).



### Section 5.1.1 

### has been changed to

remove the incorrect number and to require the use ofthe density ofwater at the appropriate temperature which will vary due to allowable tolerances during each test.
Prescribed Value ofSpecific Heat

GAMA requests that values for specific heatbe prescribed throughout the test procedure. (GAMA. No. 78. 

### at 3).



### The values for specificheat cannot be prescribed in advance since they are dependent on the inlet and outlet water temperatures which will vary due to allowable tolerances during each test. Accordingly. this suggestion is rejected.
First HourRating Test

GAMA does not understand why a draw is initiated to activate the heating element(s) orburner unit prior to the first hour rating test ifthe mean tank temperature is within the specified temperature range. (GAMA. No. 78. 

### at 3).



### The purpose ofthe draw noted by GAMA was to eliminate the possibility that the beginning ofthe first hourrating test would coincide with the heating element or burner unit being activated to recover the tank from standby losses. DOE believed that this could cause repeatab'1ity problems. However. through cl;ntinuing testing at NIST. DOE has discovered that this would not be a problem and the requirement ofthe draw ha3 been eliminated.
Test Setup for TableTop Water Heaters

GAMA states that the attachment of two feet ofcopper tubing rising vertically from table top water heaters

5-051999 0005(OO)(J6-0CT-90-14:02:58) 

### is inappropriate. (GAMA. No. 87. 

### at Z). 

### GAMA states that for this type ofwater heater the pipes are run horizontally out from the tank and subsequently downward. GAMA suggests that the following statementbe added to section 4.3 

### ofthe revised testprocedure:

A waterheater 36 inches high orless (commonly referred to as anunder counter or table top model) intended for installation either beneath. adjacent to or in conjunction with a counter shall have the inlet and outlet connections configured as illustrated in Figure 4. Ifthe waterheateris not factory equipped with pipe to extend the field connection point ofthe waterlines to outside ofthe jacket orcabinet. copper tubing shall be used to extendthe water line horizontally to the exteriorofthe jacket or cabinet.



### DOE concurs with the above statement. The test procedure has been changed to incorporate the information into section 4.3.


### First-HourRating

GAMA states that the purpose ofthe first-hour rating is to provide a means of grouping models ofsimilar capability for the "Ranges ofComparability" established by the FederalTrade Commission CFTC) labelling rules. (GAMA. No. 88. 

### at Z 

### and 3). 

### GAMA states that in general the revised firsthour rating will have a uniform effect on all waterheaters. GAMA contends that the models in the 56 to 64 gallon FTC range ofcomparability may move to the 65 to 74 

### gallon range as a result ofthe proposed first-hour rating procedure. GAMA states that the same models will still be grouped together as comparable models. It

### further contends that there is

no benefit to revising the first-hour rating test. and that the new test will create an unwarranted need for retesting.

According to GAMA. test data collected by Electrical Testing Laboratories (ETL) indicates that the hour-long first-hour rating test provides

a value practically the same as the firsthour rating determined using the current test procedure. GAMA believes that the revised first-hour rating test will have a minimal effect on the measured firsthour rating and the current procedure is

as appropriate as the proposed first-hour rating test.

GAMA believes that DOE should retain the current first-hour rating test and add an optional calculation method to take into acco.lilt that the proposed test procedure conditions (mean tank temperature, flow rate. inlet water temperature and ambient temperaturA) differ from those in the existing test· procedure.

DOE notes that the existing procedure interrupts the electrical power or fuel

T:'.4t"7"'" T:"

........,.. r

... n I"'tnl ..., no nn 

### supply to the waterheater during the first-hour rating procedure. Imposing a
one hour power or fuel interruption is an extremely unlikely mode ofoperation for residential waterheaters. Secondly. the current procedure requires a computation which is an attempt to determine how much additional usable hot waterwould be generated if 100 

### percent ofthe thermal input to the tank. less standby losses. heats the water contained within the storage tank to a usable temperature. This canresult in significant error due to the fact that only

a portion of

### the thermal input to the tank would produce usable water. The ability
tn convert thermal input to usable hot wateris a function ofthe waterheater design. Severalwaterheater manufacturers are currently designing and manufacturing waterheaters which maximize the conversion ofthermal input into usable hot water. The existing test procedure does not give credit to the manufacturers ofthese innovative products.

GAMA's contention that the proposed test procedure provides a value practically the same as the first-hour rating using the existing test procedure is incorrect. For waterheaters which employ two heating elements. the results oftests conducted by NIST show that the first-hour rating using the proposed test procedure yields approximately 95 

### percent ofthat obtained using the existing test procedure. For two ofthe three waterheaters tested at NIST which employed a single heating element. the first-hour rating results

were significantly less. up to 30 

### percent. when the proposed test procedure was used as compared to the existing test procedure.

The first hour rating within the existing test procedure combines a measured quantity. the number of gallons removed during a single draw. with a computed quantity. the ability of the waterheater to produce hot water within a given time intervaL The computed quantity significantly overpredicts the capability ofsome water heaters. in particular, electric water heaters with a single element. to produce water above a prescribed temperature leveL There are two
reasons for this over-prediction. First. the computa'.;on procedure assumes that the energy supplied during the interval between the time at which the thermostat(s) acts to energize a heating element and the end ofthe hour is supplied only to the portion ofwater within the tank. which would be removed during a subsequent draw. This is a reasonably good assumption for electric waterheaters which employ

### 42166 Federal Register 

# I Vol. 55. No. 201 

# I Wednesday, October 17, 1990 

# I Rules and Regulations

dual elements. since the upper element is used to first heat the waterin the upperportion ofthe waterheater. However.for tanks which employ a single element. the waterheater may not be able to elevate the temperature above the requiredminimum outlet temperature. Additionally. the calculation procedure does not take into account the mixing which occurs betweenthe cold entering water and the waterwithin the storage tank during the removal ofhot water.

The first hourrating is gaining recognition as a sizing criterion for selecting waterheaters. Because ofthis. the Departmentbelieves thatit is beneficial to improve the accuracy of the test. as discussed above. especially the relative rankings to recognize water heater designs which improve the first hour rating. This would allow the selection ofa "smaller" waterheater which could meet the consumers needs and save energy by having smaller standby losses. Therefore. DOE is retaining the proposed first hour rating with one minor adjustment.

Through continuing testing at NIST. DOE discovered that under certain conditions the proposed first hourrating test could be non-repeatable because of thermostat variability. To preclude any unacceptable repeatability problems. DOE is today publishing a slightly revised first hourrating test procedure from that previously proposed. As published. ifa draw is underway at the end ofthe hour. that draw is completed. However. ifa draw is not underway. instead ofdrawing the tank down to Tmin 

### at that time. the test is continued until the tankrecovers and then a final draw is performed. In both cases the waterdrawn over the total duration of the test is prorated to one hour. Computation ofStandby Losses

GAMA comments that the revised test procedure gives a significantly different

measure ofstandby loss because ofthe shortened standby period. (GAMA. No. 87. 

### at 3 

### and 4). 

### GAMA states that although the standby loss measurement in the revised test procedure is adequate for the wayin which it is utilized, it should not be used for otherpurposes outside the framework ofthe test procedure. since it is an abbreviated. less precise method in relation to the 48- 

### hour standby loss test method within the current test procedure. GAMA contends that the inclusion ofa specific**calcula~ion** 

### for standby loss in the revised test procedure is an implicit invitation to use this standby loss value for otherpurposes for which it 

### is not suited. GAMA concludes that this term should be deleted.

S-051999 0006(OO)(I6-0CT-90-14:03:01) 

### . GAMA is incorrect in stating that the

reason the revised testprocedure gives

a different measure ofstandby loss. in comparison to the existing test procedure, is due to the decreased test duration. A different standbyloss measurementis obtainedbecause the inlet and outlet piping arrangement has been changed. In the proposed test procedure, two feet ofvertical uninsulated copperpiping are connected to both the inlet and outlet ports ofthe waterheater. The existing test procedure utilizes insulatedgalvanized piping configured in such a manner as to form an externalheat trap. In fact, GAMA clearlypoints out tbis difference and its impact on standbylosses inits comments addressing the proposed amended energy conservation standards for electric waterheaters. Accordingly, GAMA's recommendation is not adopted.
Section 6.1.4



### GAMA states that it

### would simplify matters ifan equation within section 6.1.4 

### were formulated in such a manner
so that a number which is usually negative would not be subtracted from anothernumber. (GAMA, No. 87. 

### at 4).



### GAMA is correct in noting that the form ofthe equation will usually result in a negative number being subtracted from anothernumber. However. DOE believes that the form ofthe equation is

more conceptually correct than that proposed by GAMA in that a higher ending tank temperature represents a positive energy input which is then subtracted. Additionally. DOE does not believe that the current equation is difficult to use and does not agree with changing the equations within section 6.1.4.**OfH~eak** 

### Water Heaters

The number ofcomments received by DOE concerning "off-peak" water heaters exceeded that on any other subject. American Electric Power, Appalachian Power Company. Columbus Southern Power, Indiana Michigan Power Company. Kentucky Power Company. Ohio Power Company. and Wheeling Power Company comment they are pleased that DCJE intends to explore various concepts for testing these units. These utilities state that "off-peak" waterheating is an importa.lt element in both their Energy Management and Load Management Programs. They also state that the current test procedure does not accurately show the energy conservation benefits provided by "offpeak" waterheaters.

DOE contracted with NIST to test an electric "off-peak" type water heater

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...7-08-88 using today's test procedure. The water heater was tested using several different "off-peak" schedules as well as a test in the normal fully-on mode. The result of these tests was that the energy factor essentially stayed constantregardless of whether the tank was tested "off-peak"

ornot. NIST thus concluded that there is

no need for a test procedure which differs from today's test procedure to determine the energy factor ofoff-peak waterheaters.

DOE recognizes that where off-peak electric rates are offered byutilities. customers may obtain economic benefits byusing "off-peak" waterheaters. However, based on the efficiency tests conducted by NIST, DOE has determined that today's test procedure is adequate to measure the energy factor of "off-peak" waterheaters.


### B. Standards

DOE is herein amending the energy efficiency standards for water heaters to reflect the changes necessitatedby the revised test procedures. Several comments were received regarding the proposed revision to the standards and they are discussed below:
Rated Volume

The California Energy Commission (CEC) states that it presumes the allowable energy factor is computedby subtracting from a constant the product ofa second constant times the measured volume. (CEC. No. 82 at 1 

### and 2). However, within the proposedrule, the term "rated storage volume" is used in the computation ofthe Federal energy conservation standards for water heaters. CEC further states that since the meaning ofthe term "rated volume"

as commonly used in the industry is quite different from DOE's intent iT, 

### the proposed rule. the word "rated" should be dropped from the rule. It 

### also notes that footnote number one in the proposed standard referring to the definition of "rated storage volume" is referenced only to gas waterheaters. not to oil or electric waterheaters.

In a related matter. GAMA suggests that DOE adopt the following language

as the definition for "rated storage volume": "The water storage capacity of

a waterheater as specified by the manufacturer." This definition would be substituted for the reference to the tank capacity measurements set forth in the current DOE waterheater efficiency test procedures. (GAMA. No. 78. 

### at 1).



### At the time ofthe proposed rule. there

was not a definition of "rated storage volume." It 

### was DOE's intention to define "rated storage volume" as the measured volume for use in the

### Federal Register / 

### Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations 42167

standard. However, upon further consideration. and for purposes ofthe instant rule. DOE accepts the arguments set forth in the comments regarding industry usage andhas defined "rated storage volume" to mean the water storage capacity ofa waterheater. in gallons, as specified by the manufacturer, i.e., the "rated volume". Additionally. the footnote in the standardhas beenmodified to indicate that this definition applies to all types of waterheaters.

However, the Departmenthas some
concern about this use of "rated storage volume" in the standardbecause the

measure ofthis quantity seems to be relatively uncontrolled andby specifying a large "ratedvolume" a manufacturer canlower the standard level that a waterheatermust meet. In oral testimony at the January 1989 public hearings, DOE staffpointed out that all the waterheaters tested by NIST in 

### support ofthis rule had measured volumes smaller than the "rated volume." GAMA staffreplied that this difference was due to manufacturing tolerance. While DOE does not have enough data to be statistically significant, it questions whether the difference in rated and measured volume is due solely to manufacturing tolerance. If

### that were the case, one would expect some measured volumes to be above the "ratedvolume" and

some to be below. All 13 waterheaters' tested had measuredvolumes lower than the "rated volume". Further, oral testimony by GAMA at the January. 1989 public hearings indicated that "the vast majority are below the rated number." However, at the same time. DOE is not aware ofany evidence or data which suggests that abuse or
consumer detrimenthas resulted from

use ofthe definition advocatedby the industry; and. the definition DOE is adopting for this rule has previously been adopted by the 2-21 

### Subcommittee

on Standards for Gas Water Heaters.

Additionally, at the public hearings, DOE staffasked GAMA ifthere were limits as to how high the "rated volume" could be relative to the measured volume. It 

### was stated that this difference was limited by adherence to the testing agency's specifications for safety. However, DOE notes that one of the six elecl 'ic waterheaters and one of the five gas waterheaters tested by NIST in support oftoday's rule exceeded this limit. Thus, again some uncertainty exists with regard to which criterion to use.

As a consequence. DOE will continue to test waterheaters and collect data on rated versus measured volume.

5-051999 0007(OO)(I6-0CT-90-14:03:05) 

### Depending upon the results ofthose tests. as well as experience under the rule adopted today, DOE may consider revising the definition of "rated storage volume" in connection with the next waterheater standards review.
Inclusion ofHeatPump WaterHeaters

GAMA states thatresidential heat pump waterheaters are included as a covered product inNAECA and that they are subject to minimum efficiency requirements. (GAMA, No. 78. at 1).



### DOE agrees andnotes thatby establishing test procedures for heat pump waterheaters. today's rule extends standards coverage to these products. DOE also notes that since hea; pump waterheaters use electric power, they are coveredunder the requirements for electric waterheaters. DOE will consider separate standards for heat pump waterheaters on the nextreview cycle for waterheater standards in 1992.
Amended Energy Efficiency Standards

GAMA states thatit agrees with the proposal to retain unchanged the conservation standards for gas and oil waterheaters. (GAMA, No. 88). Testing, conducted atETL for GAMA, yielded results which were consistent with DOE's data and the conclusion reflected in DOE's proposal for gas and oil water heaters. However. GAMA does not agree with the proposed amended energy conservation standards for electricwaterheaters. GAMA proposes that the minimum efficiency standard for residential electric waterheaters be lowered by 0.04 rather than 0.02. GAMA states that while the average difference ofall the testresults from ETL is less than 0.04. the differences are greater for the small volume models. GAMA further states that since these small volume models represent the majority ofelectric waterheatershipments, the adjustment should be weighted to acknowledge this. The models selectedfor the ETL tests, according to GAMA, represent less popular models or models with special design features, such as models factory equipped with heat traps, low-boy and table top models.

On the otherhand, the American Gas Association (AGA) challenges DOE's proposal to lower the energy efficiency standard for electric waterheaters. (AGA. No. 84). It

### believes that DOE selected an inadequate sample of electric waterheaters to test under the amended test procedure and that the models selected by DQ,E are not truly " representative ofthe universe ofelectric waterheaters available. According to AGA. given these shortcomings in the amended test procedure's methodology. AGA does not believe that DOE can

V"t"""1 t:"a.A." r-1D "'1'\1 ,., /"\0 00 

### justify lowering the statutorilyestablished minimum efficiency standard for electric waterheaters.

AGA urges DOE to conduct additional independent testing ofwaterheaters to verify the differences in test methods before DOE amends the statutory minimum efficiency level. AGA states that the number ofunits tested atNIST represents less than 1 

### percent ofthe

- 1.000 basicmodels ofelectric water

heaters available. AGA further states that testing shouldbe performed on 20- and l00-gallon models and on models with high efficiency factors.

In closing, AGA states that it 

### does not beHeve DOE has put forward sufficient justification to lower the statutory minimum standard for electric water heaters. AGA asserts that the DOE proposal has taken the expedient approach oflowering the statutory mandated minimum efficiency level rather than requiring electric water heaters to comply with the statute.

In response to GAMA and AGA. DOE notes that NAECA requires that efficiency standards shall be revised whenever the test procedures are revised so that units that minimally met the standards under the old test procedure will meet the revised standardunder the new test procedure. In other words, a unit thatmet the standards under a test procedure is not allowed to fail to meet the standardjust because the test procedure has changed. DOE agrees that the units tested are not representative ofthe complete universe ofwaterheaters. However. under NAECA the models tested need not be representative ofthe entire product universe; rather they should be representative ofthose models which marginally comply with the standard. Because the effect ofthe test procedure

on the majority ofmodels which exceed the standards is not relevant to the passfail issue. the pertinent question thus is: what is the effect ofthe new test procedure on those models that only minimally meet the standard?The six electric units tested by NIST for DOE meet this criterion.

As stated above. GAMA submitted test results ofseveral waterheaters tested by ETL using both the old and revised test procedures to support its claim that the**~onstant** 

### in the equation for the electric waterheater standard should be lowered by0.04. However. the units submitted by GAMA were not those marginally at the standard. Therefore. most ofthese test results are not applicable to the question at hand.

DOE recognizes that the number of marginal units tested is limited but believes that they fairly represent

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

marginal units and thatusing the average ofthese results is appropriate. The results ofthese tests were reported in the 1989 Proposal as Tables 1, 2. and 3. Therefore, DOE has elected to modify the standard as proposed in the 1989 Proposal by lowering the first term of the energy factor equationfor electric waterheaters by0.02. which is the average reduction ofthe electric units tested, andby leaving the standard for oil andgas waterheaters unchanged.

In selecting this standard basp.d on average test results. it

### is recognized that

some particularmarginal waterheaters might notmeet the new standard.

It 

### should be noted that any basic model thatwas manufactured before the effective date oftoday's final rule. regardless ofwhen the individual unit

was in fact manufactured. and which

was certified as meeting the standard using the old test procedure, is grandfathered underNAECA as complying with today's standard.

DOE is also concerned over the test results obtainedbyNIST and those submitted by GA,MA in that for the great majority ofunits tested, the measured values for energy factor were less than thatreported in the GAMA 

### directory. If this situation was brought to DOE's attention by one party complaining against another, DOE believes that in an enforcement proceeding the basic model could befound in non.compliance.
III.

### Correction ofEffective Date for Mobile-Home Furnaces Efficiency Standards

In reviewing the final rule regarding certification and enforcement of

. regulations related to energy conservation standards for consumer products published February 7. 1989. in the Federal Register (54 FR 

### 6077), DOE noted that the effective date listed for mobile home furnaces efficiency standards. January 1, 1990. was incorrect. The correct date is September 1. 1990. Today's notice makes that correction.
IV. 

### OtherReviews

A. 

### EnvironmentalReview

Pursuant to section 7(c)(2) ofthe Federal Energy Administration Act of 1974 (FEAA) (15 U.S.C. 761-790), a copy ofthis notice has been submitted to the Administrator ofthe Environmental Protection Agency for comments concerning the impact ofthis proposal

on the quality ofthe environment.

Since the amended test procedures under the Program will be used only to standardize the measurement ofenergy usage and the energy efficiency standards have been adjusted

5-051999 0008(OO)(I6-0CT -90--14:03:08) 

### accordingly to achieve no net change in energyusage, today's rule will not affect the quality or distribution ofenergy usage. and will not result in any environmental impacts. DOE, therefore. has determined that amending the test procedures and adjusting the energy efficiency standards accordinglyunder the Program do not individually or cumulatively have a significant effect on the human environment. Consequently. neither anEnvironmental Impact Statementnor anEnvironmental Assessment is required for today'srule.


### B. Review UnderExecutive Order12291

The final rule has beenreviewed in accordance withExecutive Order 12291. 46 FR 

### 13193 (February 19, 1981). which directs that all regulations achieve their intendedgoals without imposing unnecessary burdens on the economy.
on individuals. onpublic or private' organizations. or on State and local governments. Executive Order 12291 also requires thatregulatory impact analyses beprepared for "majorrules," which it 

### defines as any regulation that is likely to result in: (1) An annual effect

on the economy of$100 million or more; (2) a majorincrease in costs orprices for consumers, individual industries. Federal. State. or local government agencies. orgeographic regions; or (3) significant adverse effects on competition, employment. investment. productivity. innovation. or on the ability ofthe United States-based enterprises to compete with foreignbased enterprises in domestic or export markets.

The final rule amends already existing test procedures for waterheaters and correspondingly adjusts the energy efficiency standards. Accordingly, DOE has determined that any burden imposed on anyperson. industry. or government entity by the amendment of extantprocedures is not significant enough to bring the final rule within the definition of "majorrule."

In accordance with section 3(c)(3) of Executive Order 12291. which applies to rules other than major rules. the final rule was submitted to the Office of Management and Budget (OMB) for review without a regulatory impact analysis.
C. 

### RegulatoryFlexibilityAct

The Regulatory Flexibility Act. 5 U.S.C. 601-612. requires that an agency prepare an initial regulatory flexibility analysis to be published at the time the proposed rule is**publi~~hed.** 

### This requirement (which appears in section 603) does not apply ifthe agency "certifies that the rule will not, if promulgated. have a significant



### F4701.FMT

...[16.30}

...7-08-88 economic impact on a substantial number ofsmall entities." DOE certified in the notice ofproposedrulemaking. and does so again. that the rule, which affects manufacturers ofwaterheaters. will nothave significant economic impact. butrather simply improves the test procedures and adjusts the related energy efficiency standards accordingly. Therefore, DOE certifies that the final rule. as promulgated. will not have a "significant economic impact on a substantialnumber ofsmall entities."


### D. Federalism Review

Executive Order 12612. 52 FR

### 41685 (October 30. 1987). requires that regulations orrules be reviewed for any substantial direct effects on States. on the relationship betweenthe national government and the States, or on the distribution ofpower and responsibilities among various levels of government. Ifthere are sufficient substantial direct effects. then Executive Order 12612 requires preparation ofa Federalism assessment to be used in all decisions involved in promulgating and implementing a regulation or a rule.

By operation ofthe statute. standards under the Program initially preempt inconsistent State regulations. Thus. in theory these standards could be said to have a substantial direct effect on State governments. Today's waterheater standards provisions. however, have the practical effect ofmaintaining the 

### status quo 

### ofthe statutory standards levels. Thus the revised standards provisions will have no added substantive or negative effect on States. Based on the foregoing. DOE has concluded that preparation ofa Federalism assessment for this rulemaking was not warranted.
List of Subjects in 

### 10 CFR Part430

Administrative practice and procedure. Energy conservation, Household appliances.

In consideration ofthe foregoing. the Department ofEnergy amends part430 ofchapter II 

### oftitle 10. Code ofFederal Regulations, as set forth below.

Issued in Washington. DC, October 1,1990. 

### J. Michael Davis. AssistantSecretary. Conservation and RenewableEnergy. 

### PART 430-ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS
1. 

### The authority citation for part 430 continues to read as follows:

Authority: Energy Policy and Conservation Act, title III. part B, 

### as amended by National Energy Conservation Policy Act. title IV, 

### part 2. 

### National Appliance Energy Conservation Act of 1987, 

### and National Appliance Energy

### Federal Register 

# I Vol. 55, No. 201 

# I Wednesday, October 17, 1990 

# I Rules and Regulations 42169

Conservation Amendments of 1988 (42 U.S.C. 6291-6309).
§ 430.22 [Amended]



### 2. Section 430.22 is amended by revising paragraphs (e)(l) and (e)(2) and by adding paragraph (e)(4) to read as follows:

(e) 

### WaterHeaters. (1) The estimated annual operating cost for waterheaters shall be-

(i) For a gas or oil waterheater, the product ofthe annual energy consumption. determined according to section 6.1.8 or 6.2.5 ofappendix E of this subpart. times the rep!'esentative average unit cost ofgas or oil. as appropriate. in dollars perBtu as provided by the Secretary, the resulting product then being rounded offto the nearest dollar peryear.

(ii) 

### For an electric waterheater. the product ofthe annual energy consumption. determined according to section 6.1.8 or 6.2.5 ofappendix E 

### of this subpart. times the representative average unit costofelectricity in dollars perkilowatt-hour as provided by the Secretary, divided by 3412 Btu per kilowatt-hour. the resulting quotient then being rounded offto the nearest dollarperyear.

(2) The energy factor for the water heaters shall be-

(i) For a gas or oil waterheater. as determined by section 6.1.7 or6.2.4 of appendix E 

### ofthis subpart rounded off to the nearest0.01.

(ii) 

### For an electric waterheater, as determined by section 6.1.7 or 6.2.4 of appendix E 

### ofthis subpartrounded off to the nearest 0.01.

(4) The alternative uniform test method for measuring the energy consumption ofuntested waterheaters shall be that set forth in section 7.0 of appendix E 

### ofthis subpart.

3. Appendix E

### to subpart Bofpart430 is revised to read as follows: Appendix Eto SubpartBofPart430- Uniform Test Method for Measuring the Energy Consumption ofWater Heaters

1. Definitions

1.1. Cut-in means the time or water temperature when a water heater thermostat has acted to increase the energy or fuel input to the heating elements. compressor. or burner.

1.2. Cut-out means the time or water temperature when a water heater thermostat has acted to reduce to a minimum the energy
or fuel input to the Leating elements. compressor. orburners.

1.3. Design PowerRating means the nominal powerrating that a water heater manufacturer assigns to a particular design of

S-051999 0009(00)(16--0CT-90-14:03: 12) water heater. expressed in kilowatts orBtu perhour as appropriate.

1.4. EnergyFactormeans a measure of waterheater overall efficiency.

1.5. FirstHourRating means the amount of hot water the waterheatercan supply in one hour ofoperation.

1.6. Heat Trap means a device which can be integrally connected. or independently attached. to the hot and/or cold waterpipe connections ofa waterheater such that the device will develop a thermal ormechanical seal to minimize the recirculation ofwater due to thermal convection betweenthe water heater tank and its connectingpipes.

1.7. RecoveryEfficiencymeans the ratio of energy delivered to the water to the energy content ofthe fuel consumedby the water heater.

1.8. Standbymeans the time during which water is not being withdrawn from the water heater. There are two standby time intervals used within this test procedure: 

### 's,by.l represents the elapsed time between the"time a t which the maximum mean tank temperature is observed after the sixth draw and the end ofthe 24 hour test; 

### '.,by.• represents the total time during the 24 hour simulated use test when waterwas not being withdrawn from the water heater.

1.9. Gasfueledstorage waterheatermeans
a waterheaterwhich utilizes gas as the energy source andwhich is designed to heat and store water at a thermostatically controlled temperature ofless than 180 OF with an input of75.000 Btu perhour orless and a manufacturers specified storage capacity ofnot less than 20 gallons nor more than 100gallons.

1.10 Electric storage waterheatermeans a water heater which utilizes electricity as the energy source and which is designed to heat and store water at a thermostatically controlled temperature ofless than 180 OF with an input of 12 kilowatts or less and a manufacturers specified storage capacity of not less than 20 gallons nor more than 120 gallons.

1.11 Oilstorage waterheatermeans a water heater which utilizes oil as the energy
source and which is designed to heat and store water at a thermostatically controlled temperature ofless than 180OF with an energy input of 105.000Btu per hour or less. and which has a manufacturers specified storage capacity of50gallons or less.

1.12 Gasfueled instantaneous waterheater

means a water heaterwhich utilizes gas as the energy source controlled manually or automatically by a water flow activated control ora combination ofwater flow and thermostatic control, which is designed to deliver waterat a controlled tempen.ture of less than 180OF. and which has an input lreater than 50.000 Btu per hour and less than 200.000 Btu per hour, and a manufacturers specified storage capacity ofless than 2 gallons.

1.13 Heatpump waterheatermeans a water heater which utilizes electricity as the energy source with a maximum current rating of24 amperes at a voltage no greater than 250 volts. and which is designed to transfer thermal energy from one temperature level to

a higher temperature level for the purpose of heating water. including all auxiliary



### F4701.FMT

...[16.30j

...7-08-88 equipment such as fans. storage tanks. pumps. orcontrols necessary for the device to perform its function.

1.14ASH RAEStandard41.1-86 means the standardpublished in 1986by the American Society ofHeating. Refrigerating and AirConditioning Engineers. Inc. and titled StandardMeasurement Guide: Section on Temperature Measurements.

1.15.ASTM-D-21S6-80means the test standardpublished in 1980by the American Society ofTesting andMeasurements and titled Method for Smoke Density in Flue Gases from Burning Distillate Fuels.

1.16. "Rated Storage Volume" means the water storage capacity ofa waterheater. in s,allons. as specified by the manufacturer.
2. Test Conditions

2.1. Installation Requirements. Tests shall be performed with the water heater and instrumentation installed in accordance with section 4.

2.2.AmbientAir Temperature. The ambient air temperature. shall be controlled to a value between 65.0 OF and 70.0 OF on a continuous basis. For heat pump water heaters maintain the dry bulb temperature at 67.5 ± 1 'F. Additionally, for heat pump waterheaters the relative humidity shall be maintained between 49 and 51 percent.

2.3. Supply Water Temperature. The temperature of the water being supplied to the waterheater shall be maintained at 58 

### ± 2 OF throughout the test.

2.4. Storage Tank Temperature. The average temperature ofthe waterwithin the storage tank shall be set to 135 

### ± 5 OF.

2.5. Supply WaterPressure. During the test when water is not being withdrawn. the supply pressure shall be maintained between 40 psig and the maximum allowable pressure specified by the water heater manufacturer.

2.6. Electricaland/orFossilFuelSupply. 2.6.1. Electrical. Maintain the electrical supply voltage to within 

### ± 1 percent ofthe center of the voltage range specified by the waterheater and/orheat pump manufacturer.

2.6.2. Natural Gas. Maintain the supply pressure in accordance with the manufacturer's specifications. Ifthe supply pressure is not specified. maintain a supply pressure of 7 to 10 inches ofwatercolumn. If the water heateris equipped with a gas appliance pressure regulator. the regulator outlet pressure shall be within ± 10% ofthe manufacturer's specified manifold pressure. Use natural gas with a higher heating value of approximately 1.025 Btu per standard cubic foot.

2.6.3. Propane Gas. Maintain the supply pressure in accordance with the manufacturer's specifications. Ifthe supply pressure is not specified,**ma:,~tain** a supply pressure of 11 to 13 inches of :.yater column. If the water heateris equipped with a gas appliance pressure regulator. the regulator outlet pressure shall be within ± 10% of the manufacturer's specified manifold pressure. Use propane gas with a higher heating value ofapproximately 2.500 Btu per standard cubic foot.

2.6.4. Fuel OilSupply. Maintain an uninterrupted supply offuel oil. Use fuel oil

### 42170 

### Federal Register / Vol. 55, 

### No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

with a heating value ofapproximately 138,700 Btu pergallon.
3. Instrumentation

3.1. Pressure Measurements. Pressure measuring instruments shall have an error no greater than the following values:

Item measured

Gas pressur?..•...•.
Atmospheric

pressure. Water pressure....• Instrument accuracy

±0.1 inch 01 water

column. ±0.1 inch 01

mercury column.
± 1.0 pounds per

square inch.

3.2. Temperature Measurement Instrument precision

±0.05 inch ot

water column ±0.05 inch ot

mercury column ±0.50 pounds per

square inch

3.2.1. Measurement. Temperature measurements shall be made in accordance with the StandardMeasurement Guide: Section on Temperature Measurements, ASHRAE Standard41.1-86.

3.2.2. AccuracyandPrecision. The accuracy andprecision ofthe instruments, including their associated readout devices, shall be within the limits as follows:

Ilem measured

Air dry bulb

### temperat~re ...............1 Air wet bulb temperature

..............1

### Inl~~ea;~..

### ~~~.I~.~..

### ~~.~~~.•

### ~~:~:.~~.. Storage lank temperatures

...........

, Instrument accuracy

±0.2'F :t:0.2'F Instrument precision

±O.l'F :t:O.l·F

:!:O.l'F :t:O.2S'F

3.2.3. Scale Division. In no case shall the smallest scale division ofthe instrument or instrument system exceed 2 times the specified precision.

3.2.4. Temperature Difference. Temperature difference between the entering and leaving water may be measured with any ofthe following:

a. A Thermopile b. Calibrated resistance thermometers

c. Precision thermometers d. Calibrated thermistors e; Calibrated thermocouples f. Quartz thermometers 3.2.5. Thermopile Construction. Ifa therml.lpile is used. it shall be made from

5-051999 0010(00)(I6-0CT -90-14:03: 16) calibrated thermocouple wire taken from a single spool. Extension wires to the recording device shall also be made from that same spool.

. 3.2.6. Time Constant. The time constant of the instruments used to measure the inlet and outlet water temperatures shall be no greater than 5 seconds.

3.3 LiquidFlowMeasurements. The accuracy ofthe liqUid flow rate measurement. using the calibration iffumished, shall be equal to or less than 

### ± 1% ofthe measured value in mass units perunit time.

3.4. ElectricEnergy. The electrical energy used shall be measured with an instrument and associated readoutdevice that are accurate within 

### ± 1% ofthe reading.

3.5. FossilFuels. The quantity Dffuel used

. by the waterheater shallbe measured with

an instrument and associatedreadout device that is accurate within 

### ± 1% ofthe reading.

3.6. Mass Measurements. Mass measurements shall be made measured with instruments that are accurate within 

### ± 1% of the reading or 0.1 Ibm. whichever is gfeater.

3.7. Heating Value. The higherheating value ofthe natural gas, propane. orfuel oil shall.be measured with an instrument and associated readout device that is accurate within 

### ± 1% ofthe reading. The heating value ofnatural gas and propane must be corrected for local temperature and pressure conditions.

3.8. Time. The elapsed time measurements shall be measured with an instrument that is accurate within 

### ± 0.5 seconds perhour.
4. Installation

4.1. WaterHeatingMounting. A water heater designed to be free standing shall be installed according to the manufacturer's directions on a % inch thick plywood platform supported by three 2 X 4 inch

runners. Ifthe water heater is not approved for installation on combustible flooring. suitable non-combustible material shall be placed between it and the platform. For heat pump water heaters without a storage tank supplied by the manufacturer. connections shall be made with a storage tank as described in section ·1.9.3 and in accordance

"0 with manufacturer-published installation

instructions. The storage tank and heat pump



### F4701.FMT

...[16,30]

...7-08-88 section shall be placed onplatform(s) constructed as previously described. If installation materials are notprovided by the heat pump manufacturer, use uninsulated 8 foot long connecting hoses. having an inside diameter of % inch. Wall mounted water heaters shall be installed in accordance with manufacturer-published installation instructions on a simulated wall section made from % inch plywood and2 X 4 inch studs. Placement in the test room shall be in an area protected from drafts.

4.2. WaterSupply. The water supply shall be capable ofdelivering water at conditions

as specified in section 2.

4.3. WaterInletand Outlet Configuration. Inlet and outlet piping connections shall be configured as illustrated in Figures 1, 2. or 3 except a waterheater36 inches high or less. (commonly referred to as an under counter or table top model) intended for installation eitherbeneath. adjacent to orin conjunction with a counter shall have the inlet and outlet connections configured as illustrated in Figures 4a and4b. Type "L" hard copper tubing, the same size as the connections on the water heater shall be connected to the tank and extend 24 inches in length. Ifa waterheater 36 inches high or less is not factory equipped withpipe to extend the field connection point ofthe water heater lines to outside ofthe jacket or cabinet. type "L" hard copper tubing shall be used to extend the water line horizontally to the exterior ofthe jacket or cabinet. Unions may be utilized to facilitate installation and removal ofthe piping arrangements. A pressure gauge and diaphragm expansion tank shall be installed in the supply waterpiping at a location upstream ofthe 24 inch cold water inlet pipe. An appropriately rated pressure and temperature reliefvalve shall be installed on all water heaters at the port specified by the manufacturer. Discharge piping for the relief valve shall be non-metallic. Ifheat traps and/

or piping insulation and/or pressure relief valve insulation are supplied with the water heater. then they shall be installed for testing. Clearance shall be provided such that none ofthe piping contacts other surfaces in the test room.

BILLING CODE 6450-01-M

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

To 

### Scale or

III 

### Water meter

"'0 

### Scale or

OIl 

### Water meter Flow 

### Regulator



### 24-

Flow Regulator

# J

TOlIT



## - 

# 1-

To 

### Scale or 

### 24-



# ... Water meter Flow Regulator 

### Figure 1

Figure 

### 2

Figure 3 24- 

# J

TIN



### 24- 

# 1 Expansion

< 

### Tank

Expansion Tank

Expansion Tank



# o 

# ..26'7 42171

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

# T

3S- 

# --

... ;' 

# , / '\**~-----1** 

### I I I I I I I 

### I

.....-- ... I



### ;' ,I



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

# , / '\**~-----1** 

### 1 1 1 J 

### I I 

# I

....--.... 1 / 'I



## Figure 4b.

BILLING CODE 6450-01-C 

## Expansion Tank

To Scale or
It 

## Water meter

### Federal Register / 

### Vol. 55, No. 201 / 

### Wednesday. October 17. 1990 / 

### Rules and Regulations 42173

4.4. Fueland/orElectricalPowerand Energy Consumption. Install one or more instruments which measure. as appropriate. the quantity and rate ofelectrical energy and/orfossil fuel consumption in accordance with section 3.

4.5. InternalStorage Tank Temperature Measurements. Install six temperature measurement sensors inside the waterheater tank with a vertical distance ofat least four inches between successive sensors. A temperature sensor shall be positioned at the vertical midpoint ofeach ofthe six equal volume nodes with the tank. Nodes designate the equalvolumes used to evenlypartition the total volume ofthe tank. As much as is possible. the temperature sensor should be positioned away from any heating elements. anodicprotective devices. tank walls. and flue pipe walls. Ifthe tank cannot accommodate six temperature sensors and meet the installationrequirements specified above. install the maximum number of

sensors which comply with the installation requirements. The temperature sensors shall be installed either through: (1) The anodic device opening; (2) the reliefvalve opening;

or (3) the hot water outlet. Ifinstalled through the reliefvalve opening or the hot water outlet. a tee fitting or outlet piping. as applicable. shall be installed as close as possible to its original location. Ifthe hot water outlet includes a heat trap. the heat trap shall be installed on top ofthe tee fitting. Added fittings shall be covered with thermal insulation having an Rvalue of4 hr·ft2·'F/ Btu.

4.6. Ambient Temperature. The ambient air temperature shall be measured approximately at the vertical mid-point ofthe heater and approximately 2feet from the surface ofthe waterheater. The sensor shall be shielded against radiation.

4.7. InletandOutlet Water Temperature Measurements. Install temperature sensors in the cold-water inlet pipe and hot-water outlet pipe as shown in Figures 1. 2. or 3. as applicable.

4.8. Flow Control. A flow control valve shall be installed to provide flow as specified within section 5

4.9. Flue Requirements. 4.9.1. Oil-Fired WaterHeaters. Establish a draft at the flue collar as specified in the manufacturer's literature. Establish the draft by using a sufficient length ofvent pipe connected to the waterheater flue outlet and directed vertically upward. For an oil-fired water heater having a horizontally discharging draft hood outlet. a 90 degree elbow having a diameterequal to the largest flue collar size ofthe draft hood shall be connected to the draft hood outlet. A length ofvent pipe sufficient to establish the draft shall be connected to the elbow fitting and oriented to discharge vertically upward. Direct vent oil-fired waterheaters should be installed with venting equipment as specified in the manufacturer's instructions, using the minimum vertical and horizontal lengths of vent pipe recommended by the manufacturer.

4.9.2. Gas-Fired WaterHeaters. Establish a natural draft in the following manner. For gas-fired water heaters haVing a vertically discharging draft hood outlet. a 5foot vertical vent pipe extension having a diameterequal

S-{)S1999 0012(00)(16-0CT -90-14:03: 19) to the largest flue collar size ofthe draft hood shall be connected to the draft hood outlet. For gas-fired waterheaters having a horizontally discharging draft hood outlet. a 90 degree elbow having a diameter equal to the largest flue collar size ofthe draft hood shall be connected to the draft hood outlet. A 5foot length ofvent pipe shall be connected to the elbow and oriented to discharge vertically upward.

Direct vent gas-fired waterheaters shall be installed wthventing equipment specified in the manufacturer's instructions using the minimum vertical andhorizontal lengths of vent pipe recommended by the manufacturer.

4.9.3. HeatPump WaterHeaterStorage Tank. The tank to be used for testing a heat pump waterheaterwithout a tank supplied by the manufacturer shall be an electric storage type water heaterhaving a volume of 47.0 gallons ± 1gallon with an Energy Factor of0.87 ± .01 as determined in accordance with section 6.1.7 with two 4.5 kW heating elements controlled in such a manner as to prevent both elements from operating Simultaneously.
5. Test Procedures

5.1. Storage Tank andHeatPump Water Heaters.

5.1.1. Determination of Storage Tank Volume. Determine the storage capacity. V.1o ofthe water heaterunder test. in gallons. by subtracting the tare weight-measured while the tank is empty-from the gross weight of the storage tank completely filled with water with all aireliminated and line pressure applied as described in section 2.5. and dividing the resulting net weight by the density ofwater at the appropriate temperature.

5.1.2. Setting the Thermostatfor a Thermostatically Operated WaterHeater. Starting with a tank ofsupply water. initiate normal operation ofthe water heater. After cutout. observe the mean tank temperature (based on the six temperature sensors) every minute until the maximum value is observed. Determine whether this maximum value of the mean tank temperature is within the range of 135'F ±5'F. Ifnot. tum offthe water heater. adjust the thermostat. and refill the tank with supply water. Then. initiate normal operation ofthe waterheater. and once again determine the maximum mean tank temperature after cut-out. Repeat this sequence until the maximum mean tank temperature after cut-out is within the range of 135'F ±5'F. Ifa water heater has two thermostats. the thermostat which controls the upper heating element shall be set first to yield a maximum water temperature of 135'F ±5'Fas measured by the temperature tank

sensors above the upper heating element.The thermostat which controls the lowerheating element.:haH then be set to yield a maximum

mean tal,k temperature of 135'F ±S'F. For heat pump water heaters. which control an auxiliary resistance element. the thermostat shall be set in accordance with the manufacturer's installation instructions.

5.1,3. PowerInputDetermination. For all waterheaters except electric types haVing immersed heating elements and initiate normal operation and determine the power input. P. to the main burners (including pilot



### F4701.FMT

...r16,30J

...7-0B-BB light power. ifany) after 15 minutes of operation. Ifthe waterheater is equipped with a gas appliance pressure regulator. the regulator outlet pressure shall be set within ±10% ofthat recommended by the manufacturer. For oil fired waterheaters the fuel pump pressure shall be within ±10% of the manufacturer's specified pump pressure. All burners shall be adjusted to achieve an hourly Btu rating that is within ±2% ofthe value specified bythe manufacturer.For an oil-fired waterheater. adjust the burner to give a CO2 readingrecommended by the manufacturer and an hourly Btu rating that is within ±2% ofthat specified by the manufacturer. Smoke in the flue may not exceed No.1 smoke as measured by the procedure in ASTM-D-2156-80. Gas- and oilfired water instantaneous waterheater&shall have the burners adjusted to the manufacture's maximum firing rate value.

5.1.4. FirstHourRating Test. Establish normal water heater operation with the maximum mean tank temperature within the range specified in section 2.1.4. Begin the first hour rating test after the thermostat has acted to reduce the electrical power or fuel input to the water heater and the maximum**~torage** tank temperature has been achieved. If the waterheater incorporates a heat-pump. wait until both the heat pump and electrical heating element(s) have ceased to supply energy to the storage tank. Record the time. oil. gas and/or electrical meterreadings as appropriate. Do not interrupt electrical power and/or fuel to the waterheater. The rate of waterwithdrawal shall be 3.00±0.25 gallons perminute. Draw and collect water withdrawn from the waterheaterin a suitable container for the purpose of determining its weight at the conclusion of the test. During the draw record the inlet and outlet fluid temperature beginning 15 seconds after the start and at every subsequent 5 second interval throughout the duration of each draw. Alternatively. a water meter may be used to directly measure the volume of water withdrawn. Record the maximum outlet temperature which occurs during the draw as Tmalt. The withdrawal ofwater shall continue until the outlet temperature drops to

a value 25'F below Tmalt. defined as Tmin. ;lt which time the draw shall be terminated. Record the average outlet temperature and

mass removed as Tdel.i and Mit respectively. If the thermostat acts to reduce the supply of fuel to the main burneror electrical input to the upper heating element ofa multiple element electric water heater. orelectrical input to a waterheater having a single element or multiple elements which operate simultaneously. before one hour has elapsed. initiate a second draw. During the draw record the outlet fluid temperatures beginning 15 seconds after initiating the draw and at every subsequent 5 second interval throughout the duration ofeach draw until the outlet tempelature drops to Tmin. at which time the draw is terminated. Record the average outlet temperatures as well as the

mass removed. Continue this sequenct: of events until one hour has elapsed. Ifa draw is currently taking place. continue the draw until the outlet temperature reaches Tmin• and record the elasped time between the

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

previously recorded time. at the beginning of the first draw. and the termination ofthis final draw as rfhr' Ifa draw is not taking place at the end ofone hour. waituntil the thermostat acts to reduce the supply offuel to the main burner or electrical input to the upper heating element ofa multiple element electric waterheater. or electrical input to a water heaterhaving a single element or multiple elements which operate simultaneously. to initiate the final draw. During the final draw. record the outlet fluid temperature beginning 15 seconds after initiating the draw and at every subsequent 5 second intuvals throughout the duration of the draw until the outlet temperature drops to Tmin' at whirh time the draw is terminated. Record tht: <llasped time betweenthe previously recorded time. at the beginning of the first draw. and the termination ofthe final draw as t'fhr> In either case. record the outlet temperatures and the mass removed during the final draw.

5.1.5.24HourSimulated Use Test. During the simulated use test, a total of64.3 gallons

are removed. With the waterheater turned off. fill the waterheaterwith supply water and applypressure as described in section 2.1.5. Turn on the waterheater and associated heat pump unit. ifpresent. Wait until cutout occurs at 135°F ±SoF, as specified in section

## i:1.4. After the cutout

occurs. measure the mean tank temperature using the temperature sensors described in section4.5 everyminute until the maximum

mean storage tank temperature is achieved. The waterheater may be operated through up to three successive cycles ofdrawing 10 gallons perdraw. permitting recovery between each draw. prior to the start ofthe test. Record at this time (des!gnated as ,=0). the mean tank temperature (To). and the oil. gas. and electrical energy measurements as appropriate. Begin the 24 hour simulated use test by drawing an amount ofwaterout of the water heater equivalent to one-sixth of the daily hot waterusage. 64.3 gallons. Record the average storage tank and ambient temperature every 15 minutes throughout the 24 hour simulated use test unless recovery or
a draw is occurring. At elapsed time intervals ofone. two. three. four and five hours from r=O). initiate additional draws removing an amount ofwater equivalent to one-sixth of 64.3 gallons. with the maximum allowable deviation for any single draw being ±O.S gallons. The quantity ofwater drawn during the sixth draw shall be increased or decreased as necessary such that the total '/olume ofwaterwithdrawn shall be equal to 34.3±1.0 gallons.

All draws during the simulated use test are to be made at flow rates of 3.0±0.2S gallons per minute. Measurements of the inlet and outlet temperatures shall be made beginning 15 seconds after the draw is initiated ard at every subsequent 5 second interval throughout the duration ofeach draw. The airithrnetic mean of the hot water discharge temperature and the cold water inlet temperature shall be determined for each draw. Record the scale or meter reading. as appropriate. after each draw. At the end of the recovery period following the first draw. record the maximum mean tank temperature observed after cut-out.

S-D51999 0013(00)( 16-0CT -90-14:03:24) Tmax.t. and the energy consumed. Qr for oil. gas. and heat pump waterheaters including auxiliary energy such as pilot lights. pumps. fans. etc. Forheat pump water heaters Qr. is the sum ofthe energy consumed by the heat pump and the electrical heating elements(s).

At the end ofthe recovery period following the sixth draw. record the total electric and/

or fuel energy consumption. Q.u. and the scale reading orthe meterreading. as appropriate. Ifa water scale is used. determine the net weight ofthe water withdrawn. MFHR in pounds. Record the maximum value ofthe mean tank temperature aftercutout as

### 'f.u• Except as noted below. allow the waterheaterto remain in the standby mode until 24 hours have elapsed from the start ofthe test. t =0. Prevent the waterheaterfrom beginning a recovery cycle during the lasthourofthe test by turning offthe electric power to the electrical heating elements and heat pump. if present. or by turning down the fuel supply to the main burner at an elapsed time of23_ hours. Ifa recovery is taking place at an,. elapsed time of23 hours. wait until the recovery is complete before reducing the electrical and/or fuel supply to the water heater. At 24 hours. record the mean tank temperature.

### 1'2•. and the electric and/or fuel instrument readings. Determine the total energy consumption during the entire 24 hour simulated use test. Q. Record the time interval between the time at which the maximum mean tank temperature is observed after the sixth draw and the end ofthe 24 hour test as r"by.l' Record the time during which waterwas not being withdrawn from the water heater during the entire 24 hour period as l' .tby.2.

5.2 Instantaneous WaterHeaters

5.2.1. Setting the OutletDischarge Temperature. Initiate normal operation ofthe water heater at the full input rating. Monitor the discharge water temperature and set to a value of 13S'F ± S'F in accordance with the manufacturer's instructions. Ifthe water heater is not capable ofproviding 3.00 ± 0.25 gallons per minute then adjust the flow rate

as necessary to achieve the specified discharge water temperature. Record the corresponding flow rate as V max• Ifthe instantaneous water heater incorporates a controllerwhich permits continous burner operation at a reduced input rate, adjust the flow rate as necessary to achieve a discharge water temperature of 135' ± S'F while maintaining the minimum input rate. Record the corresponding flow rate. V min' Ifan outlet temperature of 135° ± S'F cannot be achieved at the minimum allowable flow rate permitted by the instantaneous water heater. record the flow rate as V min and the outlet temperature as Tmin•

5.2.2. PowerInputDetermination. For oil and gas flow actuated water heaters, adjust the burners to the maximum firing rate value specified by the manufacturer.

5.2.3. First HourRating Testfor Instantaneous WaterHeaters. Establish normal heateroperation at the maximum input rate with the discharge water temperature set in accordance with section 5.2.1. Record the time. oil. and/orgas meters



### F4701.FMT

...[16.30}

...7-08-88 as appropriate. Do not interrupt electrical or fuel to the water heater. DraY)' and collect waterwithdrawn from the water heater. while recording the inlet and outlet fluid temperatures beginning 15 seconds after the draw is initiated and at every subsequent 5 second interval throughout the duration of the draw in a suitable container for the purpose ofdetermining its weight at the conclusion ofthe test. Alternatively. a water metermay be used to directly measure the value ofwaterwithdrawn. At the end ofone hour terminate the draw. Determine the mass ofwaterwithdrawn. MFIIR• in pounds. or the volume ofwaterwithdrawn. V FHR. in gallons with an errorno greater than 2percent.

5.2.4. 24HourSimulated Use Test

5.2.4.1. FixedInputInstantaneous Water Heaters. Establish normal operation with the discharge water temperature and flow rate set to values of 13S DF ± 5°F andV max. respectively. Record the oil. gas. and electrical energymeasurements. as appropriate. Begin the 24 hour simulated use test by drawing an amount ofwaterout ofthe waterheater equivalent to one-sixth ofthe daily not water usage. 64.3 gallons. At elapsed time intervals ofone. two. three, four. and five hours from 1'=0. initiate additional draws removing an amount ofwater equivalent to one-sixth of64.3 gallons. with the maximum allowable deviation for any single draw being ± 0.5 gallons. The quantity ofwater drawn during the sixth draw shall be increased or decreased as necessary such that the total volume ofwater withdrawn shall be equal to 64.3±1.0gallons. Measurements of the inlet and outlet water temperatures shall be made beginning 15 seconds after the draw is initiated and at every 5 second interval throughout the duration ofthe draw. The arithmetic mean of the hot water discharge temperature and the cold water inlet temperature shall be determined for each draw. Record the scale

or meterreading. as appropriate. after each draw. At the end ofthe recovery period following the first draw. record the energy consumed. Qr. Allow the water heater to remain in the standby mude until exactly 24 hours have elapsed from the start of the test. 1'=0. At 24 hours, record the electric and/or fuel instrument readings. Determine the energy consumption during the entire 24 hour simulated use test. Q.

5.2.4.2. Variable Input Instantaneous Water Heaters. Ifthe instantaneous waterheater incorporates a controller which permits continuous burner operatiail at a reduced input rate. the first three draws shall be conducted using the maximum flow rate, V

max' while removing an amount ofwater equivalent to one-sixth of64.3 galions, with ihe maximum allowable deviation for any
one ofthe three draws being ± 0.5 galions. The second three draws "-hall be conducted at V mtn• Ifan outlet temperature of 135' ± 5'F could not be achieveo. at the minimum flow rate permitted by the instantaneous water heater, the last three draws should be lengthened such that the volume removed is equivalent to

### Federal Register / Vol. 55, No. 201 

# I Wednesday, October 17. 1990 / 

### Rdes and Regulations 42175

V.,5.6 64

6 .3 ,[

__ 7_7_

0F

__]
Tmin-58°F

with the maximun allowable definition for anyone ofthe three draws being ± 0.5 gallons. The quantity ofwater drawn during the sixth draw shall be increased or decreased as necessary such that the total volume ofwaterwithdrawn shall be equal to 32.15 + 3'Vu

.6±1.0gallons. Measurements ofthe inlet and outlet watertemperatures shallbe made beginning 15 seconds after the draw is initiated and at every 5 second interval throughout the duration of ''1e draw. Determine the arithmetic mean ofthe hot water discharge temperature and the cold water inlet temperature for each draw. Record the scale ormeterreading, as appropriate. after each draw. At the end of the recovery period following the first draw. record the energy consumption. Qr. max' Record the energy consumed prior to the fourth draw and at the end ofthe recovery period following the fourth draw. Qr. min'

Allow the water heater to remain in the standby mode until exactly 24 hours have elapsed from the start ofthe test. 7=0. At 24 hours. record the electric and/orfuel instrument readings. Determine the energy consumption during the entire 24 hours simulated use test. Q.
6. Computations

6.1 Storage Tank WaterHeaters. 6.1.1. Storage Tank Capacity. The storage tank capacity is computed using thefollowingVat= (Wr-Wtl/p where V" is the storage capacity ofthe water heater. gallons Wr is the weight ofthe storage tank completely filled with water. Ibm W, is the tare weight of the empty storage tank.lbm p is the density ofwater at the appropriate temperature.1bm/gal. 6.1.2. First Hour Rating Computation. Compute the first h',ur rating as

60 n ! i=l p(135°F

- 58°F}

Which may be expressed as

5-051999 60 n !
i=l p(77°F}

0014(OO)(16-0CT-90-14:03:28) where M\ represents the mass removed during the ith draw ofthe first hour rating test. Ibm Tdel. iis the average delivery temperature for the ith draw which occurred during the first hourrating test. OF 7thr represents the elasped time recorded during the first hour rating test. minutes Tin

.t is the average inlet temperature for the ith drawwhich occurred during the first hour rating test. OF p represents the density ofwaterat the average delivery temperature. Ibm/gal and n represents the number ofdraws which

occur during the test Ifa watermeteris used in lieu ofa scale. the first hour rating is

60 n Vt(Tdel.i-Tln•l) Fhr= --! 7thr i=l 77°F

where Vi represents the volume removed during the ith draw ofthe first hour rating test. gal 6.1.3 RecoveryEfficiency. The recovery efficiency for gas, oil. and heat pump storage type waterheaters is computed as

1)r

V,.pCo2(Tmu.I-To)**+---~~~=--~-** Qr

where M! is the mass withdrawn during the first draw. Ibm Cp ' is the specific heat ofwaterat the average temperature (Td'I.• + Tin.d/2. btu/ Ibm OF Td'I.1 is the average delivery temperature for the first draw. OF Tin.! is the average inlet temperature for the first draw. OF V" is the storage tank capacity. gal p is the density ofwater a!the average temperature [Tmax.! +ToJ/2. Ibm/gal Co2 is the specific heat ofwater at the average temperature (Tmax.I +To}/2. Btu/ Ibm OF Tmo.! is the maximum mean tank temperature recorded after cutout following the first draw. OF



### F4701.FMT

...f16.301

...7-08-88 To is the maximum mean tank temperature recorded prior to the first draw. OF and Qr is the total energy used by the water heaterbetween cutout prior to the first draw and cutoutfollowing the first draw. including auxiliary energy such as pilot lights. pumps. fans. etc.• Btu. (Electrical auxiliary energy shall be converted to thermal energy using the following conversion: 1kWh = 3412.76 Btu.) The recovery efficiency for electric water heaters with immersed heating elements is assumed to be 98 percent.

6.1.4. HourlyStandbyLosses. The hourly standby losses are computed as

where Qhr is the hourly standby energy losses of the waterheater. Btu/hr Q.tby is the total energy consumer by the water heater between the time at which the maximum mean tank temperature is observed after the sixth draw and the end ofthe 24 hour test period. Btu M is the mass ofthe water within the storage tank. Ibm Cp is the specific heat ofwater at the average temperature (T•• + T,uJ/2. Btu/Ibm OF T2• is the mean tank temperature at the end ofthe 24 hour test period. of T,u is the maximum mean tank temperature observed after the sixth draw. OF and T,tby.1 is the elapsed time between the time at which the maximum mean tank temperature is observed after the sixth draw and the end of the 24 hour test period. hours The standby heat loss coefficient for the tank is computed asUA

where T,.stbY is the average storage tank temperature between the time at which the maximum mean tank temperature is observed after the sixth draw and the end of the 24 hour test period. 'F T•.•tby is the average ambient temperature between the time at which the maximum

mean tank temperature is observed after the sixth draw and the end of the 24 hour test period. of and UA is the standby heat loss coefficient of the storage tank.

## 42176 Federal Register / 

### Vol. 55, No. 201 / Wednesday, October 17, 1990 / Rules and Regulations

BTU

hr 'F

6.1.5. DailyWaterHeating Energy ConsumptiQn. The daily water heating energy consumption. Qd is computed as

l1r

where Q is the total energy used by the water heater during the 24 hours simulated use test includ;'"g auxiliary energy such as pilot lights. pumps. fans. etc.• Btu C. is the specific heat ofwater at the average temperature

# rt

..+1'0)/2. Btu/Ibm 'F Mis the mass otwaterwithin the storge tank. Ibm 

### 1'2. is the average tank temperature at the conclusion ofthe 24 hours simulated use test. 'F to is the average tank temperature at the beginning ofthe 24 hours simulated use test. recorded one minute before the first draw is initiated 'F and l1r is the recovery efficiency ofthe hot waterheater. dimensionless. 6.1.6.AdjustedDaily WaterHeating Energy Consumption. The adjusted daily water heating energy consumption. Qda takes into account that the temperature difference between the storage tank and surrounding ambient temperature may not be the nominal value of67.5'F (135'F

- 67.5'F) due to the lO'F allowable variation in storage tank temperature. 135 

### ± 5'F. and the S'F allowable variation in surrounding ambient temperature 6S'F to 70'F. The adjusted daily waterheating energy consumption is computed as
Qda=Qd- [(t.tbY-t •.atbyj- (13S'F-67.5'FlJUATstby.2

where Qda is the adjusted daily water heating consumption. Btu tstby is the mean tank temperature during the total standbyportion. T stby.2. ofthe 24 hour test. 'F 

### l' tb is the average ambient temperature

a.a during the total standby portion. T stby.2. of the 24 hour test. 'F UA is the standby heat loss coefficient for the storage tank. Btu/hr'F andr"bY.2 is the number ofhours during the 24 hour simulated test when water was not being withdrawn from the water 'heater A modification is also needed to take into account that the temperature difference between the outlet water temperature and supply water temperature may not be equivalent to the nominal value of77'F (135'F-S8'F).The following equations adjust the experimental data to a nominal 77'F temperature rise.

The energy used to heat water. Btu per day. may be computed asi=l Mlc.i(f del. I - Tin.;)

l1r

where MI is the mass withdrawn for the ith draw (i=l to 6). Ibm C.Iis the specific heat ofwater. Btu/Ibm 'F

The energy required to heat the same quantity ofwater over a 77 'F temperature rise. Btu per day. is

6 QHW.17 = 1: i=l 

### MI Cpl (135 'F

- 58 OF)

l1T

The difference between these two valuesisQHWD =QHW.77-QHw which must be added to the adjusted daily water heating energy consumption value. Thus. the daily energy consumption value which takes into account that the temperature difference between the storage tank and ambient temperature may not be 67.S'F and the temperature rise across the storage tank may not be 77'F isQdm= Qda

### +QHWD 6.1.7. Energy Factor. The energy factor. E f• is computed as6 MIC.i(135'F-58'F) 

### Er 1: i=l Qdm

where Qdm is the modified daily water heating energy consumption as computed in accordance with Section 6.1.6. Btu
6.1.8. AnnualEnergy Consumption

The annual energy consumption for storage type and heat pump waterheaters is computed asEannual=Qdm'365 where Qdm is the modified daily energy consumption value. Btu per day and 365 is the number ofdays within a year. days
6.2. Instantaneous Hot WaterHeaters.

6.2.1. First HourRating Computation. Compute the first hour rating as

M(f del-fin)
p(135'F

- 58'F)

which may be expressed asp(77'Fj

where M represents the mass removed during the one hour continuous draw. Ibm fdal is the average delivery temperature. 'F tinis the average inlet temperature. 'F
and prepresents the density ofwater at the average delivery temperature. Ibm/gal Ifa watermeter is used in lieu ofa scale the first hourrating is computed asV(t d_l-fin)

77'F

where Vrepresents the volume ofwater removed during the one hour continuous draw. gal

6.2.2. RecoveryEfficiency

6.2.2.1. FixedInput**Instantaneou~** Water Heaters. The recovery efficiency is computed

as

l1r

where M, is the mass withdrawn during the first draw. Ibm Cp1 is the specific heat of**~ater** at_the average temperature (Tdel

.1

### +T'n

..)/2. Btu/lbm'F f dOI•1 is the average delivery temperature for the first draw. OF f ln .1 is the average inlet temperature for the first draw. OF and Qr is the total energy used by the water heater between cutout prior to the first draw and cutout following the first draw. including auxiliary energy such as pilot lights. pumps. fans. etc

.. Btu
6.2.2.2. Variable InputInstantaneous Water Heaters

For instantaneous water heaters which have a variable firing rate. two recovery efficiency values are computed. one at the maximum input rate and one at the minimum input rate. The recovery efficiency used in subsequent computations is taken as the average of these two values. The maximum recovery efficiency is computed as

where MI is the mass withdrawn during the first draw. Ibm Cpl is the specific heat ofwate. at the average temperature ITd• I•1

### +Tin

### .d/2. Btu/Ibm 'F f d

_I•1 is the average delivery temperature for the first draw. 'F fin.; is the average inlet temperature for the first draw. OF and Qr.mu is the total energy used by the water heater between cutout prior to the first draw and cutout following the first draw. including auxiliary energy such as pilot light. Btu

### Federal Register / 

### Vol. 55, No. 201 / Wednesday, October. 17, 1990 / Rules and Regulations 

## 42177

The minimum recovery efficiency is computed as1}r.min

where 

### M. is the mass withdrawn during the fourth draw, Ibm C".. is the specific heat ofwater. Btu/Ibm OF 

### T

d •l.• is the averaJ.le delivery temperature for

the fourth draw, of

Tin•• is the average inlet temperature for the first draw, OF and Qr.min is the total energy consumed immediately prior to the fourth draw and cutout following the fourth draw, including auxiliary energy such as pilot lights, Btu The recovery efficiency is computed asl1r.mu

### +l1r.min l1r 2

6.2.3. Daily WaterHeating Energy Consumption. The daily waterheating energy consumption. Qd is computed asQd=Q where Q is the energy used by the flow actuated waterheater during the 24 hour simulated use test A modification is needed to take into account that the temperature difference between the outlet watertemperature and supply water temperature may not be equivalent to the nominal value of 77 OF (135 OF-58 oF). The following equations adjust the experimental data to a nominal 77 OF temperature rise.

The energy used to heat water may be computed as6 I
i=l l1r

The energy required to heat the same quantity ofwaterover a 77 OF temperature rise is6 I i=l 11,

The differ£;**~e** between these two valuesis5-051999 0016(00)( 16-0CT -90-14:03:36) QHWD=QHW.17-QHW which must be added to the daily water heating energy consumptionvalue. Thus, the daily energy consumption value which takes into account that the temperature rise across the storage tank may not be 77 OF isQam= Q.+ QHWD 6.2.4. EnergyFactor. The energy factor. E,. is computed as6 I i=l Qdm

where Qdm is the daily waterheating**energ~** consumption as computed in accordance with section 6.2.3., Btu 

### Ml is the mass associated with the ith draw. Ibm C

pl is the specific heat ofwatercomputed at a temperature of(58 OF+135 °F)/2. Btu/Ibm OF 

### T

d• l•l is the average delivery temperature for the ith draw. OF and

## T ind is the average inlet temperature for the ith draw. OF 6.2.5. AnnualEnergy Consumption. The annual energy consumption for instantaneous type waterheaters is computed asE.nnual= Qdm • 365 where Qdm is the modified daily energy consumption. Btu perday and 365 is the number ofdays within a year. days.
7. Ratingsfor UntestedModels

In order to relieve the test burden to manufacturers who offer waterheaters which differ only in fuel type or power input. ratings for untested models may be established in accordance with the following procedures. In lieu ofthe following procedures a manufacturermay elect to test the unit for which a rating is sought.

7.1. Gas WaterHeaters. Ratings obtained for gas water heaters using natural gas can be used for an identical water heater which utilizea,propane gas ifthe input ratings are within 10percent.
7.2. Electric WaterHeaters

7.2.1. FirstHourRating. Ifan electric storage type waterheateris available with

more than one input rating. the manufacturer shall designate the standard input rating and the water heaterneed only be tested with heating elements at the designated standard input ratings. The first hour ratings for units having power input rating less than the designated standard input rating shall be assigned a first hour rating equivalent to the first draw ofthe first hourrating for the electric water heaterwith the standard input rating. For units having power inputs greater than the desiJ.lnated standard input rating. the

T"A

__ ...**~""'T'** f.of n 1'\1"\1 ,.., nn nn first hourrating shall be equivalent to that measured for the waterheaterwith the standardinput rating.

7.2.2. EnergyFactor. The energy factor for identical electric storage type water heaters. with the exception ofheating element wattage, may use the energy factor obtained during testing ofthe waterheater with the designated standard input rating. §430.31 [Amended]

4. 

### Section 430.31. 

### Purpose andScope. is amendedby adding the following sentence at the end ofthe section to read as follows: * * * 

### Basic models ofcovered products manufacturedbefore the date

onwhich an amended energy conservation standard becomes effective (or revisions ofsuch models manufactured after such date andhave the same energy efficiency or energy use characteristics) that comply with the energy conservation standard applicable to s1.lch covered products on the day before such date shall be deemed to comply with the amended energy conservation standard. § 430.32 [Amended]

5. 

### Section 430.32, 

### Energy conservation standards andeffective dates, is amended by revising paragraph (d), and by revising the effective date ofentry "2." 

### in paragraph (e) to read "09/01/90." 

### The revised paragraph (d) reads as set forth below:

(d) 

### Waterheaters. The energy factor of**~ater** 

### heaters shall not be less than the following products manufactured on or after the indicated dates:

Product class

1. Gas Water

Heater.

2. Oil Water

Heater.

3. Electric Water

Heater. 

# I Energy lactor. as of Jan. 1. 1990
I i 0.62-(.0019x

Rated Storage Volume in gallons).

I 0.S9-(.OOI9x Rated Storage Volume In gallons). O.95-(.OOI32x

Rated Storage Volume In gallons). 

### i Energy factor. as I of Apnl 15. t991

j

'j' O.62-(.0019x 

# I Rated Storage

Volume in

, gallons).

: O.59-(.0019x 

### I Rated Storage

: Volume In I gallons).

1 0.93-(.00132X Rated Volume



### I Storage In

gallons).

Note: Rated Storage Volume=the water storage capacity
c: a water heater. In gallons. as specified by the**manufactur~** er.

[FR Doc. 9(}-24134 Filed 1(}-11}-90; 8:45 ami

BILLING CODE 6450-01-M



# /7/ 

# ""-

.-