# TUESDAY, OCTOBER 1977

PART 

# m

II



# ENER Y CONSERVATI N PR GR F R



# C PLI NCES

-

Test Procedures for 

# Water Heaters

### 5-1110



### [ 3128-01]

Title 10-Energy
CHAPTER II-FEDERAL ENERGY ADMINISTRATION
PART 430-ENERGY CONSERVATION PROGRAM FOR APPLIANCES
Test Procedures forWater Heaters AGENCY: Federal Energy Administration.
ACTION: Finalrule.
SUMMARY: This rule prescribes final test procedures for water heaters. Appliance test procedures are one element of the appliance energy efficiency program required by the Energy Policy and ConservationAct.
EFFECTIVE DATE: November 8, 1977. FOR FURTIIER INFORMATION CONTACT:

James A. Smith <Office of Conservation). Room 307 Old Post Office Building, 12th and Pennsylvania Avenue NW

.. Washington, D.C. 20461 <202- 566-4635J.
Jim Merna <Media Relations). Room 3104 Federal Building. 12th and Pennsylvania Avenue NW., Washington, D.C. 20461 <202-566-9833>. Robert D. R. de Sugny <Office of the General Counsell, Room 5116 Federal Building, 12th and Pennsylvania Ave-

nue NW., Washsington. D.C. 20461 (202-566-9750 or202-566-9380).
SUPPLEMENTARY INFORMATION:

A. BACKGROUND The Federal Energy Administration <FEA) hereby amends Part430. Chapter II of Title 10. Code of Federal Regulations, in order to prescribe test procedures for water heaters pursuant to sec- tion 323 <42 U.S.C. 6293> of the Energy Policy and Conservation Act <Pub. L. 94-163>. Water heater 

### test procedures

were proposed by notice issued April 21, 1977 <42 FR 21576, April 27, 1977), and a public hearing on the proposed testprocedures was held on June 13, 1977.

By notice issued May 24, 1977 < 42 FR 27896. June 1, 1977),**~** established Subparts A and B of Part 430, Chapter II of Title 10. Code of Federal Regula- tions. Certain definitions and general provisions applicable to the energy con- servation program for appliances have been prODUJ)gated in SUbpart A. Final**test~**procedures for room air condition-

ers. dishwashers, television sets. clothes dryeri;, electric refrigerators, freezers. and electric refrigerator-freezers: have been prescribed in Subpart B and the final test procedure for clothes washers hasbeen issued todayby separate notice. Several other test procedures have been proposed for inclusion in Subpart B and FEA has also proposed a Subpart C for appliance energy efficiency improvement targets. An oJtline of the provisions of Part 430 which have so far been established, including provisions in today·s notice. is as follows: 

### RULES AND REGULATIONS

8t7BPUT A-GENDIJII. PllOVISlONI!
Sec. 430.1 Purpose and seope. 430.2 Definitions.

StnlP.\RT B-TF.sT Paocannu:s
430.21 Purpose or scope. 430.22 Test procedures for measures or energy consumption. (a) Refrigerators and refrfgcrntor-freezers. (b) Freezers.**~cl** Dishwashers. ld) Clothes dryers. (ei**Wat~r** heaters. lf) Room air conditioners. 

## • • (h) Tl'levislon sets.

(J) Clothes washers. 430.23 Units to be tested freserved

### J.
430.2-1 Representations**re~ardlng** mcnsnres of**~nergy** comnimptlon.

(n) Refrigerators and refrigerator-freezers. (b) Freezers. (c) Dlshv:ashers. (d) Clothes drvers. (e) Waterheaters. ( !) Room nlr conditioners.

(h) Television sets.

(j) Clotheswa.shers.

APPENDICES TO SUBPART B Appendix Al-Uniform Test Method for

Measuring the Energy Consumption of Electric Refrigerators and Electric Refrigerator-freezers. Appendix B-Uniform Test Method for Mensuring the Energy Consumption of Freezers. Appendix C-Uniform Teso Method for Measuring the Energy Consumption of Dishwashers. Appendix D-Unlform TestMethod for Measuring the Energy Consumption of Clothes Dryers. Appendix E--Unlform Test Method for Measuring the Energy Consumption of Water Heaters. AppendLx F-Unlform Test Method for Measuring the Energy Consumption of Room Air Condltlooo:rs.


## • • Appendix H-Uniform Test Method for Measuring the Energy Consumption of Television Sets. 

## • • 

## • Appendix J-Uniform Test Method for Measuring the Energy Consumption of Clothes Washers.
B. DISCUSSION OF COMMENTS Comments were received from industry, consumers, and both Federal and State agencies. Those comments which

weredirectly concernedwith thelabeling program under section 324 of the Act

were forwarded to the Federal Trade Commission for consideration in developing labeling rules applicable 

### to water heaters and they are not addressed here.

The following is a discussion of U1e issues raised by those comments which pertained to the technical aspects of the proposed water heater test procedures. The comments have been analyzed by topic, rather than source, since in many

cases thesame orsimilar commentswere received from more Umn one person. 1. nu: BURDl:N OF TESTING Both the electric water heater manu- facturing industry and the oil water heater manufacturing industry com- mented that the proposed test procedure

was undull' burdensome. however. their objections were ba.<sed on dil!erent grounds.

The basis of the electric water heater industry's objection was that testing costs would be prohibitive due to the ex- tremely large number of basic models theywould beconsidered tomanufacture under the 

### test procedure's proposed definition of basic model. That definition categorized units as differentbasic models not only if they differed in factors such 

### as tank capacity and insulation. but also if they differed in heater element wattage or voltage ratings. As a conse- quence. one manufacturer commented that he theoretically offered 20,000 basic models. Another manufacturing firm stated that 144 differentelectrical input configurations are available for each of its electric water heater tank sizes.

FEA finds that the test procedure. 

### as proposed, would prove unduly burdensome for manufacturers o! electric water heaters with immersed heating elements in view of the large number of basic models thatwould have to be tested and the attendant high cost of testing. As 

### a result,FEAhasmadechanges

### totheproposed testprocedure which 

### are designed to reduce the burden of testingfor man- ufacturers of electric water heaters with immersed heatingelements. Thechanges

are based on the fact noted at the hearing andinthecommentsthattheelectrical characteristics of 

### an electric water heater with immersed heating elements have a minimal effect on efficiency for many purposes of the test procedure. It

was therefore feasible to eliminate the distinction between units made on the basis of electrical characteristic-:;. This reduces thenumber of basic models that mostmanufacturers wouldbe considered to produce to twenty according to testimony reeeived at the hearing.

As a. consequence, several important changes in the test procedure have been made. First, the definition of 

### a water heaterbasicmodel wasrevised toe.'tclude immersed heating elements from consideration. Second. the standby loss test for electric waterheaters with immersed heat.mg elements \•;as revised to require the installation of

..standardized" heating elements

## m the water heaters to be tested.Third.thehot'\>-atersupplyrating test and the recovery rate calculation
were deleted from the test procedure. Finally. the method for determining t..11e power input for electric '1.-ater heaters with immersed heating elements 

### v.-as changed. Each of these changes is discussed in detail in other sections of the preamble.

Theoilwaterheatermanufacturingindustry alsocommented thatthetestprocedure was**burden.~me** as applied to them and they requested to be e.icempted from testing.Theybased theirrequest on the fact that they represent only one pcrc<'nt or water heater 

## wcs and the

ffDEllAl l!IEGISTER, VOL 42, NO. 192-TUESDAY, OCTOBER 4, 1977claim that their costs of testing would be higher than for manufacturers of other types of water heaters. The oil water heater manufacturing industry pre;;ented a cost analysis to demonstrate how the costs of testing would result in



### a much higher per unit cost increase for waterheatersproducedbya smallmanu- facturer of oil water heaters with small production runs than for a large manu- facturer of electric water heaters with large production runs. Thus. it was claimed, the much greater increase in price due to testing costs of oil water heaters over gas and electric water heaterswould price the oil waterheaters outside of the water heater market and lead to thedemise of the oil waterheater manufacturing industry.

PEA finds that insufficient evidence has been produced by the oil water heater manufacturing industry 

### to es- tablish grounds for excluding oil water heaters from the water heater test procedure. The cost analysis presented 1s 

### a comparison of hypothetical cases. No evidence was presented 

### to indicate that these hypothetical cases are representative of industry-wide conditions or that the costs would be any different for 

### a. small electric water heater manufacturer.Thesamplingplanused 1nthecost analysis was not the sampling plan which appearedintheproposedtestprocedure and the assumption was made that each manufacturer would test his

own units eventhoughindependenttesting laboratories could be utilized. PEA rejects the recomm1mdation that on waterheatersbeexcludedfrom thewater heater test procedure at this time but mayreconsideritspositionuponthesubmission of sufficient evidence that the test procedure is unduly burdensome or significantly more burdensome 

### to oil water heater manufacturers as com- pared to similar sized manufacturers of othertypes ofwaterheaters.

2. FLUE REQUIREMENTS A commentmadewas thata specification is needed for the attachment of a ftue pipe extension 

### to gas or oil water heaters having horizontal vent outlets. PEA concurs. The :Hue requirement specification in the proposed test procedure inadvertently addressed only water heaters with vertical vent outlets. Section 2.2 of Appendix E has been revised to incorpor!\te a specification for attaching a :Hue pipe to· a water heater with a horizontalventoutle£.

Another comment made was that the test procedure should require that a directventwaterheaterbesetup asspecified in the manufacturer's instructions that accompany the water heater. FEA

concurswith thiscommentwiththepro- \"ii;o that the length of vertical :Hue pipe at.tnched to the water heater must not be greater than the specified five foot length. Section 2.2 of Appendix E has been rei.ised 

### to incorporate this speclfi-

cation.

A third comment suggested the use of

a longer flue pipe extension in the test procedure tobetterrepresentactualcon- dit.ioni; ofgas andoilwaterheaterinstalRULES AND REGULATIONS

lat.ion in the home. While !t would be

more representativeoffield conditions

### to
use a longer length of ftue pipe

### for testing water heaters. e.g

.. 15 feet instead of the specified 5 feet, the physical limitations of the manufacturer's test laborn.- torles might make such a requirement unduly burden>:ome. FEA has therefore not adopted this .suggest.Ion.



# . 3.FUEL HEATING VALUE 

### 5-1111

cation of exact heating values for ga<i and oil fuels. and (2) theburden o! hasing to determine the heating value o! the fuel used in testing with 

### an error of

no greater than one percent.

.

Inthe proposed testprocedwz**heatm~** values for gas and oil fuels were inadvertently specified as exact values. The actual heating value of the fuel used in testing need only approximate the value specified for that fuel in the proposed test procedure. Therefore. section 2.4 of Appendix E has b:.-en revised to specify approximate heating values for gas and oil fuels.

PEArejectstherecommendations that



### a standard heatingvalue be assumed !or each fuel or that local utilities be relied upon 

### to provide the heatingvalue of the fuel they supply. Fluctuations in the heating value of fuels .supplied by utilities do occur

### as studieshaveshO'll.11. PEA does not have sufficient information on the capability of local utilities to provide accurate and meaningful heating value information on the fuel or fuel'> they supply 

### to warrant acceptance o! this means of determining fuel heating value. On the other hand. FEA accepts the recommendation made at the public hearing that water heater manufacturers be permitted the option of purchasing "bottled"fuel which has had its actual higher heating value determined with 

### an error of no greater than one percentascertifiedbythesupplier.

### Thus.



### a. manufacturer would have the choice ofeitherpurchasinga calorimeter, ifone is :i;iot already available. to determine the actual heating value of the fuel or fuels suppliedbythelocalutility orpurchasing the necessary quantity of "bottled.. fuel of a certified heating value. Section 2.4 of Appendix E has been revised to allow for the use of "bottled''gas or a tested oil ofa certified heating value in the test procedure.

4. WATER TEMPERATURE RISE A..._D THERMOSTAT SETTING Several comments were made which questioned the specification of 90° F. in the test procedure for the temperature rise through which a waterheaterunder test must heat the inletwater. One com- ment recommend that •"alues of 

### temperature rise be selected on the basis of geographical regions to better reflect actual conditions where water heaters

are marketed. In other words. the water heater test procedure should be regionalized 

### to account for different water inlet temperatures which result in different temperature rises in \-arious parts of the country.FEArejects this recommen- dation on the basis that

### itwould require water heater manufacturers 

### to conduct manymore tests than currentlyrequired anditv;ouldthereforebeundulyburden-

some. Many comments were directed**tow~!d** Section 2.4 ofAppendix E. "Energy Supply." Moot of these comments concerned the heating values assigned to gas and oil fuels. One such comment was 

### a rec- ommendation that

### a manufacturerofoil water heaters be permitted 

### to conduct testing either .by using fuel oil with 

### a presumably certified heating value of 138,000 Btuper gallon orby determining the actual heating value of the fuel oil used in the test. FEA has assumed that the figure 138,000 cited in the comment above was 

### a. typographical error in the commentandwassupposedtobe 138,500. the heating value o! fuel oil in Btu per gallon cited in the proposed test procedure. Another comment was 

### a recom- mendation thattheheatingvalueof

### natural gas and propane should be designated 

### as approximatenetvalues. A com- r.:>ent was aJq made that specifying 

### a**hea~!ng** valu;:; for natural gas of 1025 Btuperstandardcubicfootis unrealistic since the heating value of the natural gas suppl!edbylocal utilities varies with geographic location. A manufacturing firm impl!ed that the requirement that the actual heating value of the natural gas used in the test be determined with

an error no greater than one percent is unduly burdensome. This firm stated that it does not have the instrumentation available at its water heater manu- facturing plants to measure th:J heating value of the natural gas supplied by the local utilities. It has been this firm·s practice to rely on the local utility to furnish on 

### a.n "as needed" basis the heating value of the natural gas supplied. The firm recommended allowing the use of the gas supplied by the local utilityfortestingontheconditionthatiS identified bytheutility as "natural gas." The firm also stated that its comments concerning the determination of the heating value of natural gas apply to propane gas as well. A comment was made that an ERDA report indicated that the heating value of fuel oil suppliedby utilitiesmaybe aslowas 120,000 Btu per gallon. It was also pointed out that FEA did not state what type of test
was to be used for determiningtheheating value of fuel oil. Th1s can have 

### a dramatic impact on the results it \\'!l.S claimed. Finally, a comment recom- mended that the requirement that natural gas with 

### a heating value of 1025 Btu per standard cubic foot be used in the testbe deleted. the reasonbeingthat the manufacturers performing the tests would have no control oYer the gas supplied bytheutilities.

The concerns expressed in U1e com- ments above fall into two categories: 

### n) the proposed test procedures specifiComments "·ere made U1at the 90• F. temperature rise figure was 

### too high and should be lowered 

### to reflect conditions of operation advocated by FEA. i.e.• that

consumers should lower the thermostat settings on their water heaters to reduce energy consumption. FE.'\ rejects this recommendation. Water heater thermoffOEllAl REGISTER. VOL 42, NO. 192-TU!'SOAY, OCTOl!IR 4, 1977Mats arc normally factory-set for gas heaters at 140° F. and at. 150° F'. for eleetricwaterheaters.Thefact

### Umtthese settings may be adjusted both up or clown b\· U1e installer or the homoov1mer is irrelevant to the determination of the cost of operation unless field surveys indicate that water heaters in representative use are normally adjusted 

### to a different thermostat setting than at the time of purchase. No such field survey datawaspresented atthepublichearing. Therefore. the 

### test procedure uses tile averagevalue of the two common factory. settings of water heater tilcrmostats. 145° F .• as tile best approximation of the typical field waterheater tilermo.statsetting. Since. as stated in the proposed test procedure. NBShas determined that the national average inlet water temperature is 55• F

.. the differencebetween these two temperatures. 90° F

.. is used

a the water temperature rise in U1e test procedure.

Further comments questioned FEA's selection of the inlet water temperature and t-he water heater ther:no.stat setting for the purposes of the test procedure. It is tn1e that these values. 70° F. and 160° F

.. respectively, do not represent field conditions as described by FEA. However. for some testing facilities, climatic conditions and/or other fact-Ors

mav be such that for all or pa!"t of the year tap water temperatures will exceed 55• F. Therefore. if a 55° F. inlet water temperature were 

### to be specified- in the testprocedure. thesefacilities wouldhave t-0 purchase additional equipment to cool the available tap water prior to conducting a test. FEA believes that appropriate and comparable results can be obtained and the test procedure can be made less burdensome if water heaters

are tested wit.'1 an inlet water temperature of 70° F. This inlet water temperature can normally be achieved in laboratories throughout the country at any time ofYe::tr without the need for cooling of the t-ap water. When the inlet water temperature of 70° F. is coupled with the requirement of a 90° F. v.-ater temperaturerise, itresultsina thermostatsetting of 160" F. FEA finds that specifying an inlet water temperature of 70" F. and a water heater thermostat setting of 160° F. makes for a less burdensome testprocedure which justifies their use.

S. OIL WATER HEATER DEFilUTION Comments were made that the definition of an oil water heater in the proposed test procedure included oil water heaters predominantly used in commer- cial and industrial facilities. To exclude commercial andindustrialtypeunits and thereby make the types of oil water heaters covered by the test procedures comparable to the types of gas and electric water heaters covered, it was rec- ommended that the italue of the maxi-

mum energy input rate. 172.500 But per hour in the proposed test procedure, be reduced to 103.875 Btu per hour which equates to an oil consumption rate of 0.75 gallons per hour. It was further recommendedthatthevalueofthema.·dmum energy input rate, 172,500 Btu per RULES AND REGULATIONS

the proJ>C5ed definition of an oil v1ater heater be reduced 

### from 50 

### gallons to 40 

### gallons !or the 

### a.me reason.

PEAfinds 

### that the

### prol)O'.>ed definition of an oil water heater does cover units which are not normally purchased by individuals for household use. FEA has revised the proposed definition of an oil water heater 

### to specify a ma."tlmum energy input rating of 103,875 Btu per hour <which equates to an oii consumption rale o! 0.75 gallons per hour> but has not revised the specified maxim= tank capacity value, 50 gallons. Willi the reduction of the maximum specified energy input rate. FEA finds that oil water heaters witil 50 gallons tank capacities are purchased by individuals for household use and therefore will be cov- ered by the test procedure.

6. llOT WATER USE RATE Many comments questioned the daily hot water usage rate of 64.3 gallons per day specified in the test procedure 

### to compute annual costs of operation. Most of these comments stated that this rate is 

### too high 

### to represent national average conditions. The reason for the apparent discrepnncy between the hot water usage rate specified by FEA and the studies cited in the comments is that FEA's usage rate is based upon representative conditions of use of the types of water heaters covered by the proposedtestprocedure. The comments cited national average use rates basc<l on household surveys which includes waterusage data from households notserviced bythe type ofwaterheaters covered by the proposed. testprocedures such as apartmentdwellings serviced by large commercial water heaters. Including these types of households also lowers the number of persons per household from four, which is used. by FEA t-0 determine the dailyhotwater usage rate, 

### to three, further contributing to a lower usage rate than that used by FEA.

The hot water usage rate of 64.3 gnllonsper daywas arrivedatfrom 

### a survey of 50 gas and 50 electric utility com- panies for hot water and energy usage data for wateiheaters. Eighteenof these companies supplied metered data. Data obtained were normalized 

### to a family of four and 

### to a 90° F. temperature rise. The family size of four was taken from Census Bureau data 

### as the average family size. The types of water heaters covered by the proposed test })rocedure



### are usually found in the service of single families. The use of

### a 90° F. temperature rise is explained in the previous section, Water Temperature Rise and Thermostat Setting. When the hot water usage rate of 64.3 gallons per day and thetemperat·are rise of 90° F. are inserted int-0 the water heater test procedure equations along with typical**wat~r** :t:eater performance parameters of recovery efficiencyandstandbyloss as determined by laboratory tests, the result correlates well with typical home energy usage ns determined by U1e field survey.

Therefore no changes 

### to the proposed
test procedure are considered. necessary with respect 

### to the national ai;erage value o! hot water USAi;e-

..rate as used in the calculation o!**a:verng~** daily energy consumption.

'1. WATER Hl!:ATEP.S NOT con:JU:D BY nu: '!EST Pl!OO:DUl!ES Comments were 

### ma.de that 

### the proposed 

### test procedures do 

### not address solar water heaters. water heater/boiler combinations, or recirculating water heaters.Although**th~** Energy Policy and Conser11ation ActempowerstheA.dmin!strator 

### to include otiler energy rourcE-S. at, this time only those appliances powered byelectricityorfossil fuel.5 aresub-

- ject to testing. Therefore solar water heater manufacturers are not subject to theAct.however, theymayuse thepresent test procedure 

## w provide the con-
sumerwith inCormationconcerningS-Olar water heater performance if they so
cr.oose.

&iler/watcr heater combinations 

### are not. considered in thJs testprocedure be-

cause it is more appropriate to conslder such combinations 

### as systems rather than to attempt to consider the water heaterand boilercomponentsseparately. Since the waterheater P-Ortion of a boiler

/waterheatercombination Is a secondary system of the 

### boiler, FEA finds Lhat it is more appropriate to include boil<er/ water heater combinations with fu..--

naces. Therefore theboiler/waterhEater type of appliance will be considered 

### in. and subject 

### to, the test procedure which is currently under development for fur-

naces.

The recirculating water heater is generally used in large apartment buildings

or for ot.her commercial applications such 

### as office buildings 

### where long 

### runs of piping from the water heater to tile point of use would result in 

### a long delay period before hot water becomes avaiiable at the fixture ifa recirculating system were not used. Very few of these systems are sold t-0 the typical consumer and many are custom designed and cus- tom built. Therefore. the inclusion ofre- circulating systems in the test procedure is not recommended at th!s tlme.

8. TEMPE:RATURE DIFFERENCE BETWEEN

STORED WATER AND ROOM ttMPERATURE AS USED IN THE CALCUI.ATIONS
A commentstated thatthe mean**t~m** perature dilference between the stored watP.r and ro-0m temperature is more likely in therangeof70-80°F.

### sincemost water**hent~rs** are located indoors. The proposed test procedure specilies that a temperature difference.of 90° F. is to be used 

### as the temperature dilference be

### tween the stored 

### water and the 

### room temperature. unlike all of the other i.--al-

ucs specified in this test procedure. tllis i.-nlue !ortemperature difference is a derived i.-nlue rather than 

### a i.--alue determined by empiric-al data. l-"'EA has no data on typical ambient temperatures where v:ater llC!ltC'rs are**m.~talled.** hov:- e\·er. the 

### assumed imlue or 90° F.• when coupled with a hot water usage rate of 64.3 gallonsperd:u·heated through a 90" P. temperature rise. will yield i.·alue:s of calculated energy constm1ption tllnt. agree with nctual energy consumption

RDIERAI. REGISTER. VOL 42, NO. 192-T\lltSOAY, OCT081Ell 4, 19n

### <lilta for 

### waterheaters. A change in 

### th!s value wou!rl ne-J;::.s..<;!tate a change in one of U1e otht'i·r p;:i,rameters such 

### as hot waterusagerate,watertemperaturerise,
N<'.• in order to maintain agreement between theenergy consumptioncalculated by use of the test procedure and actual energy consumed in representative use. Therefore. no change 

### to the specified temperature difference between stored water and room temperature is recom- mended.

!I. l\lEASUREl\IENT AND CALCUL.\TlON OF STANDBY LOSS Concerning the standby loss test, PEA

concurs with thecommentsthatstandby locs for electric water heaters with immersed heating elements 1s virtually independent of energy input rating. Standbyloss isa measureofthehotwater storage performance of a water heater. This measure is primarily a function of thetype andconfigurationofthetank insulation since most of the heat loss during standby 1s through the water heaterjacket to the air surrounding the water heater. This is particularly true for electric water heaters which do not have flue losses and therefore their only other heat loss is through the inlet and outlet pipes whennoheattraps arepresent.Becauseofthisandbecausevirtually all input energy 

### to the heating elements goes towards heating water by the very nature of their design of haVing the heating elements in direct contact with the water in the water heater tank, standbylosswillbethesameforallelectric water heaters with immersed heating elements of a given basic model. Therefore. PEA has adopted the recom- mendation that standby loss tests for electric water heaters with immersed heating elements be performed with the waterheaters tobe tested equipped with "standardized" heating elements. The procedure for determining standby loss for electricwaterheaterswith immersed heating elements is presente<l in section 3.4.2 ofAppendixE.

A suggestionwasmade ti.at determining standby loss in terms of the fraction of the heat content of the stored water lostperhourinsteadofinunits ofenergy lost per hour hides the actual value of standby loss. FEA finds that the .determination of standby loss in terms of units of energy lost per hour can be accomplished by additional calculations which utilize the results obtained by the present test procedure. The determination of standbylossin term.:; ofthefraction of the heat content of the stored \\·ater above room temperature lost per hour. however. allows the test for standby loss to be run without maintaining

an exact 90° F. temperature difference**b~t\\·een** U1e stored water and the am- bient laboratory room temperature since t11c- te:-:L procedure compensates for am- bic-nt temperature and will yield U1e**~ame** n\lue of standby loss as long as tile- ambient room temperature is wiU1in the range specified. 65° F. 

### to 85° F. In order to directly determine standby loss in ab"olute terms of Btu per hour. the tc"t would need 

### to be run under condi

### RULES AND REGULATIONS

Uons of a constant room temperature of 70" F. with stored water 

### at 160° P. in order to obtain an exact 90°

.,..**~pera** 

### ture difi'erence. Alternatively, the 

### stored. water temperature would have to be adjusted dependingonthe laboratoryroom temperatureatthetimeoftests.

Thus, the**det~rminat!on** of standby loss in terJru. of the fraction of the heat contentof the stored waterlostper hour makes for a less burdensome test procedure than theonewhichwould haveti.> be developed if the suggestion that standby loss be determined in terms of units of energy lost per hour were to be adopted. In addition. it allowi; FTC to labelthestandbyloss in themaimersuggested if the FTC deems it appropriate. Therefore. the suggestion has not been adopted.

A comment was made that a calculation be included in the test procedure 

### to

· determine a costof operationfor a water

heateron standby

### tn termsordo!lars per month. FEA finds such a cost can be determined from the 

### test results of the current test procedure. Therefore, FTC

can adopt this proposal to determine a cost of operation of a water heater on standby as part of their water heater labeling program, i! they so choose.

Another comment suggested that a single test be conducted to determine both standbyloss andrecoveryefficiency. The test recommended consists of a 12- hour standby period followed by a draw period repeated enough tinles to provide acceptable accuracy. It was stated that the standby testproposed maynotcredit the savings to be expected from an electric ignition system and that recovery during dynamicconditions suchas a wa- ter draw schedule may be different than recovery from 70° F. to 165° F., as proposed in the static test. Although no testing with intermittent ignition has been conducted by NBS to date, preliminary testing with a reduced pilot input rate has shown energy savings for a 72- hour standby test. The question ofaccu- rately preclicting an energy saYings for electric ignitionalone seems tobea moot point since thatdesign option isnotcon- sidered economically practical unless it is accompanied by the use of a flue damper. In any event, NBS considers the test procedure as proposed to be suIficient to detectenergy savingsfor intermittent ignition systems. FEA concurs with the NBS position. Therefore, this suggestion has not been adopted.

10. MEASUREMENT AND CALCULATION OF RECOVERY EFFICIENCY A comment noted that a recovero.· efficiencyof 100percentis assumedfor electric water heaters with inlmerscd heatingelements in the calculation of standby loss yet a value for the recovery efficiency of an electric water heater with imnwrsed heating elements is calculated in a previous section. This apparent inconsistency results from the different methods used to calculutc recovery efficiency and standby loss between the electric and gas or oil fue!ed heaters.

The recovery efficiency or an electric
water heaterwith i..nmerscd heating elemeuls is very nf'.H to HIO percent since.

as**expl2.in~** in the sect.J<Jn or. standby loss, 

# a..• .Immersed heaWig element delivers practically 10!; per.cent of llle

# ·"Hergy mput 

### at th.<! 

### point. o! 

### use Ul**~.be** water. To make 

### a direct**r.neasure~:ient** of the recovery efficiency of such a water heaterwould be "Jery difficult. The procedure would require that the temperature of the water in the wa•er heater tank be determined very accurately. The !'ix thermocouple array that is required to beinstalled In the tank accordingto

### sec- tion :?.5 for the purpose of mea.surink water temperature is not sufficient f<:.•r the purpose of such a test. In fa-ct. attempts made 

### to measure the recovery efficiencyof anelectricwaterheaterwith this thermocouple array could result in valuesofrecovery efficiency greater than 100 percent due to the error introduced byvariationsinwatertemperaturewhich exist In the spherical portion at the bottom of the tank. An analysis would ila\'e 

### to be made of the geometry o! the tank and additionalthermocoupleswouldhave 

### to be used in order 

### to achieve the accu- racy requisite to directly measure re- covery efficiency. The requirements of making sucha directmeasurementwould result in a test procedure v;hich wou!d be unduly burdensome for a manufacturer 

### to conduct.

Instead of requiring that U1e reco\·ery efficiency ofanelectricwaterheaterwith immersed heating elements be determined directly. the test procedure prnvides for calculating the recoven• e..fiiciency as one minus U1e**~t.andby** lo.."Sei during recovery since standby loss isthe only energy loss for such water heaters. Thisindirectmethod fordeterminingre- coven· efficiency is more accurate than any direct method of detennination which would not be unduly burdensome.

The standby loss measurement procedure is the same for each type of heater. However. the calculation differs in that an assignment of 0.98 for the

.recoven· effciency. Er". is made for the electric water heater with immersed heating elements. Since one does not know the exact recovery efficiency for electric water heaters until the standby loss is measured and the standby less contains a correction 

### b8.sed on**reco...-e~·** efficiency. thereexiststwoequationswith three unknowns. It therefore becomes necessary 

### to assign a recovery efficiency in the standby loss equation. In the proposed t.est procedure. an assignment of 1.00 was made. The actual ...-alue or the reco\·ery efficiency is more likely in the range of 0.97 

### to 0.99. Therefore. in order to reduce the error introduced into the standby loss equation for electric water heaterswith immersedheatingelements. PEA has changed the assigned value for recovery efficiet1cy from 1.00 to 0.98.

One commentproposed that the "'·atcr heater tank should be preheatro for the purposes of performing the reco\·ery efficicncy 

### te5t since oil fueled heaten; are affected more bs a cold start**t~t** than either gas or electric heaters. Elimination or the tank preheating test reduced thetesttime and thecostof testing. :!'.'BS testir..g has re\·ealed that the cold start

FEDERAl l!EGISTER. VOL -12. NO. 192-lUi:SOAY, OCTOBER 4, 1977

### 5-Ul-t

procedure gives test results 2 percent 

### to 3 percent lower than if the tank were preheated for oil fueled water heaters. The preheated tank procedure ";\'Ould credit the recovery test with heat re- tained in the tank from the preheating of the tank. This does not represent ac- tual field conditions since heat input is notobtained free in actual use. However, the cold start test as proposed also does not represent actual use in the field. In the interestof reducing the time and the costs required to includea tank preheatingtest in the test procedure. the use of

a tank preheating test has not been adopted.

A comment statedthat thestatic tests, without drawing water for measuring recovery efficiency. are not sufficiently accurate for determining the recovery efficiency of gas oroil fueled waterheat-

ers. Tests at NBS using a typical withdrawal schedule have shown a good correlationbet.ween the static testmeas- urements and calculations compared to actual metered energy consumption for

a 16-hour withdrawal schedule. Therefore. no change to the static test procedure has been made.

A comment was made that 

### a calculation be included in the test procedure to determine 

### a cost of operation for a water heater during the recovery stage in terms of dollars per 1000 gallons of hot water delivered per month. Such a cost can be determined from the test results of the current test procedure. Therefore. FTC can adopt this proposal to determine a cost of operation of a waterheater on recovery as part of their water heater labeling program. if they

so choose.

11. POWER INPUT !>ETERMINATION As a result of the change made to the definition of a basic model of a water heater, a method for determining the power input for an electric water heater with immersed heating elements had to be developed. Section 3.2.2 of Appendix E of this ·subpart presents the method for making this determination. The method does not require that power input measurements be made. The manu- facturer's assigned design energy ratings for the immersed heating elements that

are installed in a water heater are used 

### to calculate the power input term. Although this means of determining the powerinputfor an·electric water heater with immersed heating elements is an approximation of the actual value, the

errorthatmay be presentwillhavelittle bearing on the two measures, recovery efficiency and average daily energy con- zumption, thatuse thepower input term in their equations, by the nature of the equations themselves. The values determined from these equations are sufficiently insensitive to error in thepower input term t-0 justify using an approximationforpowerinputandnotrequiring thatitbedirectlymeasured.

12. HOT WATER SuPPLY RATI!'G AND RECOVERY RATE The hot water supply rating test and the recovery rate determination that 

### RULES AND REGULATIONS

were part of the prop06ed 

### test procedure have been deleted. f:rom aie 

### test procedure on the basis that, in theJr present f9rm, they would make the 

### test procedureundulyburdf".nsome !ormanu- facturers of electric water heaters with immersed heater elements to conduct. Unlike standby loss, hot water supply raiing and recovery rate determinations

are very dependent on the actual wattageandlocationoftheimmersedheating elements installed in the water heater, the number of such elements installed, and the configuration of the auxiliary electrical system of the water heater whichcontrolstheoperationof theheating elements. Testing for hotwater supply rating and recovery rate would have to be done for all possible combinations of these factors which goes back to the problems associated with the proposed definition of a basic model of a water heater.

Comments were made that the hot water supply rating of an electric water heater with immersed heating elements could be predicted for all basic models of electric water heaters in much the same way thatstandbyloss could be predicted. No hot water supply rating prediction scheme was presented. Neither was any data submitted from which .a hot water supply rating prediction scheme might be developed. Without a hot water supply rating prediction scheme and without test data to verify that a particular prediction scheme is sufficiently accu- rate. FEA cannot consider making such

a modification to the hot water supply rating test at the present time.

In the case of recovery rate, the power input to thewater heater must be determined. The current procedure for determining power input for electric water heaters with immersed heating elements is to accept the design value assigned by the manufacturer. Unlike recovery efficiency and average daily energy con- sumption. recovery rate is sensitive t-0

error in the power input term and the approximations of power input determined in section 3.2.2 would introduce 

### a potentially significant error into the determinationofrecoveryratewhichwould be unacceptable.

FEAfinds that in the absence of a hot water supply rating prediction scheme and a recovery rate prediction scheme. the hot water supply rating test and the recovery rate determination must be deleted from the water heater test procedure at the presenttime.FEArecognizes that this deletion will eliminate an important measure of water heater performance from the test procedure. FEA also recognizes that without a hot 

### water supply rating. or some other measure of hot water delivery perfomrnnce. the**t~t** procedure leaves a consumer '\\ith less than the best information to select a waterheaterwhichwill satisfyhis needs. Therefore. FEAplans to investigate prediction schemes for the detem1ination ofhotwater supply rating orfor thedetermination of some other measure of hotwaterdeli>·ery performar.ceforwater heaters. The goal of this im-estigation will be to proi.ide consumers '\\ith a use- !ul measure of hot water delh•ery performance for 

### water heaters while not Jmpasing unduly burdensome 

### test re- quirements on any segment. of the water heater industry.

FEA hereby invites the water heater industryandanyotherinterestedparties to provide input to FEA concerning this proposed investigation. This investigation v:ill be completed by December l, 1977. In itspresentform. nothingin this fin:tl testprocedureprohibts a manufacturer from makin" representations con- cerning the hot water**~upply** rating of anyofhis waterbeaterproducts.

13. SYMBOLS USED IN THE TEST PROC!:DUU: EQUATIONS Coments were ma.de that the symbols used in the equations of the proposed test procedure exhibited Inconsistencies which made Interpretation o! the equations difficult. Further comments rec- omended that the symbols used be revised in accordance v.ith standard practices. FEA concurs. The equation.<: of section 4 of Appendix E o! this subpart reflect the recommended**change~.** 14. TESTING CONDmONS Comments 

### an section 2.5 of the proposed test procedure pointed out that the requirement that thermocouples be installed along the centerline of the waterheater tankmaylead t-0 confusion sincefor many gas andoilwaterheaters the flue is located at the centerline of the tank. Section 2.5 has been revised 

### to eliminate this potential source of confusion.

In response to a. comment concen1ing the hook-up of the water heater inlet andoutletpipeconnectionstowatersupply and delivery pipes, the test procedure has been revised to require a heat trap type of configuration for •rnter heaters with vertical inlet and/or outlet pipe connections.

IS. CALCULATIONS OF THE ENERGY FAC!OR

The proposed test procedure did not clearly 

### state the appropriate section of Appendix E t-0 be used in the calculation of the energyfactor insection 430..22•e 1• Thisresultedin misinterpretation oft.he


### useoftheaveragedailyenergy

### consumption. Section 430.22Ce> has been cor- rected t-0 properly reference the apnro- 

### priate section ofAppendi.'C E.

16. INDIRECT ENERGY CONSUMPTION
A comment 

### was made that the 

### test procedure should 

### account for the increased operating time and energy con- sumptionof

### a furnace or airconditioner which is caused by gas and oil ·water heaters. The increased energy 

### consumption arises from the fact that most gas and oil water heaters utilize interior air for combustion and draft maintenanc-e which is then vented out of the hou.<>e and replaced by the infiltration of ex- terior air which mu.st then be heated by the furnace or cooled by t.he air con- ditioner depending on the sea.son. TI.re loss ofinteriorconditioned air contimir:<

ev·en when the waterheat<'r is not in the combustionstat<'duetothenatural draft of the flue unless the water heatrr 1..-

ffDU!Al REGISTER, VOL 42, NO. 192-!UESDAY, OCTOl!Elt 4, 1977

### RULES AND REGULATIONS

equipped with a fiue damper which is usually not the case. tominimizethetestingburdenon manu- facturers. and dishwashers used both 

### these terms in a manner that could be confusing. and the Ianguage prescribed today is intended

### toeliminatethispossibility. PEA is sensitive to such hidden costs of operation and will incorporate them whenever they are of sumclent magnitude to warrant theburden of additional testingdesignedtomeasureandquantify such costs. Test procedures prescribed under sec- tion 323 of the Act are intended ultimatelytobeused,for example,forlabelingunder

### section 324, formonitoring the progress of manufacturers toward 

### accomplishing the energy efficiency imUntil.a labeling rule has been implemented pursuant to section 324. manu- facturers are not required to test unless they choose 

### to make representations re- garding 

### a measure of energy consumption. It. should be emphasized L'iat the test procedures prescribed today apph· only tothe initialratingof a basic model. Secondary costs havebeen included in the final testprocedures for dishwashers and clotheswashers, and inthe proposed test procedures for dehumidifiers and furnaces. however. FEA has decided not to incorporate these costs in the water heater test procedure at this time. FEA bases its decision on data forwarded by NBS which indicates 

### that thesecondary costs representonly2 percentofthe cost of operation of 

### a water heater and that the testing burden to account for such costs would be large. Furthermore, NBS has reported to FEA that the potential dollar savings achieved by the use of a direct vent system, which utilizes exterior air rather then int.erior air and thereby avoids imposing additional costs

on furnaces or air conditioners, is not sufficient to pay for the 

### cost of such devices. Only when 

### direct vent systems are combined with preheating devices do theybecome economicallyviableand the test procedure, as currently

### written, will

measure most of the increased efficiency of water heaters 

### so eqUipped. Therefore there is little justificationfor mOdifying the testprocedures at t.his time.

. Anyone with information indicating i that direct vent systems alone are cur-

rently economically justified for water heaters or that the cost a.<;Sociat.ed with the loss of interior conditioned air is greater than 2 percent of the cost of operation of a gas or oil water heater is hereby requested by FEA 

### to submit such information. Should the assumptions on which FEA has based its· decision be shown to be incorrect, PEA will consider modifying the water heater test procedure to incorporate the secondary costs ofoperation.

17. PRIMARY ENERGY LABELING While a comment suggested primary energy labeling, i.e., taking into consideration the energy consumed by a power plant

### t-0 producetheamountofelectrical energy consumed by an appliance, the Energy Polley and Conservation Act specifically requires that the estimated annual operation cost of an appliance be calculated in terms of the retail cost of energylikelyto beconsumedinrepresentative 

### use. Therefore, this suggestion has not been adopted.

18. NUMBER OF UNITS TO BE TESTED Some comments expressed objections to the samplingprovisionforwaterheat-

ers. Proposed section 430.23<e> provided for sampling of each basic model to be tested when testing of water heaters is required by theAct or by program regulations of agencies :responsible for administering the Act. 'Ibis provision was intended both to provide an acceptable level of assurance that the test results ::ire applicable to 

## an units of a basic model for which testing is required and provementtargetsundersection 325, and for enforcement testing under section 326. These aspects of the appliance program have not. however, been implemented. It is quite possible that the objectives of appliance testing under each of these parts of the program, as well as the instructions as to how a test procedure should be applied. e.g., sampling of production tmits. may differ. FEA. NBS, and FTC are continuing to evaluate the appropriate method or methods for sampling the units 

### t-0 be tested in order 

### to comply with the statute and satisfy all of thedi1ferent elements of the appli-

anceprogram.

While the various parts of the appli-

ance program Identified above a.re not in effect at this time, section 323Cc) or the Actprovides:

Effective90 days after a testprocedure rule applicable to a. covered product is preecrtbed underthls secti.on, nome.nu!a.cture'r, dlstr:lbutor, 'retailerorprivatelabeler maymake any representa.tion-

(1) In writing (Including a representation

ona label),or

(2) In any broadcast advertisement, respecting the energy consumption of' such product or cost of energy consumed by such product. unless suchproduct hasbeen tested In accordance with such test procedure and such representation fairly discloses the re- sults or suchtesting.

In order

### toeliminate the problem discussed above associated with a general samplingprovision, § 430.23 hasbeenre- served in the :final test procedure, and samplingrequirementswhich "apply only for purposes of advertising have been reorganized 

### into § 430.24<e> of the final testprocedures.Section430.24.Ce) is similar toproposed§ 430.23Ce). butcontains several revisions. Mostnotably, the units tested may now be either representative ofproductionunits, oractualproduction units. This change is intended to reduce the burden which might be caused by requiringpost-productionratingofbasic modelsineveryinstanceoftestingpursuanttosection323(C) oftheAct. 19. MISCELLANEOUS After careful consideration of all of the comments and further consultation with NBS and FTC, FEA has incorporated some minor changes in the proposed test procedures in the final rule thatarenotdiscussed above.

C. REGULATIONS PRESCRIBED

1. TEST PROCEDURES The test procedures for water hcat(·r:' prescribed today are included in SubpanB and are substantiallythe same as thooe proposed with the exception of the elimination of the hot water supply 

### rating test and the recovery rate determination. As with the proposed procedures. test methods and conditions incorporate the approachcontainedinAmericanNationalStandardsInstitutestandardZ21.- 10.l-1971 and C72.1-1972. The test procedure 

### aJso uses the definition of the term"oil"containedintheAmerican Society for Testing and Materials CASTM• D396-71. Subsequent amendments of either the standard or the supplement ma(ie by the standard setting organizationwillhavenoeffectonthetestprocedurewhichcanonlybeamendedbyPEA.

Under the requirements of section 12 <c> of the Federal Energy AdministrationActof 1974 <15 U.S.C. 761 etseq.l as amended by section 9 of the Federal EnergyAdministrationAuthorizationAct of 1977 <Pub. L. 95-70), the Administrator is to consult with the Attorney General and the Chairman of the Federal Trade Commission concerning the impact on competition o! any rules prescribed by

### FEAwhich utilize or intorporate any commercial standards.

The Administrator has transmitted copies of the :final 

### test procedures for water heaters. which incorporate the abo\"e mentioned commercial standards. to the Attorney General and the Chair-

man of the Federal Trade COmmission for their comments concerning the im

### pactofsuch standardson competition in accordance with section 32<c>. Neither individualhasanycommentsnordothey 

### recommend again.st the incorporation or 

### use of these commercialstandards in the final testprocedures forwaterhes.ters.

2. GENERAL PROVISIONS In addition, certain technical changes have been made in sampling language. Specifically,thereistobe90percentcon- fidence thatthetrue meanof any

### meas-
ure of the basic model lies within ±10 percent of the mean of such measure of the sample. Comments pertaining to several prop05ed test procedures criticized thelanguage of the proposed sam- pling provision. These comments suggested that 

### a sampling proYision should reier to the estimate of U1e mean rather than 

### to the true mean. FEA has considered this suggestion and has determined that the language prescribed today is

moret.echnlcnUy correctbecausethestatistical measure "estimate of the mean

.. and "mean of the sample

.. are generally

con.

.**~uered** tobe identical. The final test procedures for room air conditioners Prescribed today are certain definitions applicable to water heaters which "'·ere pre\iously propos·**.~** in Subpart A (41FR19977.May 14. 1976: 42 FR 15423. March 22. 1977l. Comments were re- ceh"ed regarding these definitions and the issues and changes ha\·e been discussed. earlier in this notice. All dcllnitions appearing in section 321 ofthe Act

wereincorporated byreference int-0 SubFtDIEl!Al l!EGISUI!, VOL 42, NO. 192-TUESDAY, 

### ocrogn 4, 1977

### part A of Part 430 in the final test. 

### procedures for room air 

### conditioners issued May24, 1977 

### < 42FR

### 27896, Junel, 

### 1977>. Detlnitlons of the terms "Administra

### tor", "Btu" and "FEA" 

### were also 

### incorporated intoSubpartA 

### bythe:ftnal

### room airconditioner

### testprocedures.Thedefinition of the term "basic model" for water heaters has been changed, 

### as discussed above. Definitions of the terms "cutout" and "designpowerrating"have been added.

It should be noted that some of the definitions prescribed today may be applicable to test procedures for other appliances. While these definitions are final. comments to the effect that any 

### of these definitions are inapplicable 

### to a. particular appliance will be evaluated to determine whether amendment ormodification is appropriate.

3. APPLICATION OF TEST PROCEDURES 

### As discussedpreviously, thefinal water heater test procedures prescribed today must be applied before representations regarding a measureof energyconsumption can be made. Because the purposes and needs of tha different elements of the nppliance program, such 

### as labeling

ortargets,vary, applicationofthestandard 

### test methodology prescribed today may dit!erinsomerespectsfor eachprogram element. Instructions on how to apply thestandardtestmethodology will be proposed for comment as these other )element of the appliance program are

developed.

The requirements**of~** 

### 430.24<e) of the final regulations apply until such time as final labeling requirements for a particular measure of energy consumption and the associated 

### test procedure application provision are prescribed. After that time, all representations regarding

a measureofenergyconsumptioncovered by a labeling rule must be the same 

### as representedonthelabel.

D. UNIT COSTS OF E:s-ERGY 

### Under section 323<b) (2) of the Act, FEA 

### is to 

### provide manufacturers information as to 

### the representative aver- age unit costs of energy. This information was provided by notice issued July 11, 

### 1977 (42 FR 

### 36549, July 15. 1977). E. PREEMPTION 

### RULES AND REGULATIONS

(Energy Policy and COn.l!i0ne.Uon Ad, Pub.L.**~163,** a.s amended by Pub. L.**~** Jl'ederal Energy**~Uon ~of**  1974**~** L. 93-275, ms amended by Pub. L. 

## ff-385; E.0.11790, 39FB.23185.)



### Issued in Washington, D.C., 

### Sept.em- ber27. 1977.

ERICJ. PYGI, Acting General Caunsel, Federal Energy Administration.
1. 

### Section 430.2 is 

### amended by adding paragraph 15) as part o! the definition of "basic model" and by adding in ap

### propriate alphabetical order the definition of "immersed heating element" and "water heater" to 

### read as follows: § 430.2 Definilions.



### "Basic model" means all units of a given type of covered product. or class thereof, manufactured by one manufacturer and:


## • <5> with respect to water heaters, which have the same primary energy
source and which, with the exception of immersed heating elements, do nothave anydifferingelectrical,physical,orftmctional characteristics that affect energy consumption. 

### "

"Immersed heating element"' means
an electrically powered heating device whichis designed to operatewhiletotaJly immersed in water in such a manner that the heat generated by the device is imparted directly to the water. 

## • • • "Water heater·• means an automatically controJled thermally insulated vessel designed for heating water and storing heated water, which utilizes either oil, gas, or electricity as the fuel

or energy source for heating the water, which is 

### designed to produce hot water ata temperatureoflessthan 180°F., and which includes the foJlowing products:

la) "Electric water heater" 

### means a water heaterwhich utilizes electricity as the energy source for heating the water, which has a manufacturer's specified energy input rating of 12 kilowatts or less at a voltage no greater than 250 volts. and which has a manufacturer's specified storage capacity of not less 

### than 20 gallons nor more than 120 gal- lons. 2. 

### Section 430.22 1s 

### amended by adding 

### a paragraph <e>. 

### to read 

### as follows: § 430.2% Tat procedures !or**mea~ur..,;** ofenergyeoru;umption. 

## " 

# .. 

# .. 

# .. .. <e> 

### Water Heaters. <1> 

### The estimated annual 

### operating 

### cost for water heaters shall he

### m For a 

### gas or oil water heater. the product of the representative average 

### use cycle of 365 days per 

### year 

### times the


### sum of 

## <A> The product of the average daily auxiliary electrical energy con- swnption in kilowatt-hours per 

### day, determined according 

### to 

### section 4.5.1 

### o! Appendix E 

### of this 

### subpart, times the representative aveni.i'e unit costof electricity in dollars Pe!' 

### kilowatt-hour 

### a.5 provided by the Administrator 

### plus lB> The product of the average daily gas 

### or oil energy consumpUon in Btu 

### per day. detennilled a.ccord!Dg 

### to section 4.5.2 

### of Appendix E 

### o! this subpart, times the 

### representative average unit cost of gas
or oil, as appropriate, in dollars per Btu

as 

### provided by the 

### Administrator. the resulting product then 

### being rounded off

### to thenearestdollar per

### year.

Iii) 

### For 

### an electric 

### water heater, the product of the 

### following three 

### factors: 

## <A> Therepresentativeaverageusecycle of 365 days per year, CB> The average daily energy consumption in kilowatthours per day, deterinlned according to section 4.5.4 of Appendix E 

### of this 

### subpart, and 

### <C> The representative aver- age unitcost of electricityin dollars per kilowatt-hour as provided by the AdIninlstrator, the resulting 

### product then

., being rounded off to 

### the nearest dollar per year. <2> The energy factor for water heat-

ers shallbe- (i) 

### For 

### u gas 

### or oil water heater, 

### the quotient of the daily water heating en- ergy consumption determined according 

### to section 4.3 of Appendix E 

### of this subpart divided by the product of the a.:erage dallyenergyCOl:'.swnption as determined according to section 4.5.4 of Appendix E 

### of this subpart times 3.41::? 

### Btu per kilowatt-hours. the resultini:: quotient then being rounded 

### on: to the nearest 0.01. <iD For an electric water heater. the quotient of the daily water heating en- ergy conswnption determined according to section 4.3 of Appendix E 

### of this 

### subpart

### divided by the 

### product of the 

### a'-er- <b) "Gas water heater·• means 

### a. wa- ter heater which utilizes gas 

### a.s the 

### en- ergy source forheating thewater, whkh has a manufacturer's specified energy input rating of 75,000 Btu per hour or less, and which has a manufacturer's specifiedstoragecapacityofnotlessthan 20 gallons nor more than 100 gallons. . age daily energy consumption 

### as determined according to 

### section 4.5.4 of Appendix E 

### of this 

### subpart times 

### 3,412 Btu per 

### kilowatt-hours., the resulting quotientthenbeingrounded off

### tothenear- est 0.01. Today"s rulemaking prescribing final test procedures for water heaters supersedes any State regulation 

### to the extent required by section 327 of the Act. Pursuant

### tosection 327. allStateregulations which provide for the disclosure of information with respect 

### to any measure of energy consumption of water heaters

or which provide for any euergy efficiency standard or similar requirement v.ithrespecttoenergyefficiency orenergy
use of water heaters must now employ test procedures identical to those specified in today"s finalrule.

In consideration of the foregoing, Chapter II 

### of Title 10. Code of Federal Regulations is 

### amended as set forth below. elfecti.-eNo.-ember 8, 1977. Cc) "Oil water heater" means a water heater which utilizes oil as 

### the energy source for heatin6 the water, which has

a manufacturer's specified energy input rating of 103,875 Btu per hour or less, and which has a manufacturer"s speci

### fied storage capacity of 50 gallons or less. (3) 

### Ot.ber useful measures of energy consumption for water heaters shall be 

### those measures 

### or energy consumption for waterheaterswhich theAdminist.rator determines 

### are likely to 

### assist con- sumers in making 

### purchasing decision.!< and which 

### are derived from the appli- 

### cation of Appendix E 

### of this 

### subpart.



# .. " 3.

### Section**4~0.24** Is

### amendedbyadding

a paragraph Ce), to read asfollows:

li'IDIERAL lllEG!STER, VOL 42, NO. 192-TUESDAY, OCTO!!Elt 4, 1977

### :§ ·130.2

### i Rl'presenlulions regarding nwasurl's o! energy consumption.

e


### <e> Water heaters. (1) 

### Except as provided in paragraph <e> (3) of thls sec- tion. no manufacturer, distributor, re- tailer. or privatelabeler of waterheaters !nay make any representation with re- spect to or based upon a measure or measures of energy consumption described in § 

### 430.22Ce> unless a sample of sufficient size of each basic model for which such representation is 

### made has been tested in accordance with applicable provisions of this subpart such that, for each such measure of energy cm1- sumption, there is 

### at least 90 percent confidence that the true mean of such

measuresofthebasicmodel ls

### within ±10 percent of the mean of such measures of thesample.

•2l 

### Thesampleselectionforparagraph <el <l> 

### of this section shall be comprised of units which are production units, or which are representative of production· units, of the basic model being tested. (3> Whenever a rule applicable to water heaters has been prescribed under section 324 of the Act, this paragraph shall not apply 

### to any label covered by such rule. and all representations of any measure of energy_ consumption covered by such rule shall be identical 

### t-0 the

measure of energy consumption on the label.



# .. ..

1, 

### 4. SubpartB ofPart430 is amended to add an Appendix E, to read as follows:

APPENDIX E--UNIFOR::'J: TEST METHOD FOR

l\iEASURING THE ENERGY**coxsu~tPrION'** OF
WATER HEATERS

I. Definitions.

_, 1.1 "Cutout" means the moment in time when a water heater thermogtat !l:is acted to reduce the energy or fuel input to the heating e1ements or burners to a minimum.

1.2 '"Design Power Rat!ng" means the nominal power rating that a water heater manufacturer assigns to a particular design of water heater heating element, expres"Cd in kilowatts.

1.3**~Heat** Trap·· means a device which can be Integrally connected, or independently at- tached, to the hot of cold water pipe connections of a water heater such that the device wlll develop a thermal or mechanical seal to minimize the recirculation of water due to natural thermal convection between the water heater tank and its water supply pipes and thereby reduce the heat Joss to the en- vironment from the hot water stored In the water heater.

1.4 "Recovery Efficiency·• means the ratio of the beat Imparted to the water to-

(a) ·in the case of an electric water heater, the energy input to the heating elements during the period that the water tempera- ture is raised from the Inlet temperature to the final temperature with the tank filled to capacity.

(bl In the case of a gas or oil v.-ater heat-

er. the heat content o! the fuel consumed by the burners during the period the.t the v.-ater temperature ls raised from the Inlet temperature to the final temperature with t.he tank filled tocaps.city.

1.5 "Standby loss·· means the ratio of the heat 1068 per hour to the heat content of the stored. water above room teniperature. 

### IUlES AND REGULATIONS

e. !Int conditions. 2.1 Installation. Install the water heater according to the manu!e.cturer's d.lrectlon.11

on e. %.-1.nch-thk:k plywood platform supportedby th.re&2 x 4-lnchrunners. For wa.ter heaters without Integral heat traps and with vertical Inlet and outlet pipe connections, lnsmU the Inlet and outlet piping with heat traps at the Inlet and outletports. Such heat traps may be made using pipe fittings such

as elbows connected In such a fashion that the inlet and outlet piping make vertically upward runs just before turning downward to connect to the 1nlet and outlet ports. For water heaters with Integral heat traps or with horizontal Inlet and outlet pipe con- nections. install the Inlet and outlet piping in any convenient fashion.

Sufficient clearance shall be allowed between the water heater surface and the piping (Including heat traps, If any) so that when the piping Is Insulated as specified below, the insulation does not contact any water heater surface except at the location where

.the pipe connections penetrate the water heaterjacket. Insulate the water heater inlet and outlet piping (Including heat tmps, If any) for a length o! !our feet from the connection at the water beater with a materl:il having a thermal resistance (R) vn!ue of not less than 

### OF 4 ··--·· --·-·

lituift'-hr

2.2 Flue requirements for gas and oil u:atcr heaters.

2.2.l Flue requirements fD'T" gas water heaters. For a gas water heater having a vertically discharging draft hood outlet. a 5 foot vertical flue pipe extension having a diameter equal to the largest flue collar size of the draft hood shall be connected to the draft hood outlet. For a gas water heater having n horl7..ontally discharging draft hood outlet. a 90 degree elbow having a diameter equal to the largest flue collar size of the draft hood shall be connected to the draft hood outlet. A 5 foot length of flue pipe shall be connected to the elbow and oriented to discharge vertically upward. Perform au tests with the natural draft established by thl.s length of flue pipe. Direct vent gas water heaters should be lnstaUed with vent- ing equipment as specified ln the manu!ac- turer·s instructions: however, the vertical length of the flue pipe shall be no greater than 5 feet. 

### 54117

68 and 72" F .• and at a gauge preg;ure of between 40 pounds per square inch and the maximum pressure s.peci!loo by the manu- facturer !or the water heater under test. I! the water supply pressure varies outside of these llm!ts during testing. the heater shall be Isolated by use of a shut-olf valve in the supply Jlne with an expansion tank installed In thesupply llne downstream o! the shut-olf valve. There shall be no shut-olr means between the expansion tank and the water heater Inlet.

2-4 Energy Supply. 2.4.1 Electrical supply. For an electric water ht>ater and !or the aux1!1ary electrical system. 1! any, o! an oil or gas water heater, maintain the electrical supply voltage to within :!:l percento!thecentero! the voltage range specified by the v.:aterheater manu!actureron the water heaternameplate throughout the entire operating portion ofeach te;t.

2.4.2 Ga.q supply. 2.4.2.2 Natural gas. For a gas water heater utilizing natural gas, maintain the gas »Upply at a normal Inlet test pressure imme<llately ahead o! all controls at 7 to 10 inches o! water column. If the water heater ls equipped with a gas appliance pressure regulator, the regulator outlet pressure at the normal test pres5ure shalt be approximately that recommended by the manufacturer. All burners shall be adjusted to achieve an hourly Btu rating that Is within :!:2 percent of the hourly Btu rating specl.fled by the manufacturer. Use natural gas with a higher heating value o! approximately 1.025 Btu per standard cubic !oot. Determine the actual higher heating value. Hn. in Btu per standard cubic foot, !or the natural gas to be used in the test, with an error no greater than :!:l percent, and use that value !or a.JI calculations Included herein. Alternath·eJy. the test can be conducted using

..l>ottlednatural gas of a higher heating**va~ue** of approximately 1.025 Btu per standard cubic foot as Jong as the actual higher beating ·mJue of the l>ott!ed natural gas has been determined with an error no greater than :!:1 percent as certified by the supplier.

2.4.2.2 Propane gas. For a gas water heater utilizing !400pane•. maintain the gas supply at a normal in!et test pressure immediately ahead or all controls at 11 to 13 inches of water column. If the water heater Is equipped with a gas appliance pressure regulator, the regulator outlet pressure at normal test pressure shall be approximately that recommended by the manu!acturer. All burners shall be adjusted to achieve anhourly Btu rating that Is within ±2 percent or the hourly Bturating speclfled by the manufacturer. Use propane with a higher beating \"alue of approlt.lmately 2.500 Btu per stand· ard cubic foot. Determine the actu!Ll higher heating value. H,, In Btu per standard cubic foot. for the propanP. to be used tn the test. with an error no greater than ±1 percent. and use that value fur all calculations included herein. Alternatively, the test can be conducted using "bottled

.. propane o! a higher heating \"alue of approximately 2.500 Btu per.standard cubic foot as long s.s the actual higher hea;.ing "\"alt:e of the bottled propane has been determined with an error
no greater than := l perc-cnt as c-ertlfted by the supplier.

,. 2.4.3 Of! supply. For an '011**~·ater** heater 2.2.2 Fine requirementsfD'T" oil water heot-

crs. For an oil fueled water heater. establish

a draft at the flue collarequivalentto atleast 0.02 Inch of water column during periods of burner firing. For an oil water heater having

a vertlca11y discharging draft hood outlet, establish the draftby usinga sufficientlength of flue pipe connected to· the water heater flue outlet and directed vertically upv;ard. For an oil water heater having a horizontally discharging draft hood outlet. a 90 degree elbow having a diameter equal to the largest flue collar size of the draft hood shaJJ be connected to the draft hood outlet. A length ot flue pipe sttftlclent to estab!Lsh the draft shall be connected to the elbow fitting and oriented to discharge vertically upward. Directventoil waterheaters shouldbe Installed with venting equipment as specl.fled In the manufacturer·s instructions. When celllng height Jlmlts the use ora sufficient length of vertical flue pipe for an oil water heater. a mechanical draft inducer may be used during periods ofburnerfiring to establish the spe<:- ifled draftattheflue collar.

2.3 Water supply. Du.ring the entire test maintain the water supply to the water heater Inlet at " temperature of between _utilizing fuel oil. ms.lnt.\ln an uninterrupte<l supply or fuel ol! to the water heater during the entire operatingportion of the**t~t** cycle. Use fuel oil with a heating "1"8.lue or approximately 138.500 Btu per_ gallon. Determine the actual hes!tng value. 11•• in Btu per gallon for the fuel oil to be used in the test. with an error no greater than 

### =: 1 per- cent. and use that value for all cstculatlon.q

fla)fllAL lili:GISTEI, VOL 42, NO. 192-TIJIESDAY, OCTOl!IE!t 4, 1977

### 5·1118

Included herein. Alternntlv1.'I\", the tests cnn be conducted using a tested·fuel oil wtth a ct-rtllled higher heating value of approximately 138,500 Btu per gallon ns long 11.11 the actanl higher heating value of the test fuel

011 has been determined With an error of no ,;renter thnn ±1 percent as certlfie<l by the supplier.

2.5 Therm0<.'0uple installation. Install six thermocouples In.side the water heater tank. Pvsttlon each thermocouple measuring junction along a vertical line at the level of the center horizontal plane of each of six non- overlapp\ng sections or approximately equal volume !rom the top 1:o the bottoJn of the tnnk such that each thermocouple ls sur- rounded by water and as far as possible from nny heating element, anodic protective device, or a water tank or flue wall. The anodic protective device may be removed In order to Install t.he thermocouples and all testing mny be carried out with the device removed. Install thermocouples In bo!;h the coldwater Inlet pipe and the hot-water outlet pipe not more than sL"t Inches from the connections to the water heater, or, where thooe connections are Inaccessible, at thG closest nccesslble point to those connections. Install In the test room a thermocouple w.lth junction shielded against direct radiation from the water heater and positioned at the vertical mid-point or the henter at a perpendicular distance of approximately 24 inches from the surface of the water heater jacket. Provide an associated tempernture mensure- ment and Indicator system to assure thatthe temperature indicated for the thermocouple locntlon ls within ± 1• F. of the actual temperature at that location.

2.6 Setting the tank thermostat. Starting with a tank of unheated water. initiate normal operation of the water heater. After cutout, determine whether the maximum valueofthemean tank temperature Is Within the range of 160° F. ±5° F. I! not. turn off the water heater, adjust the thermostat, empty the tank and refill with unheated water. then inltlnte normal operation of the water heater, and once again determine the maximum mean tank temperature after cutout.Repeat this sequenceuntil themnximum

mean tank temperature after cutout ls w.lthin the range of 160° P. ±5° F., at which time the thermostat Is properly set. If a water heater has two thermostats. the thermostat which controls the upper heating element shall be set first to yield a m!l.l<imum water temperature of 160° F. ±5°. F. as measured by the topmost tank thermocouple after cut- out. The thermostat which controls the lower heating element shall then be set to yield a maximum mean tank temperature of 160° F. ±5°P. aftercutout.

2.7 Fuel or energy consumptic-n measurement. Install one or more instruments which

measure. as appropriate. and with an error
no greater than ±1 percent. the quantity of electrical energy. 'natural gas. propnne or**ft~el** oil consumed by a water heater. Electrical energy consumption ls to be expressed In imits of kilowatt-hours. Natural gas and propane consumption shall be expressed In units of standard cubic feet. I.e.• measured cubic feet corrected to standard conditions of 60' F. temperature and 30 inches of mercury column pressure. Fuel oil consumption Is to be expressed in units of gallons. Also Install one or more Instruments which

measure. as approprl.ate. and With an error
no !'Teater than :=t percent. the rate of electrical energy. natural gas. propane or fuel oil consumption by a water heater. The rate of electrical energy consumption shall Ile ex**pr~ed** In units of kilowatts. The rate of -natural gas and propnne consumption shall 

### RULES AND REGULATIONS

be expressed In units of standard cubic feet**p~r** hour. The rate of !uel oll con6Umptlon shall. be expressed in unit.a of gallons per hour.

2.8 Room aml:fent temperature. Maintain the ambientair temperatureof the testroom between 65° F. and 85" P. at all tlmes during the test, as measured according to section 3.5. The nmblent air temperature during these tests shall not vary more than ±7" P. from the average ambient air temperature determined as the arithmetic average of t:l:le air temperatures measured periodically at Intervals no greater than 15 minutes throughout the duration of the test.

3. Test procedures and measurements. 3.1 Tank storage capacity. Determine the storngt- capnclty, V. or the wnter heater under test, In gallons, according to the method specified In section 2.26 o! the Amerlcnn Natlonnl Standard for Gas Water Renters, Volume I, dcslgna'ted ANS Z21.10.l-1975.

3.2 Power input determination. 3.2.1 Pmcer input determination for gas and oil water heaters and electric water heaters with. other than tmmersed heating el$-
ments.Inltlnte normal operation of thewater heater, and by using the npproprlate Instrumentation specified In section 2.7 and the approprlnte fuel heating values of section 2.4, det.ermine the power Input, P, to the mnin burners (Including p!lot light power. If any) or heating elements of the water heater under test, In Btu per hour or kllowntts, as aproprlate. In addition, determine the power Input, pr to any ·auxillary electrical system of a gas or oil water heater when the main burners are In operation, in kllo-.vatts; and the power input, p,, to any auxlllary electrical system of a gas or oil water heater when the main burners are not In operation. In kilowatts.

3.2.2 Power input determination for electric water heaters with. immersed heating elements. The power input, P, to the beating element of an electric wat.er heater with

one immersed heating element sbnll be taken to be the design power rating of the heating element. For an electric water heater with dual !nunerscdheating elements. the power input. P, to the heating elements shall be taken to be the nrithmetlc mean of the design power ratings of the beating elements, If, In characteristic operation of the water heater, only one heating element will be energized at any time; otherwise, P shall be taken to be the sum of the design powerrafJl.ngsoftheheatingelements.

3.3 Recoi•ery efficiency. 3.3.1 Recovery efficiency for gas an4 oil water heaters and electric water heaters 1aith other than immersed heating elements. With the water heater turned off, fill the tank with water and eliminate any residual air remaining in the tank. If the mean tank temperature ls constant and w.lthin 70• F.:=2• F., record the mean tank temperature, initiate normal operation of the water heater. and begin measuring the fuel or en- ergy flow to the burners (including pilot light fuel if any) or heating elements of the water heater using the appropriate instrumentatlon specified in section 2.7. After cutout determine the maximum mean tank temperature and record the total fuel flow. Q•, for a gas or oil water heater. or the rot.al electr!rol energy flow, 

### z•. to the hentlng ele- ments of an electric water heater, from lnitlntlon to cutout. Record the temperature difference. 11.T,. obtained by subtracting the initial from the finnl ma.'<imum mean tank temperature.

3.3.2 Recovery efficiency for electric water l1catcrs 1cith immersed heating elements.The recovery efficiency for electt-lc ..-ater heaters wlt.h Immersed heating elements Is derived :rrom the results of the stan•.. y loss**t~t.s** of section3.4.2.

3.4 Standby loss. 3.4.1 Standby loss for ga'J and ,,;/ u·at...-r heaters and electric tearer heaters tc!th orlier than immersed heating dem.ents. _F..i;t.abl!sh nOl"lllA! water he.at.er operation within the mutmwnmean tank temperature within the rall€e specified in section 2.6 and with all air ellminated from the tank. Begm the standby 1065 test immediately aaer cutout. At the begmning of the standby l= tesi: record the time, the me:i.n tank temperature. the ambient air temperature, and begin measuring the fuel or energy flow 'to the burners (lncludlng pilot light fuel 1! .anyJ

or hentlng elements of the water heater u.-;- lng the appropriate instrumentation specified In section 2.7.

At the end o! the first 15 mJnute int.en-al and at the end o! each .subsequent 15 minute Interval following t.he beginning of the test. record the mean tank temperature and the ambient air temperature. Continue these measurements until the end o! a 48 hour period unless a main heating element or burne1' Is on nt that time, ln which case. continue these measurements until the first subsequent cutout. When the test is terminated, record the total :ruel fiow, Q•. !or a
or oil water henter. or t.he total electrical energy flow, 

### z,, to the heating elements of

an electric wnter heater, !rom the beginning to the end of the test period. the final mean tank temperature. the final amblent air temperature, and the tlme duration, t. of the standby losstest. inhours rounded of! to the nearest tenth o! an hour, which elapsed from the beginning to the end of the test period. Calculate the average of the recorded values of the mean tank temperatures and of the ambienta1r temperatures taken at the end of each time interval. including in eaci:l

case the initial and final values. Determine the difference, t.T,. between th6';e two aver- ages by subtracting the latter from the former. and the difference. .:.T.. between the final and Initial mean tank temperatures by subtracting the latter from the former.

3.4..2 Standb11 Ioss for electric icater heaters with. immersed heating elements. All water heaters to be tested must be equipped with Immersed heating elements that have a design power rating o! 4,500 watts unless such a design powerrating exceeds the mnxl-

mum design power rating specified by the manufacturer for the water heater to be tested, In which case the standbv loss test will be conducted with the wai.er heater equipped with immersed heating elements of

a design power rating equal to the manu- facturer·s specified maximum design power rating. All waterbeaters capable ofoperating with dual immersed heating elements will be equipped and tested with dual immersed heating elements of equal design power rating in accordance with the provisions specified above. Tests shall be oonducted in accordance with the same**p~dures** as those specified Insection 3.4.1.

3.5 Room temperature mea.«urement. Room temperature wherever specified shall be the temperature determined by using the test room thermocouple described In**~tlon** 2.5.

3.6 ;\fcan tank temp<:n1tun**m~rement.** Mean tnnk tempernture. the**avera~** tem- perature of the water in a 'il&"ater beater tank. whettwr specliled shall be the mean of the temperatures determined by usinf: the six
water heater tanlt tllermocouples described in seetlon 2.5.

4. Calculation ofdmred ;esults from test**measur~rnts.** 4.1 Rttet'l'1Y efficirnrp.

ffDERAl REGISTER, VOL 42, NO. 192-TUESDA"i", OCTO!IE!I. 4, 19774.1.1 Recoi·ery eff!cfency for ga.s and ofl irater heaters. For a gu or oU water heeter, calculate the recoveryefilclency, Er,**exp~** as n dimensionless quantity and defined M!

\\ht•rt• p _kXVXt>T,

··- Q,Xll '

J:..::.S\.:!.-l ntu iwr gallon ;)1'""., the nominal s1K'cific hrat

ofv."Ster. I"=tank capacity, d•trnninrd in a<rordance with

s«"tion 3.1, expn'SS<'d In gallons. .l "f":=dilTorenC'tl botw

.. n theInitial and final mi\!Ul tank tomprrntures. d•t•nnined in a<cordimce with &'<'lion 3.3.1.**e.'tpr~** in °1-". Q.**~total** fuel flow in ther..owry !Ml, d•termlned In !leCOrdance ";th section 3.3.1, expressed in appropriatr units. I l=lugbrrbeatingvaluofor thrnppro1>rlntefuel typo, If

••

### u•. or**JI~** as drtemlint'd in accordance with**~t'Clion** 2.-t. E.".tpressed in appropriate units.

4.1.2 Recovery efficiency for electric water heaters with. other th.an immersed heating elements. For an electric water heater with other**th~** immersed heating elements. calculate the recovery efilc!ency, E,, expressed

as a dinienslonless quantity and defined as:
kXVXAT1 

### E, Z,X3,412 Btu/kWh'

where k, V. and AT1 a.re as d•fint'd In section 4.1.1. Z.=total el<"Ctrlcal energy Dow tothebootingelemonL< in the recovery t<>st. dctrrmlnt'd In nccordance with section 3.3.1, expr"5Sed in kilmvntt-hours.

4.1.3 Recovery efficiency for electric water heaters with immersed heating elements. For

an electric water heater with immersedheatingelements, calculatetherecoveryefilclency, Er, expressed as a dimensionless quantity and defined as:

, SXkXVXAT, J:,=l- PX3,412 Btu/kWh'

wh··re k and i · are as defined in Sl'Clion 4.1.1

S=standby loss, as calculalt'd in section 4.4.2. AT,=-15° F., thenominal averagedl!Tcrcncebetween the mMD tank tempernture and the ambient lillr tempernture during recovery. P=water hooter input power, determined In scc-0rd-
ance with St""Ction 3.2.2, (":tprrsse-d in kilowatts.

4.2 Standby loss.

4.2.1 Standby loss for gas and oil water heaters. For a gas or oll water heater, calculate the standby loss, expressed in hour-' and defined as:

wh.-ro k. V, and ITare as defmrd In s.,.,tion 4.1.1 Ji:. is ascalculatffl in section 4.1.l

Q,=I-Ota! fuel flow inthestandbylosstest,determined in acoordance with section 3.4.1, expressed In approprlat.,units. AT,=ditfrrence betw

.. n the average value or themoon tank temperature and the average value or the :m1blent air temperature during the standby Ires t<>st, drlennincd in n<cordance with section :l.4.l,expr.,.__""""1 in °F. AT1=ditTerence betwe<'tl the Initial and final mean tank temperatures. determined in acrord!M1C$ with 5""Uon 3.4.1, expressed In °F. I=duration or the standby loss test, determined

in S<"rord:incc Vlitb section 3.4.l, expressed ha bt>tJ('S.. 

### RULES AND REGULATIONS

4.2.2 Standby k>si for electrk: iooter heater/I. For an electric water bem.t.er, calculate the standby loe8, B,**exp~**

### mhour

_. lllld defined as:**~-~·_X3,412** Btu/kWh

"

- kXVX.lTiXl !!i.T,**~T~XtXE/•** whore k and I'area.• dt•linrd in sretion 4.1.t.

Z.=total**~IP<"triral** em•rgy .:!ovr tothebt"-ating: E-lemt-nts: in**th~** standby loss tl'Sl, det<'rmlncd in aerordan<e with Sl'etion 3.4.1 for eloctric watrr heaters Mth oth1·r thn.n immerSt>d heuting t'lements, or section :1.-1.:! for ele.clric watt>r bP-atl"TS with immersed hrn.tini;t cl.-mt:>nts, t"Xpr,

...ssed in kilowatl·hours.. .3.1'1=dilf

..·rt"Hl"e lw-twe"n the avt:"rage volue oftho mPan tank**temperstnr~** and the 11vrmge value or the amhirnt air**tompt•r;~tnre** during tltP stn.ndhy Joss l••·a, drterminl'<l in nc·cordnnr"" with SP-<·tion 3.4.1 for C"lrctric watt>r**hf'at~rs**withothrrthan imnwrsrtl ht"a.ting elemeu1s. orsection 3.4.2for rlectric \\'aft>f' h•"a.tl"rs with imtth·rs<-d lw1uing**e1Nnt~uts,** £>:<·

A

### 7',=Ji~f~~1~c~\!~~-~~~!**;::~\ ,r:iiiBl**  and finnl nwan tnnk tt>JUJK"raturrs. dt"Lf'rmim·d in H.t•t·on:.Jnnee**withs~«·­** tion -3A.1 for elr-ctri<.· w11tr.r hr-aters v.ith othf'r thnn tuun(\r:'ed h<'ntini;? rh'-ments. or section 3.4.2: for <'lrt'tric Wi\t<'"r h£"ntrrs with imnwrsed bl!ating c?e·**nn~nts. axpn·s..~**  in kilowntt-honrs. l=dnration of th• standby lo.s t•st, drlrrminrd fn

nccordance with srction 3.4.1 for rll'etric watrr hoat•rs with othrr than lmtnrr""d heating elo- ments. or section 3.4.2 for E'lectric water heaters with innnersed htnling elements, expressed 'in hours. 

### J"•=J·:. as cnlrulnlrd in Sl'ction 4.1.2 for r!N'lric watrr hN>tors with other thnn imm•'<>•cd hc•ating ole- mrnls, or 0.98 for t•l

..tric wnt..r hooters wllh Im· nwrs-l'd heating cli•ments.

4.3 Daily water heating energy consumption. Calculate the daily water beating energy consumption, C

.... the energy required to heat the nominal amount of hot water used daily,**expres~ed** in Btu p!.'r day and defined as:**l:XUX~T.,** 

### E.

wherr 1: is as drfinf'Cl in**~ction** 4.1.1. E,. is as calculated in :>eetion 4.1.1 for**~ns** ant! oil water heaters, section4.1.2 for e!('C'tric**wst~r** hr.aters withothf'r than immersed h•ating elrmcnts, or srction 4.1.3 for electric water be:i.tcrs with immersed heating element,.
AT.=90" F., the nominal difforeneehct"l'l"Mn the water heater inlet and outlet water tPmperaturf".s. V=&-1.3 gallons per day. tho norninsl daily hot water usngo.
4.4 Arerage hourly hot water storage en- ergy conS1Lmption. Calculate the average hourly bot water storage energy consumption, 

# c.,. the average energy req\llred per hour t.o mal.ntain stored water temperature, expressed ln Btu per hour a.nd defined as:

c••**=SXkXYX~T., wh~re**  k and V are as def med in H"Ction ·I.LI. sis as calculated in soction 4.:?.1 for itas nnd oil**wat~r** heatent, or section 4.2.2 for electric "l'l"Bt-' hN1tN>'.**~1J9 ATa-=~Y.t**  tlK' ns,m[nal ilif!...r""urP lLMv.t"fll tlw nl6'9n tank t1tm1N!"fa.tur(" awJ tlw J1luhwut au tt"Wl"'"'!ature.

4.5 Average dally energy comumption. 4.5.1. Average tZ.atzy auzUiDr11 eZectrtc energy consumption /Of' ga.s and oil water heaters. Par a gu or oil W11.t.er beatef', calcu- !At& the average cb.l.ly awtilary electrical energy consumption, 

## c-. expressed ldlowatt-hours per day and defined a.s:

( • _,Cv1.,

. ,

# (·>• hottri-**('~•)**

•u•-;:;- l'r/-.. /' -r**I'•"~ -~** **d:a~·** - .f'. •

WbHP C,.., i:i**a.~** ,......i!t·nl:ttl"f'J in Sl"'f'f!on 4

... 1. l'=poWttinput totht"**burn~**. .i

...i.-nnhwd in**~·c.c:nda1H."""** with SN!tion**3.2..I~** t"Xpr.-:-.'(·'1 iu Htu JJ:d"f hour

.. p,=p-OWPr inputtuan''lau:uliary**..-l~rical** s.y614."'lll during pt'"riods of ma.Jn hurrarr or

..-mtllm. d<"termined iu n.ceordancP with St'<:'tim1 :t.:t.1. t-XfJt't':'i..""'od in kilowatt.."'. p,=powerinputt-0anyamilbr)'rl.-.:·trieal system during perio<ls when the malu hurtwr ls not In 01...,.,.Uou. dt-lt"rtnined tu**B!'t"ordao~:t·** vdtb $l'CUon 3.:!

..1. e111rr:.setJ in kilowatts..

4.5.2 Average dally gas or oil e:-.ergy consumption for l}ll3 and oil 1.00tet· h.e:ate-ra. For

:i. b'IS or oil water heater, calculate the aver- age dally gas or oil energy consumption, Cr.

as appropriate, expressed In Btu per day and defined as:

C"''isa.o; ('1\lcnlatPd in 5'.'CliO!l -1.:l.
c•• isas calcula.tOO in Sf'<:'tion 4.4. Pisasdefined ins«"tion 4.5.1.
J,=daily- <'n<>rgy- c....Wt for a h.-4t tr.ii• iiL<tall..-d in th., outlet waterconnf"Ction of a \\"°!:ltt"rht""41.er=I.:n1 Uua Jl"fday- for watrrb..,.t..,.,. that havesucha bE'at trap
a.< an integral part of th<' wat..r bt':\t"1", or %rro fur wat••r**lwat~rs** thatdonot. J ,=tlaily rnerg}"**~rrdlt** for a hr:il trap IJL,tall<'d in thP inlet \\11.t.er connt"C'tion or a wa.tt"f" h'E"31tt=9S3 Bui prrday for watrrhrot•rsthat hai.-E>SU<'h a heattrn1• a..' an intf1?rn). part or tht"' W3.ll"r**b~..itrr.** or zero for wutt-r heatt'rs that do not.

4.5.3 At·erage daily energy consumption for gas and oil water heaters.For a gu or oil water heater, calculate the average dally en- ergy consumption, 

### c,,. expressed In Btu per day and defined a.s:
Cr-·

## c,+c

....**'<~.-112** Rtu-'k\\'h,**\\'hf"n~** C1isas C!l.kULltf'd in**~"C'tion 4_!,.,.~.**  Can is nsc:ilculatt-d in**~~tion** -1• .5.l.

4.5.4 At•erage daily energy consumption for electric water heaters. For an electric water heater, calculate the average dll.Uy energy consumption. 

### c,, expresaed 1n kilowatt-hours per day and defined &S:



## c. 3,412

# B~u/k\\"hx[c

..

# ~+r••

## x(24

# h~~;s- f>X3,-tl;;;tu/kWh)-J

# ~-J.] c•• 1s ascalculatrd in srction4.3.

•- is as calculatedIn section 4.4. J,Md J,are as defined In section**4.5.~.** P=lnput power, determined In acroroarice with

_.. tion 3.2.l for electric "'1lter heettts withotb«**~** immersed hMtlngelemenl3orsection3.2.2forel<lclrie water hMten with lmmmed b(laling**elem~ts,** eJC- pr-1In lcllowatts. • {FRDoc.77-29000 Filed 10-3-77;8:45am}