[3128-01] 

PART 43O-ENERGY CONSERVATION 

PROGRAM FOR APPLIANCES 

Test Procedures for Furnaces and 

Vented Home Heating Equipment 

AGENCY: Department of Energy. 

ACTION: Final rule. 

SUMMARY: This rule prescribes final 

test procedures for furnaces and 

vented home heating equipment. Appliance test procedures are one element of the appliance energy efficiency program required by the Energy 

Policy and Conservation Act. The 

effect of this action is to establish 

standard methods of testing when 

testing is required by the Act or by 

regulations implementing other parts 

of the program. 

- EFFECTIVE DATE: June 15, 1978. 

FOR FURTHER INFORMATION 

CONTACT: 

James A. Smith (Office of Conservation), Room 307, Old Post Office 

Building, 12th and Pennsylvania 

Avenue NW., Washington, D.C. 

20461,202-566-4635. 

Jim Merna (Media Relations), Room 

3104, Federal Building, 12th and _ Pennsylvania Avenue NW., Washington, D.C. 20461, 292-566-9833. 

Laurence J. Hyman (Office of General Counsel>, Room 7150, Federal 

Building, 12th and Pennsylvania 

Avenue NW., Washington, D.C. 

20461,202-566-9750. 

SUPPLEMENTARY INFORMATION: 

A. BACKGROUND 

On October 1, 1977, pursuant to the 

Department of Energy Organization 

Act <DOE Act) (Pub. L. 95-91>, the Department of Energy <DOE) assumed - the authority of the Federal Energy 

Administration· (FEA) under the 

Energy Policy and Conservation Act 

(Act) (Pub. L. 94-163), with regard to 

the energy conservation program for consumer products. DOE hereby 

amends Part 430, Chapter n of Title 

10, Code of Federal Regulations, in 

order to prescribe test procedures for 

furnaces and vented home heating 

equipment pursuant to section 323 (42 

U.s.C. 6293) of the Act. These test 

procedures were proposed by notice 

issued August.ll, 1977 (42 FR 40826), 

for furnaces 3Jld August 31, 1977 (42 

FR 43930), for vented home heating 

equipment. Public hearings on the 

proposed test procedures were held on October 4, 1977, for furnaces and on November 2, 1977, for vented home 

heating equipment. 

By notice issued May 24, 1977 (42 

FR 27896), DOE established Subparts 

A and B of Part 430, Chapter n of 

RULES AND REGULAnONS 

Title 10, Code of Federal Regulations. 

Certain definitIons and general provisIons applicable to the energy conser- vation' program for appliances have 

been promulgated in subpart A. Final 

test procedures for room air conditioners, dishwashers, electrIc refrigerators 

and electrIc refrigerator-freezers, 

freezers, televisIon sets, clothes diyers; 

water heatt!rs, clothes washers, dehumldlflers, humldlflers, and central air 

conditioners have been prescribed in 

subpart B. Test procedures for ranges 

and ovens and unvented home heating 

equipment have been proposed for inclusIon in subpart B. DOE has also es· 

tablished a subpart C for appliance 

energy efficIency improvement targets. An outline of the provisIons of 

part 430 which have so far been established, including the provisIons in this 

rulemaking, is as follows: 

SUBPART A-GENERAL PROVISIONS 

Sec. 

430.1 Purpose and srope. 

430.2 Definitions. 

SUBPART B-TEsT Pnoa:lltJJu:s 

430.21 Purpose and scope. 

430.22 Test procedures lor measures of 

energy consumption. 

(a) Refrigerators and refrigerator-freezers. 

(b) Freezers. 

(e) Dishwashers. 

(d) Clothes dryers. 

(e) Water heaters. 

(D Room air conditioners. 

(h) Television sets. 

(j) Clothes washers. 

(It) HwnIdlllers. 

(l) DehwnIdlllers. 

(m) Central air conditioners. 

(n) Furnaces. 

• 

(0) Vented home heating equipment. 

430.23 Units to be tested (reserved). 

430.24 Representations regarding measures of energy consumption. 

(a) Refrigerators and refrigerator-freezers. 

(b) Freezers. 

(e) Dishwashers. 

(d) Clothes dryers. 

(e) Water heaters. 

(f) Room air conditioners. 

• 

(h) Television sets. 

(j) Clothes washers. 

(k) HwnIdlllers. 

(l) DehwnIdlliers. 

(m) Central air conditioners. 

(n) Furnaces. 

(0) Vented home heating equipment. . APPENDICES TO SUBPART B 

Appendix Al-UnIlorm Test Method for 

Measuring the Energy Consumption of 

Electric Refrigerators and Electric RelrIlterator-freezers. 

20147 

• • 

Appendix B-UnIlorm Test Method lor 

Measuring the Energy Consumption of 

Freezers 

Appendix C-Unlform Test Method - for 

Mea.surins the Energy Consumption of 

D/shwa.shers 

Appendix D-Unlform Test Method for 

Measurin&' the Energy Consumption of 

Clothes Dryers 

Appendix E-Unlform Test Method lor 

Measurinlt the Energy Consumption of 

Water Heaters 

Appendix F-Unlform Test Method for 

Measuring the Energy Consumption of 

Room AIr Conditioners 

Appendix H-Unlform Test Method for 

Measuring the Energy Consumption of 

Tele\1s!on Sets 

Appendix J-Unlform Test Method for 

Measuring the Energy Consumption of 

Clothes Wa.shers 

Appendix Kl-Unlform Test Method for 

Measurlng the Energy Consumption of 

Central System HwnIdlllers 

Appendix K2-Unlform Test Method for 

Measuring the Energy Consumption of 

Room HumIdlliers _ Appendix L-Unlform Test Method for 

Measuring the Energy Consumption of 

DehwnIdlllers 

Appendix M-UnIlorm Test Method lor 

Measurinlt the Energy Consumption of 

Central AIr Conditioners 

Appendix N-Unlform Test Method for 

Measuring the Energy Consumption of 

FurnAces 

Appendix O-UnIlorm Test Method for 

Measuring the Energy Consumption of 

Vented Home Heating Equipment 

Sec. 

SumoART C-ElrDGY EPnCIEl'l'CY 

lwPKOVEKENT TAllCJ:rS 

430.31 P\1rpo5e and scope_ 

430.32 Energy efficiency fmprovement targets 

Ca) Refrfgerators and refrfgerator-lreez- ers. 

(b) Freezers. 

(e) Dishwashers. 

(d) Clothes dryers. 

(e) [Reserved]. 

CD Tele .. 1s!onsets. 

(g) [Reserved]. 

(h) Television sets. 

(J) [Reserved]. 

(j) [Reserved]. 

(11:) HwnIdlllers." 

(J) DehumIdlllers. 

(m) Central air conditioners. 

B. DISCUSSION OF COMMENTS 

Comments were rece1ved from indJlStry, trade associations and members of 

the public. The major issues raised by 

the comments are dIscussed below. 

1. BURDEN OF n:srIl'iG 

Several commentexs criticized var- ious aspects of the proposed test pro- cedures as imposing signIficant resting 

burdens upon the industry. 

Several commentexs stated that. 

under their understanding of proposed 

sampling provisions 430.23 Cn) and (0), 

FEDERAL REGISTER. VOL. 43, NO. 91-WEDNESDAY, MAY 10, 1971 
20148 

the number of units to be tested wouid 

be large, and consequently burdensome. The commenters provided examples of the large number of units they believed would be required to be 

tested. 

, While it is not clear how these numbers were derived, they appear to 

result from misunderstanding the -ap- plication of the proposed sampling plan. DOE verified the, appropriateness of using the sampling provisions for furnaces and vented heaters by using typical furnace data. The correct 

application of the sampling provisions ' 

resulted in sample sizes inuch more 

reasonable than those cited by the 

commenters. " 

Also cited by the commenters as contributing to the burden of testing was 

the large number of basic models existing in the furnace and vented 

heater industry which wotild have to 

be tested. In an attempt to reduce the 

number of basic models to be tested, 

commenters suggested DOE adopt a. 

definition of basic model in which 

models would be grouped by common 

design characteristics. All units within 

such a basic model grouping would 

have energy efficiency characteristics 

either nearly identical to, or capable of correlation with, each -other. DOE 

does not have sufficient information 

to determine the Validity of such an 

approacn. Therefore, DOE has determined that the definition 'of basic 

model in the proposed test procedures will remain the same in the final rules 

described today. 

Many commenters suggested other 

alternative sa.nipling plans they believed were lesS burdensome. DOE has 

weighed these alternative sampling plans against the need for accuracy in 

the determination of any energy measure and, after an analysis of the available statistical and- economic information, DOE has determined that the 

proposed sampling plan results in reasonable accuracy without producing 

an unreasonable testing burden. 

Therefore, DOE has not changed the 

proposed sampling provision in the 

final rule issued today. _. In addition to' the large sample sizes 

discussed above, several of those commenting cited the cost and time of 

conducting tests as contributing substantially to the burden of testing. One of those commenting' noted the· 

cost of energy to conduct the test, due 

to the long test time. would itself 

become a significat factor contributing 

to high testing cost. 

These comments have been consid-' 

ered, and DOE has agreed to modify slightly the test procedures for the 

final rule •. The modifications simplifY the test procedures and result in reducing the testing time without reducing the accuracy. of the test results. 

DOE believes these modifications, discussed separately in item 5, signifiRULES AND REGULATIONS 

cantly reduce the cost of implement- , log the tests. 

2. SAMPLING REQUIREMENTS 

Several commenters addressed themselves to aspects of the sampling provi- :sions contained in the -proposed test 

pr.ocedures. 

. The test procedures prescribed under section 323 of the Act are intended to be used throughout the consumer products program, such as for 

labeling under 'section 324, for monitoring the progress of manufacturers 

towards meeting the energy efficiency improvement .targets under section 

325. and for enforcement testing under section 326. . These aspects of the appliance program have not, however. been imple- lnented. 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 units), may differ. DOE, the National Bureau of 

Standards (NBS) and the Federal 

Trade Commission (FTC) are continuing to evaluate the appropriate method or methods for sampling the 

units to be tested'in orderro comply with the statute and satisfy an of the 

different elements of the appliance 

program. 

While the "arious parts of the appliance program identified above are not 

in effect at this time, section 323(c) of 

the Act provides: 

Effective 90 days after a test procedure rule 

applicable to a covered product is prescribed 

under this section, no manufacturer, distributor, retailer or private labeler may make 

any representatlon- _ (1) in writing (including a representation on a labeI>, or . (2) in any broadcast advertisement, 1'espectlng the energy consumption of such 

product, unlel;s such product has been 

tested in accordance with such test proce- dure and such representation fairly discloses the results of such testing. 

In order to eliminate some of the 

difficulties associated with a general , sampling provision, section 430.23. 

which is concerned with the number 

of units to be tested. has been reserved 

in the final test ·procedures. Also, sampling requirements which apply only for purposes of advertising furnaces 

and vented heaters have be.en reorga- nized into §§ 430.24 (n) and (0) of the 

final test procedures. Sections 430.24 

(n) and (0) have been revised slightly from proposed §§ 430.23 (n) and (0).' 

Most notabLy. the units tested may 

now be representative of production units as well as actual production units. This change is intended to 

reduce any burden which might be 

caused by requiring post-production rating of basic ,lnodels 'in . every instance of testing pursuant to seCtion 

323(c) of·the Act. Until aJabeling rule 

-' 

has been implemented pursuant to 

section 324, manufacturers are not reo 

quired to test unless they choose to 

make representations regarding a 

measure of energy consumption identi· 

fied in or based upon §§ 430.22 (n) or 

(0). It should also be emphasized that 

the test procedures prescribed today apply only to the initial rating of a 

basic model where representations under §§ 430.24 (n) and (0) are con· 

cerned. 

Comments pertaining to several pro- posed test procedures criticized tho 

language of the proposed sampling provisions for 1ncorrectly relating tho 

sample mean and the true mean. DOE 

has corrected the language to relate 

the two means properly. Specifically. there is to be at least 95 percent confi· 

dence that the true mean of any measure of the basic model lies within ±5 

percent of the mean of such measures 

of the sample. 

3. TEST PROCEDURE SCOPE 

Several commenters stated that tho 

proposed test procedures did' not con· 

sider all ,relevant factors. Others 

stated- the test procedures did not ac· 

curately characterize the factors they did consider. 

The test procedures incorporate a 

heatloss method in which the sensible 

and latent heat losses through tho 

stack and flue are determined. Since 

these losses will depend on such fac· 

tors as load, cycling rate. chimney height, overslzlng, the type of draft 

control device, the infiltration charac· 

teristics of the residence and the 

weather profile, it is desirable to measure in the laboratory the quaIltles which characterize the performance of 

a furnace or boiler under standardized 

conditions to provide the best predic· tion of its performance under field 

conditions. The furnaces and vented 

heater test procedures prescribed today evaluate the unit plus any vent -system component, or other auxll1ary equipment essential to the perform· 

ance of the unit, that accompanies it 

when it is distributed in commerce. 

Under these procedures. testing is 

done only on new units and estimated 

annual operating costs refer only to 

the product's efficiency and performance under laboratory conditions. 

Annual maintenance costs, product reliabll1ty and other factors contributing 

to estimates of life cycle costs are not 

included. 

One of those commenting stated 

that the propos'ed test procedures for 

furnaces could not serve as a reliable 

guide to the energy efficiency of heating systems unless it considered the 

entire heating system. including the 

smoke pipe and chimney. This individual .stated' that a significant energy savings potential is available by im· 

provihg heat recovery in the smoke 

pipe and chimney. DOE agrees that 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 

J 
· there is some energy savings opportu- nity in this area but considers it unfeasible in the test procedure to credit accurately smoke pipe and chimney heat 

recovery to a furnace system considering the multitude of installation arrangements encountered in the field. 

This individual also suggested the 

proposed test procedures be expanded 

to allow flexi'bility in the determination of the draft. factors. He believed 

credit should be given in the test pro- cedures to devices that restrict stack 

'flow, thereby improving the efficiency of the heating system. DOE believes it 

is inappropriate at this time to give credit to a device that restricts stack 

flow when there is a possibility the 

furnace will be installed with a stack 

system that is sized such that the 

heating system will receive little or no 

benefit from the device. Furthermore, 

such a device is not within the scope of these procedures because it would 

not accompany the furnace when it is 

distnouted in commerce. 

Other commenters believed the pro- posed test procedures for furnaces 

were too limited because they did not 

include credits for night setback and 

zone control in estimating annual op- erating costs. DOE has determined 

these items should not be directly addressed irr the furnace and vented 

heater test procedures because data is 

unavailable at this time to determine 

typical consumer usage patterns. 

Finally, commenters stated the pro- posed definition of "furnace" was too 

broadly drafted. They stated that the 

proposed definition, by including in its 

scope units with hourly heat input 

rates of up to- 400,000 British thermal 

units (Btu's) for furnaces and boilers, 

did not accurately represent the residential furnace market and that a substantial number of units manufactured for commercial purposes were 

being incorrectly included in these test 

procedures. It was suggested that the 

limit be reduced to 1'75,000 Btu's per hour for gas furnaces and 225,000 

Btu's per hour for oil furnaces. 

As a result of these comments DOE 

has made an analysis of the residential 

furnace market and has determined 

that a reduction of the upper llm.it of 

input rate is warranted. DOE has also 

determined it appropriate to separate the upper limits for furnaces from 

those for boilers, but not for different 

types of fueL The upper limits pre- scribed in the final rule are 300,000 

Btu's per hour for boilers and 225,000 

Btu's per hour for furnaces. 

4. ESTIMATED A!t'"NUAL OPERATING COSTS 

Many of those~ commenting raised 

questions regarding accuracy and usefulness 'of the estimated annual oper- ating. costs to be derived from the test 

procedures. These questions concerned 

the effects of variations in heating 

season and energy costs across the 

RULES AND REGULATIONS 

country, variations due to the type of 

home construction, temperature controls (zone control, night setback and 

consumer preferences), and overestimation of the average number of heating load hours in & season from the 

use of 65· F as & balance point temperature for degree day computations. U~fulness of estimnted annual oper- ating costs to the consumer was !!!so 

criticized on the basis that equipment 

selection is usually made by bullders 

or heating system contractors and not 

by the consumer. 

DOE agrees these factors can have 

an effect on how closely annual operating costs derIved from these test pro- cedures approximate the costs of 

actual operation. The test procedures have been designed to evaluate the 

energy efficiency and typical cost of 

operation of a furnace or vented 

heater during a representative average 

use cycle rather than the actual oper- ating cost of a speclfic furnace In a 

specific application. The prlnu!.ry purpose of the estimated annual operat- ing costs derived from the test proce- dures is to provide & basis for compar- ing the efficiency levels of dlfferent 

heating systems when operating under 

a typical usage pattern. ThIs comparison should be useful both to consumers and to bullders or contractors selling homes to consumers conscIous of 

energy costs. 

In addition, several commenters suggested a change in the outdoor balance point temperature (currently 65' 

F) used in the test procedures. DOE is 

aware of the fact that the use of 65' F 

as a balance point temperature may 

not represent current house construction technIquea and the trend toward 

reducing residential infiltration rates. 

However, changing the balance point 

temperature would require an extensive and lengthy analysis and. untll 

such data is avallable, DOE has determined that the existing standard prac- tice of using 65° F as a base temperature will be used in these test proce- dures. 

5. STEADY STATE, Bl!:Ar-UP, AND COOLDOWN TESTING PROCEDURES (n.UE AND 

STACK REQUIREMENTS) 

A rommenter suggest.ed an Improved method of measuring the steady state 

efficiency 8J; well as the heat-up and 

cool-down temperature. It was SURested -that this be used for gas and on 

fueled furnaces, bollers, and vented 

heaters. 

This procedure claimed to Improve the DOE proposed procedures in the 

following respects: 

A single stack procedure, instead of & 5 

foot stack for steady state tests and 

a 2 foot stack for heat-up and cooldown tests as propo&ed by DOE, 

would be easIer to conduct because it 

would not require & shutdown and 

20149 

restart of the furnace for removal of 

the 5-foot stack and replacement 'Ytith the 2·foot stack. 

Standardizing the stack height at a 

constant 5 feet. instead of using a 

length whose top is 5 feet 6 inches 

above the highest point of the draft 

hood relief opening as orig:inally proposed. would make it possible to use 

the same stack on all appliances with the same draft hood outlet size. 

The 5-foot stack would be more repre- sentative of stack heights in the 

field than the 2-foot stack used in 

the proposed test procedures for 

heat-up and cool-down temperature 

measurements. - The use of a thermocouple grid on 

nine thermocouples rather than a 

single thermocouple would be more 

accurate for the heat-up and cooldown test. 

As a result of NBS' evaluation and 

recommendatIon, modifications based 

on part of the procedures suggested by the commenter have been incorporat- ed and are now a part of the final test 

procedures prescribed today_ The 

modified steady state portion of the 

suggested procedures has not been accepted because it would allow heat 

transfer from the fiue gases to the 

conditioned air in a manner that is not 

representative of normal operation 

(Le., with the draft hood open). The 

suggested 5-foot stack has been adopt- ed and the proposed 2-!oot stack has 

been elIminated. Also, the location of 

the thermocouples for measuring stack temperature in the steady state 

test has been made common with the 

lc::-ation for heat-up and cool-down 

tesbt. These changes have eliminated 

the ne.:d to replace the 5-foot stack 

with .. 2-foot flue pipe, and reduced 

the testing time from that required by the procedures as proposed. The suggested method of achieving 

Identical CO~ levels upstream of dilutIon.. through restricting the stack 

outlet during the heat-up and cooldown tests, has been incorporated into 

the test procedures for units with integral draft diverters. 

The use of nine parallel. connected 

thermocouples, Instead of one centralIy located thermocouple, ~ also been 

accepted. 

It was also suggested that an temperature· and CO2 measurements be 

made downstream of the draft control 

device. However, due to possible cooling and dilution of the flue gases, 

DOE considered it preferable to measure temperature and CO2 concentration upstream of dilution whenever 

poa;lble. In furnaces or vented heaters 

with & common fiue gas collection 

point. this presents no problem. Flue 

gases of such furnaces and vented 

heaters are now measured upstream of 

dilution and with a 5-foot stack pipe rather than the 2-foot flue pipe as proposed. Units with integral draft ellFEDERAL REGISTER. VOL 43, NO. 91-WEDNESDAY, MAY 10, 1911 
20150 

verters, however, typically have no_ 

common collection point. To measure 

flue gases upstream of dilution, one 

must therefore simulate a flue by sealing the draft diverter and' restricting the stack to reduce air flow. Thus, for 

furnaces and vented heaters with integral draft diverters, DOE has accepted the suggestions of these commenters 

and appropriately modified the test 

procedures. Also, instructions have 

been incorporated into section 2.6 of 

appendix N and 0 to insure that radiation shields be used on the thermocouples where radiation may be a 

problem. 

6. DESIGN HEATING REQUIREMENT FOR 

ELECTRIC FURNACES 

The proposed test procedures contained a 'constant, 0.5, as the typical ratio of steady state efficiency to 100 

times the average furnace sizing factor 

(assumed to be 1.7). The constant was 

criticJzed by commenters as oversimplifying the ratios for different catego- ries of furnaces and vented heaters. 

DOE agrees and has removed this constant, 0.5, from the test procedures. The calculation employing the constant has been replaced by a calculation ,of typiCal design heating requirement based upon a common table now 

incorporated into the final rule for 

electric, gas or oil fueled furnaces, 

boilers, or vented heaters for various 

output capacities. The output capacity 

is now a specified part of the test pro- cedures. 

" 7. TEST ROOM AIR TElItPERATURE 

Several comments' were received regarding the proposed limitation of 65" 

to 75' F on test room air temperature. These comments expressed concern 

that this limitation would' require equipment to air-condition the test lab 

at substantial cost. One of those commenting estimated that an initial investment of $60,000 would be required 

to air-condition a typical test facility. Several recommendations suggested wider. r~nges of test room air temperatures be allowed. NBS evaluated the 

impact that such a change would 

make on test data and determined 

that enlarging the allowable range Vlould have a negligible effect on test 

results if the data was mathematically corrected to a standard ambient air 

temperature. Therefore, a provision has been added to section 4 of Appen- dices N and 0 tha.t allows a test room 

air temperature range of 65' to 100' F, 

with a correction factor to be applied in the calculation procedure adjusting the test results to a standard ambient 

temperature of 70' F. 

8. BURNER AIR SHUTTER ADJUSTMENTS 

Comments were directed at the pro- posed method of adjusting the air 

shutter of gas burners at their maxiRULES AND REGULATIONS 

mum settblg prior to testing. The rec- posed to a space around the outside 

ommendation was that burners be ad- edge when the damper is closed). This 

justed'in accordance with the manu- comment predicted that stack (or flue) 

facturer's instructionS to avoid im- dampers would not be properly evaluproper operation such as poor combus- ated by the proposed calculation for 

tion, slow ignition, lifting flames, etc. Do in section 4.3. 

DOE has reviewed this suggestion and _ NBS has investigated the effects of 

agrees the manufacturer's recom- boundary layer flow by testing various 

mended adJustment is appropriate. dampers. The results of these tests 

The test procedure has been changed showed that the equation as proposed 

to incorporate this recommendation. was sufficient to measure accurately 

II. BOILER VTATER ~w ADJUSTr.tENTS 

Comments noted that the proposed sections 2.5.4 and 2.5.5 for adjusting the water flow rate were inconsistent. 

These Pfoposed sections referenced 

different ANSI standards for gas and 

oil fueled boilers, which used different 

outlet water· temperatures. The test 

procedures have been changed to 

make the outlet water temperature adjustment proposed for oil fueled 

equipment the adjustment for gas and 

electric equipment as well Comments 

also noted that' test conditions were 

not specified for oil fueled steam boilers. A steam boiler adjustment setting for steam pressure has now been specified in section 2.5.4. 

10. HEATING CAPACITY RATING 

A suggestion was made that the test 

procedures include a definition of 

heating capacity as the product of the 

measured steady state efficiency and 

the input to the appliance. This sug-' gestion has been accepted and incorpo- rated in the test procedures. 

11. STEADY STATE CALCULATIONS FOR 

FLUE LOSS 

A comment stated that flue losses 

calculated by the DOE procedures do 

not agree closely with those used aIfd 

accepted as established industry prac- tices for natural gas and, in particular, the method:; employed by American 

Gas Association Laboratories (AGA 

Labs). NBS investigated these ·prac- tices and recommended several 

changes to the assigned values of stoichiometric alr to fuel ra.tio (AIF) in 

table 3, used to calculate flue losses, to 

represent'typical properties of natural 

gases being distributed in the field. 

DOE has adopted this change in. order 

to obtain closer agreement with existing methods. 

12. EFFEcTIvEm:sS OF STACK (OR FLUE) 

DAMPERS 

A comment was made that calculations used to predict savings associated 

with the use of stack (or flue) dampers did not appear to reflect adequately boundary layer flow effects. It was 

claimed that; the factor Do, which is 

derived from' the percentage of open 

area in the stack or flue, did not take 

into account the location and shape of 

that open area <i.e., an open area in 

the center oJ the damper plate as opstack (or flue) damper effectiveness. 

However, as a result of this investiga- tion, the equation in section 4.3 has' 

been changed from that proposed to 

correct a discontinuity of the curve at 

A D/As=0.59. As a result of this change, the discontinuity is no longer present. and calculated values of Do are now 

available for all ratios of ADI As. 

Another commenter stated that the 

proposed test procedures indicated 

that a furnace equipped With a stack 

(or flue) damper, which when closed 

has an effective area of 80 percent or 

less, will use more energy than a furnace or vented heater without a stack 

(or flue) damper. The commenter b~ 

lieved this was incorrect. DOE agrees and has eliminated the draft factor in 

the equations for determining effective flue temperatures if the factor exceeds unity. 

13. STACK (OR FLUE) DAMPER OPERATION 

DURING THE COOL-DOWN TEST 

In the proposed rule, to evaluate the 

unit's fuel utilization efficiency, direct 

vent systems equipped with a flue 

damper were to be tested with tho 

device in place and closed dUring the 

cool·down portion of the test, whlle 

nondirect vent units that utilize l\ 

stack damper were to have a caloUlation rather than a test. This procedure 

was criticized as inconsistent. 

This apparent inconsistency is explained by considering the importance of measuring flue gas temperatures. . On furnaces with a stack (or flue) 

damper it is more representative of 

normal operation if the stack (or flue) 

damper is in place and closed during the cool-dOwn test. Therefore, DOE 

has retained this method in the test 

procedures wherever possIble. However, this method is possible only on a 

direct vent unit with a flue damper or 

a unit with a stick damper and barometric draft regulator. Units equIpped with an integral draft diverter or a 

draft hood have these draft relief devices sealed during the cooled-down 

test to measure accurately flue cas 

temperature and C02 as discussed in 

item 5. However, this procedure of 

blocking the draft relief devices does 

not allow the heat trapped by the 

stack damper to spill into the room as 

it normally would in the home. Therefore, to account for this effect on 

these units the procedures contain an 

additional correction faotor to evaluate damper effectIveness. 

fEDERAL R~GISTEa, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 
14. EFFICIENCY DEGRADATION OF OIL 

FUELED FURNACES 

In one comment it was indicated 

that soot build-up occurs in normal op- eration of most oil burning furnaces in 

the field which, in turn; causes a reduction of the fuel utilization efficien-' - cy of those furnaces. It was requested 

that the test procedures incorporate a 

measurement of fuel utilization effIciency under conditions representative of the soot build-up during typIcal 

usage. 

- DOE has D!!en unable to determine a 

representative condition of soot buildup given the variations in maintenance 

to which any furnace or vented heater 

may be exposed. As a result, DOE has 

determined that the test procedures 

prescribed today should be used to test 

new units only. 

It was also suggested that the cost of 

annual maintenance, such as removing 

soot build-up, -be a component of the 

estimated annual operating cost. The 

term "estimated annual operating 

cost" is defined in the Act as "the aggregate retall cost of the energy which 

is likely to be consumed annually in 

representative use of a consumer prod-

'uct." Therefore, the annual cost of 

maintenance does not fall within the 

definition of "estimated annual operating costs," and is not included in the 

final rule prescribed today. 

15. STACK (OR FLUE) DAlI(pERS ON OUTDOOR FURNACES, BOILERS, OR VENTED 

HEATERS 

One comment stated the proposed 

test procedures would show greater 

energy savings for the use of a stack 

damper on outdoor furnaces. than on 

indoor furnaces, a result he believed 

inconsistent with known data. 

In practice, a stack damper on outdoor equipment does not result in an 

energy savings since all heat trapped 

by the damper is discharged through 

the draft relief openings to the outdoors. The test procedures for furnaces and vented heaters intended for 

installation outdoors or in unheated 

areas, such as attics or crawl spaces, 

specify a Do factor only for flue 

dampers. A flue damper is the only 

type of damper that saves energy on 

outdoor units since heat can be 

trapped in the heat exchanger on the 

furnace side of the draft relief device. 

This savings is correctly accounted for 

in the test procedures. 

16. BLOCKING THE SOURCE OF 

COMBUSTION AIR 

One commenter' stated that following the procedures for outdoor installation resulted in blocking off the air 

intake. To avoid the possibility, a cautionary statement has been added to 

section 2.2.3 stating: -"care should be 

taken not to block the air intake with 

insulation." 

RULES AND REGULATIONS 

17. ENERGY SAVZNGS DUE 70 ELECrRICIGNITION 

According to some commenters, -the 

proposed test procedures failed to reflect accurately the energy savings 

available by using electrlc-lgnltion devices. NBS investigated this clalm and 

determined that a. modification to the 

calculation procedure was necessary to 

produce more realistIc values. ThIs has 

been accompllshed by including a. correction factor in the calculation of 

CT•orr in section 4.2.23 for furnaces and 

section 4.1.23 for vented heaters. 

18. EFFICIENCIES AT REDUCXD FIRING 

RATES 

One commenter suggested DOE further evaluate the assumption that a 

furnace with a reduced firing rate will 

have the same efficiency at both reduced and full flr1ng rates. He suggested efficiencies are generally lower at 

reduced.firing rates. 

DOE has determined that conventional reduced firing rate furnaces 

have lower steady state efficiencIes at 

the reduced firing rate since the inlet 

air openings, sized for the full firing 

rate, provIde' large amounts of excess 

air. However, when considering seasonal efficIency. the effect of reduced 

steady state effIciency at the reduced 

firing rate is offset by reduced cyc11ng. 

Consequently. even though the test 

procedures do not directly account for 

the lower steady state efficiency at reduced firing rates, they do correctly 

predict the seasonal efficiency of the 

conventional reduced firing rate furnace. 

19. CONSTANT PART LOAD UTILIZATION 

EFFICIENCIES 

Commenters also suggested DOE 

further evaluate the assumption that 

part load utUization effIcIency is constant for all cllmatlc conditions in all 

parts of the country. NBS performed 

an evaluation of this assumption prIor 

to the Issuance of the proposed test 

procedures. The same furnace or 

vented heater will have different representative part loads in different 

parts of the country. However. these 

differences were not found to be of a. 

magnitude reQ.uIrlng expanded test 

procedures to determine. a regional 

annual utlllzation efficiency. The effI· 

clency, as now determined, uses a one 

temperature "bin" approach to calculate the representative part load for 

furnaces or vented heaters in each 

region of the United States during one 

heating season. A multltemperature 

"bin" approach would be needed to 

provide a more exact regionalized test 

procedure. NBS considered a six temperature "bin" method and found the 

additIonal incremental accuracy did 

not warrant the more lengthy calculation procedure. 

20151 . 20. SPECInED FUEL ClIARAC'naUSTICS 

At the public hearing, it was suggest- ed the 'tolerances for natural gas as 

specIfied for testing <ie., hIgher heat 

value equal to 1,025 Btu's ~ cubic. 

foot, ±5 percent) be deleted and that 

whatever pipeline gas Is distributed to 

be used for the test gas. The higher heating value of natural 

gas varies for many parts of the country depending on the source of the 

natural gas. Also, in winter many companies "peak shave;" that is, in periods 

of hIgh demand, the natural gas delivered to customers Is supplemented by 

mixing it with propane gas. Consequently. during periods of high 

demand (ie., cold weather) the heatIng value and specl.!lc gravity of the 

distributed gas can vary. 

The ±5 percent tolerance on higher heating Talue for all test gases is specifIed because the constants used for determinlng steady state flue loss. A/F 

(stoichIqmetric air to fuel ratio). and 

Lz.A (latent heat loss). are dependent 

on mainta.inlng the test gases within 

the speci!ied tolerances. In these test 

procedures it is necessary both to limit 

the variation of the speclflc heating 

value of the fuel and to measure the 

actual value with an accuracy of 1 percent. Thus, the test procedures prescrIbed today retain the tolerances for 

natural gas orIgi.nal.Iy speclfled. 

21. WAn:Rl'UlI:P ENE1lGY~ 

Section 3.1.6 required pump energy 

(PE) to be measured. Comments noted 

that due to the variety of pIping arrangements that can be attached to & 

boner in the field, the PE consump- tion can differ considerably from one 

Installation to another. It was recommended that a typical electric power 

raUng be used for the calcUlation instead of a laboratory measurement. 

NBS recommended a typIcal rating of 

0.13 kW whIch has now been incorpo- rated into section 3.1.2 of appendix N. 

22. OIL Bumn:R ADJUS'D[ENTS 

Section 2.4.2 speclfled that on 

burners be adjusted to give the best 

CO2 reading. Comment was receiyed 

that this was not a realIstic setting for 

boner burners. It was further noted 

that boners are sold in two basic ways: 

as bare boners to be equipped with 

any on burner avafIs.ble in the field (as 

decided by the customer or the installing contractor), or as a boner-burner 

unit Incorporating a. flame retention 

burner matched to the boner by the 

manufacturer. According to the comment, boners in both categories are 

rated by the manufacturer in terms of 

CO2 adjustment whIch Is 10 percent 

for the bare boner and 12 percent for 

the boner with the burner as part of 

the package. It was stated there are oil 

burners avalla.ble that can produce 13 

percent to 14 percent CO2 in the IaboFEDERAL ItEGISTER. VOL 43, NO. 91-WEDNESDAY, MAY 10, 197. 
20152' 

ratory. However, such values ca.ruiot 

be obtained in practice since a margin 

must be ,allowed for safety to cover 

daily variations in available draft, air 

density, etc. 

To better represent the field in: 

stalled condition, the statement directing the tester to adjust the unit to the 

"best" CO. has been changed to direct 

him to adjust the unit to the CO. 

reading recommended by the manufacturer. Additionally, the specifica.- tion for smoke has been changed from 

a No.2 to a No.1 smoke adjustment to 

better represent field conditions. 

The statement, "adjust to the manufacturers CO. recommendation" is not 

intended to limit the cO. to 10 percent 

or 12 percent. If a higher CO. level is 

possible while achieving the prescribed smoke setting, then that adjustment is 

permissible if the manufacturer no!: 

mally recommends it for field adjustment. In any case, the No.1 smoke setting governs burner adjustment irrespective of the manufacturer's CO. 

recommendations. ' 

23. BURNER OPERATING HOURS 

Comments were made that the 

number of burner operating hours pre-' dieted by the proposed test procedures 

was greater than the actual number of 

burner operating hours of furnaces in 

the field. , I The calculation for burner operating hours is based on an average ,or typical design heating requirement and the 

average or typical heating load hours. 

The design heating requirement is determined in the test procedures using 

a value of output capacity (Qout) for a 

particular furnace or vented heater. 

The heating load hours are determined using the standard 65° F base. 

These determinations do not fully account for internal loads and tIie dy- namic nature of the heating flow of 

the structure. As a consequence, the 

design heating requirements and heat 

load hours determined by these calculations tend to be larger than the 

actual heating loads required to be 

met by the heating appliances and, 

therefore, the burner operating hours 

and the annual energy consumption 

are over-estimated. NBS has reviewed 

much of the, technical information 

available on this subject; in particular, the information published by the 

American Society of Heating, Refrig- eration, and Air Conditioriing Engineers (ASHRAE). DOE has adopted 

the NBS recommendation of including 

a constant adjustment factor in the 

furnace, vented heaters and unvented 

heater test procedures. This adjustment factor will ,improve the '1greement between the average calculated 

operating cost and the actual cost incurred by the consumer. 

After reviewing data, NBS recommended, and DOE accepted' the value 

of 0.77 as the adjustment factor. This 

..,. RULES AND REGULATIONS 

is applied in the deternlination of 

burner operating hours for fossil 

fueled units and in the determination 

of annual energy consumption for 

electric unit/I. . Also, some commenters criticized the 

assumed oversizing factor of 70 percent used in the calculation of burner 

operating hours. In the field, many furnaces and vented heaters are con-' 

siderably more than 70 percent oversized. Consequently, they operate fewer hours, at a higher firing rate, 

than would less oversized furnaces or 

vented heaters. However, the oversizing practices of the past are being moderated today because of an increasing 

awareness that oversized equipment is 

less efficient. Therefore, DOE believes 

the 70 percent oversizing factor is currently an appropriate factor to use in 

these calculation procedures. . These procedures provide a basis for 

comparing furnaces and vented heaters based 011 the design heat loss of 

the house. Consequently, a'larger capacity furnace or, vented heater will 

show approJrimately the same cost of 

operation as a smaller furnace or 

vented heater' when each is compared for cost of operation at the same 

design heat loss, providing both have 

t!te same seasonal efficiency.. . 

24. JACKET LOSS MEASUREMENT 

PROCEDtmE 

One comment stated that the proce- dures used in the referenced ANSI 

Standard fOJ: jacket loss measurement . (PoNSI Z21.47) would not properly evaluate the jacket loss of an underIrred boiler. ACcording'to the commenter, the most significant jacket loss of sucll boilers is through the 

bottom. As an alternate method of determining this jacket loss, he suggested conducting a full thermal efficiency 

test as specified in other ANSI standards for boilers. These standards measure and add the output energy, in the 

heated water at steady state oper- ation, to the flue loss, expressed as a 

percent of the total input, and 'SUbtract this total from 100 percent. The standards suggested by the commenter themselves do not measure 

jacket loss through the bottom. although they do provide for determining the total boiler jacket losses. 

These standards deduce jacket losses 

from a measured heat output. , A direct measure of the heat output of a furnace or vented heater would be 

considerably more difficult, and as yet has not been developed. Since the pro- posed procedure accurately measures 

fuel utilization efficiency for both furnaces and boilers, DOE has determined to retain the procedure origi- nally proposed for measuring jacket losses. 

25. SIMPLIFICATION OF DATA COLLECTION 

Alm COMPUTATION ' 

Several eommenters expressed concern over the lengthy and difficult cal-

, 

culations and the many measurements 

contained in the proposed test proce· dures. The calcuiations as proposed 

were necessary to allow a fair compari· 

son of diverse centro.! heating equip· 

ment types end produca reasonably realistic numerlcal results. Exfutin(! in· 

dustry test procedures measura steady 

state efficiencies. but do not account 

for eny part 103d or seasonal perform· 

ance effects. The additional datil. reo 

quirements of the .DOE test proce· dures are due to the treatment of the 

part load and seasonal effects neces· 

sary to estimate annual operating 

costs and to give credit fOr equipment features that improve efficiency under 

part load conditioll3. ' 

26. MAlWJU, CALCULATIONS 

The proposed test procedures were 

designed to allow manual computation methods and included several tables 

and families of graphs. Several memo 

bers of industry attempted to carry 

out the indicated calculations, using specific equipment examples and 

manual methods. Unsatisfactory results were reported in terms of repea- tability, precision and manpower costs. 

Commenters noted that computers are 

generally ava.ilable and that their use 

as the normal computation method 

would be far more practical. DOE reoognizes the Validity of these comments 

by induatry and will nsnist in the 

transformation from manual to computer procedure3. A compuwr pr()oo 

gram for the calculatioIl3, based on 

the worr.shecl contaL'led in the test 

procedures, is available to all interested parties in the DOE Public Reading Room, Freedom of Information Office, 

Room 2107, 12th and Pennsylvania Avenue NW., Washington, D.C. 20461 

27. UTILIZATION EFFICIENCY BASED OU 

PRIMARY ENERGY SOUROE ' 

One commenter believed it would be 

deceptive to the consumer to consider 

energy efficiency only at the point of 

use. The commenter stated that 

energy efficiency should bo doter· 

mined from the primarY energy 

source, i.e., the power plant. Section 323(a)(4)(A) of the Aet requires DOE to prescribe test proce- dures for different consumer products for the determination of an estimated 

annual operating cost for each product and at least one other measure of 

energy consumption which DOE determines is likely to assist consumers in 

making purchasing decisions. DOE has 

determined the measures of energy consumption presoribed today will be 

useful to consumers and nre likely to 

assist them in making purohasing decisions. DOE does not consider it neces· 

sary to prescribe any additional measures of en~rgy consumption at this . time. 

28. PROPANE ~ILOT UTILIZATION 

Comment was received from the 

liquid p'etroleum (LP) gas industry em· 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 
phasizing their concern with any action which would preclude the use 

of gas pilots on LP gas fueled heaters. 

These test procedures do not preclude the use of pilots on LP gas heaters. 

29. COMPARISON ,OF VENTED HEATERS AND 

FURNACES 

A commenter stated the test proce- dures should allow for a fair comparison of all types of heating equipment and therefore must be as consistent as 

possible among types.and still consider 

the different usage patterns and conditions of operation to which vented 

heaters and furnaces are exposed. The 

commimter suggested that a correction factor could be applied to the 

vented heater calculation to account 

for these differences. 

DOE has determined it appropriate 

to address vented heaters in the test 

procedures in the same way as furnaces, since the typical use of vented 

heaters is as a primary heat source in 

a home. Furthermore, DOE believes a 

correction factor applied to the vented 

heater test procedures in order to refleet typical differences between 

annual' cost of operation of vented 

heaters and furnaces could be mislead- . ing. Such a correction factor giving 

higher annual operating costs for furnaces might imply to a consumer that 

the seasonal efficiencies of furnaces 

are .generally lower than those of 

vented heaters. 

30. MISCELLANEOUS 

After careful consideration of all of 

the comments and further consultation with NBS and :FTC, DOE has 

made some editorial and minor technical changes in the proposed test procedures that were not discussed above 

and incorporated them in the final 

rule prescribed today. 

C. REGULATIONS PREsCRIBED 

1. TEST PROCEDURES 

The test procedures for furnaces and 

vented home heating equipment prescribed today are included in subpart 

B and are substantially the same as 

those proposed, with the exception of 

the changes discussed above. As with 

the proposed procedures, the methodology of the tests incorporate parts of 

the following standards: American National Standards' Institute (ANSI) 

Zll.182-1965 (R1971>, Z21.11.1-1974, 

Z21.13-1974, Z21.44-1973, Z21.47-1973, 

Z21.48-1976, Z21.49-1975, and Z91.1-

1972, Underwriters Laboratory (UL) 

729-1976, 730-1974, and 896-1973, Air 

Conditioning and Refrigeration Institute (ARI) 280-74, and The Hydronic 

Institute em) "Testing and Rating 

Standard for Cast Iron and Steel 

Heating Boilers - January 1977." 

These standards are used in the test 

procedures with additional methodology to determine energy consumption. 

RULES AND REGULATIONS 

For PUrPoses of DOE's program, the 

incorporated standards remain applicable as presently written, regardless of any subsequent amendment of the 

ANSI, UL, ARI, or ill standards, until 

further amendment by DOE. Copies of 

these standards are avallable for inspection at the DOE Public Reading 

Room. 

Under the requirements of sectlon 

32(c) of the Federal Energy Adm1nJ.s. 

tration Act of 1974 (15 U.s.C. 761 et 

seq:) as amended by section 9 of the 

Federal Energy Administration Authorization Act of 1977 (Pub. L. 95-70), 

the Administrator of FEA Is to consult 

with the Attorney General and the 

Chairman of the Federal Trade Commission concerning the impact on competition of any rules prescribed by FEA which utilize or incorporate any 

commercial standards. As noted earlier, the Administrator's functions have 

been assumed by the Secretary of 

Energy. 

Copies of the test procedures for furnaces and vented home heating equip. 

ment, which incorporate the abovementioned commercIal standards, have 

been transmitted t~ the Attorney General and to the Chairman of the Federal Trade Commission for their comments concerning the impact of such 

standards on competltIon, in accordance with sectlon 32(c). Neither official has any comments, nor do they 

recommend against the incorporation 

or use of these commercial standards 

in the final test procedures for furnaces and vented home heating equip. 

ment. 

2. GENERAL PROVISIONS 

Also prescribed today are deflnltlons 

of "BasIc· model" with respect to furnaces and vented home heating equip. 

ment, "Direct vent system," "Electric 

central furnace," "Forced air central 

furnace," "Furnace," "Gravity central 

furnace," "Low pressure steam or hot 

water boller," "Outdoor furnace or 

boller," "Vented home heating equip. 

ment," "Vented heater," ''Vented wall 

furnace," ''Vented floor furnace," and 

''Vented room heater." The deflnltlons 

for furnaces and bollers were previous- ly proposed in subpart A issued July 28, 1977; (42 PH 40826, August 11, 

1977). The deflnltIons for vented home 

heating equipment were previously proposed in subpart A issued August 22, 1977 (42 PH 43930 August 31, 

1977). Comments which were received 

regarding these definitIons and the 

issues which they raised have been discussed earlier in this notice. 

3. APPLICATION OF TEST PROCEDURES 

As discussed previously, the final 

test procedures prescribed today must 

be applied before representations regarding a measure of energy consumptIon can be made. Because the purposes and needs of the dlfferent ele20153 

ments of the appliance program (e.g •• 

labeling, targets) vary, application of 

the standard test methodology pre- scrIbed today may differ in some re- ' 

spects for each program element_ It is 

expected that instructions on how to 

apply the standard test methodology 

to these other elements of the appliance program will be proposed for 

comment in the near future. 

The requirements of § 430.24 (0) and 

(0) 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 rep. 

resentations regarding a measure of 

energy consumption covered by a labeling rule must be the same as represented on the labeL 

D. UNIT COSTS OP ENERGY 

Under section 323(b)(2) of the Act, 

PEA is t~ provide manufacturers information as to the representative 

average unit costs of energy. This information was provided by· notice 

Issued July 11, 19'17 (42 PH 36549. July 15,1977). . E. PREEm>TION 

Today's rulemaklng prescribing final 

test procedures for furnaces and 

vented home heating equipment supersedes any State regulation to the 

extent required by sectIon 327 of the 

Act. Pursuant to section 327, all State 

regulations which provide for the disclosure of information with respect to 

any measure of energy consumption of 

furnaces or vented· home heating equipment, or which provide for any 

energy efficiency standard or similar 

requirement with respect to energy efficiency or energy use of furnaces or 

vented home heating equipment. must 

now employ test procedures identical 

to those specl!Ied in today's final rule_ 

CEneru Pollcy and Conservation Act. Pub. 

L. 9t-163, U amended by Pub. L. 94-385; 

Federal Energy AdmInIstration Act of 1974, 

Pub. L. 93-275, as amended by Pub. L. 94-

385; E.O. 11790, 39 FR 23185 Department of 

Energy OrpnIzation Act. Pub. L. 95-9L) 

In consideration of the foregoing, 

Part 430 of Chapter n of Title la, 

Code of Federal RegulatIon, is amended as set forth below, effective. 

Issued in Washington, D.C .• May 2. 

1978. 

WILLIA!ol P_ DAVIS, 

Deputy DirectoTof 

Administroticm. 

1. Section 430.2 is amended by adding subparagraphs (14) and (15) as 

part of the definition of "basic model" 

and by adding in appropriate alphabetical order the definitIons of "direct 

vent system," "electric boiler," "electric central furnace:' "forced air central furnace," "furnace," "gravity central furnace," ''low pressure steam or 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 
20154 

hot water boiler," "outdoor furnace or 

boiler," "vented home'heating equipment" or "vented heater," "vented 

floor furnace," "vented room heater," 

and "vented wall furnace," to read as 

follows: 

§ 430.2 Def'mitions. 

• • • • 

"Basic model" means all units of a 

given type of covered product manufactured by one manufacturer and-

(14) with respect to furnaces, having the same primary energy source and 

essentially identical functional, physi- cal and electrical characteristics. 

(15) with respect to vented home 

heating equipment, having the same 

primary energy source and essentially 

identical functional, physical and electrical characteristics. 

• • • • • 

"Direct vent system" means a 

system supplied by a manufacturer 

which provides outdoor air or air from 

an unheated space (such as an attic or 

crawl space) directly to 'a furnace or 

vented heater for combustion and for , -draft relief if the unit is equipped with 

a draft control device. ' 

"Electric boiler" means an electrically powered furnace designed to supply 

low pressure steam or hot water for 

space heating application. A low pressure steam boiler operates at or below 

15 pounds per square inch gauge (pslg) 

steam pressure; a hot water boiler operates at or below 160 psig water pressure and 250· F water temperature. 

"Electric central furnace" meaDs a 

furnace 'designed to supply heat 

through a system of ducts with air as 

the heating medium, in which heat is 

generated by one or more electric resistance heating elements and the 

heated air is cirCulated by means of a 

Ian or blower. 

i'Forced air central furnace" means 

,a gas or oil burning furnace designed 

to supply heat through a system of 

ducts with air as the heating medium. 

The heat generated by combustion of 

gas or oil is transferred to the air 

\ within a casing by conduction through 

heat exchange surfaces and is circulated through the duct system by means 

of a fan or blower. 

"Furnace" means a device designed 

to be the principal heating source for 

the living space of a residence having 

a heat input rate less than 300,000 

Btu's per hour for electric boilers and 

low pressure. steam or hot water boilers, or 225,000 Btu's per hour for 

forced air central furnaces, gravity 

central furnaces, and electric central 

furnaces. 

"Gravity central furnace" means a 

gas fueled furnace which depends pri- marjly on naturaiconvection for circulation of heated air and which is deRULElS 'AND REGULATIONS 

signed to lIe used in conjunction with 

a system of ducts. 

"Low pressure steam or hot water 

]loiler" means an electric, gas or oil 

burning furnace designed to supply 

low pressure steam or hot water for 

space heating application. A low pressure steam boiler operates at or below 

15 pounds psig steam pressure; a hot 

water boiler operates ,at or below 160 

psig water pressure and 250· F water 

temperatw"e. 

"Outdoor furnace or boiler", is a furnace or boiler normally intended for 

installation ou~f-doors or in an unheated space (such as an attic or a 

crawl space). 

"Vented home heating equipment" 

or "vented heater'" means a class of 

home heating equipment, not including furnaces, designed to furnish 

warmed air to the living space of a 

residence, directly from the device, 

without duct connections (except that 

boots not to exceed 10 inches beyond the casing may be permitted) and includes: vented wall furnace, vented 

floor furnace, and vented room heater. 

"Vented floor furnace" means a selfcontained vented heater suspended from the floor of the space being 

heated, taking air for combustion from 

outside this space. The vented floor 

furnace supplies heated air ciroulated 

by gravity or by a fan directly into the 

space to be heated through openings 

in the casing. • 

"Vented room heater" means a selfcontained, free standing, nonrecessed, 

'vented heater for furnishing warmed 

air to the space in which it is installed. 

The vented room heater supplies heated air circulated by gravity or by 

a fan dire~tly into the space to be 

heated through openings in the 

casing. 

"Vented wall furnace" means a selfcontained vented heater complete with grilles or the equivalent, designed 

for incorPora.tion in, or permanent attachment 1;0, a wall of a residence and 

furnishing heated air circulated by 

gravity or by a fan directly into the 

space to be heated through openings 

in the casing. 

2. Section 430.22 is amended by adding paragraphs (n) and (0), to read '~follows: 

§ 430.22 Test procedures for measures of 

energy consumption. . 

• • • • 

(n) Furnaces. (1) The estimated 

annual operating cost for furnaces is 

the sum of (i) the product of the average annual fuel energy consumption, 

in Btu's per year for gas or oil furnaces or in kilowatt-hours per year for 

electric furnaces, determined according to 4.8 or 4.10 of appendix N of this 

subpart, respectively, and the representative average unit cost in dollars 

, 

per Btu for gas" or oil, or dollars per kilowatt-hour for electric, as appropriate, as provided pursuant to section 

323(b)(2) of the Act, plus (li) the product of the average annual auxUlary electric energy consumption in kUowatt-hours per year, determined according to 4.9 of appendix N of this 

subpart, and the representative average unit cost in dollars per kilowatthour as provided pursuant to section 

323(b)(2) of the Act, the resulting sum 

then being rounded off to the nearest 

dollar per year. 0 

(2) The annual fuel utilization efficiency for furnaces, expressed in percent, is the ratio of annual output of 

useful energy delivered to the heated 

space to the annual fuel energy input 

to the furnace determined according 

to 4.2.33 of appendix N of this subpart for gas and oU furnaces and determined in accordance with 4.1 of nppondix N of this subpart for electric iurnaces. 

(3) The estimated regional annual 

operating cost for furnaces is the sum 

of (i) the product of the regional annual fuel energy consumption in 

Btu's per year for gas or oil furnaces 

or in kilowatt-hours per year for electric furnaces, determined according to 

4.12 and 4.14 of appendix N of this 

subpart. respectively, and the representative average unit cost in dollars 

per Btu for gas or oil. or dollars per 

kilowatt-hour for electric, as appropriate, as provided pursuant to section 

323(b)(2) of the Act, plus (li) the product of the regional auxUiary electrical 

energy consumption in kilowatt-hours 

per year, determined according to 4.13 

of appendix N of this subpart, and the 

.representative average unit cost in ·dollars per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act, 

the resulting sum then being rounded 

off to the nearest dollar per year. (4) Other useful measures of energy 

consumption for furnaces shnll be 

those measures of energy consumption 

which the Secretary of Energy determines are likely to assist consumers in 

making purchasing decisions and 

which are derived from the application of appendix N of this subpart. 

(0) vented home heating equipment. 

(1) The estimated annual operating 

cost. for vented home heating equip. 

ment is the sum of (i) the product of 

the average annual fuel energy consumption in Btu's per year, determined according to 4.7 of appendix 0 

of this subpart, and the representative 

average unit cost in dollars per Btu for 

gas or oil, as appropriate, as provided by the Administrator, plus (if) the 

product of the average annual auxiliary electric energy consumption in 

kilowatt-hours per year, determined 

according to 4.8 of appendix 0 of this 

subpart, and the representative average unit cost in dollars per kilowatthour as provided by the Adminlstra· 

FEDERAL REGISTER, VOI~ 43, NO. 91-WEDNESDAY, MAY 10, 1918 
tor, the resulting sum rounded off to 

the nearest dollar per year. (2) The annual fuel utilization efficiency for vented,home heating equipment, expressed in percent, is the ratio 

of annual output of useful energy de-' 

livered to the heated space to the 

annual fuel energy input to the vented 

heater determined according to 4.1.33 

of Appendix 0 of this subpart:-

(3) The estimated regional annual 

operating costs for vented home heating equipment computed for different 

typical design. heating requirements is 

the sum of (i) the product of the regional annual fuel energy consump- tion for the typical design. heating requirement being used, in Btu's per 

year for gas or oil vented heaters determined according to 4.10 of Appendix 0 of this subpart, and the representative average unit cost in dollars 

per Btu for gas or oil, as appropriate, 

as proviqed by the Administrator plus 

(li) the product of the regional annual 

auxiliary electrical energy consumption in kilowatt-hours per year determined according to 4.11., as appropriate, of Appendix 0 of this subpart, 

and the representative average unit 

cost in dollars per kilowatt-hour as 

provided-by the Administrator, the resulting sum then being rounded off to 

the nearest dollar per year. (4) Other useful measures of energy 

consumption for vented home heating 

equipment shall be those measures of 

energy consumption which the Administrator determines are likely to assist 

consumers in making purchasing decisions and which are derived from the 

application of Appendix 0 of this subpart. 

. 3. Section 430.24 is amended by adding paragraphs (n) and (0) to read 

as follows: 

§ 430.24 Representations regarding measures of energy consumption. 

• • • • • 

(n) Furnaces. (1) Except as provided in paragraph (n)(3) of this section, no 

manufacturer, distributor, retailer, or 

private labeler of furnaces may make 

any representation with respect to or 

based upon a measure" or measures of 

energy consumption described in 

§ 430.22(n) unless a sample of sufficient size of each basic model for 

which such representation is made has 

been tested in accordance with appli- cable provisions of this subpart such 

that for each such measure of energy 

consumption, there is 95 percent confidence that the true mean of such 

measures of the basic model lies 

within ±5 percent of the mean of such 

measures of the sample. (2) The sample selected for para- graph (n)(1) of this section is to be 

comprised of units which are production units, or are representative of proRULES AND REGULATIONS 

duction units, of the basic model being 

test.ed. 

(3) Whenever a rule applicable to 

furnaces is prescribed under Section 

324 of the Act, this paragraph (n) 

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 

to the measure of' energy consumption 

of the labeL . (0) Vented home heating equipment. 

(1) except as provided in paragraph 

(0)(3) of this section, no manufacturer, 

distributor, retailer, or prIvate Iabeler 

of vent.ed home heating equipment 

may make any representation with respect to or based upon a measure or 

measures of energy consumption described in Section 430.22(0) 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 consumption, there is 95 

percent confidence that the true mean 

of such measures of the basic model 

lies within ±5 percent of the mean of 

such measures of the sample. (2) The sample selected for para- graph (0)(1) of this section Is to be 

comprised of units which are production units, or are representative of production units, of the basIc model being 

tested. 

(3) Whenever a rule applicable to 

vented heaters Is prescribed under 

Section 324 of the Act, this paragraph 

(0) shall not apply to any label covered by such rule, and all representations of any measure of energy consumption covereq, by such rule shall be 

identical to the measure of energy 

consumption on the labeL 

(4) Subpart B of Part 430 Is amended 

to add Appendices N and 0, to read as 

follows: 

APPENDIX N-UNIFORK TEsr M!:mOD FOIt 

MEAsURING THE ENERGY COHSt1KPrlOH or FuRNACES 

1.0 Definitions. 

1.1 "Steady·state conditions" means equI· llbrium conditions as indicated by temperature variations of not more than 3' P (1.'1' 

C) In the stack gas temperature for unIts 

equipped with Integral. draft dIverters, or not more than 5' P (2.8' C) In !lue gas temperature for unIts equipped with draft 

hoods, barometric draft regulators. or d1rect 

vent systems, In three liUcces.s1ve temperature readIngs taken 15 minutes apart. 

1.2 "Steady·state conditions for low pres- sure steam and hot water boDers" means steady-state conditions as defined In 1.1 

above and variations of not more than t' P 

(2.2' C) In the outlet water temperature for 

hot water boUers In three liUccess1ve read· 

ings taken 15 minutes apart. 

1.3 "Flue gases" means all gases In the 

!lue during the duration or combustion In 

the combustion chamber, including reaction 

products, Inerts and any excess alr. 

1.4 "Excess air" means air whJch pa.sses 

through the combustion chamber and the rurn~ !lues In excess of that whJch Is 

20155 

theoretIcally required for complete combustIon. . 

1.5 "Flue" means It conduit between the 

!lue outlet of the rurnace and the Integral draft dIverter, draft hood. barometric draft 

regulator, vent termInal, or any other POint 

of draft relIef. 

1.6 ''Furnace outIet" means the opening 

provided In a furnace for the exhaust of the 

!lue gases from. the combustion chamber. 

1.'1 "Flue losses" means the sum of sensible and latent heat losses above room temperature of the !lue gases leaving the fur- nace. 

1.8 "Stack" means the portIon of the exhaust system downstream of the draft dIverter, draft hood or barometric draft regulator. 

1.9 "Stack pres" means the mIxture of 

the !lue p..ses and air that enters at the 

draft dIverter, draft hood. Integral draf~diverler, or barometric draft regulator. 

1.10 "Barometric draft regulator or barometric damper" means a device designed to 

maintain a constant draft In a furnace or boDer. 

1.11 "Ajr shutter" means an adjustable device for \-arying the size of the primary 

air lnIetCs) to the combustIon chamber or power burner. 

1.12 "Power burner" means It furnace 

burner whJch supplles air for combustion at a Pre5SUre exceeding atmospheriC pressure, or a burner whJch depends on the draft induced by a fan Incorporated In the furnace 

lor proper operation. 

1.13 "Vent llmlter" means a device which 

lImIts the 1low of air from the atmospheriC diaphragm chamber of a gas pressure regulator to the atmosphere. A vent llmlter may 

be a llmltlng orifice or other llmltIng device. 

1.14 ''Vent/alr Intake tennIna!" means a. device whJch Is located on the outside of a. buUdlng and Is connected to a. furnace by a. system of conduit.!. It Is composed of an air 

Intake termlnal. through whJch the all- for 

combustion Is taken from the outside atmosphere, and an exhAust tennlnal from 

whJch 1lue p.ses are dIscharged. 

1.15 "ResIstance heatfng element" means the electrical conducting medium whJch Is 

Intended to be heated by an electric current 

and whJch dIssIpates thIs heat Into the air 

or water. 

1.16 "Induced draft" means drawing air 

Into the combustion chamber by mechanical means. 

1.1'1 "Plenum" means an air compartment, that Is attached to, or Is an Integral 

part of a forced air furnace and which Is designed to eIther dIstribute the heated air 

after It leaves the heat exchanger In the case of a IiUpply plenum. or conects the air 

whJch enters the return lnIet In the case of a return plenum. 1.18 ''Heat Input" (Q.,.) means the rate of 

energy IiUppUed In a fuel to a. furnace, oper- ating under steady state conditions. expreued In Btu's per hour. It Includes any 

Input energy to the pOot llght and Is obtained by multiplying the measured rate cif 

fuel consumption by the measured hJgher 

heating value of the fueL 

1.19 ''Draft hood" means a device that Is 

not an Intei1'&! part. of the furnace or boiler, 

and whJch Is connected to the furnace or boner by a short length of !lue pIpe. It Is desJgned to (1) provide for the exhaust of the 

products of combustion In the event of no draft, back draft, or stoppage beyond the 

draft hood. (2) prevent a back: "draft from 

entering the furnace. and (3) neutrallze the 

eUect of stack action of the chImney or gas 

vent upon the operation of the furnace. 

FEDERAL REGISTER, VOL '43, NO. 91-WEDNESDAY, MAY 10, 1978 
20156 

1.20 "Higher heating value" (HHV) 

means the heat produced per unit of fuel 

when complete' combustion ,takes place at ' 

constant pressure and the products of com· bustion are cooled to the initial temperature of the fuel and air" and when the water 

vapor formed during combustion is con· densed. The higher heating value is ex- pressed in Btu's per pound, Btu's per cubic 

foot for gaseous fuel, or Btu's per gallon for 

liquid fuel. 

1.21 "Integral draft dIverter" means a device that is an Integral part of a furnace 

and which is designed to (1) provide for the 

exhaust of the products of combustion In 

the event of no draft, back draft, or stop· 

page beyond the draft dIverter, (2) prevent a back draft from entering the furnace, (3) 

neutralize the effect of stack action of the 

chimney or gas vent upon the ol1eratlon of 

the" furnace. . 1.22 "Stack damper" is a device fnstalled 

downstream of the integral draft dIverter, 

draft hood, or barometric draft< regulator and which is designed to automatically open tlie venting system when the appliance is In 

operation and to automatically close off the 

venting system when the appliance is in a standby condition. 

1.23 "Flue damper" is a device installed 

between the furnace and the Integral draft 

dIverter, draft hood, barometric draft regu· lator or vent terminal. on a unit, not 

equipped with a draft control device and 

which is designed to automatically open the 

venting system when the appliance is in op· eration and to automatically close-off the 

venting system when the appliance is in a standby condition. 

1.24 "AIr tube" means a tube which car· ries combustion air from the fan to the 

burner nozzle for combustion:. 

1.25 "Infiltration parameter" means that 

portion of unconditioned outside air drawn 

Into the .heated space as a consequence of 

loss of ,conditioned air through the exhaust 

system of a furnace or boller. ' 

1.20 "Vent pipe" means passages and 

oonduits In a direct vent system through whioh gases pass from the combustion 

chamber to the outdoor air. 

1.27 "Heating capacity" (Qout) means the 

rate of useful heat output from a furnace. 

operating under steady state conditions. e~ 

pressed In Btu's per hour. For furnaces in· 

; teIl.ded to be installed Indoors It is obtained 

by multiplying the "heat Input" (QIn) by the 

steady state efficiency (1) .. > divided by 100. 

For furnaces Intended to be installed outdoors It is obtained by multiplying (A) the 

"heat Input" (QIn) by (B) the difference of 

the steady state efficiency divided by 100 

and the quantity (3.3) (LI) divided by 100, 

where LJ is the jacket loss as determined In 

3.4 of this appendix. 

2.0 Testing conditions. 

2.1 Installation 0/ test plenum, duct 

work, and piping. , 2.1.1 Gravity central furnaCes (including direct vent systems). Install and equip grav- ity central furnaces with a vertical supply 

test plenum or extended casing and horizon· 

tal test ducts as described In section 2.9.1 of 

ANSI Standard Z21.47-1973. 

2.1.2 Forced' air central furnaces (lnclud· 

Ing direct vent systems). Equip gas·fueled 

forced air central furnaces with a plenum and test duct as described In Sections 2.1.9 

and '2.1.10 of ANSI Standard Z21.47-1973. 

Equip oll fueled forced air c;entral furnaces 

with a plenum !1lld test duct as described in 

Section 6.2 of ANSI Standard Z91.1-1972. 

2.1.3 Low pressure steam and hot water 

bollers <including direct vent systems). In· 

RULES AND REGULATIONS 

stall gas-fueled low pressure steam ana hot 

water bollers as prescribed In section 2.9 of 

ANSI Standard Z21.13-1974. Install oll· 

fueled low pressure steam and hot water 

bollers as prescribed In sections 7.0 and 8.1.1 

through 8.1.3 of the HydronIc Institute 

Testing and Rating Standard for Cast Iron 

and Steel Heating Bollers. January 1977 edi· 

tion. 

2.1.4 Electric central furnaces. IristalI 

equipment for testlni in acCordance with 

ARI Standard 280-74. section 4 and figure 1. 

2.1.5 Electric bollers. , Install· equipment In accordance with 

manufacturer's instructions. 

2.2 Flue and Stack Require1nents , 2.2.1 Gravity and Forced air central fur· naces. 2.2.1.1 Gravity and gas fueled forced 

air central furnaces employing Integral 

draft diverters. 

Attach to. and vertically above. the di· 

verter outlet of gas fueled gravity and 

forced air central furnaces employing draft 

dIverters with vertically discharging outlets. a test stack having a- length of five (5) feet 

and a- cross sectional area the same size as the furnace outlet. Cciver the teSt stack with 

insulation having an R value of not less 

than 7 ("F-HR-ft"/Btu) and an outer layer of aluminum foil. Attach a- 90 degree elbow 

and a- vertical test stack 5 feet long to the 

diverter outlet of furnaces employing draft 

diverters with horizontally discharging outlets. Cover the elbow and test stack with in· 

sulatlon having an R value of not less than 

7 ('F-HR-ft 2/Btu) and an outer layer of 

aluminum foiL 

2.2.1.2 Gm; fueled. gravity and forced air 

central furnaces which employ draft hoods. 

Test gaS fueled gravity and forced air cen· tral furnace:1 which employ draft hoods 

having vertically discharging outlets with 

the draft hood iIi place and a five foot long insulated pipe attached to the hood outlet. 

-Test, gas fueled furnaces having a- horizon:. 

tiilly discharging hood outlet. with the draft 

hood in place and an insulated elbow and a five foot long vertical insulated pipe attached to the hood outlet. Insulate. with in· 

sulation having an R value not less than 7 

('F-HR-ft'/Btu) and an outer layer of aluminum foll. Use an elbow and pipe with a- cross sectional area the- same sIze as the 

hood discharge outlet. 

2.2.1.3 Oil fueled forced air central fur· naces. 

Flue connections,for oll fueled forced air 

central furnaces are to be as described in 

Figures 1 and 2 of ANSI Standard Z91.1-

1972. Use elbows and flue connections with 

the same cross sectional area as the furnace 

outlet and covered as described in Figure 2 

of ANSI Standard Z91.1-1972 with insulation having an R value not less than 7 <"FHR-ft'/Btu) and'an outer layer of alumi· num foil. Allow no opening between the fur· nace and the point where the flue gas , sample is to be taken or the flue gas tem· 

perature is to be measured. If a barometric 

draft regulator is incorporated in the fur· 

nace, seal it during all tests. 

2.2.2 Gas and oil fueled low pressure 

steam and hot water bollers (not Including direct vent systems). Set up gas fueled low 

pressure steam and hot water bollers em·- ploylng draft diverters with the same flue 

and stack arrangement described In section 

2.2.1.1 for gas fueled furnaces with draft di· 

verters. 

Set up gas fueled low pressure steam and 

hot water bollers employing draft hoods 

with ihe same flue and stack arrangement described in section 2.2.1.2 for gas fueled 

furnaces with draft hoods. 

Flue connecUons for oll fueled low pres- sure steam and hot water bollers are tho same as those described in section 2.2.1.3 for 

oil fueled forced air central fUrnaces. 

2.2.3 Direct vent systems. Keep tho vent/ 

air intake System supplied by tho manUfacturer in place during all tests. Test uniw in· 

tended for installation with a variety of 

vent pipe lengths with the minimum vent 

length recommended by the manUfacturer. 

Do not connect a- furnace or boller employIng a- direct vent system to a chimney or in· 

duced draft source. Vent combustion products solely on the provision of venting incorporated in the furnace and the vcnt/air 

intake system supplied with it. On units 

which are not designed to significantly preheat the incoming air. insulate the firot 18 

inches of vent pipe downstream of tho fur· nace outlet with a layer of insulation llaving an R value of 7 ('F-HR-fto/BtU) covered 

with a layer of aluminum foll. Care should 

be taken not to block the air intake with insulation. For units designed to significantly preheat the incoming combustion air cover all surfaces of the vent/air intake system exposed to ambient air with insulation 

having an R value not less than 7 ('F-HRft 2

/Btu) and a layer of aluminum foll, Where 

the combustion air temperature exceeds tho room temperature by more than 30' F <10.70 

C'). 

2.3 Fuel supplv. 

2.3.1 Natural gas. For a furnace utiUzlng natural gas. maintain the gns supply to tho 

unit under test. at a normal inlet test pres· sure of 7 to 10 inches water column immedi· 

ately ahead of all controls. Maintain tho 

Tegulator outlet pressure at normal test 

pressure approximMely at that recommended by the manufacturer. Use natural gns having a specific gravity of approximately 

0.65 and a higher heating value within ±5% 

of 1025 Btu per standard cubio foot. Dotormine the actual higher heating valuo in 

Btu's per standard cubic foot for the natu· 

ral gas to be used in the test with im errol' no greater than one percent. 

2.3.2 Propane gas. For a furnaco er boUer 

utllizing propane gns, maintain the gas 

supplY' to the unit under test at a normal 

inlet pressure of 11 to 13 inohes water 

column. Immediately ahead of all controltl 

maintain the regulator outlot pressure. on units so equipped. approximately at that 

recommended by the manUfacturor. Use 

propane HD-5 having a speclfio gravity 01 

approximately, 1.53 and a higher heating 

value within ±5% of 2500 Btu's per stnnd· 

ard cubic foot. Determine the actual higher heating value in Btu's per standard oubio 

foot for the propane to bo used in tho test 

with an error no greater than ono percent. 

2.3.3 Other test gas. The speclfio gravity of other test gases shall approximate tho 

values given in Table IX of ANSI Stnndard 

Z21.47-1973. Maintain the test pressures im· 

mediately ahead of all controls betwellli tho 

"normal" and "increased" values 01 test 

pressures given in Table X in the ANSI 

Standard. Use cas with a measured higher . heating value within ±5% of the values 

specified In Table IX of ANSI Standard 

Z21.47-1973. Determine the aotual higher heating .value of the gas used in the test 

with an error no greater than 1 percent. 

2.3.4 Oll supply. For a furnace or boUor 

utlllzfng fuel oil. use fuel oil No.1 or No.2 

conforming to the specifications outlined in 

Tables 2 and 3 of ANSI Standard ZOl.l1972. Measure the higher heating ValUo of 

the test fuel oil With an error no greater than one percent. 

fEDERAL REGISTER, VOL. 43, NO. 91-wi:Dt~ESDAY, MAY 10, 1978 
2.3.5 Electrical supply. For an electric 

furnace or boiler. or for an auxiliary electric 

component of a gas or oil fueled furnace or boiler. maintain the electrical supply to the 

test unit within one percent of the name- plate voltage for the entire duration of the 

test. If a voltage range is used for nameplate 

voltage. maintain the electrical supply 

within one percent of the center of the 

nameplate voltage range. 2.4 Burner adjustments. 

2.4.1 Gas Burner adjustments. Adjust 

burners of gas fueled furnances or boilers to 

their maximum Btu ratings at normal test 

pressure specified in 2.3 of this Section. Correct the burner input rate to 60' F and 30 

inches of mercury barometric pressure and 

within ±2 percent of the hourly Btu rating 

specified by the manufacturer. as measured 

after 15 minutes of operation starting with 

all parts of the furnace at room temperature. Set the primary air shutters in accordance with the manufacturer's recommendation.to give a good flame at this adjustment. 

If. however, the setting results in the deposit of carbon during any test specified herein, 

the tester shall adjust the shutters and 

burners until no more carbon is deposited 

and shall perform the tests again with the new settings. 

If a vent limiting means is provided on a gas pressure regulator. keep it in place during all tests. -

2.4.2 Oil burner adjustments. Adjust the 

burners of oil fueled furnaces or boilers ,to 

give the CO. reading recommended by the 

manufacturer and an hourly Btu input 

during the steady·state performance test described below which is within plus or minus 

2 percent of the furnace manufacturer's 

specified normal hourly Btu input rating. 

Smoke in the flue may not exceed a No.1 

smoke during the steady-state performance 

test as measured by the procedure in ANSI 

Standard Zll.182-1965 (R1971> (American 

Society for Testing and Materials D 2156-65 

(1970». Maintain the average draft over the 

fire and in the flue during the steady·state 

performance test at that rewmmended by 

the 'manufacturer. Do not allow draft fluctuations exceeding 0.005 inches of water 

gauge. Do not make additional adjustments 

to the burner during the required series of 

performance tests. The instruments and 

measuring apparatus for this test are desonDed in section 6.3 of ANSI Standard 

Z91.1-1972. 

2.5 Circulating air, steam, or water flow 

adjustments. 

2.5.1 Gas fueled forced air central furnaces (including direct vent Systens). 

Adjust the external static pressure arid air - flow rate as specified in sections 2.1.11. 

2.1.12. and 2.1.13 of ANSI Standard Z21.47-, 

1973. Measure outlet air temperature in ac- cordance with section 2.1.9 of the same standard. 

2.5.2 Gravity central furnaces (including 

direct vent systems). Maintain the air flow 

rate through the furnace such that the 

average normal air temperature rise at 

steady-state is not greater than 130' F above 

the inlet air temperature when the furnace 

is equipped with the vertical test plenum of 

extended casing and horizontal test ducts as described in section' 2.1.1. Measure the 

outlet air temperature as specified in sec- tion 2.9.1 of ANSI Standard Z21.17-1973. 

Measure the inlet air temperature measured 

at the center of the plane of each inlet air 

opening by means of a single No. 24 Ameri- can Wire Gauge CAWG) thermocouple. suitably shielded from direct radiation. 

",J~H AND REGULATIONS 

2 5 3 OU fueled forced air central fur- naces (including direct vent systems). 

Adjust the external static pressure and air 

flow rate as specIfIed in table 5 and section 

6.2 of ANSI Standard Z9l.1-1972. 

2.5.4 Gas and on fueled low pressure 

steam and hot water boners (Including 

direct vent systems). For hot water boDers. 

adjust the water flow rate to produce a 

water temperature rise. during steady·state 

operation, of between 120' F (48.9 C) and 

165' F (73.9 C) and an outlet water temperature of 200' F (93.3 C) plus or minus 5' F 

(2.8 C). For steam boilers. conduct the 

steady·state performance test described in 

3.1 at atmospheric pressure or at a pressure 

not exceeding 2 pslg. 

2.5.5 Electric central furnaces. Use the 

air quantity and pressures specified by the 

Air Conditioning and Refrigeration Institute CARr) Standard 280-74. section 6.2.1 

and 6.2.3. 

2.5.6 Electric boUers. Adjust the flow of 

water or steam as specified in section 2.5.4 

for gas and on fueled boUers. , 2.6 Location oJ temperature measuring 

instrumentation. 

2.6.1 Gas fueled gravity furnaces. forced 

air furnaces, and boners (including direct 

vent systems). For units employing an intergraI draft dIverter. install nine thermocouples. wired in parallel. in a horizontal plane 

in the 5-foot test stack located 1 foot from 

the test stack inlet. Equalize the length of 

all thermocouple leads before paralleling. 

Arrange the thermocouples in a grid with one thermocouple in the center of the test 

stack, and eight thermocouples along ImAginary lines intersecting at right angles in the 

horizontal plane at points one-third and 

two-thirds of the distance betweeen the 

center of the pipe and the pipe wall. 

For units which employ a draft hood. or a direct vent system which does not slgnUlcanUy preheat the incoming combustion air. 

install nine thermocouples. wired in parallel. in a horizontal plane located within 12 

inches (304.8 rom) of the furnace or boUer 

outlet. and upstream of the draft hood on units so equipped. Equalize the length of all 

thermocouple leads before paralleling and 

arrange the thermocouples as described 

above. 

For funaces or boners which employ 

direct vent systems that signIficantly preheat the incoming combustion air. install 

nine thermocouples. wired in parallel. in & 

plane parallel to and located within 6 Inches 

<152.4 mm) of the vent/air lntnke terminal. 

Equalize the length of all thermocoupleleads before paralleling and arrange the 

thermocouples as described above. 

Use bead· type thermocouples ha~ wire 

size not greater than No. 24 AWG. If there 

is a possibility that the thermocouples could 

receive direct radiation from the flame. install radiation shields on the flame side of 

the thermocouples onlY and position the 

shields so that they do not touch the thermocouple junctions. 

Locate the thermocouples used for meas- uring conditioned warm air as described in 

ANSI Z21.47-1973. sections 2.1.9 and 2.9.1. 

Measure the temperature of the inlet air by means of a. single No. 24 AWG bead·type 

thermocouple. suitably shielded from direct 

radiation and located in the center of the 

plane of each inlet air opening. 

Measure the inlet and outlet water temperature on gas fueled hot water boDers as shown in figure 3 of ANSI Standard Z21.13-

1974. 

2.6.2 au fueled forced air central fur- naces and boUer3 (including direct t:ent SNI20157 

terns). Install nine thermocouples. wired in 

parallel and hamg equal length leads. in a plane perp€ll;llcular to the axis of the flue 

pipe. For systems other than direcl; vent systems which slgnUfcantly preheat the incoming air. locate this plane at the position of 

the single thermocouple shown in figure 2 

of ANSI Standard Z91.1-19-72. For direcl; 

vent systems which significantly preheat 

the incoming air. locate the plane within 6 

inches <152.4 mm) of the outlet of the venti 

air intake terminal. Arrange the thermocouples as described in section 2.6.1-

Use bead·type thermocouples having a wire sIze not greater than No. 24 AWG_ If 

there is a poafbility that the thermocouples 

could reeelve direct radiation from the 

flame. install radiation shields on the flame 

slde of the thermocouples only and position, 

the shields so that they do not touch the 

thermocouple junctions. 

Locate the thermocouples for measuring 

conditioned warm air as described in section 

6.2 of ANSI Standard Z91.1-1972. Measure 

the temperature of the inlet air by means of 

a single thermocouple. suitably shielded 

from direcl; radiation and located in the 

center of the plane of each inlet air opening. 

Measure the inlet and outlet water temperatures on on fueled hot water boilers as - described in section 7.4 and fIgure 2 of the 

January 19'17 edItlon of the Hydronic Institute Standard ''Testing and Rating Standard for Cast Iron and steel Heating Boilers." 

2.6.3 Electric f'Kmaca. Install nine thermocouples, wired in parallel and having 

equal length leads. as shown in figure 1 of 

ARt Standard 280-74. for measurIng the 

conditioned warm air temperature. Establlsh the temperature of the inlet air by means of & slngle thermocouple suitably 

shielded from radiation and located In thecenter of the plane of each inlet air opening. Use bead-type thermocouples having a wire size not greater than No. 24 AWG_ 

2.6.4 Electric boUen. Measure the inlet 

and outlet water temperatures on electric 

hot water ooUers as speclfied in section 2.6.2 

for on fueled hot. water boilers. 

2.7 Combustion measurement irutrumentation. Analyze the samples of stack and 

flue gases for furnaces and determine the 

concentration by volume of carbon dioxide 

present in the dr.Y stack or 1lue gas. with instnunentation providing readings with an accuracy of ±0.1 percentage points. 

2.8 Energy flow imtrumentation. IDstall one or more instnunents. which measure. as appropriate. the rate of electrical energy 

combustion, gas flow. or fuel on SllPplled to 

the furnace or boiler. with an error no greater than one percent. 

2.9 l«lom ambient temperature. DurIng 

the time period required to perform all the t~ and measurement procedures specIfied In sectfon 3.0. maintain the room temperature within ±5" F (+2.8 C) of the value 

Tu measured during the steady state performance test. DurIng these tests. the room temperature may not exceed 100· F (37.8 C) 

or fall below 65' F <18.3 C). Use the procedure ouUlned in section 2.1.14 of ANSI 

Standard Z21.47-1973 to measure room temperature. 2.10 Equipment 1l.!ed to measure ma.u 

flow JUte in flue ancl alack. The tracer gas 

chosen for this task should have a density 

which is less than or approximately equal to 

the density of air. Use a gas that. Is of a different chemlcal specIes or dl!!erent concen- tration from the flue gas to be measured 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1918 
20158 

and unreactive with the environment to be 

encountered. Using Instrumentation of 

either the batch or continuous type, meas- ure the concentration of tracer gas wIth an accuracy of ±2 percent of the value of the 

concentration measured. 

3.0 Testing and measurements. 

3.1 steady-state testing. 

3.1.1 Gas fueled gravity furnaces. forced 

air central furnaces, and low pressure steam 

and hot water boilers (including direct vent 

systems). The following procedure is to be 

used for gas fueled gravity furnaces, forced 

air central furnaces, and boilers (including 

direct vent systems). Set up the furnace or boUer as specifIed In 

sections 2.1., 2.2, and 2.3. Begin the steadystate performance test by operating the, 

burner and the Circulating air blower or water pump, with the adjustments specified 

by 2.4.1 and 2.5, until steady-state conditions are attained as Indicated by a temperature variation of not more than-(1) 3' F 

(1.7C) In the stack gas temperature for fur- naces and boilers equipped with draft diverters (2) 5' F (2.8C) In the flue gas temperature for furnaces and boilers equipped 

with either draft hoods, or direct vent systems, and (3) 4' F (2.2C) In the outlet water 

temperature for hot water boilers; In three 

successive readings taken 15 minutes apart. On units employing draft diverters, meas- ure the room temperature (TRA) as described 

In 2.9 and measure the steady-state stack 

gas temperature (T •. ss.

x) using the nine thermocouples located In the 5 foot test stack as described In 2.6.1."Secure a sample of the 

stack gases In the plane where T ..... x is 

measured and determine ,the concentration -by volume of carbon dioxide (Xco ... ) present 

In dry stack gas. On units employing draft hoods or direct 

vent Systems, measure the room temperature (TRA) as described In 2.9 and measure the steady-state flue gas temperature, (TF•SS•X) using the nine thermocouples 

located in the flue pipe as described'in 

Section 2.6.1. Secure a sample of the 

flue gas in the plane of temperature 

measurement and determine the concentration by volume of C02CXCO,.F) 

present in dry flue gas. Detcrmlne the steady-state heat Input 

rate (QID)' including pilot gas, by multiply- Ing the measured higher heating value of 

the test ~ by the steady-state gas Input 

rate corrected to standard conditions of 60' 

F and 30 Inches of mercury. Use measured 

values of gas temperature and pressure at 

the meter and the barometric pressure to 

correct the metered gas flow rate to standard conditions. 

Measure the steady·state electric power to 

the power burner (PE) on units so equipped. 

For furnaces, measure the steady-state electrical power to the conditioned air blower 

(BE). For hot water boilers, use a steady 

state water pump power of 0.13kW. 

After the above test measurements have 

been complete on units employing Integral 

draft diverters, secure a sample of the flue 

gases at the lnIet to the draft diverter and 

determine the concentration of CO, (Xco..p) 

present. In obtaining this sample of flue 

gas, move the sampling probe around to assure that an average value is obtained for, 

the CO. concentration. For units with multi-

'pIe heat exchanger outlets, draw and weIght a sample from each outlet, to' obtain the 

average CO. concentration for the unit. 

Block the draft diverter relief opening and cover the draft dlverter and flue gas collection box (on a power vented unit) with insulation having an R value no less than 7 ('FRULES AND REGULATIONS 

HR-ft'/Btu) and an outer layer of alumi- num foil. If the unit is turned off during the 

process of blocking the diverter relief open- Ing, run It wltil steady-state conditions (as 

defined above) are again achieved. Progressively restrict the test stack outlet until the 

concentration of CO. In flue gaS samples se-' 

cured from the test stack In the plane where' 

Ts .... x was measured is within ±0.2 percentage points of the previouSly determined 

value·of Xco. ••• Measure the flue gas temperature (Tp•lIS) using the nine thermocouples located In the 5 foot test stack as described In 2.6.1. 

3.1.2 Oil fueled forced air central fur- naces and low pressure steam and hot water 

boilers (including' direct vent systems). Set 

up!and adjust the furnace or boiler as specI- fied In sections 2.1, 2.2 and 2.3.4. Begin the 

steady-state performance test by oper!Ltlng 

the burner and the circulating air blower or water pump with the' adjustments specified 

by 2.4.2 and 2.5 until steady-state conditions are attained as Indicated by a temperature variation of not more than-(1) 5' F (2.8C) 

In the flue gas temperature for furnaces and 

boilers and (2) 4' F (2.2C) In the outlet 

water temperature for hot water boilers; In 

three successive readings taken "15 minutes 

apart. 

Smoke In the flue for units equipped with 

power burners, may not exceed a No. 1 

smoke during the steady-state performance 

test as measured by the procedure described 

In ANSI St:mdard ZI1.182-1975 (RI971> 

(ASTM D 2156-65 (1970». MaIntaIn the 

average draft over the fire and In the 

breeching dw.:Ing ~he steady-state perform- ance test at that recommended by the man- ufacture:t:. Draft fluctuations may not 

exceed 0.005 Inches of water gauge. Measure the room temperature (TRA) as described In 2.9 and measure the steady' 

state flue gas temperature (Tv ... ) using nine 

thermocnuples' located In the flue pipe as described In 2,6.1. Secure a sample of the 

flue gas In the plane of temperature mea· surement and determine the concentration 

by volume of CO. (Xco...) present In dry flue 

gas. • 

Measure and record the steady-state heat 

Input rate (Q'D) and the steady-state electrical power to the power burner (PE) on units so equipped. For furnaces, measure the 

steady-state electrical power to the conditioned air blower (BE). For hot water boil- ers. use a stee.dy-state water pump power of 

BE=0.13kW. 

• 3.1.3 Electric forced air central furnaces. 

Measure the rated power Input (Em) of electric furnaces ILccording to the test procedure 

specifIed In ARI Standard 280-74, section 

5.1. Take all measurements at the standard 

rating condition described In 6.2.1 of ARI 

Standard 280-74. Supply electricitY as speci- - fled In section 2.3.5 of this appendix. 3.1.4 Electlic boilers. Adjust flow conditions as specified In section 2.5.4. MaIntaIn 

electrical supply as specified In section 2.3.5. 

Operate the boiler until steady state conditions are reached as Indicated iIi section 1.2 

of this appendix:Take three measurements 

of the total power Input to the boiler each 

at a 10-mlnute Interval, and average the 

measurements to find the rated power Input 

(EID). 

3.2 Flue temperature measurements-cool 

down test. 

3.2.1 Gas and oil fuel gravity and forced 

air central furnaces (including direct vent 

systems). Turn off the maIn burner alter 

steady-state testing is completed, and meas- ure the flue gas temperature~ by means of 

the 9 thermocouples described above, at 1.5' 

(Tr.o"<t.» and 9.0 minutes (Tr.on(t.» after 

the burner shuts of!. BY-pass the damper control In units employing stack dampers and Integral draft diverter or draft hood so that the damper remaIns open during the 

cool down test. 

During this off·period, allow a time delny. 

t+, between burner shut down and blower 

shut down of either 3 minutes or unm the 

supply air temperature drops to a v!\luo of 

40' F (22.2C) above the lnIet air tempern' 

ture, whichever results in the longest blower on time. However, if the furnace employs a single motor to drive a power burner and lin 

Indoor air circulating blower. turn oft the 

blower and the burner together. If the 

blower delay time exceeds 3 minutes, meas- ure the time t+ between burner shut off and 

blower shut of! uslng'a stop watch. For oU 

fueled furnaces not equipped with stack 

dampers, maintain the draft in the flue pipe 

within a range of -0.001 and +0.005 inches 

of water gauge of the average draft main· 

taIned during the steady state test described 

In 3.1 if the optional test in 3.6 is being car· ried out, or within ±0.01 Inches of water 

gauge of the average steady·state dralt U it 

is not. For a direct vent system with a flue 

damper or a furnace equipped with both a stack damper and a barometric damper. 

close the flue or stack damper during tho 

cool down test. Keep the main burnor(s) ort 

until equilibrium conditions are attained, as Indicated by variations in the flue gas temperature of not more than 3' F (1.7C) be· 

tWllen three successive readings taken 15 

minutes apart. For units employing a con· tlnuously burning pilot light, take a third 

flue gas temperature measurement and determine the off·perlod minimum flue gas 

temperature (Tr.oFF. (00». For units not em· ploylng a continuously burning pilot light, 

set (T,F.OFF. (00» equal to the room temperature TRA• During this cool down test. mellS' ure the energy Input rate to the pilot light 

(Qp), if the unit is so eqUipped, within lin nco curacy of ±3%. Record all measured values. 

3.2.2 Gas and oil fueled boilers (includlrtg 

direct vent Systems), Alter steady-state testing has been' completed, turn the main 

burner(s) off and measure the flue gM tem· 

perature at 3.75 (Tr.on(t.» and 22.5 

(T ... o..<t.» minutes after the burner shuts 

off, using the 9 thermocouples described 

above. During this off ·period, do not allow 

water to circulate through the hot water 

boilers. Make a third flue gas temperaturo 

measurement 45 minutes after the burner 

shuts off to determine the off·perlod mini· mum flue gas temperature (Tr.on, (00». 

During this cool·down test, measure the 

energy Input rate to the pUot light (Qp). U 

the unit is so equipped, to within an accura- cy of ±3 percent. Record all measured 

values. For oll fueled units not eQuipped 

with stack dampers, maintaIn the draft in 

the flue wIthin the same ranges called out 

In section 3.2.1 above. For dlreet vent sys· 

tems with flue dampers or boilers equipped with both stack dampers and barometric 

dampers, close the flue or stack damper during the cool down test. 

3.3 Flue gas temperature'measuremcnlsHeat-up test. 

3.3.1 Gas and oil fueled centtaI furnaces 

(including direct vent systems). Alter eQui· 

librium conditions are .achleved following the cool·down test and the required mea· surements performed, turn on the furnace 

and measure the flue gas temperature using the 9 thermocouples described above, at 0.5 

(Tr.oN(t,» and 2.5 (Tr.oN(t.» minutes after 

the maIn burner(s) comes on. After the 

burner start-up, delay the blower st!lrl-up 

FEDERAL REGISTER, VOL 43, NO: 91-WEDNESDAY, MAY 10, 1978 
by 1.5 minutes (t->, unless-(l) the furnace 

employs a Single motor to drive the power' 

burner and the indoor air circulating blower, in which case the burner and blower 

shall be stll.rted together or (2) the delay 

time would result in the activation of a temperatUre safety device which shuts off the 

burner, in which case the fan control shall 

be permitted to start the blower. In the 

latter case, if the fan control is adjustable, 

set it to'start the burner at the highest temperature. If the fan control is permitted to 

start the blower, measure the time delay, t-, 

uSing a stop watch. Record the measured 

temperatures. During the heat up test for 

oil fueled furnaces, maintain the draft In 

the flue pipe within ±0.01 Inches of wat€r 

gauge of the manufacturer's recommended 

on-period draft. 

3.3.2 Gas and oil fueled boilers (Including direct vent systems). Fifty minutes after the 

main burner
 is turned off for the cool 

down test, turn on the steam or hot wat€r 

boiler and measure the flue gas temperature 

using the 9 thermocouples described above, 

'at 1.0 (TF.olo.(t.» and 5.5 (TF"O~.(t.» minutes 

after the main burner<s) comes on. Start 

the pump circulating the water through the 

hot water boiler simultaneously with the 

main burner
 and maintain the water flow 

rate at that maintained during the steady 

state test descnlJed In Section 3.1. During the heat up test for oil fired boilers, maintain the draft in the flue pipe within ±0.01 

inches of water column of the manufacturer's recommended on-period draft. Record 

the measured temperatures. 

3.4 Jacket loss measurement. For units 

intended to be installed outdoors or In a un- heated space perform a jacket loss test. 

Measure the jacket loss {1.,> in accordance 

with the following ANSI standards and 

record the total loss and ambient room temperature during the test: 

(i) Gas fueled gravity and forced air cen- tral furnaces-Z21.47-1973, section 2.9.1 and 

appendixF. 

(ii) Gas and oil fueled low pressure steam 

and hot water boilers-ANSI Z21.47-1973, 

section 2.9.1 and appendix F. 

(iii) Oil fueled forced air central furnaces-Z91.1-1972, appendix B. 

3.5 Measurement for detennining effectiveness of automatic stack damper. Meas- ure the cross sectional area of the stack 

{As>, the net area of the damper plate (An) 

{the area of the damper plate minus the area of any holes in the plate>, and the 

angIe {n> the damper plate makes, when 

closed, with a plane perpendicular to the 

axis of the stack. 

3.6 Optional procedure for detennining 

Dp, DF, Ds for systems equipped with pou:er 

burners. On power burner systems not em- ploying automatic stack dampers, or power burner systems with a stack damper and a draft diverter or draft hood, measure D, 

(the ratio of gas mass flow rate through the 

flue during the off-cycle to the gas mass flow "rate though the flue during the on- cycle at identical temperatures) during the 

cool down test described In Section 3.2. On 

systems for which the flue or stack damper 

is t{) be closed during the cool down test descnlJed in section 3.2, measure n.. (the ratio 

of the rate of flue gas mass flow through the furnace during the off-period to the 

rate of flue gas mass flow through the fur- nace during the on-period> during a separate cool down test. Conduct this separate cool down test after the heat up test described in section 3.3 is completed by run- ning the unit after the heat up test until 

. RULES AND REGULAnONS 

steady-state conditions are reached, a.s indicated by a temperature variation of not more than-(l) 5" P (2.8 C) In the flue ,as 

temperature for furnaces and bollers, and 

(2) 4° P·{2.2 C) In the outiet water temperature for hot water bollers; In three successive readings taken 15 minutes apart. and 

then shutting the unit off with the stack or flue damper controls by·passed or adjusted so that the stack or flue damper remains 

open during the resulting cool down period. 

If a draft was maintained on oU furled units 

In the flue pipe during the steady·state performance test described In section 3.1 maintain the same draft (within 0.001 and 

+0.005 Inches of water gauge of the average steady·state draft) during this cool down 

period. Measure the flue gas mnss flow rate 

(mFo017> during the cool down test described 

above at a m>ecWc off·perlod flue gas temperature and correct to obtain Its value at 

the steady·state flue gas temperature (Tr.sa>, 

using the procedure described below. 

Within 1 m1nut€ after the unit Is shut oU 

t{) start the cool down test for determining 

Dr. begin feeding a tracer gas Into the com- bustion chamber at a constant flow rate of 

VTo and at a point which will allow for the 

best possible mlxIng with the air flowing through the chnmber. (On units equipped 

with an oil fired power burner the best location for injecting this tracer gas appears to 

be through a hole drilled In the air tube). 

Periodically measure the value of VT with an instantaneously reading flow meter 

having an accuracy of ±3 percent of the 

quantity measured and maintain that value 

at less than 1 percent of the air flow ratc 

through the furnace. If a combustible tracer 

gas is used, there should be a delay period 

between the time the unit is shut off and 

the time the tracer gas is first injected to 

prevent JgnItion of the tracer gas. 

Between 5 and 6 m1nut€S after the unit is 

shut off to start the cool down t€St. measure the flue gas temperature, Tr.-crr. usIn~ the 9 

thermocouples described above. At the same time the flue gas temperature is measured, measure the percent volumetric concentration of tracer gas, Cr. In the flue gas In the same plane where Tr.-GJ1'. Is determined. 

Obtain the concentration of tracer gas using an lruitrument which will result In an accuracy of ±2 percent In the measured value of ~ If the use of a continuous readings tl'JlC 

instruments results In a delay time between 

drawing of a sample and Its analysIs, take 

this delay Into account so the temperature 

measurement and the me3SUrelI1ent of 

tracer gas concentration coincIde. Determine the temperature of the tracer gas en- t€ring the flow (TT) and the barometric 

pressure {Pal. 

The rate of the flue gas mass flow 

through the furnace and the factors Dr. Dr> 

and Da are calculated by the equations In 

sections 4.4.1, 4.4.2, and 4.4.3 of this appendix. 

4.0 Calculation of derIved results from 

test measurements. 

4.1 Annual fuel utilization efficIency for 

electric furnaces and bollers. Tho annual 

fuel utillzation efficIency for electric fur- naces and bollers. EFFY ... -E> is gi",en by: 

EFFY ... -a=100 (for Indoor units>. 

EFFY ... -z=100-3.3 1., (for electric forced 

air central furnaces Intended lor outdoor installation). 

EFFY ... --.=100-4.'1 1., (for electric bollers 

Intended lor outdoor installation). 

where 

1.,=the jacket loss as det€1'D1lned In sec- tion 3.4 of this Appendix,ln percent. 

20159 

4.2 Annual fuel utilization efficiency for 

gcs or aU furnacu. Perform the following 

calculations to det€1'D1lne the annual fuel 

uUlJzation efficIency of a gas or on furnace. 

Figure 10 provides an illustration of a worksheet which may be used to tabulate the re- !Ults 01 test measurements and calculations. 

4.2.1 System number. Determine the 

system number for the type 01 furnace 

being tested In accordance with table 1 or 2-

4.2.2 Ration 01 combustion air to stoIchiometric air. Determine the ratio of com- bustion air mass flow rate of stplchlometrfc 

air mass flow rate. Rr.Po for the test fuel 

from Figure 1 by u.slng the value of dry flue 

i&S CO. concentration, ~, determined In 

accordance with section 3.1 of this appendix. 

4.2.3 Ratio o! combustion and relief air 

to stoichiometric air. For a system employIng an Integral draft diverter. or draft hood, 

determlne the ratio of the sum of combustion and rellef air ma.<s flow rate stoichiometric air mass flow rate. RyoS. from rtgtll'C 1 

for the type of test fuel, by u.slng the value 

of dry stack gas Co. concentration. Xco:s. 

determined In accordance with section 3.1 of 

this appendix. 

4.2.4 Average sensible heat loss at fullload steady state operation. For a system 

employing an Integral draft diverter. determine the average sensible heat loss at full10:1d steady·state operation. :r....a..... expressed as a percent. from flgure 2 using the value 

of RyoS determined In 4.2.3. the type of test 

fuel, and ~T_, where 

~Ts.s=Ts.s.x-1I4 

where: 

Ts.&1=mea.sured stack gas temperature at 

!uIl·lo:td steady-state operation determined.1n accordance with section 3.1 or ~ appendlx.In degrees Fahrenheit. 

T ... =measured room temperature of con- ditioned space In which furnace or boiler 

is te5ted, determined In accordance with 

section 2.9 of this appendix. In degrees 

Fahrenheit. 

For systems not employing 2.n Integral 

draft di\"erler, determine the average sensible heat losa at full·load steady-state 'oper- ation. Ls..s..... expressed as a percent. 'from 

fjgure 2 using the value of Rr', determined 

In 4.2.2, the type of test fuel, and ATF.s3 

where: 

ATF..g=T, .. -T .... where: 

T,.u=flue gas temperature at. full-lead 

steady·state operation determined in ac- cordance with sectIon 3.1 of this appendJx, In degrees Fahrenheit. 

T.... as defined above. 

4.2.5 Steady state efficIency. Calculate 

the steady-state efficIency (excluding jacket loss), T/sa' expressed In percent and defined as 

'IlJs=100 - Lr..... - 4.u...l 

where: 

Lr.....=average latent heat loss 01 the test 

fuel determined In accordance with 

Table 3, In percent. 

!.s..u..l=as defined In 4.2.4 

4.2.6 Average ration of stack gas mass flow rate to flue gas mass flow rate at fullload steady·state operation. Determine the 

average ration of stack gas ma.s3 flow rate to 

flue gas mass flow rate at full-load steadystate operation. SIP. for the system number 

to be tested from table 1 or 2-

4.2.'1 Equ!\'alent fleld stack gas temperature at full·load steady-state operation. Calculate the equivalent fleld stack gas temFEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1971 
20160 

perature at full-load steady-state operation. 

Ta .... expressed in degrees Fahrenheit and 

defined as: . 

T 1 IT - T ] + T 

S,55- ~ F,55 RA RA, 

where: 

T,. ss as defined in 4.2.4. 

TRA as defined in 4.2.4. 

SIF as defined in 4.2.6. 

4.2.8 On-cycle time constant. Calculate 

the on-cycle time constant, 1'0 •• expressed in 

minutes and defined as: 

T' 

on 

where: 

- [T EjSS 

for furnaces: 

t,=0.5 minutes. 

t.=2.5 minutes. 

for boilers: 

t,=1.0 minute. 

t t 

-T (t ) 

F,on 2 

t.=5.5 minutes. . Tp.OD<t,)=flue gas temperature measured 

at time (t,) from start-up of the'system burner determined in accordance with 

section 3.3 of this appendix. in degrees 

Fahrenheit. 

Tp.o.<t.)=flue gas temperaturee.measured 

at time (t.) from start-up of the system 

burner determined in accordance with 

section 3.3 of this appendix. in degrees Fahrenheit. 

Tp. ss as defined in 4.2.4. 

4.2.9 Effective flue gas temperature difference at startuP. Calculate the effective 

flue gas temperature difference at start-up of the system burner. 8p.o.x. expressed in degrees Fahrenheit and defined as: 

e

F = [TF ,55 - TF,on (\ J 

,o,x, J 

where: 

T,.ss as defined in 4.2.4. 

T,. o.(t,) as defined in 4.2.8. 

t, as defined in 4.2.8. 

1'0. as defined in 4.2.8. 

4.2.10 Off-cycle time constant. Calculate 

the off-cycle time constant. "011'. eXllressed in 

minutes and defined as: 

T 

off 

In TF •OFF t3 - TF •OFF ("') J T (t ) - (T ('" ) 

F,OFF 4 F,OFF 

RULES AND REGULATIONS 

where: 

for furnaces: 

t.=1.5 minutes. . t.=9.0 minutes. 

for boilers: 

t.=3.75 minutes. 

t.=22.5 minutes. 

T,.o,,(t;.)=flue gas temperature measured 

at time <t.) after shut-down from steadystate operation of the System burner determined in accordance with section 3.2 • of this appendix. in degrees Fahrenheit. 

T,.o,,(t.)=flue gas temperature measured 

at time <t.) after shut-down from steadystate operation of the system burner determined in accordance with section 3.2 

of this appendix. in degrees Fahrenheit. 

T,.opp(co)=minimum flue gas temperature . determined in accordance with section 

3.2 of this appendix. in degrees Fahrenheit. 

4.2.11 Effective flue gas temperature difference at shut-down. Calculate the effective flue gas temperature difference at shutdown of the system burner. wP.o.x. expressed in degrees Fahrenheit and defined as: ., 

I/J =rT (t ) - T (",)1 e 

F,O.K L F.OFF 3 F,OFF J 

where: 

T,.orr<t;.) as defined in 4.2.10. 

T,.o,,(co) as defined in 4.2.10. 

t. as defined in 4.2.10. 1'o~' as defined in 4.2.10. 

t 

3 -toff 

4/2/12 Minimum flue gas temperature difference abovil room temperature. Calculate the minimum flue gas temperature difference above room temperature. ljIp.co.x. ex- pressed in degrees Fahrenheit and defined as: 

where: 

TF.O,,(co) as delined in 4.2.10. 

TRA as defined in 4.2.4 .. 4.2.13 Minimum stack gas temperature difference above room temperature. Calcu- . late the minimum stack gas temperature 

difference above room temperature. ljIs.co.x expressed in degrees Fahrenheit and defined as: . For systems numbered 1-4. and systems 5-

8 for which , • 

D : 

F 

W = (D) (W 

S,co,X F F,co,X 

(S/F) (D ) 

S 

For systems numbered 5-8 for which 

D : 

F 

where: 

Dp=off-cycle flue gas draft factor selccted 

from table 1 or. for units with power burners where Dr is measured. deler· 

mined in accordance with sectlon 4.4.2 

of this appendix. Ds=off-cycle stack gas draft factor selected from table 1 or. for units with power burners where Dr is measured. determined in accordance wIth sectlon 4.4.3 

of this appendix. 

SIF as defined in 4.2.6. 

ljIF.CO.x as definellin 4.2.12. 

4.2.14 Effective stack gas temperature 

difference at shut-down. Calculate the effective stack gas temperature difference nt 

shut-down.ljIs.o.x. expressed in degrees Fahr· 

enhelt and defined as: For systems numbered 1-4. and systems 6~ 

8 for which 

D : 

F 

W = (D ) ( 1/1 ) 

S,O,X F F,O,X 

(S/F) (D ) 

For systems 5-8 for which 

1/1 s.o.x = lJI F.O.X 

where: 

Dr as defined in 4.2.13. 

ljIr.o.x as defined in 4.2.1,1. 

SIF as defined in 4.2.6. 

Ds as defined in 4.2.13. T'ap.O.X as defined in 4.2.11. 

S 

- 4.2.15 CorrectIon factors for systems 0-

12. Calculate a correction factor which cor· rects for the use of outdoor air for combustion instead of air at room temperature. Ca. 

defined as; 

c 

s = 

(70-42) n 

SS 

1 + (T -T) 100 

F,SS RA 

fEDERAL REGISTE~, VOL 4:" NO. 91-WEDNESDAY, MAY 10,1978 
where: 

42=average outdoor temperature corre· sponding to 5,200 degree day location, in 

degrees fahrenheit. 

'lJss as defined in 4.2.5. 

TFoSS as defined in 4.2.4. 

'10 assumed average indoor air t.empera· 

ture. 

Tru. as defined in 4.2.4. 

The correction factor which corrects for 

the effect of outdoor air passing through the heat exchanger during the off·period, 

0' So is defined as; 

0'8=1.22 

4.2.16 Multiplication factor for sensible 

heat loss during burner on-cycle. Calculate a 

multiplication factor for sensible heat loss 

during burner on-cycle, Ks.en, defined as: 

K 

S,en 

100 C [1 + (R ) (A/F)] 

where: 

P _ T,F 

HBV 

A 

Cp=0.24 Btu per pound-degree Fahren· 

heit, specific heat of air. 

R,..F as defined in 4.2.2. 

A/F=st.oichiometric air/fuel ratio deter~ 

mined in accordance with Table 3. 

HHVA=average higher heating value of 

the test fuel determined in accordance 

with Table 3, in Btu's per pound. 

4.2.1'1 Multiplication factor for sensible 

heat loss during burner off-cycle. Calculate a multiplication factor for sensible heat loss 

during'burner off-cycle, Ks. 0'" defined as: For systems numbered 1-4: 

1.19 K (T - T + 530) (0 ) (K 

S,OFF F,SS FA F S,on 

0.56 

(T - T ) 

F,SS RA 

where: 

530=assumed aVerage indoor temperature in degrees Rankine. TFoSS as defined in 4.2.4. 

TRA as defined in 4.2.4, - Dr as defined in 4.2,13. 

Ks.on as defined in 4.2.16. 

For systems numbered 5-8: 

_ 1.19 K (T -T +530) (0 )(S/F)(K 

S,OFF S.SS RA 5 S.on 

(T - T +-70-42) 

S,SS RA 

where: 

Ts.ss as defined in 4.2.'1. 

Ds as defined in 4.2.13. TB.\ as defined in 4.2.4. 

S/F as defined in 4.2.6. 

0.56 

RULES AND REGULATIONS 

Ks.= as defined in 4.2.16. 

530 as defined above. 

42 as defined in 4.2.15. 

'10 as defined in 4.2.15. 

For systems numbered 9-12: 

I); ,OFP a 

1.19 

'1j, ,55 - Tp.\ + 5301 IF:S ,On' IDpl 

11j, ,55 - TpA + 10-421 

where: 

T roSS as defined in 4.2.4. 

Dr as defined in 4.2.13. 

TL\ as defined in 4.2.4. 

Ks.,..:l as defined In 4.2.16. 

530 as defined above. 

42 as defined in 4.2.15. 

'10 as defined in 4.2.15 

0.56 

4.2.18 MultiplIcation factor for infiltra· 

tlon loss during burner olI-cycle. Calculate a 

multiplication factor for inflltratlon loss 

during burner on-cycle. KLe::. defined as: For systems numbered 1-8: 

KIoe:I""C¢)'S/F)'K5.c.» 

where: 

4>=0.7. infiltration pnrnmeter. 

S/F as defined in 4.2.6. 

- KSo<:> as defined in 4.2.16. 

4.2.19 MultiplIcation factor lor infiltration 1065 during burner o!!-cycle. Calculate a 

multiplIcation factor for inflltraUon loss 

during burner o!!-cYcle Kr.cm defined as: For systems numbered 1-8: 

1.19 It a IT - T + 5301 lit I 10 I 

I.OFF S,SS F .. \ U.56 I.on G 

IT - T + 10-421 

S,SS PA 

where: 

Ts.ss as defined in 4.2.7. 

530 as defined in 4.2.17. 

42 as defined In 4.2.15. 

KIoe:> as defined In 4.2.18. 

Ds as defined in 4.2.13. 

'10 as defined in 4.2.15. 

TI!.\ as defined in 4.2.4. 

4.2,20 Ratio of average burner on·time 

per cycle to on-cycle time constant. Calcu· 

late the ratio of average burner on·tlme per 

cycle to on-cycle time constant;. tdT'= defined as: 

where: 

For furnaces: 

t 

.....2!!. 

T 

on 

to,,=3.87 minutes. the average burner on· 

time per cycle. 

To as defined in 4.2.8.' 

20161 

For boilers: 

t",,<=9.68 minute~ the average burner ontime per cycle. 

T'= as defined In 4.2.8. 

4.2.21 Ratio of average burner off·time 

per cycle to o!!-cycle time constant. Calculate the ratio of average burner off·time per 

cycle to o!!-cycle time constant. td!/T'_ defined as: 

where: 

For furnaces: 

t 

off 

T 

off 

tot:!",,13.3 minutes. the average burner offtime per cycle. 

T'c!f as defined in 4.2.10. 

For boilers: ~=33.26 minutes. the average burner offtime per cycle. 

T'ot:!=as defined in 4.2.10. 

4.2.22 Effective flue gas temperature difference at burner start·uP. corrected for 

burner cycling effect. Calculate the effective flue gas temperature difference at 

burner start·up, cQrrected for burner cycling 

effect, 8r.c. expressed in degrees Fahrenheit 

and defined as: For systems 1-8: 

8r.o=CCr.a)C8r.o.x) 

For !j'stems 9-12: 

8r.o=<Cr.aHC.)(Or.o.x) 

where: 

where: 

BrJ:!.X as defined in 4.2.9 

Cs as defined in 4.2.15 eF.O.x as defined in 4.2.11 ~/TCi" as defined in 4.2.21 

tdTca as defined in 4.2.20 

Tr..s:s as defined in 4.2.4 

Tr.c;rr.1 ) as defined in 4.2.10 

4.2.23 Effective nue gas temperature difference at burner sbut-down, corrected for 

burner cycling effect. Calculate the effective flue gas tempa-ature difference at 

burner sbut-down. corrected for burner cycling effect. Vr.o. 

For nj':item:: 1-8: 

Vr.o=CCt.or)'yv.o.x) 

For sy::;tems 9-12: 

V,.o=CCt.o11')(Cs')(t;!v.o.x) 

where: 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 
20~62 

where: 

If!F.O.X as defined In 4.2.11. 

CD as deflnedJn 4.2.15. 

" OF.O.X as defined In 4.2.9. 

toFF/TOF1' as defined In 4:2.21. 

tonho• as defined In 4.2.20. 

TF•53 as defined In 4.2.4. 

T V•OFF, (00) as defined In 4.2.10. 

Coo = I, for units with continuously burn- , Ing pilot lights, 0.90 for units with intermittent ignition devices or cycling pilots. 4.2.24 Effective mInlmum flue gas temperature difference above room temperature, corrected for burner Cycling effect. 

Calculate the effective mlnfmum flue gas 

temperature difference above room temperature, !/IF. 00 , corrected for burner cycling effect, expressed In degrees Fahrenheit and 

defined as: For systems numbered 1-8: 

!/IF. 00 =If!F.OO.X 

For systems numbered 9-12: 

!/IF. 00 =(CS')(!/IF.OO.X) 

where: 

C,{ as defined In 4.2.15. 

If!F.OO. X as defined In 4.2.12. 

4.2.25 Effective stack gas temperature difference at burner shut-down, corrected 

for burner cycling effect. Calculate the effective stack as temperature difference at 

burner shut-down, corrected for burner cy- cling effect, If!s.o. expressed In degrees Fahrenheit and defined as: For systems numbered 1-8: 

o/s.o=(!/Is.o.X)(CIooII) 

Where: 

CI•olI as defined In 4.2.23. 

If!s.o.x as defined In 4.2.14. 

4.2.26 Off-cycle' sensible heat loss integration factors. For systems numbered- 1-4, 

determine off-cycle sensible heat loss integration factors, F3 and F4, from Figures 3 

and 4, respectively, using values of If!F.O defined In section 4.2.23, and tOil/Toil defined In 

section 4.2.21. 

For systems numbered 5-8 determine offcycle sensible heat loss Integration factors, 

F5 and F6, from Figures 5 and 6, respective- ly, using values of I/Is.o defined In section 

4.2.25, and and toll/Toll defined In section 

4.2.21. 

For systems numbered 9-12'determlne the 

off-cycle sensible heat loss Integration factors, F5 and F6, from Figures 5 and 6, re- spectively, using values of I/IF.O defined In, 

section 4.2.23 and toll/Toll defined In section 

4.2.21. 

4.2.27 Off-cycle infiltration heat loss integration factors. For systems numbered 1-

8, determine off-cycle Infiltration heat loss 

Integration factors, F7 and F8, from Fjgures 

'1 and 8, respectively, using values of If! •• o defined In section 4.2.25, and and tOil/Toil defined In section 4.2.21. 

4.2.28 On-cycle sensible heat loss. Calculate the on-cycle sensible heat loss of the 

system, La.OIl. expressed In percent and defined as: For systems numbered 1-8: 

(K ) ( e 

S,ON F,O 

- (t 

RULES AND REGULATIONS 

For Systems numbered 9-12: 

L (C ) (L ) - (K ) 

S,ON S S,SS,A S,ON 

- (t 

on -T--

X( e 

F,O 

where: 

( 1 

t IT on on 

Cs as defined in 4.2.15. 

L S.SS•A as defined in 4.2.4. 

K s.oN as defined in 4.2.16. 

8M as defined in 4.2.22. 

to.h .. as defined In 4.2.20. 

on 

(l-e 

4.2.29 Off-cycle sensible heat loss. Calculate the off-cycle sensible heat loss of the 

system. LS.OFF• el>.-pressed in percent and defined as: For systems numbered 1-4: 

L 

S,OFF 

(K ) (t ) 

SJOFF off -t--

on 

X[(F3)+(~ )(F4)] 

F,co 

For Systems numbered 5-8: 

L = (K ) (t ) 

. S,OFF S,OFF off, -t--

on 

XL r (FS) + (1jI ) (F6) J 

s,co ,x . 

. For systems numbered 9-12: 

L (K ) (t ) 

_ S,OFF S,OFF off -t--

on 

)( reFS) + (1jI ) (F6)] r FICO 

where: 

K S•OFF as defined In 4.2,1'1. 

tOil as defined in 4.2.21. 

to. as defined in 4.2.20. 

F3. F4, F5. and F6 as defined in 4.2.26. • If!F.OO as defined in 4.2.24. 1/Is.00.x as defined in 4.2.13. 

4.2.30 On·cycle Infutration heat loss. Cal· 

culate the on-cycle infiltration heat loss of 

the system, L 1•ON, expressed in percent and 

defined as: For systems numbered 1-8: 

LI.ON=KI.ON('10-42). 

where: 

K I •ON as defined in 4.2.18. 

70 as defined in 4.2.15. 

42 as defined in 4.2.15. 

For systems numbered 9-12: 

Lt.ON=O 

4.2.31 Off-cycle infiltration heat loss. 

Calculate the off·cycle infiltration heat loss 

of the system Lt.OFF, expressed in percent and defined as: For systems numbered 1-8: 

L 

I,OFF 

K 

I,OFF 

(70-42) (t ) 

off 

-t--

Qn 

X ~F7) + (1jI ) (F8) J L' S,.",X 

where: 

K I •OFF as defined in 4.2.19. 

70 as defined in 4.2.15. 

42 as defined in 4.2.15. 

tou as defined in 4.2.21. 

t.. as defined In 4.2.20. 

F7, F8 as defined in 4.2.27. 

1/Iscoy as defined in 4.2.13. 

For systems numbered 9-12: 

Lt.OFF=O 

4.2.32 Part-load fuel utilization off/clen' 

cy. Calculate the part-load fuel utilization 

efficiency, expressed in percent and defined as: 

for indoor units -

n c 100 ~ L -[. :1~]" ,] u L.A on P o£f 

Q 

in 

XL +L +L +10 " [ S,ON S,OFF l,ON l,OFi' ] 

for outdoor units -

., '" 100-L - C u L,A j 

(L ) 

:I 

X[L + 10 ] S,ON S,OFF 

FEDERAL REGISTER, VOL. 43, NO. 91-WEDNESDAY, MAY 10, 1978 
where: 

CJ=3.3 for furnaces intended to be in· 

stalled outdoors. ~ 

4.7 for boilers intended to be installed outdoors. 

Q,,=Pi1ot flame fuel input rate determined 

in accordance with section 3.2 of this 

Appendix, in Btu's per hour. 

Q",=Full·load input rate (including pilot 

flame fuel input rate) determined in ac· 

cordance with section,3.l of this Appen· 

dix, in Btu's per hour. 

~=Jacket loss determined in accordance 

with section 3.4 of this Appendix, in per· 

cent. 

Lz.... as defined jn 4.2.5. 

t,.,. as defined in 4.2.20. 

t.u as defined in 4.2.21. 

Ls.ON as defined in 4.2.28. 

Ls.oFF as defined in 4.2.29. 

L,.ON as defined in 4.2.30. 

!.z.OFF as defined in 4.2.31 

4.2.33 Annual fuel utilization efficiency. 

Calculate the annual fuel utilization effi· 

ciency. EFFYAo defined as: 

('I ) ('I) (5200) 

5S u 

(, ) (5200) + (2.5) (ll I (Q) ci.1) (4600) 

~ u P 

(Ol 

where: 

5.200=The average number of annual 

heating degree-days for the United 

States. 

4,600=The average D~ber of nonheatlng season hours per year that the energy to 

the pilot light is assumed wasted. 

1.7=Average furnace tizing factor. 

nss=As defined in 4.2.t'. 

nu=As defined in 4.2.3!,!. 

Q,,=As defined in 4.2.32. 

Q",=As defined in 4.2.32. 

4.3 Additional requirements for fUTTUlCe8 

utilizing a stack (or flue) -damper. Calculate 

the stack (or flue) dampet" effectiveness. Do. 

defined as: 

D = o 

where: 

A,,'=ADcos(O). 

5" 

5 + 

As=Cress sectional area of the stack determi,ned in accordance With section 3.5 

of tb.!s appendix, in sqU8.I'f}oinches. 

A,,=Net area of the damper plate deter· 

mineQ in accordance with section 3.5 of 

this appendix. in square inches. 

RULES AND REGULATIONS 

fi=The angle the damper plate makes. 

when closed, with a plane perpendIcular 

to the axis of the stack, determined in 

accordance with secUon 3.5 of this appendiX. 

4.4 Additional n:qufremen13 for fuma~ 

utilizing 'indoor afr faT combU3tfon and 

draft control. For units obtaining combustion air and draft control air from inside the 

residence, determine the appropriate factor 

describing the raUo of on-cycle stack flow to 

on-cycle ftue flow (SIP). the raUo of off· 

cycle flue flow to on-cycle flue flow at Iden· 

tical temperatures (D,), and the raUo of off· 

cycle stack flow to on-cycle stack flow at 

identical temperatures (Ds) from Table 1. 

4.4.1 Optional procedure for determina· 

tion 0/ Dp for furnaces or boilers employing a power burner. Calculate the ratio (D,) of 

the rate of flue gas mass flow througil the 

furnace or boiler during the off :period, 

mF.OJ"F (Tr.ts). to the rate of flue gas mass flow during the on·perIod, m,.ss (Tr .. >, and 

defined as: 

= ~,OFF (TF,SS) 

~,SS (TF,SS) 

, 

For gas fueled units or oU fueled units for 

which no draft is maintained during the 

steady·state or cool down test: 

F-or oil fueled units tested with an Im· 

posed draft as described in section 3.6: 

where: 

Tr.ss=As defined in 4.2.4. 

T·,.oi?=Flue sns temperature during the 

off·period measured in accordance with 

section 3.6 of this appendL"t. jn degrees 

fahrenheit. 

42 as defined in 4.2.15. 

460=Collverslon fnctor to convert degrees fahrenheit to degrees rankine. 

Tu as defined in 4.2.4. 

* . Ih (T )= (lOO-C ) V P 

F,OFF F,OFF T T F 

C 

T 

20163 

where: 

VT=Flow rate of tracer gas through the 

furnace measured in accordance with 

secUon 3.6 of this appendix. in cubic feet 

per minute. ~=Concentratlon by volume of tracer gas p~ent in the nue gas sample measured 

in accordance with section 3.6 of this appendlx, in :percent. p,=The density the nue gas woulCl have at 

the temperature TT in Ib :per cu ft. It 

may be approximated by the eqnation: 

P F-'" 

where: 

1.32Sf.. PB ) 

\T + 460 

TT=Temperature of tracer gas entering 

flow meter measured in accordance with 

section 3.6 of this appendix. in degrees 

fahrenheIt. 

P.cBarometric pressure measured in ac- cordance with secUon 3.6 of this appendlx, In inches of mercury. 

where: 

Rr". as defined in 4.2.2.. 

AlP as defined in 4.2.16. ~ as defined in 4.2.32. 

BHV A as defined in 4.2.16. 

60=>Convers1on factor to convert hours to 

minutes. 

4.4.2 Optional procedure for determination of off-cycle draft factor for flue gas 

flow for furnaces or bollers employing a power burner. Calculate the o!!-cycle draft 

factor for flue gas now. Dr. defined as: 

for sYStems numbered 2. 4, 6. 8 or 10: 

o,=D,. 

for system. number 12: o,=<Dr}(D.}. 

where: 

D, as defined in 4.4.1. 

Do as defined in 4.3. 

4.4.3 Optional procedure for determination of off-cycle draft factor for stack gas 

flow for ftml3ces or bollers employing a power burner. Calculate the of!-cycle draft 

factor for stack gas now. Ds, defined as: 

for system number 2: Ds=l.O. 

for system number 4: D 3 c{O.79+l>p>ll.4. 

for system. number 8: D.t=D.,.. 

For system number 8: 

I - I 

iSln 

if D ,. 1 

o (s.!n 

FEDElAL REGISTER. VOL 43, NO. 9t-WEDNESDAY, MAY 10, 1971 
20164 

where: 

D1' as defined in 4.4.1. 

Do as defined in 4.3. 

4.5 Additional. Requirements . for Fur- naces Utilizing a Direct Vent System. For 

furnaces utilizing a dir~t vent system or Intended for outdoor installation. determine 

the appropriate S/F factor and DF factor 

from Table 2. If a unit is equipped with a • power burner. the optionBl procedure described in section 4.4.2 of this section may 

be used to calculate DF using the value of D1' 

determined in section 4.4.1 of this section. 

RULES ~~ND REGULATIONS 

t-=Blower delay time determined in ac- cordance with section 3.3.1 of this appendix. in minutes. 

QIn as defined in 4.2.32. 

Q1' as defined in 4.2.32. 

'I).as defined in 4.2.32. 

(2)=Ratio of the average length of a heatIng season in hours to the average heating load hours. 

100.000=Factor that accounts for percent andKBtu. 

4.8 Average Annual Fuel Energy Consumption for Gas or Oil Fueled Furnaces or Boilers. Calculate the average annual fuel 

energy consumption for gas or oil fueled 4.6 Additional Requirements for Fur- naces Which Modulate or VaTY Fuel Input 

Without ControUing Excess Comoustion Air. 

Test a furnace -which IS equipped with a mechanism for reducing the rate of fuel 

input. but does not provide a means for con- trolling excess combustion air. at its maxi- mum firing rate in accordance with test procedures in section 3. Use these test results to 

calculate a seasonal efficiency and an annual operating cost based upon a single 

fixed fuel input rate. 

- furnaces or boilers. Er. expressed in Btu's 

per year. and defined as: 

4.7 National Average Number of Burner 

Operating Hours. Calculate the average 

number of burner operating hours. BOH. 

defined as: BOH=(A)CC) (2.080) (average design heatIng requirement)-B (2.080). 

where: 

2.080=Natlonal average annual heating load hours (average design heating re- qUirement) is expressed In KBtu/hr and 

is obtained from Table 4 using the 

proper value of Q..I' 

Qoul=('1) .. /100) (QIn) rounded off to the 

nearest 1.000 Btu/hr for units intended 

for installation in a heated space and 

Q..1=QIn[('I)..I100)-(3.3) (LJ/100)] rounded off to the nearest 1.000 Btu/hr for 

units intended for installation outdoors or in an unheated space. 

e .. as defined in 4.2.5. 

Qm flS defined in 4.2.32. 

A = 100,000 

(341, 300) {PE + y Bl:) + (Q-in - Op) I U 

(2) (O~) (11) (A) 

100,000 

. C=0.77. adjustment factor which serves to 

adjust the calculated design heating re- quirement and heating load hours to the - actual heating load experienced by a heating system. 

PE=Power burner electrical energy input 

rate at full-load steady-state operation 

determined in accordance with section 

3.1 of this appendix. In kilowatts. 

BE=Circulatlng-air blower (or circulatlngwater pump) electrical energy input rate 

at full-load steady-state operation determined in accordance with section 3.1 of 

this appendix. in kilowatts. 

y=1+«t+-t-)/3.87) for furnaces. 1.00 for 

boilers and 1.00 for furnaces employing' a single motor to drive a power burner· 

and air circulating fan or blower. the 

ratio of average blower or pump on time 

to average burner on time. 

where: 

t+=Blower delay time determined in a.c- cordance with section 3.2.1 of this appendix. in minutes 

E'p=(Qm-Q1')(BOH)+(8760)CQp). 

where: 

Qm as defined in 4.2.32. 

Qp as defined In 4.2.32. 

BOH as defined in 4.7. 

8.760=Tota! number of hours in a year. 

4.9 Average Annual AuxiliaTY Electrical 

Energy- Consumption for G<zs or Oil Fueled 

Furnaces or Boilers. Calculate the average annual auxiliary electrical energy consump- tion. EAE• expressed in kilowatt-hours per 

year and defined as: EAE=(PE+v BI:)(BOH) 

where: 

PE as defined in 4.7. 

BE as definec1in 4.7. 

y as defined in 4.6. 

BOH as defined in 4.7. 

4.10 Average Annual Electric Energy 

Consumption for Electric Furnaces or Boil- ers. Calculate the average annual electric 

energy consumption for electric furnaces or bollers. &:. expressed in kilowatt-hours per 

year. and defined as: -

(100) (2080) Idcsiqn hCdtlnq require:::cntl 

£C·------~C~F·~FY~-r(jr.~4i~3r)--------­ II-C 

where: 

tC) 

100=Conversion factor to convert percent - to decimal fraction 

(design heating requirement) is expressed in 

KBtu/hr and is obtained from Table 4 with 

Q.ul set equal to the quantity (Em) (3.413) 

rounded off to the nearest 1000 Btu's per hour for units intended for installation in a heated space and ' (Em) (3.413) 

«l00-(3.3)(L.!»/(l00) for units intended for 

installation out-of-doors or in an unheated 

space. 

where: 

EID=electric power input in watts meas- ured in accordance with sections 3.1.3 

and 3.1.4 of this Appendix. 

2.080 as defined in 4.7. EFFYA- E as defined in 4.1. . 3.413 conversion factor corresponding to 1 

watt=3.413 Btu/hr. 

L.! as defined in 3.4. 

C as defined In 4.7. 

_4.11 Average Number of Burner Opening 

Hours in Different Geographic Regions of 

the United States and in Buildings with Different Design Heating Requirements. CRIculate the average number of burner operat- ing hours by geographic· region of the 

United States. BOHa. defined as: BOHa=(C)(A)CHLH»Ctypical design heating requkement)-BCHLH) 

where: 

HLR=Heating load hours for n specUlo • geographic region determined in Rccord· ance with the heating load hour mop in 

Figure 9. 

B = (2) (A) (Op) (n u ) , 

100,000 

where: 

(2) as defined in 4.7. 

A as defined in 4.7. 

Qp as defined in 4.2.32. 

'I). as defined in 4.2.32. 

100.000 as defined in 4.7. 

C as defined in 4.7. 

Typical design heating requirement lIS 

given in Ta.ble 4 for the npproprlote valllo ot 

QOtrr. where Qoul is defined in 4.7. 

4.12 Average annual fueZ energy con- 8umption for gas or oil fueled furnaces or boilers Zocated in d:lJferent geographio re· gions of the United States and in bufldings 

with different design heating requirements. 

Calculate the average annual fuel enorgy consumption for a specUla geographio region and for a specific typical design heotIng requirement. E,.a. expressed in Btu's por 

year. and defined as: 

E,.a=(Qm-Qp)+(8760) (Qp) 

where: 

Qm as defined in 4.2.32. 

Qp as defined in 4.2.32. . BOHa as defined in 4.11. 

8760 as defined in 4.8. 

4.13 Average annual auxilfarv electrical 

energy consumption for gas or oil fueled fur- naces or boilers in different geographio reo gions of the United States and in bufldings 

with different design heating requirements. 

Calculate the average annual auxiliarY olcctrical energy consumption for a specifio geo· graphic region and 'for a speciflo typical design heating requirement. E.u:.R expressed in kilowatt-hours per year and defined as: 

EAR.a=(PE+y BE) (BOHR) 

where: . PE as defined in 4.7. 

BE as defined in 4.7. 

y as defined in 4.0. 

BOHR as defined in 4.11. 

4.14 Average annual electrio energ1l .con· 8umption for electrical furnaces or boflers 

in different geographic regiom of the United 

States and in buildings with different design 

heating requirements. Calculate tho averago annual electric energy consumption by geo· graphic region of the United States. E1 •n• ex· pressed in kilowatt-hours per year, and do· 

fined as: 

E • a (100) (C) (ULI!) (d~si9n h~.tin? r~q"ir~~~nll 

E.R (EFFYA_

E

) (3.4131 

where: 

100 as defined in 4.10. 

HLH as defined in 4.11. 

(design heating requirement) as dOflned in 

4.10. 

EFFYA-g as defined in 4.1. 

3.413 as defined in 4.10. 

C as defined in 4.7. 

FEDERAl REGISTER, VOL. 43, NO. 91-WEDNESDAY, MAY 10, 1978 
I'ype of. Burner 

-

Mllospheric 

Power * 

RULES AND REGULATIONS 

where: 

100 as defined in 4.10. 

HLH as defined in 4.11. 

(design heating requirement) as defined in 

4.10. 

EF'PY1o- E as defined in 4.L 

3.413 as defined in 4.10. 

C as defined in 4..7. 

'n:lble 1 

Factors Describing Air F10il Rllt'l for G-lS and Oil-Fired Furnaces or Boilers Utilizing Indoor Air for Qrbustion and Draft Control 

Units Without a Stack DaIrper L'nits ~:ith a Stack DaI!per 

but with and 

Draft lbod or Droft lIoed or 

20165 

Draft Oiverter Bararetric Draft Control Droft oiverter Bararetric Draft Centrol 

Systan ;'t 

1 

2 

0 D sys- 0 0 Sys- D D Sys- D D 

S!F F 5 tan t S!F F 5 ten t S!F F 5 ter.l t S!F F 5 

2.4 1.0 1.0 3 1.4 1.0 1.0 5 2.4 1.0 D 7 1.4 1.0 D 

0 0 

2.4 0.4 1.0 4 1.4 0.4 0.85 6 2.4 0.4 D 8 1.4 0.4 (0 ) (0') 

where 

0' 

p 

0.4,if D ~ l/(S/F) 

o 

0 

0.4 + (0.85 - (0.4) (D» (0 - ~S!F~ o 0 , if D > l/(S/F) 

o (l - iIti/F» 0 o 

'rna above factors \·:&c dev~loPCd b'J the !:3tion::1l. l!U.reau of Sl:ar.!:brds 

antl are based u[r.n information in the public litcru.turc, luOOmtoty 

and co:rqmtcr si.mulation studies conducted 41t t!IlS, and Inlxlmtory 

and field data obtained b'j sc,;-cral rcsZJrCh ficrs ur.der conttuct" 

to NBS and DOE. 

*A poI\'er burner rray incorporate a cevice on its air inlet .... hlch osens 

the air- L-u.ct \-'hcr. the iift'l.i.mcc .is in o!=ClUt.lon lll'.d Clcr...es the aU;' 

inlet "11en the applia.noc is in the st:.J.ridb".l condition. 

Table 2 

Factors Describing Air Fla.·, Rates fo:: Gas or Oil-Fired Em:n~ccs/Boilers 

Intended for Installation Out-of-D:ors or Intended for In:!oor Installation 

But Equiwcd \'lith a Direct Ve:nt Systc;n 

Units \~ithout A Stack 

0 p 

Type of Burner or Flue D.:lmpcr Units t-;ith a Flue D3.~ 'l\'Pe of Draft 'S!F 

Atnosphere 

Power 

Systani 

9 

10 

D D 

F - Systani F lb1e 

1.00 11 D barcr:letric 

0 da"J'iler 

0.40 12 0.40 x D draft diverter 

0 

The above factors \\'Cre developed. by the NatiOftdl B>.lrcau 

of Standards and are based upon information in the public 

literature, laboratory and CCliIl'Uter sin:ulation studies 

conducted at NBS, and laboratory <md field data obtained 

by several research firms under contract to tlES and OOE. 

FEDERAL REGISTfI, VOL 43, NO. 91-WE9NESDAY, MAY 10, 1971 

1 

1.4 

2.4 
20166 RULE!; AND REGULATIONS 

Table 3 

Values of Higher Heating Value (HHV ), Stoichiometric Air/Fuel 

A 

Ratio (A/F), and Latent Heat Loss (L ) for Typical Fuels 

L,A 

HHV (Btu/1b) L (%) 

Fuels A A/F(--) L,A 

No. 1 Oil 19,8"00 14.56 6.55 

No. 2 Oil 19,500 14.49 6.50 

I 

Natural Gas 20,120 14.45 9.55 

Manufactured Gas 18,500 11.81 10.14 

Propane 21,500 15.58 7.99 

Butane' 20,890 15.36 7.79 

Table 4 

Average and Typical Design Heating Requirements 

for Furnaces and Boilers with Different 

Output Capac{ties 

Furnace or Boiler Output 

Capacity, QOUT (Btu/hr) 

26,000 - 34,000 

35,000 - 42,000 

43,000 - 5'1,0.00 

52,000 - 59',000 

.60,000 - 76,000 

77,000 93,000 

94,000 - 110,000 

111,000 - 127,000 

128,000 - 144,000 

i\verage Design 

Heating Requirements 

(KBtu/hr) 

20 

25 

30 

35 

4Q 

50 

60 

70 ' 

80 

Typical Design 

Heating Requirements 

(KBtu/hr) 

15,20 

20, 25, 30 

25, 30, 35 

30, 35, 40, 45 

35, 40, 45, 50 

40, 45, 50, 60 

50, 60, 70, 80 

60, 70, 80, 90 

70, 80, 90, 100 

'145,000 - 161,000 90 80, 90, 100, 110, 120 

162,000 - 178,000 100 90, 100, 110, 120, 130 

179,000 1~5iOOO '110 .100, 110, 120, 130, 140 

over 196,000 130 120, 130, 14Q; 150, 160 

FEDERAL REGISTER, VOL 43, NO. 91"':WEDNESDAY, MAY 10, 1978 
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I!e.::ting IDad Hours (HLH) for em united States and Territories 

This tnap is reasonabtj aaxlrata foc most parts of the United States but is necessari¥ high~ . 

~enera!iled. and coosequentJy not too accurate in mountainous regiOC'l$. particuia.~ in the Rackies. 

lil<lska - 3500 HL!l 

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Territories 

fWElAl REGlSTElt, vot. 43, NO. 91-WE>NfSDAY. MAY 10, 1918 

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\lORK SHEE:r FOR Fl!RNACE/BOILER SYSTEH. 

Measured Quantities and Systec Characteristic Constants 

. 

1 2 3 4 5 6 7 8 

SYS6 TFUEL HHV QI~ Qp FE BE XCOZ.S 

(-) (-) Btu/lb. Btu hr. Btul.1r. kW kW % 

. 9 " 10 11 12 13 14 15 16 

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17 18 19 20 21 22 

TRA LJ S/F D D Y 

(!) (~) (-) F r. (-) 

Derived System Parameters 

23 24 25 26 27 28 29 30 

PF HHVA A/F LL,A CJ ~jF L S,SS,A 1155 (-) Btu/lb. (-) ~ (-) '- 1: 

. 

31 32 33 34 35 36 37 38 

TS•SS TON e TOFF ;p 'PF, ... ,X ~S ... X ~ F,O,X F,O,X S.O.X 

F minutes F minutes F F 'F' F 

.j~ 40 41 42 43 

Cs !<s.ON ~tOFF KrtON Kr,OFF 

(-) (%)/F (%)/R 0.37 (r.) /F (r.)/RO.37 

Calculation of System Losses and Annual Fuel Utilization Efficiency 

- -44 45 46 47 48 49 50 S1 

"rOA ! t tOFF ON tON/TON tOFF/TOFF BF,o tlIF, 0 li'F,OJ F· minutes minutes (-) (-) F F F 

52 53 54 55 56 57 58 59 

1l'S,O $S,CD F3 F4 FS F6 F7 F8 

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60 61 62 63 64 65 66 67 

L S,ON LS,OFF LI,ON LI,OFF nu DD HR EFFYA 

% % % % % eF-days hC'urs r. 

-

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1971 
20182 

APPENDIX O-UNIFORM TEST METHOD FOR 

MEAsURING THE EliERGY CONSUMPTION OF 

VENTED HOME HEATING EQUIPMENT 

1.0 Definttions. 

1.1 "Steady-state conditions for vented 

home heating equipment" means equlllbri- um conditions as indicated by temperature variations of not more than 5° F (2.8C) in 

the flue gas temperature for units equipped with draft hoods, barometric draft regulators or direct vent systems, in three succes- sive readings taken 15 minutes apart or not more than 3° F (.17C) in the stack gas temperature for units equipped w).th integral draft diverters in three successive Teadings taken 15 minutes apart. . 1.2 "Flue gases" means reaction products resulting from the combustion of a fuel 

with the oxygen of the air, including the 

inerts and any excess air. 

1.3 "Excess air" means air which passes through the combustion chamber and the 

vented heater flues in excess of that which 

is theoretically required for complete com- bustion. 

1.4 "Flue" means a conduit between the 

flue outlet of a vented heater and the,integral draft diverter, draft hood, barometric 

damper or vent terminal through which the 

flue gases pass prior to the point of draft 

relief. 

1.5 "Heater outlet" means the opening provided in a vented heater for the exhaust 

of the flue gases from the combustion 

chamber. 

1.6 "Flue losses" means the sum of sensible and latent heat losses above room temperature of the flue gases leaving a ventea 

heater. 

1.'l "Stack" means the portion of the ex- haust system downstream of the integral draft diverter, draft hood or barometric 

draft regulator. 1.8 "Stack gases" means the flue gases combined with dilution air that enters at 

the integral draft diverter, draft hood or barometric draft regulator. 1.9 "Bar6metric draft regulator or barometric damper" means a mechanical device 

designed to maintain a constant draft in a vented heater. 

1.10 "Air shutter" means an adjustable device for varying the size of the primary air inlet(s) to the combustion chamber 

power burner. 

1.11 "Power burner" means a vented 

heater burner which supplies air for com- bustion at a pressure exceeding atmospheric 

pressure, or a burner which depends on the 

draft induced by a fan incorporated in the 

furnace for proper operation. 

1.12 "Vent limiter" means a device which 

limits the flow of air from the atmospheric diaphragm chamber of a gas pressure regu- lator to the atmosphere. A vent limiter may be a limiting orifice or other limiting device. 

1.13 "Vent/air intake terminal" means a device which is located on the outside of a building and is connected to a vented heater 

by a system of conduits. It is composed of an air intake terminal through which the 

air for combustion is taken from the outside 

atmosphere, and a vent terminal from 

which flue gases are discharged. 1.14 "Ipduced draft" means a method of 

drawing air into the combustion chamber by 

mechanical means. . 1.15 '''Plenum'' means an air compartment, that is. attached to, or is an integral 

part of, a vented heater and which is designed to either distribute the heated air 

after it leaves the heat exchanger in the case of a supply plenum, or in the case of a 

RULES AND REGULATIONS 

return plenum, collects the air which enters 

the return inlet. 

1.16 "Heat input" (QIn) ,means the rate of 

energy supplied in a fuel to a vented heater, 

operating under'steady state conditions, ex- pressed in Btu's per hour. It includes any input energy to the pllot light and is obtained by multiplying the measured rate of 

fuel consumption by the measured higher heating value of the fuel. 

1.17 "Higher heating value" (HHV) means the heat produced per unit of fuel 

when complete combustion takes place at 

constant pressw'e and the products of com- bustion are cooled to the initial temperature of the fuel anel air and when the water 

vapor formed during combustion is con- densed. The higher heating value is usually expressed in Btu's per pound, Btu's per cubic foot for gaseous fuel, or Btu's per gallon for liquid fuel. 

1.18 "Integral draft diverter" means a device which is an integral part of a vented 

heater, designed to (1) provide for the ex- haust of the products of combustion in the . " event of no draft, back draft, or stoppage beyond the draft diverter, . (2) prevent a back draft from entering the vented veater, 

(3) neutralize the stack action of the chimney or gas vent upon the operation of the 

vented heater. 

11.19 "Draft hood" means a device which 

performs the same function as an integral draft diverter, but is not an integral part of 

the vented heater, and is connected to the 

vented heater by a short length of flue pipe. 1.20 "Vent pipe" means the passages and 

'conduits in a direct vent system through which gases pass from the combustion 

chamber to the outdoor air. • 1.21 "Inflltration parameter" means that 

portion of unconditioned outside air drawn 

into ,the heated space as a consequence of 

loss of conditioned air through the exhaust 

system of a vented heater. 

1.22 ,"Vaporizing type oll burner" means a device with an oll vaporizing bowl or other 

receptacle designed to operate by vaporizing 

liquid fuel oll by the heat of combustion, 

and mlxing the vaporized fuel with air. . 1.23 "Air tube" means a tube which car- ries combustion air from the burner fan to 

the burner nozzle for combustion. 

1.24 "Stack damper" is a device installed 

downstream of the integral draft diverter, 

dr8.ft hood, or barometric draft regulator, designed to· open the venting system when 

the appliance is in operation and to close off 

the venting system when the appliance is in 

the standby condition. 

1.25 "Flue damper" is a device installed 

between the furnace and the integral draft 

-dlverter. draft hood, barometric draft regu- lator or, vent terminal whiOh is not' 

equipped with a draft control device, designed to open the venting system when the 

appliance is in operation and to close the 

venting system when the appliance is in a standby condition. 

1.26 "Heating capacity" (Qou\) means the 

rate of useful heat output 'from a vented 

heater, operatlDg under steady state conditions, expressed in Btu's per hour. For room and wall heaten;, it is obtained by multiply- ing the "heat input" (QIn) by the steady 

state efficiency (n..) divided by 100. For 

floor furnaces, it is obtained by multiplying (A) the "heat lDput" (QIn) by (B) the steady 

state efficiency divided by 100, minus the 

quantity (3.3) (~).divided by 100, where ~ is 

the jacket loss as determined in 3.4 of this . appendix. 

2.0 Testing conditions. 

2.1 Installation of test unit. 

2.1.1 Vented wall furnaces (including direct vent systems). Install gas fueled 

vented wall furnaces for test as specUied in 

Sections 2.1.3 and 2.1.4 of ANSI Z21.49-1975. 

Install gas fueled wall furnaces with direct 

vent systems for test as described in 2.1.3 

and 2.1.4 of ANSI Z21.44-1973. Install oU 

fueled vented wall furnaces as specified in 

UL-730-1974, Section 33. Install oll fueled 

vented wall furnaces with direct vent sys· 

tems as specified in UL-730-1974, section 34. 

2.1.2 Vented floor furnaces. Instnll 

vented floor furnaces for test 'as specified in 

sections 35.1 through 35.5 of UL standard 

729-1976. 

2.1.3 Vented room heaters. Install in ac- {:ordance with manufacturer's instructions. 

2.2 Flue and stack requirements. 2.2.1 Gas fueled vented home heating equipment' employing integral draft di· 

verters and draft hoods (excludiDg direct 

vent system). Attach to, and vertically above the outlet of gas fueled vented home 

heating equipment employing draft dl· 

verters or draft hoods with verticnlly dis· 

charging outlets, a five (5) foot long test 

stack having a cross sectional area the srune size as the draft diverter outlet. Cover the 

test stack with insulation having an R value 

of not less than 7 ('F-BR-Ft'/Btu) and an outer layer of alwniDum foll. 

Attach to the outlet of vented heaters 

having a horizontally discharglDg draft cUverter or draft hood outlet a 90 degree elbow, and a five (5) foot long vertical test () stack. A horizontal section of pipe may be 

used on the floor furnace between the cU· 

verter and the 'elbow if necessary to clear, 

any framing used in the installation. Use 

the minimum length of pipe posslblo for 

this section. Use staCk, elbow, and horizon· 

tal section with same cross sectional aren as the diverter outlet. Cover with insulation 

having an R value of not less thlUl 7 (OF-lIR_ 

Ft'/Btu), and an outer layer of alwnlnum 

foll. 

2.2.2 Oll fueled vented home hoatlDg equipment (excludiDg direct vent systems). 

Use flue connections for 011 fueled vented 

floor furnaces as specified in section 35 of 

UL 729-1976, section 34.10 through 34.18 of 

UL 730-1974 for oll fueled vented wall fur- naces and sections 36.2 and 36.3 of UL 896-

1973 for vented room heaters. 

Allow no openiDg on the oll heater botween the heater and the point where the 

flue gas sample is to be taken or the flue ({lIS 

termperature Is to be measured. U a barometric draft regulator is incorporated in the 

heater, it shall be sealed during all tests. 

Cover all elbows and flue connectors between the- heater outlet and a point 12 

inches (304.8mm) downstream of the thermocouple location described in sectlon 2.6 

with insulation having an R value not less 

than 7 (OF-BR-Ft'/Btu) IUld an outer lnyer ofalwniDum foll. 

2.2.3 Direct vent systems. Have the ex· haust/air intake system supplied by the 

manufacturer in place during all teats. Test 

units intended for installation with a varl· 

ety of vent pipe lengths with the minimum 

length recommended by the manufacturer. 

Do not connect a heater employing a direct 

vent system to a chimney or induced draft source. Vent the gas solely on the provision for venting incorporated in the heater and 

the vent/air intake system supplied with it. 

On units which are not designed to preheat the incoming air, cover the first 18 inches of 

vent pipe downstream of the heater outlet 

with insulation having an R value of not 

FEDERAL REGISTER, VOL. 4:1, NO. 91-WEDNESDAY, MAY 10, 1978 
less than '1 ('F-HR-ft'jBtu) and an outer 

layer of aluminum foil. Care should be 

taken to not block the air intake with insulation. 

For units designed to significantly preheat 

the incoming combustion air. co\"er all sur· faces of the vent/air intake system exposed 

to ambient air where the combustion air 

temperature exceeds the room temperature 

by more than 30' F 16.'1C) with insulation 

having an R value not less than '1 ('F·BRft '/Btu) and a layer of aluminum foil. 

2.3 Fuel supply. 

2.3.1 Natural gas. For a vented heater utilizing natural gas, maintain the gas supply 

to the unit under test at a normal inlet test 

pressure immediately ahead of all controls 

at '1 to 10 inches water column. Maintain 

the regulator outlet pressure at normal test 

pressure approximately at that recommend· 

ed by the manufacturer. Use natural gas having a specific gravity of approximately 

0.65 and a higher heatlng value within ±5 

percent of 1,025 Btu per standard cubic foot. 

Determine the actual higher heating value 

in Btu's per standard cubic foot for the natural gas to be used in the test with an error no greater than one percent. 

2.3.2 Propane gas. For a vented heater uti· 

lizing propane gas, maintain the gas supply 

to the unit under test at a normal inlet pres- sure of 11 to 13 inches 'water column and a specific gravity of approximately 1.53. Maintain the regulator outlet pressure, on units so equipped, approximately at that recom· mended by the manufacturer. Use propane having a specific gravity of approximately 

1.53 and a higher heating value withlIi ±5 

percent of 2,500 Btu's per .standard cubic 

foot. Determine the actual higher heating 

value in Btu's per standard cubic foot for 

the propane to be used in the test With an error no greater than one percent. 

2.3.3 Other test gas. Use other test gases 

with characteristics as described in section 

2.2, table VII. of ANSI Standard Z21.1l.1-

1974. Use gases with a measured higher 

heating value within ±5 percent of the 

values specified in the above ANSI stand· 

ard. Determine the actual higher l\eatlng 

value of the gas used in the test with an error no greater than one percent. 

2.3.4 Oil supply. For a vented heater uti· 

lizing fuel oil, use No.1 fuel all (kerosene) - for vaporizing type burners and either No.1 or No.2 fuel oil, as specified by the manu· facturer, for '1nechanlcal atomizing type 

burners. Use No.1 fuel oil with a viscosity 

meeting the specification as specified in UL730-1974, section 36.9. Use test fuel con· forming to the specifications given in tables 

2 and 3 of ANSI Standard Z91.1-1972 for 

No.1 and No.2 fuel oil. Measure the higher 

heating value of the test fuel with an error no greater than one percent. 

2.3.5 Electrical supply. For an auxiliary 

electric component of a vented heater. 

maintain the electrical supply to the test 

unit within one percent of the nameplate 

voltage for the entire test cycle. If a voltage 

range is used for nameplate voltage. main· 

tain the electrical pupply within one percent 

of the mid·point of the nameplate voltage 

range. 

2.4 Burner adJustments. 

2.4.1 Gas burner adjustments. Adjust the . burners of gas fueled vented heaters to 

their maximum Btu ratings at the test pres· sure specified in 2.3 of this section. Correct 

the burner input rate to 60· F <l5.6C) and 

30 inches of mercury barometric pressure 

and within ±2 percent of the hourly Btu 

rating specified by the manufacturer as 

RULES AND REGULATIONS 

measured after 15 minutes of operation 

starting with all parts of the vented heater 

at room temperature. Set the primary air 

shutters in accordance with the manufac· 

turer's recommendations to give & good 

flame at this adjustment. Do not allow the 

deposit of carbon during any test specl!led 

herein. 

If a vent lImiting means is provided on a gas pressure regulator. ha\"e It in pl&cc during all tests. 

2.4.2 Oll burner adjustments. Adjust the 

burners of oU fueled ,ented heaters to give 

the CO. reading recommended by the manu· facturer and an hourly Btu input, during 

the .steady-state performance test described 

below. which is within plus or minus 2 per. 

cent of the heater manufacturer's specWed 

normal hourlY Btu lnput rating. On units 

employing a power burner do not allow 

smoke in the flue to exceed a No. 1 smoke 

during the steady-state performance test as measured by the procedure in ANSI Stand· 

ard Z11.l82-1965 (R1971> (ASTM D 2156-

65(1970». If. on units employln~ & power 

burner. the smoke in the flue exceeds a No. 

1 smoke during the study·state test. read· 

just the burner to give & lower smoke read· 

ing, and, If necessary a lower CO. reading. 

and start all tests over. Maintain the aver· age draft over the fire and in the flue 

during the steady-state performance test at 

that recommended by the manufacturer 

and draft fluctuations at less than 0.005 

inches of water gauge. Do not nake addl· 

tional adjustments to the burner during the 

required series of performance tests. The in· 

struments and measuring apparatus for th1s 

test are described in Section 6.3 of ANSI 

Standard Z91.1-1972. 

2.5 Clrculating air ~tments./ 

2.5.1 Forced air vented wall furnaces (in· 

cluding direct vent systems). Durin~ tests 

maintain the air flow through the heater as specl!led by the manufacturer and operate 

the vented heater with the ouUet air tem· 

perature between 80' F and 130' P above room temperature. If adjustable air discharge registers are pro\ided, adjust them so as to provide the ma.'Cimum possible air 

restriction. Measure air dlscharge tempera· 

ture as specl!led in Section 2.U of ANSI 

Z21.4.9-1975. 

2.5.2. Fan type vented room heaters and 

floor furnaces. During tests on fan type fur· 

naces and heaters, adjust the air flow 

through the heater as specUled by the man· ufacturer. If adjustable air c:llscharge registers are provided. adjust them to pro\'lde 

the maxImum possible air restriction. 

2.6 Localfon of temperat'llTe nu:a.suring 

imtrumentation. 

2.6.1 Gas fueled vented home heating equipment (lncluding direct vent systems). 

For units employing an lntegral dra!t dI· 

verter. install nine thermocouples. wired in 

parallel. in a horIzontal plane in the five 

foot test stack located one foot from the 

test stack inlet. Equallze the length of aU 

thermocouple leads before paralleling. 

Locate one thermocouple in the center of 

the stack. Locate eight thermocouples alon&' 

imaginary lines intersecting at right &niles 

in this horizontal plane at points one t.hlrd 

and two thirds of the distance between the 

center of the stack and the stack Viall. 

For units which employ a draft hood or units which employ a direct vent system 

which does not Significantly preheat the in· 

coming combustion air, install nine thermocouples. wired in parallel, in a horizontal 

plane lcx:a.ted wIthin 12 inches (304.8 mm> of 

the heater ouUet and upstream of the draft 

20183 

hood on units so equlpped. Locate one ther· 

mocouple in the center of the pipe and 

eIght thermocouples along Imaginary lines intersectin~ at right angles in this horizontal plane at points one third and two thirds 

of the distance between the center of the 

pipe and the pipe walL 

For units ."hlch employ direct vent systems that sIinl!Icantly preheat the incoming combustion air. In.stall nine thermocou· 

pIes, wired in parallel. In a plane parallel to 

and located within 6 inches <152.4 mm) of 

the \"ent/alr intake terminal. Equa1.lze the 

length of all thermocouple leads before par. 

alleling. Locate one thermocouple in the 

center of the flue pipe and eight thermocou· 

pIes along Imaginary lines intersecting at 

right angles in this plane at points one third 

and two thirds of the distance between the 

center of the flue pipe and the pipe waIl. 

Use bead·type thermocouples hartng wire 

size not greater than No. 24 American Wire 

Gauge (AWG>. If there is a possibility that 

the thermocouples could recel\"e direct radio 

ation from the fire. Install radiation shields on the fire side of the thermocouples only 

and posUfon the shields so that they do not 

touch the thermocouple junctIons. 

Install thermocouples for measuring con· dltioned warm air temperature as described 

in ANSI Z21.49-19'15. section 2.14 establish 

the temperature of the inlet air by means of a slngle No. 24 AWG bead·type thermocou· 

pIe. suitably shielded from direct radiation 

and located in the center of the plane of 

each inlet air opening. 

2.6.2 on fueled \"ented home heating 

equipment (inclUding direct vent systems). 

Install nine thermocouples. wired In paral. 

lel and having equal length leads, in a plane 

perpendicular to the axis of the flue pfpe. 

Locate this plane at the position shown In 

Figure 3i.4 of UL 730-1974. or FIgures 35.1 

and 35.2 of UL '129-1976 for a s:lngle thermocouple. except that on direct vent systems 

which signifIcantly preheat the Incoming 

combustion air. it shall be located within 6 

inches (l52.4mm) of the ouUet of the ventI 

air intake termlna1. Locate one thermocou· 

pIe in the center of the flue pfpe and eight 

thermocouples along Imaginary lines intersecting at right angles in this plane at 

points one t.hlrd and two thirds of the dlstance between the center of the pfpe and 

pfpewalL 

Use bead·type thermocouples having a. wire slze not greater than No. 24 AWG. If 

there Is a poalbility that the thermocouples 

could receJve direct radiation from the fire, 

In.stall radiation shields on the fire side of 

the thermocouples only and position the 

shields so that they do not touch the thermocouple junctions. 

Install thermocouples for measuring the 

conditioned warm air temperature as deIICrfbed in section 35.12 through 35.17 of UL 

'130-197i. Establish the temperature of the 

inlet air by means of a s:lngle No. 24 AWG 

bead·type thermocouple. suitably shielded 

from direct radiation and located in the 

center of the plane of each inlet air open- ing. 

2.'1 CombU3tion mta.sun:ment imtrumen· 

tation. Analyze the samples of stack and 

flue cases for vented heaters to determine 

the concentration by volume of carbon dlox· 

ide present in the dry gas with instruments· 

Hon which wlll result in a reading having an ac:curacy of ±O.1 percentage POints. 

2.8 Enaw flClD wtrumentation. Install one or more instruments, which measure the rate of gas flow or fuel oll supplied to 

the \"ented heater. and if appropriate. the 

FEDERAL REGlmR, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 
20184 

. electrical energy with an error no greater than one percent. 2.9 Room ambient temperature. During the time period required to perform all the 

testing and measurement procedures speci- fied in section 3.0, maintain the room temperature within ±5' F (±2.8C> of the value 

TIL\ measured during the steady state per- formance test. At no time during these tests 

shall the room temperature exceed 100' F 

(37.8C) or fall below 65' F <18.3C). Use the 

procedure outlined in section 2.1.14 of ANSI 

Standard'Z21.47-1973 to measure room temperature. 

2.10 Equipment used to measure mass flow rate in flue and stack. The tracer gas chosen for this task should have a density which is less than or approximately equal to 

the density of air, and be of a different 

chemical species or different concentration 

from the flue or stack gas to be measured. 

Use a gas unreactive with the environment 

to be encountered., Using instrumentation of 

either the batch or continuous type, meas- ure the concentration of tracer gas with an accuracy of ±2 percent of the value of the 

concentration measured. 

3.0 Testing and measurements. 

3.1 steady-state testing. 3.1.1 Gas Fueled 

Vented Home Heating Equipment (Including Direct Vent Systems). 

Set up the vented heater as specified in 

2.1, 2.2, and 2.3. Begin the steady-state per- formance test by operating the burner and 

the circulating air blower, on units so equipped, with the adjustments specified by 

2.4.1 and 2.5, untU steady-state conditions are attained as indicated by a temperature variation of not more than 3' F (1.7' C) in 

the stack gas temperature for vented heat- ers equipped with draft diverters or 5' F 

(2.8' C) in the flue gas temperature for 

vented heaters equipped with either draft 

hoods or direct vent systems; in three 

successive readings taken 15 minutes apart. 

On units employing draft diverters, meas- ure the room temperature (TIL\) as described 

in 2.9 and measure the steady-state stack 

gas temperature (Ts•

ss.x) using the nine thermocouples located in the 5 foot test stack as specified in 2.6.1. Secure a sample of the 

stack gases in the plane where Ts•ss•x is 

measured and determine the concentration 

by volume of carbon dioxide (Xco.,s) present in dry stack gas. 

On units employing draft hoods or direct 

vent systems, measure the room temperature (TIL\) as described in 2.9 and measure the steady-state flue gas temperature, (Tv.ss), using the nine thermocouples located 

in the flue pipe as described in Section 2.6.1. 

Secure a sample of the flue gas in the plane of temperature measurement and determine 

the concentration by volume of CO. (:&:co..F) 

present in dry flue gas. In addition, for units 

employing draft hoods, secure a sample of 

the stack gas in a horizontal plane in the 

five foot test stack located one foot from 

the test stack inlet; and determine the con- centration by volume of CO. (Xco .. s) present in dry stack gas. 

Determine the steady-state heat input 

rate (QIn) including pUot gas by multiplying the measured higher heating value of the 

test gas by the steady-state gas-mput rate 

corrected to standard conditions of 60' F 

and 30 inches of mercury. Use measured 

values of gas temperature and pressure at 

the meter and the barometric pressure to 

correct the metered gas flow rate to standard conditions. 

Measure the steady-state electric power to 

the power burner (PE) and the steady state 

electrical power to the conditioned air 

blower (BE), on units so equipped. 

RULES AND REGULATIONS 

After the above test measurements have units so equipped, during the first 3 minutes 

been completed on units employing draft di- of the off period and then tum it off, unless 

verters, secure a sample of the flue gases at the vented heater employs a single motor to 

the inlet to the draft diverter and determine drive a power burner and an indoor' air cir. 

the concentration of CO. (:&:co..v) present. In culating blower in which case both shall be 

obtaining this sample of flue gas, move the turned off together. For oU fueled vented 

sampling probe around to assure that an - heaters not equipped with stack dampers,. 

average value is obtained for the Co. concen- maintain the draft in the flue pipe within 

tration. For units with multiple heat· ex- -0.001 and +0.005 inch of water gauge of 

changer outlets, draw and weight a sample the manufacturers recommended on-period from each outlet to obtain the average Co. average draft if the optional test in 3.0 is 

concentration for the unit. Block the draft being carried out, and within ±0.01 inch of 

diverter relief opening and cover the draft water gauge of the average steady.state diverter and flue gas collection box (on a draft if it is not. For a direct vent system 

power ve~ted unit) with insula.tion having an with a flue damper or a vented hoater 

R value no less than 7 ('F-BR-ft 2/Btu) and equipped with both a stack damper and a an outer layer of aluminum foll. However, if barometric damper, close the flue or stack 

the design is such that applying insulation to damper during the cool down test. Keep the 

all areas of the draft diverter housing would main burner(s) off untU equUlbrium condi. 

result·in a reduction of normal air flow over tions are attained, as indicated bY variations 

the heat exchanger, do not insulate those in the flue gas temperature of not more areas of the draft diverter housing. If the than 3' F (1.7' C) between three succcsnivo 

unit is turned off during the process of block- readings taken 15 mlnutes apart. For units 

ing the diverter relief opening, run it untll employing a continuously burning pllot steady-state conditions (as defined above) light, take a third flue gas temperature are again achieved. Then, progressively re- measurement to determine the oft·perlod strict the teSt stack outlet untU the concen- minimum flue gas temperature (TV•

OFF. (co». 

tratlon of CO. in flue gas samples secured For units not employing a continuously · from the test stuck in the plane where Ts.ss.x burning pUot light, set T,.OFF. (co) equal to was measured is within ± 0.2 percentage the room temperature TIL\. During this cool 

points of the previously determined value of down test, measure the energy input rate to ~v.Measurethefluegastemperature(Tv.S3) the pUot light (Qp), if the unit is so usliig the nine thermocouples located in the equipped, within an accuracy of ±3 percent. 

5 foot test stack as specified in 2.6.1. ·Record all measured values. 

3.1.2 OU Fueled Vented Home Heating 3.3 Flue gas temperature measurement.7-

-Equipment (Including Direct Vent Sys- heat up test. No heat uP. test shall be per· tems). 'formed for oU fueled vented heaters 

t d h t equipped with vaporizing type burners. For Set up and adjust the ven e ea er as all other vented heaters, after equUlbrium specified in sections 2.1, 2.2, and 2.3.4. Begin conditions are achieved following the cool 

the stea4Y-s~te performance test by operat- down test and the required measurements 

ing the burner and the circulating air performed turn on the vented heater and 

blower, on unit,'; so equipped, with the ad- measure the flue gas temperature, using the 

justments specified by 2.4.2 and 2.5 untll nine thermocouples described above at 0.5 

steady-state conditions are attained as indi- (T (t » d 2 5 (T «» minutes -~t" cated by a temperatu1:e variation of not Mit' an . Mit .. ... vr more than 5' F (2.8' C) in the flue gas tem- the main burner(s) comes on. Keep the 

perature in three successive readings taken indoor air circulating fan off, on units so 15 minutes apart . equipped, during the first 1.1; minutes of . this warm up test and then turn It on unless 

Do not allow smoke In the flue, for units the vented heater employs a single motor to 

equipped with power burners, to exceed a drive a power burner and an Indoor air eir. 

No. 1 smoke during the steady-state per- culating blower. in which case start both to- fo~ce test as measured by the procedure gether. Record the measured temperatures. descnbed in ANSI Standard Zll.182-1965 During the heat up test for au fueled vented 

(R1971) (ASTM D 2156-65 (1970». Maintain heaters maintain the draft in the flue pipe the average draft over the fire and in the within ±0.01 inch of the manufacturer's 

breeching during the steady·state perform- recommended on.period draft. ance test at that recommended by the man- 3.4 Jacket loss measurement. Conduct a ufacturer and do not allow draft· fluctu- jacket loss test for vented floor furnaces. 

atlons to exceed 0.005 inches of water gauge. Measure the jacket loss (~) in accordance · Measure the room temperature (TIL\) as with the ANSI standard Z21.4£J..1976 Section 

described in 2.9 and measure the steady 2.12. and record result. 

state flue gas temperature (Tv.ss) using nine 3.5 Measurement for determining e!!ectlve. 

thermocouples located in the flue pipe as ness of automatic stack damper. Determine 

described in 2.6.2. Secure a sample of the the effectiveness of an automatio stack 

flue gas in the plane of temperature mea- damper (Do), in vented heaters so equipped, 

surement and determine the concentration by measurlpg the cross sectional area of the 

by volume of CO. (Xco..v) present in dry flue stack (As), the net area of the damper plate ~as. (AD) (the area of the damper pInte minus 

Measure and record the steady-state heat the area of any holes in the plate), and the 

input rate (QID) and the steady-state electr!- angle which the damper plate makes when 

cal power to the power burner (PE) and the closed with a plane perpendicular to the 

conditioned air blower (BE), on units so axis of tlie stack. The equation in section 4.2 

equipped. is then employed to calculate Do. 

3.2 Flue temllerature measurements-cool 3.6 Optional procedure for determining down test. After steady-state testing is com- Dp, D" and Ds for systems equipped with 

pleted, turn off the malIl burner and meas- power burneT&. On power burner systems ure the flue gas temperature by means of not employing automatic stnck dampero, or the nine thermocouples described above, at power burner systems with a stack damper · 1.5 (TV•OFF (t.» and 9 (TV•OFF (t.» minutes. and a draft diverter or draft hood, measure after the burner shuts off. Bypass the Dv during the cool dovm test described in 

damper control on units employing stack section 3.2. On systems for which the flue or dampers and draft diverters or draft hoods stack damper is to be closed during the cool so that the damper remains open during the down test described in section 3.2, measure cool down test. During this off-period, oper- Dp during a separate cool down test. Can· 

ate the indoor ali circulating blower, on duct this separate cool down test after the 

FEDERAL REGISTER, VOL 43, NO. 91-:-WEDtJESDAY, MALlO, 1978 
heat up test described in section 3.3 Is com- pleted. Conduct the test by letting the unit run after the heat up test untn steadY-state 

conditions are reached, as indicated by temperature variation of not more than plus or' 

minus 5" F (2.8" 0) in the flue gas temperature in three successive reacUngs taken 15 - minutes apart, and then shutting the unit 

off with the stack or flue damper controls 

by-passed or adjusted so that the stack or flue damper remains open during the resulting cool down per[od. If a draft was maintained on on fueled units in the flue pipe during the steadY-state performance test described in section 3.1, maintain the same draft (within a range of -.001 to +.005 

inches of water gauge of the average steadystate draft) during this cool down period. Measure the flue gas mass flow rate 

(nq.orr> during the cool,down test described 

above at a specific off-period flue gas temperature and corrected to obtain its value at 

the steadY-state flue gas temperature (TF.$I)' 

using the procedure described below. 

Within one minute after the unit Is shut 

off to start the cool down test for determinIng Dp, begin feeding a tracer gas into the 

combustion chamber at a constant flow rate 

of VTo and at a paint which wm allow for the 

best possible mixing with the air flowing through the chamber. (On units equipped 

with an on fired power burner. the best location for injecting this tracer gas appears 

to be through a hole drilled in the air tube.) 

Periodically measure the value of VT with an instantaneously reading flow meter 

having an accuracy of :1:3 percent of the 

quantity measured. Maintain VT at less than 

1 percent of the air flow rate through the 

furnace. If a combustible tracer gas Is used, 

there should be a delay period between the 

time the unit Is shut off and the time the 

tracer gas Is first injeCted to prevent ignition of the tracer gas. 

Between 5 and 6 minutes after the unit Is 

l'hut off to start the 1:901 down test. measur~ 

the flue gas temperature. T"r.- using the 9 

thermocouples described above. At the same lnsta.D,t the flue gas temperature Is meas- ured, also measure the. percent volumetric 

concentration of tracer gas Or in the flue 

gas in the same plane where T"r_ Is determined. Obtain the concentration of tracer 

gas using an instrument which wm result In an accuracy of ±2 percent In the value of Or 

measured. If use of a continuous reading 

type instrument results In a delay time between drawing of a sample and Its analysis, this delay should be taken into account so that the temperature measurement and the 

measurement of tracer gas concentration c0-

incide. In addition, determine the temperature of the tracer gas entering the flow 

meter (TT) and the barometric pressure (Pa). 

The rate of the flue gas mass flow 

through the vented heater and the factors 

Dp, Dr, and Ds are calculated by the equa- tions in sections 4.3.1, and 4.3.3, of this Ap- pendix. 

4.0 CALCULATION OF DERn-ED RESULTS 

FROll TEST MEASUREMENTS. 

4.1 Annual Fud Utilization Ejliritncll for (;(l$ or Oil 

Vented Home Heat/fill Eljuipmmt. The following calculations lire to be performed to determine the annual fuel 

nllli:aUon elliciency of gas or oil vented hom!) heating equipment. Figure 10 provides an illustration of a worksheet wblch may be used to tabulate the results of test meastuements and calculations. 

4.1.1 System number. Determine the system num~ 

for the type of vented heater being tested in 8IlCOrdante 

with Table t or 2-

4.1.2 Ratio of c:ombustlon air tIIlISS flow rate to 

stoichiometric air tIIlISS flow rate. Determine the ratio 

of combustion air mass flow rate to stoichiometrio air, mass flow rate. Rr.r, from Figure 1 Cor the tes~ fuel. by USing the value of dry flue gas CO. concentration. 

Xco: P, determined in accordance with section 3.1 of 

this Appendix. 

RULES AND REGULATIONS 

4.1.3 Ratio of c<lmbusl1on and n:U~f aIr = IWw rate to st(llchlom,tTl~ air = flow nile. For Si~Clll5 

emplo~ anlntfVO).l dmft dl,,-crttrordral'1 bvA. driermine Ihe rot/o of the sum of combustion n!ld rcl!d aIr mnss flow rata to stO!~blolllrtrl~!Ilr tn:l.!3 flGW mtt! Rr,6, from Fll:Uro 1 for tho type ortest(ucl. bYWIm: tho \<lIUG of dry st~k gas COl c<lnrultratlon. .Yc:owr, dt!erm.lncl. 

in n=rd:mce with Ik"'('Uon3.1 oftbls Al'lX'n<:liL 

4.1.4. A~e s;:nslb!1I bC:lt 1t>5S o.t fulJ.!!i:d t!Qd~' 

state operation. F(!r8~'Stcms cmpto),los: an Inlc;tml dmft 

dinrtel'. dcl.ennlne tho o.,,-cro;;o s;:r.slb!Q hC:lt 1!:'!3 o.t fullload steo.d),"Slaw OlJ(ratlon 14~ • ..t. UI'=d 1:3 n percent, from FIJ;U!'(l2 WIlli: tI.o Vollul.'o( Rr ,6dc!crminei1 

In 4.1.3, the type of lest rutl, and '" Ts...!.5. \Tbml 

whero 

A.Ts.ss=T .... - Ttl& 

Tsa=mC3SUml staek 1:""..3 temperature o.t CulH~d 

stcad)'-5bteoJ)Cr.ltiondctcrmintdlnc.-o:."!.b!:."O 

with s;:~Uon 3.1 of tbis Appendix, In d~ 

Fallrenhclt Til.! "'measured room tcm~rotureoUheoondlt!"nc<1 

sjl:J.C8ln whleb tha nntl!d bC:l!n: 15 tested. in 

de;:recs Fabrenb~Itl dctmlllntd fn c.-ambllre 

with =tIon 2.9 oflulsApp"u<:h.t For systems not emplo)illlt an tnl~ dmft dl,,-mer. 

determine tho tlve~ s=lblc heat 1(Q tit full·lrod 

steady-st:lto opemtion. Ls.& A, ew=ro C3 tI Jl!'n:ent; from Figure' 2 wllllt tho 'I1'aIUtl of Rr.r detcmilnci.l In 

4.1.2, the type oHest Cue!, and AT,.&, WhEro 

where A.T,.ss=T,.ss-Tn.t 

T,.ss",flue I:1lS tcmpcroture o.t Cull.Jc::d stc:1dyo(;lllto opemUon dClcrmlnt1i in n..v.m.!:lnro v.ilh ~ 

lIon3.1oUhIsAppendis,in d~Fallfo:nh~lt. 

Tu "'as defined tloo,,-e. 

4.1.5 Stcad~·"Stato eflldrncy. Cnlrubte tho stoflS'- state cffielenc)' (excluding J:leket 1~), ~~, exp=~4In 

percent and defined as 

-wbera 

'I1ss= IOO-Lt ..... -Ls.ss .. t 

Lr..A"'tlVemlltl btent hC:lt !~!S of thl) test flld dottmllnlld In o.ooord:lllt'll wltb Tal110 3, In 

pe=nt. LS.SS.A"'as deflned In •• 1.4. •• 1.6 Average mtlo ohtc.ek 1:"'..:1 m= fiow mto to fiuo I:tlS m= flow rote at full.JcrA stc:J.d)·"State operal!on. 

Dekmune tbll tltt1Ul:C rotlo of sl~li: I:1lS m= flG." rata tl) flu~ gas m~ Itow rotll o.t full.l~:d sto\l~' tlnta 

opmlUon SIF, from Tllhln 1 or2 (,;1' tbe s)'StCm num~r 

to be te;ted. 

For UlUts \\ilh Inlr;ml dmft dI~~rte;s or dmft hCld:J 

calculate tho qWll'lUty (1.3) (Rr ~!Rr.t'). U tlus caltnlated qWll'lUty Is greater than tho \1IIull of SIF obt:unttl 

from Table 1 or 2. uso It In plore of the \<lIuo from tbe 

Table. In all Oilier c::lIrubUollS In this ~Uon involi'lng the p:m:uncter SIF. 

4.l.7 Etlul\'ll.l~nt fldd sttu:k gas tcm~ture at full· 

load stcad)'-5tAte Opcr!ltlCII. Coltnbto tb~ ¢qUl\'olmt field staek I;1l.S ~('mpcroture o.t (uU·I(!!l.<i ttcid.-cto,to Op~roUOII, Tss,S, fJpressfd In d~ Fo.hn:lllldt and 

drllm>das: 

1 TS.ES= S/F [T,.ss-Tn.d+Tod 

whrro TI'.s3 as d~finlld InA.M T!lA as drfincdInU." 

SIF as defmlld In 4.l.1J 

4.1.6 On-c)oclll timo oonstnnt. Co.!wllto till' on~1!Io 

t1mr constant, ..... expressfd In mlnUtf$ tuld ddlr.td c.:I: 

wbero 

20185 

"'.12 }llnimumfl!l:lJ::tlStcml'~mtu:redllIerenreaba\'ll. 

lOOm t~mpcr.ltnl"\'. Co.!Z!Ib!e the m!nlmum. fille gas t~mpcr!lturo dlt!crez:ro ol:aw ream tempera!ure. y,.""Il'Ufi=~j III d~es FnlIrellheIt tIIld d;llneda3: 

where 

T,.aTrC .. ) 1:3 d~Jl/l,."d {n 4.1.10 TI1A (Il d~fined {n 4.1." 

"'.13 Minimum stt!k 1>'...3 tem~ture dllIerence I!bQ\'~ room t(!mf~r.l!ure_ C;!!:ahte the mlnlmum. stad:: 

i:0IS t~mpcro!u.ri! dll!nen:o ab."'Ve room tem~m!ure. 

Y6 C.ll' ul'=clln d~:s Fchrenllelt an:! defmed as: FCi: S)"S!Cm5 numl;erl!d 1 t~ " and S¥Stelll5 5 

tbrou,;:bSC:lrwb!cb (S!FJD~>D,. 

'l's. ",.X (D,)('l', • .,.r) 

(SIP) (Ds) 

'l'8 .... r='l', •... r 

.... .1. Bf!~ctlvc st.c:k W temf~mtu.re difreren!:e' at shut-d!);m. Col::ubtc thl' ef!C>..-Uv~sta<:k Itas temperatura dUferenro ::t 5hllt-<h?1l. f:s.o.ll' e:lipn'~d {n degree:s l'tIhr~nhdt and ddln~ C3: 

For sr;nt'lll5 numJ;;cred 1 through 4. and ~elIl$ 5 

tbro:l3bSCo:wh!::ll (SIFiD:s>D,. 

(D,) ('l',.o .. r> 

'1!s.o.X (8/,.)(D8) 

l1hml 

D, 1:3 defined 1114.1.13 

fr .0.1' (Il defined fll4.1.l1 

Sf, I:3definedln4.1.6 

D:s I:3dcfim:dln".1.13 

t"rmtemsnumtercd:;'S for wbldl (S!F)Ds;fiD, 

'l's. o. x= '*".0. X 

fEDERAl. REGISTER, VOL. 43, NO. 91-WEOHESDAY, MAY 10, 1978 , 
20186 

Calculate the correction (actor which corrects (or tho 

effcct of outdoor air passing through tho heat exchanger 

during the off·perlod. 0' e. defined as: 

C's=I.22 

4.1.18 MultlpUcntlon Cnctor for sensible bellt loss 

during burneron-e}-clc. CoIeuln1eo multiplication factor' 

for senslbJo bcIl& IOliiI cliIJ1Ilg burner oo-eyelc, Es.oa' 

denncdns: 

K 1000£(1+( n ... p)(Atp» 

S.m.... HBV" 

Wbero 

Cp=O.24 Btu IlCI'poand-dcgrooFIlhrenbett.SpecllIo heat ofalr 

Rr.p=as defined In 4.1.2 

A/p=stolchlometrlc alr/(uel lOtiO determined In 

accordance with Table 3 

llIlVA=average higher heating value o( the test (uol 

detennlned In accordance with Table 3, In 

Dtu'sperpound. - 4.1.17 Multiplication (actor for sensible heat loss durIng burner off-cycle. Calculate a multiplication Cactor for 

sensible hcat loss during burneroff-cycle, KS.OFF, definea as: 

for systems numbered 1-4: 

KS.OFF (TF. SS-TRA+530)1.19(DF) (Ks. on) 

(TF.SS- TRA )0.56 

whero 

530cassumed average indoor temperature in degrees Rankine 

T,.BS as dcfincd In 4.1.4 

TRot as defincd In 4.1.4 

D, as defined In 4.1.13 

Ks... as defined In 4.1.16 

(or systcms numbered 5-8: 

KS·9FP 

(Ts.ss- TnA +530)1.19(Ds) (8M (Ks. on) 

~ (Ts.ss-TRA+70-42)o.56 

where 

TS.S8 as defined In 4.1.7 

DR as dcfined In 4.1.13 

S/, as defined In 4.1.6 

Ks.o D as defined In 4.1.16 " 

530 as defined above 

42 as definQd in 4.1.15 

70 as defincd In 4.2.15 

TRA as defined In 4.1.4 

(or systems numbered !1-12: 

K (TF.ss-TR.4+530)1·19(DF) (Ks. on) 

S.OFF= (TF.ss-TRA+70-42)o.56 

where 

T,.ss as defined In 4.1.4 

D" as defined In 4.1.13 

Ks.o• as defined In4.1.16 

530 as defined above 

42 as defined In 4.1.15 

70 as defined In 4.2.15 

TRA as defined In 4.1.4 

4.1.18 JIIultiplication (actor (or infiltration loss during burncr on-cycle. Calculate a multiplication factor (or 

Inflltration loss during burner on-cycle, Kl. OD. defined as: • (or systems numbered 1-8: 

where 

Kr. on= (CP)(8/F)(Ks. On) 

4> cO.7 Infiltration parameter SI, as defined In 4.1.6 • Ks.o. as defined In 4.1.16 • 4.1.19 Multiplication (actor (or Infiltration loss dunng burner off-cycle. Calculate a multiplication (actor (or 

Inflltratlon loss during burner off-cycle Kl. 01/, defined as: 

(or systems numbered 1-8: 

K (Ts.~s-TRA+530)1.19(Kr.on)(Ds) 

r.ol'F= Ts.ss( - TRA +70-42)0.56 

where 

T".ss as defined In 4.1.7 

530 as defined In 4.1.17 

42 as defined In 4.1.15 

Kl.oD as defined in 4.1.18 

Ds as defined in 4.1.13 

70 as defined In 4.2.15 

TnA as defined in 4.1.4 

4.1.20 Ratio of average burner on·time per cycle to on-cycle time constant. Calculate the ratio oC average burner on·time per cycle to on-cycle time constl!,nt, I •• /T •• , defined as: 

ton 

"Ton 

where 

1 •• =3.87 minutes. the average burner on·time per 

cycle ' .... as defined In 4.1.8 

RULE!S AND REGULATIONS 

4.1.21 Ratio cf average burner off·time per cycle to off-cycle time constent. Calculate the ratio of average burner off·time per cycle to off-cycle time constant. 1.I1IT.II. defined as: 

toll 

"Tolf where . 10 11=13.3 minutes, the average burner oll·tlme per cycle '"oIl as dermed In 4.1.10 

4.1.22 Effective flue gas temperature difference at burner start-up corr~cted (or burner cycling effect. 

CBlculate tho effective flue gas temperature difference 

at burner start-uP. corrected (or burner cycling effect, e".o. expressed In degrees Fahrenheit and deJlned as: 

For systems 1-8: 

Of'. 0= (0,. on) (OF. O. X) 

For systems 9-12: 

OF. 0= (0,• onY< Os) (OF. o. X) 

where Ct.o. is gh'en by: 

C,. on 

1 

1 ("'''.o.x) (e)-lolI'TolI 

(TF.ss-TF.OFF( a;» 

(0,·. o. x) ("'P. o.x) (e-(loD1ToD+toll/rolll) 

(Tp. ss- TF. OFF ( Q»)2 

(or vaporizing type oifburners. 8v.0=0. 

where 

8,.0.r as defined in 4.1.9 

Os as defined In 4.1.15 "',.o.r as defined in 4.1.11 

toU/TolI as defined in 4.1.21 t • .tToff as defined in 4.1.20 

T,.S8 as defined in 4.1.4 

T'.OF!(CO) as defined in 4.1.10 

4.1.23 Effecti,·o flue gas t<>mperature difference at burner shut-down, corrected (or burner cyclln~ effect. 

Calculate the eficctive flue gas temperature difference at burner shut-down, corrected (or burner cycltng 

effect, "'''. 0' For systems 1-8: 

"'F. 0= (C,• olf) ("'Y.O.x) 

For systems 9-12: 

"'F. 0= (C,. orr) (Cs') (,pl'. o.x) 

Where Ct. ollis given by: 

C,. orr 

1 

where 

[ 

(OF.o.x}(e-loo'TOO) 

CIln 1 (T". ss- TF. OFF( Q») 

(OF. O. x) ("'F. o. x)(e-(l.·/roo+lolI/'oll» 

(TF. ss- TF• OFF ( Q) )2 

OlID=I, (or units with continuously operating pilot light O.W, (or units with Intennittcnt ignItion • devices or cycling pilots 

"".0.1" as dermed In 4.1.11 

Os' as defined In 4.1.15 

8,.0.1" as defined in 4.1.9 

tofl/Tolf as defined in 4.1.21 

to./Too as defined In 4.1.20 

T'.B8 as defined in 4.1.~ 

TV.OFF(") as defined in 4.1.10, 

4.1.24 Effective minimum flue gas temperature dlf-

(erence above reom temperature, corrected (or burner 

cycling effect. Calculate the effective minimum flue gas 

temperature difference above room temperature, 'll, .... corrected (or burner cycling effect, expressed in degrees Fahrenheit and defined as: 

,(or systems I!umbered 1-8: 

'1'F •.. '1'F •... X 

(or systems numbered 9-12: 

where 

O's as denned In 4.1.15 'it,. "'. x as denned in 4.1.12 - 4.1.25 Effective steck gas -temperature difference at burner shut-down, corrected (or burner cycling effect. 

CBlculate the effective stllck gns tClllperaturo dtaerNICO at bumer shut-downJ corrected for burnet rycUnl( elTect, "'s.o. expressed In uegrees Jfahrenheit nud dellncd Wli 

(or systems 1-8: 

"'s. 0= 0,. oll"'S.O. X. 

where 

C .. 011 as defined in 4.2.23 "'s,o. x as dcfined In 4.2.11 

4.1.26 Off-cycle sensible Utat loss IntegraUou (!lotors. For systems numbered 1-4. dotcnnlno olf'cycl~ senslblo 

heat loss Integratien (actors, .(0"3 nnd }'4. (rom }o'igurcs :1 

and 4, respectivelY, uslpg valucs of'll,. 0 delhtcd IU6cetion 4.1.23, and loll Toll defined hI seetiou4.1.21. Forsystemsnumbercd5-8,dotermlneoff·oyd~sel1slblo 

heat loss Integration (actors. FG aud }o'O. (rom lo'I~urM 

5 and 6, respectively. using values of tits. o. ll~nuod 111 

section 4.1.2.;, and loll/Tol/ donned In section 4.1.21. 

For systems numbered 9-12. dotrrtnlM off'eyclo sensible heat loss Integration factors, }'u aud 1'0, Irtlltl 

Figures 5 and 6. respectively, using values of'll" 0 dofined In section 4.1.23, and loll/Toll dofined In section 

4.lll.27 Off-cycle Infiltratlen heat loss Intcgrallo1\ 

factors. For systems numbered 1-~. llctermlttcd offcycle Infiltration heat loss Integration rnctors, }'7 nud 

P8, (rom Figures 7 and 8, respectively. using values o! 

'1(s.o defined In section 4.1.2,;. aud 101l1ToII delhlcd In 

section 4.1.21. 

4.1.28 On-cycle senslblo heat loSS. Cnlculato tho on- cycle sensible heat loss or tho system. Ls.ON, oxpressed 

In percent and defined: 

(or systems numbcred 1-8: 

LS.ON=Ls.sS,A 1 ) I ) 

-(KS.ON)(9p.0) COO/Ton (1-,0-;0: ' 

(or ~ystems numbered 9-12: 

1JS. ON = ("Cs) (Ls. S3. A 

-KS•ON)(9f'.0) ColTJ (1-0-!::) 

whero 

Cs as defined In 4.1.15 L.~.8S.A as defined In 4.1.4 

KS.ON as dcllned In 4.1.16 

0, ° as defined In·l.l.2"2 • 100iToD as Ileflned In 4.1.20 , 4.1.2'J Off·cycle sensible heat loss. Calcu\atO tho 

off-cycle sensible heat loss or tho system, Ls. OFF. oJ(' 

pressed In percent and dellncd as: 

(or systems numbered 1-4: 

Ls. OFF= (Ks• OFF) e:~)[(F3)+'1'f'. ",)(F4)], 

(or systems numbered 5-8: 

LS.OFF=(Ks.OFF) et:~) [(F5) 

(or systems numbered IH2: 

+ ('1's, co.x) (F6)], 

LS.OFP"=(KsOFP) G:~) [(F5) 

where 

KS.OFF 

toll 

Ion 

F'3, F4. F;;, and Fa 

""",CD 'l!s. co ,x 

+ ('1'11, co )([16)], 

as defined In 4.1.17 as defined In 4.1.21 as defined In 4.1.20 a~ den ned In 4.1.2G as defined In 4.1.21 

lIS defined In 4.1.13 

4.1.30 On-cycle infiltration heat loss. Caleulatn tho 

on-cycle Infiltration hrat loss of tho systelll, LIoIJIl 

expressed In peteent and defined as: 

(or systems numbered 1-8: 

Ll. oN=Kr. ON(70-42), 

where 

Kr.oN as defined In 4.1.18 

70 as defined In 4.1.4 

42 as defined In 4.1.15 

(or systems numbered 0-12: 

Lr.ON=O 

4.1.31 Oft-cyclo Infiltration heat loss. Caleulato 1110 

off-cycle Infiltration heat loss oC tho system Lr.orF 

exprc..<sed In percent and defined as: 

FEDERAL REGISTER, V01.. 43, NO. 91-WEDNESDAY, MAY 10, 1978 
for systems numbered 143: 

LI.OFF=Kl.0FF(70-42)(;:) [(F7) 

where 

Kr on as defined in 4.1.19 70 • as defined in 4.1.15 

42 as defined in 4.1.15 

411 as defined in 4.1.21 t e• as defined in 4.1.20 

Fl. F8 as defined in 4.1.27 

'i's.co.r ,!IS defined in 4.1.13 

lor systems numbered 9-12: 

+ (~s. 0>.x)(F8)] 

Lr.OFF=O 

4.1.32 Part·load [nel utilization efficiency. Calculato 

the part·load fuel utilization efficiency, e.tpressed in 

percent and defined as: 

for indoor unitsX [Ls, ON+Ls. OFF+L1. ON + LI. OFFJ. 

Cor vented fioor Inmaces 

where 

Ci =3.3 [or vented floor [=es 

Qp =pilot flame fuel mput rate determined in a~rord· 

ance mth sec1:l0n 3.2 of this AppendIx, in Btu's 

per hour 

Qrli=full·load input rate (inrluding pilot flame fuel 

inpnt rate) determined in arcordanro mth Ee~· 

"tIon 3.1 of thiS AppendIX. in Btu's per heur 

L, =jacket loss det<>ritilned in accordance with sec- tlon 3.4 O[ tlus Appendix, in lIercent LL. A as defined in 4.1~~ 

teo as defined in .1.1.20 totl as defined in 4.1.21 

Lt!. Oli as defined in 4.1.28 

LB. OFF as defined in 4.1.29 Lt.o>< as defined in 4.1.30 Lt. OFF as defined in 4.L31 

4.1.33 Annual fuel utih7.ation cfficlenr~·. Cal~13te tho 

annnal fuel unllZlltlon effiCiency, EFFYA, defined as: where 

BFFy .... 

(1]~s) (5200)+ (2.5) (1]") Cg;) (1.7) (4600) 

where - 52OO=the average nnmber of annual heating degree days [or the l:'nited States 

46OO=the average number o[ non heating season hours 

per year that the energy to the pilot lJght Is 

assumed wasted 

1.7 "'average vented heater sizing factor '188 "'as defined in 4.1.5 

'I_ "'as defined in 4.1.32 

Q p "'as defined in 4.1.32 OIl< "'as defined in 4.1.32 4.2 Addttumal1lequirtmentB jIJr l'elltcd Home H(allng Equlpmrnll"tilrzi!lgaStack ~er Fluf)7Jampcr. Calculate 

the stack (or flne) damper enectiveness, D., defined as: 

RULES AND REGULATIONS 

(A' )I.t. (2.6) Ts J 

5 

D.= 5+ (l-~r 

where 

AD=A'DCOI (0) AsccroS'l S>.--:UOII:tl = d tho ste~k dctmnln!!d In ~ 

ccrtlanN' mth se;:Uon M ~r tbb Al'pcndU .. ln 

5qUllIC In~hes 

.4.D=nH = or Ihe dnrup..or pbto drtmnlned In ce- alrdanro \\1th =lIon M ()[ tlUs Appl.'mhs. In squaro ln~lles 

O=tlle !Ulj:lo Iho dnrupn pbte m:tli:C3 Wllt'n d~ with n plane ~rpt'ndl~ubr to the uxl" d th~S1llZk 

determine in =rd3nro With seclUm M ~{ thU 

4.3 ..r.rcCt~~~f IUqulrmcr:!4/cr "cr.lld Ifrx.-:t Ift-=!In, 

E;ulpr.lrnt Ullcln, IdeO( Alt/rr Cao~!::l!l';) ar.i If!!!' Co~lto1. For UnilS obUUnlns rombusl!Qn Illr aml WUlt 

control Illr from IllSlde th~ ~dm~, tile OPProllf1310 fa~tor descrlblllll UIO roUo c;[ t:m-c)'d~ sUl'I: l.ijw to (lUcycle flue flow IS; EI, the roUo 01 c/t-cFlo /lue C~W to on-cyo:Je flue flow at Id~nttrol tempqnlures ID,), and 

the roUo of olt-crde Eu:d;; fiow to oll,,"ydQ sta~k l!~w at IdrnUe:tl tcmperotUl't'S lD.5) fh:lll Ix.l dClmnlntd from 

Table 1. 

4.3.1 Optional pnmduro C,r detmnlr.!ltlQII d Dr Car 

vented homo ll~tllll: rqnlpment emp!~YIll;;: n flOWfr 

burner. CnI~ulat(' th~ rauo (D,.) ~t tha ro!t' c;1 fino j;I1!I 

m= flow t1lnlus:h the Wilted hl'::ltcr dum;;: tI!e c;1l 

pcntd, tn,.oFFI7'"M}: to the rat(' or fiue I::!.:l = lbro' 

during the on·perlw, f:l'.s,5{T,,l<S), and d~l1nN os: 

D 1i1,.OFF(T,.ss) 

p 1i1,.ss(T,.ss) I 

For gas (uclro units or ell lu~IN unlls Crr \\'W~h no draft Is malntnlned during the ste:l'J), SllIle H rool d(l\lll tests: 

riI,. OFR'( T, ss) =1il" OFF( 11-, OFF) 

x[ T,.ss-TnA J)~' [~.OFF+4GOJ\.I~ TP.OFF-TnA T"b's+4GO 

For 011 fueled unlls I('SIed with nn 1nlpo:~d drnIt tl5 

described In =Uon 3.0: 

m,. OFE.( T,.ss) =1iI,. OFF(T~, OFF) 

where 

T"s:J as d~llned In 4.1.4 

T;,OFFCfluc gns t~rnperoture durin;: the GIf'pcr!t<l m~<ured In =r<bnte "11b ~UOII 3.0 d 

tlUs Appt'ndlx.ln d~ Fa!Jmlh~1t 

Tu as defined in 4.1.4 

20187 

4o:C=-convctt:Jn !l:to::' to convert d~ Fahrenh!lt to d~ Poilllklnf.' 

(IOO-Ce)VTP, 

aT m,.oFF(T,.OFF) 

whml 

i'r=>/L-w rat£.' ot tra..-er g:J3 thrcu;:h thl; vented beater 

mea.<uro! In a=dJn::e with section 3.G c! tbl.s 

AI'p£n<ln, in ctlbl~ tett prr mlnute 

Cr=ro:lcentratioll b~' vo:um~ ot t= g33 pmrent In 

th3 llue gas ramll:~ mea.-ured in ~onUnce 

With :iectwn3.1j d thl3 Appendlx. In pacent ',ath~ d,mitlo' th~ fine g33 would have at th~ tem- pcra!!UO 7', In lb, per en. teo It may be app:on- mated by th!! cq1l3t.tJn: 

whero 

Rr.! IU defined In 4.1.2 

A[l-- as d?Jined In 4.1.11) Q,. as d~Jined In U.:l2 

Jllll'A a.:; defmed in U.l5 

4.3.2 Op!!jlUl pro«dure tJr detennIn3tion o!otr-eycle 

draft b.."tor br flue g33 lbW' tor vented h=e heating 

cqwpmrnt onp!:ll'in;: a power bumf'r_ Cs!cubte the off·cy~Je draft b.."tQr fr.llue g33l!ow, D,. defined as: 

fur system:! numbered Z. 4, Ii. 8. or 10: D,=(D,.) 

furs~-stQD numbtt 12: D,c (Dp) fJ).l, 

whm! 

DI' as defined in4.3.l 

D. as defined in 4.2 

4.1.3 Optronal procedure Cordetermirotion or cff-cycIe draft !.1."tor t"r ~ck g:l.l fijW' tilt' vented home hoating tQulpment Mnpb}'mg a ~ .... er burnef'. t's!rnlate the cff-<')'cl~ draft ~Dr lilt' sta:k ga.; tIc .... Ds. defined as: 

fur 5)-stcm numlK-r 2: D.s=1.0 

Cor S)ootem numbcr4: D.s:o(Q.79+D;}!1.4 

Cilt' 5)'St('JO numhtt G: D.s""D. 

f"r 5)'l't('JO number S! 

{

(DQ) (D,,), if D.S: lIeS/F) 

"Ds= (D )(D )+ (O.85-(DQ )(D,,»(Do-l/(S/F» if D >_1_ o p ( __ 1_) ." (SIF) 

whrro 

D, os deJ1nl'd In .. .3.1 

D. as ddlned In 4.2 

. 1 (SIF) 

FEDERAL REGISTER, VOL 43, NO, 9t-WEDNESDAY, MAY 10, 1918 
20188 . 

4.4 Additional requirements for wall fur- nacea equipped with a direct vent system or _ 

noor furnacea designed to take combustion 

a.nd draft control air from an unheated 

space. For wall furnaces utilizing a direct 

vent system or floor furnaces designed to 

take their combustion and draft control air 

from an unheated space (such as a crawlspace), determiile the appropriate SIF 

factor and OF factor from Table 2. If a unit 

is equipped with a power burner, OF, may be 

calcUlated as described in section 4.3.2 using 

the value of Op determined in section 4.3.1 

of this section. 

4.5 Additional requirements for vented 

home heating equipment which modulate or 

va71l fuel input without controUing exceas combustion air. Test a vented heater, which 

is equipped with a mechanism for reducing 

the rate of fuel input but does not provide a means for controlling excess combustion air, 

at its maximum flrlng rate in accordance 

with test procedures in Section 3. Use these 0 

test resUlts to calcuiate a seasonal efficiency and an annual operating cost which is based 

upon a single fixed fuel input rate. 

4.6 National average number of bUTner 

operating hours. Calculate the average 

number of burner operating hours, BOH, defined. as: . BOH=(A)(C)(2080)!average design heatIng requirement)-B(2080). 

where: 

2080=national average annual heating load hours average design heating re- quirement is expressed in KBtu/hr and 

is obtained from Table 4 using the 

proper value of Qour, 

where: 

00UT. tho capacity of the unit. equal to the quantities 

(OJ.n) ('Iss' for room and vall heaters and 

A 

B 

160 

~8": ~)_ fOr floor furna~cca, 

100 ' , 

rounded off to the nearest 1000 Btulhr. 

liB defined 1n 4.1.32 

C=0.77, adjustment factor which serves to 

adjust the calculated design heating reRULES JlND REGULATIONS 

quirement and heatingload hours to the 

actual heating load experienced by a heating system. 

PE=power burner electrical energy input 

rate at full-load steady-state operation - determined in accordance· with section 

3.1 of this Appendix, in kilowatts. 

2=ratio of thtl average length of a heating season in hours to the heating load 

hours. 

BE=circulating-air blower 'electrical 

energy Input rate at. full-load steadystate operation determined in accord- ance with section 3.1 of this Appendix, in kilowatts. ' 

Y=1.00 for ,'ented heaters employing a single motor to drive a power burner 

and air circulating fan or blower, and 

1.38 for all other vented heaters, the 

ratio of average blower on time to aver- age burner time. 

QIN=as defined in 4.1.32. 

Qp=as defined in 4.1.32. 

7Ja=as defined in 4.1.32. 

100,OOO=factor that 'accounts for percent andKBtu. 

4.7 Average annual fuel energy consumption for vented home heating equipment. 

Calculate the average annual fuel energy consumption for vented heaters, Ev, ex- pressed in Btu's per year, and defined as: 

QIN as defined in 4.1.32. 

Qp as defined in 4.1.32. 

BOH as defined in 4.6. 

8760 total nwnber of hours in a year. 

4.8 Average annual auxiliaT1/ electrical 

energy consumption for ventecl home heating equipment. Calculate the average annual auxUlary electrical energy consump- tion, EAE, expressed in kilowatt-hours per 

year and de!ined as: 

EAE=(PE+y BE) (BOH) 

where: 

FE as defined in 4.6. 

BE as defined in 4.6. 

y lis defined In 4.6. 

BOH as defined in 4.6 .. 4.9 Average number of burner operating 

hours for ventecl home heating equipment located in differenfr geographic regions of the 

Umted States ancl in buildings having dYferen( design heating requirements. Crucu· 

late the average number of burner operate ing hours for different typIcal desIgn heating requirements and for the geographlo re- gions of the United states, BOHR, definod as: 

BOHR=(C)(A)(HLH) (typical desIgn heating 

requirement)-B (HLH) 

where: 

A.as defined in 4.6. 

HLH=heating load hours for a speclllc ge- ographic region determined In accord- ance with the heating load hour map in 

Figure 9. 

(Typical design heating requIrQment) as 

given in Table 4 for the approprIate vruue of 

Qour, where oab Is as defined in 4.6. 

B as defined in 4.6. 

C as defined in 4.6. 

A as defined in 4.6. 

4.10 Average annuaZ fuel energ1J con- sumption for ventecl home heating equipment locatecl in different geographic reg/ons 

of the Unitecl States in buildings with difler-

,ent design heating requirements. Calculate 

the average annual fuel energy consumption for a. specific geographIc region and for a speclfic typical design heating requirement, Ev.R' expressed in Btu's per year, and 

defined as: 

EF,R=(QIN-Qp) (BOHR)+(8760) (Qp) 

where: 

QID as defined in 4.1.32. 

Qp as defined In 4.1.32. 

BOHR as 'defined in 4.9. 

8760 as defined in 4.8. 

,4.11 Average annual au:ciliaT1/ electrical 

energy consumption for ventecl home heating equimnent locatecl in clifferent geographic regions of the UnUecl States ancl in buildings with clifferent design heating requirements. Calculate the a.verage annual auxiliary electrical energy consumptlon for !l. spe- clfic geographic region and for a speciflo 

typical design heating requirement, EM,R' 

expressed in kilowatt-hOurs per year and definedaA: 

EAE,R=(PE+y BE) (BOHR) 

where: 

PE as defined in 4.6. 

BE as defined in 4.6. 

y as defined in 4.6. 

BOHR as defined in 4.9. 

FEDERAL' REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 
" 

RULES AND REGULATIONS 

Table 1 

Factors Describing Air Flew Rate for Gas and Oll-F\lcled Vented Hare Heating 

EquiJ:Xl"6lt utilizing Indoor Air for Ccxrbustion and Draft COntrol 

Units Without a Stack Darrper Units Hith a StaCk Daq::er 

but with and 

Draft Hood or Draft Hood or 

20189 

Type of Burner Draft Di'I.'erter Bararetric Draft Control Draft Diverter Bara:etric Draft Control 

Systen i 

Atnospheric or 1 

Vaporizing 

Power * 2 

0 0 Sys- 0 D 5'jS- D D S'jSS/F F S ten i S/F F S ten I S/F F 5 ten I 

2.4 1.0 1.0 3 1.4 1.0 1.0 5 2.4 1.0 D 7 

0 

2.4 0.4 1.0 4 1.4 0.4 0.85 6 2.4 0.4 D 8 0 

",here 

0' 

p 

O.4,if 0 ~ l/(S/F) o 

0.4 + (0.85 - (0.4) (D» (0 - ~S/F» o 0 , if 0 > l/(S/F) 

D (1 - lIt/F)) 0 

o 

'!he above factors were developed U} the Nat.ional Bureau of Standards 

and are based upon infoxmatioo in the public literature, lilboratory 

and c:c:rrputer simulation st:u:lies conducted at tms, and lal:oratory 

and field data obtained by several research ~inrG under contract: 

to NBS and DOE. 

*A power bumer may incorporate a device on its air inlet ... ilich opens 

.the air inlet ... nen the aFPl.i.an:e is in operation and clO"..e5 the air 

inlet ... nen the aFPliance is in the st:.:l.ndlT.l condition. 

Table 2 

D 

SIF F 

1.4 1.0 

1.4 0.4 

Factors Describing Air Flow Rates for Gas or Oil-Fueled Vented Heaters 

Equipped with a Direct Vent System or a Floor Furnace 

Type of Burner 

Atmosphere or 

Vaporizing 

Power 

Un~ts W~thout A Stack 

or Flue Damper Units With a Flue Damper Ty£e of Draft 

System# DF System' DF None - barometric 

9 1.00 11 Do damper 

10 0.40 12 0.-10 x D draft diverter 

0 

The above factors were developed by the National Bureau 

of Standards and are based upon information in the public 

literature, laboratory and computer simulation studies 

conducted at NBS, and laboratory and field data obtained 

by several research firms under contract to NBS and DOE. 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 191. 

D 

s 

D 

0 

(D ) (D') 

0 p 

s/F 

I 

1.4 

2.4 
tJ 

20190 RULES AND REGULATIONS 

Table 3 

Values of Higher Heating Value (HHV), 

A 

Ratio (A/F), and Latent Heat Loss (L 

L,A 

HHV (Btu/1b) 

Fuels A 

No. 1 Oil 19,800 

No. '2 Oil 19,50'0 

Natural Gas 20;120 

Manufactured Gas 18,,500 

Propane 21,500 

Butane 20,890 

'rab1e 4 

Stoi~hiometric Air/Fuel 

for Typical Fuels 

L (%) 

A/F(--) L,A 

14.56 6.55 

14.49 6.50 

14.45 9.55 

11.81 10.14 

15.58 7 .99 

15.36 7.79 

Average and Typical Design Heating Requirements 

for Vented Heaters. with Different 

,Output Capacities. 

II. 

Vented Heaters Output Average Design Typical Design , 

Capacity, QOUT Heating Requirements Heating Requirements 

(Btu/hr) ,. (KBtu/hr) (KBtu/hr) 

5,000 - 10,000 5 5 

11,000 - 16,000 10 5, 10 

17,000,- 25,000 15 10, 15 

26,000 - 34,000 ' . 20 15, 20 

35,000 - 42,000 25 20, 25, 30 

43,000 - 51,000 30 ,25, 30, 35 

52,000 59;000 35 30, 35, 40, 45 

60,000 76,000 40 35, 40, 45~ 50 

FEDERAL REGISTER, VOL. 43, NO. 91-WEDNE~DAY, MAY 10, 1978 
FIGURE 1 

i,I:'1 :1 

'!II 

III. , 

I" "",i '; ":'1 ,;I 

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XC02, S OR XC02. F (%) 

FEDERAL REGISTER, VOL. 43, NO. 91-WEDNESDAY, MAY 10, 1978 

.. 

., 

_A" I • 

14 

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C 

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VI 

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m 

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-20192 

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RULES .~ND REGULATIONS 

FIGURE 2a 

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t 

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o '" 

1 2 

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3 4 

RT,S OR RT,f (--J 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10. 1978 

5 
-

~ 

28.--""'--+T 

RULES AND REGULATIONS 

FIGURE 2b 

. .... . 

::·:··NO.2 OIL . . ....... -

.. .... .. .. .. .. ~ ~ ....... 

.. ~ ... . ...... ....... ..... .. ..... 

~ .......... 

.. .. 

.'"' .. -.. 

. °1~--------2~-------3~--~---4~--~--~r. 

RT,S OR RI,F (--) 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 19111 

20193 
20194 . 

-

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vr 

V) 

vr 

.... 

RULES· AND REGULATIONS 

FIGURE 2c 

I I I 

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°1~--~--~2~~·--~3--~--~4--~--~5 

~:T,S. OR RT,F (--) 

feDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 

~ 

V) 

V) 

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RULES AND REGULATIONS 20195 

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ity,S OR RT,F (--) 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10. 1918 
20196 

-

~ 

-

RULES AND REGULATIONS 

o:~~hJ~Ef~::; _0 __ 00 • 

.. __ .. .. .... -.. - .... .. 

:: :::;:-: PROPANE::::: :: 4F·~~+?~-t~--+---~---- ----+:-:~-~-~-::,: 

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°1~--~~2~~--~3--~--~4--~--~5 

RT,S OR RT ,F (_.J 

FEDERAL REGISTER, VOL 43, NO. 91-WEDNESDAY, MAY 10, 1978 

-L&. 

-
'RULES AND REGULATIONS 20197 

FIGURE 2f 

............... :1.::: .... 

-

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i 

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°1~·--~--~2~~--~3--~---4~----~5 

RT,S OR ~T,F (--) 

FEDERAL IEGISTEl, VOL 43, NO. 91-WEDNESDAY, MAY 10, 197. 
, ,.... 

~ 

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2 I n.'::: :::~ ... 

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FEDEIAI. REGISTB. VOL 43, NO. 91-WE!)NESDAY, MAY 10, 1978 

, • • 

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f II 

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