10 C.F.R. Appendix N to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Furnaces and Boilers
Title 10 - Energy
1.0 Scope. The scope of this appendix is as specified in section 2.0 of ANSI/ASHRAE Standard 103–1993. 2.0 Definitions. Definitions include the definitions specified in section 3 of ANSI/ASHRAE Standard 103–1993 and the following additional and modified definitions: 2.1 ANSI/ASHRAE Standard 103–1993 means the test standard published in 1993 by ASHRAE, approved by the American National Standards Institute (ANSI) on October 4, 1993, and entitled “Method of Testing for Annual Fuel Utilization Efficiency of Residential Central Furnaces and Boilers” (with errata of October 24, 1996). 2.2 ASHRAE means the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 2.3 Thermal stack damper means a type of stack damper which is dependent for operation exclusively upon the direct conversion of thermal energy of the stack gases to open the damper. 2.4 Isolated combustion system. The definition of isolation combustion system in section 3 of ANSI/ASHRAE Standard 103–1993 is incorporated with the addition of the following: “The unit is installed in an un-conditioned indoor space isolated from the heated space.” 3.0 Classifications. Classifications are as specified in section 4 of ANSI/ASHRAE Standard 103–1993. 4.0 Requirements. Requirements are as specified in section 5 of ANSI/ASHRAE Standard 103–1993. 5.0 Instruments. Instruments must be as specified in section 6 of ANSI/ASHRAE Standard 103–1993. 6.0 Apparatus. The apparatus used in conjunction with the furnace or boiler during the testing shall be as specified in section 7 of ANSI/ASHRAE Standard 103–1993 except for the second paragraph of section 7.2.2.2 and except for section 7.2.2.5, and as specified in section 6.1 of this appendix. 6.1 Downflow furnaces. Install the internal section of vent pipe the same size as the flue collar for connecting the flue collar to the top of the unit, if not supplied by the manufacturer. Do not insulate the internal vent pipe during the jacket loss test (if conducted) described in section 8.6 of ANSI/ASHRAE Standard 103–1993 or the steady-state test described in section 9.1 of ANSI/ASHRAE Standard 103–1993. Do not insulate the internal vent pipe before the cool-down and heat-up tests described in sections 9.5 and 9.6, respectively, of ANSI/ASHRAE Standard 103–1993. If the vent pipe is surrounded by a metal jacket, do not insulate the metal jacket. Install a 5-ft test stack of the same cross sectional area or perimeter as the vent pipe above the top of the furnace. Tape or seal around the junction connecting the vent pipe and the 5-ft test stack. Insulate the 5-ft test stack with insulation having an R-value not less than 7 and an outer layer of aluminum foil. (See Figure 3–E of ANSI/ASHRAE Standard 103–1993.) 7.0 Testing conditions. The testing conditions shall be as specified in section 8 of ANSI/ASHRAE Standard 103–1993 with errata of October 24, 1996, except for section 8.6.1.1; and as specified in section 7.1 of this appendix. 7.1 Measurement of jacket surface temperature. The jacket of the furnace or boiler shall be subdivided into 6-inch squares when practical, and otherwise into 36-square-inch regions comprising 4 in. × 9 in. or 3 in. × 12 in. sections, and the surface temperature at the center of each square or section shall be determined with a surface thermocouple. The 36-square-inch areas shall be recorded in groups where the temperature differential of the 36-square-inch area is less than 10 °F for temperature up to 100 °F above room temperature and less than 20 °F for temperature more than 100 °F above room temperature. For forced air central furnaces, the circulating air blower compartment is considered as part of the duct system and no surface temperature measurement of the blower compartment needs to be recorded for the purpose of this test. For downflow furnaces, measure all cabinet surface temperatures of the heat exchanger and combustion section, including the bottom around the outlet duct, and the burner door, using the 36 square-inch thermocouple grid. The cabinet surface temperatures around the blower section do not need to be measured (See figure 3–E of ANSI/ASHRAE Standard 103–1993.) 8.0 Test procedure. Testing and measurements shall be as specified in section 9 of ANSI/ASHRAE Standard 103–1993 except for sections 9.5.1.1, 9.5.1.2.1, 9.5.1.2.2, 9.5.2.1, and section 9.7.1. ; and as specified in sections 8.1, 8.2, 8.3, 8.4, and 8.5, of this appendix. 8.1 Input to interrupted ignition device. For burners equipped with an interrupted ignition device, record the nameplate electric power used by the ignition device, PEIG, or use PEIG=0.4 kW if no nameplate power input is provided. Record the nameplate ignition device on-time interval, tIG, or measure the on-time period at the beginning of the test at the time the burner is turned on with a stop watch, if no nameplate value is given. Set tIG=0 and PEIG=0 if the device on-time is less than or equal to 5 seconds after the burner is on. 8.2 Gas- and oil-fueled gravity and forced air central furnaces without stack dampers cool-down test. Turn off the main burner after steady-state testing is completed, and measure the flue gas temperature by means of the thermocouple grid described in section 7.6 of ANSI/ASHRAE 103–1993 at 1.5 minutes (TF,OFF(t3)) and 9 minutes (TF,OFF(t4)) after the burner shuts off. An integral draft diverter shall remain blocked and insulated, and the stack restriction shall remain in place. On atmospheric systems with an integral draft diverter or draft hood, equipped with either an electromechanical inlet damper or an electro-mechanical flue damper that closes within 10 seconds after the burner shuts off to restrict the flow through the heat exchanger in the off-cycle, bypass or adjust the control for the electromechanical damper so that the damper remains open during the cool-down test. For furnaces that employ post purge, measure the length of the post-purge period with a stopwatch. The time from burner OFF to combustion blower OFF (electrically de-energized) shall be recorded as tp. For the case where tp is intended to be greater than 180 seconds, stop the combustion blower at 180 seconds and use that value for tp. Measure the flue gas temperature by means of the thermocouple grid described in section 7.6 of ANSI/ASHRAE 103–1993 at the end of post-purge period, tp (TF,OFF(tp)), and at the time (1.5 + tp) minutes (TF,OFF(t3)) and (9.0 + tp) minutes (TF,OFF(t4)) after the main burner shuts off. For the case where the measured tp is less than or equal to 30 seconds, it shall be tested as if there is no post purge and tp shall be set equal to 0. 8.3 Gas- and oil-fueled gravity and forced air central furnaces without stack dampers with adjustable fan control—cool-down test. For a furnace with adjustable fan control, this time delay will be 3.0 minutes for non-condensing furnaces or 1.5 minutes for condensing furnaces or until the supply air temperature drops to a value of 40 °F above the inlet air temperature, whichever results in the longest fan on-time. For a furnace without adjustable fan control or with the type of adjustable fan control whose range of adjustment does not allow for the delay time specified above, the control shall be bypassed and the fan manually controlled to give the delay times specified above. For a furnace which employs a single motor to drive the power burner and the indoor air circulating blower, the power burner and indoor air circulating blower shall be stopped together. 8.4 Gas-and oil-fueled boilers without stack dampers cool-down test. After steady-state testing has been completed, turn the main burner(s) OFF and measure the flue gas temperature at 3.75 (TF,OFF(t3)) and 22.5 (TF,OFF(t4)) minutes after the burner shut off, using the thermocouple grid described in section 7.6 of ANSI/ASHRAE 103–1993. During this off-period, for units that do not have pump delay after shutoff, no water shall be allowed to circulate through the hot water boilers. For units that have pump delay on shutoff, except those having pump controls sensing water temperature, the pump shall be stopped by the unit control and the time t For boilers that employ post purge, measure the length of the post-purge period with a stopwatch. The time from burner OFF to combustion blower OFF (electrically de-energized) shall be recorded as tP. For the case where tP is intended to be greater than 180 seconds, stop the combustion blower at 180 seconds and use that value for tP. Measure the flue gas temperature by means of the thermocouple grid described in section 7.6 of ANSI/ASHRAE 103–1993 at the end of the post purge period tP(TF,OFF(tP)) and at the time (3.75 + tP) minutes (TF,OFF(t3)) and (22.5 + tP) minutes (TF,OFF(t4)) after the main burner shuts off. For the case where the measured tP is less or equal to 30 seconds, it shall be tested as if there is no post purge and tP shall be set to equal 0. 8.5 Direct measurement of off-cycle losses testing method. [Reserved.] 9.0 Nomenclature. Nomenclature shall include the nomenclature specified in section 10 of ANSI/ASHRAE Standard 103–1993 and the following additional variables: Effmotor=Efficiency of power burner motor PEIG=Electrical power to the interrupted ignition device, kW RT,a=RT,F if flue gas is measured =RT,S if stack gas is measured RT,F=Ratio of combustion air mass flow rate to stoichiometric air mass flow rate RT,S=Ratio of the sum of combustion air and relief air mass flow rate to stoichiometric air mass flow rate tIG=Electrical interrupted ignition device on-time, min. Ta,SS,X=TF,SS,X if flue gas temperature is measured, °F =TS,SS,X if stack gas temperature is measured, °F yIG=ratio of electrical interrupted ignition device on-time to average burner on-time yP=ratio of power burner combustion blower on-time to average burner on-time 10.0 Calculation of derived results from test measurements. Calculations shall be as specified in section 11 of ANSI/ASHRAE Standard 103–1993 and the October 24, 1996, Errata Sheet for ASHRAE Standard 103–1993, except for appendices B and C; and as specified in sections 10.1 through 10.8 and Figure 1 of this appendix. 10.1 Annual fuel utilization efficiency. The annual fuel utilization efficiency (AFUE) is as defined in sections 11.2.12 (non-condensing systems), 11.3.12 (condensing systems), 11.4.12 (non-condensing modulating systems) and 11.5.12 (condensing modulating systems) of ANSI/ASHRAE Standard 103–1993, except for the definition for the term EffyHS in the defining equation for AFUE. EffyHS is defined as: EffyHS=heating seasonal efficiency as defined in sections 11.2.11 (non-condensing systems), 11.3.11 (condensing systems), 11.4.11 (non-condensing modulating systems) and 11.5.11 (condensing modulating systems) of ANSI/ASHRAE Standard 103–1993 and is based on the assumptions that all weatherized warm air furnaces or boilers are located out-of-doors, that warm air furnaces which are not weatherized are installed as isolated combustion systems, and that boilers which are not weatherized are installed indoors. 10.2 National average burner operating hours, average annual fuel energy consumption and average annual auxiliary electrical energy consumption for gas or oil furnaces and boilers. 10.2.1 National average number of burner operating hours. For furnaces and boilers equipped with single stage controls, the national average number of burner operating hours is defined as: BOHSS=2,080 (0.77) A DHR–2,080 B where: 2,080=national average heating load hours 0.77=adjustment factor to adjust the calculated design heating requirement and heating load hours to the actual heating load experienced by the heating system DHR=typical design heating requirements as listed in Table 8 (in unit of kBtu/h) of ANSI/ASHRAE Standard 103–1993, using the proper value of QOUT defined in 11.2.8.1 of ANSI/ASHRAE Standard 103–1993 A=100,000 / [341,300(yPPE+yIGPEIG+yBE)+(QIN–QP)EffyHS], for forced draft unit, indoors =100,000 / [341,300(yPPE Effmotor+yIGPEIG+y BE)+(QIN–QP)EffyHS], for forced draft unit, ICS, =100,000 / [341,300(yPPE(1–Effmotor)+yIGPEIG+y BE)+(QIN–QP)EffyHS], for induced draft unit, indoors, and =100,000 / [341,300(yIGPEIG+yBE)+(QIN–QP)EffyHS], for induced draft unit, ICS B=2 QP(EffyHS)(A) / 100,000 where: Effmotor=Power burner motor efficiency provided by manufacturer, =0.50, an assumed default power burner efficiency if not provided by manufacturer. 100,000=factor that accounts for percent and kBtu PE=burner electrical power input at full-load steady-state operation, including electrical ignition device if energized, as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993 yP=ratio of induced or forced draft blower on-time to average burner on-time, as follows: 1 for units without post purge; 1+(tP/3.87) for single stage furnaces with post purge; 1+(tP/10) for two-stage and step modulating furnaces with post purge; 1+(tP/9.68) for single stage boilers with post purge; or 1+(tP/15) for two stage and step modulating boilers with post purge. PEIG=electrical input rate to the interrupted ignition device on burner (if employed), as defined in 8.1 of this appendix yIG=ratio of burner interrupted ignition device on-time to average burner on-time, as follows: 0 for burners not equipped with interrupted ignition device; (tIG/3.87) for single stage furnaces; (tIG/10) for two-stage and step modulating furnaces; (tIG/9.68) for single stage boilers; or (tIG/15) for two stage and step modulating boilers. tIG=on-time of the burner interrupted ignition device, as defined in 8.1 of this appendix tP=post purge time as defined in 8.2 (furnace) or 8.4 (boiler) of this appendix =0 if tP is equal to or less than 30 second. y=ratio of blower or pump on-time to average burner on-time, as follows: 1 for furnaces without fan delay; 1 for boilers without a pump delay; 1+(t 1+(t 1+(t 1+(t BE=circulating air fan or water pump electrical energy input rate at full load steady-state operation, as defined in ANSI/ASHRAE Standard 103–1993 QIN=as defined in 11.2.8.1 of ANSI/ASHRAE Standard 103–1993 QP=as defined in 11.2.11 of ANSI/ASHRAE Standard 103–1993 EffyHS=as defined in 11.2.11 (non-condensing systems) or 11.3.11.3 (condensing systems) of ANSI/ASHRAE Standard 103–1993, percent, and calculated on the basis of: ICS installation, for non-weatherized warm air furnaces; indoor installation, for non-weatherized boilers; or outdoor installation, for furnaces and boilers that are weatherized. 2=ratio of the average length of the heating season in hours to the average heating load hours t t−=as defined in 9.6.1 of ANSI/ASHRAE Standard 103–1993 10.2.1.1 For furnaces and boilers equipped with two stage or step modulating controls the average annual energy used during the heating season, EM, is defined as: EM=(QIN−QP) BOHSS+(8,760−4,600)QP where: QIN=as defined in 11.4.8.1.1 of ANSI/ASHRAE Standard 103–1993 QP=as defined in 11.4.12 of ANSI/ASHRAE Standard 103–1993 BOHSS=as defined in section 10.2.1 of this appendix, in which the weighted EffyHS as defined in 11.4.11.3 or 11.5.11.3 of ANSI/ASHRAE Standard 103–1993 is used for calculating the values of A and B, the term DHR is based on the value of QOUT defined in 11.4.8.1.1 or 11.5.8.1.1 of ANSI/ASHRAE Standard 103–1993, and the term (yPPE+yIGPEIG+yBE) in the factor A is increased by the factor R, which is defined as: R=2.3 for two stage controls =2.3 for step modulating controls when the ratio of minimum-to-maximum output is greater than or equal to 0.5 =3.0 for step modulating controls when the ratio of minimum-to-maximum output is less than 0.5 A=100,000/[341,300(yPPE+yIGPEIG+y BE) R+(QIN−QP) EffyHS], for forced draft unit, indoors =100,000/[341,300(yPPE Effmotor+yIGPEIG+y BE) R+(QIN−QP)EffyHS], for forced draft unit, ICS, =100,000/[341,300(yPPE(1–Effmotor)+yIGPEIG+y BE) R+(QIN−QP) EffyHS], for induced draft unit, indoors, and =100,000/[341,300(yIGPEIG+y BE) R+(QIN−QP) EffyHS], for induced draft unit, ICS where: Effmotor=Power burner motor efficiency provided by manufacturer, =0.50, an assumed default power burner efficiency if none provided by manufacturer. EffyHS=as defined in 11.4.11.3 or 11.5.11.3 of ANSI/ASHRAE Standard 103–1993, and calculated on the basis of: —ICS installation, for non-weatherized warm air furnaces —indoor installation, for non-weatherized boilers —outdoor installation, for furnaces and boilers that are weatherized 8,760=total number of hours per year 4,600=as specified in 11.4.12 of ANSI/ASHRAE Standard 103–1993 10.2.1.2 For furnaces and boilers equipped with two stage or step modulating controls the national average number of burner operating hours at the reduced operating mode is defined as: BOHR=XREM/QIN,R where: XR=as defined in 11.4.8.7 of ANSI/ASHRAE Standard 103–1993 EM=as defined in section 10.2.1.1 of this appendix QIN,R=as defined in 11.4.8.1.2 of ANSI/ASHRAE Standard 103–1993 10.2.1.3 For furnaces and boilers equipped with two stage controls the national average number of burner operating hours at the maximum operating mode (BOHH) is defined as: BOHH=XHEM/QIN where: XH=as defined in 11.4.8.6 of ANSI/ASHRAE Standard 103–1993 EM=as defined in section 10.2.1.1 of this appendix QIN=as defined in 11.4.8.1.1 of ANSI/ASHRAE Standard 103–1993 10.2.1.4 For furnaces and boilers equipped with step modulating controls the national average number of burner operating hours at the modulating operating mode (BOHM) is defined as: BOHM=XHEM/QIN,M where: XH=as defined in 11.4.8.6 of ANSI/ASHRAE Standard 103–1993 EM=as defined in section 10.2.1.1 of this appendix QIN,M=QOUT,M/(EffySS,M/100) QOUT,M=as defined in 11.4.8.10 or 11.5.8.10 of ANSI/ASHRAE Standard 103–1993, as appropriate EffySS,M=as defined in 11.4.8.8 or 11.5.8.8 of ANSI/ASHRAE Standard 103–1993, as appropriate, in percent 100=factor that accounts for percent 10.2.2 Average annual fuel energy consumption for gas or oil fueled furnaces or boilers. For furnaces or boilers equipped with single stage controls the average annual fuel energy consumption (EF) is expressed in Btu per year and defined as: EF=BOHSS(QIN−QP)+8,760 QP where: BOHSS=as defined in 10.2.1 of this appendix QIN=as defined in 11.2.8.1 of ANSI/ASHRAE Standard 103–1993 QP=as defined in 11.2.11 of ANSI/ASHRAE Standard 103–1993 8,760=as specified in 10.2.1 of this appendix 10.2.2.1 For furnaces or boilers equipped with either two stage or step modulating controls EF is defined as: EF=EM + 4,600QP where: EM=as defined in 10.2.1.1 of this appendix 4,600=as specified in 11.4.12 of ANSI/ASHRAE Standard 103–1993 QP=as defined in 11.2.11 of ANSI/ASHRAE Standard 103–1993 10.2.3 Average annual auxiliary electrical energy consumption for gas or oil fueled furnaces or boilers. For furnaces or boilers equipped with single stage controls the average annual auxiliary electrical consumption (EAE) is expressed in kilowatt-hours and defined as: EAE=BOHSS(yPPE +yIGPEIG+yBE) where: BOHSS=as defined in 10.2.1 of this appendix PE=as defined in 10.2.1 of this appendix yP=as defined in 10.2.1 of this appendix yIG=as defined in 10.2.1 of this appendix PEIG=as defined in 10.2.1 of this appendix y=as defined in 10.2.1 of this appendix BE=as defined in 10.2.1 of this appendix 10.2.3.1 For furnaces or boilers equipped with two stage controls EAE is defined as: EAE=BOHR(yPPER+yIGPEIG+yBER) + BOHH(yPPEH+yIGPEIG+y BEH) where: BOHR=as defined in 10.2.1.2 of this appendix yP=as defined in 10.2.1 of this appendix PER=as defined in 9.1.2.2 and measured at the reduced fuel input rate, of ANSI/ASHRAE Standard 103–1993 yIG=as defined in 10.2.1 of this appendix PEIG=as defined in 10.2.1 of this appendix y=as defined in 10.2.1 of this appendix BER=as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993, measured at the reduced fuel input rate BOHH=as defined in 10.2.1.3 of this appendix PEH=as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993, measured at the maximum fuel input rate BEH=as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993, measured at the maximum fuel input rate 10.2.3.2 For furnaces or boilers equipped with step modulating controls EAE is defined as: EAE=BOHR(yP PER+yIGPEIG+y BER)+BOHM(yPPEH+yIGPEIG+y BEH) where: BOHR=as defined in 10.2.1.2 of this appendix yP=as defined in 10.2.1 of this appendix PER=as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993, measured at the reduced fuel input rate yIG=as defined in 10.2.1 of this appendix PEIG=as defined in 10.2.1 of this appendix y=as defined in 10.2.1. of this appendix BER=as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993, measured at the reduced fuel input rate BOHM=as defined in 10.2.1.4 of this appendix PEH=as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993, measured at the maximum fuel input rate BEH=as defined in 9.1.2.2 of ANSI/ASHRAE Standard 103–1993, measured at the maximum fuel inputs rate 10.3 Average annual electric energy consumption for electric furnaces or boilers. For electric furnaces and boilers the average annual energy consumption (EE) is expressed in kilowatt-hours and defined as: EE=100(2,080)(0.77)DHR/(3.412 AFUE) where: 100=to express a percent as a decimal 2,080=as specified in 10.2.1 of this appendix 0.77=as specified in 10.2.1 of this appendix DHR=as defined in 10.2.1 of this appendix 3.412=conversion to express energy in terms of watt-hours instead of Btu AFUE=as defined in 11.1 of ANSI/ASHRAE Standard 103–1993, in percent, and calculated on the basis of: ICS installation, for non-weatherized warm air furnaces; indoor installation, for non-weatherized boilers; or outdoor installation, for furnaces and boilers that are weatherized. 10.4 Energy factor. 10.4.1 Energy factor for gas or oil furnaces and boilers. Calculate the energy factor, EF, for gas or oil furnaces and boilers defined as, in percent: where: EF=average annual fuel consumption as defined in 10.2.2 of this appendix. EAE=as defined in 10.2.3 of this appendix. EffyHS=Annual Fuel Utilization Efficiency as defined in 11.2.11, 11.3.11, 11.4.11 or 11.5.11 of ANSI/ASHRAE Standard 103–1993, in percent, and calculated on the basis of: ICS installation, for non-weatherized warm air furnaces; indoor installation, for non-weatherized boilers; or outdoor installation, for furnaces and boilers that are weatherized. 3,412=conversion factor from kilowatt to Btu/h 10.4.2 Energy factor for electric furnaces and boilers. The energy factor, EF, for electric furnaces and boilers is defined as: EF=AFUE where: AFUE=Annual Fuel Utilization Efficiency as defined in section 10.3 of this appendix, in percent 10.5 Average annual energy consumption for furnaces and boilers located in a different geographic region of the United States and in buildings with different design heating requirements. 10.5.1 Average annual fuel energy consumption for gas or oil-fueled furnaces and boilers located in a different geographic region of the United States and in buildings with different design heating requirements. For gas or oil-fueled furnaces and boilers the average annual fuel energy consumption for a specific geographic region and a specific typical design heating requirement (EFR) is expressed in Btu per year and defined as: EFR=(EF−8,760 QP)(HLH/2,080)+8,760 QP where: EF=as defined in 10.2.2 of this appendix 8,760=as specified in 10.2.1 of this appendix QP=as defined in 11.2.11 of ANSI/ASHRAE Standard 103–1993 HLH=heating load hours for a specific geographic region determined from the heating load hour map in Figure 1 of this appendix 2,080=as defined in 10.2.1 of this appendix 10.5.2 Average annual auxiliary electrical energy consumption for gas or oil-fueled furnaces and boilers located in a different geographic region of the United States and in buildings with different design heating requirements. For gas or oil-fueled furnaces and boilers the average annual auxiliary electrical energy consumption for a specific geographic region and a specific typical design heating requirement (EAER) is expressed in kilowatt-hours and defined as: EAER=EAE (HLH/2,080) where: EAE=as defined in 10.2.3 of this appendix HLH=as defined in 10.5.1 of this appendix 2,080=as specified in 10.2.1 of this appendix 10.5.3 Average annual electric energy consumption for electric furnaces and boilers located in a different geographic region of the United States and in buildings with different design heating requirements. For electric furnaces and boilers the average annual electric energy consumption for a specific geographic region and a specific typical design heating requirement (EER) is expressed in kilowatt-hours and defined as: EER=100 (0.77) DHR HLH/(3.412 AFUE) where: 100=as specified in 10.3 of this appendix 0.77=as specified in 10.2.1 of this appendix DHR=as defined in 10.2.1 of this appendix HLH=as defined in 10.5.1 of this appendix 3.412=as specified in 10.3 of this appendix AFUE=as defined in 10.3 of this appendix, in percent 10.6 Annual energy consumption for mobile home furnaces 10.6.1 National average number of burner operating hours for mobile home furnaces (BOHSS). BOHSS is the same as in 10.2.1 of this appendix, except that the value of EffyHS in the calculation of the burner operating hours, BOHSS, is calculated on the basis of a direct vent unit with system number 9 or 10. 10.6.2 Average annual fuel energy for mobile home furnaces (EF). EF is same as in 10.2.2 of this appendix except that the burner operating hours, BOHSS, is calculated as specified in 10.6.1 of this appendix. 10.6.3 Average annual auxiliary electrical energy consumption for mobile home furnaces (EAE). EAE is the same as in 10.2.3 of this appendix, except that the burner operating hours, BOHSS, is calculated as specified in 10.6.1 of this appendix. 10.7 Calculation of sales weighted average annual energy consumption for mobile home furnaces. In order to reflect the distribution of mobile homes to geographical regions with average HLHMHF value different from 2,080, adjust the annual fossil fuel and auxiliary electrical energy consumption values for mobile home furnaces using the following adjustment calculations. 10.7.1 For mobile home furnaces the sales weighted average annual fossil fuel energy consumption is expressed in Btu per year and defined as: EF,MHF=(EF−8,760 QP)HLHMHF/2,080+8,760 QP where: EF=as defined in 10.6.2 of this appendix 8,760=as specified in 10.2.1 of this appendix QP=as defined in 11.2.11 of ANSI/ASHRAE Standard 103–1993 HLHMHF=1880, sales weighted average heating load hours for mobile home furnaces 2,080=as specified in 10.2.1 of this appendix 10.7.2 For mobile home furnaces the sales weighted average annual auxiliary electrical energy consumption is expressed in kilowatt-hours and defined as: EAE,MHF=EAEHLHMHF/2,080 where: EAE=as defined in 10.6.3 of this appendix HLHMHF=as defined in 10.7.1 of this appendix 2,080=as specified in 10.2.1 of this appendix 10.8 Direct determination of off-cycle losses for furnaces and boilers equipped with thermal stack dampers. [Reserved.] [62 FR 26157, May 12, 1997, as amended at 62 FR 53510, Oct. 14, 1997]
Title 10: Energy
PART 430—ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS
Subpart B—Test Procedures
Appendix N to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Furnaces and Boilers
