1. Testing conditions.

1.1 Installation.

1.1.1 Electric heater. Install heater according to manufacturer's instructions. Heaters shall be connected to an electrical supply circuit of nameplate voltage with a wattmeter installed in the circuit. The wattmeter shall have a maximum error not greater than one percent.

1.1.2 Unvented gas heater. Install heater according to manufacturer's instructions. Heaters shall be connected to a gas supply line with a gas displacement meter installed between the supply line and the heater according to manufacturer's specifications. The gas displacement meter shall have a maximum error not greater than one percent. Gas heaters with electrical auxiliaries shall be connected to an electrical supply circuit of nameplate voltage with a wattmeter installed in the circuit. The wattmeter shall have a maximum error not greater than one percent.

1.1.3 Unvented oil heater. Install heater according to manufacturer's instructions. Oil heaters with electric auxiliaries shall be connected to an electrical supply circuit of nameplate voltage with a wattmeter installed in the circuit. The wattmeter shall have a maximum error not greater than one percent.

1.2 Temperature regulating controls. All temperature regulating controls shall be shorted out of the circuit or adjusted so that they will not operate during the test period.

1.3 Fan controls. All fan controls shall be set at the highest fan speed setting.

1.4 Energy supply.

1.4.1 Electrical supply. Supply power to the heater within one percent of the nameplate voltage.

1.4.2 Natural gas supply. For an unvented gas heater utilizing natural gas, maintain the gas supply to the heater with a normal inlet test pressure immediately ahead of all controls at 7 to 10 inches of water column. The regulator outlet pressure at normal supply test pressure shall be approximately that recommended by the manufacturer. The natural gas supplied should have a higher heating value within ±5 percent of 1,025 Btu's per standard cubic foot. Determine the 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. Alternatively, the test can be conducted using “bottled” natural gas of a higher heating value within ±5 percent of 1,025 Btu's per standard cubic foot as long as the actual higher heating value of the bottled natural gas has been determined with an error no greater than one percent as certified by the supplier.

1.4.3 Propane gas supply. For an unvented gas heater utilizing propane, maintain the gas supply to the heater with a normal inlet test pressure immediately ahead of all controls at 11 to 13 inches of water column. The regulator outlet pressure at normal supply test pressure shall be that recommended by the manufacturer. The propane supplied should have a higher heating value of within±5 percent of 2,500 Btu's per standard cubic foot. Determine the higher heating value in Btu's per standard foot, for the propane to be used in the test, with an error no greater than one percent. Alternatively, the test can be conducted using “bottled” propane of a higher heating value within ±5 percent of 2,500 Btu's per standard cubic foot as long as the actual higher heating value of the bottled propane has been determined with an error no greater than one percent as certified by the supplier.

1.4.4 Oil supply. For an unvented oil heater utilizing kerosene, determine the higher heating value in Btu's per gallon with an error no greater than one percent. Alternatively, the test can be conducted using a tested fuel of a higher heating value within ±5 percent of 137,400 Btu's per gallon as long as the actual higher heating value of the tested fuel has been determined with an error no greater than one percent as certified by the supplier.

1.5 Energy flow instrumentation. Install one or more energy flow instruments which measure, as appropriate and with an error no greater than one percent, the quantity of electrical energy, natural gas, propane gas, or oil supplied to the heater.

2. Testing and measurements.

2.1 Electric power measurement. Establish the test conditions set forth in section 1 of this appendix. Allow an electric heater to warm up for at least five minutes before recording the maximum electric power measurement from the wattmeter. Record the maximum electric power (PE) expressed in kilowatts.

Allow the auxiliary electrical system of a forced air unvented gas, propane, or oil heater to operate for at least five minutes before recording the maximum auxiliary electric power measurement from the wattmeter. Record the maximum auxiliary electric power (PA) expressed in kilowatts.

2.2 Natural gas, propane, and oil measurement. Establish the test conditions as set forth in section 1 of this appendix. A natural gas, propane, or oil heater shall be operated for one hour. Using either the nameplate rating or the energy flow instrumentation set forth in section 1.5 of this appendix and the fuel supply rating set forth in sections 1.4.2, 1.4.3, or 1.4.4 of this appendix, as appropriate, determine the maximum fuel input (PF) of the heater under test in Btu's per hour. The energy flow instrumentation shall measure the maximum fuel input with an error no greater than one percent.

2.3 Pilot light measurement. Except as provided in section 2.3.1 of this appendix, measure the energy input rate to the pilot light (Qp), with an error no greater than 3 percent, for unvented heaters so equipped.

2.3.1 The measurement of Qp is not required for unvented heaters where the pilot light is designed to be turned off by the user when the heater is not in use (i.e., for units where turning the control to the OFF position will shut off the gas supply to the burner(s) and the pilot light). This provision applies only if an instruction to turn off the unit is provided on the heater near the gas control value (e.g., by label) by the manufacturer.

2.4 Electrical standby mode power measurement. Except as provided in section 2.4.1 of this appendix, for all electric heaters and unvented heaters with electrical auxiliaries, measure the standby power (PW,SB) in accordance with the procedures in IEC 62301 Second Edition (incorporated by reference; see §430.3), with all electrical auxiliaries not activated. Voltage shall be as specified in section 1.4.1 Electrical supply of this appendix. The recorded standby power (PW,SB) shall be rounded to the second decimal place, and for loads greater than or equal to 10W, at least three significant figures shall be reported.

2.4.1 The measurement of PW,SB is not required for heaters designed to be turned off by the user when the heater is not in use (i.e., for units where turning the control to the OFF position will shut off the electrical supply to the heater). This provision applies only if an instruction to turn off the unit is provided on the heater (e.g., by label) by the manufacturer.

3. Calculations.

3.1 Annual energy consumption for primary electric heaters. For primary electric heaters, calculate the annual energy consumption (EE) expressed in kilowatt-hours per year and defined as:

EE = 2080(0.77)DHR

where:

2080 = national average annual heating load hours

0.77 = adjustment factor

DHR = design heating requirement and is equal to PE/1.2 in kilowatts.

PE = as defined in 2.1 of this appendix

1.2 = typical oversizing factor for primary electric heaters

3.2 Annual energy consumption for primary electric heaters by geographic region of the United States. For primary electric heaters, calculate the annual energy consumption by geographic region of the United States (ER) expressed in kilowatt-hours per year and defined as:

ER = HLH(0.77) (DHR)

where:

HLH = heating load hours for a specific region determined from Figure 1 of this appendix in hours

0.77 = as defined in 3.1 of this appendix

DHR = as defined in 3.1 of this appendix

3.3 Rated output for electric heaters. Calculate the rated output (Qout) for electric heaters, expressed in Btu's per hour, and defined as:

Qout = PE (3,412 Btu/kWh)

where:

PE = as defined in 2.1 of this appendix

3.4 Rated output for unvented heaters using either natural gas, propane, or oil. For unvented heaters using either natural gas, propane, or oil equipped without auxiliary electrical systems, the rated output (Qout), expressed in Btu's per hour, is equal to PF, as determined in section 2.2 of this appendix.

For unvented heaters using either natural gas, propane, or oil equipped with auxiliary electrical systems, calculate the rated output (Qout), expressed in Btu's per hour, and defined as:

Qout = PF + PA (3,412 Btu/kWh)

where:

PF = as defined in 2.2 of this appendix in Btu/hr

PA = as defined in 2.1 of this appendix in Btu/hr

(Energy Policy and Conservation Act, Pub. L. 94-163, as amended by Pub. L. 94-385; Federal Energy Administration Act of 1974, Pub. L. 93-275, as amended by Pub. L. 94-385; Department of Energy Organization Act, Pub. L. 95-91; E.O. 11790, 39 FR 23185)

[43 FR 20132, May 10, 1978. Redesignated and amended at 44 FR 37938, June 29, 1979; 49 FR 12157, Mar. 28, 1984; 77 FR 74571, Dec. 17, 2012]