Tin.

Qr

= average water outlet temperature measured during the first draw of the 24hour simulated use test, °F (°C).

1

=

average water inlet temperature measured during the first draw of the 24hour simulated use test, °F (°C).

= the total energy used by the water heater between cut-out prior to the first draw and cut-out following the first draw, including auxiliary energy such as pilot lights, pumps, fans, etc., Btu (kJ). (Electrical auxiliary energy shall be converted to thermal energy using the following conversion: 1 kWh = 3,412 Btu.)

6.2.2.2 Variable Input Instantaneous Water Heaters. For instantaneous water heaters that have a variable firing rate, two recovery efficiency values are computed, one at the maximum input rate and one at the minimum input rate. The recovery efficiency used in subsequent computations is taken as the average of these two values. The maximum recovery efficiency is computed as:

as:

= the energy used by the instantaneous water heater during the 24-hr simulated use test.

A modification is needed to take into account that the temperature difference between the outlet water temperature and supply water temperature may not be equivalent to the nominal value of 77 °F (135 °F-58 °F) or 42.8 °C (57.2 °C-14.4 °C). The following equations adjust the experimental data to a nominal 77 °F (42.8 °C) temperature rise. The energy used to heat water may be computed as:

6 M; Cpi (Tdel, i-Tin. i)

QHW = Σ

Where:

i=1

ητ

M1 = the mass withdrawn during the ith draw, lb (kg).

Cpi the specific heat of water of the ith draw, Btu/lb °F (kJ/kg (°C).

= the average delivery temperature of the ith draw, °F (°C).

= the average inlet temperature of the ith draw, °F (°C).

nr as calculated in section 6.2.2.2.

The energy required to heat the same quantity of water over a 77 °F (42.8 °C) temperature rise is:

QHW,

HW, 77°F

=

i=1

M.Cpi (135°F-58°F)

or QHW, 42.8°C =

i=1

Where:

Mi

=

the mass withdrawn during the ith draw, lb (kg).

Cpi = the specific heat of water of the ith draw, Btu/lb °F (kJ/kg (°C).

nr as calculated above.

The difference between these two values is: QHWD=QHW, 77 °F

QHW -QHW

or QHWD=QHW, 42.8 °C

7. Ratings for Untested Models

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

7.1 Gas Water Heaters. Ratings obtained for gas water heaters using natural gas can be used for an identical water heater which utilizes propane gas if the input ratings are within ±10%.

7.2 Electric Water Heaters

7.2.1 First-Hour Rating. If an electric storage-type water heater is available with more than one input rating, the manufacturer shall designate the standard input rating, and the water heater need only be tested with heating elements at the designated standard input ratings. The first-hour ratings for units having power input rating less than the designated standard input rating shall be assigned a first-hour rating equivalent to the first draw of the first-hour rating for the electric water heater with the standard input rating. For units having power inputs greater than the designated standard input rating, the first-hour rating shall be equivalent to that measured for the water heater with the standard input rating.

7.2.2 Energy Factor. The energy factor for identical electric storage-type water heaters, with the exception of heating element wattage, may use the energy factor obtained during testing of the water heater with the designated standard input rating.

[63 FR 26008, May 11, 1998; 63 FR 38738, July 20, 1998]

EFFECTIVE DATE NOTE: At 66 FR 4497, Jan. 17, 2001, Appendix E to Subpart B of Part 430 was amended in Section 1 by adding paragraph 1.16, effective Jan. 20, 2004. For the convenience of the user, the added text follows:

FOR

APPENDIX F TO SUBPART B OF PART 430-UNIFORM TEST METHOD MEASURING THE ENERGY CONSUMPTION OF ROOM AIR CONDITIONERS

1. Test method. The test method for testing room air conditioners shall consist of application of the methods and conditions in American National Standard (ANS) Z234.11972, "Room Air Conditioners," sections 4, 5, 6.1, and 6.5, and in American Society of Heating, Refrigerating and Air Conditioning in Engineers (ASHRAE) Standard 16-69, "Method of Testing for Rating Room Air Conditioners."

2. Test conditions. Establish the test conditions described in sections 4 and 5 of ANS Z234.1-1972 and in accordance with ASHRAE Standard 16-69.

3. Measurements. Measure the quantities delineated in section 5 of ANS Z234.1-1972.

4. Calculations. 4.1 Calculate the cooling capacity (expressed in Btu/hr) as required in section 6.1 of ANS Z234.1-1972 and in accordance with ASHRAE Standard 16-69.

4.2 Determine the electrical power input (expressed in watts) as required by section 6.5 of ANS Z234.1-1972 and in accordance with ASHRAE Standard 16-69.

[42 FR 27898, June 1, 1977. Redesignated and amended at 44 FR 37938, June 29, 1979]

APPENDIX G TO SUBPART B OF PART 430-UNIFORM TEST METHOD FOR MEASURING THE ENERGY CONSUMPTION OF UNVENTED HOME HEATING EQUIPMENT

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 withint 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.

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:

Alaska

Hawaii and Territories