After October 30, 2023, any representations made with respect to energy use or efficiency of air circulating fans subject to testing pursuant to § 431.174 must be made in accordance with this appendix. Any optional representations of air circulating fan efficacy at speeds less than the air circulating fan's maximum speed must be accompanied by a representation of the air circulating fan efficacy at maximum speed.

0. Incorporation by Reference

In § 431.173, DOE incorporated by reference the entire standard for AMCA 230-23; however, only enumerated provisions of those documents are applicable as follows. In cases where there is a conflict, the language of this appendix takes precedence over those documents.

0.1 AMCA 230-23:

(a) Section 4, “Definitions/Units of Measurement/Symbols,”;

(b) Section 5, “Instruments and Methods of Measurement,”;

(c) Section 6, “Equipment and Setup,”;

(d) Section 7, “Observations and Conduct of Test,”;

(e) Section 8, “Calculations,” excluding equations 8.5 and 8.6; and

(f) Section 9, “Report and Results of Test,”

1. Definitions

The definitions applicable to this appendix are defined in § 431.172 and in Section 4, “Definitions/Units of Measurement/Symbols,” of AMCA 230-23. In cases where there is a conflict, the definitions in § 431.172 take precedence over AMCA 230-23.

2. Test Procedure for Air Circulating Fans

2.1. General

This section describes the test procedure for air circulating fans.

2.2. Testing

2.2.1. General

The air circulating fan efficacy (Eƒƒcirc) in cubic feet per minute (“CFM”) per watt (“W”) (“CFM/W”) at maximum speed must be determined in accordance with the applicable sections of AMCA 230-23 as listed in section 0.1 of this appendix. In addition, testing must be conducted in accordance with the provisions in sections 2.3 through 2.5 of this appendix. Optional testing speeds lower than maximum speed is permitted. Speeds less than maximum speeds must be expressed at a percentage of maximum speed (e.g., 50 percent) and the air circulating fan efficacy at lower speed must include the speed percentage in its subscript (e.g., Eƒƒcirc,50).

All measurements must be recorded at the resolution of the test instrumentation and calculations must be rounded to the number of significant digits of the resolution of the test instrumentation.

2.3. Air circulating fans without motors

Air circulating fans distributed in commerce without an electric motor must be tested using an electric motor as recommended in the manufacturer's catalogs or distributed in commerce with the air circulating fan. If more than one motor is available in manufacturer's catalogs or distributed in commerce with the air circulating fan, testing must be conducted using the least efficient motor capable of running the fan at the fan's maximum allowable speed.

2.4. Power Supply.

The test must be conducted at the frequency, phase, and voltages specified in this section.

2.4.1. Frequency.

Air circulating fans rated for operation with only 60 Hz power supply must be tested with 60 Hz electricity. Air circulating fans capable of operating with 50 Hz and 60 Hz electricity must be tested with 60 Hz electricity.

2.4.2. Phase.

Air circulating fans rated for operation for single- or multi-phase power supply must be tested with single- or multi-phase power electricity, respectively. Air circulating fans, capable of operating with single- and multi-phase power supply, must be tested using multi-phase electricity.

2.4.3. Voltage.

Select the supply voltage as follows:

(a) For air circulating fans tested with single-phase electricity, the supply voltage must be:

(1) 120 V if the air circulating fan's minimum rated voltage is 120 V or the lowest rated voltage range contains 120 V,

(2) 240 V if the air circulating fan's minimum rated voltage is 240 V or the lowest rated voltage range contains 240 V, or

(3) The air circulating fan's minimum rated voltage (if a voltage range is not given) or the mean of the lowest rated voltage range, in all other cases.

(b) For air circulating fans tested with multi-phase electricity, the supply voltage must be

(1) 240 V if the air circulating fan's minimum rated voltage is 240 V or the lowest rated voltage range contains 240 V, or

(2) The air circulating fan's minimum rated voltage (if a voltage range is not given) or the mean of the lowest rated voltage range, in all other cases.

2.5. Stability Conditions.

In addition to the test requirements specified in sections 7.1 and 7.3 of AMCA 230-23, the following conditions must be met to establish system stability prior to collecting test data:

(a) Test voltage shall be captured at least every five seconds and shall not vary by more than ±1 percent during each test. Barometric pressure, dry bulb temperature and wet bulb temperature in the general test area for calculation of air density must be captured at least every five seconds and the calculated ambient air density shall not vary by more than ±1 percent during each test.

(b) After a run-in time of at least 15 minutes, record the fan speed in rpm, the input power in watts, and load differential in pound-force for at least 3 120-second intervals. Repeat these measurements over additional 120-second intervals until:

(1) The average fan speed of the last 120-second interval varies by less than the absolute value of 1 percent or 1 rpm, whichever is greater, when compared to the average fan speed measured during the previous 120-second test interval;

(2) The average input power of the last 120-second interval varies by less than the absolute value of 1 percent or 1 watt, whichever is greater, compared to the average input power measured during the previous 120-second test interval;

(3) The average load differential of the last 120-second interval varies by less than the absolute value of 1 percent compared to the average load differential during the previous 120-second test interval; and

(4) The slopes of a linear fit trendline calculated from the individual data collected for fan speed, input power, and load differential during at least three 120-second intervals include both positive and negative values (e.g., two positive and one negative slope value or one positive and two negative slope values). If three positive or three negative slopes are determined in succession, additional sampling intervals are required until slopes from three successive 120-second intervals include both positive and negative values.

2.6. Calculation of Ambient Air Density.

For any references to ambient air density, ρ0, in AMCA 230-23, calculate ρ0, expressed in kg/m3 when using SI units or lbm/ft3 when using I-P units, as follows:

where pb is the measured barometric pressure of the air, Td0 is the measured dry-bulb temperature of the air, pp is the partial vapor pressure, R is the gas constant, which are all determined according to section 8.2 of AMCA 230-23. [88 FR 27393, May 1, 2023, as amended at 88 FR 53376, Aug. 8, 2023]