This subpart contains provisions regarding fans and blowers, pursuant to Part C of Title III of the Energy Policy and Conservation Act, as amended, 42 U.S.C. 6311-6317. This subpart does not cover “ceiling fans” as that term is defined and addressed in part 430 this chapter, nor does it cover “furnace fans” as that term is defined and addressed in part 430 of this chapter.

Air circulating axial panel fan means an axial housed air circulating fan head without a cylindrical housing or box housing that is mounted on a panel, orifice plate or ring.

Air circulating fan means a fan that has no provision for connection to ducting or separation of the fan inlet from its outlet using a pressure boundary, operates against zero external static pressure loss, and is not a jet fan.

Air circulating fan discharge area means the area of a circle having a diameter equal to the blade tip diameter.

Air circulating fan outlet area means the gross inside area measured at the plane of the outlet opening.

Air-cooled steam condenser means a device for rejecting heat to the atmosphere through the indirect condensing of steam inside air-cooled finned tubes.

Axial inline fan means a fan with an axial impeller and a cylindrical housing with or without turning vanes.

Axial panel fans means an axial fan, without cylindrical housing, that includes a panel, orifice plate, or ring with brackets for mounting through a wall, ceiling, or other structure that separates the fan's inlet from its outlet.

Basic model, with respect to fans and blowers, means all units of fans and blowers manufactured by one manufacturer, having the same primary energy source, and having essentially identical electrical, physical, and functional (e.g., aerodynamic) characteristics that affect energy consumption. In addition:

(1) All variations of blade pitches of an adjustable-pitch axial fan may be considered a single basic model; and

(2) All variations of impeller widths and impeller diameters of a given full-width impeller and full-diameter impeller centrifugal fan may be considered a single basic model.

Box fan means an axial housed air circulating fan head without a cylindrical housing that is mounted on a panel, orifice plate or ring and is mounted in a box housing.

Centrifugal housed fan means a fan with a centrifugal or mixed flow impeller in which airflow exits into a housing that is generally scroll-shaped to direct the air through a single fan outlet. A centrifugal housed fan does not include a radial impeller.

Centrifugal inline fan means a fan with a centrifugal or mixed flow impeller in which airflow enters axially at the fan inlet and the housing redirects radial airflow from the impeller to exit the fan in an axial direction.

Centrifugal unhoused fan means a fan with a centrifugal or mixed flow impeller in which airflow enters through a panel and discharges into free space. Inlets and outlets are not ducted. This fan type also includes fans designed for use in fan arrays that have partition walls separating the fan from other fans in the array.

Cross-flow fan means a fan or blower with a housing that creates an airflow path through the impeller in a direction at right angles to its axis of rotation and with airflow both entering and exiting the impeller at its periphery. Inlets and outlets can optionally be ducted.

Cylindrical air circulating fan means an axial housed air circulating fan head with a cylindrical housing that is not a Positive Pressure Ventilator as defined in AMCA 240-15 (incorporated by reference, see § 431.173).

Evaporative field erected closed-circuit cooling tower means a structure which rejects heat to the atmosphere through the indirect cooling of a process fluid stream to a lower temperature by partial evaporation of an external recirculating water flow.

Evaporative field erected open-circuit cooling tower means a structure which rejects heat to the atmosphere through the direct cooling of a water stream to a lower temperature by partial evaporation.

Fan or blower means a rotary bladed machine used to convert electrical or mechanical power to air power, with an energy output limited to 25 kilojoule (kJ)/kilogram (kg) of air. It consists of an impeller, a shaft and bearings and/or driver to support the impeller, as well as a structure or housing. A fan or blower may include a transmission, driver, and/or motor controller.

Fan static air power means the static power delivered to air by the fan or blower; it is proportional to the product of the fan airflow rate, the fan static pressure and the compressibility coefficient and is calculated in accordance with section 7.8.1 of AMCA 210-16 (incorporated by reference, see § 431.173), using fan static pressure instead of fan total pressure.

Fan total air power means the total power delivered to air by the fan or blower; it is proportional to the product of the fan airflow rate, the fan total pressure and the compressibility coefficient and is calculated in accordance with section 7.8.1 of AMCA 210-16 (incorporated by reference, see § 431.173).

Field erected air-cooled (dry) cooler means a structure which rejects heat to the atmosphere from a fluid, either liquid, gas or a mixture thereof, flowing through an air-cooled internal coil.

Field erected evaporative condenser means a structure which rejects heat to the atmosphere through the indirect condensing of a refrigerant in an internal coil by partial evaporation of an external recirculating water flow.

Full-diameter impeller means maximum impeller diameter with which a given fan or blower basic model is distributed in commerce.

Full-width impeller means the maximum impeller width with which a given fan or blower basic model is distributed in commerce.

Housed air circulating fan head means an air circulating fan with an axial or centrifugal impeller, and a housing.

Housed centrifugal air circulating fan means a housed air circulating fan head with a centrifugal or radial impeller in which airflow exits into a housing that is generally scroll shaped to direct the air through a single, narrow fan outlet.

Induced flow fan means a type of laboratory exhaust fan with a nozzle and windband; the fan's outlet airflow is greater than the inlet airflow due to induced airflow. All airflow entering the inlet exits through the nozzle. Airflow exiting the windband includes the nozzle airflow plus the induced airflow.

Jet fan means a fan designed and marketed specifically for producing a high velocity air jet in a space to increase its air momentum. Jet fans are rated using thrust. Inlets and outlets are not ducted but may include acoustic silencers.

Packaged air-cooled (dry) cooler means a device which rejects heat to the atmosphere from a fluid, either liquid, gas or a mixture thereof, flowing through an air-cooled internal coil.

Packaged evaporative closed-circuit cooling tower means a device which rejects heat to the atmosphere through the indirect cooling of a process fluid stream in an internal coil to a lower temperature by partial evaporation of an external recirculating water flow.

Packaged evaporative condenser means a device which rejects heat to the atmosphere through the indirect condensing of a refrigerant in an internal coil by partial evaporation of an external recirculating water flow.

Packaged evaporative open-circuit cooling tower means a device which rejects heat to the atmosphere through the direct cooling of a water stream to a lower temperature by partial evaporation.

Power roof ventilator means a fan with an internal driver and a housing to prevent precipitation from entering the building. It has a base designed to fit over a roof or wall opening, usually by means of a roof curb.

Radial-housed fan means a fan with a radial impeller in which airflow exits into a housing that is generally scroll-shaped to direct the air through a single fan outlet. Inlets and outlets can optionally be ducted.

Safety Fan means:

(1) A reversible axial fan in cylindrical housing that is designed and marketed for use in ducted tunnel ventilation that will reverse operation under emergency ventilation conditions;

(2) A fan for use in explosive atmospheres tested and marked according to the English version of ISO 80079-36:2016 (incorporated by reference, see § 431.173);

(3) An electric-motor-driven-Positive Pressure Ventilator as defined in AMCA 240-15 (incorporated by reference, see § 431.173);

(4) A fan bearing a listing for “Power Ventilators for Smoke Control Systems” in compliance with UL 705 (incorporated by reference, see § 431.173); or

(5) A laboratory exhaust fan designed and marketed specifically for exhausting contaminated air vertically away from a building using a high-velocity discharge.

Unhoused air circulating fan head means an air circulating fan without a housing, having an axial impeller with a ratio of fan-blade span (in inches) to maximum rate of rotation (in revolutions per minute) less than or equal to 0.06. The impeller may or may not be guarded.

(a) Certain material is incorporated by reference into this subpart with the approval of the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that specified in this section, DOE must publish a document in the Federal Register and the material must be available to the public. All approved incorporation by reference (IBR) material is available for inspection at DOE, and at the National Archives and Records Administration (NARA). Contact DOE at: the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, 1000 Independence Ave. SW, EE-5B, Washington, DC 20585, (202) 586-9127, [email protected], https://www.energy.gov/eere/buildings/building-technologies-office. For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or email: [email protected]. The material may be obtained from the sources in the following paragraphs of this section.

(b) AMCA. Air Movement and Control Association International, Inc., 30 West University Drive, Arlington Heights, IL 60004-1893; (847) 394-0150; www.amca.org.

(1) ANSI/AMCA Standard 210-16 (“AMCA 210-16”), Laboratory Methods of Testing Fans for Certified Aerodynamic Performance Rating, ANSI-approved August 26, 2016; IBR approved for § 431.172; appendix A to this subpart. (Co-published as ASHRAE 51-16).

(2) ANSI/AMCA Standard 214-21 (“AMCA 214-21”), Test Procedure for Calculating Fan Energy Index (FEI) for Commercial and Industrial Fans and Blowers, ANSI-approved March 1, 2021; IBR approved for § 431.174; appendix A to this subpart.

(3) ANSI/AMCA Standard 230-23 (“AMCA 230-23”), Laboratory Methods of Testing Air Circulating Fans for Rating and Certification, ANSI-approved February 10, 2023. IBR approved for appendix B to this subpart.

(4) ANSI/AMCA Standard 240-15 (“AMCA 240-15”), Laboratory Methods of Testing Positive Pressure Ventilators for Aerodynamic Performance Rating, ANSI-approved May 9, 2015; IBR approved for § 431.172.

(c) ISO. International Organization for Standardization, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland; www.iso.org.

(1) ISO 5801:2017(E) (“ISO 5801:2017”), Fans—Performance testing using standardized airways, Third Edition, approved September 2017; IBR approved for appendix A to this subpart.

(2) ISO 80079-36:2016, Explosive atmospheres—Part 36: Non-electrical equipment for explosive atmospheres—Basic method and requirements, Edition 1.0, February 2016; IBR approved for § 431.172.

(d) UL. Underwriters Laboratories, 333 Pfingsten Road, Northbrook, Illinois, 60062; www.shopulstandards.com.

(1) UL 705, Standard for Safety for Power Ventilators, Edition 7, July 19, 2017 (including revisions through August 19, 2022); IBR approved for § 431.172.

(2) [Reserved].

(a) Scope for fans and blowers other than air circulating fans. A fan or blower, other than an air circulating fan is subject to the test procedure in this section if it meets the following criteria:

(1) Is a centrifugal housed fan; radial housed fan; centrifugal inline fan; centrifugal unhoused fan; centrifugal power roof ventilator exhaust fan; centrifugal power roof ventilator supply fan; axial inline fan; axial panel fan; or axial power roof ventilator fan;

(2) Is not:

(i) A radial housed unshrouded fan with blade diameter at tip less than 30 inches or a blade width of less than 3 inches;

(ii) A safety fan;

(iii) An induced flow fan;

(iv) A jet fan;

(v) A cross-flow fan;

(vi) A fan manufactured exclusively to be powered by internal combustion engines;

(vii) A fan that create a vacuum of 30 inches water gauge or greater;

(viii) A fan that is designed and marketed to operate at or above 482 degrees Fahrenheit (250 degrees Celsius); or

(ix) A fan and blower embedded in the equipment listed in paragraph (a)(3) of this section;

(3) Is not an embedded fan subject to the following exclusions:

(i) The test procedure in this section does not apply to fans or blowers that are embedded in:

(A) Single phase central air conditioners and heat pumps rated with a certified cooling capacity less than 65,000 British thermal units per hour (“Btu/h”) cooling capacity, that are subject to DOE's energy conservation standard at 10 CFR 430.32(c);

(B) Three phase, air-cooled, small commercial packaged air-conditioning and heating equipment rated with a certified cooling capacity less than 65,000 Btu/h cooling capacity, that are subject to DOE's energy conservation standard at § 431.97(b);

(C) Transport refrigeration (i.e., Trailer refrigeration, Self-powered truck refrigeration, Vehicle-powered truck refrigeration, Marine/Rail container refrigerant);

(D) Vacuum cleaners;

(E) Heat Rejection Equipment: Packaged evaporative open-circuit cooling towers; Evaporative field-erected open-circuit cooling towers; Packaged evaporative closed-circuit cooling towers; Evaporative field-erected closed-circuit cooling towers; Packaged evaporative condensers; Field-erected evaporative condensers; Packaged air-cooled (dry) coolers; Field-erected air-cooled (dry) cooler; Air-cooled steam condensers; Hybrid (water saving) versions of all of the previously listed equipment that contain both evaporative and air-cooled heat exchange sections;

(F) Air curtains; and

(G) Direct expansion-dedicated outdoor air system that are subject to any of DOE's test procedures in appendix B to subpart F of this part.

(ii) The test procedure in this section does not apply to supply or condenser fans or blowers that are embedded in:

(A) Air-cooled commercial package air conditioners and heat pumps (“CUAC,” “CUHP”) with a certified cooling capacity between 5.5 ton (65,000 Btu/h) and 63.5 ton (760,000 Btu/h) that are subject to DOE's energy conservation standard at § 431.97(b);

(B) Water-cooled and evaporatively-cooled commercial air conditioners that are subject to DOE's energy conservation standard at § 431.97(b);

(C) Water-source heat pumps that are subject to DOE's energy conservation standard at § 431.97(b);

(D) Single package vertical air conditioners and heat pumps that are subject to DOE's energy conservation standard at § 431.97(d);

(E) Packaged terminal air conditioners (“PTAC”) and packaged terminal heat pumps (PTHP) that are subject to DOE's energy conservation standard at § 431.97(c);

(F) Computer room air conditioners that are subject to DOE's energy conservation standard at § 431.97(e); and

(G) Variable refrigerant flow multi-split air conditioners and heat pumps that are subject to DOE's energy conservation standard at § 431.97(f); and

(4) In addition, the test procedure is only applicable to fan or blower duty points with the following characteristics, measured or calculated in accordance with the test procedure set forth in appendix A of this subpart:

(i)(A) Fan shaft input power equal to or greater than 1 horsepower; or

(B) Fan electrical power equal to or greater than 0.89 kW; and

(ii)(A) Fan static air power equal to or less than 150 horsepower for fans using a static pressure basis fan energy index (“FEI”) in accordance with the required test configuration listed in table 7.1 of AMCA 214-21 (incorporated by reference, see § 431.173); or

(B) Fan total air power equal to or less than 150 horsepower for fans using a total pressure basis FEI in accordance with the required test configuration listed in table 7.1 of AMCA 214-21;

(b) Scope for air circulating fans. The test procedure in this section applies to all air circulating fans with input power greater than or equal to 125W at maximum speed.

(c) Testing and calculations for fans and blowers other than air circulating fans. Determine the FEI, the fan electrical power (“FEP”), and fan shaft power (as applicable) at each duty point, as specified by the manufacturer, using the test procedure set forth in appendix A of this subpart.

(d) Testing and calculations for air circulating fan. Determine the air circulating fan efficacy in cubic feet per minute per watt at maximum speed using the test procedure set forth in appendix B to this subpart.

After October 30, 2023, any representations made with respect to energy use or efficiency of fans and blowers subject to testing pursuant to § 431.174 must be made in accordance with this appendix. Any optional representations of fan energy index in the optional test configuration listed in table 7.1 of AMCA 214-21 (FEIoptional) must be accompanied by a representation of fan energy index in the required test configuration listed in table 7.1 of AMCA 214-21 (FEI).

In § 431.173, DOE incorporated by reference the entire standard for AMCA 210-16, AMCA 214-21, and ISO 5801:2017; 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 210-16:

(a) Section 3, “Definitions/Units of Measure/Symbols”;

(b) Section 4, “Instruments and Methods of Measurement” ;

(c) Section 5, “Test Setups and Equipment”;

(d) Section 6, “Observation and Conduct of Test”;

(e) Section 7, “Calculations” excluding Section 7.9.2, “Conversion to other rotational speeds and air densities with compressible flow” and Section 7.9.3, “Conversion formulae for new densities and new rotational speeds”;

0.2. AMCA 214-21:

(a) Section 2, “References (Normative),” as referenced in section 2.2 of this appendix;

(b) Section 3, “Definitions,” as referenced in section 1 of this appendix;

(c) Section 4, “Calculation of the FEI for a Single Duty Point,” as referenced in section 2.6 of this appendix;

(d) Section 5, “Reference Fan Electrical Power (FEPref),” as referenced in section 2.6 of this appendix;

(e) Section 6.1, “Wire-to-Air Testing at the Required Duty Point,” as referenced in section 2.2 of this appendix;

(f) Section 6.2, “Calculated Ratings Based on Wire-to-Air Testing,” as referenced in section 2.2 of this appendix;

(g) Section 6.3, “Bare Shaft Fans,” as referenced in section 2.2 of this appendix;

(h) Section 6.4, “Fans with Polyphase Regulated Motor”, excluding Section 6.4.1.4, “Requirements for the VFD, if included” and Section 6.4.2.4, “Combined motor-VFD efficiency” as referenced in section 2.2 of this appendix;

(i) Section 7, “Testing,” as referenced in sections 2.2 and 2.3 of this appendix;

(j) Section 8, “Rating Development”, excluding Section 8.2.2, “Separate Fan and Motor Tests” and Section 8.3, “Appurtenances” as referenced in section 2.2 of this appendix;

(k) Annex D, “Motor Performance Constants (Normative),” as referenced in section 2.2 of this appendix;

(l) Annex E, “Calculation Methods for Fans Tested Shaft-to-Air,” as referenced in section 2.2 of this appendix;

(m) Annex G, “Wire-to-Air Measurement—Calculation to Other Speeds and Densities (Normative),” as referenced in section 2.2 of this appendix;

(n) Annex J, “Other data and calculations to be retained,” as referenced in section 2.2 of this appendix; and

(o) Annex K, “Proportionality and Dimensional Requirements (Normative),” as referenced in section 2.2 of this appendix.

0.3. ISO 5801:2017:

(a) Section 3, “Terms and Definitions”;

(b) Section 4, “Symbols, Abbreviated Terms and Subscripts”;

(c) Section 5, “General”;

(d) Section 6, “Test Configurations”;

(e) Section 7, “Carrying out the Test”;

(f) Section 8, “Airways for Duct Configuration”;

(g) Section 9, “Standardized Test Chambers”;

(h) Section 10, “Various Component Parts for a Laboratory Setup”;

(i) Section 11, “Standard Test Configurations”;

(j) Section 12, “Measurements”;

(k) Section 13, “Reference Conditions”;

(l) Section 15, “Calculations”;

(m) Section 16, “Fan Characteristic Curves”; and

(n) Section 17, “Uncertainty Analysis”.

The definitions applicable to this appendix are defined in § 431.172 and in section 3, “Definitions,” of AMCA 214-21. In cases where there is a conflict, the definitions in § 431.172 take precedence over AMCA 214-21.

2.1. General.

This section describes the test procedure for fans and blowers other than air circulating fans. In cases where there is a conflict, the provisions in this appendix take precedence over AMCA 214-21. Where AMCA 214-21 refers to Annex A, “Polyphase Regulated Motor Efficiencies (Normative),” of AMCA 214-21, Table 5 of § 431.25 or the currently applicable standards in § 431.25 must be used instead.

2.2.1. General.

The fan electrical power (FEPact) in kilowatts must be determined at every duty point specified by the manufacturer in accordance with one of the test methods listed in table 1, and the following sections of AMCA 214-21: Section 2, “References (Normative)”; Section 7, “Testing,” including the provisions of AMCA 210-16 and ISO 5801:2017 as referenced by Section 7 and implicated by sections 2.2.2 and 2.2.3 of this appendix; Section 8.1, “Laboratory Measurement Only” (as applicable); and Annex J, “Other data and calculations to be retained.”

Testing must be performed in accordance with the required test configuration listed in Table 7.1 of AMCA 214-21. The following values must be determined in accordance with this appendix at each duty point specified by the manufacturer: fan airflow in cubic feet per minute; fan air density; fan total pressure in inches of water gauge for fans using a total pressure basis FEI in accordance with Table 7.1 of AMCA 214-21; fan static pressure in inches of water gauge for fans using a static pressure basis FEI in accordance with Table 7.1 of AMCA 214-21; fan speed in revolutions per minute; and fan shaft input power in horsepower for fans tested in accordance with sections 6.3 or 6.4 of AMCA 214-21.

In addition, if applying the equations in Section E.2 of Annex E of AMCA 214-21 for compressible flows, the compressibility coefficients must be included in the equations as applicable.

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

In cases where there is a conflict, the provisions in AMCA 214-21 take precedence over AMCA 210-16 and ISO 5801:2017. In addition, the provisions in this appendix apply.

2.2.2 Power Roof Ventilators

Centrifugal Power Roof Ventilators that are both supply and exhaust must be tested in both supply and exhaust configurations as listed in table 7.1 of AMCA 214-21.

2.2.3 Embedded Fans

Embedded fans that are not manufactured in a standalone configuration must be tested in a standalone configuration. If some components of the bare shaft fan are not removable without causing irreversible damage to the equipment into which the fan is embedded, testing must be performed using additional fan components, except for the fan impeller, that are geometrically identical to that of the fan embedded inside the larger piece of equipment for testing.

2.3. Power Supply

Any wire-to-air testing must be conducted at the supply frequency, phase, and voltages specified in this section. The frequency and voltage must be selected in accordance with section 7.8. of AMCA 214-21. Fans and blowers rated for operation for single- or multi-phase power supply must be tested with single- or multi-phase electricity, respectively. Fans and blowers, capable of operating with single- and multi-phase power supply, must be tested using multi-phase electricity.

2.4. Stability Conditions.

The following conditions must be met to establish system stability prior to collecting test data:

(a) Barometric pressure, dry bulb temperature and wet bulb temperature in the general test area must be captured at least every five seconds after the run-in period is completed and the ambient air density calculated from these values shall not vary by more than ±1 percent during verification of fan speed and fan input power stability.

(b) After the fan has been run-in, record the fan speed in rpm and the input power (in horsepower or watts) at least every 5 seconds for at least three 60-second intervals. Readings shall be made simultaneously. Repeat these measurements over 60-second intervals until:

(1) The average fan speed from the last 60-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 60-second test interval;

(2) The average input power from the last 60-second interval by reaction dynamometer, torque meter or calibrated motor must be ±4 percent, or the average input power by electrical meter must be ±2 percent of the mean or 1 watt, whichever is greater, compared to the average input power measured during the previous 60-second test interval; and

(3) The slopes of a linear fit trendline calculated from the individual data collected for fan speed and input power during at least three 60-second sampling 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 sampling intervals include both positive and negative values.

2.5. Sampling Intervals for Testing.

A test measurement must meet the following conditions:

(a) The sampling interval over which average test values are determined shall not exceed 60 seconds;

(b) The average fan speed from the most recent 60-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 60-second test interval; and

(c) the average input power from the last 60-second interval by reaction dynamometer, torque meter or calibrated motor must be ±4 percent, or the average input power by electrical meter must be ±2 percent of the mean or 1 watt, whichever is greater, compared to the average input power measured during the previous 60-second test interval.

2.6. FEI calculation

The FEI must be determined at every duty point in accordance with Section 4, “Calculation of the FEI for a single duty point,” and Section 5, “Reference Fan Electrical Power (FEPref)” of AMCA 214-21. In addition, the FEI must be rounded to the nearest hundredths place; FEP must be rounded to three significant figures; and all measurements must be recorded at the resolution of the test instrument.

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.

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,”

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.

2.1. 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: