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ASHRAE Standard 40-2014 (RA2024) -- Methods of Testing for Rating Heat-Operated Unitary Air-Conditioning and Heat-Pump Equipment (ANSI Approved), 2014
- ASHRAE Online Bookstore
- Addenda
- Errata
- ANSI/ASHRAE Standard 40-2014 (RA2024) [Go to Page]
- Contents
- Foreword
- 1. Purpose [Go to Page]
- 1.1 This standard provides test methods for determining the heating and cooling output capacities and energy inputs of unitary air-conditioning and heat pump equipment that is heat-operated (see Section 3, “Definitions”).
- 1.2 These test methods may be used as a basis for rating such equipment, but it is not the purpose of this standard to specify methods of establishing ratings.
- 2. Scope [Go to Page]
- 2.1 This standard applies to heat-operated unitary air conditioners and heat pumps consisting of one or more assemblies, including engine-driven systems. Where such equipment is provided in more than one assembly, the separate assemblies are designed...
- 2.2 Equipment within the scope of this standard may be classified as follows:
- 2.3 This standard does not include methods of testing the following types of equipment:
- 3. Definitions
- 4. Method for Using This Standard [Go to Page]
- 4.1 Test Conditions. The method provided in this standard may be used to determine equipment cooling capacity, heating capacity, and energy inputs at various test conditions that may be prescribed in other standards or specifications and shall includ...
- 4.2 Variation of Test Conditions. In all cases, the test conditions during the prescribed test period shall be maintained within the tolerances specified in Section 13.5.
- 5. Test Methods [Go to Page]
- 5.1 Standard Test Methods Covered in this Standard
- 5.2 Applicability of Test Methods
- 5.3 Measured Energy Input Parameters
- 6. Air-Enthalpy Test Method [Go to Page]
- 6.1 General Description
- 6.2 Test Room Requirements. The test room or rooms shall meet the requirements prescribed in Sections 13.1.1, 13.1.2, 13.1.3, and 13.1.4, as applicable.
- 6.3 Airflow and Airflow Measurements. The airflow-measuring device shall be in accordance with the provisions of Section 10.
- 6.4 External Resistance Measurement. External resistance shall be measured in accordance with the provisions of Section 11. Connections to equipment outlets shall comply with the provisions of Section 11.
- 6.5 Temperature Measurement
- 6.6 Calculations ,
- 7. Heat Balance Method [Go to Page]
- 7.1 General Description. In this method, capacity is determined by algebraically combining the results of measurements of energy input, heat rejection, jacket losses, and flue gas or exhaust losses, where applicable.
- 7.2 Capacity Calculations
- 7.3 Heat Rejection (qr) to Heat Sink in Cooling Mode
- 7.4 Heat Absorption (qa) from Heat Source in Heating Mode
- 7.5 Jacket Heat Loss (qj). This quantity represents the amount of heat loss by radiation, conduction, and convection from parts of the equipment to ambient not otherwise included in the heat-transfer terms itemized above.
- 7.6 Heat Loss in Flue Gas of Fuel-Operated Equipment (qf). This quantity represents the residual heat in the products of combustion that were not absorbed by the refrigerating system. This quantity is determined from measurement of flue gas temperatu...
- 7.7 Energy Input
- 8. Coolant Heat-Transfer Fluid Flow Method [Go to Page]
- 8.1 General Description. In this method, capacity is determined from measurements of the coolant heat- transfer fluid temperatures and flow rates.
- 8.2 Coolant Heat-Transfer Fluid Flow Measurement. The coolant heat-transfer fluid flow rate shall be measured with any suitable flow or volume meter having an accuracy as specified in Section 12.5.
- 8.3 Temperature Measurement. Coolant heat-transfer fluid temperatures shall be measured with any suitable temperature-measuring instruments located at the connections to and from the appropriate equipment sections. Measurements shall be made to withi...
- 8.4 Calculations
- 9. Refrigerant Enthalpy Method [Go to Page]
- 9.1 General Description
- 9.2 Refrigerant Flow Measurement
- 9.3 Refrigerant Temperature and Pressure Measurement
- 9.4 Refrigerant Enthalpy Method Calculations—Cooling Capacity
- 9.5 Refrigerant Enthalpy Method Calculations—Heating Capacity
- 10. Airflow Measurement [Go to Page]
- 10.1 Airflow Measurement. For equipment having a rated cooling capacity less than 40 kW (135,000 Btu/ h), airflow rates shall be measured by the nozzle described in Section 10.2. Larger equipment may use this method or the alternative methods provide...
- 10.2 Nozzle Apparatus
- 10.3 Nozzles
- 10.4 Calculations
- 11. Pressure (External Resistance) Measurement [Go to Page]
- 11.1 Indoor Section-Side Duct Connections
- 11.2 Practices for Pressure Measurements
- 12. Instruments [Go to Page]
- 12.1 Temperature-Measuring Instruments
- 12.2 Pressure-Measuring Instruments for Refrigerant, Coolant, and Barometric Pressure Measurements
- 12.3 Airflow and Differential Pressure Measurements
- 12.4 Energy Instruments
- 12.5 Fluid Flow Measurement
- 12.6 Speed-Measuring Instruments. Speed measurements shall be made to an accuracy of ±1.0% of the reading.
- 12.7 Time and Mass Measurements
- 12.8 Refrigerant Mass Composition. Refrigerant mass composition measurements for zeotropic refrigerants shall be made in accordance with Reference 2 (AHRI Standard 700, Specifications for Fluorocarbons and Other Refrigerants).
- 13. Test Preparation And Performance [Go to Page]
- 13.1 Test Room Requirements
- 13.2 Equipment Installation
- 13.3 Test Operating Procedure
- 13.4 Data to Be Recorded. Table 13.4 shows, generally, the data to be recorded during a test. Items indicated by an “X” under the test method columns, or their equivalent, are required when that test method is used.
- 13.5 Test Tolerances
- 14. Test Results [Go to Page]
- 14.1 Capacity Test Requirements
- 14.2 Reference Properties and Data. Air and refrigerant properties data shall be taken from the latest applicable Handbook of ASHRAE.
- 14.3 Capacity under Cycling Conditions
- 15. Nomenclature
- 16. References and Bibliography
- Informative Appendix A: Environmental Chamber Design Considerations for Testing Heat-Actuated Cooling Equipment [Go to Page]
- A1. General Observations
- A2. Chamber Conditions Uniformity
- A3. Test Equipment Handling [Go to Page]
- A3.1 Design Chambers with “High” Ceilings. Generally, chambers are built from modular standard panels and come with standard 1.75 m or 2.5 m (6 ft or 8 ft) ceilings. At least a 3 m (10 ft) ceiling is recommended. This feature will greatly facilit...
- A3.2 Design the Chamber(s) with a Floor That Will Allow One to Move in “Heavy” (up to 450 kg [1000 lb]) Test Units. The chamber floors should be able to support a load brought into the chamber with a forklift truck. Ideally, the roof should have ...
- A4. Refrigerant Consideration
- A5. Combustion and Makeup Air Considerations
- A6. Combustion Vent Products Considerations
- A7. Environmental Chamber Control Systems
- A8. Safety Controls [Go to Page]