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ASHRAE Standard 194-2025 Method of Test for Direct-Expansion Ground-Source Heat Pump, 2025
- ASHRAE Online Bookstore
- Addenda
- Errata
- ANSI/ASHRAE Standard 194-2025 [Go to Page]
- Contents
- Foreword
- 1. Purpose
- 2. Scope [Go to Page]
- 2.1 This standard provides test procedures for determining heating capacity, cooling capacity, coefficients of performance (COPs), and energy efficiency ratios (EERs) for systems, as defined in Section 3.
- 2.2 This standard applies only to electrically driven, mechanical vapor-compression refrigeration systems.
- 2.3 This standard applies to the testing of heat pumps with an outdoor refrigerant to test liquid heat exchanger utilized to condition the refrigerant entering the system under test. This standard does not apply to individual assemblies for separate use
- 3. Definitions and Symbols [Go to Page]
- 3.1 Definitions. All terms in this document shall follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilating, Air Conditioning and Refrigeration 1 unless otherwise defined in this section.
- 3.2 Nomenclature
- 4. Classifications [Go to Page]
- 4.1 Type 1—DX-to-Air Split System. Compressor and indoor coil are in separate cabinets. Indoor coil is with or without a fan (see Figure 1).
- 4.2 Type 2—DX-to-Air Packaged System. Compressor and indoor coil are in one cabinet, with or without a fan (see Figure 2).
- 4.3 Type 3—DX-to-Water Split System. Compressor and indoor water-to-refrigerant heat exchanger are in separate cabinets. Indoor heat exchanger is with or without a pump (see Figure 3).
- 4.4 Type 4—DX-to-Water Packaged System. Includes compressor and indoor water-to-refrigerant heat exchanger in one cabinet. Indoor heat exchanger is with or without a pump (see Figure 4).
- 5. Test Requirements [Go to Page]
- 5.1 Test Methods. All tests shall be conducted in accordance with ANSI/ASHRAE Standard 37, Methods of Testing Electrically Driven Unitary Air Conditioning and Heat Pump Equipment 2, and with the test methods and procedures described in Section 6.1. O...
- 6. Method of Testing and Calculations [Go to Page]
- 6.1 General. Testing and calculations shall be performed in accordance with the following standards:
- 6.2 Equipment Installation
- 6.3 Cooling and Heating Capacity Tests and Calculations for DX-to-Air (Types 1 and 2) Heat Pumps
- 6.4 Cooling and Heating Capacity Tests and Calculations for DX-to-Water (Types 3 and 4) Heat Pumps
- 6.5 Coefficient of Performance and Energy Efficiency Ratio Calculations
- 6.6 Operating Requirement—Maximum Operating Conditions Test. DX-GSHPs shall be designed and produced to pass the following maximum operating conditions test with (a) an indoor-side coil air quantity, as determined under Section 5.1.9 for DX-to-air ...
- 6.7 Operating Requirement—Low-Temperature Start and Operating Test. DX-GSHPs shall be designed and produced to pass the following low-temperature start and operating test in cooling and heating with indoor air quantities, as determined in Section 5...
- 6.8 Operating Requirement—Insulation Effectiveness Test. DX-GSHPs shall be designed and produced to pass the following insulation effectiveness test when operating in cooling mode with (a) air quantities for DX-to-air (Types 1 and 2), as determined...
- 7. Measurements [Go to Page]
- 7.1 General. Instruments required for the following measurements shall have the accuracy noted in Table 6. Instruments shall be calibrated at least once per year and a record shall be kept, including (a) date of calibration, (b) method of calibration...
- 8. Reference Properties and Data [Go to Page]
- 8.1 Thermodynamic Properties of Air
- 8.2 Thermodynamic Properties of Liquids
- 8.3 Thermodynamic Properties of Refrigerants
- 8.4 Thermodynamic Properties of Methanol
- 9. References
- 10. Informative Bibliography
- Normative Appendix A: Commissioning, Setup, and Start-Up Procedure for Testing Samples [Go to Page]
- A1. Setup
- A2. Airflow—Constant Torque Fan Motors
- A3. Airflow—Constant CFM Fan Motors
- A4. Variable Speed/Electronically Driven Compressor Products
- A5. Fan Power Correction Factor
- A6. Test Liquids
- Normative Appendix B: Determination of Airflow Rate and External Static Pressure for DX-to-Air Ducted Samples [Go to Page]
- B1. Required Indoor Fan Setup Information [Go to Page]
- B1.1 Constant Torque and Constant Airflow Motor-Type Fans. For test samples with electronically commutated motor (ECM) fans, the manufacturer shall provide to the laboratory all instructions required to install the equipment and reach the stated stan...
- B1.2 Permanent Split Capacitor Motor-Type (PSC) Fans. For test samples with PSC fans, the manufacturer shall provide to the laboratory all instructions required to install the heat pump and reach the rated standard airflow. The manufacturer shall als...
- B2. standard Airflow and ESP Requirements [Go to Page]
- B2.1 Standard airflow and ESP shall not exceed the tolerances specified in Table B-1.
- B2.2 Minimum ESP for ducted ECM blower-type samples are shown in Table B-2.
- B3. Setup and Start-Up Procedure
- Blank Page [Go to Page]
