How to Determine if an Air Source Heat Pump Passes the APF Test?
In extreme climates like -25℃ in northern regions, determining the APF test pass rate for an air source heat pump hinges on confirming that the heat pump's APF value meets the corresponding energy efficiency rating requirements, based on national standards GB 21455-2019 and GB 19577-2024. This is further verified through multi-condition real-world testing to confirm its actual performance at low temperatures. Especially for industrial-grade heat pump projects, simply looking at the nominal value is insufficient to guarantee energy-saving effects; a comprehensive assessment must be made considering testing standards, measured data, and compatibility with local operating conditions.
1. Three Core Standards for Qualification Assessment
1) Air Source Heat Pump APF Value Meets National Energy Efficiency Standard Threshold
According to GB 19577-2024 "Energy Efficiency Limits and Energy Efficiency Grades for Heat Pumps and Chillers", the APF qualification thresholds for different categories of heat pumps are as follows:
* Residential Air Source Heat Pumps: APF ≥ 3.6, APF ≥ 3.0
* Multi-split Heat Pumps (≤14kW): APF ≥ 5.2, APF ≥ 3.6
* Industrial Heat Pump Units: Evaluated according to HSPF or CSPF, but APF should be ≥ 3.0
* Conclusion: In northern regions, an APF ≥ 3.6 can be considered "high-efficiency qualified". A value below 3.0 indicates an inefficient air source heat pump, not recommended for long-term operation projects.
2) Testing Based on Current National Standards
Passing tests must be performed based on the following standards:
* GB 21455-2019: Energy Efficiency Standard for Room Air Conditioners, applicable to household and small commercial heat pumps
* GB 19577-2024: Integrates multiple old standards, becoming the only authoritative standard currently available
* GB/T 7725-2022: Updates test methods, improving the standardization of APF calculations
* Key Point: Check whether the air source heat pump test report specifies "based on GB 19577-2024" or "GB 21455-2019"; otherwise, the data is invalid.
3) Testing Covers Real-World Low-Temperature Conditions A qualified APF test for an air source heat pump must cover multiple low-temperature points during the heating season, especially in extremely cold regions like northern China:
* Must include four heating conditions: 7℃, 2℃, -7℃, and -15℃.
* Ideally, it should be extended to -25℃ for actual testing to verify the low-temperature degradation rate.
* In the weighting allocation, heating performance should account for no less than 60%.
* Beware of misrepresentation: If the report only tests and calculates the APF under the 7℃ condition, but actually relies on electric auxiliary heating at -25℃, the energy efficiency of the air source heat pump will be severely reduced.
2. How to identify a truly qualified air source heat pump APF test on-site?
1) Energy Efficiency Label: Heat pumps display the "China Energy Efficiency Label," with a rating of Level 1 or 2, adhering to the standard GB 19577-2024. No label, ambiguous rating, or adherence to an older standard (e.g., GB 37480).
2) Measured APF Value: Air source heat pumps clearly indicate a specific value (e.g., APF=4.0), not vague statements like "higher than national standard." Only "Level 1 Energy Efficiency" is stated without a specific value.
3) Low-Temperature Performance Parameters: Data on COP≥1.8 and heating capacity reduction≤30% at -25℃ is provided. No low-temperature data is provided, or it is labeled "dependent on electric auxiliary heating."
4) Testing Institution Qualification: Reports are issued by CMA/CNAS certified institutions (e.g., CVC, TÜV SÜD). No official seal, no qualification number, or self-compiled report.
5) Test Completeness: Includes additional tests such as standby power consumption, partial load, and wide voltage operation. Only nominal operating condition data is provided.
* Recommended Actions: Request a complete PDF test report from the air source heat pump supplier, paying particular attention to the "Test Conditions," "Test Result Summary Table," and "Conclusion Page."
3. Verification Recommendations for Northern Regions
1) Strong winter winds and sandstorms: Fin blockage → decreased heat exchange efficiency → reduced actual APF. Choose a design with stainless steel fins and dust filters, and regularly clean and maintain the heat pump.
2) Drastic day-night temperature differences (up to 20℃): Frequent start-ups and shutdowns → increased energy consumption → lower actual energy efficiency. Use AI self-learning inverter control to reduce ineffective operation of the air source heat pump.
3) Frequent voltage fluctuations (165–265V): Control failure → operation interruption → affecting energy efficiency statistics. Prioritize wide-voltage electronic control systems.
4) Continuous industrial heating demands: Long-term operation tests the stability of the air source heat pump system. Verify whether it has passed the 72-hour full-load aging test.
* Special Reminder: When applying for government energy-saving subsidies for air source heat pumps, a CMA-certified APF test report must be provided; otherwise, acceptance will not be successful.
