Heat pump reference
Heat Pump Efficiency Ratings Reference
Use the correct metric for the question: point performance, cooling efficiency, or seasonal heating and cooling comparison.
Efficiency metric lookup
| Metric | Definition | Units | Use it for |
|---|---|---|---|
| COP | Useful heating or cooling effect divided by net work input, expressed in identical units. | Dimensionless | A documented point condition or measured interval. |
| EER | Average rate of space cooling delivered divided by average electrical energy consumed. | BTU/Wh | A stated cooling rating condition. |
| SEER2 | Seasonal cooling efficiency determined by the current prescribed test method. | Seasonal BTU/Wh rating | Comparing certified equipment; not a point COP. |
| HSPF2 | Total seasonal space heating required in the specified test climate divided by total electrical energy consumed. | Seasonal BTU/Wh rating | Comparing certified heating performance; not a point COP. |
Matched-condition conversion
COP = EER ÷ 3.412141633
This conversion is valid only when COP and EER describe the same cooling output and electrical input boundary at the same condition. It does not convert a seasonal rating to a point COP, or predict annual cost.
How to identify the right value
- State whether the question is heating or cooling and whether it concerns a moment, a measured interval, or a whole season.
- Keep load, equipment data, and runtime at the same operating condition.
- Use COP for the operating-cost calculator only when it comes from a matching condition.
- Keep SEER2 and HSPF2 as their certified seasonal ratings unless an official model provides the appropriate conversion method.
Example
A cooling COP of 3.00 at a given test point corresponds to EER 10.24 BTU/Wh at that same point (3.00 × 3.412141633). It does not mean the unit has a SEER2 of 10.24, because SEER2 is a seasonal test metric.
Limits and next steps
Efficiency labels do not establish whether the equipment has enough capacity at a design condition, whether an electrical circuit is adequate, or how a particular building will operate. Verify the system's certified combination and manufacturer performance data, then use an appropriate load calculation and qualified design process.
Related resources
- Heat Pump Operating Cost Calculator
- Heat Pump COP and Operating Cost Guide
- HVAC Load Calculator
- BTU Conversion Reference
Sources and scope
Definitions are summarized from DOE material. Rating metrics depend on equipment category and test procedure; use the governing program and manufacturer documentation for product decisions.