| Parameter | Value | Note |
|---|
COP and what it means for Canadian HVAC efficiency
COP (Coefficient of Performance) is the most fundamental efficiency metric for any refrigeration or heat pump system. It's the ratio of useful energy output to energy input. A COP of 3.0 means you get 3 units of heating or cooling energy for every 1 unit of electrical energy consumed. An electric resistance heater has a COP of exactly 1.0 — heat pumps almost always beat that, which is why they're the preferred heating solution in Canada's net-zero energy strategy.
COP changes with operating conditions. A heat pump that achieves COP 3.5 at 8°C outdoor ambient might drop to COP 1.8 at -15°C. This is why Canadian cold-climate heat pump ratings matter — HSPF2 (Heating Seasonal Performance Factor 2) gives a more realistic seasonal average that accounts for the full Canadian heating season including extreme cold.
COP vs. EER vs. SEER vs. HSPF2
EER is COP multiplied by 3.412. It measures cooling efficiency in BTU/watt-hour at a single test condition (95°F outdoor, 80°F / 67°F indoor wet-bulb). SEER averages EER across a range of conditions representing a full cooling season. HSPF measures heating efficiency across the full heating season. HSPF2 uses a revised test procedure introduced in 2023 that better reflects real-world field performance — HSPF2 values are typically 15% lower than HSPF for the same equipment.
NRCan minimum efficiency standards for Canada require SEER2 of 14.5 for split AC systems and HSPF2 of 7.1 for heat pumps as of 2023. Energy Star Canada requires SEER2 of 16 or higher and HSPF2 of 9.5 or higher for heat pump certification. Use this calculator to convert any nameplate rating to COP for direct comparison between different efficiency metrics and system types.
Carnot COP: the theoretical limit
The Carnot COP is the theoretical maximum efficiency any heat pump or refrigeration system can achieve between 2 temperature reservoirs. Real systems achieve 40-70% of Carnot COP due to irreversibilities in compression, heat exchange, and refrigerant flow. For an air conditioner with a 40°F saturated suction temperature and 110°F condensing temperature, the Carnot COP for cooling is 40+460 divided by (110-40) = 500/70 = 7.14. A real system achieving COP 3.5 at those conditions is operating at 49% of Carnot — typical for a high-efficiency residential unit. Use the P-T chart calculator to find the saturation temperatures for your Carnot COP inputs.
Frequently Asked Questions
At 8.3°C (47°F) outdoor ambient, a standard air-source heat pump should achieve a heating COP of 2.5 to 3.5. Cold-climate heat pumps rated for -25°C operation achieve COP of 1.5 to 2.2 at -15°C outdoor temperature. NRCan's Energy Star threshold requires a minimum HSPF2 of 9.5 for split systems, corresponding to a seasonal average COP of roughly 2.8. Ground-source heat pumps typically achieve COP of 3.0 to 5.0 year-round. If your measured COP is significantly below these ranges, check refrigerant charge with the superheat calculator and airflow across both coils before concluding the equipment is underperforming.
Divide EER by 3.412 to get COP. EER is in BTU per watt-hour; dividing by 3.412 converts to the dimensionless COP ratio. For example, EER 12 divided by 3.412 equals COP 3.52. To convert SEER to approximate seasonal COP, also divide by 3.412. A SEER 16 unit has an approximate seasonal COP of 4.69. Use the Convert mode above to do these conversions instantly, including HSPF2 to COP for heat pumps.