Coefficient of Performance (COP)

By Anne Fonda

The coefficient of performance (COP) is an air conditioning and heat pump efficiency metric.  A unit’s coefficient of performance is a ratio of useful heating or cooling provided relative to the energy consumed at a specific temperature. A higher COP means higher heating efficiency, lower energy consumption, and potentially lower operating costs.

This is in contrast to a heat pump system’s heating seasonal performance factor (HSPF2), which measures the unit’s heating efficiency across a range of temperatures during the entire heating season.

Heat pump COP usually exceeds 1, because instead of just converting fuel burned to heat (which, if 100% efficient, would be a COP of 1), it transfers heat. Less work is required to move heat than to convert fuel to heat.

To qualify for heat pump rebates and tax credits, a heat pump must have a COP of at least 1.75, along with meeting other energy efficiency metrics as displayed in the table below.

American Standard high-efficiency heat pumps are tested and verified by an independent third party (AHRI) to have a coefficient of performance (COP) at 5°F typically ranging from 1.8 to 2.5, indicating that for each unit of energy consumed, they can deliver as much as two and a half times more heating energy than energy used. 

The specific COP for a heat pump model will vary depending on factors like the number of tons, number of heating and cooling stages (single-stage vs two-stage vs variable speed), paired indoor unit, operating conditions (especially outdoor temperature), and the set temperature.

COP can be used for cooling efficiency as well, but it’s just not as common. A unit’s seasonal energy efficiency ratio (SEER2) and energy efficiency ratio (EER2) are more commonly used to assess an air conditioner or heat pump's cooling efficiency over the entire season (SEER2) and cooling efficiency at a specific temperature (EER2).  

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Anne Fonda, Content Writer

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need. 

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Chelsea Hudson, Product Manager, Ducted Variable Speed Outdoor