Measure of cooling efficiency seasonally.

In the United States, the efficiency of air conditioners is often rated by the seasonal energy efficiency ratio which is defined by the Air Conditioning, Heating, and Refrigeration Institute, a trade association, in its 2008 standard AHRI 210/240, Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment.

based on the weight gain of a test subject divided by its intake of a particular food protein during the test period.

In Europe, the seasonal efficiency of refrigeration equipment, chillers and air conditioners is often rated by the European seasonal energy efficiency ratio which is controlled (among others) by the Eurovent Certification Company.