Definitions for "Energy Efficiency Ratio"
Keywords:  btu, eer, watt, btuh, ari
EER): The ratio of cooling capacity of an air conditioning unit in British thermal units per hour to the total electrical input in watts under specified test conditions.
An efficiency rating system for air conditioning units that corresponds to the number of BTU's output per watt of electricity used.
A ratio calculated by dividing the cooling capacity in BTU's per hour (BTUH) by the power input in watts at any given set of rating conditions, expressed in BTUH per watt (BTUh/watt). EER & SEER can not be compared equally. Air source equipment is rated by SEER and geothermal equipment is rated by EER. EER changes with the inside and outside conditions, falling as the temperature difference between inside and outside gets larger.