Meaning of energy efficiency ratio

en'ergy effi"ciency ra"tio

Pronunciation: [key]
  1. a measure of the efficiency of a heating or cooling system, as a heat pump or air conditioner, equal to the ratio of the output in B.T.U./hour to the input in watts:EER A high-efficiency home window air conditioner has an energy efficiency ratio of 7.5 or more. Abbr.:
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.