What exactly is SEER?
The cooling efficiency of a heat pump or an air conditioning system is rated by the Seasonal Energy Efficiency Ratio (SEER). The SEER is defined as a ratio of the average amount of cooling per unit of electricity used. Federal regulation mandates a minimum SEER 13.0 for most residential air conditioners manufactured after January 23, 2006. Efficiencies of some systems can be as high as SEER 17.0 or more. (Chances are that older homes have units with SEERs less than 10.) Note that it is important to understand that even though the SEER may be high, if the system is inefficient (for example, leaky ductwork), you will not receive the full value of the efficiency as the air distribution system is not used to determine the SEER rating.