SEER is an acronym for Seasonal Energy Efficiency Rating which is an efficiency rating of an air conditioning system. It is a ratio of the annual BTU's of cooling provided divided by the electric energy input used, and is measured over a range of temperatures.
As of January, 2006 central air conditioner systems must be manufactured to a minimum 13 SEER although you may still buy older units having a lower SEER (lower efficiency) rating. SEER ratings go as high as 21. The higher the SEER rating the larger the physical size of the outside air conditioner condensing unit.


