SEER is an abbreviation for seasonal energy efficiency rating and refers to the ratio of how much cooling is provided by an air conditioner compared with wattage used. Units with higher SEER ratings generally use less electricity and provide higher cost saving over their lifetimes.
Central air conditioning units and heat pumps manufactured in the United States after Jan. 23, 2006, must have a SEER rating of at least 13. Prior to this standard, the minimum SEER rating in the United States was 10. A central air conditioning or heat pump unit with a SEER 13 rating has a 30 percent increase in energy efficiency compared with a SEER 10 unit.