The Department of Energy has tightened regulations for the energy usage of new central air conditioning units. The DOE rates the efficiency of units using the Seasonal Energy Efficiency Ratio. Units manufactured after Jan. 23, 2006 must have a SEER of 13 or higher.
When DOE tightened standards in 2006 and increased the minimum SEER from 10 to 13, it estimated the change would yield potential annual energy savings equal to the total electricity 26 million households consume. Units with higher SEER ratings use less electricity than those with lower ratings.
Annual costs to run central air conditioners depend on the unit's size, its SEER rating and the rate charged by the power company. For example, if you pay 16 cents per kilowatt-hour for electricity, a SEER 14, 3-ton air conditioner unit system might cost $414 to operate annually, depending on your climate and how often you run the system.
Using an air conditioner with a SEER rating of 16 represents savings over using a SEER 14. The annual electricity cost for operating a SEER 16, 3-ton unit at the same 16 cents per kwh is $360, or $54 less than with the SEER 14 unit.