The U.S. government requires an efficiency rating of all air conditioning heating equipment, and for most household appliances. The rating reflects the percentage of energy used efficiently, with a higher rating indicating higher efficiency.
There are special names for the efficiency ratings of various types of equipment. Air conditioning equipment is rated by the Seasonal Energy Efficiency Rating, or SEER. The higher the SEER rating,the more efficient the equipment is. New equipment manufactured today by the manufacturers must meet at least a 13.0 SEER rating, with some manufacturers producing equipment as high as 21.0 SEER.
Depending on your system, it should be serviced a minimum of once a year, with periodic inspections up to 2 times a year