The higher the Seer rating the more efficient the unit and the less electricity the unit uses. Older homes that are 20-30 years old and have original units will most likely have a unit with a Seer rating of 8-10. While homes that are 15-20 years old have units with Seer ratings in the 10-15 range. Newer homes that were recently built should have a seer rating between 13-16.

Mini splits are typically more energy efficient than even the best central A/C units and are becoming more popular. They have Higher-SEER ratings than air conditioners and are zone specific which can result in significantly lower utility bills..