Seasonal Energy Efficiency Ration (SEER) basically indicates the amount of energy needed to provide a specific cooling output. Older systems typically have SEER ratings of 6 or lower, the minimum SEER allowed today is 13. When you are in the market for a new AC Unit look for the ENERGY STAR label for air conditioners with SEER ratings of 13 or greater, but also consider using air conditioning equipment with higher SEER ratings for even greater savings..
Air Conditioners manufactured after January 26, 2006 must achieve a SEER rating of 13 or higher. To break that down a little bit, an Air Conditioner that has a SEER rating of 13 is 30% more efficient than that of a SEER 10. Any Equipment that was manufactured before January 26, 2006 and has a rating lower than SEER 13 may still be sold and installed, you should always ask about the SEER rating before you make your purchase. The average “lifespan” of a central air conditioner is about 15 to 20 years, even though you are not required to change out for a more efficient unit, the benefits of faster and more efficient cooling and a less expensive electric bill quickly overcomes the upfront cost.