A- In theory you could save anywhere from 10% to 60% depending on which model you purchase, how efficient your old A/C was and how much you use the A/C. It’s is assumed that because the new unit is more efficient, you will save on your power bill. However you may not save anything and in some cases, the new more efficient unit may cost more money to operate. Poor installation practices, defective ductwork and or damaged ductwork could be robbing you of your intended saving. New equipment installation should be followed by testing of the performance of the duct system.