Energy Efficient Air Conditioning

The best ways to reduce air conditioning costs are to keep your home from heating up in the first place and to operate an energy efficient air conditioner. Start by using low-cost cooling measures like window shading. Close your shades in the morning to limit window solar gain during the day. Exterior fabric sunscreens can also slow solar gain, and are inexpensive and easy to install. If everyone leaves during the day, turn the air conditioner thermostat up to save energy, or install a programmable thermostat that will adjust the temperature while your gone.You’ll also improve the efficiency of your central air conditioner by maintaining the proper refrigerant charge. This is a job for professionals.

Air-conditioner efficiency depends upon routine maintenance. The difference between the energy consumption of a well-maintained air-conditioning system and a severely neglected system ranges from 10 to 40 percent.

Clean or replace indoor filters every 1 to 4 months. These are located in either the furnace/air handler cabinet, or at a central return air grille.
Clean the indoor evaporator coil and condensate pan every 2 to 4 years. Straighten any bent fins to improve airflow.
Clean room supply and return registers. Straighten their fins.
Remove plant matter and debris from around outdoor condenser.
Clean outdoor condenser coils every few years to remove dirt and pollen that robs efficiency. Straighten any bent fins.

For more information on air conditioning see Homeowners Guide to Building Performance, Your Home Cooling Energy Guide, Chapter 8 of Residential Energy: Cost Savings and Comfort for Existing Buildings or for specific information about servicing air conditioners for energy efficiency, see Saturn Mechanical Systems Field Guide.