Tips for Lowering Your Central Air Conditioner's Energy Usage Tips for Lowering Your Central Air Conditioner's Energy Usage
Set your thermostat at 78 F or higher. Each degree setting below 78 F will increase energy consumption by approximately 8%. Be careful, however, that if you're A/C is oversized the diminished run-time from raising the thermostat setting may result in too-high indoor humidity in some locations.
Use bath and kitchen fans sparingly when the air conditioner is operating to avoid pulling warm, moist air into your home.
Inspect and clean both the indoor and outdoor coils. The indoor coil in your air conditioner acts as a magnet for dust because it is constantly wetted during the cooling season. Dirt build-up on the indoor coil is the single most common cause of poor efficiency. The outdoor coil must also be checked periodically for dirt build-up and cleaned if necessary.
Check the refrigerant charge. The circulating fluid in your air conditioner is a special refrigerant gas that is put in when the system is installed. If the system is overcharged or undercharged with refrigerant, it will not work properly. You will need a service contractor to check the fluid and adjust it appropriately.
Reduce the cooling load by using cost-effective conservation measures. For example, effectively shade east and west windows. When possible, delay heat-generating activities, such as cooking and dishwashing, until evening on hot days.
Over most of the cooling season, keep the house closed tight during the day. Don't let in unwanted heat and humidity. Ventilate at night either naturally or with fans.