To reduce your electric bills it is wise to make sure your central air conditioner is running as efficiently as possible.
Because actual cooling costs depend on weather conditions, they can vary significantly from year to year, making accurate comparisons difficult.
The easiest way to determine the savings from installing a new central air conditioner is to compare the SEER (Seasonal Energy Efficiency Ratio) of your existing model to a new model. You can be pretty sure your existing unit is not operating more efficiently than when it was new, so the savings from this comparison will be on the conservative side.
There are things you can do yourself to keep your central air conditioner running as efficiently as possible. This does not preclude having regular professional service calls, though. Technicians have equipment and pressure gauges to check the internal components, which is impossible for homeowners to do on their own. Regular service calls can extend the life of a central air conditioner.
It helps to understand how an air conditioner works. It operates on a delicate balance of airflow rates over the indoor and outdoor coils and proper pressures of the refrigerant. The compressor compresses the refrigerant to make it very hot. This hot liquid is hotter than the outdoor air, so it loses heat to the outdoor air through the condenser coils.
The cooler refrigerant then goes through an evaporator, which makes it very cold. This is similar to how your skin cools off when perspiration evaporates. This cold refrigerant flows through the indoor coil. The blower moves indoor air over these cold coils, which cools your house air.
It can really help efficiency to make sure weeds and shrubs have not grown too close to the outdoor unit and impede airflow. Also, don’t rest rakes or other items against it, which might block airflow.
Check that all the screws holding the cabinet sections together are tight. If they are loose, tighten them; leaks will draw air in gaps instead of through the coils.
Annual filter change is a simple way to save
Even though everyone has heard to change the blower filter regularly, most people don’t do it. At the beginning of the cooling season, change the filter whether you think it is dirty or not. A dirty filter increases airflow resistance, which reduces efficiency. Check the joints in the ducts for any leaks. Seal them with aluminum tape or black Gorilla duct tape.