If your air conditioning system is not cooling you down, take a look at these quick recommendations. They may save you a lot of time and money. Follow-up by having a competent licensed air conditioner contractor inspect and evaluate the system if necessary.

Testing Your Central Air System

· To test the air conditioning, the outside temperature should be above 60° for 48 hours (some manufacturers recommend 65°). If you turn the air conditioning system on when the temperature is below 60°, you may damage the compressor.

· Turn the fan switch to "auto" and set the thermostat below the room temperature (76° to 78° is recommended). The fan and condensing unit should come on, unless there is a time delay, which may slow its start.

· Let the system run for eight to ten minutes to balance the temperature in the ductwork. Check the temperature at the supply and return registers. The temperature at the supply register should be 14° to 20° Fahrenheit cooler than at the return ducts or current room temperature.

* If the temperature differential is more than 20°, it indicates restricted air. This points to three possible problems: 1) a dirty filter, 2) improper ductwork, or 3) a fan that is sized wrong, not working properly, or moving too slowly.

· If it is less than 14° differential, the possible causes are 1) refrigerant loss, 2) a dirty coil, 3) a laboring compressor, 4) an oversized fan, or 5) a deficient return air system.

· There are two copper lines going from the condensing unit on the exterior to the air handler on the interior. The smaller line is the liquid or high-pressure line and will be warm, not hot, to the touch when it is operating properly. The larger line covered with insulation is the suction or low pressure line and will be cold to the touch. The suction line should be "sweating" or condensing, the way a glass of iced tea "sweats." It should not be forming "ice."

Two Common Central Air Conditioning Problems

The refrigerant in the system may be low from a possible leak. The leak should be located, repaired, and recharged.

Compressor failure is a problem, which usually requires replacement of the unit. Usually when a compressor is replaced, the entire condensing unit on the exterior is replaced. The typical life expectancy of a compressor in a central air conditioning system is 8 to15 years, depending on geographic location.

Air Conditioning Unit Efficiencies

When discussing air conditioning system efficiencies, the SEER number is the typical guideline, and the higher the SEER number, the more efficient the unit (E.g., a 12 SEER unit is 20% more efficient than a 10 SEER unit). This information can be a considerable help when evaluating the cost versus the value of a new system.