On most models, the air filter is easily accessible by removing the front panel. Remove the filter and clean it gently with a combination of warm water and dish soap or white vinegar. Let the filter air dry completely before reinstalling it. These should be cleaned once per month during the cooling season. If you have pets or allergies, consider cleaning it more frequently. If the filter has tears, holes or other damage, it should be replaced. If your unit has a foam filter, you can purchase replacement electrostatic filter material and cut it to accommodate the exact size of your model.
If you've left your air conditioner uncovered in your window or wall over the winter, you'll need to check for wasp and bees' nests inside of the unit. Avoid problems with this in the future by storing your window air conditioner in a protected area such as a basement or utility room during the off season. If you must leave your AC in the window, use an air conditioner cover.
Over time, dust and dirt will build up on the inside of the air conditioner's condenser coils. This build up will require your AC to work harder to remove heat – increasing energy consumption and your monthly electric bill.
At the start of every cooling season, clean the condenser coils. You'll need to remove the air conditioner cabinet completely in order to access the coils. They can be cleaned by blowing compressed air at them or by using a soft bristle brush and a spray bottle of household cleaner to wipe the dirt off.
Take great care in removing the dirt. If you accidentally bend or dent the aluminum coil fins, use a handy fin comb to straighten out the fins.
It is also important to remove dirt or lint build up at the bottom of the air conditioner so the condensate water will be picked up by the condensing fan blade slinger properly.
If the temperature outside the room where the air conditioner is placed becomes cool (approximately 60 degrees Fahrenheit or 15 degrees Celsius or lower), check the coils on the front of the air conditioner for icing. Ice buildup on coils means the temperature is too low for proper operation of the unit. You should use it only when the outdoor temperature rises above 60 degrees Fahrenheit or 15 degrees Celsius.