If you happen to live in a hot, dry part of the world, an evaporative air conditioner could be just the ticket for inexpensive cooling of your home. Also known as a "swamp cooler," an evaporative air conditioner works by blowing air over a wet absorbent pad. The pad is kept wet by means of a water pump. The wet air is up to 20 degrees cooler than other air in the room.

Swamp coolers differ from standard air conditioners in that there is no refrigeration unit, which means they are much more economical to run. That also means you can have a window or door open for fresh air.

In fact, you need to have a window open at least a little bit in order to let air flow in and out of the room. If you don't have a window open, humidity will build up inside the house and the evaporative air conditioner will not work as well as it could.

Maintenance Tips

In the spring, you will want to take some time for routine maintenance of your evaporative air conditioner. First open the unit up and clean out the water pan at the bottom. Check the pan for rust and for leaks.

Fix any splits in the casement that could cause water leaks. Oil the motor and check the tension of the belt. It should give about a half inch. Replace the cooler pads with new ones. A good quality of pad to use are those made from aspen wood fibers.

Connect the water and turn it on. Check and adjust the float valve as needed. This is done by bending the arm a little. Turn on the pump and the motor and see if the pads are being evenly saturated with water.

In the middle of the summer, check everything out to make sure it is working properly. See how much debris is collecting on the cooler pads. The less there is, the better the unit is working.

At the end of the season, get the evaporative air conditioner ready for the winter. Clean out the pan and dissolve any deposits with vinegar. Clean the tray and coat it with an anti-rust agent. Make sure everything is dried completely before bedding it down for the winter. Disconnect the water line and cover the unit well.

Tips for Saving on Operating Costs

Whenever you turn on the unit, turn the pump on for a few minutes before turning on the fan. This way the pad will already be saturated with water and the air will come out cool right from the start.

Ceiling fans will be a big help in moving around the cool air and will make your home more comfortable. You can also save big by waiting until the outdoor temperature is over 85 degrees before you turn the unit on at all.

At night, just as standard air conditioners can be run simply on "fan" when the night is cool, you can turn the pump off and run the swamp cooler just as a fan. The night air tends to be cool enough most nights, especially in the dry climates suited to the use of a swamp cooler.

Another tip for making the cooler work better is to keep the water filter clean. If it gets clogged up with debris or lime it will cause the whole unit to work less efficiently.