By Steve Graham, Networx
Swamp coolers are commonly, and perhaps more appropriately, known as evaporative coolers. A swamp cooler can make a hot, desert house more comfortable. Swamp coolers are an effective and energy-efficient alternative to traditional air conditioners for low-humidity climates.
Evaporative coolers combine a fan with the power of evaporative cooling. They pull in dry air and dampen it through a wet pad, then blow the wetter air into the home. As the moisture evaporates, the air temperature can drop by as much as 30 degrees. Moreover, as with other fans, the blowing air can make the air feel another six degrees cooler. Itís the same principle as feeling cooler as sweat evaporates from your body.
Both individual single-room swamp coolers and central systems are available, and are fairly inexpensive (though newer units pre-cool the air and cost roughly as much as central air conditioners).
To determine the size of a swamp cooler, calculate the volume of space you need to cool and cut the number in half. The resulting number is the ideal value of the swamp cooler, which are measured and rated in cubic feet per minute (cfm), or the cubic feet of cool air blown into the home per minute. For example, a 100-square-foot room with 8-foot ceilings has 800 cubic feet of space to cool, so would require a 400 cfm swamp cooler.
There are several advantages of swamp coolers over air conditioners, but a couple of significant drawbacks.