What they are & How they work
SWAMP COOLERS 101
Evaporative (or “swamp”) coolers are the most economical method of cooling a house in a dry climate. The electricity is used to run a large fan and a water pump.
Swamp Cooler – diagram 1 |
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The cooler sits on the roof, with an air duct leading down into the house. The cooler is essentially a large box, four sides of which are removeable panels. These panels have vents in them to let air flow through. On the inside of each panel is attached a “cooler pad” which looks a little bit like a matt of hay. The pads are about 2-3 inches thick and about 3 feet square. They are made of a material which absorbes water.
Swamp Cooler – diagram 2 |
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At the bottom of the box is a reservoir of water [3], with a tube running down into it. At the top is the other end of the tube, with a “spider” attachment of hoses. These spread across the top of the box to the sides. The ends of the hoses are above the top edges of the pads. A pump runs a continuous trickle of water over the pads, keeping them wet. The water runs through them and collects again in the reservoir.
At the entrance to the duct is a large fan [5] which sucks hot air from the outside [1] in through the wet pads [2], where they are cooled by evaporation [4]. The air is then blown down into the house [6].
Although the cost is much less than running air conditioning, there are drawbacks to using an evaporative cooler. The primary failing these coolers have is they are dependant on dry air. In the desert this is usually not a problem…until it rains. IF it rains, the cooler will just blow hot, wet air into the house. If it stays humid for a day or longer, the pads will start to smell bad, and that odor is also blown into the house. Unfortunately, the rainiest time of year in Arizona happens to also be the two hottest months: July and August. These months are notoriously miserable for swamp cooler users.
Other failures include clogged water lines, broken pumps, and mineral-clogged pads. Any of these will cause the cooler to not work.
diagrams © OpalCat 1996
— 07:17:04 AM
[12415]
07/06/2007 10:19 PM Reply
I am an architect and sustainable building design teacher. I want to teach my students about evaporative coolers because they make so much sense. Your images and “video” make the evaporative cooler so easy to understand. Would you be willing to let me use those for my classes? Thank you for your consideration. Vanessa Blair Seibert, AIA, LEED AP
07/07/2007 01:12 AM Reply
Yes, you may use them for your class. I’d appreciate it if you said you got them at opalcat.com. Thanks!
02/23/2008 05:32 AM Reply
Hello, we would like to know if you could help us with an idea to build a working model of an evaporative cooler for a science project. Thanks
04/24/2008 01:38 PM Reply
Would you be interested in having this illustration featured in a book on greenhouses?