Evaporative coolers, unlike traditional air conditioners that use freon, do not use chemicals of any kind, so they are more eco-friendly. Additionally, evaporative coolers, also called swamp coolers, are less expensive to operate and install.
Evaporative coolers can reduce the air temperature by up to 20 degrees, and they work best in hot climates with low humidity. They are not effective in humid climates because the cooling system works by circulating air over water-moistened pads. To calculate the correct size evaporative cooler for a room, look for one with a cubic feet per minute that is half the cubic feet of the room.