Evaporative air coolers are a great supplement to air conditioning or alternative to a fan. While a fan simply pushes hot air around, an air cooler adds moisture to the air which makes the air feel cooler. They provide air circulation and don't require an exhaust hose, making them portable and easy to move from room-to-room. In addition to cooling temperatures, portable air coolers also work as a humidifier by adding moisture to the air in a room, making them perfect for homes with dry heat.
Air coolers are often called evaporative cooler or swamp coolers and there are three main types- the smaller personal-sized air cooler, the larger home or room sized models, and the even larger industrial sized models. The industrial sized models are often used in warehouses and you may have seen them on the sidelines at professional football games. The larger home or room sized models are common in the hot, dry climate of the American Southwest, and they often require that windows be left open to expel hot, dry air as the units operate. The personal models are usually designed for indoor use, to boost the cooling in areas that are not cooled well. This article focuses mainly on personal air coolers, although the larger versions work on the same principles.
Swamp Coolers Have a Few Main Parts:
- The water tank holds water to be used in the cooling process
- The wick absorbs water from the water tank and allows it to evaporate when air is blown over it
- The fan blows air over the wick and the water held in the wick
To operate an air cooler, you must first fill the water tank with water. The bottom of the wick is immersed in the water and it "sucks" water from the tank and pulls up into itself. A fan is located behind the wick. It blows air over the wick and out of the machine into your room. As the air is blown over the wick, the water in the wick evaporates. Evaporation is an endothermic reaction- it absorbs heat- so the air that is blown over the wick and out into your room has had some of the heat absorbed out of it. Of course, the water that evaporated and absorbed heat from the air is carried out into your room as water vapor.
Air coolers work best in dry climates, and they are not very effective in climates with a high humidity, since they relay on water evaporating to produce cooling. Also, you should note that they do humidify the air, and as such are never a good option for cooling servers or electrical equipment.
It is important to note that these air coolers are different than other air conditioners. Often confused, evaporative coolers do not have a compressor, refrigerant or sealed system, therefore will not be a suitable replacement for an air conditioner. A better way to envision them is as souped-up fans- they will cool the air they (by up to 12°F), but they will not cool a room. If you are looking for an air conditioning unit, we would suggest looking for a portable, window or ductless unit.