An evaporative cooler is a device that cools air through the evaporation of water. It is also known as an evaporative air conditioner, swamp cooler, swamp box, desert cooler, and wet air cooler. Evaporative cooling is the conversion of liquid water into vapor using the thermal energy in the air, resulting in a lower air temperature. Evaporative coolers lower the temperature of air using the principle of evaporative cooling, unlike typical air conditioning systems which use vapor-compression refrigeration or absorption refrigeration.
Evaporative coolers are commonly used in areas with low humidity, where evaporating water into the air provides a natural and energy-efficient means of cooling. They are rated by the cubic feet per minute (cfm) of air that they deliver to the house, with most models ranging from 3,000 to 25,000 cfm. Evaporative coolers can be installed in one of two ways: the cooler blows air into a central location, or the cooler connects to ductwork, which distributes the air to different rooms. Small horizontal-flow coolers are installed in windows to cool a room or section of a home, while room evaporative coolers are becoming more popular in areas of the western United States with milder summer weather.
Evaporative coolers work by reducing the nearby air temperature using evaporated water. The unit includes a fan, water tank, and internal motor, which passes dry air through a wet, internal filter pad. The air is quickly cooled and circulated throughout the room, and opening nearby windows helps renew the air every few minutes and keeps the breeze fresh. An evaporative cooler should have at least two speeds and a vent-only option, which lets you use the evaporative cooler as a whole-house fan in a residential application.
Evaporative cooling systems require fewer materials to operate, typically only water and electricity, and they require less maintenance than air conditioners. They are more eco-friendly and efficient in energy consumption than AC and are also more powerful than normal fans. Evaporative coolers are suitable for dryer climates and are widely used in the West.
