Evaporative cooling is the process of cooling an area through the evaporation of water. They are also referred to as swamp coolers and are extremely efficient, especially in low-humidity areas. They supply a steady stream of fresh air into a home, rather than recirculating the same air.
Evaporative coolers pull cool outdoor air into a home and pass the air over water-saturated pads, causing the water to evaporate into the air. Once the air is saturated with cool water, it is directed to a home and pushes warm out through open windows.
An evaporative cooler is sized based on the cubic feet per minute (cfm) of air that is moved into a house. The normal range for models is from 3,000 to 25,000 cfm. Depending on the climate, it is recommended that you have enough air moving capacity to handle between 20 to 40 air changes per hour.
Evaporative coolers cost about half as much as central air conditioners and can be installed two ways. The first way is to install the evaporative cooler in a central location. Typically, this method of installation is best for compact houses. The second installation method is connecting the cooler directly to your ductwork, which is suggested for larger homes.
You can install the coolers on a roof using down-flow evaporative cooling, or you can install smaller coolers for horizontal-flow. There are even small, portable coolers that have wheels but they have a limited cooling ability due to indoor humidity.
For the best performance from an evaporative cooler, you should drain and clean it regularly. The cooler pad will develop a buildup of minerals and sediment, reducing its ability to evaporate water into the outside air. Routine maintenance from a professional might also be needed during the cooling season.
In hotter climates, you should check the pads, reservoir, filter, and pump at least once a month. The more a cooler runs, the dirtier it becomes, and more maintenance is required. You should consider replacing the cooling pads at least twice during the hot season or once a month if it’s used continuously.
The pads vary on how they can be cleaned. Some are made of paper and synthetic material and only have to be washed with soap and water. A weak acid can also be used on these, but you should check the manufacturer’s instructions first before using anything. When the pads are changed, you should clean the filters but disconnect the power to the unit first.