How to Size Evaporative Cooling

Evaporative coolers, also called swamp coolers, are used in hot, dry climates as a way to cool the home.

Evaporative coolers use water to cool hot, dry airEvaporative coolers use water to cool hot, dry air
These coolers can use up to 75 percent less energy than air conditioners, making them more cost effective as a means of cooling your home. Evaporative coolers also are less expensive to purchase than an air conditioner, mainly because the technology is simple. With a few calculations you can determine the correct size evaporative cooler for your home.

Measure the length, width and height of each room you want to cool and record the measurements.

Multiply the length, width and ceiling height measurements of a room to get the cubic feet of the room. For example, a room measuring 12 by 12 feet with 10-foot ceilings would have a cubic foot measurement of 1,440.

Add the cubic foot measurements of all the rooms together to get a total cubic foot measurement of the area you want to cool.

Divide the total cubic foot measurement by two. The result is the amount of Cubic Feet per Minute (CFMs) that you want your evaporative cooler to be rated to cool the desired area effectively. For example, if your total cubic feet measurement was 15,000, you want an evaporative cooler rated at 7,500 CFMs or higher.

Things You Will Need

  • Measuring tape
  • Pen or pencil
  • Paper
  • Calculator (if desired)

About the Author

Jean Asta has been a freelance writer for domestic and international clients since 2005. She also acts as a training consultant to businesses and nonprofit organizations in the southeast United States. Asta holds a Master of Public Administration with a concentration in nonprofit management and a Bachelor of Arts in English literature, both from the University of Georgia.