Evaporative Cooler Sizing

To get the best results from your evaporative cooler, make sure it is the correct size for your space. For example, an evaporative water cooler that is too small for your area will have to work extra hard to keep the space cool, wasting energy. The cubic feet per minute (CFM) is the amount of fresh air cycled through your environment each minute. To find the CFM, follow this formula:

For example, you’ll need the volume of the area and the recommended number of air exchanges per hour (typically two air changes per hour).

For example, if your living room is 420 square feet with 8-foot ceilings:

420 square feet x 8-foot ceiling = 3,360 cubic feet

3,360 cubic feet x 2 air changes per hour = 6,720

6,720 / 60 minutes = 112 CFM

According to the equation, you would need a swamp cooler with at least 112 cubic feet per minute CFM for the size of your living room.