So, how do you determine the appropriate size of cooler, that can give you the best results? You need to calculate a simple figure called CFM (cubic feet per minute). For that, you will require the square feet area of the room, and height at which the ceiling is. You have to multiply the square footage by the height of the ceiling, and then divide by 2.
For Example: 500 × 8 ÷ 2 = 2,000 CFM