Chart below is a “Rule of Thumb” Guide Only Not a Substitute For an Engineered Calculation
When in doubt, always choose one size larger
- Consult zone map to find correct zone
- Consult table to find correct “minutes per air change” for your zone
- Determine area to be cooled in cubic feet (building length x width x height)
- Divide cubic feet (step 3) by minutes per air change (step 2) to determine CFM
- Select correct Champion Cooler model according to CFM and expected static pressure
If CFM falls between models, choose the larger model
Interior Heat Load:
High means places with unusual heat sources from hot equipment or processes, crowded conditions, etc.
Normal means no unusual heat sources – typical home or office.
Exterior Heat Load:
Exposed means walls, roof exposed to the sun, poor insulation, etc.
Insulated means walls and roof well insulated and/or shaded.
A house in Phoenix AZ, 40 feet long by 30 feet wide with an 8-foot ceiling. Insulated, no unusual heat sources.
30 x 40 x 8 = 9,600 cubic feet
Minutes per Air Change: 2
9,600 / 2 = 4,800 CFM
A 4800 CFM Cooler model is indicated.