HOW TO SIZE A FAN TO YOUR SPACE

Properly sizing a fan to your specific room size and type is an important step in optimizing comfort and air exchanges in the space. This fan calculator is used to calculate the CFM or cubic feet per minute of air exchange that is required in a building. Whether exhausting air or bringing fresh air into a structure, this calculator should help to figure out the size of fan(s) required to accomplish the air exchanges needed. Consult local building codes for specific requirements pertaining to the suggested air changes for proper ventilation.

Step 1. Select "Minutes per Change" required for your space

If you are not sure how many Minutes per Change are needed for your type of facility, select your application type from the below list which shows typical Minutes per Change by room type.

TypicalRange
Assembly62-10
Auditoriums61-20
Bakeries21-3
Banks63-10
Bars42-5
Barns1510-20
Boiler Rooms21-3
Bowling Alley31-5
Cafeteria43-5
Churches62-10
Classrooms64-8
Compressor Rooms21-3
Dance Halls62-10
Dairies42-5
Dormitories64-8
Dry Cleaning Plant31-5
TypicalRange
Engine Rooms31-5
Factories74-10
Foundries52-8
Garages74-10
Generating Plants42-5
Glass Plants21-3
Gymnasiums62-10
Hallways84-12
Kitchens (Comm.)31-5
Laboratories31-5
Libraries42-5
Laundries21-3
Locker Rooms62-10
Machine Shops42-5
Markets62-10
Mills42-5
TypicalRange
Packing Houses43-5
Plants74-10
Plating Plants42-5
Print Shops74-10
Restaurants62-10
Rest Rooms74-10
Schools74-10
Spray/Paint booth11-2
Stores74-10
Theaters64-8
Transformer Rooms31-5
Turbine Rooms42-5
Waiting Rooms1210-15
Warehouses74-10
Welding Rooms31-4

Note: Extreme conditions may require “Minutes per Change” outside typical. Consider the geographic location and average duty level of the area. For hot climates and heavier-than-normal area usage, select a lower number in the range to change the air more quickly. For moderate climates with lighter usage, select a higher number in the range.

Step 2. Calculate room volume

Length (ft) Width (ft) Height (ft)
Minutes per Change Approximate CFMs Required Recommended Fans

Step 3: Purchase a fan that meets your needs

MODELVOLTSTYPESPEEDSMIN CFMMIDDLE CFMMAX CFMIMAGEPURCHASE
DFC-24D-S120VDrum Fan, 24" Direct Drive, Swivel253007300Buy Now
DFC-30D-S120VDrum Fan, 30" Direct Drive, Swivel265008800Buy Now
DFC-36D120VDrum Fan, 36" Direct Drive, Fixed2770011280Buy Now
DFC-42B120VDrum Fan, 42” Belt Drive, Fixed2980015800Buy Now
DFC-48B120VDrum Fan, 48” Belt Drive, Fixed21200017800Buy Now
WFO-24120V24" Commercial Outdoor Rated Oscillating Wall Mounted Air Circulator3490062007500Buy Now
WFO-30120V30" Commercial Outdoor Rated Oscillating Wall Mounted Air Circulator3530068008200Buy Now
PFO-24120V24" Commercial Outdoor Rated Oscillating Air Circulator w/Pedestal Base3490062007500Buy Now
PFO-30120V30" Commercial Outdoor Rated Oscillating Air Circulator w/Pedestal Base3530068008200Buy Now