Fan Velocity Calculator, Formula, Fan Velocity Calculation

Fan Velocity Calculator:

Enter the values of Rated Cubic Feet Per Minute of the Fan CFM(ft3/m) &  Diameter of the Fan D(inches) to determine the value of Fan Velocity Vfan(ft/s) .

 Enter Rated Cubic Feet Per Minute of the Fan: ft3/m Enter Diameter of the Fan: inches Result – Fan Velocity: ft/s

Fan Velocity Formula:

The Fan Velocity Vfan(ft/s) in feet per second is equal to the Rated Cubic feet per minute of the fan CFM(ft3/m) in Cubic feet per minute Divided by the 3.141 value to multiply the Diameter of the Fan D(inches) in inches is divided by the value of 12 is squared and again divided by the 4 and divided by 60times.

The Formula of Fan Velocity can be writtern as,

Vfan(ft/s) = CFM(ft3/m) / ( pi * ( D(inches) /12 )2 /4 ) / 60

Here,

Vfan(ft/s) = Fan Velocity in feet per second

CFM(ft3/m) = Rated Cubic feet per minute of the fan in Cubic feet per minute

D(inches) = Diameter of the Fan in inches

Example problems for Fan Velocity:

1)Calculate the Fan Velocity and given for CFM = 400 , Diameter of the Fan = 10inches.

Vfan = CFM / ( pi * ( D / 12 )2 / 4 ) / 60

Vfan = 400 / ( 3.141 * ( 10 /12 )2 / 4 ) / 60

Vfan = 12.22ft/s.

2)Calculate the Diameter of the Fan and given for CFM = 400 , Fan Velocity = 12.22ft/s.