Blower Horsepower Calculator

Diameter of Wheel (inches)
Width of Wheel (inches)      
RPM of Wheel                  

Air Velocity = feet per minute
Cubic Foot per Minute =
Inches Water Column =
Horsepower Necessary =
Here's the Blower Calc If you play with it it shows some neat trends. One to try is a 12" x 3" fan at 2825 RPM. Power required increases to the cube of rpm! As an example, double the RPM. The volume and pressure will also double, the required power will go up 8 times. Triple the RPM and the power requirement will go up 27 times. Spinning the wheel faster is the worst way to pick up volume or pressure. Instead plug in a larger wheel diameter and get the cfm to where that high speed cfm was. The power requirement went way down and the inches water column went up, a better pulling fan. Now take the diameter back down , keep the rpm down and get the cfm by making the wheel deeper. The power required is the lowest and the water column drops, the volume increases, the most efficient air mover. For sucking dust ...a not so fast fan, a relatively large diameter wheel in relation to depth. Air velocity should be 3500 feet per minute or more. Water column for a small shop should be above 5".

The Math Behind The Calculator