HP - Motor Pully Diameter Calculations

You're thinking backwards. Think of it this way: at its max RPM, the air pump will deliver max CFM but will take max horsepower. If you want the pump to run quieter and with longer life at the expense of delivered air, you can decrease the size of the motor pulley, thus slowing the pump. This will require less horsepower, so you might want to downsize the motor as well.

Run the air pump slower, sure it "takes less effort" because it's doing less work.

Air pump speed (with a given driven pulley) is proportional to the size of the motor pulley diameter. Cut the diameter from 5" to 3" and you can go from 5hp to

If you have a "real" compressor (Quincy, Ingersoll Rand..) you can call the company and talk to someone with smarts and experience who can tell you right out what you want to know.

Grant

GT---

You might get a little insight into the effect of changing motor HP and pulley diameters by looking at a Grainger catalog. Find the pages where they advertise the air pumps. They show the effects of changing HP.

Jerry