Centrifugal Fan
A centrifugal fan or centrifugal blower is a pump or motor that moves air. It pulls the air inside the blower and then pushes it out at a 90º angle. The two main components of a centrifugal fan are the motor and the impeller. An impeller sucks or pulls air, in contrast to a propeller which pushes air. Some fans can pull and push air at lower than a 90º angle; these fans are called mixed flow fans. Centrifugal fans can either have no exterior housing or structure to offer protection or they can be built with some protective housing.
There are five different types of centrifugal fans, which differ based on the type and shape of the fan blades:
- Backward curved blades
- Backward inclined blades
- Backward inclined aerofoil blades
- Radial blades
- Forward curved blades
Each blade type varies in terms of efficiency – in other words, how fast the fan moves air through the duct or system where it’s installed. The most important thing to know is that backward curved blades are the most efficient, whereas forward curved blades are one of the least efficient types of fans.