Centrifugal Fan

A centrifugal fan is a pump or motor that pulls the air inside the blower and then pushes it out at a 90º angle. There are two key components of a centrifugal fan: the motor and the impeller. While the motor acts as propeller that pulls the air, impeller sucks and pulls the air. A centrifugal fan is a mechanical device for pushing air or other gases in a direction at an angle to the incoming fluid. They contain a ducted housing to direct outgoing air in a specific direction or across a heat sink.

Construction of Centrifugal Fan:

The centrifugal fan contains housing impellers, inlet and outlet ducts, drive shaft, drive mechanism, fan blades, fan dampers and vanes and fan discharging casing. This fan consists of an impeller in a casing with a spirally-shaped contour. What happens is that the air enters the impeller in an axial direction and is discharged at the impeller outer periphery. Hence, the air flow moves along the centrifugal direction. Such fans rely on blades to drag air into a circular motion with centrifugal forces and then speeds up airflow.

Working Mechanism of Centrifugal Fan

Different types of fans have been manufactured for different sets of uses whether in office setting or household premises. Centrifugal fans are known for moving the air radially, which means the direction of the outward flowing air is changed normally by 90° from the direction of the incoming air. Since the airflow created by centrifugal fans is directed through a system of ducts they create high pressure airflow.

Types of Centrifugal Fans

There are five different types of centrifugal fans and all differ on the basis of the type and shape of the fan blades. The five centrifugal fans are: backward curved blades, backward inclined blades, backward inclined aerofoil blades, radial blades and forward curved blades.

Use of Centrifugal Fan:

A centrifugal fan is commonly used for residential or official applications for moving the air through a duct in homes and offices. When we consider air conditioning system, furnace, or range hood duct, these are used in commercial settings such as car washing. Since centrifugal fans use the kinetic energy of the impellers to push the air flow, they turn against the resistance caused by ducts and dampers.