What Is a Centrifugal Fan?

by | Sep 7, 2020 | HVAC Contractor

Before we talk about centrifugal fans, it is important to understand what centrifugal force is. Centrifugal force is the force that pulls a rotating body away from the primary center at which it is rotating. The ostensible force is caused due to the inertia of the rotating body itself. Centrifugal force is all around us. The force is felt when your car takes a sharp turn around a bend- you can feel a force pushing you towards the outer corner of the bend. If there is something on the passenger seat, you will see that it slides across over to the edge of the seat as the car takes a turn.

Understanding the Centrifugal Fan

A centrifugal fan follows a similar concept. It is a mechanical device that is used for “blowing” gases or air from one room to another. Many HVAC contractors refer to them as “blowers” because that’s the essential purpose of the fan. A centrifugal fan increases the speed of air that travels through its impellers (which are constantly rotating). The kinetic energy produced by the impellers of the fan is used to increase the air pressure in the fan. This allows the air to overcome the resistance created by ducts, ventilation shafts or other components, and flow freely. A centrifugal fan is very different from a conventional exhaust fan.

For instance, exhaust fans do not generate as much energy as a centrifugal fan. While exhaust fans are used to suck the air/ gases out of one room and let them out in an open environment, centrifugal fans are used to suck air/ gases from one room and provide it with the kinetic energy to travel over large distances through ducts and ventilation shafts. These fans have a very sturdy built, and are generally quite reliable. Because of their robust design, a centrifugal fan can be installed in a wide variety of conditions.


These fans are used in a number of different applications. For instance, small sized fans are installed in hair driers. They suck air from the atmosphere in the drier, where it is heated up via coils. The fan propels the air forward at fast speeds. The hand driers installed in washrooms are also fitted with these fans.

Similarly, large scale centrifugal fans are used in industrial environments. Large scale industrial corporations install these fans in environments to maintain air and gas flow in their warehouses and testing labs. These fans are also used in many car engines, since they work better in manipulating the air pressure as compared to axial fans. In large buildings, several HVAC applications also use these fans to manage the flow and pressure of air throughout the building.

Latest Articles