What Is A Centrifugal Fan? – Complete Guide

A centrifugal fan is one of the most efficient fans on the market today. Most people think of a centrifugal fan as just a fan; its intricacies are not exactly common knowledge.

This complete guide will tell you everything you need to know about centrifugal fans. You might be wondering ‘What is a centrifugal fan? What are centrifugal fans used for? What are the different types of fans?

We will answer these questions and more. We’ll also highlight several useful videos from HVAC experts who break down these concepts in great detail.

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.

As shown in the video below, 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

Know the Working of an Axial Fan

Across industries, there are various machines and devices both electrical and electronic, which are designed for 24/7 working. As a result, they heat up, and if this exceeds the limits set, the device may be damaged which will result in halted production. To avoid machine failure due to excess heat, AC or DC industrial fans are used. There are various types of fans such as centrifugal, axial, and so on. An axial fan is a type of industrial fan which helps cooling of machines and devices. They facilitate parallel air flow to the rotor shaft, which offers ventilation to the device and prevents overheating. This post discusses the working and uses of AC and DC axial fans.

How Does an Axial Fan Work?

The industrial fan is chosen based on the direction of the air flow. an axial fan comprises a rotator shaft, blades, impeller, and a housing mostly made of steel. There is an air inlet through which the air enters inside once the rotator shaft rotates. The air flows parallel to the rotor shaft in a linear manner. This increases the flow rate and can gush in and out huge volumes of air. This can be achieved keeping both the pressure and power consumption low. The air enters the impeller in an axial direction. To raise the flow rate, the blades push the impeller and further deflect the flow of air into the guide vane. The air flow from the guide vane again becomes axial and enters the diffuser tube. The kinetic energy of the moving blades is converted into pressure which facilitates the required amount of ventilation. The blades of the axial fan are fixed but can be adjusted in terms of spacing and angle which helps achieve the required flow rate.

The shape of the blades to some extent also affects the speed of air flow. In axial fans, these blades may be tilted forward, backward, or could be curved. The number of blades may vary from 2 to 20, and the power or motor capacity required to drive operate these fans depends on the number of blades, speed and volume of air flow, and other application requirements. These fans produce pressure difference and force to facilitate the flow of air through them. Depending on the power supply and the application size, you could choose either a DC axial fan or AC axial fan.