Difference Between Fan and Blower

Fan vs Blower

The fan is a mechanical device that is used to create a continuous flow of gas such as air. In any cooling system, which uses a gas as the working fluid, a fan is a compulsory unit which creates the flow of air through the system. It can be a simple ceiling fan used in households or an external cooling fan for internal combustion engines. When higher pressure is required blowers are used instead of fans.

More about Fan

The fan usually consists of assembly vanes or blades fixed onto a hub, usually called an impeller. A driver mechanism like a motor or a belt drive will be connected to create the rotational motion of the impeller. The mechanism can be arranged so that the flow is either centrifugal or axial.

Axial fans blow the gas along the axis of rotation, and they are commonly used as cooling fans in households, automobiles, and even in computers. Larger fan structures are used in turbojet engines, industrial air conditioning machines, and in wind tunnels, to provide the flow of large volumes of gas.

Centrifugal fans blow the gas radially outwards from the axis of the impeller. They are also known as Squirrel cage fans due similarity in appearance to the exercise cage used for pet squirrels. Gas sucked in from the cavity present in the centre of the impeller is driven outwards by the centrifugal force acting on the gas due to rotational motion. Centrifugal fans are the most commonly used type in the modern HVAC devices.

Compressor creates a flow of the gas with high pressure and low volume transfer rate, while fans deliver low pressure and high volume transfer rate.

More about Blower

A centrifugal fan with a high pressure ratio (output pressure/ input pressure) is known as a blower. Blowers deliver a high volume transfer rate with a relatively greater pressure ratio. The pressure ratio of a fan is below 1.1 while blowers have a pressure ration of 1.1 to 1.2.

What is the difference between Fan and Blower?

• Fans produce a gas flow with less pressure and larger gas volume, while blowers produce a relatively higher pressure ratio with the larger gas volume flow.