3.4: Centrifugal Fan
Click play on the following audio player to listen along as you read this section.
Centrifugal fans are better suited to push larger volumes of air through ducting systems. They are designed to produce higher pressure for a given volume of air than an axial fan of the same horsepower rating. Any fan used to drive air throughout the system must produce enough total pressure to overcome the static pressure of the ducting system and drive air everywhere it is needed.
Drawing the intake air at 90 degrees relative to the outtake, the fan blades direct the air in an spinning, circular direction, accelerating it towards the exhaust vent.
Depending upon the application, the drive mechanism of the fan may be directly coupled, belt driven, or powered by a variable speed drive.
Centrifugal fans are noisier than an axial fan of equivalent horsepower, and so are often installed in areas where high noise levels are acceptable or noise dampening components can be installed.
Centrifugal fans can move large quantities of air, while overcoming all the resistive static pressure of the duct-work system.