Designed and built with higher pressure fan wheels than axial flow
fans. Centrifugal fans operate at elevated pressures but with lesser
air volume compared to axial flow fans. There are three basic fan
wheels: the forward curved, backward curved, and the radial blower
up the family of the centrifugal flow fans.
Forward curved centrifugal fans -
centrifugal fans with blades pointing in the direction of the fan
rotation. Due to the large volume and high pressure delivery of forward
curved fans, these fans are very compact and operate at low speed that
ensures quiet fan operation. Typical applications are: heating and
air-conditioning, ventilation, and other HVAC systems requiring quiet
operation with large volume of air to be moved at high pressures.
Backwardly curved centrifugal fans -
centrifugal flow fans with blades inclining backward from the direction
of wheel rotation. This type of fan wheel have to be operated at higher
speed in order to achieve the same volume and pressure as the forward
curved fans of the same size. The main advantage of the backwardly
curve fan is its non-overloading performance curve characteristics.
Radial blade fans - with the same wheel
diameter size as the forward and backwardly inclined fans, the radial
develop the least volume. Pressure is higher than the backward curved
lower than the forward curved fans. This type of fan find wide use in
pressure and high temperature industrial process applications.