Designed and built with powerful fan wheels than axial flow fans. Centrifugal
flow fans operate at extremely high pressure but with lesser volume displacement
compared to axial flow fans. Three basic fan wheels: the forward curved, backward
curved, and the radial wheel make up the family of the centrifugal flow fans.
Forward curved fans -- centrifugal flow fans with blades pointing in the
direction of the fan rotation. Due to the large volume and high pressure
delivery of forward curved fans, this type is very compact and operated at
low speed that renders quiet operation. Typical application is in heating and
air-conditioning, ventilation, and other operation requiring quiet operation with
large volume of air to be moved at high pressure.
Backward curved fans -- centrifugal flow fans with blades pointing away
from the direction of wheel rotation. This type of fan wheel have to be operated
at very high speed in order to match the volume and pressure delivery of the
forward curved fans equaling in size. The main advantage the backward curve fan
can offer is its non-overloading characteristics.
Radial fans -- with the same size as the forward and backward curved fans,
the radial fans develop the least volume; pressure is higher than the backward
curved but lower than the forward curved fans. This type of fan find wide use in
industrial and commercial application.