Forward Curved Vs Backward Curved Centrifugal Fan

Pressure curve less steep than that of backward curved fans.

Forward curved vs backward curved centrifugal fan.

The modern forward curved blades are designed with a scroll housing. Do not rate fan in the pressure curve dip to the left of peak pressure. Backward curved centrifugal fans. The name centrifugal fan is derived from the direction of flow and how the air exits the fan impeller radially from the outer circumference of the fan.

With a backward curved impeller the air exits in a radial direction whereas with a forward curved the air exits tangentially from the circumference of the fan. On the other hand those with backward curved blades are basically free wheeling fans. 2 forward curved blades provide a low noise level comparitive to backward curved blades because backward curved blades have high speed relatively to forward curved blades for same capacity range. Power rises continually toward free delivery.

Forward curved centrifugal fans are more cost effective than backward curved centrifugal fans though and have become popular in industries like the medicinal industries since they don t accumulate chemicals and other debris on their blades. The difference is the length of impeller rail and the edge. This reduces the level of noise. The forward curved is parallel to the edge.

Backward inclined the performance of the backward inclined wheel is similar to the forward curve however bi fans tend to be non overloading meaning their fan curves do not tend to increase hp as static pressure changes but cfm falls off. The forward and backward curved centrifugal fan mainly refers to the different blades of their assembled. 1 forward curved blades curve in the direction of the fan wheel s rotation on the other hand backward curved blades curve against the direction of the fan wheel s rotation. A backward curved centrifugal fan is characterised by its cylindrical shape several large curved blades and a conical inlet nozzle.

Motor selection must take this into account. Another important design feature is the position of the motor. The difference in flow direction between a forward and backward curved centrifugal fan is the direction that the air exits the impeller circumference. The forward curved type is generally are blowers and the backward curved type are induced draft fans.

In most cases these fans are designed with external motors. Backward curved these wheels are extremely efficient more robustly built and very quiet.