As can be seen from the above figure, at the same fan speed S, the outlet air velocity V of the forward inclined fan will be much higher than that of the rear inclined one

fan, so if the same air volume and pressure need to be generated, the backward inclined fan needs to be used at a higher speed, or increased

Fan size. Thus small size, low speed and low noise are the advantages of forward tilting over backward tilting, but backward tilting fans are efficiently

The rate is much higher than that of the forward-sloping fan, which is much more energy efficient.

Formula for the pressure obtained by the fan: Pt = ρ[(C2²- C1²)/2+( U2²- U1²)/2+( W2²- W1²)/2]

Forward leaning fans benefit from the ease of obtaining higher pressures at the same speed, and therefore, ignoring efficiency, also use the

In some very small air volume, ultra-high pressure (very low efficiency) occasions.

In summary, backward inclined fans are suitable for relatively high pressure, low flow and high power, and forward inclined fans are suitable for

High air volume, low pressure, low power, or ultra-low air volume, high pressure conditions.