Performance characteristics of centrifugal fans

The centrifugal fan is essentially a variable flow constant pressure device. When the speed is constant, the pressure-flow theoretical curve of the centrifugal fan should be a straight line. Due to internal losses, the actual characteristic curve is curved. The pressure generated in the centrifugal fan is greatly affected by changes in the intake temperature or density. For a given intake volume, the pressure generated at the highest intake temperature (lowest air density) is the lowest. For a given pressure and flow characteristic curve, there is a power and flow characteristic curve. When the blower runs at a constant speed, for a given flow, the power required increases as the intake temperature decreases.