23 Fans and Blowers

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Sometimes called the air-handler unit or the blower, the fan is the device which drives the treated air throughout the building. Usually driven by a single-phase AC motor in smaller applications, and a three-phase motor in larger commercial or industrial applications.

There are two main categories of fans, each with their own advantages and applications: the axial fan, which draws air parallel to the rotating axis and the centrifugal fan, which draws air at a right angle to its rotating axis.