Fan Types and Selection Guide

This document explains the two basic types of air moving devices—centrifugal fans (including forward-curved and backward-inclined designs) and axial flow fans (propeller, tube-axial, and vane-axial)—detailing their performance characteristics, efficiency ranges, and applications. It also covers fundamental fan operation principles, including the relationship between horsepower, speed (cube law), and pressure, as well as the distinction between overloading and non-overloading fan types.