Fan blades are designed to facilitate the movement of air in confined spaces and extreme temperature environments and can be used for both heating and cooling purposes. The blades are tilted to maximise airflow in any direction depending on the pitch of the blades and can often provide a reversible flow.
Fan blades, also known as impeller blades, are blades that are integral to an impeller (a rotor used to increase the pressure and flow of a fluid). An impeller is a rotating component of a centrifugal (uncentered) pump that works by transferring energy from the fan motor to the fluid that is being pumped by the accelerating blades. Impellers are usually short cylinders with an open inlet (called an eye) to accept incoming fluid.
Fan blades are typically made out of cast stainless steel but can be found in a range of materials such as metal alloys, aluminium and plastic. In many cases, the blades have five propellers which allow them to have maximum rotation effect to transfer energy efficiently.