Axial fans are very popular in the ventilation industry. They are used for Heating, Ventilating and Air Conditioning applications and for industrial process applications as well. Axial fans can be used in exhaust or supply arrangement. The airflow enters and leaves the fan in an axial direction.
The cylindrical shape housing and the inlet and outlet flanges make these fans suitable for limited space installation. On similar capacities, axial fans are more compact in size compared to centrifugal fans, and they are generally noisier than in-line centrifugal fans. Axial fans also have lower pressure range than centrifugal fans.
There are three types of axial fans: Propeller fans, Tubeaxial fans and Vaneaxail fans.
Wall mounted propeller fans are commonly used for general ventilation. They are used in commercial applications such as parking garages, warehouses and for industrial applications such as process plants, and manufacturing facilities. Propeller fans are designed to move air at low pressure.
Tubeaxial fans and Vaneaxial fans are often used for ducted applications. They are used in commercial applications such as general ventilation systems and for industrial applications such as fume exhaust systems. The Tubeaxial fans are designed to move air at low to moderate pressure, up to 2 inch water column, while the Vaneaxial fans are designed to move air at high pressure, up to 8 inch water column. The downstream guide vanes provide a good air distribution on downstream side of the Vaneaxial fan. Cast Aluminum blades with aerofoil cross section are commonly used in these types of fans to improve the fan efficiency.
The blades are attached to the hub. The blades often have adjustable pitch angle that can be pre-set at the factory to adjust the performance of the fan and avoid wasting energy.