Ventilation fans are designed for air supply, air extract or air supply and extract functions. Models are available for a host of applications in the residential, commercial (including IT and telecomms), and industrial sectors. They can be ceiling, duct, roof, wall or floor mounted.

Different types include:
- Centrifugal fans, which feature a fan wheel or impeller that moves the air. They are especially suitable for industrial applications, as well as heating and cooling systems.
- Axial fans, which feature blades that blow air through the axis of the fan, are commonly used in air conditioning and industrial applications, and are less noisy than centrifugal fans.
- Mixed flow fans, in which the air flows in an axial and radial direction relative to the shaft, generally develop higher pressures than axial fans.

Kitchen and bathroom extractor fans and ceiling fans are covered in separate sections on this website.