Centrifugal Blower Fan

The low pressure area at the center of the fan creates a vacuum that draws air into the fan.

Centrifugal blower fan.

Direct drive fans have fewer moving parts than belt drive fans for less maintenance. Centrifugal fans and blowers typically have one of eight types of wheels that draw the air into the inlet of the blower housing through the wheel and discharges it at 90 degrees out through the discharge of the housing. Such a fan is also called a blower fan biscuit blower or squirrel cage fan because it looks like a hamster wheel. Equipment cooling blowers create a more concentrated stream of air than equipment cooling fans to blow away the heat generated by electronic equipment induction heaters and high wattage bulbs.

Centrifugal fans often contain a ducted housing to direct outgoing air in a specific direction or across a heat sink. It also adds kinetic energy to the air. How a centrifugal fan works the rotating fan blade creates a low pressure area at the center of the blade and a high pressure area at the edges of the blade. The two most common types of centrifugal blowers are pressure blowers and volume blowers.

The scroll housing in a centrifugal fan accelerates the air and changes the direction of the airflow twice a full 90 degree before leaving the housing. In addition to material handling applications centrifugal air blowers are popular for the hvac industry and air pollution control systems.