The bottom of a 5 volt, 0.6 amp laptop cooling fan/blower.
The bottom of a Forcecon clockwise brushless laptop cooling fan (blower). Camera: Samsung WB30F.

Blowers, otherwise known as centrifugal fans or squirrel cage fans are devices that draw air through enclosures. Common applications for blowers include:

  • Laptops.
  • All-in-one PCs (example: iMac).
  • Rack servers.
  • Forcing air through the heating element in a rework station.
  • Certain video cards.
Blower/Centrifugal Fan
Two blowers/centrifugal fans. These fans spin air out from the center and push it out through a duct (sometimes a duct, at least). They generate additional pressure to force air through constricted areas.

The primary purpose of a blower is to generate a higher pressure than a conventional axial fan. This enables it to force air through constricted areas such as laptops or anything generating large amounts of heat. Axial fans are low-pressure fans, therefore they cannot force air through such devices effectively. Blowers are also ideal for HEPA filtration systems for PCs and air purifiers.

An axial fan requires a significant amount of space in front of its intake and exhaust in order to function currently. Laptops don’t have that.

Axial fan
Axial fan. The back of a 120 volt, 0.12 amp (120 mA), 14 watt, alternating current cooling fan. Image Credit: Kompulsa.

Cooling Raspberry Pi Single-Board Computers (SBCs)

A Raspberry Pi or similar device can be cooled with either an axial fan or a blower. This is dependent on the type of case you’ll install it in. For example: A Raspberry Pi 3 in its official case only needs a tiny axial fan and heat sink to keep cool.

If you were to squeeze a Raspberry Pi 3 or Raspberry Pi 4 into a thin case with a screen or filtration system, it would benefit from a blower.

Axial fans have benefits over blowers such as lower noise levels and efficiency. This is because of the additional power required to generate a blower’s higher pressure. Axial fans are often cheaper and easier to clean than blowers.