A squirrel cage fan is a centrifugal fan which allows the movement of air or other types of gases out of a specific area or building…

A squirrel cage fan  is a centrifugal fan which allows the movement of air or other types of gases out of a specific area or building.  The design is called a squirrel cage fan due to the fact that it looks decidedly like a hamster wheel and consists of a fan wheel with a number of fan blades or ribs which are mounted around a central hub.

How They Work?

These devices work in a very similar manner to an exhaust fan, but differ in one crutial aspect, the outflow of air is directed 90 degrees to the inflow which makes it far more versatile than a standard exhaust fan.  In addition, this change of direction results in increased acceleration and pressurization as a result of centrifugal forces, which makes it ideal for central heating and cooling systems as well as air polution control.

Greenhouse and Grow Room Use

In Greenhouses and grow rooms, ventilation is critical in ensuring that plants remain healthy.  Without good air ventilation your plants will become exposed to high temperatures as well as incorrect levels of CO2.  Squirrel fans are considered the best option for these although, other centrifugal fans, whisper fans and inline fans can also achieve excellent results.

Wheel and Airflow Ratios

Squirrel cages also have a range of different wheel designs with the F-wheel which comprises of curved forward blades while the T-wheel has straight radial blades.  B-wheels ave backward curved blades and P-wheels have straight backward blades.  Each of these blade types have a different level of air flow output with forward blades offering the highest level and backward the least.  Radial blades offer a moderate to high flow.

Various Other Uses

While the housings may contain filters as well as heating and cooling elements, the design of the squirrel cage fan is ideal for industrial systems and air pollution.  They can also be found outside the home in airplanes, cars and dehumidifiers.