Types of Fans

Axial and propeller fans, centrifugal (radial) fans, mixed flow fans and cross flow fans

Axial and Propeller Fans

axial fan

In axial fans the air flows in parallel to the shaft. It is common to classify axial fans upon their wheel:

C-wheel - Blades can be adjusted when running. High efficiency, small dimensions, variable air volume
A-wheel - Blades can be adjusted when fan standing still. High efficiency, small dimensions, adaptive to recommended air volume
K-wheel - Blades can not be adjusted. Simple, small dimensions

The pressure head developed for single stage is up to 300 N/m². Axial fans are suited for relatively large volumes compared to pressure.

axial fan

Centrifugal fans (Radial fans)

centrifugal fan

In a centrifugal fan the air flows is in a radial direction relative to the shaft. Centrifugal fans can be classified by their wheel:

F-wheel - Curved forward blades. High efficiency, small dimensions, changing in pressure have little influence on pressure head.
B-wheel - Curved backward blades. High efficiency, low energy consumption, changing in pressure have little influence on air volume. Low noise emission, stable in parallel running.
P-wheel - Straight backward blades. High efficiency, self cleaning, changing in pressure have little influence on air volume
T-wheel - Straight radial blades. Self cleaning. Suitable for material transport

Types of blade used in centrifugal fans:

Straight steel plate paddle wheel
Forward multivane multiblade
Backward turbovane

The different blades can be characterized as shown in the capacity diagram below:

centrifugal fan

Mixed flow fans

In a mixed flow fan the air flows in a combined axial and radial direction relative to the shaft. A mixed flow fan develops higher pressures than an axial fan.

Cross-flow fans

In a cross flow fan the air flows in an inward direction and then in an outward radial direction.

ToolBox ShortList

Difficult to find your favorite ToolBox page? Add a link to the page in your own personal Shortlist!

• Add this Page! • Delete the ShortList!

Translate this page to Spanish French German Italian Dutch Norwegian

The content in The HVAC ToolBox is copyrighted but can be used with NO WARRANTY or LIABILITY. Important information should always be double checked with alternative sources. All applicable national and local regulations and practices concerning this aspects must be strictly followed and adhered to.

We appreciate any comments and tips on how to make The HVAC ToolBox a better information source. Please contact us by email if You find any faults, inaccurate, or otherwise unacceptable information.

5 12 1