Fan Configurations

The three essential fan configurations are ducted fan, forcing fan, and exhausting fan.

Ducted Fan

The fan has both inlet and outlet ducts.



The dynamic pressure is non-zero at both the inlet and outlet.

In this configuration, the fan static pressure is:

p f , S = p f , T - p f , D


=
                  pt,2-pt,1-(pt,2-ps,2)
              

=
                   p s , 2 - p t , 1
              

Forcing Fan

The fan upstream is a plenum and the downstream is a duct.



The dynamic pressure is zero at the upstream, but non-zero at the downstream.

In this configuration, the fan static pressure is:

p f , S = p f , T - p f , D


=
                  pt,2-pt,1-(pt,2-ps,2)
              

=
                   p s , 2 - p t , 1
              


= p s , 2

Exhausting Fan

The fan upstream is a duct and the downstream is a plenum.



The dynamic pressure is non-zero at the upstream, but zero at the downstream.

In this configuration, the fan static pressure is:

p f , S = p f , T - p f , D


=
                  pt,2-pt,1-(pt,2-ps,2)
              

=
                   p s , 2 - p t , 1
              


= - p t , 1