In message , Tim Watts
writes
harry
wibbled on Friday 30 July 2010 07:44

There are lots of fans & ductwork in "Screwfix"catalogue.
You will need a centrifugal fan for ducts longer than a meter or so.

I have an axial fan blowing a gale through 5m of duct, so I feel you may be
in error there ;-

Yesh, I had a 100mm axial fan in the loft, venting through probably 3 m
or so of duct (out through the roof). worked fine.
--
Chris French