Geoff Norfolk wrote:
Can anyone explain to me the difference between a centrifugal and an axial
fan. In various catalogues, it appears one type is better at pushing the air
along ducting but all the fans seem to be just "propellers" spinning. Is
there any way I can put a decent fan in the bathroom ceiling which will
actually cause a howling gale rather than the minute draught that my £25
Screwfix one gives......... It's got a couple of metres ducting to the
outside wall.


centrifugal ones have a cowling that goes around the fan.
The air goes round the cowling rather than through the blades.
More of a turbine shape, at least inside.
The downside is that they are more bulky.
For commercial/industrial use they are preferred.