JoeJoe wrote:
I am looking to install an extractor fan in a newly created internal
kitchen. The problem I have is that the nearest point to which to extract
(i.e. external wall) is some 4m away.

I will be fitting a 6" extractor as per Building Control instructions. The
ducting, together with the waste from the sink, will run behind a new
partition wall in the adjacent room. I would like to keep this new wall as
close as possible to the existing wall as the room is quite narrow already.

I intend to use a standard wall mounted fan - something like this one:
http://www.screwfix.com/app/sfd/cat/...23262&id=24840).
My question is: will it be OK to run 4" ducting for it along the 4m span?

If you can get hold of the flowrate vs. back pressure curves for the
fan it would be worth calculating its effectiveness in your proposed
setup. Further details, including the method and pressure figures, in
the Domus catalogue at
http://www.domusventilation.com/asse...CatOp05_06.pdf (5MB PDF).

Mathew