I have a fitted kitchen which has a double fan unit built in extractor, this
will be used in re-circulating mode ... so the air comes in at bottom
through various filters and out through top of cupboard.

Well that last bit is the problem, the kitchen fitters left it with top of
cupboard still intact, so the air if I switched it on would just blow into
the cupboard.



The system is designed to re-circulate as in kitchen ceiling I have a whole
house ventilation extract point.



I checked with Neff and they advise that either I use a ducting kit (can't
as length is to far from external wall) or I cut a hole in top of cupboard
and just let it vent.



I don't like that idea and want to fabricate a grill or extract port on top
of cupboard .. still venting to the air, but at least better than just a
hole in top of cupboard.



Also if I put some sort of vent there I could place layer of filter
material in there as well, it would also stop anything ever falling down the
hole into the fans.



What I need is something to take 150mm diameter fan outlet and connect that
to a grill or frame on top of cupboard that is at least equiv c/s area, and
if it can also hold a piece of filter material then that is a bonus.



Any ideas ?





Rick