On Wed, 26 Jul 2017 03:31:45 -0700, Tricky Dicky wrote:

Just another thought the idea of two intake grills. The ceiling in
the bathroom will be lowered enough to fit some rectangular ducting so I
could fit two grills one over the WC pan and over the shower. Is this
gilding a lily or will this improve niff and vapour extraction? If
viable would I be better reducing down from 125mm ducting to 100mm
ducting to connect the two grills?

Finally which is better to fit a back flow restrictor immediately after
the fan or use a flapped wall outlet? The distance from the fan position
will be about 6m to the wall outlet.

I ended up with a flap just after the fan to prevent reverse flow when the
fan was off.

I think that this was because the run to the external vent was quite long
and it needs a bit of puff to open those external flaps.

One result is that on very windy days you hear the occasional flap noise
from the ceiling (or under the floor depending where you are) as the flap
blows shut.

With the twin vents I used the same size of pipe all the way because the
fans will shift quite a volume of air.

Cheers


Dave R


--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus