Best extractor fan for bathroom ?

[EFLImpudence]

I appreciate the iris acts as a barrier but you would surely have a barrier at the outlet would you not ?

Why, where is the wind going to go?

The external vent is forced open by the flow of air, sealing closed after the unit is switched off. If there is no externally closed vent, then surely all manner of items could enter and would only be prevented from entering the bathroom by the iris closure. If that were the only barrier, it would appear insufficient.

You were talking about backdraughts.

You could still fit a grill/gauze on the exterior wall to keep out insects (which the usual flaps won't/don't).

 

[mattylad]

What are they like for noise though?

 

[Talay]

What are they like for noise though?

What is what like ?

The noise consensus seems to be measured at 3m or something which is utterly pointless if it is being used for a through the wall application at 40cm.

However, I still see the decision process as first needing to establish the type of technology and power required. Until I get to that point, any "decision" is just a finger in the wind and hope for the best.

 

[Talay]

You were talking about backdraughts.

You could still fit a grill/gauze on the exterior wall to keep out insects (which the usual flaps won't/don't).

I guess a tight grill / gauze would help stop the bugs etc. but I would have thought a decently designed backdraft flap at the point of entry would be largely sufficient. Surely they have perfected a design specification for that by 2012 !