Internal room extractor fan - cold air coming in

phelimb

Not sure if this is the right forum but here goes...

I have a small internal bathroom/toilet (single story house) with an extractor fan connected to a flexible hose in the attic that kinda goes as far as the eaves as far as I can tell. But the room is very cold especially recently given the cold weather, so I'm guessing that there is cold air coming in through the hose/fan. I don't see any filter/flap to stop the cold air coming in at either end. Google tells me I need some kind of backdraft flap on the fan or maybe some kind of vent at the other end to only allow air out and not in but I've not been able to find a definite answer...

Any thoughts or ideas on what I need to do?

GreeBo

Can you just add one of these

https://www.screwfix.ie/p/manrose-cowl-vent-white-100-x-100mm/16195?gclid=Cj0KCQiAw9qOBhC-ARIsAG-rdn5kZRBgOcwxZya-KiFCcEa579RIwm_Hz4vOTBdc2dr9ToY6k59BKvwaAnLsEALw_wcB&gclsrc=aw.ds

phelimb

Yep - I think that's what I need. And for that price if it doesn't work then no worries...

Thanks.

FrankN1

Is it safe to use one of these on an outdoor wall leading from extractor fan inside? E.g. will the extractor fan still be able to work and let out the air/dust etc

Buffman

https://www.boards.ie/discussion/comment/118431181#Comment_118431181

Yep, the extractor fan is blowing the indoor air out of the house at the outdoor wall and will push open the flap when it operates. The flap stops outside air/wind from getting inside when the fan is off.