Continuous extraction fan

Posted 2nd Feb 2023

I have mould on the wall in the main living room and it was suggested that I should get a continuous extraction fan.

Am confused as there are a few and would like any recommendations?

Thank you

8 Comments

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2nd Feb
First off work out why you have mould in the living room. Do you dry clothes in there? Whereabouts is it, ie is the damp proof course covered, is there a leaking gutter or an overflow dripping and hitting the wall?
2nd Feb
hotukdeals.com/dis…311

This would work better if you can get one in your house
2nd Feb
An extractor fan would make sense in a bathroom or kitchen where you'd only be running it to clear the room of hot humid air, but I would think you'd probably be better off getting a dehumidifier rather than an extractor fan for a lounge, otherwise you'll be losing a lot of heat outside. If you did fit an extractor fan I'd suggest getting one with some sort of heat exchanger to recover some of the heat.

First thing to do as Jimbo says is to work out the cause and try to sort it out, and if it is condensation I'd also try to work out why the wall is cold and try to improve the insulation and prevent drafts. (edited)
3rd Feb
Try these.
nuaire.co.uk/pro…nge

I have them in my home and installed in my rental property. Never had mould or condensation
4th Feb
Yes good advice, I have one too, it positively pushes air into the house and can solve many damp/mould issues. I used to run it all year round but this winter I turned off (too cold air coming in from loft) and home isn't any damper.... but in more humid times I'll turn it on as it solves moisture on my ground floor walls, which is often misdiagnosed as rising damp.
3rd Feb
A dMEV extractor fan runs continuously at low speed for background ventilation. You can use a switch to boost to full speed like you would for a bathroom fan. These are made by many manufacturers, e.g. EnviroVent. Alternatively you could try a bathroom fan with a humidistat to switch itself on and off.

As others suggested, a positive input ventilation unit may be more suitable. This is usually put in the loft and ducted to one or more rooms and/or the landing to blow air into the building. There is also a wall mounted version for flats.
4th Feb
Best to find the cause of the mould. If it's not rising damp, a leak from gutters or another external issue it will most likely be related to condensation issue. Better to insulate the cold wall or try and find the cause where the water is coming from. Drill a fan in the wall doesn't alway solve the issue.
6th Feb
Apologies if this is a stupid question but is an extractor fan not better for the kitchen as it would extract the steam and grease from the kitchen and draw it to the outside of the house?

I mean compared to a PIV unit which pushes in fresh air from the outside, is it not possible the greasy steam from the kitchen could get pushed around the rest of the house?

From what I understand a PIV unit is recommended for controlling condensation but I didn't think it was recommended to install in the kitchen instead of a normal extraction fan, I thought it was more for the loft area or a wall unit in an open space like the landing. (edited)