Extractor fan – Am I wrong?

[NotAGolf]

We have got a mild mould problem in our bathroom. We don’t have an extractor fan currently and just rely on leaving the window open. We get bit of mould on the ceiling which I bleach clean every ~9-12 months.

We’re about to redo our bathroom and I thought about installing an extractor fan to help reduce the mould problem, but I’ve stumbled into a few issues:

• Due to the size of the bathroom and window, the fan would have to be ceiling mounted not wall mounted
• The roof pitch is shallow, so we wouldn’t be able to vent it out of the soffits and instead would have to run the duct ~5/6 metres and out the side of the house
• I don’t want an extractor that you have to manually switch on/off (a pain) and I don’t want one linked to the light (seems silly having to turn the light on during the day), which leaves the option of a humidistat, but the majority of these seem to get pretty bad reviews, primarily due to reliability

Given the above issues, and the faff and cost involved, I’m thinking of just sticking with the good old-fashioned window option and occasionally giving the ceiling a scrub. Do you think this is a reasonable decision or am I being a moron?

 

[Syla5]

Why are you having to duct 5 to 6 metres when you say you have a shallow pitch roof? You aren't obligated to vent out of the soffits, surely you can just go straight up and replace a roof tile with a vented tile? This is what we have.

Also how do you expect the extractor fan to turn on? did you want it sensor driven? I haven't seen much of sensor driven extractor fans, but maybe its an option.

 

[SimonR]

Depends if you are happy to live with black mould, which is potentially toxic and can cause lung disease. Its your call. For the cost of a fan, a roof tile and a bit of work, I'd rather not have the mould.

 

[samcat]

Do it properly, fit a vent.

As above, either go up through a tile or do the 5-6 metres in rigid smooth hose.. the flexi silver stuff really messes up airflow and is very restrictive.
Fit a good sized inline fan, suspended on bungees or mounted to a good sized board thats resting on a pile of fluffy loft insulation (this helps de-couple it)

A good (large) fan turned down will be near silent and will move a surprising amount of air. If not humidistat or light control then do as we did on our old place, fit a pull cord that turns the extractor on. Simples.

 

[kindai]

Just have a ridiculously high cfm fan that turns on when you have the light on and has a long over-run timer for when you are done.

You dont need to leave it running all day, just while you are showering and a short period after and that will solve 99% of the issues. One directly over the shower will work best but just getting the air moving out will do the job.

 

[hornetstinger]

Went for a monsoon hug CFM fan myself looks like a jet engine. Inline. Has a timer.

Ones with humidity sensor getting too expensive.

Either run it off light swith with timer or maybe just have a dedicated pull cord

 

[a1ex2001]

Just run it off the light the cost of running a few modern led’s while you have a shower is nothing compared to the cost of heating the water! What ever you do fit one mouldy ceiling is not an option if you ask me.

 

[Duke]

As mentioned have the extractor vent above the shower as that's going to cause most the steam and set it to stay on for a bit after the light is turned off.

 

[NotAGolf]

Why are you having to duct 5 to 6 metres when you say you have a shallow pitch roof? You aren't obligated to vent out of the soffits, surely you can just go straight up and replace a roof tile with a vented tile? This is what we have.

Good point. The main reason for that is that I'd be comfortable drilling a hole out the side of the building myself, but not if going through the roof tiles. A leaky roof is the last thing I need! Yes we could get someone in, but for such a small job I think it'll be tricky.

Also how do you expect the extractor fan to turn on? did you want it sensor driven? I haven't seen much of sensor driven extractor fans, but maybe its an option.

Yes, a humidistat, but as I say, the ones I've seen have pretty bad reviews.

For the fans that run off the light switch, how long does the over-run timer last for? Is it long enough to clear a particularly steamy room?

Would it be much more effective than simply cracking the window?

 

[kindai]

Would it be much more effective than simply cracking the window?

Yes, an extractor fan will physically be moving huge qualities of humid air out of the room forcing dry air to take its place. Cracking a window allows the humid air to escape, but a lot slower and also allows it to settle on surfaces.

Take a relatively cheap example: https://www.amazon.co.uk/d/Home-Kit...id=1552513385&sr=1-5&keywords=inline+duct+fan

245cublic meters an hour shifted, 4 cubic meters a minute. I have a small bathroom and that essentially means it replaces all the air every 3 minutes in my bathroom (probably less by the time you factor in volume lost from the stuff in there).

 

[Syla5]

Good point. The main reason for that is that I'd be comfortable drilling a hole out the side of the building myself, but not if going through the roof tiles. A leaky roof is the last thing I need! Yes we could get someone in, but for such a small job I think it'll be tricky.

You slide the old tile out, slide the new tile in, it’s pretty straight forward and easier then core drilling your wall. We have one of the following for ours.

https://www.roofingsuperstore.co.uk...MI6_u1tZ6A4QIVz5TtCh01hwaPEAQYAyABEgLFS_D_BwE

 

[ChroniC]

If you don't go the extractor route I recommend this.
https://www.screwfix.com/p/zep-comm...MIm7_S4qKB4QIVCkTTCh1-fArpEAQYBCABEgIHhvD_BwE

Its the strongest anti mould I've ever used. Bleach does nothing, this stuff turned black mold white, on contact and it hasn't returned. I swear the mould pulls the water from the air or allows it to collect as after using this the bathroom actually gets less condensation too.

 

[manic_man]

The extractor fans in our bathrooms are simply run from a 2-gang switch so we have full control (i.e. single live to 2-gang, then output to lighting from L1 and output to extractor from L2 to isolator to fan itself).

It's a simple solution but works well as we can leave the fan running for as long as we want after using the bathroom, only downside is we sometimes forget to turn it off and leave a fan on all day (or night...)

I suppose you could do the above but also fit a fan with a timer for ultimate control but it adds the complexity of having to provide a second live to the fan (timer fans needs two lives, one switched, one permanent) and at that pint is there any benefit over simply using the switched live from the light, other than the light always needs to be on for the fan to come on, a problem if you have a decent light bathroom as all of ours are.

 

[Maundie]

We have an above shower extractor (with built in light) and it goes out through a roof tile as posted above, cannot for the life of me think why you would want black mould rather than get the job done properly.

Ours is operated via a direct switch (next to the bathroom light switch) and has a over run timer, never had a problem in the 7 years it's now been installed and haven't had a hint of mould.

 

[checjb]

We just fitted a Manrose extractor fan (https://www.screwfix.com/p/manrose-...or-fan-with-humidistat-timer-white-240v/15722, currently £29.99) which activates when the lights are turned on and runs for 10 minutes on timer (i.e. better than air freshener ). It also turns on when the humidity rises above 75% RH and continues until it falls below that value again. I went for this option as the kids would never remember to turn it on/off so the automatic option is the only choice. It's ceiling mounted above the shower and works well. It's ducted out through the wall in the attic (we also have a shallow slope to our soffits so it was much easier). I had a sparky do it all as I couldn't legally do the electrics (as the fan is in the bathroom, bit the attic) and also because I don't have anything suitable to core the wall.
It works well and is one less thing to worry about.