Which extractor fan for bathroom with shower

[pr1970ster]

Hi All

We have a rented flat thats been having continuous problems with mould growth on the ceiling (anti-mould painted!?).
The room is 5ft 7in / 1.7m square and has a bath with shower attachment which gets used twice a day at least.
We`ve installed 2 different extractor fans over the years.
The last one (4in) was this, with a long timer setting , think it was 40mins and gives 85 m3/h air flow.
https://www.tlc-direct.co.uk/Produc...s&kw=nvf100t&gclid=CLCB0NrDksYCFQYxaQodgwEA2g

The tenants are still getting mould even leaving the window slightly open during and after showering.

I`ve tried the tlc-direct fan calculator and it recommends 5 or 6in fans which is 185 m3/h + air flow. So i`m now considering replacing it for a larger fan.

Anyone think this is the right route to take or am I wasting money on this? I`ve had suggestions to just get some commercial mould spray and repaint over it once a year.

Thanks in advance

 

[EFLImpudence]

Nope, the fan is not the solution.

Unless there is a leak somewhere the problem is the tenants.

Leave the window wide open and another somewhere else.
Open the kitchen window when cooking, washing, drying clothes etc.
When the weather is reasonable open them all.

Do they complain about dust or do they remove it?

Does the mould occur when the flat is vacant?

 

[pr1970ster]

Thanks, yes they are keeping the window open in the bathroom during and after showers. We lived there for 4 years and I dont remember having any damp problems but we did have an old style window with a vent built in. It was replaced after we moved out with a full pane double glazed window so not sure if that has changed things.
I think its two professional women that probably have showers morning and evening. We got them a dehumidifier and also a vented tumble dryer for the flat and that has helped as they were drying clothes in the flat.
Theyve also tried sprayer anti-mould spray. Problem is the ceiling in the bathroom is not smooth, its a textured finish and its not clearing it. It hasnt been vacant for long enough but I dont think the mould is there when its empty.

 

[phatboy]

Do you have the option of having a fan exit via the ceiling, and then outside? An inline fan, such as this https://www.tlc-direct.co.uk/Products/SLTD250T.html will shift plenty of air, as long as they keep the window a bit open to allow fresh air back in.

Is there a 10mm or more gap under the bathroom door as well to let air in?

 

[EFLImpudence]

Thanks, yes they are keeping the window open in the bathroom during and after showers.e]

Of course, they are.

We lived there for 4 years and I dont remember having any damp problems but we did have an old style window with a vent built in.

There you go.

It was replaced after we moved out with a full pane double glazed window so not sure if that has changed things.
I think its two professional women that probably have showers morning and evening. We got them a dehumidifier and also a vented tumble dryer for the flat and that has helped as they were drying clothes in the flat.

Partly remedied.

Theyve also tried sprayer anti-mould spray. Problem is the ceiling in the bathroom is not smooth, its a textured finish and its not clearing it. It hasnt been vacant for long enough but I dont think the mould is there when its empty.

The mould is a symptom.
The cause is the condensation.

I have a lot of experience with this and the tenants will not accept that they are the problem.
I look after fifteen flats and the same one can be a tropical hot house (you can feel the humidity when you walk in) causing clothes in wardrobes and shoes under beds being ruined by mould OR no problem at all depending on the tenants.

 

[pr1970ster]

Do you have the option of having a fan exit via the ceiling, and then outside? An inline fan, such as this https://www.tlc-direct.co.uk/Products/SLTD250T.html will shift plenty of air, as long as they keep the window a bit open to allow fresh air back in.

Is there a 10mm or more gap under the bathroom door as well to let air in?

Dont think theres any room for a ceiling unit, its in a convert victorian house. The current extractor is kind of head height at one end of the bath (opposite to the shower).

Cant say for sure theres a 10mm gap under the door. I dont think so because I remember once having to trim it slightly to get the new bath flooring we had fitted years ago.

 

[phatboy]

How far does the fan need to push the wet air until it reaches outside? And is it a horizontal run, or vertical up/down run? This all makes a difference.

 

[pr1970ster]

How far does the fan need to push the wet air until it reaches outside? And is it a horizontal run, or vertical up/down run? This all makes a difference.

Its a horizontal run through an exterior wall of a victorian block. I`m guessing 1 1/2 feet to the outside.

Thanks

 

[ban-all-sheds]

Ye cannae change the laws of physics with sprays and paint.

If you put water vapour into the air and just leave it you will get condensation.

The only fix is to get rid of the moist air and replace it with dry.

 

[phatboy]

How far does the fan need to push the wet air until it reaches outside? And is it a horizontal run, or vertical up/down run? This all makes a difference.

Its a horizontal run through an exterior wall of a victorian block. I`m guessing 1 1/2 feet to the outside.

Thanks

Maybe get a centrifugal fan then, they can shift more air than the standard wall fans. They are bigger though.

https://www.tlc-direct.co.uk/Images/Products/size_3/BGCF200S.JPG

 

[pr1970ster]

How far does the fan need to push the wet air until it reaches outside? And is it a horizontal run, or vertical up/down run? This all makes a difference.

Its a horizontal run through an exterior wall of a victorian block. I`m guessing 1 1/2 feet to the outside.

Thanks

Maybe get a centrifugal fan then, they can shift more air than the standard wall fans. They are bigger though.

https://www.tlc-direct.co.uk/Images/Products/size_3/BGCF200S.JPG

Is a large centrifugal fan like that necessary, its only a foot or so length of pipe. they seem to say those are more for longer lengths of piping upto 50m length. It also gives 110m³hr, where as I`ve seen others that are 180m/3 hr that would fit but arnt so large. iehttps://www.tlc-direct.co.uk/Products/SLS200CHZ.html

 

[phatboy]

The one you linked is for a 125mm, whereas the one I linked is a 100mm (4") pipe.

 

[pr1970ster]

ok thanks. There is room for that 125mm one thats all. It would just need some new ducting, but the cavity is quite large as I remember. Just going by tlc-direct fan calculator they recommended that one.

 

[phatboy]

I'd expect the current hole to be just over 4", and in a Victorian property made from stone / concerete, so cutting the hole to 5" would be an expensive job?

If you have the means to do it great, a bigger pipe will of course allow better flow and a more powerful fan.