Please recommend a bathroom fan that will help with condensation in flat

[chaletstyle]

I will be refurbing an internal bathroom. Currently there is an axial low voltage fan on wall in zone 1 in corner of bath/shower area with about 9 ft of ducting to outside.

The flat has many outside walls and condensation / mould growth has been a problem in lounge and bedrooms.

The easiest thing would be to replace the axial fan using the ducting already there. Maybe with a centrifugal fan?

I was thinking if the fan can be on constant and ramp up when it detects humdity it might help. If it can also boost when the light switch is pulled, then even better.

If the fan can be almost silent when on low constant that would also be good.

I thought that Nuaire Cyfan might be the answer but I looked at the install instructions and it seem that it should be mounted on an outside wall...however my bathroom is internal.

ANy suggestions on a fan I can get fitted using the original ducting? Many thanks.

 

[JohnD]

photo of the old fan would be nice to show its position

is the duct 100mm diameter?

Do you have the chance to insert the fan part-way along the duct, for example in a cupboard, loft or false ceiling?

 

[EFLImpudence]

Fans do not 'help' (stop) condensation.

That you have it in rooms other than the bathroom indicates a more fundamental problem -

actual water ingress (leaks), excess humidity, lack of heating and ventilation.

 

[Iggifer]

Sounds like you want a dehumidifier for the flat, not a fan (well obviously you want a fan too, but it won't solve your problem). I used to live in a flat with a bit of damp (no mould, but a damp smell) got a 9ltr/day dehumidifier from Screwfix, and it literally needed emptying every day or two. If you have mould growing, it sounds like you have it worse than I did.

Back to the OP though, where do you see in the manual that that fan must be mounted outside?

 

[EFLImpudence]

A dehumidifier is not the answer either.

The cause must be rectified.

I used to live in a flat with a bit of damp (no mould, but a damp smell) got a 9ltr/day

Where did that come from?

 

[Iggifer]

No I appreciate it's not the answer but it's a short term solution that cures the symptoms. Often fixing the root cause is £££

Where did what come from?

 

[EFLImpudence]

Where did what come from?

The 9 litres of water per day.

 

[Iggifer]

Where did what come from?

The 9 litres of water per day.

Oh. Well some was from cooking/bathing etc but AIUI, all of the mortar in the building was shot (old building) and about a week after I moved out, pretty much all of the unrendered walls were repointed. I was told it was costing £15,000 per leaseholder or something, so somewhere in the region of £60,000-£75,000 if I remember. I have no clue whether this is accurate or not but the dehumidifier did a brilliant job for me in the interim

 

[JohnD]

I wonder if wet washing is draped on radiators

//www.diynot.com/wiki/Building:Condensation-in-Houses

 

[Iggifer]

not guilty in my case. Haha. Tried it once but it just made them warm and wet! But it could well be a possibility. But if it's got to the point where there's mould I think it might be worse than that

 

[chaletstyle]

Removing the cause...that's easy....Its amazing that there is no condensation when no body lives in the flat.


The flat has been tenanted and tenants do not look after things or vent or heat sufficiently. They do not use dehumidifiers (we had one). They dry washing on rads. Yet they deny they do any of those things. The aspect of the flat is very cold . I do not want to put anything in loft. The loft is not very well ventilated either but the freeholder will not make adjustment.

Hence the wish to get a background running fan and humidistat in current duct. The duct I imagine is typical diameter for internal bathroom fans, what ever that is

The position is in the high corner of the room; i.e. on the top of the wall tucked into a corner, just under the ceiling, above the bath taps/shower. There is a remote transformer unit 6 ft away.

The current fan is a low voltage zone 1 Steeple.

The duct runs along through kitchen where it is boxed in above units.

ANy suggestions on substitute models appreciated

 

[chaletstyle]

.

Back to the OP though, where do you see in the manual that that fan must be mounted outside?

The installation booklet does not have any fitting instructions or recommendations regarding ducting; it just shows it on an outside wall.

 

[Iggifer]

.

Back to the OP though, where do you see in the manual that that fan must be mounted outside?

The installation booklet does not have any fitting instructions or recommendations regarding ducting; it just shows it on an outside wall.

Maybe this isn't the model you mean, but this manual does, section 3.3

 

[JohnD]

this one is about twice as powerful as a typical cheap bathroom fan. It would have to go in the boxing-in you mention, because it is bigger, which will need a hatch for access to install and for maintenance.

You had better find out the actual duct size before you buy it. If you find it is 5 or 6 inches you can have a bigger fan.

Instead of a humidstat, get this one which can be wired to come on when they turn on the light, and adjust the timer for a 20 minute run-on. You say it is an internal bathroom so I guess no windows so the occupiers will probably turn on the light every time they use the room, so you are not dependent on them making a conscious effort.

It is very quiet and economical on electricity.

https://www.tlc-direct.co.uk/Products/SLTD160T.html

 

[chaletstyle]

.

Back to the OP though, where do you see in the manual that that fan must be mounted outside?

The installation booklet does not have any fitting instructions or recommendations regarding ducting; it just shows it on an outside wall.

Maybe this isn't the model you mean, but this manual does, section 3.3

Thanks for looking at it.
It seems very vague about the concept of duct work; can't see any info about max duct length.
TBH I've got a head ache just looking through all that writing. Needles in haystacks to me.
If you think I can use it with my duct then great.