Continuous Inline Bathroom fan available?

[MarkJohnson]

Hi all,

First post!

I recently acquired a rental property which has damp. One cause is that the bathroom extractor isn't working. I'm going to get an electrician to replace it but I thought I'd try and get one that instead of turning off simply reduced to speed to really low. I can see these are available but I can't see an inline one to replace what is already there which is a timed Manrose 41379.

So first question is do you think this is a good idea to help with general damp in the house?

If so do you know of such a beast (4" inline timed extractor fan that runs slow and continuously when not in use)?

Any other advice welcome.

Thanks in advance.

 

[Deleted member 267285]

So I’m guessing the damp is just in the bathroom? https://www.electrical2go.co.uk/ventilation/domestic-fans/inline-ceiling-fans.html States some of these are continuous? You can get humidistat fans, which operates on humidity, if that’s the cause.

 

[opps]

So I’m guessing the damp is just in the bathroom? https://www.electrical2go.co.uk/ventilation/domestic-fans/inline-ceiling-fans.html States some of these are continuous? You can get humidistat fans, which operates on humidity, if that’s the cause.

Wow, they are way more expensive than I would have guessed.

Last year I replaced a massive in-line fan in my local pub. After extensive googling, I got it for about £100. That runs for about 12 hours a day, 14 hours on Friday and Saturday.

 

[MarkJohnson]

Hi,

Thanks for your reply but I can't see any of those stating continuous trickle running unless I'm missing something?

The full story. The tenant reported leaking into a bedroom. After 2 roofers did work and the leak continued, the last roofer was confident it wasn't a leak and thought it was loft condensation. He offered to fit tile vents which I declined until I looked into it further. After researching and a visit from me I have made some improvements with more to be made. Even 3 hours after the shower was used the bathroom was literally saturated with water dripping off the ceiling, and this with window open. Unfortunately, the tenant doesn't have the heating on except for a couple of hours in the evening. This means the bathroom is really cold, massive condensation, and because of no heating the bathroom isn't drying out (ext temps 4-8C), even with the window open. I'm trying to educate the tenant that he needs to keep the house warmer but in any event since the extractor needs needs replacing one with a continuous trickle fan seemed like it could only help. Family of 5 in 3 bed ex-council house.

 

[Deleted member 267285]

Apologies, I didn’t actually read any of the spec’s, it’s what was returned on a google search, which on the opening line of their site mentioned continuous running. Need that heating on, otherwise, as you’ve seen too much moisture in the air will condensate on the walls and ceiling creating mould.

 

[opps]

It might be the case that when the bathroom door is closed, there is insufficient airflow passing under the door to suck the steam through the extractor.

You may need to fit vents in the door to help air enter the room (and exit via the fan).

I appreciate that you mentioned opening the window though- was thinking more of when you upgrade the fan.

 

[EFLImpudence]

The full story. The tenant reported leaking into a bedroom. After 2 roofers did work and the leak continued, the last roofer was confident it wasn't a leak

Firstly you need to definitely stop any leaks or everything else is futile.

and thought it was loft condensation.

Where does that come from?

He offered to fit tile vents which I declined until I looked into it further. After researching and a visit from me I have made some improvements with more to be made.

Even 3 hours after the shower was used the bathroom was literally saturated with water dripping off the ceiling, and this with window open.

That's ridiculous and (without leaks) indicates an enormous amount of humidity in the rest of the property.
I have known one property which had a really damp alleyway outside the ground floor bath room which if the window was open it made it worse.

Unfortunately, the tenant doesn't have the heating on except for a couple of hours in the evening. This means the bathroom is really cold, massive condensation, and because of no heating the bathroom isn't drying out (ext temps 4-8C), even with the window open.

Ok.

I'm trying to educate the tenant that he needs to keep the house warmer but in any event since the extractor needs needs replacing one with a continuous trickle fan seemed like it could only help.

It shouldn't be necessary.

Family of 5 in 3 bed ex-council house.

And pets? Washing drying indoors? Cooking in unvented kitchen? Lots of plants? Bath left unemptied (yes, I have known that - didn't bother to ask why).


Before you bought the house, when you viewed it, was it unoccupied and if so was there condensation such as you now describe?.

 

[Murdochcat]

The other thing to consider is with the window closed OSS there enough air flow under the door? If not, this must be improved too

 

[MarkJohnson]

Hi All,

Thanks to everyone for reading and especially trying to help. I'll try and cover the points raised below but please excuse any quoting issues!

Firstly you need to definitely stop any leaks or everything else is futile.

Two roofers have been unable to stop "the leak" with the last coming back out and doing much more inspecting/dismantling and being confident it wasn't a roof leak. He also said these houses didn't have any ventilation at the eves. Since he identified it as condensation it hasn't had the issue any more despite really cold external temps. I suspect when the tenant heard condensation was the problem he started making more of an effort with the bathroom window.

Where does that come from?

From my research loft condensation is almost always caused by excess moisture from the house making its way into the loft.

And pets? Washing drying indoors? Cooking in unvented kitchen? Lots of plants? Bath left unemptied (yes, I have known that - didn't bother to ask why).

No pets. No tumble dryer so will be drying clothes (family of 5!) indoors, they say they have a dehumidifier but don't know how much they use it. Kitchen is unvented and I'm sure all their food will be homemade. Little to no plants.

Before you bought the house, when you viewed it, was it unoccupied and if so was there condensation such as you now describe?.

The tenants moved in during Oct 23. For the previous 6 years my daughter lived there with no problems. However, single adult and one small child. She didn't cook much. Liked a warm house so heating much used. She did also have a working extractor fan. Also had tumble dryer.

The other thing to consider is with the window closed OSS there enough air flow under the door? If not, this must be improved too

Yes, there is sufficient air flow under the bathroom door.

So far I have sealed the loft hatch as it is immediately outside the bathroom door, Added firehoods to the bathroom downlighters. Added felt lap vents in the loft but I'm going to add more. The bathroom ceiling has no loft insulation. I'm guessing it was removed when the bathroom was renovated before my daughter lived there so once the extractor fan is fixed I'm going to insulate it.

I made a damp/condensation/mould guide (just a single A4) to give them advice on controlling the problem. I've also told him that he is risking the health of his young family by allowing so much damp and that mould is an inevitable consequence.

I lent the tenant a weather station and put the remote sensor in the loft. The living room was only 12C at about noon the other day with external temp being about 10C.

As has been mentioned, the core issue is the moisture created as a natural product of 5 people and the cooking/bathing/drying/breathing needs. The cold house is the main issue as I see it as the moisture is condensing and then there is insufficient heat to evaporate the damp even when ventilated.

I can only do so much. If I get the inline bathroom extractor replaced, especially with a trickle feature, it can only help since it is currently not working at all.

Thanks everyone for reading.

 

[old duffer]

If your fan can expel 100m3 of air per hour and you only have 80m3 per hour able to come into the room to replace it, it creates an imbalance in pressure and through-flow is not achieved.

 

[mcprinter]

Might be worth having a look at a PIV system.
Don't know a lot about them other than what I have read

Positive Input Ventilation: the pros and cons

Positive Input Ventilation (PIV) units alleviate condensation - but are they the most effective method? Read our guide on PIV units to find out.

www.permagard.co.uk

Nuaire and Vent Axia seem to be the most common makes.

 

[old duffer]

Might be worth having a look at a PIV system.
Don't know a lot about them other than what I have read

Positive Input Ventilation: the pros and cons

Positive Input Ventilation (PIV) units alleviate condensation - but are they the most effective method? Read our guide on PIV units to find out.

www.permagard.co.uk

Nuaire and Vent Axia seem to be the most common makes.

the principle is scientificality sound however, the installers are not. I paid for full surveys from "experts" and they arrived with a hand held temperature and humidity sensor and a tablet to enter data. I asked how they were going to measure airflow changes rates and internal pressures in each room but they said they can't do that. I asked them how they could give me a written guaranteed that their system design would suit my needs...they said they don't give operational assurances never mind guarantees based upon their calculations.

 

[EFLImpudence]

The tenants moved in during Oct 23. For the previous 6 years my daughter lived there with no problems. However, single adult and one small child. She didn't cook much. Liked a warm house so heating much used. She did also have a working extractor fan. Also had tumble dryer.

There you go.

You need new tenants.

 

[blup]

Clothes drying in a house with poor ventilation and insulation is going to be problem. Definitely put in a continuous extraction in tne bathroom or a timed overrun extractor that always comes on with the light. Even if it doesn't fully resolve the problem you have a defence if they complain to the Council. The bathroom door needs a gap at the bottom if the extraction is going to work more efficiently.

 

[flameport]

Added firehoods to the bathroom downlighters

That achieves nothing.

If the lights are not 100% sealed types they need to be replaced with ones which are.
Firehoods have one purpose - to slow the spread of fire through the holes in the ceiling if there is a raging inferno in the bathroom.