additional bathroom extractor query

9 Jul 2006
Reaction score
United Kingdom
Electrician installed an extractor fan last year in our small bathroom which was needed cause of condensation mainly from the shower.

condensation remains a problem and better extraction is needed. I'm thinking that an additional fan above the shower would probably do the job (or a better fan)

the corded pull switch operates the light and existing fan. the fan will remain on for 20 mins after switching off. Outside the bathroom there is a mighty big isolator switch. I presume this is a triple pole isolator. the existing fan extracts out of the wall. a new extractor will extract through the loft to the eaves. the wires are in the loft

presuming the new inline fan allows it, do i just insert the wires into the 3 pole isolator which presumably has the wires coming from it to the exisiting fan. I am happy for them to work exactly the same.

1 any probs with that?
2 Can you cram two lots of fan wires from an isolator switch. Is that safe?

i searched for answers here but didnt see a similar problem. any help is appreciated :) :)
Sponsored Links
Do you have a vent into the room ?

An extractor sucking out air will not be very effective if there is no route into the room for air to replace the air that has been extracted.

A large gap under the door serves the purpose.

Replacing the extrated air with cold air will increase condensation.
there is a gap under the door-its not massive. otherwise no.

so maybe a vent into the loft. is that what you are suggesting. perhaps with an additional extractor fan for super efficiency!
Not a vent into the loft.

Stating the obvious. Condensation occurs when warm air with water vapour is cooled when it meets either a cold surface or cold air.

So you need to replace the extracted air with warm air and NOT cold air.
Sponsored Links
ok so a vent out into the hallway perhaps above the door. tricky to do and i will consider doing it.

i am not entirely convinced though that will solve the problem. the door is often left slightly ajar anyway and i don't think the curent fan copes that well.

i may still consider the extra fan perhaps as well as a vent. in that sense i may have a way forward. what do you think? if so can i wire as first posted i.e from the isolator?

thanks for your help thus far by the way
I guess you currently have a 4" axial fan fitted. I think that the easiest thing for you to do would be to replace it wit a good quality 4" or even 6" (although you would then have to alter your ducting and vent!!!) Centrifugal fan still with a timed humidistat.

A timed humdistat will run on for the set time, but will then continue to run until the humidity level drops to a pre determined level.

BTW you should vent this moisture laden air to the outside and not into the house, what the others are trying to say is that you should replace the air from the bathroom with warm air from the rest of the house, not through an air brick in the outside wall..
8) :cool:

From this I am going to try the following

1 stick in a vent into the room that will come from the hallway outside the toilet (not the loft or outside for the reasons stated which makes sense)

2 Get a better fan and see if that makes a difference. maybe one that detects the humidity as well as that sounds good (rather than just a timer)

3 Then and only if it is necessary install an additional fan

4 I presume that if the cat sticks to the vent that i install i'll know the extractor fan and vent are working well ;)

oh but if i have to to stick in the additional fan can i wire it up as asked?

thanks for your advice
remember not to do ANYTHING in there till you notify building control
Just to add,,,,

The position of the fan is quite important, what you want is for the fan to be as far away from the door as possible or you will short circuit the ventillation (if fan was near door then you would just be extracting the air drawn from outside the room).

There is also no point in having 2 extractor fans - just get one that will do the job adequately!

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links