Advice on fitting bathroom extractor fan

[TanDiy]

Hi, would really appreciate some advice on bathroom extraction. We have a small bathroom (10ft x 8ft) with a shower over the bath. The shower produces a lot of condensation on the two outside cold walls and we have had an electrician in to quote for fitting an extractor fan.

He has quoted to put a vent directly above the shower and to run this to a fan located in the loft. The fan will then extract to an external vent in the side peak wall) - the total duct from bathroom to external wall will be about 10-12ft.

Does this sort of arrangement work well or is it better to have a fan located in the bathroom. Thankyou.

 

[17thman]

its good advice to have the fan in the loft because the noise is awful when trying to relax if it is an axial fan. do you want it switched from the light or the shower switch? is it a new build or not? Another factor is that you need the outlet of the inline fan running downwards from the unit to the outlet point because of condensation. Certain scenarios would involve insulating the ducting.

 

[TanDiy]

its good advice to have the fan in the loft because the noise is awful when trying to relax if it is an axial fan. do you want it switched from the light or the shower switch? is it a new build or not? Another factor is that you need the outlet of the inline fan running downwards from the unit to the outlet point because of condensation. Certain scenarios would involve insulating the ducting.

Thank you for the info - it is not a new build and we want the fan switched with a pull cord. The electrician has proposed a small vent above bath running across to fan about 6ft away in loft and then duct running UP to vent in the outer wall so I think this will need to be insulated as you suggest. We are just worried about how effective this arrangement would be compared to a simple fan on the wall which is ducted straight through the wall.

 

[mointainwalker]

I don't know how difficult it will be to avoid, but I would not want to duct upwards to a vent. If you get any condensation it will run back into your fan and destroy it.

 

[JohnD]

the loft-mounted ducted ones can be more powerful and quieter than wall mounted ones. Ask him how many cubic metres per hour it extracts. Weedy cheap wall fans are about 80, powerful loft fans in the region of 240.

I would suggest putting the fan on a simple wooden platform in the loft so that the duct to the wall can run downhill to point of exit, as well as downhill to the bathroom vent. If it is stood on a rubber mat, this should reduce transmission of noise or vibration.

most people use flexible hose, but if it is run in soil-pipe or rigid ducting, which is straight and smooth, there are no convolutions for fluff, dust and water to collect.

Any ducting in unheated space such as a loft should be wrapped in insulation to prevent condensation in the duct. I'd suggest the loft insulation stuff with a silvered plastic wrapper, as it is so clean to handle.

Fans are very cheap to run, and if in the loft should be very quiet. I'd recommend having it turned on by the light switch, as some people have an aversion to ventialtion and will not turn fans on.

 

[Luckyphil]

If you can put up with the Fan noise , I`d ALWAYS go for a Wall Mounted Fan , Its a bit of a Ball-ache Core drillling the Wall , But if there are no Lintels os Services in the Way thats the way I`d go, As others have said when the Fan itself is in the Loft-space there is minimal noise , but the Flexi or Rigid Hose length seems are bit long to me , And reading what you say he still has to Core the End Wall to exit the Ducting ?


If its over the Bath it`ll more that likely need to be a Low Voltage Model (12v) go with Vent Axia always better than the Cheap and cheerful Models

Lucky

 

[JohnD]

water vapour is lighter than air, so it rises to the ceiling, so if you have a ceiling vent, it is not necessary to have it directly over the shower. However it is very important to have it running during and after every bath or shower. It is an advantage to have it come on when the WC is used as well.

if the fan is in the loft, not in the bathroom over the bath or shower, it does not need to be a weedy 12v one as the electrical safety regulations are less severe.

 

[Taylortwocities]

The best place for a fan is the point as far away as possible from the air inlet (usually the door).
That way the air is dragged across the room taking water vapour and curried smells with it.

Make sure there is a decent gap under the door to allow enough air into the room so the fan isn't trying to create a vacuum.

 

[sergeantash]

I had the same issue with bathroom ventilation need and opted for one of these:

http://www.lyonlighting.com/acatalog/info_EFKITL.html

You fit it directly above the Shower in place of one of the downlighters that you might already have installed there, the rest of the components sit in the loft. Try to avoid attaching the fan unit to the ceiling joists directly above the bathroom else you'll get noise/vibration, alternatively insert some acoustic insulation material beneath the fan unit.

Really pleased with mine!

p.s. Photo of ceiling/lighting finished, but rest of room was still in DIY stage...lol!

Untitled

• sergeantash
• 16 May 2010
• 2

 

[mointainwalker]

I suggest replacing that crappy concertinaed plastic tubing with rigid PVC pipe to reduce noise and stop water condensing in the folds and then , inevitably, leaking out sometime.

 

[sergeantash]

I suggest replacing that crappy concertinaed plastic tubing with rigid PVC pipe to reduce noise and stop water condensing in the folds and then , inevitably, leaking out sometime.

I don't think you noticed the caption above the photo

p.s. Photo of ceiling/lighting finished, but rest of room was still in DIY stage...lol!

It was only to show the extractor/downlight to the OP.

My bathroom now looks like this:

Untitled

• sergeantash
• 26 Feb 2012
• 1

 

[mointainwalker]

Well I did read it but focussed on this

Really pleased with mine!

which made me think it was all in as per the link i.e. with concertina