Extractor Fan Leaking

JOHNPT

I recently purchased a replacement inline extractor fan for a bathroom with the fan located in the attic and its vented to outside. The problem is its leaking water into the bathroom. Not sure if the reason is fan is not of sufficent strength. I purchased it in an electricial wholesalers however it dosent have a flap which opens and closes when fan turns on and off. Do i need better quality fan or any advice appreciated

Martron

what is happening the steam from your bathroom goes into the attic where it is colder as it goes past the insulation and condenses inside the pipe. thus turning back to water and running back into your bahroom. try insulating the pipe going through your attic.

JOHNPT

Thanks for your reply. The pip seems to be a white flexible type. WHat would i use to insulate pipe? Would fitting a more powerful fan be any good?

Martron

the instant the warm steam hits the cold pipe it will form condensation. fitting a more powerful fan may help getting more steam out before it condenses but at the end of the day the steam will be hitting the cold pipe. and forming some sort of moisture inside the pipe.

i am sure some of the other lads may have some other ideas but that is my take on it

also check that the outlet is not blocked in any way preventing the vapour gtting out. this could be causing a build up of steam inside the pipe


also you could divert the pipe. i am guessing your outlet heads straight up to the roof. if you divert the pipe to the soffit under the insulation in your attic it may help. thats just an idea i have had and may be open to correction by the other lads here

gorwanvfr

Have to agree with Martron its condensation. Wrap the flexible ducting with insulation, fiberglass would be the easiest and possible the cheapest.

jack of all

Try and run your ducting with a slight fall towards the outside, so that any condensate that does form can discharge to the external vent grille. If insulating the duct is difficult try replacing it with the insulated flexible aluminium type, it is more expensive though and it can be difficult to source as most places only seem to stock the cheap as chips pvc flexi stuff.

JOHNPT

Thanks for all replies. So aluminium ducting is the best soloution? The inline fan that is there now has not got a flap which opens when fan turns On and closes when fan turns Off. Should i get this type of fan or would this make any difference too?

Martron

the flap wont make any difference as the water will run as far as the flap and collect there . and whaen the flap opens again the water will still come through.


whether you get aluminum of not the duct must be insulated. insulated you current duch with some cheap insulation and see if that works.

eddieham

Even with insulated ducting you can and will still get condensation forming. Ducting manufacturers recommend using a condensation trap in-line with the ducting.
On page 9 of the attached link you will find a condensation trap made for ducting.(Used to work with these guys). Many others also supply
This trap will need a hose or similar attached to allow the water to drain, usually joined in to water tank overflow pipe or else directly out.
You will be able to order these in any electrical/plumbing wholesaler.
Hope this helps

http://www.atc.ie/heating_ventilation/documents/06_POADuctingAccessories.pdf

Joey the lips

It all depends on a couple of things.

If the fan is exiting through the tiles then you make sure its going straight up, You fit a non return valve usually half way. You make sure its as straight as possible.

If its exiting out though the eves you slope it out. Simple