Condensation in Flexible Ducting

[LordSoth]

Hi Folks,

I recently replaced our old shower enclosure extractor fan with a newer, more powerful fan in our roof space.

The original fan had been left simply venting into the roof space.

I hired a core drill & drilled through both pieces of the cavity wall & continued on with the flexible ducting to a pipe through the wall & an external grille.

The best way to describe this is that the fan is in the middle of the ducting with one end terminating at the shower & the other the external wall.

I had reason to be in the roof space last weekend & I noticed that the flexible ducting, which is lying horizontally across the rafters on top of the insulation, was sagging on both sides of the fan. A quick check showed that water had condensed on both sides & was causing the ducting to sag.

I was able to empty the condensed water by disconnecting the ducting at the fan & tipping the water out each end.

My question is: what would you recommend to either prevent this condensation from re-occurring or draining away the condensed water? Any condensation traps I have seen appear to be 'in-line' & IMHO couldn't be used where the water is actually condensing.

MTIA

Soth

 

[doitall]

Lag the pipe

 

[Dan Robinson]

How long is the run?

You could insulate the pipe.

I suppose you you make the pipe rise vertically to above the level of the outlet. Then slope towards the external grille. Not a great solution though.

 

[swidders]

Or, support the pipe fully

 

[doitall]

The correct thing to do if the insulation doesn't cure it would be to run an overflow to somewhere, depends how steamy the bathroom gets.

 

[JohnD]

if the pipe is lying horizontally on the loft floor, it is easiest to flop some loft insulation over it.

 

[ambi]

Just a thougth..Make sure ducting is angling away to the external outlet and that no rain is finding its way into the duct from outside?

 

[LordSoth]

I wasn't sure if lagging the ducting was a good idea but - given your suggestions - I will certainly give this a try as lagging is dirt cheap in B&Q at the mo!

MT

Soth

 

[swidders]

I wasn't sure if lagging the ducting was a good idea but - given your suggestions - I will certainly give this a try as lagging is dirt cheap in B&Q at the mo!

MT

Soth

but keep it off the electrics and cable!!