fan outlet dripping

[terence7556]

my son has an electric fan in hie ensuite and its dripping water, a droplet every 30 seconds.
went into the loft, which is well insulated and there is a plastic outlet to roof level from ceiling about 12 feet long with a 135 bend and a flexi connector just under his tiles. the water drip comes from the 135 bend down the pipe to inside the fan
to stop it should i insulate the pipe (110mm)or use silica gel or salt to try to absorb moisture in the loft
any suggestions?

[buildersmate]

Insulate the pipe, T.
I think you probably know what is happening here - the warm moist air extracted by the fan is being cooled by the cold plastic outlet pipe and water is condensing on the inside, and dripping back. If you insulate, you should be able to pursuade the water vapour to remain as vapour long enough for it to get to the external outlet - where it can drip to its heart's content.
If that doesn't work, can you angle the pipe so it flows downwards towards the outside, not downwards towards the fan? - then it will drip out, rather than in.

[terence7556]

i will insulate the pipe as i cannot alter the angle. it is nearly vertical with one kick to avoid the ridge, thanks for the idea though

[heathfield]

I fitted a ''condensation trap'' to overcome exactly this problem. Scroll down to the last section here.

The trap is a short section of pipe that has an internal water collection channel and a 20mm outlet connector. See a picture of one here.