[1 AKY]

Not the most riveting of matters, but here goes.......

Installed this myself a few months ago but only recently has started making noises. Thought it was bearings/impeller but it transpires that blades are hitting the water collecting in the bottom of the fan-unit housing.



Also have a condensation trap installed at the bottom of the vertical fall, along with a backdraught shutter which is situated just prior to the external roof exit.

The most obvious thing is the lack of insulation around the ducting. But whilst I've got time on my hands, don't mind dismantling/changing the setup to achieve a more effective and permanent solution, e.g. placing the fan in a vertical run with the trap at the bottom??

Advice/thoughts welcome.

[Harryg]

I would extend the vertical pipe and put a condensation trap at the lowest point, if that is the trap you have half way down the horizontal pipe any condensate will run past it as it is doing now, have the horizontal pipe so it drops then extend the vertical pipe to prevent the run back.

[Craig-SM]

Insulation is the biggest problem as it will be cooling too quickly and going from steam to liquid.
Also the pipe run has an additional bend that you don't need and it would shorten the length too keeping the steam hotter for longer

[bishbosh]

Insulation would be my first course of action, to reduce the condensation that'll occur with uninsulated ducting.

This is an extractor I put in going out through the gable end. The insulation is wire wound so it won't collapse.

[t5pilot]

Originally Posted by bishbosh

Insulation would be my first course of action, to reduce the condensation that'll occur with uninsulated ducting.

This is an extractor I put in going out through the gable end. The insulation is wire wound so it won't collapse.

That's the way to do it, with the fan at a higher point if possible, eliminating any condensate element.

But, OP, Your duct run isn't ideal. Your fan, ideally, needs to sit as close to the bathroom as possible. Then I'd personally ditch the plastic pipe & do a direct run to the exit with flexi duct. On a shorter run like that, you'll not have a condensation issue.

[t5pilot]

I was limited with this installation, as I wanted to use a redundant flue exit that was already installed.
But with the flexi stuff, the ridges take care of any condensate so it can't run backwards. This has been in nearly 2 years now. Any collected moisture eventually evaporates.

[1 AKY]

Thanks to all for their responses so far. Much appreciated

Having looked at the pic with a fresh pair of eyes, I've realised that having a ventilation tile immediately above the first 90 bend doesn't help matters, so will try and address that somehow. Insulation will be the first port of call. I'm also thinking of changing the setup but am restricted by both the height and the access to a full roof tile in between the rafters (for external venting).

I'm not sure whether you've understood the vertical/horizontal orientation of the ducting so have annotated the pic in the original post.

[Watsey]

What sort of vent tile did you install ?

If it's a tile vent, i.e. a vent designed to look like a tile, these typically require a significant roof pitch so as to avoid problems. The tiled roof on the rear extension on my house has a shallow pitch of around 17° and when there was heavy rain it would run back through the tile vent, into the duct, and come pouring through the cooker hood extractor. The builder had to change the routing and run the duct down to an eaves vent grille - we've not had any problems since.

If you're using a mushroom head vent these can cause problems if they are used in a pitched roof.

I'd start by getting a clear understanding of whether you're getting condensation or water ingress - how you deal with the problem could be quite different according to the cause.

[DB118D]

Sorry to barge in, but what are folk using to insulate the flexi hoses?

[bishbosh]

Originally Posted by DB118D

Sorry to barge in, but what are folk using to insulate the flexi hoses?

Something like this:

https://www.ductstore.co.uk/acatalog...e-Ducting.html

[t5pilot]

Originally Posted by bishbosh

Something like this:

https://www.ductstore.co.uk/acatalog/DEC-Isodec-Insulated-Flexible-Ducting.html

I do really feel this stuff is a waste of money.
For domestic extraction certainly.
Condensation is caused by the steam cooling on a cold surface. Your loft is cold. Ducting in the loft will be cold, whether it's bare or insulated - it's still cold as the duct doesn't have a heat source.

[bishbosh]

Originally Posted by t5pilot

I do really feel this stuff is a waste of money.
For domestic extraction certainly.
Condensation is caused by the steam cooling on a cold surface. Your loft is cold. Ducting in the loft will be cold, whether it's bare or insulated - it's still cold as the duct doesn't have a heat source.

Not necessarily, my bathroom has a vent in the ceiling above the shower area. Any warm air will naturally rise so the air in the pipe should be slightly warmer than the air in the loft. There's a draught blocker on the outside vent. When the extractor is on the inner part of the ducting will warm up and lose the heat slower than an uninsulated pipe.

Also it's less than £20 and a damn sight quicker to install than cutting/welding plastic pipes

[EvilDrPorkChop]

Move your drain point to the lowest point and insulate. Should be fine then.

[shoestring]

Open the window for a few minutes after showering and no vent needed!

[Alscoob]

You guys need more insulation in the roof in those pics, direct cold bridge through the ceiling joists!!

[bishbosh]

Originally Posted by Alscoob

You guys need more insulation in the roof in those pics, direct cold bridge through the ceiling joists!!

I know mine's a 260 year old cottage, but the photo is of the extension built in the 70s. All the insulation needs ripping out and redoing. Above the old part of the house there's only a shingle type of insulation! It's all a hazard as there's mouse shite everywhere