Kitchen extractor venting

[JDLDIY]

I plan to install the extractor onto an internal wall and then connect to ducting to take the nasty niffs through the ceiling space between the joists (3m) and out through an airbrick in the back wall.

Question is should the ducting be at an incline as it runs across the ceiling to allow condensation to drip towards the outside wall or back to the extractor and should I fit a condensation trap?

Otherwise I can fit it level and have done with it!

Many thanks

JD

 

[bathjobby]

If you can put it on a down slope towards the outer vent then do it as it costs nothing and you don't want anything running back towards the fan appliance. In reality though, you shouldn't have a huge problem with condensation as it is relatively warm in the ceiling space. I would recommend putting a self closing flaps on the end rather than through an air brick (the force of the air blown by the fan opens them); like this

It prevents gusts of wind blowing back down the pipe and keeps it that bit warmer when not in use therefore avoiding condensation. You can also get them with a cowl over them which is even more effective, like this (it has the same flaps inside as the one above);

 

[Mick Leek]

That is something i need... Looked at the B & Q places but nothing with flaps.. were do you get those from ?

thanks

Mick.

 

[JohnD]

They are sold by Screwfix. but some DIY sheds sell them in the tumble drier section.

I use the lower type, they don't rattle as much in the wind, and mine have a single large flap inside rather than the little louvres (which sometimes break off in strong winds)


the duct shouldn't get cold unless it's in the loft, and you could always flop a bit of fibreglass over it.

You can make a very neat 105mm hole in the wall by hiring a core drill from your local DIY Hire shop - when I hired one i did the kitchen and bathroom extractors, the downstairs shower and the tumble drier hole all in one session. Very easy to poke the pipe through and mortar round as the holes a good fit. No drafts and won't blow back in like through your air brick hole.

 

[nstreet]

I plan to install the extractor onto an internal wall and then connect to ducting to take the nasty niffs through the ceiling space between the joists (3m) and out through an airbrick in the back wall.

Question is should the ducting be at an incline as it runs across the ceiling to allow condensation to drip towards the outside wall or back to the extractor and should I fit a condensation trap?

Otherwise I can fit it level and have done with it!

Many thanks

JD

Unlikely that you would be able to fit a condensation trap anyway, not enough clearance in the void, unless you want the drain pipe spanning your kitchen wall.

 

[JDLDIY]

Thanks for the replies guys. The next problem I'm having with this job is that according to the installation instructions that came with the extractor it needs 150mm circular pipe to carry the nasty niffs away. Can I find it? Nope!! The other issue is that I then have to connect the pipe to a wall vent the other end and they are designed to fit onto 100mm pipes.

Anyone know where I can get 150mm pipe from?

Thanks again.

 

[JohnD]

No, but...

I gather this is an medium-sized extractor fan, not a cooker hood?

Is there an external wall in the kitchen where you could fit it direct?

 

[JDLDIY]

No, but...

I gather this is an medium-sized extractor fan, not a cooker hood?

Is there an external wall in the kitchen where you could fit it direct?

It is a large cooker hood extractor, to fit onto a wall and no I'm afraid we can't get it fitted to an outside wall.

Cheers

JD

 

[masona]

Anyone know where I can get 150mm pipe from?

Over here

 

[JDLDIY]

Masona you absolute star, dunno why I didn't think of tlc, had looked at plumbworld, travis, b&q, wickes etc etc and couldn't find any - much indebted.

JD