Kitchen extraction over a long distance

[Spare tyre]

At some point I need to redo my kitchen

I'd like an extractor built in above the hob, with it extracting externally to help reduce smells but mainly condensation

Due to the layout of my house the extractor ducting will need to take an odd route through the ceiling, into the roof space of a utility room then venting somewhere out of the utility


I'm guessing around 10 to 15 metres.

I guess the hob extractor won't be beefy enough so can I fit additional extractors in line, or is it not as straight forward as that

I was thinking in the loft above the utility room would be a good place to place additional inline extractors if needed

Any thoughts on my cunning plan

[henrycrun]

You'll need an inline fan. Help with choosing will come along soon...

[Pheo]

You can get remote / external extractors, they're much more powerful.

We went with recirculating in the end as duxting out was too difficult (boiler in the way!)

[dxg]

And use proper ductwork over that distance, not the flexible stuff.

[Steve57]

depending on roof space available, either spiral (round) or if tight on space you can get the plastic rectangular. shout if you need any further help/sourcing

[hairyben]

You'd be better off specifying a decent hood extractor or commercial type inline IMO rather than messing around with multiple fans.

Speak to your chosen manufacturer's tech line and see what they suggest, they may say some of the more powerfull models are suitable for that run so long as it's a 6" duct.

Also who's installing it, a half decent spark may have some suggestions re: ducting you might not have considered

Edited by hairyben on Friday 22 August 09:33

[sleepezy]

We are doing the same with about a similar distance from extractor to wall - our kitchen designer has specified a Westin Stratus. At the moment I am relying on their judgement as we're 7 months from having it all fitted still (owners opinions would be appreciated)... We looked at external fans but rejected the idea.

[blueg33]

When we were looking at a similar issue, the extractor manufacturer said that every 90 degree bend in the duct reduced the extraction power by about 50%.

If its a long run, I think in-line is the best option

[LaserTam]

We have a Westin Stratus (I think). I installed it myself and ran in the ducting. I rang them when I was planning it to make sure I had the right spec. When I explained my run (about 7m with 2 90 bends) they recomended the correct inline fan for the job. IIRC they did have a more powerful model, so hopefully that might be good for the job.
Cant remember what the remote fan cost, but the extractor 'hood' itself aint cheap, but it was the only ceiling flush model we could find that would fit in the ceiling void.

[LooneyTunes]

blueg33 said:

When we were looking at a similar issue, the extractor manufacturer said that every 90 degree bend in the duct reduced the extraction power by about 50%.

If its a long run, I think in-line is the best option

2 x 45 degree bends cost you less in efficiency than 1 x 90.

External vent covers / anti-blowback flaps murder efficiency.

Great link here: http://help.tradingdepot.co.uk/wp-content/uploads/...

[RevHappy]

If you have the cieling void space larger ducting will allow the use of commercial grade fan units. I've had Westin make some serious kit over distances that most the mainstream makes won't get near. Also look at Gutmann as they also have some decent kit. Neither option is going to be overly cheap if you want it to work, although room size and hob types plays a big part in the equation.