Cooker Hood - Extract to external wall

[dodgem]

Hi all,

I plan to install a cooker hood within a raised chimney breast opening, in an open plan kitchen living room.

I want to ventilate it horizontally to an external wall using a 150mm diameter with a couple of 90 degree bends next to the cooker hood itself.

The distance to the external wall is about 6.5m.

Having googled it - I think optimum distance is about 2-3m accounting for the bends - so I don't know if the extract hood will work at 6.5m.


The only other option is to take it vertically through the chimney breast, but that would be a 10meter duct - and I've heard that there is a chance that condensation will cause oils from the extract to drip back into the cooker hood.

Any thoughts about which is the better of two not so great options?

Thanks!

 

[jj4091]

Your horizontal option seems to me the lesser of the 2 evils as venting it up a chimney that has no liner may cause you damp issues from condensation.

 

[dodgem]

I was thinking if I vented up into the chimney I would line it with a 150mm or 90 x 220mm duct.

I just don't know which one will have a more powerful extract.

Also if there will be an issue with grease dripping down in the vertical chimney option.

 

[sparkwright]

The horizontal option sounds better than the vertical option.

 

[ericmark]

My cooker hood is horizontal, however rarely used, with the old hot plates with an electric hob it was common to see the pans boiling away, but with the induction hob with the auto boil/simmer settings this is less common, rarely are pans boiling away, and with electric there is no exhaust fumes to be extracted. Gas however is very different, even the gas burning produced water, so the hood is essential, mine does have a filter, but so rarely used being electric never needed to clean, gas is a very different story.

Be it vertical or horizontal it needs to be cleaned every decade or so, even with electric induction, so easier to access horizontal so would go for horizontal, but never used gas cooking, I see it as dangerous having naked flame, so even if it can be used better with a wok, still would not have it. At least now we have induction cookers.

 

[dodgem]

Not sure I made it clear in my opening post - if I vented up in the chimney I would still use a cooker extract hood and flue liner.

But - yes - horizontal ductwork is the most practical - although uglier - of the 2 options (as will need to plasterboard the ductwork into the ceiling).

It's just annoying as seems the chimney breast was used for cooking in victorian times with the remains of an iron stove...

 

[Taylortwocities]

If up in the ceiling is the option, then make sure the joist run is on the direction you need!

If you have to go vertically you could install a condensation trap. Eg

Missing Cookie

Don’t worry overmuch about duct length, cooker extract fans are usually much more powerful than the weedy things that are put in bathrooms.