Using a Chimney as an Extractor Vent (Kitchen)

Bes

Bes

Bes

Soldato
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Hi,

My ground floor flat has a fireplace/ chimney breast in the middle of the kitchen/ dining room.... It's a bit odd- basically where the old owners have knocked the kitchen through into the dining room, but not removed the fireplace.

My idea is to put a worktop island where the fireplace currently stands, and if required, have some kind of support (pillar/ column) running up to the ceiling. Assuming this can be done, is it conceivable that the existing chimney 'hole' in the ceiling could be used as an extractor flue for a hob? Also is there any particular disadvantage to having the hob on an island in the middle of the kitchen/ diner? I can imagine having no 'splash back' for grease from cooking would be an issue?

Thanks
 
structural issues aside (I can't see how it would work) I think you'd need quite a meaty fan to push damp air all that way.

You would also need some sort of condensate trap at the bottom of whatever liner you use (you would need a liner as the air going up is going to be very damp) as some of the water will condense and run back down. If thats in the middle of the room I dont see where you can drain that.
 
You own the ground floor flat? Is it leasehold?

If there are other flats in the building I'd check that you don't need permission from the leaseholder before making structural changes, especially as what you're describing may impact the flat above, plus you may find you don't own the whole chimney stack (e.g. what happens if the flat above decides to remove the stack).
 
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Bes said:
Hi,

My ground floor flat has a fireplace/ chimney breast in the middle of the kitchen/ dining room.... It's a bit odd- basically where the old owners have knocked the kitchen through into the dining room, but not removed the fireplace.

My idea is to put a worktop island where the fireplace currently stands, and if required, have some kind of support (pillar/ column) running up to the ceiling. Assuming this can be done, is it conceivable that the existing chimney 'hole' in the ceiling could be used as an extractor flue for a hob? Also is there any particular disadvantage to having the hob on an island in the middle of the kitchen/ diner? I can imagine having no 'splash back' for grease from cooking would be an issue?

Thanks
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I doubt you'll find any domestic extractor that's capable of pushing that big a column of air, assuming you're intending to push the air up to the top of the chimney that comes out several floors above.
 
I own a share of the freehold with the chap above me. There are 2 of us on the freehold.

No biggie if it doesn't work/ isn't do-able, but thought it was worth looking into!

Lumeycom - When you say 'structural issues aside' - what are you referring to specifically? Just removal of the fireplace? I've had some other tradesmen come around for various things (and I have a friend who is a structural engineer who has seen photos of the room), and no one has said that they don't think it's do-able.

Cheers
 
Steampunk said:
I doubt you'll find any domestic extractor that's capable of pushing that big a column of air, assuming you're intending to push the air up to the top of the chimney that comes out several floors above.
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Plenty of people do it remember the column isn't static you've got thermal convection the air your extracting is pretty hot and the chimney effect if you have any air movement over the top and if you use something like the fan I linked to a significant quantity of the grease before it enters the chimney as said I would never consider this with an unlined chimney 100 years of soot and filth mixed with a load of cooking grease and steam sounds like a recipe for disaster!

another product worth considering for this:

http://www.appliancesdirect.co.uk/p/elb-80-rm/elica-elb80rm-72.4cm-canopy-hood

External motor and an extraction rate of 1200 m3/h that is a pretty beefy piece of kit when you consider cheap extractors only manage a couple of hundred m3/h are are considered ok for 5m of ducting!
 
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I would worry more that removing the chimney stack on the ground floor would necessiate removal of the whole stack, or you're going to end up with upstairs' fireplace in your kitchen! There's going to be a reason the previous owners didn't remove it.
 
WillyNelson said:
I would worry more that removing the chimney stack on the ground floor would necessiate removal of the whole stack, or you're going to end up with upstairs' fireplace in your kitchen! There's going to be a reason the previous owners didn't remove it.
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You can remove a lower section of the chimney stack provided you support it with the necessary steels etc it happens all the time.
 
WillyNelson said:
I would worry more that removing the chimney stack on the ground floor would necessiate removal of the whole stack, or you're going to end up with upstairs' fireplace in your kitchen! There's going to be a reason the previous owners didn't remove it.
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I think the reason they didn't do it is because it requires extra structural work to support the stack above it and I think they just didn't want to pay for it. The rest of the old kichen wall was just a partition. Like I said I am happy to have a vertical pillar or beam left there, as there will be an island worktop where the fireplace is anyway.

I did consult a few impartial people before I purchased the property and no one raised any particular concern that it could not be done. Everyone did say it would definitely require additional structural work to make sure the above stack was supported, but I was expecting that.

RE the extractor thing, it sounds like more trouble than it is worth at the moment. Lining the chimney will cost a fortune I bet! Would anyone know the rough cost?

Thanks
 
Bes said:
I think the reason they didn't do it is because it requires extra structural work to support the stack above it and I think they just didn't want to pay for it. The rest of the old kichen wall was just a partition. Like I said I am happy to have a vertical pillar or beam left there, as there will be an island worktop where the fireplace is anyway.

I did consult a few impartial people before I purchased the property and no one raised any particular concern that it could not be done. Everyone did say it would definitely require additional structural work to make sure the above stack was supported, but I was expecting that.

RE the extractor thing, it sounds like more trouble than it is worth at the moment. Lining the chimney will cost a fortune I bet! Would anyone know the rough cost?

Thanks
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Lining the chimney isn't that bad a stainless steel liner isn't that expensive then you just need someone to install it which again isn't highly skilled think ours cost about £600 but was more expensive as it is an open fire so needed a more heavy duty liner.
 
Sorry I should have been more specific.. I meant that I've no clue about structural issues hence why I didn't pass comment on them.

And yes you can move a column of air that high no issues but you'll still have condensation issues in whatever you line it with, there isn't going to be enough heat going up there to keep it suspended and it will condense and run back down.
 
Thanks everyone.

To be honest, it sounds like a lot of hassle when compared to counter- top extraction systems that pop up. I don't like the idea of lots of condensation in the stack, lined or not.... Also I guess in order to line it he might need to go into the neighbor's flat too?
 
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Bes said:
Thanks everyone.

To be honest, it sounds like a lot of hassle when compared to counter- top extraction systems that pop up. I don't like the idea of lots of condensation in the stack, lined or not.... Also I guess in order to line it he might need to go into the neighbor's flat too?
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Nah, they'd drop a liner down just your flue.

Not sure you'd need a stainless liner either - they're only used for burners typically. I'd presume it would just be a plastic\flexi liner.

I agree btw - sounds like an over-complicated solution.
 
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