venting an extractor fan up the chimney?

mel o

Registered User
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We're hoping to move our kitchen into the dining room and I wanted to sit the hob into the chimney breast and vent it up the chimney. The chimney is on the party wall we share with our neighbour and there is no external wall in this room to run the pipe thingie through. There used to be a fireplace in the bedroom above but we had it blocked up years ago.

Has anyone done this and had problems? I was at a kitchen place out in Ranelagh and the man there (who seemed to know his stuff) said it can be a problem cos the hot air is kept down by the cold air in the chimney so the extractors get greasy very quickly. I'm not sure what to do now.
 
Would imagine unless a flue liner was used it would also lead the excess condensation in you chimney which will eventually cause dampness into the house through the breast
 
AFAIK, you have two choices :

  1. Use a recycling cooker hood with a charcoal filter (no external vent)
  2. Vent out the back via a pipe / hose between the kitchen ceiling and the bed-room floor.
The kitchen-man and DGOBS are right; venting to the chimney is unlikely to work satisfactorily.
 
Thanks for the replies, I felt that kitchen man knew what he was talking about. Do you happen to know how effective the charcoal filters are?
 
I would echo DGOBS and mathepac advice.

The chimney is a non runner. when the hot air leaves your extraction fan it would cool rapidly as it rose through your cold chimney. Hot air rises, cooler air turns from water vapour into water. this water flows back down your chimney and causes unseen/untold problems in the future.
 
Thanks, Davyjones, I think I'm starting to accept it ( although it's not what I really wanted to hear!). Do you know anything about charcoal filters, are they any good, or any other alternatives for a room that has no outside walls? I don't think we can run a pipe through the floorboards of the room above because the roof of the lean-to extension comes up to about 20cm under the window sill of that room so the pipe would come out in the living part of the room!

I'm just not imaginative, I'm sure there's a solution but I can't think of one...
 
Charcoal filters seem to be good and ideal solution to your problem.

Is there anyway that you could get a 4" pipe run from appliance to outside?maybe boxing in around it? Probably not worth the hassle.

you could possibley make the chimney thing work but it would cost a small fortune. Lining chimney with maybe double skinned liner, it's insulated so isn't as cold inside and maybe stick another fan somewhere to get air out faster, given it less time to cool down. This way would be very expensive.