Chimneys.. again.

from doing what?

jim

Ventilating the airspace that is now enclosed between the original brick stack and the new liner, presumably.

Hmm, surely a wood stove needs to draw air for the fire from somewhere - can't the chimney airspace be used for that (as presumably it'll gain a bit of pre-heat from the exhaust going up within the liner)?

Jules et Jim aident - ca m'amuse!

I've never seen a solid fuel stove that doesn't just draw air in from the room. Although you can get a fireplace which takes air in from under the floor - the Baxi Burnall. We used to have one in a previous house, it worked excellently.

It's quite common on the continent to install ducts through the air space in the chimney and blow heated fresh air round the house as a form of central heating.

pourquoi?

Yes. First paragraph:-)

According to my *Collins complete DIY* I think the answer is yes.

I see Screwfix do a plastic 70mm soffit vent but my core drill is 78mm.

For anything over 4.9kW you have to have an air vent so I have put a duct through the hearth and fitted an extra under floor airbrick. My particular log burner comes with a ducted air option.

regards

are we assuming the chimney was airtight in the first place? personally I wouldn't bother - what would it prevent? some heat from the liner will keep it warmer and dryer (relatively) anyway - venting it would add what?

cheers jim

I'm pretty certain they tipped a ton of insulation stuff down between our liner and the chimney...

insulate. That way the crud stays hot until the top and leaves?

passim)

May I ask what manufacturer?

That's the other way of doing it. Double liner then tip insulation in.

The OP has "double liner insulated with pre-formed rockwool sleeves"

Personally, I think I'd tip more insulation down - improve the draw.

how's that work then? jim

Clearview 650.

regards

Hmm... Vermiculite bonded with cement seems a bit permanent to me. With a struggle I can get my flue out again.

I'm going to stick a couple of vents in anyway. Nobody has suggested any likely problems.

I think the draw is ample as you can warm your hands in the flow of centrally heated air!

regards

It's not, it has the consistency of of a puffed rice cake when I've mixed it (using high alumina cement that's good for 700C) but I cannot remember the mix, probably about 10:1.

AJH

Yes, but you wouldn't be able to pull a 6.5m long flue out again. I hope I never need to but things have been evolving here since Victoria.

Also, S/S liners do not come with any sort of life warranty.

BTW. I have had a digital survey done of the old barn and taken out the concrete floor. The next problem is to get a steel frame designed without creating unaffordable architects/structural engineers fees:-(

regards

why use cement? where's it all going to go? ours are just loose vermiculite - when time comes to change the liner - get a large dumpy bag, open the soot door and stand well back!

what will your vents add to the sitiuation - seems like extra wasted effort and expense to me...

Anyhow enjoy!

Jim