Tue, 19 Dec 2023 08:32:32 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301688#Comment_301688 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301688#Comment_301688 Mon, 22 May 2023 09:31:32 +0100 WillInAberdeen
A disused masonry chimney has a disused spiral flue liner in it. The inside of the flue liner is ventilated at the top through a chimney cap, but the space inbetween masonry and flue liner is not ventilated, there is damp that might be condensation.

Other disused chimneys have airbricks in the old fireplaces, but aside from the air leakage problem, there is no access to this fireplace from the inside, or to remove the spiral liner or infill the chimney.

I am thinking of putting airbricks top and bottom of the masonry chimney to ventilate it out through the outside wall, then IWI. Anyone got experience/pros/cons/alternatives?

Thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301691#Comment_301691 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301691#Comment_301691 Mon, 22 May 2023 11:36:46 +0100 Peter_in_Hungary
Best option would be to remove the chimney down to ceiling level and then cover with the same insulation as in the loft.

Air bricks in the fireplace help as with the other disused chimneys but these also create a big thermal draft with accompanying heat loss.

If you can't take them down another option would be to fill the chimneys with insulation up to ceiling level and put a air brick in above the insulation level.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301692#Comment_301692 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301692#Comment_301692 Mon, 22 May 2023 11:48:47 +0100 WillInAberdeen
Anyone tried ventilating a chimney to the outdoors? I half suspect there is a reason why they usually are ventilated through airbricks inside the old fireplaces but can't figure out why that's better than ventilation to outdoors.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301693#Comment_301693 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301693#Comment_301693 Mon, 22 May 2023 12:57:14 +0100 Mike1 Posted By: WillInAberdeenI half suspect there is a reason why they usually are ventilated through airbricks inside the old fireplaces but can't figure out whyBecause the difference in internal-external temperature creates a stack ventilation effect. That is, the warm internal air is less dense and therefore more buoyant and will rise through the chimney.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301696#Comment_301696 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17848&Focus=301696#Comment_301696 Mon, 22 May 2023 17:01:06 +0100 Jonti