Sun, 31 May 2026 02:52:47 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28871#Comment_28871 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28871#Comment_28871 Sat, 02 Aug 2008 22:08:20 +0100 mike4africa ]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28875#Comment_28875 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28875#Comment_28875 Sat, 02 Aug 2008 22:54:09 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28878#Comment_28878 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28878#Comment_28878 Sun, 03 Aug 2008 01:59:57 +0100 mike7 Tony - why won't it work?
Cheers
Mike7]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28884#Comment_28884 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28884#Comment_28884 Sun, 03 Aug 2008 09:42:02 +0100 mike4africa ]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28886#Comment_28886 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=28886#Comment_28886 Sun, 03 Aug 2008 09:48:28 +0100 tony
Why not design the job so you dont need heating if it is possible up here it must be able to be done where you are -- also it will be cooler in summer too.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=29172#Comment_29172 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=29172#Comment_29172 Tue, 05 Aug 2008 13:28:42 +0100 mike4africa
Temperature in winter goes below -10 so it might not be possible (SW France).

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=29233#Comment_29233 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=29233#Comment_29233 Tue, 05 Aug 2008 18:12:02 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=30613#Comment_30613 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=30613#Comment_30613 Tue, 19 Aug 2008 15:45:15 +0100 orangepippin https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=30614#Comment_30614 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=30614#Comment_30614 Tue, 19 Aug 2008 16:01:44 +0100 TheDoctor
incidentally, if you spec the right fire, you wont need UFH.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=31470#Comment_31470 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=31470#Comment_31470 Sun, 31 Aug 2008 03:47:42 +0100 Terry
before all that, maximise design, insulation and airtightness as suggested above. This one off cost limits on-going energy costs to heat.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=31482#Comment_31482 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=31482#Comment_31482 Sun, 31 Aug 2008 13:40:35 +0100 mike7 Posted By: Terryyup, open fires lose something like 80-90% of the heat straight up the chimney. .

Open fires get a very bad press here, and usually for good reason, but I suspect it need not be anything like so bad as Terry's figure of 80 - 90% loss. Most open fireplaces appear to lack any design at all from the energy efficiency point of view. Some basic guidelines I suggest:-

1. Make the hearth as low as you can, below floor level if possible.This allows you to ....
2. Make a hood as low as possible above the hearth. This means only the coolest air in the room will supply the chimney draught, leaving higher warmer air in the room.
3. Make the hood as small as possible to ensure gathering smoke from the fire, but no bigger.
4. Place firewood upright, leaning back at about 60 degrees and light about 15cm below top. It burns much cleaner this way, and allows a smaller hood.
5. Incorporate a baffle in the flue or hood to restrict the draught to the minimum necessary plus a bit. Make it easy to adjust - it has amazed me just how small a vent is needed for an open fire well alight.
6. Have a fireclay or some such non-metallic fire-back to help maintain a high temperature in the combustion zone. Make it V-shaped rather than flat against the wall so that the logs tend to lean in together.
7. Don't bother with supplying outside air direct to the fire - it is difficult to do this without generating turbulence which makes gathering all the smoke/exhaust more difficult, and if you attend to the above items, the draught flow will be no more than you would want for airchange anyway.

It works for me. Having declared my vice, I wonder how many other closet open fire burners there are on this forum. My excuse is that the fire is occasional and would not justify the cost of a stove where it is.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=31486#Comment_31486 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2268&Focus=31486#Comment_31486 Sun, 31 Aug 2008 15:17:46 +0100 simeon
The point about thermal efficiency is that the greater the efficiency of your heat source the more likely that your wood supply is sustainable.

Thermal efficiencies of open fires are low. 15% is the accepted figure but can actually become negative (for the house as a whole) especially with low outside temperatures.

There is some good information at this site:

http://www.mfe.govt.nz/publications/energy/warm-homes-heating-options-phase1-nov05/html/page4.html

Cheers]]>