Green Building Forum - Cooling Sat, 18 Apr 2026 10:54:11 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Cooling https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308740#Comment_308740 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308740#Comment_308740 Thu, 03 Jul 2025 11:30:35 +0100 Dominic Cooney The only decision then is whether use the polished concrete floor slab (the finished floor throughout the building) as the cooler, or to connect it to the MVHR system.
I have asked them for advice.]]> Cooling https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308741#Comment_308741 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308741#Comment_308741 Thu, 03 Jul 2025 12:14:09 +0100 Mike1 Posted By: WilllnAberdeenMike, when you boost the humidity in the extract duct, you have to read diagonally up and left, up the black iso-enthalpy lines (or wetbulb lines).That's a good point - thanks; I'll have to go and revise my physics...

Posted By: Mike1check the capabilities of MVHR items such as thermostats, which must be capable for operating that low
Also consider the MVHR pipe spacing. I asked the M&E engineers to look at retrofitting cooling to the UFCH on a commercial project some years ago, but they calculated that it wouldn't be sufficiently effective at the 250mm pipe spacing - it would have needed 150mm.

There's a big difference between the commercial and domestic, but it doesn't cost much to add pipe at build stage, so probably worth doing.]]> Cooling https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308742#Comment_308742 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308742#Comment_308742 Thu, 03 Jul 2025 15:30:40 +0100 Dominic Cooney Cooling https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308764#Comment_308764 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308764#Comment_308764 Sun, 06 Jul 2025 12:55:12 +0100 WillInAberdeen
- Cooling the UFH is very pleasant if you have bare feet or sit on the floor. But cold doesn't rise, so ufh doesn't really cool the room air that much. If strong sunlight through a window onto the floor is overheating the house then cold ufh tackles this, shading would be better still.

- cooling the Mhrv is the opposite, but mhrv air flow rates don't have much capacity to carry heat or cold, so will be limited to a few hundred watts of cooling output. Might not be worthwhile and might cause a heatpump to short cycle.

-radiators combine the worst of both, the cold water just sits in the bottom few inches of the rad.

- fan coil convectors are the best for cooling as they blow cold air around the room]]> Cooling https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308849#Comment_308849 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18313&Focus=308849#Comment_308849 Sun, 20 Jul 2025 19:49:45 +0100 Mike1
Do let me know if you spot any more errors...

As before, remove the .txt from the end of the file.]]>