Tue, 14 Jul 2026 16:53:27 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43717#Comment_43717 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43717#Comment_43717 Sun, 18 Jan 2009 20:36:22 +0000 Shepherd This is where the explanation gets a bit complicated. It is a lean-to conservatory, but is not leaning directly on the house wall (because the bungalow is too short). What we are doing, is basically mounting what would be the wall plate on pillars, and so the peak of the roof, will be a few inches higher than the house gutter. (We are also re-doing the house gutter to be a large gulley gutter that butts between conservatory "wall" plate and the house eaves.) This means that the beams which sit on top of the "wall" plate to support the polycarbonate, will have an air gap in between them. (So there will be a series of air gaps bounded by wall plate at the bottom, roof beams at either side, and polycarbonate at the top.) Obviously we need to fill this in to complete the conservatory insulation - but what we want to do is turn these into vents - but vents that are well sealed against water ingress when shut and form a good insulating barrier for winter. An ideal design would be something like those metal covers for the outdoor side of an airgap - series of vertical slots and you use a handle to slide a plate across to open or shut the gaps. We could use those, but it would provide no insulation at all. Is there a thick, insulating version of such a vent?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43720#Comment_43720 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43720#Comment_43720 Sun, 18 Jan 2009 22:03:16 +0000 Davipon https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43721#Comment_43721 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43721#Comment_43721 Sun, 18 Jan 2009 22:07:01 +0000 Nick Parsons https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43730#Comment_43730 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43730#Comment_43730 Mon, 19 Jan 2009 08:32:03 +0000 Shepherd
Ideally we will be extracting heat into the house at cooler times of year, but middle of the summer there will be surplus, and we wanted something simple and mechanical to sort that.

Also in our planning pipeline is a big array of hydronic solar panels at ground level sitting on top of an underground thermal store - off to one side of the conservatory. So we may finish up extracting heat from the conservatory in summer, into the store, but it would have to be transferred from air to water for storage, so not simple. If anyone does have any suggestions about the mechanics of harvesting heat from the conservatory to the thermal store, we would be interested.

The conservatory is also to do with growing plants - there will be a small seating area in there, but the main purpose of it is growing things and the additional use of being a back porch at one end where we leave muddy wellies. So there won't be many places to put solar panels of any sort, where they wouldn't be shaded by what hopefully will be lots of lush growth ]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43769#Comment_43769 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43769#Comment_43769 Mon, 19 Jan 2009 13:48:02 +0000 howdytom
sounds interesting, but why polycarbonate ? glass is about the same cost and would last you a lifetime. a company called Exitex in Ireland (i think that's the spelling) do all sorts of fixings for glass and PC. google it.

Tom]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43787#Comment_43787 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43787#Comment_43787 Mon, 19 Jan 2009 15:40:58 +0000 CWatters Posted By: ShepherdWhat we are doing, is basically mounting what would be the wall plate on pillars, and so the peak of the roof, will be a few inches higher than the house gutter. (We are also re-doing the house gutter to be a large gulley gutter that butts between conservatory "wall" plate and the house eaves.) This means that the beams which sit on top of the "wall" plate to support the polycarbonate, will have an air gap in between them. (So there will be a series of air gaps bounded by wall plate at the bottom, roof beams at either side, and polycarbonate at the top.) Obviously we need to fill this in to complete the conservatory insulation - but what we want to do is turn these into vents...

This just sounds like a problem waiting to happen. What happens when the gutter fills up with snow?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43805#Comment_43805 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3327&Focus=43805#Comment_43805 Mon, 19 Jan 2009 16:55:45 +0000 Shepherd In an ideal world we'd prefer glass, but we were going for polycarbonate because of the weight. Each roof section would be 1m wide by 2.4 meters long (and approximately ten sections in the roof).

Using http://www.matweb.com/tools/weightcalculator.aspx I did a calculation based on purely two sheets of glass of that area, 4mm thick and that came to just under 42kg per section. (Then add the weight of the double glazed section frames.)

Looking at manufacturers data for triple wall polycarbonate, 16mm thick, the same area came to 6.5kg.

The slope of the roof, due to restrictions of the site, will be about 12 degrees (best we can manage, would like more).

We are also in an exposed area so will have quite a lot of wind loading on the roof. Possibly therefore want to have some form of special higher strength glass or greater thickness - don't know, didn't look any further into it. Like the polycarbonate box section support mechanism too.

CWatters
Snow, yes, forgotten snow, snowed today, hmmm. These theoretical vents did also have theoretically good sealing, but going off the idea. Starting to think about roof lights, maybe of the sort of caravan roof design, right at the apex of the roof. As in the hinges are under the apex cap of the roof, and the window slots down over a raised box frame. So much better roof lights than our last conservatory.]]>