Wednesday, January 24, 2007

The Grand Conservatory Project: space heating from the sun

Completed clawdd (Welsh word meaning earth-cored) wall end in the garden and the start of the excavation
Completed wall end in the garden and the start of the excavation

Construction - mostly destruction at this stage - is underway. I've been nipping out for a few hours most days when the gales and heavy rain stop to remove a rockery and completely rebuild a clawdd wall. This is to make space for The Conservatory which, we hope, will result in a much warmer house, partly because of its insulating properties on the solid stone wall of the exposed front of the house and partly because I intend to duct heat captured inside the conservatory into the usually-cold inside of this traditional farmhouse. I hope the walls will act as a heat store. That's the idea anyway. Any ideas for simple control devices and fans welcome! (Please add a Comment.)

Now that the rockery and wall are 'rearranged', there's a lot of heavy work ahead shifting barrowloads of soil and rocks. I've tried to arrange things so that I don't have to move stuff twice. So the biggest boulders - some of which I could only just manage to slide or roll - will form the basis of a new rockery in the middle of the garden, burying the existing ugly concrete path which with dozens of barrowloads of soil. So most of the excavated materials aren't 'waste'; they're useful in a new and more attractive context: a rockery in the middle of a single lawn no longer bisected by the ugly path to the gate which was never used anyway.

The indespensible water level, one end attached to the building, the other being free to check excavation depth
The indespensible water level, one end attached to the building, the other being free to check excavation depth

Now that I have the detailed drawings of this conservatory from its manufacturer, Val and I set up a datum level which is based on the distance between the base of the upstairs windowsill and the top of the conservatory 'wall plate': the highest timber of the frame which is bolted to the building. I have to leave space below the sill for flashing to go in or it will leak. That done, we checked with a water level that both sills were the same height (they weren't) and measured down to a point which is 1 metre above the finished floor level, marking this with a line. I then attached one end of water level to the wall. This means I can attach the other end of the level to a measuring post whose length below the level is at precisely the depth below the finished floor level that I need to excavate. That is 1.2 metres for the path which I will make along the front of the new structure, allowing for a dampproof course to be made at floor level in the dwarf wall which I will build to support the conservatory frame and glass. The glazing, by the way, will be low-e glass, double glazed, with a U value of about 1.3. Pretty good.

Excavating is the way it's going to be for a few more days if the long-awaited colder, drier weather persists. Then the fun starts! I have to break up the existing concrete 'patio' where the conservatory structure is to be built. This is a hodge-podge of patches of different concrete and different levels and so, unfortunately, has to go. Will I do the breaking by hand (sledge hammer) or hire a hydraulic breaker? I think the latter! But do watch this space...

1 comment:

Derek said...

Sounds like a pretty good plan - provided you get enough sun on your stones.

Could you put up a map of the Grand Conservatory Project?
Can't quite see what you're doing.

I recall that Amory Lovins has a place some 7,000ft up in the Rockies which draws 100w of power in the winter and produces more than that in the summer. He also makes use of mass (rocks) to even-out the heat of the day/night. Being double (or triple)-glazed probably helps too!

Apparently it's sufficiently warm for him to grow tomatoes! :-)