19 Oct 2012: The large window will have a solar shader, and initially, I can re-fix up the mirror-shader that was made for the previous window. That worked fine for the winter. For Summer use, we need a more cantilevered shader, and I planned a triple louvre shader cantilevering about 700-800mm. I have a present method of making louvres that keeps the aluminium flat, and has a stiffening rib behind. The outward facing surface can be mirrored with Mylar. I want the outermost louvre to tilt fully so it directs sunlight into the window, but the two nearer the wall to tilt only slightly.
|After doing some sketches, I devised the principles of tilting the first two and having a reciprocating tilt for the third. As it is not clear what the dimensions would be for this to work smoothly, the only way to progress the design was to make a working model. Even without dimensions, the mechanism would reveal itself.||This model, in cardboard, is about 50% scale and the third louvre needs a cranked or angled tilting lever. this is a good way to establish if the principle works. It does.|
|This is in the Winter setting. With the cranked lever above the right hand louvre, it is possible to get all the louvres parallel in the winter and the summer setting. The outer faces of the louvres face out correctly. The right hand louvre has a mirror finish and reflects sunlight onto the window. The left and middle face the sky and reflect daylight onto the window.||The problem with the reciprocating louvre is that there is no useful middle setting. If I make them to beall parallel, there would be some in-between positions.|
The Summer setting is shown here, and it is really 'neat' the way the third louvre flips as one moves the control lever.
If the louvres remain one-sided like my existing one on the previous window, then this would be the best solution, especially if the outer one is a bit larger.
I have also managed to find some mirror finish aluminium (but only 0.5mm gauge) and I am weather testing a piece of it in the front garden now.