Paul Roue

From what I've read you want your glass roof 90 degrees to noon sun at winter solstice. That would seem to be an incredible amount of volume to heat. I was thinking about sloping the glass roof at 19 degrees... oh an important detail, I would excavate 5' below grade to capture ground heat so the roof would start at ground level. The exterior mirror wall would also start at ground level.

Yeah if I were considering this for as a financial investment to sell produce... It would suck. I was thinking more along the lines of being more sustainable by having the ability to have fresh produce year round and also quality of life improvement. Today our high temp was -17F. To be able to go in where it is warm and moist and exploding with green on deary winter days... hard to put a $$ value on that.

Paul

Would I get an added benefit if I put a wall of mirror, either outside or build it as a lean-to structure with the mirrors on the inside? I've not seen it anywhere and I can't be the first person to consider the idea.

The details: I am in a northern climate, at winter solstice the sun is 19 degrees above the horizon at noon and above the horizon for about 8.5 hours. That isn't a lot of daylight if I want a year-round greenhouse but my thought is that if I put a mirror wall on the north side I would dramatically increase the amount of solar radiation the plants would get and they would be more productive. I am thinking an external wall would be better as there is less volume to heat.

Paul