Greenhouse glass question

My DH and I were just given 50 old double-paned sliding glass doors by a construction friend who is remodeling an apartment complex. We are wondering if the glass is suitable for a greenhouse. Here are the specs from one pane that still had a label:
U factor = 0.34 (U.S.I.P.)
Solar heat gain coefficient .058
Visible transmittance 0.58
Low emissivity
Would any of these specs preclude us from using this glass for greenhouse construction?

I don't think so. The U factor is 1/R value. This means that your glass has an R value of 2.9, which is excellent, twice as good as a typical twinwall poly GH, and therefore half the heat loss.

The VT is a little lower than you might like at 0.58. I believe that these wavelengths are, more or less, the PAR, photosynthetically active radiation, and I suppose you could say that this would be like having 42% shade cloth. It might be a problem in the winter, depending on what you want to grow. Double layer polyethylene, commonly used in greenhouses, has a PAR transmittance of < 0.80, just for comparison.

SB

Thanks for the info, SB. Interesting about the PAR value. The 42% shade cloth effect will come in handy in the non-winter months, for sure. If it proved to be too shady during the winter months, we might be able to add some lights. We're really looking forward to building this greenhouse next year.

my gh is all windows and it works great!!!

Wow - that is a really nice looking all-glass gh, notmartha. Fee free to post more picts of it. :) Did you frame up each pane of glass separately and then attach them together? And what kind of heating and cooling do you use? We were wondering if we should put solar panels on the very top of the greenhouse to provide heat in the non-summer months. (We had morning temps of 28F this past weekend - brrr.)