[Les Paul]

I've had a 10x15 tempered glass aluminum frame for 3 years. I think more than anything it's the number of sunny days you have per year that makes it feasible. I live in the northern panhandle of Texas and surprisingly we have been in the teens, single digits, and below 0 this year. We have thermal curtains that retain the heat below the upper panels that can be opened and closed very easily. I have 20k btu gas heater. Gas is cheap here so it works well. We have the entire north side and ends with industrial size bubble wrap between panels, which acts as pretty decent insulation. Prior to this winter we had one panel that had slotted windows. We would tape over the window slots but it still leaked more than we realized. This year our heater kept kicking off due to low Oxygen. I ended up running a fresh air intake outside and have had no more problems. Winter is especially nice to hang out in the greenhouse with close to 100 plants. Humidity never goes below 50% so it's nice for the winter dry skin seasonal thing.