The default was set at 40 and I reset it to 38. After being closed up all night it got as low as 36 if I remember right. I didn't try to go as low as it would, wish I would have just so I would know.
Schmalts, I'm helping my nephew get set up with optics. Thinking about Theron Wapiti LT 8x32. Also a rifle scope. Will be in touch.
Sounds good, give me a call. I have a project I may do but need to get down to 20f or lower. I might use a central air unit for the power plant.