Without heating water, I think you've removed the freezing and high temp issues, I'm not sure why you want to complicate something and reduce efficiency by trying to heat air and turn it around to heat water and then try to heat air again.
I like this design and the same author has tried other less successful designs. Read up on this one and see if you can use the glass you've collected in a similar way.
https://www.builditsolar.com/Experim...r/Building.htm