Frank I really like the use of the pop cans and look forward to some of the information you'll be able to gather on the collectors. I would have liked to have seen you maybe use different collectors for each side since both sides seem to be of equal area and the difference, if any, of each collector could be discovered.
I know you were just using what you had available lying around, a rarity on this site<grin>, but I was thinking one side could have been a single layer of TuffR or other foamboard(I think I see some pink foamboard in a few pictures)painted black. It seems this would have allowed you to cut a simple door/viewing port with a piece of tape for the hinge for those occasional glimpses outside and may have offered a better R value. Just some thoughts... but I still find the pop cans a very neat idea plus it looks like it was a pretty fun project. Nice work!
