I'm trying to trap heat using a cardboard box and saran wrap. I know cardboard's not going to keep as much heat in, so I plan on sealing it with some caulk and maybe lining it with some styrofoam. Do I line the sides/styrofoam with aluminum foil or paint it black to bring in more heat?
Please just think about it! Common sense is enough to figure out how to use those materials to maximize the energy entering the box and minimize the amount leaving the box.
paint the aluminum black and wrap it, unless it is windy, then try painting the styrofoam, but don't use spraypaint on the styrofoam, it will melt
The aluminium will reflect the heat back into the box - so you could line the box with that too. On the outside, it's tricky, because whilst black does absorb heat most effectively - it also releases it quickest too. But if you've got the aluminium on the inside, as well as styrofoam (or polystyrene works well too) i'd go for black on the outside.
