Originally Posted by CypherEnigma
This doesn't really make sense to me. Shiny foil reflects light not heat. I don't think that shiny foil down will reflect heat back down. There really shouldn't be a huge a difference between the conductive properties of the different sides of the foil.(not trying to argue here, just never heard this before)
OT: I use two layers of foil and out of habit I put the first one shiny side down and the second one shiny side up. Just habit at this point not sure if there really is a noticeable difference between the sides of the foil.
light creates heat.
Just like when I used to burn ants with a mirror when I was a kid.