Is the shiny side of aluminum foil suppose to be on the outside of wrap for heat?

Answer 1

Technically, there is no inside or outside to foil, but, one would suppose that the shiny side of the foil would actually be the INSIDE, because the shiny side would reflect the heat waves, such as a mirror reflects light better on a shiny surface.

I use the shiny side to cover pie crusts when I don't want them to burn because it reflects the heat away from the covered area. When I'm roasting or baking I put the dull side out because it helps the food absorb more heat and cook quicker-but only a little bit. another questin you should think about is what makes aluminum foil

Another point of viewThe folks at Alcoa (the Aluminum Company of America) will tell you that it doesn't make a difference which side is in or out when using foil - unless you are interested in looking at yourself in it. Infrared radiation - heat! - works equally the same with either side. (You can't see infrared directly.) Oh, and the "amount" of visible light (light above infrared) that is reflected by both sides is almost identical, too. It's just that the "dull" side scatters it more than the "shiny" side, which has a smoother surface and acts more like a mirror. If you have a preference, by all means continue. But not because physics dictates it. It does not.