I just bought a radiant barrier to install in the attic to keep the heat out of the attic. I was thinking about this for the summer, but its already starting to get cool where I am and was wondering... SHould I wait to install the radiant barrier until after winter so that the sun will help heat the home from and through the roof and attic during the winter? Or will the radiant barrier help keep the heat inside the home that I produce from my furnace? Thanks!