A material that reflects radiant heat, typically a foil-faced or foil-like material used in roof systems. Used properly in some climates, it can reduce cooling requirements but has no positive effect on heating requirements.
A layer of metallic foil placed on the back of roof decking or attached to the beams just below the roof to reduce heat flow from the roof into the attic, thereby keeping the house cooler. To be effective, a radiant barrier must have its reflective surface face an air space.
a layer of aluminum foil placed in an airspace to block radiant heat transfer between a heat radiating surface (such as a hot roof) and a heat absorbing surface (such as conventional attic insulation at the ceiling level)