Comfortboost is a top-of-the-line next generation underlayment specifically designed to improve a room's.overall comfort by combining VinylTrends' advanced acoustical foam with radiant energy reflective , technology to provide a comfort that you can actually "feel". "Feel the Difference" - How it Works? Up to 93% of heat/air conditioning lost through your floor is primarily due to the penetration of Radiant energy (compare this to energy lost by Conduction at only 7% and losses through Convection at 0%). The fused aluminum film prevents radiant energy from penetrating down, reflecting it back into your home where it is absorbed in the form of heat or air conditioning energy. This relationship of reflection and absorption is what makes Comfortboost provide a "comfort" that you can really feel.