According to the EPA
Reflective insulation, is type of attic insulation that can help improve the comfort of your home while helping to reduce your energy bills.
Reflective insulations perform a function that is similar to that of conventional insulation, however they differ in the way they reduce the heat flow into your house. On a sunny summer day, solar energy is absorbed by the roof, and heat is radiated downward toward the attic floor. When a Reflective insulation is placed on the attic floor, much of the heat radiated from the hot roof is reflected back toward the roof, thereby reducing the amount of heat that moves through the insulation into the rooms below the ceiling.
