This hot roof radiates heat down to your insulation and allows the heat to gradually enter your living space, increasing the load on your cooling system, making it work harder. A radiant barrier installed properly between your roof and the top of your attic insulation can significantly reduce the heat that reaches your ceiling. A radiant barrier is an aluminum foil material that prevents 95 percent of the heat that radiates from your roof from reaching the insulation on your attic floor, causing less heat to conduct into your living space. How Heat Moves From One Place to Another Heat always moves from areas of high temperature to areas of low temperature. It moves in three ways convection, conduction, and radiation.
Convection is the movement of heated air.
Convection is how heat flows out of your attic through ventilators and how it comes into your house through open doors and windows. Conduction is the movement of heat through a solid material, as when hot summer temperatures heat up an exterior wall, and that heat is conducted through the wall into your living space. The underside of your roof heats up by conduction, as heat from the surface of the shingles conducts through the material to the underside of the roof. The third way heat is transferred is by thermal radiation . When you are standing in front of a fire, the heat you feel is transmitted by thermal radiation.