A radiant barrier works by reflecting radiated heat rays back towards the source they originated from. During the summer, the main source of wasted energy in your home is cause by the heat gain when the roof and walls absorb radiant heat from the sun. This heat is then conducted toward the attic space and eventually radiated into the attic. Most of this radiated heat can be reflected back towards the outside when a radiant barrier is installed. Without a radiant barrier the heat will be collected by the attic space and interior of the home or office. Fiberglass insulation does very little to stop radiated heat. In addition, the air conditioner and ductwork also absorb attic heat, which is then blown into the house/office. A properly installed radiant barrier blocks 97% of this radiant heat which will save money on cooling the home, and reduce the summer heat in the attic by 30%. During the winter, the main source of wasted energy in your home is caused by heat that is lost by your home when it naturally rises from inside the home and escapes through the ceiling into the attic and then out through the roof. Heat is radiated in all directions through the ceiling, walls and floor. Obviously the more heating energy that is lost, the more heating energy it takes to replace it. A radiant barrier reduces this wasted energy by reflecting most of the rising heat back towards the interior of the building.