Just like a space suit, Radiant Barrier reflects the sun’s heat before it can warm up the insulation in your attic. When the insulation stays cooler, your house will stay cooler. It helps to understand how Radiant Barrier will work for you if you think of other things that work in much the same way. Astronauts’ space suits keep body heat and reflect the sun’s heat away. Thermos bottles keep hot things hot and cold things cold. They are almost perfect insulators. The tight seal and air space prohibit heat transfer by conduction and convection. The reflective surfaces inhibit radiation heat transfer. If the bottle starts out hot, it stays hot because very little heat is transferred to the cooler outside. If it starts out cold, it stays cold because very little heat is transferred from the warmer outside.
Just like wrapping a baked potato in aluminum foil keeps a potato warm longer by holding the heat in, covering your attic insulation with Radiant Barrier holds heat in the house. Another analogy would be that Radiant Barrier in the winter works just like a space blanket, which, although very thin and lightweight, holds your body heat in. A thin space blanket can keep you warmer than several heavy blankets.
A1 “Hundreds of samples of aluminum foil have been stored in the laboratory for various periods of time up to 10 years with no visible signs of deterioration.” American Society of Heating & Air Conditioning Engineers’ Journal Section. A2 “Aluminum is highly resistant to the effect of corrosion… Aluminum is constantly being used where it is exposed to weather, salt spray and other conditions, which would adversely affect most metals.” The United States Rubber Co. Booklet, Serving You Through Science, Page 5.
This very issue has been studied by research institutes. Most attics don’t accumulate enough dust to affect Radiant Barrier’s ability to save energy costs. Thousands of homes and structures have had Radiant Barrier installed for as long as ten years or more with no significant accumulation.