At Spray Foam of Atlanta we know that when done correctly, radiant barrier can be a good energy conservation value. Radiant barrier is a reflective surface that works by reflecting thermal radiation and thus inhibiting heat transfer. A simple way to picture radiant barrier is to think of it as foil you place over a casserole when you place it in the oven. The foil, reflects heat on top of the casserole and prevents the top of from burning.
Radiant barrier does however fall short in a few crucial areas. First, it offers no kind of water or air sealing for your home. That means air leaks, water penetration, mold, and mildew risks. It is also highly debated how effective radiant barrier is at keeping heat in and cold air out during the winter. Many of our customers who we’ve retrofitted after they were disappointed with radiant barrier told us there was virtually no appreciable difference in energy savings during the colder months.
Also, because radiant barrier is a thick coating or foil, it provides no sound absorption benefit. If your home or commercial building is in a noisy area, other options will provide you much better protection against noise.
Finally, and most importantly, while it does keep some heat out during the summer, radiant barrier is simply outperformed by spray foams insulation. Radiant barrier will reduce an attics temperature by 15deg-20deg in the summer, still leaving your attic between 115-120. That still puts a ton of strain on your A/C system. But with an expert spray foam installation, your average temperature will stay down to approximately 77-85 degrees even on summer’s hottest days