Can Radiant Barriers Really Save You Money?
Unless you've been living in a cave, you've probably seen some media-buzz about radiant barriers lately. If you have in fact been living in a cave, then know that a radiant barrier is a layer of reflective material that keeps heat from invading your home, ideally lowering your cooling costs in warm weather.
The big question is: do radiant barriers actually work? Good question. Let's check the facts.
Radiant barriers can take a number of forms. For example, you can apply them to multi-layered windows as thin metallic films, and simply painting your roof white to reflect sunlight can cool your house by up to 15% per 1,000 square feet.
But in common usage, the term "radiant barrier" generally refers to a metallic foil installed on an attic ceiling -- that is, inside of rather than on top of the roof. To be effective, the material must have a high reflectance level, bouncing back at least 90% of the heat that strikes the surface.
The greater the temperature difference between the two surfaces, the higher the barrier's cooling ability. Plus, radiant barriers of all types require an adjacent airspace in order to work. One or both sides may be reflective; when only one is, the shiny side should face into the attic.
Well, Do They Work?
Indeed they do, if you live in a warm, sunny climate. But they're less effective in cooler climates, so consider carefully before jumping on the radiant barrier bandwagon.
That said, with predictions that summer temperatures will regularly hit triple digits across most of the country in the next decade, radiant barriers are definitely worth thinking about, especially if you live in the South or West.
Typically, a radiant barrier can help you decrease your energy costs by at least 5-10% in the summer, though you can save more if your air conditioning ductwork runs through your attic. I've seen savings claims as high as 25-30%. As with most things, your mileage may vary.
Dollars and Sense
Saving 10% or more on cooling costs is nothing to sneeze at; you can easily save a C-note a year that way. Even better, radiant barriers are absurdly cheap. You can get the material for as little as a dime per square foot, which comes to just $150 for a 1,500 square foot attic. Not bad.
Even if you spring for an expensive brand and have someone install it, it rarely costs more than $1,000 for the above attic size, and often much less. So installation doesn't break the bank, and the effort pays for itself in a few years. If you do live in a sunny climate, then radiant barriers are good investments!