Energy Savings from a Radiant Heat Barrier

A radiant heat barrier can generate energy cost savings for you, but the amount of savings will depend on where you live, your energy-use habits and how much you pay for the radiant heat barrier. The following information explains how radiant heat barriers work, the savings you can expect and factors that can affect it. 

What Is It and How It Works

A radiant heat barrier is a thin, reflective sheet, often aluminum, applied to the underside of your roof or over existing insulation. It removes up to 97 percent of radiant heat reducing the temperature in your attic and reducing the amount of heat transferred into your home. It is different from traditional insulation which traps air in its fibrous material reducing the flow of heated air from the attic to your home.

Your Expected Savings

The primary source of savings from a radiant heat barrier is from reduced cooling costs. A radiant heat barrier should reduce the amount of heat transferred from your attic to your home by 40 percent. Some estimates claim that yields a 20 percent reduction in warm weather electric bills, depending on your usage, but this is unlikely. A more reasonable estimate comes from the Florida Power Corporation, which says homes in the Southeastern United States can expect an 8 to 12 percent drop in cooling cost. That leads to a payback for the investment in a typical radiant heat barrier in five to six years.

Current Insulation Makes a Difference

The amount of energy savings from a radiant heat barrier can be affected by your current insulation. Insulation is measured by its “R” factor, which rates it for heat flow. If your attic is already insulated with R-30, a high rate, the radiant heat barrier will have reduced effect. If you have little or no insulation, the 40 percent reduction in attic heat flow from a radiant heat barrier is signficant.

Where You Live Makes a Difference

While a radiant heat barrier is sold as saving money in two ways—lower cooling costs in the summer and lower heating costs in the winter—the real savings is on cooling costs. Therefore the payback for an investment in a radiant heat barrier will be considerably longer in locations with milder climates. It will still save you money on energy costs, but less per year than in hot climates.

Emerging Data

As mentioned above, traditional insulation, which has decades of use to develop a measurable track record, is rated by its R factor. The higher the R factor, the better it reduces heat flow. As a relatively new technology, the radiant heat barrier does not yet have an equivalent to the R factor rating, making it more difficult to judge its effectiveness. There is no doubt it reduces heat flow significantly and can reduce your energy costs depending on your personal habits. But watch for radiant heat barrier ratings to be developed, allowing you to more closely estimate when you will save money and how much.