A radiant heat barrier can reduce your energy costs, 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 the factors that can affect that.
How Does a Radiant Heat Barrier Work?
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 both the temperature in your attic and 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.
How Much Can You Save?
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. The Florida Power Corporation says homes in the Southeastern United States can expect an 8 to 12 percent drop in cooling cost. That means a typical radiant heat barrier in that region will pay for itself 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-value. If your attic is already insulated with R-30, a high rate, the radiant heat barrier will have little 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 cooler your climate, the longer your radiant heat barrier will take to pay for itself. It will still save you money on energy costs, but less per year than in hot climates.
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 they reduce heat flow significantly and can reduce your energy costs, but as radiant heat barrier ratings are developed, you will be able to more closely estimate how much money you will save over a given time period.