Does Radiant Barrier Insulation Really Work?

Function

• Radiant barrier insulation deflects heat from home surfaces that usually absorb hot air, such as attic insulation. It is placed between a radiating surface, like a roof, and an absorbing surface to reduce the amount of heat that is transferred to your home. Radiant barriers are usually made from heavy foil or foil sheet stock. Metal roof shingles, reflective roof sheathing and reflective chips are also available, although sheet radiant barriers are the most commonly used variety.

Effectiveness

• Radiant barriers are not meant to replace traditional insulation. Instead, they should be used in addition to insulation, and are often ineffective in homes that have 10 or more inches of insulation already in place, according to Kansas State University Extension. Radiant barriers are most effective in warm climates, and although they are primarily used to cool a house in hot summer heat, they also make a significant difference in the spring and fall months, since solar energy can still accumulate in the home during the warmer months of these seasons.

Cost

• In the right climate, radiant barriers can significantly reduce energy costs. According to the Florida Solar Energy Center, a radiant barrier can reduce energy costs by about 8 to 12 percent in warm Southeast climates. These costs vary widely based on your home's other energy conservation factors. For example, if you have a number of south-facing windows in your home or a minimal amount of natural shade, radiant barrier insulation may not make that much of a difference in cost, reports Byron Jones of the Kansas State University Institute of Environmental Research.

Tips

• Some types of radiant barrier insulation are more effective than others. If you do decide to purchase a radiant barrier for your home, choose products that have an emissivity of .1 or less and reflectivity of about .9 or more. Shinier products tend to work best. As noted by Energy Savers, proper installation is a critical factor in the performance of your radiant barrier, so have products professionally installed for maximum benefit. Avoid installing radiant barrier over attic floor insulation, since it is ineffective and may encourage dust accumulation.