How to Install Radiant Barriers for Energy Savings

One way to increase your energy savings and save money is by installing radiant barriers or reflective insulation in your home. Radiant barriers are thin reflective sheets designed to reduce radiant heat transfer within the home. The thin aluminum or other reflective material is usually bonded to another material, such as fiberboard or plastic, for increased strength and ease of handling.

The Energy Savings of Radiant Barriers

In warm weather radiant barriers reflect much of the sun's heat away from your home. This saves money on cooling costs by reducing the energy used by your air conditioning system. Reflective barriers can also reduce your heating cost by preventing heat loss during cold months.

How to Install Radiant Barriers

Although radiant barrier installation is relatively straightforward, care must still be taken to ensure the best results. In order for a radiant barrier to work properly the reflective side must face the open air space. If the reflective side touches another surface it actually conducts the heat instead of redirecting it away. For this reason you should never install a radiant barrier so the reflective surface is in contact with another surface.

The only exception would be when using a reflective insulation product where the radiant barrier is bonded to more conventional insulation. These products can be used in confined spaces with no airflow where the thin reflective type of radiant barrier is not appropriate.

When radiant barriers are installed in an attic, the attic must be properly ventilated to ensure the best performance. This may require modifications to the attic vents or installation of additional vents. Make sure the soffit vents and ridge vents have not been covered with any material. Insufficient attic ventilation can cause water vapor build up that can lead to damage if the vapor condenses and then freezes.

The simplest method of radiant barrier installation is to lay the material on the attic floor on top of the existing insulation with the reflective side facing up. This will reflect the heat up and out of the attic space. Do not compress the insulation, as this will reduce its effectiveness. This technique is not appropriate if the attic is used for storage, as sufficient clear floor space may not be available. Another major drawback of this technique is that over time dust accumulation on the reflective material will reduce the effectiveness of the radiant barrier.

Another technique is to staple the radiant barrier to the faces or bottoms of the rafters. This keeps floor space clear and reduces the problems of dust build-up while allowing adequate air space between the radiant barrier and the underside of the roof deck.

More advanced techniques can be used during new home construction or extensive retrofits of existing homes. These include installing radiant barriers in the walls or attached to the rafters before installation of the roof decking.

When properly installed, radiant barriers can reduce summer cooling costs by 5 to 15 percent. Savings in the winter heating cost, while not as large, can also be significant.