Radiant Barriers in the Attic to Prevent Heat and Humidity

A radiant barrier addresses major issues up in your attic: heat gain and heat loss. In summer, solar radiation from the sun passes straight through your roof and heats the attic. On a hot day here in Delaware, attic temperatures can soar to 150 degrees. Accumulated heat energy conducts through your ceiling into living spaces, raising room temperatures and making your air conditioner work overtime to compensate. The result is a less comfortable home and higher cooling costs.

It’s estimated that 93 percent of heat gain in a typical residence comes from radiant heat. In winter, conversely, heat produced by your furnace naturally rises to the ceiling and radiates out of the house. Your furnace runs longer “on” cycles to make up for it and heating costs soar. Up to 75 percent of household heat loss in winter is radiant heat escaping through the attic.

The Heat Barrier

Standard fiberglass or cellulose attic insulation absorbs and inhibits the movement of heat. A radiant barrier, however, is a thin film of plastic with a highly-efficient aluminum reflective coating. It’s usually stapled to the underside of the roof rafters. As radiant heat penetrates the roof, the barrier reflects that heat energy back out through the roof into the outdoors. In winter, radiant barriers inhibit heat loss through the roof by reflecting escaping household heat energy back toward the attic floor.

Insulate and Radiate

A radiant barrier helps standard attic insulation work more effectively by keeping the attic space cooler in summer and warmer in winter. Humidity is another factor that degrades effectiveness of standard attic insulation. When an overheated attic cools at night, humidity soars and condensation moistens standard insulation, degrading its insulating value. The radiant efficiency of radiant barriers, however, is unaffected by humidity. In addition, by moderating attic temperatures, radiant barriers also reduce formation of condensation.

At Sobieski Services, Inc., our goal is to help our customers in Delaware, Pennsylvania, Maryland and New Jersey learn more about energy and home comfort issues — especially HVAC and plumbing issues — so that they can save money and live in healthier, more comfortable homes.

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