- Green Technology
A Brief History of Radiant Barriers
A Brief History of Radiant Barriers
The use of radiant barriers as a method of permanently reducing utility costs and increasing the comfort of homes and buildings dates to the 1920's. Its use soon faced much opposition – traditional forms of insulation being preferred. However, the effectiveness of radiant barriers and reflective insulation continued to gain the interests of architects and engineers who were focused on energy-efficiency, and they began to specify them in their building and design plans. Ultimately, their determination and that of the reflective insulation industry - coupled with scientific support of the benefits of radiant barrier that was becoming widely available, convinced governmental agencies, builders, and consumers to accept it as a way to build higher energy-efficient homes.
In 1945, Alexander Schwartz, president of New York City’s Infra Insulation, Inc., produced a radiant barrier reflective insulation product called INFRA Insulation, designed specifically to reduce summer heat gain and winter heat loss in homes and in commercial buildings. In the 1950's, INFRA Insulation introduced an accordion-fold style product to the consumer market that was advertised as something that was easy to install by anyone who could use a staple gun. Newspaper advertisements even showed women installing the radiant barrier in their own homes.
In the mid 1950s, NASA was trying to find a way to protect astronauts during space walks from extreme temperature shifts ranging from -273 degrees Celsius to +238 degrees Celsius. Instead of trying to insulate the suits with a seven-foot thick protective layer using conventional insulation, which was obviously impractical, they turned to Clark E. Beck, PE, of Wright-Patterson Air Force Base to engineer the development of reflective technology for the space program. Weighing only slightly more than 17 pounds per thousand square feet, the material’s reflective surface kept more than 95 % of the deadly direct radiation from the sun (radiant heat) from reaching the interior of the space suit to keep them cool. Small holes allowed moisture to escape, while keeping longer heat waves from getting through Aluminum foil radiant barrier also reflected the heat of their own bodies back at the astronauts to keep them warm. The material maintained constant, comfortable temperatures inside the space suit.
Beck could not have foreseen the variety of applications for which this insulation material would someday be used. By the early 1960’s, millions of square feet of radiant barrier had been installed in homes and buildings. Unfortunately, an unfavorable FTC ruling against Infra Insulation Inc., and Schwartz’s sudden death resulted in the removal of the product from the market entirely by 1965, and the business closed. Soon after the collapse of Infra Insulation, Inc., several companies began to develop their own reflective insulation products in a variety of forms including those that contained bubble layers; single-sided aluminum Kraft paper-backed barriers, aluminum-faced fiberglass, and aluminum faced cardboard products.
After Schwartz’s death and the demise of Infra Insulation Inc, corporate interests in a range of traditional insulation products like fiberglass, cellulose, Styrofoam, and rock wool challenged the growth of the radiant barrier industry. The increasing popularity of radiant barriers posed a high competitive threat to their products. Through lobbying and industry association campaigns, they tried to obstruct the development or acceptance of radiant barriers in the marketplace.
The traditional mass insulation industry spent millions of dollars in marketing campaigns and consumer education to convince the public that an R-Value rated insulation product was what they needed. These products absorb or slow down convective (the transfer of heat in fluids, such as rising heated air, steam, and moisture) and conductive (the transfer of heat flowing through a substance ‘molecular motion’ or to another touching substance), heat transfers to insulate, but they do not block heat. In time, 100% of the heat absorbed eventually transfers through the insulation. The rate in which this heat eventually transfers through an insulation material is the material's R-Value. Since radiant barriers do not meet these criteria because they work differently than traditional insulation, consumers were discouraged from purchasing and using reflective radiant barrier insulation products.
However, consumer confidence in radiant barriers grew as word started to spread in the insulation industry of the benefits of radiant barrier products. Several well-known testing facilities and research organizations, as well as The Department of Energy, Oak Ridge National Laboratory, The Florida Solar Energy Center, and Texas A&M University, conducted their own studies to calculate and prove the substantial benefits that radiant barriers provide, and radiant barrier technology gained the confidence and support of architects and engineers.
Since the Gemini and Apollo missions,NASA has been using radiant barrier insulation as the key element of the environment control system that has enabled astronauts to work inside the Command Module without having to wear bulky space suits. During the decades following these missions, the space program on practically all spacecraft, including unmanned missions for instruments requiring thermal protection, has used radiant barrier.
For the past three decades, NASA's radiant barrier technology has been public domain. Besides its use in space blankets and numerous other applications, reflective insulation is now commonly used for energy-saving home insulation, awnings and canopies, agricultural insulation, automotive insulation, and the protective wear that is used by firefighters.