Radiant Barrier Tech Brief
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NASA TECH BRIEFS Mission Accomplished In the mid-1950s, when Clark E. Beck, PE, of Wright -Patterson Air Force
Base discovered and pioneered the development of radiant barrier technology for
NASA and the space program, he couldn't have envisioned the variety of
applications for which the insulation material would someday be used. But
today, radiant barrier technology has been spun-off into products as diverse as
energy-saving home insulation, candy wrappings, footwear inserts, and
protective clothing. The radiation barrier has been in use by NASA since the Gemini and Apollo
missions. The insulation was the prime element of the environmental control
system that allowed Apollo astronauts to work inside the Command Module in
short sleeves, rather than in bulky space suits. The material maintained
constant, comfortable temperatures inside the spacecraft, while temperatures
outside fluctuated from -273 degrees Celsius to +238 degrees Celsius. Made of
aluminized polymer film, the material provided a reflective surface that kept
more than 95 percent of the radiant energy from reaching the interior of the
spacecraft. In addition, the radiant barrier was used to reduce the required thickness
of the astronauts' space suits. If it had not been for this technology, the
U.S. space suits would have been seven foot thick. Since the Gemini and Apollo
missions, the radiant barrier has been used on virtually all spacecraft,
including unmanned missions where instruments require thermal protection. It is
used in the current fleet of space shuttles to protect the onboard computers. The material, called Energy "Q", is made of 99 percent pure
aluminum with a fire-resistant polypropylene insert. Small holes allow moisture
to escape, while keeping longer heat waves from getting through. Weighing only
slightly more than 17 pounds per thousand square feet, the material reflects 97
percent of the heat that strikes it. All objects radiate heat - from wood to glass, and even ice. Energy
"Q" works by reflecting 95 percent of radiant energy, which is the
flow of invisible infrared rays from an object's surface. When installed in an
attic, for example, it helps keep a building warmer in the winter and cooler in
the summer, and is more environmentally friendly than traditional insulation
such as fiberglass. In new construction, the radiant barrier is placed between the wall studs
and the exterior facing prior to the addition of aluminum, vinyl, or wood
siding. In new roof installation, it is placed between the roof supports and
the roof sheathing. When remodeling, the radiant barrier is placed on top of
insulation blankets on the attic floor to reflect energy. In California, new
homeowners using Energy "Q" insulation in their attics are given
energy credits. Terrestrial Uses for Space Technology Inside a structure, the material can be used to wrap hot water pipes or
tanks, insulate and provide a vapor barrier for steam baths or saunas: insulate
steam pipes, refrigerant lines, heating, ventilating, or air conditioning
ducts; line refrigerated holds on fishing vessels or in food-transport
trailers; and insulate boats and aircraft. On farms, the material protects livestock in stalls and stables, and
insulates poultry and rabbit facilities. It also may have application as liners
beneath the pavement to bridges in areas where cold weather causes them to
freeze over, and beneath golf courses and parks to wrap sprinkler pipes. Energy "Q" was used to cover a commercial gas-fired boiler room in
a school, reducing the room temperature by 15 degrees. As a result, the room
above the boiler room was able to be used as a classroom. The material also
increases the performance of a shrink-wrap oven used to shrink plastic
protective coverings over auto seats before shipping. The barrier successfully
reflected the energy inward estimating that in these applications, the supplier
realized a pay back of 30 days of energy savings. Energy "Q" has found uses for insulation in automobiles and trucks
to protect passengers from engine, solar, and exhaust heat. NASCAR drivers use
it to help protect them from the extremely high temperatures encountered in the
vehicles' cockpits. The potential applications of this material are just beginning to be
realized. Clothing can be made with the material as an insulator; fire
fighters' protective suits incorporate Energy "Q", as do subzero
liners for sleeping bags and emergency care thermal blankets. In the food
transportation and storage field, Energy "Q" is used in refrigerated
vans, railroad cars, picnic coolers, and pizza delivery bags. Seafood companies
are using it to insulate bags and to line bulk containers. The Energy "Q" products also are featured as part of a 32 city
tour conducted by NASA that began last summer and runs through this year. |
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