Saving a World of Energy
A HISTORICAL PERSPECTIVE OF RADIANT BARRIER AND REFLECTIVE INSULATION SYSTEMS
What do Frank Sinatra, the Atomic Energy
Commission, the Ohio State University and the National Bureau of Standards wind tunnel
have in common? These days, probably not too much, but in the 1940's and '50's all were
part of a rapidly growing group of building owners who sealed out summer-heat and
winter-cold with an ingenious combination of dead air spaces and reflective aluminum foils
found in an insulating technology known as "Radiant Barriers or Reflective
Insulation."
A radiant barrier system is, in general, a
layer of foil facing an airspace, installed in the envelope of a building. Such systems
are very effective in impeding radiant heat transfer and consequent heat gain/loss.
We depend on a number of strategies to keep
heat out of buildings. Mostly, these affect heat gains by conduction or convection. In the
average house, insulating walls and ceilings primarily restrict conduction. Double-glazed
windows restrict both conductive and convective heat gain.
We have largely ignored radiation - the
third means of heat transfer - except in using window treatments and coatings that
reflect, absorb or shade from solar energy. But research points to exciting potential for
reducing heat gain in buildings by controlling radiation transfer in walls and ceilings
through the use of radiant barriers.
Radiant Barriers work on a simple and
proven principle. Heat, like light, travels primarily by radiation, not convection
(air currents) or conduction (contact). And, just like light, the flow of heat, can be
reversed by simple reflection. One of the oldest applications of reflection combined with
dead air spaces for insulation is the familiar vacuum bottle.
The first documented application of a
radiant barrier was around 1872 when Sir James DeWar discovered that a reflective surface
on one side of a vacuum space could dramatically improve its ability to keep hot things
hot and cold things cold. Since that development, the insulative properties of reflective
spaces have been a matter of scientific certainty. Nevertheless, from the DeWar flask,
ancestor of the modern thermos bottle, to the space suits of NASA's astronauts, the saga
of reflective insulation has been one of vast possibilities as yet unfulfilled.
In 1945 Dr. Alexander Schwartz introduced
an ingenious combination of multiple layers of aluminum foil with a succession of dead air
spaces, thus ushering in what promised to be a bright new era of reflective building
insulation. Since its secret was the ability to reflect infrared heat rays, Dr. Schwartz
named his new material INFRA. Architects, engineers and builders readily embraced this
unusual but scientific approach to their familiar insulation problems and by the early
'60's millions of square feet of radiant barrier had been installed.
So now you're wondering, if radiant barrier
or reflective insulation was so good, what happened to it, right? The untimely death of
the founder, Dr. Alexander Schwartz, coupled with an unfavorable ruling by the FTC that
seriously impacted his distribution strategy, succeeded in effectively destroying the
company. Management found itself unable to reorganize and in 1965 his product went
completely off the market.
Since that time, many companies have
attempted to market similar radiant barrier products, and have, in fact, developed many
additional applications for various configurations of radiant barrier. Radiant barriers
are now laminated to foam, fiberglass, cardboard and other traditional building, products.
Insulation wraps have been developed that utilize the "bubble pack" packaging
material, consisting of a light nylon air barrier, laminated with radiant barrier on both
sides. This product, because of the reflective air space created with the bubbles,
provides an R value in addition to radiant heat reflection when wrapping duct work, water
heaters, pipes, etc.
The development of the radiant barrier
industry, though, was not to go unchallenged. Entrenched corporate interests, heavily
committed to the manufacture and marketing of various forms of mass insulation, recognized
the potential competitive threat of an insulating system like radiant barrier and
reflective insulation, and were determined to nip any further development in the bud.
By the late 1970's progressive architects
and builders, investigating radiant barrier and reflective insulation technology, became
convinced of its effectiveness and began specifying and using it with satisfying results.
Because millions of dollars in advertising
had been utilized for years in educating the public with "R" value technology,
and as radiant barriers had no "R" value, they were not readily receptive to
this technology. Most contractors, builders, lumber yard owners, etc. had no idea that
radiant heat was such a major source of heat transfer, nor had they been educated in how
to address that problem.
Obviously, a major educational effort would
be needed before the public would be willing to invest in radiant barriers and reflective
insulation. And until the public acquires the education necessary to make an intelligent
choice, and therefore readily asks for radiant barrier or reflective insulation products,
most retailers will be unable to sell enough product to justify stocking it nor be able to
adequately promote it.
Attic and wall radiant barriers and
reflective insulations made of aluminum foil are becoming a popular way for homeowners to
save energy and money, while substantially increasing the comfort levels of their homes
and offices. This increasing popularity, in addition to the increased exposure of the last
several years, is due to two other reasons. First, tests by the Florida Solar Energy
Center, Oak Ridge National Laboratory, Tennessee Valley Authority, Texas A&M
University, and other institutions have proven how well radiant barriers and reflective
insulations work. Second, manufacturers are improving the quality of radiant barrier and
reflective insulation materials especially the barrier bubble products.
The installation of a radiant barrier and
reflective insulation system is a permanent way to reduce costs. You need make only one
purchase, and pay for it one time. Once the purchasing cost of the radiant barrier system
is recouped, you never again have to pay out for it, but you continue to save every year.
In fact you'll save more money every year because you'll use about the same amount of
energy, but the cost of the energy that you save will have spiraled upward yearly.
A radiant barrier system is a good
investment in geographic areas that require a lot of heating and/or air conditioning (even
if the heating requirements are low). The National Bureau of Standards and the
Federal Energy Administration sum it up by saying, "Even though utility bills rise as
energy prices increase, the rise will be much less than it would have been. In fact, you
might think of energy conservation improvements as a hedge against inflation." |
