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How Does Radiant Barrier Work?
Radiant heat, the major source of heat flow, is energy in the
form of infrared waves. It travels at the speed of light, even through a
vacuum, and is either transmitted through, absorbed into, or reflected by any
material it contacts.
A white surface such as snow, reflects it & a black surface absorbs it. RB is
unlike mass insulation which only slows down or resists heat transfer. Radiant
Barrier reflects up to 97% of the radiant energy striking its surface. It
reflects sun's rays in the hot summer months and retains interior heat during
the winter months.
There are three ways heat goes from warm spaces to cold
spaces:
CONDUCTION
is direct heat flow through a solid object such as a wall or a ceiling.
CONVECTION
is heat movement through air, occurring when air is warmed.
RADIATION
is the movement of heat rays across air spaces from one warm object to a cooler
object.
ALL OBJECTS & BODIES GIVE OFF
RADIANT HEAT
Even the insulation in your attic gives off radiant
heat to the cold attic space in the winter, and to the loving space in the
summer. Regular insulation won't stop radiant heat loss. Radiant heat must be
REFLECTED with a radiant barrier.
How Does RB keep me warmer in the winter?
Covering your attic insulation with Radiant Barrier holds the hear in the house,
just as a space blanket holds your body heat in. A thin, lightweight space
blanket can keep you warmer than several heavy blankets.
Can Radiant Barrier keep heat out in the summer?
Just link an astronaut's space suit keeps body heat in and
reflects the sun's heat away, RB reflects 97% of the sun's heat before it can
warm up the insulation in you attic. When the insulation stays cooler, your
house will stay cooler.
Thermos Bottles work in much the same way. They
keep hot things hot and cold things cold. They are almost perfect insulators.
The tight seal and air space prohibits heat transfer by conduction and
convection. The reflective surfaces inhibit radiation heat transfer. If the
bottle starts out hot, it stays hot because very little heat is transferred to
the colder outside. If it starts out cold, it stays cold because very little
heat is transferred from the warmer outside.
Why couldn't I just put kitchen foil in my
attic?
You could, but kitchen foil would not be nearly as effective as Radiant Barrier
becuase it is only 22% aluminum, with other alloys and minerals that will cause
it to break down over time.
The Radiant Barrier is 99.5% pure aluminum, so is
much more reflective than foil and does not break down over time. Also the
Radiant Barrier contains small perforations so it breathes and doesn't cause
condensation.
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