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First, "traditional" insulation is meant to be
mass insulation for
protection against heat transfer by conduction.
ASTEC protects
against heat transfer by radiation. Both mass insulation (i.e.
fiberglass wool, polyurethane foam, etc.) and radiation control
coatings (i.e., ASTEC) have value and one does not necessarily
replace the other. In many cases, radiation control coatings
complement mass insulation to give it added value benefits.
"Traditional" insulation (i.e. fiberglass wool) is usually installed
on the underside of a roof or inside the walls of a building and
absorbs heat from the roof's exterior surface. Since heat always
travels from a "hot" environment to a (relatively) "colder"
environment, the absorbed heat energy transfers into the building
where temperatures during sunlight hours are normally lower than the
ambient air temperature. Where mass insulation is applied to the
exterior surface of the roof (i.e. polyurethane foam), the same
principles of heat management apply.
Ordinary construction materials (i.e.: metal roof) absorb between 90
and 95% of the heat from solar radiation and they develop very high
roof temperatures. While the thickness of mass insulation is the key
to a lower rate of heat transfer (the thicker the mass insulation
material, the more resistance to heat transfer), this form of
heat
management may not be cost effective. At some point, the cost of
increasing the thickness of mass insulation exceeds the added
insulation benefits.
ASTEC prevents 85% of the heat from solar radiation from ever
getting into the roof because of its high solar reflectivity
(varying between 85% and 94% depending on the wavelength of the
electromagnetic radiation incident upon the roof). This primary
function of ASTEC refers to heat prevention. The old adage prevails:
it is better to prevent than to cure!
Heat management is also an important feature of ASTEC thermal
properties. The 15% of heat (from solar radiation) absorbed into the
protective layer of ASTEC is easily and quickly dissipated with
ASTEC's high thermal emissivity of 0.91 which removes the heat at a
fast rate (the perfect rate is 1.0). Thermal emissivity is the rate
at which a surface radiates heat compared to the perfect emitter ("a
blackbody") at the same temperature. The higher the rate of thermal
emissivity, the greater the radiated heat back to the outside.
Ordinary construction materials and mass insulation have thermal
emissivity ranging between 0.10 (galvanized iron roof) and 0.40.
By comparison with ordinary construction materials, ASTEC will have
a substantially "cooler" surface temperature as it absorbs 70% to
80% less heat, and it radiates absorbed heat faster than traditional
construction materials and mass insulation.
ASTEC provides reduced building cooling load requirements and as a
system, it also provides other value-added benefits which are not
found in ordinary construction materials or in mass insulation.
• corrosion control
• protection against UV degradation
• long lasting waterproofing
• virtual elimination of thermal shock
• monolithic and flexible system
• environmentally acceptable water-based products
• low cost installation
• minimized roof maintenance
• architecturally attractive
• cost effective exterior insulation and finish system
• noise abatement factor/acoustical benefits
When comparing ASTEC with mass insulation,
ASTEC's Total Solution
approach is superior, more comprehensive, and more cost effective.
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