Material must be installed
with a minimum of ¾" of air space on both sides in order
to achieve maximum thermal performance. Since Astro-Foil
is a "system" insulation, R-values will vary according to
the specific application. The R-value stated above represents
an installation in an enclosed cavity formed by standard
2" x 4" wood framing members, encapsulated by plywood.
There are no specific requirements
for maintenance. Before installation, Astro-Foil should
be stored in a clean, dry environment. It should never be
stored on bare concrete.
Cost and Availability
Quantity and freight affect
cost. Standard structures and roll sizes are available for
immediate shipment throughout the US and Canada. Allow 4
weeks for special order delivery.
Warranty covers workmanship
and quality for the life of the building application. Assistance
in application techniques and installation guides are available.
R-Values UP, Down,
Because we are in the insulation
business we are always asked, "What's the R-value of ASTRO-FOIL
?" That's because everyone has been thought that R-values
alone determine the thermal performance of the insulation-right?
R-values by definition
measure the insulation's ability to resist heat loss by
CONDUCTION. Heat moves within a room or building primarily
by RADIATION of heat energy waves. Like the warmth one feels
from heat waves produced by a wood stove. All the objects
in an enclosed structure give off (emit) radiant heat waves,
exchanging them with the other objects and wall/ceiling
surfaces. The walls and ceilings will absorb the radiant
heat waves, converting them to conductive heat that can
then pass through the wall system to the cooler outside
environment. The job of mass insulation is to slow down
that heat transfer by resisting its flow. It is the rate
of this heat transfer through the mass insulation that is
a measure of the R-value of the material.
BUT, THERE IS A BETTER WAY!
What if that heat could be reflected before it had a chance
to be absorbed? It is in the nature of the pure, (99.9%)
aluminum surfaces of ASTRO-FOIL to reflect 97% of the radiant
heat waves that strikes its surface. By reflecting the radiant
heat waves, the foil surface remains relatively cool, leaving
very little heat to be absorbed and conducted through the
surface to the cooler outside of the building. Therefore
the R-value of the materials behind the ASTRO-FOIL
becomes relatively unimportant.
SO WHY DO WE PUBLISH R-VALUES?
Because R-values remain the only industry standard for measuring
thermal performance of insulation products, and the Federal
Trade Commission requires that we publish the tested results
for residential applications. All reflective insulations
require air spaces in order to work. Our test model for
ASTRO-FOIL is an enclosed
cavity formed by standard 2" x 4" framing lumber.
WHICH BRINGS US TO THE UP,
DOWN, HORIZONTAL QUESTION! As air within the test cavity
is heated, convection takes place, and depending on the
direction of the heat flow being tested will have an affect
on the R-value. HORIZONTAL heat flow through a wall will
result in nominal convection loss. UPWARD heat flow, as
through the ceiling in the winter is in the same primary
direction as convection, so the R-value is significantly
reduced. In DOWNWARD heat flow applications, such as through
the floor to a crawl space in the winter, or through the
roof in the summer convection is not a factor, resulting
in maximum R-values.
What is R-value of ASTRO-FOIL?
must be installed with an air space in order for it to reflect
heat, we state its R-value in terms of its installed "system",
which includes the R-value of those surrounding air spaces.
All reflective insulations have different R-values depending
on the direction of the heat flow because the effects of
convection in the air spaces vary with the direction of
the heat flow. Therefore, ASTRO-FOIL's
R-value is expressed as follows: But always remember; because
ASTRO-FOIL reflects heat first,
its thermal performance is not fully measured by its R-values.
In many applications, ASTRO-FOIL
can substantially out-perform mass type insulation products
of comparable R-value.