Low-E
Glass
“Low-E Glass” refers
to a series of high-performance
low-emissivity products manufactured
by TGI introducing state-of-the-art
vacuum sputtering coating equipment
and technology from USA's Applied
Films Group and Germany's Von
Ardenne. The vacuum sputtering
process coats glass surfaces
with several layers of different
materials. Among these, a silver
layer effectively reflects infrared
rays while maintaining excellent
thermal performance. Beneath
the silver layer is an anti-reflective
tin oxide (SnO2)
base layer that increases the
transparency of the glass. Above
the silver layer is an isolating
nickel-chromium (NiCr) alloy
coating. The main function of
the top anti-reflective tin
oxide (SnO2) layer
is to protect the other coating
layers. This product offers
the high transparency, low reflectivity,
good thermal insulating and
energy-saving properties required
of modern architectural glass.
Highly
transparent to visible
light (wavelength
380nm ~780nm), will
not cause significant
glare problems due
to high reflectance
of visible light.
•
Allows
most sunlight in the
visible range to enter
without altering its
natural color. Provides
excellent natural
illumination and saves
energy by reducing
the need for artificial
lighting.
•
Relatively
high reflectance of
infrared radiation
(wavelength 780nm
~ 3,000nm). In particular,
reflects nearly all
long-wave infrared
(wavelength over 3,000nm).
Blocks the entrance
of large amounts of
heat, and leaves interior
comfortably cool in
the summer and warm
in the winter.
The
right assembly suitable
for energy-saving
glass curtain walls
and skylights in modern
Green Building located
in hot subtropical
areas, such as Taiwan.
Low-E
glass cannot be used
as a single glazing
and must be sealed
or processed into
insulating glass unit
within a very short
time as the metallic
oxide coating is prone
to undesirable reactions
once exposed to air.
•
Emissivity
of Low-E insulating
glass is 0.02 ~ 0.11,
while that of uncoated
glass is 0.84.
•
In
tropical or subtropical
areas, the Low-E coating
should be positioned
on #2 surface (facing
inward from outside
the building), while
positioned on #3 surface
in temperate areas.
•
The
finished Low-E glass
products cannot be
further bent-processed.
•
Traditional
Low-E glass must be
tempered before coating.
TGI is developing
processable Low-E
glass which can be
tempered after coating.
•
To
avoid deterioration
and fogging of the
glass due to water
accumulation, the
metal holding frames
must be well drained.
•
Low-E
glass designed for
laminated glass unit
will be under a greater
U-value and poorer
thermal insulating
capability.
•
To
identify the coating
surface of Low-E glass,
aside from looking
for the TGI mark,
use a cigarette lighter
to inspect the surface
of the glass. Reflection
of the flame on ordinary
glass surface will
be yellow, while pink
or blue on Low-E glass
surface.
Summer:
Blocks the transmission
of most solar heat
radiation;
keeps room pleasantly
cool by allowing only
a small amount
of heat in (Low-E
coating on second
surface).
Winter:
Low-E insulating glass
keeps interior warm
by blocking
outward radiation
of heat.
