Window Film Glossary
Dyed Film
Window
film that uses either a submersion process or a dyed adhesive process
to deposit dye onto its surface to achieve the qualities and look of
tinted film.
Emissivity
The
measure of surface's ability to absorb or reflect far-infrared
radiation. The lower the emissivity rating, the better the insulating
qualities of the installed window film.
Hybrid Film
Window film that is made up of a combination of metallic film and dyed film to achieve the qualities and look of tinted film.
Infrared Light
A
form of electromagnetic radiation with wavelengths between 0.
7 micrometers (0.0007 millimeters) and 1 millimeter. These wavelengths
are longer than those of visible light, but shorter than those of
microwaves. (The prefix 'infra' means 'below; infrared refers to
radiation below the frequency of red light.) Infrared light is
primarily thermal radiation, and we can think of this as being heat.
Metallic Film
Window
film that uses either a sputtering process or deposition process to
deposit metals onto its surface to achieve the qualities and look of
tinted film.
Shading Coefficient
The
ratio of solar heat gain passing through window film to the solar heat
gain that occurs under the same conditions if the window were made of
clear, unshaded double strength window glass. The lower the number, the
better solar shading qualities of the installed window film.
Total Solar Absorptance
The
percent of incident solar radiation that is absorbed by the installed
window film. The lower the number, the less solar radiation absorbed.
Total Solar Energy Rejected
The
percent of total solar energy (heat) rejected by the installed window
film. The higher the number, the more total solar energy (heat)
rejected.
Total Solar Reflectance
The
percent of incident solar radiation that is reflected by the installed
window film. The lower the number, the less solar radiation reflected.
Total Solar Transmittance
The
percent of incident solar radiation that is transmitted through the
installed window film. The lower the number, the less solar radiation
transmitted.
U-Value
The
ability of heat to transfer through one square foot of window film for
each degree fahrenheit difference in temperature. The local climate or
environment in which the window is located, affects the level of heat
transfer and the rate. In summer, heat transfers from the outdoor air
to indoor air. In winter, heat transfers from indoor air to outdoor
air. The lower the U-Value, the better insulating qualities of the
installed window film.
Ultraviolet Light
Light
having a shorter wavelength and higher energy than visible light.
Ultraviolet light is potentially damaging to library, archive, and
museum objects. Removing UV light can reduce the rate of deterioration.
Ultraviolet Transmittance
The
percent of ultraviolet light (UV) that is transmitted by the installed
window film. The lower the number, the less ultraviolet transmitted.
Visible Light
Electromagnetic
radiation at wavelengths which the human eye can see. We perceive this
radiation as colors ranging from red (longer wavelengths; ~ 700
nanometers) to violet (shorter wavelengths; ~400 nanometers).
Visible Light Absorptance
The
percent of total visible light that is absorbed by the installed window
film. The lower the number the less visible light absorbed.
Visible Light Reflectance
The
percent of total visible light that is reflected by the installed
window film. The lower the number the less visible light reflected.
Visible Light Transmittance (VLT)
The
percent of total visible light that is transmitted through the
installed window film. The lower the number, the less visible light
transmitted. As an example, limousines usually tint their windows with
films that have a VLT of 5%.
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