SPECIFICATIONS, TERMS & DEFINITIONS

VISIBLE LIGHT TRANSMISSION

Visible Light Transmission is the percentage of solar visible light (daylight) that passes through a glazing system.

SOLAR ENERGY REJECTED

Solar Energy Rejected is the percentage of total solar energy (heat) that is rejected away from a glazing system.

This equals solar heat reflectance plus the amount of solar heat absorbed that is then re-radiated outwards.

VISIBLE LIGHT REFLECTANCE

This is the percentage of reflectivity (mirror effect) that occurs on the glazing system.

The higher the value, the more reflective the exterior, providing a more mirror-like appearance.

SHADING COEFFICIENT

Shading Coefficient is the ratio of solar heat gain passing through a glazing system to the solar heat gain that

occurs under the same conditions if the window were made of clear, un-shaded double strength window glass

(lower SC equals better solar shading performance).

SOLAR HEAT GAIN COEFFICIENT

Solar Heat Gain Coefficient is the percentage of total solar heat that enters a glazing system. This includes heat

directly transmitted as well as heat that is absorbed by the glass and then transmitted inwards (lower SHGC

means less heat transfer from the exterior to the interior).

INFRARED ENERGY REJECTION (IRER)

The measurement of heat experienced from solar infrared radiation (780 - 2,500 nm), which includes both

re-radiated and absorbed energy.

SELECTIVE IR REJECTION (SIRR)

Solar infrared radiation (780 - 2,500 nm) not directly transmitted through the glass.

GLARE REDUCTION

The ratio of the difference in visible transmission of the glass before and after installing film to the visible

transmission of the glass with no film. It is expressed as a percentage and is determined by the respective

visible transmission values of the glass with and without film.

FADING REDUCTION

Combined fading percentages are determined by applying rejection percentages on each cause of fading

to determine the overall reduction in fade that a specific product can return.