SOLAR TERMS

• Solar Energy Spectrum : Solar Energy is typically divided into three categories, namely – Ultra-violet (3%), Visible (44%) & Infrared (53%).
• Visible Light Transmittance (VLT) : is the ratio of visible solar energy that passes through a glazing system to the total visible energy falling on the system. Higher the VLT more is the light inside the room.
• Solar Energy Transmittance : is the measurement of the percentage of solar radiation that passes directly through a glazing system.
• Solar Energy Reflectance : is the measurement of the percentage of solar radiation reflected by the glazing system.
• Solar Energy Absorption : measurements express the percentage of solar radiation absorbed by the glazing system.
• Total Solar Energy : is the sum of energy transmitted, reflected and absorbed by the system. It represents 100% of the solar energy.
• Ultra-violet Transmittance : is the measurement of the percentage of solar radiation in the ultra-violet region that passes directly through the glazing system.
• Glare Reduction : is a measurement of the reduction in visible light transmission after applying the film to the system as compared to the visible light transmission earlier. (It is represented in%).
• Solar Heat Gain : is the sum of percentage of solar energy that is either transmitted or absorbed and then re-radiated into the room.
• Shading Co-efficient: is the ratio of solar heat gain through a given glazing system to that of a clear float glass of 1/8 inch (approx. 3mm) thickness under the same test conditions. Lower the shading co-efficient, better is the ability to reduce solar heat.
• Emissivity :  measures the surface ability to absorb or reflect Far Infrared Radiation. Lower the emissivity rating, better the insulating quality of the material.
• ‘U’ Factor : is the overall heat transfer co-efficient of the glazing system. It is the amount of conductive heat energy (BTUs) transferred through one square foot of the glazing system during one hour time period for each one degree Fahrenheit temperature difference between indoor and outdoor air. Lower the U-factor, better is the insulating quality of the material.
• Total Solar Energy Rejection (TSER) : is an important measurement of the ability of a glazing system to reject solar heat in form of the visible light and infrared radiation. Total SER equals solar reflectance plus the part of solar absorption re-radiated outward. Glazing System comprises of the window frame, glazing materials, film applied and the glass itself. Thickness of the polyester film is represented in MIL where 1 MIL represents a thickness of 25 microns.