Definitions
 
  Visible Light Transmitted (VLT)

The percent of total visible light (380-780 nanometers) to be passed through a glazing system. Test method: ASTM 903-82 
 
  Visible Light Reflected

The percent of total visible light to be reflected by a glazing system. Test method - ASTM E 903-82. 
 
  Ultra Violet (UV) Block

The percent of Ultra Violet radiation (300-380 nanometers) to be passed through a glazing system. Test method - ASTM D1003. 
 
  Total Solar Energy Reflected

The percent of total solar energy (300-2500 nanometers) to be reflected by a glazing system. Test method - ASTM E 903-82. 
 
  Total Solar Energy Transmitted

The percent of total solar energy to be passed through a glazing system. Test method - ASTM E 903-82. 
 
  Total Solar Energy Absorbed

The percent of total energy (300-2500 nanometers) to be absorbed by a glazing system. Solar absorbency is that portion of total solar energy neither transmitted nor reflected. Test method - ASTM E 903-82. 
 
  Emissivity

The ability of surface to absorb heat and to reflect it. The lower the emissivity, the less room heat is absorbed - the more heat is reflected back into the room. 
 
  U-Factor

The overall coefficient of heat transfer equals the reciprocal of R value. This value is a function of temperature and wind speed and is expressed in BTU per square foot per hour per degree Fahrenheit (BTU/sq.ft.hr/oF). The lower of U-Factor, the better the insulation qualities of the glazing system. 
 
  Shading Coefficient

The ratio of solar heat gain through a given glazing system to the solar heat gain under the same conditions for clear, unshaded double strength window glass (DSA). The shading coefficient defines the sun control capability of the glazing system. 
 
  G Value

The total amount of solar energy that goes to the inside of the building by reflection and by absorption.   
 
  Solar Heat Gain Coefficient

The total amount of solar energy that goes to the inside of the building by reflection and by absorption.
 
  Total Solar Energy Rejected

The percent of incident solar energy rejected by a glazing system equals solar reflectance plus the part of solar absorption which is reradiated outward. 
 


PRODUCT DATA