Daylight (VT) Visible transmittance (VT) indicates the amount of visible light transferred through the glass. The higher the VT, the more free daylight that is transmitted. Solar Heat Gain (SHGC) The Solar Heat Gain Coefficient is the fraction of solar radiation that enters the window and becomes heat. A low SHGC is important for warm or hot climates.
Heat Flow (U-Value) U-Value measures a window's resistance to heat flow. The lower the U-Value, the better the insulation of the window. A low U-Value is imerative in coll climates. Infiltration (AL) Heat loss and gain can occure by infiltration through leaks in the window assembly. The lower the AL (Air Leakage), the less air that passes through the window when it is in the closed position.

Glass (single glazed)

 
  Daylight (VT) Solar Heat Gain (SHGC) Heat flow (U-Value) Infiltration (AL)
5 mm Clear Float 88 % 0,84 5,9 *
6,38 mm Clear Laminated 89 % 0,80 5,9 *
5 mm Green Tint 80 % 0,64 6,2 *

* up to 0,98 without any rubber sealings. The rating is from 0,0 to 1,0 and 0,3 is recommended.

Glass (double glazed)

 
  Daylight (VT) Solar Heat Gain (SHGC) Heat flow (U-Value) Infiltration (AL)
Clear Float 4 - 15 - 4 mm 78 % 0,76 3,2 **
Green Tint 5 - 15 - 4 mm 71 % 0,54 3,3 **
Neutralux 4 - 16 - 4 mm 80 % 0,62 1,1 **

** up to 010 with two rubber sealings. The rating is from 0,0 to 1,0 and 0,3 is recommended.

Neutralux is the standard glass from Massclusivity used in all windows!