Glass performance


A standard double glass insulated unit consists of: 

  • an outer pane (4mm, 6mm, 8mm etc)
  • cavity (usually 12-20mm and is filled with argon gas)
  • an inner pane (4mm, 6mm, 8mm etc)

The main factors for a double or triple glass are listed below:  

  • U Value
  • Visible Light Transmission (VLT)
  • Shading Co-Efficient
  • UV Elimination %
  • Accoustic 

U Value

This measures the difference between the indoor and outdoor temperatures, or how much heat passes through your glass. A lower U-value means lower heat transfer and better insulation of your home.


Ways to Reduce U-Values & Improve Insulating Performance

  • Low-e coating: Improve better U-value and 
  • Use double-or triple-glazing
  • Optimize gas cavity: Thicker cavity between glass panes provides better U-value.  
  • Gass filled cavity: Gas filling the cavity inside sealed units gives added thermal insulation to the glass. Argon is the most common gas used for double and triple glasses. Argon is twice as dense as air and thus slows the heat transfer across the cavity of the sealed unit, giving extra thermal insulation. Krypton is another type gas used for certain types of specialist glazing. Krypton is denser than Argon and thus slows the heat transfer further but this is cavity dependent. Krypton works best in narrow cavities.
  • Specify warm-edge spacers

Low-e coating is usually applied to the interior surfaces of the glass within air cavity.