What glass is used for double glazing?

The glass applied to a double glazed window is known for its thermal insulation – Low E, or low-emissivity glass. Low E glass has a transparent metallic coating that works to reduce energy use, by reducing the rate of emission of absorbed heat of the glass surface.  

The coating works in two ways:  

  1. Reflecting heat back inside a building
  2. Reflecting absorbed heat back outside when used for solar control 

Heat travels relatively easily through ordinary glass – in winter from inside to outside, and in summer from outside towards cooler air inside. This process can be slowed with insulation, which is why we use Chevron insulated glass units (double glazing). 

They can be manufactured with multiple choice of glass using clear, toned, high performance, laminated or toughened glass and with spacer bars of varying widths.