Double glazing is two pieces of glass held apart by a spacer bar.  The width of the space formed by the spacer bar impacts the insulation performance of your windows.

Cold will travel through the space, from one side to the other, more easily if the space is too small.  This movement happens by conduction where energy passes through molecules.  Should the space be too large, then circulating currents (or convection) form inside the double glazing resulting in reduced thermal performance.

When choosing SuperTherm™ argon filled double glazing, a 12mm space will provide 36% better thermal performance than a 6mm space.

The space should be at least 10mm and not more than 18mm. The optimal space depends on the type of glass (e.g., standard glass or SuperTherm™) and the type of gas sealed inside (air or argon).

By choosing retroGLAZE^® SuperTherm™ genuine double glazing solutions you can be sure you’re get the best energy-saving performance when retrofitting your existing windows and doors