Quadruple glazing

Quadruple glazing (quadruple-pane insulating glazing) is a type of insulated glazing comprising four glass panes, typically equipped with low emissivity coatings and insulating gases in the cavities between them. It is a subset of multipane (multilayer) glazing systems. Multipane glazing with up to six panes is commercially available.

Multipane glazing improves thermal comfort by reducing downdraft convection currents near the window surface. It can also reduce greenhouse gas emissions by minimizing heating and cooling demands. Quadruple glazing may be necessary to achieve desired levels of energy efficiency in Arctic regions, or to allow higher glazing ratios in curtain walling without increasing winter heat loss. Its low thermal transmittance can also eliminate the need for modulated external sun shading, as solar gain can be managed by the window glazing itself. In Nordic countries, some triple-glazed buildings are being upgraded to four or more layers.