Quadruple glazing (quadruple-pane insulating glazing) is a type of insulated glazing comprising four glass panes, commonly equipped with low emissivity coating and insulating gases in the cavities between the glass panes. Quadruple glazing is a subset of multipane (multilayer) glazing systems. Multipane glazing with up to six panes is commercially available.[1]
Multipane glazing improves thermal comfort (by reducing downdraft convection currents adjacent to the windowpane), and it can reduce greenhouse gas emissions by minimising heating and cooling demand. Quadruple glazing may be required to achieve desired energy efficiency levels in Arctic regions,[2] or to allow for higher glazing ratios in curtain walling without increasing winter heat loss. Quadruple glazing allows building glazing elements to be designed without modulated external sun-shading, given that the low thermal transmittance of having four or more glazing layers enables solar gain to be adequately managed directly by the window glazing itself.[3] In Nordic countries, some existing buildings with triple glazing are being upgraded to glazing with four or more layers.[4]