← Insulating glass units

Low-e coating

Also called low-emissivity coating

An invisible metal coating on a pane that reflects heat.

A low-emissivity coating is a microscopically thin layer of metal or metal oxide, applied to one of the surfaces facing the gap. It lets visible light through but reflects heat, keeping warmth in during winter or out during summer, depending on which surface carries it.

It is put inside the gap because it is soft and would wear off outside.

Edge of a double-glazed unit in section

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Insulating glass unit, edge in section

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