The Double Glazing Glossary

Emissivity : Emissivity is a surface characteristic of a material. It is the relative ability of a surface to absorb and emit energy in the form of radiation. Low-emissivity (Low-E) coatings reduce the normally relatively high surface emissivity of the glass. The coatings are mainly transparent over the visible wavelengths but reflect long wave infra-red radiation towards the interior of the building.

Enhanced thermal insulation : Conventional double glazing provides thermal insulation. Double glazing comprising a low-emissivity glass provides enhanced thermal insulation.