To understand how our glass works. it is useful to understand emissivity. Emissivity is simply the ability of a material to absorb or lose (emit) heat: it is measured on a scale of 0 to I .

A high value means that the material is a good emitter of heat - that's bad news for you - as it loses heat quickly, so you're losing out in terms of comfort and cost efficiency.

Obviously, a low value means that the material is a poor emitter of heat - that's good news for you as it loses your valuable heat more slowly.

Ordinary clear float glasses have an emissivity of 0.9. This value is high so insulation value is low. Our glass has an emissivity 0.17, a very low figure, which indicates that our glass loses heat slowly, providing you with excellent insulation.

Variation of U value with airspace