3. Which glazing for enhanced thermal insulation?

3.1 Bare glass

For a sheet of conventional 4 mm thick soda-lime-silica glass, also known as float glass because it is produced on a production line using float technology which consists of casting the glass on a bath of liquid tin, the heat transfer coefficient K is equal to 5.7 W · m ^–2 · K ^–1 . Heat loss is mainly due to convection from the outer wall of the glazing. In this case, for an outside temperature of – 10°C and an inside temperature of +20°C, the temperature of the inner wall of the glass is equal to – 2.3°C.