Thermal insulating glass reduces heat loss compared to standard insulating glass. By replacing the inner pane with a low emissivity glass on a standard glass (a special layer of metal is applied to the glass surface), the heat transfer value can be significantly reduced. Further reduction of this value can be achieved by exchanging the air in the insulating glass cavity with a gas with low thermal conductivity.
These insulating glasses are characterized by yet another interesting effect. The high transmittance in the visible region of the solar spectrum allows a relatively high transmission of solar energy into the room, where the light is transformed into thermal, which is reflected back into the room by the metal oxide layer deposited on the inner glass. This increases the heat gains in the colder period.
In order to achieve more functional and aesthetic properties of this special insulating glass, the outer clear glass can be replaced by solar or safety glass.