These are glass insulating units made up of at least one low emissivity glass, which makes energy loss through the double glazing much less than in normal UVA. 

By using this type of glass, energy loss through the double glazing is reduced, and the sensation of comfort is much greater. This type of glass is recommended to be used mainly in areas in the north of Spain, in mountainous regions, in areas where there is cold weather. This type of glass cannot be considered as solar control glass.  Values of 0,7 W/m2K can be reached with triple glazing made up of two low emissivity panes of glass filled with argon.

In order to improve these values even more, “ warm-edge” profiles are being worked on that will allows us to lower the thermal insulation coefficient to 0,2.

This type of glass can be combined with laminated glass, acoustic laminates, to improve safety and comfort performance. 

Fundamentally for the residential sector and north facing façades for office buildings. They are being used for heated swimming-pools, to prevent heat loss and to generate a greenhouse effect that reduces the cost of keeping the water hot.