Façades need a shading device that allows for solar gains in winter but blocks direct sun radiation in summer.

GLASSX solves this requirement by deploying a transparent prism in the space between the outer glass panes. Light of the low winter sun passes the prism almost unimpeded. Above a certain angle of incidence –in the temperate zone between April and September- the geometry of the prism causes total reflection of the direct sun light. Then, only the diffuse, low-energy part of the radiation lights the interior.


High sun, angle of incidence > 40°

Total reflection of the sunlight



Low sun, angle of incidence < 35°

Unimpeded transmittance of the sunlight