Smart glass, EGlass, or switchable glass, also called smart windows or switchable windows in its application to
windows or
skylights, refers to electrically switchable
glass or
glazing which changes light transmission properties when voltage is applied.
Certain types of smart glass can allow users to control the amount of
light and
heat passing through: with the press of a button, it changes from
transparent to
translucent, partially blocking light while maintaining a clear view of what lies behind the window. Another type of smart glass can provide
privacy at the turn of a switch.
The use of smart glass can save costs for
heating, air-conditioning and
lighting and avoid the cost of installing and maintaining motorized light screens or
blinds or
curtains. When opaque, liquid crystal or electrochromic smart glass blocks most
UV, thereby reducing fabric fading; for SPD-type smart glass, this is achieved when used in conjunction with low-e low
emissivity coatings.
Critical aspects of smart glass include installation costs, the use of electricity, durability, as well as functional features such as the speed of control, possibilities for dimming, and the degree of transparency of the glass.