The window is a part of the gravitational smoke ventilation system and is used to expel the excess of smoke and heat during the fire. Additionally, the system enables daily ventilation and allows light into the room. The window is equipped with two electric motors, which open the window sash after a electric signal from the control unit. The open window protects the roof opening against the lateral wind. The window is installed in such a way that all the window edges are below the roof ridge level. The smoke ventilation window has been manufactured and certified according to harmonised standard EN 12101-2:2005. This window is usually applied in stairways.