Smoke-free escape routes in case of fire, thanks to natural smoke and heat extraction and smoke removal. Welcome side effect: the function of a window ventilation system for daily ventilation. SHEV opening and locking systems consist of an electric spindle drive and a mechanical fitting set. Large opening widths with a small spindle stroke are achieved in seconds. The systems can be used on all common side-, bottom- and top-hung windows. The SHEV drive does not protrude into the room.