Abstract: A building ventilation system (1) comprising a central unit (2) and at least one electrical operating unit (3) for adjusting a movable member of a ventilation device, the central control unit (2) is connected to the at least one electrical operating unit (3) by two power supply wires (4) and configured to provide an operating voltage for operation of the at least one electrical operating unit (3) via the two power supply wires (4), wherein the power supply lines (4) are connected to an end module (5) and the central control unit (2) further is configured to provide a test voltage being lower than the operating voltage, wherein the end module (5) is configured to temporarily vary its load impedance with a predetermined pattern, and the central control unit (2) is configured to detect the temporarily varying load impedance of the end module.

Abstract: A smoke ventilation system comprising a system controller connected to window actuators of different building areas, and control points associated with the window actuators of different building areas, the system controller comprises a power supply module powering the window actuators and the control points, wherein the control points are connected to the system controller by a common serial bus comprising power supply and communication lines for communicating serial control signals to activate the associated window actuators of a building area.

Abstract: A method and a system for controlling ventilation of an indoor area of a building, comprising the steps of: ventilating the indoor area by means of mechanical ventilation and natural ventilation according to a ventilation mode selected among a plurality of ventilation modes, a set of adjustable control parameters (31; 32; 33; 34; 35) and at least one measurement value from a sensor, wherein each ventilation mode is associated with the set of adjustable control parameters (31; 32; 33; 34; 35), each having an adjustable value selected among a group of mode dependent adjustable values, and/or a set of fixed control parameters (34) each having a mode dependent fixed value, and controlling the mechanical ventilation and the natural ventilation by comparing the measurement value from the sensor with a corresponding value of the control parameters of the ventilation mode such that a desired indoor climate defined by the ventilation mode is obtained.