Abstract: An air-distributor box for a heating/air-conditioning system of motor vehicles has a first air-outflow orifice for the connection of a lateral nozzle and a second air-outflow orifice, arranged below the first air-outflow orifice, for ventilating the foot space as well as an air flap controlling the air stream to the second air-outflow orifice. In order to avoid the lateral nozzle having to be additionally throttled by hand from outside by the driver or front-seat passenger with the air flap opened for ventilating the foot space to a sufficient extent, the first air-outflow orifice to the lateral nozzle is assigned a throttle diaphragm.

Abstract: A heat exchanger, especially a heating heat exchanger in the engine cooling circuit of a motor vehicle is disclosed. A forward-flow pipe opens at the top into a water box. A vent line of small cross-section is assigned to the forward-flow pipe and is guided to a compensating tank and there terminates below the liquid level. In order to obtain a simply constructed and at the same time highly effective venting facility, the vent line is brought into the operative position together with the fastening of the forward-flow pipe and is guided away from the highest point of the forward-flow water box to the compensating tank located at a distance therefrom.

Abstract: A device for regulating the heat output or heat capacity of a heat exchanger in an automotive vehicle with an actuating member to control the flow of a heat exchange medium and with a control device operating the actuating member. To provide input to the control device, signals are received from a highly rated internal temperature sensor and a lower rated heating air temperature sensor disposed at the outlet of the heat exchanger as well as a manually adjustable set point generator. The control device includes a pulse generator producing a triangular voltage of a constant frequency, with a differential amplifier for the signals of the temperature sensors as well as the set point generator. A comparator is provided for producing rectangular pulses in correspondence with the triangular voltage frequency, with a pulse width corresponding to the temperature signal of the differential amplifier. The heat exchanger is tubular and has a large ratio of heat exchange medium volume to heat dissipating surface area.