Abstract: An air conditioning and heating unit for automotive vehicles includes a blower, an evaporator and a heat exchanger disposed in a synthetic resin housing providing with integral air discharge outlets for the headroom, footroom and center plane of a passenger compartment and for windshield defrosting. The evaporator and the heat exchanger are arranged relative to one another so that the paths of the hot air and of the cold air from the blower to inlet openings of the various air discharge outlets are the same and so that the path of the hot air from the evaporator to the inlet openings is 1.3 to 1.8 times longer than the path of the cold air from the evaporator to the air outlet ducts. The inlet openings of the air outlet ducts emanate from a common chamber in the housing.

Abstract: An assembly for transmitting rotary motion from an actuator knob to an operating mechanism in the heating, air conditioning and ventilating system of an automotive vehicle comprises a rack and pinion rotatably connected to the actuator knob. The rack is linked to the operating mechanism via a positioning lever and an intermediate lever.

Abstract: A single-piece plastic fan wheel for a radial fan comprises a hub, a blade ring having fan blades and an intermediate piece interconnecting the hub and the blade ring. The hub comprises an inner hub ring attachable to the drive shaft of a motor and an outer hub ring connected to the inner hub ring by a plurality of axially and radially extending resilient strips which serve to damp tangential vibrations emanating from the motor owing to pulsations in the torque output thereof.