Air conditioning system, in particular for a motor vehicle

The system (1) has an evaporator (2), a heater (4) and a mixing flap (5) arranged downstream to the evaporator and deflecting air stream flowing from the evaporator. The mixing flap is formed in arc-shape. The arc-shaped mixing flap is arranged between an upper end (2a) or a lower end (2b) of the evaporator and a deep point (4a) of the heater. A heating device is arranged near upper regions of the evaporator. The mixing flap extends between the upper end of the evaporator and the deep point of the heater. The air stream is guided into a mixing chamber (7).