The invention relates to a device (1) with a dual air conditioning stream for a motor vehicle, comprising a chamber (2) containing an evaporator (3) and a radiator (4). A lower air stream admitted via a lower inlet (6) passes in succession through a lower portion of the evaporator (3) and of the radiator (4) before being discharged via a lower outlet (7). An upper air stream admitted via an upper air inlet (9) passes in succession through an upper portion of the evaporator (3) and of the radiator (4) before being discharged via an upper outlet (12, 13, 14). The device according to the invention comprises a first distribution flap (17) situated between the evaporator (3) and the radiator (4) and a second distribution flap (18) situated between the radiator (4) and the air outlets (12, 13, 14). Each flap divides the lower stream from the upper stream having an edge running along one face of the radiator (4) while at the same time being moveable between an upper position and a lower position.
