Heating, ventilation and/or air-conditioning device for a motor vehicle

A heating, ventilation, and/or air-conditioning device for a motor vehicle includes a housing defining a flow channel for an air flow, in which are arranged a first heat exchanger and a second heat exchanger. The first and the second heat exchangers are inscribed in substantially orthogonal planes. The heating device includes a bypass path of the second heat exchanger and a plurality of air outlet ducts, each air outlet duct being configured to guide the air flow toward different regions of a vehicle passenger compartment. A mixing flap including a sliding door is arranged in the flow channel so as to be able to close the bypass path and/or the second heat exchanger and a second distribution flap including a sliding door is arranged so as to be able to at least partially close a first of said plurality of air outlet ducts.