A heating, ventilation and/or air conditioning system (10) for an automobile vehicle, including a heating, ventilation and/or air conditioning housing (100) capable of allowing the thermal treatment of an air conditioning airflow to be used to maintain a desired temperature within the cabin, the heating, ventilation and/or air conditioning housing (100) having a primary distributor (132b, 133b, 134b) for the air conditioning air within the vehicle cabin so as to define a limited number of distribution configurations. The heating, ventilation and/or air conditioning system (10) includes an additional module (200) having additional distributors (212b, 213b) for the air conditioning airflow out of the cabin.