Abstract: The invention relates to an air conditioning device for the passenger compartment of a vehicle, said device comprising a first closed loop (BF) which contains an evaporator (BF5), through which an air stream (F) may flow, and in which a first coolant may flow such as to transfer cold to said air stream in the evaporator. According to said invention, the device comprises a second closed loop (BS) in which a second coolant may flow between the evaporator (BF5) and a tank (BS2), such as to receive cold from the first coolant in the evaporator for storing the same in the tank and returning to the air stream in the evaporator, according to the cooling capacity, produced by the first loop and to the air conditioning needs.