A conditioning system for a gas vehicle comprising a source of a gas in a compressed state, said gas being used for the operation of an engine of said gas vehicle, said system comprising a main heat exchanger configured to use a first conditioning fluid for conditioning an inner volume/object of said gas vehicle and a first heat exchanger positioned on a conduit connecting said source of said gas in said compressed state to said engine, said first heat exchanger being fluidly connected to said main heat exchanger and being configured to cool said first conditioning fluid thanks to the transition of said gas from said compressed state to an expanded state between an inlet and an outlet of said first heat exchanger; said conditioning system further comprising a second heat exchanger positioned on said conduit downstream with respect to said first heat exchanger and being fluidly connected to said main heat exchanger and to said engine in order to allow the passage of a second conditioning fluid inside said main heat exchanger and said second heat exchanger, said second heat exchanger being configured to overheat said gas in said expanded state in conduit thanks to the passage of said second conditioning fluid flowing from said engine between an inlet and an outlet of said second heat exchanger; said first conditioning fluid and said second conditioning fluid being the same fluid; characterized in that said conditioning system further comprises an electronic controlled volume flow valve, which is directly fluidly connected to said first heat exchanger, said second heat exchanger and said engine; said valve being configured to receive said second conditioning fluid from said second heat exchanger, to allow the passage of said second conditioning fluid to said first heat exchanger and to allow the passage of said second conditioning fluid to said engine; said valve being settable in a first configuration, in which it allows the passage of the majority of the engine cooling fluid in circuit and said second conditioning fluid from said second heat exchanger in circuit to said engine to cool it and only a few portion in conduit to said first heat exchanger to cool said inner volume/object of said gas vehicle; said valve being further settable in a second configuration, in which it allows the passage of only a few portion of said second conditioning fluid in the remaining portion of conduit and therefore in circuit from said second heat exchanger to said engine to cool it and the majority of the engine cooling fluid in circuit via circuit to said first heat exchanger to heat said inner volume/object of said gas vehicle. said conditioning system further comprising a second heat exchanger positioned on said conduit downstream with respect to said first heat exchanger and being fluidly connected to said main heat exchanger and to said engine in order to allow the passage of a second conditioning fluid inside said main heat exchanger and said second heat exchanger, said second heat exchanger being configured to overheat said gas in said expanded state in conduit thanks to the passage of said second conditioning fluid flowing from said engine between an inlet and an outlet of said second heat exchanger; said first conditioning fluid and said second conditioning fluid being the same fluid; characterized in that said conditioning system further comprises an electronic controlled volume flow valve, which is directly fluidly connected to said first heat exchanger, said second heat exchanger and said engine; said valve being configured to receive said second conditioning fluid from said second heat exchanger, to allow the passage of said second conditioning fluid to said first heat exchanger and to allow the passage of said second conditioning fluid to said engine; said valve being settable in a first configuration, in which it allows the passage of the majority of the engine cooling fluid in circuit and said second conditioning fluid from said second heat exchanger in circuit to said engine to cool it and only a few portion in conduit to said first heat exchanger to cool said inner volume/object of said gas vehicle; said valve being further settable in a second configuration, in which it allows the passage of only a few portion of said second conditioning fluid in the remaining portion of conduit and therefore in circuit from said second heat exchanger to said engine to cool it and the majority of the engine cooling fluid in circuit via circuit to said first heat exchanger to heat said inner volume/object of said gas vehicle.