Air conditioning system for a cabin of an air or rail transport vehicle, comprising: - a pneumatic turbine engine that comprises at least one compressor and at least one turbine (126, 226, 326, 426) and is connected by a mechanical shaft extending along an axis, referred to as the turbine engine axis (132, 232, 332, 432), said turbine comprising an air inlet and an air outlet, and - a water extraction loop that comprises a heater (110, 210, 310, 410), a condenser (112, 212, 312, 412), and a water separator (114, 214, 314, 414), is arranged fluidically between an air outlet of the compressor and the air inlet of said turbine (126, 226, 326, 426), and is configured to be able to dry the air supplied to said turbine (126, 226, 326, 426), - said heater (110, 210, 310, 410), said condenser (112, 212, 312, 412), and said water separator (114, 214, 314, 414) being arranged in series, forming the air inlet of said turbine (126, 226, 326, 426); - said heater (110, 210, 310, 410) is arranged on the turbine engine axis (132, 232, 332, 432) or around said axis; - said condenser (112, 212, 312, 412) being arranged on the turbine engine axis (132, 232, 332, 432) or around said axis; - said water separator (114, 214, 314, 414) being arranged on the turbine engine axis (132, 232, 332, 432) or around said axis, characterized in that - said heater (110, 210, 310, 410) is cylindrical and surrounds the axis (132, 232, 332, 432) of the turbine engine and the turbine (126, 226, 326, 426), so that the outlet of the cold pass of the heater opens directly into the air inlet of the turbine. - a pneumatic turbine engine that comprises at least one compressor and at least one turbine (126, 226, 326, 426) and is connected by a mechanical shaft extending along an axis, referred to as the turbine engine axis (132, 232, 332, 432), said turbine comprising an air inlet and an air outlet, and - a water extraction loop that comprises a heater (110, 210, 310, 410), a condenser (112, 212, 312, 412), and a water separator (114, 214, 314, 414), is arranged fluidically between an air outlet of the compressor and the air inlet of said turbine (126, 226, 326, 426), and is configured to be able to dry the air supplied to said turbine (126, 226, 326, 426), - said heater (110, 210, 310, 410), said condenser (112, 212, 312, 412), and said water separator (114, 214, 314, 414) being arranged in series, forming the air inlet of said turbine (126, 226, 326, 426); - said heater (110, 210, 310, 410) is arranged on the turbine engine axis (132, 232, 332, 432) or around said axis; - said condenser (112, 212, 312, 412) being arranged on the turbine engine axis (132, 232, 332, 432) or around said axis; - said water separator (114, 214, 314, 414) being arranged on the turbine engine axis (132, 232, 332, 432) or around said axis, characterized in that - said heater (110, 210, 310, 410) is cylindrical and surrounds the axis (132, 232, 332, 432) of the turbine engine and the turbine (126, 226, 326, 426), so that the outlet of the cold pass of the heater opens directly into the air inlet of the turbine. - said heater (110, 210, 310, 410), said condenser (112, 212, 312, 412), and said water separator (114, 214, 314, 414) being arranged in series, forming the air inlet of said turbine (126, 226, 326, 426); - said heater (110, 210, 310, 410) is arranged on the turbine engine axis (132, 232, 332, 432) or around said axis; - said condenser (112, 212, 312, 412) being arranged on the turbine engine axis (132, 232, 332, 432) or around said axis; - said water separator (114, 214, 314, 414) being arranged on the turbine engine axis (132, 232, 332, 432) or around said axis, characterized in that - said heater (110, 210, 310, 410) is cylindrical and surrounds the axis (132, 232, 332, 432) of the turbine engine and the turbine (126, 226, 326, 426), so that the outlet of the cold pass of the heater opens directly into the air inlet of the turbine.