A ventilation tube system for breathing gas for ventilating patients is provided, the system having a first inhalation tube (1) connectable to a respiratory humidifier (3) and to a Y-piece (5)； a second inhalation tube (7) connectable to a respirator (9) and to the respiratory humidifier (3)； and an exhalation tube (11) connectable to the respirator (9) and to the Y-piece (5)； wherein at least certain portions of the first inhalation tube (1) and the exhalation tube (11) each comprise tube heaters having at least one heating wire (15, 17) wherein each of the tube heaters is controllable by a power supply and control unit inside the respiratory humidifier (3) wherein a power supply line (13) of the tube heater of the exhalation tube (11) starts from a link of the second inhalation tube (7) at the respiratory humidifier (3) and proceeds from there via the second inhalation tube (7) and a connecting element (21) separate from the respirator (9).
