Air-conditioning system for a vehicle

A control device for an air-conditioning system, comprising:

• a fresh air path for communicating fresh air leading from a fresh air inlet to an air outlet;
• a circulating air path for communicating circulating air leading from a circulating air inlet to the air outlet;
• a control valve adjustable between a circulating position in which the control valve closes the fresh air path and opens the circulating air path, and a fresh air position in which the control valve closes the circulating air path and opens the fresh air path;
• at least one non-return check valve including a valve member cooperating with a passage opening, the valve member secured to an inner side of the control valve facing the air outlet in a stationary region, the valve member including an elastic mobile region at least one of movable and adjustable relative to the control valve;
• wherein the valve member in the fresh air position is movable to (i) open the passage opening to a circulating air flow in a through-flow direction from the circulating air inlet to the air outlet, and (ii) block the passage opening to stop the circulating air flow in an opposite direction.