An air conditioning system includes an intake housing with a fresh air opening and a recirculation air opening, a filter housing to admit an air filter and a fan housing with a fan for intake by suction of air through the intake housing and directing the air through the filter housing. The fresh air opening and the recirculating air opening are aligned in a common horizontal direction and in a vertical direction one above the other. The recirculating air opening is situated in the gravitational direction beneath the fresh air opening. Between the fresh air opening and the recirculating air opening a separation area is configured, with drainage means in such a way that the fluid penetrating into the fresh air opening, when flowing over the drainage means is directed past the recirculating air opening in a receiving area placed below the recirculating air opening.