Watertight vehicle airduct system

A vehicle comprising:

• a floor pan defining at least one cavity;
• a heat exchanger disposed within the at least one cavity and having an outlet duct;
• a passageway directing air through the heat exchanger and toward a wall of the at least one cavity;
• and
• a duct assembly fixedly attached to the wall of the at least one cavity and extending outwardly therefrom, the duct assembly having a housing having a tortuous path extending from an inlet of the housing to an outlet of the housing, the outlet of the housing pointing upward opposing and spaced below a bottom surface of the vehicle and extending away from ground to direct air exiting the outlet in a direction toward said bottom surface of the vehicle and away from ground and directly into an open environment beneath the vehicle;
• the outlet duct coupled to the inlet of the housing;
• the duct assembly having a door disposed proximate to the inlet of the housing, the door configured to permit air flow from the outlet duct into the housing through the inlet of the hosing and to restrict air flow from the housing into the outlet duct;
• the tortuous path including an upwardly extending portion and a downwardly extending portion with the downwardly extending portion disposed between the outlet of the housing and the upwardly extending portion;
• the duct assembly including a buoyant closure member disposed in the downwardly extending portion of the tortuous path, the buoyant closure member movable between an open position permitting flow between the inlet and the outlet of the housing and a closed position preventing flow between the inlet and the outlet of the housing, the buoyant closure member normally in the open position and moving from the open position to the closed position in response to a predetermined volume of water entering the housing through the outlet of the housing.