A galley cart system employs a housing with a door coupled to the housing, the door configured to be moved between a closed position and an open position. A vent plate in the housing communicates between a first compartment and a second compartment. A valve plate adjacent the vent plate is movable from a venting position when the door is in the closed position to a blocking position when the door is in the open position thereby preventing flow communication between the first and second compartment.