Air conditioning unit for a motor vehicle and climate control system with the air conditioning unit having a casing with at least one first air inlet for the intake of fresh ambient air and one second air inlet for the intake of circulating air from a passenger compartment, as well as an air guiding device in each case for independently varying flow cross sections of the air inlets, the air guiding device in each case is designed as an air flap which is arranged movably mounted between two end positions, a bypass flow duct with a ram pressure air guiding device is formed for the first air inlet, and the ram pressure air guiding device is arranged as an air flap movably mounted between two end positions and is designed in such a way as to fully close the bypass flow duct in an end position.

A vehicle air-conditioning apparatus includes emergency dampers switchable between opening states for opening emergency vents and closing states for closing emergency vents. A control device switches the emergency dampers from the closing states to the opening states while keeping an indoor fan operating, when determining that refrigerant is leaked from a refrigerant circuit on the basis of results of detection by refrigerant leakage detectors. An indoor unit chamber includes supply air guiding sub-chambers for guiding the internal air delivered by the indoor fan to supply openings. The emergency vents are included in the supply air guiding sub-chambers. The indoor fan forms flows of the internal air with the air pressures in the supply air guiding sub-chambers being higher than the atmospheric pressure.