VEHICLE AIR CONDITIONING SYSTEM

The invention relates to a vehicle air conditioning system (10) for controlling the air in a vehicle internal compartment (12), having a blower unit (14) that comprises an air inlet (16) and also an air outlet (20) and can generate an air flow from the air inlet (16) to the air outlet (20); a ventilation duct (22) that connects the air outlet (20) of the blower unit (14) to the vehicle internal compartment (12); an evaporator (24) that is arranged in the ventilation duct (22), and a CO 2 sensor (26) for monitoring a CO 2 concentration in the air (18), wherein the CO 2 sensor (26, 26') is arranged upstream of the evaporator (24) in the vehicle air conditioning system (10).