Abstract: A device for controlling a ventilation system in the interior of a motor vehicle includes a gas concentration determining arrangement to determine the exterior concentration of a gas in the exterior air surrounding the vehicle and to determine the interior concentration of the same gas in the air contained in the interior of the vehicle, and an air flow control arrangement, via which the proportion of circulating air and the proportion of fresh air from the surroundings of the vehicle in the air delivered to the interior by the ventilation system are controlled as a function of the determined interior concentration or the determined exterior concentration. The gas concentration determining arrangement is represented by a single gas sensor.

Abstract: The invention relates to a photometric gas sensor containing at least an infrared radiation source; a first reflector for deflecting to a second reflector an infrared radiation coming from an infrared radiation source; a second reflector for deflecting to an infrared detector the radiation coming from the first reflector; and an infrared detector.

Abstract: The invention relates to an air conditioner, in particular for use in motor vehicles, with a cooling circuit and a ventilation system, wherein the cooling circuit features an evaporator/heat exchanger (12) that is arranged in the ventilation system, and wherein a gas sensor (30) is provided in the ventilation system downstream from the evaporator/heat exchanger (12) to detect the rates of a refrigerant of the evaporator/heat exchanger (12) of the air conditioner in the conveyed air-conditioned air. It is provided that the gas sensor (30) is arranged at a narrow point (32) and/or in an area of turbulent flow of an air guidance channel (10) of the ventilation system. The invention also relates to a method to operate such an air conditioner.

Abstract: A device for controlling a ventilation system in the interior of a motor vehicle includes a gas concentration determining arrangement to determine the exterior concentration of a gas in the exterior air surrounding the vehicle and to determine the interior concentration of the same gas in the air contained in the interior of the vehicle, and an air flow control arrangement, via which the proportion of circulating air and the proportion of fresh air from the surroundings of the vehicle in the air delivered to the interior by the ventilation system are controlled as a function of the determined interior concentration or the determined exterior concentration. The gas concentration determining arrangement is represented by a single gas sensor.

Abstract: The invention relates to an air conditioner, in particular for use in motor vehicles, with a cooling circuit and a ventilation system, wherein the cooling circuit features an evaporator/heat exchanger (12) that is arranged in the ventilation system, and wherein a gas sensor (30) is provided in the ventilation system downstream from the evaporator/heat exchanger (12) to detect the rates of a refrigerant of the evaporator/heat exchanger (12) of the air conditioner in the conveyed air-conditioned air. It is provided that the gas sensor (30) is arranged at a narrow point (32) and/or in an area of turbulent flow of an air guidance channel (10) of the ventilation system. The invention also relates to a method to operate such an air conditioner.

Abstract: A device for detecting a leakage in a motor vehicle air conditioning system that utilizes carbon dioxide as the cooling material is provided. The device for detecting leakage includes: at least one sensor for rapid detection of especially high rate of increase of the carbon dioxide concentration and/or particularly high carbon dioxide concentration in the air of the passenger compartment; an evaluation device for evaluating the ascertained rate of increase and/or concentration; and at least one actuator which, in the case that the rate of increase and/or concentration exceeds a threshold value, performs a remedial action.