System and method for monitoring and controlling air quality in a vehicle compartment

A vehicle mounted combined system for monitoring and controlling air quality of a vehicle compartment and for determining of a target substance relating to a driver/user of the vehicle, the system comprising:

• a sensor unit arranged to analyze air from the vehicle compartment and to determine a concentration of the target substance and a concentration of carbon dioxide in an air sample, and wherein the sensor unit is arranged to use carbon dioxide as a tracer substance to determine the concentration of the target substance;
• a heat, ventilation and air conditioning system (HVAC system), arranged to have at least one air intake mode drawing external air into the vehicle compartment and one recirculation mode circulating air in the vehicle compartment and the HVAC system configured to regulate a flow and amount of intake air by changing settings of the HVAC system;
• a central control unit arranged to control both the sensor unit and the HVAC system, and wherein the central control unit is arranged to set the HVAC system and the sensor unit in at least two different modes of operation:
• a pre-drive mode comprising determination of the concentration of the target substance in the air sample using carbon dioxide as the tracer substance;
• at least a second mode wherein the air quality of the vehicle compartment is monitored and at least partly controlled by performing carbon dioxide determination and controlling the settings of the HVAC system at least partly based on the carbon dioxide determination;
• and
• wherein the sensor unit is arranged to during the pre-drive mode determine the concentration of the target substance in the air sample using carbon dioxide as the tracer substance, and during second mode the sensor unit is arranged to provide a measure of the air quality of the vehicle compartment by determining the carbon dioxide concentration.