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

1 . 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.

2 . The combined system according to claim 1 , wherein the second mode is a drive mode initiated only if a determined target substance concentration determined in the pre-drive mode is below a predetermined level.

3 . The combined system according to claim 2 , further comprising a park mode wherein the air quality of the vehicle compartment is monitored and at least partly controlled by performing carbon dioxide determination with the sensor unit and controlling the settings of the HVAC system at least partly based on the carbon dioxide determination performed during the park mode.

4 . The combined system according to claim 2 , wherein the drive mode comprises the central control unit controlling the HVAC system to increase the intake of external air if a determined carbon dioxide level is above a first predetermined upper level, and reduce the external air intake if the carbon dioxide level is below a first predetermined lower level.

5 . The combined system according to claim 4 , wherein the drive mode comprises the central control unit activating an alarm function if the HVAC system is not capable of maintaining the carbon dioxide level below the first predetermined upper level.

6 . The combined system according to claim 3 , wherein the park mode comprises the central control unit controlling the HVAC system to increase the external air intake if a determined carbon dioxide level above a second predetermined upper level, and reduce the external air intake if the carbon dioxide level is below a second predetermined lower level.

7 . The combined system according to claim 6 , wherein the park mode comprises the central control unit being arranged to monitor a status of a battery supplying the HVAC system with power and activating an alarm function if the battery status indicates that the power will not be enough to maintain the HVAC system at a present setting required for maintaining a carbon oxide level below the second predetermined upper limit.

8 . The combined system according to claim 6 , further comprising the park mode comprises the central control unit activating an alarm function if the HVAC system is not capable of maintaining the carbon dioxide level below the second predetermined upper level.

9 . The combined system according to claim 1 , wherein the sensor unit comprises a temperature sensor and the temperature of the air in the vehicle compartment is determined using the sensor unit and the settings of the HVAC system will depend on both the determined temperature and a determined carbon dioxide level.

10 . A method of operating a vehicle mounted combined system for monitoring and controlling air quality of a vehicle compartment and for determining of target substance relating to a driver/user of the vehicle, wherein the system comprises:

a sensor unit arranged to analyze air from the vehicle compartment and to determine a concentration of a target substance and the 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, and

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,

the method comprises steps of:

in a pre-drive mode, determining the concentration of the target substance in the air sample using carbon dioxide as the tracer substance using the sensor unit;

in at least a second mode, monitoring the air quality of the vehicle compartment and at least partly by performing carbon dioxide determination and using the sensor unit and controlling the settings of the HVAC system at least partly based on the carbon dioxide determination.

11 . The method according to claim 10 , wherein the second mode is a drive mode initiated only if the determined target substance concentration determined in the pre-drive mode is below a predetermined level.

12 . The method according to claim 11 , further comprising a park mode wherein the air quality of the vehicle compartment is monitored and at least partly controlled by performing carbon dioxide determination with a same sensor unit and controlling the settings of the HVAC system at least partly based on the carbon dioxide determination performed during the park mode.

13 . The method according to claim 11 , wherein the drive mode comprises the central control unit controlling the HVAC system to increase an intake of external air if the determined carbon dioxide level is above a first predetermined upper level, and reduce the intake of external air if the carbon dioxide level is below a first predetermined lower level.

14 . The method according to claim 13 , wherein the drive mode comprises the central control unit activating an alarm function if the HVAC system is not capable of maintaining the carbon dioxide level below the first predetermined upper level.

15 . The method according to claim 12 , wherein the park mode comprises the central control unit controlling the HVAC system to increase the external air intake if the determined carbon dioxide level is above a second predetermined upper level, and reduce the external air intake if the carbon dioxide level is below a second predetermined lower level.

16 . The method according to claim 15 , wherein the park mode comprises the central control unit monitors a status of a battery suppling the HVAC system with power and activating an alarm function if the battery status indicates that the power will not be enough to maintain the HVAC system at a present setting required for maintaining a carbon oxide level below the second predetermined upper level.

17 . The method according to claim 16 , further comprising the park mode comprises the central control unit activating an alarm function if the HVAC system is not capable of maintaining the carbon dioxide level below the second predetermined upper level.

18 . The method according to claim 12 , wherein the sensor unit provides a temperature of the air in the vehicle compartment and the settings of the HVAC system will depend on both a determined temperature and the determined carbon dioxide level.