High CO2 levels inside a car can cause drowsiness

Opening a car window for ventilation is no longer as necessary as it once was with more advanced climate control systems in modern cars.

However, being cocooned within the cabin of a car with all windows fully closed and with the air recirculation button on can also lead to an increase in CO2 levels.

High concentrations of CO2 inside the cabin can cause drowsiness and impact a driver’s concentration levels.

In 2013, Hyundai regarded the issue as one that needed to be addressed and for its 2014 Genesis models introduced a world-first CO2 cabin air sensor. The sensor automatically vents the passenger compartment when CO2 levels in the cabin rise higher than 2000 parts per million (ppm). The level of CO2 concentration in the outside atmosphere is around 400ppm.

Other manufacturers, including BMW and Volkswagen, have also implemented ways to better manage the cabin air quality of their cars, such as the capability to measure outside air quality and temporarily restrict its entry into the cabin.

In inclement weather, when you’d prefer not to roll down your car’s windows, we recommend ensuring that the recirculation button is set to outside air mode.