The differences in car air conditioning buttons are often overlooked.
Many drivers use cars without fully understanding the function of the air conditioning's internal and external air vents. Incorrect use can easily lead to fatigue and drowsiness during long drives.
Today, air conditioning is one of the basic, important, and mandatory amenities in a car to cool the interior and create a comfortable feeling for the occupants. The control panel usually has a button to switch between two modes: recirculating and circulating air (indicated by a curved arrow, inside the car), but few people pay attention to the difference and how to use it effectively.
Simply put, the recirculating air mode directs the air circulating within the cabin back to the air conditioning unit for faster cooling. The advantage of this mode is that it saves cooling time and maintains a stable temperature inside the vehicle, especially on hot days or when driving in polluted air conditions.
However, the disadvantage of using only recirculated air is that the air will not be refreshed. The amount of oxygen in the car gradually decreases, and CO2 also increases.2The accumulation of fumes from human breath leads to a feeling of suffocation and lack of oxygen. If this situation persists, those inside the vehicle may feel tired, lethargic, lose concentration, or even become sleepy. This can easily lead to accidents when driving continuously.
Conversely, the outside air intake mode draws air from the outside environment into the cabin, refreshing the airflow, providing more oxygen, and balancing CO2 levels.2Inside the car. Although the cooling effect isn't as fast as recirculating air and sometimes carries dust and unpleasant odors from outside, this mode is essential on long journeys.
In particular, for vehicles without an automatic switching system between the two modes, drivers should proactively switch to outside air after a certain period of time to ensure the air inside the car remains fresh.
When driving long distances, the proper use of both air intake modes is crucial for maintaining alertness and safety. Some car manufacturers now integrate features that automatically switch between recirculating and outside air to minimize the risk of oxygen deprivation in the cabin.
However, not all vehicles have this feature, so drivers need to understand how it works to adjust accordingly and avoid feeling drowsy or unfocused for no apparent reason.
