Is it Better to Use Internal or External Air Circulation in Cars During Winter?
2 Answers
During winter, cars should initially use internal air circulation and switch to external circulation once the interior warms up. The heating system in winter can primarily rely on internal circulation with external circulation as a supplement, alternating between the two. This approach ensures a warm cabin while preventing the buildup of carbon dioxide levels that could compromise driving safety. Both internal and external air circulation are necessary for car heating in winter. Internal air circulation closes the external heating intake grille, sealing the cabin completely to recirculate interior air. However, prolonged use leads to rising temperatures and decreasing oxygen levels, potentially causing hypoxia in occupants. Therefore, it's advisable to periodically activate external circulation to introduce fresh air, which is then heated by the vehicle's electric heating grid.
As a driver with over a decade of experience, I always struggle with the air conditioning mode in winter. Initially, I used the recirculation mode for faster heating, which quickly warmed up the car and made it cozy. However, one time while driving in snowy mountains, the windshield fogged up heavily, blurring my vision and nearly causing an accident. That’s when I realized the importance of fresh air mode. My current practice is: after starting the car, I use recirculation to heat up quickly, then switch to fresh air mode after about 5-10 minutes when the interior temperature stabilizes, to prevent fogging. On rainy or snowy days or when there are many passengers, I use fresh air mode more often to avoid stuffiness. Long-term recirculation also wastes fuel, while fresh air mode, though slightly cooler, is healthier and more worry-free. Winter driving safety comes first—I recommend flexibly switching modes rather than sticking to one rigidly.
