Should You Use Internal or External Air Circulation for Car Heating in Winter?
4 Answers
In winter, it is recommended to use the internal air circulation mode for car heating. The internal circulation function effectively prevents external dust and harmful gases from entering the vehicle cabin, providing faster cooling and heating effects. The external circulation function supplements fresh air and maintains airflow between the inside and outside of the vehicle, ensuring clean air inside the cabin. The internal air circulation control is located below the front dashboard in the driver's compartment, while the external circulation control is positioned below the windshield on the passenger side in the engine compartment. The car air conditioning system is designed to regulate and control the temperature, humidity, air cleanliness, and airflow within the vehicle cabin to optimal conditions, providing passengers with a comfortable riding environment and reducing travel fatigue.
As a seasoned driver with ten years of experience, using the recirculation mode first is the most suitable way to turn on the heater in winter. Recirculation mode allows the air inside the car to circulate and heat up on its own, so the warm air builds up quickly, making the car warm in just a few minutes—especially when it’s freezing outside. This method saves time and fuel. On long drives or after sitting for a while, the air can become stale, leading to foggy windows or dizziness, so after about half an hour, it’s best to switch to fresh air mode to bring in outside air. I often drive on highways and find that switching modes this way maintains warmth while preventing window fogging, making it much safer. Remember to check the cabin air filter to ensure it’s not clogged, which can reduce efficiency. Using both modes wisely is the smart approach—don’t stick to just one.
I prioritize a healthy lifestyle, and during winter car use, I prefer using the external air circulation with the heater on. Although the internal circulation heats up faster, the air inside the car becomes stale, and the accumulated exhaled carbon dioxide can easily cause fatigue and drowsiness, affecting driving concentration. External circulation draws in fresh air from outside, maintaining high oxygen levels inside the car, making it feel refreshing and not stuffy. Of course, I use internal circulation for the first few minutes after starting the car to warm up the interior, then switch to external circulation to balance the temperature. Regularly cleaning the air conditioning system is also important to avoid dust allergies. This way, long drives are more comfortable, and breathing is smoother in winter.
I prioritize fuel efficiency and environmental friendliness, and using the recirculation mode for heating in winter is more cost-effective. Recirculation heats the existing air inside the car, so the engine doesn't need extra effort, resulting in lower fuel consumption and quick warming in the short term. If you always use fresh air mode, more cold air comes in, forcing the engine to work harder to heat it, which wastes fuel. However, during long drives, the air inside can get stale or foggy, so switch to fresh air mode for ventilation. With five years of driving experience, this practice has helped me save a lot on fuel costs annually and reduce carbon emissions. Simply put, recirculation is best for energy saving, while fresh air mode is for emergency air refreshment.
