Is it better to use internal or external air circulation when turning on the heater in the car during winter?
2 Answers
The correct operation method is: 1. Start the car and warm it up while driving. Wait until the water temperature gauge pointer reaches the middle position before turning on the heater. 2. Set the air circulation to external circulation to expel the cold air inside the car, then switch to internal circulation after about 3 minutes. Below are the relevant details: 1. Turn off the A/C when using the heater in winter. 2. The A/C function in a car can be understood as the air conditioning cooling switch. When the A/C light is on, it means the air conditioning compressor is activated, which increases engine load and fuel consumption. 3. The heating principle of the heater utilizes the heat generated by the engine itself, which is delivered into the car through the air conditioning ducts without the involvement of the compressor. Therefore, turning on the A/C in winter does not enhance the heating power but instead wastes the compressor's effort unnecessarily. 4. Internal circulation means the air inside and outside the car does not exchange, so the advantage of internal circulation is that it can effectively maintain the "insulation" effect. In hot summers, it can quickly achieve cooling, and in cold winters, it can rapidly retain warmth. In cases of poor external air quality (such as during smog), internal circulation can also effectively purify the air.
In winter when turning on the car heater, I prefer to first use the external circulation mode for a few minutes to remove humidity inside the vehicle and prevent windshield fogging that could blur vision. Then I switch to internal circulation to allow the warm air to heat up the cabin quickly, maintaining a cozy warmth that gives me a strong sense of security while driving. Window fogging is extremely dangerous, especially during winter's rainy and snowy conditions when roads are slippery. From my experience, preventing condensation requires balancing both modes - don't stubbornly use just one setting. Occasionally switching back to external circulation mid-drive refreshes the air and prevents stuffiness that could cause dizziness. Remember to maintain the AC system regularly and never overlook these safety details, because safe driving is ultimately more important than temporary warmth - it's not worth risking safety for momentary comfort.
