Should the AC be turned on in a car during winter?

[DeArthur]

In winter, there is no need to turn on the AC in a car, as it is the switch for the air conditioning compressor. In summer, using the air conditioning requires pressing the AC button to activate the cold air. However, the warm air utilizes the car's internal heat circulation and does not require the air conditioning compressor to be turned on. To use the warm air, simply adjust the air conditioning buttons. When the car starts, the engine begins to warm up. Wait until the engine temperature gauge needle points to the middle position, then turn on the warm air conditioning and set the air circulation to external circulation to expel the cold air inside the car. After 2 to 3 minutes, switch the air circulation to internal circulation. When there is a significant temperature difference between the inside and outside of the car, the front windshield is prone to fogging. Simply adjust the warm air outlet direction to the position that blows air onto the front windshield.

[Hernandez]

Should you turn on the AC when using the car heater in winter? With over a decade of driving experience, I’ve found it absolutely necessary to use the AC. The AC isn’t just for summer—it helps dehumidify and prevent fogging, ensuring clear visibility. Especially in damp, cold weather, windows tend to fog up, obstructing your view. Turning on the AC activates the compressor to remove moisture, then blows warm air, which clears fog incredibly fast. This eliminates the hassle of manually wiping the windshield and enhances driving safety. Although using the AC consumes slightly more fuel, the trade-off for avoiding potential accidents is well worth it. In auto-climate mode, simply press AUTO to set the temperature, and the system balances everything automatically—no need to micromanage. My advice: make it a habit not to rush turning off the AC during cold starts; wait a few seconds for temperature stabilization. Don’t sacrifice visibility just to save a bit of fuel.

[DelBrooklyn]

I prefer to explain the AC topic from the mechanism of the car. Turning on the AC in winter is absolutely necessary because it activates the compressor to dehumidify, preventing window fogging. The principle is that the air is cooled to remove moisture and then heated for output, making it drier and more effective than just blowing hot air alone. Especially in sub-zero temperatures when frost forms, AC defrosts faster. Most modern cars have automatic climate control—pressing the AUTO button will automatically manage the AC on/off, making it convenient and reliable. The additional fuel consumption is negligible, maybe just a small extra cost, but what you gain is clear visibility, avoiding major rear-end accidents. Check if your AC system is working properly—don’t wait until there’s a problem to fix it.

[OAngelina]

I've driven in various road conditions, and safety-wise, turning on the AC in winter is crucial. Without the AC, the windows fog up completely, blurring visibility, which is especially dangerous on highways. When the AC is on, the compressor helps dehumidify, keeping the glass clear, particularly during rain or snow. Hot air alone doesn't dehumidify and actually causes faster fogging. It's recommended to turn on the AC right from the start, combined with the heater for quick defogging. This might increase fuel consumption slightly, but it significantly reduces the risk of accidents. Don't forget regular AC maintenance either; cleaning the filters can improve its effectiveness.

[VonGavin]

From an economic perspective, it's worth spending a little extra to run the car's AC in winter. The AC dehumidifies and prevents fogging, avoiding visibility-related accidents that could save on repair costs. Running the AC does consume fuel, but not much: modern cars with efficient compressors only see a slight increase in fuel consumption – for example, driving 100 km might cost an extra 2-3 yuan in fuel. Setting the temperature around 26°C and using recirculation mode minimizes energy use. Not using the AC leads to more fogging, which wastes fuel from frequent windshield wiping. Running the AC is a small investment with big returns in safety and convenience.

[DelAxel]

When I was a new driver, I also had doubts about using the AC in winter. Later, experienced drivers taught me to always turn on the AC for dehumidification, not for cooling. When the windshield fogs up, turning on the AC along with the heater can clear the fog in just three seconds. Automatic climate control systems are the best to use: press the AUTO button, set a comfortable temperature, and let the car handle the dehumidification. If you don't turn on the AC, the fog will keep coming back, affecting braking distance. The fuel consumption is minimal, so don't worry about wasting gas. Safety comes first, and with more practice, you'll get used to it.