Should You Turn On the AC When Using the Car Heater in Winter?

[DiBrody]

Using the heater only requires adjusting the air conditioning buttons, and there's no need to turn on the A/C. A/C stands for Air Control or Air Conditioning, and its function in a car can be understood as the switch for the air conditioning cooling system. When the A/C light is on, it means the compressor is activated, increasing engine load and fuel consumption. In summer, when using the air conditioning, you must turn on the A/C. However, the heater simply utilizes the car's internal heat circulation and does not require the compressor to be activated. Here are some tips for using the heater: 1. The prerequisite for using the heater is that the engine must continue to operate; otherwise, it may lead to incomplete fuel combustion. The resulting high concentration of carbon monoxide could potentially enter the enclosed car interior in small amounts along with the circulating warm air. 2. If passengers in the car remain asleep for an extended period under these conditions, there is a risk of carbon monoxide poisoning. Prolonged exposure can lead to unconsciousness and even life-threatening situations. Therefore, it is crucial to avoid sleeping in the car with the heater on during winter.

[DiLuna]

I usually drive my kids to school, and in winter when using the heater, I generally don't turn on the AC button because the heat from the engine's residual warmth is sufficient and doesn't consume extra fuel. However, on rainy or snowy days or when there are many people in the car breathing heavily, the windows tend to fog up easily. Turning on the AC can quickly dehumidify the air, making the fog disappear faster. Using the AC does increase fuel consumption as the compressor works and burns a bit more fuel, so I only turn it on when there's fog and turn it off immediately after use. This operation is simple and safe, avoiding accidents caused by blurred vision. Additionally, regularly checking the cabin air filter ensures normal dehumidification performance, making winter driving more reassuring.

[SanOmar]

I always drive with fuel efficiency and environmental protection in mind. In winter, I never turn on the AC when using the heater. The AC engages the air conditioning compressor, which increases engine load, consumes more fuel, and emits more carbon. The heater utilizes waste heat from the engine - it's free and efficient, requiring no AC involvement. I only briefly activate the AC for defogging when window condensation becomes severe, then immediately turn it off. This ensures clear visibility while minimizing unnecessary fuel consumption and pollution. My recommendation: develop the habit of turning on the heater first after starting the car, then assess fogging conditions before deciding. Long-term fuel savings benefit both your wallet and the environment.

[GenesisRose]

I just got my driver's license and learned that turning on the AC can help defog the windows when using the heater in winter. The AC button controls the air conditioning, and turning it on won't make the car colder but will dry the air to prevent window fogging. If there's no fog, keeping the AC on just wastes fuel. My usual practice is to turn on the heater first, then decide based on the weather: turn on the AC for defogging on humid or cold days, and turn it off on dry days. This approach is convenient and helps avoid unnecessary fuel consumption caused by incorrect operations as a beginner. Remember to use the external circulation mode to let fresh air in for better results.

[Penelope]

I've been driving for decades, and whether to turn on the AC in winter depends on the situation. Turning off the AC saves fuel and reduces engine load as the compressor isn't working; turning it on quickly defogs the windshield, clearing mist instantly. My advice is to turn on the heater after starting the car, and if the windows fog up, briefly turn on the AC until the mist disappears, then turn it off. This balances comfort and efficiency. The heating system itself is reliable with excellent performance, while the AC is just a supplementary tool. Experience tells me that in areas with frequent rain or snow, using the AC more often is necessary, but otherwise, keeping it off is most economical.