Should the AC be turned on for heating in winter?

[OBriella]

In winter, there is no need to turn on the AC for heating because the working principle of the car heating system is different from that of cooling. The car heating system uses the heat emitted from the exhaust pipe and radiator to warm the air, which is then blown into the cabin by the fan, without the need to activate the compressor. The AC button in the car is for the cooling function of the air conditioning system. Pressing it activates the compressor, and in some models, an indicator light on the button will illuminate, while others may display a prompt on the central control screen. The car air conditioning system is designed to adjust and control the temperature, humidity, air cleanliness, and airflow inside the vehicle cabin to a comfortable state, providing a pleasant riding environment for passengers.

[StLola]

I'm in the car repair business and have seen many experienced drivers debating whether to turn on the AC button in winter. The heating system relies on engine heat, while the AC switch controls the air conditioning compressor, typically used for cooling. However, turning it on in winter helps quickly dehumidify the air, preventing window fogging that can obstruct visibility. Fogged windows are dangerous—for example, driving in snowy conditions with fogged-up glass can make it hard to see the road. Turning on the AC dries the air, solving the problem fast. Although compressor operation increases fuel consumption slightly (around 0.5 liters per 100 km), safety comes first, and this minor cost is worth it. I recommend keeping the AC on in humid or rainy conditions—summer goes without saying—but adjust as needed in winter. Develop the habit of turning on both the heater and AC when starting the car, setting a comfortable temperature. Remember to regularly check the AC system to avoid refrigerant leaks or compressor failure, which can reduce effectiveness.

[JaylaAnn]

I've been driving for decades. Should you turn on the AC in winter? From my personal experience, it's better to keep it on. In my early years driving long distances in the north, without the AC, the windows would often fog up, making it dangerous to wipe them constantly. Later, when I started using the AC, the automatic dehumidification kept the windshield clear and made driving much easier. The heater provides warmth, while the AC improves air quality, making the car more comfortable, especially when traveling with elderly or children. There might be a slight increase in fuel consumption, but it's manageable, and modern cars are designed to be fuel-efficient, so there's no need to worry. On rainy or humid days, I always keep the AC on; on sunny days, you can try turning it off, but don't ignore the risk of fogging. My approach is simple: after starting the car, adjust the temperature and fan speed, then toggle the AC button flexibly as needed.

[DiLaila]

Turning on the AC button while using the heater in winter is generally more reliable. The heater effectively prevents freezing but tends to accumulate moisture and cause fogging; the AC quickly dehumidifies, ensuring a clear windshield for safety. Without the AC, excessive fog can obstruct your view, especially in rainy or snowy conditions, posing greater risks. Although using the AC slightly increases fuel consumption, the impact is minimal. It's advisable to run it for a while before making adjustments. Set the heat to a sufficient level to keep the cabin warm while maintaining clear visibility.

[AbigailRose]

As a homemaker who frequently shuttles kids, I always turn on the AC with the heater during winter drives. Safety comes first - clear windows are essential for navigating school routes. The AC dries the air, keeping glass crystal clear, whereas turning it off allows moisture buildup that fogs windows and slows reaction time. Though fuel consumption increases slightly, it's worth it for my children's safety. Operation is simple: after starting the car, rotate the temperature dial to a comfortable setting and press the AC button for automatic operation. Regular cleaning of the AC filter maintains optimal efficiency.