Do You Need to Turn on AC in Winter?
4 Answers
If the windshield fogs up severely in winter, you can turn on the AC. The AC is the cooling switch of the car's air conditioning system, and it is not necessary to turn it on in other situations. The car's air conditioning is an important comfort feature that can provide both cooling and heating. During winter and summer, the car's air conditioning is used almost every day. When the car's air conditioning is in cooling mode, the compressor clutch engages, and the engine drives the compressor to operate. While running, the compressor continuously compresses the refrigerant and delivers it to the evaporator. Inside the evaporator, the refrigerant expands and absorbs heat, cooling the evaporator. The cooled evaporator then cools the air blown by the blower, allowing the car's air conditioning vents to blow cold air.
I think using the AC in winter is quite necessary, especially when the windows fog up and visibility is poor. Once during winter, I encountered rain and snow while driving. I had the heater on full blast but forgot to turn on the AC, and the windshield became completely fogged up, nearly causing an accident. Since then, I've learned that turning on the AC can quickly dehumidify and defog, ensuring clear visibility and safety first. Although using the AC may increase fuel consumption slightly, it's worth it compared to the danger of driving. Additionally, turning on the AC can circulate the air inside the car, reducing stuffiness, especially during long trips when passengers feel more comfortable. However, don't leave it on all the time—turn it off once the fog clears to save a bit of fuel. In short, safety is the top priority, and it's a good habit to turn on the AC along with the heater during winter rain or snow.
Whether to turn on the AC in winter depends on the situation. As an owner who prioritizes fuel efficiency, I usually avoid using the AC because it consumes more fuel. However, I find it annoying when the heater causes fogging in winter, so I only turn on the AC briefly to dehumidify when the fog gets heavy, then turn it off immediately once the fog clears. Without the AC, you can use the external air circulation to defog, though it’s slower and colder. Additionally, running the AC for too long might affect its lifespan, so I limit usage to avoid this. Overall, I recommend using the AC when fogging is severe; otherwise, saving fuel is fine. If the weather is dry and there’s no fog, I don’t use the AC at all and rely solely on the heater, which is economical and eco-friendly. Remember to check window seals to reduce the source of fogging.
Turning on the AC in winter is actually useful as it works like a dehumidifier. I understand many people think the AC only cools, but when heating is on in winter, the temperature difference between the warm interior and cold exterior causes windows to fog up easily. Using the AC dries the air faster, quickly dispersing the fog. Many cars' automatic climate control systems activate the AC for dehumidification when heating is turned on, making it convenient and hassle-free. If you prefer manual control, you can defog without the AC, but it requires longer use of high fan speed, which is noisier. Slightly higher fuel consumption in winter is normal—don’t worry about using the AC; just turn it off once the fog clears. Maintaining clear visibility is the top priority.
