Do You Need to Turn on AC in Winter?

[JulianLynn]

You don't need to turn on AC in winter because the AC button in cars is the cooling switch, which is only used when the air conditioner is set to cold air. When using warm air inside the car, there's no need to turn on the AC button. Principle of Warm Air: When the car's air conditioner is heating, the compressor does not participate in the work. The blower blows the heat from the engine's cooling circulating water in the car's radiator into the car for heating, without requiring additional power from the engine. However, when the car has just started and the engine cooling water hasn't heated up enough for the air conditioner, it's best not to turn on the warm air immediately to avoid increasing fuel consumption. Precautions: Turn on AC when it's prone to fogging because when the car's cooling switch is turned on, the compressor will also start, making the air inside the car drier and helping to clear water fog on the windows. However, compared to using warm air alone, this method will increase the car's fuel consumption.