Do you need to turn on the AC when using the car heater?
2 Answers
When using the car heater, there is no need to turn on the AC switch. Reason: The heating system in a car does not require the compressor to work for heating; it directly uses the hot air from the engine's cooling system as the heater. Therefore, you do not need to turn on the AC switch when using the heater in winter. Methods for switching between cooling and heating in a car's air conditioning system: 1. Rotating knob: Generally, the air conditioning switch in a car is a rotating knob with two ends. One end is for cooling (blue), and the other end is for heating (red), each marked with different intensity levels to adjust the cooling or heating strength. 2. Cooling: If you need to use the air conditioner in summer, rotate the air conditioning switch to the blue end and turn on the AC switch to activate the compressor for cooling. 3. Heating: If you need heating in winter, rotate the air conditioning switch to the red end without turning on the AC switch. When the air conditioning is not in use, simply rotate the knob to the off position.
Whether to turn on the air conditioning when using the heater depends on the situation. Normally when I drive in winter, the heating mainly relies on the engine's heat—just turning on the fan is enough, and there's no need to activate the air conditioning compressor, as it consumes more fuel and adds extra load. However, during humid and cold days or rainy and foggy weather in the south, I always press the defrost mode, which automatically activates the air conditioning's dehumidification function to quickly clear fog and improve visibility. After starting the car, if the cabin is dry, I simply set the temperature for warm air; if it's humid, turning on dehumidification makes it more comfortable. For long-term use, regular checks of the air conditioning system are necessary to avoid malfunctions. In short, it's not always required, but using it for dehumidification can significantly enhance comfort and safety.
