Do You Need to Turn on AC When Using Car Air Conditioning in Winter?
2 Answers
You don't need to turn on the AC button when using car air conditioning in winter. The reasons are as follows: 1. The car's heating system recycles waste heat and doesn't consume extra fuel. The warm air comes from the heat generated by the engine during operation: after the engine's cooling system dissipates heat from the engine, a fan directs this heat into the car's interior to provide warmth. When the heating is not in use, the fan stops, the heating vents close, and all the dissipated heat is released into the atmosphere. 2. The AC button controls the air conditioning compressor. In summer when using air conditioning, you must turn on the AC button to activate the cooling system. However, the heating system simply utilizes the car's internal heat circulation and doesn't require the air conditioning compressor to be engaged. Therefore, to use the heating system, you only need to adjust the air conditioning controls without activating the AC switch.
Throughout all these years of driving, I face the issue of using air conditioning every winter. While heating relies on engine waste heat, windows can fog up unnoticed, especially on rainy or snowy days, making visibility zero—super dangerous. Hitting the AC button—that little snowflake icon—instantly dehumidifies and clears the fog, restoring visibility in seconds. Though AC is mainly for cooling, in winter it serves as an anti-fog tool. Turn it off after a few minutes once the fog clears; fuel consumption increases slightly, but safety comes first. My advice: make it a habit—turn on AC to defog when needed, then switch it off to save fuel once clear; a dry cabin also helps prevent illness. Regularly check windows even when using heating—stay vigilant.
