Do You Need to Turn on AC When Using Car Heater?
2 Answers
You don't need to turn on AC when using the car heater. The AC button in a car controls the air conditioning compressor, which is essentially the cooling switch. The warm air comes from the heat generated by the coolant circulating in the engine, which is then delivered into the cabin through the air delivery system without requiring the air conditioning compressor to be activated. Therefore, there's no need to turn on the AC switch when using the heater in winter. Precautions for using car air conditioning: 1. Turn off A/C during startup and rapid acceleration: Since the air conditioning (non-independent type) consumes some engine power, it's best to turn off the A/C when starting or accelerating rapidly, then turn it back on after the car is moving. This prevents engine power shortage during acceleration and startup while also saving fuel. 2. Control air vent direction: Based on the principle that cold air sinks and warm air rises, drivers should adjust the air vents upward when using cooling and downward when using heating. 3. Don't immediately turn on AC after sun exposure: After a car has been exposed to the sun, the interior temperature is usually very high. In such cases, drivers shouldn't immediately turn on the air conditioning. It's better to first open the windows for ventilation and wait for the hot air to dissipate before turning on the AC.
This question reminds me of my long-distance driving experience last winter. Turning on the heater actually has nothing to do with the AC button. The car's heating system utilizes waste heat generated by the engine itself and doesn't consume extra gasoline. Once the coolant temperature gauge rises to the middle position, simply turn on the fan to get warm air. However, I must specifically remind you that pressing the AC button defogs the windshield much faster because activating the compressor instantly removes moisture. Normally, keeping the AC on when not using the defogging function just wastes fuel, as the engine has to work harder to power the compressor. My experience is that after the coolant warms up, turning off the AC and directly using the heater is the most efficient approach. I only activate the AC for defogging during rainy/snowy days or when the windshield frosts over.
