What is the correct way to use a car air conditioner?

[LeReid]

The correct way to use a car air conditioner is: 1. Cooling mode: After starting the car, turn the knob to the cooling direction and press the AC button and the blower switch; 2. Heating mode: Turn the knob to the heating direction and turn on the fan switch to get warm air. The method to turn off the car air conditioner is to adjust the fan speed switch to the 0 position. The functions of a car air conditioner are: 1. To adjust and control the temperature, humidity, air cleanliness, and air flow inside the cabin to an optimal state; 2. To provide a comfortable riding environment for passengers and reduce travel fatigue; 3. To create good working conditions for the driver and ensure safe driving.

[Maverick]

I frequently drive long distances and pay attention to both efficiency and fuel economy when using the air conditioning. After the car has been exposed to the sun, don’t rush to turn on the AC. First, roll down the windows for ventilation for a minute or two to let the hot air escape before closing the windows and cooling. When starting the car, use the external circulation mode to speed up air exchange, then switch to internal circulation once the temperature drops to maintain warmth and save fuel. In winter, don’t immediately turn on the heater—let the engine run for two minutes first to allow the coolant temperature to rise, then use the natural warm air for comfort and efficiency. Two to three minutes before reaching your destination, turn off the AC but keep the fan running to dry out the AC ducts, effectively preventing bacterial growth and odors. On highways, alternate between internal and external circulation—keeping it on internal for too long can lead to oxygen deprivation and drowsiness. I replace the AC filter every six months; this is an expense that shouldn’t be skipped.

[KathrynDella]

For daily commuters, air conditioning usage directly impacts ride comfort. In summer, after starting the car, first open the windows for 30 seconds to vent hot air before turning on the AC at maximum fan speed for immediate cooling. Setting the temperature between 23-25°C is ideal to avoid catching cold from drastic indoor-outdoor temperature differences. Switch to recirculation mode in heavy traffic to protect air quality from exhaust fumes, while using fresh air mode on highways ensures proper ventilation. For foggy windshields on rainy days, activate the defogger mode with AC dehumidification for best results. Clean AC vents monthly to prevent dust buildup. In winter, utilize engine waste heat for warmth without engaging the AC compressor—fuel-efficient and effective.

[LaAlexa]

After having children, I pay special attention to in-car health issues. Before traveling with kids, I always check the AC: start the car, turn on the AC to smell for odors, and replace the filter immediately if any strange smell is detected. Avoid direct cold airflow toward the child seat area. Set the temperature to 24°C with medium fan speed to prevent excessive temperature differences that could make the child catch a cold. In summer, open windows for ventilation before turning on the AC to avoid inhaling volatile formaldehyde. During long trips, take a break every two hours to open windows for ventilation and reduce CO₂ concentration. Regularly clean drainage holes during rainy seasons to prevent mold growth. If the AC cooling weakens, first check if the condenser is clogged with willow catkins—just rinse it with a water gun. Develop the habit of turning off the AC before shutting down the engine to protect the compressor's lifespan.