What does the BMW AC button mean?

[Louise]

The BMW AC button refers to the air conditioning cooling switch in the car. When the AC button is turned on, the air conditioning can provide cooling. The illuminated AC light indicates that the car's air conditioning compressor is running, and the air conditioning is cooling. If the AC light is off, it means the compressor is not working, and the air conditioning cooling function is turned off. The following are the functions of car air conditioning: 1. Temperature regulation: This is the main function of car air conditioning. In summer, the cooling system produces cold air to lower the temperature inside the cabin. In winter, except for large commercial vehicles that use independent combustion heaters for heating, other vehicles generally use residual heat from the car for heating. 2. Humidity regulation: Humidity greatly affects the comfort of passengers inside the car. The humidity inside the cabin should generally be maintained between 30% and 70%. Ordinary car air conditioning systems do not have the function to adjust cabin humidity; this can only be achieved by using ventilation systems or advanced luxury car air conditioning systems that integrate heating and cooling. 3. Airflow regulation: The speed and direction of airflow significantly affect passenger comfort. If the airflow is blowing directly, the speed should be limited to a certain range when the temperature is suitable. The airflow speed can be adjusted appropriately based on passengers' living environment, age, health condition, and temperature preferences. 4. Air purification: The quality of air inside the cabin is an important factor in ensuring comfort.

[DiCody]

From my 5 years of driving a BMW, the AC button is absolutely crucial. It mainly controls the activation of the air conditioning compressor. Without turning on the AC in summer, the cooling just doesn't work. The most amazing thing is during rainy days when the windshield fogs up—turning on the AC clears the fog super fast, making the glass crystal clear in no time. If you want to save fuel, just turn off the AC button, and the dashboard will show an ECO prompt. Even in winter, turning off the AC while using the heater can save some fuel. Nowadays, newer models even adjust the compressor frequency automatically based on the temperature difference inside and outside, making them much smarter than the older versions.

[McSienna]

Last time my bestie rode in my car, she asked what the snowflake button was for. It's actually the air conditioning cooling switch—you have to press it to turn on the cold air. Foggy windshields on rainy days are the most annoying, but the AC works ten times better than a cloth, clearing the fog in just two or three minutes. Recently, I found that turning off the AC at red lights saves fuel, but don’t turn off the recirculation mode or the fog will come back immediately. BMW’s automatic air conditioning even pairs with the MAX button for quick defrosting, so you don’t have to adjust the fan speed manually.

[AriannaMarie]

It's essentially a cooling switch. When turned on, the compressor starts cooling, and the evaporator temperature drops to around zero degrees, blowing out cold and dry air. On rainy days when the windshield fogs up, the cold air can quickly absorb moisture. Remember to turn on the AC along with the external circulation, otherwise the defogging effect will be reduced. Not using it for a long time can easily cause the compressor to seize, so it's recommended to run the air conditioner for ten minutes each month.