What does the AC button on the air conditioner mean?

[AmirMarie]

The AC button is the switch for the compressor. When turned on, the air conditioner starts adjusting the temperature according to the set value, while turning it off only activates the air blower. When the driver switches to the blue cooling mode, the compressor starts compressing and delivering refrigerant vapor. When switched to the red heating mode, warm air is delivered with the AC button turned off. Air conditioners can be categorized by performance into: Single-function type (where the cooling, heating, and ventilation systems are installed separately and operate independently without interference, commonly used in large buses and trucks) and integrated heating-cooling type (where cooling, heating, and ventilation share the same blower and air ducts, controlled via the same panel. During operation, they can be divided into combined type, where cooling and heating work separately, and mixed temperature-adjusting type, where cooling and heating can work simultaneously. Passenger cars mostly use the mixed temperature-adjusting type). Different types of air conditioning systems have different layout methods. Currently, passenger cars widely adopt the integrated heating-cooling air conditioning system. Its layout involves assembling the evaporator, heater core, centrifugal blower, and control mechanism together, known as the air conditioner assembly. Maintenance methods for car air conditioners include: Checking whether the air conditioning system components are in good condition before use; Regularly cleaning and replacing the air filter and cleaning the condenser. The car air conditioner consists of a compressor, condenser, throttle element, evaporator, fan, and control components, and is used to regulate the temperature and humidity inside the cabin, providing a comfortable environment for the driver and passengers. Precautions for using car air conditioners: In A/C mode, since the car air conditioner compressor is always in operation, it will inevitably increase fuel consumption and engine load, so it should be turned on selectively. In winter, do not use the air conditioner for extended periods because the warm air is generated by the engine's heat, and prolonged use can cause a stuffy feeling. Therefore, when using the air conditioner in winter, it's essential to open the windows periodically to allow air circulation and purification inside the car. In winter, the air in southern regions is humid and cold, and turning on the heater can easily cause fogging on the car windows. Many drivers are accustomed to turning on the defogging function, in which case the AC button should also be activated. When the AC button is used together with the external circulation mode, the defogging effect will be excellent. After running the air conditioner for some time, observe the engine coolant temperature. If the temperature is high, it may be due to a dirty condenser surface, non-functioning electric fan, or pressure controller failure. If this occurs, promptly stop the air conditioning system and take the vehicle to a service station for repair.