There is a device under the center console of the air-conditioned heater car, which we will call "temperature regulating box" for the time being. One end of it is connected with the air conditioning filter element, and the other end is connected with the air outlet in the car. There are many things in the incubator, such as evaporation box, warm air box, mixing damper, fan and so on. Needless to say, the function of the fan is to blow the air and drive the airflow.
The evaporation box is connected with the compressor of the air conditioner, and the refrigerant compressed by the compressor evaporates and absorbs heat in the evaporation box to cool the air, which is the source of air conditioning cold air in summer. The warm air water tank is equivalent to a small radiator, which is connected to the engine cooling system and the coolant flows in it. Why doesn't the water temperature come up in winter and the warm air is not hot? That's because the coolant temperature is low.
The mixing damper is a kind of baffle, which can change the airflow path, mix hot and cold air and adjust the outlet temperature. The picture above shows the working principle of the mixing damper. The thing that opens and closes back and forth in the picture is the mixing damper. This is a touching film. I set the switching time of the picture to 10 second, which is convenient for everyone to look up the text.
The above picture is a structural diagram of a simulated temperature regulating box. After the fan drives the airflow into the temperature regulating box, the airflow first passes through the air conditioner evaporator and then through the warm air box. The red one represents the mixing damper. The mixing damper can be rotated to change the airflow path. For example, the above picture shows the state when the warm air is turned on, the air door is opened, and the air flow passes through the evaporator and then through the warm air box. If the engine water temperature is normal at this time, the air flow will be heated by the heater box and the hot air will be blown out of the car.
At this time, if you want to turn on the AC switch, the evaporator will produce low temperature. The original air intake was 10 degrees Celsius. As soon as you turned on the air conditioner, the temperature dropped to 5 degrees Celsius. At this time, the warm air tank will lose more heat to heat the air, and the outlet air temperature will inevitably decrease.
So if you turn on the warm air for heating, there is no need to turn on the AC switch. This not only wastes engine power, but also increases the heat loss of engine coolant.
When the air conditioner is turned on, the air conditioner switch is turned on, the compressor is started, and the evaporator produces low temperature. At this time, the mixing damper will block the warm air tank, so that the air flow will enter the thermostat and then cool down through the evaporator, and then bypass the warm air tank and directly enter the cockpit. If the mixing damper does not block the warm air tank, if the air flow is finally cooled and heated by the warm air tank, it is a waste.
Dehumidification mode This is what I call the old driver operation mode, dehumidification mode.
When the warm air is turned on, the AC switch of the air conditioner is also turned on, so that the air flow passes through the evaporator first, and the water vapor in the air flow condenses on the evaporator, and the humidity of the air flow decreases and becomes drier. Then the dry airflow is heated by the warm air tank and sent to the cockpit.
Why dehumidify? Mainly used for rapid defogging. Because the fog on the windshield is mainly due to the high humidity of the air inside the car, it is best to blow it with warm air at this time, but the premise is that the humidity of the airflow blown by warm air is small. If the humidity is too high, it is no different from breathing on the windshield, but it will aggravate the fog. At this time, the compressor is turned on, and the dehumidification characteristics of the air conditioner are used to dehumidify the airflow first, and then the dry airflow is heated and sent to the cockpit for defogging, and the effect is perfect.
Therefore, don't hesitate to turn on the warm air to demist, and turn on the AC switch immediately, which may have unexpected effects.
There is basically no need to operate the automatic air conditioner. Most cars will automatically turn on the AC switch for you after turning on the defogging mode. If your car won't start automatically, you can manually turn the air conditioner to the highest temperature and then turn on the AC button.
Manual air conditioning, just turn the thermostat knob to the red area to the end. In this way, the mixed air door in the thermostat will completely expose the heater box. At this time, the intake air is dehumidified by the evaporator and then heated by the warm air box to become dry and hot air, and the defogging effect will be greatly improved.