What is the reason for the Mercedes-Benz R320 air conditioning not cooling?

[Ella]

Insufficient or low refrigerant level, possibly caused by minor refrigerant leakage. Below is an introduction to automotive air conditioning: 1. Automotive air conditioning overview: The automotive air conditioning system consists of a compressor, condenser, throttle element, evaporator, fan, and necessary control components, designed to regulate cabin temperature and humidity, providing a comfortable environment for drivers. 2. Working principle: When the compressor operates, it draws in low-temperature, low-pressure gaseous refrigerant from the evaporator. After compression, the refrigerant's temperature and pressure increase, and it is sent to the condenser. Inside the condenser, the high-temperature, high-pressure gaseous refrigerant transfers heat to the outside air passing through the condenser, causing it to liquefy into a liquid. When the liquid refrigerant flows through the throttle device, its temperature and pressure decrease, and it enters the evaporator. In the evaporator, the low-temperature, low-pressure liquid refrigerant absorbs heat from the cabin air passing through the evaporator and evaporates into gas. The gas is then drawn back into the compressor to begin the next cycle.