What is the reason for car air conditioning refrigerant leakage that cannot be detected?

[Jaden]

You can check places like the condenser. Below is the relevant introduction about car air conditioning: 1. Air conditioning layout: Different types of air conditioning systems have different layout methods. Currently, cars widely use integrated heating and cooling air conditioning systems. The layout form involves assembling the evaporator, heater radiator, centrifugal blower, and control mechanism together, referred to as the air conditioning unit assembly. 2. Air conditioning composition: Modern air conditioning systems consist of refrigeration systems, heating systems, ventilation and air purification devices, and control systems. Car air conditioning generally mainly includes a compressor, electronically controlled clutch, condenser, evaporator, expansion valve, receiver-drier, pipelines, condenser fan, vacuum solenoid valve, idle speed controller, and control system. Car air conditioning is divided into high-pressure pipelines and low-pressure pipelines. The high-pressure side includes the compressor output side, high-pressure pipelines, condenser, receiver-drier, and liquid pipelines; the low-pressure side includes the evaporator, accumulator, return pipelines, compressor input side, and compressor oil sump.