What is the normal pressure value for a car's air conditioning

The normal pressure for a car's refrigeration system should be:

1. Static pressure: The high and low pressures are equal, both at 300~500 kPa.
2. Dynamic pressure: When the engine speed is 2500 r/min and the refrigeration compressor has been working for 5 minutes, the low-pressure side should be 130~180 kPa, and the high-pressure side should be 1100~1500 kPa.

If the pressures on the high and low sides of the refrigeration system are abnormal, it indicates a fault in the system. When the compressor is running at 1500~2000 rpm, the high pressure (discharge pressure) is normally around 1.5~2.0 MPa, and the low pressure (suction pressure) is around 0.15~0.35 MPa.

The specific values depend on the matching of different vehicle air conditioning systems and environmental temperature conditions. At idle speed (engine 700~900 rpm), if the ambient temperature is high, such as under direct sunlight in summer, the high pressure may be slightly higher, reaching up to around 2.5~2.8 MPa, but it generally does not exceed 3.1 MPa, otherwise the pressure switch will activate for protection.