What Causes Normal High Pressure but High Low Pressure in Car Air Conditioning?

[Willa]

When the high pressure is normal but the low pressure is high in a car's air conditioning system, it typically indicates an abnormal or damaged expansion valve. Here are specific details about the air conditioning expansion valve: 1. Function: The expansion valve is a crucial component in the refrigeration system, usually installed between the liquid receiver and the evaporator. It converts medium-temperature, high-pressure liquid refrigerant into low-temperature, low-pressure wet steam through throttling. The refrigerant then absorbs heat in the evaporator to achieve cooling. The expansion valve controls the valve flow based on superheat changes at the evaporator outlet, preventing insufficient utilization of the evaporator surface area and compressor knocking. 2. Composition: The expansion valve consists of three main parts: the valve body, temperature sensing bulb, and equalizer tube.