What Causes the Car Air Conditioner Evaporator to Freeze?
2 Answers
Here is a detailed introduction to the causes of car air conditioner evaporator freezing: 1. Expansion valve: The adjustment range of the expansion valve is too small, resulting in excessively low low-pressure. 2. Refrigerant: Insufficient refrigerant in the system leads to excessively low evaporation pressure. 3. Internal circulation: The internal circulation filter is clogged. 4. Temperature control failure: The temperature control (or temperature sensor) malfunctions, causing the compressor to run continuously. 5. Variable displacement compressor: The energy control valve (pressure regulating valve) of the variable displacement compressor fails, keeping the compressor operating at full capacity, resulting in excessively low low-pressure and evaporator freezing.
That day I found the air conditioning wasn't cooling when I was driving, so I took it to the repair shop and saw the evaporator was covered with a thick layer of ice! The mechanic said this situation often occurs because there's too much refrigerant or the expansion valve is stuck, causing the evaporator temperature to drop below freezing. Another possibility is that the cabin air filter is clogged, resulting in insufficient airflow to carry away the cold air, causing moisture to condense into ice. I remember replacing the expansion valve solved the problem at that time. If the icing persists, it will affect cooling performance and may even freeze and damage components inside the evaporator, so it needs to be addressed promptly.
