What Causes the Car Air Conditioning Pipe to Freeze and the Interior Not to Cool?
2 Answers
The reasons for the car air conditioning pipe freezing and the interior not cooling are analyzed as follows: 1. Freezing and blockage at the expansion valve: When the expansion valve freezes, it indicates that the refrigerant contains moisture. The moisture expands and freezes at the expansion valve, causing the evaporator to stop absorbing heat and the cooling temperature to rise rapidly. The ice then melts into water, and the evaporator resumes absorbing heat and cooling, leading to a cycle of freezing. This freezing occurs due to water or other frozen substances in the refrigerant, not because the temperature is too low. After freezing, the evaporator temperature rises instead of decreasing, so the temperature sensor does not function. The pressure switch only turns off the compressor clutch when the high pressure reaches a certain value. If the high pressure does not reach the rated value and the ice melts, the pressure switch does not function. 2. Frost formation on the outer surface of the low-pressure pipe: This situation commonly occurs in cars with good cooling performance. It happens when the condenser performs exceptionally well or the evaporator performs exceptionally poorly, unrelated to pressure. The reason is that after repairing the air conditioning, most repair shops rinse the condenser with water because water helps improve the condenser's heat dissipation. As a result, frost formation on the outer surface of the low-pressure pipe frequently occurs.
I've driven for several years and encountered the issue of frozen AC pipes and insufficient cooling inside the car multiple times, mainly due to problems with the AC system. The most common cause is insufficient refrigerant. When some refrigerant leaks out, the pressure in the system drops, causing the evaporator temperature to fall below freezing, which leads to moisture freezing and blocking the pipes, preventing cold air from circulating. Additionally, if the AC filter is too dirty and clogged, it can reduce airflow, making the evaporator more prone to freezing. I recommend first checking the AC filter to see if it needs replacement. If the problem persists, it might be a refrigerant leak, and you should visit a professional repair shop to refill and check the system's sealing. Sometimes, a slow fan speed can also cause similar issues, as it affects cooling efficiency. In short, if your car's AC isn't cooling properly and is freezing up, it indicates a serious problem. Don't attempt to fix it yourself to avoid damaging parts or compromising driving safety. It's best to find a reliable auto shop to address the issue promptly.
