Why does the car air conditioning pipe freeze but the car interior doesn't cool down?
1 Answers
Analysis of the reasons why the car air conditioning pipe freezes but the car interior doesn't cool down is as follows: 1. Freezing and blockage at the expansion valve: When the expansion valve freezes, it indicates the refrigerant contains moisture. Symptoms include intermittent cooling of the air conditioning. Moisture expands and freezes at the expansion valve, causing the evaporator to stop absorbing heat and rapidly increasing the temperature. Then the ice melts into water, and the evaporator resumes heat absorption and cooling, followed by freezing again, creating a cycle. 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 falling, so the temperature sensor closes, while the pressure switch only turns off the compressor clutch when high pressure reaches a certain value. If the high pressure doesn't reach the rated value and the ice melts, the pressure switch doesn't function. 2. Frost formation on the outer surface of the low-pressure pipe: This situation is common in cars with good cooling performance. It happens when the condenser performs exceptionally well or the evaporator performs exceptionally poorly, unrelated to pressure. Many car owners who have had their air conditioning repaired will notice that the air conditioning doesn't cool as well after driving home as it did right after repair. The reason is that most repair shops rinse the condenser with water after fixing the air conditioning, as water helps improve the condenser's heat dissipation, leading to frequent frost formation on the outer surface of the low-pressure pipe.
