What Causes Ice Formation on Automotive High-Pressure Pipes?
3 Answers
Ice formation on automotive air conditioning high-pressure pipes may be caused by compressor malfunction, compressor leaks, or insufficient refrigerant. Below are relevant details: 1. Compressor pressure: Normally, automotive air conditioning compressors operate at 1500-2000 rpm, with high pressure around 1.5-2.0 MPa and low pressure around 0.15-0.35 MPa. If the low-pressure gauge drops rapidly during refueling while the high-pressure gauge also decreases quickly, this may indicate excessive expansion valve opening, requiring inspection, repair, or replacement. 2. Automotive air conditioning: Automotive air conditioning systems regulate and control cabin temperature, humidity, air cleanliness, and airflow to optimal levels, providing passengers with a comfortable environment that reduces travel fatigue. It also creates favorable working conditions for drivers, serving as a crucial ventilation device for safe driving.
Last time I was on a long drive, the air conditioning suddenly stopped cooling. When I got out to check, I found the high-pressure pipe was frozen. The mechanic later told me this usually happens due to insufficient refrigerant, causing the evaporator temperature to drop too low, allowing frost to spread to the high-pressure pipe. It could also be caused by moisture or air entering the system, leading to condensation and freezing when temperatures drop. This is especially common in winter or rainy weather. If this happens, don’t force the AC on—turn it off and switch to external circulation to dissipate heat, otherwise the compressor could overload and burn out. In my case, the issue was a loose pipe connection causing a leak, and replacing the sealing ring fixed it. It’s recommended to have the AC checked before summer every year to avoid unexpected breakdowns on the road. Driving safety comes first—address any issues as soon as they arise.
High-pressure pipe icing is mostly caused by refrigerant leakage or insufficient refrigerant. System imbalance can lead to excessive cooling and frosting at the evaporator, affecting the high-pressure pipe. Another common cause is a blocked or dirty expansion valve, which disrupts normal flow. When helping a friend troubleshoot, I used a pressure gauge and immediately noticed abnormally low pressure on the low-pressure side, indicating the issue. Cold external environments can also contribute, as poor condensation worsens icing. In such cases, turn off the AC immediately to inspect and prevent pipe bursts. Professional repairs are recommended, as they can clean or replace components. Regularly maintaining the cleanliness and sealing of the AC system helps reduce the risk of malfunctions.
