Why does the air conditioning compressor freeze?

[LeEsther]

Reasons for air conditioning compressor freezing: 1. Excessive refrigerant charge often leads to excessively high condensation pressure in the refrigeration system, resulting in an excessive pressure difference between high and low pressures. This causes the liquid supply from the throttling component to exceed the heat exchange capacity of the evaporator, leading to liquid refrigerant returning to the compressor; 2. Improper design or adjustment of the throttling component, causing excessive refrigerant to return to the compressor and resulting in compressor freezing; 3. Blockage in the refrigeration system's return pipe leads to excessively high evaporation pressure, reducing the heat exchange capacity of the evaporator. This causes liquid refrigerant to return to the compressor, forming ice.

[DiMackenzie]

I found that air conditioning compressor icing is usually caused by issues within the system. When refrigerant is insufficient, the system pressure drops, causing the evaporator temperature to plummet and moisture to condense into ice. The compressor will be overloaded under such conditions, resulting in frost formation on the exterior. Another common cause is a faulty expansion valve or throttling device, which fails to regulate refrigerant flow, leading to temperature loss of control. Additionally, pipe blockage or moisture in the system can cause freezing blockage, which leads to compressor frosting. High environmental humidity can also trigger this situation. From my experience, timely inspection of refrigerant levels and system sealing can prevent icing.

[Arthur]

I've encountered compressor icing quite often during car repairs. There are three main reasons: insufficient refrigerant lowers pressure, causing the evaporator to freeze and the compressor to malfunction; a non-functioning fan or poor air circulation allows cold air to accumulate, leading to icing; moisture or contaminants in the system causing freeze blockage is the root cause. It's advisable not to wait until icing occurs to address the issue—regularly check pipeline and valve seals. Additionally, during hot weather, avoid running the AC continuously for extended periods; give the system a break.

[Calvin]

Having driven for over 20 years, I've seen compressor icing mostly caused by refrigerant leaks or fan failures. Low refrigerant makes the evaporator cool too quickly and freeze; a faulty fan prevents cold air from escaping and backfeeds the compressor. Moisture intrusion into the system can also cause freeze-ups and frost buildup. Remember, if you notice reduced airflow from the AC, stop immediately to let the system thaw before troubleshooting. Regular maintenance can prevent these issues.