What Causes the Ice Blockage Phenomenon in Car Air Conditioning?

[LeJessica]

There are several main reasons for ice blockage in car air conditioning: 1. Pressure leak testing: During pressure leak testing, water vapor from the air is drawn into the pipes, causing ice blockage. 2. Evaporator: Atmospheric pressure introduces water molecules from humid air into the system, leading to ice blockage. 3. Air conditioning pipes: Unsealed pipes after the air conditioning system is opened can cause ice blockage. 4. Refrigerant: Too much moisture in the refrigerant can lead to ice blockage when charging. 5. Drier filter: Aging or failing drier filters lose their moisture-absorbing function, contributing to ice blockage. Below are several effective methods to prevent ice blockage. 1. Discharge refrigerant to remove water: For severely blocked systems, run the system. Before ice blockage occurs, make a shallow cut on the capillary tube connected to the drier filter and break it to quickly release the refrigerant under pressure. This allows a large amount of moisture to be expelled from the system. Then, through vacuuming and heating the pipe walls, moisture can be quickly removed. 2. Heating and draining method: After recovering or discharging the refrigerant, keep the system running to raise the compressor temperature. Place a pot of hot water in both the freezer and refrigerator compartments. Use a hair dryer to continuously heat the condenser. After some time, vacuum the process tube. Water boils and vaporizes at around 30 degrees under vacuum. This continuously removes water vapor from the system, achieving the goal of expelling moisture. Replacing the drier filter isn’t always necessary to prevent ice blockage. Simply heating it to remove moisture can reactivate the filter, making it reusable. Among all methods, the drier filter’s moisture removal process is a mandatory step after major repairs for any refrigeration system.