Why does the low-pressure pipe of the air conditioner frost?

1. Insufficient refrigerant: After a split air conditioner has been used for a long time, refrigerant leakage or seepage will occur. When the refrigerant in the refrigeration system is reduced, the evaporation pressure will be too low, causing the evaporator to freeze. The location of the ice is generally in the front part of the evaporator. The troubleshooting method is to first deal with the leaking part and add enough refrigerant, and the fault will be eliminated.
2. Compressor failure: Similarly, after the air conditioner has been used for a long time, the compression efficiency of the compressor is reduced, or the compressor gas distribution system is damaged, causing the pressure to be too low and ice. The ice position is also in the front part of the evaporator. The former can add some refrigerant to eliminate the fault. If the fault persists, the compressor must be replaced.
3. Too much refrigerant: Insufficient refrigerant can cause the air conditioner to freeze, so too much refrigerant in the air conditioner will also cause the air conditioner to freeze. Some air conditioners are re-injected with refrigerant due to displacement, leakage, etc. The maintenance personnel improperly added too much refrigerant, causing too much refrigerant to flow to the rear part of the evaporator and evaporate and freeze. This type of ice is mostly formed in the rear part of the evaporator and around the compressor return pipe. Release the excess refrigerant and the fault will be eliminated.
4. The evaporator is too dirty: After the air conditioner has been used for a period of time, dust in the air or microorganisms produced by the evaporator will accumulate on the evaporator, hindering air circulation, causing heat exchange to decrease, and the evaporator temperature to be too low and iced. The ice is located at the rear part of the evaporator. After the ice melts, flush the evaporator with water and brush along the fins with a soft brush. Be careful not to wet the electrical parts. After cleaning, the fault is eliminated.

If the air conditioner freezes due to thermostat failure, then the thermostat of the air conditioner needs to be replaced; if it is found that the evaporator of the air conditioner is too dirty, then the evaporator of the air conditioner needs to be thoroughly cleaned. If the refrigerant is insufficient or too much, then it is necessary to eliminate or add refrigerant; if it is a compressor failure, it is best to replace the compressor of the air conditioner.