As we all know, the frost direction is divided direction, there are mainly the following two kinds: from the compressor back to the air inlet began gradually to the evaporator direction frosting.

From the expansion valve to the evaporator direction frosting. Analysis of the two different frosting, the cause is the opposite, so friends in the elimination of problems, "can not only see expansion valve, evaporator, back to the trachea frosting, but also must distinguish the direction of frosting."

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Thermal expansion Valve

First, back to the beginning of frosting

Back to the beginning of frosting, mainly from the following two aspects to analyze:

1. Refrigerant

The reason is to enter the evaporator more refrigerant, resulting in evaporation is not complete, so in the back of the trachea is still evaporating, absorbing the heat of the suction tube, so back to the trachea first frosting.

The causes are:

1, too much refrigerant;

2, expansion valve open through large;

Electronic expansion Valve

2. Evaporator aspect

Evaporator can not absorb the normal heat, or the evaporator produced by the cold can not be taken away, will cause evaporation is not complete, refrigerant in the back of the trachea continue to evaporate endothermic, resulting in the back of the trachea frosting.

Appearance for the return liquid temperature and pressure normal or slightly low, from the compressor back to the air inlet began gradually to the evaporator direction frosting, long after the compressor back to the evaporator and throttle valve to the evaporator section of all ice, and finally appear low pressure.

The causes are:

1, to see whether the air filtration network clean;

2, look at the speed of the fan is normal;

3, the evaporator is clean;

4, the Air supply system is not blocked;

5, the belt is too loose.

Thermal expansion Valve

Second, expansion valve start frosting

Expansion valve behind frosting, mainly from the following three points analysis:

1, less refrigerant (leakage)

The condenser returns the liquid temperature to be high but the pressure is not high, starts from the throttle valve place gradually to the evaporator direction frosting.

2, expansion valve open to spend small

Condenser return liquid temperature and pressure normal or slightly lower, from the throttle valve began gradually to the evaporator direction frosting.

3, to check the visual fluid mirror Look at the refrigerant situation, the bubble is serious, may be the system leakage, the liquid mirror refrigerant bubble or very little bubble, may be opened too small expansion valve, or plug, generally in the plug before and after a large temperature difference.