What are the manifestations of insufficient air conditioning refrigerant?

What are the manifestations of insufficient refrigerant?

1.The tracheal valve was dry, and there was no obvious cool feeling to the touch. 

The reason is that insufficient refrigerant causes the boiling end point in the evaporator to advance, so that the refrigerant superheat of the valve increases, and the temperature of the valve increases, which is greater than the dew point temperature of the outdoor air.

2.Frost on the liquid line valve. 

The reason is that insufficient refrigerant causes the pressure in the liquid pipe to drop and the boiling point to drop, making the valve temperature lower than the freezing point.

3.Open the indoor unit panel and remove the filter, you can find condensation or frost on part of the evaporator. 

The reason is that due to the lack of refrigerant, only part of the evaporator boils and absorbs heat, which reduces the cooling area accordingly;

4.There is no heat sensation in the exhaust air of the outdoor unit. 

The reason is that the condensation pressure and condensation temperature are reduced due to insufficient refrigerant, and the exhaust air temperature is also reduced.

5.Drain hose drains intermittently or does not drain at all. 

The reason is that the cooling area of the evaporator is reduced, the condensation area is also reduced, and the amount of condensed water is reduced.

6.There are oil stains on the gas and liquid valves of the outdoor unit, and if there is oil pollution, there will be leakage. 

The reason is that the refrigerant and refrigeration oil have a certain mutual solubility, fluorine escapes from the leak point and enters the atmosphere, and the oil adheres around the leak point.

7.The working current of the measured air conditioner is less than the rated current. 

The reason is that the compressor work load is reduced due to insufficient refrigerant, and the current is reduced.

The pressure measured from the fluorine filling port of the outdoor unit is lower than 0.45Mpa. The reason for this is a drop in evaporative pressure due to insufficient refrigerant.