The global demand for hot water (air source water heaters) has led to the development of an organizational structure and development pattern in China, with vacuum collection technology, heat pump technology, system refrigeration technology, system heating technology, intelligent control technology, and other eight core technology groups. In refrigeration systems, the evaporator, condenser, compressor, and throttle valve are the four essential components. Here are the methods to determine and analyze the reasons for insufficient refrigerant in the refrigeration system.

1. Insufficient refrigerant leads to a decrease in evaporator’s evaporation, resulting in reduced cooling capacity and poor refrigeration effect.
2. The thermal expansion valve does not frost or rarely frosts. In air conditioning conditions, there is no condensation or very little condensation.
3. Due to insufficient refrigerant, both the suction pressure and discharge pressure of the compressor are lower than normal values.
4. The evaporator rarely frosts or does not frost at all. In air conditioning conditions, there is no condensation or very little condensation.
5. Insufficient refrigerant often causes the compressor to operate below its rated load, resulting in low power consumption and even idling.

The reasons for insufficient refrigerant may include: improper refrigerant charging in newly installed systems, improper operation and maintenance leading to refrigerant leakage, poor system air tightness, and refrigerant leakage, among others.