How to Determine Whether the Refrigerant Charge is Appropriate?

How to Determine Whether the Refrigerant Charge is Appropriate?


The operation of the refrigeration system depends on whether the charged refrigerant is appropriate. We must ensure that the refrigerant charge is appropriate when charging. This article will specifically introduce the method to determine the refrigerant charge.

How to Determine Whether the Refrigerant Charge is Appropriate?

The operation of the refrigeration system depends on whether the charged refrigerant is appropriate. Insufficient refrigerant charging in the system will result in insufficient evaporation of the evaporator, resulting in low suction pressure of the compressor, reduced cold capacity, and possible overheating of the compressor. Excessive addition of liquid will cause too much refrigerant to enter the condenser, resulting in excessive discharge pressure, liquid refrigerant backflow, and possibly even damage to the compressor. Most systems have a reasonable allowable limit for the amount of liquid to be added, but some small systems have extremely strict filling amounts, which is extremely important for its normal operation. The following is the method to determine the refrigerant charge.

Weighing method

The most accurate charging method is to actually weigh the refrigerant added to the system. This method can only be used when the required charge volume of the system is known and the system requires a full charge. Generally, the integral equipment meets the above conditions. If the charge volume is small and the refrigerant system needs to be repaired, The common practice is to let off the refrigerant in the system and add up to the required amount of the system after the repair is completed.

Sight glass method

The most common way to determine whether the system’s refrigerant charge is appropriate is to use a sight glass in the liquid pipe. Because the pressure of the liquid refrigerant is very important to the control of the expansion valve. When the transparent liquid refrigerant flow is seen from the sight glass, it can be considered that the system is properly charged.

If you see bubbles or flashes, it usually means that the refrigerant is not enough. Remember, if there is no liquid but steam, it will be transparent when seen in the sight glass. However, maintenance engineers should be aware of the fact that when the system is charged correctly, bubbles or flashes can also be seen in the sight glass. This is because the resistance in the liquid pipe in front of the sight glass causes a pressure drop, causing the refrigerant to flash.

Level gauge method

In some refrigerant systems, the reservoir is equipped with a liquid level test port. If the charge volume has been reached, open the test port slightly, and liquid refrigerant will appear in the test port. If only refrigerant vapor appears at the test port, the charge volume is not enough. Larger liquid storage tanks may be equipped with a float indicator to indicate the liquid level in the liquid tank, which is very similar to the structure of the gasoline tank used in automobiles.

When we operate the refrigerant filling step, we try our best to let professional staff do the operation, otherwise improper operation will cause a safety accident. If you want to learn more about refrigerants after reading the above content, you can contact us to obtain related solutions, and we will provide you with professional consultation.

As a professional refrigerant manufacturer, we have many years of history in manufacturing. We strictly follow the standard production and carry out comprehensive quality control, and can provide customers with safe and high-quality products. Our thoughtful one-stop service can provide customers with good solutions. We are always committed to providing customers with the most innovative and most available technology and product services. If you are interested in our refrigerant products, please contact us immediately!