R407C Refrigerant - Starget

Things About R407C Refrigerant

R407C Refrigerant is a refrigerant composed of R32, R125, and R134a refrigerants mixed in specific proportions. It is an environmentally friendly refrigerant that does not harm the ozone layer.


R407C refrigerant is a long-term alternative to R22 due to its similar characteristics and performance. It is used in various air conditioning systems and non-centrifugal refrigeration systems.

R407C refrigerant can be used in systems initially designed for R22 without requiring a complete system redesign. Only a few components of the original system need to be replaced, and the mineral refrigerating oil inside the original design should be replaced with lubricating oil (POE oil) compatible with R407C refrigerant to facilitate direct charging of R407C refrigerant, making it an environmentally friendly replacement for the original equipment.

As R407C refrigerant is a non-azeotropic mixture, it must be charged in liquid form to ensure its composition remains unchanged. If a refrigerant leak occurs in an R407C refrigerant system, and there is a significant change in system performance, the remaining R407C inside the system cannot be recovered and recycled; it must be evacuated from the system, and new R407C refrigerant must be recharged.


R407C refrigerant has an Ozone Depletion Potential (ODP) value of zero but has a relatively high Global Warming Potential (GWP). Its boiling point is quite close to that of R22. At standard atmospheric pressure, its boiling range is -43.4 to -36.1°C, shifting from -36.1°C to -43.4°C. However, in air conditioning applications, its vapor pressure is about 10% higher than that of R22.

Under air conditioning conditions, R407C refrigerant has slightly lower volumetric cooling capacity and Coefficient of Performance (COP) than R22, with a 5% reduction in these values. In low-temperature conditions, COP doesn’t change significantly, but volumetric cooling capacity decreases by 20%.

R407C refrigerant has poor heat transfer performance, which directly impacts refrigerant changes. It does not mix with mineral lubricating oil but dissolves in polyester synthetic lubricating oil, making proper oil management essential.


R407C refrigerant is introduced as a ternary non-azeotropic refrigerant to replace R22. In actual replacements, only lubricating oil, dryer, and other minor components need to be changed. Additives are often used in the system to improve the tendency of ester oils to decompose. To fully utilize its advantages, it is best to use counterflow heat exchangers. Additionally, the condenser area and coolant flow are increased. R407C refrigerant is known for its cleanliness, low toxicity, non-flammability, and good refrigeration performance, making it widely used in the air conditioning industry.

R407C refrigerant is mainly used as a medium to high-temperature refrigerant in various applications, including residential air conditioning, small to medium-sized commercial air conditioning systems (such as small split air conditioners, ductless central air conditioning, and multi-split systems), mobile air conditioning (automotive air conditioning, etc.), dehumidifiers, freeze dryers, marine refrigeration equipment, and industrial refrigeration systems.


R407C refrigerant is the most straightforward choice for replacing the hydrofluorocarbon R22 in newly installed refrigeration equipment (typically air conditioning systems). However, due to differences in physical and chemical properties, theoretical cycle performance, and compressor oil compatibility between R407C refrigerant and R22, when it comes to after-sales maintenance of refrigeration equipment initially using R22 if additional refrigerant is required, it is usually only possible to add R22 directly rather than using R407C as a direct replacement (in other words, a bloodless replacement is generally not possible). However, for refrigeration equipment initially using R22, R417A can be used for direct replacement during maintenance or replacement.

Charging Methods for R407C Refrigerant

Typically, R407C refrigerant cylinders have two charging ports. One is the direct charging port, which has a tube that extends directly to the bottom but not to the bottom to prevent impurities at the bottom from entering the system during the upright filling of the refrigerant cylinder. The other is the short charging port, which extends a certain distance into the top of the refrigerant cylinder to prevent impurities from entering the system when filling the refrigerant cylinder upside down.

Horizontal Filling Method

When filling the R407C refrigerant horizontally, use the short charging port, not the direct one. R407 refrigerant enters the system directly from the quick charging port, and due to the effect of gravity, the horizontal filling process is faster. However, a certain amount of refrigerant remains uncharged in the cylinder. During this method of filling, the short charging port must be closest to the ground and not be positioned above the charging port.

Inclined Filling Method

When filling the refrigerant cylinder at an incline (30-45°C relative to the ground), use the short charging port. In this method, liquid R407C refrigerant enters the system directly from the fast charging port. If the direct charging port is used, the refrigerant is filled as a liquid when the refrigerant cylinder is full. When the refrigerant is below the internal tube of the direct charging port, gas is expelled. Because of the gravitational effect of the refrigerant, the inclined filling process is relatively fast, and most refrigerant inside the cylinder can be filled. Impurities in the cylinder will settle at the corner near the cylinder’s opening and will not enter the system. However, a certain amount of equipment is required for this method (recommended for use).

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