Use and Differences of R410a, R134a, R407C, R22 Refrigerants

At present, the commonly used refrigerant types for air conditioners are R410a, R134a, R407C, and R22. Today we briefly analyze the usage and differences between them.

R134a is a single component refrigerant while R407C and R410a are mixed refrigerants.

R410a is a mixture of R32 and R125, and R407C is a mixture of R32, R125 and R134a.

The advantage of mixed refrigerants is that a refrigerant can be synthesized in proportion according to the specific requirements of use, taking into account various properties such as flammability, capacity, discharge temperature and efficiency.

R134a

The capacity of R134a is smaller than that of R22, and the pressure is lower than that of R22. Due to these features, an R134a air conditioner with the same capacity needs to be equipped with a compressor with a larger displacement, larger evaporator, condenser and piping. The end result is that the R134a system will cost more to manufacture and operate a system with the same cooling capacity as the R22.

The water absorption of R134a is very strong, which is 20 times that of R22, so the requirements for the dryer in the unit system are higher to avoid ice blockage.

The R134a system requires a special compressor and special grease lubricating oil. Due to its high water absorption, high foaming and high diffusivity, the grease lubricating oil is inferior to the mineral oil used in the R22 system in terms of system performance stability. .

R407C

The capacity and pressure of R407C refrigerant are relatively close to R22. Therefore, by adjusting the system design, the original R22 system can also be applied to the R407C system. Of course, the mineral refrigeration oil in the original system should be replaced with a lubricating oil (POE oil) that can be miscible with R407C.

However, the energy efficiency ratio of the R22 system will be reduced by about 5% compared with the original system. This is due to the temperature drift of R407C up to 6 degrees relative to other refrigerants. Therefore, the R407C system will reduce heat transfer when the same standard condenser and evaporator are used, which will affect the energy efficiency ratio of the system.

Since R407C is a mixed non-azeotropic working fluid, in order to ensure that its mixed composition does not change, R407C must be charged in a liquid state. If refrigerant leakage occurs in the R407C system and the performance of the system changes significantly, the remaining R407C in the system cannot be recycled and used, and the remaining R407C refrigerant in the system must be emptied and recharged with new R407C refrigerant.

R410a

For R410a, we published an article a few days ago, which detailed the differences with R22. There is a link at the end of the article, click to read. Here’s what I didn’t say before.

The capacity and pressure of R410a refrigerant are higher than that of R22, and the operating pressure is 50%-60% higher. The operating noise of the R410a is significantly lower than that of the R22 compressor by 2-4 decibels.

Compared to the R22 system, the R410a refrigerant system has a significant heat transfer advantage, with 35% higher heat transfer in the evaporator and 5% higher in the condenser. The system heat transfer coefficients of R134a and R407C are lower than that of R22.

The system redesigned for R410a refrigerant uses smaller volume evaporator and condenser, lower cost, and up to 30% refrigerant charge reduction. The reduction in refrigerant charge, in addition to cost reduction, improves overall system reliability

In the system with the same cooling capacity and the same condensing temperature, the system energy efficiency ratio (COP) of R410a refrigerant can be 6% higher than that of R22. This is due to lower losses in the compressor during compression, greater heat transfer between the evaporator and condenser, and less pressure drop across the system. Efficient heat transfer and smaller pressure drop enable lower condensing temperature and higher evaporating temperature under the same operating conditions, which enables the compressor to obtain a better performance with less power consumption and higher efficiency ratio. operating range.