Can R134a be Used Instead of R22 Refrigerant?

The pressure design and pressure-enthalpy parameters of R134a and R22 refrigerants are very different, and modification is very difficult, so R22 refrigerants cannot replace R134a.

1. The global warming potential (GWP) of R134a is 0.25, and that of R22 is 0.36, both of which are greenhouse gases.

2. The ozone depletion potential (ODP) of R134a is 0, and that of R22 is 0.06. This is the reason why R134a becomes an environmentally friendly refrigerant.

3. The specific volume of R134a is 1.47 times that of R22, and the latent heat of evaporation is small, so the refrigeration capacity of R134a unit is only 60% of that of R22 unit. Calculated by unit cooling capacity price, the price of R22 unit is about 60% of that of R134a unit.

4. The thermal conductivity of R134a is 10% lower than that of R22, so the heat exchange area of the heat exchanger of the R134a unit needs to be larger.

5. 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.

6. Compared with R22, R134a has a stronger swelling effect on rubber substances, and the refrigerant leakage rate is higher in actual operation. In addition, it is highly corrosive to copper, and “copper plating phenomenon” will occur during use, so additives must be added to the system.

7. The R134a system requires a dedicated compressor and a dedicated grease lubricant. Grease lubricating oil is inferior to the mineral oil used in the R22 system in terms of system performance stability due to its high water absorption, high foaming property and high diffusivity.

8. The price of HFCs refrigerants such as R134a and its special lipid oil is higher than that of R22, and the operation and maintenance costs of equipment are higher.

Other refrigerants of the HFCs class known as environmentally friendly refrigerants, such as R410A, R440A, and R407C, are superior to R134a in terms of efficiency, but they also have too high working pressure, high requirements for the optimization of pipeline components and pressure resistance, and must be improved. Heat exchanger and unit design, investment, operation and maintenance costs are high.

In summary, ideal refrigerants do not exist in the short term. At the present stage in our country, R22 refrigerant still has the advantages of high efficiency, stability and low price compared with R134a environmentally friendly refrigerants, and it will also be in an advantageous position in the application of large-scale refrigeration units. Before the ideal refrigerant is born, R22 refrigerant can still be used until 2040.