Our conventional refrigeration units generally use R22 refrigerant. As the use of R410A refrigerant becomes more widespread, it is not reasonable to directly replace R22 in the system with R410A. There are differences in the physical parameters of the two refrigerants that need to be considered in system design.

Differences between R22 and R410A refrigerants:

1. 1. R410A refrigerant requires the use of synthetic refrigeration oil (POE). Due to the high moisture absorption and hydrolysis tendency of POE oil, the R410A system has stricter requirements for moisture content.
   2. In terms of charging amount, after reducing the size of the heat exchanger structure, the R410A system requires about 20% to 30% less refrigerant compared to the R22 system. R410A has higher overall heat transfer characteristics and efficiency, allowing for smaller heat exchangers.
   3. R410A is a refrigerant mixture composed of HFC-32 (R32) and HFC-125. It has higher requirements for copper pipes compared to R22, which can use standard copper pipes. The operating pressure of R410A is 50% to 70% higher than that of R22, about 1.6 times higher.
   4. R410A is classified as low toxicity, non-flammable, and does not contribute to ozone depletion, while R22 has a lethal impact on the ozone layer. R410A has better cooling capacity, with a cooling capacity of approximately 147% compared to R22’s 100%.
   5. Although R410A does not deplete the ozone layer, the greenhouse gas emissions it produces actually exceed those of R22. Therefore, R410A is not the ultimate environmentally friendly refrigerant solution for the air conditioning industry.
   6. R410A has a higher vapor density than R22, resulting in approximately 30% slower vapor flow velocity compared to R22. R410A also exhibits better solubility. Residues can circulate smoothly within the system when floating in R410A.

Other considerations:

1. R410A requires the use of high-strength, pressure-resistant copper pipes and dedicated components. R410A copper pipes can be used instead of standard R22 copper pipes, but never use standard R22 copper pipes as a substitute for R410A copper pipes.
2. During installation, R410A new refrigerant must not be mixed with the connecting pipes and refrigerant used for R22 air conditioners.
3. The installation of R410A air conditioning systems requires high precision. Avoid dropping sweat into the connecting pipes or introducing other insoluble impurities into the system. It is recommended to evacuate the system to prevent mixed contamination of refrigerant.
4. During maintenance, if the refrigeration system is cut open, the dryer filter must be replaced, and the exposed refrigeration system should not be left in the air for more than five minutes.
5. R410A refrigerant should be stored in an environment below 30°C. If it has been stored in an environment above 30°C, it must be stored in an environment below 30°C for at least 24 hours before use.
6. R410A systems have specific cleanliness requirements for four-way valves, while R22 systems do not have cleanliness requirements for four-way valves.
7. The design maximum working pressure of the stop valve is different: 3.0 MPa for R22 systems with brass fittings and 4.3 MPa for R410A systems with stainless steel fittings.
8. The pressure switch values are different: R22 systems typically choose 3.0/2.4 MPa, while R410A systems typically choose 4.2/3.6 MPa.
9. Under rated voltage, the compressor capacity per displacement (1 cc) is approximately 175W for R22 systems, while for R410A systems, it is approximately 245W, which is about 65% to 70% of the capacity of R22 systems.
10. Outdoor units of refrigeration systems should be labeled with the appropriate refrigerant type. The refrigerant specified on the label should be used, and R22 should not be directly replaced with R410A.