6 Common R22 Refrigerant Replacements
R22 refrigerant, also known as chlorodifluoromethane, dichlorodifluoromethane, Freon-22, and abbreviated as HCFC-22, with the chemical formula CHClF2, is a hydrogen-containing fluorochlorocarbon. It is a colorless gas with a slightly sweet odor. R22 refrigerant is primarily used as a raw material for producing tetrafluoroethylene, as well as a refrigerant, propellant, and pesticide precursor.
However, dichlorodifluoromethane contributes to ozone depletion potential (ODP) and has a greenhouse effect (GWP). According to the Montreal Protocol, its use and production have been phased out in developed countries and can continue in developing countries until 2030.
So, what are the refrigerants in the market that can replace R22 Refrigerant?
1. R410A To Replace R22 Refrigerant
R410A is a near-azeotropic refrigerant composed of 50% R32 and 50% R125, with ODP = 0. It is mainly used as a substitute for R22 refrigerant. It has a higher cooling capacity per unit volume and good heat transfer and flow properties, but its pressure values are about 60% higher than R22 at the same temperature. When used safely, R410A is a non-flammable mixture with low toxicity of HFC-32 and HFC-125 (50/50 wt%). R410A is recognized by ASHRAE and designated as R-410A.
R-410A refrigerant offers higher cooling capacity and significantly higher pressures than R-22, designed specifically for systems that use R-410A. This hydrofluorocarbon (HFC) refrigerant is compatible with polyol ester (POE) oil and can replace R-22 in residential and light commercial air conditioning (AC) and heat pump systems.
2. R404A Refrigerant
R404A is a common industrial standard refrigerant that replaces R22 refrigerant and R502 in new refrigeration equipment, particularly in low-temperature freezing systems. It operates similarly to R-502 and is recognized and used by most refrigeration equipment manufacturers.
However, due to physical properties, theoretical cycle performance, and compressor oil differences between R404A, R502, and R22, it’s often not directly replaceable in equipment initially designed for R502 or R22 refrigerants.
3. R407C Refrigerant
R407C has entered the application phase, but like R410A, it has a high global warming potential (GWP) and is not a true “green” refrigerant. Its GWP value is similar to R22 refrigerant, and its thermodynamic properties and working pressure range are close to R22. It’s a non-flammable refrigerant. Adapting R22 systems to use R407C requires changing the compressor’s lubricating oil to ester oil.
4. R134a Refrigerant
R134a has an ODP of 0 and a GWP of 420. It’s non-flammable, non-toxic, and odorless, making it a potential replacement for R22 in terms of ozone protection. However, it’s pressures and cooling capacity are lower than R22’s, often necessitating modifications to systems when switching to R134a.
5. R32 Refrigerant
R32 is a mature, stable refrigerant with good heat transfer properties and a higher cooling capacity per unit volume. It’s considered a promising replacement for R22 refrigerant, with negligible impact on the ozone layer.
6. R290 Refrigerant
R290 propane refrigerant has properties similar to R22 refrigerant and is environmentally friendly. While explosive, it’s non-toxic and suitable for small air conditioners and medium-sized refrigeration equipment.
National macroeconomic factors, ozone layer depletion, and climate change influence the refrigeration industry’s development. Many of the alternatives on the market are transitional. Finding environmentally friendly replacements for R22 refrigerant remains a crucial challenge. The suitability of R410A, R290, and R32 as replacements for R22 refrigerant awaits validation in the market.
