R-410A is a refrigerant used in air conditioning and heat pump applications. It is a zeotropic but near-azeotropic mixture of difluoromethane (CH2F2, called R-32) and pentafluoroethane (CHF2CF3, called R-125). R-410A is sold under the trademarked names AZ-20, EcoFluor R410, Forane 410A, Genetron R410A, Puron, and Suva 410A.

On December 27, 2020, the United States Congress passed the American Innovation and Manufacturing (AIM) Act, which directs US Environmental Protection Agency (EPA) to phase down production and consumption of hydrofluorocarbons (HFCs).[1][2] The AIM act was passed because HFCs have high global warming potential. Rules developed under the AIM Act require HFC production and consumption to be reduced by 85% from 2022 to 2036.[3] R-410A will be restricted by this Act because it contains the HFC R-125. Other refrigerants with lower global warming potential will replace R-410A in most applications, just as R-410A replaced the earlier ozone-depleting refrigerant, R-22.[4]

History

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R-410A was invented and patented by Allied Signal (now Honeywell) in 1991.[5] Other producers around the world have been licensed to manufacture and sell R-410A.[6] R-410A was successfully commercialized in the air conditioning segment by a combined effort of Carrier Corporation, Emerson Climate Technologies, Inc., Copeland Scroll Compressors (a division of Emerson Electric Company), and Allied Signal. Carrier Corporation was the first company to introduce an R-410A-based residential air conditioning unit into the market in 1996 and holds the trademark "Puron".[7]

Transition from R-22 to R-410A

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In accordance with terms and agreement reached in the Montreal Protocol (The Montreal Protocol on Substances That Deplete the Ozone Layer), the United States Environmental Protection Agency mandated that production or import of R-22 along with other hydrochlorofluorocarbons (HCFCs) be phased out in the United States. In the EU and the US, R-22 could not be used in the manufacture of new air conditioning or similar units after 1 January 2010.[8] In other parts of the world, the phase-out date varied from country to country.

Since 1 January 2020, the production and importation of R-22 has been banned in the US; the only available sources of R-22 include that which has been stockpiled or recovered from existing devices.[8]

 
R410a - zeotropic but near-azeotropic mixture of difluoromethane


By 2020, most newly manufactured window air conditioners and mini split air conditioners in the United States used refrigerant R-410A.[9] Further, R-410A had largely replaced R-22 as the preferred refrigerant for use in residential and commercial air conditioners in Japan and Europe, as well as the United States.[8]

Environmental effects

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Rapid growth of R-410A (HFC-125/HFC-32) atmospheric concentrations, when & IF leaked (bottom-right graph).

Unlike alkyl halide refrigerants that contain bromine or chlorine, R-410A (which contains only fluorine) does not contribute to ozone depletion and therefore became more widely used as ozone-depleting refrigerants like R-22 were phased out. However, like methane, R-410A has a global warming potential (GWP) that is appreciably worse than CO2 (GWP = 1) for the time it persists. R-410A is a mixture of 50% HFC-32 and 50% HFC-125. HFC-32 has a 4.9 year lifetime and a 100-year GWP of 675 and HFC-125 has a 29-year lifetime and a 100-year GWP of 3500.[10][11] The combination has an effective GWP of 2088, higher than that of R-22 (100-year GWP = 1810), and an atmospheric lifetime of nearly 30 years compared with the 12-year lifetime of R-22.[12][13]

Since R-410A allows for higher SEER ratings than an R-22 system by reducing power consumption, the overall impact on global warming of R-410A systems can, in some cases, be lower than that of R-22 systems due to reduced greenhouse gas emissions from power plants.[11] This assumes that the atmospheric leakage will be sufficiently managed.[14] Under the assumption that preventing ozone depletion is more important in the short term than GWP reduction, R-410A is preferable to R-22.[11]

R-410A Phaseout

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The phase-down mandated by the AIM Act will lead to R-410A's replacement by other refrigerants beginning in 2022. Alternative refrigerants are available, including hydrofluoroolefins, R-454B (a zeotropic blend of R-32 and R-1234yf), hydrocarbons (such as propane R-290 and isobutane R-600A), and even carbon dioxide (R-744, GWP = 1).[4][15][16][17] The alternative refrigerants have much lower global warming potential than R-410A. Some alternatives have mild or moderate flammability, operate in higher pressure ranges, or require specialized compressor lubricants and seals.

Physical properties

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R-410A is an A1 class non-flammable substance according to ISO 817 & ASHRAE 34. One of its components, R-32, is mildly flammable (AL2), and the other, R-125, is an A1 class substance that suppresses the flammability of R32.

Physical properties of R-410A refrigerant[18][19][20]
Property Value
Formula
CH2F2 (difluoromethane) (50%)
CHF2CF3 (pentafluoroethane) (50%)
Molecular weight (Da) 72.6
Melting point (°C) −155
Boiling point (°C) −48.5
Liquid density (30 °C), kg/m3 1040
Vapour density (30 °C), air=1.0 3.0
Vapour pressure at 21.1 °C (MPa) 1.383
Critical temperature (°C) 72.8
Critical pressure, MPa 4.90
Gas heat capacity (kJ/(kg·°C)) 0.84
Liquid heat capacity @ 1 atm, 30 °C, (kJ/(kg·°C)) 1.8
Flash point R-410A should not be mixed with air (oxygen) under pressure
Autoignition temperature Difluoromethane: 648 °C; pentafluoroethane is fire-retardant

Thermophysical properties - Properties of refrigerant R410a

Precautions

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R-410A cannot be used in R-22 service equipment because of higher operating pressures (approximately 40 to 70% higher). Parts designed specifically for R-410A must be used. R-410A systems thus require service personnel to use different tools, equipment, safety standards, and techniques to manage the higher pressure. Equipment manufacturers were aware of these differences and required the certification of professionals installing R-410A systems. In addition, the AC&R Safety Coalition was created to help educate professionals about R-410A systems.

R-410A cylinders were once colored rose, but they now bear a standard light gray color.[21][22]

While R-410A has negligible fractionation potential, it cannot be ignored when charging.

Trade names

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  • Suva 410A (DuPont)
  • Puron (Carrier)
  • Genetron AZ-20 (Honeywell)

See also

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References

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  1. ^ "Protecting Our Climate by Reducing Use of HFCs". US Environmental Protection Agency. 8 February 2021. Retrieved 25 August 2022.
  2. ^ "Background on HFCs and the AIM Act". www.usepa.gov. US EPA. Retrieved 27 June 2024.
  3. ^ EPA Press Office (23 September 2021). "U.S. Will Dramatically Cut Climate-Damaging Greenhouse Gases with New Program Aimed at Chemicals Used in Air Conditioning, Refrigeration". US Environmental Protection Agency. Retrieved 25 August 2022.
  4. ^ a b "Choosing a New System?". California Air Resources Board. Retrieved 25 August 2022.
  5. ^ "Home". www.honeywell.com. Archived from the original on November 16, 2007.
  6. ^ "Home". www.honeywell.com. Archived from the original on November 25, 2007.
  7. ^ "PURON - Reviews & Brand Information - Carrier Corporation SYRACUSE, NY - Serial Number: 77215886". Trademarkia.com. Retrieved 2016-05-01.
  8. ^ a b c "Phaseout of Class II Ozone-Depleting Substances". Retrieved 2024-06-26.
  9. ^ "Honeywell AZ-20 (R-410A) Refrigerant". Archived from the original on 2017-09-24. Retrieved 2021-09-01.
  10. ^ Velders, Guus J. M.; Fahey, David W.; Daniel, John S.; McFarland, Mack; Andersen, Stephen O. (July 7, 2009). "The large contribution of projected (if leakage is not controlled) HFC emissions to future climate forcing". Proceedings of the National Academy of Sciences. 106 (27): 10949–10954. Bibcode:2009PNAS..10610949V. doi:10.1073/pnas.0902817106. PMC 2700150. PMID 19549868.
  11. ^ a b c Pierrehumbert, R.T. (May 30, 2014). "Short-Lived Climate Pollution". Annual Review of Earth and Planetary Sciences. 42 (1): 341–379. Bibcode:2014AREPS..42..341P. doi:10.1146/annurev-earth-060313-054843.
  12. ^ "IPCC Assessment Report 4 (AR4) 2007" (PDF). p. 212. Retrieved 25 August 2022.
  13. ^ "High-GWP Refrigerants". California Air Resources Board. Retrieved 25 August 2022.
  14. ^ "The Essentials Of Working With R-410A" (PDF). Florida State College at Jacksonville. p. 7. Archived from the original (PDF) on September 4, 2014. Retrieved November 21, 2013.
  15. ^ "TRANSITIONING TO LOW-GWP ALTERNATIVES in Residential and Commercial Air Conditioning and Chillers" (PDF). US Environmental Protection Agency. December 2016. Retrieved 25 August 2022.
  16. ^ Johnston, Philip (2020-10-13). "What's Next: Specifying the Right R-410A Replacement". Engineered Systems Magazine.
  17. ^ "Carrier Introduces Puron Advance™: The Next Generation Refrigerant for Ducted Residential, Light Commercial Products in North America". Carrier Commercial Systems North America. Retrieved 26 June 2024.
  18. ^ "R-410a Material Safety Data Sheet" (PDF). Honeywell International Inc. Archived from the original (PDF) on 2010-10-11. Retrieved 2009-07-03.
  19. ^ "Puron Refrigerant R-410A" (PDF). Archived from the original on 21 December 2006. Retrieved 2 July 2014.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  20. ^ "R-410A" (PDF). Honeywell Refrigerants Europe. Archived from the original (PDF) on 27 March 2014. Retrieved 26 April 2013.
  21. ^ "Refrigerants - Color Codes". www.engineeringtoolbox.com.
  22. ^ "Refrigerant Color Codes". 24 May 2023.