R-410A, sold under the trademarked names Forane 410A, Puron, EcoFluor R410, Genetron R410A, and AZ-20, is a zeotropic, but near-azeotropic mixture of difluoromethane (CH2F2, called R-32) and pentafluoroethane (CHF2CF3, called R-125), which is used as a refrigerant in air conditioning applications.
Environmental effects 
Unlike alkyl halide refrigerants that contain bromine or chlorine, R-410A (which contains only fluorine) does not contribute to ozone depletion, and is therefore becoming more widely used, as ozone-depleting refrigerants like R-22 are phased out. However, it has a high global warming potential (1725 times the effect of carbon dioxide), similar to that of R-22.
R-410A was invented and patented by Allied Signal (now Honeywell) in 1991.  Other producers around the world have been licensed to manufacture and sell R-410A, but Honeywell continues to be the leader in capacity and sales. 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 a R-410A based residential air conditioning unit onto the marketplace in 1996 and holds the trademark "Puron".
R-410A has replaced R-22 as the preferred refrigerant for use in residential and commercial air conditioners in Japan, Europe and the United States.
Parts designed specifically for R-410A must be used as R-410A operates at higher pressures than other refrigerants. Thus R-410A systems require service personnel to use different tools, equipment, safety standards and techniques. Equipment manufacturers are aware of these changes and require the certification of professionals installing R-410A systems. In addition the AC&R Safety Coalition has been created to help educate professionals about R-410-A system.
R-22 Phaseout 
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 has 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 USA, virgin R22 cannot be used for manufacture of new air conditioning or similar units from 1 January 2010. In other parts of the world the phase out date varies from country to country. Today, all newly manufactured window unit air conditioners and central air conditioning systems in the United States come with R-410A. As an alternative to window-mounted systems, a ductless "split" system is available which also uses R-410A refrigerant.
|Formula||50% CH2F2/50% CHF2CF3|
|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|
|Vapor pressure at 21.1°C (MPa)||1.383|
|Critical temperature (°C)||72.8|
|Critical pressure, MPa||4.86|
|Gas heat capacity (kJ/(kg·°C))||0.84|
|Liquid heat capacity @ 1 atm, 30°C, (kJ/(kg·°C))||1.8|
- Greenhouse Gas Protocol » Download Registration
- AZ-20 Story - About R-410A - R-410A - Honeywell AZ-20 Refrigerant
- Certification - R-410A - Honeywell AZ-20 Refrigerant
- "R-410A Certification FAQ". Mainstream Engineering Corporation. Retrieved 2009-03-05.
- http://www.epa.gov/ozone/title6/phaseout/22phaseout.html EPA R-22 Phase-out
- Honeywell AZ-20 (R-410A) Refrigerant
- "R-410a Material Safety Data Sheet". Honeywell International Inc. Retrieved 2009-07-03.
- "Puron Refrigerant R-410a". Carrier Corporation. Retrieved 2009-07-03.[dead link]
- "R-410A". Honeywell Refrigerants Europe. Retrieved 26 April 2013.