The (R)Evolution of refrigerants - How did we get here? Where are we going?

19 Nov 2020 16:00 to 17:00

Exclusive Event for IOR Members Only


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The (R)Evolution of refrigerants - How did we get here? Where are we going?

As we enter the “fourth generation” of refrigerants, this talk will consider the evolution of refrigerant molecules, the ever-changing constraints and regulations that have driven the need to consider new molecules, and the advancements in the tools and models used to identify new molecules and design the (also evolving) equipment to use them. These separate aspects are intimately intertwined and have been in more-or-less continuous development, even if sometimes out-of-sight of the mainstream refrigeration industry. R134a, for example, was first reported in the chemical literature in the 1930s, and the search for new refrigerants continued through the 1990s even as the HFCs were becoming the dominant refrigerants in commercial use. The current situation remains in flux—some applications have converged on a new technology (e.g., R1234yf in automotive air conditioning) while other sectors continue to weigh competing tradeoffs with no obvious “best” solution. It is almost certain that refrigerants will continue to evolve in the future, and it will be changing constraints that will drive this evolution. Future constraints could be relaxed (e.g., to allow more flammable fluids) or, perhaps, to allow a very small ODP in return for a much-reduced GWP; or they could become more stringent, drawing a wider “system boundary” on the environmental consequences of refrigerants to also include the inputs to their manufacture and/or the impact of their breakdown products on the environment.



Dr Mark O. McLinden- Research Chemical Engineer, National Institute of Standards and Technology

Mark joined the National Bureau of Standards in 1984, and his current research in the NIST Applied Chemicals and Materials Division focuses on highly accurate measurements of fluid properties over wide ranges of temperature and pressure and the design and fabrication of instruments for such measurements. Throughout his career, Dr McLinden has researched “new” refrigerants; in the 1990s replacements for the ozone-depleting CFC and HCFC refrigerants were the focus, and more recently, his attention has turned to fluids having low global warming potential (GWP). He is the author or co-author of more than 100 peer-reviewed publications. Dr McLinden holds a B.S. from the University of Missouri and M.S. and PhD degrees from the University of Wisconsin, all in chemical engineering.


More information 

This paper was originally presented as a keynote address at the International Rankine 2020 Conference . IOR members who were unable to take part in the international event now have the opportunity to hear the presentation given by  Mark McLinden during this event and the discussion that followed. 

IOR members joining the webinar will able to download a supporting paper directly from the webinar. It will be available under handouts.