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Thermodynamics of the New Refrigerants



Mark O. McLinden


As the refrigeration industry moves towards low-GWP refrigerants the number of acceptable refrigerants is decreasing due to new environmental constraints, but, at the same time, a variety of new options are becoming available. These "new" refrigerants include new molecules, such as the HFOs containing a carbon-carbon double bond, as well as some very "old" fluids, such as ammonia, carbon dioxide, and hydrocarbons. The HFC refrigerants, although being phased down, remain in use--especially as blend components. Here, some of the thermodynamic characteristics that underpin the choice of a refrigerant are reviewed; together the thermodynamic and environmental constraints result in a limited number of suitable fluids. Refrigerants have differing thermodynamic characteristics, and these determine their relative performance in a refrigeration cycle. The design engineer must recognize and balance the tradeoffs presented by different refrigerants and design the system to best accommodate the properties of the chosen fluid.
Conference Dates
August 24-30, 2019
Conference Location
Conference Title
The 25th IIR International Congress of Refrigeration


Ammonia, Carbon Dioxide, GWP, Hydrofluoroolefins, Refrigerants, Refrigeration Cycle, Thermodynamic Properties Thermodynamic Properties


McLinden, M. (2019), Thermodynamics of the New Refrigerants, The 25th IIR International Congress of Refrigeration, Montreal, -1, [online], (Accessed June 23, 2024)


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Created August 23, 2019, Updated July 8, 2020