Recommended by the IIR / IIR document

Natural refrigerants in heat pump systems.

Number: 1010

Author(s) : HU B., WU D., LIANG J., WANG R. Z.


By utilizing low-grade waste heat, heat pumps offer efficient ways to reduce primary energy consumption. The vapor compression heat pump system is an important solution to recover low-grade waste heat below 100℃. It is widely used in different residential and industrial applications to supply hot water with output temperature ranging from 30℃ to 160℃. Nowadays, reducing global warming is the most important task in the choice of working fluids. Low-global warming potential (GWP) working fluids, especially natural working fluids, have recently become very popular in vapor compression heat pump systems. To study their performance, characteristics, and application potential, many researchers applied natural working fluids to heat pump systems. A lot of natural working fluid heat pumps were used in different fields and made an important contribution. However, no review systematically introduced the system characteristics, research status, and applications of the natural working fluids. Based on the above researches, this review analyses the studies of 4 kinds of natural working fluids-R717, R718, R744, and HCs (R290, R600, R600a, R601, and R1270) and introduces their system characteristics and research status in detail. For R717 and R744, it also presents a typical case with detailed information.

Available documents

Format PDF

Pages: 6p.


  • Public price

    20 €

  • Member price*


* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).


  • Original title: Natural refrigerants in heat pump systems.
  • Record ID : 30027880
  • Languages: English
  • Subject: HFCs alternatives
  • Source: 14th IIR-Gustav Lorentzen Conference on Natural Refrigerants (GL2020). Proceedings. Kyoto, Japon, December 7-9th 2020.
  • Publication date: 2020/12/07
  • DOI:
  • Document available for consultation in the library of the IIR headquarters only.


See other articles from the proceedings (120)
See the conference proceedings