Rtoc assessment Report 2014 (Slight corrections made in Tables 2-8 and 2-9)

2.4 Concluding remarks

This chapter discussed and provided tabular summaries for identifiers as well as physical, safety, and environmental data for refrigerants including the summary descriptions of refrigerants discussed elsewhere in this report.

Whatever refrigerant is chosen will always have to be a balance between several factors, the availability and cost of the refrigerant (and the associated equipment), the system energy efficiency, the safety and convenience of applicability, environmental issues and many more.

The refrigerants which have emerged since the last assessment report in 2010 address climate concerns, with climate impacts considerably lower than most of the currently used substances, and ozone depletion concerns with the replacement refrigerants for ozone-depleting substances. Among the new refrigerants are several blends based on unsaturated HFCs and a new unsaturated HCFC molecule. Most of these are refrigerants with lower flammability (2L), raising the question of how to handle flammability.

The perfect refrigerant does not exist, and is unlikely to come into existence. The choice will therefore be a selection between the existing low GWP refrigerants (e.g. R-717, R-744 or HCs) and the newly applied and developed chemicals. Many new alternatives are proposed which create a challenge in finding the right refrigerant for each application. One of the important aspects is that refrigerants with low direct impact on climate change are often flammable to some extent.

There is a complex selection process ahead, where the industry will need to find out which of the many proposed new or old refrigerants will be used in each application. In some cases this may be as simple as changing the refrigerant, while in other cases this will require redesign of the system or even change of system topology. The search is a trade-off between cost, safety, energy efficiency, and limiting the need for redesign.

Part of the complexity is that the market is unlikely to be able to support many different refrigerants for the same application. This will leave a period in time, likely to last a couple of decades, where the industry will have to work with both the currently established refrigerants and new refrigerants addressing ozone depletion and/or climate change concerns. In the long run the number of candidates is likely to fall, but it is too early to tell which or even how many of the refrigerant candidates will survive.

2.5 References

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IPCC, 2014 Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013. Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA

ISO 817:2014 ISO 817: 2014. Refrigerants — Designation and safety classification. International Organization for Standardization (ISO)

ISO 5149:2014 ISO 5149: 2014. Refrigerating systems and heat pumps — Safety and environmental requirements. International Organization for Standardization (ISO)

Kajihara, 2010 Kajihara, H., Inoue, K., Yoshida, K., Nagaosa, R., 2010. Estimation of environmental concentrations and deposition fluxes of R-1234yf and its decomposition products emitted from air conditioning equipment to atmosphere. Proc. 2010 Int. Symposium on Next-Generation Air Conditioning and Refrigeration Technology, paper noNS24, Tokyo, Japan

Luecken, 2010 Luecken, D. J., Waterland, R. L., Taddonio, N., Hutzell, W. T., Rugh, J. P., Andersen, S. O., 2010. Ozone and TFA Impacts in North America from Degradation of 2,3,3,3-Tetrafluoropropene (HFO-1234yf), A Potential Greenhouse Gas Replacement. Environmental Science and Technology, 44(1): 44,343–348

McLinden, 2014 McLinden, M. O., Kazakov, A. F., Brown, J. S., Domanski, P. A. 2014. A thermodynamic analysis of refrigerants: possibilities and tradeoffs for low-GWP refrigerants. J. Refrigeration, Volume 38, pp. 80-92

Minor, 2014 Minor, B., Sulc, V., Berger, J. Kold, M., Hegar, M., 2014. R-404A Alternative with Low Compressor Discharge Temperature. Proc. 15^th International Refrigeration and Air Conditioning Conference at Purdue, IN, USA

Papasavva, 2009 Papasavva, S., Luecken, D. J., Waterland, R. L., Taddonio, K. N., Andersen, S. O., 2009. Estimated 2017 Refrigerant Emissions of 2,3,3,3-tetrafluoropropene (HFC-1234yf) in the United States Resulting from Automobile Air Conditioning. Environmental Science and Technology, 43(24):9252–9259

Rajadhyaksha, 2013 Rajadhyaksha, D., Colbourne, D., Sahu, A., Wadia, B. J., 2013. HC-290 as an alternative refrigerant for split air conditioning systems in high ambient temperatures. Proc. IIF-IIR Compressors, Papiernička, Slovakia

Shine, 2005 Shine, K.P., Fuglestvedt, J.S., Hailemariam, K., Stuber, N., 2005. Alternatives to the global warming potential for comparing climate impacts of emissions of greenhouse gases. Climate Change, 68:281-302

Subiantoroa, 2013 Subiantoroa, A., Ooi, K. T., 2013. Economic analysis of the application of expanders in medium scale air-conditioners with conventional refrigerants, R-1234yf and CO2. Int. J. Refrig., Vol. 36, No. 5, pp. 1472–1482

Wieser, 2013 Wieser, M.E., Holden, N., Coplen, T.B., Böhlke, J. K., Berglund, M., Brand, W. A., De Bièvre, P., Gröning, M., Loss, R. D., Meija, J., Hirata, T., Prohaska, T., Schoenberg, R., O’Connor, G., Walczyk, T., Yoneda, S., Zhu, X.K., 2013. Atomic weights of the elements 2011 (IUPAC Technical Report). Pure and Applied Chemistry, Vol. 85, Issue 5, pp. 1047-1078

WMO, 2007 National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA), United Nations Environment Programme (UNDP), World Meteorological Organization (WMO), and European Commission, 2007. Report No. 50, Scientific Assessment of Ozone Depletion: 2006

WMO, 2011 National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA), United Nations Environment Programme (UNDP), World Meteorological Organization (WMO), and European Commission, 2011. Report No. 52, Scientific Assessment of Ozone Depletion: 2010

WMO, 2014 World Meteorological Organization (WMO), 2014, Scientific Assessment of Ozone Depletion: 2014, World Meteorological Organization, Global Ozone Research and Monitoring Project—Report No. 55.

UNEP, 2011 UNEP, 2011. 2010 Report of the Refrigeration, Air-Conditioning and Heat Pumps Technical Options Committee, United Nations Environment Programme (UNEP), Nairobi, Kenya

UNEP, 2012 UNEP, 2012. Handbook for the Montreal Protocol on Substances that Deplete the Ozone Layer (Ninth Edition), United Nations Environment Programme (UNEP), Ozone Secretariat, Nairobi, Kenya

Website

AHRI, 2013 Site for Low-GWP AREP Test reports: www.ahrinet.org/ resources/research tab - then AHRI Low-GWP Alternate Refrigerants Evaluation Program for list of downloadable test reports