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Development of Refrigeration and Air-Conditioning Technologies for Practical Use of Next-Generation Low-GWP Refrigerants

Project overview

Project period: FY2023 to FY2027, budget: 500 million yen (FY2023)

Refrigerants used in refrigeration and air conditioning equipment have been converted from ozone-depleting specified fluorocarbons*1 (CFCs*2 and HCFCs*3) to alternative fluorocarbons*4, such as HFCs*5, but alternative fluorocarbons have a high greenhouse effect. Progress converting to alternative fluorocarbons increases emissions. In light of this, international moves to strengthen regulations on CFC substitutes are currently underway. In particular, the 2016 amendments to the Montreal Protocol*6 set forth a new obligation to phase out the production and consumption of alternative fluorocarbons, and developed countries are required to reduce their production and consumption by 85% from the base year by 2036. In addition, it is necessary to reduce the amount of emissions to practically zero in order to become carbon neutral by 2050. Among greenhouse gases, the emissions from alternative fluorocarbons have been on the rise, and measures to curb their emissions are a pressing issue. In particular, there is an urgent need to accelerate the technological development and social implementation of next-generation refrigerants and equipment that can replace alternative fluorocarbons.
On the other hand, many of the next-generation refrigerant candidates, which have a very low impact on global warming, have high technical hurdles to overcome to achieve the same or better equipment performance as conventional HFC refrigerants. Furthermore, due to safety issues (flammability, chemical instability, and so on), refrigeration and air-conditioning equipment using next-generation refrigerants has not yet been put into practical use worldwide. One of the main reasons for this is the lack of a standardized evaluation methods for the basic characteristics of next-generation refrigerants and for safety and risk assessment in the case of using next-generation refrigerants. Another issue is that although next-generation refrigerants are being applied in some refrigeration and air-conditioning equipment fields, there are areas where they have not been widely adopted due to technical issues.
In this project, NEDO will establish the basic technology for design guidelines of applicable equipment by focusing on residential air conditioners and other equipment for which next-generation refrigerants have not yet been determined to replace CFC substitutes comprehensively: from screening new refrigerant mixtures to developing and evaluating application technologies. NEDO also encourages the early development and marketing of next-generation low-GWP refrigerants and their applicable equipment by the private sector. This will be achieved through the technological development of elemental and peripheral equipment necessary for the widespread use of next-generation low-GWP refrigerants for residential and commercial air conditioning equipment along with commercial refrigeration equipment.

  • *1Fluorocarbons: Freon is a trademark for refrigerant. Used as a generic term for refrigerants and industrial gases that are fluorides in turn.
  • *2CFC: Abbreviation for chlorofluorocarbon. A man-made compound in which all the hydrogen in low-molecular-weight organic substances is replaced by fluorine and chlorine. A type of fluorocarbon.
  • *3HCFC: Abbreviation for hydrochlorofluorocarbon. A man-made compound in which hydrogen in low-molecular-weight organic substances is partially replaced by fluorine and chlorine. A type of fluorocarbon.
  • *4Alternative fluorocarbons: Compounds such as HFCs (hydrofluorocarbons) that do not contain chlorine, which is a source of ozone depletion.
  • *5HFC: Abbreviation for hydrofluorocarbon. Although not ozone-depleting, it is a potent greenhouse gas and is subject to emission reductions under the Paris Agreement.
  • *6Amendments to the Montreal Protocol in 2016: Adopted at the 28th Meeting of the Parties (MOP28) to the Montreal Protocol held in October 2016 in Kigali, the capital of Rwanda. Referred to as the "Kigali Amendment."
  • Overview diagram summarizing the R&D described below
    Outline of Implementation

Details of Research and Development

R&D Item (1) Development and evaluation of low GWP mixed refrigerants suitable for home air conditioning

Based on the knowledge of refrigerant mixtures obtained in related research and development projects to date, NEDO will quickly narrow down the HFO refrigerant mixture candidates that can be implemented for residential air conditioners. It will also develop basic technologies for the development of heat exchangers, compressors, and other elemental equipment compatible with the HFO mixed refrigerants to be implemented, as well as models and evaluation methods to assess the safety of the refrigerants and the environmental impact of the compatible equipment.

R&D Item (2) Development of equipment compatible with low-GWP refrigerants (residential/commercial air conditioners, refrigerated/freezer showcases, and others)

By applying the results of past related research and development projects and the knowledge of refrigerant and air conditioning element technologies for residential air conditioners in this project, NEDO will develop equipment and peripherals that are compatible with next-generation low-GWP refrigerants and achieve performance equivalent or superior to that of CFC products currently on the market.

Refinement and evaluation of optimal refrigerant mixtures
Figure showing the items for narrowing down and evaluating the optimal refrigerant mixture: thermophysical properties, performance, availability, GWP, safety, and cost
Elemental and peripheral equipment development
Images of an air conditioner and a refrigeration showcase

Basic information

Technical field Fluorocarbon countermeasures
Project code P23001
Department in charge Environment Department (TEL: +81-44-520-5293)

Last Updated : November 10, 2023