Refrigerants: There is still no vision for sustainable solutions

The history of refrigerants is elaborated and the international agreements concerning protection of the ozone layer and climate change are presented. We have to learn from mistakes in the past. There are countries with successful policies. The most used natural refrigerants are presented: ammonia, CO2 and hydrocarbons. Their advantages and disadvantages are described and their applications. The fourth generation of fluorine-based gases is elaborated: hydrofluoroolefins. The most used are R1234yf and R1234ze(E), and their blends with HFCs. A vision for the future with environmental refrigerants is described. Innovations such as new types of components, new concepts of low charge ammonia systems and their expansion in many applications. There are improvements of CO2 systems installing parallel compressors, ejectors as an expansion device and usage of evaporative condenser. There is a big potential of R290 to be a refrigerant no. 1 for split air conditioning units. Finally, a new approach is recommended. (C) 2017 Elsevier Ltd and IIR. All rights reserved.