Alternatives to HCFCs in the Refrigeration and Air Conditioning Sector 47 S ection 02 Introductionyears, the cases selected for these sectors are more of a general nature. These non-ODS systems can be used to replace R-22 in new installations with minimal technology and cost differences. The remaining case studies have been selected to illustrate alternatives for replacement in existing equipment, and how non-HFC alternatives (often called “natural refrigerants”) can be used. Each case has some elements that have been considered to be of special interest to illustrate the technologies that are now entering the commercial market after often extensive research and field testing. When it comes to hydrocarbons and carbon dioxide these products are proven in several applications, but there are divided opinions on their cost effectiveness and energy efficiency in different applications. There are strong commercial interests in favour and against different solutions, and un-biased information is often hard to find. The case studies presented here represent technologies currently offered on the commercial market, even if they do not have big market shares at present. The descriptions, results and arguments for the selection of the particular technology have been supplied by companies that have been involved in the projects, and this information, although edited, has not been validated by the author or UNEP. To reflect the arguments used, it was considered important to describe the complexity of situation in the market where several new technologies are competing for market shares, with an overall drive for decreased environmental impact including improved energy efficiency. Th is section provides examples of the application of alternatives to HCFCs in the air conditioning and refrigeration sector. Since the most widely used HCFC refrigerant is R-22, the focus is on applications where R-22 is commonly used. In many applications where CFCs were used prior to the CFC phase out, a change to HCFCs took place. In these applications, e.g. commercial refrigeration, the alternatives designed for commercial refrigeration (e.g. to replace R-12 and R-502) will be a preferred solution rather than those developed for R-22, e.g. air conditioning applications. The technology used to retrofit from HCFC is to a large extent the same as when retrofitting from CFC-based systems. One major difference is that the properties of currently-available HFC alternatives are not as close to R-22 as R-134a is to R-12 and R-404A/R-507 is to R-502. As the development of refrigeration systems for low-GWP alternatives such as hydrocarbons, ammonia and carbon dioxide progressed, their market presence increased rapidly although starting from a very low market share. The case studies do not reflect the market shares of the respective technologies, but are selected to show the technologies available on the commercial market today. Since the alternative HFC technologies for two main R-22 sectors, i.e. split air conditioning and chillers are well established and have been readily available on the market for more than ten 02 Case studies Alternative technologies in different applications