Technical progress on Protecting the Ozone Layer: Refrigeration, Air Conditioning and Heat Pumps Technical Options Report

The properties of refrigerants for use in the vapour compression cycle have been considered. The vast majority of present equipment utilizes the vapour compression cycle because of its simplicity and good efficiency. The dominance of this cycle is not likely to change simply due to the need to replace CFCs. A refrigerant must satisfy a set of criteria, including nonflammability and low toxicity, the need for favourable thermophysical properties, and other, more practical, considerations. Although many fluids and fluid types have been used as refrigerants in the past, halocarbons dominate today because their unique combination of properties best satisfy these sometimes conflicting requirements.