REFRIGERANTS Back to the future

Choice of refrigerants has become ever more complex. Refrigeration and heat pump systems are essential parts of modern life and offer potential solutions to the global challenges of feeding the growing world population and reducing energy demand. However, refrigerants are also perceived to degrade the environment through their ozone depletion and/or global warming potential. Further, there are concerns with some refrigerants in terms of safety; either flammability or toxicity. Lastly, there are technical and economic considerations in terms of cost, performance and availability. The ideal refrigerant remains elusive – inevitably there is a trade-off between one or more economic, technical, environmental and social factors. This paper examines refrigerants in light of these constraints and identifies options for the future. While natural refrigerants offer many economic, technical and environmental advantages they do have significant safety constraints. New fluorocarbon refrigerants are being developed but there are significant uncertainties associated with their cost and performance and they are often flammable. Despite the uncertainty, changes to refrigerant costs and availability driven by regulations and taxation regimes provide an opportunity to the refrigeration and air conditioning industry. Decisions need to be bold and visionary rather than defensive and evolutionary.