REFRIGERANTS
How to avoid going back to the future
John Poole of Refrigerant Solutions talks about the development of refrigerant gases in relation to the development of equipment.
F
rom the late 19th century to the 1920s, commonly used refrigerants were markedly hazardous, notably
hydrocarbons (flammable), methyl chloride (flammable and toxic), sulfur dioxide (toxic) and ammonia (flammable and toxic). Non- flammable carbon dioxide was limited by its very high pressure and low critical temperature to industrial refrigeration, including refrigerated ships, where other refrigerants presented too great a risk. Chlorofluorocarbons (R11, R12, R114)
and hydrochlorofluorocarbons (R22) were commercialised in the 1930s and grew rapidly after the war, the range being extended by azeotropes R502 and R500. But in the 1970s CFCs and HCFCs were found to destroy stratospheric ozone, so are now being phased out under the Montreal Protocol. These nonflammable, low toxicity and efficient fluids have largely been replaced by hydrofluorocarbons having similar properties, but which crucially do not deplete ozone. Nevertheless, they have high direct Global Warming Potentials (GWP) and themselves are now being phased down globally. Wherever you stand in the debate
around global warming, ever increasing regulations
internationally are being enacted, targeted at reducing the emissions of global warming gases. But reducing perceived environmental impacts must not be achieved by exposing customers and engineers to extra risks inherent in the use of the hazardous fluids common in the early days of refrigeration. Despite HFCs directly contributing less than 2% to the global warming attributed to human activity, the GWPs of HFCs are increasingly being targeted by international regulations, such as the Kigali amendment to the Montreal Protocol, for phasing them down. In particular, the European F Gas regulation is a flawed legislative instrument that ignores the indirect warming impact of carbon dioxide emissions from fossil fuel combustion to generate the power needed to run the equipment. Since the refrigeration and air-conditioning industry (RAC) is a significant consumer of energy, increased efficiency must be a key in any sustainable future strategy. The F Gas Regulation imposes excessive economic
costs on the purchasers of refrigeration and air conditioning equipment for minimal environmental gain. But accepting that HFC phase down is a
‘done deal’, future refrigerants will need the lowest possible GWPs combined with high efficiencies and inherent safety. The so- called natural refrigerants, promoted by
18 December 2020
www.acr-news.com
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