Fridges and air-conditioning units not only get hot themselves - which you will know if you have ever touched the back of working fridge or stood outside next to an air-conditioning vent – but they use a lot of electricity, usually generated by burning fossil fuels.
However, bad as this is, refrigeration poses an even greater risk to the climate. When care is taken, the refrigerant gases used in cooling and freezing appliances stay within a closed circuit and are safe. But if they escape into the air as a result of a malfunction, poor service practices or if the appliance is not properly disposed of at the end of its life, the gases contribute to global warming.
For most of the twentieth century, the refrigerant gases used were chlorofluorocarbons (CFCs) and hydrochlorofluorocarbon (HCFC). These are in the process of being phased-out in accordance with the international environmental treaty, the Montreal Protocol, because it was discovered that they damaged the ozone layer that shields our planet from dangerous ultra-violet rays.
The problem is that the heating, ventilation, and air-conditioning (HVAC) industry turned instead to hydrofluorocarbon (HFC) refrigerants as substitutes. Since the 1990s, HFC refrigerants, which do not harm the ozone layer, have been used widely in refrigeration, air-conditioning, and heat pump applications. However, most HFC refrigerants have a massive global warming potential, with an effect that is thousands of times more powerful than CO2 in terms of trapping heat in the atmosphere.
The Kigali Amendment to the Montreal Protocol, which entered into force on 1 January 2019, will help reduce the production and consumption of HFCs but what will HVAC industry use instead?
Engineers from Brazil’s Eletrofrio company have come up with a solution. With the support of Brazil’s Ministry of Environment and the UN Industrial Development Organization (UNIDO), Eletrofrio has developed a new chiller technology using propane as an alternative refrigerant. Propane has zero ozone-depletion potential and very low global warming potential. The short video below provides a more detailed explanation of their project.