2022-05 Mobile air conditioning system series : Market status and a case study of electric buses in China

Mobile air conditioning (MAC) systems worldwide have long relied on chlorofluorocarbons (CFCs) as refrigerants in their cooling cycles. Most of these CFCs are ozone-depleting substance (ODS) with very high global warming potential (GWP). Refrigerants and ODSs that have high GWP and that leak from operating systems into the atmosphere result in severe climate impacts, most notably ozone layer depletion. One example of such CFCs is dichlorodifluoromethane (R-12) which has serious ozone depleting potential (ODP). R-12 was still in operation until ~1990 in most developed countries, when it was phased out of markets by the Montreal Protocol on Substances that Deplete the Ozone Layer, also known as Montreal Protocol, which was adopted in 1987 and entered into force in 1989 (United Nations, 1987).