[EN 14511-1:2022, 3.35]:split system air conditioner or heat pump incorporating a single refrigerant circuit providing variable capacity with three or more steps, multiple indoor units, each capable of being individually controlled and one or more outdoor units.Note 1 to entry: This system is capable of operating as a heat pump where recovered heat from the indoor units operating in the cooling mode can be transferred to one or more units operating in the heating mode.Note 2 to entry: This can be achieved by a gas/liquid separator or a third line in the refrigeration circuit.