US Patent 7788945 Air conditioner, heat source unit, and air conditioner updating method

An air conditioner is configured by appropriating existing refrigerant pipes of an existing air conditioner to update indoor units and an outdoor unit of a refrigerant circuit of the existing air conditioner. The air conditioner is disposed with an updated refrigerant circuit and a mixer disposed in the updated refrigerant circuit. The updated refrigerant circuit is filled with working refrigerant and refrigerating machine oil that include an acid trapping agent that detoxifies acid components remaining in the refrigerant pipes. The mixer mixes the acid components with the acid trapping agent during refrigeration cycle operation of the updated refrigerant circuit.