Method of returning refrigerator oil of air conditioner

摘要

An air conditioner has an outdoor unit and a plurality of room units supplied with a refrigerant from the outdoor unit. The outdoor unit and the room units are connected by a plurality of refrigerant pipes. In a recovery operation for returning refrigerator oil from the room units, the refrigerant pipes and the like to the outdoor unit, the plurality of room units are divided into a plurality of room unit groups, and the recovery operation of the refrigerant is carried out for each of the room unit groups.