| 摘要 |
PURPOSE:To allow indoor units to individually, selectively perform either cooling or heating operation at the same time by a method wherein at defrosting operation during simultaneous cooling and heating operation, a four-way valve is changed over and the indoor units in cooling operation continue cooling operation, and a first manifold and a first flow control valve, which are connected to the indoor units in heating operation, are closed. CONSTITUTION:At defrosting operation during simultaneous cooling and heating operation in which heating operation is main, the refrigerant in gas state passes through a first branch pipe 6d on the indoor unit side, a first manifold 10 and a changeover valve 8 at the first manifold, and induced into a compressor 1 via a first connecting pipe 6, a forth check valve 33, a four-way valve 2 at the heat source apparatus A and an accumulator 4 so that a circulating cycle is formed and defrosting operation is carried out while cooling operation is continued. First and second on-off valves of the changeover valves 8 of the first manifold connected to the other indoor units (in heating or air blowing operation or out of service are closed. Further, the first flow control valves 9 of the indoor units other than those to be brought in cooling operation are closed. |
