AIR-CONDTIONING APPARATUS WHEREIN A PLURALITY OF INDOOR UNITS ARE CONNECTED TO OUTDOOR UNIT

摘要

An air-conditioning apparatus comprises at least one variable-capability compressor which is contained in a casing together with a lubricating oil, and at least one fixed-capability compressor which is also contained in a casing together with a lubricating oil. The capability of the variable-capability compressor and the number of fixed-capability compressors to be driven, are controlled in accordance with the sum of the air-conditioning loads of a plurality of indoor units. The casings are connected together by means of an oil-balancing pipe. The air-conditioning apparatus further comprises a plurality of oil-balancing devices. These oil-balancing devices are driven on the basis of different control patterns and distribute the lubricating oil between the casings by way of the oil-balancing pipe. The oil-balancing devices are selectively driven in accordance with both the control of the capability of the variable-capability compressor and the control of the number of fixed capability compressors to be driven.