Daikin Industries, Ltd.

Keitarou Hoshika

Junichi Shimoda

Takashi Ono

Yoshiteru Nouchi

Takuya Kazusa

Hiroshi Nakashima

Ryouta Suhara

Tatsuya Makino

Yukako Kanazawa

Tomohiro Masui

Yoshiaki Yumoto

Hiroki Andou

Naoki Moroi

Masashi Kuroishi

Satoshi Itou

Stress to be imposed on a compressor in reverse cycle operation is reduced. A cycle controller causes an outdoor heat exchanger to function as a condenser and an indoor heat exchanger to function as an evaporator when a reverse cycle executing condition is met, so that a refrigerant circulates in reverse of a heating cycle. A rotation speed controller adjusts a rotation speed of a compressor in a reverse cycle, depending on an index correlated with an amount of frost on the outdoor heat exchanger at a start of the reverse cycle. The rotation speed controller decreases the rotation speed of the compressor in the reverse cycle as the index at the start of the reverse cycle indicates that the amount of the frost on the outdoor heat exchanger is smaller.

Air conditioner with defrost control

An air conditioning apparatus includes a refrigerant circuit having a compressor, a radiator, an upstream side expansion valve, a receiver, a downstream side expansion valve, an evaporator, and a receiver gas vent pipe. Gas vent control is performed so that gas refrigerant is led from a receiver to the suction side of a compressor via a receiver gas vent pipe by opening a receiver gas vent valve. Upstream side expansion valve subcooling control is performed so that the opening of an upstream side expansion valve is changed such that the subcooling of refrigerant is set to target subcooling at the outlet of a radiator. Downstream side expansion valve suction wetting control is performed so that the opening of a downstream side expansion valve is changed such that refrigerant is in a wetting state and the dryness is set to target dryness at the outlet of an evaporator.

Air conditioning apparatus

Growing community of inventors

Osaka, Japan

Keitarou Hoshika