Hitachi-johnson Controls Air Conditioning, Inc.

Tatsuya Mochida

Yoshiyuki Akiyama

Kazumoto Urata

Koji Naito

Kazuhiko Tani

Masami Inaba

A hot gas bypass circuit that connects a discharge side of the compressor and a portion between the heat source side heat exchanger and the expansion valve, an on-off valve that opens and closes a channel of the hot gas bypass circuit, and a control device performing control to select one of hot gas bypass defrosting and reverse cycle defrosting according to a frosting amount on the heat source side heat exchanger and perform defrosting. The control device controls to open the on-off valve of the hot gas bypass circuit such that a part of a refrigerant discharged from the compressor is supplied to the heat source side heat exchanger via the hot gas bypass circuit and, the control device switches switch the four-way valve such that the refrigerant discharged from the compressor is supplied to the heat source side heat exchanger after passing through the four-way valve.

Growing community of inventors

Tokyo, Japan

Tatsuya Mochida