PURPOSE: To shorten a start-up time at the starting time of a space heating operation by storing heat contained by working medium after passing through an indoor heat exchanger in a heat storage vessel and using the heat within the heat storage vessel at the time of starting of space heating.
CONSTITUTION: During a normal space heating operation, a four-way valve 2 is set to a space heating operation, and an indoor heat exchanger 3 functions as a condenser. At this time, a valve 4 is opened and a part of working medium flows within a heat storage vessel 5. Therefore, heat contained by the working fluid after passing through the indoor heat exchanger 3 is stored in the heat storage vessel 5. On the following morning, when a controller 25 is operated to restart the space heating operation, the valve 4 is kept closed, and the working medium circulates along a route of the compressor 1, four-way valve 2, indoor heat exchanger 3, a throttle flowpath 10, the heat storage vessel 5, a check valve 6, a bypass pipeline 23, a valve 24 and the compressor 1. Thus, since the working medium is heated with heat from the heat storage vessel 5, it is possible to quicken the discharged of the hot air out of the indoor heat exchanger 3.
SHIMURA MASATOSHI
ITO HIROSHI
