HEAT PUMP TYPE AIR CONDITIONING SYSTEM AND METHOD

PROBLEM TO BE SOLVED: To accomplish an operation without exchanging heat storage material all through summer and winter seasons by a method wherein an accumulation means is provided in parallel with an outdoor unit of a heat pump circuit to store power during an off-peak period as heat source for air conditioning and a heat storage material is arranged in the accumulation means to develop a latent heat action due to a phase change within a specified temperature range. SOLUTION: In the summer season (cooling) operation, a gaseous medium discharged from a compressor 10 radiates heat with an outdoor unit 13 to be liquefied and supplied to a room unit 14 via an expansion valve to cool a zone to be air conditioned by an endothermic effect (cooling) effect obtained with evaporation here. During the cold heat storage period, the medium liquefied by the outdoor unit 13 is sent to a heat storage means 12 via the expansion valve to store a cold heat capacity. The cold heat storage operation is implemented using midnight power. The cold heat stored is used to make up for condensing action during the cooling operation. In this case, the heat storage material arranged in the heat storage means 12 employs a substance which causes a phase change between a solid phase and a liquid phase in a temperature range of about 5-35 deg.C and delivers a latent heat action.