According to the principle of cascade use of energy

a recycling air conditioning system combining water thermal storage and phase change material (PCM) thermal storage was presented.A water thermal storage and a phase change thermal storage are installed in series before the air cooled condenser.Superheated refrigerant vapor from the compressor flows through the phase change thermal storage first

the heat of superheating being stored in it

and then flows through the water thermal storage and exchanges heat with the water.Part of latent heat of condensation is stored in water thermal storage.The result of the experiments indicated that the heat recovery air conditioning system can effectively recover 19.6% of the condensing heat. When air conditioning does not work

the hot water produced under smaller flow rate is above 40℃ and produced under greater flow rate is above 40℃ also with air conditioning working. It not only can save energy but also satisfy the hot water demand of users.