Exploring Application of Ice Source Heat Pump Technology in Solar Heating System for Space Heating

A heat pump is an energy-effective technique to provide heating for buildings using available heat sources from the environment. Solar irradiation and ambient air are the most accessible heat sources among different heat sources; however, they are unstable for a day or several days. A large volume of the heat storage tank is usually required to provide a stable heating supply. As the most commonly used media for heat storage, water has a limitation on the heat storage temperature, i.e., above 0 °C, limiting its density of energy storage. This paper presents an experiment that evaluated the performance of a developed ice source heat pump used for assisting a solar heating system. The ice source heat pump can extract both sensible heat and the latent heat of water freezing, which doubles the density of energy storage and increase the heating output by 50%. The experiment results showed that the solar heating system tested could supply hot water at the highest temperature of 60 °C (with intense sun irradiation) and the lowest temperature of 40 °C (without sun irradiation). The min COP of the ice source heat pump was three, measured when the heat pump extracted heat from the ice water. This technology could be used for domestic heating with 50% reduced heat storage volume.