Optimal sizing of a solar thermal system in building based on simulation results of Polysun

Due to a series of environmental pollution and energy crisis, much attention is focused on developing clean renewable energy. Many institutes in different nations have interesting in studying the usage of solar heaters into buildings. In China, solar energy heat usage technology in buildings has a big potential market and has been rapidly developed. So, in this paper, a solar thermal system in building used for space heating and domestic hot water production has been studied. A simulation calculation method is put forward by Polysun for finding the optimal size of three main components for the solar thermal system, including the tilt angle of collectors, volume of the buffer and area of the collectors. Moreover, the relative impact of those three parameters on the optimizing indexes (SF, Etot and f) is investigated where all indexes are most affected by the area of the collectors while the tilt angle of collectors and the volume of buffer both present a relatively small influence.