Performance assessment of a solar thermal combisystem in different climate zones

Abstract

As one of the largest energy consumers, the residential buildings have a worthy potential for energy saving. Solar thermal combisystems, which provide the required energy for both domestic hot water and space heating, play a key role in reducing the building energy consumption. The purpose of this paper is to investigate the effect of the climatic conditions on the thermal performance of a solar combisystem using a dynamic simulation by TRNSYS. To this aim, the system performance is considered in five different climate zones including Hot-Dry, Cold-Dry, Moderate-Humid, Hot-semi-Humid, and Hot-Humid. Based on the obtained results, the required energy for domestic hot water is supplied by solar energy in all climate zones, except Moderate-Humid and Cold-Dry climate zones. For providing the required energy for space heating, it is necessary to use the auxiliary energy in all climate zones and all months, except Hot-semi-Humid and Hot-Humid climate zones, which has the small space heating loads because of the high ambient temperature in cold months. The annually total solar fraction of 74%, 61%, 47.8%, 87.9%, and 92% is obtained in Hot-Dry, Cold-Dry, Moderate-Humid, Hot-semi-Humid, and Hot-Humid, respectively. The findings confirm that the building energy consumption decreases considerably using the solar combisystem as a heating system, which resulted in significant energy and economic savings.