Performance study of a dual-function roof solar collector for Chinese traditional buildings application

Architectural integration is a crucial issue in the development and spreading of solar collectors, especially in China, where several traditional buildings have pitch roof with tiles. In this paper, a novel roof solar collector (Type 1) providing hot water and space heating is designed to enable effective collection of solar heat as well integrating naturally. A dynamic numerical model is developed and validated with experimental data. The simulation of the Type 1 collector demonstrates its good characteristics regarding to the thermal insulation and transmission of solar radiation. A linear correlation between the instantaneous efficiency and the reduced temperature is established. Simulated results of the Type 1 collector are further compared with the other two types of roof solar collectors (i.e., Type 2 and Type 3). The comparisons indicated that the similar maximum instantaneous efficiency are achieved. However, the Type 1 collector is preferred as its heat loss coefficient is 54.4% lower compared to the Type 2 collector, and is 65.8% lower compared to the Type 3 collector. The afore-mentioned results confirm that the Type 1 collector introduced has potential to address the issue on the poor architectural quality of roof integrated solar collectors for Chinese traditional buildings.