Application evaluation and optimization of the sunroom in rural residential houses in Southeast Shandong Province, China

The sunroom, a passive solar heat collecting component, is widely used in rural residential houses in Southeast Shandong Province, China. However, many forms of sunroom are applied in this area, and the impact of their application on the indoor thermal environment, energy-saving, and economy is unclear. In this paper, the influence of additional sunroom, courtyard sunroom, and additional sunroom coupling with courtyard sunroom on the indoor thermal environment are tested and studied. A comprehensive evaluation method based on the Energy Plus and dynamic investment payback period analysis is adopted to evaluate the energy-saving rate and economy. Furthermore, the optimization of the sunroom is performed, and the impact of seven key structural factors of sunroom for the indoor thermal environment, energy-saving, and economy was analyzed and evaluated. The additional sunroom has the best performance in improving the indoor thermal environment compared with the courtyard sunroom and the additional sunroom coupling with the courtyard sunroom. Compared to the typical additional sunroom existing in this area, the heating performance of the additional sunroom after comprehensive optimization is improved by 7.1%. Compared with the typical ordinary rural residential house without additional sunroom, the energy-saving rate of the additional sunroom after comprehensive optimization is 44.8 %, and the indoor temperature increases by 2.38 ℃. The conclusions will provide a theoretical basis for improving the indoor thermal environment of rural residential houses in Linyi and other areas in cold zones where solar energy resources are not abundant and the construction of rural residential houses with sunrooms.