| Abstract: | This article presents the development of a sufficiently accurate and reliable optical model to predict the lighting and thermal performance of the central sunlighting system (CSS). The model is based on the ray tracing technique to compute the amount of sunlight flux transmission through the light guide to interior spaces of buildings, and absorption of solar radiation within the components of the CSS, which may become solar heat gains indoors. The model is validated using a detailed ray tracing technique and field measurements carried out on a previous prototype. The validation results show that the model predictions are in good agreement with the ray tracing and measurement results. The model can be integrated in existing fenestration design tools, or in whole-building energy simulation software, with significantly lower calculation time compared to the full integration of suitable lighting simulation software. |
