Coupling the building simulation tool ZAER with a sunspot model. Case study in Tunis

• A new model to calculate the sunspot position and area is presented.
• Obtained results are in good agreement with published data.
• The developed model is coupled with the building simulation software ZAER.
• The coupled tool permits the precise calculation of the radiation exchanges.
• A simulation case study demonstrates the applicability of the proposed tool.

The accurate modeling of solar heat gains is an important factor to evaluate precisely both thermal comfort and energy consumption in a building. This paper aims at introducing a methodology to calculate the distribution of incoming solar energy on the internal surfaces of closed spaces with multiple openings. The numerical model is evaluated by comparing the obtained results with published data. In order to justify and prove its functionality, it has been linked to the building simulation software ZAER, which assumes that all the sunspot projection through a glazed window is located on the floor. The coupled simulation tool is indeed a useful tool, having a physical basis with relatively little extra computational effort. By linking this tool with a thermal comfort model, we study the influence of a glazed wall belonging to a south oriented room upon the winter thermal comfort of an unconditioned Tunisian building.