Calculation of the distribution of incoming solar radiation in enclosures

Solar heat gains are an important factor in the calculation of cooling loads for buildings. This paper aims at introducing an improved methodology to calculate the distribution of incoming solar energy on the internal surfaces of closed spaces with multiple openings. The independent numerical methodology is based on the view factor theory and in order to justify and prove its functionality, it has been linked to the commercial software of TRNSYS, which normally uses a surface area ratio based algorithm for the same process. For the simplified building structures that have been examined, there are noticeable differences in the spatial and temporal distribution of the absorbed solar energy. The proposed approach is indeed an improvement over the surface area ratio method, having a strong physical basis with relatively little extra computational effort.