Distribution of solar radiation in glazed spaces and adjacent buildings. A comparison of simulation programs

Energy simulation programs are commonly used to calculate the climate and energy requirements in glazed spaces and adjacent buildings. However, these programs have usually been developed to study buildings with ordinary window sizes. Comparisons of four simulation programs were carried out for a sunspace with an adjacent room. The distribution of solar radiation between the glazed space and the adjacent room as well as the portion of short wave radiation lost to the outside were studied. The programs show very large differences. The more simple calculation methods overestimate the utilization of solar radiation. This means that the temperature in the glazed space and also cooling requirements will be overestimated. In addition, heating requirements will be underestimated. The investigation shows that simulations of glazed spaces must be based on a geometrical description of the buildings, taking into account transmission through windows, reflection and absorption.