Comparison of Computed and Measured Irradiance on Building Surfaces (original) (raw)

To simulate buildings' energy use or gains from building-integrated solar energy systems, information is required regarding solar irradiance on building surfaces. Since measurement databases typically include only horizontal irradiance values, radiation intensity on inclined surfaces must be calculated. The performance of models proposed for this purpose must be evaluated against measurements. Toward this end, this paper considers six options to derive, from horizontal irradiance data, radiation intensity on vertical surfaces. To evaluate these options, simulated vertical irradiance values were compared with respective measurements obtained in Vienna, Austria. The range of errors was found to be rather high for all options.