Modelling daylight on inclined surfaces for applications to daylight conscious architecture

In the present work the circumsolar and point source versions of the Perez model have been evaluated for south facing vertical surfaces at Madrid. Different data sets have been used. The coefficients F-ij in the model have been determined using joint experimental data obtained for vertical planes facing N, E, S and W, and also with data for just the south vertical planes. Different values of the half angle a corresponding to the circumsolar region have been used and the most simple version of the model is recommended. (C) 1997 Elsevier Science Ltd.