Consider a window (2 mx 2 m) on a vertical wall on a clear day (say, March 21st at 14:00). The latitude is 65 N and the longitude is 28 E. The reflectivity is r= 0.18, the orientation angle is +30 and the transmittances for diffuse/reflected and direct radiation are 0.7 and 0.5, respectively. The window is recessed by 0.2 m. Calculate a) total irradiance on the wall b) solar heat load to the space behind the window