Outside the horizontal blinds effects on indoor light environment

The simulation room size is: 6 m × 4 m × 3 m, the window facing south, with size 2 m × 1.8 m, in which the width of the window frame is 0.15 m. Room model is shown in Figure 1. Figure 1(a) for the model with no shutter, Figure 1(b) as the model with blinds.