Question 3 (Total 20 marks) (X = 5 for odd no. in the second last digit of student ID and X = 0 for zero or even no. in the second last digit of student ID) Fig. 1 show a room with windows (shaded parts) on two adjacent walls. The window height is 3 m and the sill is 0.5 m above the floor. The reflectances are 0.7 for the ceiling, 0.6 for walls, 0.4 for the floor and 0.5 for the window. There is no obstruction outside the windows. The windows have a visible transmittance of 0.7X. 8 m 3.5 m 10 m 16 m Fig.1 Room with adjacent windows Find the daylight factor in % at the centre on the floor. Sky component data are given in Table 2. The formula for the internally reflected component is given by: IRC = TW -(40R, +5R.). A(1-R) h/d w/d 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.4 1.6 1.8 2.0 2.5 3.0 4.0 6.0 1.3 2.5 3.7 5.9 6.9 9.0 9.6 10.7 11.6 12.2 12.6 13.0 13.7 14.2 14.6 14.9 15.0 90 5.0 1.2 2.4 3.7 5.9 8.3 8.8 9.4 10.5 11.1 11.7 12.3 12.7 13.3 13.7 14.0 14.1 14.2 790 4.0 9.2 10.3 10.9 11.4 12.0 12.4 12.9 13.3 13.5 13.6 13.7 760 3.5 0 10.1 10.6 11.1 11.8 12.2 12.6 12.9 13.2 13.2 13.3 740 3.0 3.5 9.8 10.2 10.7 11.3 11.7 12.0 12.4 12.5 12.6 12.7 720 9.6 10.0 10.5 11.1 11.4 11.7 12.0 12.2 12.3 12.3 70 9.8 10.2 10.8 11.1 11.4 11.7 11.8 11.9 11.9 690 UNNN 9.5 10.0 10.4 10.7 11.0 11.2 11.3 11.4 11.5 670 9.6 10.0 10.2 10.5 10.7 10.8 10.9 10.9 660 9.5 9.9 10.0 10.1 10.2 10.3 630 2.0 3.0 9.8 9.9 9.9 2.8 38 8% 4 9894898989 .82 2.4 3.8 2.3 3.6 0.71 3.3 0.65 1.9 3.0 1.0 0.57 1.1 1.7 2.6 0.9 0.50 0.99 1.5 2.2 2.6 4.2 0.8 0.42 0.83 1.2 3.5 390 70.33 0.68 0.97 1.3 1.5 2.3 2.6 2.8 2.8 350 0.6 0.24 0.53 0.74 0.98 1.2 1.3 1.5 1.8 2.0 2.0 2.0 2.1 310 0.5 0.16 0.39 0.52 0.70 0.82 0.97 1.0 1.2 1.3 1.4 1.4 1.4 1.4 1.5 1.5 1.5 1.5 1.5 1.5 270 0.4 0.10 0.25 0.34 0.45 0.54 0.62 0.70 0.75 0.82 0.89 0.92 0.95 0.95 0.96 0.96 0.96 0.97 0.97 0.98 0.98 220 0.3 0.06 0.14 0.18 0.26 0.30 0.34 0.38 0.42 0.44 0.47 0.49 0.50 0.50 0.51 0.51 0.52 0.52 0.52 0.53 0.53 170 0.2 0.03 0.06 0.09 0.11 0.12 0.14 0.16 0.20 0.21 0.21 0.22 0.22 0.22 0.22 0.23 0.23 0.23 0.23 0.24 0.24 119 0.1 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.05 0.06 0.06 0.06 0.06 0.07 0.07 0.07 0.07 0.08 0.08 60 Note: Ratio h/d=Height of window head above working plane: distance from window Ratio w/d=Width of window to one side of normal: distance from window 8 =Angle of obstruction