Advanced Building Simulation

180 Mahdavi
Preference index Preference index
1.0
0.8
0.6
0.4
0.2
0
a
0
a
b
b
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
1.0
0.8
0.6
0.4
0.2
0
c
0 3 6 9 12 15 18 21 24 27 30
d
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
e
0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0
the study of the relative implications of the impact of various performance indicators
in view of preferable control strategies. To generate suitable schemes for daylightresponsive
electrical lighting control, we considered two possibilities. The first possibility
involves the simultaneous assessment of various combinations of the states
of the daylighting and electrical lighting control devices. This strategy requires, due
to the potentially unmanageable size of the resulting control state space, a reduction
of the possible number of states: Let D be the number of luminaires (or luminaire
groups) and P the number of dimming positions considered for each luminaire. Using
Equation (7.4), the total number of resulting possible combinations (control states)
can be computed. For example, for D � 4 and P � 10, a total of 1,048,576 possible
electrical lighting control states results. Assuming eight daylight control states (eight
louver positions), a total of 8,388,608 simulation runs would be necessary at each
c, d, e
2 4 6 8 10 12 14 16 18 20
Figure 7.10 Illustrative preference functions for selected performance variables (a) Average
illuminance in lx; (b) Uniformity; (c) DGI; (d) CGI; (e) GCRT.