Advanced Building Simulation

184 Mahdavi
Illuminance (lx)
120
100
80
60
40
20
0
0 20 40 60 80 100
Dimming level (%)
Figure 7.11 Measurements for interior illuminance rule: The impact of the dimming level of the
luminaires 1, 2, 3, and 4 on the measured illuminance (for sensor E1).
Table 7.9 Rules used for implementation
Node Rule
MC-EL_1 and MC-EL_2 Prohibit independent switching
(i.e. lights dim together)
MC-EL_Lo_1 and Fully utilize daylighting before
MC-EL_Lo_2 electric lighting
MC-Lo_VA_1 and Fully utilize solar heat before
MC-Lo_VA_2 mechanical heating
MC-II EL_Lo_VA_1 Choose option that meets set-point
need of all sensors
To implement the simulation-based control method, the Nodem energy simulation
tool was used (Mahdavi and Mathew 1995; Mathew and Mahdavi 1998). Nodem predicts
interior temperature by balancing heat gains and losses in the space. The local heating
valve was simulated as a heat gain to the space, which was added to other internal
loads in Nodem. It was necessary to determine how much heat gain to each space is
possible through the water local heating system at each valve state. The local supply
temperature is dependent on the central supply temperature, which changes continually
due to the changing needs of the building. The heat supplied to the space is dependent
on local supply temperature. Thus, the amount of heat provided by the local heating
system changes with constant valve state. Estimating the losses from the mullion pipes
to the space was accomplished by estimating the local water flow rate and measuring
the surface temperatures at both ends of the pipe. Over the course of several days in
the winter, the water mullion valve was moved to a new position every 20 min, and the
resulting surface temperatures measured. The heat loss to the space was calculated for
a valve position of 100% and binned according to the central system water supply
temperature. The results are graphed in Figure 7.12 and provide the basis for a rule
used by the DC-Va nodes to estimate the heat gain values needed for simulation.
3
1
2
4