ZEMCH 2019 International Conference Proceedings April.2020 | Page 182
Daylighting Control was applied to meet the recommended illuminance for indoor venue. For
example, when EVB slats are adjusted to allow more sunlight to enter, the amount of indoor lighting is
reduced to meet the level of illuminance required for work environment. Daylighting Method was set
as SplitFlux and Lighting Control Type was set to Continuous, allowing dimming control. Illuminance
Setpoint was set to 500 lux based on the KS recommended level of illumination[10].
2.2. Optimization
The optimum slat angle of EVB was calculated with EngergyPlus in sync with GenOpt. Since the
slat angle of EVB is a continuous variable, Hooke‐Jeeves algorithm was used as an optimization tool.
Objective function J was set as the following formula (1):
min J = E h + E c + E l
(1)
In this formula, E h is set as heating energy demand, E c as cooling energy demand, and E l as lighting
energy demand of the zone. The parameter setting for optimization is indicated in Table 3.
Table 3. GenOpt Optimization Setting
Parameter setting
Parameter
South zone blind slat angle
Min
5
Ini
90
Max
175
Step
5
The optimal angles were calculated for three cases according to different opitimization periods.
For optimization of Case , EVB slats were assumed to be fixed for a year. In Case , different slat
angles were set for each season. Spring was set from March to May; summer, from June to August; fall,
from September to November; and winter, from December to February. For summer and winter, the
period of heating and cooling of the reference building was used. Case was based on the monthly
control of slat angles.
EngergyPlus input files with different Run period according to each case’s optimization period
were generated. One yearly input file for Case , four input files by season (3 months) for Case , and
twelve input files by month for Case were generated. The optimum angles for each file were
calculated through GenOpt.
3. Results and discussion
3.1. Optimized EVB slat angle
In this study, the optimum slat angles of EVB for the given year with weather data of Seoul applied
were elicited, and the improvement of building energy efficiency was analyzed, compared with the
setting without EVB. Table 4. shows the optimized slat angles of EVB calculated for each case.
Table 4. Optimized slat angle of EVB
Cases
Case
Case
Case
Spring
115
Jan Feb Mar
120 125 120
Optimized value
120
Summer
Fall
40
115
Apr May Jun
Jul Aug
120 100
40
40
35
Sep
120
Winter
115
Oct Nov Dec
120 115 115
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ZEMCH 2019 International Conference l Seoul, Korea