ZEMCH 2019 International Conference Proceedings April.2020 | Page 183
For Case with fixed angle control for the year, the optimized angle was calculated as 120. In
Case , the optimized angle was 115 for both heating season and intermediate season. In Case , the
optimized slat angles of EVB ranged between 115 and 125 for heating season and intermediate season.
The optimized angles for cooling season were calculated between 35 and 40.
3.2. Energy demand of the zone
Figure 2 shows the comparison of annual energy demand for cooling, heating, and lighting
between the three cases with EVB and the case without EVB when the optimized angles for each case
were applied.
Figure 2. Annual energy demand
As the zone without EVB shows higher cooling energy demand, the zone is shown to be a cooling
dominant zone. For Case , with the yearly optimal angle applied to EVB slats, lighting energy demand
shows a 15 % increase, but the total energy demand shows an about 6% decrease with 14% decrease
and 7% decrease for cooling and heating energy demand, respectively, compared to the case without
EVB.
For Case , where the optimal angles were adjusted per season, lighting energy demand and
heating energy demand show 23% and 3% increases, but the total energy demand shows a 13% decrease
with a 32% decrease in cooling energy demand.
Case , with the optimal EVB slat angles adjusted per month, shows the most saving for energy
demand compared with the other two cases. Lighting energy demand shows a 23% increase, but the
total energy demand shows a 15% decrease with a 32% decrease in cooling energy demand and a 2%
decrease in heating energy demand.
(a)
Optimal Control of External Venetian Blinds Considering Energy Performance
(b)
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