## Wednesday, May 22, 2013

### Solar urban design using Energy3D: Part III

 Figure 1
In Part I and II, we discussed how solar simulations in Energy3D can be used to decide where to erect a new building in a city block surrounded by existing buildings. Now, what about putting multiple buildings in the block? The optimization problem becomes more complex because students will have to deal with more variables while searching for an optimal solution.
 Figure 2
Suppose students have to decide the locations of two new constructions A and B that have identical shapes. Now they have six options to layout
the two new constructions. Figure 1 shows the results of the solar simulations for all these six layouts in the winter. Placing the buildings in the northeast and northwest parts (the first in the first row of Figure 1) seems to be the best solution for receiving solar heating in the winter. This is not surprising because this layout creates large south-facing areas for both buildings that will get a lot of solar energy in the winter and there are not shadowed very much by the surrounding buildings.

Switch the season to the summer.  Figure 2 shows the results of the solar simulations for all these six layouts in July. Placing the buildings in the southeast and southwest parts (the first in the second row of Figure 2) seems to be the best solution for avoiding solar heating in the summer.

To make a trade-off between winter heating and summer cooling, it seems the southeast and southwest locations are the optimal solution: In the winter the solar heating on the two buildings is the second best (which is not much lower than the highest) and in the summer the solar heating on them is the lowest (which is much lower than the contender).