Saturday, June 1, 2013

Solar urban design using Energy3D: Part IV

In Part I, II, and III, we mainly explored the possible layouts of buildings in the city block and their solar energy outputs in different seasons. In those cases, the solar radiation on a new construction is mostly affected by other new constructions and existing buildings in the neighborhood. We haven't explored the effect of the shape of a building. The shape of a building is what makes architecture matter, but it also has solar implications. In this blog post, we will explore these implications.

Figure 1: Compare solar heating of three different shapes in two seasons.
Let's start with a square-shaped tall building and make two variations. The first one is a U-shaped building and the second is a T-shaped one. In both variations, the base areas and the heights are identical to those of the original square-shaped building. Let's save these buildings into separate files and don't put them into the city block. We just want to study the solar performance of each individual building before we put them in a city.

The U-shaped building has a larger surface area than the square-shaped and the T-shaped ones (which have an identical surface area). Having a larger surface means that the building can potentially receive more solar radiation. But the two wings of the U-shaped building also obstruct sunlight. So does the U-shaped building get more or less energy? It would have been very difficult to tell without running some solar simulations, which tell us that this particular U-shaped building gets more solar energy than the square-shaped one both in the winter and in the summer.

In comparison, the T-shaped building gets the least amount of solar energy in both seasons. This is not surprising because its surface is not larger than the square-shaped one but its shape obstructs sunlight to its western part in the morning and to its eastern part in the afternoon, resulting in a reduction of solar heating.


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