Solar modeling the UMaryland Ellipse
The newly constructed Physical Sciences Complex on the campus of the University of Maryland in College Park, includes a beautiful elliptical oculus passing upward through a three-story office bridge over a pedestrian plaza space. Created as an iconic architectural landmark, the opening is designed to have much the same visual impact in the space below as the Pantheon’s in Rome. Inside the building, open pedestrian spaces surround the curtain walled oculus, adding an additional dimension to the experience of the space.
Unfortunately, the installed glass curtain wall system is also highly reflective and creates a solar convergence to rival those at the Vdara Hotel and Disney Concert Hall. The elliptical form of the opening does not create as precise a focus as does the curve arc at the Vdara, but it is nonetheless highly effective at concentrating light rays into one area, resulting in a hot spot intense enough to melt polystyrene panels being installed into the space.
HDR architects asked me to assess the intensity and location of the hot spot, which I accomplished using a combination of Heliotrope and additional Slate Shingle modeling and solar routines. I found that the hot spot below the ellipse is active throughout a 6-hour mid-day period for 3 months before and 3 months after the summer solstice. Furthermore, the changing curvature of the ellipse moves the hot spot as the sun moves, creating a pattern of focus that changes throughout the day.
These images illustrate the patterns of light movement that create the hot spot in the plaza. Fortunately they are mostly confined to an earth berm intended, not for human inhabitants, but for plantings. The heat levels are too high for even the hardiest of cacti, however, leading to some tough redesign decisions. Possibilities include testing to see whether window film treatments are sufficient to mitigate the problem, or designing and installing shades to either mitigate or eliminate the convergence entirely.