Oh, fickle humans! You love sunshine in the winter, when it helps to keep your buildings warm and toasty. But in the summer, you’d rather not have to deal with all that heat. Is there a way to have your cake and eat it too, without losing the advantages of natural daylighting? A recent report presented by the University of Oregon (U of O) at the Association of Collegiate Schools of Architecture‘s 2012 annual meeting says yes.
The report, presented at a session entitled “Design Computation: Parametrics, Performance, Pedagogy and Praxis,” details the findings of the Shaping Light study conducted by Nancy Cheng, a faculty member in the Department of Architecture at U of O. The purpose of the study was to explore how adjustable surface structures can create aesthetically pleasing sun-shading screens that modulate heat gain and light levels in response to various diurnal, seasonal and climatic performance criteria. These adjustable surface structures took the form of 2D sheets arranged in various origami folds to form smart window shades that respond differently to different levels of sun intensity and angles.
Inspiration for the study came from Helmut Koster’s 2004 documentation of the Retro-Lux sun-screen system, which showed how horizontal blind slats with a folded surface can block direct summer sun and bounce winter sunlight deep into a room while maximizing views to the outside world.
The study’s goal with the sun-shading screens was to adapt the paper-folding techniques of origami to architectural applications. From a variety of folding prototypes, researchers settled on an accordion-pleat pattern that provided the best possibilities for a room-size kinetic modular system while still maintaining an interesting visual pattern. Crisp v-folds allowed the surface to compress; vertically flipping the cut motifs on alternate convex vs. concave spines made the petals move in the same direction, so they could bounce sunbeams together. Adding a secondary inverted fold within the petal created a scoop that bounced more light, giving the alternating motifs more visual similarity, and reinforcing the origami fold structure. From these basic shapes, two different lattice-like patterns were created.
These patterns, beyond helping to strategically control solar gain, create appealing patterns of sun and shadow within building interiors. The House in Shadow home design we featured earlier this month is a good example of just how appealing those patterns can be, while offering a smart, green, low-tech solution to the challenges associated with heat gain vs. natural lighting in sunny (and hot) Phoenix, Ariz. But the screens used in the Shaping Light study differ from the rigid brise soleil shades used in that project in that these shades can be cut to specifically control heat gain in different climates.
In fact, the Shaping Light study revealed that the ideal patterns for origami-inspired sunshades differ significantly based on climate, but that poses no great challenge. “Parametric software allows us to quickly reconfigure a screen based on changing site and climate conditions,” Chen said, in the report. “A screen designed for the Portland climate could quickly be adapted to the climate of Alaska or Arizona with relative ease. We’re only beginning to scratch the surface of what parametric modeling can offer us.”
Whether we see such sunshades shaped by such “digital origami” modeling software become a common feature in green building projects remains to be seen. But as far as green technology goes, this one looks a whole lot cheaper than, say, solar air conditioning.