Brought to you with support fromA 23-acre public botanical garden in Denver—which contains North America's largest collection of plants from cold temperate climates around the world—has received a new science center inspired by biomimicry, technology, and the landscape. The project was a highly collaborative output from Burkett Design and StudioNYL. The appropriately titled “Science Pyramid” began formally as an inversion of an adjacent depressed triangulated amphitheater. The triangulated structure was initially planned as a self-supporting structural shell of honeycomb-shaped glass units, inspired by beehive structures. With a desire to control lighting for multimedia displays, the design evolved to an opaque shell with fiber cement panels, building integrated photovoltaics (BIPV), and electrochromic glass panels. Ben Niamthet, Associate Principal at Burkett Design, says the building was formally split into two halves, shearing down the middle of the pyramid to provide an opportunity for guests to locate themselves within the landscape of the gardens, and affording views to an adjacent historic fountain. The gap was clad with custom-made electrochromic panels that operate in coordination with rooftop light monitoring system to control daylight in the exhibition space below. Niamthet attributes this feature as one of the most successful aspects of the project. "It created a challenge, he said. "Not just an aesthetic challenge, but a structural engineering challenge." Niamthet said this challenge was met by a highly collaborative design process with StudioNYL's Skins Group—a team of facade designing structural engineers. The facade construction doubles as both a wall and a roof, and is technically understood as an open joint roof-mounted rainscreen system. The unique assembly is one of the first of it's kind in the world. A primary steel structure of 18" diameter HSS tubes provide the basis for a layer of plywood sheathing that forms the building's iconic tent-like structure. A secondary layer of structural thermal isolator standoffs set at 2-feet-on-center support for two layers of rigid insulation totaling 5-inches. This outboard insulation layer is protected by a gypsum cover board and a UV-resistant moisture barrier. A tertiary layer of cladding subframing systems provides standoffs for the final layer of hexagonal-shaped fiber cement panels. Will Babbington, principal at StudioNYL, calls the project one of the most iconic projects the facade engineering firm has completed: "The nice thing with all of these layers affords the tolerance that is required for what ended up being a very fast tracked project." To manage increased UV exposure from a slanted rooftop orientation, Cosella-Dörken's DELTA®-FASSADE S product was specified because of its properties as a highly stabilized material against damage from UV exposure. The product is designed for use in cladding systems that have open joints of up to 2-inches wide which expose up to 40-percent of the entire facade surface. Marrying the hexagonal grid with the buildings pyramidal form produced inherent alignment challenges for the design team. Babbington recounts, "we rotated that pattern well into the double digits... maybe even triple digits... [at] times trying to find a way to minimize tiny slivers of fiber cement board which were too small for standard fastening methods." StudioNYL says the greatest challenge associated from detailing a rainscreen on a sloped surface is the reduction of a natural "stack effect" ventilation—a performance requirement of typical open joint rainscreens. Babbington said the problem required research into fluid dynamics which accounted for specific environmental factors of the system. A digital model was able to conclude that the gap between the fiber cement panels and the exterior wall construction heats up enough to provide an efficient upward airflow. This—despite the slope of the pyramid's walls—promoted a passive method for circulating air in the manner rainscreens are designed to perform. The fluid dynamics model specifically accounted for solar orientation of the facade surfaces, local climate data, and the dark coloration of the Swisspearl panels. The project team is awaiting data from this high-performance building to evaluate the efficiency of the Science Pyramid's construction assemblies and systems, which have now been in operation for almost two years.
Posts tagged with "BIPV":
The Techstyle Haus is an 800 square foot fabric house that uses 90% less energy thanks to a high performance double skin membrane with integrated PV.Co-founded by Colin Touhey, Todd Dalland, and Robert Lerner, Pvilion is pioneering the design, engineering, fabrication, and installation of flexible solar solutions. For their 2014 Solar Decathlon project—a collaboration between RISD, Brown University, and University of Applied Sciences Erfurt (Germany)—Pvilion provided engineering consulting services on the structural design and membrane roof system. The project team questioned if a membrane roof house could be designed to meet strict passive house energy codes. The answer was a resounding yes—what came to be known as the Techstyle Haus is currently the only fabric structure that meets passive house standards, producing 50% more energy than it consumes. The house was originally constructed in Providence and then disassembled, placed in crates, and shipped to France for relatively easy re-assembly at Versailles. Currently, the Techstyle Haus resides at Domaine de Boisbuchet, the site of an annual art and design workshop, where it serves as a living laboratory and teaching tool as well as student housing. An in-depth video of the design can be viewed here. Colin Touhey, co-founder of Pvilion, said this project is a proof of concept for their flexible, scalable solar solutions. “Given the curvature of the form, the building produces more energy than flat or angled solar arrays.” Techstyle Haus was designed in concept to embrace a double skin tectonic. It’s PV modules are encapsulated in a thin sheet of plastic allowing for a lightweight assembly of shallow curves and folded surfaces. PV’s are typically very labor intensive as each 3’x5’ panel has to be individually wired. Touhey says by eliminating a significant amount of the “stuff” that goes into a traditional solar array can offer design flexibility along with cost savings: "the more that can be integrated into the off-site fabrication process, the cheaper and more effective the system will be. Also, we have found if you eliminate the frames from a PV, if you eliminate the glass from the PV, and if you laminate the PV into a light material, you can ship more of it in one container. All of these variables add up on a very large scale." Building Integrated Photovolatics (BIPV) have become an increasingly significant topic within the advanced building systems design and construction community. Rather than treating PV as an additive system requiring a separate metal support structure superimposed on a building’s roof, BIPV is an evolving practice of incorporating custom solar technology into the constructional logic of a structure. Often, BIPV projects see cost savings through the replacement of roofing tiles or other building elements with photovoltaic panels. The 2014 solar decathlon was held in Versailles, France, and included 20 prototype structures from 16 different countries. From these projects, 11 prominently utilized BIPV strategies. In addition to Pvilion’s flexible solar fabric, other approaches included cantilevered lightweight shading elements, solar-integrated glazing, a colorful lightweight PV roof, and numerous roof-mounted configurations. In a statistical analysis conducted by a team of researchers at Jaume I University (Castillo, Spain), and published by Advanced Building Skins GmbH, the Techstyle Haus was rated as one of the “most pleasurable BIPV solutions.” Robert Lerner, a co-founder of Pvilion, explains the value of lightweight solar fabric for large commercial applications: “we developed a way to put photovoltaic sheets as a secondary membrane onto a primary membrane. the primary roof skin will almost always be a costly, durable product. Consider a 50 year Teflon-coated glass fabric under very high pre-stress for long spans. Our lightweight membrane can be replaced in 20 years if necessary without affecting the roof below it." Half of Pvilion’s projects are facade-related while half are completely unrelated lightweight temporary and permanent structures—from outdoor clothing apparel to parking canopies and infrastructural projects. Touhey says their goal is to take the Techstyle Haus’ system—an interior skin, exterior membrane, insulation, PV, and wiring – and scale it up to a significantly larger context. Upcoming projects include the Artist for Humanity Headquarters in Boston—a renovation and expansion of and existing building into a structure 5 times as large as the original. Once complete, it will be the first net energy positive large commercial project on the East Coast. The building will feature a solar wrapper that doubly functions as a passive shading element integrated with flexible monocrystalline photovoltaic cells. Other applications include flexible installations on perforated aluminum and warped steel panels, both with free-form perimeters and curved surfaces. Lerner says this is where flexible solar technology shines, “This indicates the freedom of design that is possible while incorporating conventional facade materials."
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Research into flexible active skins opens up new BIPV possibilitiesAs building integrated photovoltaic (BIPV) technology becomes more advanced, architects are getting involved in how new systems affect not only a building’s performance, but also its appearance. “The photovoltaic industry was until now largely developed by engineers,” said Daniel Martín Ferrero, a Madrid-based architect researching solar design. “The architect must enter the industry to develop their integration into the urban scene.” Ferrero has launched a new company named The New Solar Architecture with a goal of bringing a higher level of design to solar energy-producing facades. “I try to convey the idea that the generation of clean energy can be part of the beauty of its major consumer, the city,” said Ferrero. The company’s goal is to design an active skin whose solar modules are composed of flexible material, which would facilitate a broader range of BIPV design possibilities for architects. Now in the conceptual design and construction phase, his Free Form Solar Powered hexagonal modules are manufactured with photovoltaic laminated glass. Along with the modules, Ferrero has developed details for potential construction systems that would integrate them, including ventilated facades, curtain walls, and monolayer structures. The hexagonal, honeycomb-like skins could have far-reaching implications for BIPV design in projects as small as parking structures or as large as Olympic stadiums. Watch the video below to see the fabrication process behind BIPV glass: