The 50 by 75 ft Meadow Structure is the first tensile structure to incorporate thin-film photovoltaic panels into fiberglass membranes that have been coated with polytetrafluoroethylene. © Marpillero Pollak Architects
Three engaging environmental structures at the Staten Island Children’s Museum will delight young visitors and their parents with a whimsical approach to practical lessons in sustainable energy.
September 11, 2012—Alternative energy will be child’s play at the Staten Island Children’s Museum with the addition of three new environmental structures inspired by the museum’s maritime location and history. Situated at Sailors’ Snug Harbor, the former site of a sailors’ rest home, the popular museum has added a solar-powered outdoor gathering space, a wind “scoop,” and a wind turbine.
The structures evolved from the museum board of directors’ original plan to construct a tent for outdoor events and repair a leaking skylight. But when Marpillero Pollak Architects, of New York City, was engaged for the project, they saw an opportunity to capitalize on the sailing theme to teach children about sustainability.
“As we began to think through design, we decided to engage children in an awareness that they are in a maritime environment, and we delved into the language of sailboats and sails,” explains Sandro Marpillero, FAIA, a principal and founder of the firm. “We saw this as an opportunity for children to access new forms of environmental education, and, in the case of the tent, to create something fun and useful.”
Marpillero’s interpretation of a “tent” is the eye-catching Meadow Structure sited on the lawn near the museum’s main entrance. The graceful open-air tensile structure “represents a series of sails supported by masts,” Marpillero says.
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Cables on the structure’s eastern side are anchored into a concrete mass that engages the soil to resist the loads; cables on the western side are anchored into a solid concrete block. © Birdair, Inc. |
Comprising a series of structural steel pipes supporting a membrane, the 50 by 75 ft Meadow Structure is the first tensile structure to combine fiberglass membranes coated with polytetrafluoroethylene with thin-film photovoltaic panels. At the structure’s northern end, the membrane is conical and accordion-pleated, supported by a 30 ft pipe to create the main entrance.
From the entrance, the membrane swoops in a series of shallow ridges and valleys intended to evoke images of sails on boats. In sunny weather, the membrane serves as a sunshade. In inclement weather, rain or snow melt is funneled off of the canopy, creating small waterfalls around the edges; the runoff drains into surrounding inground wells.
Designing the structural system to accommodate Marpillero’s design required balancing the need for maximum sun exposure, appropriate degree of curvature, and aesthetics, explains Gregory Freeman, P.E., LEED AP, M.ASCE, an associate in the West Hartford, Connecticut, office of the structural engineering firm Weidlinger Associates, Inc., and the firm’s project manager.
“For optimum efficiency, tensile membrane structures require a certain amount of curvature,” Freeman explains, “but we needed some flatness in the membrane to allow for the strips for solar energy collection.” Strips of photovoltaic film are integrated into the membranes, which are angled at 45 degrees and anchored to the ground by cables.
On an average day the structure’s photovoltaic panels collect enough energy to illuminate the pavilion area for evening events. Electrical wiring for thousands of tiny white lights that light the structure is secreted in the steel pipes.
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The scoop rotates to point into the wind, capturing it for use in cooling the building. © Marpillero Pollak Architects |
Cables on the structure’s eastern side are anchored in a concrete mass that engages the soil so that the soil’s weight restrains the load. Cables on the western side are anchored into a solid concrete block to minimize disturbance to nearby tree roots.
The Meadow Structure, which opened in June, exceeded the museum board’s expectations for a mere tent, Freeman notes. “The result is an exhibit that demonstrates solar energy, creates an outdoor event space and is an iconic structure for the area,” he says.
Continuing the maritime sailing theme that inspired the Meadow Structure, Marpillero proposed an equally creative solution to the leaking skylight: replacing it with a wind scoop. “Wind and wind direction have a strong association with sailing,” he explains, “so it fit with the Meadow Structure.”
Weidlinger designed a steel frame to support the turbine that covers the site of the former skylight. The white-coated frame complements the building’s traditional brick exterior.
The scoop rotates to point into the wind, captures it, and provides passive ventilation for the building. The scoop’s colorful, rotating drum extends into the museum exhibit space where it will provide an animated display about wind and wind direction.
Plans for the Meadow Structure and wind scoop were subject to review by the New York Public Buildings Commission. The commission not only approved the plans, it requested a complementary design to replace a second skylight above an elevator. Marpillero complied with a design that replaces the skylight with a vertical axis wind turbine.
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The architects chose to replace a skylight with a nearly silent fiberglass and steel wind turbine. © Marpillero Pollak Architects |
Marpillero collaborated with Weidlinger to fit the turbine into the former mechanical space at the top of the elevator. “After removing the old cupola above the elevator, we created a steel frame to support the turbine and carry the weight to the walls of the elevator shaft,” Freeman says. “We also had to allow for a heavy horizontal load due to the wind and a vibration load as the turbine rotates that the original structure was not designed to accommodate,” he adds.
The lightweight fiberglass and steel turbine is virtually noiseless when in operation. It requires wind speeds of just 2 to 3 m per second (0.04 to 0.06 mph) to start generating energy and will power a new exhibit that demonstrates wind energy.
The wind scoop and turbine are in place, and both exhibits are scheduled to be open to the public by the end of the year.