Kalwall teaches school lessons in sustainability

 

Increasingly today, independent schools are embracing sustainability as part of their educational mission. Good stewardship of the environment is becoming as fundamental to the learning experience as are teamwork, respect for others, athletics, and the curriculum itself. Creating facilities that are not only sustainable but LEED® certified, however, is a challenge – one that Far Hills Country Day School has taken on with enthusiasm and New York-based architects Butler Rogers Baskett (BRB) have pursued with success.

That challenge is especially evident in the decision surrounding the design of Far Hills' new athletic facility, scheduled to open in time for the 2008-2009 school year. The project – a component of the School's 10-year "Pathways to Excellence" campaign of sustainable campus-wide modernization and expansion – serves as a compelling case study of the complex balancing of function, location, and LEED requirements. For this new project and for the site work, the School is pursuing LEED NC 2.2 certification.

New Gymnasium, Sustainable Design: Two features of sustainability in general and LEED in particular – high energy performance and maximum natural light – present challenges in the design of gymnasiums. At Far Hills, the former was made still more complex by the considerable variation in demand.

Energy performance: Below the frost level, the earth maintains a relatively constant 55 degrees. Thus, BRB elected to dig a portion of the gymnasium into a hillside, reducing its visual mass while increasing its thermal mass. The building will naturally self-regulate to a considerable extent year-round, lowering the School's operating costs. The architects also specified a "cool roof," which further reduces the cooling load and the "heat island" effect on the gymnasium's surrounding microclimate.

On conventional projects, the mechanical engineer typically takes two factors, peak load and peak demand, into account in determining the appropriate size of equipment. At Far Hills, however, the wide range in the numbers of people using the facility, their relative level of activity, and the gymnasium's year-round use all required more sophisticated calculations and planning. The scheme for the building's HVAC system included three split system air-handling units, seven stages of cooling, and borrowed capacity from an existing adjacent unit. The result is a 35.8 percent reduction in the gymnasium's overall cooling load.

Other strategies include demand control ventilation, carbon dioxide monitoring, the use of exhaust air to pre-cool the condensers, instantaneous hot water heating, and pre-heating combustion air with exhaust air. The system overall outperforms the current energy code by 35.8 percent and earns the project 8 of a possible 10 LEED energy points.

Natural light: The more natural light, the better for energy efficiency and well-being; on the other hand, the more natural light, the more glare on the glossy playing court surface. Most gymnasiums have glass windows high on one or more walls, which tend to defeat both energy efficiency and glare reduction.

The architects' solution is a system of translucent wall panels, manufactured by Kalwall Corporation; while these have a lower level of light transmission than glass, the design called for coverage of a very large wall area, greatly increasing the amount of daylight. Kalwall has been used in gymnasiums for more than 50 years, but not often to the extent proposed by BRB. To allay the concerns of Far Hills' leadership and athletic director, the architects conducted telephone interviews with the athletic director at Teesside University, in the U.K., where the application of Kalwall was similar to that proposed for Far Hills. They also arranged a trip to the New York Hall of Science, on the site of the 1964 World's Fair, which has Kalwall panels on the roof and two walls. And finally, they challenged the Far Hills athletic director to test the material's durability by hurling lacrosse balls at a mock-up. The system proved as durable as it was glare-free and, as an added benefit, cost less per square foot than the single-wythe masonry wall system used for the solid walls.

To further reduce glare (also noise and the cost of maintenance and upkeep) BRB specified flooring consisting of a pad of recycled rubber tires adhered to the concrete slab, with a self-leveling polyurethane coating poured on top.

LEED is not the only pathway to sustainability; for some projects and institutions, other gestures and measures may be more suitable. But LEED has distinct advantages: it encourages innovation in both design and use; the required commissioning ensures that the intended benefits are being delivered; and it is a powerful and public statement of a school's commitment to sustainability.

Far Hills Country Day School Gymnasium
Far Hills, NJ
Architect: Butler Rogers Baskett
Photos: Woodruff/Brown Architectural Photography

Kalwall Specifications:
Walls: 4,818 square feet (447.6 square meters)
U-value: 0.10 Btu/hr/ft²/°F (0.57 W/m²K) thermally broken
Light Transmission: 10%
Exterior Color: .070 Crystal SW
Interior Color: .045 Crystal S-171

Skylights: 216 square feet (20.1 square meters)
U-value: 0.10 Btu/hr/ft²/°F (0.57 W/m²K) thermally broken
Light Transmission: 10%
Exterior Color: .070 Crystal SW
Interior Color: .045 Crystal S-171

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