School is out for the summer at Radford University, and the project to replace the air-supported fabric roof, nicknamed “the bubble” at the Dedmon Athletic Center, is starting to pop.

While students are away, work is beginning on the project to install a new energy-efficient, tensile fabric, steel-supported truss roof on the Dedmon Center, the first installation of Birdair’s new Tensotherm™ with Nanogel® aerogel product. The new roof replaces the original air-supported fabric roof, which was installed in 1980. It will enclose the sports arena’s entire 52,000 square-foot roof and will be completed by November 2008, just in time for the NCAA basketball season opener.

The Challenge
“The original Birdair roof of the Dedmon athletic facility had performed beyond its expectations and well exceeded its lifespan. We made the decision to go with Birdair again a couple years ago when we foresaw the need to replace it soon,” says Roy Seville, Radford University’s director of facilities planning and construction. "When that time came, we were extremely pleased to learn that Birdair’s new Tensotherm with Nanogel product would meet our needs for greater energy efficiency, moisture resistance and sound dampening as well.

The difference is Nanogel aerogel
Nanogel aerogel has an air content of 95 percent, making it the lightest solid material in the world. Its nano-porous structure significantly reduces conduction and convection of heat, making it extremely energy-efficient. The Nanogel aerogel produced by Cabot is also extremely durable and water and fade resistant.

Birdair's Tensotherm with Nanogel consists of an aerogel fabric layer sandwiched between two layers of Birdair structural PTFE fabric, creating an insulated composite that was not possible before the advent of the Nanogel light transmissive fabric inner-layer. The fabric is less than 50mm thick, yet it doubles the original roof's thermal insulation performance with a value of R-12 and natural light transmission value of 3.5 percent. The advanced material also offers maximum moisture control and superior sound insulation. These permanent performance features will not change over time, matching the long-term efficacy of the PTFE membrane.

The Dedmon Center plans also call for upgrading the facility's heating and cooling systems once the new roof goes up. The performance of the nanogel inside the Tensotherm will contribute significantly to cost savings in mechanical systems as well as long term operational cost reductions due to increased energy efficiency.

The sky's the limit
Tensotherm with Nanogel represents a new frontier for tensile architecture. The potential seems unlimited for this new fabric, reaching well beyond roof structures, especially in hot and humid climates. The Dedmon Athletic Center project showcases how beauty and durability can combine with energy efficiency to create a daylighting solution that balances the design and performance required by today's savvy architects and building owners.