SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/338693
www.stma.org July 2014 | SportsTurf 31 rolled up and stored away, and the court was played on in the summer as usual. The next project was even more ambi- tious, covering three outdoor tennis courts instead of just one. Since then, Ralph and his associates have been involved in hun- dreds of air-supported structure projects throughout North America and around the world. And today, a three-court ten- nis dome would be considered a relatively small project compared to the very large field house domes that can cover as much as 100,000 square feet of interior space. The Technology An air-supported structure, also known as a dome or a bubble, is a truly unique build- ing system. The entire structure is supported by maintaining a slightly higher air pressure within the fabric membrane than the atmo- spheric pressure outside. This is achieved by an inflation fan constantly introducing fresh air to the interior of the structure. The inflation unit that maintains the internal pressure of the dome is also a fur- nace, keeping the interior of the structure at a comfortable temperature. To ensure that dome remains inflated at all times, a standby inflation system is always ready to take over the inflation requirements, even during a power failure. The interior lighting system is either comprised of fixtures installed on stands around the perimeter or hung from the fabric membrane, or a combination of both. The industry standard for sports lighting is 1,000 watt metal halide fixtures. These fix- tures require a ballast to drive them, which can be placed around the perimeter of the interior, at the base of the light stand poles if applicable, or can be housed in a remote cabinet or other storage building outside of the dome. Several other technologies are being introduced as sports lighting solu- tions, which hopefully will eventually lead to energy savings without sacrificing light levels required for competitive sports. The fabric membrane is manufactured using architectural grade vinyl coated poly- ester fabric, and the pattern is specific to every project to create the shape of the structure. This outer material is backed by a 15 to 20 year prorated warranty, and can be expected to last anywhere from 18 to 25 years before needing to be replaced. A liner fabric is added to the interior of the membrane to improve thermal and acous- tic qualities. Insulation material is placed between the outer structural fabric and the inner liner fabric to maximize energy efficiency, bringing the equivalent insula- tion value from R2 to R10. On medium to large-sized domes, structural cables are installed over top of the fabric membrane to help stabilize it. Main heat and inflation unit and standby inflation fan (Greenville, PA).