Clamping Down on Noise Different Ratings Measure Sound Control, And Knowing the Distinction is Essential By Thomas Renner
Just one year after it opened, the Great Lakes Center for theArts sched- uled a wondrous array of events at the height of the 2019 summer. The Center in Petoskey, Mich. scheduled 31 events for the months of July and August – jazz concerts, movies, the Grand Rapids Symphony, bal- let, violin recitals, a leadership forum, and a closing performance from two of Broadway’s most endearing leading ladies, Andrea McArdle and Donna McKechnie. The diverse lineup of performers aligned perfectly with the mission of the Center. “The mission of the Great Lakes Center for the Arts is to inspire, entertain, and educate with year-round, diverse, world-class programming at affordable ticket prices with robust educational ini- tiatives,” said the Center’s Executive Director, Jill O’Neill. “Visiting artists, intellectual dialogue, movies and film, and educational pro- gramming accompany music, theater, dance, and comedy in bringing exceptional, world-class opportunities to the shores of Lake Michigan.” The architectural design team at TowerPinkster included many unique architectural elements at the 525-seat, 40,000 square foot venue, which sits just steps away from Little Traverse Bay, an offshoot of Lake Michigan. Roots for the project reached back 20 years, when a Community Cultural Plan for Emmet and Charlevoix Counties pri- oritized development of additional cultural facilities and envisioned the addition of a unique performing arts center for the region. After a nine-month design process and 16 months of construction work, the Detroit Symphony Orchestra raised the curtain at the opening gala for the Center. Architectural pieces unique to the region adorned the facility. They in- clude aged copper, Petoskey stone, natural sedimentary rock. “And of course,” lead architect Jason Novotny said, “the beautiful blue waters of Lake Michigan.” Atop the roof of the Center are five acoustical smoke vents that help protect against noise intrusion. The vents, manufactured by The BIL- CO Company, are life safety products that exhaust smoke, heat, and burning gases to improve visibility and protect the building structure. They also allow firefighters to enter the building and contain the fire, and provide safe egress for building occupants. Acoustical smoke vents, however, take on the added quality of control- ling noise. They are used in theaters, concert halls, and in projects near highways, airports, and railroad lines. In a high-performing acoustical environment, Novotny said the design team knew it needed reliable acoustical smoke vents “With the potential for more than 500 visitors for larger events, our team knew we would have a need for a depend- able smoke ventilation system,” Novotny said.
Smoke vents from The BILCO Company sit atop the Great Lakes Center for the Arts in Petoskey, Michigan. The vents protect property and aid firefighters in bringing a fire under control by removing smoke, heat, and gases from a burning building. Photo: Brooksie Productions
Acoustical smoke vents, however, have different ratings that measure how effective they are at limiting noise intrusion. Understanding those ratings is an important part of building design. Rating Acoustical Smoke Vents Ratings for acoustical smoke vents are divided into two groups: Sound Transmission Class (STC) and Outdoor-Indoor Transmission Class (OITC). The difference in the ratings is essential for architects, design- ers, and construction teams to understand. And in the case of the Great Lakes Center and other performance venues, the key rating is OITC. OITC rates the transmission sound between outdoor spaces and indoor spaces in a structure. The OITC rating was developed in 1990 and is typically used to measure sound transmission loss over a frequency range from 80 to 4000 hertz. It is most applicable for measuring the prevention of low frequency exterior sounds such as automotive traffic, construction, and low-flying airplanes through exterior building surfaces. “OITC is the preferred rating when addressing sound insulation from exterior noise – especially when transportation noise sources are Acoustical smoke vents minimize noise infiltration and serve as a critical safety component by allowing smoke, heat, and gases to escape from a building in case of fire. Photo: Brooksie Productions
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may 2020
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