Mimes pretend to be trapped behind glass; a mime behind sound insulating film from Kuraray would also need to pretend they cannot hear. This acoustic glass attribute has been achieved with PVB Acoustic film from Kuraray. Dubbed Trosifol SC (Sound Control) the technology was developed in response to a developer who enticed potential tenants for its Pierhouse and 1 Hotel development with striking views of New York Harbor and the park; yet this also meant the residential building would be vulnerable to urban noise.
“Our primary design intent was to minimize the noise while delivering maximum light and view,” says Dennis Vermeulen, director at Marvel Architects. Vermeulen had a good feel for the area and knew what would be required of the façade: “For the units facing the East River and the Brooklyn Bridge Park, noise comes from park activities and live music performances, as well as from helicopters flying to and from Lower Manhattan. On the Brooklyn side of the project, we had to contend with the Brooklyn Queens Expressway traffic noise and industrial noise coming from the adjacent Brooklyn neighborhood dubbed DUMBO (an acronym for Down Under the Manhattan Bridge Overpass).”
In this case, requirements for noise reduction are based on Outside Inside Transmission Class (OITC), a single number rating intended for windows and doors that are subjected to transportation noises, such as aircraft, automobiles and trains, and other low- to mid-frequency noise. The OITC rating is calculated based on a frequency range of 80 Hz to 4 kHz. The team looked to Lance Bischoff, senior technical director–acoustics, noise and vibration at AKRF, to meet the OITC goals on Pierhouse.
After assessing project-specific noise studies, AKRF determined that the sound attenuation would have to be one of the top-performing attributes of the glazing—with solar heat gain a close second. “The residential developer and the hotel owner both had very high acoustical design standards, which were more stringent than noise goals for typical e-designation work. The combination of loud area and low noise goals for both residential and hotel placed a high attenuation performance goal for the windows of this project.”
The architects initially investigated double-laminated insulating glass on either side of an air space; however, by deploying Trosifol SC, the team was able to specify monolithic glass on the outside of the air gap and laminated glass on the inside. This way, the air space adds to both sound and heat control properties of the panels. Compared to laminated glass with standard PVB film, an improvement of up to 3 dB in the sound insulation value can be achieved with the use of Trosifol SC. It offers 88% light transmittance and a low yellowness index, satisfies the requirements of EN 14449 and EN ISO 12543-4, and assures a long service life. The mono-layer construction is simpler for laminators to process and deliver compared to multi-layered alternatives and promises joint development of application-specific formulations in order to meet unique requirements of every major urban hub.