Window design techniques for sound attentuation

Abstract

Excellent sound attenuation can be obtained with high performance, double window construction methods by optimizing glass selection and addressing basic design and construction details. With careful attention to manufacturing standards, DeVAC Series ♯600 thermo‐barrier acoustical windows have STCs in the 37–39 range, glazed with common 1/8‐in. window glass at the exterior and interior. The design provides an air space separation of 2‐in. between inner and outer lites. Isolation and sealing for thermal performance increases the acoustical performance without using laminated glass. Noise penetration is reduced by achieving a low rate of air infiltration with dense, double weatherstripping, and covering drain holes with valve flaps to exhaust water buildup and eliminate air path channels. Glazing with heavier, unequal thicknesses of glass (maximum 1/4‐in.) increases STC to 48 dB. Further options that accept glass up to 1/2‐in. thick, and increase the air space separation to as much as 8‐in., enable incremental improvements in STC to a currently tested 56 dB. The windows install in new construction with standard installation methods and, with optional trim accessories, adapt to existing openings for retrofit. Acoustical performance of available glazing and frame configurations are documented by sound loss test reports. Case history applications review both new construction and replacement projects requiring sound control windows which are operable for emergency ventilation or life safety, thereby addressing points of concern for residential, lodging, and educational facilities. Field testing by independent acoustical consultants confirms that the acoustical performance of installed windows meet project specifications.