Acoustic Measurements of Duct and Duct Liner Materials

Air movement within buildings is typically achieved by a network of ducts connecting to building Heating-Ventilation-Air Conditioning (HVAC) systems delivering air to various spaces within a building. Duct insulation is an important component of these systems providing both thermal and acoustic insulation to aid energy efficiency, prevent condensation, and reduce noise. When specifying insulation, professionals should identify, along with moisture management, the parameters of importance for both thermal and acoustic performance. While thermal performance is usually the primary driver for duct insulation specifications, noise control is also a critical feature to be considered. Sound generated by HVAC and air movement, which can be carried great distances through the ducts without proper attenuation, can be a nuisance. Additionally, air ducts connecting two rooms may freely propagate sound between rooms in the absence of insulation creating privacy concerns. Therefore, the data used to select materials used to treat the ducts is critical to the overall building noise control design. This study compares methods to identify the acoustic performance of acoustic ducts and linings.