On ASHRAE RP-1919: Effect of duct size and aspect ratio on flow noise

ASHRAE has funded research that has augmented the understanding of sound and vibration in architectural acoustics since the 1960s. Many of the results from these research projects can still be found in handbooks and reference materials for building design. An ongoing research project is Research Project 1919; the goal of RP-1919 is to investigate the regenerated noise and breakout noise of elbow fittings, eventually resulting in an algorithm for a variety of flow rates that considers a duct’s size and aspect ratio. This algorithm is intended for more accurate noise prediction of elbow fittings, to better inform building design. The desired outcomes for this project necessitate modified test methods, including variations on several intensity scanning methods, and some unique equipment. Initial investigations have been undertaken to ensure that the data collection methods produce a reliable representation of the conditions under investigation. This presentation will cover some testing methods, apparatus, and trends from the initial investigation for RP-1919.