Plenum Effect of Ceiling Space on the Assessment of Noise　Level in Occupancy Below

摘要

In recent years the noise criteria requirements of high class accommodationrnhas lead to a demand for the proper assessment of mechanical service noise.rnThis paper presents an ongoing experimental investigation into the plenumrneffect of ceiling space on the calculation of noise levels in occupanciesrnbelow. The effect of the heights and locations of noise sources relative to airrnventilation grilles and to the ceiling were evaluated experimentally. Inrnaddition, the effectiveness of acoustically absorptive materials was alsorntested.