Optimal silencer baffle positioning within an air handling unit

摘要

A stationary bank of rectangular modular sound traps or free-standing sound attenuatingrnparallel baffle “columns” installed within a central station air handling unit (AHU) is arncommon technique for controlling fan noise in a ducted heating, ventilating or airconditioningrn(HVAC) system. Recent design developments by a leading custom AHUrnmanufacturer offer the ability to move these columns within the AHU, so that they can bernpositioned close to a noise source (e.g., a plenum fan) during operation and pushed away inrnorder to allow AHU component inspection and maintenance. While the columns have arnfixed shape and set of features (perforated facing, sound absorbing fill, etc.), this studyrnexamines their sound attenuating performance relative to position variance from thernsource (i.e., fan noise) and the AHU inlet or outlet port at which desired sound levels arernoften specified. The objective, should such column position variance have meaningfulrninfluence on net transmission loss or noise reduction for the AHU, is to estimate optimalrngeometry(ies) than can be tested and subsequently established as guidance for superiorrnAHU noise control design.