Specifying design noise levels for occupied spaces and units of equipment

Abstract

Acousticians and mechanical engineers specify design noise levels for occupied spaces and systems components (units of equipment). While it is widely accepted that occupied spaces should have a ‘‘balanced’’ noise spectrum, individual units of mechanical, electrical, plumbing, and other building systems equipment do not. Of the three commonly used systems of rating interior noise—noise criteria, room criteria, and noise criteria–balanced curves—only noise criteria lends itself to specifying a maximum noise level for equipment. How can the need for a ‘‘balanced’’ noise environment for people be reconciled with the fact that radiated noise from a fan-powered variable air volume box is predominately in the 125- and 250-Hz octave bands with little sound energy at 1000 Hz and higher? A discussion of the need for a clear standard that is easily understandable to specifiers, clients, manufacturers, and users is undertaken, with suggestions of how to resolve the differing needs of these interacting communities. [See NOISE-CON Proceedings for full paper.]