Tonal noise in heating, ventilation, and air-conditioning equipment in commercial and residential buildings

Abstract

All heating, ventilation, and air-conditioning (HVAC) equipment that moves air or compresses refrigerant produces noise with tonal content. The challenge for the equipment manufacturer and building designer is to make sure that this tonal noise is isolated from the occupied spaces in a building. This paper provides an overview of the tonal content in airborne and structureborne sound produced by heating, cooling, and ventilation equipment. Examples of the tonal noise in HVAC components and packaged equipment will be presented. The challenge to manufacturers in measuring and rating equipment sound will also be covered. An overview of methods for testing and rating HVAC equipment sound will be presented, with emphasis on the uncertainty in characterizing the tonal content.