Notes that sound quality in office and other occupied spaces has been of continuing interest since the 1950s. Existing assessment methods do not account adequately for the low-frequency background sound (less than 250 Hz) in particular low-frequency rumble produced by operating HVAC systems. Discusses the results of research in which more than 75 HVAC noise samples were collected, normalised and categorised in terms of sound quality. Proposes a modified set of room sound quality curves.

KEYWORDS: Noise, heating, ventilation, air conditioning, research