Case study of office noise and vibration annoyance due to building water pumps for HVAC equipment

Abstract

The background noise and vibration in an office workplace area was observed to be excessive. Next to one of the executive offices, as well as an open office space, is a mechanical room that provides heating and cooling to part of the 3-story college campus building. Inside this mechanical room are two hot and two cold water pumps which are part of the HVAC system of the building, as well as two boilers and a pump to a nearby chiller unit. Measurements have determined that these pumps are the main source of noise annoyance. The first task was to determine if the sounds meet the criteria stated in ASHRAE and ANSI standards. The background sound was measured during several occurrences as A-weighted, C-weighted, octave bands, and time recordings to processes narrowband spectrum. RC Mark II and NC levels were calculated from the data, and it was determined that the noise levels are often significantly above the criteria for office spaces. Narrowband and sound recordings indicate tonal acoustic signals generated by the pumps that lead to a higher level of annoyance.