MMM performed a study of this facility, which had a history of noise and vibration problems. The Johnson Center, a four-level, 329,000 SF structure, is the Fairfax Campus student union building with office and classroom spaces, a library, food court, theater, bookstore, bank, and other multipurpose areas.

MMM conducted a walk-through of the center, selecting spaces for a series of sound pressure level testing and visual inspection of the mechanical equipment condition. Measurements were also taken, while air handling units and VAV boxes were systematically deactivated to isolate possible sources of noise and vibration.

Following testing, it was determined that the majority of the problems were coming from a “white noise” generator supplying sound at high volume throughout the building’s public address system. Deactivation of this system reduced sound and vibration levels in most spaces to acceptable levels. Kitchen exhaust fans were also sources of high levels of noise and vibration, especially in spaces immediately below their roof decks, where a lack of mount isolation transmitted vibration into the building structure.

While the air-handling units were not the primary cause of noise and vibration problems at the Johnson Center, recommendations for noted mechanical equipment problems were also provided for corrective action. A final report and construction cost estimate for overall HVAC system modifications to the Johnson Center were provided.