Mechanical Systems Noise & Vibration Control

Mechanical acoustics focuses on noise and vibration control for all types of moving equipment, ranging from noise control for building systems (such as air conditioning, electrical and plumbing equipment), to specialized design applications, such as targeting the sound quality of appliances and vehicles.


Mechanical room design
Equipment vibration isolation
HVAC rooftop equipment noise control
Air duct design to meet specified noise criteria
Design of floor structure for sensitive equipment
Silencing of fans and other mechanical equipment

Low-Cost Solution for Theater and Studio Noise

A prominent architect had designed a TV studio and adjacent black-box theater for a college in Nevada, without the benefit of any acoustical consultant. In addition to severe impacts from jet fighter overflights, these spaces were immediately plagued by excessive HVAC noise from their respective air handling units, which were located in a common equipment room and had poorly-conceived ductwork sizing and layouts.

The "conventional-but-expensive" solution would have involved either changing out the air handlers for quieter versions and/or adding much new, lined ductwork into what would have been awkward and otherwise bad locations.

The solution: After carefully scrutinizing the as-built design, the NCAC consultant recommended leaving the air handlers in place, and simply swapping which air handler served which of the two rooms. This sufficiently extended the ductwork within the mechanical room so that 7ft. long duct silencers could be installed in the newly-swapped ducts.

The consultant also designed a simple, new, low-velocity arrangement for branch ducts in the studio and theater, by providing additional supply air distribution registers in each room. Suitably low noise levels (NC15-18) resulted in both rooms. The fighter jet noise was mitigated in a similarly simple, yet elegant and economical fashion.