ACHIEVING THE IDEAL: Quiet Space and Optimal Power Quality
Part I -- Acoustics
June 01, 2003
Appeared in ProSound News
Professional work environments benefit from adherence to professional standards, whether in a high-tech manufacturing facility or a recording studio. The two major areas of concern in the studio are acoustics and electrical power. Recording studios require space free of noise and vibration intrusion from adjacent activities and mechanical, electrical and plumbing (MEP) systems.
Noise and vibration come from two main sources: adjacent activities, both within the building and outside, and from the MEP systems. Intrusion of noise and vibration from adjacent activities can be minimized through proper space planning. Locating the studio at the interior of the building, away from mechanical and electrical rooms, other support spaces, and high traffic work or public spaces is one approach. Another involves the architect/acoustical consultant’s use of effective acoustic design and materials, and the MEP consultant’s use of sound dampening techniques in the mechanical ductwork.
The mechanical system is the most common source of intrusive noise and vibration, which are carried by supply and return ductwork throughout the building. The selection and location of the proper mechanical system is essential to minimize noise. A roof-mounted constant volume system is the quietest type of unit, followed in order by air handlers, fan coils and heat pumps. However, a central air handling unit also requires the most physical space of the three types of units. Space often is at a premium in facilities housing recording studios, so it may be necessary to specify several smaller “package” air handling units, small heat pumps or fan coils.
In addition, because the recording studio may run 24 hours, unlike other spaces in the facility, it is not economical to run the central air handling unit around the clock. Rather, it makes sense to zone the building using several smaller units.
Location and positioning
Proper location and positioning of the mechanical unit(s) is also essential to minimize noise at the source. The roof is the optimal location for a central air handling unit, with supply ductwork run laterally before it is brought down through the roof into the building. Package units, heat pumps and fan coils should never be installed within or directly above or below the recording studio(s).
Another method of dampening noise is to reduce the speed of the air flowing through the ducts by sizing the ductwork somewhat larger than is typical for, say, an office building. Noise also can be controlled downstream of the mechanical units using fiberglass or acoustical foam duct lining. Often “silencers” are used -- sections of air duct fabricated of thickened walls and a fiberglass-filled metal lining and/or another type of sound baffle – both close to the mechanical unit itself and at strategic points throughout the system.
Unexpected noise sources
The plumbing and electrical systems also are sources of intrusive noise and vibration. It is essential to keep water pipes out of the recording studio, not only to avoid water damage in the event of a burst pipe, but also because of the noise they generate -- especially those used intermittently, such as sanitary pipes and storm drain pipes. In adjacent areas, piping should be hung using hangers with isolators.
Often, noise comes from unexpected sources, including power outlets, conduit and lighting fixtures. Therefore, care must be taken in selection, placement and routing, and proper acoustic sealants and gasket materials should be used.
Achieving the ideal noise-free recording studio requires solutions to a host of challenges. A team approach among owner, architect/acoustical consultant and MEP engineer from the planning phase through completion is key to providing cost-effective approaches that enable a recording studio to generate the quality recordings – and profits – required to succeed in this highly competitive and demanding industry.
Hisham Barakat is a Vice President, Sports and Entertainment Group, with the Los Angeles office of Syska Hennessy Group (www.syska.com), a leading consulting, engineering, technology and construction firm.