Designers are often asked to accommodate
a specific piece of either existing or new equipment. This equipment can include NMR systems, electron microscopes, telescopes or certain nano-electrical or opto-electrical systems.
“In the case of accommodating a specific
piece of existing equipment, we must work
closely with the end-user and tool manufacturer to establish the requirements, and work with
the end-user to define what may come next in
the evolution of their research,” says Tinsley.
“In the case of accommodating new equipment, it’s largely a matter of defining, during
programming, the type of research the building
is designed to accommodate, and the equipment requirements likely to support those
research needs,” continues Tinsley.
The type of vibration isolation a piece of
sensitive equipment needs is dependent on the
equipment’s vibration sensitivity and on the
vibration environment at its location. Many
isolation systems are currently available from
a number of vendors, such as Kinetic Systems,
Minus K and Grainger. These systems include
small isolation platforms for desktop equipment
and optical tables consisting of very stiff tops
supported on air-spring legs. Some equipment—NMRs and electron microscopes—can
be obtained with isolation systems provided by
For most large pieces of equipment, simple
isolation systems consisting of rubber pads
or other resilient materials, such as steel coil
springs and other vibration isolators, suffice.
A well-designed isolation system can
reduce floor vibrations by a factor of 10 or
more. However, the tricky part, according to
Zapfe, is the sensitive equipment probably has
its own isolation system which needs to be
taken into account. “The most common way
to do this is to employ a massive platform to
support the equipment,” says Zapfe. The mass
separates the isolation systems, allowing them
both to work effectively.
If low-vibration islands are used, designers
must plan on more space. “For example, the
isolators and massive platform will likely be
housed in a pit to maintain the floor height,”
says Zapfe. And, if acoustical isolation is needed, this requires special construction like double grout-filled concrete masonry walls.
Overall, active vibration-isolation systems
have matured over the past five years. “Active
systems are attractive because they obviate the
need for the massive platform,” says Zapfe.
Active systems are suitably stiff, with little
chance of adverse reaction with the equipment’s
Challenges of vibration control
Essentially, the greatest challenge in vibration control design is providing lower vibration
environments. Some researchers use two, three
or more stages of isolation. The question then
becomes: How can this be done economically?
According to Zapfe, the locations of building
systems are important to answer this question.
“The farther sensitive areas are from mechanical
rooms, the better,” says Zapfe. And, properly
designed supplement isolation for sensitive
equipment can make a difference in the base
vibration levels. With a strong plan, both cost
and space can be viewed economically.
Another challenge in vibration control design
of labs and facilities is the schedule. Programming may begin for a project years before the
equipment is eventually purchased, installed
and validated, making equipment integration
during the duration “a moving target”, according
to Tinsley, requiring that lab planning presumptions made during programming be retested
during each phase of the project.
To alleviate this issue, a ground rule, according to Tinsley, is to establish a stakeholders
committee and make sound decisions with
everyone onboard from programming through
equipment validation. Having an experienced
estimating group onboard early to guide the
process of defining requirements and costs is
essential to project success.
Yet another key challenge on most vibration
control facility projects is the integration of
control strategies with structural, architectural
and MEP elements. “Some of the vibration and
EMI controls are seemingly small construction
details that are critical to performance,” says
Pridham. “Diligent management of quality
control during construction is essential to
The desire for some owners to “future
proof” facilities against future unknown sourc-
es is another challenge, as well as the availability
and quality of information on vibration and
EMI sources and technology implemented in
“The best way for designers to face these
challenges is accept there are EMI/vibration
challenges in every facility and resolve to incorporate controls and resiliency into the design
to address challenges foreseen and unforeseen,”
In the end, the most successful projects
are those where experienced consultants are
brought onboard early.
With tooling increasing in complexity, the
lab or facility is required to keep pace. Consulting in this area is an evolutionary process,
says Tinsley, with new ideas coming to the
forefront to challenge old ways of thinking
and old strategies.
Future of vibration control design
More data will essentially lead to more definition of the market; and time will prove some
strategies better than others, or more economical or easier to construct.
From a design perspective, Novus Environmental envisions the assembly of a library of
cataloged low-vibration/low-EMI components,
materials and design elements that can be referenced for implementation on projects. “Further
improvements to integration of these elements
with BIM lead to optimization and value engineering to control costs, better visualization of
the vibration and EMI environments and for
planning of shelled spaces,” says Pridham.
In the future there will also likely come a
time when low-vibration islands are designed
with two stages of isolation, according to Zapfe.
However, that’s a ways off. “Such a design will
be challenging because the low-acoustical noise
requirements that would presumably come
along with it,” says Zapfe.
From a vendor and end-user perspective,
Novus Environmental envisions the integration
of active controls into toolsets to address both
vibration and EMI becoming more popular.
“With increasingly collaborative research environments we foresee tool sharing becoming
more prevalent, enabling the best tools in the
best environments to be shared amongst several research organizations,” says Scott. This,
in turn, will lead to the development of remote
research and toolset operational capabilities
though virtual research environments.
Riddick & Polk Halls renovations and additions for
vibration control at the North Carolina State Univ.
Image: Willett Photography