Supplying Vacuum to Cleanrooms
Local vacuum networks save space while reducing energy consumption and heat load.
V.P. – Marketing
Essex, Conn. Acentral principle in the design of cleanrooms and bio- containment suites is the need to minimize capital, oper- ating, and energy costs while creating an efficient, high performance space. Clearly, this is a core objective in the
Positive and negative pressure environments
design of any lab space, but when the space must be effectively
isolated from the remainder of the facility, and costs several
hundred dollars per square foot, the design challenge is only
magnified. One way to achieve space efficiency in such critical
areas is to locate most utilities outside the controlled environ-
ment, but this can pose problems in the case of the scientific
vacuum utility used in biological, chemical, and materials labs.
The negative pressure environment of a biosafety lab (BSL) is
designed to contain biological materials; a central vacuum system
that sucks potentially hazardous materials out of the lab and
transfers them elsewhere violates the foremost design objective for
such spaces. Biosafety laboratories needing only one or two aspiration workstations can always use an integrated vacuum aspiration stations (Fig. 1) within or adjacent to the biosafety cabinet
(BSC) and exhausted through the cabinet’s HEPA filters. Multiple
vacuum workstations within the biocontainment space, however,
can consume very expensive square footage, complicate exhaust
management and add heat load on the HVAC system.
In planning a cleanroom, on the other hand, locating
vacuum pumps outside the room is desirable—both for the
space-conserving benefits in the cleanroom and to minimize
the risk that pump exhaust may add to the room’s particulate
load. Vacuum control then becomes the challenge; the pump
is outside the room and vacuum control is needed inside. You
could handle that problem by installing the pumps inside
the cleanroom, and exhausting pumps to the outside. That
achieves the control objective, but once again at the cost of the
pumps occupying precious space and generating heat load.
Both of these design challenges—supplying vacuum for the
positive pressure environment of the cleanroom and negative
pressure environment of the biosafety lab—can be addressed
by relying on local vacuum networks.
Modular vacuum networks
Local vacuum networks are powered by a quiet, compact, oil-free
vacuum pump that can be installed inside or outside the lab.
Vacuum is delivered to multiple users in the lab space with easy-to-install tubing and specialized vacuum ports (turrets) designed
to reduce the “cross-talk” that is typical between users of traditional vacuum systems. These flexible, modular networks can be
used to supply vacuum to an entire facility of adjacent work areas,
or installed only in individual rooms, including mobile labs or
leased space. Further, vacuum available on the local networks can
be two orders of magnitude deeper than that available through
conventional central systems, extending the range of applications
that can be supported without dedicated pumps.
In the biocontainment suite, the dry pump would be installed
within the controlled space in support of the containment
objective, supplying vacuum to as few as two or as many as 16
workstations. Each workstation is equipped with 0.2 micron
sterile filters to keep bio-aerosols out of the vacuum lines. Since
all flow within the vacuum network moves toward the single
vacuum pump, control of exhaust is much simpler than with
multiple pumps; the single exhaust line leaves the room through
the HEPA filters that manage all ambient airflow. Locating
the pump within the contained space, and HEPA-filtering the
exhaust, provide extra protection against aerosol release beyond
that offered by the workstation filters. The pump generates only
about as much heat as a couple of light bulbs, minimizing heat
gain that needs to be managed for energy efficiency and comfort. Exceptionally long maintenance cycles—years in normal
use—virtually eliminate need for service access.
In the cleanroom, the objective is to minimize the release
of contaminating particulates. In this instance, the network
pump would be installed (and exhausted) outside of the controlled space, so no particulates that may be drawn into the
vacuum system are recirculated into the room. The network
is plumbed from the pump to the interior, where individual
workstations may be optionally equipped with electronic controls that can provide unique, programmable vacuum conditions to each workstation (Fig. 2). And once again, the single,
external pump saves precious space within the expensive facility, without sacrificing the control that might otherwise call for
a dedicated pump inside the cleanroom.
Modular local vacuum networks offer a modern means to
deliver isolated, controlled vacuum economically to critical environments—including to modular and mobile lab—while saving
space, energy, and heat load. The many advantages of local
vacuum networks make them an ideal choice when designing
vacuum utilities for biocontainment suites and cleanrooms.
Peter Coffey is Vice President – Marketing for
VACUUBRAND Inc. He can be contacted at
Fig. 1: An aspiration
station with integrated
vacuum supply can
support one or two
operators in a biosafety lab.
Fig. 2: An automated
vacuum pump in a
remote closet provides
in the lab, with the
option of programmable control at each