Biomedical Engineering Reference
In-Depth Information
the building or its occupants make it a poten-
tial target. By first assessing the vulnerabilities
of facilities, building owners and managers can
address physical security in an effective manner.
While the identification and resolution of building
vulnerabilities will be specific to each building,
some physical security actions are applicable to
many building types. These include:
Relocate outdoor air intake vents
. Relocating
accessible air intakes to a publicly inac-
cessible location is preferable. Ideally, the
intake should be located on a secure roof
or high sidewall. The lowest edge of the
outdoor air intakes should be placed at the
highest feasible level above the ground or
above any nearby accessible level (i.e., adja-
cent retaining walls, loading docks, handrail)
(Figure C.1). These measures are also bene-
ficial in limiting the inadvertent introduction
of other types of contaminants, such as land-
scaping chemicals, into the building.
Extend outdoor air intakes
. If relocation
of outdoor air intakes is not feasible,
intake extensions can be constructed without
creating adverse effects on HVAC perfor-
mance. Depending upon budget, time, or
the perceived threat, the intake extensions
may be temporary or constructed in a
permanent, architecturally compatible design
(Figure C.2). The goal is to minimize public
accessibility. In general, this means
the higher
the extensions, the better
—as long as other
design constraints (excessive pressure loss,
dynamic and static loads on structure) are
appropriately considered (Figure C.3). An
extension height of 12 feet (3.7m) will place
∗
1.
Prevent access to outdoor air intakes
. One
of the most important steps in protecting a
building's indoor environment is the secu-
rity of the outdoor air intakes. Outdoor air
enters the building through these intakes and
is distributed throughout the building by the
HVAC system. Introducing CBR agents into
the outdoor air intakes allows a terrorist to use
the HVAC system as a means of dispersing
the agent throughout a building. Publicly
accessible outdoor air intakes located at or
below ground level are at most risk—due
partly to their accessibility (which also makes
visual or audible identification easier) and
partly because most CBR agent releases near
a building will be close to the ground and
may remain there. Securing the outdoor air
intakes is a critical line of defense in limiting
an external CBR attack on a building.
Figure C.1
