Labconco Cell Logic A2 User Manual page 13

The Inlet Relief Valve located on the top of the
cabinet is designed to draw a maximum of 100
3
CFM (170 m /hr).
Attempting to draw additional room air through
the valve (room air exhaust), can result in
unstable cabinet operation. See Figure 2-4.
If additional room exhaust needs to be drawn
through the exhaust system and/or the exhaust
volume air through the biosafety cabinet must be
maintained when the biosafety cabinet is off to
maintain room pressurization or air change
requirements, install an additional duct and
balancing damper downstream of the cabinet's
damper. This will allow for proper balancing of
the system. See Figure 2-5.
Labconco highly recommends installing an air-tight damper above each biosafety
cabinet when connected to a building exhaust system. See Air-Tight Damper
information on the following pages. The air-tight damper allows for fine adjustment of
the exhaust air volume provided, in order to correctly set the necessary exhaust airflow
for each biosafety cabinet. It also allows the biosafety cabinet to be sealed off from the
building exhaust system, should it become necessary to do so.
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Figure 2-4
Figure 2-5