Assortment / System Description

Room pressurization and fume hood
control
Fume hood
21
A6V10866237_en--_b_08 209 | 275
and activation of any special operating modes should be based on documented
safety procedures for the laboratory.
Occupancy schedule source – Specifies whether the fume hood responds to
its own occupancy schedule or to one for the room.
Emergency Flow – In many laboratories, work procedures for handling a spill or
other problem in the hood is to close the sash and press the button to call for
more air flow. Details for increasing the flow level are configurable, and should
be set according to the safety procedures of the laboratory. The controller can
indicate this state to the BAS so it can be announced to selected personnel.
Unoccupied – The application may be programmed to respond differently
depending on the presence of workers. Parameters for triggering sash opening
alarms may change. Sashes should be closed when workers are present. If the
client’s safety policies support the practice, air flow levels or velocities may
change with occupancy. As an energy conservation measure, this is inferior to
closing the sash.
Fire – Special flow rates can be selected to be applied in case a fire erupts in
the facility. The application supports this function.
Decommissioned – The client’s activity may eliminate the need for a particular
fume hood for a long time. The application supports putting the hood
completely out of service for laboratories that have the necessary
administrative procedures.
Several mode variables interact within the control application to determine the
operating mode, based on configuration data and dynamic inputs. Some of
these features help conserve energy in a laboratory, but might also affect
safety. Decisions about what to implement and how should always include
input from someone responsible for safety in the laboratory.
Presence detector for sash alert – Defines if the presence detector has an
effect on the sash alert. If the presence detector alert is inactive, then there is
no effect.
If presence detector alert is active and the presence detector indicates
presence, then sash area / position is compared to the occupied alert area or
occupied alert position to determine if sash alert should be on or off. If
presence detector indicates absent, sash area / position is compared to
unoccupied alert area or unoccupied alert position to determine if sash alert
should be on or off.
Occupied alert area – When the sash is open beyond this level and fume hood
occupancy is Occupied or Override to Occupied, or, presence detection alert is
active and presence is detected, then fume hood sash open alert will be
triggered.
Occupied alert position – When the sash is open beyond this level and fume
hood occupancy is Occupied or Override to Occupied, or, presence detection
alert is active and presence is detected, then fume hood sash open alert will be
triggered.
Unoccupied alert area – When the sash is open beyond this level and fume
hood occupancy is Unoccupied or Pending Unoccupied, or, presence detection
alert is active and current detection indicates absence, then fume hood sash
open alert will be triggered.
Unoccupied alert position – When the sash is open beyond this level and fume
hood occupancy is Unoccupied or Pending Unoccupied, or, presence detection
alert is active and current detection indicates absence, then the fume hood
sash open alert will be triggered.
Maximum opening alert area – Defines maximum safe operating sash height.
When the sash is open beyond this level, fume hood sash maximum alert, is
triggered (Instant buzzer and yellow LED on ODP). This is not dependent on
fume hood occupancy state or presence detection.
Maximum opening alert position – Defines maximum safe operating sash
height. When the sash is open beyond this level, fume hood sash maximum
alert, is triggered (immediate indication on ODP). This is not dependent on
fume hood occupancy state or presence detector.
Fume hood
Fume hood sash