Assortment / System Description

Room pressurization and fume hood control
Pressurized room, temperature control
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● Coordination of airflow demands for heating, cooling, and ventilation
● Airflow monitoring and alarm values
● Multiple segment support
(A segment can include any of the following: supply terminal / extract
terminal / supply + extract pair / independent exhaust terminal - fume
hood).
Description Name Default value
Room pressurization mode
▶ Set the direction of pressurization for the room,
and the direction of net air transfer between the
room and surrounding spaces.
1:Neutral
▶ Supply flow and exhaust are equal. Contamination
is not controlled. Alarm is disabled.
2:Positive pressure
▶ Supply flow is more than extract. Used to keep
contaminants out of the room.
3:Negative pressure
▶ Extract flow is more than supply. Used to contain
contaminants in the room.
PRMod 1:Neutral
Tracking mode
▶ Select the flow tracking algorithm according to
project specifications. If it is not specified, select
according to PRMod.
1:Supply air tracks extract air
▶ Typically chosen for negatively pressurized rooms.
Controller calculates exhaust flow setpoint from
room demands and calculates supply flow setpoint
from exhaust.
2:Extract air tracks supply air
▶ Typically chosen for positively pressurized rooms.
Controller calculates supply flow setpoint from room
demands and calculates exhaust flow setpoint from
supply.
TckMod 1:Supply air
tracks extract air
Transferred air volume flow setpoint
▶ Controller maintains this value as the difference
between supply and extract flow. Set as a positive
number.
SpAirFlTrn 10 [m3/h]
For example: In a room with negative pressure, the extract air volume setpoint
is = 600, for supply air = 500 and SpAirFlTrn = 100.
In a room with positive pressure, the extract air volume setpoint is = 600, for
supply air = 700 and AirFlTrn = 100.
The differential pressure air volume flow cascade calculates flow setpoints for
supply and extract terminals in a room to accomplish pressurization. The
difference between supply and extract flows is dynamically adjusted to drive
measured room pressure to its configured setpoint. The setpoints are selected
to accomplish heating, cooling, and ventilation within constraints of the
minimum and maximum flow rates for the terminals.
Room pressure PID adjusts the transfer airflow to drive the measured pressure
to the setpoint. The range of adjustment for transfer airflow is set by two
configuration value objects, minimum transferred air volume flow and maximum
transferred air volume flow.
Differential pressure
flow cascade control