Swegon WISE - Air Flow Limitation; Group for Constant Pressure Regulation

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WISE User Manual
Air ow limitation
Why air ow limit groups?
It is common in renovation projects that the existing ventilation
ducts or air handling unit set the limit for the maximum ow to
a certain part of the building or group of rooms. It may then be
desirable to permit a specic maximum ow in individual rooms
and at the same time set a restriction on the total supply air
ow to this group of rooms that for example utilise the same
supply air duct, where the rooms can be permitted to have a
specic supply air ow provided that the total ow to the group
of rooms does not exceed a certain limit.
How does an air ow limit group work?
Rooms can be included in an air ow limit group. The group
limits each room’s maximum supply air ow. The group controls
each room’s requested air ow, and if the sum of the requested
supply air for all included rooms is higher than the limit value for
the group, the group restricts the supply air ow for all included
rooms. If the limit value for the group is exceeded, the air ow to
each room in the group is lowered proportionally.
For example: If the sum of the desired supply air ow for the
group is 1200l/s and the limit value for the group is 1000l/s,
i.e. 20% above the limit value, the set point for the supply air in
each room is lowered by 20%.
Basic circuit diagram, group for constant pressure regulation in
ring-fed duct systems
Group for constant pressure
regulation
Why a group for constant pressure
regulation?
It’s possible to create groups for constant pressure regulation
on a zone level, which can be used for example in ring-fed duct
systems. This type of group can consist of one or more WISE
Dampers as well as one or more WISE DPS, both on pressure
holding supply air (PS) and extract air dampers (PE).
How does a group work for constant
pressure regulation?
The group uses a common pressure set point value that is
specied for the whole group of pressure holding dampers. The
measured pressure is given by the duct pressure sensor/sensors
WISE DPS in the group. It is selectable whether the average
value, minimum or maximum value for duct pressure should be
used, where the average value is the default.
The WISE Dampers that belong to a group are controlled
synchronously towards a damper position to achieve the
required pressure, so that the system does not start to uctuate
or counteract itself. Accordingly, all WISE Dampers move simul-
taneously and towards the same pressure set point value.
For emergency mode, you can specify that another pressure set
point value should apply for the group, rather than the one that
applies for normal operations.
WISE Damper
( FE)
WISE Damper
( PS)
WISE Damper
( PS)
WISE DPS
WISE DPS