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Vent Door (Inlet)
Opening
(% of the Total
Opening Time)
Total Opening
Time
CLOSED
Stage 1
starts
ROOM
TEMP.
Stage 2
starts
Stage 3
starts
Stage 4
starts
Stage 1
opening
Minimum
Ventilation
Stage 2
opening
Stage 3
opening
Stage 4
opening
Last stage
starts
Over-opening
bandwidth
Last stage
opening
Over
opening
Operating Diagram of a
Timer-based Vent Door (Inlet)
6.5.1
Timer-based Vent Doors (Inlets)
6.5.1.1 Principle of Operation
When timer-based vent doors (inlets) are used, you
must first specify the total time that is required to
open each actuator. Then, you must associate an
opening with the start-up of each fan stage (open-
ings are defined as a percentage of the total open-
ing time). As the room temperature increases and
new stages are activated, vent doors (inlets) will
open or close accordingly.
Vent door (inlet) opening in minimum ventilation
Vent doors (inlets) are at their “Closed” position
during the Off Time portion of minimum ventilation
cycles; during the On Time portion, they open to
the position associated with stage 1.
Over-opening
A supplementary stage can be defined in order to
continue opening vent doors (inlets) beyond the ac-
tivation temperature of the last ventilation stage.
This over-opening stage is used to direct the airflow
more efficiently during periods of warm weather.
When all reference points of ventilation stages are
defined, the user can specify the temperature at
which vent doors (inlets) reach their over-opening
position (Start T° of the last stage + over-opening
bandwidth).
Closing Vent Doors (Inlets)
Vent doors (inlets) can either close when the con-
troller enters in natural ventilation or when the
controller reaches a user-defined tunnel ventilation
stage. Refer to the Installation Setup chapter to
close vent doors in natural ventilation (section 4.5)
or refer to section 6.4.4 to choose at what tunnel
stage vent doors (inlets) must close.
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6.2.2
Stage 1 Ramping (Transition
between Min. Vent. & Stage 1)
The controller can gradually increase (or decrease)
the running time of the fans to smooth out the
transition from the minimum ventilation cycle to
full operation of stage 1 fans.
At room temperatures at or below the set point,
the controller operates the fans of stage 1 accord-
ing to the minimum ventilation cycle.
If the room temperature rises above the set point,
a new On Time is calculated periodically as the tem-
Stage 1 Differential
0.3°F
Min. Vent.Cycles
On Time
On Time =
Cycle time
Room T°
Run Time
A
B
C
Stage 1
Start T°
Ramping Settings
To use the ramping function, enable the “Ramping
on stage 1” function in the Installation Setup (sec-
tion 4.5) and adjust the differential of stage 1 in
section 6.2.3.
Stage 1 Ramping
perature increases to allow a smooth progression
(from point A to point B) up to full operation of the
fans when the set point + differential 1 is reached
(when Time Off becomes less than 15 seconds, it is
fixed at 15 seconds until the temperature has
reached the set point + differential 1. At that point,
the fans of stage 1 operate continuously).
If the room temperature decreases 0.3°F below
the set point + differential 1, the On Time value
of the minimum ventilation cycle decreases gradu-
ally from a value equal to the total cycle time (point
C) towards the regular On Time.
