Regin REGIO EEDO, Manual, Page: 39 / 108

Control functions
Table 2-22 VAV control configuration settings.
Configuration setting Description
VAV control By cooling demand: VAV control is performed based on cooling demand. The VAV
output signal is controlled based on the cooling setpoint and the current room
temperature.
By CO2 demand: VAV control is performed based on fresh air demand. The VAV
output signal is controlled based on the CO
2
setpoint and the current CO
2
level in
the room.
By cooling or CO2, the highest demand: VAV control is performed based on both
cooling and fresh air demand simultaneously. The highest demand determines if the
VAV output signal currently is controlled based on the cooling setpoint and the room
temperature, or the CO
2
setpoint and the CO
2
level in the room (default setting).
Min limit for VAV output, occupied (%) Specifies the minimum limit for the VAV output signal when the controller is in the
occupied controller state.
Min limit for VAV output, standby (%) Specifies the minimum limit for the VAV output signal when the controller is in the
standby controller state.
Min limit for VAV output, unoccupied (%) Specifies the minimum limit for the VAV output signal when the controller is in the
unoccupied controller state.
Min limit for VAV output, off (%) Specifies the minimum limit for the VAV output signal when the controller is in the off
controller state.
Max limit for VAV output (%) Specifies the maximum limit for the VAV output signal.
Max limit for VAV output at heating demand (%) This setting is only applicable for the following controller modes:
✓ H VAV
✓ H C VAV
When this value is greater than zero, the VAV output signal follows the heating
output signal to a maximum that is specified by this value.
Figure 2-34 illustrates the control behaviour for the H VAV controller mode when VAV control is
performed based on cooling demand, a maximum limit is set, and minimum limits for the occupied and
unoccupied controller states are set.
Figure 2-34 VAV control behaviour based on cooling demand when a maximum limit is set, and minimum limits for
the occupied and unoccupied controller states are set.
Figure 2-35 illustrates the control behaviour for the H VAV controller mode when the Max limit for
VAV output at heating demand setting is applied. For example, when a 50% maximum is set, the VAV signal
follows the heating signal as the heating demand increases but never exceeds 50% of its practical maximum
(100%).
Heating signal
VAV signal
Output
Max heating: 100%
Heating
setpoint Cooling
setpoint
Min heating: 0%
Deadband
Room temperature
100%
100% 0% 0%
Cooling demand Heating demand
Min VAV: 20%
Max VAV: 80%
Min VAV: 40%
Occupied
Unnoccupied
Regio Eedo manual, Rev. D 39