Regin REGIO EEDO, Manual, Page: 16 / 108

Control functions
into the room to provide cooling and fresh air. The air must be pretreated and cooled, since the damper itself
does not have any cooling capacity.
The controller acts as a cooling controller and regulates based on the cooling setpoint and the current room
temperature. In addition, the controller can be set to also regulate based on fresh air demand, or based on
cooling demand and fresh air demand simultaneously, see section
2.6 . The controller regulates based on fresh
air demand by using CO
2
control, see section 2.9 .
The controller is always in cooling mode and outputs a cooling signal, Y1, and a VAV signal, Y2, in sequence
that are configured on the controller outputs by using the configuration values listed in table
Table 2-8 .
The Y1 and Y2 signal sequence order is configurable.
Maximum and minimum limits for the cooling output signal can be set, see section 2.2 . Maximum and
minimum limits for the VAV output signal are set via the VAV control function, see section 2.6 .
Table 2-8 Controller output configuration values and controller output types.
Output signal Controller output configuration value Controller output type
Y1 Cooling Analog
Cooling valve, increase
Cooling valve, decrease
Digital
Digital
Cooling valve, thermal (PWM) Digital
Y2 VAV Analog
Figure 2-11 illustrates the control behaviour when the controller regulates based on cooling demand, when
no maximum or minimum limits are set for the cooling output signal, and when a minimum limit is set for
the VAV output signal.
The cooling demand increases as the room temperature rises. When the room temperature rises above the
cooling setpoint,
Y1: Cooling signal increases to respond to the cooling demand. At 49% cooling demand, Y1:
Cooling signal reaches its maximum. When the room temperature rises further and the cooling demand
exceeds 51%, Y2: VAV signal increases while Y1: Cooling signal stays at its maximum. At 100% cooling
demand, Y2: VAV signal reaches its maximum.
When the room temperature is lower than the cooling setpoint and no cooling demand exists, both Y1:
Cooling signal and Y2: VAV signal are at their minimum.
Figure 2-11 Control behaviour for the C VAV controller mode when the controller regulates based on cooling
demand.
Y2: VAV signal
Output
Max: 100%
Cooling
setpoint
Min: 0%
Room temperature
Cooling demand
100% 51%
49% 0%
Y1: Cooling signal
Min VAV: 20%
16 Regio Eedo manual, Rev. D