Regin REGIO EEDO, Manual, Page: 15 / 108

Control functions
The temperature range between the heating and cooling setpoints is defined as the deadband. The controller
is in heating mode when the room temperature is lower than [heating setpoint plus half the deadband], and
in cooling mode when the room temperature is higher than [cooling setpoint minus half the deadband].
When in heating mode, the controller outputs both a heating signal, Y1, and a VAV signal, Y2, that are
configured on the controller outputs by using the values listed in
Table 2-3 .
When in cooling mode, the controller outputs a VAV signal, Y2, that is configured on the controller outputs
by using the value listed in
Table 2-3 .
Maximum and minimum limits for the heating 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 2-7 Controller output configuration values and controller output types.
Output signal Controller output configuration value Controller output type
Y1 Heating Analog
Heating valve, increase
Heating valve, decrease Digital
Digital
Heating valve, thermal (PWM) Digital
Y2 VAV Analog
Figure 2-10 illustrates the control behaviour when the controller regulates based on heating and cooling
demand, when no maximum or minimum limits are set for the heating output signal, and when a minimum
limit is set for the VAV output signal.
The heating demand increases as the room temperature falls. When the room temperature falls below the
heating setpoint,
Y1: Heating signal increases to respond to the heating demand. At 100% heating demand,
Y1: Heating signal reaches its maximum. When the room temperature is in the range between the heating
setpoint and the deadband centre, and no heating demand exists, Y1: Heating signal is at its minimum.
The cooling demand increases as the room temperature rises. When the room temperature rises above the
cooling setpoint,
Y2: VAV signal increases to respond to the cooling demand. At 100% cooling demand, Y2:
VAV signal reaches its maximum. Y2: VAV signal never goes below its set minimum limit.
Figure 2-10 Control behaviour for the H VAV controller mode when the controller regulates based on
heating and cooling demand.
2.1.8 C VAV
This controller mode is suitable for room HVAC systems that use a chilled beam as cooling device, where
the beam contains a cooling valve and a damper that regulates low supply air temperature that is distributed
Y1: Heating signal Y2: VAV signal
Output
Max: 100%
Heating
setpoint
Cooling
setpoint
Min: 0%
Deadband
Room temperature
100% 100% 0% 0%
Cooling demand Heating demand
0%
Min VAV: 20%
Regio Eedo manual, Rev. D 15