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Chapter 5
Functional description
Manual Corrigo Ventilation, revision R
5.3 Humidity control
General
Humidity control can be configured as Humidification, Dehumidification or both Humidification
and Dehumidification.
Two humidity sensors can be connected, a room sensor for control and an optional duct sensor for
maximum limiting. The limit sensor can be omitted.
The humidity control is handled by a PI-controller.
The humidity sensors must give 0…10 V DC for 0…100 % RH.
Humidification
An analogue output is used to control a humidifier. The output will increase on decreasing humidity.
A digital output can also be used to start a humidifier.
Maximum limitation function using duct humidity sensor:
If the maximum limitation is 80 % RH and the hysteresis is 20 % RH, the controller output signal
will begin decreasing at 60 % RH. When halfway to 80 % RH (i.e. when at 70 % RH), half the
output signal will be damped. If the humidity in the duct still reaches 80 % RH, the entire output
signal will be damped.
Dehumidification
An analogue output is used to control a dehumidifier. The output will increase on increasing
humidity. A digital output can also be used to start a dehumidifier.
Humidification/dehumidification
An analogue output is used to control a humidifier. The output will increase on decreasing humidity.
The cooling output Y3 will be activated for dehumidification through condensation. The output will
increase on increasing humidity. This signal overrides the cooling signal from the temperature
controller so the output can be activated for dehumidification even if the temperature controller
demand is zero.
For good temperature control when using cooling for dehumidification it is important that the cooler
is placed first in the air stream so that the exchanger and heater can be used to reheat the air after
dehumidification.
Digital humidity signal
A digital output signal, "Dehumidification/Humidification", can be used for on/off control of
humidifiers/dehumidifiers. The output signal has an activation value and a deactivation value which
are connected to the humidity controller output. The signal is activated when the humidity controller
output rises above the set activation value and is deactivated when the humidity controller output
drops below the set deactivation value.
If a start signal is needed for a cooling unit or a magnetic valve for DX dehumidification, the digital
output signal “Start P1-Cooling” should be used. In this case, the “pump” stop delay should be set to
0 s.
Inputs and outputs
AI
Room humidity sensor
AI
Duct humidity sensor
AO
Humidity control output 0…10 V DC
DO
Dehumidification/Humidification