When the function is activated with start/stop function and the CO2 value rises above settable start value, the fans will start at configured speed, if they are not already running.

The fans will stop when the CO2 value falls to a settable hysteresis (default: 160 ppm) below the start value and after the minimal time for CO2 control has passed.


Configuration example for air quality control (Fan start/stop CO2)



Variable

Available options & Selection

Note


Activate function

Configuration > Functions > Function activation

Air quality control

| No | Fan start/stop function |

| Mixing damper function |

| Fan start/stop + Mixing damper |



Configuration of the air quality control function

Configuration > Functions > Air quality control

Run extract air fan during air quality control

| Yes | No |


Setpoint supply air fan when air quality control

| Low speed | Normal speed | High speed |

Switch to the selected fan level

Setpoint extract air fan when air quality control

| Low speed | Normal speed | High speed |

Control type

| CO2 | RH |



Configure inputs

Configuration > I/O allocation settings > Analog inputs

CO2 room /extract air

Any available I/O

CO2/VOC sensor


Operational settings

Data & Settings > Demand control > Air quality control

CO2 room /extract air

___ ppm

Measured CO2

Start limit fan start/stop

[800] ppm

Mode activates when CO2 level exceeds 800ppm

Mode deactivates when CO2 level reduces below 800-160=640 ppm

Stop hysteresis fan start/stop CO2

[160] ppm

Min time for CO2 control

[20] min

Once activated, the air quality control will remain active for at least 20 min

Demand control

Off | On

Off - mode inactive | On - Mode active


The previously described principal applies if RH is chosen as a control type.


Configuration example for air quality control (Fan start/stop Relative humidity)



Variable

Available options & Selection

Note


Activate function

Configuration > Functions > Function activation

Air quality control

| No | Fan start/stop function |

| Mixing damper function |

| Fan start/stop + Mixing damper |



Configuration of the air quality control function

Configuration > Functions > Air quality control

Run extract air fan during air quality control

| Yes | No |


Setpoint supply air fan when air quality control

| Low speed | Normal speed | High speed |

Switch to the selected fan level

Setpoint extract air fan when air quality control

| Low speed | Normal speed | High speed |

Control type

| CO2 | RH |



Configure inputs

Configuration > I/O allocation settings > Analog inputs

Humidity room /extract air

Any available I/O

RH sensor


Operational settings

Data & Settings > Demand control > Air quality control

Humidity room /extract air

___ %

Measured RH %

Start limit fan start/stop RH

[75] %

Mode activates when RH level exceeds 75%

Mode deactivates when RH level reduces below 75-8=67%

Stop hysteresis fan start/stop RH

[8] %

Min time for RH control

[20] min

Once activated, the air quality control will remain active for at least 20 min

Demand control

Off | On

Off - mode inactive | On - Mode active