5.6 Air quality control (VntCtl11y, 12y, 13y)
5.6.1 CO2 / carbon dioxide, (AQualCtl21y)
By using a CO
2
sensor as an input from room and / or extract duct, this function
controls the fan speeds to keep the set ppm-level. Fan Boost, Kitchen Hood and
Fire Place have priority, so that the air quality control does not influence the fan
speed. Comfort operating mode already runs with maximum fan speed for the
system, so that AQ control does not have any influence. For Economy and
Unoccupied, separate setpoints can be specified.
The air quality controller increases the fan speed to supply more fresh air and
prevent the degree of air pollution from exceeding the setpoint. The calculation is
performed by a PI-controller. Maximum speed is the setting for Comfort operating
mode, minimum speed is defined by the active operating mode.
During active air quality control, the speed of both fans will be increased and
decreased linearly between the maximum and minimum vales. When the ppm
value drops below the setpoint, air quality controlling reduces the fan speed until
the defined level for the active operating mode is reached.
It is possible to use one extract air sensor (0…10V), and one room air quality
sensor QMX3.P70. In this case, the highest value of all valid sensors is used for
fan controlling.
Sensor measuring range (default 0…2000ppm) can be set for the linear signal 0…
10 V to enable the use of various types of sensors. Min and max values are
settable in the field via APP.
In duct pressure operation (see Basic configuration [➙ 27]), air quality control is
blocked if the configuration of the room influence to fan speed is in mode 2, 3 or
4.
Air Quality controller, actuator output diagram
Application functionalities
Air quality control (VntCtl11y, 12y, 13y)
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