15
3.3.1.2 Functional principle of CO
2-
and VOC sensor system modules
The CO
2
sensor system module and the VOC sensor system module are each combined with a humidity/
temperature sensor.
Only one sensor module may be installed in the unit.
The CO
2
sensor system module and the VOC sensor system module both offer you the option to evaluate relative air humidity
as well as the air quality for controlling the ventilation unit. The VOC sensor system module detects volatile hydrocarbons (VOC)
and the CO
2
sensor system module, using NDIR (nondispersive infrared sensor) technology, detects carbon dioxide (CO
2
). Volatile
hydrocarbons correlate well with the CO
2
concentration in living spaces. Therefore, the fan speeds are regulated in accordance with
the characteristic curve in diagram 2.
0
5
10
15
20
25
30
400
600
800
1000
1200
1400
1600
1800
2000
Airflow Rate [cfm]
CO
2
Concentra5on [ppm]
CO
2
/VOC Control
Co
2
/VOC Concentration [ppm]
The CO
2
and VOC sensor system modules combined with a humidity/temperature sensor can be deactivated
separately if needed, in accordance with the humidity or air quality control. If both sensor system modules are
configured as active, the unit will be controlled by the sensor that measures the highest levels.
The required hardware settings on the control system are only allowed to be made by competent, qualified
personnel!
3.4
Maintenance by user
If the maintenance work is not carried out regularly, this will affect the functionality of the decentralized ventilation
unit!
Replace the filters at least every six months. This ensures a pleasant and healthy air quality, and the unit will be
protected against contamination.
The maintenance of the ventilation unit for the user is limited to changing the filters periodically and to cleaning the unit on the
surface, if needed. Check the filters if you are requested to do so by the flashing of filter change LED.
Cleaning the surface of the unit, and specifically the control panel, should be done using a damp cloth and a mild
soap solution. Never use just a dry cloth!
Unsuitable cleaning agents are:
Alcohol (> 5%)
Acetone
Benzene or carbon tetrachloride
All types of “strong” cleaning agents
Scouring agents
Glass cleaners and similar
Instructions for units with a second room connection.
The filter mats should be replaced or cleaned on the exhaust air valves (e.g. bathroom, kitchen) every 2 - 3 months or when
deemed necessary by visual inspection.
Diagram 2: Factory setting characteristic curve for
Automatic operating mode with CO2 / VOC control
