The Active Air valve is used in the following situations:
In the example above the valve is opened from 0 to 100% when the greenhouse temperature is from 20 to 22 (=20 + 2) °C.
With the influence "difference Active Air ventilation temperature - outside temperature" the P-band will be increased when it becomes colder outside.
With the influence "radiation: measurement" the P-band will be decreased when it becomes sunny outside.