How should I set the system to ensure CO2 control?

For demand controlled ventilation systems, change the CO₂ setpoint to lower, 400 ppm value, in order to assure the operation at nominal speed. Keep the ventilation on 24 hours a day, 7 days a week, as recommended in BESA VG002 V4 https://www.thebesa.com/media/837990/besa-guidance-vg002-v4.pdf