CO2 sensor alarm when conditions vary 10%

The credit template requires the CO2 sensors to be programmed to generate an alarm when the conditions vary by 10% or more from the design value. Currently we are designing a facility AHU and VAV BOXES that requires 4 rooms to have CO2 sensors, but wouldnt this requirement only apply to constant volume systems since the ventilation of the rooms would depend on the CO2 sensors therefore it would most of the time not be at full occupancy and most of the time below the minimum outdoor air required? Thanks