Airflow Network - Sensors, Air quality, Ventilation Schedule

Hi all,

I’ve followed @chris example for AFN script from this post Detailed HVAC Templates and Support for the Airflow Network! (very useful thank you!) to set up a simulation of 3 zones - seminar room, riser for ventilation and a roof cowl.

I’m simulating a naturally ventilated building. The ventilation is automated through BMS based on internal temperature and CO2 sensors. When either of the setpoints is reached, the windows and riser openings open simultaneously to drive the airflow through the roof.

A few questions arose with this setup:

  1. Sensor location - The ventilation system is connected between the 3 zones but the sensors are placed in the seminar room. Is it possible to define a sensor location? If not, does it take the average temperature across all 3 zones to trigger the ventilation setpoint?

  2. Air quality - is it possible to set up ventilation setpoint based on CO2 or at least air flow threshold?
    In terms of outputs I’m able to get the airflow in air changes per hour. Is it possible to change units? Is it possible to output CO2 concentration?

  3. Ventilation schedule - the hint says on-off schedule should be used to define a possibility of ventilation. In my experiment I’m trying to define a precise percentage of window opening at particular times of day based on measured data. I have therefore used Fractional schedule and assumed that e.g. 0.2 means the openable windows were open to 20% at the time. Is this understanding correct? Does that mean the simulation will force the windows to be open to 20% overriding the temperature setpoint?

Answer to any of these questions would be much appreciated. I’m attaching my script for clarity.
Naturally ventilated room_230315.gh (312.2 KB)

Thanks!
Zuzana