Determining ventilation load for AHU sizing using HB tools

I have an industrial building where I need to maintain an minimal airflow of 3 m3/m2/hr in my zones using only AHUs. The heating and cooling load of my zones are also provided by these AHUs combined with heatpumps. While the energy simulation determines the heating and cooling loads for the zones, there is no ventilation load provided for the zones.

How to determine the ventilation load for the zones? Can someone provide me with an idea/sample script on how to go about it?