We are using the 62MZ Calculator spreadsheet for an office building. The HVAC system does not utilize VAV boxes or any kind of terminal unit. Rather, it just feeds directly into each space. How do we fill in the CFM (Vdzd) cell for the critical zones? Do we need to calculate it from the space load, measure it, or can we just use a conservative engineering rule of thumb?

Thank you in advance for any help here.