Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Your supply/design air flowrate should account for ventilation loads; I recommend refering to the Engineering Reference or Input Output Guide (or here).
However, the best way to find out would to be to run a test (i.e., all mechanical ventilation, all natural ventilation, no ventilation) to see how your design air changes. If those results don't provide an answer, present them here again so everyone has more information.
