We are handling core and shell commercial project .the fresh air is supplied from the terrace inline fans and directly feed in to AHU. The fresh air is mixed with return air and going to the ventilation zones office 1 ,office 2 and office 3 Ahu capacity is 10000 cfm Office 1 voz 500 Office 2 voz 600 Office 3 voz 700 Since we have vav system we are considering 30% minimum airflow for the vpz.which is 3000 cfm . We are analyzing the system at 50% load condition hence we are considering 5000 cfm for the system primary airflow. VPS What value we have to consider for vdz zone discharge airflow . We have return air coming from all the zones office 1 ,2 and 3 to the ahu rooms