Zone air distribution units are placed at the HVAC zone level. To place an ADU, navigate to the HVAC zone, click on the Add air distribution unit tool and then select the required unit from the drop-list. Then, making sure that the cursor is inside the boundary of the zone, left click with the mouse to place the ADU. The ADU will be automatically positioned at the top left of the zone:
You should make sure to add a distribution unit that is compatible with the type of air loop you plan to connect to. The constant volume ADUs available in DesignBuilder can connect to both CAV and VAV air loops, while Variable volume ADUs can only connect to VAV air loops.
Note You must also add a zone extract unit to a zone that contains an ADU in order to connect up the air return path from the zone.