Direct secondary ventilation The following example shows the graphic representation of direct secondary ventilation. Connect the ventilation ducts (1) to the downpipe (2). In the component library, expand the Ventilation end point/ventilation valve group with the right mouse button and select the ventilation end point. Place the ventilation end point at the end of the ventilation duct. Note: The layer connection is created automatically during detection. Example of direct secondary ventilation after detection: