A virtual partition is a partition between 2 zones which exists purely to sub-divide the space up and has no corresponding wall in the actual building.
Virtual partitions are commonly used for separating perimeter zones from core zones when there is to be different HVAC provision or when carrying out daylighting or solar overheating studies in situations where a large open plan space is subject to a high level of solar gain around the perimeter. Virtual partitions can be placed to create separate perimeter and core zones so that the local effect of the solar gain in the perimeter zone may be calculated. In the absence of virtual partitions, the risk of overheating could be underestimated due to the distribution of solar gain throughout the open plan space.
When drawing partitions you can set the Partition type to 2-Virtual in the Drawing option panel. Also for partitions that have already been created you can freely switch the partition type between 1-Standard and 2-Virtual using the same control.
Virtual partitions are modelled using a hole that fills the whole surface area. You cannot draw custom openings on a virtual partition. The model options for controlling the effect of holes equally apply to virtual partition holes: