Vents and Holes

Openings tab in model data

Vents

DesignBuilder vents are used for modelling airflow through openings and are added to the model by navigating to the appropriate surface and checking the Vents fitted option. This adds a single vent under each of the windows (if the vent spacing is the same as the window spacing). Alternatively, for more control over the placement position of the vents, you can go to surface level and draw the vents using the Draw vent command.  On surfaces where custom openings have been defined, any changes to vent layout model data on the Opening tab is ignored.

 

 

Note: if you have drawn custom vents at the surface level then these will be used even if the Vents fitted checkbox is not checked. The Vents fitted checkbox only controls the automatic generation of vents, not their use in the calculations.

 

The properties of the vent are defined by the selection of the vent type:

 

 

Holes

Holes are modelled in a similar way to vents with some exceptions:

 

Vent modelling

Calculated Natural Ventilation (Simulations only)

 

Each vent is modelled using:

 

 

Scheduled Natural Ventilation (and Design Calculations)

 

Each vent is modelled using:

 

Hole modelling

Calculated Natural Ventilation (Simulations only)

 

Each hole is modelled using a sub-surface and an airflow connection:

 

 

Scheduled Natural Ventilation (and Design Calcs)

 

Each hole is modelled using a sub-surface and a 'mixing' flow: