Adjacent Buildings

Adjacent buildings (i.e. other buildings that are touching the modelled building) usually modify the boundary conditions relative to external and also provide shade.

 

There is no explicit way in DesignBuilder 1.2 to model temperatures and heat flows in 2 buildings simultaneously and account for energy transfer between them. Future versions may allow this, but in the meantime there are two options:

 

  1. Model the adjacent building using component blocks (for shading/reflection) and adiabatic surfaces between the buildings. This is the usual way to treat an adjacent building not requiring full simulation and is accurate if the temperature of the adjacent and actual buildings are similar or if there is insulation between the two buildings.
  2. If the adjacent building does require simulation then model it as part of the actual building and separate simulation results at the end.

 

You can set adiabatic adjacent condition data under Constructions on the Constructions tab at surface level.

Merging buildings

Where two separate buildings have been created inadvertently, the blocks of one building can be transferred to the other building using the Transfer blocks command from the Edit menu.

Airflow

If there is airflow between the two buildings and the adjacent building is at the same temperature as the modelled building then you could probably ignore its effect. To model the effect of the airflow through an opening between buildings in detail you should model both buildings as one DB building using the Calculated natural ventilation model option. If you do it this way and the adjacent building uses energy you must separate results for the two buildings at the end. You can use different boiler and chiller fuels to differentiate fuel consumption between the two buildings.

 

If you use the Simple natural ventilation instead of Calculated, DesignBuilder uses an assumed mixing of air between the two buildings based on 'flow per opening area' as set on the Model options dialog on the Advanced tab under Natural Ventilation.