Openings tab on Crack Templates Dialog.
Enter the flow characteristics of the cracks around internal and external windows, vents and doors.
Flow coefficients for openings define the flow through the cracks between the opening and the parent surface. In practice this may include any gaps between in openable sections of windows, doors and vents and their frame as well as the gaps between the opening component frame and the surface fabric. If using published data for window, door and vent components, be careful to ensure that both these effects are included in the data provided in DesignBuilder. For example in the AIVC document: is Numerical Data for Air Infiltration & Natural Ventilation Calculations, window leakage data is provided only for the windows themselves and not for the gaps between fabric and the window frames.
Note that the opening crack characteristics are normalised by opening perimeter lengths.