Opening the Snow/Wind Load dialog and clicking the Permeability tab displays the following dialog.
The dialog defines the permeability of structure walls. Wall permeability has a direct effect on generating the coefficients of wind pressure inside a structure. When you select an option its diagram displays in the upper-right corner of the dialog.
The dialog box is divided into 2 fields with certain option groups.
The Side wall permeability field has the following options:
- Left side - Specifies the permeability of the left side wall.
- Right side - Specifies the permeability of the right side wall.
The Front and rear wall permeability field has the following options:
- Front - Specifies the permeability of the front wall.
- Rear - Specifies the permeability of the rear wall.
Note: Permeability is always expressed in %. For a completely open wall, the permeability value is 100%; whereas, for a completely closed wall it is 0%.