Export gbXML Dialog - Use Room/Space Volumes

When you choose to export the model to gbXML using room/space volumes, use this dialog to specify settings and to validate the analytical model before exporting it.

To open the Export gbXML dialog

1. Open a 3D view of the model.
2. Click File tab Export(gbXML).
3. In the Export gbXML dialog, select Use Room/Space Volumes.

The Export gbXML dialog displays.

General tab

• Building Type: Specifies the type of building according to the gbXML schema 0.37 (similar to ASHRAE).
• Location: Specifies the geographic location for the model. The location establishes the climate and temperatures used in loads calculation.
• Ground Plane: Specifies the level that serves as the ground level reference for the building. Surfaces below this level are considered to be underground. The default level is zero.
• Export Category: Determines which information is to be exported and used for analysis: Rooms or Spaces. This setting determines which parameters are available on the General tab, as well as the information displayed on the Details tab.
• Export Complexity: Specifies the level of detail provided for openings, and whether shading surface information is exported. Shading surfaces are surfaces that are not adjacent to any space, and include surfaces that create a solar obstruction. Simple complexity is used for heating and cooling loads analysis.
  • Simple - curtain walls and curtain systems are exported as a single opening (without individual panels). Simple is more appropriate for energy analysis.
  • Simple with shading surfaces - same as simple, but with shading surface information exported.
  • Complex - curtain walls and curtain systems are exported as multiple openings, panel by panel.
  • Complex with shading surfaces - same as complex, but with shading surface information exported.

    Shading surfaces are not associated with any room/space (roof overhang, free-standing wall).

  • Complex with mullions and shading surfaces - same as complex, but with mullion and shading surface information exported.

    Mullions in curtain walls are exported as shading surfaces. A simple analytical shading surface is produced from mullions, based on the centerline, thickness, and offset.

• Detailed Elements: (available only when Export Category = Rooms)

  See Use Detailed Elements for Material Thermal Properties.

• Project Phase: Specifies the stage of construction to use for analysis.
• Sliver Space Tolerance. Specifies the tolerance for areas that will be considered sliver spaces.
• Building Envelope: Specifies the method to use to determine the building envelope.
  • Use Function Parameter. (default) This method uses the Function type parameter of walls, floors, and building pads to determine the building elements considered to be part of the building envelope. If a wall has one adjacent space, analytical surfaces originating from the wall are classified as exterior surfaces. If a wall has two adjacent spaces and its function is Exterior, Foundation, Retaining, or Soffit, analytical surfaces originating from the wall are classified as interior surfaces. If the wall's function is Interior or Core Shaft, analytical surfaces originating from the wall are classified as interior surfaces, regardless of the number of adjacent spaces.
  • Identify Exterior Elements. This method uses a combination of ray-casting and flood-fill algorithms to identify the building elements that are exposed to the outside of the building, the building envelope. Analytical surfaces originating from the building elements in the envelope are classified as exterior or shading surfaces.
• Building Service: Specifies the heating and cooling system for the building.
• Schematic Types: Specifies the constructions type for the building. Click to open the Schematic Types dialog, where you can specify the materials and insulation (U-values) for the building.
• Building Infiltration Class: Specifies an estimate of outdoor air that enters the building through leaks in the building envelope.

  Infiltration can be specified as:

  • Loose - 0.076 cfm/sqft for tightly constructed walls.
  • Medium - 0.038 cfm/sqft for tightly constructed walls.
  • Tight - 0.019 cfm/sqft for tightly constructed walls
  • None - infiltration is excluded from the calculation of loads.
• Export Default Values: (available only when Export Category = Spaces)

  Exports user-specified values as well as default values for People, Electrical Loads, Occupancy, Lighting, Power Schedules, and Construction Types. Clear this option to export only user-specified values.

Details tab

When you set Export Category to Rooms on the General tab, the Details tab displays rooms in the model. Select an item in the list, and use the Highlight, Isolate, and Show Related Warnings tools to inspect the item.

When you set Export Category to Spaces on the General tab, the Details tab displays spaces and zones in the model. In addition to inspecting spaces, zones, and related analytical surfaces, you can change related settings. See About the Details Tab, Specify Heating and Cooling Parameters for Spaces, and Specify Heating and Cooling Parameters for Zones.