Place spaces in all areas of the building model to achieve an accurate heating and cooling loads analysis with Systems Analysis or gbXML Export.
Revit uses the space component to maintain information about the area where it is placed. Spaces store values for a variety of parameters that affect a heating and cooling load analysis for a project. Be sure to place spaces in plenums and shafts, chases, and sliver spaces that would not be typically assigned a room component by an architect in the architectural model.
Rooms and Spaces
Rooms and spaces are independent components used for different purposes. Rooms are architectural components used to maintain information about occupied areas. Spaces are exclusively used for the MEP disciplines to analyze volume. They contain parameters that maintain information about the areas in which they have been placed. This information is used for performing a heating and cooling loads analysis with Systems Analysis or gbXML Export.
Spaces can be placed (added) and unplaced, and deleted. Unplacing spaces is not the same as deleting spaces. Spaces are immediately assigned to the Default zone when they are initially added to a project. Spaces can be viewed in a section view. Spaces cannot be viewed or placed in elevation or 3D views.
Spaces should be placed throughout the model, including unoccupied areas such as plenums areas. Spaces that are created (manually or automatically) in an area that contains a room are created as occupied (Occupiable parameter selected).
Room-bounding Components
When placed in an enclosed area, the volume for a space is calculated to the surfaces of room-bounding components, such as walls, floors, ceilings, roofs, and space separation lines. The volume for the space expands horizontally and vertically to the extent of the face of the room-bounding components. Surfaces fall into one of two categories:
- Exterior. Except when the component’s type parameter, Function, is specified as Interior or Core/Shaft, surfaces for room-bounding components (such as walls) have spaces adjacent on one side only, or they have no spaces adjacent and are treated as exterior surfaces. Systems Analysis treats these surfaces as exterior, even if they are interior.
- Interior. These surfaces for room-bounding components that have spaces adjacent on both sides are treated as interior surfaces or components whose type parameter, Function is specified as Interior or Core/Shaft.
When spaces are not placed throughout the model, internal walls can be incorrectly identified as exterior walls, which results in an inaccurate heating and cooling loads analysis with Systems Analysis or gbXML Export. The only exception is when the type parameter, Function, is specified as Interior or Core/Shaft for the room-bounding component.
For example, assume that the walls in the following illustration do not have their Function type parameter specified as either Interior or Core/Shaft. The illustration shows several areas where a space has not been placed. In each case, the surface for the office wall that is adjacent to the area is considered exterior even though it is an interior wall.
