The Geometry in ICE

A building in IDA Indoor Climate and Energy can contain one or several zones (rooms).

A zone is either

• a prism with any number of flat vertical walls, a flat horizontal floor and one ceiling;
• a part of such prism limited by the building's roof;
• a custom polyhedral (an arbitrary volume, bounded by polygons) that may be imported but not edited in ICE.

In addition to windows and openings (doors), different types of heating and cooling units can exist within these restricted surfaces.

The geometry of the building is defined by the corners of one or more building body parts (see above figure). The corners’ x and y co-ordinates are indicated in a local coordinate system for the building (called the building system below) that moves and rotates with the building. Before editing, the origin of coordinates for the building system coincides with the lower left corner of the building. The building system is then also at the origin of coordinates for the global coordinate system (which is marked by the origin marker).

The shape of building body part is limited to

• prisms with flat vertical walls
• a part of such prism limited by the roof. The roof may consist of one or more flat polygons with slope from 0° (horizontal, outer side upward) to 90° (vertical).
• a custom polyhedral that may be imported but not edited in ICE.

The zone geometry is described relative to a point in the building system, where the z-coordinate gives the height of the floor above ground level.

The zone is defined by its height plus the corners of the floor. The corners’ x and y co-ordinates are indicated in a local coordinate system for the zone (called the zone system below) that moves and rotates with the zone. The zone system is defined by the origin’s coordinates (in the building system) and the rotation angle around the z-axis.

The shape of the zones is limited to prisms with vertical walls. If the prism is intersecting with the roof, only the part under the roof is included in the zone.

A local coordinate system (called the surface system) is defined on every enclosing surface. For vertical walls, the origin of coordinates is located in the lower left corner of the surface (from inside the zone). For floors and horizontal ceilings, the surface system coincides with the zone system (with z-coordinate omitted). For slanted ceilings (or fragments of ceiling), the x-coordinate is always horizontal passes thru the lowest corner of the ceiling (or fragment) and the y-coordinates is located in the ceiling's plane, is perpendicular to the x-axis and passes thru the leftmost corner of the ceiling (or fragment).

The surface system is used to indicate the position for features (such as openings) on the surface:

The geometry for objects like windows and heating devices is defined by a rectangle. The insertion point of the rectangle (lower left corner) is given in the surface system. If the surface (wall, floor, or ceiling) is not rectangular, the position of an object is the intersection of the rectangle with surface.

See also Building and zone geometry import.