IfcDistributionPort

Definition from IAI: The product IfcDistributionPort defines the occurrence of a specialized port for use within the context of distribution elements. Its type is defined by IfcDistributionPortType or its subtypes.

Property Set Use Definition:

The property sets relating to this entity are defined by the IfcPropertySet and attached by the IfcRelDefinesByProperties relationship. It is accessible by the inverse IsDefinedBy relationship. The following property set definitions specific to this entity are part of this IFC release:

- Pset_DistributionPortDuct: property set for duct distribution port occurrences
- Pset_DistributionPortPipe: property set for pipe distribution port occurrences

> HISTORY: New entity in IFC 2x2.

Use Definitions

The images below will help present the concepts of how an IfcDistributionPort is used to connect occurrences together in a distribution system. These concepts will be exemplified using a duct segment connecting to a tee and distributing air out through two connecting duct segments, as shown below in Figure 1.

Figure 1: A tee distributing air out through two connecting duct segments

For the duct segments in this example, the concepts of the type, occurrence and performance history entities would be modeled using the following instances and shown in Figure 2:

- The type (and representation) is defined using IfcDuctSegmentType from the IfcHvacDomain schema
- The occurrences (and placements) are defined using IfcFlowSegment from the IfcSharedBldgServicesDomain schema
- The performance history characteristics for these occurrence are defined using IfcPerformanceHistory from the IfcControlExtension schema

Figure 2: IFC entities used to represent a duct segment

The fitting would be represented in a similar manner using instances of IfcDuctFittingType, IfcFlowFitting and IfcPerformanceHistory for the type, occurrence and performance history entities respectively. Figure 3 includes all the type and occurrence entities that are involved in the duct and fitting example, as well as how the property sets defining type are related. Also included is how a port is involved in the connectivity of these entities.

Figure 3: IFC entities used to represent the full example, including ports

If we look specifically at the point in the example where the duct segment connects to the inlet of the tee fitting, as shown in Figure 4, there is a port on the duct and a port on the tee which are used to logically relate the two together so that a connection is inferred. This connection may be physically realized with a specific fitting that is used to physically connect the duct segment and the tee fitting, such as a flange or coupling.
It is important to note that the notion of a port is different from that of a connector.

Figure 4: The relationships between distribution elements, ports and connectors

Figure 5 indicates how fluid flow properties and connection-specific information may be incorporated at the mass-flow boundary layers within this example.

Figure 5: Modeling mass-flow characteristics across boundary layers

EXPRESS specification:

ENTITY IfcDistributionPort
SUBTYPE OF ( | IfcPort);
FlowDirection | : | OPTIONAL IfcFlowDirectionEnum;
END_ENTITY;

Attribute definitions:

FlowDirection | : | Enumeration that identifies if this port is a Sink (inlet), a Source (outlet) or both a SinkAndSource.

Inheritance graph

ENTITY IfcDistributionPort;
ENTITY IfcRoot;
GlobalId | : | IfcGloballyUniqueId;
OwnerHistory | : | IfcOwnerHistory;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;
ENTITY IfcObjectDefinition;
INVERSE
HasAssignments | : | SET OF IfcRelAssigns FOR RelatedObjects;
IsDecomposedBy | : | SET OF IfcRelDecomposes FOR RelatingObject;
Decomposes | : | SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;
HasAssociations | : | SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject;
ObjectType | : | OPTIONAL IfcLabel;
INVERSE
IsDefinedBy | : | SET OF IfcRelDefines FOR RelatedObjects;
ENTITY IfcProduct;
ObjectPlacement | : | OPTIONAL IfcObjectPlacement;
Representation | : | OPTIONAL IfcProductRepresentation;
INVERSE
ReferencedBy | : | SET OF IfcRelAssignsToProduct FOR RelatingProduct;
ENTITY IfcPort;
INVERSE
ContainedIn | : | IfcRelConnectsPortToElement FOR RelatingPort;
ConnectedFrom | : | SET [0:1] OF IfcRelConnectsPorts FOR RelatedPort;
ConnectedTo | : | SET [0:1] OF IfcRelConnectsPorts FOR RelatingPort;
ENTITY IfcDistributionPort;
FlowDirection | : | OPTIONAL IfcFlowDirectionEnum;
END_ENTITY;