Ducts

In this section all duct related information needed to satisfy the Exchange HVAC Model - (Systems) will be described.

Owner History

Information Needed	Man	Opt	Rec	Actor Supplying	Functional Part
The owner history of the flow segments must be asserted.				HVAC Designer	Model Flow Segment (FP)

General Attributes

Information Needed	Man	Opt	Rec	Actor Supplying	Functional Part
General attributes of the flow segment types and occurrences may be specified including:
name to extend identification of the type or occurrence				HVAC Designer	Model Flow Segment (FP)
description that can be used for any further qualifying information				HVAC Designer	Model Flow Segment (FP)

Placement and Shape

Note that since IFC generally allows for elements to have multiple shape representations, provision of shape representations of ductwork systems at different lifecycle stages should be considered as cumulative and not as alternative.

Information Needed	Man	Opt	Rec	Actor Supplying	Functional Part
Where information about ductwork is to be exchanged as part of the building model specification, the placement and shape representation should be asserted. For a ductwork system, the principal shape representation to be used may differ at particular stages in the project life cycle. Shape representations as used should have values for representation identifier and representation type attributes set as given in the functional part. For early design stages, line based representation may be used as defined by the Axis Representation in the functional part For detailed design stages, Body Representation may be used. These may be assigned to the type using mapped representations or to the occurrence as 'own' shape representations. In an exchange of ductwork information, the forms of body representation used should be clearly indicated to the receiving system as being: Swept solid CSG Bounding box Boundary representation (Brep)				HVAC Designer	Model Flow Segment (FP)

Properties

Specification of properties that may be assigned through property sets as defined in the functional part. For flow segments, properties may be defined either for the segment type or the segment occurrence or for both (although definition for both is not expected in practice). Properties specified may include:

Information Needed	Man	Opt	Rec	Actor Supplying	Functional Part
Cross sectional shape of the duct.				HVAC Designer	Model Flow Segment (FP)
Material from which the duct segment is constructed.				HVAC Designer	Model Flow Segment (FP)
The thickness of the duct segment material				HVAC Designer	Model Flow Segment (FP)
Pressure classification as defined by the authority having jurisdiction (e.g., DW144, SMACNA, etc.)				HVAC Designer	Model Flow Segment (FP)
Weight per unit length.				HVAC Designer	Model Flow Segment (FP)
Allowable maximum and minimum working pressure (relative to ambient pressure). May be considered to be optional in earlier design stages but is recommended for inclusion at coordinated design stage.				HVAC Designer	Model Flow Segment (FP)
Allowable maximum and minimum temperature. May be considered to be optional in earlier design stages but is recommended for inclusion at coordinated design stage.				HVAC Designer	Model Flow Segment (FP)
The type of seam to be used along the longitudinal axis of the duct segment. May be considered to be optional in earlier design stages but is recommended for inclusion at coordinated design stage.				HVAC Designer	Model Flow Segment (FP)
Length of the duct segment. Note that it is recommended that duct length be included in the property set. It may also be specified using methods of measurement as a length measure				HVAC Designer	Model Flow Segment (FP)
The nominal width or diameter (if circular) of a duct or, in the case of a circular cross section, the diameter.				HVAC Designer	Model Flow Segment (FP)
The nominal height of the segment (omitted if the duct segment is circular).				HVAC Designer	Model Flow Segment (FP)
The end-style treatment of the duct segment manufactured.				HVAC Designer	Model Flow Segment (FP)
The type of reinforcement, if any, used for the duct segment				HVAC Designer	Model Flow Segment (FP)
The spacing between reinforcing elements				HVAC Designer	Model Flow Segment (FP)