About Creating Parts References

This topic describes the different ways of defining and customizing your HVAC data model.

This page discusses:

Data Model Management

There are two ways to implement the data model.

Without Customizing Data Model

All the HVAC parts are created from the twelve classes delivered by default. For each class, you must define the list of your part subtypes associated with this class. You can use this mode if you do not need to add dedicated attributes on each part subtype.

Part Subtype Behavior Class
Tee HVAC_Tee
Reducing Tee HVAC_Tee
Electrical Damper HVAC_Damper
Manual Damper HVAC_Damper
etc. etc.

Customizing Data Model

With this implementation, the number of part subtypes and classes is the same. Create one class for each part subtype. For each class, you can create the dedicated attributes you want for this class.

Part Subtype Behavior Class
Tee DS_Tee (derivate from HVAC_Tee)
Reducing Tee DS_Reducing_Tee (derivate from HVAC_Tee)
Electrical Damper DS_Electrical_Damper (derivate from HVAC_Damper)
Manual Damper DS_Manual_Damper (derivate from HVAC_Damper)
etc. etc

DS_xxx is the new class created with the customization data model. For more information, see Unified Typing Configuration Tools.

Behavior Detail of HVAC Class

The twelve HVAC classes are defined to provide a dedicated behavior in the app. The table below describes the available capability and is updated with the coming capability.

Object Type Behavior Name Behavior
Access Cover HVAC_AccessCover
Cap HVAC_Cap
Damper HVAC_Damper create electrical port
Elbow HVAC_Elbow

Dedicated attributes:

  • reference bend angle: angle value of the reference part
  • bend angle: angle value of the part used in the design context
  • bend radius: bend radius of the elbow
  • guidance: for noncircular shape, the design of the part is different depending on the direction (up, down, left, right). The possible values are:
    • horizontal
    • vertical
    • none

Flange HVAC_Flange
Gasket HVAC_Gasket
Reducer HVAC_Reducer
Saddle HVAC_Saddle
Silencer HVAC_Silencer
Tee HVAC_Tee Tee must have 3 ports even if it is a reducing tee

Dedicated attributes: reference bend angle: angle value of the reference part

Transition HVAC_Transition
Instrument HVAC_Instrument create electrical port
Miscellaneous HVAC_Miscellaneous create electrical port

Creation Mode of HVAC Object

Previous Behavior

In the HVAC Design apps, the instantiation/new reference of the HVAC reference object was hard-coded from the type object:

  • For a HVAC part, the instance is created from an existing reference.
  • For a HVAC route (rigid or flexible), the instance is created from a new reference.

There is one exception: if the HVAC part contains a parametric set called DS Fluidic Parameters to realize a cut elbow.

Current Behavior

In the HVAC Design apps, the instantiation/new reference of the HVAC object is based on new attributes: Instantiation Rule or Reference mode.

HVAC Object Definition

When you create a reference of a HVAC object, you can select the value of the Instantiation Rule attribute among its three following values:

  • Reuse Reference: this is the default value. During the instantiation, the instance is created from the selected reference.
  • New Reference: during the instantiation, the reference is duplicated and the instance is created from this new reference. A part with this value is considered to be a parametric part where all the parameters can be modified during the instantiation.
  • Reuse or New Reference: this option allows both capability described above. According to the command, the selection of the final value (reuse or new reference) can be automatic (cut elbow for example) or needs a user input.

Important: A route with the Reuse Reference value has the same behavior as a part. Engineering connections are created to connect the route to the other parts. There are as many route references as possible route lengths to use.
Tips:
  • Use the New Reference value when the standard and port attributes are modified. For example, if the nominal size is different for piping/tubing or raceway objects, or the height and width for HVAC objects.
  • Use the Reuse or New Reference value when the standard and port attributes are the same but the geometric attributes are different. For example, cut elbow in piping/tubing or raceway designs, or extension length on elbow in HVAC design.

The Instantiation Rule attribute is used during the instantiation (part placement) to know which behavior to apply. This attribute is an expected behavior.

HVAC Instantiation

During the instantiation of the object, a new attribute is valuated to store the reference mode as described above. The instance can be created from the original reference or from a duplicated reference. The Reference mode attribute is created on the HVAC instance and has two values:

  • Reuse: the new instance points the selected reference. This value is retrieved when the Instantiation Rule value is Reuse Reference or Reuse or New Reference.
  • New from: the new instance points the duplicated reference. This value is retrieved when the Instantiation Rule value is New Reference or Reuse or New Reference.

Impacted Commands

The behavior of some commands is modified according to the value of these two attributes.

The following commands are impacted:

  • Part placement: the Instantiation Rule attribute is used to apply the right behavior: instantiation or duplication. Only the rigid route with the instantiation rule equal to Reuse Reference or Reuse or New Reference can be placed.
  • Creation of Rigid Pipe/Tube: the Instantiation Rule attribute is used inside the panel that shows the reference of the rigid route. This attribute influences the behavior of the filtering. If the attribute is equal to Reuse Reference or Reuse or New Reference, the filtering is applied on the HVAC attribute. If the attribute is equal to New Reference, there is no filtering.
  • Adjust layout: for an elbow with the Reference Mode value equals to New from, this elbow is managed like a cut elbow and the bend angle can be modified with the adjust layout command.
  • Symmetry: the Reference Mode is used to know if the object must be instantiated or duplicated.
  • Ports: this command is available on port when the Instantiation Rule is equal to New Reference to allow the modification of port attributes.