NIST Multizone Modeling Website
Ducts
As an alternative to the simple air-handling system, CONTAM allows you to model HVAC systems using detailed duct systems. Duct systems are made up of duct segments, junctions, terminal points, and forced air components. A duct segment is a section of a duct between any two junctions, terminal points or combination of the two. A terminal point is an endpoint of a duct segment, and a junction is the connection between two duct segments. Only horizontal segments can be displayed on the ContamW SketchPad, but vertical segments can be implemented as well. Vertical segments are connected with special junctions and terminal points that reveal the location of the vertical segments on the SketchPad. You draw the layout of the duct system, and ContamW will insert junctions and terminal points where appropriate. Once you have drawn a duct system, you must define the drawing by providing detailed segment, junction and terminal point information. You must provide each duct segment with specific information that describes the flow characteristics and physical dimensions of that segment. Much of this information is in the form of duct flow elements that you must create when defining the duct segments. CONTAM 2.4 provides the ability to perform an automated duct balancing procedure based on user-defined design flow rates at duct terminals.
Duct Flow Elements
Each duct segment must refer to a duct flow element. Duct flow elements describe the mathematical relationship between flow through and pressure drop along the duct, the flow resistance or forced flow characteristics, cross-sectional geometry, and optional leakage per unit length of a duct. ContamW provides you with several different mathematical models or element types to choose from. Each of these duct flow element types is described in detail in the Duct Segment Properties section. While every duct segment must refer to a single duct flow element, multiple duct segments can refer to the same duct flow element. Duct flow elements can also be stored within a CONTAM library file and shared between different CONTAM project files.
