System Types

The System Types page defines project-wide system design parameters: a system description for reports, the duct types available for duct layout, and the register criteria used to select registers for each space type.

Central and terminal unit equipment is configured per system in System Design > Configuration, not here.

System Description

A free-text description of the project’s HVAC system approach. This appears in reports such as the Basis of Design.

Duct Types

Duct types define the sizing criteria HVAKR uses when sizing ducts in the Duct Layout pane. Click Create Duct Type to add one.

Properties

• Name - Descriptive name (e.g., “Supply Trunk”, “Low-Velocity Branch”)
• Max Pressure Drop - Maximum friction rate, in inches of water per 100 feet
• Max Velocity - Maximum air velocity, for noise control
• Max Height - Maximum duct height, for fitting within plenum space
• Liner Thickness - Duct liner thickness, which reduces the free area
• Color - Display color used when rendering ducts on sheets

When sizing a duct, HVAKR picks the smallest size that satisfies all of the duct type’s criteria at the duct’s design airflow.

Register Criteria

Register criteria are set per space type and control how supply, return, and exhaust registers are selected during Air Balancing. For each of supply, return, and exhaust you can set:

• Register Model - The register product model to use
• Max Flow Rate - Maximum airflow per register
• Max Velocity - Maximum face velocity
• Max NC - Maximum noise criterion rating

Best Practices

1. Use separate duct types for mains and branches - Branches typically need lower velocity limits for noise control
2. Set realistic height limits - Match the available plenum depth
3. Set NC limits by space type - Noise-sensitive spaces like conference rooms need lower NC ratings