The Automated Duct Sizing utility adds specialized HVAC analytical capabilities. It includes preliminary centerline routing and performs resizing by optimizing route path duct sections. Best suited in 3D-routed duct system consisting of connected components, potentially with an air-handling unit and terminal devices. This utility brings enhancement over the past version tools for analyzing routes. It maps system and performs sizing algorithms, re-sizes and rebuilds system. The utility provides ability to edit system to coordinate layout and re-analyze to produce completed system and create part, fan sizing and pressure drop outputs. It demonstrates actual resize and component replacement by fetching the component types and fittings database and loading the duct sizing tables. The utility computes and lists the Velocity Pressure exiting "change-in-flow" or "change-in-size" components in the interactive tables.

The Automated Duct Sizing is an essential functionality included as part of an advanced BIM application required to compete in today's market. This capability uses a combination of the accepted algorithms to size duct based on the constant velocity and equal friction methods prescribed by industry standards such as ASHRAE and CIBSE. This workflow consists of allowing you to first route duct systems in a single line exercise to create a complete HVAC system, size the fan requirements and duct sizes and rebuild the system as calculated. The advantage of the Mechanical discipline approach will lie in the ability for the user to then edit the system so that it is designed to fit and re-run the system post edit through the sizing routines to maintain the system layout and report correct sizes, fan requirements and pressure drops through an installed system design. Reporting works well for components, pressure drop reports and equipment sizing.

Working in concert with the newly introduced single line layout capabilities, or with the existing 3D design capability HVAC systems can be loaded into the design tool to calculate system requirements and parameters. Fitting combinations presented in the ASHRAE Duct Fitting Database v 6.0 are being utilized to set up a correlation to path pressure drop values that can be derived directly from the database. Once calculations have been completed, air handling sources and such as fans and equipment can be resized in their capacity and the total pressure classification of the system can be determined.

Prior to loading the duct system for sizing, the system settings are done to set design data, define size criteria and reporting parameters.