VE Application


Significantly reduce the time taken to draft and design ductwork systems and incorporate the sized system into your CAD drawings.



IndusPro can use the 3D building model from the Virtual Environment or 2D DXF CAD drawings as the background for drafting the ductwork system. Alternatively, the system can be drafted on a blank canvas.

Data entry and interface

Data Preparation

  • General system data, including design process, balancing option (using dampers only, or by resizing non-index runs), maximum design velocity, design pressure loss gradient and air properties
  • Customisable fitting data file, with data for each fitting type − how to draw it and connect it to ducts, and its pressure loss category
  • Standard or extended HVAC range, or a user-defined duct size range
  • Pre-definable list of duct parameter sets for easier data entry when editing the default duct or a particular duct in the network (e.g. type of duct, U-value, roughness)
  • Default data to be used during graphical placement – default duct, default fitting for each junction type, and default terminal
  • Duct data – predefined parameter set, sizing code (fixed size, maximum depth, maximum velocity, etc), optional fixed pressure losses, ambient air temperature, optional extra k-factor, flow diversity factor, etc
  • Fitting data – fitting type, plan rotation (if editable), dimensions (if editable), etc
  • Terminal data – as for fittings, plus air flow rate and pressure drop

Graphical Facilities

  • Graphical placement of ducts, using the current default duct, with automatically-assigned fitting types at each junction, using the current default fittings
  • Graphical placement of fittings and terminals, using the current default fittings and terminals
  • Duct networks can be drawn around a VE 3D building model, over a DXF drawing file, or on a ‘blank canvas’
  • The duct network can be drawn in any view (plan view, front view etc)
  • Ability to copy, move, edit and delete facilities on all graphical objects
  • Easy-to-use tool for connecting ducts to diffusers

Other Data Preparation Utilities

  • Diffusers may be placed in the model, either singly or as an array. A ceiling grid may be defined to aid this process

Analysis Options

  • Calculate the flow in each duct, taking into account diversity, from known terminal flows
  • Calculate circular-equivalent size according to the selected design process:
    • Constant friction – use maximum velocity to obtain initial size and then increase if friction gradient exceeded
    • Constant velocity – use defined velocity limit
    • Static regain – iterate sizes to produce a constant static pressure
  • Round the circular-equivalent size to an appropriate value based on the duct shape and the dimensions available in the range of standard sizes
  • After the main calculations, calculate the pressure levels in the system, using the fixed pressure losses and calculations based on the fitting pressure loss categories
  • Use design margins to calculate the final results
  • The analysis may be repeated with calculated sizes removed or retained for some or all of the ducts

Outputs and deliverables

Review options

  • Input data
  • Errors and warnings
  • Calculation results
  • Parts list, installed mass and material surface area
  • Output file containing all input data and results


Output includes the following:

  • For the complete system: fan total pressure, fan static pressure, fan flow rate, fan air power, installed mass of ductwork, identification of the index path and an optional list of parts. The fan duty is given for the specified operating conditions and for the standard conditions of air density of 1.2 kg/m3
  • For each section of ductwork: duct size, total k-factor based on input fitting codes, total pressure loss in the duct, pressure loss across balancing damper, velocity, temperatures and pressure-loss gradient
  • The ductwork graphics are updated to reflect the calculated sizes and the ducts are labelled with the sizes
  • Ductwork graphics can be exported in DXF format to any CAD system



  • Design and size air-duct networks for supply and extract systems.
  • Draft duct networks around a 3D building model, over a DXF drawing file, or on a ‘blank canvas’.
  • Choose the design process: constant friction, constant-velocity or static-regain.
  • Account for diversity in VAV systems.
  • Automatically account for duct-heat pickup and the consequent volume-flow changes through the system (for supply systems).
  • Choose to balance the system using dampers only, or by resizing non index runs.
  • Manually fix duct sizes for checking existing systems, or restrict duct sizes to defined limits where there may be space restrictions.
  • The ductwork system can be exported as a 2D DXF file for import into any CAD system.