PyroSim 2013.1.0807 (Alpha)

Faster FDS modeling with professional results

Version: 2013.1.0807 (Alpha)

August 7, 2013

What's New

This is an alpha release for PyroSim 2013.

This release offers an incomplete preview of FDS 6 features that will be available in subsequent releases. New features include HVAC modeling support, an improved soot deposition model, and changes to FDS which improve the accuracy of gas flow modeling for a broad range of conditions. Additional extra species are now available and it is possible to transport, produce, and consume product species such as CO and soot.

If you try this version of PyroSim, even for just a few minutes, please visit the forum and share your experience or send an email to to let us know how it went (even if you found no problems).

This version of PyroSim is designed for FDS version 6 (includes a July 31, 2013 nightly build) and Smokeview version 6.11. It uses version 1.6.0_31 of the Java VM.


  • This is an experimental release and is intended for testing and evaluation only. The bundled version of FDS6 is a nightly build (not an official release) and future versions of PyroSim will likely not load PSM files created with this release.
  • FDS6 requires a reaction specification. By default, PyroSim uses a clean-burning propane. If you want smoke, you should use a reaction specific to the fuel or modify the default reaction to include soot as a byproduct.
  • This version does not contain graphical support for HVAC elements. Support is planned to be included in the official release. The HVAC model can be accessed via the Model menu.
  • FDS6 simulations tend to run slower than FDS5 simulations. Expect an FDS6 simulation to take about twice as long to run as a similar FDS5 simulation.
  • This version of PyroSim is not designed to support FDS5. FDS5 input files can be imported but not written by PyroSim 2013.

New Features:

  • PyroSim now supports FDS6.
  • PyroSim now supports HVAC input.
  • PyroSim can now import DWG and DXF files created with AutoCAD 2013.

Known Issues:

  • Aspirators incorrectly reference a species called "soot" which FDS6 does not recognize. This bug prevents models that use aspirators from running.

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