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Faster FDS modeling with professional results

Model dynamic fire simulations in detailed 3D to accelerate and enhance your fire protection analysis.

Are hand calculations and text-driven design holding you back?

Building geometry from scratch is expensive.
Designing models from only text files is error-prone.
Producing results without advanced tools takes too long.

View PyroSim Features

Elevate fire protection engineering to the next level.

Import CAD geometry

Import the architect's model in seconds. Automatically detect BIM data and generate fire-model-specific geometry. Easily understand and navigate your model.

Design simulations graphically

Build in an application tailored to avoiding errors and mistakes. See your model as you work and easily investigate details through intelligent UI.

Manage simulation assets

Control your CPU processing capabilities to optimize simulation time. Maintain multiple simulation configurations for sensitivity analyses.

Deliver professional results

Put the worries of an AHJ to rest. Answer all of their questions with unprecedented clarity by creating plots and videos with advanced controls and information overlay.

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Documentation and tutorials ready to help you advance

Start delivering better results now

  • Download now
  • Learn with Documentation
  • Improve with Tutorials
  • Deliver results

FDS + PyroSim

Model a safer world

PyroSim was designed to complement the Fire Dynamics Simulator (FDS) developed by NIST in the US. With state-of-the-art fire research facilities and personnel, they understand the calculations of fire simulation better than anyone.

FDS is the engine powering fire simulations all over the world. PyroSim empowers more engineers to use this technology and elevates its capabilities.

  1. PyroSim provides graphical tools which automatically generate the text-only FDS input file.
  2. PyroSim imports CAD, enables advanced simulation management, and packages its own results manager.

None of this is possible without FDS empowering car park jet fan simulations, sprinkler activation studies, and more.

FDS is free for anyone to download. Do you need PyroSim? We think so. Consider the time not spent constructing your building geometry from scratch in a text editor. Consider the errors caught in real-time and brought to your attention.

Thunderhead Engineering supports you every step of the way. Whether you want in-depth training or self-taught materials, you can learn performance-based design modeling with greater efficiency and proficiency. We design our software for anyone to learn, and our customers are delighted when our support team helps them succeed.

We believe PyroSim will quickly win you over. Try it free for 30 days - complete and unrestricted.


License types to meet your needs, no hidden fees

We don't hide our pricing behind an email list. Click below to see for yourself.

Trusted by experts around the world

Contact our International Partners for assistance in your region.

Leading design firms
International Partners
Years of Updates
Trusted by experts around the world

PyroSim and Pathfinder allow our team to streamline our model builds, use unique techniques and approaches, and provide clean and concise output data. The software saves us time through many of the powerful features, which translates to both cost and time savings to our clients.

Thumbnail Image of David Stacy
David Stacy
Principal & Founder, Performance Based Fire Protection Engineering, PLLC