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.
What's new in 26.2.0715
This release of PyroSim has some powerful new features and improvements to existing capabilities. Download the new version to work more efficiently with CAD geometry and Mesh Refinement Zones! CAD Quality Adjustment For many years, PyroSim has supported importing CAD geometry. However, users do not always have access to concise models with relevant geometry. Often, there are many CAD objects that complicate and slow down PyroSim. PyroSim 2026.2 delivers CAD adjustment features that enable more efficient modeling workflows: - On import, you can specify Object Quality (See the Creating Geometry from CAD page). This reduces the number of triangles used to represent imported geometry. - After import, you can perform a similar operation upon any selected imported geometry. The new context-menu action allows users to Simplify Imported Geometry.
Figure 1. Simplifying Imported Geometry
Best of all, you can set imported geometry to be ignored in an FDS simulation.
Figure 2. Display Only Use this action to set an object in the model to Display Only and it will not be used in the FDS simulation. Generic Geometry is not converted to OBST or GEOM entries, but are available in Results (when PyroSim Geometry is active). Mesh Refinement Zone Enhancements PyroSim 2026.2 enhances the Mesh Refinement Zones workflow. - This update adds a filter to preview the meshes resulting from refinement zones in the Model View, called Show Mesh Refinement Preview. This adds two new filters to the Mesh filter toolbar.
Figure 3. Using Show Mesh Refinement Preview
Expanded support for nested Mesh Refinement Zones makes them easier to use on building models with floor geometry.
Figure 4. Nested Mesh Refinement Zones
Also, Meshes in the Object Tree now display the optimal level of information about effects of mesh refinement.
Figure 5. Nested Mesh Refinement Zones with tree info When put all together, these changes make it easier to complete your individual workflow and work efficiently with Meshes in PyroSim 2026.2. Complete the updated example to experience these changes. Control Value Devices Users can now cleanly use math controls as inputs to other activation control logic, a long sought after feature.
Figure 6. Editing Activation Controls
Now, Math Control output values can be written to a CSV file and also may be used as numeric inputs for other Mathematical and Custom Controls.
This will also help users work with Statistics Devices. …
PyroSim 2026 can open or be associated with 4 file types:
.pfr.psm.smv.smvv
PyroSim 2026 version history
26.1.0211
User Experience Improvements PyroSim 2026.1 delivers meaningful user experience and stability improvements aimed at creating a smoother, more efficient modeling workflow. Expanded support for additional keyboard shortcuts helps users work faster and more intuitively, while updated warnings provide clearer feedback during model setup. Stability has been improved during scenario creation, reducing interruptions in complex projects, and major OpenGL updates have enhanced rendering stability, resulting in more reliable and consistent visualization performance. Results Changes Results handling in the new PyroSim release has been enhanced to better support common analysis workflows and reduce manual setup. 3D Smoke results are now automatically activated when available, allowing users to immediately visualize smoke behavior without additional configuration. In addition, CSV results data can now be auto-loaded, streamlining access to numerical output and making it easier to review, plot, and post-process simulation results directly after a run completes. You can read more about the changes to Results in the Results Documentation. Documentation Improvements The 2026.1 release includes a major overhaul of the product documentation, focused on making information easier and faster to access. …
26.1.0121
User Experience Improvements PyroSim 2026.1 delivers meaningful user experience and stability improvements aimed at creating a smoother, more efficient modeling workflow. Expanded support for additional keyboard shortcuts helps users work faster and more intuitively, while updated warnings provide clearer feedback during model setup. Stability has been improved during scenario creation, reducing interruptions in complex projects, and major OpenGL updates have enhanced rendering stability, resulting in more reliable and consistent visualization performance. Results Changes Results handling in the new PyroSim release has been enhanced to better support common analysis workflows and reduce manual setup. 3D Smoke results are now automatically activated when available, allowing users to immediately visualize smoke behavior without additional configuration. In addition, CSV results data can now be auto-loaded, streamlining access to numerical output and making it easier to review, plot, and post-process simulation results directly after a run completes. You can read more about the changes to Results in the Results Documentation. Documentation Improvements The 2026.1 release includes a major overhaul of the product documentation, focused on making information easier and faster to access. …
Frequently asked questions
Is PyroSim 2026 free?
PyroSim 2026 is proprietary software from Thunderhead Engineering. Check the publisher's license terms for pricing and usage rights.
What is the latest version of PyroSim 2026?
The latest version is 26.2.0715.
Is it safe to download PyroSim 2026?
The download button links to the official installer published on thunderheadeng.net, the same file Windows Package Manager installs. You can verify the downloaded file by comparing its SHA-256 checksum with 4781a5958ad3471c0b00e42ffaf5ab2b8a640802b2bd5f6c202b15b0ed598a09.
Which Windows versions does PyroSim 2026 support?
PyroSim 2026 runs on Windows and is available for 64-bit (x64) systems.
How do I install PyroSim 2026 silently?
Run the offline installer with msiexec /i "PyroSim-2026-2-0715-x64-en.msi" /quiet /norestart, or install it with Windows Package Manager: winget install --id=Thunderhead.PyroSim.2026 -e --silent.
How do I uninstall PyroSim 2026?
Open Settings › Apps › Installed apps, find PyroSim 2026 and select Uninstall. From the command line, run winget uninstall --id=Thunderhead.PyroSim.2026 -e.
Chocolatey is The Package Manager for Windows. It was designed to be a decentralized framework for quickly installing applications and tools that you need. It is built on the NuGet infrastructure and
Dell Command Update is a stand-alone application for systems that provides updates for system software that is released by Dell. This application simplifies the BIOS, firmware, driver, and application
