CoolSim 5.4 changelog

CoolSim 5.4.180 preview 3

The desktop build of October 5, 2026, with 11 changes. It is built on CoolSim 5.4.180. A newer preview has replaced it on the preview download page.
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Changed

Can make a model solve to a different answer than before.

Energy files include every block’s heat load

The energy file sent with a job now adds up the heat load of every block and is written in full. Before, it stopped part-way whenever the room held a block without a heat load, and otherwise kept the heat of only one block. Energy results can differ from earlier versions. Model and airflow files are unchanged.

Removed

Python scripting

The script editor, the Python shell, the Python, Utility and PowerShell console tabs, and Edit Script are gone. Templates or import files that carry Python, and -run with a .py file, report Script Not Run instead of running it. CoolSim’s own built-in steps no longer use Python and write the same files as before. If you rely on your own Python scripts, write to support@coolsimsoftware.com.

New

A new 3D view

The model view is drawn with current web graphics (Microsoft Edge WebView2) in place of a 3D engine from 2011. The mouse and toolbar controls work as before. Two curved arrows over the view cube turn the view 90° left or right; in the top view, the tile row and column labels turn with the plan. Windows 11 and most Windows 10 machines already have the WebView2 Runtime; if the preview says it is missing, install it from Microsoft.

Improved

PDUs in models saved by CoolSim 5.3 export

CoolSim 5.4 stopped with an error while exporting such a model if the 3D view had not drawn the PDU yet, for example with Optimize load time on. The preview gives those PDUs their top and bottom openings, as CoolSim 5.3 did.

A supported library database

The object library runs on Firebird 5 in place of Firebird 2.5, which has had no updates since 2019.

  • The first start after installing takes about 10 seconds.
  • Library pages show every column. Columns with names longer than 27 characters were missing.
  • Adding parts works on Windows set to use a decimal comma.
  • The preview keeps its own index of library parts. It picks up parts added, changed or removed in your current CoolSim the next time it starts, which takes about half a minute. Your current CoolSim does not see parts added or removed in the preview.

The Reports tab says what fills it

A new project shows No report yet and names the two toolbar buttons that make a report, instead of a blank page or an Invalid window handle error.

Packages open in either version

Models and libraries packaged by the preview open in your current CoolSim, and the other way round. Opening a package never writes files outside its own folder.

A steady memory chart

The memory chart on the status bar no longer uses more memory each time it refreshes.
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Something working differently?

Tell us your CoolSim version and what you did. We’ll tell you which change it is, and what it means for your model.

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