Download of Combisun 1.1.3.62 was on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. This free program was originally developed by European Solar Combisystems.
The software lies within Education Tools, more precisely Science Tools. We recommend checking the downloaded files with any free antivirus. Combisun is developed for Windows XP/7/8/10/11 environment, 32-bit version. The default filename for the program's installer is CombiSun.exe. The most popular version among Combisun users is 1.1.
From the developer:
A PC-tool for performance estimation of combisystems. The PC-programme can estimate the performance of a number of different combisystem designs, under different climates and different loads. Conditions and Problems to Be Aware of When Integrating Solar Combisystems in Buildings
You may want to check out more software, such as Panel, gitoolbox or roboBASIC, which might be related to Combisun.