Download of LoopCAD 5.0.380.80 was on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. Commonly, this program's installer has the following filenames: LoopCAD.exe and LoopCAD17.exe etc.
We recommend checking the downloaded files with any free antivirus. The actual developer of the program is Avenir Software Inc. You can install this PC software on Windows XP/Vista/7/8/10/11 32-bit. The software lies within Photo & Graphics Tools, more precisely 3D Design. The most popular versions of the LoopCAD are 5.0, 2.5 and 1.7.
From the developer:
LoopCAD is the premiere software for the fast creation of professional quality circuit layout drawings for radiant heating systems. LoopCAD offers advanced design features including integrated heating and cooling load calculations, detailed hydronic calculations, snowmelt design, 3D CAD views, and compatibility with OEM design methods and materials.
You may want to check out more software, such as LoopCAD 2014, which might be similar to LoopCAD.