You were on the right route to getting your issue solved. When you join all of your polygon surfaces together and use the dupborder command, you should be checking to see the number of borders that get produced. If it is more than 1, then you have a hole in your model. Here is how I checked for the hole in you model:
Note that the hole can be really small and I had to deselect the outer border with Cntrl+left click and use the “zoom selected” command to find your very tiny gap here:
To get rid of the gap, I deleted out the aluminum surface next to the hole, joined all of the polygons together, ran a dupborder command, and used the curve around the seleted aluminum surface to build a new surface with the PlanarSrf command (this ensures no gaps). Then I brought all of the new aluminum geometry into GH, connected it up to the THERM components, and it ran the export component without and issue. When you open the file in THERM, you will sometimes get the following message:
In this case, you should ignore it at take the default option (Mark the points but don’t adjust them). The reason why this error happens is just because there are no other CAD plugins for THERM and the software still freaks out whenever it recognizes that the geometry has not come from its own interface. After you simulate, you can bring your results back into Rhino/GH like so (and see attached):
I know that this seems like a lot of clean up work but trust me that this is far less than what it used to be when you had to build models from scratch in the THERM drawing interface.
ThermSection_CWM.gh (628 KB)