Thanks a lot for this @minggangyin, your debuged file was very helpful, whit that I can see that one of the problems was the geometry of the zones the model I´m working (convex surfaces to be specific). Once that fixed I just have to add a new assign hvac system components to the canvas and goes ok.
However there is an issue that not worked in my working model but in the simple box geometry example goes well. For my working model the simulation doesn´t start with the error “Calculation would require division by zero” when I assign some plenums zones. At the end I can´t assing plenums. But for the simple boxes goes well.
Here my working model.
Lomond House NZ vForum.gh (802.3 KB)
Maybe the issues come from the complex geometry of plenums?