Simulation error

Hello, I changed the model to make it closed polysurface and when importing to simscale i dont get any faults anymore so thats good. I went back and added empty openings on the walls for airflow, and imported the model with openings into simscale again, i got some minor faults related to sheet. In order to provide natural ventialtion i need to include inlets and outlets.

  1. How can I put empty openings on my model on simscale?
  2. If there’s no way to make openings on simscale, what other options are there to fix the issue with ‘sheet’?
  3. How can I show on simscale that my openings are there for airflow?