Hi, Have you already checked out this tutorial, involving solar load? https://www.simscale.com/docs/tutorials/thermal-comfort-meeting-room/ On a side note, I don’t think that setting up this aluminum cover as a porous media would allow it to block any radiation. If you had solar load off, you could have set an actual solid as “semi-transparent” part, but it sounds like you need solar load, so this wouldn’t work. If you actually captured the cover’s shape (e.g. like a perforated plate of sorts, or any other shape that it has) it might also do the trick. This is of course assuming that it’s not an extremely complex shape. If you use a porous media, you will always get 100% transmissivity through the cover. Cheers