Experience with sound dampening wanted

Hi all

I just received this super nice little gadget. It works great and hums along… Well more like hisses along, loudly.
I suppose it’s acceptable in a noisy environment, but for when I’m using it at home, I would like to enjoy the movies without focusing on the fan noise in the quiet parts of the movies.

Does anyone have a good idea as to how a sound dampening projector box could be made that would allow for a nice airflow and removing most of the sound? It can be quite bulky, that is not a problem…

Like a polystyrene box with rockwoll or… I mostly know about insulating heat, not sound :-/ Help!

Best regards