if you're using amazon.com/dp/B077R5BVVR/ removing just the outer enclosure and removing that fan should be safe, but it might not be the loudest fan...
otherwise the quietest PC is the one in a different room, but you probably already know that
That's exactly the one I'm using, thanks! I was considering the fan, but I've also been worried about torching my house. I'll give it a shot.
I put some work into the frame the cluster is in, and it makes a pretty nice end table. My main pc is a little fanless industrial computer and I love it.
otherwise the quietest PC is the one in a different room, but you probably already know that