I'm wiring my new home, and I have a camera system (BNC but looks like a stero cable in diameter) and ethernet cables that I've run to the attic space. Everything was going great until summer hit, and the temps in the attic started to become too hot for the routers. I want to move them into a closet, so my plan is to just drill a hole in the ceiling and drop the wires down. There are quite a few, 27 cables that I need to route.
My question is, when I make a 4" hole in the ceiling that goes directly to my attic, will that cause issues with my heating and cooling? Is there a way to prevent that?