So, no intake whatsoever?
No intake FANS.
If you just do the 3 exhausts as already mentioned, the air pressure will cause air to intake through all other open gaps. That won't happen if front fans are installed.
As crazy as it sounds, triple exhaust(rear, 2 top) only should bring in more air than if you tried triple exhaust + triple intake.
what do you mean by blower/turbo model
https://www.techpowerup.com/gpu-specs/asus-gtx-1080-ti-founders-edition.b4305
^A single radial fan at one end, which draws air in and rams it across the length of the card to expel it directly outside the PC.
https://www.techpowerup.com/gpu-specs/asus-rog-strix-gtx-1080-ti-gaming.b4311
^Open air cooler. Having 1, 2, or 3 fans to push air through the finstack, into the PCB, and is expelled at the sides, inside the PC.
the other day I was rendering a video purely using CPU and PC shut off due to over heating, which made me realize I need to figure something out with this cooling.
Hardware specs?
Besides being negative pressure focused, the H440 and its cousins have limits to how much power one can cram in them and still expect reasonable thermals. The higher system power consumption is, the harder it's going to be to resolve without replacing the chassis.