One is the chimney effect: the claim that a case works like a flue, and that pointing your top fans outward gives hot air a natural boost on the way up. A chimney works because that rising air is trapped inside a tall channel, so as it climbs it drags cool air in behind it through the bottom. der8auer ran the math on a case 55 cm tall, assuming a 20°C room and a 40°C interior, and landed on 0.4 Pascal. His test rig ran a custom water loop around a Ryzen 7 9800X3D, capped at a constant 100 watts so the heat entering the loop stayed the same throughout. Onto that stalled radiator, der8auer began stacking 3D-printed PLA shrouds.