A YouTuber known as der8auer has demonstrated that attaching a 3D printed chimney stack to a water-cooled CPU’s radiator can drop processor temperatures by 19°C without a single fan spinning.
The experiment applies the stack effect, a principle where hot air rising through a tube generates increased pressure that draws more air in from below. Der8auer tested the concept using modular 3D printed funnel segments stacked above a radiator, measuring temperature changes at each stage and using a smoke machine to visualize airflow.
Even a single segment produced a noticeable temperature drop. Adding a second segment created a visible draft through the smoke. The full stack delivered the 19°C reduction. The tradeoff is size: the complete funnel assembly gets unwieldy fast.
It’s not the first time the principle has been applied to PC cooling. Apple’s Power Mac G4 Cube used passive convection-based cooling in the same spirit, and SilverStone’s Raven RV02 case rotates the motherboard 90 degrees to align the board’s natural heat-rise path with the case’s top exhaust vents.
Der8auer’s hands-on test makes the physics concrete. Whether it’s practical for most users is another question, but the numbers show the stack effect isn’t trivial, even at desk-scale dimensions.
Source: hackaday.com
