PC modder der8auer built a 110 cm [1] 3D-printed chimney to passively cool a Ryzen 7 9800X3D CPU without using fans.
This experiment demonstrates that natural convection can effectively manage processor heat, potentially reducing the reliance on power-hungry and noisy active cooling systems in specific computing environments.
The project utilizes the stack effect, a phenomenon where warm air rises due to buoyancy, creating a pressure difference that draws cooler air in from the bottom. By extending the cooling path vertically, the modder created a natural draft that carries heat away from the hardware more efficiently than a standard open-air setup.
According to tests conducted in July 2026 [5], the vertical structure significantly impacted thermal performance. The CPU temperature dropped by 19 °C [2], though some reports describe the reduction as almost 20 °C [3]. This temperature decrease was achieved entirely through passive means, meaning no electricity was used to move the air.
The 110 cm [1] tower serves as a physical conduit for the air. As the Ryzen 7 9800X3D generates heat, the surrounding air warms and ascends the chimney, which pulls fresh, cooler air across the heatsink. This radically simple modification proves that the geometry of a PC case can be as critical to thermals as the cooling hardware itself.
While most modern high-performance CPUs require active fans or liquid cooling to prevent thermal throttling, this project highlights the physics of natural airflow. The result is a silent system that maintains lower operating temperatures than a standard passive configuration without the mechanical failure points associated with fans.
“The CPU temperature dropped by 19 °C [2], though some reports describe the reduction as almost 20 °C [3].”
While a 110 cm tower is impractical for standard consumer desktops, the experiment validates the 'stack effect' for thermal management. It suggests that future industrial or specialized PC chassis could incorporate strategic vertical venting to reduce energy consumption and acoustic noise by leveraging natural convection instead of mechanical fans.
