A PC enthusiast has taken custom PC liquid cooling to an extreme level by routing their system’s coolant loop outside the house to a radiator placed in the winter air. The project, shared on Reddit, serves as a proof of concept for using ambient outdoor temperatures to keep high-performance hardware cool while avoiding the risks of condensation.
Outdoor Radiator Setup
The build centers on an Nvidia RTX 4070 Ti Super and an Intel Core Ultra 7 270K Plus processor. The user installed a Bykski water block on the graphics card and a Thermal Grizzly 1851 Micro Pro water block on the CPU after delidding the chip. These components are connected in a custom loop that can divert coolant through holes in the wall to an external radiator when additional cooling is required.
The primary motivation for the mod was to reduce heat in the gaming room. The user noted that their room becomes uncomfortably warm during extended gaming sessions. With outdoor temperatures dropping to -4 degrees Celsius, the setup aims to utilize the cold air for free cooling. However, the system is designed to keep the water above the dew point to prevent moisture from forming on the electronic components.
Automated Temperature Management
Managing the flow of coolant between the indoor loop and the outdoor radiator requires precise control. A secondary computer system handles the logic, running a Python script that starts with the PC. This script communicates with an Arduino board to monitor temperatures and adjust the pumps accordingly.
The Arduino integrates with HWiNFO and Fancontrol software to provide total oversight of the system’s dynamics. The code ensures that the coolant remains cold enough to dissipate heat effectively but warm enough to avoid condensation. Water dripping on a high-end graphics card is a significant risk, so the automated system prioritizes safety over maximum cooling potential.
Performance tests showed the setup keeping the GPU at approximately 48 degrees Celsius under load and the CPU at 52 degrees Celsius. During gameplay of Counter-Strike 2, the GPU temperature dropped to 34 degrees Celsius, while the CPU stayed between 45 and 50 degrees Celsius. The user stated they are aiming to improve these numbers further to compete in the Steel Nomad benchmark for the RTX 4070 Ti Super.
Source: PC Gamer
