Australian Modder Repurposes Industrial AC Radiator as Extreme PC Cooler
A hardware enthusiast known as TrashBench salvaged a 4-kW air-conditioning radiator to build a custom water-cooling loop, achieving dramatically lower GPU and CPU temperatures on a high-end test bench.
The Australian hardware modder TrashBench has struck again with an unconventional cooling experiment. Following his previous success with unconventional GPU placement, he decided to tackle a much larger project: integrating a discarded 4-kW outdoor radiator-fan assembly from a split-system air conditioner into a custom water-cooling setup for his PC test bench.
To prepare the industrial cooling unit, TrashBench stripped it down to its essential components—the radiator, fan, and pump—removing unnecessary internal parts and adding casters for mobility. He then installed a standard water reservoir into his main enclosure. On the PC side, he fabricated custom 3D-printed mounting brackets for the cold plates and modified plumbing connections to fit his system.
Testing began with an RTX 5060, a power-efficient GPU that normally runs at 52°C with its stock cooler. Connected to the 4-kW radiator system, temperatures plummeted to 33°C—a 16-degree reduction. When TrashBench overclocked the card from 2902 MHz to 3300 MHz, the boost yielded only a 3% improvement in average frame rates, demonstrating Nvidia's well-optimized power-to-performance scaling since the RTX 2000 series.
The RTX 3080, a significantly more power-hungry predecessor, presented a tougher thermal challenge. Its temperature dropped from 65°C to 28°C—barely above ambient conditions. Overclocking this card similarly produced only a 3% fps gain, suggesting thermal headroom rather than performance limitations.
The final test combined GPU and CPU loads using an Intel Core i9 14900K, widely regarded as one of the most thermally demanding consumer processors available. CPU temperatures fell 18 degrees to 76°C, a substantial achievement outside of specialized cooling environments. The RTX 3080's temperature remained unchanged, indicating the radiator possessed far more cooling capacity than TrashBench's hardware could generate.