Pool-Cooled Gaming PCs Get Gross: Solving Algae and Corrosion

The Pool Cooling Problem

• 💡 The initial vision of heating a pool with server rack waste heat evolved into cooling computers, but this led to significant issues.
• ⚠️ A past incident involved corrosion and water damage, requiring grounding and an isolation transformer.
• 🤢 Months later, the system developed organic growth (algae) in the reservoirs, accompanied by a foul smell.

Disassembly and Cleaning

• 🛠️ The team disassembled the gaming PCs to clean the cooling blocks and address the organic growth.
• 🦠 A silver coil was added to the loop, historically believed to have antimicrobial properties, to combat the microbes.
• 💧 New 10-micron filters were installed in both the indoor and outdoor loop filter canisters to catch accumulated gunk.
• ⚠️ It was discovered that the CPU blocks were not symmetrical, leading to incorrect flow direction in some systems.
• 🤢 Disassembled blocks revealed significant organic buildup but, importantly, no new corrosion.

Addressing the Growth

• 🔬 UVC lights, specifically in the 253 nm wavelength, were employed to disinfect the coolant by damaging microbial DNA and RNA.
• 🚀 Drop-in UVC cleaning systems were used, which circulate coolant through an enclosed UVC exposure chamber.
• ⚙️ The team also focused on correctly orienting tubing on barbs to prevent loosening over time and addressed issues with worm drive clamps.

Results and Conclusion

• ✅ After a week, the indoor loop showed significant improvement, with clearer coolant and less visible gunk.
• ✨ The outdoor loop also cleared up considerably, with the coolant becoming much clearer, allowing visibility to the bottom of the reservoir.
• 🧐 The filters showed some collected material, with the outside loop's filter being more visibly dirty, suggesting it was more affected.
• 🤔 The solution to the problem was attributed to a combination of filtration, silver ions, and UVC treatment.