This creator extraordinaire has built a gaming PC attached to a Victorian cast-iron radiator that is fully integrated into the cooling system, and I am in complete awe

Building my cast-iron radiator gaming PC - YouTube

I see custom PC builds pass through my newsfeed all the time, and my usual reaction is "meh". One I've been keeping an eye on for a while now, though, has finally reached its conclusion, and it's such an extreme build that I'm in absolute awe of its creation.

Billet Labs has released a video chronicling their efforts to create a custom PC integrated underneath a Victorian cast-iron radiator. That would be less impressive if the PC itself was merely strapped to the bottom frame, but no, it goes one step further. The radiator functions as the main heat exchanger for the cooling system, which means it's a fully-functional, liquid-cooled, steampunk-eat-your-heart-out gaming machine.

The unfilled radiator itself was initially estimated to weigh 50 kg, or as Billet Labs puts it, "catastrophically heavy". As it's a cast iron unit, it's also prone to internal rust, which proved to be a thorn in our intrepid builder's side throughout the project.

The goal initially sounds remarkably simple—build a high-spec gaming PC around an object designed to radiate heat away from its components, in a way that it can be used every day. However, the sheer amount of extra effort here is downright herculean.

The three-month project involved 3D scanning of the bottom of the radiator for component placement, which then led to the creation of a 3D-printed tray to hold the internals, integrating the system within the bottom loops of the radiator chassis itself. The components picked included a Ryzen 7 9800X3D, an RTX 5080, and 32 GB of RAM. Luxury.

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A radiator about to be turned into a custom PC by Billet Labs — (Image credit: Billet Labs)

However, when it came to the water cooling loop, things became even more complicated. Billet Labs fabricated a sequence of copper pipes with a built-in filter to hook up to the radiator's internals, in an effort to prevent internal debris from messing up the pump.

The radiator's existing bleed port was used for air removal purposes, although a custom T-piece system was created to allow the filling of the radiator and PC cooling system with water separately. This means the system itself can be removed from the loop without draining the radiator itself.

Break out the braising torch, I guess. The plumbing itself looks like some sort of steampunk nightmare, but appears to be remarkably well designed as Billet Labs breaks down its internal workings, complete with two pressure gauges mounted to the front side.

Cast-iron radiator water-cooled gaming PC build 9800X3D/5080/32GB - 99kg from r/PcBuild

As for the power button? Why, it's an antique brass gear lever of unknown origin, of course. It's all about the details, this project.

A major hiccup occurred, however, when filling the hybrid cooling system with 18 litres (!) of water after cleaning. The first attempt resulted in an eight-hour slog involving the chasing down of various air bubble problems. This, however, was merely the beginning of Billet Lab's issues.

Beyond the fact that the PC now weighed 99 kg (a quick bit of maths revealed that the initial radiator weighed roughly 80 kg, not the 50 kg initially thought), one of the fans caught on the shroud at startup. Then the pump began to click, because it was full of copper particles. A new pump (complete with more noises) suggested the system was full of air, which meant Billet Labs had to push the filled radiator around his home to remove potential bubbles. Which didn't work, so fittings were re-braised to eliminate leaks.

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A radiator PC under construction by Billet Labs — (Image credit: Billet Labs)

Then the CPU temperature spiked, which was caused by the filters clogging up with radiator debris. Which meant the addition of eight meters of hose attached to the build for draining and flushing purposes.

(Very) long story short, after much draining and cleaning, the PC now runs, albeit with quite a noisy pump thanks to the odd air bubble or spot of still-present debris. Some stress testing reveals decently low peak CPU temperatures of 68 °C in Cyberpunk 2077 with the fans off and the coolant temperature at an equilibrium.

But it's not about the end performance, as the result is a gaming PC with a truly unique cooling setup and aesthetic. After all of Billet Labs' troubles, I doubt many will seek to copy the design—but I'm glad there's someone out there still pushing custom PC builds to new and exotic extremes.

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Andy built his first gaming PC at the tender age of 12, when IDE cables were a thing and high resolution wasn't—and he hasn't stopped since. Now working as a hardware writer for PC Gamer, Andy spends his time jumping around the world attending product launches and trade shows, all the while reviewing every bit of PC gaming hardware he can get his hands on. You name it, if it's interesting hardware he'll write words about it, with opinions and everything.

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