Your Raspberry Pi is designed for passive cooling, just like your smartphone and most other devices that utilize an ARM processor. Under normal conditions, the processor runs cool enough that the heat dissipates without the need for a fan. But that doesn’t mean you can’t add active cooling. We usually see that in the form a case fan, but YouTuber Rasim Muratovic took it to the next level and water cooled his Raspberry Pi.
It’s unlikely that you’ll have any reason to do this, but it could be useful if you’re doing some crazy overclocking on your Raspberry Pi. But you’d most likely do it because it just plain looks cool. If you’re not familiar with water cooling, it’s a way to help dissipate processor waste heat using liquid, and is normally only used for supercomputers and high-end gaming rigs. The liquid is channeled through tubes and across the processor heat sink, and moves through a closed system to cool.
The heart of this build is a Syscooling SC-300T water cooling pump, which does the actual work of moving the liquid around. That flows through tubing and goes to an Alphacool MCX One heatsink that’s usually used for graphics cards or RAM modules. That heatsink is attached to the Raspberry Pi’s processor and carries the heat away. The tubing then continues to a large heatsink with a fan mounted to dissipate the heat. From there, it continues back into a small container that holds the liquid. It’s almost certainly overkill, but Muratovic likely has the coolest Raspberry Pi in the world now.