In general, heat is the enemy of electronics. [Christopher Barnatt] is serious about defeating that enemy and did some experiments with different cooling solutions for the Raspberry Pi 3. You can see the results in the video below.
A simple test script generated seven temperature readings for each configuration. [Barnatt] used a bare Pi, a cheap stick-on heatsink, and then two different fans over the heatsink. He also rigged up a large heatsink using a copper spacer and combined it with the larger of the two fans.
We aren’t sure if we would have used his methodology for these tests. The script executes quickly and it wasn’t clear that the temperature rise was leveling off. We weren’t sure just how much this was loading the CPU either. However, the results matched up with what you’d expect, so the script and data generation methods were probably fine.
The really interesting part to this wasn’t so much the results. We expected a bigger fan to do better and bigger fan and heat sink to do best of all. However, it was interesting watching the way the different cooling systems were mounted on the Pi and powered. The final solution — which was overkill anyway — was not mounted in a way that would lend itself to deployment. But the rest of the fan and heatsink combinations could easily be adapted for real projects.
If you really want to get serious, you can always plunge the Pi in oil. Or mount a thermoelectric heat pump and dump the excess heat into a bucket of water. But for most of us, just about any of the fan solutions here will be more than enough.