Facing the Heat (a Raspberry Pi article)

Lately, I've been working with my new SBC (single-board computer, a euphemism for the tiny computer I've bought to learn more about hardware and stuff). Although my experience overall has been a mixed bag, I learned a lot about this tech and the various engineering aspects of this sort of machine. For example, did you know that this machine (something valid for most other computers out there also) has a temperature sensor? I'd expect that from a full-sized computer but not from a little bugger like this. Of course, once you measure something then you start thinking about how this temperature (which is probably related to its CPU) affects performance and other factors of relevance. And that's when you realize that this machine wasn't built for high temperatures unless, of course, you want to use it as a mini-over to heat some pastry or to keep your coffee warm!

Handling the heat a tiny computer produces isn't a simple task. Many hobbyists and more seasoned professionals have come up with various strategies for cooling their Raspberry Pis. If you don't do that, the machine throttles its CPU to prevent the meltdown that would ensue if no action were taken. Throttling seems like a wise move but it translates into poor performance and potential wear and tear, since it just prevents the temperatures from rising higher, or maybe drops them a bit. During normal operation, my RP4 tiny computer would experience temperatures of a bit over 60 degrees Celcius. Although this is within its operational parameters (the RP4 can withstand temperatures of up to 85 degrees C, or 140 degrees F), it’s not ideal. After all, these aren’t the best electronic components in the world so keeping them heated up is bound to shorten their life span considerably.

You can accomplish heat management in various ways, the most popular (and effective) of which, for most RP4 users, are heat sinks and fans (or even a combination of both). Although this seems like a fun project, if you've already shelled 100 Euros for this device, you may be less inclined to order more accessories for it, especially given that their effect, although significant, isn't all that much. At least for the heat sinks, which seem to be the optimal choice. Of course, a heat sink's effect is bound to be a sunk venture if you keep the casing of the RP4, which is excellent at keeping all the hot air trapped within it. So, if you are to use a heat sink (or a fan), you need to keep the top of the casing off (which makes sense since this time of year, many people roam the beaches topless anyway!).

Of course, there are other, more creative ways to cool the RP4 device without investing in a specialized device. I'm not talking about water-cooling or oil immersion (both of which are known methods used by the most extreme Raspberry Pi enthusiasts). No, I'm talking about something more efficient, which can help you kill two birds with one stone. Namely, why not use a laptop fan, which is already cooling down a laptop, to cool the RP4 too, with its outgoing air? 

"But, doctor, it's warm already, isn't it?" I can hear you say (OK, maybe without the "doctor" part, but hey, heat affects me too!). That's a good point, but the air stream of the output of the laptop fan is measured to be around 30 degrees (maybe a bit higher at times, but never more than 40). As a result, there is still some heat capacity in those air particles that would otherwise crush on the wall, wasting all their potential. Since there is some room between the laptop fan and the wall, I might as well put that RP4 device there and see what happens!

Preliminary tests over some time whereby the tiny computer was pushed a bit (running an HD video on VLC while I played around with some other tasks on the terminal) were promising. The temperature never rose beyond 43 degrees, while at times, it was even less than 40 (especially when idling). Of course, additional tests will need to be done before I can draw reliable conclusions, but it's fair to say that this PoC project has been successful. Now I need to find a way to face the heat that affects us all in this macro-oven that is the city where I live. Wish me luck!