Pi4 DIY Heatsinks?

Question

Just got a Pi4 for a project and noticed that it got hot within a few minutes and that's before I've even put it into a case. Has anyone done a DIY heatsink? Can I reuse something from an old PC? Are all the chips electrically isolated and at the same physical level? I also want to use an audio hat with this, so am looking for tips for extending the 40pin GPIO header.

koudelad · Answer

Hello Andy, Are you looking for a passive cooling only? In my experience, if you add a 5V 4x4 cm fan, it can work even without a heat sink. (However I still recommend one.) The fan can be powered even from a 3,3 V rail, resulting in lower RPM and noise. An aluminum heat sink of any size on the CPU will lower the temperature, but even a small air flow lowers the temperature drastically. If you want to add other hat(s), a low speed a 8x8 cm or similar sized fan could be mounted from the side. David

mp2100 · Answer

Well, this is what I did, definitely DIY

https://www.element14.com/community/community/raspberry-pi/blog/2019/07/11/raspberry-pi-4b-runs-hot

As you can see I used an old Intel PC heat sink. But there is definitely limited area for it. The Pi4 CPU is a bit taller than the other chips, so the heat sink sat on it without touching anything else. But I had to cut it’s width and length to make it fit within the Ethernet port, and more important, not touch the pins. If I had a ceramic heat sink, I would have used it, so prevent any chance of shorting something. Aluminum has worked well though, the heat paste holds it, and with the top of the Pi case on there, it won’t touch the pins.

I’ve been running it since July continuously with no problem, using it as my daily internet surfing computer. And the CPU temperature is much lower.

Workshopshed · Answer

So I had a little block of aluminium and I drilled some holes in it and joined them together with a saw. I'll give it a test in the week to see how much heat it dissipates.