If you are struggling to keep your Pi’s CPU cool, mounting a fan could be the relief you’re looking for. In this tutorial we’ll see how to connect a fan on your Raspberry Pi. After having completed this tutorial, the temperature of the CPU of your Raspberry Pi will drop drastically and always remain at an optimal level.
In contrast to the previous Raspberry Pi models, where overheating of the CPU was in most cases not really an issue. With the Raspberry Pi 4 B we have a completely different situation. Here the CPU gets really hot under normal load or even at idle. Because an effective heat dissipation solution is really critical for the Raspberry Pi 4, beside placing heatsinks, we advise to use well ventilated cases as our self-made 3D-printed case and / or mounting a fan. In most cases a well designed open enclosure will do the job. But for some applications with an intensive CPU usage, a fan is really helpful.
What you’ll need for this tutorial
- a Raspberry Pi board, of course 🙂
- a regular enclosure, a regular case with fan included or a case with SSD bay, suitable for mounting a fan
- a fan (30x30x7 mm), including the bolts and nuts
Mount the fan on the lid
Let’s see now how to mount a fan on our 3D-printed Raspberry Pi cases …
- Take the fan and turn it in such a way that you can see the label (on top).
- Take the cover part of the case and place it in such a way that the 4 legs are pointing toward the sky.
- Before placing the fan on the cover, position the 3 spokes of the cover in front of the spokes of the fan. If necessary, rotate the fan 90° as many times as necessary.
- Once the right position is found, clamp the fan onto the cover without using too much force. It should fit nicely.
- Double check the position of the fan by looking through the ventilation gaps of the cover. You should only see 3 spokes.
- Now you can mount the fan on the cover with the bolts and nuts as shown in the pictured below.
Connect the wires
Continue with the electrical part now. The fan can be connected to the 3.3V or to the 5V pin of the GPIO pins. Obviously, while the fan is connected to the 3.3V pin, it spins less quickly and the flow rate will be less important. But with this setup you almost won’t hear the fan spinning. For most cases, a 3.3V supply will keep your Pi perfectly cool. Depending on your needs, it’s up to you to choose one of the two options.
Have a look at the image below to see how to connect your fan to the GPIO-pins of your Raspberry Pi.
- Connect the black cable to any Ground pin.
- For the red cable you have the choice between pin 02 and pin 04 (5V) or pin 01 (3.3V).
Respect the colors of the wires!
Once the connectors in place, just mount the cover with the fan on the bottom part of the case.
Great! You’re done and your Pi will always keep cool from now on.
If you have connected the fan to the 3.3V, it is possible that the fan does not start to spin automatically at the very first start up. You can then give the fan “a little push” in counterclockwise direction with a small object. Normally it should start immediately then. If this does not work, you can first connect the fan to the 5V pin.
As long as your Pi is connected to the power supply, the fan will continue to run. Even after disconnecting the power supply, when reconnecting, your fan will start immediately to spin.