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 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 an 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 or a case with SSD bay, suitable for mounting a fan
• a fan (30x30x7 mm), including the bolts and nuts

If you’re missing some hardware, don’t hesitate to visit our shop : www.freva.com/product/raspberry-pi-4b-case-with-fan/

Or if you are looking for a housing with an SSD bay and where you can also mount a fan, this link will help you further: www.freva.com/product/raspberry-pi-4b-case-with-ssd-bay/

Mounting the fan

Let’s see now how to mount a fan on our 3D-printed Raspberry Pi case… Take the fan and turn it in such a way that you can see the label (on top). Take also 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, you can 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.

The same type of fan also fits perfectly on the lid of our housing with SSD bay:

Now it’s time to fix the fan on the cover with the bolts and nuts as shown in the picture above.

Connecting the wires

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 the fan won’t make almost no noice. Depending on your needs, it’s up to you to choose one of the two options. The image below shows which wire has to be connected to which GPIO-pin of your Raspberry Pi. The black cable can actually be connected 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!

Or for the case with SSD bay :

Once the connectors in place, just mount the cover with the fan on the bottom part of the case.

Note: If you have connected the fan to the 3.3V, it is possible that the fan does not start to run 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 now connected to the power supply, the fan will continue to run. Even after disconnecting the power supply, when reconnecting, your fan will start immediately.

Great! You’re done and your Pi will always keep cool from now on.