The new Raspberry Pi 4 is significantly more powerful despite sharing the same small form factor as its predecessors. With great performance, however, higher power consumption. The Raspberry Pi 4 therefore generates much more heat than the older Pi models. Without active cooling, the Raspberry Pi 4 will thermally accelerate even under moderate loads. Fortunately, this can be fixed by creating or adding a fan to the official Raspberry Pi 4 case.
Note: there is a lot of 3rd party Raspberry Pi 4 cases with fan on the market. This tutorial is for DIY enthusiasts who already own the official Raspberry Pi 4 case.
This is a fairly straightforward mod that doesn’t require any expensive tools that you wouldn’t already find in an average household. Some optional extras have been listed and marked accordingly. They are not absolutely essential, but they are nice to have. The extras may cost a bit more, but they will make your job easier while improving the aesthetics as well as the performance of your Raspberry Pi 4.
Click on each item to find links to recommended products on the Amazon store. The different variations and subtle nuances of each of these tools and supplies will be explained in detail during the course of this guide.
- Raspberry Pi 4 Model B
- Official Raspberry Pi 4 case
- Electric drill
- Hole saw kit or brad point drills
- Rotary tool
- Or a 30 mm or 40mm case fan (5 volt, 2 pin versions)
- PVC dust filter for case fans (optional)
- Double-sided tape (thin)(optional)
- Perforation kit (optional)
- Raspberry Pi 4 copper radiator kit (optional)
- Sandpaper (optional)
- Ruler and markers
- Protective glasses
- Isopropylic alcohol
Active cooling of the official Pi 4 case
Our first task is to drill a fan hole just above the processor.
1. Familiarize yourself with the case by installing the Pi 4 inside the case. Determine the general area where the cooling opening can be drilled in the top (white) half of the case. Be very careful not to touch the GPIO pins, otherwise the case will not close with the fan installed. The illustration below can be used as a guide, but it is better to measure twice and cut once.
2. This is where you need to decide on the dimensions of the fan. You can choose between a 30mm or 40mm fan. A larger 40mm fan pushes more air at a lower speed, making it quieter and more efficient. The smaller 30mm alternative spins faster and is noisier, but is more compatible with other premium aluminum Raspberry Pi cases. This is something worth considering for future upgrades.
The fan depth can vary between 6mm and 20mm for the scope of this mod. The blades of a thinner fan have a relatively smaller surface area compared to the thicker alternative, which reduces cooling performance. A thicker fan can also accommodate a more powerful motor. Just make sure to avoid using a heat sink (not recommended) or installing one with a profile low enough to accommodate the thicker fan.
3. A set of hole saws is the cleanest way to make the fan hole. You will need the 1-1 / 4 inch drill attachment to make an opening for the 30mm fan or the 1-1 / 2 inch one for the 40mm fan. If you do not have access to the correct size hole saw attachment, you can drill several holes using a large attachment point drill bit to achieve a similar effect. However, this will not allow about the same airflow as a hole the size of a suitable fan cut using the hole saw.
4. Cut a piece of cardboard or foam to fit inside the enclosure as shown below. This will prevent you from inadvertently drilling a hole in the lower half of the chassis (red) after drilling the upper half. It is not possible to drill the fan opening with the bottom half of the housing removed as this makes it difficult to secure the housing while drilling.
5. You can secure the cabinet using anything from duct tape to a bench vise. It is absolutely essential that you do not use your hands to hold the case steady or leave it unsecured. The torque generated can cause the drill or the housing to slip and cause serious injury. In the images below you can see my improvised method of securely securing the case with wood and pliers.
6. Most modern drills have variable speed control and an analog trigger. Use them to prevent the drill from turning at high speed. Slowly start the hole saw and gently squeeze the trigger until the bit bites into the housing. Once the bit is through, make sure the previous hole saw gently bites into the housing and makes it perfectly straight. Do not drill too fast, otherwise the excessive heat generated will warp the case. Use the fan as a template to mark and drill four holes. These mounting holes will be used to secure the fan to the case.
7. We need to create another opening on the long side of the case, right in front of the audio / video and power ports. This opening will increase the cooling efficiency by ensuring good air circulation in the otherwise sealed housing. Make sure to keep the length of the opening less than the distance between the pair of adjacent mounting points on the inside.
You can do this with a rotary tool such as a Dremel or by drilling a series of holes using a large bit with a fixing tip. Use 320 grit sandpaper to clean the openings. You can skip this step if you don’t feel like going out of your way to smooth the edges. Clean the two halves of the housing.
8. (Optional) It is recommended to protect the Raspberry Pi 4 from dust. Cut a fan-sized sheet out of the mesh of the PVC dust filter. Use an appropriately sized hole punch to make the fan mounting holes. Use the supplied mounting hardware (nuts and bolts) to secure the fan to the top half of the housing, with the dust filter sandwiched in between.
9. Repeat the procedure for the other opening along the side of the chassis adjacent to the GPIO pins. It is best to use a thin double-sided tape to stick the dust filter to the case.
10. We are now clear to install the Raspberry Pi 4 in the lower half of the case. Next is the installation of the optional heat sink. Installing copper heat sinks on critical components not only improves cooling performance, but the added thermal mass also allows for more sustained overclocking. What’s the point of having such problems if you don’t want to overclock it?
Most heat sinks come preinstalled with 3M fabric tape for mounting. You can identify it by its jet black finish when you remove the protective label (image below). Do not install heat sinks with this black fabric tape. Ironically, black tape is an insulator that will negatively affect cooling performance. Thoroughly clean the fabric strip with isopropyl alcohol and use Arctic or 3M thermal adhesive pads 8810 instead. the Raspberry Pi 4 copper radiator kit included in checklist of items previously shipped preinstalled with 3M 8810 iron-on pads.
11. Install the heat sinks on the dies for the processor, RAM and network as well as the USB controllers. Apply moderate pressure to the heat sinks for 15-20 seconds to achieve proper wetting and adhesion of the heat pads. Connect the two-pin fan cable to the GPIO pins (red: 5v and black: ground) as shown in the pinout diagram above paying attention to the polarity. (Red is positive and black is negative.)
Relax with an active cooling SBC
Turn on your Raspberry Pi 4 Model B and you will notice that video playback is smoother. The processor will not overheat or slow down during demanding applications, improving actual performance. At stock settings, my Raspberry Pi 4 remained stable below 50 ° C even under moderate loads. With the active cooling setup in place, I even managed to overclock my Pi 4 to an impressive 2 GHz.
Is this article useful?