We have been dealing with the Raspberry Pi in its many variants since the first version. The subject of “housing” has not been the focus so far, but is gaining importance with the model 4. Because the current Raspberry is a small radiator.
The visually appealing housing from Flirc is solid and offers good passive cooling for the Raspberry Pi 4.
The Raspberry Pi has made a significant leap in performance since it was first introduced. So can he
provide energy-efficient central server services in the home network. A suitable case is a must if the little arithmetic servant is to run reliably. A solution with passive or active cooling technology is recommended for continuous operation.
Why you need an enclosure
At first glance, the environment may be impressive when the self-made NAS consists of a jumble of cables and hard drives. However, this state should only survive the period of a function test. After that, a case is not only tidier: you also extend the life of the small computer if you protect it from dust. Because it lies like a blanket on the CPU and memory chips and hinders the exchange of heat. A housing also protects against accidentally triggering a short circuit.
Convinced? The search for a case quickly leads you to the official case of the Raspberry developers with a vanilla-raspberry look. However, this housing is made of plastic, which does not dissipate any heat. With this or a similar case, you can solve the problem of dust and short circuits, but take the board out of the air to breathe.
To check the temperature, all users of an Android smartphone can use Raspi Check. It monitors one or more boards in the home network. To do this, the Open SSH server must be activated in the Raspberry system. The IP address or host name and the access data for the SSH user are stored once in the app. You can then take a look at the temperature diagnosed by the device at any time.
The temperature of the Raspberry Pi 4 should be checked more frequently when the load is high. You can do this via SSH in the terminal as well as with an Android app.
Cool circuit board, cool performance
If you search for images on the Internet using the keywords “Raspberry Thermal”, you will find many photos from thermal imaging cameras that show the impressive temperatures of the circuit board, especially the central processing unit (SoC). The Pi itself clocks down automatically at a temperature of 85 degrees Celsius. Temperatures below this value are no problem, anything above more or less fatal. A Raspberry 4 draws around six watts under full load. That doesn’t sound like a lot, but it’s impressive. If the board then serves as a NAS or printer server, the components for USB and WLAN also heat up. Roughly simplified, the SoC heats up more in relation to its size than the stove top of your ceramic hob in the kitchen. Do not you believe? Then divide the 2000 watts of the stove by the area of the small plate that is eight inches in diameter. Then compare it with the six watts of the Raspberry, divided by the area of the approximately 1.4 centimeter central unit.
Passive cooling uses the physical principle of heat conduction. In short, “heat” always flows in the direction of a lower temperature. The larger the contact area between the heat source and the larger the temperature difference, the more heat can flow away. Aluminum offers high conductivity, and housings made from this material are robust and temperature-resistant. Two-part constructions are usually offered in specialist shops: The circuit board is firmly connected to the lower shell with special screws. The upper part of the housing is used to dissipate heat. A pin protruding from the upper shell establishes the connection to the SoC.
Housing with passive cooling:
The aluminum case from Flirc provides reliable service in various projects for us (approx. 21 euros). The Geekworm model has also proven itself in practical use. The simple Geekworm aluminum case starts at around 13 euros. If you want, you can install the Raspberry in a NAS-like housing for a good 60 euros (Geekworm NASPi). There is no shortage of other alternatives in specialist retailers. In any case, it is best to use reviews or a review of the scope of delivery to check whether the case actually fulfills the tasks set. In the case of particularly inexpensive imports from China, the supplied adhesive pads, which are intended to improve heat transfer to the housing, are nothing more than carpet adhesive tapes. They adhere well, but do not dissipate any heat.
Geekworm NASPi: This expensive solution (over 60 euros) turns the Raspberry into a mini NAS. A simple aluminum case is available from Geekworm from around 13 euros.
Putting the Raspberry in a passively cooling metal housing is a very promising idea from the point of view of heat dissipation. However, there is one problem that must not be overlooked. Since the Raspberry Pi has no separate antennas for receiving WiFi, the housing can interfere with WiFi reception. Metal housings are therefore only the first choice where WLAN is not required.
Active cooling for high performance:
The passive and silent cooling that can be achieved with a high-quality housing should be sufficient for most scenarios as a home server. However, if the circuit board runs continuously under full load or other components provide additional heat, then passive diffusion may no longer be sufficient. Then an active fan is needed that simply blows the heat away, what the physicist calls “convection”. Most of the heat is removed with an aluminum housing that also has a fan.
Here, too, the trade has countless models ready. But be careful: The product descriptions tend to give the impression that everything you need is in the box. the astonished customer then wonders when the promised fan is missing. The Argon One housing (approx. 26 euros) is high-end, solidly manufactured plus the option of accessing the GPIO pins from the outside. It combines active and passive cooling. The case, started as a Kickstarter project, looks good and leaves the board cool even for particularly demanding tasks. A clear recommendation on our part.
The above selection is based on the typical home server: The Raspberry provides its services in a closed room without expansion boards. If you use the Raspberry as a streaming client for the stereo system and a DAC has been plugged in, you need a housing that leads the connections of the piggyback board to the outside and can handle the waste heat. Here you should opt for models made of metal and heat sinks.
Other special cases are missions in the great outdoors. Apart from the power supply, in these cases you also have to deal with the moisture problem, i.e. look for housings with a corresponding IP protection class.
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The Argon One case is slightly more expensive than simple plastic cases, but is cooled with an active fan.