Guidance on PI4 cases and fan


I have a PI 4B that I am running as a Home Assistant hub. I have it housed in an Argon NEO case, and have moved the HAOS from the SD card to an external SSD. I’m investing some more effort on HA and a couple of questions have come up that I’d love some advice on.

I was worried it might be over-heating, so ordered the Argon Fan HAT which has arrived today. The installation instructions say to install the HAT by opening Terminal in Raspbian. However, I’m not familiar with doing this in a HAOS environment. Can anybody provide me some advice?

Secondly, while researching this, I discovered a comment that suggested that using the fan HAT in the Argon NEO was less useful because of the plate that covers the Pi. Would an Argon ONE be a better case? Other suggestions?

Finally, if I went with an Argon ONE, would I be able to use the Argon ONE M.2 Expansion Board and an M.2 SSD instead of the external SSD to boot the PI under HAOS?

Please note, while I am IT person with 40-years’ experience, this gear is all fairly new to me, so some of the above may appear to be “dumb questions”!

Thansk in advance.


Highly recommend the Argon One V2 and M.2 Expansion Board.
Mine boots of the M.2 board and runs nicely, the metal case gets warm to touch but the Pi 4 remains within the temperature range. The power on off switch at the back works well to shut it down nicely and keeping all the cables at the rear is good.

Getting the M.2 board to boot was easy enough if I remember correctly.

Cannot help with HAOS running from the M.2, no experience in that area.

All the best

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Thanks James. Hopefully somebody else will be able to help with the HAOS, but good to get that recommendation on the case and M.2.


Was the system running > 65degC? Generally 40-65degC is a pretty safe area for a CPU to operate within.

Here’s a short guide that shows you how to log CPU temp


Hi Michael

Thanks for that information. As I am running HAOS rather than Raspbian, I don’t see the same command line prompts (which is why I was asking earlier about the way to install the HAT). But it did prompt me for an idea.

I was able just now to get the same information using a HomeAssistant Add-on. It’s running at 48.7 °C, which is obviously okay. The fan HAT is physically installed and running (but not properly configured yet).

This all started the other day when I noticed some “outages” (ie HA wasn’t responding) and I noticed the Argent NEO case was quite warm. The A/C wasn’t on in the study where the unit was. Hence the decision to add a fan. Probably unnecessary, but isn’t this the point of tinkering? :grinning:

Anyway, thanks. I suspect I am sort of stuck in some limbo between Raspbian and HAOS!


Hey it sounds like things just got a bit simpler then @DavidOD - in any case best of luck with your project :smiley:

Home automation is not for the faint of heart :grimacing: we’d love to see your project updates here, and if you feel like you want to share instructions for other consider posting a project.

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Yes indeed - one step forward, 2 steps back!! And linux/unix commands were never my strong suite.

I’ve managed to Terminal into the HAOS CLI, so we will see. But it won’t let me run the installation sh file. I suspect I won’t have access to the Raspbian commands.

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I found that there were add-ons for Home Assistant to help with getting it all working. There were two required:

  1. HassOS I2C Configurator provides the necessary ability to make HAOS able to talk to the fan. This replaced part of the installation process.
  2. ArgonOne Active Linear Cooling provides controls for the Argon ONE and NEO fans. THis provides access to the equivalent of the Argon configuration tool.

I now have the fan running when necessary.


Nice, @DavidOD :ok_hand: that’s good docs for anybody looking to do the same in the future