Writing this from a passively cooled (Streacom FC8 Evo) Linux PC with a Russian keyboard.

    # dmidecode 3.6
    Getting SMBIOS data from sysfs.
    SMBIOS 2.8 present.

    Handle 0x002C, DMI type 27, 15 bytes
    Cooling Device
        Temperature Probe Handle: 0x0029
        Type: <OUT OF SPEC>
        Status: <OUT OF SPEC>
        Cooling Unit Group: 1
        OEM-specific Information: 0x00000000
        Nominal Speed: Unknown Or Non-rotating
        Description: Cooling Dev 1

    Handle 0x002F, DMI type 27, 15 bytes
    Cooling Device
        Temperature Probe Handle: 0x0029
        Type: <OUT OF SPEC>
        Status: <OUT OF SPEC>
        Cooling Unit Group: 1
        OEM-specific Information: 0x00000000
        Nominal Speed: Unknown Or Non-rotating
        Description: Not Specified

    Handle 0x0037, DMI type 27, 15 bytes
    Cooling Device
        Temperature Probe Handle: 0x0036
        Type: Power Supply Fan
        Status: OK
        Cooling Unit Group: 1
        OEM-specific Information: 0x00000000
        Nominal Speed: Unknown Or Non-rotating
        Description: Cooling Dev 1

So a cooling device is still present.

Sensor data:

    iwlwifi_1-virtual-0
    Adapter: Virtual device
    temp1:        +59.0°C  

    acpitz-acpi-0    # Fake, always reports these temperatures
    Adapter: ACPI interface
    temp1:        +27.8°C  
    temp2:        +29.8°C  

    coretemp-isa-0000
    Adapter: ISA adapter
    Package id 0:  +51.0°C  (high = +86.0°C, crit = +92.0°C)
    Core 0:        +51.0°C  (high = +86.0°C, crit = +92.0°C)
    Core 1:        +47.0°C  (high = +86.0°C, crit = +92.0°C)
    Core 2:        +49.0°C  (high = +86.0°C, crit = +92.0°C)
    Core 3:        +49.0°C  (high = +86.0°C, crit = +92.0°C)

> Streacom FC8 Evo

I normally think PC cases are gaudy and boring even when trying to evoke some style. That stuff in Streacom website however makes me want to build something with it.

LTT did a video with the SG10 a couple months ago. Really neat concept.

https://www.youtube.com/watch?v=iLHC2_gByQ8

Isn’t it just a smoother-looking typical industrial PC case? Always liked them though, too.

I am not sure what an "industrial PC" means. Inside, there are heat pipes connected to the CPU, and one side of the case (where these heat pipes lead) serves as both a heatsink and a surface with fins for convective cooling.

Industrial PCs are computers meant to go in industrial environments. They vary quite a bit but often have to handle dirty (possibly explosive or corrosive) air, 24v power, wide temperature ranges, lots of electrical and radio noise, and being cabinet mounted.

If you've got a little Node-RED box reading serial data from your bar code reader, doing lookups in your SAP database, and then sending Modbus commands to your PLC to redirect a box down a different conveyor line, it's probably an industrial PC.

Streacom makes fanless and air-cooled cases computers that aim to look good. Their products target an audio/video and enthusiastic pc building market. I would say they would be on the same category as Silverstone.

Yeah, that sounds quite different than industrial PCs, where the engineer specifying it spends 10 minutes pouring over specs and 2 seconds looking at the picture.

It doesn't need to be one or the other. It takes some engineering work to design something like https://streacom.com/products/db4-fanless-mini-itx-case/#fea....

Passively cooled PC probably won't work because the board will still have fan headers even if nothing is connected to them.

So we just need to implement the opposite of what OP has on our PCs, i.e. make OS think there are no fans.

Board vendors ought to start including a BIOS option to hide fans from DMI.

Yes and another method of controlling them.

External cooling device?

The computer knows there's a fan because it sees tacho output. If it doesn't see tacho, shrug. You can get an external temperature-controlled PWM controller for a few units of your local currency on AliExpress, steal 12V from somewhere (Molex header or whatever) and run the fans off that. Figure out where to put the temp sensor to get the desired effect.

There are far better ways to do this, but they require software engineering, not €3 and 15 minutes.

The computer knows there is a fan because it knows when there isn't a fan. By subtracting where there is a fan from where there isn't a fan, or where there isn't from where there is (whichever is greater) it obtains a difference, or deviation...

"because it knows when there isn't a fan"

How does the computer knows that? You mean the parts that can meassure temperature will meassure where it gets warmer, or where it doesn't get warmer, altough it should?

How does the system knows, it is not a local heat pipe, transferring heat away?

(the comment you're replying to is a meme - https://knowyourmeme.com/memes/the-missile-knows-where-it-is)

Ugh, and unfortunately, this meme makes perfect sense in this context.

This meme makes perfect sense in almost all contexts - at least continuous ranges are involved. I salute GP for fitting it for use with a discrete case.

The problem is not the fan, it’s the fan controller on the motherboard. I doubt a nonfancy fan controller will bother to drop off the bus/whatever if it doesn’t have fans connected, and the comment by 'patrakov upthread seems to confirm this.