A fanless mini PC lives or dies on three things: how much heat the chassis can shed, whether the I/O matches the machines you talk to, and how it mounts inside the cabinet. Start with the CPU class — an Intel Core i5 at 28 W needs roughly twice the heatsink surface of a Celeron, so the same chassis can be silent at 35 °C ambient with one and throttled with the other.
1. Match the I/O to the machines
Legacy PLCs and meters still speak RS232/RS485. Count the serial ports first, then USB, then display outputs. Our F17H keeps two COM ports and six USB for exactly this reason, while the F28 trades legacy ports for triple 4K output and 2.5 GbE.
2. Respect the temperature envelope
Specify the worst case, not the average. A cabinet in a steel plant reaches 55 °C in summer; a −20 °C to 60 °C platform such as the K8-F24 keeps margin where a commercial 0–40 °C box will not.
3. Decide mounting early
VESA, wall and DIN-rail kits change the board layout. Ask for the DIN-rail bracket at the quotation stage rather than retrofitting it later.
Need a shortlist? Send us the ambient temperature, I/O list and volume and we will match a platform the same working day.