A computer in a dusty environment (factory)

If your system has to work in a dirty industrial environment then commodity PCs are probably not the way to go. You would be much better off using machines that have been designed for use in those kind of environments. You would be better off researching industrial fanless or sealed PCs or similar. They probably wont be cheap but they should work flawlessly in your kind of environment for years.

Googling "industrial pcs" or "industrial pcs nema" will get you a bunch of results for suppliers of more robust PCs.

Keep in mind that you get what you pay for - lower-end models or cheaper suppliers are really just putting a regular PC in a tougher-looking case. Adding NEMA to the search gets you suppliers that make truly sealed units, even ones that are waterproof.

I always wanted to try one of those "Dirt Bag" things for a few of our PCs that were on a shop floor, but never got around to it.

I built something like this:

• Passively-cooled Intel Atom motherboard
• Passively-cooled Pico PSU (would need to grab the power brick too)
• Well-vented case

Might be worth it if you're on a budget ($70 + $50 + $40 = $160 sans ram and hard drive). Even if it was completely filled with dust, you could just blow canned air into one side of the case and the dust would fly out the other