The idea that going fanless is better should be something of a given at this point. The removal of a point of failure whenever possible is a net gain for Systems Administrators and Manufacturing Engineers — even before you get into the matters of dust and particulate in the air. However, what’s interesting is what happens after you remove the fan. Are your problems with dust solved? Certainly you are better off, but is dust still getting into your systems and wreaking havoc? Let’s look at what is in your dust, how it can still get in your cases, and what you can do about it.
What is in Your Dust?
There is an old Urban Legend that says 90% of dust is made of up of skin particles. Gross. Thankfully that is just a myth. The reality is our dust is made up of whatever is in your environment. Are the materials in your environment greasy, conductive or corrosive? So is your dust. We did an informal survey of IT professionals and engineers in manufacturing sectors and asked them to rate the dust level in their environment (Low, Med, or High), as well as give any special notes. While broad, we can begin to see some patterns.
Two cases in particular stood out: a paper mill with overheating problems and a steel factory with short circuiting motherboards — both with fanless systems
At the paper mill, the pulp was thick in the air, thick on the floor and thick on the mother board. It ended up acting like a blanket holding in the heat in their fanless thin clients. As you can imagine, this caused more than a few failures.
At the steel mill, tiny bits of metal collected in every little corner despite ambitious cleanup methods. Inside their fanless thin clients and monitors no such cleaning was even attempted. The result was bits of steel laying across circuit boards, causing system failure after system failure.
Both mills had a similar level of dust, both had problems with particulates on their mother boards – though with different effects — and in both cases they had fanless systems (Full disclosure, they were not Logic Supply units). So why wasn’t going fanless enough?
Case Design 101: Vented vs Sealed Chassis?
One of our in-house experts Rodney Hill — mechanical engineer and chassis designer — broke it down like this, “The more holes you have, the more stuff gets in.”
After a chuckle, he went on to explain system design, as it pertains to ruggedness in a graph. “A common error is thinking that a standard fanless terminal can withstand airborne dirt and dust. Dust is the carrier monkey for metal filings, dust, sulfur and other corrosives that will eat the board, and other conductive material that will beat up the electronics. Even though many systems are fanless, their vented design lets particulate in where it can damage the printed circuit boards.”
In the case of the steel and paper mills, they had made the move to fanless and reduced failures associated with moving parts. However, given the volume and type of dust in their environments, they failed to fully deal with the problem. The venting slots on the thin clients (the same models in both cases) allowed air in, and with the air came what was in it.
Brass Tacks: What You Can Do About Dust
The pie in the sky option is to keep your systems, even the fanless ones, away from the worst of the particulate. However, too often a PC needs to be right there on the front line. Killing the fan is key, but if your dust is corrosive, conductive, sticky, or worse, the very air can hurt your system. What can you do? Kill the vents too.
On the scale Rodney outlined above, case design is an active part of the ruggedness of a system. When your fan and moving parts are gone, the next step is locking your system off from the dust. A fanless enclosed case can solve your particular particulate problem.