Hardening PCs for Hostile Environments?

labradore asks: "I must install a 1.2GHz Athlon system, in a secure place, at a retail business. The PC is going to be a security video recorder and a point of sale terminal server. In other words I need it to act like an appliance: something that requires very little on-site maintenance and at most, remote adminstration. Unfortunately the only secure place to put it is inside a hot, dusty storage room. It has it's own protective lock-box (approx. 3x3x3 ft.) to keep evil employees and snooping types out and to insulate it from the heat and dust of the storage room but I don't know how to actually keep the box cool and fairly free of dust." What things would one need to house comodity components in such a way to enable them to survive in such hostile environments? Is 27 cubic feet too small for the necessary modifications that would have to be made?

"There must be a lot of other people turning PCs into "embedded" controllers or appliances facing the same situations. At the very least this could be thought of as the quest for the ultimate "fire-and-forget" cooling environment. What options has the collective mind of Slashdot uncovered and thunked up to deal with this kind of situation?"

Comments

Simple solution

[kneecap]

Under-clock the processor, and use filters on the fans pulling air in. This will work for a mildly hostile environment. Perhaps using multiple 120mm fans and washable filters, then you might be able to get away with a room tempurature 90F (32C) degrees. If the tempurature is going to be higher than that and the air dirtier than filters can handle, then you would need to take more extreme measures.

My OEM style PC with an Athlon 1100 is doing fine in my apartment without air conditioning. It has not had any problems with the room tempurature being in the high 80s. At work we had the air-conditioning for the NOC fail for part of a week end, the tempurature was in the low 90s when we got in there. Nothing crashed and we have not seen any problems with any of the dozen Sun servers nor the few Cisco Routers since then. It was not something I would desire to repeat though.

Re:Simple solution

[The Blue Daisy]

I regularily use my PC with an abient temperature of 32C+. Thats inside my living room. The temp outside is usually much higher. Humidity is usually around 80% and there are a couple of bakeries nearby, so the air has a lot of particulate matter in it (flour, ash, dust etc). I've had no real problems yet...

I think you underestimate the reliability of modern hardware.

Oversized Aluminum Case + fans

[Bryan Andersen]

Get an oversized Alumimun case and mount many fans inside it blowing every which way but out. Seal the case up tight. On the outside, have a bunch of fans blowing air over the sides and top of the case. Some friends are using this on a computer that is outside. The case internal air temp runs about 10 degrees above ambient. The CPU they have is only a K6-2-350. If you need more cooling, you can mount large area AL heatsinks on both sides of a case wall and direct fans over them. One thing to remember is cooling air wants to go down and air warming up wants to go up. Take this into account when placing fans otherwise it will take alot more fans to get the job done. www.Aavid.com has many large area heatsinks. Some large enough to serve as a side wall for the case.

Alumunum is a very good heat conductor. All the better heat conductors cost much much more to use. Look into using a copper CPU heatsink to better transfer heat away from it, but check the overclocker sites to really find out which heatsink is the best bang for the $$$ you are willing to spend.

I'm looking at having to make a PC for outside use in the near term future. I'm going to make it's case out of large area AL heatsinks. I'll be using a heat pipe to transfer the CPU's heat to one side, and use a dual sided heatsink on the other side to cool the rest of the components. Items like hard disks will be directly mounted to the side walls to provide better heat conduction. The idea is I want to make it so it doesn't need fans at all. It needs to run off of solar and batteries only.

Cool cabinets from Blackbox

[thewiz]

There is a company called Blackbox that sells all sorts of lockable cabinets for computer systems. You might want to check out their ClimateCab and ClimateCab Desktop products. I've used these with great success in dirty and hot environments. They are NOT cheap ($4,686.95 and $3,564.95 respectively) but they are the best that I've found that include security, filtration, and cooling.

Industrial

[topham]

There is a reason industrial PC's are so expensive. They are designed for harsh enviornments. I would strongly recommend one. They are hideously expensive compared to your standard PC though.

Remember, it is your ass on the line when the PC fails because the environment is too harsh for it.

Sealed box and A/C

[Matt_Bennett]

If it is truly a dusty environment, and you want to keep the maintainence low, seal the box. You can get Peltier junction A/C units- not very efficient or quiet (because of the fans), but they do have the advantage of allowing a sealed box. This one will remove 550 BTU/hr. You don't need to keep it cold, just remove enough heat so that the computer doesn't fry itself. There will be some leakage of air into it- no big deal, but because of it, you will need some way to get rid of the water that condenses on the cold side of the junction- your periodic maintainence will have to include some sort of dessicant, or at least making sure the drain holes are clear.

Put it in a fridge

[cameloid]

That way, you can have a couple of beers when you (inevitably) have to fix it. The second bonus is that your beers will be *real* cool if the uptime runs into decades ^_^

No cheap way out.

[kachuik]

Comodity components do not last in "harsh" places. We just expect them to fail. As long as they are under warrenty, we call the supplier for service. As soon as something goes bad when it's off warrenty, it gets tossed and replaced with a new machine. This only applies for those things that can be down for day or so. For the rest, it's the expensive industrial PC's with built in cooling and/or seperate cooled rooms and filtered air.

It all depends an how long the user is willing to go without.

A home brew method....

[GreyPoopon]

OK, here's a home brew method that hasn't been tried by me, but I believe would work.

You have two problems, dust and heat. Enclosing the unit within a cabinet won't really keep either out. But you CAN solve both problems at the same time. Put the unit into an enclosed cabinet. Have the customer purchase a small chiller with filters, which will probably have to go into a separate (hopefully less dusty) location. Funnel the output from the chiller through some ductwork, and run the other end through a small hole in the cabinet. And presto, you have a positive pressure, cooled environment for your hardware. The cooling takes care of the heat, and the positive pressure keeps the dust out. Hopefully, holes in the cabinet for cables, etc will be enough to keep the pressure regulated, but if not, you can always add some additional small holes. And, BTW, I've seen some chillers that are only about 1 foot deep, 2 feet high and 2 feet wide.

DISCLAIMER: I do not warrant the above information in any way, nor will I accept responsibility if it fails or creates other damage. Use at your own risk!

GreyPoopon
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Dust-proof Cooling

[John Hasler]

Bolt large heatsinks to both the inside and outside of one side of your lockbox (strip the paint off first). Install a fan inside blowing air over the heatsink. If possible install another fan outside blowing air over the outside heatsink, and if possible replace the steel between the heatsinks with aluminum. This technique is used in some military equipment.