Question PC Cases [AIR-TIGHT vs AIR-FLOW]

[BTBuilder]

Building a pc case to suit tough environments means looking at case building from a whole new perspective.
One of the best concepts I've seen yet is a rather large case tested by Linus Tech Tips.
It used a very conventional flow through system with some very unconventional extras.
Basically it turned the box into a horizontal pipe or tube, with 2 x 180mm high capacity air intake fans at the front covered by a downwards directed vent cover and pushing the air through a large HEPA filter the size of the front panel.
This gives the rest of the case a positive air environment, forcing everything else out of the case, including water (though I would not suggest submerging - it did give the case a fairly impressive IP43 rating).

So why this discussion?
Simple is there a better solution. I'm interested more in the theory so get creative and draw on some of all this new/old technology we keep hearing so much about.
Look forward to all the suggestions, esp' all you DIY'ers out there.

BT Builder

 

[hotaru.hino]

This thing?

To answer "is there a better solution?" requires more answers from you. What requirements are you looking for? You could probably achieve something like an IP67 or IP68 rating, but you're basically sealing the case up at that point, which you now have to rely on using the case itself or use some sort of other external cooling mechanism.

Which Linus also covered, sort of

You could conceivably seal this case up from the elements completely such that all of the electronics won't have a problem with dust or water.

However you have a problem now: your I/O isn't watertight. Sure you could probably make something like a watertight connector that plugs directly into the I/O on the motherboard (which I've seen in some outdoor military equipment), but you can't hot plug anything at that point. Actually, heck, just look at military equipment in general, because they're meant to survive working in everything from desert dust to rain storms.

 

[Karadjgne]

Start with the basics. Electronics do not need air. At all. The only thing that's necessary is cooling.
Technically, if you turned the case panel into a giant passive heatsink, that'd suffice to cool the cpu/gpu, especially in colder climates. Could even use liquid transmission.
Downward pointing, covered i/o like on the back of many monitors solves dust/rain issues.

 

[BTBuilder]

This thing?

To answer "is there a better solution?" requires more answers from you. What requirements are you looking for? You could probably achieve something like an IP67 or IP68 rating, but you're basically sealing the case up at that point, which you now have to rely on using the case itself or use some sort of other external cooling mechanism.

Which Linus also covered, sort of

You could conceivably seal this case up from the elements completely such that all of the electronics won't have a problem with dust or water.

However you have a problem now: your I/O isn't watertight. Sure you could probably make something like a watertight connector that plugs directly into the I/O on the motherboard (which I've seen in some outdoor military equipment), but you can't hot plug anything at that point. Actually, heck, just look at military equipment in general, because they're meant to survive working in everything from desert dust to rain storms.

Yes i/o is a potential problem tho if rly necssry, wireless option's could be implemented for most conceivable requirements.
I definitely like the completely passive case is a heatsink line of thought. You could change the whole construction of a case with this in mind.

 

[kanewolf]

So why this discussion?
Simple is there a better solution. I'm interested more in the theory so get creative and draw on some of all this new/old technology we keep hearing so much about.
Look forward to all the suggestions, esp' all you DIY'ers out there.

Yes, an "industrial PC". Solid finned aluminum chassis. The case is the heatsink for the entire device. No fans.

 

[Silas Sanchez]

Generally speaking when i see someone spraying water at a PC what comes to my mind is click bait, fooltube, popular gimmicks, and blind masses who watch it.

The problem with passive cooling vs active/air cooling is the process is so inefficient. Air molecules interacting with a heatsink is very efficient, diffusion is a truly relentless extremely fast process that further leads to convection (due to buoyancy forces) and this does wonders for cooling while drawing only 5-10watts per fan. This is the wonderful consequence of the second law of thermodynamics.

The other problems are the difficulties in transferring heat, its hard to heatsink motherboards for example. The amount of surface area that the heatsinks would have with the main parts would make it impractical for anything but low power htpc type of computer.

Finally, the real insidious problem is moisture and humidity which are a significant problem for corrosion. Which is hard to keep out and requires things like conformal coatings on boards, potted electronics and anti corrosive grease on all electrical contacts.

 

[beyondlogic]

Yes i/o is a potential problem tho if rly necssry, wireless option's could be implemented for most conceivable requirements.
I definitely like the completely passive case is a heatsink line of thought. You could change the whole construction of a case with this in mind.

If you take the time you could go a step further and make a passive heatsink with a vapour chamber

 

[Eximo]

There are a few off the shelf full passive chassis out there that use heatpipes to get the heat to aluminum chassis radiators/side panels. Generally only work with moderate level hardware though.

None really made it to market that I am aware of. But there were also entirely vapor pressure based pumpless 'water' coolers.

I don't see why a dense water cooled brick of components with a shielded optical thunderbolt cable coming out of it couldn't be used. Then you would only risk peripherals.

But I agree, the typical solution for general use is something like a depth rated toughbook, the problem has been solved for field/military use.

 

[Karadjgne]

The other problems are the difficulties in transferring heat, its hard to heatsink motherboards for example. The amount of surface area that the heatsinks would have with the main parts would make it impractical for anything but low power htpc type of computer.

Other than a few specific components like memory and chipsets etc a motherboard doesn't really require heatsinking because it is a heatsink. That's the primary purpose behind the design of the ground plane, the motherboard doesn't require such a large plane when simple traces connected to a single buss would be sufficient for grounding purposes, but the ground plane acting as a heatsink is entirely different.

3 major heat sources in a laptop are cpu, gpu and battery but there's only 2 major sources of cooling. The fan and the case, which is why laptop coolers do nothing more than siphon heat from the case.