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New Approach To Immersion Cooling Powers HPC In a High Rise
miller60 writes "How do you cool a high-density server installation inside a high rise in Hong Kong? You dunk the servers, immersing them in fluid to create an extremely efficient HPC environment in a hot, humid location. Hong Kong's Allied Control developed its immersion cooling solution using a technique called open bath immersion (OBI), which uses 3M's Novec fluid. OBI is an example of passive two-phase cooling, which uses a boiling liquid to remove heat from a surface and then condenses the liquid for reuse, all without a pump. It's a slightly different approach to immersion cooling than the Green Revolution technique being tested by Intel and deployed at scale by energy companies. Other players in immersion cooling include Iceotope and Hardcore (now LiquidCool)."
Waiting for a watered-down version for the consumer space.
Using a boiling liquid is asking for trouble. True, a phase change like boiling can conduct away a lot of heat, but there are other issues. First of all, vapour does not conduct as much heat as liquid, so there's going to be an insulating layer of vapour over all of the components that need it most. It's called the Leidenfrost Effect. Second, bubbles expanding and collapsing causes an effect called cavitation, which can erode components. It is a constant sonic vibration which can induce metal fatigue in delicate wires (such as the leads inside a chip), and can cause cracks in inflexible materials such as silicon chips and ceramics (capacitors and resistors).
When our name is on the back of your car, we're behind you all the way!
TFA doesn't say exactly which 'Novec' heat transfer fluid they use; but all of them have enthusiastic vapor pressures even at 25 degrees, and low boiling points. The devices shown in the pictures (unless specially opened just for the glamor shots) also don't look particularly well sealed.
How do they deal with that? Does the 3M guy follow the milkman every morning, and deliver another couple thousand liters? Is there a chiller/condenser somewhere in the air circulation system that scrubs most or all of the escaping vapor? Are the racks normally sealed tight?
I, again, couldn't get any solid quotes for medium-large quantities of the heat transfer fluids; but fancy fluoridated-carbon engineered fluids aren't generally cheap enough to just ignore large losses of. Boiling may well be more efficient than pumping as a heat transfer method at the board level; but I'd be amazed if they can get away with running this as anything other than a closed loop, despite the pictures seemingly showing otherwise.
Anybody know?
http://www.pugetsystems.com/submerged.php
I always thought this was a cool idea, albeit pretty messy. But this company will sell you a "case" (a modified fish aquarium) and the components to go into it. They also have some specs on how well this thing cools.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
...the bad guy will point his gun at the server room, threatening to shatter the glass case with the server cooling liquid in it, he'll shoot, and use the rushing liquid to block the heroes from stopping his escape.
Blade servers inserted vertically (like a server rack lying on its back)?
Have gnu, will travel.
Fluorocarbons don't tend to be particularly flammable themselves; but the halogenated compounds not specifically designed for firefighting do sometimes have some...zesty...thermal decay products. They may or may not be self-sustaining reactions, and may even pull enough energy out of a would-be fire to help suppress it; but there are very few biological processes that are improved by adding improv halogen compounds...
Since a wide variety of materials trade under 'Novec' with various model numbers, it's hard know which MSDS to link to; but hydrogen fluoride/hydrofluoric acid seem to be common to almost all of them, if thermally displeased, with some oddities like Perfluoroisobutylene and Perfluorinated acid fluorides for flavor, in certain compositions.
All claim to be pretty well behaved at lower temperatures; but at 3-400 degrees (Celsius) I'm staying the hell away.
Allied Control has been using Novec 649 which has the same MSDS as 3M Novec 1230 Fire Protection Fluid.