6 ms·

I'm curious why liquid cooling for computers still uses compression fittings and other odd methods. Compression fittings are widely out of favor due to their t

I'm curious why liquid cooling for computers still uses compression fittings and other odd methods. Compression fittings are widely out of favor due to their tendency to leak, and nowadays everything is copper, pex, or metal+flared fittings. I wonder if there's a PC running PEX-A for tubing. Further thoughts: Brake lines use flared fittings, with either metal tubing or plastic tubing with metal ends. Uses a special bolt that allows liquid through the pipe to enter the caliper, and is removable. I would imagine something like that could work to make the lines to the individual servers serviceable without relying on flaky plastic "quick connects".

lazide 5y ago
Compression fittings are generally more convenient and cost effective than Pex or copper in small volumes and with little experience. The only downside as you note is leaks if someone doesn’t do them right (or as time passes), but that tends to be more of problem at higher household service line pressures (60+ psi) If it is a low pressure recirculation system, you can get by with almost no tools and most people if they read instructions at all probably won’t mess it up bad enough to have a leak. The brake line connectors could be interesting, but aren’t likely to work well stock - brakes are very low flow, high pressure as they are ‘dead ended’ hydraulic systems used to transfer force, not loops for cooling purposes. Also those bolts can work loose, and then you have leaks. Brakes require experienced technicians or people die, so folks working on brakes tend to be the more qualified and experienced mechanics, and they make sure to torque to spec, clean surfaces, do proper prep, etc. which is not what you want to have to worry about from an idiot proofing perspective.
- heelix 5y ago
  Man, if only copper was easy. One of the gotchas is most connectors for CPU, graphics cards, and chipsets tend to use the G1/4" ends up having metric on the other side. 12mm or 13mm. Most copper pipe is .5", which works out to about 12.7mm. You have to be really picky with couplers if you want to use copper. PTEG/Acrylic is less great for things that would be banged around and a pain, compared to if you know how to actually do copper.
  - namibj 5y ago
    Or you just use actual metric copper pipes in 12mm....
    - lazide 5y ago
      Good luck finding those easily around here!
      - namibj 5y ago
        Yeah, it's one of the more practically relevant downsides of not really switching to metric. It could start with mandating metric-based norms for building parts in new designs for federally-funded construction, as well as mandating in consumer protection regulation that the metric measurements have to be no less prominent than non-metric units (well, technically that'd be about SI units). At some point potentially requiring operations with large-enough warehouses to offer the metric-norm equivalents for parts according to non-metric legacy norms, if they reach some threshold with inventory turnover on those parts where it'd not be a big burden to also offer those metric equivalents. But yeah, I know the feeling of foreign norm components being hard to get, from when I tried to get the screws used for consumer-grade camera tripod mounts. They are iirc 1/4" machine screws. Roughly like M6, but far from compatible.
        lazide 5y ago
        Yup, or even equipment with mixed standards that are kinda close so you have to start pulling out multiple thread gauges just to figure out WHY you're particularly screwed, and for how long will you remain so. Plumbing is rife with it near as I can tell. Semi-random differences in thread pitches, metric vs standard, etc. everywhere.
intpx 5y ago
RGB-life liquidcooling != Data Center liquid cooling They have precision dry break quick connects. They use crazy jacketed hoses with PTFE liners and copolymer sheating, sometimes with reinforcment layers. The coolant is pumping through at an operating pressure of 10bar @ 200C. These applications exceed the limits of potable water and hydronic heating systems
- deleted 5y ago
  [deleted]
- namibj 5y ago
  For what reason would a datacenter operate 200C coolant?
  - bob1029 5y ago
    The only reasonable thing I can come up with is we got an extra 0 here. 20C/68F sounds like a more practical temperature for keeping the computers alive.
    - namibj 5y ago
      It's actually quite cold, if you're thinking of water blocks on the chips. It does fit if you're thinking of air-to-water heat exchangers to cool the hot exhaust of a google rack before recirculating. Something closer to 30C or even 40-45C (the latter if you're in a hot and humid location like Florida and want to get by without refrigeration technology and just increasing the flow rate/heat exchangers) is more realistic for datacenter-scale component-level water cooling. Yeah, a high-power-density Nvidia chip may need colder water in the 20-30C range, but CPUs and such aren't efficient at the clocks that cause power densities where you need <<40C water. My 5950X is running at ~30C (return from the radiator) water and 4.5 GHz (maybe even a bit more? I don't recall, the heat wave around here is over) on a torture test with Prime95 where it produces almost double the nominal TDP (thermally limited, due to a few hot-running cores and around 80-85C average core temperature on the others). The base clock is at just 3.4 GHz. I see phase-change cooling with nucleate boiling as well as very tightly integrated (liquid) water channels in the future, with the latter thinning out the die to weld or solder a better thermal conductor closer to the actual transistor junctions, with minimal distance to the coolant.
namibj 5y ago
I'm about to get me proper industrial quick disconnects (the hard part is the disconnecting, not the connecting, as otherwise a simple valve on each end and a screwed fitting would suffice) for my workstation, so that I can put a large radiator outside of my room and still have an easy-to-carry system when I need to be somewhere else and have a proper computer. It's just no longer silent at that point. These quick disconnects are polymer, but that's in large part due to corrosion resistance. They are also rated to ~8 Bar and also vacuum, if one would use the latter. Also, for flexible tubing, compression fittings don't seem like such a bad idea. Yes, don't use them for rigid pipes (PEX counts there, for connecting purposes), but the only thing better than squishing the hose into a seal-barb seems to be welding the hose to the connector...

lazide 5y ago

Compression fittings are generally more convenient and cost effective than Pex or copper in small volumes and with little experience. The only downside as you note is leaks if someone doesn’t do them right (or as time passes), but that tends to be more of problem at higher household service line pressures (60+ psi) If it is a low pressure recirculation system, you can get by with almost no tools and most people if they read instructions at all probably won’t mess it up bad enough to have a leak. The brake line connectors could be interesting, but aren’t likely to work well stock - brakes are very low flow, high pressure as they are ‘dead ended’ hydraulic systems used to transfer force, not loops for cooling purposes. Also those bolts can work loose, and then you have leaks. Brakes require experienced technicians or people die, so folks working on brakes tend to be the more qualified and experienced mechanics, and they make sure to torque to spec, clean surfaces, do proper prep, etc. which is not what you want to have to worry about from an idiot proofing perspective.

heelix 5y ago
Man, if only copper was easy. One of the gotchas is most connectors for CPU, graphics cards, and chipsets tend to use the G1/4" ends up having metric on the other side. 12mm or 13mm. Most copper pipe is .5", which works out to about 12.7mm. You have to be really picky with couplers if you want to use copper. PTEG/Acrylic is less great for things that would be banged around and a pain, compared to if you know how to actually do copper.
- namibj 5y ago
  Or you just use actual metric copper pipes in 12mm....
  - lazide 5y ago
    Good luck finding those easily around here!
    - namibj 5y ago
      Yeah, it's one of the more practically relevant downsides of not really switching to metric. It could start with mandating metric-based norms for building parts in new designs for federally-funded construction, as well as mandating in consumer protection regulation that the metric measurements have to be no less prominent than non-metric units (well, technically that'd be about SI units). At some point potentially requiring operations with large-enough warehouses to offer the metric-norm equivalents for parts according to non-metric legacy norms, if they reach some threshold with inventory turnover on those parts where it'd not be a big burden to also offer those metric equivalents. But yeah, I know the feeling of foreign norm components being hard to get, from when I tried to get the screws used for consumer-grade camera tripod mounts. They are iirc 1/4" machine screws. Roughly like M6, but far from compatible.
      - lazide 5y ago
        Yup, or even equipment with mixed standards that are kinda close so you have to start pulling out multiple thread gauges just to figure out WHY you're particularly screwed, and for how long will you remain so. Plumbing is rife with it near as I can tell. Semi-random differences in thread pitches, metric vs standard, etc. everywhere.

intpx 5y ago

RGB-life liquidcooling != Data Center liquid cooling They have precision dry break quick connects. They use crazy jacketed hoses with PTFE liners and copolymer sheating, sometimes with reinforcment layers. The coolant is pumping through at an operating pressure of 10bar @ 200C. These applications exceed the limits of potable water and hydronic heating systems

deleted 5y ago
[deleted]
namibj 5y ago
For what reason would a datacenter operate 200C coolant?
- bob1029 5y ago
  The only reasonable thing I can come up with is we got an extra 0 here. 20C/68F sounds like a more practical temperature for keeping the computers alive.
  - namibj 5y ago
    It's actually quite cold, if you're thinking of water blocks on the chips. It does fit if you're thinking of air-to-water heat exchangers to cool the hot exhaust of a google rack before recirculating. Something closer to 30C or even 40-45C (the latter if you're in a hot and humid location like Florida and want to get by without refrigeration technology and just increasing the flow rate/heat exchangers) is more realistic for datacenter-scale component-level water cooling. Yeah, a high-power-density Nvidia chip may need colder water in the 20-30C range, but CPUs and such aren't efficient at the clocks that cause power densities where you need <<40C water. My 5950X is running at ~30C (return from the radiator) water and 4.5 GHz (maybe even a bit more? I don't recall, the heat wave around here is over) on a torture test with Prime95 where it produces almost double the nominal TDP (thermally limited, due to a few hot-running cores and around 80-85C average core temperature on the others). The base clock is at just 3.4 GHz. I see phase-change cooling with nucleate boiling as well as very tightly integrated (liquid) water channels in the future, with the latter thinning out the die to weld or solder a better thermal conductor closer to the actual transistor junctions, with minimal distance to the coolant.

namibj 5y ago

I'm about to get me proper industrial quick disconnects (the hard part is the disconnecting, not the connecting, as otherwise a simple valve on each end and a screwed fitting would suffice) for my workstation, so that I can put a large radiator outside of my room and still have an easy-to-carry system when I need to be somewhere else and have a proper computer. It's just no longer silent at that point. These quick disconnects are polymer, but that's in large part due to corrosion resistance. They are also rated to ~8 Bar and also vacuum, if one would use the latter. Also, for flexible tubing, compression fittings don't seem like such a bad idea. Yes, don't use them for rigid pipes (PEX counts there, for connecting purposes), but the only thing better than squishing the hose into a seal-barb seems to be welding the hose to the connector...