5 ms·

> Modern CPU heat pipes are typically made of copper and use water as the working fluid. So there's water inside my laptop?

supertrope 2y ago
Water is the original coolant. Abundant, decent performance, cheap, non-toxic.
- dogma1138 2y ago
  Not only decent performance but the highest head capacity of all liquids, and it’s boiling point can be easily adjusted by lowering pressure if required.
  - bumby 2y ago
    Ammonia tends to outperform water, but it's toxic. I believe it was used in some of the first refrigeration applications (and I think Einstein had a patent related to one).
    - anfractuosity 2y ago
      I came across potassium nitrate + water being used for making things cold - https://cordis.europa.eu/article/id/36036-making-things-cold-a-history-of-science-technology-and-culture https://cordis.europa.eu/article/id/36036-making-things-cold... . Wonder if that could be used too?
    - jaclaz 2y ago
      Absorption refrigerator: https://en.wikipedia.org/wiki/Absorption_refrigerator https://en.wikipedia.org/wiki/Absorption_refrigerator Einstein refrigerator: https://en.wikipedia.org/wiki/Einstein_refrigerator https://en.wikipedia.org/wiki/Einstein_refrigerator The principle is still used in some refrigerating devices (typically hotel mini fridges and similar small units for RV's) as there is no need of a compressor (i.e. the device is completely silent) and also in some HVAC machines.
    - dogma1138 2y ago
      We aren’t talking about regurgitation but rather about heat transfer. Ammonia has lower heat capacity than water, and it’s nasty.
      - bumby 2y ago
        >Ammonia has lower heat capacity You’re probably confusing gaseous ammonia, but the GGP said “of all liquids.” Liquid ammonia has a higher heat capacity than liquid water. Refrigeration is just an engineering application of the heat capacity of a working fluid (and I’ll let you guys why some of the earliest heat pumps used ammonia) >it’s nasty I clearly stated toxicity as an obvious downside.
- lesuorac 2y ago
  But also corrosive.
  - taskforcegemini 2y ago
    unless distilled
    - elcritch 2y ago
      Ah distilled water is terrible for metal pipes. It’ll leach out metal ions from the pipes.
tantalor 2y ago
And steam!
- ikekkdcjkfke 2y ago
  I want a steam generator on my cpu now, whistle and all
smolder 2y ago
If it has heat pipes/vapor chambers then yeah, it's like the chips are heating elements for a little low temperature, low pressure boiler.
Sakos 2y ago
Interestingly, heat pipes in a computer can corrode and leak the coolant (largely escapes as water vapor). Once it's gone, the heat pipes are basically junk. I've seen this a few times, wondering why the thermal performance was so abysmal (think 90-100 degrees celsius with low loads). It was only after completely replacing the heat sink or whatever assembly contains it that temperatures would be normal again.
- Brian_K_White 2y ago
  Corrosion requires a constant source of fresh oxidant. The water trapped inside a heat pipe cannot corrode anything. The tiny amount of free oxygen that was ever trapped inside gets consumed essentially immediatly and amounts to a relative handful of atoms on the inner surface. If a heat pipe ever corroded and leaked, it was manufactured with a leak to begin with, or was corroded from the outside.
  - Sakos 2y ago
    I never said the coolant corroded the heat pipe.
    - ungamedplayer 2y ago
      Your CPU pins rusting is a bigger concern then.
      - Sakos 2y ago
        I never said it was a risk or concern or anything else in that direction. I was just pointing it out because I thought it was interesting. There was a time I didn't realize there was coolant in these heat pipes that could escape. Until encountering one where it had dissipated and, after some consternation and googling, realizing what must have happened to cause such terrible thermal cooling performance. Even if it does happen, heat pipes are among the cheapest components to replace (also the easiest). Does everybody just want to argue over nothing now?
mystified5016 2y ago
Sometimes they use ammonia instead!

supertrope 2y ago

Water is the original coolant. Abundant, decent performance, cheap, non-toxic.

dogma1138 2y ago
Not only decent performance but the highest head capacity of all liquids, and it’s boiling point can be easily adjusted by lowering pressure if required.
- bumby 2y ago
  Ammonia tends to outperform water, but it's toxic. I believe it was used in some of the first refrigeration applications (and I think Einstein had a patent related to one).
  - anfractuosity 2y ago
    I came across potassium nitrate + water being used for making things cold - https://cordis.europa.eu/article/id/36036-making-things-cold-a-history-of-science-technology-and-culture https://cordis.europa.eu/article/id/36036-making-things-cold... . Wonder if that could be used too?
  - jaclaz 2y ago
    Absorption refrigerator: https://en.wikipedia.org/wiki/Absorption_refrigerator https://en.wikipedia.org/wiki/Absorption_refrigerator Einstein refrigerator: https://en.wikipedia.org/wiki/Einstein_refrigerator https://en.wikipedia.org/wiki/Einstein_refrigerator The principle is still used in some refrigerating devices (typically hotel mini fridges and similar small units for RV's) as there is no need of a compressor (i.e. the device is completely silent) and also in some HVAC machines.
  - dogma1138 2y ago
    We aren’t talking about regurgitation but rather about heat transfer. Ammonia has lower heat capacity than water, and it’s nasty.
    - bumby 2y ago
      >Ammonia has lower heat capacity You’re probably confusing gaseous ammonia, but the GGP said “of all liquids.” Liquid ammonia has a higher heat capacity than liquid water. Refrigeration is just an engineering application of the heat capacity of a working fluid (and I’ll let you guys why some of the earliest heat pumps used ammonia) >it’s nasty I clearly stated toxicity as an obvious downside.
lesuorac 2y ago
But also corrosive.
- taskforcegemini 2y ago
  unless distilled
  - elcritch 2y ago
    Ah distilled water is terrible for metal pipes. It’ll leach out metal ions from the pipes.

tantalor 2y ago

And steam!

ikekkdcjkfke 2y ago
I want a steam generator on my cpu now, whistle and all

smolder 2y ago

If it has heat pipes/vapor chambers then yeah, it's like the chips are heating elements for a little low temperature, low pressure boiler.

Sakos 2y ago

Interestingly, heat pipes in a computer can corrode and leak the coolant (largely escapes as water vapor). Once it's gone, the heat pipes are basically junk. I've seen this a few times, wondering why the thermal performance was so abysmal (think 90-100 degrees celsius with low loads). It was only after completely replacing the heat sink or whatever assembly contains it that temperatures would be normal again.

Brian_K_White 2y ago
Corrosion requires a constant source of fresh oxidant. The water trapped inside a heat pipe cannot corrode anything. The tiny amount of free oxygen that was ever trapped inside gets consumed essentially immediatly and amounts to a relative handful of atoms on the inner surface. If a heat pipe ever corroded and leaked, it was manufactured with a leak to begin with, or was corroded from the outside.
- Sakos 2y ago
  I never said the coolant corroded the heat pipe.
  - ungamedplayer 2y ago
    Your CPU pins rusting is a bigger concern then.
    - Sakos 2y ago
      I never said it was a risk or concern or anything else in that direction. I was just pointing it out because I thought it was interesting. There was a time I didn't realize there was coolant in these heat pipes that could escape. Until encountering one where it had dissipated and, after some consternation and googling, realizing what must have happened to cause such terrible thermal cooling performance. Even if it does happen, heat pipes are among the cheapest components to replace (also the easiest). Does everybody just want to argue over nothing now?

mystified5016 2y ago

Sometimes they use ammonia instead!