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Comment by bdjsiqoocwk | Hacker News Reader

> Modern CPU heat pipes are typically made of copper and use water as the working fluid.

So there's water inside my laptop?

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.

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.

I never said the coolant corroded the heat pipe.

Your CPU pins rusting is a bigger concern then.

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?

Maybe I'll rephrase.

Is the CPU pins rusting a bigger concern, compared to if the heap pipe busts ? Thats not an argument, it is a question.

I wonder if the obsolescence of such heat pipes corrode just outside of the warranty period...

Honestly, I think that's extremely unlikely. In the time I worked as a PC tech I think I saw this only twice and they were very old devices (like 8-10 years old).

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

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.

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).

Absorption refrigerator: https://en.wikipedia.org/wiki/Absorption_refrigerator

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.

I came across potassium nitrate + water being used for making things cold - https://cordis.europa.eu/article/id/36036-making-things-cold... . Wonder if that could be used too?

We aren’t talking about regurgitation but rather about heat transfer.

Ammonia has lower heat capacity than water, and it’s nasty.

>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.

But also corrosive.

unless distilled

Ah distilled water is terrible for metal pipes. It’ll leach out metal ions from the pipes.

Sometimes they use ammonia instead!

And steam!

I want a steam generator on my cpu now, whistle and all

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.

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