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Comment by Mistletoe | Hacker News Reader

There is a lot of silly stuff in Dune, you just have to roll with it. A still suit would kill you from heat because your sweat is never evaporating.

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You'd suffocate inside Holtzman shield too as air molecules whizz at ~500m/s.

If the environment temperature is lower than body temperature and the suit has air cooling with fins or something, it could work.

That seems unlikely to be the case on Arrakis.

What is precluding it from having a small heat exchanger in there? Similar to a mini-split but integrated?

I think it would be pretty hard to power it.

https://www.quora.com/How-many-BTUs-would-you-need-to-cool-j...

>So we have to pump 150 + 22 = 172 watts of heat up a thermal gradient of 10C — more if it's hotter. If I assume a slightly pessimistic factor of 2 for the heat pump, that's an electrical input of about 85 watts to the heat pump, plus some to run fans and coolant pumps in the suit — my guess is that you need a minimum of around 250 watts to power the suit.

>Sounds distinctly unpleasant to wear.

>Edit:: and if the cooling stops, get out of the suit quickly, before you roast.

I dunno, they have interstellar spaceships. Sun on earth is 1kW/m^2 at equator, not sure what it would be on Dune, but doesn't seem that unreasonable that they could have it powered by some advanced solar cells integrated in the suit.

there is a lot of silly stuff in Dune, but my understanding is that the still suit recycles the body's water. It's not just that you pee in a tube, it absorbs the sweat and recycles that too

Sweating works by phase change. Water going from liquid to gas takes lot of energy. Thus removing it from body. On other hand if you then collect that steam and make it liquid again well you have to dump that energy back to the body. Or conduct or radiate it away... But those are inefficient thus we sweat.

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