I have a hard time believing that I lose more moisture from breathing than sweating, at least since I started taking this @#$% medication that makes me sweat buckets under the influence of any heat or exertion whatsoever. I’ve had to raise my water intake by half a gallon a day to compensate for the increase. (Anybody know of any anti-perspiration medications or creams or whatever out there? I’ve actually tried using conventional underarm anti-perspirant gel on my forehead and face, but that doesn’t work. Maybe I should start a thread to ask about this…)
Anyway, I would be interested to find out how much water I lose from breathing, so I can see how that compares with the water I lose sweating, and also how it compares to what a normal person loses from sweating (which I assume is less than what I do).
This link suggests that I was wrong about water lost through respiration vs. sweating. However, it does seem that water lost during normal defecation is fairly minimal, so I wouldn’t feel bad about skipping the fecal-processing issues of designing a working stillsuit.
That’s the point. You heat the water up and need to shed that heat, but what chemical reaction allows you to do that? It has to be a reaction that can be maintained using something that is commonly available. In the desert, that’s likely to be sun, sand, salts from your drippings and camel dung.
@chorpler. Start a thread on your question. As a fellow sweaty bastard I’d like to see if anything relevant to me comes up .
I don’t care what youse all say – a stillsuit sounds too much like wrapping yourself up in a plastic bag out in the desert, which sounds like a recipe for heatstroke.
I think an essential element of designing a working stillsuit is to allow open areas in which the skin can breath. It seems to me that not all the sweat need be reclaimed – maybe only half of it.
The function of the large intestine is to remove water from the stool, anyway… why not let it do the job? It’s pretty efficient as long as one is healthy. I know I’ve taken some poops I would have qualified as coprolithic…
I imagine Fremen would have adapted to maximize this efficiency.
(And I also imagine they would consider diarrhea to be the most dreadful of all afflictions… :eek: )
As for the rest of the suit, I’ve been with bordelond all along… it makes no sense to try and duplicate the fictional suit, but to establish some performance specs you know you can meet, and design to those.
Recovery of water from respiration and urine are probably the two easiest things. Sweat would be easy if there were an efficient means to collect it, but that would take some ingenious fabric design…
Cooling is indeed a problem. You need some sort of heat pump to perform condensation… either that, or use a reverse osmosis type filter.
And like I said, it’s not going to recover 100%, but even 50% would reduce the water you need to carry by a significant amount.
The fecal-processing burden on the suit would also be minimal. When the human body is running on the dehydrated side, the rate at which you…expunge?..solid waste drops dramatically.
As examples, I have a couple of friends who desribed in great detail how their poop-cycles changed while they were going through desert warfare training in the military. I’m sure that there are dopers around that could corroborate. They said that after the first big dump or two, they dropped down to about once every two weeks. Also, the consistency changed from the healthy squishyness that we are all accustomed to, to more of a pebbly/caramel like consistency. To quote my friend “I shat taffy kibble”.
An episode of Survivor last season had one competitor remark that he only pooped once during the entire 3 week run he was on.
So I would bet that the “thigh pad processors” are really not critical to the suit’s function and are more useful for storage and cleanliness than water reclamation.
I believe NASA would be very interested in such a system. AFAIK they haven’t be able to properly process feces into water without bulky equipment (I believe they burn it for fuel and extract moisture).
“stillsuites” would be best utilized in space, not in a desert. Heat transfer can be controlled (space is cold but isn’t a very good for heat transfer). I would imagine such a system is possible if the suit covered the entire body and absorbed all moisture to be processed. The suit could also keep the lost salt inside the water to be ingested again (salt loss would also be an issue).
It probably wouldn’t taste “good” and the suit would still have to shed some material that cannot be processed (feces and solid liquid waste) but probably would work to keep whoever alive much longer than without.
Also, if you use the motion of the body, wouldn’t the extra work load on the person cause more water to be shed, thus requiring more work to process the water? I think solar power would be a better subsitute.
Collecting the sweat can be made loads easier by not attemptig to collect all of it – just some of it.
Gravity can do some of the work – perhaps there can be material at the forehead, neck, wrists, waist, lower thighs, and ankles that collects sweat. Think sweatband material.
It seems to me that everybody is making some assumptions about a ‘stillsuit’ like technology that might not be necessary. I get the impression that alot of people think that a ‘stillsuit’ is supposed to be form fitting, and that it’s development depends on advances in materials science alone. I think a looser fitting, multi-layered garment utilizing bio-engineered symbiotic bacterias as well as smart materials and nanotechnology could make a water reclaimation and waste processing suit with a high degree of efficiency. It might even be solar powered to some extent and provide the wearer with a food source through artificial photosynthesis, a compact little ecosystem that you wear and are a part of.
There are no unnecessary assumptions. The OP was pretty clear.
That’s “Dune-style” and “today’s technology” – not an exact functional replica of a Fremen stillsuit using hypothetical technology.
Yes, it could be Dune style. No, it wouldn’t work as well as in Frank Herbert’s vision. And yes, it would be expensive, and anywhere from somewhat difficult to extremely difficult depending on which wastewater products it needed to recycle.
I can’t recall the name, but cloaks are worn over the stillsuits. They allow heat transfer in one direction only. During the day, they’re used to dissipated body heat. At night, they’re used to keep warm. The cloaks can also be fashioned into tents in case of sand storm.
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