June 8, 2024:
I love camping. Including in the snow, winter. It can be deadly. I don't know what will ultimately kill me, but it could be a mistake in the wilderness leading to hypothermia. Camping is no joke. Experience teaches that the marketing gloss of the specialized equipment is oriented towards the oversocialized overcivilized 'decadent'; the equipment is designed for small forays, then escape back into the hamster pod life. The sophisticated equipment breaks down after short expeditions, even true expedition gear is only designed to last for the expedition/operation. Bushcraft is the response to these absurdities. Being able to live sustainably in the wilderness with robust tools like an axe, one can survive the inevitible breakdown of the fancy tent, the fancy bedding, and the fancy sleeping bag. None of these by the way can survive the only source of heat == survival in the winter, the bonfire. By the way, bushcrafters cutting by axe for survival in the winter will not destroy forests, indeed, this will prevent summer meltdowns by grooming, thinning, separating stands of trees. Not to speak of the holistic mass effect of improved spiritual grounding of bushcraft engaged people on the health and constructive power of the population as a whole.
Counterpoint to the bushcraft purity spiral, keeping the polarity in mind, not being luddite about the camping tech. Enjoying both, enjoying tech and also the bushcraft layer of functional redundancy...
Hot tents, great idea, old idea, with newer tech.
I love heating rocks in my Namajt 2 GT vestibule on gas stove. Always ventilated, often with the tent closed and the vestibule open, this is a great way to produce an ample and steady source of infra-red radiation in the tent, adding tremendous surplus to the body heat in there, especially if suffering a bit of hypothermia.
For some reason, considering the titanium telescoping chimney and collapsable titanium wood stoves thing, quite brilliant, I started thinking about designing the most minimal possible radiator system. Heating and circulating water through a tent. A leak would not be fun. Maybe plastic hose or something like that. Some kind of hose that can go up pretty high. I wonder if the whole thing could be powered out of a campfire. That is, harness the thermal energy for not only heating the water, but pumping, and enough electrical for control, although mechanical solid state control would be ideal for reliability.
This might be something a bushcrafter might even use, that is one who is not purist. Because you could make a lean too, insulate it, make a mattress out of pine needles, and then run the plastic tubing in for radiator heat, just dropping the node into the campfire, and the water runs, gets heated, and pumped.
That would be crazy technology. Crazy good plumbing.
How would you feed the water supply of this thing? By pouring snow into a wetsack like bag. This will get melted down into water and used ?
Or maybe you just keep a tank full, and that lasts a certain number of hours, there is only so much loss. Or you could put some kind of feeder line into deep snow, it melts and catches what's around it.
We could solve this in stages, so the first stage we assume we have power for pumping the water, and we have power for logic, so we just want to design something that can be dropped into a campfire, such that water is pumped through this to a temperature, then it is remixed as necessary before being pumped to the target dwelling 10-20 feet away. You've got to deal with heat loss en-route to target, could lose quite a bit, might want to insulate some of that pipe or maybe it don't matter that much.
The water is going through the target dwelling (I'm thinking a lean to, but we could think a nice techie tent too) and then back out to be run through the fire again before it has a chance to freeze up. Gotta check water temperature along the whole unit, keep flow etc.
The part of the hose that goes through the dwelling has material profile for strength to protect from sharp objects, but allows a lot of heat transfer. The part of the hose going through the fire must be hardest strongest metal and allow high heat transfer. The parts of the hose in transit between fire and dwelling must be heavily insulated preventing heat transfer, and also quite strong, but flexible, and light. The parts of the hose between transfer and fire central will be flexible metal for more heat resistance, but also heavily insulated already.
There will be a unit leading out of the fire which will be able to add in cold water to the mix before the water heads to the dwelling, so that a consistently highest possible temperature is achieved in output water without exceeding limitations of the material or safety considerations.
Pump speeds can also be configured to help regulate this stuff.
When lower output is required, the part in the fire may not need any flow at all, in which case the water in it would likely vaporize, pressurize, etc, so there will need to be blowoff valves etc.
That part will likely require replacement and/or be quite dense and heavy.
Now, I set power generation (electrical for logic and the pumps) aside, as I couldn't think of the answer, but of course it came to me and is quite obviously steam turbine generated power, as we have all the means already at hand, with the water and the fire-pit capable of boiling more than enough for our needs. This reminds me of these camping stream/creek hydro-electric generators, and I'm wondering whether some web-research would turn up some new ones working on campfire or stove created energy from boiled water. I'm sure there are people working on this.
the issue i'm thinking of now is whether we can use that power directly or can we only operate off of the battery, which we charge? this is important because batteries are fickle and sensitive things, whereas we want to operate with high reliability in harsh conditions. so it would be better to work with overscale + low-tolerance + hardened-as-much-as-possible electronics, which can operate to large degree from power generated on the spot. In this way too, even if we need to rely on batteries, we can focus less on battery life long lasting and more on battery reliability. Because our batteries are only required to step in for the odd outage, power interruption. But as long as there is water supply, and as long as there is heat, just like an operating motor vehicle with a functioning alternator, it doesn't matter what the battery is doing, there is plenty of electrical power (depending on how fast the alternator is being spun by the motor). Point being, for things like pumping water, which is energy intensive, we don't need to rely on any battery at all; like the car that's on and revving the alternator good enough, we'll always have power, because there is constant plentiful water supply, and an overcapacity of heat. If the thing requires more power for the pumps, it can let in more water to be heated into steam, run it through that steam generating channel, out the stack, whirrrr, and power, not to the battery, but just circulating through that system, plenty for the pumps, not to speak of the logical circuits.
Outline of the device:
(1) We have given lots of attention to the part that's in the fire. (this could also be placed over a propane tank trivially, but we are considering the more interesting and difficult case.). This section has no in the firepit core, though at the ends there may be some blowoff valves. The core of this is hard metal, maybe with some ceramic parts.
(2) The main control unit, containing pumps, logics, and control section is some 10 feet off the fire, say right outside the lean-to, then the lean-to is 12 feet from the fire say. Pretty typical bushcraft setup, the fire a bit further away, as not necessary to be so close.
(3) The water input is part of the main control unit. Or rather something that connects to it. This may be like a bag of snow, I'll have to think about it, maybe a bag of water that it can just maintain at a thermostatic point.
Hoses note: The hoses out of the core of (1) are highly heat resistant flexible metal hose, then another gradient a bit further, then just robust travel hose with insulation, then the
(4) dwelling unit, thinking just clear plastic hose but haven't thought about it much.
It's interesting to consider startup in temperatures say -10 F or -25 C. Scenario: It's -10 F. Evening is coming on, lots of snow on the ground, some feet, plenty of pine to burn, exactly the kind of stand that would go off like a bomb in the summer, but now is a good time to thin and groom the woods, so we can axe away. (These are not BLM rules, but they should be, in winter, to prevent summer bombs, you need bushcrafters living wild and grooming that shit down thin) So, you got the lean-to constructed and a bonfire going in a pit. We'll assume the lines are not filled with water, frozen or liquid. So we presume some purging method, perhaps with pumped air. I would like to think about jump-starting in scenarios with dead battery, but for now assume a decent battery enough for logic startup, and perhaps you'd have to feed it liquid water initially, but basically, you place the core element in the middle of the hottest part of the fire, and pour maybe a liter of water into the main unit, or perhaps into a special feeder closer to the core, enough to get some water into a position in the core hot enough to turn it to steam, this is controlled by actuators at the periphery of the fire core device, so perhaps it would be better to separate these into two components. There is the highly robust core component for heat capture, but the water control / valve control is at the edge of the fire, where the heat is managable. Also of course the system has to manage the heat in all of its elements to prevent seizure. Of course it has plenty hot water for this. Once the system is energized directly by steam power, it no longer has to rely on the batteries at all, except in power dips, and those should not happen, if the fire is big enough and the core is placed in a hot enough section of it.
So now it can pump more water into the fire, not just for steam, but now also for hot water, which it will use to mantain the temperature of its water reservoir, and also if necessary to make more water by melting snow. Snow is bulky though, so it may be better to work with water bags. Bags of liquid water that can be recirculated to maintain temperature, even before it's heated, just because it's outside at -25F. The system as a whole is closed-circuit as far as the water heat transfer is concerned. No doubt there will be losses, but not all that much. So not much water is required over a 12 hour run. You will spend more time re-filling the fire, and we will need to consider all of the various graceful shutdown modes the thing goes through, ultimately having to consider things like freezing water lines. This will be the most challenging aspect. Considering the core unit, going from such high temperatures all the way down to sub-zero, and handle all of this gracefully without exploding under phase changes of the materials.