Solar still makes fresh water from salt water. Used in Liferafts for survival at sea and emergency situations. Sun heats up the salt water which than evaporates and condensates. It is part of emergency equipment on many ocean going sailboats and vessels.
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I recently read a book by a guy who stayed alive in a life raft for 76 days drifting across the Atlantic. He had two of these as his main source of fresh water.
Actually I saw the documentary, he said they did not come with a manual thus he did not know how to use them.
@@Couplescience Wow, I can't imagine how scary that must have been.
@@DrAhmadNabeel i think i found a flaw in the product's manufacturing process
Why do the maker of water makers do not use this technology - no wasted filters.
@@user9b2 Because you would use way more energy to transport the water and distilled water is more readily infected with bacteria due to less competitive inhibition. Also filters last a long time as they are one of the final steps in treatment.
Since I taught this in the military I can assure you the instructions say to have it set up before sunrise and DON'T play with it until after sunset. If you play around with it the action slows down the production. Just Leave It T.F. Alone until after sunset. Great demonstration !!!!!
how do you clean it... itll turn into an algea bucket... i feel like thats left out of the video for a reason...
@@jacobhoffman2553yea dude, its for a life raft, not for permanent use
@@jacobhoffman2553the collection point could but the algae won’t be in the distillation, if the interior walls got grimy I suppose it would be good if you could leave exposed to direct air/sun for a bit
@@jacobhoffman2553 there is a reason why some people should stay in their NY-NY apartment... This is evaporated water within 6 to 8hrs bottom sediment is salt top sediment is dead water, empty from any life, no mineral Bacteria grow/feed on what?
You taught this in the military, ok, but this ain't Nam - it's the Bahamas
That is a Fitzgerald still. I was fortunate enough to be helping Dr Fitzgerald with another project in the last '60's when he was developing this still design at RAE Farnborough. The principle feature is that conical, pointed top that allows condensed water to flow down the sides for collection, rather than drip from the top surface (of a ball) back to the black salt water collector. The fact that these are still being used points to the genius of the original specs and design. It was taken up by NATO for military survival and then by Aquamate for civilian use. Makes up to 2 litres per day in good sun.
Odd that I can't find a reference to any Dr. Fitzgearld (well, *you're* Dr. Fitzgerald) and any type of solar still... nothing for a Fitzgerald Still either. I can't find anything with the RAE and the name Fitzgerald. Help me out.
@@brianbassett4379 No I am just a retired Ex RAF pilot. I was seconded to Farnborough to specifically help out with some trials with the early Martin Baker ejection seats. Jim Fitgerald was pursuing various experiments to determine the amount of spinal compression that occurred with passive seating and shoulder strap arrangements on these seats. But that is perhaps not specifically interesting. The point was I was / am tall, with a long back and I was available between courses. The military is good at finding pegs for shaped holes. Anyway the point is, my experimental usefulness was usually over by about 10:00 as all my back compression was expended and only a night horizontal could get that back (pun intended). The still was one of the side projects that Jim had running and helped with in the PM. Somewhere I have pictures on me on the flat roof of the main building tending a prototype that looks exactly like the one in the video above. Right down to the black felt base and collection baggie. I don't recall the filler being the same, but it is a long time ago. However I was party to many rather interesting discussions about the utility of the conical top and the side ring collection etc. The prototypes were based, as far as I could tell, on simple children's inflatable rings with the top portion of plastic, cut and glued to form the cone. I did come across a unit in a sea survival course at RAF Mountbatten and it was demonstrated as in use in some large aircraft survival kits. AFAIK it was this one : www.echomax.co.uk/solar-stills. What became of Jim, I have no idea. He was in mid 40's (guess) when I met him, so as I was 18/19 then and am 73 now - you do the math. Hope this helps.
@@terciops awesome thanks for telling that!
its a source of nanoplastics, it can be built wih thin glass and wood,plant fiber or ceramic
@@crapisnice😂 Sure, that sounds incredibly easy to pack up as an emergency lifesaving device. 🙄 Nothing like having to worry about your life-saving emergency water source's wood/glass/ceramic pieces accidentally getting broken while you're waiting for help to arrive... The one in this video is obviously designed to be used in case of emergency, not as a replacement for a regular fresh water source. It makes sense for this to be made out of thin inflatable polymer in order for it to be stowed away somewhere (anywhere) until needed.
These things are incredibly expensive considering the manufacturing is not much different than making an inflatable beach toy.
The irony is that in capitalism, no lives matter
Spoken like a person who has never had to rely on their equipment for survival.
Every liferaft should have that as the top of the roof.
And a rainwater collector.
I learned this in method as a science project in middle school. We put dye in water and used a burner to imitate evaporation and then put saran wrap on a slant above it to catch the evaporating water. It collected on the top and when the droplets got big enough they rolled down into a separate dish as clean fresh water. Im currently 31 and that's the main survival tactic that has stuck with me my entire life lol.
I saw the emergency blanket can be used to make such a still.
“It’s basically almost nothing, but it’s something.” 👍👍👍👍😀
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well yes , but actually No
I’m pretty sure you want it in the water to keep help condense the evaporated water inside. Otherwise it will reach an equilibrium state where the rate of condensation is cancelled by the rate of re-evaporation.
I didn't know they worked this well. Absolutely something to put in a grab bag.
This well? 🤣
@@Ulexcool I didn't think they worked at all to be honest, but you actually get some water.
These have been around for about 35 years . Good product .
35 years +. I was taught to use these 1977 Merchant navy lifeboat instructions
You should taste the water and let us know how it tastes. Thanks for the video!
What's crazy is at work we open a lot of Life rafts that are put on all kinds of yachts not one of them has ever had a solar still in the light raft with the rest of the supplies you have a life raft whenever you get it packed make sure you add a solar still to it otherwise you won't have one
You know, I always wondered about this as a kid living in the southeastern United States during the summer. Any piece of plastic would have water on the back of it tarps buckets bottles… It always made me think if you were to end up deserted or in a position to have to get fresh water, it would be a good idea to put your water source in a little tent made of plastic, and it would evaporate and condense. It might still stink like the source, but I never was quite sure if that was enough for it to evaporate and condense that way to drink. I swear I thought of this by myself. It’s so funny that it turns out that’s exactly what you do. I wonder why it is people think commonly like this with materials that we’ve not had but just for a few generations
The way you want that little tent setup for survival is in a hole. Put a collection bottle or clean bowl at the bottom of a small hole you can cover with plastic. Make sure the edges of the hole reach however large your piece of plastic is. Place a single rock or pebble in the center, over the bottle or bowl, and the water will drip all day down into it. After sunset, go retrieve your water.
Wow. This is only the second time I have seen one of these. The first time I saw one was on a science show (Science International, a.k.a. What Will They Think of Next?) back in the late 1970s when I was still a kid. At that time, it was something new that was still under development. I guess it must have worked because the one in this video looks almost identical to the one I saw on that show over four decades ago.
The Solar still is old. The Navy had it on life rafts before 1958, that I know of. I was SUB Duty.
When used properly the motion of the waves accelerates the process and the catch bag hanging below facilitates fluid transfer better. I'd bet the instructions say that very thing.
First time I’ve seen this, thanks Igor!
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I recently heard that if you’re using this to survive, you need to put a couple drops of sea water back in to replace minerals.
it's made to function when the dome has lots of slack and wrinkles in it. it will produce about 3x the water than if it is stretched tight. personal experience
So maybe it would benefit from some vertical ribs inside to encourage the water to flow down ....
You need to keep it in the water so that the cooler water helps the moisture to condense. You need to constantly remove moisture from the air in order for more moisture to take its place through evaporation. Condensation speeds up the EVAP rate, etc etc
That is totally wrong.
Clever bit of equipment. Thank you for showing us. Could be adapted for desert survival.
Yup all that water in the desert.....
@@TOMVUTHEPIMP Well, camel urine. Ahem.
If you put a small solar cell, and a pump you can pump the cold water over the top to get much more condensation
I designed one of these in 2002 as part of my undergrad engineering degree. It's damn near identical to this.
You weren't failed for copying a decades old design?
Yea seriously these have been around since AT LEAST the early 70s. I know because I had to use one a few times in survival training back then.
What a cool idea! Use it over any still body of water,such as the Boundary Waters ,up in Minnesota, or any lake where one camps and the water isn't moving....and I can see this on stilts for use in small streams and in quieter areas of rivers....I appreciate this idea! Thank you!
I wonder how long the plastic can last in the sunshine. I hope that's been taken care of. Nice design. Could we have something that covers more area and produces more water, other than a bigger still.
this should be a required part of every sea based survival kit.
I think I would prefer a rigid structure for more durability. This one becomes unusable as soon as it leaks air. So I would argue this style is too unreliable.
@@fgregerfeaxcwfeffecea commenter on here said that this is the light commercial model, and there is a sturdy model that's being used in life rafts.
Duct tape is your friend
I came up with an idea like that about thirty years ago. I was working a pay-check to pay-check job and did not have the money to develop it.
the old slow method for a life raft. Make a roll of the boat during the rain and collect water at the bottom of the sail - so you can stock up on water until the next rain
I need a couple dozen of these. I would like to take a bath everyday if I was lost at sea.
They sell them surplus.
Don't forget the ice maker
You uh. . .you can bathe in salt water. It won't hurt you. You just can't drink it. you don't been fresh water for a bath. Jesus christ. Go read a book.
I think it works better in the sea so the cooler ocean water helps collect the condensate.
It doesn't. The black bottom is black so it is heated more than the top. The top is where the water vapor condenses, not the sides or bottom. Being in the water defeats this. Its only designed to float because its for an emergency life raft where they would be no room in it for a still.
No. You want it as hot as possible in the chamber. The heat is what makes the water evaporate, which is the more necessary part. As long as the air is cooler than the inside, its going to condense. The faster it evaporates, the faster it can collect. You want it to be as hot as physically possible.
It’s also good for freshwater because a lot of the bacterial and what not contaminant gets left behind since it’s not carried on the water vapor inside the still
Simple idea, simple gadget, excellent outcome
Been wanting to know. Thanks for sharing Igor!
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I wish you had done a taste test. Would the water still taste salty? Would it taster weird, flat, or good? As is, it's an interesting but incomplete video.
I know the heat and evaporation of the salt water is what your looking for but I would think the fresh water collected around the bottom edges you would want some what cool (or at the sea surface temp) to keep it from evaporating back into the still.
What a clever idea. It's ideal since it doesn't take up much room in a grab bag and if you have to abandon ship you've got fresh water.
Thank you, this was very useful.
You need to add a vacuum hand pump to the unit to create a lower vapour pressure inside the unit, which will lower the temperature boiling point of the water and accelerate evaporation.
Not gonna work in a unit this small, dude. The water surface is too small and it wouldn't weight enough to prevent it from rising up and filling the thingy with water.
If you are using a handpump, better add a small RO filter and directly pump out drinking water.
It's inflatable. If you turned it into a vacuum it would collapse from the outside air pressure.
Still needs to be floating, so it can work on difference in temperature between the greenhouse top and the cooler water below. That's what makes the evaporating seawater condense and flow down the cone.
Когда я учился в мореходном колледже, то запомнил пропорцию - 1:43. Именно в такой пропорции нужно разбавлять воду, полученную дистилляцией с океанской солёной водой. чтобы получалась в итоге нужная, для питьевой воды, минерализация. Может, кому то пригодится.
it has a design flaw in that the steam is supposed to be cooled down by cold water.
Would have liked to see you drink the water and tell us how it was.
Fish etc are curious about these stills, and can easily puncture them. I read of this from a shipwrecked couple who had a liferaft.
Tried solar stills during military survival school training. If conditions are perfect you have a chance of getting enough water to stay alive. They are not something to be counted on as a practical water source.
It works better if you let it in the water, because the cooling effect will help the condensation of the fresh water. Under the sun, the black mateiral were the salt water pools will be hot enough.
Fill the bottom with seawater as it dark and the top is see through the sunlight will heat the bottom water. The warm water will start to evaporate the warmer the bottom the better. The steam goes up and if the cone top is cooler it will codense and fresh water will drip to side ring connected to the drinking bottle. Don't put the device in the water you cool the bottom and stop the evaporation. If anything keep out the water and put it on warm Sunny dark surface to keep the evaporation going. From time to pour cool seawater in the top t cool it and condenses faster. Ever boiled pot of soup? If you cool the bottom it will stop evaporating
Not just the sunlight, but the heat from the water if it is different than the heat in the air should be sufficient to cause condensation as well This is wild to me. The only drawback of desalinization has always been rust and corrosion on parts. There is so much plastic floating in the ocean. What if we were to smelt it down into these and send them to people who need them?
You can't just melt (not smelt) plastic that's been floating around degrading in the sunlight for months or years and reuse it. It's garbage. Most plastic recycling is a myth and doesn't work to make high quality materials like you'd need to make this still. Plastic recycling can make crappy plastic you need for bulk materials like, solid plastic benches or some other stuff.
What a great invention! Every life raft should have half a dozen of those included. I think I would investigate the idea of making one twice the size as that would give waay more than twice the fresh water production- can't see why there is a need to have such a tiny one?
Maybe larger walls would make it more liable to damage by strong wind.
Trouble is, surface area increases by a squared factor and the air volume by a cubed factor so there maybe be an optimum size… who knows though… maybe huge is better!
if you make it too large, it will become less efficient. The larger the water droplets get, the more likely they are to fall back into the water that is being desalinated. You'd want to have multiple ones, rather than larger ones.
In the past I've seen inverted cones with water collected at the apex into a container underneath so dripping condensate would naturally follow the shape by gravity. I'm not clear on how this one operates.
It looks like the condensate which is fresh water, drips down the side, and is collected around the rim of the still
Very valuable bit of kit but how long does this equipment last?
Amazing design.
instead of a parallel round bottom it should have a slope so that all the water gets collected effectively
I saw a KZhead documentary of a guy that was stranded in a life raft for a few months. He survived by using 2 of these and eating raw fish.
What is the approximate cost and the water production rate?
Using around 0.5-0.75l of water in a crude homemade solar still I made almost 5 ml of water which is... yeah it's quite a small, tad amount of water but atleast its enough to keep me alive for another coupke of minutes when I'm stranded in the ocean. Basically to get enough water (Like IRL plants) you nead atleast 5 HUGE plants to make a good amount of water in 1 hour.
having one of these in difficult situations must put you on the other side of the line of life :0 BTW idk why guvernments around the world are not investing in massive methods of extracting water from seas, is practically endless and the sea levels is not going down, so processing it must be priority to preserve currents sources of non-salted water which unfortunately we cannot keep consuming as it would just accelerate our process of extinction, they keep alive jungles, forests, even deserts, and we are draining all those, idk, just a humble opinion.
Going on a trip to Hawaii this spring and wanted to learn how these work for my first time flying over the ocean haha. Yeah I know flying is safe but if something did happen I would be pissed if I didn't take the 5 min to learn. I'm pretty sure over ocean flights keep these I'm their life rafts.
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They most likely don’t have these. If anything were to happen, the aircraft is in constant radio contact with Search and Rescue. Nothing will happen. Relax, enjoy the flight and have a wonderful time!
If you crash over the ocean you're dead buddy.
did you take a fire extinguisher?
I wish you would have tasted it to let us know how its working.
I can visualize several improvements which will enhance production and also enhance collection.... nice concept though.
Two questions: 1. Will this work on a larger scale? 2. This will remove almost all the minerals, how about micro-organisms? Thank You. Excellent presentation.
1- Larger scale would need a better source of energy, like a solar mirror. This is an emergency water supply only. 2- you do not need to eliminate 100% of the salinity, 0,5% salt concentration is actually healtier in the situation that it is designed to be used. Most of the microorganisms are killed by the sun's UV rays, however you should drink all the water, storing it will let them time to reproduce and make you sick.
It will remove the minerals and kill most the microbes, given your water source isn't too bad. I have no idea how they put the minerals back.
Don't forget UV spectrum of the light. It's one of the best possibilities to make drinking water safe.
You went through all of the work to make this video but don’t actually drink any to confirm to viewers that it tastes ok?!?
How much water can it produce on a sunny day?
It should work better while in the water correct? I believe the general concept requires hot moist air and a cool surface to condensate on
Probably on land as it heats up more. Being in water is cooling down the water you want to heat up.
… Or release an enzyme into the pool of plastic that breaks it down and homogenize the structure into something that could be used for this? We are just stuck in our boxes, but the ocean has a lot of things left to discover.
I wonder if it tasted alright. Hoenstly am worried all that handling might have polluted the freshwater with sea water
If they replace sections of the plastic with thin wafers of magnifying glass and find a more efficient way from getting the fresh water from the sides, I but it would be so much better.
Christ, I thought that place looked familiar. There is no way you're in Polace, I used to go there all the time as a kid 😂
Does the water taste any good? Is there any salt in it still?
For life saving water, I'd say that each person needs THREE of these as a minimum number.
And you would be incorrect
How was the taste? Any residual salt taste?
US Navy filters water either by evap or reverse osmosis. We weren't allowed to run the water production until we were in somewhat clean water. One should not use this device near land.
Looks like potential life saver. Great gadget!
I love it and it works!
It is
How do you know? He never tasted or used the water and it could be contaminated due to faulty design. Worst review ever, lol
@@Obliticus I think the review was just to show it works
@@cjadventures8840 And we really still don't know if it does after watching this, do we?
Waaww...its knock my sense about the idea..i kind of wonder to use photosinthesis reaction to produce it too??
Making it float seems a bad idea because the cold water would slow evaporation.
I wonder how you keep in clean with all the minerals and salt? I am honestly curious!
Depending on outside temps and activity level, a human needs about 2 liter of water per day. Probably more in an area where a solar still would actually work. Looks like each human would need four of these units to survive.
seems to lose a lot of efficiency due to the condensation on the transparent plastic film, the micro bubbles become like a super reflector.
This still was invented just before or during WWII and used by the NAVY in life boats.
I'm so inspired by your content! 🙏
Thanks 🙏
I think it works better in the ocean rather then your boat because the bag holding water is underneath easier to drain. When on your boat the bag was level water had hard time draining. think I am getting 1 works good
I had the same idea. The cool thing is if you had enough inflatables and gave it a structure of super black body pillars running through it and supporting it you could layer it. Have multiple layers of water being heated by the sun. I think one issue is the refraction the condensate makes. You could fix this with a super white body passive cooling. Basically even in direct sunlight this material is so reflective of light and IR energy it can passively cool. It takes direct contact to transfer heat into it. Have this in a cone at the top and let it build the condensate there. Or in my idea it would be dispersed through the layers in a grid pattern. Then you could float these on any sea or ocean and collect potable water. Though you could probably just drink it i imagine if the system stayed wet for weeks some bacterial growth would form in the distillate tube. Its just water vapor but some dust might get drawn in.
It needs to be in water to have a condensation surface... else it would evaporate again.. if you place it on wet sand it would also work.... I think (:
The bottom isn't open to the water. it fills via the open bag/scoop @0:40. The bottom is black to heat up with sun light. This increases evaporation that condenses on the cooler top and trickles down into the side pocket to be collected.
How does it taste?
Can you try add a black plate that float close to surface and underneath the floater. The purpose is to increase the temperature of he water near the surface which will increase the vapor and might increase amount of water it produces.
Solar stills are easy to make. If you don't need one of these for an emergency life raft, save your money. These are crazy expensive.
Just imagine how much water you'd have if you left it out overnight!!
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Overnight? It need the sun to produce condensation. 😂😂😂
It need to be in the water, the cooling effect assists condensation
Conductive ink or carbon felt bottom of this solar still powered by floating solar panel would turn it into a kettle styled still.
Haven't seen one of those in 30 years
no test drink? there was one guy who drifted for 40 days or so and he had two of them and wasnt much happy with them, said better collect rainwater
Distilled water is safe to drink But... is just hydrogen and oxygen and nothing else. Without important minerals, like calcium, sodium, and magnesium... flavor is flat.
Thanks!
Wonder what it tasted like.
I guess if your on a emergency raft its better then nothing. But on a boat your better off with a RO system with a back up manual pump.
That should be on every boat emergency kit, seriously.
HOW DOES IT TASTES ?
Looks like it would be enough for one person to stay alive. Not a group with the exception you had more than one. Then you have to factor in cloud cover. I guess worth having in an escape raft.
With 20 of these working non-stop, a person can potentially have drinkable out in the sea and survive.
I learned how to build a solar still when I was in Boy Scouts.
Awesome, where can I buy one for my sailboat?