DIY SOLAR TUBES EVACUATED VACUUM TUBE SOLAR HOT WATER Boil water with the power of the SUN

[thesimulacre]

Anytime I wonder if I could DIY something, you two are ALL OVER IT. <3 you guys, really.

[SeeTheWholeTruth]

Couldnt you use a basic deep food canner, and utilize a jar within a jar, sealed(steel weave putty), then "can" them in the pressure cooker, to make the vacuum seal? Also Im curious if there is a DIY method of getting that coating that gives the higher infrared spectrum with the interior bottle, rather than the black?

[M1ST3RHYDE]

When do we get to see the water boil?

[Mrzoo2021]

Hey Dan I was just thinking, would it be possible to Fill the vacuum with a gas like between double pain glass window and would it make a difference.

[espejocielotierra]

Thank you very much for sharing this valuable information.

[slavkok68]

About vacuum. You need recent vaccum to have benifit of it. If you don't belive just put two same devices on the sun, one without vacuum (but closed) and other with just 1/10 of atmosferic pressure. The result is near same. The change is introduced probably beacouse of watter vapour has higher transfer ratio as air and air is not dried. The real benifit of vacuum start's under 1 torr vacuum, and that's hard to maintain in hobby system.

[mmaaxx1198]

How does this produce heat?

[Jabarcher13]

your great man.

[craftmatic2]

I'm not sure how much the vacuum is worth it, but I think that if you half the amount of air in the tube it would half the rate of conduction to the outer wall.

If you could get a half-bar vacuum it would be twice as good as air. Probably breaks most glass though, because that is around 7.25psi negative...

A 15% vacuum, i.e. 85% of atmosphere, would be around 30% better insulator than 1 atmsophere air.

After 50% vacuum, is exponential increase in insulator, but surely impossible to DIY.

[caminante773]

What if instead water you put air?, will it heat the air also?

[Bubblytubebob]

I think your on the right track. I've often thought of a way to create a dependable vacuum Tube. You almost need an old lightbulb factory. I'll be watching your future progress. I used polycarbonate to cover my panels. they got so hot they melted two inches deep into blue SM foam in Half hour.

[xexorz]

holy implosion hazard batman.

I dunno what the rating is on a vase from walmart :-) Hopefully somewhere near 1 atmosphere.

[1dennydog]

You lose the vacuum when you drill the hole!!!!

[lsucowboy]

The other technique you describe for creating a vacuum by lifting the glass isn't going to create much of a vacuum. It might be 1" H2O, which is -0.036 PSI. That is hardly a vacuum. There are other ways of creating a vacuum though that I'd like to see you explain for people doing projects. If you'd like some of the techniques, send me a message and we can discuss them.

[kokopelli314]

strips of wood to raise the tube to even up the resin...FANTASTIC!

[raulgrave]

Great video, thaks 4 sharing.

[kozybearcat]

This is silly. The vacuum created does nothing useful. You need 10,000 less air than atmospheric to do anything. This level is not really do-able by a DIYer. Do yourself a favor and just skip the vacuum step.

[GREENPOWERSCIENCE]

Nope, any vacuum contains less atoms, less atoms equal less conduction, less conduction equals greater heat retention for this process.

watch?v=AFwG1RPbxlc

The professional tube in this video has a vacuum created simply by the heat making glass process then from cooling. It boils water in plain sunlight.

[junkymagi]

@GREENPOWERSCIENCE One good source for a vacuum pump is an old refrigerator or freezer. The freon pump can be used to pull a powerful vacuum. Might want to make sure you have a vacuum gauge if you use one, otherwise you'll have a problem with implosions, hehe.

[thundergod989]

@GREENPOWERSCIENCE Yes, but in -40'C weather or with heat expansion... that is where you will see the advantage of proper vacuum. If you are using glycol (ethyl or propyl) to run the system at a higher temperature or in subzero conditions then you will see an even greater difference between a properly evacuated tube. One way you could effectively increase the vacuum here is by putting a torch to the tube while pumping... when the temperature comes back down you will have more vacuum.

[kozybearcat]

@GREENPOWERSCIENCE

This is incorrect. the thermal of conductivity of air is unchanged until you reach about 1,000-10,000 times less than air pressure. You are experiencing insulation due to the outer tube much like wrapping a hot pipe in insulation. But the vacuum is not improving the insullation. True vacumm tubes have a stagnation temperature of about 500 degrees F. You seem to struggle to get to 140 deg F.

[imachavel]

@GREENPOWERSCIENCE

you don't need any sun light if the vacuum is as pure as the vacuum of space. in a pure vacuum, with no pressure, water doesn't resist in a liquid form, it turns straight from ice into vapor. that water should have boiled at room temperature. what is amazing to me is that there is so much pressure in our atmosphere, that at the right temperature water will retain in a liquid form just because of air pressure. it isn't how little pressure is in a vacuum but how much pressure e

[datzfast]

@kozybearcat i cant believe you can say that, where did you hear that?

[solerso68]

@kozybearcat The "10,000 less than air" firgure you have there comes from the old electron vacuum tube industry. And even within that industry the 10,000 less than standard was about QC and high performance over a long time. Im using some electron tubes made in the 50's (for instance).But it was not required to simply make working tubes. There is a lot of hoodoo mythology around electron vacuum tubes.

[catatonicable]

How do you heat the water exactly.?

[PuciferSam]

Check out follow up or part 2..... watch?v=1_NOT2VZW6E

PùciferSàm

[stevenscowboys]

all this work to make hot water lol

[jamesfromyesteryear]

Dan, if you play a blowtorch into a cooled glass vase just before you drop the vase down the contraction will suck the epoxy right up into the vase without any adjustments.

[Patriotgal1]

Another EXCELLENT video from D&D!!!!

Hint: try sand-blasting the glass parts, where you want them to bond to the resin. This allows a much firmer bond! GREAT WORK!!!

[Perfectg]

Instead of using a vacuum pump (as many folk don't have access to one) then you can simply heat the vase with the hole drilled in the resin open and then put a stopper in it. As the air inside cools you will end up with a vacuum. You can almost create what ever vacuum you need using this method easily enough to implode your vase so go gentle to start with. A little bit of water inside acts as a vacuum lost indicator as water will remain vapour in a vacuum but condensate out if you lose it.

[vmelkon]

@Perfectg The vaccum would then depend on the temperature you use and ordinary glass has a tendency to crack if heated or cooled too quickly.

[jab0805]

You gave me some super ideas. thanx!

[mentaloasis]

6:09 Nice catch, lol.

Great videos by the way. You have inspired me to try out a few of your ideas on my own home. Keep them up! Hope to see more.

[the1969info]

Hi Dan, thanks so much for your great videos, I can't get enough of them. I have seen other videos how solar evacuted tubes work. Could you put a vacuum sealed copper tube into the inner bottle and will it heat up. If so could you use it in cold weather to heat your vehicle while your indoors or have a long enough copper tube, you could attach it to your home like a solar heater. The heated tube would be exposed indoors, the ceiling fans would distribute the heat?? Thanks again, great videos!!!!

[GREENPOWERSCIENCE]

Thank you for the cool comments:-)

I think you would need a much larger surface area. I think large sheets of double glass could do it. Consider the coroplast heater with a glass cover

watch?v=SF_mEoFRSAQ

[BARTSIMPSONXD]

@GREENPOWERSCIENCE Pleace add subtitles in SPANISH ;)

[theracemixer]

@GREENPOWERSCIENCE

I know this is an old video but can this method be used as tank to hold hot water for a boiler? What i mean is by large scale it can be used to hold 100L + of hot water.

[mririch1971]

All of your you tube videos are great, have you ever thought about sending any of these to mother earth news ?

[Mecanome]

Also, there has been comment on using hydrogen as this wouldn't require a serious vacuum. As I understand it, hydrogen, in terms of thermodynamic characteristics, is the substance of choice for use in stirling engines (practical characteristics aside - leakage, reactivity etc). If hydrogen was a heat insulator then I don't believe a stirling engine could operate using hydrogen.

[privateworldofwarft]

So old school computers used somthing like this back then?

[grayjc]

Dan, thanks for the information. I made one of these today (2 inch glass vase inside of 4 inch glass vase) and everything seemed to be fine, except I had some contraction with the epoxy and some cracking began in the epoxy. Not a problem since I used more epoxy to contain the cracks. I pulled a vacuum (25 in Merc) and let it sit for while in the garage. After about 1 hr the whole thing emploded. Sorry I wasn't there to see it, but I did hear it. Will try again later with thicker glass.

[GREENPOWERSCIENCE]

The vacuum does not need to be that strong. The first one I did, the bottled popped loose and flew to the bottom shattering the glass. That may be what happened. You need a rim on the inner vase for the resin to lock on to. A rimless inner container will simply pop loose as resin has poor surface adhesion to glass. The method in this video is, the vacuum sticks the outer vase and the ridge locks the inner one in.

If they pop loose with a vacuum, they accelerate very fast.

[grayjc]

My suspected the epoxy as the culprit. As it dryed it shrinks. The shrinkage caused excesive loading of the end of the large vase. I believe it yielded there and cause the emploding. The inner vase was still held within the epoxy mount as it had a lip to retain it. Oddly, the vacuum is still much lower then a common thermos bottles (10-3 to 10-2 Torr). I was still in the single stage vacuum area (10 to 100 Torr) which hardly qualifies for a vacuum according to Wiki.

Keep em coming! ty

[grayjc]

2nd attemp worked ok for about a day. Day 2 the noise started. You know that cracking sound that is very unnerving. Split second cracks that make you pull away thinking it will implode. Oddly, there was no vacuum on the container. I finally figured out that the epoxy was breaking loose from the glass at about 1/8 inch per cracking sound. I've moved on to Borosilica glass tubes and heat pipes and having fun thanks to your videos.

Appreciate the DIY. John

[grayjc]

Lastly, please don't use the glass vases at Hobby Lobby. They look very thick, but it's super thin in the center. Give the vases a pinch to check the thickness. I'd recommend beer bottle thickness which feels like 1/10 inch or 2.5mm. thanks

[HeavyDemir]

Hey Dan, try to run your steam engy of that. It would be cool to know if that will work.

[1Tane55]

Great Dan thanks!

Gives inspiration for making a collector with double pane windows and a car radiator in an insulated box with glycol and a heat exchanger. Get some temps below 32F. Might also use a thermostat to control temperature need a bypass or bypassing thermostat. Looking for enough temp for 105F = 60F over ambient. Trying to get that may need your Lens or a reflector. Interesting project let you know how it works out.

[FearTurtles]

Double pane windows often have a coating on them that filters out the IR light which you are trying to capture. Probably the best way to insulate between the glass would be to fill the space with hydrogen at atmospheric pressure.

[HeavyDemir]

help me out here cos I dont get it. How can hydrogen insulate better then uh,, nothing ?

[FearTurtles]

Have you every tried to create a space of "Uh,, nothing and then keeping it sealed? Hydrogen is about as close as you can come to having nothing and it can be done under atmospheric pressure. The problem with Hydrogen however is that it too is hard to keep contained. So a gas such as Argon would actually be better.

[WolYou]

Refilling vacuum? Lol.

[slinkee2k]

Beautiful! :) But why not just mold the resin with a tube already in place? You could put the tube thru the casting mold and seal the around the tube with clay, just like with the bottle neck. :)

[gabrielou812]

thank you for all of your work and sharing it!

could you also clear acrylic pipe that works with regular scd 40 caps for an outer shell, or are there drawbacks to plastic?

[endyxy1]

Damn! Wish I could understand you. I am hearing impaired and there is no captioning provided for me to learn about this great invention.

[pupplesan]

You need a REALLY high vacuum to get much real benefit. I suspect you would see nearly identical performance using the double-wall setup without any vacuum at all.

[Mecanome]

This guy is right. Without a serious vacuum, heat will convect from the core to the exterior. Also, all that epoxy and its surface contact with the core will again provide a great method for heat conduction away from the core. Read the Thermos article on wikipedia for a real understanding of this project.

[Mecanome]

sorry, this was supposed to be a comment to purplesan on the next page. He stated that this is unlikely to work any better than the non-half-vacuumed version.

[jeffmaglio]

Great quality thanks for the info Mark Tahiliani

[chrisleblay]

Hi Dan,

Congratulations ! I am thinking on system to store solar energy and a "Dewar" vase is the best as you just demonstrate. I think a good system will be to make hot steam with parabolic system and exchange heat in a dewar vase that contain "molten salt" after that take the energy out with a system. Are you going to do this kind of system that will get definitelly ged rid off poverty in the world.

you are a very good man .

chris

[sonofhendrix]

Great i get it now. Because their is no air outside the bottle the heat can't propagate back out to the environment.

[sonofhendrix]

ahh i think i get it. Because its a vaccume, it lowers the pressure so water can boil at a lower temperature.

[GREENPOWERSCIENCE]

Hi,

The vacuum is outside the bottle and offers great efficiency preventing heat loss. The water still boils at 212, it just has an insulator that allows sunlight to enter through the outer shell and absorb to the inner container. This allows heat to build without being leached into the outer environment.

[tallyhoroad]

Definitely would love to see a comparison between your vacuum solar unit and a regular beer bottle with the same black paint on the back. Great job guys!

[idahoviewer]

Also, with a double wall and NO vacuum to compare the to methods.

[crock703]

Hey, this is a question off topic about fresnel lenses...

I'm curious what materials have proven inflammable (at least w/ the "wider" lens.) Will something like a space blanket or similar material reflect enough light to prevent igniting after prolonged exposure?

[Procrastinatathor]

You do like to play with sunlight don't you?

[overunitydotcom]

Cool or should I say "hot" design! ?

Please let us see how fast you

can boil the water in a new video please.

Please come to overunityDOTcom

and report further please.

Substitute the DOT with a real "."

Many thanks.

Regards, Stefan.

[B0thergirl]

What is the point of this project? What is it supposed to do?

[MinTrinidad]

You could use a vacuum cleaner to gain the vacuum, Just that you will need to make an adapter for the large diameter hose.

[pubtor]

great job

[JavaLessons]

Wouldn't it be better to offer the black side to the sun, to avoid reflection ?

[politicaldenali]

I'm always looking forward to new greenpowerscience videos. Great information again! Thanks. Keep them coming.

What about using one of those aluminum beer cans? Budweiser Lime, paint with grill paint.

[MoonSpyStudios]

Good vid Dan,,

I always enjoy your informative vids man,,

I really liked the table saw circle tip!

Bill- Ohio

ps check out my channel for some cool stuff too.

[Aracuru]

Erm..pardon my question, but is this particular device even used for? Basically, what's the point?

[GREENPOWERSCIENCE]

Hi,

The can boil water just by placing them in the sun.

[Aracuru]

Wow! That's awesome, it makes perfect sense now. Thank you for the prompt response.

Haha, using the same principles there are 'attack' satellites in space that simply "spray paint" other satellites, thus heating them up and eventually destroying them.

Awesome videos by the way. If you were to put all your videos on a CD, I'd buy it.

[pinkytm1]

It would be nice for sterilizing water while camping or in poor countries.

[longbeforedawn]

Hmmm. Very interesting. I saw some of these, well, an array of big long ones, put on a roof to heat water.

[BILLGATES1277]

Brilliant BTW!

[BILLGATES1277]

I want one. Do you sell the completed design?