Thanks, having a heat pipe is like having a heat superconductor. I needed an object with a very even temperature for an upcoming video and heat pipes fit the bill. I wonder if they could be combined with your rubber-band refrigerator to increase the efficiency?
Interesting... Watching this connected the dots of how the old school single pipe steam heating systems work. Bleed off the air, wait for the steam to condense and form a vacuum, then you've got good reliable heat transfer. Cool stuff.
+MadOnions Yeah, I've been thinking of making a pipe with a radiator on top to see if you could effectively heat air from a supply that would normally be impractical. (Heat trace wire or something similar)
Great demo! I've been experimenting with both pulling vacuum and just boiling off water in diy heatpipes to set them up but not sure what is simplest. I've also fiddled with a better demo where center section is glass. It is hard to get a transparent wicking material though as I want to show the transfer of liquid back to hot end also when horisontal.
Great video. Perhaps this is how you made your heat pipe, but at some point I inadvertently discovered that you can make a trivially simple version by taking the capped pipe with valve you have in your video, and putting it on a burner with a bit of water in the bottom. When the water boils, you close the valve. The steam condenses, leaving the tube at significantly lower than atmospheric pressure. I didn't get a super strong or accurate vacuum, as you would with a vacuum pump, but its easy and it works! School of hard knocks: be sure to hold the pipe with a potholder as heat moves up the pipe from the burner really quickly!
You got it bang on! If you let the whole pipe get up to ~100c (lots of steam coming from the valve) before you close it you will get the hardest vacuum possible (in the presence of liquid water) for the current temperature! At 100c you have steam and water at atmospheric pressure, as the temperature drops and the steam condenses the the pressure rides along the gas/liquid line on the phase diagram of water until you hit room temp. I also learned the hard way that a heat pipe is still a heat pipe even if it is open ended, the second time I filled this one I was wearing thick gloves.
Thank you! This is really important tech. With medical syringe i have experimented water in low pressures and it is really interesting. Water actually starts boiling in lower low enought pressure at room temp! I want to build active system that has pump just like phase change system has a compressor.
The dimensions don't actually matter much and the pressure is determined by the temperature. As long as the tube is sealed while filled completely with steam and water (no air) it will turn into a heatpipe.
I mean ...it's a copper pipe with a small amount of water in it and a valve on the end. Copper because of high conductivity, valve to close once the water inside is boiling. That's literally it.
how to roughen the inner side? Also, I want to cure a film, at 200C, coated with silicone resin, and moves from coating point to a the film winder. I use hot oil ms tube grid over the moving coated film. I have wound the M S tubes, that conduits the hotoil, with a copper wire. not much heat transfer change compared to non cu wire wound one. Can you a suggest any other construction to improve aet transfer from the hot oil pipe to the film?
How did you make it. I want to make a homemade cpu cooler and I would like to use this in my project as Chinese heatpipes are not available for delivery in my country. Pls tell how u made it, I would love to make some and use in my homemade cooler.
I wonder if an existing sidewalk could be kept snow/ice free with heat pipes installed through holes drilled at even intervals,with the lower end of the pipe below the frost line,and the upper end in the concrete of the walk. I envision a working fluid with a low boiling point in the pipe.
@@NickMoore do you happen to know of any places to buy a copper heat pipe? and do those that are able to be bought already come with a liquid? I want to use my own liquid, methanol, in the heat pipe. How would i go about adding my own liquid to a bought heat pipe?
I want to do a powerful heat pipe from old car's radiator and aluminium spiral so I have to connect them with a pieces of PVC or silicon tube to prevent corrosion. Will this idea work or I must solder the parts together?
Knocked another one out of the park man. I don't think many folks appreciate how nerdy HVAC and related trades can be, this is a great example. Add a bunch of pumps, pipes, pids, coils, controllers, fans, sensors, solder, cat hair and bacon grease condensate and you have yourself a good ol' time. :)
+jcims This is my first stab at refrigeration and it was loads of fun, there are a bunch of projects I want to mess around with now. Like can liquid nitrogen be generated using only regular refrigeration equipment found in household appliances.
How did you figure out how much water to put in the Heat Pipe initially? Did you heat the pipe up to 100C and then close the valve? Also what is the glass tube device at the end of the video? Was that some type of prototype?
+dano3829 I figured out the volume of water by trial and error, it only needs to be about 1% filled over all. I heated the pipe until steam was leaving the valve and then closed it because that is the only way to know that all the air had been flushed from the pipe. The glass tube is a another heat pipe that shows what's going on inside but it doesn't work very well. The glass walls don't transfer heat to the air around it so I wasn't able to use it for the main demonstration.
I think it changes the lowest operating temperature but probably is less efficient because water takes more energy to transition from a liquid to a gas.
+Victor Gaíva If you can think of a sub that would like it go ahead and post, I put a short write-up in /r/physics a few weeks ago and got a positive response. Glad you liked it!
I think a great demonstration of a heat pipe's heat conductivity would be to submerge the low end in a pot of boiling water; The water should stop boiling, and might take a long time to begin boiling again... if it boils again.
I guess this is the same as how a reflux column heats up on an alcohol still since there's pretty much mostly vapour in the column with a few drops condensing on the sides. As soon as my still heats up at the bottom, it's a matter of a minute before the top of the reflux cloumn is the same temperature.
+Jim Griffiths I was thinking the same thing as I was filming this video. As the steam makes its way up the tube it can get surprisingly hot in a short period of time, even when it is at atmospheric pressure.
Hello, we are french students currently working on a project that involves heat pipes. We find your video very interesting, especially the whole "homemade" aspect of it as we would love to recreate a heat pipe of our own ! Could you give us more information on how you built yours ? Thank you :)
I've asked this question before with mixed responses: Does the orientation of the heat pipe matter ? i.e. if the heated end was elevated higher than the ambient end would it still work this well ? my hypothesis is yes orientation matters, but i cbf building a heat pipe to test. .... also if orientation does matter would putting a wicking material inside the pipe along with the fluid help? Also does a wicking material help at all? so many questions !!
I don't know a lot about heat pipes, but the modern real ones used for cooling processors rely on capillary action, as Nick mentioned, so I would say no, it does not matter. But it does for much older ones as well as for the DIY ones. Nowadays CPU and GPU thermal management is starting to utilize vapor chambers. The same science is at work, but a vapor chamber is essentially a 2D version of a heat pipe. The disadvantage is that orientation does matter, I think.
+Power Max you got it. If there is a wick material then the orientation doesn't matter, my heat pipe has no wick and so relies on gravity to return the condensate to the hot end. I never heard of vapor chambers while I was googling about pipes, there was a flat/square example on the wiki page but I'm not sure if it's the same thing. Thanks for the tip!
Nick Moore With a wick it acts like a wire, but for heat. Without a wick, it acts as a thermal diode. Add a section of a thermal insulator, such as glass or plastic, then the diode will have much better characteristics. It wouldn't be hard to design something that tilts when the water boils in a tube and shifts the center of gravity. If this was mechanically coupled to another heat pipe such that it moved one end into, or out of a source of heat, it would work like an electric relay, but for heat. This could be used for an art installation.
+hamjudo It sounds like a drinking bird toy. It works by moving a fluid from one end to the other by evaporative cooling. Once the top end has enough condensed fluid it tips and resets itself.
Nice, like the valve at the top. I am just curious, but if there is a trap at the top to collect all of the water, how long would it take for all the water to move to the top in a similar test?
There is nothing extra inside the pipe just the water and steam. Generally as soon as the steam makes it to the top of the pipe is condenses and starts to drip back to the bottom. If you overload the pipe with too much heat all of the water will boil and the pressure inside the pipe will rise very quickly. I don't know how quickly it could be done but doing so can cause the pipe to burst.
I am interested in moving the water to the top and keeping it there. I know the fundamentals of a heat pipe, as shown in this very good demonstration of yours. I am working on my off the wall invention of moving water to higher level and having a hard time finding the the rate of fluid move from one end to the other, in heat pipes? And i was wondering if you could give ball park guess on the flow rates. this something i have been wondering about for a long time, and if it is worth it to making this invention? Any information will be greatly appreciated.
As far as I know the steam can move at or near the speed of sound but you could never use a heat pipe (or something like it) to move water efficiently. The energy required to boil it is significantly more than the energy needed to just lift it by conventional means.
Will u please tell me and show the experimental setup, how to creat a vacuum in a tube(copper or glass) and fill its half volume with water and seal it without leak
The tubes are only filled about 1% of its length with water. To make the vacuum and seal it I first add the water then heat the bottom of the tube until there is steam leaving the top of valve. Then I close the valve and let the tube cool, as it cools the water will condense back into a liquid and pull its own vacuum.
I wonder how big I can make these, and how thick of wall I would need. I'd like to try making about a dozen of these, six inches or so in diameter, maybe 15 feet long, and bury them 10 feet in the ground and put the top ends in a heat exchanger. See what kind of heat we can dump from a heat pump into the ground with these suckers.
Unless you use a wick material inside theses tubes only move heat upwards. The pipe only has to hold up to 14psi of vacuum so anything that is made to hold water or compressed air is strong enough.
A 'real' heat pipe you would find in a CPU cooler has a sintered powder coating on the inside but mine do not. The sintered powder acts as a wick to return liquid water to the hot end of the tube when it is not mounted vertically.
I think a very fine mesh of copper wires or some kind of heat resistant fabric would also work but not as well as the powder. With a really good wick I think a heatpipe can even work upside down.
Glad you like it, these heatpipes were one of my favorites just due to their simplicity. Any one can build one and they are fun just as a "WTF" shop decoration.
Thanks for this! I never imagined that they were so straightforward..for some reason I imagined that it was necessary to use more volatile substances with lower boiling points. I guess that would help broaden the operating temperature range, but if up around water's boiling point at that pressure, it's all good. Do you have any recommendations for determining ideal liquid volume relative to pipe volume and working pressure?
+icarus901 Water is one of the best working liquids as long as you are between 0 and 100c, it takes more energy to boil than any other liquid. The only time you need to get into exotic working fluids is if you are into extreme temperatures (hot or cold), some of the hottest heat pipes even use metals as their working fluid!
ah, so essentially pick a convenient substance with the largest energy delta in the vaporization direction in its phase change diagram? (for target temp+pressure)
If you had a taller water column to make better thermal contact with the hot vapours you could probably immerse 5 or 6 heat pipes in the water to dissipate the heat. Though your bong might look like the Voyager space probes.
This is perfect for heating a house up north you can suck the heat out of the Earth's core easy with this why spend money and energy to heat a house if you can just make heat wells and if you had a internal water pump to pump the water from underground to above ground you can use this to cool your house too I bet the water pump will use less energy than a normal air conditioner that uses a air compressor
A really reliable heat engine can be made easy too a simple pelton wheel can fill up with water on one side and spin a generator the more heat you suck out the ground the more electrical power you get so heat your driveway never have a icy driveway again
Great demo!
Thanks, having a heat pipe is like having a heat superconductor. I needed an object with a very even temperature for an upcoming video and heat pipes fit the bill.
I wonder if they could be combined with your rubber-band refrigerator to increase the efficiency?
Very cool
If you switch from water to acetone it can get 95c cooler!
A crossover show? That would be pretty fun but he has all the toys, I shoot all my videos on top of the deep freezer and next to the furnace.
@@NickMoore did he ever reach out?
Awesome sir
Interesting... Watching this connected the dots of how the old school single pipe steam heating systems work. Bleed off the air, wait for the steam to condense and form a vacuum, then you've got good reliable heat transfer. Cool stuff.
+MadOnions Yeah, I've been thinking of making a pipe with a radiator on top to see if you could effectively heat air from a supply that would normally be impractical. (Heat trace wire or something similar)
Perfect! Thank you!
Well done Nick 👍😎
Learned something new again. Thanks.
Glad you liked it, it was a surprisingly easy build and gave excellent results!
Great demo!
I've been experimenting with both pulling vacuum and just boiling off water in diy heatpipes to set them up but not sure what is simplest.
I've also fiddled with a better demo where center section is glass. It is hard to get a transparent wicking material though as I want to show the transfer of liquid back to hot end also when horisontal.
Great video.
Perhaps this is how you made your heat pipe, but at some point I inadvertently discovered that you can make a trivially simple version by taking the capped pipe with valve you have in your video, and putting it on a burner with a bit of water in the bottom. When the water boils, you close the valve. The steam condenses, leaving the tube at significantly lower than atmospheric pressure. I didn't get a super strong or accurate vacuum, as you would with a vacuum pump, but its easy and it works!
School of hard knocks: be sure to hold the pipe with a potholder as heat moves up the pipe from the burner really quickly!
You got it bang on! If you let the whole pipe get up to ~100c (lots of steam coming from the valve) before you close it you will get the hardest vacuum possible (in the presence of liquid water) for the current temperature! At 100c you have steam and water at atmospheric pressure, as the temperature drops and the steam condenses the the pressure rides along the gas/liquid line on the phase diagram of water until you hit room temp.
I also learned the hard way that a heat pipe is still a heat pipe even if it is open ended, the second time I filled this one I was wearing thick gloves.
I love how simple the method is. It is really funny we got the same heat transfer lesson, too.
Ha ha - love the trap for new players at the end!
Thank you! This is really important tech. With medical syringe i have experimented water in low pressures and it is really interesting. Water actually starts boiling in lower low enought pressure at room temp! I want to build active system that has pump just like phase change system has a compressor.
Great stuff. Would be great to know more about the production of the actual pipe - pressure, volume etc
The dimensions don't actually matter much and the pressure is determined by the temperature. As long as the tube is sealed while filled completely with steam and water (no air) it will turn into a heatpipe.
Great video, from way back in 2016. No idea how 14 people can dislike this video.
Maybe they don't believe in thermodynamics?
Nice
Nice, thank you!!
Hi Nick, did you have the press of heatpipe until go throught water --> vapor -- condensed to water again?
Great presentatio Nick. Would be awesome if you show us how you designed this, what kind of materials you selected and why etc.
I mean ...it's a copper pipe with a small amount of water in it and a valve on the end. Copper because of high conductivity, valve to close once the water inside is boiling. That's literally it.
Would it be possible to make it a spoon to pick up very cold ice cream ?
how to roughen the inner side? Also, I want to cure a film, at 200C, coated with silicone resin, and moves from coating point to a the film winder. I use hot oil ms tube grid over the moving coated film. I have wound the M S tubes, that conduits the hotoil, with a copper wire. not much heat transfer change compared to non cu wire wound one. Can you a suggest any other construction to improve aet transfer from the hot oil pipe to the film?
How did you make it. I want to make a homemade cpu cooler and I would like to use this in my project as Chinese heatpipes are not available for delivery in my country. Pls tell how u made it, I would love to make some and use in my homemade cooler.
Can a compact Air conditioner be made using these novel pipes? what could be other possible uses apart from that as a heat sink?
I wonder if an existing sidewalk could be kept snow/ice free with heat pipes installed through holes drilled at even intervals,with the lower end of the pipe below the frost line,and the upper end in the concrete of the walk. I envision a working fluid with a low boiling point in the pipe.
Fantastic demonstration. Thanks!
Thanks!
@@NickMoore How much water/liquid is used in the heat pipe? How do you know how much to use?
@@shivstueber4587 Very little, maybe 1% filled but I think you can use more.
@@NickMoore do you happen to know of any places to buy a copper heat pipe? and do those that are able to be bought already come with a liquid? I want to use my own liquid, methanol, in the heat pipe. How would i go about adding my own liquid to a bought heat pipe?
thanks bro . good job
Thanks!
I want to do a powerful heat pipe from old car's radiator and aluminium spiral so I have to connect them with a pieces of PVC or silicon tube to prevent corrosion. Will this idea work or I must solder the parts together?
How much water need to be filled in the tube?
Knocked another one out of the park man. I don't think many folks appreciate how nerdy HVAC and related trades can be, this is a great example. Add a bunch of pumps, pipes, pids, coils, controllers, fans, sensors, solder, cat hair and bacon grease condensate and you have yourself a good ol' time. :)
+jcims This is my first stab at refrigeration and it was loads of fun, there are a bunch of projects I want to mess around with now. Like can liquid nitrogen be generated using only regular refrigeration equipment found in household appliances.
The pro cesor lmao
Interesting? This is my 2nd visit 👍😎
500 times more heat conductivity than COPPER ???? Is that correct ??? Thanks
Are you sure that its ok to be spraying trifluoroethane in your breathing atmosphere?
How did you figure out how much water to put in the Heat Pipe initially? Did you heat the pipe up to 100C and then close the valve?
Also what is the glass tube device at the end of the video? Was that some type of prototype?
+dano3829 I figured out the volume of water by trial and error, it only needs to be about 1% filled over all. I heated the pipe until steam was leaving the valve and then closed it because that is the only way to know that all the air had been flushed from the pipe.
The glass tube is a another heat pipe that shows what's going on inside but it doesn't work very well. The glass walls don't transfer heat to the air around it so I wasn't able to use it for the main demonstration.
I saw some people using small amounts of acetone instead of water , does it make a difference in terms of efficiency?
I think it changes the lowest operating temperature but probably is less efficient because water takes more energy to transition from a liquid to a gas.
damn. Your video is awesome. You should post it somewhere in Reddit.
+Victor Gaíva If you can think of a sub that would like it go ahead and post, I put a short write-up in /r/physics a few weeks ago and got a positive response.
Glad you liked it!
I think a great demonstration of a heat pipe's heat conductivity would be to submerge the low end in a pot of boiling water; The water should stop boiling, and might take a long time to begin boiling again... if it boils again.
+Nevin Williams Hmm, with enough cooling at the top I think you're right, I'd need to set up some fins and a blower to dump heat to the room.
I guess this is the same as how a reflux column heats up on an alcohol still since there's pretty much mostly vapour in the column with a few drops condensing on the sides. As soon as my still heats up at the bottom, it's a matter of a minute before the top of the reflux cloumn is the same temperature.
+Jim Griffiths I was thinking the same thing as I was filming this video. As the steam makes its way up the tube it can get surprisingly hot in a short period of time, even when it is at atmospheric pressure.
Hello, we are french students currently working on a project that involves heat pipes. We find your video very interesting, especially the whole "homemade" aspect of it as we would love to recreate a heat pipe of our own ! Could you give us more information on how you built yours ? Thank you :)
Hi! If you send me an email I can give you more details.
@@NickMoore can you send me more info in pawel AT cohabitat DOT net ?
I've asked this question before with mixed responses: Does the orientation of the heat pipe matter ? i.e. if the heated end was elevated higher than the ambient end would it still work this well ? my hypothesis is yes orientation matters, but i cbf building a heat pipe to test. .... also if orientation does matter would putting a wicking material inside the pipe along with the fluid help? Also does a wicking material help at all? so many questions !!
I don't know a lot about heat pipes, but the modern real ones used for cooling processors rely on capillary action, as Nick mentioned, so I would say no, it does not matter. But it does for much older ones as well as for the DIY ones. Nowadays CPU and GPU thermal management is starting to utilize vapor chambers. The same science is at work, but a vapor chamber is essentially a 2D version of a heat pipe. The disadvantage is that orientation does matter, I think.
+Power Max you got it. If there is a wick material then the orientation doesn't matter, my heat pipe has no wick and so relies on gravity to return the condensate to the hot end. I never heard of vapor chambers while I was googling about pipes, there was a flat/square example on the wiki page but I'm not sure if it's the same thing. Thanks for the tip!
Nick Moore With a wick it acts like a wire, but for heat. Without a wick, it acts as a thermal diode. Add a section of a thermal insulator, such as glass or plastic, then the diode will have much better characteristics.
It wouldn't be hard to design something that tilts when the water boils in a tube and shifts the center of gravity. If this was mechanically coupled to another heat pipe such that it moved one end into, or out of a source of heat, it would work like an electric relay, but for heat.
This could be used for an art installation.
+hamjudo It sounds like a drinking bird toy. It works by moving a fluid from one end to the other by evaporative cooling. Once the top end has enough condensed fluid it tips and resets itself.
yes, it was very interesting, Thank you! Sub:)
cool
+Pro DI Water systems Thanks!
Nice, like the valve at the top. I am just curious, but if there is
a trap at the top to collect all of the water, how long would it take for all the water to move to the top in a similar test?
There is nothing extra inside the pipe just the water and steam. Generally as soon as the steam makes it to the top of the pipe is condenses and starts to drip back to the bottom.
If you overload the pipe with too much heat all of the water will boil and the pressure inside the pipe will rise very quickly. I don't know how quickly it could be done but doing so can cause the pipe to burst.
I am interested in moving the water to the top and keeping
it there. I know the fundamentals of a heat pipe, as shown in this
very good demonstration of yours.
I am working on my off the wall invention of moving water to higher
level and having a hard time finding the the rate of fluid move from
one end to the other, in heat pipes?
And i was wondering if
you could give ball park guess on the flow rates. this something i have
been wondering about for a long time, and if it is worth it to making
this invention?
Any information will be greatly appreciated.
As far as I know the steam can move at or near the speed of sound but you could never use a heat pipe (or something like it) to move water efficiently. The energy required to boil it is significantly more than the energy needed to just lift it by conventional means.
Thank you for your help.
desalination?
Can this work for low temp (~0°C) and low dT as well? (Eg by using a different work fluid?)
Yes, there are heat pipes designed to work at very low temperatures, I'm not sure about low dT though. I can't think of why it wouldn't work.
It depends on the fluid used and the pressure inside the pipe.
Will u please tell me and show the experimental setup, how to creat a vacuum in a tube(copper or glass) and fill its half volume with water and seal it without leak
The tubes are only filled about 1% of its length with water. To make the vacuum and seal it I first add the water then heat the bottom of the tube until there is steam leaving the top of valve. Then I close the valve and let the tube cool, as it cools the water will condense back into a liquid and pull its own vacuum.
@@NickMoore tq sir...
How many percent % of water should there be in relation to the size of the pipe ?
I only had about 1 or 2% fill but you can use more. Too little water and the tube will saturate and not be able to move any more heat.
Very good demonstration.
How many ml of water did you use inside?
And how many ml of Volume is the tube that you use for heat pipe?
I'm not actually sure the volume of the pipe but it was only about 1% filled with water. It takes very little water to make it work.
OK! Back a 3rd time. I wonder if senility is setting in or I just find it dang iNtErEsTiNg :O)
I wonder how big I can make these, and how thick of wall I would need. I'd like to try making about a dozen of these, six inches or so in diameter, maybe 15 feet long, and bury them 10 feet in the ground and put the top ends in a heat exchanger. See what kind of heat we can dump from a heat pump into the ground with these suckers.
Unless you use a wick material inside theses tubes only move heat upwards. The pipe only has to hold up to 14psi of vacuum so anything that is made to hold water or compressed air is strong enough.
อาจารย์กิตติพล ขาวงาม
So tell us what percentage water is perfect saves me from doing your work thanks
I have no idea. I had about 1% fill but that was to make it react quicker while limiting the amount of power that can be transmitted.
Does the heat pipe need sintered or grooved inside to conduct efficiently ??? Thanks
A 'real' heat pipe you would find in a CPU cooler has a sintered powder coating on the inside but mine do not. The sintered powder acts as a wick to return liquid water to the hot end of the tube when it is not mounted vertically.
@@NickMoore Can something else be used instead of the sintered bronze Nick and does the pipe have to be somewhat vertical to work correctly ???
I think a very fine mesh of copper wires or some kind of heat resistant fabric would also work but not as well as the powder. With a really good wick I think a heatpipe can even work upside down.
@@NickMoore Thank you Nick, now I am ready to make something happen this coming winter. As they say, plan ahead and never be late. Peace vf.
AVE sent me. I can't believe I didn't know about your channel.
Glad you like it, these heatpipes were one of my favorites just due to their simplicity. Any one can build one and they are fun just as a "WTF" shop decoration.
Thanks for this! I never imagined that they were so straightforward..for some reason I imagined that it was necessary to use more volatile substances with lower boiling points. I guess that would help broaden the operating temperature range, but if up around water's boiling point at that pressure, it's all good.
Do you have any recommendations for determining ideal liquid volume relative to pipe volume and working pressure?
+icarus901 Water is one of the best working liquids as long as you are between 0 and 100c, it takes more energy to boil than any other liquid. The only time you need to get into exotic working fluids is if you are into extreme temperatures (hot or cold), some of the hottest heat pipes even use metals as their working fluid!
ah, so essentially pick a convenient substance with the largest energy delta in the vaporization direction in its phase change diagram? (for target temp+pressure)
Pretty much, the more energy you can soak up at the hot end the cooler you can keep it.
how do I attach the heat pipe to my bong?
If you had a taller water column to make better thermal contact with the hot vapours you could probably immerse 5 or 6 heat pipes in the water to dissipate the heat. Though your bong might look like the Voyager space probes.
Do it with ammonia!
Hello what is the ratio of liquid to internal volume of the pipe?
Less than 5%, more water can move more heat but I think it will operate at a higher temperature.
This is perfect for heating a house up north you can suck the heat out of the Earth's core easy with this why spend money and energy to heat a house if you can just make heat wells and if you had a internal water pump to pump the water from underground to above ground you can use this to cool your house too I bet the water pump will use less energy than a normal air conditioner that uses a air compressor
A really reliable heat engine can be made easy too a simple pelton wheel can fill up with water on one side and spin a generator the more heat you suck out the ground the more electrical power you get so heat your driveway never have a icy driveway again
Boop
Too bad, people don't have much interest in useful stuffs like this...
This is not a heat pipe ... this is just a thermosiphon .