# Wind-powered non-electric refrigerator



## ryanthomas (Dec 10, 2009)

This is something I've been reading and thinking about for a while:
http://mb-soft.com/public3/selfsuff.html#refrig

Basically the idea is to compress air slightly with a crude wind turbine, then use the ground to cool the compressed air. You then release the compressed air to atmospheric pressure and it cools...simple physics, air heats when it is compressed and cools when the pressure is released. It's called air cycle refrigeration and it is used for airliner air conditioning, obviously not with a ground source heat sink. But this guy's website looks like it's all theory and he hasn't actually done this. I get the basic concept, but my physics understanding isn't up to par. Anyone seen something like this in practice? Or have any ideas of whether it will work or not?


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## MichaelK! (Oct 22, 2010)

These kinds of cooling systems have been mentioned before and they've not taken off for several important real-world reasons. Soil by it's nature is insulative and heat transfer is very slow. It is even slower in dry soil because the intrapped air is even more insulative. Once a certain about of heat is added to the system it essentually stops because heat won't conduct itself in and out fast enough.

A second serious problem I've read about is the buildup of mold in the piping. Condensation in the piping breeds mold, which you will be subsequently be breathing and smelling.

Finally, there's the issue of pipe placement, which requires the pipe to be placed 3-4' down in the ground for it to be effective. I've had to dig down that far to reach freeze protected pipe, it it Aint fun!

On a more fundamental level Ryan, I think it is sharp of you to notice that a lot of these "plans" are just plans, and are not built and functioning systems in operation. Sometimes the reality of the theory hitting the real-world just isn't pretty!


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## ryanthomas (Dec 10, 2009)

Using the soil as a heat sink was one of the weaknesses I saw with the idea. It could work, just as geothermal systems do. But water would work much better, something along the lines of a cold stream. And I've heard of the mold problems with earth tubes where you just blow air through them. I guess you're right that it could be a problem in this scenario as well. Probably not an insurmountable obstacle, but something to consider. One positive about this idea is the fact that the air is compressed slightly, which if I understand correctly, causes the moisture to condense at a higher temp, so maybe it would be easier to drain it away.

I've been reading about a lot of these crazy ideas for a while and I'm finally getting to a point where I have the time and resources to do some more in-depth experiments. Thanks for your helpful feedback!


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## byexample (Aug 28, 2009)

Pretty cool... thanks for the link. Have not seen this method of refrigeration before. I too would like to see a practical example...


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## wind power (Sep 29, 2010)

Once again I dont want to be a buzz killer here, but has anyone used this and what are the results?
I quickly combed the web site and it appeas to have the same tired argumet of how a VAWT is so much better than a HAWT wind turbine, and whoever this person is backs up the claim by saying and showing some videos and pictures of HWATS burning up or self-destructing, but likewise fails to mention how many VWATS are being used commercially VS HWATS ( practically no VWATS of course) then this guys goes on with some more mathamatical forumals as how VAWAT is again so much better...but time after time this has been proven false.

It appears whoever this fellow is has very little practical hands experience...but instead is a dreamer.

I simply dont see wind farms made from those VWAT toys.

Cavet Emptor

However if anyone is serious about building one, A double acting Bellows like blacksmiths used for hundreds of years might be easier to build than trying to get a "quazi-seal" in a metal drum. The bellows might prove out the concept then you can spend a bit more time on the drum.


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## wy_white_wolf (Oct 14, 2004)

wind power said:


> .....However if anyone is serious about building one, A double acting Bellows like blacksmiths used for hundreds of years might be easier to build than trying to get a "quazi-seal" in a metal drum. The bellows might prove out the concept then you can spend a bit more time on the drum.


Seems all you really need to is compress a little air. One could easily take a screwdrive compressor and mount some blades on the shaft.

A whole lot less work than trying to figure out the VAWT thing. Not to mention what are you going to do on the windless dog days of summer.


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## ryanthomas (Dec 10, 2009)

The guy who wrote this freely admits that vertical axis wind turbines are very crude and much less efficient than horizontal axis wind turbines. But he justifies using it because it is so much cheaper that you can afford the lower efficiency. The wind turbine really isn't what interests me anyway. I like the concept of air cycle refrigeration with a ground/water source heat sink. It could be powered by pretty much any source of energy that can be converted to rotary motion. I like the bellows suggestion, though. That seems like a great improvement. The screw compressor is also a good idea. As for windless days, you can use a large compressed air reservoir, maybe a 500 gallon propane tank. One of my ideas I've been thinking about is using a much higher pressure than the 4-6 PSI he talks about, then you can store a lot more air in a given space. For the higher pressure, wind probably wouldn't work very well because of starting torque limitations. What I have in mind is a compressor belt driven off an engine to fill a tank once a week or so, while also charging batteries for other uses. Just a vague idea, but I'm trying to work out problems with the whole concept before I throw too much time into it. Thanks for the helpful feedback and suggestions.


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## Harry Chickpea (Dec 19, 2008)

Air isn't a particularly good working fluid for refrigeration or heating. However, for certain applications, it can be effective. Do a search on vortex cooling or air vortex cooler. You should find a little shape that twists an airflow so that the heat is extracted at one end, and cold comes out the other. It takes a lot of pressure and is noisy.

Another fascinating method of cooling is the steam eductor. Trains were cooled this way at one time. Again, not efficient, but a nice concept.


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## ryanthomas (Dec 10, 2009)

True, air is not a great fluid for cooling or all refrigerators would use it, but you can't beat the price. And the non-hazardous aspect makes it good for experimenting by non-professionals, since a leak in the system won't hurt anything (except efficiency). I could also use an open system rather than a closed loop to make it slightly less complicated, again with a large loss in efficiency. Thanks for the vortex cooling suggestion. I've heard of that but never actually looked into how it works. I'll check it out.

I emailed the author of the link I posted and he responded with quite a bit of information about systems he has actually installed. He says there hasn't been any problem with the soil getting too warm because he uses "fairly large diameter pipes" and it is actually not very much heat pumped into the soil. Also he says he's never had condensation in the pipes, because compressing the air raises the temperature enough that it never gets down to the dew point in the pipes. But he admits it could be a problem in some climates, and you could easily add in a slope to a drain.

I think the "fairly large diameter pipes" might be expensive overkill, but he says he tries to over-design everything for around a "factor of two." I would probably use something like 4-6" PVC for the underground section, or if I have enough water to dump the heat into, a coil of soft copper tubing going through the water should work, and I could possibly even use the heat that way.


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## MichaelK! (Oct 22, 2010)

You know Ryan, I really have to agree with Wind Power on this one. I really get tired of these "wonder systems" that are "supposed" to revolutionize solar power, or air conditioning, or hydrogen production. Pie in the sky ideas that look good on paper (or the monitor) that just don't work in the real world.

The first question I have to ask is "where is the working model". Where are the pictures of the "real" system. Where is the data that shows how many watts are produced, how many miles there are to the gallon, how many degrees cooler the room is. I get so very bored with "it feels like it's working" or "my car feels like it has more power"! My advice is to stop talking about these ideas and start testing them. Your attitude will change real quick!

But hey, maybe a wind powered fuel cell hydrogen generator will work better with polarizing magnets!


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## ryanthomas (Dec 10, 2009)

I partially agree with you about "wonder systems." I have studied plenty of alternative energy ideas, and lots of them are junk. But I keep an open mind. The reason I posted here was because I knew people would be critical of the idea and I was looking for any reason not to waste my time on the concept. So far I have received some helpful suggestions, but no one has come close to convincing me that this isn't feasible. So I will probably do some experimentation with it. I should be able to test it out for a hundred bucks. If it fails miserably, I'm not out much money. If it shows promise I can go from there.

This guy who came up with this is a dreamer, no doubt about that. But that doesn't automatically disqualify all of his ideas. I've read some of his other ideas and some seem stupid and worthless while some seem valuable. He claims to be a nuclear physicist, maybe he's lying. But as far as I can tell, he knows what he's talking about, and I am a reasonably intelligent person. He claims there are over 9,000 of these refrigeration systems in use. Maybe he's lying. I don't care. I'm the type of person who is willing to test something before dismissing it, unless it is obviously junk science, like over-unity devices. No one has told me any solid reason this cannot work. So I'll see for myself, unless I find a fatal flaw with it first. Thanks to everyone who provided helpful feedback. I'm still open to more if anyone has any.


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## wind power (Sep 29, 2010)

Hi Ryan, 

Indeed that&#8217;s what it takes to be innovative, that is to dream.
However my first impression of the web site, after a very brief scan of it, was there was a lot of theoretical stuff and it was very short on trial error experimentation.

One of the best homebrew cooling systems short of buying an air conditioner was a fellow I saw on YouTube who simply bought some 1/4 copper tubing and loosely uncoiled it and then he used some zip ties to attach it to the guard of a cheap-o box fan, from one end of the copper tubing, he attached a small aquarium pump with a short length of plastic hose, simply by shoving it over the copper tubing, on the other end he did the same thing with the plastic tubing.
He then put the aquarium pump into a cooler which had slurry of ice and water, and then the return line also went back into the cooler too.
He cut on the pump and the box fan ...it worked just like a swamp chiller.

Old timers use to do the same thing, but different application... they would soak some hay or straw and let a fan blow across it.

But back to your topic, the probability of it working mechanically is very high, after all old Aeromotor windmills were used for pumping water. But to get the necessary mechanical linkage and torque required to push everything will probably be a blade swept area of no less than about 15 feet.
Your biggest hurdles are:

No winds of 10mph or greater you are going to be panting and sweating like a wart hog on the Serengeti Plain after a long chase by a Cheetah
There is very little available power in winds less than 5-6 miles an hour.

Lastly how deep is this thing going to be???
It has to draw incoming air from somewhere...so that&#8217;s telling me it&#8217;s coming from above....thus does it have enough time to cool...after it makes its run through the double acting pump and through the tunnel and end user?
It would have to be a very long run....anyone who has used compressed air around a mechanical shop will tell you it comes out a bit cooler but not enough to make you go "AAAAHHHHH" on a hot summer day....so I'm thinking this piping will have to be deep


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## ryanthomas (Dec 10, 2009)

wind power said:


> One of the best homebrew cooling systems short of buying an air conditioner was a fellow I saw on YouTube who simply bought some 1/4 copper tubing and loosely uncoiled it and then he used some zip ties to attach it to the guard of a cheap-o box fan, from one end of the copper tubing, he attached a small aquarium pump with a short length of plastic hose, simply by shoving it over the copper tubing, on the other end he did the same thing with the plastic tubing.
> He then put the aquarium pump into a cooler which had slurry of ice and water, and then the return line also went back into the cooler too.
> He cut on the pump and the box fan ...it worked just like a swamp chiller.
> 
> Old timers use to do the same thing, but different application... they would soak some hay or straw and let a fan blow across it.


I have actually used both of those ideas for cooling things in the past and they're great for some applications. They're not the same, though. The second one is like a swamp chiller, which uses evaporation to absorb heat out of the air. The first one uses simple conduction to transfer the heat to the water. But neither of those principles will work for the application I'm talking about. Basically, I want to use this concept to freeze food and keep it frozen. Maybe it will work, maybe not.

I admit I don't know much about wind power, so I will defer to the expertise of others if I decide to try to use wind to compress the air. At this stage, my focus is on the air-cycle side of the equation. The pipes in a ground heat sink would be 5-10 feet deep, and probably over 100 feet long. I don't see any reason going deeper would be beneficial. But my idea is to possibly use water as a heat sink instead, in which case I would have to do some trial and error testing. Air could even be the heat sink, just not a very good one.

I'm not sure everyone who is commenting understands the basic concept behind this, which is air-cycle refrigeration. It is simple physics based on the ideal gas law, air being nearly an ideal gas. I'm not really qualified to explain it, but maybe I will try if I can get a better grasp on it myself.


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## wind power (Sep 29, 2010)

It sounds like a plan, keep us posted on any progress


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