# Interesting cooling concept.



## dcbrown73 (Jun 9, 2016)

I had read about this before, but here is a video that shows how it works.

If you keep your wine in a room that is mostly cool, but could benefit from a bit more cooling (especially in warmer months) maybe this is a homemade device you can make without adding another A/C unit. 

Though since your house is sealed, you can probably create some type of funnel out of a heavy duty plastic garbage bag duct tapped around a tornado fan leading to the back of the board to force air through the bottle tops.

My house is at 72F. If it's true that you can drop the temperature by up to 5 degrees Celsius. Theoretically, I could drop my wine storage closet closer to 64-65F!

[ame]https://www.youtube.com/watch?v=jPuh8IFbIzQ[/ame]


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## Boatboy24 (Jun 9, 2016)

Fascinating!


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## Mismost (Jun 9, 2016)

In those villages...I think if they put a layer of thatch on top of the tin roof it would also help by blocking the sun's radiation from the roof....shading it in effect. Vines planted in front west walls would also help....grape vines of course!

A friend in West Texas has one of those concrete cattle troughs and a wind mill in the pasture...they built a simple brush arbor beside it on the north side...big piece of burlap is hanging up next to the trough and down into the water...south wind blows through the burlap...you're sitting in shade and it's quite a bit cooler with the breeze cooled by that burlap wicking water up from the trough. Nice spot to eat lunch after working cows all morning....if you can stand the flies!


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## BernardSmith (Jun 9, 2016)

What a great idea... but I wonder if it works only when the air is moving at significant velocity (a need for the fan or for there to be an open window and the fixture set up to block it


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## lilvixen (Jun 9, 2016)

That's really neat!


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## vacuumpumpman (Jun 10, 2016)

very simple idea !

I would like to look into it a bit more - a 20 degree F drop is alot


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## JohnT (Jun 10, 2016)

Interesting, but wouldn't it only work in a strong breeze that would cool you off anyway??


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## dcbrown73 (Jun 10, 2016)

vacuumpumpman said:


> very simple idea !
> 
> I would like to look into it a bit more - a 20 degree F drop is alot



I believe it's closer to 9 degree Fahrenheit. 1 degree Celsius is equal to 1.8 degrees Fahrenheit. (1.8 * 5 = 9)

Which is why I said my 72F wine storage closet, could be brought down to 65F (or 63F if it actually can cool 5 degrees Celsius)

I generally cool my reds to 65F in my counter top wine cooler. I wouldn't have to do that anymore and only keep my whites in it at 55F.


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## dcbrown73 (Jun 10, 2016)

JohnT said:


> Interesting, but wouldn't it only work in a strong breeze that would cool you off anyway??



You would need a breeze strong enough to force air through it. 

That's why I said I would get a tornado fan and a heavy duty garbage bag to create a funnel from the fan to the back of the board with the 2 liter bottles in it.

I don't buy 2 liter bottles, but I go through 16.9 ounce water bottles at work. Maybe I will try with those.


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## bkisel (Jun 10, 2016)

Wow! What a cool idea!






In Vietnam we were able to cool our squad tents if able to get a parachute and hang it a foot or so below the canvas top. I've no idea, in degrees, how much cooler it made the tent but I can tell you that it was definitely noticeable compared to squad tents not having a parachute.


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## JohnT (Jun 10, 2016)

It is worth an experiment. It is hard to believe that such a little amount of compression can make such a difference. I was never really big on thermodynamics, but I am sure that someone on this sight can do the math.........


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## Boatboy24 (Jun 10, 2016)

bkisel said:


> Wow! What a cool idea!



I see what you did there!


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## vacuumpumpman (Jun 10, 2016)

dcbrown73 said:


> I believe it's closer to 9 degree Fahrenheit. 1 degree Celsius is equal to 1.8 degrees Fahrenheit. (1.8 * 5 = 9)
> 
> Which is why I said my 72F wine storage closet, could be brought down to 65F (or 63F if it actually can cool 5 degrees Celsius)
> 
> I generally cool my reds to 65F in my counter top wine cooler. I wouldn't have to do that anymore and only keep my whites in it at 55F.



I went off the 2 temperature readings in the photo -


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## stickman (Jun 10, 2016)

I have to call BS on this one. In general, as a gas is compressed the temperature of the gas increases. Any cooling caused by the gas dropping in pressure as it flows through the nozzle would be offset by the temperature increase during compression. The air speed may be increased, so it may feel a bit cooler, but the total air flow would be reduced. In sweltering dry heat it may be better than nothing, but I don't think you'll be seeing these things cooling a wine room any time soon.


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## ibglowin (Jun 10, 2016)

Where is the resident WMT Physicist @sour_grapes when we need him...........


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## terrymck (Jun 10, 2016)

It's been over 50 years since I sat in a classroom but I would say that it's not the compression of the air but the expansion after it leave the nozzle that causes the cooling effect. One of those dead Europeans discovered it. Boyle, Pascal someone like that.


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## dcbrown73 (Jun 10, 2016)

terrymck said:


> It's been over 50 years since I sat in a classroom but I would say that it's not the compression of the air but the expansion after it leave the nozzle that causes the cooling effect. One of those dead Europeans discovered it. Boyle, Pascal someone like that.



Thanks Terrymck.

From Wikipedia:
_
*Joule–Thomson effect*
The effect is named after James Prescott Joule and William Thomson, 1st Baron Kelvin, who discovered it in 1852.
_​
LINK => Why does air cool as it expands?

EDIT: The interesting thing here is, in this case the compression of the air entering into the bottle theoretically should have caused the air to heat up, then cool back down as it left the nozzle. (returning to the same air pressure) How does it end up cooler is the question.


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## stickman (Jun 10, 2016)

Yes, there is cooling when a gas expands, but there is heating when it is compressed. In the picture, air flows into the large end of the bottle and is compressed as it moves into the neck, as it flows out of the neck and into the room it expands, so the temperature of the air is first heated by the compression and then cooled by the expansion; therefore, there is no net change in the air temperature.


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## richmke (Jun 11, 2016)

It is the way an air-conditioner works. The gas is compressed, and heats up. If something can take away the heat, then when it expands, it will be cooler than before.

I don't see how the gas can give up enough heat to the nozzle to make a difference.


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## Mismost (Jun 11, 2016)

stickman said:


> I have to call BS on this one. In general, as a gas is compressed the temperature of the gas increases. Any cooling caused by the gas dropping in pressure as it flows through the nozzle would be offset by the temperature increase during compression. The air speed may be increased, so it may feel a bit cooler, but the total air flow would be reduced. In sweltering dry heat it may be better than nothing, but I don't think you'll be seeing these things cooling a wine room any time soon.



I tend to agree. The thing I noticed in the video was the nice new hole cut into the side of the solid tin wall...any air movement is bound to help inside a tin box!


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## sour_grapes (Jun 11, 2016)

ibglowin said:


> Where is the resident WMT Physicist @sour_grapes when we need him...........



I call BS. 

Rich ( @richmke ) has more or less nailed it. If the air is compressed at the bottleneck, it is heated. If it does not shed any of that heat, it will be the same temperature after expansion as it was beforehand. 

I agree with Rich that I cannot see plastic soda bottles absorbing significant amounts of heat. And, let's say they did... where would that heat go? The necks would heat up; maybe a little of the heat would be passed to the outside air, but most would be passed back to the fast-moving airstream inside the bottle. 

Furthermore, the amount of temperature rise expected from such a small compression is negligible. 

Bottom line: guys and gals, this video was produced by _an advertising agency_, that was _trying to win a humanitarian award_ fer cryin' out loud....


(Hmmm, why didn't they arrange the bottles in a hexagonal pattern to get more of them in the same area?  )


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## terrymck (Jun 13, 2016)

I still think that this device has merit. If you have ever seen an air operated water pump running on a humid day you would have noticed that the exhaust to the pump was frosted up. The compressed air runs the pump and as it exits, expands and cools down. Certainly enough to freeze the moisture in the air. The air is acting like a refrigerant, not very efficient but never the less a refrigerant. Any gas will do this.


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## richmke (Jun 13, 2016)

terrymck said:


> The compressed air runs the pump and as it exits, expands and cools down.



Yes, but the HOT highly compressed air is able to loose a lot of heat to the metal pump. Thus, when it expands, it can cool down a lot.

The bottles have minimal air compression, and minimal transfer of heat to the plastic bottle.

It is like comparing a Harley to a Big Wheel.


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## dcbrown73 (Jun 13, 2016)

Maybe I will run a test on it in my wine closet once I collect enough water bottles and construct the device.

The device being, a board with bottles, a tornado fan with a heavy duty trash bag connected to the fan and the bottle board to direct air to the bottles.

I will test the following:

Standard Temp
Temp with just a fan blowing
Temp with a fan forcing air through the bottles.

Record the temperatures and respond with the results. It may be a bit before I can do this, but once I do. I will post the results.

EDIT: The list formatting feature does not work on this website. Why is that?


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## stickman (Jun 13, 2016)

In this case, there is not enough pressure to work with, even with a fan, you might see a few inches water column pressure difference between the bottle inlet and outlet. The Joule Thomson cooling effect is very small under these low differential pressure conditions, it will not even compensate for the heat generated by the fan motor.


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## mennyg19 (Jun 21, 2016)

Im gonna pipe in over here with a theory of my own. 
I don't think there is any major air compression going on in the video as they show, as there is nothing forcing the air into compression as most air conditioners and refrigerators have. Rather, its just a small hole going into a big room. So whatever air comes in, must expand in the big room, and therefore cools it. 
I would bet that before this experiment the villagers had windows and doors open, now they are told to only have these small holes open, so whatever air moves into the hut will automatically cool upon entering. And if you are sitting right in front of this cooler, it will be a much cooler breeze than a regular one.
Make any sense? No compression, only expansion


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## richmke (Jun 21, 2016)

mennyg19 said:


> Make any sense? No compression, only expansion



In order to have expansion, there must be a pressure differential. The air pressure on each side of the wall is the same, hence no expansion.

The funneling of the air can cause a slight compression.


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## JohnT (Jun 21, 2016)

I would think that this would only restrict the air flow into the hut. In the heat of summer, I would think that any cooling effect (and I doubt there is any) would not be enough to compensate for the fact that you have turned the hut into a large solar oven.


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## Floandgary (Jun 21, 2016)

http://www.lowes.com/pd/Honeywell-1...Portable-Evaporative-Cooler-150-CFM/999901005 
http://www.lowes.com/pd/Frigidaire-5-000-BTU-150-sq-ft-115-Volt-Window-Air-Conditioner/50342322
Plug-n-play..... KISS :>


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## jswordy (Jun 21, 2016)

Link says "This video is private." Nuff said, I reckon....


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## dcbrown73 (Jun 21, 2016)

A/C removes moisture from the air which I would think would be a negative affect to an aging wine's cork.


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