Interesting cooling concept.

[sour_grapes]

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? )

 

[terrymck]

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.

 

[richmke]

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.

 

[dcbrown73]

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?

 

[stickman]

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.

 

[mennyg19]

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

 

[richmke]

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.

 

[JohnT]

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.

 

[Floandgary]

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 :>

 

[jswordy]

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

 

[dcbrown73]

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