Eco Cooler - zero electricity air cooler

[kamturbo]

This showed up on my feed today and seems pretty interesting. Anyone tried this before? Once I can find enough bottles I'll try to build one for my side barn door opening and see if I can make a version that is stowable.

Eco Cooler

 

[rvpopeye]

Impressive :idea: !
I expect lots of vandwellers will be experimenting with these.

 

[jimindenver]

More likely it is the decompression of the humidity in the air that is causing any cooling effect.

 

[highdesertranger]

I caught that too, when you compress air the air gets hotter. now when you release that hot air it does cool the air. they should have explained this better. a double roof, spaced a couple of feet apart would make a world a difference. highdesertranger

 

[jimindenver]

All it would take would be a small scale version of four bottles and a temp gun to see if the output out of the holes is cooler.

 

[sushidog]

It is a zero sum game. Let's say you could compress 90 degree air a little and it rose 1 degree. When the compressed air returned to the pressure it was before it was compressed it would lose the degree it rose and now be 90 degrees again. It can't get colder than it started unless it passed through some cooling device with fins or water flowing through it (like an air/water intercooler for a supercharger.) So if there is any observed cooling effect for the device, this does not explain it.

However if you increase the velocity of the air, it increased the evaporative effect of air blowing across skin moist with perspiration (even insensible perspiration) therefore it is the cooling effect from the evaporation of this moisture on your skin that you feel - the same as a very weak fan would produce. The actual temperature inside the hut would actually increase from the reduced airflow as the device blocks some window area. Putting large windows on all sides of the hut would probably work better, as would using window shutters as an air scoop to draw in more air. Better yet have the entire wall hinged where it can be opened in the direction of the wind, using the entire wall to funnel in the breeze, would probably work better. Putting insulation under the hut's roof would work the best. Adding moisture to the air like a swamp cooler does, would work well in a dry environment like a desert, but would have little effect in areas of high humidity, like a jungle. Homes in the hanging gardens of Babylon were said to be cooled by evaporative cooling and cool river water passing through pipes in the walls of this arid place.

Chip

 

[cherterr]

I didn't think much of the results.. OR.. um.. You know.. when you blow out air from your lungs w/mouth completely open; it's coming from deep within and is WARM (from diaphragm).. when you just purse your lips and blow.. well.. it's just what's in your mouth and not so hot.

How do I know? lol.. I once ran out of envelopes and only had the pre-addressed stickers to the wrong address. I would use my HOT breath to slowly get them off w/o tearing envelope.
I'm jus' sayin'. lol

 

[ArtW]

I can blow through my pursed lips from the diaphragm just fine, so can anyone.
the 'cooling' effect is from evaporation / expansion
How exactly do you folks think AC works?
a gas is compressed into a liquid, the liquid is introduced into an 'evaporator' where it returns to a gaseous state, and that evaporation cools the gas in the evaporator'
then the hot air from the passenger area of the car is blown across a the fins of the evaporator, where the heat from the air is transferred to the cold gas, which then becomes a hot gas, that goes to the compressor and condenser to be returned to a liquid state and shed the heat it absorbed to the atmosphere, and the cycle repeats
anyone who's ever used a propane torch for any length of time has experienced the top of the bottle getting cold even as the flame remains lit
Heck, sometimes the gas freezes inside the bottle and the torch quits working
Propane was in fact the first refrigerant, IIRC

 

[MrNoodly]

If anything, it's that the captured and compressed air comes out of the "nozzles" faster, creating a concentrated breeze, which aids in the evaporation of sweat, which cools a body. So first you need some breeze. Secondly, you need humidity low enough that sweat will actually evaporate.

 

[ArtW]

Agreed, the actual air will be no cooler, it was not compressed into a liquid, so will not actually cool the air

 

[ZoNiE]

If anything, it's that the captured and compressed air comes out of the "nozzles" faster, creating a concentrated breeze, which aids in the evaporation of sweat, which cools a body. So first you need some breeze. Secondly, you need humidity low enough that sweat will actually evaporate.

I think this actually makes the most sense. There is not enough energy in the natural breeze to cause a true compression expansion event. smaller orifice translates to more directed airflow...

 

[Lafnbug]

The 3 laws of Thermodynamics:

1. You can't get something for nothing. (You Can't Win)
2. You Can't Break Even
3. You Lose

 

[DannyB1954]

A little while ago I wrote about this and even did an experiment. https://vanlivingforum.com/Thread-Free-airconditioning
I think how it works is the same principle used in an intercooler for a diesel engine. You compress the air which raises the temperature, you then cool that air with another source, and then when the air is decompressed it expands and cools.

How this one does it I think is when the wind compresses the air into the inside of the bottle it slightly raises the temperature. This heat is transferred to the outside of the plastic bottle. Now the wind is also blowing on that outside surface of the bottle and picking up the heat and carrying it away from the building or vehicle. As the air flows out the end of the bottle the pressure drops and it absorbs heat, (cools).

I tried to make a type of intercooler with a fan and did get some results, (see the link I provided, page 2 post #19). I don't think the results were worth the energy used, (maybe with modifications it would be. I got a 2 degree temperature drop which proves the theory correct). This device would be most useful where there were constant strong trade winds from one direction. I do believe that it does work and is not just a Youtube farce.

 

[DannyB1954]

The 3 laws of Thermodynamics:

1. You can't get something for nothing. (You Can't Win)
2. You Can't Break Even
3. You Lose

The laws of thermodynamics are that heat is energy. Heat always flows from the warmer to the cooler. The rate of flow is proportional to the difference in temperature. The greater the difference in temperature, the quicker the flow. Concentrating a volume of any gas into a smaller area raises the temperature. (It contains the same amount of heat, but being in a smaller area the temperature goes up). 

When you run an air compressor the line going to the tank gets hot. While the air sits in the tank it cools,, (through heat transferring through the walls of the tank). When you release the air as in a blow gun, the air expands and absorbs heat, (feels cool). A room at 70 degrees has a lot more heat in it than a blowtorch. It is just not concentrated. Try heating a zero degree room with a blowtorch. Not so easy. the torch does not have the volume of heat necessary. 
Liquid nitrogen is produced by pumping regular air at very high pressures into a smaller area. The heat is removed and then the pressure is released. The escaping air gets so cold that it changes the gasses into a liquid.

In the case of this device, they are using the energy of the wind, (not something for nothing), to compress the air, and also cool the container that the compressed air is in. it won't be a large drop in temperature because the air is not being compressed to a great degree, but there will be a drop.