Cooling with bottles

Originally posted by @joe-shmo
I think you are confusing some concepts here, so bear with me ( I'm not a Physicist, but this should basically be correct).

Heat is not being extracted from the flow, it is generated from the flow.

The flow entering has all its energy tied up in its pressure, velocity, elevation, and temperature (as far a classical mechaincs is concerned). Now let ...[text shortened]... cannot be trasfered or gained from beyond the universe - which is just a theory at this point).

I'm not a physicist either. I have noticed you centering your attention on what causes heat, without adressing what I said about a very slight compression throwing off heat that gets swept out in the backwash. I'm not sure if this is because you don't understand what I've been saying, or because you think it's crap and not worthy of a response.

I have a basic understanding of how air conditioners work, so I'm intrigued by the idea of heat transfer in an exceedingly simple design.

Originally posted by @lemon-lime
I'm not a physicist either. I have noticed you centering your attention on what causes heat, without adressing what I said about a very slight compression throwing off heat that gets swept out in the backwash. I'm not sure if this is because you don't understand what I've been saying, or because you think it's crap and not worthy of a response.

I have ...[text shortened]... onditioners work, so I'm intrigued by the idea of heat transfer in an exceedingly simple design.

An adiabatic compression causes the flow to heat up. As you point out there would be a very slight compression ( I mean miniscule) on the order of 0.01 psi or less. That compression would cause the flow to warm, not cool. I wasn't intentionally ignoring your response.

Originally posted by @joe-shmo
An adiabatic compression causes the flow to heat up. As you point out there would be a very slight compression ( I mean miniscule) on the order of 0.01 psi or less. That compression would cause the flow to warm, not cool. I wasn't intentionally ignoring your response.

What about going in the opposite direction, from small diameter to larger?

Originally posted by @sonhouse
What about going in the opposite direction, from small diameter to larger?

That would create a temperature difference in the proper direction (cooler), but again the effect would be miniscule, and heat will be generated as the air passes through the bottle. so it would enter the diffuser slighlt warmed, and expand back to its just over its initial temperature as a consequence of the second law. So those effects essentially offset at the energy scale provided by a summer breeze, and you lose the effect of forced convection. Which is in my opinion the only effect.

Originally posted by @joe-shmo
An adiabatic compression causes the flow to heat up. As you point out there would be a very slight compression ( I mean miniscule) on the order of 0.01 psi or less. That compression would cause the flow to warm, not cool. I wasn't intentionally ignoring your response.

Right. But for there to be any cooling effect most of that now (ever so slightly) warmer flow would need to be channeled back out and into the outside air. So (theoretically) slightly warmer air in the backwash exits the large opening as ever so slightly cooler air enters a house through the smaller hole.

But (and this is a really big but. But I mean, really... who doesn't like big buts?) I believe claims...
Okay, I should start over...

However, I believe claims of how much indoor cooling can be achieved are greatly exaggerated. I've seen enough info-commercials to know how this works, but the most important difference here is no one appears to be selling anything... at least not yet. If this is a come on to generate interest for the purpose of marketing and selling these things later on, it would undoubtedly rank as one of the lamest marketing schemes in recent history... because word would have already gotten out about how little the cooling effect actually is.

Aside from all that, I do think this idea has merit and possible future potential. With a little tweaking of the design, and possibly adding an outside (or maybe inside?) fan to control air flow, it might work well enough as an inexpensive way to keep indoor temps somewhat lower than the outside air.

The bottles create a vortex.

https://en.wikipedia.org/wiki/Vortex_tube

Originally posted by @apathist
The bottles create a vortex.

https://en.wikipedia.org/wiki/Vortex_tube

These use highly compressed air. The same effect would happen if you simply passed the compressed air through a throttling valve. This is not going to happen ( to any noticeable extent ) using the energy contained in a warm summer breeze.

Also there still is a fundamental difference. The work to compress the air in this votex tube was provided by a external source (turbomacinery).

The work that ever so slightly compresses the air in a summer breeze as it hits the bottle was provided by the air that hits the bottle!

Do you see how this is a fundamentally different setup?

Originally posted by @lemon-lime
Right. But for there to be any cooling effect most of that now (ever so slightly) warmer flow would need to be channeled back out and into the outside air. So (theoretically) slightly warmer air in the backwash exits the large opening as ever so slightly cooler air enters a house through the smaller hole.

But (and this is a really big but. But I mean, ...[text shortened]... work well enough as an inexpensive way to keep indoor temps somewhat lower than the outside air.

There is no actual cooing effect on the flow itself. The temperature of the flow does not go down. The effect is comparable to a fan. The fan actually warms the air, but the added forced convection and perspiration aid in evaporative cooling if the surrounding air is not fully saturated.

If the people had electricity and a fan, they would just be better off using the fan by itself.

Originally posted by @joe-shmo
There is no actual cooing effect on the flow itself. The temperature of the flow does not go down. The effect is comparable to a fan. The fan actually warms the air, but the added forced convection and perspiration aid in evaporative cooling if the surrounding air is not fully saturated.

If the people had electricity and a fan, they would just be better off using the fan by itself.

Without the electricity?

Originally posted by @joe-shmo
These use highly compressed air. The same effect would happen if you simply passed the compressed air through a throttling valve. This is not going to happen ( to any noticeable extent ) using the energy contained in a warm summer breeze.

Also there still is a fundamental difference. The work to compress the air in this votex tube was provided by a ex ...[text shortened]... ded by the air that hits the bottle!

Do you see how this is a fundamentally different setup?[/b]

Throttling valves reduce flow. I don't see how they would tend to separate the warmer molecules from the cooler molecules. Maybe it does, though.

I suggest that the warm summer breeze is enough to create a tendency for the warmer molecules to be backwashed out of the larger opening of the bottles while the cooler molecules end up flowing through the narrow opening of the bottles.

(The vortex tube described in the link provides much greater temperature differences than the simple bottle structure from the op. I do not see that the principle is different.)

The warmer molecules are faster, and tend to gather towards the outside boundary of the gathering tube and then become backwash, leaving the cooler molecules to actually squirt through the narrow section and into the hut.

Larger cone-shaped gathering areas and narrower squirt-tubes should improve the temperature difference, at the expense of air-flow. Huts need airflow.

Originally posted by @joe-shmo
There is no actual cooing effect on the flow itself. The temperature of the flow does not go down. The effect is comparable to a fan. The fan actually warms the air, but the added forced convection and perspiration aid in evaporative cooling if the surrounding air is not fully saturated....

I agree there is no cooling of the air itself, but disagree that the effect is comparable to a fan. What this device does is separate the warmer air molecules from the cooler air molecules.

Air temperature is an average, as you know. Individual air molecules could run the gamut of possible temperatures.

Originally posted by @sonhouse
What about going in the opposite direction, from small diameter to larger?

What would the small diameter collect? Just status quo.

If I were on the wrong page, tw would bitch-slap me. That hasn't happened, so welcome to the explanation of third-world cheap air conditioning.