Solar cooling with 2 clay pots ! Very cheap genius idea !

[ResinRat2]

I just found it interesting. I could use just water to produce the heat differential. Since the Seebeck effect that laci mentioned can produce a current from a heat differential, I just figured that something like this, with the localized heat differential, could produce an electrical current for FREE. You know, like power produced from a natural, renewable resource. LOL!  Namely, the Sun's heat.

HEY! That's called overunity.

That's why I was interested. I just have not heard of anyone putting these two technologies together to produce a constant electrical output.

Just some crazy idea that crossed my already overloaded mind.

[Koen1]

I was just surprised that evaporative cooling was such a new area for so many.

Hans, I guess many people have grown so accustomed to refrigerators that they
don't really know the old technology anymore...
Your example of hanging sheets in front of the windows with the bottom sticking in a
bucket of water is one I hadn't really heard before. I suspect it doesn't work as well
in very humid areas (like the Townsville region for example) ? Nice application though.
I was told stories of similar "bush fridges" when I lived in South Africa, by old people
who still remembered the days they didn't have any electricity nor electrical cooling.
A few described a cooler box that had cloth wrapped around it which was either regularly
watered by hand, or was hung in a vessel containing water to soak it up. The box itself
would be either fine wire mesh to allow air to move through the box, or it would be
a metal box. One old lady told me how they used a slightly different mechanism
where water from a container on top of the box was allowed to flow down the fine
wire mesh box and collected at the bottom, and part of the water would evaporate
during the downflow of course, cooling the box and contents.
Works like a charm, if you have enough water to waste on evaporation.

[ResinRat2]

Well I have some results from my two pot experiment.

I took four readings over the last 36 hours.

The first was about two hours after the unit was built, then I took another 12 and 24 hours after starting. This test as run in my basement which has a pretty constant temperature and because I have a dehumidifier going constantly, the humidity level should be pretty well controlled and constant.


Elapsed Time (hrs:min)         Air Temp(F)                     Inner Pot Temp(F)                     Differential(F)
    2:00                                             63                                     57                                        6
   12:00                                            63                                     57                                        6
   24:00                                            65                                     57                                        8
   36:00                                            65                                     57                                        8

So It appeared to have stabilized at 57 F.

I then transferred the unit outside into the sunlight. It sat in the sun for an hour and I took the following readings.

Elapsed Time (hrs:min)      Air Temp(F)                     Inner Pot Temp(F)                    Differential(F)   
  1:00                                         75                                     60                                        15
  2:00                                         75                                     61                                        14
Which is where it stands now. I want to let it sit in the sun for several hours to allow the unit to equilibrate. I was actually hoping the temperature would drop, but so far this did not happen.

Just out of curiosity, does anyone know what type of heat differential is required to run a Stirling engine?
I'll see if I can find the information.

Thanks for your interest.

[ResinRat2]

Here's a link:
http://www.howstuffworks.com/framed.htm?parent=stirling-engine.htm&url=http://www.stirlingengine.com/

This unit runs on a temperature difference of only 7.2 degrees F.

Could this have possibilites?

Hmmmm... I'll have to think about it for a bit to see if I could dream up a configuration that could utilize this temperature difference with a small stirling engine.

Thanks for your interest.

[ResinRat2]

Actually, reading on how the Stirling engine works, all I would have to do is place the base of the engine on the moist rag that covers over the top of the unit. This temperature differential should then start the engine operating.

Could it be that simple?

I wonder what type of differential a really LARGE pair of pots would create.

Does anyone out there own a small Stirling engine and would be interested in trying this?

Thanks for your interest.