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

[infringer]

I wonder if you couldn't couple this system with say a solar heater on one end to gain more power at peak sun time or even a Fresnal lens maybe... Well I suppose each project is always a step at a time but your results are rather interesting.

[ResinRat2]

I thought about focusing the sunlight too, but I was debating whether it would have a helpful effect up to a point, and then it might be counter-productive and heat up the inner sand layer. This might actually heat the center aluminum oxide mass. Who knows, it might actually help; but I would say it is something to try.

I am going to purchase more aluminum oxide so the center pot is filled to the top and I will have a nice 10-15 pounds of thermal mass to work with. This should help with maintaining a heat differential.

Most people would probably dismiss this concept, but I find it interesting.

[Pirate88179]

Aluminum oxide has a very good (for this application) thermal conductivity number. (Meaning low conductivity)  But, there are many, many types of Al203.  We used to purchase a number of different mixtures and purity in the ceramics business.  Purities of 99.7% vary greatly from purities of 99.8%, and 97% and 96% as well as 95%.  Each, like steel, has their own set of physical properties and vary greatly from each other.  Usually, depending on the manufacturer, (we purchased most of ours from Coors) the remaining ingredients in the Al203 is usually glass.  That is why, for metalization purposes, we used 95% because the glass allowed the metal to bond with the Al203.

So, I would make sure you know the content of the aluminum oxide you are using as just a little bit of difference make a huge change in physical properties.  And, if your supplier tells you it is 100% Al203, do not believe them as Coors 99.8% cost us (20 years ago) $100.00/ft of 1/4" rod.  This is very specialized stuff.

I don't know if this helps or not but, I was tossing it out there.

I can post the specs on this stuff if I can dig them out of my library.

Bill

[electrospark]

Why not taking a propane fridge and replace the propane flame by some kind of solar oven?
this could maybe work!

Regards.

electrospark