I've been told that the lid on say a "Global Oven" needs to be left open. I have never tried a solar oven with a lid. so I'm just wondering what other experiences have been. My experiments have all been done clear nights with ambient high of 45 degrees to a low of 38 and have been able to produce a consistent disc of ice in a low flat pan. Canning jars haven't frozen solid, deep pans haven't either. I have used my own deisgned solar cone collector only. I do have a large parabolic but haven't played with it to see its results. Just looking and learning.
Our inability to change everything should not stop us from changing what we can.
Yeah, I've done this using a good cooler with a removable top, wrapped on all sides with reflective mylar. I've heard it called a space refrigerator. The basic idea is that, since everything in your environment radiates infrared according to it's current temp, you are always receiving some heat exchange from your environment, even at 40 degrees. However, if you can limit the amount of ambient heat that your cooler receives, while also maximizing the amount of radiant heat it can emit, you can push down the apparent temps inside the cooler. It must be a clear, cool night, with a northern exposure to the sky. There cannot be any amount of moon in the view of sky from the perspective of your cooler. It won't make much ice, and I've never got it to make any above about 40 degrees. More of a science experiment than a reliable ice production method.
omg, i have been trying to find out more abt solar oven because i thought it would be great to cook without carbon emissions.
but this is so cool too, dual purposes for any new solar oven i get
never realise i can use a solar oven to actually make ice!
For folks wanting to cook without CO2-emissions. Perhaps this is something ? http://www.solsuffit.be/en/index.html Friends of mine wanting to do something about cleancutting african forests for cooking fuel came up with the idea.
As to cooling without electricity - i thought those designs were mostly based on black body fysics ~ ie your 'fridge' should be painted black on the inside - when you open it on clear sky nights, you can cool it down to freezing.
I once read that this technique was used by the babylonions to make ice. Don't know if that's correct. I certainly don't know of archeologicals digs confirming this. It was described to me as a dugin earthware vessel coated with black bitumen. In the daytime it should be closed.