Carboard Box Oven

[dryson]

http://www.cnn.com/2009/TECH/04/09/sola ... pstoryview

Does anyone know how this works exactly? How much thickness is needed for the tin foil and paint, does the tin foil have to be smooth and not crinkled? Also does the thickness of each carboard box matter in how much heat is generated? Does the distance from the interior box' exterior edge to the exterior box' interior edge matter in creating the heat effective zone? Can steaks be cooked inside of it, or are there limited food types that can be cooked?

 

[rogerinnh]

As pointed out in the article itself this is not at all a new or novel idea, which raises the question of why his "invention" won first prize in that contest. Obviously neither the "inventor" nor the contest judges did much research about it.

You can find dozens of solar oven plans here:

http://solarcooking.org/plans/

 

[centsworth_II]

As pointed out in the article itself this is not at all a new or novel idea, which raises the question of why his "invention" won first prize in that contest.

I guess the winner had the best in-field outreach program, which is key to actually affecting global warming with any invention.

As far as why the oven works, it's because of the greenhouse effect. The clear top allows the sun's energy to enter and heat the inside, but does not allow the infrared heat from the hot inside to escape. The same reason the inside of a car can go well over 120 degrees Fahrenheit even if it's only 80 degrees outside. Also, this is the same greenhouse effect implicated in global warming. In that case, greenhouse gases, like CO2, act as the glass, allowing the sun's energy in, but stopping the infrared heat from the surface from escaping, thus heating up the Earth like a big solar oven.

Funny... using an invention using the greenhouse effect to combat global warming caused by a runaway greenhouse effect.

 

[andrew_t1000]

This idea works a lot better when you DON'T USE A CARDBOARD BOX!
I built one from bits of an old electric stove, I cut the top off, put the collector on top, double glazed the window on top, left the original glass door on the front, then made up a frame attached to an old office chair base so I could rotate it.
The reflective collector on top is a type of "non imaging lens", I read an article in Scientific American ages ago about the principle.
If you insulate the oven, with say, rock wool, it works better.
To get an oven you can actually roast in, the top window needs to be double glazed.
If you build one out of decent materials, insulate it well, you will be amazed at how hot it will get.
Just watch out you don't burn your pizza or nachos or whatever!
On a very hot day here in South Australia, I managed to melt aluminium!