Do any of you use them or have had much sucess with them in the past? As my final project for physics, my super environmentalist friend and I are making a solar cooker. Only catch is that just for a basic 85 grade, we need to get 50g of water up to 70C. To get a 100 we have to get it up to 100C which is our goal, but we don't know what the most effective way is and how to go about it with minimal expenses (under $15). Anyone have any ideas? I was thinking rigging up some mirrors to direct more sunlight into a aluminum foil bowl. But yeah.. if any of you have any ideas or past experience getting a solar cooker to boiling point, I'd really appreciate it.
mirrors would be bad. they trap the light in, they dont bounce it back. a mirror is basically a black surface covered by a piece of glass, so all your heat is going to be trapped in the mirror. if you use foil, it has to have no wrinkles in it. the best option (as milar is expensive) is a Flat White paint on a completely flat surface for the bottoms and sides of your box. then you need a piece of glass at about a 60 degree angle on top, and youre going to want to face it south and slightly to the east (if youre in north georgia). as far as the sides of your box, i wouldnt mess around too much with trying to angle or curve them bowl shaped, as this will bounce the light and heat back out of the top. you want the heat staying at the bottom of your box, as heat will rise. im good at this. edit: you actually want the glass a little under 60 degrees maybe 40, and then the back wall behind it to angle a little more than 60 degrees now that i think about it.
The ones I have seen in books are essentially a cardboard box lined with foil and a reflective lid made from plywood lined with foil.The top has a clear glass to trap the heat to trap the heat like a greenhouse.The carboard box should sit in another one with insulation in between.An aluninium bowl to hold the water would not be the go as it would reflect the heat.The best thing is container with a lid made from oven proof glass, (translucent or transparent) or black iron.
Thanks you guys! We were supposed to test tomorrow but it's supposed to be rainy, so Monday is our new test day. I don't know what the finished product is going to look like because my partner was finishing it up, but I'll take pictures Monday. I had a little glass incident. I borrowed some glass from a picture frame and while I was attaching it to the box, I got a phone call and made the mistake of laying it on the ground and ended up stepping on it and shattering it. So we might end up using seran wrap just to trap the heat in as a substitute (a weak one at that) if my partner can't find anything. We're happy though because we spent absolutely no money in making this. \m/ Yay for random household items...
