The BYU Solar Cooker/Cooler

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BYU Solar Cooker/Cooler, The

The Project Gutenberg EBook of The BYU Solar Cooker/Cooler
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Title: The BYU Solar Cooker/Cooler
Author: Steven E. Jones
Release Date: June 2004 [EBook #5889] [Yes, we are more than one year ahead of schedule] [This file was first posted on September 16, 2002] [Edition 11 first posted August 2, 2003]
Edition: 11
Language: English
Character set encoding: ASCII

*** START OF THE PROJECT GUTENBERG EBOOK, THE BYU SOLAR COOKER/COOLER ***
This eBook was produced by Aaron Canon, Steve Herber, and Jack Eden.
Note: The .zip version of this eBook includes 11 images.
How to Make and Use The BYU Solar Cooker/Cooler
by Steven E. Jones, Professor of Physics at Brigham Young University (BYU), with Colter Paulson, Jason Chesley, Jacob Fugal, Derek Hullinger, Jamie Winterton, Jeannette Lawler, and Seth, David, Nathan, and Danelle Jones.
Copyright (c) 2002 by Steven E. Jones
Original web site with this article: http://solarcooking.org/funnel.htm
[Image: 01.jpg -- Photo description this image shows a cardboard box being used to support a silvery funnel, roughly 3 feet high. The funnel is placed within the box so that the sides of the box hold the funnel upright. Sitting within the base of the funnel is a black jar inside a clear plastic bag. The plastic bag is inflated like a balloon to seal an insulating air pocket around the jar.]

Contents
I. Introduction II. How it works III. How to Build Your Own Solar Funnel Cooker - What You will Need for the Funnel Cooker - Construction Steps IV. Final Steps V. After Cooking VI. Tests - Tests in Utah - Tests in Bolivia VII. Water and Milk Pasteurization VIII. Safety IX. Cooking with the Solar Funnel Cooker X. How to Use the Solar Funnel as a Refrigerator/Cooler XI. Conclusion: Why We Need Solar Cookers XII. Answers to commonly-asked questions XIII. Recipe for wheatpaste XIV. Updates - Rabbit-wire base - Reduced angle - Save-heat cooker - Funnel-cooling during the day - Hot-and-cold running water - Conclusion

I. Introduction
A few years ago, I woke up to the fact that half of the world's peoples must burn wood or dried dung in order to cook their food. It came as quite a shock to me, especially as I learned of the illnesses caused by breathing smoke day in and day out, and the environmental impacts of deforestation -not to mention the time spent by people (mostly women) gathering sticks and dung to cook their food. And yet, many of these billions of people live near the equator, where sunshine is abundant and free.
As a University Professor of Physics with a background in energy usage, I set out to develop a means of cooking food and sterilizing water using the free energy of the sun. First, I looked at existing methods.
The parabolic cooker involves a reflective dish that concentrates sunlight to a point where the food is cooked. This approach is very dangerous since the sun's energy is focused to a point which is very hot, but which cannot be seen. (BYU students and I built one which will set paper on fire in about 3 seconds!) I learned that an altruistic group had offered reflecting parabolas to the people living at the Altiplano in Bolivia. But more than once the parabolas had been stored next to a shed -- and the passing sun set the sheds on fire! The people did not want these dangerous, expensive devices, even though the Altiplano region has been stripped of fuel wood.
The box cooker: Basically an insulated box with a glass or plastic lid, often with a reflecting lid to reflect sunlight into the box. Light enters through the top glass (or plastic), to slowly heat up the box. Problems: energy enters only through the top, while heat is escaping through all the other sides, which have a tendency to draw heat away from the food. When the box is opened to put food