The BYU Solar Cooker/Cooler | Page 7

bag away from children and away from nose and mouth to avoid any possibility of suffocation.

IX. Cooking with the Solar Funnel Cooker
What do you cook in a crock pot or moderate-temperature oven? The same foods will cook about the same in the Solar Funnel Cooker --without burning. The charts below give approximate summer cooking times.
The solar cooker works best when the UV index is 7 or higher. (Sun high overhead, few clouds.)
Cooking times are approximate. Increase cooking times for partly- cloudy days, sun not overhead (e.g., wintertime) or for more than about 3 cups of food in the cooking jar.
Stirring is not necessary for most foods. Food generally will not burn in the solar cooker.
VEGETABLES (Potatoes, carrots, squash, beets, asparagus, etc.) Preparation: No need to add water if fresh. Cut into slices or "logs" to ensure uniform cooking. Corn will cook fine with or without the cob. Cooking Time: About 1.5 hours
CEREALS AND GRAINS (Rice, wheat, barley, oats, millet, etc.) Preparation: Mix 2 parts water to every 1 part grain. Amount may vary according to individual taste. Let soak for a few hours for faster cooking. To ensure uniform cooking, shake jar after 50 minutes. CAUTION: Jar will be hot. Use gloves or cooking pads. Cooking Time: 1.5-2 hours
PASTA AND DEHYDRATED SOUPS Preparation: First heat water to near boiling (50-70 minutes). Then add the pasta or soup mix. Stir or shake, and cook 15 additional minutes. Cooking Time: 65-85 minutes
BEANS Preparation: Let tough or dry beans soak overnight. Place in cooking jar with water. Cooking Time: 2-3 hours
EGGS Preparation: No need to add water. Note: If cooked too long, egg whites may darken, but taste remains the same. Cooking Time: 1-1.5 hours, depending on desired yolk firmness.
MEATS (Chicken, beef, and fish) Preparation: No need to add water. Longer cooking makes the meat more tender. Cooking Time: Chicken: 1.5 hours cut up or 2.5 hours whole; Beef: 1.5 hours cut up or 2.5-3 hours for larger cuts; Fish: 1-1.5 hours
BAKING Preparation: Times vary based on amount of dough. Cooking Times: Breads: 1-1.5 hours; Biscuits: 1-1.5 hours; Cookies: 1 hour
ROASTED NUTS (Peanuts, almonds, pumpkin seed, etc.) Preparation: Place in jar. A little vegetable oil may be added if desired. Cooking Time: About 1.5 hours
MRE's AND PREPACKAGED FOODS Preparation: For foods in dark containers, simply place the Container in the cooking bag in place of the black cooking jar. Cooking Times: Cooking time varies with the amount of food and darkness of package.

X. How to Use the Solar Funnel as a Refrigerator/Cooler
A university student (Jamie Winterton) and I were the first to demonstrate that the BYU Solar Funnel Cooker can be used--at night --as a refrigerator. Here is how this is done.
The Solar Funnel Cooker is set-up just as you would during sun-light hours, with two exceptions:
1. The funnel is directed at the dark night sky. It should not "see" any buildings or even trees. (The thermal radiation from walls, trees, or even clouds will diminish the cooling effect.).
2. It helps to place 2 (two) bags around the jar instead of just one, with air spaces between the bags and between the inner bag and the jar. HDPE and ordinary polyethylene bags work well, since polyethylene is nearly transparent to infrared radiation, allowing it to escape into the "heat sink" of the dark sky.
During the day, the sun's rays are reflected onto the cooking vessel which becomes hot quickly. At night, heat from the vessel is radiated outward, towards empty space, which is very cold indeed (a "heat sink").
As a result, the cooking vessel now becomes a small refrigerator. We routinely achieve cooling of about 29 degrees Fahrenheit (10 degrees Celsius) below ambient air temperature using this remarkably simple scheme.
In September 1999, we placed two funnels out in the evening, with double-bagged jars inside. One jar was on a block of wood and the other was suspended in the funnel using fishing line. The temperature that evening (in Provo, Utah) was 78 degrees Fahrenheit. Using a Radio Shack indoor/outdoor thermometer, a BYU student (Colter Paulson) measured the temperature inside the funnel and outside in the open air. He found that the temperature of the air inside the funnel dropped quickly by about 15 degrees, as its heat was radiated upwards in the clear sky. That night, the minimum outdoor air temperature measured was 47.5 degrees--but the water in both jars had ICE. I invite others to try this, and please let me know if you get ice at 55 or even 60 degrees outside air temperature (minimum at night). A black PVC container may work even better than a black-painted jar, since PVC is a good infrared radiator--these matters are still being studied.
I would like to see the "Funnel Refrigerator" tried in desert climates, especially where freezing temperatures are rarely reached. It should