Introduction: How to Make a Box Oven Solar Thermal Cooker
Many developing countries around the world use wood as their main source of energy. To be specific, over 3 billion people use wood as a resource to cook for their families. However, wood smoke in their house not only destroys the environment because of over forestation, but it causes major health issues as well. Indoor air pollution kills over 2 million people prematurely through different diseases like Pneumonia, Chronic Obstructive Pulmonary Disease (COPD), and lung cancer. Additionally, instead of children going to school, they would spend the day searching for wood for their parents to cook meals.
As a class, we were taught that the sun is an extremely beneficial resource because the amount of heat it generates onto Earth every day. We studied different cases to determine what type of solar thermal cooker would be best for each client, then we decided what type of solar thermal cooker we wanted to cook with various restrictions (budget, time, resources, etc.) For this project, a majority of the materials we used are either free or really cheap. Not only will the sunlight be able to be converted into solar heat, it will also be able to concentrate it on a single point.
Project made by: Melanie Jane P, Melissa J, and Dremiah A. Part of Period 3 Physics class of Kipp King Collegiate.
Step 1: Step One: Get Your Materials!
The following materials we used were:
-1 cardboard box
-Aluminion foil & tape
-3 styrofoam boards
-1 piece of glass
Tools used were:
-tamperature measuring gun
Step 2: Step 2: Assembling the "cooker"
To assemble the "cooker," where the food will be cooking, take away the cover of the Styrofoam box and put the glass on top. Make sure that the glass is completely covering the top of the Styrofoam box and that the Styrofoam box will fit in the cardboard box. The reason why it's best to use a Styrofoam box is because the material will prevent the heat from escaping. The purpose of the glass is to trap the sun in the cooker as it reflects off of the aluminum. The glass acts as an enforcement to encapsulate the heat, and thoroughly cook the food inside the insulated box.
Step 3: Step Three: Preparing the Inside of the Box
Next, put the cooker inside the middle of the box, where it will attract the most light. Around the cooker, add crumpled paper to act as insulators when grabbing the light. There's not a specific number, just enough to cover the bottom. I strongly suggest you use scratch paper so new paper is not wasted.
Step 4: Step Four: Preparing the Reflectors
Begin by cutting off the flaps of the carboard. Then, cut the 4 styrofoam boards into different sized pieces (ours was the inside of the box, you can see the styrofoam more clearly in Step 3). Styrofoam boards were effective because they were light and easily flexible if we wanted to change the form. In this case, we didn't, but you can if it's more effective. For each styrofoam board, cover one side with aluminum foil or tape. The aluminum foil will act as the reflectors and point light towards the cooker. Make sure that the aluminum is new and clean for the best results because it will capture and focus the most sun.
Step 5: Step 5: Add the Pipe As a Stand (if Needed)
For our reflectors, we were testing around different places the reflectors can be put to capture the most light. One side needed a stand because it was not staying slanted. So, we used a pipe (that was free) to act as a stand in order to keep the reflector slanted to get more light.
Step 6: Step 6: Attaching the Reflectors
After moving the reflectors around and aiming the sun at the cooker, start by marking areas for the flaps to go. We attached two reflectors on the box and one reflector on the two reflectors the was attached. Depending which areas got you the most sunlight, cut flaps about 1' 1/2" to 2' 1/2" deep so the reflector will stay put. This was more effective than adding other materials because we wanted the cooker to be as light as possible, so we simply just cut flaps.
Step 7: Step 7: Cut the Front and Add More Aluminum Foil
In order to capture more light from the sun to the cooker, using the razor knife, cut a section of the front out so the sun can hit the cooker. After, add aluminum foil on the other side so more sun can be reflected onto the cooker. To attach the aluminum foil, use adhesive spray and be careful of having any glue in contact with your skin. The open access will also ensure that all the sunlight is being used as much as possible. This will allow for direct sunlight to hit the Styrofoam insulated box.
Step 8: Step 8: Test It Out!
Test out the solar thermal cooker by adding food inside the cooker (We decided on taquitos). Use the temperature measuring gun to see how hot it is getting. Ours was around 90-110 degrees, but it was still effective because the air inside the cooker was hot, while the gun was measuring the styrofoam box which does not conduct heat easily, allowing it to escape.