Currently there are many ways to build practical objects and utensils taking advantage of objects that today have little value. This is the case of the materials that we are going to use to build a solar oven in a simple and practical way, where if it is well done and on a hot day, temperatures of 150ºC can be reached. It all depends on how we build it. If this is your first time and you are inexperienced (like us)… go ahead!
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HOW TO BUILD A SOLAR OVEN IN A SIMPLE WAY
If you live in a region where you have many hours of sunshine, now is the time to build a solar oven . Its construction is very simple and it is a perfect tool for rural getaways or in areas where electricity does not reach. Let’s build it!
TYPES OF SOLAR OVENS
There are different types of solar ovens divided into 2 families:
BOX SOLAR OVEN
A thermally insulated box, in which it captures solar radiation and allows the inside of the box to be heated. As the materials used are low conduction, there are no risks of fire, burns or temperatures so high that they can burn food.
CONCENTRATING SOLAR OVEN
The technique with this solar oven consists of concentrating the solar radiation from a surface in a single point. For example, it is usually a parabolic antenna that acts as a reflector. Right at the point where radiation is concentrated, the pot or food to be cooked is arranged, where high temperatures are reached and where food can be fried or liquids boiled. In the concentration oven, when reaching high temperatures, it is necessary to control the heating process and protect against possible burns.
Within these 2 families there are many types and variables, and everything depends on the ingenuity in the manufacture , the materials that are available and the imagination . In our case, we are going to teach you how to make one out of cardboard boxes. It is not as durable as if we used other materials but it is very practical. But you, as long as you have the idea of how to do it, you can build it with wood or other elements.
STEP-BY-STEP CONSTRUCTION OF A SOLAR OVEN
STEP 1: SEARCH FOR MATERIALS TO USE
- Two boxes (one larger than the other so that the small one can be inserted into the large one).
- Pair of scissors
- Glue or glue
- Foil
- Insulating material (crumpled paper, polystyrene balls, wool, cotton, toilet paper, newspapers, etc.)
- Clear, strong plastic or glass
STEP 2: THE STRUCTURE OF CARDBOARD BOXES
As we have already said, you can use wood , which is more resistant, but requires more carpentry work. With either of the two ways, the structure of the solar oven is created . We measure the perimeter of the small box, which will be the hole that with the scissors we have to create in the large box. We will make the opening at the base of the large box, that is, with the flaps resting on the ground, and we will introduce the small box leaving the flaps up (which will later be the union of the small box with the large one, you will see ).
STEP 3: LINE THE SOLAR OVEN BOXES WITH ALUMINUM FOIL
As we have the boxes right now we will have to line both the small box inside and the flaps with aluminum foil . In the case of the outer box, we will also line the interior walls, including the bottom (where we have made the opening, the remaining edge). You can do it with glue, avoiding as much as possible wrinkles or breaks. In which case we can patch it up by placing a new strip of aluminum foil.
STEP 4: FILL THE GAP BETWEEN THE BOXES
As you can see, there has been a gap between the small and the large box, which we will have to fill with the insulating material. It can be any of those that we have put on the list, or if you think another that can also serve as a perfect insulator. The step will be to cover the entire gap. It is not necessary to compress the insulating material, because the free air space also acts as an insulator. The flaps of the large box, which form the base of the solar oven, are closed, glued and sealed, and the flaps of the small box are glued to the base of the large box, so we already have both boxes joined and with insulating material between them.
STEP 5: THE SOLAR OVEN LID
As we have the solar oven right now, the lid would be missing to cover the box. We need either glass or plastic . In the latter case we need a transparent and highly resistant plastic, because we already know that a plastic in the sun is easily deformed, in which case we will have to replace it with another.
To make the lid of the solar oven we need a cardboard rectangle, of the same nature as the boxes. We will make an opening the size of the glass (it must be at least the same size as the small box) and we will join it to the cardboard using adhesive tape. After measuring the size of the large box, on the cardboard strip the edges are created as a cover, as you can see in the photo below.
This lid can be opened and closed without problem (as if it were a shoe box), to introduce or extract the food before or after being heated. The next step will be to test to see if it works. Surely yes!
OTHER WAYS TO MAKE A SOLAR OVEN
This last example is a very simple way to build a single r oven in a short time . However, you can put your knowledge into practice by building other shapes. We have tried to explain how a box solar oven is made, but you can also try to make a concentrating solar oven , which in the future we will explain how.