The Solar Kitchen Embudo Type

Since to make and to use the Solar Kitchen


I could construct the parabolic kitchen devised by Steven E. Jones Profesor de Física in “Brigham Young University?, it works very well. The planes you can see them in this same page.

Before constructing this interesting solar kitchen, that in fact is a solar furnace, we see some types of solar kitchens and their use:

The PARABOLIC KITCHEN is based on a disc that reflects and concentrates the light of the sun in a point where the food is cooked. This method is quite dangerous since the energy of the sun is concentrated in a very hot point but that it cannot be seen and therefore it can cause to burns and fires.

The BOX KITCHEN (or Kerr-School): It is basically a box isolated with a cover of crystal or plastic, normally with a reflector that reflects light to the interior of the box. The light enters by the crystal (or plastic), pair to warm up the box slowly. It faces the following problems: The energy only enters by the part superior while this one escapes by the cosrados ones, which lies down to leave the food separated from the heat. When the box is opened to put or to remove the food, it leaves from the heat escapes. In addition, the kitchens of this type lie down to being more complicated to do than a kitchen of funnel.

The kitchen designed by Steven Jones is safe, cheap and effective. It is a mixture between the parabolic kitchen and the one of box. It has a species of great and deep funnel and incorporates the best characteristics of the parabolic kitchen and the one of box.

The reflector can be done of paper of aluminum stuck to a cardboard, or also a piece of aluminum lamina can be used for the presses, soon bends to form a funnel.

As It works

The reflector has the form of a covered giant funnel with aluminum paper. (The instructions of assembly occur more down) This funnel is as the parabolic kitchen, excepting that the light of the sun is concentrated in a line (and not in a point) at heart of the funnel. You can put the hand in the part inferior of the funnel and feel the heat, but it will not burn to you.

Next we painted a container of black color by the part of outside, to accumulate the heat, and we placed it in the part inferior of the funnel. Or we can use a black container with cover. The black objects are warmed up easily. But not sufficiently to cook… we needed then, some way to warm up the same being prevented that the air cools it. Is used ttransparente plastic stock market a cheap surrounding the container. Plastic stock-market, available in stores as “stock market for vegetables?, it replaces the face and expensive box with crystal cover of the box kitchens. You can use the plastic bags without handles totally I am transparent, these allow to pass much sunlight (the dark bags do not let pass the light.)

Normal polythene melts immediately, reason why we must put some insulator, as a wood block, to help to maintain the heat (any other insulator can work: cord, a log, or even palitos of wood)

The funnel kitchen can even work in the days of winter. By all means, the kitchen funnel works far better outside the days of winter (when index UV is more of 7 or). The majority of the solar kitchens would not work more in winter in the zones to the north (or those that are more to the south, from 35º)

If it is had a kitchen under pressure would be wonderful. But also a tin with hermetic cover can be used under pressure - a pot! - the time each is reduced to half 10º C that we increased. It is necessary to paint of black mate by the outer part with painting in spray, and will work of wonder. The food cooks faster than in a normal container. Of all ways, you can put any other black container in stock-market if you want. But not one with cover to spiral, the pressure could burst it!

Since to make your own kitchen funnel.

That you will need:

  1. A flat cardboard piece, of 60 cm by 120 cm (the length must twice be the width, and when greater better)
  2. Normal and current aluminum paper.
  3. White tail or to mix (as the carpicola) and water to dissolve it to 50%. Also a brush or broaches to apply it (or a piece of fabric or paper). Also paste can be used..
  4. Something to hold the embraced funnel (wide, prudent sticky tape,…).
  5. Of kitchen set of dishes I recommend a hermetic container to them.
  6. The jar (receiving of glass) must be painted of black by the outside. I have seen that spray black cheap mate works well, is necessary to request painting in spray for cars. A small “window? in the container scratches to be able to see the interior if this one is of glass.
  7. A wood block that does of insulator. The approximate measures are of 10cm of length x 10cm of width x 5cm of stop. A square wood piece for of insulator perfectly.
  8. A stock market to surround the jar and the block of wood, to make the greenhouse effect. Ideas:
  • Bags to bake, those of normal size are perfect: I am transparent and they do not melt.
  • A stock market of those almost transparent marked as HDPE (Polythene of HD, High Density PolyEthylene). The idea is that the plastic is the quite resistant thing as so that does not melt in contact with the container. Also we can place a painted black container within a crystal salad bowl; cover it with a cover. It tries to find something that tightens

Instructions step by step

Short half circle of the cardboard

Short half circle of the cardboard of the part inferior as one is above. When the funnel has formed, this it becomes a whole circle and it must sufficiently be great as so that your jar of baking fits. By this rule of three, for a container of 18 cm approx of diameter, the radius of means circle must be of 18 cm. (that is to say 36 cm of diameter).

It forms the funnel

In order to form the funnel, you must join the side To with side B, as it is seen in the image. The aluminum paper must go Within the funnel. Beam this slowly, giving to the cardboard funnel form using a hand to make dog ears that leave from means circle. It sees perfecting the funnel until causing that the sides To and B they are joined and the means circle form a complete circle. The aluminum paper will go Within the funnel. It opens the funnel and leaves extended it, with the INNER face upwards. We happen then to the following step.

It sticks the paper of aluminum to the cardboard

It applies to glue or tail in the part superior (inner) of the cardboard, then, quickly pon the aluminum paper on the glued part. Assure to you that the part most shining of the aluminum paper looks at outside, since this one will be the reflecting part of the funnel. You can put the right glue for an aluminum layer since therefore the glue is not dried. Also you can cover with strips with about 2 cm and average. It leaves as smooth aluminum paper as you can, but some small wrinkles do not do anything. (If you do not even have cardboard you can make a hole in the ground with form of funnel and to cover it with aluminum paper to have a funnel kitchen fixes and to use it at noon)

Together the face To with the expensive B maintaining the together funnel. 

The way easiest to do this is making 3 holes in the side To and B to the same height (to see the image). Then it passes a pin of paper through each hole and holds opening the two legs. Or also we can use a screw butterfly (that is a screw with a nut with form of metal butterfly) to hold sides both (To and B).

Creative and so you have by hand. For example, you do two holes with a separation of 1 cm and average among them, can pass a wire, a cord,… by a hole and remove it on the other to tie them or to coil them.

When we joined To with B, we have left ourselves a funnel “with two wings?. You can cut the wings but they reflect more sun reason why I leave them.

He sticks a piece of aluminum paper around the hole inferior of the funnel, with the shining part inside.

This complete assembly of your kitchen funnel.

For better stability, pon the funnel inside a box. For a use long play, one can make a hole in the ground to maintain the funnel in its site.

Final steps

At this point, or you are ready to put food or water within the baking boat, and to put the cover to him (To see the table of time of baking of foods)

Pon the wood block Within stock-market (at heart of this one). 10 xs use a piece of 10 xs 5cm (4? 4 xs? x2?). Then pon the boat of baking with the food or water upon the wood block within stock-market.

Next, it takes to the part superior of stock-market with the fingers and blows to swell stock-market. This will form a small greenhouse around the baking boat, that will catch the hot air. It closes stock-market tying his handles (if it does not have uses a wire or cord). IMPORTANT: the boat does not have to touch stock-market. Stock-market does not allow that the cold air touches the boat.

Pon stock-market completes with all contents within the funnel as it is in the photos.

Pon the expensive kitchen funnel to the sun.

It remembers: The light of the sun can damage the eyes: Please ponte sunglasses to handle the solar kitchen! The kitchen funnel is designed in such a way that the hottest part is at heart of the funnel, outside the reach of the body.

Pon the kitchen funnel in such a way that it captures the maximum of light. The design of the kitchen funnel allows him to capture solar energy during one hour, without needing being replaced. For bakings of more than one hour, it readjusts the funnel in such a way that this one continues having the maximum of light.

If we placed the kitchen before funnel a wall or window that oriented towards the North (in the Southern Hemisphere, and the other way around in the Northern Hemisphere) will be reflected major amount of light in the funnel. When more far one is of the Equator this wall will make more lack (and more in winter).

After cooking

It remembers, the jar will be very hot: It uses gloves or a cloth to take hold it! If you are warming up water in a hermetic container, you will be able to see that the water is boiling when you clear the cover to him - it sees with care!


  1. It avoids to soil or to leave tracks in the inner part of the funnel. You must maintain the inner face cleaning and brilliant cleaning it with a humid towel. This will cause that the kitchen funnel works perfectly well.
  2. If your funnel is opened, you can recompose tying it thus a cord or something between the sides that must again be locked up.
  3. For uses long play, you can make a hole in the ground to nail your funnel and thus to fix it against the wind. It covers your funnel or enters it at home to avoid that one gets wet when it rains.
  4. The boat can be hung near the bottom of the funnel with thread to fish (etc.), instead of putting a wood block underneath. An air flood stock market is put plastic surrounding the jar, to maintain the hot air. This one method allows the sunlight to beat by all the parts of the jar (or boat), which does that it is warmed up before. This one method is ideal to use it in months of winter.

Tests in Bolivia

The Benson institute of the BYU organized tests between the funnel kitchen and “old? the kitchen of box (or also Kerr-School call). The box kitchen cost 70 dollars (wakinlè) and was done almost everything of cardboard. The point of pasteurisation of the water cost almost two hours reaching. The report from Bolivia shelp: “the food cools off whenever you put or extractions the boats.? The solar kitchen of box could not boil eggs. Perhaps (a solar box a little more face would have worked better)

The Funnel Cooker dog also sees made from Mylar.Also in Bolivia winter tried on a solar kitchen of funnel of Mylar aluminized in the heat of. The water was pasteurised in 50 minutes, the eggs were boiled in 70, and the rice in 75 minutes. The people of Bolivia were enchanted of life with the invention Also we! (La Paz, Bolivia, August of 1996)

Pasteurisation of the Water and Milk

The water/contaminated milk kills every day thousands of people, especially young. the WHO informs that 80% of the diseases of the world are transmitted through contaminated water. The studies show that warming up the water to some 65º-70º C (150º F) is possible to kill coliforms, rotavirus, enterovirus and even Giardia. This is called pasteurisation.

Pasteurisation depends on the temperature and the time that warms up the water. But… As you know if the water is sufficiently hot? You can use a thermometer, but that would raise the final cost, by all means. When the steam leaves the boat and forms “dew? within stock-market, then the water is pasteurised to drink. (the trick is to warm up at least to 160º F (71º C) during six minutes.) If you scratch a painting strip you will be able to see when the water boils - then you can be surely absolutely.

It thinks about all the lives that can be saved with only pasteurising the water!


  • The baking boat warms up much, if eaten it would not cook. It lets cool the boat before opening it. Take it only with gloves or pliers.
  • It always takes sunglasses to protect to you of rays of the sun. We know that by nature we closed them but the glasses are important
  • Mantén plastic stock-market moved away of the children and moved away of the nose or the mouth to avoid the asphyxia possibility.

Cooking with the kitchen funnel

That you would cook in a furnace of moderate temperature? Then the same things would take the same in the kitchen of funnel and without burning themselves. The tables of down indicate the approximated time of baking in summer.

Vegetables (Potatoes, carrots, marrows, asparagus, etc.)
Preparation: They do not need water if they are fresh. To cut “to tronquitos? or slices. The maize can be cooked with or without the maize-cob.
Time of baking: On 1 hour and a half.

Cereals and Grains (Rice, wheat, barley, oats, millet)
Preparation: To mix two parts of water with one of cereal. The amount can vary following the pleasures. Leave it in soaking so that one cooks before. In order to make sure a good one cooked, it removes the boat past 50 minutes. TAKEN CARE OF! The boat will be very hot. Some protector type uses.
Time of baking: hour and a half or two hours.

It grazes and Soups of On
Preparation: First it warms up water until it boils (50-70 minutes). Then it adds grazes or the soup. It removes, and it cooks more during 15 minutes.
Time of baking: 65-85 minutes.

Preparation: If the vegetables are dry, leave them to soaking during one night whole. Ponlas in the boat with water.
Time of baking:
Of 2 to 3 hours.

They do not need water. Note: If they cook too much, the clear ones are darkened but the flavor is the same.
Time of baking:
1 hour or hour and a half. It depends on how the yolks are wanted.

Meat (Chicken, Lamb and Fish)
Preparation: They do not need water. When they cook more tender they remain.
Time of baking:
Whole chicken 1,5 hours cut or 2,5 hours; Lamb: 1,5 hours cut or of 2,5 to 3 hours to great pieces; Fished 1 hour or hour and a half.

Bread and derivatives
Preparation: To come since it would be made normally. The times of baking are based on the amount of mass
Time of baking: Bread; 1 hour or hour and a half; Cakes: 1 hour or hour and a half; You graze you: 1 hour.

Fruits toasted droughts (Peanut, almond, seeds of pumpkin, etc.)
Preparation: To put in the boat. Vegetal oil can be added if it is desired.
Time of baking: More or less 1 hour and a half.

Congealed and eaten precooked
If the package is dark, simply to put it in stock-market instead of to put the boat.
Time of baking: The time varies following the amount of food and the darkness of the package.

As using the solar funnel as Refrigerator or Refrigerator.

A university student (Jamie Winterton) was first in demonstrating that the solar kitchen of funnel can be used - at night - as refrigerator. Here this one fact is explained.

The kitchen funnel has the same assembly that it would have during the hours of sun, with two exceptions:

1. The funnel must be oriented towards the dark sky at night. It does not have “to see? (that is to say, does not have to be pointed) at any floor nor tree because the thermal radiation of the walls, trees, and clouds will even diminish the cooling effect.

2. The boat instead of one is better to put two bags surrounding, with spaces between the bags and stock-market inner and the boat. The HDPE bags and even the normal ones, since polythene is almost transparent for infrared rays, letting them escape at night to the “calorific decay? of the dark sky.

During the day, the rays of the sun are reflected in the boat that is warmed up immediately. At night the heat of the boat leaves towards outside towards the empty space, that is very cold (this is the one of the “calorific decay?).

As result, the baking boat now becomes a small refrigerator. Normally we reached a temperature some 10º C lower than the room temperature using this so simple equipment.

You can place two funnels at night, with boats with double stock market in the interior. A boat with a wood block underneath, the other hung man with thread to fish. Even though the temperature at night is of 25 ' 5º C. You will see that the temperature within the funnel has lowered to 15 degrees of blow, since its energy was radiated towards the open sky. If the outer minimum temperature arrives less than at 8 ' 6º C degrees - you will find that the water in both boats is ICE. A black container of PVC will work better than a black boat, since the PVC is a good infrared radiator.

You wish the complete planes with photos including?

By only $us4. - you can do. Questions a:

Miguel Vargas via
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