The flame of a candle shines quite nicely, but trying to warm up with it seems insane. Meanwhile, just as a light source, a candle is an extremely wasteful device. But as a room heater, it may be useful. Under a number of conditions.

California inventor Doyle Doss (Doyle Doss) and his company DOSS Products offer the original Kandle Heeter system, that is, the “Candle Heater”.

This strange-looking candlestick, says its creator, may be indispensable when disconnecting electricity. Its height is about 23, and its width is about 18 centimeters.

And from its appearance the upturned pot over the candle draws attention to itself. The main highlight of the system is hidden in this pot (and it is in the “past life” as a flower pot).

This pot is not simple, but composite. It is made of three pots of different diameters, nested inside one another and connected by a long metal bolt, on which a whole pile of washers and nuts are strung (the hole in the bottom is usually already in the pots).

Doss sells Kandle Heeter for $ 25 apiece (photo from heatstick.com).

This intricate combination of ceramics and steel Quad-Core is called, and it is designed to trap the heat from the candle. But why?

An ordinary candle, burning in the room, gives out heat, as it seems, quite a bit. But the point here is that its hot “exhaust” simply goes up and quickly disappears with ventilation.

Meanwhile, the energy supply in the candle is not so small. Moreover, with a hot stream of combustion products, most of its energy content goes away, and only a smaller part goes into the light.

The labyrinth cap over the flame collects energy and carefully accumulates it, heating up quite strongly (the central core is especially hot). And then this heat is slowly transferred to the air by the entire surface of the ceramic radiator.

The pots also help trap soot from the flames, which favorably affects the cleanliness of the ceiling.


The main "secret" of the invention is the Quad-Core radiator, a heat trap (photo from heatstick.com).

The inventor emphasizes that one such device in no way will save you in the winter when the heating and electricity are turned off, but, on the other hand, it is better than nothing at all.

In addition, although this simple design is designed primarily for emergencies (and not only at home, but also outside it), a mini-radiator candlestick can slightly reduce the cost of heating a room, adding a little warmth to a room occupied by people, while the house is “adjusted” by thermostats to a lower temperature. Here, however, still need to calculate the cost of one joule in the candle.

The heater is also equipped with a top-mounted stand that can hold a pot of soup.

Before the fresh Kandle Heeter can properly heat the room, you need to wait for the residual moisture to evaporate from the ceramics. It may take 3-4 hours, notes Mr. Doss.

But then the owner of this thing can fully enjoy the mild heat, issued by the heater for a long time. It is necessary to store the unused device in a plastic bag so that it does not absorb moisture from the air.


The scheme of the heater. The flame heats the rod (1), hot gases pass from the cavity to the cavity (2), each ceramic layer emits infrared rays, heating the next layer (3), the outer pot (4) eventually heats the room air (5) (illustration and photo from heatstick.com).

Doss writes that a 4.25 ounce wax candle contains about 1 thousand British thermal units of energy. In terms of customary values, this is approximately 120 grams and 1.1 megajoules.

If we consider that such a candle burns for 20 hours or a little more, then it turns out that its energy production is 55 kilojoules per hour, which corresponds to a power of 15.3 watts.

A regular candle without a glass or metal cup in Kandle Heeter is melting too fast (photo from heatstick.com).

However, according to some data, the total “useful output” of a wax candle of this size will still be higher. Closer to 3 megajoules. That will give an average power of about 42 watts. And if we carefully “look” at a paraffin candle, then perhaps we will find in it even more potential heat.

However, the exact number of heat of combustion is not so important. It is clear that such a candlestick cannot compete in the power of household electric convectors and oil radiators by 0.5-2 kilowatts. As long as there is current in the outlet.

On the other hand, and in the presence of a kilowatt heater, you can hardly burn for days on end if you don’t want to go broke on your electricity bill. And Kandle Heeter, as already mentioned, has more than 20 hours on one candlestick. The only important condition: it can not be left unattended. Still open flame.

The American innovator believes that such heaters should appeal not only to people sitting at home, but also to those who rarely show themselves there, preferring to travel far from the bustle of civilization. Kandle Heeter should be a simple and cheap alternative to primus and other kerosene. And someday he can save the life of a person who, say, by car in a snow trap, in a blizzard.

Finally, this tiny firefly is just cute. “Kandle Heeter should remind us all that once we (people) were sitting in caves at night around the fire and telling each other stories,” says the inventor.

Ecology of consumption. Life hacking: A cheap and efficient heater can be created using clay (ceramics), a metal element and a candle.

Simple natural materials in one form or another continue their “life and work” as components of modern compositions. Thus, ordinary clay has gone from free and publicly available raw materials for the construction of the first houses to the nano-component of the composition of heat-insulating paint (liquid ceramic insulation). In its raw form, it was coated with walls for insulation, then they began to mold and burn - they turned out dishes and bricks.

With the development of steelmaking, clay was learned to swell - this is how keramzit and a whole section of science appeared - “Use of expanded ceramic materials”. In the end, it was formed into balls with a diameter of 0.02 mm with a technical vacuum inside. And everywhere the clay was in demand due to its basic property: in the baked form (ceramics), it effectively accumulates heat. This proves once again that everything that man needs for life has already been invented by nature.

Is it possible to distribute heat from the fire

Another property of ceramics, derived from the heat capacity, is the ability to distribute heat evenly throughout the entire volume (except for the heating point). In other words, if we take something ceramic (for example, a brick) and put it on something hot (for example, a gas burner), the following will happen:

  • brick will begin to accumulate (utilize) the heat of the flame of the burner;
  • the temperature will be evenly distributed throughout the volume of the brick and will reach its edges;
  • on the planes of the brick will be a heat exchange with the surrounding air;
  • as a result, the heat exchange area will increase from the area of ​​the flame tongue to the area of ​​all the planes of the brick;
  • however, the temperature will decrease in inverse proportion to the surface area (the larger the area, the lower the temperature).

The quick-witted reader, of course, understood that the principle of operation of the Russian stove was described above. Our task is to create an equally effective device, but on the basis of a candle.

How does the "eternal" heater

Despite its small size, the flame of a candle has the usual 100 ° C for burning. The temperature in the room should be approximately +24 ° C. The difference is 76 ° C. Where does she go?

When burning a conventional candle, the following occurs:

  • warmed by burning air rises to the ceiling;
  • under the ceiling, it is mixed with the topmost layer.

Due to the large temperature difference (76 degrees), the surrounding air does not have time to mix with the exhaust gases of combustion, and they rapidly rise to the ceiling. A column of hot air forms, as it were, which disperses at the top. We will dispose of this heat with the help of a “trap” of ceramic domes.

What can a heater be made of?

So, to build a "miracle micro-stove" we need:

  • flame
  • burnt clay (ceramics)
  • metal

The scope of ceramics is limited only by the imagination of the engineer. In this case, we are only interested in cheap cheap materials, in particular, dishes. It was not for nothing that in ancient times they used clay pots in the oven - they keep warm for a long time. The range of ceramic household products today is huge, but we will focus on ordinary flower pots. Dull in appearance, they will help us solve the problem of auxiliary heating.

The second component of the heater is the heat source. The first thing that comes to mind for indoor use is a regular candle. Of course, there are a variety of types of gas and kerosene burners, but low cost and availability for us in the first place. In addition, the candle has no shelf life and can be stored in the cold.

The third component is a record holder in thermal conductivity and an outsider in heat capacity is metal. Its property to quickly heat up and give off heat (low heat capacity) will play into our hands when creating a heat lamp.

We collect the thermal lamp the hands

What you need:

  1. Ceramic (flower) pots trapezoidal with an outer diameter of the bottom 50, 100 and 150 mm in 1 pc. At the same time, the smaller pot should be about 25 mm below the big one.
  2. Stud with a thread diameter of 6-12 mm. It must pass through the openings of each pot. If necessary, drill holes to the desired diameter with a drill bit on the tile.
  3. A washer for a stud with an outer diameter equal to the inner diameter of the bottom of the smallest pot - 20 pcs. Nuts 7–8 pcs.
  4. Frame, suspension or stand of arbitrary shape, satisfying the technical requirements (conditions) described below.
  5. Optionally - fireplace seal or non-flammable (paronitovye) gaskets.

Operating procedure

1. Install the stud into the hole of the largest pot and tighten the nut from the outside.

2. Put some washers on the pin inside the pot, fix them with nuts if necessary.

3. Install the middle pot on the hairpin.

Attention! The outer edges of smaller pots should be located inside a large dome at a depth of 20–25 mm.

4. Fix the middle pot with washers and nuts.

5. Expose and fix the small pot.

6. The edges of all three domes should descend in steps of 20-25 mm. Adjust the depth of planting by adding washers and nuts.

7. If the distance from one bottom to another is perceptibly large, fill it with washers in a run-in - this will give a greater thermal conductivity of the rod.

8. Install the design above the candle so that the stem of the stud is located strictly above the flame at a height of 30-50 mm.


9. Further adjustment is made empirically on the basis of observations.

The use of gaskets and sealant. Praising ceramics, we tactfully bypassed its most inconvenient drawback - fragility (causticity). Even a solid brick crumbles, falling on concrete, what to say, and flower pots. Assembling the lamp, you should very carefully tighten the nuts - it is worth a little to tighten and the wall will burst. There is also the risk of accidental splitting during operation or at the time of carrying. Hard metal studs crumble ceramics and may crack. To soften their contact, use sealant or non-flammable gaskets.

What will be the benefits of the "pot" heater

At first glance, the design is extremely clear, but does not cause confidence. It should immediately make a reservation - do not rush to cut out the radiators of steam heating - our lamp will be an “apprentice”, but not a “master”. The use of such devices in each room will reduce the overall supply temperature of the boiler by several degrees for free - and this is the result!

Let's conduct a primitive heat engineering calculation based on publicly available data and logic:

  1. A wax candle weighing 120 grams (diameter 30 mm) contains about 3 MJ of energy.
  2. The approximate period of burning of such a candle is 20 hours.
  3. During this time, it emits about 140 kJ of energy, which is about 42.5 watts.
  4. Paraffin candles give a greater effect of heat.

By picking up the most efficient candle, we can achieve 50–55 W of thermal energy at the output, and this is already 10% of the power of the electric heater at 500 W.

Attention! Fire hazard The heating element is an open flame. The lamp can not be left unattended.

Application area

Elementary design based on "penny" materials will serve for a long time with careful handling. The heater does not require any conditions for storage, service life, maintenance or replacement parts. Simple, like all ingenious, it will support in the forest overnight stays or during a power outage, as well as in extreme conditions.

  1. In places where there is no electricity: tents, dugouts, shelters, cars, caught in a blizzard.
  2. In places where there is electricity: a small but pleasant saving on heating costs.
  3. If you assemble a thoughtful frame, then you can hang a small container (a kettle, a mug) over the candle and heat the water.

That is such a simple and reliable assistant turned out. It will become not only a warm place in your interior, but also an interesting decorative ornament. published by

Nowadays, classical wax candles, which for centuries have replaced electric light sources, are extremely difficult to find. Instead of wax products paraffin candles are commonly used, which are simpler and cheaper to manufacture. Unfortunately, the paraffin benefits end there. But the disadvantages of a derivative of oil is full. Stearin, chemical impurities, fragrances and paraffin itself are toxic when burned and are considered strong carcinogens. How not to make a mistake and choose a natural candle?

Candles made from natural beeswax do not contain harmful components and are completely safe. In addition, wax candles contain a powerful disinfectant component - propolis. To distinguish paraffin wax candles from wax can be on several grounds, which in the complex will not allow to make a mistake and help make the right choice.

By smell

How to distinguish paraffin wax candles? Very simple. By smell. Paraffin is odorless, while the natural product has a distinct aroma. During burning, the paraffin candle emits no odor, while the wax in the melting process produces a faint, but still noticeable aroma.

To the touch

Candles made of beeswax, regardless of the method of production (manually or at the factory) have a pleasant to the touch structure. Smooth, with a slight roughness, they are significantly different from the products of paraffin, whose surface is oily, resembles soap.

During burning

Wax candles crackle slightly to form a neat drop of melted substance under the tongue of flame. They burn for a long time, practically without forming streaks, while emit a barely perceptible odor. In turn, paraffin melts quickly, without emitting third-party odors and aromas into the atmosphere. The burning time is several times less than that of a natural product.

Plastic

To distinguish paraffin wax candles from their consistency of the material will help. When cutting with a knife, paraffin crumbles, while the product itself has an adequate supply of hardness. The wax is much softer and more plastic than it resembles clay. If it is cut, instead of crumbs and cracks an elegant even cut is formed.

A competently selected set of candles can transform a room, give it the missing notes of mystery, or vice versa, illuminate dark corners at a later time. For example, the original designer candle Woven Bamboo perfectly fit into the interior, decorated in a colonial style. In turn, a set of candles from natural wax, stylized as river stones, will organically fit into the interior of the bathroom, create the illusion that you are in the spa. Admirers of vintage design will surely appreciate a beeswax candle stylized as a ball of wool!

Despite the fact that now there are many different kind of burners, tiles and heaters - there are still fishermen who heat the winter tent with paraffin candles.

For all the seeming frivolity of such an approach, there is a very good potential, because the calorific value of paraffin is comparable to that of other petroleum products. Is she 48 megajoulesthat even a little more than gasoline (44 mJ). If to be expressed in more or less everyday language, leaving the tedious physical calculations behind the scenes, it will turn out that a kilogram of paraffin, burning for an hour, will give as much heat as a 13-kilowatt semi-industrial thermoscan.

Now we will calculate all the same for one paraffin candle. For example, take the "Ikeevskaya" (these are candles in the form of shaybochki in cups of aluminum foil).

The weight of such a candle is approximately equal to 12 grams. This amount of paraffin will be 83 times "weaker" than a kilogram of this substance - 157 watts versus 13 kilowatts. But we, again, have defined this “heat power” given that paraffin is completely consumed in an hour. And the burning time of one candle (according to the manufacturer) is 4 hours. After the elementary calculations it becomes obvious that output power of one “IKEA” candle - 39 watts.

At the very miniature gas stove on disposable cylinders, the power does not exceed 2 kilowatts, and this is more than enough to heat a tent. Hence the conclusion - in order to compete with this power, we will need as many as - 50 candles.

Of course, this figure - for a good - 25 degrees below the frost behind the wall of the tent. It is with him that you begin to drive tiles for a long time at full power. In the more "warm" weather candles may need half as much. And even tripled, especially if our goal is not so much to heat the tent as to keep the holes in the ice-free state.

But still consider the option with the 50th candle - as the most expensive. In a compact arrangement, all candles will occupy an area of ​​about 40 by 20 centimeters - the same amount as the average tile. With the ignition of the "candle battery" will have to tinker a bit.

At 8 hours of fishing you will need 100 pieces of candles (this is about 1.2 kilograms of paraffin).

In the “conversion to rubles”, even more interesting figures come out, especially if you compare paraffin with the same gas. In case of using the burner - at 8 o'clock fishing, you will need 2 half-liter cylinders worth 80 rubles each - this is 160 rubles for all fishing. A pack of 48 candles costs 130 rubles, two packs - 260. It turns out that we will save 100 rubles on gas. However, candles are indisputable advantages compared to “blue fuel” - they are not frozen in the cold and can be lit at any temperature. Well, by itself - do not require any additional equipment.

It turns out that refined technical paraffin brand P-2 at wholesale prices is quite tolerable - 40-50 rubles per kilogram. And if there was a refueled burner working on paraffin - the potential of this fuel could be fully revealed. Then paraffin would be a good alternative to gas and gasoline.

But this is a topic for a separate conversation that goes beyond the scope of this article.

When it comes to a candle, an analogy immediately arises subconsciously with something negligible, insignificant, extremely weak and incapable of anything. This is due to the historically established tradition, to compare, for example, the brightness of light bulbs with the brightness of a candle, or to show the power of a telescope that Moscow “sees” a candle in Vladivostok. Particularly fascinating to the audience is the work of the Stirling engine, which not only cheerfully turns from the air heated by a candle, but also provides electricity, from which the light bulb glows much brighter than the same candle.

The author was unable to find information on the thermal capacity of a regular stearic or wax candle on the Internet. But in one very old reference book on physics it is said that the heat output of a stearin candle is 80 kcal / hour, and that of a kerosene lamp with a flat wick is 60 kcal / hour. After conversion to conventional units, we obtain a candle power of 93 watts, and a kerosene lamp - 70 watts. It was these numbers that first caused bewilderment, and then mistrust, and were the reason for this study.

Theory

To heat any body of mass m, from temperature T 0 to temperature T 1, it is necessary to bring thermal energy Q to it. Moreover, the greater the mass, and the larger the temperature difference, the more thermal energy will be needed for heating. Thus, you can write:

Q = cm (T 1 -T 0) (1)

where c is the specific heat, reflects the fact that some materials heat easily, and some require very large amounts of thermal energy.

On the other hand, we know that the final temperature depends on the heating time, and the longer it is heated, the higher the probability of getting a higher temperature. This is due to the rate of heat supply (absorption) or to the power, which is defined as: P n = Q / t, where t is the heating time. Therefore, we obtain an important equation

P n t = cm (T 1 -T 0) or P n = cm (T 1 -T 0) / t (2)

in which all quantities can be measured and calculated. It should be noted that the equation (2)   It characterizes the power absorbed only by the heated body, i.e. heating power. If this equation is rewritten as follows

T 1 = (P n / cm) t + T 0, (3)

then we get a recommendation for action: it is necessary to measure the temperature of the heated body at regular intervals, plot the temperature versus heating time and calculate the power P using the slope of the straight line, and through it Q, if necessary.

But in fact, the linear dependence T (t) is not always observed. The thing is that as the temperature increases, the body itself begins to heat the air and surrounding objects. Those. as body temperature rises, heat loss also increases, and finally there comes a time when the rate of heat supply is compared with the rate of loss, and the body temperature no longer rises. Therefore, in the general case, the dependence T (t) is not linear and the equation (3)   will be valid only with small changes in T 1 and t.

The power loss is also proportional to the temperature difference and is described by an equation similar to the equation. (2)   with the only difference being that the minus sign appears. Therefore, we can write:

P n = cm (T 1 -T 0) / t (4)

T 1 = - (P p / cm) t + T 0 (5)

It follows that, by observing the cooling process, which will also not be linear, we will receive information on the power of thermal energy loss at the corresponding body temperature. The equation (5) as well as the equation (3) , will be valid only with small changes in T 1 and t.

Thus, the thermal power that we take from the flame of a candle is equal to the sum of the power that the heated body absorbed and the power it scattered into the surrounding space, i.e. P sums = Pn + Pn. But we have not yet taken into account that part of the heat capacity of the candle, which did not participate in the heating of the body at all. Therefore, we can talk about the efficiency of the process of heating the flame of a candle, and define it as follows:

Efficiency = (P n + R p) / P total (6)

It should be noted that the efficiency of a candle essentially depends on many parameters of the heating process, even on such as the presence of drafts or soot from the flame on the surface of the heated body. But most importantly, we do not know reliably what the candle is made of. And, as a result, we cannot determine the calorific value of both the main combustible materials that make up the candlestick and those additives that can radically affect the combustion process. Therefore, of practical interest is the P sum, i.e. that thermal power that can be taken from the flame of a candle. But this power depends both on the modes and methods of heat supply to the heated body, and on the materials and design of the candle itself. Therefore, this parameter can also vary widely and requires careful analysis in each particular case.

Approximately estimate the efficiency of the process of heating by the flame can be based on experiments with heating on a gas burner. In this case, the calorific value of the gas is known and the volume of the burned gas is known. For example, with a burner power of 2840 W, the efficiency of the heating process of a 2-liter kettle is 33%, and with a burner power of 720 W - 58%. Considering the fact that the flame of the candle washes over the heated body under the action of natural convection (and the gas from the burner comes out under pressure and, naturally, with greater speed), we can count on the efficiency of the candle more than 58%.

Experiment

In the period from April 21 to May 6, 2011, 3 experiments were carried out in different temperature conditions, with different types of candles and with different thermal insulation of the heated body.

Experiment number 1. The air temperature is 16 degrees at the beginning and 17 at the end of the experiment. A glass chemical cup weighing 56 grams, in which there were 100 milliliters of water, was used as a test body.

The water temperature was measured with a mercury thermometer with a scale from 0 to 110 degrees Celsius every minute. Accuracy of temperature measurement ± 0.2 degrees. Thermal insulation was not applied. Candle - Chinese aromatic (strawberry smell) in an aluminum cup. The kinetics of heating and cooling is represented by curve 1 in Fig.1. As follows from the graph, the relative linearity of the dependence T (t) is observed only at the very beginning of the heating process, and with increasing temperature there is an increasing deviation from linearity. This is a manifestation of increasing heat power losses.

Figure 2 presents the results of calculation by the formulas (2)   and (4) absorbed thermal power and diffused into the surrounding space. At a temperature of 30 degrees, water takes away 30 watts of heat from the flame of a candle, at a temperature of 60 degrees - 20 watts, and only 10 watts go to heat, and the remaining 10 watts dissipate. “Parade of points” in the range of 56 - 66 degrees is caused by the formation of bubbles air on the mercury bulb thermometer. Therefore, in the following experiments, not tap water was used, but previously boiled and cooled to room temperature.

Experiment number 2. The initial air temperature in the room is 27 degrees and 26 degrees. A tin cup weighing 32 grams, in which there were 100 milliliters of water, was used as a test body. The cup was heat-insulated from above and on the side with 5 mm thick foiled polyurethane foam mat, which is usually used for floor insulation. The candle is also Chinese only with the scent of jasmine. Visually, the flame of this candle was larger and brighter than in the previous experiment. The kinetics of heating and cooling is represented by curve 2 in Fig.1. As follows from the graphs, after 40 minutes of heating, the water successfully boiled, and the process of cooling to 35 degrees stretched for 80 minutes.

Figure 3 shows the results of calculations, from which it follows that in this case a power of more than 40 watts can be obtained from the flame of a candle. Since the thermal insulation did not demonstrate unqualified advantages, the following experiment was performed according to the method of the first experiment.

Experiment number 3. The air temperature in the room throughout the experiment did not change and was 22 degrees Celsius. Used souvenir candle (New Year) still Soviet production. The kinetics of heating and cooling is represented by curve 3 in Fig.1. The peculiarity of this candle was that in the process of burning molten paraffin flowed from the burning zone. There were three such cycles. After each outflow cycle, the height of the wick increased, and, of course, the height of the flame increased. Thus, in the process of heating the candle inflamed. This is clearly seen in Fig. 4 for the minima at 5, 9, and 16 minutes of the experiment.

The maximum power that was obtained from this candle was 50 watts. To assess the efficiency of the flame heating process, experiments with heating a 2-liter kettle on a gas burner were continued. Figure 5 shows the dependence of the efficiency of heating on the gas flow rate. Near the corresponding points, the burner power and boiling time of 2 liters of water are shown. The monotonous drop in efficiency with increasing gas flow rate indicates that the heated air, passing with greater speed, does not have time to give heat to the kettle.

It is interesting to compare the results of experiment No. 3 with the results of Fig.5. The amount of heated water is 20 times less (2 l / 100 ml = 20), and the boiling time is exactly the same, 22 minutes. And the average heating rate is also almost the same: 4.1 hail / min for a gas burner and 3.95 deg / min for a candle. So we can assume that the power of the candle is 20 times less than the power of the gas burner, i.e. 1180/20 = 59W. Thus, the efficiency of heating by the flame of a candle is quite high (from 40/59 = 68% to 50/59 = 85%)

The results of experiment No. 2 are in good agreement, although the boiling time is somewhat different. And the heating rate of the candle is even higher than that of the burner, 3.82 degrees / min versus 3.26 degrees / min (up to 80 degrees). We can assume that the power of the candle is slightly less than 720/20 = 36W. If we take the average between 40 watts at the beginning of heating, and the 20th at the end (Fig. 3), then it is so. And the efficiency of 83% (30/36 = 83%) is fully justified, since the glass was thermally insulated.

The performed experiments unexpectedly answered another important question: “What is the heat capacity of the tea cup, from which the Stirling engine also works?” The answer is simple, if the cup has a capacity of 100 ml, then its power is naturally equal to the power loss, i.e. about 15 watts (in the range of 70 - 90 degrees). If 200 ml., Then 2 times more, that is, about 30W. In a two-liter kettle, the power loss is naturally 10 times greater, and, as the experiment shows, is 250 to 300 watts.

It remains only to measure the thermal power of the palm in order to assess the energy characteristics of this type of stirling.

findings

Thus, the heat output of a 93-watt candle is not fiction or error, but an objective thing to be reckoned with and used to its fullest “power”. It is necessary to rethink our attitude to the candle and to the engines from it working. If before these engines were treated like toys, as technical fun, as training before creating something more serious, then after realizing the true power of the candle, it is clear that there is nothing more serious than engines that work from a candle.

So, candle. This is the most necessary item in the backpack of tourists, travelers, hunters, fishermen, climbers, in a word, people who temporarily leave the space covered by civilization and are left alone with nature. But the achievements of civilization while they do not let go, in a backpack are such items as a phone, flashlight, camera, video camera, GPS-navigator, laptop, but who knows what else. And all these civilization gains require electricity, the stock of which is rapidly melting during the first 2-3 days.

Having a stirling generator with an efficiency of 10%, which is powered by a 50-watt candle, we get 5 watts of electricity. This is quite enough to recharge all electronic devices traveler. And if you also have a 200-watt candle, then you can safely and for a long time leave the embrace of civilization.

Thus, maximum efforts should be directed not at increasing the power of low-temperature stirling, but at increasing their efficiency, at least up to 5%. Then these devices from the category of toys immediately go into the category of the most necessary things and not only in a backpack. And the second thing worth thinking about is to increase the power of the candle to 150-200 watts. It would be nice, and control its power in the combustion process.

Kharkiv, April - May 2011