Complete guide on stoves and oven walls heaters: what they are, the history, characteristics, energy performance
The oven stoves are more environmentally friendly, more efficient, healthier, safer and more beautiful than all modern heating systems. Why are not there more and how you can do to bring them back?
A wood kiln is a kiln very efficient and robust that radiates heat throughout the day. In the United States it was introduced only 20 years ago, but in Europe the technology is at least a thousand years old. Especially in Russia, Scandinavia and Central Europe in the stove oven has a long and rich tradition.
In the eighteenth century, several European governments financed research to improve the technology as a way to overcome a severe shortage of firewood: a green technology before the term existed. However, its further development and and its spread were thwarted by the arrival of coal, gas and oil. The oven stoves are large, heavy and slow, but they offer so many advantages that - again - deserve to be subsidized by the government.
Most people think that the metal stove was the successor of the outbreak and the fireplace, and if you look only to the United States, this is true. In the New World, there was never shortage of firewood and therefore no incentive to improve the inefficient fireplace. But in Europe and the north, there was an important and successful link between the fireplace and the metal stove.
E 'known as the Russian stove, Austrian, Swedish or German, or "kakelugn" (in Swedish), "pechka" (in Russia), "Kachelöfen" or "Steinofen" (in Germany and Austria), and as "TULIKIVI "(in Finland).
Broader terms are oven tiles, brick oven, ceramic stove, tiled stove, heater or radiator stone masonry. The technology is more closely related to the baked traditional metal stove - so the German term "Kachelöfen" (oven stove) describes it best as an umbrella term.
Stoves oven already appear in the drawings and paintings in the fourteenth century (see illustrations above and below). I'm actually the first heating equipment in history. First, the Romans had invented the hypocaust, a precursor of the central heating, but that knowledge was lost almost completely when their civilization had collapsed.
The stoves are traditionally wood-fired oven, but today they can also be built to work with the gas, or alternatively with both fuels. They can also cooperate with a central heating system. A wood stove can be any shape or size can be almost invisible, built inside a wall or in a basement, or it can be an impressive masterpiece in the middle of the living room.
Stone to metal
The most essential feature of a stove furnace is that it is made of some kind of stone or brick, while all our modern equipment are made of steel. The metal heats up faster, but just as quickly cools. Then, a heating metal must be fed almost continuously.
The stone takes longer to warm up, but once hot, holds the heat much longer. A wood oven is turned on for a short period, from a quarter of an hour to an hour or two and only once or twice per day. A wood-oven media after emits heat for at least 12 hours.
Pipelines for the smoke
Most of the heating system consists of a maze of pipes and rooms for smoking. Their purpose is to keep the hot gas inside the oven for as long as possible, so that the stone can absorb the heat before it comes out from the chimney.
The energy efficiency of a stove furnace is between 80 and 90 percent, compared to 40-50 percent of a metal stove or a centralized system, and only 10-15 percent of a fireplace - where most goes away from the fireplace. One of the most impressive features of a wood stove (wood supplied) is the boiler, which is ridiculously small compared to the stove itself.
Thanks to the high efficiency, a modest brick or tile stove (which heats a room of 60 square meters) needs only 6 cubic meters of timber per year: a tree. If you have a small garden, you can easily feed your stove oven made of your own pruning - the thin wood is very suitable for tile stoves, although it needs to be fairly dry.
Radiant Heat
All our heating contemporaries heat a house or a room through convection heat the air. A wood-oven does it by means of radiant heat: infrared radiation, comparable to the heat of the sun. In a room that is heated by a wood stove, a thermometer can measure something difficult.
The effect is comparable to that of a skier that you can enjoy a schnapps while sunbathing, despite the cold temperature. Radiant heat is not (only) heats the air, but also in particular a skier's body directly.
A wood oven works the same way the sun does not heat the air much, but the floor, the walls, the furniture and the people in the room. These objects in turn emit the absorbed heat to their surroundings - similar to a city that emits heat after a long, hot summer day when the walls and pavements slowly release the sun's heat.
This may sound a bit 'strange computer wizards for the twenty-first century, but until 150 years ago, the heating was by definition radiant heating. The convection heating is a very recent invention, and has more disadvantages than advantages.
Hot air balloons
The convection causes a constant movement of air in the house, because the warm air is pushed upward (the principle of a hot air balloon) and the cold air is sucked into (all convectors need a constant supply of air). Hot air rises to the ceiling, while the people who need to be heated is located on the floor. This is not very efficient. In addition, it is always too hot near the radiator or the stove and always too cold on the other side of the room.
Secondly, the convection is not healthy. The house dust begins to remain suspended and this irritates the respiratory system. In combination with the dehydrating effect of the hot air and because of the strinamento dust on metal surfaces of the radiators and stoves, this leads to an unpleasant climate alkali that can cause headaches.
This problem is solved mainly by humidifiers or by electrical heaters to water, placing a mixture of steam and air in the room. Unfortunately, this creates the ideal conditions for dust mites and fungi disgusting. You can not open a window to ventilate, because otherwise the hot air goes away quickly.
Sleeping on the stove
A wood-oven has none of these disadvantages. Since hardly warms the air, there is no dust circulation. As the surface of the oven does not become as hot as the surface of a metal stove or a radiator, there is strinamento dust.
And because the air does not rise, the heat is evenly distributed in the room, instead of going up to the ceiling (or down the stairs to the upper floors). This means that you can open a window upstairs to ventilate the house, without losing energy.
Since the exterior of a stove oven does not become too hot, there is no danger of burning. This quality is sometimes used to integrate a bench or a sofa in the stove, a luxury that no other heating system can offer. In Russia it is a widespread habit to install a bed on top of the stove.
Thanks to their external warm (but not hot), oven stoves offer other possibilities. It is very suitable to keep hot pots and containers, and for drying laundry - the metal stoves or radiators you are usually too hot for that. Furthermore, a ceramic stove can be equipped with hot surfaces and with a real oven to be used as a kitchen.
Complete combustion
The oven stoves are an alternative to all the modern heating systems, but compared to wood stoves have another important advantage. More and more people choose wood as a heating source, so as not to be dependent on the unpredictable price of oil and gas.
In a sense, this is not a bad thing, because unlike oil and gas, wood is a renewable fuel and neutral with respect to the production of CO2 (the CO2 that is produced by burning the atmosphere was subtracted from the figure in the previous years ). The problem is that the wood-burning stoves are not very efficient, and highly polluting.
The wood can burn without air pollution too, but then the temperature must be high enough: from 1100 to 1200 degrees Celsius. In that case, 99 percent of the wood is converted into CO2 and water vapor, almost without smoke. A wood stove metal, however, only reaches temperatures of 600 to 750 degrees, with incomplete combustion as a result.
The wood is formed by two thirds and one third combustible gases or combustible material. In the case of incomplete combustion, these gases as they leave smoke from the chimney. In regions where many people use wood heating, air quality deteriorates dramatically (incomplete combustion is more polluting than burning oil or gas).
Overheating
In a wood stove fire is controlled by decreasing the flow of air, otherwise the room will overheat for the rapid release of heat from the plant metal. Because a stove oven does not immediately release the heat of the fire, but stores it temporarily in the mass of masonry, wood can be burned at a very high temperature without overheating the room.
A stove oven can be powered at peak, even if you want a lower temperature: in that case simply feeding with a piece of wood smaller or feeding less often.
Complete combustion is not only beneficial to air quality and efficiency, it is also safer. In the case of incomplete combustion, the fire fills most of creosote, which can lead to a fire in a fireplace the day that the stove was fed to the maximum (this is the reason why a chimney should be cleaned regularly).
Instant heat
The oven stoves also have some disadvantages, although none of them is unsolvable. Probably the biggest disadvantage is the fact that a tiled stove or masonry does not release the instant heat to which we are accustomed.
If you turn on a gas stove, you will almost immediately rewarded with the heat. But a stove furnace needs a couple of hours before starting to radiate heat. This is not a big problem during long cold periods, because once the cycle has started, and the stove is fed a little 'every morning, the house is always warm.
And 'less obvious during periods with large fluctuations in temperature, or when you travel a lot. You can do your best, wearing warm clothes for example, or in a less low-tech installing an extra heater. - As a gas stove - in the same room.
This second heat generator can also be a ceramic stove much smaller, or a ceramic oven (a small ceramic stove only used for cooking). The smaller one can be used to warm the room quickly enough while the larger one is warming up. A tiled stove equipped with two furnaces, one for heating and one for the kitchen, offers the same possibilities.
Overheating
A masonry stove will not allow fine adjustment of the temperature as other heating appliances. If a wood stove or gas is heating up the room, and you can lower the temperature drops rapidly. With a tiled stove this is impossible to do.
If you burn too much wood or gas in the morning, this decision can not be reversed during the course of the day. There is no other option than to open the window, and this is not quite so efficient. Heat a room at the right temperature requires some practice and attention, especially in climates that are not those of Russia or Finland.
A third disadvantage of the brick stove is a consequence of radiant heat. A wood-oven heats only the room where it is placed. Open the door will not warm the room next door, because it is for a large part in '"shadow" of the radiant heat.
This is again comparable with a hot sun on a winter day: if you go to the shade from the sun, radiant heat there is no more, and what you hear is the air temperature. A gas stove or wood does not do much better, but a central heating system seems to be no doubt winner. However, a brick stove does not exclude a centralized system.
Walls hot
The walls hot or warm floors are another way to apply the radiant heat. Here, the hot water does not flow to radiatri of metal as in conventional centralized system, but through plastic tubes which are embedded in the walls (or in false walls). Because of its porous surface of a stone wall can not heat the air, but radiates as a stove brick.
The warm walls can be combined with a wood oven. The stove is connected to a boiler, which distributes the hot water through pipes in the walls or floor throughout the house. In this way the brick stove (assuming it is powerful enough) can heat all the rooms of the house, something that is otherwise not possible. Similarly, a brick stove can produce hot water for a family.
The warm walls can also be combined with an existing central heating system. This is already a step in the right direction, because the power consumption drops (the water should not be so hot as in the case of a plant central traditional, since the heat is irradiated on a large surface area), and you can have a better climate .
As a third possibility, a wood-oven can also be connected to a network of radiators metal, but in that case you lose the advantage of radiant heat. The radiators steel flat heat the air.
Heavy, bulky, expensive
Another important disadvantage is that the furnace stoves are rather large and heavy. A modest brick stove weighs at least 800 kilograms, and the larger (especially in the U.S. and the old Soviet Union) can weigh up to 5 tons and more. There are smaller models, but lose some advantages when compared with their older siblings (must be fed more often, and do not always reach a complete combustion of the wood, or the same energy efficiency).
A tiled wall must be large and heavy, there's nothing to do. Heating appliances metal have the undeniable advantage of being compact.
The stoves masonry cost even 2 or 3 times more of the other heating systems. As the costs of energy consumption are lower, and a wood-oven well-built lasts a lifetime, this investment will pay for itself after a while. However, you have to be able to go to the expense.
In Finland, a major producer of plants soapstone buying a stove oven is subsidized by the government, with the result that 90 percent of new homes use them.
The oven stoves are expensive because they are produced crafts. Are not suitable for mass production (although efforts have been made in this direction), and are therefore not of much interest for the heating industry. Prefer to sell, for example, pellet stoves.
The pellet stoves
A pellet stove is the only wood-burning stove which achieves a complete combustion as does a wood oven. To do this sophisticated technology is used - which is also the weak point of this heating system.
A pellet stove needs electricity to power the entire high-tech (conveyor, ventilation, temperature control, etc.) which means that this use of electricity must be taken into account when calculating the environmental impact. In addition, a pellet stove stops producing heat when there is an interruption of power supply.
A pellet stove can only be fed with pellets, small wooden chopsticks, which are produced in the factory. The wood cutting or pruning can not be used in a pellet stove. Produce these pellets requires a lot of energy.
Another consequence is that once you are dependent on the unpredictable price of an energy supplier. In addition, a pellet stove mainly warms the air and hardly emits radiant heat, so there is an improvement in health than a wood stove, a gas stove or a central plant. Because of all that high-tech has inside, however, a pellet stove costs as much as a wood oven.
False stoves oven
Now that the oven stoves are regaining back some popularity, manufacturers of heating equipment metal try to take a slice of the pie. Someone has started to provide in the traditional way, sending masons to your home to build any stove oven you want.
The majority have manufacturers, however, now uses radiant heat as a promotional strategy with a patina of green. There are now stoves on the market that seem stoves oven, just that they are not. Normal stoves are made of metal, covered with tiles. Grateful thanks to betray that let in the cold air, something which a stove oven does not need.
Of course, the tiles will become hot when the stove works, but as soon as they cool off. These devices are advertised as an ideal combination of both technologies, but are simply convection heaters. Unlikely to emit radiant heat, the dust and have a strinano based rendering. Yet they sell.
Burning forests
The stove oven is the only technology that allows a clean combustion of wood without the need for other energy input, and therefore is the only technology that promises environmentally friendly alternative to the declining resources of oil and gas.
The crucial question is whether the land can produce enough wood to keep you warm a significant amount of people. The current energy crisis is not the first in human history. From the fifteenth century, some countries in Europe already had to deal with a serious shortage of firewood and this became an acute problem in the seventeenth and eighteenth centuries, which was "solved" only by the arrival of coal.
It seems impossible that the current population of Europe will again be heated by wood, as there is a lot more people at that time. But there is some hope that the potential is much larger than we might expect.
The massive deforestation of the Middle Ages was a result of the use of the fireplace, which needs ten times the fuel efficiency of a stove oven (wood was also the main construction material). Even if the stove is old brick nearly ten centuries, diffone on a large scale only in the nineteenth century, and even after only a few European countries.
The technology's potential was never fully developed due to the start of the industrial revolution, and the abundance of coal. The research has yet to reveal the amplitude of the potential of wood as fuel if we used the stoves in the oven, but is certainly greater than that of a return to wood stoves.
10/10/2012
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Translated via software
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Source:
Italian version of CercaGeometra.it