One of the most common types of fuel used to heat country houses is wood. They are available, inexpensive and burn well, releasing a large amount of thermal energy. But the burning temperature of firewood is not the same for all types of wood, so there is a need to understand this issue and determine which firewood burns better and which worse. Why this is necessary is probably clear without explanation.
Let's start by reminding you that without oxygen, nothing on our planet will burn. Therefore, the supply of air to the combustion zone is the main criterion for the correct process of burning wood. But wood is divided into species, each of which differs from the others in chemical composition and density. Below is a table of the calorific value of firewood of various types of wood.
As you can see, the difference is even very significant, especially between spruce and alder. From this table it can be seen that, for example, when burning one cubic meter of spruce firewood, less heat will be released than when burning the same volume of alder firewood. It turns out that in order to obtain the required specific thermal energy, you will have to burn more logs from spruce than from alder. And these are not only quantitative fuel costs, these are financial costs from your wallet.
Dry firewood
Attention! The combustion efficiency of wood fuel will be affected not only by the density of the firewood, but also by its humidity. That is why the drying process begins with the selection of dry wood for cutting, and ends with a woodpile under a canopy in a specially designated place where it is always dry. In this position, the logs must lie for at least a year to become truly dry and high-quality firewood.
By burning wood, the consumer receives the amount of thermal energy he needs, which is spent on heating the home, hot water supply at home, and cooking. Dry wood will burn as quickly as possible. But with damp ones there will be problems, because part of the energy will be spent on recycling the moisture that is present in the wood. And the more humidity, the more energy will be spent on its evaporation. Combustion efficiency decreases.
Temperature threshold for combustion of wood of various species
Depending on the structure and density of wood, as well as the amount and characteristics of resins, the combustion temperature of firewood, its calorific value, and the properties of the flame depend.
If the wood is porous, it will burn very brightly and intensely, but it will not produce high combustion temperatures - the maximum value is 500 ℃. But denser wood, such as hornbeam, ash or beech, burns at a temperature of about 1000 ℃. The combustion temperature of birch (about 800 ℃), as well as oak and larch (900 ℃) is slightly lower. If we are talking about species such as spruce and pine, then they light up at approximately 620-630 ℃.
What temperature should be in the steam room
After the firewood of the last stack has burned out and the surface has become grayish, when the coals move, the flames are red in color, without blue flashes (carbon dioxide has not yet completely escaped, if blue tongues appear), which means you can close the half-door and firebox, open the valves.
By this time, the stones should already be well heated and the water should boil (the temperature in the steam room should rise to +50-+60°C).
The next step is to ventilate the bathhouse. Open everything that can be opened, rinse the entire steam compartment and stones with boiling water. After ventilation, everything is closed, leaving only a window in the steam compartment. This allows you to heat the bath evenly in an hour and a half. Then close the window after this time. The steam room is ready and you can steam to your heart's content.
Larch
The tree is second only to oak in terms of its thermal characteristics. It’s easier to chop it, and it’s easier to light it, too. Refers to coniferous, resinous species. It does not grow in all forests, but in some places it is found quite often, and in some places it forms larch taiga.
- Fire power: 0.81de.
- Calorific value: 3062 kWh/m³.
- Combustion temperature: 865 °C.
- Burning time: long.
- Flame: smooth, has a noticeable blue tint, sparkles, and can periodically “shoot.” Smokes.
- Coals: have a long smoldering time and good heat.
- Difficulty of lighting: above average. It is somewhat easier to light larch than oak, but you still have to build a small fire before throwing the log into it.
Use of wood based on its heat capacity
When choosing a type of firewood, it is worth considering the ratio of cost and heat capacity of a particular wood. As practice shows, the best option can be considered birch firewood, which has the best balance of these indicators. If you purchase more expensive firewood, the costs will be less effective.
To heat a house with a solid fuel boiler, it is not recommended to use types of wood such as spruce, pine or fir. The fact is that in this case, the combustion temperature of the wood in the boiler will not be high enough, and a lot of soot will accumulate on the chimneys.
Firewood made from alder, aspen, linden and poplar also has low thermal efficiency due to its porous structure. In addition, sometimes during the burning process alder and some other types of firewood shoot out coals. In the case of an open furnace, such micro-explosions can lead to fires.
It is worth noting that no matter what the wood is, if it is damp, it burns worse than dry wood and does not burn completely, leaving a lot of ash.
Dangerous temperature
For comparison, consider a number of studies conducted by scientists in the twentieth century to monitor the effects of regular visits to a steam room heated to extreme values of 110-130 °C.
Professor H. Their in the 80s of the last century put forward an assumption about the connection between high temperatures in Finnish saunas and the occurrence of cancer, which was subsequently confirmed by the results of a large study. After considering a significant number of cases of lung cancer in those who like to steam at 110-130 ° C, it was found that staying in a steam room heated to such temperatures contributes to the formation of this disease.
The fact is that you can only be in such conditions when the air in the room is very dry, and this eliminates the hydrostatic effect of steam on the body. As a result, the blood does not supply the lungs well enough and they become burned due to their inability to adapt to the elevated temperatures to the required extent.
A number of other studies have also discovered that exposure to the dry, highly heated air of a sauna negatively affects sperm production and also leads to digestive problems in children born to mothers who frequently visited such saunas during pregnancy.
Discussion “what is the temperature of the stove in the bath
"or about the temperature around the stove in the steam room - a lot. Unfortunately, they are all carried out on an intuitive level and only a few specialists devote entire studies to this issue using pyrometers, thermometers and other equipment. How does the temperature of a sauna and steam room oven actually differ from the one that the thermometer shows us?
Bath lovers are not builders and, for the most part, coordinate the stove modes with their feelings. The other half of the steamers glance at the thermometer. I decided to find out what the difference is between our perceptions, between the data from the needle of a universal thermometer and what a digital remote temperature meter will show us.
Some temperature measurement data puzzled me, which I wrote about in the conclusions after the video.
By and large, we are not interested in the temperature of the oven, but in the conditions in the steam room. Your own skin is more expensive than the lid of a piece of iron. Therefore, I measured everything where the laser pointer of the device was shooting. I wanted to document the temperature measurements with a diagram, but decided to make a video with remarks
Attention! I used a device with a maximum measurement threshold of 330 degrees (footage in the furnace firebox)
How to simplify the choice of chimney
What is a chimney for fireplaces? This is a set of pipes, one end of which is connected to a heating device, and the other is brought outside. Its installation is a rather complex and labor-intensive process that requires certain knowledge and professionalism. Chimneys can be made of brick, stainless steel, ceramics. Each of these types has its own advantages, disadvantages, as well as installation features. Of course, in order to make the right choice, it is better to seek advice from professionals. However, in order to have some idea about the design of chimneys, we provide below a brief description of the most common types.
Heat transfer when burning wood in a stove
There is a direct relationship between the combustion temperature of wood in a stove and heat transfer - the hotter the flame, the more heat it releases into the room. The amount of thermal energy generated is influenced by various characteristics of the tree. Calculated values can be found in reference literature.
It is worth noting that all standard indicators were calculated under ideal conditions:
- the wood is well dried;
- the furnace firebox is closed;
- oxygen is supplied in clearly dosed portions to support the combustion process.
Naturally, it is impossible to create such conditions in a home oven, so less heat will be released than calculations show. Therefore, the standards will be useful only for determining the general dynamics and comparing characteristics.
Elm
Elm is often found in broad-leaved and mixed forests and can form quite large clusters. It is hard, does not chip easily, but in terms of its heat characteristics it is approximately the same as birch. Just like it, it can burn in its raw form.
- Fire power: 0.77de.
- Calorific value: 2912 kWh/m³.
- Combustion temperature: 864 °C.
- Burning time: long.
- Flame: even, smokes moderately.
- Coals: very reminiscent of birch coals - they smolder for a long time and fry well.
- Lighting difficulty: medium.
What is the combustion process
An isothermal reaction in which a certain amount of thermal energy is released is called combustion. This reaction goes through several successive stages.
In the first stage, the wood is heated by an external fire source to the ignition point. As it heats up to 120-150 ℃, the wood turns into coal, which is capable of self-ignition. Once the temperature reaches 250-350 ℃, flammable gases begin to be released - this process is called pyrolysis. At the same time, smoldering of the top layer of wood occurs, which is accompanied by white or brown smoke - these are mixed pyrolysis gases with water vapor.
At the second stage, as a result of heating, the pyrolysis gases ignite with a light yellow flame. It gradually spreads over the entire area of the wood, continuing to heat the wood.
The next stage is characterized by ignition of the wood. As a rule, for this it should warm up to 450-620 ℃. For wood to ignite, you need an external heat source that is intense enough to rapidly heat the wood and speed up the reaction.
In addition, the rate of firewood ignition is influenced by factors such as:
- craving;
- wood moisture;
- cross-section and shape of firewood, as well as their quantity in one stack;
- wood structure - loose firewood ignites faster than dense wood;
- placement of the tree relative to the air flow - horizontally or vertically.
Let's clarify some points. Since wet wood, when burning, first evaporates excess liquid, it ignites and burns much worse than dry wood. Shape also matters—ribbed and jagged logs ignite more easily and quickly than smooth, round ones.
The draft in the chimney must be sufficient to ensure the flow of oxygen and dissipate thermal energy inside the firebox to all objects located in it, but not to blow out the fire.
The fourth stage of the thermochemical reaction is a stable combustion process, which, after the outbreak of pyrolysis gases, covers all the fuel in the furnace. Combustion goes through two phases - smoldering and burning with flame.
During the smoldering process, the coal formed as a result of pyrolysis burns, while gases are released rather slowly and cannot ignite due to their low concentration. The condensation of gases as they cool produces white smoke. As wood smolders, fresh oxygen gradually penetrates, causing the reaction to further spread to the rest of the fuel. The flame occurs as a result of the combustion of pyrolysis gases, which move vertically towards the outlet.
As long as the required temperature is maintained inside the furnace, oxygen is supplied and there is unburnt fuel, the combustion process continues.
If such conditions are not maintained, then the thermochemical reaction enters the final stage - decay.
Normal temperature of gases leaving the furnace
In order for the water present in hot gases to evaporate better, the temperature of the latter must be increased. On well-heated pipe walls, settled drops of moisture quickly evaporate.
The normal temperature of gases leaving the furnace before exiting into the chimney is 12O...14O°C, when leaving the chimney into the atmosphere - not lower than 100°C.
If the flue gases, when exiting into the chimney, that is, at the view, reach a temperature of about 250 ° C, then condensation does not form, draft improves, the stoves heat up faster, while consuming less fuel.
The temperature of the exhaust gases can be determined using a dry splinter, which is placed across the view hole during combustion. If after 30...40 minutes you remove the splinter and scrape off the sooty surface from it with a knife, you can set the temperature of the gases. The color of the splinter does not change at temperatures up to 150°C. If the torch turns yellow (to the color of a white bread crust), it means that the temperature has reached 200°C; if it turns brown (to the color of a rye bread crust), then the temperature rises to 250°C. A blackened splinter indicates a temperature of 300°C, and when it turns into coal, it means that the temperature reaches 400°C.
Thus, when firing the furnace, the temperature of the gases must be adjusted so that at the viewer it is within 250°C.
You should know that in the summer, condensation either does not form at all or occurs in small quantities. The formation of condensation largely depends on the size of the grate, the correctly raised hearth and the design of the furnace in a Russian stove, the size of the channel, the thickness of the walls, clay and height of the chimney, the temperature of its heating, the humidity of the fuel used, the temperature of the exhaust gases from the chimney and the excess number of chimneys in the oven.
The height of the chimney must be at least 5...6 m, counting from the level of the ash chamber or the hearth of a Russian stove. The thickness of the pipe walls should be half a brick, 20 mm). Thinner pipe walls heat up quickly and cool down quickly, which leads to the formation of condensation. Such pipes must be insulated. Various cracks in the pipe and stove, through which cold air penetrates, also contribute to the cooling of gases and the formation of condensation. When the cross-section of the pipe channel (chimney) is higher than required for a given stove, the flue gases rise through it very slowly and the cold outside air cools them down pipe The smoothness of the chimney walls has a great influence on the draft force, that is, on the exit of flue gases. The smoother they are, the stronger the pull. All roughness in the pipe helps reduce draft and retain soot.
Sometimes, to improve draft in stoves, it is necessary to rearrange the pipes, reducing the size of the chimney, lowering or raising the height of the pipe on the roof. They do this until they get a satisfactory result. In places where the chimney narrows, right angles should be cut off to ensure a smoother transition of gases.
Do-it-yourself stove laying
Weeds
Now is the time to consider alternative types of natural fuel that can be used to fuel a campfire.
Sometimes it happens that there is no dead wood near the camp, but conscience does not allow green trees to be cut (foresters do not allow them), or there is a decent distance to them. Then you have to get out with the help of herbaceous plants. As a rule, if the area is more or less wild and open, such large species of grass as:
- Sagebrush;
- Burdock;
- Thistles, thistles and others like them;
- Blooming Sally;
- Large umbelliferae: hemlock, kupir, angelica, hogweed (including the notorious giant one);
- Cane;
- Rogoz;
- Straw;
- Sunflower stems;
- Fire power: 0.1de.
- Calorific value: 378 kWh/m³.
- Combustion temperature: 800-900 °C.
- Burning time: very short.
- Flame: even, with a characteristic crackling sound. It smokes, the less dry the material, the stronger it is.
- Coals: does not actually form.
- Difficulty of lighting: extremely low, dry weeds are excellent kindling.
If the area is marshy or borders water, then the above list is supplemented by the following plants:
In rural areas, the following options are possible:
The best thing, of course, is thick, non-hollow stems (wormwood, burdock, sunflower). All this nonsense usually dries out in the fall, stands all winter, spring and the first third of summer, then - as the green herbs grow, most of last year's dry stems rot and fall off. However, you can collect a certain amount of such “wood” for a fire at any time of the year.
Dry weeds burn quickly and hotly; they actually do not form coals, because their density is very low. For a full-fledged night fire you will need ten cubic meters and a specially trained farmhand who will constantly throw this thing into the fire. It is also possible to use ingenuity: twist the grass into dense sheaves with twine. It will burn longer.
But in order to light a mini-bonfire, for example, for boiling water, weeds are quite suitable. The only thing you need is a few stones. So that you can lay out a small fireplace and not radiate heat into space in vain, thereby increasing the efficiency of the fire.
Next are the parameters of weeds as fire fuel (during the calculations, straw indicators were used as the initial parameters).
How to determine the combustion temperature in a wood-burning stove
Measuring the combustion temperature of wood in a fireplace can only be done with a pyrometer - no other measuring instruments are suitable for this.
If you do not have such a device, you can visually determine approximate indicators based on the color of the flame. Thus, a low temperature flame has a dark red color. A yellow light indicates that the temperature obtained by increasing the draft is too high, but in this case more heat is immediately evaporated through the chimney. For a stove or fireplace, the most suitable combustion temperature will be one at which the color of the flame will be yellow, such as, for example, dry birch firewood.
Modern stoves and solid fuel boilers, as well as closed fireplaces, are equipped with an air supply control system to adjust heat transfer and combustion intensity.
Do not allow wood to burn too high
There are three wood burning modes: low, high and optimal.
When the mode is reduced, the firewood does not burn completely and produces a lot of soot. If it is higher, you waste firewood: part of the heat flies away through the chimney, since the heat exchanger and the room do not have time to remove it completely. This occurs in two cases: you use too much wood or supply too much air. It is necessary to reduce the volume of the bookmark or draft.
The best option is when the wood burns in the optimal mode: not weakly and not strongly. The easiest way to determine the combustion mode is to use a combustion indicator, which shows the current mode in real time. If the temperature of the flue gases is more than 320 degrees, then the firewood burns at high speed.
The combustion indicator determines the flue gas temperature and combustion mode in real time
Cedar
In mid-latitudes it is rather rare, but in more northern regions it grows everywhere. It has soft wood and cracks well. Cedar wood is good fuel for a fire.
- Fire power: 0.70de.
- Calorific value: 2645 kWh/m³.
- Combustion temperature: ~650 °C.
- Burning time: average.
- Flame: even, may spark. Smokes.
- Coals: quite hot, medium smoldering time.
- Lighting difficulty: easy.
Heat output of wood
In addition to the value of calorific value, that is, the amount of thermal energy released during fuel combustion, there is also the concept of heat output. This is the maximum temperature in a wood-burning stove that the flame can reach when the wood is burning intensely. This indicator also completely depends on the characteristics of the wood.
In particular, if the wood has a loose and porous structure, it burns at fairly low temperatures, producing a light, high flame, and produces fairly little heat. But dense wood, although it flares up much worse, even with a weak and low flame gives a high temperature and a large amount of thermal energy.
Use bottom combustion (if possible)
There are two ways to burn wood: grate (bottom) and hearth (top burning).
Bottom burning is traditional, when air enters the firewood from below and the flame gradually moves upward. With top burning, air is supplied to the wood from above, the fire also burns at the top and gradually falls down.
With hearth burning, the largest logs are laid below, and paper and smaller firewood are placed on top.
Advantages:
- The completeness of combustion of wood increases, due to which they release more heat.
- You reduce the release of volatile substances that pollute the chimney with soot.
- This is a more environmentally friendly way of burning.
How to do it
For hearth burning, the firewood is stacked in a pyramid: the largest logs are placed at the bottom, and the smaller ones at the top. At the very top, wood chips and paper are set on fire.
While the wood chips and paper are burning, the firebox warms up. The flame then begins to move downwards and ignite the main wood. At this point, the combustion temperature and flame intensity are sufficient for the volatile substances that make up the wood to begin to burn. Due to the completeness of combustion, firewood releases more heat, and due to uniform combustion, it burns for a long time and economically.
Video installation of a sandwich chimney with your own hands
A feature of modern sauna stoves is their heating temperature, which can reach 400 degrees. An important indicator of the efficiency of the furnace is instant heating of the body and maximum heat transfer.
The entire heating process is accompanied by the release of infrared radiation, which is distributed on surfaces adjacent to the furnace. Under the influence of high temperatures, the wooden structure of the bathhouse can char or ignite.
This is why it is so important to ensure that wooden surfaces are reliably insulated from the heat of the stove. A protective screen and lining made of fire-resistant materials are suitable for this.
Mini sauna stove
If you choose for a small sauna with a steam room less than 8 m3, then the optimal solution would be a Swedish or Finnish cast iron heater. From the list of models above, the Enchantress M or the Finnish HELO will work perfectly in small steam rooms. Among inexpensive mini-fireboxes, Castor stoves have an excellent reputation, according to reviews.
The main problem with mini-steam rooms is related to their high productivity; the steam is explosive and moist, like from a kettle. Therefore, it is best to choose cast iron fireboxes. They heat up slowly, but produce exceptionally dry and finely dispersed steam, even with weak wood.
Humidity and combustion intensity
If the wood was recently cut down, it contains from 45 to 65% moisture, depending on the time of year and the species. Such damp wood will have a low combustion temperature in the fireplace, since a large amount of energy will be spent on evaporation of water. Consequently, heat transfer from damp wood will be quite low.
There are several ways to achieve optimal temperature in the fireplace and release enough heat energy to warm up:
- Burn twice as much fuel at a time to heat your home or cook food. This approach is fraught with significant material costs and increased accumulation of soot and condensate on the walls of the chimney and in the passages.
- Raw logs are sawn, split into small logs and placed under a shed to dry. As a rule, in 1-1.5 years, firewood loses up to 20% of moisture.
- Firewood can be purchased already well dried. Although they are somewhat more expensive, their heat transfer is much greater.
It is worth noting that the wood of raw felled poplar and some other species is completely unsuitable for use as fuel. It is loose, contains a lot of water, so when burning it produces very little heat.
At the same time, raw birch firewood has a fairly high calorific value. In addition, raw logs made from hornbeam, ash and other dense wood species are suitable for use.
Cast iron wood stoves for saunas
If ten years ago you had to choose more and more from imported models, today the market is literally overflowing with products from manufacturing companies in the CIS countries. Choosing a cast iron stove has become easier and more difficult at the same time, since the designs of the fireboxes, despite their external similarity, have differences, sometimes even very significant ones.
Rainbow stove
The Rainbow line of cast iron fireplace stoves is designed for general heating of a bathhouse and heating a relaxation room. You can purchase models from 4.5 kW, this is “Rainbow JA013S”, to powerful heaters of 13-17 kW. The latter include models “Rainbow JA034B” and “Rainbow JA035B”, equipped with a built-in boiler and heat exchanger to provide the bath with hot water.
At the same time, the efficiency of the Rainbow is 80-82%, which is quite high for a cast-iron wood-burning stove, so the Rainbow models are considered economical, reliable and quite interesting in design.
If you give preference to the Rainbow models, then for a sauna or steam room you can choose the Rainbow PB 11 b sauna stove. The walls are made of structural steel, the weight of the model is only 47 kg with dimensions of 400x770x530 mm. The power is enough to heat a 20 cubic meter steam room. The firebox is remote; due to the short transition, it is suitable for a steam room with any type of insulation.
Another good option, according to reviews, is the Rainbow PB 21b stove. The capabilities of a wood-burning firebox are more than enough to heat a 20 cubic meter bath, the paint does not burn, and cleaning the ash pan is a pleasure. The weight of the Kirov stove is 75 kg, so you can bring it immediately with a supply of firewood using your own transport.
EasyStim ovens
EASYSTEAM brand models have been on the market for more than ten years. The company produces high-quality sauna stoves designed for steam rooms with a volume of 20-60 cubic meters. Almost all models have their own names, consonant with the cities on the Black Sea coast. Almost all of them are lined with soapstone or serpentine tiles. The firebox is made of steel and cast iron.
There is only one line - the “Blast furnace” models are made with an external metal casing. EasyStim - Blast furnace stoves are built according to a combined scheme, therefore they are considered the most durable and suitable for extreme use in bathhouse conditions:
- Steel body with protective coating;
- Firebox made of cast iron with fireclay lining.
The only drawback of EasySteam models is their high price; the cost ranges from 155 to 340 thousand rubles, which is too high for a sauna stove.
Troika stove for a bath
This option is suitable for almost any bathhouse; these are real monsters - the heaviest and largest of all existing wood-burning sauna stoves sold on the domestic market. There is little cast iron in Troika, only individual parts are made from custom cast iron, everything else is made by welding sheets of heat-resistant chrome-alloyed steel, and the wall thickness in the firebox is very large, from 10 to 40 mm.
All Troika models are designed to backfill 250 kg or more of stone. The design of the stove is characterized by a minimum of decorative elements, since installation in a bathhouse requires the mandatory installation of brick screens or lining with chalcopyrite tiles.
To make the process of burning wood in the firebox more manageable, the design provides several systems for spraying water, producing boiling water and controlling chimney valves. In general, a wood-burning stove can be considered successful, but “Troika” is designed mainly for large steam rooms and baths, from 20 cubic meters or more. Price - 70-90 thousand rubles.
Furnaces Svarozhich
The company of the same name produces two lines of models - “Firebird” and “Slavyanka Premium”. Both options are designed for heating the sauna with wood and are made of cast iron. True, this is not Swedish or Finnish cast iron, but ordinary gray, grade SCh 15-30.
Important! The furnace body, ash pan, firebox and return channels are assembled from ready-made cast parts. Unlike Finnish or Swedish models, there is no manual fitting of parts at the joints, but you can adjust them yourself.
Depending on the design of the cast iron stove, the portal for loading firewood is always very large; the door can be made of cast iron or tempered glass with a frame. The quality of the fit of the cast-iron door to the frame clearly requires improvement, so there is always air leakage through the cracks. This must be taken into account when lighting, especially in a frozen bathhouse.
Some models come with a firebox lining
The cast-iron walls of the furnace turn out to be incredibly sensitive to thermal shock, so Svarozhichi require lining with soapstone or installing a brick screen.
Furnace Firebird
The design of the “Fire Bird” of the Svarozhich brand uses both high-quality stainless steel with a chromium content of up to 13% and standard cast iron for the firebox and door. The body is completely lined with a coil, which helps make the design of the stove more attractive and at the same time softens and dissipates the powerful heat flow.
The width and depth are 640 and 770 mm, respectively. The wood-burning firebox, after warming up, produces a power of 15 kW, which is quite enough for a sauna or steam bath with a volume of 35 cubic meters.
Cossack stove
There is no cast iron in the Cossack design; only the grate bars are made of casting. The body and the outer screen, the steam generator box - everything is assembled from 4 mm thick AISI 430 steel. Not the best material, but the main thing is that it does not burn out or deform when the firebox is overloaded with firewood.
Most reviews of “Kazachka” point to three main advantages of the coaxial circuit:
- The steam generator works great; the air in the bathhouse is saturated with not the hottest, but rather hot, finely dispersed steam. It does not condense on the surface of the body and shelves, but at the same time it warms up no worse than a sauna;
- Long firebox length. You can throw long logs;
- Long service life, about 15 thousand hours.
In general, the Cossack heats quickly, so it is suitable for any type of bath. Naturally, subject to high-quality firewood and proper insulation of the walls.
Magnum ovens
A classic version of a heating unit for a bath based on cast iron. The line of Magnum stoves includes at least two dozen models, and all are designed to heat a steam room with wood. All of them were developed on the basis of the advertised Kalita, but in this case the manufacturers managed to take into account most of the shortcomings:
- Reduced the heating inertia of the furnace;
- We improved the efficiency of burning wood, which made the bath heating process more economical.
But the main difference concerns the design. Inside the Magnum there is a cast-iron firebox in a lightweight body with an adjustable tunnel and a glass door on the portal. All this is lined with coil or ceramic tiles, while the exterior of the stove can be decorated in the most unusual way. As in the form of a wooden frame, for example, “Jager”, to the stylish “Gaudi”.
Russian steam oven
In the Kalita family of stoves, it is worth noting the Russian Steam model as one of the most successful solutions, both in terms of design, which is quite strict and at the same time convenient, and in terms of the efficiency of burning wood. Thanks to the special design of the heater, the backfill is located directly above the arch of the firebox, so the stove will warm up quickly enough, even in a frozen winter bath.
The only drawback is the rather high price - 120-130 thousand rubles; for a wood-burning stove to heat a steam room of 18-20 cubic meters it is too expensive.
Vir's furnace
Most enterprises that produce wood-burning fireboxes and heaters periodically rebrand their products. Thus, the well-known model “Shine Clearly” received a slight design update and a new name - Vira.
Structurally, this is a classic version of a stove made of good stainless steel with a built-in steam generator. There is practically no cast iron in it. The stove heats up quickly using wood, but due to the small volume of the heater, it is recommended for small steam rooms.
Furnace Enchantress
The “Enchantress” line of sauna stoves is made of alloy steel with increased resistance to high temperatures; heat-resistant cast iron is present only in the elements of the combustion chamber. The heater next to the wood-burning stove is very hot, the backfill heats up to 400°C and higher. To avoid deformation and “spreading,” the developers made the stove body disproportionately elongated, with a door that opens tightly.
For your information! The younger model “Sorceress M” turned out to be surprisingly successful, with a minimum of shortcomings. Double-chamber wood burning provides extremely high efficiency.
But the main secret of Enchantress M lies in the design of the steam generator. Thanks to the closed design of the heater, the steam is finely dispersed, so the air in the bathhouse warms but does not burn.
Stove Cuirassier
The products of TD Technotrade LLC have always been of high quality, which is confirmed by numerous responses. The design of all Cuirassiers for the bathhouse, and there are more than a dozen of them, is distinguished by high fuel efficiency, a very stylish modern design, a complete absence of cast iron, and most importantly, high build quality.
Instead of cast iron, high-quality alloy steel with a chromium content of up to 18% is used. This ensures high durability of the hottest elements of the firebox. Balanced combustion of wood allows you to heat the heater of the stove to an exorbitant 510°C, without damaging the elements of the chimney or the ceiling of the bathhouse.
In general, this is one of the most modern and successful models of wood-burning stoves for bathhouses of any layout and size.
Breneran sauna stove
The heating unit is built according to a rarely used scheme of coaxial arrangement of a cylindrical firebox and a heating screen. The main parts are made of low-alloy steel with anti-corrosion coating. The grates and the oven door are made of cast iron.
Thanks to the unusual layout, it is possible to ensure rapid heating of the air in the bath precisely due to convection. The huge volume of stones and the built-in cast iron heat exchanger for producing hot water makes it possible to maintain heat in the bathhouse for many hours. The most common models AOT8 are for small steam rooms, and Breneran AOT12 is for saunas up to 30 cubic meters.
Convection oven
This is the most affordable heater option for small steam rooms. The lower price level for the most popular model Konvektika-16 is 15 thousand rubles.
The design of the stove is assembled from stamped parts made of chrome steel, not a drop of cast iron, so the weight of the product is only 46 kg with dimensions of 842x400 mm, with a height of 700 mm. A wood burning stove is not the most economical, but it is easy to maintain and repair.
Bath stove Karelia
Produced by a foundry. This is the case when a sauna stove is cast from molten cast iron with low temperature tempering. The device is assembled from 11 cast iron parts; we pay special attention to the design of the firebox. This is a solid cast product on a cast iron base with a wall thickness of 15 mm.
For installation inside a steam room, it is better to choose “ATB-5 Karelia Classic” with a cast-iron firebox for wood and a stainless steel casing. The model stands out from the entire line of Karelian stoves with its original layout and well-organized wood burning process.
Today, cast iron Karelia for baths is considered one of the best.
Teklar oven
The design of the bath unit is made according to the standard design:
- The body is welded from heat-resistant, scale-resistant steel, only the facade is made of cast iron;
- There are two heaters installed inside, one provides the main stream of steam, the second is used for aromatic mixtures;
- The furnace box must be shielded or lined with bricks.
The size of the firebox allows you to burn wood up to 500 mm long, while the temperature of the heater can reach a record 600°C. It is clear that Teklar will be in demand for saunas or lovers of the Russian steam room, especially if the construction of the bathhouse is located on a summer cottage and is heated only occasionally in winter.
Heat stove standard 500 y
Separately, it is worth mentioning the Dobrostal plant and its sauna stoves. The design of the most popular model Zhara-Standard 500u is shown in the drawing below.
According to its intended purpose, this is a floor-standing sauna stove that runs on wood. Essentially, this is a huge steel firebox in the form of a pipe with a small hood for afterburning pyrolysis gases and a cast iron door. As a result, with a compact size, the power is approximately 30-40% higher than that of stoves of the same class from other manufacturers. The wall thickness is 6 mm, which is enough for steel to provide a service life of 10-15 years.
According to reviews, the sauna stove from the Dobrostal plant is distinguished by a well-thought-out design and safe layout; you can only get burned when putting firewood into the firebox or heating a sauna if you completely neglect the maintenance rules.
Helo sauna stove
The line of Finnish heater-stoves of the HELO brand consists of several models of varying thermal power. The letter index in the name indicates the cubic capacity of the sauna steam room, so when choosing, you can easily select a model without converting it into power. For example, Helo 16 KL SL is designed for a steam bath of 16 cubic meters.
All models are welded from steel, the parts of the grate and ash pan are made of cast iron. Heaters with a capacity of 16-30 cubic meters are produced with metal body screens; more powerful stoves are lined with soapstone or a coil.
According to reviews, “HELO” is quite expensive, but at the same time a very high-quality wood-burning stove for a sauna or Russian bath.
Narvi stove
Finnish products include stoves and fireplaces for baths made of cast iron and stainless steel. A distinctive feature of Finnish models is the use of firewood and briquettes, so the service life of the firebox is simply enormous.
Particularly popular is the famous Kota Luosto with a cylindrical vertical firebox made of alloy steel 10 mm thick. The design ensures that the stove burns wood as efficiently as possible without leaking smoke or soot formation.
Severyanka stove
The developers call the appearance of the device strict, but the design of the heater and firebox is more reminiscent of a homemade homemade product. The design used stainless steel up to 10 mm thick. In general, the box turned out to be heavy - 300 kg without rocky filling, and large, due to the presence of a water tank and two heaters - closed and open.
Important! Another disadvantage is the high price; for a simple model “01” they ask for 58 thousand rubles, many more successful wood-burning fireboxes cost 15-20% less.
Tuymazy stove
Bath heating devices "Tumaizy P-20 GT/T" are produced with a universal type of firebox. The stove in its original version is intended for heating a bathhouse with gas, but it is possible to replace the burners with cast iron grates for the use of firewood.
In general, the design is designed to heat the main room of the bath; it can be used for a steam room or sauna only after modification.
Uralochka stove
The line belongs to the well-known brand “Ermak”. Uralochka is produced in a classic body layout with an open top heater. Can work on gas or wood, after replacing the burner with cast iron grates. All parts, including the firebox and the smoke channel system, are made of stainless steel, so the level of afterburning of pyrolytic gases is low, and accordingly the efficiency does not exceed 50-60%.
The stove is considered universal; it can be used in a city or village bathhouse, so you will have to pay special attention to the quality of the firewood, since such fireboxes always collect a lot of soot and water condensate.
Russian oven
A classic version of a steel stove with a massive heater, no cast iron. A distinctive feature of the Rossiyanka stove is the restive nature of the product; you have to adapt to its work in the bathhouse, and not overload the firebox with firewood.
If you set the heater correctly, you get velvety, finely dispersed steam; if you overheat the water, you get a burst of discharge into the ceiling, which is extremely unsafe for visitors.
Stove "Kamenka 2" for a bath
The model is produced in small series, and more often in single copies for specific bath parameters. The huge round firebox made of a solid steel pipe is designed to accommodate firewood of any length.
The portal is made of a cast iron slab, the heater is made in an artistic design, with elements of hand-forged fittings. Suitable for a bath with a steam room of 18-20 cubic meters.
Sinara stove
The wood-burning heater is produced by the Ural Furnace Equipment Plant. According to reviews, the Zharstal Sinara stove is ideal for a bath. The low price of a wood-burning stove and a well-planned smoke path make Sinara not particularly voracious, but at the same time capable of quickly heating a 100 kg heater without any problems at any air temperature in the bathhouse.
Rowan
It is often found in large quantities in forests, mainly in the form of low undergrowth, however, on the edges and clearings it can grow to significant sizes. It is often found along the banks of rivers, especially taiga ones.
Rowan wood is quite dense, comparable in weight to bird cherry. Nothing is known about the exact calorific characteristics of rowan wood. In our practice, we have repeatedly come across dry mountain ash, which burned approximately like alder, but it did not produce any special coals.
Types of wood burning
Burning hardwood firewood
Birch.
Birch is most likely the main source of firewood in rural areas. Especially where mixed forests grow. Birch wood gives a lot of heat, burns long enough and evenly.
Birch bark (birch bark) serves as an excellent material for starting a fire. The peculiarity of harvesting birch firewood is to split the sprat (the sawn part of the trunk approximately 80 cm in size) into logs (smaller parts), in this case the integrity of the tree bark is broken, which allows the logs to dry out faster.
Birch bark (birch bark) does not allow water to pass through it. Therefore, when cut down, but not sawn or split into pieces, the tree, while in the bark, very quickly rots and turns into dust. This can often be observed in the forest. Trees felled by the wind, seemingly suitable for firewood, but as soon as you poke them with a stick or hit them with an ax, it turns out that only the birch bark remains intact, and the inside of the tree is rotten.
If you find dry birch, feel free to use it for a fire. Birch never pops when burning (burning coals do not fly apart) and is ideal for heating.
Aspen.
Aspens grow on moist soils, near rivers and swamps. In trees older than fifteen years, the core begins to rot. After a few more years, voids and rottenness begin to appear in the center of the wood, in which birds and insects (bees, wasps) like to settle. Be careful when harvesting aspen for firewood; a wasp or bee sting is not very pleasant.
Aspen is a fairly fragile tree, especially the knots, which makes them easy to break. But for the main fire, aspen is of little use. It produces little heat and actively pops (burning coals burst), creating some discomfort and the threat of getting burned and scorching things lying nearby, tents, etc.
Willow.
Willow tree with soft wood. It burns well, but burns out quickly. Thin dry twigs are good for lighting a fire. Willow can also be used for quick fires, when fire is needed for a short time, for example, to boil a container of water. Willow produces very little coal, and the thinner branches, when burned, immediately turn into ash. Willow is not suitable for cooking, barbecuing, or grilling.
Oak.
Oak is a very valuable tree. Using it for firewood is quite blasphemous, but if you come across a fallen or already dead, dry oak tree, you are in luck. Oak gives off a lot of heat, burns for a long time and leaves good coals.
Alder.
It grows more often along river banks. Previously, alder was used to heat stoves for heating the royal apartments. We can say that alder firewood is elite. Burning alder wood produces a fairly hot flame, does not pop, and most importantly does not emit carbon monoxide. Alder chips are used for aromatic smoking. Alder firewood burns for a long time, even though it looks very inconspicuous, but it is one of the most valuable.
Combustion of coniferous wood
Using spruce for firewood is not very convenient. The branches, thin, prickly, quickly burn out, leaving no coals. The wood itself, if damp, burns very reluctantly, and dead wood, usually rotten, produces more smoke rather than fire.
Burning pine wood does not produce much heat, but due to the resin content in the wood, it burns very well; small twigs are well suited for lighting a fire in damp weather. Even old rotten pine firewood does not burn badly. But the main disadvantage of pine firewood is that it burns out very quickly, leaving virtually no coals, immediately turning into ash. More suitable for quick fires.
How does draft in a stove affect combustion?
If an insufficient amount of oxygen enters the furnace firebox, the intensity and temperature of wood combustion decreases, and at the same time its heat transfer decreases. Some people prefer to cover the ash in the stove to extend the burning time of one bookmark, but as a result, the fuel burns with lower efficiency.
If wood is burned in an open fireplace, then oxygen freely enters the firebox. In this case, the draft depends mainly on the characteristics of the chimney.
Under ideal conditions, the formula for a thermochemical reaction looks something like this:
C+2H2+2O2=CO2+2H2O+Q (thermal energy).
This means that when oxygen is available, hydrogen and carbon are burned, resulting in thermal energy, water vapor and carbon dioxide.
For the maximum combustion temperature of dry fuel, about 130% of the oxygen required for combustion must enter the furnace. When the inlet dampers are closed, an excess of carbon monoxide is produced due to a lack of oxygen. Such unburnt carbon evaporates into the chimney, however, the combustion temperature inside the firebox drops and the heat transfer of the fuel is reduced.
Modern solid fuel boilers are often equipped with special heat accumulators. These devices accumulate an excessive amount of thermal energy generated during the combustion process of fuel under conditions of good traction and high efficiency. This way you can save fuel.
In the case of wood-burning stoves, there are not many opportunities to save wood, since they immediately release heat into the air. The stove itself is capable of retaining only a small amount of heat, but an iron stove is not capable of this at all - excess heat from it immediately goes into the chimney.
Thus, by increasing the draft in the furnace, it is possible to achieve an increase in the intensity of fuel combustion and its heat transfer. However, in this case, heat loss increases significantly. If you ensure slow combustion of wood in the stove, then its heat transfer will be less, and the amount of carbon monoxide will be greater.
Please note that the efficiency of the heat generator directly affects the efficiency of wood burning. Thus, a solid fuel boiler boasts 80% efficiency, and a stove – only 40%, and its design and material matter.
Chimney materials
Before purchasing materials, you need to determine the structural features of the chimney.
Brick system
The construction is made of heat-resistant brick using a special dry mixture or oven clay. In addition, you may need material to create a fungus over the pipe.
Metal construction
Before purchasing material for the manufacture of a metal chimney in a bathhouse, it is necessary to draw up its exact diagram with the detailed location of all corners and turns of the pipe.
You will also need 2 iron sheets with holes corresponding to the diameter of the pipe. They are fixed on the ceiling of the bathhouse and on the floor of the attic. You will also need a heat-resistant material that will be secured around the pipe at the point where it exits into the wooden attic.
To create waterproofing around the chimney on the roof, you need to prepare a sealant or a special rubber seal.
Choosing pipes: what to look for
When purchasing iron chimney pipes, you need to decide on their cross-section. Basically, it depends on the power of the stove, but for most bath options this parameter is 15-20 cm. You should not take a diameter that is too large, as it will not retain heat well. And if it’s too small, it won’t create the draft necessary for removing smoke. Whatever it is, the cross-section of the pipe should not be less than the diameter of the outlet pipe of the heating structure.
There are a number of other requirements for the elements of a chimney in a bathhouse:
- The minimum pipe height is 5 m. Neglecting this requirement may result in deterioration of traction. The exact value is calculated depending on the location of the pipe on the roof. In any case, it should rise above the ridge by at least half a meter. The ideal height from the ridge is 1.5 m, but this is not necessary;
- The minimum thickness of the metal used to create the pipe is 1 mm;
- If it is planned that the chimney system will be equipped with a hot water tank, then it must be reflected in a previously drawn up diagram. It is better if the tank is made of stainless steel.
Functions and features of operation of a chimney in a bathhouse
The main purpose of a chimney in a steam room is high-quality and controlled removal of combustion products in order to completely eliminate the accumulation of harmful carbon dioxide and the formation of burning on surfaces. The resulting draft (with air suction into the combustion chamber) maintains a stable operation of the heat generator. By manipulating the flows, the user regulates the heating value of the furnace and fuel consumption. You can heat such a sauna stove for as long as you like, and you can steam all this time.
Features of heat distribution with different methods of connecting the heater to the chimney
The stove in the bathhouse is heated inconsistently. Accordingly, the smoke channel cools down completely between sessions, so the chimney parts experience the strongest repeated thermodynamic loads. The second important factor is operating temperature. Unlike boilers and furnaces used for heating, gases heated to 700 degrees or more are removed here. Direct-flow stoves are often used in the bathhouse; due to the lack of heating shields or water jackets that remove some of the heat, the smoke turns out to be so hot. Therefore, the problem of chimney burnout (the danger of gas contamination and fire) always remains relevant. Chimneys for bathhouse stoves are made from high-quality materials. If these are factory products, they must be approved by the manufacturer for such difficult operating conditions.
Dangerous temperature
For comparison, consider a number of studies conducted by scientists in the twentieth century to monitor the effects of regular visits to a steam room heated to extreme values of 110-130 °C.
Professor H. Their in the 80s of the last century put forward an assumption about the connection between high temperatures in Finnish saunas and the occurrence of cancer, which was subsequently confirmed by the results of a large study. After considering a significant number of cases of lung cancer in those who like to steam at 110-130 ° C, it was found that staying in a steam room heated to such temperatures contributes to the formation of this disease.
The fact is that you can only be in such conditions when the air in the room is very dry, and this eliminates the hydrostatic effect of steam on the body. As a result, the blood does not supply the lungs well enough and they become burned due to their inability to adapt to the elevated temperatures to the required extent.
A number of other studies have also discovered that exposure to the dry, highly heated air of a sauna negatively affects sperm production and also leads to digestive problems in children born to mothers who frequently visited such saunas during pregnancy.
The manufacturing technology of a sauna stove places special demands on the equipment of all its departments, including the chimney. Its design is slightly different from the chimney system of a home stove. It should ensure long-term heat conservation and safety for steam room visitors. Before organizing a chimney in a bathhouse, it is worth knowing several important nuances.
The design of sauna stoves includes 2 types of chimneys:
- Indigenous. They are organized next to the stove, using a special pipe for connection, through which the smoke goes into the main channel. One chimney can be used for 2-3 stoves. The main thing is that its internal diameter has the appropriate parameters, and the pipes from each heating device are located at different heights;
- Systems with a mounted pipe are mounted directly on the stove pipe and discharged through the roof. This chimney option is the most common for sauna stoves.
Classification of chimneys according to installation location includes 2 types:
- External. Their main part is located on the street and fixed to the wall using a bracket. They are not particularly recommended for baths, as they quickly cool down, losing precious heat.
- Internal. These are vertical structures with good traction, located inside the building.
Depending on the material used, chimneys are:
- Brick. A traditional look, characterized by labor-intensive masonry and high requirements for compliance with all parameters. They have a lot of advantages: durability, fire safety, strength, good thermal insulation and heat accumulation. Disadvantages include the roughness and angularity of the inner surface on which soot deposits accumulate;
- A metal chimney is faster to install and costs less. It has a perfectly smooth surface, but weaker heat-retaining characteristics;
- A combined version, including 2 parts: the lower one is made of brick, the upper one is made of a modern sandwich pipe. Allows you to organize neat, small passages that are easier to cover with heat-resistant material.
conclusions
From all of the above, the following conclusions can be drawn:
Dung
Dried (to the point of complete dehydration) cattle manure can also help a tourist out of woodlessness. Cow patties burn very well and take a long time, and they produce quite a bit of heat.
Unfortunately, it was not possible to find the exact parameters of dung as a fuel either in the literature or on the Internet, despite the fact that in many rural areas and agricultural countries it is a traditional method of heating. But they say that in terms of its characteristics, dung roughly corresponds to peat.
Reviews
Semyon Mylshevsky, 73, Bobruisk
You also need to know how to heat the steam room; the heater can be made from a barrel, and the firebox can only be made from cast iron. If you don’t rush to add firewood, then even with a small one you can heat the bathhouse to 60-70°C. I would not buy steel stoves weighing 150-200 kg, they only produce heat and problems with overheating. I bought Kamenka 2 for myself, I won’t describe it, I’ll say one thing - all the design elements have been perfected in practice, nothing superfluous.
Sergey Maltsev, 34, Izhevsk
They praise steel stoves, but I don’t like them. I bought the vaunted Cuirassier, but after three months it burned out on the corner - it couldn’t be properly repaired, it couldn’t be replaced. Thick steel bursts at welding seams, thin steel can burn out in a couple of months. The more tricky channels there are in the firebox, the more often you have to repair it. I inherited a heater from my grandfather, all full of holes, one cast-iron firebox was preserved. I welded a stainless steel cladding and in the end I couldn’t resist, I sold it for 40 thousand, now I regret it. To replace the Cuirassier, I bought a wood-burning Karelia Classic for the bathhouse, so far I like it.
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