Heating country house in winter period due to the correct operation of the boiler or furnace. The absence of a burning smell from smoldering firewood in the firebox confirms the presence of good traction. And the constant aroma of a fire in the house speaks of possible malfunctions furnace equipment.
Why is there no draft in the furnace
When identifying bad smell, it is necessary to eliminate the causes of deterioration in the operation of the exhaust gas system. To detect a factor affecting traction, it is important to consider the nature of the malfunction. If the smell has appeared since the beginning of the operation of the furnace, then the reason may lie in the design or features of the chimney. With the sudden appearance of a smoke aroma, the origin of the defect may be caused by external factors.
Causes related to the oven
The presence of poor draft from the first day of operation of the furnace indicates that the internal structure of the chimney or structure does not allow exhaust gases to be removed from the furnace outside in a natural way. It is no coincidence that since ancient times, in small villages there were craftsmen who knew how to properly lay out the stove and passed on knowledge by inheritance.
REFERENCE! For correct calculation section sizes and lengths, specialists use the unit Pa (Pascal), which shows the rarefaction of air by natural draft, when the height of the chimney changes. Based on the value of this indicator, stove-makers choose the complexity internal structure ovens.
Consider in detail design features that affect traction:
- A complex system of horizontal and vertical passages inside the furnace must have a section and length sufficient for natural draft. The turns of the chimney channel are performed with a large cross section of 10–30%, due to the deceleration of the flow of hot air, in the event of obstacles.
- Incorrectly selected section and height of the chimney can cause a burning smell in the house. The specifics of natural draft gas removal will not allow you to remove a large amount of smoke through a hole of small diameter.
- The cross-sectional shape of the chimney also affects the quality of the exhaust gases. In the corners of rectangular structures, turbulences are formed that slow down the movement of hot air masses.
- The absence of metal liners inside the chimney slows down the movement of smoke inside the system due to surface irregularities.
- The inspection doors for cleaning the furnace channels may not close properly. This worsens draft and allows combustion products to remain in the house.
- An error in the construction of the chimney will lead to a deterioration in the removal of smoke from the furnace. The exhaust pipe located on the side surface of the roof must be higher than the ridge if the distance to it is less than 2 meters.
- The presence of several furnaces in the furnace requires proper separation between them. Incorrect baffle design will result in poor traction.
- The collapse of the brick at the turn of the chimney is often the cause of deterioration in the removal of exhaust gases.
- The connection of the furnace channels with the pipe must not be narrowed or made in a form other than the chimney. Reducing the diameter of the connection will allow a large amount of soot to accumulate and prevent the movement of hot air currents.
IMPORTANT! The laying of the furnace must be carried out by a qualified master. A seam that will burst after drying or cracked brick, may cause poor smoke extraction. It is very difficult to identify such a cause during operation!
The accumulation of soot in the internal cavity of the flue ducts of the furnace and the chimney is a common cause of deterioration in the draft of furnace equipment. What is being done to remedy this shortcoming? Use a brush with a weight and clean the vertical cavities of the chimney. To clean the horizontal channels, special revision doors are used and ash is removed through them.
ATTENTION! When erecting furnace equipment, masonry is performed using clay mortar or mixtures specially designed for fireboxes. The use of a conventional sand and cement based mortar can cause cracking, and subsequently a decrease in efficiency and poor smoke extraction.
Metal chimneys are cleaned with aspen logs. Given the difficulty of ignition, the firebox is first heated using birch or oak, and then aspen is burned. The absence of tar impurities during combustion, with a fully open blower, allows you to remove soot from the channels by burning. This method requires compliance with safety measures due to the increased combustion temperature and the possible appearance of sparks in the chimney.
A similar cleaning is carried out using potato peels or rock salt poured over burning coals. Substances that are released during the combustion of these elements make it possible to remove soot from hard-to-reach places in smoke ducts. The chemical industry produces special powders that, when burned, help clean the chimney.
IMPORTANT! The burning of special mixtures for cleaning outlet channels and pipes allows you to remove a layer of soot up to 5 mm. With a larger amount of soot, the effect is achieved only with the help of mechanical cleaning and removal of ash, using special devices.
External factors of poor traction
The appearance of a burning smell during the operation of the furnace indicates the occurrence of undesirable phenomena that impair the operation of the chimney. These reasons may include the following factors:
How to improve draft in the oven
To avoid the appearance of an unpleasant smell of burning in the room, it is necessary to regularly clean the smoke ducts and pipes. If the house is located in a windy place, a deflector is installed at the end of the pipe, which allows you to stabilize the draft, regardless of gusts of wind.
Chimney insulation can significantly improve smoke extraction. Such work is carried out using a special basalt wool which is not affected by high temperatures.
REFERENCE! Underpressure cold pipe chimney system is 30% lower than heated.
If serious design flaws in the stove are found that require continuous improvement in smoke removal, a complex, but effective method forced removal of exhaust gases using a fan. The use of this method will avoid the appearance of a burning smell, but will need power supply.
The quality of the removal of combustion products of the furnace is due to the correct design and regular maintenance of the chimney system. The construction of furnace equipment with good traction should be performed only by experienced craftsmen. The frequency of maintenance depends on the mode of operation of the furnace (at least 1 time per year). Maintaining the chimney channels in good condition will ensure the cleanliness of the air inside the country house.
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Despite the fact that the 21st century has already come a long time ago, and gas or electric heating has become available to the majority of the population, the Russian stove in some of the houses continues to occupy a central place. It not only heats the house, but is also the "breadwinner" of the family - you can bake bread in it, and cook any dishes. In addition, her couch is a warm sleeping place, and not even for one person. She is also a "folk healer": with the help of Russian oven previously treated many diseases, and also dried herbs for decoctions for the winter. And if suddenly the furnace failed, it became a real disaster.
Possible problems are the appearance of smoke, sluggish combustion and incomplete burning of firewood, insufficient heating. All this indicates the absence of normal traction. And such a deficiency needs to be “treated” immediately, since there is a considerable threat to the health and even life of people. In this case, the question arises as to why there is no draft in the Russian stove. , and what needs to be done to restore its normal functionality as soon as possible.
Russian stove and its design
One of the reasons for insufficient traction may well be weather conditions. This applies to everyone wood stoves, regardless of their design.
It seems implausible now, but the stove for many village families was not only a "nurse", but also a "meteorologist". According to the direction of the smoke column, the burning of coals, the sounds that occur during the fire, experienced owners with a sufficient degree of reliability determined only the weather for several days.
For example, if the atmospheric pressure is low, the stove takes a long time to burn, and the wood burns sluggishly, as the draft in the chimney becomes weaker. In this case, the smoke going into the chimney from the fuel chamber often overflows onto the stove top.
If damp wood is also used in case of poor draft due to low pressure, then acrid smoke can fill the entire room. All these manifestations in the complex indicate that tomorrow there will be rainy and windy weather, and if it is winter outside, then we should expect a blizzard, which is very highly likely bring warmth.
But experienced owners, nevertheless, have always been able to distinguish external phenomena from malfunctions that have arisen in the furnace design itself. There are many other reasons that directly affect the level of traction and, accordingly, the efficiency of this heating facility.
And in order to deal with them, you need to know the internal structure of the furnace, at least schematically. Otherwise, produce repair work it will be difficult.
The structure of the Russian stove is somewhat more complicated than that of many other heating systems. brick structures And, by the way, there is no single, “dogmatic” scheme - even for one master stove-maker, different laid out stoves can differ quite seriously. So, for example, a stove can have an additional firebox located under the main mouth or on the side, or do without it, have a different number of stoves, differ in the size and location of the bench, etc.
In order not to get confused in the departments of the furnace, you need to know their location and names:
So, the design of the Russian stove consists of the following elements and departments:
1 - View or valve blocking the chimney.
2 - Zagnetok - the second wall in front of the entrance to the chamber, located under the arch.
3 - Baking - the surface of the furnace, turned to the wall of the house.
4 - Damper - a removable steel or cast iron door that closes the mouth of the furnace during heating, cooking or baking bread. She is pressed against the walls of the caulk.
5 - The mirror is the front surface of the stove, reflecting heat into the room.
6 - Bed - a sleeping place, heated from the inside, from the arch of the cooking chamber.
7 - Opeche - the lower part of the furnace located immediately on the foundation.
8 - Pechurki - blind holes-niches that allow you to save and distribute heat around the room for a longer time. They often put kitchenware to keep cooked food warm.
9 - Under - the base of the cooking chamber. Usually done with a slight slope towards the mouth.
10 - Prepeche - wooden outbuilding to outside furnace - a mirror. It is used as a ladder for climbing onto a lounger, as well as a shelf for drying shoes.
11 - Arch - this is the ceiling of the cooking chamber laid out in the form of an arch.
12 - The lower part of the chimney.
13 - The mouth is the area of the hearth, located in its front part, which can act as a cooking chamber.
14 - Chelo - the end of the hearth, that is, the lower part of the cooking chamber.
15 - Shestok - protruding forward from common surface walls part of the hearth.
In addition to the departments listed above, the “classic” of the Russian stove is usually the ward space, which is called the podpechek. Stored here necessary inventory, and also the firewood brought from the street is dried up.
The principle of the occurrence of furnace draft
With the correct structure of the furnace and clean channels, draft should be formed naturally, since the necessary conditions for its occurrence are laid down in the very design of the heating structure.
The main thing in this process is the chimney, through which smoke is removed from a functioning furnace. During the combustion of the fuel mass, an area of discharged air is formed, due to the difference in the height of the location of the combustion chamber, flue ducts and the mouth (outlet) of the chimney. Thus, an exhaust force arises, which contributes to the removal of combustion gases.
Another significant factor is the temperature difference in the combustion chamber and in the atmosphere, since the heated air tends upward to lower temperatures.
It would seem that the principle of thrust formation is simple, however, there are enough points that can complicate the process of removing combustion products.
Often, traction is absent under the influence of external factors. But it may also depend on incorrectly calculated parameters of some departments. furnace design. In any case, if such a problem arose, first of all it is necessary to find its cause, and then look for ways to eliminate it.
Reasons for the lack of draft in the furnace
As mentioned above, there may be no draft in the Russian stove due to different reasons. It is very important to understand correctly - when the phenomenon of traction insufficiency arose: during the first tests of the heating facility, or during its operation, despite the fact that the furnace was previously heated quite normally ..
No draft when testing a new furnace
Before testing a newly built furnace, it must be dried. In a wet structure, not only can there be no traction, but the solution can also crack, and sometimes even the brickwork itself can deform and crack.
The clay mass used as a solution should be dried at natural temperatures, without sharp jumps upwards or, conversely, downwards.
Drying the oven in natural conditions takes place within 5÷7 days, while all doors and valves must be open. At this first stage of drying, it is allowed to speed up the process with the help of a powerful incandescent lamp placed in the combustion chamber, for example, 200 W. It must be kept on throughout the drying of the oven. The lamp will not give strong heat, it will slightly heat the walls and create an upward flow warm air.
Another option that is acceptable to speed up the process of evaporation of moisture is to install a fan heater or infrared heater directed to the open door of the combustion chamber.
For these purposes, the stove is heated three to four times a day, with an approximate duration of one and a half hours. In this case, paper, thin wood chips or brushwood can be used, in the amount of two to three kilograms per bookmark. This fuel will not give a lot of heat, but will speed up the drying of the masonry.
If, during the second stage of drying with heating, smoke has entered the room, this can be caused by several reasons:
- Violation of the scheme for the construction of the chimney or its channels. For example, if the length of horizontally located channels is more than the allowable dimensions of 1500 ÷ 2000 mm. Another incorrect option is when the gas channels are not wide enough for throughput. The smoke does not have time to go into the chimney, it has nowhere to go, and it begins to seep into the room. The other side of the coin is that when the channels are too wide, too much traction is created, so the efficiency of the stove is significantly reduced (and it is not very high for a Russian classic stove anyway).
In order for the process to be balanced, the laying of the furnace must be carried out exclusively according to the drawing developed and tested in practice. In it, the parameters of the channels are calculated depending on the volume of the main hearth, as well as on the purpose of the furnace and the presence of additional combustion chambers.
- Incorrectly equipped exit to the chimney well. The dimensions of this section of the furnace must exceed the cross section of the gas channel, or, in extreme cases, they must be the same. In addition, the upper edge of the exit to the well must be located above the upper edge of the combustion chamber door. Otherwise, when this door is opened, smoke will enter the room.
When laying the furnace, if for some reason it is not possible to equip the outlet hole higher, then along rear wall furnace, an additional partition is built, forming a channel, which is connected to the exit to the chimney. This space will also become an obstacle for unburned solid particles of wood combustion products to enter the chimney.
- If the chimney is lined with a metal pipe, its diameter must be the same throughout. Thus, a large amount of soot deposits will not accumulate at the pipe junctions, which can also interfere with the creation of normal traction.
- The blower hole, located in the lower part of the furnace under the firebox or under the hearth, must have certain parameters, which are determined by the size of the furnace departments. Otherwise, the air flow will not be enough to create normal traction.
- Not mounted on pipe head protective cap, which prevents moisture from precipitation, as well as dust and other debris from entering the chimney opening. This factor can also cause reverse thrust.
- During the construction of the furnace, the masonry joints between the bricks or around the metal elements were not sufficiently sealed. That is, outside air enters the combustion chamber, and the smoke has the opportunity to find a way out in addition to the chimney pipe.
- The chimney is not high enough in relation to the roof ridge. In this regard, turbulence may occur in the chimney, creating obstacles to the formation of normal draft. As you can see in the above diagram, the height of the chimney depends on the distance (in horizontal projection) between the ridge and the location of the pipe:
- when removing the pipe from the ridge up to 1500 mm, the pipe must rise above the level of the ridge by at least 500 mm.
- if the pipe is removed from the ridge at a distance of 1500 to 3000 mm, then coincidence in height with the line of the ridge is allowed;
- if the distance between the ridge and the pipe is more than 3000 mm, the pipe head must be located not lower than the imaginary line drawn through the point of the ridge at an angle of 10 ° to the horizon.
- Wrong about arranged ventilation room or even its absence can also lead to back draft. If it is impossible to create a normal system supply ventilation, then it is necessary to create an air flow for the duration of the furnace by opening vents or doors. But here, too, there can be negative nuances. So, a violation of normal traction can be observed in the following cases:
- windows are open in the room, which are located much higher than the furnace door;
- when there are strong drafts in the room, which also disrupt normal movement flue gases along the chimney channels;
- if there is a strong wind outside.
- If the Russian stove has several departments, that is, there are several combustion chambers in its design. The partition separating them may be built incorrectly, or the cross section of the chimney is insufficient, so it has a low throughput- these two factors also contribute to the reduction of traction.
In order to prevent smoke in the room when testing the stove, the draft can be checked without kindling firewood in the firebox. It is enough to bring a burning sheet of paper or a match to the open door and follow the direction of the flame. If the flame is directed towards the firebox, then there is a draft, but if it is towards the room, then it is necessary to look for the reason for its absence.
Lack of draft in the old furnace
If the thrust has disappeared in a previously well-functioning Russian stove, then the reasons for this phenomenon may differ significantly from those listed above.
So, if the stove was working normally, but once, when it was kindled, it turned out that the smoke was ashamed to enter the room, then the following problems could be the reason for this.
- During the period of operation, the chimney was depressurized, that is, cracks formed in the masonry under the influence of atmospheric factors and temperature changes. It is such damage that can weaken the draft in a furnace that has long been put into operation.
In this case, there is another serious danger - these are sparks and particles of burning soot, which can penetrate through the holes formed in the walls of the chimney. Scattering, sparks can get on combustible materials both on the roof of the house and on neighboring buildings, which can lead to a fire.
- Narrowing of the internal space of the chimney due to blockages caused by soot deposits. In this case, the problem can be solved only by cleaning the internal surfaces of the chimney, as well as the channels and the combustion chamber.
Even if during the period of operation, preventive cleaning of the smoke exhaust system is carried out, then, as a rule, easily accessible straight sections of the structure are affected first. However, the accumulation of soot deposits occurs at the bends or bends of the channels, where the smoke changes its direction.
Due to an insufficiently well-cleaned chimney, draft will definitely decrease. If it is not possible to clean the chimney yourself, then you should invite an experienced specialist to do this work.
If you decide to clean it yourself, then the following methods are used for this purpose:
- Starch or dried potato peelings that are burned in the combustion chamber. They are able to partially clean the pipe, they are also used for preventive purposes.
- The vertical sections of the chimney system are cleaned with a special brush, to which a heavy object is tied, capable of pulling a light-weight brush. She will collect soot deposits from the walls, some of which will fall into horizontal channels or a firebox.
- From horizontal channels, crumbling soot is raked out through cleaning windows or holes blocked with bricks, which are temporarily removed.
- You can also clean the chimney with well-dried aspen firewood, which has a low resin content, which causes soot. This method has long been used by the owners of furnaces. When burning aspen wood, the blower must be completely open so that the smoke freely goes into the chimney, even if there is a blockage.
- Today on sale you can find special powders for removing soot deposits. They are designed to be burned in a firebox along with firewood. After burning through such a bookmark, the chimney remains clean, it remains only to clean the firebox from ash.
Using cleaning methods using aspen firewood or starch, safety rules must be observed, as soot will begin to burn directly in the pipe. The draft becomes more intense when the space is freed from soot, while the pipe heats up very much, and sparks begin to break out. Therefore, most often such methods are used in cases where the thickness of plaque on the walls is about 3 mm. If the chimney is thoroughly clogged with soot, then you should first apply mechanical way cleaning, and then burn one of the above substances in the furnace.
- Long pause in the operation of the furnace. If the stove is not used during the summer period, moisture may accumulate inside the channels, which, evaporating, forms inner space pipes air locks(dense layers of air). They prevent the free exit of flue gases to the outside. However, this problem should resolve itself after a few “sessions” of the firebox. Therefore, it is necessary to prepare the stove for the heating season in advance, until the cold sets in, and the room can be ventilated without compromising comfort. To avoid such problems, it is best to choose cool days in summer for preventive purposes and heat the stove with two to three kilograms of firewood.
- Violation of the tightness of the masonry of the furnace itself. This can happen when a poorly prepared foundation is deformed, due to too wide joints in the masonry, improperly selected ingredients or the consistency of the mortar. All of these factors can lead to cracks that reduce traction. In addition, carbon monoxide gases can penetrate into the room or under the roof through the gaps formed, which is extremely dangerous, since there is a possibility of a fire. Carbon monoxide in itself is extremely dangerous for human health and life - it causes extensive toxic damage to the body.
Ways to increase traction in a Russian stove
When preventive measures are taken to clean the channels and the chimney from soot deposits, revisions for the integrity of the structure will be made, you can use some methods to optimize traction. However, this should only be done if the draft remains weak after cleaning. It is possible to increase traction without resorting to the help of specialists or complex electrically dependent devices, as well as using the latter.
- Deflector or weather vane. This fixture is a modified version of the cap that was previously used for installation on chimneys. The deflector rationally uses the wind to create an exhaust draft of the furnace.
- The ventilation turbine during its operation uses the energy of wind flows, creating the necessary air rarefaction in the chimney shaft. This increases the thrust, which intensively removes the products of combustion, and the effect of reverse thrust is eliminated. This device also protects the mouth of the pipe from precipitation and various garbage.
The deflector is a draft regulator in the chimney.
- The draft regulator is another version of the deflector, which not only normalizes the intensity of the removal of combustion products, but also serves as protection for the chimney from water and debris. In the lower part of this device, resembling an umbrella, there is a zone of free space for the passage of air flows. There are models of regulators equipped with special sensors that can not only increase traction, but also adjust its intensity. For example, with poor draft of a Russian stove, the outgoing gases, acting on the heat sensor, will contribute to its strengthening, respectively, will increase the efficiency of the stove. When the combustion is weakened, the sensor will reduce the intensity of thrust.
- Electric smoke fan. Installing this device on a chimney, of course, will cost much more. However, it will absolutely provide normal traction, regardless of the weather and atmospheric pressure. The device will draw out almost all combustion products, so clogging the chimney is unlikely. Such fans have enough high power. Therefore, some models are installed in complex structures multilevel chimneys and ventilation systems multi-storey buildings.
Furnace elements and the need for their regular maintenance
In order for the furnace to function normally, and the draft is always optimal, you need to know how to properly carry out preventive maintenance. Therefore, this section will describe in detail the areas of the furnace that should be monitored and cleaned regularly.
On the diagram of the Russian stove above, the departments that require regular revision and cleaning are numbered.
1 - Ash pan. This section of the stove is usually cleaned every time before the start of the next laying of firewood and the firebox of the stove.
2 - Blower. This chamber is periodically cleaned of fly ash. The blower regulates the flow of air into the fuel chamber. It should be noted here that in most designs of stoves, the ash pan is combined with a blower, and in this case, cleaning, of course, is done before each use of the stove.
3 - Blower door. When melting the stove, the blower door must be kept open, and in the process of burning fuel, it is left ajar. Thanks to this adjustment, a draft of the required intensity is created in the smoke extraction system.
4 - Grate (grate). This structural element is cleaned before putting fuel into the fuel chamber.
5 - The fuel chamber must be inspected before each fuel filling. If soot appears on the walls of the firebox, it should be removed periodically.
6 - The mouth of the fuel chamber (loading tunnel) after fuel filling must be free. Therefore, when the firebox is filled with firewood from the tunnel, all elements that prevent the door from closing tightly should be removed.
7 - The door of the fuel chamber opens only when loading fuel, as well as during maintenance work.
8 - The mouth of the firebox (hailo) serves to divert combustion products into the chimney channels. This zone is cleaned simultaneously with the combustion chamber.
9 - Vertical channels, at the same time are the heat storage area of the furnace. This area can be maintained in a normal state by periodically burning starch or chemical cleaning powder in an oven. However, the major annual cleaning of this department, as well as the chimney pipes, is most often carried out by a chimney sweep.
10 - The front wall of the furnace (brow). On the forehead, above the firebox door, by about 600 mm, it is determined by touch whether the operating mode (stroke) of the furnace is sufficiently optimal.
11 - View. When the oven is fired up and it is in operation, it opens completely. When the fuel burns out, it can be slightly covered to keep the heat. The view closes only after the fuel has completely burned out, when the emission of carbon monoxide is guaranteed to stop.
12 - The damper is designed to adjust the draft in the chimney. This element, in combination with the blower door, establishes the optimal operation of the furnace.
13 - The cleaning door is used to discharge the air in the chimney when starting a stove that has not been heated for a long time, which has stood in the cold, as well as for additional control over the draft force.
14 - The chimney shaft is the main channel that removes the combustion products of the fuel. It is its integrity and regular cleaning that should be given special attention.
15 - The woodcutter or the chamber for drying firewood is not connected with any of the departments of the furnace, into which open fire or combustion products of fuel enter. The woodcutter's space warms up well so that the firewood prepared for the next bookmarks gets rid of excess moisture accumulated during outdoor storage. In the Russian stove, this section is usually located in the lower part of the stove chest under the hearth.
The presented design may differ somewhat from the structure of the Russian stove, but the main draft-regulating elements for all stoves are identical. The Russian stove may differ in the design of the heat-storing sections, since they are a common space located between the arch of the main fuel chamber and the surface of the lounger.
* * * * * * *
Now, knowing how the furnace is arranged, and in which departments the problem of insufficient traction may occur, you can solve it using various cleaning methods. In order not to encounter a decrease in efficiency again, you should regularly audit the furnace and carry out preventive measures. And spare no expense to call an experienced specialist who will tell you what nuances of operating a particular model should be paid special attention to.
The causes of poor traction can be very different. What is draft in the furnace. Thrust is an aerodynamic phenomenon, which is determined by the direction of air movement, due to the pressure difference in the guide exhaust structures inside and outside. That is, in our case, the pressure difference inside the furnace and outside.
Collapse
Causes in the oven
Furnace draft depends on many factors, ranging from constructive solutions, the quality of masonry to meteorological factors and the need for periodic maintenance of the entire kiln system. Let's take a closer look at why bad traction in the furnace, what could be the reasons for the design features:
- chimney design,
- pipe size,
- collapse of brick in the chimney,
- chimney clogged with soot.
Chimney design
The most simple design chimney - straight. Exit outside the premises occurs directly with a pipe. This can be seen in the example of simple "bourgeois" in temporary premises, tourist stoves and in the case of fireplaces.
Straight design provides the most better traction, it is she who is used in the open firebox of fireplaces and in temporary stoves. The draft in such a pipe near the furnace is almost ideal and depends to a lesser extent on external factors.
But in systems furnace heating dwellings chimney is arranged through a heater. The purpose of such a furnace is to heat the room, to keep heat as long as possible.
Pipe size
How to increase draft in the furnace if the chimney design is with a heater? All things being equal, the higher the pipe, the better traction. But not everything is so simple. Winds begin to affect a pipe that is too high, and when too high pipe traction may be excessive. Excessive draft leads to faster combustion of the fuel and an increase in the combustion temperature in the furnace, which is unfavorable for the masonry.
At the same time, rapid combustion does not have time to heat the entire heater array.
The optimal height of the chimney is about 5 meters or slightly above the roof ridge in order to avoid the effects of air turbulence from it.
By the way, according to fire regulations, the length of the chimney above the roof ridge allows you to place the exit at any distance from it. Whereas, more low pipe should be located from the edge of the roof and the ridge at a certain distance. These reasons must be foreseen even when laying the stove; they cannot be corrected during operation.
brick collapse
Causes of poor draft, which depend on the care of the stove and which can be eliminated as they occur, are temporary. The draft of the correct chimney of your stove can also depend on time factors. One of these is the collapse of the brick inside the chimney. This happens, most often, due to poor-quality material, but it may also be due to the reason indicated above.
Burnout of bricks at a high combustion temperature of the fuel is one of the main causes of premature breakdowns. Pieces of cracked brick clog the chimney at the points of its turn and interfere with the free passage of gases. Clogging with foreign objects and soot is the main temporary problem in the operation of any furnace.
In this situation, you will have to redo the chimney.
Chimney clogged with soot
There are several reasons for this trouble. First of all, the design of the chimney affects the possibility of clogging. The more turns, the more opportunities for soot to settle from combustion products.
The more “wells” in the design of the heater, the more often it is necessary to clean the chimney and pipe due to a decrease in the rate of passage of smoke, a decrease in traction. AT this case it turns out a vicious circle - soot reduces traction, with a decrease in traction, soot is deposited even more intensively.
Lots of soot
How to improve traction with such a problem in the furnace without cleaning in the standard way?
There are several methods - during the day, heat the stove with dry wood with a low resin content, briefly create a high burning rate when burning easily combustible materials. Often the deposition of soot also contributes to the formation of frost on the inner surface of the pipe.
To prevent this, if you leave the house for a long time, you need to close the pipe damper in time, which will prevent the contact of hot air with moisture. environment. When the chimney is running and clogged with foreign objects, cleaning is indispensable.
Elimination of these causes is carried out:
External factors
Why is there bad draft in the stove, if it is arranged correctly, and the chimneys have been recently cleaned? In addition to these reasons, stove draft depends on external environmental factors and weather.
The most common of them:
- improperly arranged ventilation in the house,
- fluctuations in temperature and humidity outside,
- wind and other climatic factors.
Let's take a closer look at what we have to do in these cases.
Violation of ventilation
tributary fresh air contributes to the establishment of the desired pressure drop in the furnace and chimney. If the house is cold and the stove has not been heated for a long time, this difference is minimal. And the lack of air in the combustion room can create a temporary vacuum in the room and provoke back draft. On the other hand, excessive drafts are also unfavorable, since vortex air flows can disrupt the air flow into the furnace, knocking down the correct draft.
This is often observed in the summer, and also if the windows are above the level of the firebox, in this case it will be easier for hot air to change direction towards the hood through the window. You need to be especially careful with gas stoves, there is a danger not only of changing the direction of the draft, but also of extinguishing the burner and filling the room with gas.
Before the first attempts to kindle the stove, it is necessary to check not only the draft in the furnace, but also the air movement in the room, and when using the stove, constantly monitor ventilation. This is also necessary to prevent carbon monoxide poisoning.
Strong wind
Strong wind gusts can temporarily obstruct the exit of smoke from chimney. With such a churning of the hot gas flow, the thrust can work in the opposite direction. This happens more often with chimneys connected directly to the firebox without passing heating wells.
Worsening the wind situation and the horizontal position of the pipe outlet, which is often used in utility rooms the lower floors of the house (exit through the wall).
Protection from the winds prevailing in the area is arranged with the help of pipe caps, "chimneys" or "flue vanes". They also prevent getting wet in rain and snow. Humidity outside air- Another obstacle to good traction.
Installing a chimney will solve the problem
High humidity
This factor is indirect, but no less unpleasant. High humidity of the external air can be formed due to low atmospheric pressure, which already reduces traction. The increased density of the humid surrounding atmosphere reduces the rarefaction and impairs smoke movement.
It is easy to see that in the rain and snow, the smoke reluctantly leaves the chimney, spreads along the roof, and with every gust of wind it escapes through the stove door into the room. And vice versa, in clear dry weather, the draft is excellent and the smoke is worth pillars in the sky. Finally, at high humidity in winter, a dense coating of frost forms in the pipe, which sharply reduces the cross section and prevents the normal release of gases.
In this situation, you will often have to clean the chimney.
Other reasons
Many private causes can affect the intensity of stove draft, in addition to those discussed above. Such random reasons may even include heating the roof plane in the sun and low temperatures in the house or random wind eddies that do not allow the stove to flare up. There are several proven ways to remove obstructions to the firebox. home stove. If there is a back draft in the furnace for unknown reasons, what should I do?
- Ventilate the room, which will allow and equalize the temperature and pressure inside and outside.
- Check if the damper is open, if there is a snow cap on the pipe and if the firebox is clean.
- One of the simple ways is to create a vacuum in the pipe by simply burning a large number paper in the chimney at the outlet.
- Use fast-igniting materials in the firebox to quickly increase the temperature difference (not recommended to use flammable liquids).
In such cases, you will have to suffer a little until the draft is established, and then ventilate the room.
Conclusion
The main thing in the device of the furnace is the correct calculation of the parameters of the furnace and chimney. Seek help from experts. Laying stoves is a very difficult task, and it is no coincidence that the skill of a stove maker has been highly valued at all times. The second aspect of this problem is to use only high-quality materials that can withstand high temperatures and do not collapse.
Periodic maintenance of the chimney and firebox will eliminate not only draft problems, but also provide fire safety. Watch for changes in the weather, use all stove settings correctly, and use quality fuel. When these simple conditions are met, your home will always be warm and cozy.
←Previous article Next article →Our grandparents also knew about the concept of reverse thrust. In almost every private house with a stove in winter, one could observe how men smoke near the firebox, and all the smoke goes into the stove, and not into the house. With the advent of modern gas heating equipment the problem has not disappeared. Very often there is a reverse draft in the chimney of a gas boiler or column. In order for the heater not to deteriorate and function properly, it is necessary to familiarize yourself with the nature of this phenomenon.
The occurrence of reverse thrust
Draft is the directional movement of air through a chimney or other channel. From the school bench, we know that such a movement is caused by a temperature difference or atmospheric pressure drops, since the density of warm air is less than cold air, and a phenomenon such as draft arises, forcing air currents to move.
If such a process is carried out without the help additional devices or appliances, it is called natural draft. When the air flows turn around and begin to move in the opposite direction, a reverse draft occurs in the chimney. What to do in such situations depends on many conditions. First of all, it should be understood that the rarefaction occurs due to the presence of sources of natural ventilation in the room. To avoid smoke in the room, it is useful to know exactly how much air leaves the room, because the same amount should enter it. With proper operation of the draft, it can be easily controlled, reducing heating costs and improving the quality of heating.
Interestingly, even with correct device chimney in a private house, a short-term occurrence of reverse draft, called tipping over, may occur. The reasons are most often adverse weather conditions, and the effect does not last long.
Thrust Definition
At the beginning of each heating season Before starting the boiler or furnace, check whether there is a backdraft in the chimney. What to do for this? Of course, there are special devices for measuring thrust, but they are very expensive and are available only from specialists.
From the experience of generations, it is known that the draft in the furnace should be checked with the help of a flame. To do this, a match is lit and brought to the firebox. If the flame draws into the furnace, then the draft is good, and you can begin to melt the room. When the fire is not moving, there is no draft at all, and if the flame blows into the room, then the draft in the chimney is reversed. What to do when starting gas boilers? open fire it cannot be used. You should check where the smoke is drawn by tilting a thin strip of paper.
The color of the burning flame can also tell about the amount of thrust in the furnace. Ideally, it should be golden. If the color is red, then the fire does not have enough oxygen for normal combustion, and if a rumble occurs during the firebox, one can judge about excessive exhaust.
This process is influenced by a large number of factors. The main one is the incorrect design of the chimney at the construction stage. In order not to face the problem of insufficient or incorrect traction in the future, it is necessary to correctly calculate in advance:
- chimney section size;
- its location;
- material of manufacture;
- form;
- pipe height;
- the presence of additional devices that increase traction.
The number of people or devices consuming oxygen in the room also affects the quality of air movement. The latter include heaters, irons, cookers etc. Important for correct operation and regular ventilation.
A person can control all this on his own, therefore, the presence of reverse draft in the chimney depends only on him. What to do if the weather influences traction? It is impossible to control them, but it is quite possible to resist them.
The main reasons for adjusting air flows
From the foregoing, it is clear that rarefaction of air is only a consequence of weather phenomena or human actions, therefore, the elimination of reverse draft in the chimney begins with exact definition the reasons for its occurrence. The main one is the wrong design of the whole heating system and fume extraction. In this matter, it is important to pay attention not only to calculations, but also to the selection of material. For the chimney of the furnace, it is better to use ceramics or bricks, but for boilers or geysers will be ideal metal pipes. In addition, the cause of reverse draft in the chimney of the furnace may be hidden:
- in the clogging of the chimney;
- in the presence of narrow sections in the smoke passage channel;
- the location of the chimney in the channel "wind backwater";
- in violation of natural ventilation;
- under adverse weather conditions.
By the way, availability depends on the weather outside. right flows air, even if all the rules for arranging the chimney are observed. Thrust tipping occurs especially often when strong wind, high humidity or high temperature outside the window. This is true when using a gas column in the summer.
In any case, upon occurrence similar phenomenon It will not be superfluous to inspect the smoke exhaust routes and make sure they are in good condition.
Structural issues
The device of a chimney in a private house always assumes the presence of a straight chimney, located strictly vertically. This technique is considered to be the most effective, because if there are bends, slopes or horizontal pipes draft will deteriorate proportionally, and slowly passing smoke will accumulate a large amount of soot on the inner surface of the ducts.
You should also pay attention to the location of the chimney against the outer wall. This is very rare, since it involves slow heating of the smoke paths and a large accumulation of condensate during cooling, which in hard frost freezes easily. In combination, these phenomena are conducive to the frequent occurrence of reverse thrust.
The least resistance to move the smoke in the right direction occurs only if there is a round pipe in the design. It is considered ideal for arranging the chimney of any heating appliance.
Correct installation
It is important to know that, depending on the type of heater being installed, the installation standards and connection rules will also change. Only with the right calculation can you get efficient work heating system without the occurrence of rarefied air.
This is largely affected by the combustion temperature of the fuel. The higher it is, the stronger the thrust, but at the same time, the need to obtain a volume of air sufficient for combustion will also increase proportionally. If ventilation does not provide it, then the stove or boiler will begin to take it out of the room, thereby provoking the occurrence of reverse thrust.
To avoid this phenomenon, when operating the stove, it is necessary to use a chimney tooth in its design. The device is a small ledge between the firebox itself and the smoke box. Reverse draft in the chimney of the gas column is eliminated by installing supply valve, but his work does not always help to really solve the problem.
Materials for arranging a chimney
To avoid further problems with draft in the heater, you should choose the right material in advance for arranging its chimney. Absolutely for all gas boilers, columns and other devices, metal chimneys should be installed. Such material contributes to rapid heating, but also the same rapid cooling.
For heating sources in the house that use for their work solid fuel, the ideal chimney lining would be brick or ceramic. Such materials contribute to greater heating, but at the same time retain heat better.
When arranging smoke exhaust routes, it is important to pay attention to the smoothness of the surface. The smoother it is, the less likely the rapid accumulation of soot and the need to clean the chimneys.
Cleanliness check
In order to prevent back draft during the heating season, the chimneys should be regularly checked for cleanliness even before the need to regularly use the heaters. Blockages can be caused by birds flying into the chimney, large accumulations of soot, or peeling plaster from the inside of the chimney paths. You can check the cleanliness by looking into the pipe from the roof or through the cleaning hatch, but with the help of a mirror.
If there are contaminants in the pipe, you can clean them with the help of special brushes and even chemicals that are sold everywhere today. In order to delay cleaning the chimney as far as possible, it is recommended to use one of the preventive tips that have been passed down through the generations.
The first says that once every 10-12 furnaces, aluminum cans should be burned in the furnace. It is important that the combustion temperature is such that the cans are completely burned out in 5 minutes. It is also advised, if there is a large amount of soot in the chimney, to throw approximately half a bucket of peeled and chopped potatoes into the furnace while burning. The starch released during the combustion of the product will be able to soften the plaque, and the soot itself will crumble from the surface of the chimney. You can periodically burn rock salt in the furnace, this will also delay cleaning.
Chimney height
The presence of draft in it largely depends on the height of the pipe that removes smoke from the heater. The chimney should be approximately 5 meters high, but not lower than the ventilation duct. Its top point should be 0.5 meters above the roof ridge and approximately 1.5 meters away from it. In this case, the presence of trees or other buildings around the house that can impair traction should be taken into account.
natural process
In a private house, the presence of natural ventilation facilitates the flow of fresh air into the room. In apartments, especially after repairs and replacement of windows, the room often becomes airtight, and in the absence of air intake, a vacuum is created. In order for the situation to remain normal, during the repair, you should also think about installing additional ventilation valves. The usual kitchen hood or air conditioner.
Reverse thrust elimination
So, how to get rid of reverse draft in the chimney? In most cases, this problem can be solved independently. To eliminate a short-term lack of draft in the furnace firebox, you should burn a couple of newspapers to warm the air in the pipe, but most often the chimneys just need to be cleaned. If the draft disappeared after the repair or did not appear at all, then an error in the calculations was probably made, and additional devices would need to be installed in the room.
As such, smoke exhausters, chimney weathercocks and fans or deflectors can act. It may be necessary to increase the length of the pipe. You can also briefly open the window to ventilate and let fresh air into the room or insulate the chimney if its parts are located on the outer wall.
The lack of traction is dangerous not only for the functioning of the devices, but also for the health of the residents themselves, therefore, in such situations, use heating appliances prohibited until the problem is fixed.
