There is no draft in the chimney. Back draft in the chimney: what to do and how to fix the situation

So what exactly is cravings? This, if we speak scientific language, aerodynamic directional air flow of flue gases in any exhaust structure. This phenomenon occurs due to the fact that the wind is all about the difference in air pressure inside the furnace and outside, air masses always tend to where the resistance is least. And speaking in simple words, reverse draft in the chimney is when the air flow of gases leaves the burning wood not to the chimney to the outside, but back to the room. There is also the term "thrust rollover" - and this is when the direction of movement of the air flow on a short time changes to the opposite.

You will be surprised, but tall buildings or trees nearby, and if the height of the chimney is lower than the ridge of the roof, can lead to difficulties with draft. There are many factors, so let's figure out together why you have such a problem and how to improve chimney draft once and for all.

How do you know if there is reverse thrust?

It is easy to notice the first signs of problematic cravings - if the wood in your stove is burning with large quantity smoke, the glass on the door instantly smokes and when the door is opened, the smoke will immediately rush into the rest room - the draft is too weak. And if you do not figure out how to increase the draft in the chimney, it will soon become not only bad, but also reverse.

You can check the draft force in the chimney in such simple ways:

A toilet piece of paper - exactly how it is deflected.
The direction of the smoke from the cigarette.
The appearance of smoke in the room is already a reverse draft.
The roar in the chimney and the white color of the flame - the draft is already too much.
Yellow-gold flame color - good traction.

V Soviet time there was even a special device for measuring the draft in the chimney - an anemometer. According to it, certain objective data were obtained if the wind speed was more than one meter per second. Today, more modern devices are already used that measure the chimney draft in units of pressure - which is at the base of the chimney, and which is at the top. They cost a lot, but if your problem with cravings is not solved, it is better to purchase.

Why does this effect occur?

Where does it come from and who is to blame? Well, the most common reason- this is a mistake in the chimney design. Further, no less popular "culprits" are debris in the chimney, strong air currents in the chimney, and even a certain influence of atmospheric phenomena.

Reason # 1 - chimney design

First of all, the design of the chimney itself matters - for too high a draft is always strong, and for a low one it is often insufficient. Optimal length- a little more than 5 meters, then problems with traction rarely arise and certainly not because of the height of the pipe.

Also, the cross-sectional area of the chimney must correspond to the furnace - with too small cross-sectional dimensions and at the same time with a powerful furnace, a large volume of combustion products simply cannot escape normally, sufficient draft is not created. As well as a disproportionately voluminous chimney will lead to the fact that all the heat, as people like to say, "will fly into the chimney." And in no case should pipes of different diameters be installed at the chimney in different areas - there will be soot and problems with draft.

A serious obstacle to the movement of smoke is and uneven surface pipes - any deposits reduce the diameter of the pipe, and each time it is more and more difficult to melt the furnace. The angles of inclination with the turns of the chimney also create their own difficulties - if soot constantly accumulates in the corners, it will also interfere with normal draft. To prevent this from happening, when designing, adhere to the standard norms - 45 ° bend, 90 ° rotation.

The very shape of the smoke hole is also important: round is the most favorable for good draft, but with square and rectangular, problems often arise. So, in these corners, additional vortex occurs in the corners, which slightly hinders the overall flow and, in general, reduces thrust.

By the way, the most frequent problem poor draft - in metal chimneys. Their problem is that they quickly heat up, but also quickly cool down, and the cold air always sinks down. The good old brick chimneys are more reliable in this regard.

Reason # 2 - poor ventilation

Also, the lack of ventilation in the room where the stove is heated can lead to such a misfortune. Check for drafts as well - are they too strong? Such vortices right in the room can "confuse" the direction of the smoke, no matter how strange it may sound. By the way, intense air flows in the baths often arise from the stairs to the second floor. Keep track of this, and never open windows on staircase if it is much higher than the level of the firebox.

Pay attention also to ventilation if you have a gas water heater in a boiler room. It will still draw air from the combustion room, over time, a serious lack of oxygen will form and a critical rarefaction of air will occur. From time to time, an air stream will rush through the chimney, the column will go out, and the room will smoke. Is this your situation? Still deaf and sealed plastic windows stand? Take an urgent issue of ventilation.

Reason # 3 - external factors

Smoke can also enter the room due to high humidity on the street or strong wind... Or when it is already clearly warmer outside than in the house - the same pressure difference. If you have a reason for this, you will certainly hear bad smell burn. Then just open the window and ventilate well, let the temperatures even out a little.

And very rarely, but it happens that the reason why there is no normal draft in the chimney is the wind, which causes turbulence over the roof - if nearby buildings are located in a special way and too branchy trees nearby. Or the head is incorrectly directed in relation to the ridge of the roof - and this happens.

And, finally, the fact of exactly where your chimney is located plays a role. In the inner part of the bath, it has a good effect not only on the heating capacity of the system, but also makes it possible to maintain a strong traction even in cold weather. And here is the outer one that runs along outer wall, it warms up longer and condensation often forms in it.

How to solve the reverse thrust problem?

An object such as a deflector will help cope with the back draft - this is a mechanical fan, the task of which is to suck in smoke from the chimney shaft. See also how it is also worth, with the help of which just the traction is regulated. One gate is in the chimney, the second is usually either in the oven or in its door. Play with their position - this is a kind of draft amplifier in the chimney and the problem is solved in 99% of cases this way.

Sometimes reverse thrust occurs as a temporary option - only for a day or two. For example, if you have not used the oven for a long time, but here, because of the damp, cool weather, you decided to melt it. But heavy cold air has already accumulated in the stove and in the chimney, which will immediately begin to interfere with the creation of draft and the smoke will go to your living room. And what to do with intermittent reverse thrust? It's simple: identify the cause and fix it. And for safety reasons, also use a draft stabilizer for the chimney - this is a secondary air supply device, so that the force of air movement through the chimney is optimal. The stabilizer has a safety valve that will prevent too much pressure from building up in case of something wrong.

To get rid of cold air in the chimney after a long break in kindling, ordinary paper will help - burn a couple of sheets, slightly heated air will rise up the chimney and push out the cold. After that, already heat up the stove - there will be no problems.

And finally, clean the chimney in time - and if it is possible for it to install a pipe tee for cleaning, do not neglect it. We hope that by the end of reading this article you have already found the reason for the reverse thrust, with which we congratulate you!

Many have conventional ovens or various stove flues in houses, dachas or summer gazebos, but not everyone knows how to properly monitor them, and what to do when there is no draft in the chimney.

Traction is one of critical parameters chimney. It depends on it how well harmful combustion products will be removed from the unit. It is assessed based on the speed of movement along the chimney. Its quality depends on:

inner section of the pipe;
roughness of internal coatings;
temperature differences between air and combustion products.

Sometimes back draft can occur in the chimney of the stove.

Signs that back draft has occurred in the chimney

If you have a similar problem, it is very easy to notice its first signs: a large amount of smoke will be emitted in your stove, the glass will be constantly smoked, and when you are, the smoke will immediately go into the room. In case of untimely elimination of problematic traction, it can develop into the opposite. There are several valid verification methods:

Using a toilet sheet. With reverse thrust, it will deflect in your direction, and with normal thrust, in the opposite direction.
By the color of the flame. If the flame has White color , then it is too strong, if the flame is yellow-golden, then it is normal.
Via a special device that measures thrust at the base of the chimney of the stove and at the end. These devices have a drawback - they are very expensive.

Causes of occurrence

The most common cause of this problem is the wrong design of the stove chimney. High chimneys always have strong draft, and low chimneys - insufficient. The best unit is considered pipe 5.5 meters long.

Read also: Cleaning the chimney in a sauna stove

It is necessary to pay great attention to the cross-sectional area of the pipe. It must correspond to the capacity of the heating facility.

It must be remembered that it is strictly forbidden to make pipes with different diameters near the chimney - many problems will appear: soot on glass, soot, excessively strong or weak draft. Uneven or rough inner cover chimney is also big problem which is essential slows down the movement of smoke on it... Any residues in the form of soot, ash or other dirt gradually reduce the cross-sectional area of the chimney, and as a result, the firebox of the stove becomes more difficult every time.

The presence of slopes of the chimney and sharp corners also undesirable: they create additional obstacles to normal traction. If ash, soot and other dirt constantly accumulates in the corners, the smoke will not be able to escape normally. This means that the thrust will be slower. In order to avoid this, experts recommend adhering to standard norms: bend should be 45 ° and turn 90 °.

Fireplace in own home- the dream of any romantic. Who among us did not strive to be in cozy armchair at your own fireplace, to blissfully absorb the warmth spread by living fire with your whole body.

But the smoke that fills the room and does not want to go into the chimney does not fit into this idyllic picture. Reverse thrust in the chimney - this is the name of this unpleasant phenomenon. Why does it arise and how to deal with it? We have collected information about this for you and provided in this article.

We also paid attention to the methods of checking the draft in the chimney and examined in detail best options solutions to the problem with traction.

Before you understand the reasons for this phenomenon, you should understand the essence of what is happening. The heating device installed in the house, together with the chimney, forms an exhaust structure.

The air pressure inside and outside the device is not the same. Due to this difference in pressure, thrust arises - an aerodynamic directed flow of flue gases.

Safe and efficient work heating device assumes that the combustion products will move from the burning fuel along the chimney ducts. The air masses in the chimney are less dense, as a result of which they tend upward. They are replaced by colder outside air. This is exactly what the change of threads should be, ideally.

Reverse thrust is not only an unpleasant, but also a dangerous phenomenon, the consequences of which can manifest itself as a deterioration in the health of people and pets.

But sometimes there is a phenomenon called reverse thrust. In this case, the smoke generated by the combustion of the fuel is not directed outside through the chimney, but inside the room.

The occurrence of reverse thrust is not only unpleasant, but also dangerous. The penetration of combustion products into the room leads to serious poisoning, and carbon monoxide carries mortal danger.

The first signs of a failure in the movement of air masses may be not only smoke entering the room, but also a quickly smoked glass window in the firebox door. At first, the cravings may be just weak, but if you do not take action, over time it will reverse.

Sometimes there is another phenomenon associated with the movement of smoke - the air flow reverses its direction for a multiple time. This is how the thrust rolls over.

Reasons for reverse thrust

There are several reasons for reverse thrust. The main one can be considered the mistakes made in the process. Perhaps, during its construction, the rules for the use of building materials were violated.

A problem of this kind will not arise at all if the chimney is designed in accordance with existing standards: the turn must be done by 90 °, and the bend must be positioned at an angle of 45 °. Particular attention should be paid to the shape of the chimney section.

The most suitable form is a circle. If corners are present in the structure, turbulence can occur, which prevents the evacuation of gases.

The profession of a chimney sweep, as you can see, has not yet lost its relevance, but, with the increase in the number of private cottages, it has even become even more in demand.

If we compare brick and metal chimneys, then the draft in the latter will always be of lower quality. The problem is that the metal heats up pretty quickly, but it cools down just as quickly. And cold air, as you know, goes down.

Common reasons include the following reasons why there is no draft in your chimney:

Chimney obstruction. It may very well be that it is simply clogged with debris or smoked as a result of prolonged use. Rapid smoking can also occur if the chimney is made up of pipes. different diameters... In no case should this be done.
Calculation errors. Incorrectly calculated cross section smoke passage. Quite often, when designing a structure by non-specialists, disparities arise in the dimensions of the device's elements: the combustion chamber and the chimney. A powerful stove, for example, can produce more combustion products than a narrow chimney can carry. Therefore, you need to carefully follow.
Design errors. The height of the smoke evacuation system is insufficient for its efficient operation. A short chimney length may result in insufficient pressure difference. Optimal height the chimney is five to seven meters.
Narrowing of smoke channels. There are narrow and horizontal sections in the smoke exhaust ducts. In such places, soot accumulates especially actively, which interferes with the free movement of smoke.
Wind support. The chimney is located in the "wind back" area. The reason for the back pressure can be, for example, a tall structure located next to the chimney.
Improperly organized ventilation of the room. Lack of ventilation or an illiterate device leads to a lack of the required volume supply air... Therefore, it is important to give Special attention in a private house.

If the ridge of the roof is located above the level of the chimney, then the overturning of the draft can occur when a strong wind occurs.

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Option # 2 - special damper-gate

If problems arise with the stove, check the position of the gate. A gate is a damper that is designed to adjust the draft. It is usually installed on the non-insulated first meter of the chimney pipe. This damper allows you to do the job heating equipment as efficient as possible.

This device has several functions:

after the fuel burns out, it is used to block the pipe, which allows keeping heat for a long time;
as a draft regulator, the gate is used to change the section of the chimney: with excessive draft, for example, the smoke channel can be narrowed;
with his participation, you can control the quality of fuel combustion.

As a rule, the material for the manufacture of the gate is stainless steel, the thickness of which is 1 mm. Thanks to the polished surface of the product, soot can be easily removed from it.

The temperature that such a valve can withstand does not exceed 900 ° C. It is strong enough and has a low coefficient of thermal expansion.

The sliding damper should not completely overlap the chimney flap: 85% is the indicator that ensures safety standards for the operation of heating devices

The gate is presented in two models:

horizontal retractable plate, which is most often used in brick chimneys;
rotary gate or throttle valve.

The throttle valve is called the same plate, which is fixed on a rotating axis, placed inside the chimney or branch pipe.

The contours of the swivel gate plate follow the section of the chimney, which allows it to almost completely cover the pipe when the heater is not working

In view of the simplicity of the design, it is not difficult to do it yourself. Such a homemade product in operation will be no worse than a purchased product.

Option # 3 - chimney stabilizer

A product with such a telling name is otherwise called a breaker. This is a mechanism that automatically and dosed air into the chimney, allowing you to optimize the operation of the heating system without involving a person. To prevent overpressure build-up, the breaker is equipped with a safety flap.

Stainless steel is used for the production of the chimney draft stabilizer. The maximum temperature this device can withstand is 500 ° C.

The draft stabilizer installed on the chimney must be adjusted in accordance with the recommendations that you will find in the operating manual of your heating boiler.

The essence of the stabilizer is that it automatically adds cold air directly to the chimney. In this case, the temperature and speed of gas movement inside the pipe decrease. As a result, the efficiency of using the burned fuel is increased without any changes in the operating mode of the heater itself.

A breaker is installed, as a rule, on the chimney pipe. Moreover, the distance from it to heating device(boiler) must be at least 0.5 meters. The breaker should only be located indoors.

Since its functioning is based on a system of precisely balanced weights, the influence of natural factors on the operation of this device must be excluded.

The stabilizer setting can be considered complete when the minimum draft value is set on its regulator in accordance with the data specified in the operating instructions for your boiler. Either the exact parameter should be set, or by a division higher than the recommended one.

In addition to using the listed devices, to prevent back draft, you can lengthen the chimney pipe, straightening it as much as possible. Bends and sharp turns in the shaft increase cavitation as gases are evacuated to the outside.

Conclusions and useful video on the topic

If the problem with traction does not manifest itself in puffs of smoke in all rooms, this does not mean that it is not there. The device will help to identify it, with the device of which you can get acquainted by watching this video.

This product may save your life by paying attention to the problem in time, since carbon monoxide, for example, has no color or smell.

This video contains information about appearance deflector TsAGI and its constituent parts... You can see how to build this fixture yourself.

If you feel the strength to self-made stabilizer, then this video will be a real guide for you to action.

Any device operating in your home must work properly and not pose a threat to the life and health of people during its operation. Heating in this sense is no different from others. useful devices... A deflector, gate and stabilizer will help to make it work stable and efficient.

Are you having a chimney draft problem and are you trying to solve it on your own? Did you find the answers after reading our article? Or do you still have unresolved issues that we missed? Feel free to ask them in the comment block, and we will try to clarify these points.

Our grandmothers and grandfathers 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. Back draft in the chimney very often occurs gas boiler or column. In order for the heater not to deteriorate and to function properly, it is necessary to become familiar with nature. this phenomenon.

Reverse thrust

Draft is the directed movement of air through a chimney or other channel. Even from school, we know that such a movement is due to temperature differences or changes atmospheric pressure since the density warm air less than cold, and there is such a phenomenon as thrust, forcing air currents to move.

If such a process is carried out without the help of additional devices or devices, then it is called natural draft. When the air currents turn around and begin to move in the opposite direction, there is a reverse draft in the chimney. What to do in such situations depends on many conditions. First of all, it should be understood that rarefaction occurs due to the presence of sources in the room natural ventilation... To avoid smoke pollution in the room, it is useful to know exactly how much air is leaving the room, because the same amount must enter it. With the correct operation of the traction, it can be easily controlled, reducing heating costs and improving the quality of heating.

Interestingly, even with the right device chimney in a private house, a short-term occurrence of back draft, called overturning, may occur. The reasons are most often unfavorable weather conditions, and the effect does not persist for a long time.

Definition of thrust

At the beginning of each heating season Before starting the boiler or stove, check if there is a back draft 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 checking the draft in the furnace should be done with the help of a flame. For this, a match is lit and brought to the firebox. If the flame draws into the stove, then the draft is good, and you can start to heat the room. When the fire does not move, there is no draft at all, and if the flame blows into the room, then the draft is reverse in the chimney. What to do when starting gas boilers? Open fire cannot be used in this case. You should check where the smoke is drawing in 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 furnace, one can judge about excessive exhaust.

This process is influenced by a large number of factors. The main thing is the incorrect design of the chimney even 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;
shape;
pipe height;
the presence of additional devices that increase the traction performance.

Also, the indicators of the quality of air movement are affected by the number of people or devices consuming oxygen in the room. The latter include heaters, irons, stoves, and so on. Important for correct work and regular ventilation of the room.

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 weather conditions affect 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 air rarefaction is only a consequence of weather phenomena or human actions, therefore, the elimination of reverse draft in the chimney begins with precise definition the reasons for its occurrence. The main one is the incorrect design of the whole heating system and smoke extraction. In this matter, it is important to pay attention not only to calculations, but also to the selection of material. It is better to use ceramics or bricks for the chimney of the stove, but for boilers or gas water heaters ideal become metal pipes... In addition, the reason for the back draft in the stove chimney may be hidden:

in the blockage of the chimney;
in the presence of narrow sections in the smoke passage;
location of the chimney in the "wind back" channel;
in violation of natural ventilation;
under adverse weather conditions.

By the way, the availability of correct streams air even if all the rules for arranging the chimney are observed. The overturning of thrust appears especially often in strong winds, high humidity air or high temperature outside the window. This is true when using a gas water heater in the summer.

In any case, if such a phenomenon occurs, it will not be superfluous to inspect the smoke exhaust paths and make sure they are working properly.

Structural problems

The device of a chimney in a private house always presupposes the presence of a straight chimney, located strictly vertically. This technique is considered to be the most effective, since if there are bends, inclined sections or horizontal pipes in the path of the smoke, the thrust 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 provides for a slow heating of the smoke paths and a large accumulation of condensate during cooling, which in severe frost freezes easily. Together, these phenomena are conducive to the frequent appearance of reverse thrust.

Lowest resistance to push smoke into the right direction occurs only if there is in the structure round pipe... It is considered ideal for arranging the chimney of any heating device.

Correct installation

It is important to know that depending on the type of installed heating device, the installation standards and the connection rules will also change. Only with the correct calculation can you get effective work heating system without the appearance of rarefaction.

This is largely influenced by the combustion temperature of the fuel. The higher it is, the stronger the thrust will be, but at the same time the need to obtain a volume of air sufficient for combustion will proportionally increase. If ventilation does not provide it, then the stove or boiler will begin to take it out of the room, thereby provoking back draft.

To avoid this phenomenon, when operating the stove, it is necessary to use a fireplace tooth in its design. The device is a small ledge between the firebox itself and the smoke collector. The reverse draft in the chimney of the gas water heater provides for elimination 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 the draft in the heater, you should pre-select correct material for arranging his chimney. Metal chimneys should be installed for absolutely all gas boilers, water heaters and other devices. Such material promotes rapid heating, but also the same rapid cooling.

For heating sources in the house that use solid fuel for their work, brick or ceramics will be the ideal chimney cover. Such materials contribute to more heat, but at the same time they retain heat better.

It is important to pay attention to the smoothness of the surface when arranging smoke exhaust routes. The smoother it is, the less likely it is to quickly accumulate soot and the need to clean 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 for regular use of heating devices. The causes of blockages can be birds flying into the chimney, large accumulations of soot or plaster peeling from the inner surface 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 is dirt in the pipe, you can clean it with special brushes and even chemicals sold everywhere today. In order to delay cleaning the chimney as long as possible, it is recommended to use one of the preventive tips passed down through the generations.

The first one says that 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 pipe, to throw about half a bucket of peeled and chopped potatoes into the firebox while burning. The starch released during the combustion of the product can soften the plaque, and the soot itself will crumble from the surface of the chimney. Can be periodically burned in the furnace rock salt, this will delay cleaning too.

Chimney height

The presence of traction 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 level of the roof ridge and approximately 1.5 meters away from it. In this case, one should take into account the presence of trees or other buildings around the house, which can impair traction.

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 supply, 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 cooker hood or air conditioner.

Elimination of reverse thrust

So how to get rid of back draft in the chimney? In most cases, you can fix this problem yourself. To eliminate the short-term lack of traction in the furnace firebox, you should burn a couple of newspapers to warm up the air in the chimney, but most often the chimneys just need to be cleaned. If the thrust disappeared after the repair or did not appear at all, then an error in the calculations was probably made, and additional devices will need to be installed in the room.

These can be smoke exhausters, chimney vane and fans or deflectors. Extension of pipe length may be required. You can also briefly open the window to ventilate and bring in fresh air 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, it is prohibited to use heating devices until the malfunctions are eliminated.

Unpleasant burning smell, smoke in the room, poor burning of wood - all these are the consequences. back draft in the chimney... This is a problem faced by many owners of stoves, solid fuel boilers and other wood-fired heating appliances.

Why is there no draft in the chimney

Chimney is clogged with soot

This is perhaps the most common and main reason for poor traction.

In the process of burning firewood, soot is formed. It consists of particles of combustion products that stick together and settle on the inner walls of the chimney, which leads to a narrowing of its diameter. As a result, the movement of air is impeded.

Therefore, soot must be removed regularly. So you will not only improve traction, but also increase the efficiency and fire safety of the heater. To make the walls of the chimney less dirty with soot, you can use those that contain less moisture and other harmful impurities.

Insufficient air flow

When burning wood, it is necessary for the air to move "from bottom to top". That is, from the premises into the chimney and onto the street. For this, in the room where the heater is installed, an air flow - draft must be ensured.

If all windows are closed, if the ventilation is malfunctioning, then the smoke begins to move into reverse side- from the chimney into the room. That is, there is a reverse thrust.

The easiest way to solve this problem is to create the correct air movement in the room. For example, open a window before lighting a fire and close it 10-15 minutes after the flame starts.

Cold street air pressure

The chimney draft may deteriorate due to a decrease in outside temperature... Since cold air is heavier than warm air, it goes down and "presses" inside the pipe. This problem is especially often manifested in the presence of the previous two - no air flow and a clogged chimney. It enhances their influence.

Therefore, the solution is: insulating the chimney, removing soot and creating an air flow.

The presence of a visor on the chimney

Often a visor is installed on chimneys, which can prevent smoke from escaping from the chimney. As a result, an air "lock" of smoke is formed and draft deteriorates.

In such cases, the visor should be replaced with a higher one or removed.

Incorrect chimney design

Backdraft can occur as a result of improper design of the chimney: narrow diameter, too high a height, the presence of a large number of bends or narrowings.

To eliminate problems of this kind, you will have to rebuild the chimney, which will entail a significant investment of time, effort and money.

Brick collapse

Due to the constant heating-cooling process brick chimney, it can collapse. Bricks will fall off, fall down and clog the chimney.

To avoid such a situation, the chimney must be insulated. This will also solve the cold air pressure problem.

conclusions

So how to increase chimney draft? Here are a few simple steps not requiring special costs time and money:

Remove soot from the chimney. This is the first thing to do. You can do it yourself if minimum costs time, effort and money.
Provide air flow. Open the window for 5-10 minutes before lighting the fire. This will create the correct bottom-up air movement in the room. The window can be closed after the fire has flared up.
Insulate the chimney if it is not insulated. This will reduce the influence of cold air and will also extend the life of the chimney.

As a rule, these simple steps are enough to increase chimney draft... If the problem is related to design features chimney, then its solution will require more serious resources.

No chimney draft: 6 reasons for reverse draft and how to improve it yourself