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Why does the ventilation work in the opposite direction? Manipulations with the gate. Chimney draft

The proper operation of any kiln requires good traction. If it is, the smoke moves along the chimney and comes out into the atmosphere. However, the movement of smoke is not always the way it should be. Often there are cases when it does not move outward, but, on the contrary, begins to stand out from the oven and fill the room. This phenomenon is known as the reverse thrust.

Of course, it does not do any good. After all smoke is harmful to the body and the constant presence of its smell is very annoying to the owners of housing. Fortunately their noses with this problem can be fought and, most importantly, to warn it. To avoid this phenomenon, you need to know why it occurs. There are many reasons for its appearance.

Factors that create a reverse movement

Most of them are related to wrong chimney. So, the return draft in the chimney will always appear, if pipe height for smoke too low. In this situation, the pressure difference is very small and therefore the air either moves very slowly or does not move at all.

The second reason is too a small cross-sectional area of the chimney. In simpler terms, the return thrust is caused by a too narrow tube. She just does not manage to take away the smoke that is formed in the firebox when burning wood. Excess smoke is forced to move inside the room.

Also, problems arise when the chimney consists of different parts in diameter. They, together with the soot accumulated on their compounds, create an additional barrier to the movement of smoke.

No less important role in the appearance of reverse traction has and uneven pipe surface. Unevenness contributes to the accumulation of soot, which makes the passage smaller. At first, after creating the stove with the tube uneven in the middle, the burning air goes out without delay. However, the soot accumulates every day, the diameter of the pipe becomes smaller, and it is increasingly difficult to ignite the fire.

Do the angles and shape of the smoke hole

The reason why the smoke moves inside the house may be in the wrong angles of tilting and turning the chimney. This lack of design also contributes to the accumulation of soot. To avoid it, you need to do angles of inclination 45 degrees, a angles of rotation - 90 degrees.

The list of reasons for the incorrect design does not end there. It also includes shape of the smoke hole. If it is square or rectangular, then vortices begin to form in the corners. They also become a kind of barrier to the movement of carbon monoxide and, in the presence of additional factors, can cause back draft. The ideal form for good traction is the round one.

The material from which the chimney is made also affects the likelihood of reverse smoke movement. If the pipe is metal, then it quickly heats up and cools. Rapid cooling allows cold air to fall down. And such air is heavier than hot and therefore carbon monoxide changes direction. Brick The same designs accumulate heat and keep it long enough. Therefore, the latter is recommended to do to prevent the reverse movement of smoke.

Disturbance of ventilation

There are cases when the design is created well, and the return thrust in the chimney still occurs. Call it can disturbed ventilation.

Very strong drafts can draw smoke. Therefore, it is necessary to take them into account before the cultivation of fire and do so that they are not.

If fresh air does not enter the room with the furnace, then the oxygen that was, is used and decreases in quantity. This leads to the formation of critical air rarefaction. In this case, fresh oxygen will come through the chimney. His coming will be periodic. At this time, the reverse thrust will appear.

External factors

Directing the movement of smoke to others can high humidity on the street, strong wind or air temperature. In the latter case, a warmer temperature is observed outside than in the middle of the house. All these factors create a great difference in pressure. Smoke is easier to move inside the room than to climb up a special tap.

Cold air always cools the chimney. If the discharge of contaminated burning air is located in the middle of the house and comes out near the peak, then this cooling is less. More cooled chimney, located at the wall of the house. Therefore, it increases the chances of the appearance of reverse traction.

In a special way, the wind can influence the thrust. This influence is possible when the wind is very strong or the chimney is below the visor. Also, it appears in the case when there is near the branch pipe tall trees and houses. They contribute to the emergence of twirls of air, which cause rollover.

Reverse draft can also cause chimney contamination with foreign objects. For example, birds can nest.

Means of struggle

In the case of the emergence of reverse traction, it is necessary to stop the furnace. Further it is necessary to find out why such a situation arose and to eliminate the cause, and also to increase traction. The last procedure will avoid the reverse movement of carbon monoxide. It provides for:

Cleaning the chimney from soot.
Providing fresh airflow (opening windows for 5-10 minutes before igniting the fire).
Warming of the chimney.

An excellent means of struggle is deflector. It is a mechanical fan that sucks in carbon monoxide. Also use a slide (special damper). It allows you to adjust the traction. Apply two slats. One put in the chimney channel, the second placed in the door of the oven or in the oven itself.

Sometimes the owner can save several burnt sheets of paper. Their combustion is advisable when the furnace is not heated for a long time, and all its openings are filled with cold air. The heat released from the burnt leaves pushes out the cold air.

If there is an incorrect chimney design, you need to change it completely.

The presence of a good draft in the chimney - an essential condition for the full functioning of the stove or fireplace (read also: ""). Thrust is a directed airflow that occurs in the exhaust structure due to the difference in air pressure inside and outside, with air masses always striving to where the least resistance. Accordingly, the return draft in the chimney is a phenomenon in which the flow of air with smoke from the burning fuel in the furnace does not go out through the chimney, but back into the room. If the direction of the air flow changes to the opposite for a short time, then this is called rollover.

Why is there no traction in the chimney? The reasons for this can be a whole lot, ranging from the wrong design of the chimney and ending with nearby tall buildings or trees. With a bad draft, the wood that burns in the oven will emit a large amount of smoke, the door will instantly smudge (this is especially noticeable if there is a glass on the door), and when it opens, smoke will pour into the room. In such cases it is extremely important to identify as soon as possible the cause of insufficient traction and try to eliminate it.

Checking the draft in the chimney can be done by using a sheet of toilet paper (one should observe its deviation) or by using smoke from the cigarette (it is necessary to track which way it moves). The appearance of smoke in the room during the fire testifies to the return thrust, the flame of yellow-gold color is about good draft, and the flame of white color and the rumble in the chimney are about excessive traction. There are also more modern and precise ways to check the draft in the chimney, for example, special measuring instruments, allowing to determine the draft at the base of the chimney and at its exit. Analyzing the obtained data, it will be easier to determine what leads to the occurrence of insufficient or reverse thrust.

The main causes of poor draft in the chimney

Most often problems with traction arise because of miscalculations made at the design stage of the chimney, because often people who do not have any special education or experience have this. In addition, often to the violation of traction leads to clogging of the chimney, strong air currents arising in it, as well as various atmospheric factors.

Cause one - errors in the design of the chimney. Bad draft in the chimney can be the result of too low a pipe, whereas with an excessively high pipe, on the contrary, an excessively high draft occurs. Optimum is considered the height slightly exceeding 5 meters, in this case there should be no problems with thrust. Of no less importance is the cross-sectional area of the chimney, which must correspond to the dimensions of the furnace. Thus, the combination of a narrow tube with a powerful furnace will result in a large volume of smoke not able to normally exit and will leak into the room. With a disproportionately large chimney, all heat generated as a result of burning the fuel will literally fly out into the pipe. It is strongly discouraged to install pipes of different diameters at different sites, as this will inevitably lead not only to problems with thrust, but also to excessive formation of soot deposits. Soot, accumulating, in turn, will reduce the diameter of the pipe, as a result of which the process of kindling the furnace will become more complicated each time.

Affects the traction and shape of the hole chimneys: with a round rod, it will be much better than with a square or rectangular. The fact is that in the corners there are additional vortices that create obstacles to the overall airflow, resulting in a general reduction in thrust.

With regard to materials, the least likely to lack traction in the chimney will complain to those who have it made of their bricks, but with a metal chimney, problems with traction happen quite often. The fact is that the metal quickly heats up, but at the same time it cools down just as quickly, causing the cold air to fall down.

Reason two - violation of ventilation. Backward draft in the chimney can be caused both by the total lack of ventilation in the room for the furnace, and, conversely, by strong drafts that seem to confuse the smoke, which changes the direction of its movement and begins to exit into the room.

Particular attention should be paid to the issue of ventilation in the case when heating is used gas column. In the process of work, it will burn the air in the room, resulting in a serious lack of oxygen and the air will become very sparse. Because of this through the chimney will periodically burst air flow, which will invariably lead to damping of the column and the smoke of the room. Even more the situation can complicate the presence of airtight plastic windows, which do not allow air from the street. In such a situation, it is necessary to take care of the device for proper ventilation.

The third reason - external factors. If you can not in any way determine why the chimney has a reverse thrust, pay attention to various atmospheric phenomena, it is quite possible that they caused this trouble. To problems with traction can lead, for example, high humidity or strong wind. A similar situation occurs when the street is much warmer than in the house (in particular, this often occurs in the spring). In this case, you just need to open the window and ventilate the room well, allowing the temperatures to equalize.

Trying to find out the reason why there is no draft in the chimney, it is necessary to pay attention to the location of the chimney. Best of all, if it is located in the interior of the building, in this case, it will be less affected by various external factors. If the chimney is built from the outside of the house, then it will be warmer in the frost for a longer time, and the draft will be much worse. In addition, it will often form condensation.

How to get rid of reverse traction?

One of the ways to cope with reverse traction is to use a deflector - a mechanical fan whose function is to suck smoke from the chimney (read: ""). Another regulator of the chimney draft is a damper, which is a special damper. One slide is usually fixed in the chimney channel, and the second one is either in the oven itself or in its door. Having tried various variants of their arrangement, it is possible to find the optimum, allowing to solve a problem with draft.

How to make a traction controller with your own hands, the details on the video:

Sometimes the reverse thrust can be temporary, occurring for several days. This can happen at the beginning of the heating season, when in a damp autumn weather the stove melts after a long standstill. In this case, the cold air accumulated in the pipe acts as a limiter of the chimney draft, and the smoke, instead of going out, begins to fill the room. To solve the problem of temporary reverse thrust, it is necessary to find out the cause of its occurrence, and then - to eliminate it.

Foreword

Contents

By the concept of reverse draft in the chimney is implied the wrong operation of the heating system system and the chimney as a whole. The reasons why the return draft in the chimney are several, you need to know all about them in order to take competent actions to eliminate the malfunction. What to do with the return draft of the chimney and how to eliminate the reverse traction - issues that require the most careful study of all owners of the stoves.

Thrust is an aerodynamic directed air flow flue gases in any drawing structure. This phenomenon arises from the difference in air pressure inside the furnace and outside.

Air masses always tend to where there is least resistance. Therefore, the return draft in the chimney is formed when the flow of gases escapes from the burning firewood outside the chimney, and back into the room.

There is another term - "rollover". In this case, the direction of movement of the air flow for a short period of time is reversed. One of the causes of problems with traction can be standing near tall buildings or trees, as well as if the height of the chimney is below the roof ridge. In fact, there are many external factors.

The first sign of the presence of reverse traction is a large amount of smoke when burning wood in the furnace. At the same time, the glass on the door quickly smokes, and when the door is opened, the smoke immediately enters the rest room. This already indicates a weak craving. If you do not increase the draft in the chimney, then it can quickly turn from weak to reverse.

Check the traction in the chimney as follows. Using a toilet paper sheet, you can see exactly how it deviates. The direction of smoke from the cigarette will also indicate the presence or absence of proper thrust. The hum in the chimney and the white color of the flame indicate too strong a draft. But the yellow-gold color of the flame is an indicator of good traction. At present, numerous apparatuses are used, which measure the draft of the chimney in pressure units. With their help, measure the pressure at the base and at the top of the chimney.

Reasons for reverse traction

First, the cause of the return thrust can be the very design of the chimney. At too high a pipe the draft is always stronger, and at a low one it is often insufficient. The most suitable length is slightly more than 5 meters, then problems with traction will occur very rarely and will not be exactly related to the height of the pipe. In addition, the sectional area of the chimney must match the furnace.

With very small cross-sectional dimensions and simultaneously with a powerful furnace, a large volume of combustion products simply will not find a normal outlet, there will not be enough draft. Also, too large a chimney can cause all the heat to go outside. In no case should you allow the chimney to have pipes of different diameters at different locations. Otherwise, soot will form, and there will be problems with traction.

A large obstacle to the movement of smoke is the uneven surface of the pipe. Numerous deposits reduce the diameter of the pipe, and the furnace becomes more and more difficult to melt each time. Certain difficulties create and corners with chimney turns. With a constant accumulation of soot in them, obstacles will be created.

To prevent this, when constructing the chimney, standard rules should be followed: the bend should be at an angle of 45 °, and the turn must be 90 °. No less important is the shape of the smoke hole. The round shape is considered most suitable for the formation of good traction, and the square and rectangular shapes can create problems. In these corners an additional swirl is formed, which, to a certain extent, prevents the total flow and, therefore, reduces the thrust. Most often, a bad draft is observed in metal chimneys. Their problem is that they heat up quickly, but also cool down rapidly, and cold air always goes down. Therefore, the brick chimneys in this regard are of higher quality.

Reverse traction can occur due to a violation of ventilation or its complete absence. It is necessary to check whether there are drafts in the room. Intensive air flows in the baths often appear due to the presence of a staircase to the second floor. Therefore, you need to monitor the flow of air and never open the windows on the site, if it is located much higher than the level of the furnace.

Ventilation should be given special attention also in those cases, if there is a gas column.It draws air from the combustion room. After a while, there will still be a serious lack of oxygen and a rarefaction of air will be felt. Periodically, through the chimney will penetrate the air flow, the column will go out, and the room will smoke.

There are also external factors affecting the formation of reverse thrust. Smoke can enter the room due to high humidity in the street or in strong winds. This also happens when the outside is noticeably warmer than in the house, so a pressure difference arises. If the reason is this, you can feel the unpleasant smell of burning. In this case, you need to open the window and ventilate well, in addition, and the temperature will slightly level. It is extremely rare that the reason for the disturbance of traction is the wind, which causes turbulence over the roof. In addition to this, it may still be wrong with respect to the ridge of the roof directed towards the head.

And, finally, the location of the chimney plays an important 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 good traction even in severe frosts. And the external chimney, which runs along the outer wall, requires more time for warming up, and condensation often forms in it.

Temporary return draft in the furnace

Sometimes the reverse thrust in the furnace appears as a temporary phenomenon - only for a couple of days. This often occurs after a long standstill of the furnace or furnace during the cool weather.

By this time in the furnace and in the chimney there is already accumulated heavy cold air, which will immediately prevent the creation of traction, and smoke will enter the room.

If the return thrust arises periodically, you need to establish its cause and eliminate it. For safety it is recommended to use the draft stabilizer for the chimney, which is a secondary air supply device for the optimal force of its air movement through the chimney. The stabilizer has a safety valve, which in case of emergency situations will prevent the occurrence of excessively high pressure.

To get rid of the cold air in the chimney after a long break in the kindling, you can use ordinary paper. To do this, you need to burn a couple of sheets, and slightly heated air will rise through the pipe and push out the cold. After that, you can melt the oven.

It is necessary to clean the chimney in time. And it is desirable to install a tee pipe for cleaning. Then the return thrust will not bother.

Deflector on the chimney pipe (with photo)

Look at the photo: the deflector on the chimney is a mechanical fan sucking smoke from the chimney shaft.

It is also necessary to see how the damper is located - a special damper, with which the thrust is regulated. One slat should be in the chimney channel, and the second one, as a rule, is located either in the oven or in its door. You can try to change their position.

Modern deflectors for the furnace are:

with a flat top;

equipped with an opening lid;

having a gable roof with two slopes on the pipe;

with a semicircular tip.

The deflectors, having a flat top made of copper, are often placed on the modernist style baths.

For modern buildings, a cap with a semicircular tip is most suitable. And such a device, like a deflector with a gable roof, best protects the chimney from snow.

In general, sheets of galvanized iron are used for the production of deflectors, although recently there are often such baffles in which metal is covered with enamel or even a layer of plastic.

Some models of baffles need to be inserted with a door in the direction of the smoke box. To do this, you need to make one edge on the wall, gently lift the second one and lower it into place. For ease of installation, remove the plates from the back and side walls.

In addition, the deflector has two handles, which are called "cold hand" and are designed to control the oven.

You can choose a model in the store, or you can easily make a deflector for the chimney yourself. Before you make the deflector on the pipe, read the detailed description of the work stages.

Before proceeding directly to the manufacture of the deflector, it is necessary to determine the material from which it will be made. This can be copper, galvanized iron or stainless steel. In spite of the fact that copper is quite expensive material, it is better to stop your choice on this metal, as it is resistant to atmospheric phenomena. This is due to the fact that the deflector is located in one of the most inaccessible places of the bath, and frequent repairs will be problematic.

Before you make a deflector, you need to draw on the cardboard a sweep of all the main parts, including the hood, diffuser and outer cylinder. Then you should transfer everything to metal and cut them using special scissors. Next, you need to connect the parts to each other with rivets, bolts or welding. From the strip of metal you need to make brackets, with which the cap will be fixed on the surface. Attach the cone to the hood. Collecting the deflector on the chimney pipe, you can proceed to install it on the roof. First it is necessary to fix the lower cylinder using bolts and nuts. With the help of the clamps it is necessary to fix the diffuser on the lower cylinder, and on it to install the hood with the cone back.

The device of a deflector-weather vane on a chimney for the furnace

There is a new popular version of the deflector - a weather vane-deflector.

It is (see the photo above) a special device, in which the body rotates simultaneously with the visors deflectors curved on it. Such visors are connected to the bearing assembly. The weather vane, located in the upper part, allows the entire structure to always be located taking into account the direction of the wind.

The work and design of the weather vane for the chimney are fairly simple and understandable. The flow of air penetrates into the space between the canopies, accelerates and thereby creates a rarefaction zone. As a result, the thrust in the chimney increases, the fuel in the furnace burns well, and the air exchange also improves.

You can also make a weather vane, after which the structure itself should be attached to the chimney section by means of a ring with a bearing assembly. It is a stable influx of fresh clean air and a qualitative withdrawal of combustion products is the key to a good work of the furnace.

The device of a rotary gate for a chimney of a bath furnace

An important role in the regulation of the traction force is played by the device of the gate, which is a special horizontal plate, which, due to its position, increases or decreases the section of the chimney. In this plate there is a small hole that does not allow the gate to completely seal the chimney completely. This is necessary to comply with fire safety rules. Often the horizontal slide is mounted in the brick stoves, but can also be installed in steel chimneys. Rotary, the chimney for the chimney is a plate that is mounted on the axis. Its adjustment is done by turning. The only drawback is that the rotary gate has weld fusion, and such an unpleasant phenomenon has been observed very often lately.

Both types of the gate have certain differences: the flap on the chimney, i.e. the horizontal gate, allows to regulate the passage section, and the choke only shows whether the chimney is open or closed. In extreme cases, you can make a commit using a chain.

In order to properly choose the gate for the chimney, it is necessary to determine the type of furnace and take into account some other features. The installation of the gate is made, except for some new models, where the combustion process is already regulated by means of the supply air control, for which the deflector is used. In a gas oven it is recommended to use rotary gate, which is able to completely eliminate the risk of complete closure of the chimney, and the flame does not jump out randomly through the ash pan. If a damper is used, it must be ensured that there is always a gap of at least 30-40% of the chimney sectional area. Do not install rotary valves bath furnace with a periodic action, because the damper always passes the steam in the closed state at the supply. But there is an opinion that when the rotary gate is in the open position, the pipe below is difficult to clean afterwards.

As a rule, a damper is sold together with a chimney, as it is an integral part of it. But you can also buy a slide in any profile store. The main thing is to correctly determine its size.

Cast iron gate for chimney

There are several variants of the gate, depending on the material from which they are made. Chimney valves are most often made of cast iron. But this material is quite heavy, and the installation of such a cast iron gate is complicated. In addition, it can be placed only on brick stoves. With all its advantages, the cast iron slide for the chimney has a lot of weight, so installing it with your own hands can cause difficulty.

Slate and valve for chimney pipe made of stainless steel

A chimney for a stainless steel chimney is usually made with a thickness of 1 mm. Their advantage lies in the fact that they are able to withstand temperatures up to 900 ° C, have a special mechanical density and are resistant to corrosion. Steel is pretty smooth. It can additionally be polished to a shine, and, therefore, soot on such a slate will not settle. Another plus is that the steel has good thermal conductivity. Such a valve is capable of blocking the chimney by 85%, and the carbon monoxide will be excreted well.

You can make and install the slide independently. As a rule, the chimney is mounted in the chimney at the stage of its erection. It should be located on the first meter of the chimney. This is necessary for ease of use. Just keep in mind that the area where the gate is located should not be insulated, otherwise it can jam.

The shiber is a kind of the initial part of the chimney, after him the pipe itself begins immediately. Using the gate is the easiest way to regulate traction.

Before making the gate, it is necessary to lay out the first brick row of the chimney. A fragment of the gate valve for the chimney is cut in the second row. In one brick, you need to make a groove in the groove for the handle. The main thing is to lay out the second brick row in such a way that there are no cracks in it. If the cracks do form, they must be filled with cement mortar. The installation of the slide gate for the chimney can also be done without fastening - it will be kept only due to its close fitting to the structure. For correct adjustment of the draft, it is necessary to ensure the supply of air to the combustion zone. It must be remembered that with a closed slate, carbon monoxide will still leak into the bath, even if there are no visible fumes and smoke. It is very dangerous! In a few hours you can completely fade. Closure of the gate is allowed only at the very end, when everything is already burnt in the firebox and will be slightly covered with ashes.

For the normal operation of the vast majority of modern heating appliances, the chimney must be arranged. Its functioning, in turn, is impossible without sufficient traction. The term "draft" means a directed airflow that forms in the exhaust structure due to a difference in the temperature of the smoke and outside air, and also because of the difference in their density. Because of insufficient or worse - reverse thrust, the combustion products do not go outside, but return to the room, which can lead to disastrous consequences. Today we will talk about reverse traction; we describe its main causes and ways to eliminate them.

The concept of reverse traction. Traction control

Reverse traction is the exit of smoke streams not to the street, but their return to the heating appliance, whether it's a fireplace or a stove. If you find yourself experiencing this phenomenon, know that you should immediately stop the operation of the heating device and repair the malfunction.

There are cases when the air flow sharply and with an enviable regularity briefly changes its direction. This phenomenon was called "overturning traction".

The consequence of both of the above problems is incomplete combustion of fuel, which entails excessive smoke formation. Smoke enters the room and can harm the health of people living there.

According to experts, traction that fluctuates within 10-20 Pa is considered sufficient. If the thrust is lower, you need to determine the reasons for what is happening and bring the indicators back to normal.

You can check the traction in several ways.

Special instrument - anemometer, it provides accurate data of the speed of the directional air flow. If the device is not available, you can use the improvised means.
Using a sheet of toilet paper. Bring it to the door of the stove or fireplace and pay attention to which way it deviates. If in the direction of the room, there is a reverse thrust.
Smoke from a cigarette. If you smoke, you can use cigarette smoke as an indicator. The principle is similar to that described in clause # 2.
The color of the flame. If the flame has a yellow-golden color, then the draft is good.

Advice! To check the direction and force of the thrust, bring a lit cigarette to the heater door and look at which direction the smoke will go.

Reasons for back pull

The chimney pipe is too low. This leads to a difference in pressure, which entails a weak pull or its complete absence. The optimum height is 5 meters.
Wind podpor, that is the phenomenon when in the immediate vicinity of the house there is a higher construction, preventing the formation of air flow.
Incorrect chimney design.
Problems with ventilation or its complete absence.
The presence in the chimney of several narrow channels-smoke.
Garbage in the chimney.

Elimination of reverse thrust

The process of eliminating the return thrust depends on the reasons that caused it. We will describe the most accessible and common ways to solve the problem.

Manipulations with a gate

Influencing the force and direction of thrust. Usually, during the construction of a stove or fireplace, two slats are installed. One is in the chimney, the other is in the stove or in its door. "Play" with the position of these dampers, this often increases traction, and the problem is solved by itself.

Advice! If there is no traction, pay attention to. Perhaps it covers the chimney, because of which the smoke can not go out and comes back into the room

Application of the deflector

A deflector, also called a smoke pipe or a fluke, is a short pipe installed at the top of the chimney, designed to protect it from the wind, and to strengthen the thrust. Since the cause of the reverse thrust is often external factors, in particular, the air streams blown into the chimney by wind, setting the deflector is the easiest way to solve the problem.

Using the traction control (stabilizer)

This is a special device that creates air flows in the chimney and controls their strength. It stabilizes the traction and, among other things, contributes to fuel economy, and also prevents the ingress of combustion products into the room.

Timely cleaning of the chimney

The cause of the emergence of reverse traction is often getting into the chimney of debris or accumulating there a huge amount of soot. Therefore, do not be lazy to systematically check the condition of the pipe and, if necessary, to remove clogging. today there are a wide variety.

conclusions

As you can see, the reasons for reverse traction can be very diverse, and the way to solve the problem directly depends on them. We strongly recommend that you monitor the operation of the heater and, if any malfunction is found, immediately take measures to eliminate it!

Related Videos

The directional movement of combustion products along the flue ways is a fundamental factor for the efficient and safe operation of almost all heating devices. There is a movement of air masses in the chimney at a difference in pressure, temperature and density, between the air in the smoke channel and the atmosphere. Warm air in the chimney has a lower density, and tend upwards, and its place is taken by cooler air masses.

But there is such a thing as a reverse pull. The manifestation of this effect can be seen immediately and with the naked eye - the smoke from the combustion of the fuel, goes not so much as it is put in the chimney, but moves into the room, thus creating the danger of poisoning the person with combustion products and carbon monoxide. Why is the return draft in the chimney and how to deal with this phenomenon, we will consider in this publication.

The causes of this phenomenon

Reverse traction, as it became clear from the foregoing, there is an effect, and there may be several reasons for this. And above all, the main cause of poor draft in the chimney, and accordingly the appearance of this effect, is the wrong design heating system and non-compliance with the rules for the use of building materials for the installation of a smoke removal system. Among other reasons, the most common are:

Banal clogging of the chimney.
Wrong calculation of the cross section of the chimney.
Non-observance of the height of the smoke removal system.
The presence of horizontal and narrow sections in the chimneys.
The location of the chimney in the zone of "wind".
Incorrectly organized ventilation system of the room and insufficient supply air.

But it often happens that the phenomenon of reverse traction occurs suddenly, on previously normally operating equipment. This can occur due to unfavorable weather conditions, such as strong wind, fog or high air temperature in the street during the summer. Each of these causes is able to deploy the direction of the combustion products, thereby stopping the normal process of smoke removal from the heating devices.

How to determine the insufficient draft in the chimney system

If the reverse traction is visible to the naked eye, then a bad draft in the chimney should be determined, and it must be done before each start of the heating devices. Several basic methods are used for this.

Tip:
If suddenly the draft in the chimney is gone, then, first of all, it is necessary to determine the cause of what is happening. Visual inspection of the smoke channel is the first thing to do. Often, you just need to clean the chimney, and the effect of reverse traction in it will disappear.

Reverse draft and ventilation

Many users of stoves and fireplaces, especially after repairs in the house, say that: "There was a return draft in the chimney, what to do about it." All immediately interested in solving the problem, but few people wondered why it was after repair in the room that this phenomenon appeared.

Very often, the effect reverse traction appears in homes with established plastic windows and high-quality doors. Most often, when replacing windows and doors, the owners of premises do not think that after such alterations the normal functioning of the ventilation system ceases.

Strangely enough, the appearance of this effect is directly associated with ventilation, or rather, with its absence. Warm air has a lower density and therefore tends to rise. When heated in a heating appliance, the air masses rise up the chimney, and the colder air rushes into its place. But in the process of work, it may happen that a low pressure area will gradually appear in the sealed room and the discharge will become so strong that it will start to draw fresh air from the chimney by "overturning the draft" and turning the smoke in reverse side. The better the draft in the chimney, the longer there will be no effect of the reverse movement of the combustion products, but without sufficient supply air this process is inevitable.

In order to solve this problem, it is necessary to organize the influx of air masses from the street. This can be solved in several ways:

Creating an influx of air masses through loosely closed windows, doors or windows.
Installing the inlet wall valves.
Mounting inlet valves on the PVC windows.

Each of these measures will facilitate the penetration of street air masses into the house, preventing the reduction of pressure in the room and the formation of the effect of reverse traction. What a way to choose, it is best to consult a specialist.

Ways to improve the removal of combustion products

Do not forget that even with the best ventilation system, the smoke removal will be ineffective if the chimneys are blocked or incorrectly designed. With the wrong project, there is only one way to fight, the chimney dismantling and complete rework.

If there is a defect in the chimney ducts that reduces the flue gas discharge, several devices can be used that will improve this process.

Reverse traction is a very dangerous phenomenon, and not only by the appearance of carbon monoxide in a residential building, but also by a spark directed into the room. At the first manifestations of this effect, you should stop using the stove or fireplace, try to determine and eliminate the cause yourself, and if this does not give a positive result, immediately contact the specialists.