Chimney deflector of them registered. Chimney deflector

You often see beautiful and unusual caps that homeowners place over chimneys. At first glance, it seems that they perform only a decorative role, but they have functions that are very important when it comes to the safety of the chimney system. Consider why you need a cap on the chimney pipe, on what basis it is selected, what types of structures exist and how to make it yourself.

Caps on the chimney pipe are a fairly common occurrence. However, many people are confused about what they are needed for. There is an opinion that they protect the pipe from condensate. However, this is not quite true. Evaporation and collection of moisture occurs in the inside of the pipe and a cap on the chimney pipe (photos on the Internet clearly demonstrate the principle of its operation) can do little to help here.

Why do you really need a cap on the chimney pipe? Let's take a look at a few of its main features:

protection of the inside of the pipe from the ingress of various foreign objects, dust and debris;
extending the operational life of the pipe by protecting it from precipitation;
some caps, due to their design, increase the draft in the pipe and do not allow strong winds to overturn it;
perform an aesthetic function, giving the pipe an attractive appearance.

It is worth recognizing that most of the decorative wind vanes on the chimney pipe do not at all improve the functional characteristics of the pipe, but, on the contrary, reduce these indicators. An exception to this rule can only be considered nozzles that have the following types of construction:

Weathercocks-deflectors.
Nozzles with similar industrial exhaust deflectors.

The first option is much more efficient than the second. The semi-cylindrical body remains movable due to the bearing. It can rotate depending on weather conditions, and like a weather vane blade fixes it so that it is constantly turned to the wind with its back. As a result, the smoke draft increases due to the vacuum generated inside.

The principle of operation of the second mechanism is as follows: a certain rarefaction appears inside the deflector itself, due to the fact that the air flow formed as a result of the wind load goes around the head on the brick chimney pipe. As a result, such an “umbrella” functions differently, depending on weather conditions: in windy weather, it increases traction, and in calm, on the contrary, it reduces.

Note! A weighty argument in favor of the first option is that the construction chimney for chimney pipecompletely eliminates the danger of blowing out the draft with the wind, which nevertheless sometimes happens when using the second type of system.

Varieties of caps for the chimney

In addition to the designs already considered, there are many others that are also widespread. All of them are combined general principle actions and devices are devices that serve to cover the cut of the pipe, while leaving a small gap so that the combustion products can exit the pipe to the outside. The shape of the deflector on the chimney pipe can be almost anything, but according to the material of manufacture, they can be divided into several groups:

from galvanized (roofing) steel;
made of galvanized metal, on top of which polyester powder coating is applied;
stainless steel;
copper;
alloyed from titanium and zinc.

If we talk about making a do-it-yourself cap, then galvanized steel with a thickness of about 0.8 mm is most often used for this. This option is most preferable because of its availability, as well as a fairly long service life (about 20 years). To better understand the design of such a chimney cap, photos and diagrams will serve as an excellent guide.

Galvanized steel has only one serious drawback - it quickly loses its original appearance, tarnishes. It is subject to various external factors that have a negative impact on it. Metal, which additionally has a powder coating, withstands such an impact much better, but such material costs much more.

All other metals retain their appearance for a long time, but their cost is also higher. However, the price is reflected not only in their appearance, but also in the service life. And although copper also tends to fade over time, here we are talking more like decades than years.

How to choose and buy a chimney cap

Choosing the right cap design is not an easy task. And first of all, it is worth considering the type of boiler house used and the type of fuel that is used. As an example, consider the fact that only nozzles are suitable for chimneys of gas boilers. They have an open top and are the only ones suitable for use in this case.

Note! The installation of nozzles on pipes that provide chimney from gas boilers is regulated by regulatory documents that prohibit the use of umbrella caps for this type of chimney.

Such a ban has a completely logical justification: in winter, when the temperature drops below zero, the chimney cap is subject to freezing and can be covered with ice. Over time, ice can close most of the smoke opening, causing it to accumulate inside the structure. In this case, there is a serious danger to the health of the inhabitants of the house, since accumulating inside, smoke can cause serious poisoning.

Freezing occurs as a result of the formation of condensate, which appears on the surface of cold metal upon contact with sufficiently warm combustion products. The situation is different with . Due to the fact that its efficiency almost never exceeds 70-80%, the gas temperature accordingly remains within 150-250°C. It is not dangerous and the use of the nozzle is quite acceptable.

Useful advice! Do not forget that in the case of using solid fuel, the cap will very quickly become covered with black soot. So do not choose too complex relief models that cannot be cleaned.

What are chimneys depending on the shape

The variety of forms of modern chimneys is very large. Here you can find almost any options. Consider the most popular of them, which have an unusual geometric shape and are able to decorate any pipe:

weather vane standard form: looks like a house with a hipped roof;
chimney in Art Nouveau style: arranged like a standard one, but additionally has a flat top;
European-style chimney: has an unusual appearance due to the semicircular top;
caps with a gable roof, which has four slopes (a very functional design that is well ventilated and at the same time protects the pipe from snow);

weather vane with a weather vane;
weather vane equipped with a detachable lid.

Wind vanes with a weather vane are distinguished by the fact that a special damper is located inside the structure, which allows combustion products to calmly exit the chimney even in the most windy weather. And an additional opening cover provides easy access to the chimney channels to clean them.

Depending on the shape, the roofs of chimneys are divided into the following categories:

tent;
gable;
four-slope;
semi-cylindrical (or vaulted);
flat;
spire-shaped;
four tongs.

However, in most cases, this parameter does not affect the functionality of the device and serves purely aesthetic purposes, providing the chimney with a unique appearance.

Which cap for the chimney pipe to buy, given the structure of the pipe

Another parameter that you should focus on when choosing a cap is the structure of the chimney. The ideal option it is customary to consider a three-layer structure of modular sandwich panels. In this case, there is simply no need to protect the chimney from precipitation. All the moisture that gets inside does not have a negative effect on the pipe, but on the contrary, is beneficial, cleaning the pipe and collecting in the condensate trap.

If it's about gas boiler, then there are no other options except for the nozzle. But if you are dealing with a solid fuel system, then there are many options, although the deflector-weather vane is considered to be the most popular and functionally justified. Demonstrate the beauty of such chimneys on the pipe photos, in large numbers offered on the Internet.

Many questions arise when it comes to arranging a brick pipe. There are no contraindications here if you are dealing with a solid fuel system. In this case, you can choose any hat you like. But if it is used gas system, then the installation of an umbrella on the chimney pipe in this case is prohibited.

But here a completely logical question arises: what about the destructive power of moisture, which eventually gets inside? For this case, special structures are provided that can completely cover the brick base of the pipe.

Do-it-yourself chimney deflector: drawings and photos

Do-it-yourself visor on the chimney pipe is not uncommon and many are trying to make it. With a sheet of galvanized metal and improvised tools, you can save a lot of money on buying and installing a deflector. For this you will need the following:

a drawing set, a fairly long ruler, as well as a tape measure and a marker;
shears for metal, fasteners (drill-tapping screws with a 15 mm press washer or a riveter);
drill with various drills;
material for the cap (galvanized, aluminum or stainless steel) with a thickness of 0.3-0.5 mm;
additional metal parts for the manufacture of rigid fasteners.

In order to make a chimney on the chimney pipe with your own hands, you need to make the appropriate measurements, and then, guided by the drawing, you can get to work.

Using scissors for metal, you can make a chimney weather vane with your own hands. To do this, cut out the details of the required size. Then roll up the diffuser body and drill holes in the top and bottom so that after the rivets are fixed, you get a one-piece structure. Do-it-yourself chimney cap drawings will help you assemble it correctly.

After that, you can begin to manufacture the upper cone. You can attach the paws directly to it (usually you need about 6 pcs).

Before you completely assemble the wind vane on the pipe with your own hands, do not forget to fix the fasteners with which the diffuser will be connected to the lower cone of the structure. As fastening, you can use the same rivets. In order to mount the cap on the pipe, it is best to remove its upper part in order to put the cap on the studs or paws, and then install the entire structure back.

Useful advice! Do not neglect the quality of the installation of the deflector on the pipe. Being under a constant wind load, poor-quality fasteners will soon lose their characteristics and the structure will fall apart.

Of course, a do-it-yourself fungus on the chimney pipe has no decorative value. Its design is primitive, but it is able to increase traction by 20-25%, and also protect the roof from accidental sparks. Using the drawings, do-it-yourself cap on the chimney pipe can be made quite simply and at the same time spending a minimum of resources.

Chimneys for brick pipes and forged chimney caps: features and prices

On the Internet you can find many tips on how to make a chimney visor with your own hands. However, not everyone wants to bother about it, and many prefer the opportunity to purchase a finished product.

Prices for chimney caps are very diverse, and you can buy a chimney cap for a chimney pipe starting from 700 rubles. At the same time, the simplest umbrella for a chimney pipe to buy will cost 300-400 rubles.

If you want to buy a deflector for a chimney pipe, which can truly become a roof decoration, you will have to spend a lot of money. Forged chimneys cost from 7000 rubles and more. The price of a chimney for brick pipes largely depends on its size, material of manufacture, as well as complexity. forged items, which are very diverse. You can see photos of forged chimneys on specialized sites.

Another quite expensive, but very beautiful option- chimney weather vane. It comes in a wide variety of shapes and sizes, and at the same time it perfectly replaces a simple umbrella with a chimney pipe. Many craftsmen believe that using the drawings, it is quite possible to make a weather vane on the chimney with your own hands. However, this requires a lot of skill. The cost of the finished version will cost from 5000 rubles.

Depending on your preferences, you can buy a ready-made chimney cap or you can make your own chimney cap. In any case, it would be useful to look at the photos of the chimneys that are on sale in order to get general idea about their diversity and purpose.

Everyone noticed the cap rising above the chimney, but not everyone knows why it was installed there and what its purpose is. This part is called a deflector. This is translated into Russian as "reflector".

It is a small canopy over the pipe and serves to protect it from aggressive influences. environment: wind, precipitation and to create the necessary traction.

Sometimes it is called a chimney, and made in some stylish form - a weather vane. The deflector installed on the chimney pipe is a thing that came to us from antiquity architectural element, and today it can also embellish the roof of any building. In addition, it performs, in addition to a decorative role, also an important practical function - it enhances the movement of air in the pipe.

What is it and why is it needed?

Regardless of which one is used in the house heating equipment and what kind of coolant is used, any heating system is equipped with a chimney. Thanks to it, the extraction of combustion products is ensured. How it will function directly depends on what will be the quality of the entire system.

But the chimney, which is not always beautiful and installed in accordance with all the rules, functions perfectly. This is especially noticeable in strong winds, when there is strong pressure on the gases in the pipe. So that nothing could interfere with the correct functioning of the entire heating system, a deflector is used, which is worn on the chimney pipe.

Its main purpose is to increase traction by preventing air flow. The wind, bending around the obstacle, leads to the formation of a low pressure zone around the pipe. The result is increased traction. Regardless of the design of the deflectors, they are all involved in the same process - the emergence of a zone reduced pressure when air flows over an obstacle. Thanks to the device, the wind does not reduce, but rather enhances traction.

Air flows, in contact with the surface of the deflector, go around it and begin to move faster, creating an area of rarefaction. In physics, this phenomenon is called the Bernoulli effect. It is thanks to him that the thrust in the pipe increases.

Studies have shown that when using a deflector, even the most common one, the efficiency of the chimney increases by 20%. Its usefulness also lies in the fact that it protects the pipe from wind-borne debris and precipitation, in the form of rain, hail or snow. The chimney works equally under any conditions, regardless of the weather conditions outside.

Popular product types

You probably noticed that they are various shapes. Modern devices may have different tops:

flat
Semicircle
with lid
With gable roof

semicircular cap

The first type is most often installed on houses made in the Art Nouveau style. For ordinary modern buildings, a semicircular cap is mainly used. A deflector gable roof does the best job of protecting the chimney from snow.

Mostly chimneys are made of galvanized iron, less often of copper. But today products covered with enamel or heat-resistant polymer are coming into fashion. If the device is used on ventilation ducts where there is no direct contact with heated air, then a plastic cap can be used.

The designs of the deflectors are also different.

In the domestic market, the most popular are:

TsAGI deflector, spherical with rotation, open "Astato"
Grigorovich's device
"Smoke Tooth"
Round chimney "Voller"
Star Shenard

Various types of chimney caps

The TsAGI deflector has become the most popular in the Russian open spaces. Its package includes:

Branch pipe (inlet)
frame
Diffuser
Umbrella
brackets

You can buy a factory deflector and install it on the chimney, but some people prefer to make it themselves from scrap materials. To do this, follow a few simple rules.

This is a mechanism that has a rotating body and is connected to a bearing assembly, specially curved parts are fixed on it. The weather vane itself is located on top, it allows the entire device, as it were, to constantly keep in the wind.

The ring with a bearing assembly built into it is attached to the chimney cut with strong bolts. The air flow passing between the visors is accelerated, which leads to the creation of a rarefied zone. Thrust, respectively, increases and increases the efficiency of the output of combustion products.

The weather vane-deflector is made of materials with high resistance to corrosion. It has an elementary design and can be used in chimneys on any building.

How to make a do-it-yourself chimney deflector

First you need to decide what material it will be created from. It can be galvanized iron or stainless steel. Copper is also suitable, although it is an expensive material. The use of these metals is due to the fact that the deflector must be as resistant as possible to temperature extremes and atmospheric influences.

The device has its certain parameters that must be adhered to. For example, the height of the chimney should be 1.6-1.7 parts of the inner diameter of the pipe, and the width should be 1.9.

Sequence of work on independent creation deflector is as follows:

On cardboard we draw a scan of the main details.
We transfer the patterns to the metal and cut out individual parts.
We connect all the elements to one another, using fasteners or welding for this.
We make steel brackets needed for fastening the cap on the surface of the chimney.
We collect the cap.

A self-made deflector is first assembled and only then mounted on a pipe. The cylinder is installed first, which is fixed with fasteners. Using clamps, a diffuser is fixed on it, as well as a cap, in the form of an inverse cone. This simple element allows the device to function in any wind.

Watch the video, do it yourself and step by step:

To make a cap yourself, you will need the following items and tools:

Rubber or wooden mallet
Hammer
Bar
clamps
Scissors for working with metal
Steel corner.

To simplify the process of assembling the device, corners are specially cut on all parts on both sides.

The installation of a deflector is mandatory and is most effective in the presence of an indirect chimney.

When making the device yourself, you must strictly adhere to the proportions indicated above. If the deflector installed on the chimney does not meet these parameters, then it will not be able to properly perform its main function of creating good draft.

We make the cap ourselves, video review:

When making metal blanks on your own, it is best to do this using cardboard patterns cut to the required dimensions. By attaching them to a sheet of metal, it will be enough to circle the details along the contour and you can safely cut them out without fear of making a mistake.

The presence of an inverse cone under the cap is also mandatory requirement to the design. With its help, the chimney will function effectively under any climatic conditions.

If the pipe has the maximum allowable diameter, then installation will require the use of an extension made of wire.

The arrangement of the upper part of the chimneys and ventilation ducts should protect the channel from debris and prevent draft suppression due to the strong influence of the wind. The simplest option is a cone-shaped cap that covers the mouth of the chimney. However, this does not always save from the negative influence of the wind. To solve this problem, a deflector is installed on the chimney.

What is it needed for

The main thing in calculating the parameters of the chimney is to create sufficient traction that can remove combustion products from the combustion chamber of a solid fuel stove due to a significant pressure drop. For this, the required channel diameter, material, section shape and pipe height are selected.

A strong wind is capable of blowing air into the mouth of the channel, thereby preventing the exit of exhaust gases. An extreme case is the effect of draft suppression, when the boiler exhaust is not able to overcome the resistance and flows back into the room, which is basically unacceptable.

It is not enough to close the mouth of the chimney from external air currents, but no optimal designs for this. It is better to use the power of the wind itself in order to avoid negative consequences and even further increase traction, which is what the deflector does well.

Principle of operation and device

The work is based on Bernoulli's law, which is true for liquids and gases. When gases move in a channel with a decreasing cross section, their velocity increases, and the pressure exerted on the channel boundaries decreases, and a rarefaction occurs. If there is a connection between the surrounding space and the rarefaction zone, then the fast flow carries along the substance from the outside.

A deflector is a device that provides air flow or its passage through a narrowing channel, in which a rarefaction zone appears directly near the mouth of the chimney. Gases leaving the chimney begin to be sucked into the area of the discharged gas. As a result, the wind, which could cause thrust suppression, on the contrary, begins to increase it.

You can achieve a 20% increase in thrust even with the simplest deflector design. For solid fuel stoves and boilers, this means better burning of coal, firewood or briquettes, better heat transfer and, as a result, increased plant efficiency. The problems associated with the attenuation of the flame or the return of exhaust gases to the interior of the room are eliminated.

The device additionally prevents debris, snow and rain from entering the channel. This is partly due to the presence of the deflector housing, partly because the supported thrust counteracts clogging.

Kinds

The design is not regulated in any way. Any design that does not cause additional resistance and creates a vacuum at the mouth of the chimney increases traction and justifies its operation. There are several types of deflectors that have become widespread due to their practicality and reliability:

TsAGI deflector
Disc deflector, Astato
Round "Wolper"
Grigorovich deflector
H-shaped deflector

Each of the listed types perfectly copes with the tasks. The differences are overall dimensions and susceptibility to wind of different directions. The disadvantage of almost all types is that in the absence of wind they themselves resist traction.

Several more devices operate in a similar way: a turboprop tip (rotating deflector) and a weather vane with a screen.

The deflector is made of galvanized steel, copper and stainless steel. The main requirement is high resistance to corrosion, because the device will be installed on the chimney, where repair work will be extremely difficult, especially when the heating boiler or furnace is running.

For ventilation ducts where high temperatures are excluded, polymeric materials may be used, or polymer coatings for metal structures.

TsAGI deflector

The most common type of deflector. A short channel of larger diameter is fixed over the mouth of the chimney, which will form a diffuser. The wind flows around it from all sides. On the sides there are zones of increased pressure. At the front point and at the rear in the lower and upper sections, a vacuum occurs, which contributes to an increase in traction.

Swirls appear along the upper edge of the diffuser, which can create an obstacle to the exit of gases. In addition, there is no protection of the mouth of the chimney from debris and precipitation. As a solution, a protective cap in the form of a cone is fixed above the mouth.

poppet

An easy-to-use deflector that provides the desired effect in the most visual way. The two main parts of the device are the chimney cap, Bottom part, which is closed by a cone facing the chimney and a ring from which a truncated cone is formed and put on directly on the very edge of the chimney.

The result is a simple and efficient design. Regardless of which side of the world the wind blows from, it hits a point above the mouth, where the cones form a narrowing channel, which causes rarefaction and pumping of gases from the chimney.

Round "Wolper"

In principle, the design is identical to the TsAGI deflector, only the cover for protection against debris and precipitation is located above the diffuser. The cover is in the form of a cone, which additionally creates a vacuum in the upper part.

Grigorovich deflector

It is a further development of TsAGI and is better suited for installation in places where ascending air flows predominate. In addition, it ensures optimal operation even in the absence of wind, without creating noticeable resistance. In the lower part, the deflector is a high truncated cone with an extension in the lower part. It starts at the mouth of the chimney with an overlap of up to a third of its height.

Gases from the pipe itself enter the narrowing channel of the diffuser, and thereby cause a vacuum. Rising currents of external air further enhance the effect, increasing traction.

H-shaped

A non-trivial design that has proven itself well in industrial facilities and powerful boiler houses. A transverse branch pipe of identical diameter is fixed at the mouth of the chimney. For mating in the center of the pipe there is an insert that provides a tight connection.

Two more segments are fixed along the edges of the transverse horizontal pipe, resulting in a structure in the shape of the letter "H". It is no longer necessary to use protective caps, because the mouth of the chimney is securely closed by a horizontal element, and the side pipes are through and do not prevent the passage of precipitation.

This design, in any direction of the wind, provides a uniform flow of air directly near the mouth or along the side channels, which already creates additional traction.

Installation

The deflector is supposed to be installed on the chimneys of furnaces and boilers running on solid fuels, in some cases also on liquid ones. However, it cannot be installed on gas boilers. This is due to the inconstancy of the generated thrust, because it directly depends on the strength of the wind. If the draft is too high, the fire at the outlet of the injectors in the combustion chamber may go out. All this is indicated in normative documents SNiP 2.04.05-91, SP 7.13130.2009.

For effective operation, the deflector should only be installed if the mouth of the chimney is located above structural elements roofs. For pitched roofs lower position is allowed. So at a distance of 1.5-3 meters from the ridge, installation is possible on a level with it. When located further than three meters, the angle between the plane of the ridge and the conditional straight line between the ridge and the mouth of the chimney should not exceed 10 degrees. For flat roofs enough to go beyond the main building envelope.

You can make your own deflector. The easiest way is to make a variant of TsAGI or Volper. The calculation of the dimensions of each of the elements is carried out, starting from the inner diameter of the chimney. If it is denoted as d, then it turns out:

diffuser diameter - 1.2-1.3d;
deflector height 1.6-1.7d;
protective cap width - 1.7-1.9d;

The height of the diffuser is taken equal to half the height of the entire deflector. In its lower part, a clamp is equipped, which will be mounted on the mouth of the chimney. A diffuser is fixed to it with the help of 4-6 strips of galvanized steel. A protective cap is attached to the latter with the help of the same strips. The gap between the diffuser and the cap is 0.2-0.3d.

To increase efficiency, it is possible to build a nozzle with an external opening at the mouth of the chimney, and preferably on the deflector mounting ring. The height of the nozzle can be 0.1-0.2d, the outer diameter should increase by about the same (1.1-1.2d)

This is the easiest design to make. All elements are easily cut from sheet steel with a small amount of scraps.

In order not to make a mistake with the markup, it is better to first cut out the shape of the blanks from cardboard, and then transfer them along the contour to a sheet of metal.

All elements of the deflector are connected by folding, rivets or welding. Thereafter finished structure can be mounted on the mouth of the chimney and checked in operation. To ensure reliable and effective work deflector, it is better to purchase a finished design with ideally calculated parameters and dimensions.

All chimneys, regardless of the material of manufacture and the configuration of the chimney structure, are equipped with special devices to protect the chimney from environmental influences, called deflectors. Read the instructions on how to clean the chimney from soot.

What is it and what is it for?

The chimney deflector is structurally metal product, as a rule, a cylindrical shape, resembling a kind of cap. The deflector performs several basic practical functions, additionally a decorative function (it is used as a chimney decoration). The deflector protects the chimney from turbulence, thereby creating optimal conditions for high level traction under significant wind loads. In addition, the deflector is equipped with an additional insert (plate) that prevents precipitation and foreign objects from entering the chimney.

Technical specifications

Deflectors can have the most different shape pommel:

deflectors can be flat;
deflectors can be conical;
deflectors can have a gable roof, etc.

Types of deflectors

The deflector for the chimney, used to increase the draft, consists of a cylinder, a diffuser, an umbrella. The design of the deflector is designed in such a way that in any direction of the wind, take it to the side, while providing effective removal fuel combustion products.

Weather vane - a deflector on the chimney has original design, allowing the deflector to rotate when exposed to wind currents.

Turbine deflectors for chimneys, unlike weather vanes - deflectors rotate only in one specific direction, converting and using wind energy to increase traction in the chimney.

When installing a deflector on a chimney made of brick, an additional installation of a special transition with an overflow in the right direction will be required, which allows you to connect a square or rectangular chimney with a deflector having a round shape.

For chimneys of gas boilers, the best option would be to install a rotary (turbine) deflector.

H - shaped deflector on the chimney is effective in gusty winds characteristic of the area.

Additionally, the chimney deflector can be equipped with a spark arrester, which is a metal mesh located under the deflector cover.

When installing an umbrella - deflector on the chimney, make sure that it is equipped with a dripper that removes the resulting condensate outside the chimney pipe.

Photo

There are practically no restrictions for installing a deflector on a chimney. The deflector can be installed both on individual chimneys and on chimneys of collective chimney systems.

In a situation where there is a risk of fire roofing material, from a spark falling out of the chimney, it is recommended to install deflectors equipped with spark arresters.

Device and calculation

The deflector device has its own design features, which should be followed when calculating the parameters of the product, otherwise the deflector will not perform its functions based on aerodynamic laws.

When calculating the dimensions of the product, it must be borne in mind that the height should be 1.6 - 1.7 parts of the inner diameter of the chimney, the cap width should be - 1.9 parts, the diffuser width - 1.2-1.3 parts.

How to make?

The manufacturing process of the deflector can be divided into several stages:

preparation of the pattern (a scan of the main elements of the deflector is applied to the cardboard according to the calculations);
patterns are transferred to sheet metal;
details are cut out;
cut parts are interconnected, either by welding or by means of fasteners;
in addition, it is necessary to make steel brackets, they will be needed to mount the cap on the surface of the chimney;
a cap is assembled from parts (it is recommended that the cap be made in the form of an inverse cone).

chimney deflector cost

The prices for the deflector vary, depending on the diameter of the product, from 400 rubles per piece. up to 1,500 rubles/piece

Video

Watch the video description of the deflector - spark dye on the video:

During the research work it was found that equipping the chimney with a deflector increases the efficiency of the chimney system by twenty percent.

If you look closely at the chimneys and ventilation pipes of residential buildings, then the variety of chimneys on them (deflectors, weather vanes) is amazing. But the main task of the deflector is not to decorate the chimney, but to increase and stabilize the draft depending on the weather, and thereby improve the efficiency heater and reduce heating costs. A baffle on the vent pipe can provide non-volatile (and free) supply and exhaust ventilation, see below. But at the same time, there are also enough opponents of installing deflectors on the pipes of residential buildings, and they give weighty arguments in their favor. The purpose of this article is to help the reader figure out in which cases it makes sense to put a deflector on a chimney or ventilation, then how to choose the right one or make it yourself.

The most important question

Before choosing or making a deflector for a pipe, you need to decide - is it needed at all? The deflector can freeze, drag on with soot or soot (coke), clog with fallen leaves, wind-blown debris or dust. In any of these cases, if the deflector is on the chimney, the inhabitants of the house risk getting burned. The deflector does not increase the efficiency of the furnace or boiler much, but it requires regular inspection and cleaning. At least once every 3 months for solid fuel stoves and at least once every six months for gas, liquid fuel or pyrolysis stoves and boilers. For more information about the dangers that an unsuitable deflector can entail on a pipe, see the video:

Video: why are deflectors, umbrellas and weathercocks on the chimney dangerous?

Therefore, if you have an old wood or coal stove, but the draft is unimportant and the wind blows into the chimney, instead of a complex deflector, it is better to put a simple chimney, for example. umbrella or tent. And in other cases, you need to carefully figure out which particular deflector is needed for this particular stove / boiler with this particular chimney. It is also important not to confuse a smoke deflector with a ventilation one - small traders and the authors of some popular publications do not see or do not see the difference between them.

deflector evolution

Deflectio in Latin means "I reflect" in the sense of "I discard". Not directed in a certain way, like a reflector, but only to the side. Chimney cap made of skins, large shells, etc. already set by primitive people to avoid wind blowing into the chimney.

The role of the deflector in creating thrust, its stabilization in spite of the vagaries of the weather and the ability of the deflector to increase the efficiency of heat-generating devices were first seriously thought at TsAGI almost 100 years ago on the instructions of the newly hatched Soviet government. Before that, heat engineers tried to improve chimneys for this purpose. Have you seen in old photographs the huge pot-bellied, like an inverted pear, chimneys of American steam locomotives or the long thin ones, with a rosette at the top, of English ones?

At TsAGI, the venerable aircraft designer D. P. Grigorovich took up deflectors in a creative collaboration with A. F. Volpert, who was fluent in mathematical apparatus. The latter is also, and even more, known for his work in the field of radio engineering (Volpert-Smith diagram, etc.). Together and separately, Grigorovich and Volpert developed several types of deflectors for various purposes, therefore, different deflectors of Grigorovich, Volpert and Volpert-Grigorovich are described in the specialized literature.

Grigorovich began by aerodynamically correctly calculating the usual chimney-umbrella, pos. 1 in fig. This has already significantly improved the performance of the device; Grigorovich's cone - remember, it will come in handy. Volpert proposed to equip the deflector-umbrella with an aerodynamic diffuser skirt (pos. 2), but the deflector remained aerodynamically imperfect, see below. It was supplemented with a streamlined body of revolution instead of a cap and a cylindrical body-shell. In the end, after repeated blows in the wind tunnel, the TsAGI deflector (pos. 3) was presented to the government commission, which fully met the issued TOR and greatly overlapped it.

The TsAGI deflector is still the most common in the world due to its technical excellence. There are modifications for different purposes, see below. But other developments of Grigorovich and Volpert were not in vain - most of the models of modern smoke deflectors are being developed on their basis. Which of them is more suitable for what, we will talk about this later.

Types and schemes

All the variety of trade names of smoke deflectors fit into a limited number of design types and aerodynamic schemes. First of all, according to the interaction with the natural draft of the chimney, the deflectors are divided into:

Active - with a built-in working smoke exhauster. To ensure the specified characteristics of the deflector, the smoke exhauster must work constantly while it burns in the furnace.
Active-passive - a low-power smoke exhauster in case of emergency: complete calm, storm, excessively intense firebox, etc. Minimum allowable specifications chimney are provided even when the exhauster is off.
Passive-active - the deflector creates a small amount of its own thrust in a non-volatile way.
Passive - there is no deflector own draft.

Active deflectors as volatile and not optimal for house heating appliances low power we do not consider further. Of the active-passive ones, one will be considered, designed for a low-power 12 V fan and suitable for DIY.

According to the aerodynamic design of the chimney deflector, it is possible to perform the following. like this (top of the picture):

Aerodynamically imperfect (incomplete) - in the space occupied by the deflector there is a “pocket” - a winding area in which accumulation of air, flue gases or their mixtures is possible;
Aerodynamically full open - there is no wind pocket, but the wind has free access to the deflector working space;
Aerodynamically perfect closed - there is no wind pocket, the wind does not have free access to the working space;
Weather vane deflector (see below);
Vortex deflector.

An aerodynamically perfect closed deflector is the most complex structurally and technologically, but it has a huge advantage: due to the heating of the shell, aerodynamically perfect closed deflectors almost all produce their own non-volatile thrust. This is the only passive type of deflector that can increase the natural draft of the chimney at full calm.

Note: an aerodynamically perfect closed deflector is the TsAGI deflector mentioned above. This aerodynamic scheme was invented in TsAGI.

Vortex deflectors are easily recognizable by their "torn" design with sharp protrusions. In their aerodynamics, as in vortex aerodynamics in general, there is still much that is unclear (the Navier-Stokes equation was solved in general view only 2 years ago). It is impossible to predict the behavior of a swirl deflector under any external conditions with any chimney. Therefore, vortex deflectors are not considered further. To believe or not to their manufacturers is your own business.

Aerodynamics

Schemes of flue gas current in deflectors in publicly available sources are sufficient. But from the point of view of the homeowner and the master character is more important interaction of the deflector with the natural draft of the chimney and the wind in the wake. aspects:

Will the deflector worsen the initial draft?
Is the deflector able to increase the initial draft in calm?
To what extent and in what way does the deflector increase wind loads on the pipe?
How prone is the deflector of this scheme to icing / clogging and easy to clean?

The wind is then better considered not on the meteorological scale, but on the basis of a rough gradation of force and the dynamics of the velocity field:

calm;
weak / medium (moderate) - up to 6 points on the weather scale;
strong - 6-8 points;
very strong - over 8 points;
gusty - the wind of any strength is really gusty, or sharp (very sloping up or down), or swirling.

Figure 1 gives an idea of the aerodynamic properties of passive smoke deflectors. above.

simple cap

An ordinary chimney chimney in the form of an umbrella, if it is made in the form of a Grigorovich cone, is not so bad:

With a massive heat-intensive chimney, it keeps draft within the limits allowed for a wood-burning / coal-burning stove in an even wind up to a violent storm (10 points).
In any wind up to a hurricane, it does not create destructive loads on the pipe; Rather, he will break and fly away.
Structurally simple.
Slightly coking and clogging, easy to clean as part of the annual inspection and maintenance of the chimney.
Due to imperfect aerodynamics, it is not very sensitive to the configuration of the umbrella. If the house is in the wind, the chimney-umbrella can be made tented (see the figure on the right), which simplifies the work and gives great opportunities for its design.
With a 2-3 channel chimney (see below), it provides technical indicators (except for an increase in draft in calm weather) no worse than an aerodynamically perfect closed deflector.

The disadvantages of an imperfect chimney deflector are also quite serious:

In calm weather, it reduces the initial draft the stronger, the more intensively the stove is heated. What is especially dangerous in a harsh, quiet winter: the stove can choke and puff with fumes.
On the strong wind is able to create excess draft, which drastically reduces the efficiency of compact channel stoves (for example, Dutch ones by 2.5-3.5 bricks) and fireplaces.
In very strong / gusty winds, blowing into the pipe and the appearance of reverse thrust are not ruled out.

In general, an imperfect deflector-umbrella is the optimal chimney for a brick chimney of a properly built and well-maintained house solid fuel stove, operated in places where hurricanes and storms are extremely rare. There are ways to make the chimney-umbrella non-inflatable (see below), but they complicate it to the point that most often you have to choose an aerodynamically complete or perfect deflector.

Open

The aerodynamically open deflector does not reduce the initial thrust and in any wind keeps it within the limits permissible for furnaces and boilers for solid, liquid fuel and gas. It freezes quite strongly, cokes and litters, but is easily accessible for cleaning. Its disadvantages are:

A streamlined body of revolution instead of a cap is a technologically complex assembly.
The resulting vector of wind loads is such that the aerodynamically open deflector tends to collapse the pipe, while the umbrella tends to fly off it itself.
In a wind stronger than 8 points, the lateral load on the pipe increases sharply and then grows according to a power law.
It poorly extinguishes the dynamic load from gusts of wind, therefore, an open deflector cannot be placed on a brick pipe.
Unsuitable for pyrolysis heat-generating devices: in a strong wind, it immediately sucks out pyrolysis gases and the furnace / boiler goes out.
Little suitable for design: blotches and figures spoil the overall aerodynamics. The only place where decorations can be placed is the upper pole of the body of rotation and the lower edge of the diffuser (see below).

Note: At one time, we and the USA conducted experiments on the use of open deflectors on steam locomotives to increase efficiency at low speed. The result is deplorable - at the middle stroke, a tongue of flame was shown from the pipe, and none of them could accelerate to design speed.

In general, the aerodynamically open deflector is suitable for all types of heaters, except for pyrolysis ones. Provided that the deflector is inspected and cleaned at least once every 2 months, and the draft is checked before each firebox. Very well suited for chimneys with insufficient draft and especially for sauna stoves: there were no cases of burning out in baths due to an open deflector. Correctly heating a bathhouse is not an easy task, and checking the deflector will not noticeably complicate it.

Note: there are types of open deflectors that practically do not create side loads on the pipe and are suitable for fragile ceramic and glass chimneys, see fig. on right. However, in open body rotation accumulates dust, debris and soot, which spoils the aerodynamics of the device, and it is difficult to clean it. Therefore, manufacturers recommend such products only for gas boilers in places with not very dusty air.

Perfect

The advantages of an aerodynamically perfect closed deflector are partially indicated above. Moreover:

The aerodynamically perfect closed deflector provides draft stability in any external conditions, sufficient for any household stoves and boilers.
It does not clog and does not freeze inside, and frost and dust from the outside have little effect on its operation.
With minor modifications, it is suitable for use as both smoke and ventilation non-volatile, see below.
It perfectly dampens the dynamic load from gusts of wind and is therefore suitable for installation on pipes made of any material.
2-3-4 chimneys can converge into one oval, triangular or square shell.

The disadvantages of a closed deflector are not so significant:

The lateral force on the pipe in the wind up to a strong one gives more than the open one, but then with the strengthening of the wind it grows linearly, i.e. the pipe under the open deflector can always be reinforced or strengthened with braces.
It is quite complicated structurally and technologically.
Unsuitable for design: any blotches and figurines spoil the overall aerodynamics, and the coloring only enhances the utilitarian look of the deflector.

Technological tricks

The first rule - do not make chimneys like gable roof or cylinder vault (see figure on the right). Such are suitable for their intended purpose only for mobile devices, when the axis of the umbrella can be arbitrarily oriented along the wind. Or as decorative on a false chimney. There is such a fashion in houses with biofireplaces. And in other cases, the thrust will walk according to the will of the elements up to the reverse.

Further, in order to make a deflector for the chimney with your own hands, you need to master some of the techniques of tin work. First of all - the connection of sheets in a fold (fold), or folding, see fig. below. Most often, the parts of the deflectors are connected by a single lying fold, but for umbrellas of imperfect deflectors in decorative purposes sometimes a double standing seam is used.

Umbrella round:

Umbrella pyramidal (hipped) with a top in the center:

Umbrella elongated faceted:

Transition from a square to a circle (square inside a circle):

Very important for closed deflectors for small furnaces and boilers, see below.

Moving from circle to circle:

All these patterns can be built using only a ruler and a compass - a goat's leg (into which a pencil is inserted. Well, for those who are inclined to in-depth study of the basics, before getting down to business, we give a selection of projections and formulas for accurate construction of sweeps of parts. Pay attention to the elongated umbrellas: they are placed on 2-3 flue chimneys.Smoke channels, each of the minimum cross section allowed for a given heater, are placed in a row.The probability of blowing out 2 channels at once is extremely small, and all 3 are practically absent.

Here in fig. - data for constructing a truncated cone, which are more than enough in deflectors. The initial data are the height of the cone H, the radii of the top and bottom R1, R2. Pay also attention to the inset marked in red: this is a development of the same Grigorovich cone. The forming angle (in this case 30 degrees) is found as φ = arcsin(H/r), where H is the height of the cone and r is the radius of the base. The radius R is defined similarly to L for a truncated cone, but H and r are squared. However, for those who have not forgotten the Pythagorean theorem, this is already clear.

After the cones, it will not be difficult to deal with the development of a single-center tent, see fig. Only one “but”: the allowance on the pattern example (on the right in the figure) is given per single riveting (for strength) of the soldered seam.

To connect metal up to 0.6 mm thick into a single fold, the allowance on one side must be taken 20 mm, and on the other 21 + 2 + 20 mm. If the metal is 0.6-1.5 mm, then 30 and 31.5 + 3 + 30 mm, respectively. But, generally speaking, a seam soldered and riveted at the edge is easier to make, it looks neater and resists corrosion better than a seam. If the roof is covered with iron, then, of course, riveting and soldering the sheets is simply technically impossible. But the deflector umbrella is another matter. Collect it on soldering with riveting as follows:

Mark and cut out the scan;
Drill holes for the rivet;
The sides (wings) of the allowance are bent inward at 90 degrees;
Rivet the edge;
Through the wooden lining bars, the sides are compressed with clamps;
Solder the seam.

In a similar way, a sweep is built and a hip tent (umbrella) of the chimney is assembled, see fig.

And, finally, the most difficult detail: the diffuser of an aerodynamically perfect closed deflector, which is also an adapter-skirt from a square to a circle (circle inside) for installing a chimney-umbrella on a brick pipe. The construction rules are not complicated (see the figure), but they require accuracy and accuracy in work.

Note: additionally equalize the thrust of the open and imperfect deflectors on round pipe, and it is also possible to reduce the probability of blowing into the latter to an insignificant extent if the generatrix of the diffuser / skirt is bent inward, see fig. But the work is so complicated - after assembling the adapter from circle to circle, it must be knocked out on a block of solid wood.

Constructions

Now let's see what is possible and how to make a deflector on the chimney yourself. The easiest way to start is with an imperfect umbrella deflector; its capabilities are much wider than it might seem, and the materials are not very hard work little is required.

What can an umbrella do?

In the climatic conditions of the Russian Federation, a deflector-umbrella on a chimney most often turns out to be enough, especially since no waste was also noted through his fault. But - if the chimney-umbrella is made correctly. The most common mistake is to raise the cap too high on the racks. It will not help to return 100% of the original thrust, but the likelihood of blowing into the pipe increases dramatically.

The correct dimensions of the deflector-umbrella on the chimney are given on the left in fig. For pipes with a clearance of 100-200 mm, they decrease proportionally, and then the value of H1 increases 1.3 times for pipes 150-200 mm and 1.6 times for pipes 100-150 mm.

On the right in fig. the dimensions of the non-inflatable deflector-umbrella are given, but in the conditions of the Russian Federation it is better to put this on the ventilation pipe natural ventilation, because the grid is quickly overgrown with soot or flue gas condensate, and then dust adheres very well to it.

It also does not blow out, retains the original thrust and even slightly increases its two-story deflector-umbrella. The scheme of its action is given in pos. 1 next rice.:

For chimneys of low-power household stoves / boilers (up to approx. 40 kW), it can be simplified by making the floors the same, pos. 2. Each floor is a Grigorovich cone cut in half in height (see above); the distance between floors is equal to the height of the floor. The upper floor is gable, i.e. the cut top of the cone is closed with a blind lid. A 3-story umbrella for a ventilation pipe (pos. 3) is less likely to freeze over and clog less than an umbrella with a net. For pipes 130-200 mm, the dimensions change proportionally. And, finally, the Kiryushkin deflector (pos. 3; all cones - Grigorovich) is used mainly as an active-passive one - a low-power smoke exhauster for 12 V 100-200 mA is placed under a small cone.

TsAGI

Before taking on an aerodynamically open deflector, let's see how the most advanced TsAGI deflector is modified for a private house. Its original design was designed primarily for industrial facilities and then for apartment buildings.

Drawings of 3 variants of the TsAGI deflector are given in fig. The dimensions of the original industrial version are shown at the top right. Not completely, because it is designed for a strong pipe and certainly not for a sandwich chimney. For the chimney of a private household, the Khanzhenkov deflector operating in the same way is more suitable (on the left in the figure). It gives less horizontal wind load and can be inserted into the pipe as described below.

And on the right in Fig. - dimensions of the TsAGI ventilation deflector. It can be turned from passive into passive-active by painting the shell with black blacksmith's stalemate or other paint that well absorbs the thermal radiation of the earth and the objects surrounding the house. Fans in the vents of the house ventilation system must, of course, be left, but they will have to be turned on occasionally. How to make a TsAGI deflector with your own hands, see video

Video: do-it-yourself TsAGI deflector from metal tiles

Note: a ventilation deflector is not such a luxury as it might seem. When the wind blows into the ventilation, it is cold in the bathroom, and kitchen fumes and toilet smells are carried around the house. Flapper valves do not solve the problem - it slammed shut, it was stuffy in the bathroom and kitchen.

What is obtained from the cones

From deflectors open type the most accessible, and, for the entire range of technical indicators, the Volpert-Grigorovich deflector is optimal for private households. Although, only they themselves knew how much it actually contained.

The canonical (original from TsAGI research) proportions of the Volpert-Grigorovich deflector are given in pos. 1 fig.:

On the left - a modification for an asbestos-cement pipe, which holds longitudinal loads well, but is fragile across. The height of the upper cone forming the body of rotation, doubled, gives a large lifting force, tending to rip the deflector off the pipe, but a tight collar will keep it in any wind. For pipes 130-180 mm inside, the dimensions change proportionally.

Note: for another version of the self-made Volpert-Grigorovich deflector, see next. video clip:

Video: Volpert Grigorovich deflector to increase draft in the furnace

weathercocks

Deflectors for pipes - weathercocks are also called weathercocks. Sometimes all chimneys in general are called that, but this is not true, because. weather vane by definition is a rotary device.

The deflector on the pipe - the weather vane can be made rotary self-orienting and rotating. The latter are also called turbo deflectors, and self-orienting smoke teeth, which is also not true. Smoke tooth - part of the chimney of an English fireplace. The weak point of all wind vane deflectors is the bearing. It is very easy to clog and soot, and the seals are subject to increased wear. Therefore, it is necessary to inspect the deflector-weather vane at least once every 2 months. But the deflector-weather vane itself is almost never overgrown with the main enemy of all fixed deflectors - icicles.

Pipe deflectors - weathercocks

The multi-bladed deflector-weather vane (pos. 1 and 2 in the figure) gives stable draft in the wind up to 9-10 points with slight loads on the pipe, so it can be installed on sandwich, ceramic and glass chimneys. A single-blade deflector-weather vane in a strong wind heavily loads the pipe, so it must be strong and the house should be located in a place where the storm wind does not clear up. But a single-blade deflector-weather vane is easy to arrange in the form of a bird (pos. 3 and 4).

Turbo deflector (pos. 5) - remember and do not trust anyone - not smoke! It is ventilated or for gas boilers with electric ignition. The turbine is rotated both by the wind and by the air flow in the pipe, and a correctly made turbine, as in some types of wind engines, is self-winding: the weakest initial thrust or a slight breeze is enough for the turbine to spin and draw air, and it will stop only when the thrust and the wind will stop completely. In the ventilation system of a house with turbo deflectors, you have to turn on the fans in the vents, as they say, once a year, not every year. Unfortunately, the turbo deflector is easily drawn in by dust and debris from the air, so it should also be checked at least once every 2 months.

The technical properties of the turbo deflector are the same as those of the multi-bladed self-orienting deflector, but it loads the pipe even less. It is quite possible to make a turbo deflector with your own hands, see the video below.

Video: do-it-yourself turbo deflector

How to install a deflector

It is possible to put a deflector on the pipe only if the chimney is made exactly according to the rules of SNiP 41-01-2003, pos. 1 in fig. below. It is highly desirable that the pipe on which the deflector will be installed is located on the leeward slope of the roof relative to the direction of the prevailing winds. For reference: leeward means opposite to the direction the wind is blowing from.

It is certainly possible to attach a deflector to an otter (upper extension of a brick pipe) only if the pipe was originally designed for the deflector. If not, or there are even the slightest violations in the pipe laying, the deflector must be attached to it as shown in pos. 2 pic:

A strong sleeve (glass; square-to-circle adapter) C is inserted into the pipe;
The glasses are fixed with blind anchors A at a level not higher than the bottom row of the otter masonry and with embedded pins Z into the grooves at the mouth of the pipe. Anchors and mortgages are bricked up with cement-sand mortar from M200;
A diffuser / skirt D with a cornice (shine) K is put on the glass. Mandatory for a deflector of any scheme, incl. imperfect!
The diffuser is attached only to the masonry with small anchor bolts. Not with self-tapping screws in plastic dowels! The skirt / diffuser is not attached to the glass!
On the collar (upper edge) skirts / diffuser firmly fix the working structure of the deflector.

Only with this method of fastening, the deflector will never loosen an old and / or brick pipe not designed for it.