Emission of flue gases from mounted boilers. Coaxial chimneys for wall-mounted boilers. Installation rules, connection diagrams Separate smoke exhaust
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The occurrence of a fire is dangerous not so much due to the presence of an open flame, but rather due to smoke in the premises. Even a small fire can cause so much smoke that it becomes difficult for people to escape. The presence of combustion products in the air makes breathing difficult, disorients in space, and causes panic. These threats require appropriate ventilation systems, providing effective smoke removal, as well as facilitating the prompt solution of problems that arise. Such systems exist and are actively used in different buildings, industrial workshops or other structures.
Smoke removal system - a specialized complex ventilation equipment, designed for the prompt removal of combustion products from premises, clearing smoke evacuation routes for people and facilitating proper organization measures to eliminate the fire.
The main areas of coverage of the system are stairwells, elevator shafts, and corridors along the evacuation route. The following functions are performed:
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The possibility of fire spreading is reduced.
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The amount of smoke is reduced.
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The possibility of normal fire extinguishing is ensured.
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The air temperature decreases.
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Monitoring and notification of a fire is carried out.
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Opening hatches, valves, windows for efficient removal of combustion products.
Smoke removal complex – extended and a complex system, operating according to different schemes, allowing for redistribution air flow as needed.
Design and device
Smoke exhaust ventilation consists of the following components:
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Smoke extraction fans. Carry out exhaust or inflow fresh air into smoky rooms.
Expert opinion
Fedorov Maxim Olegovich
Important! In any case, all possible means are used to as soon as possible eliminate smoke and restore a normal indoor microclimate that meets sanitary standards.
Equipment included in the complex
Devices with appropriate characteristics are used as smoke removal fans. Operating conditions require a high heat resistance category - from 400°C to 600°C. Impellers can be made from of stainless steel or possess protective coating, protecting against the effects of aggressive combustion products.
Smoke exhaust ducts are made of carbon or galvanized steel and have increased requirements for tightness – category “N” (normal version) or “P” (tight).
The smoke exhaust hatches used for the system have a normally closed position and open upon command from sensors or from the control panel. All elements must be designed to operate under high temperatures and in an aggressive environment.
Smoke removal calculation
System calculation is a complex multi-stage task. All possible channels for the removal of gases or combustion products are determined - from existing corridors, stairwells etc. to new, additionally installed ones. The performance of the fans is calculated based on the size of the channels or the volume of the rooms; the number of smoke exhaust valves is determined based on the number of rooms and corridors, as well as fire dampers. There is no single calculation method, since the configuration of rooms and air ducts for smoke exhaust may be different.
The calculation method is complex and requires the participation of trained specialists. If for some reason online calculators are not suitable for solving the issues that have arisen, then you should contact a specialized organization and order a calculation from them. It will be necessary to have specialists examine the existing premises, possible routes for the removal of combustion products, determine the procedure for evacuating people, etc. All these calculations must be based on the requirements of SNiP and comply with fire safety and sanitary standards.
Expert opinion
Heating and ventilation engineer RSV
Fedorov Maxim Olegovich
Important! Independent calculation of a smoke removal system means a high risk of making mistakes due to lack of experience.
Exploitation
The established system for removing combustion products is operated in accordance with the requirements of regulations or SNiP. A schedule of equipment checks is drawn up and all necessary measures to maintain all elements in working order. The difficulty is that the system does not operate constantly; idle equipment has a high probability of failure. The responsibility of the complex is great; saving on maintenance and control measures is unacceptable.
Smoke removal systems are often more important than systems fire extinguishing, since even with a small fire that does not threaten any material values or people, the amount of smoke may be critical and lead to difficulties in carrying out fire extinguishing measures or even casualties. Poisoning by combustion products causes panic and disorientation, when a person does not understand which way he should run. The responsibility is high and requires appropriate attitude on the part of management and staff.
How does a smoke exhaust valve work?
Recently, you can hear a lot of discussions about the possibility of installing mounted 2-circuit boilers in apartments multi-storey buildings, both existing and new buildings. The advantages of such heat supply are obvious - individuality in everything: in the choice of boiler, in temperature hot water and heating, in payments for gas, independence from neighbors and heating networks. But there are also limitations to installing them, especially for existing homes.
Thus, the main problem is the supply of gas to boilers, since initially the houses were designed with a gas supply system designed only for gas stoves. The house gas pipeline can be redesigned through the efforts of the residents themselves. This problem can be solved, although it is difficult to organize from the point of view of the abilities of each of the residents. Relaying a gas pipeline is also relatively easy: all gas pipeline pipes are laid outside, and the intersection with the walls is done in sleeves. So there is no need to spoil the design much.
Another thing is the removal of combustion products from boilers. A number of difficulties already arise here, which in some cases are almost impossible to solve. For example, for boilers with open camera combustion in the kitchens of existing high-rise buildings there is no individual chimney and air flow for gas combustion. And for boilers with closed camera combustion and a coaxial chimney (nothing is provided for a separate chimney), that is, when combustion products are emitted through outer wall in the kitchen, neighbors complain. And there’s a reason: the neighbors above get a good portion flue gases, the neighbors below are dripping condensation in winter, and if someone is drying clothes nearby, it will smell delicious flue gases. This leaves a limited number of supply options. quality heat existing high-rise buildings:
· Replacement of existing columns or boilers, if any, with new ones;
· Installation of house heating units with apartment-by-apartment heat meters;
· Electric boiler and boiler, if in-house electrical networks and personal finances allow;
There will be no problems for new buildings if everything is foreseen and designed in advance. Next we will look at everything possible options smoke removal from wall-mounted boilers, as with atmospheric burner, as well as with a fan.
There are several options for supplying air to the boiler for the combustion process and removing flue gases from the boiler. When choosing one, you must take into account the performance of the boiler, the safety of the occupants and all applicable regulatory requirements.
The optimal solution for apartment heating in new multi-storey buildings is the installation of boilers with an open combustion chamber, since in built-in brick chimneys in the kitchens a good natural draft is created for smoke removal (except for the 9th floor, if there is no technical floor above). In this case, the air flow into the kitchen must be ensured taking into account the needs of the boiler. It must be said that many projects still do not provide air flow into residential buildings, and the phrase “inflow is unorganized, through leaks in windows and doors” is written. With modern sealed double-glazed windows there are no leaks, and through external doors it is unlikely that residents will be pleased with the flow of outside air in the amount of 3 times the air exchange for the kitchen (with gas stoves) and 2 times for the bathrooms. The ideal solution for the inflow there is a hole under the kitchen window, behind the radiator, with which it is heated in winter. Kitchen is production room with gas and water, so an inlet hole in it is simply necessary. And the issue is resolved.
If the task is to exclude the intake of combustion air from the room, then it is possible to install boilers with a closed combustion chamber and a fan. But here it is necessary to provide a number of measures. The fact is that the operation of the fan in such boilers is controlled by a differential pressure switch, which will turn on the fan only when the pressure difference between the air intake and flue gas exhaust pipes is in the range of 52 - 62 Pa. This is done for the safety of the smoke removal system, since if the pressure difference between the pressure and suction pipes is not ensured, this may negatively affect the operation of the fan and, as a consequence, the entire smoke removal and combustion air supply system.
Possible smoke removal solutions for boilers with a closed combustion chamber. According to the principle of operation, they can be divided into two types: coaxial chimney and separate chimney. The better of the two is coaxial because supply air is heated by the exhaust flue gases, which certainly affects the efficiency of the boiler (efficiency - 92%) and environmental indicators (NOx - class 3). Installation of such a chimney can be done in two ways:
* conclusion coaxial pipe(max – 3 m), immediately behind the outer wall of the room in which the boiler is installed (Fig. 1);
* connecting a coaxial pipe to a coaxial chimney built into interior wall buildings (Fig. 2). In our case, such a chimney is suitable only for the 9th floor, since it has a height limitation (max. 5 m), due to the power of the fan. 
Rice. 1 Smoke removal option C12 
Rice. 2 Smoke removal option C42
A separate chimney is less efficient. In private houses it is used less frequently, since, according to DBN V.2.5.20-2001 “Gas supply”, the room in which the boiler is installed must have an outer wall and a window in it. Since there is an external wall, it is easier to install a coaxial chimney without leaving the cash register.
In multi-storey residential buildings, as mentioned above, the emission of combustion products near neighboring windows is undesirable. Here it is recommended to use one of two possible ways:
air intake for outer wall, and the release of combustion products into the built-in chimney (Fig. 3);
· air intake from the built-in ventilation duct and exhaust of combustion products into the built-in chimney (Fig. 4). 
Rice. 3 Smoke removal option C82 
Rice. 4 Smoke removal option C42
If preference is given to option C82, then you cannot ignore the height of the chimney, since in addition to pressure losses along the length and from local resistance, there is a natural draft that forms in the chimney due to the difference in air densities and temperatures at different heights from ground level. The performance of such a chimney must be carefully calculated so that the pressure drop in the differential pressure switch falls within the operating range, otherwise the boiler will not turn on. It is obvious that calculating the pressure loss in a chimney with an accuracy of 1 Pa (0.1 mm water column) is quite difficult and the probability that the calculation conditions will coincide with the actually constructed chimney is far from 100%. For this purpose, many manufacturers of mounted boilers offer as additional option special diaphragms, the installation of which, depending on the configuration of the chimney, will allow the pressure switch to obtain the required pressure drop and turn on the boiler.
With option C42, natural draft is excluded, since both the air flow and smoke emission are carried out from the same height - the roof. Here there are only pressure losses along the length of the chimney and from local resistances (fittings). In this case, the maximum permissible height of the air ducts is reduced due to increased resistance. This case is similar to the option with a built-in coaxial chimney (option C42), and for 9 storey building such chimney Can only be installed on floors 8-9 due to limited fan power. On lower floors it is necessary to increase the diameter of the chimney to reduce its resistance, or to increase the fan power.
With a separate chimney, an increase in fan power will lead to a decrease in the efficiency of the boiler, since the air exchange in the boiler, and, consequently, the consumption of combustion products, will increase, and along with them will be emitted into the atmosphere large quantity heat.
Summarizing our reasoning, we came to the conclusion that in order to meet the heat needs of residents of new multi-storey buildings, without harming others, it is possible to install both boilers with an open combustion chamber and “turbo” boilers. Moreover, for each type of boiler, only one solution for supplying air to the boiler and removing combustion products is acceptable. But, in both cases, you cannot do without an additional chimney in the kitchen. And if the kitchen also has a hood from gas stove provided, then for each such kitchen we get three channels in the wall: one ventilation and two chimneys. The word is up to the designers.
There is another option for apartment-by-apartment heating both in existing high-rise buildings and in new buildings - these are condensing boilers with a coaxial chimney in the outer wall of the kitchen. As is known, their environmental performance meets the most stringent international standards, and the flue gas temperature is less than 50°C. It is unlikely that the neighbors will feel anything, even with open windows. The possibility of installation in existing high-rise buildings, along with their efficiency and environmental friendliness, is another factor justifying the unusual high cost condensate technology.
Based on site materials
A separate smoke removal system provides for division into two separate channels - removal of flue gases and intake of combustion air. The system combines two types of elements - single-wall and double-wall insulated chimneys.
Application
A separate smoke removal system is used to supply combustion air and remove flue gases from domestic gas boilers with a closed combustion chamber, where the temperature of the flue gases does not exceed
200 Co. The installation is allowed to have a vacuum or overpressure up to 200 Pa. Most popular area
Applications: multi-apartment residential buildings with individual (apartment-by-apartment) heating.
All elements of the system in contact with flue gases are made of high-quality, corrosion-resistant aluminum AW-6060 and AB-46100 by extrusion or casting, and are seamless. The system elements are manufactured in thicknesses of 1.0, 1.5 and 2.0 mm, with a round cross-section. Diameter options: 60, 80 and 100 mm. WITH outside chimney elements are painted White color(9016 according to the RAL catalogue).
The insulated elements of the CONTI separate smoke exhaust system are covered with a layer of FONITECK insulation, 8 mm thick, based on melamine resin. The outer covering layer is made of aluminum and also painted white. Used in conditions low temperatures, at outdoor installation chimney and/or air duct. Insulated chimneys can be installed both inside and outside the building on an external wall.
Elements of a separate system can be used in conjunction with elements of a coaxial system. In-house and external production control by an independent testing institute guarantees constant compliance high standards product quality.
When designing, local and federal regulations should be followed. building codes and rules, as well as rules for installing gas-using equipment.
The chimney must ensure complete removal of flue gases from the boiler to the atmosphere, and the air duct must provide the required volume of air for gas combustion. The air intake must be made directly from outside the building.
Calculation of the smoke removal system
The design of a separate smoke exhaust system should be determined taking into account local conditions, boiler characteristics and chimney geometry. The calculation comes down to checking the pressure and temperature conditions. The pressure condition is that the vacuum at the entrance to the chimney, at any weather conditions and in all modes of operation of the boiler, it must be sufficient to overcome the resistance of the boiler, smoke exhaust and ensure the flow of air for combustion. Temperature condition limits minimum temperature inner surface chimney. It should not exceed 0OC. Failure to comply with this condition, during the period negative temperatures, will lead to freezing of condensate inside the chimney, narrowing of the working cross-section and possible emergency stop boiler Confirmation that the minimum temperature of the internal surface of the chimney exceeds the dew point temperature of water vapor in the combustion products is not required, because All elements of CONTI chimneys are made of moisture-resistant materials that provide maximum resistance to corrosion.
Separate smoke removal schemes
Horizontal outlet through the outer wall (chimney).
The chimney is discharged horizontally through the outer wall, without installing a chimney. The air duct is also routed horizontally through the outer wall. Standard kits can be used.
Vertical outlet through the roof.
The chimney is discharged vertically through the roof. When passing through the roof, a vertical terminal is installed. The air duct is routed horizontally through the outer wall.
Application: individual houses.
VeRtickalth conclusion byonRalreadyth wall.
The chimney is discharged vertically along the outer wall. In this case, to install the chimney, it is necessary to use insulated elements of a separate smoke removal system. The air duct is routed horizontally through the outer wall.
Application: individual houses.
POconnectionseto a collective chimney (with an individual air duct).
The chimney is connected to the collective chimney in the shaft. The air duct from each boiler is routed horizontally through the outer wall.
Connection to a collective chimney (with a collective air duct).
The chimney is connected to the collective chimney in the shaft. The air duct is connected to the collective ventilation duct.
Application: apartment buildings.
Multi-channel chimney (with individual air duct).
An individual chimney from each boiler is discharged vertically upward in a common shaft. The air duct from each boiler is routed horizontally through the outer wall.
Application: apartment buildings.
Multi-channel chimney (with collective air duct).
An individual chimney from each boiler is discharged vertically upward in a common shaft. The air duct is connected to the collective ventilation duct.
Application: apartment buildings.
Multi-channel chimney (with an air duct connected to the chimney shaft).
An individual chimney from each boiler is discharged vertically upward in a common shaft. The air duct is connected to the same shaft (air intake is carried out from free space in mine).
Application: apartment buildings.
Chimney (vertical section)
Chimney is a vertical channel for creating draft and removing flue gases from the boiler and chimney up into the atmosphere. The chimney must have a vertical direction and have no narrowings. It is prohibited to route the chimney through residential premises. The butt joints of chimneys should be located outside the ceiling structure at distances that ensure ease of installation, maintenance and repair. A condensate collector and a device for cleaning and inspection must be provided at the bottom of the chimney.
When installing chimneys in a shaft, the following minimum dimensions must be taken into account:
Minimum clearances to combustible materials
The minimum clearance to combustible materials for single-wall chimneys is 50 mm, for insulated ones - 0 mm.
Vertical chimney terminal
When installing the chimney vertically, above the roof, the following distances must be observed:
In all cases, the height of the chimney
above the adjacent part of the roof should be
not less than 0.5 m, and for houses with flat roof- not less than 2.0 m.
Smoke exhaust (horizontal section)
Chimney - a horizontal channel for removing flue gases from the boiler to the chimney or out through the wall of the building. Installing a chimney through the outer wall of a building, without using a vertical chimney, is possible only in individual houses.
When designing a chimney, try to minimize its length. It is advisable to use no more than 3 90° turns. If it is necessary to control flue gases and remove condensate in the chimney, appropriate elements are provided.
Horizontal flue terminal
When installing a horizontal terminal, the following distances must be observed:
Air duct
Air duct - a channel for supplying air to the boiler. The air duct is discharged into a shaft (vent duct) or through a wall. In the latter case, depending on climate zone, it is possible to use CONTI insulated elements to avoid the formation of condensation on the outer surface air duct pipe.
Similar to the chimney, try to minimize its length. It is advisable to use no more than 3 90° turns. The end of the duct must be equipped with a tip to protect it from debris and birds.
Condensate drainage
During operation of the smoke removal system, condensation may form on the inner wall chimney. It is very important to avoid condensation getting into the work area boiler, because this in turn can lead to the destruction of its active elements. To drain condensate, it is necessary to install a condensate collector. It is permitted not to install a condensate collector in cases where it has been confirmed that the temperature of the inner surface of the chimney wall at the mouth will be higher than the “dew point” temperature.
Further drainage of condensate is allowed into the sewer system provided it is diluted
in a ratio of 1:25, if the total power of the boilers does not exceed 260 kW. In other cases, it must be neutralized before being discharged into the sewer.
General provisions
Before installation, make sure that the packaging is intact and that the O-rings are present. System elements must be stored in their original packaging and protected from dirt and moisture. Use tools suitable for working with aluminum. After installation, near the connection between the chimney and chimney, be sure to install a sign indicating the type of chimney system.
Connecting elements
The elements of a separate smoke exhaust system are connected into a socket using O-rings. In this case, the parts must be installed in such a way that the socket is oriented in the direction of the flow of combustion products. O-rings are inserted into a special groove in the socket immediately before installation. When joining elements, it is allowed to use silicone spray for better glide.
Installation of the chimney and air duct should begin with the boiler adapter. Adapters come in two types: single block and double block. Single-block ones are mounted directly on the coaxial pipe of the boiler. When installing two-block adapters, an additional boiler hole for the air duct is used.
Next, depending on the installation geometry, install pipes and elbows sequentially required sizes. If necessary, install a flue gas control element and a condensate trap. These two elements are usually installed closer to the boiler smoke pipe.
Changing the length of straight elements (pipes)
Straight elements (pipes) of the CONTI separate smoke exhaust system can have a length of 6000, 2000, 1000, 500 and 250 mm. During installation, if necessary, the length of the pipe can be changed. To do this, using locksmith tool, cut off the unnecessary part strictly from the side of the smooth insert, i.e. the bell must remain untouched.
It is necessary to cut off the socket only at the end element of the chimney and air duct, when installing the tips.
Attention! It is prohibited to shorten the insulated elements of the separate CONTI system.
Final instructions
The CONTI separate smoke exhaust system is designed and tested to meet gas tightness requirements, corrosion resistance and ease of use. Can only be used for installation original elements CONTI, taking into account the manufacturer's instructions and recommendations. System elements must be protected from sparks, contamination and contact with lower quality materials.
Coaxial chimneys for wall-mounted gas boilers have recently wide application for modern heating equipment. This perfect solution for a private house in the absence of a chimney pipe, as well as for apartment buildings having a common riser for smoke removal.
Simplicity of design and aesthetic appearance do coaxial chimney indispensable for proper operation gas wall-mounted double-circuit or single-circuit boiler. Let us take a detailed look at its features, operating principles, requirements for installation and installation of this structure.
Coaxial chimney for gas boiler: what is it and where is it used
Coaxial chimney is used for heating with forced draft. The boiler itself must be turbocharged, i.e. have a built-in fan to exhaust combustion products. The very concept of “coaxial” means coaxial, i.e. chimney "pipe in pipe". Through the outer pipe there is an influx of air into the boiler, and through the inner pipe the exhaust gases are exhausted into the atmosphere.
The diameter of these chimneys is usually 60/100. Its inner tube is 60 mm, and its outer tube is 100 mm. For condensing boilers, chimney diameter: 80/125 mm. The material used is steel, painted with heat-resistant white enamel. Let's look standard equipment according to the photo diagram.
There is also such a thing as an insulated coaxial chimney. This is the same coaxial chimney, only outer pipe It is made not of metal, but of plastic. Or the second option: when the inner pipe is slightly longer than the outer one. This was done specifically in order to external pipe no condensation formed. This type of chimney costs a little more, but not much.
A coaxial chimney can be composed of several elements:
— coaxial pipes (extensions) of different lengths from 0.25 m to 2 meters;
— coaxial elbow (angle) at 90 or 45 degrees;
— coaxial tee;
- the tip of a pipe, sometimes an umbrella;
- clamps and gaskets.
Manufacturers of coaxial chimneys for gas boilers
When purchasing a wall-mounted gas boiler, you will be offered to immediately buy a coaxial pipe for it. In a normal, standard situation, a coaxial kit is sold for horizontal system smoke exhaust, which includes: a 90 degree elbow, a 750 mm extension with an outdoor tip, a crimp clamp, gaskets and decorative inserts.
If your case is slightly different, then all other parts and elements can be purchased separately. These elements are universal for almost any manufacturer of wall-mounted gas boilers.
The exception is the first element, this is either the first elbow or the first pipe from the boiler. The fact is that each boiler manufacturer has its own seating characteristics. This applies to branded (native) coaxial chimneys.
But there are times when pipes for a certain brand of boiler are not available or they are very expensive. For example, a branded coaxial kit for a German boiler costs about 70 euros. In such cases, you can consider purchasing its analogue.
Analogues of coaxial chimney manufacturers
These kits have universal seats, and the holes for attaching the starting elbow (outlet) coincide with most manufacturers of gas boilers presented on the Russian market.
Coaxial chimney "Royal Thermo"
Coaxial chimneys from " Royal Thermo» suitable for , Vaillant or Navien. When purchasing Royal pipes, look carefully at the packaging; on the end of it, each brand of boiler has its own article number: “Bx” - Baxi, “V” - Vaillant, “N” - Navien.
Another manufacturer on the market of coaxial pipes and elements for them is the company “ Grosseto».
Their chimneys are universal and suitable for boilers of the Ariston, Vaillant, Wolf, Baxi, Ferroli brands, as well as Korean and Korea Star.
The main advantage of universal analogues of coaxial chimneys is their low price. It differs from branded kits by two or even three times.
Installation and requirements for installation of a coaxial (coaxial) chimney
The coaxial chimney can be installed in three options:
— horizontally with access to the street;
— horizontally with outlet to the shaft (apartment heating);
- vertically with outlet to an existing chimney.
The most common way to output a coaxial chimney is horizontally with an outlet to the street.
Coaxial chimney into the wall
From the diagram above we see:
1 - coaxial pipe with a tip;
2 — coaxial elbow;
4 - coaxial pipe (extension);
For correct installation coaxial chimney there are a number of requirements
1. The total length of the chimney should be no more than 4 meters.
2. Only two turns are allowed, no more than two knees.
3. Minimum distance from the pipe to the section of the ceiling and walls made of them non-flammable material, should be 0.5 meters.
4. The horizontal section of the pipe should be made with a slight downward slope towards the street.
These must be done so that the resulting condensate does not flow into the boiler, but goes outside.
Separate chimney systems for gas boilers
Another popular method of removing combustion products from turbocharged gas wall-mounted boilers is a separate smoke removal system. What is it?
There are times when, for one reason or another, it is impossible to remove a coaxial chimney. For this purpose, a system was developed consisting of two separate pipes: one for the release of gases, the other for sucking air into the boiler. Let's look at the installation diagram.
Separate chimney for boiler
As a rule, the diameter of such pipes is 80 mm. Material: steel. In some cases, the air suction pipe is replaced with a flexible aluminum corrugation, which stretches up to 3 meters.
In order to install a separate chimney on a gas boiler, you need to buy a special adapter - a channel separator. It is installed on top of a mounted boiler and converts the “pipe-in-pipe” outlet into a separate one, onto which the pipes are then mounted.
Some manufacturers, for example, the same Navien, took care of consumers in advance and produce wall-mounted gas boilers since already installed system for separate pipes. This is a purely Korean version of boilers, designated under the article “K”. A boiler with such a system will be called “Navien Deluxe-24 K”, where 24 is its power in kW.
Installation of a boiler with a separate chimney system
Pipes can be laid out in 3 options:
- both pipes into one wall;
- both pipes in different walls;
- one pipe into the wall, the second into the existing chimney.
It’s up to you to decide which smoke removal method is right for your home. project organization. According to technical specifications, they make up individual project for every home.
It specifies the design of the gas boiler (floor-mounted, wall-mounted), its maximum power, as well as which pipes should be installed: separate ones or whether it is necessary to buy a coaxial chimney for a gas boiler.
The only thing they do not have the right to decide for you is the brand of the boiler. No one can force you to buy a model from a specific manufacturer. Here the choice is only yours. Let's watch the video.
The time of potbelly stoves and coal stokers is gradually coming to an end. And even the most modern industrial boiler houses are forced to make room for individual heating units and the ever-increasing demand for wall-mounted gas boilers. One of the reasons for such a surge in popularitygas wall boilers - the ability to install them in almost any room, combined with amazing ease of installation and adaptability to any needs and conditions.
To a large extent, the scope of application of boiler equipment is expanded by the chimney system proposed for them. In addition to the usual atmospheric chimney, which we have all known since childhood, coaxial chimneys have appeared, as well as various separate systems.
The smoke removal and combustion air supply system is an important part of heating and water heating equipment. From correct selection and the installation of a smoke removal system largely depends on the service life of your boiler equipment. It’s not worth even talking about such a factor as safety - carbon monoxide must be withdrawn in a timely manner in compliance with all fire safety measures. Errors in design can affect both the efficiency of the heating system and its performance.
Coaxial and separate smoke removal systems are used to remove flue gases from domestic gas boilers with a closed combustion chamber. They can be used in both individual and multi-apartment residential buildings.
Both of these systems consist of two parts - a chimney and an air duct. The chimney must ensure complete removal of flue gases from the boiler to the atmosphere, and the air duct must provide the required volume of air for gas combustion. Air intake can be carried out both directly outside the building and inside the premises, if it complies necessary requirements and provides sufficient fresh ventilation.
- COAXIAL CHIMNEY SYSTEMS FOR WALL BOILERS
The coaxial smoke removal system is used to remove flue gases from domestic gas boilers with a closed combustion chamber, where the temperature of the flue gases does not exceed 200 C. A vacuum or excess pressure of up to 200 Pa is allowed in the installation.
Coaxial chimneys usually manufactured in thicknesses of 1.0, 1.5 and 2.0 mm., round section. Inner pipe made of aluminum, external - made of steel or aluminum. Diameter options are most often 60/100 or 80/125. Moreover, size 60/100 is the most common, and 80/125 is used with wall-mounted condensing boilers, or in cases where the chimney exhaust system exceeds 4-5 meters.
Almost all elements of the coaxial system are universal - suitable for any thermal blocks, regardless of the brand. For example, extension sections toVaillant wall-mounted boilers, Buderus , Viessmann, Bosch boilers etc. - completely interchangeable.
The exception is an element that is attached directly to the boiler - this is an angular elbow or a vertical adapter for connecting to the boiler. The corner adapter is used for horizontal passage through the wall, and the vertical adapter for passage through the roof, or in cases where it is necessary to mount the horizontal passage slightly higher.
Therefore, if you purchase a wall (or roof) passage kit, then you also need to select it, like the boiler adapter, depending on the manufacturer of your boiler equipment.
The chimney elements are painted on the outsideI'm in white. Elements of the coaxial system can also be used in conjunction with elementsseparate chimney system 80/80 .
No additional insulation is required during installation - the minimum distance from combustible materials is 0 mm.
1.1 Calculation of the smoke removal system
The calculation of the coaxial smoke exhaust system must be made taking into account the installation location, boiler characteristics and chimney geometry.
When calculating, it is necessary to check the resistance of the chimney, and make sure that under all possible weather conditions and operating modes of the thermoblock, the vacuum at the entrance to the chimney is sufficient to overcome the resistance of the boiler and the chimney itself, and also ensures a sufficient flow of air for combustion.
It should be borne in mind that usually for a diameter of 60/100 the total length of the chimney should not exceed 4.5 meters, and each 90-degree bend reduces it by another 0.5 meters. If a larger length of the structure is required, then you should switch to a separate system, or to a coaxial chimney with a diameter of 80/125.
The temperature of the internal surface of the chimney must be at least 0 C. Failure to comply with this condition, during periods of negative temperatures, will lead to freezing of condensate inside the chimney, narrowing of the working cross-section and possible emergency shutdown of the boiler. It is also necessary to make sure that the temperature of the internal surface of the chimney in all modes exceeds the dew point temperature in the combustion products.
1.2 Coaxial smoke removal schemes
1.2.1 Horizontal outlet through an external wall
This is the most common scheme for constructing a chimney to a wall-mounted boiler. Due to its simplicity and low cost, it is used in the vast majority of cases.
|The coaxial chimney is discharged horizontally through the outer wall. During installation, it is necessary to ensure a slope of 2-3 degrees from the boiler in order to prevent condensate from entering the device.
For installation, standard basic wall penetration kits are usually used. Kits are selected by type (manufacturer) wall-mounted boiler. For examplebasic wall pass VAILLANT(art. 303807) or horizontal set BUDERUS (art. 7 747 380 027 3) are distinguished by an angular adapter for connecting to the boiler. The remaining parts are the same and interchangeable. And of course, you can use any extension elements for them, for exampleextension of coaxial pipe 60/100 1 meter, or coaxial elbow 60/100 angle 90 .
1.2.2 Vertical roof passage
In this case, the chimney is led out from the top of the boiler through the roof of the building. In this case, a vertical adapter is used (it is put directly on the boiler and each manufacturer has its own, see for exampleCoaxial vertical adapter Ø60/100 BOSCH, Buderus) . Next is mounted required amount extension elements, for exampleCoaxial pipe 60/100 2.0 m . Completes the design at the topVertical terminal Ø60/100 for passage through the roof - it provides hermetic connection with a roof.
This scheme is usually used in private houses and cottages.
1.2.3 Connection to the collective chimney
The coaxial chimney is discharged into the collective chimney shaft. Combustion air enters from the free space between the outer wall of the shaft and the common chimney liner.
In this case, a careful calculation of both the entire shaft and the chimney liner (sectional area, maximum length, distance between devices, etc.) is necessary in order to avoid the draft from one thermoblock to another overturning.
If such a calculation is difficult, then it is preferable to design a multi-channel collective chimney - when air intake occurs along common space, and the removal of combustion products through an individual channel.
Such chimney systems are usually used in apartment heating in apartment buildings.
1.3 Rules for installing coaxial chimneys
1.3.1 Vertical section
When designing and installing a vertical passage through the roof, you must be guided by the diagram below.
Chimney height for houses with flat roof should be more than 2.0 m, and if the roof is adjacent to the chimney - at least 0.5 above the adjacent roof.
To prevent condensation from entering the boiler, aCoaxial condensate collector Ø60/100 for straight-through pipes.
1.3.2 Horizontal section
When installing a horizontal passage through a wall, the following diagram must be observed:
When designing a chimney, it is important to reduce its length and number of turns as much as possible. It is advisable to use no more than 3 90° turns, since each of them reduces the permissible length of the chimney by an average of 0.5 meters.
To remove condensate, condensate drains are provided, and the chimney itself is mounted with a slope of 2-3 degrees from the boiler.
We will talk about the 80/80 split chimney system in part 2 of this article.