Pipe for a gas boiler room. Basic requirements for a chimney for a gas boiler: norms and rules. What masonry mixture is used during construction

For many, the concept of “chimney” is associated only with a pipe rising above the roof. In reality, this is only a small part complex design, through which combustion products are removed, and it does not matter at all what kind of fuel the heating unit uses. True, each of them has its own characteristics.

Today, for example, many people prefer gas equipment, but before you start selecting and buying a chimney for a gas boiler, you need to have at least some understanding of the principles of its operation.

Its design, the material from which it is made, and operational characteristics directly determine:
- the resulting economic effect, that is, the best efficiency of the boiler;
- operating life of the heating system;
- its safety in use.
Which chimney is best for a gas boiler?

It is necessary to clearly understand that an increased level of requirements is imposed on the design of gas boilers. In particular, this also applies to the flue gas exhaust system, although their temperature in this case is not so high - no more than 150˚ C.
- First of all, this is due precisely to the gas combustion product itself. On the one hand, this is ordinary water vapor mixed with carbon dioxide, which are considered neutral products, and on the other, the presence of sulfuric acid.
Although the content of sulfur impurities in gas fuel is not so high, even this is enough for their aggressive effect to manifest itself. As a result of the reaction of oxidized sulfur with the participation of water, oil of vitriol is formed. When sulfuric acid vapors are removed, they corrode the walls of smoke exhaust channels along their path, be it the simplest chimney made of stainless steel or brick. The operational life of the system in such conditions is reduced to several years.

Chimneys from of stainless steel made of special steel (AISI 316L grade). This material is not only heat-resistant, but also acid-resistant.
- Another nuance to pay attention to is the dew point. The likelihood of its formation in chimneys for a gas boiler in a private house when using them is real. If the temperature outside is quite low, when the vapor escapes, it condenses and creates a water lock. It blocks the path of exhaust gases, then the combustion process stops.
Attention
The brick channel in this sense is the most dangerous, since the roughness on the surface of the internal walls significantly increases the risk of a water lock.

From all of the above, we can conclude that the most appropriate design is a chimney for gas boilers made of stainless steel with special additives or from a ceramic or asbestos-cement pipe.

Pipes for the boiler can be placed in a shaft lined with brick, then it will look like brick.

Currently, the popularity of sandwich systems, which are double pipes with a layer of basalt wool, is growing. This version of the device is optimal for remote structures, since it no longer requires insulation from the outside.

Requirements

Such smoke exhaust systems mainly consist of:
- a flue, an adapter through which the outlet pipe and the pipe of the heating unit are connected;
- revision located along the lower part of the canal. Through it, the channel is cleaned of soot and the fallen condensate is removed, collected in a special pocket;
- fastenings - in accordance with SNiP they are installed with a minimum step of 150 cm ;
- individual structural segments and components necessary for installation of the system.
Here are some of the basic requirements for their installation:
- absolute tightness of the structure along its entire length;
- resistance to impact elevated temperatures;
- the system must be able to provide adequate draft, which will be sufficient to fully remove combustion products;
- The cross-sectional diameter of the exhaust pipe must match the diameter of the chimney for the gas boiler. Its value should be sufficient to guarantee good traction, maintain and repair the system if necessary;
- the maximum possible number of knees is three;
- turning points are equipped with inspection hatches through which the channel is cleaned and condensate is removed;
- the maximum length of a side branch is one meter;
- the pipe in places where the channel exits through the ceiling should not have joints;
- the height of the pipe must be greater than high point roofs. In this case, traction will be provided in any weather conditions, and even a side wind will not cause air leaks.
Device in a private house

Before starting installation, determine the location of the smoke exhaust duct. Accommodation can be:

Let's consider several options for placement inside the house.

Coaxial chimney for wall mounting

The best option for wall construction is considered to be coaxial. The double-circuit design is similar to a sandwich pipe, but there is no insulating layer in between the two pipes. Through this gap, the “exhaust” gas comes out, while at the same time it is taken in fresh air. This design increases the efficiency of heating equipment, since the air from outside, passing to the combustion chamber along the path of hot, already exhausted smoke, is heated.

Installation of these systems is quite simple.

The chimney pipe is led out through the wall, connecting it to the boiler through a passage pipe.

The outlet of the pipe is marked on the wall at the location of the boiler at a distance of more than two meters from the floor. Its diameter should not be much larger than the external size of the outlet pipe, since according to safety standards, the hole is lined with non-flammable insulation.

It is prohibited to install deflectors or other additional elements on the head of a coaxial structure.

Gas boilers without chimney

This is not an ordinary heating device that runs on gas, and the most valuable thing about it, perhaps, is the absence of a chimney in the traditional sense. Of course, whatever the heating system, it will be necessary to remove combustion products to the outside. In the innovative system, the outlet channel is assembled from plastic pipes. It is not at all necessary that it be installed strictly vertically. In addition, the number of turns is not limited. The heating boiler can operate not only on natural, but also artificially liquefied gas. As a result of any malfunction, the heating system automatically turns off.

Home installation

Preparatory stage

On the floors, as well as on the roof, the locations of the holes for the smoke exhaust duct are marked.

Cut out the required opening.

Connection
- The pipe that leaves the boiler is connected to the adapter. Then a tee with a fitting is installed, the pipe is cleaned through it, or with an inspection.
- In this area, the primary fixation of the pipe is performed. A support bracket is used for mounting to the wall.
- During the extension process, the pipes are fixed with brackets, placing them in increments of 300–400 cm. If necessary, elbows can be used. The pipes are secured using wall clamps installed at a distance of two meters from each other.
- In the place where the pipe passes through the ceiling, a passage pipe is installed. In the area of passage through the roof, an under-roof sheet with a variable slope is laid.
- The part of the pipe that is brought out is equipped with an apron, as well as a cone-shaped tip. To seal the interpipe space, sleeves with seals are used.
- All parts of the system that come into contact with flammable materials require insulation. For example, the passage pipe is surrounded by a foil mat made of basalt insulation and fixed with fire-resistant mastic.
Attention
An extremely important requirement is the tightness of the resulting structure. This can be checked using a regular soap solution. It is applied to the seams and the boiler is connected. The appearance of bubbles will indicate a leak in the system.
- To use a gas heating system, you must obtain a chimney certificate for a gas boiler. Acceptance and first start-up of the installed equipment is carried out by a representative of the gas industry.
For clarity, watch the steps of installing a chimney for a gas boiler in the video.

After choosing a place to install a gas boiler, you need to take care of installing a chimney to remove smoke and exhaust carbon monoxide. What material should it be made of? If several decades ago chimneys were made exclusively of brick, modern heating technology imposes completely different rules on the construction of chimneys. Not only that, it must comply with current building codes.

The chimney is designed to remove exhaust gases into the atmosphere. The work is based on the principle of natural traction. Depending on the conditions of use, chimneys have many design features. The performance of a gas boiler depends on what material the chimney is made of.

A prerequisite for using a gas boiler is the installation of a ventilation system

Brick chimney. They are rarely used, since modern gas boilers have a high efficiency. The temperature of the gas emanating from the boiler is low (about 100 degrees), and when moving up the chimney it cools and condenses on the walls, since there is steam in the outgoing gases. Therefore, it is very difficult to warm up a brick chimney to the dew point transition temperature. What to do if you already have a chimney from old stove in a good condition? In order not to dismantle an existing chimney, you can use:

lining, that is, insert stainless steel pipes inside, and fill the space between the chimney wall and the pipe with non-flammable heat insulator. Perlite, foam glass or expanded clay are suitable as a heat insulator. This procedure will insulate the chimney and significantly reduce the amount of condensate formed;

Sleeving

line the channel. Lining is performed if the existing chimney is of non-standard size or has a crooked channel. This method is more expensive than installing steel pipes. A special elastic polymer liner is placed in the chimney duct. Then steam is pumped from below by a generator, a reaction occurs and the filler expands, taking on the shape of a channel.

Sandwich made of stainless steel pipes. Widespread technology. Perhaps one of the best designs for arranging the chimney of a gas boiler. Manufacturers offer ready-made modules from which chimneys of various sizes and configurations are assembled. Structurally, it is a pipe that is contained in a corrosion-resistant steel pipe that is resistant to acids. The distance between the pipes is filled, as a rule, with heat-resistant basalt wool.

Coaxial chimney. Has an attractive appearance. The design resembles a recuperator device, when combustion products are discharged into the atmosphere through an internal pipe, and heated air is supplied to the boiler furnace through an external pipe. Such a chimney device does not require additional installation of a ventilation system, since the air from the room is not used for combustion by the boiler, and accordingly this affects the comfort inside the room. A coaxial chimney increases the efficiency of the boiler.

Coaxial pipe components

Ceramic chimney made from ready-made modules. Their main trump card is fire resistance and durability. They do not collapse even at a combustion temperature of 1200 degrees C. The manufacturer guarantees their reliable operation for 30 years, confirmed by European certificates. Their only drawback is their unpresentable appearance.

Main elements of chimneys:

pipes: chimney and extension;
tees;
knee;
condensate outlet;
draft regulators;
ending elements.

Advice. Condensation also settles on the inner surface of asbestos-cement and galvanized steel pipes, which is why they are not used when installing a chimney.

Installation of a chimney system

Chimneys of any design must necessarily comply with the requirements of regulatory documents SNiP and DBN.

the chimney must be perpendicular to the foundation. A small tolerance from the perpendicular to the side is possible up to 1 m per 300;

Chimney installation

inclined sections in cross-sectional area cannot be smaller than vertical sections;
The surface of the chimney channels from the inside must be smooth-walled. The composition of the materials from which they are made must ensure their tightness and fire resistance;
the channel cross-section is always calculated based on the boiler power;
At the bottom of the vertical chimney, a tee with a plug must be installed to drain condensation;
an inspection must be installed on the horizontal part of the pipe.

Height of chimneys according to standards

Correct placement of the chimney on the roof outside the wind pressure zone at the correct height relative to the roof ridge guarantees good draft and uninterrupted operation of the unit.

Standards for placing chimney pipes

Standards for placing the chimney in height:

The chimney must be located at least 50 cm above the roof ridge, provided that the chimney itself is located at a distance of one and a half meters from the ridge.
If the pipe is located at a distance of one and a half to three meters from the roof ridge, then the top of the pipe should be level with the roof ridge or higher.
Above flat roof the chimney must rise at least 1 m.
Additional strengthening of the gas outlet will be required if it is more than 1.8 m higher than the roof.

Advice. The ideal shape of a gas outlet for a heating gas boiler is an oval. In square pipes, carbon monoxide creates turbulence in the corners of the flue structure, as the gases tend upward in a spiral, which leads to a deterioration in draft.

Installation of a chimney according to the rules

Based on where the gas boiler will be located relative to the house, the chimney installation is carried out in two ways:

Indoors. Installing such a system is quite troublesome, and it is also necessary to strictly comply with fire safety requirements, because such a chimney has an increased risk of ignition or carbon monoxide leaking into the room. If all the rooms through which the chimney pipes pass are heated, then only the pipe located on the roof will need insulation. Please note that such a chimney is difficult to repair.

Coaxial pipe installation options

If you decide to install a chimney for a heating gas boiler yourself, then you first need to apply marks for drilling holes for the flue pipe in the ceiling and roof. Then double-check everything again, as they say: “measure seven times, cut once.” Cut out the opening. Now, let’s actually assemble the chimney:

connect the heating boiler pipe to the adapter;
Now you need to connect the tee and revision. After this, a sheet of steel is attached and the main holder is secured;
we extend the gas outlet pipe from the bottom up, if necessary, use elbows;
a special pipe is used in the place where the chimney crosses the floor of the house;
Next, you need to throw a galvanized sheet over the chimney with a hole made in it, which is larger than the diameter of the chimney, and secure this sheet at the top and bottom of the ceiling;
all places where gas outlet structures are joined must be additionally reinforced with clamps;
We put a cap on the very top of the chimney - it will protect the chimney from bad weather.

Internal and external placement of the chimney

Outside. Due to the uniformity of the constituent elements of the chimney, it is easy to install and therefore easy to repair. Such a chimney requires thermal insulation along its entire length. If you are installing a chimney on the outside of the house, then the procedure is as follows:

We mark the places for drilling openings and double-check. Then we thread the system passage through the drilled opening, one end of which is hermetically connected to the boiler pipe. The area that penetrates the wall is thermally insulated;
we attach the revision and tee, then connect the plug;
We install the flue elements from the bottom up. Don’t forget to attach the holders to the surface of the house;
We reinforce all joints with clamps;
Now you need to attach thermal insulation along the entire length of the chimney; this does not need to be done if you used a sandwich pipe.

Chimney installation methods

When installing a chimney, remember:

all structural elements must be assembled correctly, gaps are unacceptable, and deflection of elements is also unacceptable;
in places where the chimney crosses the structure of the house, it is necessary to install passage elements;
The boiler and chimney are connected by applying heat-resistant sealant to the joints.

Advice. Thermal insulation of the chimney is performed with mineral wool, which is wrapped on top with foil or a sheet of galvanized steel. But there are ready-made products made from mineral materials on sale; you only need to measure the diameter and length of the pipe.

Gas boilers without traditional chimneys

Gas heating boilers without traditional chimneys - this is a solution for apartments. These are units with a closed combustion chamber, they have a built-in special system to remove carbon monoxide. These boilers do not need a chimney with natural draft, because a special turbine in forced mode removes exhaust gases from the firebox. The gas exhaust system for such gas boilers can be used from polyvinyl chloride with any number of turns, and it is not necessary to maintain a vertical position. This type of chimney is designed as a coaxial type, it is led out through a hole in the wall of the apartment, and is aesthetically attractive.

Standards for installing a chimney relative to the building facade

When choosing a chimney for a gas heating boiler, be guided by the parameters of your device and the requirements for the installation of chimneys. This will guarantee your safety, as well as the uninterrupted operation of your gas equipment.

The arrangement of the exit path for carbon monoxide from the boiler must be carried out in accordance with established requirements and standards. There are dimensional and other restrictions for the chimney so that the outflow of smoke from the gas boiler is carried out safely for human health.

Each individual heating system has its own special requirements for organizing a combustion product removal system. For gas heating equipment, the main thing is to design the chimney in such a way as to ensure the best possible draft.

Gas boiler with chimney and air intake pipe

Ill-proper chimney system equipment can lead to the penetration of carbon monoxide into a living space - this, in turn, poses a serious danger to human health and life.

Requirements for the material for the manufacture of chimneys

The following requirements apply to the material used for the manufacture of pipes intended for the removal of flue gases:

resistance to high temperatures;
high anti-corrosion qualities;
chemical inertness.

Exhaust pipe

Inside, on the walls of the smoke exhaust pipes, due to constant temperature changes, condensate constantly forms, which contains a high content of sulfuric acid. Therefore, it is extremely important that the material used to make the chimney does not come into contact with chemical reaction with acids and also has excellent corrosion resistance. When purchasing, you should also separately specify that the thickness of the inner layer is at least 0.05 cm.

Advice. To reduce the amount of condensate released inside the pipe, the chimney should be insulated.

Metal, ceramic or coaxial chimney?

In a private house, chimney pipes for gas-fired boilers can be metal, ceramic or coaxial. The preferred type of flue pipe material that is suitable for use with a particular boiler is usually indicated by the manufacturer in the technical documentation.

Chimney device

The most common option is a metal chimney that can withstand an operating temperature of 800 degrees. Typically, the pipes of such chimney structures are made of stainless steel; ferrous metal coated with zinc can also be used as a manufacturing material.

In general, the standard design consists of several components: the inner layer of the chimney is made of stainless steel, on top of which there is a layer of heat-resistant basalt wool and a thin iron casing. Among the advantages of metal chimneys are high resistance to mechanical damage, as well as increased reliability and a universal, presentable appearance.

Ceramic chimney pipe

Ceramics, which can withstand up to 1200 degrees, are in slightly less demand among consumers. The structure also consists of three layers: a ceramic component, a layer of insulation and a hard shell of expanded clay concrete. Chimneys made from this material are distinguished by their simplicity and reliability, ease of installation, as well as high fire safety.

The coaxial chimney is valued for its presentable appearance and fairly high performance characteristics. In general, this type of construction has a somewhat specific shape, due to which it has an important advantage - condensation does not form on its internal walls. This property is very important for gas equipment, so when choosing a suitable material you should consider purchasing a coaxial chimney.

Diagram: coaxial chimney device

Attention! Brick pipes Suitable for solid fuel, not gas equipment. Therefore, for gas boilers, an old brick chimney must be converted by inserting a liner made of metal, followed by insulation.

Basic standards

Section size and shape

When calculating the cross-sectional area of a chimney pipe, the dimensions of the pipe installed on a particular gas boiler are taken into account - the chimney ultimately must be no smaller in size. Two boilers can be connected to the chimney pipe, but only on the condition that their inputs will be located at different levels and at a distance of 0.5 m relative to each other.

In this case, the cross-sectional area of the pipe is calculated as the total power of both heaters, multiplied by 5.5. For example, provided that the power of one according to the passport is 1 kW, and the other is 1.4, the cross-sectional area of the common pipe will be (1 + 1.4) x 5.5 = 13.2 cm square.

Installation of a chimney system for a gas boiler

The cross-sectional shape can be in the form of a rectangle or a circle. The smoke flow moves in a spiral inside the chimney and, encountering corners, loses its speed, so round form more preferable, allows for high-quality traction.

Pipe location

The chimney must be installed in a vertical position. The permissible deviation is no more than 30 degrees or up to 1 meter in any direction. At the point of connection to the chimney pipe of the gas unit, a vertical section must be installed, and the height of the section must be at least 0.5 m.

Correctly installed chimney for a gas boiler

Ideally, there should be no bends and all kinds of roundings on the chimney pipe at all, but up to 3 such outlets are allowed. It is allowed to slope horizontal pipes exclusively in the direction where the boiler is located, with a slope angle of up to 0.01 degrees.

Number of probes

It is allowed not to install headers if they impede the exit of flue gases. Under each of the probes, which are located on the tip, you cannot place more than 1 pipe, that is, all individual pipes must have their own “fungi”. The headband must have a cone shape.

Rules for the installation of chimney pipes intended for gas units

During the installation process, you must adhere to a number of established rules:

installation is always carried out in the direction from bottom to top;
the structure is attached strictly vertically;
pipes in height should not reach more than 5 m;
the slightest deflections of pipes are excluded;
all joints, transitions and curves must be carefully sealed using heat-resistant sealant;
along the path of smoke movement there should not be more than 3 horizontal transitions more than 1 meter long;
the head should be located above the wind pressure zone.

Chimney outlet options

Another important requirement for a chimney structure is the mandatory fastening of the pipe to the adjacent wall. Ideally even sections of the pipe are fastened in sections of 150 cm, while its individual parts are fixed to each other without exception. To enhance the overall reliability of the structure, all connections of the elements are fastened together with metal clamps.

SNiP requirements

Regardless of the type of construction, all chimneys for gas boilers must be manufactured and installed in accordance with SNiP 2.04.05-91 and DBN V.2.5-20-2001. Strict adherence to all requirements guarantees safe operation heating system. If the standards set out in these documents are violated, problems will arise that will need to be resolved directly with the gas industry.

Proper chimney installation

The main points of the regulatory documents:

good traction must be organized;
the design of the condensate collector must be carefully thought out so that excess moisture does not accumulate on the walls of the chimneys;
It is not allowed to install fungi, deflectors, etc. on the chimney head, since they slow down the process of removing combustion products;
When carrying out installation work, special attention must be paid to the tight fit of all individual structural parts at the connection points;
A mandatory requirement is to maintain complete tightness at the joints and joints.

Conclusion

The installation of chimney pipes is a responsible process. If installation errors are made, the system may fail, causing serious harm to health and even a threat to human life. Also, if the requirements and standards are not met, more frequent cleaning of the pipe will be required, since large quantities of ash will settle on its walls.

Connected gas boiler

Therefore, during the installation process, especially when it comes to a complex chimney system, it is recommended to involve qualified specialists who will draw up a separate project, as well as carry out all the necessary calculations and ensure the uninterrupted functioning of gas equipment.

Connecting a gas boiler: video

Chimney for a gas boiler: photo

Any heat source that burns fuel emits a byproduct - toxic exhaust gases. Accordingly, installing a heat generator in a private house or apartment involves installing a chimney pipe that discharges harmful gases to the street. In terms of labor costs and price, these works make up a significant portion of the entire installation. We decided to highlight this stage and specifically explain how to properly make an inexpensive chimney for a gas boiler. Let's not ignore other types heating units.

Gas duct options for a country house

To remove combustion products with a relatively low temperature (up to 120 ° C) emitted by gas boilers, the following types of chimneys are suitable:

three-layer modular sandwich made of stainless steel with non-flammable insulation - basalt wool;
a channel made of iron or asbestos-cement pipes, protected by thermal insulation;
ceramic insulated systems such as Schiedel;
a brick block with a stainless pipe insert, covered on the outside with heat-insulating material;
the same, with an internal polymer sleeve of the FuranFlex type.

Three-layer sandwich device for smoke removal

Note. Gas boilers with a closed combustion chamber (otherwise called forced-air or turbocharged) should be equipped with coaxial chimneys. In fact it is double walled metal pipe, capable of simultaneously sucking in combustion air from the street and throwing smoke out.

Let us explain why it is impossible to build a traditional brick chimney or install an ordinary steel pipe connected to a gas boiler. The exhaust gases contain water vapor, which is a product of combustion of hydrocarbons. From contact with cold walls, moisture falls out as condensation, then events develop as follows:

Thanks to numerous pores, water penetrates into the building material. In metal chimneys, condensate flows down the walls.
Since gas and others (using diesel fuel and liquefied propane) operate periodically, frost has time to capture moisture, turning it into ice.
Ice granules, increasing in size, peel the brick from the inside and outside, gradually destroying the chimney.
For the same reason, the walls of an uninsulated steel flue closer to the head are covered with ice. The passage diameter of the channel decreases.

Ordinary iron pipe insulated with non-flammable kaolin wool

For reference. On the outside, unsightly, dirty streaks form at the joints of single-walled metal chimneys.

Since we initially undertook to install an inexpensive version of the chimney in a private house, suitable for DIY installation, we recommend using a stainless steel sandwich pipe. Installation of other types of pipes is associated with the following difficulties:

Asbestos and thick-walled steel pipes are heavy, which complicates the work. In addition, the outer part will have to be sheathed with insulation and sheet metal. The cost and duration of construction will definitely exceed the assembly of the sandwich.
Ceramic chimneys for gas boilers are the best choice if the developer has the funds. Systems like Schiedel UNI are reliable and durable, but too expensive and out of reach for the average homeowner.
Stainless steel and polymer inserts are used for reconstruction - lining of existing brick channels, previously built according to old projects. It is unprofitable and pointless to deliberately fence such a structure.

Flue option with ceramic insert

Advice. It is better to purchase sandwich chimneys made entirely of stainless steel - they will last longer and maintain a presentable appearance. If the project budget is very limited, take a modular system lined with galvanized metal - the structure will last at least 20 years.

A turbocharged gas boiler can also be connected to a conventional vertical chimney, organizing the supply of outside air through a separate pipe. The technical solution should be implemented when a gas duct leading to the roof has already been installed in a private house. In other cases, a coaxial pipe is installed (shown in the photo) - this is the most economical and correct option.

The last one deserves attention, the most cheap way construction of a chimney: make a sandwich for a gas boiler with your own hands. Taken stainless pipe, wrapped in basalt wool of the required thickness and covered with galvanized roofing. Practical implementation this decision shown in the video:

Chimney of a solid fuel boiler

The operating mode of wood and coal heating units involves the release of hotter gases. The temperature of the combustion products reaches 200 °C or more, the smoke channel warms up completely and the condensate practically does not freeze. But it is replaced by another hidden enemy - soot settling on the inner walls. Periodically it ignites, causing the pipe to heat up to 400-600 degrees.

The following types of chimneys are suitable for solid fuel boilers:

three-layer stainless steel (sandwich);
single-wall pipe made of stainless or thick-walled (3 mm) black steel;
ceramics.

A brick flue of rectangular cross-section 270 x 140 mm is lined with an oval stainless pipe

Asbestos pipes are contraindicated for installation on TT boilers, stoves and fireplaces - they crack from high temperatures. A simple brick channel will work, but due to roughness it will become clogged with soot, so it is better to line it with a stainless insert. The FuranFlex polymer sleeve will not work - the maximum operating temperature is only 250 °C.

Design and procurement of materials

To select the correct parts for a modular chimney and calculate the amount of materials, perform a number of preparatory steps:

Study the requirements for gas boiler chimneys.
Determine the installation method, channel diameter and thermal insulation thickness.
Draw a diagram and make a list of materials.

For reference. Typically, installing a heat source in country house begins with the installation of gas ducts and exhaust pipes ventilation. Placement of the heat generator in the boiler room and connection to the heating is done secondarily.

It is better to build internal channels during the construction of a house

The buzz words “calculation” and “project” in the list above may confuse some homeowners. In reality, these steps do not represent big problem. So that you don’t have to look for regulations on the installation of chimneys, we will provide them here.

Regulatory requirements for chimney pipes

The instructions given in the building codes and regulations (SNiP) must be taken into account for a simple reason: the fuel supplier company will not accept the gas boiler into operation and will not connect it to the main line if the gas duct is installed incorrectly. The requirements sound like this:

In the lower blind part of the vertical section there is a hatch for cleaning (inspection) and a condensate collector with a discharge fitting. The section of pipe near the boiler can be made single-walled, but the sandwich must go outside or into the adjacent attic.

Important. The minimum height of the chimney structure should be 6 m, counting from gas burner or the grate of a solid fuel boiler.

Determine the diameter and method of laying

The solution to the first question is found in the requirements for chimney ducts: look at the connecting dimensions in the heat generator’s data sheet and select a sandwich chimney with an identical or larger diameter than the outlet pipe.

Indentations when installing a coaxial chimney

Question two: how to choose the thickness of the thermal insulation of the sandwich, because the manufacturer offers at least 2 options - 5 and 10 cm. To protect the chimney connected to the gas boiler from copious discharge condensation and freezing, an insulation thickness of 50 mm is sufficient. 10 cm insulation should be used in northern regions with critically low winter temperatures.

It remains to choose a laying method from two possible ones:

bringing the horizontal section out through the wall and connecting it to a vertical attached chimney;
pass a vertical pipe through the ceilings, attic and roof, that is, lay a smoke exhaust duct inside the house.

Installation options for conventional and coaxial smoke ducts

Note. Both options are suitable for installing coaxial flue ducts, but in most cases the first one is implemented with a passage through the outer wall.

Laying the pipe along the shortest path to the street and lifting the pipe along the wall is the simplest and cheapest way. You will have to cross only one structure, and in the second option - at least two. Plus sealing of the junction of the roofing covering and the chimney.

On the second floor, such a structure will have to be sewn up

Try in every possible way to avoid indoor installation, since in a house with two floors or mansard roof a healthy pipe will inevitably pass through the premises, taking up useful space. Draw a sectional diagram of the building and a passing chimney if it cannot be mounted outside.

We make a list of parts according to the diagram

To install an attached chimney connected to a gas or solid fuel boiler, you will need the following elements of a modular sandwich:

tee with 89° branch pipe for joining the horizontal section with the vertical one;
tee with inspection hatch;
section with condensate collector;
a section of a single-wall pipe and a coupling for connecting a heat generator;
transition ordinary pipe- sandwich;
straight sections - the number and length are selected according to the length of the gas duct;
2 30° elbows are required to bypass the roof overhang;
an upper cap in the form of a nozzle that protects the insulation of the last section from precipitation.

Detailed diagram for outdoor installation

Important point. The installation of fungi and decorative canopies on the chimney of a gas boiler is prohibited. During periods of extreme frost, the top will freeze and the flow area will decrease, which is dangerous for the lives of residents.

The fastening parts will require wall clamps with brackets and a support platform that can support the weight of the mounted structure. If you plan to install a gas duct inside the building, you will additionally need ready-made units for passage through the ceilings, a roof sealing lining (otherwise known as hood, master flush) and 90° elbows for installation chimney in the boiler room.

Installing a sandwich chimney

The first stage of installing an attached structure is punching a hole in the outer wall and preparing for laying a horizontal section. In a house built from combustible materials, the opening is made taking into account the fire safety clearance (38 cm from the edge of the wooden wall to the inner pipe of the sandwich) and the installation of the flange of the passage unit, as shown in the photo.

Note. In fireproof structures made of bricks and foam blocks, a fireproof cutting device is not required. A metal sleeve is placed into the opening and a section of the flue is inserted, sealing the gap with non-combustible material.

Work on installing the modular sandwich and connecting to the gas boiler is carried out in the following sequence:

Reminder. IN wooden house seal the gap between the ends of the wall and the intersecting pipe with basalt fiber, and then install metal flanges on both sides.

Straight sections are simply inserted into each other and secured with clamps; there is no need to coat the joints with sealants. If trimming is necessary, then the lower end of the section is shortened, where the insulation is located flush with the metal linings. A protective cone is placed on the upper edge of the chimney.

Detailing for internal installation

Laying a smoke exhaust duct inside a building is done in the same way, only you will have to go through the structure twice, or even three times. The same rules for constructing cuttings when crossing flammable floors and walls are observed everywhere. At the end, you need to carefully seal the roof where the pipe passes, as is done in the video:

Conclusion

A chimney is far from a simple structure, hence the large number of regulatory requirements. In this regard, it is easier to install a coaxial pipe connected to a gas boiler with a closed combustion chamber - it is not designed to create natural draft. One difference: a horizontal double-walled flue is installed with a slope away from the heat generator so that the condensate flows out.

Initially, the correct installation of the smoke duct will be checked by specialists who will come to connect the boiler to the gas main. If you make serious mistakes during the installation process, you will be forced to redo the pipe. Minor flaws will appear during operation, and you will also have to eliminate them yourself.

Gas ducts in an apartment building or private building are considered mandatory element ventilation. The exhaust structure of the chimney can be external or internal. The chimney device has different variants execution. At the same time, it is important to know what sizes, types, and standards for drainage channels there are.

The hood is used for forced ventilation. Its design includes an air intake that tapers to a bell. The latter is mounted to the pipeline. This mechanism can be found above the plates. For the heating system, a similar system is implemented, but the execution is different. For a gas boiler, the chimney plays the role of an exhaust hood.

The need to install a chimney:

Removing gas combustion products and preventing them from entering the house;
Draft for oxygen to enter the system;
Effective use of the system.

But these functions will be provided when correct installation systems. All installation and commissioning work must be agreed upon with the gas service. But when using a gas cylinder, you do not need permission from the service. But during inspections, violations may be found and the system will be prohibited from operating.

Types of chimneys for gas boilers

The chimney for the boiler creates optimal and safe working conditions by removing combustion products. But before installation, you need to select a scheme and installation option. Chimneys are divided depending on the material of manufacture.

Types of chimneys:

Made of brick. To install it, a foundation is required, so installation of the system is carried out at the design stage of the house. The inner coating of the pipes must be sufficiently smooth. And the brick itself is resistant to aggressive vapors.
Made from stainless steel. The material is resistant to chemical and mechanical influences. The system appears to have a sandwich design. A product with a smaller diameter is mounted into an external stainless steel pipe.
Coaxial design. This is a split chimney where the pipe fits into the pipe. Oxygen for combustion enters through one, and combustion products exit through the other. Thanks to this, the efficiency of combustion and fuel use increases. Moreover, this design is considered environmentally friendly.
Made of ceramics. These look like heat-insulating ceramic blocks mounted in concrete base. A ceramic chimney has many advantages, but the main thing is to connect the modules correctly.

We suggest studying the advantages of installing coaxial type chimneys:

Certain pros and cons apply to each specific case. The main thing is that the design complies with building codes and regulations. SNiP prescribes the correct installation of any type of chimney.

Standards and requirements for a gas pipe in a private house

All work with the chimney, from design to installation, is strictly regulated by building codes. All information is specified in SNiP 2.04.05-91 “Heating, ventilation and air conditioning”. If these rules are neglected, the pipeline will prove dangerous during use.

Main regulatory requirements:

Good draft will ensure rapid removal of combustion products;
Thermal resistance;
All connections must be treated with sealant;
The section of pipe through the roof must be solid;
To collect and remove liquid, a condensate collector is provided in the system;
If there are turns, you will have to equip inspection hatches, which will help monitor the condition of the chimney;
The optimal length of branches should not be more than 1 m;
The number of turns is no more than 3;
For good draft, the chimney pipe must be higher than the roof structure;
The distance between flammable materials is 25 cm, non-flammable - 5 cm.

The gas boiler is most often located in a separate room -. All connections are assumed to be tight. All other installation rules are described in the above standards.

The tightness of the connections will ensure the insulation of the structure, and combustion products will not leave the system.

The chimney elements include a flue, pipes, inspection and connecting elements. The flue is a channel that is located at the junction of the boiler and the pipe. The revision is used to clean the structure. It is located at the bottom of the chimney.

Find out about making the right choice pipes for the chimney and features of the manufacture of the smoke exhaust system:

The sequence of installing a chimney for a gas boiler in a private house

There are internal and external installation systems. It all depends on the stage of design planning. When building a house, the internal system is performed. In prefabricated buildings, the external structure is performed.

The external system is characterized by the need for complete thermal insulation of the chimney. To do a good job, you will need to follow all the rules and regulations. Elements of the same type are selected for the design. Their connection is quite simple. At the same time, the system is freely accessible for maintenance.

When installed internally, the system must be installed in a strictly vertical order, without deviations in the diameter of the pipes.

The internal structure requires thermal insulation only in the area that is located on the street. The system is unsafe: smoke can enter the room, there is a high fire hazard. The number of structural elements is quite large, so installation has certain difficulties. Operating a chimney also has its difficulties.

Consistently internal installation:

Marking the structure and connecting elements;
Equipment for the chimney opening;
Connection of the boiler to the flue through a special pipe;
Installation of revision and tee;
Pipe installation;
Attaching clamps at joints;
Installation of brackets;
Thermal insulation.

The internal system is installed during the construction of the house and the construction of the foundation. This is how you can make a safe structure. Due to this, the amount of liquid in the pipes is minimal. Otherwise, you will need to equip a condensate collector.

How to properly install a chimney on a gas boiler

The chimney installation must comply with building regulations. Otherwise, problems will arise with the operation of the structure. All installation features are taken into account in a number of rules and recommendations.

Installation Tips:

The maximum pipe slope is 30 degrees;
To remove condensate, it is necessary to install a condensate collector at the bends of the system;
You should think about the marking of the drip and revision in advance;
It is mandatory to install dampers to stabilize traction;
On the street it is necessary to insulate the pipe;
When joining elements, there should be no cracks or gaps;
The joints will need to be well sealed;
The pipe installation must be in a strictly vertical position;
For insulation, you can use mineral wool, and install a brick layer on top of it.

In addition, special attention should be paid to the material used to make the chimney. It is best to choose fire-resistant elements. The pipe itself must be smooth; bends and irregularities are not welcome. Before starting work, you will need to thoroughly inspect the integrity of the structure. Pipes must be smooth and even.

The main cause of chimney failures is the presence of condensation. At the design stage, it is important to consider the drainage of liquid from the pipe.

The internal structure of the pipe must be freely accessible for cleaning and repair work. If you deviate from the standards, the gas service may prohibit the use of the boiler. It is important to approach the installation process correctly and responsibly.

Stages of installing a pipe for a gas boiler

First, equipment is purchased and all tools and materials are prepared. Also, a project, diagram and all calculations must be prepared in advance. After this, you can build a veterinary channel.

How to build a chimney:

First, preliminary assembly of the structure is carried out to ensure the integrity and completeness of the materials;
The chimney is then connected to the gas boiler;
All structural elements must be fixed with connecting parts;
The system is then checked for leaks.

The outer pipe is discharged from the boiler room through the wall. Sometimes they can use ready-made ventilation or a window. You will have to make a hole in the wall of the required diameter for the pipe and thermal insulation.

There is no need to rush the hole. First you need to make sure the calculations are accurate.

One section of pipes is inserted into the resulting hole, secured and insulated. On the street, sections are gradually added and a plumb line test is performed. Using brackets, the chimney is attached to the wall. The end of the chimney is equipped with a roof.

Fighting liquid: condensate collector for the chimney

A condensate trap is a special compartment in a pipe where liquid accumulates. But you can reduce the amount of condensate in other ways. Therefore, only dried fuel should be used.

Smoke must move freely through the pipes, so the walls of the chimney must be smooth and even, with minimum quantity bends.

Proper operation of the pipe requires regular cleaning of soot and contaminants. Additional devices are also welcome. You will need to install a protective cap, a collector, a limiter and a diverter.

If the temperature of the gases exceeds 100 degrees, then the condensate will not settle on the walls of the chimney, but will simply evaporate. Compliance with the standards guarantees the effective use of the chimney. All dimensions and locations of pipes should be adhered to.

Types of chimneys for a gas boiler in a private house (video)

A chimney is needed for any AOGV boiler. Doesn't matter, it's done internal installation or external, but basic standards and GOST should be observed in everything. The ventilation ducts of a wall-mounted gas boiler must be well insulated and insulated.