Requirements for chimneys for gas boilers chimney device snip main

One of the most important parts of a gas-fired heating system is a properly constructed chimney. It is no coincidence that gas service workers have strict but reasonable requirements for the chimneys of gas boilers. Not only the efficient operation of a gas boiler, but also the safety of the residents of the house depends on a properly installed system. When gas appliances operate, there is no visible smoke, as there is from appliances running on solid fuel, but this does not mean that there is no possibility of carbon monoxide accumulation. It is dangerous because it can negatively affect a person’s health without him noticing.

Requirements for chimneys of gas boilers

Owners of private houses must know how the smoke exhaust system is designed in the house where they live in order to operate it correctly. And those who are just planning to install a gas heating device should be aware in advance of what types of chimneys there are and how they are installed in order to decide which one to choose.

Recommendations from the pros!

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Principle of operation

The operating principle of any chimney is based on a simple law of physics - warm air and vapors are always lighter and tend to rise, while cold air is heavier and, accordingly, settles below.

Due to the difference in temperature between the street (outside the pipe) and hot gases (inside the system), draft appears. Thanks to it, combustion products do not disperse throughout the room, but escape into the atmosphere.

Boiler room

Gas equipment is connected directly to the boiler room. Relative to the house, furnaces can be located:

inside - built-in;
nearby on a separate foundation - attached;
at some distance - separate.

Depending on the location, the premises are subject to certain requirements aimed at ensuring safety during operation.

Built-in

According to SNiP, gas equipment with a power of up to 350 kW is allowed to be installed inside the house. Boilers up to 60 kW can be placed in any room. As a rule, this is a kitchen or domestic premises. More powerful heat generators are located on the first or ground floors, in the basement.

The ceiling in the room should not be lower than 2.5 meters. Ventilation is calculated to replace air three times within an hour, that is, the cross-section of the ventilation ducts should ensure the rate of natural circulation of an amount of air equal to triple the volume of the room.

The size of the window opening minus the sashes must meet the explosion safety requirements. In accordance with it, the area of easily removable structures, in this case glazing, is calculated from the condition of 0.03 m² per 1 cubic meter of room.

When the power of the heating unit is over 150 kW, the room is equipped with a separate exit. Regardless of the characteristics of the boiler, a passage along the front of at least 1 m is left.

Attached premises

An attached boiler room with heating units with a power of up to 350 kW is placed along the blank wall of the house. Set aside at least 1 meter from the nearest door or window opening. The furnace structure should not be rigidly adjacent to the foundation, walls and roof of a residential building.

The material for the walls of the boiler room is selected taking into account the minimum fire resistance limit - 0.75 hours. The structures should not burn or support combustion.

The height of the boiler room inside is at least 2.5 m. The equipment is placed so that it is convenient to service it. The size of the free area in front of the boiler is 1x1 meter.

The attached premises are equipped with a separate exit to the outside. The door should open to the street.

Natural light is a must. The glazing area is at least 0.03 m³ per 1 m³. The hood must support three hourly air exchanges.

The door leading to a residential building is made of fireproof materials. It must comply with the third type of fire safety.

Installing a gas boiler in the kitchen

When installing a gas stove, water heater and boiler with a power of up to 60 kW in the kitchen, the following requirements are imposed on the room:

When installing gas-using equipment, they are guided by the manufacturer’s passport. The walls must be made of fireproof materials, and the distance to the unit must be at least 20 mm.

It is allowed to install boilers near walls made of combustible materials, provided that the surface is protected with a 3 mm thick asbestos sheet and roofing steel or plaster. In this case, at least 30 mm should be removed from the enclosing structures. The insulation is extended beyond the dimensions of the equipment in height and width by 10 and 70 cm.

The floors under the boiler also protect against fire. Sheets of asbestos and metal are laid on them so that their boundaries exceed the dimensions of the body and protrude by 10 cm on all sides.

SNIP for chimneys and stoves - the most important thing

Reading regulatory documentation, although useful, is very boring, and searching for the necessary information in it is also difficult. So, for example, in SP 7.13130.2013 “Heating, ventilation and air conditioning. Fire Safety Requirements" (this is an updated version of SNiP for chimneys) barely 10% of the text is related to chimneys and, in general, to heating in low-rise buildings. The home craftsman need not read everything else. The problem is that these percentages are distributed fairly evenly throughout the text.

“Usadba” brings to your attention excerpts from SNiP (SP) on chimneys, which specifically relate to individual heating of low-rise buildings. We hope you find this information useful.

Number of stoves in the house↑

One stove can be used to heat no more than three rooms located on the same floor.

Stoves in two-story buildings↑

In two-story buildings, two-tier stoves can be installed, provided that:

the stoves are equipped with two separate fireboxes (one per floor);
Each firebox has a separate chimney.

In two-story apartments, only stoves with one firebox on the lower floor can be used.

Floors ↑

If a building uses a two-tier oven, the use of a wood-beam floor that separates the tiers is not permitted.

If you use stove heating ↑

use forced exhaust ventilation without using forced supply ventilation (necessary to maintain normal draft and prevent flue gases from entering the room);
lead the chimney into the ventilation duct;
use the chimney as a ventilation duct.

One stove - one chimney ↑

A simple rule: each stove must have a separate smoke channel. If two stoves are located in the same apartment on the same floor, they can be connected to the same chimney. In this case, cuts should be installed in the lower part of the pipes dividing the channel. The cutting height is at least 1 meter.

Size of concrete and brick chimneys ↑

with power up to 3.5 kW – at least 140*140 mm;
with a power from 3.5 to 5.2 kW - at least 140*200 mm;
with a power from 5.2 to 7 kW - at least 140*270 mm.

Size of steel and ceramic chimneys with round cross-section ↑

The internal cross-sectional area of steel and ceramic chimneys must be no less than the area of the corresponding chimneys with a rectangular cross-section. Thus, the internal diameter of the chimney should be:

with a furnace power of up to 3.5 kW - at least 16 cm (area approximately 200 cm2);
with a furnace power from 3.5 to 5.2 kW - at least 19 cm (area approximately 280 cm2);
with a furnace power of 5.2 to 7 kW - at least 22 cm (area approximately 378 cm2).

Valves in chimneys of solid fuel stoves ↑

In the smoke ducts of solid fuel stoves, valves with a hole of at least 15 x 15 mm should be used.

Chimney height ↑

The height of the chimney largely determines the draft force. Within reason, the rule applies: the higher the height, the better the traction. According to SNiP, the height of the chimney from the stove grate to the mouth (exit) of the chimney must be at least 5 m.

The height of the chimney above the roof ↑

Any objects located near the mouth of the chimney impair draft. That is why SNiP provides a minimum height of the chimney above the roof. It amounts to:

on a flat roof - at least 500 mm;
on a pitched roof, if the pipe is located less than 1.5 m from the parapet or ridge - at least 500 mm from the top point of the parapet or ridge;
on a pitched roof, if the pipe is located at a distance of 1.5 to 3 meters - not lower than the level of the upper edge of the ridge or parapet;
on a pitched roof, if the chimney is located at a distance of more than 3 meters from the ridge or parapet - not lower than the conventional line, which is drawn down from the ridge at an angle of 10º.

If a taller building is attached to the building on the roof of which the chimney is installed, the mouth of the chimney should be located above the highest point of this building.

Construction of chimneys made of brick or heat-resistant concrete ↑

Brick chimneys must be vertical without ledges. The thickness of the chimney walls made of brick is at least 120 mm, and that of heat-resistant concrete is at least 60 mm. At the base of chimneys there should be pockets up to 250 mm deep with holes for cleaning. The openings must be covered with doors.

Chimneys made of asbestos (chrysotile cement pipes) ↑

It is allowed to use chimneys made of asbestos-cement pipes if the temperature of the flue gases does not exceed 300 degrees Celsius.

Chimneys made of steel pipes ↑

It is allowed to use stainless steel chimneys if the temperature of the flue gases does not exceed 400 degrees Celsius.

Avoiding rafters and other obstacles ↑

In the event that the chimney cannot run vertically, SNiP allows small inclined sections with an angle of inclination of no more than 30° and a pipe offset of no more than 1 m. The internal walls of the inclined sections must be smooth. The cross-sectional area of the inclined sections of the chimney must be no less than the cross-sectional area of the vertical sections.

Chimney umbrellas ↑

The mouths of chimneys must be protected from precipitation by umbrellas. The design and method of fastening umbrellas and deflectors should not impede the escape of smoke.

Spark arresters ↑

Chimneys that lead to the roof of flammable materials (soft roofing, ondulin, etc.) must be equipped with mesh metal spark arresters with a mesh size from 1x1 to 5x5 mm.

Fire protection for walls and floors ↑

When installing the stove in a room with a floor made of flammable materials, the floor covering must be protected from the ingress of hot coals. To do this, use a metal sheet of 70*50 cm or more format on asbestos cardboard with a thickness of at least 8 mm.

It is recommended to protect walls or partitions made of flammable materials adjacent at an angle to the front of the stove with plaster with a thickness of at least 25 mm over a metal mesh or with a metal sheet over asbestos cardboard 8 mm thick. The protective layer should start at floor level and end 250 mm above the top edge of the firebox door.

Cuttings and offsets at junctions at junctions of structures ↑

If walls or partitions made of flammable materials are adjacent to a brick chimney or stove, they must be protected by indentations or cuts.

The cut is actually a thickening of the stove or chimney. The thickness of the groove (taking into account the thickness of the walls of the furnaces should be at least 500 mm if structures made of combustible materials are adjacent to it, and at least 380 mm if the structures are protected by plaster or metal sheets against asbestos (see above). The width of the groove should be 70 cm greater than the thickness of adjacent structures.

A setback is a gap between the outer wall of a stove or chimney and combustible structures. The retreat can be open or closed on both sides by a thin partition made of brick or other non-combustible material. If the indentation is made closed, holes with an area of at least 150 cm2 each are created in its lower and upper parts. The retreat floor must be made of non-combustible materials and located 70 mm above the floor level in the room.

Requirements for indent width

Is it possible to install the boiler yourself?

Considering all the dangers that gas equipment poses in case of violation of installation technology, the answer to this question is obvious - it is impossible.

Before installing a gas boiler, you must obtain technical specifications. Otherwise, installation will be considered illegal and fraught with penalties. In addition, independent installation is very dangerous, especially if it is carried out in a high-rise building. There are many sad examples of this, and gas services are carefully monitoring this.

The user has the right to do whatever he wants with any of the other types of fuel, just not with natural gas.

You can install a wall-mounted gas boiler yourself, provided that the user has an understanding of this equipment and the nuances of installation, and strictly complies with the requirements regulated by SNiP. But the first start-up of the unit, insertion into the gas main and adjustment of the equipment must be carried out by specialized gas services.

Ventilation for a boiler room in a private house

As already mentioned, the calculation of ventilation performance is calculated based on the volume of the room. It must be multiplied by 3, add about 30% to the reserve. Let’s get the volume that needs to be “pumped” in an hour.

For example, a room 3*3 m with a ceiling height of 2.5 m. Volume 3*3*2.5=22.5 m3. A threefold exchange is required: 22.5 m3 * 3 = 67.5 m3. Adding a reserve of 30% we get 87.75 m3.

To ensure natural ventilation, there must be an inlet hole at the bottom of the wall, covered with a grille. The exhaust pipe must exit through the roof; it is possible to exit through the wall in its upper part. The ventilation pipe must be installed at the same height as the chimney.

Requirements for exhaust hoods by law

Ventilation rules are enshrined in SNiP. The basic requirement relates to the volume of air exchange - it must provide 3 times air circulation within an hour.

Ventilation of a boiler room in a private house is carried out only according to a preliminary design. Which presents executive diagrams of room ventilation, the type and quantity of necessary equipment, a list of materials and spare parts for installing a chimney.

Basic requirements for air exchange

When purchasing ventilation and smoke exhaust equipment for a gas boiler in a private house, specified in the design documentation, it is necessary to check them for compliance with the quality regulated by legal norms in the territory of the Russian Federation.

Basic legal requirements for installing ventilation systems for a gas boiler in a private home:

Installation of a separate air duct in the ventilation structure.
The tightness of ventilation ducts; all seams must be treated with heat-resistant sealants.
Arrangement of a separate air channel in the ceiling of the combustion room.
Installation of sleeves in wall structures to lead the gas duct from the room to the street.
Connecting no more than 2 gas installations to one chimney.
A distance of more than 300 mm must be maintained between the outer wall and the end point of the flue.
The air supply can be organized both outside and inside the combustion chamber. However, the living room cannot be used as an adjacent room.

Carrot caviar with mushrooms

A very tasty option is carrot caviar with mushrooms. To prepare the preparation, we will use honey mushrooms, which we will first boil in salted boiling water. You need to cook for about half an hour. A sign that honey mushrooms are ready is that the mushrooms will sink to the bottom.

1 kg of boiled honey mushrooms;
300 gr. carrots;
300 gr. onions;
4 cloves of garlic;
1.5 tablespoons of salt;
4 allspice peas;
0.5 teaspoon ground black pepper;
1 bay leaf;
0.5 tablespoon of vinegar essence (70%);
70 ml vegetable oil.

Preparation:

Boil fresh mushrooms, and if we use frozen ones, put them in a colander and pour boiling water over them. Let the liquid drain. Then we pass the mushrooms through a meat grinder or grind them in a blender.
Peel the onions and carrots, rinse and dry. Cut the onion into small cubes and grate the carrots. Fry the onion in a frying pan until it becomes translucent. Then add the carrots to the onion and continue frying for a quarter of an hour. Stir occasionally during cooking. They should be half cooked. Let the fried vegetables cool and grind them in a blender or using a meat grinder. Do not drain the oil remaining in the pan, but mix it with chopped vegetables.
In a large saucepan, mix chopped mushrooms and vegetables, add salt, pepper, peppercorns and bay leaf. Add chopped garlic. Cook the caviar for 15 minutes from the moment it boils. Then pour in the vinegar, stir and turn off the heat.

Errors in selection and arrangement

When building a house, errors in the selected heating system and gas equipment occur at different stages:

the type of boiler was not taken into account during the design - after construction is completed, it may be necessary to rebuild the entire ventilation system;
unsuccessful form - an abundance of turns reduces traction, in some cases provokes the movement of air from the pipe into the room;
there is no possibility of cleaning, which can be hampered by sharp turns and the lack of technological holes;
purchasing materials from different manufacturers - components for composite pipes may differ in geometric dimensions, which leads to air leaks or leaks of combustion products into the room;
non-compliance with the height of the chimney on the roof, leading to reverse draft;
incorrect choice of materials for the pipe;
insufficient insulation.

Guiding documents allow independent construction of chimneys for gas boilers. The gas supply organization will not accept improperly installed chimneys for operation, and hidden defects can lead to accidents. It is necessary to study in detail the rules provided for by the governing documents; if you doubt your abilities, it is better to entrust construction to professionals.

Understanding Cravings: Factors Affecting Cravings

For normal operation of gas appliances, a constant supply of clean air is required, which is provided by natural supply and exhaust ventilation.
The removal of combustion products from gas appliances is provided through a chimney.

To remove gas combustion products into the atmosphere, there must be a certain draft - a force that forces air to penetrate the chimney, and the resulting combustion products to move along the chimney and dissipate into the atmosphere.

The draft depends on the temperature difference between the smoke and the air, the height of the chimney and a number of other factors.

To ensure better draft, the temperature of the exhaust gases must be high. The temperature of exhaust gases from water heaters is 180-200°C. Due to the cooling of the reinforced steel and the suction of air in the draft stabilizer, the temperature drops. When operating chimneys, condensation of vapors from flue gases must be prevented. Wetness of the channel reduces traction, leads to its destruction, and in the winter season it can lead to freezing and blockage of the channel. The temperature at which condensation begins is called the “dew point”. For natural gas combustion products = 60-65°C. The air intake in the draft stabilizer reduces the relative humidity of the exhaust gases, and the dew point also decreases to 40-50 degrees. To exclude condensation, the temperature of the flue gases at the exit from the pipe head is usually taken to be 65°C. The draft decreases with high ambient humidity.

Boiler rooms for solid and liquid fuel boilers

The following types of liquid and solid fuels are used to heat residential buildings:

coal;
fuel oil;
gas oil, gasoline;
diesel fuel;
working off;
kerosene;
wood waste, pellets, firewood;
oil shale;
peat;
petrol;
vegetable or machine oils.

As a rule, floor-standing units are designed for the use of solid or liquid fuel. Loading requires fairly large chambers, and after combustion, waste is generated. Therefore, such boilers are less compact than gas boilers.

When building a boiler room in a private house with your own hands, you must comply with the same requirements as for gas boiler rooms, but with some additions:

solid fuel and liquid boilers cannot be installed in residential premises due to strong odor or dust; for this purpose, an extension or a separate furnace room must be installed;
To install a floor-standing boiler, a concrete foundation with a thickness of at least 50 mm is installed.
there must be easy access for loading, cleaning the boiler, repairing and replacing parts;
there must be at least 2 m from the place where the fuel is placed to the nearest wall;
It is advisable to place the chimney closer to the ridge to create good draft;
smoke exhaust is arranged through a chimney in the main wall or a pipe outside the house, and it should not coincide with the window openings;
the chimney is made of a sandwich pipe with insulation and an internal heat-resistant layer of steel or brick;
You cannot build an attic or living room above the boiler room;
In the room where gas equipment is installed, flammable materials and chemicals that emit flammable vapors must not be stored.

To prevent dust from accumulating in the boiler room, which adversely affects the operation of the equipment, a supply opening is installed at a height of 30 cm from the floor, and an exhaust opening is located under the ceiling. Ventilation of the room should be natural.

You can quickly build a boiler room in a private house with your own hands if you use ready-made modular structures. During their production, all standards and requirements are taken into account.

A mini-boiler house can operate on any type of fuel and heat a residential building or cottage. The structure is installed on a monolithic or prefabricated foundation and connected to the heating system of the building. When using gas, the project must be agreed upon with the gas distribution organization.

Penetration for a metal chimney pipe

Special devices and materials for sinking a metal chimney

Box-shaped ceiling-passage structures

Arrangement of the passage of a metal chimney through a wooden floor structure can be done using a ready-made ceiling-passage assembly, or one made independently, but in compliance with the standard dimensions.

If a ready-made version of such penetration is purchased, then its size is selected according to the diameter of the chimney pipe. The convenience of using a factory box is that its design already includes all the dimensions established by SNiP, so you don’t have to rack your brains about it. All that remains is to open an opening in the ceiling for penetration, and then strengthen its thermal protection of the surfaces.

Such pass-through units are sold in specialized stores. Sometimes they are immediately supplied with sets of pipes for installing a chimney

You can make a box penetration yourself. It is made from different materials - it can be a steel sheet with a thickness of at least 0.5 mm, alone or in combination with mineralite, asbestos sheet, with mineral basalt wool foiled on one or both sides. If the box is purchased or made of metal, then it will need to be thermally insulated with regular or foil-coated mineral wool, vermiculite, or expanded clay.

If you decide to make such a penetration yourself, then the diameter of the hole in its central part should be approximately 0.5 mm larger than the outer diameter of the pipe. This is done so that the metal pipe passes freely through the box, but at the same time, the gap between them is not too large.

To make a penetration, you can use the dimensions shown in the illustrations and presented in the table:

The main dimensions of the passage box for a metal chimney

Recommended dimensions of the passage box

Letter designation of structural elements and size in mm
d - hole diameter	L - length of the side of the decorative panel of the box	G - width of the sides of the box	H - box height
205	580	370	310
215	580	370	310
255	580	450	310
285	580	450	310

If the passage box is made only from foil-coated mineral wool 50 mm thick, then cutting the elements for it is best done according to pre-made templates. The parts are assembled into a single structure using heat-resistant foil tape. Having chosen this option for cutting, you must not forget that you will also need to purchase or manufacture one or two metal panels for it. One of them is fixed to the ceiling surface, flush with it, and the second (optional) covers the thermal insulation material from the attic side.

This box penetration is made of dense foil-lined mineral wool

Another option for penetration could be a box made of metal sheet, insulated with the same foiled mineral wool. This insulation is cut into strips with a width equal to the height of the resulting box and laid along the walls at the end, with the foil side facing the pipe. The space of the box free from the pipe must be tightly filled with thermal insulator.
The box can also be made of mineralite (fiber-reinforced concrete slabs) 10 mm thick. Structural elements are also cut out using prepared templates and then fastened together using metal corners. A smaller box made of a metal sheet 0.5 mm thick is installed and secured into a casing made of this material.

Minerite box penetration with metal liner

There should be a gap of 10÷15 mm wide between the walls of the outer and inner boxes, which is filled with basalt insulation, and the space around the pipe can be filled with vermiculite, expanded clay of fine or medium fraction, or the same mineral wool. The holes through which the pipe will pass must have the same diameter in both boxes. To aesthetically design the penetration from the side of the living room, you can also use a metal plate, or leave the fiber cement board open. After completing the installation work, it will be easy to paint the slab facing the living space to match the color of the ceiling.

Video - Manufacturing and installation of a homemade box-shaped penetration for the chimney of a sauna stove

Heat-resistant materials for making penetrations

The characteristics of heat-resistant materials that are used to insulate the ceiling penetration deserve a few minutes of attention. They differ in some qualities from conventional insulation made on the same basis.

Strong, durable, environmentally friendly material - mineralite

Minerite is an absolutely non-flammable material, which is also called fiber cement boards. It is often used for wall cladding in areas where stoves are installed and where chimneys pass through.

Minerite prices

mineralite

This material is not only resistant to extremely high temperatures, but also moisture-resistant, has good mechanical strength, and does not contribute to the formation of mold and mildew colonies. Minerite is an environmentally friendly material, therefore at elevated temperatures it does not emit fumes harmful to human health.

Minerit LV panels are used to make screens installed in the grooves and on the walls around stoves and chimneys. In addition, such panels are also suitable for the construction of fire-resistant partitions.

Non-combustible slabs made of basalt wool and covered with aluminum foil are used for fire protection of walls and passages around chimneys.

High-density basalt mineral wool slabs with foil coating can also be used as a material for the manufacture of ceiling penetrations

This material is made from environmentally friendly components and is highly resistant to aggressive biological and chemical influences. In terms of its thermal insulation properties, mineral wool is certainly many times superior to mineralite, but is inferior to it in mechanical strength and durability.

High-quality basalt slabs do not accumulate moisture, and they do not create a favorable environment for the settlement of rodents and insects, or the appearance of microflora colonies. This type of insulation belongs to the flammability group G1. (And this is only due to the adhesive layer that holds the foil covering, since in its “pure form” basalt insulation can be classified as a completely non-combustible material). Basalt slabs from different manufacturers may differ slightly in the upper limit of the operating temperature range. But in any case, it ranges from +750 to 1100 degrees, which should be more than enough for the chimney duct.

Prices for basalt slabs

basalt slabs

Installation of penetration for a metal pipe

Before installing the penetration into the window cut out for it in the attic floor, it must be prepared, additionally strengthened, if necessary, and insulated from high temperatures.

The installation of a box penetration is always preceded by checking and preparing the ceiling structure for this operation

The first step is to additionally monitor the condition of the opening and the surrounding parts of the ceiling structure. This is done to make sure that the box will be securely fastened in it.

The box penetration must be firmly fixed to the ceiling structure. It is, of course, positioned so that it is between the floor beams (it is clear that these issues regarding the placement of the stove in the room are always thought out in advance). Beams can become a reliable basis for fastening the penetration, located on the sides of it.

However, it often happens that the floor beams are located too far from each other and therefore the floor “pie” in the area where the pipe passes does not have the necessary rigidity and will need to be strengthened. Another option, exactly the opposite, is that the spacing of the installed beams is too frequent and does not leave enough free space to accommodate the box penetration.

In any of these cases, after removing the desired section of the coating, you can mount the frame in accordance with the dimensions of the box using a wooden beam. The cross members of this frame are rigidly cut into the floor beams. If necessary, if the beams are too widely spaced, additional longitudinal support beams can be used in the frame. An example of creating such a frame is shown in the illustration.

An example of preparing an attic floor frame for installing a box penetration for a chimney.

Similar checks and strengthening (revision) of the frame will be necessary if the chimney is installed in an already built house. However, as a rule, the installation of stoves and, therefore, the installation of chimneys are planned in advance. And during the installation of floor beams during the construction of a building, such a frame is provided in advance for the subsequent installation of a box penetration.

Further, all wooden parts of the ceiling structure located around the perimeter of the cut window for penetration must be additionally treated with a special impregnation. The fire retardants included in the composition will increase the fire-fighting characteristics of the created unit. Further operations are carried out only after the treated surfaces have completely dried.

Installation of the penetration must be carried out with high precision so that the verticality of the chimney pipe is not disturbed

The next step is to install a penetration box into the cut opening from the side of the room. The edges of its bottom part are securely screwed onto the ceiling surface with self-tapping screws.

But this operation should be performed only after carefully monitoring the location of the round opening for the chimney relative to the heating device. It is unacceptable for even a slight deviation to cause unevenness or a “kink” in the installed pipe. This will create unnecessary stress in its walls and may well lead to insufficient sealing at the joints.

It is best to accurately adjust the position of the box passage using a plumb line to ensure that the axis of the pipe being installed is vertical.

Next, the lower part of the chimney pipe is assembled, starting from the outlet pipe of the stove (boiler).

It is very important - whatever the distance from the stove to the ceiling, and whatever components are used, never, under any circumstances, the connection of two elements (pipes) of the chimney should fall on the ceiling. Moreover, the minimum distance from such a connecting unit to the surface of the ceiling (no matter from below, indoors, or from above, from the attic) must be at least 300 mm.

The requirements for the correct location of the interfaces of individual pipes are important, of course, from the standpoint of ensuring visual inspection. But the main predetermining factor of such a considerable (300 mm) distance from the ceiling is the continuing likelihood of a breakthrough of hot gases in these, let’s be honest, the remaining most vulnerable places of the prefabricated metal chimney.

The next stage of work can be carried out from the attic or living space, depending on how it is more convenient to install the next section of the pipe. If the work is carried out from the attic side, then the next part of the chimney pipe is passed through the hole and fixed to the lower, already mounted section.

An approximate diagram of the relative arrangement of parts of the ceiling penetration assembly.

When the pipe is brought into the attic, you can proceed to filling the penetration box with heat-insulating material. If one of the bulk thermal insulation materials is selected, and there are small gaps between the pipe and the border of the round hole, they can be sealed with basalt wool or plastic clay, and then the insulation can be poured on top.

The ceiling penetration box is filled to capacity with expanded clay

It is best to choose expanded clay or vermiculite from bulk heat-insulating materials. Ordinary sand is used for backfilling only as a last resort, since it has too fine a fraction, is heavy and has excessively high thermal conductivity for such a function. Expanded perlite sand is not particularly convenient to use in such conditions due to its excessively high “volatility”.

The easiest way is to fill the box with heat-resistant basalt wool, since it has the lowest thermal conductivity. When using mineral wool mats, the box from the attic side should not be completely sealed in order to have free access to the pipe along its entire length. If the pipe goes to the second floor, then the hole in its floor with insulating material around the chimney can be closed with a metal sheet, screwing it to the floor.

The selection of photographs below demonstrates the installation of a homemade box-shaped penetration made from dense slabs of foil-coated basalt insulation.

Installation sequence for a homemade box penetration for a chimney pipe

— The first two fragments: this is a finished homemade tunnel from different angles.

— Third fragment: a window was cut out in the ceiling to install the penetration. Please note: to ensure maximum safety, the master also filled the resulting gap between the ceiling covering and the attic floor with mineral wool.

— Fourth photo: The penetration box is inserted into the prepared opening and fixed from below.

— Fifth fragment: After installing the section of pipe leading into the attic, the penetration is closed from below with a metal panel. It is securely fixed to the ceiling with self-tapping screws, completely covers the edges of the window of the passage unit, holds the heat-insulating box well in the ceiling and provides mechanical protection for the mineral wool panel, which is not particularly durable.

— Sixth photo: Continued installation of the chimney pipe. The gap between the pipe and the box will be tightly filled with mineral wool. Since the attic in this case is “inhabited”, the passage unit will be covered with a decorative metal plate.

And in the video below, the master did without creating a box-shaped structure at all.

Video: fireproofing of a chimney pipe in a passage through a wooden ceiling

Room requirements for installing a gas boiler:

the room for installing a gas boiler must be at least 4 m2;
the height of the ceilings in it is at least 2.5 m;
the width of the external door is at least 80 cm;
You need a window for natural light and an opening for the flow of outside air.
the room in which the boiler is installed must have a separate exit to the street.

It is also necessary that the door to the room opens freely or is trimmed; an influx of oxygen is required for the combustion of the wick and burner.

When constructing chimneys, to ensure draft and prevent blowing out leading to the extinguishing of the flame, it is necessary to extend the upper cut of the chimney above the wind support zone. The height of the chimney above the roof of the house is set depending on the distance:

at least 0.5 m above the ridge, if the pipe is located at a distance of up to 1.5 m from the ridge;
not below the line, the level of the ridge, if the pipe is located at a distance from 1.5 m to 3 m;
not lower than a straight line drawn from the ridge down at an angle of 10″ to the horizon, when placing pipes at a distance of more than 3 m from the ridge of the roof.

The chimney must have a cross-section in accordance with the passport for the installed equipment, but not less - for a boiler with an open combustion chamber and a power of up to 30 kW with a diameter of 130 mm, for a boiler with a 40 kW - 170 mm.

The chimney must have a minimum of elbows and bends, and its internal diameter cannot be less than the diameter of the boiler neck.

It is also necessary to have a natural ventilation channel in the upper part of the room.

If the gas boiler is volatile, then in accordance with the requirements it must have a separate circuit breaker. You can also install a differential circuit breaker (RCD), which protects a person from a short circuit to the body, and the boiler must be grounded.

When installing a boiler in a separate room without permanent presence of people, for example, a built-in or attached furnace room, according to current building codes, a gas analyzer must be installed in the room, which will warn of a leak and automatically shut off the gas supply using an emergency electric valve. An unconditional requirement is also the mandatory presence of a temperature shut-off valve at the gas pipeline inlet in the room for emergency shutdown of the gas supply in the event of a fire. All equipment is subject to annual maintenance by specialists.

Choosing a gas boiler.

The power of a gas boiler is calculated at the stage of building a house, since the diameter of the chimney and a number of parameters of various engineering systems depend on it.

Gas boilers can be steel or cast iron.

A steel boiler is approximately two times lighter than a cast iron boiler of the same power and volume.
The service life of a steel boiler is 10-15 years, cast iron up to 50 years.
A cast iron boiler is afraid of sudden changes in temperature and therefore almost always fails if it is turned on without water, or without warming up in a very cold room after a long stop.
A steel boiler will rust if it is left without water after shutdown.

Gas boilers are available in floor-mounted and wall-mounted versions.

The body of the wall-mounted boiler contains a gas burner, a heat exchanger, a circulation pump, an expansion tank, a pressure gauge, a thermometer and a boiler safety system. Wall-mounted boilers are always volatile, that is, they cannot work during a power outage. In connection with this, for stable and long-term operation, it is recommended to use a voltage stabilizer or surge protector. In this case, you need to remember 2 basic requirements. Read more…

Basic rules for installing a chimney

The installation of a gas boiler should only be carried out when all the rules for installing a chimney are observed.
It is necessary to ensure the correct selection of chimney parameters, on which the further operation of the gas boiler depends.
It is important that all installation work is carried out by highly qualified workers, while observing all fire safety rules.
All manufacturer's recommendations must be followed.
It is necessary to choose the diameter of the chimney duct the same diameter as the device itself or perhaps a little larger.
The air flow in the chimney duct should have a speed of 10-25 meters per second (NPB-98).

Rules for installing and connecting gas boiler equipment

Before you begin installing gas equipment of the type in question in a private home, you will need to prepare certain documents, and then carry out the required actions, which are the rules.

Rules for installing gas boilers:

A contract with the supplier regarding the supply of natural combustible material will be required;
Installation of gas equipment must be carried out by an installation organization that specializes in providing this type of service;
Technical conditions, as well as the equipment installation project, must be agreed upon with the gas service representative at the location where the system is installed. Project documentation, as a rule, is developed by specialized institutes with the appropriate license for this type of activity;
The heating system must be pressurized to P = 1.8 atm;
An engineer from the regional or district gas service comes to the site, after which he checks the correct connection of natural gas in the furnace and kitchen. The engineer also checks compliance with the requirements put forward by equipment of this type;
The valve opens only if the engineer has not identified any violations;
There must be no air in the system;
All connections are checked for leaks;
A voltage stabilizer is installed, as well as an uninterruptible power supply;
It is not allowed to add antifreeze to heating water, as this can damage the sealing gaskets and then lead to leaks in the home heating system.

The following are the features of installing a wall-mounted gas boiler.

Basic regulatory documents

Requirements for gas boiler houses are given in the following regulatory documents in force in 2022:

SP 62.13330.2011 Gas distribution systems. (Updated edition of SNiP 42-01-2002) (mandatory for use according to post.985)
SP 402.1325800.2018 Residential buildings. Rules for the design of gas consumption systems (acting on a voluntary basis under Order 687)
SP 42-101-2003 General provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes (of a recommendatory nature)
Instructions for the placement of thermal units intended for heating and hot water supply of single-family or semi-detached residential buildings (MDS 41-2.2000) (is advisory in nature)

Let us highlight the most important requirements (point by point) that must be met when designing and building a gas boiler room in a house, as well as when designing the route for laying a gas pipeline:

According to SP62.13330.2011:

pp. 5.1.6* Gas pipeline entries into buildings should be provided directly into the room in which gas-using equipment is installed, or into an adjacent room connected by an open opening.

It is allowed to provide for gas pipelines entering apartment kitchens through loggias and balconies, provided that there are no detachable connections on the gas pipelines and access is provided for their inspection.

It is not allowed to enter gas pipelines into the premises of the basement and ground floors of buildings, except for the introduction of natural gas pipelines into single-family and semi-detached houses and industrial buildings, in which the introduction is determined by the production technology.

pp. 5.2.1 Gas pipelines should be laid at a depth of at least 0.8 m to the top of the gas pipeline, casing or ballasting device, except in specified cases. In those places where traffic and agricultural machinery are not expected, the depth of laying steel gas pipelines must be at least 0.6 m.

pp. 5.2.2 The vertical distance (clear) between the gas pipeline (case) and underground utility networks and structures at their intersections is recommended to be taken in accordance with Appendix B* SP62.13330.2011.

According to Appendix B*, when laying a gas pipeline underground (gas pressure up to 0.005 MPa) and the most common communications on the land plot of a private house:

Vertically (at intersection) with water supply and sewerage - at least 0.2 m in clear space (between pipe walls)
Horizontally (parallel) with water supply and sewerage - at least 1 m
Horizontally (in parallel) with power cables up to 35 kV - at least 1 m (when installing a protective wall, it can be reduced to 0.5 m)

The main requirements for the chimney of a gas boiler

Diagram of a gas boiler.

It is recommended to place the pipes in the internal wall of the building, which is permanent. If the chimney is located outside the building, insulation is required to prevent freezing. When making a channel inside an outer wall, the thickness of the brickwork should be at least 1.5 bricks, and in severe winter conditions - 2.5 bricks.
The chimney of a gas boiler must be positioned vertically with a possible slight slope of no more than 30 °. Extensions and contractions are not allowed.
The cross-sectional area of the duct must be larger than the cross-sectional area of the gas equipment to which it is connected.
The gas boiler must be connected to the chimney through a special corrugation or using steel pipes with a heat-resistant enamel coating.
The chimney pipe through which the gas boiler is connected to the chimney must have a vertical section at least 0.5 m long. The requirements do not allow more than three turns of the chimney pipes.
The connection between the gas boiler pipe and the chimney must be sealed.
All components must fit tightly together, be sealed and airtight. For this purpose, sealing agents that are resistant to high temperatures are used. The possibility of bending of pipes at their connections must be excluded.
In rooms with a height of about 3 m, the length of the horizontal sections of pipes that make up the chimney should not exceed 3 m.
The slope of the pipe towards the gas boiler is allowed at least 0.1 °
There must be a container for collecting condensate with a window for cleaning. It is usually located below the point where the chimney pipe enters the channel.
The permissible distance between surfaces made of heat-resistant materials and connecting pipes is 5 cm or more, and in the case of flammable surfaces - at least 25 cm.
The chimney above the roof must rise no less than 50 cm if the pipe is located from the edge of the roof ridge at a distance of no more than 1.5 m. When the pipe is removed up to 3 m, it is aligned level with the roof ridge.
If there is a flat roof, then the height of the chimney above its level should be at least 1 m.

Forbidden:

Make channels from loose, porous, slag concrete and other materials;
Lay smoke exhaust pipes from stoves/appliances through living rooms;
Install a damper when connecting devices with draft stabilizers to the chimney itself;
Install the smoke duct outlet through the external walls:

— in entrances, covered passages, arches;

- closed balconies, bay windows, loggias;

- in monument buildings, without permission from the special department that protects them;

— through the walls of buildings facing streets/squares that have urban, historical and architectural value;

- in buildings in which the installation of gas appliances is prohibited in accordance with DBN No. V.2.2-9, SNiP No. 2.08.01, SNiP No. 2.04.05.

Openings of smoke ducts on the outer wall of buildings when combustion products exit from the heating device through the outer wall without vertical. channel should be placed in accordance with the gas installation instructions. manufacturer's equipment, but at a distance not less than those indicated in the following table:

Chimney pipes must be checked at least twice during the heating season and must be performed by highly qualified workers. They should also conduct an inspection of the chimneys themselves.

A chimney for a gas boiler according to SNiP will always work efficiently and, most importantly, taking into account all legal standards!

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Requirements for free-standing combustion chambers

Separate boiler houses are built for powerful heat generators, the operation of which requires an enhanced safety regime.

Requirements for furnaces built separately from a residential building:

The premises are equipped with concrete floors or covered with fireproof finishing. For equipment weighing over 200 kg, a reinforced base with a height of 15 cm is prepared.

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Heated water enters the house through an insulated pipeline with low heat loss. A free-standing furnace does not take up the usable space of the house, is safe to use and does not disturb the architectural appearance of the building. Can be used for heating a group of buildings, for example, a house, a bathhouse and a greenhouse.

Requirements for doors

Two types of doors are used in furnace rooms:

external without reinforcement for access to the street;
internal fire protection for communication with residential premises.

External doors should be easy to break off their hinges in the event of an explosion. Then the energy will be directed outward and cause less destruction than with a rigidly and firmly fixed canvas. But in any case, you need to protect the premises from strangers who could enter and damage expensive equipment.

Interior doors are designed to contain flames in a fire for 15 minutes. Type 3 fabrics with a fire resistance limit of EI 15 comply with the standard. They retain their integrity and thermal insulation properties for a period of time sufficient for the evacuation of people from the house and the arrival of rescue services.

Boiler room ventilation

The requirements for a boiler room in a private house are very strict regarding ventilation. Combustion products formed when burning fuel are dangerous to humans. Inhalation of carbon monoxide leads to severe poisoning. High concentrations cause paralysis and even death.

Gas leaks in the network create a danger of explosion. Methane, propane and butane are heavier than air. They accumulate in the lower level of the room. That is why it is recommended to install gaps near the floor under the outer door or grated exhaust openings in the wall to remove hazardous substances. For every 10 kW of unit power, 0.01 m² of cross-sectional area of the supply channel is required.

Natural ventilation, recommended by the standard, includes supply and exhaust ducts to replace the air in the room. Their area is calculated based on the triple volume of the room and selected using special tables, diagrams or using online calculators.

For every 10 kW of power, 0.01 m² of cross-sectional area of the supply channel is required.

Combustion products are discharged through a chimney or a coaxial pipe built into the wall. In the first case, the cross-section of the channel must correspond to the diameter of the boiler pipe. The optimal shape is a circle or oval.

The chimney walls protect against condensation. Warm air, moving through the pipe, cools, which leads to the precipitation of water vapor in the form of dew. In winter, the moisture freezes and the channel narrows. This contributes to the deterioration of the removal of combustion products.

Protection against condensation is carried out by lining the chimney or installing a stainless steel pipe inside. Angles and turns must be smooth, and the joints of channel elements must be sealed.

In other cases, the ventilation duct may be lower. Separate smoke removal systems are installed for the two units.

Pipe connections

Installation requires welding.
Quality control of welding work is regulated in SNiP 3.05. 03.85 5. Welding heating pipes

Gas water heaters and other gas appliances must be connected to the chimney using pipes that are made using roofing steel.
The length of connected pipes should not exceed 3 meters in new buildings and more than 6 meters in existing ones.
The slope of the pipe in relation to the device must be at least 0.01.
On smoke exhaust pipes, no more than 3 bends are allowed, the radius should not be less than the diameter of the pipe.
The connection of the pipes must be tight; the entry of one pipe into the other must be at least half the diameter of the pipe.
If the pipes are made of black iron, they require painting with fire-resistant varnish.

Is it possible to connect 2 boilers or more to one chimney?

You can connect no more than 2 boilers (heaters, stoves...) to one chimney, but only in existing houses. In others, each gas boiler must be equipped with its own chimney.

In existing houses, the cross-section of the chimney must correspond to the performance of the two boilers that are connected. Also, connections must be at different levels, and the distance between them is at least 0.75 meters. Or the connection can be made at one level, but from this place and above 0.75 m in the chimney a cut must be made to ensure the proper cross-section (which is rare in practice).

Or, no more than 2 boilers (water heaters, furnaces) can be connected, but they must work in turns, their simultaneous operation is not allowed, which must be provided with appropriate electrical (mechanical) protection, and the cross-section must correspond to the unit with high requirements.

Thus, it is possible to include the main and backup heat generators, or a boiler and a water heater, in one chimney, for example, if there is a blockage from their simultaneous operation.

More air supply requirements

But the operation of an atmospheric boiler must be ensured by a sufficient amount of air entering the room, unless the unit itself takes this air from the street through a separate pipe. Also, the air supply to the room and exhaust ventilation should ensure three times the air exchange within an hour. As for the inflow, it is allowed to enter from other rooms of the building, for which an inlet opening with an area of at least 200 cm2 is created in the door (structure) of the boiler room.

Or such a supply hole is made to allow air to come in from the street. But in order to prevent icing, which will inevitably occur, you can make an oblong box inside the room along the wall, descending from top to bottom, through which the supply air, entering the room, would be heated with heat, and the condensate would flow into a container and drain into the sewer...

Types of boilers and smoke exhaust ducts

Gas boiler with coaxial chimney

The industry produces various models of gas heating boilers, but all types are built in two possible designs: with an open or closed chamber for gas combustion.

It is better to decide which boiler to purchase at the stage of designing a house. The chosen scheme determines how and where to build the boiler room, as well as how combustion products will be removed.

The project must be agreed upon with the gas supply organization - if construction technology is violated or unacceptable materials are used, gas equipment will not be put into operation, and alteration of the gas exhaust system may require significant financial costs.

Open chamber boilers

By design, devices with an open chamber are simpler than devices with a closed type.

Oxygen for fuel combustion is supplied from the surrounding space. This feature imposes additional requirements on the organization of room ventilation.

Equipment installation is carried out only in a separate room. To ensure operation, two channels are built to supply air and remove products from the burnt gas.

Among the advantages is the relative simplicity of the design without additional fans, and therefore without “extra” mechanical parts that are most susceptible to wear. The disadvantages should be considered lower efficiency and the need to build a vertical chimney at a level above the roof ridge.

Features of equipment with a closed chamber

In a coaxial chimney, air is sucked in through one pipe and comes out through another - internal

Air is forced into gas boilers with a closed chamber. The chamber does not communicate with the room air, and the exhaust gases are removed by a supercharger.

Boilers with a closed chamber are economical, do not require the installation of vertical channels, and one coaxial pipe is used. Combustion products are removed through the internal insert, and external clean air enters through the cavity between the walls of the pipes.

To remove gases, there is no need to build vertical structures, which reduces the cost of the estimate. On the other hand, this type of boilers and pipes requires more frequent maintenance. Turbines periodically fail, which entails additional operating costs.

Types of chimneys depending on material

Brick pipe is used very rarely nowadays. To install such a pipe, the construction of a supporting foundation is required. Over time, the brick undergoes destruction from the inside and can allow a certain amount of gases to pass through.

For some interiors, a decorative brick chimney is used, but a stainless steel pipe is laid inside. The operation of a mixed chimney is actually quite effective.

Chimney made of steel pipe

Single pipe is used for insertion into a brick structure, for repair work or for temporary testing installation.
A double-wall pipe or sandwich is very often used for a chimney. Its principle is based on the operation of large and small pipes nested one inside the other. The gap between their walls is filled with insulation, which prevents condensation from forming on the walls of the chimney.
The coaxial version of the chimney is used in those heating systems when combustion requires air supply and smoke outflow at the same time. Chimneys designed for double action have two pipes, as in the double-walled version, only the space between their walls is not filled with insulation, but serves to move fresh air. Smoke is removed along the inner diameter.

https://youtube.com/watch?v=iXYpDw4NjmA

Prefabricated elements for steel chimney of gas equipment

Connecting adapter couplings for connecting the outlet of a gas boiler and a pipe.
The main pipes, produced for ease of installation, are 1 m long.
A tee for cleaning and checking pipe clogging, installed on a horizontal section.
A tee for collecting condensate, mounted at the point where the chimney turns to a vertical position.
Angles for turning pipes from a gas boiler.
Compensator to soften the linear expansion of the chimney when temperature changes.
A unit for designing a channel exit through the ceiling.

Conditions for the installation of smoke ducts for gas boilers in accordance with SNiP

A separate chimney should be provided for each gas device. As an exception, it is allowed to connect two boilers to this smoke removal system. But this can be done with an interval of 0.75 m from the previous insert.

Ensure mandatory sealing of pipes and their connections to prevent carbon monoxide leakage into the interior of the house.

Take all measures to remove condensate from the pipes. To prevent its formation, it is recommended to insulate the outer sections of the pipes.

The entire length of the internal cavity of the chimney must be free from cluttering objects, dirt and soot. All pollution leads to decreased cravings.

The size of the pipe cannot be smaller than the size of the outlet from the gas boiler; the same width or larger is allowed. A round pipe cross-section is considered ideal, sometimes rectangular or square is possible.

It is not recommended to place various umbrellas and canopies on the top of the chimney on the roof. All of these devices reduce draft and can lead to backdraft under certain weather conditions.

What else you should know about gas boiler chimneys

No more than two connection points for gas appliances are allowed to be connected to one chimney, which can be located either on the same or on different floors, but combustion products must be introduced into the duct at different levels and no closer than half a meter from each other. It is also possible to enter at the same level, but if there is a cut inside the channel to a height of 50 cm. In this case, the cross-section of the channel must be determined, providing for the simultaneous operation of all gas appliances that use this chimney.

The optimal shape for a chimney is a cylinder; in addition, oval and square shapes are allowed. But it should be remembered that square pipes have low traction. This is because the swirls that form in the corners trap smoke and cause soot to form. This may negatively affect the operation of heating devices.

Modern gas boilers have fairly high efficiency values, reaching 95%. Therefore, the temperature of the resulting gases is quite low, which contributes to the formation of condensate in large quantities. Its aggressive influence contributes to destruction. Therefore, it is recommended not just to line the pipes with brickwork, but to make a liner or lining of the channel.

When making a liner, a single-wall pipe made of stainless, acid-resistant steel is placed in the brick shaft, which protects the brick from destruction.
A flexible hose is installed to line the channel. This method is used for chimneys that have non-standard sizes or shapes.

The requirements allow for the installation of chimneys in the walls together with ventilation ducts. However, they should be separated by sealed partitions along the entire height. Partitions must be made of wall material and have a thickness of at least 1.2 cm.

Installation of chimneys for wall-mounted gas boilers

To remove combustion products from a wall-mounted boiler, it is allowed to install a wall-mounted (coaxial) chimney. It consists of two pipes inserted into one another, without a layer of insulation. This type of device ensures the removal of combustion products and at the same time the flow of fresh air. The distance from the ground to the pipe outlet must be at least 2 m.

There are modern models of gas heating boilers that have a sealed fuel combustion chamber. Their work is designed in such a way that the installation of traditional chimneys is not required.

How to remodel an old chimney?

If a gas boiler is included in a long-existing heating system instead of a conventional stove, the brick chimney does not have to be completely rebuilt. It can be upgraded by sleeving. There are two ways to do this.

Method number 1. Install a stainless steel pipe at the base of the existing chimney.

The pipe should be selected so that its height is equal to the height of the old chimney, and its diameter matches the boiler pipe. The gap between the walls of the existing chimney and the pipe is filled with heat-insulating material such as foam glass, expanded clay or perlite.

Method 2. Apply Furan-Flex technology. This option is more expensive than the first, but the diameter of the chimney remains unchanged. The material is frost-resistant, does not corrode, the diameter ranges from 6 to 100 cm.

FuranFlex technology allows you to modernize or repair a chimney with a slope of maximum 30⁰ quickly and efficiently

The technology itself consists of placing an elastic pipe inside the chimney under pressure. The pipe takes the shape of a chimney, then hardens and becomes a continuous, seamless shell that does not allow smoke or condensation to pass through.

What affects the efficiency of a chimney?

Perhaps the question is posed somewhat incorrectly from a professional’s point of view. Since the health and sometimes even the lives of people depend on the effective operation of the combustion product removal system, it is more advisable to consider the requirements for the chimney of a gas boiler.

A chimney of any design must be made in accordance with the requirements of SNiP 2.04.05-91, as well as DBN V.2.5-20-2001. Otherwise, the chimney will be installed incorrectly and the heating equipment will be connected to it. And this, in turn, calls into question the safety of operation of the entire heating system. These documents clearly regulate the design of boiler chimneys. These documents are subject to careful study, since violation of the standards set out in them will certainly lead to problems with the gas industry.

If we briefly outline the requirements for chimneys of gas boilers, then first of all you need to pay attention to the following points:

Good traction is the key to efficient use of thermal energy from gas combustion.
Correct design of the condensate collector - excess moisture should not accumulate on the walls of the chimney duct.
It is prohibited to install deflectors, fungi, etc. on the chimney head. These elements reduce the efficiency of removing combustion products, and there is a risk of carbon monoxide entering the room.
Requirements for chimneys of gas boilers require maximum attention to installation work. Particular emphasis should be placed on the tight fit of structural parts at the joints, that is, maximum tightness must be achieved. This will prevent hot gases from penetrating beyond the chimney.
It is allowed to use common connecting flue pipes for several units.

From the outside it appears that the chimney is made of brick. In fact, it’s just a decoration, and it’s located inside the pipe

What to consider when installing a column

Let's consider the basic installation rules that must be observed when carrying out work:

The room must have a minimum area of 7.5 m2.
The minimum pressure readings should be 0.1 atm.
Sufficient ventilation must be ensured.
The equipment should be installed on a wall that has been protected with non-combustible materials.
Placement directly above a gas stove is prohibited. A minimum distance of 10 cm must be maintained between such devices.
A mandatory requirement for installing the device is the presence of a chimney. The diameter of the pipe should be from 120 mm.
The ceilings in the room must be at least 2 meters high.
There must be a gas meter in an apartment with a water heater.

Tools required for installation

The device of a classic geyser

To install a gas water heater in an apartment, you need the following tools:

Adjustable wrenches (two wrenches required).
Two open-end wrenches (27 by 30 and 32 by 36).
Sealant. Unipack is perfect.
Tow or FUM tape.

To carry out installation work, you need to prepare the following materials:

Galvanized pipe, 1 meter long. Often such materials are supplied complete with heating equipment.

Gas hose (its dimensions are specified in the documentation that comes with the kit).
A filter designed for rough water purification. Keep in mind that the service life of such equipment directly depends on the quality of the water.
A rosette ring required to lead out the entrance to the chimney.
Dowels that will secure the equipment to the wall.

Installation work step by step

When the chimney and water supply are prepared for the installation of equipment, you can proceed directly to its installation. Replacing a gas water heater is carried out in several stages:

Mark the equipment attachment points. Here you should take into account the minimum length of the chimney, which is 50 cm for rooms with a ceiling height of 2 meters and 25 cm - where the ceiling height is 2.7 meters or higher.

Diagram of the correct location of the speaker in the kitchen

Holes are made in the wall according to the markings.
Hooks are installed to hold the column.
Now the device can be hung on the wall.
We take PVC pipes and connecting rods, through which the pipeline is connected to the inlet and outlet of the column.

The video shows instructions for installing a geyser

Correct connection of the column to gas and water supply

At the last stage of installation, gas is supplied to the device. To do this, take a flexible hose: one end is screwed to the gas supply valve, and the other to the gas inlet into the column. Next, you need to crimp the connections and treat them with a soap solution to check for leaks.
We supply gas to the system. If there are no bubbles in the areas with the applied solution, then you can safely put the system into operation.

A correctly installed and ready-to-use geyser

What material

A chimney for a gas boiler in a private house can be made from different materials. The main requirement is resistance to chemically aggressive substances, inability to pass gases. Traditionally, several materials are used. Let's talk in more detail about the advantages and disadvantages, as well as the assembly features of each of them.

Brick chimney

Today this is no longer the most popular type of chimney. It turns out to be heavy and requires a foundation at high altitudes. In addition, laying a brick chimney takes a lot of time.

However, this type of chimney has a number of negative qualities. First, its inner walls are not smooth, which contributes to the accumulation of soot and impairs traction. Secondly, brick is hygroscopic. Therefore, the condensate flowing down the walls is absorbed, which contributes to rapid destruction.

Construction of a brick chimney for a gas boiler with a metal sleeve insert

To solve these problems, a smooth pipe of suitable diameter is inserted inside the brick chimney. This is usually a stainless steel or asbestos pipe. When building such a combined chimney, attention must be paid to the following things:

The joints of the liner pipe must be made airtight. If these are ordinary or sandwich pipes made of stainless steel, everything happens as standard - we collect the chimney using condensate. If the liner is made of asbestos-cement pipes, you will have to take care of the tightness of the joints. Moreover, covering the joint with cement is not an option. Such a connection is not sealed in any way - condensation will be absorbed. We will have to come up with sealed clamps and use hydrophobic (water-repellent) compounds. Moreover, they must also be chemically resistant. As an option, you can consider coating the joints with heat-resistant sealants with an operating temperature of about 200°C.
To ensure that condensation forms as little as possible, it is better to insulate the pipes (even inside a brick casing). To do this, it is advisable to use insulation that is not afraid of getting wet.
A condensate collector must be attached to the liner pipe below. Access to it must be free.

If you make a chimney for a gas boiler according to these rules, then even with abundant condensation it will be easy to deal with.

Stainless steel - single wall pipes and sandwich

Modern gas boilers are designed so that the temperature of the flue gases at the outlet is not very high. Therefore, condensation always forms. With good draft, most of it flies into the pipe; with good insulation, the remaining part evaporates. So it turns out that liquid is not always present in the condensate collector. But condensate itself is formed when the gas boiler is running all the time. Sometimes in larger quantities, sometimes in smaller quantities. In this regard, the requirements for stainless steel for a chimney are high: it must withstand prolonged contact with caustic substances. These requirements are mainly met by food grade stainless steel. Yes, it costs a lot, but only it will serve for years.

Sandwich pipe structure

Now let’s talk about whether to make a chimney for a gas boiler from a single-wall pipe or from sandwich pipes. In order for condensation to form in minimal quantities, it is desirable that the chimney does not cool down. That is, it needs to be insulated. And although the sandwich chimney has a lining made of insulation, when laying it externally (on the street) it is also better to insulate it - it will last longer, the draft will be better. But in this option, less insulation will be required - one layer, whereas a regular pipe may have to be wrapped in two or even three layers. So the costs of installing a chimney from a single-wall stainless pipe and sandwiches will be comparable. It’s just that in the first case you will have to use more insulation, and in the second less.

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-flammable material.

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

Assemble the lower part of the attached chimney, including 2 tees and a condensate drain section. Attach the horizontal section going into the hole.
Try the assembly on the wall and determine the location for mounting the support pad. Secure it and install the lower part, leading the pipe into the wall. Maintain verticality, controlling the position of the unit with a building level.
Having fixed the lower part of the flue, mount the vertical section. Connect the straight sections in such a way that the upper shell fits onto the lower one, and the flue pipe, on the contrary, is inserted inside (condensate assembly).
Fasten the wall chimney duct at intervals of no more than 2.5 m. The brackets should not fall on the joints of the sections.
Lay the horizontal section of the sandwich up to the gas boiler and put on the adapter. Secure the chimney with clamps to building structures with a maximum spacing of 1.5 m.
Connect the heat generator to the chimney with a piece of single-wall stainless pipe.

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Reminder. In a 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:

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Make it yourself or order it

Order a chimney from professionals or do it yourself – it’s up to you.

Proper independent installation of a smoke exhaust system will definitely save the family budget. When installing, be sure to comply with all requirements of SNiP and fire regulations.

Despite the fact that the temperature of the exhaust gases is low, the harm from them is no less than from any other emissions. Therefore, special attention should be paid to the tightness of joints.

It is also mandatory to organize a condensate collection system.

Types and designs

There are several types of chimneys for gas boilers:

Brick (both as a separate system and with an internal liner made of stainless or galvanized pipe);
Single metal (made of galvanized or stainless steel sheet);
Made of sandwich elements (channels of two metal pipes inserted into one another, with insulation laid between them);
Coaxial (a pipe of a smaller diameter is inserted into a pipe of a larger one, without laying insulation);
Ceramic (made from special ceramic blocks);
Asbestos-cement.

All designs are schematically presented in the figures in the “Drawings and Schemes” section.

The chimney can be installed both indoors and outdoors.

Rice. 1. Design of attached and internal chimneys.

Where to place the chimney

How the process of installing a chimney for a gas boiler will take place largely depends on where this mechanism will be located. Therefore, the moment of choosing a place for it should be approached with special care.

A chimney for a residential building can be located in several places:

Outside the house.

The features of such installation will be as follows:

the entire length of the pipe must be equipped with thermal insulation;
the structure is always accessible for dismantling and any repair work;
no need to select different types of parts for the entire structure;
high safety score.

Inside a residential building.

This installation is distinguished by the following points:

It is necessary to insulate only that part of the chimney that is located outside the room, that is, on the street;
more complex installation and repair process;
potential risk of harmful substances generated during fuel combustion entering the house;
the need to purchase different types of parts for pipe installation.