Chimney for a gas boiler in a private house: basic installation requirements
The correct operation of gas heating equipment largely depends on the system that removes combustion products. Before you equip a chimney for a gas boiler in a private house, you need to have an idea about the types of equipment, the principles of its operation and the regulatory documents according to which it is installed. Regardless of who will carry out the work, the choice of the device and installation should be treated with full responsibility.
Types of chimney removal systems: which chimney to choose
The installation of a gorenje waste disposal system on a gas boiler contributes to the efficient functioning of the equipment and the entire heating system, safe and comfortable heating, as well as trouble-free operation of the boiler. Before you buy a chimney for a gas boiler, it would be useful to get expert advice on the existing options for flues and the feasibility of their use.
Types of flue channels to gas boilers:
- brick chimney — its construction is planned at the construction stage of the house and the foundation is arranged for it. A prerequisite is a smooth surface of the inner walls of the chimney. It should be noted that the structure must be resistant to the action of acid, which is formed due to steam condensation. Otherwise, there will be a rapid destruction of the brick chimney pipe. They are used in combination with ceramic or steel inserts. Brick chimneys for gas boilers are distinguished by a complex device, duration of construction and costly cost. In terms of technical indicators, they are in many respects inferior to the modern smoke removal systems that have appeared;
- stainless steel pipe construction — this version of the chimney has a high resistance to the action of the chemical environment and mechanical damage. The system is made in the form of a sandwich structure: when a pipe with a smaller diameter is inserted into the outer pipe. A fire—resistant material, basalt wool, is placed in the free space between them. Manufacturers offer a wide range of models of chimneys;
- coaxial chimney — the structure is assembled according to the principle of “pipe in a pipe”: Gorenje air is taken through one pipe, combustion products are removed through the other. Such a system has high technical characteristics that contribute to improving the safety of all gas equipment and increasing its efficiency. And due to the fact that the gorenje cycle takes place outdoors, the boiler with a coaxial chimney is an eco-friendly equipment.;
- a chimney made of ceramic pipes is a ceramic block with thermal insulation installed in a concrete frame. Such a smoke removal system is resistant to temperature fluctuations, waterproof, fireproof and has high mechanical strength. The main requirement for installation is high—quality joining of ceramic modules.
Which pipe for the chimney is better to use — everyone decides based on their specific situation. The main thing is to highlight the weaknesses and strengths of any option. Regardless of which type of chimney you prefer, its design and installation must comply with SNIP 2.04.05-91 “Heating, ventilation and air conditioning”. After studying these standards, you can learn how to properly install a chimney on a gas boiler.
Chimney for a gas boiler in a private house: basic requirements of SNiP 2.04.05-91
Measures for the installation of a chimney for a gas boiler, starting from the design stage and ending with the installation of the system itself, must comply with the requirements of the current regulatory framework, since improper installation and operation of gas equipment casts doubt on the safety of people using gas installations.
The main elements of the chimney design:
- flue — the channel coming out of the boiler into the chimney pipe is connected by an adapter;
- chimney pipes;
- revision — it is attached to the bottom of the chimney trunk and serves to clean the channel from gorenje products and remove excess moisture.;
- fasteners (brackets, clamps) — are used for mounting to the wall;
- other components for the system device.
As a rule, the location of the gas boiler in a private house is planned on the ground floor in a separate room (boiler room). All elements of the heating system must be connected to each other strictly hermetically. The basic rules for the installation of chimneys for gas boilers, regulating the technological procedure, are presented in the regulations of SNiP 2.04.05-91 and contain the following requirements:
- proper traction — ensures complete removal of exhaust gases;
- resistance to high temperatures;
- tightness of the docking places — all components along the entire length of the chimney system should fit snugly together;
- the pipe in the place of its passage through the overlap should be solid, without joints;
- condensate collector — the design of this element should ensure the collection and removal of liquid;
- if there are turns in the structure, revision hatches are arranged in these places to diagnose the condition of the chimney, clean it and drain condensate;
- the length of the pipe branch to the side should not exceed 1 m;
- it is possible that the permissible number of turns on the flue pipes is no more than 3;
- the height of the chimney pipe should exceed the height of the roof (at the highest point), so that good traction is provided and the reverse does not occur;
- the distance between the flue pipes and the surface, which is made of non—combustible materials, can be at least 5 cm, and if the surface material is combustible – at least 25 cm.
Useful advice! The complete tightness of the chimney sections will not allow the incandescent combustion products to go beyond the system.
The order of the chimney of a gas boiler in a private house
Depending on at what stage it is planned to install a chimney for a gas boiler, the drainage system can be internal or external (remote). In cottages under construction, where the use of gas boilers is provided, internal chimneys are used, the placement of which is taken into account by the project. In houses of old construction, when switching to heating by means of a gas boiler, the chimney is taken out.
You can compare the strengths and weaknesses of external and remote chimneys by reading the table:
|Type of chimney|
|Full thermal insulation of the chimney is required||Thermal insulation is necessary only in the area that goes outside|
|Safe operation is guaranteed in compliance with the standards||The possibility of penetration of combustion products into the room, high fire hazard is not excluded|
|The chimney device is made of the same type of elements and is characterized by simplicity of execution||It is characterized by complex installation, since there is a need for a large number of components and components of the chimney|
|Availability in carrying out any kind of repair work and maintenance||Difficulty in carrying out maintenance and repair of the chimney|
The installation of the chimney of an internal gas boiler is associated with the construction of a foundation and a protective channel made of brick. Then the safety of operation will be ensured. Such systems are more efficient and the formation of condensate in them is minimal. In some cases, chimneys can be attached to the wall of the house behind which the boiler is installed.
The device of a remote chimney requires high-quality fastening and mandatory maximum insulation, since condensate in such structures is formed in greater quantities.
The main stages of installing a chimney for an internal gas boiler:
- marking of places for the device of holes in the ceiling and roof of the house;
- the device of the opening under the chimney;
- connection of the boiler pipe to the flue;
- installation of revision, tee;
- extension of the chimney pipe;
- reinforcement of joints with clamps;
- fixing the structure with brackets;
- thermal insulation of the outer part.
Useful advice! The location of the chimney system should be strictly vertical, without narrowing or widening the channel.
Stainless steel flues for gas boilers
Steel flues can have a single-wall and double-wall construction. Single-layer exhaust pipes can be installed in heated rooms and used for lining brick chimneys. In three-layer systems, there is a thermal insulation layer between two pipes, which makes it possible to use them for both indoor and outdoor installation.
Due to the fact that sulfur impurities are contained in the gas fuel, when removing waste products, its vapors have an aggressive effect, corroding the walls of the flue ducts. Therefore, in the production of stainless steel chimneys for gas boilers, heat-resistant and acid-resistant AISI 316L material is used. Its use greatly increases the service life of smoke removal systems.
Of the weaknesses of the stainless chimney pipe for a gas boiler, it is possible to note not quite an aesthetic appearance. The advantages include:
- resistance to corrosion and aggressive chemical composition;
- light weight, no need for a base device;
- incombustibility of the material — stainless steel does not melt even at a temperature of 500 ° C.;
- the modularity of the design — the factory production of a large number of tees, adapters and knees allows you to build a chimney into any house;
- the factory release of all elements of the steel chimney allows you to assemble and remove it at any convenient angle;
- absolutely smooth round inner surface — provides a minimum of obstacles to the removal of combustion products;
- possibility of installation in an already built house;
- quite an affordable price of a chimney for a gas boiler.
When installing an external chimney made of steel, there is a high probability of dew point formation: if the temperature outside is low, the vapors discharged form condensate and a water plug is created. It clogs the channel, preventing the products from leaving, and thereby blocks the gorenje process. This can be avoided if you place the pipe in the laid-out channel of the chimney made of masonry bricks. This technique will also solve the aesthetic side of the structure.
Another option to avoid the formation of a water plug is to use a sandwich construction of two pipes, one of which is protected by a layer of basalt wool. Such a remote chimney system no longer needs additional insulation. The diameter of the chimney for a gas boiler is selected in such a way that it coincides with the section of the outlet of the equipment.
Useful advice! Stainless steel chimneys are easy to maintain, but once every 3 years it is necessary that the system is examined by a specialist.
Rules for installing a chimney for a gas column
The key to the safe operation of the gas water heater is the correct exhaust system. Chimneys are used for the column, which remove combustion products into the flue duct or directly into the atmosphere. The following types of pipes are used to remove exhaust gases:
- corrugated pipe — easy to install, the flexibility of the material allows
pull it up to 2-3 m in length, as well as lengthen it by connecting several segments of the corrugation;
- aluminum pipe — easy to install, resistant to condensation, needs additional thermal insulation;
- coaxial chimneys — the price of such systems can be reduced due to the possibility of pipe output through the wall. This reduces material consumption and installation costs. The main advantage of such a chimney is that the air from the room does not participate in the operation of all equipment.
Basic requirements for the installation of flue pipes for gas columns:
- the operation of the devices is prohibited without a chimney securely fixed in it;
- the draft inside the chimney system must be constant;
- the pipe material must be non-flammable, resistant to corrosion, condensation and high temperatures;
- the outer section of the chimney should have a vertical arrangement;
- the structure must be sealed to avoid carbon monoxide entering the room.;
- the exhaust pipe should be mounted in an open place for quick troubleshooting, if necessary;
- the flue pipe should be located at least 0.5 m above the roof level.;
- it is strictly forbidden to use ventilation systems, the space between floors, attics for the removal of gorenje products.
How to check the draft in the chimney of a gas boiler
Draft is one of the main indicators of the proper functioning of the chimney. Its effectiveness depends on the following parameters:
- section of the flue pipe — heated gases are removed faster with a smaller section, however, if it is too small, there is a threat of penetration of combustion products into the room. If the cross-section of the chimney is unreasonably large, a reverse draft effect may be created;
- accumulation of a large amount of soot on the walls of the trunk — due to this, the working section decreases, which leads to a decrease in the rate of carbon monoxide withdrawal;
- a large number of turns in the system — any of the turns of the pipe slows down the movement of exhaust gases;
- insufficient tightness of the chimney — the presence of small cracks, gaps contributes to the penetration of cold air into the system, which prevents the rapid removal of smoke;
- weather — high humidity and low atmospheric pressure can cause a decrease in traction.
There are several methods to check the traction condition. If the diagnosis is carried out by professionals, they use an anemometer — a device for measuring the speed of movement of gases. In everyday life , they use so-called folk methods:
- visual inspection — if there is smoke in the room, then there is a reverse thrust;
- with the help of a thin sheet of paper — it is brought to the viewing window: the stronger the paper is attracted, the better the traction;
- candle flame — a lit candle is brought to the channel and the flame is blown out. The direction of the smoke from the extinguished candle towards the chimney indicates a good draft.
Important! The thrust in gas boilers should be checked when the equipment is switched off.
Depending on the reason for which there is a weak craving, measures are taken to improve it. Cleaning of the channel from soot is carried out with the help of a special device consisting of a ruff, a sinker and a rope. The device is lowered into the channel and cleaned with translational movements along its entire length. In order to achieve complete sealing of the brick chimney, it is necessary to eliminate all cracks formed as a result of the destruction of the masonry.
Coaxial chimney for gas boiler: installation rules, advantages, installation
The main advantage of installing a coaxial chimney for a gas boiler is that such a chimney not only takes the exhaust gases out, but also provides the combustion chamber with air from the street. Thanks to this, the room does not need additional ventilation, and the air in the house remains able to maintain the health and efficiency of the people there. The equipment with such a discharge of gorenje products is called a gas boiler without a chimney.
Coaxial chimney design
The basis of the design of the coaxial chimney consists of two pipes of different diameters, one of which is located inside the other. The inner pipe is designed for the output of waste substances to the outside. Through the outer pipe, or rather, through the space between the inner and outer pipe, air is taken from the outside, which is used for gorenje gas. Thus, the chimney copes with several functions at once:
- increasing the safety of the chimney — the incoming air from the street heats up, and the outgoing combustion products cool down.gorenje;
- increased boiler performance — the efficiency of the equipment increases due to the fact that the air enters the combustion chamber already heated;
- maximum combustion of gas — due to the fact that the efficiency of the boiler increases, complete combustion of fuel is achieved;
- environmental friendliness of the heating system — the entire working cycle of the gas equipment takes place outside, which ensures comfort and safety of heating.
Round pipes are used for the manufacture of the chimney: the outer pipe with a diameter of 100 mm is made of steel with a thickness of 1-2 mm, the inner one is made of aluminum alloy. The diameter of the latter is 60 mm. Pipes with such a ratio of diameters are used in coaxial chimneys for wall-mounted gas boilers and floor devices with a closed combustion chamber. To avoid the pipes coming into contact with each other, jumpers are installed along their entire length.
According to the installation method, coaxial type chimneys can be horizontal and vertical. The horizontal option is more popular due to the simple installation. In the case when it is technically impossible to mount the system horizontally or the distance from the boiler to the outer wall exceeds 4 m, they resort to installing a vertical coaxial chimney. It is worth noting that its installation is more complicated.
Advantages of coaxial smoke removal systems
Coaxial chimneys are used for various gas equipment in which the combustion chamber has a closed structure. These are floor-mounted and wall-mounted gas boilers, gas flow heaters (columns), convectors and other devices.
It is worth noting the main advantages of using coaxial chimneys over other types of exhaust systems:
- natural heat exchange — heating of the incoming air and cooling of the outgoing gases occurs due to the construction of the pipe, which, in turn, does not allow the wall to get very hot;
- increasing the productivity of the gas equipment itself;
- compactness — the chimney is neatly mounted and does not take up much space, which allows it to be used not only in private cottages, but also in apartments of high-rise buildings;
- safety of operation — there is no lack of oxygen in the air of the room where the boiler is installed, since contact of the air from the room with the excreted substances is completely excluded;
- ease of installation — reduces the cost of installing a coaxial chimney.
Useful advice! If you have purchased a wall-mounted gas boiler for autonomous heating of an apartment, using a coaxial chimney for it is the safest, since the combustion products are removed not into the ventilation channel, but directly into the atmosphere.Gorenje
Requirements for the installation of a coaxial chimney
As with any gas equipment, the installation of coaxial chimneys is subject to specific requirements of SNiP 2.04.05–91, section 3 “Heating”; 2.04.08–87, as well as regulations regulated by the “Safety Rules in the gas industry”. They can be different depending on the installation method of the coaxial chimney: horizontal or vertical.
For any type of installation, there is a general requirement for the maximum length of a coaxial chimney for a gas boiler: it cannot exceed 4 m. When it is required to conduct a smoke removal system at a considerable distance, special coaxial models with dimensional standards are used.
When passing a vertical coaxial chimney for a gas boiler through the ceiling and roof, an adapter is used, the design of which is provided by the manufacturer specifically for this system. This also applies to coaxial chimney extensions when it is necessary to install a system of the required length. Tightness in the places where pipes pass through the overlap is provided by a special terminal head. It also prevents precipitation from entering the system.
The horizontal method of installing a coaxial chimney is used, as a rule, for wall-mounted gas equipment. To avoid condensation, it is necessary to withstand the slope of the chimney down from the boiler, ranging from 3 to 5%. There are norms for the location of smoke ducts for the chimney in the outer wall. So, if the hole is supposed to be in the wall next to the window, the distance to the window should not be less than 0.5 m, if above the window — at least 0.25 m.
Many manufacturers of gas equipment include a pipe for the removal of combustion products in the supply. If you bought a coaxial chimney for a gas boiler together with the equipment, it is necessary to check the presence of a horizontal part of the pipe (usually about 1 m long), a branch, a terminal (head), a set of sealing gaskets, a membrane. If, when installing a pipe through a wall, it is necessary to bypass any protrusions or fittings, use elbows and bends.
Useful advice! It is necessary to provide protection for all terminals and inputs on the coaxial chimney from foreign objects.
Coaxial chimney for a gas boiler in a private house: how to make with your own hands
Before installing a coaxial chimney with your own hands, you need to familiarize yourself with the manual for the device and operation of the purchased gas equipment. Due to the specific design of the coaxial pipe, the installation of a chimney for a wall-mounted gas boiler should be carried out extremely carefully. It is necessary to avoid the formation of dents on the pipes or other damage that leads to depressurization of the system.
To perform the installation work, the following system elements will be needed:
- pipe with flange;
- crimping clamps;
- coaxial knee;
- adapter for connection to the boiler;
- extension cable with sealing cuffs (if required);
- decorative overlays.
According to the requirements for the installation of the chimney, a hole of the required diameter is arranged in the outer wall. If there is a window opening in the wall, it is necessary to place the hole at a distance no closer than 0.5 m from the window. When connecting the chimney to the gas boiler, the adapter is first connected, and then all the links assembled into a single structure.
The pipe is taken out through a hole in the wall, observing the slope from the boiler. If it is necessary to bring the chimney to the wall, the structure is fixed with clamps. The gaps between the wall hole and the inserted pipe are blown out with foam or sealed with mineral wool. After that, they close these places with decorative rings.
The device of a brick chimney with your own hands
The construction of a brick chimney is exclusively a vertical channel with a square or rectangular cross-section. For laying a brick chimney, a full-bodied ceramic brick is used, which is laid on a mortar. The outer section of the channel is laid out with an ordinary brick corresponding to the style of house construction, which can be seen in numerous photos of brick chimneys. If the house is lined with stone or plastered, you can arrange the chimney in the same way.
Brick chimneys for gas boilers: installation requirements
Before laying out a chimney for a brick boiler, it is necessary to build a foundation, the height of which should be at least 0.3 m. The dimensions of the base along the perimeter should protrude beyond the contour of the channel itself by at least 0.15 m. If the chimney is located in a part of the outer wall, its foundation should be flush with its base. The laying of a brick chimney with their own hands (video instructions confirm this) begins at the construction stage of the walls of the house.
Requirements for brick chimneys:
- the smoke channel should be vertical, without ledges, narrowed and expanded sections;
- the thickness of the masonry of the brick pipe for the chimney is taken taking into account the exclusion of freezing;
- the minimum permissible cross—section of the flue ducts is 14 x 14 cm, which corresponds to the size of half a brick, taking into account the seam;
- the size of a brick chimney, whose height is less than 5 m, should be increased to a channel section of 14 x 20 cm;
- the construction of the chimney is carried out in the walls between the heated rooms, which will prevent its cooling and reduce draft;
- tightness — masonry of a brick chimney is carried out with a dressing so that the vertical seam of the previous row is overlapped by the brick of the next;
- the inner surface of the channel should be smooth;
Useful advice! To achieve a smooth and smooth inner surface of the channel, when constructing a brick chimney with your own hands, use special templates.
- the distance between adjacent flue ducts should not be less than 5 average external pipe diameters;
- if ventilation ducts are located next to the chimney, their height should be equal to the height of the chimneys.
To reduce construction costs, it is necessary to arrange as many channels as possible in the common chimney. In this case, the flue and ventilation ducts placed next to each other will heat each other, which will generally improve the functioning of the chimney.
Preparation of mortar for laying a chimney made of brick
The composition of the mortar for laying a brick chimney is selected taking into account which part of the pipe is laid out: external or internal. For the construction of the external channel, the same mortar is used as for laying the load-bearing walls of the house building. It is prepared from cement, sand, water and can harden in air and in water. The mixture is prepared in such a volume that it is worked out within an hour, as it sets quickly.
In order for the mixture not to collapse under the influence of an aggressive environment, it is recommended to add special additives to it that increase its plasticity, strength and acid resistance. Thanks to these additives, it is possible to improve the quality of the masonry itself, increase the speed of construction and the durability of the work performed.
The preparation of a solution for a brick chimney passing inside the house is based on the use of refractory clay and chamotte in its composition in a ratio of 1: 1. Such mixtures perfectly cope with the action of high temperatures, they are durable and do not emit harmful substances. To give the clay mixture strength, you can add table salt to its composition (about 120-150 g per bucket).
Useful advice! The strength of the mortar for laying the chimney can be enhanced by adding Portland cement in the proportion of 1 kg per bucket.
By laying a brick chimney with your own hands, you can purchase ready-made mixtures that are characterized by heat resistance and acid resistance. Preparing the solution yourself can reduce the cost of constructing a chimney.
It is quite possible to build a brick chimney with your own hands — the video below will help you get acquainted in detail with the stages of construction of the structure, taking into account all the basic requirements.
The feasibility of using a brick chimney for a gas boiler
Considering the advantages and disadvantages of brick chimneys, it is possible to draw conclusions regarding their use in combination with gas boilers. Their advantages include:
- the probability of using an existing flue duct, which reduces the cost of the chimney;
- possibility of operation in conjunction with gas equipment having an open combustion chamber;
- reasonable cost of materials for the construction and finishing of the structure.
The durability of brick channels is observed only when using them for fireplaces or stoves. If they are used for gas boilers, due to the low temperature of gorenje products, condensate will form on the channel walls, and harsh operating conditions in an aggressive environment will lead to the gradual destruction of brickwork and deterioration of performance.
In addition, the requirements for such chimneys are more stringent:
- impeccable masonry — if the skills are not enough, it will be necessary to invite a qualified mason to work, which will cost a round sum. Prices for work: masonry of a chimney made of rough bricks from 6000 rubles for 1 m3, facing masonry — 2500 rubles for 1 m2;
- inability to perform a complex channel configuration (if you need to bypass, for example, a beam in the ceiling);
- the use of the old channel should be carried out with the use of sleeve;
- the need for thermal insulation.
The disadvantages of such a system include a decrease in traction during the heating of the brick. Thus, the correct chimney for a gas boiler will be a brick channel together with a steel or ceramic insert. The photo of brick chimneys shows that the liners are equipped during the laying of the channel. At the same time, it is necessary to leave a gap between the liner pipe and the brick surface. This is necessary so that the pipe can move inside the channel.
Flues for gas boilers: prices for various types of pipes
When planning your budget when purchasing flue pipes, you should take into account the length and diameter of the channel, the presence and number of turns, as well as the material from which the pipes are made. There are no fundamental differences in the design and cost of chimneys for outdoor gas boilers and wall-mounted appliances. A stainless steel chimney will cost more than a brick chimney, but a steel pipe is easier to install, which makes the cost of its installation quite affordable.
You can buy a chimney for a gas boiler at specialized points of sale and in online stores that sell these products. A large range of fittings, fittings, tees, adapters, plugs and other necessary design details are also offered for sale. Given the convenient sorting of products by categories and models, you can quickly find and order the right product.
The cost of 1 m of single-circuit stainless steel pipe with diameters of 100, 110, 115, 120 mm is 650 rubles, the same pipe with a diameter of 140-150 mm will cost 750 rubles. The price of a knee with a 90° rotation angle made of stainless steel for a pipe with a diameter of 110-120 mm is 550 rubles. with a metal thickness of 0.6 mm. You can buy 1 m of stainless steel sandwich pipes with a diameter of 140-230 mm for 1900 rubles.
Useful advice! You can save money on purchasing high-quality and durable pipes for chimneys if you place an order during the discount period.
The price of a coaxial chimney for a gas boiler with a diameter of 60-100 mm and a length of 1 m, sold in a horizontal set, is 3500 rubles. The purchase of a coaxial chimney Baxi — a global manufacturer of modern heating systems — will cost 4,200 rubles. The complete set of the chimney for a wall-mounted gas boiler includes a 75 cm long pipe with a diameter of 60-100 mm, a 90° outlet and a tip. All products are guaranteed.
Competent installation of any household appliances is the key to its safe and long—term operation. Especially when it comes to gas equipment. The installation of a combustion product discharge system for gas boilers requires preliminary engineering calculations and qualified implementation.