An important detail in the arrangement of heating a cottage or a private house is a chimney for a gas boiler. It must comply with safety requirements, since the exhaust gases in this design do not have a specific odor, but immediately poison the human body if it enters it. In this regard, special attention is paid to the chimney channels, starting from the assembly stage, ending with installation.
Commissioning Requirements
The chimneys for the gas boiler must comply with the standards SNiP 2.04.05-91 and DBN V-2.5.20-2001. When designing heating, it is necessary to take into account the requirements of these documents, strictly observe them at all stages of work. The final scheme should be agreed with the gas service without fail.
Since the temperature of the exhaust gases is about 150 degrees, almost any building material is suitable for the pipe. An optimal design will be a sandwich element with basalt insulation, which makes it possible to reduce the accumulation of furnace gases. When using the boiler, it is absolutely necessary to equip exhaust ventilation with a diameter of at least 100 mm. You should also carry out the development and approval of the project for the creation of heating and ventilation. Alternatively, choose a double-circuit pipe made of stainless steel, resistant to chemically active substances. External analogue can be made of galvanized sheet.
Features
The ventilation duct from the boiler room is mounted simultaneously with the chimney. For it, you can use plastic pipes. Upon completion of the installation of the “smoker” and the ventilation system, it is necessary to obtain the commissioning certificate at VDPO (All-Union Volunteer Fire Society).
What to consider when choosing?
When choosing a chimney for a gas boiler, as well as the main unit, it is necessary to take into account the real conditions of its installation:
- The power of the unit in the first approximation should be at least 1 kW per 10 m2 of area.
- If you plan to use the device for domestic hot water, you will need to install dual-circuit models with a water heater of direct or indirect action. Analysis of hot water points can be connected to the main single-circuit line.
- All wall-mounted modifications are volatile, since they operate from an electrical network. In case of power outages, the consumer is left without heating.
- The floor gas boiler is autonomous, all adjustments are performed mechanically.
- The safest variations are units with closed furnaces and coaxial versions.
Device
The classic chimney design for a gas boiler consists of the following parts:
- Docking link between the main unit and the pipe (gas duct).
- Components for forming the exhaust duct (adapters, elbows, tees, clamps).
- Mounting brackets on the outside and inside.
- Revision hatch for cleaning the device from soot.
- Condensate collector with drain.
- Rotary or slide gate for adjusting thrust.
- Deflector. Protects the pipe from clogging and drafts, enhances traction.
Chimneys of gas boilers in a private house made of brick
The laying of such a device is a rather painstaking and complex process that requires some experience and knowledge. As a result, a rectangular or square channel is formed. The disadvantage of this design is the problematic movement of exhaust gases. They move in a spiral, forming stagnant compartments with soot and condensate in hard-to-reach places. In addition, the outer part of the pipe is subject to destruction from atmospheric exposure.
The situation can be corrected by installing a liner from a pipe with a circular cross-section inside a brick duct. It can be made of plastic, asbestos, ceramics. This design is called "sleeve". It should be additionally insulated over the roof from the outside.
Coaxial chimney for gas boiler
These devices in wide use have appeared not so long ago. The design is operated only with closed types of devices. Air does not enter this boiler from the boiler room, but is sucked in from the outside. The texture of the product is a double-walled version with a heater in the form of longitudinal partitions.
After gas combustion, cold air is displaced, which passes through the inner pipe, being sucked in by the outer element of the coaxial device. The specified model is displayed on the street through the wall. This is necessary to create natural traction, since in closed analogues it is formed by force with the help of a rotating internal fan.
Metal modifications
The chimney for a gas boiler in a private house in the most popular version is made of metal pipes. The material allows you to set several configurations. Among them:
- External samples mounted along the wall of the building.
- Internal options, equipped in parts of the roof and floors.
- Coaxial models for enclosed units.
Installation of the chimney of a gas boiler requires making a special hole at an angle of 90 or 45 degrees, after which the pipe is brought out. In the horizontal plane, the length of the device should not exceed one meter. The internal equipment is made of a single pipe, which allows you to save heat in the room. The design uses tees and valves to drain the condensate. The vertical part of the chimney is insulated with basalt wool or similar material, on top of which a protection is mounted in the form of a foil or galvanized shirt.
DIY chimney installation
Brick options are mounted in the following order:
- The whole structure is installed on a separate fundamental basis, a window for inspection and cleaning is made in the lower part.
- The masonry is performed with a standard solid brick using a fire-resistant mortar. Alternatively, you can use clay composition designed for furnace work.
- Installation of chimneys for gas boilers is made of ordinary red refractory brick.
- At the calculated height, a window for entering the pipe and a nest for the gas duct are left.
Recommendations
At the stage of overlap with masonry, a fluffing is performed, the chimney of gas boilers is exposed with a minimum broadening - one to two. An opening in the inter-ceiling space is covered with basalt wool or asbestos sheet. Further construction is carried out with the initial order.
At the point of passage through the ceiling in the masonry, another fluff is made, without changing the diameter of the inner channel. At this stage, you should carefully consider the passage of the roofing panel. Here another element is organized (otter). It represents the gaps between the roof and the "smoke", which are filled with insulation and a sheet of the corresponding profile. Alternatively, bitumen sealant is used to seal.
Installation of other options
Chimneys made of asbestos and ceramics are mounted similarly to metal structures. The features of the installation of these devices include the need for strictly vertical placement of the working channel and the presence of a separate foundation.
It is worth noting that the main losses in the chimney pipe for a gas boiler occur under the influence of external cold air. In this case, the temperature and the rate of movement of the furnace gases decreases with a decrease in draft. These problems, coupled with the possibility of a return release, are fraught with the influx of carbon monoxide into the room, which can lead to tragic consequences. Adequate blowing will provide a well-heated pipe, guaranteeing high heat transfer and fuel combustion activity. As a result, the efficiency of the heat boiler increases, which is considered one of the most important parameters for gas units.
Internal models
Sometimes a chimney is carried out inside the rooms of a private house, with the intersection of one or more floors and roofs. The installation of such a device requires an individual approach. The exhaust mass is removed through a horizontal or vertical outlet using a single-walled pipe. A sandwich element is formed before the transition of the floor, the joint in this place is strictly prohibited to arrange.
Stages of work:
- cut part of the overlap at a distance of 130-150 mm from the pipe;
- in the lower part they mount a steel sheet 1.5 mm thick, fasten it to the base with screws;
- a similar element is fixed on the ceiling, connected to the box for laying loose insulation;
- basalt wool is placed in the ceiling;
- in the upper part, free niches are also filled with insulation;
- on top of cotton wool and basalt, another metal sheet is mounted.
The connection to the roof is done on an identical principle, standard shelter parts are put on metal pipes, which can have different angles of inclination, a universal or adjustable plastic base.
Useful Tips
The installation of the chimney of a gas boiler for a private house along with the connection is a very important event, on which the health and safety of residents, as well as the efficiency of heating, depend. It is better to entrust the installation work to specialists with relevant experience and permission to carry out such work.
When connecting independently, do not forget that connecting more than one gas unit by combining pipes in one chimney is unacceptable. It is also forbidden to aggregate galvanization with brick or aluminum with asbestos. Work can only be carried out if careful measurements are made, a capital project is created and approved. The chimney should be at least five meters in length from the lower point of the furnace to the upper tier. Observing all the recommendations and rules, you will get an excellent system that will heat your home efficiently and safely for many years.