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 such a design do not have a specific smell, however, they instantly poison the human body when they enter it. In this regard, special attention is paid to the chimney channels, from the assembly stage to installation.
Requirements for commissioning
Chimneys for a 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.
Because the outlet gas temperature is about 150 degrees, for the pipesuitable for almost any building material. The optimal design will be a sandwich element with bas alt insulation, which makes it possible to reduce the accumulation of furnace gases. When operating the boiler, it is imperative to equip exhaust ventilation with a diameter of at least 100 mm. It is also necessary to develop and approve the project for the creation of heating and ventilation. As an option, choose a double-circuit pipe made of stainless steel, resistant to chemically active substances. External analog can be made from galvanized sheet.
Features
The ventilation duct from the boiler room is mounted simultaneously with the chimney. You can use plastic pipes for it. Upon completion of the installation of the "smoker" and the ventilation system, it is necessary to obtain a commissioning certificate from the VDPO (All-Union Voluntary Fire Society).
What to consider when choosing?
When choosing a chimney for a gas boiler, as well as the main unit itself, it is necessary to take into account the actual conditions of its installation:
- The power of the unit as a first approximation should be at least 1 kW per 10 m2 area.
- If you plan to use a DHW fixture, you will need to install two-circuit models with a direct or indirect water heater. Analysis of hot water points can be connected to the main single-circuit line.
- All wall modifications are volatile, as they operate from the mains. In the event of a power outage, the consumerremains without heating.
- The floor gas boiler is autonomous, all adjustments are made mechanically.
- The safest variations include units with closed fireboxes and coaxial versions.
Device
The classic chimney design for a gas boiler consists of the following parts:
- Connecting link between the main unit and the pipe (gas duct).
- Components for forming an exhaust duct (adapters, bends, tees, clamps).
- Exterior and interior fixing brackets.
- Inspection hatch for cleaning the device from soot.
- Condensate collector with drain.
- A rotary or slide type damper for draft adjustment.
- Deflector. Protects the pipe from clogging and drafts, enhances draft.
Chimneys of gas boilers in a private brick house
Laying such a device is a rather painstaking and complex process that requires certain 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 outside of the pipe is exposed to weathering.
The situation can be corrected by installing an insert from a pipe with a round cross section inside the brick duct. It can be made of plastic, asbestos, ceramics. This design is called "sleeving". It should be additionally insulated above the roof from the outside.
Coaxial chimney for gas boiler
These devices in wide use appeared not so long ago. The design is operated only with closed types of devices. Air does not enter this apparatus from the boiler room, but is sucked in from the outside. According to the texture, the product is a double-walled version with insulation in the form of longitudinal partitions.
After the combustion of the gas, cold air is forced out, which passes through the inner tube, 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 draft, since in closed counterparts it is forced by a rotating internal fan.
Metal modifications
The chimney for a gas boiler in a private house in the most popular design is made of metal pipes. The material allows you to set several configurations. Among them:
- External samples mounted along the wall of a building.
- Internal options, equipped in parts of the roof and floors.
- Coaxial models for closed units.
Installation of a gas boiler chimney 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 interior equipment is made of singlepipes, which allows you to keep warm in the room. The design uses tees and taps for draining condensate. The vertical part of the chimney is insulated with bas alt wool or similar material, on top of which protection is mounted in the form of a foil or galvanized jacket.
Arrangement of chimneys with your own hands
Brick options are mounted in the following order:
- The whole structure is installed on a separate fundamental basis, a window is made in the lower part for revision and cleaning.
- Masonry is performed with standard solid bricks using a fire-resistant mortar. Alternatively, you can use a clay-sand composition designed for kiln work.
- Installation of chimneys for gas boilers is made from ordinary red refractory bricks.
- At the calculated height, a window for entering the pipe and a nest for the flue are left.
Recommendations
At the stage of masonry overlapping, fluffing is performed, the chimney pipe of gas boilers is set with a minimum expansion - one to two. The opening in the interceiling space is sealed with bas alt wool or asbestos sheet. Further construction of the structure is carried out with the initial order.
At the point of passage through the overlap in the masonry, one more 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 (“otter”) is organized. It represents the gaps between the roof and"smoke", which are filled with insulation and a sheet of the corresponding profile. Alternatively, bituminous sealant is used for sealing.
Mounting other options
Chimneys made of asbestos and ceramics are mounted similarly to metal structures. The installation features of these devices include the need for a 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 speed of movement of the furnace gases decrease with a decrease in thrust. These problems, coupled with the possibility of a reverse emission, are fraught with the flow of carbon monoxide into the room, which can lead to tragic consequences. Sufficient blowing will be provided by a well-heated pipe, guaranteeing high heat transfer and fuel combustion activity. As a result, the efficiency of the thermal 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. Installation of such a device requires an individual approach. Removal of waste masses is carried out through a horizontal or vertical outlet using a single-walled pipe. The sandwich element is formed before the transition of the floor, it is strictly forbidden to equip the joint in this place.
Stages of work:
- cut out part of the overlapat a distance of 130-150 mm from the pipe;
- a 1.5 mm thick steel sheet is mounted at the bottom, fixed to the base with screws;
- a similar element is fixed on the ceiling, connected to a box for laying loose insulation;
- bas alt wool is placed in the ceiling;
- at the top of the free niches are also filled with insulation;
- on top of cotton wool and bas alt, another metal sheet is mounted.
The connection with the roof is made according to an identical principle, standard shelter parts are put on metal pipes, which can have different angles of inclination, a universal or adjustable plastic base.
Helpful tips
Installing a gas boiler chimney for a private house, together with the connection, is a very important undertaking, on which the he alth and safety of residents, as well as heating efficiency, 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 galvanized brick or aluminum with asbestos. Work can be carried out only if careful measurements are made, a capital project is created and approved. The length of the chimney must be at least five meters from the bottom of the firebox to the top tier. By following all the recommendations and rules, you will receivean excellent system that will heat your home with high quality and safety for many years.
