Not a single private house can do without a chimney channel, in which there is a boiler or gas equipment. Technically, measures to organize a system for the removal of combustion products may seem too troublesome and costly, but modern technologies have optimized the processes for arranging furnaces and boilers. Instead of traditional masonry, you can use a galvanized pipe of the desired diameter to equip the chimney. It is easy to mount and does not require much maintenance during operation.
Varieties of metal structures of the chimney
Based on galvanized steel, three types of pipes are produced - simple single-circuit, double-circuit (sandwich pipes) and coaxial. In the first case, single-sheet steel is used without an insulating substrate. These are small diameter structures.which are suitable for various types of heating equipment - an almost universal solution, but with high heat losses and a low degree of strength. Is it possible to use a galvanized pipe with one circuit for the chimney when it comes to a high-power boiler? Theoretically, this is possible, but due to the low bandwidth, the chances of smoke increase.
Sandwich pipes compare favorably with the presence of an internal insulation and a large diameter, which expands the range of their applications. At the same time, dual-circuit models are more expensive and have their own operational risks, as will be discussed below.
As for coaxial chimneys, their designs are just focused on supporting high throughput by increasing the diameter, but without including an insulating layer. It is advisable to use such pipes in rooms with impaired air circulation or with an absent forced ventilation system.
Basic selection parameters
When planning the purchase of a chimney, you should also focus on the following selection criteria:
- Sizes. The standard is 120 mm galvanized pipe. A chimney of this size serves most country houses and cottages, but it is still recommended to calculate the parameters based on the power of the heating equipment.
- Type of heating system. There are special models of pipes for stoves, boilers and fireplaces, and in different configurations. Often the differences between different proposals are not expressedspecific characteristics of the design, but a complete set and additional functional elements.
- Location configuration. The structure of the roof of the house and the type of roofing also impose their own requirements on the individual parameters of the choice of pipe - both in length and thickness, and in the type of insulating materials.
Calculate the diameter of the pipe for the chimney
If the height is selected individually for the general characteristics of the house, taking into account the parameters of the attic space and the angle of the slopes, then the diameter of the pipe will depend on the heating unit. The volumes of produced cinders depend on the performance of boilers and furnaces - accordingly, the design of the outlet channel is also selected for the power potential. So, for units with a power of up to 3500 W, it is desirable to install structures with a thickness of 80-100 mm. The size increases as it approaches 5200 watts. For such boilers, standard 120 mm galvanized pipes are recommended. Chimneys with a large diameter should also be calculated taking into account the presence of auxiliary layers - both insulation and reinforcement.
120mm to 150mm thick structures feature thick walls and dual circuit configuration. That is, a technological insulator layer is also provided, which will not affect the throughput in any way. For example, in a 150 mm galvanized chimney pipe, the insulation can take 15-20 mm. However, it is worth talking about heat-insulating materials separately.
The nuances of using thermal insulation in the chimney
Insulation layer is used only in double-circuit sandwich pipes. It should be noted right away that the presence of an insulator practically does not affect the mass, but it increases the rigidity of the barrel. But another question arises regarding the use of a heat-insulated galvanized pipe for a chimney - can it be used taking into account fire safety requirements? Such restrictions are justified, since the fires of the insulation due to contact with hot steel and outgoing gases often occur in combinations of potbelly stove-sandwich-pipe. But this applies to cases of violations of the rules for the operation of the chimney and, in principle, the use of low-quality materials.
The main rule for those who want to insure against such threats is to select a pipe with a heater designed for the temperature of the exhaust gases. For example, the normative regime reaches 180-200°C, and the insulation based on crushed vermiculite withstands from -250 to 1150°C. But more often they use more familiar mineral and synthetic materials, bas alt or ceramic wool. In this case, we can talk about a critical temperature of 600°C.
Possible pipe installation patterns
Before proceeding with the preparatory and installation operations, you should at least roughly sketch out a work plan defining the pipe installation configuration. Installation can be carried out according to two principles - “by smoke” and “by condensate”. What does it mean? In the first version, the system will provide for the presence of outlet channels with tees for condensate drainage. In the second schemetechnological branches for condensate are not needed due to its natural absence.
The choice of one of these configurations is important due to the fact that the design must be protected from excess moisture, harmful to both the insulator and the metal. By the way, a chimney pipe made of galvanized steel is the most protected from interaction with moisture, but protective coatings are not enough to completely protect the structure. Ventilation circuits must in any case be present in the areas where the pipe passes. Therefore, the optimal solution would be a combination of segments with condensate outlets and continuous smoke outlets. It is also not worth abusing tees and other technological waste channels, as they reduce the efficiency of the chimney as such.
Preparation for installation work
First of all, the conditions for the organization of the channel are being prepared. A place must be prepared not only for the passage of the pipe, but also for its fastening with the arrangement of technological branches. Particular attention is paid to the attic floor and roofing. Holes of a suitable diameter are formed in them and, if necessary, support connections are installed for rigid fixation of the trunk. Along the edges of the created holes, an insulating coating is installed. It is necessary to provide pads to hold and insulate the galvanized pipe. For the chimney in the attic, rafter fixation elements are also mounted. This is especially true for double-circuit structures of large diameter. With side restraintspoints, you can grab the structure with clamps with soft pads. The means of sealing the joints in the places where the pipe passes are also thought out in advance. To do this, you can provide flange linings or liquid silicone sealing.
Assembly activities
During the installation process, the assembly is carried out from the bottom point from the pipe of the heating equipment upwards. Pipe extension is performed in segments by attaching each subsequent section to the previous one. Double-walled shafts can be built up by integrating one nozzle segment into another. Further, with the help of locking fasteners, the mounting assembly is simply clamped according to the clamp principle. In the case of installing a galvanized sandwich pipe for the chimney, the walls of the passage between the ceilings must be filled in advance with non-combustible heat-resistant material. This operation will also increase the fire safety of the structure. Do not forget about the fastening of technological elements, among which there may be elbows, tees, condensate collectors, etc. Additional fittings are usually fixed with complete hardware, brackets and clamps of a suitable format. Moreover, regardless of the type of butt joint, it is desirable that the support fasteners be present on every 200 cm of the pipe.
Organization of the exit of the chimney pipe
A very important stage of installation falls on the arrangement of the output part of the structure. To bring the pipe out, special equipment is used, which is placed around the roof opening and attached to the coating, grabbing the pipe. By this time within the attic, the main part of the chimney must be fixed with a rigid support in the form of a so-called metal cup. The final segment of the structure will depart from it through a hole in the roof. At the final stage, the arrangement of the outer part of the pipe is carried out. At a minimum, a cap or umbrella should be installed on the galvanized chimney pipe in order to protect the duct from precipitation and debris. It can also be made independently from sheet metal by welding to the nozzle.
Positive feedback about galvanized chimneys
The metal chimney is in high demand among private homeowners due to its functionality, ergonomics and ease of installation work. At least, these advantages are visible against the background of the use of classic brickwork. Moreover, often metal pipes are also used to modernize existing structures made of other materials. For example, it is possible to extend an asbestos chimney with a galvanized pipe using special couplings and rubber rings. Another thing is that reviews of combined systems are no longer so positive due to a decrease in the strength of the chimney.
You can compensate for the lack of rigidity with metal ties or a reinforcing belt at the junction, but such inclusions will add loads to the roof and rafter structure, which is also not always acceptable.
Negative reviews about galvanized chimneys
The main disadvantages of metal pipes used in the design of the chimney are associated with lowstructural reliability and the need for additional protection. Users of such structures in cold regions note the negative impact of cold bridges, which have to be sealed regularly, since the galvanized chimney pipe loosens under the influence of winds. Reliable fastenings do not always help in such cases due to the lack of strong structural supports to keep the pipe in a stable position at a height of 100-150 cm above the roof.
Conclusion
The fashion for the use of modular chimneys fully fits into the principles of the modern organization of private home communications. In the standard version, a galvanized chimney pipe takes up little space, allows you to assemble structures of varying degrees of complexity, and at the same time regularly performs its basic tasks. But along with the individual nuances of maintenance in operation, one should also prepare for serious expenses for the purchase of the main elements of the pipe. The cost is about 2-3 thousand rubles. for one segment, and there may be more than a dozen.
