It should be noted immediately that chimneys in this design are not used for all boilers, but only for those that have a closed-type combustion chamber. What is their feature? For the high-quality functioning of the boiler, the air, which ensures the normal flow of the combustion process, is taken not from the room in which the unit is located, but from the outside( from the street).
Such heating units should be located in residential buildings, especially if they are wall-mounted and installed, for example, in the kitchen.
What is a coaxial type chimney? In fact, it is a pipe, inside which another one is laid, only with a smaller section. Their walls are "isolated" from each other, since along the entire length there are special dividing elements - bridges. What does it give?
Features of the coaxial chimney
Versatility of the
This design allows solving 2 tasks at once - air intake( "external" pipe) and exhaust gas( "internal" channel).Therefore, there is no need to mount separately both mains - "feed" and "tap".This allows, first, to make a passage in the wall only in one place, and, secondly, to reduce the total number of pipes passing inside the room, which is especially important for small rooms. It is unlikely that the 2 "trails" will add to the attractiveness and comfort of working in a small kitchen, when on account virtually every "cm2" of useful space, not to mention the possible difficulties in planning the placement of "furniture" items and various household appliances. Coaxial chimney allows you to save a significant amount of space.
No air is drawn from the room
Therefore, oxygen is not burned and there is no need for frequent airing of the room. And if the house is located near a highway with heavy traffic( exhausts of cars), next to an industrial enterprise, whose pipes "chadyat" continuously, the advantage of a coaxial chimney is even more obvious. After all, the air that he takes from the street, comes not into the room, but into the chamber of the boiler.
The efficiency of the
heat generator is increased. The boiler does not spend additional energy on heating the cold "outside" air. Its temperature automatically rises when passing through the pipe, because along the adjacent street the hot, "spent" is displayed. Consequently, natural heat exchange occurs between the two streams. This allows you to get a large temperature in the heating system with a lower fuel consumption.
As a consequence, the gas in the chamber burns completely, and its "remains", as is the case with another version of the air supply system and the removal of combustion products, are not taken to the street. This fact makes it possible to consider coaxial chimneys as more environmentally friendly devices than analogs.
The amount of condensate
drastically decreases This particular factor often provokes the icing of the pipe at the point where it is taken out. In the case of a coaxial chimney, this is virtually impossible.
Easier installation and maintenance of
Naturally, installation and maintenance of one product is much easier. For example, fewer joints of elements, their fixation to the walls of the room. And in terms of cleaning( dust, dirt stains), a "single" design is preferable.
The installation of a chimney of this type allows not to engage in installation of pipes on the roof of the house, which greatly simplifies the task."Coaxial", as a rule, is displayed on the street through the wall of the building, and not through the roofing "pie".
Before considering the installation of a coaxial chimney, it is necessary to understand the requirements for its installation.
- The exhaust gas outlet through the walls is only used for power units up to 30 kW.
- Gas pressure at the "supply" - up to 0,003 MPa.
- Joints of the main components must not be "in the wall".
- The total length of the chimney - no more than 3 m, although in some cases it is possible to increase it using special "extensions".
- The exhaust gas pipe must not rise above the ridge span.
Mounting technique
Selecting the location of the route
When installing a water heating system, the main requirements are for the location of the heat generator, especially if it is a gas appliance. Therefore, it is possible to plan the installation of the chimney only after marking the place of installation of the boiler.
Minimum distance of the passage through the wall from the openings( window, door) - 0,5 m.
To ensure good traction, the first, vertical knee should be at least 100 cm. It is attached to the boiler outlet with a clamp. If the features of the main laying dictate the need to extend this knee, then in combination with the other, the total length of the route in this section should not be more than 3 m. More than 2 elements of the pipe should not be installed, as the number of junction points increases, which is undesirable.
It is necessary to focus on the design features of the boiler. For a model with natural draft than the first knee above, the better. If the hood is forced( built-in fan), then the height of the vertical part of the track does not play a special role. Although there are also recommendations that the entire pipeline for such boilers should only be horizontal.
"Pass" of the wall
The hole is made in accordance with the section "coaxial".In this case, you need to focus on the material of the wall. If it is wood, additional thermal insulation is required( to prevent possible fire).The same applies to the heater, other layers( depending on the overall structure of the structure).
Feature
To ensure that the condensate does not flow back through the pipe, part of the trunk located outside the building is installed with a slope to the ground. This will ensure a natural removal of moisture from the chimney.
Assembly and sealing
In addition to the clamps that hold all the elements, various seals are used. In some cases, on particularly difficult sections of the route, to improve the sealing quality of joints, additional processing of such places with mounting foam can be carried out.
Useful tips
To improve the efficiency of the coaxial chimney, experts advise installing it so that the vertical elements are as small as possible. Simultaneously, the installation process is greatly simplified and the costs for the necessary additional elements( knees, transitions) are reduced. And the linear length of the vertical structure is somewhat larger, which also increases the cost of the arrangement.
When it comes to such products, it means their joint work with gas boilers. This is not entirely true. Coaxial chimneys are advisable to be mounted also in those cases when other devices having combustion chambers of closed type, for example, convectors, are used as a heat source.
You can meet quite a few recommendations on the self-manufacturing of a coaxial chimney from various materials. But is there any reason to do this if you consider that there is a significant range of relevant products on sale, the price of which is quite acceptable, and the quality meets all the standards?
For example, 1 m of the knee "coaxial" 80/100 will cost from 1,550 rubles. With a total length of 3 m, the cost of the kit does not exceed 5,900 rubles.
When installing the "coaxial" of industrial manufacturing, follow the manufacturer's instructions. Each product has its own characteristics, for example, according to the material. It can be ordinary or acid-fast "stainless steel", "galvanizing".In the installation of each product there are certain nuances. There are differences in the requirements for installation - the length of the horizontal section and the like. By the way, many types of coaxial chimneys can be installed and tilted( at an angle).
Before buying a coaxial type chimney, especially if you also buy a boiler( how to choose it, read here), you should take into account the design features of the heat generator - the diameter of the outlet pipe, its location on the body of the product. Only after this is chosen the optimal "coaxial" model.
DO NOT connect to one coaxial type chimney of several heating units!
