The chimney is an integral part of the fireplace and the most important factor in ensuring its functionality. The quality of using the fireplace directly depends on the chimney characteristics, because even the best fireplace insert with a poorly made chimney will not justify its cost.
Conversely, an ordinary stove with a double-circuit steel pipe, with good smoke characteristics, can be quite successfully operated.
By location, chimneys are divided into the following types:
- Internal chimneys, located inside the warm contour of the room, which pass through its entire height and exit with a pipe to the roof, are sometimes located in the load-bearing wall.
- External chimneys with a side pipe, when the chimney for the fireplace is led out to the side outside the outer boundaries of the room and along the wall is led up, often bypassing the overhang of the roof.
Let's take a look at the basic operational requirements for chimneys:
- Security. Its main criterion is the ability of the chimney to endure for a long time the high temperature of gases and strong temperature drops, without collapsing and without losing its tightness and thermal insulation.
- The efficiency of the chimney is determined by the characteristic of gravity per one running meter of the chimney. For different diameters and materials of the chimney, there are different gravity values. A large diameter of the chimney is more efficient, in addition, the shape of the section and the roughness of the surface are of importance, a circular section with a smooth surface is preferable from the point of view of aerodynamics, since with this shape fewer parasitic vortices are formed.
- Convenience of service and repair. Each chimney has its own service life, in addition, all chimneys require periodic cleaning and maintenance, the chimney design must be such that maintenance is carried out quickly and without disassembling the main components.
- Durability. The main destructive factor affecting the chimney is the chemical environment, which is formed as a result of the dissolution of soot deposited in the chimney by condensate flowing down the chimney. The key factors in ensuring the durability of the chimney are the ability of the chimney material to resist aggressive media and reduce the volume of this medium. To do this, it is necessary to choose chemically resistant materials and insulate the chimney with non-combustible insulation to reduce the volume of condensate.
Currently, there is a fairly large assortment of different materials for chimneys on the market, but we will immediately make a reservation, within the framework of this article we will only talk about those types of chimneys that are suitable for use with modern productive furnaces.
Asbestos-cement, corrugated and polymer chimneys are not suitable for use with modern furnaces, since they cannot be operated at high temperatures and do not have sufficient durability.
The main types of chimneys:
- Brick chimney - classic authentic version, time-tested. The decision to install such a chimney should be made even at the design stage of the house, since such a chimney requires the installation of a powerful foundation, or is generally placed in a load-bearing wall. The advantages of such a chimney are high durability, strength, good fire resistance. Cons - high price, worse traction with a rectangular cross-section compared to a round pipe, low maintainability, high soot deposition rates due to a rough inner surface.
- Single-circuit modular stainless steel chimney - the cheapest option of all, consists of separate modules-pipes, one meter long, elbows and tees, which are assembled as a constructor for a sealant. The advantages of this type of chimney include low price and ease of installation. The disadvantages are the high heating temperature, which requires large indents from the building structures and low durability, about 10-15 years, associated with the formation of a large amount of condensate.
- Double-circuit modular sandwich chimney made of stainless steel - has the advantages of the previous version, such as ease of installation, and at the same time has quite acceptable durability, since the formation of condensation is reduced due to the insulation of the pipe. On average, the manufacturer gives a guarantee for such pipes for about fifty years. It has only one drawback - a rather high cost.
- Ceramic chimney - a chimney from stacked ceramic glasses wrapped in thermal insulation and installed in hollow cinder blocks. The glasses are connected to each other on a sealant, the blocks are placed on the solution. It has all the advantages of a brick chimney, but has a round smooth cross-section, which reduces the deposition of combustion products. Disadvantages - some features during installation, high weight, the highest cost.
The choice of a chimney and its installation is a very responsible process, which is better to be trusted by specialists.
Calculation of the chimney cross-section is the first and most important stage. We recommend using the Swedish cross-section calculation formula, which most fully allows you to simulate thrust.
Installation features are very different depending on the choice of chimney material.
So, in the case of buying a chimney kit from an insulated sandwich pipe, the main thing is to ensure the tightness of the docking of the modules, close the fire-safe circuit, and correctly organize the outlet of the pipe to the roof. At the same time, it is quite easy to bypass the supporting structures of the floors by installing additional elbow bends. When installing brick and ceramic chimneys, the main thing is to ensure good bearing properties of the foundation; it is also necessary to remember about the impossibility of organizing a simple bypass of building structures.
When the main task of the installation - to isolate the fire-safe circuit - is completed, you can think about finishing the chimney. Finishing the chimney and dampers is a creative process that is inextricably linked with the design of the room. In the case of a chimney from a sandwich pipe, the finishing can be done by constructing a plasterboard box on metal profiles, protected from the inside by thermal insulation. If the chimney is made of bricks or blocks, it can be left as it is, in the interior loft style, or revetted with natural stone, marble, or mosaics. In general, finishing the chimney and fireplace is not difficult if the insulation of the fireplace is made using technology. The fireplace is the best decoration of the room, it creates warmth and coziness.