Our ancestors living in the territory of almost the coldest country on the planet, in the winter they warmed their homes with wood-burning stoves. In an era when each residential building is equipped with a gas cat, stoves and fireplaces have become exotic, the installation of which serves as an element of decor, and not a practical necessity. However, these devices are still heating, and therefore require the organization of smoke removal. In this article we will describe how the chimney is made for the fireplace.
Device and principle of operation
Chimneys for fireplaces or stoves - the channels through which the removal of a mixture of gases, which are products of combustion of fuel, from the heating device of the heating device into the atmosphere. The design of these elements of the heating system is in the form of a pipe or brick shaft, the tightness of which determines whether the system works correctly. Chimneys for fireplaces and stoves are necessary, because without them it is impossible to operate heat-generating appliances, whose work is as follows:
- Fuel is placed in the furnace of the heat-generating equipment (stove, fireplace, boiler). Most devices operate on wood, gas, compressed or coal, fuel oil.
- The fuel is ignited using an open flame source, as a result of which the system generates a large amount of heat, which goes to maintain the optimum temperature in the room, and smoke.
- Smoke, which is a product of combustion of fuel, consists of a mixture of carbon dioxide and carbon monoxide, ash, soot, and other aggressive chemicals. The temperature of the smoke entering the chimneys for fireplaces or stoves reaches 400-500 degrees, therefore, obeying the law of convection, it rises, freeing up space in the furnace for cooler air.
- The design of smoke removal channels is a vertical sealed shaft, through which hot smoke rises only up. Thanks to this process, fresh air, saturated with oxygen, necessary to sustain combustion, enters the furnace.
The process of sucking oxygen-rich air into the firebox is called a burden. To check the chimneys for fireplaces on the presence of traction, you need to bring a lit match or a candle to the firebox: if the flame deviates towards the smoke removal channel, the system works correctly. In case the flame of the candle burns evenly, they speak about the absence of thrust. But the most dangerous situation develops when a reverse thrust is formed, a flame deflecting it in the opposite direction from the chimney signals it.
In order to properly make a smoke exhaust channel for a stove or fireplace, you need to carefully study the information on the heating device specified in the instructions, as well as calculate the volume of gas in the furnace. Mounting the chimney for the fireplace with your own hands is quite difficult, since this complex structure requires special knowledge and experience, which only experienced craftsmen can boast.
Ways to post
Assembly and connection of the smoke removal channel occurs after the installation of the heater. However, choose a place and perform the calculation of the cross-section and height of the chimney must be prior to installation. Chimneys for fireplaces or stoves are placed in two ways:
- Internal placement. This method of placement involves the installation and connection of the smoke removal channel inside a heated structure. On the territory of Russia, the stovepipe chimney was traditionally placed in the house, leading to the street through the roof. Installing a channel inside allows you to protect it from freezing, as well as to reduce heat loss occurring in the area passing along the street. In this case, the calculation is made on the fact that while the smoke moves through the pipe, it gradually cools down, due to which condensation does not occur. The traditional internal placement method has 1 negative side: the pipe, especially brick, takes up a lot of space in the room. In addition, it increases the risk of fire.
- Exterior placement. Installing a pipe outside the building allows you to increase the usable area of small rooms. In this case, the chimneys for fireplaces lead through the wall, located near the heater, directly on the street. This technology came to Russia from America and Europe, it became popular with the advent of effective thermal insulation materials used for channel insulation, and sandwich pipes that do not freeze even in the most severe frost. The minus of the external placement is that due to the large difference between the external and internal temperature in the chimney a large amount of condensate is formed. To make a high-quality external smoke exhaust channel, you must perform a detailed calculation of the dew point and organize the insulation. However, placing the pipe outside the building reduces the likelihood of fire and is considered safer.
Note! The calculation of the smoke removal channel of the heater determines the recommended cross section and height of the pipe, calculates the required level of thrust to maintain combustion. When calculating these parameters take into account the power of the device, the type of fuel used, the location and the climatic conditions in the construction region. Chimneys for fireplaces are built on the basis of a project that takes into account all the above factors, and the connection is made under the supervision of a professional master.
Chimneys for fireplaces are made of various materials that have high heat resistance, low thermal conductivity, excellent refractory qualities, do not enter into oxidative reactions with water, and also do not interact with aggressive chemicals that are contained in the combustion products. To make a durable and reliable smoke removal channel for the furnace, use the following materials:
- Brick. It is a traditional material for the construction of furnace chimneys, as it has excellent heat resistance, does not burn and with proper care lasts more than 100 years. For the construction of the pipe used solid, burnt brick, the cost of which is higher than a simple silicate. This method is one of the most expensive because of the high price of the material, the need to fill a deep foundation. In addition, it is unlikely to make a brick chimney and make a connection to the furnace with your own hands, you have to spend money on hired craftsmen, whose services are expensive. The brick mine has a rectangular or square cross section, therefore, in the corners and on the rough surface of the material, soot and ash are deposited, causing congestion.
- Ceramic pipes. More affordable is a ceramic chimney, which consists of pipes and blocks of lightweight concrete for their installation. It has a more compact size, so it is installed both inside and outside. The lifetime of ceramic pipes is 30 years, but proper maintenance and regular cleaning increase this period by 10-15 years. Ceramic smoke removal channels are lighter than brick ones; they are installed on a monolithic base of concrete pipe, so the need to fill the foundation disappears. There are models with a thermal insulation layer that are suitable for solid-fuel heaters, where the temperature of the combustion products exceeds 300-400 degrees.
- Sandwich pipes made of steel. The most democratic and affordable material from which to make chimneys for a stove or fireplace - a sandwich pipe. They represent two hollow steel cylinders, inserted one into the other, with an insulating layer between them. Sandwich pipes are lightweight, easy to install and serve 15-20 years. Components for the assembly of the chimney are selected according to the diameter of the inlet nozzle of the device by performing the calculation of the required height of the chimney to maintain a normal level of thrust.
Important! The material for the assembly of the chimney is chosen based on the type of fuel on which the heat generating device works: for fireplaces and stoves working on solid fuel, brick and ceramic pipes are better suited, with a smoke from gas models, steel sandwich pipes do a good job.
Requirements for smoke removal channels
The use of heating partitions is associated with the risk of fire and carbon monoxide poisoning, therefore, strict requirements are imposed on the smoke removal channels, the task of which is to protect users. In order that the operation of the equipment does not cause problems, the following conditions must be met when installing the chimney:
- The diameter of the pipe is chosen in accordance with the size of the inlet pipe of the heat-generating equipment. If the pipe is larger, the connection between them will be untight, which may cause carbon monoxide to leak.
- The connection, laying and passage of the pipe through the walls or floors are insulated with refractory material to prevent overheating of the finish. For these purposes, a base metal or asbestos cement is used.
- The length of the smoke removal channel is determined by performing the calculation of the required thrust, but its height from the firebox to the tip should not be less than 5 m. The higher the chimney, the greater the thrust in it.
- The pipe end is removed on the roof at a distance of 0.5-1 from the ridge or through a wall at a height of 1-1.5 m from the soil level. The chimney is raised 0.5 m above the highest point of the roof.
- The smoke exhaust channel is located mainly vertically, avoiding more than 3 turns. The length of horizontal sections should not exceed 1 m.
- The cylindrical shape of the section is considered the best option for the pipe, however, rectangular and square shafts are allowed.
Important! Experienced furnace masters advise when discussing the draft of the fireplace to insist on the placement of the chimney inside the house, and it must be at the inner, not the outer wall. With this installation scheme, the channel turns out to be warmer, there is no shortage of traction and condensation of vapors in it.