The correct operation of the fireplace depends on the design of the firebox and the correct installation of the chimney. It is important to take into account everything, from the calculations of the pipe cross-section to the nuances of thermal insulation. Only a well-made chimney will allow you to heat the room well.
Chimney operating principles
The chimney for the fireplace is a sealed shaft of vertical, horizontal or inclined shape. It should fit snugly against the combustion chamber of a fireplace, stove or boiler.
The chimney section is:
- round;
- oval;
- rectangular;
- polygonal.
Each wiring diagram should be selected depending on the structure of the building and the type of fireplace.
Chimney working principle:
- ignition of the fuel placed in the furnace starts the process of generating heat and smoke;
- the temperature of the combustion products is 500 degrees Celsius, they lose weight and rush towards the mine;
- cold air causes the convection process, increases the traction force, whereby the combustion products are displaced outside;
- oxygenated air supports the combustion process.
The quality of home heating and the safety of residents depend on the correct construction of the chimney system.
Placement methods
There are two methods for placing a fireplace chimney. Each of them has its own characteristics, advantages and disadvantages. The choice of method depends on the location of the fireplace, free space in the house and the type of chimney itself.
Internal
If the place for the chimney is prepared on the roof, it is better to use the internal chimney positioning method. In this case, the shaft will have a vertical shape, rising to the roof above the heater. The smoke extraction system, made of a material with good thermal conductivity, will reduce heat loss in the room and reduce fuel consumption to maintain the required temperature.
The complexity of this method lies in the laborious process of cutting into the interfloor surface and the roof during the procedure for laying the chimney shaft. Also, this method is considered to be quite fire hazardous.
It is recommended to place pipes near partitions and internal walls, to carry out sealing by roof cutting.
A significant plus of the internal location is to protect the entire structure from temperature changes in the winter season. The main disadvantage is the loss of space inside the house.
External
The method is not popular on the territory of Russia and is used only when it is necessary to install a heating unit in a private house, which was not taken into account in the design.
Installation of the chimney by this method consists in bringing the chimney through the wall, which is adjacent to the fireplace, to the street. From the place where the outlet was, the pipe rises to the height of the ridge and higher. This provides better traction.
Place the outside of the pipe 0.5 m from the edge of the roof to reduce the risk of fire. It is also required to insulate the outer pipe, this will exclude the accumulation of moisture from the combustion products. Wall mounting is carried out with brackets.
Fireplaces in a house with an external chimney installation in the wall save space in the room by moving part of the chimney system outside the house. In addition, this method of placement is more rational from the point of view of fire safety. However, there is a drawback: if you do not insulate the pipe, condensation will form, which will lead to a malfunction of the chimney system.
Types of chimneys for a fireplace
The construction of the chimney may differ in the material of manufacture, which is more of a decisive factor. Only after reviewing all types of material can you decide which of the chimneys is best for the fireplace.
Brick
For the construction of the chimney system, fireclay solid brick is used, since it is more affordable and is a traditional material. It is fireproof and can last for many years with proper care.
Special requirements are imposed on the cement composition with which the brick is laid. The solution should include sand, cement and lime in a ratio of 5: 2: 1. Only such a solution can fully provide a connection that will be sufficiently tight and resistant to heat. The support can be a load-bearing wall or slab.
Another important parameter is the smoothness of the inner pipe - the mortar should not protrude from the seams inward.
The shape of a brick chimney for a fireplace should be square or rectangular. To strengthen it, it is better to use anchors, install them at a depth of at least 20 cm. To prevent the pipe from collapsing, it is required to carry out the procedure for reinforcing its walls. Through every third row, the masonry is reinforced with reinforcement.
Steel
The chimney for the fireplace stove can be made of steel. In this case, the combustion temperature should not exceed 400 degrees. Such a system will come out cheaper, it is much lighter than a brick chimney, so there is no need to make a foundation platform. The steel chimney will last from 15 to 20 years.
Steel chimneys are divided into two groups:
- sandwich pipes with a heat-insulating layer;
- simple pipe without thermal insulation.
The air duct is made in the form of a cylinder, which increases the draft of the fireplace. Soot and ash hardly settle on the pipe walls, which is also an advantage.
Ceramic
The material is able to withstand up to 1000 degrees, is not affected by chemical elements. The advantage of such a fireplace is slow cooling, which will save fuel when heating the room. Smooth inner walls prevent combustion residues from accumulating inside the chimney. The service life of the fireplace is from 30 years.
During installation, you will need a special assembly adhesive, which better seals the elements, and a heat-insulating circuit made of heat-resistant material. Such a contour can be a block of lightweight aerated concrete, which is treated with a heat-insulating layer.
The main disadvantage is the large weight, which requires the installation of a separate foundation.
Glass
Tempered glass can be used when installing the fireplace and installing the chimney. Such a fireplace is absolutely insensitive to the effects of chemicals and has smooth walls, so combustion products do not clog the mine. However, it is best to regularly wash the visible areas so that the glass does not lose its attractiveness.
The most difficult part when installing a glass chimney is to ensure the tightness of the joints. Also, the glass accumulates condensation, so work on the thermal insulation of the circuit is needed. Such a fireplace is more expensive than others.
Selection requirements
The rules for installing fireplaces and their components are regulated by the following standards:
- SNiP II 35 / 2.04.05-91 / 2.01.01-82;
- DBN V.2.5-20-2001 and NPB 252-98;
- GOST 9817-95, etc.
In them you can see the main nuances and features of the installation of heating equipment.
Chimney size calculation
To calculate, you need to know:
- fuel characteristics;
- boiler characteristics;
- gas rise rate;
- the amount of fuel burned;
- chimney shape.
Calculated by the formula V = (B * V * (1 + t / 273)) / 3600 m³ / swhere V - the volume of air required for combustion of 1 kg of fuel, B - the mass of firewood that burns per hour, t - temperature of outgoing gases. The result is rounded up.
Chimney assembly and installation
When assembling the chimney pipe, you must adhere to the following instructions:
- you need to start from the bottom up after fixing the firebox;
- seams should be tightly sealed;
- pipe elements are connected to each other;
- the pipe is pushed onto the branch pipe and fixed with a clamp;
- in the lower part, an element is mounted that holds the pipe when the temperature changes;
- in the roofing part, the pipe is crimped with a clamp and reinforced with rivets;
- a metal corner is placed in the opening of the overlap, a pipe is placed in it.
After installation, you can make a brick cladding and insulate the pipe. A visor can be installed on the top, this will protect the chimney from moisture and clogging.
DIY chimney construction
You can build a chimney system with your own hands. In this case, two types of material are used - brick and steel.
Stainless steel
When installing a stainless steel chimney pipe, it is recommended to follow the instructions below.
- The steel pipe is pushed onto the nipple. It needs to go in the direction of the smoke.
- A gate is installed to block the channel. The joints must be coated with a sealant.
- A sandwich-type chimney is put on the structure. Other rolled metal products are installed on it.
- All elements of the pipe are assembled, and the rolled material is wrapped in clamps.
- The pipe is passed through the roof. In this case, you need to use pads - an apron and a conical crisis. The end part is equipped with a cone.
After this, the process is considered complete, you can load fuel into the heater.
Brick
Construction of a brick chimney system:
- The laying starts from the bottom, from the stove. Each row is checked by a level.
- The installation site of the gate is reinforced with a frame.
- Laying continues until the beginning of the plowing construction. The plowing should fit well to the ceiling joists.
- After plowing, you need to go to the size of the chimney, pulling it to the roof.
- An otter is laid out on the lower part of the roof. For stability, steel plates can be embedded in it.
- The head is laid. The outer perimeter of the pipe is increased by a quarter of a brick. A protective cap is put on top.
You need to take 2-3 days to dry, after which you can heat the oven.
