When building a room equipped with a fireplace, stove or other heating appliances with a solid fuel supply, it is important to pay sufficient attention to the smoke exhaust paths. The height of the chimney relative to the ridge of the roof must comply with established standards to ensure the normal exhaust of combustion products.
What affects the height of the pipe?
The height of the chimney pipe relative to the roof ridge depends not only on the type of roof itself, but also on a number of other important parameters:
- the roof area on which the chimney is located;
- the angle of inclination of the roof slope;
- the climate of the region in which the structure is located, the amount and intensity of precipitation;
- buildings and green spaces around the building.
These data are taken into account when performing calculations to determine the height of the chimney relative to the ridge of the roof.
Optimal value
Before starting construction work, it is important to determine the exact size of future smoke exhaust paths. Builders rely on the following requirements for the construction of a chimney.
- If it is located at a distance of 1.5 m from the ridge, then the height above the highest point of the roof should be at least 0.5 m. Such arrangement conditions provide good traction, and also limits the accumulation of snow in this section of the roof.
- At a distance of 3 m from the highest point of the roof, the height of the chimney relative to the roof ridge may be equal to the horizon line. This means that it coincides with the height of the ridge or slightly exceeds it.
- When located more than 3 m from the ridge, the height should be 10 degrees below the horizon.
How to calculate the distance from the chimney to the roof ridge? To do this, it is important to schematically depict the layout of the roof, to note the location of the smoke paths. Using the geometric method, it is necessary to scale down, multiply by the obtained height. Deviations are noted with a ruler and draw a line.
If the house is located among tall buildings or trees, the height of the chimney relative to the ridge of the roof should be 45 degrees greater than the highest point of the roof. Simply put, the chimney should rise above the ridge of 0.75 m.
Chimney and heating functionality
According to SNiP, the height of the chimney relative to the ridge of the roof must be calculated correctly to ensure normal smoke exhaust. In this case, air turbulences will be created that help to remove the flue gases from the system. The proper operation of the heater directly depends on good traction. It is the craving that helps to effectively remove harmful substances from the home. It is directly related to:
- the height of the chimney relative to the ridge of the roof in the country;
- temperature difference inside and outside the pipe;
- the correctness of the internal section. So, for example, a too wide chimney creates air flows that not only do not remove gases, but also contribute to the appearance of the reverse process;
- the design of the chimney, namely, the number of turns of the pipe;
- atmospheric pressure, high humidity, which help reduce traction.
You can determine the functionality of the chimney without lighting the stove. To do this, just light a match or a piece of paper, and bring it to the furnace. With good traction, the flame will begin to draw inward, or it may completely go out.
Possible problems
Often, before the start of the new heating season, owners of private homes face such a problem when all the smoke begins to pour into the room. This may be due to the following factors:
- hit of a bird of an internal part of a pipe;
- a large accumulation of soot;
- the collapse of the pipe.
If you want to avoid this, before starting the furnace you need to check the furnace and the smoke exhaust paths, clean the pipe from soot and carbon deposits.
What should be the chimney?
It is important to take care not only of calculating the height of the chimney pipe above the ridge of the roof, but also over its volume and shape. The best option is round pipes, since they do not form additional air vortices that prevent smoke from escaping. In addition, compared to square tubes, they do not have angles in which a large amount of soot and burning can accumulate.
Tall pipes must be secured with additional struts to ensure stability. A cover is usually installed on top, which ensures that no foreign bodies and sediments get inside the system.
Important points when calculating the chimney
The parameters and calculations of the height of the chimney above the roof should be as correct as possible to ensure comfortable use of the heater. It is important to consider the following points:
- the choice of material for the manufacture of the chimney should take into account the selected fuel for the furnace, since different types have different combustion temperatures, and accordingly, the temperature of the smoke;
- providing good ventilation for the exhaust of exhaust gases. Most often, the equipment is combined in one chimney;
- design features of the building and distance from the ridge.
Solid fuel heating appliances have a great fire hazard, so if you had no previous experience in calculating the height of the chimney, then you should use an online calculator or entrust this business to professionals.
Dependence of height on section
How to calculate the height of the chimney above the ridge of the roof, taking into account the shape of the cross section of the pipe? The norms are regulated by SNiP - a document in which there are permissible characteristics of heating devices and smoke vents. It is recommended to study these provisions before starting the calculations.
The gases and smoke released during combustion have a high temperature and move up. To ensure good traction, the gases should have a low temperature, and the distance from the furnace to the exit should be small. However, in reality this is not always the case. The best option is a small cross-section of the pipe in combination with a large height. Thus, traction can be increased. If it is too large, the heating capacity of the furnace will decrease and, moreover, much more fuel will be required. In order to avoid this, it is important to consider all the parameters of the building, its location, heater and pipe.
Materials for the construction of the chimney
The initial requirements for the materials used for the construction of chimneys are fire safety and low cost. The following valid materials exist:
- Brick is durable and safe, but it has a high cost and a tendency to accumulate soot.
- Asbestos cement, unlike bricks, is cheap, light and easy to install. However, such chimneys are categorically not suitable for furnaces, the furnace of which is planned by substances having a high combustion temperature.
- Stainless steel is easy and quick to install, not susceptible to corrosion, has a low weight and cost. However, when choosing, it should be borne in mind that stainless steel does not have heat-insulating properties, it cools quickly, requires additional insulation in places of contact with rapidly igniting materials.
- Double-circuit steel structures have several of the following advantages: high speed of smoke passage through the system, no condensation is formed, ease of installation.
- Ceramic chimneys have appeared on the building materials market relatively recently. They have the following characteristics: tight structure, circular cross-section and perfect smoothness inside, which ensures unhindered passage of smoke, long service life, and resistance to temperature changes and natural precipitation. In addition, such structures are protected by heaters from non-combustible building materials, have protective boxes. The only obstacle to installation may be the high cost of this design.
The chimney has a significant impact on the normal operation of the entire heating system, so it should be especially important to design and install it, as well as maintain operability during operation.