Chimney height, its importance and functionality
The height of the chimney significantly affects the draft. This parameter determines the withdrawal from the room of combustion products, and prevents their settling on the inner walls of the pipes. In addition, from the height and material of the chimney depends on the quality of fuel combustion and rapid warming of the walls of the pipes, which prevents the accumulation of condensate.
Kohl mentioned the material, it is worth saying that when installing a brick chimney, special attention is paid to the processing of internal walls of the brick, in order to avoid settling soot and soot. The walls are made as smooth as possible, without using clay solutions( clay is a poor conductor of heat, which means there is a great chance of condensation and a decrease in thrust).
As you already understood, when installing a chimney, you need to pay attention to many factors, because everything is interconnected here. Particular care must be given to the design and calculation of altitude.
There is a kind of paradox. It would seem that the higher the pipe, the better the traction. But in practice, everything goes differently. A low chimney is bad, a tall chimney is also bad. And the answer lies in the aerodynamic resistance to which the exhausted combustion products are exposed. Thus, they last longer up the chimney, which leads to their slow cooling and heating of the walls. All this increases the mass of the combustion products and reduces the draft.
Design of a chimney. Key points when designing the
The location of the chimney installation depends on the layout of the room, the structure of the building and the roof. Chimney pipe for the oven, most often, it is customary to install in the kitchen. Also, it is possible to mount in a corridor or utility room, if their wall is shared with the kitchen.
If a boiler and a fireplace are installed in the house, the chimney must be removed to the roof. However, thanks to new technologies, it is possible to combine several chimneys into one chimney, however, one should keep in mind the standards and established standards. You must calculate the total volume of the exhaust gases from all sources and, based on the obtained data, determine the internal size of the chimney.
When designing, you need to consider all the points. In addition to height, you need to know the type of heating device, the type of fuel, the material of the chimney, its internal section and configuration. Also, you need to calculate the appropriate location of the chimney relative to the ridge and nearby buildings, as well as the direction of the winds in a particular area.
When carrying out qualitative calculations, you can save money on fuel consumption and improve the efficiency of most devices.
We make the correct calculation of the height of the chimneys according to SNiP
The document SNIP 2.04.05-9 states that:
- The optimum height of the chimney can be slightly above 6 meters, but not below 5 m. You need to count from the grate and up to the top.
- With a flat roof, the height of the chimney above the plane must be above 0.5 m.
- When it is located at a distance of 1.5m.from the ridge or high parapet, then its upper cut is made higher by 0.5 m.concerning the construction.
- When it is located at a distance of 1.5-3m.from the ridge or parapet, its upper edge is made level with them.
- When it is located at a distance of more than 3m.from the ridge or parapet, its upper edge is positioned so that an angle of 10 degrees is created between the "horse-pipe" and "skate-top-cut" lines.
For good and stable traction, pay attention to the cross section. If the chimney has a rectangular shape, then the rectangular section should be 1: 1.5, and the corners of the inner section must be rounded.
Rectangular chimney shall not exceed the cross-sectional area of 10 cm., But the diameter of the round can not be less than 15 cm( for a fireplace not less than 18 cm).
With regard to the calculation of the height of the chimney of the boiler room, then at 6-8m., The structure should be strengthened with stretches.
Before commencing self-installation of the chimney, read the fire safety regulations. If you are not sure of your calculations, consult an expert in addition to protect your life and save money.
