An integral part of the design of any furnace is the chimney. With its help, the combustion products that are harmful to life are removed from the furnace and a reliable thrust is provided to support the combustion process. Today, sandwich chimneys made of high-quality steel are becoming increasingly widespread. They are increasingly choosing private house owners for their furnaces and fireplaces. Why is this happening and what is the cause of interest?
Sandwich-chimney installation rules
Features of the sandwich-chimney design
The sandwich-chimneys are named after a fairly new technology in which layers of different materials are assembled into a structure resembling a normal sandwich. The body of the chimney consists of two pipes, which have a different diameter and are embedded one into the other. A thermal insulating spacer is placed between them, mineral wool or basalt fiber is often used. They are used because high resistance to high temperatures, open flame and resistance to active chemical substances in these materials at altitude. Still they are capable to extinguish sound waves and perfectly to keep heat.
Video - design and installation of sandwich chimneys
The type of sandwich-tube depends on its purpose and on the temperature conditions of the environment where it is intended to be used. They are different in diameter and thickness of the heat insulator layer. The connection of double-circuit pipes can be carried out in different ways: by bayonet, flanged or "cold bridge".
Components of the chimney system
Naturally, the smoke extraction system can not only be made of straight pipes. It should bend around the elements of the building that meet in its path, pass through the roof and the ceilings. It is assembled from sectional fragments, which are joined together by additional elements. The chimney consists of such basic elements: sandwich-tubes, tee elements for connecting the chimney structure with a furnace or fireplace fireplace, 15, 30, 45 and 90 degrees models are used to make a bend of the smoke path, a condensate collector for draining moisture accumulating on the chimney wallschannel due to temperature differences, elements of roofing to overcome roof structures with the organization of high-quality thermal and waterproofing, a revision tee with a door to control the cleanliness of the smoke removal channel and soot cleaning, I top edge of the chimney construction, the support bracket serving as a base under the wall or floor type of channel wall to secure the collar relative to the wall of the chimney;
The chimney system consists of the following main elements:
- sandwich pipes
- tees - elements for connecting the chimney structure with furnace furnaces and fireplaces, for branching the chimney channel
- of the bend - different chimney ducts are used for 15, 30, 45 and 90degrees
- condensate collector - for drainage of moisture accumulating on the walls of the chimney channel as a result of the temperature drop
- elements of the roof - to overcome the roof structure with the organization of a quality termo-and waterproofing
- inspection tee with door - to control the cleanliness of the smoke channel and to clean it from soot
- mouth - for the equipment of the upper edge of the chimney design
- support bracket - to provide a floor or wall base for the chimney
- wall clamp - to secure the chimneywalls;
Structure of sandwich chimney
Two-circuit chimneys - advantages and disadvantages
Two-circuit chimney with insulation
Positive aspects of this design:
- good appearance;
- perfectly matches with different models of boilers and stoves;
- is possible for both external and internal use, due to the ease and versatility of the structure;
- does not clutter the space from the inside, as, for example, brick chimneys due to much smaller volume;
- made of stainless steel sandwich pipes are not subject to destruction from chemical and thermal effects, that is, from the factors formed during the combustion of fuel;
- uses for many years no traces on the surface and does not damage the inner layer, allowing the design to reliably perform its function;
- high level of thermal insulation is guaranteed to protect against the formation of condensate, which is especially important when using equipment with direct extraction;
- smooth surface of the inner tube prevents the deposition of soot and allows you to rarely clean the duct of the chimney;
- high fire safety is ensured by excellent thermal insulation, which does not allow the outer circuit to heat up to critical temperatures that can ignite the combustible elements of the building;
- Convenient design, allowing to make turns and bends of the chimney, makes it possible to skirt any obstacles in the way of its laying, without resorting to dismantling or removing parts of the roof or floors;
- the whole construction can be erected without an additional foundation, which significantly reduces the cost and simplifies its installation.
Among the drawbacks characteristic of sandwich-chimney elements, it is worth mentioning their high enough cost, as well as the possibility of loss of tightness during long-term use. Due to the constant temperature gradients, the integrity of the structure is impaired. However, and with a guaranteed lifetime of 10-15 years, in practice they function normally much longer.
Preparing for installation
To ensure the maximum safety of the chimney penetration through the thickness of the floors, it is necessary to observe the correct sequence of its installation. To conduct a chimney through the ceiling, a specially prepared pipe is used before the installation. Its walls are laid with insulating material( mineral wool), and after that its internal part, joints and adjacency to walls are isolated. In order for the branch pipe to enter the ceiling in a certain section, a marking is made, along which an opening is made in the ceiling. On the abutments of the branch pipe to the ceiling elements, a layer of mineral wool is laid as an insulator, after which a chimney sandwich tube can be installed. Important! A sandwich pipe that runs through fire-hazardous areas, such as floor elements or walls made of wood and beams, requires the laying of an additional layer of thermal insulation.
Additional heat insulation of the chimney
When calculating the parameters of the pipe, it is necessary to pay special attention to their free running through the prepared holes, they must not come into contact with the ceiling of the ceiling. Joints in such places are unacceptable. To ensure ventilation and cooling, leave a free space between the nozzle and the pipe itself. After completing the installation of the chimney, the elements of the nozzle protection are installed, the vertical orientation of the chimney is checked. Important! The use of a sandwich tube for organizing the very first chimney element, immediately from the furnace, is strictly prohibited.
Sandwich chimney installation scheme
Rules for installing pipes
The installation of the chimney system starts from the bottom to the top, that is, from the most heating equipment in the room. It is necessary to insert the upper inner pipe into the previous one, and the one that is outside - to put on top of the previous one. This method allows to protect the heat-insulating layer from dampness. Installation of internal pipes is carried out "on a condensate", that is, so that moisture from the walls does not penetrate into the seams. Effective sealing for a long time provides the use of a sealing compound, with a range of operating temperatures from 100 degrees. For additional fixing of turns and joints, seams, tees, knees, special crimping clamps are used. Secure the chimney on the wall every 2 meters. Remember that the maximum length of one horizontal section should not be more than a meter. All places of passage of overlapping by a chimney system settle down with branch pipes, isolate with a mineral wool, according to the basic norms of fire safety. Regular channel cleaning is done by installing a removable part or by revising the holes with the door.
Accounting for installation distances
Allowance for distances when installing the chimneyWe need to measure distances by mounting the chimney: the flat roof must be under the pipe not less than 50 cm, if the chimney outlet is located 1.5 meters from the ridge, itIf the exit is at 1,5 - 3 meters, its highest point is equal to the height of the ridge, if the outlet is more than 3 meters from the ridge, its high edge should be at the level of the line connecting the ridge of the roofwith a slope of 10 degrees, if the roof of a fire-dangerous materals required to lift the edge of the system design smoke running on metr- a half above the ridge;
Rules for installing the chimney
With all the necessary materials and elements, as well as detailed instructions, you can independently install a sandwich chimney. However, the guaranteed quality of installation and reliable and long service, will ensure the appeal to professionals. Do you use sandwich chimneys? Write in the comments.
We also recommend reading about the waterproofing of the chimney with your own hands.
