Stove in a private house not only comfortable to spend time, but also rational to spend money on heating. For safe operation requires proper installation. Several decades ago, the furnace installation was possible on a specially flooded the basement and chimney laid out from a brick. The development of technology has made available not to fill the heavy foundation and arrange dymootvedenie light systems. These include construction of the sandwich pipe smoke.
Design features
The name comes from the English word "sandwich" or "layered." The system has gained acceptance because of its ease of installation and low weight. Developers were able to build with their own hands. In fact, how to do it correctly, you can find out by studying the recommendations.
The structure consists of two tubes of big and small diameters, between which the insulation is distributed to the insulation against mechanical damage and temperatures. And the outer and inner sheets are assembled from stainless steel, connected to the argon plasma welding environment. In this method the seams are obtained, similar in structural characteristics to the steel properties. Middle pave insulation, non-combustible stone wool.
On the insulator thickness affects a number of factors:
- the difference of external and internal diameters;
- Temperature range during operation;
- size of the outlet of the heating furnace.
Sandwiches are made from different types of steel: galvanized and stainless. May vary in diameter of the outer tube and insulation thickness. Can not be used in various heating ovens of the same characteristics of the pipe. Therefore, the choice is made depending on the characteristics of power and temperature.
sandwich assembly can be done in different ways:
- Mounting by means of corrugated edges. Plus is the ease of assembly, but in this case it is necessary to seal the joints, which greatly increases the cost.
- Compound sockets. The main advantage is the high level of sealing achieved with the installation. Minus - a complicated installation because of the high accuracy of adjusting parts.
- Mounting crimped edges. The advantage is considered to ease of assembly, and the lack of an increase in cost due to the expensive caulking sealant.
- Compound sockets. The main advantage - a high level of sealing achieved with the installation. The downside is the complex assembly of high-precision adjusting parts.
Minimum service life correctly mounted chimney for about 15 years, but regular brushing and lack of congestion at extreme temperatures of operation may last considerably longer.
Pros and cons of the use of chimneys
The simplicity in the construction of low weight allow smoke extraction system installed in any home. Since the choice of the chimney - it is a very critical part of the building, you need to carefully examine all the parties to the end. Sandwich pipes used in the installation of the chimney are the pros and cons:
- In the process goes dymootvedeniya considerable heating only the inside. The outer tube is cold or moderately warm due to rock wool insulation. This reduces the possibility of burns and fires.
- Rapid heating of the insulated pipe increases thrust.
- On the smooth steel surface of the soot settles less frequently than on a brick or ceramic. Ease dymootvedeniya not conducive to accumulation of condensate, the products of combustion do not enter into reaction with water.
- Multi-layer provides protection functions. The outer layer protects the inner tube against mechanical damage, and itself is isolated from exposure to high temperatures.
- On the outer tube, a slight condensation.
- Weight significantly easier brick chimney, the device can be installed without additional base.
The disadvantage is the possibility of partial depressurization joints after about 10 years of work.
The procedure for calculating
To determine pipe diameter of the sandwich is necessary to know beforehand the conditions in which the operation will be performed. By the size of the heated space area selected is suitable for the oven performance. To heat a 10 sq.m. needs 1 kW of power, respectively, for a room of 50 square meters. meters suitable furnace with a capacity of 5 kW.
On the type of boiler and heating fuel used depends on the temperature of exhaust smoke. The greater degree in the chimney, the stronger is its heating. temperature ratio of height and form the heater table clearly shows.
The temperature of the smoke in the different boilers:
| Type of heating boiler | Temperaturesmoke, C |
| Stove | 350-650 |
| The stove | 400-700 |
| Jetstream furnace | 160-250 |
| pellet boiler | 120-250 |
| A gas boiler | 120-200 |
| diesel boiler | 150-250 |
| Solid angle | 500-700 |
In a sandwich chimney most strongly heats the inner pipe, so primarily the diameter selected. The more powerful the oven, the wider it should be. With increasing power needs to be increased and the inner hole. power calculation can be found in the table below:
The average values of the ratio of the power of the boiler and chimney section:
| The boiler output in kW | The cross section of the chimney, mm | S output diameter square. mm | The diameter of the pipe |
| less than 3.5 | 140 x 140 | 19 600 | 158 |
| 3,5 – 5,2 | 140 x 200 | 28 000 | 189 |
| 5,2 — 7 | 140 x 270 | 37 800 | 220 |
For open furnaces the flue channel must exceed 1/100 of the volume of the boiler. In closed boilers, where the air passes into the furnace from the lower blower, the inner area of the outlet section of the chimney must exceed the dimensions of the feed hole. If the diameter exceeds the calculated half times or more, the pulling force decreases, and swirls are formed inside the flue.
The apparatus allows the layers in the sandwich isolate the outer tube from the effects of high temperatures, specifications prevents the formation of condensate. Stone wool noncombustible, its thickness depends on the temperature of the fumes exiting from 25 mm at 60 C and 100 mm at 600 C.
Calculation of the height of the chimney
For safe operation and outputting the products of combustion outside of the living area of the pipe must exceed a height of 5 meters. Otherwise, the operation becomes unsafe due to violations of draft and smoke a residential zone. The most common height is 5-10 meters.
On pitched roofs ridge dimensions exceeding sandwich pipe for chimney should extend at least, than 0.5 m, if the tube axis is located at a distance of half a meter or less from the highest point. If the distance is 1.5 - 3 meters, the upper point of the pipe should be flush with the ridge. If the tube axis is located within three meters, the upper point of the pipe must be lowered from the ridge 10 degrees.
For installation on flat roofs taken into account the general minimum size of the sandwich pipe, equal to 500cm. Location top of the chimney should be 0.5 - 1.5 m. Chimneys allowed to make a specified height in excess 10-30sm provided mandatory installation securing the stretch marks.
Criterias of choice
For different heating boilers need to individually select the type of high-alloy stainless steel sandwich chimney. The combustion products generated in the tube may contain chemically active substances:
- sulfur;
- sulphuric acid;
- hydrochloric acid.
The temperature of the exhaust fumes can differ considerably when using different fuels. All figures are distinguished by the level of exposure to different grades of steel. The most common ones:
- High alloy steel AISI stainless steel alloy stabilized with titanium. Maximum use temperature is 800 C. In a medium containing sulfur is subjected to corrosion.
- High-alloy steel AISI stainless steel, molybdenum stabilized. Is stable to acid, does not corrode, is resistant to aggressive substances.
- The refractory AISI steel alloy with a high content of chromium and nickel. It applied at elevated temperatures up to 1000C. Use at 600C adversely affects the structure and leads to embrittlement.
- AISI 409, AISI Poor resists high temperatures and has a low resistance to acid. This brand is most often used in the manufacture of low-end models.
In layman can not be estimated by a visual grade of steel. The only possible way to check is to use a magnet. low quality alloy will it draw, and no highly doped.
Good insulation provides insulation from heat and fire, so you should choose a trusted manufacturers. These are Paroc, Isproc and Rockwool. Stone wool is used at temperatures up to 600C. Insulation thickness is 25-50 mm, depending on the temperature rising fumes indicators which vary based on the type of fuel used. In chimneys derived outside, the insulation layer should be maximized.
Assembling the chimney sandwich with their hands
The chimney can be installed with no experience in construction. Prior to installation you must select the type of assembly:
- The smoke, when the lower section into the upper stand. For light stoves and fireplaces made of cast iron.
- Of condensate, wherein the lower member is inserted extending above. It is used in gas boilers.
Installation through the roof begins with a heater. The walls of the chimney is isolated or calcium silicate mineritom. The order of assembly is as follows:
- The lower element because of exposure to high temperature is set from galvanized steel and after the connection with the boiler to prevent heating locked clamp.
- Units are assembled, starting from the one having the smaller diameter. In this step, it is important to check there are no obstacles for the discharge of condensate. Tubes going indoors top tube outwardly, and side streets assembly passes by mounting the upper tube inside.
- Connect the outer and inner tubes. The joint is reinforced by a coil and galvanized clamp is tightened.
- Ready chimney sealant to withstand 1000C.
With the passage of overlap the special role given to fire safety. For pipes to be prepared hole 70 and X 70 is filled with incombustible basalt wool. When passing through the roofing elements of special type of master flash the joints are sealed with a chimney.
When the assembly is arranged on the wall at home and is strengthened with wooden bars opening at the junction of the street. First mounted bracket, and after him a tee. The wall closes first plywood, asbestos and then a metal sheet that is varnished to protect it from rust.
Tools and equipment
To collect high-quality chimney, you need to prepare all the necessary tools and materials:
- Pipe assembly kit with accessories for roofing;
- protective umbrella precipitation for mounting on a roof;
- stainless steel starting tube;
- heat-resistant silicone sealant;
- support bracket;
- collars;
- rock wool, reinforced with foil;
- Miners or calcium silicate insulation for walls;
- Metal sheet;
- Saw Bulgarian;
- drill and dowels;
- screwdriver;
- hammer;
- protective gear.
Recommendations regarding use of the chimney sandwich pipes
After completion of the assembly is necessary to melt the furnace. This is necessary to verify the general structure and the lack of tightness overheating of individual elements.
Between the start of operation of the system may cause smoke and odor. When the burn through oil residues, dirt and silicone sealants on pipes, such phenomena will disappear.
In operation, the soot accumulates within the tubes. Over time, this leads to a reduction in the diameter of the chimney. In order to prevent fire, it is necessary to clean the pipe twice in the heating season. Do not clean the chimney using household chemicals.
Assembling the chimney sandwich the power even to laymen. The result depends on the material quality and compliance with regulations. Chimney, properly assembled with their hands from a sandwich pipes will last for many years.
