The proper arrangement of the chimney is an important requirement for fire safety and the norms for using stove heating in a private house. If installed improperly, carbon monoxide may appear in the room. This is unsafe for people living in the house.
To avoid errors during the installation of chimneys, new materials have been developed. They differ in a number of advantages over conventional designs for all. This is a sandwich chimney. They differ in the mass of positive characteristics. They will be discussed later.
general characteristics
Sandwich chimneys for boilers and furnaces began to be used in construction relatively recently. This is a structure that consists of three layers. It has two pipes that differ in diameter. Most often, stainless steel is used for this. A small pipe is installed in the center of the large pipe. Between them is a layer of thermal insulation. Thanks to this design, this type of design began to be called a sandwich.
The inner pipe is necessarily made of stainless steel. It is exposed to various adverse effects. Therefore, the quality of this material put forward increased requirements. The outer pipe can be made of ordinary galvanized steel. Other types of materials may also be used for the outer shell.
On sale are insulated chimneys, sandwiches, which differ in diameter and thickness of the insulating layer. When choosing, take into account what temperature loads will act on the pipe.
The presented type of construction can be used for houses that are built from any type of material. This versatility has made multilayer pipes popular. The disadvantage of such products can be considered its relatively high cost. However, given that these pipes increase the safety of the heating system, this minus can not be taken into account. At the same time, the equipment presented is characterized by a mass of positive qualities.
Benefits
Chimney sandwich for a bathhouse, a residential building and other objects today is used much more often than other types of structures. This is due to the many advantages of such pipes. They are easy to install. Even an inexperienced builder will cope with this task. Having considered the theoretical foundations of the installation process, the installer will be able to perform this work without errors.
The presented chimneys are lightweight. They practically do not burden the roof structure. This allows not to mount a separate foundation for furnishing the furnace, save on the purchase of additional materials. Also pipes of this type are compact. They can be easily transported to the site.
Maintenance of the presented designs is also very simple. If necessary, you can replace any failed layer. This significantly increases the life of the product. Pipe installation can be done with an exit through the wall or roof. The use of insulation will reduce the temperature difference, to prevent freezing of the material. This greatly increases the fire safety of the structure.
The smoke in such pipes does not stagnate. It quickly gets out of the system. This is facilitated by the absolutely smooth inner surface of the pipe. Also in this design soot is practically not formed.
Materials of construction are resistant to corrosion. They are easy to operate. All that is required is a periodic inspection of the chimney. At the same time, the appearance of such a pipe is aesthetic, which allows you to harmoniously combine them with the existing roof finish.
Specifications
They make sandwich chimneys from stainless steel and other similar materials. The inner tube is created from materials that are especially resistant to the negative effects. Therefore, this part of the structure is made of steel grades 316 TI, 310S. They withstand heat. Its maximum value reaches a thousand degrees. This factor is especially important when creating a chimney for a bathhouse or solid fuel boiler. Here, the system maintains the highest possible temperatures. Due to its specific characteristics, pipes from the presented steel grades are used for a long time.
Stainless steel sandwich chimneys are designed to operate at a temperature of about 850 º. Moreover, the material can withstand its fluctuations and rises up to 1200 º. The outer shell is rarely made of stainless steel. For this, cheaper metal grades are used. However, the outer layer of pipes is not subject to temperature extremes, climatic and weather influences.
Between two metal pipes is a layer of insulation. For these purposes, mineral wool or vermiculite is used. The first option is absolutely non-combustible, environmentally friendly material. However, vermiculite can withstand more heating of the chimney. Therefore, when arranging a heating system in a bath, it is better to choose pipes with this type of insulation.
Vermiculite withstands heating up to 1150 º, without losing its original qualities. Mineral wool chimneys can be used for systems in which heating does not exceed 600 º. On sale are designs that have ceramic wool between two layers of metal. This is the most heat resistant material. It is able to withstand temperatures up to 1250 º. The cost of the pipe largely depends on the type of materials and the application.
What to look for when choosing?
Insulated chimneys, sandwiches can be of different types. Therefore, when buying, it is extremely important to pay attention to the main characteristics of the products. They are indicated in the certificate, which is necessarily supplied in the kit. The characteristics must indicate the type of heating equipment for which a specific type of chimney is intended. The manufacturer must also indicate which types of fuel can be used for the boiler or furnace, so that the pipe can be installed in the system.
If the kit does not have a certificate, you cannot purchase such a pipe. This may not be safe. When buying, you also need to pay attention to the quality of the steel from which the product is made. The life of the product depends on its quality. In addition to stainless steel, chimneys can be used in the manufacture of chimneys. They are covered with a special protective layer. There should be no defects on it. Such materials can be used for equipment that creates heating in a gas exhaust system of about 500 º. The maximum temperature level for this equipment is only 750 º.
When choosing, be sure to pay attention to the type of insulation that was selected by the manufacturer. The operational characteristics of the equipment depend on this.
If a solid fuel boiler is installed in the house, the chimney must have a special seam. It is performed using laser welding. In this case, the inner pipe must be made of high quality stainless steel. If the boiler runs on gas fuel, the joints can be created using a different technique. Sheets are joined by skating.
The outer shell can be made of brass, polyester, galvanized or stainless steel.
The size
The diameter of the sandwich chimney inside and out may vary slightly. When buying, you must consider the size of the boiler nozzle. The chimney is installed in the outlet of the boiler. Therefore, these two elements of the gas exhaust system must be the same in size. Before you go to the store for the chimney, you need to consider the passport data of the boiler, the requirements for connecting and operating the equipment.
The internal diameter of the chimney may be different. There are very small designs. Their internal cross-section is only 110, 115 or 120 mm. For overall heating equipment, it will be necessary to purchase a chimney-sandwich of 150 mm, 200 mm or even 300 mm. The inner pipe is made of stainless steel sheet, which should be 0.5 or 1 mm thick.
The outer diameter may be 200-430 mm. It is important to pay attention to the type and thickness of the insulation layer. It can vary depending on the application of the pipe, as well as the type of material from 40 to 60 mm.
The length of the chimneys can also be different. The choice depends on the type of roof and the features of the heating system. There are pipes of 50 or 100 cm. If you need to rotate the pipe, use different adapters. They can have a 90º angle. Tees are sold with an angle of 135º or 90º. Also, various additional elements may be used in the system. They can have a diameter of 120, 150 or 200 mm. Such products include revision, fungus, adapter, weather vane, etc.
Connecting elements
Installation of a sandwich chimney involves the use of various additional structural elements. These shaped elements are designed to ensure the normal functioning of the system.
The convector allows you to divert combustion products, gases outside the building. Moreover, a knee may be present in the structure. It includes several parts. They are joined at the right angle. The use of this shaped element allows you to correctly configure the direction of the output of combustion products of the heater.
Very often in systems of this type tees are used. They are necessary for the quality removal of not only smoke, but also condensate. The most common element when installing a chimney is an adapter. It allows you to join different pipes.
The design should also include a revision. It is necessary for cleaning the interior of the chimney, conducting periodic inspections. Kagla allows you to adjust the draft of the boiler. If you want to decorate the chimney, a shaped element such as a rosette is used.
Weather vane, cone protect the pipe from natural precipitation. So that it does not get snow, rain, a fungus is used. It is made of galvanized steel.
Preparation for installation
Before you begin installing all the necessary structural elements, you need to consider in detail the technology of how to assemble a sandwich chimney. This type of chimney is characterized by high fire safety. Therefore, even a novice master can correctly assemble the system.
There are certain rules for installing the chimney. In the place where the pipe will pass next to flammable materials (roof truss system), you need to apply an additional layer of thermal insulation. It is also worth considering that the installation of such pipes cannot be performed directly above the heating device.
Mineral wool is used as thermal insulation. It does not burn, does not emit toxic substances into the environment. The size of this insulation should be between 30-60 mm.
The chimney can be mounted in accordance with one of two basic principles. Installation can be done by smoke or condensation. In the first case, the structure is assembled so that carbon monoxide does not enter the room. To do this, install tees.
The condensate-assembled system is designed according to the principle of flowing water down the pipe. It appears due to temperature differences. In this case, tees are not used. Experts say that it would be more correct to collect the outer part of the system by smoke, and the inner part by condensate.
Assembling a sandwich chimney with your own hands, you need to properly seal all joints. Leaks of combustion products should not be.
Chimney
Installing a sandwich chimney requires strict adherence to all rules and building codes. Installation of the system begins from the furnace. She is led to the roof. All sections are connected in stages. For this, clamps are used.
The first part of the system is mounted in stainless steel. In this case, the insulation layer is not applied. Under the influence of high heating, this material will simply burn. To improve the quality of joints, it is recommended to use a special heat-resistant sealant. In this case, the traction will be much better.
A novice master may have difficulty in conducting a chimney through roofing materials. This is a simple work that needs to be done in accordance with the recommendations of professional builders. First, an opening is cut out in the roof. In places where the roof materials will come into contact with the pipes of the chimney, lay a layer of mineral wool. After that, you can hold a chimney on the roof.
Carrying a chimney through the roof
Sandwich chimneys are installed in accordance with building regulations. Passing a chimney through the roofing material is also quite simple. It is necessary to make an opening on the inside of the roof. An inside sheet of galvanized steel must also be secured. Outside, you need to equip the roof. An apron will be welded to it.
The lower the pipe is located on the slope of the roof slope, the higher it should be. If the distance to the ridge is 1.5 m, the chimney should rise above it by 50 cm. If it is separated from this element of the roof at a distance of 3 m, the pipe should not be lower than the ridge.
It happens that the chimney needs to be located very far from the center of the roof. In this case, you need to draw a conditional line, which is drawn at an angle of 10º to the horizon line. The pipe should reach the edge of this strip.
Some expert advice
Sandwich chimneys should be installed taking into account the recommendations of specialists. They argue that it is impossible to join the pipes in the place where they pass through the ceiling. This is an important condition that should not be neglected. Where the pipe will go out, install a tee. Condensation will collect here. After the tee, the pipe rises.
Having considered the features of the sandwich chimneys, the rules for their selection and installation, it is possible to establish a high-quality system for removing combustion products from a heating device of any type.