Sandwich pipe for ventilation: installation instructions and the nuances of assembling ventilation from a sandwich pipe

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Elena Cherkasova
Last update: January 2020

“Ventilation plays an important role in the planning of small private houses, high-rise buildings, industrial, industrial, office buildings and institutions. First of all, human health depends on the proper organization of room ventilation. Therefore, the correct choice of ventilation pipes when installing ventilation systems is of great importance.

One of the popular materials for arranging external ventilation ducts is a sandwich pipe for ventilation. But what is it and how to properly install the system from such pipes?

This is what we will discuss in detail in this article - we will consider in detail issues related to the use and installation of sandwich pipes in the arrangement of ventilation.

Design and use of sandwiches

For the organization of natural mechanical extraction, it is necessary that the ducts meet a number of requirements.

The main ones are:

  • ensuring the tightness of the ventilation system;
  • the ability to maintain the necessary air pressure in the system;
  • ensuring free passage of air inside the ventilation system;
  • maintaining the necessary thermal insulation.

To ensure compliance with the requirements, depending on climatic conditions, type and purpose of buildings, different types of ventilation pipes.

Insulation layer in the sandwich pipe
The thickness of the insulation layer depends on the required operating temperature inside the ventilation system. Also, the diameter and dimensions of the pipes used affect the thickness of the insulation.

A pipe sandwich is used not only for the installation of ventilation, but also for:

  • private homes where it is used as chimney - to remove air masses from heating devices (stoves, fireplaces, boilers);
  • multi-family residential buildings in the northern regions of the country;
  • buildings of production within which work with high heat transfer is carried out (workshops for the melting of metals, workshops for the production of glass);
  • grain storage buildings.

The necessary properties are acquired by products due to the special technology by which the pipe sandwich is made. Also, due to their design, the feature of which will be discussed below, these pipes are suitable for connecting heating equipment to them. In this case, they are used as chimneys to remove smoke from the room.

By design, “sandwiches” consist of two pipes of different diameters made of high alloy stainless steel sheets. Interconnection is made using argon welding. The space formed between the two pipes is filled with a special heat-insulating material, often made on the basis of basalt, with a width of 25 to 60 millimeters.

Such a device allows to maintain the temperature of the exhaust air inside the pipe without cooling it prematurely. Thus, the normal draft of air exhaust from the room is maintained.

It is worth noting that basalt wool, used for insulation of sandwich pipes, can withstand temperatures up to 1115 ° C. At the same time, it is a non-combustible substance and melts when a high temperature is reached. Therefore, it is not surprising that “sandwiches” are so popular in the construction of chimneys.

Pipes of various diameters
Currently, the market has a fairly large selection of sandwich pipes of various diameters. The uniqueness of their assembly lies in the possibility of laying pipes through inaccessible passages and the ability to interconnect a sandwich pipe of various diameters

Depending on the conditions in which the sandwich pipe will be operated, a different thickness of insulation is chosen.

Sandwich pipes can also be made using steel sheets made of heat-resistant steel, which is especially important for use in places with high temperatures of air masses.

Pros and Cons of Sandwich Tubes

Among the advantages of ventilation sandwich pipes, one can distinguish:

  • light weight construction - during installation, it will be enough to use the main fasteners, without involving the supporting elements;
  • dimensionswhich are not significant and allow you to save more space when placing the ventilation system indoors;
  • universality in places of application - can be used both indoors and outside;
  • easy assembly, which allows, if necessary, to give the ventilation system various forms, depending on the layout of the building;
  • lack of condensate and the possibility of its appearance inside the system - it is realized thanks to the insulation and assembly features;
  • holds heat exhaust air inside the structure;
  • is fire safe in use;
  • the use of stainless steel smoothes the effect of the environment, preventing the appearance of rust and, as a consequence, partial destruction with violation of the sealing of the ventilation system;
  • no need to set the foundation when installing a sandwich pipe.

Another advantage of a sandwich pipe is its reasonable cost. The price of 1 meter ranges from 970 - 2900 rubles.

Using a sandwich pipe
The use of a sandwich pipe as a chimney for the output of combustion products is considered one of the main areas of application. It is this design that allows you to create and maintain the necessary traction power to remove waste resulting from combustion

Experts attribute only one to the minuses of using a sandwich pipe - this is the need to replace elements every 10 years.

This is due to the short service life of this type of pipe, which directly depends on:

  • timelycleaning the ventilation system or chimney (depending on the scope of use);
  • observance of accuracy during installation;
  • properly selected equipment for which the hood is mounted;
  • lack of defects and defects in production.

The service life of a sandwich pipe is designed for 10 years with proper operation, therefore, bypassing the ten-year threshold, the pipeline made of such pipes should be completely replaced.

What to look for when choosing?

When choosing components for installing a ventilation system from a sandwich pipe, one should be guided by the following characteristics:

  • strength of the material of manufacture;
  • degree of filling and thickness of thermal insulation;
  • quality of welds.

From material strength directly depends on the service life of the ventilation, as well as the chimney system. In the second case, the thermal insulation filler material must at least withstand temperatures up to 700 ° C.

Strongly advised not to choose fiberglass as a filler.

Conclusion of a sandwich pipe to the roof
In order to carry out a ventilation system mounted from a sandwich pipe, the following components are additionally required: adapters and tees, devices for organizing the passage of pipes through walls and roof, clamps for fastening, brackets

Weldingproviding the maximum tightness, - laser. It is even suitable for using sandwich pipes as a chimney in a solid fuel heating system.

From degree of filling with special heat-insulating material further application of the sandwich pipe depends.

So, with an average thickness and density of filling, a sandwich pipe can be used as ventilation in:

  • multi-family and private houses;
  • administrative buildings;
  • in crowded places (supermarkets, cinemas, gyms, etc.)

For use in factories, pipes with a high filling density with insulating material should be used. Even to create a ventilation system in private small plants, the filling density should be maximum.

It is worth noting that behind the Arctic Circle, sandwich pipes with a maximum degree of filling and the thickness of the heat-insulating element are used to ensure ventilation of residential buildings.

The order and nuances of installing "sandwiches"

Installation of ventilation from “sandwiches” allows without special difficulties to organize thermal insulation protection of sections of the ventilation pipe passing through uninsulated sections, as well as in the immediate vicinity of the ceilings.

Assembly instructions for ventilation assembly

First of all, before starting work, it is necessary to perform all the calculations, taking into account the structural features of the building.

After the calculations, the required number of components is acquired and already after they are delivered, you can start assembling.

Sandwich pipe section
Before starting installation work, it is necessary to determine the size of the cross section of the sandwich pipe. What will directly determine the efficiency of air exchange in the room

Each set of pipes is accompanied by instructions, using which you can correctly mount the ventilation system.

For proper installation of a sandwich pipe for arranging the hood, it is enough to have minimal construction skills. Since the product has a father-mother design, the joints are freely connected to each other.

To ensure sealing at the joints are used gasketswhich can withstand high temperatures (up to 300 ° C).

Installation of sandwich pipes
The type of connection “father-mother” is a slang designation that originated in the middle of the 20th century in factories. For ease of understanding, the workers designated this expression as the possibility of combining two elements. In this case, in the photo, the lower sandwich pipe will be considered “mom”, and the upper - “dad”

When conducting a ventilation system through the walls, it is worth considering the following requirements, which are prescribed in SNiP 41-01-2003:

  • pipes should not penetrate the supporting structures, the distance from them should be at least 1 meter;
  • in brick walls, the requirements for gaps to ensure thermal expansion are 1 cm.The gap should be filled with basalt wool;
  • passage through the wall is recommended to be mounted with a special passage assembly.

The requirement for the pipe to pass through the ceiling is similar to those presented when passing through walls. You can add to them - insulation with basalt insulation.

Pipe outlet to the roof
The need to create a small space between the pipe surface and the wall surface is due to the fact that during operation the pipe diameter can change (metal “plays” depending on the temperature of the air discharged by the ventilation system). To avoid mechanical damage, free space is required, which must be clogged with soft, heat-resistant material.

When organizing the passage of a sandwich pipe through the roof, be sure to observe the following recommendations:

  • provide for a special fastening of the pipe head to the roof;
  • organize the sealing of the passage unit with heat-resistant rubber;
  • Be sure to use a deflector to increase traction.

It is necessary to mount the passage of the pipe through the roof with the obligatory use of the factory passage node. Otherwise, the exhaust properties during the evacuation of air from the premises will not be fully ensured.

Rules and Tips

The basic rules for installing ventilation from “sandwiches” practically do not differ from the assembly of a ventilation system from other types of pipes:

  1. For safety from destruction caused by the temperature difference, it is necessary to place ventilation pipes for the most part inside the building. The output of the pipe can be carried out both on the roof of the building and through the wall. In the first case, such an organization of output allows more effective elimination of possible odors.
  2. It is forbidden to conduct ventilation pipes in the immediate vicinity of equipment emitting abundant heat fluxes. External heating of the sandwich pipes of the ventilation system will disrupt internal draft, interfering with the movement of air masses.
  3. The construction of the ventilation structure should begin from the bottom, gradually moving upward, so that each subsequent element of the system is included in the previous one.

Be sure to equip the ventilation duct deflector - This is a special device that allows you to strengthen the draft of the flow of exhaust air, thereby providing a more powerful cross-country air mass. He also protects from getting into the ventilation of garbage and rain.

It is possible to plant a protective cone, which will also prevent the ingress of rainfall into the system.

Roof pipe sandwich
The height of the exit sandwich pipe through the roof. The lift height of the ventilation pipe provides normal traction for air circulation. Depending on the length of the system indoors, the height can be from 50 cm to 3 m

In addition to the above, when installing a sandwich ventilation, you need:

  • use components that meet factory standards, since a sandwich made by yourself, will not have the same thermal characteristics;
  • exclude the installation of “home-made” adapters or tees when assembling the ventilation system;
  • to give greater strength to the joints, it is necessary to install tightening clamps at the joint for each of the connected pipes;
  • most often, a sandwich pipe is mounted in a section passing in the attic or in other unheated rooms;
  • it is forbidden to seal the joints with sealant, as this can lead to thinning and further destruction of the gasket itself.

This set of measures, together with a clear implementation of the instructions will allow not only correctly, but also reliably assemble the ventilation system from the sandwich pipes.

Correct installation and compliance with the above conditions allows you to use a sandwich pipe for at least the manufacturer's lifetime.

Conclusions and useful video on the topic

To visually demonstrate how the sandwich pipes for the ventilation system and for the chimney differ, you can watch this video:

Features of the installation of ventilation on their own are considered in the following video:

Using a sandwich pipe for ventilation is the best solution for both industrial enterprises and small private houses. Simplicity in assembly and simple requirements allow you to independently install such a ventilation system.

Subject to safety regulations, assembly instructions and the above tips, the assembled system will be quite effective in operation throughout the entire period of operation.

If during reading the article you still have questions or have questions, or want to supplement the material with useful information, your own experience in installing a ventilation system from sandwiches, you can voice them in the comments in a special section below.

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