How and how to insulate the ventilation pipe: rules and regulations for insulation of ducts

Author: Tatyana Zakharova
Last update: December 2019

Ventilation refers to communications, the installation of which is planned at the stage of creating a project for the construction of a private house. This is justified by basic hygiene requirements. Without proper air exchange, comfortable living is simply not possible.

We will tell you how to insulate the ventilation pipe to ensure its normal operation in the winter. From the article presented by us you will find out which heat-insulating materials meet modern requirements. Understand how to choose the best option for insulation.

Interested home craftsmen will find brief instructions on how to install a heat-insulating barrier. Those who decide to independently heat the hood will receive proven information in practice. Compliance with our recommendations is a guarantee of a successful result.

Purpose of thermal insulation of air ducts

The arrangement of ventilation ducts and air ducts is subject to technical rules that dictate the choice of pipes, their placement, connection methods and mandatory thermal insulation if communications pass through unheated sections.

Ventilation pipes pass through the entire space of the house: begin in the basement, which is often used as a technical or utility room, and end above the roof.

Not all rooms in the house are heated. Often a low temperature is set in the basement and in the attic, which causes problems, the main of which are heat loss and condensation.

The scheme of ventilation in a private house
The ventilation scheme in a private house. If you neglect the thermal insulation of the attic and the roof, you will have to make more efforts to warm the air ducts located under the roof

Rules for arranging ventilation are set out in SNiP 41-01-2003. There you can find information about heating and air conditioning in general.

Thermal insulation of household ventilation ducts performs 4 functions:

Each of these functions is very important. For example, condensation can create big problems for home owners. Moisture formed on the outer walls of the pipes causes corrosion of the metal and in a short time can lead to the complete replacement of some ventilation sections. Mold forms on the attic walls, destroying the wood, an unpleasant odor is established.

Internal condensation is no less dangerous. Moisture seeps through the walls of the pipes into the living quarters and also causes negative consequences: it increases the general humidity level, causes deformation of wooden furniture and decoration, the appearance of fungus and mold, and the residents feel unwell.

The graph of the coefficient of thermal conductivity
A graph showing the dependence of the coefficient of thermal conductivity of modern heaters for ventilation on air temperature in unheated and residential premises

And the temperature drop in the bedrooms, and extraneous noises that interfere with sleep - all this is the result of chilled ventilation pipes. If you are familiar with these problems, then you can deal with them yourself by warming the air ducts. And first you need to choose the right insulation material.

Material Specifications

In order for the insulation to last for a long time, not to become damp ahead of time, not to become moldy and to fulfill all the tasks assigned to it, it must possess the following qualities.

One of the most important characteristics is coefficient of thermal conductivityexpressed in W / m • ° С. The degree of air cooling in the pipes depends on it. Manufacturers, given the differing installation conditions, produce heat-insulating materials of various thicknesses and densities.

Characteristics of thermal insulation materials for ventilation
The table shows the popular building materials used for thermal insulation of air ducts. Using the above data, we can determine the dependence of the thermal conductivity on the density and thickness of the material

The second important parameter is vapor permeability. If air ducts are prone to condensation, it first penetrates the insulation and increases its moisture content, which increases thermal conductivity.

Plastic film for ventilation pipes
If for insulation you have chosen porous, fibrous materials that easily absorb moisture, take care of additional vapor barrier. The simplest option is to wrap the insulated area with plastic wrap

The next characteristic is acoustic performance. Air moves inside the channels, causing vibrations and noise. A running fan also generates sound waves. They are transmitted through the air and the rigid structure of the duct into the surrounding space and create discomfort for the residents of the house.

To minimize noise, you need to consider the design features of the ducts, make them straight, with a minimum number of turns. Significantly reduce noise can also be with the help of a sound-absorbing insulation.

Do not lose sight of such a quality as biological resistance. The less material is suitable for the formation of colonies of molds, the reproduction of various microorganisms, the longer it will last, and with it the structure of other building materials, such as wood or concrete, will be preserved.

Attic living room
Mold causes not only the destruction of natural materials, but also negatively affects the well-being. If you plan to place a living room in the attic, ensure a normal temperature and humidity level.

For a thermal insulation material, an important parameter such as working temperature. It differs in different heaters, but the range from -35 ° С to + 60 ° С can be called average.

And one more characteristic - sanitary and hygienic properties. Thermal insulation should not spread toxic, harmful gases. From this point of view, materials containing components of natural origin — for example, felt or mineral wool — are valued.

Overview of the best modern heaters

All kinds of heat-insulating materials are presented on the Russian market, ranging from polystyrene foam and glass wool, which are used less and less, ending with convenient spraying solutions.

Selection of materials for ventilation ventilation in the attic It is built taking into account specific environmental conditions, installation nuances and financial capabilities.

Consider how to insulate home exhaust pipes running in cold rooms. We offer four thermal insulation options that are suitable for independent use. Their characteristics comply with the requirements and standards, and even a beginner in the construction business will cope with the installation.

Option # 1 - mineral wool

Mineral wool includes completely different categories of insulation made from glass, basalt, and slag fibers. Glass wool is considered the least effective and cheapest material, which, with many advantages, has no less drawbacks.

Glass wool as insulation
Glass wool has excellent sound-absorbing and heat-insulating properties, relative strength and fire safety - operating temperature up to + 450 ° С. It is resilient, easy to install

But, unfortunately, this budget option may include harmful phenol-formaldehyde resins, is extremely hygroscopic, requires vapor barrier, and after 3-4 years the thermal insulation function is lost by about 50%.

Due to flaws, glass wool is a thing of the past, and basalt or stone wool took its place. It is presented in two mounting solutions: in the form of mats (thinner - rolls) and shells, often foil.

The shell is more suitable for warming pipes of small diameter, ventilation ducts in the attic are often wrapped with rolled mineral wool.

Basalt cotton wool in a roll
Strength, high resistance to biological influences and lower hygroscopicity of basalt wool are explained by the fact that it is made from molten rocks

Benefits:

  • non-combustible, fire-resistant material, operating temperature - up to + 1000 ° С;
  • thermal insulation coefficient - on average up to 0.038 W / m • ° С;
  • long service life;
  • minimal deformation.

Disadvantages:

  • inexpensive varieties may contain harmful binders;
  • higher than glass wool cost.

The mounting method of cylinders and roll products is different. Cylinders or shells consist of 2 parts, which are fastened with a lock connection. To strengthen the fixation, the seams are glued with construction tape.

Foil shell for pipes
To increase the heat and vapor barrier properties, a foil shell is produced. We recommend using this type of mineral wool for rooms with high humidity - attics and cold basements

Basalt wool in the form of mats or rolls is mounted differently.

Operating procedure:

  • Measure the pipe section requiring insulation.
  • Cut off a piece of thermal insulation that is suitable in size.
  • Wrap the pipe with mineral wool with an overlap, like a blanket.If the insulation is thin, you can wrap in several layers.
  • Fix the “blanket” with construction tape, wrapping the pipe with a spiral along the entire length. Instead of tape, you can use annealed wire.

For ventilation ducts of rectangular cross section, another method is used: “put” mats or plates on special glue.

Option # 2 - Foamed Polyethylene

This material is so good that many manufacturers are engaged in its release. Heater can be found under the brands "Izolon", "Penolon", "Tepofol". Foamed polyethylene is somewhat reminiscent of foam rubber, but differs in large cells and technical characteristics.

You can find various varieties, among which - foil, covered with a layer of aluminum foil. Its advantages are maximum protection against moisture, heat preservation.

Foiled foamed polyethylene Penofol
An example of foil foamed polyethylene is Penofol. Foiling is done on one or both sides - in the second case, the reflectivity of the insulating material increases

Depending on the grade and thickness, the material has a thermal conductivity coefficient of 0.031-0.051 W / m • ° С, working temperature - from -65 ° С to + 100 ° С, water absorption up to 1%, operation life - 10 years.

Benefits:

  • strength and wear resistance;
  • elasticity, ease of installation;
  • resistance to chemical and biological influences;
  • light weight;
  • the possibility of repeated use.

Disadvantages:

  • combustibility class - 2G, melting occurs at a temperature above + 100 ° С;
  • high degree of smoke formation - D3;
  • environmentally harmful, decomposes in vivo 200 years.

We recommend the use of cross-linked polyethylene, which differs from non-cross-linked polyethylene by superior technical characteristics. According to European requirements, the use of non-crosslinked (gas-foamed) varieties is prohibited.

The insulation is installed according to the instructions and practically does not differ from the installation of other rolled materials.

Option # 3 - Styrofoam and Styrofoam

Many are familiar with polystyrene - it is still used in packaging of household appliances to prevent breakdowns during transportation. This is a polymer foamed mass, very light due to the large amount of gas in the cells.

Foam shell for pipes
The foam is rigid, therefore, it looks like plates of various thicknesses or shells of 2 or 3 sections. During installation, parts of the shell are connected by a thorn-groove lock

Expanded polystyrene - extruded polystyrene, in the production of which the same starting materials are used as for the production of foam. It has improved performance and is more expensive. The difference between these two materials can be seen in the table:

StyrofoamExpanded polystyrene
Heat conductivity coefficient, W / m • ° С0,032-0,0500,028-0,034
Water absorption,% / day4/304/30
Bending Strength, kgf / m²0,07-0,200,40-1,00
Working temperature ° C-50 … +75-50 … +75
Service life, years2550

Expanded polystyrene will retain heat better and serve longer, moreover, it is used for the production of convenient covers for round pipes.

Benefits:

  • light weight;
  • resistance to biological effects;
  • low cost.

Disadvantages:

  • combustibility class - G3 / G4;
  • unhealthy smoke;
  • the ability to isolate only round pipes.

When installing the shell from extruded polystyrene foam you need to know some of the "oddities" of the material, especially when using glue. Polyfoam melts from ordinary adhesive solutions, so for additional fixation you need to purchase a special glue. As an option, use tape or a polymeric mounting tape.

Option # 4 - sprayed polyurethane foam

If previously sprayed materials for insulation of pipelines and other structures were used only in industry, now they are actively used in private housing construction, for example, for thermal insulation of air ducts.

Polyurethane foam for pipes in a spray can
Polyurethane foam for domestic use is sold in small spray cans.Spraying is done using the nozzle, while you can adjust the horizontal or vertical direction

The thermal conductivity of the material is 0.019-0.04 W / m • ° C, the combustibility is G1, and the service life is about 20 years. The boundaries of operating temperatures are wide - -160 ° ... + 150 ° C.

Benefits:

  • maximum fit of the insulation to the ducts;
  • lack of seams and "bridges of cold";
  • thermal insulation of structures of even the most complex configuration;
  • high speed application.

Disadvantages:

  • high price;
  • spray skills needed;
  • during installation, protection is required - overalls, glasses, a respirator.

Special preparation of pipe material is not required. Insulation in the form of foam can be applied both to individual pipes in advance, before their installation, and to the finished structure.

Drawing polyurethane foam on a pipe
Foam hardens quickly enough, so try to make movements carefully. The insulation layer should be uniform, evenly distributed, without thickenings and “bald spots”

Operating procedure:

  • Wear protective clothing, face shield and goggles.
  • Fasten the holder to the cylinder, insert the nozzle.
  • Turn the nozzle to the desired position - for horizontal / vertical application of insulation.
  • To apply foam on open sections of the pipeline, using movements up / down, left / right, etc.
  • Check to see if there is any “receding hairline”.

As a result of proper spraying, a dense, durable polymer layer should appear on the surface of the pipes.

In addition to the materials listed, foamed synthetic rubber and PIR boards are used to warm the ventilation ducts. Insulated pipes are also bought - but this is less common and is mostly practiced at industrial facilities.

We add that modern materials for thermal insulation of air ducts are safe and completely ready for use. But to make sure that the product is certified and meets the safety requirements, still does not hurt.

Conclusions and useful video on the topic

Experience attaching plastic pipes in the attic:

Application of sprayed polynor insulation:

How is the installation of a self-adhesive insulation Isolon:

Now you know how you can independently insulate ventilation in a private house and what materials are suitable for all standards. But do not forget that the right choice of material will not solve all the problems: you need to correctly and without errors install the thermal insulation.

Before work, we recommend that you make sure that the ventilation system is operating at full capacity, is not dirty, does not require repairs or alterations. If troubles occur due to errors in the installation of pipes, no insulation will help.

Do you have information on the topic of the article, which is worth sharing with visitors to the site? Does your arsenal have technological subtleties known only to you? Write comments, please, in the block below, ask questions and publish photos.

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