Laying communications in a house or apartment is not as simple as it seems at first glance. In order for the equipment to work normally, and also there should be no complaints from the inspection authorities, it is necessary to carry out installation taking into account all the norms and rules, not forgetting the aesthetic component.
We will tell you how to correctly select the best pipes for hoods, focusing on their technical and practical qualities. Here you will learn how to choose the optimal section and calculate its size. Together we will understand the set of components from which the ventilation ducts are assembled.
For independent craftsmen, we offer two options for installing plastic ducts. The information presented for consideration is supplemented by diagrams, photo collections, video guides.
The use of ventilation pipes in the home
Ventilation pipes with a set of connecting and fastening elements are usually called air ducts. They are designed to ensure air circulation and are installed in those rooms where there is no access to the natural movement of air or there is an additional need for ventilation: in kitchens, in bathrooms, toilets.
Before the appearance of plastic parts on the market, air ducts were made of galvanized metal, and now they are often found in production shops or in catering establishments (their use is associated with high temperatures).
Image Gallery
Photo from
The construction of ducts from plastic pipes allows you to get rid of all the shortcomings of metal structures
For the installation of ventilation ducts, a full-fledged assortment of products is produced, providing the opportunity to assemble a system of any degree of complexity
Ventilation systems assembled from plastic are resistant to chemical, biological, mechanical influences
Plastic ventilation systems do not rust and do not oxidize in wet rooms, mold and fungus do not settle on their walls
The minus of PVC ducts is that they are not recommended to be placed next to heating equipment and installed in areas where direct sunlight is likely
Polymer pipes are characterized by high aerodynamic resistance, are used in the device and natural and forced ventilation systems
Plastic parts for the construction of air ducts are a priority in enterprises if high-quality removal of aggressive media is required
Polymer elements are excellent for ventilation in apartments and private houses due to their lightness, strength, and a service life of 50 years
Plastic duct option
Polypropylene elements
PVC ventilation parts
Valuable benefits of moisture resistance
Features of the use of PVC pipes
Aerodynamic drag
Production hood
Plastic ventilation duct
But for everyday use, that is, for installing ventilation in apartments and cottages, polymer products are more suitable.
They have the following advantages:
- have less weight than metal, so they are easier to install with your own hands;
- smooth walls have minimal resistance to air movement;
- tight because they have no seams;
- resistant to high humidity, do not rust;
- On sale you can always find a set of fittings that fit the cross section.
Products that meet GOSTs and have certificates of conformity are allowed for sale, so you can talk about the safety of plastic elements.
A stand in a supermarket with plastic elements for assembling the ventilation system for the hood: rectangular and round pipes, adapters, tees, plugs, corner pieces
Key Features of Plastic Parts
The properties of pipes must be known in order to properly design and install a ventilation system in an apartment or house. The characteristics of the elements may vary depending on the installation location (above the plasterboard ceiling, in the closet, in the attic) and the geometry of the room.
Consider which features are decisive when choosing.
Duct Material
On sale, you can find products for creating ventilation structures from four types of material, which in everyday life are called plastic:
- polyvinyl chloride;
- polypropylene;
- polyurethane;
- polyethylene.
Polyvinyl chloride. Lightweight, inexpensive, easy to install PVC ducts - the most common material for the construction of household ventilation structures. They are durable, airtight, but have some limitations.
They can not be heated to 160 ° C, since chlorine harmful to all living things begins to be released, and according to the standards, the upper heating bar without risk to human health is + 120 ° C.
PVC pipes are suitable for installation in the kitchen or in the bathroom, their use is prohibited where there is a possibility of heating to 160-180 ° C - for example, in saunas or in rooms with a fireplace
When the temperature drops below + 5 ° C, PVC becomes brittle, so for the installation of the ventilation system in rooms with temporary residence, it is better to choose a different type of pipe, for example, polyethylene or vinylurethane.
Polypropylene - excellent dielectric, non-hygroscopic, has high resistance to aggressive chemical environments. The tensile strength is about 4 times higher than that of high-pressure polyethylene products.
The main disadvantage is combustibility, the maximum possible temperature is + 85ºС. However, there is a fire-resistant variety with flame retardants - PPS.
Polyurethane in its characteristics resembles PVC, but can withstand higher temperatures - up to + 280ºС.
Particularly strong is a steel urethane reinforced vinyl urethane. It is suitable for drawing, as it has excellent resistance to mechanical damage and flexibility, allowing you to turn the duct at any angle
PND - low-pressure polyethylene. It does not crack with time and, unlike PVC, tolerates negative temperatures more easily (relevant for homes with temporary residence). Possible heat resistance - up to + 80ºС, cooling - up to -50ºС. Easy to process, like all types of plastic products.
Polypropylene and polyethylene pipes for household ventilation are rarely used, their PVC products are leading.
Image Gallery
Photo from
Conclusion of a fan riser to the street
Wall marking for installation of clamps
Installation of clamps in fixed anchors
Construction of a riser from sewer pipes
Types of pipes by degree of flexibility
There are two categories of ventilation plastic pipes for hoods - rigid and flexible. Sometimes a combined option is needed, but much less often. If the hood is installed next to the vent, there is no need for a complex design.
When purchasing rigid pipes of round or rectangular cross section, it is necessary to purchase a set of additional parts in order to make turns or transition points.
To assemble a short exhaust duct placed above the kitchen cabinet, rectangular PVC channels and connecting corner elements of the same material were used
Along with rigid straight pipes, corrugation is used - flexible products made of polyurethane or aluminum, which allow you to do without corner parts.
The use of an aluminum corrugated pipe as an air duct, which has two advantages over plastic analogues: fire resistance and higher strength
Corrugated products are more economical, but lose in design. To preserve the beautiful appearance of the interior, it is better to disguise them under suspended structures or place them in the “blind” zone - on cabinets against the wall.
Varieties of elements in sectional shape
Depending on the configuration of the pipe, air ducts of the following types are distinguished:
- round;
- rectangular;
- flat.
The shape of the cross section largely affects the technical characteristics and installation method. For example, direct round pipes They have better throughput and excellent sound insulation, since air moving along smooth walls practically does not encounter obstacles (with the exception of corner sectors).
However, installation problems may occur due to the cylindrical shape.
The option of installing a pipe of circular cross section leading from the hood to the ventilation hole on an adjacent wall. Mounting elements: 4 pipe sections, 3 90 ° round elbows, gear (+)
Rectangular ducts tightly fit to any flat surfaces (walls, ceiling, walls of kitchen cabinets), so it’s much easier to install them. But there is one drawback - the uneven distribution of air, due to which there is a lot of noise.
The optimal solution for installing ventilation over a suspended ceiling: lightweight rectangular plastic pipes with a set of adapters and an output round pipe (to reduce noise)
Flat ducts - these are the same rectangular, but having a large difference in the dimensions of the width and height of the cross-section (for example, flat channels 110 mm x 55 mm). Due to their compactness, they are often used for installation with a lack of free space (for example, over hanging structures or over highly suspended cabinets).
How to choose a section size?
The size of the cross section is more important than its shape, since the efficiency of air exchange in the room depends on this parameter. There are standards that take into account the specifics of different rooms, and when choosing ventilation elements it is better to focus on them.
Rooms with high humidity and a high content of dirt in the air (bathroom or kitchen) should be ventilated more often and more intensively than relatively clean and dry (bedroom, living room) (+)
According to SNiP, the volume of air flow in houses and apartments should be at least 3 m3/ hour at 1 m2 living space, while the number of people living is not taken into account.
The volume of circulating air for people who are constantly in the room - 60 m3/ h, temporarily located - 20 m3/ h (refers to places of work, for example, offices).
It is not possible to independently calculate the cross section independently, but there are simplified calculation methods. However, perfectionists are better off using the services of an engineer or a special program for which the following data will be needed:
- duct shape;
- pipe manufacturing material;
- internal resistance;
- indoor temperature.
There is a method that allows you to determine the size of the ventilation hole by the area of the room. For every square meter of the room there is 5.4 cm² of duct section, and the pollution factor is important.
For the exact choice of the pipe cross-section, we recommend contacting professionals who make calculations using complex formulas based on specific data.
What does exhaust ventilation consist of?
For the installation of air ducts, one pipe is not enough, shaped elements are needed - fittings for various purposes. They serve for tight connection of parts into a single system, provide smooth transitions of pipes of different diameters, connect the duct to the exhaust hood and ventilation hole, and allow you to create 90º angles.
Plastic fittings for assembling a rectangular duct: connecting and horizontal elbows, plugs, holders, grilles, gearboxes, straight connectors, plates, tees
One of the important elements is the transition (adapter). It is necessary in two cases: when you need to connect pipes of different cross-sections or ducts that differ in size.
They are used for assembling structures in rooms of complex geometry, sometimes for fragments built into cabinets.
In order to avoid the effect of backdraft and used air does not return to the room, the air ducts are equipped with a check valve.
This is a built-in frame with a dynamic blade that opens in only one direction - along the air flow into the ventilation shaft. The valve does not act as a connecting element, but as a part that increases the efficiency of ventilation.
The assembly of a small segment involves two pipe sections with a rectangular cross-section, a wall plate, a duct connector with an outlet, and an angular horizontal bend
To ensure absolute sealing, it is necessary to select fittings strictly according to the size of the pipes: for example, for boxes of 150 * 100 mm, elbows of the specified size are also necessary.
Plastic pipe mounting options
Consider two options for installing plastic pipes for exhaust ventilation. They differ both in the place of installation and in the choice of elements.
Image Gallery
Photo from
Assembly of turning sections
Arrangement of a hole for the hood
Installing a check valve flange
Assembly of straight duct sections
Installing part of the duct from the hood
Installation of the second part of the duct
Extractor Power Connection
System Testing at Completion
Option 1. Indoor duct installation
Most often, plastic pipes for arranging ventilation are used in the kitchen to connect the hood and the ventilation hole located on the wall under the ceiling. To facilitate operation, the hob must be positioned as close as possible to the outlet.
If it is installed on the opposite side, it is better to move it closer than to pull the duct through the entire kitchen.
The shorter the overall pipe length, the better. It is estimated that each rotation of the pipe with an angle of 90º reduces the efficiency by 10%, and that systems that are longer than 3 meters lose as much for every extra meter.
In order to avoid questions during the work, we make preliminary calculations and draw up a drawing indicating the dimensions and additional parts of the duct.
As a sample, we take the often-encountered option, when the exhaust outlet is located slightly to the side of the hood
To work, you will need:
- flat channel for exhaust ventilation 204 * 60 (1.5-2 m);
- horizontal knee 204 * 60
- connecting knee;
- wall plate;
- round gearbox with adapter;
- plastic hacksaw;
- sandpaper;
- sealant;
- marking tool.
We prepare the pipes - we cut the blanks of the desired length from the plastic boxes, we clean the edges. If the duct is mounted in free space, you can pre-assemble it on the floor, fixing the connecting elements with a sealant.
If part of the structure will be in the cabinet, first we fix it (gearbox + vertical pipe), then connect it to the horizontal pipe with an angular bend.
At the end, we connect the pipe to the hole decorated with the plate with a special fitting. For strength, we anoint the joints with sealant, heating can not be used.
False ceiling structures or wall cabinets are used to mask the duct. For open space, it is better to choose flat rectangular boxes that become invisible if placed on cabinets (+)
If mounting to a wall or ceiling is necessary, self-tapping screws cannot be used. For this purpose, clamps are tightly provided to tightly enclose the pipe. They are equipped with a rubber seal and are attached using brackets or studs. Some clamps are fixed by a simple snap-on, which simplifies the installation process.
Having chosen a suspended ceiling as a masking structure, try to conduct quality work. Before starting construction, carefully check the air tightness of the duct - for repair or replacement, you will have to disassemble the ceiling structure made of plastic panels or drywall.
Not only plastic products are used in the construction of ventilation ducts. You will learn about the choice of material for the installation of air ducts from the popular article on our site.
Option # 2. Thermal insulation of pipes in the attic
In a city apartment, the installation of exhaust ventilation is reduced to the installation of plastic ducts leading to the openings in the communal mine. In a private house, it does not end there, since there is another section - from the heated room through the attic to the street.
So that condensation does not occur on the plastic pipes from the cold (the attic is often not heated), warming is performed.
The best materials for thermal insulation are:
- basalt cotton wool (glass wool, mineral wool);
- shell made of polymeric materials - polystyrene or polystyrene;
- foamed polyethylene.
An example of basalt wool is Rockwool coiled mineral wool, non-combustible and tear-resistant, with a minimum breathability of 0.3 mg / m × h × Pa, a wide range of heat resistance (from - 180 ºС to + 500 ºС), hygroscopicity of about 1.5% by volume . Service life - up to 35 years.
In addition to rolled basalt wool, there are other varieties of Rockwool insulation: thick mats or plates, coiled cylinders with foil coating
Soft rolls are wrapped around the pipes with an overlap, covered with foil or roofing material on top (if mats without waterproofing are used), fixed with a metallic tape or steel wire by winding.
Polyfoam and expanded polystyrene look like rigid tubes consisting of several segments. Some of them are covered with a layer of foil. The foam has a looser structure, so it is suitable for warming curved fragments. Due to the low price it is preferred by frugal owners.
The table shows the comparative characteristics of the shells of PPS, which are made of PSB-S foam and look like half cylinders, fastened with clamps or bandage (+)
The leading position is held by foamed polyethylene Penofol, more elastic than the listed materials. The insulation is notable for its minimum thickness, but it does not allow moisture to pass through (it is covered with waterproofing foil on one or two sides), provides a low noise level and perfectly retains heat.
For independent insulation, we recommend using Penofol C roll. The secret to easy installation is contained in its structure: thin and light polyethylene is covered with an adhesive layer on one side and a waterproofing foil on the other.
The thickness of the insulation is different - from 3 mm to 10 mm, the coefficient of thermal conductivity in the range of 0.038-0.051 W / (m * K), water absorption - up to 0.35%. For installation, it is enough to cut the material into pieces of the desired size, remove the protective film and stick it on the pipe fragment.
For straight pipes, large in length, you can use a roll over the entire width, without cutting.
Particular attention should be paid to the joints, the area of the outlet of the duct to the roof, places of contact with the outer walls.
Informative videos will help you understand the types of plastic pipes and learn more about how to install them.
Video # 1. Installation of a plastic box:
Video # 2. Installation procedure in a drywall box:
Video # 3. Thermal insulation of ventilation pipes in the garage:
As you can see, the installation of plastic ducts is not difficult and is suitable for independent work. However, when designing a project, we recommend contacting professionals who know the nuances of the supply and exhaust ventilation installation and are able to accurately calculate the dimensions of the elements used.
If you have any questions while familiarizing yourself with the information presented by us, please write comments in the box below. Here you can talk about your own experience in installing ducts and share useful information.