When the layouts of buildings and various institutions, as well as individual buildings are being developed, one of the most important design directions remains the creation of proper ventilation.
To install the ventilation system, it is necessary that the ventilation pipe is selected correctly. For this, the following parameters must be taken into account:
- dimensions;
- material of manufacture;
- terms of Use.
The industry produces several types of air ducts:
- round;
- rectangular.
The ventilation pipe is installed in the supply system and with an exhaust hood, when a forced and natural type of draft is created.
An important point when purchasing products is the diameter of the ventilation pipe. Today, 22 diameters of round products are standardized. Diameters are in the range 100–2000 mm.
If a outer dimension products exceed 500 mm, it is considered particularly large. The regulations allow the construction of straight highways starting from 2.5 meters. The total length of the straight section should not exceed 6 meters.
Ventilation pipes are manufactured from a whole sheet of metal. The longitudinal seam is formed by the spiral-wound method, when a steel tape, the so-called strips, is wound.
The cost of a round duct is always less than the cost of rectangular products, since their weight is much less.
The rectangular exhaust pipe is available in several standard sizes:
- 100x150 mm;
- 1600x2000 mm.
All products have a 50 mm pitch. Trunk sections are allowed to be made straight, but not exceeding 2.5 meters. In order to connect different sections of the duct in places of turns and bends, the industry produces fittings for ventilation systems with specific diameters and various shapes.
Such rectangular ducts are made of sheet steel, and the sheets can be galvanized or rough. For assembly, metal corners obtained by stamping are also used.
A very important advantage of such a rectangular design is considered to be the ability to change the configuration of the tubes without affecting their throughput. This makes it possible to mount ventilation in buildings with very low ceilings or in other particularly difficult conditions.
The shape of such a product, its cross-section are in direct proportion to the type of room and its dimensions. If the room has a small area and rather low ceilings, flat ventilation pipes for a rectangular hood are considered more acceptable.
Of course, the aerodynamic characteristics of round products are much higher than rectangular ones. But the available areas dictate their own terms. In rectangular pipes, corners become a source of resistance. They are the cause of a lot of noise, because of them, the air flow rate drops. To extinguish all these negative phenomena, ventilation from rectangular pipes must be insulated.
When industrial ventilation is installed, only circular cross-section products are installed, which have a high throughput.
Plastic ventilation pipes
The main materials for the manufacture of ventilation pipes are steel and plastic. These materials, as it were, form an unspoken competition with each other.
Which products are more suitable for the ventilation system, galvanized steel or ordinary plastic? To answer this question, it is necessary to take into account the requirements of the project, to consider in detail the nuances of the surrounding atmosphere.
The following materials are used for the manufacture of plastic pipes:
- polypropylene;
- fluoroplastic;
- polyurethane.
In small rooms and individual cottages, ventilation made of PVC pipes is most often installed. They are inexpensive, easy to install and maintain. Such ventilation ducts are not affected by ultraviolet rays and are able to withstand wide temperature variations. The range is 0-80 degrees.
Advantages of PVC ventilation pipes
- perfect tightness;
- aerodynamic noise complies with sanitary standards;
- the cost of such products is much lower than their metal counterparts;
- the appearance goes well with the interior of the room;
- issued various shapes and dimensions. Easily fit into any system;
- thanks to the large number of additional plastic parts, it is possible to assemble an air duct of any shape;
- completely safe for the human body;
- there is no release of toxic substances.
Polyethylene pipes intended for installation of a ventilation system are made with special anti-static protection. They can operate between 40 and 80 degrees.
PVC pipes, which contain black soot, are reliably protected from ultraviolet rays. They differ from ordinary products in their black color.
Products made of polypropylene do not react to the effects of an aggressive environment, they are not afraid of high humidity, they are able to work at temperatures from 1 to 98 degrees.
In areas with special conditions, special non-flammable and antistatic products are used. When the temperature drops, the material of the product becomes very brittle and brittle. It can only be used in heated rooms.
The most resistant to aggressive media are fluoroplastic tubes. They are installed on any type of ventilation. This material is able to function normally at 40-140 degrees. Such properties made it possible to install this ventilation for strong air currents, which contain a large amount of aggressive substances.
All of the above benefits made plastic pipes quite popular in individual housing construction. Only low fire resistance does not allow installation PVC pipes in large industrial plants.
Steel
They are made from a wide variety of metals and alloys:
- sheet galvanized. Usually the thickness is taken in the range of 0.5–1.2 mm;
- stainless steel AISI 304, 321, 316, 430. Maximum thickness 5 millimeters;
- aluminum;
- galvanized steel;
- thin sheet.
For the manufacture of vent pipes, sheet aluminum is very rarely used, mainly foil is used. Ventilation pipes with a diameter of less than 50 cm and a thickness of about 0.55 mm are made of tin. For large diameters, metal sheets with a thickness of more than 0.7 mm are taken.
Advantages of Rigid Steel Pipes
- Long service life.
- High strength.
- Excellent aerodynamics thanks to a perfectly smooth inner surface.
- Rarely clogged.
- They work at high temperatures.
- Withstand a lot of pressure.
- They meet all hygienic requirements, therefore they are installed in areas where high sanitary requirements must be observed.
- Neutral to aggressive substances.
Comparative characteristics of ventilation pipes
Galvanized. GOST allows the installation of galvanized pipes in any climatic conditions. They can be in any ventilation. The only exception constitute only transportation systems for aggressive mixtures, for example, gas.
They are reliably protected from corrosion by a thick zinc layer. When it comes into contact with oxygen, a protective film is formed that covers the entire pipe surface.
Stainless steel. These products are specially made for ducts carrying aggressive air currents such as hot steam or gas.
Stainless models are able to withstand very high temperatures. The service life of such structures is measured in tens of years. They are most often installed in large industrial plants.
To increase fire safety, products are covered with mineral wool.
Black metal. Such ventilation pipes are installed to ventilate the room and remove flammable gases. They are distinguished from analogues by their high fire resistance. The rigidity of the pipes is much higher than galvanized and stainless steel. Welded seams give high tightness.
Characteristics:
- Manufactured from low carbon steel;
- Wall thickness 1.2–1.5 mm;
- The total length of the pipe ranges from 125 to 250 cm;
- Docking can be done flanged.
Corrugated
They are used to create a flexible duct. The main advantages of such products are:
The corrugated pipe can be easily bent regardless of its section. Therefore, it is used in rooms of complex configuration, where it is impossible to lay other types of pipes.
It comes in several forms:
- galvanized;
- aluminum.
Distinctive properties are given to each type of pipe by the material of manufacture. The flexible duct is widely used in industry and individual construction. It is very easy to install it yourself.
Polyester fabric
The advantages of such ventilation pipes include:
- light weight;
- easy transportation;
- simple installation.
This kind of ventilation is lightweight, so there is no need to install special brackets for mounting to the wall. The pipes are connected with an ordinary zipper sewn into the end of each section.
Condensation never appears in fabrics. Therefore, they do not require insulation.
From the above, it becomes clear that all types of products are very different from each other. Each of them has its own positive and negative characteristics. But they are united only by a variety of sizes:
- round and plastic - 32-1250 mm;
- metal - 50–1500 mm;
Sewer
Considering specifications sewer and plastic pipes, you can find a lot of similarities. Consumers often ask: is it possible to independently build ventilation using sewer pipes? Will a positive result be achieved?
It is difficult to answer unequivocally to such a question. This decision can only be made by the owners of the premises.
The most difficult thing when laying such ventilation will be the mismatch of the overall dimensions of all the component parts. Usually pipe diameters different types do not match their dimensions.
When installing natural ventilation from scratch, the use of sewer pipes is quite possible.
But if you need to add to the existing ventilation sewer pipes, it probably won't work. The sizes of products and connecting elements will be very different; it will not be possible to assemble such a system.
Many people think that plastic sewer pipes give off toxic substances. Therefore, for your own reassurance, it is better to install such products on exhaust ventilation.
Harmful vapors, if any, will be removed from the room. There is no need to talk about the appearance of sewer products.
PVC pipes for ventilation look more beautiful, they will harmoniously fit into any interior.
It is difficult to imagine a modern residential or industrial premises not equipped with a full-fledged and high-quality hood.
Ventilation for human life is simply necessary, so it cannot be ignored. However, ventilation is not an abstract, fixed mechanism. This is a real piping system, the main component of which are pipes for ventilation.
Ventilation pipes are somewhat different from water supply or sewage pipes. They are also made of steel and plastic, but the requirements for them are different. In this article we will learn everything about ventilation pipes, their properties and important nuances.
Content of the article
Types of ventilation and their influence
The task of ventilation pipes is to provide ventilation indoor spaces in a private house.
In shape different ways... There is exhaust ventilation, supply ventilation, supply and exhaust air supply system, etc. These systems differ from each other in terms of the tasks set and the ways to accomplish them.
The hood, which is generally found in any private house and even in an apartment (in apartments, the hood is mounted at least in the kitchen) performs standard functions for removing air from the room.
Conversely, forced-air ventilation provokes the supply of air from the outside, thus filling the room with fresh oxygen.
The most private and convenient option is the supply and exhaust system, which simultaneously removes stale air and supplies clean air.
Design features
Whatever it is, it is important to take into account its features and the way of working with pipes.
In particular, the nuances in the scheme of their placement, laying and connection. Any air system is based on flow diversion. The easiest way to organize the withdrawal is on the roof of a private house.
Why on the roof? Because for natural exhaust, that is, not supported by fans, slight pressure drops are necessary so that the air flows themselves can go into the zones of changed pressure.
Having mounted a working riser on the roof from the ventilation pipes, you can achieve excellent oxygen circulation without the use of additional means at all.
Plus, it's easier to work on the roof, it's not so scary to damage or break the design concept. The last point, by the way, is of great importance, especially if you are going to lay the ventilation pipes after the walls have been built in a private house.
Any private house has a certain design idea and interior concept. What will definitely not fit into it is the pipes for ventilation with a diameter of 200 mm laid under the ceiling. So you have to install suspended ceilings and other decorative systems to hide communications.
On the roof of a private house, as a rule, there are no such problems. Therefore, you can install full-fledged ventilation junctions, riser outlets and other working equipment on the roof.
Types of pipes
Let's consider the main, their properties and important characteristics.
First of all, the properties of ventilation products are determined not by the diameter, although the diameter is also very important, but by their shape and material.
According to the shape, the pipes are divided into:
- rectangular;
- round;
- non-standard.
There is a difference between them, but not too significant. Rectangular pipes have a rectangular cross-section, mostly square. Such products are easy to install, they are perfectly laid along the internal channels. Used in industry and residential construction.
Section size rectangular pipe, as a rule, fluctuates within fairly high values, from 200 mm per side. This affects the scope of their application.
On the other hand, there are products made of steel or plastic and less than 200 mm in cross section.
Round ventilation products have proven themselves in residential construction. A round pipe is more convenient to install, it is much easier to connect it to other, more ancient systems. For example, to an existing roof riser.
Diameter round pipe affects where exactly it will be applied. Diameter less than 200 mm is intended for steel or plastic blanks used as internal branches of air ducts. A diameter within 200 mm is used in ventilation ducts of a large sample, roof risers, etc.
Anything larger than 200 mm only used in industry, since in private construction for pipes with such a cross section, it is simply not possible to find work tasks. And the price for products with a diameter exceeding the mark of 200-300 mm is significantly higher.
Materials used
We have already examined the shape and diameter of the ventilation duct from the pipe, but did not consider the materials used. Meanwhile, it is the channel material that has a decisive influence on its scope and characteristics.
Modern ventilation pipes are divided into two groups: metal and polymer. Those, in turn, are divided into pipes from
- Galvanized steel.
- Of stainless steel.
- Corrugated flexible steel.
- Plastic.
Products made of galvanized steel are resistant to corrosion, durable and easy to learn, but they can only be used for cold ventilation.
Galvanized pipes for ventilation cope with air currents up to +70 degrees Celsius. All that is above provokes the heating of steel to critical values \u200b\u200band the destruction of the galvanized layer.
Can also be used for hot ventilation. They are generally considered the most reliable and durable. However, everything in this world has to be paid for. For their characteristics, stainless steel billets are paid with great weight and price.
Metallic ones were previously used where it was necessary to quickly connect a ventilation duct, without laying complex transitions.
Metal corrugations bend the way we need it, weigh almost nothing and are resistant to high temperatures... Almost ideal - when you need to connect the hood in an inconvenient place, bring out the fan, etc.
Plastic pipes have made a splash in the last 20 years. Polymers are better than steel in every way except for strength. But for ventilation, strength is far from the most important characteristic, so now most ventilation ducts are assembled exclusively from plastic pipes.
They are lightweight, cheap, affordable, easy and quick to install. It is convenient to assemble channels from plastic, because the connection of individual parts here, just like in water or sewer pipelines, can be carried out using diffusion or cold welding.
Features of ventilation pipes (video)
Ventilation insulation
Another important point is ventilation thermal insulation. Do veterinary channels need insulation and if so why? This question is being asked by many.
Insulation of ventilation pipes is a kind of protective mechanism. We all know that when air flows move, there are internal and external ambient temperatures. The internal temperature depends on the temperature of the moving air, the outside temperature depends on the temperature outside the duct, materials in contact with it, etc.
Take, for example. The hood removes carbon monoxide and combustion products from the space around the stove. Obviously, their temperature is higher than the average for the room. The air flow goes through the channel up to the riser on the roof. The smaller the hood diameter, the greater the concentration and temperature level.
At the same time, room temperature is kept outside the channel at best. That is, the difference in temperature conditions can reach 50-80 degrees, which provokes condensation on the walls of the channel.
The condensate falling out humidifies the air in the duct, worsens the general climatic conditions and the speed of ventilation. Moreover, when solidified, it remains on the pipe walls in the form of hard-to-remove deposits.
It will help to avoid such problems. The insulation is wrapped around the ventilation duct, secured with wire or external protection. It prevents the pipe from heating unevenly, therefore, eliminates the cause of condensation.
For the safe operation of heating equipment, whether it is a stove or a boiler, it is necessary to ensure that the combustion products are removed outside and without obstacles.
That is, a chimney must be installed.
Features of the functioning of the pipe
- Exhaust pipes ensure the removal of exhaust gases from boiler plants.
This requires a thrust, which is formed due to the different densities of hot gases that have already been exhausted inside and the flow of atmospheric cold air. - For the free passage of the air flow into the firebox of a heating boiler with exhaust air on natural draft, it is necessary to create a negative, sufficiently strong pressure in the boiler firebox.
- In those heating installations where a pressure that exceeds atmospheric pressure is created during combustion, the exhaust pipe must provide all conditions for the passage of air into the boiler, while weakening the resistance of the exhaust gases entering the pipeline.
Exhaust pipe types
There are these types of chimney designs:
- prefabricated multi-shell;
- factory-made pipes;
- pipes for waste products of combustion with a ventilation exhaust duct;
- moisture resistant pipes;
- free-standing chimneys.
Multi-shell pipes
- Basically, the precast multi-shell body is made of lightweight concrete.
- The inner surface of the case is lined with glazed fireclay.
- Mineral wool is used as thermal insulation.
- The flue collection pipes are lightweight and can be easily installed in a short time.
Prefabricated pipes
- The design of this type of pipes does not differ significantly from multi-shell pipes.
- Pipes manufactured at the factory are very economical as all their components are standard.
Exhaust pipes with ventilation duct
- This type of pipe is intended for individual installations heating systems.
- A pipe of this type solves two problems: it removes the gas that is being processed from the individual units connected to it and at the same time supplies them with air, which is necessary to maintain the combustion process.
Tip: the design of this pipe allows you to solve the problem of supplying the required volume of air to those houses that are equipped with individual heating installations and airtight doors and windows.
Free-standing pipes
- The chimney, which stands separately, can consist of the following elements:
- one or more internal gas outlet pipes;
- insulation layer;
- the outer body is made of reinforced concrete, brick or steel.
- Pipes of this type are only used for large central heating installations.
- The height of such pipes must comply with local air pollution scale standards.
Moisture resistant pipes
- Moisture-resistant exhaust pipes are designed to work with low-temperature heat generators or condensing boilers, in which the exhaust gas temperature is less than 100 degrees, due to which a large amount of condensate is formed, which can damage or even destroy the pipe.
- In such pipes, air is fed upward around the internal gas pipeline.... The air that enters, enters the basement part of the chimney, absorbs the collected moisture and discharges it outside through a special outlet.
What should be the dimensions of the chimney?
Chimney height
- The height of the chimney can only be determined in accordance with the volume of exhaust gases or pollutants that are discharged through its opening.
Advice: for low-power installations, the dimensions can be those specified by the manufacturer.
- The minimum height of an efficient chimney should be four meters in various applications.
Advice: if the uppermost heating installation uses gas as fuel, then its height must be at least 4.5 meters.
- The minimum height of the exhaust pipe relative to the roof level must be exactly 0.4 meters.
Advice: if thermal power, which is given to each of the heating installations connected to the chimney, exceeds the above rated power, then these heating installations each must have its own separate pipe.
