A person faces the issue of the proper organization of ventilation both during the construction of a small house in the country, and during the construction of industrial workshops, and during the arrangement of office buildings. For each case, you can choose the best ventilation option, but the use of galvanized steel air ducts can be considered a universal solution in any situation.

About the advantages of galvanizing

In general, they can be made from the following materials:

• plastic - the price of such a solution is minimal, but the scope is limited to private construction;

• aluminum - they are corrosion resistant, but aluminum is a rather ductile metal, so such ventilation ducts do not tolerate possible loads;
• from galvanized steel - practically have no flaws;
• from improvised materials. For example, an air duct can be built even from ordinary thick, well-fitted boards.

Note! Plank ventilation ducts can only be recommended for ventilation of outbuildings, such as cellars or basements in the country.

Galvanized ventilation ducts can be used almost without restrictions. They can easily cope with the transportation of hot air or vapors of aggressive substances. In addition, steel is able to withstand high temperatures while maintaining sufficient strength.

Plastic is completely incapable of withstanding prolonged exposure to elevated temperatures, and it cannot oppose anything to the effects of chemicals. The only advantage of this material is its low weight and ease of installation.

Ventilation pipes made of galvanized steel can withstand without reducing the technical and operational performance:

• temperature around +80ᵒС – without time limit;

Note! For the safety of personnel, air ducts transporting hot air are usually equipped with a heat-insulating layer.

• within a short time, the air temperature may rise up to +200ᵒС. even in the event of a fire at the enterprise, the ventilation system will not allow the area to smoke;
• galvanized pipes for ventilation do not require additional protection against moisture. A thin layer of zinc coating prevents corrosion.

Note! Even if the integrity of the zinc layer is violated, for example, by cutting a self-tapping screw, the steel still remains protected. The fact is that steel and zinc form a galvanic couple, and as a result of a chemical reaction, a thin oxide film covers the cut.

Methods for the production of galvanized air ducts

The technology directly depends on the cross-sectional shape of the pipe.

Ventilation pipes can be:

• round section– optimal aerodynamic characteristics;

• square or rectangular section- slightly worse aerodynamics, but easier to install due to flat surfaces.

The raw material for the manufacture of galvanized air ducts is thin sheet galvanized steel. As a rule, the thickness of the sheet does not exceed 1.0 mm, this provides a balance between acceptable weight and sufficiently high rigidity.

The manufacture of ventilation from galvanization is carried out according to one of 2 methods:

• in the case of a round section, either spiral-wound technology is used, or simple rolling of sheet metal, followed by seam joining of the edges;
• for profile air ducts, only one technology is used - a galvanized sheet is passed through a series of rollers, which give it the desired shape. Then the edges of the future ventilation duct are connected.

Spiral wound technology

Differs in extremely high productivity, in a minute the machine processes about 60 m strips. The production of galvanized ventilation using this technology consists in the fact that the machine simply bends a steel strip so that a round pipe is obtained.

At the same time, adjacent turns are overlapped, due to strong tension, the edge of the strip is slightly deformed and the tightness of the connection is achieved.

In addition to high performance, pipes produced using this technology are characterized by high rigidity. The helical seam plays the role of a stiffener, so that under equal conditions such air ducts can withstand a greater load than its straight-seam counterpart.

Longitudinal pipes

Ventilation galvanized pipes produced using this technology in terms of technical and operational indicators almost do not differ from spiral-wound pipes. They just have a little less rigidity.

The entire process can be divided into 3 stages:

• a strip of the desired length is cut;
• it is passed through a series of rollers;
• joining adjacent edges of the metal.

As for the profile pipeline, quite often everything is prepared at the ends of the section for the subsequent flange connection. The same technology is used to manufacture ventilation ducts from galvanized steel.

Elements of galvanized ventilation

When installing the ventilation system, you will need not only galvanized ventilation ducts, but also a number of shaped elements. For example, bends at different angles of rotation, plugs, gratings, tees, etc. Without these elements, installation is simply impossible.

Elbows

This is one of the most common types of shaped elements, used in cases where it is necessary to ensure a smooth turn of the duct. The main characteristic of the branch is the angle of rotation, options are available that provide rotation by an angle from 15ᵒ to 90ᵒ.

Note! Galvanized ventilation will work much worse if the duct turns many times at a large angle. This reduces the airflow rate.

As for the production of bends, a strip of variable width is used for this. Due to the unequal width, when bent, its ring width is different. The entire branch consists of several such rings, by adjusting the width of the strips, theoretically, any angle of the branch can be obtained, but for convenience they are produced in increments of 15ᵒ.

ventilation duct

Strictly speaking, a ventilation duct is just a vertical rectangular or square duct in which several ducts with a smaller cross section are placed. Depending on the operating conditions, plastic, aluminum or galvanized ventilation ducts can be used.

If you mentally cut this structure across, then the observer will see not 1, but 3 channels. The largest one is a common ventilation duct, and 2 smaller ones ensure the removal of unpleasant odors from the underlying apartment. As a rule, 1 outlet is used in the kitchen and 1 in the bathroom or toilet.

Given the small area of ​​​​the kitchens and bathrooms of most apartments, many people are thinking about how to minimize the area of ​​​​the box and make it invisible. Galvanized ventilation ducts can help with this.

Note! Residents of multi-storey buildings are often mistaken, considering the ventilation box as their property, and demolish it. If the case comes to trial in court, then the unfortunate builders will have to restore the destroyed with their own hands.

Other shaped elements

In addition to bends, when installing ventilation, you may need such shaped elements as:

• transitions or ducks - used to shift the duct. In parallel with the displacement, by reducing the diameter, it is possible to adjust the speed of the air flow;

• plugs - used if necessary to block the free end of the pipe;
• gates - control devices;
• fire dampers;
• crosses and tees - serve to create complex nodes of the ventilation network;

• nipples - used when installing pipes;
• galvanized steel ventilation grilles - used to protect against insects, small animals and debris from the ventilation duct entering the room.

About mounting technology

As for fixing the channel to the walls or ceiling, you can get by with ordinary clamps or even just hang the pipe on a metal tape. In industrial buildings, for laying an air duct, a bracket is embedded in the wall, and the pipe rests on it.

Note! If the air velocity is high, then fixing the duct with clamps or metal tape will not provide sufficient rigidity. The pipe will rattle, so you need a more secure mount.

Special attention should be paid to the tightness of the joints of individual sections.

The connection can be made in several ways:

• nipple. The nipple itself is a section of a pipe of a slightly smaller diameter, it is simply inserted into the duct with force and rotated. The instructions for making a socket connection look the same, with the only difference being that the diameter of the socket is larger than the diameter of the duct;

• flanged- the strength of the joint is achieved by simply tightening the bolts;

• folded- a reliable joint is provided due to the joint deformation of the metal of different pipe sections.

In modern construction - even multi-storey, even cottage, even commercial, even residential - systems of passive and active ventilation, air heating and air purification are widely used.

If earlier voids were specially left in ceilings and walls for these purposes, today ventilation communications are laid using ventilation ducts (they are also called air ducts, ventilation pipes). These are special tubular hollow structures that allow you to distribute supply air and remove polluted air.

Types of air ducts

The production of ventilation ducts can be quite a profitable business, but first you need to decide what specific types of structures you want to manufacture. Air ducts can be classified according to different criteria. So, depending on the shape, round and rectangular ventilation ducts are distinguished, based on the material used, the structures can be plastic, steel (galvanized or stainless steel), aluminum, polyester, thermoplastic, silicone, fiberglass, and so on.

According to the presence of special properties, air ducts are divided into fire retardant, stainless and others, according to the method of connection - into those that have special fasteners and those that are connected using nipples. There are two main types of ventilation ducts: flexible (they are also called frame) and rigid.

Choosing which ducts to produce

Making rectangular or round ventilation pipes from aluminum or steel is the easiest option. Such structures are faster and easier to install than plastic ones, and also have a lower cost, they do not rust, are fire retardant, and have low aerodynamic resistance.

Installation of ventilation with such air ducts can be carried out at enterprises, in offices, sports, educational, cultural and entertainment institutions, public catering organizations and in general in any buildings where there are large premises, during the operation of which active air exchange is expected.

Making flexible ventilation ducts is a more complex process. They can only be used in specific conditions, for example, in rooms with a complex configuration or in buildings where ventilation installation using large galvanized ventilation pipes is not possible. Also, such structures are used in rooms where it is impossible to provide active ventilation systems, for example, hoods to remove hot air and acid vapors.

The cost of manufacturing ventilation pipes from rigid materials will be less, but it is necessary to start production with them not for this reason, but because you can quickly implement such air ducts.

Production process

Structures of any kind are made on special automatic machines. In fact, the production process is a conventional roll forming operations. We will not talk in detail about how to make a ventilation duct. After all, this is not done manually, but with the help of technical devices. Therefore, the most important task for you, if you want to create a successfully functioning enterprise, is to choose good equipment for the production of ventilation.

We take into account important parameters

When choosing fixed assets, be guided by the main parameters of air ducts: stiffness, area and cross-sectional shape (based on the degree of demand in the market). We have already talked about rigidity, so everything is clear with this. Flexible ventilation ducts can be sold more expensive than rigid ones, but they are also less in demand.

As for the area and shape of the section, here the matter with the choice is more complicated. Different indicators will depend on which particular designs you will use, for example, the speed of the air flow, and, consequently, the level of noise emitted by this flow in case the speed standards are exceeded.

Other selection factors

The production of round ventilation ducts is less laborious, since they are fastened with clip-on nipples. Also, such air ducts are faster and easier to install, because they do not have protruding parts. They are durable and, due to their more natural shape, create less aerodynamic drag.

At the same time, rectangular ventilation pipes show the best indoor airflow when a large cross-sectional area is required or when installation is carried out in more difficult conditions, for example, above false ceilings.

The production of round and rectangular ventilation ducts is carried out from the same materials: either aluminum with a thickness of half a millimeter to a millimeter, or galvanized steel. According to statistics, their sales volume is also almost equal, they are in the same demand.

And yet, if you want to make your business more successful, purchase ventilation production equipment, including lines for the production of both round and rectangular pipes. What kind of cars do you need?

We equip the workshop for the production of air ducts

So, the production line for the manufacture of ventilation ducts of any section should include:

• feeding device;
• automatic machine for unwinding metal rolled sheet;
• device for straightening a sheet (the technology allows a diagonal deviation of both the blank sheet and the air duct itself by 0.8 millimeters - if the ventilation pipe has a strong geometry violation, then a lot of noise will be emitted from the air flow, so modern technology necessarily includes a straightening device );
• industrial numerical control system;
• guillotine that cuts off the finished duct.

The line used for the production of rectangular and round ventilation pipes differs only in that in the first case, the shaping units are corner cutting devices, a rib stiffening system, an automatic sheet bender equipped with a rotary beam, and in the second case, rolling rollers.

Process line cost

The production of ventilation ducts is quite expensive. A line for the manufacture of circular ducts (provided that the manufacturer is domestic) will cost about one and a half million rubles.

The cost of the line for the production of rectangular ventilation pipes will be from 1.8 million rubles and more. That is, in order to purchase both lines, you need to have in stock no less, but 3.3 million rubles by the most minimal standards.

Payback period

But there is also good news. Profitability in this area of ​​​​business is quite high. And if you sell a running meter at a price of 120-3000 rubles (depending on the diameter of the pipes), then even if you work in one shift five days a week, you can recoup the costs in six months.

Development prospects

The production of ventilation ducts is a promising business. Having established the technological process, you can expand your business and also engage in the manufacture of connecting and fastening fittings for pipes: plugs, nipples, "umbrellas", tie-ins, mounting punched tape and other things. Such products can be made from substandard goods, scraps and other waste.

In addition, try to enrich the product range: start making rigid plastic, polyester, silicone, flexible PVC, rubber and other air ducts. This will allow you to at least occupy a regional market segment in the field of ventilation systems.

Having worked steadily for at least six months and having thoroughly prepared the technological base, you can engage, among other things, in organizing services for the design and installation of ventilation systems. To do this, you will need to hire engineers who specialize in heat and gas supply work.

These are sought-after specialists at the present time, so get ready that their work will not be cheap at all. Also, among the employees you will need installers, but their work is not valued so highly, it is believed that these are low-skilled workers, and sometimes they may not be qualified at all. Having recruited staff, you can offer services for the installation of ventilation systems.

The materials used in the manufacture of air ducts, the main technological processes and the types of machines necessary for the implementation of this production cycle.

1. The dependence of the thickness of the walls of the duct on the area of ​​its section.

2. The main types of machines required for the manufacture of steel galvanized air ducts.
The guillotine.
· Bending machine.
· Folding machine.
· Falseosadochny machine.
· Stiffening rib machine.
· Puklevochny machine.
ZIG machine.
· The device for production of works on spot welding.
· Spiral winding machine.
· The machine for production of branches of round section Gariloker (GORELOCKER).
· Rolling machine.

1. Materials used for the manufacture of galvanized steel air ducts.

Air ducts made of galvanized steel are mainly made from a sheet with a thickness of 0.5 - 1.2 mm, depending on their standard sizes, for example:
a rectangular air duct, ranging from 100x100 mm to 500x200 mm, is made of 0.5 mm thick galvanized steel sheet;
a rectangular air duct, ranging from 500x300 mm to 800x200 mm, is made of 0.7 mm thick galvanized steel sheet;
Rectangular air duct, from 800x300 mm up to 1000x1500 mm, is made of 1.2 mm thick galvanized steel sheet.

Used steel grade ST-3, ST-6.

2. The main types of machines required for the manufacture of steel galvanized air ducts:

Each machine is designed to perform one unique or several related technological operations for processing galvanized steel sheet, gradually turning it into a semi-finished product, a set of fittings and, finally, an air line ready for operation, consisting of a system of air ducts and ventilation equipment.

Guillotine.

The machine is designed to cut the steel sheet across the entire width of the roll and for nothing else. Structurally, it is a workbench on which a knife with a counterweight or an electric drive is mounted.

Bending machine.

The machine is intended for bending a steel sheet to the required angle (from 00 to 3600). Structurally, it is a bed with two guides, movable and fixed. The movable guide bends the sheet. The drive can be manual or electric.

Folding machine.

It is intended for the production of several types of locks connecting the edges of a steel sheet, and, accordingly, for connecting different sections of straight-seam air ducts: single lock, double lock. Structurally, it is a frame with a rolling mechanism and an electric motor.

Folding machine.

This device is designed to tighten (settle) the corner at the junction of the extreme edges of two steel sheets, that is, to close the lock and obtain a tight connection between two adjacent sections of a straight-seam duct to each other.

Rib machine.

It is intended for the manufacture of stiffeners that serve to reduce the vibration of the duct walls during the passage of air and, accordingly, reduce noise. Air ducts, the walls of which are equipped with stiffeners, do not rattle during operation and “keep their shape” better.

Punch machine.

Serves for processing of places of connection of an air duct with a flange and giving them necessary rigidity, durability and tightness. In fact, the machine presses through the sheets of the flange and air duct, ensuring the strength and immobility of their connection to each other.

ZIG machine.

Designed for the manufacture of the correct angles on the edges of the sheets at the points of attachment to the sections of the air ducts of the following fittings made of galvanized steel sheet: bends, half-bends, reductions and tie-ins. In fact, the machine performs flanging and preloading of the edges of parts previously cut from galvanized steel sheet on other types of machines, GORELOCKER, for example.

Apparatus for the production of work on spot welding.

Carries out welding operations for joining sheets of steel by spot welding. It is used for the manufacture of section transitions of galvanized steel air ducts, mixing and distribution chambers of central and duct air conditioners, silencer sections and adapters.

Spiral winding machine.

It is applied by production of air ducts of exclusively round section. The thickness of the steel sheet used for the manufacture of spirally wound air ducts directly depends on the cross-sectional area of ​​the air duct - the larger the area, the thicker the sheet.

The air duct of circular section, starting from a diameter of 100 mm, and up to a diameter of 500 mm, is made of galvanized steel sheet with a thickness of 0.5 mm;
circular air duct, starting from a diameter of 500 mm, and up to a diameter of 900 mm is made of 0.7 mm thick galvanized steel sheet;
Circular air duct, from 900 mm in diameter up to 1250 mm in diameter, is made of 1 mm thick galvanized steel sheet.

The maximum allowable cross-sectional area of ​​​​the air duct that this machine is able to digest is 1.13 m2, with a diameter of 1250 mm.

Gariloker (GORELOCKER).

The machine of this type is designed for cutting galvanized steel sheet into segments, and further manufacturing bends and half-bends with a diameter of 100 mm to 1250 mm inclusive.

rolling machine.

This device is designed for the production of round straight-seam air ducts. Allows to make shaped products and inserts from 50 mm long. up to 1250 mm. inclusive: adapters and section transitions (from rectangular to round, and vice versa). It is also possible to manufacture a straight section of the duct, however, its length will be limited to 1250 mm.

The machine park listed above is used in the production of galvanized steel air ducts and fittings of the following types:
- Straight-seam galvanized steel air ducts of square section with a length of 10 cm to 2.5 m inclusive;
- Straight-seam galvanized steel air ducts of circular cross section from 5 cm to 1.25 m long inclusive;
- Spiral-wound galvanized steel air ducts with a length of 50 cm to 5 m inclusive.
- Section transitions (designed to connect air ducts of various diameters and section shapes).
- Elbows (Designed to rotate the duct by 900, can be either round or square).
- Semi-bends (Designed to rotate the duct by 450, can be either round or square).
- Tees (They are intended for dividing the air duct line into two parts of the same section, in a non-standard version it is possible to divide into equal parts with a transition to a larger section, for example (100x100/100x100) / 200x100).
- Adapters (Intended for attaching gratings of both ceiling and wall types. A non-standard part that requires the development of an individual drawing. Structurally, the adapter is a steel box with an inset on top or side).

Reduction (A shaped piece designed to switch from a main pipe to an air duct of a smaller diameter. Reductions of both rectangular and round sections are used. Structurally they are divided into straight tie-ins and saddle tie-ins. The length of the tie-in cannot be more than 20 cm).

Reminder: You can wholesale components and spare parts for industrial ventilation systems from us: fastening of air ducts, air conditioners, rectangular and round air ducts, traverse, mounting rail, galvanized corners, bracket for connecting flanges, mounting tape, perforated, tape clamp, aluminum tape, brackets, gratings and anemostats, sheet and roll insulation, galvanized metal sheets. We also wholesale fastener elements: threaded studs, self-tapping screws, screws, bolts, screws, nuts, washers, rivets, drive-in anchors. Deliveries go throughout Russia, from a warehouse in Moscow.

Good day!

Not a single residential, office, retail, industrial or warehouse space today. And air ducts made of galvanized steel deservedly occupy a leading position among various ventilation ducts. About what this popularity is due to and how not to get lost in the variety of the presented assortment, we will tell in the next material.

Galvanized air ducts are the most common type of ventilation pipes. Which is easily explained.

Advantages of galvanizing:

• Light weight, due to which the installed structures create insignificant loads on the buildings. In addition, the lightness of the material facilitates the process of delivery to the installation site and engineering work.
• The flexibility of the material makes it possible to give the air duct elements any shape, which not only expands their range, but also improves the aerodynamic characteristics of the line.
• Strength and resistance to open fire and aggressive environments. This significantly expands the scope of use and increases the service life of ventilation pipes made of thin-sheet galvanized steel from 10 years or more.
• Low cost.

Galvanized ventilation ducts are easy to maintain. They do not require preliminary priming, since the metal is not subject to an active corrosion process. Aesthetic appeal allows them not to be painted.

The disadvantages of galvanized steel include:

• Increased noise level, characteristic of any metal structure. However, this problem can be solved either by a well-thought-out wiring scheme that minimizes the number of bends and transitions, or soundproofing.
• Tendency to form and accumulate condensate. As a solution - insulation of the pipeline.
• Susceptibility to deformation as a result of a powerful mechanical impact caused by a strong impact, displacement or fall of the structure. Under normal operating conditions, such difficulties do not arise.

The combination of quality, cost of the material and a variety of technologies that minimize the disadvantages make galvanized pipelines the most popular types of air ducts used in the arrangement of ventilation mains.

Types of galvanized air ducts

A variety of galvanized air ducts is due to a number of technical characteristics that products are endowed with in the production process. So the following types of products are distinguished:

1. Cross-sectional shape: rectangular or round.
2. By type of seam: welded and folded.
3. In the direction of the seam: spiral wound and straight seam.

Rectangular and round

The advantage of rectangular air ducts lies in the configuration and variety of the model range, which allows you to adapt the ventilation circuit to the characteristics of any room without compromising the calculated cross-sectional area, playing with the width and height of the pipe.

Straight seam and spiral wound

Longitudinal welded pipes are made by bending a sheet of galvanized steel into a round or rectangular pipe. This technology reduces the cost of products, but it also limits its length, which increases the number of connecting elements of the pipeline.

Spiral-wound (spiral-lock or spiral-welded) air ducts are twisted from a thin metal tape. In this case, the seam goes in a spiral and plays the role of a stiffener, which increases the strength of the pipe, and when using the welding method, ensures its tightness.

Spiral-wound air ducts are characterized by:

• less weight;
• increased tightness;
• a small number of butt elements;
• increased speed of movement of the air mass, tk. the spiral shape creates additional rotation in a closed loop;
• reduced noise level.

However, the ribbed surface provokes the accumulation of dust inside the pipeline.

Tightness and density

Tightness and pressure are indicators that ultimately determine the efficiency and cost of the ventilation circuit. A leaky line reduces the quality of air exchange and entails an unreasonable increase in the capacity of pumping equipment, an increase in energy costs, and also leads to the accumulation of condensate inside the pipes.

There are 3 classes of tightness of air ducts:

1. A (low). Air permeability from 1.35 to 0.45 l/sec/m².
2. B (medium). Air permeability from 0.45 to 0.15 l/sec/m².
3. C (high). Air permeability less than 0.15 l/sec/m².

By the coefficient of internal pressure (density) distinguish:

• H-models (normal pressure). Designed for ventilation and smoke removal systems of objects belonging to the category of fire hazard class "B" and "G". Do not require strong sealing, tk. allow a certain percentage of leakage. Rubber seals are usually used as a sealant.
• P-models (dense). They are installed at facilities equipped with powerful pumping equipment and classified as fire and explosion hazardous. They are characterized by 100% tightness of seam joints and the presence of a hermetic lock at the junction of the elements with each other.

What is better and where is it used?

The protective layer of zinc resists the damaging effects of open air, moisture and ultraviolet radiation. Therefore, galvanized ventilation ducts are actively used both indoors and outdoors for arranging systems:

1. natural and forced ventilation,
2. conditioning;
3. aspiration (removal of small particles contained in the air);
4. smoke removal (removal of combustion products);
5. removal of exhaust gases;
6. transportation of gas mixtures, purifiers and air humidifiers.

Even the organization of a conventional hood in the kitchen is most often carried out by means of steel ducts.

When deciding on the use of one or another type of air duct, one should be guided by the features of the operation of the future design:

• Rectangular air ducts are used to save space in small predominantly residential or service premises (private houses, apartments or offices).
• For aspiration and transportation of harmful gases, round pipes with a welded seam are suitable, providing maximum air speed and complete tightness of the housing.
• In industry, preference is given to round shapes, characterized by both the greatest efficiency and the lowest cost.

Elements of the ventilation system

The ventilation line is always a complex structure, consisting of numerous elements that allow:

1. change the direction of the contour depending on the configuration of the premises;
2. bypass ledges;
3. connect several circuits into a single network.

Branches and boxes

The main elements of the duct that determine its direction are ducts and bends. The former pave the path in a straight line, the latter change the contour geometry at an angle of 15⁰, 30⁰, 45⁰, 60⁰ or 90⁰.

Other shaped elements

Ventilation is a complex and extensive network of channels, which is problematic to mount without the appropriate elements. Such components are usually called shaped products.

These include:

• Adapters connecting circuits of various diameters to each other - confusers and diffusers. The former narrow the highway, the latter expand.
• Tees and collar tie-ins, ensuring the adjoining of two mains to each other.
• Crosses used to cross two perpendicular air currents.
• S-shaped adapters (ducks) connecting two circuits that do not match in axis and / or section.
• Round nipples and couplings connecting two round boxes. The first are inserted inside, the second are put on over the pipes.
• Plugs installed at the ends of the circuit.
• The umbrella is roof, preventing hit of an atmospheric precipitation in a ventilating shaft.
• Supply and exhaust grilles and other shaped parts.

Dimensions

GOST

1. GOST 14918-80 - air ducts made from steel sheet with a thickness of 0.5 to 1 mm by rolling and designed to transport air with a humidity of not more than 60% and a temperature of less than 80⁰C.
2. GOST 5632-72 - air ducts characterized by a high degree of tightness, resistance to corrosion and high temperatures (about 500⁰C) and designed to move hot air and chemical gases.

Size Chart Weights and Diameters

Production of galvanized air ducts

Galvanized air ducts are manufactured on special metal-working equipment from thin-sheet cold-rolled steel in accordance with the standards established by the state (SNIP 41-01-2003 and TU 4863-001-75263987-2006). Cutting of metal occurs in automatic mode according to the parameters set by the program.

• Circular sections are processed by rollers, which give the workpiece the required diameter, followed by rolling the longitudinal edge on a seam-rolling machine.
• Spiral-wound ones are made using a different technology: steel with a width of 137 mm is twisted in a spiral with a seam inward.

The use of high-quality galvanizing prevents the galvanized coating from peeling off the metal at the bending points of the product.

Technological standards prescribe for each type of section to use metal of a certain sheet thickness:

Average cost and where to buy

The cost of air ducts made of galvanized steel depends on the size of its cross section and the thickness of the metal. The price is calculated for 1 m². On average, the cost of 1 m² of a product on the market is about 320 rubles. Installation work will cost an average of 700 rubles. for the same square metre.

Despite the wide representation of air ducts in online stores, it is still worth buying them directly from the manufacturer, who is able to accompany each product with a quality certificate.

How to choose?

The operation of the air exhaust system (SVO) depends on how correctly the area of ​​\u200b\u200bits section is calculated.

S - Sectional area.

P - CBO performance.

v - The speed of movement of the air mass (for residential premises, an indicator of 3-4 m / s is used).

Determination of ventilation performance involves determining the amount of air required for a comfortable stay in the room. It is calculated in 2 ways:

• Air volume required:

P - CBO performance.

A - The number of people in the room during the hour.

n - Air consumption rate according to SNIP 41-01-2003 and MGSN 3.01.01.

• By the frequency of ventilation (ventilation):

P - CBO performance.

V - The volume of the room (with equal data, the entire room)

k - The ventilation rate established by the standards of SNIP 41-01-2003.

shape and diameter

The quality of air exchange, energy efficiency and design of the room depend on the selected configuration and the size of the air duct section. Therefore, the choice of air channels should be approached in detail:

1. The smaller the diameter of the duct, the higher the speed of the air mass. It is important to be guided by the principle of the "golden mean", because the higher the speed, the higher the noise level.
2. Round air ducts provide faster air movement, are easier to install and are cheaper.
3. Rectangular are stronger and harmoniously fit into the design of any room.

Construction and rigidity

Depending on the specifics of the design application, there are:

• rigid, semi-rigid or flexible;
• standard or thermally insulated;
• fire retardant.

The tighter the seams, the stronger the connection and the longer the period of operation.

Material

Galvanized ventilation ducts are made of a standard type and insulated.

1. The design of insulated models provides a special insulating layer of mineral fiber, polyurethane, foam elastomer, felt or other materials. They maintain the optimum air temperature inside the circuit, preventing the formation and freezing of condensate on the walls. In addition, they reduce the noise level.
2. Zinc coating can be one-sided or two-sided. Due to the formation of condensate inside the circuit, double-sided galvanizing is more practical, because. protects the contour from the internal corrosion process.

Not so long ago, galvanized aluminum ducts appeared on the market, the coating of which is 95% zinc and 5% aluminum. They are characterized by greater ductility and improved anti-corrosion properties.

Fastening

Ways to fix the air ducts depend on the configuration:

• with a round section, coupling, bandage and nipple connection of elements are used;
• rectangular air ducts are fastened with latches and mounting brackets.

Sometimes welding is used.

Installation rules for galvanized ventilation

The laying of ventilation ducts from thin-sheet galvanized steel is carried out in stages.

Duct production

Box for ventilation and air conditioning systems are used in the construction of any duct systems. The material for their manufacture is selected depending on the actual operating conditions, the parameters of the working environment, and also on the purpose. For the manufacture of air ducts uses low-carbon steel, "galvanized" or "stainless steel", as well as various types of plastic.

Air ducts for ventilation made of "galvanized" are used in air exchange systems with a working environment with a temperature of up to + 80C (a short increase up to + 200C is possible) and humidity up to 60%. Air ducts made of galvanized steel can be used in areas with any climate in accordance with GOST 15150, subject to non-aggressive working environments (air and gas-air). Galvanized air ducts do without an additional protective coating, since the top zinc layer protects the metal from corrosion even in places of its damage (due to the steel-zinc galvanic pair, which forms an oxide film under the influence of atmospheric oxygen).

Air ducts made of stainless steel are designed to work with superheated air and aggressive gas-air mixtures. Working environment temperature - up to +500С (short-term increase up to +700С is allowed). As a procurement material for the production of stainless steel air ducts, steels are used according to GOST 5632-72 (heat and corrosion resistant).

"Black" air ducts are made from mild steel. Workpiece thickness - from 1.2 to 15 mm. "Black" air ducts for ventilation are well tolerated by high temperatures and exposure to open flames (they are slightly susceptible to deformation - the air ducts of the ventilation system will not depressurize, and the fire will not spread to neighboring rooms).

For aspiration systems and smoke removal, "black" ventilation ducts are the right choice. Simple carbon steel ventilation systems are mainly in demand in production areas where excessive emission of gases, dust, etc. is possible.

Air ducts can be round or rectangular in cross section. The production of rectangular ducts is a classic of ventilation systems, but thanks to progressive technologies, the market is increasingly losing ground to round ducts, since they are more technologically advanced in manufacturing, have better aerodynamic characteristics and are easy to install. To date, the production of round air ducts is "gaining momentum", becoming more and more popular.

For the installation of air ducts in a single line, various shaped components are used, which are conventionally divided into typical (corners, turns, splitters, "ducks", transitions, etc.) and non-standard (adapters for ventilation grilles or reducers for air exchange systems).

Air ducts made of polymers (plastic) in some cases can be an excellent alternative to metal counterparts. Among the advantages of plastic air ducts, it is necessary to highlight the low specific weight, ease of installation (no need for special tools and fixtures), reasonable price. But plastic air ducts are not suitable for moving chemically aggressive gas-air mixtures.

There are rigid, semi-rigid and flexible plastic ducts. Rigid air ducts can be round or rectangular, while flexible and semi-rigid air ducts are only round in cross section.