Do-it-yourself turbo deflector: drawing and stages of work

If you are attentive, then you have probably noticed on some roofs special spherical devices that also spin. These are special ventilation deflectors, which today are indispensable in the ventilation systems of apartment buildings and suburban real estate. They work without electricity, but still do their job perfectly. They also decorate the roof of the house in their own way, introducing a unique dynamic element into the overall design.

Moreover, making such a turbo deflector with your own hands is not at all difficult - the main thing is to carefully study the principle of its operation and select weather-resistant materials. We will now tell you which ones, what to do with them and how to avoid mistakes.

Why do you need a deflector?

For a better understanding of the issue, we present data from reference literature. The magnitude of local resistance to air flow in ventilation systems is characterized by a dimensionless coefficient. The greater its value, the stronger the shaped element - umbrella, elbow, gate - slows down the movement of gases through the pipeline.

In relation to our cases, the coefficient is:

• at the exit of the air flow from an open pipe of any diameter ξ = 1;
• if the channel is covered with a classic cap, ξ = 1.3–1.5;
• a Grigorovich umbrella with a diffuser (section expansion) is installed on the pipe, ξ = 0.8;
• Volper nozzle is cylindrical or star-shaped “Shenard”, ξ = 1;
• TsAGI type deflector, ξ = 0.6.

Note. There is no mistake here - even with free release from the shaft, the air stream overcomes local resistance from sudden expansion. Source: Handbook of Heating and Ventilation, 1976 edition.

So, a deflector is a nozzle that, under the influence of wind, creates a vacuum at the outlet of the vertical ventilation duct and thus reduces the aerodynamic resistance to the flow. That is, it acts as a traction amplifier.

In addition, the exhaust device solves the following problems:

• protects the air duct from precipitation;
• does not allow the wind to blow inside the pipe;
• prevents the occurrence of reverse thrust (overturning).

The operating principle of any deflector is based on two effects: vacuum from the wind load and ejection (entrainment) of a slow gas flow by a faster one. Although some foreign manufacturers implement mechanical incentives - they simply equip the umbrella with an electric fan. Let us consider the structure of each design separately.

From this angle it is clearly visible that the cross-section of the lower nozzle pipe does not decrease, which means that the speed and pressure of the gases does not change

Comment. On the Internet, the operation of such caps is often explained by the action of Bernoulli’s law or the Venturi effect. Both physical phenomena involve a narrowing of the air duct, an acceleration of flow and a drop in pressure. In reality, deflectors do not reduce the cross-section of the channel (see photo above) - the vacuum is created solely by the force of the wind.

Selection rules

You can select the optimal deflector based on the goals and tasks assigned to it. It is also worth considering the conditions in which it will operate.

A simple chimney is a cap on a wood-burning chimney, made in the form of a regular umbrella, and has the following advantages:

• maintains the necessary traction both in calm conditions and in the movement of air masses with a power of up to 10 points;
• does not create excessive pressure on the pipe, due to which even in a severe storm the chimney remains in its place; rather, the umbrella itself can break off and fly away;
• has a simple and understandable design;
• practically does not coke or clog, and is quite easy to clean;
• due to the imperfection of the aerodynamic structure, it is insensitive to the shape of the umbrella; if the building is located in the wind, then the chimney can be made in the form of a tent, this greatly simplifies its use and opens up great opportunities for the implementation of design ideas.

At the same time, there are serious disadvantages, such as:

• in weak winds it reduces draft, and the stronger the heating element works, the weaker it is. This is quite dangerous, since in cold winter weather, in the absence of wind, the stove can “choke” and breathe fumes into the living quarters;
• in strong winds, on the contrary, it creates too much draft. This significantly reduces the efficiency of indoor stoves and fireplaces;
• in gusty winds it can cause blowing into the pipe and creating a reverse draft effect.

The aerodynamic open model maintains sufficient draft in any wind for efficient operation of stoves and boilers using liquid fuel and gas. Such deflectors can freeze, they easily become littered and quickly become covered with soot and soot, however, they are easy to clean.

The disadvantages include the following:

• complex body of rotation;
• as a result of the load created by air masses, the umbrella itself can easily fly off the chimney, and at the same time, the direct mechanism of the device can collapse the pipe itself;
• with strong gusts of wind from force 8, the lateral pressure on the structure increases significantly and further increases in accordance with the power law;
• open structures are quite poor at reducing strong dynamic loads resulting from gusts of wind, which is why in no case should such a model be placed on pipes made of brick;
• the modification cannot be used for pyrolysis heat-generating mechanisms, otherwise, when wind occurs, all pyrolysis gases will be sucked out and the stove or boiler will simply go out;
• not suitable for creating design elements, since it is unsuitable for decoration; all kinds of blotches and figures only worsen the overall aerodynamic status of the structure as a whole.

By the way, an interesting study was conducted in the USA. There, at one time, they studied issues related to open deflectors and installed them on locomotives to check the degree of increase in efficiency at low speed. At the same time, the result was the most depressing - at mid-speed, fire began to burst out of the pipe and not a single train was able to reach its maximum speed. In general, the open version of the deflector should be recommended for all types of heating devices, with the exception of pyrolysis ones. At the same time, it must be checked and cleaned at least once a quarter. It is optimal for a chimney with low draft force, it is most effective for wood-burning sauna stoves; not a single case of people burning out due to the ventilation deflector in saunas has been recorded.

The closed or as it is called “perfect” type has such advantages as:

• provides stable draft, which is sufficient for stoves and boilers of any type;
• not prone to freezing and clogging from the inside;
• Dust and ice formed on the outside do not significantly change the operation of the device.

There are also disadvantages, however, users claim that they are not so significant, namely:

• when exposed to strong winds, it gives maximum pressure on the pipe, and then increases linearly, so the chimney under the deflector should be further strengthened with guy wires;
• has rather complex design and technological parameters;
• cannot be used as a design element, since any additional elements significantly reduce the overall level of aerodynamics.

Models may differ in appearance, purpose and material. Most often, plastic, stainless steel or aluminum are used to produce deflectors. In rare cases, copper may become a raw material for production. Many users prefer the sandwich model.

Types of deflectors

To improve the performance of the ventilation system, there are many types of deflectors on sale. Some of them are static, others are rotational. The latter include turbines in which the impeller head rotates, operating due to the power of the wind.

Note! Regardless of whether the deflector has a static body or a rotary one, they are all made to improve draft in the chimney or ventilation duct. They protect the system from precipitation and debris. However, the most effective device can confidently be called a turbo deflector.

Rotary turbines can be classified according to the following parameters:

1. Material of manufacture. Deflectors are made from stainless steel, galvanized or painted metal, aluminum.
2. The diameter of the nozzle or connecting ring is a minimum of 110 mm and a maximum of 680 mm. It is clear that the dimensions are identical to the diameter of the sewer pipes.

Despite the fact that manufacturers produce modifications of turbo deflectors that practically do not differ from each other in appearance, their characteristics are different. Below is some information about these products:

• Turbovent. The company of the same name produces rotary ventilation products made of aluminum. The products have a thickness of 0.5 to 1 mm. The base is made of galvanized steel, thickness from 0.7 to 0.9 mm. The turbo deflector can be painted in any of the colors according to RAL standards;
• Turbomax. Manufacturers make sales by calling the product a natural traction booster. To create a deflector, AISI 321 steel is required, the thickness of which is 0.5 mm. Scope of use: both for natural ventilation systems and for stove and fireplace chimneys. And this is not in vain, since the turbo deflector is able to withstand temperatures up to +250 ℃. Products are made from high quality stainless steel.

You can also find products from unknown brands on store shelves. Such products should be purchased carefully, paying attention to the certificate. Better yet, make a turbo deflector for ventilation with your own hands. Drawings and appropriate instructions are needed.

Design features

The design of the deflector is not very complicated. Its upper part (head) begins to rotate under the influence of the wind, thereby creating a vacuum in the pipe. The lower part, the housing, is fixed directly to the ventilation duct. To successfully install the turbo deflector in its place, holes for self-tapping screws are made in the lower part.

Note! Professionals recommend installing a turbo deflector not only in systems with problems. They are recommended to be used even for normally operating systems. Thanks to this small device, ventilation efficiency will improve by 20%.

Since the ventilation output can be different, the design of the turbo deflector also varies. There are the following types of turbo deflectors:

• round;
• square;
• rectangular.

The product is selected depending on the parameters of the system in the room. If the buyer needs it, the turbo deflector is sold complete with roof passages, which are used for roof angles from 15 to 35°.

Area of ​​use

Where exactly can turbo deflectors be used? The products have proven themselves excellent in rooms and facilities where air exchange is extremely necessary. Scope of use:

1. For private and apartment buildings. In addition, it should be noted that increased demands are placed on the operation of ventilation ducts in a high-rise building. Often in such houses the quality of ventilation is not the best, since they were made in the Soviet Union. But thanks to the use of a deflector, this problem is solved.
2. Turbo deflectors are good for livestock farms and agricultural buildings such as stables, poultry houses, granaries and haylofts. They help ventilation more effectively remove odors, fumes and gases generated when keeping livestock. In addition, the humidity in the room is controlled, it is optimal.
3. For processing enterprises. Since the turbo deflector does not require electricity to operate, the savings on the device are corresponding. The exception is enterprises that produce or process substances hazardous to humans.
4. Public buildings such as sports complexes, swimming pools, shopping centers and cinemas.

Important! The turbo deflector is also used to ventilate the under-roof space.

But how to make turbo ventilation deflectors with your own hands? Let's find out.

How the device works

Of course, to do something, you need to understand how it works. Same thing with the deflector. We can say that the principle of operation of the product is quite simple: due to wind energy, the deflector begins to create a vacuum of air in the ventilation shaft. This helps to increase draft; exhaust air exits faster, both from the room and from the under-roof space. After all, it happens that natural ventilation does not cope with this task, so the deflector helps to increase draft in the system.

Important! Such turbo deflectors are used not only for ventilation systems, but also for stoves and fireplaces, increasing draft and removing smoke faster.

It is noteworthy that whatever the direction of the wind and its strength, the impeller (the so-called rotating head) always rotates in one direction, creating a partial vacuum in the system. Thanks to it, the intensity of air movement increases. In addition, in this case, the formation of reverse draft is eliminated and air exchange is improved. As mentioned earlier, sediment and debris do not enter the system.

It turns out that for a natural type ventilation system a turbo deflector is simply necessary. It never fits, but in turn will make the ventilation work more efficiently.

Tools and materials

Let's say right away that such work is not the easiest, since the turbo deflector has a complex design. To bring everything to life, you need the following tools and materials:

• galvanized or stainless steel sheet;
• bolts, rivets, clamps and nuts;
• electric drill;
• scissors for working with metal;
• ruler, pencil and compass;
• drew;
• welding machine;
• several sheets of cardboard;
• regular scissors.

In the photo below you can see a drawing of the turbo deflector.

You will see exactly how to make it yourself from this video:

The main task is to make the landing part of the required diameter. After which plates with a tube in the middle are welded to it, where the rotating part will be installed. Blades are formed from sheets of steel according to a template, which are attached to the structure, forming a turbo deflector. The entire process and details are clearly depicted in the video.

When the turbo deflector is made, you can begin installing it. It is mounted on the chimney pipe. The lower part is put on the pipe and secured with bolts. This is a secure mount that will hold the structure in place.

Drawings of turbo deflector blades

Once the need for the number of these devices has been approximately calculated, drawings can be made. Based on them, the devices will then be manufactured. Drawings can be found on the Internet, but you can do without drawing them up. In general, they help save sheet metal used for the production of blades.

Using the drawing, patterns are made - for this they are transferred to cardboard and then cut out with scissors. Before fastening the individual parts together, they are adjusted to size. The diameter of the future ring is determined based on the diameter of the ventilation pipe or chimney. For connections, use self-tapping screws or bolts with nuts.

Review of popular models

In practice, the following types have proven themselves well: Grigorovich, Volpera, TsAGI, double and H-shaped deflector, rotary weather vane of the “Net” or “Hood” type.

The choice of “wind nozzle” is based on efficiency, cost of the deflector and climatic conditions of the area. Some models are available for self-assembly and installation

View #1 - classic Grigorovich cap

The most common option used in ventilation and smoke removal systems. Due to its simplicity and accessibility, the Grigorovich deflector holds a leading position among analogues.

The device is represented by a pair of umbrellas connected into a single “plate”.

The cap is installed on round pipelines or mounted through an adapter plate on rectangular and square shafts.

Basic equipment: 1 – diffuser in the form of a narrowed cone, 2 – protective umbrella, 3 – return hood. Mounting spacers connect the nozzle elements

Thanks to the design, double air ejection is carried out - in the direction of the expanded part of the diffuser and in the direction of the return hood.

The flow velocity under the lower cone increases due to the narrowing of the channel cross-section, as a result, the pressure difference increases.

Type #2 - TsAGI universal nozzle

This design was developed during the USSR by a specialized research institute (scientific institute). The deflector consists of the following parts (shown in the drawing):

• lower glass with a diffuser (extension) at the end;
• outer body – shell made of cylindrical roofing steel;
• cover in the form of an umbrella;
• cover fastening posts made of metal strips.

The operation of the product is simple: wind blowing the body from any side creates a vacuum zone above the diffuser open at the top. The exhaust gases coming from the mine are carried away by this rarefaction, come out and are picked up by the wind - the ejection principle works.

The table below shows the characteristics of typical TsAGI deflectors - dimensions, performance depending on the wind flow speed.

Comment. Capacity does not include the resistance of the duct system crossing the roof. The actual exhaust volume depends on the height of the pipe and the temperature difference between the indoor/outdoor air.

Of all the static traction amplifiers, the TsAGI cap is recognized as the most effective, despite the venerable age of development. Design advantages:

• ease of manufacture and installation;
• maximum protection against rain and snow, and traction overturning;
• reliability, no rotating parts;
• the direction of wind flows does not matter;
• lowest drag coefficient (0.6).

The disadvantage of the deflector is its dependence on wind speed. If the flows move slower than 2 m/s, the efficiency of the device tends to zero. However, calm weather has a negative impact on the operation of any attachment designed to enhance natural draft in the ventilation duct.

The hood works thanks to wind support - a vacuum appears above the cut of the air duct

Please note: in modern versions of TsAGI factory-made, insulation of the lower glass is provided if the cap is attached to the roof sandwich pipe. Under the “fungus” we see a skirt, although the flow area of ​​the channel does not decrease.

View #3 - Astato static-dynamic hood

The static-mechanical deflector is a development of the French company Astato . The device increases the draft of the exhaust flow of the natural ventilation system due to the wind and the fan.

The nozzle is mounted on houses of any number of floors, reconstructed and new buildings.

In passive mode, the vacuum level created by Astato is equal to the sum of wind and gravity pressure. This value corresponds to the operation of a static deflector

After turning on the electric motor, the aerodynamics of the ventilation duct are maintained, the degree of vacuum is the total value of the fan pressure and pressure.

Deflector characteristics:

1. Installation methods . Nipple connection for round ventilation ducts, through an adapter - for a group of air ducts or rectangular shafts.
2. Control modes . Manual regulation and automatic regulation are permissible - via a pressure sensor or time relay.
3. The material of manufacture is aluminum.
4. The lineup . The Astato deflector is available in six positions, with a nominal diameter of 16-50 cm.

Modifications of the DYN-Astato are equipped with a two-speed fan, the cost of products is 1300-4000 USD. depending on the dimensions of the deflector.

View #4 - DS series deflector

The open-type static nozzle DS looks like the Astato deflector. But, unlike the French cap, the DS series models do not have moving parts. The cap contains three conical disks.

The umbrellas of this type of deflector are truncated and located opposite each other, forming a channel similar to a Venturi nozzle. The diameter of the central hole of the lower disk corresponds to the cross-section of the pipe. Brackets hold the mesh

The highest speed of wind swirl is observed in the truncated channel of the hood - above the ventilation pipe. The pressure difference inside the deflector and remotely from it causes additional vacuum, which increases thrust.

Features of the DS series model:

• the deflector is compatible with forced means of inducing air exchange - fans;
• a wind flow speed of 5-10 m/s increases thrust by 10-40 Pa - the data is valid at a relative humidity of 50°, air temperature +25 °C and a wind flow deviation of up to 30° from the horizontal plane.

Deflectors are available in 13 standard sizes. Designation of ventilation hoods: DS-*** , where *** is the internal diameter in mm . The DS-100 model has the minimum dimensions, the DS-900 has the maximum dimensions.

Type #5 - rotary turbine or turbo deflector

The dynamic deflector consists of a fixed base and a rotating turbine head.

The elements of the spherical cap are made of light, thin metal, which allows the drum with blades to start working in light winds - from 0.5 m/s.

The head rotates in one direction of the wind vector. There is a “partial vacuum” under the hood - the air at the top of the ventilation duct is rarefied, the likelihood of the ventilation overturning is minimized (+)

Advantages of a turbo deflector:

• efficiency is 2-4 times higher than that of static models;
• protecting the premises from overheating in summer and reducing air conditioning costs in hot weather;
• aesthetic appearance - the deflector head is made in the form of an elegant spherical cap;
• preventing the appearance of condensation inside the roof by lowering the temperature in hot weather;
• economical operation - the active deflector operates without electricity.

The turbo deflector removes excess heat, moisture, dust, vapors and harmful gases from the shaft from the building and under-roof space, thereby increasing the service life of the structural elements of the house.

The disadvantage of an active deflector is zero performance in calm weather.

The marking of Aerotek products is presented as TV-160, etc. The digital index indicates the cross-sectional diameter of the fixed base of the cap

Dynamic nozzles are available in a wide range. The products of the following companies are in demand: Aerotek (Russia), Turbovent (Ukraine), Rotowent (Poland) and Turbomax (Belarus).

Can I do it myself?

Yes, it’s quite possible to make a homemade turbo deflector. True, let’s say right away that this work will be monotonous and long : you will have to cut several dozen plates from metal, and then assemble it all. In total, assembly can take a handy craftsman about a dozen hours at best. Therefore, in most cases it is better to spend 3-5 thousand rubles than to do the work yourself.

However, if you want to save money, or just like to do something with your own hands, we will provide step-by-step instructions. In practice, we will consider how to make such a part for a round air duct with a diameter of 160 mm.

Stages of creating a homemade deflector

What you will need:

1. Thick paper or thin cardboard - to create a sample (not necessary, but useful).
2. Metal - galvanized steel or stainless steel. Sheet thickness - 0.5-1 mm, size - about 1x2 m, or about the same (will come with a margin).
3. Flange for round air duct with a diameter of 160 mm.
4. M4 screws, self-locking nuts, rivets - according to the number of plates.
5. Bearing unit. The most important and difficult (in terms of searching) detail. You can either find a finished product in the store, or, as an option, take 2 couplings (25 mm) and a piece of furniture pipe.
6. Tools - drill with small drills, pliers, metal scissors.

Scheme of work step by step:

1. Cut out a circle with a diameter of 170 mm.
2. We cut out about 20-25 (not a standard number - you can do more) blades: long thin rectangles, 5x35 cm in size.
3. The blades are bent to the same radius. This stage is the most difficult: you will have to work only manually, and it will not be possible to accurately measure the result. To bend, you can take an emery wheel and a glass liter jar. Keep in mind that you still won’t be able to achieve an ideal result, so be prepared for errors right away.
4. The corners of the blades that will be attached to the coupling are bent at right angles (for holes for fasteners).
5. The bent plates are attached to the edge of the cut out circle.
6. The bearing assembly is assembled.
7. A circle with plates is attached to the bearing assembly.

Before starting to work with metal, it is advisable to make a drawing and “model” of a product made of paper or cardboard.

Photo instructions for creating a homemade turbo deflector, with dimensions (video)

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Can it be installed on a chimney?

By installing a deflector, unlucky homeowners are trying to solve the problem of lack of draft. This happens when the chimney pipe is made incorrectly - the head falls into the zone of wind support of the roof, is raised to a low height, or a neighbor has built a tall building nearby.

The best solution for insufficient draft is to raise the chimney to the required height. Why is it undesirable to jam various attachments onto the head:

1. It is prohibited to place umbrellas and other exhaust devices on pipes that discharge combustion products from gas boilers. These are safety requirements.
2. When burning, stoves and solid fuel boilers emit soot that settles on the internal surfaces of chimneys and caps. The deflector will have to be cleaned, especially the rotating one.
3. At the bottom of a properly constructed smoke channel there is a pocket for collecting condensation and excess moisture. There is no point in covering the pipe from precipitation; it is enough to attach a nozzle at the end that protects the insulation of the sandwich.

The heads of stove flues can be equipped with umbrellas, but a turbo deflector is definitely not needed there. The topic of installing hoods on smoke exhaust ducts is covered in detail in a separate material.

There can be no problems with traction

Ready to install rotary deflector

The purpose of any ventilation system is to remove polluted air and excess moisture from the premises, that is, to ensure normal air exchange. This will take place if the ventilation duct functions efficiently and correctly - the draft in it is excellent. If there are problems in this regard, they are often provoked by rain, snow, or wind masses entering the canal shaft. Also, poor draft can be caused by incorrect placement of the ventilation pipe, its insufficient height or incorrectly selected diameter of the air duct. The installation of a rotary deflector is designed to eliminate such shortcomings of natural ventilation.

Installation of a chimney on the roof

There are two options for installing the deflector: connecting directly to the smoke duct and mounting it on a piece of pipe, which is later put on the chimney. The second method is considered the best in terms of convenience and safety, because the most troublesome stage of the work is performed on the ground, and not on the roof.

Standards according to GOST

Excerpts from current regulatory documents regarding the installation of a deflector on a pipe inform about the following:

• any nozzles on the smoke channel must be mounted in such a way that they do not block the path of fuel combustion products;
• on a flat roof, the mouth of the pipe should be placed above the fence;

  There should be free space around the mouth of the pipe

• on a roof with slopes, the chimney head must be located above the ridge, if the space between them is less than one and a half meters, or at the level of the ridge, when the gap from the pipe to the highest point of the roof varies within three meters;
• the deflector must not be installed in an area where an aerodynamic shadow is created due to neighboring buildings;
• the device body must be well ventilated regardless of the wind direction;
• rotating deflectors are not suitable for chimneys of stoves located in houses built in areas with cold winters;
• installation of a round deflector on a brick chimney involves the use of special transition pipes.

Required Tools

To install the deflector on the smoke duct, you need to find some tools and fasteners:

• electric drill;
• open-end wrenches;
• threaded rods;
• nuts;
• clamps;
• two ladders (one for climbing to the roof, and the other for moving along the roof).

In addition, to install the device on the chimney you will need a piece of pipe. Its diameter should be slightly larger than the size of the smoke channel.

Deflector mounting

The chimney is connected to the pipe, performing certain tasks:

1. On the prepared section of pipe, 10 cm from the edge, mark the points where you need to drill holes for fasteners. Similar marks are left on a wide area of ​​the diffuser.
2. Holes are made in the pipe section and diffuser with a drill. The parts are temporarily connected to each other, checking that the upper and lower holes match. If this is not observed, then the product is considered defective, because the fastening elements cannot be inserted smoothly.
3. Pins are inserted into the holes. On both sides, both on the diffuser and on the piece of pipe, the fasteners are secured with nuts. They are twisted evenly to protect the product from deformation.
4. With the manufactured device they are sent to the roof. The structure is placed on the smoke duct and tightened with clamps.

If you install a deflector on a brick chimney, you will have to arm yourself with nails and a hammer

Proceeding as described above, you can mount any device except the weather vane deflector, since its design is rather non-standard.

In the case of using a device with a compass rose, 3 holes are created in the smoke channel with a drill. The holes are made at the same level so that bolts can be inserted into them a little later. These fasteners are immersed in the holes when the ring part of the deflector-vane is placed into the cut of the chimney. An axle is inserted into a bearing in the form of a ring, and a cylinder, a device blade and a cap are alternately attached to it. The elements of the weather vane deflector are combined with brackets or rivets.

The deflector can confidently be called a useful device that has a positive effect on the draft force in the chimney and the functioning of heating equipment. It is relatively simple to make and connect the device to the pipe; you just need to be “savvy” in choosing the type of deflector.

Turbo deflector dimensions

The device is quite popular, and therefore is used both in apartment buildings and other residential buildings, and in industrial facilities. In terms of diameter, the smallest is a 100 mm deflector. However, it can reach 1000 mm in diameter for large ventilation shafts.

The most common shape of the seat ring is round. However, transition bases can also be box-shaped or rectangular. They are often installed on buildings made of slabs, blocks or bricks. The area of ​​the landing ring should not differ by more than 15% from the diameter of the shaft or channel.