Forced exhaust for the chimney. Heat-resistant high-temperature fans Cheminair (Spain) and MMotors (Bulgaria) Exhaust fan for a fireplace

Site arrangement 20.06.2020

Site arrangement

Previously, draft and draft fans were used only in industrial boiler plants. The first are placed inside the chimney channel and create a vacuum, the second - they pump air into the furnace. Gradually, the units migrated to the domestic sphere - manufacturers began to equip heaters with a closed combustion chamber with turbines. The idea was picked up by home craftsmen, because the exhauster for the boiler helps to solve the problem of poor draft in the chimney pipe. Let's see if forced exhaust of combustion products is always necessary.

Design and principle of operation

An exhaust smoke exhauster for a factory-made boiler includes the following elements (the device is shown in the diagram, the positions coincide with the points):

Metal heat-resistant impeller with blades bent at 90° relative to the impeller.
Mounting plate.
Electric motor of low productivity (20 ... 50 W).
Power cable connector.
Console with controls and controls.
The flask and capillary tube of the temperature sensor connected to the emergency thermostat.
Mains cable with plug.

Note. As an example, a DM-01 boiler smoke exhauster from Kalvis is taken. The design of other types of fans differs in the shape of the case - a snail, a duct, a hemispherical landing site. The set of parts is the same.

The unit is attached to a special box located on the rear panel of a household TT boiler next to the chimney pipe. The temperature sensor flask is inserted into the immersion sleeve of the water jacket, the control panel is placed separately.

The principle of operation of the smoke exhauster is the forced removal of high-temperature gases from the fire-tube heat exchanger of the boiler into the chimney. The algorithm looks like this:

The firebox is filled with firewood, ignition is carried out.
The loading door is locked, the blower door is opened. The fan is turned on with a key on the remote control, then the performance is adjusted.
When the heating system and chimney have warmed up, the impeller speed is manually reduced to a minimum. If the heat generator has enough natural draft, it is recommended to turn off the smoke exhauster.
When the coolant is heated to a critical temperature of 100 °C or more, an emergency thermostat is triggered by the sensor, turning off the fan automatically.

Scheme of operation of the boiler smoke exhauster

Reference. On TT boilers equipped with an automatic one, the ash pan door does not need to be opened. The thermostat, by means of a chain, will open the air supply damper to the required angle.

High or low output of the draft fan is set individually depending on the quality of the solid fuel, the combustion mode and the degree of heating of the chimney. The main thing is to avoid the accumulation and seepage of smoke into the room.

It is also impossible to overdo it with revolutions - the lion's share of the heat will go into the pipe. Before opening the door and reloading, it is better to increase the rotation speed to the maximum.

Ready-made fan unit of the famous Russian brand Zota is mounted on wood-burning heaters with a rear outlet of gases

Varieties of draft fans

For and wood-burning fireplaces, several types of smoke exhausters are sold:

boiler room (design discussed above);
centrifugal channel;
overhead;
fireplace / stove (aka roof).

It should not be attributed to smoke exhausters various nozzles that improve natural draft - deflectors, round rotary elements and rotating weather vanes. The effectiveness of these hoods depends on the wind speed, which changes with the weather.

Varieties of channel smoke exhausters, some models are equipped with temperature sensors

The duct fan is distinguished by its own housing with two connecting flanges or nozzles. The unit is installed vertically or horizontally in the gap of the chimney channel. The device and principle of operation is similar to the operation of a boiler smoke exhauster.

The overhead smoke exhauster for a domestic boiler is equipped with a semicircular platform and clamps-screeds. Installation is carried out on a vertical section of the chimney (non-insulated):

According to the paper template, an opening is cut out in the pipe.
The impeller of the traction machine is inserted into the hole, the platform with the electric motor is pressed against the surface with clamps.
The connection is sealed with an asbestos cord glued to the inside of the smoke exhauster mounting platform.

Note. The overlay element is selected according to the diameter of the flue pipe. The installation process is shown in the video.

Electric hoods are mounted on the head of a brick chimney and fastened with spacer bolts. The power cable is laid through a pipe and introduced into the room next to the home stove.

To choose a traction machine, you need to focus on 3 criteria:

heat generator power, smoke exhauster models are designed for boiler capacity up to 20, 30, 50 and 100 kW;
installation point - on the boiler itself, pipe or head;
for overhead models - the diameter of the non-insulated flue.

Overhead (left) and roof smoke exhauster (right)

When you need a smoker

Manufacturers of heating equipment complete their products with traction fans due to the increased resistance of the heat exchanger, where gases change the direction of movement through the flame tubes several times. The goal is to take maximum heat from the combustion products and increase the efficiency of the boiler plant.

Nuance: the operation of the smoke exhauster in the boiler of the factory configuration is coordinated with the combustion process and is controlled by an electronic unit. When installing a fan unit on a "brainless" heater, such consistency is excluded, you need to buy an automation unit or adjust the speed manually.

Organize forced ventilation in the boiler room, and only then think about installing a smoke exhauster

We list situations when a smoke exhauster will help improve the operation and maintenance of a solid fuel heat generator:

traction problems - wind blowing, air jams in the gas duct, many turns, narrowing of the diameter;
due to the design features, the boiler smokes into the room when the door is opened;
the height of the chimney is insufficient or the cut of the pipe has fallen into the zone of wind support behind the ridge of the roof or another building;
cracks appeared in the brick chimney, from which smoke seeps.

An important point. Not a single fan will save the situation if there is no inflow from the street in the boiler room. At first, the working impeller will create a slight vacuum, but then the blades will begin to mix the air in place. - a prerequisite for the normal operation of any heater.

Mine heat generator V. G. Kholmov is better to operate with a traction fan

Some designs of wood-burning boilers (for example, shaft type) tend to emit smoke through an open loading hatch. A similar picture is observed in heat generators with a three-way fire-tube heat exchanger of increased resistance. The solution to the problem is the installation of a traction or blowing machine controlled by a controller.

Strengthening natural traction with a smoke exhauster has a downside. If, after warming up the pipe, the natural exhaust is not restored, the unit cannot be turned off - you can get burned. Now imagine that in the middle of the night the power went out, the fan stopped. As long as the chain thermostat closes the damper, smoke will fill the boiler room.

What is better - a smoke exhauster or a supercharger?

When the traction turbine is integrated into the heat generator by the manufacturer, these issues do not arise. Another thing is adding an exhaust fan to a conventional direct combustion boiler. It must be understood that in this case, the smoke exhauster solves only 1 task - creating a vacuum in the furnace and increasing traction. There are a number of negatives here:

Without an electronic control unit, performance will have to be adjusted manually. Automatic maintenance of the coolant temperature is excluded.
When air is supplied through the open door of the ash chamber, the fan will force the boiler to work at maximum. It will not be easy to set up the long burn mode.
In the event of an emergency stop of the impeller, the combustion of the fuel will not stop, since the gases pass freely through the volute or the smoke exhauster housing. Air enters the furnace, the likelihood of overheating increases.
The impeller and internal surfaces of the unit are covered with soot, which must be removed. The sticking speed depends on the humidity and resin content of the wood.

Comment. We do not mention the power consumption of the fan. The consumption is relatively small and will not have a significant impact on the overall cost of heating.

A blower fan with an automation unit performs the same functions as a smoke exhauster

The disadvantages described in paragraphs 1 and 2 are eliminated by switching the smoke exhauster with a controller that controls the speed of the impeller and the temperature of the water jacket. Electronic blocks can be bought at a price of 50-100 USD. e.

Blow machines always work in conjunction with the controller, so the above problems do not exist:

the supercharger changes performance and turns off at the command of the control unit, the coolant is heated to the set temperature;
during the combustion process, the ash pan door is hermetically closed, air is supplied through a separate channel;
in the event of a power outage, the air channel is automatically closed by a gravity damper;
impeller blades do not come into contact with hot smoke and soot.

Reference. In pyrolysis boilers, pressurization is always used, since the operation of this type of heater is based on forced air injection.

Now let's compare the cost of a draft fan and a blower fan, without taking into account the price of the controller. A smoke exhauster for a TT boiler up to 30 kW will cost 90 USD. e., supercharger - 60-65 c.u. e. The difference is due to the design features of the exhaust unit - hot gases should not overheat the electric motor, plus the impeller is made of metal (when pressurized, it is made of plastic).

Behind the mounting flange of the unit is a small impeller designed to cool the electric motor

In terms of installation complexity, the units are approximately the same. Installation of the injection snail involves cutting an opening in the ash pan door, a smoke exhauster - disassembling or cutting a pipe. It is easier to install a roof hood, but you will have to pull a long cable.

Brief conclusion: install a smoke exhauster only if necessary, or better, correct the mistakes made during the construction of the flue. Add an electronically controlled turbocharger at will - the system will automate and secure the combustion process.

How to make an exhaust unit

The main difficulty in assembling a smoke exhauster with your own hands is the manufacture of a balanced impeller, the rest of the details are not difficult for a home craftsman who knows how to weld. If the impeller blades vary in weight, normal fan noise will turn into rumble due to vibration.

In addition to the blades, you will need the following items:

electric motor with power up to 150 W, maximum shaft speed - 1400 rpm;
snail or homemade box shown in the drawing;
shaft with ventilation holes or additional cooling impeller;
studs with M8 nuts and other fasteners;
power cable.

We offer ordinary homeowners the least thorny path - to buy a factory electric motor with an impeller and a cooling impeller, weld a box and assemble a fully functional channel smoke exhauster for a TT boiler. How to do it right, look at the video.

Conclusion

The creation of artificial vacuum with the help of a smoke exhauster is rarely practiced in household solid fuel boilers. The technical solution leads to an increase in the cost of the structure and creates problems in operation. Before putting the draft fan on the chimney, remember what kind of fuel you used earlier. If you plan to burn damp wood, agricultural waste or low-quality briquettes, forget about the exhaust fan for the boiler, you will have to clean the impeller weekly. It is better to install a supercharger with a control unit.

The most important parameter of the chimney system is draft. Everyone knows that it is very important for the operation of a furnace or boiler, but few people know - what is draft? This parameter determines the speed and volume of movement of flue gases through the chimney. It is necessary for the removal of gases and the influx of oxygen to maintain the combustion process. The very phenomenon of thrust occurs due to the different density of cold and hot air. Hot is less dense, and is accordingly replaced by cold. This is how hot flows move from bottom to top.

These factors are the main ones, but not the only ones. Most often, the draft depends on the correct calculation of the chimney design - the optimal cross section and the number of corner elements.

Failure to comply with the above conditions is often the cause of poor traction. But how can this indicator be determined without special instruments and devices?

Determination of traction yourself

If the efficiency of the furnace (boiler) has noticeably deteriorated, then there are several ways to check the draft. You can use a special device - an anemometer, but in most cases, its purchase for home use is not economically efficient. It is best to resort to proven folk methods:

Candle. If you light a candle, bring it to the chimney and immediately extinguish it, then in the direction of the smoke you can see if there is a draft.
The degree of smoke in the room.
Thin sheet. The degree of its deviation may indicate the presence of traction.

Once the problem has been identified, you can begin to solve it.

Ways to improve traction

There are several ways to improve traction, and each of them is effective in its own way. But before proceeding with the implementation of one of them, a number of preventive procedures should be done with the chimney design itself:

Soot removal(). To do this, use a special set consisting of a ruff, a sinker and a steel cord.

Inside this structure is a ventilation system that creates an artificial air flow in the chimney. It creates a discharged air area inside the chimney, thereby improving the conditions for the occurrence of good draft. But for its installation, you will need to connect an electrical line, which is not very convenient, since in this case it will be necessary to comply with all safety regulations.

As can be seen from the foregoing, it is possible to improve the draft in the chimney, and this is done efficiently and quickly. But to choose the best method, it is best to take the advice of professionals who will carefully analyze the condition of the chimney.

The fireplace fan is capable of solving many problems. It is designed not only to improve draft in the fireplace, but also removes air from the stove well. With the same success it can be used in general ventilation systems.

Design features

Devices of this type come with horizontal and vertical smoke emission. For the manufacture of their body, galvanized steel or epoxy coated steel are used, which are not exposed to the environment. The design provides 2 impellers located on the engine, one of which is designed to remove smoke, the second - for self-cooling of the engine.

The fireplace fan kit may include an air flow regulator. This accessory allows you to choose the optimal engine speed in the following modes: ignition, constant fire, meat frying (for barbecues). This device is capable of operating in an environment from 0 to +200C.

The fireplace extractor is equipped with a single-phase or three-phase motor with an insulation degree F. It has a thermal protection system with an automatic restart function. It is equipped with an impeller, a characteristic feature of which is the presence of forward-curved blades. To ensure the longest possible life of the product, rolling bearings are provided in its design.

It is also important that the oven fan is equipped with lifting lugs. This helps to simplify the process of lifting it and installing it on the pipe from the fireplace as much as possible.

Principle of operation

Before igniting the fireplace, the smoke exhauster is turned on at maximum speed to displace cold air.

The smoke exhauster-fan is located horizontally on the roof or chimney. But it is important to consider the direction of the air flow. Also, for maintenance of equipment, it is necessary to provide unhindered access.

If you need a fan for a barbecue or a fireplace, products from the First Passage company are at your service. All presented products have been tested and meet the existing quality standards. We offer affordable prices and high quality service to each client. If you need a fan for a barbecue or a fireplace, products from the First Passage company are at your service. All presented products have been tested and meet the existing quality standards. We offer affordable prices and high quality service to each client.

RoomKlimat offers a wide range of ventilation equipment. The online store presents a large selection of fans from major foreign and domestic manufacturers. You can order heat-resistant fans Cheminair (Spain), BK (Bulgaria) from us at the most affordable prices in Moscow. All products are certified and accompanied by a service guarantee.

Application area

The heat-resistant fans Cheminair (Spain), BK (Bulgaria) sold by our company are used for equipping ventilation systems, air conditioning and air heating of various premises (for air supply and exhaust).

Such equipment is usually installed:

In saunas and baths;

In industrial premises;

When equipping fireplaces;

Etc.

All products are manufactured in accordance with high European quality standards, are reliable, and have excellent performance characteristics. Heat-resistant fans of trademarks Cheminair (Spain) and BK (Bulgaria) are made of high quality materials (carbon steel) with anti-corrosion coating. This ensures a long service life of the product and its resistance to aggressive environments.

You can buy heat-resistant fans of various types of Cheminair (Spain) and BK (Bulgaria) brands from us at the most affordable prices in Moscow.

You can order energy-saving duct fans Etaline from Ruck (Germany), as well as equipment and components from other manufacturers, both wholesale and retail.

Traction efficiency can depend on several parameters:

Failure to comply with the above conditions is often the cause of poor traction. But how can this indicator be determined without special instruments and devices?

Determination of traction yourself

Candle. If you light a candle, bring it to the chimney and immediately extinguish it, then in the direction of the smoke you can see if there is a draft.
The degree of smoke in the room.
Thin sheet. The degree of its deviation may indicate the presence of traction.

Once the problem has been identified, you can begin to solve it.

Ways to improve traction

Soot removal(read about it here). To do this, use a special set consisting of a ruff, a sinker and a steel cord.

To do this, you need to climb the roof and lower the ruff along the entire length of the pipe into the outlet of the chimney. Next, with translational movements, begin to clean the walls of the chimney. At the same time, layers of soot will begin to fall into the furnace, which are then removed.

Complete sealing of the chimney. Using one of the methods described above, it is necessary to check the structure for the absence of slots or holes. This problem is typical for brick chimneys, when during operation there is a partial destruction of the masonry.

If after these measures the traction has not improved, then more radical methods must be resorted to.

draft regulator

This device is installed on the outlet pipe of the chimney.

After pre-adjustment, it compensates the pressure in the pipe with the external pressure. In this case, not only the normalization of the operation of the heater takes place, but also the thrust speed has the same value, regardless of external weather conditions.

This additional structural element is also placed on the outer part of the chimney.

Its outer diameter is much larger than the section of the chimney itself. This is necessary for the occurrence of the effect of a pressure drop when the airflow flows around an obstacle. Those. when the deflector structure is surrounded by air flow, a low pressure area is created inside it, which contributes to the conditions for a better thrust speed.

Chimney weather vane

The original design, which can not only improve traction, but also protect the chimney from atmospheric precipitation.

Its operation is based on the principle of a deflector and the removal of flue gases only from the leeward side. This makes it possible to reduce the external air resistance and thereby normalize the thrust speed.

smoke fan

One of the most effective methods, which is to install a special fan on the chimney.

How to significantly improve chimney draft - from cleaning to fan
How to significantly improve the draft in the chimney - from cleaning to the fan The most important parameter of the chimney system is the draft. Everyone knows that it is very important for the operation of the furnace or boiler, but

An important condition for the full functioning of the furnace is normal traction, which will help to remove combustion products. This indicator is strongly influenced by the diameter of the chimney. If it is of a small cross section, then the products of combustion will not be able to go outside and will begin to accumulate inside the housing. In the case of using a wide chimney, cold air flows will not allow burnt substances to rise. All these and other nuances can be compensated by a traction booster, which can really be done independently.

Traction enhancement options

There are several types of devices that can increase the outgoing air flow. Among them, the most popular are:

Deflector . Structurally, it increases the diameter of the chimney at the outlet.
Vane . A device that is installed on the top of the chimney (turns against the wind), protecting its mouth from dust and protecting it from various precipitation.
Smoke fans . Most often they are installed on a fireplace chimney with a small cross section. They can be turned on when there is not enough natural wind flow.
Rotary turbines . Such devices are installed on the head of the pipe to provide free access to the wind. They are best applicable for gas boilers.

If the roof has a sharp slope or large objects are located near it, then these circumstances worsen the draft, which will help overcome the increase in the length of the chimney. But with a very long pipe, there may be heat losses, which will go not to heat the home, but to heat the cold street air. To prevent this from happening, special dampers are provided in the furnace that regulate the amount of exhaust gas.

Do-it-yourself deflector installation

The device optimizes air removal, being a reflective device. It will not be difficult to do it yourself - just arm yourself with the necessary tools and purchase sheets of galvanized metal. Their thickness should be no more than 1 mm.

The simpler the design of the deflector, the more accurate the drawings will be and the more efficient the device. You don't need to come up with an intricate shape. For example, the most elementary scheme is taken. Dimension D is the diameter of the pipe with a small gap so that the deflector can be securely fixed on it. Di - twice the cross section of the chimney.

roulette,
electric drill,
clamps,
hammer,
square,
metal scissors, hacksaw or grinder,
riveter,
heat resistant mastic
self-tapping screws,
fastening parts.

After preparing the tool, you can start working:

Apply the dimensions of the workpieces to the sheet of metal. Cut them out.
Roll the future body of the nozzle into a ring and fasten its edges with rivets or self-tapping screws.
Assemble the chimney cone in the same way.
Combine both items. For better sealing, treat their joints with mastic.
Build a metal umbrella and fasten it on top of the deflector with studs or rivets if it is made on the legs.
Strengthen the stability of the structure by applying clamps.

The result should be a durable traction booster that can withstand wind and precipitation.

Useful related articles:

Wind vane to increase traction

This amplifier, unlike the previous one, can rotate around the chimney. The principle of operation of the device lies in its response to air currents, as a result of which, from any breath of wind, the traction amplifier takes the appropriate direction. Air is blown into special gratings, which creates a constant vacuum in the pipe.

The demonstrated product can work in any weather conditions. It reacts even to the slightest breeze. The invented device improves the efficiency of the combustion boiler by about 20%. If you install it on a pipe, then you will not need to make the chimney very long, you can shorten its visible part above the roof.

Electric fans

Powerful fans that are used for fireplaces and wood-burning stoves. They are designed to work in a hot environment, where there is a lot of ash and other combustion products.

The body of such devices is made of galvanized steel with a specially applied polymer coating, which provides it with protection from aggressive environments. It has a protective grill that prevents various large and medium-sized objects from entering the air duct.

The ventilation device is powered by a single-phase motor, which can ensure uninterrupted operation of the system in any weather. Although it has protection from the flow of hot air, it is placed outside the zone of its movement for safety reasons. It has ventilation holes and a special wheel that prevents soot and dust from sticking.

Such a ventilated system is fully automated. It has built-in temperature sensors, as well as their counterparts that regulate the strength of the air flow. They are triggered by deviations in the operation of the electric motor and create the optimal traction of the device.

Rotary turbines

Their principle of operation is similar to the deflector - they are also located at the top of the pipe and use wind energy. The nozzle, on which the grids with wings are located, rotates in one direction, regardless of the direction of the wind. Due to its movement, it creates the necessary air rarefaction. The design of the device resembles a dome and is able to protect the chimney from debris and precipitation. It is designed for gas boilers and ventilation ducts. Not recommended for solid fuel boilers and fireplaces.

In calm weather, this amplifier does not work, but in the summer, when the boiler is not functioning, it can create a very strong draft, which is often superfluous.

Strengthening the draft in the chimney with your own hands
It is possible to increase the draft in the chimney not only by extending the pipe, but also by a special device - a deflector, a weather vane, electric fans and rotary turbines.

Causes of poor chimney draft

From time to time, fireplace owners note a deterioration in the performance of their heating device. With what it is connected, naturally, they do not know. Experiments with the replacement of fuel, usually, also lead to nothing. Experts say that the reason for the poor performance of the fireplace is weak draft.

Causes of poor chimney draft

Pipe diameter too large or too small. The pipe must be the correct size. If its diameter exceeds certain norms, then reverse thrust occurs. Bring the fan to the chimney, if its blades start to move, then you have a reverse draft. Too narrow a pipe leads to a decrease in thrust to critical levels.
Rotary elements and bends in the pipe. The chimney must be straight, otherwise you will have to install a chimney draft amplifier. Extra turns and bends significantly reduce this parameter.
Lack of tightness. This problem is often found in brick fireplaces as a result of broken construction technology. When a small hole appears in the wall, it begins to work like a black hole, sucking in air due to the pressure difference. The presence of additional air negatively affects the traction force. This is the same as putting a fan on the side of the air going up.

Smoke deflector

Types of amplifiers

Deflectors- These are aerodynamic devices that specialize in deflecting air currents. With their help, you can adjust the traction force to the required parameters. The deflector fan works on a very simple principle: it sucks in air from the atmosphere and directs it into the chimney. The disadvantage of the device is its absolute helplessness in a quiet hike without wind.

The most common and effective deflectors are the designs of Grigorovich and Volpert. At the heart of modern improved deflectors are their prototypes. The most common designs are round chimney nozzles (“Woplers”), star-shaped (“Shenards”) and H-shaped (multi-tiered). When choosing a deflector, carefully look at the material from which it is made. It should be stainless steel - a material that is durable and reliable.

Rotary smoke draft turbines

Rotary turbines- these are mechanisms that are placed on top of the chimneys. By the principle of operation, they resemble a fan, since they use wind energy to increase the pressure inside the pipe. Advantages of rotary turbines: they close the chimney pipe and prevent the ingress of precipitation. The device does not work in calm weather.

It is also necessary to ensure that the temperature of the outgoing gas does not exceed the threshold of 250 degrees (these are standard requirements that may differ for different models). Rotary pipes are installed for gas-fired boilers.

Chimney weathercocks- This is a device for protecting the chimney from the leeward side. The model is distinguished by good resistance to the negative effects of precipitation, a long service life and the presence of protective mechanisms for the chimney. During the operation of weather vanes, one of their drawbacks was noted: they cannot cope with strong winds, and weather vanes also require careful maintenance - regular lubrication (especially in winter) and cleaning from soot and flue gases.

The weather vane fan works on the principle of a stabilizer: it reduces the effect of strong wind on the draft in the chimney or enhances it in the absence of movement of gas masses in the atmosphere. The type of device in question is great for wood-burning fireplaces.

smoke exhausters is an electric heat-resistant chimney fan. It is recommended to install these devices for adjusting the traction force only for narrow pipes. For its operation, access to an electrical network with a power of 220 V is required. Modern smoke exhausters have several upgrades that solve the problems of reverse and weak draft. The electric mechanism has no drawbacks, it works great in quiet and windy weather.

Caps and umbrellas- these are decorative elements for a chimney that do not solve the problem of weak draft. After their installation, the owners of heating devices noted additional problems: the formation of condensate on the surface of caps and umbrellas, as a result of which the fan of the above devices quickly became unusable.

Thus, a wide variety of mechanisms for enhancing traction cope well with the problem posed. The above models, except for smoke exhausters, have one drawback in common: they are too dependent on weather conditions. Therefore, to increase the draft in the chimney, it is better to choose an electric smoke exhauster.

Manufacture of devices for traction enhancement

Making do-it-yourself traction amplification devices

It’s good when a person has money and can buy a few chimney nozzles for himself, but what if there is no opportunity to get a modern mechanism, however, there are tools and several metal plates in the garage? The answer is simple - design your own.

From the tools you will need: a square, metal scissors, a tape measure, a hammer, pliers, a drill, self-tapping screws (15 mm), a galvanized sheet of metal with a thickness of 0.3-0.5 mm and a few improvised materials for fastening and an old fan, more precisely, its blades.

Draw a layout of devices to enhance traction

The first thing to do is to draw a layout of the future device. Schematic drawings can be found online. After accurately transferring the dimensions to a sheet of galvanized steel, the following actions are performed in strict sequence:

Using a grinder or scissors for metal, the main parts of the weather vane are cut out,
The constituent elements of the weather vane are assembled according to the scheme in strict sequence and fixed with rivets or self-tapping screws,
Next, you need to fix both cones (in most schemes, this item is skipped, since the "masters" believe that it can be ignored). In fact, this item is highly recommended not to be ignored, so as not to provoke cone breaks in strong winds,
Now it remains to put fasteners and a fan on the device. With the help of fasteners, the device is attached to the base of the chimney. The fan also performs the function of enhancing traction.

At this stage, the manufacture of the weather vane is considered complete, it remains only to attach it to the chimney. It is fastened with screws or rivets. Remember that this device needs regular maintenance: from time to time it must be cleaned of soot and accumulated condensate, if you do not want the accumulated moisture to fall on the waterproofing layer inside the pipe.

Ways to increase traction in heating devices
Despite its complete autonomy, the air circulation is often disturbed by fireplaces, because of which its performance suffers, a chimney draft amplifier can solve this problem.

Chimney fan.

Chimney fan- a device for the forced creation of draft in the chimney. A chimney (chimney) is a device for removing gaseous products of fuel combustion from the furnace and dispersing them in the atmosphere at a safe height. The simplest chimney is a pipe fixed in a vertical position. A channel is connected at the bottom of the chimney to remove combustion products from the furnace.

The chimney is made of a material with low thermal conductivity or covered with the necessary layer of thermal insulation.

Removal of gaseous products of combustion is carried out due to Traction is the product of the difference in the densities of atmospheric air of hot exhaust gases and the height of the pipe. The density of hot gases is much lower than the density of atmospheric air. Moreover, the higher the temperature of the exhaust gases, the lower their density and the stronger the thrust.

Fuel, burning in the furnace, gives off thermal energy to the coolant or heat emitter. Typically, the temperature of the exhaust gases is ≈ 180 - 200 Gy.S. Heat carried away by exhaust gases through the chimney into the atmosphere inevitable losses - payment for "good traction". Moreover, the greater the power of the heat-producing installation, the greater the loss. These losses can be reduced (minimized) by cooling the exhaust gases to ambient temperature. But with equal temperatures of atmospheric air and exhaust gases thrust will disappear.

To artificially create draft in the chimney, after all the devices that reduce the temperature and purify the exhaust gases, a fan is installed - smoke exhauster. Smoke exhausters can be of various designs, but usually they are centrifugal fans with a frequency speed controller and a special suction guide vane.

However, a smoke exhauster can also be useful for small-capacity heat generators, especially those operating on solid fuels. Everyone is well aware of the situation when it is impossible to ignite the fuel, after a long break in operation, in the case of equal temperatures of the heat generator structures and atmospheric air. Naturally, for the efficient operation of the gas-air path of the heat generator, it is necessary to perform appropriate calculations.

What is a chimney fan? When should it be used?
Chimney fan. Chimney fan - a device for forced draft in the chimney. A chimney (chimney) is a device for removing gaseous gases from the furnace ...