Snail fan: types of centrifugal coolers, how to choose a high-pressure air hood

Fan device and design

Radial fan operation diagram

Sometimes an impeller and a power unit are not enough to move air. In conditions of limited space, a special type of exhaust equipment design should be used. It has a spiral-shaped body that acts as an air channel. You can make it yourself or purchase a ready-made model.

To form the flow, the design includes a radial impeller. It connects to the power unit. The wheel blades have a curved shape and create a discharged area when moving. Air (or gas) enters it from the inlet pipe. When moving along the spiral body, the speed at the outlet increases.

Depending on the application, the centrifugal fan volute can be general purpose, heat-resistant or corrosion-resistant. It is also necessary to take into account the amount of air flow created:

• low pressure. Area of ​​application: production workshops, household appliances. The air temperature should not exceed +80°C. Mandatory absence of aggressive environments;
• average pressure value. It is part of exhaust equipment for removing or transporting small fraction materials, sawdust, grain;
• high pressure. Forms an air flow into the fuel combustion zone. Installed in many types of boilers.

The direction of movement of the blades is determined by the design, and, in particular, by the location of the outlet pipe. If it is located on the left side, the rotor should rotate clockwise. The number of blades and their curvature are also taken into account.

For powerful models, you need to make a reliable base with your own hands to secure the body. The industrial installation will vibrate strongly, which may lead to its gradual destruction.

Types of impeller

The fan performance will directly depend on the shape, size and material of the impeller. It is also necessary to take into account the number and shape of the blades responsible for pumping pressure inside the cochlea. The main requirements for the material of the impeller and blades are corrosion resistance and ductility. Such a working body will withstand the chemical influences of an aggressive environment and increased vibration loads.

When choosing the shape and number of blades, aerodynamic loads and rotation speed are taken into account. When using powerful engines, the metal blades must be bent at right angles, which allows the formation of a stable air flow. But for low-power fans, it is preferable to use large straight blades, which make it possible to provide high pressure in large-sized volutes.

A well-made wheel should not vibrate during operation, as this can lead to rapid failure of the unit. Fan vibration increases the noise level, destroys the installation base and negatively affects the overall durability of the equipment. Oscillatory movements can be minimized by carefully balancing the shaft or using special shock-absorbing springs. They are mounted under the base of the housing, allowing them to dampen longitudinal and transverse parasitic vibrations of the unit.

Features of the snail hood

The memorable shape and distinctive operating principle make this type of ventilation stand out from similar ones. The most popular snail will be for rooms with a minimum area and free space. The design of the fan in the form of a spiral serves as an air duct in any warehouse or industrial premises.

There are different configurations available for your choice, but if you wish, it is quite possible to build a cleaning system with your own hands. How to install a snail and why is it better than other cleaning systems? The answers to these questions lie in the structural features of the device.

Snail design

A standard volute (umbrella) consists of an impeller and a power unit. Your fan, depending on its assigned functions, may have protective properties against corrosion or be characterized by increased heat resistance.

The structure of the snail is selected directly for the room in which an additional cleaning system should be installed. When choosing a device, it is recommended to take into account the strength of the air flow, namely:

• low pressure flows;
• average pressure;
• high pressure flows.

When choosing a “Snail” fan, you should take into account the strength of the air flow

Professionals warn that the more powerful the ventilation unit, the more effort should be put into installing it. A homemade box or base will facilitate quick connection and correct operation of the entire device for a long time.

Description of equipment

Centrifugal fans are characterized by excellent efficiency, which is achieved due to the rapid rotation of a radial wheel with numerous blades. The working element is located in a spiral chamber, which ensures the highest possible air injection efficiency. The blades on the wheel are made curved, straight or in the shape of a bird's wing. Accordingly, the size of the equipment, its performance and purpose vary.

Depending on the air flow pressure indicators, it is customary to distinguish three classes of centrifugal fans:

• low pressure;
• medium power;
• heavy duty installations.

The pressure indicator can vary in the range of 0.1-12 kPa. The performance of the equipment will depend on the profile and number of blades, as well as on the electric motor used, which is responsible for rotating the working element. On sale you can find both fully mechanical devices and installations that are controlled automatically and have expanded functionality.

All snail coolers used today can work both to blow in and remove air from the room. To change the direction of rotation of the impeller, the phases of the current at the motor terminals are swapped. This is done using the corresponding switch toggle switch on the device control unit. Some models of ventilation equipment have the ability to change the rotation speed, which allows you to adjust the performance of the blowers.

Homemade snail

Before starting to create a homemade system, craftsmen recommend deciding on the functional purpose of the future device. A centrifugal fan, that is, an umbrella made from simple available materials, is suitable for partial cleaning of premises or complex equipment.

In cases where a do-it-yourself snail fan is intended for boilers, the body of the device must be made of heat-resistant steel sheets. A home-made centrifugal fan is made from old parts of a vacuum cleaner or cleaning system of a residential building. Fans such as a snail or an umbrella will serve well in small workshops, but for large-scale enterprises such devices will be of little use.

The entire process of creation and subsequent connection of the fan takes no more than two days, taking into account fast and high-quality work at all stages. First, calculate all the parameters of the future device, including the outer box and insulation. It would be a good idea to consider the option of additional gaskets that reduce the vibration effect from the operation of the snail device.

Homemade “Snail” fan is made from improvised materials

Next, the centrifugal fan is assembled from scrap materials or parts of an old device. Metal sheets or plastic are suitable for such purposes. Installation of the power unit requires special attention, so at this stage time is devoted to choosing a shaft or drive. The installed cooler will ensure timely cooling of the unit, extending the life of the entire device.

The centrifugal fan is mounted in the outer casing and mounted on a fixed base.

You can use a simple circuit to make and then connect a homemade device called an umbrella, supplement it and equip it with all the necessary elements for working in a given room. The main thing is to comply with all fire safety standards and use the snail for its intended purpose.

Centrifugal fan: equipment design

Ventilation systems equipped with this equipment have high potential even in difficult climatic conditions. A centrifugal fan is a structure consisting of several components:

• spiral body;
• impeller;
• impeller blades;
• electric motor.

All parts of the structure are connected by spot welding, rivets and bolts, which ensures reliability. The centrifugal fan often has a powder-coated stainless steel housing, which minimizes the possibility of corrosion. Indicators such as efficiency and vibration level depend on the direction of blade bending.

Tywent WBN 130/1 – for small spaces

Centrifugal (radial) drum-type fan. The working body is enclosed in a steel casing, made in the shape of a snail. High-strength steel was used to make the wheel and blades. An additional protective coating is a polymer applied using the polyester method and heated in an oven.

The power device is a single-phase synchronous electric motor 220 volts. Used to work together with a general ventilation system. The mount is stationary.

Pros:

• Small in size, efficient, easy to install.
• The use of steel for the body and blade drum plus a polymer protective coating.
• Acceptable cost with appropriate build quality and technical characteristics.

Minuses:

• It’s impossible to stand nearby for a long time; your head begins to buzz from the noise.

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Centrifugal fan: operating principle of the design

The popularity of this equipment largely depends on efficiency and economic feasibility. The centrifugal fan is designed in such a way as to maximize these indicators.

The air, falling on the blades, is deflected at an angle of 90 0. Then it passes through the spiral casing of the centrifugal fan and only then enters the room. Thus, the most efficient circulation of air flows in the room is achieved.

You can buy a fan in our online store. Our catalog contains a large selection of different models: axial centrifugal air fan, centrifugal exhaust air fan, etc. Here you can easily choose a suitable centrifugal fan, the characteristics, price and quality of which will meet your requirements. We give our clients the opportunity to buy a centrifugal fan at a profit - the cost of the equipment will pleasantly surprise you.

Fans for extracting air masses are distinguished by design.

They have a cylindrical shape; a blade ventilation system is mounted inside the cavity, driven by an electric motor. With this design solution, the air passes along the axis of the device. A manifold is installed at the inlet, which is necessary to improve the aerodynamics of the entire device. Among the advantages of this type of exhaust device, the efficiency should be highlighted - over 100 m³ per hour of operation.

Plus, the exhaust fan is characterized by simple installation, so it is often installed in the fan. openings of kitchens and bathrooms. The only disadvantages include high noise level of about 30-50 dB and low pressure.

Radial exhaust fan

They have a “spiral” type housing, inside of which a wheel is placed. When this wheel rotates, the air masses move in the radial direction, the mass is compressed under the influence of centrifugal forces and is removed from the housing.

The blades of the device are directed both forward and in the opposite direction; in the first case, the savings will be up to 20% of electricity. Plus, the noise of the device will decrease significantly. Blades curved forward increase power. Radial modifications of ventilation systems are characterized by their small dimensions, ease of installation and versatility.

Centrifugal exhaust fan

appeared on the market quite recently, the model has already gained enormous popularity among the user community. Centrifugal force fans for exhaust are excellent for installation in rooms with an area of ​​more than 15 m²; they have good power characteristics and almost silent operation. The advantage of centrifugal systems is that it can be installed both in front of the air intake and in the middle of the shaft.

Engineers have also developed specialized units for forced smoke removal with an explosion-proof function. Axial smoke removal systems are designed to send out air masses that are full of harmful and explosive impurities.

An explosion-proof axial type fan is necessary, first of all, to organize forced exhaust of air masses containing explosive impurities. The use of such devices in everyday life is extremely rare, but in woodworking and other industries where there is a risk of explosion and fire, they are ubiquitous.

Exhaust fan with check valve

Types of centrifugal radial fans

There is no fundamental difference in design between radial fans. They are divided into several types according to purpose and power.

By power

The working pressure that the volute hood is capable of depends on the engine power of the device, the number and configuration of the impeller blades.

There are 3 types of radial fans according to this parameter:

• Relatively low pressure devices (up to 100 kg/cm²). These are small fans used to create forced ventilation in residential buildings, labeled as BP 80-75. In apartment buildings, such devices are mounted on the roof, in a common ventilation duct.
• Devices that operate in the medium pressure range from 100 to 300 kg/cm². They are used in ventilation systems of production workshops without special safety requirements. The general marking of hoods of this group is BP 300-45.
• Powerful (working pressure in the range from 300 to 1200 kg/cm²) snail hoods are installed in hazardous industries where there is a need for intensive removal of caustic, flammable and explosive gas mixtures. The general marking of this class is VR 12-26.

Which fan should be chosen for a given ventilation system is influenced by many parameters: the length of the channels, their branching, throughput, and the required air exchange rate per unit time. Such calculations are carried out by specialists at the design stage of the ventilation system.

Note! Centrifugal fans are installed not only for exhaust, but also for air supply, for example, in boiler rooms.

By purpose

The second classification system for radial fans divides them according to their purpose:

• General purpose snail hoods. They are operated at temperatures up to +80 degrees in an atmosphere where there are no specific or dangerous contaminants. Installed in residential or industrial sectors.
• Explosion-proof - the body and parts of the mechanism are made of materials that prevent the occurrence of sparks during operation. Used in rooms where there are explosive gas mixtures. The permissible operating temperature range is from -30 to +40 degrees.
• Fire-resistant or heat-resistant hoods are installed in industries that use increased temperature in the technological process. The devices are made of carbon steel and coated with heat-resistant compounds. Operate at temperatures up to +200 Celsius.
• With enhanced anti-corrosion protection. These are fans that are installed in chemical plants with aggressive environments.
• Dust (marked VRP) – fans for removing air masses with suspended particles. The devices have a larger gap between the housing and the impeller and a reduced number of blades so that the device does not become clogged with waste during operation. Design features here lead to a drop in the efficiency of the device. It is necessary to choose a hood with a reserve of operating power.
• For smoke removal (marking VRDU). These fans are installed to remove smoke if a fire occurs. The devices operate in the temperature range of 400-600 degrees.

Housing material

The purpose and power indicators of the device will largely depend on the material from which the cooler is made. The industrial volute for ventilation is made of steel and other heavy-duty alloys, taking into account the degree of aggressiveness of the environment of use. Fan models designed for operation with non-aggressive gas mixtures and oxygen can be made of carbon and galvanized steel.

When the device is used to move aggressive gas mixtures and acids, it is necessary to choose chemically resistant steels, which ensures reliable and trouble-free operation of the equipment.

Standard modifications of exhaust fans are designed for use with air masses and gases whose temperature does not exceed 90 °C. On sale you can find highly specialized models used to work with gases with temperatures up to 200 °C. Such units are made of special heat-resistant steel, which is resistant to acids.

There is also an explosion-proof version of the hood, made of aluminum, copper alloys and other ductile metals. These snails use a special electrical wire that eliminates sparking, which is the main cause of explosions and fires.

If it is necessary to use centrifugal fans in conditions of high humidity, modifications protected from corrosion processes are used. The volute body is made of special galvanized steel, and the presence of rubberized gaskets prevents the penetration of moisture into the protected housing where the electric motor and control automation are located.

If the technological process involves active dust formation and the presence of sawdust and other mechanical mixtures in the air, then it is not possible to use standard modifications of radial fans. It is necessary to choose special dust-proof installations that do not have an additional front disk on the impeller, and the number of blades on the shaft reaches 6-8 pieces.

Another feature of this type of equipment is the presence of a large gap between the suction port and the impeller. This design allows you to cope with dust without reducing the efficiency of the equipment.

General information about centrifugal (radial) fans

Coil fans have a dual designation (marking): VR and VC, that is, radial and centrifugal. The first indicates that the blades of the working part of the equipment are located radially relative to their rotor. The second is the designation of the physical principle of operation of the device, that is, the process of intake and movement of air masses occurs due to centrifugal force.

It is centrifugal fans in ventilation systems that have shown themselves on the positive side due to the high efficiency of air removal.

Operating principle

As already mentioned, fans of this modification operate based on the action of centrifugal force.

1. The blades attached to the rotor of the device rotate at high speed, creating turbulence inside the housing.
2. The inlet pressure drops, which causes the suction of nearby air, which rushes inward.
3. Under the action of the blades, it is thrown to the periphery of the space, where high pressure is created.
4. Under its action, the air flow rushes to the outlet pipe.

This is how all centrifugal models work, which are installed not only in ventilation systems, but also in smoke removal systems. About the latter, it must be said that their body is made of aluminum alloy or steel, coated with heat-resistant materials, and is equipped with an explosion-proof electric motor.

Design Features

As already mentioned, the main design feature is the snail. It is also necessary to indicate the shape of the blades. Fans of this brand use three types:

• with straight slope,
• with a backward tilt
• in the form of a wing.

The first position is small fans with high power and performance. That is, they can create conditions in which other models require a large body. At the same time, they operate with low noise levels. The second position is an economical option that consumes 20% less electricity than other positions. Such fans can easily withstand loads.

As for the design that relates to the electric motor, there are also three positions:

• the rotor is fixed directly to the motor shaft through a coupling and bearings;
• through a belt drive using pulleys;
• The impeller is mounted on the electric motor shaft.

And one more feature is the connection points between the fan and the air ducts of the ventilation system. The inlet pipe has a rectangular hole shape, the outlet is round.

ERA D 125 (STELS 125) – modular assembly

Supply and exhaust fan. The direction and purpose are determined during installation - by connecting the inlet or outlet hole to the mating flange. The body is made of steel coated with protective enamel. The terminal box is enclosed in a sealed casing.

The single-phase electric motor and external rotor are mounted on a separate, folding platform. This provides easy access for inspection and routine operations. The centrifugal fan is used for duct installation.

Pros:

• Regular, channel, works, good power.
• Protective coating of the housing.
• The engine and rotor are assembled on a separate opening lid.

Minuses:

• Careful installation is required; distortions and blockages will cause vibration and loud noise later.

How does a snail hood work?

The device operates from the mains. Sizes range from household (main body diameter 25 cm) to industrial (diameter 150 cm).

The fan “rakes” air with small blades that rotate at high speed. The air flow is directed into the housing, makes a turn and is removed into the outlet hole. Passing through the curls, the flow loses speed and creates pressure.

Note! If the fan inlet is hermetically connected to a closed channel, then the volute hood will work like a vacuum pump.

Supercharger sizes

The dimensions of snail fans vary significantly. You can choose a snail for an air conditioning system in a private home, or purchase powerful, productive industrial units. Hood sizes vary from 250 to 1500 mm. Depending on the dimensions and intended use, the fan can be manufactured as a single product or have a modular design with main components that can be easily replaced. The latter option allows you to modernize the equipment used at minimal cost.

Self-production

radial fan for boiler

First of all, you should decide on the functional purpose of the centrifugal fan. If it is necessary for ventilation of a certain part of the room or equipment, the housing can be made from scrap materials. To complete the boiler, you will need to use heat-resistant steel or make it from stainless steel sheets yourself.

First, the power is calculated and the set of components is determined. The best option would be to dismantle the snail from old equipment - a hood or vacuum cleaner. The advantage of this manufacturing method is the exact match between the power of the power unit and the body parameters. A snail fan can be easily made with your own hands only for some applied purposes in a small home workshop. In other cases, it is recommended to purchase a ready-made industrial-type model or take an old one from a car.

Procedure to make a centrifugal fan with your own hands.

1. Calculation of overall dimensions. If the device will be installed in a confined space, special damper pads are provided to compensate for vibration.
2. Manufacturing of the body. If there is no ready-made structure, you can use plastic sheets, steel or plywood. In the latter case, special attention is paid to sealing the joints.
3. Installation diagram of the power unit. It rotates the blades, so you need to choose the type of drive. For small structures, a shaft is used to connect the motor gearbox to the rotor. In powerful installations, a belt type drive is used.
4. Fastening elements. If the fan is installed on the outer casing of, for example, a boiler, mounting U-shaped plates are made. With significant power, it will be necessary to make a reliable and massive base.

This is a general scheme according to which you can make an exhaust functional centrifugal unit with your own hands. It may change depending on the availability of components. It is important to comply with the requirements for sealing the housing, as well as to ensure reliable protection of the power unit from possible clogging with dust and debris.

The fan will make a lot of noise during operation. Reducing this will be problematic, since vibration of the housing during the movement of air flows is almost impossible to compensate with your own hands. This is especially true for models made of metal and plastic. Wood can partially reduce background noise, but at the same time it has a short service life.

In the video you can see the process of manufacturing a case from PVC sheets:

Fan selection

Axial ceiling, wall and duct fans are able to clean sanitary rooms of any size from unpleasant odors and humidity. Before choosing a fan for bathroom ventilation, you need to know the parameters by which they need to be selected. So, let’s look at the example of popular models that meet all sanitary and hygienic requirements.

Fan model for a large ventilation duct

For example, overhead wall/ceiling fans Vents 100 Quiet. They are installed directly in the ventilation duct - the diameter of the devices is 100 and 125 mm. It is possible to install it in a flexible air duct using a clamp. Some models are fastened with screws, others do not have fastenings. The body is made of high-strength, waterproof plastic. The blades are aerodynamic. All components subject to vibration during operation are made of rubber, which reduces the noise level. The engine is on ball bearings. There is a timer - from 2 to 30 minutes. Productivity – 100 cubic meters/hour. The same parameters are available for axial fans, which can be mounted both in the wall and on the ceiling, MEROX W 100 BN and Electrolux E AF-100.

Axial duct fans are used for installation in an air duct. For a clear example, consider a ventilation fan for a private house or apartment Soler&Palan TD-Silent. It has a reduced noise level. To facilitate installation and maintenance, the device is equipped with mounting brackets. In addition, the presence of such devices allows you to mount it not only on a horizontal surface, but also on a wall. Quick release clamps have rubber seals. The terminal box rotates 360°. The Vents TT 100 duct fan has similar parameters.

The main parameter for choosing a fan is its performance. The required indicator is easy to calculate, knowing the area, ceiling height and air exchange rate of the room. Multiplying these values ​​will give you the required fan power.

How to make it yourself

One of the features of such snails is their different price range. The minimum price for a snail hood will be about 3 thousand, but such devices, as a rule, are not very powerful and are very limited in size. The average price of a high-quality unit will exceed 20 thousand rubles.

Therefore, for domestic needs, it is more advisable to make a homemade snail for extractor hood. The standard design of such a housing will consist of two parts: the engine will be located in one zone, and the blowing blades in the other .

The casing for the snail can be purchased at hardware stores. If you are going to make it yourself, purchase the motor and other parts in advance, since the dimensions will have to be adjusted. It is better to make the case from metals (for example, aluminum and steel). Plastic will be less resistant to mechanical damage, and wood will quickly catch fire in the event of a malfunction.

The fan in such a system will operate at high speed. Therefore, incorrect design of the hood can have bad consequences. Check the quality and reliability of not only the base itself and fastening mechanisms, but also the motor, impeller and fan.

The fan dimensions are selected taking into account the area and degree of contamination of the room. Industrial designs are large.

Important! When installing the motor inside the box of such a hood, make sure that the design includes cooling holes. High temperature stress on the system can lead to an explosion.

Pay special attention to the choice of internal materials. Fan operation can be affected not only by temperature, but also by the power of air flow, the amount of debris and dust.

When air with large impurities is sucked in, the blades of the rotating wheel may be damaged. And in order to thoroughly clean the air, the unit must operate at high speed and under high pressure - this creates additional stress on the entire internal structure. Therefore, it is better to choose parts made of durable materials, such as steel or aluminum .

Compliance with the following recommendations will allow you to create a high-quality and safe hood with a long service life:

• choose the right size and power of the motor : take into account the maximum load on the structure, as well as the required operating speed of the hood;
• When mounting such a system vertically, carefully check the reliability of the fan and wheel fastening : with rapid air flows, they can jump off or change their location;
• materials adjacent to such a hood must be fireproof , as are all parts used in its assembly;
• observe the proportions between the individual hood zones : in the standard models offered in stores, the optimal ratio of the length and width of the structure is taken into account;
• If you are not sure that the assembled hood is safe, contact specialists who will check its serviceability .

Please note that hoods are rarely used in living rooms . Firstly, they take up a lot of space, and secondly, in rooms like a kitchen, the flow of polluted air can have different directions, so it is best to install such a hood in a ventilation shaft, where all the air coming from the apartment is concentrated.

The design of such structures will also play an important role in living rooms, but it is not diverse and does not always harmonize with the interior.

Tip: When placing such a hood in an open environment (outdoors), make sure that weather conditions will not affect its functionality.

Ventilation hoods can be used not only for air purification . In domestic conditions, they will do an excellent job of heating the room, and will also affect the humidity in the room .

The cost of equipment intended for domestic and industrial needs will differ significantly, but, in any case, such units have sufficient power for full operation.

For an example of designing a snail hood, see the attached video.

What to consider when purchasing an exhaust fan

its following characteristics

Performance. Any buyer can calculate this parameter, even without special knowledge. All you need to do for this is to multiply the volume of the room by the air exchange rate. The last parameter refers to the number of air changes per 1 hour of operation. In this case, the multiplicity depends on the type of room for which the exhaust device is purchased. So, for a bathroom used by up to 3 people, it will be equal to 6, if there are more than 3 users - 8 and up to 10 for a toilet.

When choosing a silent fan model for an extractor hood, it is advisable to buy a device that has inflated performance. So, for a bathroom, a device with an indicator of 95-100 m3/h is best suited.

The level of noise created during operation of the device. The operation of a fan is inevitably accompanied by noise - mechanical and aerodynamic. Under the first there is noise that arises as a result of the operation of the engine, or, more precisely, vibration transmitted to the air duct. Aerodynamic is the noise that arises from the movement of air currents. To prevent a duct fan from creating inconvenience for you, choose models with noise levels of no more than 25 dB. Models with a threshold of more than 35 dB will not allow you to stay indoors for a long time without feeling discomfort. Therefore, it is not recommended to purchase devices with similar characteristics for residential premises.

There is a solution to reduce the noise level of a duct fan. This can be done by installing a muffler behind the housing, as well as by additionally finishing the ventilation shaft with a material that has enhanced sound insulation characteristics.

Design safety. This parameter indicates the level of protection of the device from moisture and dust. It is necessary to take this into account if you are looking for a duct fan model that you are going to install in a rectangular shaft in the bathroom or kitchen, where high humidity is constantly present. If moisture gets inside the housing, a short circuit may occur. Therefore, it makes sense to immediately buy fans equipped with moisture protection for such rooms. As an alternative, you can purchase devices that can operate in low voltage 24V conditions.

Hood functionality. Today in stores you can find 100 mm models that can operate in two modes - automatic or standard. Standard axial supply fans start working the moment the lights in the room are turned on. This is an excellent solution for rooms where the humidity level is normal. If the humidity in the room is constantly increased, then it will be difficult for such devices to remove air. In this case, it is best to purchase a model with a timer that will automatically turn the device on and off.

Also, some fan models can be equipped with a special humidity sensor, which is very convenient for the bathroom. Of course, such hood devices will cost more than standard ones. But thanks to the use of such additions in them, they will be able to remove excess moisture from the room much better and faster.

Quality of the device. If you want a bathroom or toilet fan to serve you for many years without requiring attention to operation and repair, then choose models that meet international standards. For example, make sure that the duct fan has a protection class of at least IP 34.

Don't skimp on buying a fan for your home. Try to purchase models that are produced by well-known companies and are very popular among consumers.

Electric motors used

The industrial snail hood is equipped with explosion-proof electric motors, durable housings and covers. Most often, asynchronous mechanisms with a fixed rotation speed are used as a drive. This unit quickly reaches maximum performance and is reliable and durable. The disadvantages of asynchronous electric motors include the inability to adjust the speed of rotation of the working shaft, which somewhat limits the possibilities of using such equipment.

The presence of dimming in the electric motor and an automatic control unit allows you to regulate the rotation speed, significantly expanding the functionality of the use of volute fans. The disadvantage of using such motors with variable speed control is their high cost, as well as reduced reliability of units in which the electronics that control the operation of the drive often fail.

Sources

• https://StanokGid.ru/osnastka/ventilyator-ulitka-svoimi-rukami.html
• https://vozduhstroy.ru/vytyazhka/ventilyator-ulitka-svoimi-rukami.html
• https://www.RoomKlimat.ru/section/5/64-tsentrobezhnye-ventilyatory/
• https://TopVentilyaciya.ru/ventilyaciya/vytyazhka-ulitka.html
• https://AeroClima.ru/dymoudalenie/ventilyator-ulitka/
• https://ru-remont.com/kvartira/kuhnya/tehnika/krupnaya/vytyazhka/vidy/ulitka.html
• https://spk-kovka.ru/stanki/ventilyacionnye-ulitki.html

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Advantages and disadvantages

The ventilation volute combines reliable design and excellent efficiency. The advantages of this type of equipment include:

• affordable price;
• ease of operation, maintenance and repair;
• reliability and wear resistance;
• performance.

Disadvantages include difficulties in adjusting power and rotation speed. Such operating features are typical for fans equipped with an asynchronous motor. If it is necessary to change the rotation speed, it is necessary to purchase units with advanced automatic control, which leads to an increase in the cost of the equipment.