Types of ventilation are represented by a wide variety of systems of various types and purposes. Systems are divided into several types based on common characteristics. The main ones are the methods of air circulation in the building, the service area of the unit, and the design features of the product.
Natural way of air exchange
When considering the types of ventilation devices, you should start with this type. In this case, air movement occurs for three reasons. The first factor is aeration, that is, the temperature difference between indoor and outdoor air. In the second case, air exchange occurs as a result of wind pressure. And in the third case, the pressure difference between the room used and the exhaust device also leads to air exchange.
The aeration method is used in places with high heat generation, but only when the incoming air contains no more than 30% of harmful impurities and gases.
This method is not used in cases where the incoming air needs to be treated or the influx of outside air leads to condensation.
IN ventilation systems ah, where the basis for air movement is the pressure difference between the room and the exhaust device, the minimum height difference should be at least 3 m.
In this case, the length of horizontal sections should not exceed 3 m, while the air speed is 1 m/s.
These systems do not require expensive equipment; in this case, hoods located in bathrooms and kitchens are used. The ventilation system is durable and does not require purchasing additional devices. Natural ventilation is easy and cheap to operate, but only if it is set up correctly.
However, such a system is vulnerable, since it is necessary to create additional conditions for the flow of air. For this purpose, pruning interior doors so that they do not interfere with air circulation. In addition, there is a dependence on the air flow that blows through the building. It depends on him natural system ventilation.
An example of this type is an open window. But with this action or installation of hoods, another problem arises - a large amount of noise coming from the street. Therefore, despite its simplicity and efficiency, the system is vulnerable to a number of factors.
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Means for artificial air exchange
An artificial system, also known as a mechanical one, uses additional devices for ventilation that help air enter and leave the building, thereby organizing a constant exchange. For this purpose, a variety of devices are used: fans, electric motors, air heaters.
The big disadvantage of operating such systems is energy costs, which can reach rather large values. But this type has more advantages; they fully cover the costs of using the funds.
The positive aspects include the movement of air masses to the required distance. In addition, such ventilation systems can be adjusted, so that air can be supplied or removed from rooms in the required quantity.
Artificial air exchange does not depend on environmental factors, as is observed with natural ventilation. The system is autonomous, and during operation additional functions can be used, for example, heating or humidifying the incoming air. At natural type this is impossible.
However, it is currently popular to use both air supply systems at once. This allows you to create necessary conditions indoors, reduce costs, increase the efficiency of ventilation in general.
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Supply air supply method
This type of ventilation system is used to provide a constant supply of fresh air. The system can prepare air masses before they enter the apartment. For this purpose, air purification, heating or cooling is carried out. Thus, the air acquires necessary qualities, after which it enters the room.
The system includes air supply units and air vents, and the installation that provides air supply, in turn, includes a filter, air heaters, a fan, automatic systems and sound insulation.
When choosing such devices, you should pay attention to a number of factors. Great value has the volume of air entering the building. This figure may be several tens or several tens of thousands cubic meters air entering the room.
Indicators such as heater power, air pressure and noise level of the device play a big role. In addition, these types of ventilation devices have automatic control, which allows you to regulate power consumption and set the level of air consumption. Devices with timers allow you to set the unit to operate on a schedule.
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Combination of two methods: supply and exhaust type
This system is a combination of two ventilation methods - supply and exhaust, which allows you to use positive qualities both systems simultaneously and leads to improved air exchange.
As in the previous version, there is a means of filtering and regulating incoming air masses. This type can create the necessary conditions in the room, regulate the level of humidity of the incoming masses, create the desired temperature by heating or cooling the air. Filtering air masses coming from outside is also part of the functionality of the unit.
Supply- exhaust system will help reduce costs, which is achieved by removing heat, which is used to heat the incoming air. This process takes place in a recuperator - a special-purpose heat exchanger.
Exhaust air masses having room temperature, enter the device, after which they transfer their temperature to the recuperator, which heats the air coming from outside.
In addition to the above-mentioned advantages, supply and exhaust ventilation has another quality that is well suited for people suffering from changes in blood pressure. We are talking about the ability to create increased and decreased pressure compared to the environment.
The device is autonomous, independent of conditions environment, thanks to which it can be used all year round. However, the system is not without negative qualities. Among them is the need for precise adjustment. If both methods - exhaust and supply - are not balanced with each other, then a person using this type of ventilation runs the risk of getting drafts in the house.
Ventilation system is a set of devices that provide air exchange in a room, i.e., removing polluted, heated, humid air from a room and supplying fresh, clean air into the room to normalize its temperature, humidity and cleanliness.
Ventilation happens:
– natural and mechanical (according to the method of air movement);
– local and general exchange (according to the form of air exchange organization).
Mechanical is called ventilation, in which air is supplied to rooms and removed from them through systems of ventilation ducts using special mechanical stimuli - fans.
Mechanical ventilation can be:
Supply air, in which air is supplied to the room by a fan;
Exhaust, in which air is removed from the room;
Supply and exhaust, in which fresh air is supplied to the room, and polluted air is removed from the room.
Local ventilation is characterized by the fact that with its help contaminated air is removed directly from the emission zone harmful substances.
With natural ventilation air exchange occurs due to heat and wind pressure, due to the resulting pressure difference outside and inside the building. The effect of these factors is stronger, the greater the temperature difference in the upper and lower zones of the room and the greater the height of the room. As a result, the warmer air in the room rises up and is removed from the room through exhaust pipes, and its place is taken by fresh, cooler and cleaner air entering the room through windows, doors, vents, transoms, and cracks.
Natural ventilation of rooms can be unorganized and organized. In conditions of unorganized ventilation (ventilation), air enters and leaves through windows, vents, special openings, as well as through leaks in external fences (infiltration). Organized (regulated) natural ventilation of industrial premises is called aeration. It is carried out using specially created structural elements industrial buildings - aeration lamps or using special channels or shafts operating under the influence of thermal pressure. In order to increase the efficiency of wind pressure, these shafts are equipped with special nozzles - deflectors.
Mechanical ventilation, unlike natural, allows for pre-treatment supply air– humidification, heating or cooling and cleaning from dust, gases and other impurities. To local settings mechanical ventilation include local suctions open type, including protective and dust-free housings, fume hoods, side suction, articulated-telescopic suction (built into workplaces, tools), movable suction, as well as exhaust hoods, shelter boxes, chambers and cabins.
General ventilation used in cases where harmful substances, excess (mainly convection) heat and moisture are released dispersed throughout the work area, and it is technically not possible to remove them using local suction, as well as in cases where it is necessary to dilute them to the maximum permissible concentration in the remainder air not removed by local suction. Operating principle of general ventilation is based on diluting polluted, overheated or overhumidified air to levels that meet hygienic requirements. This type of ventilation is neither effective nor economical.
At supply ventilation The supply air must be processed: heated or cooled, removed from dust, and in some cases humidified. Air recirculation in supply and exhaust ventilation systems it is used in the cold and transitional seasons in order to save heat spent on heating the air. During recirculation, part of the air removed from the room after appropriate cleaning of harmful substances is sent back into the room.
Air conditioning– creation and automatic regulation of specified microclimate parameters in premises (temperature, humidity, air mobility) and other sanitary and hygienic parameters. Air conditioning systems must supply dust-free air. Sometimes there are requirements for cleaning the air from bacteria, for its ionization, deodorization or aromatization.
In rooms with a volume of more than 40 m³ for each worker, if there are windows and there is no release of harmful or unpleasantly smelling substances, it is allowed to periodically ventilate. In rooms without natural ventilation, the air supply per person should be at least 60 m³/h.
Comfort in our lives is largely ensured thanks to ventilation systems. Clean air and an optimal microclimate have become components of everyday life. As you know, a person inhales oxygen and exhales carbon dioxide, which is life-threatening. Particularly important is the issue of updating the atmosphere at work sites and warehouses, and the availability of ventilation in residential buildings.
What is a ventilation system in an apartment, private house, or industrial premises?
Ventilation system- complex equipment for regulating indoor air exchange. The system also affects the microclimate due to technical means. Modern ventilation capable of purifying the air flow, humidifying it, heating or cooling it. Providing air circulation in an apartment, private house and production workshops varies significantly.
As mentioned above, a person emits carbon dioxide - an integral part of life. The air that a person inhales must be saturated with at least 20% oxygen. Lower readings result in headaches in best case scenario, and the constant lack of oxygen significantly affects well-being.
Air in living rooms must be updated at least once per hour. In other words, the update rate per hour is 1. This is enough for comfortable living in an apartment or private house. But even so, in kitchen areas the multiplicity increases to 3-5 times.
Air circulation in a closed workshop or warehouse has a high multiplicity. In plants and factories, there are usually other sources of pollution, which means that cleaning must be done more often. For example, in public smoking rooms, which are an integral part of large production facilities, air circulation should occur at least ten times.
Thus, the load on ventilation systems in production is higher than in residential apartments. If in a private house it is possible to update the microclimate simply by opening a window, then in production workshops such an opportunity is practically absent.
Methods for determining the broad classification of ventilation systems
Ventilation can be characterized by 4 types: according to the method of air circulation, purpose, structural structure and working area. Each type has advantages and disadvantages.
Types of ventilation according to the method of forming air flows
Air exchange occurs due to natural draft, which depends on two factors:
- difference in temperatures outside and inside;
- difference in pressure between room and exhaust.
Weather conditions, such as wind, matter. Such systems do not require additional equipment, consume little electricity and are easy to operate.
Artificial, otherwise called mechanical, ventilation operates on the basis of equipment and a set of additional devices, due to which the air exchange covers large premises. Mechanical systems require enormous amounts of electricity to operate. They are completely autonomous and are not influenced by nature.
What types of ventilation are there by purpose?
There are supply and exhaust ventilation. The supply system carries out the influx of fresh air, the exhaust system - the outflow of treated air. The systems are used together. They can also be classified as local - for a specific area, and general exchange - for large workshops.
Types of ventilation systems by area of operation
Types of local ventilation- supply and exhaust systems. When using this type, air is supplied to a selected area, and only the place where carbon dioxide accumulates (the ceiling) is purified. An example of local supply ventilation can be: air curtains commonly used in public places.
Local exhaust specializes in places where pollution accumulates. This practice helps prevent them from spreading throughout the entire room, greatly facilitating the work of the ventilation system.
Interesting! Local ventilation practically does not require costs, unlike general exchange. But in production workshops, both types are used, since only local ones are not able to simultaneously provide both functions over large areas. General exchange systems uniformly remove polluted air and supply clean air.
What is the type of ventilation in rooms according to design?
There are two types of ventilation design. The monoblock is a single box with sound insulation, being a popular design for installation in homes. There are supply and supply and exhaust types. They do not produce noise, are small in size and easy to install.
A kit is an assembly of various components and additional parts. The advantage is the ability to ventilate both small apartments and entire buildings. The downside can be considered large sizes and high requirements for the placement of the entire system.
Types of ventilation systems
All types are characterized by a number of parameters, the most important of which is air pumping, which is also the performance of the entire system. Pressure (pressure), power and noise level are also important.
How does one type of ventilation differ from others (a brief comparison of all types)
The local type of ventilation, unlike general ventilation, supplies air to one place and takes polluted air from there. General exchange - affects the entire room. The supply type is designed only for air supply, while the exhaust type directly affects purification.
Types of air vents for different ventilation systems
Ventilation systems include equipment united by air outlet channels - an indispensable part of ventilation systems. The outlets perform the main function: exchange of air masses. Only three factors influence the efficiency of their work: type, material of manufacture and cross-sectional shape.
Important! You should pay attention to the above characteristics, however important will have parameters: dimensions, sealant and noise insulation.
Air vents are classified by type of material: plastic (general use) and metal (for factories). And the section shape: rectangle and circle. In addition, there is an additional criterion of rigidity and flexibility. Flexible air vents are used when branching channels.
VENTILATION IS CALLED BOTH THE PROCESS OF REMOVING EXHAUST AIR AND REPLACING IT WITH FRESH AIR AND THE EQUIPMENT FOR THIS PROCESS. WITHOUT FRESH AIR ANY HOME, EVEN THE COZIEST HOUSE, IS UNSUITABLE FOR LIVING, AT LEAST FOR ANYONE WHO NEEDS OXYGEN.
What is ventilation
Ventilation is the movement of air in a room. Air enters any building from the street. Getting inside the room, the air is filled with various substances: carbon dioxide from our breath, dust, chemical emissions from objects, animal hair, etc. This already polluted air moves to the hood and is discharged out through it. At this time, a new portion of fresh air from outside enters the room, which also goes into the hood. This whole process is called ventilation.
Climate control equipment that ensures the correct functioning of the described process is also called ventilation. It can be natural and mechanical, channel and compact, supply and exhaust, and much more. All types of ventilation and their features are described below. In the meantime, let's figure out how important ventilation is in an apartment or house.
Why is ventilation needed?
It is thanks to ventilation that a healthy and comfortable microclimate is created in the room, namely:
1. Carbon dioxide levels are normalized
Carbon dioxide is always present indoors: after all, we exhale it! The only question is how much it is. When carbon dioxide accumulates excessively, it has negative impact on the human body. It interferes with the full supply of oxygen to the blood and organs. The brain begins to become “lazy,” and we feel tired, lethargic, and become inattentive. A high concentration of carbon dioxide is also associated with a feeling of stuffiness.
Good ventilation ensures constant air renewal. The air coming from the street replaces the air in the room along with the carbon dioxide accumulated in it. It is not stuffy and comfortable to be in such a room.
2. Humidity is normalized
Proper ventilation assumes that excessively humid air from the premises is promptly released into the exhaust hood. This eliminates the formation of eternally damp areas in corners and on walls where mold actively grows.
The ventilation system may also have additional functions. For example, air filtration allows you to remove contaminants from the air at the entrance to the room and make the air healthy and safe. And the heating function in the ventilation prevents the risk of catching a cold from cold air from the street.
If the ventilation system is bad
If there are disturbances in the air inflow or outflow, then:
Carbon dioxide will accumulate in the room
Consequences: feeling of stuffiness, increased fatigue, lethargy, loss of concentration. And also in stuffy room It's hard to get enough sleep.
Humidity balance may be disrupted
If the air stagnates, moisture can accumulate in it. Poor ventilation is a common cause of dampness and mold.
Pollution accumulates in the air
Dust, animal hair, mold spores, anthropotoxins, harmful chemical emissions from furniture (for example, formaldehyde) - all this “enriches” the air in conditions of poor ventilation and ultimately enters our body through the lungs.
THE OPERATION OF THE VENTILATION SYSTEM AFFECTS THE WELL-BEING OF A PERSON IN THE ROOM, HIS PERFORMANCE, CONCENTRATION AND QUALITY OF SLEEP.
Therefore, it is important to choose high-quality ventilation, which will cope with the needs for air exchange and provide a comfortable microclimate.
Types of ventilation
Types of ventilation systems by location
For big country house One ventilation system is suitable, and another for a small city apartment. Or, for example, duct ventilation, which is rational in an office environment, simply does not fit in a Khrushchev five-story building.
How to decide which type of ventilation is suitable for your home, office, apartment? It all depends on the area, configuration, location and purpose of the rooms or offices for which you are choosing a ventilation system. And, of course, your budget plays an important role. Buying a ventilation system means making a long-term investment in your own comfort and the comfort of your loved ones. So you should choose the type of ventilation carefully.
Types of ventilation systems by parameters
Classification of ventilation equipment according to various aspects
- By air circulation method: natural and forced (mechanical).
- By purpose: supply, exhaust or supply and exhaust.
- By design: ducted and ductless (ventilator, supply valve, breather).
- By additional functions: heated ventilation, ventilation with air filtration, etc.
Natural and forced ventilation
In most of our residential buildings ventilation is natural. This means that air enters the building from the street on its own, without any special equipment or artificial injection. It usually enters houses through leaks in walls and windows, as well as through doors. And it comes out through the hood: exhaust openings are usually located in the kitchen and bathroom. The air from the room is drawn through them into the ventilation shaft, rises up it and is thrown out through the roof.
It operates due to temperature differences and pressure differences inside and outside the room.
The main advantage of natural ventilation is its accessibility. The organization of such a ventilation system does not require large financial investments. But there are also disadvantages. Firstly, the natural ventilation system easily fails. Installed sealed plastic windows instead of grandfather's wooden ones - and now the air flow is insufficient, the house is stuffy and uncomfortable. Or the hood is clogged - and there is always musty air in the apartment. Secondly, in conditions of natural ventilation there is only one way to properly ventilate - open the window. But an open window, unfortunately, is not only fresh air. This is also noise, dust, pollen, cold and unpleasant odors.
To eliminate these shortcomings, natural ventilation must be replaced or supplemented with mechanical (forced) ventilation.
Forced ventilation
This is a system in which air stably and continuously enters the room, regardless of external weather conditions. Air is forced into the room using fans or other equipment built into the system. Forced ventilation allows you to regulate the inflow rate, adjusting its operation to the air exchange needs.
The operation of forced ventilation usually does not require human intervention or additional opening and closing of windows, which makes it most convenient for domestic use.
Duct and ductless ventilation
Such systems are laid and installed during construction or major repairs. They usually provide both air supply and exhaust at the same time.
How is duct ventilation arranged? Firstly, there is a central air treatment unit (cleaning and disinfection, heating, air conditioning, humidification). Secondly, there are air ducts running under the ceiling from the central unit. Of course, to accommodate such a ventilation system, a lot of free space is required. Therefore, duct systems are of little demand in city apartments of small and medium size and with ceilings less than 3 m.
Most often, duct ventilation is found in large buildings where there are many people at the same time (offices, shopping centers), as well as in rooms with high requirements to air purification or temperature (hospitals, warehouses, restaurant kitchens).
Ductless ventilation
Systems that are compact in size and can be placed in any apartment, house, and even in individual rooms.
Supply and exhaust ventilation
Supply ventilation
Supply ventilation ensures the flow of air from the street into the room.
It is installed on the wall inside the apartment and, using fans, supplies fresh air through a channel in the wall.
Natural inflow can be enhanced using a wall or window valve. The price of such ventilation is low, but it must be borne in mind that the operation of the supply valve depends on weather conditions. The warmer it is outside the window, the smaller the pressure difference between outside and inside the room. So in summer the efficiency of ventilation using the valve tends to zero.
A device with the functions of a ventilator and air purifier. It also supplies fresh air, filtering and heating it at the same time. The breather can be controlled from a smartphone.
VENTILATION IN THE WALL, UNLIKE DUCT SYSTEMS, IS INSTALLED AT ANY STAGE OF REPAIR, EVEN AFTER CLEAN FINISHING. INSTALLATION OF SUCH A VENTILATION SYSTEM IS DONE QUICKLY, IN JUST AN HOUR. THE ROOM STILL REMAINS CLEAN.
Exhaust ventilation
Through the hood, the so-called exhaust air is removed from the room - air filled with odors and indoor pollutants (dust, animal hair). If desired, natural exhaust can be enhanced by forced exhaust by installing a fan in the exhaust opening. The ventilation performance for the hood will depend on the area of your kitchen or bathroom where the fan is installed.
Supply and exhaust ventilation
Provides simultaneous inflow of fresh air and outflow of exhaust air.
Ventilation with additional functions
Ventilation with heating
If sub-zero temperatures outside the window are not uncommon, then supply ventilation with air heating is needed. Otherwise, cold air will blow into the room, and this can easily result in a cold.
It can have a climate control system and automatically heat the air to a user-selected temperature.
Ventilation with filtration
Air purity - important condition healthy image life.
Contains air filters for various purposes. These can be simple filters with a mesh structure, highly efficient filters with a complex interweaving of the finest fibers, or carbon filters that trap harmful gases and odors.
Buy a ventilation system
Get rid of stuffiness, establish proper air circulation in the rooms, breathe clean air- all these issues can be easily resolved by purchasing a ventilation system with the functions of air supply, cleaning and heating.
Breezer is one of the most popular devices on the supply ventilation market. It supplies air to 4-5 people, cleans the supply air from dust, dirt, car exhaust, and allergens. The climate-controlled heater eliminates drafts. And you can control it from your smartphone manually or by setting the automatic mode.
There are different models breathers. Functions, characteristics, design, price - Tion ventilation meets any requirement.
A ventilation system is a set of special equipment for the constant or periodic removal of exhaust air from industrial, warehouse and residential premises. Until the beginning of the 19th century, there were no mathematical calculations for ventilation; the indoor microclimate was maintained only through natural ventilation of the premises using exhaust ventilation. This approach could not guarantee adequate indicators and was associated with big losses thermal energy, significantly complicated the process of air exchange at night and winter period time.
A theoretical description of the movement of air in exhaust ventilation ducts was first made by M.V. Lomonosov, and V.H. Friebe created the theory of air exchange rates in heated rooms. At the same time, he took into account that the influx of fresh air and removal of exhaust air is done through leaks in the door and window openings, special engineering elements were not provided in those days.
Only a few decades later scientists proved that to ensure effective ventilation only due to natural it is impossible, types of ventilation systems with forced submission and removing air. Depending on the specific installation location, operating conditions and required technical parameters The general exchange system has several types.
Ventilation units perform the following tasks:
- Removing excess heat. Excess indoor heat appears in industrial and residential buildings. IN industrial buildings excess heat is most often a consequence of the peculiarities of the technological process, in which it becomes necessary to heat one or another raw material to obtain the final product. In residential premises, an increase in temperature above comfortable parameters occurs due to heating by the sun's rays. Special technical rooms can overheat as a result of the release of thermal energy by powerful power units, they also need air exchange.
- Removal excess moisture. For residential premises, such a need arises only in bathrooms and kitchens. The rest of the living quarters suffer not from excess moisture, but from its lack. As for industrial facilities, the need to adjust air environment relative humidity indicators depend on the characteristics technological processes, air exchange takes into account all data for each stage of production.
- Removal of harmful chemical compounds. The purpose of ventilation devices is to remove toxic chemical compounds from work areas or the entire volume of the room. Ventilation is installed in chemical production workshops, laboratories, industrial companies using paint and varnish materials. In addition to these premises, harmful chemical compounds must be removed from residential premises if they were used chemicals cleaning, there are many products made from artificial materials. Harmful chemical compounds are formed during cooking in kitchens; the air exchange rate in these rooms cannot be lower than 10.
- Increased oxygen levels. According to the requirements of SanPiN standards, the percentage of oxygen cannot fall below the established values. This indicator is monitored especially carefully in sleeping areas. Depending on the oxygen consumption for each volume, the minimum air exchange rate of the exhaust system is calculated.
- Removing dust. Dust accumulates in both residential and industrial premises. In living rooms, dust causes unpleasant allergic reactions in the body. In industrial buildings, dust causes acute or chronic diseases respiratory system. Ventilation equipment for dust removal must have special filters.
- Reductions fire danger, removal of flammable and explosive substances. Ventilation units for these purposes they have the highest technical requirements. They are equipped with special equipment, work in conjunction with sensors for monitoring air quality indicators, etc. Strict requirements are imposed on the spark extinguishing of the operating electrical equipment and units.
Installed ventilation systems can perform either only one of the assigned tasks or work in a complex manner. Depending on engineering features, technological schemes and principles of operation, ventilation systems come in several types.
Currently, there are several types of ventilation, differing in installation method, installed equipment, operating principle and technical capabilities. Ventilation systems are distinguished by several technical parameters: the method of air flow circulation, service area and design features.
Methods of room ventilation
Air flows may have natural physical causes of movement indoors, mechanical stimuli or mixed type. Specific types of ventilation are determined after engineering calculations made taking into account the technical specifications. The technical specifications for air exchange indicate maximum quantity individual factors and requirements.
Natural ventilation With natural ventilation, air can move due to differences in the density of air flows. Indoor air, as a rule, has higher temperatures than outside. Warm air with less specific gravity rises up and through special channels or natural leaks is removed to the outside, replaced by more dense cold water. This type of ventilation has its positive and negative sides.
- Positive aspects of natural ventilation. There is no need to use additional energy carriers for the system to operate – when modern prices a very significant advantage.
- Disadvantages of natural ventilation. It is very difficult to regulate the frequency of air exchange. Problems arise because many important data depend only on natural conditions and are not regulated by the human factor, air exchange is not accurately predicted. Another problem is the possibility of reverse thrust. This is very dangerous when ventilation is installed to service heating boilers.
Due to these operating features, natural ventilation is currently not very popular; preference is given to mechanical exhaust. For new construction of various buildings state standards require installation of mechanically driven ventilation.
Mechanical ventilation The movement of air flows is provided by axial or centrifugal fans, the air moves through channels. The technical parameters of the channels and fan are selected taking into account the requirements for the systems.
- Advantages of mechanical ventilation. It is possible to regulate air flows both in power and direction. Mechanical air exchange allows you to create separate zones in one room with different rates of exchange, eliminating the appearance of dead zones and drafts. And one more very important advantage – mechanical system can function completely autonomously.
- Disadvantages of mechanical ventilation. The mechanical system has two disadvantages: complexity of installation and maintenance and energy consumption. Maintenance of the mechanical system requires professional specialists and requires periodic inspections and inspections. Installed fans may have greater power, which negatively affects the cost of production and maintenance of industrial and residential buildings.
Mechanical System Features Air flow is ensured mechanically, which allows you to create systems with precisely specified parameters. Depending on the method of air supply and removal mechanical types ventilation can have several varieties.
An electric fan forces air into the room, thereby increasing its pressure; to equalize the pressure values, the excess goes outside in a natural way. The fan is mounted directly inside the ventilated room, in special technological rooms or outside. The final decision on the mechanical system is made after calculations have been performed, taking into account the technical parameters of the equipment and the location of the building. The supply system for residential premises is not used.
The fan is installed to forcefully remove contaminated air, while fresh air is supplied through special ventilation ducts or through loosely closed window and door openings. Exhaust ventilation most often mounted above individual work areas, in closed cabinets laboratories, food and pharmaceutical industries. In some cases, an exhaust system is the only way to ensure safe conditions labor.
Air is supplied and removed from the premises forcibly. One fan pumps air, and the second fan removes air from the premises. Air exchange is characterized by high intensity and can be adjusted for each parameter separately. Mechanical system supply and exhaust system This type is used for ventilation of heavily polluted rooms; it is rarely installed in residential buildings.
Local ventilation Local ventilation allows you to remove pollution only from the most contaminated areas; it may have special filters to prevent environmental pollution. According to the principle of operation, it is most often of the supply type. Local ventilation can serve one or more workplaces, work on each zone separately, or ventilate all at the same time. The power of the mechanical system is relatively small, but the specific parameters depend on the characteristics of the technological processes and the features of the building layout.
Local supply ventilation The local supply system is rarely used due to the great difficulties in cleaning the exhaust air. Most often it is used only to lower the temperature of operating equipment; it is ineffective for cleaning the air from harmful substances. The supply air supply is used in large sales areas and warehouses. It is often installed in office and government buildings, where the local supply system is constantly functioning.
Local exhaust system Purpose – removal of harmful compounds from the air in a small volume. It can have several options for air suction: from enclosed spaces or with special suspended air receivers. The latter are often installed above cooking stoves, electrolytic baths and other equipment with small linear dimensions.
Special types of ventilation systems There are several types of special purpose ventilation systems:
- Emergency ventilation system. Installed in rooms where a sharp increase in the amount of harmful emissions is possible. It is used in case of breakdowns of the main general exchange system; it can have its own fans or be connected to already installed electrical equipment.
- Anti-smoke. Used in combination fire prevention measures, increases the safety of people staying indoors. In most cases of autonomous operation, it has special monitoring and control units.
According to the type of air ducts, general-exchange ventilation systems can be ducted or ductless.
Ventilation system calculation parameters Calculation of the ventilation system - complex engineering work performed only by specialists with special technical education. During the execution of work, the following initial data are taken into account:
- Air exchange rate. Depending on the purpose of the premises and the characteristics of technological processes, sanitary inspection authorities regulate the minimum frequency of air exchange. Indicators vary widely; the minimum exchange rate has a decisive influence on all other technical data of the ventilation system.
- Noise level indicators. The data is determined at maximum load on the general ventilation fans or at maximum speed air flow movements. The noise level depends not only on the type and power of the fans, but also on the materials used to make the ducts, the methods of installing air ducts and the presence of special devices for noise reduction. In some cases supply fans may only be installed outside the building.
- Power electric motors fans. An indicator that influences the cost of operating a ventilation system. To increase the efficiency of electric motors, a set of complex technical measures is used to reduce losses due to friction of air flows through the channels, accurate calculation nominal diameters, optimal layout and flow movement.
- Economic indicators of use. To reduce heat losses, heat recovery is currently widely used. When designing room ventilation, it is necessary to install special equipment designed to extract heat from the removed air and heat the supplied air. Recuperation can work both for heating and cooling rooms, and allows replacing expensive air conditioning systems.
Algorithm for calculation and installation of room ventilation
When calculating the ventilation system, the initial data (technical specifications) of the customer are taken into account. The customer must indicate the required air circulation in accordance with the existing operating conditions of the premises. Further calculations are performed according to the following scheme:
- Calculates the required air exchange rate in rooms and work areas. The minimum supply air ratio is specified in SanPiN; designers are guided by regulatory requirements.
- The calculation of air flow speed, size and layout of channels, installation location, technical data and number of fans is carried out.
- Compiled circuit diagram general ventilation of premises. For complex systems a breakdown is made into sections and branches, and all the initial data for installation is indicated on the drawings.
At the preliminary development stage project documentation agreed with the customer, changes are made if necessary.
Installation of ventilation systems can only be carried out by specialized companies licensed to perform this type of work. Regardless of the type and purpose, general ventilation consists of the following units and elements:
- Fans. They can be centrifugal and axial, built-in and free-standing. Power, size and performance vary widely.
- Air channels. Made from various materials, can be round, square or rectangular. The inlet cross-sectional area is selected based on calculated data on the speed of air flow.
- Automatic or manual control devices. Used to maintain the required operating parameters, industrial general ventilation is most often controlled automatically.
- Filters. Installed on ventilation systems of residential and industrial premises. Depending on the design, they can capture suspended solid microparticles or chemical compounds.
- Silencers. Special equipment that allows you to significantly reduce vibrations of operating mechanisms. Have various designs, are mounted both on the main channels and on branches.
After installation, it is mandatory to check the functionality of the ventilation; the air exchange is measured both in the room as a whole and above each work area. Acceptance certificates are signed by members state commission in the presence of the customer and the contractor. Records of periodic inspection, repair and maintenance of industrial ventilation systems are made in a special journal and signed by the responsible persons.
