The presence of a ventilation system is necessary to ensure air exchange inside the building by removing excess moisture, heat and harmful substances. Her presence is one of the main conditions for life support.
If there are no any types of ventilation systems in the room, it damages the human body, leads to the formation of fungi, because in the absence of air exchange condensation forms.
We offer to understand the existing types of systems for ventilation and the principles of their work.
The content of the article:
Classification of ventilation systems
- Types of ventilation system according to the method of supply
- Types of ventilation to destination
- Ventilation systems by way of air exchange
- Separation of systems by design
- Natural room ventilation
- Mechanical ventilation characteristics
General mechanized ventilation
- Mechanical local ventilation
- General Exhaust Ventilation
- Mechanical forced-air ventilation
- Mechanical ventilation in case of accident
- Ventilation against smoke
- Conclusions and useful video on the topic
Classification of ventilation systems
Systems are classified according to different criteria:
- filing method;
- air exchange method;
The type of ventilation is determined at the design stage of the building. At the same time, they take into account both the economic and technical aspects as well as sanitary and hygienic conditions.
Types of ventilation system according to the method of supply
Based on the methods of supplying and removing air from a room, there are 3 categories of ventilation:
Perform ventilation designif such a solution is able to provide air exchange ‚corresponding to the established norms.
When natural ventilation does not meet the requirements of sanitary and hygienic standards, choose the second option - a mechanical method of air mass activation.
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Ventilation systems are designed to supply fresh air and exhaust exhaust air from the room. If a natural system fails to deliver, it is supplemented by mechanical or mechanical ventilation.
Ventilation systems allow not only to form a favorable microclimate for the residents, but also to take out of the closed heated rooms are harmful to building materials and finishing evaporation, which significantly extends the operating time of objects
In production shops of food, chemical, processing industry and many other national economy certified ventilation systems are installed in a mandatory okay
In high-rise buildings with water heating is dominated by natural systems, with steam - mechanical or combined, for which common boxes are most often arranged with filtering devices and heating
You should consider an effective ventilation system in country houses with stove and fireplace heating. It should be noted that in rooms with a stove or fireplace, as well as in a boiler room with gas equipment, ventilation can only be natural.
In residential high-rise buildings of the old type, designed for a free flow of air through leaks in window and door openings, exhaust openings are located in bathrooms, toilets, and mixed sanitary facilities. If there is a need to stimulate the movement of air flow in the hood put the fan, after which the system becomes mixed: with a natural inflow and a mechanized outlet
Actively operated kitchens of private houses and high-rise buildings are equipped with exhaust systems, due to which ventilation, by analogy with a bathroom, becomes combined. Moreover, the combined type includes both exhaust hoods with access to the ventilation shaft and recirculation types that simply drive the flow through the filter and return it to the room.
If window and door constructions prevent natural air exchange, as is the case with PVC windows, install an intake valve for the supply of fresh air. Among them are devices with and without a fan.
Device ventilation system
Air supply for airing building materials
Industrial type of ventilation system
Mechanical ventilation paired with air heating
Country house with a fireplace room
Ventilation in bathrooms and bathrooms
Exhaust equipment in the interior of the kitchen
Supply valve under the window sill
If possible, in addition to the second ventilation option, partially use the first one, in the project, mixed ventilation is laid. In homes, air flows through the windows, and exhaust equipment is placed in the kitchen and in the sanitary room. Therefore, it is important to establish good air exchange between rooms.
Mixed ventilation. Apply it when natural ventilation can not be the only option. For high-quality air exchange in rooms with very polluted air arrange mechanical ventilation.
Types of ventilation to destination
Based on the purpose of ventilation, allocate working ventilation systems and emergency. Whereas the former must constantly provide comfortable conditions, the latter only enter into operation when disabling the first and the occurrence of an emergency when the standard conditions are violated life activity.
These are sudden failures when air pollution occurs with toxic fumes, gases, explosive, toxic substances.
Types of ventilation systems for all types of rooms are almost the same. After examining all their types and weighing all the advantages and disadvantages ‚you can choose the best option for a particular building
Emergency ventilation is not designed for fresh air. It only provides a gas outlet and does not allow the air mass with hazardous substances to spread throughout the room.
Ventilation systems by way of air exchange
According to this criterion, general-exchange and local ventilation systems are distinguished. The first one should provide the entire volume of the room with sufficient air exchange with the maintenance of all necessary air parameters. In addition, it must remove excess moisture, heat, pollution. Air exchange can be carried out both on channel, and beskanalny system.
General trade inlet ventilation reduces the concentration of harmful substances remaining after operation of the local and general exchange exhaust ventilation system
The purpose of local ventilation is to supply clean air to specific places and remove contaminated material from the points where it forms. As a rule, it is arranged in large rooms with a limited number of employees. Air exchange occurs only in the workplace.
Separation of systems by design
Based on this feature, ventilation systems are divided into ductless and ductless. Channel-type systems consist of an extensive route consisting of air ducts along which air is transported. The installation of such a system is advisable in large premises.
When channels are missing, the system is called channelless. An example of such a system is an ordinary fan. There are 2 types of ductless systems - ceiling and laid under the floor. Channelless systems are simpler to implement and consume less power.
Natural room ventilation
The movement of air masses during natural ventilation occurs naturally without additional inducement due to:
- temperature difference inside and outside the building;
- the pressure difference between the room and the hood, located on the roof of the building;
- under the influence of the wind.
This is the simplest system. There is no need to install complex expensive equipment that consumes a lot of electricity. Such a system cannot be called reliable due to the fact that its effectiveness depends on factors uncontrollable by man.
The system can be organized and unorganized. Adjustable or organized system functions due to aeration or presence deflectors. Aeration is a general exchange process during which air enters and leaves through open air vents, lights, transoms.
Infiltration or unregulated ventilation natural ventilation is the ingress of air into the room through leaks in structures.
Despite the development of technology, natural ventilation is also used in modern facilities because of the simplicity and lack of operating costs. In addition to its dependence on environmental conditions, it is impossible to ignore the fact that there is a possibility of the occurrence of a phenomenon for which the term “tipping over” is used. This is a very precise definition - the air mass suddenly changes direction and starts moving backwards.
In industry, aeration is used in the presence of processes, where the technology of work is accompanied by the release of heat in large quantities. Its use is permissible provided that the supply air contains less than 30% of harmful emissions from the permissible concentration directly in the zone of their formation.
Do not apply aeration if the air entering the room requires pre-treatment, or as a result of the air flow outside condensation or mist may appear. By aeration, repeated air exchange takes place at meager energy consumption. This is its main advantage.
The principle of operation of the ventilation system with the natural movement of air flow is based on the difference in their temperature and pressure:
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The location of the components of the natural ventilation system is taken into account and thought out at the design stage of the house. In contrast to the components of the mechanical system to make them on completion of construction is problematic
Exhaust vents of natural ventilation systems are located at the highest point possible. The fresh stream coming from the street is exactly upwards that forces out the exhausted air mass.
The air inlets are located in the lower part of the room, outside they are located mainly on the basement of the house. Because of the air released into the exhaust air inside the room, a vacuum is created, which is rapidly filled with a fresh portion from the street.
In order to move the air to the exhaust hole within the apartment or house, the door leaf is equipped with a ventilation grille. If the grid is not installed, the door leaf should be 1-1.5 cm above the floor level
Natural type ventilation is ductless and ductless. Most often, the feed channels, less often - exhaust as in the photo
If the air flow does not move, there is no inflow, or the hood does not work, condensate can be seen on the windows. During normal system operation, it evaporates.
Interfered with the movement of air in systems of a natural type can clogged exhaust duct or lack of flow. It also happens in hot weather, when the apartment is cooler than on the street
To check the operation of natural ventilation in the simplest way, a sheet of paper is applied to the exhaust grille. If it is not pressed against the lattice, then it is necessary to take measures to restore ventilation
The construction of the ventilation shaft
The location of the exhaust hole
Supply device in the basement of the house
Interior ventilation grille
Channel natural ventilation system
Signs of Inefficient Ventilation
Return air flow
Checking the thrust of natural ventilation
In some cases, deflectors are mounted on the mouths of exhaust channels - special nozzles. They function through the use of wind energy. Deflectors do well with the task of removing dirty and excessively heated air masses from small rooms. Apply them to the local exhaust.
The normal operation of the ventilation, driven by a pressure difference, ensures a minimal difference between the intake point and the exhaust outlet of 3 m.
For the effective functioning of ventilation, experts recommend when laying air ducts not make horizontal sections longer than 3 m. The air in them should move with a speed of no more than 1 m / s
Mechanical ventilation characteristics
The ventilation system ‚with which air is supplied and removed using additional boosters for impressive distances‚ is called mechanical. There are other names for this type of ventilation - forced and artificial.
Apply it both to ensure technological processes in various industries, and to create comfortable conditions for humans.
Easy to install and use, the device provides exhaust air from the bathroom rooms, kitchens and bathrooms of private houses, is a ventilation system with automatic microprocessor:
A photo of
Channels for a compact exhaust system are constructed when performing draft work. They are displayed in the ventilation chamber or in the cold attic, false-ceiling is closed from the inside
After the device is false ceiling ceiling fan is connected to the ventilation duct
Smart fan stuffing is covered with an external protective and decorative lining that does not interfere with the device to react to changes in the air condition
Under the outer cover of the fan is a control panel that allows you to easily choose the best mode for users.
Channeling device for home system
Fan with integrated processor
Smart fan outer panel
Fan control panel
Mechanical ventilation, unlike natural, does not depend on external conditions. It is completely controlled and controlled. The air supplied to the room is processed and, with a streamlined system, all its parameters meet the standards. Emissions also enter the atmosphere already cleansed of harmful inclusions to the desired degree.
The mechanical system includes instruments and equipment - automatic fans, dust collectors, air heaters, electric motors. It all consumes a lot of electricity
The presence of a mechanical ventilation system allows you to optimally distribute the air supplying it to a specific place. With its help, harmful emissions are caught at the source of their formation without allowing to pollute the air of the entire room.
The lack of mechanical ventilation - large financial investments during its installation and operation. In order to enjoy all its benefits, it is necessary to fight the pollution of the canals, regularly replace the filters.
If a ventilation filter with heat recovery function is installed, it is necessary to switch to a summer liner before the onset of the summer period. If you leave the winter version, it will reduce the efficiency of ventilation.
Mechanical ventilation is both local and general exchange. The latter is implemented in 2 versions - channelless and channel. Air replacement in channel system occurs with the help of fans - centrifugal or axial ejector units.
In production, exhaust installations are more often used by ejector installations ‚especially where газ explosive gases are present. The use of ordinary fans is unacceptable here ‚because They may spark in the event of a malfunction. Their installation is practiced when installing the supply or exhaust system
General mechanized ventilation
Mechanically driven structures can be either inflow or exhaust. Ventilation is sometimes performed in conjunction with central heating.
The air receiver in such a system can have the form of holes in the enclosing structures of a building, either a stand-alone or an attached shaft. When mounted outside the building, the air inlet shaft is located above ground level or on the roof.
The layout of the air intake devices: in the enclosing structure (a) ‚near the outer wall (b)‚ on the roof (c). Hood ducts and shafts are warmed outside ‚otherwise in winter frost will appear in them
The choice of the structure and location of the air intakes is influenced by the requirements for the degree of cleanliness of the outdoor air, as well as the architectural features of the building. The bottom of the opening, through which fresh air enters, must be located at a distance of at least 2 m from the ground, but in the case of building dislocation in the green zone is 1 m. External air intakes cannot be placed where there are harmful emissions.
Air masses enter the mine through fan. Passing through the heater ‚they heat up‚ are humidified or, on the contrary, dried and flow inward through ducts with openings.
Intake of air can be carried out through branches, equipped with nozzles, which direct the supply air masses. The volume of air supplied regulates gates or valves located in the branches.
Mechanical local ventilation
Local mechanical ventilation acting in a confined space is called air showering. This type of ventilation is used in those working areas where the radiant heat is more than 300 kcal / h. or production is associated with toxin secretions that cannot be removed with a local exhaust.
The shower installations are mobile and stationary. First, when providing the workplace with clean air, they take it from the premises. Sometimes water is sprayed into the sprayed air mass. When it gets on the human body, its drops become an additional coolant. The second through the shower nozzles serves clean outdoor air or pre-treated.
General Exhaust Ventilation
Removing exhaust air from a room is a task of exhaust ventilation. The removal of used air from the room occurs due to a decrease in pressure in it. Thus, conditions are created for air to enter it outside or from an adjacent room.
The exhaust ventilation system includes a cleaning device (1) a fan (2) air ducts - a central (3) suction (4). When there is no other type of ventilation in the room ‚except for exhaust‚ the pressure in it drops to a mark lower than in adjacent rooms or lower than outside
When designing a general exchange hood for production workshops, it is taken into account that the elimination of dirty air must be carried out directly from the original source of the formation of harmful secretions in the direction of their natural trajectory and do not pollute clean areas. Such places are biological laboratories ‚workshops with harmful conditions.
Mechanical forced-air ventilation
The basis of the exhaust ventilation are 2 streams, moving towards each other. It consists of two independent systems - supply and exhaust systems, or from one unit. All equipment necessary for work and on the supply and exhaust is built into it.
If there are 2 separate systems, ventilation works without recirculation and is called open-circuited. The ventilation system of the second type is called closed, and it works with recycling.
A system with recirculation saves energy consumed to cool or heat the air ‚because the air mass is not fully heated, but only its volume that enters from the outside. The removed air in the system with recirculation returns to the room again with an admixture of fresh air, which makes up 10-15% of the total air mass.
The device of such ventilation is possible in places where there is no dangerous pollution. In regions with cold climates, a closed system is ineffective because recirculation and outdoor air masses do not mix well enough.
Mechanical ventilation in case of accident
In case of non-standard situations in addition to the working variant, they arrange emergency ventilation. Invariably, it is always exhaust. Mechanical emergency ventilation is installed in rooms where there is a threat of a breakthrough of explosive vapors or gases. In this case, explosion and explosion proof fans are installed.
The axial explosion-proof fan contains an engine in an explosion-proof casing. It is fixed so that if necessary it can be quickly replaced
There are such dangerous components that cannot be removed with the help of fans. Then the system includes an ejector. The activation of emergency ventilation should occur automatically as soon as the main ventilation stops working. Opening of openings ‚through which dirty air will go away must be carried out remotely.
Nozzles and grids intended for air outlet during emergency ventilation are placed in places of the most probable concentration of hazardous substances in a large volume. Openings through which air is removed in an emergency order ‚should not be in areas where people are constantly located. Umbrellas must not be installed on the pipes and shafts of the emergency system.
Emissions, accidentally released into the atmosphere, need to be dispersed as much as possible and not allowed to fall into the closed zones of the territory adjacent to the building. MACs are monitored by gas analyzers, adjusted accordingly.
Ventilation against smoke
The main task of smoke-free ventilation is to remove smoke from a room or a building as quickly as possible ‚to block its distribution and thereby protect people when they are evacuated.
In the photo - a diagram of the action of smoke ventilation. It is mounted in addition to the main ventilation ‚to ensure the evacuation of people in case of fire and cut off the paths of smoke spreading.
Such ventilation is installed where, with the constant presence of a large number of people, air cannot flow in a natural way. These are elevators, staircases, blind corridors and similar places. The basis of the smoke ventilation is laid supply and exhaust circuit.
Channels, powerful fans that are part of the ventilation, have high fire resistance and the ability to resist deformation under the prolonged action of high temperatures.
The system sections are equipped with two types of valves - anti-smoke and fire suppressor. Components of the smoke-free system are also durable screens and doors impermeable to gases and smoke.
In order to avoid trouble during the evacuation of people, 2 types of control are put into the design of smoke-proof ventilation - automatic and remote manual.
The system must include elements that indicate the occurrence of a fire:
- detectors, when activated, the automatic opening of the exhaust fans and smoke valves occurs;
- “Fire” signal on the central console;
- manual smoke ventilation.
Smoke valves distribute evenly under the ceiling. Coverage area should not exceed 900 m². The system is zoned on the section ‚and in addition to the hatches and valves‚ they equip smoke exhausters.
It not only removes smoke ‚but also removes carbon monoxide‚ small suspensions formed during combustion. Read more about the installation of the smoke removal system can be read. in this material.
Conclusions and useful video on the topic
This video is a kind of educational program about ventilation. Here, the very concept of ventilation is considered in detail and covers all issues related to its competent design:
Master class on installation of the ventilation system:
Both business leaders and private developers should understand that the normal functioning of those who they are responsible for depends on the efficiency of ventilation. Sometimes people’s lives are in question. To miss this moment and save it can not.
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