Description:

The quality of the air we breathe depends on the efficiency of ventilation. Underestimation of the influence of air exchange on the state of the air environment in residential apartments leads to a significant deterioration in the well-being of the people living in them.

Natural ventilation of residential buildings

E. Kh. Kitaitseva, associate professors of Moscow State University of Civil Engineering

E. G. Malyavina, associate professors of Moscow State University of Civil Engineering

The quality of the air we breathe depends on the efficiency of ventilation. Underestimation of the influence of air exchange on the state of the air environment in residential apartments leads to a significant deterioration in the well-being of the people living in them.

SNiP 2.08.01-89 "Residential buildings" recommends the following air exchange scheme for apartments: outside air enters through the open windows of living rooms and is removed through exhaust grills installed in kitchens, bathrooms and toilets. The air exchange of the apartment must be at least one of two values: the total exhaust rate from the toilets, bathrooms and kitchen, which, depending on the type of stove, is 110 - 140 m 3 / h, or the inflow rate equal to 3 m 3 / h for each m 2 of living space. In standard apartments, as a rule, the first version of the norm turns out to be decisive, in individual apartments - the second. Since this version of the norm for large apartments leads to unreasonably high ventilation air consumption, the Moscow regional norms MGSN 3.01-96 "Residential buildings" provide for air exchange in living rooms with a flow rate of 30 m 3 / h per person. In most cases, design organizations interpret this standard as 30 m 3 / h per room. As a result, in large municipal (not elite) apartments, air exchange can be underestimated.

In residential buildings of mass development, natural exhaust ventilation is traditionally performed. At the beginning of mass housing construction, ventilation was used with individual ducts from each exhaust grille, which were connected to the exhaust shaft directly or through a collection duct in the attic. In buildings up to four floors, this scheme is still used today. In high houses, to save space, every four to five floors, several vertical channels were combined with one horizontal one, from which the air was then directed to the mine through one vertical channel.

At present, the principal solution for natural exhaust ventilation systems in multi-storey buildings is a scheme that includes a vertical collection channel - "trunk" - with side branches - "satellites". Air enters the side branch through an exhaust opening located in the kitchen, bathroom or toilet and, as a rule, in the interfloor ceiling above the next floor is bypassed into the main collection channel. Such a scheme is much more compact than a system with individual channels, can be aerodynamically stable and meets the requirements of fire safety.

Each vertical of apartments can have two "trunks": one for transit of air from kitchens, the other from toilets and bathrooms. It is allowed to use one "stem" for ventilation of kitchens and sanitary cabins, provided that the place of connection of the side branches to the collection channel at one level must be at least 2 m above the level of the serviced premises. One or two last floors often have individual channels that are not connected with a common main "trunk". This happens if it is structurally impossible to connect the upper side channels to the main channel according to the general scheme.

In typical buildings, the main element of the natural ventilation system is a floor ventilation unit. In buildings built according to individual projects, exhaust air ducts are most often made in metal.

The ventilation unit includes a section of the main channel of one or more side branches, as well as an opening connecting the ventilation unit with the serviced premises. Now the side branches are connected to the main channel through 1 floor, while earlier solutions provided for connection through 2 - 3 and even 5 floors. The interfloor joint of ventilation units is one of the most unreliable places in the exhaust ventilation system. To seal it, cement mortar is still sometimes used, laid in place along the upper end of the underlying block. When installing the next block, the solution is squeezed out and partially overlaps the cross section of the ventilation ducts, as a result of which their resistance characteristic changes. In addition, there were cases of leaky sealing of the joint between the blocks. All this leads not only to an undesirable redistribution of air flows, but also to the flow of air through the ventilation network from one apartment to another. The use of special sealants still leads to the desired result in terms of the complexity of the sealing operation with the inaccessibility of the seam.

In order to reduce heat loss through the ceiling of the upper floor and to increase the temperature on its inner surface, most typical projects of multi-storey buildings provide for the installation of a "warm attic" about 1.9 m high. Air enters it from several prefabricated vertical channels, which makes the attic a common horizontal area ventilation systems. Removal of air from the attic space is carried out through one exhaust shaft for each section of the house, the mouth of which, in accordance with SNiP "Residential Buildings", is located 4.5 m above the ceiling above the last floor.

At the same time, the exhaust air in the attic should not cool down, otherwise its density increases, which leads to the overturning of the circulation or a decrease in the exhaust flow rate. At the floor of the attic above the ventilation unit, a head is arranged, inside which, as a rule, the side channels of the last floor are connected to the main one. When leaving the head in the "barrel" the air moves at a high speed, therefore, due to ejection, exhaust air is sucked into it from the side channels of the last floor.

Since the same ventilation units are used in buildings from 10 to 25 floors, for a 10 - 12-story building, the air velocity in the main channel when entering the "warm attic" is insufficient to eject air from the side branch of the upper floor. As a result, in the absence of wind or when the wind is directed to the facade opposite to the apartment in question, it is not uncommon for the circulation to overturn and blow the exhaust air of other apartments into the apartments of the top floor.

Calculated for natural ventilation is the mode of open windows at an outside temperature of +5 ° C and calm weather. When the outside temperature drops, the draft increases, and it is believed that the ventilation of the apartments only improves. The system is calculated in isolation from the building. At the same time, the flow rate of the air removed by the system is only one component of the air balance of the apartment, in which, in addition to it, the flow rate of air infiltrating or exfiltrating through the windows and entering or leaving the apartment through the front door can play a significant role. Under different weather conditions and wind directions, open or closed windows, the components of this balance are redistributed.

In addition to the design solutions of the system itself and weather conditions - temperature and wind - the operation of natural ventilation is influenced by the height of the building, the layout of the apartment, its connection with the staircase and elevator assembly, the size and breathability of windows and entrance doors to the apartment. Therefore, the norms for the density and size of these fences should also be considered relevant to ventilation, as well as recommendations for the layout of apartments.

The air environment in the apartment will be better if the apartment is provided with through or corner ventilation. This norm according to SNiP "Residential buildings" is mandatory only for buildings designed for III and IV climatic regions. However, at present, even for central Russia, architects are trying to place apartments in the building so that they satisfy this condition.

The entrance doors to the apartments of SNiP "om "Construction Heat Engineering" are required to have high tightness, ensuring air permeability of no more than 1.5 kg / h m 2, which should practically cut off the apartment from the staircase and elevator shaft. In real conditions, achieve the required density of apartment doors It is far from always possible. Based on numerous studies conducted in the 80s by the TsNIIEP of engineering equipment, MNIITEP, it is known that, depending on the degree of sealing of the door porches, the values ​​of their aerodynamic resistance characteristics differ by almost 6 times. Leakage of apartment doors causes the problem of the flow of exhaust air from the apartments of the lower floors along the staircase to the apartments of the upper floors, as a result of which, even with a well-functioning exhaust ventilation, the supply of fresh air is significantly reduced. In buildings with a one-sided arrangement of apartments, this problem is exacerbated. The scheme of air flow formation in a multi-storey building with loose apartment doors is shown in Fig. 1. One of the ways to combat the flow of air through the stairwell and the elevator shaft is the arrangement of floor corridors or halls with a door separating the stair-elevator unit from the apartments. However, such a solution, with loose apartment doors, enhances the horizontal flow of air from one-sided apartments facing the windward facade into apartments with a windward orientation.

Formation of air flows in a multi-storey building

The air permeability of windows of residential buildings according to SNiP "Construction Heat Engineering" should not exceed 5 kg / h m 2 for plastic and aluminum windows, 6 kg / h m 2 - for wooden ones. Their dimensions, based on the norms of illumination, are determined by the SNiP "Residential Buildings", limiting the ratio of the area of ​​​​light openings of all living rooms and kitchens of the apartment to the floor area of ​​\u200b\u200bthese premises to a value of no more than 1: 5.5.

With natural exhaust ventilation, windows play the role of supply devices. On the one hand, the low air permeability of windows leads to an undesirable reduction in air exchange, and on the other hand, to saving heat for heating the infiltration air. With insufficient infiltration, ventilation is carried out through open windows. The inability to adjust the position of the window vents forces residents to sometimes use them only for short-term ventilation of the premises, even with noticeable stuffiness in the apartment.

An alternative option for an unorganized inflow is the supply devices of various designs installed directly in the external fences. Rational placement of supply units in combination with the ability to adjust the supply air flow allows us to consider their installation as quite promising.

Field studies and numerous calculations of the air regime of the building made it possible to identify general trends in the changes in the components of the air balance of apartments under changing weather conditions for various buildings.

Aeromat accommodation options

With a decrease in the outdoor temperature, the share of the gravitational component in the pressure difference outside and inside the residential building increases, which leads to an increase in the cost of infiltration through windows on all floors of the building. More significantly, this increase affects the lower floors of the building. An increase in wind speed at a constant outdoor temperature causes an increase in pressure only on the windward facade of the building. The change in wind speed most strongly affects the pressure drops of the upper floors of tall buildings. Wind speed and direction have a stronger effect on the distribution of air flows in the ventilation system and infiltration rates than the outdoor temperature. Changing the outdoor temperature from -15°C to -30°C leads to the same increase in air exchange in the apartment as an increase in wind speed from 3 to 3.6 m/s. The increase in wind speed does not affect the flow of air removed from the apartment of the windward facade, however, with bad entrance doors, the inflow into them decreases through the windows and increases through the entrance doors. The influence of gravitational pressure, wind, layout, resistance to air penetration of internal and external enclosing structures for high-rise buildings is more pronounced than in low-rise and medium-rise buildings.

In connection with the installation of dense windows in the building, the installation of an exhaust system only turns out to be ineffective. Therefore, to supply the inflow to the apartments, both various devices are used (special aeromats in the windows, which have a rather large aerodynamic resistance and do not let in noise from the street (Fig. 2), supply valves in the outer walls (Fig. 3), and mechanical supply ventilation is designed .

Abroad, mechanical exhaust ventilation systems have become widespread in housing construction, especially for high-rise buildings. These systems are distinguished by stable operation in all periods of the year. The presence of low noise and reliable roof fans (similar fans are also equipped with garbage chute shafts) has made such systems quite widespread. As a rule, air mats are installed in window frames for air flow.

Unfortunately, domestic experience in the use of mechanical ventilation systems common to a building or riser is associated with a number of problems, as evidenced by the example of operation in Moscow of dozens of 22-storey buildings of the I-700A series. According to the state of the air environment, at one time they were recognized as emergency. The result of structural and installation defects, as well as poor operation (non-working fans) is insufficient air removal from all apartments in general and its flow from one apartment to another through a non-working system. Other shortcomings associated with the poor tightness of the systems and the complexity of their installation adjustment were also noted.

In the best position, in terms of fan operation, are apartments with individual fans. These include apartments in a number of typical buildings, where small axial fans are installed in individual exhaust ducts on the top floors.

A large number of complaints about the operation of natural ventilation systems made it legitimate to ask: can such a system work well under various weather conditions? It was decided to get the answer to this question by the method of mathematical modeling by jointly considering the air regime of all rooms of the building with a ventilation system, which makes it possible to identify a reliable qualitative and quantitative picture of the distribution of air flows in the building and the ventilation system.

For the study, an 11-storey one-entrance building was chosen, in which all apartments have corner ventilation. The last two floors are occupied by duplex apartments. The areas of the windows and their air permeability in the building correspond to the norms, as well as the air permeability of the doors (the air permeability of the windows of the 1st floor was 6 kg/h m 2 , and the air permeability of the doors was 1.5 kg/h m 2). There are windows in the stairwell on all floors. Each apartment has two "trunks" of natural exhaust ventilation systems made of metal. All ventilation systems were accepted as designed by the design organization. The main channels are provided with the same diameter in height. The diameters of the side branches are also made the same. Diaphragms were selected for the side branches, which equalize the exhaust air flow rates across the floors. The height of the shaft above the floor of the upper technical floor rises by 4 m.

The calculation determined the air flow rates that make up the air balance of each apartment at various outside temperatures, wind speeds and with open and closed windows.

In addition to the main option described above, options were considered with apartment doors corresponding to an air permeability of 15 kg / h m 2 at a pressure difference of 10 Pa and with windows providing an air permeability of 10 kg / h m 2 on the ground floor at an outside temperature of -26 ° C .

The calculation results for an apartment with the required exhaust flow rate of 120 m 3 /h m 2 are shown in fig. 4.

Figure 4a shows that with normative windows and doors and closed vents, the flow rates of air removed through the exhaust ventilation are almost equal to the flow rates of infiltration air during the entire heating season in windy and calm conditions. There is practically no air movement through the apartment doors (all doors work for inflow with a flow rate of 0.5 - 3 m 3 / h m 2). Infiltration is observed through the windows of the windward and leeward facades. The costs on the top floor refer to the duplex apartment, which explains the increased costs. It can be seen that ventilation works quite evenly, but with closed windows, air exchange rates are not met even at an outside temperature of -26 ° C and a head wind of 4 m / s on one of the facades of the apartment.

On fig. 4b shows the change in air flow rates of the same version of the fences in the building, but with open windows. The doors still isolate the apartments of all floors from the stairwell. At +5°С and calm air exchange of apartments is close to the standard one with a slight overflow on the first floors (curves 3). At an outside air temperature of -26°C and a wind of 4 m/s, air exchange exceeds the standard by 2.5 - 2.9 times. Moreover, the vents of the windward facade (curve 1n) work for inflow, and the side windows - for exhaust (curve 1b). The ventilation system removes air with a large overflow. The same figure shows the air flow rates in the warm period of the year (outside air temperature according to parameters A). The difference between the temperatures of the outdoor and indoor air is 3°C. At a wind speed of 3 m/s, air enters through the windows of one facade (curve 5n), and it is removed through the windows of the other (curve 5b). Air exchange is sufficient. When there is no wind (or with a windy facade), all windows compensate for the exhaust, which is from 35 to 50% of the norm (curves 4).

Figures 4c and 4d illustrate the same modes as figures 4a and 4b, but with doors with increased air permeability. It can be seen that ventilation is still working steadily. When the windows are closed, the flow of air through the apartment doors is insignificant, when open - in the lower floors, the air leaves through the doors to the stairwell, in the upper floors it enters the apartments. On fig. 4d, the air flow through the doors refers to options 1 and 5. In options 3 and 4, the air flow through the doors is negligible.

Variants of windows and doors of increased air permeability with closed windows are shown in fig. 4d. Calculations show that with breathable windows, infiltration ensures the ventilation rate of air only in the coldest period of the year.

Conclusion

In double-sided apartments, natural ventilation can work well for most of the year if properly sized and installed. In hot weather, only the effect of wind can provide the required air exchange.

Modern standards of air permeability of windows make you think about special measures to ensure the flow of outside air into apartments.

A significant improvement in the air regime of residential buildings can be achieved if the air permeability of apartment doors is brought closer to the standard. On the one hand, the air permeability rate could even be slightly increased, and on the other hand, it is necessary to give an approach to calculating the required air permeability of apartment doors. Now it is impossible to choose doors that meet the norm for buildings of various heights and layouts, taking into account climatic factors.

Ventilation of residential buildings is one of the key points in providing a comfortable air environment for people. Poor air circulation in the home can not only adversely affect the health of the occupants, but also require waste on additional exhaust systems. Operating air ducts are also one of the main points for ensuring fire safety. In this material, we will explain how ventilation is arranged in an apartment building and what measures can increase its efficiency.

Purpose of general house ventilation

The air in a residential apartment is always subject to pollution. Smoke from cooking, fumes from the bathroom, unpleasant odors and dust - all this ends up in the air and creates unfavorable conditions for people's lives. Stale air can even lead to the development of diseases - asthma and allergies. That is why every apartment building must be equipped with a common ventilation system.

Functions of ventilation in a residential area:

• ensure the penetration of clean air into the apartments;
• together with the exhaust air, remove dust and other impurities harmful to health;
• regulate humidity in residential and utility rooms.

Most of the urban population of our country lives in prefabricated houses built back in the Soviet era, while others move to new buildings. Ensuring ventilation of residential buildings is a mandatory requirement in the construction of houses. However, the level of ventilation in multi-apartment residential buildings remains quite low. It is customary to save on air duct systems during construction.

At the moment, you can find the following types of ventilation in residential buildings:

• with natural inflow and exhaust;
• with forced air movement through ventilation installations.

In modern elite-class houses, heating and ventilation systems correspond to the latest standards and are created using special equipment and materials. For ventilation of multi-storey residential buildings of panel type, natural air exchange is used. The same applies to brick residential buildings of the Soviet era, as well as modern budget-class buildings. Air must enter through the holes between the doors and the floor, as well as special valves on the plastic windows.

Ventilation in a panel house works as follows. Air is discharged upwards through vertical ventilation shafts, thanks to natural draft. It is pulled outside the house through a pipe located on the roof or attic. When air enters the apartment through open windows or doors, it rushes to those located in the kitchen and bathroom - where cleansing from smoke and moisture is most needed. Thus, stagnant air is discharged into the pipe, and clean air enters the room through the windows.

If you stop the flow of fresh air, ventilation will not work efficiently. Residents of apartments in apartment buildings often forget about the natural ventilation of the premises when they install additional exhaust systems. Here is a list of typical mistakes during repairs that stop air circulation:

• installation of deaf double-glazed windows made of metal-plastic;
• elimination of the gap between the door leaf and floors when replacing interior doors;
• installation of axial fans in the toilet (affects the ventilation of neighboring apartments).

When decorating living rooms, it is worth remembering to create natural ways for ventilation. You can install plastic windows with special valves that will automatically supply air from the street.

Interior doors should be selected in size so that they do not stand close to the floor. When installing additional fans, you can also configure them for supply.

Ventilation schemes for residential buildings

Depending on the construction plans, ventilation can have a completely different design. In this section, we will try to figure out how ventilation is arranged in a panel house on the diagrams and talk about the degree of effectiveness of one or another type of its implementation.

The most successful ventilation scheme in a panel house is individual, when each apartment has a separate channel with access to the roof.

In this case, the ventilation shafts are not interconnected, it improves, and polluted air from neighboring apartments does not enter the house. Another variation of such a ventilation scheme in Khrushchev is that from each apartment, separate channels lead to the roof, where they are connected into a single pipe that brings air masses to the street.

Unfortunately, quite often the simplest, but inefficient method of ventilation is used, in which air from all apartments enters a single large shaft - just like ventilation is arranged in Khrushchev. This allows you to save space and costs during the construction of the building, but it has a lot of unpleasant consequences:

• the ingress of dust and unpleasant odors from other apartments - residents of the upper floors are especially susceptible to this, where the air rises naturally;
• rapid contamination of the common ventilation pipe;
• lack of sound insulation.

There are several other ways to remove air through ventilation shafts - with horizontal channels in the attic and the outlet of the pipe to the attic without a chimney. In the first case, horizontal air ducts reduce air draft, and in the second case, the attic is polluted due to the lack of outlet to the street. The ventilation scheme in Khrushchev and other Soviet-style buildings, although budgetary, is inconvenient for residents.

Schematic diagrams of some natural ventilation systems of residential buildings: (a) - without prefabricated ducts; (b) - with vertical collection channels; (c) - with horizontal collection channels in the attic; (d) - with a warm attic

Fortunately, there is a modern ventilation system that automatically draws and supplies air. Its design includes a fan that pumps air into the mine. It is usually located in the basement of the building. On the roof of the house there is an exhaust ventilation of the same power, which with force removes polluted air masses from the air duct. This is the simplest ventilation scheme in an apartment building. It can also be arranged with the use of energy-saving equipment - recuperators. The task of the heat exchanger is to take heat (or cold) from the exhaust air and transfer it to the supply air.

Ventilation shafts, as a rule, come from the basement of a multi-storey building, additionally providing its protection from dampness and fumes. Basement ventilation is provided by natural draft, and in modern houses air supply units are also installed here. To remove raw air from the basement, common ventilation shafts are used, which exit through openings on each floor and in each apartment.

Airing the basement, the place where the natural ventilation system begins, is one of the main conditions for its proper operation. To do this, holes are made in the basement walls through which fresh air enters the basement. It not only reduces humidity at the base of the house, but also creates traction in the common house mine.

The shape of the holes can be simple - round or square. They must be located at a sufficient distance above the ground so that water and dirt from the street do not get inside. The optimal distance from the ground is not less than 20 cm. The holes should be placed evenly around the perimeter of the basement, if there are several rooms in it, it is necessary to organize several air ducts in each. The vents must not be closed, otherwise the whole principle of the ventilation of an apartment building will be violated. From penetration into the basement of animals, the holes are covered with a metal mesh.

Calculation of apartment ventilation

Natural or artificial ventilation of a residential building is calculated by specialists during the construction of the building, and the residents of the building receive apartments with a ventilation system “by default”. It will not work to change the scheme of the ventilation system in Khrushchev, this will require serious intervention in the structure of the building. However, with the help of various devices, you can improve the air circulation in your apartment. For this it is necessary.

If you are not satisfied with the ventilation in the apartment, you can install additional hoods in the kitchen and fans on the grates in the bathroom. In this case, you should remember the basic rule - the amount of air drawn out should not exceed the amount entering the apartment. In this case, the ventilation systems will work as efficiently as possible. Some models of hoods and fans can work on the flow of air - they should be installed if the room is not sufficiently ventilated through windows and doors.

Particular attention should be paid to the power of exhaust devices; for small apartments, a capacity of 50 to 100 m³ of air per hour will be enough. To determine exactly what load for the device will be optimal, you can measure the amount of air masses in the room. To do this, the area of ​​\u200b\u200bthe apartment is summed up and multiplied by three. The resulting volumes of air must completely pass through the fans within an hour.

You can organize additional air flow with the help of air conditioners, hoods and fans. In combination, these devices will perform the main tasks of ventilation of premises:

• the hood in the kitchen will clean the room from unpleasant odors, grease and smoke, filling it with clean air;
• fan in the bathroom - to remove moist air;
• air conditioning - cool and dehumidify the air in the room.

These devices will ensure good circulation of air masses in different rooms and regulate their cleanliness - they are simply irreplaceable in the bathroom and kitchen.

The amount of supply air can exceed the volume of exhaust air by 15-20%, but not vice versa.

home ventilation maintenance

Often, due to clogging of the air duct or outlet grate, ventilation does not work. you can independently within your apartment by removing the grate and cleaning the pipe walls with a brush, broom or vacuum cleaner. Particular attention must be paid to the mesh that closes the entrance to the mine - it works like a filter on which all impurities remain.

Complete is carried out by a special service at the request of residents.

First, a diagnosis of the performance of the exhaust channels is carried out and a work plan is drawn up. To check the cleanliness of the mines, a video camera on a cable is often used - it allows you to determine the places where dirt accumulates and the places where the pipe is deformed.

After that, the cleaning of the duct begins. Professionals use weights, pneumatic brushes, weighted brushes and other tools. Ordinary residents should not engage in such work - this can harm the integrity of the pipe.

Natural ventilation in a high-rise building is not very efficient compared to mechanical ventilation, but it requires less cleaning. A team of specialists should be called every few years if there are obvious signs of contamination of the duct. Automatic ventilation systems are under heavy load and require more thorough cleaning. These systems are often maintained by the companies that install them.

Monitoring the performance and increasing the efficiency of home ventilation is one of the key points in creating a healthy microclimate in your home. By taking a number of measures to improve the ventilation of your home, you will save yourself from dust, unpleasant odors, kitchen or bathroom products in the air.

Regular ventilation of residential and public buildings ensures the timely removal of excess heat, moisture and harmful gaseous impurities that accumulate in the air as a result of people and various household processes.

The air of poorly ventilated dwellings and other enclosed spaces, due to changes in the chemical and bacterial composition, physical and other properties, can have a harmful effect on health, causing or worsening the course of diseases of the lungs, heart, kidneys, etc. It has been established that prolonged inhalation of such air in combination with unfavorable temperature-humidity and air-ion conditions significantly affects the nervous system and general well-being of a person (headache, loss of appetite, decreased performance, etc.). All this indicates the great hygienic importance of ventilation of residential premises, since clean air, according to F.F. Erisman, one of the first aesthetic needs of the human body.

The amount of necessary exchange of indoor air with outdoor air depends on the number of people in the room, its cubic capacity and the nature of the work being done. It can be determined on the basis of various indicators, and as one of them, common in sanitary practice when examining residential premises, the content of carbon dioxide is taken. Ventilation should not allow the excess of carbon dioxide in the room above 1% o, which is accepted as an acceptable concentration for ordinary residential premises, classrooms, hospital wards, etc.

The cleanliness of the air in the premises is determined by the provision for each person of the necessary volume of air - the so-called air cube - and its regular replacement with outside air. The amount of ventilation air required for this per person per hour is called ventilation volume.

In residential premises, the norm of the air cube is 25-27 m3, the volume of ventilation is 37.7 m3, therefore, in order to completely remove the spoiled air and replace it with clean atmospheric air, it is necessary to ensure approximately 1.5-2-fold exchange of indoor air with outdoor air during I h. Thus, the frequency of air exchange is the main criterion for the intensity of ventilation. It is calculated by dividing the amount of air entering the room for 1 hour by its cubic capacity.

In rooms where hard physical work is done, for example, in sports halls, the indicated size of the air cube and ventilation volume will be insufficient and the air exchange rate will increase, however, within the permissible values ​​that do not cause strong air currents. In children's institutions, the volume of ventilation may be less. It is also differentiated depending on the purpose of individual public buildings (hospitals, schools, etc.).

When rationing the volume of ventilation, sometimes instead of the frequency of air exchange, the amount of supply or exhaust air is indicated per person per hour.

Natural ventilation is the infiltration of outside air through various cracks and leaks in windows, doors, and partly through the pores of building materials in rooms, as well as their ventilation through open windows, vents and other openings arranged to enhance natural air exchange.

In both cases, air exchange occurs due to the difference in temperature between outdoor and indoor air and wind pressure. This exchange is most intense in an open building system, when the buildings are distant from each other and all four of their sides participate in the air exchange, and the rooms are located on two opposite facades, which creates through ventilation.

Air exchange due to infiltration provides only 0.5-0.75-fold air exchange for 1 hour. Since this is not enough, vents and transoms are used that fold at an angle of 45 ° into the room (Fig. 4.5). In this case, cold air enters the room first up, under the ceiling, and then, partially heated, goes down without forming sharp currents and without causing strong cooling of people. Form size

Rice. 4.5. Transom, a - intake of outside air; b - the flow of air into the room.

dots should be at least 1/50 of the floor area. In the cold season, ventilation is more effective with windows that are fully and often opened for 5-10 minutes than with windows that are ajar for a long time. You should not be afraid of a short-term decrease in the temperature in the room, since the walls and furnishings cool slightly during this time and after the ventilation is completed, the air temperature will quickly recover, the main thing is that in this case a more complete change of air will occur.

In multi-storey buildings, to enhance natural ventilation, exhaust ducts are arranged in the inner walls, in the upper part of which there are intake openings. The channels lead to the attic into the exhaust shaft, from which air enters. This ventilation system works on natural draft due to the pressure difference formed in the ducts due to the temperature difference, which causes the warmer room air to move upwards. In the cold season, a natural draft exhaust system can provide 1.5-2-fold air exchange per hour; in warm season, its efficiency is insignificant due to the small difference in temperature between indoor and outdoor air.

Artificial ventilation. In public buildings designed to accommodate a large number of people, in hospitals, schools, and in production, natural ventilation alone is not enough to ensure the proper sanitary condition of the air. In addition, in hospitals and children's institutions during the cold season, it is not always possible to widely use it due to the danger of the formation of cold air currents. In this regard, mechanical ventilation is arranged, which does not depend on the outside temperature and wind pressure and provides, under certain conditions, heating, cooling and cleaning of the outside air. Ventilation can be local - for one room and central - for the entire building.

For local ventilation, supply or exhaust electric fans are used, which are installed in windows or wall openings. In public buildings, they are designed mainly for short-term action. In classrooms, gyms, fans operate during breaks between classes, and in a number of rooms with polluted air - periodically. In production, they function for a longer time. Most often, local exhaust ventilation is used, which removes spoiled air, and the influx of clean air is carried out by entering through windows and vents. In rooms with high air pollution (kitchens, toilets), only exhaust fans are installed.

However, local ventilation has certain disadvantages. When using the supply system in winter, cold air currents are formed in the room, the operation of the fan

Rice. 4.6. Scheme of the supply of o-exhaust artificial central ventilation.

the moat is often accompanied by significant noise, they spoil the appearance of the premises. The most modern type of local ventilation are air conditioning units.

Central ventilation is designed for air exchange in the entire building or in its main premises, it operates constantly or for most of the day. Depending on the purpose of the premises, central ventilation can be supply, exhaust or supply and exhaust, combining the supply of clean air with the removal of spoiled.

On fig. 4.6 shows a diagram of the supply and exhaust ventilation. Outside clean air, for example from a garden, is taken with the help of fans, sometimes at a considerable distance from the building, and is directed through the channel to the supply chamber, where it is cleaned of dust, passing through fabric or other filters. In the cold season, the air is heated to 12-14 ° C, in some cases it is humidified and supplied to the premises through channels in the inner walls. The supply ducts end with openings in the upper part of the walls to exclude the direct effect of colder air currents on people, and are covered with gratings. To remove spoiled air, another exhaust network of channels is laid, the openings of which are located in the lower part of the opposite inner wall; the channels lead to the attic into a common collector, from which air is removed to the outside using a fan.

The supply and exhaust ventilation system ensures the predominance of air inflow over the exhaust, which is especially important in operating rooms of hospitals. In showers, toilets, kitchens, as already mentioned, only an exhaust hood is arranged. In order to save money, many buildings also arrange only exhaust ventilation with the expectation that clean air enters through the vents,

From a hygienic point of view, a supply and exhaust ventilation system is more preferable, which provides an influx of clean heated and, if necessary, humidified air, which makes it possible to better maintain a normal temperature and humidity regime in the premises.

At present, a new, more advanced ventilation system has been developed - air conditioning, which allows you to automatically maintain optimal conditions for temperature, humidity, movement and air purity for the required time. For this, central air conditioning units are used, designed to service public buildings (hospitals, schools, etc.), railway cars, and room air conditioners for individual small-sized premises.

On fig. 4.7 is a diagram of an air conditioning unit. The outside air entering the air conditioners is heated or cooled to the required temperature, humidified

Rice. 4.7. Scheme of installation for air conditioning.

I - hole for suction of outside air; 2 - a hole for air to enter the room; 3 - filter; 4 - nozzles; 5 - a pipe supplying air to the nozzles; 6 - pipeline for supplying fresh chilled or heated water to the system; 7 - pump; 8 - electric motor; 9 - humidification chambers.

This article will consider the purpose and classification of ventilation systems for residential premises. We will tell you how to calculate the ventilation system and give an example of the calculation of ventilation systems. Consider how to check whether ventilation is working and give a detailed method for calculating ventilation systems.

Classification of ventilation systems

Ventilation systems of residential and public buildings can be classified into three categories: according to their functional purpose, according to the method of inducing air movement and according to the method of air movement.

Types of ventilation systems by function:

1. Supply ventilation system (ventilation system that provides fresh air to the room);
2. Exhaust ventilation system (ventilation system that removes exhaust air from the room);
3. Recirculation ventilation system (ventilation system that provides fresh air to the room with a partial admixture of exhaust air).

Types of ventilation systems according to the method of inducing air movement:

1. With mechanical or artificial (these are ventilation systems in which air is moved using a fan);
2. With natural or natural (air movement is carried out due to the action of gravitational forces).

Types of ventilation systems by way of air movement:

1. Duct (air movement is carried out through a network of air ducts and channels);
2. Channelless (air enters the room in an unorganized manner, through leaky window openings, open windows, doors).

What are the risks of poor ventilation?

If there is insufficient flow in the house, then the room will experience a lack of oxygen, high humidity or dryness (depending on the time of year) and dustiness.

Fogging windows due to insufficient ventilation

If there is insufficient exhaust in the house, then there will be increased humidity, greasy soot on the walls of the kitchen, fogging of windows in the winter, a fungus on the walls, especially the bathroom and toilet, as well as walls covered with wallpaper, is possible.

Fungus on wallpaper with insufficient ventilation

And as a consequence, an increased risk of diseases of the cardiovascular and respiratory systems. In addition, most furniture and finishing materials constantly release hazardous chemical compounds into the air. Their MPC (maximum permissible concentration) in the sanitary and hygienic conclusions for this furniture and finishing materials is set from the conditions of compliance with ventilation standards. And the worse the ventilation works, the more the concentration of these harmful substances in the air at home increases. Therefore, the health of the residents of the house directly depends on ensuring proper ventilation.

How to check if your ventilation is working?

First of all, you can check if the hood is working. To do this, hold a lighter or a piece of paper to the ventilation grill installed in the wall of the bathroom or in the kitchen. If the flame (or a piece of paper) is bent towards the grate, then there is a draft, the hood is working. If not, then the channel is blocked, for example, clogged with leaves through the duct. If you have an apartment, then the neighbors could block it, making redevelopment of the premises. Therefore, your first task is to provide draft in the ventilation duct.

Checking ventilation for draft with a lighter

If there is a draft, but it is not constant, and neighbors live above or below you. In this case, air can flow to you, from neighboring rooms, carrying odors with it. In this situation, it is necessary to equip the hood with a non-return valve or an automatic shutter, which closes when the back draft is drawn.

How to check whether you have a sufficient section of the hood, we will consider further.

Calculation of air exchange. Formula for calculating ventilation

In order to choose the ventilation system we need, we need to know how much air must be supplied or removed from a particular room. In simple words, you need to know the air exchange in a room or in a group of rooms. This will make it clear how to calculate the ventilation system, select the type and model of the fan and calculate the air ducts.

There are many options for how to calculate air exchange, for example, to remove excess heat, to remove moisture, to dilute contaminants to MPC (maximum permissible concentration). All of them require special knowledge, the ability to use tables and diagrams. It should be noted that there are state regulations, such as SanPins, GOSTs, SNiPs and DBNs, which clearly define what ventilation systems should be in certain rooms, what equipment should be used in them and where it should be located. And also, how much air, with what parameters and by what principle should they be supplied and removed. When designing ventilation systems, each engineer carries out calculations in accordance with the above-mentioned standards. To calculate the air exchange in residential premises, we will also be guided by these standards and use the two simplest methods for finding air exchange: by the area of ​​\u200b\u200bthe room, by sanitary and hygienic standards and air exchange by multiplicity.

Calculation by room area

This is the simplest calculation. The calculation of ventilation by area is done on the basis that for residential premises the norms regulate the supply of 3 m 3 / hour of fresh air per 1 m 2 of the area of ​​\u200b\u200bthe room, regardless of the number of people.

Calculation according to sanitary and hygienic standards.

According to sanitary standards for public and administrative buildings, 60 m 3 / hour of fresh air is needed per person permanently staying in the room, and 20 m 3 / hour for one temporary one.

Calculation by multiplicities

In the regulation, namely Table 4 DBN V.2.2-15-2005 Residential buildings there is a table with the given multiplicities for the premises (Table 1), we will use them in this calculation (for Russia, these data are given in SNiP 2.08.01-89* Residential buildings, Appendix 4).

Table 1. Air exchange rates in the premises of residential buildings.

Premises	Estimated temperature in winter, ºС	air exchange requirements
		tributary	Hood
common room, bedroom, office	20	1x	--
Kitchen	18	-	According to the air balance of the apartment, but not less than, m 3 / hour	90
Kitchen-dining room	20	1x
Bathroom	25	-		25
Restroom	20	-		50
Combined bathroom	25	-		50
Swimming pool	25	By calculation
Washing machine room in the apartment	18	-	0.5 times
Dressing room for cleaning and ironing clothes	18	-	1.5x
Vestibule, common corridor, stairwell, entrance hall of the apartment	16	-	-
Premises for staff on duty (concierge / concierge)	18	1x	-
Smoke-free staircase	14	-	-
Elevator machine room	14	-	0.5 times
Garbage chamber	5	-	1x
parking garage	5	-	By calculation
Switchboard	5	-	0.5 times

Air exchange rate- this is a value, the value of which shows how many times within one hour the air in the room is completely replaced by a new one. It directly depends on the specific room (its volume). That is, a single air exchange is when fresh air was supplied to the room for an hour and “exhaust” air was removed in an amount equal to one volume of the room; 0.5 crane air exchange - half the volume of the room. In this table, the last two columns indicate the multiplicity and requirements for air exchange in the premises for air supply and exhaust, respectively. So, the formula for calculating ventilation, including the required amount of air, looks like this:

L=n*V(m 3 / hour), where

n- normalized air exchange rate, hour-1;

V- the volume of the room, m 3.

When we consider air exchange for a group of rooms within the same building (for example, a residential apartment) or for a building as a whole (cottage), they must be considered as a single air volume. This volume must meet the condition ∑ L pr = ∑ L you are t That is, how much air we supply, the same must be removed.

Thus, the sequence of calculation of ventilation by multiplicity next:

1. We consider the volume of each room in the house ( volume=height*length*width).
2. We calculate the volume of air for each room using the formula: L=n*V.

To do this, we first select from table 1 the rate of air exchange for each room. For most rooms, only the supply or only the exhaust is normalized. For some, such as a kitchen-dining room and both. A dash means that air should not be supplied (removed) to this room.
For those rooms for which the minimum air exchange is indicated in the table instead of the value of the air exchange rate (for example, ≥90 m 3 /h for the kitchen), we consider the required air exchange equal to this recommended one. At the very end of the calculation, if the balance equation (∑ L pr and ∑ L vyt) does not converge with us, then we can increase the air exchange values ​​\u200b\u200bfor these rooms to the required figure.

If there is no room in the table, then we consider the air exchange rate for it, given that for residential premises the norms regulate the supply of 3 m 3 /hour of fresh air per 1 m 2 area of ​​the room. Those. we consider the air exchange for such rooms according to the formula:L=S rooms *3.

All values Lround up to 5, i.e. values ​​must be a multiple of 5.

1. Summarizing separately L of those premises L of those premises, for which the drawing is normalized. We get 2 numbers: ∑ L pr and ∑ L vyt.
2. We draw up a balance equation ∑ L pr = ∑ L you are t.

If a ∑ L pr > ∑ L vy, then to increase∑ L vyt up to value ∑ L prwe increase the air exchange values ​​for those rooms for which we took the air exchange equal to the minimum allowable value in paragraph 3.
Let's consider the calculations with examples.

Example 1: Calculation by multiplicities.

There is a house with an area of ​​140 m 2 with premises: a kitchen (s 1 \u003d 20 m 2), a bedroom (s 2 \u003d 24 m 2), an office (s 3 \u003d 16 m 2), a living room (s 4 \u003d 40 m 2), a corridor (s 5 \u003d 8 m 2), bathroom (s 6 \u003d 2 m 2), bathroom (s 7 \u003d 4 m 2), ceiling height h \u003d 3.5 m. It is necessary to draw up an air balance at home.

1. We find the volume of rooms according to the formula V=s n*h, they will be V 1 = 70 m 3, V 2 = 84 m 3, V 3 = 56 m 3, V 4 = 140 m 3, V 5 = 28 m 3, V 6 = 7 m 3, V 7 = 14 m 3 .
2. Now we calculate the required amount of air in multiplicity (formula L=n*V) and write it down in the table, having previously rounded the unit part to five up. When calculating the multiplicity n, we take from table 1, we obtain the following values ​​​​of the required amount of air L:

Table 2. Calculation by multiplicities.

Note: In table 1 there is no position that would regulate the frequency of air exchange in the living room. Therefore, we consider the air exchange rate for it, given that for residential premises the norms regulate the supply of 3 m 3 / hour of fresh air per 1 m 2 of the area of ​​\u200b\u200bthe room. Those. count according to the formula: L=S rooms *3.

Thus, L pr.living room = S living room*3 \u003d 40 * 3 \u003d 120 m 3 / hour.

1. Summarizing separately L those rooms, for which the air flow is normalized, and separately L those rooms, for which the extract is normalized:

∑ L at t \u003d 85 + 60 + 120 \u003d 265 m 3 / hour;
∑ L vyt\u003d 90 + 50 + 25 \u003d 165 m 3 / hour.

4. Let's make the equation of air balance. As we see∑ L int > ∑ L out, so we increase the valueL vytof the room where we took the value of air exchange equal to the minimum allowable. We have all three rooms (kitchen, bathroom, bathroom). Let's increaseL vytfor the kitchen up to valueL kitchen=190. Thus, the total∑ L you t \u003d 265m 3 /hour. Table condition 1(tab. 4 DBN V.2.2-15-2005 Residential buildings ) done: ∑ L pr \u003d ∑ L vyt.

It should be noted that in the rooms of the bathroom, bathroom and kitchen, we organize only an exhaust hood, without inflow, and in the rooms of the bedroom, study and living room, only inflow. This is to prevent the flow of hazards in the form of unpleasant odors into the living quarters. Also, this can be seen from Table 1, in the cells of the inflow opposite these rooms there are dashes.

Example 2. Calculation according to sanitary standards.

The conditions remain the same. Just add the information that 2 people live in the house, and we will calculate according to sanitary standards.

Let me remind you that according to sanitary standards, 60 m 3 / hour of fresh air is needed for one person permanently staying in the room, and 20 m 3 / hour for one temporary one.

Let's get that for the bedroom L2\u003d 2 * 60 \u003d 120 m 3 / hour, for the office we will accept one permanent resident and one temporary L 3\u003d 1 * 60 + 1 * 20 \u003d 80 m 3 / hour. We accept two permanent residents and two temporary residents for the living room (as a rule, the number of permanent and temporary people is determined by the customer's terms of reference) L 4\u003d 2 * 60 + 2 * 20 \u003d 160 m 3 / hour, we will write the data obtained in the table.

Table 3. Calculation according to sanitary standards.

Composing the equation of air balances ∑ L pr \u003d ∑ L vyt:165<360 м 3 /час, видим, что количество приточного воздуха превышает вытяжной на L\u003d 195 m 3 / hour. Therefore, the amount of exhaust air must be increased by 195 m 3 /h. It can be evenly distributed between the kitchen, bathroom and bathroom, or it can be served in one of these three rooms, such as the kitchen. Those. in the table will change L exhaust kitchen i will make L exhaust kitchen\u003d 285 m 3 / hour. From the bedroom, study and living room, the air will flow into the bathroom, bathroom and kitchen, and from there it will be removed from the apartment by means of exhaust fans (if installed) or natural draft. Such overflow is necessary to prevent the spread of unpleasant odors and moisture. Thus, the air balance equation ∑ L pr = ∑ L you t: 360=360 m 3 /hour - performed.

Example 3. Calculation by the area of ​​​​the room.

We will make this calculation, given that for residential premises the norms regulate the supply of 3 m 3 / hour of fresh air per 1 m 2 of the area of ​​\u200b\u200bthe room. Those. we calculate the air exchange according to the formula: ∑ L= ∑ L pr = ∑ L ex = ∑ S room *3.

∑ L vyt 3\u003d 114 * 3 \u003d 342 m 3 / hour.

Comparison of calculations.

As we can see, the calculation options differ in the amount of air ( ∑ L vyt1\u003d 265 m 3 / hour< ∑ L vyt3\u003d 342 m 3 / hour< ∑ L vyt2\u003d 360 m 3 / hour). All three options are correct according to the rules. However, the first third is simpler and cheaper to implement, and the second is a little more expensive, but creates more comfortable conditions for a person. As a rule, when designing, the choice of calculation option depends on the desire of the customer, more precisely, on his budget.

Selection of the duct section

Now that we have calculated the air exchange, we can choose the ventilation system implementation scheme and calculate the ventilation system ducts.

Two types of rigid air ducts are used in ventilation systems - round and rectangular. In rectangular ducts, to reduce pressure loss and reduce noise, the aspect ratio should not exceed three to one (3:1). When choosing the section of air ducts, one should be guided by the fact that the speed in the main air duct should be up to 5 m/s, and in the branches up to 3 m/s. Calculate the dimensions of the duct section can be determined by the diagram below.

Diagram of the dependence of the cross-section of air ducts on the speed and air flow

In the diagram, the horizontal lines show the airflow value, and the vertical lines show the speed. Oblique lines correspond to the dimensions of the ducts.

We select the section of the branches of the main air duct (which go directly into each room) and the main air duct itself for supplying air with a flow rate L\u003d 360 m 3 / hour.

If the air duct is with natural air extraction, then the normalized air velocity in it should not exceed 1 m/h. If the air duct has a constantly working mechanical air exhaust, then the air velocity in it is higher and should not exceed 3 m/s (for branches) and 5 m/s for the main air duct.

We select the cross section of the duct with a constantly working mechanical air exhaust.

The costs are indicated on the left and right in the diagram, we choose ours (360 m 3 / hour). Further, we move horizontally until the intersection with the vertical line corresponding to the value of 5 m / s (for the maximum air duct). Now, along the line of speed we go down to the intersection with the nearest section line. We got that the section of the main air duct we need is 100x200 mm or Ø150 mm. To select the branch section, we move from a flow rate of 360 m 3 / h in a straight line to the intersection at a speed of 3 m 3 / h. We get a branch section of 160x200 mm or Ø 200 mm.

These diameters will be sufficient when installing only one exhaust duct, for example in the kitchen. If 3 exhaust ventilation ducts are installed in the house, for example, in the kitchen, bathroom and bathroom (rooms with the most polluted air), then we divide the total air flow that needs to be removed by the number of exhaust ducts, i.e. by 3. And already for this figure we select the cross section of the ducts.

According to this schedule, it is rather difficult to select sections for such small costs. We count them in a special program. Therefore, if you need - ask, we will calculate.

Natural air extraction. This diagram is suitable only for the selection of mechanical drawing sections. The natural hood is selected manually or using section selection programs. Again, please ask.

Note: In our example, it was not, but special attention should be paid to the location of the swimming pool when it is in the house. The pool is a room with an excess amount of moisture, and when calculating the necessary air exchange, an individual approach is required. From practice I can say that the consumption is obtained at least eight times. This is a rather high consumption, and if we take into account that the supply air temperature should be 1-2 ° C higher than the water temperature in the pool, then the cost of air heating in winter is very high. Therefore, for indoor swimming pools it is more logical to use dehumidification systems. These systems work according to the following scheme - the dehumidifier takes moist air from the room, passing it through itself, removes moisture from it (by cooling it), then heats it up to a predetermined temperature and feeds it back into the room. Also, there are systems of dehumidification of air with a possibility of admixture of fresh air.

The ventilation scheme is purely individual for each house and depends on the architectural features of the house, on the wishes of the customer, etc. Meanwhile, there are some conditions that must be observed, and they apply to all schemes without exception.

General requirements for ventilation systems

1. Exhaust air is thrown out above the roof. With natural exhaust ventilation, all channels lead above the roof. With mechanical exhaust ventilation - the air duct is also taken out above the roof either inside the building or outside.
2. The intake of fresh air with a mechanical supply ventilation system is carried out using an intake grille. It must be placed at least two meters above ground level.
3. The air movement must be organized in such a way that the air from the premises moves in the direction of the premises with the release of harmful substances (bathroom, bathroom, kitchen).

In this article, we have analyzed what ventilation systems are and how the required air exchange is calculated. This information will help you choose the right ventilation system and provide the most comfortable microclimate for living in your home.

In the Appendix to the article you will find normative documents that describe the issue of Ventilation from a regulatory point of view.

Organized natural ventilation in a residential building is an air exchange that occurs due to the difference in air density inside the building and outside, through specially arranged exhaust and supply openings.

For ventilation of premises in a residential building, a natural ventilation system is provided. Let's see how it works and how it works.

Natural ventilation device

Each entrance from the first floor to the last has a common ventilation duct that runs vertically from the bottom, up with access either to the attic or directly to the roof (depending on the project). Satellite channels are connected to the main ventilation duct, the beginning of which is located, as a rule, in the bathroom, kitchen and toilet.

Through these satellite channels, the "exhaust" air leaves the apartments, enters the common ventilation shaft, passes through it and is discharged into the atmosphere.

It seems that everything is extremely simple and such a mechanism should work flawlessly. But there are many things that can interfere with the normal operation of ventilation.

The most important thing in the work of natural ventilation is that air must be supplied to the apartment in sufficient quantities. According to the projects, according to SNiP, this air should enter through the "leaks" of window openings, as well as by opening the vents.

Extract from SNiP 2.08.01-89 (minimum air exchange parameters for an apartment).

But we all understand that modern windows in the closed state do not let in any sounds, let alone air. It turns out that you need to keep the windows open all the time, which of course is not possible for a number of reasons.

Causes of disruption of natural ventilation

• Re-equipment of ventilation channels

It happens that the ventilation stops working due to active neighbors who could simply break the ventilation duct to expand the living space. In this case, for all residents whose apartments are located below, the ventilation will stop working.

• Debris in the ventilation duct

It often happens that something gets into the ventilation shaft and simply does not allow air to move freely. If this happens, then you need to contact the appropriate structure, it is forbidden to climb into the ventilation duct on your own.

• Incorrect connection of exhaust hoods

Also a common problem is the connection of kitchen hoods (exhaust hoods) of high power to the satellite channel, which is not intended for this. And when such a hood is turned on, an air lock forms in the common ventilation duct, which disrupts the operation of the entire system.

• seasonality

Unfortunately, the operation of the natural ventilation system is also influenced by the temperature regime, in the cold season it works better, and in the summer, when the temperature rises outside, it works less. To this, several negative points described above are added, and the operation of the entire system comes to naught.

And of course, there are mistakes during construction made by the contractor for one reason or another ... Only the installation of supply and exhaust ventilation equipment will help here.

Natural ventilation operates all year round 24 hours a day. Therefore, a round-the-clock supply of air to the room is necessary. If it is not there, then in winter, when the windows are closed, condensation may occur, an increase in humidity up to the formation of mold, to avoid this, install supply valves, this will improve ventilation in the room and get rid of excess moisture.

For the organization of good air exchange in the apartment all year round. A ventilator will be required. Thanks to this device, you do not have to open windows, and fresh and clean air will always enter the apartment.