The work of natural ventilation in residential buildings. Ventilation in an apartment building: features of operation and cleaning procedure. Full forced air exchange

There are houses with a common ventilation duct in the bathroom. When such a channel is faulty, smells from neighboring apartments begin to enter the apartments. Management organizations must monitor the condition of the ventilation ducts and prevent such breakdowns. The Supreme Court of the Russian Federation once again reminded of this.

What is the problem

With regard to the building management organization, the GZhI conducted an unscheduled inspection of compliance with license requirements. During the inspection, it was found that exhaust ventilation does not work in the bathrooms of several apartments.

As a result, the GZhI drew up acts and issued instructions to the managing organization to eliminate violations - to restore the natural exhaust ventilation system in the bathrooms of the apartments. At the same time, a condition was set - to comply with the requirements of clause 4.7 of SanPin 2.1.2.2645-10.

The managing organization considered that there was no ventilation in the disputed premises and they wanted to entrust the construction of a new one to it. The construction of new ventilation refers to the overhaul works, and for them the decision of the general meeting of the owners of the premises in the MKD is needed. Therefore, the managing organization applied to the court for the prescriptions to be declared invalid.

Different approach of the courts to the solution of the issue

The court of first instance upheld the managing organization and recognized the work on the restoration of the exhaust ventilation system as being a major repair work. The court confirmed that they are carried out by the decision of the owners of the premises in the MKD.

The appeal overturned the decision of the trial court, citing

Regulation on licensing business activities for the management of MKD, approved by Decree of the Government of the Russian Federation of October 28, 2014 No. 1110;
Rules for the maintenance of common property in MKD, approved by Decree of the Government of the Russian Federation of August 13, 2006 No. 491;
Rules approved by the Decree of the Gosstroy of the Russian Federation of September 27, 2003 No. 170;

The decision of the Court of Appeal was upheld by the Supreme Court of the Russian Federation. The instructions of the GZhI were recognized as legal, and now the managing organization will have to restore the exhaust ventilation system. Why, read on.

Restoration of the ventilation system refers to the current repair

The Court of Appeal and the Supreme Court of the Russian Federation refused to satisfy the complaint to the managing organization and nevertheless obliged it to comply with the instructions for certain reasons.

The MA considered that she would have to make the ventilation system from scratch. On the house itself, the ventilation system in the house was, just out of order. Restoration of ventilation performance refers to current repairs, there was no talk of a major overhaul.

The managing organization must carry out the current repairs, because under the terms of the management agreement concluded between it and the owners of the MKD, the MA assumed obligations for the proper maintenance of the common property.

The courts noted that the managing organization is obliged to maintain the common property in the MKD in proper condition, regardless of whether or not the owners decided to carry out certain repairs and whether this is recorded in the text of the management agreement.

Therefore, the remark of the managing organization that it does not have the decision of the owners to carry out repair work, the courts did not take into account. The case concerned urgent, ongoing work aimed at fulfilling the mandatory requirements for ensuring the standard level of maintenance of the common property of MKD.

Considering all of the above, the courts did not satisfy the complaint of the managing organization.

Remember

The restoration of the ventilation ducts in the MKD refers to the work on the current repair of an apartment building. It will be a major overhaul if we are talking about building a ventilation duct from scratch.

The obligation to maintain the housing stock in a habitable condition does not depend on the adoption or non-acceptance by the owners of the property in the MKD of the decision to carry out repair work and fix them in the text of the contract.

If such a decision is not made, this is not considered an obstacle to the implementation of ongoing work aimed at maintaining the established level of maintenance of the common property of the MKD. The managing organization performs such work regardless of the decision of the general meeting.

Issue Status
The use in the mass construction of residential buildings of translucent structures with high tightness of window porches (in PVC, glued wood, aluminum, etc., with two or three sealing circuits, sealing of double-glazed windows) has led to a number of problems associated with the deterioration of indoor air quality, an increase in its relative humidity, mold formation on individual structures, damage to interior decoration, etc., which has been repeatedly written on the pages of various specialized publications.
It should be noted that these problems are not unique to our country. There was even a special term that characterizes the state of the parameters of the internal environment of such buildings - "the syndrome of sick buildings." But if in most European countries the increase in the tightness of window blocks and, accordingly, the decrease in air exchange in rooms was considered, first of all, from the standpoint of energy saving (reduction of energy costs for heating supply air) and various types of valves, supply and exhaust systems were provided as compensatory measures for air supply. mechanical ventilation, then in our country the transition to the use of sealed translucent structures took place (and is taking place) with a slightly different motivation (convenient, beautiful, “no noise”, etc.) and practically without any regard for the relationship with the microclimate of the premises and work ventilation systems. And often without an elementary understanding of this relationship.
In recent years, one more problem has been added to the above - a violation of the operation of natural ventilation systems, which manifests itself in a change in the direction of air movement in the exhaust ventilation ducts (the so-called overturning of the ducts) with the entry of outside cold air into the heated premises. Consequences: lowering the temperature of the walls of the channels, the formation of condensate, frost, frost, up to the defrosting of cold water pipelines. That causes quite natural claims to builders from consumers.
It should be noted that other violations of the ventilation systems are possible, in particular, air flowing through the exhaust ducts between individual apartments, air flow from the warm attic to the apartments on the upper floors, overturning of the exhaust shafts and, accordingly, lowering the air temperature in the warm attic, etc. However, in this article, it is precisely the cases of overturning of natural ventilation systems with vertical channels (without a warm attic) that are considered in this article - with the entry into apartments through one of the exhaust ducts of outside cold air.
Physics of processes
The reasons and conditions for the overturning of individual channels can be considered using the example of an apartment on the top floor of a multi-storey residential building with independent ventilation ducts located in the bathroom and kitchen.
Under the influence of thermal pressure drops, the exhaust ducts remove air from the apartment, creating a certain vacuum, as a result of which fresh air must enter the living quarters through leaks in the building envelope or open vents. And if the sashes of the window blocks are open in at least one of the rooms, then the air flow is provided and the exhaust ducts work for the hood - as envisaged by the project. But if the sashes of the window blocks are closed, while the window blocks themselves are made with good sealing of the porches, then the air flow into the apartment decreases sharply, the air flow through the exhaust ducts decreases accordingly, and the system as a whole enters an unstable equilibrium mode: there is a pressure difference, the channels are filled warm air, but there is practically no air movement through the channels - due to insufficient inflow. The system "stops".
And in this situation, a small pressure difference due to gusts of wind, opening of the front door, temperature difference in individual rooms or different marks of the ventilation shaft heads is enough for one of the channels to “tip over”. At the same time, the "tipped" channel is filled with cold air, its walls are cooled, an additional pressure drop appears due to the difference in the densities of warm and cold air in different channels of one apartment, and the system goes into a new stable state with the flow of outside air into the apartment through the exhaust channel.
It should be noted that attempts to start overturned channels by heating them with gas burners, connecting fans, increasing the height of the heads, as a rule, do not give an effect, since the causes of overturning are not eliminated.
If the channels are located in different parts of the apartment (for example, the bathroom is in the bedroom area, and the kitchen is adjacent to the hallway), then cold air moves along the corridor from one of the channels to the others. As a rule, one channel “overturns” in the apartment, while other exhaust channels begin to work hard for the hood.
When you open a sash of a window block (any - in the kitchen or in the common room), the ventilation system of the apartment switches to the design mode - with the removal of air through all exhaust ducts. But when the sash is closed, everything returns to its previous state.
Aerodynamic calculations of ventilation using a special computer program show that when the characteristics of modern windows are introduced into the calculation, a violation of the ventilation system occurs at almost any outside temperature. At the same time, when the characteristics of the “old” window blocks are introduced into the calculation (without sealing the window porches), the exhaust ducts work for the hood even with the windows closed.
In multi-storey buildings with vertical prefabricated channels and satellite channels, the pressure distribution along the height is more complex. The characteristics of the entrance doors, the staircase, the dimensions of the prefabricated channel and satellite channels, not to mention the wind or the open sashes of window blocks on individual floors, have an influence. However, in general, the described relationship remains true for multi-storey buildings. In practice, there have been cases of overturning of the prefabricated channel completely throughout the riser - from the top floor to the basement of a ten-story residential building.
What to do?
The traditional questions that arise in such situations are “who is to blame” and “what to do”?
As a rule, claims for “incorrect” operation of ventilation systems are presented to builders: “... deviations from the project”, “... quality of work performance”, etc. But, despite the fact that in some cases certain costs of implementing design solutions take place on construction site, the main reasons lie deeper and are caused, first of all, by omissions or mistakes made at the design development stage - when choosing a schematic diagram of a ventilation system, conducting an aerodynamic calculation and substantiating the design parameters of the system. Although it should be noted that it is difficult to call these omissions fully errors, since until recently there were no regulatory and methodological documents prescribing the procedures for such calculations in relation to natural ventilation systems, taking into account the characteristics of modern enclosing structures.
In this regard, an excerpt from SNiP 31-01-2003“Residential multi-apartment buildings” “... In residential premises and kitchens, air flow is provided through adjustable window sashes, transoms, vents, valves or other devices, including autonomous wall air dampers with adjustable opening ...”. That is, formally, SNiP 31-01-2003 allows ventilation due to periodically opening vents or casements of window blocks, which is what designers refer to in critical situations.
But the same SNiP also stipulates the requirements for air exchange of premises - in non-working mode, the air exchange rate must be at least n=0.2 for living rooms and not less n=0.5 for kitchens and bathrooms. That is, even in the absence of people in the apartment, the ventilation system must provide a certain air exchange. For example, in a typical three-room apartment - at least 40 m3 / h. How to ensure this air exchange is the task of designers. With closed sashes, window blocks made of PVC profiles or glued wood do not provide even 20% of the required air flow.
The question “what to do” can be conditionally divided into several private sub-questions:
what to do when designing natural ventilation systems in order to exclude such results at the design development stage (it should be noted that this is the most difficult issue that requires separate consideration);

what to do during construction (how to make sure if a building with a similar ventilation system is already under construction);

what to do if the building is built and the phenomena described are fully manifested already at the stage of operation.

At first glance, the obvious and simple answer to all these questions is to ensure an organized air flow by installing supply valves. Since window blocks have learned to be made so airtight, it is necessary to make additional, adjustable “windows” - “autonomous valves” for an organized air flow, and, accordingly, depressurize the apartments. It should be noted that at present this kind of supply valves are quite widely represented on the domestic market, certain experience has been gained in their operation and there is already plenty to choose from.
However, only the installation of supply valves does not guarantee the stable operation of the natural ventilation system. Supply valves are a necessary but not sufficient condition.
The reasons are as follows:
firstly, during the operation of the building, no one can guarantee that in individual apartments (and maybe in all apartments, for example, at the stage of completion of construction or the initial stage of operation of the house) the valves can be closed; and, accordingly, the ventilation system may again be in an unstable state; secondly, there is too much difference in the aerodynamic resistance of the supply valves (even when fully open) and the exhaust ducts.

As an example, in Table. 2 shows the resistance characteristics of some supply valves, window blocks and exhaust ventilation ducts. The differences in the resistance characteristics are several orders of magnitude.
In other words, in a modern apartment equipped with supply valves, such as window valves or wall valves, the main pressure losses (air resistance) do not occur in the exhaust ducts, as is assumed in traditional calculations, but in the inlet (supply valves and windows). And, accordingly, for the successful operation of the ventilation system, careful coordination of the exhaust ducts is necessary, both with the supply ventilation devices and with each other. The word "linkage" in this case means the selection of the characteristics of the supply valves (quantity, resistance for air passage, flow rate) and the characteristics of the exhaust ducts (number, dimensions, height of the heads, etc.); if necessary, increase the resistance of the channels by installing louvered grilles, exhaust valves or throttling liners.
This task is especially relevant for apartments on the upper floors of multi-storey buildings, as a rule, having their own exhaust ducts (with very little resistance), as well as in cases where the heads of the ventilation shafts are at different elevations and the operation of the ventilation systems is also affected by the difference in available pressures. in exhaust ducts of different heights.
Thus, in order to ensure stable operation of natural ventilation systems in residential multi-apartment buildings and to prevent tipping of exhaust ducts, it seems necessary:
1. Mandatory use of supply devices that provide a regulated supply of fresh air to living rooms.
2. At the stage of designing ventilation systems - careful coordination of exhaust ducts with supply ventilation devices and among themselves. If it is not possible to provide the required cross-section of exhaust ducts (for example, in large-panel buildings with factory-made ventilation units), provision should be made for the installation of throttling inserts with calibrated holes, indicating their number, installation location, diameter of holes with layout by floors (as was done during the design heating systems with throttling washers on risers).
Ideally, projects of residential buildings should provide for the installation of special exhaust valves on the ventilation ducts, which provide the ability to automatically control the air flow depending on the mode of operation of the apartment, including with the functions of a check valve. The resistance of the exhaust dampers should be changed taking into account the mode of operation of the supply devices or the degree of opening of the window sashes. The principal characteristics of such devices are shown in fig. 4.
3. When putting a residential building into operation - commissioning adjustment of exhaust ducts and supply devices. The performance of ventilation systems should be assessed both with open and closed sashes of window blocks. In accordance with the requirements of SNiP 31-01-2003, the ventilation system must provide on-duty air exchange even with the windows closed.
If the appropriate solutions were not provided at the construction stage and the overturning of air in the channels was already detected during the operation of the building, the following sequence of actions can be recommended:
to bring the system into the design mode - cover (or completely close) the exhaust channels working for the hood; at first glance, this advice may seem strange, since in order to reduce the influx of cold air, it seems to be necessary to block the channels that work for the inflow (which is what residents try to do in such situations); however, only by blocking the channels working for the exhaust, it is possible to “force” the overturned channels to start working in the design mode; to speed up this process, you can slightly open one of the sashes of window blocks;

install (mount) in each living room, with the exception of the kitchen and bathrooms, window or wall valves with adjustable air flow;

further - install throttling inserts with holes with a diameter of 40-50 mm in all channels of the apartment, thus increasing the resistance of the exhaust channels; as throttling liners, you can use any sheet material - expanded polystyrene, drywall, polyurethane, which can be easily inserted into the exhaust ducts;

after the system enters the design mode, it is possible to replace the throttling inserts in the ventilation ducts with louvered grilles with an adjustable cross section; choose the mode of opening the dampers of the supply valves and louvres, providing the required air exchange of the apartment.

The difficulty of implementing the above recommendations is partly due to the fact that in ventilation systems with vertical prefabricated channels, the above measures must be carried out in almost all apartments located on one riser (at least in at least 60% of apartments). Otherwise, it is possible for air to flow through the collection duct to the apartments of other floors.
In emergency situations, for example, in case of malfunction of ventilation systems during a sharp cold snap, a simpler solution is also possible - by reducing the cross section of the channels ("clamping" all channels) at the mouth of the exhaust ventilation shafts - from the roof side. However, this solution significantly reduces the air exchange of all apartments and can only be considered as a short-term measure aimed at preventing damage.
It should be noted that the above problems are typical, first of all, for ventilation systems with vertical channels that go directly into the atmosphere - without a warm attic. Ventilation systems with a warm attic are more resistant to tipping - due to the presence of a common chamber - an attic space that equalizes the pressure between the individual channels of the apartments. However, these ventilation systems must also take into account the above recommendations.

The composition of the air and the health of the inhabitants living there will depend on how the ventilation device is made in multi-storey buildings.

Many people want to make their living more comfortable and cozy. But the opposite is happening. Without thinking about the consequences or out of ignorance, they disrupt the air exchange, which leads to negative consequences. The purpose of this article is to explain how the ventilation system in an apartment building functions, what factors disrupt its operation and what problems this leads to.

Selection criteria, types and elements of ventilation in an apartment building

The presence of certain elements will directly depend only on the type of system. But, regardless of the option chosen, it will contain the following mandatory components:

air channels;
ventilation shaft;

Regardless of the type, it will be necessarily a supply and exhaust. Accordingly, it is necessary to ensure not only the hood, but also the arrival in the same volume.

Depending on the type of thrust initiation, such systems are usually divided into:

natural - draft appears due to the difference in temperature and pressure in the street and in the room;
combined - exhaust or injection is carried out electromechanically;
forced - draft and injection occurs with the help of special fans and other devices.

If natural ventilation of residential buildings is used in a multi-storey building, the presence of a ventilation shaft is mandatory.

Scheme of a typical house ventilation shaft

The requirements for its arrangement are simple and the same for all buildings:

tightness;
throughput corresponds to the design volume;
compliance with sanitary and hygienic standards;
fire safety.

Also, depending on the air exchange scheme, the system can be with mixing or displacement. The first method is typical for impenetrable walls with vapor barrier. The inflow goes through the ventilation holes and various slots. Due to the relatively high initial speed, outdoor fresh air is mixed with polluted air. With improper organization of flows, it will be difficult to extract air polluted with impurities in this way.

To select the type of ventilation, all factors must be taken into account, such as:

number of floors;
location relative to other structures;
the level of external noise;
environmental pollution.

For houses with an intra-quarter location and noise up to 51 dBA, it is recommended to install natural ventilation. If the building is located in a particularly polluted area, or the noise level is more than 51 dBA, it is necessary to use an air supply system and it is desirable to carry out filtration.

Arrangement of ventilation elements in a high-rise building

The location of the air intake from the street is equipped in certain places, depending on how the ventilation is arranged in an apartment building. If the heating of the intake air is not provided for in the system under consideration, it must be brought as close as possible to the ceiling of the room. This will ensure that it is fully mixed with the warmer air in the room.

In order for the penetrating air to be heated under the influence of heating devices installed in the apartment, the input is carried out near these devices.

When heating takes place directly in the blowers, the supply is equipped at the bottom of the room.

Despite the type of system, the inflow occurs only in the living rooms, and the exhaust hood in the kitchen and bathroom. The hole for the hood is equipped at a height of at least 2 meters from the floor. The ventilation scheme in a multi-storey building assumes the absence of air movement from sanitary and additional premises to living rooms.

Ventilation ducts of different rooms with natural exhaust of polluted air are recommended to be provided separate, excluding single-level assemblies. If this is not possible in an apartment building, it is necessary to provide for the supply of individual pipes to one vertical shaft.

They join such a shaft mainly once every two floors. Ventilation on the top floor is output separately, it is not recommended to connect it to the shaft.

Features of arrangement and functioning in panel houses

If we talk about such a common type of houses, then there the air exchange is arranged according to a natural principle. The system works in the same way in old brick houses, as well as in low-budget new buildings. Outdoor air is sucked in through cracks and leaks in old frames or through special holes provided in modern plastic ones.

Removal in them occurs due to the presence of a constant draft present inside the ventilation shaft-duct, which rises above the roof ridge or goes into the attic. Outdoor air, getting into the living quarters through the windows, due to the draft in the channel, tends to the exhaust outlet in the bathroom or the hood in the kitchen. It turns out that the air, passing through all the premises of the apartment, gradually displaces the polluted into the street.

The order of operation of ventilation on the example of a typical project

The most common panel project is a nine-story building. The principle of operation of the hood is the same for them. Air from the street, through windows and cracks, enters the apartment. Extraction occurs through satellite ventilation ducts in the kitchen or bathroom. One, less often several channels from the hood are brought to the main pipe. These channels are connected to the main shaft through two floors. These shafts are quite bulky and take up a lot of space. Such a system, most likely, will be equipped with a large-panel house.

Such a scheme for a house of 9 floors suggests the presence of a warm attic. The outlet from the 8th and 9th floors goes directly into the atmosphere, bypassing the common channel. The scheme for a 9-storey building was designed based on the complete absence of wind and the outside air temperature of +5.

Despite the fact that natural ventilation in such houses is not very efficient, it requires almost no maintenance, blockages rarely occur. There were cases when the ventilation ducts were clogged with building materials during the construction of the house. Such a surprise later affected the quality of the hood. Most often, cleaning the mine is required once every 5-6 years.

During repairs, many people block the air flow in some place. They unknowingly think that this will not affect the hood, but the process of air renewal in the apartment is hindered or stops completely.

The most common actions that lead to interference and malfunctions in natural ventilation are:

installation of sealed plastic windows;
interior doors with seal;
installation of various fans in the hood.

In order not to disrupt the operation of the natural ventilation draft, it is forbidden to obstruct the inflow and outflow of air. For plastic windows, it is necessary to install air inlets or arrange an external inflow separately. Doors between rooms are equipped with bars at the bottom. The cross section of the exhaust duct must not be blocked by fans.

Possible options for arranging ventilation in high-rise buildings

Modern ventilation in a panel house is equipped with single exhaust pipes. From the bathrooms, from each floor to the roof there is a pipe. In this embodiment, there is no possibility of penetration of foreign odors and the entire system functions evenly and reliably.

Another good option is when all vertical channels go to a common horizontal prefabricated manifold, which is located in the attic. The air from it goes outside through one common pipe.

The most unstable way can be called the option when a small satellite channel from each apartment is included in a common ventilation shaft. Such a ventilation scheme in a panel house is much cheaper in arrangement and increases the living space, but constantly brings a lot of problems to residents. The most common is the flow of various odors from one apartment to another.

The best option for ventilation are electromechanical forced air supply and exhaust systems. They are used in modern new buildings, except for low-budget ones. The supply unit of such a system is located in the basement or on the side of the main building. It supplies filtered and heated or cooled air to all rooms and premises. On the roof, in turn, an exhaust electric fan is installed with exactly the same rated power as the supply one. It is designed to remove the contaminated mixture from the apartments through the hoods.

This is one of the primitive schemes of the device. A more complex one, which can be equipped with a modern high-rise building, is being equipped using new energy-saving technologies. For example, recuperators are devices that allow you to take heat or cold from the exhaust air and give it to the supply air.

The consequence of the installation of modern sealed windows and doors is the unsatisfactory operation of the ventilation elements and its non-compliance with the recommendations of SNiP. Few people are ready at any time of the year to keep the windows ajar for the influx of the required amount of air, even in cold weather. In the absence of effective operation of the hood, the humidity index increases, the air saturation with carbon dioxide increases, and oxygen decreases. In such a microclimate of the room, when the air humidity is above normal, mold and various fungi multiply perfectly. It is very harmful to the human body and not aesthetically pleasing in appearance.

The way out of the situation is quite simple. It is necessary to acquire. It will eliminate the problems of air renewal, and the use of a recuperation system allows you to maintain a comfortable microclimate and fresh air with minimal energy consumption.

According to sanitation standards, each residential building must have a ventilation system, the purpose of which is to remove dirty, “exhaust” air from non-residential premises (toilet, bathroom, kitchen). From improper ventilation, windows sweat, dampness and mold appear on the walls. With its proper functioning, such unpleasant phenomena should not be. The consequences of malfunctioning ventilation can be very deplorable: if you have a growing baby, he may develop asthma or other dangerous diseases.

To measure the efficiency of the ventilation system, take a medium sheet of paper (10x10 cm), open a window in the room and hold the piece of paper to the ventilation grate. If there is a swaying leaf, everything is fine. Otherwise, there is a malfunction.

Purpose

The purpose of the ventilation system in a multi-storey building is to exchange atmospheric masses with the removal of excess moisture, dust, generated heat and harmful substances from the premises to create a favorable microclimate in the rooms and purify the air. In panel, brick, as well as modern low-budget residential buildings, a natural-type ventilation system is used.

System design in multi-storey buildings

There are 2 types ventilation systems in multi-apartment buildings:

natural;
forced.

The natural ventilation system is different in that the exchange of air in the apartments is due to temperature and pressure changes. The principle of operation is that polluted air exits through ventilation ducts and shafts to the street. And the clean one gets inside through the vents, doors, windows on the outer wall, sometimes this requires the installation of special supply valves.

It is possible to lay separate ventilation shafts for each of the apartments located in the house, but this option is cost-effective only for low-rise buildings. In high-rise buildings, such a design is unrealistic. In the construction of multi-storey residential and non-residential buildings, two common schemes are used.

The exits of all shafts are arranged in the attic, and a common horizontal channel is mounted there. This channel has one exit laid in the most convenient place.
From individual apartments, polluted air is discharged through horizontal channels into common (for entrances) vertical shafts (risers), which deliver it through the roof to the street.

Differences are visible from the description. The second type is characterized by the idea of a private straight shaft for the upper floors, since a horizontal channel height of at least 2 m is required for the formation of thrust.

All ventilation ducts and shafts must have high-quality thermal insulation, otherwise the formation of condensate in the attic is inevitable, followed by mold and inappropriate destruction of materials.

The horizontal box in the attic has its own requirements: its cross section must be of sufficient size so that no back draft is formed.

The houses of the old building plan are equipped with a natural ventilation system. It has a significant advantage - it does not require electrical power. But there are also disadvantages - its effectiveness depends on the cleanliness and absence of obstacles in the mines and canals.

More and more often, instead of wooden frames, plastic and metal-plastic windows are being installed everywhere. Their undoubted advantages - tightness and sound insulation - for ventilation systems work in the negative, since the natural ventilation system provides for the removal of air through cracks in windows and vents. In such situations, a second type is constructed - a forced ventilation system.

It is characterized by the use of various devices for the artificial creation of air flows. It is mounted in cases of lack of natural ventilation or adverse environmental conditions.

The disadvantage of the forced system is its high cost, which is the cost of additional equipment, consumed electricity and required maintenance. Pluses - high efficiency of air mass exchange, the possibility of heating or cooling air, cleaning it from dust, and so on. Typically, its design includes a fan in the basement and an exhaust unit on the roof of the house.

They also use recuperators - energy-saving equipment. Their job is to transfer heat (cold) from the exhaust air to fresh air.

Mechanical ventilation systems are divided into 3 types:

supply;
exhaust;
mixed.

The first type is characterized by an artificial influx of clean air, and the waste is removed through windows and doors (in a natural way). This system consists of a supply system, heater, cooler, filters. The power of these systems varies widely, depending on it they are divided into household, semi-industrial and industrial. According to the type of construction, supply systems can be monoblock and type-setting. Each type has its pros and cons.

Monoblock systems are mounted in soundproofed compartments, which makes them less noisy and more suitable for residential installations. Type-setting structures consist of individual elements, and can serve various objects - trading floors, offices, apartments. But for their installation, an accurate calculation is required, in addition, they are large in size.

For the exhaust system, the situation is reversed: the inflow of fresh air is carried out naturally, and the emission of polluted air is carried out mechanically. This requires the installation of an exhaust system.

With a mixed ventilation system, both inflow and outflow are produced by electrical appliances. It is considered the most effective design, as it combines the advantages of the two previous types. Supply and exhaust systems provide, in addition to air exchange, also air purification, maintaining the required temperature and moisture content. The efficiency of the system is not affected by weather conditions or seasons of the year. The main thing is to design a balanced system, where the inflow of clean air is balanced by the outflow of exhaust air.

The advantage of mixed ventilation is efficiency, which is ensured by heating fresh air and heat recovery from the outgoing polluted flow. For meteorologically sensitive people and hypertensive patients, an important advantage is the ability of the system to regulate the level of atmospheric pressure in the room.

When choosing a ventilation system, the following factors are taken into account:

height and number of floors of the building;
the location of the building;
environmental noise level;
degree of outdoor air pollution.

Basement ventilation is one of the factors that ensure the correct operation of the entire ventilation system. For the natural circulation of air masses in the basement, special holes are made in its walls. This achieves not only a decrease in humidity at the bottom of the house, but also the creation of traction in the mines.

Sewer ventilation is an important component of the fresh air supply system. There are several design solutions for sewer ventilation.

A straight line, in which the sewer risers on the upper floor are brought up, and do not remain closed. Clean air flows through the tops of the risers, preventing suction in the siphons along the way.
Parallel, when the ventilation riser is constructed parallel to the sewer, they are connected to each other by bends along their entire length. It is considered more effective than the first type.
In the case of buildings with 9 or more floors, the best option is a system using mixers.

What to do with reverse draft in apartments?

The effect of "reverse draft" is that the air in the apartment is not cleaned, but, on the contrary, is clogged with polluted from the street or from neighbors.

There may be several reasons for this situation.

The outlet pipe of the ventilation system, located on the roof, is incorrectly oriented relative to the air flows, which prevents their circulation.
Accumulation of steam or chilled air in ventilation ducts.
Mechanical barriers - debris, soot, snow or ice plugs, sometimes bird nests.
In large rooms, the formation of own currents and drafts is possible, which causes a risk of disturbing the exhaust of polluted air.
The operation of fans, air conditioners, split systems, even kitchen hoods interferes with natural ventilation.

Responsible specialists are required to diagnose the system to determine the causes of reverse thrust.

First of all, they study the technical documentation. On the basis of this study, the results of the literacy of the development of the design according to the accepted standards are summed up, then the operating conditions of the system are checked.
It is necessary to check the correctness of the laying of ventilation ducts and their compliance with sanitary and technical standards.
They inspect the ventilation system for clogging, patency, operability of the channels, eliminate the breakdowns found.
Then the specialists proceed to inspect the system for overlapping ventilation channels. The volumes of passing air are calculated to compare them with the design values.

The appearance of reverse thrust may be due to a drop in atmospheric pressure or a change in the wind vector. In such cases, open windows will help. If the cause of the poor performance of the ventilation system is not identified, a deflector is mounted.

It is necessary to regularly clean the ventilation shafts, this must be done because of their frequent clogging. If drafts in the apartment became the cause of the reverse thrust, it is advised to re-plan the premises, install tight doors.

What regulatory documents are needed for verification?

Ventilation systems must meet all the requirements established in accordance with SNiP 41-01-2003. "Heating, ventilation and air conditioning" and SNiP 2.04.05-91 "Heating, ventilation and air conditioning". When checking the operation of the ventilation system, the design documentation of the house is also needed, indicating all the elements of the ventilation system - it is examined for compliance with the above standards.

Survey frequency

Diagnostics of the state of chimneys and ventilation ducts performed in the following situations:

commissioning of an apartment building before gasification and heating connection;
redevelopment of apartments or repair of ventilation ducts;
prevention, it should be carried out every quarter and 7 days before and after the drinking season;
identification of poor traction or its absence;
in all cases related to gas equipment, when called through the emergency dispatch service.

A study of the suitability for use of chimneys, according to the standards, must be carried out:

for those built of brick - quarterly;
for those constructed from asbestos cement, clay, heat-resistant concrete - annually;
heating and cooking stoves - in spring, before and during the heating season;
heating boilers and furnaces - annually.

For ventilation ducts and rooms with gas installations and appliances, the frequency of such a check is set at least twice a year.

Who is responsible?

Management companies are responsible for the normal operation and condition of the ventilation of an apartment building. Maintenance of housing and communal services (this includes ventilation systems) is part of their responsibilities.

Operational problems and their elimination

Often in old buildings equipped with a natural ventilation system, a situation arises when the vector of movement of air masses changes in the exhaust ducts (overturning). As a result, cold outdoor air blows into warm apartments, the walls of the channels cool, condensation appears, frost, then icing is possible.

The reason is the imbalance between the inflow of fresh air and the exhaust of exhaust air due to the incorrect design of the ventilation system, redevelopment of the premises or the installation of sealed window frames. Installing inlet valves is not sufficient to solve this problem. But it is possible to eliminate it.

In accordance with existing standards, any residential premises must be equipped without fail, which is designed to eliminate polluted air from non-residential rooms (toilet, bathroom, kitchen). In the event of a malfunction, the glass on the windows begins to fog up, condensate flows down the walls, the corners become damp, and mold forms in the rooms; if the ventilation system is working properly, such troubles are invisible. If there is a small child in the house, then the consequences of poor-quality air exchange can cause the baby to develop bronchial asthma or other respiratory diseases.

Diagram of a forced ventilation device in a multi-storey building

To check the performance of the ventilation system, you need to take a small piece of soft paper (about 10x10 cm), open a window in the room, and then bring a piece of paper to the ventilation grill. In the event that the leaf sways, the ventilation works well. In turn, if the sheet is not attracted, this is an indicator of poor-quality operation of the ventilation system.

Ventilation problems in apartment buildings, especially on the upper floors, are quite common. The reason for the problems lies in the fact that in order to ensure normal circulation in the apartment, the air must pass through the ventilation duct at least 2 meters vertically. On the top floor, this condition is problematic, since the attic space acts as an obstacle. You can bring ventilation to the street using three different methods.

The first - ventilation ducts, in the form of a pipe head, directly go to the roof. Houses were built in this way until the beginning of the 20th century, but the increased number of storeys of buildings gradually pushed this method aside.
In the second method, ventilation, upon reaching the attic, was covered with horizontal sealed boxes connected to a shaft that went out over the roof.
With the third method, the most modern, ventilation first enters the attic, which plays the role of an intermediate ventilation chamber. After that, the air enters the outside, passing through one common ventilation shaft.

We will not consider the first option, since it is not currently used - we will focus on the second and third methods.

In the second option, the following happens: air from all floors rises up through the channels, to the level of the attic, falling into a horizontal connected box, equipped in the attic room. During this, the air flow hits the cover of the horizontal ventilation duct. The air flow is slightly deviated towards the ventilation shaft, but if the internal section of the horizontal attic box is insufficient, an area of increased pressure appears in the box, due to which the air seeks an outlet through any nearby opening, for example, a ventilation shaft and an upper floor channel.

In the event that the section of the box is sufficient, but the cover is mounted very low, then the same process occurs - reverse thrust - the air flow does not have time to deviate towards the ventilation shaft, which entails a blow. The ventilation of the upper floor is “pressed through” by the reflected air flow, which is why odors from the lower floors fall into this particular room. To get rid of this, you can resort to two methods - global and local.

The global method involves an increase in the cross section of the attic horizontal junction box by changing its height by about 2-3 times, followed by the installation of some devices inside the box, called "cuts". Keep in mind that all these works must be carried out by experienced professionals. In addition, remember that it is not recommended to increase the section of the box in cases where exactly the same boxes are attached to the ventilation shaft from the back.

Natural supply and exhaust ventilation of a residential building

High-quality work of supply and exhaust ventilation is able to fully provide a microclimate suitable for a person in the room. If unpleasant odors regularly appear in the room, and the windows fog up, this is a good reason to check the ventilation work. If the test showed poor system performance, then it is likely that the ventilation shaft is clogged.

Scheme of the device of natural supply and exhaust ventilation in an apartment building

How to make the ventilation work in the apartment with your own hands

How to clean the ventilation in the apartment

If you decide to clean the ventilation, then keep in mind that residents of apartment buildings do not have the right to independently install utilities used by other people. Cleaning or repair of the ventilation shaft must be carried out only by specialists from the relevant organizations. If the ventilation and air conditioning of your home is not working, the only thing you can do is to remove the grate from the vent and remove the debris in it with a vacuum cleaner (or by hand).

In some cases, it happens that the exhaust system is in good condition, but unpleasant odors and misted windows still make themselves felt. This can often be observed in apartments where plastic windows are installed. In this case, there are two ways to solve the problem: regular ventilation of the rooms or installation of additional supply valves.

Drawing and installation diagram of the ventilation valve on the window

Supply valves are usually installed in openings behind radiators, which allows fresh air to warm up a little when it enters the room. The diameter of the holes is usually in the range of 6-10 cm. According to the types of construction, valves are divided into several types. Some, for example, have a plug that can be opened manually if necessary. More modern models are equipped with special sensors that can respond to changes in the level of humidity in the room, at the right time opening a valve that lets in fresh outdoor air. Many valves have a set of filter elements.

In most cases, natural ventilation in old houses is not able to provide the necessary amount of fresh air, so many people install air conditioners. This device cannot completely replace the ventilation system, but it can purify and humidify the air in the apartment.

Forced ventilation in a panel house

Forced ventilation comes to the rescue in cases where natural ventilation is not able to cope with the tasks assigned to it. It is impossible to completely install it on your own, since in each case its project has its own characteristics. In the event that you need to install ventilation in a one-room apartment, you can purchase a simple monoblock device.

For the highest quality ventilation of each room, it will be necessary to install air ducts, the installation of which can be carried out by any person. Typically, air ducts are installed under a false ceiling or built into walls.