In pursuit of comfortable conditions inside offices and residential premises, one cannot do without properly organized air exchange. In other words, inside them there must be a correctly calculated, adjustable system ventilation. For indoors for various purposes are guided by the relevant regulatory literature, but first let’s look at what constitutes air exchange.

Air exchange concept

Air exchange is a quantitative parameter characterizing the operation of the ventilation system in enclosed spaces. In other words, air is exchanged to remove excess heat, moisture, harmful and other substances in order to ensure an acceptable microclimate and air quality in the serviced room or work area. Proper organization air exchange is one of the main goals when developing a ventilation project. The intensity of air exchange is measured by the multiplicity - the ratio of the volume of supplied or removed air in 1 hour to the volume of the room. The ratio of supply or exhaust air is determined by regulatory literature. Now let's talk a little about SNiPs, SPs and GOSTs, which dictate to us the necessary parameters to maintain comfortable conditions in office and residential premises.

Air exchange rates

Currently, a lot of literature has been published; let’s look at just a small part:

Modern buildings have high thermal characteristics, airtight plastic windows to save space heating costs, which inevitably leads to the tightness of the room itself and the lack of natural ventilation. And this, in turn, leads to air stagnation and the proliferation of pathogenic microbes, which is not allowed by sanitary and hygienic standards, and even preserve wellness It’s unlikely to succeed in a stuffy room. Therefore, in modern residential buildings must be provided supply valves in external enclosures with natural impulse, and in office premises one cannot do without a supply and exhaust mechanical ventilation device. All this is necessary to create comfortable conditions for people to stay in these premises.

Living spaces

The ventilation system for residential premises can be: with natural air inflow and removal; with mechanical stimulation of air inflow and removal, including combined with air heating; combined with natural inflow and removal of air with partial use of mechanical stimulation. In living rooms, air flow is provided through adjustable window sashes, transoms, vents, valves or other devices, including self-contained wall air valves with adjustable opening. Air removal is provided from kitchens, restrooms and bathrooms. The amount of air exchange in living rooms, according to more than 20 m².

Kitchen

Minimum air exchange rate in a kitchen equipped electric stove, according to 60 m³/hour, in the case of a gas stove, it will be 100 m³/hour. Air flow is ensured in the kitchen, just like in the living rooms. Since cooking produces steam, as well as volatile particles of oil or other fats, the air from the kitchen should be removed directly to the outside and not enter other rooms, including through the ventilation duct. In order for the natural draft to be sufficiently stable, the channel must be relatively high (at least 5 meters). Often, an exhaust hood is installed in the kitchen area above the stove, which helps to more effectively remove excess heat from the room. In order to prevent the flow of air into higher-lying apartments, an air seal is made (a vertical section of the air duct that changes the direction of air movement), usually in a building design.

Bathroom and laundry

The air in the bathroom and laundry room contains unpleasant odors, humidity and harmful emissions from household chemicals, therefore, like the air from the kitchen, it must be removed outside without the possibility of entering other rooms. An air seal is also installed in the exhaust ducts of these rooms. From the bathroom room, according to , the air exchange rate will be 25 m³/hour, and from the laundry room 90 m³/hour. Supply air enters these rooms by flow from living rooms through open door or through cracks in the doorway.

Office rooms

The amount of air exchange for offices and administrative buildings is much higher than for residential buildings. This is because the ventilation system must more effectively cope with the large volume of heat generated by numerous employees and office equipment. And a sufficient amount of fresh air has a positive effect on both people’s health and the work process as a whole.

For ordinary office premises 40 m³/hour per employee is accepted, if it is possible to periodically ventilate the room through window sashes, transoms, vents, or 60 m³/hour per employee, if this is not possible.

Modern office buildings It is impossible to imagine without an organized ventilation system, which must meet the following requirements:

• The ability to provide the required amount of fresh air.
• Filtration, heating or cooling, and, if necessary, humidifying the supply air to comfortable conditions before supplying it to the room.
• The device has both supply and exhaust ventilation from office premises.
• Installations must be low noise and comply with the requirements specified in.
• The location is convenient for servicing ventilation units.
• Automatic control and weather-dependent regulation.
• Economical consumption of heat and electricity.
• The need to be compact in size and, if possible, fit into a business interior.

A correctly calculated air exchange rate is vital inside enclosed spaces, as it allows you to remove exhaust air contaminated with various technical fumes and particles carbon dioxide emitted by humans, odors of consumer products and life activities, heat from equipment and products, as well as many other sources. If we take into account all these parameters, then thanks to the operation of supply and exhaust ventilation it is possible to maintain optimal performance indoor air, creating a comfortable microclimate.

How can it be implemented - multi-apartment or private? What do current building codes say about this? What air flow standards should you adhere to when designing yourself?

How to implement air exchange in a private house? Let's try to figure it out.

Regulatory Requirements

Let's start by studying the current regulatory documents. Current SNiPs for ventilation of residential buildings are 2.04.05-91 “Heating, ventilation and air conditioning” and 2.08.01-89 “Residential buildings”.

For the convenience of the reader, we will bring together the key requirements of the documents.

Temperature

For a living room, it is determined by the temperature of the coldest five-day period of the year.

• If its value is above -31C, it is necessary to maintain at least +18C in the rooms.
• When the temperature of the coldest five-day period is below -31C, the requirements are slightly higher: the rooms must be at least +20C.

For corner rooms with at least two common walls with the street, the norm is 2 degrees higher - +20 and +22C, respectively.

Useful: the variability of requirements is due to the fact that at low temperatures and increasing heat loss, the dew point (the point in the thickness of the enclosing structure where condensation of water vapor begins) shifts towards the inner surface. The indicated temperatures exclude freezing of the wall.

For bathrooms, the minimum temperature is +18C, for baths and showers - +24.

Air exchange

What are the standards for ventilation of residential premises (more precisely, the rate of air exchange in them)?

Additional requirements

• The ventilation scheme may provide for air exchange between separate rooms. Simply put, you can organize an exhaust hood in the kitchen, and air flow in the bedroom. Actually, the document specifies the recommendation: exhaust ventilation should be provided in kitchens, bathrooms, bathrooms, toilets and drying cabinets.

• The ventilation of the apartment must be connected to a common ventilation duct no lower than 2 meters from the ceiling level. The instructions are intended to minimize the likelihood of the rod overturning in windy weather.
• Using separate rooms in a residential building for public needs they are supplied own system ventilation not connected with the common house one.
• When the temperature of the coldest five-day period is below -40C for three-story and higher buildings, it is allowed to equip fresh ventilation with heating systems.
• Gas boilers and water heaters with combustion products discharged into general ventilation are allowed to be installed only in buildings no higher than five floors. Solid fuel boilers and water heaters can only be installed in one- and two-story buildings.
• It is recommended to supply supply air to rooms with constant occupancy. Which, in fact, again leads us to the already mentioned scheme: air flow through the living rooms and exhaust through the kitchen and bathroom.

How it works

So, we have studied the basic requirements for ventilation of residential premises. How is ventilation implemented in apartment buildings and private buildings?

Apartment buildings

Traditions

The traditional scheme for Russia and the entire post-Soviet space is natural ventilation, which uses the difference in density between warm and cold air for air exchange. Warm heat is displaced to the upper part of the room and from there into the ventilation duct; The influx of cold air in Soviet-built houses was ensured by ventilation vents and loosely fitted wooden frames.

It was equipped according to the already mentioned scheme: in bathrooms, toilets and kitchens. The rooms were ventilated with fresh air.

Since each apartment has its own vertical ventilation duct - a luxury that is not allowed in high-rise buildings, ventilation systems individual apartments began to be connected by vertical shafts.

The shafts were united by a horizontal channel leading to the roof and equipped with an umbrella to protect it from precipitation; The outlet for each apartment was supplied with a short vertical channel - a satellite, which prevented air exchange between apartments.

What are the advantages of such a scheme:

• Ease of construction and, as a result, minimal investment costs.
• Minimum operating costs. In essence, they come down to only rare cleaning of clogged ventilation ducts. The cause of clogging is soot from gas stoves and, less often, violations during construction work.

• Influx of fresh air into the room directly from the street, without the need for any intermediate treatment.

Of course, there were some drawbacks.

• On the upper floors, the pressure required to ensure ventilation is minimal. Hence the frequent cases of the notorious overturning of the thrust in windy weather.
• A long channel with rough walls (traditional materials for shafts and outlets to apartments are brick and concrete) provides high aerodynamic resistance, which reduces the efficiency of ventilation.
• Channels are often leaky: to connect their elements, a cement mortar, which tends to crumble. Air leakage further reduces traction.

Modernity

Recently, during the construction of new buildings, a scheme with a warm attic is increasingly being implemented. How does she look?

Horizontal canals connecting several mines are a thing of the past. Instead, the entire attic became a static pressure chamber.

Important: thanks to stabilization high temperature in the attic, one of the main problems of the upper floor is solved - a cold ceiling. As a result, heating requirements are reduced.

The shafts are combined with horizontal branches into a single block of industrial production. This minimizes the number of potentially leaky connections.

An attic outlet is installed in each section of the house. Its combination with the elevator engine room allows, without disturbing the architectural appearance of the house, to increase the outlet height to 2 meters from the roof level, thereby further increasing traction.

Umbrellas protecting mines from rain and snow are a thing of the past: they caused a slight drop in draft. Instead, a tray with drainage into the sewer is installed at the base of the shaft.

The shaft opening onto the roof acquired a square cross-section, which improved traction in windy weather, regardless of the wind direction.

Attic made from reinforced concrete slabs, began to be divided into sections.

This solves two problems:

1. Air flows from different entrances cannot mix. Their mixing under certain conditions could lead to the fact that the thrust in one channel would be enhanced at the expense of the other channel.
2. Current rules have been followed fire safety: A fireproof partition can prevent the spread of hot combustion products during a fire.

What is the result?

• The operation of ventilation as a whole has become more stable, independent of the strength and direction of the wind.
• The aerodynamic resistance of the satellite channel increased from 1 - 1.5 to 6 - 9 Pa, which made air exchange in apartments less dependent on the floor.

A caveat: on the two upper floors the thrust may still be insufficient, since there is simply nowhere to place satellite channels of the required height. The problem is completely solved by installing exhaust fans in apartments: in this scheme, their operation can no longer lead to exhaust air from one apartment entering another.

Forced exhaust

The main problem with any natural ventilation scheme is its dependence on wind force.

The solution to this problem is quite obvious:

1. The aerodynamic resistance of the shaft is artificially reduced (for example, by installing adjustable valves).
2. The shaft is equipped with a radial fan with a noise reduction system.

The price of increased efficiency is a slight increase in operating costs and investment cost of the project.

Foreign experience

A rather interesting ventilation scheme is implemented in apartment buildings German builders.

• Exhaust ventilation is organized through the kitchen and combined bathroom.
• The air intake is common channel, opening into the room with several small holes around its perimeter and a central valve equipped with a solenoid and a return spring. The air duct has increased aerodynamic resistance and a sound dampening chamber.

How it works:

• In standby mode, the hood is carried out to a limited extent.
• When you turn on the light in the bathroom or forcefully supply power to the kitchen valve, the air intake capacity increases sharply; in addition, forced ventilation is turned on.

Private housing construction

Scheme selection

The choice was made on exhaust ventilation with forced induction and natural air flow through the basement.

There were several motives.

• Exhaust ventilation involves laying one channel. Supply and exhaust - two, which means a much larger amount of work and damage to the repairs already made.

It is worth clarifying: in in this case there was already a channel for air exhaust. This role was played by the groove disguised by the builders between the crossbar on which the floor slabs rested and outer wall. It was only necessary to punch holes for the air intake and organize the exhaust to the street.

• Calculating the natural ventilation of residential buildings is extremely complex; For this, either complex formulas are used that take into account many variables, or online calculators, which often give unreliable results. For forced exhaust, the performance with a minimum error is equal to the performance of an exhaust fan.
• The air intake from the basement (dry and located below ground level) made it possible to make the supply air temperature stable regardless of the weather. The soil temperature below the freezing point remains at +10 - +14 degrees.

• Operating costs are negligible. Here is a table of the dependence of the power consumed by the fan on its performance.

Implementation

Implementing the scheme yourself required minimal expenditure of time and money.

• Air flow is organized in living rooms. The openings in the floor are covered with grilles with mesh to protect against insects.

• Exhaust grilles are installed in plasterboard, covering the channel between the crossbar and the wall.
• A hole was punched from the channel to the street into which an exhaust pipe with duct fan and an umbrella to protect from rain and snow. The pipe is foamed and puttied; The fan is equipped with a remote switch.

Total expenses amounted to about 1,500 rubles. The humidity level in the house has stabilized at a comfortable level; the temperature in winter with the heating turned off is at least +12C.

Conclusion

We hope that our miniature review of methods for organizing ventilation will be useful to the reader.

As always, the video in this article contains additional thematic materials. Good luck!

Page 5 of 5

4. VENTILATION

4.1. In mass housing construction, the following scheme for ventilation of apartments has been adopted: exhaust air is removed directly from the zone of greatest pollution, i.e. from the kitchen and sanitary premises, through natural exhaust duct ventilation. Its replacement occurs due to outside air entering through leaks in the external fences (mainly window filling) of all rooms of the apartment and heated by the heating system. This ensures air exchange throughout its entire volume.

When apartments are occupied by families, which is what modern housing construction is aimed at, interior doors are usually open or have the door leaf trimmed, which reduces their aerodynamic resistance in the closed position. For example, the gap under the doors of the bathroom and toilet should be at least 0.02 m high.

The apartment is considered as a single air volume with the same pressure.

Air exchange is regulated based on the minimum required amount of outside air per person according to hygienic requirements (approximately 30 m 3 /h) and is referred to the floor area conditionally. An increase in the occupancy rate, as well as an increase in the height of the premises, is not associated with the indicated amount of air.

It is not recommended to remove air directly from rooms in multi-room apartments, since this disrupts the pattern of directional air movement in the apartment.

4.2. SNiP “Residential Buildings” regulates a two-fold approach to the calculated air exchange: living rooms - 3 m 3 / h per 1 m 2 of floor; kitchens and bathrooms - from 110 to 140 m 3 / h (depending on the type kitchen stoves). The first of these values ​​is taken into account in the heat balance (see Section 2), the second - when calculating ventilation units. The difference in approach to rationing has no physical basis. In this regard, it is recommended: for apartments with a living area of ​​less than 37 m2 (with electric stoves) and 47 m2 (with gas stoves) the performance of exhaust ventilation should be taken based on the norms of bathrooms and kitchens; for apartments with a living area of ​​37 (47) m2 or more - according to the sanitary standard for living rooms. The given areas of apartments are determined from the conditions of equality of air exchange according to the sanitary norm and the norm for kitchens and bathrooms.

4.3. The calculated air exchange (clause 4.2) should be understood as the replacement of air removed from apartments with outside air in a standard volume. When assessing the amount of air exchange in an apartment, one should not take into account the amount of air coming from other rooms (staircase, adjacent apartments).

4.4. In accordance with clause 4.22 of SNiP 2.04.05-86, the design conditions, i.e., the worst, for natural exhaust ventilation are: outdoor air temperature +5°C, calm, indoor air temperature +18 (+20)°C, the windows are open. Under these conditions, the throughput of the ventilation units is calculated. When the outside temperature drops and there is wind, the windows are closed, after which the pressure available for the ventilation system is spent on overcoming the resistance of two elements: the window filling and the exhaust ventilation network. Thus, air exchange in an apartment is a function of the resistance to air permeation of external enclosures and weather conditions. Taking into account the change in available pressure during heating season(10-15 times) and the tendency towards a maximum reduction in the air permeability of windows (to reduce the excess heat consumption at low outside temperatures), a transition from unorganized variable infiltration is necessary (both in time for one room and for the building in height and orientation of the facades relative to the direction wind) to an organized, controlled flow of outside air using special devices.

The performance of exhaust ventilation during the warm season is not standardized due to the possibility of air exchange through open windows.

The consumer should be able to change the air permeability of windows, following changes in meteorological conditions and focusing on his own thermal sensations, however, known elements standard windows(windows, narrow sashes) do not provide a normal inflow due to the difficulty of smoothly regulating their opening. Coming through them outside air creates discomfort in the working area of ​​the premises (a feeling of blowing). These elements can be used for burst ventilation, but are not suitable as constantly operating air supply devices that provide standard air exchange in apartments.

4.5. To ensure an organized flow of outside air into the premises of residential buildings, it is recommended to use adjustable air supply devices. They must meet the following requirements:

absence of discomfort in temperature and air mobility in the living area;

tightness of the device valve in the closed position;

the thermal resistance of the supply valve is not less than the thermal resistance of the window filling;

possibility of smooth regulation over the entire range - from fully open to fully closed position;

aesthetics.

4.6. Air supply devices as one of the possible options It is recommended to make it in the form of a horizontal slot 15 mm wide in the upper part of the window frame with a valve on the lower suspension (Fig. 1). In this case, the flow of outside air using a valve and under the influence of a convective flow from heating device under the window it deflects to the ceiling of the room, descending into the living zone, usually at some distance from the window, with parameters close to those of the internal air. The length of the supply unit is 200 mm less than the length of the window block (100 mm on each side). In the middle of the gap (if its length is more than 1000 mm) a spacer 40 mm wide is made.

Rice. 1. Adjustable air supply device

The valve has a 10 mm thick sealing gasket made of polyurethane foam or foam rubber and covers the gap by 15 mm on each side.

The valve is equipped with a simple shut-off and control device with remote control, providing smooth adjustment of its position and locking.

The described supply devices were tested in experimental construction in climatic regions I, II and III and received the approval of hygienists (IOCG named after A. N. Sysin).

TsNIIEP engineering equipment develops working documentation for air supply devices in relation to windows of various designs and provides scientific and technical assistance in their implementation.

4.7. The incentive for consumer regulation of air supply devices is the individual perception of air-thermal comfort within the limits of the standard heat supply. Regulation of air exchange based on internal air temperature provides the consumer with ample opportunities to maintain the desired level of air-thermal comfort, depending on the specific operating mode of the apartment.

4.8. Exhaust ventilation with natural impulse is usually performed in accordance with the diagrams, Fig. 2. The circuit shown on the right is preferable. In this case, each apartment is connected to the prefabricated exhaust duct through a travel companion.

Rice. 2. Possible schemes for natural duct exhaust ventilation

The ventilation network is formed from floor blocks standardized according to the height of the building.

4.9. Air is released into the atmosphere:

a) in a cold attic through exhaust shafts that complete each vertical of the ventilation units and pass in transit through attic space.

The use of prefabricated horizontal ducts in a cold attic is inevitably associated with an increase in the resistance of the general section of the ventilation network and, as a rule, leads to periodic disruptions in air circulation in the system;

b) in a warm attic through a common exhaust shaft, one per section of the house, located in the central part of the corresponding section of the attic. In this case, air from the ventilation ducts of all apartments enters the attic volume through the heads in the form of a diffuser.

When calculating and installing a warm attic and a prefabricated exhaust shaft, you should use the Design Recommendations reinforced concrete roofs with a warm attic for multi-storey residential buildings / TsNIIEP housing. - 1986.

It is not recommended to allocate a separate channel in the head for the upper floor, since this eliminates the ejection of air from the companions of the upper floors.

4.10. When designing ventilation units, it is recommended:

strive for a minimum number of exhaust ducts (as a rule, a prefabricated one - one, companions of a minimum length, but not less than 2 m);

ensure the stability of the geometry of individual units during the manufacturing process of ventilation blocks;

ensure that the throughput of all channels of the ventilation unit is maintained within the design tolerances for its displacement during the installation process.

The use of left- and right-handed ventilation units is undesirable due to frequent violations of the ventilation circuit during installation.

4.11. Natural exhaust ventilation of a residential building is complex hydraulic system, the calculation of which requires a special program for mathematical modeling on a computer.

A simplified calculation can be carried out using the TsNIIEP engineering equipment methodology.

Calculation of natural exhaust ventilation is aimed at:

to determine the cross-section of channels and the geometry of their merging nodes, as well as the entrances to the channels of ventilation units, ensuring their nominal throughput;

to determine the scope of application of existing or newly developed ventilation units, depending on the number of storeys and other structural and planning solutions of buildings.

4.12. To reduce errors when performing exhaust ventilation in various buildings, it is necessary to maximize the unification of currently used and newly developed ventilation unit designs and reduce their range, which can be done on the basis of a simplified calculation of ventilation units (see 4.11).

4.13. Increasing the operational reliability (preventing “tipping over” of the air flow) of the natural exhaust ventilation system and at the same time reducing material consumption and labor costs are achieved when using one vertical exhaust ducts per apartment through the use of combined ventilation units. An example of a solution for a combined ventilation unit combined with a sanitary cabin is shown in Fig. 3.

Rice. 3. Combined ventilation unit combined with a plumbing cabin

1 - “hood” with ventilation block; 2 - the bottom of the engineering cabin; 3 - sealing gasket; 4 - wire stops, 5 - interfloor covering

The use of two combined or combined and separate ventilation units in zoned apartments leads, as a rule, to excessive intensification of air exchange and is therefore undesirable.

When using two ventilation units in the same vertical of apartments, it is necessary to ensure the same conditions for the exhaust of ventilation air into the atmosphere (in particular, the emission mark in the case of independent mines).

4.14. The use of identical ventilation units along the height of the building determines the unevenness of air removal along the vertical of the apartments.

Increasing the uniformity of air flow distribution is achieved by increasing the resistance of the entrance to the ventilation unit or ensuring that the resistance value of the entrance to the ventilation unit varies along the height of the building. The latter can be done using ventilation grilles with mounting adjustment (for example, the design of TsNIIEP engineering equipment) or special linings (for example, made of hardboard) with holes of different sizes at the entrance to the ventilation unit.

Expanding the scope of application of ventilation units for buildings of different heights and changing their nominal performance (see clause 4.2) is possible with the help of specially designed linings.

4.15. The design and installation technology of ventilation units must provide for the possibility of sealing their interfloor joints.

The tightness of the ventilation network is of particular importance for natural exhaust ventilation. The presence of leaks not only leads to excessive air exchange in apartments on the lower floors multi-storey buildings, but also to the emissions of polluted air through them from the collection channel into the apartments of the upper floors. Projects must include special technology sealing interfloor joints of ventilation blocks using elastic gaskets.

4.16. Sustainable removal of air from apartments on the upper floors is ensured by making the right choice ventilation blocks for buildings of a specific number of storeys and attic design.

The installation of exhaust fans at the entrance to the ventilation unit of the two upper floors, provided for by SNiP, worsens air exchange in apartments, since the fans are not designed for constant operation, and during periods of inactivity they make it difficult to remove air due to excessive resistance.

4.17. The structures of transit sections of ventilation units passing through cold or open attics, as well as ventilation shafts on the roof, must have a thermal resistance not less than the thermal resistance of the external walls of residential buildings in a given climatic region. To reduce the weight and dimensions of these structures, as provided for in this paragraph, thermal resistance can be achieved through effective thermal insulation. The same applies to the ventilation sections of sewer risers and garbage chutes.

3. HEATING "