Office ventilation: sanitary standards for the supply and exhaust system, room standards. Air exchange rate according to SNP for various premises Sanpin for ventilation of industrial premises

Ventilation is the removal of air from premises and its replacement with clean outside air. Ventilation ensures the condition of the air environment in the premises in accordance with sanitary and hygienic requirements. In residential and public buildings, the life activity of people, everyday processes (cooking, washing clothes, etc.) are accompanied by a decrease in oxygen content in the air, accumulation of heat and moisture, as well as indoor air pollution with foul-smelling substances and necessitate constant or periodic replacing it with a fresh one. The intensity of such replacement is usually determined by the ratio of the hourly volume of replaced air to the volume of the room, i.e., the exchange rate per hour. In accordance with sanitary hygienic requirements standards for the frequency of exchange have been established for residential, children's, school and hospital premises(table).

Ventilation of industrial premises is the most important means of combating the release of harmful gases, vapors, dust, excess heat and moisture. The sources of these emissions are technological processes, production equipment and people. However, such a fight should begin with measures that prevent or reduce these emissions (localizing the source of unfavorable emissions through shelters with air suction - local suction). Non-localized secretions are removed using ventilation. The required air exchange is determined by the formula:
where g is the hourly amount of harmful substances released into the premises in mg/hour; Efficiency - maximum permissible concentration of a harmful substance () and Kp. - concentration of this substance in the introduced air in mg/m3.

Ventilation air exchange in residential and some public premises

Air exchange in rooms is carried out in various ways: 1) natural ventilation - through windows, doors, pores in the walls, due to the difference between the air pressures outside and inside; 2) artificial ventilation - using mechanical devices.

The effectiveness of natural ventilation depends on the area of ​​vents, transoms (which should be at least 1/40 of the floor area), the temperature difference between indoor and outdoor air, and the degree of porosity of the walls.

Artificial ventilation ensures constant air exchange in the room. It can be exhaust, supply or supply and exhaust and is carried out using axial and centrifugal fans (Fig. 1 and 2).

Rice. 1. Axial fan: 1 - wheel with blades; 2 - casing.
Rice. 2. Centrifugal fan: 1 - casing; 2 - bed; 3 - outlet; 4 - suction hole.

Rice. 3. Air conditioning installation: 1 - opening for incoming outside air; 2 - mixing chamber; 3 - irrigation chamber; 4 - chamber with separators to retain water droplets; 5 - centrifugal fan; 6 - pump for water supply; 7 - heater; 8 - intermediate chamber.

The exhaust system consists of a fan with an electric motor and air ducts. Air in industrial premises contaminated with dust, harmful gases or vapors must be cleaned before being released outside. The supply air is pre-treated to create a favorable microclimate (see) in the room. Therefore, the supply system, in addition to fans, electric motors and ducts, includes heaters (heaters), filters or dust chambers, humidifying or washing chambers, refrigeration and drying units. When it becomes necessary to maintain constant temperature and relative conditions in a room, devices for so-called air conditioning are used (Fig. 3).

Sanitary standards in the USSR related to ventilation devices are concentrated in the following documents: Sanitary design standards industrial enterprises CH-245-63 (section 4B); Construction norms and rules SNiP II-G. 7-62 “Heating, ventilation and air conditioning”; Design standards SNiP II-M. 3-68 "Auxiliary buildings and premises of industrial enterprises."

The task (preventive and current), carried out mainly by employees (SES), includes checking compliance with the main provisions of these documents.

When checking the operation of ventilation, you should pay attention to the correctness of its use, namely: so that not only the exhaust units work, but also the supply units; so that the supplied supply air does not create unpleasant blast; that the microclimate conditions correspond to the permissible ones, and that the air samples taken do not contain harmful substances above the maximum permissible concentration. When monitoring, you should use flags and artificial haze. To control air pollution, chemical laboratories of SES or enterprises should be involved.

The air exchange rate according to SNiP is sanitary indicator indoor air conditions. The comfort and safety of people staying in a particular room depends on its value. The permissible value of this parameter is regulated by state building codes and rules that determine different requirements for all erected buildings.

General information

Before defining optimal indicator the air exchange rate according to SNiP in premises (residential or industrial), it is necessary to study in detail not only the parameter itself, but also the methods of its calculation. This information will help you choose the most accurate value that is suitable for each specific room.

Air exchange is one of the quantitative parameters characterizing the operation of the ventilation system in enclosed spaces. In addition, it is considered the process of replacing air in the internal spaces of a building. This indicator is considered one of the most important in the design and creation of ventilation systems.

There are two types of air exchange:

1. 1. Natural. It occurs due to the difference in air pressure inside and outside the room.
2. 2. Artificial. This is done through ventilation (opening windows, transoms, vents). In addition, it includes the entry of air masses from the street through cracks in walls and doors, as well as through the use of various systems air conditioning and ventilation.

The air exchange rate is a parameter showing how many times (within 60 minutes) the air in the room was completely replaced with new one.

Its value is determined not only by SNiP, but also by GOST ( state standard). The set of measures that need to be taken to maintain optimal conditions V residential apartments and office premises.

Ventilation in the apartment. What is natural ventilation in an apartment?

Calculation rules

Most newly constructed buildings are equipped with sealed windows and insulated walls. This helps reduce heating costs during the cold season, but leads to a complete cessation of natural ventilation. Because of this, the air in the room stagnates, which causes the rapid proliferation of harmful microorganisms and a violation of sanitary and hygienic standards. Therefore, in new buildings it is important to provide for the possibility of implementing artificial ventilation air, taking into account the multiplicity index.

Air exchange standards in premises (residential or industrial) depend on several factors:

• purpose of the building;
• number of installed electrical appliances;
• thermal output of all operating devices;
• the number of people who are constantly in the room;
• level and intensity of natural ventilation;
• humidity and .

The air exchange rate can be determined using the standard formula. It involves division required quantity clean air, entering the building in 1 hour per room volume.

Thanks to natural aeration, this figure can reach 3 or 4 times per hour. If significantly more frequent air exchange is required, then mechanical ventilation is used.

Values ​​for different buildings

In order for people in a particular room to feel as comfortable as possible, it is necessary to comply with the air exchange rates stipulated by building codes and regulations. They differ significantly for different buildings, so you should approach their choice with maximum responsibility. Only in this case can you achieve the desired result and create a ideal conditions to find people.

All residential buildings require provision of not only artificial, but also natural air flow. If one of them is not enough, then it is allowed to use combined option. At the same time, it is also necessary to ensure the removal of stagnant oxygen. This can be done by arranging ventilation ducts from the following premises:

• bathroom;
• restroom;
• kitchen.

Besides this, everything modern buildings are equipped with special autonomous air valves. They can be opened and closed by apartment owners, and also perform the function of removing stagnant air.

The frequency of air exchange in a residential area is indicated in SNiP 2.08.01−89. According to these standards, the indicator should be like this:

• Separate room in the apartment (bedroom, children's room, playroom) - 3.
• Bathroom and individual restroom - 25 (if combined, the value should be 2 times greater).
• Dressing room and washroom in the dormitory - 1.5.
• Kitchen with electric stove - 60.
• Kitchen with gas equipment - 80.
• Corridor or lobby in an apartment building - 3.
• Ironing, drying, laundry in the dormitory - 7.
• Pantry for storing sports equipment, personal and household items - 0.5.
• Elevator machine room - 1.
• Staircase - 3.

Calculation of air exchange in the boiler room ( detailed analysis)

In office centers

The size of the air exchange rate for administrative buildings and offices are much larger than for residential premises. This is due to the fact that the ventilation and air conditioning system must efficiently cope with heat emissions emanating not only from workers, but also from various office equipment. If you properly equip the ventilation system, you can improve the health and increase the productivity of employees.

Basic requirements for the system:

• filtration, humidification, heating or cooling of air before supplying it to the room;
• ensuring a constant supply of sufficient fresh oxygen;
• arrangement of exhaust and supply ventilation systems;
• the use of equipment that will not create much noise during air exchange;
• the most convenient location of installations for the convenience of carrying out repair and preventative measures;
• the ability to adjust the parameters of the ventilation system and adapt its operation to changing weather conditions;
• the ability to provide high-quality air exchange with minimal energy consumption;
• the need to have small dimensions.

All these requirements will help you quickly remove from indoors exhaled carbon dioxide and fumes coming from operating equipment.

For correct settings air conditioning and ventilation systems, it is necessary to accurately calculate the multiplicity and compare it with the standards of SNiP 31−05−2003, which provide such meaning:

Production workshops

It is especially important to ensure good air exchange in industrial premises, where people work in the most harmful conditions. To reduce the negative impact on their health, it is necessary to properly equip the ventilation system and calculate the air exchange rate.

To total values influenced by several main factors:

Define optimal value air exchange rate for industrial premises according to the SNiP table 2.04.05−91. It indicates the value of this parameter for each specific room.

• Shops where work is performed that does not require much physical effort - 25.





The main ones are:



The air exchange rate, standardized according to SNiP, is one of the most important indicators of the air condition in a particular room. If it is calculated correctly and all recommendations provided by standard standards are followed, you can significantly increase the quality of aeration, as well as make people’s stay in the room more comfortable and safe.

Ventilation is a technical means that completes the system of measures to improve the air environment of working premises (the most important prerequisite for preventing air pollution in industrial premises is rational organization production processes: sealing and process continuity with remote control and control, automation and mechanization).

Ventilation, heating and air conditioning of production premises and structures (including crane operator cabins, control panel rooms, and other similar isolated rooms) are arranged to ensure that at permanent workplaces and in the work area during basic and repair and auxiliary work necessary in accordance with hygienic requirements meteorological conditions, air purity at work (temperature, relative humidity and air speed, maximum permissible concentrations of harmful substances and dust). Industrial ventilation ensures the fight against excess heat and moisture by creating a general air exchange, as well as removing harmful gases, vapors, dust entering the air of working premises through the use of local, localized ventilation units (see also “SSBT. Gas-cleaning dust collection equipment.” GOST 4.125 -84; "SSBT. Blowout prevention equipment". GOST 12.2.11586).

During the sanitary examination of ventilation projects in expert opinion The following main questions are reflected:

1) characteristics of the system and the correctness of its choice; 2) assessment of the supply system: a) place and method of intake of supply air and devices for its cleaning, heating and humidification, b) location and arrangement of supply openings in the premises, temperature and supply speed of supply air, c) assessment of the sufficiency of air exchange according to the supply (test calculation), d) cubic capacity of the room per person, air cube and exchange rate, e) recirculation, its admissibility and scale; 3) assessment of local air supply units: direction of air shower inflow, supply air temperature, air supply speed; 4) system assessment exhaust ventilation: a) device and location of the openings for general exhaust ventilation, b) arrangement of localizing shelters, c) initial speed of air movement in the openings, d) device for cleaning the air removed from the room, e) assessment of the location of the release of the removed air, f) air exchange along the hood ( verification calculation);

5) characteristics and assessment of the ventilation system as a whole: the ratio of the places of supply air intake and the places of exhaust air, the ratio of the location of supply and exhaust openings in the room, the air balance of the room (i.e. the ratio of the total amount of supply and exhaust air). For a detailed description of the requirements, see “Sanitary standards for the design of industrial enterprises” (SN 245-71) and the section “Heating, ventilation and air conditioning” (SNiP 11-33-75), industry design guidelines (issued by individual departments with mandatory approval from Main Sanitary and Epidemiological Directorate of the USSR Ministry of Health).

In the absence of industrial emissions, air exchange must be organized in rooms with a cubic capacity of less than 40 m3 per worker.

The amount of air required to ensure the required air parameters in the working area is determined engineering calculation. At the same time, the uneven distribution of harmful substances, heat and moisture along the height of the room and in the working area is taken into account, namely for rooms with heat emissions - according to excess sensible heat; for rooms with heat and moisture releases - based on excess sensible heat, moisture and latent heat, checking to prevent moisture condensation on the surfaces of building structures and equipment. In those rooms where there are gas emissions, the amount of air that needs to be supplied to the room should provide dilution chemical substances up to the maximum permissible concentration. The amount of harmful emissions is taken either according to the technological part of the project or technological design standards, or according to data from natural surveys of similar enterprises, or by calculations. If there are simultaneously several harmful substances, heat, and moisture in the room, the amount of supply air when designing ventilation is taken to be the largest, obtained from calculations for each type of industrial emissions.

Emissions cleaning. Technological emissions and emissions of air removed by local suction, containing dust, poisonous gases and vapors, and unpleasant-smelling substances, must be arranged in such a way as to ensure the dispersion of these substances and so that their concentration does not exceed:

a) in atmospheric air settlements- maximum permissible maximum one-time values; b) in the air entering buildings through openings of ventilation and air conditioning systems and through openings for natural supply ventilation - 30% of the maximum permissible concentration of harmful substances in the working area of ​​industrial premises.

Ventilation air removed by general ventilation and containing the above-mentioned impurities must be purified before being released into the atmosphere, taking into account that in places of air intake by ventilation and air conditioning systems, the content of harmful substances in the outside air does not exceed 30% of the maximum permissible concentration for working area production premises. If ventilation emissions contain low concentrations of harmful substances, then cleaning may not be carried out, but the dispersion of harmful substances in the atmospheric air under the most unfavorable weather conditions should meet the above requirements.

Forced ventilation. Recycle. In production premises with a volume per worker of less than 20 m3, a supply of outside air in an amount of at least 30 m3/h per worker must be organized, and in premises with a volume per worker of more than 20 m3 - at least 20 m3/h per worker. every worker. If there is more than 40 m3 of room volume per worker in the presence of windows and lanterns and in the absence of the release of harmful and unpleasantly smelling substances, it is allowed to provide periodic natural ventilation - opening the casements of windows and lanterns. When designing buildings, premises and their individual zones (sections) without natural ventilation (airing) with mechanical ventilation supplied only from outside air, the volume of outside air should be at least 60 m3/h per 1 worker, but not less than one air exchange per hour according to the entire volume of the room (with air conditioning with recirculation - with a calculated air exchange rate of 10 times or more). With a lower design air exchange rate and when recirculation is used, the volume of outside air supply should be at least 60 m3/h per 1 worker, but not less than 20% of the total air exchange (the volume of outside air supply is up to 10% if the air exchange rate is less than 10 and recirculation - if more 120 m3/h of outside air per 1 worker.

When designing general supply and exhaust ventilation of premises without natural ventilation, at least two supply and two exhaust units must be provided, each with a capacity of at least 50% of the required air exchange (with one installation - backup fans).

When designing ventilation and air heating, recirculation can be allowed during the cold and transition periods of the year (for air conditioning systems - at all times of the year). For recirculation, you can use room air where there are no harmful emissions or if the released substances belong to hazard class IV and their concentration in the room air does not exceed 30.% of the maximum permissible concentration. Application of air recirculation for ventilation, air heating and air conditioning is prohibited in rooms in which:

a) the air contains microorganisms;

b) there are pronounced unpleasant odors; c) substances of hazard classes I, II and III are released in the air.

Air and air-heat curtains must be installed at gates that open at least 5 times per shift or at least 40 minutes per shift. These curtains are also installed at technological openings of heated buildings and structures in areas with a design outside air temperature for heating design of 15 °C or lower in the absence of airlock vestibules. When opening gates, doors and technological openings, the air temperature at permanent workplaces during operation of the curtains should not be lower than: 14 °C at light physical work, 12 °C - for moderate work, 8 °C - for heavy work (in the absence of permanent workplaces near gates and openings - up to 5 °C).

The temperature of the air mixture passing through the gate or openings must meet the specified standards.

Exhaust ventilation. The combination of dust and easily condensable vapors, as well as substances that, when mixed, produce harmful mixtures or chemical compounds, into a common exhaust system is prohibited. Local exhaust systems for removing harmful substances of hazard classes 1 and 11 must be interlocked with process equipment so that it cannot operate when local exhaust ventilation is inactive (with the exception of installing backup fans for local exhaust units with automatic switching). When installing local exhaust ventilation, it is necessary to observe the following requirements: 1) sources of harmful emissions must be covered as much as possible; 2) the design of the suction air intake and its location - take into account the natural movement of emissions (convection air flows, the direction of the dust stream, the direction of gas movement, etc.); 3) the breathing zone of workers - to be outside the shelter; 4) the flow of the technological process and the ease of servicing the equipment - not to be disturbed; 5) in the shelter, by suctioning air, a vacuum must be created to prevent the entry of harmful emissions into the air of the room.

General ventilation. To dilute to the maximum permissible concentration that part of the production emissions that cannot be removed using local exhaust ventilation, general mechanical ventilation is installed. The location of the air exhaust zone depends on the nature of the harmful emissions. In the presence of heat emissions or light gases and vapors, the joint release of heat and chemicals, the exhaust air is removed from the upper zone of the room; Air removal (usually partially) from the lower zone is carried out in the event of the release of heavy specific gravity gases and vapors. Air is removed from the upper and lower zones when it is simultaneously contaminated with a mixture of gases and vapors, one of which is lighter and the other is heavier than air. You draft receivers should be located in areas of the highest temperatures and the greatest air pollution.

Supply air is usually supplied to the work area in the following cases: a) during the release of heat and the joint release of heat and gases; b) when installing exhaust from an area with the highest dust concentrations above the working area (welding shops, etc.). Supply air is released into the upper zone of the premises in the absence of significant excess heat and dust and gases are sucked out by local exhaust ventilation, with lower exhaust in rooms with the release of vapors of volatile solvents or dust, in rooms with excess heat when cold air is supplied. In the presence of moisture release, supply air is supplied to two zones - the upper (heated) and the lower.

Local inflow is arranged to create limited zones with a favorable microclimate and low concentrations of harmful air impurities (air showers, air oases).

In industries where large quantities of harmful substances (except dust) may suddenly enter the air of the working area, emergency (usually exhaust) ventilation should be provided in accordance with the requirements of SNiP and departmental standards. If departmental standards do not contain instructions on the air exchange of emergency ventilation, then together with the existing ventilation it must provide an air exchange of at least 8 exchanges per 1 hour in the internal volume of the room. It is recommended to provide for blocking emergency ventilation with gas analyzers that determine permissible concentrations of harmful substances. To start emergency ventilation, remote devices must be installed in accessible places and outside the room.

Ventilation, air conditioning and heating installations should not create noise above permissible values ​​(see noise standards).

Heating. For heating buildings and structures, systems, devices and coolants must be used that do not create additional industrial hazards. The use of radiant heating with infrared gas emitters is permitted provided that combustion products are removed to the outside. In heating systems, the average temperature of the heating surface should not be higher than:

a) on the heated floor surface 26 °C (in lobbies and rooms with temporary occupancy of people 30 °C); b) on the heating surface of the ceiling at a height of 2.5-2.8 m 28 ° C; at a height of 2.9-3 m 30 ° C; at a height of 3.1-3.4 m 33 ° C;

c) on the heating surface of partitions and walls at a height of up to 1 m from the floor 35 °C, from 1 to 3.5 m 45 °C. Heating devices in rooms with significant dust emissions must have smooth surface, which makes them easier to clean.

Supply heating and ventilation equipment and air conditioners that serve the premises without recirculation are placed in isolated rooms.

Each enterprise must have a designated person responsible for the operation and condition of ventilation, heating, and air conditioning. All ventilation units, both newly equipped and put into operation after reconstruction or overhaul, are subjected to instrumental acceptance tests to determine effectiveness.

Each enterprise must establish a procedure for operating ventilation and heating in accordance with specially developed instructions and passports (for ventilation units). The instructions contain instructions on how to regulate the operation of each unit (system) in relation to the operating mode of the workshop (department) and technological equipment (during the working day, during the seasons of the year and at different times of the day depending on meteorological conditions); timing of cleaning air ducts, fans, dust and gas cleaning devices; timing of scheduled preventative maintenance, etc. For all ventilation units, a passport is drawn up in a certain form, in which all changes in the installation, the results of tests carried out at the request of the sanitary-epidemiological station are entered. An operation log must be kept for each ventilation system (kept by the workshop manager). In rooms where chemicals, dust and other harmful substances may be released into the air, it is necessary to systematically test the air for the content of harmful substances within the time frame determined by local sanitary inspection authorities.

Control of ventilation units. The effectiveness of ventilation is determined only on a working ventilation unit. The air supply unit must have air heaters in working order, valves and openings for air intake must be open. Check the water temperature and the addition of steam entering the heaters, the purity of the supplied air; determine the temperature and speed of air flowing out of the supply pipes into the working room.

When checking exhaust devices, special attention is paid to the tightness of the air ducts and, first of all, in the places where the pipes are connected to shelters and main air ducts. It is important to check the tightness of the connections in the flanges of the air ducts; dust and dirt are not allowed to accumulate in them; the suction openings must be open, and the devices for cleaning the air removed from the room must be in good working order. To assess the effectiveness of ventilation, the content of dust and chemicals in the air of working areas during work is determined production equipment on full power. Along with this, the performance (volume of supplied or removed air per 1 hour) of ventilation units is checked and its compliance with design data using either anemometers or pneumometric tubes with a draft gauge. In this case, the speed of air movement in the air duct is multiplied by the area of ​​the ventilation opening (in m2) and by 3600 (the number of seconds); get installation performance in cubic meters air in 1 hour.

If there are grilles in the air duct opening, then to obtain the volume of air passing through the exhaust openings, the result obtained is multiplied by a factor of 0.8. To determine the volume of air passing through the supply openings with grilles, take half the amount instead of the area of ​​the air duct opening overall area holes and free cross-sectional area of ​​the grating. It is impossible to measure the speed of air movement in the air duct with an anemometer, since this changes the nature of the air flow (pneumometric tubes with a draft gauge are used). These studies are carried out by specially trained personnel of ventilation laboratories or SES groups or special laboratories of departments and enterprises.

Sanitary standards for ventilation of premises - SNiP standards

During construction, weight must be taken into account various factors, carry out calculations. But no matter what room you build, special attention should be paid to ventilation.

Air exchange or ventilation rules are clearly stated in the Code of Rules SP 60.13330.2012 “SNiP 41-01-2003. Heating, ventilation and air conditioning.” It is this set of rules that must be followed when creating a project for any building and its construction.

A proper air circulation system will eliminate dampness and stuffiness. In addition, air exchange is directly related to the environment and energy supply.

That is why it is better to choose the type of air exchange at the design stage.

There are three main types of air exchange

1. Natural ventilation of buildings. With this type, air masses move in an organized and unorganized manner. Forced or unorganized ventilation occurs through the natural openings of the structure: various cracks, windows and vents. An organized or exhaust ventilation system represents special exhaust valves installed in buildings.
2. Forced ventilation. This type of air exchange is used in rooms with good sealing. This type is characterized by the use of specialized mechanisms - fans, heat exchangers.
3. Combined air exchange system. This type of ventilation involves a combination of two types. The presence of natural and forced intake of air masses into the building.

For various types structures our legislation has established sanitary standards ventilation of premises.

Ventilation standards for residential premises

To ensure that air in a residential building is of high quality and in sufficient volume, need to follow the rules established by law. After all, human health directly depends on air quality. For each specific residential structure, a specific value is established.

When calculating air exchange in residential buildings method applied specific standards circulation of air masses. It consists of taking into account sanitary and human loads. The balance of incoming air masses with the outgoing air masses is also taken into account. Air flows should move from the room with the best air circulation to buildings where the air quality is lower.

In order to produce correctly necessary calculations two quantities need to be taken into account - the total area of ​​the residential structure and air exchange rates for each person, which is located in this building. To begin with, the first value is set. To do this, the air circulation rate per hour is multiplied by the total volume of the room.

The first value is fixed and equal to 0.35. Then the ventilation norm of the residents is calculated. When making calculations for rooms with a total area less than 20 sq.m. per person it is necessary to multiply the living area by a factor equal to 3.

And for residential buildings with a total area of ​​more than 20 sq.m. per person, you need to multiply the number of residents by the standard air exchange value per person, which is 60. After the calculations, you need to produce exhaust air in additional premises, taking into account their type (kitchen, bathroom, toilet, dressing room). Each type has its own standard. After this, the maximum result is taken into account.

The ventilation system must provide high-quality air environment. In residential buildings, air circulation between apartments is unacceptable, between the kitchen or toilet and living rooms. Autonomous ventilation is required. Exhaust ventilation shafts should protrude above the roof ridge or flat roof to a height of at least 1 m. the concentration of harmful substances in the air should not exceed the norm.

Ventilation standards in office premises

By and large, an office is a production facility with a large number of people in it. The presence of 30-40 cubic meters quality air per person. Fixed for a certain type of office parts different size. For work room and the office it is 60 cubic meters per person, for the reception and meeting rooms - 40 cubic meters, for meeting rooms - 30, the ventilation norm for corridors and halls is 11 cubic meters, for toilets - 75, and in smoking rooms this norm is 100.

Sanitary rules for offices, the percentage of air humidity is set, depending on temperature. At a temperature of 25 degrees, humidity cannot be more than 70 percent, at 26 degrees - 65, and at 27 no more than 60 percent.

Ventilation standards in industrial premises

Production premises are specialized premises. SNiP determines air circulation standards for industrial buildings based on the amount of toxic elements. The air quality in such structures is influenced by many factors - large amounts of dust, excess humidity, special temperature indicators, chemical exposure.

To establish ventilation standards in industrial buildings it is necessary First, calculate the air exchange rate for a specific room. This is a tabular value. So, the multiplicity rate must be multiplied by the total area and height of the above-mentioned building.

Thus, to establish proper ventilation production buildings need to take into account the characteristics of this very production. Namely, the amount of heat generated, liquids or condensate, harmful substances, emissions from equipment, communications and fittings.

For production facilities, according to sanitary standards, one working person should receive not less than 30 cubic meters per hour, if the building area is less than 20 cubic meters. With a total area of ​​more than 20 cubic meters per person, there should be no 20 cubic meters per hour. And in buildings without natural ventilation, at least 60 cubic meters per person.

Ventilation standards in warehouses

Warehouses are buildings designed to store certain goods and cargo. And the shelf life of the warehouse contents largely depends from its microclimate - temperature, air mobility and humidity. Depending on the characteristics of the warehouse contents, combined and coercive systems ventilation. Ventilation in a warehouse should completely replace the air in an hour - this is a multiple of one.

For warehouses in which gasoline, kerosene, oils and volatile substances are stored, and personnel are located there temporarily, the multiplicity is 1.5-2, if constant - 2.5-5. Warehouses with cylinders liquefied gases and nitro varnishes - 0.5, when people are temporarily in it. In warehouses for storing flammable liquids, the multiplicity for temporary occupancy of people is 4-5, temporary - 9-10. In storage rooms toxic substances hourly multiplicity – 5, during temporary stay.

March 16th, 2017 y.geny

You can order a range of works for the calculation, selection and installation of a ventilation and air conditioning system for your premises, building, office from our company: .

Work ability office worker directly depends on the indoor microclimate. According to medical research, the air temperature in the office should not exceed 26 degrees, while in practice in buildings with panoramic windows and an abundance of equipment it can go beyond 30 degrees. In the heat, the reaction of employees is dulled, and fatigue increases. Cold also has a bad effect on work ability, causing drowsiness and lethargy. Lack of oxygen and high humidity create unbearable conditions for employees, reducing labor productivity and, therefore, the profitability of the enterprise.

To maintain optimal temperature and humidity conditions, an office ventilation system is installed.

Office ventilation requirements

Ventilation in an office building must meet the following requirements:

• ensuring a flow of fresh, clean air;
• removal or filtration of exhaust air;
• minimum noise level;
• accessibility in management;
• low power consumption;
• small size, the ability to fit harmoniously into the interior.

The load on office climate systems is significantly higher compared to household ones. It is required to efficiently remove excess heat and carbon dioxide generated by equipment and employees, and supply clean and filtered air at a given temperature.

Previously used natural systems office ventilation today is not able to provide conditions regulated by sanitary standards. The operation of natural ventilation cannot be controlled; its effectiveness is highly dependent on the air parameters outside. In winter, this method threatens to cool the room, and in summer it causes drafts.

Widely used in the construction of office buildings, modern hermetically sealed windows and doors and continuous panoramic glazing prevent the passage of air from outside, causing it to stagnate and deteriorate people’s well-being.

All ventilation requirements office premises indicated in SanPiN (Sanitary rules and regulations) 2.2.4.

According to the document, the humidity in the premises should be:

• at a temperature of 25 degrees – 70%;
• at a temperature of 26 degrees – 65%;
• at a temperature of 27 degrees – 60%.

Office building ventilation diagram

The following ventilation standards in offices have been developed, taking into account the purpose of the room, in cubic meters per hour per person:

• manager's office - from 50;
• conference room – from 30;
• reception - on average 40;
• meeting room – 40;
• employee offices – 60;
• corridors and lobbies - at least 11;
• toilets – from 75;
• smoking rooms – from 100.

SanPiN for ventilation of office premises also regulates the speed of air movement of 0.1 m/s, regardless of the time of year.

As a rule, ventilation of small office premises is carried out using several air handling units. If during the hot season the office supply ventilation is not able to lower the air temperature below 28 degrees, additional air conditioning is required.

Separate air handling units are needed in conference rooms. Additional exhaust devices– in toilets, smoking rooms, corridors and lobbies, copy rooms. Mechanical exhaust from office rooms is necessary if the area of ​​each office is more than 35 square meters. meters.

If the total area is not more than 100 sq. meters and there are 1-2 toilets, natural supply ventilation is allowed in the office through the vents. Supply and exhaust ventilation is installed in medium and large sized offices.

Office ventilation system project

The ventilation system of an office building has a number of functions. Therefore, when designing, many factors are taken into account, regulated by SNiP rules for ventilation of office premises No. 2.09.04.87 and 2.04.05.91. The system is assembled from units of varying cost, functionality and design. The task of designers is to choose them correctly.

The following points are agreed upon with the customer:

• location of the ventilation unit;
• location of ventilation ducts;
• power of the electrical system, possibility of water supply;
• the need and ways of the drainage system;
• access to equipment after installation;
• possibility of design changes.

Design of ventilation systems for offices includes:

• calculations of heat inflows for each separate room depending on the architectural features, appointments taking into account terms of reference to the project;
• calculation of air exchange;
• axonometric diagram of communications;
• aerodynamic calculation, which makes it possible to determine the cross-sectional area of ​​air ducts and pressure losses along the network;
• selection of all necessary equipment to complete the ventilation system in the office;
• calculation of heater power in the air handling unit;
• preparation of a package of project documents.

Technical equipment is selected simultaneously with the preparation of the project and takes into account all the customer’s requirements. A properly designed ventilation system for any office increases employee productivity by 20% or more.

Components of office ventilation systems

Air ducts

Air is delivered to the room and removed through an air duct system. The air duct network directly contains pipes, adapters, splitters, turns and adapters, as well as diffusers and distribution grilles. The diameter of the air ducts, the resistance of the entire network, the noise from the ventilation operation and the power of the installation are closely interrelated. Therefore for optimal performance ventilation during the design process, it is necessary to balance all indicators. This hard work, which can only be performed correctly by professionals.

Air pressure is calculated taking into account the total length of the air channels, the branching of the network and the cross-sectional area of ​​the pipe. Fan power increases when large quantities transitions and branches. The air speed in office ventilation systems should be about 4 m/s.

Air ducts are assembled from flexible corrugated pipes or rigid metal or plastic. Flexible pipes are easier to install. But they resist air movement more strongly and hum. That's why flexible pipes used in small offices. Sometimes the main channels are made of rigid pipes, and the branches to the cabinets are made of flexible ones. But large systems are assembled from rigid pipes.

Air intake grilles

They are installed at the point where air enters the ventilation duct from the street. The gratings protect against the penetration of insects, rodents, and precipitation into the pipe. Made from plastic or metal.

Air valves

Prevents wind from blowing when the ventilation system is turned off. Often an electric drive controlled by automation is connected to the valve. To save money, they use manual drives. Then a check spring valve or “butterfly” is attached to the valve in order to block the outlets of the ventilation ducts for the entire winter.

Air filter

Cleans the supply air from dust. As a rule, coarse filters are used that retain up to 90% of particles with a size of 10 microns. In some cases, it is supplemented with a fine or extra fine filter.

Periodically filtering surface ( metal grid or man-made fibers) must be cleaned. The degree of filter contamination is determined by pressure sensors.

Heater

Used to heat street air in winter, they can be electric or water.

Electric heaters have some advantages compared to water heaters:

• simple automatic control;
• easier to install;
• does not freeze;
• easy to maintain.

Main disadvantage – high price electricity.

Water heaters operate on water at a temperature of 70 – 95 degrees. Flaws:

• complex automatic system management;
• bulky and complex mixing circuit;
• behind the mixing circuit is required special care and supervision;
• may freeze.

But with proper operation it provides significant cost savings compared to an electric heater.

Fans

One of the most important components of the entire ventilation system. The main parameters when choosing: performance, pressure, noise level. There are radial and axial types of fans. For powerful and extensive networks it is preferable radial fans. Axial ones are more productive, but produce weak pressure.

Silencer

Installed after the fan to suppress noise. The main source of noise in an office ventilation system is the fan blades. The muffler filler is usually mineral wool or fiberglass.

Distribution grilles or diffusers

Installed at the outlets of air ducts into rooms. They are in plain sight, so they must fit into the interior and ensure distribution air flow in all directions.

Automatic control system

Monitors the operation of ventilation equipment. Usually installed in the electrical panel. Starts fans, protects against freezing, notifies about the need to clean filters, turns fans and heaters on and off.

Climate control equipment for offices

Supply ventilation unit for office. Brings fresh air from the street directly into the office space. The outflow of air occurs by displacing it into corridors and lobbies. With an area of ​​more than 40 sq. meters the air is evacuated directly from it. Air supply units for office ventilation they are used for areas up to 100 square meters. meters;

• Supply and exhaust office ventilation systems . This is the most widely used type of equipment that provides air outflow, purification and delivery. The kit may include cooling or heating devices, humidifiers. The equipment is very diverse, but supply and exhaust ventilation office should be calculated and installed by professionals. Automatic control over functionality reduces energy consumption and increases efficiency;
• Duct ventilation system in the office. Duct air conditioners with outside air are installed in small and medium-sized offices. Combined with supply and exhaust equipment that brings the outside air temperature to the required level. After which it is served to the rooms;
• Central air conditioning and ventilation in a large office. In large office buildings, the climate is controlled by chiller-fan coil systems and multi-zone VRF systems. The latter consist of many indoor units that provide different temperatures and humidity in the rooms. Central air conditioners are supply and exhaust ventilation in offices with cooling and heating units. This type of climate system is suitable for large offices that are not divided into separate rooms.

Office supply and exhaust ventilation

Duct ventilation of the supply-exhaust system is used for rooms up to 600 sq. m. meters, since the office supply and exhaust ventilation capacity is up to 8 thousand cubic meters per hour.

According to SanPiN standards for ventilation of office premises, 60 cubic meters of air per hour must be supplied per person.

SNiP ventilation of office premises requires air exchange:

• inflow 3.5 times per hour;
• outflow 2.8 times per hour.

The equipment is usually hidden behind suspended ceiling utility room. Air is distributed throughout the offices by a system of ventilation ducts, the outlets of which are hidden behind diffusers or grilles.

The influx of air from the street during office supply ventilation is carried out at a height of two meters above the soil surface. The air is passed through a cleaning system, and if necessary, its temperature is lowered or increased (by an electric or water heater).

The exhaust air is discharged into a ventilation shaft or through a pipe, the end of which is located 150 cm above the roof.

To reduce energy consumption, the supply air is heated by a recuperator. It is a heat exchanger in which heat from exhaust air is transferred to fresh air. Recuperators for office ventilation Rotary and plate types are used. The former have an efficiency of more than 75% and operate in bitter frosts. But during operation, about 5% of the exhaust air enters the room.

Plate recuperators are inexpensive, their efficiency is no more than 65%. But they become icy, and we have to provide heating.

All necessary equipment for air treatment in the supply and exhaust system is located in one relatively small housing. Duct ventilation of office premises is a combination of several modules.

To ensure the required air temperature in the office space, supply and exhaust ventilation is supplemented with air conditioners. Depending on the characteristics of the building, these can be several split systems or multisplits.

Office ventilation

Ventilation of a small office building can be provided by a ducted air conditioner. In addition to cooling and heating the air, duct systems supply some fresh air from the street into the halls. To implement this function, the duct air conditioner is equipped with additional equipment mixing air. That is, the equipment both air-conditions and ventilates the office in accordance with the standards.

This scheme works like this:

Outside air is supplied to the mixing chamber located in front of the air conditioner, here it is mixed with exhaust air. The mixture is fed into the air conditioner, cleaned, brought to the required temperature and sent through ventilation ducts to the offices. The air from here moves into the mixing chamber and further in a circular cycle.

The air conditioner housing is hidden above a false ceiling or in a utility room.

The advantage of a duct ventilation scheme for office premises is its invisibility. But it eliminates the possibility of varying the air temperature in different rooms.

Air handling units in combination with VRF systems for the office

On large areas, installation of channel equipment is difficult, so maintenance large buildings carried out by supply and exhaust ventilation units for offices in combination with chiller fan coils and VRF systems.

The power of such equipment can reach 60 thousand cubic meters per hour. Ventilation and climate control equipment is installed on the roof of the building or in separate rooms.

The installation consists of many modules, which are assembled depending on the needs of the enterprise and taking into account office ventilation standards. The kit may include:

• fan chamber;
• recuperator;
• sound absorber;
• mixing chamber;
• block with filters.

Air movement is carried out through an extensive system of air ducts. The air temperature in the building is maintained by chiller fan coils or VRF systems.

VRF is a multi-zone climate system, capable of maintaining the microclimate of an entire building. It is possible to differentiate the temperature in different rooms. An internal module is installed in each room to keep the temperature within the specified limits. There are no temperature changes typical for household air conditioners. Internal modules can be of any type (floor-standing, cassette, ceiling).

The chiller warms or cools the refrigerant - ethylene glycol. Which is supplied to the heat exchanger - fan coil with forced air movement. Fan coil units are located directly in office rooms. In order for the coolant to move at a given speed, the system is supplemented with a pumping station. Many offices and halls can be connected to one ventilation and air conditioning scheme. And not all at once, but as the need arises.

Central air conditioners for office ventilation

Central air conditioners belong to industrial climate control equipment. They are installed in accordance with SNiP and provide ventilation and air conditioning for office premises. In the air conditioner module, the air is brought to the required temperature and humidity parameters. Air is recirculated (mixing exhaust and fresh), including partial air recirculation. After treatment, the air is supplied to the premises through an air duct system.

The advantage of central systems is the absence of internal modules. At the same time, the air conditioner itself is a rather bulky structure that requires a separate room. The air ducts are also quite voluminous. In this case, the temperature throughout the building will be maintained at the same level.