Estimated parameters of air and the frequency of air exchange in the premises of residential buildings

The air exchange rate in the premises of retail trade enterprises (stores)

Estimated air exchange

For the calculated value of air exchange, the maximum value is taken from the calculations for heat input, moisture input, intake of harmful vapors and gases, according to sanitary standards, compensation for local hoods and the standard rate of air exchange.

The air exchange of residential and public premises is usually calculated according to the frequency of air exchange or according to sanitary standards.

After calculating the required air exchange, the air balance of the premises is compiled, the number of air diffusers is selected and the aerodynamic calculation of the system is made. Therefore, we advise you not to neglect calculation of air exchangeif you want to create a comfortable environment for your stay indoors.

Air exchange rate in the premises of public catering establishments

Notes: 1. The air temperatures in rooms (except for refrigerated chambers) indicated in the table are calculated when designing heating systems.

2. In buffets, bars, cocktail halls, banquet halls located in separate rooms, the air ratio is taken as minus 3.

3. The air temperatures in the refrigerated chambers indicated in the table are maintained around the clock throughout the year. In chambers for the simultaneous storage of meat and fish or meat, fish semi-finished products, take temperatures ± 0 ° C; for vegetable semi-finished products +2 ° С; for storage of all products (1 chamber in the enterprise) ± 2 ° C.

A little about air exchange

As you know, natural ventilation systems are designed in residential buildings.

The places for removing air from the premises are the kitchen, bath, toilet, that is, the most polluted rooms of the apartment. The supplied outside air enters through cracks, windows, doors.

Over time, the materials and construction of windows have improved. The current structures are completely sealed, which does not allow the necessary air exchange and meet the minimum air exchange rate.

Such problems are solved by installing various air supply systems. These are supply valves in the wall and supply valves in windows.

2.Calculation of air exchange

Air exchange - the amount of air required to completely or partially replace the polluted air in the room. Air exchange is measured in cubic meters per hour.

How do they perform calculation of air exchange? In general, air exchange is determined by the type of air pollutants found in a given room.

The main calculations of air exchange are the calculation for the sanitary standards, the calculation for the normalized frequency rate, the calculation for the compensation of local extracts. There is also air exchange for the assimilation of apparent and total heat, for the removal of moisture, for the dilution of harmful substances in the air. Each of these criteria has its own method for calculating air exchange.

Before starting the calculation of air exchange, you need to know the following data:

• the amount of harmful emissions into the room (heat, moisture, gases, vapors) in one hour;
• the amount of harmful substances per cubic meter of indoor air.

Air flow rates for modulated equipment

Source: "Design of public catering establishments" Reference manual to SNiP 2.08.02-89

Application area

1.1. This standard establishes the minimum air exchange rates for outdoor air (outdoor air consumption rates), which ensures the necessary cleanliness (quality) of air in the manned premises and its minimum possible adverse effect on human health. The minimum air exchange rates are not calculated.

1.2. Indoor air quality must be ensured regardless of the adopted ventilation system and air exchange organization scheme.

1.3.This standard applies to all areas that may be occupied by people in residential and public buildings, except for areas for which other regulations or special conditions require greater air exchange than specified in this standard.

1.4. This standard applies to all premises in which the microclimate parameters are ensured in accordance with the requirements of GOST 30494-96 “Residential and public buildings. Indoor microclimate parameters ", SNiP 31-01-2003" Residential apartment buildings ", SNiP 2.08.02-89 *" Public buildings and structures ", SNiP 31-05-2003" Public administrative buildings ", MGSN 3.01-01" Residential buildings ".

1.5. This standard deals with chemical, physical and biological pollutants entering, emitted or generated in a room that can affect air quality.

1.6. This standard does not address factors that influence human perception of air quality, such as:

- unidentified and unexplored pollutants;

- the difference in susceptibility among different people, psychological stress, etc.

1.7. This International Standard proposes two methods for calculating the minimum air exchange rates sufficient to provide an acceptable indoor air quality.

1.7.1. Methodology based on specific air exchange rates: the required air quality is ensured by supplying a certain amount of outdoor air to the room, depending on the purpose of the room and its mode of operation. This technique is recommended to be used to calculate the amount of air exchange in rooms, in which, as a rule, changes in their purpose, the amount and nature of pollutants entering the room during the operation period are not expected.

1.7.2. Methodology based on the calculation of permissible concentrations of pollutants: the required air quality is ensured by supplying a certain amount of outdoor air to the room, depending on the size and nature of the pollutants in the room. This technique is recommended to be used to calculate the amount of air exchange in rooms that can change their purpose and / or mode of operation during operation, in which intense sources of pollutants can be present or appear, etc.

1.8. The design documentation should indicate which of the methods was used when calculating air exchange.

Frequency rate of air exchange in the premises of sports and recreation institutions

Air exchange rates

This table shows the values ​​of the air exchange rate for domestic premises: Air exchange rates for industrial premises and premises with a significant volume:

The above data are taken from the reference books of the well-known Ukrainian company Vents.

Air exchange rate in the premises of a credit and financial institution

General information

Before determining the optimal rate of 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 value as accurately as possible, which is suitable for each specific room.
Air exchange is one of the quantitative parameters characterizing the operation of the ventilation system in closed rooms. In addition, it is considered the process of replacing air in the interior 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. It is carried out with the help of ventilation (opening windows, transoms, vents). In addition, it includes the ingress of air masses from the street through cracks in walls and doors, as well as through the use of various air conditioning and ventilation systems.

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

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

Calculation rules

Most of the newly erected buildings are equipped with sealed windows and insulated walls. This helps to 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 multiplication of harmful microorganisms and a violation of sanitary and hygienic standards.

Therefore, in new buildings, it is important to provide for the possibility of artificial air ventilation, taking into account the multiplicity indicator

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

:

• the purpose of the building;
• the number of electrical appliances installed;
• heat 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 provides for dividing the required amount of clean air entering the building in 1 hour by the volume of the room.

Air exchange rate in administrative and residential buildings

SNiP 2.09.04-87 *

Source: Administrative and domestic buildings SNiP 2.09.04-87 *

5.1. Methodology based on specific air exchange rates

This technique establishes:

- permissible quality of the outside air, determined by the value of the MPC of pollutants in the outside air;

- methods of processing outdoor air, if necessary;

- rates of specific air exchange in residential and public buildings;

- operating modes of ventilation (air conditioning) systems under variable loads and / or with periodic use of premises.

5.1.1. The concentration of harmful substances in the outside (atmospheric) air used for ventilation (air conditioning) should not exceed the MPC in the air of populated areas.

The MPC values ​​should be taken in accordance with GN 2.1.6.1338-03 and GN 2.1.6.1339-03.

The MPC values ​​for pollutants most often present in the air are presented in Table 1.

With the joint presence in the atmospheric air of several harmful substances with the summation of the action, the sum of their relative concentrations, calculated according to the following formula, should not exceed 1:

Here Сi is the concentration i

-th pollutant in the outside air, mg / m3.

5.1.2. If the level of outdoor air pollution exceeds the values ​​given in table 1, it must be cleaned.

In cases where existing cleaning technologies do not allow to ensure the required cleanliness of the outside air, a short-term (for example, during rush hours on highways) reduction in the amount of outside air is allowed.

5.1.3. The room will ensure the permissible air quality if the established norms of specific air exchange are observed (tables 2 and 3).

Notes (edit)

1. If it is known or suspected that unusual pollutants or their sources are present in the room, the amount of air exchange should be established using a methodology based on the calculation of permissible concentrations of pollutants.

2. Tables 2 and show the rates of specific air exchange in m3 / h per person or m3 / h · m2 premises.

In most cases, the amount of pollutants is taken in proportion to the number of people in the room.

In cases where the rates of specific air exchange are presented in m3 / h · m2 and it is known that the number of people in the room differs from the "standard" value, the rates of air exchange per person should be used for the expected number of people in the room.

3. The norms of specific air exchange in tables 2 and for the premises presented in them are established in such a way that when external air of the required quality is supplied, human bio-fluids (solid particles, odors and other pollutants common for the premises presented in them) are diluted and the permissible level is reached indoor air quality.

Comfort criteria (including odor) taking into account bio-efluents are likely to be met if air exchange is sufficient to maintain indoor carbon dioxide concentrations no more than 1250 mg / m3 higher than outdoor carbon dioxide concentrations.

4. The rates of specific air exchange cannot be reduced when using recirculated air.

5. The norms of specific air exchange (table 2 and) determine the need for outdoor air in occupied rooms with air exchange organization schemes that ensure good mixing of air in the room (coefficient of air exchange efficiency Kq = 1).

For circuits with Kq> 1, as a rule, this is possible when air is supplied to the served area of ​​public buildings through floor perforated air diffusers, a methodology based on the calculation of permissible concentrations of pollutants should be applied (see 5.2).

6. A possible scheme for organizing air exchange in an apartment and options for its calculation are presented in Appendix A.

5.1.4. Rooms equipped with exhaust systems (kitchens, bathrooms, toilets, smoking rooms, etc.) can use the air supplied through adjacent rooms to compensate for the exhaust air. The quality of the supply air must meet the requirements of Table 1.

Table 2 - Norms of minimum air exchange in premises of residential buildings1)

Table 3 - Norms of minimum air exchange in public buildings

The supply of outdoor air to the premises is not necessary if the premises are not used and there are no sources of pollution that are not related to the presence of people and their activities (for example, pollution from building materials, furnishings, etc.).

If the pollution of the premises is associated only with the presence of people and their activities, which do not pose a health hazard in a short time, then the supply of outdoor air may lag behind in time from the beginning of the use of the premises.

The lag time, the time lag can be determined from the graph in Figure 1.

Figure 1 - Maximum allowable ventilation lag time Example - Air consumption - 60 m3 / h · person; room volume - 30 m3 / person; permissible ventilation lag time - 0.6 h

5.1.7. If the pollution of the premises is associated with the presence of pollution sources in it that are not related to the presence of people and their activities, the supply of outdoor air must precede the start of use of the premises.

The start time of the outdoor air supply can be determined from the graph in Figure 2.

Figure 2 - Minimum required ventilation time before filling the room Example - Air consumption - 30 m3 / h · person; room volume - 3.5 m3 / person; admissible ventilation lag time - 0.5 h

5.1.8. If the maximum pollution of the room lasts less than 3 hours during the working day, the outdoor air consumption can be determined by the average amount of pollution, but not less than half of the maximum value.

Air exchange rate in healthcare institutions

Source: Manual for the design of healthcare institutions (to SNiP 2.08.02-89)

Normative references

This standard uses references to the following normative documents:

GOST 30494-96 Residential and public buildings. Indoor microclimate parameters

SNiP 2.08.02-89 * Public buildings and structures

SNiP 31-01-2003 Residential apartment buildings

SNiP 31-05-2003 Public buildings for administrative purposes

SNiP 41-01-2003 Heating, ventilation and air conditioning

MGSN 3.01-01 Residential buildings

SanPiN 2.1.6.1032-01 Hygienic requirements for ensuring the quality of atmospheric air in populated areas

GN 2.1.6.014-94 Maximum permissible concentration (MPC) of polychlorinated dibenzodioxins and polychlorinated dibenzofurans in the air of populated areas

GN 2.1.6.1338-03 Maximum permissible concentration (MPC) of pollutants in the air of populated areas

GN 2.1.6.1339-03 Approximate safe exposure levels (TSEL) of pollutants in the air of populated areas

GN 2.1.6.2177-07 Maximum permissible concentrations (MPC) of microorganisms-producers, bacterial preparations and their components in the air of populated areas

NM 113-91 Recommendations for the application of regulatory requirements in the design of heating, ventilation and air conditioning systems for buildings for various purposes

NRB-99 Radiation Safety Standards

TR AVOK-4-2004 Technical recommendations for organizing air exchange in apartments of a multi-storey residential building

ASHRAE 62-1999 Ventilation for acceptable indoor air quality

DIN EN 13779: 2007 Ventilation for non-residential buildings - Performance requirements for ventilation and room-conditioning systems

DIN EN 15251: 2007 Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics , lighting and acoustics)

CIBSE Guide A: 2006 Environmental design. Ch. 1. Environmental criteria for design

Air exchange rate in the premises of preschool organizations

Source: Sanitary and Epidemiological Rules and Norms SanPiN 2.4.1.3049-13. Appendix 3

Terms and Definitions

The following terms and definitions are used in this standard:
3.1. bioefluents

: Contaminants from people, pets, birds, etc., such as odor, carbon dioxide, skin debris, hair, etc.

3.2. ventilation

: Organized air exchange in the premises to ensure the microclimate parameters and air purity in the serviced area of ​​the premises within the permissible limits.

3.3. natural ventilation

: Organized exchange of air in rooms under the influence of thermal (gravitational) and / or wind pressure.

3.4. mechanical ventilation (artificial)

: Organized exchange of air in rooms under the influence of pressure generated by fans.

3.5. outdoor air

: Atmospheric air taken in by the ventilation or air conditioning system for supply to the manned room and / or entering the manned room by infiltration.

3.6. supply air

: Air supplied to the room by the ventilation or air conditioning system and entering the manned room due to infiltration.

3.6. evacuated air

(outgoing): Air taken from a room and no longer used in it.

3.7. harmful (polluting) substances

: Substances for which the maximum permissible concentration (MPC) has been established by the sanitary and epidemiological authorities.

3.8. harmful discharge

: Streams of heat, moisture, pollutants entering the room and negatively affecting the parameters of the microclimate and air purity.

3.10. permissible indoor air quality (air purity)

: Composition of air in which, as determined by the competent authorities, the concentration of known pollutants does not exceed the MPC and to which more than 80% of exposed people have no claims.

3.11. permissible microclimate parameters

: Combinations of values ​​of microclimate indicators, which, with prolonged and systematic exposure to a person, can cause a general and local feeling of discomfort, moderate tension of thermoregulatory mechanisms that do not cause damage or health disorders.

3.12. smell

: A sensation that occurs when gases, liquids or particles in the air affect the receptors of the nasal mucosa.

3.13. infiltration

: Unorganized flow of air into the room through leaks in the building envelopes under the influence of thermal and / or wind pressure and / or due to the operation of mechanical ventilation.

3.14. concentration

: The ratio of the amount (weight, volume, etc.) of one component to the amount (weight, volume, etc.) of the mixture of components.

3.15. place of permanent residence of people in the room

: A place where people stay for more than 2 hours continuously.

3.16. microorganisms

: Bacteria, fungi and unicellular organisms.

3.17. room microclimate

: The state of the indoor environment of a room, characterized by the following indicators: air temperature, radiation temperature, movement speed and relative humidity in the room.

3.18. served area (habitat)

: The space in the room, limited by planes parallel to the fences, at a height of 0.1 and 2.0 m above the floor level, but not closer than 1.0 m from the ceiling with ceiling heating; at a distance of 0.5 m from the inner surfaces of external walls, windows and heating appliances; at a distance of 1.0 m from the distributing surface of the air distributors.

3.19. local suction

: A device for capturing harmful and explosive gases, dust, aerosols and vapors at the places of their formation, connected to the air ducts of local ventilation systems and, as a rule, is a part of technological equipment.

3.20. air cleaning

: Removal of pollutants from the air.

3.21. room free of emissions of harmful substances

: A room in which harmful substances are released into the air in quantities that do not create concentrations exceeding the MPC in the air of the served area.

3.22. room with permanent residence of people

: A room in which people are at least 2 hours continuously or 6 hours in total during the day.

3.23. premises with a mass stay of people

: Premises (halls and foyers of theaters, cinemas, meeting rooms, conferences, lecture halls, restaurants, lobbies, checkout rooms, production halls, etc.) with a permanent or temporary stay of people (except for emergencies) numbering more than 1 person. per 1 m2 of premises with an area of ​​50 m2 or more.

3.24. air recirculation

: Mixing room air with outdoor air and supplying this mixture to this or other rooms.