Russian Ministry of Health
Moscow
1. Developed by the Research Institute of Occupational Medicine of the Russian Academy of Sciences (Suvorov G.A., Shkarinov L.N., Prokopenko L.V., Kravchenko O.K.), Moscow Research Institute of Hygiene. F.F. Erisman (Karagodina I.L., Smirnova T.G.).
2. Approved and put into effect by the Decree of the State Committee for Sanitary and Epidemiological Supervision of Russia dated October 31, 1996 N 36.
3. Introduced instead of "Sanitary norms for permissible noise levels at workplaces" N 3223-85, "Sanitary norms for permissible noise in the premises of residential and public buildings and on the territory of residential development" N 3077-84, "Hygienic recommendations for establishing noise levels at workers places, taking into account the intensity and severity of labor "N 2411-81.
APPROVED
Decree of the State Committee for Sanitary and Epidemiological Supervision
Russia dated October 31, 1996 N 36
Date of introduction since approval
1. Scope and general provisions
1.1. These sanitary norms establish the classification of noise; normalized parameters and maximum permissible noise levels at workplaces, permissible noise levels in the premises of residential, public buildings and in residential areas.
1.2. Sanitary standards are mandatory for all organizations and legal entities on the territory of the Russian Federation, regardless of the form of ownership, subordination and affiliation, and individuals, regardless of citizenship.
1.3. References and requirements of sanitary standards should be taken into account in the State standards and in all regulatory and technical documents regulating planning, design, technological, certification, operational requirements for production facilities, residential, public buildings, technological, engineering, sanitary equipment and machines, vehicles, household appliances.
1.4. Responsibility for fulfilling the requirements of the Sanitary Norms is assigned in the manner prescribed by law to the heads and officials of enterprises, institutions and organizations, as well as citizens.
1.5. Control over the implementation of the Sanitary Standards is carried out by the bodies and institutions of the State Sanitary and Epidemiological Supervision of Russia in accordance with the Law of the RSFSR "On the Sanitary and Epidemiological Welfare of the Population" dated April 19, 1991 and taking into account the requirements of the current sanitary rules and norms.
1.6. Measurement and hygienic assessment of noise, as well as preventive measures should be carried out in accordance with the guideline 2.2.4 / 2.1.8-96 "Hygienic assessment of the physical factors of the production and environment" (under approval).
1.7. With the approval of these sanitary standards, the “Sanitary standards for permissible noise levels at workplaces” N 3223-85, “Sanitary standards for permissible noise in the premises of residential and public buildings and on the territory of residential development” N 3077-84, “Hygienic recommendations for setting levels noise at workplaces, taking into account the intensity and severity of labor "N 2411-81.
2.1. Law of the RSFSR "On the sanitary and epidemiological well-being of the population" dated 19.04.91.
2.2. Law of the Russian Federation "On Environmental Protection" dated 12/19/91.
2.3. Law of the Russian Federation "On Protection of Consumer Rights" dated 07.02.92.
2.4. Law of the Russian Federation "On certification of products and services" dated 10.06.93.
2.5. "Regulations on the procedure for the development, approval, publication, enforcement of federal, republican and local sanitary rules, as well as on the procedure for the operation of all-Union sanitary rules on the territory of the RSFSR", approved by Resolution of the Council of Ministers of the RSFSR of 01.07.91 N 375.
2.6. Decree of the State Committee for Sanitary and Epidemiological Supervision of Russia "Regulations on the procedure for issuing hygienic certificates for products" dated 05.01.93 N 1.
3. Terms and definitions
3.1. Sound pressure is a variable component of air or gas pressure resulting from sound vibrations, Pa.
3.2. Equivalent / energy / sound level, LA.eq., dBA, intermittent noise - the sound level of constant broadband noise, which has the same RMS sound pressure as this intermittent noise for a certain period of time.
3.3. The maximum permissible level (MPL) of noise is the level of a factor that, during daily (except weekends) work, but not more than 40 hours a week during the entire working experience, should not cause diseases or deviations in the state of health detected by modern research methods in in the process of work or in the remote periods of life of the present and subsequent generations. Compliance with the noise limit does not exclude health problems in hypersensitive individuals.
3.4. The permissible noise level is the level that does not cause significant concern to a person and significant changes in the indicators of the functional state of noise-sensitive systems and analyzers.
3.5. Maximum sound level, LА.max., dBA - the sound level corresponding to the maximum indicator of a measuring, direct-reading instrument (sound level meter) during visual reading, or the sound level value exceeded for 1% of the measurement time during registration by an automatic device.
4. Classification of noise affecting a person
4.1. According to the nature of the noise spectrum, there are:
- broadband noise with a continuous spectrum more than 1 octave wide;
- tonal noise, in the spectrum of which there are pronounced tones. The tonal nature of the noise for practical purposes is established by measuring in 1/3 octave frequency bands by exceeding the level in one band over the neighboring ones by at least 10 dB.
4.2. According to the temporal characteristics of noise, there are:
- constant noise, the sound level of which during an 8-hour working day or during the measurement time in the premises of residential and public buildings, on the territory of residential development changes in time by no more than 5 dBA when measured on the time characteristic of the sound level meter “slowly”;
- intermittent noise, the level of which during an 8-hour working day, work shift or during measurements in the premises of residential and public buildings, on the territory of residential development changes over time by more than 5 dBA when measured on the time characteristic of the sound level meter "slowly".
4.3. Intermittent noises are divided into:
- time-varying noise, the sound level of which changes continuously over time;
- intermittent noise, the sound level of which changes stepwise (by 5 dBA or more), and the duration of the intervals during which the level remains constant is 1 s or more;
- impulse noise consisting of one or more audio signals, each with a duration of less than 1 s, while the sound levels in dBAI and dBA, measured respectively on the “impulse” and “slow” time characteristics, differ by at least 7 dB.
5. Normalized parameters and maximum permissible noise levels at workplaces
5.1. Characteristics of constant noise at workplaces are sound pressure levels in dB in octave bands with geometric mean frequencies of 31.5; 63; 125; 250; 500; 1000; 2000; 4000; 8000 Hz, determined by the formula:
Where P is the root mean square value of sound pressure, Pa;
P0 is the initial value of the sound pressure in the air equal to 2 10-5Pa.
5.1.1. It is allowed to take as a characteristic of constant broadband noise at workplaces the sound level in dBA, measured on the “slow” time characteristic of the sound level meter, determined by the formula:
Where RA is the root mean square value of the sound pressure, taking into account the correction "A" of the sound level meter, Pa.
5.2. A characteristic of intermittent noise at workplaces is the equivalent (in terms of energy) sound level in dBA.
5.3. Maximum permissible sound levels and equivalent sound levels at workplaces, taking into account the intensity and severity of work.
A quantitative assessment of the severity and intensity of the labor process should be carried out in accordance with Guideline 2.2.013-94 "Hygienic criteria for assessing working conditions in terms of harmfulness and danger of factors in the working environment, severity, intensity of the labor process."
6. Rated parameters and permissible noise levels in the premises of residential, public buildings and residential areas
6.1. Normalized constant noise parameters are sound pressure levels L, dB, in octave bands with geometric mean frequencies: 31.5; 63; 125; 250; 500; 1000; 2000; 4000; 8000 Hz. For an approximate assessment, it is allowed to use sound levels LA, dBA.
6.2. The normalized parameters of intermittent noise are equivalent (in terms of energy) sound levels LAeq, dBA, and maximum sound levels LAmax, dBA.
Evaluation of intermittent noise for compliance with permissible levels should be carried out simultaneously on the equivalent and maximum sound levels. Exceeding one of the indicators should be considered as non-compliance with these sanitary standards.
6.3. Permissible values of sound pressure levels in octave frequency bands, equivalent and maximum sound levels of penetrating noise in the premises of residential and public buildings and noise in residential areas.
Bibliography
- Guideline 2.2.4 / 2.1.8.000-95 "Hygienic assessment of the physical factors of the production and environment."
- Guideline 2.2.013-94 "Hygienic criteria for assessing working conditions in terms of harmfulness and danger of factors in the working environment, severity, intensity of the labor process."
- Suvorov G. A., Denisov E. I., Shkarinov L. N. Hygienic regulation of industrial noise and vibrations. — M.: Medicine, 1984. — 240 p.
- Suvorov G. A., Prokopenko L. V., Yakimova L. D. Noise and health (environmental and hygienic problems). - M: Soyuz, 1996. - 150 p.
- Permissible levels of noise, vibration and sound insulation requirements in residential and public buildings. MGSN 2.04.97 (Moscow city building codes). - M., 1997. - 37 p.
Our website is our calling card. As on the business card, we displayed only the most necessary, in our opinion, information.
Our website was created so that by visiting here you can call us:
- boiler rooms, boiler equipment, heating boilers, burners
- gas limits
And get qualified answers to your questions in a reasonable time.
Works performed:
- Obtaining technical specifications (TU) for the following types of work: gasification of the facility, water supply, electricity supply, sewerage. And also - all permits for boiler plants in the SES, the Fire Service and other organizations. Gas limits - preparation of documentation, receipt.
- Design of boiler rooms. It is carried out as a separate service, and in the complex of works on the construction of turnkey boiler houses. For gas boilers, diesel boilers and wood-fired boilers. Design is being carried out for the following facilities - gas boilers, diesel boilers and wood waste boilers.
- Boiler equipment . Supply of imported and Russian equipment - directly through manufacturers. We provide discounts to design and installation organizations that make purchases through our representative offices. Main boiler equipment: block modules, boilers, burners, heat exchangers, chimneys.
You can also separately order the following boiler equipment:
- gas boilers (small and medium power),
- heating boilers,
- burners (gas, diesel and combined),
- block-modular buildings (from sandwich panels).
- Installation of boiler rooms is produced both at the Customer's site, and with the possibility of partial execution on the basis of the company, with further delivery to the site and block assembly. Main types: block, modular boiler rooms, roof, built-in, attached, transportable.
- Delivery of completed works. Performing all work on paperwork and interaction with representatives of supervisory authorities. Interaction with all structures involved in both steam boilers and hot water boilers.
Advantages:
- Terms, quality, price- declare everything. Not everyone complies. We comply.
- The management department will deliver to you maximum convenience when working with us.
Boiler houses are designed and installed in accordance with a number of rules, for example:
- GOST 21.606-95 SPDS "Rules for the implementation of working documentation for thermal mechanical solutions for boiler rooms"
- GOST 21563-93 Hot water boilers. Main parameters and technical requirements
- PU and BE "Rules for the design and safe operation of steam boilers"
- PB 12-529-03 "Safety Rules for Gas Distribution and Gas Consumption Systems".
If you have a task to get a valid object by the beginning of the heating season we offer you the option "Block-modular boiler house" based on standard solutions. Modular boiler houses supplied under this program have the following advantages: a) the use of a standard project reduces the time for designing and coordinating the project, b) it becomes possible to purchase the main equipment in parallel with the development of individual parts of the project.
We also translate steam boilers in hot water mode. With this operation steam boilers lose from the rated power, while solving certain heating problems. These are solutions mainly for Russian boilers. The advantage of this operation is that existing steam boilers do not have to be replaced with new ones, which can be beneficial in the short term from an economic point of view.
All supplied boiler equipment is certified and has permissions for use on the territory of the Russian Federation - gas boilers, heating boilers, burners, heat exchangers, valves etc. The specified documentation is included in the scope of delivery.
1. Architectural planning
Functional zoning of the territory of the settlement;
Rational planning of the territory of the residential area - the use of the shielding effect of residential and public buildings located in close proximity to the noise source. At the same time, the internal layout of the building should ensure that the sleeping and other rooms of the residential area of the apartment are oriented to the silent side, and the rooms in which the person stays for a short time - kitchens, bathrooms, stairwells should be oriented towards the highway;
Creation of conditions for the continuous movement of vehicles by organizing traffic without traffic lights (traffic interchanges at different levels, underground pedestrian crossings, allocation of one-way streets);
Creation of bypass roads for transit transport;
Landscaping of the residential area.
2. Technological
Modernization of vehicles (reduction of engine noise, running gear, etc.);
The use of engineering screens - laying a highway or railway in a recess, creating screen walls from various wall structures;
Reducing the penetration of noise through the window openings of residential and public buildings (the use of soundproofing materials - sealing gaskets made of sponge rubber in the window porches, installation of windows with triple bindings).
3. Administrative and organizational
State supervision over the technical condition of vehicles (monitoring compliance with the terms of maintenance, mandatory regular technical inspections);
Monitoring the condition of the roadway.
TESTS
CHOOSE ALL CORRECT ANSWERS
1. WHEN SELECTING A LAND PLOT FOR DEVELOPING A SETTLEMENT, YOU SHOULD CONSIDER
1) terrain
3) the presence of water and green areas
4) the nature of the soil
5) population
2. BASIC REQUIREMENTS FOR THE PLANNING OF A SETTLEMENT
1) placement of functional zones on the ground, taking into account the wind rose
2) the presence of functional zoning of the territory
3) ensuring a sufficient level of insolation of the territory
4) providing convenient ways of communication between separate parts of the city
5) the presence of a sufficient number of high-rise buildings
3. THE FOLLOWING ZONES ARE ALLOCATED ON THE CITY TERRITORY
1) residential
2) industrial
3) utility warehouse
4) central
5) suburban
4. TYPES OF PLANNING OF SETTLEMENTS
1) perimeter
2) lowercase
3) mixed
4) gossamer
5) free
5. THE FOLLOWING REQUIREMENTS FOR THE LOCATION OF THE INDUSTRIAL ZONE
1) take into account the wind rose
2) organize a sanitary protection zone
3) take into account the terrain
4) take into account the population
5) located below the city along the river
6. IN THE RESIDENTIAL ZONE PLACE
1) residential areas
2) trading warehouses
3) administrative center
4) car parks
5) forest park zone
7. THE MOST IMPORTANT HYGIENIC BASIS OF URBAN PLANNING IN OUR COUNTRY ARE
1) the state of the territory for the location of the settlement
2) limiting the growth of large and super-large cities
3) the possibility of landscaping
4) functional zoning of the city
5) use of natural and climatic factors
8. SUBURBAN ZONE IS NECESSARY FOR
1) location of industrial enterprises
2) recreation of the population
3) placement of public utilities
4) organization of the forest park zone
5) placement of transport nodes
9. The type of development of the settlement is determined
1) terrain
2) wind regime of the territory
3) population
4) the presence of green spaces
5) the location of roads
10. THE DISADVANTAGE OF THE PERIMETER DEVELOPMENT IS
1) the difficulty of providing good conditions for insolation of dwellings
2) the complexity of organizing the ventilation of the territory
3) inconvenience to the population
4) difficulty with the organization of the inner territory of the microdistrict
5) inability to use in large cities
STANDARDS OF ANSWERS
1. 1), 2), 3), 4)
3. 1), 2), 3), 5)
7. 1), 3), 4), 5)
9. 1), 2), 4), 5)
HOME HYGIENE
According to WHO experts, a person spends more than 80% of his time in non-production premises. This suggests that the quality of the internal environment of the premises, including the environment of the dwelling, can affect human health. Hygienic requirements for housing are regulated by SanPiN 2.1.2.2645-10 Sanitary and epidemiological requirements for living conditions in residential buildings and premises; SanPiN 2.2.1./2.1.1.2585-10, amend. and additional No. 1 to SanPiN 2.2.1/2.1.1.1278-03 Hygienic requirements for natural, artificial and combined lighting of residential and public buildings.
Ph.D. L.V. Rodionov, Head of Research Support Department; Ph.D. S.A. Gafurov, senior researcher; Ph.D. V.S. Melentiev, Senior Researcher; Ph.D. A.S. Gvozdev, Samara National Research University named after Academician S.P. Koroleva, Samara
To provide hot water and heating for modern apartment buildings (MKD), rooftop boilers are sometimes included in projects. This solution is in some cases cost-effective. At the same time, often, when installing boilers on foundations, proper vibration isolation is not provided. As a result, residents of the upper floors are subject to constant noise exposure.
According to the sanitary standards in force in Russia, the sound pressure level in residential premises should not exceed 40 dBA - during the day and 30 dBA - at night (dBA - acoustic decibel, a unit of noise level, taking into account human perception of sound. - Approx. ed.).
Specialists from the Institute of Machine Acoustics at the Samara State Aerospace University (IAM at SSAU) measured the sound pressure level in the living quarters of an apartment located under the roof boiler house of a residential building. It turned out that the equipment of the rooftop boiler house was the source of the noise. Despite the fact that this apartment is separated from the roof boiler room by a technical floor, according to the results of measurements, an excess of daily sanitary standards was recorded, both in terms of the equivalent level and at an octave frequency of 63 Hz (Fig. 1).
The measurements were taken in the daytime. At night, the operating mode of the boiler room practically does not change, and the background noise level may be lower. Since it turned out that the “problem” is already present during the day, it was decided not to carry out measurements at night.
Picture 1 . The level of sound pressure in the apartment in comparison with sanitary standards.
Noise and vibration source localization
To more accurately determine the “problem” frequency, sound pressure levels were measured in the apartment, boiler room and on the technical floor in different operating modes of the equipment.
The most characteristic operating mode of the equipment, in which a tonal frequency appears in the low-frequency region, is the simultaneous operation of three boilers (Fig. 2). It is known that the frequency of working processes of boilers (burning inside) is quite low and falls in the range of 30-70 Hz.
Figure 2. Sound pressure level in different rooms when three boilers are operating simultaneously
From fig. 2 shows that the frequency of 50 Hz dominates in all measured spectra. Thus, boilers make the main contribution to the spectra of sound pressure levels in the premises under study.
The level of background noise in the apartment does not change much when the boiler equipment is turned on (except for the frequency of 50 Hz), so we can conclude that the sound insulation of the two floors that separate the boiler room from the living rooms is sufficient to reduce the level of airborne noise produced by the boiler equipment to sanitary standards. Therefore, one should look for other (not direct) ways of noise (vibration) propagation. It is likely that the high sound pressure level at 50 Hz is due to structure-borne noise.
In order to localize the source of structural noise in residential premises, as well as to identify vibration propagation paths, additional measurements of vibration acceleration were carried out in the boiler room, on the technical floor, as well as in the living room of the apartment on the top floor.
The measurements were carried out at various operating modes of the boiler equipment. On fig. Figure 3 shows the vibration acceleration spectra for the mode in which all three boilers operate.
Based on the results of the measurements, the following conclusions were made:
- in the apartment on the top floor under the boiler room, sanitary standards are not met;
- the main source of increased noise in residential premises is the working process of combustion in boilers. The prevailing harmonic in the noise and vibration spectra is the frequency of 50 Hz.
- the lack of proper vibration isolation of the boiler from the foundation leads to the transmission of structural noise to the floor and walls of the boiler room. Vibration spreads both through the boiler supports and through pipes with transmission from them to the walls, as well as the floor, i.e. in places of rigid connection.
- Measures should be developed to combat noise and vibration in the path of their propagation from the boiler.
a) 
b) 
in) 
Figure 3 . Vibration acceleration spectra: a - on the support and foundation of the boiler, on the floor of the boiler room; b - on the support of the boiler exhaust pipe and on the floor near the boiler exhaust pipe; c - on the wall of the boiler room, on the wall of the technical floor and in the living room of the apartment.
Development of a vibration protection system
Based on a preliminary analysis of the mass distribution of the structure of the gas boiler and equipment, cable vibration isolators VMT-120 and VMT-60 with a nominal load per vibration isolator (VI) of 120 and 60 kg, respectively, were selected for the project. The scheme of the vibration isolator is shown in fig. four.
Figure 4 3D model of a cable vibration isolator of the TDC model range.
Figure 5 Schemes for fixing vibration isolators: a) support; b) suspended; c) lateral.
Three variants of the scheme for fixing vibration isolators have been developed: support, suspension and side (Fig. 5).
Calculations have shown that the side scheme of the installation can be implemented using 33 VMT-120 vibration isolators (for each boiler), which is not economically feasible. In addition, very serious welding work is expected.
When implementing a suspended scheme, the entire structure becomes more complicated, since it is necessary to weld wide and rather long corners to the boiler frame, which will also be welded from several profiles (to provide the necessary mounting surface).
In addition, the technology of installing the boiler frame on these skids with VI is complicated (it is inconvenient to fix the VI, it is inconvenient to place and center the boiler, etc.). Another disadvantage of such a scheme is the free movement of the boiler in lateral directions (swinging in the transverse plane on the VI). The number of vibration isolators VMT-120 for this scheme is 14.
The frequency of the vibration protection system (VZS) is about 8.2 Hz.
The third, most promising and technologically simpler option is with a standard reference circuit. It will require 18 VMT-120 vibration isolators.
The calculated frequency of the VZS is 4.3 Hz. In addition, the design of the VIs themselves (part of the cable rings is located at an angle) and their competent placement along the perimeter (Fig. 6), makes it possible to perceive with such a scheme a lateral load, the value of which will be about 60 kgf for each VI, while the vertical load on each VI is about 160 kgf.
Figure 6 Placement of vibration isolators on the frame with a reference scheme.
Vibration protection system design
Based on the data of the conducted static tests and the dynamic calculation of the VI parameters, a vibration protection system for the boiler house of a residential building was developed (Fig. 7).
The object of vibration protection includes three boilers of the same design 1 installed on concrete foundations with metal ties; piping system 2 for the supply of cold and the removal of heated water, as well as the removal of combustion products; pipe system 3 for supplying gas to the burners of the boilers.
The created vibration protection system includes external vibration protection supports for boilers 4 designed to support pipelines 2 ; internal vibration protection belt of boilers 5 designed to isolate the vibration of boilers from the floor; external anti-vibration supports 6 for gas pipes 3.
Figure 7 General view of the boiler house with the vibration protection system installed.
The main design parameters of the vibration protection system:
1. The height from the floor to which it is necessary to raise the load-bearing frames of the boilers is 2 cm (installation tolerance minus 5 mm).
2. The number of vibration isolators per one boiler: 19 VMT-120 (18 in the inner belt bearing the weight of the boiler, and 1 on the external support for damping vibrations of the water pipeline), as well as 2 VMT-60 vibration isolators on external supports - for vibration protection of the gas pipeline.
3. The “support” type loading scheme works in compression, providing good vibration isolation. The natural frequency of the system is in the range of 5.1-7.9 Hz, which provides effective vibration protection in the region above 10 Hz.
4. The damping coefficient of the vibration protection system is 0.4-0.5, which provides gain at resonance of no more than 2.6 (oscillation amplitude no more than 1 mm with an input signal amplitude of 0.4 mm).
5. To adjust the horizontal position of the boilers on the sides of the boiler in the U-shaped profiles, there are nine seats for vibration isolators of the same type. Only five are nominally installed.
During installation, it is possible to place the vibration isolators in any order in any of the nine places provided to achieve the alignment of the center of mass of the boiler and the center of rigidity of the vibration protection system.
6. Advantages of the developed anti-vibration system: simplicity of design and installation, insignificant amount of boilers lifting above the floor, good damping characteristics of the system, possibility of adjustment.
The effect of using the developed vibration protection system
With the introduction of the developed vibration protection system, the sound pressure level in the living quarters of the apartments on the upper floors decreased to an acceptable level (Fig. 8) . The measurements were also made at night.
From the graph in Fig. 8 it can be seen that in the normalized frequency range and in terms of the equivalent sound level, sanitary standards in the living room are met.
The efficiency of the developed vibration protection system when measured in a residential area at a frequency of 50 Hz is 26.5 dB, and 15 dBA in terms of the equivalent sound level (Fig. 9).
Figure 8 . The level of sound pressure in the apartment in comparison with sanitary standards, taking into account developed vibration protection system.
Figure 9 Sound pressure level in one-third octave frequency bands in a residential area when three boilers are operating simultaneously.
Conclusion
The created vibration protection system makes it possible to protect a residential building equipped with a rooftop boiler from vibrations generated by the operation of gas boilers, as well as to ensure normal vibration mode of operation for the gas equipment itself, together with the piping system, increasing the service life and reducing the likelihood of accidents.
The main advantages of the developed vibration protection system are simplicity of design and installation, low cost in comparison with other types of vibration isolators, resistance to temperatures and pollution, a small amount of boiler elevation above the floor, good damping characteristics of the system, and the ability to adjust.
The vibration protection system prevents the spread of structural noise from the equipment of the roof boiler through the building structure, thereby reducing the sound pressure level in residential premises to an acceptable level.
Literature
1. Igolkin, A.A. Reducing noise in a residential area through the use of vibration isolators [Text] / A.A. Igolkin, L.V. Rodionov, E.V. Chess // Security in the technosphere. No. 4. 2008. S. 40-43.
2. SN 2.2.4 / 2.1.8.562-96 "Noise at workplaces, in the premises of residential, public buildings and on the territory of residential development", 1996, 8 p.
3. GOST 23337-78 “Noise. Methods for measuring noise in a residential area and in residential and public buildings”, 1978, 18 p.
4. Shakhmatov, E.V. A comprehensive solution to the problems of vibroacoustics of mechanical engineering and aerospace products [Text] / E.V. Chess // LAP LAMBERT Academic Publishing GmbH&CO.KG. 2012. 81 p.
From the editor. On October 27, 2017, Rospotrebnadzor published information on its official website "On the impact of physical factors, including noise, on public health", in which he notes that in the structure of citizens' complaints about various physical factors, the largest share (over 60%) is made up of complaints about noise. The main ones are residents' complaints, including acoustic discomfort from ventilation systems and refrigeration equipment, noise and vibration during the operation of heating equipment.
The reasons for the increased noise level generated by these sources are the insufficiency of noise protection measures at the design stage, the installation of equipment with deviation from design solutions without assessing the generated noise and vibration levels, the unsatisfactory implementation of noise protection measures at the commissioning stage, the placement of equipment not provided for by the project, and also unsatisfactory control over the operation of equipment.
The Federal Service for Supervision of Consumer Rights Protection and Human Welfare draws the attention of citizens that under the adverse effects of physical factors, incl. noise, you should contact the territorial Office of Rospotrebnadzor for the subject of the Russian Federation.
To eliminate each of these noises, different methods are required. In addition, each type of noise has its own properties and parameters, and they must be taken into account when manufacturing low-noise refrigeration chillers.
You can apply a large amount of different insulation and not achieve the desired result, but on the contrary, using the minimum amount of the “right” material in the right place, using insulation according to the technology, achieve excellent low noise.
To understand the essence of the soundproofing process, let's turn to the main methods for achieving low-noise industrial water coolers.
First you need to define the basic terms.
Noise — undesirable, unfavorable for the target human activity within the radius of its propagation sound.
Sound — wave propagation of particles oscillating due to external influence in some medium - solid, liquid or gaseous.
There are other less common and significantly more expensive and cumbersome solutions to achieve near-absolute silence, if required by the chiller installation site. For example, sound insulation of the technical room where the compressor-evaporative unit of the chiller is located, the use of water condensers or wet cooling towers without the use of fans, and some other more exotic ones, but they are rarely used in practice.
