Noise reduction measures. Protection of residential buildings equipped with a roof boiler from noise and vibration

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 to modern apartment buildings(MKD) projects sometimes include rooftop boilers. 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 upper floors exposed to constant noise.

According to the sanitary standards in force in Russia, the level sound pressure 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 the perception of sound by a person. - 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 sound pressure level in the apartment compared to sanitary standards.

Noise and vibration source localization

For more exact definition“Problem” frequency measurements were made of the sound pressure level 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 various premises when three boilers work at the same time

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 taken on various modes operation of boiler equipment. On fig. Figure 3 shows the vibration acceleration spectra for the mode in which all three boilers operate.

According to the results of the measurements made following conclusions:

- 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 a support exhaust pipe boiler 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 gas boiler and equipment, cable vibration isolators VMT-120 and VMT-60 with a nominal load per one vibration isolator (VI) of 120 and 60 kg, respectively, were selected for the project. The scheme of the vibration isolator is shown in fig. 4.

Figure 4 3D model of cable vibration isolator model range TDC.

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 hanging circuit the whole 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 VI itself (part of the cable rings is located at an angle) and their competent placement along the perimeter (Fig. 6), allows you to perceive with such a scheme a lateral load, the value of which will be about 60 kgf for each VI, while vertical load for 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 form boiler room with installed vibration protection system.

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 an amplification 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 U-shaped profiles, nine seats under 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 roof boiler from vibrations created by the operation of gas boilers, as well as to ensure normal vibration mode of operation for the gas equipment 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 the simplicity of design and installation, low cost in comparison with other types of vibration isolators, resistance to temperatures and pollution, a small amount of rise of the boilers above the floor, good damping characteristics of the system, the possibility of adjustment.

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 residential premises, 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. Complete solution 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 specific gravity(over 60%) are complaints about noise. The main of them are residents' complaints, including acoustic discomfort from ventilation systems and refrigeration equipment, noise and vibration during the operation of heating equipment.

Causes advanced level the noise generated by these sources is the insufficiency of noise protection measures at the design stage, installation of equipment with deviation from design solutions without assessing the generated noise and vibration levels, unsatisfactory implementation of noise protection measures at the commissioning stage, placement of equipment not provided for by the project, as well as unsatisfactory control for the operation of the equipment.

The Federal Service for Supervision of Consumer Rights Protection and Human Welfare draws the attention of citizens to the fact 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.

14. Vibration protection

Permissible sound level A (noise) from equipment installed in heat points or pumping stations

According to PN-87/8-02151/02 p. 3, the sound level A (noise) from pumps or valves, measured at a distance of 1 m from the equipment, should not exceed 65 dB.

In the book " Specifications construction and acceptance of a gas or liquid fuel boiler house”, issued by the Polish Corporation for Sanitary, Heating, Gas Technology and Air Conditioning (Edition II), the permissible sound levels are given:

for boilers with a capacity of 30-120 kW with atmospheric burners - below 65 dB (A);

for boilers with a capacity of 30-120 kW with fan burners - below 85 dB (A);

for boilers with a power of more than 120 kW - not higher than 85 dB (A).

When installing a boiler with a power of less than 30 kW in a separate kitchen, the sound level should not exceed 51 dB (A), and in a kitchen combined with another room - 45 dB (A). The sources on the basis of which these values ​​are given are not known to the authors. Presumably they are quoted from instructions issued by

in Western countries.

AT Due to the fact that the Polish standards do not contain instructions on the values ​​of the sound level, the source of which is the boiler room, lagging behind the changes in the heat engineering market, the authors refer to the German guidelines VDI 2715 regarding the reduction of noise from heating equipment. These instructions comprehensively cover the problems of noise generated by the boiler room.

Despite very strict limits (even below 25 dB(A)) on the noise generated by the boiler room (both the level of sound emitted into the environment and the level of sound penetrating into adjacent rooms), the permissible sound level in the boiler room itself depends from the rated power of the boiler and the installed burner. For boilers with fan burners, its value can be determined by the formula:

Minimum values ​​of the airborne sound insulation index by the overlap between the boiler room

and living quarters

The value of the airborne sound insulation index by the ceiling (taking into account all indirect sound transmission paths) between the boiler room and the apartment premises, in accordance with the PN-B-02151-3 standards of 1999, cannot be less than R'A1 = 55 dB. The value of the index of the reduced level of impact noise penetrating from the floor of the boiler room into the apartments should not exceed L'n.w = 58 dB.

14.4. Noise generated by the boiler-burner group

14.4.1. Influence of boiler power on the level of radiated noise

On fig. 14.4 shows corrected sound levels in dB(A) for boilers of various capacities with fan burners. The graph shows the curves of sound level changes in octave bands depending on the boiler power. The presented characteristics are obtained empirically, as a result of numerous experiments with boiler plants. Of course, deviations can occur and must be taken into account when designing noise protection. RAICHLE data are given.

14. Vibration protection

Rice. 14.4. Distribution of the sound pressure level in octave bands for the “boiler – fan burner” group

different power

14.4.2. Sound level of boilers of various types

AT Currently, more and more often boilers with fan burners are used. There are many factors in favor of such a decision, but, as a rule, it is more decisive high efficiency. In addition to a number of advantages, the “boiler - fan burner” group also has a disadvantage - an increased noise level. The main source of fan burner noise is the turbulence that occurs in the pumped gas. The intensity of this sound is directly proportional to the average speed of the blades to a degree, the value of which is within<5, 6>. The sound intensity is approximately the same both at the suction and discharge of the fan.

According to , the sound power level for fans, determined in half-space, can be roughly calculated using the formula:

14. Vibration protection

With known fan motor power W (kW), the following formulas can be used:

For determining exact values sound power level depending on the type of fan and its operating conditions, you can use the guidelines of VDI 2081.

Sound power levels produced by a fan as a function of flow and pressure difference

∆p , calculated by the formula , are shown in fig. 14.5.

Rice. 14.5. Dependence of fan sound power L N on volume flow and pressure difference ∆p

As can be seen from the graph, the sound power L N is directly proportional to the volume flow at a certain pressure difference ∆p . For comparison, in Fig. 14.6 shows the sound level A only for fan burners of different power. The maximum sound level values ​​for a given boiler power fluctuate in the frequency range from 500 to 2000 Hz. Comparison of graphs in fig. 14.4 and 14.6 allows us to conclude that the sound level of the “boiler-burner” group is not much higher than the sound level of one fan burner. The maximum values ​​of the sound level of the “boiler-burner” group are noted in the lower frequency range of 63-500 Hz. In this case, we are dealing with low-frequency noise.

Simplistically, it can be argued that the boiler affects the structure and level of sound produced by the fan burner, only qualitatively, but not quantitatively.

14. Vibration protection

The studies carried out by the authors showed that the sound values ​​for boilers low power, both with fan and atmospheric burners, are almost the same. Differences in noise emission have been noted for boilers above 100 kW. An increase in sound pressure level is associated with an increase in fan performance.

On fig. 14.6 shows the sound power level A for fan burners depending on the boiler output.

Rice. 14.6. Sound power level A for fan burners depending on boiler output

14.5. Acoustic model of the heating installation

The study of the propagation paths of elastic waves must begin with an analysis of the main acoustic mechanism associated with separate elements heating installation. First you need to localize the sources that generate oscillations and noise. In heating installations, this is the “boiler-burner” group, pumps and valves. Initially, you need to estimate the level of generated noise. Although each of these devices may comply with the regulations in force in this area, the total noise exposure from all equipment often exceeds the allowable values ​​for adjacent rooms or the environment.

The next step is to determine the ways of sound transmission. There are several main sound propagation paths in heating installations. These include pipelines together with the coolant (mainly water), chimneys, ventilation ducts and individual devices that, through points of contact or attachments, participate in the propagation of noise.

The last step is to localize the zones emitting sound. As a result of this analysis, a causal chain of noise generation and propagation has been developed, shown in Fig. 14.7.

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Rice. 14. 7. Causal chain of noise generation and propagation

The noise that occurs in one of the sources propagates further in the form of vibrations of the particles of the medium with which this source is in contact. In a heating installation, sources that generate elastic waves are in contact, in most cases, with matter in all physical states - air, liquid and solid. Therefore, the distribution of emerging fluctuations must be considered for all these three categories.

The general model of the heating installation is shown in fig. 14.8. It is divided into dynamic factors that are actively involved in the process of generating elastic vibrations, and static factors that propagate vibration and noise. Dynamic factors are the main sources of noise listed above: boiler-burner group, pumps and valves.

Static factors include pipelines of heating systems, ventilation ducts, chimneys, housings and casings of equipment, partitions and, of course, the design of the house as a whole.

Depending on the environment in which the generation or propagation of noise occurs, it bears the appropriate name: airborne noise, noise propagating in water, impact noise. As shown in Figure 14.8, not all sources produce elastic waves in all three categories, nor does every medium play a key role in the propagation of noise from a given source. The purpose of extracting noise factors is to identify dominant sources, transmission paths and radiating surfaces.

The end effect of equipment vibration is sounds (noises) that propagate in the airspace and may also cause vibration (oscillations) of partitions and other building structures located in the environment.

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airborne sound

sound propagating in a liquid

Rice. 14.8. Acoustic model of the boiler room and heating system

Noise sources

Noise during the movement of gases (combustion products, air) occurs due to turbulent phenomena, shocks or pulsations. Turbulence is a noise generating mechanism that can take many forms. For example, it may consist of simple background components associated mainly with the outflow of gases from holes, or have a broadband spectrum when they flow through channels with sharp edges, with locking elements or other local resistances.

Stream from high speed, such as at the tip of a fan blade or nozzle, creates turbulence that contributes to noise over a wide sound range. Its level and spectrum depend on the flow velocity, medium viscosity and nozzle geometry.

Fluid, like air, generates noise due to turbulence, pulsations and impacts. The principles listed above apply to liquids as well. In addition, the phenomenon of cavitation may occur in it, when static pressure drops below saturation pressure. The occurrence of cavitation is a phenomenon characteristic of valves and pumps. In the zone of pressure drop below the vapor saturation pressure, cavitation vapor bubbles appear. During recompression, the bubbles burst, creating zones of significant pressure buildup. Due to the fact that re-compression (compression) often occurs in the wall layer of the flow, cavitation is the cause of erosion. Cavitation generates a wide range of noise.

Impact is the cause of structural (impact) noise in the pipelines of the heating system. Most important parameters factors affecting the occurrence of impact noise are the mass and velocity of the particles that collide and the duration of the impact. Frequency analysis of impact shows that high frequencies dominate over broadband noise due to the short duration of the impact itself.

The group "boiler - burner" generates the sound of all the previously listed categories. Sound propagation paths are also different: moving fluid, attachment points, chimneys, cladding and equipment enclosures. The total sound power emitted by the boiler-burner group is the sum of all the above components.

14.6. Noise reduction in the airspace

AT airspace noise penetrates through the supply and exhaust openings. By its nature, the noise has a direction, and its greatest intensity is observed along the channel axis. From this follows the conclusion that

in In the opening, the direction of the noise must be changed, for example by means of a screen, or a sound attenuator must be installed in the opening or duct.

Noise emission from equipment surfaces depends on the size, shape, resilience, mass and sound-absorbing properties of the surface. Therefore, it is desirable that the equipment has compact design, since small dimensions, high rigidity and mass reduce noise emission.

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Airborne noise can be limited by:

soundproof casings;

acoustic screens;

silencers;

sound-absorbing coatings.

Soundproof casing

The concept of a casing means a shell, inside of which there is a noise source (Fig. 14.10). The soundproof cover is passive agent limiting the propagation of noise. Often this is the only way to reduce the noise level from active acoustic sources - moving mechanisms or their parts. The peculiarity of the casing is that the noise level is reduced already in the immediate vicinity of the source. This also protects workplaces located near the noise source.

The casing is made mainly of thin sheet steel. To improve the soundproofing properties, it is covered from the inside with a layer of porous sound-absorbing material. The thickness of the layer of such material depends on the lowest frequency of the sound.

Reducing the transmission of impact noise from the source to the casing occurs due to the use of materials that dampen vibrations in the attachment points.

soundproofing material

Sound absorbing material

Silencer on

vent

Vibration base

Rice. 14.10. Sectional view of the soundproofing hood and example of the soundproofing hood of a Vitoplex burner

Principles for designing shells around sound sources:

dense isolation of the sound source; even small gaps or openings must be closed;

use of metal as soundproofing material from the outer side of the casing;

the use of sound-absorbing material inside the casing;

the use of silencers in ventilation openings, openings for the passage of cables, pipes, etc.;

no rigid connections between the equipment and the casing, reducing the number of attachment points.

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A measure of the effectiveness of a soundproof casing is the soundproofing capacity of the casing D skin - the difference between the average sound pressure level at all measurement points when the mechanism or equipment is running without a casing L m1 (dB) and the average sound pressure level at the same points when the mechanism is running, but already with soundproof casing L m2 (dB) at geometric mean frequencies of octave bands from 63 to 8000 Hz. The value of the soundproofing ability of the casing D of the skin in dB is determined by the formula:

When studying the acoustic efficiency of the casing, it is not necessary to confuse the concepts of the soundproofing ability of the casing and the specific soundproofing capacity of the partition R w , which is determined by the acoustic properties of the elements from which it is made.

Screens can be installed near small pieces of equipment with high level noise emission. Their effectiveness is much lower than the efficiency of soundproof casings and depends on the direction and distance from the noise source. However, screens can be useful for reducing noise in confined areas, such as an operator's station.

The effectiveness of screens is limited to frequencies where the height and length of the screen is the same as or greater than the wavelength of sound transmitted in air.

Screen design principles:

screens are used to protect operator workplaces from noise;

for the manufacture of screens dense soundproof materials are used;

screens from the side of the noise source are covered with a sound-absorbing layer.

Silencers

Silencers are elements that prevent the passage of sound transmitted by air ducts. Absorption silencers are made in the form of a “porous channel”. They are often built into fan shrouds to provide cooling to motors without compromising the effectiveness of the soundproofing properties.

Silencer design principles:

use of absorption silencers to reduce broadband noise;

preventing the speed of the moving medium above 12 m/s in absorption mufflers;

the use of reactive silencers, acting on the principle of reflection to reduce noise at low frequencies;

use of silencers-expanders at the compressed air outlet.

The number of appeals from citizens received by the Office of Rospotrebnadzor in the Tyumen region about the deterioration of living conditions due to exposure to excess noise levels is increasing every year.

In 2013, 362 appeals were received (in total for violations of peace and quiet, accommodation and noise), in 2014 - 416 appeals, in 2015 80 appeals have already been received.

According to the established practice, after the request of residents, the Department appoints measurements of noise and vibration levels in a residential building. If necessary, measurements are carried out in organizations located near apartments, where, for example, “noisy” equipment is used - a source of noise (restaurant, cafe, shop, etc.). If noise and vibration levels are found to exceed the permissible values, in accordance with SN 2.2.4/2.1.8.562-96 "Noise at workplaces, in residential, public buildings and on the territory of residential development", to the owners of noise sources - legal entities, individual entrepreneurs - the Department issues an order to eliminate the identified violations of sanitary legislation.

How can the noise from the equipment listed above be reduced so that there are no complaints from the residents of the house during its operation? Certainly, perfect option- provide necessary measures at the design stage of a residential building, then the development of noise reduction measures is always possible, and their implementation during construction is ten times cheaper than in those houses that have already been built.

The situation is quite different if the building has already been built and there are noise sources in it that exceed the current standards. Then, most often, noisy units are replaced with less noisy ones and measures are taken to isolate the units and the communications leading to them. Next, we will look at specific sources of noise and vibration isolation measures for equipment.

NOISE FROM THE AIR CONDITIONER

The use of three-link vibration isolation, when the air conditioner is installed on the frame through the vibration isolator, and the frame - on reinforced concrete slab through rubber gaskets(in this case, the reinforced concrete slab is installed on spring vibration isolators on the roof of the building), leads to a decrease in penetrating structural noise to levels acceptable in residential premises.

To reduce noise, in addition to strengthening the noise and vibration isolation of the air duct walls and installing a silencer on the air duct of the ventilation unit (from the side of the premises), it is necessary to fasten the expansion chamber and air ducts to the ceiling through vibration isolating hangers or gaskets.

NOISE FROM THE BOILER ROOM ON THE ROOF

To protect against the noise of the boiler house located on the roof of the house, the foundation plate of the roof boiler house is installed on spring vibration isolators or a vibration isolation mat made of special material. The pumps and boiler units equipped in the boiler room are installed on vibration isolators and soft inserts are used.

The pumps in the boiler room must not be placed with the motor downwards! They must be mounted in such a way that the load from the pipelines is not transferred to the pump casing. In addition, the noise level is higher with a higher power pump or if several pumps are installed. To reduce noise, the foundation plate of the boiler room can also be placed on spring dampers or high-strength multilayer rubber and rubber-metal vibration isolators.

The current regulations do not allow the placement of a roof boiler directly on the ceiling of residential premises (the ceiling of a residential premises cannot serve as the base of the boiler room floor), as well as adjacent to residential premises. It is not allowed to design roof boiler houses on the buildings of preschool and school institutions, medical buildings of polyclinics and hospitals with round-the-clock stay of patients, on the sleeping buildings of sanatoriums and recreation facilities. When installing equipment on roofs and ceilings, it is desirable to place it in places farthest from the protected objects.

NOISE FROM INTERNET EQUIPMENT

According to the recommendations for the design of communication systems, informatization and dispatching of housing construction objects, it is recommended to install cellular antenna amplifiers in a metal cabinet with a locking device on technical floors, attics or stairwells of upper floors. If it is necessary to install house amplifiers on different floors multi-storey buildings they should be installed in metal cabinets in close proximity to the riser under the ceiling, usually at a height of at least 2 m from the bottom of the cabinet to the floor.

When installing amplifiers on technical floors and attics to eliminate vibration transmission of a metal cabinet with locking device the latter must be installed on vibration isolators.

OUTPUT - VIBRATION ISOLATORS AND FLOATING FLOORS

For ventilation, refrigeration equipment on the upper, lower and intermediate technical floors of residential buildings, hotels, multifunctional complexes or in the vicinity of noise-rated rooms where people constantly stay, you can install the units on factory vibration isolators on a reinforced concrete slab. This slab is mounted on a vibration-isolated layer or springs on a "floating" floor (an additional reinforced concrete slab on a vibration-isolation layer) in a technical room. It should be noted that fans, outdoor condensing units, which are now produced, are equipped with vibration isolators only at the request of the customer.

"Floating" floors without special vibration isolators can only be used with equipment that has an operating frequency of more than 45-50 Hz. These are, as a rule, small machines, the vibration isolation of which can be provided in other ways. The efficiency of floors on an elastic foundation at such low frequencies is low, therefore they are used exclusively in combination with other types of vibration isolators, which provides high vibration isolation at low frequencies (due to vibration isolators), as well as at medium and high frequencies (due to vibration isolators and a “floating” floor). ).

The floating floor screed must be carefully isolated from the walls and the supporting floor slab, since the formation of even small rigid bridges between them can significantly impair its vibration isolation properties. In places where the "floating" floor adjoins the walls, there must be a seam made of non-hardening materials that does not allow water to pass through.

NOISE FROM THE GARBAGE DUCT

To reduce noise, it is necessary to comply with the requirements of the norms and not design the trunk of the garbage chute adjacent to residential premises. The trunk of the garbage chute should not adjoin or be located in the walls enclosing residential or service premises with normalized noise levels.

The most common measures to reduce noise from garbage chutes are as follows:

• in the premises for collecting garbage, a “floating” floor is provided;
• with the consent of the residents of all apartments in the entrance, the garbage chute is welded (or liquidated) with the placement of wheelchair garbage chambers, concierge rooms, etc. in the room. ( positive moment in that, in addition to noise, odors disappear, the possibility of the appearance of rats and insects, the likelihood of fires, dirt, etc. is eliminated);
• the loading valve bucket is mounted with framed rubber or magnetic seals;
• decorative heat and noise protective lining of the trunk of the garbage chute made of building materials is separated from the building structures of the building with soundproof gaskets.

Today, many construction companies offer their services, various designs to increase the sound insulation of walls and promise complete silence. It should be noted that in fact, no structures can remove structural noise transmitted through the floors, ceilings and walls when dumping municipal solid waste into the garbage chute.

NOISE FROM ELEVATORS

In SP 51.13330.2011 “Noise protection. Updated edition of SNiP 23-03-2003 "says that it is advisable to locate elevator shafts in stairwell between flights of stairs(clause 11.8). In the architectural and planning solution of a residential building, it should be provided that the built-in elevator shaft adjoins premises that do not require increased protection against noise and vibration (halls, corridors, kitchens, sanitary facilities). All elevator shafts, regardless of the planning solution, must be self-supporting and have an independent foundation.

Shafts should be separated from other building structures with an acoustic joint of 40-50 mm or vibration-isolating pads. As the material of the elastic layer, slabs of acoustic mineral wool on a basalt or fiberglass base and various foamed polymeric roll materials are recommended.

To protect against structural noise of an elevator installation, its drive motor with a gearbox and a winch, usually mounted on one common frame, is vibration isolated from the supporting surface. Modern elevator drive units are equipped with appropriate vibration isolators installed under metal frames, on which motors, gearboxes and winches are rigidly mounted, and therefore additional vibration isolation of the drive unit is usually not required. At the same time, it is additionally recommended to make a two-stage (two-link) vibration isolation system by installing the support frame through vibration isolators on a reinforced concrete slab, which is also separated from the floor by vibration isolators.

The operation of elevator winches installed on two-stage vibration isolation systems has shown that the noise levels from them do not exceed standard values in the nearest residential premises (through 1-2 walls). For practical purposes, care must be taken to ensure that vibration isolation is not disturbed by random rigid bridges between the metal frame and the supporting surface. The supply cables must have sufficiently long flexible loops. However, the operation of other elements of elevator installations (control panels, transformers, car and counterweight shoes, etc.) may be accompanied by noise above the normative values.

It is forbidden to design the floor of the elevator engine room as a continuation of the floor slab of the ceiling of the living room of the upper floor.

NOISE FROM TRANSFORMERSUBSTATIONSON THE GROUND FLOOR

To protect against noise transformer substations of residential and other premises with standardized noise levels, the following conditions must be observed:

• premises of built-in transformer substations;
• should not be adjacent to noise-protected rooms;
• built-in transformer substations should
• located in basements or on the first floors of buildings;
• transformers must be installed on vibration isolators designed in an appropriate way;
• electrical panels, containing electromagnetic communication devices, and separately installed oil switches with an electric drive must be mounted on rubber vibration isolators (air disconnectors do not require vibration isolation);
• ventilation devices premises of built-in transformer substations must be equipped with noise suppressors.

To further reduce noise from the built-in transformer substation, it is advisable to process its ceilings and internal walls sound absorbing lining.

In built-in transformer substations, protection against electromagnetic radiation must be made (a grid of special material with grounding to reduce the level of radiation of the electrical component and a steel sheet for magnetic).

NOISE FROM ATTACHED BOILERS,BASEMENT PUMPS AND PIPES

Boiler room equipment (pumps and pipelines, ventilation units, air ducts, gas boilers etc.) should be vibration-isolated using vibration foundations and soft inserts. Ventilation units are equipped with silencers.

To isolate pumps located in basements, elevator nodes in individual heating points (ITP), ventilation units, cold rooms, the specified equipment is installed on vibration foundations. Pipelines and air ducts are vibroisolated from the structures of the house, since the predominant noise in the apartments located above may not be the base noise from the equipment in the basement, but the one that is transmitted to the building envelope through the vibration of pipelines and equipment foundations. It is forbidden to arrange built-in boiler rooms in residential buildings.

In piping systems connected to the pump, it is necessary to use flexible inserts - rubber-fabric sleeves or rubber-fabric sleeves reinforced with metal spirals, depending on the hydraulic pressure in the network, 700-900 mm long. If there are pipe sections between the pump and the flexible connector, the sections should be fixed to the walls and ceilings of the room on vibration-isolating supports, hangers or through shock-absorbing pads. Flexible connectors should be located as close as possible to the pumping unit, both on the discharge line and on the suction line.

To reduce noise and vibration levels in residential buildings from the operation of heat and water supply systems, it is necessary to isolate the distribution pipelines of all systems from the building structures of the building at the points of their passage through bearing structures(input to residential buildings and output from them). The gap between the pipeline and the foundation at the inlet and outlet must be at least 30 mm.

Prepared based on the materials of the journal Sanitary and epidemiological interlocutor (No. 1 (149), 2015

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.

Can apply a large number of different insulation and not achieve desired result, but on the contrary, using the minimum amount of the “right” material in the right place, using insulation according to the technology, to 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, soundproofing 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 others are more exotic, but they are extremely rarely used in practice.

Soundproofing of the boiler room.

Sound insulation of a boiler room. In this publication, we will consider the causes of increased noise and vibration levels from gas boilers and boiler rooms, as well as ways to eliminate them in order to achieve normative indicators and the comfort level of residents.

Installation of autonomous modular gas boilers on the roofs of apartment buildings is becoming increasingly popular among developers. The advantages of such a boiler house are obvious. Among them

No need to build separate building for boiler room equipment

Reduction of heat losses by 20% due to the small number of heating mains in comparison with heating from the central heating network

Savings on the installation of communications from the coolant to the consumer

Absence of necessity forced ventilation

The possibility of full automation of the system with a minimum of staff

One of the disadvantages of a rooftop boiler is vibrations from the boiler and pumps. As a rule, they are the result of shortcomings in the design, construction and installation of boiler room equipment. Therefore, the responsibility for eliminating the increased noise level and soundproofing the boiler room lies with the developer or housing management company.

The noise from the boiler house is low-frequency and is transmitted through the structural elements of the building directly from the source and through communications. Its intensity in a room equipped for a boiler room is 85-90dB. Noise insulation of a rooftop boiler room is justified if it is produced from the source side, and not in the apartment. Soundproofing the ceiling and walls in an apartment with such noise is expensive and ineffective.

Causes of increased noise level in the rooftop boiler room.

Insufficient thickness and massiveness of the base on which the boiler room equipment stands. This leads to the penetration of airborne noise into the apartments through the floor slab and the technical floor.

Lack of proper vibration isolation of the boiler. At the same time, vibrations are transmitted to ceilings and walls, which radiate sound into apartments.

Rigid fastening of pipelines, communications and their supports is also a source of structural noise. Normally, pipes should pass through building envelopes in an elastic sleeve, surrounded by a layer of sound-absorbing material.

Insufficient thickness of the pipeline, as a design error, leading to high water velocity and the creation of an increased level of hydrodynamic noise.

Soundproofing of the rooftop boiler room. List of events.

Installation of vibration isolating supports under the equipment of the boiler room. The calculation of materials for vibration isolation is made taking into account the area of ​​\u200b\u200bthe support and the weight of the equipment;

Elimination of "hard connections" in the places of fastening of pipeline supports with the help of material silomer, thermosound insulation or installation of vibration fasteners on studs fixing communications;

In the absence of elastic sleeves, expansion of the pipeline passage through the supporting structures, wrapping with elastic material (k-flex, vibrostack, etc.) and a heat-resistant layer (basalt cardboard);

Wrapping the pipeline with a material that reduces heat loss and has sound insulation properties: , Texound 2ft AL;

Additional sound insulation of enclosing structures of the roof boiler room;

Installation of rubber compensators to reduce the transmission of vibrations through the pipeline;

Installation of silencers in the exhaust gas duct;

Installation of noise-absorbing materials based on basalt (Stopsound BP) or fiberglass (Acustiline fiber) allows you to reduce background noise in the boiler room by 3-5dB.

SOUND INSULATION OF A BOILER IN A WOODEN HOUSE.

building code rules and fire safety dictate the installation of the boiler in a special room equipped with a separate entrance. As a rule, it is located in the basement or basement. With this arrangement, complaints about an increased noise level from the boiler are rare.

Boiler installed on the same floor as living rooms, which has high noise levels with complete silence in country house may cause inconvenience to residents. Therefore, the soundproofing of the boiler may be relevant.

The reasons for the increased noise level can be similar to those of a rooftop boiler, but on a smaller scale. They also include

Features of the design of the outer box of the boiler. In most models of boilers, the burner and fan are closed with a separate damper, which reduces the noise produced by the burner. If soundproofing protection is only plastic box boiler, the noise from the burner can be noticeable.

Noisy fan from the manufacturer.

Unbalance of the fan, dirt sticking due to dust from outside and neglect of maintenance measures.

Air entering the heating system.

Incorrect gas burner setting.

Rigid system for fastening the boiler and outlet pipes.

The soundproofing of the boiler begins with identifying the causes of the increased noise level and is associated with the work of the gas service employees serving it or the company involved in soundproofing the premises.

If the operation of the boiler and the system is adjusted, then

We mount the boiler on a vibration-isolated platform on mounts with a force meter

We install rubber compensators in the places where the pipes exit from the boiler body