"Sound insulation of offices"

One of the major factors having negative effect on nervous system, is acoustic and vibrating effects. Being accumulated in an organism, acoustic irritations lead to the weariness, the raised blood ressure, drowsiness, nervousness and other, more serious consequences.

Therefore sound insulation of office buildings and premises - an actual problem of modern building. We will notice, that various public institutions concern office spaces, scientific and business centres not only representations of the companies, but also. In premises such simultaneously there is a considerable quantity of people and working office equipment that means rather rigid requests to a microclimate, fire safety and, of course, sound insulation.

Until recently in Russia not enough attention was given to acoustics of premises. It has been connected not only with economy of means, but also with absence of certain acoustic norms. Now the specifications regulating requests to sound insulation, Sanitary norms SN 2.2.4/2.1.8.562-96"Noise on jobs, in premises of inhabited, public buildings and in housing estate territory" are SNiP 23-03-2003 "Protection against noise", and also. In 1997 to use in capital the Moscow building norms of 2.04-97"Admissible noise levels, vibrations and requests to sound insulation in inhabited and public buildings" in which the admissible noise level is established within 13-51 dB have been accepted. Now at building and the further furnish of premises necessity of protection against noise is necessarily considered.

There are some ways of decrease in noise level to office spaces to comprehensible significances. On the one hand, efforts should be directed on removal of external sources of noise, especially if the building facade as it often happens, leaves on brisk street. In such cases the good decision is application of modern window profiles with two-three-chambered double-glazed windows and sound insulation of external walls by plates with various napolnitelyami (stone cotton wool, glassy).

On the other hand, it is necessary to supervise and sources of noise in offices is every possible office and household office equipment, beginning from computers, printers, faxes and finishing conditioners (for this reason manufacturers office and home appliances more and more attention give the last time to issue of quiet models). Sound insulation in office spaces is Besides, necessary.

Effective protection of premises against noise assumes use of the special materials which structure promotes absorption or easing of sound fluctuations of various frequencies and intensity.

The materials applied to protection against noise in designs of buildings are subdivided on sound-proof, called to extinguish the reflected sound fluctuations in premises, and soundproofing, intended for application as linings under floating floors and in multilayered protecting designs for the purpose of improvement of isolation from the shock and air noise extending through walls, partitions, etc.

Sound-proof materials are applied basically in designs of sound-proof facings of internal surfaces of premises and the technical systems requiring decrease of level of noise (ventilation and air conditioning installation, etc.), and also to improvement of acoustic properties of premises (auditoriums, audiences and so forth).

From the acoustic point of view sound absorbers can be divided into following groups:

• Porous (including fibrous);
• Porous with the punched screens;
• The resonant;
• Layered designs;
• Piece or volume.

Because of ease in installation porous sound absorbers produce the most widespread in the form of plates which fasten to vertical or horizontal surfaces is direct or on otnose, from easy and porous mineral piece materials - pumice, vermikulita, kaolina, slags, etc. with cement or other knitting structure. Such materials are strong enough, and foyers, ladder marches of buildings can be used for noise decrease in corridors.

Efficiency of sound-proof materials is evaluated by the factor of the sound absorption equal to the relation of quantity of absorbed energy to total of energy falling on a material of sound waves.

The choice of a concrete material depends on an acoustic mode, appointment and architectural features of a premise. In premises where to appearance of sound absorbers increased requirements are presented, apply in special way processed fibrous materials. As raw materials for their production wood and mineral fibres, glass cotton wool, synthetic fibres serve. These items also produce in the form of flat plates (ceiling or stenovyie panels) or curvilinear and volume elements.

Most effectively protection of office against noise is carried out by means of modern teplozvukoizolyatsionnyih materials. Such materials happen as a natural origin (an item on the basis of stone cotton wool, kaolinovaya cotton wool, vspuchennyiy perlit, cellulose cotton wool, floor-mats from a linen tow, pith sheet), and synthetic (penopoliestr, penopoliuretan, expanded polystyrene and so forth).

Basically, all transferred materials are recommended for use as sound insulation of office spaces. But it would be desirable to stay on some nuances.

Still more recently pith cover was very widely applied in quality zvukoizolyatora. However, according to experts, actually the stopper is effective only against so-called "shock noise" (resulting mechanical effect on elements of building designs), and has no universal sound-proof characteristics.

The same concerns also the various synthetic made foam materials. They are attractive enough from the point of view of simplicity of use, but in the majority do not meet modern requests to sound insulation of public buildings, but also, frequently mismatch requests of fire safety.

Therefore now on the foreground there are universal sound-proof materials on the basis of natural raw materials, for example, items on the basis of stone cotton wool. Their excellent sound-proof properties are defined by specific structure - chaotically directed most thin fibres at a friction the friend about the friend transform energy of sound fluctuations into the thermal. Application of such heaters considerably reduces risk of occurrence of vertical sound waves between wall surfaces, reducing reverberation time, and, thereby, reducing sound level in the next premises.

The basic zones of application of acoustic materials - external walls, intraoffice partitions, and also ceilings and floors. We will consider the most widespread methods of sound insulation of office spaces.

External walls

In the Russian climatic conditions the thermal protection of external walls is priority. But, as it has already been indicated, fibrous teploizolyatsionnyie materials simultaneously are and zvukoipoglotitelyami. Therefore many actions directed on a thermal protection of external walls, simultaneously improve also their acoustic characteristics.

For teplozvukoizolyatsii external walls plates with various porous or fibrous napolnitelyami are applied. Are Most effective plitnyie zvukoizolyatoryi from fibrous materials. In particular, isolation on the basis of stone cotton wool is successfully applied in the multilayered designs which sound-proof qualities it is repeatedly better, rather than a monolithic wall. The design consists of sheets of different materials between which there is an air cavity. In such structure of vibration fade more fast, than in a homogeneous material.

Often enough offices place in old buildings, in which designs because of a deterioration very bad sound insulation. In such cases at building reconstruction front systems of "wet" type can be used.

The system of "wet" type represents a classical example of a two-layer acoustic design. The protecting design from the point of view of sound fluctuations is two-layer: both covers of a design at sound excitation fluctuate independently one from other and are connected among themselves only izolyatsionnyimi by materials of insignificant rigidity. For facades of buildings with a thin plaster layer front system ROCKFACADE can be used.

Intraoffice partitions

The same principle of multilayered designs is applicable and for internal walls and partitions in office spaces, with that only a difference, that here the loads which are not exceeding a body weight of a design act on soundproofing designs. Furthermore, here on the foreground leave ecological compatibility and pozharobezopasnost applied materials. In connection with these requests application of nonflammable fibrous materials is reasonable.

The typical easy partition with good acoustic properties looks as a sandwich in which fibrous zvukoizolyator it is concluded between two gipsokartonnyimi sheets (or other sheet material). In quality zvukoizolyatora it is possible to use both stone cotton wool, and glass wool.

More difficult designs of partitions, for example, with repeated alternation of layers of gypsum cardboard and zvukoizolyatora, or even an air layer between two layers of a sound-proof material are possible also. Multilayered designs of partitions are, of course, more expensive and are difficult in installation, but supply the greatest possible sound insulation.

For maintenance of good sound insulation between partition premises it is impossible opirat on pure floors or logs, and it is necessary to establish directly on an overlapping plate. And, to bring to nothing probability of occurrence of resonant fluctuations, a partition do not lead up to a ceiling on 15-20 mm, filling in the remained backlash an elastic sound-proof material. Same "pillow" should be provided and in the area of a partition support on a floor.

Ceilings

Traditionally as the basic sound-proof design the pendant acoustic ceiling is used. Such designs are rather useful in the big office spaces divided into individual jobs (kubiklyi) by easy partitions, not reaching a ceiling.

Acoustic ceilings are produced of stone cotton wool, fiber glass, and also from plaster, metal, drevesnovolokonnyih materials. Also there are the false ceilings revetted from a face sheet with an aluminium film and specially processed internal surface, a dust preventing hit.

Floor

For today the effective remedy of struggle against shock noise is application of a design of a "floating" floor. Designs concern this type of overlappings with a continuous elastic layer between a floor both a bearing ferro-concrete plate and a design with a floor on soft and elastic linings.

The material and thickness of plates for application in soundproofing designs steals up on the basis of the given acoustic characteristics of plates. Thus variety of requests as in such designs materials are exposed to the raised loads should be considered. The most important parametres here is a durability on compression and small degree of deformation.

Also fire-prevention characteristics of materials as under fire protection regulations at furnish of ways of evacuation (corridors) nonflammable materials can be used only are not less important also. These requests are answered completely with rigid plates from stone cotton wool (for example, FLORAE BATTS, specially developed for creation of acoustic floating floors).

It is necessary to notice, that the last years in Russia appears more and more office buildings in which modern materials are applied to creation of soundproofing designs. So, it is possible to result a number of examples of office buildings constructed in the most noisy cities of Russia - in Moscow and St.-Petersburg which meet the advanced requests to sound insulation. This building of company "Lukoil", an assurance company “Rosno”, business centres "Berlin house" and "the Petrovsky fort".

Also to the sound insulation factor the big attention is paid at reconstruction of old buildings with alteration under office spaces or repair of already existing offices.

Obviously, employers start to realise that fact, that quality of a work on hand in many respects depends on conditions in which employees work. And in maintenance of psychological comfort and healthy atmosphere sound insulation plays not the last role.

Company ROCKWOOL Russia Press-service