New group of products – Acoustic double glazed units

The construction of glass which protects against noise that accompanies us in large human settlements or indeed everywhere that has a high level of urbanisation is one of the most important, as well as one of the most difficult aspects for consideration when using glazed units in windows, facades and interior walls. This is because the sound heard by man is a wave which is composed of many frequencies. As the human ear, depending on the frequencies receives the sound of the same intensity at varying levels, then noise is not equally damaging for a person in terms of the whole frequency wave. In order to match the appropriate glazed unit it is vital to have knowledge about the precise type of noise (intensity, frequency) which will be present in the area where the glass is to be installed, as well as the level of sound absorption the glass portrays in a given area of frequency.
On this basis it is possible to analyse noise and match the glazed units which reduce the noise levels at frequency levels of the greatest intensity, taking account of the varying sensitivities of the human ear. In order to explicitly define the level of sound absorption in terms of the glass, it is necessary to run laboratory tests. Such tests should be carried out in renowned research institutes which assure the fulfilment of all conditions laid out by certifying institutes. Firms which produce windows, facades as well as glass partitions should receive documentation confirming the Rw (dBA) heat transfer co-efficient, as well as the corrective heat transfer co-efficients C and Ctr (dBA) from the supplier of glass. Press-Glas company in its efforts to assure the best parameters of production as regards glazed units had tests carried out on its series of sound absorptive glass units in the IFT institute of Rosenheim and received a value of Rw at the levels of 34, 36,38,39,40,42 and 51 (dBA). Press-Glas in making the choice of glass units to be tested, set itself the aim of fulfilling the requirements of its clients. The clients of Press-Glas company had the possibility of presenting their expectations by filling in a specially prepared and distributed survey.

The main additional requirements set out by clients as regards sound absorptive glass units were as follows:

• the best possible thermal protection,
• the absence of heavy gases such as SF6,
• the limitation of the width with regard to the glass units.

Press-Glas company fulfilled all of these requirements. The glass units that were tested were made with spacerbars measuring 16mm and filled with noble gas (argon), while one of the glass panes used had a low-emission coating. Only the glazed glass with a Rw = 51 (dBA) heat transfer co-efficient was made on the basis of frames measuring 20mm. On the basis of the results achieved from tests on low emission glass (Top-Glas) with a float construction of 4/16 Argon/Thermofloat 4mm and a heat transfer coefficient of U (W/m2K), it is possible to ensure that single chamber glass that has in its construction spacerbars measuring 16mm, Thermofloat glass 1.1 with a minimal thickness of 4mm, as well as the interior being filled with argon, has the heat transfer coefficient of U=1.1 W/m2K.
Due to its acoustic features the protective layer glass of USG 44.1, 44.2, 44.4, 66.2 with acoustic or ordinary PVB foil was taken into consideration for tests.
Glass units with enhanced sound absorptive features that are produced by Press-Glas are therefore an attractive product for clients for many reasons:

• they are low-emission glass units which have a heat transfer co-efficient of U=1.1 W/m2K for units with spacerbars of 16mm, as well as in similar fashion 1.1 for glass units with spacerbars of 20mm which ensure the following aspects:
• economizing on heat energy,
• lower heating costs,
• optimum temperature in a room,
• they are glass units which can temporarily protect against burglary with a resistance class against blows of P1A, P2A, P4A depending on the construction of glass,
• unlike older glass constructions they do not contain heavy gases like SF6 and therefore do not damage the natural environment,
• they are glass units which ensure efficient reduction of ultra-violet transmission.

Press-Glas possesses certification of tests for all types of sound absorptive glass produced. These tests are carried out in the IFT institute of Rosenheim and are in accordance with the requirements set out for glass units in the norms of EN 20140-3:1995-01, as well as EN ISO 717-1:1996-12.
The clients of Press-Glas company can utilize these tests certificates both in Poland and abroad- in countries where the afore-mentioned norms are obligatory.

The construction and indicators of sound absorptive glass produced by Press-Glas is confirmed
by the Certification of the IFT Research Institute of Rosenheim.