Marc Rehfeld

Multiple window glass having thermal and acoustical insulating properties

The invention relates to a multiple window glass comprising a first laminated glass plate and a second simple or laminated glass plate, parallel to the first and separated from it by a gas layer, the two plates being held together in a gastight manner. The resin of the laminated glass of the first plate (1) is chosen so that a bar 9 cm long and 3 cm wide, consisting of a laminated glass comprising two glass sheets 4 mm thick joined by a 2 mm layer of this resin, has a critical frequency that differs at most 35% from that of a glass bar having the same length, same width and 4 mm thickness.

Acoustic insulating box

In order to improve an acoustic insulation performance of a box with parallel faces such as an insulating glazing, the box is equipped with a waveguide. Preferably, the waveguide is situated at the periphery and communicates with the gap of the box via localized orifices situated on each of the sides.

Acoustic behavior of triple glazings

Making of triple glazings is the only way to still improve thermal performances of Insulating Glass Units. Possible ways with double glazings are already in use: increase the space between glasses, use low emissivity coatings and special gas with lower thermal conductivity as argon or krypton. Specific acoustic weak point of double glazings is the resonance between the two panes which works as a mass spring mass system, and coupling of eigenmodes of panes through the air (gas) cavity. These phenomena are of course still more important with triple glazings, as there are two resonances. The paper will give all comparative data concerning thermal and acoustic performances, and describe a way to achieve the same single number values of sound transmission loss with triple glazing that with double glazing by adding absorption in the gas cavities.

Handling of uncertainties for CE marking concerning Sound Transmission Loss of glazings

A joint working group between CEN TC 126 (building acoustics) and CEN TC 129 (glass in building) has been created to handle the redaction of a test code, (give rules for CE marking) and particularly handle uncertainty problems. A round robin has been organised, at which 23 European labs have participated, and two configuration of double glazings have been tested: one with two monolithic glass components, the other with one monolithic and one highly damped laminate component. The paper will present the specifications and main results of this round robin, the questions that occurred concerning the possible ways to decrease uncertainty values, as well as the conclusions and decisions of the working group.