Acoustic performance test assessment on sound generated by rainfall on multilayer-etfe-cushion systems

Abstract

Ethylene-tetra-fluor-ethylene (ETFE) membrane structure presents itself as an innovative construction element, taking advantage of its flexibility, lightweight, transparency and thermal insulation properties. However, for large enclosed areas, concerns exist related to the sound insulation characteristic of the system, especially related to the internal noise levels generated during rainfall conditions. Therefore, aiming to both assess the effect of rain noise on these structural elements, as well as generating a clear picture to this condition to designers and clients, Taiyo Europe promoted a measurement campaign on a predefined set of pneumatic ETFE roof elements. The set of pneumatic cushions investigated was produced from the same 250-micron thick ETFE foil. The number of layers, number of air chambers and the level of the pressure inside the cushion was variable, following a carefully predefined test plan. The elements were tested with and without an additional rain suppressor fabric mesh on top of the specimen. The tested elements were installed on a special outdoor structure designed and built for this purpose. This work will describe the tests performed, as well as an assessment of the results achieved and their impact on the design of enclosed buildings cladded with ETFE pneumatic structures.