Rice husk panels for building applications: Thermal, acoustic and environmental characterization and comparison with other innovative recycled waste materials

In building applications, recycled waste materials are becoming promising acoustic absorbers and thermal insulating solutions in order to reduce the environmental impact. The aim of the research is to evaluate the thermal, acoustic, and environmental performance of recycled waste panels consisting of rice husk (RH) produced by gluing and pressing the raw material. Its acoustic and thermal performance were compared with the ones of six panels composed by other recycled materials (cork scraps, end-life tires, coffee chaff, waste paper, textile fiber mats, wool fiber scraps), assembled with similar techniques. Thermal resistance of RH is equal to 0.59 m2K/W, in the same order of magnitude of many traditional systems. Sound absorption coefficients were measured by means of the impedance tube. All the panels present acoustic absorption comparable with traditional ones (peak values 0.87-0.99). RH peak value is 0.87, while the maximum values are obtained for cork and wool fiber scraps (1 and 0.97 respectively). Life cycle analysis, performed in compliance with ISO 14040 showed the best environmental performance for the production of 1 m2 of RH and coffee chaff panels. Taking in account their acoustic and thermal behaviour, the wool fiber scraps presents a very good performance.