Acoustic and thermal performance of luffa fiber panels for sustainable building applications

Sound-absorbing and thermal-insulating materials have a noteworthy role in the performance of buildings. In recent years, there has been a significant focus on utilizing natural fibers as construction materials for thermal insulation and sound absorption purposes. In this study, luffa, an abundant and eco-friendly natural fiber, was explored as a sustainable material with potential high acoustic and thermal performance due to its intrinsic hollow and sponge-like structure. The experiments were designed using the response surface method based on central composite design (RSM-CCD) to find the best combination of input variables including thickness, density, and binder content for optimal performance. The sound absorption average (SAA) and effective thermal conductivity (Keff) values of the panels ranged from 0.16 to 0.68, and 0.033–0.054 W/(mK), respectively. It was found that both the SAA and Keff are significantly influenced by thickness and density, while binder content does not have a significant effect. The optimal condition for fabricating luffa panels was found to be a thickness of 40 mm, density of 225 kg/m3, and binder content of 7.5 %. Furthermore, the acoustic characteristics of the optimized panels were examined in a conference hall using the Odeon software. The acoustic absorption properties of panels were also predicted using the Johnson–Champoux–Allard and Attenborough models.