Natural ventilation system with thin microperforated panel (MPP) component for wideband sound insulation

Abstract

Natural ventilation system plays a pivotal role in building sustainability. However, the design is challenging due to the conflict between opening area requirements and sound insulation capability. Here, we design and experimentally demonstrated such a system with attenuation and bandwidth enhancement. For this, we use MPP components in L-shaped cavity that can be tuned at the targeted frequency range individually, while its overall thickness is reduced due to the benefit of the L-shape that forms a coiled backing air cavity. Moreover, adopting the MPP components allow the system to be easily tuned at various frequency regimes under fixed thickness, particularly at a low frequency that might be difficult for the porous liner cases. It is found that sound insulation bandwidth of 1000 Hz and more can be produced by such a system where the transmission loss of 20 dB and above are pronounced. Most of the features in the theoretical calculation are also found in the experimental results for the same structures. The results are promising for green building applications where sound insulation and air circulation need to be present simultaneously from the natural ventilation system.