Acoustic Natural Ventilation Openings - OVNA : How to get rid of the impossible choice between too much heat inside or too much noise !

Due to global warming, summer comfort in buildings is a prime issue, and so is indoor air quality. Natural ventilation is encouraged by "low-carbon" approaches to cool the buildings and reduce air-conditioning. However, remaining free constructible areas in dense cities are mainly noisy, and the inhabitants should not be forced to choose between too much heat inside or too much noise ! The first step is to anticipate buildings' façades " eligibility for natural ventilation through opened windows ", depending on their exposure to the forecoming noise sources. Since 2015 LASA has been carrying R&D on " Acoustic Natural Ventilation Openings - OVNAs" which aims to bring great amounts of fresh air in the buildings, for cooling and ventilate them without allowing noise inside ! It implies to develop accurate exposure models for "noise peaks" which cause sleep or work disturbances, and anticipate the required noise reductions for each windows. On the basis of this work, and an ongoing PhD at LASA, we seized the opportunity to build two OVNA prototypes and to carry out listening sessions and acoustic/thermal measurements. Theses experiments have enabled LASA to confirm the OVNA's performances (sound attenuation, etc.) and improve the modelisation and assessing methods.