A multi-stage analysis of air leakage and acoustic performance on a full-scale test chamber

It is imperative to comprehend the intricate relationship between air infiltration and sound transmission in building systems to optimise energy efficiency and acoustic comfort. This study focuses on measuring the performance of a separating wall between two spaces in terms of sound insulation and airtightness, under different air flow path configurations. Airtightness and sound insulation measurements were made on a test sample wall mounted in an accredited sound insulation facility, while subsequently increasing the number and size of artificially drilled openings. The diameter of these apertures ranged from 0.67 to 7.09 cm, with the total area of the apertures varying up to 39.50 cm 2 . The variation in diameter and the total number of apertures had a dual impact: it affected airtightness and the flow regime and energy dissipation within the apertures, which in turn may affect sound insulation. The acoustic results presented an unexpected behaviour: conventional wisdom suggests that increasing the number of openings should lead to a decrease in sound insulation; however, the study observed that adding relatively small holes (0.67/1.4 cm diameter) resulted in constant or less sound transmission. The results suggest that the diameter of holes affects the flow regime, as indicated by the exponent values that characterize flow behavior. Furthermore, these variations influence energy dissipation within the openings, which in turn may impact sound insulation. This observation underscores the intricate interplay between airflow and sound transmission in building systems. Further research is required so that the acoustic firm of cracks can be used to estimate the size of cracks in buildings and to provide a prioritization criterion when undertaking retrofitting. • Multiple small wall openings dissipate sound energy more effectively than a single opening with the same total area. • Introducing small openings in a wall does not necessary decrease sound insulation due to the frictional and viscous effects within the opening. • Acoustic behaviour is affected by opening size, internal surface area and flow regime. • Small opening positions (center or corner) has no significant effect on sound insulation.