Evaluating Acoustic Comfort in Classrooms equipped with Controlled Mechanical Ventilation: a combined Objective and Subjective Approach

In recent years, increasing attention has been devoted to the acoustic quality of learning environments, as room acoustics signi/icantly in/luence students’ concentration, speech intelligibility, and well-being. Concurrently, the growing implementation of Controlled Mechanical Ventilation (CMV) systems in school buildings to ensure proper air exchange and indoor air quality raises concerns about potential noise emissions and their impact on acoustic comfort. Although classroom acoustics are extensively investigated, research addressing the combined assessment of acoustic parameters and perceived comfort in classrooms equipped with CMV systems remain limited. This study presents preliminary results of an in-/ield acoustic campaign conducted in a Primary School recently retro/itted with a CMV system. The investigation covered two classrooms, representing different spatial con/igurations and occupancy conditions. Acoustic measurements were performed in accordance with UNI 11532-2:2020. Continuous Equivalent Sound Pressure Level (Leq), Reverberation Time (RT), Speech Clarity (C50), and Speech Transmission Index (STI). Subjective perception of acoustic comfort was assessed through questionnaires distributed in multiple scenarios including different seasons and operativity of the CMV. The integrated analysis enabled direct comparison between measured acoustic performance and users’ perceptions, providing insight into the impact of CMV activation on acoustic quality and potential trade-offs between improved air quality and acoustic performance.