The Influence of Seasonality on Indoor Environmental Quality Parameters in Brazilian University Classrooms

Indoor environmental quality is a key factor in ensuring the well-being, comfort, and optimal performance of activities carried out by occupants. In classroom environments, where high levels of concentration must be maintained for extended periods, indoor conditions play a significantly more critical role. In this context, it is relevant to investigate indoor environmental conditions, as people spend a significant amount of time indoors. Indoor conditions can change significantly throughout the year, and these changes, often caused by the seasons, directly impact the well-being, learning capacity, and satisfaction of those who use the indoor space. This study analyzed classrooms at a university in southern Brazil to understand how the environment changes across summer, autumn, winter, and spring and how these changes can affect students. A one-way analysis of variance (ANOVA) was used to determine whether there were significant differences across seasons throughout the year. To perform this research, a set of 100 data points was collected between March 2024 and June 2025 using the Aura IEQ Discoverer® equipment. These results showed a variation in operative temperature of approximately 9.5 °C between seasonal averages, with summer reaching 25.74 ± 1.17 °C and winter reaching 19.04 ± 3.47 °C. CO2 concentrations remained stable at around 1000 ppm in all seasons (p = 0.786). Volatile Organic Compounds (VOCs) varied significantly (p < 0.001), reaching lower levels in winter (34.24 ± 13.44) than in autumn (65.59 ± 23.34). Therefore, proposals to adjust ventilation, optimize lighting, reduce pollutants, and control noise apply to specific seasonal strategies. These results can help create building management policies that provide greater comfort for users, save energy, and maintain air quality, contributing to healthier, more sustainable educational spaces for the development of activities.