Indoor air quality in kindergartens: the relationship between environmental parameters and levels of occupation of spaces

Abstract

School buildings are spaces with specific characteristics where the guarantee of healthy working conditions are crucial for learning and welfare of the occupants. However, the new architectural standards have enhanced the appearance of buildings more airtight, with reduced ventilation rates and problems related to indoor air quality (IAQ). With the new regulation were adopted reference values for chemical and microbiological parameters. The concentration of CO2 and microorganisms can give a good indication of the efficiency of ventilation. In this context, was carried out a study which aims was to correlate the concentrations of CO2 and microorganisms with occupant density and efficiency of ventilation in classrooms. The quantification of environmental parameters was based on structural characterization and operation of the building. Samples were taken in Spring in nine classrooms in four kindergartens with different construction types. The results showed that the new kindergartens had average concentrations of CO2 higher than those found in old ones, maximum values around 3400 ppm when in use. The concentrations values of gram positive bacteria in the new kindergartens, which may be related to overcrowding and insufficient ventilation of the spaces. The values of air velocity also showed the air stagnation. The increased of ventilation rates and awareness of occupants are key measures for improving IAQ. However, is in the design phase of the building that should emerge the concerns with IAQ.