Ventilation and indoor air quality in newly built school with hybrid ventilation

This paper is a case study of ventilation and indoor air quality (IAQ) investigations in a Finnish comprehensive school with hybrid ventilation system and several reported IAQ problems. The functionality of hybrid ventilation system and perceived and measured IAQ in the classrooms with perceived stuffy air and bad odors were determined. Supply air distribution to classrooms was CO2 controlled. Measurements revealed that supply air flow rate was insufficient, and CO2 concentration or other IAQ measurements were unable to
detect ventilation and IAQ problems, which were caused due to improper operation and guidance system error. Pressure losses in the supply air duct system caused uneven supply air distribution to classrooms. However, results indicate that hybrid ventilation changed to mechanical supply ventilation is able to provide adequate ventilation and IAQ when designed and maintained properly.