Due to Covid-19, indoor air quality (IAQ) in rooms where many people gather together becomes more important than ever, but the data base is scarce. In this study, IAQ was measured twice in the seminar venue to verify effect of circulation on IAQ. Although the ventilation system was operated at the first seminar, two circulators were operated with the ventilation system at the second seminar. IAQ was continuously measured near the lectern and reception desks using a device which can detect various factors on IAQ. The results indicated that the CO₂ concentration was higher than the standard value during the first seminar but all the IAQ factors were lower than the standard values. Thus, the results suggested that promoting air flow using circulators may improve IAQ.
