VENTILATION AND INDOOR AIR-QUALITY IN FINNISH DAY-CARE-CENTERS

The purpose of this study was to assess the performance of ventilation and the indoor air quality in Finnish daycare centers and to evaluate the effect of ventilation and building design on indoor air quality. A random sample of 30 daycare centers in the city of Espoo (part of the Helsinki metropolitan area) was selected for the study. The measurements during October and November 1990 consisted of air flows, temperature, relative humidity, concentrations Of CO2, VOC and formaldehyde, and odor intensity. The measurement period was one day. The air flows in the children's rooms varied remarkably, the range being 0-11 L/s per person (average 3.8 L/s per person). Only 30% of the rooms achieved the Finnish guide value of 5 L/s per person. The air temperature varied from 19-degrees-C to 26-degrees-C (average 22.2-degrees-C). The carbon dioxide concentration measured when the room was occupied varied from 400 to 2500 muL/L (average 810 muL/L). On average, the CO2 concentration was statistically significantly higher in the older daycare centers (constructed before 1981) with mechanical exhaust than in the newer buildings (constructed from 1981 onward) with balanced mechanical ventilation. Correspondingly, the air flows and temperatures were significantly lower on average. The workers were asked to state their experience of poor indoor air quality during the past twelve months; the most common perception was unpleasant odors (60%). Water damage and moisture problems were also common in the daycare centers (70%). The results indicate that there is much room for improvement in the indoor air quality of daycare centers.