Children in kindergartens spend between five and ten hours a day, the quality of air inside is very important. Kindergartens in Poland do not have mechanical ventilation, most often use stack ventilation, which is frequently aided by airing. The main objective of the research was to evaluate the interior conditions, especially with regard to carbon dioxide concentration.

The buildings of various size and different insulation properties of exterior walls were investigated. Their air exchange systems were also organized differently.

This study allowed for a better understanding of the distribution of CO2 concentrations in kindergartens. It was also found that CO2 concentrations were high and exceeded the European standards.

To avoid headaches, fatigue, loss of concentration and other health symptoms among the children attending these kindergartens, a new method of room ventilation was suggested to keep good IAQ.

As the first measurement set had been completed, the staff of the kindergartens were informed about the indoor air quality. Instead of temporary airing with fully opened windows, continuous micro-ventilation was suggested.

The results clearly point to one kindergarten as the one with a properly operating ventilation system and decent indoor air parameters. In the kindergarten, ventilation occurred with only minimum active participation of the personnel: windows did not need to be opened on a regular basis, as air could freely penetrate inside the building through the installed ventilation valves.

After this research had been completed, headmasters confirmed that central heating costs have not risen and the number of children and staff absent because of illness decreased by about 20%.

The present research has resulted in considerable improvement of indoor conditions in the analyzed kindergartens.

The presence of children and ventilation habits seemed to be the main determinants of IAQ and carbon dioxide.

DOI: https://doi.org/10.3846/enviro.2017.022