| Abstract [eng] |
In this master 's thesis, the parameters of thermal comfort and air quality in the classes of two schools were investigated. In the schools built not in the same year and with different ventilation systems, classroom temperature, relative humidity, and CO2 concentration were assessed according to standards and research. In addition, the selected computer science classroom was further investigated for air quality parameters: particulate matter and total volatile organic compounds. Studies in these schools have revealed that the critical parameter indicating poor ventilation is high CO2 concentration. In the school with a natural ventilation the CO2 concentration limit of 1000 ppm exceeded 51% of the time investigated and in the second one with a mixed mechanical ventilation it exceeded 43% of the time. In all classes of the two schools during the cold and warm season, the minimum average temperature described in Lithuanian standards in the work areas was ensured. Relative humidity was also adequate in both schools, except during the cold season when in all classes explored of the school with mechanical ventilation too low relative humidity was recorded. The class with the highest recorded concentration of 3789 ppm CO2 throughout the study was chosen for the numerical modeling. To improve the parameters of air quality and thermal comfort, a CFD model was developed to find out the best combination of heating and ventilation systems for air quality and thermal comfort. The paper examined nine different variants that showed that the level of CO2 concentration and the spread of cross-infection in the classroom is best reduced by a displacement ventilation system. |
