Environmental modeling and simulator development for gas sensors and measurement systems

Indoor air pollution increases due to human breath, volatile organic compounds, bacteria etc. in places such as schools, hospitals and offices where people spend most of their time and is rarely felt. For a healthy and comfortable living environment, besides temperature and humidity control, it is necessary to measure the amount of pollutant gases and to perform indoor air conditioning according to measured values. Carbon dioxide (CO2) is an important indoor air pollutant that is recommended for determining ventilation requirements and for control Indoor Air Quality (IAQ). Indoor CO2 concentrations vary linearly with the number of people in a closed environment and the level of activity they perform. In this study, a mathematical model has been developed that that predicts CO2 changes in indoor environments according to physical properties of the environment, the number of people, the characteristics and activities of humans in the environment. This model was then applied to a meeting room in Bilecik Şeyh Edebali University and verified by measurement results. In the second part of the study, the developed model was applied to the naturally ventilated classrooms on the first floor in Faculty Building of Computer and Information Sciences in Sakarya University and IAQ was analyzed for various situations in terms of CO2 gas. In the study, the indoor CO2 concentrations were calculated by considering the number of people in the classrooms on different ventilation and indoor conditions. Then, the results were validated by the measurements. As another output of the measurement studies, the amounts of CO2 in most of the classrooms were observed above the limits in terms of health and comfort conditions. The developed mathematical model can be used in the design phase of new buildings and IAQ analysis of existing buildings. The model is also integrated with a visual interface, and the resulting numerical values can be analyzed by graphical interfaces.