Real Time Indoor Air Quality Monitoring Using Internet of Things at University

The learning environment is one place that requires good air quality because air quality will determine health and learning outcomes. The composition of the gas content in the learning environment needs to be monitored continuously to maintain a healthy body and excellent performance. This study developed an air quality monitoring system in classrooms using Internet of Things technology on wireless LAN (WLAN) networks. The measured air quality is determined by the concentration of O2, CO, CO2 and NH3 gases at multiple measuring points in the classroom. The gas sensor is controlled by Arduino as a processor equipped with a wifi module and a real time clock (RTC). Sensor nodes are activated for 2 minutes to measure and send data and then put to sleep for 5 minutes. This operating mode consumes energy of 3,410 mWh or 42% less than full time operating mode. Data acquisition by each sensor node will be sent to the server using the HTTP protocol and displayed on web pages that can be accessed via the internet in real time. The results showed that the measurement of gas concentration at the sensor node was carried out accurately, real time and synchronously. The delay process for all sensors at each sensor node is about 2 minutes which is used for heating before making measurements.