Bad indoor air quality is dangerous for humans body health because many people tend to do indoor activities so that it makes a house become a micro environment that related to air pollution risk. Therefore, this research has a goal to make an automatic air quality control system that can be online monitored where exhaust fan rotation speed is controlled by exhaust fan switching speed form a few dimmer that has a different power to decrease indoor air pollutant concentration instead. The system has been made, is using MG-811 as CO2 concentration detector placed in the component box and Opto-interrupter sensor to measure exhaust fan airflow rate. The analysis results showed that MG-811 has error average is 0.93% while the accuracy is 99.07% and airflow rate has average error is 1.65% while the accuracy is 98.35%. The experiment result showed that the prototype able to respond the change of CO2 concentration by switching the speed level of the exhaust fan but the monitoring system still has few a data loss because it is disconnected from the surrounding wifi.