Prototype Design of Automatic Switching Speed of Exhaust Fan For Indoor Air Quality Control With Warning Alarm System Based on IoT

Indoor air pollution is a major factor affecting human health depending on the air circulation system used. Indoor air pollution can be in the form of CO
2
, Particulate Matter, and TVOC, which can cause fatigue, irritation, acute respiratory infections (ISPA), COPD, and lung cancer. One of the factors that reduce air quality is bad ventilation. Therefore, it is necessary to update the air quality control system. In this study, was made automatic exhaust fan control whose speed can be adjusted according to the concentration of carbon dioxide in the room and equipped with environmental temperature and humidity monitoring. This prototype is also equipped warning alarm system that warns of good to dangerous conditions in the room. From this study, was made automatic on-off control system for switching the exhaust fan speed which is set at each speed level and is able to remove CO
2
gas in the room. Where the carbon dioxide concentration is measured by the NDIR CO
2
sensor which has been validated and is known to have an accuracy value of 99.75% with a repeatability of 2.08. And DHT22 sensor has an accuracy value of 99.67% and repeatability of 0.17 for temperature variables, while the humidity variable has an accuracy value of 98.44% and repeatability of 0.15. The results showed that the exhaust fan speed-switching control system can be used to control indoor air quality. However, to determine air quality, it is necessary to add other variables than carbon dioxide for better room conditions.