Publication

Abstract : Indoor air quality (IAQ) plays a vital role in occupant health, comfort, and cognitive performance, particularly in office environments using ductless split air conditioners that lack fresh air intake. This study presents a cost-effective, IoT-enabled exhaust ventilation system designed to regulate carbon dioxide (CO2) concentrations based on real-time occupancy and sensor feedback. The system, which uses an ESP32 microcontroller interfaced with an MG811 CO2 sensor and a DHT22 temperature sensor, activates ventilation only when CO2 levels exceed 1000 ppm. A two-week experimental study was conducted in a university workspace-one week without the ventilation system and one week with it. Results demonstrated that the system successfully reduced prolonged CO2 exposure, maintained average concentrations near the recommended threshold, and optimized fan operation time for energy efficiency. This solution offers a scalable, automated approach for demand-controlled ventilation in split-AC workspaces, significantly improving IAQ while minimizing energy consumption.