Design and Development of a Low-Cost IoT-Based Smart Air Cleaner for Real-Time Indoor Air Quality Control

Abstract

Indoor air pollution presents considerable health concerns, including respiratory disorders and diminished overall well-being. Ensuring a healthy and comfortable indoor environment therefore necessitates continuous monitoring of key parameters such as air quality, temperature, and humidity. This study presents the design and development of a low-cost, portable IoT-based smart air cleaner for HVAC applications, aimed at enhancing indoor air quality through real-time monitoring and automated control. The proposed prototype incorporates a multistage filtration system comprising a True HEPA filter and an activated carbon filter to effectively remove particulate matter (PM2.5 and PM10), dust, and pollen. The system is powered by an Arduino UNO R4 WiFi microcontroller and integrates MQ135 and MQ2 gas sensors, a DHT11 temperature and humidity sensor, PIR motion sensors, and a two-channel relay module to automatically regulate a DC fan and UV-C LED light. Remote monitoring and system control are enabled via the Blynk mobile platform. The development process involved a comprehensive literature review, mechanical design using CREO, 3D printing, hardware integration, and embedded programming. Experimental results demonstrate accurate real-time measurements of PM2.5, PM10, AQI, temperature, and humidity, with a minimum percentage error of 0.76%. Future enhancements may include the adoption of higher-precision sensors, improved energy efficiency strategies, and integration with centralized HVAC systems for large-scale deployment. Overall, the proposed system provides a compact, automated, and cost-effective solution for improving indoor air quality, health, and occupant comfort in residential environments.