IoT-Based Indoor Air Quality Monitoring System Using Arduino

Introduction

The IoT-Based Indoor Air Quality Monitoring System using Arduino is an advanced system designed to continuously monitor indoor air pollution levels. By integrating sensors, Arduino, and IoT connectivity, this system ensures real-time air quality analysis and alerts users when pollution levels exceed safe limits.

Components Used

• Arduino Uno – The core microcontroller for processing sensor data
• MQ135 Gas Sensor – Detects air pollutants like CO2, NH3, and benzene
• DHT11/DHT22 Sensor – Measures temperature and humidity
• WiFi Module (ESP8266/NodeMCU) – Enables wireless data transmission
• OLED/LCD Display – Displays real-time air quality data
• Buzzer or LED Alert System – Notifies users of poor air quality
• IoT Platform (Thingspeak/Blynk/Firebase) – Cloud storage and data visualization

Working Principle

The system continuously monitors air quality using the MQ135 gas sensor and DHT11 sensor. When pollutants exceed predefined levels, the Arduino processes the data and triggers an alert via:

• Buzzer or LED indicators
• WiFi-based notifications to a mobile app or web dashboard
• Cloud storage for historical analysis and trend monitoring

Key Features

✔️ Real-time Air Quality Monitoring – Instant detection of harmful gases and pollutants
✔️ IoT Integration – Remote monitoring via smartphones and web applications
✔️ Data Logging & Analysis – Stores historical air quality data for trends
✔️ Threshold Alerts – Immediate notifications when air quality drops
✔️ Compact & Energy-Efficient – Suitable for 24/7 operation

Applications

✅ Smart Homes & Offices – Ensures a healthy indoor environment
✅ Hospitals & Laboratories – Maintains sterile and safe air conditions
✅ Industrial & Commercial Spaces – Prevents exposure to harmful gases
✅ Schools & Public Buildings – Enhances air quality for better health

This IoT-Based Indoor Air Quality Monitoring System is a cost-effective and efficient solution to track air pollution and maintain a healthy indoor atmosphere.