Air Sense: Internet of Things-enabled Novel Power Efficient Indoor Air Quality Monitoring System

Air pollution, known to cause health issues such as respiratory and cardiovascular diseases emphasize the importance of monitoring indoor air quality with carbon dioxide (CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) sensor. Despite various air quality monitoring systems being discussed in the literature, their power consumption is often overlooked. This paper introduces Internet of Things (IoT) enabled novel power efficient indoor air quality monitoring system that uses CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, temperature and humidity sensors which send data to the cloud via Global System for Mobile Communication (GSM) technology. Moreover, keeping CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> levels below 1000 PPM is vital for optimal indoor air quality as discussed in literature. The CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> sensor operates continuously, while the temperature and humidity sensor activates when the CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> level becomes equal or exceeds 1000 PPM. By combining temperature and humidity data with CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> levels, a more thorough insight into air quality is achieved. This strategy will reduce the power consumption of the device as both the sensors are active when there is a critical need of monitoring. The system’s battery life is approximately 9.71 days when CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> sensor is active only, decreasing to 8.71 days when both sensors are active using a $15600 \mathrm{mAh} / 4.2 \mathrm{~V}$ battery. Furthermore, the sensor’s fetching interval is set to 15 min when CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> values are unstable. However, when CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> values remain stable, the fetching interval starts at 15 min and doubles with each successive stage of continued stability. This approach minimizes the device’s power consumption by reducing the frequency of data collection.