Monitoring of air quality as part of the indoor environment quality (IEQ) requires measurement and analysis of various contaminants, which currently depends on onsite sampling of air followed by analysis in the lab with individual instruments. It takes at least one week to get a full report including particle count and microbiological results on the measurement and analysis results. The discontinuity, low efficiency, high cost and inconvenience are some of the obvious disadvantages of the current method.
To enable a healthy indoor environment through real-time monitoring of IEQ, a team comprising researchers from NMC, Institute of Microelectronics (IME) and National University of Singapore looked into the development of 1) an integrated low-cost IEQ sensor to enable real-time IEQ monitoring of fine particle count, CO, CO2, formaldehyde, volatile organic compounds (VOCs) temperature and relative humidity, 2) a high-accuracy multi-Gas Mixing and Characterization system to verify the performance of the proposed IEQ monitoring sensor, and 3) an autonomous sensor calibration and condition monitoring scheme with supporting algorithm to enhance the reliability of networked IEQ sensors.
The project team has developed:
- A novel and low-cost gas sensor using advanced micro-electromechanical and photonic technologies for reliable, accurate and fast monitoring of indoor environmental quality including CO 2, CO, VOCs, particulate matter (PM), temperature and humidity.
- A ppb-level dynamic gas mixing and characterisation system to test the sensors, which is required for validating the performance of the sensors to ensure that they are suitable and reliable for the intended indoor environmental quality parameters.
- A sensor self-diagnostic and self-healing technology for real-time monitoring and calibration of networked sensors.
The developed low-cost and integrated IEQ sensor promotes adoption of large area IEQ monitoring for smart building applications including smart ventilation control for better occupant’s health and building energy efficiency. The multi-gas mixing and characterization system forms a valuable testing platform for certification of commercial air quality sensors and evaluation and product improvement of new air quality sensors in R&D stage. The sensor self-diagnostic and self-healing technology ensures sensor data reliability and would bring significant cost reduction in IEQ sensor network maintenance and re-calibration, which helps lower the adoption barrier of large-scaled IEQ sensor networks for smart building technologies.