The study's results indicated that the SenseAir S8 sensors exhibited a higher agreement with each other and with reference instruments than the Sensirion SCD sensors.

With most individuals spending approximately 90% of their time indoors, the measurement of indoor air quality (IAQ) is essential for health and wellbeing.

Poor IAQ has been linked to various health issues, including respiratory infections and heart disease, underscoring the importance of effective monitoring.

A recent study evaluated the performance of 87 low-cost IAQ monitors, focusing on their ability to measure key indicators such as total volatile organic compounds (tVOCs), particulate matter 2.5 (PM2.5), and carbon dioxide (CO2).

While CO2, temperature, and humidity sensors generally met manufacturer specifications, tVOC sensors exhibited significant accuracy issues, deviating by as much as 79% from reference measurements.

PM2.5 sensors showed consistency but had an error margin of ±27%, which is higher than the stated ±15% accuracy.

The study highlights the necessity for experimental evaluations of low-cost IAQ monitors before they are deployed in the field to ensure their reliability.

The research discussed various CO2 measurement methods, including estimated CO2 through tVOC sensors, NDIR sensors, and photo-acoustic sensors.

Both NDIR and photo-acoustic sensors utilize the gas absorption principle, measuring CO2 by detecting specific wavelengths of light absorbed by different gases.

Among the findings, NDIR sensors like the SenseAir S8 demonstrated better correlation with reference instruments outdoors compared to photo-acoustic sensors from Sensirion.

However, estimating CO2 through tVOC sensors, such as the Sensirion SGP30, is considered unreliable due to interference from other indoor organic components.

Despite their affordability and real-time data collection capabilities, low-cost IAQ monitors raise concerns regarding their accuracy and reliability compared to professional-grade instruments.