What gas is widely recognized as the best indicator of Indoor Air Quality (IAQ)?

Carbon Dioxide (CO2) is widely recognized as the best indicator of Indoor Air Quality (IAQ) for several reasons. One crucial aspect is that CO2 levels can reflect the concentration of other indoor air pollutants and the effectiveness of ventilation systems. In well-ventilated spaces, CO2 levels remain low, indicating that fresh air is circulating and the potential for airborne contaminants is minimized.

As human beings exhale CO2, the levels of this gas can rise significantly in confined or poorly ventilated areas, signaling that the air quality may be compromised. Elevated CO2 levels are often associated with a higher density of occupants in a space, increased indoor pollutants, and insufficient air exchange rates, making it a practical measure for assessing the need for HVAC adjustments or improvements.

Additionally, carbon dioxide is easy to measure and monitor, which further supports its role as a reliable indicator of indoor air quality. Although other gases like Carbon Monoxide (CO) and Nitrogen Dioxide (NO2) can also affect health and comfort, they are less commonly present in indoor environments compared to CO2. Thus, measuring carbon dioxide provides a clearer understanding of the overall indoor air quality dynamics.