What does CO2 buildup indicate in enclosed spaces?

CO2 buildup in enclosed spaces is often an indicator of poor ventilation. When a space is poorly ventilated, the air exchange rate is inadequate to remove carbon dioxide generated by occupants, activities, and equipment. As people breathe, they exhale CO2, and without sufficient airflow to replace the used air with fresh air from outside, the concentration of carbon dioxide increases. This can lead to discomfort, poor cognitive function, and health issues over time.

High levels of humidity, the presence of mold, and excessive heating may occur simultaneously in poorly ventilated areas but they are not directly indicated by CO2 levels. For example, high humidity can be a separate issue related to moisture sources without being tied to CO2 levels, while mold growth is more often linked to moisture problems rather than CO2 accumulation directly. Additionally, excessive heating might lead to discomfort but does not inherently affect CO2 levels. Thus, recognizing CO2 buildup is a fundamental sign of inadequate ventilation, which is crucial in maintaining a healthy indoor environment.