Air Quality

Indoor carbon dioxide readings can provide useful information about ventilation when interpreted alongside occupancy and building conditions, but they are not a complete measure of indoor air quality. EPA notes that indoor CO₂ concentrations can provide information about ventilation and should be interpreted carefully. An expert may therefore compare CO₂ trends with occupancy, outdoor-air delivery, HVAC schedules, and other air-quality measurements rather than treating a single concentration as conclusive.

Location, timing, sampling duration, instrument or laboratory method, calibration, detection limits, building occupancy, HVAC operating conditions, weather, and activities occurring during the test can all affect the interpretation of results. An expert can place those variables alongside the alleged exposure period to assess what the data support and identify the limitations of the measurements.

The analysis may consider the contaminant being targeted, filtration or air-cleaning technology, airflow, equipment capacity, placement, operating records, filter condition, and measurements taken before and after use. The central question is whether the equipment and operating conditions were capable of addressing the airborne contaminant at issue, rather than simply whether an air-cleaning device was present.