Performance Evaluation of the Indoor Air Quality (IAQ) Assessment

Maintaining acceptable indoor air quality (IAQ) has become a public issue, policymakers have had developed strategies to address the performance of it. Pollutant concentrations measured during the occupied period of a space is a key parameter to determine IAQ. Apart from a number of sampling schemes concerning the measurement time of the average pollutant level, an 8-hour continuous measurement has been widely adopted in local IAQ assessments, with a balance of accuracy and measurement effort. It is believed that the longer the measurement time, the higher the accuracy and confidence level of the measurement can be achieved. However, the probable errors of the measurement regarding the measurement periods were not addressed clearly in those assessments. This study, taking a long-term carbon dioxide (CO2) measurement in a typical open-plan office building as a reference, develops a database to examine the probable errors of different sampling schemes. The results show that the probable errors of measurements are correlated with the required measurement time.