Most people spend over 90% of their time indoor, and for some contaminants, exposure to indoor air poses a potentially greater health threat than outdoor air exposure. To improve indoor air quality and to protect public health are important topics in Taiwan. In November 2011, our government promulgated the Indoor Air Quality Management Act, and the EPA has set up a number of auxiliary regulations to better implement the act. Team works are based on article 10 “Indoor Air Quality (IAQ) Act” and article 14 “Indoor Air Quality Testing and Monitoring Management Regulations”, and to study the automatic systems for monitoring indoor air quality. In this project, only the automatic monitoring systems of carbon dioxide (CO2) were evaluated. Total of 18 product samples, sold on the market, were investigated. Reference gases at various concentrations (400~3000 ppm) were used to assess the performances of each sample. The response of all the samples shows good linearity (R2>0.995) with respect to gas concentration. In addition, all samples were placed in a cleanroom, capable of controlling the confounding factors including temperature, humidity, particle and carbon dioxide concentrations. After adjusting environmental conditions, the readings of product samples and reference instrument were recorded. The discrepancies between the product samples and reference instrument were evaluated under the same environmental conditions. Some product samples were found to have high sensitivity and accuracy. These products may be good for monitoring carbon dioxide concentration of the indoor air, and provide functions for record and display of the measurement data in the real time. However, whether the long-term consistency of the performances of these product samples used in the real ambient air conditions was not evaluated in the study. In addition, the consolidated efforts from industries, academics and research institutes to disseminate the proper knowledge of carbon dioxide automatic monitoring systems are very crucial. We believe that this study can also be used as a reference for future development of the policies for indoor air quality controls at public and private premises.

Indoor air quality, automatic monitoring systems, carbon dioxide