Investigation on Indoor Air Quality in University Libraries in Xi'an

This paper studied seven libraries in the University of Xi'an (Northwestern China) to determine the presence of polluting agents such as particle matter less than 10μm (PM₁₀), formaldehyde and total volatile organic compounds (TVOC). Data were collected on the main structural characteristics of the buildings; indoor microclimate parameters, such as temperature and relative humidity were also monitored. The study showed that high concentration of PM₁₀ was found in the seven libraries, and the value of five libraries exceeded the National Standard. The highest value of PM₁₀ concentration was 0.645mg/m³ which was 4.3 times of the National Standard value. Only one library was found that the concentration of TVOC exceeded the National Standard, and no exceeding value of formaldehyde was found. Future more, the relationship between indoor and outdoor levels of PM₁₀ and that of library service time and concentration of TVOC were defined. Thermal comfort in the monitored libraries was mostly acceptable but the relative humidity tended to be much lower.