SURVEY ON INDOOR AIR QUALITY IN CONTEMPORARY RESIDENTIAL BUILDINGS IN JAPAN

In order to facilitate rational development on the efficient new ventilation system with new detectors against the health problems caused by VOC in residential buildings, authors studied to clarify the actual IAQ conditions around occupied area. To grasp the contemporary circumstances and transfer-mechanisms of VOC in houses, the actual data regarding the pollutants and its movement were collected in 9 detached houses in Tochigi prefecture. In this paper, investigated results for indoor thermal environment, ventilation and indoor chemical pollutants are described. In this study, an interesting decreased trend of average concentration of formaldehyde was found. Steady appearance of alternative chemicals such as various carbonyls, and frequent observation of unexpected TVOC value over 400µg/m3 are discussed. A composition ratio of VOCs and its characteristic were analyzed. The results of this research were compared with that of the past nationwide research in Japan. As a result, comparing two constructions between Japanese conventional method and 2×4 method, each characteristic of indoor air pollutions was identified. The characteristic of indoor chemical pollutions in 9 houses in Tochigi prefecture was similar with that of the past nationwide research in Japan