抄録
Floor heating system is widly used in Japan. Japanese building code about indoor air quality was based on 28 degree temperature and 50% humidity in summer. Floor heating system have made of plywood, MDF and other woodbased material included folmaldehyde and when running floor heating in winter, temperature inside the floor heating system become above 28 degree. When floor heating system running in winter, it is required to measure the indoor air quality in the full size house. Hot-water system and electric heater system was constructed for interior finish of the house and indoor chemical substance concentration was measured. Folmaldehyde concentration showed below the 100ug/m^3 for running floor heating system in winter.