Formation of Quality Indoor Air in Wooden Buildings with Domestic Wood

The change over time of the indoor air quality of a special elderly nursing home made of wood was investigated. The direct measurement of indoor air revealed that the main component was terpenes, a known source of woody aromas. The contribution of each part of the woody interior to the quality of the indoor air was investigated using an emission test cell method. The results showed that α -Pinene, the main component of the detected terpenes, was emitted from Hinoki timber used for the post and brace, and that sesquiterpenes （ α -Muurolene, Calamenene, δ-Cadinene, etc.）, which counted for 10-40% of the detected aroma, were emitted from the sugi lumber used for flooring and roof sheathing. A year after construction, the concentrations of some sesquiterpenes, including Calamenene, which is a source of woody aromas, had increased although the total amount of terpenes had decreased. Consequently, it was found that of the indoor air components the woody aroma mainly derives from terpenes.