新築臭の原因と模型実験の妥当性の確認

Abstract

The purpose of this study is to establish the evaluation and measurement methods of the odor of new constructed houses based on the electronic nose analysis. In recent years, the number of complaints against the nasty smell in new constructed houses has been increased. But the evaluation and measurement methods for the perceived air quality in the new constructed houses have not been established. The previous studies concerned with the perceived air quality in the new constructed houses are intended to identify the appropriate finishing materials that may not emit a powerful smell. The measurement and evaluation methods for the odors emitted from finishing materials in the previous studies are mostly based on the sniffing tests by the subject. While the measurement of the odor intensity based on the triangular odor bag method is relatively simple, the specification of odor characters needs the complicated process. For example, ISO have many standards of ISO 5496” Initiation and training of assessors in the detection and recognition of odours”, ISO 8586” General guidelines for the selection, training and monitoring of selected assessors and expert sensory assessors” and ISO 11035” Identification and selection of descriptors for establishing a sensory profile by a multidimensional approach” and et.al. for the sensory analysis to specify the odor characters. In this paper, the electronic nose is adopted to measure the odors emitted from finishing materials. This analyzer has the technique of odor similarity mapping represented in the radar chart in order to make clear the odor characters. The specification of odor characters obtained by the electronic nose is comparatively easy as compared to the sensory analysis. In the first stage of this study, a field research for the perceived air quality in the new constructed houses was carried out. The nasty smell in the new constructed 12 dwellings of 8 detached houses, 4 units of the newly-built two apartments were analyzed by the electronic nose. The odors diffused from the floor components, the wall components and the ceiling components comprised with multiple finishing materials such as a structural plywood, an adhesive, a composite flooring, a gypsum plaster board and a vinyl wall paper are focused. The following results were obtained. (1)The perceived air quality among the new constructed houses with the same material and the components specifications for interior finishes is similar. (2) The main source of the nasty smell in new constructed houses is suggested to be the odors dissipated from interior finishing materials. The small chamber tests for the similarity level among the odors emitted from the floor components, the wall components, the ceiling components and the nasty smell in new constructed houses of the field survey were conducted. The similarity between the actual odors in the new constructed houses and the odors emitted from the floor components is high, but the other odors dissipated from the wall components, the ceiling components, the adhesive, the composite flooring and the gypsum plaster board have low similarity to the actual odors. Model experiments may be necessary to elucidate the odor pollution mechanism. As the first step, the odor in a test chamber set in the same floor component, wall component and ceiling component as actual one was confirmed the reproducibility of the perceived air quality in the new constructed houses.