A study of air, water and VOC transport through building materials with the deal chamber system

Advanced simulation models for building envelope and IAQ analyses need detailed material properties. The properties that are needed include the characteristics of heat, air, moisture and VOC transport and storage. A test method to measure diffusion and sorption properties of building materials is introduced. The system consists of two individually controllable (airflow, humidity, VOC) small chambers - one on each side of the material layer to be investigated. The method was applied to measure the transport of some volatile organic compounds (VOCs) through typical building materials. The method is also used for water vapor transport measurements and results were compared against those using traditional cup methods. Similarities between VOC diffusion and water vapor diffusion were investigated. This paper presents the test method and results for air and VOC transport through gypsum board and OSB (oriented strand board). The small environmental dual chamber test facility used in this study consists of a clean air supply system, chamber assemblies, flow control system, air humidity, temperature and pollutant monitoring system and a data acquisition system. The two chambers A and B, with dimensions of 14in × 14in × 6in (0.35m × 0.35m × 0.15 m), were made of electro-polished 316 stainless steel. Toluene and Decane were injected respectively as a pollutant source in each test. Air, water vapor and VOC concentrations were measured in the two chambers and both transient and steady state data were recorded. Effective diffusion coefficient of each pollutant for Gypsum and OSB were obtained in steady state condition. Results were compared to the previous literature and water vapor transport results. The possibilities of minimizing the effort to measure material properties for various materials and compounds are discussed.