MEASUREMENTS OF MASS ACCOMMODATION COEFFICIENTS USING A FLAT PLATE TYPE TEST CHAMBER K Ito 1,* , D N Sørensen 2 and C J Weschler 2,3 1 Wind Engineering Research Center, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa, Japan 2 International Center for Indoor Environment and Energy, Technical University of Denmark, Building 402, DK-2800 Lyngby, Denmark 3 Environmental and Occupational Health Sciences Institute, UMDNJ/Robert Wood Johnson Medical School & Rutgers University, Piscataway, NJ, USA ABSTRACT This paper reports the development of a flat plate type test chamber (FPT chamber) that can be used to obtain the mass accommodation coefficients (γ) of ozone depositing to different surface materials. The FPT chamber has one supply inlet and one exhaust outlet, with a channel cavity of dimensions 2,000 [mm] (channel length) × 300 [mm] (width) × 10 [mm] (height). Using this FPT chamber, ozone was introduced into the supply air at a constant concentration and the reduction in the concentration of the ozone after passing over the surface of the test materials was measured at a temperature of 293 [K]. Furthermore, in order to estimate directly the γ for ozone depositing to the surface of the building materials, a theoretical analysis incorporating an ozone deposition flux model was carried out in accordance with the experimental setup, and a chart was constructed which shows the relationship between γ and the average ozone concentration after ozone has passed over the surface of a given material. KEY WORDS Ozone, Flat Plate Type Test Chamber, Mass Accommodation Coefficient, Deposition Flux INTRODUCTION Indoor ozone has received attention because of its well-documented adverse effects on health. In addition to the harmful effects of ozone in itself, ozone can also initiate a series of reactions that generate potentially irritating oxidation products, including free radicals, hydroperoxides, aldehydes, ketones, organic acids and secondary organic aerosols [Weschler, 2000; 2004]. Sørensen and Weschler (2002) have used CFD simulations to examine the distribution of a hypothetical product resulting from the reaction of ozone with limonene. However, a major drawback to using numerical simulations is the lack of sufficient data on boundary conditions. In this study, we focus on heterogeneous reactions between ozone and the surfaces of various building materials. The purpose of this study is to develop a numerical method based on Computational Fluid Dynamics (CFD) to predict the ozone distribution in a room. More specifically, this study is designed to develop a reliable method, using a flat plate type test chamber (FPT chamber), to examine ozone deposition on building materials, and to estimate the mass accommodation coefficients of ozone, which are a fundamental parameter of the surface deposition flux model for ozone. * Corresponding author email: ito@arch.t-kougei.ac.jp