The geometry of the 20-L small test chamber with a rectangular
shape for measuring the performance of adsorption material is
shown in Fig. 5. The test chamber had a volume of 0.25 m
(x) 0.25 m (y) 0.32 m (z). The geometry was determined based
on an actual chamber designed for investigating the concentration
reduction performance of contaminant by a building material
coated with a photocatalyst. Two test specimens were placed in the