Indoor air exposures in damp homes are associated with adverse health effects. These associations might be explained, in part, by indoor surface chemistry. In this study, a parallel plate laminar flow reactor was designed to understand the hygroscopicity of indoor surfaces and indoor gas reactive uptake. We introduced three parallel plate flow reactor scenarios: continuously mixed flow reactor (CMFR), plug flow reactor, and laminar flow reactor to evaluate the performance and limitations of this design. With the plug flow design, we expect to be able to measure uptake coefficients (๐พ) from 10^-5 to 10^-6 for gases with a transport-limited deposition velocities (vt) in the range 0.02 ~ 0.2 cm/s. Furthermore, because we can measure vt for ozone, we can predict vt for other small polar organic compounds under similar gas concentrations and flow conditions. With this information, uptake coefficients for small polar organic compounds can then be calculated.