Construction, Evaluation, and Performance of a Water Condensation Test Unit

The study of water condensation phenomena is important in order to evaluate the performance of materials and coatings employed in the fabrication of waste heat recovery units including heat exchangers, heat pipes, condensing economizers and related functional surfaces. Fast evaluation of lab-scale samples is important during research and development of coatings for wetting phenomena under controlled, reproducible, and stable humidity and temperature conditions of both sample and environment. To study these effects, we report on the construction of a lab-scale condensation chamber, along with its evaluation and benchmarking with superhydrophobic coatings on stainless steel using perfluorooctyl silane (PFOTS). A working unit has been successfully fabricated and applied in a highly responsive device capable of recording the condensation performance of flat specimens under controlled conditions. Sample temperature was maintained with 0.10 °C deviation. The humidity response time of the chamber is 17.2 s per degree of RH% while the maximum relative humidity variation is +/- 3.2%RH. The unit successfully delivered valuable data over hydrophillic, hydrophobic and superhydrophobic surfaces. Data useful for studying open research issues such the relationship of contact angle and condensation phenomena.