Effect of plates coating on performance of an indirect evaporative cooling system

In this paper an experimental analysis of two different indirect evaporative cooling (IEC) systems is carried out: in the first one plates heat exchanger are finished with a standard epoxy coating (STD) while in the second one a novel hydrophilic lacquer is adopted (HPHI). Firstly, static contact angles, water retention and transient drop-surface interaction of both materials are evaluated. Secondly, IEC systems performance is measured in different operating conditions and, in particular, varying the water flowrate and nozzle position (top and side). Results highlight that contact angles of HPHI coating are always lower than the ones of STD treatment: according to these findings, in case of water distribution from the top of the IEC system, wet bulb effectiveness of HPHI device is higher than that of STD unit (up to 10%). Instead, in case of water flow supplied from the side of the system, no significant differences have been observed. (C) 2019 Elsevier Ltd and IIR. All rights reserved.