The purpose of this study was to investigate the effect of electronic anti-fouling (EAF) technology on fouling mitigation outside surface of a heat exchanger. The working condition of a closed cooling tower was simulated. Two tests were conducted to investigate the principle of EAF effect on an evaporative cooler spray water system in two modes: one with EAF treatment and the other without such treatment, and the artificially hardened of water is 1000 mg/L (as CaCO3). At the end of 214 h of the tests, the fouling resistance increased by 7.51% in the case with EAF treatment and by 25.14% in the case without EAF treatment, and the crystalline particles had an average diameter of 8.83 mu m and 6.34 mu m in the case with and without EAF treatment, respectively. (C) 2015 Elsevier Ltd. All rights reserved.