INTRODUCTION Finned-tube heat exchangers are widely applied as evaporators of air conditioners. The aluminum fins are usually coated with hydrophilic materials in order to promote the hydrophilicity of fins and the air-side performance of the finned-tube evaporators under dehumidifying conditions (Hong 1996; Wang and Chang 1997; Ma et al. 2009). The employment of hydrophilic coating can effectively reduce the contact angle of the condensate water and improve the condensate drainage so that the higher heat transfer coefficients and the lower pressure drops can be achieved. However@ the hydrophilic coating on fins may be destroyed by salt spray corrosion (SSC) (Yang 2003; Hao et al. 2007; Bao et al. 2008)@ resulting in the change of the heat transfer and pressure drop performance. Salt spray corrosion is a corrosion caused by the deposition of a certain amount of Cl?C on fin surfaces (Ahn and Lee 2005)@ and it often happens in high salt concentration districts@ e.g.@ coastal areas. Therefore@ it is necessary to pay attention to the effects of SSC on the air-side performance of finned-tube heat exchangers with hydrophilic coating@ including the effects on hydrophilicity@ air-side heat transfer@ and pressure drop performance. A lot of hydrophilicity-related research focuses on the long-term hydrophilicity of hydrophilic- coated fins (Shin and Ha 2002; Min et al. 2000; Min and Webb 2002; Kim et al. 2002). It is found that the hydrophilicity of hydrophilic-coated fins generally changes with service time. Both the advancing and the receding dynamic contact angles obviously increase with the increase of wet/dry cycles@ indicating that the hydrophilicity of fins is degraded with the increase of wet/dry cycles (Min et al. 2000; Min and Webb 2002). The reason for the degradation of the hydrophilicity may be that the hydrophilic coating is partially dissolved by the condensate water. However@ the hydrophilicity of plasma-hydrophilic-coated fins does not change with service time@ obviously. Kim et al. (2002) did experiments on the long-term hydrophilicity for the finned-tube heat exchangers with plasma-hydrophilic coating@ and the experimental results showed that the air-side pressure drops did not change with the increase of wet/dry cycles. The impact of hydrophilic coating on the air-side heat transfer of finned-tube heat exchangers has been researched@ and it is found that the impact at dry conditions is different from that at wet conditions (Wang et al. 2002; Hong and Webb 1999@ 2000). In dry conditions@ only sensible heat transfer occurs and the sensible heat transfer coefficient is hardly affected by hydrophilic coating@ so the effect of hydrophilic coating on heat transfer is negligible (Wang et al. 2002). In wet conditions@ latent heat transfer and sensible heat transfer occurs simultaneously. The latent heat transfer coefficient could be obviously enhanced under wet conditions by hydrophilic coating (Wang et al. 2002; Hong and Webb 1999; Hong and Webb 2000)@ while existing research on the effect of the hydrophilic coating on the sensible heat transfer coefficients under wet conditions could not reach a consistent conclusion. Wang et al. (2002) found that the sensible heat transfer coefficients degrade as the effect of hydrophilic coating@ and the degradation of the sensible heat transfer coefficients may be up to 20%. However@ the experiments conducted by Hong and Webb (1999@ 2000) indicated that the hydrophilic coating has no influence on the sensible heat transfer coefficients. The impact of hydrophilic coating on the air-side pressure drop of finned-tube heat exchangers has been researched@ and it is found that the impact is related to the working conditions (Wang et al. 2002; Hong and Webb 1999@ 2000). In dry conditions@ the effect of hydrophilic coating on the air-side pressure drop can be negligible (Wang et al. 2002). In wet conditions@ the effect is obvious and related to the inlet air humidity. The larger the inlet humidity@ the greater the impact on the pressure drop. Compared with the finned-tube heat exchanger without hydrophilic coating@ the air-side pressure drop of those with hydrophilic coating degrades by 15%?C40% under wet conditions (Wang et al. 2002; Ma et al. 2007). About the effects of SSC on the air-side performance of heat exchangers@ the existing research mainly focuses on the anticorrosion of aluminum alloy fins (Birol et al. 2002)@ the anticorrosion of the anti-corrosive layer of aluminum fins (Lifka and Vandenburgh 1995)@ and the evaluation method of corrosion degree of vacuum brazed aluminum heat exchangers (Scott et al. 1991). However@ there is no publication about the effect of SSC on the hydrophilicity@ the air-side heat transfer@ and pressure drop performance of finned-tube heat exchangers with hydrophilic coating. The purpose of this study is to investigate the effect of SSC on the hydrophilicity@ the air-side heat transfer@ and pressure drop performance of finned-tube heat exchangers with hydrophilic coating. For this purpose@ experiments are done on heat exchangers with different corrosion degrees as well as on those without corrosion@ and the results are compared.