This paper describesthe results of accelerated particulate fouling tests performed on two enhanced tubes used in waterchiller condensers. Thefouling tests were performed using ferric oxide powder as.the foulant material with foulant concentrations between 1000 and 2000 ppm. Data are also presented for on-line brush cleaning and high-velocity flush cleaning. The water used in these tests is much dirtier than would be expected in an actual operating system. The key purpose of the tests was to determine the fouling rate of the enhanced tubes compared to that of a plain tube.