The Cooling tower is an auditor system that is used for the heat transfer process where the heat is not useful anymore. There are several factors in the cooling tower operations that can be observed for cooling tower performance. A large number of bacteria on cooling towers become potential of scale precipitation that can decrease the cooling tower thermal effectivity because the scale will act as an inhibitor for heat transfer rate since the scale has a high value of thermal resistance. The ozone will be injected into the cooling water to reduce the scale precipitation growth rate that can decrease the cooling tower performance. This research intends to find the characteristic of the ozonation effect from cooling tower performance and water quality. The method for water quality checking is the AAS (Atomic Absorption Spectroscopy) method, Titrimetric, Gravimetric, and Spectrophotometric. The output of this research is characteristic of cooling tower performance each day and rate of water quality before and after ozonation and each day. The effectiveness value results obtained in this research was 0.12 % for the lowest value and 8.74 % for the highest value. Ozonation has been proven to improve the water quality rate of cooling towers but has not been proven to improve the performance or effectiveness of cooling towers for an ozonation period of 15 days.
Keywords: Cooling Tower Closed System, Heat Exchanger, Ozone