In this study, the performance of a novel integrated system of indirect evaporative cooler with internal baffles as air pre-cooling unit and evaporative condenser has been experimentally investigated. For this purpose, the experimental setup consisting of an indirect evaporative cooler with internal baffles followed by an evaporative condenser contains the hot water serpentine tubes with external thin film cotton layer was designed, constructed and tested. The influences of pre-cooling unit and the external thin film cotton layer on the performance of the evaporative condenser are investigated. The experimental results show that, for increasing the air flow rate from 250 to 1450 m(3)/h, the temperature difference of hot water through the evaporative condenser change in the ranges between 13 and 24.9 degrees C for the case without pre-cooling unit, 17.6-38.4 degrees C for using the pre-cooling unit with internal baffles and with use the thin film cotton layer. Also, the rate of change of the cooling load is in the ranges between 166 and 318 kW for case without pre-cooling unit, but for using the pre-cooling unit with internal baffles and with use the thin film cotton layer the cooling load change between 224.7 and 4903 kW. For using the external thin film cotton layer on the tubes of cross flow heat exchanger and with use the pre-cooling unit with internal baffles before the evaporative condenser the percentage increases in the cooling load change between 35.4 and 54.2% compared to the evaporative condenser without pre-cooling unit. (C) 2017 Elsevier Ltd. All rights reserved.