This book covers different cooling techniques used for compressor intake air in Gas turbine power plants. It emphasizes on the performance analysis of three main cooling methods- evaporative cooling, vapor compression and absorption chiller system. Evaporative cooling is the simplest one and results in air temperature reduction of 13.6, 15.0 and 2.7°C in moderate, hot and dry, and cold and humid ambient air conditions respectively. Vapor compression system is highly efficient but uses high quality energy as the system input, thus, is less economic. Absorption chiller system is most useful system as this system utilizes the waste heat of the power plant.