Cooling towers and air washers are members of the heat exchanger family. The function of both systems is to bring the air and water into direct contact. Heat is rejected by evaporation from a drained water film into air flowing through a cooling tower and the heat is transferred from the air into flowing through the air washer. The air washer could be integrated into a thermally powered summer air-conditioning system (cooling system). In this paper, a mathematical model for an air washer is developed and used as the basis for a comparison of seven proposed air-conditioning systems. Each of these systems consists of an air washer and either a chemical dehumidifier or a water chiller. Commercial units are chosen and their technical data are used in the system performance evaluations. The performance of each system is studied and the system outlet air temperature is determined for a specified value of outlet air humidity ratio and variable ambient air humidity ratio. For the purposes of comparison, the power consumption per unit air temperature drop is determined and compared for all the systems.