8.94. Spray cooling is a technique for cooling and either humidifying or dehumidifying air by contacting it with a spray of liquid water. Outlet air T (C) hai (kg W/kg dry air) Inlet air To (C) Inlet water Two (C) Inlet water Two (C) Outlet air T (C) ha2 (kg W/kg dry air) COOLER Inlet air To (C) hao (kg W/kg dry air) Makeup water HUMIDIFICATION Water removed DEHUMIDIFICATION hao (kg W/kg dry air) Problems 487 The liquid water leaving the tower is recirculated and, in the case of dehumidification, cooled before reentering the tower. Two possible paths on the psychrometric chart corresponding to two different entering liquid temperatures are shown below. On the chart, To and Tap are the dry-bulb temperature and dew point, respectively, of the entering air.