DESCRIPTION :- Air Washer Test Rig unit is required to conduct experiments and demonstrate the basic principal of psychometric properties of air. The test rig is designed for study of humidification of air. The unit is provided with all instruments and facilities to measure the temperature wherever required. The setup also provides the facility to conduct the experiment of heating and cooling of air and humidification. EXPERIMENTATION :- To study the operation cooling & humidification, hot air humidification, heating humidification of air. To calculate the change in specific humidity of air. To calculate the change in temperature of air.