An evaporative cooler is a natural, inexpensive method of cooling hot dry air. In the cooler, hot dry air is drawn by a fan over a cooling unit which contains a series of wet filter pads. As the air passes over the unit, some of the water in the filter pads evaporates into the stream of dry air and, in the process, humidifies and cools the air. Water must be added to the cooler water tank. Consider the following evaporative cooler: 100 m/min of warm air at 40 C and 30% relative humidity is drawn into the evaporative cooler to produce an outlet stream of cool, saturated air at 25C. a) draw a fully-labelled flow diagram for the cooler b) using the psychrometric chart in the Appendix, determine the: humid volume of the inlet air (m3/kg dry air) moisture context of the inlet air (kg water/kg dry air) moisture content of the exit air (kg water/ kg dry air) c) determine mass flow of inlet dry air (hint: volumetric flow / humid volume) d) determine mass flow of water in inlet air (hint: mass flow dry air * moisture content) e) determine mass flow of water in outlet air (hint: mass flow dry air * moisture content) f) determine how much water needs to be added to the cooler in kg/min