608 EVAPORATIVE COOLER

An evaporative cooler lowers the dry bulb temperature of an entering air 
stream by adding water to it.  The wet bulb temperature stays constant in 
this process while the psychrometric state approaches the saturation curve.
The entering air state is identified as "E"; the leaving air state is 
identified as "L".  The degree to which the dry bulb temperature approaches 
the wet bulb temperature is characterized by an effectiveness, "eff".  Hence 
the leaving dry bulb temperature, "LDB", is given by
		
		LDB = EDB - eff*(EDB - EWB)                           (3.5.1)

where "EDB" and "EWB" are the entering dry and wet bulb temperatures, 
respectively (Sauer and Howell 1992).

	Type 71 inputs, parameters, and outputs include:
		xin(1)          entering dry bulb temperature [C]
		xin(2)          entering wet bulb temperature [C]
		xin(3)          dry air mass flow rate [kg/hr]
		par(1)          evaporative cooler effectiveness
		out(1)          leaving dry bulb temperature [C]
		out(2)          leaving wet bulb temperature [C]
		out(3)          dry air mass flow rate [kg/hr]

References:
	
	Cross, Kevin, An Evaluation of Ice and Chilled Water As Thermal 
Storage Media for Combustion Turbine  Inlet Air Cooling Systems, M.S. Thesis, 
p 26, University of Wisconsin, Madison, 1994.

	Sauer, Harry J. and Ronald H. Howell, Principles of Heating, 
Ventilation, and Air Conditioning, p 17.5, American Society of Heating, 
Refrigerating, and Air Conditioning Engineers, Atlanta, 1992.