06-07: Evaporative Pre-coolers for Air Cooled Heat ExchangersEvaporative pre cooling of air cooled heat exchangers provides the thermodynamic advantages of water cooling towers with the reduced maintenance requirements of air cooled heat exchangers. In areas where water conservation, cooling tower plume abatement, or water discharge permits are a problem, evaporative pre cooling of the air going to the heat exchanger can be the solution. This paper discusses the advantages of pre coolers and presents some basic