"ABSTRACT Evaporative cooling systems have been used for millennia and represent an effective@ low energy solution for many applications in dry climates. Recently@ hybrid systems have been developed which couple the extremely high energy efficiency of indirect evaporative cooling with DX cooling. This combination enables the additional cooling and dehumidification capability of a mechanical refrigeration system while dramatically improving overall peak and annual energy use. This paper will review results of Energy Plus simulations of InDirect Evaporative-Assisted DX systems (IDEA-DX) applied in dry climates as they compare to a conventional solution. Peak power use@ annual energy consumption and indoor environmental quality differences will be compared. In addition@ field results from equipment which uses this design will be reviewed for a ""reality check"" of the simulation results."