The energy savings potential and indoor comfort implications of economizer controls for packaged rooftop HVAC equipment is investigated. Past discussion has centered on comparing the energy savings of temperature- and enthalpy-based economizer controls. The model used in this simulation goes into significant detail to model the physical properties of the building, equipment, and controls. The simulation is dynamic, tracking the minute-by-minute building parameters of temperature and moisture. This detail is not essential for gross energy savings estimates, but it is necessary to examine indoor comfort (temperature/humidity) conditions resulting from different economizer control strategie& The results show that differential enthalpy economizer control provided the most energy savings while still maintaining comfort in the building modeled.