GARD developed and integrated modules into the source code for EnergyPlus to simulate active desiccant dehumidifiers. The desiccant module includes heat regenerated desiccant wheels, heat exchangers, evaporative coolers, and associated controls. This module determines the process air outlet conditions, the load on the regeneration heating coil, the electric power consumption for the wheel rotor motor, and the regeneration air fan mass flow rate. All other heat exchangers are modeled as separate objects connected to the inlet and outlet nodes of the dehumidifier. GARD has worked extensively with modeling desiccant dehumidifiers on other projects and has developed both built-in subroutines and a custom function for DOE-2 to model various types and configurations of desiccant dehumidifiers. These prior models were used as the algorithmic basis for the EnergyPlus modules.