PDEC applications have rarely been integrated in buildings despite the fact that some have achieved significant energy savings. However, efforts have not been appropriately made to find relevant solutions that overcome deficiencies of PDEC tower systems and to identify potential problems with PDEC towers. This study was thus designed to understand the fundamentals of the down-draft evaporative cooling process so that they will be considered as a viable solution for improving sustainability in buildings. Computational modeling using FLUENT has been performed to properly model the main physical phenomenon of simultaneous heat and mass transfer as well as turbulent flows. A computational model dealing with turbulence and wall-bounded flows has been developed and various case studies have been performed. As a result, the unique characteristics of air flows within PDEC towers were determined, and down-draft evaporative cooling processes in various situations were explained. Published by Elsevier B.V.