The possibility of storing thermal energy within the building structure to reduce building energy consumption has been studied. Hollow core panels used for a building structure are able to pass air through core cavities and be utilized as thermal storage. Previously, thermal storage models for ventilated slab system using the panels have been developed but it has typically focused on the system development and performance evaluation under particular conditions. As a result, it has been difficult to understand the effect of the system on whole building energy performance. This study develops a computational model for a ventilated slab system and investigates its implementation in a whole building energy simulation program, EnergyPlus. The system has two major components: an auxiliary air handling unit (AHU) and a radiant slab with hollow core panels. The auxiliary AHU includes an outside air mixer, coils, and a fan to produce either conditioned or unconditioned air depending on the user's input. The air is then controlled by a defined delivery method, after passing through the cavity of the panel. This paper illustrates the new model development for the building energy simulation program and provides some evaluation with an existing model from another study. (c) 2012 Elsevier B.V. All rights reserved.