ABSTRACT: A three dimensional numerical model of a PVC water pipe embedded inside an insulated concrete form wall was numerically developed. Different wall thickness sizes and optimal distance between pipes were analyzed. Three inlet temperature and four inlet velocity for each set have been studied. Thermal behavior of the concrete was investigated in a transient mode. This study focused on storing thermal energy inside the wall and using it when there is a demand rather than transferring heat for space conditioning. Predicted heat transfer rate and potential thermal energy storage were tabulated. In general, this study helps designers to gain detail understanding of heat transmission between water pipe and concrete.