There is disclosed a foundation system for providing support to a structural load thereon and geothermal heat exchange using a fluid. In an embodiment, the foundation system includes at least one vertical pile member configured to install into a ground surface. A central insulated tube extends in a longitudinal direction within the vertical pile member. The central insulated tube is configured to transmit a geothermal heat exchange fluid therein. An input pipe and an output pipe are configured to transmit the geothermal heat exchange fluid through the vertical pile member and extend through the sidewall of the vertical pile member. A closed end, provided at the end of the pile member is configured to provide densified soil to increase heat transfer capability and efficiency in combination with the heat exchange limited by the central insulated tube. Other embodiments are also disclosed.