Thermal performance and economic study of an energy piles system under cooling dominated conditions.

The rapid modernization has been mainly based on non-renewable fossil-fuels sources with the associated uncontrolled release of greenhouse gases impacting negatively on our environment. New renewal energy technologies, like shallow geothermal systems can help to solve this problem. This method harnesses constant and moderate ground temperature that is used to assist in the air conditioning of buildings. This technology is growing rapidly because it consumes less conventional energy for operation, which in turn results in fewer CO 2 emissions. A group of energy piles was installed and instrumented as part of the foundation system of a new five-story building constructed in Texas A&M University, USA. This setup is used in this research to explore the performance of this technique to control the building temperature under cooling-dominated weather conditions. This study found that integrating energy piles in building foundations could be an economical and environmentally friendly solution also under such climate conditions, but attention should be paid to the thermodynamic efficiency of the system when unbalanced pile-ground heat-transfer cycles take place through the year. ∙ Pilot energy-piles tests in a building operated under a cooling-dominated climate. ∙ Simulation of the long-term (30 years) performance of the energy pile system. ∙ Economic study anticipates a payback period of around 13 years. ∙ Prevailing cooling demand leads to unbalanced heat transfer cycles through the year. ∙ Progressive increase of ground temperature jeopardizes long-term system efficiency. [ABSTRACT FROM AUTHOR]