Experimental investigation of a novel PCM-enhanced underfloor heating system for energy-efficient sustainable buildings

Building energy efficiency can be enhanced by reducing heating and cooling demands, a crucial factor for sustainable development. This study experimentally investigates a novel underfloor heating system enhanced with thermal energy storage using an organic phase change material (PCM) encapsulated in paraffin wax. The PCM was positioned between heating pipes, and experiments were conducted in a temperature-controlled room. The thermal performance of the PCM-integrated system was compared to that of a conventional system without PCM. Results show that the PCM-integrated system increased room heating durations by 27-33 % and cooling durations by 35-43 %. During the 7-h experimental period, the conventional system consumed thermal energy at a rate of 114.88 kW, whereas the PCM-integrated system consumed only 111.01 kW, corresponding to a 3.4 % reduction. Additionally, surface temperature fluctuations were reduced by 52.6 %, improving thermal comfort. These results demonstrate that the inclusion of PCM significantly extends heating and cooling cycles, enhances thermal comfort by minimizing temperature fluctuations, and improves overall energy efficiency by reducing heat transfer to the floor mortar. This innovative approach not only advances energy-efficient heating technologies but also contributes to reducing environmental impacts.