Investigation of Thermal Comfort and Optimum Supply Water Temperature in the Double Layered Thermally Activated Building System

The adoption of low-temperature heating systems in buildings has become increasingly popular to reduce energy consumption and enhance energy efficiency. In our previous study, a novel hydronic radiant heating system integrating both Underfloor Heating and Thermally Activated Building Systems (TABS) on the same floor was developed. The optimization process was based on thermal comfort criteria defined in ASHRAE 55 and ISO 7730, using floor surface temperatures obtained via FLUENT/ANSYS simulations. The Generalized Reduced Gradient (GRG) algorithm was employed, with Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfaction (PPD) indicators to assess thermal comfort. Present study aims to optimize the supply water temperature for the "Double Layered Thermally Activated Building System" (DLTS), ensuring thermal comfort and energy efficiency. Results indicated that for thermal neutrality, the optimum supply water temperature was 26.66°C, and the optimum surface temperature was 23.60°C. The DLTS system met the comfort criteria with PPD values below 12.14 for class C, demonstrating high user satisfaction. This research highlights the potential of DLTS to improve both energy efficiency and thermal comfort in buildings, offering valuable insights for future building system designs.