Thermal comfort and energy performance analysis of a wall radiant cooling panel coupled with impinging jet ventilation

Rising cooling demand and increasing concerns over indoor air quality have highlighted the limitations of conventional heating, ventilation, and air conditioning (HVAC) systems. Hybrid cooling strategies that combine ventilation and radiant cooling have emerged as promising solutions for improving thermal performance and energy utilization. This study experimentally and numerically investigates the performance of a hybrid cooling system integrating a wall-mounted radiant cooling panel with an impinging jet ventilation (IJV) system. The system combines sensible cooling from a cooled wall surface with a pre-cooled impinging jet delivered through a wall-integrated plenum to enhance thermal comfort with low energy use. Steady-state experiments were conducted in a full-scale chamber (3 m × 3 m × 2.9 m) to validate a three-dimensional computational fluid dynamics (CFD) model, which showed good agreement with measured air velocity and temperature fields. The validated model was used to assess system performance under varying inlet air temperatures, chilled-water temperatures, and a constant airflow rate of 0.039 m³/s. Results show low vertical temperature differences within the occupied zone and improved energy performance. An optimal condition was identified at 24 °C inlet air and 16 °C inlet water temperatures, yielding a maximum energy utilization coefficient (Et) of 1.37.