Thermal comfort: CFD insights into radiant cooling panel systems

This paper investigates thermal comfort levels in a three-room apartment using computational fluid dynamics (CFD), with a focus on the integration of a novel solar PV power cooling system. In hot and humid climates, there is a growing need to explore advanced technologies not only to improve the energy efficiency of systems but also to enhance indoor comfort levels. Simultaneously, the abundant availability of solar energy in many regions suggests the use of photovoltaic panels to sustainably power these systems. For this purpose, the proposed system combines a radiant cooling ceiling with a PV-driven vapor-compression system and utilizes phase change material (PCM) stored in a water tank as thermal storage. The storage tank is needed to accomplish the thermal request when no solar energy is available. The analysis evaluates the optimal placement of the radiant panel in an apartment, considering both ceiling and lateral wall configurations. Results indicate a significant enhancement in the Predicted Mean Vote (PMV) index when adopting ceiling panels. In addition, PMV values found in the zones exposed to the envelope components subjected to solar radiation are lowered transitioning from an average value of 0.7 to 0.2, nearing a neutral sensation. In fact, ceiling panels induce convective airflow, while lateral panels lead to air stratification. Moreover, the study highlights improvements in radiant asymmetry and vertical air temperature gradients when adopting ceiling panels supporting the upgrade in comfort levels reachable with ceiling panels. Given its potential benefits, this innovative system is studied virtually in the context of Malaysia's hot and humid climate. These findings provide valuable insights for optimizing thermal comfort in apartments located in such climates, where radiant panels may be employed.