# Numerical Analysis on the Performance of a Radiant Cooling Panel with Serpentine-Based Design
###### Abstract  
Radiant cooling systems (RCS) are gaining acceptance as a heating, ventilation, and air conditioning (HVAC) solution for achieving adequate thermal comfort and maintaining acceptable indoor air quality inside buildings. RCS are well known for their energy-saving potential; however, serious condensation problem hinders the growth of this technology. In order to prevent the risk of condensation, the supply water temperature is kept higher than the dew point temperature of the air inside the room. The full potential of the cooling power of a radiant cooling panel is limited. Therefore, this article is on maximizing the cooling capacity of a radiant cooling panel, in terms of flow configuration. Radiant cooling panels (RCP) with different chilled water pipe configurations are designed and compared, side by side with the conventional serpentine flow configuration. The cooling performance of the radiant cooling panels is evaluated by using computational fluid dynamics (CFD) with Ansys Fluent software (Ansys 2020 R2, PA, USA). Under similar flow and operating conditions, the common serpentine flow configuration exhibits the least effective cooling performance, with the highest pressure drop across the pipe. It is concluded that the proposed designs have the potential of improving the overall efficiency of RCP in terms of temperature distribution, cooling capacity, and pressure drop. a 2021 14 4744 118 June 2021 18 June 2021 23 July 2021 4 August 2021 18 June 2021 18 June 2021 23 July 2021 4 August 2021 18 June 2021 18 June 2021 18 June 2021 18 June 20  
investigation on the effect of pipe arrangement on RCP performance. The design considerations chosen for the investigation are counterflow, serpentine, and modulated spiral. It is noticeable that the tubing's geometry influences the average temperature of the core surface where each of the pipe arrangements produces a different maximum core surface temperature. In terms of pressure losses, the modulated spiral configuration exhibits the lowest pressure losses across the pipe, with better thermal homogeneity. The energy consumption of the pump can further be reduced by reducing the inlet water velocities, but more considerations about the design and configuration should be taken into account. [PERSON] et al. [5] studied two design groups of RCP systems, these being serpentine flow configurations and canopy-to-canopy-flow configurations. The simulation carried out was intended to find the influence of the panel's aspect ratio on the surface temperature distribution of the RCP. The aspect ratio is calculated as the width over the length of the RCP. A serpentine flow configuration with a higher aspect ratio exhibits greater pressure drop, due to the increasing number of bends over the serpentine tube's total length. More pumping power is required on a serpentine tube that has higher aspect ratios. However, for the canopy-to-canopy flow configurations, the aspect ratio of the RCP does not influence the cooling performance of the RCP. [PERSON] et al. [5] claim that the compactness in the RCP flow configuration can increase the ratio of cooling capacity per pumping power. A multi-segmented mini-channel radiant ceiling cooling panel (MCRCP) is a new RCP design, as proposed by [PERSON] et al. [6]. Five simulation scenarios are conducted to analyze the relationship between the MCRCP panel area and its cooling performance. MCRCP panels with aspect ratios of 1.5, 2, 2.5, 3 and 4 are chosen for analysis. Based on the findings of [PERSON] et al. [6], the cooling capacity of the MCRCP increases when the aspect ratio of the panel increases from 1 to 3. Further increasing the aspect ratio of the panel will result in decreasing the cooling capacity; the distance between the radiant panels becomes narrower, hindering the natural convection flow of the inside air [6]. Although the research on RCP flow configurations has made some progress, studies on the dynamic changes of the RCP flow configurations on the cooling performance of the RCP are still limited.