# Numerical Analysis on the Performance of a Radiant Cooling Panel with Serpentine-Based Design
## 4 Conclusions  
The aim of this research is to develop CFD numerical simulations in order to test and simulate some basic design aspects of the RCP system. A three-dimensional model of the RCP is used to study the performance of the RCP, in terms of temperature distribution, cooling capacity, and pressure drop across the pipe. The study is conducted on three different pipe configurations, which are one-inlet-one-outlet serpentine, two-inlet-two-outlet counterflow serpentine, and three-inlet-three-outlets serpentine flow configurations. Under the assumed operating conditions, the main findings of this research are as follows:  
1. The two-inlet-two-outlet counterflow serpentine flow configuration leads to better temperature uniformity. The best result in terms of low and uniform temperature distribution can be obtained with the counterflow design because it produces the lowest temperature difference of the panel's surface temperature, with a 4.505 \({}^{\circ}\)C temperature difference. 2. The common serpentine flow configuration exhibits the lowest cooling performance, with the highest pressure drop across the pipe. The single pipe of the common serpentine flow configuration has a pressure drop of as much as 129.4225 Pa, which greatly influences the energy efficiency of the pump. 3. Pressure drops can be reduced by reducing the number of bends of the pipe, as the loss coefficient factor increases with every bend. Design 1 has six bends in a single long pipe, resulting in the highest total loss coefficient value, while Design 2 and Design 3 have fewer bends for each pipe. The pressure drop obtained is higher in a pipe that has a higher number of bends. 4. Increasing the number of inlets and outlets of the serpentine flow configuration may not make a significant impact on the cooling performance. However, the arrangement of the pipe configuration, such as the location of the inlets and outlets of the pipe and also the compactness of the pipe arrangement, may influence the cooling performance of the RCP. It can be concluded that the common serpentine flow configuration does not give the best performance for the RCP. The common serpentine flow configuration exhibits the lowest cooling capacity, with 11.446 W/m\({}^{2}\). The highest cooling capacity of 31.198 W/m\({}^{2}\) is obtained from the two-inlet-two-outlet counterflow serpentine flow configuration. Both of the proposed flow configurations outperform the common serpentine flow configuration in terms of cooling capacity, temperature distribution, and pressure drop. Therefore, the cooling performance of RCP can be improved by implementing different flow configurations for the RCP. Moreover, flow uniformity is a significant factor influencing the efficiency of any thermal system, including an RCP. Applying a different pipe configuration to the RCP will affect the flow uniformity and the temperature distribution uniformity. Therefore, an RCP should be designed with care to provide sufficient indoor cooling with maximum thermal comfort. In order to achieve this, it is recommended that more research be conducted on the design of RCP; there are many other innovative flow configurations that can be implemented in the RCP. The search for the best design of RCP is a never-ending journey as there is no limit to ideas. In the quest for an improved panel architecture, it is important for us to report and document the current results, as they can serve as guidance for future research. Conducting the numerical simulation by using a full version of Ansys Fluentis suggested, to eliminate any uncertainties from the meshing, so that grid-independent tests can be conducted with a larger number of elements. To further validate the energy efficiency of these three designs, future research plans will include experimental and simulation studies on energy consumption for the pumping power of the three designs. Conceptualization, C.W.L. and S.P.K. ; methodology, M.H.M.R., C.W.L. and N.A.A. ; software, M.H.M.R. ; validation, M.H.M.R. and C.W.L. ; formal analysis, M.H.M.R. and C.W.L.