Thermal and economic analysis of low-cost modified flat-plate solar water heater with parallel two-side serpentine flow

The present study deals with the thermal performance evaluation and economic analysis of a low-cost modified flat-plate solar water heater (SWH) with a parallel two-side serpentine flow. This is a unique inexpensive and easily fabricated SWH having better thermal efficiency than those investigated by earlier authors. The solar water heating system is having parallel two-side serpentine arrangement with 68 pieces of copper elbows inclined at an angle of 908 for the water flow inside the collector. A PV panel of the suitable wattage has been applied to supply power to the controller circuit and pump which makes this system selfsufficient. This experimental setup is developed at the roof of the building keeping the fact in the mind to be used for both residential and commercial buildings as per the needs. The peak thermal efficiency of the system is 81.26 and 80.20 % individually for the months of June and July under typical climatic condition of Malaysia, while the average thermal efficiencies for the months of June and July have been found to be 70.24 and 70.96 % relatively, which is compared with those of other eight designs presented to the study. Furthermore, a comprehensive fiscal analysis for the long run using MATLAB has been presented to the study. It is found that this solar water heater is more economical than that of an electric water heater in the long run.