An Experimental Study of Thermo-Syphon Solar Water Heater in Thailand

The most widespread application of solar thermal energy is the thermo-syphon solar water heater (TSSWH). This paper presents the mathematical models and the experimental study for prediction of the temperature of hot water produced from TSSWH. Results are presented of storage temperatures, collector temperature and thermal efficiency of the TSSWH. From the experimental study during 7 days, the average thermal efficiency was found about 56.43%. The average temperature of hot water in the storage tank is 55.92°C, the average temperature of outlet during the experiment time is 68.62°C and average collector temperature is 59.08°C. Finally, the results of TSSWH economic analysis revealed that TSSWH is competitive to the conventional electric heaters, especially when utilization factor is high and electricity price is high. This study confirms the cost effectiveness of TSSWH under weather conditions in Thailand.