To simulate the use of TSSWH, the experimental was done on the sunny day. Usually
temperatures T1 and Ta(ambient) are very close together. All temperatures were recorded every 15
minutes continuously for nine hours. The outlet water temperature (T2) increases with sunlight. The hot water in the collector causes decreasing in density of the water. Then, hot water with lower density moves to the top of the storage tank. The lower temperaturewater in the tank moves downward to the inlet pipe of the collector due to its higher density.