System design in solar water heaters with natural circulation 

 -  Solar Energy, 12, p.163-163, 1968 .
<br/><br/> A computer model for predicting the thermal performance of domestic solar water heaters, employing thermosyphon circulation between the collector and the insulated storage tank. is described. Absorber plate efficiency factor as computed by the computer in terms of its geometry and material specifications along with its thermal capacity have been incorporated in the model. The solar radiation intensity on. tilted surface has also been computed in terms of the measured horizontal component. The radiation intensity and ambient air temperature have been harmonically analysed and twelve harmonics have been found adequate as input for the model, ldeal condition of no drain-off during the day is assumed. Proving sets for clear and cloudy weather, comparing the predicted results with the observed values are also shown. Results of design studies on the collectors, two circulation pipe diameters, four heights between the collector top and the tank bottom, three (length/breadth)ratios of the absorber for a fixed collector area and three ratios of tank dimensions (height/alia.)for a specified capacity are discussed.