A general chart for sizing the collectors of solar heating systems

A general chart is developed for calculating the collector area required to provide a prescribed value of the annual load fraction for solar heating systems. The relationship between collector area and annual load fraction can then be easily obtained for specified collector design parameters, load and location. The construction of the chart is based on correlating data generated by the f-chart method. Data of 13 locations in the U.S.A. are considered. The good agreement of the results obtained by the present simple method and the f-chart for both space and combined space/domestic water heating proves that the two methods are almost of the same accuracy. Since the present chart is not location dependent and allows direct comparison of different collectors, it is a very valuable design aid for sizing and selecting solar collectors.