Modelling the Relative Humidity Inside Flat Plate Collectors

A mathematical model based on physical phenomena is introduced to model the relative humidity within flat plate collectors. Using the model, the water vapor which enters and leaves the collector as well as the water which is ad- and desorbed by the thermal insulation material during operation can be calculated. The paper describes the model and shows its application on three different collectors exposed Kochi, India. The water masses which enter and leave the collector during one month of operation as well as the water masses which are adsorbed and desorbed by the thermal insulation material for the three flat plate collectors are presented. This knowledge can be used for the design of an accelerated aging test procedure for flat plate collectors. The results are discussed and an outlook for future work is given.