Investigation of an inexpensive solar collector storage system

An integrated rock bed and solar collector system was investigated both experimentally and theoretically. The system consists of an insulated galvanized iron box containing rocks. It may act as both a solar collector and as a storage system. The measured parameters were the inlet and outlet air temperatures, the bed temperature, the ambient temperature and the solar insolation. Further, the measurements were performed at different values of tilt angle and mass flow rate of air. It was found that the bed had a maximum storage efficiency of 46% when it was tilted at an angle of 47 degrees. Finally, the agreement between the experimental results and theoretical predictions was rather a good one. (C) 1997 Elsevier Science Ltd.