Owing to the lack of synchronization between the solar energy availability and the heat demands in a specific application, the energy storing sub-system is necessary to maintain the continuity of thermal process. The present work is dealing with an active solar heating storing system in which an air solar collector is connected to storing unit where this energy is distributed and provided to the heated space in a controlled manner. The solar collector is a box type absorber where the air flows between a number of vanes attached between the collector absorber and the bottom plate. This design can improve the efficiency due to increasing the heat transfer area exposed to the flowing air, as well as the heat conduction through the metal vanes from the top absorbing surface. The storing unit is a packed bed type where the air is coming from the air collector and circulated through the bed in order to add/remove the energy through the charging / discharging processes, respectively. The major advantage of the packed bed storage is its high degree of thermal stratification. Numerical solution of the packed bed energy storage is considered through dividing the bed into a number of equal segments for the bed particles and solved the energy equation for each segment depending on the neighbor ones. The studied design and performance parameters in the developed simulation model including, particle size, void fraction, etc. The final results showed that the collector efficiency was fluctuated between 55%-61% in winter season (January) under the climatic conditions of Misurata in Libya. Maximum temperature of 52ºC is attained at the top of the bed while the lower one is 25ºC at the end of the charging process of hot air into the bed. This distribution can satisfy the required load for the most house heating in Libya.
 Trombe F., J. F. Robert, M. Cabanot, and B. Sesolis: Concrete walls to collect and hold heat. J. Solar Energy 2, 13, 1977.
 Duffin R.J. and G. Knowles: Simple design method for the Trombe wall, J. Solar Energy 34, 69, 1985
 Neal W. E. J., D. L. Lovedy, and M. Pabon-Diaz: A solar –assisted heat pump and storage system for domestic space and water heating using a conventional roof as a radiation absorber, Proc. I.S.E.S, Silver Jubilee Congress, Atlanta, GA, U.S.A., Sun II 1, 822, 1979.
 Matrawy K. K.: Theoretical analysis for an air box heater with a box type absorber, J. Solar Energy, 63, 3, 1998.
 Chiou J. P., M.M. El-Wakil. and J. A. Duffie: A slit and expanded aluminum foil matrix solar collector, J. Solar Energy, 9, 73, 1965.
 Hamid Y. H. and W. A. Beckman: Performance of air-cooled, radiatively heated screen matrices, Transactions of ASME, J. of Engineering for Power 93, 221, 1971.
 Neeper D. A: Analysis of matrix air heaters, Proc. I.S.E.S Congress, Atlanta, V.1. Pergamon Press, Elmsford, NY, 1979.
 Choudhury C., S. L. Andersen and J. Rekstad: A solar air heater for low temperature application. J. Solar Energy 40, 335-343, 1988.
 Han J. C.: Heat transfer and friction in channels with two opposite rib-roughened walls, Transactions of ASME, J. Heat Transfer 106, 774-781, 1984.
 Ligrani P. M. and R. J. Moffat.: Structure of transitionally rough and fully rough turbulent boundary layers. J. Fluid Mechanics 162, 69-98, 1986.
 Schumann T. E. W. and J. Franklin Inst.: Heat Transfer, A liquid flowing through a porous prism, 208, 405, 1929.
 Kuhn J.K., G.F. Von Fuchs, A. W. Warren, and A. P. Zob: Developing and upgrading of solar system thermal energy storage simulation models, Report of Boeing Computer Services Company to the U. S., Dept. of Energy,1980.
 Hughes P. J.: The design and predicted performance of arlington house, M.S. Thesis in Mechanical Engineering, University of Wisconsin – Madison, 1975.
 Duffie J. A. and W. A. Beckman: Solar Engineering of Thermal Processes, 2nd ed.. Wiley Interscience, New York, 1991.
 Moustafa M. Elsayed, I. S. Taha, and J. A. Sabbagh: Design of Solar Thermal Systems, Scientific publishing center, King Abdalaziz Unversity, Jeddah, 1994.