Packed bed is generally recommended for attaching with solar air heater in order to store thermal energy of hot
air. For designing such a system under the given system and operating parameters, it is required to predict performance of
the system by using mathematical models. In the present paper an attempt has been made to discuss mathematical models
reported in the literature for predicting thermal performance of packed bed energy storage system for solar air heaters. The
designer may be benefited from the consolidated information reported in the present paper.