Abstract: A flat plate solar air collector with baffles was studied. Several factors that have influence on the thermal performance of the solar collectors were analyzed. The paper investigated the relations between the efficiency factor, the heatremoval factor of the solar air collector and the total heat loss coefficient, baffles fin efficiency, air velocity inside the flow channel, the space between baffles, and the height of baffles. Also, the time constant of the collectors was studied. The theoretical formula of the collector’s thermal efficiency was obtained, which can be used for design and application of such kind of collectors.

Key words: solar air collector, efficiency factor, heatremoval factor, baffles