In the present communication, a generalized procedure has been described for the performance evaluation of a solar air heater with N-subcollectors with identical collector aspect ratio connected in various combinations such as in series, parallel and series-parallel. It has been found that the performance of a solar air heating system can be improved by operating several subcollectors in series in place of a single large collector with the same total area. Results have been presented to show the effect of various design parameters, viz. collector aspect ratio, mass flow rate, etc. on the performance of solar air heater with N-subcollectors in series, parallel and series-parallel combinations.