Abstract Parametric analysis of a suspended flat plate solar air heater is presented following a transient approach. An explicit expression for air temperature has been derived as a function of time and the space coordinate. Apart from this, explicit expressions are also presented for the glass cover temperature, absorber plate temperature, useful energy and efficiency of the proposed system. The effects of several parameters, e.g. space coordinate, mass flow rate, flow velocity, air depth, absorptivity and inlet air temperature on the performance of the proposed system have also been studied. For appreciation of the analytical results, numerical calculations have been made, and the results are shown graphically.