Solar air heaters; Flow channel; Thermal efficiency
The optimum flow channel depth and mass flow rate in 10 different designs of solar air heaters have been obtained. The design variations considered are flat absorber type with and without cover glazings; single, double and triple pass etc. It is found that there exists an optimum mass flow rate corresponding to an optimum flow channel depth, for each design considered. The thermal efficiency of each design is then obtained under the optimum conditions. It is found that a single glazing solar air heater operating under double flow configuration gives the best performance.