Solar clean energy can be harnessed by several methods using technologies like solar heating, photovoltaic cell, solar architecture, photosynthesis. Solar energy is converted either by active technologies or by passive technologies by the method they capture and distribute solar energy. In view of this, the paper represents the optimization result on Nusselt number and thermal efficiency for 3 sides roughened solar air heater using the hybrid approach of response surface method (RSM) and multi objective particle swarm optimization (MOPSO) algorithm. The values of input parameters are taken according to the experimental values. The value of the output parameters, Nusselt Number and thermal efficiency are found to be in the range of 65–80 and 63–75%, respectively, for the optimum value of the input parameters are Reynolds number, 12000–13000, the relative roughness pitch, 10, the relative roughness height 0.03–0.04 and the rate of mass flow is 0.04 kg/s using MOPSO approach, and the optimum solution is identified by application of maximum deviation theory (MDT) approach. A confirmative test has been conducted to validate the optimum results obtained with an error of 3.39 percentages. © 2020, © 2020 Taylor & Francis Group, LLC.