The ever increasing demand of useful energy and depletion of conventional energy resources give rise to highly energy efficient and compact thermal systems. Solar energy is the foremost source of unconventional energy which has adequate potential to fulfill all energy needs of the modern world.decades, more attention is being focused towards performance up gradation of energy exchange devices utilized in solar energy collection and storage systems. Flat plate solar collector is undeniably one of the simplest and inexpensive types of heat exchanger widely used for air heating applications. Solar air heater utilizes solar insolation to heat up the absorber plate which transfers heat to the air flowing through the system mainly by convection. The low heat transfer coefficient between heated surface and air impedes the heat transfer to the flowing air, thereby, adversely affecting thermal performance of the system.Application of artificial roughness on underside of absorber surface has been found to be effective technique to improve thermo hydraulic performance of solar air heaters.
