“…Flat plate collectors are either corrugated (Mathur et al, 1959), bond duct (Patil, 1975) or tube-in-plate type (CSIRO, 1964) with different clamping arrangements (Yellot and Sobotka, 1964;Gupta and Garg, 1968;Bliss, 1959). The performance of the flat plate collector depends upon various design parameters, such as the number of covers, type and thickness of glazing (Whillier, 1963), antireflecting coating on cover glass (Hsieh and Coldeway, 1974), heat mirror coating on the inner glass (Winegarner, 1976), the type of coating on the collector plate (Nahar and Garg, 1981), spacing between the collector and the inner glass (Nahar and Garg, 1980), an evacuated space between the collector and the inner glass (Simon, 1975), the arresting of convective movement between the collector plate and the inner glass by using transparent insulation material (TIM) (Hollands, 1965;Nahar et al, 1995), and the type of insulation used (Whillier and Saluja, 1965), etc. all of which are responsible for the performance of a flat plate collector.…”