Thermal performance of a shallow solar-pond water heater with semitransparent, multilayer surface insulation

The transient collection and storage performance have been examined for a shallow solar-pond water heater (solar tank) with a semitransparent, multilayer surfaceinsulation system. Both experimental and theoretical studies have been carried out for different numbers (zero to three) of surface-insulation layers. The results show that solar tanks with one or two surface-insulation layers yield higher water temperatures than a solar tank without surface-insulation layers. Furthermore, as the number of surfaceinsulation layers is decreased, the hot-water temperatures within the solar tank decrease rapidly after reaching a maximum.