System performance of built-in-storage type solar water heater with transparent insulation

Abstract

A built-in-storage type solar water heater, with transparent insulation (honeycomb hexagonal PS) on top, is theoretically investigated. Its thermal performance in a fixed surface orientation is compared with those of identical systems in identical orientation with (i) no insulation on top, (ii) moveable insulation during off-sunshine hours and (iii) transparent insulation on top and moveable insulation during off-sunshine hours. The effect of tracking the sun by the system is also studied. Calculations are carried out for studying long-term system performance for 10 days. Forward time step matching technique is used for solving the system equations. It seen that though the transparent insulation reduces the rise in water temperature during the day time, it enhances the storage potential of the system.