In this paper, a study to describe irreversibility in a water heating solar flat plate collector is conducted. The collector is visualized as a heat exchanger, and the study concentrates on minimizing the internal contributions of irreversibility. The analysis is supported by data obtained from ASHRAE based experiments on a solar flat plate collector. The objective of this work is to demonstrate the thermodynamic trade-off in the design and operational parameters in a solar flat plate collector of a specific design application.